CS258792B1 - Process for preparing a mixture of ampholytic surfactants - Google Patents

Abstract

The solution relates to a method for producing a mixture of ampholytic surfactants of general formulas I and II, in which R3 denotes alkyl with a number of carbon atoms of 8 to 22, R3 alkyl with a number of carbon atoms of 1 to 5, from amines of general formulas I to II, the essence of which is that the amine is first added to a solution of sodium chloroacetate at a temperature of 30 to 90 °C, after which hydrogen peroxide is added. The resulting mixture of ampholytic surfactants is suitable for use in hair shampoos, bath foams, intimate hygiene products, liquid soaps and dishwashing products.

Description

The invention relates to the preparation of a mixture of surfactants with tertiary amines, sodium chloroacetate and hydrogen peroxide.

The resulting mixture of ampholytic surfactants, betaine and amine oxide is suitable for use in hair shampoos, bath foams, intimate hygiene products, liquid soaps and dishwashing detergents.

The general formulations of the above formulations consist of a mixture of ampholytic surfactants and anionic surfactant. The betaine-amine oxide ratio is dependent upon the use of the composition.

For hair shampoos, a betaine amine oxide ratio of 2: 1 to 1: 1 is generally used, with betaine and amine oxide acting as a conditioning agent with an antistatic effect. Detergents typically use 10-15% ampholytes and 20% anionic surfactants at a betaine-amine oxide ratio of 1: 1. In the production of betaine, the tertiary amine is reacted with a sodium chloroacetate solution and the betaine formed is bleached by the addition of 0.5 to 1% hydrogen peroxide.

The reaction of the tertiary amine with sodium chloroacetate in a stoichiometric ratio does not fully react with sodium chloroacetate and 0.1 to 0.2% of covalently bonded chlorine remains in the final solution, corresponding to the remainder of 0.2 to 0.5% of chloroic acid. Chloroacetic acid in the cell deteriorates the dermatological properties of the product and increases its toxicity. To prepare the amine oxides, the tertiary amine is reacted with a 30% aqueous hydrogen peroxide solution.

During the reaction, the viscosity of the reaction mixture increases rapidly, a conventional stirrer is not enough and an organic solvent such as ethanol must be added to stir the resulting mixture.

The amine oxide solution then contains an organic solvent, which in some cases may be a malfunction.

The above-mentioned disadvantages have no process for the preparation of a mixture of ampholytic surfactants of the general formulas

R -CONH- (CH ₂ ) ₃ -N-CH ₂ COO

AND

R -CONH- _(CH2) jN * · O (I) (II)

2 wherein R is an alkyl of 8 to 22 carbon atoms, R is an alkyl of 1 to 5 carbon atoms from amines of formula (I)

R -CONH- (CH3) - N (III)

Wherein R and R are as defined above, characterized in that 1 mole of the amine of the general formula is present. III is added to a solution of 0.10 to 0.80 moles of sodium chloroacetate at a temperature of 30 to 90 ° C, followed by 0.05 to 0.95 moles of hydrogen peroxide.

An advantage of the process for preparing a mixture of ampholytic surfactants of formulas I and II is that the mixture contains no covalently bonded chlorine and that the viscosity of the reaction mixture does not increase during the reaction.

Liquid personal care products and liquid soaps are mainly based on ampholytic surfactants, which are used to prevent skin damage and have a disinfectant effect. To adjust the viscosity of the product, the mixture of ampholytic surfactants can be mixed with anionic surfactants, e.g., sodium lauryl sulfate. When preparing detergents, it is usually a matter of dissolving surfactants in water, after which dyes, perfumes and other special additives are added.

According to the process of the invention, a mixture of the betaine of the formula I and the amine oxide of the formula II can be prepared in a ratio suitable for the purpose.

The following examples illustrate the process of preparing a mixture of ampholytic surfactants.

Examples

Example 1 o

117 kg of water are introduced into an enamel heated reactor with a useful volume of 1.5 m and 78 kg of chloroacetic acid are dissolved therein while stirring. After complete dissolution, 75 kg of a 10% aqueous sodium hydroxide solution is pumped in. The pH of the solution was adjusted to 6.5-7 by sequential addition of the sodium hydroxide solution and then 331 kg of tertiary amine prepared from 102 kg of 3-dimethylaminopropylamine and 257 kg of coconut oil were added. The tertiary amine is dosed for 2 hours while maintaining the temperature of the reaction mixture at 60 ° C. At 40 ° C, 28 kg of 30% ^H 2 O 2 is added ^{over 4} hours. 1,190 kg of surfactant mixture are obtained with an active substance content of% (of which 24% alkylamidobetaine and 6% amine oxide). The prepared composition serves as a surfactant base for the preparation of liquid soaps, shampoos or intimate hygiene products.

Example 2

According to the procedure of Example 1, to a solution of 42 kg of chloroacetic acid in 63 kg of water and 43 kg of 40% sodium hydroxide was added 307 kg of a tertiary amine prepared from 106 kg of 3-diethylaminopropylamine and 201 kg of palmkernel oil. Dosing of the tertiary amine takes 3 h, after which the unreacted amine is oxidized for 4 h with 55 kg of 30% hydrogen peroxide. The viscosity of the mixture is adjusted during the reaction by adding 524 kg of water. After stirring at 60 ° C for 4 hours, 1034 kg of a pale yellow solution with an active compound content of 30% (of which 15% alkylamidobetaine and 15% amine oxide) are obtained. The mixture is suitable for the preparation of body shampoos and dishwashing detergents.

Example 3

Following the procedure of Example 1, 40 kg of a 50% chloroacetic acid solution, 20 kg of 40% sodium hydroxide were added at 80 ° C to the tertiary amine prepared according to Example 1 (331 kg) and the mixture was stirred at 80 ° C for 2 h. Unreacted tertiary amine is then oxidized by addition of 100 kg of 30% hydrogen peroxide at 80 ° C and diluted with 586 kg of water. 1 075 kg of a slightly yellowish solution are obtained containing 30% of active substance (8% betaine and 24% amine oxide). The prepared surfactant mixture is particularly suitable for the preparation of hair shampoos.

Claims (1)

Preparation of a mixture of ampholytic surfactants of general formula R ² 1 < ₊ R -CONH- (CH ₂ ) ₃ -N-CH ₂ COO (I) R ¹ -CONH- (CH 2) n -N (O) ₂ R Where R is an alkyl having a carbon number of 8 to 22, R is an alkyl having a carbon number of 1 to 5 amines of the general formula _R 2 χ I R -CONH- (CH ₂ ) ₃ -N (III) Wherein R and R are as defined above, characterized in that 1 mole of amine (III) is added to a solution of 0.10 to 0.80 moles of sodium chloroacetate at a temperature of 30 to 90 ° C, followed by 0.20 to 0.95 mol of hydrogen peroxide.