WATER-DISPERSING ACRYLIC ADHESIVE COMPOSITION AND ADHESIVE SHEET

摘要

Provided is a water-dispersible acrylic pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive layer which is resistant to increase in adhesive strength with time, has a good appearance, and less stains an adherend. The water-dispersible acrylic pressure-sensitive adhesive composition includes an acrylic emulsion polymer; and a water-insoluble crosslinking agent having two or more carboxyl-reactive functional groups per molecule. The acrylic emulsion polymer is formed from constitutive monomers essentially including a (meth)acrylic alkyl ester (A), a carboxyl-containing unsaturated monomer (B), and at least one monomer (C) selected from methyl methacrylate, vinyl acetate, and diethylacrylamide and has a solvent-insoluble content of 70 percent by weight or more. When the acrylic pressure-sensitive adhesive composition is applied so as to have a dry thickness of 50 µm, dried at 120°C for 2 minutes, and aged at 50°C for 3 days to give a cross-linked acrylic pressure-sensitive adhesive film, the film has a solvent-insoluble content of 90 percent by weight or more and an elongation at break of 130% or less at 23°C.