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. 07, 2021
Filed:
Sep. 07, 2017
Shell Oil Company, Houston, TX (US);
Ryuji Maruyama, Aikoh-Gun, JP;
Genki Kamei, Aikoh-Gun, JP;
SHELL OIL COMPANY, Houston, TX (US);
Abstract
The invention provides a lubricating oil composition for automatic transmissions is made such that it comprises proportionately as its main constituents: 60 to 98 mass % as low viscosity base oils being base oils belonging to Groups 2 to 4 of the API (American Petroleum Institute) base oil categories wherein the kinematic viscosity at 100° C. is 2 to 5 mm/s (Fischer-Tropsch synthetic oil comprising at least 45 to 80 mass %); 1 to 20 mass % as high-viscosity base oils being metallocene/poly-α-olefins with a kinematic viscosity at 100° C. of 100 to 600 mm/s; and 1 to 20 mass % being a polymethacrylate with a weight-average molecular weight of 10,000 to 50,000. The viscosity index of this composition is not less than 190, the Brookfield viscosity at −40° C. is not more than 5000 mPa·s, the 100° C. kinematic viscosity is 5 to 7 mm/s, and the rate of reduction of the 100° C. kinematic viscosity after a KRL shear stability test (60° C., 20 hr) is not more than 3%.