PURPOSE: To obtain a composition containing an alkali-resistant core-shell polymer.

CONSTITUTION: An alkali-resistant core-shell polymer having an acid-insoluble core and an acid-soluble shell is manufactured by a series of emulsion polymerization of a monomer mixture contg. an acid-ionizable functional group. The film manufactured from these alkali-resistant core-shell polymers has resistance against high pH environment and these polymers are suitable for the application in ink, transparent over-printing varnish, coating material, metal adhesion, fiber treatment, paper treatment, coating for plating cathode, dirt blocking, coagulant, and coherent.