CS263749B1 - Process for preparing cationactive tenside - Google Patents

Abstract

The solution relates to cationic production a surfactant containing 1 to 85% by weight quaternary ammonium salts of formula I wherein R is alkyl of the number carbon atoms 8 to 22 being prepared by reacting 1 mole of aliphatic carboxylic acid acid of average molecular weight 144 to 340 with 0.8 to 1.4 moles of diethylaminoethanol at 60 to 190 ° C ·, whereupon the diethylaminoester formed is quaternized 0.8 to 1.4 moles of dimethyl sulfate at a temperature of 40 to 100 ° C, the nature of which is it is that at the beginning of the reaction adding 0.05 to 5 moles of organic solvent, which form with azeotropic water a mixture, preferably benzene, toluene, cyclohexane, chloroform or carbon tetrachloride.

Description

(54)

A process for preparing a cationic surfactant

The present invention relates to the preparation of a cationic surfactant containing from 1 to 85% by weight of a quaternary ammonium salt of the general formula (I) in which R represents an alkyl having a carbon number of 8 to 22 prepared by reaction of 1 mole of an aliphatic carboxylic acid. 0.8 to 1.4 moles of diethylaminoethanol at a temperature of 60 to 190 [deg.] C., whereupon the resulting diethylamino ester is quaternized with 0.8 to 1.4 moles of dimethyl sulfate at a temperature of 40 to 100 [deg.] C. of the organic solvent which forms an azeotropic mixture with water, preferably benzene, toluene, cyclohexane, chloroform or carbon tetrachloride, is added to the reaction.

in ₂ h » ₊

R-C00CH ₂ CH ₂ -N-CH,

Oh ₂ h ₅

CH-jOSO-j

263 749

The present invention relates to a process for the preparation of a cationic surfactant which comprises reacting an aliphatic carboxylic acid with a dialkylaminoalkanol in the presence of a solvent which forms an azeotropic mixture with water, and then the dialkylamino ester formed is quaternized with dialkyl sulfate.

Commercial fabric softeners usually contain a cationic surfactant, i.e., a quaternary ammonium salt, as the main active ingredient. Commonly used alkyltrimethylammonium compounds have very good antistatic activity, but their fabric softening effect is low. Quaternary salts having two alkyl chains with a higher number of carbon atoms have a slightly better softening effect. However, these compounds have low solubility in water and are used in the form of aqueous dispersions, but in the higher concentration are in the form of a gel. In addition, for the production of the abovementioned quaternary salts, primary amines are required as starting materials which need to be further alkylated. For the production of quaternary salts containing two alkyl chains, dialkylamines are required and also need to be further alkylated. These raw materials are not available in the Czech Republic. In addition, these quaternary salts are relatively poorly biodegradable.

The above disadvantages are solved by a method of producing cationic surfactant containing 1-85% by weight of quaternary ammonium salt of the formula I,? R 2 ^H 5 COOCH ₂ CH ₂ -N ⁺ -CH ₃ C ₂ H ₅ CH oso ^ ^ wherein R is alkyl having a carbon number of 8 to 22, prepared by reacting 1 mole of an aliphatic carboxylic acid having an average molecular weight of 144 to 340 with 0.8 to

- ··; and

1.4 moles of diethylaminoethanol at a temperature of 60 to 190 ° C, and the resulting diethylamino ester is quaternized with 0.8 to 1.4 moles of dimethyl sulfate at a temperature of 40 to 100 ° C by adding 0.05 at the beginning of the reaction. up to 5 moles of organic solvent which form an azeotropic mixture with water, preferably benzene, toluene, oyclohexane, chloroform or carbon tetrachloride, and the resulting diethylamino ester is quaternized with 0.8 to 1.4 moles of dimethyl sulfate at a temperature of 40 to 100 ° C.

An advantage of the inventive process for the cationic surfactant is that fabric softeners from the cationic surfactant thus prepared have a high antistatic and softening effect. The advantage of utilizing the addition of an organic solvent which forms an azeotropic mixture with water is that a high degree of conversion of the fatty acid to the ester is achieved, i.e. an acid number of 1 to 5 mg KOH ^/ g, corresponding to a conversion greater than 98%. Since the final product contains a minimal amount of the starting fatty acid, it is clear water soluble and can therefore be used in clear fabric conditioners which can also be applied in the form of sprays. If no organic solvent is used, the cationic surfactant has a pasty appearance and cannot be applied to clear fabric conditioners. A further advantage of the cationic surfactant of the invention is that it can be used in concentrated fabric softeners because of its low viscosity. It is also an advantage that since the cationic surfactant prepared by the process of the invention contains an ester bond, it is more readily biodegradable and less toxic than the alkyltrimethylammonium and dialkyldimethylammonium salts. Another non-negligible advantage is that the raw materials needed to produce the cationic surfactant according to the invention are available domestically. A commercially available process equipment is sufficient to produce the cationic surfactant of the present invention. The cationic surfactant produced by the process according to the invention can be equivalently replaced by imported cationic surfactants.

The starting aliphatic carboxylic acids may be either

263 7 * 9 pure, eg lauric, or it can be technical mixtures eg stearin (mixture of stearic acid and palmitic acid) or hydrogenated rapeseed acid.

The process for preparing the cationic surfactant of the present invention is illustrated in more detail in the following examples.

Example 1

The 600 L stainless steel reactor was charged with 256 parts by weight (1 kmol) of palmitic acid, 107 parts by weight (1.05 kmol) of Ν, Ν-dimethylaminoethanol and 18 parts by weight (0.2 kmol) of toluene. The mixture was heated to 150 ° C with stirring while distilling off the azeotropic toluene-water mixture. After the acid number drops below 5, the reaction mixture is transferred to a 1200 L reactor, 330 parts by weight of water are added and quaternized at 60 ° C with 120 parts by weight (0.95 kmol) of dimethyl sulfate. After addition of dimethyl sulfate, 730 pbw of water was added and the mixture was stirred at 70 ° C for 1 h.

The cationic surfactant, the dominant component of which is N-methyl-N, N-diethyl-N- (2-palmitoyloxyethyl) araonium methosulfate, is used to prepare highly effective fabric softeners.

Example 2

In the same manner as Example 1, instead of palmitic acid, 200 parts by weight (1 kmol) of coconut acid is reacted with 107 parts by weight (1.05 kmol) of Ν, Ν-dimethylaminoethanol in the presence of 84 parts by weight (1 kmol) of cyclohexane. The temperature is raised to 120 ° C with distillation of the cyclohexane-water azeotropic mixture until the acid number of the mixture falls below 5. 300 parts by weight of water are added to the ester ester formed and after stirring the reaction mixture is quaternized at 70 ° C with 107 parts by weight (0.85). kmol) dimethyl sulfate.

Cationic surfactant with a concentration of 50% by weight of the active substance is suitable for antistatic treatment of textiles.

263 TM

Example 3

According to the procedure of Example 1, 275 parts by weight (1 kmol) of rapeseed oil were reacted with 141 parts by weight (1.2 kmol) of benzene. The temperature is raised to 130 ° C while distilling the azeotropic benzene-water mixture. After the acid number of the reaction mixture falls below 5, 300 parts by weight of water are added to the resulting esteramine and quaternized with 126 parts by weight (1 kmol) of dimethyl sulfate at 80 °.

The surfactant is intended for the production of fabric softeners with antistatic and softening effect.

Claims (1)

SUBJECT OF THE INVENTION Process for producing cationic surfactant containing 1-85% by weight of quaternary ammonium salt of general formula I, C ₂ ^H 5 R ₂ COOCH ₂ CH ₃ -N ⁺ -CH ₃ oso CH ₃ wherein R is alkyl of carbon number 8-22, which is prepared by reacting 1 mole of an aliphatic carboxylic acid having an average molecular weight of 144 to 340 with 0.8 to 2.0 1.4 moles of diethylaminoethattol at 60 to 190 ° C, and the resulting diethylamino ester is quaternized with 0.8 to 1.4 moles of dimethyl sulfate at 40 to 100 ° C, characterized in that at the beginning of the reaction, 0.05 to 5 moles of organic solvents which form an azeotropic mixture with water, preferably benzene, toluene, cyclohexane, chloroform or the like. tetrachloride * methane.