Graphite foam material and method of making same

• US 20010006263A1
• Filed: 02/21/2001
• Published: 07/05/2001
• Est. Priority Date: 01/25/1996
• Status: Abandoned Application

• Current Assignee: Tommie P. Hayward
• Original Assignee: Tommie P. Hayward
• Inventors: Hayward, Tommie P.
• Application Number:
  US09/790,822
• Publication Number:
  US 20010006263A1
• Time in Patent Office: Days
• US Class Current: 264/29.1
• CPC Class Codes: B29C 43/003 characterised by the choice of material
• CPC Class Codes: B29C 43/006 Pressing and sintering powders, granules or fibres
• CPC Class Codes: B29K 2303/06 Metal powders, metal carbides or the like
• CPC Class Codes: C04B 14/022 Carbon
• CPC Class Codes: C04B 14/024 Graphite
• CPC Class Codes: C04B 20/002 Hollow or porous granular materials
• CPC Class Codes: C04B 26/02 Macromolecular compounds
• CPC Class Codes: C04B 35/536 based on expanded graphite or complexed graphite
• CPC Class Codes: C04B 38/0022 obtained by a chemical conversion or reaction other than those relating to the setting or hardening of cement-like material or to the formation of a sol or a gel, e.g. by carbonising or pyrolysing preformed cellular materials based on polymers, organo-metallic or organo-silicon precursors
• CPC Class Codes: C04B 40/0071 making use of a rise in pressure
• CPC Class Codes: C04B 40/0082 making use of a rise in temperature, e.g. caused by an exothermic reaction
• CPC Class Codes: Y02P 20/582 Recycling of unreacted starting or intermediate materials

Abstract

Methods of making a graphite material are provided. A flexible graphite is ground into a powder. The graphite powder is mixed with a resin and the mixture is hot pressed. A second method of making a graphite material is provided where the graphite is ground into a powder; the graphite powder is soaked in a cryogenic liquid; the soaked graphite powder is then expanded; the expanded soaked graphite powder is mixed with a graphite powder; and the graphite powder mixed with a resin are hot pressed. According to a third method, the flexible graphite is ground into a powder; the graphite powder is soaked into a cryogenic liquid, the soaked graphite powder is expanded; and the expanded soaked graphic powder is ground into a fine powder. The resulting graphite powder is mixed with a resin. The graphite powder mixed with the resin is hot pressed. According to a fourth method, graphite flakes are soaked into an acid; the soaked graphite flakes are expanded; and the expanded soaked graphite flakes are precompacted. The precompacted soaked graphite flakes are ground into a powder. The ground precompacted expanded soaked graphite powder is then mixed with a resin. The graphite powder with the resin is hot pressed.

Claims

1. A method of making a graphite material comprising the steps of:

a) grinding flexible graphite into a powder having a particle size in a range of 25 to 80 mesh;

b) mixing the graphite powder in an amount ranging between approximately 10% - 90% by weight, with a resin, in an amount ranging between approximately 10% - 90% by weight; and

c) hot pressing said graphite powder mixed with said resin.

2. The method of

claim 1

wherein before hot pressing, said graphite powder mixed with said resin is introduced into a first mold.

3. The method of

claim 2

, said hot pressing is performed at a pressure that is less than 1 pounds per square inch (psi) and at a temperature of approximately 230°

Fahrenheit.

4. The method of

claim 3

wherein hot pressing further including,

removing from said first mold said graphite powder mixed with the resin,

placing said graphite powder mixed with the resin into a second mold, and

hot-pressing said graphite powder mixed with the resin at approximately 2000 pound per square inch (psi) and approximately 350°

F. for approximately 30 minutes.

5. The method of

claim 1

wherein said graphite material has a density of approximately 1.5 grams/centimeter cube (g/cc).

6. The method of

claim 1

wherein said resin includes phenolic resin.

7. The method of

claim 1

wherein said flexible graphite includes recycled graphite foil.

8. The method of

claim 3

wherein hot-pressing the graphite powder mixed with the resin at a pressure that is less than 1 pound per square inch (psi) and at a temperature of 230°

F. is performed for approximately 30 minutes.

9. A method of making a graphite material, the method comprising:

a) grinding flexible graphite into a powder having a particle size in a range of approximately 25 to 80 mesh;

b) soaking the graphite powder in a cryogenic liquid;

c) expanding the soaked graphite powder;

d) mixing the graphite powder in an amount ranging between approximately 10% - 90% by weight, with a resin, in an amount ranging between approximately 10% - 90% by weight; and

e) hot pressing said graphite powder mixed with said resin.

10. The method of

claim 9

wherein before hot pressing, said graphite powder mixed with said resin is introduced into a first mold.

11. The method of

claim 10

, said hot pressing is performed a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit.

12. The method of

claim 11

wherein said hot pressing further including,

removing from said first mold said expanded soaked graphite powder mixed with the resin,

introducing said expanded soaked graphite powder mixed with the resin into a second mold, and

hot-pressing said expanded soaked graphite powder mixed with the resin at approximately 2000 pounds per square inch (psi) approximately 350°

Fahrenheit for approximately 30 minutes.

13. The method of

claim 9

wherein said graphite material has a density of approximately 1.5 grams/centimeter cube (g/cc).

14. The method of

claim 9

wherein said resin includes phenolic resin.

15. The method of

claim 9

wherein said flexible graphite includes recycled graphite foil.

16. The method of

claim 11

wherein hot-pressing the graphite powder mixed with the resin at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit is performed for approximately 30 minutes.

17. The method of

claim 9

, wherein expanding the soaked graphite powder is performed by heating the expanded graphite powder to a temperature of approximately 650°

Fahrenheit (F.).

18. A method of making a graphite material, the method comprising:

a) grinding flexible graphite into a powder having a particle size in a range of approximately 25 to 80 mesh;

b) soaking the graphite powder in a cryogenic liquid;

c) expanding the soaked graphite powder;

d) grinding the expanded soaked graphite powder into a powder having a particle size in a range of approximately 48 to 100 mesh;

e) mixing the graphite powder in an amount ranging between approximately 10% - 90% by weight, with a resin, in an amount ranging between approximately 10% - 90% by weight; and

f) hot pressing said graphite powder mixed with said resin.

19. The method of

claim 18

wherein before hot pressing, said graphite powder mixed with said resin is introduced into a first mold.

20. The method of

claim 19

, said hot pressing is performed at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit.

21. The method of

claim 20

wherein said hot pressing further including,

removing from said first mold said graphite powder mixed with the resin,

introducing said graphite powder mixed with the resin into a second mold;

and

hot-pressing said graphite powder mixed with the resin at approximately 2000 pound per square inch (psi) and approximately 350°

Fahrenheit for approximately 30 minutes.

22. The method of

claim 18

wherein said graphite material has a density of approximately 1.5 grams/centimeter cube (g/cc).

23. The method of

claim 18

wherein said resin includes phenolic resin.

24. The method of

claim 18

wherein said flexible graphite includes recycled graphite foil.

25. The method of

claim 20

wherein hot-pressing the graphite powder mixed with the resin at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit is performed for approximately 30 minutes.

26. The method of

claim 18

, wherein expanding the soaked graphite powder is performed by heating the expanded graphite powder to a temperature of approximately 650°

Fahrenheit (F.).

27. A method of making a graphite material, the method comprising:

a) soaking graphite flakes into an acid;

b) expanding the soaked graphite flakes;

c) precompacting the expanded soaked graphite flakes;

d) grinding the precompacted expanded soaked graphite flakes into a powder having a particle size in a range of approximately 25 to 80 mesh;

e) mixing the ground, precompacted expanded soaked graphite powder in an amount ranging between approximately 10% - 90% by weight, with a resin, in an amount ranging between approximately 10% - 90% by weight; and

f) hot pressing said ground, precompacted expanded graphite powder mixed with said resin.

28. The method of

claim 27

, wherein before hot pressing, said graphite powder mixed with said resin is introduced into a first mold.

29. The method of

claim 28

, said hot pressing is performed at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit.

30. The method of

claim 29

wherein said hot pressing further including,

removing from said first mold said graphite powder mixed with the resin,

placing said expanded soaked graphite powder mixed with the resin into a second mold;

and

hot-pressing said graphite powder mixed with the resin at approximately 2000 pounds per square inch (psi) and approximately 350°

Fahrenheit for approximately 30 minutes.

31. The method of

claim 27

wherein said graphite material has a density of approximately 1.5 grams/centimeter cube (g/cc).

32. The method of

claim 27

wherein said resin includes phenolic resin.

33. The method of

claim 29

wherein hot-pressing the graphite powder mixed with the resin at less than 1 pound per square inch (psi) and at approximately 250°

F. is performed for approximately 30 minutes.

34. The method of

claim 27

, said acid includes sulfuric acid.

35. The method of

claim 27

, said acid includes nitric acid.

36. The method of

claim 29

wherein hot-pressing the graphite powder mixed with the resin at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit is performed for approximately 30 minutes.

37. A graphite material made by a process comprising:

a) grinding flexible graphite into a powder having a particle size in a range of 25 to 80 mesh;

b) mixing the graphite powder in an amount ranging between approximately 10% - 90% by weight, with a resin, in an amount ranging between approximately 10% - 90% by weight; and

c) hot pressing said graphite powder mixed with said resin.

38. The graphite material of

claim 37

wherein before hot pressing, said graphite powder mixed with said resin is introduced into a first mold.

39. The graphite material of

claim 38

, said hot pressing is performed at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit.

40. The graphite material of

claim 39

wherein said hot pressing further including,

removing from said first mold said graphite powder mixed with the resin,

placing said graphite powder mixed with the resin into a second mold, and

hot-pressing said graphite powder mixed with the resin at approximately 2000 pounds per square inch (psi) and approximately 350°

Fahrenheit for approximately 30 minutes.

41. The graphite material of

claim 37

wherein said graphite material has a density of approximately 1.5 grams/centimeter cube (g/cc).

42. The graphite material of

claim 37

wherein said resin includes phenolic resin.

43. The graphite material of

claim 37

wherein said flexible graphite includes recycled graphite foil.

44. The graphite material of

claim 39

wherein hot-pressing the graphite powder mixed with the resin at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit is performed for approximately 30 minutes.

45. A graphite material made by a process comprising:

a) grinding flexible graphite into a powder having a particle size in a range of 25 to 80 mesh;

b) soaking the graphite powder in a cryogenic liquid;

c) expanding the soaked graphite powder;

d) mixing the expanded soaked graphite powder in an amount ranging between approximately 10% - 90% by weight, with a resin, in an amount ranging between approximately 10% - 90% by weight; and

e) hot pressing said expanded soaked graphite powder mixed with said resin.

46. The graphite material of

claim 45

wherein before hot pressing, said expanded soaked graphite powder mixed with said resin is introduced into a first mold.

47. The graphite material of

claim 46

, said hot pressing is performed at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit.

48. The graphite material of

claim 47

wherein said hot pressing further including,

removing from said first mold said expanded soaked graphite powder mixed with the resin,

placing said expanded soaked graphite powder mixed with the resin into a second mold, and

hot-pressing said expanded soaked graphite powder mixed with the resin at approximately 2000 pounds per square inch (psi), and approximately 350°

Fahrenheit, for approximately 30 minutes.

49. The graphite material of

claim 45

wherein said graphite material has a density of approximately 1.5 grams/centimeter cube (g/cc).

50. The graphite material of

claim 45

wherein said resin includes phenolic resin.

51. The graphite material of

claim 45

wherein said flexible graphite includes recycled graphite foil.

52. The graphite material of

claim 47

wherein hot-pressing the graphite powder mixed with the resin at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit is performed for approximately 30 minutes.

53. The graphite material of

claim 45

, wherein expanding the soaked graphite powder is performed by heating the soaked graphite powder to a temperature of approximately 650°

Fahrenheit (F.).

54. A graphite material made by a process comprising:

a) grinding flexible graphite into a powder having a particle size in a range of 25 to 80 mesh;

b) soaking the graphite powder in a cryogenic liquid;

c) expanding the soaked graphite powder;

d) grinding the expanded soaked graphite powder into a powder having a particle size in a range of approximately 48 to 100 mesh;

e) mixing the graphite powder in an amount ranging between approximately 10% - 90% by weight, with a resin, in an amount ranging between approximately 10% - 90% by weight; and

f) hot pressing said graphite powder mixed with said resin.

55. The graphite material of

claim 54

wherein before hot pressing, said graphite powder mixed with said resin is introduced into a first mold.

56. The graphite material of

claim 55

, said hot pressing is performed at less than 1 pound per square inch (psi) and at approximately 250°

F.

57. The graphite material of

claim 56

wherein hot-pressing the graphite powder mixed with the resin at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit is performed for approximately 30 minutes.

58. The graphite material of

claim 57

wherein said hot pressing further including,

removing from said first mold said graphite powder mixed with the resin,

placing said graphite powder mixed with the resin into a second mold, and

hot-pressing said graphite powder mixed with the resin at approximately 2000 pounds per square inch (psi) and approximately 350°

Fahrenheit for approximately 30 minutes.

59. The graphite material of

claim 54

, wherein expanding the soaked graphite powder is performed by heating the expanded graphite powder to a temperature of approximately 650°

Fahrenheit (F.).

60. A graphite material made by a process comprising:

a) soaking graphite flakes into an acid;

b) expanding the soaked graphite flakes;

c) precompacting the expanded soaked graphite flakes;

d) grinding the precompacted expanded soaked graphite into a powder having a particle size in an approximate range of 25 to 80 mesh;

e) mixing the expanded soaked graphite powder in an amount ranging between approximately 10% - 90% by weight, with a resin, in an amount ranging between approximately 10% - 90% by weight; and

f) hot pressing said graphite powder mixed with said resin.

61. The graphite material of

claim 60

wherein before hot pressing, said graphite powder mixed with said resin is introduced into a first mold.

62. The graphite material of

claim 61

, said hot pressing is performed at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit.

63. The graphite material of

claim 62

wherein said hot pressing further including,

removing from said first mold said graphite powder mixed with the resin,

placing said graphite powder mixed with the resin into a second mold, and

hot-pressing said graphite powder mixed with the resin at approximately 2000 pounds per square inch (psi) and approximately 350°

Fahrenheit for approximately 30 minutes.

64. The graphite material of

claim 62

wherein hot-pressing the graphite powder mixed with the resin at a pressure that is less than 1 pound per square inch (psi) and at a temperature of approximately 230°

Fahrenheit is performed for approximately 30 minutes.

65. The graphite material of

claim 60

wherein expanded soaked graphite flakes are precompacted to a density of approximately 0.1 g/cc.

66. A graphite material made by a process comprising:

a) grinding flexible graphite into a powder;

b) mixing the graphite powder with a thermoplastic material; and

c) injecting into a mold the graphite powder mixed with the thermoplastic material.

67. The graphite material of

claim 66

wherein said plastic material formed has a density of approximately 1.7 grams/centimeter cube.

68. The process of

claim 66

wherein said thermoplastic material is Poly Phelene Sulfide.

69. A bipolar plate made of the graphite material of

claim 67

.

70. A gasket made by the graphite material of

claim 67

.

71. A graphite material made by a process comprising:

a) grinding flexible graphite into a graphite powder;

b) soaking said graphite powder into a cryogenic liquid;

c) expanding the soaked braphite powder;

d) mixing the expanded graphite with a thermoset resin, and

e) heating the graphite resin mixture under pressure.

f) heat treating the product of step e.

72. The graphite material of

claim 71

wherein expanding the soaked graphite powder is performed by heating the soaked graphite material.

73. The graphite material of

claim 71

wherein said graphite of step a is flexible graphite foil.

74. The graphite material of

claim 71

wherein said graphite foil is recycled graphite foil.