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:
Apr. 04, 2006
Filed:
Nov. 26, 2003
Keiji Okada, Sodegaura, JP;
Shigenobu Ikenaga, Sodegaura, JP;
Ryousuke Kaneshige, Ichihara, JP;
Tomoaki Matsugi, Sodegaura, JP;
Shinichi Kojoh, Sodegaura, JP;
Terunori Fujita, Sodegaura, JP;
Keiji Okada, Sodegaura, JP;
Shigenobu Ikenaga, Sodegaura, JP;
Ryousuke Kaneshige, Ichihara, JP;
Tomoaki Matsugi, Sodegaura, JP;
Shinichi Kojoh, Sodegaura, JP;
Terunori Fujita, Sodegaura, JP;
Mitsui Chemicals, Inc., Tokyo, JP;
Abstract
The present invention provides an olefin block copolymer for a viscosity index improver capable of preparing a lubricating oil composition having excellent low temperature properties and excellent balance between viscosity and shear stability, a viscosity index improver and a lubricating oil composition comprising the viscosity index improver. The olefin block copolymer has a Mw/Mn of not more than 1.5, and comprises: (i) a polymer block comprising ethylene and an α-olefin of 3 to 20 carbon atoms, having a molar ratio (ethylene/α-olefin) of ethylene units to α-olefin units of from 20/80 to 65/35, a Mw of 50,000 to 2,000,000, and having a slope of an intramolecular composition distribution of absolute value of 0.1 to 0, and (ii) a polymer block comprising ethylene and an α-olefin of 3 to 20 carbon atoms, having a molar ratio (ethylene/α-olefin) of ethylene units to α-olefin units of from 70/30 to 85/15, a Mw of 10,000 to 400,000, and having a slope of an intramolecular composition distribution of absolute value of 0.1 to 0.