Stabilization of vinyl halide resins

Vinyl halide and vinylidene halide resin compositions are stabilized against deterioration by light and heat by incorporation therein of a dihydrocarbyl tin or bis (trihydrocarbyl tin) succinate of formula: wherein R represents an alkyl, alkenyl, cycloalkyl or cycloalkenyl group containing 3-18 carbon atoms, and R1, R2 and R3 each represents a hydrocarbyl radical containing 3-14 carbon atoms. Compounds specified include dioctyl tin hexyl succinate, -hexenyl succinate, -octenyl succinate, -nonenyl succinate and -dodecenyl succinate. The compositions may be used for casting films or spinning fibres. In Example (10), a copolymer of acrylonitrile and vinylidene chloride containing an isomeric mixture of di(2-ethylhexyl) tin nonenyl succinates and dissolved in acetonitrile is spun into a bath comprising 95 parts by weight of water and 5 parts by weight of acetonitrile. The yarn is washed at 60 DEG C. and stretched 200% on to a metal bobbin. Other filament-forming compositions are (11) a vinylchloride/acrylontrile in acetone solution containing organotin stabilizers as in table C: (13) vinyl chloride/vinylidene chloride/acrylonitrile dissolved in acetonitrile containing stabilizers as in Table F: (15) vinyl chloride/vinyl acetate containing stearic acid as lubricant and stabilizers as in Table I; and 16 PVC plasticized with dioctyl phthalate. Other comonomers mentioned are styrene and dialkyl maleates and fumarates.ALSO:The invention comprises dihydrocarbyl-tin salts and bis-(trihydrocarbyl-tin) salts of alkyl, alkenyl, cycloalkyl and cycloalkenyl substituted succinic acids, of formula wherein R represents an alkyl, alkenyl, cycloalkyl or cycloalkenyl group containing 3 to 18 carbon atoms, and R1, R2 and R3 each represents a hydrocarbyl radical containing from 3 to 14 carbon atoms. Compounds specified include dioctyl tin -hexyl succinate, -hexenyl succinate, -octenyl succinate, -nonenyl succinate and -dodecenyl succinate. They may be prepared by reacting the substituted succinic acid or its anhydride with a di- or tri-hydrocarbyl tin oxide or hydroxide, preferably at a temperature between 60 DEG and 120 DEG C. and in the presence of a diluent which will form an azeotrope with water such as dioxan, benzene, toluene or methyl ethyl ketone. The compounds of the invention may be used in vinyl halide resin compositions as stabilizers against deterioration by light and heat (see Group IV(a)). Substituted succinic acids o