| 摘要 |
A process for preparing synthetic lubricants comprises adding urea to one or more defined synthetic base fluids, heating at a temperature of 125-250 DEG C., and removing the precipitants therefrom. The base fluids include the following: (a) diesters of aliphatic dicarboxylic acids, (b) esters of aromatic polycarboxylic acids, (c) complex glycol centred esters including those containing recurring ether linkages, (d) esters derived from a monobasic acid and an alkane polyol, (e) alkyl-terminated polyesters, (f) hydroxy-terminated polyesters, (g) polyalkylene glycol derivatives, and (h) (in Example 3 only) tri-(2-ethylhexy) phosphate. These base fluids are extensively exemplified. Conventional additives which may be present include phenothiazine, di-tert-butyl-p-cresol, and butylated hydroxyanisole.ALSO:Di - [mixed - (2 - ethylhexyl, isodecyl)] azelate, and polypropylene glycol (M.W. 425) azelate are prepared by conventional esterification procedures using tetrabutyl orthotitanate as catalyst. |
