The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 2012
Filed:
Apr. 21, 2008
Applicant:
Toshiyuki Tsubouchi, Sodegaura, JP;
Inventor:
Toshiyuki Tsubouchi, Sodegaura, JP;
Assignee:
Idemitsu Kosan Co., Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C10M 129/68 (2006.01);
U.S. Cl.
CPC ...
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.