Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/88—Ampholytes; Electroneutral compounds

Definitions

• amphoteric surfactants An important process for the production of amphoteric surfactants is based on condensation products of N-monosubstituted alkylenediamines, which are alkylated in a further reaction with alkylating agents, for example sodium chloroacetate. Products based on N-aminoethylethanolamine and fatty acids play a major role as skin-friendly surfactants.
• the quality of the amphoteric surfactants obtained and in particular their storage stability is crucially determined by the purity of the imidazoline derivative obtained in the first condensation step.
• the reaction between fatty acids and Aminoalkylalkanolaminen extends not only towards the formation of the desired Imidazolinderiva- t s e, multiple side reactions complicate the reaction. The importance of this aspect has been exposed again only recently, see EC Lomax "N ew and improved balanced amphoterics" Manufacturing Chemist and Aerosol News, Volume 50 no. 8, August 1979, pages 39 and 41.
• Described here is, for example, that the undesired side reactions in the stage of imidazoline formation can be suppressed by an excess of aminoethylethanolamine, but this excess must be removed by distillation at the end of the reaction. Excess aminoethylethanolamine, in turn, can create new difficulties by cycling to piperazine.
• the purity of the imidazoline obtained in the first reaction stage has a decisive influence on the storage stability of the amphoteric surfactants or their aqueous solutions obtained by subsequent alkylation. Even a small amount of contamination leads to the separation of a solid phase after a shorter or longer storage period, be it in the form of cloudiness or precipitation. Such products are unusable for practical use or at least of limited value.
• the invention is based on the object of creating improvements in the production of the class of amphoteric surfactants described here, which are characterized in particular by increased storage stability of the amphoteric surfactants.
• the invention aims to eliminate the troublesome by-products present here by switching on a simple cleaning step on the condensate of aminoalkylalkanolamine and fatty acid obtained in the first place.
• the invention is intended to make the previously expensive detours for obtaining the purest possible condensation product of this first process stage superfluous.
• the teaching of the invention is based on the surprising finding that the crude condensation product of fatty acids and aminoalkylalkanolamines can be converted by simple alkaline hydrolysis to a refined product which, in the subsequent alkylation and optionally quaternization, provides improved amphoteric surfactants with, in particular, increased storage stability.
• the invention accordingly relates to a process for refining the crude condensation product from aminoalkylalkanolamines of the general formula and fatty acids having 6 to 22 carbon atoms and, if desired, for subsequent alkylation and, if appropriate, quaternization of the purified condensation product to amphoteric surfactants with increased storage stability, this process being characterized in that the crude condensation product of fatty acids and aminoalkylalkanolamines is subjected to alkaline hydrolysis.
• the amount of alkali used in this alkaline hydrolysis is preferably based on the amount of the diamide of the general formula present in the crude condensate Voted.
• the amount of alkali is dimensioned in this process stage so that it is preferred is present in the crude condensation product in at least approximately an equimolar amount to the diamide.
• the invention is based on the finding that the content of disruptive by-products in the finished surfactant can be drastically reduced if the fatty acid / amine condensation product is subjected to an alkaline pretreatment in an aqueous medium before a further reaction with alkylating agents.
• diamide formed in particular in the course of the reaction by aqueous alkali on the tert.
• Amide group quantitatively split into the monoamide of the primary amino group and fatty acid.
• the fatty acid forms soap which can remain in the reaction mixture.
• the alkaline pretreatment according to the invention gives products which remain clear even after dilution for longer than 6 months. Costly cleaning steps such as recovery of the excess amine or distillation of the imidazoline are no longer necessary.
• the alkaline hydrolytic treatment according to the invention is preferably carried out at temperatures of approximately 70 to 100 ° C., in particular in the temperature range of 80 to 90 ° C.
• Alkali hydroxides, especially sodium hydroxide are particularly suitable as alkalis.
• the amount of alkali is preferably in the range of about 1 to 3 times the eguimolar alkali requirement, based on the diamide present in the crude condensation product. In particular, alkali amounts in the range of 1 to 2 equivalents, based on diamide, are used.
• the crude condensation product is expediently suspended in an amount of water which corresponds to 0.5 to 10 times, in particular 1 to 5 times, the crude condensation product.
• the aqueous alkaline hydrolysis is carried out until the diamide present as a by-product is virtually completely eliminated.
• the diamide content of the crude product and its decrease in the treatment according to the invention can be e.g. can be determined by working with ion exchangers.
• aminoalkylalkanolamines of the general formula those compounds are used in which m has the value from 2 to 6 and n has the value from 2 or 3.
• the meaning of m is preferably 2, 3 or 6, the preferred meaning for n is 2.
• the most important starting amine in practice of the type concerned here is aminoethylethanolamine.
• the fatty acids related to the condensation have carbon numbers in the range from 6 to 22, with particular importance in the range from 8 to 18 carbon atoms Has.
• the carboxylic acids can be present as pure components or as mixtures. They can be of natural and / or synthetic origin.
• the condensation product pretreated in the sense of the invention by the alkaline hydrolysis is then converted in a manner known per se to the finished amphoteric surfactant.
• the pretreatment according to the invention proves to be valuable not only for the production of the so-called imidazolinium surfactants, but rather it can be used in many different ways.
• amphoteric surfactants can have alkylated and optionally quaternized nitrogen in the second reaction stage.
• the invention comprises the production of such amphoteric surfactants using a condensation precursor which has been treated according to the alkaline hydrolytic process of the invention described.
• the percentages relate to% by weight.
• the diamide content is determined as follows: The condensation product is sent as an alcoholic solution through a strongly acidic ion exchanger. The eluate is evaporated and the remaining residue is related to the weight. By determining the S.Z. and the total nitrogen, the amount of diamide can be calculated.
• Imidazoline content 3.0%
• the product is clear as in 2.1.1, but also clouded after 6 days because not all diamide has been saponified.
• the finished product is clear and thin, but shows deposits after 2 days.
• the end product is clear, but becomes cloudy after 3 days.
• the product is still clear after more than 6 months.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Detergent Compositions (AREA)
• Photovoltaic Devices (AREA)
• Fats And Perfumes (AREA)

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• 1980
  • 1980-05-13 DE DE19803018201 patent/DE3018201A1/de not_active Withdrawn
• 1981
  • 1981-05-02 DE DE8181103328T patent/DE3161875D1/de not_active Expired
  • 1981-05-02 EP EP81103328A patent/EP0040346B1/fr not_active Expired
  • 1981-05-02 AT AT81103328T patent/ATE5815T1/de not_active IP Right Cessation
  • 1981-05-11 CA CA000377290A patent/CA1214778A/fr not_active Expired
  • 1981-05-12 BR BR8102948A patent/BR8102948A/pt not_active IP Right Cessation
  • 1981-05-12 ES ES502137A patent/ES502137A0/es active Granted
  • 1981-05-13 MX MX187279A patent/MX156685A/es unknown
  • 1981-05-13 JP JP7284281A patent/JPS5716846A/ja active Granted
  • 1981-05-13 AU AU70511/81A patent/AU541532B2/en not_active Ceased

Patent Citations (2)

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