Ultraviolet radiation curable pressure sensitive acrylic adhesive

• US 8,735,506 B2
• Filed: 03/31/2010
• Issued: 05/27/2014
• Est. Priority Date: 04/03/2009
• Status: Active Grant

• Current Assignee: Arkema France (Arkema)
• Original Assignee: Ashland Licensing and Intellectual Property Llc
• Inventors: Hammond, Terry E., Hu, Xiaochuan
• Primary Examiner(s): Leonard, Michael L
• Application Number:
  US12/751,190
• Publication Number:
  US 20100255239A1
• Time in Patent Office: 1,518 Days
• Field of Search: 525/455, 156/330.9, 156/331.1, 156/331.7, 156/358, 522/90, 522/92, 522/96, 522/97, 522/98
• US Class Current: 525/455
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29C 65/1406 Ultraviolet [UV] radiation
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/4825 Pressure sensitive adhesives
• CPC Class Codes: B29C 65/4845 Radiation curing adhesives, e.g. UV light curing adhesives
• CPC Class Codes: B29C 65/4865 containing additives C09J11/00 and subgroups take precedence
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/065 HDPE, i.e. high density polyethylene
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B32B 2037/1253 curable adhesive
• CPC Class Codes: B32B 2250/02 2 layers
• CPC Class Codes: B32B 2255/26 Polymeric coating
• CPC Class Codes: B32B 2310/0831 using UV radiation
• CPC Class Codes: B32B 2405/00 Adhesive articles, e.g. adhesive tapes labels B32B2519/00
• CPC Class Codes: B32B 37/1284 Application of adhesive
• CPC Class Codes: B32B 38/0008 Electrical discharge treatment, e.g. corona, plasma treatment; wave energy or particle radiation heat treatment B32B38/0036
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08F 2/48 by ultraviolet or visible light
• CPC Class Codes: C08F 220/1808 C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate
• CPC Class Codes: C08F 2800/20 as weight or mass percentages
• CPC Class Codes: C08F 2810/20 : leading to a crosslinking, either explicitly or inherently
• CPC Class Codes: C08F 8/00 : Chemical modification by after-treatment graft polymers, block polymers, crosslinking with unsaturated monomers or with polymers C08F251/00 - C08F299/00; of conjugated diene rubbers C08C
• CPC Class Codes: C08F 8/30 : Introducing nitrogen atoms or nitrogen-containing groups
• CPC Class Codes: C08G 18/62 : Polymers of compounds having carbon-to-carbon double bonds
• CPC Class Codes: C08G 18/6229 : Polymers of hydroxy groups containing esters of acrylic or methacrylic acid with aliphatic polyalcohols
• CPC Class Codes: C08G 18/6254 : Polymers of alpha-beta ethylenically unsaturated carboxylic acids and of esters of these acids containing hydroxy groups
• CPC Class Codes: C08G 18/755 : and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
• CPC Class Codes: C08G 18/8175 : with esters of acrylic or alkylacrylic acid having only one group containing active hydrogen
• CPC Class Codes: C09J 133/066 : containing -OH groups
• 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 175/16 : having terminal carbon-to-carbon unsaturated bonds
• CPC Class Codes: C09J 2301/302 : the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: C09J 2301/416 : use of irradiation
• CPC Class Codes: C09J 5/00 : Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
• CPC Class Codes: Y10T 428/1462 : Polymer derived from material having at least one acrylic or alkacrylic group or the nitrile or amide derivative thereof [e.g., acrylamide, acrylate ester, etc.]
• CPC Class Codes: Y10T 428/31551 : Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]

Abstract

A process for making UV curable pressure sensitive adhesive compositions by derivatizing an acrylic polymer with a derivatizing agent prepared from a hydroxy-functional acrylate monomer and a diisocyanate. The derivatizing agent typically has a ratio of hydroxy-functional acrylate monomer to diisocyanate greater than about 1:1. Also disclosed are UV curable pressure sensitive adhesives made with the derivatizing agent and methods for adhering substrates with pressure sensitive adhesive compositions.

Claims

1. A process for making an ultraviolet (“

UV”

) curable pressure sensitive adhesive composition comprising the step of derivatizing an acrylic polymer with about 2% to about 9% by weight solids of a derivatizing agent prepared from a hydroxy-functional acrylate monomer and a diisocyanate selected from the group consisting of isophorone diisocyanate, toluene diisocyanate and combinations thereof wherein the derivatizing agent has a ratio of hydroxy-functional acrylate monomer to diisocyanate of about 1.05;

1 to about 1.5;

1.

2. The process of claim 1 wherein the ratio is about 1.1:

1 to about 1.2;

1.

3. The process of claim 1 wherein the acrylic polymer has a molecular weight of about 40,000 to about 100,000.

4. The process of claim 1 wherein the acrylic polymer comprises a monomer selected from the group consisting of 2-ethylhexyl acrylate, iso-octyl acrylate, iso-decyl acrylate, lauryl acrylate, n-butyl acrylate and combinations thereof.

5. The process of claim 1 wherein the acrylic polymer comprises a monomer selected from the group consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, styrene, vinyl acetate and combinations thereof.

6. The process of claim 1 wherein the acrylic polymer comprises at least one backbone hydroxy-functional monomer.

7. The process of claim 6 wherein the backbone hydroxy-functional monomer is selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate and combinations thereof.

8. The process of claim 1 wherein the acrylic polymer comprises a functional monomer selected from the group consisting of acrylic acid, methacrylic acid, maleic anhydride, glycidyl methacrylate, N-vinyl pyrrolidone, N-vinyl caprolactam, acrylamide and combinations thereof.

9. The process of claim 1 wherein the hydroxy-functional acrylate monomer is selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, caprolactone acrylate, and combinations thereof.