GB935662A - Improvements in or relating to the production of phosphorus and sulphur-containing lubricant additives - Google Patents

Abstract

A lubricant composition comprises a lubricating oil and an p additive obtained by partially neutralizing a phosphorus sulphide-hydrocarbon reaction product with 0,1 to 4,0 moles of an inorganic basic zinc compound per mole of phosphorus in said reaction product in the presence of 0,1 to 5,0 moles of boric acid (which may be formed in situ) per mole of phosphorus in said reaction product and reacting the resulting partially neutralized product with at least 0,05 mole of an inorganic basic alkali metal or alkaline earth metal compound per mole of phosphorus in said reaction product at 120 DEG to 400 DEG F. in the presence of an aliphatic alcohol-containing solvent (which may also contain water), the aliphatic alcohol having a boiling point below 350 DEG F. (see Groups IV(a) and IV(b)). The partial neutralization is preferably carried out in the presence of 0,03 to 1,5 moles of a petroleum sulphonic acid and/or in the presence of 0,1 to 10,0 moles of a polymerized unsaturated fatty acid per mole of phosphorus in the phosphosulphurized product. The aliphatic alcohol-containing solvent may be present during both the partial neutralization with the zinc compound and the subsequent reaction with the basic alkali metal or alkaline earth metal compound and the alcohol is preferably a saturated C1-C7 aliphatic alcohol, especially methanol. The lubricating oil component of the lubricant composition may be a mineral lubricating oil or a synthetic oil such as a synthetic hydrocarbon obtained by the polymerization of olefines or an alkylene oxide or polycarboxylic acid ester type synthetic lubricant. Other conventional additives may also be present, e.g. zinc dialkyl dithiophosphate, and polyisobutylene. The hydrocarbon used in the reaction with the phosphorus sulphide (e.g. P2S5, P2S3, P4S3 or P4S7) is suitably a high boiling hydrocarbon, especially a mono-olefine polymer, an essentially paraffinic hydrocarbon, an aromatic hydrocarbon alkylated by a paraffinic hydrocarbon group, or an olefine having at least 20 carbon atoms in the molecule of which 13 to 18 carbon atoms are in a long chain. The petroleum sulphonic acid which may be present in the partial neutralization step, is a preferentially oil-soluble mahogany acid and the 'sour oil' obtained by sulphonation of an aromaticcontaining lubricating oil fraction without further extraction is suitable. The polymerized unsaturated fatty acid is preferably a polymerization product of linoleic acid having a molecular weight of 300 to 2000. Various compounds of sodium, potasium, lithium, calcium, strontium and barium are specified for use as basic alkali metal or alkaline earth metal compounds.ALSO:A lubricating oil additive is obtained by partially neutralizing a phosphorus sulphide-hydrocarbon reaction product, preferably a phosphorus sulphide-monoolefin polymer reaction product, with 0,1 to 4,0 moles of an inorganic basic zinc compound per mole of phosphorus in said reaction product in the presence of 0,1 to 5,0 moles of boric acid (which may be formed in situ, e.g. from boric acid anhydride or a boric acid ester) per mole of phosphorus in said reaction product, and reacting the resulting partially neutralized product with at least 0,05 mole of an inorganic basic alkali metal or alkaline earth metal compound per mole of phosphorus in said reaction product at 120 DEG to 400 DEG F. in the presence of an aliphatic alcohol-containing solvent; the aliphatic alcohol having a boiling point below 350 DEG F. The partial neutralization is preferably carried out in the presence of 0,03 to 1,5 moles of a petroleum sulphonic acid and/or in the presence of 0,1 to 10,0 moles of a polymerized unsaturated fatty acid per mole of phosphorus in the phosphosulphurized product. The aliphatic alcohol-containing solvent may contain water and may be present during both the partial neutralization step with the zinc compound and during the further reaction with the basic alkali metal or alkaline earth metal compound. Specified basic zinc compounds are the oxide, carbonate and sulphide and specified alkali metal and alkaline earth metal compounds include sodium bicarbonate, hydroxide, and sulphide, potassium and lithium hydroxides, potassium carbonate, strontium oxide, and calcium or barium oxide, hydroxide, sulphide or carbonate, the barium compounds being preferred. The phosphorus sulphide may be P2S3, P4S3 or P4S7 but is preferably P2S5 and the hydrocarbon reacted therewith is preferably a mono-olefin polymer, or a mixture of mono-olefine and iso-monoolefine polymers, having a molecular weight of 150 to 50,000, preferably 300 to 10,000. A suitable hydrocarbon is obtained by polymerizing a hydrocarbon mixture containing isobutylene, butylenes and butanes recovered from petroleum gases. The phospho-sulphurization may be carried out in the presence of a sulphurizing agent, e.g. sulphur or a halide thereof, and is preferably effected in a non-oxidizing atmosphere, e.g. of nitrogen. The petroleum sulphonic acid which may be present during the partial neutralization is a preferentially oil soluble mahogany acid and the "sour oil" obtained by sulphonation of an aromatic-containing lubricating oil fraction may be used without further extraction. The polymerized unsaturated fatty acid may be obtained by polymerizing natural or synthetic unsaturated carboxylic acids of 16 to 26 carbon atoms and the polymer may comprise monomers, dimers, trimers and higher polymers of the acids. The preferred polymerized acids are those obtained as a by-product still residue in the manufacture of sebacic acid by the dry distillation of castor oil in the presence of sodium hydroxide and the polymerization products of linoleic acid having a molecular weight of 300 to 2,000 are particularly suitable. Examples are given in which the phosphosulphurized hydrocarbon product is obtained by reacting P2S5 with a mixed butene polymer having an average molecular weight of 750 to 800 at 450 DEG F. for about 5 1/2 hours. The products may be used as additives for mineral or synthetic lubricating oils (see Group III).ALSO:A lubricant oil additive is obtained by partially neutralising a phosphorus sulphidehydrocarbon reaction product with 0,1 to 4,0 moles of an inorganic basic zinc compound per mole of phosphorus in said reaction product in the presence of 0,1 to 5,0 moles of boric acid (which may be formed in situ) per mole of phosphorus in said reaction product, and reacting the resulting partially neutralised product with at least 0,05 mole of an inorganic basic alkali metal or alkaline earth metal compound per mole of phosphorus in said reaction product at a temperature of 120 DEG F. to 400 DEG F. in the presence of an aliphatic alcohol-containing solvent, the aliphatic alcohol having a boiling point below 350 DEG F. The partial neutralisation is preferably carried out in the presence of 0,03 to 1,5 moles of a petroleum sulphonic acid and/or in the presence of 0,1 to 10,0 moles of a polymerisation product of an unsaturated fatty acid per mole of phosphorus in the phosphorus sulphidehydrocarbon reaction product. The aliphatic alcohol-containing solvent may be any aliphatic alcohol boiling below 350 DEG F. or a mixture of such an alcohol with water. The alcohol is preferably a saturated C1-C7 aliphatic alcohol, especially methanol, and water may be present in an amount up to 2,0 moles per mole of basic alkali metal or alkaline earth metal compound. The solvent may be used both during the partial neutralisation with the basic zinc compound and during the further reaction with the basic alkali metal or alkaline earth metal compound. Specified basic zinc compounds are the oxide, carbonate and sulphide and specified alkali metal and alkaline earth metal compounds include sodium carbonate, bicarbonate, hyddroxide and sulphide, potassium carbonate and hydroxide, lithium hydroxide, calcium oxide, hydroxide, carbonate and sulphide, strontium oxide and barium oxide, hydroxide, sulphide and carbonate, the barium compounds being preferred. The phosphorus sulphide-hydrocarbon reaction product may be prepared by reacting a normally liquid hydrocarbon with a phosphorus sulphide, e.g. P2S3, P4S3 or P4S7 or preferably P2S5. The normally liquid hydrocarbon is suitably a high boiling hydrocarbon especially a mono-olefine polymer (see Group IV(a)) but essentially paraffinic hydrocarbons may also be used, e.g. bright stock residuums, lubricating oil distillates, petroleums or paraffin waxes. There may also be used condensation products of any of the latter hydrocarbons, usually through first halogenating the hydrocarbons, with aromatic hydrocarbons, in the presence of anhydrous inorganic halides, e.g. aluminium chloride, zinc chloride or boron fluoride. Olefines having at least 20 carbon atoms in the molecule of which 13 to 18 carbon atoms are in a long chain may also be used. The phosphosulphation reaction can be carried out in the presence of a sulphurising agent, e.g. sulphur or a halide of sulphur and is preferably effected in a nonoxidising atmosphere, e.g. of nitrogen. The boric acid can be added as such or may be formed in situ by adding boric acid anhydride or a boric acid ester which is capable of decomposition, e.g. on heating, to form boric acid in the reaction mixture. The petroleum sulphonic acid which may be present is a preferentially oil soluble "mahogany acid" and the "sour oil" obtained by sulphonation of an aromatic-containing lubricating oil fraction may be used directly without further extraction. The polymerised products of the unsaturated fatty acid may suitably be those obtained by polymerising natural or synthetic unsaturated carboxylic acids of 16 to 26 carbon atoms, and the polymeric products may comprise monomers, dimers, trimers and higher polymers of the acids. Suitable acids to form the polymerised products may be obtained by hydrolysis