Automatic transmission fluids with improved anti-shudder properties

• US 20020151441A1
• Filed: 02/14/2001
• Published: 10/17/2002
• Est. Priority Date: 02/14/2001
• Status: Abandoned Application

• Current Assignee: Nubar Ozbalik, Ramnath N. Iyer, Sanjay Srinivasan
• Original Assignee: Nubar Ozbalik, Ramnath N. Iyer, Sanjay Srinivasan
• Inventors: Ozbalik, Nubar, Srinivasan, Sanjay, Iyer, Ramnath N.
• Application Number:
  US09/783,065
• Publication Number:
  US 20020151441A1
• Time in Patent Office: Days
• US Class Current: 508/188
• CPC Class Codes: C10M 163/00 Lubricating compositions characterised by the additive being a mixture of a compound of unknown or incompletely defined constitution and a non-macromolecular compound, each of these compounds being essential
• CPC Class Codes: C10M 167/00 Lubricating compositions characterised by the additive being a mixture of a macromolecular compound, a non-macromolecular compound and a compound of unknown or incompletely defined constitution, each of these compounds being essential
• CPC Class Codes: C10M 169/045 the additives being a mixture of compounds of unknown or incompletely defined constitution and non-macromolecular compounds
• CPC Class Codes: C10M 2207/026 with tertiary alkyl groups
• CPC Class Codes: C10M 2207/028 Overbased salts thereof
• CPC Class Codes: C10M 2215/04 having amino groups bound to acyclic or cycloaliphatic carbon atoms
• CPC Class Codes: C10M 2215/042 containing hydroxy groups; Alkoxylated derivatives thereof
• CPC Class Codes: C10M 2215/064 Di- and triaryl amines
• CPC Class Codes: C10M 2215/082 containing hydroxyl groups; Alkoxylated derivatives
• CPC Class Codes: C10M 2215/224 Imidazoles
• CPC Class Codes: C10M 2215/28 Amides; Imides
• CPC Class Codes: C10M 2219/046 Overbasedsulfonic acid salts
• CPC Class Codes: C10M 2223/049 Phosphite
• CPC Class Codes: C10N 2010/04 Groups 2 or 12
• CPC Class Codes: C10N 2030/06 Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2040/042 for automatic transmissions
• CPC Class Codes: C10N 2060/12 by phosphorus or a compound containing phosphorus, e.g. PxSy
• CPC Class Codes: C10N 2060/14 by boron or a compound containing boron

Abstract

Automatic transmission fluids are described which contain at least 0.2 wt % of a metal-containing detergent, a dispersant, and a mixture of friction modifiers. The transmission fluids according to the present invention exhibit excellent initial anti shudder properties, excellent anti-shudder durability, and excellent friction durability.

Claims

1. An automatic transmission fluid, comprising:

(1) a major amount of a base oil, and

(2) a minor amount of an additive comprising

(A) at least about 0.10 weight % of a metal-containing detergent,

(B) a dispersant, and

(C) a mixture of at least two different friction modifiers.

2. An automatic transmission fluid as claimed in claim 1, wherein component (A) is a calcium containing detergent.

3. An automatic transmission fluid as claimed in claim 2, wherein component (A) is a calcium phenate, calcium sulfonate, or a mixture thereof.

4. An automatic transmission fluid as claimed in claim 1, wherein component (A) is overbased.

5. An automatic transmission fluid as claimed in claim 1, wherein component (A) is present in an amount of from 0.25 to abou t 1.5 wt %.

6. An automatic transmission fluid as claimed in claim 1, wherein component (A) is present in an amount of from about 0.75 wt % to about 1.00 wt %.

7. An automatic transmission fluid as claimed in claim 1, wherein component (B) is a succinimide dispersant.

8. An automatic transmission fluid as claimed in claim 7, wherein the succinimide is boronated, phosphorylated, or boronated and phosphorylated.

9. An automatic transmission fluid as claimed in claim 1, wherein the dispersant has a total nitrogen to phosphorus mass ratio of between about 3:

1 and about 10;

1.

10. An automatic transmission fluid as claimed in claim 1, where in the mixture of friction modifiers comprises a mixture of an ethoxylated amine and a fatty polyamine.

11. An automatic transmission fluid as claimed in claim 1, wherein component C is selected from the group consisting of ethoxylated fatty amines, aliphatic fatty alkanol amides, aliphatic primary amines, aliphatic secondary amines, and aliphatic fatty imidazolines.

12. An automatic transmission fluid as claimed in claim 1, wherein component C is selected from the group consisting of glycerol esters, aliphatic carboxylic ester amides, aliphatic carboxylic acids, aliphatic phosphonates, aliphatic phosphates, aliphatic thiophosphonates, and aliphatic thiophosphates.

13. An automatic transmission fluid as claimed in claim 1, further comprising at least one viscosity index improver, antioxidant, anti rust, or anti foam agent.

14. An automatic transmission fluid as claimed in claim 1, further comprising an additional phosphorus source.

15. An automatic transmission fluid as claimed in claim 12, wherein the phosphorus source is dibutyl hydrogen phosphate.

16. An automatic transmission fluid as claimed in claim 1, further comprising a shear stable viscosity index improver.

18. An automatic transmission fluid as claimed in claim 16, wherein the metal containing detergent is an overbased calcium sulfonate.

19. An automatic transmission fluid as claimed in claim 17, wherein the dispersant has a total nitrogen to phosphorus mass ratio of between about 3:

1 and about 10;

1.

20. The automatic transmission fluid as claimed in claim 17, wherein the friction modifier comprises a mixture of ethoxylated amine and fatty polyamine.

21. The automatic transmission fluid of claim 15 further comprising at least one additive selected from the group consisting of extreme pressure/antiwear agents, seal swell agents, foam inhibitors, rust inhibitors, viscosity index improvers, lubricity agents, and dyes.

22. The automatic transmission fluid of claim 15, wherein the fluid has a friction durability of at least 200 hours on the ECCC friction durability test as measured on the SAE #2 low speed rig.

17. An automatic transmission fluid composition having good initial anti-shudder performance and anti-shudder durability, comprising:

(1) a major amount of a base oil and

(2) a minor amount of an additive composition comprising;

(A) at least about 0.25 wt % of a metal-containing detergent,

(B) a dispersant, and

(C) a mixture of at least two amine-based friction modifiers.

23. A method of improving friction durability and anti-shudder performance of an automatic transmission said method comprising adding to, and operating in, said automatic transmission an automatic transmission fluid as set forth in claim 17.