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Home , Acrylate polymer

USOO5352500A United States Patent 19 11 Patent Number: 5,352,500 Memon 45 Date of Patent: Oct. 4, 1994

(54) THERMOPLASTC 56) References Cited COMPOSITIONS CONTAINING U.S. PATENT DOCUMENTS MELTRHEOLOGY MODIFERS 3,591,659 7/1971 Brinkmann et al...... 260/873 4,245,058 1/1981 Liu ...... 525/148 75 Inventor: Nazir A. Memon, Fallsington, Pa. 4,257,937 3/1981 Cohen et al. ... 260/40R 4,263,415 4/1981 Liu ...... 525/148 4,327,137 4/1982 Sawa et al...... 428/35.7 73) Assignee: Rohm and Haas Company, 4,544,706 10/1985 Finch et al...... 525/146 Philadelphia, Pa. 4,587,298 5/1986 Miller ...... 525/67 4,622,363 11/1986 Eichenauer et al...... 525/67 4,774,289 9/1988 Kress et al...... 525/146 [21] Appl. No.: 14,054 4,883,841 1/1989 Riew et al...... 525/148 22 Fied: Feb. 5, 1993 FOREIGN PATENT DOCUMENTS 0155989 2/1985 European Pat. Off. . Primary Examiner-Susan W. Berman Related U.S. Application Data Attorney, Agent, or Firm-Roger K. Graham (60) Division of Ser. No. 389,656, Feb. 18, 1992, aban doned, which is a continuation-in-part of Ser. No. 57 ABSTRACT 153,170, Feb. 8, 1988, abandoned. Acrylic having a minimum molecular weight of about 500,000, and preferably of about 1,500,000, are (51) Int. Cl...... B29D 22/00; B29D 23/00; blended at levels of from 1 to 25% with B32B 1/08 resins to improve the melt of the thermoplas (52) U.S. Cl...... 428/35.7; 428/36.5; tic resins and facilitate , , 525/146; 525/148; 264/46.4; 293/102; 180/89.1 extrusion and similar processes. 58 Field of Search ...... 428/35.7, 36.5; 525/146, 148; 264/46.4; 293/102; 180/89.1 8 Claims, No Drawings 5,352,500 1. 2 4,161,579, but these approaches with either THERMOPLASTC POLYMER COMPOSITIONS require careful control of melt reactivity or cause pro CONTAINING MELT-RHEOLOGY MOD FERS cessing times to be extended. having reac tive amine end groups may De reacted with groups on This is a division application of U.S. application Ser. 5 an additive, to tie together the molecules and No. 389,656, filed Feb. 18, 1992, now abandoned which effectively raise the molecular weight, as is taught by is a continuation-in-part application of U.S. application Owens et al. in U.S. Pat. No. 3,668,274 or Leslie et al. in Ser. No. 153,170 filed Feb. 8, 1988, now abandoned. U.S. Pat. No. 4,145,466. This method requires careful This invention relates to melt-rheology modifiers for control of stoichiometry, and may not be suited to less thermoplastic polymers, and more particularly to high O reactive polymers. molecular-weight acrylic polymers as melt-rheology The rheology of has been controlled modifiers, and to the thermoplastic polymers having by additives, such as the selectively hydrogenated block modified melt-rheology properties. of vinyl and olefins taught by BACKGROUND OF THE INVENTION Bussink et al. in British Patent No. 2,004,284, triazines 15 taught as softeners by Mark et al. in U.S. Pat. No. The compositions of the present invention are partic 4,159,974, blends with styrene-maleic anhydride co ularly well suited to blow-molding processes, by which polymers and styrene- copolymers taught thin-walled articles such as bottles are formed from a by Henton in U.S. Pat. No. 4,218,544 and the like. partially shaped, usually hollow polymer article known Acrylic and methacrylic copolymers have been as a parison. The parison is formed by well-known pro added to resins or -polycarbon cesses such as extrusion or injection molding; it is then ate blends as impact modifiers; these copolymers typi typically placed in a final mold, expanded by gas pres cally possess a core-shell (multi-stage) morphology, and sure to conform to the shape of the final mold and they have relatively low molecular weights, generally cooled to fix its shape. Variations of this process are below about 300,000. Such copolymers are taught in, well known in the art, and it may be used with many 25 for example, Liu, U.S. Pat. No. 4,245,058, Cohen et al., thermoplastic polymers. Such polymers that have been U.S. Pat. No. 4,257,937, Fromuth et al., 4,264,487 and used by others to form blow-molded articles include Brinkmann, U.S. Pat. No. 3,591,659. Such impact-modi poly(), or PVC, poly(ethylene terephthal fying polymers preferably contain a core (first stage) of ate), or PET, and . rubbery poly(alkyl ) polymer or Desirably, such polymers balance melt-rheology 30 which is optionally crosslinked and/or graftlinked, and properties such as flow and sag: the polymer must flow a thermoplastic hard shell (outer stage) preferably of readily enough to be extruded, injection molded or poly() polymer or copolymer, as otherwise formed into the parison; it must be suffi taught by Farnham et al., U.S. Pat. No. 4,096,202. ciently elastic and thermoplastic to fill the final mold Other impact modifying polymers are methacrylate readily under air pressure and heat, and without melt 35 butadiene-styrene resins, which are multi-stage poly fracture or other surface distortion; yet it must be suffi mers having abutadiene polymer or copolymer, option ciently resistant to flow or sag while cooling that the ally containing vinylaromatics, as for examples styren shape of the finished article is retained. ics, (meth)acrylate , or (meth)acrylonitrile, at lev Further, if the polymer may be crystallized, the vari els below 30% and optional crosslinking, as a first stage. ous processing, blending, and forming operations to One or more thermoplastic methyl methacrylate poly which it is subjected must not accelerate crystallization mer stages containing styrene, lower alkyl (meth)acry to the point that blow-molding properties are degraded. lates and/or (meth)acrylonitrile and optionally other This combination of properties is difficult to find in monovinyl, monovinylidene, polyvinyl and/or poly unmodified polymers. Poly(vinyl chloride) may be eas vinylidene components are polymerized onto the first ily modified with polymers that act as processing aids, 45 stage. Such modifiers are useful for impact-property to make a polymer that is tractable in blow-molding modification of polycarbonates and polyesters, and are applications, but other polymers have been more diffi taught by Nakamura et al., U.S. Pat. No. 3,864,428 and cult to modify satisfactorily. Condensation polymers Fromuth et al., U.S. Pat. No. 4,180,494. such as polycarbonates and polyamides and relatively Such staged polymers are preferably made by emul low-molecular weight polymers such as 50 sion polymerization and isolated by any of several tech terephthalate of molecular weights in the range below niques known to those skilled in the art, including coag about 20,000 have been difficult to modify for blow ulation, spray drying or other evaporative techniques molding, and polycarbonate resins have proved espe such as extruder coagulation with dewatering and pel cially difficult. letization as taught by Bortnick in U.S. Pat. No. One approach that has been used to improve the 55 3,751,527. These impact-property-modifying polymers blow-molding properties of polycarbonate resins has may be stabilized with additives during isolation and been to introduce chain branching into the polycarbon may be further treated, as by partial fusing or pelletiza ate molecule, as taught by Hedges et al. in U.S. Pat. No. tion, for ease of handling or blending. Blends of poly(- 4,415,723. Another has-been to copolymerize the poly methyl methacrylate) with poly(ethylene terephthalate) carbonate with a polyester, as taught by Belfoure in 60 are also taught for blow molding of bottles by Japanese European Patent Application 155,989. Neither of these Kokai 55-90921, 57-18221, and 57-6727; these teachings approaches has been entirely successful; particular would not encourage one to depart from the relatively properties are improved, but the balance of properties low molecular weights disclosed for the impact modifi important to blow molding is not sufficiently improved. eS. Branching or increasing the molecular weight of the 65 High-molecular-weight polymers have been added to polymer have been applied to other polymers used in various polymers, as for instance the Boutillier et al. blow molding. Branching is taught for poly(ethylene addition of high-molecular-weight styrene to thermo terephthalate) by Edelman et al. in U.S. Pat. No. as a foaming-process aid (U.S. Pat. 5,352,500 3 4. No. 3.903,023). Eichenauer et al., in U.S. Pat. No. to those skilled in the art. The emulsifier may be se 4,622,363, disclose the use of high-molecular-weight lected from among those known to be useful in poly copolymers of styrene with a minor amount of a nitrile merizations; preferred are those which do not degrade or (meth)acrylic , in combination with low the color or stability of the polymer or of the resin to molecular-weight copolymers of styrene with nitrile or 5 which it is added. Typical of emulsifiers for emulsion (meth)acrylic ester and graft polymers of styrene polymerization are alkali metal and ammonium salts of methyl methacrylate on a rubbery polymer, for the fatty carboxylic acids, such as sodium oleate or sodium purpose of raising the softening temperature of polycar stearate; salts of disproportionated rosin acids; ethoxyl bonate resins. ated and/or propoxylated alkyl phenols, such as dode An object of the present invention is to provide a 10 cyl phenol with 1-100 ethylene oxide units; salts of process for improving the rheological properties of aliphatic or aromatic sulfates such as sodium lauryl thermoplastic polymer melts, and particularly the blow sulfate; salts of aliphatic or aromatic sulfonates, such as molding properties of such melts. A further object is to sodium dodecylbenzene sulfonate; sodium or potassium provide a polymeric additive which improves these or ammonium dialkylsulfosuccinates; disodium salts of rheological properties. Additional objects will be ap- 15 mono- or dialkylated diphenylether disulfonates; parent from the disclosure below. C12-C18 alkylsulfonates, sulfates, sulfonates, phos THE INVENTION phates, or phosphonates based on alkylene oxide ad I have discovered high-molecular-weight homopoly ducts of alkylated phenols, such as sodium alkylphenol mers or copolymers of acrylic monomers having mini- 20 (ethylene oxide)1-100 phosphate; and many others mumweight-average molecular weights of 500,000, and known to the art. Combinations of emulsifiers may be preferably of about 1,500,000, which impart a particu employed. Preferred are those with sufficient thermal larly advantageous balance of melt-theology properties stability that their residues in the isolated acrylic addi for various uses, including blow molding, making ex tive can be processed into the matrix resin without truded articles and thermoformable sheet, and making 25 deleterious effects on color or stability; such emulsifiers thermoformed articles therefrom, to certain thermo include alkyl, aryl aralkyl, and alkaryl sulfonates, and plastic polymers and copolymers; preferred are poly alkyl, aryl aralkyl, and alkaryl phosphonates. Such an carbonate resins, polyester resins and blends of polycar emulsion polymerization allows the preparation of pol bonate with polyester. ymer particles having small size, narrow size distribu tion and high molecular weight, quickly and at high DESCRIPTION OF THE INVENTION 3O conversions, with minimum residual monomers. One The melt-rheology-modifying (MRM) polymers of process by which polymers of the preferred molecular the present invention are prepared by free-radical poly weights may be made is taught by Kotani et al. in U.S. merization of acrylic monomers to minimum molecular Pat. No. 4,201,848, and other processes are known to weights of about 500,000, and preferably of about 35 those skilled in the art. The polymer may be easily 1,500,000. At least 50%, and more preferably at least isolated from the reaction mixture using known tech 70%, by weight, of the polymers comprises polymer niques. units from an acrylic having the formula The minimum weight-average molecular weight (M) of the FIRM polymers of the present invention, as Rl 40 measured by gel permeation chromatography (GPC) techniques, is preferably about 500,000, more preferably CH2=C-C-O-R2 about 1,500,000, and still more preferably about O 3,000,000 (3 x 106). Below these values the contribution of the polymer to the blow-molding properties of the where R1 is H or CH3 and R2 is selected from H, alkyl, 45 resin incorporating it is small, although benefits may be substituted alkyl, cycloalkyl, aryl, aralkyl and alkaryl, recognized from using lower-molecular-weight MRM and is preferably an alkyl group containing 1 to 8 car polymers, as for example those with M of about bons. Especially preferred for R2 are methyl, ethyl and 400,000. Difficulties with preparing extremely high n-butyl, and the especially preferred polymers of the molecular-weight polymers create a practical upper present invention are terpolymers of at least 70% by 50 limit of about ten million for the preferred polymer, weight methyl methacrylate, 0-20% by weight ethyl or although higher molecular weights are contemplated butyl acrylate and 0-30% by weight butyl methacry within the scope of the present invention. The preferred late. As used herein the term (meth) acrylate refers to MRM polymers are linear or branched, but they are not the above formula where R is either H or CH3. crosslinked; that is, they are soluble in organic solvents As a minor component of the MRM polymers, units 55 such as tetrahydrofuran, toluene, ethylene dichloride from other copolymerizable vinyl monomers may be and the like. Within the broader aspect of the invention, selected by those skilled in the art. Included among crosslinked, and especially lightly crosslinked, poly such copolymerizable vinyl monomers are those bear mers are also contemplated. Such crosslinking may be ing functional groups, as for example the carboxylic introduced by the incorporation of units from polye acid groups found in (meth). 60 thylenically unsaturated monomers into the MRM poly The MRM polymers of the present invention may be mer, preferably at levels up to about 5%, and more prepared by any known polymerization techniques, preferably-from about 0.01 to about 0.5%, by weight including bulk, solution, emulsion or suspension poly based on the total MRM polymer weight, or it may be merization. Preferred is conventional emulsion poly introduced by other techniques known to those skilled merization, using thermal, redox or other known initia- 65 in the art, as for example thermal crosslinking or various tion, batch feed or gradual feed, single or multiple post-crosslinking techniques. staged polymerization, seeded polymerization, and simi The MRM polymer of the present invention may be lar variations of this technique which will be apparent isolated from the emulsion in which it is formed by any 5,352,500 5 6 of several methods, including coagulation, evaporation, agents, antioxidants, light stabilizers, heat stabilizers, spray drying, or devolatilizing in an extruder followed and the like. The blends may also contain fillers such as by pelletization. Preferred are spray drying and coagul calcium carbonate, reinforcing agents such as coupled lation. , fibers such as glass fibers, and the like. The matrix resins into which the MRM polymer of 5 Blowing agents include chemical blowing agents, the present invention is incorporated include polycar such as azobiscarbonamides, added to or blended with bonates; polyesters including poly(alkylene terephthal the molten polymeric mixture, followed by processing ates); poly(aromatic ketones) such as polyether ketone, of the molten blend under conditions sufficient to de , polyether ketone ketone, compose the chemical blowing agent prior to exit of the polyketone; poly(phenylene ethers); poly(phenylene O molten polymer from the processing apparatus. Blow sulfides); phenoxy resins; such as poly(e- ing agents also include gaseous blowing agents, such as ther sulfone), poly(aryl sulfone), ; poly(e- nitrogen, added to the molten polymer blend prior to ther imides); poly(ether imide esters); copoly(ether exit of the molten polymer from the processing appara imide esters); poly(ester carbonates); polyarylates such tus. Such chemical or gaseous blowing agents will pro as poly( isophthalate); such as 15 duce a foamed extruded, blow-molded, thermoformable poly(glutarimides); aromatic polyimides; polyacetals; or thermoformed article, depending on the fabrication poly(styrene) including crystal poly(styrene) and high process chosen. By "foamed' is meant an internal impact poly(styrene); polymers of vinyl toluene or para foamed structure with cell sizes sufficient to reduce methyl styrene; copolymers of styrene or alkyl substi weight substantially, but small and uniform enough to tuted styrene with acrylonitrile or maleic anhydride; 20 allow continuous support for load-bearing from the polyamides including crystalline and amorphous poly polymer surrounding the cells. amides; acrylate-styrene-acrylonitrile resins; acryloni A significant use of the resins which incorporate the trile-butadiene-styrene resins; poly(amide imides); ni MRM polymer of the invention is in the preparation of trile resins; poly(methyl pentene); olefin modified sty useful articles by extrusion blow molding, but the en rene-acrylonitrile; styrene-butadiene resins; acryloni 25 hanced melt strength imparted by the MRM polymers trile-chlorinated polyethylene-styrene resins; thermo will also be advantageous in preparing useful articles by plastic such as poly(ether esters), poly(ether processes such as injection blow molding, thermoform amides), poly(styrene butadiene styrenes) and poly(sty ing and stamping processes on polymer sheet, molding rene ethylene-butylene styrenes); and copolymers and of foamed polymers, extrusion of profile, such as blends of the above. Those matrix resins specifically 30 foamed profile, sheet, rods, or tubes, and the like, per listed above shall be indicated herein by the term “ther formed upon resins containing the MRM polymers of moplastic engineering resins.” this invention. The resins which incorporate the MRM Using methods known to those skilled in the art, the polymer will also be advantageous in other applications MRM polymer of the present invention may be incor where high melt strength is a desirable property. Other porated into the matrix resin at from about 1% to about 35 uses will be readily apparent to those skilled in the art. 25% of the total weight of resin plus polymer. Higher Useful articles which may be made from the resins levels may be used within the scope of the present in which incorporate the MRM polymer of the present vention, but may deleteriously affect the balance of invention include items for automotive use, such as other physical properties, such as the heat distortion bumpers, spoiler panels, dashboard panels, rear window temperature, of the resin in specific applications. A 40 panels, external air spoilers, seat backs, truck bed liners, more preferred range is from about 1 to about 10%, and wind deflectors, motorcycle fairings and skirtings and still more preferred is from about 5 to about 10%. The the like. Further uses may include toys, such as tricy MRM polymer may, for example, be incorporated into cles, surfboards, exercise equipment, television hous the resin by blending the MRM polymer, as a dry pow ings, other equipment housings, such as typewriter der or pellets, with a dry powder or pellets of the matrix 45 cases, and the like. Still further uses include containers resin. Alternatively, if the matrix resin and the MRM such as bottles, tanks for organic or inorganic liquids, polymer have been separately prepared as emulsions, and the like. The formed materials may be useful in the emulsions may be mixed and isolated as an intimate buildings, such as decorative or tough protective pan mixture by conventional methods such as coagulation els, thermoformed panels, seating construction, pipe, or spray drying, or as yet another alternative, the emul 50 profiled shapes for window and door construction and sions may be isolated separately and sequentially in the the like. Foamed articles such as sheet, rods, tubes, and same equipment, this process being termed 'staged especially profile will be useful where the shape reten coagulation.” As a less preferred method, the mono tion and load-bearing properties of the engineering resin mers used to prepare the MRM polymer may be poly are maintained but with a lighter weight construction; merized in the presence of the matrix polymer, but the 55 such uses will include panels, equipment housing, win polymerization conditions must be carefully controlled, dow and door frames, toys, automotive uses, athletic or the molecular weight of the resulting polymer will be equipment, and the like. Many other uses for such too low to be fully effective. tough, heat resistant, readily blow-molded, thermo Other additives may be incorporated into the matrix formed or otherwise processed having high resin prior or subsequent to incorporation of the poly melt strength will be readily apparent to those skilled in mer of the present invention, or they may be incorpo the art. rated simultaneously, as by coagulating or spray drying All percentages and ratios given herein are by mixed emulsions of the MRM polymer and the addi weight, unless otherwise stated, and all reagents are of tives, and incorporating the resulting material into the good commercial quality unless otherwise stated. matrix resin. Such procedures are conventional, and 65 Physical-property tests performed on the matrix pol will be readily apparent to those skilled in the art. ymers containing the MRM polymers of the present These additives may include other polymers useful as invention include melt viscosity, melt creep rate, extru impact modifiers, lubricants, flame retardants, blowing sion sag time, modulus and impact resistance. Melt vis 5,352,500 7 8 cosity was determined for the samples using a Rheomet while 100.4 g methyl methacrylate, 63.8gethyl acrylate rics "Dynamic Spectrometer” in the parallel-plate mode. A sample with a radius of 12.5 mm and approxi and 18.2 g n-butyl methacrylate were added; the mono mately 2 mm thick was placed between the plates, and mers were rinsed into the vessel with an additional 10 dynamic torsional shear was applied to the sample at a 5 ml of water. A mixture of 0.231 g sodium formaldehyde rate of 100 radians/sec as the sample temperature was sulfoxylate in 25 ml water was added to the vessel, raised. The temperature at which the sample viscosity followed by 0.33 g t-butyl hydroperoxide (70% active) at that shear rate reached 20,000 poise was taken as the as an initiator. Polymerization was evidenced by a rise "process temperature'. The sample was then held at the in temperature of the vessel contents, beginning about process temperature and the shear rate was reduced to O two minutes after the initiation was added, with a peak 1 radian/second. The melt viscosity was measured at the lower shear rate, and the dynamic melt-strength temperature of about 65-70° C. The vessel contents parameter, R', was determined by dividing the mea were then cooled to 50° C. by adding 130 ml water. An sured melt viscosity at the lower shear rate by the additional 12.2 g emulsifier were rinsed into the reactor 20,000-poise value obtained at the higher shear rate. 15 with 5 ml water, and 481.1 g methyl methacrylate, 32.8 Melt creep rate (MCR) was measured using a Rheo g ethyl acrylate and 32.8 g. n-butyl methacrylate were metrics "Stress Rheometer' A sample with a radius of added and rinsed into the vessel with 20 ml water. The 12.5 mm and a thickness of 1 mm was placed between temperature was adjusted to 35° C. and the nitrogen the parallel plates of the instrument. A constant shear sweep was discontinued. A mixture of 0,219 g sodium load of 3x10' dynes/cm2 applied to the sample at the 20 formaldehyde sulfoxylate in 20 ml water was added, process temperature determined above, and the angle, in radians, through which the loaded plate moved with followed by 0.39 g t-butyl hydroperoxide. After the respect to the fixed plate was measured. The strain was exotherm peak, the vessel was cooled to room tempera calculated by multiplying the angle by the radius of the ture, and a latex having 50.5% solids was removed from sample disk and dividing the sample thickeners. The 25 the vessel. MCR was then determined by dividing the strain by the time over which the strain was measured. MCR units EXAMPLES 2-7 are sec-1. These examples show the modification of blow-mold Extrusion sag time was determined by horizontally ing-related physical properties of polymer blends that extruding a strand of polymer from a Killion 25-mm simulate commercial blow-molding resins. extruder operating at a rate of 60 rpm, through the specified die at the specified temperature. The time for The latex from Example 1 was isolated by spray dry the strand to sag to a point 1.00 meter below the die was ing, and melt blended at various levels, in a 25 mm recorded in seconds, Killion extruder at 249 C., into a stabilized, 43/57 blend Tensile modulus was measured according to ASTM 35 of poly(butylene terephthalate) (PBT) having an intrin Standard Method D-638. Impact resistance was mea sic viscosity, measured in 60/40 phenol/tetrachloroe sured using a notched Izod impact sample according to thane, of 1.1 dl/g at 25 C., with branched aromatic ASTM Standard Method No. D-256. Both number polycarbonate as described in U.S. Pat. No. 4,001,184, average and weight-average molecular weights (Mn and having an intrinsic viscosity, measured in methylene M.) were determined by gel-permeation chromatogra 40 phy, using a poly(methyl methacrylate) reference. The chloride, of 0.5dl/g at 25 C., and marketed by General following abbreviations are used to indicate monomer Electric Company as Lexan 151 (PC), containing 18% components of the polymers in the following examples: (based on the PBT --PC weight) core-shell impact MMA - Methyl Methacrylate modifier having a core (77.5 parts) polymerized from 71 EA - Ethyl Acrylate 45 parts butadiene, 3 parts styrene, 4 parts methyl methac BA - n-Butyl Acrylate rylate and 1 part divinylbenzene; a second stage poly BMA - n-Butyl Methacrylate merized from 11 parts styrene; and a shell polymerized In the examples and elsewhere in the specification from 11 parts methyl methacrylate and 0.1 parts 1.3- and claims, all ratios and percentages are by weight butylene glycol dimethacrylate. Impact resistance, unless otherwise indicated, and all reagents are of good 50 commercial quality unless otherwise indicated. In all modulus, extrusion sag time, melt creep rate and the emulsion preparations, the water used is deionized wa dynamic melt-strength parameter, R', described above, ter. were determined for these blends, and are shown in The following examples are intended to illustrate the Table I as Examples 2-4. invention. 55 The isolated latex was similarly blended at various levels into a stabilized, 75/25 blend of co-polyester EXAMPLE 1. polycarbonate made according to Belfoure, European This example illustrates the preparation of a high Patent Application 155,989 with stabilized poly(ethy molecular-weight acrylic MRM polymer of the present lene terephthalate) containing 18% (based on the co invention having an overall composition MMA/EA/B- 60 polyester-polycarbonate weight) core-shell impact MA=79.8/13.2/7.0, and molecular weights of Mw = 4x 106 and M= 1 x 106. modifier having core of rubbery crosslinked poly(n- To a 3-neck, 5-liter flask equipped with a stirrer, butyl acrylate, and graftlinked thereto, an outer, rigid reflux condenser and nitrogen sweep was added 455g shell of methyl methacrylate. Similar physical property water, 0.16 g glacial acetic acid, 0.78g sodium chloride 65 measurements were made for these blends and are and 4 g of emulsifier; the emulsifier was rinsed into the shown in Table I as Examples 5-7; extrusion sag time vessel with an additional 35 ml of water. The contents was determined using a barrel temperature of 249 C. of the vessel were adjusted to, and maintained at, 30° C. and a 3.18 mm die. 5,352,500 9 10 TABLE I tion, and Process III indicates a two-stage, redox emul MRM sion polymerization. Extrusion sag time was determined Polymer Notched as described above, using an extruder speed of 60 rpm, of Exam- Izod Tensile Extrusion a barrel temperature of 249 C. and a 1.59-mm die. The Exam- ple 1, (joules/ Modulus MCR Sag Time 5 result are shown in Table II below: ple (wt.%) cm) (kPa) R* Sec-1 SeC. 2 0 7.74 2210 7.8 0.091 20 TABLE II 3 3 8.01 2217 100 0.037 29 Composition Extrusion 4. 5 7.90 2204 11.1 0.029 34 Exam- (MMA/EA/BA/ Prepared My Sag Time 5 O 5.71 188 4.9 0.13 27 ple BMA) (Ratio) by Process (x109) (sec) R+ 6 3 6.30 118 5.4 0.09 40 10 7 5 5.82 1167 5.8 0.06 44 9 99/1/0/0 III 2.7 15.3 9.6 10 99//0/0 II 2.7 10.7 9.9 1 99/1/0/0 III 1.6 11.5 10.3 As may be seen from the above table, the physical 12 79/13/0/3 I 4.1 12.6 9.7 properties, such as the notched Izod impact values and 13 79/13/0/3 I 7.5 17.7 9.8 15 14 7.5/1/0/24 III 2.9 14.5 9.6 the tensile modulus, of the resins were unchanged by 15 75/1/0/24 I 3.3 14.5 10.3 the addition of the MRM polymer, but the melt 16 100/0/0/0 3. 14.2 9.8 rheology properties, such as the melt creep rate, R and 17 86/0/7/7 2.5 10.9 10.6 extrusion sag time, were significantly improved. 18 Matrix Resin - 7.6 7.0 EXAMPLE 8 20 This example illustrates preparation of blow-molding EXAMPLES 19-23 parisons from the blends of Examples 2 and 4 above, In the following examples high-molecular-weight and the higher melt strength obtainable with the blends methyl methacrylate/ethyl acrylate/butyl methacrylate containing the MRM polymer of the present invention. MRM polymers of the present invention were blended The blow-molding equipment used in this example was 25 at a level of 5% with the resin of Examples 2-4. The a 3.2 kg Sterling blow-molding machine with a 3.2-kg composition of the MRM polymers, weight-average capacity accumulator head, and controlled by a Maco 8000 process control system. The accumulator was fed molecular weight, rheological parameter R', melt with an 8.9 cm extruder equipped with a single Sterling creep rate (MCR) and extrusion sag time at a 249 C. barrier-type screw. The parison die was a 35.5-cm 30 barrel temperature using a 1.59-ram die are shown in diameter, annular die with a programmed gap width set Table III, below: to produce nominal 2.5-mm parison wall thickness. The TABLE III blended polymer was pelletized, the pellets were fed to Compositions Extrusion the single-screw extruder and extruded into the accu (MMA/EA/ M MCR Sag Time mulator; when the accumulator was full, the polymer 35 Example BMA (Ratio) (x10) R* (sec-1) (sec) melt at 249 C. was forced through the die to form a 19 75/1/24 4.1 9.7 0.04 12.3 122-cm-long parison. The polymer of Example 4 pro 20 73/3/24 4.5 9.5 0.06 12.8 21 89/1/10 3.5 10.1 0.06 1.5 duced a short parison, about half the length of that from 22 87/3/10 3.2 10.6 0.05 1.6 an equal weight of the control polymer of Example 2, 23 79.8/7/13.2 4.2 10.2 0.08 12. indicative of thicker walls caused by a higher melt strength for polymer containing the MRM polymer. To obtain a parison of comparable length and wall thick EXAMPLES 24-27 ness, the die gap for the polymer of Example 4 was decreased. Parison hang time for the similar-sized pari In the following examples, high-molecular-weight sons was taken as the time for the bottom of the parison 45 methyl methacrylate/butyl acrylate/butyl methacrylate to sag to the floor, 1.0 meters below the bottom of the polymers of the present invention were blended at a parison as formed. The hang time for the parison made level of 5% with the resin of Examples 2-4. The blends from the control polymer of Example 2 was 2.5 sec were tested as in Examples 19-23, and the results are onds, and the parison sagged to the floor, with consider shown in Table IV, below: able narrowing at the top, while the hang time for the 50 TABLE IV parison made from the resin of Example 4 was 6.2 sec Compositions onds at the same temperature and 3.7 seconds at 260 C.; (MMA/EA/BMA M MCR Extrusion both of the parisons made from the resin of Example 4 Example Ratio) (x108) R* (sec-1) Sag Time broke away near the die, after essentially no narrowing 24 74.7/1.3/24 4.7 10.5 0.04 12.8 at the top, and fell to the floor. 55 25 72.2/3.8/24 4.6 10.3 0.05 2.7 26 88.7/1.3/10 3.2 10.6 0.07 i.7 EXAMPLES 9-18 27 86.2/3.8/10 3.2 10.4 0.07 11.3 The following examples illustrate that high-molecu lar-weight acrylic MRM polymers of the present inven tion having various compositions are effective in im 60 EXAMPLES 28-36 proving the blow-molding-related theological property These examples illustrate the effect of functional of extrusion sag time when blended into the resin of monomers, when incorporated into the MRM polymers Examples 2-4 at a level of 5%. The MRM polymers of of the present invention, upon physical properties of the present invention used in these examples have the blends of the polymers with the resin of Examples 2-4. compositions and molecular weights indicated in Table 65 Functional monomers used include maleic anhydride II. The processes by which they were prepared are as (MAH), methacrylic acid (MAA), diallyl maleate follows: Process I is the process of Example 1, Process (DALM) and butylene glycol dimethacrylate II indicates a multi-step, thermal emulsion polymeriza (BGDMA), and the polymers were prepared using a 5,352,500 11 12 two-stage redox emulsion polymerization. The compo branched polycarbonate (PC) is that described in Exam sitions of the MRM polymers were as follows: ples 2-4 as a component of the blended polycarbonate MRM. Polymer A polyester resin. The MRM polymer was that of Exam MMA/BMA/EA/MAH=70/24/1/5 ple 1 and had molecular weight of 4.1 x 106, and the impact modifier was the core-shell impact modifier MRM Polymer B described in Examples 5-7. The extrusion sag time was MMA/BMA/EA/DALMs 72.8/24/3/0.2 measured as described above, using an extruder speed of MRM Polymer C 60 rpm, a barrel temperature of 266° C. and a 1.59-mm die. The results are shown in Table VII. MMAABMA/EA/DALM=80.9/17/2/0.1 10 MRM Polymer D TABLE VII MMA/BMA/EA/DALMs 88.8/10/1/0.2 Impact Acrylic Extrusion Branched Modifier Polymer Sag Time MRM Polymer E Example PC (%) (%) (%) (sec) MMA/BA/DALM//MMA/BGE)- 15 MAs 78.24/1.6/1.6//fg.8/0.2 40 100.0 0.0 0.0 8.4 4. 90.0 10.0 0.0 8.0 42 85.0 10.0 5.0 13.5 Properties measured were extrusion sag time, the theological parameter (R') and melt creep rate (MCR). The extrusion sag time was determined as described above, using an extruder speed of 60 rpm, a barrel tem EXAMPLES 43-50 perature of 249 C. and a 1.59-ram die. The results are These examples show the improvement of the blow shown in Table V. molding-related property, extrusion sag time, as the TABLE V level of an MRM polymer of the present invention is MRM MRM Extrusion 25 increased in a resin similar to that of Examples 2-4. In Polymer, Polymer Sag Time MCR these examples the amount of impact modifier of Exam Example Level (%) M(x10°) (sec) R* (sec-1) ples 2-4 was held constant, and the high-molecular 28 O ---- 7.3 6.7 - weight acrylic MRM polymer, made using a two-stage, 29 A, 5% 0.73 9.6 9.9 - redox emulsion polymerization and having a molecular 30 O - 7.8 7.1 0.090 31 B, 5% Note 11.0 100 0.040 30 weight of 4.3x 106 and a composition of 72.16% 32 C, 5% 3.7 11.5 10.3 0.034 MMA/3.84% EA/24% BMA, replaced a portion of the 33 D, 5% Note 11.5 10.0 0.036 polycarbonate-poly (butylene terephthalate) (PC-PBT) 34 O ------7.1 0.090 35 E, 3% Note - 8.5 0.039 in the blend, to the extent indicated below in Table 36 E, 5% Note --- 12.7 0.030 VIII. Extrusion sag time was measured as described Note: 35 above, using an extruder speed of 60 rpm, a barrel tem The molecular weight for these polymers could not be determined, because they were insoluble in tetrahydrofuran. perature of 249 C. and a 1.59-ram die. TABLE VIII Impact Acrylic Extrusion EXAMPLES 37-39 PC-PBT Modifier Polymer Sag Time These examples illustrate the improvement of extru Example (%) (%) (%) (sec) sion sag time as the level of an MRM polymer of the 43 85.0 15.0 0.0 7.8 present invention is increased in a branched polycar 44 84.0 15.0 1.0 9.9 bonate (PC). The MRM polymer was prepared using a 45 82.0 15.0 3.0 12.0 46 80.0 15.0 5.0 14.3 two-stage, redox emulsion polymerization and has a 45 47 78.0 5.0 70 15.3 molecular weight of 4.6x 106 and the composition 48 75.0 15.0 10.0 17.2 72.16% MMA/24% BMA/3.84% BA, and the 49 700 15.0 15.0 19.4 branched polycarbonate is that described in Examples 50 65.0 15.0 200 22.5 2-4 as a component of the blended polycarbonate polyester resin. The extrusion sag time was determined 50 as described above, using an extruder speed of 60 rpm, EXAMPLES 51-53 a barrel temperature of 266 C. and a 3.18-mm die. The These examples show the improvement of extrusion results are shown in Table VI, below. sag time as the level of a MRM polymer of the present TABLE VI invention is increased in an unmodified, linear polycar Branched Acrylic Extrusion 55 bonate (PC). The MRM polymer was made using a Example PC (%) Polymer (%) Sag Time (sec) two-stage redox emulsion polymerization and had a 37 100.0 0.0 10.5 38 95.0 5.0 15.0 composition of 72.16% MMA/24% BMA/38.4% BA, 39 90.0 10.0 20.1 and a molecular weight of 4.6x 106. The extrusion sag time was determined as described above, using an ex truder speed of 60 rpm, a barrel temperature of 266 C. EXAMPLES 40-42 and a 1.59-mm die. The results are shown in Table IX, These examples illustrate that inclusion of a conven below. tional impact modifier into a branched polycarbonate TABLE IX fails to improve its extrusion sag time, and in fact de 65 Linear Acrylic Extrusion creases it slightly, while addition of the high-molecular Example PC (%) Polymer (%) Sag Time (sec) weight acrylic MRM polymer of the present invention 51 00.0 0.0 3.3 substantially improves the extrusion sag time. The 52 95.0 5.0 5.2 5,352,500 13 14 TABLE IX-continued The MRM polymer of the present invention was that Linear Acrylic Extrusion described in Examples 51-53. Example PC (%) Polymer (%) Sag Time (sec) The initial extrusion blending was carried out in a 6/35-cm Prodex extruder; the extruded, pelletized 53 90.0 10.0 7.1 5 blends were then extruded into sheets and cut to 43-cm by 91-cm tests sheets with a thickness of 1.6 to 2.0 mm. The sheets were hung by one edge in an oven at EXAMPLES 54-59 175-190° C. to soften them for thermoforming. The These examples illustrate the effect on extrusion sag sheets of blend without the MRM polymer were ob time of additional thermoplastic engineering resins 10 served to fall to the oven floor if allowed to remain at when the high-molecular-weight acrylic MRM poly the thermoforming temperature for longer necessary mers of the present invention are incorporated in them. for handling, while the sheets of blends containing the In the following table, the resins listed are S/AN, a MRM polymer had sufficient melt strength to hang in Poly(styrene-acrylonitrile) resin marketed by Monsanto place for long periods. Using the Rheometrics Dynamic as Lustran SAN-35; S/MAH, a poly(styrene-maleic 15 Spectrometer described above in the oscillating paral anhydride) resin marketed by Arco as Dylark 332; lel-plate mode, the theology of the two blends was polyarylate, an aromatic polyester resin marketed by determined at 15% strain during a 260 C-205 C. tem Union Carbide as Ardel D-240; PEI, as poly(ether perature sweep; the oscillation frequency was 1 hr. The imide) resin marketed by General Electric Company as contributions of elastic (G) and viscous (G') rheology Ultem 1000; Nylon-6 a poly(caprolactam) marketed as 20 components to the complex viscosity of the blend are Capron 8202 by Allied Chemical and PBT, a poly(buty shown in Table XI. lene terephthalate) resin having an intrinsic viscosity TABLE X measured in 60/40 phenol/tetrachloroethane of 1.1 dl/g Rheology Component Example 60 Example 61 at 25 C. and marketed by General Electric Company as 25 (G) elastic (dynes/cm) 9.6 x 105 1.2 x 106 Valox 315. The acrylic polymers were blended into the (G') viscous (dynes/cm) 8.9 x 105 1.1 x 106 thermoplastic resins using a 25-mm Killion single-screw Complex viscosity (poise) 1.3 x 106 6.6 x 106 extruder at the indicated barrel temperatures. Extrusion sag time was also measured at the indicated barrel tem peratures using a 3.18-mm die and the procedure de- 30 EXAMPLES 62-63 scribed above. The results are shown in Table X. These examples illustrate improvement in sag flow TABLE X time imparted to a commercial acrylonitrile-butadiene Acrylic Blend. Thermo- Barrel Extrusion styrene (ABS) polymer by a high molecular weight Exam- Polymer M, x Level Plastic Temp Sag time MRM polymer. The MRM polymer was made by a ple (1) 106 (2) Resin (°C) (sec) 35 two-stage redox process as discussed in Examples 9-18, 54A A 4.6 10 S/AN 360 48.2 Process Type III. It had a molecular weight of approxi 54B - O S/AN 360 22.6 mately 4.1 x 106 and a composition of (MMA/BMA/- 55A A. 4.6 10 S/MAH 425 43.5 BA)//(Styrene/BMA/EA), (20/77/3)//(47/50/3), the 55B - O S/MAH 425 9.9 56A A 4.6 10 Polyary- 500 10.3 40 stages being in a 35//65 ratio. The ABS polymer was late supplied by (or obtained from) Borg-Warner as Cy 56B - 0. Polyary- 500 4.7 clolac HIL-1000; it is believed to be a blend of late styrene/acrylonitrile copolymer with a graft polymer 57A A 4.6 10 PEI 600 11.5 57B - O PEI 600 6.5 of styrene/acrylonitrile onto a poly(butadiene) rubber. 58A 4.9 5 Nylon-6 450 16.8 Extrusion sag was measured as in Examples 54-59, with 58B - 0 Nylon-6 450 is 45 a 1.59-mm die and a barrel temperature of 232 C. The 59A B 4.9 10 PBT 480 10.5 extrusion sag time for the control with no MRM addi 59B - O PBT 480 5.2 tive (Example 62) was 11.3 seconds; for the blend with Polymer A has the composition 72.16% MMA/24% BMA/3.84% BA 10 wt % of the MRM (Example 63), the sag time was Polymer B has the composition 74% MMA/24% BMA/2% MAA Level of the acrylic polymer in the resin blend 50 21.4 seconds. EXAMPLES 64-70 EXAMPLES 60-61 In these examples are shown the improvements in extrusion sag time when acrylic MRM polymers were These examples illustrate the preparation and testing added to a commercial blend believed to contain poly(- of thermoformable sheet from thermoplastic engineer-ss phenylene ether) //high impact polystyrene, known as ing resins containing the MRM polymers of the present Noryl PX-1222 (General Electric). The MRM poly invention. mers were made by the two-stage process similar to By a process similar to that of Examples 2-4 blends those in Example 9. In two cases, a commercial metha were prepared having the following compositions: crylate-butadiene-styrene 20 polymer, Paraloid KM 653 (Rohm and Haas Company, Philadelphia, Pa.), Example 60 Example 61 prepared by the process of U.S. Pat. No. 3,985,704 was PBT of Examples 2-4 34.00% 34.00% utilized. The molecular weight of the soluble meth PC of Examples 2-4 44.75% 39.75% acrylic polymer extracted from this modifier was below Impact Modifier of 20.00% 20.00% 500,000; the remainder of the modifier was highly cross Examples 2-4 65 linked and insoluble in organic solvents. Processing and Stabilizers 1.25% 1.25% testing for sag was measured as in Examples 54-59, with MRM Polymer 0.00% 5.00% a 1.59-mm die at a barrel temperature of 232 C. The results are shown in Table XII. 5,352,500 15 16 TABLE XII min. The foamed extrudate had acceptable strength and Noryl, KM-653, MRM, Extrusion sag surface. A control without the MRM processed in a Example parts parts parts time, seconds similar manner (Example 72) had poorer strength and 64 500 w 5.2 surface, and had expanded to a diameter of 8.8 mm. 6S 450 A, 50 21.2 What is claimed is: 66 450 -war B, 50 20.2 1. A blow-molded article formed from a polymer 67 450 C, 50 25.4 68 475 25 5.4 blend which comprises a thermoplastic engineering 69 475 C, 25 15.7 resin and blended therewith from about 1 to about 25%, 70 450 25 C, 25 21.7 based on the total weight of the blend, of a methacrylic 10 Modifier A: StABMA/BA//StABMA/BA is 20/77/3//47/50/3. ester polymer of units of one or more copolymerizable Modifier B: StABMA/BAA/MMA/BMAABA = 20/77/3//47/50/3. Modifier C: MMA/BMAABAAAStABMA/BA = 20/77/3//47/50/3, vinyl monomers, wherein at least 70% by weight of the The stage ratio in all modifiers was 35//65. units have the formula. 2. The blow-molded article of claim 1 wherein the article is formed by extrusion blow molding. EXAMPLES 71-72 15 3. The blow-molded article of claim 1 wherein the These examples illustrate the ability of a MRM to article is formed by injection blow molding. enhance the melt strength of a resin sufficient to form 4. The blow-molded article of claim 1 wherein the foam of acceptable cell size and load-bearing strength. article is a container. A blend of the modifier of Example 27 (10 parts per 5. The blow-molded article of claim 1 wherein the hundred parts of matrix) with the matrix blend of poly 20 article is an automotive bumper. carbonate/poly(butylene terephthalate)/MBS impact 6. The blow-molded article of claim 1 wherein the modifier of Examples 2-4 was prepared; the blend also article is an automotive body panel. contained 1 part of azodicarbonamide, a chemical blow 7. The blow-molded article of claim 1 wherein the ing agent. The blend was processed in a Haake Rheo 25 article is an architectural wall panel. cord mixer at a melt temperature of 247 C. at 60 rpm 8. The blow-molded article of claim 42 wherein the and extruded through a 6.35-mm die. On exiting the die, article is formed with an internal foamed structure. the strand (Example 71) foamed to a diameter of 10.4 k

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65 UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. : 5,352,500 Page 1 of 2 DATED : October 4, 1994 INVENTOR(S) : Nazir A. Memon It is certified that error appears in the above-indentified patent and that said Letters Patent is hereby corrected as shown below:

Column 4, Line 38; "FRM" should read MRM in the Claims - Column 16, Line 6 should read: Claim 1. A blow-molded article formed from a polymer blend which comprises athermoplastic engineering resin and blended therewith from about 1 to about 25%, based on the total weight of the blend, of a methacrylic ester polymer of units of one or more copolymerizable vinyl monomers, wherein at least 70% by weight of the units have the formula R CH, = C--O-R O wherein R1 is CH3, and R2 is selected from the group consisting of methyl, ethyl, and n-butyl, and having a minimum weight-average molecular weight of about 1,500,000.

UNITED STATES PATENT ANDTRADEMARK OFFICE CERTIFICATE OF CORRECTION

PATENT NO. : 5,352,500 Page 2 of 2 DATED October 4, 1994 NVENTOR(S) : Nazir A. Memon it is certified that error appears in the above-indentified patent and that said Letters Patent is hereby Corrected as shown below: Column 16, Line 25 should read: Claim 8. The blow-molded article of claim 1 wherein the article is formed with an internal foamed structure.

Signed and Sealed this Twentieth Day of December, 1994 (a teen

BRUCE LEHMAN Attesting Officer Commissioner of Patents and Trademarks