Patent · US Expired

Star polymer viscosity index improver for oil compositions

US5458791A · kind A · utility

9Cited by
17References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 1, 1994
Grant dateOct 17, 1995
Priority date
Expiry dateJul 1, 2014

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S525/901
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

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 triblock copolymer arms of hydrogenated polyisoprene and polystyrene wherein the polystyrene is placed near the core of the star polymer to provide excellent low temperature performance and finishability as a polymer crumb.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.