PRESSURE SENSITIVE ADHESIVE COMPRISING (METH) ACRYLIC POLYMER AND AMINO ACID CROSSLINKER

• US 20190316012A1
• Filed: 06/22/2016
• Published: 10/17/2019
• Est. Priority Date: 06/22/2015
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Yurt, Serkan, El-Hedok, Ibrahim A., Sakizadeh, Kumars, Seth, Jayshree
• Granted Patent: US 10,808,149 B2
• Time in Patent Office: Days
• CPC Class Codes: C08F 2/38 Polymerisation using regulators, e.g. chain terminating agents , e.g. telomerisation
• CPC Class Codes: C08F 2810/20 leading to a crosslinking, either explicitly or inherently
• CPC Class Codes: C08K 5/0025 Crosslinking or vulcanising agents; including accelerators
• CPC Class Codes: C08K 5/175 containing COOH-groups; Esters or salts thereof
• CPC Class Codes: C08L 2201/52 Aqueous emulsion or latex, e.g. containing polymers of a glass transition temperature (Tg) below 20°C
• 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 133/08 Homopolymers or copolymers of acrylic acid esters
• CPC Class Codes: C09J 133/10 Homopolymers or copolymers of methacrylic acid esters
• 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 133/26 Homopolymers or copolymers of acrylamide or methacrylamide
• CPC Class Codes: C09J 2433/005 in the release coating
• CPC Class Codes: C09J 4/00 Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16

Abstract

A pressure sensitive adhesive composition is described that comprises a (meth)acrylic polymer comprising polymerized units of (meth)acrylic ester monomer having a Tg less than 0° C. and ethylenically unsaturated monomer comprising a pendent functional group crosslinked with an amine or carboxylic acid group of at least one amino acid. Also described are aqueous pressure sensitive adhesive compositions, adhesive-coated articles, and methods.

Claims

1. A pressure sensitive adhesive composition comprising:

a (meth)acrylic polymer comprising polymerized units of (meth)acrylic ester monomer having a Tg less than 0°

C. and ethylenically unsaturated monomer comprising a pendent functional group crosslinked with an amine or carboxylic acid group of at least one amino acid.

2. The pressure sensitive adhesive composition of claim 1 wherein the pressure sensitive adhesive has a 180°

peel adhesion to stainless steel of at least 0.25, 0.5, 1 or 1.5 N/cm.

3. The pressure sensitive adhesive composition of claims 1-2 wherein the (meth)acrylic polymer comprises at least 50, 55, 60, 65, 70, 75, 80, 85, 90 or 95 wt-% of polymerized units of (meth)acrylic ester monomer(s) having a Tg less than 0°

C.

4. The pressure sensitive adhesive composition of claims 1-3 wherein the (meth)acrylic polymer comprises at least 50, 55, 60, 65, 70, 75, 80, 85, 90 or 95 wt-% of polymerized units of (meth)acrylic ester monomer(s) having an alkyl group with 6 to 20 carbon atoms.

5. The pressure sensitive adhesive composition of claims 1-4 wherein the composition further comprises tackifying resin.

6. The pressure sensitive adhesive composition of claims 1-5 wherein the pressure sensitive adhesive has a Tg no greater than −

10°

C.

7. The pressure sensitive adhesive composition of claims 1-6 wherein the pressure sensitive adhesive has a storage modulus of no greater than 0.3MPa at 25°

C. and 1 Hertz.

8. The pressure sensitive adhesive composition of claims 1-7 wherein the (meth)acrylic polymer comprises 1 to 15 wt-% of the polymerized units of the ethylenically unsaturated monomer comprising the pendent functional group.

9. The pressure sensitive adhesive composition of claims 1-8 wherein the pendent functional group is a carboxylic acid group, an amine group, an amide group, or a combination thereof.

10. The pressure sensitive adhesive composition of claims 1-9 wherein the amino acid comprises a side chain having a group selected from a hydrophobic group, a cyclic group, or a chain transfer agent group.

11. The pressure sensitive adhesive composition of claim 10 wherein the chain transfer agent group is selected from SH, SeH, or OH.

12. An article comprising the composition of claims 1-11 disposed on a substrate.

13. The article of claim 12 wherein the substrate is a release liner or backing.

15. The pressure sensitive adhesive composition of claim 14 wherein the pressure sensitive adhesive composition is further characterized by any one or combination of claims 1-11.

20. The method of claims 17-19 wherein the pressure sensitive adhesive composition is further characterized by any one or combination of claims 1-11.

21. The pressure sensitive adhesive composition of claims 1-9 wherein the amino acid comprises an electrically charged side chain.

22. An article comprising the composition of claim 21 disposed on a substrate.

23. The article of claim 22 wherein the substrate is a release liner or backing.

26. The pressure sensitive adhesive of any of the previous claim wherein the pressure sensitive adhesive has a shear strength after aging for 10 days at 120°

F. of greater than or equal to the initial shear strength.

14. A pressure sensitive adhesive composition comprising:

an aqueous phase;

a surfactant;

a (meth)acrylic polymer comprising polymerized units of (meth)acrylic ester monomer having a Tg less than 0°

C. and ethylenically unsaturated monomer comprising a pendent functional group wherein the pendent functional group forms an ionic or covalent bond with an amine or carboxylic acid group; and

an at least one amino acid crosslinker.

16. A pressure sensitive adhesive comprising the dried and crosslinked composition of claims 14-15.

24. The pressure sensitive adhesive composition of claim 14 wherein the pressure sensitive adhesive composition is further characterized by claim 21.

25. A pressure sensitive adhesive comprising the dried and crosslinked composition of claim 24.

17. A method of making a pressure sensitive adhesive composition comprising:

a) providing an aqueous pressure sensitive adhesive composition comprising a (meth)acrylic polymer comprising polymerized units of an ethylenically unsaturated monomer comprising a pendent functional group that forms an ionic or covalent bond with an amine or carboxylic acid group;

b) combining the aqueous pressure sensitive adhesive composition with an amino acid;

c) coating the aqueous pressure sensitive adhesive composition prepared in (b) onto a substrate;

e) drying the pressure sensitive adhesive composition and thereby crosslinking the pendent functional groups of the (meth)acrylic polymer with the amino acid.

18. A method of making a pressure sensitive adhesive composition comprising:

a) making a monomer mixture comprising

(i) low Tg (meth)acrylic monomer;

b) combining the monomer mixture with an aqueous phase comprising

(i) water,

(ii) an amino acid comprising a side chain having a chain transfer group selected from SH, SeH, or OH;

(iii) a surfactant, and

(iv) a free-radical initiator;

wherein monomer having a functional group that is reactive with an amine or carboxylic acid group is present in the monomer mixture, the aqueous phase, or a combination thereof;

c) polymerizing the monomers;

d) coating the aqueous pressure sensitive adhesive composition onto a substrate;

e) drying the pressure sensitive adhesive composition and thereby crosslinking the pendent functional groups of the (meth)acrylic polymer with the amino acid.

19. The method of claim 18 wherein the amino acid functions as a chain transfer agent and crosslinker.