SYNTHETIC RESIN EMULSION, EASILY WATER-SWELLABLE PRESSURE-SENSITIVE ADHESIVE COMPOSITIONS CONTAINING THE SAME AND PROCESS FOR PRODUCTION OF THE EMULSION

摘要

A synthetic resin emulsion containing polymer particles having core-shell structure wherein the shell is made of a copolymer of an unsaturated carboxylic acid and a hydrophilic comonomer and the core is made of a copolymer produced from a monomer mixture consisting of a radical-polymerizable main monomer and a radical-polymerizable functional monomer which are so selected as to form a copolymer having a glass transition temperature (Tg) of -20°C or below, characterized by being produced by adding the above monomer mixture for core formation and a pH regulator to an aqueous copolymer solution which is obtained by copolymerizing an unsaturated carboxylic acid with a hydrophilic comonomer in an aqueous medium and is not neutralized and then polymerizing the monomer mixture. The use of the synthetic resin emulsion gives pressure-sensitive adhesives which are excellent in pressure-sensitive adhesion properties such as bond strength, cohesive force, and tack and can be easily swelled in water even without alkali treatment.