Aqueous pressure-sensitive adhesive composition and utilization thereof

摘要

Provided are a pressure-sensitive adhesive (PSA) sheet having excellent foam repulsion resistance and an aqueous PSA composition suitable for preparing this sheet. The composition primarily comprises an acrylic polymer obtained by polymerizing a starting monomer material containing an alkyl (meth)acrylate as a main monomer and both acrylic acid and methacrylic acid. The acrylic polymer preferably has a weight average molecular weight of 65 × 10 4 to 100 × 10 4 . The starting monomer material is preferred to further contain a silanol-forming monomer and polymerized without the silanol-forming monomer to produce a polymer having a gel fraction of 7 to 17 mass%. The post-crosslink PSA preferably has a gel fraction of 20 to 55 mass%.