Patent GB-748137-A (GB)
Title: Improvements in or relating to lubricating oil compositions
IPC: C10L1/26
Filed: 1953-03-12
Abstract: An additive for lubricating oils or other hydrocarbon products, e.g. motor fuels (see Group III) comprises an ester having the formula R1CH(OH)P(O)(R2)(R2) wherein R1 is hydrogen or a C1 to C12 hydrocarbon radical and R2 is a hydroxyl radical, a C1 to C30 alcohol residue, a sulphur-containing alcohol residue containing up to 30 carbon atoms, a C1 to C30 mercaptan residue, a phenol residue, an alkyl phenol residue, a thiophenol residue, an alkyl phenol sulphide residue, or a carbamic acid or thiocarbamic acid residue, at least one R2 being one of said organic groups, or (b) the product obtained by phosphosulphurizing the above ester, or (c) a polyvalent metal salt of either of the additives (a) and (b).  R1 is preferably a straight or branched chain alkyl group, e.g. methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, n-hexyl, isooctyl, 2-ethylhexyl, decyl, and dodecyl. It may also be a cycloalkyl, aralkyl, aryl or alkaryl radical, e.g. methylcyclohexyl, ethyl cyclohexyl, phenylethyl, phenyl propyl, phenyl, cresyl, or tert-butyl phenyl.  The hydrocarbon group in the alcohol residue R2 may be one of the above specified groups but should preferably contain 12 to 24 carbon atoms.  Thus it may be a tetradecyl, hexadecyl, octadecyl or tetracosyl radical or an alkenyl radical such as decenyl, octadecenyl, or a C6-C24 polypropenyl radical.  The additives may be obtained by condensing an aldehyde R1CHO with phosphorus trichloride and hydrolysing the resulting trichloro condensation product to form a hydroxy phosphonic acid R1CH(OH).P(O)(OH)2 which is then esterified with an alcohol or phenol.  Several alcohols and phenols are specified, including sulphurized alcohols, sulphur-containing alcohols, e.g. 2-dodecyl-thioethanol, alkyl phenols, and alkyl phenol sulphides. Products in which R2 is a mercaptan, thiophenol, carbamic acid or thiocarbamic acid residue may be obtained by reacting a phosphonic acid chloride R1CH(OH)P(O)(Cl)2 with a metal mercaptide, thiophenolate, carbamate, or thiocarbamate.  The metal salts may be prepared by treating the partial esters (containing one P-OH group) with a finely-divided metal oxide or hydroxide.  Specified metals are Group II metals, e.g. calcium. barium, magnesium, and strontium; also nickel, cobalt, tin, lead, zinc, copper, aluminium, iron, and manganese.  The neutralization to form the salt may be carried out in a lubricant base oil.  The metal may also be used in the form of metal carbide or metal alkoxide.  The phosphosulphurized products may be prepared by reacting the esters with a sulphide of phosphorus such as P2S3, P2S5, P4S3\t or P4S7 or mixtures thereof or with mixtures of elemental sulphur and elemental phosphorus.  A mixture of one or more sulphides of phosphorus and elemental sulphur and/or elemental phosphorus may also be used.  The phospho-sulphurization may be carried out in an organic solvent or in a lubricant base oil. Metal salts of the phosphosulphurized products may be obtained by a procedure similar to that described above for the preparation of the metal salts of the esters.  Examples describe the production of: (1) the partial ester of 1-hydroxy-n-butylphosphonic acid and tertiary octylphenol sulphide by reacting them together in the presence of xylene and concentrated sulphuric acid and removing the water formed; (2) the calcium salt of the product of (1) by dissolving the latter in ether and adding the solution to a suspension of calcium hydroxide in ice and water; (3) the calcium salt of the partial ester octadecenyl-1-hydroxy-n-butyl phosphonate by reacting 1-hydroxy-n-butyl-phosphonic acid, and oleyl alcohol in xylene while removing the water formed and then reacting with calcium hydroxide as in (2); (4) the calcium salt of the ester of 1-hydroxy-n-butylphosphonic acid and sulphurized oleyl alcohol by a procedure similar to that used in (3); and (5) the calcium salt of the product obtained by reacting the partial ester formed in (3) with phosphorus pentasulphide in the presence of dioxane, the calcium salt being formed by neutralizing the phospho - sulphurized product with sodium hydroxide and then adding an aqueous solution of calcium chloride.ALSO:A lubricating oil composition comprises a major proportion of a lubricating oil and a minor proportion of an additive comprising (a) an ester having the formula R1CH(OH). P(O)(R2)(R2) wherein R1 is hydrogen or a C1 to C12 hydrocarbon radical and R2 is a hydroxyl radical, a C1 to C30 alcohol residue, a sulphur-containing alcohol residue containing up to thirty carbon atoms, a C1 to C30 mercaptan residue, a phenol residue an alkyl phenol residue, a thiophenol residue, an alkyl phenol sulphide residue, or a carbamic acid or thiocarbamic acid residue, at least one R2 being one of said organic groups, or (b) the product obtained by phosphosulphurizing the above ester or (c) a polyvalent metal salt of either of the additives (a) and (b).  R1 is preferably a straight or branched chain alkyl group, e.g. methyl, ethyl, propyl, isopropyl, butyl, tert.-butyl, n-hexyl, isooctyl, 2-ethylhexyl, decyl and dodecyl. It may also be a cycloalkyl, an alkyl aryl or alkaryl radical, e.g. methylcyclohexyl, ethyl-cyclohexyl, phenylethyl, phenylpropyl, phenyl, cresyl, or tert.-butyl phenyl.  The hydrocarbon group in the alcohol residue R2 may be one of the above specified groups but should preferably contain 12 to 24 carbon atoms.  Thus it may be a tetradecyl, hexadecyl, octadecyl or tetracosyl radical or an alkenyl radical such as decenyl, octadecenyl, or a C6-C24 polypropenyl radical.  The additives may be obtained (see Group IV(b)) by condensing an aldehyde (R1CHO) with phosphorus trichloride and hydrolyzing the resulting trichloro condensation product to form a hydroxy phosphonic acid of the formula R1CH(OH). P(O)(OH)2 which is then esterified with an alcohol or phenol.  Several alcohols and phenols are specified including sulphur-containing alcohols, alkyl phenols and alkyl phenol sulphides.  Products in which R2 is a mercaptan, thiophenol, carbamic acid or thiocarbamic acid residue may be obtained by reacting a phosphoric acid chloride R1CH(OH)P(O) (Cl)2 with a metal mercaptide, thiophenolate, carbamate or thiocarbamate. The metal salts may be prepared by treating the partial esters (containing one P-OH group) with a finely divided metal oxide or hydroxide. Specified metals are Group II metals, e.g. calcium, barium, magnesium, and strontium; also nickel, cobalt, tin, lead, zinc, copper, aluminium, iron and manganese.  The metal may also be used in the form of metal carbide or metal alkoxide.  The neutralization to form the salt may be carried out in a lubricant base oil.  The phospho-sulphurized products may be prepared by reacting the esters with a sulphide of phosphorus such as P2S3, P2S5, P4S3 or P4S7 or mixtures thereof or with mixtures of elemental sulphur and elemental phosphorus.  A mixture of one or more sulphides of phosphorus and elemental sulphur and/or elemental phosphorus may also be used.  The phosphosulphurization may be carried out in an organic solvent or in a lubricant base oil. Metal salts of the phosphosulphurized products may be obtained by a procedure similar to that described above for the preparation of the metal salts of the esters.  The additives are preferably added to the lubricating oil in proportions of from 0.01 per cent to 15 per cent by weight of the total composition.  Other additives such as phenols, phenol sulphides, metal soaps, metal petroleum sulphonates, metal phenates, metal alcoholates, metal alkyl phenol sulphides, metal organo-phosphates, -phosphites,- thiophosphates and -thiophosphites, metal-xanthates, -thioxanthates, and thiocarbamates may also be present.  Other agents which may be present are dyes, pour point depressants, heat thickened fatty oils, sulphurized fatty oils, sludge dispersers, antioxidants, thickeners, viscosity index improvers, oiliness agents, resins, rubber, and olefin polymers. The lubricating oil base stock may be a straight mineral lubricating oil or distillate, a hydrogenated oil, a white oil, or a synthetic oil such as the polyether or polyester type or one prepared by the polymerization of olefins, by the reaction of oxides of carbon with hydrogen, or by the hydrogenation of coal or its products.  Mixtures of such synthetic lubricants with mineral oil lubricants may also be used and in some cases cracking coal tar fractions and coal tar or shale oil distillates may be used. The additives may also be employed in other mineral oil compositions and hydrocarbon products, e.g. in motor fuels, mineral oil base hydraulic fluids, torque converter fluids, cutting oils, flushing oils, turbine oils, transformer oils, industrial oils, gear lubricants and greases.  Examples describe the production of (1) the partial ester of 1-hydroxy-n-butylphosphonic acid and tertiary octyl phenol sulphide and its calcium salt: (2) the calcium salt of the partial ester-octadecnyl 1-hydroxy-n-butyl phosphonic acid and sulphurized oleyl alcohol; and (4) the calcium salt of the product obtained by reacting the partial ester-octadecenyl -1- hydroxy-n-butyl phosphonate with phosphorus pentasulphide. The results of a carbon slack dispersion test on a solvent extracted paraffinic base oil containing 1 per cent of the metal salt products of (1) (2) and 4 respectively and of a bearing corrosion test on a solvent extracted paraffinic lubricating oil containing 0.5 per cent of the partial ester product obtained in (1), the metal salt obtained in (1) and the product obtained in (2) respectively are given and compared with the results obtained with the base oil above.