| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an aqueous pressure-sensitive adhesive composition suitable for forming a pressure-sensitive adhesive sheet exhibiting pressure-sensitive adhesive strength, high-temperature cohesive strength and terminal peeling preventing properties at high levels in good balance. SOLUTION: The method for producing the aqueous pressure-sensitive adhesive composition in which an acrylic polymer is dispersed in water. The method comprises carrying out emulsion polymerization of a monomer raw material in two stages, obtaining an aqueous emulsion of the acrylic polymer, compounding the emulsion with a cross-linking agent and affording the aqueous pressure-sensitive adhesive composition. The emulsion polymerization is carried out so that the acrylic polymer having≥3 to≤15% mass ratio of an ethyl acetate-insoluble portion and≥700,000 to≤1,000,000 mass-average molecular weight of a THF-soluble portion is obtained. The cross-linking agent is compounded so that the mass ratio of the ethyl acetate-insoluble portion accounts for≥40 to≤70% of the pressure-sensitive adhesive after cross-linking. COPYRIGHT: (C)2008,JPO&INPIT
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