Nitto-denko Corporation

Naoki Okochi

Masahiko Ando

Shigeki Ishiguro

Kaoru Aizawa

Masato Shirai

Hiroomi Hanai

Toshiyuki Ohshima

A removable pressure sensitive adhesive composition includes at least (A) a hydroxyl-group-containing acrylic polymer, (B) an amine compound containing plural hydroxyl groups, and (C) a polyisocyanate compound and has a gel fraction of equal to or more than 70% by weight after drying or curing. A removable pressure sensitive adhesive sheet has a removable pressure sensitive adhesive layer including the removable pressure sensitive adhesive composition formed on one or both sides of a base material. The sheet may have a 180&#xb0; peel force with respect to a melamine-faced steel sheet of 5 N/20-mm or less and may have a 180 &#xb0; peel force after adhesion at 50&#xb0; C. for 48 hours of 1.2 times or less the initial adhesion (after adhesion at 23&#xb0; C. for 20 minutes), as determined at a pulling rate of 300 mm/minute, 23&#xb0; C. and 50% relative humidity.

Removable pressure sensitive adhesive compositions and sheets

A highly adhesive pressure sensitive adhesive composition includes at least (A) a hydroxyl-group-containing acrylic polymer, (B) an amine compound containing plural hydroxyl groups, and (C) a polyisocyanate compound and has a gel fraction of equal to or more than 10% by weight and less than 70% by weight after drying or curing. A highly adhesive pressure sensitive adhesive sheet has a highly adhesive pressure sensitive adhesive layer including the highly adhesive pressure sensitive adhesive composition formed on one or both sides of a base material. The sheet preferably has a 180&#xb0; peel force with respect to a stainless steel sheet of 10 N/20-mm or more as determined at a pulling rate of 300 mm/minute, 23&#xb0; C. and 50% relative humidity.

Highly adhesive pressure sensitive adhesive compositions and sheets

An adhesive sheet comprising a substrate having formed on one surface or both surfaces thereof a rubber-like elastic layer, a heat-expandable layer, and an adhesive layer in the order from the substrate side.

Growing community of inventors

Ibaraki, Japan

Naoki Okochi