GB932047A - Lubricant compositions and additives for use therein - Google Patents

Abstract

A normally liquid lubricant which does not gel at elevated temperatures comprises (a) a major proportion of a hydrocarbon lubricating oil, (b) 0,01-25% by weight of an alkaline-earth-neutralized reaction product of a phosphorus sulphide and a normally non-gaseous hydrocarbon and (c) 0,05-10% by weight of a zinc dialkyl dithiophosphate formed from the acid product produced by reacting P2S5 with an alcohol selected from C4-C18 primary alkyl alcohols and mixtures of alkyl alcohols consisting of 30-70 mol. per cent of primary C4-C18 alkyl alcohol and 70-30 mol. per cent of secondary C3-C18 alkyl alcohol, at least one of the alkyl alcohols of such mixtures containing at least 8 carbon atoms, and the ratio of ingredient (b) to ingredient (c) being from 0,75:1 to 20:1 by weight. The term "alkyl" is used to include both saturated and unsaturated aliphatic hydrocarbon radicals. If desired a concentrate of ingredients (a), (b) and (c) may be prepared containing more than 25% of (b) and more than 10% of (c) and the lubricant prepared when desired by diluting the concentrate with further hydrocarbon lubricating oil. The lubricant may contain additional ingredients such as corrosion inhibitors (e.g. sulphurized dipentene), a polymerized high molecular weight fatty acid, pour point depressors, anti-wear agents, anti-oxidants, sulphonates and V.I. improvers. Oils suitable as ingredient (a) are petroleum distillates or residuums, synthetic hydrocarbon oils or mixtures thereof. The non-gaseous hydrocarbon used in preparing ingredient (b) may be an olefin polymer or copolymer, a high molecular weight olefinic hydrocarbon (e.g. cetene, cerotene, melene, paraffin wax olefins or alkenes from cracked petroleum oils), an aromatic hydrocarbon, an essentially paraffinic hydrocarbon material (e.g. brightstock residuums, lubricating oil distillates, petrolatums, paraffin waxes), or the condensation product of such paraffinic material with aromatic hydrocarbons. The phosphorus sulphide may be P2S5, P2S3, P4S3 or P3S7 and may be used in the presence of a sulphurizing agent. The phosphosulphurized material may be subjected to various treatments such as hydrolysis with steam and contact with an adsorbent material or a basic alkaline earth compound before being neutralized with a basic alkaline earth compound such as barium oxide or hydroxide. In the examples, ingredient (a) is a petroleum lubricating oil, ingredient (b) is a barium-neutralized reaction product of P2S5 and polybutene and ingredient (c) is a zinc dialkyl dithiophosphate derived from iso-octyl alcohol, n-amyl alcohol, n-heptyl alcohol, a mixture of isopropyl alcohol and iso-octyl alcohol or a mixture of isopropyl alcohol and n-heptyl alcohol. In some examples, the lubricant also contains sulphurized dipentene and/or polymerized linoleic acid. For comparison purposes, the effect of using a zinc dialkyl dithiophosphate prepared from methyl isobutyl carbinol as ingredient (c) in the compositions of the examples is described. Specification 744,779 is referred to.ALSO:An alkaline-earth-neutralized reaction product of a phosphorus sulphide and an olefin polymer is employed as an ingredient of a lubricating composition (see Group III). The olefin polymer may result from the polymerization of low molecular weight mono-olefinic hydrocarbons or iso-mono-olefinic hydrocarbons, such as propylenes, butylenes and amylenes, or the copolymers obtained by the polymerization of hydrocarbon mixtures containing isomono-olefins and mono-olefins of less than 6 carbon atoms. Thus materials which may be polymerized include a mixture (derived from cracked petroleum) comprising isobutylene, butylenes and butanes and a mixture comprising propane and propylene. The phosphorus sulphide may be P2S5, P2S3, P4S3 or P3S7 and may be used in the presence of a sulphurizing agent. It is preferred to use P2S5 at elevated temperature in the presence of nitrogen or other non-oxidizing atmosphere. The phosphosulphurized material may be subjected to various treatments such as hydrolysis with steam and contact with an adsorbent or a basic alkaline earth compound before being neutralized with a basic alkaline earth compound such as barium oxide or hydroxide. In the examples of lubricating compositions, the salt of a phosphosulphurized polymer employed is a barium-neutralized reaction product of P2S5 and a polybutene of about 1,000 molecular weight. Specification 744,779 is referred to.ALSO:Ingredients of a lubricating composition (see Group III) include (1) a zinc dialkyl dithiophosphate formed from the acid product produced by reacting P2S5 with an alcohol selected from C4-C18 primary alkyl alcohols and mixtures of alkyl alcohols consisting of 30-70 mol per cent of primary C4-C18 alkyl and 70-30 mol per cent of secondary C3-C18 alkyl alcohol, at least one of the alkyl alcohols of such mixtures containing at least 8 carbon atoms and the term "alkyl" being used to include both saturated and unsaturated aliphatic hydrocarbon radicals and (2) an alkaline-earth-neutralized reaction product of a phosphorus sulphide and a normally nongaseous hydrocarbon. The zinc dialkyl dithiophosphate may be derived from such primary alcohols as n- and iso-butanols, pentanols, octanols and nonanols, n-decanol, n-dodecanol, 2-ethyl-1-hexanol, isooleyl, cetyl or stearyl alcohol and the oxo alcohols, or mixtures thereof with such secondary alcohols as isopropanol, methyl ethyl, methyl n-propyl, methyl n-hexyl or methyl isobutyl carbinols and 1-methyl-1-pentanol. In an example, a mixture of n-decanol and isopropanol is reacted with a mineral oil slurry of P2S5 at elevated temperature and the acid product neutralized with a mineral oil slurry of zinc oxide at elevated temperature, blown with inert gas while hot and filtered. In further examples, using the same method, the alcohol employed is isooctanol, n-decanol, or a mixture of isopropanol and iso-octanol with or without n-butanol. The alkaline earth salt of phosphosulphurised hydrocarbon may be derived from such non-gaseous hydrocarbons as high molecular weight olefinic hydrocarbons (e.g. cetene, cerotene, melene, paraffin wax olefins or alkenes from cracked petroleum oils), aromatic hydrocarbons, essentially paraffinic hydrocarbon materials (e.g. bright stock residuums, lubricating oil distillates, petrolatums or paraffin waxes) or the condensation products of such paraffinic materials with aromatic hydrocarbons. The phosphorus sulphide may be P2S5, P2S3, P4S3 or P3S7 and may be used in the presence of a sulphurizing agent. It is preferred to use P2S5 at elevated temperature in the presence of nitrogen or other nonoxidizing atmosphere. The phosphosulphurised material may be subjected to various treatments such as hydrolysis with steam and contact with an adsorbent material or a basic alkaline earth compound before being neutralized with a basic alkaline earth compound such as barium oxide or hydroxide. Specification 744,779 is referred to.