SEAL SWELL ADDITIVE

• US 20140336092A1
• Filed: 01/16/2013
• Published: 11/13/2014
• Est. Priority Date: 01/17/2012
• Status: Active Grant

• Current Assignee: Croda, Inc. (Croda International Plc (Technology Investment Group))
• Original Assignee: Croda, Inc. (Croda International Plc (Technology Investment Group))
• Inventors: Chen, Xin, Donaghy, Christopher, Kurchan, Alexei Nikolaevich
• Granted Patent: US 9,862,908 B2
• Time in Patent Office: Days
• US Class Current: 508/308
• CPC Class Codes: C10M 129/74 of polyhydroxy compounds
• CPC Class Codes: C10M 129/76 containing free hydroxy or carboxyl groups
• CPC Class Codes: C10M 2207/283 of polyhydroxy compounds
• CPC Class Codes: C10M 2207/289 containing free hydroxy groups
• CPC Class Codes: C10N 2030/02 Pour-point; Viscosity index
• CPC Class Codes: C10N 2030/36 Seal compatibility, e.g. with rubber
• CPC Class Codes: C10N 2040/04 Oil-bath; Gear-boxes; Automatic transmissions; Traction drives
• CPC Class Codes: C10N 2040/042 for automatic transmissions
• CPC Class Codes: C10N 2040/044 for manual transmissions
• CPC Class Codes: C10N 2040/08 Hydraulic fluids, e.g. brake-fluids
• CPC Class Codes: C10N 2040/25 Internal-combustion engines

Abstract

A seal swell agent for a lubricating fluid is described. The invention relates to a seal swell agent for use in lubricating oils, such as engine oils, turbine oils, automatic and manual transmission, or gear, fluids, drivetrain and gear oils and hydraulic fluids. The seal swell agent comprises a diester of sorbitol or a derivative thereof and at least one carboxylic acid. The invention extends to the use of a diester of sorbitol or a derivative thereof and at least one carboxylic acid as a seal swell agent, and a method of maintaining seal integrity.

Claims

1. A seal swell agent for a lubricating fluid comprising a diester of sorbitol or a derivative thereof and at least one carboxylic acid.

3. The seal swell agent of claim 1, wherein the sorbitol or derivative thereof comprises a derivative of sorbitol.

4. The seal swell agent of claim 1, wherein the derivative of sorbitol comprises a cyclic compound.

5. The seal swell agent of claim 1, wherein the sorbitol or derivative thereof is an isosorbide.

6. The seal swell agent of claim 1, wherein the carboxylic acid is a monocarboxylic acid.

7. The seal swell agent of claim 1, wherein the carboxylic acid is a C₄ to C₂₂ carboxylic acid.

8. The seal swell agent of claim 1, wherein the seal swell agent exhibits good stability at both low temperatures and high temperatures.

9. The seal swell agent of claim 1, wherein the seal swell agent has a kinematic viscosity of at least 0.1 cSt, and up to 100 cSt.

10. The seal swell agent of claim 1, wherein the seal swell agent is anhydrous.

11. The seal swell agent of claim 1, wherein the seal swell agent is oil-soluble.

2. (canceled)

12. A lubricating fluid comprising a base fluid and a seal swell additive, wherein the seal swell additive comprises a diester of sorbitol or a derivative thereof and at least one carboxylic acid.

14. The lubricating fluid of claim 12, wherein the sorbitol or derivative thereof comprises a derivative of sorbitol.

15. The lubricating fluid of claim 12, wherein the derivative of sorbitol comprises a cyclic compound.

16. The lubricating fluid of claim 12, wherein the sorbitol or derivative thereof is an isosorbide.

17. The lubricating fluid of claim 12, wherein the carboxylic acid is a monocarboxylic acid.

18. The lubricating fluid of claim 12, wherein the carboxylic acid is a C₄ to C₂₂ carboxylic acid.

19. The lubricating fluid of claim 12, wherein the seal swell agent exhibits good stability at both low temperatures and high temperatures.

20. The lubricating fluid of claim 12, wherein the seal swell agent has a kinematic viscosity of at least 0.1 cSt, and up to 100 cSt.

21. The lubricating fluid of claim 12, wherein the seal swell agent is anhydrous.

22. The lubricating fluid of claim 12, wherein the seal swell agent is oil-soluble.

13. A method of maintaining the seal integrity of natural and/or synthetic rubber seals in a lubricated system, the method comprising adding a seal swell agent to a lubricating fluid present in the lubricating system, the seal swell agent comprising a diester of sorbitol or a derivative thereof and at least one carboxylic acid.