Patent ID: 6136918
Filing Date: 2000-10-24
Classification: C08C,C08F,C08L

Abstract:
A rubber latex having particles of an average particle size of not less than 200 nm grown through cohesion by adding 0.1-15 weight parts, in terms of solid content, of an acid group-containing latex (A) having an average particle size of 50-500 nm to 100 weight parts, in terms of solid content, of a rubber latex (B),wherein said acid group-containing latex (A) is prepared by polymerizing a monomer mixture comprising (a), (b), (c) and (d), the sum of (a), (b), (c) and (d) being equal to 100 weight percent:(a) 5-25 weight % of at least one unsaturated acid selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid,(b) 20-95 weight % of at least one alkyl methacrylate having a C.sub.1-12 alkyl group,(c) 0-30 weight % of at least one alkyl acrylate having a C.sub.1-12 alkyl group,(d) 0-40 weight % of at least one monomer copolymerizable with (a), (b) and (c), and selected from the group consisting of aromatic vinyls, compounds having at least two polymerizable functional groups in a molecule, and vinyl cyanides,wherein said acid group-containing latex (A) is made by first polymerizing a monomer portion (A1), which is 5-40 weight % of (A), to obtain a copolymer having a glass transition temperature from -95.degree. C. to 40.degree. C., and then polymerizing a monomer portions (A2), which is the residual 95-60 weight % of (A), to obtain a copolymer having a glass transition temperature from -20.degree. C. to 80.degree. C., wherein the glass transition temperature of (A1) is lower than the glass transition temperature of (A2).