CS217646B1 - Method of preparing aliphatic carboxylic acid esters - Google Patents

Description

The present invention relates to a process for preparing esters of aliphatic carboxylic acids having a carbon number of 8 to 22 with monosaccharides and disaccharides or mixtures thereof. These products are surfactants with good emulsifying ability and are used as additives to detergents, cosmetics and some food products.

These products are usually prepared by reacting carbohydrates with aliphatic carboxylic acid esters which are catalyzed by a base, usually potassium carbonate, in a polar solvent, typically dimethylformamide or dimethylisulfoxide, at a temperature of 80 to 120 ° C.

Other processes for the preparation of the above compounds employ nonpolar solvents such as xylene as media.

These methods have the common disadvantage that the solvent cannot be completely removed after the reaction is complete. It still has a considerable amount in the final products, which is a defect in applications in the food industry and cosmetics.

Over the years, processes have been developed using carbohydrate reactions in the presence of basic catalysts in which the carbohydrate is in the form of a melt at the start of the reaction. Their disadvantage is considerable decomposition of carbohydrate and high demands on technological equipment, especially in terms of possibility, rapid temperature changes.

A certain improvement in these processes is the addition of higher-carboxylic acid metal soaps mixed with glycerides. However, these substances are difficult to remove from the reaction mixture and their presence is also in some cases detrimental.

Most of these disadvantages are overcome by a solvent-free process for the production of aliphatic carboxylic acid esters with carbohydrates starting from esters of the above acids, preferably triglycerides, and monosaccharides and / or disaccharides, catalysed by a base, usually potassium carbonate, in the presence of an emulsifying agent usually mono- and diglycerides acids, phosphorylated mono- and diglycerides of aliphatic carboxylic acids or aliphatic carboxylic acid esters with monosaccharides and disaccharides.

The emulsifier is of key importance in the mixture since it allows interfacial transfer and hence the course of the reaction. However, this method of conducting the reaction requires a reaction time of 12 hours at 125 ° C, which is energy intensive.

According to the invention, the process for the preparation of esters of aliphatic carboxylic acids having 8 to 22 carbon atoms with monosaccharides and disaccharides starting from esters of the abovementioned acids, preferably triglycerides and monosaccharides and / or disaccharides, catalysed with a base, preferably potassium carbonate, in the presence of an emulsifier , preferably mono- and diglycerides of aliphatic carboxylic acids having a carbon number of 8 to 22 and / or phosphorylated mono- and diglycerides of the abovementioned acids and / or esters of the abovementioned acids with monosaccharides and / or disaccharides, characterized in that the ester of the abovementioned fatty acid, emulsifier and basic catalyst in a weight ratio of 100: 1: 1 to 100: 12: 15 and the mixture is stirred at 90 to 150 ° C for 1 to 2 hours before the monosaccharide and / or disaccharide is added in the mixture. 0.8 to 2.4 moles per mole of the starting ester; The mixture is then stirred at 10, 100 to 150 ° C for 3 to 6 hours.

The initial step, i.e. the reaction of the aliphatic carboxylic acid ester with a basic catalyst in the presence of an emulsifier, is of key importance since an aliphatic carboxylic acid salt is formed at the start of the reaction which together with the added emulsifier emulsifies the reaction mixture and increases the reaction rate.

The total reaction time is, on average, 6 hours, which is half that of conventional methods.

The reaction may be conducted either at atmospheric pressure or under vacuum.

The product can be used directly for the desired purpose or it can be bleached by adding 1 wt. hydrogen peroxide.

The raw materials are of common commercial origin and can be used regardless of natural or synthetic origin.

The preparation of the above products according to the invention is explained in more detail in the following examples, which are not to be construed as limiting.

Example 1

To a mixture of 150 g of coconut oil and 68 g of coconut oil monoglyceride was added at 120 ° C 10 g of anhydrous powdered potassium carbonate. The mixture was stirred at this temperature for 1 hour. Then add 68 g of sucrose powder and stirred at 125 ^{C for} 6 hours Celsius. After the remainder of the potassium carbonate has been precipitated, the mixture containing 49% sugar ester is bleached by the addition of 1% hydrogen peroxide 30%. The obtained sugar-glyceride is used as a cosmetic ingredient in hand paste.

Example 2

150 g of coconut oil is used 170 g of mink oil. Obtained product with a content of 45 why. Sugarester is added as a cosmetic ingredient to luxury toilet soaps.

Example 3

Same procedure as Example 1, instead of 68 g sucrose, 38 g sorbitol is used. The final 44 o / _o sugar ester product is a suitable emulsifier for the preparation of emulsions and creams.

Example 4

In the same manner as in Example 1, 170 g of tallow was used instead of 150 g of coconut oil and 7 g of phosphorylated diglyceride prepared from rapeseed oil was used instead of 6 g of coconut monoglyceride. The resulting 48% sugar ester product is used as an active ingredient in powdered detergents.

Example 5

In the same manner as in Example 1, instead of 6 g of coconut oil monoglyceride, 8 g of a 1: 1 weight ratio mixture of the above emulsifier with phosphorylated sunflower oil diglyceride was used. The obtained 49% sugar ester product is used as an oil-in-water emulsifier. Example 6

In the same manner as in Example 1, instead of 6 g of coconut monoglyceride, 6 g of a 1: 1 weight ratio mixture of mono- and diglycerides and sucrose ester with lauric acid is added. The final product containing 50% sugar ester is added as a cosmetic ingredient to the foam baths.

Example 7

In the same manner as in Example 1, instead of 150 g of coconut oil, 60 g of oleic acid methyl ester was used. The 80% sucrose ester mixture obtained is used as a food emulsifier.

Example 8

In the same manner as in Example 1, instead of 150 g of coconut oil, 120 g of ethyl stearate was used. The final product, containing 70 v _/ higher esters of sucrose was used as an inhibitor of fat bloom in chocolate products.

Same procedure as in Example 1, instead

Claims (2)

SUBJECT A process for preparing esters of aliphatic carboxylic acids having a carbon number of 8 to 22 with monosaccharides and disaccharides, starting from esters of the abovementioned acids, preferably triglycerides, and monosaccharides and / or dsaccharides, catalyzed by a base, preferably anhydrous potassium carbonate. diglycerides of aliphatic carboxylic acids having a carbon number of 8 to 22 and / or phosphorylated monoglycerides and diglycerides of the abovementioned acids and / or SUMMARY OF THE INVENTION The esters of the above acids with monosaccharides and disaccharides, characterized in that the ester of the above acids, emulsifier and basic catalyst are first mixed in a weight ratio of 100: 1: 1 to 100: 12: 15 and the mixture is stirred at 90-150 ° C for 1 to 2 hours, and then 0.8 to 1.5% monosaccharide and / or disaccharide is added 2.4 moles per mole of the starting ester and the reaction mixture was stirred at 100-150 ° C for 3-6 hours.