Patent ID: 7696139
Filing Date: 2010-04-13
Classification: C10M,C10N

Abstract:
1. A grease composition for a pivot assembly bearing, which comprises: a thickener of 10 to 20% by mass; and a base oil of 90 to 79% by mass with respect to the total mass of the thickener and the base oil, wherein the thickener comprising two or more ureas selected from the group consisting of: urea A comprising diurea compounds having at least one of an aliphatic substituent and an alicyclic substituent; urea B comprising diurea compounds having at least one of an alicyclic substituent and an aromatic substituent; and urea C comprising diurea compounds having at least one of an aromatic substituent and an aliphatic substituent, wherein the base oil is a poly α-olefin mixture having a kinematic viscosity at 40° C. of 40 to 70 mm wherein urea A comprises a mixture of diurea compounds represented by formulae (1), (2) and (3): wherein R urea B comprises a mixture of diurea compounds represented by formulae (2), (4) and (5): wherein R urea C comprises a mixture of diurea compounds represented by formulae (1), (4) and (6): wherein R