Exxon Chemical Patents, Inc.

Terence Colclough

Stanley J Brois

Jacob Joseph Habeeb

Morton Beltzer

Philip Skinner

Andrew James Ritchie

Paul Thomas Wood

John Derek Woollins

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.

Dihydrocarbyl dithiophosphates

Process for the preparation of dithiophosphoric acids

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.

Lubricating compositions

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.

Lubricating oil compositions and additives for use therein

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.

Dithiophosphonates, their preparation and use as anti-oxidants

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. Preferred is the zinc dithiophosphate derived from 2-ethyl hexanol (ROH) and ##STR3##

Dithiophosphates

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.

Heavy metal salts of dithiophosphonate compounds

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.

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Abingdon, United Kingdom

Terence Colclough