Abstract: A core-shell copolymer, a method of making the same, and a thermoplastic resin composition including the same are disclosed herein. In some embodiments, a core-shell copolymer includes a core and a shell surrounding the core, the core includes a conjugated diene-based monomer-derived repeating unit and a phosphate-based cross-linking agent-derived cross-linking part represented by Formula 1, and the shell includes a first alkyl (meth)acrylate monomer-derived repeating unit, a second alkyl (meth)acrylate monomer-derived repeating unit, and a sulfonate-based ionic monomer-derived repeating unit represented by Formula 2. The core is 68 parts to 92 parts and the shell is 8 parts to 32 parts, based on 100 parts of the core-shell copolymer, the core has a swell index of 2.7 to 10.9, the shell includes 1 wt % to 16 wt % of the sulfonate-based ionic monomer-derived repeating unit, and the shell has a weight average molecular weight of 105,000 g/mol to 645,000 g/mol.

Abstract: The present invention relates to a process for preparing polymeric particles which is specially designed to be served as an opacifying agent in coating compositions such as water-borne paints, paper coating compositions and molding compositions which have white or light color shades. In more detailed description, this invention is concerned with the process for making an aqueous dispersion of core-shell emulsion polymer particles comprising (1) preparing the core by polymerizing carboxylic acid monomers with other monoethylenically unsaturated monomers, (2) encapsulating said core with a rigid polymer shell by polymerizing shell-forming monomers, in the presence of said core particles, which are fed in such manner that compositional contents of monomers entering to a polymerization zone is changing gradually thoughout the period of monomer feeding, and (3) neutralizing with base so as to swell said core and form particles which, when dried, contain at least one void.