Patent GB-936650-A (GB)
Title: Phosphosulphurization products useful as lubricant additives and processes for the production thereof
IPC: C10M159/12
Filed: 1959-09-04
Abstract: A lubricant composition comprises a lubricating oil containing a minor proportion by weight of a complex obtained by reacting a phosphorus sulphide, especially phosphorus pentasulphide, with a hydrocarbon and neutralizing the reaction product with a basic alkaline earth metal compound in the presence of water, a water-soluble monohydroxy compound selected from alkanols and mixtures of an alkanol and a phenol, such water, alkanol, or phenol not being present in the final composition, and a dialkyldithiophosphorus compound having the general formula <FORM:0936650/III/1> in which R1 and R2 are C1 to C10 alkyl groups, X is hydrogen or a metal, e.g. zinc, and n is the valency of X (see Groups IV(a) and IV(b)).  The phosphorus sulphide-hydrocarbon reaction product may, if desired, be hydrolysed, e.g. by treating with steam, before the neutralization step.  The hydrocarbon used in the reaction is preferably a mono-olefin polymer or co-polymer, especially one derived from a mixture containing isobutylene, other butylenes and butanes recovered from petroleum gases.  Other suitable hydrocarbons are essentially paraffinic hydrocarbons, alkylated aromatic hydrocarbons, and olefins having at least 20 carbon atoms in the molecule of which from 13 to 18 carbon atoms are in a long chain. Suitable monohydroxy compounds for use in the neutralization step are C1-C3 alkanols and suitable phenols for use in admixture with such alkanols are phenol and amyl-, octyl-, nonyl-, and dodecyl phenols, a mixture of methanol and nonyl phenol being preferred.  The basic alkaline earth metal compound is suitably the oxide, hydroxide, carbonate or sulphide of Ca, Ba, Sr or Mg. The dialkyldithiophosphorus compound may be formed in situ by adding a decomposable ester such as a tertiary alcohol ester (e.g. t-butyl ester) of the dialkyldithiophosphoric acid which decomposes on mild heating to form the free acid.  The lubricating oil base of the lubricant composition may be a mineral oil or a synthetic oil, e.g. an oil obtained by the polymerization of olefines, an alkylene oxide type oil or a polycarboxylic acid ester type oil e.g. diester oils. Other conventional additives may also be present.  Specification 774,779 is referred to.ALSO:An oil-soluble neutralized complex suitable for use as a lubricant additive is obtained by reacting a phosphorus sulphide with a hydrocarbon, preferably a monoolefin polymer, and neutralizing the reaction product with a basic alkaline earth metal compound in the presence of water, a water-soluble monohydroxy compound selected from alkanols and mixtures of an alkanol and a phenol, and a dialkyl dithiophosphorus compound having the general formula:  <FORM:0936650/IV(a)/1> in which R1 and R2 are each alkyl groups having 1 to 10 carbon atoms, X is hydrogen or a metal, e.g. zinc, and n is the valency of X.  The phosphorus sulphide-hydrocarbon reaction product may, if desired, be hydrolysed before neutralization, the hydrolysis being suitably effected at from 200 DEG  to 500 DEG F., e.g. by introducing steam through the reaction mass.  The hydrocarbon is preferably a mono-olefin polymer or a mixture of mono-olefin polymers and iso-monoolefin polymers having molecular weights of from 150 to 50,000 or more, preferably from 300 to 10,000, a polymer obtained from a hydrocarbon mixture containing isobutylene, other butylenes and butanes recovered from petroleum gases being particularly suitable.  The phosphorus sulphide is preferably P2S5 but P2S3, P4S3 or P4S7 may also be used.  The phosphosulphurization reaction is preferably carried out in a non-oxidizing atmosphere, e.g. of nitrogen, at from 300 DEG  to 500 DEG F. and if desired a sulphurizing agent, e.g. sulphur or a sulphur halide, may be present during the reaction.  When the product is hydrolysed it may be substantially freed from the inorganic phosphorus acids present before the subsequent neutralization stage by contacting with an absorbent material at 100 DEG  to 500 DEG F. or by extraction with phenol or a C1-C5 alkanol in admixture with water. The neutralization of the hydrolysed or unhydrolysed phosphosulphurization product with the basic alkaline earth compound in the presence of the dialkyl dithiophosphorus compound, water and the monohydroxy compound is usually carried out at the reflux temperature of the monohydroxy compound for 1 to 10 hours and the temperature is then raised to distill off water and the hydroxy compound.  The dialkyl dithiophosphorus compound may be formed in situ by adding a decomposable ester such as a tertiary alcohol (especially tertiary butyl alcohol) ester of the dialkyl dithiophosphoric acid which decomposes on mild heating to form the free acid.  The basic alkaline earth metal compound is suitably the oxide, hydroxide, carbonate, or sulphide of Ca, Ba, Sr or Mg, barium oxide being preferred.  The water-soluble monohydroxy compound is suitably methanol, ethanol, propanol or isopropanol, and suitable phenols for use in conjunction with the alkanols are phenol itself and amyl-, octyl-, nonyl-, and dodecyl phenols, a mixture of methanol and nonyl phenol being preferred.  The products have a high ratio of alkaline earth metal to detergent phosphorus and are useful as additives for mineral or synthetic lubricating oils (see Group III). Specification 774,779 is referred to.ALSO:An oil-soluble neutralised complex suitable for use as a lubricant additive is obtained by reacting a phosphorus sulphide with a hydrocarbon and neutralising the reaction product with a basic alkaline earth metal compound in the presence of water, a watersoluble monohydroxy compound selected from alkanols and mixtures of an alkanol and a phenol, and a dialkyl dithiophosphorus compound having the general formula:- <FORM:0936650/IV(a)/1> wherein R1 and R2 are C1 to C10 alky groups, X is hydrogen or a metal, e.g. zinc, and n is the valency of X.  The phosphorus sulphidehydrocarbon reaction product may, if desired, be hydrolysed before neutralisation.  The hydrocarbon reacted with the phosphorus sulphide is suitably a high-boiling hydrocarbon especially a mono-olefine polymer or copolymer (see Group IV(a)) or it may be an essentially paraffinic hydrocarbon such as a bright stock residuum, lubricating oil distillate, petrolatum or paraffin wax, an alkylated aromatic hydrocarbon in which the alkyl group is derived from the above specified paraffinic hydrocarbons, or an olefin having at least 20 carbon atoms in the molecule of which from 13 to 18 carbon atoms are in a long chain.  The phosphorus sulphide is preferably P2S5 but P2S3, P4S3 or P4S7 may also be used.  The phosphosulphurisation reaction is preferably carried out in a non-oxidising atmosphere, e.g. of nitrogen, at from 300 to 500 DEG F. and if desired a sulphurising agent, e.g. sulphur or a halide of sulphur may be present during the reaction.  When it is desired to hydrolyse the phosphosulphurised product the hydrolysis may be suitably effected at from 200 DEG  to 500 DEG F., e.g. by introducing steam through the reaction mass and the hydrolysed product may if desired be substantially freed from the inorganic phosphorus acids present before the subsequent neutralisation stage by contacting with an adsorbent material at 100 DEG  to 500 DEG F. or by extraction with phenol or a C1-C5 alkanol in admixture with water.  The neutralisation of the hydrolysed or unhydrolysed phosphosulphurisation product with the basic alkaline earth compound in the presence of the dialkyl dithiophosphorus compound, water and the monohydroxy compound is usually carried out at the reflux temperature of the monohydroxy compound, normally corresponding to from about 155 DEG  to 185 DEG F. at atmospheric pressure, and is preferably effected in the presence of a hydrocarbon diluent, e.g. a lubricating oil.  The reaction mixture may be heated at the reflux temperature for from 1 to 10 hours and the temperature may then be raised to about 200 to 400 DEG F. at atmospheric pressure to distill off water and the hydroxy compound.  The dialkyl dithiophosphorus compound may be formed in situ by adding a decomposable ester such as a tertiary alcohol ester (especially the t. butyl ester) of the dialkyl dithiophosphoric acid which decomposes on mild heating to form the free dialkyl dithiophosphoric acid.  The basic alkaline earth compound is suitably the oxide, hydroxide, carbonate, or sulphide of Ca, Ba, Sr, or Mg, barium oxide being preferred.  The water-soluble monohydroxy compound may suitably be methanol, ethanol, propanol or isopropanol and suitable phenols for use in admixture with the alkanol are phenol itself and amyl-, octyl-, nonyl-, and dodecyl phenols.  A mixture of methanol and nonyl phenol is preferred.  The products have a high ratio of alkaline earth metal to detergent phosphorus and are useful as additives for mineral or synthetic lubricating oils (see Group III). Specification 774,779 is referred to.