US008883917B1

(12) United States Patent (10) Patent No.: US 8,883,917 B1 Davies et al. (45) Date of Patent: Nov. 11, 2014

(54) POLYMERS HAVING ALOW Yang et al., “Preparation of 6/silica nanocomposites from COEFFICIENT OF FRCTION AND METHOD silica Surface intitiated ring-opening anionic polymerization'. FOR THE MANUFACTURE THEREOF eXPRESS Polymer Letters vol. 1, No. 7 (2007) 433-442. Janicek, “Polymer/Silica Nanocomposite System”. Bachelor Thesis, (75) Inventors: Jack D. Davies, Houma, LA (US); 2007, Tomas Bata University including technical information in Gregory J. Biederman, Manchester, NH Appedix 3 regarding Aerosil 200, R972, and R9200 (Degussa), data (US); Christopher A. Coco, Salem, NH from Sigma-Aldrich regarding Aerosil and Cab-O-Sil, Cab-O-Sil (US) LM-150, M-5, EH-5, TS-610, TS-530 (Cabot), and HDK Pyrogenic Silica (Wacker Silicones); total 108 pages. (73) Assignee: Nylon Corporation of America, Inc., Khan et al., “Rheology of Fumed Silica Dispersion for Fiber-Optic Manchester, NH (US) Cables'. Polymer Engineering and Science, Dec. 1991, vol. 31, No. 24; pp. 1701-1707. (*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 * cited by examiner U.S.C. 154(b) by 219 days. (21) Appl. No.: 13/608,168 Primary Examiner — Edward Cain (74) Attorney, Agent, or Firm — Renner Kenner Greive (22) Filed: Sep. 10, 2012 Bobak Taylor & Weber (51) Int. Cl. COSL 77/00 (2006.01) (57) ABSTRACT (52) U.S. Cl. USPC ...... 524/845; 524/492 A method for the preparation of a polyamide-based compo (58) Field of Classification Search sition provides for the substantially uniform dispersion of CPC ...... C08L 77/00; C08L 77/02; C08L 77/06 particulate silica and, optionally, mineral oil and any other USPC ...... 524/845, 492 lubricant additive, within a polyamide matrix. The method See application file for complete search history. includes mixing particulate silica, and optionally, mineral oil and other lubricant additives, to one or more polyamide (56) References Cited producing monomers, and water, to form an emulsion or U.S. PATENT DOCUMENTS Suspension wherein the particulate silica (and mineral oil and other lubricant additives, when added) are substantially uni 7488,533 B2 2/2009 Nishi et al. 7,749,024 B2 7, 2010 Chambers et al. formly dispersed therein, and then in situ polymerizing the 8,043,119 B2 10/2011 Kummer et al. monomer(s) to provide a polyamide matrix wherein the par 2012fO234206 A1* 9, 2012 Greenwood et al...... 106,287.26 ticulate silica, and optional mineral oil and other optional lubricant additives, remain substantially uniformly dispersed FOREIGN PATENT DOCUMENTS in the resulting polyamide matrix to form the polyamide EP 1651 566 B1 12/2011 based composition. A polyamide-based composition com WO WO/97,38043 A1 10, 1997 prising a polyamide matrix having silica and optionally, min OTHER PUBLICATIONS eral oil and other lubricant additives, substantially uniformly dispersed within the polyamide matrix is also provided. Technical Data for "Sylysia FCP, Fuji Silysia Chemical Ltd., undated, available on internet at: http://www.tcrindustries.com/Prin cipals/BROCHURES/fujibrochures/FCP%20Brochure.pdf. 54 Claims, 3 Drawing Sheets U.S. Patent Nov. 11, 2014 Sheet 1 of 3 US 8,883,917 B1

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99 U.S. Patent Nov. 11, 2014 Sheet 2 of 3 US 8,883,917 B1

VZ(61-) GZ-61-I

U.S. Patent Nov. 11, 2014 Sheet 3 of 3 US 8,883,917 B1

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S US 8,883,917 B1 1. 2 NYLON POLYMERS HAVING ALOW coefficient of friction so as to allow the installer to more easily COEFFICIENT OF FRCTION AND METHOD pull the wire through the spaces and openings without too FOR THE MANUFACTURE THEREOF large of a pulling force that would cause degradation or dam age to the wire or cable. TECHNICAL FIELD To overcome this problem, the general industry practice has been to coat the exterior surface of the cable sheath or The present invention relates to a nylon polymer having a jacket with a pulling lubricant at the job site in order to reduce low coefficient of friction. More particularly, the present the coefficient offriction between this surface and the conduit invention relates to a method of preparing a polyamide-based walls or like Surfaces, typically using Vaselines or lubricants composition (e.g., a nylon polymer) having silica and, option 10 produced specifically, and well known in the industry, for ally, mineral oil and other lubricant additives, substantially uniformly dispersed into a polyamide matrix so as to provide such purpose, such as Yellow 77(R). As used herein, the term a polyamide-based composition that, when extruded, com “pulling lubricant' is defined to mean a lubricating material pounded, casted, molded, or otherwise formed into a product, added after polymerization of the nylon polymer, and typi provides the surface of that product with a low coefficient of 15 cally during extrusion or formation of the product, or coated friction. The invention is particularly suitable for use in prod onto the finished product, which reduces the coefficient of ucts where low surface coefficient of frictions are desired, friction of the exterior surface of the sheath or jacket of the such as low friction cables or "slick” sheaths for THFHN cable to facilitate the pulling of the cable. cables commonly used in building wire. The aforementioned industry practice of applying a pulling lubricant to the finished cable at the work site poses problems, BACKGROUND principally due to the additional time, expense and manpower required to lubricate the finished cable surface at the job site Building wire is widely used to carry electrical current to as well as to clean up after the lubricating process is com all external uses of power in industrial, residential and com pleted. Thus, the need exists to provide a cable or wire, or at mercial buildings. THHN (Thermoplastic High Heat-resis 25 least an exterior sheath or jacket for a cable or wire that does tant Nylon coated) building wire is one type of wire or cable not require the application of pulling lubricants at the work commonly used for this purpose. Typically, THHN building site. wire comes in Stranded or Solid conductors depending on the Alternative solutions have been tried but have been gener size. For example, Solid conductors may include copper or ally unsuccessful, including the extrusion of a lubricant layer aluminum, which are then covered in PVC (polyvinyl chlo 30 over the extruded polymeric sheath during the manufacturing ride) insulation with a nylon jacket or sheath. THEIN building of the cable, or the application of granules of material to the wire may also be used for wiring of machine tools, control still-hot sheath during the extrusion process, which granules circuits or on certain appliances. Commonly known cables are designed to become detached when the cable is pulled used in building wire include, but not limited to Types THFHN, through the duct. These solutions not only require major THWN, THWN-2 type wires, 14-4/0 AWG, and 250-2000 35 alterations of the manufacturing line, but also result in a loss kcmil sizes. in manufacturing time, increased economic costs, and unde The prior art discloses that electrical cables such as THFHN sirable fluctuations in the geometrical dimensions of the cable building wire generally include a conductor core and also an sheaths or jackets. outer jacket or sheath. The term “sheath’ is defined to mean At least one patent in the prior art has distinguished the outermost protective jacket or covering Surrounding a 40 between what are referred to as “pulling lubricants’ and what conductor core, whether of a single type material or multiple are “processing lubricants.” A pulling lubricant is a lubricant layers of the same or different material. The conductor core that is applied to the nylon polymer product and appears at the may typically be, for example, a single metal wire, multiple outside surface of the sheath or jacket of the cable and is small wires twisted together to make a “stranded' cable, or effective in lowering the surface coefficient of friction so as to multiple insulated wires or other type electrical conductors 45 reduce the force necessary to pull the cable along or through acting together to serve a particular function (e.g., three building Surfaces or enclosures. A processing lubricant is phase connection). The sheath may comprise one or more lubricating material is a lubricant that is applied to the nylon layers of polymeric or other material to provide physical, polymer composition to facilitate the cable or wire manufac mechanical, electrical insulating and/or chemical protection turing process. Such as the flow of polymer chains during any for the underlying cable components. The exterior portion of 50 polymer compounding as well as during the extrusion pro the sheath may be made of a polyamide composition, also cesses while the polymer is in its molten or melt phase. Cable often referred to as nylon. For example, a THHN building manufacturers have long used processing lubricants, such as wire may comprise a conductor core of a single Solid or Stearic acid or ethylene bis-Stearamide wax, as a minor com Stranded conductor, Surrounded by a layer of polyvinyl chlo ponent of the polymeric compound from which the cable ride (PVC) electrical insulation, covered by an outer layer of 55 sheath or jacket is formed. Because a processing lubricant is nylon. normally not effective except when the polymer is in this melt Installation of electrical cable often requires that it be phase, the effect of a processing lubricant is essentially non pulled through tight spaces or Small openings in, and in existent in the final hardened polymer sheath of the cable. engagement with, narrow conduits, raceways, cabletrays, or Under current technology, even where there may be an exces passageways in rafters or joists. This becomes problematic 60 sive amount of the processing lubricant, a separate pulling since the exterior surface of the cable sheath normally has a lubricant would still be required to sufficiently reduce the high coefficient of friction, therefore requiring a large pulling cable sheaths or jackets exterior surface coefficient of fric force. Moreover, installation parameters include maximum tion in order to minimize the pulling force necessary to install allowable cable pulling tension and/or sidewall pressure lim the cable. In both definitions, however, the lubricants are its. Exceeding these limits can result in degradation of the 65 added to already polymerized nylon polymer compositions cable, physical damage and inferior installation. Thus, the either during a post-polymerization compounding process, need exists for a cable or wire that has a relatively low surface during production of the cables or wires, or after. US 8,883,917 B1 3 4 In light of the need for better lubricity of the cable or wire, often Stick to each other. Having a nylon composition with attempts have been made to provide building wire cables, and increased slipperiness helps to avoid this problem. particularly the nylon cable outer sheaths and jackets used in However, the use of greater amounts of silica or larger building wire, with more slickness, i.e., a lower coefficient of particle sizes of silica was found to be problematic in that the friction, Such that less externally applied pulling lubricants 5 greater amounts of silica or larger particles was shown to are required in order to minimize the pulling force necessary create aggregation (i.e., agglomeration of particles) and to install the building wire. In fact, it would be highly desir migration of the particles to the surface of the films. This was able if no externally applied pulling lubricants were neces noted to cause film breakage during processing and film aes sary to pull the building wire, thereby saving costs, the mess thetic defects, inasmuch as the films were required to be clear, created by using externally applied pulling lubricants, and 10 but aggregation and migration of silica is well known to cause operator strength for pulling the cable or wire. clarity issues in films. Further, it was found that larger par Accordingly, attempts have been made to produce a cable ticles of silica and/or high loadings of silica have a tendency or building wire with a sheath or jacket made of nylon mate to clog filters during processing, to increase the likelihood of rial into which a lubricating agent, Such as a silicone oil-based caking during processing, and to provide overall bad work or an erucamide-based lubricant, is introduced. By doing so, 15 ability for the nylon polymer composition, thus making the the lubricity of the polymerized nylon cable, or stated another addition of silica not attractive for other commercial pur way, the coefficient of friction of the nylon cable or wire is poses. Thus, only very small amounts and very small particles lowered. That is, the lower the coefficient of friction, the more of silica were shown to be suitable for use in the limited field lubricity and more slickness is provided to the cable or wire. of bi-axial oriented polyamide film. As used herein, a “lubricating agent' is a lubricant that is Nevertheless, if a nylon polymer composition could be added to a nylon polymer composition after polymerization made with particulate silica having much larger particle sizes of the polyamide-producing monomers into nylon or other (significantly larger than those used in the nylon composi , whether added before, during or after the forma tions for anti-blocking films), or alternatively, in Sufficient tion of product. Thus, by this definition, both pulling lubri loadings (significantly higher than those used in nylon com cants and processing lubricants, as well as any other lubri 25 positions for anti-blocking films) added in before the poly cants that are added to the nylon polymer composition in any merization process to provide inherent lubricity to the nylon post-polymerization process, are considered lubricating polymer composition itself. Such nylon polymer composi agents. tions would be highly desirable in any of a number of indus One well known method for adding lubricating agents, e.g., tries, including the slick cable and building wire industry. If silicone oil-based lubricants or erucamide-based lubricants, 30 the surface coefficient of friction of the nylon polymer com to the nylon material is accomplished by compounding the position after polymerization was lowered sufficiently lubricant with remelted nylon polymer pellets in a post-poly enough, no additional lubricating agents would be needed, merization extrusion process. Cables having outer sheaths or and even reducing the amount of lubricating agents needed jackets produced via this process have been found to have a would be beneficial to many industries. reduced surface coefficient of friction sufficient to lower the 35 Such desirable nylon polymer compositions could use required installation pulling force of the cable, such that the silica or other lubricant additives to obtain lubricity and not need for externally applied pulling lubricants can be greatly require lubricating agents, such as silicone oil, in them. As the reduced or even eliminated. Unfortunately, it has been found terms are used herein, there is a distinction to be made that, in order to be effective in lowering the coefficient of between “lubricating agents’ and “lubricant additives.” As friction and to sufficiently increase the slickness of the cable 40 used herein and as defined above, lubricating agents include (and more particularly, its sheaths) via this method, high both pulling lubricants and processing lubricants, as well as loadings of at least 9% by weight of lubricating agents are any other lubricants that are added to the nylon polymer required. While improving surface lubricity, such higher composition whether added before or after the formation of loadings of lubricating agents can compromise cable process the product, but after the polymerization process for produc ing efficiency, can reduce protective sheath mechanical prop 45 ing the nylon polymer compositions have occurred. In con erties and can reduce flame retardancy, all of which compro trast, lubricant additives are defined as lubricants that are mise the desired characteristics of the cable sheath. specifically mixed with at least one polymer-producing Thus, the need exists for improved nylon compositions monomer and water prior to polymerization, such that the having a low Surface coefficient of friction, and particularly, resultant polymer, here, polyamide (nylon) polymer, contains compositions having a polyamide matrix Suitable for use in 50 the lubricant additive in situ, within the nylon polymer com building wire as slick cables or cable sheaths that do not position upon polymerization. Such polymers are made pref require high levels of lubricating agents to be added during erably with particulate silica well-dispersed (i.e., homoge any post-polymerization process. Heretofore, no one has suc neous) within the polymer backbone. Such polymers provide cessfully produced a nylon polymer composition that has the advantage of being Suitable for the production and manu achieved this need for the slick cable and building wire indus 55 facture of slick cables or cable sheaths orjackets for building try. wire. The silica may be either chemically or mechanically Silicon dioxide, commonly known as silica, is an inorganic bound within the polyamide matrix. material derived from quartz and other rock like minerals. In In addition to the incorporation of silica, it is believed that one instance, namely, in the production of bi-axial oriented the incorporation of lubricant additives such as mineral oil polyamide film compositions for the film packaging industry, 60 would also be desirable. However, heretofore, the introduc it has been found that the intimate dispersion of very low tion, let alone the substantially uniform dispersion, of lubri amounts (i.e., 2.0 wt.% or less) of silica having a particular cant additives into a polyamide matrix prior to polymeriza particle diameter (of 0.5 to 5um) during the preparation of a tion has never been successful due to the “oil like' nature of polyamide film can provide a nylon polymer composition the lubricant additives. Introduction of lubricating agents in a having excellent slipperiness. For film producers, the advan 65 Subsequent, post-polymerization extrusion/compounding tage of polymer film containing particulate silica is to avoid process has been well documented, but high levels of lubri film blocking, where adjacent (on top of each other) layers cating agents are required due to the lubrication method and US 8,883,917 B1 5 6 the lack of synergy achieved between the lubricating agents In some embodiments, the resultant polyamide-based and the polyamide matrix. Moreover, the introduction of composition may include some residual polyamide-produc silica in the post-polymerization process does not create Suf ing monomer. Where this is the case, the method of the ficient synergy or lower the surface coefficient of friction present invention may further comprise, after polymerization, Sufficiently enough to allow even a significant reduction in the 5 extracting the residual polyamide-producing monomer from amounts of the lubricating agents used. the polyamide-based composition to a level of less than 8wt. Thus, the need continues to exist for a process by which a %. In other embodiments, the residual polyamide-producing lubricant additive. Such as mineral oil, can be added to a nylon monomer may be extracted from the polyamide-based com polymer composition. Such a process will necessarily need to position to a level of less than 5 wt.%. In still other embodi be able to substantially uniformly disperse the lubricant addi 10 ments, the residual polyamide-producing monomer may be tive, as well as any other component, e.g., silica, throughout extracted from the polyamide-based composition to a level of the polymer matrix in order to achieve the desired surface less than 3 wt.%. And in still other embodiments, the residual lubricity necessary for satisfactory use as the sheath or jacket polyamide-producing monomer may be extracted from the of a wire or cable. Such a process would satisfy a long felt polyamide-based composition to a level of less than 2 wt.%. need for cost effective manufacturing of polyamides Suitable, 15 In some embodiments, it may be necessary to dry the for example, in the forming of slick cables and other appli polyamide-based composition to remove moisture. Where cations. However, currently, the best alternative is to add high this is the case, the method of the present invention may loadings of lubricating agents during the production of the further include, after polymerization, drying the polyamide cable or wire sheaths orjackets, a well known post-polymer based composition to a moisture level of 1.8% by weight or ization process. less. In other embodiments, the polyamide-based composi tion may be dried to a moisture level of less than 1.5%. In still SUMMARY OF THE INVENTION other embodiments, the polyamide-based composition may be dried to a moisture level of less than 1%. One aspect of the present invention may be achieved by a In some embodiments, the method may further include method for the preparation of a polyamide-based composi 25 pelletizing the polyamide-based composition. It will be tion, wherein particulate silica is Substantially uniformly dis appreciated that the polyamide-based composition can be persed within a polyamide matrix that forms the polyamide formed into various products via post-polymerization pro based composition. By the term “substantially uniformly cesses withoutpelletizing. However, by pelletizing the polya dispersed, it is meant that the silica (or other components mide-based composition, the composition will be easier to later identified. Such as mineral oil) is Substantially homog 30 package and ship to various destinations where it can be enously disbursed throughout the polyamide matrix and is not further post-polymerization processed and formed into vari substantially aggregated or clumped together in a manner that ous products. allows for the resultant polyamide-based composition to have The polyamide-based composition can be formed into any an inherent lubricity. “Inherent lubricity' is defined as a suf desired product by any of a number of different methods. For ficient lubricity contained within the polyamide-based com 35 example, in some embodiments either the same or different position Such that a lower amount of or no Subsequent lubri from the above embodiments, the product is formed by cating agent is required to be added in order to achieve the extruding the polyamide-based composition into an extruded desired property of a low surface coefficient or friction for the product. In other embodiments the same or different from product ultimately formed by the polyamide-based composi above embodiments, the product is formed by compounding tion. In the case of cable or building wire production, this 40 the polyamide-based composition into a compounded prod would mean no or significantly less pulling lubricant is uct. In still other embodiments the same or different from required to be added in a post-polymerization process by a above embodiments, the product is formed by casting the secondary extrusion compounder, by the cable producer, or at polyamide-based composition into a casted product. In yet the job site by the end user. other embodiments the same or different from above embodi In one embodiment, the method for preparation of a polya 45 ments, the product is formed by molding the polyamide mide-based composition described above comprises first based composition into a molded product. And in still other mixing more than 2 weight percent particulate silica, at least embodiments the same or different from other embodiments, one polyamide-producing monomer, and water, to form a the product is formed by thermoforming the polyamide-based Suspension wherein the particulate silica is Substantially uni composition into a thermoformed product. Notably, in each formly dispersed therein, and then polymerizing the at least 50 of the formation of product embodiments above, all of the one polyamide-producing monomer with the particulate resultant products have a lower surface coefficient of friction silica Substantially uniformly dispersed in situ to provide a than a product substantially devoid of silica or where silica polyamide matrix wherein the particulate silica remains Sub was added to the polyamide matrix after polymerization. stantially uniformly dispersed in the resulting polyamide Moreover, it is during these formation steps where lubricating matrix to form the polyamide-based composition. In a more 55 agents, e.g., pulling lubricants, are commonly employed and particular embodiment, the step of mixing may be more par are specifically used in the cable and wire industry. Thus, a ticularly set forth by first mixing the at least one polyamide polyamide-based composition of the present invention can be producing monomer with water to form a reaction mixture formed into a sheath or jacket of a cable or wire. In more and then adding the particulate silica to the reaction mixture particular embodiments, the polyamide-based composition is to form a suspension before commencement of polymeriza 60 formed into an outside protective jacket in the production of tion. In one embodiment, the step of mixing the silica and thermoplastic-insulated wires or cables for building wire polyamide-producing monomer is performed without the applications. Again, the resultant products have inherent addition of any lubricant additives, while in other embodi lubricity to the extent that they have a sufficiently low coef ments, lubricant additives can be incorporated in to the Sus ficient of friction to not require the use of lubricating agents pension as later described. Thus, the present invention 65 or, more specifically, pulling lubricants. requires that the silica be added prior to polymerization of the In other or the same embodiments, the polyamide-based polyamide-producing monomer into a polyamide matrix. composition may be formed into monofilament, typically by US 8,883,917 B1 7 8 well known extrusion methods. In other or the same embodi In addition to incorporating silica, one or more embodi ments, the product may beformed into at least two twisted or ments of the present invention may include mixing at least braided strands. In other or the same embodiments, the prod one lubricant additive with the silica, the at least one polya uct may beformed into a single layer film. In other or the same mide-producing monomer, and the water to forman emulsion embodiments, the product may be formed into a multilayer prior to polymerization, wherein the particulate silica and the film having at least two layers. In other or the same embodi at least one lubricant additive is substantially uniformly dis ments, the product may be formed into a molded part, such as persed in the emulsion and then polymerizing the at least one by using known molding techniques. In other or the same polyamide-producing monomer with the particulate silica embodiments, the product may be formed into a formed part and the at least one lubricant additive substantially uniformly by methods well known in the art. In other or the same 10 dispersed in situ to provide a polyamide matrix wherein the embodiments, the product may be formed into a powder particulate silica and the at least one lubricant additive coating. And in other or the same embodiments, the product remains substantially uniformly dispersed in the resulting may be formed into a spray coating. polyamide matrix to form the polyamide-based composition. It will be appreciated that any known monomer suitable for Such lubricant additives may include silicone oil, fatty producing a polyamide when polymerized may be used in the 15 amides, metallic fatty acids, ester-based fatty acids, petro present invention. In some embodiments of the present inven leum jelly, petroleum-based oil, mineral oil, plant-based oils, tion, the at least one polyamide-producing monomer may be plasticizers, dibasic esters, silicones, anti-static amines, selected from caprolactam, 11-amino undecanoic acid, and organic amities, ethanolamides, mono- and di-glyceride fatty So as to produce , nylon 11 and nylon 12, amines, ethoxylated fatty amines, Zinc Stearate, Stearic acids, respectively. In other embodiments, the at least one polya palmitic acid, calcium Stearate, lead Stearate, Sulfates and Zinc mide-producing monomers includes at least two monomers Sulfates. In a more particular embodiment, the step of mixing wherein hexamethylenediamine (HMD) is reacted with an may be more particularly set forth by first mixing the at least acid selected from adipic acid (to produce nylon 6.6), azelaic one polyamide-producing monomer with water to form a acid (to produce nylon 6.9), sebacic acid (to produce nylon reaction mixture; then adding particulate silica to the reaction 6.10), and dodecanedioic acid (to produce nylon 6,12). In 25 mixture to form a suspension; and then adding the at least one other embodiments, the polyamide-producing monomers lubricant additive to the suspension before commencement of may be made into polyamide copolymers by the addition of polymerization to form an emulsion, Such that the silica aids caprolactam (or lauralactam, where nylon 12 is desired as one the distribution of the at least one lubricant additive substan of the blocks) with the hexamethylenediamine and one of the tially uniformly throughout the emulsion. The addition of the acid above. Such copolymers would include nylon 6/66 (with 30 at least one lubricant additive together with the silica, polya adipic acid), nylon 6/69 (with azelaic acid), nylon 6/610 (with mide-producing monomers and water results in a mixture/ sebacic acid) and nylon 6/612 (with dodecanedioic acid). In suspension/emulsion that when polymerized has increased still another embodiment, caprolactam may be copolymer Surface lubricity as compared to polymers containing similar ized with laurolactam to produce nylon 6/12. In the present or the same levels of silica or lubricant additives alone. While invention, any diamine can essentially be added with any 35 the exact mechanism of this synergy is still a matter of specu diacid to produce a polyamide matrix Suitable for the present lation, it is believed that the silica acts as a compatiblizing invention. Likewise, at least one polyamide-producing mono agent for hydrophobic lubricant additives and the more mer can be selected from any number of diamines (typically hydrophilic monomer/water mixture significantly improving at least one) and any number of diacids (typically at least two) the dispersion of the lubricant additives. Polyamides pro Sufficient to produce a polyamide copolymer. In one embodi 40 duced in this manner have been found to contain sufficient ment, the at least one polyamide-producing monomer is inherent lubricity such that they may be processed into low caprolactam. friction cables without the addition of any lubricating agents. In one or more embodiments herein of the present inven In one or more embodiments, from about 0.1 wt.% to about tion, the silica is amorphous. In other or the same embodi 12 wt.% of the at least one lubricant additive may be mixed. ments herein, the silica is micronized. In other or the same 45 In other embodiments, from about 1 wt.% to about 10 wt.% embodiments herein, more than 3 wt.% of silica is loaded or of the at least one lubricant additive may be mixed. In still mixed with the polyamide-producing monomer and water. In other embodiments, from about 3 wt.% to less than 9 wt.% other embodiments, from about 3 wt.% to about 12 wt.% of of the at least one lubricant additive may be mixed. silica is loaded. In other or the same embodiments herein, In another embodiment of the present invention, mineral from more than 3 wt.% to less than 9 wt.% of silica is loaded. 50 oil may be mixed with the silica, the at least one polyamide In other embodiments, more than 4 wt % to less than 8 wt.% producing monomer, and the water to form an emulsion prior of silica is mixed. In one embodiment, the silica is loaded at to polymerization, wherein the particulate silica and mineral 6 wt.%. In other or the same embodiments, the silica may be oil are substantially uniformly dispersed in the emulsion. The characterized by an average particle size of from about 1 at least one polyamide-producing monomer is then polymer micron to about 20 microns. In other or the same embodi 55 ized with the particulate silica and the mineral oil substan ments, the silica may be characterized by an average particle tially uniformly dispersed in situ to provide a polyamide size of from about 2 microns to about 12 microns. In other or matrix wherein the particulate silica and the mineral oil the same embodiments herein, the silica may be characterized remains substantially uniformly dispersed in the resulting by an average particle size from about 6 microns to about 11 polyamide matrix to form the polyamide-based composition. microns. In other or the same embodiments herein, the silica 60 In a more particular embodiment, the step of mixing the may be characterized by an average pore Volume of from mineral oil includes first mixing the at least one polyamide about 1.25 mL/g to about 1.6 mL/g. This pore volume of the producing monomer with water to form a reaction mixture; silica is believed to allow lubricant additives such as mineral then adding particulate silica to the reaction mixture to form oil to be incorporated into the in situ polymerization with the a suspension; and then adding mineral oil to the Suspension silica in some embodiments. In one or more of the embodi 65 before commencement of polymerization to form an emul ments herein, the method may be devoid of silicone-based or sion, such that the silica aids the distribution of the mineral oil erucamide-based pulling lubricants. Substantially uniformly throughout the emulsion. US 8,883,917 B1 10 In one or more embodiments, from about 1 wt.% to about remain Substantially uniformly dispersed in the resulting 12 wt.% of mineral oil may be mixed. In other embodiments, polyamide matrix to form the polyamide-based composition. from about 3 wt.% to about 10 wt.% of mineral oil may be In a more particular embodiment, the step of mixing includes mixed. Instill other embodiments, from about more than 3 wt. first mixing the at least one polyamide-producing monomer % to less than 9 wt.% of the mineral oil may be mixed may be with water to form a reaction mixture; then adding particulate mixed. In another embodiment, about 5 wt % mineral oil is silica to the reaction mixture to form a Suspension; and then mixed. Furthermore, where mineral oil is the only lubricant adding mineral oil to the Suspension to form an emulsion additive used with silica, the ratio of silica to mineral oil is before commencement of polymerization. from about 100:1 to about 1:1.5. In other embodiments, the In some embodiments of the invention described above, the ration of silica to mineral oil is from about 1.5:1 to about 10 resultant polyamide-based composition may include some 1:1.5. In another embodiment the ratio of silica to mineral oil residual polyamide-producing monomer. Where this is the is about 6:5. case, the method of the present invention may further com In some embodiments where mineral oil is mixed with the prise, after polymerization, extracting the residual polya silica, the at least one polyamide-producing monomer, and mide-producing monomer from the polyamide-based com water, the step of mixing may further include mixing at least 15 position to a level of less than 8 wt.%. In other embodiments, one other lubricant additive other than mineral oil with the the residual polyamide-producing monomer may be silica, mineral oil, the at least one polyamide-producing extracted from the polyamide-based composition to a level of monomer, and the water to form an emulsion prior to poly less than 5 wt.%. In still other embodiments, the residual merization, wherein the particulate silica, mineral oil and at polyamide-producing monomer may be extracted from the least one other lubricant additive are substantially uniformly polyamide-based composition to a level of less than 3 wt.%. dispersed in the emulsion. Such other lubricant additives may And in still other embodiments, the residual polyamide-pro be selected from the group consisting of silicone oil, ester ducing monomer may be extracted from the polyamide-based based fatty acids, petroleum jelly, petroleum-based oil, plant composition to a level of less than 2 wt.%. based oils, plasticizers, dibasic esters, silicones, anti-static In some embodiments of the above invention, it may be amines, organic amities, ethanolamides, mono- and di-glyc 25 necessary to dry the polyamide-based composition to remove eride fatty amines, ethoxylated fatty amines, Zinc Stearate, moisture. Where this is the case, the method of the present Stearic acids, palmitic acid, calcium Stearate, lead Stearate, invention may further include, after polymerization, drying Sulfates and Zinc sulfates. The step of polymerizing may the polyamide-based composition to a moisture level of 1.8% include polymerizing the at least one polyamide-producing by weight or less. In other embodiments, the polyamide monomer with the particulate silica, the mineral oil, and theat 30 based composition may be dried to a moisture level of less least one other lubricant additive all substantially uniformly than 1.5%. In still other embodiments, the polyamide-based dispersed in situ to provide a polyamide matrix wherein the composition may be dried to a moisture level of less than 1%. particulate silica, the mineral oil and the at least one other In some embodiments of the above invention, the method lubricant additive remains substantially uniformly dispersed may further include pelletizing the polyamide-based compo in the resulting polyamide matrix to form the polyamide 35 sition. It will be appreciated that the polyamide-based com based composition. position can be formed into various products via post-poly In one or more embodiments, from about 0.01 wt.% to merization processes without pelletizing. However, by about 12 wt.% of the at least one other lubricant additive may pelletizing the polyamide-based composition, the composi be mixed. In other embodiments, from about 0.1 wt.% to tion will be easier to package and ship to various destinations about 10 wt.% of the at least one other lubricant additive may 40 where it can be further post-polymerization processed and be mixed. In still other embodiments, from about 1 wt.% to formed into various products. less than 9 wt.% of the at least one other lubricant additive The polyamide-based composition made from in situ poly may be mixed. In another embodiment, about 3 wt.% of the merization of at least silica and mineral oil with at least one at least one other lubricant additive may be mixed. Where polyamide-producing monomer and water can beformed into anotherlubricant additive other than mineral oil is mixed with 45 any desired product by any of a number of different methods. silica and mineral oil, the ratio of silica to mineral oil and at For example, in some embodiments either the same or differ least one other lubricant additive combined is from about ent from the above embodiments, the product is formed by 1:1.5 to about 100:1. That is, the total combined amount of all extruding the polyamide-based composition into an extruded lubricant additives including mineral oil and any other lubri product. In other embodiments the same or different from cant additive should not be more than 1.5 times the amount of 50 above embodiments, the product is formed by compounding silica used. More preferably, the amount of the combined the polyamide-based composition into a compounded prod amounts of lubricant additives, including mineral oil and uct. In still other embodiments the same or different from other lubricant additives, should not be greater than the above embodiments, the product is formed by casting the amount of silica used. polyamide-based composition into a casted product. In yet Another aspect of the present invention may beachieved by 55 other embodiments the same or different from above embodi a method for the preparation of a polyamide-based composi ments, the product is formed by molding the polyamide tion, wherein particulate silica and mineral oil are Substan based composition into a molded product. And in still other tially uniformly dispersed within a polyamide matrix that embodiments the same or different from other embodiments, forms the polyamide-based composition. In one embodi the product is formed by thermoforming the polyamide-based ment, the method includes first mixing particulate silica, min 60 composition into a thermoformed product. Notably, in each eral oil, at least one polyamide-producing monomer, and of the formation of product embodiments above, all of the water, to form a Suspension/emulsion wherein the particulate resultant products have a lower surface coefficient of friction silica and mineral oil are Substantially uniformly dispersed than a product substantially devoid of silica and mineral oil or therein and then polymerizing the at least one polyamide where silica or mineral oil was added to the polyamide matrix producing monomer with the particulate silica and mineral oil 65 after polymerization. Thus, a polyamide-based composition Substantially uniformly dispersed in situ to provide a polya of the present invention can be formed into a sheath or jacket mide matrix wherein the particulate silica and mineral oil of a cable or wire. In more particular embodiments, the polya US 8,883,917 B1 11 12 mide-based composition is formed into an outside protective microns. In other or the same embodiments, the silica may be jacket in the production of thermoplastic-insulated wires or characterized by an average particle size of from about 6 cables for building wire applications. The resultant products microns to about 10 microns. In other or the same embodi have inherent lubricity to the extent that they have a suffi ments herein, the silica may be characterized by an average ciently low coefficient of friction to not require the use of 5 pore volume of from about 1.25 mL/g to about 1.6 mL/g. lubricating agents or, more specifically, pulling lubricants. Without being bound by theory, the pore volume of the silica In other or the same embodiments, the polyamide-based is believed to allow the mineral oil to be incorporated into the composition may be formed into monofilament, typically by in situ polymerization with the silica. In one or more of the well known extrusion methods. In other or the same embodi embodiments herein, the method may be devoid of silicone ments, the product may beformed into at least two twisted or 10 based or erucamide-based pulling lubricants. braided strands. In other or the same embodiments, the prod In one or more embodiments, from about 0.1 wt.% to about uct may beformed into a single layer film. In other or the same 12 wt.% of silica and from about 0.1 wt.% to about 12 wt.% embodiments, the product may be formed into a multilayer mineral oil may be mixed with the polyamide-producing film having at least two layers. In other or the same embodi monomer and water. In other embodiments, from about 1 wt. ments, the product may be formed into a molded part, such as 15 % to about 12 wt.% of silica and from about 1 wt.% to about by using known molding techniques. In other or the same 6 wt.% mineral oil may be mixed. In still other embodiments, embodiments, the product may be formed into a formed part from about more than 3 wt.% to less than 9 wt.% of both the by methods well known in the art. In other or the same silica and mineral oil, separately, may be mixed. In another embodiments, the product may be formed into a powder embodiment, about 6 wt.% silica and about 5 wt.% mineral coating. And in other or the same embodiments, the product oil are mixed. Furthermore, where mineral oil is the only may be formed into a spray coating. lubricant additive used with silica, the ratio of silica to min Any known monomer Suitable for producing a polyamide eral oil is from about 100:1 to about 1:1.5. In other embodi when polymerized may be used in the present invention ments, the ration of silica to mineral oil is from about 1.5:1 to described above. In some embodiments of the present inven about 1:1.5. In another embodiment the ratio of silica to tion, the at least one polyamide-producing monomer may be 25 mineral oil is about 6:5. selected from caprolactam, 11-amino undecanoic acid, and In some embodiments where mineral oil, silica, the at least laurolactam So as to produce nylon 6, nylon 11 and nylon 12, one polyamide-producing monomer, and water are mixed, the respectively. In other embodiments, the at least one polya step of mixing may further include mixing at least one other mide-producing monomers includes at least two monomers lubricant additive other than mineral oil with the silica, min wherein hexamethylenediamine (HMD) is reacted with an 30 eral oil, the at least one polyamide-producing monomer, and acid selected from adipic acid (to produce nylon 6.6), azelaic the water to form an emulsion prior to polymerization, acid (to produce nylon 6.9), sebacic acid (to produce nylon wherein the particulate silica, mineral oil and at least one 6.10), and dodecanedioic acid (to produce nylon 6,12). In other lubricant additive are substantially uniformly dispersed other embodiments, the polyamide-producing monomers in the emulsion. Such other lubricant additives may be may be made into polyamide copolymers by the addition of 35 selected from the group consisting of silicone oil, ester-based caprolactam (or lauralactam, where nylon 12 is desired as one fatty acids, petroleum jelly, petroleum-based oil, plant-based of the blocks) with the hexamethylenediamine and one of the oils, plasticizers, dibasic esters, silicones, anti-static amines, acid above. Such copolymers would include nylon 6/66 (with organic amities, ethanolamides, mono- and di-glyceride fatty adipic acid), nylon 6/69 (with azelaic acid), nylon 6/610 (with amines, ethoxylated fatty amines, Zinc Stearate, Stearic acids, sebacic acid) and nylon 6/612 (with dodecanedioic acid). In 40 palmitic acid, calcium Stearate, lead Stearate, Sulfates and Zinc still another embodiment, caprolactam may be copolymer Sulfates. The step of polymerizing may include polymerizing ized with laurolactam to produce nylon 6/12. In the present the at least one polyamide-producing monomer with the par invention, any diamine can essentially be added with any ticulate silica, the mineral oil, and the at least one other diacid to produce a polyamide matrix Suitable for the present lubricant additive all substantially uniformly dispersed in situ invention. Likewise, at least one polyamide-producing mono 45 to provide a polyamide matrix wherein the particulate silica, mer can be selected from any number of diamines (typically the mineral oil and the at least one other lubricant additive at least one) and any number of diacids (typically at least two) remains substantially uniformly dispersed in the resulting Sufficient to produce a polyamide copolymer. In one embodi polyamide matrix to form the polyamide-based composition. ment, the at least one polyamide-producing monomer is In a more particular embodiment, the step of mixing includes caprolactam. 50 first mixing the at least one polyamide-producing monomer In one or more embodiments herein of the present inven with water to form a reaction mixture; then adding particulate tion, the silica is amorphous. In other or the same embodi silica to the reaction mixture to form a Suspension; and then ments herein, the silica is micronized. In other or the same adding mineral oil to form a first emulsion and then adding embodiments herein, at least 0.1 wt.% of silica is loaded or other lubricant additives to the first emulsion to forma second mixed with the polyamide-producing monomer and water. In 55 emulsion before commencement of polymerization, such that other embodiments, from about 1 wt.% to about 12 wt.% of the silica aids the distribution of the mineral oil and the at least silica is loaded. In other or the same embodiments herein, one other lubricant additive substantially uniformly through from more than 3 wt.% to less than 9 wt.% of silica is loaded. out the second emulsion. In other embodiments, more than 4 wt.% to less than 8 wt.% In one or more embodiments, from about 0.01 wt.% to of silica is mixed. In one embodiment, the silica is loaded at 60 about 12 wt.% of the at least one other lubricant additive may 6 wt.%. In other or the same embodiments, the silica may be be mixed. In other embodiments, from about 0.1 wt.% to characterized by an average particle size of from about 1 about 10 wt.% of the at least one other lubricant additive may micron to about 20 microns. In other or the same embodi be mixed. In still other embodiments, from about 1 wt.% to ments, the silica may be characterized by an average particle less than 9 wt.% of the at least one other lubricant additive size of from about 2 microns to about 12 microns. In other or 65 may be mixed. In another embodiment, about 3 wt.% of the the same embodiments herein, the silica may be characterized at least one other lubricant additive may be mixed. Where by an average particle size from about 4 microns to about 11 anotherlubricant additive other than mineral oil is mixed with US 8,883,917 B1 13 14 silica and mineral oil, the ratio of silica to mineral oil and at least particulate silica, and optionally, mineral oil and other least one other lubricant additive combined is from about lubricant additives, that is substantially uniformly dispersed 1:1.5 to about 100:1. That is, the total combined amount of all within the polyamide matrix. Such a polymer composition, lubricant additives including mineral oil and any other lubri when made or formed in products, has been found to have a cant additive should not be more than 1.5 times the amount of 5 lower surface coefficient of friction than other polymer com silica used. More preferably, the amount of the combined positions that do not incorporate particulate silica and/or min amounts of lubricant additives, including mineral oil and eral oil. Importantly, it is well known that particulate silica other lubricant additives, should not be greater than the amount of silica used. and, when added, mineral oil or other lubricating agents, Yet another aspect of this invention may be achieved by a aggregate and/or migrate to the Surface of the product when polyamide-based composition comprising a polyamide 10 added via well known post-polymerization processes Such matrix having silica Substantially uniformly dispersed within that the present invention provides a novel product. the polyamide matrix. In other embodiments, the polyamide More particularly, the present invention overcomes the based composition may comprise a polyamide matrix having aggregation and/or migration problem by mixing the particu silica and mineral oil substantially uniformly dispersed late silica and, optionally, mineral oil and/or other lubricant within the polyamide matrix. In still other embodiments, the 15 additives, prior to or during polymerization of the polyamide polyamide-based composition may comprise a polyamide producing monomers. That is, the present invention mixes the matrix having silica, mineral oil and at least one other lubri particulate silica and, optionally, mineral oil and/or other cant additive substantially uniformly dispersed within the lubricant additives, with one or more polyamide-producing polyamide matrix. Such other lubricant additives may be monomers and water pre-polymerization to provide a liquid selected from the group consisting of silicone oil, ester-based Suspension or emulsion that can be in situ polymerized and, fatty acids, petroleum jelly, petroleum-based oil, plant-based optionally, pelletized and dried, to form a polyamide matrix. oils, plasticizers, dibasic esters, silicones, anti-static amines, Because particulate silica and, optionally, mineral oil and/or organic amities, ethanolamides, mono- and di-glyceride fatty other lubricant additives, are added and substantially uni amines, ethoxylated fatty amines, Zinc Stearate, Stearic acids, formly dispersed with the polyamide matrix and water before palmitic acid, calcium Stearate, lead Stearate, Sulfates and Zinc 25 polymerization or as polymerization occurs (i.e., before or Sulfates. Such polyamide-based compositions have inherent during polymerization pre-polymerization), the particulate lubricity such that, when made or otherwise formed into desired products, the products have a lower coefficient of silica (and mineral oil and/or other lubricant additives, when friction as compared to those products produced from com added) have been found to remain substantially uniformly positions that are devoid of any silica, or devoid of any silica dispersed within the resultant polymer matrix that forms the and mineral oil, in the polyamide-based composition. 30 polyamide-based composition. Such a polyamide-based composition is believed to have Furthermore, products made from the polyamide-based multiple applications, including use in as films, textiles, composition have been found to inherently possess a lower monofilaments, extruded parts, compounded parts, casted Surface coefficient of friction than other polyamide composi parts, molded parts and coatings. Still further, the composi tions polymerized without silica, (and/or mineral oil, or lubri tion is seen as a suitable for use as an emulsion. Such an 35 cating agents) added after polymerization. Thus, the polya emulsion of this type could be expanded to carry other hydro mide-based compositions of the present invention made from phobic moieties into the polymer matrix for the one of many the above described process have been found to be particu different purposes including, but not limited to, drug delivery, larly useful in products where low surface coefficient of fric fragrance, slip agents, anti-stats, pesticides, herbicides, fer tions are desirable. Such products made from the polyamide tilizers, antiseptics, antimicrobials, and organic dyes. 40 based composition of the present invention include, but are not limited to, extruded parts, compounded parts, casted BRIEF DESCRIPTION OF THE DRAWINGS parts, molded parts, films, filaments, fibers, jackets and sheaths, More particularly, compositions of the present inven All advantages of the present invention will become better understood with regard to the following description, tion are believed to be particularly useful in, but limited to, appended claims, and accompanying drawings wherein: 45 low friction cables or "slick” sheaths for cables commonly FIG. 1 is schematic flow chart of the prior art production of used in building wire. In at least one embodiment of the products made from polyamide-based compositions, wherein present invention, the resultant polymer matrix or composi FIG. 1A shows the polymerization of a polyamide-based tion can be used without the need for further addition of composition of the prior art, and wherein FIG. 1B shows the lubricating agents via a compounding/extrusion process. production of a product such as wire or cable using lubricat 50 The proposed mechanism for this phenomenon is the Sub ing agents added post-polymerization during an extrusion stantially homogeneous disbursement of silica particles process to the prior art polyamide-based composition; throughout the polyamide matrix. Without being bound by FIG. 2 is a schematic flow chart of the production of prod theory, it is believed that by creating a microscopically rough ucts made from polyamide-based compositions, wherein ened Surface, the contact points of the polymeric Surface from FIG. 2A shows the polymerization of a polyamide-based 55 the media that it is in contact with would be reduced, thereby, composition prepared according to the present invention, and reducing any Van der Waals forces or ionic interactions. It is wherein also believed that by utilizing high loadings of high pore FIG. 2B shows the production of a product such as wire or Volume silica, a higher loading of mineral oil or other lubri cable according to the present invention; cant additives may be incorporated into the polyamide matrix FIG.3 is section view of cable according to the concepts of 60 without leaching, which is common to conventionally com the present invention. pounded nylon compositions with oils and other lubricating agents. DETAILED DESCRIPTION OF PREFERRED With regard to the Figures, FIG. 1 is a schematic represen EMBODIMENTS tation of a prior art approach to the production of nylon and 65 products made from polyamide-based compositions prepared The present invention relates to the production of a polya from the nylon. In the prior art, FIG. 1A presents a method for mide-based (nylon polymer) composition that includes at the polymerization of nylon wherein at least one nylon-pro US 8,883,917 B1 15 16 ducing monomer 12 and water 14 are first mixed in a reaction tion of a polyamide-based composition is depicted, wherein mixing vessel 16, typically by stirring with a stirrer 18, to particulate silica 111 and, optionally, at least one lubricant form a reaction mixture. The reaction mixture comprising additive 113, such as, but not limited to, mineral oil, are mixed only the monomer(s) and water is then Subjected to polymer with at least one polyamide-producing monomer 112, and ization as shown at 20. Upon polymerization, the resultant water 114, in a reaction mixing vessel 116, typically provided nylon may be subjected to pelletizing as shown at 22 to with a stirrer 118. to form a reaction mixture. More particu provide nylon pellets. The nylon pellets, denoted by dotted larly, the at least one polyamide-producing monomer 112 line 24, may include residual nylon-producing monomer. may be mixed with water 114 to form a reaction mixture. Thus, the nylon pellets may be subject to extraction, as shown Then, particulate silica 111 may be added to the reaction at 26, of the nylon-producing monomer from the nylon pel 10 mixture to form a Suspension. Then, optionally, mineral oil lets. The nylon pellets 24 may further be subjected to drying and/or one or more other lubricant additives 113, may be the nylon pellets, as at 28, to lower the moisture level therein. added to the Suspension to form an emulsion before com Once extracted and dried, the nylon pellets 24 may be pack mencement of polymerization. Notably, the resultant Suspen aged. Such as into container(s) 30 and shipped from the poly sion (where silica only is added) or emulsion (where one or mer manufacturer, as by a moving vehicle 32 capable of 15 more oils are added) is mixed so that the silica and, where carrying the containers 30 of the nylon pellets to a product added, the mineral oil and/or one or more other lubricant manufacturer. It will be appreciated that all steps of the nylon additives, are substantially uniformly dispersed in the polya polymer manufacturing process after polymerization are con mide-producing monomer and water reaction mixture. sidered to be post-polymerization steps, including pelletiz Once mixed, the Suspension or emulsion of Substantially ing, extraction of residual monomer, drying, and shipment of uniformly dispersed ingredients is then Subjected to polymer the nylon pellets 24 to the product manufacturer. ization as shown at 120 such that the polyamide producing In FIG. 1B, it is well known that upon receiving the ship monomer is converted to a polyamide matrix. Thus, all silica ment of containers 30 of nylon pellets, the containers 30 may and any lubricant additives, including mineral oil, if added, be removed from the moving vehicle 32 and opened. The are added prior to polymerization (i.e., pre-polymerization) nylon pellets may be removed from the container 30 and 25 of the polyamide-producing monomer. Upon polymerization, placed into a hopper (not shown) for further processing and the resultant polyamide-based composition includes at least formation into a product. In the formation of the product, the silica, and if added, mineral oil and/or other lubricant addi nylon pellets may be subsequently remelted and formed into tives, which remain substantially uniformly dispersed a desired product. For example, in some cases, the product therein. may beformed by extruding the nylon pellets into an extruded 30 The resultant polyamide-based composition may then be product. In other cases, the product may be formed by com subjected to pelletizing as shown at 122 to provide pellets of pounding the nylon pellets into a compounded product. In polyamide-based composition. The pellets, denoted by dotted still other cases, the product may be formed by casting the line 124, may include residual polyamide-producing mono nylon pellets into a casted product. In yet other cases, the mer. Thus, the pellets 124 may be subject to extraction of the product may be formed by molding the nylon pellets into a 35 polyamide-producing monomer as shown at 126. To extract molded product. And in still other cases, the product may be the residual monomer, the polyamide-based composition is formed by thermoforming the nylon pellets into a thermo move to another reactor or vesseland then turned and tumbled formed product. All of these cases are schematically repre with near boiling water (180-200°F.) in order to leach out the sented by the machine 34 used to extrude, compound, cast, residual monomer. This results in a polyamide-based compo mold, or thermoform the product. 40 sition with about 8% or less residual monomer. In one or more It is noted here that during formation of the product, one or embodiments, the residual monomer after extraction to a level more lubricating agents, as shown at 36, are well known to be of 3%. In other embodiments, the residual monomer after added and incorporated into the remelted nylon material. extraction is reduced to a level of less than 2%. In yet another Such lubricating agents, as noted above, include silicone embodiment, the residual monomer after extraction is 0.9% based oils and erucamide-based oils, and other such pulling 45 or less. lubricants, as well as processing lubricants that aid in the The pellets 124 may further be subjected to drying, as at formation of the resultant product as depicted Schematically 128, to lower the moisture level therein. In one embodiment, as film 38 or cable 40. the pellets 124 may be dried to a moisture level of 1.8% or It will be appreciated that more than one of these product less. Once extracted and dried, the pellets 124 may be pack formation steps can be employed in the prior artin Subsequent 50 aged, such as into container(s) 130, and shipped from the steps. For example, the container(s)30 of nylon pellets 24 can polymer manufacturer, as by a moving vehicle 132 capable of be first shipped to a compound manufacturer who would take carrying the containers 130 of the pellets to a product manu the nylon pellets 24, remelt them, add a lubricating agent 36, facturer. Notably, the pellets 124 have inherent lubricity inas and repelletize the compounded product for further delivery much as the silica and/or mineral oil and other lubricant to a further product manufacturer, who may then receive the 55 additives remain substantially uniformly dispersed in the compounded pelletized product for use in an extrusion or resultant polyamide-based composition. molding process by remelting the compounded pelletized In FIG. 2B, the preparation of a product made from the product and making a new product 40 from the compounded polyamide-based composition provided and schematically pelletized product. However, it will be understood that the shown in FIG. 2A is shown. Specifically, upon receiving the addition of a lubricating agent occurs after the polymerization 60 shipment of containers 130 of pellets, the containers 130 may (i.e., post-polymerization) of the nylon regardless of the num be removed from the moving vehicle 132 and opened. The ber of product formation steps employed. pellets 124 may be removed from the container 130 and With respect to the FIG. 2, a schematic representation of placed into a hopper (not shown) for further processing and the approach to the production of polyamide-based compo formation into a product. In the formation of the product, the sitions of the present invention (FIG. 2A) and products made 65 pellets may be subsequently remelted and formed into a from polyamide-based compositions of the present invention desired product. For example, in Some cases, the product may (FIG. 2B), is depicted. In FIG. 2A, a method for the prepara be formed by extruding the pellets into an extruded product. US 8,883,917 B1 17 18 In other cases, the product may be formed by compounding oil uniformly dispersed therein. In still other embodiments, the pellets into a compounded product. In still other cases, the the polyamide-based composition of the present invention is product may be formed by casting the pellets into a casted characterized as having silica, mineral oil and other lubricant product. In yet other cases, the product may be formed by additives uniformly dispersed therein. molding the pellets into a molded product. And in still other 5 It will be appreciated that the need for an outer jacket cases, the product may be formed by thermoforming the exhibiting a low coefficient of friction is met by the present pellets into a thermoformed product. All of these cases are invention. More generally, the need for an easy to manufac schematically represented by the machine 134 used to ture, low coefficient offriction polyamide-based composition extrude, compound, cast, mold, or thermoform the product. is also met by the invention. By incorporating silica and, It is noted here that, in contrast to the prior art, no lubricat 10 ing agents are added during the formation of the product, as optionally, mineral oil and/or other lubricant additives, into the pellets provided for the formation of the product already the polyamide matrix via in situ polymerization in one or have inherent lubricity. Thus, in at least one embodiment of more embodiments, an innovative polymer composition Suit the present invention, no lubricating agents are added to the able, for example, for use in the manufacture of low slick remelted polyamide-based compositions that are used to form 15 cables is provided. the product, as depicted schematically as film 138 or cable Nylon is the generic name for a family of polyamide poly 140. mers characterized by the presence of an amine ( NH) It will be appreciated that more than one of the product group and an acid (-C=O) group within the monomer. The formation steps can be employed in Subsequent steps. For most basic chemical form of nylon is example, the container(s) 130 of pellets 124 can be first shipped to a compound manufacturer who would take the pellets 124, remelt them, provide additional compounding O additives, if desired, and repelletize the compounded product for further delivery to a further product manufacturer, who may then receive the compounded pelletized product for use 25 in an extrusion or molding process by remelting the com where R is any saturated or unsaturated, branched or pounded pelletized product and making a new product 40 unbranched, Substituted or unsubstituted, aliphatic, cyclic or from the compounded pelletized product. However, it will be aromatic hydrocarbon and a and n separately equal any posi understood that there would be no need to add any lubricating tive integer. This is considered an AB type nylon, the A agents to the remelted pellets of polyamide-based composi 30 referring to the acid and the B referring to the amine. Where tion either at the compounding stage or the extrusion/molding a=6, caprolactam is produced as the monomer, nylon 6 being stage as set forth in the above example, since the pellets the polymer produced therefrom. Otherwell known of already have inherent lubricity as discussed above. the AB type include nylon 11 and 12, wherein the numeral Among the many uses for Such polyamide-based (also sets forth the number of primary carbons within the structure. known as nylon-based) compositions of the present invention 35 More specifically, the polymerization of 11-amino unde include the production ofbuilding wire or cables. Referring to canoic acid produces nylon 11, while the polymerization of FIG. 3, a representation of a cable according to the present laurolactam produces nylon 12. invention is depicted. The cable 200 is shown with an outer In addition to the above nylons, other nylons are charac jacket 202 surrounding an insulating layer 204. The outer terized by the use of diacids and diamines to produce a poly jacket 202 and insulating layer 204 may together be referred 40 mer having the general chemical structure to as a sheath. Typically, a jacket is the exterior-most portion of the sheath and may be up to 10 mils thick. The sheath covers and protects the conducting core 206 which may con O O sist of a single metal wire, multiple Small wires twisted together to make a “stranded' cable, or multiple insulated 45 wires or other type electrical conductors. The composition of the present invention may be used to provide the outerjacket where R' and R" may be the same or different and, like R 202, which may comprise one or more layers of polymeric above, are any saturated or unsaturated, branched or materials to provide physical, mechanical, electrical insulat unbranched, Substituted or unsubstituted, aliphatic, cyclic or ing and/or chemical protection for the underlying cable com 50 aromatic hydrocarbon, b and c are separately any positive ponents. The insulating layer 204 may be made of polymeric integer, and X and y equals molar percent 1 to 99%. These materials selected from the group consisting of polyethyl AABB type nylons, i.e., those polyamides characterized by ene, polypropylene, polyvinylchloride, organic polymeric diamine and diacid monomers, are well known in the art. The thermosetting and thermoplastic resins and elastomers, poly most common of these types of nylons is nylon 6.6 (hexam olefins, copolymers, vinyls, olefin-vinyl copolymers, polya 55 ethylenediammonium adipate) which includes a 6 carbon mides, acrylics, polyesters, fluorocarbons, and the like. In one diamine (e.g., hexamethylenediamine) and a 6 carbon diacid or more embodiments, the insulating layer 204 is made of monomer (e.g., adipic acid). Other Such nylons include, inter polyvinyl chloride (PVC) electrical insulation. alia, nylon 6.9, nylon 6,10, nylon 6,12, produced by the poly As noted above, the outerjacket 202, or exteriorportion of merization reaction of hexamethylenediamine with a diacid the sheath, of the cable according to the present invention is 60 selected from azelaic acid (to make nylon 6.9), sebacic acid comprised of a polymer material. In one or more embodi (to make nylon 6.10) or dedecanedioic acid (to make nylon ments, the polymeric material is a polyamide as will be dis 6,12). cussed in more detail below. In some embodiments, the Polymers of the AABB type having high molecular polyamide-based composition of the present invention is weights can be derived as condensation products from the characterized as having silica uniformly dispersed therein. In 65 reaction of fatty dibasic acids (e.g., Cs, Co., C2, and Cs) other embodiments, the polyamide-based composition of the and di- and polyfunctional amines. For purposes of this dis present invention is characterized as having silica and mineral closure, the term “fatty dibasic acid' will refer to any of the US 8,883,917 B1 19 20 high molecular weight diacids of at least 15 primary carbon of safety and performance, chemically inert amorphous silica units. Examples include pentadecanedioic acid, commonly is used. The silica may be further characterized by high poros known to have 15 carbon units (Cs), and carboxy Stearic acid, ity and Surface area. High pore Volume silica has more par commonly known to have 19 carbon units (C). A more ticles per weight, thereby providing higher efficiency. Fur complete description of fatty acids as they relate to the pro thermore, the high pore Volume silica enables Saturation of a duction of polyamides can be found in “Polyamides from high loading of mineral oil to be incorporated into the silica Fatty Acids. Encyclopedia of Polymers. Vol. 11, pp. 476-89 particles and hence incorporated together into the polyamide (1988), which is incorporated herein by reference. Those matrix. skilled in the art will readily appreciate that a high molecular In one or more embodiments, the particulate silica of the diacid, Such Cs, can be changed into a high molecular 10 invention may be micronized to yield uniform, precisely diamine through known chemical reactions. Generally it is defined particle sizes and distribution profiles. In one or more known in the art that nylon 6.36 and other fatty acid/diamine embodiments the silica particles of the invention are high based polymers are not soluble in typical Solvents such as purity, in other words the silica of the invention is no less than water, these polymers must be polymerized with chain termi 15 99.5% silicon dioxide. In one or more embodiments, the silica nators and low molecular weight acids to increase solubility. of the invention may be characterized by an oil absorption Polyamides, also referred to interchangeably herein as value from about 190 to about 300 lbs/100 lbs. In other nylon or PA, suitable for use in the present invention include embodiments, the silica of the invention may be characterized homopolymers nylon 6, nylon 6.6, nylon 6.9, nylon 6.10, by an oil absorption value from about 220 to about 290 nylon 11, nylon 12, as well as copolymers nylon 6/66, nylon bS/100 lbs. 6/610, and nylon 6/12. Other copolymer examples may In one or more embodiments, the silica of the invention include /610 or nylon 66/12. Non-limiting examples may be characterized by an average pore Volume in the range of polymers suitable in the present are listed in Table 1. from about 1.25 to about 1.60 mL/g. Commercially available silica useful in one or more embodiments of the present TABLE 1. 25 invention includes antiblocking additive Fuji Silysia, charac terized by an average particle size from about 3.1 um to about Polyanide-producing monomer(s 20.0 um. In at least one embodiment of the present invention, Polyamide Polyamide-producing monomer(s) the silica is characterized by an average particle size from Homopolymer about 3.1 um to about 20.0 um. In one or more embodiments 30 of the present invention, the silica may be characterized by an Nylon 6 or PA6 e-Caprolactam average particle size from about 4 um to about 11 Jum. In at Nylon 6.6 or PA 66 hexamethylenediamine and adipic acid least one embodiment of the present invention, grades of Nylon 6.9 Hexamethylenediamine and azelaic acid Nylon 6,10 Hexamethylenediamine with Sebacic acid silica selected from grade 310P silica (“31OP silica”) of 2.7 Nylon 6,12 hexamethylenediamine with dodecanedioic acid um particle size, grade 430 silica of 4.1 um particle size, grade Nylon 11 11-amino undecanoic acid 35 460 silica of 11.0 um particle size, or mixtures thereof, are Nylon 12 laurolactam used. Copolymer In at least one embodiment of the present invention, a PA 666 caprolactam, hexamethylenediamine and adipic acid loading of silica from about 1% to about 12% total weight of PA 6610 caprolactam, hexamethylenediamine, and Sebacic acid the polymer composition is incorporated. The polymer com Nylon 6/12 caprolactam and laurolactam 40 position includes more than 2 wt % silica; in other embodi Nylon 66/610 hexamethylenediamine, adipic acid and sebacic acid ments more than 3 wt % silica; in other embodiments at least Nylon 66/12 laurolactam, hexamethylenediamine, adipic acid 4 wt % silica; and in other embodiments, from more than 3 wit % to less than 9 wt % silica. In at least one embodiment of the In one or more embodiments, the at least one polyamide present invention, the polyamide-based composition includes producing monomer is selected from caprolactam, 11-amino 45 from about 4 to about 8 wt % silica. In at least one embodi undecanoic acid, laurolactam, or mixtures thereof. ment of the present invention, the polyamide-based compo In other embodiments, the at least one polyamide-produc sition includes from about 5 to about 7 wt % silica. In at least ing monomer is selected from hexamethylenediamine, adipic one embodiment of the present invention, the polyamide acid, azelaic acid, sebacic acid, 12-carbon dibasic (dode based composition includes about 6 wt % silica. canedioic) acid, caprolactam, or mixtures thereof, or mix 50 Certain oils have been known for some time in the art to tures with caprolactam or laurolactam, to produce copoly provide lubricity to polymeric made products. Examples of CS. Such lubricants include fatty amides and metallic fatty acids In one or more embodiments, polyamides for use in the include, but are not limited to erucamide, oleamide, oleyl present invention include: Nylon 6, also known as Polyamide palmitamide, Stearyl Stearamide, Stearamide, behenamide, 6 or PA6. Nylon-6 is made from a single monomer called 55 ethylene bisStearamide, ethylene bisoleamide, Stearyl eruca caprolactam, also known as 6-amino-caproic acid or c-Ca mide, erucyl Stearamide, and the like. Advantageous hydro prolactam. In one or more embodiments, the at least one carbon oils include, but are not limited to, mineral oil, silicone polyamide-producing monomer is caprolactam. oil, and the like. Examples of other lubricating materials In one or more embodiments, the polymer of the invention include plasticizers, dibasic esters, silicones, anti-static includes silica particles uniformly dispersed in the polya 60 amines, organic amines, ethanolamides, mono- and di-glyc mide. Such materials are produced by the incorporation of eride fatty amines, ethoxylated fatty amines, fatty acids, Zinc silica particles into a polyamide matrix via in situ polymer Stearate, Stearic acids, palmitic acids, calcium Stearate, lead ization along with mineral oil. Silica, or as may be referred to Stearate, Sulfates Such as Zinc sulfate, etc., and the like. Yet interchangeably herein as silicon dioxide or SiO, particles other lubricating materials include fluorinated organic resins, may be crystalline or amorphous. Silica, as commonly used in 65 Such as a polymer of one or more fluorinated monomers paint, ink, plastic, paper, pharmaceutical, cosmetics indus selected from tetrafluoroethylene, vinylidene fluoride, chlo tries, may be used. In one or more embodiments, for reasons rotrifluoroethylene and the like. US 8,883,917 B1 21 22 It has been discovered that by using in situ polymerization, embodiment of the present invention, 1) a step of manufacture silica particles are more apt to disperse uniformly within a is removed wherein a separate pulling lubricant, or other polymer matrix. The attractiveness of silica particulates to lubricating agents, are not required to be compounded with certain oils is discussed in 'Stability of oil-in-water emulsions the polyamide-based composition; 2) a more dispersed, stabilised by silica particles” by BP. Binks and S O. Lums homogenous polyamide-based composition and product is don, Phys. Chem. Chem. Phys., 1999, 1,3007-3016, which is realized, and 3) the migration of mineral oil from the polymer incorporated herein by reference. Thus, an aspect of the matrices is reduced because of the inclusion of the oil in the present invention is to incorporate the mineral oil into the silica particulates. silica for dispersion into the polymer matrix. As such, it has By incorporating oils into the polyamides of the present been found that not only does the silica disperse evenly, but 10 invention, further applications for this material are envi also the mineral oil does as well. Importantly, it also does so Sioned. By optimizing the combination of silica particulates without significant leaching of the mineral oil. Thus, it is in concentration and size, the concentration of mineral oil, desirable in the present invention to form an "emulsion' in and the extraction level, it has been found to decrease the aqueous formulations in order that the silica act as a Suitable coefficient of friction of a polyamide product. It is believed carrier of the oils during the in situ polymerization. In one or 15 that products of the present invention provide a significant more embodiments of the invention, silica particles are dis reduction in surface coefficient of friction over standard prod persed in mineral oil, also known as white mineral oil or ucts that incorporate lubricating agents, and on par with simi petroleum, during the in situ polymerization technique. In at lar "slick” products (commercially available by Encore SS least one embodiment of the present invention, commercially and Nylene) produced by other compounded methods, which available mineral oil may be used such as BRITOL(R) 7 NF necessitate separate compounding step with pulling lubri White Mineral Oil (Sonneborn, Inc., Mahwah, N.J.) charac Cant. terized by a viscosity in the range of 10.80-13.60 cSt. A low coefficient of friction composition according to the In at least one embodiment of the present invention, a present invention may be applied advantageously in film and/ loading of mineral oil from about 0.1 wt.% to about 12 wt.% or coating technology, textiles, monofilaments, and molded total weight of the polymer composition is incorporated. In at 25 parts. An emulsion according to the polyamide composition least one embodiment of the present invention, the polymer of the present invention may be expanded upon to carry other composition includes a mineral oil component of more than 2 hydrophobic moieties into the polymer matrix for the pur wt %, in other embodiments more than 3 wt %, in other poses of drug delivery, fragrance, slip agents, anti-stats, pes embodiments more than 4 wt %, in other embodiments, from ticides, herbicides, fertilizers, antiseptics-antimicrobial for about 1 wt.% to about 10 wt %, and in other embodiments, 30 mulations, or organic dyes. from about more than 3 wt.% to less than about 9 wt.%. In Various modifications and alterations that do not depart another embodiment of the present invention, the polymer from the scope and spirit of this invention will be apparent to composition includes about 5 wt % mineral oil. those skilled in the art. This invention is not to be duly limited By using a high (e.g., having an average pore Volume of at to any illustrative embodiments set forth herein. least 1.25 mL/g) pore Volume silica as in the present inven 35 In light of the foregoing, it should thus be evident that the tion, the silica may act like a sponge and absorb a higher method and composition of the present invention Substan loading of mineral oil. The mineral oil may be absorbed and tially improves the art. The method of the present invention incorporated into the polyamide matrix during in situ poly provides for the in situ polymerization at least one polyamide merization. In at least one embodiment of the present inven producing monomer with silica and, optionally, mineral oil, tion, the weight percent of silica is substantially equal to the 40 to yield a polyamide matrix in which the silica and, option weight percent of mineral oil. Excess mineral oil or oversatu ally, mineral oil, is uniformly dispersed throughout the polya ration of the silica is undesirable as the excess mineral oil mide matrix. Advantageously, the polyamide materials of leaches out from the polymer matrix. In at least one embodi certain embodiments have been shown to have a low coeffi ment of the present invention, the silica to mineral oil ratio (by cient of friction while being substantially devoid of silicone weight) is from about 100:1 to about 1:1.5. In other embodi 45 based or erucamide-based oils or other known pulling lubri ments of the present invention, the silica to mineral oil ratio is cants or lubricating agents. 1:5:1 to about 1:1.5. While, in accordance with the patent statutes, only the Typically, two industry-standard processes are used to pro preferred embodiments of the present invention have been duce a cable using the outer sheath composition of the present described in detail hereinabove, the present invention is not invention: the so called co-extrusion method and the tandem 50 necessarily to be limited thereto or thereby. Rather, the scope extrusion method. In both processes, the conductor, either of the invention shall include all modifications and variations solid or stranded, is first introduced into the extrusion head that fall within the scope of the attached claims. where the heated, melted PVC insulation compound is intro duced and applied to the circumference of the conductor. In What is claimed is: the co-extrusion process, the melted nylon compound is intro 55 1. A method for the preparation of a polyamide-based duced into the same extrusion head and applied together with composition comprising particulate silica Substantially uni the PVC to the conductor, in a two-layer orientation. In the formly dispersed into a polyamide matrix, the method com tandem process the PVC-coated conductor leaves the first prising: extrusion head and is introduced into a second, separate first mixing at least one polyamide-producing monomer extrusion head where the melted nylon is applied to the sur 60 with water to form a reaction mixture and then adding face. In both cases, the final product is then introduced into a more than 2 weight percent particulate silica to the reac cooling water bath and ultimately the cooled product is tion mixture to form a suspension wherein the particu wound onto reels. late silica is substantially uniformly dispersed therein; A polyamide-based composition Suitable for use as an then polymerizing the at least one polyamide-producing outerjacket of a wire or cable according to the present inven 65 monomer with the particulate silica Substantially uni tion provides advantages over the extruded finished polymers formly dispersed in situ to provide a polyamide matrix of the prior art as used for wires or cables in that, in at least one wherein the particulate silica remains substantially uni US 8,883,917 B1 23 24 formly dispersed in the resulting polyamide matrix to 18. The method of claim 1, wherein more than 3 wt.% form the polyamide-based composition. particulate silica is mixed. 2. The method of claim 1, wherein the step of mixing the 19. The method of claim 1, wherein the step of mixing silica and polyamide-producing monomer is performed with further includes mixing at least one lubricant additive out the addition of lubricant additives. selected from the group consisting of silicone oil, fatty 3. The method of claim 1, wherein the polyamide-based amides, metallic fatty acids, ester-based fatty acids, petro composition includes residual polyamide-producing mono leum jelly, petroleum-based oil, mineral oil, plant-based oils, merand further comprising the step of extracting the residual plasticizers, dibasic esters, silicones, anti-static amines, polyamide-producing monomer from the polyamide-based organic amities, ethanolamides, mono- and di-glyceride fatty 10 amines, ethoxylated fatty amines, Zinc Stearate, Stearic acids, composition to a level of less than 8%. palmitic acid, calcium Stearate, lead Stearate, Sulfates and Zinc 4. The method of claim 1, further comprising the step of Sulfates, with the silica, the at least one polyamide-producing drying the polyamide-based composition to remove mois monomer, and the water to form an emulsion prior to poly ture. merization, wherein the particulate silica and the at least one 5. The method of claim 4, wherein the step of drying 15 lubricant additive is substantially uniformly dispersed in the includes drying the polyamide-based composition to a mois emulsion. ture level of 1.8% by weight or less. 20. The method of claim 19, wherein the step of mixing the 6. The method of claim 1, further comprising pelletizing lubricant additive includes first mixing the at least one polya the polyamide-based composition. mide-producing monomer with water to form a reaction mix 7. The method of claim 1, further comprising forming the ture; then adding particulate silica to the reaction mixture to polyamide-based composition into a product by performing form a suspension; and then adding the at least one lubricant any one of the following steps selected from the group con additive to the Suspension before commencement of polymer sisting of extruding the polyamide-based composition into an ization to form an emulsion, such that the silica aids the extruded product, compounding the polyamide-based com distribution of the at least one lubricant additive substantially position into a compounded product, casting the polyamide 25 uniformly throughout the emulsion. based composition into a casted product, molding the polya 21. The method of claim 19, wherein the step of polymer mide-based composition into a molded product, and izing includes polymerizing the at least one polyamide-pro thermoforming the polyamide-based composition into a ther ducing monomer with the particulate silica and the at least moformed product, wherein any of the resultant products one lubricant additive substantially uniformly dispersed in have a lower surface coefficient of friction than a product 30 situ to provide a polyamide matrix wherein the particulate substantially devoid of silica or where silica was added to the silica and the at least one lubricant additive remains Substan polyamide matrix after polymerization. tially uniformly dispersed in the resulting polyamide matrix 8. The method of claim 7, wherein the polyamide-based to form the polyamide-based composition. composition is formed into a sheath or jacket of a cable or 22. The method of claim 19, wherein about 0.01 wt.% to W1e. 35 about 12 wt.% of the at least one lubricant additive is mixed. 9. The method of claim 8, wherein the polyamide-based 23. The method of claim 19, wherein the step of mixing composition is formed into an outside protective jacket in the further includes mixing mineral oil with the silica, the at least production of thermoplastic-insulated wires or cables for one polyamide-producing monomer, and the water to forman building wire applications. emulsion prior to polymerization, wherein the particulate 10. The method of claim 7, wherein the polyamide-based 40 silica and mineral oil are Substantially uniformly dispersed in composition is formed into a product selected from the group the emulsion. consisting of a monofilament, at least two twisted or braided 24. The method of claim 23, wherein the step of mixing the Strands, a single layer film, a multilayer film having at least mineral oil includes first mixing the at least one polyamide two layers, a molded part, a formed part, a powder coating, producing monomer with water to form a reaction mixture; and a spray coating. 45 then adding particulate silica to the reaction mixture to form 11. The method of claim 1, wherein the at least one polya a suspension; and then adding mineral oil to the Suspension mide-producing monomer is selected from caprolactam, before commencement of polymerization to form an emul 11-amino undecanoic acid, laurolactam, or mixtures thereof. sion, such that the silica aids the distribution of the mineral oil 12. The method of claim 1, wherein the at least one polya Substantially uniformly throughout the emulsion. mide-producing monomer is selected from hexamethylene 50 25. The method of claim 23, wherein the step of polymer diamine and a second polyamide-producing monomer is izing includes polymerizing the at least one polyamide-pro selected from adipic acid, azelaic acid, sebacic acid, and ducing monomer with the particulate silica and the mineral dodecanedioic acid. oil substantially uniformly dispersed in situ to provide a 13. The method of claim 1, wherein the at least one polya polyamide matrix wherein the particulate silica and the min mide-producing monomer is selected from any number of 55 eral oil remains substantially uniformly dispersed in the diamines and any number of diacids Sufficient to produce a resulting polyamide matrix to form the polyamide-based polyamide copolymer. composition. 14. The method of claim 1, wherein the particulate silica is 26. The method of claim 23, wherein about 1 wt.% to about amorphous. 12 wt.% mineral oil is mixed. 15. The method of claim 1, wherein the silica is micron 60 27. The method of claim 23, wherein the ratio of silica to ized. mineral oil is from about 1.5:1 to about 1:1.5. 16. The method of claim 1, wherein the particulate silica 28. The method of claim 23, wherein the step of mixing has an average particle size of between about 1 to about 20 further includes mixing at least one other lubricant additive lm. other than mineral oil selected from the group consisting of 17. The method of claim 1, wherein the particulate silica 65 silicone oil, ester-based fatty acids, petroleum jelly, petro has an average pore volume of from about 1.25 to about 1.60 leum-based oil, plant-based oils, plasticizers, dibasic esters, mL/g. silicones, anti-static amines, organic amities, ethanolamides, US 8,883,917 B1 25 26 mono- and di-glyceride fatty amines, ethoxylated fatty substantially devoid of silica or where silica was added to the amines, Zinc Stearate, Stearic acids, palmitic acid, calcium polyamide matrix after polymerization. Stearate, lead Stearate, Sulfates and Zinc sulfates, with the 38. The method of claim37, wherein the polyamide-based silica, mineral oil, the at least one polyamide-producing composition is formed into a sheath or jacket of a cable or monomer, and the water to form an emulsion prior to poly W1e. merization, wherein the particulate silica, mineral oil and at 39. The method of claim37, wherein the polyamide-based least one other lubricant additive are substantially uniformly composition is formed into an outside protective jacket in the dispersed in the emulsion. production of thermoplastic-insulated wires or cables for 29. The method of claim 28, wherein the step of polymer building wire applications. 10 40. The method of claim37, wherein the polyamide-based izing includes polymerizing the at least one polyamide-pro composition is formed into a product selected from the group ducing monomer with the particulate silica, the mineral oil, consisting of a monofilament, at least two twisted or braided and the at least one other lubricant additive all substantially Strands, a single layer film, a multilayer film having at least uniformly dispersed in situ to provide a polyamide matrix two layers, a molded part, a formed part, a powder coating, wherein the particulate silica, the mineral oil and the at least 15 and a spray coating. one other lubricant additive remains substantially uniformly 41. The method of claim 31, wherein the at least one dispersed in the resulting polyamide matrix to form the polya polyamide-producing monomer is selected from caprolac mide-based composition. tam, 11-amino undecanoic acid, laurolactam, or mixtures 30. The method of claim 28, wherein the ratio of silica to thereof. mineral oil and at least one otherlubricant additive combined 42. The method of claim 31, wherein the at least one is from about 1:1.5 to about 100:1. polyamide-producing monomer is selected from hexameth 31. A method for the preparation of an polyamide-based ylenediamine and a second polyamide-producing monomer composition comprising particulate silica and mineral oil is selected from adipic acid, azelaic acid, sebacic acid, and Substantially uniformly dispersed into a polyamide matrix, dodecanedioic acid. the method comprising: 25 43. The method of claim 31, wherein the at least one first mixing particulate silica, mineral oil, at least one polyamide-producing monomer is selected from any number polyamide-producing monomer, and water, to form an of diamines and any number of diacids sufficient to produce a emulsion or Suspension wherein the particulate silica polyamide copolymer. and mineral oil are substantially uniformly dispersed 44. The method of claim 31, wherein the particulate silica therein; 30 is amorphous. then polymerizing the at least one polyamide-producing 45. The method of claim 31, wherein the particulate silica monomer with the particulate silica and mineral oil sub is micronized. stantially uniformly dispersed in situ to provide a polya 46. The method of claim 31, wherein the particulate silica mide matrix wherein the particulate silica and mineral has an average particle size of between about 1 to about 20 oil remain substantially uniformly dispersed in the 35 lm. resulting polyamide matrix to form the polyamide 47. The method of claim 31, wherein the particulate silica based composition. has an average pore volume of from about 1.25 to about 1.60 32. The method of claim 31, wherein the step of mixing mL/g. includes first mixing the at least one polyamide-producing 48. The method of claim31, wherein from at least about 0.1 monomer with water to form a reaction mixture; then adding 40 wt.% to about 12 wt.% particulate silica and from at least particulate silica to the reaction mixture to forma Suspension; about 0.1 wt.% to about 12 wt.% mineral oil are mixed. and then adding mineral oil to the Suspension to form an 49. The method of claim 31, wherein the step of mixing emulsion before commencement of polymerization. further includes mixing at least one lubricant additive 33. The method of claims 31, wherein the polyamide-based selected from the group consisting of silicone oil, ester-based composition includes residual polyamide-producing mono 45 fatty acids, petroleum jelly, petroleum-based oil, plant-based merand further comprising the step of extracting the residual oils, plasticizers, dibasic esters, silicones, anti-static amines, polyamide-producing monomer from the polyamide-based organic amities, ethanolamides, mono- and di-glyceride fatty composition to a level of less than 8%. amines, ethoxylated fatty amines, Zinc Stearate, Stearic acids, 34. The method of claim 31, further comprising the step of palmitic acid, calcium Stearate, lead Stearate, Sulfates and Zinc drying the polyamide-based composition to remove mois 50 Sulfates, with the silica, the mineral oil, the at least one polya ture. mide-producing monomer, and the water to forman emulsion 35. The method of claim 34, wherein the step of drying prior to polymerization, wherein the particulate silica, the includes drying the polyamide-based composition to a mois mineral oil, and the at least one lubricant additive are sub ture level of 1.8% by weight or less. stantially uniformly dispersed in the emulsion. 36. The method of claim 31, further comprising pelletizing 55 50. The method of claim 49, wherein the step of mixing the the polyamide-based composition. at least one lubricant additive includes first mixing the at least 37. The method of claim 31, further comprising forming one polyamide-producing monomer with water to form a the polyamide-based composition into a product by perform reaction mixture; then adding particulate silica to the reaction ing any one of the following steps selected from the group mixture to form a suspension; then adding the mineral oil to consisting of extruding the polyamide-based composition 60 the Suspension to form a first emulsion; then adding the at into an extruded product, compounding the polyamide-based least one lubricant additive to the first emulsion to form a composition into a compounded product, casting the polya second emulsion before commencement of polymerization, mide-based composition into a casted product, molding the such that the silica aids the distribution of the mineral oil and polyamide-based composition into a molded product, and the at least one lubricant additive substantially uniformly thermoforming the polyamide-based composition into a ther 65 throughout the second emulsion. moformed product, wherein any of the resultant products 51. The method of claim 49, wherein the step of polymer have a lower surface coefficient of friction than a product izing includes polymerizing the at least one polyamide-pro US 8,883,917 B1 27 28 ducing monomer with the particulate silica, the mineral oil, and the at least one lubricant additive, which are all substan tially uniformly dispersed in situ to provide a polyamide matrix wherein the particulate silica, the mineral oil and theat least one other lubricant additive remains substantially uni formly dispersed in the resulting polyamide matrix to form the polyamide-based composition. 52. The method of claim 49, wherein the ratio of silica to mineral oil and at least one otherlubricant additive combined is from about 1:1.5 to about 100:1. 10 53. A polyamide-based composition comprising a polya mide matrix having silica Substantially uniformly dispersed within the polyamide matrix and wherein mineral oil is sub stantially uniformly dispersed within the polyamide matrix with the silica. 15 54. The polyamide-based composition of claim 53, wherein at least one other lubricant additive is substantially uniformly dispersed within the polyamide matrix with the silica and mineral oil.

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