Patent GB-822188-A (GB)
Title: Improvements in di(carboxyphenyl) alkanes and alkyd resins and processes for preparing the same
IPC: C07C63/331
Filed: 1956-06-29
Abstract: The invention comprises an alkyd resin which is an esterification reaction product of a polyhydric alcohol and an acid of the general formula <FORM:0822188/IV (a)/1> wherein R and R1 are alkyl groups containing 1 to 4 carbon atoms and n is 1 or 2 provided that the total number of carbon atoms in R and R1 is at least 3 when n is 1 and the carboxyl groups on the phenyl rings are in the 3,31- or 4,41-positions (see Group IV (b)).  Additional materials specified for use in the preparation of the alkyd resins include glyceride drying and non-drying oils and the fatty acids derived therefrom, compounds containing vinylidene groups, e.g. styrene, alkylated and halogenated styrenes, alkylacrylates and methacrylates and nitriles, e.g. acrylonitrile, methacrylonitrile and ethacrylonitrile and aliphatic di- and tricarboxylic acids and anhydrides thereof.  The alkyd resins may be combined with aminoplast resins, e.g. which may be obtained by reacting an aldehyde, e.g. formaldehyde with polyamino compounds, e.g. melamine, benzoguanamine, formoguanamine and acetoguanamine, urea, thiourea and ethylene ureas.  In examples: alkyd resins are obtained from 4,41-(2,2-butylidene) dibenzoic acid, soya fatty acids and glycerine (8); 4,41-(3,3-pentylidene) dibenzoic acid, tall oil fatty acids and propylene glycol (9); dimethyl 4,41-(1,1,2,2-tetramethylethylene) dibenzoate, methyl esters of dehydrated castor oil fatty acids, pentaerythritol and lead octoate (10); and 4,41-(3,3-pentylidene) dibenzoic acid, soya fatty acids and glycerine (13).  The alkyd resins are employed in coating compositions, e.g. with a solvent and cobalt naphthenate.ALSO:The invention comprises a dicarboxylic acid <FORM:0822188/IV (a)/1> wherein R and R1 are alkyl groups containing 1 to 4 carbon atoms and n is 1 or 2, provided that the total number of carbon atoms in R and R1 is at least 3 when n is 1 and the carboxyl groups in the phenyl rings are in the 3,31- or 4,41-positions and the alkyl esters thereof wherein the alkyl group contains from 1 to 12 carbon atoms and a process for the preparation of a dicarboxylic acid as defined above which comprises oxidizing a ditolyl alkane having the general formula <FORM:0822188/IV (a)/2> wherein R, R1 and n are as defined above, by oxidizing conditions known for converting a methyl-substituted phenyl group to the corresponding carboxyl-substituted phenyl group.  The oxidation may be carried out with concentrated nitric acid, chromic acid in acetic or sulphuric acid, potassium permanganate in presence of alkali, potassium dichromate in the presence of sulphuric acid or oxygen-containing gas.  Heavy metal catalysts may be employed e.g. the salts of cobalt, lead, iron nickel, manganese and magnesium salts of e.g. acetic, oleic, stearic, rosin and naphthenic acids.  The process may be carried at elevated or normal pressures and in the liquid or vapour phase. Examples relate to the preparation of 4,41-(1,1,2,2 - tetramethylethylene) -, 4,41 - (3,3-pentylidene) -, 4,41 - (1,1,2,2 - tetraethylethylene)- and 4,41-(2,2-butylidene)-dibenzoic acids and a dimethyl ester. The products are employed in the preparation of alkyd resins (see Group IV (a)).  Ditolyl alkanes are prepared by reacting compounds of the general formula <FORM:0822188/IV (a)/3> where R is hydrogen or an alkyl group containing 1 to 4 carbon p  atoms and n is 1 or 2 with an olefine having 2 to 4 carbon atoms or with with an alkyl halide having 1 to 4 carbon atoms.  2,2 - Di - (p - tolyl) butane is prepared by reacting 1,1-di-(p-tolyl) ethane with ethylene under pressure in the presence of o-toluic acid and sodium. 3,3-Di-(p-tolyl) pentane is prepared from 1,1-di-(p-tolyl) propane and ethylene in the presence of sodium and o-chloro-toluene.