A lubricating oil composition for internal combustion engines, including a lubricant base oil and a liquid random copolymer of ethylene and an α-olefin, the liquid random copolymer being produced using a specific catalyst, wherein the lubricating oil composition has a kinematic viscosity at 100° C. of 12.5 mm.sup.2/s or more, but less than 26.1 mm.sup.2/s, and wherein the lubricant base oil consists of a mineral oil having a kinematic viscosity at 100° C. of 2 to 10 mm.sup.2/s, a viscosity index of 95 or more and a pour point of −10° C. or lower, and/or a synthetic oil having a kinematic viscosity at 100° C. of 1 to 10 mm.sup.2/s, a viscosity index of 120 or more and a pour point of −30° C. or lower.

A lubricating oil composition for internal combustion engines, including a lubricant base oil and a liquid random copolymer of ethylene and an α-olefin, the liquid random copolymer being produced using a specific catalyst, wherein the lubricating oil composition has a kinematic viscosity at 100° C. of 12.5 mm.sup.2/s or more, but less than 26.1 mm.sup.2/s, and wherein the lubricant base oil consists of a mineral oil having a kinematic viscosity at 100° C. of 2 to 10 mm.sup.2/s, a viscosity index of 95 or more and a pour point of −10° C. or lower, and/or a synthetic oil having a kinematic viscosity at 100° C. of 1 to 10 mm.sup.2/s, a viscosity index of 120 or more and a pour point of −30° C. or lower.

The present invention relates to copolymers, to a method for the preparation of these copolymers, to the use of these copolymers for reducing wear in a lubricant composition, to lubricant compositions comprising these copolymers, and to the use of these lubricant compositions as an automatic transmission fluid, a continuously variable transmission fluid, an engine oil, a gear oil, or a hydraulic oil.

The present invention relates to copolymers, to a method for the preparation of these copolymers, to the use of these copolymers for reducing wear in a lubricant composition, to lubricant compositions comprising these copolymers, and to the use of these lubricant compositions as an automatic transmission fluid, a continuously variable transmission fluid, an engine oil, a gear oil, or a hydraulic oil.

A lubricating oil composition for hydraulic oils including 10 to 99% by mass of a lubricant base oil (A) with a kinematic viscosity at 100° C. of 1 to 14 mm.sup.2/s, a viscosity index of 100 or more, and a pour point of 0° C. or lower, and 90 to 1% by mass of a liquid random copolymer (B) of ethylene and α-olefin prepared using a specific catalyst, wherein the total amount of (A) and (B) is 100% by mass, and having a kinematic viscosity at 100° C. of 10 to 300 mm.sup.2/s.

A lubricating oil composition for hydraulic oils including 10 to 99% by mass of a lubricant base oil (A) with a kinematic viscosity at 100° C. of 1 to 14 mm.sup.2/s, a viscosity index of 100 or more, and a pour point of 0° C. or lower, and 90 to 1% by mass of a liquid random copolymer (B) of ethylene and α-olefin prepared using a specific catalyst, wherein the total amount of (A) and (B) is 100% by mass, and having a kinematic viscosity at 100° C. of 10 to 300 mm.sup.2/s.

A lubricating oil composition for automobile transmissions including a lubricant base oil, and a liquid random copolymer of ethylene and α-olefin, the liquid random copolymer being produced using a specific catalyst, wherein the lubricating oil composition has a kinematic viscosity at 100° C. of 4.0 to 7.5 mm.sup.2/s, and a Brookfield viscosity at −40° C. of 20,000 mPa.Math.s or less, and wherein the lubricant base oil consists of a mineral oil with a kinematic viscosity at 100° C. of 2 to 10 mm.sup.2/s, a viscosity index of 105 or more, and a pour point of −10° C. or lower, and/or a synthetic oil with a kinematic viscosity at 100° C. of 1 to 10 mm.sup.2/s, a viscosity index of 120 or more, and a pour point of −30° C. or lower.

A lubricating oil composition for automobile transmissions including a lubricant base oil, and a liquid random copolymer of ethylene and α-olefin, the liquid random copolymer being produced using a specific catalyst, wherein the lubricating oil composition has a kinematic viscosity at 100° C. of 4.0 to 7.5 mm.sup.2/s, and a Brookfield viscosity at −40° C. of 20,000 mPa.Math.s or less, and wherein the lubricant base oil consists of a mineral oil with a kinematic viscosity at 100° C. of 2 to 10 mm.sup.2/s, a viscosity index of 105 or more, and a pour point of −10° C. or lower, and/or a synthetic oil with a kinematic viscosity at 100° C. of 1 to 10 mm.sup.2/s, a viscosity index of 120 or more, and a pour point of −30° C. or lower.

A lubricating oil composition for automobile gears, including a lubricant base oil and a liquid random copolymer of ethylene and α-olefin(s), the liquid random copolymer being produced using a specific catalyst, wherein the lubricating oil composition has a kinematic viscosity at 100° C. of 7 to 30 mm.sup.2/s, and wherein the lubricant base oil consists of a mineral oil having a kinematic viscosity at 100° C. of 2 to 10 mm.sup.2/s, a viscosity index of 105 or more and a pour point of −10° C. or lower, and/or a synthetic oil having a kinematic viscosity at 100° C. of 1 to 10 mm.sup.2/s, a viscosity index of 120 or more and a pour point of −30° C. or lower.

A lubricating oil composition for automobile gears, including a lubricant base oil and a liquid random copolymer of ethylene and α-olefin(s), the liquid random copolymer being produced using a specific catalyst, wherein the lubricating oil composition has a kinematic viscosity at 100° C. of 7 to 30 mm.sup.2/s, and wherein the lubricant base oil consists of a mineral oil having a kinematic viscosity at 100° C. of 2 to 10 mm.sup.2/s, a viscosity index of 105 or more and a pour point of −10° C. or lower, and/or a synthetic oil having a kinematic viscosity at 100° C. of 1 to 10 mm.sup.2/s, a viscosity index of 120 or more and a pour point of −30° C. or lower.