Mitsubishi Rayon Company, Limited

Jinpee Kobayashi

Kazuo Kishida

Fumio Ide

Hajime Fukunaga

A vinyl chloride resin composition is prepared by (1) preparing an acrylic elastomer (A) by (a) polymerizing 30 to 50% by wt of an aromatic vinyl monomer in the presence of a polyfunctional cross-linking agent having at least one allyl group and a carboxylate anion surfactant as an emulsifier at a pH maintained between 7.0-9.5 and then (b) graft-polymerizing 50 to 70% by wt of an alkyl acrylate of 2 to 10 carbon atoms in the alkyl group onto said polymerized aromatic vinyl polymer in the presence of from 0.1 to 3 parts by wt of a polyfunctional cross-linking agent with at least one allyl group based on the weight of the sum of said aromatic vinyl monomer and said alkyl acrylate; (2) preparing a graft copolymer (B) by graft-polymerizing from 20 to 70 parts by wt of an aromatic vinyl monomer and methyl methacrylate onto 30 to 80 parts by weight of said acrylic elastomer (A) wherein from 70% to 20% by wt of said aromatic vinyl monomer is first graft-polymerized onto said elastomer (A) in the presence of an oil soluble initiator and then graft-polymerizing from 30 to 80% by wt of methyl methacrylate onto said grafted elastomer; and (3) mixing from 60 to 97 parts by wt of a vinyl chloride polymer with 3 to 40 parts by wt of said graft copolymer (B).

Process for preparing vinyl chloride resin-acrylic graft copolymer

A transparent vinyl chloride resin composition excellent in surface gloss and resistant to weathering and impact, comprising 97 to 60 parts by weight of a vinyl-chloride polymer and 3 to 40 parts by weight of a graft copolymer (B) obtained by emulsion-polymerizing a mixture of an aromatic vinyl monomer and a polyfunctional crosslinking agent having at least one allyl group, then polymerizing, in the presence of the resulting polymer latex, a mixture of an alkyl acrylate having 2 to 10 carbon atoms in the alkyl group and a polyfunctional crosslinking agent having at least one allyl group to form an acrylic elastomer (A) in the first stage the proportions of said alkyl acrylate and said aromatic vinyl monomer being 50 to 70% by weight and 50 to 30% by weight, respectively, and the amount of said crosslinking agent used being 0.1 to 5 parts by weight in total per 100 parts by weight of the sum of said alkyl acrylate and said aromatic vinyl monomer; and graft-polymerizing, in the presence of the resulting acrylic elastomer (A), first methyl methacrylate and subsequently an aromatic vinyl monomer in the second stage, the proportions of said methyl methacrylate and said aromatic vinyl monomer being 30 to 80% by weight and 70 to 20% by weight, respectively, and the total amount of said methyl methacrylate and said aromatic vinyl monomer used being 70 to 20 parts by weight per 30 to 80 parts by weight of said acrylic elastomer (A).

Growing community of inventors

Ohtake, Japan

Jinpee Kobayashi