Polymer, polymer microfiber, polymer nanofiber and applications including filter structures

• US 7,179,317 B2
• Filed: 07/19/2004
• Issued: 02/20/2007
• Est. Priority Date: 09/05/2000
• Status: Expired due to Term

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Chung, Hoo Y., Gogins, Mark A., Weik, Thomas M., Crofoot, Douglas G., Hall, John R. B.
• Primary Examiner(s): Greene; Jason M.
• Application Number:
  US10/894,848
• Publication Number:
  US 20070012007A1
• Time in Patent Office: 946 Days
• Field of Search: 428/357, 428/401, 428/903, 442/36, 442/340, 442/351, 553/853, 554/82, 554/86, 554/87, 554/98, 555/02, 555/27, 555/28
• US Class Current: 55/528
• CPC Class Codes: B01D 2239/025 comprising nanofibres apparatus incorporating such gas filtering material see B01D46/546
• CPC Class Codes: B01D 2239/0428 Rendering the filter material hydrophobic
• CPC Class Codes: B01D 2239/0492 on fibres
• CPC Class Codes: B01D 2239/0613 Woven
• CPC Class Codes: B01D 2239/0618 Non-woven
• CPC Class Codes: B01D 2239/0627 Spun-bonded
• CPC Class Codes: B01D 2239/064 The fibres being mixed
• CPC Class Codes: B01D 2239/065 More than one layer present in the filtering material apparatus incorporating such gas filtering material B01D2275/10
• CPC Class Codes: B01D 2239/0654 Support layers
• CPC Class Codes: B01D 2239/1233 Fibre diameter
• CPC Class Codes: B01D 2239/1258 Permeability
• CPC Class Codes: B01D 2275/10 Multiple layers
• CPC Class Codes: B01D 39/04 Organic material, e.g. cellulose, cotton
• CPC Class Codes: B01D 39/086 of inorganic material
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 39/163 sintered or bonded
• CPC Class Codes: B01D 39/18 the material being cellulose or derivatives thereof cork or peat B01D39/1646 ; making filter paper D21F11/14
• CPC Class Codes: B01D 46/0001 Making filtering elements
• CPC Class Codes: B01D 46/02 Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
• CPC Class Codes: B01D 46/10 Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
• CPC Class Codes: B01D 46/2411 : Filter cartridges
• CPC Class Codes: B01D 46/521 : using folded, pleated material
• CPC Class Codes: B01D 46/523 : with means for maintaining spacing between the pleats or folds
• CPC Class Codes: B01D 46/546 : using nano- or microfibres
• CPC Class Codes: C08L 65/00 : Compositions of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C08L7/00 - C08L57/00, C08L61/00 take precedence; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 77/00 : Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: D01D 5/0007 : Electro-spinning non-woven fabrics produced by electro-spinning D04H1/728
• CPC Class Codes: D01D 5/003 : the material being a polymer solution or dispersion D01D5/0053 takes precedence
• CPC Class Codes: D01D 5/0084 : Coating by electro-spinning, i.e. the electro-spun fibres are not removed from the collecting device but remain integral with it, e.g. coating of prostheses
• CPC Class Codes: D01F 1/10 : Other agents for modifying properties
• CPC Class Codes: D01F 6/80 : from copolyamides
• CPC Class Codes: D01F 6/90 : of polyamides
• CPC Class Codes: D01F 6/92 : of polyesters
• CPC Class Codes: D04H 3/02 : characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
• CPC Class Codes: Y10S 428/903 : Microfiber, less than 100 micron diameter
• CPC Class Codes: Y10T 428/1362 : Textile, fabric, cloth, or pile containing [e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.]
• CPC Class Codes: Y10T 428/24686 : Pleats or otherwise parallel adjacent folds
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/26 : Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/29 : Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/2915 : including textile, cloth or fabric
• CPC Class Codes: Y10T 428/2933 : Coated or with bond, impregnation or core
• CPC Class Codes: Y10T 428/2938 : Coating on discrete and individual rods, strands or filaments
• CPC Class Codes: Y10T 428/2967 : Synthetic resin or polymer
• CPC Class Codes: Y10T 428/2969 : Polyamide, polyimide or polyester
• CPC Class Codes: Y10T 428/298 : Physical dimension
• CPC Class Codes: Y10T 442/16 : Two or more nonwoven layers
• CPC Class Codes: Y10T 442/614 : Strand or fiber material specified as having microdimensions [i.e., microfiber]
• CPC Class Codes: Y10T 442/626 : Microfiber is synthetic polymer
• CPC Class Codes: Y10T 442/659 : Including an additional nonwoven fabric

Abstract

Disclosed are improved polymer materials. Also disclosed are fine fiber materials that can be made from the improved polymeric materials in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials.

Claims

1. A fine fiber comprising an addition polymer and about 2 to 25 wt. % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000 and an aromatic character, wherein the additive is miscible in the polymer, the fiber having a diameter of 0.01 to 2 microns, the fibers after exposure to air at 140°

F. and 100% humidity for 6 hours, at least 50% of the fiber remains substantially unchanged.

2. The fine fiber of claim 1 wherein the additive comprises a hydrophobic coating on the fine fiber surface.

3. The fine fiber of claim 2 wherein the hydrophobic coating comprises an oleophobic coating.

4. The fine fiber of claim 3 wherein the hydrophobic and oleophobic coating is formed on a fiber having a hydrophilic composition.

5. The fine fiber of claim 1 wherein the coating has a thickness of less than 100 Å

.

6. The fine fiber of claim 1 wherein the coating has a thickness of less than about 80 Å

.

7. The fine fiber of claim 1 wherein the coating has a thickness of less than 50 Å

.

8. The fine fiber of claim 1 wherein the additive comprises an oligomer comprising tertiary butyl phenol.

9. The fine fiber of claim 8 wherein the addition polymer is crosslinked with a crosslinking agent.

10. The fine fiber of claim 1 wherein the resin comprises bis-phenol A.

11. The fine fiber of claim 9 wherein the crosslinking agent comprises a polymer comprising repeating units of acrylic acid, the polymer having a molecular weight of about 1000 to 5000.

12. The fine fiber of claim 11 wherein the polymer comprises an acrylic acid copolymer having a molecular weight of 1000 to 5000.

13. The fine fiber of claim 9 wherein the crosslinking agent comprises a melamine formaldehyde resin.

14. The fine fiber of claim 9 wherein the crosslinking agent comprises an aldehyde crosslinking agent substantially free of formaldehyde.

15. The fine fiber of claim 10 wherein the additive comprises an oligomer comprising:

16. The, fine fiber of claim 8 wherein the resin comprises an oligomer comprising dihydroxy biphenyl.

17. The, fine fiber of claim 16 wherein the additive comprises an oligomer comprising:

18. The fine fiber of claim 1 wherein the diameter of the fiber is about 0.1 to about 2 micron.

19. The fine fiber of claim 1 wherein the diameter of the fiber is about 0.1 to about 0.5 micron.

20. The fine fiber of claim 1 wherein the diameter of the fiber is about 0.05 to about 0.2 micron.

21. The fine fiber of claim 1 comprising a crosslinked polyvinylalcohol, the fiber having a diameter of about 0.01 to 2 microns.

22. The fine fiber of claim 21 wherein the crosslinking agent is present in an amount of about 5 to 50 wt % based on the polyvinylalcohol polymer.

53. The fine fiber of claim 9 wherein the crosslinking agent comprises a homopolymer comprising repeating units of acrylic acid, the polymer having a molecular weight of about 1000 to 5000 and an acidic catalyst.

23. A fine fiber comprising a condensation polymer, other than a copolymer of a cyclic lactam and a C_6-10 diamine monomer or a C_6-10 diacid monomer, and an additive composition having a molecular weight of about 500 to 3000;

the fiber having a diameter of 0.01 to 2 microns, the fibers after exposure to air at 140°

F. and 100% humidity for 6 hours, at least 50% of the fiber remains substantially unchanged.

24. The fine fiber of claim 23 wherein the additive comprises a hydrophobic coating on the fine fiber surface.

25. The fine fiber of claim 24 wherein the hydrophobic coating comprises an oleophobic coating.

26. The fine fiber of claim 25 wherein the hydrophobic and oleophobic coating is formed on a fiber having a hydrophilic composition.

27. The fine fiber of claim 24 wherein the coating has a thickness of less than about 100 Å

.

28. The fine fiber of claim 24 wherein the coating has a thickness of less than about 80 Å

.

29. The fine fiber of claim 24 wherein the coating has a thickness of less than 50 Å

.

30. The fine fiber of claim 24 wherein the condensation polymer comprises a polyalkylene terephthalate.

31. The fine fiber of claim 30 wherein the condensation polymer comprises a polyalkylene naphthalate.

32. The fine fiber of claim 30 wherein the condensation polymer comprises a polyethylene terephthalate.

33. The fine fiber of claim 24 wherein the condensation polymer comprises a nylon polymer comprising a homopolymer having repeating units derived from a cyclic lactam.

34. The fine fiber of claim 33 wherein the nylon polymer is combined with a second nylon polymer, the polymer differing in molecular weight or monomer composition.

35. The fine fiber of claim 34 wherein the second nylon polymer comprises a nylon copolymer.

36. The fine fiber of claim 34 wherein the polymers are treated to form a single polymeric composition as measured by a differential scanning calorimeter showing a single phase material.

37. The fine fiber of claim 36 wherein the copolymer and the second polymer are heat treated.

38. The fine fiber of claim 23 wherein the additive comprises an oligomer comprising tertiary butyl phenol linked.

39. The fine fiber of claim 38 wherein the additive comprises:

40. The fine fiber of claim 23 wherein the resin comprises bis-phenol A.

41. The fine fiber of claim 40 wherein the additive comprises:

42. The fine fiber of claim 23 wherein the resin comprises an oligomer comprising dihydroxy biphenyl.

43. The fine fiber of claim 42 wherein the additive comprises an oligomer comprising:

44. The fine fiber of claim 23 wherein the diameter of the fiber is about 0.1 to about 0.5 micron.

45. The fine fiber of claim 23 wherein the diameter of the fiber is about 1 to about 0.01 micron diameter.

46. The fine fiber composition of claim 23 wherein the fiber diameter is about 0.2 to 0.1 micron.

47. The fine fiber of claim 23 comprising a fiber having a diameter of about 0.1 to 0.5 micron, the fine fiber comprising the reaction product of an aldehyde reactant and a blend of a nylon 4,6 and a nylon 6,6.

48. The fine fiber of claim 47 wherein the fine fiber comprises the reaction product of an aldehyde reactant and a blend of a nylon 6 and a nylon 6,6 in the presence of a C_1-24 alcohol and water.

49. The fine fiber of claim 47 wherein the fine fiber comprises the reaction product of aldehyde reactant and a nylon 4,6.

50. The fine fiber of claim 49 wherein the reaction product of an aldehyde and a nylon 4,6 is conducted in the presence of alcohol and water.

51. The fine fiber of claim 47 wherein the fine fiber additionally comprises a copolymer of a cyclic lactam, a C_6-10 diamine monomer and a C_6-10 diacid monomer.

52. The fine fiber of claim 47 wherein the fine fiber additionally comprises a resinous additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character wherein the additive is miscible in the condensation polymer.

54. The fine fiber of claim 34 wherein the second nylon polymer comprises an alkoxy alkyl modified polyamide.

55. A fine fiber comprising a fiber having a diameter of about 0.01 to 0.5 micron, the fiber comprising a polymer comprising polyvinyl alcohol and a crosslinking agent.

56. The fine fiber of claim 55 wherein the polyvinylalcohol is crosslinked with about 1 to 40 wt % of the crosslinking agent.

57. The fine fiber of claim 56 wherein the crosslinking agent comprises a polymer comprising repeating units of acrylic acid, the polymer having a molecular weight of about 1000 to 5000.

58. The fine fiber of claim 56 wherein the polymer comprises an acrylic acid copolymer having a molecular weight of 1000 to 5000.

59. The fine fiber of claim 56 wherein the polymer comprises an acrylic acid homopolymer having a molecular weight of 1000 to 5000.

60. The, fine fiber composition of claim 56 wherein the crosslinked polyvinylalcohol is crosslinked using a melamine-formaldehyde resin having a molecular weight of about 1000 to 3000.

61. The fiber of claim 55 wherein the fine fiber comprises a blend of two polyvinyl alcohol polymers and has a diameter of 0.01 to 0.5 micron.

62. The fine fiber of claim 55 wherein the fine fiber has a diameter of 0.01 to 0.2 micron.

63. The fine fiber of claim 55 wherein the fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 16 hours.

64. The fine fiber of claim 55 wherein the polyvinyl alcohol is partially hydrolyzed.

65. The fine fiber of claim 55 wherein the polyvinyl alcohol is fully hydrolyzed.

66. The fine fiber of claim 65 wherein the fine fiber comprises about 0.1 to 40 wt % of the crosslinking agent.

67. The fine fiber of claim 66 wherein the crosslinking agent comprises urea formaldehyde, melamine formaldehyde, phenol formaldehyde, or mixtures thereof.

68. The fine fiber of claim 67 wherein the crosslinking agent comprises a dialdehyde, trialdehyde, tetraaldehyde, a diacid, a urethane reactant, epoxy reactant, or mixtures thereof.

69. The fine fiber of claim 55 comprising a layer having a thickness of less than about 30 microns.

70. The fine fiber of claim 69 comprising a layer having a thickness of less than about 20 microns.

71. A fine fiber comprising the reaction product of an addition polymer and a crosslinking agent, the fiber having a fiber size of about 0.01 to 0.5 micron wherein the fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 16 hours.

72. The fiber of claim 71 wherein the fine fiber comprises a blend of two polymers and has a diameter of 0.01 to 0.5 micron.

73. The fine fiber of claim 71 wherein the fine fiber has a diameter of 0.01 to 0.2 micron.

74. The fine fiber of claim 71 wherein the fine fiber comprises about 0.1 to 40 wt % of the crosslinking agent.

75. The fine fiber of claim 74 wherein the crosslinking agent comprises urea formaldehyde, melamine formaldehyde, phenol formaldehyde, or mixtures thereof.

76. The fine fiber of claim 74 wherein the crosslinking agent comprises a dialdehyde, trialdehyde, tetraaldehyde, a diacid, a urethane reactant, epoxy reactant, or mixtures thereof.

77. The fine fiber of claim 71 comprising a layer having a thickness of less than about 30 microns.

78. The fine fiber of claim 71 comprising a layer having a thickness of less than about 20 microns.

79. A fine fiber comprising the reaction product of a condensation polymer and a crosslinking agent, the fiber having a fiber size of about 0.01 to 0.5 micron wherein the fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 16 hours.

80. The fiber of claim 79 wherein the fine fiber comprises a blend of two polymers and has a diameter of 0.01 to 0.5 micron.

81. The fine fiber of claim 79 wherein the fine fiber has a diameter of 0.01 to 0.2 micron.

82. The fine fiber of claim 79 wherein the fine fiber comprises about 0.1 to 40 wt % of the crosslinking agent.

83. The fine fiber of claim 82 wherein the crosslinking agent comprises urea formaldehyde, melamine formaldehyde, phenol formaldehyde, or mixtures thereof.

84. The fine fiber of claim 82 wherein the crosslinking agent comprises a dialdehyde, trialdehyde, tetraaldehyde, a diacid, a urethane reactant, epoxy reactant, or mixtures thereof.

85. The fine fiber of claim 79 comprising a layer having a thickness of less than about 30 microns.

86. The fine fiber of claim 79 comprising a layer having a thickness of less than about 20 microns.

87. A fine fiber comprising the reaction product of a polyurethane polymer and a crosslinking agent, the fiber having a fiber size of about 0.01 to 0.5 micron wherein the fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 16 hours.

88. The fiber of claim 87 wherein the fine fiber comprises a blend of two polymers and has a diameter of 0.01 to 0.5 micron.

89. The fine fiber of claim 87 wherein the fine fiber has a diameter of 0.01 to 0.2 micron.

90. The fine fiber of claim 87 wherein the fine fiber comprises about 0.1 to 40 wt % of the crosslinking agent.

91. The fine fiber of claim 90 wherein the crosslinking agent comprises urea formaldehyde, melamine formaldehyde, phenol formaldehyde, or mixtures thereof.

92. The fine fiber of claim 90 wherein the crosslinking agent comprises a dialdehyde, trialdehyde, tetraaldehyde, a diacid, a urethane reactant, epoxy reactant, or mixtures thereof.

93. The fine fiber of claim 87 comprising a layer having a thickness of less than about 30 microns.

94. The fine fiber of claim 87 comprising a layer having a thickness of less than about 20 microns.

95. A fine fiber comprising the reaction product of a polyurethane polymer and a resinous additive comprising an oligomer having a molecular weight of about 500 to 3000 and an aromatic character wherein the additive miscible in the polymer, the fiber having a fiber size of about 0.01 to 0.5 micron wherein the fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 16 hours.

96. The fiber of claim 95 wherein the fine fiber comprises a blend of two polymers and has a diameter of 0.01 to 0.5 micron.

97. The fine fiber of claim 95 wherein the fine fiber has a diameter of 0.01 to 0.2 micron.

98. The fine fiber of claim 95 wherein the fine fiber comprises about 0.1 to 40 wt % of the crosslinking agent.

99. The fine fiber of claim 98 wherein the crosslinking agent comprises urea formaldehyde, melamine formaldehyde, phenol formaldehyde, or mixtures thereof.

100. The fine fiber of claim 98 wherein the crosslinking agent comprises a dialdehyde, trialdehyde, tetraaldehyde, a diacid, a urethane reactant, epoxy reactant, or mixtures thereof.

101. The fine fiber of claim 95 comprising a layer having a thickness of less than about 30 microns.

102. The fine fiber of claim 95 comprising a layer having a thickness of less than about 20 microns.