GB402262A - Improved lubricating oils - Google Patents

Abstract

A lubricating-oil comprises a hydrocarbon oil containing between about 0.25 and 5.5 per cent of a synthetically produced ester having a boiling point above 302 DEG F. and preferably above 356 DEG F., the lubricating oil being substantially free from suspended matter. For ordinary lubrication, 0.25--2.5 per cent of ester may suitably be used, but for "breaking in" new engines, 2--5.5 per cent is preferable. In general, the oils used have a viscosity of about 45--150 secs. Saybolt at 210 DEG F. The esters used are preferably liquid, but solid esters may be employed. Mixtures of esters may be used, or the esters may be employed in combination with say soaps of lime, soda, lead or other heavy metals or a small excess of acids. Difficultly soluble esters may be admixed with more soluble esters or oils. The acids used for the production of the esters are preferably those containing carbon, hydrogen, and oxygen only, and of these, saturated fatty acids such as acetic, propionic, butyric and like acids up through caproic, caprylic and heavier acids such as stearic acid are preferred. Oleic acid, naphthenic acids, aromatic acids such as benzoic, salicylic and phthalic acids, hydroxylated acids such as lactic or tartaric acid, nitro- and amino-aromatic acids are also specified. Acids produced by oxidation of paraffin wax or oil between about 212 DEG and 320 DEG F. with air or oxygen or other agents such as nitric acid, with or without catalysts, are of especial value As the alcoholic constituent of the esters, aliphatic alcohols such as methyl, ethyl, propyl, isopropyl, butyl or secondary butyl alcohol, or the amyl alcohols are preferred, but the glycols or glycerol may also be used. Examples relate to the use of the following esters:--isopropyl ester of the acids produced by oxidation of paraffin wax (2 per cent) (4 per cent), methyl caprylate (1.5 per cent), amyl butyrate (0.5 per cent), glycol stearate (1 per cent), secondary butyl naphthenate (1.5 per cent), isopropyl benzoate (2 per cent), phenyl acetate (1%), glyceryl oleate (4 per cent), isopropyl oleate (2 per cent), ethyl stearate (2 per cent). The characteristics of the present oils are compared with those of oils containing soaps, fatty acids, fats, fatty oils, carbon tetrachloride or a sulphur compound obtained by cooking sulphur with paraffin wax. Specification 297,201, [Class 91, Oils &c.], is referred to.