DE19806495C1 - Production of anhydrous dust-free fatty acid polyglycol ester sulphate granulate - Google Patents

Abstract

The method involves drying an at least 20 wt.% solids aqueous paste of a fatty acid polyglycol ester sulphate (I) in a horizontal thin-film evaporator with rotating units to below 2 wt.% water residue while simultaneously converting it to lumps, there being a decreasing temperature gradient from the inlet to the outlet and a countercurrent air flow, and the drying taking place exclusively on the heated wall.

Description

Field of the invention

The invention relates to a process for the simultaneous drying and granulation of aqueous fat acid polyglycol ester sulfate pastes using a thin film evaporator.

State of the art

Fatty acid polyglycol ester sulfates are characterized by excellent detergent properties and high ecotoxicological compatibility. For this reason, these anionic surfactants gain in too increasing importance. In addition to use in liquid formulations, such as For example, dishwashing or hair shampoos, there is now also a market need for solid, water-free forms of preparation, which, for example, also in powder detergent, tooth incorporate creams or syndet soaps.

The drying of liquid surfactant preparations is carried out industrially usually by conventional Spray drying, in which the aqueous surfactant paste at the top of a tower in the form of fine droplets sprayed to which hot drying gases are fed. The drastic conditions lead however, often cause hydrolysis, undesired discoloration of the products, An Baking on the walls of the spray towers and in consequence to impurities of the dry good by charred residues. The always required cleaning of the towers also leads to Downtime, which makes the process sometimes costly. Another problem is further in that prior art methods are not among the most preferred heavy powders a bulk density above 500 g / l with a simultaneously greatly reduced dust content leads. However, these two parameters are economic, application and safety reasons of particular importance.

From the German patent application DE 42 09 339 A1 (Henkel) is a process for the preparation free-flowing detergent and cleaning granules known in which the drainage in turbines  dryers, d. H. in cylindrical dry equipment in horizontal design with rotating internals he follows. It is also possible to use anionic surfactants containing sulfate structure containing detergent pastes be dried.

Accordingly, the complex object of the present invention has been to provide aqueous fatty acid Polyglycolestersulfatpasten with the least possible technical effort without the concomitant use of transfer inorganic or organic carriers into practically water and dust-free granules, at the same time by an acceptable color quality, a high bulk density, good flowability, a satisfactory storage stability and compared to the products of the prior art characterized by at least comparable performance properties.

Description of the invention

The invention relates to a process for the preparation of water- and dust-free Anionten High bulk density sidegranules comprising aqueous pastes of fatty acid polyglycol ester sulfates having a solids content of at least 20 and preferably in the range of 25 to 75% by weight in a horizontally arranged thin-film evaporator with rotating internals up to a residual water content below 2, preferably below 1.5 and in particular below 1 wt .-% simultaneously dries and brings in lumpy form, wherein one of the thin film evaporator from Product input applies to the product discharge a negative temperature gradient, in countercurrent aerated with air and the drying takes place exclusively on the heated wall.

Surprisingly, it has been found that a horizontally arranged thin film evaporator in Ideally, aqueous Fettsäurepolyglycolestersulfatpasten in dry, light colored, trickle convert capable and non-sticky granules, without causing product discoloration and caking comes on the walls. The products have a high bulk density in the range of 550 to 650 g / l and a mean grain diameter of 2.0 to 2.8 mm, resulting in a reduction in the unwanted water absorption and the caking of the particles leads. That way is also given a high storage stability. At the same time they are dust-free, d. H. the proportion of particles with a diameter below 200 microns is below 5 wt .-%. This realization is so Surprisingly, since components of the type mentioned basically for the drying of recyclables However, the resulting powder, neither in terms of bulk density, nor the dust and residual water content meet the stated requirements. In a special Ausfüh tion form of the invention, mixtures of fatty acid polyglycol ester sulfates with alkyl and / or Alkenyloligoglycosides, fatty acid N-alkylpolyhydroxyalkylamides, monoglyceride (ether) sulfates or Betainen used.  

fatty acid polyglycol ester

Fatty acid polyglycol ester sulfates which preferably follow formula (I),

R ¹ COO (AO) _x SO ₃ X (I)

in the R ¹ CO for a linear or branched, saturated or unsaturated acyl radical having 6 to 22 carbon atoms, x is an average of 1 to 3 and AO is a CH ₂ CH ₂ O-, CH ₂ CH (CH ₃ ) O- and or CH (CH ₃ ) CH ₂ O radical and X is an alkali and / or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium, represent known anionic surfactants and are prepared by sulfation of the corresponding fatty acid polyglycol esters. These in turn are available according to the relevant preparative methods of organic chemistry. For this purpose, ethylene oxide, propylene oxide or their mixture - in random or block distribution- attached to the corresponding fatty acids, said reaction acid catalysed, but preferably in the presence of bases such. For example, sodium methylate or calcined hydrotalcite. If a degree of alkoxylation of 1 is desired, the intermediates may also be prepared by esterification of the fatty acids with a corresponding alkylene glycol. The sulfation of the Fettsäurepolyglycolester can be carried out in a conventional manner with chlorosulfonic acid or preferably gaseous sulfur trioxide, wherein the molar ratio between fatty acid polyglycolester and sulfating agent in the range of 1: 0.95 to 1: 1.2, preferably 1: 1 to 1: 1.1 and the reaction temperature 30 to 80 and preferably 50 to 60 ° C. It is also possible to sulfonate the fatty acid polyglycol esters, ie to use significantly less sulfating agent than would be required stoichiometrically for complete conversion. If, for example, molar amounts of fatty acid polyglycol ester to sulfating agent of 1: 0.5 to 1: 0.95 are selected, mixtures of fatty acid polyglycol ester sulfates and fatty acid polyglycol esters are obtained, which are also advantageous for a whole range of applications. In order to avoid hydrolysis, it is very important to carry out the neutralization at a pH in the range of 5 to 9, preferably 7 to 8. Typical examples of suitable starting materials are the An to storage products of 1 to 3 moles of ethylene oxide and / or propylene oxide, but preferably the adducts with 1 mole of ethylene oxide or 1 mole of propylene oxide to caproic, caprylic, 2-ethylhexanoic, capric, lauric, isotridecanoic, myristic, palmitic , Palmitoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, elaeostearic acid, arachic acid, gadoleic acid, behenic acid and erucic acid and their technical mixtures, which are then sulfated and neutralized as described above. Preferably, fatty acid polyglycol ester sulfates of the formula (I) are used in which R ¹ CO is an acyl radical having 12 to 18 carbon atoms, x is an average of 1 or 2, AO is a CH ₂ CH ₂ O group and X is sodium or ammonium, such as for example, lauric acid + 1EO sulfate sodium salt, lauric acid + 1EO sulfate ammonium salt, coconut fatty acid + 1EO sulfate sodium salt, coconut fatty acid + 1EO sulfate ammonium salt, tallow fatty acid + 1EO sulfate sodium salt, tallow fatty acid + 1EO sulfate ammonium salt and their mixtures.

Alkyl and / or alkenyl oligoglycosides

Alkyl and alkenyl oligoglycosides which can be co-dried as optional surfactants are known nonionic surfactants which follow the formula (II),

R ² O- [G] _p (II)

in which R ^{2 is} an alkyl and / or alkenyl radical having 4 to 22 carbon atoms, G is a sugar radical having 5 or 6 carbon atoms and p is a number from 1 to 10. They can be obtained by the relevant procedures of preparative organic chemistry. Representative of the extensive literature is hereby referred to the documents EP 0301298 A1 and WO 90/03977 A1. The alkyl and / or alkenyl oligoglycosides can be derived from aldoses or ketoses with 5 or 6 carbon atoms, preferably glucose. The preferred alkyl and / or alkenyl oligoglycosides are thus alkyl and / or alkenyl oligoglucosides. The index number p in the general formula (II) indicates the degree of oligomerization (DP), ie the distribution of monoglycerides and oligoglycosides, and stands for a number between 1 and 10. While p in a given compound must always be an integer, and here especially If the values p = 1 to 6 can be assumed, the value p for a given alkyloligoglycoside is an analytically determined arithmetical variable, which usually represents a fractional number. Before preferably alkyl and / or Alkenyloligoglykoside be used with a mean degree of oligomerization p of 1.1 to 3.0. From an application point of view, those alkyl and / or Alkenyloligo glycosides are preferred whose degree of oligomerization is less than 1.7 and in particular between 1.2 and 1.4. The alkyl or alkenyl radical R ² can be derived from primary alcohols having 4 to 11, preferably 8 to 10 carbon atoms. Typical examples are butanol, caproic alcohol, caprylic alcohol, capric alcohol and undecyl alcohol and their technical mixtures, as obtained for example in the hydrogenation of technical fatty acid methyl esters or in the course of the hydrogenation of aldehydes from the Roelen oxo synthesis. Alkyloligoglu cosides of chain length C ₈ -C ₁₀ (DP = 1 to 3) are preferred, which are obtained as a feedstock in the distillative separation of technical C ₈ -C ₁₈ coconut fatty alcohol and with a proportion of less than 6 wt .-% C ₁₂ alcohol may be contaminated as well as alkyl oligoglucosides based on technical C _9/11 oxo alcohols (DP = 1 to 3). The alkyl or alkenyl radical R ² can also be derived from primary alcohols having 12 to 22, preferably 12 to 14 carbon atoms. Typical examples are lauryl alcohol, myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, brassidyl alcohol and technical mixtures thereof which can be obtained as described above. Preference is given to alkyl oligoglucosides based on hydrogenated C _12/14 coconut alcohol having a DP of 1 to 3.

Fatty acid N-alkyl polyhydroxyalkylamides

Fatty acid N-alkylpolyhydroxyalkylamides, which can also be co-dried as optional surfactants, are nonionic surfactants which follow formula (III),

in which R ³ CO is an aliphatic acyl radical having 6 to 22 carbon atoms, R ^{4 is} an alkyl or hydroxyalkyl radical having 1 to 4 carbon atoms and [Z] is a linear or branched polyhydroxyalkyl radical having 3 to 12 carbon atoms and 3 to 10 hydroxyl groups , The fatty acid N-alkylpolyhydroxyalkylamides are known substances which can usually be obtained by re ductive amination of a reducing sugar with ammonia, an alkylamine or an alkanolamine and subsequent acylation with a fatty acid, a fatty acid alkyl ester or a fatty acid chloride. With regard to the process for their preparation, reference is made to US Pat. Nos. 1,985,424, 2,016,962 and 2,703,798, and International Patent Application WO 92/06984 A1. An overview of this topic by H. Kelkenberg can be found in Tens. Surf. Deterg. 25, 8 (1988). Preferably, the fatty acid N-alkylpolyhydroxyalkylamides are derived from reducing sugars having 5 or 6 carbon atoms, especially glucose. The preferred fatty acid N-alkyl-polyhydroxyalkylamides are therefore fatty acid N-alkylglucamides as represented by formula (IV):

Preferably, the fatty acid N-alkylpolyhydroxyalkylamides are glucamides of the formula (IV) in which R ^{4 is} methyl and R ³ CO is the acyl radical of caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, Oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, arachidic acid, gadoleic acid, behenic acid or erucic acid or whose technical mixtures. Particular preference is given to fatty acid N-alkylglucamides of the formula (IV) which are obtained by reductive amination of glucose with methylamine and subsequent acylation with lauric acid or C _12/14 coconut fatty acid or a corresponding derivative. Furthermore, the polyhydroxyalkylamides can also be derived from maltose and palatinose.

Monoglyceride (ether) sulfates

Monoglyceride sulfates and monoglyceride ether sulfates, which can also be dried as further anionic surfactants, are known substances which can be obtained by the relevant methods of preparative organic chemistry. Usually, triglycerides are used for their preparation, which are optionally transesterified after ethoxylation to the monoglycerides and subsequently sulfated and neutralized. Likewise, it is possible to add the partial glycerides with suitable sulfating agents, preferably gaseous sulfur trioxide or chlorosulfonic acid [cf. EP 0561825 B1, EP 0561999 B1 (Henkel)]. If desired, the neutralized substances can be subjected to ultrafiltration in order to reduce the electrolyte content to a desired level [DE 42 04 700 A1 (Henkel)]. Overviews of the chemistry of the monoglyceride sulfates are described, for example, by AK Biswas et al. in J. Am. Oil, Chem. Soc. 37, 171 (1960) and FU Ahmed J. Am. Oil, Chem. Soc. 67, 8 (1990). The monoglyceride (ether) sulfates to be used according to the invention preferably follow the formula (V),

in which R ⁵ CO is a linear or branched acyl radical having 6 to 22 carbon atoms, x, y and z are in total 0 or numbers of 1 to 30, preferably 2 to 10, and X is an alkali metal or alkaline earth metal. Typical examples of monoglyceride (ether) sulfates suitable for the purposes of the invention are the decomposition products of lauric acid monoglyceride, coconut fatty acid monoglyceride, palmitic acid monoglyceride, stearic acid monoglyceride, oleic acid monoglyceride and tallow fatty acid monoglyceride and their ethylene oxide adducts with sulfur trioxide or chlorosulfonic acid in the form of their sodium salts. Before preferably monoglyceride sulfates of the formula (V) are used, in which R ⁵ CO is a linear acyl radical having 8 to 18 carbon atoms. The monoglyceride (ether) sulfates are preferably used as dried granules or powders, which can be obtained, for example, by drying aqueous pastes in a flash dryer.

Betaine

Finally, betaines which can also be dried as representatives of the amphoteric or zwitterionic surfactants are known substances which are predominantly produced by carboxyalkylation, preferably by carboxymethylation of aminic compounds. Preferably, who the starting materials with halocarboxylic acids or their salts, in particular with sodium chloroacetate condensed, wherein per mole of betaine one mole of salt is formed. Furthermore, the Anla delay of unsaturated carboxylic acids, such as acrylic acid is possible. For nomenclature, and in particular for the distinction between betaines and "real" amphoteric surfactants, reference should be made to the article by U. Ploog in Soaps Oils-Fette-Wachse, 198, 373 (1982). Further reviews on this topic can be found, for example, by A. O'Lennick et al. in HAPPI, Nov. 70 (1986), S. Holzman et al. in tens. Surf. Det. 23, 309 (1986), R. Bilbo et al. in Soap Cosm. Chem. Spec., Apr. 46 (1990) and P. Ellis et al. in Euro Cosm. 1, 14 (1994). Examples of suitable betaines are the carboxyalkylation products of secondary and in particular tertiary amines which follow the formula (VI),

in the R ⁶ for alkyl and / or alkenyl radicals having 6 to 22 carbon atoms, R ^{7 is} hydrogen or alkyl radicals having 1 to 4 carbon atoms, R ^{8 is} alkyl radicals having 1 to 4 carbon atoms, n is from 1 to 6 and X is an integer Alkali and / or alkaline earth metal or ammonium. Typical examples are the carboxymethylation of hexylmethylamine, hexyldimethylamine, octyldimethylamine, De cyldimethylamin, dodecylmethylamine, dodecyldimethylamine, dodecylethylmethylamine, C _12/14 cocodimethylamine, myristyldimethylamine, cetyldimethylamine, stearyldimethylamine, stearylethylmethyl amine, oleyldimethylamine, C _16/18 -Talgalkyldimethylamin and their technical mixtures , Also suitable are carboxyalkylation products of amidoamines which follow the formula (VII),

in which R ^{9 is} CO for an aliphatic acyl radical having 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, m is a number from 1 to 3 and R ⁷ , R ⁸ , n and X are as defined above. Typical examples are reaction products of fatty acids having 6 to 22 carbon atoms, namely caproic, caprylic, capric, lauric, myristic, palmitic, palm oleic, stearic, isostearic, oleic, elaidic, petroselic, linoleic, linolenic, elaeostearic, arachidic, gadoleic, behenic and erucic acid and their technical mixtures, with N, N-dimethylaminoethylamine, N, N-dimethylaminopropylamine, N, N-diethylaminoethylamine and N, N-diethylaminopropylamine, which are condensed with sodium chloroacetate. Be preferred is the use of a condensation product of C _8/18 coconut fatty acid-N, N-dimethyl aminopropylamide with sodium chloroacetate.

Dry and granulate in Flashdryer

The simultaneous drying and granulation is carried out in a horizontally arranged thin film evaporator with rotating internals, as he z. B. marketed by the company VRV under the name "Flashdryer". This is, in simplified terms, a tube that can be tempered differently over several zones. About one or more waves, which are provided with blades or flying crowds as rotating internals, the pasty feed, which is metered via a pump, is thrown against the heated wall at which the drying in a thin layer of typically 1 to 10 mm thickness he follows. For the purposes of the invention, it has proved to be advantageous to apply to the thin-film evaporator a temperature gradient of 170 (product inlet) to 20 ° C (product discharge). For this example, the first two zones of the evaporator can be heated to 160 ° C and the last cooled to 20 ° C. Higher drying temperatures have not proven to be advantageous in view of the thermal lability with concomitant use of sugar surfactants as other starting materials. The thin-film evaporator is operated at atmospheric pressure and gassed in countercurrent with air (throughput 50 to 150 m ³ / h). The inlet temperature of the gas is usually 20 to 30, the outlet temperature at 90 to 110 ° C. The aqueous fatty acid polyglycol ester sulfate pastes, which are suitable as feedstocks, may have a solids content in the range above 20, preferably from 25 to 75 wt .-%; it is typically from 30 to 50% by weight. The throughput is of course dependent on the size of the dryer, but is typically 5 to 15 kg / h. It is recommended to temper the pastes at the feed to 40 to 60 ° C. After drying, it has also proved to be very advantageous to give the still about 50 to 70 ° C hot granules on a conveyor belt, preferably a rocker shaft and there quickly, ie within a residence time of 20 to 60 s, with ambient air to temperatures of To cool about 30 to 40 ° C. To further improve the resistance to unwanted water absorption, the granules can also be powdered by adding 0.5 to 2 wt .-% silica.

Industrial Applicability

The granules obtainable by the process according to the invention can subsequently be further Ingredients of powdered surfactants, such as tower powders for Detergents are mixed. It is also easily possible, the powder in aqueous preparations incorporate. In fact, when using the powder over the aqueous starting material pastes no differences in the performance properties observed. Also in straight For example, the granules can be packed with soybeans of the Combibar or Syndett type together with Fatty acids, fatty acid salts, fatty alcohols, starch, polyglycols, and the like work.

Examples example 1

The granules were produced in a flash dryer of VRV SpA, Milan / IT. This was a horizontally arranged thin film evaporator (length 1100 mm, inner diameter: 155 mm) with 4 shafts and 22 leaves whose distance from the wall was 2 mm. The dryer had three separate heating or cooling zones and a total heat exchange area of 0.44 m ² . The operation was carried out at normal pressure. About an oscillating pump tempered to 50 ° C aqueous paste of a lauric acid + 1EO sulfate sodium salt (solids content about 50 wt .-%) was pumped at a rate of 11.5 kg / h in the thin film evaporator, its heating zones 1 and 2 had been adjusted to 160 ° C and its cooling zone 3 to 20 ° C. The speed of the rotors was 24 m / s. The Flashdryer was gassed with air (about 110 m ³ / h); the gas outlet temperature was about 65 ° C. The predried, still about 60 ° C hot granules were placed on a vibrating trough (length 1 m), fumigated with room air and cooled to about 40 ° C within 30 s. It was then powdered with about 1 wt .-% silica (Sipemat® 50 S). It was a dry, pure white, even after prolonged storage in the air free-flowing and non-clumping granules were obtained, which showed no difference to egg nem pasty comparative product after incorporation into shampoo formulations. The characteristics of the granules are reproduced in Table 1.

Table 1 Characteristics of the Flashdryer granulate

Parameter grain size distribution granules <1.0 mm 1.4% by weight 1.0 mm 45.7% by weight 2.5 mm 16.8% by weight 3.2 mm 17.7% by weight 4.0 mm 11.0% by weight 5.0 mm 5.5% by weight <6.2 mm 1.9% by weight Residual water content (according to Fischer) 0.7% by weight bulk density 620 g / l

Example 2

Example 1 was carried out with a mixture of 60% by weight of lauric acid + 1EO sulfate sodium salt and 40% by weight of cocoalkyl oligoglucoside (Plantacare® APG 1200). The temperature in the Both heating zones of the flash dryer were raised to 170 ° C. It also became a pure white, free-flowing and non-caking granules, which have a bulk density of 600 g / l and a Residual water content of 0.8 wt .-% had.

Example 3

Example 1 was mixed with a mixture of 60% by weight of coconut fatty acid + 1PO sulfate sodium salt and 40% by weight of coconut fatty alcohol (Lanette® O, Henkel KGaA). The temperature in the two Heating zones of the flash dryer were raised to 170 ° C. It was also a pure white, trickle obtainable and non-caking granules having a bulk density of 600 g / l and a remainder water content of 0.8 wt .-% had.

Example 4

Example 1 was mixed with a mixture of 30% by weight of lauric acid + 1EO sulfate sodium salt, 30% by weight. Coconut fatty acid monoglyceride sulfate and 40% by weight palm kernel fatty acid (Edenor PK®, Henkel KGaA). The temperature in the two heating zones of the flash dryer was at 170 ° C raised. It was also a pure white, free-flowing and non-clumping granules, which had a bulk density of 590 g / l and a residual water content of 0.8 wt .-%.

Example 5

Example 1 was mixed with a mixture of 30% by weight of lauric acid + 1EO sulfate sodium salt, 30% by weight. Kokosfettsäureamidopropylbetain (Dehyton® PK, Henkel KGaA) and 40 wt .-% palm kernel fatty acid (Edenor PK®, Henkel KGaA). The temperature in the two heating zones of the flash dryers was raised to 170 ° C. It was also a pure white, free flowing and not obtained clumping granules having a bulk density of 600 g / l and a residual water content of 0.8 wt .-% had.

Claims (10)

1. A process for the preparation of water and dust-free anionic surfactant granules with high bulk weight, wherein aqueous pastes of fatty acid polyglycol ester sulfates with a solid content of at least 20 wt .-% in a horizontally arranged thin-film evaporator with rotating internals to a residual water content below 2 wt .-% at the same time Dries and brings in lumpy form, taking the thin-film evaporator from the product input to the product discharge a decreasing temperature gradient applies, in the counter fumigated stream with air and the drying takes place exclusively on the heated wall. 2. The method according to claim 1, characterized in that one uses fatty acid polyglycol ester sulfates of the formula (I),
R ¹ COO (AO) _x SO ₃ X (I)
in the R ¹ CO for a linear or branched, saturated or unsaturated acyl radical having 6 to 22 carbon atoms, x is an average of 1 to 3 and AO is a CH ₂ CH ₂ O-, CH ₂ CH (CH ₃ ) O- and or CH (CH ₃ ) CH ₂ O radical and X is an alkali and / or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium. 3. Process according to claims 1 and 2, characterized in that together with the Fatty acid polyglycol ester sulfates employing other surfactants selected from the group consisting of which is formed by alkyl and / or alkenyl oligoglycosides, fatty acid N-alkylpolyhydroxyalkyl amides, monoglyceride (ether) sulfates and betaines and mixtures thereof. 4. The method according to claim 3, characterized in that one uses alkyl and / or alkenyl oligoglycosides of the formula (II),
R ² O- [G] _p (II)
in which R ^{2 is} an alkyl and / or alkenyl radical having 4 to 22 carbon atoms, G is a sugar radical having 5 or 6 carbon atoms and p is a number from 1 to 10. 5. The method according to claim 3, characterized in that one uses fatty acid-N-alkylpolyhydroxy alkylamides of the formula (III),
in which R ³ CO is an aliphatic acyl radical having 6 to 22 carbon atoms, R ^{4 is} an alkyl or hydroxyalkyl radical having 1 to 4 carbon atoms and [Z] is a linear or branched polyhydroxyalkyl radical having 3 to 12 carbon atoms and 3 to 10 hydroxyl groups. 6. The method according to claim 3, characterized in that one sets monoglyceride (ether) sulfate, which follow the formula (V),
in which R ⁵ CO is a linear or branched acyl radical having 6 to 22 carbon atoms, x, y and z are in total 0 or numbers of 1 to 30, preferably 2 to 10, and X is an alkali or alkaline earth metal. 7. The method according to claim 3, characterized in that alkyl betaines of the formula (VI) is used,
in the R ⁶ for alkyl and / or alkenyl radicals having 6 to 22 carbon atoms, R ^{7 is} hydrogen or alkyl radicals having 1 to 4 carbon atoms, R ^{8 is} alkyl radicals having 1 to 4 carbon atoms, n is from 1 to 6 and X is an integer Alkali and / or alkaline earth metal or ammonium. 8. The method according to claim 3, characterized in that one uses Alkylamidobetaine of formula (VII),
in which R ⁹ CO is an aliphatic acyl radical having 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, m is a number from 1 to 3 and R ⁷ , R ⁸ , n and X are as defined above. 9. Process according to claims 1 to 8, characterized in that one of the product entry until the discharge a temperature gradient of 170 to 20 ° C applies. 10. Process according to claims 1 to 6, characterized in that the granules after The powder is cooled with silica.