Patent GB-822730-A (GB)
Title: Process for preparing mixed triglyceride compositions
IPC: C11C3/10
Filed: 1956-06-21
Abstract: A process for preparing mixed triglycerides comprises continuously reacting in a reaction zone a higher acylated triglyceride containing higher acyl radicals having at least eight carbon atoms and a lower acylated triglyceride containing lower acyl radicals having from 2 to 6 carbon atoms in the presence of a plural metal soap catalyst as defined below at a temperature higher than 180 DEG  C., continuously withdrawing reaction mixture from said reaction zone, continuously subjecting the withdrawn reaction mixture to vacuum distillation in order to separate unreacted lower acylated triglyceride therefrom, continuously recycling the separated lower acylated triglyceride into said reaction zone, continuously subjecting the resulting distillation residue to thin film vacuum distillation in one or more stages in order to separate therefrom one or more fractions comprising a mixed triglyceride containing at least one of said higher acyl radicals and at least one of said lower acyl radicals and to leave a further distillation residue, continuously recycling the further distillation residue into said reaction zone and continuously introducing into said reaction zone make up materials comprising said higher acylated triglyceride and said lower acylated triglyceride. The mixed triglyceride product is a substantially fully esterified glyceride containing at least one of the lower acyl radicals and at least one of the higher acyl radicals and the plural metal soap catalyst is defined as comprising a soap or soaps containing at least two metals wherein one of the metals is an alkali or alkaline earth metal and the other metal is an amphoteric metal, said soaps or soaps being derived from one or more fatty acids having at least 5 carbon atoms.  Suitable amphoteric metals are aluminium, titanium, zirconium, cerium, tin, lead, cobalt, molybdenum, manganese, cadmium, iron, copper, chromium, vanadium, thallium, nickel, platinum, palladium and zinc.  The metal soaps may be added as such to the mixture or compounds containing the metals, e.g. oxides, alcoholates, chlorides and hydroxides can be added to the reaction mixture to form the plural metal soap in situ.  Specified plural metal soap catalysts are lithium aluminium stearate (or palmitate), sodium aluminium oleate, sodium titanium stearate, lithium (or strontium) titanium palmitate and calcium aluminium stearate.  The higher acylated triglycerides are preferably derived from animal fats or vegetable oils and can be either hydrogenated or unhydrogenated.  Suitable higher acylated triglycerides include trilaurin, tripalmitin and tristearin and those found in lard, beef tallow, cotton seed oil, soya bean oil, peanut oil, and coconut oil.  Suitable lower acylated triglycerides include triacetin, tripropionin, tributyrin, tri-isobutyrin, trivalerin and tricaproin.  Specified mixed triglyceride products are the mono-aceto distearin, diaceto monostearin, monobutyro distearin, dibutyro monostearin and di - isobutyrin which are obtained by reacting fully hydrogenated lard with the appropriate lower acylated triglyceride.ALSO:A process for preparing mixed triglycerides comprises continuously reacting in a reaction zone a higher acylated triglyceride containing higher acyl radicals having at least eight carbon atoms and a lower acylated triglyceride containing lower acyl radicals having from 2 to 6 carbon atoms in the presence of a plural metal soap catalyst as defined below at a temperature higher than 180 DEG  C., continuously withdrawing reaction mixture from said reaction zone, continuously subjecting the withdrawn reaction mixture to vacuum distillation in order to separate unreacted lower acylated triglyceride therefrom, continuously recycling the separated lower acylated triglyceride into said reaction zone, continuously subjecting the resulting distillation residue to thin film vacuum distillation in one or more stages in order to separate therefrom one or more fractions comprising a mixed triglyceride containing at least one of said higher acyl radicals and at least one of said lower acyl radicals and to leave a further distillation residue, continuously recycling the further distillation residue into said reaction zone and continuously introducing into said reaction zone make-up materials comprising said higher acylated triglyceride and said lower acylated triglyceride. The mixed triglyceride product is a substantially fully esterified glyceride containing at least one of the lower acyl radicals and at least one of the higher acyl radicals and the plural metal soap catalyst is defined as comprising a soap or soaps containing at least two metals wherein one of the metals is an alkali or alkaline earth metal and the other metal is an amphoteric metal, said soap or soaps being derived from one or more fatty acids having at least 5 carbon atoms.  Suitable amphoteric metals are aluminium, titanium, zirconium, cerium, tin, lead, cobalt, molybdenum, manganese, cadmium, iron, copper, chromium, vanadium, thallium, nickel, platinum, palladium and zinc.  The metal soaps may be added as such to the mixture or compounds containing the metals, e.g. oxides, alcoholates, chlorides and hydroxides can be added to the reaction mixture to form the plural metal soap in situ. Specified plural metal soap catalysts are lithium aluminium stearate (or palmitate), sodium aluminium oleate, sodium titanium stearate, lithium (or strontium) titanium palmitate and calcium aluminium stearate.  The higher acylated triglycerides are preferably derived from animal fats or vegetable oils and can be either hydrogenated or unhydrogenated.  Suitable higher acylated triglycerides include trilauric, tripalmitin and tristearin and those found in lard, beef tallow, cotton seed oil, soya bean oil, peanut oil, and coconut oil.  Suitable lower acylated triglycerides include triacetin, tripropionin, tributyrin, tri-isobutyrin, trivalerin and tricaproin.  Specified mixed triglyceride products are mono-aceto distearin, diaceto monostearin, monobutyro distearin, dibutyro monostearin and di-isobutyrin which are obtained by reacting fully hydrogenated lard with the appropriate lower acylated triglyceride.