Patent GB-690421-A (GB)
Title: Lubricating oil compositions
Filed: 1949-04-04
Abstract: Mixed carbonate esters of monohydric alcohols and polyhydric alcohols or polyhydric alcohols partially esterified with an organic acid are prepared by reacting a carbonate or chlorcarbonate of the monohydric alcohol with the polyhydric alcohol to partially or completely esterify the latter.  The polyhydric alcohol may first be partially esterified with a carboxylic acid, so yielding as final product an estercarbonate; alternatively the carbonate products which contain one or more free hydroxy groups may be subsequently esterified with the carboxylic acid.  The polyhydric alcohols may contain additional groups such as nitro, carboxylic, ester, amide, ether, pyridyl, quinolyl, phenyl, sulphonate and primary, secondary or tertiary amino groups.  In such cases, the carbonate-ester may be modified by further treatment; when hydroxy and/or amine groups are present, the carbonate may be reacted with a saturated or unsaturated monocarboxylic acid anhydride, ester or acid chloride to form an estercarbonate, as stated above, and/or an amidocarbonate, or with an alkyl halide to form an ether or alkylated amine, or with an alkyl chlorcarbonate to form a di- or tri-carbonate and/or a urethane, or with a sulphonate or sulphonyl chloride to form a partial sulphonate and/or a sulphonamide or with an aldehyde to form an acetal and/or Schiff's base, or with carbon disulphide and an alkali to form a xanthate and/or thiocarbamate which may be followed by reaction with an alkyl halide, acid chloride, chloromethyl ester, chloracetic acid ester, chlorethyl ester or an alkyl chlorocarbonate to give the corresponding xanthate and/or thiocarbamate derivative; the mixed carbonate esters containing an ethylenic linkage may be catalytically condensed with a long-chain mercaptan.  The mixed carbonates are used in lubricating oil rust-proofing compositions (see Group III).  In an example, pentaerythritol mono-oleate, obtained by reacting the alcohol and ester in equimolecular amounts, is refluxed in toluene in presence of pyridine while adding allyl chlorocarbonate thereto in equimolar quantity so yielding pentaerythritol mono-oleate mono allyl carbonate.  Other mixed carbonates mentioned are pentaerythritol di-oleate monopetroleum carboxylate mono-ethyl carbonate, pentaerythritol mono - lauryl mono - hexyl carbonate, sorbitan mono-oleate mono-allyl carbonate, glycerol mono-stearate mono-allyl carbonate, dipentaerythritol mono-oleate di-C9Oxo carbonate, pentaglycerol mono-tall oil ester mono-allyl carbonate, triethanol amine mono - stearate mono - allyl carbonate, tris-(hydroxy methyl) amino methane mono-stearate mono-allyl carbonate and tetramethylol cyclohexanol mono-oleate mono-allyl carbonate. Numerous other examples of monohydric and polyhydric alcohols and carboxylic acid reactants are mentioned including propyl, 2-ethyl butyl, "Cellosolve" (Registered Trade Mark), myristyl, linoleyl, furfuryl and tetrahydrofurfuryl alcohols, ethylene and propylene glycols, polyglycerol, anhydro-ennea-heptitol, 2 - amino - 2 - methylol - 1,3 - propanediol, benzotrimethylol, o - tert. - tri - hydroxybutyl pyridine and tris-(hydroxymethyl) nitro methane, and acetic, butyric, ricinoleic, lignoceric, naphthenic, succinic, maleic and fumaric acids and those obtained by oxidation of petroleum products or aldehydes; the fatty acids may be used in the form they occur in fatty oils.  The carbonate reactants used to form the mixed esters may be prepared by reacting phosgene with the monohydric alcohol in presence of pyridine.  Specification 576,083 is referred to.ALSO:Lubricating oil compositions having rust preventing properties comprise a mineral or synthetic lubricating oil base and a mixed carbonate ester of a monohydroxy alcohol and a polyhydric alcohol or a polyhydric alcohol partially esterified with an organic acid, the mixed ester preferably constituting from 0.01 to 10 per cent by weight of the total composition.  The monohydroxy alcohol may be a saturated or unsaturated alkyl or cycloalkyl alcohol having, e.g. from 1 to 30 carbon atoms per mole, such as ethyl, propyl, allyl, 2-ethyl-hexyl, 2-ethylbutyl, "Cellosolve" (Registered Trade Mark), C8 oxo, C9 oxo, C13 oxo, cetyl, oleyl, octadecyl, myristyl, linoleyl, erucyl and lauryl alcohols and also furfuryl, tetrahydrofurfuryl and cyclohexanol alcohols. The polyhydroxy alcohols mentioned include ethylene glycol, 1:3 propanediol, glycerol, pentaglycerol, tetramethylolpentanol and cyclohexanol, anhydroennea-heptitol, sorbitol, inositol, benzotrimethylol, sorbitan, dipentaerythritol and polyhydroxy compounds containing nitro, carboxylic, ester, amide, phenyl, ether, pyridyl, quinolyl, sulphonate and amino groups such as 2-amino-2-methylol-1 : 3-propanediol, o-tert-trihydroxybutyl pyridine, triethanolamine, methyl diethanolamine, tris (hydroxymethyl) nitro methane and 2-methyl (orethyl)-2-nitro-1:3-propanediol.  Where the polyhydroxy alcohol residue in the carbonate ester has one or more free hydroxy groups it is preferred that at least one of them should be esterified by a carboxylic acid such as an aliphatic or cycloaliphatic acid, e.g. acetic, butyric, valeric, lauric, palmitic, stearic, oleic, linoleic, ricinoleic, oleomargic, erucic, behenic, arachidic, lignoceric and naphthenic acids, acids obtained by oxidation of petroleum products or of aldehydes, acids derived from various specified vegetable oils and dicarboxylic acids such as succinic, maleic, fumaric, azelaic and sebacic acids.  In general, the mixed carbonate esters are prepared by reacting the polyhydroxy compound, patially esterified or not, with a carbonate or chlor-carbonate of the monohydroxy compound to introduce one or more carbonate linkages (see Group IV(b)).  These esters may be further treated when functional groups are present, resulting in modified properties of the product; thus free hydroxyl and amino groups in the carbonate ester may be condensed with (1) a saturated or unsaturated monocarboxylic acid anhydride, chloride or ester to form an ester carbonate and/or an amide; (2) an alkyl halide to form an ether and/or alkylated amino-carbonate; (3) an alkyl chlorocarbonate to form a di-and/or tri-carbonate and/or urethane carbonate; (4) a sulphonic acid or acid chloride to form a partial sulphonate and/or sulphonamide carbonate; (5) an aldehyde to form an acetal and/or a Schiff's base; (6) carbon disulphide and an alkali to give a xanthate and/or a thiocarbamate which substances may be further reacted with an alkyl halide, acid chloride, chloromethyl-ether, chloracetic acid ester, chloroethyl ester or an alkyl chloro carbonate to form the corresponding xanthate and/or thiocarbamate derivative, and; (7) a long chain mercaptan providing the carbonate ester contains an ethylenic linkage.  The oil bases for the compositions may be distillates or blends of petroleum, slushing oils, e.g. mixtures of naphtha and lubricating oil which may contain a small amount of petrolatum or degras, and synthetic oils, e.g. those obtained by polymerization of olefines or by hydrogenation of coal and its products. Optional ingredients in the compositions are heat-thickened fatty oils, sulphurized oils, organo-metallic compounds, metallic or other soaps, sludge dispersers, antioxidants, thickeners, viscosity index improvers, pour point depressors, oiliness agents, resins, olefine polymers, colloidal solids such as graphite or zinc oxides and solvents and solubilizers such as esters, ketones, alcohols aldehydes and halogenated and nitrated compounds.  The compositions may be used as corrosion-inhibiting lubricants for internal combustion engines, industrial machinery, fire arms and ordnance equipment or as turbine oils; in combination with fatty substances they may be used to form protective coatings for metal exposed to humid air.  An example illustrates the lubricating and corrosion-inhibiting properties of a 1 per cent solution of pentaerythritol monooleate mono allyl carbonate in phenoltreated mid-continent oil.  Other mixed carbonate esters mentioned are pentaerythritol di-oleate mono-petroleum carboxylate mono-ethyl carbonate, pentaerythritol mono-lauryl monohexyl carbonate, sorbitan mono-oleate mono-allyl carbonate, glycerol mono-stearate mono-allyl carbonate, dipentaerythritol mono-oleate di-C9 "oxo" carbonate, pentaglycerol mono-tall oil ester mono-allyl carbonate, tri-ethanolamine mono-stearate mono-allyl carbonate, tris (hydroxymethyl) amino methane mono-stearate mono-allyl carbonate, and tetramethylol cyclohexanol mono oleate mono-allyl carbonate. Specification 576,083, [Group IV], is referred to.