Aluminum hydroxides as solid lubricants

• US 4,919,829 A
• Filed: 12/30/1988
• Issued: 04/24/1990
• Est. Priority Date: 12/30/1988
• Status: Expired due to Term

• Current Assignee: United States Secretary of Commerce
• Original Assignee: THE GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE
• Inventors: Hsu, Stephen M., Gates, Richard S.
• Primary Examiner(s): Howard, Jacqueline V.
• Application Number:
  US07/292,176
• Time in Patent Office: 480 Days
• Field of Search: 252/18, 252/25, 423/625
• US Class Current: 508/172
• CPC Class Codes: C10M 103/06 Metal compounds
• CPC Class Codes: C10M 125/10 Metal oxides, hydroxides, carbonates or bicarbonates
• CPC Class Codes: C10M 173/02 not containing mineral or fatty oils
• CPC Class Codes: C10M 2201/02 Water
• CPC Class Codes: C10M 2201/062 Oxides; Hydroxides; Carbonates or bicarbonates
• CPC Class Codes: C10N 2040/00 Specified use or application for which the lubricating composition is intended
• CPC Class Codes: C10N 2040/30 Refrigerators lubricants or compressors lubricants
• CPC Class Codes: C10N 2040/32 Wires, ropes or cables lubricants
• CPC Class Codes: C10N 2040/34 Lubricating-sealants
• CPC Class Codes: C10N 2040/36 Release agents or mold release agents
• CPC Class Codes: C10N 2040/38 Conveyors or chain belts
• CPC Class Codes: C10N 2040/40 Generators or electric motors in oil or gas winning field
• CPC Class Codes: C10N 2040/42 Flashing oils or marking oils
• CPC Class Codes: C10N 2040/44 Super vacuum or supercritical use
• CPC Class Codes: C10N 2040/50 Medical uses
• CPC Class Codes: C10N 2050/01 Emulsions, colloids, or micelles

Abstract

Aluminum hydroxides are used as solid lubricants for aluminum oxides, cercs and other materials having oxide surfaces. Aluminum oxide hydroxides and aluminum trihydroxides are preferred compositions for such lubricating purposes. In particular, the use of boehmite in an aqueous solution significantly reduces frictional coefficients between contacting surfaces.

Claims

1. A lubricant for lubricating aluminum oxide layers, aluminum containing materials, ceramics and other oxide materials consisting essentially of one member selected from the group consisting of aluminum oxide hydroxides and aluminum trihydroxides dispersed in water and present in a concentration of up to about two percent by weight.

2. A lubricant according to claim 1, wherein said aluminum trihydroxide is one member selected from the group consisting of gibbsite and bayerite.

3. A lubricant according to claim 1, wherein said aluminum oxide hydroxide is boehmite.

4. A lubricant according to claim 1, wherein said member has an average crystalline size of less than 10 micrometers.

5. A lubricant according to claim 3, wherein said boehmite has an average crystalline size of less than 10 micrometers.

6. A method of lubricating an interface between an oxide material and a contacting surface which in use moves relative to said oxide material comprising applying a layer of lubricant between said oxide material and said contacting surface;

wherein said lubricant comprises one member selected from the group consisting of aluminum oxide hydroxide and aluminum trihydroxide in a particulate form.

7. A method according to claim 6, wherein said lubricant comprises an aqueous dispersion of said member.

8. A method according to claim 6, wherein said aluminum oxide hydroxide is boehmite.

9. A method according to claim 6, wherein said aluminum trihydroxide is at least one member selected from the group consisting of gibbsite, bayerite and nordstrandite.

10. A method according to claim 7, wherein said aqueous solution dispersion is about 98 percent water.

11. A method according to claim 6, wherein said powdered member has a crystalline size of less than 10 micrometers.

12. A method according to claim 7, wherein said aqueous dispersion is about 2% boehmite.

13. A method of lubricating an interface between two contacting surfaces comprising applying a layer of lubricant between said two contacting surfaces which in use move relative to each other, wherein said lubricant comprises a layer lattice aluminum compound.

14. A method according to claim 13, wherein said compound is selected from the group consisting of an aluminum oxide hydroxide and an aluminum trihydroxide.

15. A method according to claim 13, wherein at least one said contacting surface comprises at least one member selected from the group consisting of aluminum, aluminum containing materials and ceramics.

16. A method according to claim 15, wherein said lattice layer aluminum compound is selected from the group consisting of aluminum oxide hydroxides and aluminum trihydroxides.

17. A method according to claim 16, wherein said aluminum oxide hydroxide is boehmite.

18. A method according to claim 16, wherein said aluminum oxide hydroxide is dispersed in water.

19. A method according to claim 16, wherein said aluminum oxide hydroxide is boehmite and is present in a concentration of about 2 percent.

20. A method according to claim 16, wherein said aluminum trihydroxide is dispersed in water and is present in a concentration of about 2 percent.

21. A method according to claim 19, wherein said boehmite is in a powdered form and has an average crystalline size of less than 10 micrometers.