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:
Feb. 25, 2003
Filed:
Jun. 08, 2001
Keiji Okada, Yamaguchi, JP;
Ryousuke Kaneshige, Ichihara, JP;
Other;
Abstract
The present invention is intended to obtain a viscosity modifier for a lubricating oil, by the use of which a lubricating oil composition of excellent low-temperature properties can be obtained, and to obtain a lubricating oil composition of excellent low-temperature properties containing the viscosity modifier. The viscosity modifier for a lubricating oil comprises an ethylene/propylene copolymer (A) having the properties: the density is in the range of 857 to 882 kg/m , Mw is in the range of 80,000 to 400,000, Mw/Mn is not more than 2.3, and the density (D (kg/m )) and the melting point (Tm (° C.)) satisfy the relation Tm≦1.247×D−1037; or comprises an ethylene/propylene copolymer (B) having the properties: the ethylene content is in the range of 70 to 79 wt %, Mw is not less than 80,000 and less than 250,000, Mw/Mn is not more than 2.3, Tm is in the range of 15 to 60° C., and the ethylene content (E (wt %)) and the melting point (Tm (° C.)) satisfy the relation 3.44×E−206≧Tm; or comprises an ethylene/propylene copolymer (C) having the properties: the ethylene content is in the range of 70 to 79 wt %, Mw is in the range of 250,000 to 400,000, Mw/Mn is not more than 2.3, Tm is in the range of 15 to 60° C., and the ethylene content (E (wt %)) and the melting point (Tm (° C.)) satisfy the relation 3.44×E−204≧Tm. The lubricating oil composition comprises the ethylene/propylene copolymer (A) (B) or (C), a lubricating oil base (D), and if necessary, a pour point depressant.