CS246133B1 - Method of cationic tensides production - Google Patents

Abstract

The method addresses the production of important cationic ones surfactants which form the basic raw material for fabricating fabric softeners with a distinctive antistatic and softening effect. production is carried out without the use of solvents at temperatures from 40 to 90 ° C quaternary the corresponding amino esters of formula II wherein R 'is an alkyl radical of 7 to 19 O carbon atoms, R is an alkyl radical having 1 to 4 carbon atoms, dimethylsulfate or diethylsulfite, with a molar ratio of 0.49 to 1.00 mol per mole of amino esters II.

Description

(54) A method for producing cationic surfactants

The method solves the production of important cationic surfactants, which form the basic raw material for the production of fabric softeners with a significant antistatic and softening effect.

the process is carried out without the use of solvents at temperatures of from 40 to 90 DEG C. of the corresponding aminoesters of the formula II in which R @ 7 denotes an alkyl radical of 7 to 19 carbon atoms, R a C1 -C4 alkyl radical, dimethylsulphate or diethylsulphate; a molar ratio of 0.49 to 1.00 moles per 1 mol of aminoesters II.

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

Fabric softeners usually contain a quaternary ammonium salt as the main component. Structures commonly used in quaternary salts can be divided into two groups: a) dialkyldimethylammonium or alkyltrimethylammonium compounds, b) alkylimidazoline compounds. Substances of type a) have been used for the longest time and have been among the most widely used recently. Their production is quite complicated. The three-step amine synthesis (in fatty acid-amide-nitria sequence) requires pressurized hydrogenation equipment. The resulting primary amines are proportional to the cell secondary or reductively methylated to tertiary amines. Dialkylmethylammonium chlorides are prepared from secondary amines by reaction with methyl chloride in an alkaline medium, dialkyldimethylammonium methosulfate is produced from tertiary amines by quaternization with dimethyl sulfate.

The preparation of the alkylimidazoline compounds of type b) is based on an aliphatic carboxylic acid (optionally an ester) and N- (2-hydroxymethyl) ethylenediamine. However, the cyclization of the resulting intermediate takes place at temperatures in excess of 200 ° C. To produce the above cationic surfactants, complex equipment or high reaction temperatures are required.

The above disadvantages are solved by a process for the production of cationic surfactants of the general formula X:

R ¹ -COOCH ₂ -CH ₂ -N ⁺ -R ³ wherein R ³ is 4 carbon atoms, R ^{3 is} sulfonyl, from 7 to 19 carbon atoms, R is 1 to methyl or ethyl, X is methoxy sulfonyl, or ethoxyaminoesters of formula II,

R ¹ -e ¹⁰⁰ CH _o -CH _o -N ^{2 2} b

II

2. wherein R and R are as defined above, by reaction with dimethyl sulfate or diethyl sulfate, characterized in that a mixture of 1 mole of the aminoester of formula II and 5 to 80 moles of water is reacted with 0.49 to 1.00 moles of dimethylsulfate or diethylsulfate at temperature 40 to 90 C.

An advantage of the production method according to the invention is that it requires a simple device consisting of only one reaction boiler equipped with a stirrer and steam-heated.

The starting amino ester of formula (II) is prepared by reacting an aliphatic carboxylic acid with the corresponding amine. The reaction with an excess of the amine proceeds only up to a certain conversion of the aliphatic carboxylic acid (usually 85%), even with an excess of the amine. The amino ester of formula II is directly quaternized without further purification with dimethyl sulfate or diethyl sulfate.

The 11-molar amount of dimethyl sulfate added is of critical importance. If dimethyl sulfate is less than the molar ratio of the present invention, the unreacted aminoester remains in the reaction mixture. If the number of moles of dimethyl sulphate per 1 mol of aminoester II is greater than 1, unreacted dimethyl sulphate remains in the reaction mixture, which is then hydrolyzed to methyl sulfuric acid in an aqueous medium, thereby lowering the pH to 2 and rendering the feedstock unusable.

An advantage of the process according to the invention is that at the stated proportions of substances, it is not necessary to use organic solvents to achieve easy handling of the raw material. The surfactant produced in this way is not flammable, thus increasing the handling safety and the production does not need to be situated in the hall in an explosion-proof design. The process according to the invention thus means a simple preparation of cationic surfactants.

The prepared cationic surfactant is usually diluted with water to a concentration of 30 to 50% and bleached by the addition of hydrogen peroxide.

The production method is shown and explained in more detail in the following examples.

Example 1

284 kg of stearic acid are charged to a 600 L stainless steel reactor and after its melting 129 kg of dimethylaminoethanol is added. The mixture was stirred at 150 ° C for 6 hours. After the acid number drops below 20, the reaction mixture is transferred to a 1200 L stainless steel reactor, 500 kg of water are added, the reaction mixture is vigorously stirred, cooled to 90 ° C and 77 kg of dimethyl sulphate is added with stirring at a rate the temperature of the mixture did not exceed 85 ° C. After addition of dimethyl sulfate, 190 kg of water was added and the mixture was stirred at 60 ° C for 2 hours.

1150 kg of a 40% cationic surfactant are formed, the dominant component being Ν, Ν, Ν-triraethyl-N- (2-stearoyloxyethyl) ammonium methosulfate. The surfactant is used for the preparation of fabric softeners with excellent antistatic and softening effect.

Example 2

The reactor as in Example 1 was charged with 256 kg of palmitic acid, 107 kg of dimethylamino ethanol and stirred for 7 hours at 140 ° C under a nitrogen atmosphere. After completion of the reaction, the mixture was transferred to a 2000 L reactor, 327 kg of water was added and quaternized at 50 + 5 ° C with 123 kg of diethyl sulfate. After quaternization, the mixture was diluted with 738 kg of water and immediately bleached at 60 ° C with 1% hydrogen peroxide in conc. 30%.

30% cationic surfactant is used for antistatic treatment of textiles.

Example 3

In the same manner as in Example 1, instead of stearic acid, 200 kg of coconut acid was reacted with 107 kg of dimethylaminoethanol for 8 hours at 130 ° C. The resulting amino ester was added 300 kg of water and, after stirring at 80 quaternised ^e C. 101 kg of dimethylsulfate. It is then diluted with 72 kg of water and stirred at 70 ° C for 2 hours. 50% cationic surfactant is suitable for antistatic treatment of textiles.

Example 4

Following the procedure of Example 2, 275 kg of stearin was reacted with 141 kg of diethylaminoethanol at 150 ° C for 6 hours. After completion of the condensation, the mixture was diluted with 375 kg of water in a 1000 L reactor and quaternized at 55 ° C with 101 kg of dimethyl sulfate. 100 kg of water was added and the mixture was stirred for 1 hour. 950 kg of a 50% surfactant are obtained, the main component of which is Ν, Ν-diethyl R-methyl-N- (2-stearoyloxyethyl) ammonium methosulfate. The surfactant is a cold beige paste and is intended for the preparation of fabric softeners with a softening and antistatic effect.

Claims (1)

SUBJECT OF THE INVENTION A process for the preparation of catinonactive surfactants of the general formula I, R ² R ₂ .cooch .ch ₂ -i! I ^{+ -R3} X- 1 2. wherein R represents an alkyl radical having from 7 to 19 carbon atoms; 4 carbon atoms, R₁ methylakupinu or ethyl, or X methoxyaulfonylakupinu ethoxyeulfonylekupinu of aminoeateril Formula 11, R _'2 .cooch .ch ₂ .2 -i II Wherein R @ 1 and R @ 2 are as defined above, by reaction of dimethylaulfethene or diethylaulfethene, characterized in that 1 mole of the amyl ester of formula (II) and 5 to 80 moles of water is reacted with 0.49 to 1.00 moles of dimethylsulphate or 40 ° to 90 ° C.