Patent ID: 8685492

Claim:
A method for producing a double-sided pressure-sensitive adhesive sheet having pressure-sensitive adhesive layers formed using an aqueous dispersion-type pressure-sensitive adhesive composition and a nonwoven fabric substrate supporting the pressure-sensitive adhesive layers, said method comprising: preparing an aqueous dispersion-type pressure-sensitive adhesive composition; preparing a nonwoven fabric substrate as a support, wherein the nonwoven fabric substrate has a grammage of 5 g/m 2 to 25 g/m 2 , a thickness of 15 Î¼m to 70 Î¼m, and a bulk density of 0.2 g/cm 3 to 0.5 g/cm 3 ; and forming pressure-sensitive adhesive layers which are integrated in the nonwoven fabric substrate and which are obtained by drying said pressure-sensitive adhesive composition, wherein said pressure-sensitive adhesive layers are integrated in the nonwoven fabric substrate so that the area of gaps observed in a vertical cross-section perpendicular to the machine direction of said nonwoven fabric substrate is 500 Î¼m 2 or less per 400 Î¼m length of the vertical cross-section, the pressure-sensitive adhesive composition is an aqueous emulsion-type pressure-sensitive adhesive composition comprising an acrylic polymer in an amount of over 50 mass % based on the solid part of the pressure-sensitive adhesive composition, the nonwoven fabric substrate is composed of natural fiber or at least one chemical fiber selected from the group consisting of rayon, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, polyolefin fiber, and polyurethane fiber, and a peeling height of the double-sided pressure-sensitive adhesive sheet in a repulsion resistance evaluation is 5 mm or less, wherein the repulsion resistance evaluation test is conducted by a method comprising the steps of: peeling off a release liner protecting one surface of the double sided pressure-sensitive adhesive sheet; laminating the exposed pressure-sensitive adhesive layer on an aluminum plate 0.5 mm thick, 10 mm wide, and 90 mm long to prepare a test piece; winding the length of the test piece in an arc around a round bar 50 mm in diameter; peeling off the release liner from the outer surface of the test piece to expose the pressure-sensitive adhesive layer, which is then crimped to a polypropylene plate using a laminator; storing the test piece crimped to the polypropylene plate for 24 hours in a 23Â° C. environment and then heated for 2 hours at 70Â° C.; and measuring the height (mm) of the test piece floating above the surface of the polypropylene plate.