Transmission fluid compositions for hybrid and electric vehicle applications

Patent metadata

Field	Value
Publication number	US-11905488-B2
Application number	US-202017072398-A
Country	US
Kind code	B2
Filing date	Oct 16, 2020
Priority date	Oct 16, 2020
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

A transmission fluid composition contains a major amount of a lubricating oil basestock, and a minor amount of an additive package comprising: (i) a mixture comprising two or more phosphites and/or phosphates; (ii) one or more thioester compounds; (iii) a detergent comprising calcium salicylate; and (iv) a poly(alkylene amine)-based ashless dispersant endcapped with metallocene-catalyzed PAO arms. Such a transmission fluid may be used for controlling/reducing wear in at least partially electrically-powered transmissions and/or for cooling/insulating electrical/electronic components of at least partially electrically-powered drivetrains.

First claim

What is claimed is:

1. A transmission fluid composition comprising:
a major amount of a lubricating oil basestock; and
a minor amount of an additive package comprising:
(i) from 0.05 to 0.5 wt% of a mixture comprising two or more compounds of structures (I):

wherein groups R 1 , R 2 and R 3 are independently alkyl groups having 1 to 18 carbon atoms or alkyl groups having 1 to 18 carbon atoms where the alkyl chain is interrupted by a thioether linkage, provided that, in the mixture (i), at least some of groups R 1 , R 2 and R 3 are alkyl groups having 1 to 18 carbon atoms in which the alkyl chain is interrupted by a thioether linkage;
(ii) from 0.07 to 0.4 wt% of a compound of structure (II) comprising:

wherein groups R 4 and R 7 are independently alkyl groups having 1 to 12 carbon atoms and R 5 is an alkyl linkage having 2 to 12 carbon atoms;
(iii) a detergent comprising calcium salicylate; and
(iv) a basic nitrogen-containing ashless dispersant comprising one or more compounds of structure (III):

wherein:
R 8 and R 9 are each independently a hydrocarbon group made by the metallocene-catalyzed polymerization of an α-olefin feedstock consisting essentially of 1-octene, 1-decene, 1-dodecene, or mixtures thereof;
each R 10 is independently hydrogen, an acetyl moiety, or a moiety formed by reaction between ethylene carbonate and >N—R 10 ; and
x is from 1 to 10 and is the same for all molecules of structure (III) or is an average of all molecules of structure (III) in a mixture of molecules of structure (III).

2. A transmission fluid composition according to claim 1 , wherein the compounds of component (i) and component (ii) are present in the composition in a mass ratio of from 2:1 to 1:2.

3. A transmission fluid composition according to claim 1 , wherein component (iii) is present in the composition in an amount from 0.05 to 0.7% by mass, based on the total mass of the composition.

4. A transmission fluid composition according to claim 1 , wherein component (iii) provides the composition with 45 to 450 parts per million by mass (ppm) of calcium, based on the total mass of the composition.

5. A transmission fluid composition according to claim 1 , wherein component (iii) comprises no intentionally added phenate detergent component and/or comprises no intentionally added sulfonate detergent component.

6. A transmission fluid composition according to claim 1 , wherein component (iv) is present in the composition in an amount from 0.75 to 5.0% by mass, based on the total mass of the composition.

7. A transmission fluid composition according to claim 1 , wherein, in structure (III):
each R 10 is independently hydrogen or an acetyl moiety; and x is from 3 to 10.

8. A transmission fluid composition according to claim 1 , wherein R 8 and R 9 moieties of the ashless dispersant of component (iv) each independently has a number average molecular weight (Mn) from 300 to 20000 Daltons, as determined by GPC with reference to linear polystyrene standards.

9. A transmission fluid composition according to claim 1 , further comprising an additional basic nitrogen-containing ashless dispersant of structure (IV):

wherein:
R 11 and R 12 are each independently a hydrocarbyl group having a number average molecular weight (Mn) from 500 to 5000 Daltons, as determined by GPC with reference to linear polystyrene standards;
each R 13 is independently hydrogen, an acetyl moiety, or a moiety formed by reaction between ethylene carbonate and >N—R 13 ; and
y is from 3 to 10 and is the same for all molecules of structure (IV) or is an average of all molecules of structure (IV) in a mixture of molecules of structure (IV).

10. A transmission fluid composition according to claim 9 , wherein:
R 11 and R 12 are each independently a polyisobutenyl moiety having a number average molecular weight (Mn) from 750 to 2500 Daltons, as determined by GPC with reference to linear polystyrene standards; and
each R 13 is independently hydrogen or an acetyl moiety.

11. A transmission fluid composition according to claim 1 , further comprising substantially no other basic nitrogen-containing ashless dispersants other than component (iv).

12. A transmission fluid composition according to claim 1 , wherein the composition comprises less than 100 parts per million by mass (ppm) of boron, based on the total mass of the composition.

13. A transmission fluid composition according to claim 1 , wherein the lubricating oil basestock comprises a Group III basestock, a Group IV basestock, or a combination thereof.

14. A transmission fluid composition according to claim 1 , further comprising a substituted thiadiazole, an aminic antioxidant, a phenolic antioxidant, a corrosion inhibitor, and a friction modifier having the following structure:

wherein each of R 18 and R 19 is independently:

such that x+y is from 8 to 15 and z is an integer from 1 to 5; and wherein each R 20 is independently hydrogen, an acetyl moiety, or a moiety formed by reaction between ethylene carbonate and >N—R 20 .

15. A transmission fluid composition according to claim 1 , wherein:
the lubricating oil basestock exhibits a kinematic viscosity at 100° C. (KV100), as measured according to ASTM D445, from 1.5 cSt to 8.1 cSt;
the composition exhibits a KV100, as measured according to ASTM D445, from 2 cSt to 6.5 cSt;
the composition exhibits an average volume resistivity at about 80° C. of at least 46.0 MΩ·m; and
the composition exhibits an average needle-bearing fatigue lifetime of at least 13.0 Megacycles.

16. A transmission fluid composition according to claim 1 , wherein the composition exhibits an average volume resistivity at about 80° C. of at least 47.0 MΩ·m and an average needle-bearing fatigue lifetime of at least 14.0 Megacycles.

17. A transmission fluid composition according to claim 1 , wherein the composition exhibits an average volume resistivity at about 80° C. of up to 95.0 MΩ·m and an average needle-bearing fatigue lifetime of up to 30.0 Megacycles.

18. A transmission fluid composition according to claim 1 , wherein the composition exhibits an average volume resistivity at about 80° C. of up to 72.0 MΩ·m and an average needle-bearing fatigue lifetime of up to 25.0 Megacycles.

19. A method of controlling or reducing wear in a transmission powered by a hybrid electric or fully electric motor and simultaneously cooling at least a portion of electrical or electronic components of a hybrid electric- or fully electric-powered drivetrain, the method comprising lubricating the transmission and contacting one or more electrical or electronic components of the drivetrain with a transmission fluid composition according to claim 1 .

20. A transmission fluid composition comprising:
a major amount of a lubricating oil basestock

Assignees

• Infineum Int Ltd

Inventors

• Cunningham Matthew
• Chiappelli Maria C
• Noles Jr Joe R
• Cogen Kerry L
• Gorda Keith R
• Kim Hahnsoo
• Watts Raymond F
• Kahsar Laura A

Classifications

• C10M169/04 Primary

  Mixtures of base-materials and additives · CPC title

• C10M129/72

  of polycarboxylic acids · CPC title

• C10M133/44

  Five-membered ring containing nitrogen and carbon only · CPC title

• C10M135/24

  containing hydroxy groups; Derivatives thereof · CPC title

• C10M137/04 Primary

  Phosphate esters · CPC title