| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a copolymer latex for a chipping-resistant paint providing an aqueous paint composition excellent in blister prevention during baking and drying of a thick film, and chipping-resistance during baking and drying of a thin film, and compatibly having effects to adhesiveness to a base material and long term leaving after a paint is applied with good balance.SOLUTION: In the method for producing the copolymer latex for the chipping-resistant paint having 180 to 400 nm number-average particle diameter, 95 to 100 mass% toluene-insoluble component, a degree of swelling with toluene of 3.0 to 6.5, -70 to -20°C glass transition starting temperature and 10 to 100°C glass transition ending temperature, emulsion polymerization of a monomer mixture including 30 to 70 mass% conjugated diene monomer, 0.1 to 15 mass% ethylenically unsaturated carboxylic acid monomer and 15 to 69.9 mass% other copolymerizable monomer [(a)+(b)+(c)=100 mass%] is performed together with a chain transfer agent in at least two steps. |
