Acrylic polymer fine particles and plastisol using the same

Acrylic polymer fine particles which comprise primary particles P having a core-shell structure comprising a core polymer C and a shell polymer S, wherein the average particle diameter of the primary particles P is not less than 250 nm, the core polymer C and the shell polymer S are copolymers of the following monomer mixtures Mc and Ms, respectively, and the weight ratio of Mc and Ms is 10/90-90/10;

• Mc:
• methyl methacrylate 20-85 mol%
• (meth)acrylic ester of C2-C8 aliphatic alcohol and/or aromatic alcohol
• 15-80 mol%, and
• other copolymerizable monomers
• not more than 30 mol%
• , when the total amount of these monomers is 100 mol%;
• Ms:
• methyl methacrylate 20-79.5 mol%
• (meth)acrylic ester of C2-C8 aliphatic alcohol and/or aromatic alcohol
• 5-40 mol%
• monomer containing carboxyl group or sulfonic acid group
• 0.5-10 mol%, and
• other copolymerizable monomers
• not more than 30 mol%
• , when the total amount of these monomers is 100 mol%.