| abstract |
A railway diesel engine lubricating composition is essentially free of zinc dithiophosphate wear inhibitors and chlorinated inhibitors. This composition has an oil of lubricating viscosity; a noncarbonated sulfurized calcium alkyl phenate, a carbonated sulfurized calcium alkyl phenate, a calcium Mannich alkyl phenate, and an ethylene carbonate modified polybutene bis-succinimide. The noncarbonated sulfurized calcium alkyl phenate has a sulfur to metal ratio of between 1.1:1 and 2:1, the alkyl group of that phenate has from 8 to 35 carbon atoms, and the alkalinity value of that phenate is from 40 to 200 mg. KOH/gram. The noncarbonated sulfurized metal alkyl phenate is prepared by reacting a tetrapropylene phenol, sulfur, and a calcium base. |