LOW NOISE TYPE LITHIUM GREASE COMPOSITION FOR SEALING SMALL-SIZED MOTOR BEARING

摘要

PPROBLEM TO BE SOLVED: To provide an environment-friendly low noise type grease in which rotation sound of a motor is reduced by sealing it into a small-sized motor bearing used for motor bearing for household electric appliances such as air-conditioner, motor bearing, etc., for information machines and equipment such as hard disk driving. PSOLUTION: The grease composition comprises 5-20 mass% thickener and 95-80 mass% base oil. The grease composition uses lithium soap synthesized from lithium hydroxide and a 10-20C higher fatty acid and/or a 10C higher hydroxy fatty having one or more hydroxy groups as the thickener and contains, as a main component, a polymer ester oil (a) arranging 8 ester groups in comb-like shape on one side of a chain molecule of oil composed of 8 carbon atoms represented by general formula 1 (wherein RSB1/SB, RSB2/SB, RSB3/SBand RSB4/SBare each an alkyl group and x is an integer of 2 or more; y is an integer of 2 or more) as a base oil and has 25-80 mmSP2/SP/s base oil viscosity (at 40C). PCOPYRIGHT: (C)2006,JPO&NCIPI