COPOLYMER, LUBRICATING OIL VISCOSITY MODIFIER, AND LUBRICATING OIL COMPOSITION

摘要

A copolymer containing a constituent unit derived from ethylene and a constituent unit derived from an ±-olefin having 3 to 20 carbon atoms and satisfying the following requirements (1) to (5): (1) the copolymer has a melting point (Tm) of -20°C to 100°C; (2) the melting point (Tm) and the density D (g/cm 3 ) satisfy the following expression Tm‰¥1073×D-893 (1); (3) the copolymer has a molecular weight distribution (Mw/Mn) measured by GPC of 1.6 to 5.0; (4) the copolymer has a half-width (”Thalf) of a melting peak measured by DSC of 90°C or less; and (5) the half-width (”Thalf) and the melting point (Tm) satisfy the relationship shown by the following expression ”Thalf‰¤-0.71×Tm+101.4 (2).