US007874940B2

(12) Ulllted States Patent (10) Patent N0.: US 7,874,940 B2 Kim et al. (45) Date of Patent: Jan. 25, 2011

(54) EXTRUSION METHOD FOR MAKING GOLF 4,726,590 A 2/ 1988 Molitor BALLS 4,728,693 A 3/1988 Droscher et a1. 4 755 552 A 7/1988 Jadamus et a1. (75) Inventors: Hyun Kim, Carlsbad, CA (US); Dean A. , , Snell, San Marcos, CA (US); Sanjay 4’792’l41 A 12/1988 L101? Kuttappas Oceanside’ A SulllVilIl 4,840,993 A 6/1989 BaItZ (73) Assignee: Taylor Made Golf Company, Inc., 4,844,471 A 7/1989 Terence et a1. Car1Sbad,CA (Us) 4,852,884 A 8/1989 Sullivan

( * ) Notice:. Subject. to any disclaimer,. . the term of this. 4,955,966 A 9/1990/ Yu k'l patent is extended or adjusted under 35 5’334’673 A 8 1994 Wu IJ'S'C~ 154(1)) by 754 days' 5,385,776 A 1/1995 Max?eld et 211. 5,436,295 A 7/1995 Nishikawa et a1. (21) Appl. No.: 11/486,938 5,460,367 A 10/1995 Horiuchi _ 5,948,862 A 9/1999 Sano et a1. (22) Flled: Jul- 13’ 2006 5,959,059 A 9/1999 Vedula et a1. (65) Prior Publication Data 6’012’991 A V2000 Klm et 31' 6,100,321 A 8/2000 Chen Us 2007/0015605 A1 Jan- 18> 2007 6,180,722 B1 1/2001 Dalton et a1. Related US. Application Data (60) Provisional application No. 60/699,303, ?led on Jul. 13, 2005 (Continued) (51) Int Cl OTHER PUBLICATIONS A633 3 7/06 (2006-01) US. Appl. N0. 10/926,509, ?led Aug. 25, 2004, Kim et a1. (52) US. Cl...... 473/377 (58) Field of Classi?cation Search ...... 473/377, (Con?rmed) S 1, _ ?l f 1 h h, 473/351 Primary ExamineriRaeann TrimieW ee app lcanon e or Comp ete Seam lstory' (74) Attorney, Agent, or FirmiKlarquist Sparkman, LLP (56) References Cited (57) ABSTRACT U.S. PATENT DOCUMENTS

4,115,475 A 9/1978 F tal. _ _ _ 4 123 061 A 10/ 1978 Diligiber The present invention relates to a method for making golf 4,153,772 A 5/1979 Schwesig et 31 balls by an extrusion molding process, particularly forming 4,183,876 A V1980 Comn et a1 ' golf ball cores from an extrusion moldable composition. The 4,195,015 A 3/1980 D 61 e ens et ‘a1 present invention also relates to a golf ball having an extruded 4,230,838 A l 0 / 1980 Foy et a1 ' core, an outer cover layer and, optionally, one or more inner 4,331,786 A 5/1982 Foy et 31. Cover layers 4,332,920 A 6/1982 Foy et 31. 4,546,980 A 10/1985 Gendreau et a1. 17 Claims, 2 Drawing Sheets US 7,874,940 B2 Page 2

U.S. PATENT DOCUMENTS 2002/0040111 A1 4/2002 Rajagopalan 2003/0119989 A1 6/2003 Ladd et al. 6,329,458 12/2001 Takesue et a1. 2003/0158312 A1 8/2003 Chen 6,426,387 7/2002 Kim 2003/0224871 A1 12/2003 Kim et a1. 6,485,378 11/2002 Boehm 2004/0044136 A1* 3/2004 Kim ...... 525/192 6,508,724 1/2003 Dalton 2004/0092336 A1 5/2004 Kim et a1. 6,562,906 5/2003 Chen 2005/0059756 A1 3/2005 Kim et a1. 6,569,037 5/2003 IchikaWa et al. 2005/0148725 A1* 7/2005 StatZ et al...... 524/523 6,616,552 9/2003 Takesue et a1. 6,692,379 2/2004 Morgan et al. OTHER PUBLICATIONS 6,762,244 7/2004 Rajagopalan et al. 6,770,360 8/2004 Mientus et al. U.S. Appl. No. 10/662,619, ?led Dec. 9, 2004, Kim et al. 6,776,942 8/2004 Kim US. Appl. No. 11/182,170, ?led Jul. 14, 2005, Kim. 6,794,447 9/2004 Kim et al. http://WWWchemsoc.org/chembytes/eZine/2002/birkett4uly02. 6,812,276 11/2004 Yeager htm (accessed on Nov. 1, 2006). 6,835,146 12/2004 Jordan et al. http://bppetrochemicalscom (accessed on Nov. 1, 2006) (http://bp. 6,861,474 3/2005 Kim com/modularhome.do?categoryId:6110). 6,878,075 4/2005 Kim http://WWW.nml.csir.co.Za/neWs/20020711/indeX1.htm (accessed on 6,905,423 6/2005 Morgan et al. May 29, 2007). 6,930,150 8/2005 Kim Research disclosure 29703, published in Jan. 1989. 6,960,629 11/2005 Voorheis et al. 7,041,769 5/2006 Wu et al. * cited by examiner

US 7,874,940 B2 1 2 EXTRUSION METHOD FOR MAKING GOLF Rajagopalan et al., US. Pat. No. 6,762,244 describes golfball BALLS cores comprising thermoplastic compositions. The ’244 patent states that the core compositions “may then be injec This application claims the bene?t of the earlier ?ling date tion or compression molded during Which time it is typically of US. Provisional Application No. 60/699,303, ?led on Jul. also heated to an activation temperature suf?cient to facilitate 13, 2005. The entire disclosure of provisional application No. crosslinking (emphasis added).” 60/699,303 is considered to be part of the disclosure of the Compression molding is perhaps the most common accompanying application and is incorporated herein by ref method used to prepare and crosslink polybutadiene in golf erence. ball cores. To make golf ball cores comprising polybutadiene, all components of the core composition are combined to form FIELD a sticky composition that does not hold its shape and ?oWs over time at room temperature (cold ?oWs). This makes stor The present application concerns embodiments of a age of such compositions problematic and thus requires that method for making golf balls, particularly an extrusion the cores be made directly from these compositions. In addi method for making golf ball components, such as golf ball tion, these materials are inconvenient for injection molding cores, particularly ball cores comprising thermoplastic mate processes. Typically, the polybutadiene composition is ?rst rials, and golf balls made according to the method. extruded to form a slug. The slug is placed into a mold and subjected to a compression molding cycle comprising apply BACKGROUND ing heat and pres sure to crosslink the polymeric material. The 20 core composition, and the temperature, pressure and duration A. Golf Ball Construction and Composition of the molding cycle, all can be independently varied to control the resulting core properties. Modern golf balls generally are either one-piece or mul Injection molding often is used to form cover layers over a tiple-piece constructions. One-piece balls, molded from a core. The ’942 patent alludes to this process stating that: homogeneous mass of material With a dimple pattern, are 25 a core is placed inside a set of mold sections, and the mold inexpensive and very durable, but do not provide great dis sections are closed to form a spherical cavity around the tance because of relatively high spin and loW velocity. TWo core. A molten polymeric material is injected into the piece balls are made by injection or compression molding a mold cavity under pressure through the gates. This poly cover around a solid, often single-piece, spherical rubber meric material can be thermoplastic or chemically reac core. Hard ionomer thermoplastic resins are common mate 30 tive; that is, the material can begin to react during or after rials used to form cover layers about the core. TWo-piece balls molding and form crosslinks to harden (emphasis have high initial speeds but relatively loW spin rates, and added). hence perform Well for drives and other shots made using Woods, but do not perform as Well for shots made With short Relative to compression molding, injection molding has rapid cycle times, potentially cheaper operating costs, and the capa irons Where distance is less important and high spin rate is 35 desirable. bility of producing thinner layers about the core With closely Ball performance can be further modi?ed, particularly the controlled thickness variations, Which is important for multi travel distance and the feel transmitted to the golfer through layered balls having tWo or more intermediate layers betWeen the club, by the addition of layers betWeen the core and outer the core and cover. Mixing thermoset rubber materials using an extruder also cover layer. A three-piece ball has one additional layer 40 betWeen the core and outer cover layer. Similarly, a four-piece is knoWn. Dalton, US. Pat. No. 6,508,724 states that: ball results if tWo additional layers are introduced betWeen the Preferably, the blends are formed by ?rst combining the thermoset rubber materials With the compatible, non core and outer cover layer, and so on. Golf ball core composition, and in particular polymer hard ionic, modi?ed polyole?ns of this invention in, for example, a tWin screW extruder, to produce an initial ness, compression and resilience, is a signi?cant factor that 45 determines performance. Most golf ball core compositions polymer blend. Other components of the mixture needed are made from synthetic rubbers based on cis-l,4-polybuta for cross linking, as described beloW, are then added to diene, Which often is crosslinked using crosslinking agents, this ?rst mixture. The formation of the core and the formation and application of the covers for a tWo-piece such as sulfur or peroxides, often in combination With co ball may then be performed using methods and equip crosslinking agents such as Zinc diacrylate. Alternatively, 50 radiation may be employed as a crosslinking agent. The ment knoWn in the art (emphasis added). Weight and hardness of the core may be further adjusted using Similarly, Kim, US. Pat. No. 6,426,387 states, With reference ?ller materials. to polybutadiene rubber cores, that “[t]he rubbers used in the Golf balls are becoming increasingly complex as neW present invention can be processed using any conventional materials are developed that are useful for making balls. The 55 mixing method, such as a Bambury mixer, calendaring, extru golf ball business also is competitive, and as a result there is sion, or an internal mixer (emphasis added).” And, Kim, US. a great deal of literature concerning golf balls generally. For Pat. No. 6,878,075 states that “[t]he step of preparing a com example, in 2005 more than 8,000 issued United States pat position can comprise a step of dry-blending the composition, ents refer to golf balls in the speci?cation. or a step of mixing the composition using a mill, internal 60 mixer or extruder (emphasis added) .” Thus, as currently B. Methods for Making Golf Balls understood, knoWn methods mix rubber-based core materi als, and extrude the mixture through a die to form a golf core Golf balls typically are made by compression or injection preform, but thermoplastic-based core materials have not molding. This is particularly true for golf ball cores. For been extruded to form a golf ball core or core preform. example, Kim et al., US. Pat. No. 6,776,942 states that “cores 65 Compression molding and injection molding are not can be made using either compression molding or injection entirely satisfactory processes for making modern golf balls, molding processes (emphasis added).” As another example, particularly as additional polymeric compositions are devel US 7,874,940 B2 3 4 oped that are useful for making golf balls having varying resins. The disclosed embodiments address problems associ performance attributes. For example, compression molding ated With prior processes, such as operating costs, process techniques are convenient for making golf ball cores With a e?iciencies, limitations on the materials that can be used to conventional rubber-based core composition. In general, a form ball parts, the presence of microvoids, and/ or other conventional rubber-based core composition is prepared by a deleterious disadvantages. batch compounding process using a Bambury mixer and a One embodiment of the method for forming a golf ball core tWo-roll mill. Since it is a batch process, the batch siZe is or core preform comprises extruding at least one thermoplas limited by the machine capacity and it is dif?cult to avoid any tic, extrusion-processable polymeric material orpolymer pre variance from batch-to -batch. cursor material through a die. The process can be performed Most thermoplastics are supplied as pellets or poWders. as a batch process, but preferably is performed as a substan These forms can be used to make golf ball cores using either tially continuous process. The golf ball generally includes at compression molding techniques or injection molding tech least one additional layer about the core, such as an outer niques. But it is extremely dif?cult to control the compression cover layer, and optionally at least one intermediate layer molding process using pellets or poWders. For example, it disposed betWeen the core and the outer cover layer. Layers may be dif?cult to feed accurate amounts of the material into other than the core can be produced by compression molding, cavities, avoid spilling material outside the cavity, and hold injection molding, reaction injection molding, coating, cast the material in place until the mold is closed. It also is dif?cult ing, dipping, or combinations thereof. Thus, the method typi to control the compression molding process to make a golf cally comprises forming a composition comprising a compo ball core Without forming any voids inside the core, especially sition useful for forming a golf ball core, such as at least one When pellets or poWders are used. Adding any additional 20 thermoplastic polymer or a polymer precursor material, ingredients to the core composition, such as ?llers, modi?ers, extruding a golf ball core comprising the composition and curatives during, also is dif?cult during the compression through a die, optionally forming at least one intermediate molding process. layer comprising a polymeric material about the core by It is possible to compound a core composition having all compression molding or injection molding, and forming an the ingredients and to make pellets With the compound foruse 25 outer cover layer comprising a polymeric material about the in injection molding processes. But injection molding core and any intermediate layer(s) by compression molding, requires using complicated and expensive molds and associ injection molding, reaction injection molding, coating, cast ated structures that provide a signi?cant barrier to process ing, dipping, or combinations thereof. output and production e?iciency. For example, an injection One bene?t of extruding polymer cores or core preforms molding cycle comprises feeding material to the barrel; melt 30 according to one described embodiment is the ability to com ing the material to form a melt; transferring the melt by pound core compositions at one time to include all materials rotating the screW and applying heat to the barrel; injecting desired in the core including, by Way of example and Without the molten material to the mold cavities through a noZZle, limitation, base resins, cross-linking agents, co-cross-linking sprue, runner, and gate(s); solidifying the material (usually by agents, peptiZers, accelerators, UV stabiliZers, photostabiliZ a cooling cycle); and opening the mold to obtain the ?nished 35 ers, photoinitiators, co-initiators, antioxidants, colorants, dis part(s). Output capacity is determined by the number of cavi persants, mold release agents, processing aids, ?llers, density ties and the cycle time required to complete each injection adjusting ?llers, nano-?llers, ?bers, other materials noW molding cycle. knoWn or hereafter developed useful for making golf balls, Conventional injection molding process commonly used and combinations thereof. Another bene?t associated With for making golf balls may introduce imperfections in the 40 certain disclosed embodiments for extruding polymer cores molded golf ball. For example, Weld lines may form When or core preforms comprises forming a ?rst polymeric com molten molding materials do not fuse completely. For inj ec position and subsequently modifying the composition. For tion molding, lines can form at gate contact points. Weld lines example, the method may further comprise crosslinking an and lines formed by gates produce Weak portions in the golf extruded core or core preform, such as during a subsequent ball, Which decrease their durability and alter ball perfor 45 compression molding step or by irradiation. Moreover, for mance. extruded thermoplastics, cores or core preforms can be Moreover, cores made by current injection molding pro stored, and then softened, for example, for other modi?ca cesses often include microvoids, typically caused by tions, such as making cores having different dimensions or entrapped gases that are not removed during the production densities, or further modifying the core or core perform com process. Microvoids have deleterious effects both on the 50 positions chemically, mechanically, radiationally, thermally, durability and performance of the golf ball. or combinations thereof. As another example, core preforms The present invention provides a method for making golf can be made that are particularly siZed and shaped for subse balls, particularly golf ball cores, that address de?ciencies quent processing by conventional methods, such as compres encountered for compression molding and injection molding sion molding, and optionally stored prior to such subsequent processes. 55 processing. As stated in the Background, knoWn methods for making SUMMARY cores often produce microvoids. Another bene?t of the pres ently disclosed embodiments is that extrusion processing can Based on the Background, a need exists for a core-making further comprise substantially degassing the polymeric mate process that combines the bene?ts of an extrusion process, 60 rial or polymer precursor material. Degassing can be typically used to compound a material for injection molding, achieved, for example, by subjecting the polymeric material and the compression molding process typically used to make or polymer precursor material to a vacuum, thereby produc a thermoset rubber core. The present invention provides a ing a core substantially free of microvoids. method that satis?es that need. Disclosed embodiments con A person of ordinary skill in the art Will appreciate that the cern a process for extruding materials, noW knoWn or hereaf 65 present extrusion method can be used With any golf ball ter developed, that are useful for making golf ball cores, composition amenable to extrusion processing. For example, particularly a core composition comprising thermoplastic and Without limitation, the polymeric material may be poly US 7,874,940 B2 5 6 alkenamers, crosslinked polyalkenamers, synthetic rubbers, prising a center portion, an intermediate layer comprising an natural rubbers, thermoplastic polymers, or combinations injection or compression moldable composition, and an outer thereof. Speci?c examples of classes of thermoplastic mate cover layer comprising an injection or compression moldable rials include, again Without limitation, ole?nic thermoplastic composition. The aforementioned injection or compression elastomers, metallocene catalyzed polymers, rubber-based moldable composition including polymeric materials thermoplastics, co-polyester thermoplastic elastomers, block selected from thermoset polyurethanes, thermoplastic poly copolymers comprising an aromatic vinyl group as a ?rst urethanes, metallocene catalyZed polymers, unimodal iono block and a second block comprising a conjugated diene, mers, bimodal ionomers, modi?ed unimodal ionomers, polyamides, copolyamides, styrene block copolymers, func modi?ed bimodal ionomers, thermoplastic elastomers, poly tionaliZed styrenic block copolymers, polyesters, polyure ole?ns, polyalkenamers, polyesters, polyetheresters, poly thanes, ionomers, and combinations thereof. The polymeric carbonates, polyamides, polyetheramides, and any and all material used to form the core, any intermediate layer, and/or combinations thereof. an outer cover layer also can include any material noW knoWn Similarly, an embodiment of a four-piece golf ball com or hereafter developed that is useful for making golf balls, prises an extruded polymeric core, particularly an extruded including Without limitation, cross-linking agents, co-cross thermoplastic core, often comprising a center portion, an linking agents, peptiZers, accelerators, UV stabiliZers, pho inner intermediate layer comprising an injection or compres tostabiliZers, photoinitiators, co-initiators, antioxidants, sion moldable composition, such as a polymer selected from colorants, dispersants, mold release agents, processing aids, unimodal ionomers, bimodal ionomers, modi?ed unimodal ?llers, density adjusting ?llers, nano-?llers, ?bers, nano-? ionomers, modi?ed bimodal ionomers, thermoset polyure bers, other materials noW knoWn or hereafter developed use 20 thanes, thermoplastic polyurethanes, metallocene catalyZed ful for making golf balls, and combinations thereof. polymers, thermoplastic elastomers, polyole?ns, polyalk A person of ordinary skill in the art also Will appreciate that enamers, polyesters, polyetheresters, polycarbonates, polya extruding can be performed using any suitable extruder, mides, polyetheramides, and any and all combinations including but not limited to, a ram extruder, a continuous-?ow thereof, an outer intermediate layer comprising an injection ram extruder, a gear-pump extruder, a single screW extruder, 25 or compression moldable composition, and an outer cover a tWin screW extruder, or a multiple-screW extruder. More layer comprising an injection or compression moldable com over, the process can be practiced using plural extruders as a position, such as a polymer selected from the group consist system in a continuous or batch production process. ing of unimodal ionomers, bimodal ionomers, modi?ed uni Embodiments of golf balls made by the method also are modal ionomers, modi?ed bimodal ionomers, thermoset described. One disclosed embodiment comprises an extruded 30 polyurethanes, thermoplastic polyurethanes, metallocene polymeric material or polymer precursor material, such as a catalyZed polymers, thermoplastic elastomers, polyole?ns, thermoplastic core material, preferably substantially free of polyalkenamers, polyesters, polyetheresters, polycarbonates, microvoids, optionally at least one intermediate layer and an polyanides, polyetheramides, and any and all combinations outer cover layer comprising a polymeric material. The thereof. Disclosed golf ball embodiments may have a core extruded core material, the polymeric material of any inter 35 comprising one or more core layers disposed about a core mediate layer(s) and/or the outer cover layer may further center. For such embodiments, the difference betWeen a hard comprise cross-linking agents, co-cross-linking agents, pep ness of one core layer and the next adjacent core layer is tiZers, accelerators, UV stabiliZers, photostabiliZers, photo greater than 2, preferably greater than 5, most preferably initiators, co-initiators, antioxidants, colorants, dispersants, greater than 10 units of Shore D. Moreover, the hardness of mold release agents, processing aids, ?llers, density adjusting 40 the core may increase or decrease outWards from the center ?llers, nano-?llers, ?bers, nano-?bers, other materials noW portion to an outer core layer. knoWn or hereafter developed useful for making golf balls, The foregoing and other objects, features, and advantages and combinations thereof. Cover layers may have any suit of the invention Will become more apparent from the folloW able composition, including Without limitation, a reaction ing detailed description, Which proceeds With reference to the product of (a) diol(s), polyol(s), or combinations thereof; (b) 45 accompanying ?gures. diisocyanate(s), polisocyanate(s), or combinations thereof, (c) diamine(s), polyamine(s), or combinations thereof, or any BRIEF DESCRIPTION OF THE DRAWINGS combinations of (a), (b), and (c). Moreover, a cover layer may include a composition formed by a method comprising: (1) FIG. 1 is a schematic cross section of a tWo-piece golf ball. mixing at least one componentA that is a monomer, oligomer, 50 FIG. 2 is a schematic cross section of a three-piece golf prepolymer, or polymer comprising at least 5% by Weight of ball. anionic functional groups; at least one component B that is a monomer, oligomer, prepolymer, or polymer comprising less DETAILED DESCRIPTION by Weight of anionic functional groups than the Weight per centage of anionic functional groups of the at least one com 55 I. Introduction and De?nitions ponentA; and at least one component C that is a metal cation, thereby forming a ?rst composition; and (2) melt-processing The folloWing de?nitions are provided to aid the reader, the ?rst composition to produce a reaction product of the and are not intended to de?ne terms to have a scope that Would anionic functional groups of the at least one componentA and be narroWer than Would be understood by a person of ordinary the at least one component C to form the polymer blend 60 skill in the art of golf ball composition and manufacture. composition, Wherein the polymer blend composition incor Any numerical values recited herein include all values porates an in-situ-formed pseudo-crosslinked netWork of the from the loWer value to the upper value. All possible combi at least one component A in the presence of the at least one nations of numerical values betWeen the loWest value and the component B. highest value enumerated herein are expressly included in A disclosed embodiment of a three-piece golf ball com 65 this application. prises a core comprising an extruded polymeric material, As used herein, the term “core” is intended to mean the particularly a thermoplastic polymeric material, often com elastic center of a golf ball, Which may have a unitary con US 7,874,940 B2 7 8 struction. Alternatively the core itself may have a layered into the molecular weight distribution curve for the total construction having a spherical “center” and additional “core resulting polymer product, that curve will show two maxima layers,” with such layers being made of the same material or or at least be distinctly broadened in comparison with the a different material from the core center. curves for the individual fractions. Such a polymer product is The term “cover” is meant to include any layer of a golf called bimodal. It is to be noted here that also the chemical ball, which surrounds the core. Thus a golf ball cover may compositions of the two fractions may be different. include both the outermost layer and also any intermediate Similarly the term “unimodal polymer” refers to a polymer layers, which are disposed between the golf ball center and comprising one main fraction and more speci?cally to the outer cover layer. “Cover” may be used interchangeably with form of the polymers molecular weight distribution curve, the term “cover layer”. i.e., the molecular weight distribution curve for the total poly The term “intermediate layer” may be used interchange mer product shows only a single maximum. ably with “mantle layer,” “inner cover layer” or “inner cover” The term “polyalkenamer” is used interchangeably herein and is intended to mean any layer(s) in a golf ball disposed with the term “polyalkenamer rubber” and means a polymer between the core and the outer cover layer. of one or more alkenes, including cycloalkenes, having from The term “fully-interpenetrating network” refers to a net 5-20, preferably 5-15, most preferably 5-12 ring carbon work that includes two independent polymer components that atoms. The polyalkenamers may be prepared by any suitable penetrate each other, but are not covalently bonded to each method including ring opening metathesis polymerization of other. one or more cycloalkenes in the presence of organometallic The term “semi-interpenetrating network” refers to a net catalysts as described in US. Pat. Nos. 3,492,245, and 3,804, work that includes at least one polymer component that is 20 803, the entire contents of both of which are incorporated linear or branched and interspersed in the network structure of herein by reference. at least one of the other polymer components. A “thermoplastic material” is generally de?ned as a mate The term “pseudo-crosslinked networ ” refers to materials rial that is capable of softening or fusing when heated and of that have crosslinking, but, unlike chemically vulcanized hardening again when cooled. Thermoplastic polymer chains elastomers, pseudo-crosslinked networks are formed in-situ, 25 often are not cross-linked, but the term “thermoplastic” as not by covalent bonds, but instead by ionic clustering of the used herein may refer to materials that initially act as ther reacted functional groups, which clustering may disassociate moplastics, such as during an initial extrusion process, but at elevated temperatures. which also may be crosslinked, such as during a compression In the case of a ball with two intermediate layers, the term molding step to form a ?nal structure. “inner intermediate layer” may be used interchangeably 30 A “?ber” is a general term and the de?nition provided by herein with the terms “inner mantle” or “inner mantle layer” Engineered Materials Handbook, Vol. 2, “Engineering Plas and is intended to mean the intermediate layer of the ball tics”, published by A.S.M. lntemational, Metals Park, Ohio, which is disposed nearest to the core. USA, is relied upon to refer to ?lamentary materials with a Again, in the case of a ball with two intermediate layers, the ?nite length that is at least 100 times its diameter, which is term “outer intermediate layer” may be used interchangeably 35 typically 0.10 to 0.13 mm (0.004 to 0.005 in.). Fibers can be herein with the terms “outer mantle” or “outer mantle layer” continuous or speci?c short lengths (discontinuous), nor and is intended to mean the intermediate layer of the ball mally no less than 3.2 mm (V8 in.). Although ?bers according which is disposed nearest to the outer cover layer. to this de?nition are preferred, ?ber segments, i.e., parts of The term “outer cover layer” is intended to mean the out ?bers having lengths less than the aforementioned are also ermost cover layer of the golf ball on which, for example, the 40 considered to be encompassed by the invention. Thus, the dimple pattern, paint and any writing, symbol, etc. is placed. terms “?bers” and “?ber segments” are used herein. “Fibers If, in addition to the core, a golf ball comprises two or more or ?ber segments” and “?ber elements” are used to encom cover layers, only the outermost layer is designated the outer pass both ?bers and ?ber segments. Embodiments of the golf cover layer. The remaining layers may be designated inter ball components described herein may include ?bers, includ mediate layers. The term outer cover layer is interchangeable 45 ing without limitation, glass ?bers, such as E ?bers, Cem-Fil with the term “outer cover”. ?lament ?bers, and 204 ?lament strand ?bers, carbon ?bers, The term “preform” typically refers to an extruded core such as graphite ?bers, high modulus carbon ?bers, and high that undergoes subsequent mechanical, thermal or chemical strength carbon ?bers, asbestos ?bers, such as chrysotile and processing to form a ?nal core, such as, by way of example crocidolite, cellulose ?bers; aramid ?bers, such as Kevlar, and not limitation, physical changes in the shape or the 50 including types PRD 29 and PRD 49, and metallic ?bers, such dimension of the perform, crosslinking or composition modi as copper, high tensile steel, and stainless steel. In addition, ?cation by the addition of materials to the preform during an single crystal ?bers, potassium titanate ?bers, calcium sul initial extrusion or subsequent to an initial extrusion step, and phate ?bers, and ?bers or ?laments of one or more linear combinations thereof. synthetic polymers such as Terylene, Dacron, Perlon, Orion, “Polymer precursor material” refers to any material that 55 Nylon, including Nylon type 242, are contemplated. Polypro can be further processed to form a ?nal polymer material of a pylene ?bers, including mono?lament and ?brillated ?bers manufactured golf ball, such as, by way of example and not are also contemplated. Fibers used in golf ball components limitation, monomers that can be polymerized during extru are described more fully in Kim et al. US. Pat. No. 6,012,991, sion in a manner that does not preclude continued use of the which in incorporated herein by reference. extruder, or a material that can undergo additional processing, 60 A “nanocomposite” is de?ned as a polymer matrix having such as crosslinking, subsequent to an initial extrusion step. nano?ller within the matrix. Nanocomposite materials and The term “bimodal polymer” refers to a polymer compris golf balls made comprising nanocomposite materials are dis ing two main fractions and more speci?cally to the form of the closed in Kim et al., US. Pat. No. 6,794,447, and US. Pat. polymer’s molecular weight distribution curve, i.e., the No. 5,962,553 to Ellsworth, US. Pat. No. 5,385,776 to appearance of the graph of the polymer weight fraction as 65 Max?eld et al., and US. Pat. No. 4,894,411 to Okada et al., function of its molecular weight. When the molecular weight which are incorporated herein by reference in their entirety. distribution curves from these fractions are superimposed Inorganic nano?ller materials generally are made from clay, US 7,874,940 B2 10 and may be coated by a suitable compatibiliZing agent, as outer cover layer 26 and arranged in various desired patterns. discussed beloW in further detail. The compatibiliZing agent Although FIGS. 1 and 2 illustrate only tWo- and three-piece alloWs for superior linkage betWeen inorganic and organic golf ball constructions, golf balls With additional layers also material, and it also can account for the hydrophilic nature of are included Within the claimed embodiments. the inorganic nano?ller material and the possibly hydropho 5 The present invention can be used to form golf balls of any bic nature of the polymer. Nano?ller particles typically, but desired siZe. “The Rules of Golf’ by the USGA dictate that not necessarily, are approximately 1 nanometer (nm) thick the siZe of a competition golf ball must be at least 1.680 inches and from about 100 to about 1000 nm across, and hence have extremely high surface area, resulting in high reinforcement in diameter; hoWever, golf balls of any siZe can be used for ef?ciency to the material at loW loading levels of the particles. leisure golf play. The preferred diameter of the golf balls is The sub-micron-siZed particles enhance material properties, from about 1.680 inches to about 1.800 inches. Oversize golf such as the stiffness of the material, Without increasing its balls With diameters above about 1.760 inches to as big as Weight or opacity and Without reducing the material’s loW 2.75 inches are also Within the scope of the invention. temperature toughness. Materials incorporating nano?ller A. Core materials can provide these property improvements at much loWer densities than those incorporating conventional ?llers. The core of the balls of the present invention have a diam eter of from about 0.5 to about 1.62 inches, preferably from Nano?llers can disperse Within a polymer matrix in three Ways. The nano?ller may stay undispersed Within the poly about 0.7 to about 1.60 inches, more preferably from about 1 to about 1.58 inches, yet more preferably from about 1.20 to mer matrix. Undispersed nano?llers maintain platelet aggre about 1.54 inches, and most preferably from about 1.40 to gates Within the polymer matrix and have limited interaction 20 With the polymer matrix. As the nano?ller disperses into the about 1.52 inches. polymer matrix, the polymer chains penetrate into and sepa The golf ball cores of the present invention also typically rate the platelets. When vieWed by transmission electron have a PGA compression of from about 30 to about 190, microscopy or x-ray diffraction, the platelet aggregates are preferably from about 40 to about 160, typically from about expanded relative to undispersed nano?ller. Nano?llers at 25 50 to about 130, and most preferably from about 60-100. this dispersion level are referred to as being intercalated. A The Shore D hardness of the core center and core layers fully dispersed nano?ller is said to be exfoliated. An exfoli made according to the present invention may vary from about ated nano?ller has the platelets fully dispersed throughout the 20 to about 90, typically from about 30 to about 80, and even polymer matrix; the platelets may be dispersed unevenly but more typically from about 40 to about 70. preferably are dispersed substantially evenly. 30 In one embodiment of the present invention the core may Nanocomposite materials are materials incorporating from comprise an extrusion-processable polymeric material, such about 0.1% to about 20%, preferably from about 0.1% to as an extrusion-processable thermoplastic material, and about 15%, and most preferably from about 0.1% to about optionally, one or more additional layers disposed around the 10% nano?ller potentially reacted into and preferably sub center as illustrated in FIG. 2. These additional layers may be stantially evenly dispersed through intercalation or exfolia 35 made from the same composition as used in the center por tion into the structure of an organic material, such as a poly tion, or may be a different material. mer, to provide strength, temperature resistance, and other property improvements to the resulting composite. Descrip B. Intermediate Layer(s) and Cover Layer tions of particular nanocomposite materials and their manu FIG. 2 illustrates an exemplary embodiment of a golf ball facture can be found in Us. Pat. No. 5,962,553 to Ellsworth, 40 20 comprising a core 22, formed in the shape of the sphere, an U.S. Pat. No. 5,385,776 to Max?eld et al., and Us. Pat. No. intermediate layer 24, disposed on the spherical core and an 4,894,411 to Okada et al. Examples of nanocomposite mate outer cover layer 26. The golf ball of the present invention rials currently marketed include M1030D, manufactured by may comprise from 0 to at least 5 intermediate layer(s), Unitika Limited, of Osaka, Japan, and 101 5C2, manufactured preferably from 0 to 3 intermediate layer(s), more preferably by UBE America of NeW York, N.Y. 45 from 1 to 3 intermediate layer(s), and most preferably 1 to 2 When nanocomposites are blended With other polymer intermediate layer(s). systems, the nanocomposite may be considered a type of In one preferred embodiment, the golf ball of the present nano?ller concentrate. HoWever, a nano?ller concentrate invention is a three-piece ball having a core made using an may be more generally a polymer into Which nano?ller is extrusion-processable polymeric material. mixed; a nano?ller concentrate does not require that the nano 50 In another preferred embodiment of the present invention, ?ller has reacted and/or dispersed evenly into the carrier the golf ball of the present invention is a four-piece ball made polymer. When used in the manufacture of golf balls, nano using an extrusion-processable core composition. composite materials can be blended effectively into ball com positions at a typical Weight percentage, Without limitation, The one or more intermediate layers of the golf balls of the present invention has a thickness of from about 0.01 to about of from about 1% to about 50% of the total composition used 55 to make a golf ball component, such as a cover or core, by 0.20 inch, preferably from about 0.02 to about 0.15 inch, Weight. more preferably from about 0.03 to about 0.10 inch and most preferably from about 0.03 to about 0.06 inch. II. Golf Ball Composition and Construction The one or more intermediate layers of the golf balls of the 60 present invention also has a Shore D hardness greater than FIG. 1 illustrates a tWo-piece golf ball 10 comprising a about 25, preferably greater than about 30, and typically solid center or core 12, and an outer cover layer 14. Golf balls greater than about 40. also typically include plural dimples 16 formed in the outer The one or more intermediate layers of the golf balls of the cover and arranged in various desired patterns. present invention also has a ?exural modulus from about 5 to FIG. 2 illustrates a 3-piece golf ball 20 comprising a core 65 about 500, preferably from about 15 to about 300, more 22, an intermediate layer 24 and an outer cover layer 26. Golf preferably from about 20 to about 200, and most preferably ball 20 also typically includes plural dimples 28 formed in the from about 25 to about 100 kpsi. US 7,874,940 B2 11 12 The cover layer of the balls of the present invention has a for such properties, typical in the ?eld, or that otherWise thickness of from about 0.01 to about 0.10, preferably from Would be knoWn to a person of ordinary skill in the ?eld. about 0.02 to about 0.08, more preferably from about 0.04 to about 0.06 inch. A. General Description of Polymeric Materials The cover layer of the balls of the present invention has a Polymeric materials generally considered useful for mak Shore D hardness of from about 30 to about 70, preferably ing golf balls according to the process of the present invention from about 30 to about 65, more preferably from about 45 to include, Without limitation, synthetic and natural rubbers, about 60. thermoset polymers such as thermoset polyurethanes and The COR of the golf balls of the present invention is greater thermoset polyureas, as Well as thermoplastic polymers than about 0.760, preferably greater than about 0.780, more including thermoplastic elastomers such as metallocene cata preferably greater than about 0.790, and most preferably lyZed polymer, unimodal ethylene/carboxylic acid copoly greater than about 0.800 at 125 ft/ sec inbound velocity. mers, unimodal ethylene/carboxylic acid/carboxylate ter polymers, bimodal ethylene/carboxylic acid copolymers, The COR of the golf balls of the present invention is greater bimodal ethylene/carboxylic acid/carboxylate terpolymers, than about 0.730, preferably greater than about 0.750, more unimodal ionomers, bimodal ionomers, modi?ed unimodal preferably greater than about 0.770, and most preferably ionomers, modi?ed bimodal ionomers, thermoplastic poly greater than about 0.790 at 143 ft/ sec inbound velocity. urethanes, thermoplastic polyureas, polyamides, copolya mides, polyesters, copolyesters, polycarbonates, polyole?ns, Ill. Polymeric Materials polyalkenamer, polyphenylene oxides, polyphenylene sul 20 ?des, diallyl phthalate polymers, polyimides, polyvinyl chlo Disclosed embodiments of the present invention particu rides, polyamide-ionomers, polyurethane-ionomers, polyvi larly concern a method for making a golf ball Whereby at least nyl alcohols, polyarylates, polyacrylates, polyphenylene the core of the ball is manufactured using at least one extru ethers, impact-modi?ed polyphenylene ethers, polystyrenes, sion processing step. Where a core is for'medusing at least one high impact polystyrenes, acrylonitrile-butadiene-styrene extrusion processing step, the process also may include form 25 copolymers, styrene-acrylonitriles (SAN), acrylonitrile-sty ing any intermediate layer(s) and outer cover layer for a rene-acrylonitriles, styrene-maleic anhydride (S/MA) poly desired golf ball by compression molding, injection molding, mers, styrenic copolymers, functionaliZed styrenic copoly reaction injection molding, coating, casting, dipping, or com mers, functionaliZed styrenic terpolymers, styrenic binations thereof. terpolymers, cellulosic polymers, liquid crystal polymers Any extrusion-processable material that is useful for form 30 (LCP), ethylene-propylene-diene terpolymers (EPDM), eth ing a golf ball core or core preform that is noW knoWn or ylene-vinyl acetate copolymers (EVA), ethylene-propylene hereafter developed can be used in the process of the pres copolymers, ethylene vinyl acetates, polyureas, and polysi ently disclosed embodiments to manufacture a golf ball. One loxanes and any and all combinations thereof. disclosed embodiment comprises extruding a core material, More speci?c examples of particular polymeric materials particularly a thermoplastic core material, or a thermoplastic useful for making golf ball cores, optional intermediate material that subsequently may be converted into a thermo set layer(s) and outer covers, again Without limitation, are pro material by subsequent processing, such as by applying vided beloW. elevated temperatures during a subsequent compression molding step. B. Polyalkenamers

The extrusion-processable core composition used to pre 40 Examples of suitable polyalkenamer rubbers are polypen pare the golf ball of the present invention material contains tenamer rubber, polyheptenamer rubber, polyoctenamer rub from about 1 to 100 Wt %, preferably from about 20 to 100 Wt ber, polydecenamer rubber and polydodecenamer rubber. For %, more preferably from about 45 to 100 Wt %, and even more further details concerning polyalkenamer rubber, see Rubber preferably from about 75 to 100 Wt % (based on the ?nal Chem. & Tech., Vol. 47, page 511-596, 1974, Which is incor Weight of the extrusion-processable composition) of one or 45 porated herein by reference. Polyoctenamer rubbers are com more polymers disclosed herein, typically a thermoplastic mercially available from Huls A G of Marl, Germany, and polymer. The polymers may be made by methods knoWn to a through its distributor in the U.S., Creanova Inc. of Somerset, person of ordinary skill in the art, or many may be obtained N.J ., and sold under the trademark VESTENAMEROR®. commercially. TWo grades of the VESTENAMER® trans-polyoctenamer The folloWing materials are provided solely as examples of 50 are commercially available: VESTENAMER 8012 desig materials useful for forming golf ball cores, intermediate nates a material having a trans-content of approximately 80% layers, and/ or cover layers. A person of ordinary skill in the art (and a cis-content of 20%) With a melting point of approxi Will recogniZe that the present invention is not limited solely mately 540 C.; and VESTENAMER 6213 designates a mate to those materials listed herein by Way of example. Moreover, rial having a trans -content of approximately 60% (cis-content a person of ordinary skill in the art also Will recogniZe that 55 of 40%) With a melting point of approximately 300 C. Both of various combinations of such materials can be used to form these polymers have a double bond at every eighth carbon the core, intermediate layer(s) and/ or outer cover layer. atom in the ring. Additional guidance for selecting materials useful for mak The polyalkenamer rubber preferably contains from about ing golf balls according to the disclosed embodiments is 50 to about 99, preferably from about 60 to about 99, more provided by considering those physical properties desirable 60 preferably from about 65 to about 99, even more preferably for making golf balls. For example, in addition to the exem from about 70 to about 90 percent of its double bonds in the plary list of materials provided herein, a person of ordinary trans -con?guration. The preferred form of the polyalkenamer skill in the art might consider, for example in selecting an for use in the practice of the invention has a trans content of extrudable core material, the compression, hardness, density, approximately 80%, hoWever, compounds having other ratios the ?exural modulus, elasticity, Coef?cient of Restitution 65 of the cis- and trans-isomeric forms of the polyalkenamer can (C.O.R), impact durability, tensile properties, acoustic behav also be obtained by blending available products for use in the ior, compatibility, processability, in vieW of the values stated invention. US 7,874,940 B2 13 14 The polyalkenamer rubber has a molecularWeight (as mea tion temperature of 1820 C. TWo or more cross-linking agents sured by GPC) from about 10,000 to about 300,000, prefer having different characteristic decomposition temperatures at ably from about 20,000 to about 250,000, more preferably the same tl/2 may be blended in the composition. For from about 30,000 to about 200,000, even more preferably example, Where at least one cross-linking agent has a ?rst from about 50,000 to about 150,000. characteristic decomposition temperature less than 1500 C., The polyalkenamer rubber has a degree of crystallization and at least one cross-linking agent has a second characteris (as measured by DSC secondary fusion) from about 5% to tic decomposition temperature greater than 1500 C., the com about 70%, preferably from about 6% to about 50%, more position Weight ratio of the at least one cross-linking agent preferably from about from 6.5% to about 50%, even more having the ?rst characteristic decomposition temperature to preferably from about from 7% to about 45%, the at least one cross-linking agent having the second char More preferably, the polyalkenamer rubber used in the acteristic decomposition temperature can range from 5:95 to present invention is a polymer prepared by polymerization of 95:5, or more preferably from 10:90 to 50:50. cyclooctene to form a trans-polyoctenamer rubber as a mix Besides the use of chemical cross-linking agents, exposure ture of linear and cyclic macromolecules. of the polyalkenamer rubber composition to radiation also Prior to its use in the golf balls of the present invention, the can serve as a cross-linking agent. Radiation can be applied to polyalkenamer rubber may be further formulated With one or the polyalkenamer rubber mixture by any knoWn method, more of the following blend components: including using microWave or gamma radiation, or an elec 1. Polyalkenamer Cross-Linking Agents tron beam device. Additives may also be used to improve Any crosslinking or curing system typically used for rub radiation-induced crosslinking of the polyalkenamer rubber. ber crosslinking may be used to crosslink the polyalkenamer 20 2. Co-Cross-Linking Agent rubber used in the present invention. Satisfactory crosslink The polyalkenamer rubber may also be blended With a ing systems are based on sulfur-, peroxide-, azide-, maleim co-cross-linking agent, Which may be a metal salt of an unsat ide- or resin-vulcanization agents, Which may be used in urated carboxylic acid. Examples of these include zinc and conjunction With a vulcanization accelerator. Examples of magnesium salts of unsaturated fatty acids having 3 to 8 satisfactory crosslinking system components are zinc oxide, 25 carbon atoms, such as acrylic acid, methacrylic acid, maleic sulfur, organic peroxide, azo compounds, magnesium oxide, acid, and fumaric acid, palmitic acid With the zinc salts of benzothiazole sulfenamide accelerator, benzothiazyl disul acrylic and methacrylic acid being most preferred. The unsat ?de, phenolic curing resin, m-phenylene bis-maleimide, thi urated carboxylic acid metal salt can be blended in the poly uram disul?de and dipentamethylene-thiuram hexasul?de. alkenamer rubber either as a preformed metal salt, or by More preferable cross-linking agents include peroxides, 30 introducing an 0t,[3-unsaturated carboxylic acid and a metal sulfur compounds, as Well as mixtures of these. Non-limiting oxide or hydroxide into the polyalkenamer rubber composi examples of suitable cross-linking agents include primary, tion, and allowing them to react to form the metal salt. The secondary, or tertiary aliphatic or aromatic organic peroxides. unsaturated carboxylic acid metal salt can be blended in any Peroxides containing more than one peroxy group can be desired amount, but preferably in amounts of about 10 parts to used, such as 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane 35 about 100 parts by Weight of the unsaturated carboxylic acid and 1 ,4-di-(2-tert-butyl peroxyisopropyl)benzene. Both sym per 100 parts by Weight of the polyalkenamer rubber. metrical and asymmetrical peroxides can be used, for 3. Peptizer example, tert-butyl perbenzoate and tert-butyl cumyl perox The polyalkenamer rubber compositions used in the ide. Peroxides incorporating carboxyl groups also are suit present invention also may incorporate one or more of the able. The decomposition of peroxides used as cross-linking 40 so-called “peptizers”. agents in the present invention can be brought about by apply The peptizer preferably comprises an organic sulfur com ing thermal energy, shear, irradiation, reaction With other pound and/or its metal or non-metal salt. Examples of such chemicals, or any combination of these. Both homolytically organic sulfur compounds include, Without limitation, and heterolytically decomposed peroxide can be used in the thiophenols, such as pentachlorothiophenol, 4-butyl-o-thio present invention. Non-limiting examples of suitable perox 45 cresol, 4 t-butyl-p-thiocresol, and 2-benzamidothiophenol; ides include: diacetyl peroxide; di-tert-butyl peroxide; diben thiocarboxylic acids, such as thiobenzoic acid; 4,4'dithio zoyl peroxide; dicumyl peroxide; 2,5-dimethyl-2,5-di(ben dimorpholine; and, sul?des, such as dixylyl disul?de, diben zoylperoxy)hexane; 1 ,4-bis-(t-butylperoxyisopropyl) zoyl disul?de; dibenzothiazyl disul?de; di(pentachlorophe benzene; t-butylperoxybenzoate; 2,5-dimethyl-2,5-di-(t nyl) disul?de; dibenzamido diphenyldisul?de (DBDD), and butylperoxy)hexyne-3, such as Trigonox 145-45B, marketed 50 alkylated phenol sul?des, such as VULTAC marketed by Ato by Akrochem Corp. of Akron, Ohio; 1,1-bis(t-butylperoxy) ?na Chemicals, Inc. of Philadelphia, Pa. Preferred organic 3,3,5 tr‘i-methylcyclohexane, such as Varox 231-XL, mar sulfur compounds include pentachlorothiophenol, and diben keted by R. T. Vanderbilt Co., Inc., of NorWalk, Conn.; and zamido diphenyldisul?de. di-(2,4-dichlorobenzoyl)peroxide. Examples of the metal salt of an organic sulfur compound The cross-linking agents are blended With the polymeric 55 include, Without limitation, sodium, potassium, lithium, mag material in effective amounts, Which typically vary in total nesium calcium, barium, cesium and zinc salts of the above amounts of from about 0.05 part to about 5 parts, more pref mentioned thiophenols and thiocarboxylic acids, With the erably about 0.2 part to about 3 parts, and most preferably zinc salt of pentachlorothiophenol being most preferred. about 0.2 part to about 2 parts, by Weight of the cross-linking Examples of the non-metal salt of an organic sulfur com agents per 100 parts by Weight of the polyalkenamer rubber. 60 pound include, Without limitation, ammonium salts of the Each peroxide cross-linking agent has a characteristic above-mentioned thiophenols and thiocarboxylic acids decomposition temperature at Which 50% of the cross-linking Wherein the ammonium cation has the general formula agent has decomposed When subjected to that temperature for [NRlRzR3R‘l]+ Where R1, R2, R3 and R4 are selected from the a speci?ed time period (t 1 /2). For example, 1,1-bis-(t-butylp group consisting of hydrogen, a Cl-C2O aliphatic, eroxy)-3,3,5-tr‘i-methylcyclohexane at tl/2:0.1 hr has a 65 cycloaliphatic or aromatic moiety, and any and all combina decomposition temperature of 1380 C. and 2,5-dimethyl-2,5 tions thereof, With the most preferred being the NH4+-salt of di-(t-butylperoxy)hexyne-3 at t1/2:0.1 hr has a decomposi pentachlorothiophenol. US 7,874,940 B2 15 16 The peptizer, if employed to manufacture golf balls of the about 2.0 to about 3.5, and most preferably from about 2.2 to present invention, is present in an amount of from about 0.01 about 3 .2. The polybutadiene rubbers have a Mooney viscos parts to about 10 parts by Weight, preferably of from about ity (ML1+4 (100° C.)) of from about —10 to about 80, prefer 0.10 parts to about 7 parts by Weight, more preferably of from ably from about 20 to about 70, even more preferably from about 0.15 parts to about 5 parts by Weight per 100 parts by about 30 to about 60, and most preferably from about 35 to Weight of the polyalkenamer rubber component. about 50. “Mooney viscosity” refers to an industrial index of 4. Accelerators viscosity as measured With a Mooney viscometer, Which is a The polyalkenamer rubber composition also can comprise type of rotary plastometer (see J IS K6300). This value is one or more accelerators of one or more classes. Accelerators represented by the symbol ML1+4 (100° C.), Wherein “M” are added to an unsaturated polymer to increase the vulcani stands for Mooney viscosity, “L” stands for large rotor zation rate and/or decrease the vulcanization temperature. (L-type), “1 +4” stands for a pre-heating time of 1 minute and Accelerators can be of any class knoWn for rubber processing a rotor rotation time of 4 minutes, and “100° C.” indicates that including mercapto-, sulfenamide-, thiuram, dithiocarbam measurement Was carried out at a temperature of 100° C. ate, dithiocarbamyl-sulfenamide, xanthate, guanidine, Examples of 1 ,2-polybutadienes having differing tacticity, amine, thiourea, and dithiophosphate accelerators. Speci?c all of Which are suitable as unsaturated polymers for use in the commercial accelerators include 2-mercaptobenzothiazole present invention, are atactic 1,2-polybutadienes, isotactic and its metal or non-metal salts, such as Vulkacit Mercapto C, 1,2-polybutadienes, and syndiotactic 1,2-polybutadienes. Mercapto MGC, Mercapto ZM-5, and ZM marketed by Syndiotactic 1,2-polybutadienes having crystallinity suitable Bayer AG of Leverkusen, Germany, Nocceler M, Nocceler for use as an unsaturated polymer in compositions Within the MZ, and Nocceler M-60 marketed by Ouchisinko Chemical 20 scope of the present invention are polymerized from a 1,2 Industrial Company, Ltd. of Tokyo, Japan, and MBT and addition of butadiene. Golf balls Within the scope of the ZMBT marketed by Akrochem Corporation of Akron, Ohio. present invention include syndiotactic 1,2-polybutadienes A more complete list of commercially available accelerators having crystallinity and greater than about 70% of 1 ,2-bonds, is given in The Vanderbilt Rubber Handbook: 13”’ Edition more preferably greater than about 80% of 1,2-bonds, and (1990, R. T. Vanderbilt Co.), pp. 296-330, in Encyclopedia of 25 most preferably greater than about 90% of 1,2-bonds. Also, Polymer Science and Technology, Vol. 12 (1970, John golf balls Within the scope of the present invention not only Wiley & Sons), pp. 258-259, and in Rubber Technology have such crystallinity but also have a mean molecular Weight Handbook (1980, Hanser/ Gardner Publications), pp. of betWeen from about 10,000 to about 350,000, more pref 234-236. Preferred accelerators include 2-mercaptoben erably betWeen from about 50,000 to about 300,000, more zothiazole (MBT) and its salts. 30 preferably betWeen from about 80,000 to about 200,000, and The polyalkenamer rubber composition can further incor mo st preferably betWeen from about 10,000 to about 150,000. porate from about 0.1 part to about 10 parts by Weight of the Examples of suitable syndiotactic 1,2-polybutadienes having accelerator per 100 parts by Weight of the polyalkenamer crystallinity suitable for use in golf balls Within the scope of rubber. More preferably, the ball composition can further the present invention are sold under the trade names RB810, incorporate from about 0.2 part to about 5 parts, and most 35 RB820, and RB830 by JSR Corporation of Tokyo, Japan. preferably from about 0.5 part to about 1.5 parts, by Weight of These have more than 90% of 1,2 bonds, a mean molecular the accelerator per 100 parts by Weight of the polyalkenamer Weight of approximately 120,000, and crystallinity betWeen rubber. about 15% and about 30%.

C. Synthetic and Natural Rubbers 40 D. Thermoplastic Materials Traditional rubber components used in golf ball applica 1. Ole?nic Thermoplastic Elastomers tions can be used to make golf balls according to the present Examples of ole?nic thermoplastic elastomers include, invention including, Without limitation, both natural and syn Without limitation, metallocene-catalyzed polyole?ns, ethyl thetic rubbers, such as cis-1,4-polybutadienes, trans-1,4-po ene-octene copolymers, ethylene-butene copolymers, and lybutadienes, 1,2-polybutadienes, cis-polyisoprenes, trans 45 ethylene-propylene copolymers all With or Without controlled polyisoprenes, polychloroprenes, polybutylenes, styrene tacticity as Well as blends of polyole?ns having ethyl-propy butadiene rubbers, styrene-butadiene-styrene block lene-non-conjugated diene terpolymers, rubber-based copolymers and partially and fully hydrogenated equivalents, copolymers, and dynamically vulcanized rubber-based styrene-isoprene-styrene block copolymers and partially and copolymers. Examples of such polymers that are commer fully hydrogenated equivalents, nitrile rubbers, silicone rub 50 cially available include products sold under the trade names bers, and polyurethanes, as Well as mixtures of these materi SANTOPRENE, DYTRON, VISAFLEX, and VYRAM by als. Polybutadiene rubbers, especially 1,4-polybutadiene rub Advanced Elastomeric Systems of Houston, Tex., and SAR bers containing at least 40 mol %, and more preferably 80 to LINK by DSM of Haarlen, the Netherlands. 100 mol % of cis-1,4 bonds, are preferred because of their 2. Co-Polyester Thermoplastic Elastomers high rebound resilience, moldability, and high strength after 55 Examples of copolyester thermoplastic elastomers include vulcanization. The polybutadiene component may be pur polyether ester block copolymers, polylactone ester block chased, if commercially available, or synthesized by methods copolymers, and aliphatic and aromatic dicarboxylic acid noW knoWn or hereafter developed, including using rare copolymerized polyesters. Polyether ester block copolymers earth-based catalysts, nickel-based catalysts, or cobalt-based are copolymers comprising polyester hard segments poly catalysts, that conventionally are used in this ?eld. Polybuta 60 merized from a dicarboxylic acid and a loW molecular Weight diene obtained by using lanthanum rare earth-based catalysts diol, and polyether soft segments polymerized from an alky usually employ a combination of a lanthanum rare earth lene glycol having 2 to 10 atoms. Polylactone ester block (atomic number of 57 to 71) compound, but particularly pre copolymers are copolymers having polylactone chains ferred is a neodymium compound. instead of polyether as the soft segments discussed above for The 1,4-polybutadiene rubbers have a molecular Weight 65 polyether ester block copolymers. Aliphatic and aromatic distribution (MW/Mn) of from about 1.2 to about 4.0, prefer dicarboxylic copolymerized polyesters are copolymers of an ably from about 1.7 to about 3.7, even more preferably from acid component selected from aromatic dicarboxylic acids, US 7,874,940 B2 17 1 8 such as terephthalic acid and isophthalic acid, and aliphatic late-methacrylic anhydride terpolymer, sold under the trade acids having 2 to 10 carbon atoms With at least one diol name BONDINEAX 8390 and 8060 by Sumitomo Chemical component, selected from aliphatic and alicyclic diols having Industries; brominated styrene-isobutylene copolymers sold 2 to 10 carbon atoms. Blends of aromatic polyester and ali under the trade name BROMO XP-50 by Exxon Mobil Cor phatic polyester also may be used for these. Examples of poration; and resins having glycidyl or maleic anhydride these include products marketed under the trade names functional groups sold under the trade name LOTADER by HYTREL by El. DuPont de Nemours & Company, and Elf Atochem of Puteaux, France. SKYPEL by S.K. Chemicals of Seoul, South Korea. 4. Polyamides 3. Other Thermoplastic Elastomers Examples of polyamides Within the scope of the present Examples of other thermoplastic elastomers include multi invention include resins obtained by: (1) polycondensation of block, rubber-based copolymers, particularly those in Which (a) a dicarboxylic acid, such as oxalic acid, adipic acid, seba the rubber block component is based on butadiene, isoprene, cic acid, terephthalic acid, isophthalic acid, or 1,4-cyclohex or ethylene/butylene. The non-rubber repeating units of the anedicarboxylic acid, With (b) a diamine, such as ethylenedi copolymer may be derived from any suitable monomer, amine, tetramethylenediamine, pentamethylenediamine, including meth(acrylate) esters, such as methyl methacrylate hexamethylenediamine, decamethylenediamine, 1,4-cyclo and cyclohexylmethacrylate, and vinyl arylenes, such as sty hexyldiamine or m-xylylenediamine; (2) a ring-opening rene. Styrenic block copolymers are copolymers of styrene polymeriZation of cyclic lactam, such as e-caprolactam or With butadiene, isoprene, or a mixture of the tWo. Additional uu-laurolactam; (3) polycondensation of an aminocarboxylic unsaturated monomers may be added to the structure of the acid, such as 6-aminocaproic acid, 9-aminononanoic acid, styrenic block copolymer as needed for property modi?cation 20 11-aminoundecanoic acid or 12-aminododecanoic acid; or of the resulting SBC/urethane copolymer. The styrenic block (4) copolymeriZation of a cyclic lactam With a dicarboxylic copolymer can be a diblock or a triblock styrenic polymer. acid and a diamine. Speci?c examples of suitable polyamides Examples of such styrenic block copolymers are described in, include polyamide 6; polyamide 11; polyamide 12; polya for example, US. Pat. No. 5,436,295 to NishikaWa et al., mide 4,6; polyamide 6,6; polyamide 6,9; polyamide 6,10; Which is incorporated herein by reference. The styrenic block 25 polyamide 6,12; PAl2CX; PA12, IT; PPA; PA6, IT. copolymer can have any knoWn molecular Weight for such Non-limiting examples of suitable polyamides or copoly polymers, and it can possess a linear, branched, star, dendrim meric polyamides for use in the inner mantle and/or the outer eric or combination molecular structure. The styrenic block mantle layer include those sold under the trademarks, copolymer can be unmodi?ed by functional groups, or it can PEBAX, CRISTAMID and RILSAN marketed by ATOFINA be modi?ed by hydroxyl group, carboxyl group, or other 30 Chemicals of Philadelphia, Pa., GRILAMID marketed by functional groups, either in its chain structure or at one or EMS CHEMIE of Sumter, SC, and ZYTEL marketed by El. more terminus. The styrenic block copolymer canbe obtained DuPont de Nemours & Co. of Wilmington, Del. using any common process for manufacture of such poly 5. Polyamide Elastomer mers. The styrenic block copolymers also may be hydroge Examples of polyamide elastomers Within the scope of the nated using Well-knoWn methods to obtain a partially or fully 35 present invention include polyether amide elastomers, Which saturated diene monomer block. Examples of styrenic result from the copolycondensation of polyamide blocks hav copolymers include, Without limitation, resins manufactured ing reactive chain ends With polyether blocks having reactive by Kraton Polymers (formerly of Shell Chemicals) under the chain ends, including: 1) polyamide blocks of diamine chain trade names KRATON D (for styrene-butadiene-styrene and ends With polyoxyalkylene sequences of dicarboxylic chain styrene-isoprene-styrene types), and KRATON G (for sty 40 ends; 2) polyamide blocks of dicarboxylic chain ends With rene-ethylene-butylene-styrene and styrene-ethylene-propy polyoxyalkylene sequences of diamine chain ends obtained lene-styrene types) and Kuraray under the trade name SEP by cyanoethylation and hydrogenation of polyoxyalkylene TON. Examples of randomly distributed styrenic polymers alpha-omega dihydroxylated aliphatic sequences knoWn as include paramethylstyrene-isobutylene (isobutene) copoly polyether diols; and 3) polyamide blocks of dicarboxylic mers developed by ExxonMobil Chemical Corporation and 45 chain ends With polyether diols, the products obtained, in this styrene-butadiene random copolymers developed by Chev particular case, being polyetheresteramides. ron Phillips Chemical Corporation. The polyamide blocks of dicarboxylic chain ends come, for Examples of other thermoplastic elastomers suitable as example, from the condensation of alpha-omega aminocar additional polymer components in the present invention boxylic acids of lactam or of carboxylic diacids and diamines include those having functional groups, such as carboxylic 50 in the presence of a carboxylic diacid Which limits the chain acid, maleic anhydride, glycidyl, norbonene, and hydroxyl length. The molecular Weight of the polyamide sequences functionalities. An example of these includes a block polymer preferably is betWeen about 300 and about 15,000, and more having at least one polymer block A comprising an aromatic preferably betWeen about 600 and about 5,000. The molecu vinyl compound and at least one polymer block B comprising lar Weight of the polyether sequences preferably is betWeen a conjugated diene compound, and having a hydroxyl group 55 about 100 and about 6,000, and more preferably betWeen at the terminal block copolymer, or its hydrogenated product. about 200 and about 3,000. An example of this polymer is sold under the trade name The amide block polyethers also may comprise randomly SEPTON HG-252 by Kuraray Company of Kurashiki, Japan. distributed units. These polymers may be prepared by the Other examples of these include: maleic anhydride function simultaneous reaction of polyether and precursor of polya aliZed triblock copolymer consisting of polystyrene end 60 mide blocks. blocks and poly(ethylene/butylene), sold under the trade For example, the polyether diol may react With a lactam (or name KRATON FG 1901X by Shell Chemical Company; alpha-omega amino acid) and a diacid Which limits the chain maleic anhydride modi?ed ethylene-vinyl acetate copolymer, in the presence of Water. A polymer is obtained having mainly sold under the trade name FUSABOND by El. DuPont de polyether blocks, polyamide blocks of very variable length, Nemours & Company; ethylene-isobutyl acrylate-meth 65 but also the various reactive groups having reacted in a ran acrylic acid terpolymer, sold under the trade name NUCREL dom manner and Which are distributed statistically along the by El. DuPont de Nemours & Company; ethylene-ethyl acry polymer chain. US 7,874,940 B2 19 20 Suitable amide block polyethers include, Without limita 2,2,4-trimethyl hexamethylene diisocyanates, dodecameth tion, those disclosed in Us. Pat. Nos. 4,331,786, 4,115,475, ylene diisocyanates, 1,3cyclopentane diisocyanates, 1,3-cy 4,195,015, 4,839,441, 4,864,014, 4,230,838, and 4,332,920, clohexane diisocyanates, 1,3-cyclobutane diisocyanates, 1,4 Which are incorporated herein in their entireties by reference. cyclohexane diisocyanates, 4,4'-methylenebis(cyclohexyl The polyether may be, for example, a polyethylene glycol isocyanates), 4,4'-methylenebis(phenyl isocyanates), 1-me (PEG), a polypropylene glycol (PPG), or a polytetramethyl thyl-2,4-cyclohexane diisocyanates, 1-methyl-2,6-cyclohex ene glycol (PTMG), also designated as polytetrahydrofurane ane diisocyanates, 1,3-bis (isocyanato-methyl)cyclohexanes, (PTHF). 1,6-diisocyanato-2,2,4,4-tetra-methylhexanes, 1,6-diisocy The polyether blocks may be along the polymer chain in anato -2,4,4-tetra-trimethylhexanes, trans-cyclohexane-l ,4 the form of diols or diamines. However, for reasons of sim diisocyanates, 3-isocyanato-methyl-3,5,5-trimethylcyclo pli?cation, they are designated PEG blocks, or PPGblocks, or hexyl isocyanates, 1 -isocyanato -3 ,3 ,5 -trimethyl-5 - also PTMG blocks. isocyanatomethylcyclohexanes, cyclohexyl isocyanates, It is also Within the scope of the disclosed embodiments dicyclohexylmethane 4,4'-diisocyanates, 1,4-bis(isocy that the polyether block comprises different units such as anatomethyl) cyclohexanes, m-phenylene diisocyanate, units, Which derive from ethylene glycol, propylene glycol, or m-xylylene diisocyanate, m-tetramethylxylylene diisocyan tetramethylene glycol. ates, p-phenylene diisocyanate, p,p'-biphenyl diisocyanates, The amide block polyether comprises at least one type of 3,3'-dimethyl-4,4'-biphenylene diisocyanates, 3,3' polyamide block and one type of polyether block. Mixing tWo dimethoxy-4,4'-biphenylene diisocyanates, 3,3'-diphenyl-4, or more polymers With polyamide blocks and polyether 4'-biphenylene diisocyanates, 4,4'-biphenylene diisocyan blocks also may be used. It also can comprise any amide 20 ates, 3,3'-dichloro-4,4'-biphenylene diisocyanates, 1,5 structure made from the method described on the above. naphthalene diisocyanates, 4-chloro- 1 ,3-phenylene Preferably, the amide block polyether is such that it repre diisocyanates, 1 ,5 -tetrahydronaphthalene diisocyanates, sents the major component in Weight, i.e., that the amount of meta-xylene diisocyanates, 2,4-toluene diisocyanates, 2,4‘ polyamide Which is under the block con?guration and that diphenylmethane diisocyanates, 2,4-chlorophenylene diiso Which is eventually distributed statistically in the chain rep 25 cyanates, 4,4'-diphenylmethane diisocyanates, p,p'-diphenyl resents 50 Weight percent or more of the amide block poly methane diisocyanate, 2,4-tolylene diisocyanates, 2,6 ether. Advantageously, the amount of polyamide and the tolylene diisocyanates, 2,2-diphenylpropane-4,4' amount of polyether is in a ratio (polyamide/polyether) of diisocyanate, 4,4'-toluidine diisocyanates, dianisidine about 1:1 to about 3:1. diisocyanates, 4,4'-diphenyl ether diisocyanates, 1,3-xy One type of polyetherester elastomer is the family of 30 lylene diisocyanates, 1,4-naphthylene diisocyanates, aZoben Pebax, Which are available from Elf-Atochem Company. Zene-4,4'-diisocyanates, diphenyl sulfone-4,4'-diisocyanates, Preferably, the choice can be made from among Pebax 2533, triphenylmethane 4,4',4"-triisocyanates, isocyanatoethyl 3533, 4033, 1205, 7033, and 7233. Blends or combinations of methacrylates, 3-isopropenyl-ot,(x-dimethylbenZyl-isocyan Pebax 2533, 3533, 4033, 1205, 7033, and 7233 also can be ates, dichlorohexamethylene diisocyanates, u),u)'-diisocy prepared, as Well. Pebax 2533 has a hardness of about 25 35 anato-1,4-diethylbenZenes, polymethylene polyphenylene shore D (according to ASTM D-2240), a Flexural Modulus of polyisocyanates, polybutylene diisocyanates, isocyanurate about 2.1 kpsi (according to ASTM D-790), and a Bayshore modi?ed compounds, and carbodiimide modi?ed com resilience of about 62% (according to ASTM D-2632). Pebax pounds, as Well as biuret modi?ed compounds of the above 3533 has a hardness of about 35 shore D (according to ASTM polyisocyanates. Each isocyanate may be used either alone or D-2240), a Flexural Modulus of about 2.8 kpsi (according to 40 in combination With one or more other isocyanates. These ASTM D-790), and a Bayshore resilience of about 59% (ac isocyanate mixtures can include triisocyanates, such as biuret cording to ASTM D-2632). Pebax 7033 has a hardness of of hexamethylene diisocyanate and triphenylmethane triiso about 69 shore D (according to ASTM D-2240) and a Flexural cyanate, and polyisocyanates, such as polymeric diphenyl Modulus of about 67 kpsi (according to ASTM D-790). Pebax methane diisocyanate. 7333 has a hardness of about 72 shore D (according to ASTM 45 Polyols used for making the polyurethane in the copolymer D-2240) and a Flexural Modulus of about 107 kpsi (according include polyester polyols, polyether polyols, polycarbonate to ASTM D-790). polyols and polybutadiene polyols. Polyester polyols are pre 6. Thermoplastic Polyurethanes pared by condensation or step-groWth polymeriZation utiliZ Another example of an additional polymer component ing diacids. Primary diacids for polyester polyols are adipic includes the thermoplastic polyurethanes, Which are the reac 50 acid and isomeric phthalic acids. Adipic acid is used for tion product of a diol or polyol and an isocyanate, With or materials requiring added ?exibility, Whereas phthalic anhy Without a chain extender. Thermoplastic polyurethanes are dride is used for those requiring rigidity. Some examples of described in the patent literature, and some are knoWn for use polyester polyols include poly(ethylene adipate) (PEA), poly in making golf ball cores. See, for example, Vedula et al., U.S. (diethylene adipate) (PDA), poly(propylene adipate) (PPA), Pat. No. 5,959,059. 55 poly(tetramethylene adipate) (PBA), poly(hexamethylene lsocyanates used for making the urethanes of the present adipate) (PHA), poly(neopentylene adipate) (PNA), polyols invention encompass diisocyanates and polyisocyanates. composed of 3-methyl-1,5-pentanediol and adipic acid, ran Examples of suitable isocyanates include the folloWing: tri dom copolymer of PEA and PDA, random copolymer of PEA methylene diisocyanates, tetramethylene diisocyanates, pen and PPA, random copolymer of PEA and PBA, random tamethylene diisocyanates, hexamethylene diisocyanates, 60 copolymer of PHA and PNA, caprolactone polyol obtained ethylene diisocyanates, diethylidene diisocyanates, propy by the ring-opening polymerization of E-caprolactone, and lene diisocyanates, butylene diisocyanates, bitolylene diiso polyol obtained by opening the ring of [3-methyl-6-valerolac cyanates, tolidine isocyanates, isophorone diisocyanates, tone With ethylene glycol can be used either alone or in a dimeryl diisocyanates, dodecane-l,12-diisocyanates, 1,10 combination thereof. Additionally, polyester polyols may be decamethylene diisocyanates, cyclohexylene-1,2-diisocyan 65 composed of a copolymer of at least one of the folloWing ates, 1-chlorobenZene-2,4-diisocyanates, furfurylidene acids and at least one of the folloWing glycols. The acids diisocyanates, 2,4,4-trimethyl hexamethylene diisocyanates include terephthalic acid, isophthalic acid, phthalic anhy US 7,874,940 B2 21 22 dride, oxalic acid, malonic acid, succinic acid, pentanedioic phenol. Aromatic diamines have a tendency to provide a acid, hexanedioic acid, octanedioic acid, nonanedioic acid, stiffer (i.e., having a higher Mooney viscosity) product than adipic acid, aZelaic acid, sebacic acid, dodecanedioic acid, aliphatic or cycloaliphatic diamines. A chain extender may be dimer acid (a mixture), p-hydroxybenZoate, trimellitic anhy used either alone or in a mixture. dride, e-caprolactone, and [3-methyl-6-valerolactone. The 7. Ethylenically Unsaturated Thermoplastic Elastomers glycols includes ethylene glycol, propylene glycol, butylene Another family of thermoplastic elastomers for use in the glycol, pentylene glycol, 1,4-butanediol, 1,5-pentanediol, golf balls of the present invention are polymers of (i) ethylene 1,6-hexanediol, neopentylene glycol, polyethylene glycol, and/or an alpha ole?n; and (ii) an 0t,[3-ethylenically unsatur polytetramethylene glycol, 1,4-cyclohexane dimethanol, ated C3 -C20 carboxylic acid or anhydride, or an 0t,[3-ethyleni pentaerythritol, and 3-methyl-1,5-pentanediol. cally unsaturated C3-C2O sulfonic acid or anhydride or an Polyether polyols are prepared by the ring-opening addi 0t,[3-ethylenically unsaturated C3-C2O phosphoric acid or tion polymerization of an alkylene oxide (e.g. ethylene oxide anhydride and, optionally iii) a C l-C 1O ester of an 0t,[3-ethyl and propylene oxide) With an initiator of a polyhydric alcohol enically unsaturated C3 -C20 carboxylic acid or a C 1 -C 10 ester (e.g. diethylene glycol), Which is an active hydride. Speci? of an 0t,[3-ethylenically unsaturated C3-C2O sulfonic acid or a cally, polypropylene glycol (PPG), polyethylene glycol Cl-Cl0 ester of an uoL-ethylenically unsaturated C3-C2O (PEG) or propylene oxide-ethylene oxide copolymer can be phosphoric acid. obtained. Polytetramethylene ether glycol (PTMG) is pre Preferably, the alpha-ole?n has from 2 to 10 carbon atoms pared by the ring-opening polymerization of tetrahydrofuran, and is preferably ethylene, and the unsaturated carboxylic produced by dehydration of 1,4-butanediol or hydrogenation acid is a carboxylic acid having from about 3 to 8 carbons. of furan. Tetrahydrofuran can form a copolymer With alky 20 Examples of such acids include acrylic acid, methacrylic lene oxide. Speci?cally, tetrahydrofuran-propylene oxide acid, ethacrylic acid, chloroacrylic acid, crotonic acid, maleic copolymer or tetrahydrofuran-ethylene oxide copolymer can acid, fumaric acid, and itaconic acid, With acrylic acid being be formed. A polyether polyol may be used either alone or in preferred. Preferably, the carboxylic acid ester of if present a mixture. may be selected from the group consisting of vinyl esters of Polycarbonate polyols are obtained by the condensation of 25 aliphatic carboxylic acids Wherein the acids have 2 to 10 a knoWn polyol (polyhydric alcohol) With phosgene, chloro carbon atoms and vinyl ethers Wherein the alkyl groups con formic acid ester, dialkyl carbonate or diallyl carbonate. A tain 1 to 10 carbon atoms. particularly preferred polycarbonate polyol contains a polyol Examples of such polymers suitable for use as include, but component using 1,6-hexanediol, 1,4-butanediol, 1,3-bu are not limited to, an ethylene/acrylic acid copolymer, an tanediol, neopentylglycol or 1,5-pentanediol. A polycarbon 30 ethylene/methacrylic acid copolymer, an ethylene/itaconic ate polyol can be used either alone or in a mixture. acid copolymer, an ethylene/maleic acid copolymer, an eth Polybutadiene polyols include liquid diene polymer con ylene/methacrylic acid/vinyl acetate copolymer, an ethylene/ taining hydroxyl groups, and an average of at least 1.7 func acrylic acid/vinyl alcohol copolymer, and the like. tional groups, and may be composed of diene polymers or Most preferred are ethylene/(meth)acrylic acid copoly diene copolymers having 4 to 12 carbon atoms, or a copoly 35 mers and ethylene/(meth)acrylic acid/alkyl (meth)acrylate mer of such diene With addition to polymeriZable ot-ole?n terpolymers, or ethylene and/or propylene maleic anhydride monomer having 2 to 2.2 carbon atoms. Speci?c examples copolymers and terpolymers. include butadiene homopolymer, isoprene homopolymer, The acid content of the polymer may contain anyWhere butadiene-styrene copolymer, butadiene-isoprene copoly from 1 to 30 percent by Weight acid. In some instances, it is mer, butadiene-acrylonitrile copolymer, butadiene-2-ethyl 40 preferable to utiliZe a high acid copolymer (i.e., a copolymer hexyl acrylate copolymer, and butadiene-n-octadecyl acry containing greater than 16% by Weight acid, preferably from late copolymer. These liquid diene polymers can be obtained, about 17 to about 25 Weight percent acid, and more preferably for example, by heating a conjugated diene monomer in the about 20 Weight percent acid). presence of hydrogen peroxide in a liquid reactant. A polyb Examples of such polymers Which are commercially avail utadiene polyol can be used either alone or in a mixture. 45 able include, but are not limited to, the Escor® 5000, 5001, Urethanes used to practice the present invention also may 5020, 5050, 5070, 5100, 5110 and 5200 series of ethylene incorporate chain extenders. Non-limiting examples of these acrylic acid copolymers sold by Exxon and the PRIMA extenders include polyols, polyamine compounds, and mix COR® 1321, 1410, 1410-XT, 1420, 1430, 2912, 3150, 3330, tures of these. Polyol extenders may be primary, secondary, or 3340, 3440, 3460, 4311 and 4608 series of ethylene-acrylic tertiary polyols. Speci?c examples of monomers of these 50 acid copolymers sold by The DoW Chemical Company, Mid polyols include: trimethylolpropane (TMP), ethylene glycol, land, Mich. 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hex Also included are the bimodal ethylene/carboxylic acid anediol, propylene glycol, dipropylene glycol, 1,2-butane polymers as described in US. Pat. No. 6,562,906, the entire diol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3 contents of Which are herein incorporated by reference. These pentanediol, 2,5-hexanediol, 2,4-hexanediol, 2-ethyl-1,3 55 polymers comprise ethylene/0t,[3-ethylenically unsaturated hexanediol, cyclohexanediol, and 2-ethyl-2 C3_8 carboxylic acid high copolymers, particularly ethylene (hydroxymethyl)- 1 ,3 -propanediol. (meth)acrylic acid copolymers and ethylene, alkyl (meth) Suitable polyamines that may be used as chain extenders acrylate, (meth)acrylic acid terpolymers, having molecular include primary, secondary and tertiary amines; polyamines Weights of about 80,000 to about 500,000 Which are melt have tWo or more amines as functional groups. Examples of 60 blended With ethylene/0t,[3-ethylenically unsaturated C3_8 these include: aliphatic diamines, such as tetramethylenedi carboxylic acid copolymers, particularly ethylene/(meth) amine, pentamethylenediamine, hexamethylenediamine; ali acrylic acid copolymers having molecular Weights of about cyclic diamines, such as 3,3'-dimethyl-4,4'-diamino-dicyclo 2,000 to about 30,000. hexyl methane; or aromatic diamines, such as 4,4'-methylene 8. lonomers bis-2-chloroaniline, 2,2',3,3'-tetrachloro-4,4'-diaminophenyl 65 The core, cover layer and, optionally, one or more inner methane, p,p'-methylenedianiline, p-phenylenediamine or cover layers golf ball embodiments of the present invention 4,4'-diaminodiphenyl; and 2,4,6-tris(dimethylaminomethyl) may further comprise one or more ionomer resins. One family US 7,874,940 B2 23 24 of such resins Was developed in the mid-1960’s, by E.l. E/X/Y, Where E is ethylene, X is a softening comonomer DuPont de Nemours and Co., and sold under the trademark such as present in an amount of from 0 Weight percent to SURLYN®. Preparation of such ionomers is Well known, for about 50 Weight percent of the polymer, andY is present in an example see U.S. Pat. No. 3,264,272 (the entire contents of amount from about 5 Weight percent to about 35 Weight Which are herein incorporated by reference). Generally 5 percent of the polymer, and Wherein the acid moiety is neu speaking, most commercial ionomers are unimodal and con traliZed from about 1% to about 90% to form an ionomer With sist of a polymer of a mono-ole?n, e.g., an alkene, With an a cation such as lithium, sodium, potassium, magnesium, unsaturated mono- or dicarboxylic acids having 3 to 12 car calcium, barium, lead, tin, Zinc or aluminum, or a combina bon atoms. An additional monomer in the form of a mono- or tion of such cations. dicarboxylic acid ester also may be incorporated in the for The ionomer also may be a so-called bimodal ionomer as mulation as a so-called “softening comonomer”. The incor described in Us. Pat. No. 6,562,906 (the entire contents of porated carboxylic acid groups are then neutraliZed by a basic Which are herein incorporated by reference). These ionomers metal ion salt, to form the ionomer. The metal cations of the are bimodal as they are prepared from blends comprising basic metal ion salt used for neutralization include Li", Na", polymers of different molecular Weights. Speci?cally they K", Zn“, Ca2+, C02", Ni2+, Cu2+, Pb2+, and Mg2+, With the include bimodal polymer blend compositions comprising: Li", Na", Ca2+, Zn“, and Mg2+ being preferred. The basic a high molecular Weight component having molecular metal ion salts include those of, for example, formic acid, Weight of about 80,000 to about 500,000 and comprising one acetic acid, nitric acid, and carbonic acid, hydrogen carbonate or more ethylene/0t,[3-ethylenically unsaturated C3_8 car salts, oxides, hydroxides, and alkoxides. boxylic acid copolymers and/or one or more ethylene, alkyl The ?rst commercially available ionomer resins contained 20 (meth)acrylate, (meth)acrylic acid terpolymers; the high up to 16 Weight percent acrylic or methacrylic acid, although molecular Weight component being partially neutraliZed With it also Was Well knoWn at that time that, as a general rule, the metal ions selected from the group consisting of lithium, hardness of these cover materials could be increased With sodium, Zinc, calcium, magnesium, and a mixture of any increasing acid content. Hence, in Research Disclosure these; and 29703, published in January 1989, DuPont disclosed iono 25 a loW molecular Weight component having a molecular mers based on ethylene/acrylic acid or ethylene/methacrylic Weight of from about 2,000 to about 30,000 and comprising acid containing acid contents of greater than 15 Weight per one or more ethylene/0t,[3-ethylenically unsaturated C3_8 car cent. In this same disclosure, DuPont also taught that such so boxylic acid copolymers and/or one or more ethylene, alkyl called “high acid ionomers” had signi?cantly improved stiff (meth)acrylate, (meth)acrylic acid terpolymers; the loW ness and hardness and thus could be advantageously used in 30 molecular Weight component being partially neutraliZed With golf ball construction, When used either singly or in a blend metal ions selected from the group consisting of lithium, With other ionomers. sodium, Zinc, calcium, magnesium, and a mixture of any More recently, high acid ionomers are typically de?ned as these. those ionomer resins With acrylic or methacrylic acid units In addition to the unimodal and bimodal ionomers, also present from 16 Weight percent to about 35 Weight percent in 35 included are the so-called “modi?ed ionomers” examples of the polymer. Generally, such a high acid ionomer Will have a Which are described in Us. Pat. Nos. 6,100,321, 6,329,458 ?exural modulus from about 50,000 psi to about 125,000 psi. and 6,616,552 and Us. Patent Publication US 2003/0158312 lonomer resins further comprising a softening comonomer, Al, the entire contents of all of Which are herein incorporated present from about 10 Weight percent to about 50 Weight by reference. percent in the polymer, have a ?exural modulus from about 40 The modi?ed unimodal ionomers are prepared by mixing: 2,000 psi to about 10,000 psi, and are sometimes referred to as “soft” or “very loW modulus” ionomers. Typical softening an ionomeric polymer comprising ethylene, from 5 to 25 comonomers include n-butyl acrylate, iso-butyl acrylate, Weight percent (meth)acrylic acid, and from 0 to 40 Weight n-butyl methacrylate, methyl acrylate and methyl methacry percent of a (meth)acrylate monomer, the ionomeric polymer neutraliZed With metal ions selected from the group consist late. 45 Today, there are a Wide variety of commercially available ing of lithium, sodium, Zinc, calcium, magnesium, and a ionomer resins based both on copolymers of ethylene and mixture of any these, and (meth)acrylic acid or terpolymers of ethylene and (meth) from about 5 to about 40 Weight percent (based on the total acrylic acid and (meth)acrylate, all of Which many of Which Weight of said modi?ed ionomeric polymer) of one or more are be used as a golf ball component. The properties of these 50 fatty acids or metal salts of said fatty acid, the metal selected ionomer resins can vary Widely due to variations in acid from the group consisting of calcium, sodium, Zinc, potas content, softening comonomer content, the degree of neutral sium, and lithium, barium and magnesium and the fatty acid iZation, and the type of metal ion used in the neutralization. preferably being stearic acid. The full range commercially available typically includes The modi?ed bimodal ionomers, Which are ionomers ionomers of polymers of general formula, E/X/Y polymer, 55 derived from the earlier described bimodal ethylene/carboxy Wherein E is ethylene, X is a C3 to C8 0t,[3-ethylenically lic acid polymers (as described in Us. Pat. No. 6,562,906, the unsaturated carboxylic acid, such as acrylic or methacrylic entire contents of Which are herein incorporated by refer acid, and is present in an amount from about 2 to about 30 ence), are prepared by mixing: Weight percent of the E/X/Y copolymer, andY is a softening a. a high molecular Weight component having molecular comonomer selected from the group consisting of alkyl acry 60 Weight of about 80,000 to about 500,000 and comprising one late and alkyl methacrylate, such as methyl acrylate or methyl or more ethylene/0t,[3-ethylenically unsaturated C3_8 car methacrylate, and Wherein the alkyl groups have from 1-8 boxylic acid copolymers and/or one or more ethylene, alkyl carbon atoms, Y is in the range of 0 to about 50 Weight percent (meth)acrylate, (meth)acrylic acid terpolymers; the high of the E/X/Y copolymer, and Wherein the acid groups present molecular Weight component being partially neutraliZed With in said ionomeric polymer are partially neutraliZed With a 65 metal ions selected from the group consisting of lithium, metal selected from the group consisting of Zinc, sodium, sodium, Zinc, calcium, potassium, magnesium, and a mixture lithium, calcium, magnesium, and combinations thereof. of any of these; US 7,874,940 B2 25 26 b. a loW molecular Weight component having a molecular An example of such a modi?ed ionomer polymer is Weight of about from about 2,000 to about 30,000 and com DuPont® HPF-l000 available from E. I. DuPont de Nemours prising one or more ethylene/0t,[3-ethylenically unsaturated and Co. Inc. C3_8 carboxylic acid copolymers and/or one or more ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers; the loW IV. Fillers molecular Weight component being partially neutraliZed With The polymeric compositions used to prepare the golf balls metal ions selected from the group consisting of lithium, of the present invention also can incorporate one or more sodium, Zinc, calcium, potassium, magnesium, and a mixture ?llers. Such ?llers are typically in a ?nely divided form, for of any of these; and example, in a siZe generally less than about 20 mesh, prefer c. from about 5 to about 40 Weight percent (based on the ably less than about 100 mesh U.S. standard siZe, except for total Weight of said modi?ed ionomeric polymer) of one or ?bers and ?ock, Which are generally elongated. Filler particle more fatty acids or metal salts of the fatty acid, the metal siZe Will depend upon desired effect, cost, ease of addition, and dusting considerations. The appropriate amounts of ?ller selected from the group consisting of calcium, sodium, Zinc, required Will vary depending on the application but typically potassium and lithium, barium and magnesium and the fatty can be readily determined Without undue experimentation. acid preferably being stearic acid. The ?ller preferably is selected from the group consisting The fatty or Waxy acid salts utiliZed in the various modi?ed of precipitated hydrated silica, limestone, clay, talc, asbestos, ionomers are composed of a chain of alkyl groups containing barytes, glass ?bers, aramid ?bers, mica, calcium metasili from about 4 to 75 carbon atoms (usually even numbered) and 20 cate, barium sulfate, Zinc sul?de, lithopone, silicates, silicon characteriZed by a 4COOH terminal group. The generic carbide, diatomaceous earth, carbonates such as calcium or formula for all fatty and Waxy acids above acetic acid is magnesium or barium carbonate, sulfates such as calcium or magnesium or barium sulfate, metals, including tungsten, CH3 (CH2 XCOOH, Wherein the carbon atom count includes steel, copper, cobalt or iron, metal alloys, tungsten carbide, the carboxyl group. The fatty or Waxy acids utiliZed to pro 25 metal oxides, metal stearates, and other particulate carbon duce the fatty or Waxy acid salts modi?ers may be saturated or aceous materials, and any and all combinations thereof. Pre unsaturated, and they may be present in solid, semi-solid or ferred examples of ?llers include metal oxides, such as Zinc liquid form. oxide and magnesium oxide. In another preferred embodi Examples of suitable saturated fatty acids, i.e., fatty acids ment the ?ller comprises a continuous or non-continuous in Which the carbon atoms of the alkyl chain are connected by 30 ?ber. In another preferred embodiment the ?ller comprises single bonds, include but are not limited to, stearic acid (C18, one or more so called nano?llers, as described inU.S. Pat. No. 6,794,447 and copending US. patent application Ser. No. i.e., CH3(CH2)l6COOH), palmitic acid (C16, i.e., CH3 10/ 670,090 ?led on Sep. 24, 2003 and copending US. patent (CH2)14COOH), pelargonic acid (C9, i.e., CH3(CH2)7 application Ser. No. l0/926,509 ?led on Aug. 25, 2004, the COOH) and lauric acid (C12, i.e., CH3(CH2)1OOCOOH). 35 entire contents of each of Which are incorporated herein by Examples of suitable unsaturated fatty acids, i.e., a fatty acid reference. in Which there are one or more double bonds betWeen the Inorganic nano?ller material generally is made of clay, carbon atoms in the alkyl chain, include but are not limited to such as hydrotalcite, phyllosilicate, saponite, hectorite, beid oleic acid (C13, i.e., CH3(CH2)7CH:CH(CH2)7COOH). ellite, stevensite, vermiculite, halloysite, mica, montmorillo The source of the metal ions used to produce the metal salts 40 nite, mica?uoride, or octosilicate. To facilitate incorporation of the fatty or Waxy acid salts used in the various modi?ed of the nano?ller material into a polymer material, either in preparing nanocomposite materials or in preparing polymer ionomers are generally various metal salts, Which provide the based golf ball compositions, the clay particles generally are metal ions capable of neutraliZing, to various extents, the coated or treated by a suitable compatibiliZing agent. The carboxylic acid groups of the fatty acids. These include the 45 compatibiliZing agent alloWs for superior linkage betWeen sulfate, carbonate, acetate and hydroxylate salts of Zinc, the inorganic and organic material, and it also can account for barium, calcium and magnesium. the hydrophilic nature of the inorganic nano?ller material and Since the fatty acid salts modi?ers comprise various com the possibly hydrophobic nature of the polymer. Compatibi binations of fatty acids neutraliZed With a large number of liZing agents may exhibit a variety of different structures different metal ions, several different types of fatty acid salts 50 depending upon the nature of both the inorganic nano?ller material and the target matrix polymer. Non-limiting may be utiliZed in the invention, including metal stearates, examples include hydroxy-, thiol-, amino-, epoxy-, carboxy laureates, oleates, and palmitates, With calcium, Zinc, sodium, lic acid-, ester-, amide-, and siloxy-group containing com lithium, potassium and magnesium stearate being preferred, pounds, oligomers or polymers. The nano?ller materials can and calcium and sodium stearate being most preferred. 55 be incorporated into the polymer either by dispersion into the The fatty or Waxy acid or metal salt of the fatty or Waxy acid particular monomer or oligomer prior to polymerization, or is present in the modi?ed ionomeric polymers in an amount of by melt compounding of the particles into the matrix polymer. from about 5 to about 40, preferably from about 7 to about 35, Examples of commercial nano?llers are various Cloisite more preferably from about 8 to about 20 Weight percent grades including 10A, 15A, 20A, 25A, 30B, and NA+ of Southern Clay Products (Gonzales, Tex.) and the Nanomer (based on the total Weight of said modi?ed ionomeric poly grades including 1 .24TL and C.30EVA of Nanocor, Inc. (Ar mer). lington Heights, Ill.). As a result of the addition of the one or more metal salts of As mentioned above, the nano?ller particles have an aggre a fatty or Waxy acid, from about 40 to 100, preferably from gate structure With the aggregates particle siZes in the micron about 50 to 100, more preferably from about 70 to 100 percent 65 range and above. HoWever, these aggregates have a stacked of the acidic groups in the ?nal modi?ed ionomeric polymer plate structure With the individual platelets being roughly composition are neutraliZed by a metal ion. from about 1 nanometer (nm) thick and from about 100 to US 7,874,940 B2 27 28 about 1000 nm across. As a result, nano?llers have extremely 1.14, While a conventional 30% mineral-?lled material has a high surface area, resulting in high reinforcement e?iciency tensile strength of 8,000 psi and a speci?c gravity of 1.36. to the material at loW loading levels of the particles. The Using nanocomposite materials With loWer inorganic materi sub-micron-siZed particles enhance the stiffness of the mate als loadings than conventional ?llers provides the same prop rial, Without increasing its Weight or opacity and Without erties, and this alloWs products comprising nanocomposite reducing the material’s loW-temperature toughness. ?llers to be lighter than those With conventional ?llers, While Nano?llers When added into a matrix polymer, such as the maintaining those same properties. polyalkenamer rubber, can be mixed in three Ways. In one Nanocomposite materials are materials incorporating from type of mixing there is dispersion of the aggregate structures about 0.1% to about 20%, preferably from about 0.1% to Within the matrix polymer, but on mixing no interaction of the about 15%, and most preferably from about 0.1% to about matrix polymer With the aggregate platelet structure occurs, 10% of nano?ller reacted into and substantially dispersed and thus the stacked platelet structure is essentially main through intercalation or exfoliation into the structure of an tained. As used herein, this type of mixing is de?ned as organic material, such as a polymer, to provide strength, “undispersed”. temperature resistance, and other property improvements to HoWever, if the nano?ller material is selected correctly, the the resulting composite. Descriptions of particular nanocom matrix polymer chains can penetrate into the aggregates and posite materials and their manufacture can be found in Us. separate the platelets, and thus When vieWed by transmission Pat. No. 5,962,553 to Ellsworth, U.S. Pat. No. 5,385,776 to electron microscopy or x-ray diffraction, the aggregates of Max?eld et al., and Us. Pat. No. 4,894,411 to Okada et al. platelets are expanded. At this point the nano?ller is said to be Examples of nanocomposite materials currently marketed substantially evenly dispersed Within and reacted into the 20 include M1030D, manufactured by Unitika Limited, of structure of the matrix polymer. T his level of expansion can Osaka, Japan, and 1015C2, manufactured by UBE America occur to differing degrees. If small amounts of the matrix of NeW York, N.Y. polymer are layered betWeen the individual platelets then, as When nanocomposites are blended With other polymer used herein, this type of mixing is knoWn as “intercalation”. systems, the nanocomposite may be considered a type of In some circumstances, further penetration of the matrix 25 nano?ller concentrate. HoWever, a nano?ller concentrate polymer chains into the aggregate structure separates the may be more generally a polymer into Which nano?ller is platelets, and leads to a complete disruption of the platelet’s mixed; a nano?ller concentrate does not require that the nano stacked structure in the aggregate. Thus, When vieWed by ?ller has reacted and/or dispersed evenly into the carrier transmission electron microscopy (TEM), the individual polymer. platelets are thoroughly mixed throughout the matrix poly 30 For the polyalkenamers, the nano?ller material is added in mer. As used herein, this type of mixing is knoWn as “exfoli an amount of from about 0.1% to about 20%, preferably from ated”. An exfoliated nano?ller has the platelets fully dis about 0.1% to about 15%, and most preferably from about persed throughout the polymer matrix; the platelets may be 0.1% to about 10% by Weight of nano?ller reacted into and dispersed unevenly but preferably are dispersed evenly. substantially dispersed through intercalation or exfoliation While not Wishing to be limited to any theory, one possible 35 into the structure of the polyalkenamer. explanation of the differing degrees of dispersion of such If desired, the various polymer compositions used to pre nano?llers Within the matrix polymer structure is the effect of pare the golf balls of the present invention can additionally the compatibiliZer surface coating on the interaction betWeen contain other conventional additives such as plasticiZers, pig the nano?ller platelet structure and the matrix polymer. By ments, antioxidants, UV. absorbers, optical brighteners, or careful selection of the nano?ller it is possible to vary the 40 any other additives generally employed in plastics formula penetration of the matrix polymer into the platelet structure of tion or the preparation of golf balls. the nano?ller on mixing. Thus, the degree of interaction and intrusion of the polymer matrix into the nano?ller controls the Another particularly Well-suited additive for use in the compositions of the present invention includes compounds separation and dispersion of the individual platelets of the having the general formula: nano?ller Within the polymer matrix. This interaction of the 45 polymer matrix and the platelet structure of the nano?ller is de?ned herein as the nano?ller “reacting into the structure of the polymer” and the subsequent dispersion of the platelets Where R is hydrogen, or a C l-C2O aliphatic, cycloaliphatic or Within the polymer matrix is de?ned herein as the nano?ller aromatic systems; R' is a bridging group comprising one or “being substantially evenly dispersed” Within the structure of 50 more C l-C2O straight chain or branched aliphatic or alicyclic the polymer matrix. groups, or substituted straight chain or branched aliphatic or If no compatibiliZer is present on the surface of a ?ller such alicyclic groups, or aromatic group, or an oligomer of up to 12 as a clay, or if the coating of the clay is attempted after its repeating units including, but not limited to, polypeptides addition to the polymer matrix, then the penetration of the derived from an amino acid sequence of up to 12 amino acids; matrix polymer into the nano?ller is much less e?icient, very 55 and X is C or S or P With the proviso that When X:C, n:1 and little separation and no dispersion of the individual clay plate y:1 and When X:S, n:2 and y:1, and When X:P, n:2 and lets occurs Within the matrix polymer. y:2. Also, m:1-3. These materials are more fully described in Physical properties of the polymer Will change With the copending U.S. Provisional Patent Application No. 60/588, addition of nano?ller. The physical properties of the polymer 603, ?led on Jul. 16, 2004, the entire contents of Which are are expected to improve even more as the nano?ller is dis 60 incorporated herein by reference. These materials include, persed into the polymer matrix to form a nanocomposite. Without limitation, caprolactam, oenantholactam, decanolac Materials incorporating nano?ller materials can provide tam, undecanolactam, dodecanolactam, caproic 6-amino these property improvements at much loWer densities than acid, 11-aminoundecanoicacid, 12-aminododecanoic acid, those incorporating conventional ?llers. For example, a diamine hexamethylene salts of adipic acid, aZeleic acid, nylon-6 nanocomposite material manufactured by RTP Cor 65 sebacic acid and 1,12-dodecanoic acid and the diamine non poration of Wichita, Kans., uses a 3% to 5% clay loading and amethylene salt of adipic acid, 2-aminocinnamic acid, L-as has a tensile strength of 11,800 psi and a speci?c gravity of partic acid, 5-aminosalicylic acid, aminobutyric acid; ami US 7,874,940 B2 29 30 nocaproic acid; aminocapyryic acid; l-(aminocarbonyl)-l forces the molten polymeric material or polymeric precursor cyclopropanecarboxylic acid; aminocephalosporanic acid; material through an adapter and into and out of a small open aminobenZoic acid; aminochlorobenZoic acid; 2-(3 -amino-4 ing, called a die, having a desired selectable shape and siZe. chlorobenZoyl)benZoic acid; aminonaphtoic acid; aminoni The shape may be that substantially corresponding to a ?n cotinic acid; aminonorbomanecarboxylic acid; aminoorotic ished ball component, such as substantially spherical, or in a acid; aminopenicillanic acid; aminopentenoic acid; (ami some other predetermined shape suitable for a doWnstream nophenyl)butyric acid; aminophenyl propionic acid; ami process, such as, for example, shaped to conform to a mold nophthalic acid; aminofolic acid; aminopyraZine carboxylic used in a subsequent compression molding step. acid; aminopyraZole carboxylic acid; aminosalicylic acid; One bene?t of the presently disclosed extrusion process is aminoterephthalic acid; aminovaleric acid; ammonium that it can be a substantially continuous process that avoids hydrogencitrate; anthranillic acid; aminobenZophenone car having to reuse or form molds, such as With injection molding boxylic acid; aminosuccinamic acid, epsilon-caprolactam; processes. Thus, extruded material may be fed continuously omega-caprolactam, (carbamoylphenoxy)acetic acid, onto a conveyor belt. sodium salt; carbobenZyloxy aspartic acid; carbobenZyl glutamine; carbobenZyloxyglycine; 2-aminoethyl hydrogen Extruded polymeric material may be alloWed to cool sulfate; aminonaphthalenesulfonic acid; aminotoluene sul before further processing, if any is desired or necessary. Cool fonic acid; 4,4'-methylene-bis-(cyclohexylamine)carbamate ing may result simply from radiant heat transfer, or the extru sion system may include a cooling area, such as a chamber and ammonium carbamate. Most preferably the material is selected from the group that includes bloWers or a ?uid immersion chamber, such as a Water immersion chamber. Alternatively, in a continuous, consisting of 4,4'-methylene-bis-(cyclohexylamine)carbam 20 multi-step process, the extruded material may be directly ate (commercially available from RT. Vanderbilt Co., Nor transferred to a subsequent processing step or device. Walk Conn. under the tradename Diak® 4), ll-aminounde canoicacid, l2-aminododecanoic acid, epsilon-caprolactam; There are many different types of extruders available, such omega-caprolactam, and any and all combinations thereof. as ram extruders, continuous-?ow ram extruders, gear-pump In an especially preferred embodiment a nano?ller additive 25 extruders, single screW extruders, tWin screW extruders, mul component in the golf ball of the present invention is surface tiple-screW extruders, either With hot-feed or cold-feed. Any modi?ed With a compatibiliZing agent comprising the earlier of these general types of extruders may be used to extrude golf described compounds having the general formula: ball components, such as cores. Moreover, depending upon the needs and process design, any of these general types of extruders may be combined to form a system to make the 30 product. A most preferred embodiment Would be a ?ller comprising a Generally extruders include a main feeder, a side feeder, a nano?ller clay material surface modi?ed With an amono acid including l2-aminododecanoic acid. Such ?llers are avail liquid injector, a motor drive, a gear-pump, a barrel, a vent, a able from Nanonocor Co. under the tradename Nanomer vacuum, a screW, a breaker plate, die, etc. A tWin-screW extruder may have non-intermeshing screWs, intermeshing 1.24TL. 35 co-rotating screWs, or intermeshing counter-rotating screWs. Golf ball components may, in addition to the materials ScreWs may be solid or cored. ScreWs also can be one piece or speci?cally described herein, include other materials, such as composed of multiple screW elements to form screW Zone(s). UV stabiliZers, photostabiliZers, photoinitiators, co-initia ScreWs can have different sections, such as feed, compression tors, antioxidants, colorants, dispersants, mold release 40 or transition, mixing, and metering sections, or any combina agents, processing aids, inorganic ?llers, organic ?llers, and tion of these. ScreWs can accommodate extruder designs that combinations of such materials. use venting, degassing, or vacuum Zones to remove entrapped V. Method for Making Disclosed Embodiments air, volatile constituents, etc. from the melt before it is extruded through the die. ScreWs are characterized by their 45 L/D ratio, Which typically range from about 16:1 to about A. Extrusion Generally 40:1. Extrusion is a process by Which a material is forced to How in a more or less continuous manner through a die to produce B. Pro?le Extrusion for Golf Ball Core a desired shape and cross section for the product extruded, 1. Material referred to herein as an extrudate or preform. Material to be 50 To applicants’ knoWledge, golf ball cores have not been extruded, such as the polymeric materials, or polymeric pre made by extrusion processes With thermoplastics. Thus, one cursor materials, such as monomeric materials, described aspect of the disclosed method comprises extruding golf ball herein for forming golf ball components, are ?rst loaded into cores, or core performs that may require additional process a hopper or a material storage unit. The material, or combi ing, comprising polymeric materials, or polymeric precursor nations of materials, to be extruded may be provided in vari 55 materials, suitable for making golf ball cores, including With ous physical forms, such as pellets, poWder, liquid, strand, out limitation the materials disclosed herein. Typically, but strip, paste, and combinations thereof. not necessarily, the core composition comprises at least one Desired materials are fed into a feed chamber and the thermoplastic resin. Multiple different polymeric composi material moved through the feed chamber by actuating a tions also can be used to make suitable ball cores. Moreover, screW drive. The feed chamber may be, and typically is, a 60 the core composition optionally may further comprise ?bers heated chamber. Polymeric material, or polymeric precursor and/or ?llers useful for making golf ball cores that are noW material, such as monomers or polymers that may be knoWn or hereafter developed, such as the materials described crosslinked after the extrusion process, initially generally at herein, With core compositions often including speci?c grav substantially ambient temperature, typically changes into a ity adjusting ?ller(s), organic, inorganic, or metallic ?ller(s), molten stream by compression forces applied by the screW, 65 nano-?ller(s), nano-?bers, processing aids, anti-oxidants, heat applied by a heater, including external heater(s) in the cross-linking agents, co-cross-linking agents, peptiZers, barrel, and viscous ?oW friction. The increased pressure accelerators, UV stabiliZers, photostabiliZers, photoinitia US 7,874,940 B2 31 32 tors, co-initiators, antioxidants, colorants, dispersants, mold by the number of cavities available for injection molding. release agents, processing aids, colorants, etc., and combina lnj ection molding requires making separate, expensive mold tions of such materials. ing cavities, as Well as the attendant sprues and runners. And, 2. Extrusion simply by changing the die, the shape and/ or dimensions of Golf ball compositions, particularly thermoplastic golf ball the extruded pre-form can be controlled, Whereas injection compositions, are fed into the extruder. The extrudate molding requires redesigning and producing the injection extruded through the die has a pre-determined shape. The molds. It also is possible to make different cores or core extrudate cross-section can be any desired shape, including preforms having different siZe or speci?c gravity even With Without limitation, circle, oval, triangle, rectangle, square, the same extrudate. pentagons, hexagone, octagone, or any polygonal shape. The extrusion process also alloWs removal of entrapped air Cubic or spherical extrudes may be best accommodated by or volatiles that may be evolved or entrapped during the post extrusion processing, such as compression molds. The extrusion process, such as by the application of a vacuum. extrudate has any suitable length, such as may be suf?cient to This substantially reduces, or eliminates, voids in the core, make a single embodiment of particular golf ball compo pre-form, or pro?le. As described in the Background, micro nents, such as a core, or to make multiple components, such as voids often occur in compression or injection molded mate multiple cores When cut, such as a pro?le, or pro?le With rials, Which directly relates to the durability and/or perfor predetermined, 3-dimensional shapes either interconnected mance of the core or golf ball. or disconnected form. D. Additional Processing FolloWing Extrusion During the extrusion process, the polymeric material and 20 The ability to extrusion process compositions according to other ingredients are fed into the extruder by main feeder(s), the present invention provides considerable ?exibility for side-feeder(s), liquid-injector(s), another extruder(s), or manufacturing individual golf ball components and ?nal combinations of these materials. Multiple extrusions, as balls. For instance, the core may be formed by ?rst extrusion needed or desired, can be performed to make the core com molding desired polymeric formulations, folloWed by a sub position before making the core or core preform. 25 sequent compression-molding step With or Without initiating During the extrusion process, the polymeric material may a crosslinking reaction of the core composition. The molding be degassed under atmospheric pressure or a vacuum. and/or cure conditions in this compression step Would depend Optionally, any foreign materials or impurities are ?ltered by on the formulation of the polymeric composition selected. the screen pack in a breaker plate, Which is located betWeen Finished golf balls may be prepared by initially forming a the barrel and the die. 30 core or a core pre-form in an extrusion process With or With In certain embodiments, the extrudate is cooled and/or cut out combination of any post core-forming process, folloWed as needed after it exits the die, to be transferred to subsequent by forming the intermediate or cover layer sequentially over processing steps, such as cutting, compression molding, etc. the core by various methods such as cold-runner injection Subsequent processing steps can be used to form a golf ball molding, hot-runner injection molding, compression mold component, such as a core, including compression in a com 35 ing, reaction injection molding, casting, coating, or combi pression molding machine to make a core. During the com nation thereof, to produce layers of the required thickness and pression molding step, additional chemical processing of the ultimately golf balls of the required diameter. A variety of extrudate may occur, such as crosslinking of the polymeric conventional mold designs can be used to form an interme material. Any other post-cure process noW employed to make diate and/or cover layer(s), such as injection mold With a golf balls, or hereafter developed for the same purpose, can be 40 various con?gurations of cavities, runner(s), gate(s), retract applied to golf ball components processed as described able pin(s), ?xed pin(s), mold cavities With a various surface herein, particularly post extrusion processing that is desirable modi?cation or treatment, mold cavities With various types of for forming golf ball cores, including Without limitation, post protrusions, mold and mold cavities With various types of curing processing that includes applying thermal energy, irra material(s), or any combinations of those. If any further diation, or both. Moreover, to form multiple layer golf balls, 45 chemical modi?cation or reaction is necessary, using a heated any process for forming intermediate layers and outer cover injection mold, heated compression mold, or irradiation layers noW knoWn or hereafter developed can be used to make alloWs the temperature to be controlled suf?ciently to either ?nal balls having multiple layers. partially or fully crosslink the material to yield the desired C. Extrusion Processing Bene?ts layer properties. If the material is partially cured, additional Extrusion processing according to the disclosed embodi 50 compression molding or irradiation steps optionally may be ments of the present invention provides signi?cant bene?ts employed to complete the curing process to yield the desired relative to conventional golf ball processing. For example, layer properties. since the resin is thermoplastic, extruded thermoplastic cores Alternatively, intermediate and/or cover layers may be are easier to handle, the thermoplastic composition can be formed around the extruded core and/ or intermediate layer(s) modi?ed, blended, and/ or recycled compared to conventional 55 folloWed by a compression molding the half shells about the processes that are used to form rubber cores. Any pre-form core and/or intermediate layer(s) to effect the curing of the made from the thermoplastic can be stored for subsequent layers in the ?nal ball. processing, unlike thermoset materials. Compression mold Outer or intermediate covers also may be formed around ing may not be necessary, if the core is formed during the the cores With or Without a fuirther crosslinking reaction by extrusion process, right after the die, and it may not be nec 60 cold-runner injection molding, hot-runner injection molding, essary to cure the extruded polymeric material. co-injection molding, reaction injection molding, compres Disclosed embodiments of the extrusion process also pro sion molding, transfer molding, liquid coating, poWder coat vide advantages relative to injection molding process. The ing, liquid dipping, dipping ?uidized bath, casting, or any present extrusion process is amenable to continuous process combination thereof. ing, as it avoids, for example, the use of the mold systems 65 In addition, if radiation is used to cross-link, then the mix required for injection molding, and hence a large number of ture comprising the crosslinkable polymer and any other components can be made. lnj ection molding output is limited additives can be irradiated folloWing mixing, during forming