US 11,993,757 B2
Lubricating oil composition for shock absorber, additive for friction adjustment, lubricating oil additive, shock absorber, and method for adjusting friction of shock absorber lubricating oil
Shinji Kato, Tokyo (JP)
Assigned to KYB CORPORATION, Tokyo (JP)
Appl. No. 17/285,175
Filed by KYB Corporation, Tokyo (JP)
PCT Filed Dec. 24, 2019, PCT No. PCT/IB2019/061323
§ 371(c)(1), (2) Date Apr. 14, 2021,
PCT Pub. No. WO2020/084606, PCT Pub. Date Apr. 30, 2020.
Claims priority of application No. 2018-201824 (JP), filed on Oct. 26, 2018.
Prior Publication US 2021/0380897 A1, Dec. 9, 2021
Int. Cl. C10M 141/10 (2006.01); C10M 169/04 (2006.01); C10N 10/04 (2006.01); C10N 30/06 (2006.01); C10N 40/08 (2006.01)
CPC C10M 141/10 (2013.01) [C10M 169/04 (2013.01); C10M 2207/022 (2013.01); C10M 2207/283 (2013.01); C10M 2223/045 (2013.01); C10N 2010/04 (2013.01); C10N 2030/06 (2013.01); C10N 2040/08 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A shock absorber including a lubricating oil composition, the lubricating oil composition comprising:
a base oil; and
a friction adjusting agent, wherein
the friction adjusting agent contains zinc dithiophosphate and pentaerythritol esters and/or pentaerythritol derivatives,
the zinc dithiophosphate has at least one secondary alkyl group having 3 to 5 carbon atoms,
wherein
the pentaerythritol esters and/or pentaerythritol derivatives are contained in 2 to 5 wt. % based on total amount of the lubricating oil composition,
the pentaerythritol esters and/or pentaerythritol derivatives contain pentaerythritol tetraester and/or pentaerythritol tetraester derivative, and
all four terminal substituents of the pentaerythritol tetraester and/or pentaerythritol tetraester derivative are ester-bonded oleic acid residues.