Grease composition

Patent metadata

Field	Value
Publication number	US-11746303-B2
Application number	US-202017423252-A
Country	US
Kind code	B2
Filing date	Jan 31, 2020
Priority date	Jan 31, 2019
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

The present invention relates to a grease composition which can impart excellent durability to a bearing used under a high-speed rotation condition with a DN value of 100,000 or more, wherein the grease composition contains a base oil (A) and a urea-based thickener (B), and particles containing the urea-based thickener (B) in the grease composition satisfy requirement (I) that the particles have an arithmetic mean particle diameter of 2.0 μm or less on an area basis when measured by a laser diffraction scattering method. The grease composition is used for a bearing used under a high-speed rotation condition with a DN value of 100,000 or more.

First claim

The invention claimed is:

1. A lubricating method, comprising:
lubricating a bearing used under a high-speed rotation condition with a DN value of 100,000 or more by a grease composition that comprises:
a base oil (A), and
a urea-based thickener (B),
wherein particles containing the urea-based thickener (B) in the grease composition have an arithmetic mean particle diameter of 2.0 μm or less on an area basis when measured by a laser diffraction scattering method.

2. The lubricating method according to claim 1 , wherein:
the urea-based thickener (B) comprises a diurea compound of formula (b1):
R 1 —NHCONH—R 3 —NHCONH—R 2   (b1)

wherein R 1 and R 2 each independently represent a monovalent hydrocarbon group having 6 to 24 carbon atoms, R 1 and R 2 are different from each other, at least one of R 1 and R 2 represents a monovalent hydrocarbon group having 10 to 24 carbon atoms, and R 3 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

3. The lubricating method according to claim 1 , wherein the particles containing the urea-based thickener (B) have a specific surface area of 20,000 cm 2 /cm 3 or more, as measured by a laser diffraction scattering method.

4. The lubricating method according to claim 1 , wherein the base oil (A) is one or more selected from the group consisting of a mineral oil, a hydrocarbon-based oil, an aromatic-based oil, an ester-based oil, and an ether-based oil.

5. The lubricating method according to claim 1 , wherein the base oil (A) has a kinematic viscosity at 40° C. of 10 to 300 mm 2 /s.

6. The lubricating method according to claim 1 , wherein the urea-based thickener (B) has an amount of from 1 to 40% by mass based on a whole amount of the grease composition.

7. The lubricating method according to claim 1 , wherein the grease composition further comprises at least one additive (C) selected from the group consisting of an antioxidant, a rust inhibitor, a dispersant, an extreme pressure agent, and a metal deactivator.

8. The lubricating method according to claim 7 , wherein the at least one additive (C) has an amount of from 0.01 to 20% by mass based on a whole amount of the grease composition.

9. The lubricating method according to claim 1 , wherein the lubricating the bearing comprises lubricating a bearing of a drive motor for an electric vehicle, a hybrid vehicle, and a plug-in hybrid vehicle.

10. A bearing lubricated by the lubricating method according to claim 1 and used under the high-speed rotation condition with a DN value of 100,000 or more.

11. The lubricating method according to claim 1 , wherein the urea-based thickener (B) comprises a diurea compound represented by formula (b1):
R 1 —NHCONH—R 3 —NHCONH—R 2   (b1)

wherein R 1 and R 2 each independently represent a monovalent hydrocarbon group having 6 to 24 carbon atoms, R 1 and R 2 may be the same as or different from each other, and R 3 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

Assignees

• Idemitsu Kosan Co

Inventors

• Takane Kouji
• Watanabe Go
• Shishikura Akihiro
• Yamashita Jun

Classifications

• C10M169/00 Primary

  Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential · CPC title

• C10M101/02

  Petroleum fractions · CPC title

• C10M107/02

  Hydrocarbon polymers; Hydrocarbon polymers modified by oxidation · CPC title

• C10M115/08

  containing nitrogen · CPC title

• C10M129/74

  of polyhydroxy compounds · CPC title