Cationic UV-crosslinkable acrylic polymers for pressure sensitive adhesives

• US 9,469,794 B2
• Filed: 06/19/2014
• Issued: 10/18/2016
• Est. Priority Date: 03/09/2010
• Status: Active Grant

• Current Assignee: Henkel AG & Co KGaA
• Original Assignee: Henkel IP & Holding GmbH (Henkel AG & Co KGaA)
• Inventors: Liu, Yuxia, Palasz, Peter, Paul, Charles W., Foreman, Paul B.
• Primary Examiner(s): MCCLENDON, SANZA L
• Application Number:
  US14/309,420
• Publication Number:
  US 20140303274A1
• Time in Patent Office: 852 Days
• US Class Current: 1/1
• CPC Class Codes: C08F 212/04 containing one ring
• CPC Class Codes: C08F 220/14 Methyl esters , e.g. methyl (meth)acrylate
• CPC Class Codes: C08F 220/1808 C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate
• CPC Class Codes: C08F 220/281 and containing only one oxygen, e.g. furfuryl (meth)acrylate or 2-methoxyethyl (meth)acrylate
• CPC Class Codes: C08F 220/32 containing epoxy radicals
• CPC Class Codes: C08F 220/325 containing glycidyl radical, e.g. glycidyl (meth)acrylate
• CPC Class Codes: C08F 230/08 containing silicon
• CPC Class Codes: C08L 2312/06 by radiation
• CPC Class Codes: C09J 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C09J 133/14 of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
• CPC Class Codes: C09J 137/00 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 a heterocyclic ring containing oxygen based on polymers of cyclic esters of polyfunctional acids C09J131/00; based on polymers of cyclic anhydrides of unsaturated acids C09J135/00; Adhesives based on derivatives of such polymers
• CPC Class Codes: C09J 143/04 Homopolymers or copolymers of monomers containing silicon
• CPC Class Codes: C09J 2301/416 use of irradiation
• CPC Class Codes: C09J 2423/106 in the substrate
• CPC Class Codes: C09J 2467/006 in the substrate
• CPC Class Codes: C09J 7/385 Acrylic polymers
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2809 including irradiated or wave energy treated component
• CPC Class Codes: Y10T 428/2826 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/2852 Adhesive compositions
• CPC Class Codes: Y10T 428/287 : including epoxy group or epoxy polymer
• CPC Class Codes: Y10T 428/2878 : including addition polymer from unsaturated monomer
• CPC Class Codes: Y10T 428/2891 : including addition polymer from alpha-beta unsaturated carboxylic acid [e.g., acrylic acid, methacrylic acid, etc.] Or derivative thereof
• CPC Class Codes: Y10T 428/31504 : Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31511 : Of epoxy ether
• CPC Class Codes: Y10T 428/31855 : Of addition polymer from unsaturated monomers

Abstract

An ultraviolet (UV) crosslinkable acrylic pressure sensitive adhesive comprises an acrylic copolymer and a cationic photoinitiator. The acrylic copolymer comprises pendant reactive functional groups. The pressure sensitive adhesive formed from the acrylic copolymer with the pendant reactive functional groups result in high green strength and/or high temperature holding strength of the adhesive.

Claims

1. An ultra-violet curable pressure sensitive adhesive comprising an acrylic polymer and a cationic photoinitiator, wherein said acrylic polymer comprises:

(i) an acrylic monomer consisting of an acrylic or methacrylic acid derivative of the formula CH₂═

CH(R₁)(COOR₂), wherein R₁ is H or CH₃ and R₂ is C_1-20 alkyl chain;

(ii) a monomer, wherein the monomer comprises a pendant reactive functional groups selected from

(1) mono-substituted oxirane, and

(2) cycloaliphatic epoxide having the formula;

2. The ultra-violet curable pressure sensitive adhesive of claim 1 wherein the (ii) monomer contain from about 0.002 to about 0.010 equivalent per 100 g of the acrylic polymer.

3. The ultra-violet curable pressure sensitive adhesive of claim 1 wherein the (ii) monomer is a cycloaliphatic epoxide having the formula:

4. The ultra-violet curable pressure sensitive adhesive of claim 1 wherein the cycloaliphatic epoxide is: