Adhesive sheet

Patent metadata

Field	Value
Publication number	US-2017218231-A1
Application number	US-201515515191-A
Country	US
Kind code	A1
Filing date	Sep 28, 2015
Priority date	Sep 30, 2014
Publication date	Aug 3, 2017
Grant date	—

Abstract

A pressure-sensitive adhesive sheet according to the present invention includes an irradiation-curable acrylic pressure-sensitive adhesive layer. The acrylic pressure-sensitive adhesive layer includes an acrylic polymer and a multifunctional acrylic oligomer. The acrylic pressure-sensitive adhesive layer, after curing, has a Young's modulus of 500 kPa to 10000 kPa at 23° C. The acrylic pressure-sensitive adhesive layer, after curing, has an adhesive strength of 3.0 N/20 mm or more. The acrylic pressure-sensitive adhesive layer before curing may have an adhesive strength of typically 3.0 N/20 mm or more. The acrylic pressure-sensitive adhesive layer before curing may have a Young's modulus of typically 30 kPa to 200 kPa at 23° C.

First claim

1 . A pressure-sensitive adhesive sheet comprising
an irradiation-curable, acrylic pressure-sensitive adhesive layer, the acrylic pressure-sensitive adhesive layer comprising:
an acrylic polymer; and
a multifunctional acrylic oligomer,
the acrylic pressure-sensitive adhesive layer, after curing, having a Young's modulus of 500 kPa to 10000 kPa at 23° C., the acrylic pressure-sensitive adhesive layer, after curing, having an adhesive strength of 3.0 N/20 mm or more.

2 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic pressure-sensitive adhesive layer before curing has an adhesive strength of 3.0 N/20 mm or more.

3 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic pressure-sensitive adhesive layer before curing has a Young's modulus of 30 kPa to 200 kPa at 23° C.

4 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic pressure-sensitive adhesive layer, after curing, has a gel fraction of 70 mass percent or more.

5 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic polymer is derived from monomer components comprising 0.5 to 30 mass percent of one or more nitrogen-containing monomers.

6 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic polymer is derived from monomer components comprising 1 to 30 mass percent of one or more hydroxy-containing monomers.

7 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic polymer is derived from monomer components approximately devoid of acidic-group-containing monomers.

8 . The pressure-sensitive adhesive sheet according to claim 1 , wherein the acrylic polymer has a weight-average molecular weight of 40×10 4 to 200×10 4 .

9 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the multifunctional acrylic oligomer contains two or more (meth)acryloyl groups per molecule.

10 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the multifunctional acrylic oligomer comprises at least one substance selected from the group consisting of: polyester (meth)acrylates; epoxy (meth)acrylates; urethane (meth)acrylates; and bisphenol-A ethylene oxide adduct diacrylates.

11 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the multifunctional acrylic oligomer has a weight-average molecular weight of 400 to 10000.

12 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the multifunctional acrylic oligomer gives a homopolymer having a hardness of 4B or more as measured in conformity with JIS K 5600-5-4.

13 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic pressure-sensitive adhesive layer further comprises one or more photoinitiators.

14 . The pressure-sensitive adhesive sheet according to claim 13 ,
wherein the acrylic pressure-sensitive adhesive layer comprises: 0.05 to 40 parts by mass of the multifunctional acrylic oligomer; and 0.05 to 5 parts by mass of the photoinitiator, per 100 parts by mass of the acrylic polymer.

15 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic pressure-sensitive adhesive layer further comprises 0.05 to 5 parts by mass of one or more crosslinkers per 100 parts by mass of the acrylic polymer.

16 . The pressure-sensitive adhesive sheet according to claim 1 ,
wherein the acrylic pressure-sensitive adhesive layer further comprises 0.01 to 1 part by mass of one or more silane coupling agents per 100 parts by mass of the acrylic polymer.

Assignees

• Nitto Denko Corp

Inventors

• Suzuki Toshihide

Classifications

• C09J133/02

  Homopolymers or copolymers of acids; Metal or ammonium salts thereof · CPC title

• C09J2433/00

  Presence of (meth)acrylic polymer · CPC title

• C09J2203/326

  for bonding electronic components such as wafers, chips or semiconductors · CPC title

• C08L33/14

  of esters containing halogen, nitrogen, sulfur, or oxygen atoms in addition to the carboxy oxygen · CPC title

• C09J133/00 Primary

  Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers · CPC title