DE2063422A1 - Process for the preparation of surfactant mixtures containing betaine and amine oxide - Google Patents

Description

DIPL-ING. PH. EYER

PATENT ADVOCATE
FRANKFURT A. M

D ι PL-1 ν α Ε. EYER

Patent attorney applicant:

Rewo Chemische Fabrik GmbH Steinau Krs. Schlttehtern

Process for the preparation of surfactant mixtures containing betaine and amine oxide

The invention relates to a method for producing surface-active Η-oxides in the presence of the same amphoteric surfactants derived from tertiary amines.

Both amphoteric and amine oxide surfactants have recently been used Time achieved greater importance in the field of detergents and personal care products. This is largely based on their excellent skin friendliness and their wide range of applications together with cationic and anionic surfactants.

Furthermore, these products show complete biodegradability and therefore do not cause any difficulties the treatment of wastewater.

For the production of these two body classes one starts from tertiary amines, which are both purely aliphatic as well as may be cyclical. By quaternizing with halogen carboxylic acids or sulfonic acids you get the desired beta

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inic surfactants. When treating the tertiary amines with hydrogen peroxide or similar oxidizing agents the corresponding amine oxides are formed.

The quaternization of the tertiary amines with the common ones However, halogen compounds do not proceed quantitatively in any case. Even under ideal conditions, for example lower reaction temperature and neutral pH by hydrolysis of the reactive halogen, undesired by-products, such as salts of hydroxycarboxylic or sulfonic acid, as well as metal halides. The following table and diagram show the degree of conversion to betaine as a function of the molar amount of chloroacetic acid added in the reaction with Dimethy11aurylamin, in aqueous solution at 55 ° C

Implementation graph ζ at _0etöin

4.0

CLCH ₂ COOH

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Mole
Dimethyllaurylaain Hol
Chloroacetic acid Degree of implementation
to betaine l _t o O.3 $ 28> Ι, ο 47 # l _f o o, 7 69 * Ι, ο Ι, ο 85 % It 1.3 87 # It ·. 1.6 90%

Since betaines are used as detergents and especially for skin and hair care, it is essential that the amine used is quaternized down to the slightest trace, since tertiary amines are strong bases that have a caustic and damaging effect on the skin one must use an excess of up to $ 2oo> of the quaternizing agent in order to remove residues of tertiary amine. This excess, however, leaves in the reaction mixture substantial amounts of electrolytes, which can only be removed with great difficulty and incompletely by redissolving. Such impurities often cause difficulties when using the betaines in mixtures with other surfactants. The high salt content leads to preparations that are not temperature-resistant, which become cloudy in salt storage and can even separate into different phases.

209830/1138

The applicant's aim was to find a process for the production of surface-active betaines which not only contained very small proportions of interfering electrolytic foreign substances, but are also characterized by a particularly low tertiary amine content, which is essential for the required skin tolerance.

It has now been found that in the presence of betaines tertiary amines smoothly and under mild conditions with peroxides, especially with hydrogen peroxide, can be converted into the corresponding iil oxides. N-oxides, like Betaines can be combined with both cationic and anionic surfactants, so that the mixture obtained here can be widely used. The absence of undesirable by-products of an electrolytic nature facilitate the formulation.

The betaine / U-oxide obtained can obviously be varied within wide limits and is generally between 3o: 7o up to 9o: lo. The lower the betaine content of the mixture, the lower the salt content will be. J-edoch remain open until a betaine content up to 85 i <> the salt content still so insignificant that he hardly negligible. When the H-oxide is formed from the remainder of the tertiary amine with hydrogen peroxide, there is an excess of 10% - 20%

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required to completely eliminate the tertiary amine "; this reaction only produces water as a by-product.

The invention is illustrated below by way of some examples explained.

Example Mr. 1 ,

47.3 kg of chloroacetic acid (0.5 kmol) are in 3o8.0 kg Dissolved water and placed in a kettle with a stirrer. The solution is made with 222.0 kg of technical-grade dimethyllaurylamine added (1 kmol). The mixture is stirred at 55 ° C. for 8 hours. The mixture is then heated to 90 ° 0 and left for a further 2 hours stir. An analysis of the approx. 47 # solution shows that 47 # of the dime thy11aury! amine is converted to betaine to have. The reaction mixture is now adjusted to a pH of 5-6 by adding acetic acid Mix carefully with 72, ο kg hydrogen peroxide ^ j (30 $ solution, 0.63 kmol) added. The mixture is stirred at 55 ° C. until there is no hydrogen peroxide in the reaction mixture can prove more. An analysis of the end product shows that over 99 # of the dimethyl aryl amine used have converted to ampholyte or N-oxide.

Example No. 2

66.1 kg of chloroacetic acid (0.7 kmol) are in 336.0 kg of water dissolved and placed in a kettle with a stirrer. The solution

222.0 kg of technical Dimethyllaury larain are added. 209830/1138

The mixture is stirred at 55 ° C. for 8 hours. The mixture is then heated to 90 ° C. and stirred for a further 2 hours. The analysis of the ca * yields 45 #igen solution because 13 69 $> of the amine Dimetbyllaury! Have converted to betaine · The Reaktionsmisohung is by adding vinegar »» acid to a pH value about 5-6 © readjusted. 40.0 kg of hydrogen peroxide (30% solution, 0.35 kmol) are carefully added to the mixture. The mixture is stirred at 55 ° C. until no more hydrogen peroxide can be detected in the reaction mixture have converted more than 99% of the dimethyllauryamine used to the ampholyte or-oxide.

Example ffr. 3

66.1 kg of chloroacetic acid (0.7 kmol) are dissolved in 300 _t © kg of water and placed in a kettle with a stirrer. The solution is admixed with 268.0 kg of 1: hydroxyethyl-2-layiryl-imidazoline (1 kmol). The mixture is stirred at 55 ° C. for 15 hours. The mixture is then heated to 90.degree. C. and heated for a further 2 hours. An analysis of the aqueous solution results in that $ 67 "have implemented the inserted l-Sydroxyäthyl-2-lauryl-betaine to Imldazolins ·

The reaction mixture is made up by adding acetic acid a pH of 5-6 is adjusted · The mixture is carefully treated with 45.4 kg of hydrogen peroxide (30% solution, 0.4 ksol) added · The mixture is stirred at 55 ° C until sioh

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no more hydrogen peroxide can be detected in the reaction mixture. An analysis of the end product shows that over 99 $> of the 1-hydroxyethyl-2-lauryl imidazolines used have been converted to the ampholyte or N-oxide.

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Claims (2)

2063A22 P a t e η t a Ii s ρ r Ii & h e: 1. Process for the preparation of surfactants U-oxides in the presence of the see of the same tertiary Amine-derived amphoteric surfactants, characterized by » that the tertiary amine with a corresponding precalculated amount of halocarboxylic acid or halosulfonic acid reacts to an arbitrarily determined proportion to form the ampholyte and the unreacted amine proportion the substance is then oxidized in Gregenwart of the ampholyte. 2. The method according to claim 1, characterized in that the substance containing ampholyte and tertiary amine at a temperature between 4o and 6o C, preferably at 55 ° C, with an oxidizing agent, preferably Hydrogen peroxide, in one on the content of tertiary amine calculated amount is implemented. 209830/113 8