US 12,222,344 B2
Method for using lubricating oil composition and method for evaluating degradation
Moritsugu Kasai, Tokyo (JP); and Tatsuya Kusumoto, Tokyo (JP)
Assigned to Idemitsu Kosan Co., Ltd., Chiyoda-ku (JP)
Appl. No. 17/759,057
Filed by Idemitsu Kosan Co., Ltd., Chiyoda-ku (JP)
PCT Filed Jan. 20, 2021, PCT No. PCT/JP2021/001775
§ 371(c)(1), (2) Date Jul. 19, 2022,
PCT Pub. No. WO2021/149701, PCT Pub. Date Jul. 29, 2021.
Claims priority of application No. 2020-007666 (JP), filed on Jan. 21, 2020.
Prior Publication US 2023/0057229 A1, Feb. 23, 2023
Int. Cl. G01N 33/28 (2006.01); C10M 125/22 (2006.01); C10M 129/52 (2006.01); C10M 129/54 (2006.01); C10M 169/04 (2006.01); G01N 33/30 (2006.01); C10N 10/04 (2006.01); C10N 30/00 (2006.01); C10N 30/04 (2006.01)
CPC G01N 33/2888 (2013.01) [C10M 125/22 (2013.01); C10M 129/52 (2013.01); C10M 129/54 (2013.01); C10M 169/04 (2013.01); G01N 33/30 (2013.01); C10M 2201/084 (2013.01); C10M 2207/142 (2013.01); C10M 2207/144 (2013.01); C10N 2010/04 (2013.01); C10N 2030/04 (2013.01); C10N 2030/52 (2020.05)] 7 Claims
OG exemplary drawing
 
1. A method for using a lubricating oil composition, comprising:
measuring a value of at least one physical property selected from an electrostatic capacity and a dielectric constant of a lubricating oil composition in use; and
evaluating a progress of degradation of the lubricating oil composition from the value of at least one physical property selected from the electrostatic capacity and the dielectric constant of the lubricating oil composition,
wherein a content of a metal-based detergent having a base number of 100 mgKOH/g or less is 630 mass ppm or less in terms of metal atoms in the lubricating oil composition, a content of sulfated ash is 1.5 mass % or less in the lubricating oil composition, and the measuring of the value of at least one physical property comprising measuring the value using at least one comb-type electrode at a single frequency of from 20 Hz to 120 Hz.