Pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet

A water-dispersed pressure-sensitive adhesive composition comprising (a) as a base polymer thereof a water-dispersed acrylic copolymer (component L) with a glass transition temperature (Tg) in the range of −70° C. to −50° C., and (b) 10 to 40 parts by weight of a tackifying resin (component T) in relation to 100 parts by weight of the component L based on solid content,nwherein the component L is an acrylic copolymer obtained by polymerization of a monomer starting material comprising:60 wt % or more of an alkyl (meth)acrylate having a C8-12 alkyl group, and5 wt % or less of a radical polymerizable monomer having a carboxyl group (monomer b), wherein the monomer b comprises acrylic acid and methacrylic acid at an acrylic acid/methacrylic acid weight ratio of 0.3 to 4; andwherein, when a double-sided pressure-sensitive adhesive sheet is fabricated using the adhesive composition, the pressure-sensitive adhesive sheet satisfies all of the following properties:(A) an average adhesive strength on stainless steel of 11 N/20 mm or greater on either side;(B) an average adhesive strength on polypropylene of 8.5 N/20 mm or greater on either side;(C) a hold time in an 80° C. holding strength test of 1 hour or longer on either side; and(D) a gap height of an edge of a test piece in a curved surface adhesion test of 10 mm or less.

A water-dispersed pressure-sensitive adhesive composition comprising as a base polymer thereof a water-dispersed acrylic copolymer (component L) with a glass transition temperature (Tg) in the range of −70° C. to −50° C.,nwherein the component L is obtained by polymerization of a monomer starting material comprising 5 wt % or less of a radical polymerizable monomer having a carboxyl group (monomer b), wherein the monomer b comprises acrylic acid and methacrylic acid at an acrylic acid/methacrylic acid weight ratio of 0.3 to 4; andwherein, when a double-sided adhesive sheet is fabricated using the adhesive composition, the pressure-sensitive adhesive sheet satisfies all of the following properties:(B) an average adhesive strength on polypropylene of 8.5 N/20 mm or greater on either side;(C) a hold time in an 80° C. holding strength test of 1 hour or longer on either side;(D) a gap height at an edge of a test piece in a curved surface adhesion test of 10 mm or less; and(H) a total amount of volatile organic compounds (TVOC) emitted from the sheet when heated for 30 min at 80° C. being 1000 μg or less per 1 gram of the adhesive sheet.