Patent GB-620678-A (GB)
Title: Improvements in or relating to composite ester material and method of forming the same
IPC: C08L27/04
Filed: 1946-04-15
Abstract: A triglyceride of a hydroxy substituted 18 carbon atom aliphatic hydrocarbon monocarboxylic acid, e.g. castor oil or hydrogenated castor oil, is subjected to partial alcoholysis at a temperature below 200 DEG  C. and preferably from 50 DEG  to 150 DEG  C. with a polyhydric alcohol containing less than 12 carbon atoms (see Group IV (b)).  The products are stated to contain not only various esters and polyesters but also any excess unreacted polyhydric alcohol as well as a small amount of glycerine which may have been liberated during the reaction.  In an example in which castor oil is heated with 1.3-butanediol in the presence of isopropyl alcohol (as inert solvent) and sodium hydroxide (as alcoholysis catalyst) benzene is added to the mixture and the solution obtained is washed with hot water to remove the catalyst, any excess polyhydric alcohol and any glycerine that may have been formed.  U.S.A. Specification 2,015,145 is referred to.ALSO:Composite material containing mixtures of complex esters are produced (see Group IV (b)) by subjecting a triglyceride of a hydroxy-substituted 18 carbon atom aliphatic hydrocarbon monocarboxylic acid to partial alcoholysis at a temperature below 200 DEG  C. and preferably from 50 DEG  to 150 DEG  C. with a polyhydric alcohol containing less than 12 carbon atoms and containing hydroxyl groups only or containing in addition to its hydroxyl groups no constituents other than carbon, hydrogen and ether-oxygen and then acylating the resulting intermediate product to replace the hydrogen atoms of the free hydroxyl groups therein with saturated fatty acid radicals containing less than 5 carbon atoms to obtain the composite ester material in crude form and passing superheated steam through the crude product at reduced pressure and at a temperature of 100 DEG to 250 DEG  C. to volatilise odoriferous impurities and leave a residue consisting of the composite ester material in purified completely odourless form. The triglyceride is generally either castor oil or hydrogenated castor oil.  The composite ester products are stated to be valuable plasticisers for synthetic resins, thus they may be used to plasticise cellulose esters and ethers, natural or synthetic rubbers, vinyl resins, e.g. polystyrene, polyacrylic esters, polyvinyl esters, polyvinyl acetals, polyvinyl halides, polymers of vinyl chloride and of vinylidene chloride and co-polymers of these materials with each other and with lesser proportions of other ethylenic compounds such as vinyl acetate, vinyl butyrate, acrylic and methacrylic esters.  U.S.A. Specification 2,015,145 is referred to.ALSO:Composite material containing mixtures of complex esters are produced by subjecting a triglyceride of a hydroxy-substituted 18 carbon atom aliphatic hydrocarbon monocarboxylic acid to partial alcoholysis at a temperature below 200 DEG  C. and preferably from 50 DEG  to 150 DEG  C. with a polyhydric alcohol containing less than 12 carbon atoms and containing hydroxyl groups only or containing in addition to its hydroxyl groups no constituents other than carbon, hydrogen and ether-oxygen and then acylating the resulting intermediate product to replace the hydrogen atoms of the free hydroxyl groups therein with saturated fatty acid radicals containing less than 5 carbon atoms to obtain the composite ester material in crude form and passing superheated steam through the crude product at reduced pressure and at a temperature of 100 DEG to 250 DEG  C. to volatilize odoriferous impurities and leave a residue consisting of the composite ester material in purified completely odourless form.  The triglyceride is generally either castor oil or hydrogenated castor oil, the latter consisting chiefly of 12-hydroxy stearic with small amounts of the triglycerides of stearic and dihydroxy stearic acid.  The polyhydric alcohols preferably contain at least one primary hydroxyl group and those specified are glycerine, erythritol, pentaerythritol, arabitol, xylitol, adonitol, mannitol, dulcitol, sorbitol, pentaglycerine, p xylylene glycols, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, trimethylene glycol, tetra-, nona- and undecamethylene glycols, isobutylene glycol, 2,2-dimethyl trimethylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-butanediol, 2,3-butanediol, pinacol and 2-ethyl-1,3-hexane diol.  The acylating agent is preferably used in excess and may be an acid, acid chloride or acid anhydride, the specified fatty acid radicals being those of acetic, propionic, butyric and isobutyric acids.  When the anhydride is used it is suitable to acylate at a temperature of 100 DEG  to 200 DEG  C.  The alcoholysis is preferably conducted in the presence of an acidic or basic alcoholysis catalyst, e.g. hydrochloric acid, sulphuric acid, sodium hydroxide, potassium hydroxide, the lead salts of organic acids, e.g. lead formate, lead acetate, lead oleate, or volatile basic catalysts such as a secondary or tertiary amine, e.g. trimethyl amine, diethylamine, tributyl amine or pyridine.  The inorganic bases are the preferred catalysts.  The alcoholysis may be effected in the presence of an inert solvent, e.g. the secondary and tertiary alcohols such as isopropyl alcohol, secondary and tertiary butyl alcohol and 2-pentanol and the alcoholysis is effected so that a substantial number of the ester linkages present in the glyceride should be broken or replaced, but not all of them, thus at least 20 per cent of the original ester linkages but not more than 95 per cent should be broken or replaced with new ester linkages. The composite material obtained from the alcoholysis reaction contains various esters and polyesters, excess (or unreacted) polyhydric alcohol, a small amount of glycerine, and the catalyst, and these may be removed by distillation or extraction with a selective solvent such as water. The addition of a hydrocarbon solvent, e.g. benzene or toluene to dissolve the esters is also advantageous.  In examples (1), a mixture of 1,3-butanediol, sodium hydroxide and isopropyl alcohol is heated to dissolve the sodium hydroxide, castor oil added and the whole heated, the mixture is cooled somewhat, benzene added and the solution washed with hot water to remove the catalyst, excess polyhydric alcohol and any glycerine present.  The mixture is then heated to remove benzene and water, excess acetic anhydride added and the mixture heated.  The excess acetic anhydride is removed by heating at reduced pressure and the product purified by heating it at reduced pressure and passing superheated steam at a temperature of about 135 DEG  to 150 DEG  C. through it.  The product is finally distilled at low pressure; (2) to (5) ethylene glycol, glycerine, diethylene glycol and triethylene glycol respectively are similarly reacted with castor oil followed by acetylation with acetic anhydride; (6) a mixture of lead oleate, lead formate and castor oil is heated while pentaerythritol is added slowly, the acetylation and treatment with superheated steam being then effected as in (1); (7) 2-ethyl-1,3-hexanediol, isopropyl alcohol and metallic sodium are heated to dissolve the latter, castor oil is then added and the mixture heated and the acetylation &c. continued as in (1); (8) ethylene glycol, sodium hydroxide and isopropyl alcohol are heated to dissolve the sodium hydroxide, hydrogenated castor oil is then added and the acetylation &c. continued as in (1).  The product of examples (1) to (5) and (7) are stated to consist of a mixture of the mono-, di- and tri-(acetylricinoleate) esters. U.S.A. Specification 2,015,145 is referred to.