Double-faced pressure-sensitive adhesive sheet and use thereof

Patent metadata

Field	Value
Publication number	US-2017218232-A1
Application number	US-201715417349-A
Country	US
Kind code	A1
Filing date	Jan 27, 2017
Priority date	Jan 29, 2016
Publication date	Aug 3, 2017
Grant date	—

Abstract

Provided is a double-faced PSA sheet having excellent detergent resistance. The PSA sheet according to this invention comprises a PSA layer and is adhesive on both faces. The PSA sheet shows a push-peel strength of 30 N/cm 2 or greater after a detergent immersion test involving immersion in a standard detergent at 40° C. for 24 hours. It also has an adhesive strength retention rate of 50% or higher, determined as the ratio of push-peel strength P 2 after the detergent immersion test to push-peel strength P 1 before the detergent immersion test.

First claim

What is claimed is:

1 . An adhesively double-faced pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer,
exhibiting a push-peel strength of 30 N/cm 2 or greater after a detergent immersion test involving immersion in a standard detergent at 40° C. for 24 hours, and having an adhesive strength retention rate of 50% or higher, determined as the ratio of push-peel strength P 2 after the detergent immersion test to push-peel strength P 1 before the detergent immersion test.

2 . The double-faced pressure-sensitive adhesive sheet according to claim 1 , wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer comprising an acrylic polymer as its base polymer.

3 . The double-faced pressure-sensitive adhesive sheet according to claim 2 , wherein the acrylic polymer is crosslinked with at least one species of crosslinking agent selected from the group consisting of isocyanate crosslinking agents and epoxy-based crosslinking agents.

4 . The double-faced pressure-sensitive adhesive sheet according to claim 2 , wherein the pressure-sensitive adhesive layer comprises at least one species of tackifier resin selected from the group consisting of a rosin-based tackifier resin, a terpene-based tackifier resin, a phenolic tackifier resin and a petroleum resin.

5 . The double-faced pressure-sensitive adhesive sheet according to claim 4 , wherein the tackifier resin content in the pressure-sensitive adhesive layer is 20 parts to 45 parts by weight to 100 parts by weight of the acrylic polymer.

6 . The double-faced pressure-sensitive adhesive sheet according to claim 1 , wherein the pressure-sensitive adhesive layer has a degree of crosslinking of 30% or higher.

7 . The double-faced pressure-sensitive adhesive sheet according to claim 1 , comprising a foam substrate and having the pressure-sensitive adhesive layer on each face of the foam substrate.

8 . The double-faced pressure-sensitive adhesive sheet according to claim 1 , consisting of the pressure-sensitive adhesive layer.

9 . A laminate comprising an adhering layer formed of the double-faced pressure-sensitive adhesive sheet according to claim 1 and a fluororesin layer applied to one adhesive face of the adhering layer.

10 . The double-faced pressure-sensitive adhesive sheet according to claim 1 used for bonding components of a portable electronic device.

Assignees

• Nitto Denko Corp

Inventors

• Niwa Masahito
• Nishiwaki Masataka
• Yoshida Noboru
• Higuchi Naoaki
• Tosaki Yutaka
• Zhu Huairui
• Ding Junyi

Classifications

• B32B27/08

  of synthetic resin · CPC title

• B32B7/06 Primary

  permitting easy separation · CPC title

• C09J7/0289

  Chemistry & Metallurgy · mapped topic

• C09J133/066

  containing -OH groups · CPC title

• C09J7/00

  Adhesives in the form of films or foils · CPC title