| 摘要 |
PURPOSE:To obtain the title composition undergoing little change in consistency after being used at high temperature for a long time, scarcely causing oil separation at high temperature, and improved in shear stability and gelation capability by incorporating a specified diurea compound into a base oil. CONSTITUTION:A mixture of at least two different diisocyanates of formula I (wherein R is linear-chain or branched alkylene, linear-chain or branched alkenylene, cycloalkylene or an aromatic group) (e.g. a mixture of 95-5mol% diphenylmethane 4,4'-diisocyanate and 5-95mol% 4,4'-dicyclohexylmethane diisocyanate) is reacted with an amine compound comprising a primary amine of formula II (wherein R1 is a 6-20C hydrocarbon residue) and/or a secondary amine of formula III (wherein R2 and R3 are each a 6-20C hydrocarbon residue) at 10-200 deg.C to give a diurea compound. A base oil is mixed with 2-25wt.% of the diurea compound and, if necessary, other ingredients such as a gelling agent (e.g. Bentone), an exterme-pressure additive, and a viscosity index improver. |
