Preparation of high dropping point lithium complex soap grease

A process for preparing a lithium soap grease having a dropping point above 500.degree. F. which comprises the steps of:

• (a) dissolving a C.sub.12 to C.sub.24 hydroxy fatty acid and a C.sub.4 to C.sub.12 aliphatic dicarboxylic acid in approximately a 3:1 to 0.5:1 mole ratio range in a lubricating oil to form an oil-acid mixture in which the amount of oil employed comprises about 30 to 50 weight percent of the total amount of oil employed in the finished composition;
• (b) adjusting the oil and acid mixture to a temperature below about the boiling temperature of water;
• (c) adding slowly at a controlled rate of below about 0.30 lbs./minute a concentrated aqueous solution of approximately 8 to 10 weight percent of lithium hydroxide in an amount slightly in excess of that required to neutralize the acids;
• (d) maintaining the reaction conditions for a period of time sufficient to obtain substantially complete saponification between the fatty acids and lithium hydroxide;
• (e) dehydrating the mixture of lubricating oil and lithium complex soap;
• (f) heating the mixture until it is uniformly at a temperature of from about 390.degree. F. to about 430.degree. F.;
• (g) rapidly cooling the mixture to about 375.degree. F. or below by quenching it with approximately 5 to 25 weight percent of the total amount of lubricating oil employed in the finished composition;
• (h) incorporating the remainder of the lubricating oil into the grease composition.