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:
Jul. 04, 2000
Filed:
Sep. 16, 1997
Robert Jude Sutherland, Houston, TX (US);
Shell Oil Company, Houston, TX (US);
Abstract
A lubricating oil composition comprising: (a) from 0.01 to 10 percent by weight of a dispersant viscosity index improver linear diblock copolymer or a radial or star copolymer with each arm having an overall number average molecular weight of 7500 to 250,000 and comprising a block of a conjugated diene having a number average molecular weight of 5000 to 200,000 and a block of a vinyl aromatic hydrocarbon having a number average molecular weight of 2500 to 100,000, and a vinyl aromatic hydrocarbon content of 5 to 50 weight percent, wherein from 5 to 10 N-vinyl imidazole functional groups per molecule have been grafted onto the copolymer; (b) from 5 to 20 percent by weight of a dispersant inhibitor package containing 40 percent by weight less ashless dispersant than is required for use with a non-dispersant viscosity index improver; and (c) from 80 to 95 percent by weight of a base oil.