High refractive index pressure-sensitive adhesives

• US 6,663,978 B1
• Filed: 06/28/2000
• Issued: 12/16/2003
• Est. Priority Date: 06/28/2000
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Lu, Ying-Yuh, Moore, Cheryl L., Olson, David B., Williams, Todd R., Fong, Bettie C.
• Primary Examiner(s): HARLAN, ROBERT D
• Application Number:
  US09/605,500
• Time in Patent Office: 1,266 Days
• Field of Search: 428/523, 526/319, 526/326, 526/329.2
• US Class Current: 428/523
• CPC Class Codes: C08F 220/06 Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• CPC Class Codes: C08F 220/1804 C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
• CPC Class Codes: C08F 220/301 and one oxygen in the alcohol moiety
• CPC Class Codes: C09J 7/385 Acrylic polymers
• CPC Class Codes: Y10T 428/31938 Polymer of monoethylenically unsaturated hydrocarbon

Abstract

The present invention provides pressure-sensitive adhesives having a refractive index of at least 1.48. The pressure-sensitive adhesives comprise at least one monomer containing a substituted or an unsubstituted aromatic moiety.

Claims

1. An article comprising

a substrate;

a pressure-sensitive adhesive coated on the substrate, the pressure sensitive adhesive comprising an aromatic monomer in an amount of at least 20 parts per 100 parts of total monomer, the aromatic monomer having the following formula;

 

wherein;

Ar is an aromatic group which is unsubstituted or substituted with a substituent selected from the group consisting of Br_y and (R³)_z

wherein y represents the number of bromine substituents attached to the aromatic group and is an integer from 0 to 3;

R³ is a straight or branched alkyl of 2 to 12 carbons; and

z represents the number of R³ substituents attached to the aromatic ring and is an integer from 0 to 1,

provided that both y and z are not zero;

X is either oxygen or sulfur;

n is 0 to 3;

R¹ is an unsubstituted straight or branched alkyl linking group of 2 to 12 carbons; and

R² is either H or CH₃.

2. The substrate according to claim 1, wherein said substrate material is selected from the group consisting of paper, polypropylene, polyethylene, polyvinyl chloride, polyester, cellulose acetate, ethyl cellulose, cellulose triacetate, woven fabric, air-laid webs, metal, metallized polymeric film, and ceramic sheet material.

3. The substrate according to claim 1, wherein said coated substrate is selected from the group consisting of labels, tapes, signs, covers, and marking indices.

4. The article according to claim 1, wherein z is 1 and R³ is a straight or branched alkyl of 2 to 8 carbons.

5. The article according to claim 1, wherein Ar is a naphthyl group.

6. The article according to claim 1, wherein n is 0 or 1.

7. The article according to claim 1, wherein the refractive index of the pressure sensitive adhesive is at least 1.48.

8. The article according to claim 1, wherein the pressure sensitive adhesive further comprises at least one acrylic monomer selected from the group consisting of monomeric acrylic or methacrylic acid esters of a non-tertiary alkyl alcohol of about 1 to about 12 carbons.

9. The article according to claim 1, wherein the pressure sensitive adhesive further comprises at least one polar monomer copolymerizable with the aromatic monomer(s).

10. The article according to claim 1, wherein the pressure sensitive adhesive further comprises at least one acrylic monomer selected from the group consisting of monomeric acrylic or methacrylic acid esters of a non-tertiary alkyl alcohol of about 1 to about 12 carbons, and

at least one polar monomer copolymerizable with the aromatic monomer(s) and acrylic monomer(s).

11. The article according to claim 10, wherein the acrylic monomer is selected from the group consisting of monomeric acrylic or methacrylic acid esters of 1-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 1-methyl-1-butanol, 1-methyl-1-pentanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol, 2-ethyl-1-hexanol, 3,5,5-trimethyl-1-hexanol, 3-heptanol, 2-octanol, 1-decanol, 1-dodecanol, and mixtures thereof.

12. The article according to claim 11, wherein the polar monomer(s) are selected from the group consisting of ethylenically unsaturated carboxylic acids, ethylenically unsaturated sulfonic acids, ethylenically unsaturated phosphoric acids, acrylamides, N,N-dialkyl substituted acrylamides, N-vinyl lactams, and N,N-dialkylaminoalkyl acrylates, ethylenically unsaturated nitrites, and mixtures thereof.

13. The article according to claim 12, wherein the polar monomer(s) are selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, and mixtures thereof.

14. The article according to claim 1, wherein the aromatic monomer(s) are selected from the group consisting of 6-(4,6-dibromo-2-isopropyl phenoxy)-1-hexyl acrylate, 6-(4,6-dibromo-2-sec-butyl phenoxy)-1-hexyl acrylate, 2,6-dibromo-4-nonylphenyl acrylate, 2,6-dibromo-4-dodecyl phenyl acrylate, 2-(1-naphthyloxy)-1-ethyl acrylate, 2-(2-naphthyloxy)-1-ethyl acrylate, 6-(1-naphthyloxy)-1-hexyl acrylate, 6-(2-naphthyloxy)-1-hexyl acrylate, 8-(1-naphthyloxy)-1-octyl acrylate, 8-(2-naphthyloxy)-1-octyl acrylate, and phenoxy ethyl acrylate.

15. The article according to claim 10, wherein the pressure sensitive adhesive further comprises one or more monomers selected from the group consisting of vinyl esters, vinyl acetate, 2-hydroxyethyl acrylate, styrene, and mixtures thereof.

16. The article according to claim 1, wherein X is sulfur.

17. The article according to claim 1, wherein the aromatic monomer is 2-phenylthio-1-ethyl acrylate.

18. An article comprising

a substrate;

a pressure-sensitive adhesive coated on the substrate, the pressure sensitive adhesive having a refractive index of at least 1.48 and comprising an aromatic monomer of the following formula;

 

wherein;

Ar is an aromatic group which is unsubstituted or substituted with a substituent selected from the group consisting of Br_y and (R³)_z

wherein y represents the number of bromine substituents attached to the aromatic group and is an integer from 0 to 3;

R³ is a straight or branched alkyl of 2 to 12 carbons; and

z represents the number of R³ substituents attached to the aromatic ring and is an integer from 0 to 1,

provided that both y and z are not zero;

X is either oxygen or sulfur;

n is 0to 3;

R¹ is an unsubstituted straight or branched alkyl linking group of 2 to 12 carbons; and

R² is either H or CH₃.

19. The article according to claim 18, wherein z is 1 and R³ is a straight or branched alkyl of 2 to 8 carbons.

20. The article according to claim 18, wherein Ar is a naphthyl group.

21. The article according to claim 18, wherein n is 0 or 1.

22. The article according to claim 18, wherein the refractive index of the pressure sensitive adhesive is at least 1.50.

23. The article according to claim 18, wherein the pressure sensitive adhesive further comprises at least one acrylic monomer selected from the group consisting of monomeric acrylic or methacrylic acid esters of a non-tertiary alkyl alcohol of about 1 to about 12 carbons.

24. The article according to claim 18, wherein the pressure sensitive adhesive further comprises at least one polar monomer copolymerizable with the aromatic monomer(s).

25. The article according to claim 18, wherein the pressure sensitive adhesive further comprises at least one acrylic monomer selected from the group consisting of monomeric acrylic or methacrylic acid esters of a non-tertiary alkyl alcohol of about 1 to about 12 carbons, and

at least one polar monomer copolymerizable with the aromatic monomer(s) and acrylic monomer(s).

26. The article according to claim 25, wherein the acrylic monomer is selected from the group consisting of monomeric acrylic or methacrylic acid esters of 1-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 1-methyl-1-butanol, 1-methyl-1-pentanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol, 2-ethyl-1-hexanol, 3,5,5-trimethyl-1-hexanol, 3-heptanol, 2-octanol, 1-decanol, 1-dodecanol, and mixtures thereof.

27. The article according to claim 26, wherein the polar monomer(s) are selected from the group consisting of ethylenically unsaturated carboxylic acids, ethylenically unsaturated sulfonic acids, ethylenically unsaturated phosphoric acids, acrylamides, N,N-dialkyl substituted acrylamides, N-vinyl lactams, and N,N-dialkylaminoalkyl acrylates, ethylenically unsaturated nitriles, and mixtures thereof.

28. The article according to claim 27, wherein the polar monomer(s) are selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, and mixtures thereof.

29. The article according to claim 18, wherein the aromatic monomer(s) are selected from the group consisting of 6-(4,6-dibromo-2-isopropyl phenoxy)-1-hexyl acrylate, 6-(4,6-dibromo-2-sec-butyl phenoxy)-1-hexyl acrylate, 2,6-dibromo-4-nonylphenyl acrylate, 2,6-dibromo-4-dodecyl phenyl acrylate, 2-(1-naphthyloxy)-1-ethyl acrylate, 2-(2-naphthyloxy)-1-ethyl acrylate, 6-(1-naphthyloxy)-1-hexyl acrylate, 6-(2-naphthyloxy)-1-hexyl acrylate, 8-(1-naphthyloxy)-1-octyl acrylate, 8-(2-naphthyloxy)-1-octyl acrylate, and phenoxy ethyl acrylate.

30. The article according to claim 25, wherein the pressure sensitive adhesive further comprises one or more monomers selected from the group consisting of vinyl esters, vinyl acetate, 2-hydroxyethyl acrylate, styrene, and mixtures thereof.

31. The article according to claim 18, wherein X is sulfur.

32. The article according to claim 18, wherein the aromatic monomer is 2-phenylthio-1-ethyl acrylate.

33. An article comprising

a substrate;

a pressure-sensitive adhesive coated on the substrate, the pressure sensitive adhesive comprising an aromatic monomer of the following formula;

 

wherein;

Ar is selected from i) substituted or unsubstituted naphthyl and ii) an aromatic group which is substituted with a substituent selected from the group consisting of Br_y and (R³)_z

wherein y represents the number of bromine substituents attached to the aromatic group and is an integer from 0 to 3;

R³ is a straight or branched alkyl of 2 to 12 carbons; and

z represents the number of R³ substituents attached to the aromatic ring and is an integer from 0 to 1,

provided that both y and z are not zero;

X is either oxygen or sulfur;

n is 0to 3;

R¹ is an unsubstituted straight or branched alkyl linking group of 2 to 12 carbons; and

R² is either H or CH₃.

34. The article according to claim 33, wherein z is 1 and R³ is a straight or branched alkyl of 2 to 8 carbons.

35. The article according to claim 33, wherein Ar is a naphthyl group.

36. The article according to claim 33, wherein n is 0 or 1.

37. The article according to claim 33, wherein the refractive index of the pressure sensitive adhesive is at least 1.48.

38. The article according to claim 33, wherein the pressure sensitive adhesive further comprises at least one acrylic monomer selected from the group consisting of monomeric acrylic or methacrylic acid esters of a non-tertiary alkyl alcohol of about 1 to about 12 carbons.

39. The article according to claim 33, wherein the pressure sensitive adhesive further comprises at least one polar monomer copolymerizable with the aromatic monomer(s).

40. The article according to claim 33, wherein the pressure sensitive adhesive further comprises at least one acrylic monomer selected from the group consisting of monomeric acrylic or methacrylic acid esters of a non-tertiary alkyl alcohol of about 1 to about 12 carbons, and

at least one polar monomer copolymerizable with the aromatic monomer(s) and acrylic monomer(s).

41. The article according to claim 40, wherein the acrylic monomer is selected from the group consisting of monomeric acrylic or methacrylic acid esters of 1-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 1-methyl-1-butanol, 1-methyl-1-pentanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol, 2-ethyl-1-hexanol, 3,5,5-trimethyl-1-hexanol, 3-heptanol, 2-octanol, 1-decanol, 1-dodecanol, and mixtures thereof.

42. The article according to claim 41, wherein the polar monomer(s) are selected from the group consisting of ethylenically unsaturated carboxylic acids, ethylenically unsaturated sulfonic acids, ethylenically unsaturated phosphoric acids, acrylamides, N,N-dialkyl substituted acrylamides, N-vinyl lactams, and N,N-dialkylaminoalkyl acrylates, ethylenically unsaturated nitrites, and mixtures thereof.

43. The article according to claim 42, wherein the polar monomer(s) are selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, and mixtures thereof.

44. The article according to claim 33, wherein the aromatic monomer(s) are selected from the group consisting of 6-(4,6-dibromo-2-isopropyl phenoxy)-1-hexyl acrylate, 6-(4,6-dibromo-2-sec-butyl phenoxy)-1-hexyl acrylate, 2,6-dibromo-4-nonylphenyl acrylate, 2,6-dibromo-4-dodecyl phenyl acrylate, 2-(1-naphthyloxy)-1-ethyl acrylate, 2-(2-naphthyloxy)-1-ethyl acrylate, 6-(1-naphthyloxy)-1-hexyl acrylate, 6-(2-naphthyloxy)-1-hexyl acrylate, 8-(1-naphthyloxy)-1-octyl acrylate, and 8-(2-naphthyloxy)-1-octyl acrylate.

45. The article according to claim 40, wherein the pressure sensitive adhesive further comprises one or more monomers selected from the group consisting of vinyl esters, vinyl acetate, 2-hydroxyethyl acrylate, styrene, and mixtures thereof.

46. The article according to claim 33, wherein X is sulfur.

47. The article according to claim 33, wherein the aromatic monomer is 2-phenylthio-1-ethyl acrylate.