CS258941B1 - Process for the production of cationic surfactants - Google Patents

Abstract

Process for the production of cationic surfactants which form the basic raw material for the production of concentrated fabric softeners. The quaternization of the amino amides of the polymeric carboxylic acids of formula (II) takes place at temperatures from 40 to 90 ° C using dimethyl sulfate or diethyl sulfate in a molar ratio of alkyl sulfate to aminoamide of 0.5 to 1.2 to 1.

Description

The invention relates to a process for the production of cationic surfactants which are intended as a raw material for the preparation of fabric softeners having an excellent antistatic and softening effect on textiles.

Commercial fabric softeners usually contain a quaternary ammonium salt as the dominant active ingredient. Commonly used alkyltrimethylammonium compounds exhibit very good antistatic activity, but their softening effect is low. The introduction of a second long alkyl chain into the molecule greatly improves the softening effect. These compounds have low solubility in water and are used in the form of aqueous dispersions, which at higher concentrations of ammonium compounds take the form of a gel. These compounds are therefore unsuitable for the preparation of highly concentrated fabric softeners. Both desirable properties (2 alkyl chains per molecule while maintaining good water solubility) associate diquaternary compounds with two long alkyl chains per molecule. Commonly used diquaternary compounds are bi-imidazoline compounds (U. S. P. 3, 855, 235) or oxyethylated ethylenediamine-based compounds. However, the preparation of imidazoline compounds is energy intensive, since the cyclization of the reaction intermediate takes place at temperatures of 200 to 250 ° C.

The above disadvantages are solved by a process for the preparation of cationic surfactants of the general formula I

CONH (CH ₂ ) _n mX where

R is an alkyl radical of a polymeric carboxylic acid of 20 to 60 carbon atoms

R 1 is C 1 -C 4 alkyl

R is C 1 -C 2 alkyl

X a methoxy-sulfonyloxy or ethoxy-sulfonyloxy group m a natural number of 2 to 3 n a natural number of 1 to 4 of the amide of the formula II

COHN (CH ₂ ) _n -N

II in which

R, n and m are as defined above, characterized in that a mixture of 1 mole of the amide of the formula II is reacted in an aqueous or alcoholic medium with 0.5 to 1.2 mol of dimethyl or diethyl sulfate at a temperature of 40 to 90 ° C

The starting amide is prepared by reacting a dimeric or a trimeric aliphatic carboxylic acid or a mixture thereof with the corresponding amine.

The prepared surfactant is diluted with water to a concentration of 25 to 50 Ϊ, or bleached with hydrogen peroxide.

The production method is shown in the following examples.

Example 1

A 800 L stainless steel reactor was charged with 564 kg of dimeric oleic acid and 112 kg of Ν, Ν-dimethyl-propylenediamine was added with stirring at 50 ° C. The mixture was stirred at 150 ° C for 6 hours. After the acid number has dropped below 15, the reaction mixture is transferred to a 2500 L stainless steel reactor, 640 kg of water are added, and with stirring at 50 ° C 147 kg of diethyl sulfate are added over 1 h at such a rate that the temperature of the mixture does not exceed 80 ° C. Upon completion of the diethyl sulfate dosing, 150 kg of water are added and the mixture is stirred at 40-50 ° C for 2 hours. This results in 1,560 kg of a 50% surfactant which is used for the manufacture of fabric softeners.

Example 2

According to the procedure of Example 1, 423 kg of trimeric oleic acid was reacted with 161 kg of N, N-dimethyl propylenediamine for 4 hours at 170 ° C. After the amidation was complete, the mixture was diluted with 500 L of water in a 1200 L reactor and quaternized with 172 kg of dimethyl sulfate at 50 ° C. 1150 kg of water are added and the mixture is stirred for 1 hour at 40-50 ° C. 30% cationic surfactant is used for antistatic treatment of textiles.

Example 3

According to the procedure of Example 1, 687 kg of a mixture of dimeric and trimeric oleic acid (23% dimer, 77% trimmer) was reacted with 226 kg of dimethylethylenediamine at 160 ° C for 6 hours. + 5 ° C 258 kg of dimethyl sulfate. Cationic surfactant with a concentration of 75% is used in antistatic treatment of textiles.

Claims (1)

OBJECT OF THE INVENTION Formula I, A method for producing cationic surfactants both R ¹ CONH (CH ₂ ) _n - N ⁺ - R ² mX 1 m where R is an alkyl radical of a polymeric carboxylic acid having from 20 to 60 carbon atoms; C 1 -C 4 alkyl R is methyl or ethyl X a methoxy-sulfonyloxy or ethoxy-sulfonyloxy group n the natural number 1 to 4 m the natural number 2 to 3 of the amide of the formula II COHN (CH ₂ ) -N II having the above meaning by reacting with dimethyl sulfate or diethyl sulfate, the mixture of 1 mole of the amide of formula II is reacted with 0.5 to 1.2 mol of dimethyl diethyl sulfate in a water or lower alcohol or polyol environment at a temperature where R, r 1, as measured by sulfate or 40 to 90 ° C.