US 12,187,977 B2
Water-glycol hydraulic fluid
Hiroshi Kaneko, Minato-ku (JP)
Assigned to Shell USA, Inc., Houston, TX (US)
Appl. No. 18/248,697
Filed by SHELL OIL COMPANY, Houston, TX (US)
PCT Filed Nov. 9, 2021, PCT No. PCT/EP2021/081109
§ 371(c)(1), (2) Date Apr. 12, 2023,
PCT Pub. No. WO2022/101198, PCT Pub. Date May 19, 2022.
Claims priority of application No. 2020-187749 (JP), filed on Nov. 11, 2020.
Prior Publication US 2023/0383214 A1, Nov. 30, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C10M 173/02 (2006.01); C10M 105/14 (2006.01); C10M 129/93 (2006.01); C10M 137/10 (2006.01); C10M 141/10 (2006.01); C10N 40/08 (2006.01)
CPC C10M 173/02 (2013.01) [C10M 105/14 (2013.01); C10M 129/93 (2013.01); C10M 137/105 (2013.01); C10M 141/10 (2013.01); C10M 2201/02 (2013.01); C10M 2207/0225 (2013.01); C10M 2207/129 (2013.01); C10M 2223/047 (2013.01); C10N 2040/08 (2013.01)] 2 Claims
 
1. A water-glycol hydraulic fluid comprising:
from 20 to 60% by mass of water and from 20 to 60% by mass of glycol;
0.2% by mass or more and 0.6% by mass or less of a dimer acid as a fatty acid lubricant, wherein the dimer acid is a dibasic acid of a dicarboxylic acid having 36 carbon atoms; and
from 0.15% to 0.20% by mass of a phosphoric acid ester represented by general formula (1) below,

OG Complex Work Unit Chemistry
wherein
R1 and R2 may be the same or different, each representing a hydrogen atom or a hydrocarbon group having from 1 to 30 carbon atoms, R3 represents a hydrocarbon group having from 1 to 20 carbon atoms, R4 represents a hydrogen atom or a hydrocarbon group having from 1 to 30 carbon atoms, and X1, X2, X3 and X4 may be the same or different, each representing an oxygen atom or a sulfur atom, and wherein
the sum of the dimer acid and the phosphoric acid ester is more than 0.35% by mass.