Patent GB-586841-A (GB)
Title: Improvements in and relating to the inhibition of oxidation in hydrocarbon oils
IPC: C10M135/30
Filed: 1943-09-27
Abstract: Oxidation and deterioration of hydrocarbon oils is inhibited by incorporating therein a small quantity of a reaction product of sulphur with a compound containing the structural group ArXMT where Ar is an aromatic nucleus, X is a non-metal of Group 6 of the Periodic Table, M is calcium, barium, strontium, zinc or magnesium, and T is OH or (OM)nXAr where n is O, 1 or 2.  The aromatic nucleus may be benzene, biphenyl, naphthalene or anthracene, and may contain substituents such as alkyl, aryl, carboxyl, hydroxyl, alkoxy or sulphhydryl groups, metal-substituted carboxyl, hydroxyl or sulphhydryl groups, or halogen atoms.  Preferably the compound to be reacted with sulphur contains the structural group RArXMT where R represents at least one alkyl radicle joined to the aromatic nucleus Ar, the sum total of carbon atoms in such radicles being at least 5 and T in this case being OH or (OM)nXArR.  Specific compounds suitable for reaction with sulphur are barium tert.-octyl phenate, barium di-(tert.-octyl) phenate, calcium tert.-octyl phenate, barium di-(tert.-amyl) phenate, barium cetyl phenate, zinc isohexadecyl phenate, calcium salt of petroleum phenols, barium salt of wax-alkylated phenol, magnesium salt of octadecyl cresol, barium salt of phenol alkylated with refinery olefin polymers, metal phenate salts of alkylated aromatic hydroxy carboxylic acids and their carboxylate salts such as the barium phenate-zinc carboxylate of lauryl salicylic acid and metal salts of phenol sulphides or alkylated phenol sulphides, where the sulphur acts as a link between two or more of the structural groups, as in the case of the barium salt of tert.-octyl phenol sulphide.  Where the compound to be reacted with sulphur is formed by reacting an alkylated phenol with a metal oxide or hydroxide, both reactions may be carried out simultaneously by reacting the alkylated phenol with a metal oxide or hydroxide and sulphur.  The sulphurizing reaction may be carried out in presence of an aliphatic alcohol having from 8 to 20 carbon atoms per molecule, such as lauryl, cetyl, stearyl or woolfat alcohol, or of an unsaturated alcohol or of olefinic material such as tetraisobutylene or lower aliphatic olefins.  The hydrocarbon oils may be mineral lubricating oils including hydrogenated or white oils, synthetic oils prepared for example by the polymerization of olefins or by the reaction of oxides of carbon with hydrogen or by the hydrogenation of coal or its products, cracking coil tar fractions or shale oil distillates.  Hydrocarbon oil compositions mentioned are crankcase lubricants, extreme pressure lubricants, engine flushing oils, process oils, industrial oils, general machinery oils, greases, rust preventive compositions, motor fuels particularly those containing tetraethyl lead or other anti-knock agents, Diesel fuels and kerosene.  The hydrocarbon oil compositions may contain additional ingredients such as dyes, pour depressors, heat-thickened fatty oils, sulphurized fatty oils, organo-metallic compounds, metallic or other soaps, sludge dispersers, anti-oxidants, thickeners, viscosity index improvers, oiliness agents, resins, rubber, olefin polymers, voltolized fats, voltolized mineral oils, voltolized waxes, colloidal solids such as graphite or zinc oxide, and solvents and assisting agents such as esters, ketones, alcohols, aldehydes, or halogenated or nitrated compounds.  Specific alcohols mentioned are octyl, lauryl, cetyl, heytadecyl, stearyl, oleyl, phenyloctyl, or octadecylbenzyl alcohols, naphthenic alcohols, alcohols from woolfat or sperm oil and alcohols prepared by the oxidation of petroleum hydrocarbons such as paraffin wax or petrolatum. Woolfat or sperm oils may be used instead of the alcohols obtained from them.  In the case of lubricating oil compositions, additional ingredients of the detergent type such as metal soaps, metal phenates, metal alcoholates, metal phenol sulphides, metal organo-phosphates, -thiophosphates, -phosphites, or -thiophosphites, metal sulphonates, metal thiocarbamates, metal xanthates or metal thioxanthates may be present.  Specific detergents mentioned are barium tert.-octyl phenol sulphide, cobalt tert. -amyl phenol sulphide, calcium mahogany sulphonate, tin salt of wax alkylated phenol sulphide, strontium mahogany sulphonate, magnesium cetyl phenate, nickel oleate, aluminium -calcium mixed soap of fatty acid from oxidation of petroleum fractions, calcium isohexadecyl phenol sulphonate, barium octadecylate, calcium dichlorostearate, nickel amyl xanthate, calcium phenyl stearate, nickel dibutyl dithiocarbamate, barium dioctyl dithiophosphate, zinc methyl cyclohexyl dithiophosphate, calcium dihexadecyl monothiophosphite, calcium cetyl phosphate, barium mahogany sulphonates, zinc diisopropyl salicylate, aluminium naphthenate, magnesium mahogany sulphonates, di-calcium salt of octadecyl phenol sulphonic acid in which calcium replaces both the phenolic and the acid hydrogen, barium phenate-zinc sulphonate of isohexadecyl phenol sulphonic acid, barium di-tert. -amyl phenol sulphide, calcium phenate -barium carboxylate of octadecyl salicyclic acid and tin naphthenate. Mineral lubricating oil compositions are described which contain, in addition to the sulphurized compound, calcium, barium or zinc mahogany sulphonate.  In the examples, (a) sulphurized calcium or barium p-tert.-octyl phenate and stearyl alcohol with or without carbon black, (b) sulphurized barium 2, 4 ditert.-amyl phenate and stearyl alcohol and (c) sulphurized barium phenate of alkyl phenol obtained by alkylating ordinary phenol with butene polymers, are incorporated in mineral lubricating oil.  For comparison purposes mineral lubricating oil compositions containing (i) the unsulphurized barium phenate of (c) or (ii) barium tert.-octyl phenol sulphide and barium tert.-octyl phenol disulphide are described.  The Specification as open to inspection under Sect. 91 refers to the reaction products of sulphur with compounds in which M of the structural group is tin, lead, cobalt or nickel.  It is stated that the reaction with sulphur may be applied to other organic compounds containing the -OM group such as the metal alcoholates, e.g., calcium octadecylate or the barium salts of wax alcohols, or metal ketonates to form compositions useful as lubricating oil additives.  The addition of the sulphurized compounds to lubricating oils comprising animal, vegetable or fish oils or their hydrogenated or voltolized products, either alone or in admixture with mineral oils, is described.  This subject-matter does not appear in the Specification as accepted.ALSO:Anti-oxidants for adding to hydrocarbon oils are prepared by reacting sulphur with a compound containing the structural group ArXMT where Ar is an aromatic nucleus, X is a nonmetal of Group 6 of the Periodic Table, M is calcium, barium, strontium, magnesium or zinc, and T is OH or (OM)nXAr where n is 0.1 or 2.  The aromatic nucleus may be benzene, biphenyl, naphthalene or anthracene and may contain substituents such as alkyl, aryl, carboxyl, hydroxyl, alkoxy or sulphhydryl groups, metal-substituted carboxyl, hydroxyl or sulphhydryl groups, or halogen atoms. Preferably the compound to be reacted with sulphur contains the structural group RAr XMT where R represents at least one alkyl radicle joined to the aromatic nucleus Ar, the sum total of carbon atoms in such radicles being at least 5 and T in this case being OH or (OM)nXArR.  Specific compounds suitable for reaction with sulphur are barium tert.-octyl phenate, barium di-(tert-octyl)-phenate, calcium tert.-octyl phenate, barium di-(tert.-amyl)-phenate, barium cetyl phenate, zinc isohexadecyl phenate, calcium salt of petroleum phenols, barium salt of wax-alkylated phenol, magnesium salt of octadecyl cresol, barium salt of phenol alkylated with refinery olefin polymers, metal phenates of alkylated aromatic hydroxy carboxylic acids and their carboxylate salts such as the barium phenate-zinc carboxylate of lauryl salicylic acid and metal salts of phenol sulphides or alkylated phenol sulphides, where the sulphur acts as a link between two or more of the structural groups, as in the case of the barium salt of tert.-octyl phenol sulphide.  Suitable alkylated phenols, whose metal salts may be reacted with sulphur, may be prepared by alkylating phenol, cresol, naphthol or other phenolic compounds with such alkylating agents as alcohols, alkyl halides, alkyl phosphates or olefins, with the aid of catalysts such as aluminium chloride, boron fluoride and other metal halides, hydrochloric acid, hydrofluoric acid, sulphuric acid, phosphoric acid or activated clay.  Suitable olefins are petroleum refinery gases, butene, amylene and olefin polymers such as di-isobutylene, triisobutylene or other isobutylene polymers or normal butene polymer.  Other suitable alkylated phenols are those prepared by condensing phenols with chlorinated paraffin wax, chlorinated petrolatum, or with a chlorinated kerosene or gas oil.  Halogenated or nitrated phenols or naturally occuring phenols such as those obtained by alkaline extraction of certain petroleum stocks or those obtained from cashew nut shell liquid or from other vegetable sources, may also be employed.  The phenols may be converted to their metal salts by direct reaction with the oxide, hydroxide or alcoholate of the desired metal or the sodium or potassium salts may first be formed by reaction with sodium or potassium hydroxide and those salts converted to the desired divalent metal salts by double decomposition.  Where the compound to be reacted with sulphur is formed by reacting an alkylated phenol with a metal oxide or hydroxide, both reactions may be carried out simultaneously by reacting the alkylated phenol with a metal oxide or hydroxide and sulphur.  The sulphurizing reaction may be carried out in presence of an aliphatic alcohol having from 8 to