| 摘要 |
A process for the production of a substantially anhydrous lubricating composition comprising a mixture of metal salts of acetic acid and a C7 to C10 monocarboxylic acid, and lubricating oil, consists in heating the mixture to 250-350 DEG F., maintaining the proportion by weight of the said metal salts in the range of 20-50%, homogenizing in the range 80-150 DEG F. with the rate of shear in the range 100,000 to 500,000 reciprocal seconds, diluting with further amounts of lubricating oil, thus giving a concentration of 4-10 wt. per cent of metal salts and homogenizing in the range 80-150 DEG F., with the rate of shear in the range 100,000 to 750,000 reciprocal seconds, to give a fluid product of viscosity 80-200 S.S.U. at 210 DEG F. and said to be of improved stability. The lubricating oil has an initial viscosity in the range 55-100 S.S.U. at 210 DEG F. and a V.I. of 40-100; the molecular ratio of acetic to C7-C12 acid is in the range of 10 : 1 to 25 : 1. It is preferred to form the said mixture of salts in the lubricating oil; the preferred metal is calcium, and it is preferred to homogenize the product containing 20-50 wt. per cent of said salts in at least two stages with intermediate storage between stages. Specific examples use a commercially available mixture of 28% caprylic, 56% capric and 16% lauric acid as the source of C7 to C10 acid, hydrated lime as a source of calcium and 0.6% (based on the composition prior to dilution) of phenyl a -naphthylamine. The lubricating oils of the examples are:- a hydrofined coastal distillate or acid-treated or hydrofined oils derived from naphthenic coastal crude; other oils used may be synthetic, e.g. of the hydrocarbon, hydrocarbon polymer, ester (such as di-2-ethylhexyl sebacate or di-C8- or -C10-oxo azelates), complex ester (e.g. of glycols, dicarboxylic acids and alcohols or monocarboxylic acids), formal, mercaptal, polyalkene oxide, or silicone types. The compositions of this invention are said to be useful for lubricating marine diesel engines. |
