RO115537B1 - Process for preparing fatty acid salts from triglycerides in solvents - Google Patents

Abstract

The invention relates to a process of preparing fatty acid salts from triglycerides in solvents According to the invention, the process consists in a first step, wherein the triglycerides are treated with methanol in ratio of 16 21 % by weight as compared with the triglycerides and with hydroxide in ratio of 05 4 % by weight as compared with the methanol, and in the second step, the reaction mass is saponified with hydroxide in a molar ratio of 3 : 1 as compared with the triglycerides, in a mixture of methanol with solvent, used in a ratio of 250 500 % by weight as compared with the triglycerides, the reaction mass is heated and treated thereafter with conditioning ingredients

Description

The invention relates to a process for obtaining fatty acid salts, from triglycerides, in solvents, also known as soaps, and which, depending on the cation contained, are used as detergents, in lubricant compositions, catalysts or as auxiliaries in the industry. textile, leather, etc.

The process for the preparation of sodium and lithium salts of fatty acids is known by saponification of triglycerides with aqueous solutions of alkali hydroxides, using acetonitrile as a solvent at reflux temperature. After completion of the reaction, the respective soaps precipitated by cooling are separated from the solvent, by filtration and drying, with an overall yield of 90% (US 4075234).

Although the process eliminates many of the drawbacks of classical water saponification procedures, it has some disadvantages. Thus, due to the use of aqueous solutions of alkaline hydroxides, the soap contains between 7 and 10% water. In the case of potassium salts, a sticky paste results from which the solvent cannot be separated by filtration. Glycerin separation is not achieved, this accumulating in the filtrate, impurified with the water introduced into the system, by the alkaline hydroxide solution.

Also, the process of acetone saponification of triglycerides with an aqueous solution of alkaline hydroxide in the presence of a small amount of sodium chloride at reflux temperature is known. The precipitated soaps are separated from the solvent by filtration and drying, with yields of 90-99% (US 4337209).

This process eliminates some of the disadvantages of the above procedure. Thus, potassium salts of fatty acids can also be obtained, and soaps, in the end, contain less than 5% water. The major disadvantage is the accumulation of glycerin in the filtration solvent, the glycerin being impurified with the water contained in the alkali hydroxide solution and with sodium chloride used in the reaction, in order to increase the yield. Also, the soap obtained contains sodium chloride, glycerine and water, impurities that are sometimes undesirable.

Also known is a variant of this process, which describes the saponification of residual fat, extracted with the aid of a nonpolar hexane-like solvent, saponification being carried out in an aprotic dipolar solvent, such as acetone, in the presence of an aqueous hydroxide solution. 40% sodium (US 4259251).

The disadvantages are the same as in the procedure presented above.

Numerous methods of conditioning the soaps are known, in order to improve the properties, especially in the case of toilet soaps.

A classic additive process, to obtain a translucent toilet soap, proposes the pre-drying of the soap, in the form of granules. They are introduced in a special machine, called an amalgamator, where they are mixed with a paste made of polyethylene glycol, dye, perfume, etc., then homogenization is continued, in another specific machine, called refining plodder. The next steps of compaction and extrusion are completed, by cutting into pieces and pressing into molds, resulting in translucent toilet soap (US 4879063).

The major disadvantage of the process consists in the uneven distribution of some ingredients, in the form of paste, in the solid soap even under the conditions of the use of special mixing machines.

A procedure is known (RO111694), but which has the disadvantage of low purity.

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The technical problem, which the invention solves, consists in choosing an appropriate solvent system and establishing both the reports to the other reactants, in the two stages of the process, as well as the technical conditions and the succession of the operations, so as to obtain, with superior yields, a product of advanced purity and with an even distribution of ingredients. 50

The process according to the invention removes the disadvantages mentioned above, in that in the first stage triglycerides of the type of fats of vegetable or animal origin, in natural state, purified or recovered, as such or hydrogenated, chosen from the sunflower oils as such or epoxidized, soy as either epoxidized, rapeseed, olive, castor, flax, cotton, peanuts, pumpkin, corn germs, tall, cocoa butter, 55 palm, coconut, palm kernels, pork lard, fish, fats of equarisage, bovine serum, sheep, or mixtures thereof, are treated at 65, .. 67 ° C, for 0.5 ... 1 h, with methanol taken in a proportion of 16-21% by weight of triglycerides and with a hydroxide selected from sodium, potassium, lithium, barium hydroxide, or mixtures thereof, taken in a proportion of 0.5-4% by weight relative to methanol, in the presence of 60 bleaching mixture consisting of bleaching earth and activated carbon in a ratio of 4: 1 by weight, a mixture taken in a proportion of 4-6% by weight with respect to triglycerides, the bleaching mixture is separated by filtration, and the filtrate is decanted into two layers, of which the lower one rich in glycerin is purified and purified. valorizes, while the upper layer is saponified in the second step, in the presence of the same hydroxide taken in the molar ratio of 3: 1 to 65 triglycerides, of an antioxidant chosen from t-butyl-hydroxytoluene (BHT), t-butyl-hydroxy -anisole (BHA), t-butyl hydroquinone (BHQ), 2,6-d / T? -butyl-4-methylphenol, or mixtures thereof, taken from 0.02 ... 0.06% by weight with respect to the azeotropic mixture and an azeotropic mixture of methanol and a solvent selected from benzene, toluene, C5-C8 aliphatic hydrocarbons, cyclohexane, methyl, 1,2-dichloroethane, 1,2-dichloroethylene, acetone, acetonitrile, 70 ethanol, propanol-1, propanol-2, butanol-1,2-methylpropanol-1, a mixture used in a proportion of 250 ... 500% by weight relative to triglycerides, the reaction is heated to reflux for 2 to 3 hours, then treated with the conditioning ingredients, used alone or in combination, and which are selected from fatty acid alkanolamides, polyethylene glycols, glycerine, oil of olive oil, coconut butter, ethylenediaminetetraacetic acid 75 (EDTAJ, titanium dioxide, lanolin, rosin, dye, perfume, after which the soap is cooled, filtered and dried, and the azeotropic filtrate and mixture resulting from drying are reused in the process. .

The invention has the following advantages:

- high quality, anhydrous, non-alkaline soaps are obtained, without 80 inorganic salts and glycerin;

- result soaps protected evenly, against oxidation and additives with a uniform distribution of ingredients;

- no waste water results;

- Glycerin is easily separated from the anhydrous and high concentration, being able to purify 8 5 with reduced consumption of materials and energy, being subsequently used;

- ensures the reduction of the consumption of raw materials under the conditions of reuse of the filtrate and the azeotropic mixture of methanol with solvent resulting from drying;

- ensures the reduction of energy consumption, by using methanol and the azeotropic methanol-solvent mixture, which have relatively low boiling temperatures and 90 latent steam temperatures;

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The following are five examples of the invention:

Example 1. In a 5OO ml vessel fitted with stirring, thermometer and condenser, 41 g methanol and 0.2 g solid sodium hydroxide are introduced. After dissolving the hydroxide in methanol, 2DO g of coconut butter is introduced into the vessel, having the saponification index 242 mg KOH / g and 8 g of a bleached earth mixture, with activated carbon, at a gravimetric ratio of 4: 1. Warm the reaction mass, keeping to

65 ... 67 ° C, for 30 min. The bleaching mixture is removed by filtration and the filtrate is decanted into two layers: the lower layer (36 g), consisting mostly of glycerine, is removed, subsequently purified and recovered. The top layer is subjected to final saponification by introduction into a 1-vessel. , 5 L with stirring, thermometer and condenser, over a solution of 34.5 g sodium hydroxide and 0.12 g t-butylhydroxytoluene (BHT) in 600 g azeotropic mixture. The mixture consists of 192 g methanol and 408 g 1,2-dichloroethane, the composition of which corresponds to an azeotropic mixture that the two solvents would form in distillation.The respective mixture can be fresh and / or recovered from the previous batches (filtered plus solvent recovered from drying). maintaining the reaction mass at reflux (61 ... 63 ° C], for 2 h. After cooling, a precipitate is obtained which is easily filtered. The soap is dried, the filtrate and the azeot mixture are mixed. clothes, obtained from drying, can be used in subsequent batches.

203.5 g soap flakes, 98% yield.

Example 2. 33.5 g of methanol and 1.1 g of sodium hydroxide are introduced into a 500 ml flask fitted with a stirrer, thermometer and condenser. After dissolving the hydroxide, 200 g of pork lard, with a saponification index of 196 mg KOH / g and 12 g of bleached earth with activated carbon, in a gravimetric ratio of 4: 1, is introduced into the vessel. The reaction mass is heated under stirring, maintaining at

65 ... 67 ° C, for 1 hour. The bleaching mixture is removed by filtration and the reaction mass separated, by decanting into two layers. The lower weight layer of 34 g with a majority of glycerin content is removed for purification and recovery of glycerin. The top layer is placed in a 1.5 L vessel with stirring, thermometer and condenser, over a solution of 28 g of sodium hydroxide and 0.5 g of t-butyl hydroxyanisole (BHA) in 800 g of solvent mixture. . The mixture comprises 240 g of methanol and 570 g of isopropyl alcohol, the ratio of the two solvents corresponding to the azeotropic mixture, which they would form at distillation. The mixture can be fresh and / or recovered from previous batches. The reaction mass is heated, held at reflux for 3 hours, then cooled to obtain a precipitate which is filtered very easily. The soap is dried, recovering the azeotropic mixture obtained in the drying process, which together with the filtrate can be reused in the process. The result is 198 g of soap flakes, with a 96% yield.

Example 3. In a 500 ml vessel, equipped with shaking, thermometer, and condenser, 37 g methanol and 0.2 g sodium hydroxide are introduced. After dissolving the hydroxide, a mixture of 100 g of coconut butter, with the saponification index 242 mgKOH / g and 100 g bovine serum, with the saponification index is introduced into the vessel.

193.5 mg KOH / g, then 10 g of a mixture of bleaching earth and activated carbon, at a gravimetric ratio of 4: 1. The reaction mass is heated to 65 ... 67 ° C for 1 h. The bleaching mixture is removed by filtration, and the filtrate is decanted into two layers: the lower layer by weight of 35 g, consisting of glycerin.

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140 crude, is removed, for purification and recovery. The upper layer is transferred to the final saponification in a 1.5 l vessel provided with mechanical stirring, thermometer and condenser. In this vessel, a solution consisting of 28 g of sodium hydroxide, 4.5 g of potassium hydroxide and 0.4 g of BHT is introduced into a solvent mixture consisting of 412 g of methanol and 388 g of n-heptane, the mixture being fresh. and / or recovered from previous batches. Warm up, maintaining at reflux (60-62 ° C) the reaction mass for 3 hours. 15 g of conditioning ingredients selected from: fatty acid alkanolamides, polyethylene glycols, glycerine, olive oil, coconut butter, ethylenediaminetetraacetic acid (EDTA), titanium dioxide, lanolin, rosin, dye, perfume. The reaction mass is cooled under stirring, resulting in a precipitate that has evenly incorporated the conditioning ingredients and is easily filtered. The product was dried, recovering the azeotropic mixture of solvents.

The result is 206 g of additive soap flakes, with a yield of 97%.

Example 4. In a 500 ml beaker fitted with stirring, thermometer and condenser, 1.3 g of anhydrous barium hydroxide is suspended in 32 g of methanol. Introduce 200 g of crude sunflower oil with the saponification index 187.4 mg KOH / g and the acidity index 3.23 mg KOH / g, then 10 g of a mixture of bleaching earth and activated carbon at a gravimetric ratio of 4 :1. The reaction mass is heated to 65 ... 67 ° C for 1 h. The bleaching mixture is removed by filtration, and the filtrate is decanted into two layers: the lower layer (27 g), consisting of crude glycerine, is recovered after a prior purification The upper layer is subjected to final saponification, in a 1.5 L vessel, with shaking and condenser, where it is treated with 57 g anhydrous barium hydroxide suspended in 1000 g solvent mixture. The mixture consists of 600 g methanol and 400 g isobutyl alcohol. Heat, maintaining the reaction mass at reflux (1O3 ... 1O4 ° C), for 2 hours. Cool, precipitate is filtered, then dried, the azeotropic methanol mixture is recovered. -isobutyl alcohol.

The result is 229 g of barium soap with 97% yield.

Example 5. Follow the procedures described in Examples 1 ... 4, replacing the coconut butter, respectively pig fat, bovine sole or crude sunflower oil, with natural or purified triglycerides of plant or animal origin. or recovered, as such or hydrogenated, selected from epoxidized sunflower oils, soybean oils as such or epoxidized, rapeseed, olive, castor, hemp, cotton, peanuts, pumpkin, corn germs, tall, cocoa butter, palm, palm kernels, fish lard, squash fat, sheep fat, or mixtures thereof, making corrections required by fat quality.

Also, sodium hydroxide, respectively barium, can be replaced with potassium or lithium hydroxide, as such or as a mixture.

The mixture of solvents of the methanol-1,2-dichloromethane type, methanol-isopropyl alcohol, methanol-n-heptane, methanol-isobutyl alcohol, may be replaced by mixtures of methanol with: benzene, toluene, C5-C8 aliphatic hydrocarbons, methyl, 1,2-dichlorethylene, cyclohexane, acetone, acetonitrile, propanol-1, butanol-1, provided that the ratio of methanol to solvent is that corresponding to the azeotropic mixture which they would form at distillation.

Antioxidants such as t-butyl hydroxytoluene (BHT) and t-butylhydroxyanisole (BHA) may be replaced by t-butyl hydroquinone (BHQ), 2,6-di-t-butyl-4-methylphenol, or mixtures of them.

The result is soap flakes with 94 ... 98% yields.

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Claims (6)

claims 1. Process for obtaining fatty acid salts, from triglycerides in solvents, by treating triglycerides with a hydroxide, cooling, filtering, drying and conditioning the resulting fatty acid salts, characterized in that, in the first step, triglycerides are treated at 65. .67 ° C, for 0.5 ... 1 h, with methanol taken in a proportion of 16 ... 21% by weight compared to triglycerides and with a hydroxide taken in a proportion of 0.5 ... 4% in weight compared to methanol, in the presence of a bleaching mixture consisting of bleaching earth and activated charcoal in a ratio of 4: 1 by weight, a mixture taken in a proportion of 4 ... 6% by weight compared to triglycerides, the bleaching mixture is separated by filtration, and the filtrate is decanted into two layers, of which the lower one, rich in glycerin, is purified and valorized, while the upper layer is saponified in the second stage, in the presence of the same hydroxide taken at a molar ratio of 3: 1 compared to tri glycerides, of an antioxidant ratio of 0.02 ... 0.06% by weight compared to the azeotropic mixture and of an azeotropic mixture consisting of methanol and a solvent, a mixture used in a proportion of 250 ... 500% by weight compared to triglycerides, the reaction mass is heated to reflux for 2 to 3 hours, then treated with the conditioning ingredients, after which it is cooled, filtered and dried. Process according to Claim 1, characterized in that the triglycerides are of the type of fats of plant or animal origin, in the natural state, purified or recovered, as such or hydrogenated, chosen from the sunflower oils as such or epoxidized, soy as such or epoxy, rapeseed, olive, castor, hemp, cotton, peanuts, pumpkin, corn germs, tall, cocoa butter, palm, coconut, palm kernels, pork lard, fish, greasy fat, bovine, sheep, or mixtures thereof. Process according to Claim 1, characterized in that the hydroxide is selected from sodium, potassium, lithium, barium hydroxide, or mixtures thereof. 4. The process according to claim 1, characterized in that the antioxidant is selected from t-butyl hydroxytoluene (BHT), t-butyl hydroxyanisole (BHA), t-butyl hydroquinone (BHQ), 2,6-cf / -t. -butyl-4-methylphenol, or mixtures thereof. 5. Process according to claim 1, characterized in that the solvent is selected from benzene, toluene, C5-C8 aliphatic hydrocarbons, cyclohexane, methyl, 1,2-dichloroethane, 1,2-dichlorethylene, acetone, acetonitrile, ethanol, propanol-1, propanol -2, butanol 1,2-methylpropanol-1. 6. Process according to claim 1, characterized in that the conditioning ingredients are selected from fatty acid alkanolamides, polyethylene glycols, glycerin, olive oil, coconut butter, ethylenediaminetetraacetic acid (EDTA), titanium dioxide, lanolin, rosin, dye, perfume.