Polymer emulsion, aqueous pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet

摘要

PROBLEM TO BE SOLVED: To provide a pressure sensitive adhesive sheet excellent in adhesiveness and capable of being stuck again, an aqueous adhesive composition suitable for producing the same and an aqueous emulsion suitable for a binder composition of the aqueous adhesive composition.SOLUTION: An emulsion of heterogeneous polymer composed of a segment of a soft polymer having Tg of lower than -35°C and obtained by emulsification polymerizing a monomer component (A1) of 65 to 90 mass% based on the total monomers and a segment of a hard polymer obtained by emulsification polymerizing 5 to 20 mass of a monomer component (B) providing Tg of lower than -35°C and 5 to 20 mass of a monomer component (B) providing Tg of higher than -20°C in the presence of the soft polymer is used as a binder component of an aqueous adhesive composition.