Aqueous, silicone-modified acrylate polymer emulsion

An aqueous, silicone-modified acrylate polymer emulsion, which is an acrylate polymer emulsion produced by subjecting a monomer system (A) to emulsion polymerization in an aqueous medium in the presence of an emulsifier (B), wherein said acrylate polymer emulsion is silicone-modified using a silicone structure-containing modifier (C) during or after said emulsion polymerization, and wherein each of the emulsion polymerization and the silicone modification of the acrylate polymer emulsion is performed at a pH of 4.0 or less;

• wherein said monomer system (A) comprises an acrylate monomer selected from the group consisting of an acrylic ester, a methacrylic ester and a mixture thereof, said acrylate monomer containing 5% by weight or more based on the weight of said monomer system (A), of a C.sub.5 -C.sub.12 cycloalkyl ester of acrylic acid, a C.sub.5 -C.sub.12 cycloalkyl ester of methacrylic acid, or a mixture thereof;
• wherein said emulsifier (B) is selected from the group consisting of a sulfonic acid group-containing ethylenically unsaturated monomer, a sulfonate group-containing ethylenically unsaturated monomer, and a mixture thereof;
• wherein said silicone structure-containing modifier (C) comprises a silicone structure-containing silane (I) represented by the formula:
• R.sup.1 --Si--(R.sup.2).sub.3
• wherein R.sup.1 represents a hydrogen atom, a C.sub.1 -C.sub.16 aliphatic hydrocarbon group, a C.sub.5 -C.sub.10 aryl group, a C.sub.5 -C.sub.6 cycloalkyl group, a vinyl group, an acrylic C.sub.1 -C.sub.10 alkyl group or a methacrylic C.sub.1 -C.sub.10 alkyl group, and each R.sup.2 independently represents a C1-C8 alkoxyl group, an acetoxyl group or a hydroxyl group;
• and
• wherein said monomer system (A) and said emulsifier (B) are, respectively, used in an amount of from 80% to 99.95% by weight and in an amount of from 0.05% to 20% by weight, based on the total weight of monomer system (A) and emulsifier (B), and said silicone structure-containing modifier (C) is used in an amount which satisfies the following relationship:
• ##EQU3## wherein (A), (B) and (C), respectively, represent the amount of monomer system (A), emulsifier (B) and modifier (C) in weight percent based on the total weight of materials (A), (B) and (C).