Oxidation inhibition of carbon-carbon composites

Abstract

The disclosed invention relates to a method and a composition for treating a porous carbon-carbon composite with an oxidation inhibiting composition. The oxidation inhibiting composition comprises at least one phosphate glass. In one embodiment, the method optionally further comprises pretreating the composite with a pretreating composition prior to application of the oxidation inhibiting composition. Carbon-carbon composites treated by the foregoing method are disclosed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an optical micrograph at a magnification of 200× of the carbon-carbon composite treated in Example 85 wherein deposits from a pretreating composition (phosphate undercoating) are in the pores of the carbon-carbon composite and underlying a phosphate glass layer (glass barrier).

FIG. 2 is an SEM micrograph at a magnification of 500× of the carbon-carbon composite treated in Example 85.

Claims

1. A method of inhibiting oxidation of a carbon-carbon composite, comprising: (A) applying an oxidation inhibiting composition to a surface of the carbon-carbon composite, the oxidation inhibiting composition comprising at least one phosphate glass; and(B) heating the carbon-carbon composite from step (A) at a sufficient temperature to adhere the phosphate glass to the carbon-carbon composite.

2. The method of claim 1 wherein, prior to step (A), a pretreating composition is applied to the surface of the carbon-carbon composite, the pretreating composition comprising phosphoric acid and/or at least one acid phosphate salt, at least one aluminum salt, and optionally at least one additional salt, the carbon-carbon composite being porous, the pretreating composition penetrating at least some of the pores of the carbon-carbon composite.

3. The method of claim 1 wherein a barrier coating is applied to the surface of the carbon-carbon composite prior to step (A) or subsequent to step (B).

4. The method of claim 2 wherein a barrier coating is applied to the surface of the carbon-carbon composite prior to applying the pretreating composition.

5. The method of claim 1 wherein the oxidation inhibiting composition further comprise at least one carrier liquid.

6. The method of claim 1 wherein the oxidation inhibiting composition further comprises at least one ammonium phosphate.

7. The method of claim 1 wherein the oxidation inhibiting composition further comprises at least one ammonium phosphate, at least one metal phosphate, or a mixture thereof.

8. The method of claim 1 wherein the oxidation inhibiting composition further comprises at least one refractory compound.

9. The method of claim 1 wherein the phosphate glass comprises at least one borophosphate glass.

10. The method of claim 1 wherein the phosphate glass is derived from phosphorus pentoxide or a precursor thereof, one or more glass modifiers, one or more glass network modifiers, and optionally one or more additional non-phosphate glass formers.

11. The method of claim 1 wherein the phosphate glass is represented by the formula a(A′2O)x(P2O5)y1b(GfO)y2c(A″O)z

12. The method of claim 11 wherein A′ is lithium, Gf is boron, and A″ is magnesium.

13. The method of claim 11 wherein A′ is lithium, Gf is boron, and A″ is magnesium and barium.

14. The method of claim 11 wherein A′ is lithium, Gf is boron, and A″ is magnesium, barium and aluminum.

15. The method of claim 11 wherein A′ is lithium, Gf is boron, and A″ is magnesium, barium, aluminum and silicon.

16. The method of claim 1 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; and barium carbonate.

17. The method of claim 1 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; and boric acid.

18. The method of claim 1 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; and aluminum phosphate.

19. The method of claim 1 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; and silica.

20. The method of claim 1 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; silica; and mono-aluminum phosphate.

21. The method of claim 2 wherein the additional salt comprises a salt of an alkaline earth metal, a transition metal, a main group element, a multivalent non-metallic element, or a mixture of two or more thereof.

22. The method of claim 2 wherein the cation of the additional salt is derived from an alkaline earth metal, boron, iron, manganese, tin, zinc, or a mixture of two or more thereof.

23. The method of claim 2 wherein the aluminum salt comprises an aluminum halide, an aluminum nitrate, an aluminum phosphate, aluminum sulfate, aluminum oxide, aluminum hydroxide, or a mixture of two or more thereof.

24. The method of claim 2 wherein the metal to phosphate atomic ratio for the pretreating composition is in the range from about 0.26 to about 0.50.

25. A method of inhibiting oxidation of a porous carbon-carbon composite, comprising: applying a pretreating composition to the surface of the carbon-carbon composite, the pretreating composition comprising phosphoric acid and/or at least one acid phosphate salt, at least one aluminum salt, and optionally at least one additional metal salt, and drying the pretreating composition;applying an oxidation inhibiting composition to the surface of the carbon-carbon composite over the pretreating composition, the oxidation inhibiting composition comprising at least one phosphate glass; andheating the carbon-carbon composite at a sufficient temperature to adhere the phosphate glass to the carbon-carbon composite.

26. A method of inhibiting oxidation of a porous carbon-carbon composite, comprising: applying a pretreating composition to the surface of the carbon-carbon composite, the pretreating composition comprising phosphoric acid and/or at least one acid phosphate salt, mono-aluminum phosphate, and optionally at least one additional metal salt, the pretreating composition penetrating the pores of the carbon-carbon composite, and drying the pretreating composition;applying an oxidation inhibiting composition to the surface of the carbon-carbon composite over the pretreating composition, the oxidation inhibiting composition comprising at least one borophosphate glass, ammonium phosphate and water; andheating the carbon-carbon composite at a sufficient temperature to adhere the borophosphate glass to the carbon-carbon composite.

27. A composition comprising at least one phosphate glass and at least one carrier liquid.

28. The composition of claim 27 wherein the composition further comprises at least one ammonium phosphate.

29. The composition of claim 27 wherein the composition further comprises at least one ammonium phosphate, at least one metal phosphate, or a mixture thereof.

30. The composition of claim 27 wherein the composition further comprises at least one refractory compound.

31. The composition of claim 30 wherein the refractory compound comprises aluminum orthophosphate, boron phosphate, manganese dioxide, spinel, aluminum nitride, boron nitride, silicon carbide, boron carbide, silicon nitride, titanium boride, zirconium boride, or a mixture of two or more thereof.

32. The composition of claim 27 wherein the composition further comprises at least one wetting agent.

33. The composition of claim 27 wherein the phosphate glass comprises at least one borophosphate glass.

34. The composition of claim 27 wherein the phosphate glass is derived from phosphorus pentoxide or a precursor thereof, at least one glass modifier, at least one glass network modifier, and optionally at least one additional glass former.

35. The composition of claim 27 wherein the phosphate glass is represented by the formula a(A′2O)x(P2O5)y1b(GfO)y2c(A″O)z

36. The composition of claim 35 wherein A′ is lithium, Gf is boron, and A″ is magnesium.

37. The composition of claim 35 wherein A′ is lithium, Gf is boron, and A″ is magnesium and barium.

38. The composition of claim 35 wherein A′ is lithium, Gf is boron, and A″ is magnesium, barium and aluminum.

39. The composition of claim 35 wherein A′ is lithium, Gf is boron, and A″ is magnesium, barium, aluminum and silicon.

40. The composition of claim 26 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; and barium carbonate.

41. The composition of claim 27 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; and boric acid.

42. The composition of claim 27 wherein the phosphate glass is derived from ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; and silica.

43. The composition of claim 27 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; silica; and aluminum phosphate.

44. The composition of claim 27 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; and aluminum phosphate.

45. The composition of claim 27 wherein the carrier liquid comprises water, a non-aqueous polar liquid, or a mixture thereof.

46. The composition of claim 29 wherein the metal phosphate comprises magnesium phosphate, manganese phosphate, aluminum phosphate, zinc phosphate, or a mixture of two or more thereof.

47. The composition of claim 29 wherein the metal phosphate comprises aluminum orthophosphate, monoaluminum phosphate, or a mixture thereof.

48. The composition of claim 29 wherein the ammonium phosphate comprises ammonium dihydrogen phosphate, ammonium hydrogen phosphate, or a mixture thereof.

49. A composition comprising: from about 5 to about 95% by weight of at least one phosphate glass; from about 5 to about 95% by weight of at least one carrier liquid; up to about 40% by weight of at least one ammonium and/or metal phosphate; up to about 50% by weight of at least one refractory compound; and up to about 3% by weight of at least one wetting agent.

50. A treated carbon-carbon composite, comprising: a carbon-carbon composite; and at least one phosphate glass overlying at least one surface of the carbon-carbon composite.

51. The treated carbon-carbon composite of claim 50 wherein the phosphate glass overlies deposits formed from a pretreating composition applied to the surface of the carbon-carbon composite, the pretreating composition comprising phosphoric acid and/or at least one acid phosphate salt, at least one aluminum salt, and optionally at least one additional metal salt, the pretreating composition penetrating at least some of the pores of the carbon-carbon composite.

52. The treated carbon-carbon composite of claim 50 wherein the phosphate glass overlies a barrier coating applied to the surface of the carbon-carbon composite.

53. The treated carbon-carbon composite of claim 50 wherein the phosphate glass is derived from phosphorus pentoxide or a precursor thereof, one or more glass modifiers, one or more glass network modifiers, and optionally one or more additional glass formers.

54. The treated carbon-carbon composite of claim 50 wherein the phosphate glass is represented by the formula a(A′2O)x(P2O5)y1b(GfO)y2c(A″O)z

55. The treated carbon-carbon composite of claim 54 wherein A′ is lithium, Gf is boron, and A″ is magnesium.

56. The treated carbon-carbon composite of claim 54 wherein A′ is lithium, Gf is boron, and A″ is magnesium and barium.

57. The treated carbon-carbon composite of claim 54 wherein A′ is lithium, Gf is boron, and A″ is magnesium, barium and aluminum.

58. The treated carbon-carbon composite of claim 54 wherein A′ is lithium, Gf is boron, and A″ is magnesium, barium, aluminum and silicon.

59. The treated carbon-carbon composite of claim 50 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; and barium carbonate.

60. The treated carbon-carbon composite of claim 50 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; and boric acid.

61. The treated carbon-carbon composite of claim 50 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; and aluminum phosphate.

62. The treated carbon-carbon composite of claim 50 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; and silica.

63. The treated carbon-carbon composite of claim 50 wherein the phosphate glass is derived from: ammonium dihydrogen phosphate and/or diammonium hydrogen phosphate; lithium carbonate; magnesium carbonate; barium carbonate; boric acid; silica; and aluminum phosphate.

64. The treated carbon-carbon composite of claim 51 wherein the additional salt comprises a salt of an alkaline earth metal, a transition metal, a main group element, a multivalent non-metallic element, or a mixture of two or more thereof.

65. The treated carbon-carbon composite of claim 51 wherein the cation of the additional salt is derived from an alkaline earth metal, boron, iron, manganese, tin, zinc, or a mixture of two or more thereof.

66. The treated carbon-carbon composite of claim 51 wherein the aluminum salt comprises aluminum halide, aluminum nitrate, aluminum phosphate, aluminum sulfate, aluminum oxide, aluminum hydroxide, or a mixture of two or more thereof.

67. The treated carbon-carbon composite of claim 51 wherein the metal to phosphate atomic ratio for the pretreating composition is in the range from about 0.26 to about 0.50.

68. The treated carbon-carbon composite of claim 50 wherein the phosphate glass is combined with at least one refractory compound.

69. The treated carbon-carbon composite of claim 68 wherein the refractory compound comprises aluminum orthophosphate, boron phosphate, manganese dioxide, spinel, aluminum nitride, boron nitride, silicon carbide, boron carbide, silicon nitride, titanium boride, zirconium boride, or a mixture of two or more thereof.

70. The method of claim 1 wherein prior to step (A), a particulate material is applied to the surface of the carbon-carbon composite.

71. The method of claim 70 wherein the particulate material comprises a glass, an aluminate, an aluminum phosphate, a silicate, a phosphate, a graphite, a carbon black, a metal oxide, a metal carbide, a boride, or a mixture of two or more thereof, the mean particle size of the particulate material being in the range up to about 300 microns.

72. The method of claim 2 wherein prior to applying the pretreating composition to the surface of the carbon-carbon composite, a particulate material is applied to the surface of the carbon-carbon composite.

73. The method of claim 72 wherein the particulate material comprises a glass, an aluminate, an aluminum phosphate, a silicate, a phosphate, a graphite, a carbon black, a metal oxide, a metal carbide, a boride, or a mixture of two or more thereof, the mean particle size of the particulate material being in the range up to about 300 microns.

74. The method of claim 2 wherein the pretreating composition further comprises particulate material.

75. The method of claim 74 wherein the particulate material comprises a glass, an aluminate, an aluminum phosphate, a silicate, a phosphate, a graphite, a carbon black, a metal oxide, a metal carbide, a boride, or a mixture of two or more thereof, the mean particle size of the particulate material being in the range up to about 300 microns.

76. The treated carbon-carbon composite of claim 50 wherein a particulate material is adhered to the carbon-carbon composite and the phosphate glass overlies the particulate material.

77. The composite of claim 76 wherein the particulate material comprises a glass, an aluminate, an aluminum phosphate, a silicate, a phosphate, a graphite, a carbon black, a metal oxide, a metal carbide, a boride, or a mixture of two or more thereof, the mean particle size of the particulate material being in the range up to about 300 microns.

78. The treated carbon-carbon composite of claim 51 wherein a particulate material is adhered to the carbon-carbon composite and the deposits formed from the pretreating composition overlie the particulate material.

79. The composite of claim 78 wherein the particulate material comprises a glass, an aluminate, an aluminum phosphate, a silicate, a phosphate, a graphite, a carbon black, a metal oxide, a metal carbide, a boride, or a mixture of two or more thereof, the mean particle size of the particulate material being in the range up to about 300 microns.

80. A composition, comprising: phosphoric acid and/or at least one acid phosphate salt; at least one aluminum salt; optionally at least one additional salt; and at least one particulate material.

81. The composition of claim 80 wherein the particulate material comprises a glass, an aluminate, an aluminum phosphate, a silicate, a phosphate, a graphite, a carbon black, a metal oxide, a metal carbide, a boride, or a mixture of two or more thereof, the mean particle size of the particulate material being in the range up to about 300 microns.

82. The method of claim 70 wherein the particulate material comprises alumina particulates, the alumina particulates having a mean particle size in the range from about 2 nanometers to about 300 microns.

83. The method of claim 72, wherein the particulate material comprises alumina particulates, the alumina particulates having a mean particle size in the range from about 2 nanometers to about 300 microns.

84. The method of claim 74 wherein the particulate material comprises alumina particulates, the alumina particulates having a mean particle size in the range from about 2 nanometers to about 300 microns.

85. The composite of claim 76 wherein the particulate material comprises alumina particulates, the alumina particulates having a mean particle size in the range from about 2 nanometers to about 300 microns.

86. The composite of claim 78 wherein the particulate material comprises alumina particulates, the alumina particulates having a mean particle size in the range from about 2 nanometers to about 300 microns.

87. The composition of claim 80 wherein the particulate material comprises alumina particulates, the alumina particulates having a mean particle size in the range from about 2 nanometers to about 300 microns.