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:
Oct. 17, 1995
Filed:
Aug. 11, 1994
Applicant:
Inventors:
Robert B Rhodes, Houston, TX (US);
Craig A Stevens, Houston, TX (US);
Assignee:
Shell Oil Company, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C10M / ; C08F / ; C08F / ; C08F / ;
U.S. Cl.
CPC ...
252 43 ; 525314 ; 585 11 ;
Abstract
The present invention includes asymmetric triblock copolymers which are used as viscosity index improvers in oil compositions formulated for high performance engines. The triblock copolymers have the block structure hydrogenated polyisoprene-polystyrene-hydrogenated polyisoprene wherein the ratio of the number average molecular weights of the first and second hydrogenated polyisoprene blocks is at least 4.