Tie layers for PVA coatings

• US 20020110685A1
• Filed: 02/09/2001
• Published: 08/15/2002
• Est. Priority Date: 02/09/2001
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Horn, Robert W., Kallman, Guy M., Gilligan, Gregory E., Kausch, William L., Ebihara, Ikuko, Williams, Brian H.
• Application Number:
  US09/781,534
• Publication Number:
  US 20020110685A1
• Time in Patent Office: Days
• US Class Current: 428/336
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: C08J 2429/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/046 Forming abrasion-resistant coatings; Forming surface-hardening coatings
• CPC Class Codes: C08L 2666/14 Macromolecular compounds according to C08L59/00 - C08L87/00; Derivatives thereof
• CPC Class Codes: C08L 29/00 Compositions of 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 an alcohol, ether, aldehydo, ketonic, acetal or ketal radical; Compositions of hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C09D 129/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C09D 167/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C09D167/06 takes precedence
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers

Abstract

A tie layer film, comprising an admixture of polyvinyl alcohol and a water dispersible polyester, for bonding a support film to a topcoat layer. The preferred tie layer comprises a sulfopolyester, preferably including terephthalate groups or isophthalate groups. Most preferred are sulfopolyesters produced from ingredients comprising monomers selected from the group consisting of dimethyl 5-sodiosulfoisophthalate, dimethyl terephthalate, dimethyl isophthalate, ethylene glycol, and polycaprolactone diol. Alternatively the support film may be a layered film. In a preferred embodiment, the topcoat layer is formed from the same PVA material as the tie layer and the support film includes at least a portion of the same sulfopolyester as the tie layer. The tie layer is capable of maintaining the bond between the support film and the topcoat layer when heat stretched to a stretch ratio in the range of 2 times to 10 times its original dimension.

Claims

1. A coated film product formed by a process comprising the steps of:

a) providing an aqueous tie layer coating fluid, wherein said coating fluid comprises a polyvinyl alcohol and a water dispersible polyester;

b) applying said coating fluid to a support film to form a fluid layer on said support film;

c) drying said fluid layer to form a solid tie layer;

d) providing an aqueous topcoat coating fluid comprising polyvinyl alcohol;

e) applying said topcoat coating fluid to said tie layer to form a fluid layer; and

f) drying said polyvinyl alcohol fluid layer to form a solid topcoat layer.

2. The film product of claim 1, wherein said support film is a heat stretchable thermoplastic film.

3. The film product of claim 2, wherein the formation of said film product includes the further step of heating said film product and stretching it in a preferential direction.

4. The film product of claim 1, wherein said support film comprises at least two layers of different polymeric materials.

5. The film product of claim 1, wherein said support film comprises at least three layers of polymeric materials, wherein the materials that comprise each layer differ from the polymeric materials comprising adjacent layers.

6. The film product of claim 3, wherein said stretching elongates said film product to a stretch ratio in the range of 2 times its original dimension to 10 times its original dimension.

7. The film product of claim 3, wherein said stretching elongates said film product to a stretch ratio in the range of 6.5 times its original dimension to 7.0 times its original dimension.

8. The film product of claim 1, wherein said water dispersible polyester is a sulfopolyester.

9. The film product of claim 1, wherein said water dispersible polyester is a water resistant polyester.

10. The film product of claim 1, wherein said water dispersible polyester is a resistant to aqueous ionic solvents.

11. The film product of claim 8, wherein sulfopolyester includes terephthalate groups.

12. The film product of claim 8, wherein said sulfopolyester includes isophthalate groups.

13. The film product of claim 8 wherein said sulfopolyester is produced from ingredients comprising monomers selected from the group consisting of dimethly 5-sodiosulfoisophthalate, dimethyl terephthalate, dimethyl isophthalate, ethylene glycol, and polycaprolactone diol.

14. The film product of claim 1, wherein said polyvinyl alcohol has a degree of polymerization of at least 1000.

15. The film product of claim 1, wherein said polyvinyl alcohol has a degree of hydrolysis in the range of 96% to 99.9%.

16. The film product of claim 1, wherein said tie layer has a dried thickness in the range of 0.05 microns to 5.0 microns.

17. The film product of claim 1, wherein said tie layer has a dried thickness in the range of 1.0 microns to 5.0 microns.

18. The film product of claim 1, wherein said topcoat has a dried thickness in the range of 0.5 microns to 35.0 microns.

19. The film product of claim 1, wherein said dried topcoat has a thickness in the range of 5.0 to 15.0 microns.

20. The film product of claim 3, wherein said tie layer has a thickness of 0.01 to 0.7 microns after stretching.

21. The film product of claim 3, wherein said tie layer has a thickness of 0.15 to 0.4 microns after stretching.

22. The film product of claim 3, wherein said topcoat layer has a thickness of 0.1 to 5.0 microns after stretching.

23. The film product of claim 3, wherein said topcoat layer has a thickness of 0.7 to 2.2 microns after stretching.

24. The film product of claim 1, wherein the weight ratio of said polyester to said polyvinyl alcohol in said tie layer coating fluid is in the range of 90:

10 to 10;

90.

25. The film product of claim 1, wherein the weight ratio of said polyester to said polyvinyl alcohol in said tie layer coating fluid is in the range of 80:

20 to 20;

80.

26. The film product of claim 1, wherein the solids content of said tie layer is in the range of 2% to 15% solids.

27. The film product of claim 1, wherein the solids content of said tie layer coating fluid is in the range of 4% to 6% solids.

28. The film product of claim 1, wherein the solids content of said topcoat coating fluid is in the range of 5.0% to 15%.

29. The film product of claim 1, wherein the solids content of said topcoat coating fluid is in the range of 6% to 8%.

30. The film product of claim 1, wherein said support film produces a reflective polarizing effect.

31. A method of forming a film product, comprising the steps of:

a) providing an aqueous tie layer coating fluid, wherein said coating fluid comprises a polyvinyl alcohol and a water dispersible polyester;

b) applying said coating fluid to a support film to form a fluid layer on said support film;

c) drying said fluid layer to form a solid tie layer;

d) providing an aqueous topcoat coating fluid comprising polyvinyl alcohol;

e) applying said topcoat coating fluid to said tie layer to form a fluid layer; and

f) drying said polyvinyl alcohol fluid layer to form a solid topcoat layer.

32. The method of claim 31, wherein said support film is a heat stretchable thermoplastic film.

33. The method of claim 32, wherein the formation of said method includes the further step of heating said method and stretching it in a preferential direction.

34. The method of claim 31, wherein said support film comprises at least two layers of different polymeric materials.

35. The method of claim 31, wherein said support film comprises at least three layers of polymeric materials, wherein each layer differs from the polymeric materials comprising adjacent layers.

36. The method of claim 31, wherein said stretching elongates said method to a stretch ratio in the range of 2 times its original dimension to 10 times its original dimension.

37. The method of claim 33, wherein said stretching elongates said method to a stretch ratio in the range of 6.5 times its original dimension to 7.0 times its original dimension.

38. The method of claim 31, wherein said water dispersible polyester is a sulfopolyester.

39. The method of claim 31, wherein said water dispersible polyester is a water resistant polyester.

40. The method of claim 31, wherein said water dispersible polyester is a resistant to aqueous ionic solvents.

41. The method of claim 38, wherein sulfopolyester includes terephthalate groups.

42. The method of claim 38, wherein said sulfopolyester includes isophthalate groups.

43. The method of claim 38 wherein said sulfopolyester is produced from ingredients comprising monomers selected from the group consisting of dimethly 5-sodiosulfoisophthalate, dimethyl terephthalate, dimethyl isophthalate, ethylene glycol, and polycaprolactone diol.

44. The method of claim 31, wherein said polyvinyl alcohol has a degree of polymerization of at least 1000.

45. The method of claim 31, wherein said polyvinyl alcohol has a degree of hydrolysis in the range of 96% to 99.9%.

46. The method of claim 31, wherein said tie layer has a dried thickness in the range of 0.05 microns to 5.0 microns.

47. The method of claim 31, wherein said tie layer has a dried thickness in the range of 1.0 microns to 5.0 microns.

48. The method of claim 31, wherein said topcoat has a dried thickness in the range of 0.5 microns to 35.0 microns.

49. The method of claim 31, wherein said dried topcoat has a thickness in the range of 5.0 to 15.0 microns.

50. The method of claim 31, wherein said tie layer has a thickness of 0.01 to 0.7 microns after stretching.

51. The method of claim 33, wherein said tie layer has a thickness of 0.15 to 0.4 microns after stretching.

52. The method of claim 33, wherein said topcoat layer has a thickness of 0.1 to 5.0 microns after stretching.

53. The method of claim 33, wherein said topcoat layer has a thickness of 0.7 to 2.2 microns after stretching.

54. The method of claim 31, wherein the weight ratio of said polyester to said polyvinyl alcohol in said tie layer coating fluid is in the range of 90:

10 to 10;

90.

55. The method of claim 31, wherein the weight ratio of said polyester to said polyvinyl alcohol in said tie layer coating fluid is in the range of 80:

20 to 20;

80.

56. The method of claim 31, wherein the solids content of said tie layer is in the range of 2% to 15% solids.

57. The method of claim 31, wherein the solids content of said tie layer coating fluid is in the range of 4% to 6% solids.

58. The method of claim 31, wherein the solids content of said topcoat coating fluid is in the range of 5.0% to 15%.

59. The method of claim 31, wherein the solids content of said topcoat coating fluid is in the range of 6% to 8%.

60. The method of claim 31, wherein said support film produces a reflective polarizing effect.

61. A film product comprising:

a tie layer of an admixture of polyvinyl alcohol and a water dispersible polyester bonding a support film to a topcoat.

62. The film product of claim 61, wherein said support film is a heat stretchable thermoplastic film.

63. The film product of claim 62, wherein said film is stretched in a preferential direction at elevated temperature.

64. The film product of claim 61, wherein said support film comprises at least two layers of different polymeric materials.

65. The film product of claim 61, wherein said support film comprises at least three layers of polymeric materials, wherein each layer differs from the polymeric materials comprising adjacent layers.

66. The film product of claim 63, wherein said film product is stretched from 2 times its original dimension to 10 times its original dimension.

67. The film product of claim 63, wherein said film product is stretched from 6.5 times its original dimension to 7.0 times its original dimension.

68. The film product of claim 61, wherein said water dispersible polyester is a sulfopolyester.

69. The film product of claim 61, wherein said water dispersible polyester is a water resistant polyester.

70. The film product of claim 61, wherein said water dispersible polyester is a resistant to aqueous ionic solvents.

71. The film product of claim 68, wherein sulfopolyester includes terephthalate groups.

72. The film product of claim 68, wherein said sulfopolyester includes isophthalate groups.

73. The film product of claim 68, wherein said sulfopolyester is produced from ingredients comprising monomers selected from the group consisting of dimethly 5-sodiosulfoisophthalate, dimethyl terephthalate, dimethyl isophthalate, ethylene glycol, and polycaprolactone diol.

74. The film product of claim 61, wherein said polyvinyl alcohol has a degree of polymerization of at least 1000.

75. The film product of claim 61, wherein said polyvinyl alcohol has a degree of hydrolysis in the range of 96% to 99.9%.

76. The film product of claim 61, wherein said tie layer has a dried thickness in the range of 0.05 microns to 5.0 microns.

77. The film product of claim 61, wherein said tie layer has a dried thickness in the range of 1.0 microns to 5.0 microns.

78. The film product of claim 61, wherein said topcoat has a dried thickness in the range of 0.5 microns to 35.0 microns.

79. The film product of claim 61, wherein said dried topcoat has a thickness in the range of 5.0 to 15.0 microns.

80. The film product of claim 63, wherein said tie layer has a thickness of 0.01 to 0.7 microns after stretching.

81. The film product of claim 63, wherein said tie layer has a thickness of 0.15 to 0.4 microns after stretching.

82. The film product of claim 63, wherein said topcoat layer has a thickness of 0.1 to 5.0 microns after stretching.

83. The film product of claim 63, wherein said topcoat layer has a thickness of 0.7 to 2.2 microns after stretching.

84. The film product of claim 61, wherein the weight ratio of said polyester to said polyvinyl alcohol in said tie layer is in the range of 90:

10 to 10;

90.

85. The film product of claim 61, wherein the weight ratio of said polyester to said polyvinyl alcohol in said tie layer is in the range of 80:

20 to 20;

80.

86. The film product of claim 61, wherein said support film produces a reflective polarizing effect.

87. A tie layer film, comprising an admixture of a sulfonated polyester and PVA formed by blending a quantity of aqueous PVA into a water dispersion of said sulfonated polyester, applying said dispersion on a substrate, and drying said applied dispersion to form a tie layer film on said substrate, said tie layer film bonding a first substrate to a second substrate.

88. In a film system having a PVA layer and a polyester layer, the improvement comprising:

a tie layer bonding said PVA layer to said polyester layer, said tie layer comprising an admixture of a sulfonated polyester and PVA.

89. The tie layer of claim 88, wherein said PVA layer is formed from the same PVA as said tie layer.

90. The tie layer of claim 88, wherein said polyester layer is formed from the same sulfonated polyester as said tie layer.