DD219023A3 - PROCESS FOR THE PRODUCTION OF SODIUM TAURINATE - Google Patents

Abstract

Process for the preparation of sodium taurinate by reaction of sodium isethionate with ammonia in the presence of neutral and strongly alkaline electrolytes. By adding 0.03 to 0.5% of alkanediols to the mixture of the starting materials and simultaneously limiting the content of neutral electrolyte to a maximum of 0.1%, the formation of the undesirable by-products di- and tritaurinate is significantly inhibited, resulting in a decrease in their Share in the synthesis product from normally 37% to about 30% expresses. This results in a reduction of the specific material use to 90% for sodium isethionate and 95% for ammonia. The increased proportion of sodium taurinate and the only insignificant content of neutral electrolytes make it possible to use the synthesis product directly after removal of the excess ammonia for the production of fatty acid condensation products. On the only possible with great effort possible isolation of taurine can be dispensed with.

Description

, VEB Leuna-Werke Leuna

HWaIter Ulbricht H

LP 8245. '

Title of the invention. ,

Process for the preparation of sodium taurinate Field of application of the invention

The invention relates to a process for the preparation of sodium taurinate by reaction of sodium isethionate with ammonia. "Hatriumtäurinat is mainly for the preparation of Lettsaeurekondensationsprodukten, an important class of anionic surfactants, required.

Characteristic of the known technical solutions

It is known to prepare sodium taurinate by reacting sodium isethionate with ammonia in an aqueous solution at temperatures of 423 to 553 K (DRP 593968).

To increase the reaction rate, it is expedient to use electrolysis which reacts neutrally or alkaline (DRP 612994, DL-PS 84394).

The ammonia is used in greater molar excess of from 10: 1 to 20: 1 to avoid the undesirable formation of iminobisethanesulfonate (ditaurinate) and of nitrile tris-ethane sulfonate.

13AÜ & 1932 * 029Ü09

to restrict fonate (tritaurinate). Nevertheless, it is unavoidable that these byproducts are contained in an amount of about 37 % by weight in the anhydrous reaction product, if, for example, a MoI ratio of ammonia: sodium isethionate of 15: 1 is assumed.

The formation of significant amounts of di- and tritaurinate is very disadvantageous, because it makes an increased use of materials necessary and the economics of the process "unfavorably influenced. It is also from Lachteil that these by-products in the subsequent implementation of the ITatrium ^v -. taurinates remain with acyl chlorides as fiber in the resulting Pettsaeurekondensationsprodukt. and its active ingredient content decrease. Also as ballast, the additional contamination of the .Hatriumtaurinates acts by the supplied neutral electrolytes; the alkaline electrolyte ^. however, do not bother. '' ^: .

For separating the di- and Tritaurinates and inorganic electrolytes, methods have been developed ', after which the <latriumtäurinat by treatment mit'einer Ionenaustauscherkombination (U.S. Patent 2,693,488) or by addition of acids - (DT-PS 1,122,540 and 1,157,234) in iaurin transferred and \ is closing recovered in multistep processes as a pure internal salt on / ~. All these processes have the disadvantage of a very high need for acids and alkalis and cause considerable costs.

Object of the invention ^x , ₍

The aim of the invention is sodium taurinate by reaction of sodium isethionat with ammonia in higher yield and with improved. Gaining purity and making the process more economical. ,

Explanation of the essence of the invention

Per the invention, the task was to "basically to find a method of limiting the side reactions in the llatriumtsurinatherstellurig so while maintaining the standard technical Ammoniakueberschuases reaction products with a di- and Tritaurinatgehalt of less than 37 weight percent solids arise that without additional purification steps can be further processed. This object is achieved by the fact that in the reaction of sodium isethionate with ammonia in the presence of electrolytes according to the invention in the mixture of the reactants 0.03 to 0.5 mass% alkanediols and at most 0.1 mass% neutral electrolytes are included.

Particularly suitable alkanediols in the context of the invention are ethylene glycol and 1,2-propanediol. Als.neutrale Elektrolyt ^ come, inorganic salts, such as. sodium sulfate, sodium sulfite, sodium chloride and disodium phosphate into consideration;

The process according to the invention is carried out at a temperature of 473 to 563 K with a molar ratio of ammonia: sodium isethionate of 10: 1 to 20: 1 in the liquid phase, with pressures of up to 15 MPa. The reaction time is 5 to 40 minutes, depending on the composition and concentration of the inorganic electrolysis in the starting solution. The alkaline electrolytes advantageously consist of alkali metal or alkaline earth metal hydroxides in a concentration of 0.1 to 1 lol / l.

 jg 7_84-01 8 & 35ϋ

A particular advantage of the process according to the invention is the reduction of the IT by-product content in the sodium taurinate to values of about 30 % (when using a molar ratio of ammonia: sodium isethionate of 15: 1). At the same time compared to known methods of specific material use of sodium isethionate can be reduced to 90 % and ammonia to 95 % . The low content of the synthesis product of alkanediols does not interfere with the further processing by reaction with acyl chlorides,

Exemplary embodiments. '

' ι

Example 1 ^

A mixture of 650 parts of a 46% aqueous urea isethionate solution and 2070 parts of a 25% ammonia solution was added together with 17 parts of sodium hydroxide. "3.5 parts of ethylene glycol and 2.0 parts of sodium sulfate in an autoclave heated for 45 idin to a temperature of 533 K. In this case, almost complete conversion of the sodium isethionates a reaction product of 203 parts of tetrasodium (71 %) and 83 parts di- and Tritaurinat to (29%) The anhydrous reaction product contained 1.1% and 0.6% Sthylenglykol sodium ^sulfate..;

If the reaction was carried out under otherwise identical conditions but without addition of ethylene glycol and with an amount of 18 g of sodium sulfate, then, in addition to 182 parts of sodium taurinate (6.4 %), 102 parts of di- and tritaurinate (36%) were also obtained the anhydrous reaction product was contaminated by 5.5% sodium sulfate. '

Example 2., ^:

A 538 K heated tubular reactor with a volume of. 1,000 parts by volume became 4000 parts by volume

a pre-heated to the same temperature mixture of 650 parts of 46% aqueous sodium isethionatloesung, 2070 parts of 25% ammonia solution, 44 parts of sodium hydroxide, 4 parts of ethylene glycol and 1.5 parts of sodium sulfate zugefuehrt. Almost complete conversion of the sodium ethionate yielded a reaction product containing, in addition to 278 parts of sodium taurinate (69%), 124.5 parts of di- and tritaurinate (31 %) per hour. Y / eitere '. Ingredients in the anhydrous product were 1.2 % ethylene glycol and 0.4% sodium sulfate. -

When the reaction was carried out under otherwise identical conditions but without addition of ethylene glycol and with an amount of 22 parts of sodium sulfate, the reaction product contained 251 parts of sodium taurinate (63 %) and 147 parts of di- and tritaurinate (37 %). the anhydrous product is contaminated by 6.2 % of Sodium Sulphate.. ,. '

Example 3 '. '

3500 parts by volume of a preheated mixture of 650 parts of 46% aqueous sodium isethionate solution, 2070 parts of 25% ammonia solution, 44 parts of sodium hydroxide, 7 parts of 1,2-propanediol and 1.5 parts of sodium peroxide were fed to the reactor mentioned in Example 2 "In nearly complete conversion of the sodium ethethionatea, 239 parts of sodium taurinate (68 %) and 112.5 parts of di- and tritaurinate (32%) were produced per hour. The anhydrous product contained 2.0% of 1,2-propane, pandiol and 0.4 % sodium sulfate.

The reaction was under otherwise identical conditions, but without the addition of 1,2-propanediol and 22 parts of sodium sulfate carried out, the reaction product contained 21 _X 9.5 parts Uatriumtaurinat (63%) and 129 parts of di- and Tritaurinat (37%) » The anhydrous product was contaminated with 6.2 % sodium sulfate.

Claims (2)

Claim for invention. ' -. ' 1. A process for the preparation of Ilatriumtaurinat by reaction of sodium isethionat with ammonia in the presence of electrolytes, characterized in that in the ^: mixture of the reactants partner 0.03 to 0, '5 percent by mass alkanediols and masimal 0.1 percent by mass of neutral electrolytes are included « ' 2. A process for the preparation of sodium taurinate according to item 1, characterized in that are used as alkanediols ethylene glycol and / or 1,2-propanediol.