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. 29, 2011
Filed:
Feb. 13, 2009
Satoshi Ikeda, Chiba, JP;
Akihiro Matsuda, Ichihara, JP;
Yoshiki Shimokawatoko, Chiba, JP;
Junichi Mohri, Sanbu-gun, JP;
Toshiyuki Shimazaki, Chiba, JP;
Hiroshi Terao, Ichihara, JP;
Koji Takeda, Ichihara, JP;
Satoshi Ikeda, Chiba, JP;
Akihiro Matsuda, Ichihara, JP;
Yoshiki Shimokawatoko, Chiba, JP;
Junichi Mohri, Sanbu-gun, JP;
Toshiyuki Shimazaki, Chiba, JP;
Hiroshi Terao, Ichihara, JP;
Koji Takeda, Ichihara, JP;
Mitsui Chemicals, Inc., Tokyo, JP;
Abstract
Copolymers when used as lubricating oil viscosity modifiers enable lubricating oils to show excellent low-temperature properties. Processes for producing the copolymers are disclosed. Lubricating oil viscosity modifiers and lubricating oil compositions contain the copolymers. A copolymer includes structural units derived from ethylene and structural units derived from a C3-20 α-olefin and satisfies the following requirements (1) to (8): (1) the melting point (Tm) according to DSC is in the range of 0 to 60° C.; (2) the melting point (Tm) and the density D (g/cm) satisfy the equation: Tm≧1073×D−893; (3) Mw/Mn according to GPC is from 1.6 to 5.0; (4) the half-value width (ΔT) of a melting peak measured by DSC is not more than 90° C.; (5) the half-value width (ΔT) and the melting point (Tm) satisfy the equation: ΔT≦−0.71×Tm+101.4; (6) the heat of fusion (ΔH) as measured by DSC is not more than 60 J/g; (7) the crystallization temperature (Tc) measured by DSC is not more than 70° C.; (8) the heat of fusion (ΔH), the crystallization temperature (Tc), each measured by DSC and the crystallization temperature measured by a CRYSTAF method (T) satisfy the equation: Tc−T≧0.028×ΔH+25.3.