Patent GB-820571-A (GB)
Title: Improvements in or relating to polyesters
Inventor: LERER MOISE
IPC: C08G65/332
Filed: 1956-06-07
Abstract: Aqueous emulsions comprise as emulsifying agents polyesters obtained by esterifying a polyethylene glycol with castor oil in the presence of an esterification catalyst at a temperature from 150-250 DEG  C., the molar proportion of castor oil to the glycol being greater than twothirds, removing in specified manner the liberated glycerol as it is formed and continuing the esterification until the amount of glycerol liberated is greater than that stoichiometrically equivalent to the quantity of polyethylene glycol introduced as reagent (see Group IV (b)). The emulsion may also comprise one or more organic substances insoluble in water such as hydrocarbons, mineral oils, long-chain liquid alcohols, fatty acids, vegetable oils and animal oils and a number of such substances are named.  Metallic salts may be present.  Polyesters derived from a polyethylene glycol of M.W. 400 are described in examples.  Lubricants comprise the polyesters described above which may be used as such, in admixture with motor fuels or in the form of aqueous emulsions as above mentioned. Reference is made to the use of the polyesters in motor spirits and ternary high octane fuels and in the form of 10% aqueous emulsions.ALSO:Polyesters are prepared by esterifying a polyethylene glycol with castor oil in the presence of an esterification catalyst at a temperature from 150 DEG -250 DEG  C., the molar proportion of castor oil to the glycol being greater than 2/3 , removing the liberated glycerol as it is formed by distillation under reduced pressure or by azeotropic distillation with a solvent capable of forming an azeotropic mixture with glycerol without any substantial removal of the polyethylene glycol, and continuing the esterification until the amount of glycerol liberated is greater than that stoichiometrically equivalent to the quantity of glycol introduced as reagent.  An inert gas may be passed through the reaction mixture to facilitate removal of the glycerol.  The catalyst may be an alkali metal or an oxide, hydroxide or organic salt thereof. The products, which may be used in lubricants or as emulsifying agents (see Group III) are esterified to a greater extent than corresponds to the simple di-ricinoleates of the glycol and the greater the excess of castor oil the greater the amount of higher poly-esters formed.  The preferred products are those obtained when at least 60% by weight of the glycerol theoretically capable of liberation has been liberated. The products may be purified by washing with an aqueous inorganic salt solution, by treating the product or its organic solution with an absorbent substance, e.g. silica gel or a bleaching earth or by treating the product as an aqueous or organic solution thereof with a cation exchanger, then with an anion exchanger and finally with a mixture of both. Examples are given wherein polyethylene glycols of M.W. 400 are used.ALSO:Polyesters are prepared by esterifying a polyethylene glycol with castor oil in the presence of an esterification catalyst at a temperature from 150 DEG  to 250 DEG C., the molar proportion of castor oil to the glycol being greater than 2/3 , removing the liberated glycerol as it is formed by distillation under reduced pressure or by azeotropic distillation with a solvent capable of forming an azeotropic mixture with glycerol without any substantial removal of the polyethylene glycol, and continuing the esterification until the amount of glycerol liberated is greater than that stoichiometrically equivalent to the quantity of polyethylene glycol introduced as reagent.  An inert gas may be passed through the reaction mixture to facilitate removal of the glycerol.  The catalyst may be an alkali metal or an oxide, hydroxide or organic salt thereof.  The products, which may be used in lubricants and as emulsifying agents (see Group III), are esterified to a greater extent than corresponds to the simple di-ricinoleates of the glycol and the greater the excess of castor oil the greater the amount of higher poly-ester formed.  The preferred products are those obtained when at least 60% by weight of the glycerol theoretically capable of liberation has been liberated.  The products may be purified by washing with an aqueous inorganic salt solution, by treating the product or an organic solution thereof with an absorbent substance, e.g. silica gel or bleaching earth or preferably by treating the product or its aqueous or organic solution with a cationic ion-exchanger, then with an anionic ion exchanger and finally with a mixture of both.  Examples are given wherein polyethylene glycols of M.W. 400 are used.