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:
Sep. 18, 2012
Filed:
Nov. 15, 2006
Hiroshi Fujita, Chiba, JP;
Hiroshi Fujita, Chiba, JP;
Idemitsu Kosan Co., Ltd., Tokyo, JP;
Abstract
The invention provides a transmission fluid composition which has a kinematic viscosity as determined at 100° C. of 2 to 10 mm/s and a viscosity index of 150 or higher and which satisfies a relationship between kinematic viscosity and NOACK evaporation loss amount represented by formula (I):/3+≦6.33  (I)(wherein X represents a kinematic viscosity (mm/s) as determined at 100° C., and Y represents a NOACK evaporation loss amount (mass %) at 200° C. for one hour), and a transmission fluid composition containing, as a base oil, at least one species selected from among α-olefin oligomers produced through oligomerization of an α-olefin through a specific method and hydrogenation products of the oligomers. Such transmission fluid compositions exhibit a very small evaporation loss despite having low viscosity, and a long metal fatigue life (e.g., pitting resistance) and have high viscosity index, good low-temperature fluidity, good extreme pressure properties, and good oxidation stability, and are suitable for transmissions, particularly automatic transmissions.