GB924318A - Light stabilizer mixture for halogen-containing resins - Google Patents

Abstract

A light-stabilizer mixture for halogen-containing resins comprises (i) a phosphite ester <FORM:0924318/IV(a)/1> where R1, R2 and R3 are H or C1-4 organic groups, at least one being an organic group and (ii) a 2-hydroxybenzophenone having an 85% cut off in the ultra-violet region of from 340 to 400m excluding those of the general formula <FORM:0924318/IV(a)/2> where each of m, n, x, y and z is 0 or 1. Extensive lists of possible groups R1, R2 and R3 in the phosphite are given exemplifying aryl, aralkyl, alkyl, alkenyl, alkynyl and cycloalkyl groups and such groups carrying halogen and alkoxy substituents. Numerous specific phosphites are listed in all which, with the exception of diphenyl phosphite, R1, R2 and R3 are all organic groups. Substituted benzophenones specified are 2-hydroxy-5-methyl-, 2-hydroxy-3,5-dichloro-, 2-hydroxy-3,5-dimethyl-, 2,21-dihydroxy-4-octoxy- and 2,21-dihydroxy-4-decyloxy-benzophenones. Halogen-containing resins specified are polymers of vinyl chloride, vinylidene chloride, vinyl chloroacetate, chlorostyrenes and chlorobutadienes and their copolymers with one another and with vinyl esters, e.g. of acetic, propionic, butyric and benzoic acids; alkyl and allyl esters of acrylic and methacrylic acids; styrene, p-ethyl styrene, divinyl benzene, vinyl naphthalene and alpha methyl styrene; and C1-8 alkyl, allyl, methallyl and phenyl esters of maleic, crotonic, itaconic and fumaric acids. Other halogen-containing resins mentioned are copolymers of vinyl chloride and esters of aconitic acid and chlorinated polyvinyl acetate, polystyrene, polyvinyl chloride and natural and synthetic rubber, and rubber hydrochloride. The light-stabilizer mixture is particularly useful when used in conjunction with a heat-stabilizer mixture of a cadmium salt of an organic acid and an epoxy compound such as those disclosed in Specification 828,712, and/or with phosphate plasticizers, e.g. C6-14 alkyl diaryl phosphates. Exemplary compositions comprise polyvinyl chloride, di(2-ethylhexyl) phthalate, butyl benzyl phthalate, epoxidized soybean oil, coprecipitated barium-cadmium laurate, triphenyl phosphite and various benzophenones. Reference has been directed by the Comptroller to Specification 810,570.