Patent GB-652683-A (GB)
Title: Improvements in or relating to organo thio acids of phosphorus and improved hydrocarbon compositions
IPC: C07F9/201
Filed: 1947-09-25
Abstract: Methyl diorganodithiophosphates or methyl diorganomonothiophosphites, wherein the methyl group is substituted with a hydroxy aromatic hydrocarbon radical or a metal salt thereof, said hydroxy aromatic radical containing an alkyl substituent of at least four carbon atoms, are prepared by reacting at least one phenol, or a metal salt thereof, containing up to three chlormethyl radicals and an alkyl group of at least four carbon atoms attached to the aromatic nucleus with a diester of dithiophosphoric acid or monothiophosphorus acid, or with a metal salt of such diesters.  The products are exemplified by the following formula: <FORM:0652683/IV (b)/1> wherein Ar is an aromatic group, R is a hydrocarbon radical, i.e. an alkyl, aryl or alkaryl group which may or may not contain one or more of the following substituents: halogen atoms, hydroxyl groups, carboxyl groups, ester groups, ether groups, or thioether groups, n is 0 or 1, m is 1 to 3, T is hydrogen or a metal and R1 is an alkyl group containing at least 4 carbon atoms. The product may be reacted with a metal base or alcoholate to form a metal salt.  The chlormethyl phenol may be prepared by reacting a phenol containing the desired alkyl substituent with formaldehyde in the presence of hydrogen chloride.  Phenols mentioned which may be reacted with formaldehyde and hydrochloric acid are p-tert.-octyl phenol, phenols extracted from petroleum oils, naturally occurring phenols such as those found in vegetable oils, e.g. cardanol, and alkylated phenol sulphides, including those of the formula <FORM:0652683/IV (b)/2> where R represents at least one alkyl group of at least 4 carbon atoms and x is 1 or 2.  Alkyl groups may be introduced into the phenols, when necessary, by the alkylation with olefins including mixtures of olefins such as those obtained in cracked petroleum fractions, e.g. p-tertiary octyl phenol is obtained by reacting phenol and diisobutylene in the presence of sulphuric acid, or by the alkylation of phenols with alkyl halides including chlorinated paraffin wax and chlorinated petrolatums derived from petroleum. The chlorinated waxes may contain dichlorides and polychlorides, and may be used in alkylating phenols by the Friedel-Croft synthesis to give complex alkylated phenols in which several phenol radicals are linked by alkyl radicals in a single molecule. In examples: (1) tert.-octylhydroxyphenylmethyldioctyldithiophosphoric acid is prepared from p-tert. octyl phenol and dioctyldithiophosphoric acid (obtained by condensing n-octyl alcohol and phosphorus pentasulphide), and is converted to its calcium salt; (2) chlormethyl-tert.-octylphenol is condensed with di - (tert. - octylthiomethyl - tert. - octylphenyl)-thiophosphite (obtained by reacting tert.-octylthiomethyl - tert. - octylphenol and phosphorus heptasulphide) and the product is converted to its calcium salt. Other chlormethyl phenols mentioned are o-chlormethyl-p-diisobutyl phenol, bis o-chlormethyl-p-diisobutyl phenol, chlormethyl bis-(5-diisobutyl-2-hydroxy phenyl) methane and bis-(5-diisobutyl - 3 - chlormethyl - 2 - hydroxy phenyl) methane (all obtained by reacting p-tert.-octyl phenol with formaldehyde in the presence of hydrogen chloride).ALSO:A composition comprises a petroleum hydrocarbon oil and an aromatic methylene derivative of a thio acid of phosphorus obtained by reacting at least one phenol, or a metal salt thereof, containing up to three chlormethyl groups and an alkyl group of at least 4 carbon atoms attached to the aromatic nucleus with a diester of dithiophosphoric acid or monothiophosphorous acid, or with a metal salt of such diesters.  The thio acids may be of the general formula <FORM:0652683/III/1> where Ar is an aromatic group, R is a hydrocarbon radical, i.e. an alkyl, aryl, or alkaryl group which may or may not contain one or more of the following substituents: halogen atoms, hydroxyl groups, carboxyl groups, ester groups, ether groups or thioether groups, n is 0 or 1, m is 1 to 3, T is hydrogen or a metal and R1 is an alkyl group containing at least 4 carbon atoms.  A number of phenols that may be used to prepare the thio-acid are specified.  Oils that may be used in the compositions are lubricating oils, e.g. those obtained by the distillation of paraffinic, naphthenic and asphaltic crude oils or mixtures thereof, synthetic oils derived by cracking, polymerization and condensation, waxes and fuel oils.  Other substances which may be added to the compositions are fatty acid and naphthenic acid soaps, fatty oils, esters, sulphur and halogen compounds, thickeners such as polyisobutylene having a molecular weight about 1000, oil-soluble metal soaps, alcohols having 8 or more carbon atoms including olefinic, cyclic and aryl substituted alkyl alcohols.  In the examples, the calcium salt of tert.-octylhydroxyphenylmethyl dioctyldithiophosphoric acid and the calcium salt of the condensation product of di-(tert.-octylthiomethyl - tert. - octylphenyl) thiophosphite and chlormethyl-tert.-octyl phenol are added to lubricating oils.