# US 8,785,359 B2 · Lubricant oil composition

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- Number: US 8,785,359 B2
- Document ID: US8785359B2
- Status: Granted
- Kind: B2
- Application number: 13/375,061
- Filed: 2010-01-25
- Published: 2012-03-22
- Granted: 2014-07-22
- Earliest claimed: 2009-06-04
- Assignees: Jx Nippon Oil & Energy Corporation
- Applicants: Akira Yaguchi; Shigeki Matsui; Teppei Tsujimoto
- Inventors: Akira Yaguchi; Shigeki Matsui; Teppei Tsujimoto
- Web page: https://patentgrep.com/patent/US8785359B2

## CPC

- C10M 169/041: {the additives being macromolecular compounds only}
- C10M 2203/1006: used as base material
- C10M 2203/1025: used as base material
- C10M 2205/022: Ethene
- C10M 2209/084: Acrylate; Methacrylate
- C10N 2020/02: Viscosity; Viscosity index
- C10N 2030/02: Pour-point; Viscosity index
- C10N 2030/68: {Shear stability}
- C10N 2040/25: Internal-combustion engines
- C10M: LUBRICATING COMPOSITIONS (well drilling compositions C09K8/02); USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION (mould release, i.e. separating, agents for metals B22C3/00, for plastics or substances in a plastic state, in general B29C33/56, for glass C03B40/02; textile lubricating compositions D06M11/00, D06M13/00, D06M15/00; immersion oils for microscopy G02B21/33)
- C10N: INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS

## Abstract

A lubricant oil composition comprising: a lubricant base oil whose kinematic viscosity at 100° C. is 1 to 6 mm2/s, % Cp is not less than 70, and % CA is not more than 2; a first viscosity index improver in which the ratio A/B of a viscosity increasing effect A in the equation (1) to a viscosity increasing effect B in the equation (2) when added to the lubricant base oil is a value of not less than 4.5, and a PSSI is not more than 30; and a second viscosity index improver in which the ratio A/B when added to the lubricant base oil is a value less than 4.5: A=X−X0 (1) B=Y−Y0 (2) wherein A represents a viscosity increasing effect of the kinematic viscosity at 100° C., B represents a viscosity increasing effect of the HTHS viscosity at 150° C., X represents a kinematic viscosity at 100° C. of a mixture of the lubricant base oil with 3% by mass of the first or second viscosity index improver, X0 represents a kinematic viscosity at 100° C. of the lubricant base oil, Y represents an HTHS viscosity at 150° C. of a mixture of the lubricant base oil with 3% by mass of the first or second viscosity index improver, and Y0 represents an HTHS viscosity at 150° C. of the lubricant base oil.

## Claims

### Claim 1

A lubricant oil composition comprising:
a lubricant base oil whose kinematic viscosity at 100° C. is 1 to 6 mm2/s, % Cp is not less than 70, and % CA is not more than 2;
a first viscosity index improver in which a ratio A/B of a viscosity increasing effect A of a kinematic viscosity at 100° C. represented by a following equation (1) to a viscosity increasing effect B of an HTHS viscosity at 150° C. represented by a following equation (2) when added to the lubricant base oil is a value of not less than 4.5, and a PSSI is not more than 30; and
a second viscosity index improver in which the ratio A/B of the viscosity increasing effect A of the kinematic viscosity at 100° C. represented by the following equation (1) to the viscosity increasing effect B of the HTHS viscosity at 150° C. represented by the following equation (2) when added to the lubricant base oil is a value less than 4.5:
A=X−X0 (1)
wherein A represents a viscosity increasing effect of the kinematic viscosity at 100° C., X represents a kinematic viscosity at 100° C. [units: mm2/s] of a mixture of the lubricant base oil with 3% by mass of the first or second viscosity index improver, and X0 represents a kinematic viscosity at 100° C. [units: mm2/s] of the lubricant base oil,
B=Y−Y0 (2)
wherein B represents a viscosity increasing effect of the HTHS viscosity at 150° C., Y represents an HTHS viscosity at 150° C. [units: mPa·s] of a mixture of the lubricant base oil with 3% by mass of the first or second viscosity index improver, and Y0 represents an HTHS viscosity at 150° C. [units: mPa·s] of the lubricant base oil.

### Claim 2 (depends on 1)

The lubricant oil composition according to claim 1, wherein the second viscosity index improver is a polymethacrylate with a PSSI of not more than 30.

### Claim 3 (depends on 1)

The lubricant oil composition according to claim 1, wherein the PSSI of the first viscosity index improver is not more than 20, and the second viscosity index improver is a polymethacrylate with a PSSI of not more than 30.