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:
Dec. 04, 2018
Filed:
Mar. 16, 2016
Idemitsu Kosan Co., Ltd., Chiyoda-ku, JP;
Yoshiyuki Suetsugu, Kisarazu, JP;
IDEMITSU KOSAN CO., LTD., Chiyoda-ku, JP;
Abstract
A viscosity index improver including a comb-shaped polymer is provided. For a solution having the viscosity index improver dissolved in a mineral oil and having a solid component concentration of 25 mass %, a ratio of the storage modulus (G') to the loss modulus (G″) of the solution measured at a measuring temperature of 70° C. is 0.40 or more. For a solution (α) at 25° C. having the viscosity index improver dissolved in a mineral oil and having a solid component concentration of 25 mass % and a solution (β) resulting from subjecting the solution (α) to heating to 100° C. at a prescribed temperature rise rate and then cooling to 25° C. at a prescribed cooling rate, a ratio of the storage modulus (G′) of the solution (β) to the storage modulus (G′) of the solution (α) measured at a measuring temperature of 25° C. is 2.0 or more.