Synergistic rust inhibitor combination for lubricating grease

Patent metadata

Field	Value
Publication number	US-10774285-B2
Application number	US-201515537914-A
Country	US
Kind code	B2
Filing date	Dec 21, 2015
Priority date	Dec 29, 2014
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

The disclosed technology relates to an additive composition and lubricating grease composition containing a synergistic combination of ingredients for inhibiting rust, particularly rust on mechanical devices subject to contact with salt water.

First claim

What is claimed is:

1. A lubricating grease composition comprising 1) a major amount of an oil of lubricating viscosity, 2) a grease thickener, 3) about 0.5 to about 10 wt. % of at least one salt of the phosphate hydrocarbon ester, wherein the salt of a phosphate hydrocarbon ester comprises a monoalkyl phosphate, dialkyl phosphate, or mixture thereof, and 4) about 0.5 to about 5 wt. % of at least one N-hydrocarbyl substituted imidazoline, wherein the N-hydrocarbyl substituted imidazoline is of formula:

wherein
the dashed line indicates resonance,
R 7 is a hydrocarbyl group containing from 2 to 18 carbon atoms and at least one heteroatom,
R 8 is hydrogen or a hydrocarbyl group containing from 1 to 40 carbon atoms, and
R 9 and R 10 are independently hydrogen or a hydrocarbyl group containing from 1 to 4 carbon atoms
wherein the ratio of the at least one salt of a phosphate hydrocarbon ester of 1) to the at least one imidazoline of 2) is from about 1:5 to about 5:1.

2. The lubricating grease of claim 1 , wherein the salt of a phosphate hydrocarbon ester is a monoalkyl phosphate, and the monoalkyl group comprises a C 4 to C 40 alkyl group.

3. The lubricating grease of claim 1 , wherein the salt of the phosphate hydrocarbon ester is a dialkyl phosphate, and the alkyl groups each comprise, individually, a C 4 to C40 alkyl group.

4. The lubricating grease of claim 1 , wherein the salt of a phosphate hydrocarbon ester is chosen from an amine salt, an alkali metal salt, an alkaline earth metal salt.

5. The lubricating grease of claim 1 , wherein the at least one salt of a phosphate hydrocarbon ester is an amine the salt of a phosphate hydrocarbon ester of formula:

wherein:
R 1 and R 2 are independently hydrogen or a hydrocarbon containing from 4 to 40 carbon atoms, with the proviso that at least one of R 1 or R 2 is a hydrocarbon group; and
R 3 , R 4 , R 5 and R 6 are independently hydrogen or a hydrocarbyl group containing from 4 to 40 carbon atoms, with the proviso that at least one of R 3 , R 4 , R 5 and R 6 is a hydrocarbyl group.

6. The lubricating grease of claim 1 , wherein the R 7 N-hydrocarbyl substituent in the at least one N-hydrocarbyl substituted imidazoline comprises a primary, secondary or tertiary alcohol.

7. The lubricating grease of claim 1 , wherein the at least one heteroatom of R 7 comprises at least one of O, N, S, a halogen, or a combination thereof.

8. The lubricating grease composition of claim 1 , further comprising 5) other performance additives.

9. The lubricating grease composition of claim 1 , wherein the grease thickener is lithium based.

10. A method of operating a mechanical device comprising A) supplying to the mechanical device a lubricating grease composition comprising 1) a major amount of an oil of lubricating viscosity, 2) about 1.5 to about 10 wt. % of at least one salt of a phosphate hydrocarbon ester, wherein the salt of a phosphate hydrocarbon ester comprises a monoalkyl phosphate, dialkyl phosphate, or mixture thereof, and 3) about 0.5 to about 5 wt % of at least one N-hydrocarbyl substituted imidazoline, and B) operating the mechanical device in the presence of water, wherein the N-hydrocarbyl substituted imidazoline is of formula:

wherein
the dashed line indicates resonance,
R 7 is a hydrocarbyl group containing from 2 to 18 carbon atoms and at least one heteroatom,
R 8 is hydrogen or a hydrocarbyl group containing from 1 to 40 carbon atoms, and
R 9 and R 10 are independently hydrogen or a hydrocarbyl group containing from 1 to 4 carbon atoms
wherein the ratio of the at least one salt of a phosphate hydrocarbon ester of 1) to the at least one imidazoline of 2) is from about 1:5 to about 5:1.

Assignees

• Lubrizol Corp

Inventors

• Capitosti Scott

Classifications

• C10N2050/10

  semi-solid; greasy · CPC title

• C10N2010/02

  Groups 1 or 11 · CPC title

• C10M113/00

  Lubricating compositions characterised by the thickening agent being an inorganic material · CPC title

• C10M2207/1256

  used as thickening agent · CPC title

• C10M2223/04

  Phosphate esters · CPC title