Clear, impact modified, heat resistant polyvinyl halide compositions

Abstract

A clear, impact modified, heat resistant polyvinyl chloride composition is provided comprising (a) at least one polyvinyl halide; (b) at least one clear impact modifier possessing a refractive index which is not more than about 2% above or below the refractive index of the polyvinyl halide; and (c) at least one clear heat modifier comprising a terpolymer obtained by the copolymerization of a vinyl aromatic monomer, an acrylonitrile and an alkyl acrylate or alkyl methacrylate, wherein the terpolymer possesses a refractive index which is not more than about 2% above or below the refractive index of the polyvinyl halide and possesses a weight average molecular weight ranging from about 75,000 to about 400,000.

1 . A clear, impact modified, heat resistant polyvinyl halide composition comprising:
 (a) at least one polyvinyl halide;   (b) at least one clear impact modifier possessing a refractive index which is not more than about 2% above or below the refractive index of the polyvinyl halide; and   (c) at least one clear heat modifier comprising a terpolymer obtained by the copolymerization of a vinyl aromatic monomer, an acrylic nitrile monomer and an alkylacrylate or alkylmethacrylate, wherein the terpolymer possesses a refractive index which is not more than about 2% above or below the refractive index of the polyvinyl halide and possesses a weight average molecular weight ranging from about 75,000 to about 400,000;   wherein (a) comprises from about 20 to about 60 weight percent, (b) comprises from about 10 to about 25 weight percent and (c) comprises from about 25 to about 60 weight percent, based on the total weight of the combined weight of (a), (b) and (c).   
     
     
         2 . The polyvinyl halide composition of  claim 1 , wherein the vinyl aromatic monomer is selected from the group consisting of styrene, alphamethylstyrene, halogenated styrene, vinyltoluene, alkoxystyrene and mixtures thereof. 
     
     
         3 . The polyvinyl halide composition of  claim 1 , wherein the acrylic nitrile monomer is selected from the group consisting of methacrylonitrile, ethacrylonitrile, chloroacrylonitrile, acrylonitrile and mixtures thereof. 
     
     
         4 . The polyvinyl halide composition of  claim 1 , wherein the alkyl acrylate or alkyl methacrylate is selected from a group consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and mixtures thereof. 
     
     
         5 . The polyvinyl halide composition of  claim 1 , wherein the terpolymer possesses a weight average molecular weight from about 100,000 to about 200,000. 
     
     
         6 . The polyvinyl halide composition of  claim 1 , wherein the polyvinyl halide is selected from the group consisting of vinyl halide homopolymers, vinyl halide copolymers and mixtures thereof. 
     
     
         7 . The polyvinyl halide composition of  claim 6 , wherein the vinyl halide homopolymers are selected from the group consisting of polyvinyl chloride, polyinylidiene chloride, polyvinyl bromide, polyvinyl fluoride, polyvinylidene fluoride and mixtures thereof. 
     
     
         8 . The polyvinyl halide composition of  claim 6 , wherein the vinyl halide copolymers are selected from the group consisting of vinylidene chloride, vinyl acetate vinyl butyrate, vinyl benzoate, diethyl fumarate, diethyl maleate, vinyl propionate, methyl acrylate, 2-ethyhexyl acrylate, butyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, methyl α-chloracrylate, styrene, vinyl ethyl ether, vinyl chloroethyl ether, vinyl phenyl ether, vinyl methyl ketone, vinyl phenyl ketone, 1-fluoro-1-chloroethylene, acrylonitrile, chloroacrylonitrile, allylidene diacetate, chloroallylidene diacetate, ethylene, propylene and mixtures thereof. 
     
     
         9 . The polyvinyl halide composition of  claim 6 , wherein the vinyl halide polymer blends are selected from the group consisting polyvinyl chloride and polyethylene, polyvinyl chloride and chlorinated polyethylene, polyvinyl chloride and polymethyl methacrylate, polyvinyl chloride and polybutylmethacrylate, polyvinyl chloride and polystyrene, polyvinyl chloride and acrylonitrile-butadiene-styrene copolymer, polyvinyl chloride and polyethylene and polymethyl methacrylate, and mixtures thereof. 
     
     
         10 . The polyvinyl halide composition of  claim 9 , wherein the polymer blends comprise physical blends of at least two distinct polymeric species and contain from about 25 to about 95 weight percent vinyl halide homopolymer. 
     
     
         11 . The polyvinyl halide composition of  claim 1 , wherein the impact modifier comprises a rubber modified with a thermoplastic resin. 
     
     
         12 . The polyvinyl halide compositions of  claim 11 , wherein the impact modifiers are selected from a group consisting of ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, polybutadiene-acrylonitrile-styrene copolymer, polybutadiene-styrene-methyl methacrylate, polybutylacrylate, crosslinked acrylic rubber, styrene-butadiene copolymer and acrylonitrile-butadiene copolymer. 
     
     
         13 . The polyvinyl halide composition of  claim 1 , characterized in that the ⅛ inch Izod impact strength measured at a temperature of 23° C. is at least about 1.0 ftlb/in. 
     
     
         14 . The polyvinyl halide composition of  claim 1 , wherein the impact modifier possesses a refractive index which is not more than about 1% above or below the refractive index of the polyvinyl halide. 
     
     
         15 . The polyvinyl halide composition of  claim 1 , wherein the impact modifier possesses a refractive index which is not more than about 0.05% above or below the refractive index of the polyvinyl halide. 
     
     
         16 . The polyvinyl halide composition of  claim 1 , wherein the terpolymer possesses a refractive index which is not more than about 1% above or below the refractive index of the polyvinyl halide. 
     
     
         17 . The polyvinyl halide composition of  claim 1 , wherein the terpolymer possesses a refractive index which is not more than about 0.05% above or below the refractive index of the polyvinyl halide.