Grease composition

Patent metadata

Field	Value
Publication number	US-12378498-B2
Application number	US-202218550984-A
Country	US
Kind code	B2
Filing date	Mar 31, 2022
Priority date	Mar 31, 2021
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

A grease composition, containing a base oil (A), a urea-based thickener (B), and a polymer compound (C). The particles that make up the urea-based thickener (B) in the grease composition satisfy the following requirement (I): the particles have an arithmetic average particle diameter on an area basis as measured by a laser diffraction/scattering method of 2.0 μm or less, and the polymer compound (C) has a number average molecular weight (Mn) of 30,000 or more and a molecular weight distribution (Mw/Mn) of 2.20 or less.

First claim

The invention claimed is:

1. A grease composition, comprising:
a base oil;
a urea-based thickener comprising a diurea compound; and
a polymer compound comprising an ethylene-propylene copolymer or an ethylene-butylene copolymer,
wherein the diurea compound of the urea-based thickener has formula, R 1 -NHCONH-R 3 -NHCONH-R 2 , where R 1 and R 2 are each independently a hydrocarbon group having 6 to 18 carbon atoms, R 3 is a diphenylmethylene group, and the urea-based thickener is in an amount in a range of 4.0% by mass to 7.0% by mass based on a total amount of the grease composition, particles that comprise the urea-based thickener have an arithmetic average particle diameter on an area basis as measured by a laser diffraction/scattering method of 2.0 μm or less, and the polymer compound has a number average molecular weight of 30,000 or more and a molecular weight distribution of 2.20 or less and is in an amount in a range of 1.0% by mass to 2.3% by mass based on the total amount of the grease composition.

2. The grease composition according to claim 1 , wherein the particles that comprise the urea-based thickener have a specific surface area as measured by a laser diffraction/scattering method of 0.5×10 5 cm 2 /cm 3 or more.

3. The grease composition according to claim 1 , wherein the polymer compound comprises the ethylene-propylene copolymer.

4. The grease composition according to claim 3 , wherein the ethylene-propylene copolymer has an ethylene content in a range of 40% by mass to 60% by mass based on the total amount of the ethylene-propylene copolymer.

5. The grease composition according to claim 1 , wherein the base oil has a 40° C. kinematic viscosity of 10 mm 2 /s to 150 mm 2 /s.

6. The grease composition according to claim 1 , wherein a content of the urea-based thickener to the polymer compound is a mass ratio in a range of 1.0 to 4.5.

7. The grease composition according to claim 1 , wherein the grease composition has a worked penetration of 250 to 350.

8. A lubrication method, comprising:
lubricating a sliding mechanism in which a metal material and a resin material slide on each other with the grease composition of claim 1 .

9. A grease composition, comprising:
a base oil;
a urea-based thickener; and
a polymer compound,
wherein particles that comprise the urea-based thickener have an arithmetic average particle diameter on an area basis as measured by a laser diffraction/scattering method of 2.0 μm or less, the polymer compound has a number average molecular weight of 30,000 or more and a molecular weight distribution of 2.20 or less, and the urea-based thickener is present in an amount in a range of 1.0% by mass to 6.5% by mass based on a total amount of the grease composition.

10. The grease composition according to claim 2 , wherein the polymer compound comprises the ethylene-propylene copolymer.

11. The grease composition according to claim 10 , wherein the ethylene-propylene copolymer has an ethylene content in a range of 40% by mass to 60% by mass based on the total amount of the ethylene-propylene copolymer.

12. The grease composition according to claim 2 , wherein the base oil has a 40° C. kinematic viscosity of 10 mm 2 /s to 150 mm 2 /s.

13. The grease composition according to claim 2 , wherein a content of the urea-based thickener to the polymer compound is a mass ratio in a range of 1.0 to 4.5.

14. The grease composition according to claim 2 , wherein the grease composition has a worked penetration of 250 to 350.

15. The grease composition according to claim 2 , wherein the urea-based thickener is present in an amount in a range of 4.0% by mass to 6.5% by mass based on the total amount of the grease composition.

16. The grease composition according to claim 1 , wherein the urea-based thickener is present in an amount in a range of 5.2% by mass to 7.0% by mass based on the total amount of the grease composition.

17. The grease composition according to claim 1 , wherein the base oil is present in an amount in a range of 91.0% by mass to 95.0% by mass based on the total amount of the grease composition.

18. The grease composition according to claim 1 , wherein the base oil is present in an amount in a range of 91.0% by mass to 92.8% by mass based on the total amount of the grease composition.

19. The grease composition according to claim 1 , wherein R 1 and R 2 each independently are a cyclohexyl group, an octadecyl group or an octyl group.

20. The grease composition according to claim 1 , wherein a content of the urea-based thickener to the polymer compound is a mass ratio in a range of 2.6 to 3.5.

Assignees

• Idemitsu Kosan Co

Inventors

• Inda Keisuke
• Watanabe Go
• Takane Kouji

Classifications

• C10N2040/04

  Oil-bath; Gear-boxes; Automatic transmissions; Traction drives · CPC title

• C10N2020/04

  Molecular weight; Molecular weight distribution · CPC title

• C10N2020/02

  Viscosity; Viscosity index · CPC title

• C10M2290/10

  Thickener · CPC title

• C10M2215/28

  Amides; Imides · CPC title