Patent GB-767115-A (GB)
Title: Manufacture of metal salts of phenolic compounds containing sulphur
Inventor: RAE NORMAN SIDNEY
Filed: 1954-02-04
Abstract: Metal salts of sulphurized phenols are prepared by reacting a sulphurized phenol with a portion of a metal base to produce a first product, sulphurizing the first product and then reacting the sulphurization mixture with a further portion of the metal base at an elevated temperature.  Sulphurized phenols mentioned are alkyl phenol sulphides such as tert.-octyl phenol sulphide and sulphurized cresols, xylenols and compounds of the formula Ar(OH)n where n is 1, 2 or 3 and Ar is an aromatic ring such as benzene or naphthalene which may be further substituted by alkyl, cycloalkyl, alkaryl, aralkyl, amino, or acyl groups.  Sulphurized mixtures of phenols such as sulphurized crude petroleum phenols, or sulphurized tri-cresol (a mixture of o-, m- and p-cresol) which may have been further alkylated, may be used.  Metal bases mentioned are oxides, hydroxides, sulphides, carbides, hydrides and alkoxides of alkaline-earth metals such as calcium and barium. Metal salts also referred to are those of the alkali-metals, tin, lead, chromium, iron, nickel and cobalt.  The initial reaction of the sulphurized phenol with the metal base is conducted so that the first product contains less than the amount of metal required in the final salt, the reaction mixture is then treated with a sulphurizing agent after which the remainder of the metal base required to bring the metal content of the salt up to the desired proportion is added.  The reaction with metal base is carried out at temperatures from 100 DEG to 160 DEG  C. and the sulphurization is conducted at from 50 DEG  to 250 DEG  C.  Sulphurization agents specified are sulphur and sulphur halides.  Reaction solvents may be basic if the phenolic material is only weakly acidic, or neutral and inert such as paraffinic or halogenated hydrocarbons, petroleum ether, naphtha fractions, gas oil fractions or lubricating oil distillates.  Anti-foaming and solubilizing agents comprising aliphatic nitriles or higher aliphatic alcohols may be present during the reaction.  On completion of the reaction the reaction mixture is filtered to give a solution of the product.  The product may be further treated with a phosphorizing agent such as red phosphorus or phosphorus sulphides at 100 DEG  to 200 DEG  C. Treatment of concentrates of metal salts of sulphurized phenols to reduce their water-sensitivity as described in Specifications 600,825 and 599,279, [Group IV].  The products are used as additives for lubricating oils and liquid fuels (see Group III). In examples, tert.-octyl phenol sulphide is heated with barium oxide in a mineral lubricating oil solvent, the temperature is raised and sulphur is added and the reaction is then completed by adding the remaining barium oxide at the original temperature. The Provisional Specification also refers to the use of sulphurized phenols derived from compounds of the formula Ar(OH)n, where n is 1, 2 or 3 and Ar is a heterocyclic ring such as thiophene or pyridine which may be substituted by alkyl, cycloalkyl, alkaryl, aralkyl, amino, acyl or sulphonic groups and to compounds where Ar is aromatic such as benzene and naphthalene and is substituted by sulphonic groups.ALSO:Additives for use in lubricating oils and in liquid fuels comprise metal salts of sulphurized phenols prepared by reacting a sulphurized phenol with a portion of metal base to produce a first product, sulphurizing this first product and then reacting the sulphurization mixture at an elevated temperature with a further portion of metal base.  Metal salts specified are those of alkaline-earth metals such as calcium and barium.  Other metals mentioned are alkali-metals, tin, lead, chromium, iron, nickel and cobalt.  Sulphurized phenols specified are alkyl phenol sulphide such as tert.-octyl phenol sulphide and sulphurized cresols, xylenols and compounds of the formula Ar(OH)n where n is 1, 2 or 3 and Ar is an aromatic nucleus such as benzene or naphthalene which may be substituted by alkyl, cycloalkyl, alkaryl, aralkyl, amino or acyl groups, sulphurized petroleum phenols, and sulphurized tri-cresol (a mixture of o-, m- and p-cresol) which may be further alkylated.  The product is obtained as a concentrate of the metal salt in the reaction solvent used which may be a paraffinic or halogenated hydrocarbon, petroleum ether, a naphtha fraction, a gas oil fraction or a lubricating oil distillate.  A lubricating oil concentrate may contain 10-50 per cent by weight of the metal salt and be blended with lubricating oil base stock to give a finished blend containing 0.05 to 25 per cent of the metal salt.  Examples illustrate the preparation of a 40 per cent concentrate of barium tert.-octyl phenol sulphide in a mineral lubricating oil.  It is stated that the products of the invention may be further treated with phosphorization agents such as red phosphorus or phosphorus halides.  The compositions containing the products may also contain dyes, pour point depressors, heat thickened fatty oils, organo-metallic compounds, metallic soaps, sludge dispersers, anti-oxidants, thickeners, viscosity index improvers, oiliness agents, resins, rubber, olefin polymers, voltolized fats, voltolized mineral oils, voltolized waxes, graphite, zinc oxide, solvents and assisting agents such as esters, ketones, aldehydes, alcohols, and halogenated or nitrated compounds.  The products are also used in extreme pressure lubricants, engine flushing oils, industrial oils, general machinery oils, greases, rust preventive compositions, motor fuels, diesel oils and kerosene.  The Provisional Specification also refers to metal salts of sulphurized phenols derived from phenols of the formula Ar(OM)n where n is 1, 2 or 3 and Ar is a heterocyclic ring such as thiophene or pyridine which may be substituted by alkyl, cycloalkyl, alkaryl, aralkyl, amino acyl or sulphonic groups and to compounds where Ar is aromatic such as benzene or naphthalene and is substituted by sulphonic groups.  Specifications 599,279 and 600,825 are referred to.