Release coating for adhesive articles and method

• US 5,990,238 A
• Filed: 09/19/1997
• Issued: 11/23/1999
• Est. Priority Date: 09/19/1997
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Schneider, Hildegard M., DiZio, James P., Wong, Roy
• Primary Examiner(s): Lipman, Bernard
• Application Number:
  US08/934,263
• Time in Patent Office: 795 Days
• Field of Search: 525/60, 525/61, 525/326.7, 525/327.6, 525/329.4, 525/329.6, 525/329.8, 525/329.9, 525/330.4, 525/330.5, 525/331.5, 525/340, 525/343, 525/353, 525/367 , 525/369, 525/374
• US Class Current: 525/60
• CPC Class Codes: C08G 18/0823 containing carboxylate salt groups or groups forming them
• CPC Class Codes: C08G 18/341 Dicarboxylic acids, esters of polycarboxylic acids containing two carboxylic acid groups
• CPC Class Codes: C08G 18/6212 Polymers of alkenylalcohols; Acetals thereof; Oxyalkylation products thereof
• CPC Class Codes: C08G 18/71 Monoisocyanates or monoisothiocyanates

Abstract

A polymer includes an ethylene-containing backbone having substituents attached thereto, wherein the substituents include a urethane linked nitrogen-bonded hydrocarbon side chain having about 5 carbon atoms or more in length and a terminal methyl group; and an oxygen linked water solubilizing group. The polymer is particularly useful in a release coating composition and is suitable for forming films from aqueous dispersions thereof, organic solvent dispersions thereof, or mixtures thereof.

Claims

1. A release coating composition comprising a polymer comprising:

a polyethylene backbone having substituents attached thereto, wherein the substituents comprise;

a urethane linked nitrogen-bonded hydrocarbon side chain having about 5 carbon atoms or more in length and a terminal methyl group; and

an oxygen linked water solubilizing group.

2. The release coating composition of claim 1 wherein the substituents further comprise hydrogen;

a hydroxyl group;

a halide;

an alkylene, an alkenylene, an alkynylene, an arylene group, or mixtures thereof, having a terminal hydroxyl group;

##STR25## --O--R⁵ ;

--R⁶ ;

or mixtures thereof;

wherein each R⁴, R⁵, and R⁶ is independently selected from the group of an aliphatic group, an aromatic group, and mixtures thereof.

3. The release coating composition of claim 1 wherein the water solubilizing group comprises an anionic group comprising an anion selected from the group of --OSO₂ O^- ;

--SO₂ O^-, --CO₂^-, (--O)₂ P(O)O^-, --OP(O)(O^-)₂, --P(O)(O^-)₂, --P(O^-)₂, and --PO(O^-)₂.

4. The release coating composition of claim 1 wherein the water solubilizing group comprises a cation selected from the group of --NH(R⁸)₂⁺ and --N(R⁸)₃⁺, wherein R⁸ is selected from the group of a phenyl group;

a cycloaliphatic group; and

a straight or branched aliphatic group having about 1 to about 12 carbon atoms.

5. The release coating composition of claim 1 wherein the water solubilizing group comprises an acidic group capable of forming an anionic species.

6. The release coating composition of claim 1 further comprising an organic solvent selected from the group of an aromatic hydrocarbon, an ester, an aliphatic hydrocarbon, an alcohol, a ketone, and mixtures thereof.

7. The release coating composition of claim 1 further comprising an optional additive.

8. The release coating composition of claim 7 wherein the optional additive is selected from the group of a crosslinker;

a defoamer;

a flow and leveling agent;

a colorant;

an adhesion promoter;

a plasticizer;

a thixotropic agent;

a rheology modifier;

a film former;

a biocide/anti-fungal agent;

a corrosion inhibitor;

an antioxidant;

a surfactant/emulsifier;

an extender; and

mixtures thereof.

9. The release coating composition of claim 8 wherein the extender comprises a thickener, a polymeric emulsion, or mixtures thereof.

10. The release coating composition of claim 1 further comprising water or a mixture of water and one or more organic solvents.

11. A release coating composition comprising a polymer comprising:

a vinyl-derived backbone having substituents attached thereto, wherein the substituents comprise;

a urethane linked nitrogen-bonded hydrocarbon side chain having about 5 carbon atoms or more in length and a terminal alkyl group; and

an oxygen linked water solubilizing group;

wherein the release coating composition comprises about 0.5% by weight or less of a surfactant.

12. The release coating composition of claim 11 wherein the vinyl-derived backbone is formed from one or more precursor compounds selected from the group of ethylene, vinyl halides, vinyl ethers, vinyl esters, acrylic esters, methacrylic esters, (meth)acrylic acid, amides, aromatic vinyl compounds, heterocyclic vinyl monomers, allyl compounds, esters and half esters of diacids, and mixtures thereof.

13. The release coating composition of claim 12 wherein the vinyl-derived backbone is selected from the group of partially or fully hydrolyzed polyvinyl acetate, partially or fully hydrolyzed ethylene/vinyl acetate, and mixtures thereof.

14. The release coating composition of claim 11 wherein the water solubilizing group comprises an anionic group comprising an anion selected from the group of --OSO₂ O^-, --SO₂ O^-, --CO₂^-, (--O)₂ P(O)O^- ;

--OP(O)(O^-)₂, --P(O)(O^-)₂, --P(O^-)₂, and --PO(O^-)₂.

15. The release coating composition of claim 11 wherein the water solubilizing group comprises a cation selected from the group of --NH(R⁸)₂⁺ and --N(R⁸)₃⁺, wherein R⁸ is selected from the group of a phenyl group;

a cycloaliphatic group; and

a straight or branched aliphatic group having about 1 to about 12 carbon atoms.

16. The release coating composition of claim 11 further comprising an organic solvent selected from the group of an aromatic hydrocarbon, an ester, an aliphatic hydrocarbon, an alcohol, a ketone, and mixtures thereof.

17. The release coating composition of claim 11 further comprising an optional additive.

18. The release coating composition of claim 17 wherein the optional additive comprises an extender.

19. A composition for forming a release coating, wherein the composition comprises a polymer formed by combining a polymeric backbone component with an isocyanate-containing hydrocarbon having about 5 carbon atoms or more and a terminal methyl group and a water solubilizing compound.

20. The release coating composition of claim 19 wherein the water solubilizing compound is capable of forming an anionic water solubilizing group comprising an anion selected from the group of --OSO₂ O^-, --SO₂ O^-, --CO₂^-, (--O)₂ P(O)O^-, --OP(O)(O^-)₂, --P(O)(O^-)₂, --P(O^-)₂, and --PO(O^-)₂.

21. The release coating composition of claim 19 wherein the water solubilizing compound is capable of forming a cationic water solubilizing group comprising a cation selected from the group of --NH(R⁸)₂⁺ and --N(R⁸)₃⁺, wherein R⁸ is selected from the group of a phenyl group;

a cycloaliphatic group; and

a straight or branched aliphatic group having about 1 to about 12 carbon atoms.

22. A release coating composition comprising a polymer comprising units of the following formula:

##STR26## wherein each R¹ is independently selected from the group of hydrogen and an aliphatic group; and

each R is independently selected from the group of X;

a urethane-linked hydrocarbon group of the formula;

##STR27## wherein q is about 5 or more; and

an oxygen linked water solubilizing group of the formula;

##STR28## wherein each R³ is independently a divalent organic linking group and m is 0 or 1; and

the X moiety is selected from the group of hydrogen;

a hydroxyl group;

a halide;

an alkylene, an alkenylene, an arylene group, and mixtures thereof having a terminal hydroxyl group;

##STR29## --O--R⁵ ;

or --R⁶ ;

wherein each R⁴, R⁵, and R⁶ is independently selected from the group of an aliphatic group, an aromatic group, or mixtures thereof; and

further wherein each Y moiety independently comprises a functionality capable of being ionized or is the ionized form thereof;

with the proviso that the polymer contains at least one each of the urethane linked hydrocarbon group and the oxygen linked water solubilizing group.

23. A release coating composition comprising a polymer comprising:

##STR30## wherein each R¹ is independently selected from the group of hydrogen and an aliphatic group;

each X is independently selected from the group of hydrogen;

a hydroxyl group;

a halide;

an alkylene, an alkenylene, an arylene group, or mixtures thereof, having a terminal hydroxyl group;

##STR31## --O--R⁵ ; and

--R⁶ ;

wherein each R⁴, R⁵, and R⁶ is independently selected from the group of an aliphatic group, an aromatic group, and mixtures thereof, and wherein each R³ is independently a divalent organic linking group and each Y is independently a functionality capable of being ionized or is the ionized form thereof; and

further wherein q is about 5 or more;

m is 0 or 1;

x is about 0 to about 70;

y is about 5 to about 95; and

z is about 5 to about 50.

24. The release coating composition of claim 23 further comprising an organic solvent selected from the group of an aromatic hydrocarbon, an ester, an aliphatic hydrocarbon, an alcohol, a ketone, and mixtures thereof.

25. The release coating composition of claim 23 further comprising an optional additive.

26. The release coating composition of claim 25 wherein the optional additive comprises an extender.

27. A polymer comprising:

a vinyl-derived backbone having substituents attached thereto;

wherein the substituents comprise;

a urethane linked nitrogen-bonded hydrocarbon side chain having about 5 carbon atoms or more in length and a terminal alkyl group; and

an oxygen linked water solubilizing group.

28. The polymer of claim 27 wherein the vinyl-derived backbone is formed from one or more precursors selected from the group of ethylene, vinyl halides, vinyl ethers, vinyl esters, acrylic esters, methacrylic esters, (meth)acrylic acid, amides, aromatic vinyl compounds, heterocyclic vinyl monomers, allyl compounds, esters and half esters of diacids, and mixtures thereof.

29. The polymer claim 28 wherein the vinyl-derived backbone is selected from the group of partially or fully hydrolyzed polyvinyl acetate, partially or fully hydrolyzed ethylene vinyl acetate, and mixtures thereof.

30. The polymer of claim 28 wherein the water solubilizing group comprises an anionic group comprising an anion selected from the group of --OSO₂ O^-, --SO₂ O^-, --CO₂^-, (--O)₂ P(O)O^-, --OP(O)(O^-)₂, --P(O)(O^-)₂, --P(O^-)₂, and --PO(O^-)₂.

31. The polymer of claim 28 wherein the water solubilizing group comprises a cation selected from the group of --NH(R⁸)₂⁺ and --N(R⁸)₃⁺, wherein R⁸ is selected from the group of a phenyl group;

a cycloaliphatic group; and

a straight or branched aliphatic group having about 1 to about 12 carbon atoms.

32. A method for making a polymer comprising the steps of:

admixing a polymeric backbone component and at least one organic solvent;

adding an isocyanate-containing hydrocarbon having at least about 5 carbon atoms in length and a terminal methyl group to the admixture to modify the polymeric backbone component; and

adding a water solubilizing compound to the admixture to modify the polymeric backbone component.

33. The method of claim 32 wherein the polymeric backbone component is formed from one or more precursors selected from the group of ethylene, vinyl halides, vinyl ethers, vinyl esters, acrylic esters, methacrylic esters, (meth)acrylic acid, amides, aromatic vinyl compounds, heterocyclic vinyl monomers, allyl compounds, esters and half esters of diacids, and mixtures thereof.

34. The method of claim 33 wherein the polymeric backbone component is selected from the group of partially or fully hydrolyzed polyvinyl acetate, partially or fully hydrolyzed ethylene vinyl acetate, and mixtures thereof.

35. The method of claim 32 wherein the water solubilizing compound is capable of forming an anionic group comprising an anion selected from the group of --OSO₂ O^-, --SO₂ O^-, --CO₂^-, (--O)₂ P(O)O^- ;

--OP(O)(O^-)₂, --P(O)(O^-)₂, --P(O^-)₂, and --PO(O^-)₂.

36. The method of claim 32 wherein the water solubilizing compound is capable of forming a cationic group comprising a cation selected from the group of --NH(R⁸)₂⁺ and --N(R⁸)₃⁺, wherein R⁸ is selected from the group of a phenyl group;

a cycloaliphatic group; and

a straight or branched aliphatic group having about 1 to about 12 carbon atoms.

37. The method of claim 32 wherein the water solubilizing compound is selected from the group of succinic anhydride, maleic anhydride, glutaric anhydride, phthalic anhydride, 2-sulfobenzoic acid cyclic anhydride, and mixtures thereof.

38. The method of claim 32 wherein the at least one organic solvent is selected from the group of an aromatic hydrocarbon, N-methyl-2-pyrrolidinone, dimethylformamide, diglyme, and mixtures thereof.

39. The method of claim 32 further comprising a step of adding an optional additive selected from the group of a crosslinker;

a defoamer;

a flow and leveling agent;

a colorant;

an adhesion promoter;

a plasticizer;

a thixotropic agent;

a rheology modifier;

a film former;

a biocide/anti-fungal agent;

a corrosion inhibitor;

an antioxidant;

a surfactant/emulsifier;

an extender; and

mixtures thereof.

40. The method of claim 39 wherein the extender comprises a thickener, a polymeric emulsion, or mixtures thereof.

41. The method of claim 32 further comprising the steps of:

adding a salt forming compound, a solvent, and water; and

removing a sufficient amount of the organic solvent to form an aqueous dispersion of the release coating composition.

42. The method of claim 41 wherein the salt forming compound is selected from the group of ammonia, ammonium hydroxide, trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, triethanolamine, diethanolamine, dimethylethanolamine, and mixtures thereof.

43. The method of claim 41 further comprising a step of adding an optional additive.

44. The method of claim 43 wherein the optional additive comprises an extender.

46. An article comprising two opposed major surfaces wherein at least one of the major surfaces is coated with a release coating composition comprising a polymer prepared by the method of claim 32.

47. An article comprising two opposed major surfaces wherein at least one of the major surfaces is coated with a release coating composition comprising a polymer prepared by the method of claim 41.

45. An article comprising:

a backing having a first major surface and a second major surface;

a pressure sensitive adhesive coated on the first major surface of the backing; and

a low adhesion backsize coated on the second major surface;

wherein the low adhesion backsize is formed from a release coating composition comprising a polymer comprising;

an ethylene-containing backbone having substituents attached thereto, wherein the substituents comprise;

a urethane linked nitrogen-bonded hydrocarbon side chain having about 5 carbon atoms or more in length and a terminal methyl group; and

an oxygen linked water solubilizing group.

48. A polymer comprising repeat units of the following formula:

##STR32## wherein each R¹ is independently selected from the group of hydrogen and an aliphatic group; and

each R is independently selected from the group of X;

a urethane-linked hydrocarbon group of the formula;

##STR33## wherein q is about 5 or more; and

an oxygen linked water solubilizing group of the formula;

##STR34## wherein the X moiety is selected from the group of hydrogen;

a hydroxyl group;

a halide;

an alkylene, an alkenylene, an arylene group, or mixtures thereof, having a terminal hydroxyl group;

##STR35## --O--R⁵ ;

or --R⁶ ;

wherein each R⁴, R⁵, and R⁶ is independently selected from the group of an aliphatic group, an aromatic group, and mixtures thereof, and further wherein each R³ is independently a divalent organic linking group, m is 0 or 1, and each Y moiety independently comprises a functionality capable of being ionized or is the ionized form thereof;

with the proviso that the polymer contains at least one each of the urethane linked hydrocarbon group and the oxygen linked water solubilizing group.

49. The polymer of claim 48 wherein the water solubilizing group comprises an anionic group comprising an anion selected from the group of --OSO₂ O^-, --SO₂ O^-, --CO₂^-, (--O)₂ P(O)O^-, --OP(O)(O^-)₂, --P(O)(O^-)₂, --P(O^-)₂, and --PO(O^-)₂.

50. The polymer of claim 48 wherein the water solubilizing group comprises a cation selected from the group of --NH(R⁸)₂⁺ and --N(R⁸)₃⁺, wherein R⁸ is selected from the group of a phenyl group;

a cycloaliphatic group; and

a straight or branched aliphatic group having about 1 to about 12 carbon atoms.

51. A polymer comprising:

##STR36## wherein each R¹ is independently selected from the group of hydrogen and an aliphatic group;

each X is independently selected from the group of a hydrogen;

a hydroxyl group;

a halide;

an alkylene, an alkenylene, an arylene group, or mixtures thereof, having a terminal hydroxyl group;

##STR37## --O--R⁵ ; and

--R⁶, wherein each R⁴, R⁵ and R⁶ is independently selected from the group of an aliphatic group, an aromatic group, and mixtures thereof; and

wherein each R³ is independently a divalent organic linking group and each Y is independently a functionality capable of being ionized or is the ionized form thereof; and

further wherein q is about 5 or more;

m is 0 or 1;

x is about 0 to about 70;

y is about 5 to about 95; and

z is about 5 to about 50.

52. The polymer of claim 51 wherein Y comprises an anion selected from the group of --OSO₂ O^-, --SO₂ O^-, --CO₂^-, (--O)₂ P(O)O^- ;

--OP(O)(O^-)₂, --P(O)(O^-)₂, --P(O^-)₂, and --PO(O^-)₂.

53. The polymer of claim 51 wherein Y comprises a cation selected from the group of --NH(R⁸)₂⁺ and --N(R⁸)₃⁺, wherein R⁸ is selected from the group of a phenyl group;

a cycloaliphatic group; and

a straight or branched aliphatic group having about 1 to about 12 carbon atoms.

54. An article comprising:

a porous backing having a first major surface and a second major surface;

a pressure sensitive adhesive coated on the first major surface of the backing; and

a low adhesion backsize coated on the second major surface;

wherein the low adhesion backsize is formed from a release coating composition comprising a polymer comprising;

an ethylene-containing backbone having substituents attached thereto, wherein the substituents comprise;

a urethane linked nitrogen-bonded hydrocarbon side chain having about 5 carbon atoms or more in length and a terminal methyl group; and

an oxygen linked water solubilizing group.

55. The article of claim 54 wherein the article comprises a medical tape.

56. The article of claim 54 wherein the pressure sensitive adhesive is hypoallergenic.