Hydraulic fluid and hydraulic system
AssigneeIdemitsu Kosan Co., Ltd.
InventorToshiyuki Tsubouchi
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Abstract
A hydraulic fluid of the present invention contains, as a base oil, an ester having two or more ring structures, the two or more ring structures being at least one selected from an aromatic ring and a saturated naphthenic ring. Particularly, the hydraulic fluid contains an ester having two or more aromatic rings as the base oil. The hydraulic fluid has low energy loss due to compression and exhibits excellent responsiveness when being used in a hydraulic circuit. Consequently, the hydraulic fluid realizes energy-saving, high-speed operation and high precision of control in the hydraulic circuit.
Claims10
A hydraulic fluid comprising an ester as a base oil, the ester having two or more ring structures, wherein the two or more ring structures are at least one selected from the group consisting of an aromatic ring and a saturated naphthenic ring, and wherein the ester is at least one compound selected from the group consisting of a compound comprising an aromatic ester skeleton of formula (1)
- wherein n is 0 or 1, m is 0, p and q each are an integer of 0 to 3, and X and Y each represent an alkyl group that may include a cycloalkyl group or an aromatic group having 1 to 30 carbon atoms, a cycloalkyl group or an aromatic group having 5 to 12 carbon atoms, an alkyloxycarbonyl group that may include a cycloalkyl group or an aromatic group having 2 to 30 carbon atoms, or an alkylcarbonyloxy group that may include a cycloalkyl group or an aromatic group having 2 to 30 carbon atoms;
- a compound comprising an aromatic ester skeleton of formula (3)
- wherein n and m each are 0 or 1, p and q each are an integer of 0 to 3, R1 and R2 each represent hydrogen or an alkyl group having 1 to 10 carbon atoms, and A represents an alkylene group having 2 to 18 carbon atoms that may contain oxygen in a main chain and may contain a side chain;
- and
- a compound comprising an aromatic ester skeleton of formula (4)
- wherein j and k each are 0 or 1, n and m each are 1 or 2, p and q each are an integer of 0 to 3, R1 and R2 represent hydrogen or an alkyl group having 1 to 10 carbon atoms, and Z represents an alkylene group having 1 to 18 carbon atoms that may include a side chain.
Dependencies are inferred from the claim text.