GB834345A - Process for the production of cellular vinyl chloride resin compositions - Google Patents

Abstract

A process for the production of a cured cellular vinyl chloride resin composition comprises forming a plastisol by mixing 10 to 75 parts by weight of a vinyl chloride resin, 1 to 85 parts by weight of a poly(ethylene glycol) dimethacrylate having the formula <FORM:0834345/IV (a)/1> where n is an integer of between 2 and 14, and 5 to 70 parts by weight of a non-polymerizable plasticizer for each 100 parts by weight of the resin, dimethacrylate and non-polymerizable plasticizer; forming in known manner a cellular structure in the plastisol, and heating to cure the plastisol. The poly(ethylene glycol) dimethacrylates cure concurrently with the vinyl chloride resin cure. Homopolymers or copolymers of vinyl chloride with, for example, vinyl acetate, vinylidene chloride, vinyl bromide, methyl and other acrylates and methacrylates, vinyl ethyl ether, allylidene diacetate, vinyl methyl ketone and acrylonitrile may be used. Suitable plasticizers are di-(2-ethyl-hexyl)-phthalate, tricresyl phosphates, n-butyl benzyl adipate, dioctyl adipates, di-alkyl dihydrophthalates, hexahydrophthalates, isophthalates, polyesters and poly(dibutyl maleate). Additional ingredients may be stabilizers such as sodium 2-ethyl-hexyl tripolyphosphate, dibasic lead stearate, barium and cadmium laurate, dibasic lead phosphate, epoxidized soy bean oil and the diglycidyl ether of diphenylol propane, and titanium dioxide, chrome orange, talc, whiting, foam stabilizers and blowing agents. The cellular structure can be produced by stirring or by dissolving carbon dioxide (gas or solid) and then reducing the pressure. Alternatively a blowing agent such as N,N1-dimethyl-N,N1dinitroso terephthalamide can be used. Increased viscosity of the plastisol before blowing can be produced by adding a polymer such as a copolymer of vinyl acetate with vinyl chloride, ethylene or ethylene oxide. Curing is effected by heating to 145-260 DEG C. in ovens or by radio frequency generators with a curing catalyst such as azo or peroxide compounds. The dimethacrylates may also be partly polymerized separately, before being added to the plastisols. Examples are given.ALSO:A process for the production of a cured cellular vinyl chloride resin composition comprises forming a plastisol by mixing 10 to 75 parts by weight of a vinyl chloride resin, 1 to 85 parts by weight of a poly(ethylene glycol) dimethacrylate having the formula: <FORM:0834345/V/1> where n is an integer of between 2 and 14, and 5 to 70 parts by weight of a non-polymerisable plasticizer for each 100 parts by weight of the resin, dimethacrylate and non-polymerisable placticizer; forming in known manner a cellular structure in the plastisol, and heating to cure the plastisol. The poly(ethylene glycol) dimethacrylates cure concurrently with the vinyl chloride resin cure. Homopolymers or copolymers of vinyl chloride with, for example, vinyl acetate, vinylidene chloride, vinyl bromide, methyl and other acrylates and methacrylates, vinyl ethyl ether, allylidene diacetate, vinyl methyl ketone and acrylonitrile may be used. Suitable plasticizers are di(2-ethyl-hexyl) phthalate, tricresyl phosphates, n-butyl benzyl adipate, dioctyl adipates, di-alkyl dihydrophthalates, hexahydrophthalates, isophthalates, polyesters and poly(dibutyl maleate). Additional ingredients may be stabilizers such as sodium 2-ethyl-hexyl tripolyphosphate, dibasic lead stearate, barium and cadmium laurate, dibasic lead phosphate, expoxidized soy bean oil and the diglycidyl ether of diphenylol propane, and titanium dioxide, chrome orange, talc, whiting, foam stabilizers and blowing agents. The cellular structure can be produced by stirring or by dissolving carbon dioxide (gas or solid) and then reducing the pressure. Alternatively a blowing agent such as N,N1-dimethyl-N,N1-dinitroso terephthalamide can be used. Increased viscosity of the plastisol before blowing can be produced by adding a polymer such as a copolymer of vinyl acetate with vinyl chloride, ethylene or ethylene oxide. Curing is effected by heating to 145 DEG -260 DEG C. in ovens or by radio frequency generators with a curing catalyst such as azo or peroxide compounds. The dimethacrylates may also be partly polymerized separately, before being added to the plastisols. Examples are given.