US 12,410,379 B2
Lubricant oil composition
Kenji Sunahara, Chiyoda-ku (JP); Shoichiro Fujita, Chiyoda-ku (JP); Masaya Kubota, Chiyoda-ku (JP); and Shota Kato, Chiyoda-ku (JP)
Assigned to IDEMITSU KOSAN CO., LTD., Chiyoda-ku (JP)
Appl. No. 18/552,717
Filed by IDEMITSU KOSAN CO., LTD., Chiyoda-ku (JP)
PCT Filed Mar. 18, 2022, PCT No. PCT/JP2022/012548
§ 371(c)(1), (2) Date Sep. 27, 2023,
PCT Pub. No. WO2022/210014, PCT Pub. Date Oct. 6, 2022.
Claims priority of application No. 2021-062421 (JP), filed on Mar. 31, 2021.
Prior Publication US 2024/0182810 A1, Jun. 6, 2024
Int. Cl. C10M 169/04 (2006.01); C10M 145/14 (2006.01); C10M 161/00 (2006.01); C10N 20/04 (2006.01); C10N 30/02 (2006.01); C10N 30/04 (2006.01); C10N 30/06 (2006.01); C10N 40/25 (2006.01)
CPC C10M 169/044 (2013.01) [C10M 145/14 (2013.01); C10M 161/00 (2013.01); C10M 2203/003 (2013.01); C10M 2209/084 (2013.01); C10M 2215/30 (2013.01); C10M 2219/044 (2013.01); C10M 2219/068 (2013.01); C10M 2223/045 (2013.01); C10M 2227/061 (2013.01); C10M 2227/066 (2013.01); C10N 2020/04 (2013.01); C10N 2030/02 (2013.01); C10N 2030/04 (2013.01); C10N 2030/06 (2013.01); C10N 2040/255 (2020.05)] 18 Claims
 
1. A lubricating oil composition, comprising:
a base oil; and
a copolymer comprising a structural unit derived from a monomer having a (meth) acryloyl group and a linear or branched alkyl group having 6 to 24 carbon atoms, a structural unit derived from a monomer having a (meth) acryloyl group and a polar group, a structural unit derived from a monomer having a (meth) acryloyl group and a cyclic structural group,
wherein a content of the structural unit derived from a monomer having a (meth) acryloyl group and a cyclic structural group is in a range of from 7 to 30 mol % based on all structural units of the copolymer, the copolymer has a mass-average molecular weight in a range of 5,000 to 50,000, a content of the copolymer in terms of resin content is in a range of 0.10% by mass to 2.5% by mass based on a total amount of the lubricating oil composition, and the lubricating oil composition has a 100° C. kinematic viscosity of 8.2 mm2/s or less.