Lubricating oil composition

• US 10,472,583 B2
• Filed: 09/18/2015
• Issued: 11/12/2019
• Est. Priority Date: 09/19/2014
• Status: Active Grant

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Utaka, Toshimasa
• Primary Examiner(s): Vasisth, Vishal V
• Application Number:
  US15/318,837
• Publication Number:
  US 20170137732A1
• Time in Patent Office: 1,516 Days
• Field of Search: 508591, 508195
• CPC Class Codes: C10L 1/1641 from compounds containing aliphatic monomers
• CPC Class Codes: C10L 1/1955 homo- or copolymers of compounds having one or more unsaturated aliphatic radicals each having one carbon bond to carbon double bond, and at least one being terminated by an alcohol, ether, aldehyde, ketonic, ketal, acetal radical
• CPC Class Codes: C10L 1/1973 mono-carboxylic
• CPC Class Codes: C10L 1/2364 homo- or copolymers derived from unsaturated compounds containing amide and/or imide groups C10L1/221 takes precedence
• CPC Class Codes: C10L 10/08 for improving lubricity; for reducing wear
• CPC Class Codes: C10M 169/044 the additives being a mixture of non-macromolecular and macromolecular compounds
• CPC Class Codes: C10M 171/02 Specified values of viscosity or viscosity index
• CPC Class Codes: C10M 2203/1025 used as base material
• CPC Class Codes: C10M 2205/02 containing acyclic monomers
• CPC Class Codes: C10M 2205/022 Ethene
• CPC Class Codes: C10M 2205/028 containing aliphatic monomers having more than four carbon atoms
• CPC Class Codes: C10M 2207/023 having hydroxy groups bound to carbon atoms of six-membered aromatic rings
• CPC Class Codes: C10M 2207/026 with tertiary alkyl groups
• CPC Class Codes: C10M 2207/262 derived from hydroxy substituted aromatic acids, e.g. salicylates
• CPC Class Codes: C10M 2209/04 containing monomers having an unsaturated radical bound to an alcohol or ester thereof; bound to an aldehyde, ketonic, ether, ketal or acetal radical
• CPC Class Codes: C10M 2209/084 Acrylate; Methacrylate
• CPC Class Codes: C10M 2215/064 Di- and triaryl amines
• CPC Class Codes: C10M 2215/28 Amides; Imides
• CPC Class Codes: C10M 2217/024 containing monomers having an unsaturated radical bound to an amido or imido group
• CPC Class Codes: C10M 2223/045 Metal containing thio derivatives
• CPC Class Codes: C10M 2227/00 : Organic non-macromolecular compounds containing atoms of elements not provided for in groups C10M2203/00, C10M2207/00, C10M2211/00, C10M2215/00, C10M2219/00 or C10M2223/00 as ingredients in lubricant compositions
• CPC Class Codes: C10M 2229/02 : Unspecified siloxanes; Silicones
• CPC Class Codes: C10N 2010/02 : Groups 1 or 11
• CPC Class Codes: C10N 2010/04 : Groups 2 or 12
• CPC Class Codes: C10N 2010/12 : Groups 6 or 16
• CPC Class Codes: C10N 2020/017 : Specific gravity or density
• CPC Class Codes: C10N 2020/02 : Viscosity; Viscosity index
• CPC Class Codes: C10N 2020/04 : Molecular weight; Molecular weight distribution
• CPC Class Codes: C10N 2020/071 : Branched chain compounds
• CPC Class Codes: C10N 2030/02 : Pour-point; Viscosity index
• CPC Class Codes: C10N 2030/04 : Detergent property or dispersant property
• CPC Class Codes: C10N 2030/06 : Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2030/10 : Inhibition of oxidation, e.g. anti-oxidants
• CPC Class Codes: C10N 2030/18 : Anti-foaming property
• CPC Class Codes: C10N 2030/68 : Shear stability
• CPC Class Codes: C10N 2060/14 : by boron or a compound containing boron

Abstract

The present invention provides a lubricating oil composition including a viscosity index improver (A) containing a comb-shaped polymer and having an SSI (shear stability index) of 30 or less together with a base oil, wherein an HTHS viscosity (high temperature high shear viscosity) at 150° C. (T₁₅₀) is 1.6 to 2.9 mPa·s, and a ratio of a kinematic viscosity at 40° C. (V₄₀) [mm²/s] to the HTHS viscosity at 150° C. (T₁₅₀) [mPa·s] (V₄₀/T₁₅₀) is 12.4 or less. The lubricating oil composition of the present invention is excellent in fuel consumption reducing properties in a low-temperature region assuming the time of starting an engine while making various properties, such as a viscosity, etc., in a high-temperature region assuming the time of high-speed operation of an engine favorable.

Claims

1. A lubricating oil composition, comprising:

a viscosity index improver; and

a base oil;

wherein;

the viscosity index improver comprises a comb-shaped polymer;

the comb-shaped polymer has a molecular weight distribution Mw/Mn of 1.01 or greater and less than 2.00, where Mw represents a weight average molecular weight of the comb-shaped polymer, and Mn represents a number average molecular weight of the comb-shaped polymer;

the comb-shaped polymer has a weight average molecular weight of 330,000 to 600,000;

a content of the comb-shaped polymer in the viscosity index improver is 60 to 100 mass % based on a total amount of a solid component in the viscosity index improver;

the comb-shaped polymer is present in an amount of 0.90 to 4.00 mass % based on the total mass of the composition;

the viscosity index improver has a shear stability index of 30 or less;

the base oil comprises a Group 3 mineral oil;

the base oil has a kinematic viscosity at 100°

C. in mm²/s of 2.0 to 7.0;

the base oil is present in an amount of 70 to 95 mass % based on the total mass of the composition;

the lubricating oil composition has a high temperature high shear viscosity at 150°

C. of 1.6 to 2.9 mPa·

s; and

a ratio of a kinematic viscosity at 40°

C. in mm²/s of the lubricating oil composition to the high temperature high sheer viscosity at 150°

C. of the lubricating oil composition is 8.00 to 12.4.

2. The lubricating oil composition according to claim 1, wherein the comb-shaped polymer is a polymer comprising at least a constituent unit derived from a macromonomer.

3. The lubricating oil composition according to claim 1, further comprising at least one additive for lubricating oil selected from the group consisting of a metal-based detergent, a dispersant, an anti-wear agent, an extreme pressure agent, an antioxidant, a pour-point depressant, and an anti-foaming agent.

4. The lubricating oil composition according to claim 3, which comprises the metal-based detergent, which is an organic metal-based compound containing a metal atom selected from the group consisting of an alkali metal atom and an alkaline earth metal atom.

5. The lubricating oil composition according to claim 1, wherein a kinematic viscosity at 100°

C. of the lubricating oil composition is 4.0 to 12.5 mm²/s.

6. The lubricating oil composition according to claim 1, wherein a kinematic viscosity at 40°

C. of the lubricating oil composition is 10.0 to 40.0 mm²/s.

7. The lubricating oil composition according to claim 1, wherein a viscosity index of the lubricating oil composition is 140 or more.

8. The lubricating oil composition according to claim 1, wherein a content of a polymethacrylate-based compound which is not the comb-shaped polymer is 0 to 30 parts by mass based on 100 parts by mass of the comb-shaped polymer contained in the lubricating oil composition.

9. A method for improving fuel consumption reducing property, the method comprising adding the lubricating oil composition according to claim 1 to a fuel in a low-temperature region at 10 to 60°

C.

11. The lubricating oil composition according to claim 1, wherein a ratio of a kinematic viscosity of the lubricating oil composition at 40°

C. mm²/s to the high temperature high sheer viscosity of the lubricating oil composition at 150°

C. is 8.00 to 11.2.

12. The lubricating oil composition according to claim 1, wherein the comb-shaped polymer has a weight average molecular weight of 360,000 to 600,000.

13. The lubricating oil composition according to claim 1, further comprising:

a dispersant;

an anti-wear agent;

an anti-foaming agent;

a metal-based detergent; and

an antioxidant.

14. The lubricating oil composition according to claim 13, wherein:

the dispersant comprises at least one of a high-molecular weight bisimide and a boron-modified monoimide;

the anti-wear agent comprises at least one of a primary zinc dialkyldithiophosphate and a secondary zinc dialkyldithiophosphate; and

the anti-foaming agent comprises a silicone-based anti-foaming agent.

10. A method for producing a lubricating oil composition, the method comprising:

blending a base oil with a viscosity index improver to obtain the lubricating oil composition;

wherein;

the viscosity index improver comprises a comb-shaped polymer;

the comb-shaped polymer has a molecular weight distribution Mw/Mn of 1.01 or greater and less than 2.00, where Mw represents a weight average molecular weight of the comb-shaped polymer, and Mn represents a number average molecular weight of the comb-shaped polymer;

the comb-shaped polymer has a weight average molecular weight of 330,000 to 600,000;

a content of the comb-shaped polymer in the viscosity index improver is 60 to 100 mass % based on a total amount of a solid component in the viscosity index improver;

the comb-shaped polymer is present in an amount of 0.90 to 4.00 mass % based on the total mass of the composition;

the viscosity index improver has a shear stability index of 30 or less;

the base oil comprises a Group 3 mineral oil;

the base oil has a kinematic viscosity at 100°

C. in mm²/s of 2.0 to 7.0;

the base oil is present in an amount of 70 to 95 mass % based on the total mass of the composition;

the lubricating oil composition has a high temperature high shear viscosity at 150°

C. of 1.6 to 2.9 mPa·

s; and

a ratio of a kinematic viscosity of the lubricating oil composition at 40°

C. mm²/s to the high temperature high sheer viscosity of the lubricating oil composition at 150°

C. is 8.00 to 12.4.

15. The method according to claim 10, wherein the comb-shaped polymer has a weight average molecular weight of 360,000 to 600,000.

16. The method according to claim 10, wherein:

blending comprises blending a dispersant, an anti-wear agent, an anti-foaming agent, and a metal-based detergent together with the base oil and the viscosity index improver to obtain the lubricating oil composition.

17. The method according to claim 16, wherein:

the dispersant comprises at least one of a high-molecular weight bisimide and a boron-modified monoimide;

the anti-wear agent comprises at least one of a primary zinc dialkyldithiophosphate and a secondary zinc dialkyldithiophosphate; and

the anti-foaming agent comprises a silicone-based anti-foaming agent.