Patent ID: 6589920
Filing Date: 2003-07-08
Classification: C08F,C10M,C10N

Abstract:
A viscosity modifier for lubricating oil, comprising an ethylene/&agr;-olefin copolymer which is a copolymer of ethylene and an &agr;-olefin of 3 to 20 carbon atoms and has the following properties:(1) the ethylene content (E) is in the range of 40 to 77% by weight, (2) the weight-average molecular weight (Mw) in terms of polystyrene, as measured by GPC, is in the range of 80,000 to 400,000, (3) Mw/Mn is not more than 2.4, (4) the melting point (Tm), as measured by DSC, is not higher than 60Â° C., (5) the ethylene content (E, % by weight) and the melting point (Tm, Â°C.), as measured by DSC, satisfy the following relation (I): 3.31Ã—Eâˆ’186&gE;Tmâ€ƒâ€ƒ(I), and(6) the intensity ratio, S&agr;&bgr;/S&agr;&agr;, measured by 13C-NMR spectrum is not more than 0.5.