EP0966515B1 - Process for preparing raw materials for washing agents - Google Patents

Abstract

A process for producing solid detergent granular materials is presented involving (a) forming an aqueous surfactant paste of an anionic surfactant, an amphoteric surfactant or mixtures thereof, and (b) drying and granulating the aqueous paste in a horizontal thin-layer evaporator or dryer having rotating fittings, wherein the drying is carried out at a temperature of 120° C. to 130° C. The process produces granules having a bulk density greater than 600 grams/liter and a uniform particle size distribution.

Description

Field of the Invention

The invention relates to a method for contact drying of aqueous surfactant pastes in a horizontal Thin film evaporator or dryer.

State of the art

Anionic and amphoteric or zwitterionic surfactants are important components of solid Detergents and bar soaps. The usual procedure for producing the detergents is that an aqueous, generally highly alkaline slurry of the ingredients ("slurry") is sprayed and is dried in countercurrent with hot inert gases. After using this conventional Spray drying, however, involves a high level of pollution of the exhaust air associated with organic cargo a need for alternative drying methods that are more environmentally friendly. For this counts in particular the contact drying of aqueous surfactant pastes in thin film dryers leads dry products, which then for example in mixers with the other also dried Detergent ingredients can be processed to the final product.

From the European patent application EP-A1 0 572 957 (Kao) a process for drying alkyl or alkyl ether sulfates is known, in which dilute surfactant pastes are first concentrated to 60 to 80% by weight of active substance and then this is then vertical Thin film evaporator dries in a vacuum at temperatures in the range of 50 to 140 ° C. A major disadvantage of this process, however, is that working under reduced pressure requires technically complex, vacuum-suitable removal of the finished product. Due to the constant contact with the hot product, there is a risk of caking and thus malfunctions, which then necessitate a complete shutdown of the cleaning operation. Another decisive disadvantage is that the use of a vertical thin-film evaporator with wall contact of the rotor blades in continuous operation requires the maintenance of a flowable product film over the entire length of the apparatus on the wall in order to avoid mechanical overloading of the system, so that the process is not for direct production a powder, but only suitable for the production of a concentrated hot melt, which crystallizes separately (for example in a scale roller or one) and then has to be comminuted.

In contrast, in international patent application WO 96/06916 (Unilever) a method for Drying of aqueous anionic surfactant pastes in a horizontal thin-film evaporator proposed with a slight vacuum to almost normal pressure and temperatures above 130 ° C is working. Another feature of this method is the use of a very high peripheral speed of the stirring elements used of at least 15 m / s, which means direct wall contact practically excludes and leads to color-perfect products. When drying aqueous Anionic surfactant pastes, in particular aqueous pastes of alkyl sulfates or alkyl ether sulfates however, there is basically the risk of undesired hydrolysis in the product. Even short-term, selective In the presence of water, a drop in pH leads to cleavage, to the formation of inorganic ones Sulfate and to decrease the content of detergent. When reworking the teaching WO 96/06916 the applicant has found that over a period of several hours of operation cannot produce a hydrolysis-free product reproducibly.

The complex object of the invention was therefore a method for contact drying of aqueous anionic surfactant and / or amphoteric surfactant pastes available which the above Disadvantages described does not have and in particular with minimal technical effort Production conditions for color-perfect, hydrolysis-free, free-flowing granules with high Bulk weights and uniform grain size distribution leads.

Description of the invention

The invention relates to a process for the production of solid detergent raw materials by simultaneous drying and granulation of aqueous pastes of anionic and / or amphoteric Surfactants in a horizontal thin-film evaporator or dryer with rotating internals is characterized in that drying at a temperature in the range of 120 to 130 ° C. performs.

Surprisingly, it was found that the color-free, free-flowing granules are also straight then be obtained if the drying temperature is kept in the specified range. Nice slight upward deviations lead to an undesirable increase in the inorganic content Sulphate, slight downward deviations to products that do not have sufficient flow properties own more. The invention includes the finding that the hydrolysis tendency continues can be suppressed if the contact drying in the presence of (a) 0.05 to 0.5 wt .-% Performs alkali carbonate and / or (b) an alkaline gas stream. The water removal is preferably carried out by a gas stream and not by applying a vacuum. Another advantage of the process is that products with a high bulk density (above of 600 g / l) are obtained, which are very uniform regardless of the surfactant paste used Show grain size distribution.

Surfactants

Typical examples of anionic surfactants which can be dried in the sense of the method according to the invention are soaps, alkylbenzenesulfonates, alkanesulfonates, olefin sulfonates, alkyl ether sulfonates, glycerol ether, α-methyl ester sulfonates, sulfofatty acids, alkyl sulfates, fatty alcohol ether sulfates, Glycerol ether, Hydroxymischethersulfate, monoglyceride (ether) sulfates, fatty acid amide (ether) sulfates, mono- and dialkylsulfosuccinates, mono- and dialkylsulfosuccinamates, sulfotriglycerides, amide soaps, ether carboxylic acids and their salts, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, N-acylamino acids such as, for example, acyl lactylates, acyl sulfasate fatty acid products, acyl sulfasate fatty acid products, based on wheat), alkyl (ether) phosphates and sulfates of ring opening products of olefin epoxides with water or alcohols. If the anionic surfactants contain polyglycol ether chains, they can have a conventional, but preferably a narrow, homolog distribution. Typical examples of amphoteric or zwitterionic surfactants are alkyl betaines, alkyl amido betaines, aminopropionates, aminoglycinates, imidazolinium betaines and sulfobetaines. The surfactants mentioned are exclusively known compounds. With regard to the structure and manufacture of these substances, reference is made to relevant reviews, for example J.Falbe (ed.), "Surfactants in Consumer Products", Springer Verlag, Berlin, 1987, pp. 54-124 or J.Falbe (ed.), "Catalysts, Tenside und Mineralöladditive ", Thieme Verlag, Stuttgart, 1978, pp. 123-217 .

In this context, the term aqueous pastes includes aqueous preparations of the surfactants to understand that an active substance content in the range of 5 to 80, preferably 10 to 70 wt .-% exhibit. For energetic and rheological reasons, it is advantageous to use pastes that Solids content of at least 30, better 50, and a maximum of 70 wt .-%. The anionic surfactant are in the form of their alkali, alkaline earth, ammonium, alkylammonium, alkanolammonium, glucammonium salts used. In further preferred embodiments of the process, alkyl and / or alkenyl (ether) sulfates, sulfosuccinates and / or betaines dried and to light-colored, free-flowing granules processed.

Alkyl and / or alkenyl sulfates

Alkyl and / or alkenyl sulfates, which are also often referred to as fatty alcohol sulfates, are to be understood as meaning the sulfation products of primary alcohols which preferably follow the formula (I) R ¹ O-SO ₃ X (I) in which R ^{1 is} a linear or branched, aliphatic alkyl and / or alkenyl radical having 6 to 22, preferably 12 to 18 carbon atoms and X is an alkali and / or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium. Typical examples of alkyl sulfates which can be used for the purposes of the invention are the sulfation products of capron alcohol, caprylic alcohol, capric alcohol, 2-ethylhexyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, arachelyl alcohol, aridyl alcohol, ela-elyl alcohol, ela-alcohol alcohol, and erucyl alcohol and their technical mixtures, which are obtained from high pressure hydrogenation of technical methyl ester fractions or aldehydes from Roelen's oxosynthesis. Guerbet alcohols with 16 to 32 carbon atoms can also serve as raw materials. The sulfation products can preferably be used in the form of their alkali metal salts, and in particular their sodium salts. Alkyl sulfates based on C _16/18 tallow fatty alcohols or vegetable fatty alcohols of comparable C chain distribution in the form of their sodium salts are particularly preferred.

Alkyl and / or alkenyl ether sulfates

Alkyl and / or alkenyl ether sulfates (“ether sulfates”) are known anionic surfactants which are produced on an industrial scale by SO ₃ - or chlorosulfonic acid (CSA) sulfation of oxoalcohol or fatty alcohol polyglycol ethers and subsequent neutralization. For the purposes of the invention, ether sulfates are suitable which follow the formula (II) R ² O- (CH ₂ CH ₂ O) _m SO ₃ X (II) in which R ^{2 stands} for a linear or branched alkyl and / or alkenyl radical with 6 to 22 carbon atoms, m for numbers from 1 to 10 and X for an alkali and / or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium. Typical examples are the sulfates of addition products with an average of 1 to 10 and in particular 2 to 5 moles of ethylene oxide with capron alcohol, caprylic alcohol, 2-ethylhexyl alcohol, capric alcohol, lauryl alcohol, isotridecyl alcohol, myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, oleyl alcohol, Arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol and brassidyl alcohol and their technical mixtures, in the form of their sodium and / or magnesium salts. Addition products of ethylene oxide with Guerbet alcohols with 16 to 32 carbon atoms can also be used as raw materials. The ether sulfates can have both a conventional and a narrow homolog distribution. It is particularly preferred to use ether sulfates based on adducts of an average of 2 to 3 mol ethylene oxide with technical C _12/14 or G _12/18 coconut fatty _{alcohol fractions} in the form of their sodium and / or magnesium salts.

Sulfosuccinates

in der R³ für einen Alkyl- und/oder Alkenylrest mit 6 bis 22 Kohlenstoffatomen, R⁴ für R³ oder X, p und q unabhängig voneinander für 0 oder Zahlen von 1 bis 10 und X für ein Alkali- oder Erdalkalimetall, Ammonium, Alkylammonium, Alkanolamonium oder Glucamonium steht.Zu ihrer Herstellung geht man üblicherweise von Maleinsäure, vorzugsweise aber Maleinsäureanhydrid aus, die im ersten Schritt mit gegebenenfalls ethoxylierten primären Alkoholen verestert werden. An dieser Stelle kann durch Variation von Alkoholmenge und Temperatur das Mono-/Diester-Verhältnis eingestellt werden. Im zweiten Schritt erfolgt die Anlagerung von Bisulfit, die üblicherweise im Lösungsmittel Methanol durchgeführt wird. Neuere Übersichten zu Herstellung und Verwendung von Sulfosuccinaten sind beispielsweise von T.Schoenberg in Cosm. Toil. 104, 105 (1989), J.A.Milne in R. Soc. Chem. (Ind. Appl. Surf.ll) 77, 77 (1990) sowie W.Hreczuch et al. in J. Am. Oil. Chem. Soc. 70, 707 (1993) erschienen. Typische Beispiele sind Sulfobemsteinsäuremono- und/oder -diester in Form ihrer Natriumsalze, die sich von Fettalkoholen mit 8 bis 18, vorzugsweise 8 bis 10 bzw. 12 bis 14 Kohlenstoffatomen ableiten; die Fettalkohole können dabei mit durchschnittlich 1 bis 10 und vorzugsweise 1 bis 5 Mol Ethylenoxid verethert sein und dabei sowohl eine konventionelle als auch vorzugsweise eine eingeengte Homologenverteilung aufweisen. Exemplarisch genannt seien Di-n-octylsulfosuccinat und Monolauryl-3EO-sulfosuccinat in Form ihrer Natriumsalze. Sulfosuccinates, which are also referred to as sulfosuccinic acid esters, are known anionic surfactants which can be obtained by the relevant methods of preparative organic chemistry. They follow formula (III)

in which R ^{3 is} an alkyl and / or alkenyl radical having 6 to 22 carbon atoms, R ^{4 is} R ³ or X, p and q independently of one another are 0 or numbers from 1 to 10 and X is an alkali or alkaline earth metal, ammonium, Alkylammonium, alkanolamonium or glucamonium. For their preparation, one usually starts from maleic acid, but preferably maleic anhydride, which are esterified in the first step with optionally ethoxylated primary alcohols. At this point, the mono / diester ratio can be adjusted by varying the amount of alcohol and the temperature. In the second step, bisulfite is added, which is usually carried out in the solvent methanol. More recent reviews of the manufacture and use of sulfosuccinates are, for example, from T. Schoenberg in Cosm. Toil. 104 , 105 (1989), JAMilne in R. Soc. Chem. (Ind. Appl. Surf.ll) 77, 77 (1990) and W. Hreczuch et al. in J. Am. Oil. Chem. Soc. 70, 707 (1993) . Typical examples are sulfosuccinic acid monoesters and / or diesters in the form of their sodium salts which are derived from fatty alcohols having 8 to 18, preferably 8 to 10 or 12 to 14, carbon atoms; the fatty alcohols can be etherified with on average 1 to 10 and preferably 1 to 5 moles of ethylene oxide and can have both a conventional and preferably a narrowed homolog distribution. Examples include di-n-octyl sulfosuccinate and monolauryl 3EO sulfosuccinate in the form of their sodium salts.

Betaine

in der R⁵ für Alkyl- und/oder Alkenylreste mit 6 bis 22 Kohlenstoffatomen, R⁶ für Wasserstoff oder Alkylreste mit 1 bis 4 Kohlenstoffatomen, R⁷ für Alkylreste mit 1 bis 4 Kohlenstoffatomen, x für Zahlen von 1 bis 6 und Y für ein Alkali- und/oder Erdalkalimetall oder Ammonium steht, Typische Beispiele sind sind die Carboxymethylierungsprodukte von Hexylmethylamin, Hexyldimethylamin, Octyldimethylamin, Decyldimethylamin, Dodecylmethylamin, Dodecyldimethylamin, Dodecylethylmethylamin, C_12/14-Kokosalkyldimethylamin, Myristyldimethylamin, Cetyldimethylamin, Stearyldimethylamin, Stearylethylmethylamin, Oleyldimethylamin, C_16/18-Talgalkyldimethylamin, Guerbetamine sowie deren technische Gemische.Betaines are known surfactants which are predominantly produced by carboxyalkylation, preferably carboxymethylation, of aminic compounds. The starting materials are preferably condensed with halocarboxylic acids or their salts, in particular with sodium chloroacetate, one mol of salt being formed per mole of betaine. Furthermore, the addition of unsaturated carboxylic acids such as acrylic acid is also possible. Regarding the nomenclature and in particular the distinction between betaines and "real" amphoteric surfactants, reference is made to the contribution by U.Ploog in Seifen-Öle-Fette-Wwachs, 198 , 373 (1982) . Further overviews 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. Det. 23: 309 (1986), R.Bibo 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 (IV) ,

in which R ^{5 represents} alkyl and / or alkenyl radicals having 6 to 22 carbon atoms, R ^{6 represents} hydrogen or alkyl radicals having 1 to 4 carbon atoms, R ^{7 represents} alkyl radicals having 1 to 4 carbon atoms, x represents numbers from 1 to 6 and Y represents a Alkali metal and / or alkaline earth metal or ammonium, typical examples are the carboxymethylation products of hexylmethylamine, hexyldimethylamine, octyldimethylamine, decyldimethylamine, dodecylmethylamine, dodecyldimethylamine, dodecylethylmethylamine, C _12/14 cocoalkyldimethylethylethyl, methyl, cistyldimethylamethylamine, myristyl, methyldimethylamine, myristin, cimethyldimethylamethylamine, cistyldimethylamethylamine, _{16 / 18} -Talgalkyldimethylamin, Guerbetamine and their technical mixtures.

in der R⁸CO für einen aliphatischen Acylrest mit 6 bis 22 Kohlenstoffatomen und 0 oder 1 bis 3 Doppelbindungen, y für Zahlen von 1 bis 3 steht und R⁶, R⁷, x und Y die oben angegebenen Bedeutungen haben. Typische Beispiele sind Umsetzungsprodukte von Fettsäuren mit 6 bis 22 Kohlenstoffatomen, namentlich Capronsäure, Caprylsäure, Caprinsäure, Laurinsäure, Myristinsäure, Paimitinsäure, Palmoleinsäure, Stearinsäure, Isostearinsäure, Ölsäure, Elaidinsäure, Petroselinsäure, Linolsäure, Linolensäure, Elaeostearinsäure, Arachinsäure, Gadoleinsäure, Behensäure, Erucasäure Guerbetsäuren sowie deren technische Gemische, mit N,N-Dimethylaminoethylamin, N,N-Dimethylaminopropylamin, N,N-Diethylaminoethylamin und N,N-Diethylaminopropylamin, die mit Natriumchloracetat kondensiert werden. Bevorzugt ist der Einsatz eines Kondensationsproduktes von C_8/18-Kokosfettsäure-N,N-dimethylaminopropylamid mit Natriumchloracetat. Carboxyalkylation products of amidoamines which follow the formula (V) are also suitable ,

in which R ⁸ CO represents an aliphatic acyl radical having 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, y represents numbers from 1 to 3 and R ⁶ , R ⁷ , x and Y have the meanings given above. Typical examples are reaction products of fatty acids with 6 to 22 carbon atoms, namely caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, paimitic acid, palmoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, elaeostearic acid, erasic acid, erachic acid, arachic acid Guerbet acids and their technical mixtures, with N, N-dimethylaminoethylamine, N, N-dimethylaminopropylamine, N, N-diethylaminoethylamine and N, N-diethylaminopropylamine, which are condensed with sodium chloroacetate. It is preferred to use a condensation product of C _8/18 coconut fatty acid N, N-dimethylaminopropylamide with sodium chloroacetate.

Imidazolines are also suitable starting materials for the betaines to be used in the context of the invention. These substances are also known substances which can be obtained, for example, by cyclizing condensation of 1 or 2 moles of fatty acid with polyhydric amines such as, for example, aminoethylethanolamine (AEEA) or diethylene triamine. The corresponding carboxyalkylation products are mixtures of different open-chain betaines. Typical examples are condensation products of the above-mentioned fatty acids with AEEA, preferably imidazolines based on lauric acid or again C _12/14 coconut fatty acid, which are subsequently betainized with sodium chloroacetate.

Alkyl and / or alkenyl oligoglycosides

In a particular embodiment of the invention, the anionic or amphoteric surfactants are dried together with nonionic surfactants of the alkyl and / or alkenyl oligoglycoside type which follow the formula (VI) , R ⁹ O- [G] _p (VI) in which R ^{9 represents} an alkyl and / or alkenyl radical having 4 to 22 carbon atoms, G represents a sugar radical having 5 or 6 carbon atoms and p represents numbers from 1 to 10. They can be obtained by the relevant methods of preparative organic chemistry, for example by acid-catalyzed acetalization of glucose with fatty alcohols. 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 oligo glucosides . The index number p in the general formula (VI) indicates the degree of oligomerization (DP), ie the distribution of mono- and oligoglycosides, and stands for a number between 1 and 10. While p must always be an integer in a given compound and especially here can assume the values p = 1 to 6, the value p for a certain alkyl oligoglycoside is an analytically determined arithmetic parameter, which usually represents a fractional number, alkyl and / or alkenyl oligoglycosides with an average degree of oligomerization p of 1.1 to 3 are preferred , 0 used. From an application point of view, preference is given to those alkyl and / or alkenyl oligoglycosides whose degree of oligomerization is less than 1.7 and in particular between 1.2 and 1.4.

The alkyl or alkenyl radical R ⁹ can be derived from primary alcohols having 4 to 11, preferably 8 to 10, carbon atoms. Typical examples are butanol, capronic alcohol, caprylic alcohol, capric alcohol and undecyl alcohol and their technical mixtures, such as are obtained, for example, in the hydrogenation of technical fatty acid methyl esters or in the course of the hydrogenation of aldehydes from Roelen's oxosynthesis. Alkyl oligoglucosides of chain length C ₈ -C ₁₀ (DP = 1 to 3) are preferred, which are obtained as a preliminary step in the separation of technical C ₈ -C ₁₈ coconut fatty alcohol by distillation and with a proportion of less than 6% by weight of C ₁₂ - Alcohol can be contaminated and alkyl oligoglucosides based on technical C _9/11 oxo alcohols (DP = 1 to 3). The alkyl or alkenyl radical R ⁹ 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, Guerbet alcohols, as described above, and the technical ones which can be obtained, as well as their Guerbet alcohols, as can be described above, as well as the technical Guerbet alcohols which can be obtained as well as their technical descriptions. Alkyl oligoglucosides based on hardened C _12/14 coconut alcohol with a DP of 1 to 3 are preferred.

The joint drying can take place in such a way that the aqueous pastes of the different Surfactants previously mixed, homogenized and then in the thin film evaporator brings in. However, it is also possible to meter in the pastes separately and to mix them in situational. The weight ratio between the anionic / amphoteric surfactants and alkyl and / or alkenyl oligoglycosides can - based on the detergent content - 10:90 to 90: 10, preferably 25: 75 to 75: 25. Mixtures of are particularly preferred Sulfosuccinates and alkyl oligoglucosides in a weight ratio of 40:60 to 60:40, which differ according to the Drying is ideal for the production of bar soaps.

Drying and granulating in the flash dryer

The simultaneous drying and granulation is carried out in a horizontally arranged thin-film evaporator or dryer with rotating internals, such as that sold by VRV under the name "Flashdryer" or by VOMM under the name "Turbodryer". In simple terms, this is a pipe that can be tempered at different temperatures across several zones. The paste-like feed material, which is metered in via a pump, is flung against the heated wall by means of one or more shafts, which are provided with blades or shares of flies as rotating internals, on which the drying takes place in a thin layer, typically 1 to 10 mm thick he follows. In the sense of the invention, it has proven to be advantageous to apply a temperature gradient from 130 (product inlet) to 20 ° C. (product discharge) to the thin-film evaporator. For this purpose, for example, the first two zones of the evaporator are heated to 120 to 130 ° C and the last are cooled to 20 ° C. The thin-film evaporator or dryer is operated at atmospheric pressure and gassed in countercurrent with air, but preferably with an alkaline gas stream, for example ammonia (throughput 50 to 150 m ³ / h). The gas inlet temperature is usually 20 to 30 ° C, the outlet temperature 90 to 110 ° C. The throughput of the surfactant pastes is of course dependent on the size of the dryer, for example is 5 to 25 kg / h. It is advisable to heat the pastes to 40 to 60 ° C. during the feed and to add 0.05 to 0.5% by weight, based on the solids content, of alkali carbonate, preferably sodium carbonate, to avoid hydrolysis processes.

Another preferred embodiment of the method according to the invention is that Mix aqueous surfactant on the hot contact surface with the already dried end product. For this purpose, a partial product flow of about 10 to 40, preferably 15 to 25% by weight, based on the Mass flow of the paste used - removed at the outlet of the dryer and using a Solid dosing screw in the immediate vicinity of the paste inlet is metered directly back into the apparatus. This measure makes it possible to reduce the stickiness of the aqueous surfactant and to improve it Wall contact of the product on the entire available surface to manufacture. As a result, the product transport is evened out and the product drying intensified. At the same time, the particle size distribution of the Granules specifically shifted to coarser products, i.e. the undesirable amount of fine dust is significant With this measure there is an increase in throughput based on analog process conditions without solids return.

After drying, it has also proven to be very advantageous, which is still around 50 to 70 ° C hot granules on a conveyor belt, preferably to give a vibrating trough or the like and there quickly, i.e. within a dwell time of 20 to 60 s, with ambient air at temperatures of cool about 30 to 40 ° C. To further improve resistance to unwanted The granules of particularly hygroscopic surfactants can also be absorbed subsequently powder by adding 0.5 to 2% by weight of silica,

Industrial applicability

The granules obtainable by the process according to the invention can then be combined with others Ingredients of powdered surface-active agents, such as tower powders for Detergent can be mixed. It is also possible to easily mix the powders in aqueous preparations to incorporate. In fact, when using the powder compared to the aqueous starting pastes no differences in the application properties were observed. Even in Bar soaps of the combibar or syndet type, toothpastes or for the production of emulsifiers for the The emulsion can be polymerized, for example, together with fatty acids, fatty acid salts, Incorrectly incorporate fatty alcohols, starch, polyglycols and the like.

Examples Examples 1 to 5

The granules were produced in a flash dryer from VRV SpA, Milan / IT. It was a horizontally arranged thin film evaporator (length 1100 mm, inside diameter: 155 mm) with 4 shafts and 22 blades, the distance to the wall of which was 2 mm. The dryer had three separate heating or cooling zones and a total heat exchanger area of 0.44 m ² . The operation was carried out at normal pressure. A vibrating pump was used to pump aqueous surfactant pastes (solids content 70% by weight) with a throughput of 11.5 kg / h into the thin-film evaporator, the heating zones 1 and 2 of which were heated to 50 ° C and optionally added with 1% by weight sodium carbonate had been set to 125 ° C and its cooling zone 3 to 20 ° C. The speed of the rotors was 24 m / s. The flash dryer was gassed with air or an air / ammonia mixture 1: 1 (approx. 110 m ³ / h); the gas outlet temperature was approx. 65 ° C. The pre-dried, still about 60 ° C hot granules were placed on a vibrating trough (length 1 m), gassed with room air and cooled to about 40 ° C within 30 s. It was then powdered with about 1% by weight of silica (Sipernat® 50 S). A dry, pure-white granulate which was free-flowing and non-clumping, even after prolonged storage in the air, was obtained. The characteristics of the granulate are shown in Table 1. Characteristics of the Flashdryer granulate (percentages as% by weight) E.g. Surfactant paste Grain size distribution [%] in mm RW [%] SD [g / l] > 0.8 > 0.4 > 0.2 > 0.1 <0.1 1 Sodium lauryl sulfate 11.1 19.0 24.2 31.0 14.7 1.3 610 2 Sodium Laureth Sulfate 11.8 21.0 26.3 35.5 5.4 1.2 615 3rd Sodium Laureth Sulfosuccinate 12.0 13.4 27.1 34.0 13.5 1.3 620 4th Cocoamidopropyl betaines 12.2 12.7 23.5 33.7 17.9 1.3 610 5 Sodium Laureth Sulfosuccinate / Coco Glucosides (1: 1) 11.9 12.5 22.9 32.7 20.0 1.3 600

Examples 6 to 11

Analogous to Example 1, alkyl sulfate pastes were dried. However, a partial product stream (examples 7, 8 and 11) was removed at the outlet of the dryer and metered back into the apparatus using a solid dosing screw in the immediate vicinity of the paste inlet. The results are summarized in Table 2. Drying AS pastes with product return (percentages as% by weight) parameter 6 7 8th 9 10th 11 Feed material 1 1 1 2 2 2 Drying temperature [° C] 128 Volume flow paste [kg / h] 8.5 11.5 13.5 8.5 11.3 11.3 Fixed flow rate [kg / h] - 3.5 1.7 - - 1.7 Final product water content [%] 0.4 0.4 0.4 0.7 1.3 1.0 Bulk density [g / l] 557 593 654 657 Grain spectrum [%] > 0.8 mm 11.1 29.4 0.8 0.7 > 0.4 mm 19.0 30.2 3.0 9.1 > 0.2 mm 24.2 23.9 7.2 19.7 > 0.1 mm 31.0 13.1 32.2 45.7 <0.1 mm 14.7 3.4 56.8 24.8 1) Coconut alkyl sulfate sodium salt, 35 wt .-% active substance 2) Lauryl sulfate sodium salt, 35% by weight of active substance

Examples 6 to 8 show that with a constant water content of the end product, the throughput of paste from 8.5 to 13.5 kg / h could be increased if the powder recycling was used, The amount returned could be varied within a wide range (Examples 7 and 8). The Product according to Example 8 is significantly coarser than Example 1. Examples 9 and 10 show that an increase in throughput without powder recycling leads to an increase in the product water content can lead from 0.7 to 1.3% by weight. The powder recycling (example 11) reduced the product moisture and again led to powders with less dust.

Claims (10)

1. A process for the production of solid detergent raw materials by simultaneous drying and granulation of water-containing pastes of anionic and/or amphoteric surfactants in a horizontal thin-layer evaporator or dryer with rotating internals, characterized in that drying is carried out at a temperature of 120 to 130°C.
2. A process as claimed in claim 1, characterized in that aqueous pastes of anionic and/or amphoteric surfactants selected from the group consisting of soaps, alkyl benzenesulfonates, alkane sulfonates, olefin sulfonates, alkyl ether sulfonates, glycerol ether sulfonates, α-methyl ester sulfonates, sulfofatty acids, alk(en)yl sulfates, alk(en)yl ether sulfates, glycerol ether sulfates, hydroxy mixed ether sulfates, monoglyceride (ether) sulfates, fatty acid amide (ether)sulfates, mono- and dialkyl sulfosuccinates, mono- and dialkyl sulfosuccinamates, sulfotriglycerides, amide soaps, ether carboxylic acids and salts thereof, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, N-acyl amino acids, alkyl oligoglucoside sulfates, protein fatty acid condensates, alkyl (ether)phosphates alkyl betaines, alkyl amidobetaines, aminopropionates, aminoglycinates, imidazolinium betaines and sulfobetaines are used.
3. A process as claimed in claims 1 and 2, characterized in that aqueous pastes of alkyl and/or alkenyl sulfates corresponding to formula (I): R ¹ O-SO ₃ X   (I) where R¹ is a linear or branched, aliphatic alkyl and/or alkenyl group containing 6 to 22 and preferably 12 to 18 carbon atoms and X is an alkali metal and/or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium, are used.
4. A process as claimed in claims 1 to 3, characterized in that aqueous pastes of alkyl ether sulfates corresponding to formula (II): R ² O-(CH ₂ CH ₂ O) _m SO ₃ X   (II) where R² is a linear or branched alkyl and/or alkenyl group containing 6 to 22 carbon atoms, m is a number of 1 to 10 and X is an alkali and/or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium, are used.
5. A process as claimed in claims 1 to 4, characterized in that aqueous pastes of sulfosuccinates corresponding to formula (III):

   

   where R³ is an alkyl and/or alkenyl group containing 6 to 22 carbon atoms, R⁴ has the same meaning as R³ or X, p and q independently of one another stand for 0 or for numbers of 1 to 10 and X is an alkali metal or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium, are used.
6. A process as claimed in claims 1 to 5, characterized in that aqueous pastes of betaines corresponding to formula (IV):

   

   in which R⁵ represents alkyl and/or alkenyl groups containing 6 to 22 carbon atoms, R⁶ represents hydrogen or alkyl groups containing 1 to 4 carbon atoms, R⁷ represents alkyl groups containing 1 to 4 carbon atoms, x is a number of 1 to 6 and Y is an alkali metal and/or alkaline earth metal or ammonium, are used.
7. A process as claimed in claims 1 to 6, characterized in that betaines corresponding to formula (V):

   

   where R⁸CO is an aliphatic acyl group containing 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, y is a number of 1 to 3 and R⁶, R⁷, x and Y are as defined above, are used.
8. A process as claimed in claims 1 to 7, characterized in that drying is carried out in the presence of an alkaline gas stream.
9. A process as claimed in claims 1 to 8, characterized in that drying is carried out in the presence of alkali metal carbonates.
10. A process as claimed in claims 1 to 9, characterized in that the water-containing surfactant paste is back-mixed with already dried end product on the hot contact surface.