GB584971A - Improvements relating to the preparation of polyol compositions - Google Patents

Abstract

Polyol compositions may be prepared by reacting water and a water-soluble saturated polyol, containing only carbon, hydrogen and and oxygen and having from 3 to 12 carbon atoms and at least 3 hydroxyl groups with an olefine oxide containing not more than 5 carbon atoms, and esterifying the reaction product with an aliphatic straight chain saturated monocarboxylic acid having at least 16 carbon atoms. The polyols, i.e. polyhydric alcohols and carbohydrates, which may have substituent groups containing two or more of the elements carbon, oxygen and hydrogen, such as alkyl, aryl, acyl and ether groups, include glycerol and higher polyhydric alcohols, cyclitols such as the inositols, partially alkylated cyclitols such as quebrachitol and pinitol, diglycerol and the lower poly-glycerols, pentaerythritol, di-pentaerythritol and other pentaerythritol ethers, hexitans such as sorbitan and mannitan, hexitols such as sorbitol and mannitol, saccharides such as glucose, fructose, lower alkyl glucosides, sucrose, lactose, trehalose, glucosan, mannosan, lactones such as glyconic lactone and mixed polyols obtained by the partial reduction of sugar. Polyols containing up to 6 carbon atoms are preferred. The polyol may be mixed with, say, 0.08 to 1.5 mols. of water for each hydroxyl group present in the polyol and the mixture is then reacted with the olefine oxide, preferably, ethylene or propylene oxide or a mixture thereof, though butylene and amylene oxides may also be used. Generally, the quantity of olefine oxide should not be less than 0.4 times the total number of gram equivalents of hydroxyl group present in the polyol and water, and not less than 1.5 times each gram equivalent of water employed; preferably sufficient should be used to give a final product having a freezing point above about 30 DEG C. The olefine oxide may be added in liquid or gaseous form to the polyol-water mixture in a stirred pressure vessel, suitably at 80 DEG to 140 DEG C. under elevated pressures. Acid or basic condensation catalysts may be present, for example, boric acid, sodium oleate, sodium methylate, disodium hydrogen phosphate, acid salts such as sodium dihydrogen phosphate, zinc chloride and mineral acids such as sulphuric and phosphoric acids. Esterification of the condensation product may be by direct esterification at 150 DEG to 280 DEG C. with agitation in closed reaction vessels, the water formed being removed by distillation; esterification catalysts may be added, but the catalyst from the condensation reaction often suffices. The esterifying acid should generally be present in molal quantities equivalent to at least one-half the hydroxyl equivalents in the original polyol plus one-half the mol. equivalents of water used. The preferred esterifying acid is stearic acid, either the pure or double- and triple-pressed acids or completely hydrogenated olive acid; likewise, hydrogenated fish oil, soya and palmitic acids and mono-basic acids from paraffinic oxidations may be used. The esterified product may be decolourised by treatment with decolourising carbons, activated earths, hydrogen peroxide or benzoyl peroxide. In modifications, up to 50 per cent of the esterifying acid may be reacted with the polyol prior to reaction with the olefine oxide, or a minor amount of the olefine oxide may be first reacted with some of the polyol or the water. If sufficient long chain ester is present to produce desired waxiness and freezing point, without esterification being complete, then the product may be further esterified by means of lower aliphatic, aromatic and polybasic carboxylic acids. The products are waxy solids, soluble in hydrocarbon solvents and form emulsions in warm water with the aid of dispersing agents. They may also be used in cosmetic preparations, yarn sizes, lubricants and polishes. In examples: (1) sorbitol containing 5 per cent water is reacted in an autoclave at 90 DEG C. with ethylene oxide using sodium methylate as catalyst and the product esterified with stearic acid at 270 DEG C. in an inert atmosphere and decolourised with carbon; (2) sorbitol containing 15 per cent water and some sodium sulphate and prepared by electrolytic reduction of glycose is similarly reacted with ethylene oxide and the product esterified with hydrogenated soya oil fatty acids; (3) glycerine containing 5 per cent water is reacted with ethylene oxide and the product esterified with stearic acid, as in (1) above; (4) sorbitol containing 5-6 per cent water is reacted with propylene oxide in the presence of sodium methylate and then with hydrogenated soya oil fatty acids; (5) glycose, water and ethylene oxide are reacted in the presence of boric acid and the product esterified with stearic acid, decolourised with carbon and bleached with aqueous hydrogen peroxide; any inorganic acidity may be neutralized by means of, for example, sodium or calcium carbonate.