Abstract: A mixed zinc/copper dihydrocarbyl dithiophosphate, e.g. of zinc diethyl-hexyl dithiophosphate and cuprous diethyl-hexyl dithiophosphate, is prepared by reacting a dihydrocarbyl dithiophosphoric acid (DDPA) with a mixture of a basic zinc compound eg ZnO, and a basic copper compound eg Cu.sub.2 O, preferably in the presence of a promoter, eg zinc acetate. The product is a good antioxidant for use in lubricating oils.

Abstract: Dithiophosphoric acids are advantageously produced by reaction of an alcohol or phenol with phosphorus sesquisulphide in the presence of sulphur, preferably at the reflux temperature of the alcohol used.

Abstract: Crankcase lubricant compositions for use in automobile or truck engines comprise a major amount of a lubricating oil, added copper present in oil-soluble form and an oil-soluble diamine sulphide. The specified additives provide a highly effective antioxidant system, which may be used, for example, in lubricating oils which are substantially free of phosphorus.

Abstract: Substituted para-phenylene diamines have been found to be effective antioxidants capable of protecting crankcase lubricating oils from thickening and sludge formation after prolonged exposure to oxygen at elevated temperature.

Abstract: Certain novel dithiophosphonate derivatives, particularly monoesters, may be prepared inexpensively from hindered phenol compounds and are useful as anti-oxidants for example in lubricants and/or polymer materials.

Abstract: Metal dithiophosphates obtainable by reacting a basic zinc or copper compound or a molybdenum compound with a dithiophosphoric acid, said dithiophosphoric acid being obtainable by reacting phosphorus pentasulphide with a mixture of alcohols ROH and R.sup.1 (OH).sub.m where m is 1 or 2, the group R is an aliphatic hydrogen- and carbon-containing group having at least 4 carbon atoms, e.g. a C.sub.4 to C.sub.10 alkyl group, or is an alkaryl group, R.sup.1 is a hydrogen- and carbon-containing group containing at least 12 carbon atoms and either (a) a ##STR1## group or (b) the group--(C.sub.n H.sub.2n-p R.sub.p.sup.2 O).sub.q --, R.sup.2 being an alkyl group, n begin an integer of from 2 to 5, p being zero or an integer of from 1 to 5 and q being an integer of 2 or more or R.sup.1 (OH.sub.m is a glyceryl derivative having the formula ##STR2## where R.sup.3 is an aliphatic hydrogen- and carbon-containing group containing at least 9 carbon atoms and R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are hydrogen or alkyl groups.

Abstract: Certain novel heavy metal salts of dithiophosphonate derivatives, particularly monoesters, may be prepared inexpensively from hindered phenol compounds and are useful as anti-oxidants for example in lubricants and/or polymer materials.

Abstract: A lubricating oil composition having improved properties comprises a major proportion by weight of a lubricating oil, a dispersant compound, from 0.01 to 0.5 wt % phosphorus and zinc and 5 to 500 parts per million of copper, and additive concentrates for blending with oil to produce such lubricating oil compositions.

Abstract: Sulphur-containing borate esters for use in lubricants appropriate to modern oil requirements with reduced or zero amounts of phosphorous and without the need for large amounts and/or expensive forms of antioxidant and additional anti-wear additives are of the formula: ##STR1## wherein each R is a hydrocarbyl group optionally substituted by one or more --XR" group, or the two R groups attached to one boron represent a group --(R'CH).sub.m --, x is 1 or 2, each n is from 1 to 6, each m is from 2 to 4 and each R' is hydrogen, and --XR" group, or a hydrocarbyl radical optionally substituted by one or more --XR" group, X is O, S or NR" and R" is hydrogen, a hydrocarbyl radical or a hydrocarbylcarbonyl group.

Abstract: Lubricating oil containing a sulfurized dihydroxy benzene of formula ##STR1## WHERE N IS 1 TO 4, M IS 1 TO 3 AND R is an alkyl group containing at least 7 carbon atoms. These compounds impart anti-rust and anti-oxidancy to the oil with reduced copper corrosion.

Abstract: Azole aminopolysulfides and azine aminopolysulfides are effective as ashless antiwear agents for lubricating oils, particularly when used in combination with an ashless dispersant.