Lubricant composition for automatic transmissions

Patent metadata

Field	Value
Publication number	US-9469825-B2
Application number	US-201514656008-A
Country	US
Kind code	B2
Filing date	Mar 12, 2015
Priority date	Mar 12, 2015
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A transmission lubricant composition, a method of lubricating a machine part, and a transmission are provided that utilize select boronated and phosphorylated N-substituted polyisobutylene succinimide dispersants combined with metal containing detergents to achieve high friction durability and low wear rates for automatic transmissions.

First claim

What is claimed is:

1. A transmission lubricant composition comprising:
a major amount of a lubricating oil;
4.5 to 23 weight percent of a boronated and phosphorylated N-substituted polyisobutylene succinimide dispersant having a number average molecular weight of the polyisobutylene substituent greater than 1300 to 2300 as determined by gel permeation chromatography using polystyrene as the reference and a viscosity of the polyisobutylene at 100° C. of 2100 to 2700 cSt, a ratio of boron to phosphorus of 0.21 to 0.46, and a ratio of boron to nitrogen of 0.09 to 0.19, and an amount of boron to provide 58 to 371 ppm boron to the transmission lubricant composition; and
a metal containing detergent providing metal at greater than 0 ppm and up to 281 ppm to the transmission lubricant composition and delivering a soap content of 0.02 to 0.15 weight percent to the transmission lubricant composition.

2. The composition of claim 1 , wherein the transmission lubricant composition has a Brookfield viscosity at −40° C. of not more than 15,000 cP.

3. The composition of claim 1 , wherein the major amount of a lubricating oil is selected from the group consisting of a Group II base oil, a Group III base oil and/or a Group IV base oil as well as mixtures thereof.

4. The composition of claim 1 , wherein the transmission lubricant composition includes 4.5 to 7.7 weight percent of the boronated and phosphorylated N-substituted polyisobutylene succinimide dispersant.

5. The composition of claim 1 , wherein the metal containing detergent is a neutral to overbased sulfonate, phenate, or carboxylate with an alkali metal or alkaline earth metal salt.

6. The composition of claim 5 , wherein the metal containing detergent is a linear or branched sulfonate.

7. The composition of claim 1 , further comprising 0.08 to 1 weight percent of the metal containing detergent.

8. The composition of claim 1 , wherein the metal containing detergent is not boronated.

9. The composition of claim 1 , further comprising at least one component selected from the group consisting of a friction modifier, an air expulsion additive, an antioxidant, a corrosion inhibitor, a foam inhibitor, a seal-swell agent, a viscosity index improver, anti-rust agent, an extreme pressure additive, and mixtures thereof.

10. A method of lubricating a machine part comprising supplying thereto a lubricant composition, the method comprising:
lubricating a machine part with a lubricant composition, the lubricant composition including a mixture of
a major amount of a lubricating oil;
4.5 to 23 weight percent of a boronated and phosphorylated N-substituted polyisobutylene succinimide dispersant having a number average molecular weight of the polyisobutylene substituent greater than 1300 to 2300 as determined by gel permeation chromatography using polystyrene as the reference and a viscosity of the polyisobutylene at 100° C. of 2100 to 2700 cST, a ratio of boron to phosphorus of 0.21 to 0.46, and a ratio of boron to nitrogen of 0.09 to 0.19, and an amount of boron to provide 58 to 371 ppm boron to the lubricant composition; and
a metal containing detergent providing metal at greater than 0 ppm and up to 281 ppm to the lubricant composition and delivering a soap content of 0.02 to 0.15 weight percent to the lubricant composition.

11. The method of claim 10 , wherein the lubricant composition has a Brookfield viscosity at −40° C. of not more than 15,000 cP.

12. The method of claim 10 , wherein the major amount of a lubricating oil is selected from the group consisting of a Group II base oil, a Group III base oil and/or a Group IV base oil as well as mixtures thereof.

13. The method of claim 10 , wherein the lubricant composition includes 4.5 to 7.7 weight percent of the boronated and phosphorylated N-substituted polyisobutylene succinimide dispersant.

14. The method of claim 10 , wherein the metal containing detergent is a neutral to overbased sulfonate, phenate, or carboxylate with an alkali metal or alkaline earth metal salt.

15. The method of claim 14 , wherein the metal containing detergent is a linear or branched sulfonate.

16. The method of claim 10 , further comprising 0.08 to 1 weight percent of the metal containing detergent.

17. The method of claim 10 , wherein the metal containing detergent is not boronated.

18. The method of claim 10 , wherein the lubricant composition further includes at least one component selected from the group consisting of a friction modifier, an air expulsion additive, an antioxidant, a corrosion inhibitor, a foam inhibitor, a seal-swell agent, a viscosity index improver, anti-rust agent, an extreme pressure additive, and mixtures thereof.

Assignees

• Afton Chemical Corp

Inventors

• Tang Tom Hong-Zhi

Classifications

• C10M2207/028

  Overbased salts thereof · CPC title

• C10M2203/1025

  used as base material · CPC title

• C10N2020/069

  Linear chain compounds · CPC title

• C10N2030/06

  Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure · CPC title

• C10M2219/044

  Sulfonic acids, Derivatives thereof, e.g. neutral salts · CPC title