Patent ID: 7579406

Claim:
A transparent thermoplastic resin composition comprising: A) 20-80 weight % of graft copolymer composed of a) conjugated diene rubber latex; b) intermediate layer on the conjugated diene rubber prepared by copolymerization of acrylic acid alkylester monomer and aromatic vinyl monomer in the presence of the (a) conjugated diene rubber latex; and c) graft layer prepared by copolymerization of methacrylic acid alkylester monomer or acrylic acid alkylester monomer, aromatic vinyl monomer and vinyl cyan monomer in the presence of the conjugated diene rubber latex with the intermediated layer (b) and B) 20-80 weight % of (meth)acrylic acid-aromatic vinyl compound-vinylcyanide copolymer prepared by copolymerization of methacrylic acid alkylester monomer or acrylic acid alkylester monomer, aromatic vinyl monomer and vinyl cyan monomer, wherein weight % is relative to the total weight % of the thermoplastic resin composition, and wherein the difference of refractive indices between conjugated diene rubber latex (a) and the total components of the intermediate layer (b) is less then 0.01; and wherein the difference of refractive indices among conjugated diene rubber latex (a), the total components of the intermediate layer (b) and the total components of the graft layer (c) is less than 0.005; and wherein the difference of refractive indices between the graft copolymer (A) and the (meth)acrylic acid-aromatic vinyl compound-vinylcyanide copolymer (B) is less than 0.005; wherein the transparent thermoplastic resin composition comprises 5-60 weight part of rubber latex (a), 2-40 weight part of intermediate layer (b), 30-90 weight part of graft layer (c) to 100 weight part of the graft copolymer (A, the sum of the rubber latex (a) and the intermediate layer (b) is 10-70 weight part to 100 part of the graft copolymer (A); wherein the intermediate layer (b) comprises 1-20 part of acrylic acid alkylester monomer and 1-20 weight part of aromatic vinyl monomer to 100 weight part of the graft copolymer (A); wherein the graft layer (c) comprises 20-65 weight part of methacrylic acid alkylester or acrylic acid alkylester monomer, 8-25 weight part of aromatic vinyl monomer and 1-20 weight part of vinyl cyan monomer to 100 weight part of the graft copolymer (A); and wherein the meth(acrylic acid-aromatic vinyl compound-vinylcyanide copolymer (B) contains 40-75 weight part of methacrylic acid alkylester monomer or acrylic acid alkylester monomer, 15-40 weight part of aromatic vinyl monomer, and 3-20 weight part of vinyl cyan monomer to 100 weight part of the whole (meth)acrylic acid-aromatic vinyl compound-vinylcyanide copolymer (B).