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:
Mar. 07, 2000
Filed:
Feb. 17, 1999
Applicant:
Inventor:
Robert Barnett Rhodes, Houston, TX (US);
Assignee:
Shell Oil Company, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C10M / ; C08F / ;
U.S. Cl.
CPC ...
508591 ; 585 11 ; 585 13 ; 525314 ; 525316 ;
Abstract
The present invention includes star polymers which can be used as viscosity index improvers in oil compositions formulated for high performance engines. The star polymers have tetrablock copolymer arms of hydrogenated polyisoprene-polybutadiene-polyisoprene with a block of polystyrene and which provide excellent low temperature performance in lubricating oils, exhibit good thickening efficiency, and are finishable as polymer crumb.