GB785933A - Process for the preparation of fatty acid esters suitable for use as ointment bases and the like carrier media - Google Patents

Abstract

Fatty acid ester mixtures suitable for use as ointment bases, suppository masses and like carrier media are obtained by esterifying a mixture of two or more different fatty acids having an iodine number less than 5 and having 12 to 18 carbon atoms per molecule, with an excess of a polyhydric alcohol, the relative amounts of the fatty acids and the alcohol and the number and kind of the fatty acids being so chosen that there are obtained mixtures of partial esters of the two or more fatty acids, containing free OH groups, with complete esters of these two or more fatty acids, which mixtures have a melting point of less than 40 DEG C., preferably of 33 DEG to 37 DEG C. The term "two or more different fatty acids" excludes fatty acid mixtures in which the fatty acids are present in a quantitative proportion corresponding substantially to fatty acid compositions derived from natural oils and fats. Specified fatty acids are lauric, myristic, palmitic, and stearic acids and specified polyhydric alcohols are ethylene-, propylene-, and trimethylene-glycols, 1,2-dimethyl ethylene glycol, thio glycols, glycerol, erythritol, pentaerythritol, and mannitol. In examples: (1) a mixture of 60 parts lauric acid and 40 parts stearic acid is esterified with 14.8 parts of glycerine to yield a hard brittle product melting at 35-37 DEG C.; (2) a mixture of 300 parts lauric acid and 200 parts myristic acid is esterified with 83.5 parts glycerine to yield a product which melts at about 33 DEG C.; (3) a mixture of 250 parts lauric acid and 250 parts myristic acid is esterified with 83.5 parts glycerine to yield a product which melts at about 36 DEG C.; (4) a mixture of 350 parts myristic acid and 150 parts lauric acid is esterified with 83.5 parts glycerine to yield a product melting at 39.5 DEG C.; (5) a mixture of 375 grams stearic acid and 125 grams palmitic acid is esterified with 95 grams 1,2-dimethyl ethylene glycol in the presence of zinc dust under vacuum or in a stream of carbon dioxide to yield a product melting at 33 DEG C. In Examples 1 to 4 the esterification is effected at a temperature of from 120 DEG to 200 DEG C. and at a pressure of 3-6 mm. of mercury using zinc dust as catalyst. A similar amount of palmitic acid may be used instead of myristic acid in (2), (3) or (4). It is stated that one of the fatty acids may first be esterified so as to convert part thereof to monoglyceride and the remaining fatty acid added to the reaction mixture after about two hours esterification and the esterification continued to form the desired partial ester and full ester mixture. The products are also stated to be useful in the manufacture of stable emulsions and in the manufacture of chocolate goods, baked goods, food fats and mayonaisses (see Groups I and VI). Specification 694,970 is referred to.ALSO:A mixture of partial and complete fatty acid esters having a melting point less than 40 DEG C. obtained by esterifying a mixture of two or more different fatty acids having an iodine number less than 5 and having 12 to 18 carbon atoms per molecule with an excess of a polyhydric alcohol (see Group IV(b)), is used in the manufacture of foodstuffs, e.g., food fats. The term "two or more different fatty acids" excludes fatty acid mixtures in which the fatty acids are present in a quantitative proportion corresponding substantially to fatty acid compositions derived from natural oils and fats. Specified fatty acids are lauric, myristic, palmitic, and stearic acids and specified polyhydric alcohols are ethylene-, propylene-, and trimethylene glycols, 1, 2-demethyl ethylene glycol, thioglycols, glycerol, erythritol, pentacrythritol, and mannitol. Specified products referred to are the mixed esters obtained from glycerol and a mixture of lauric acid with stearic acid, myristic acid, and palmitic acid respectively and from a mixture of stearic acid and palmitic acid with 1, 2-dimethyl ethylene glycol. A 1 : 1 mixture of coconut fat and the mixed ester product (m.p. 39,5 DEG C.) obtained by esterifying a mixture of myristic acid and lauric acid with glycerine is stated to be suitable for use in the confectionery trade. Specification 694,970 [Group IV(b)] is referred to.ALSO:A mixture of partial and complete fatty acid esters having a melting-point less than 40 DEG C. obtained by esterifying a mixture of two or more different fatty acids having an iodine number less than 5 and having 12 to 18 carbon atoms per molecule with an excess of a polyhydric alcohol (see Group IV (b)) is used in the manufacture of foodstuffs, e.g. chocolate goods, baked goods, and mayonnaises. The term "two or more different fatty acids" excludes fatty acid mixtures in which the fatty acids are present in a quantitative proportion corresponding substantially to fatty acid compositions derived from natural oils and fats. Specified fatty acids are lauric, myristic, palmitic, and stearic acids and specified polyhydric alcohols are ethylenepropylene-, and trimethylene glycols, thioglycols, glycerol, erythritol, pentaerythritol, and mannitol. Specific products referred to are the mixed esters obtained from glycerol and a mixture of lauric acid with stearic acid, myristic acid, and palmitic acid respectively and from a mixture of stearic acid and palmitic acid with 1,2-dimethylethylene glycol. A 1 : 1 mixture of coconut fat and the mixed ester product (m.p. 39.5 DEG C.) obtained by esterifying a mixture of myristic acid and lauric acid with glycerine is stated to be suitable for use in the confectionery trade. Specification 694,970, [Group IV (b)], is referred to.