|||||||||||||| USOO5414035A United States Patent (19) 11 Patent Number: 5,414,035 Lindner et al. 45 Date of Patent: May 9, 1995 54 CALENDERED RIGID VINYL POLYMER Rigid PVC Lubrication, David Hurwitz, pp. 349-354 COMPOSITIONS (1973), Society of Plastics Engineers-31st Annual Tech. 75 Inventors: Robert Lindner, N. Wallies, Pa.; Conf. Quebec, Canada. Vincent Clarke, Union, N.J. Recommended Concentrations of A-C Polyethylene Lubricants for PVC Processing (1973) Allied Chem. 73 Assignee: AlliedSignal Inc., Morris Township, A-C Polyethylenes as Lubricants in Vinyl Processing Morris County, N.J. (1984)-Allied Chemical Corp. 21 Appl. No.: 270,078 External lubricants that speed fusion, By Robert Lind ner-Plastics Compounding, Sep./Oct. 1989. 22 Filed: Jul. 1, 1994 Technical Data for Low Molecular Weight Polyethyl I51l Int. Cl. ................................................ C08K 5/57 enes and Derivatives, pp. 2-26 Allied Signal. 52 U.S. Cl. .................................... 524/181; 524/180; Piastics Additives Handbook, Stabilizers, Processing 524/182; 524/310; 524/314; 524/487; 524/490; Aids, Plasticizers, Fillers, Reinforcements, Colorants 524/491; 525/239; 525/240, 525/384; 525/387; for Thermoplastics (1990) p. 468, R. Gachter et al, 525/388 Hanser Publ. ed. 58 Field of Search ............... 524/487, 490, 491, 489, The Use of A-C Polyethylenes In Processing PVC-Al 524/310,314, 178, 180, 181, 182; 525/239, 240, lied Signal Corp. 384, 387, 388 Primary Examiner-Veronica P. Hoke 56 References Cited Attorney, Agent, or Firm--Melanie L. Brown; Roger H. U.S. PATENT DOCUMENTS Criss 4,040,997 8/1977 Vunno et al. ....................... 524/1.78 4,132,691 1/1979 Ejk ................... ... 524/1.78 57 ABSTRACT 4,157,990 6/1979 Lindner et al. .. ... 524/314 The present invention provides an external lubricant 4,203,880 5/1980 Stoloff et al. .... ... 525/214 composition for calendered vinyl polymer. The external 4,218,353 8/1980 Kim .............. ... 06/270 lubricant provides rigid vinyl polymer compositions 4,332,702 6/1982 Lindner ... ... 524/1.78 4,336,176 6/1982 Lindner ....... ... 524/30 having improved plate out resistance, clarity, release, 4,518,732 5/1985 Bussing et al. ...... ... 524/78 and stability. The external lubricant comprises an effec 5,002,989 3/1991 Naumovitz et al. ... 524/487 tive amount for lubricating vinyl polymer of polyethyl 5,232,967 8/1993 Worschech et al. ................ 524/314 ene having a Brookfield viscosity at a temperature of OTHER PUBLICATIONS 150° C. of greater than about 85,000 centipoises and an acid number as determined by standardized titration of Waxes as Lubricants. In Plastics Processing, Luenther KOH of between about 5 and about 9. Illmann SPE Journal pp. 71-77 (1967). Characterization of Lubricants for Polyvinyl Chlorde, Sheets of the calendered vinyl polymer are used for L. King and F. Noel, Polymer Engineering and Sci blister packs and credit cards. ence, (1972), vol. 12, No. 2 pp. 112-119. The Use of Low Molecular Weight Polyethylene in 20 Claims, No Drawings 5,414,035 1 2 Plastics by AlliedSignal Inc. (1973) which teaches that CALENDERED RIGD WNYL POLYMER A-C(R) 392A (high density oxidized polyethylene wax COMPOSITIONS having an acid number of 30) is useful for tin stabilized polyvinyl chloride. See also Technical Data on A-C(R) The present invention relates to calendered rigid Polyethylenes for Plastics by Allied (1984) which vinyl polymer compositions. teaches that A-C(R) 31 6A (high density oxidized poly ethylene wax having an acid number of 16) or A-C(R) BACKGROUND OF THE INVENTION 330 (high density oxidized polyethylene wax having an Rigid vinyl polymer compositions, such as polyvinyl acid number of 30) is useful for tin stabilized calendered chloride compositions, are utilized for producing a vari 10 polyvinyl chloride. ety of structural articles such as plastic pipe, siding, U.S. Pat. No. 4,203,880 discloses tin stabilized polyvi containers, and sheets. These rigid compositions are nyl chloride having a lubricant package comprising substantially unplasticized. Sheets are typically made by oxidized polyethylene wax having an acid number calendering which involves passing the material be greater than 5 and a melt viscosity of 1,000 to 60,000 tween rollers, Because the resulting sheets are typically 15 used for blister packs and credit cards, a very clear final centipoises at 140 C. and a known external lubricant product is highly desirable, such as paraffin oils, paraffin waxes, liquid and solid In order to stabilize vinyl polymer against the decom hydrocarbons, unoxidized polyethylene waxes, montan posing influence of heat and light, tin stabilizers includ ester waxes, lead stearate, mineral oil, 12-hydroxys ing organotin stabilizers such as organotin mercaptides tearic acid, ethylene bis-stearamide, and glycol esters of and organotin sulfides are used to stabilize vinyl poly fatty acids that contain 10 to 20 or more carbon atoms. S. It would be desirable to have a calendered vinyl Lubricants are also added to vinyl polymers to facili polymer composition which has improved plate out tate the extrusion or other melt processing of the struc resistance, clarity, release, and stability improved plate tural articles produced, Lubricants are generally classi 25 out resistance compared with currently used calendered fied as external or internal lubricants, An external lubri vinyl polymer compositions. cant provides a lubricating layer between the plastic melt and the metallic surfaces of the processing equip SUMMARY OF THE INVENTION ment. The external lubricant serves to coat the individ We have found a composition which responds to the ual particles of the polymeric resin and inhibits their 30 foregoing need in the art. Surprisingly, we have found adherence to the metallic surfaces. In contrast, an inter an external lubricant composition for vinyl polymer nal lubricant reduces the effective melt viscosity of the wherein the external lubricant provides improved plate vinyl polymer at the processing temperatures in order out resistance, clarity, release, and stability. to improve its flow properties during processing as well Thus, the present invention provides a composition as to promote fusion. An internal lubricant is generally 35 comprising: (a) vinyl polymer; (b) an effective amount needed only for thin extrusions such as films and thin for stabilizing the vinyl polymer of tin stabilizer; and (c) walled pipe. an effective amount for lubricating the vinyl polymer of The suitability of lubricants for vinyl polymer is de polyethylene having a Brookfield viscosity at a temper termined by the type of stabilizer used in the vinyl poly ature of 140°C. of greater than about 85,000 centipoises mer. For example, the PLASTICS ADDITIVE and an acid number as determined by standardized titra HANDBOOK, 3rd Edition (Hanser Publishers 1990) tion of KOH of between about 5 and about 9. If mea teaches that oxidized polyethylene waxes are suitable sured at a temperature of 150° C., the polyethylene has lubricants for tin stabilized polyvinyl chloride sheets. a Brookfield viscosity of about 40,000 to about 60,000 Known tin stabilized rigid polyvinyl chloride calen centipoises. dered sheet formulations include compositions such as: 45 The present invention also provides a calendered sheet comprising: (a) vinyl polymer; (b) an effective amount for stabilizing the vinyl polymer of tin stabi Rigid 4-Cell Resin 100 phr lizer; and (c) an effective amount for lubricating the Organotin Stabilizer 2.0 vinyl polymer of polyethylene having a Brookfield Acrylic Processing Aid 3.0 50 viscosity at a temperature of 140 C. of greater than about 85,000 centipoises and an acid number as deter mined by standardized titration of KOH of between which is disclosed by David Hurwitz, “The Use of Low about 5 and about 9. Molecular Weight Polyethylene in Rigid PVC Lubrica The present composition and calendered sheets made tion', Society of Plastics Engineers, 31st Annual Tech- 5 5 from the present composition advantageously have nical Conference, 349 (May 1973), and improved plate out resistance and light transmittance compared with the known composition having an exter PVC 100 phr nal lubricant of pentaerythritol adipate stearate. Processing Aid 15 Other advantages of the present invention will be Glycerol Mono-Oleate 10 Octyl Sn Stabilizer 1.6 apparent from the following description and attached Impact Modifier 5-10 claims. A-C (R 316 (oxidized homopolymer 0.05-0.3 polyethylene wax, acid number DETALED DESCRIPTION OF THE of 16) PREFERRED EMBODIMENTS Vinyl polymers useful in the present invention in which is disclosed in A-C(R) POLYETHYLENES clude polyvinyl chloride and polymerized forms of FORPVC by AlliedSignal Inc. (1986). See also Techni vinyl acetate, vinyl chloride-vinyl acetate copolymers, cal Data on A-C(R) Polyethylenes and Copolymers for vinylidene halides such as vinylidene chloride vinyl 5,414,035 3. 4 pyridine, vinyl carbazole styrene, vinylbenzene, acrylic to elevated temperatures which results in premature esters such as methyl acrylate, ethyl acrylate, or meth degradation. If too much lubricant is present in the final ylmethacrylate as well as acrylonitrile. The preferred vinyl polymer composition, a condition referred to as vinyl polymer is polyvinyl chloride which includes "plate out” may occur. The excess lubricant rises to the both homopolymers of vinyl chloride and both copoly surface of the vinyl polymer composition and remains in mers and terpolymers of vinyl chloride with comono contact with the heated wall of the extruder, mill, or mers such as vinyl acetate, vinyl formate, alkyl vinyl calendar roll for a sufficient time to become charred. ethers, ethylene, propylene, butylene, vinylidene chlo The char is either carried along with the molten poly ride, alkyl acrylates and methacrylates, alkyl maleates, mer causing discoloration, or the char may form depos and alkyl fumarates. Preferably, at least 80% and more O its along the inner wall or in the die of an extruder, preferably 100% of the monomer to be polymerized thereby altering the shape of the extruded or calendered will be a vinyl chloride monomer.