WO2000053713A1 - Granulation method - Google Patents

Abstract

Disclosed is a novel granulation method. A surfactant foam is obtained by foaming a free-flowing component that contains anionic surfactant acid with a gaseous medium. Said surfactant foam is used as granulation auxiliary and is preferably provided with mean pore sizes less than 10 mm, preferably less than 5 mm and especially less than 2 mm.

Description

 "Granulation process"

The present invention relates to a method for producing surfactant granules. In particular, it relates to a process which allows surfactant granules or surfactant-containing components of detergent and cleaning agent compositions or complete detergent and cleaning agent compositions to be produced without or with reduced use of spray drying steps.

Granular detergent and cleaning agent compositions or components therefor are largely produced by spray drying. In spray drying, the ingredients such as surfactants, builders, etc. are mixed with about 35 to 50% by weight of water to form an aqueous slurry, the so-called slurry, and atomized in spray towers in a hot gas stream, the detergent and cleaning agent particles form. Both the plants for this process and the implementation of the process are costly, since most of the slurry water has to be evaporated in order to obtain particles with residual water contents of around 5 to 10% by weight. In addition, the granules produced by spray drying usually have excellent solubility, but only have low bulk densities, which leads to higher packaging volumes and transport and storage capacities. The flowability of spray-dried granules is also not optimal due to their irregular surface structure, which also affects their visual appearance. Spray drying processes have a further series of disadvantages, so that there has been no lack of attempts to carry out the production of detergents and cleaning agents completely without spray drying or to have at least the smallest possible proportion of spray drying products in the finished product. For example, W. Hermann de Groot, I. Adami, GF Moretti "The Manufacture of Modern Detergent Powders", Hermann de Groot Academic Publisher, Wassenaar, 1995, page 102 ff. Describes various mixing and granulating processes for the production of detergents and cleaning agents. These processes have in common that premixed solids are granulated with the addition of the liquid ingredients and, if necessary, subsequently dried.

There is also a broad state of the art in the patent literature for the non-tower manufacture of detergents and cleaning agents. Many of these processes are based on the acid form of the anionic surfactants, since this surfactant class represents the largest proportion of wash-active substances in terms of quantity and the anionic surfactants occur in the course of their production in the form of the free acids which have to be neutralized to the corresponding salts.

A new way of producing surfactant granules, which avoids the disadvantages of the known processes, is foam granulation, which is described in the older German patent applications DE 198 44 523.7, DE 198 44 522.9 and DE 198 55 380.3 (all Henkel KGaA).

DE 198 44 523.7 discloses a process for the production of surfactant granules, in which an anionic surfactant in its acid form and a highly concentrated, aqueous alkaline component are separately charged with a gaseous medium, then combined and neutralized, and both the anionic surfactant in its acid form and that Highly concentrated, aqueous alkaline component is foamed by the gaseous medium and the acidic and alkaline foams formed are combined to form a neutralized foam, which is subsequently added to a solid bed placed in a mixer. According to the teaching of this document, two foams (an acidic and an alkaline foam) are combined and the neutralized foam is used as a granulation aid for solids. The older German patent application DE 198 44 522.9 discloses a foam granulation process in which the foam serving as a granulation aid is not formed by combining an acidic and an alkaline foam. Rather, a method for producing surfactant granules is disclosed in which a gaseous medium is applied to a surfactant-containing flowable component, the surfactant-containing flowable component being foamed by the gaseous medium and the resulting surfactant-containing foam subsequently being added to a solid bed placed in a mixer. According to the information in this document, nonionic surfactants or the salts of anionic surfactant acids can be used as flowable components containing surfactants. Nothing is mentioned in this document about the use of anionic surfactant acids in the form of a foam.

Foam granulation processes with foamed anionic surfactant acid are disclosed in the older German patent application DE 198 55 380.3. The subject of this document is a process for the production of surfactant granules, in which an anionic surfactant in its acid form is neutralized and granulated with a solid neutralizing agent, the solid neutralizing agent being added to the anionic surfactant in its acidic form and being foamed into a neutralized foam, which is subsequently mixed in one Mixer submitted solid bed is given. This forms the neutral-reacting foam, which acts as a granulation aid, from the anionic surfactant acid and the solid neutralizing agent. A method in which an acidic surfactant-containing foam serves as a granulation aid is also not described in this document.

The present invention was based on the object of further developing the field of foam granulation and of providing a method which makes it possible to produce surfactant granules for detergents and cleaning agents without or with reduced use of spray drying steps, and to start directly from the acid form of the anionic surfactants. The drying of the granules formed should preferably also be completely dispensable. The present invention relates to a process for the production of surfactant granules, in which a surfactant-containing flowable component is acted upon and foamed up and the resulting surfactant-containing foam is subsequently added to a solid bed placed in a mixer and the surfactant-containing flowable component contains anionic surfactant acid (s) .

In contrast to the prior art cited above, an acid foam, i.e. a foam with a pH below 7, used as a granulation aid. In preferred variants of the process according to the invention, the solid bed to be granulated has alkaline ingredients, so that a neutralization reaction takes place during the granulation process. Here, the procedure according to the invention has the advantage over the well-known addition of anionic surfactant acids in liquid form that the acid is gently added to the mixer and is distributed very homogeneously. The formation of coarse clumps or the appearance of acid esters, which can lead to discoloration of the granules and undesirable reactions with sensitive ingredients (e.g. perfume) of the ready-made detergent and cleaning agent, is thus effectively avoided.

The term "foam" used in the context of the present invention denotes structures made of gas-filled, spherical or polyhedral cells (pores) which are delimited by liquid, semi-liquid or highly viscous cell webs.

If the volume concentration of the gas forming the foam is less than 74% with homodisperse distribution, the gas bubbles are spherical because of the surface-reducing effect of the interfacial tension. Above the limit of the densest spherical packing, the bubbles are deformed into polyhedral lamellae, which are delimited by approximately 4-600 nm thin membranes. The cell bridges, connected via so-called nodes, form a coherent framework. The foam lamellae (closed-cell foam) stretch between the cell bars. If the foam lamellae are destroyed or flow back into the cell webs at the end of foam formation, an open-cell foam is obtained. Foams are thermodynamically unstable, because by reducing the upper surface energy can be obtained. The stability and thus the existence of the foams according to the invention therefore depends on the extent to which their self-destruction can be prevented.

To generate the foam, the gaseous medium is blown into the flowable component containing anionic surfactant acid, or the foaming is achieved by vigorous beating, shaking, spraying or stirring the liquid in the relevant gas atmosphere. Due to the lighter and easier to control and carry out foaming, foam generation by blowing in the gaseous medium (“gassing”) is clearly preferred over the other variants in the context of the present invention. Depending on the desired process variant, gassing is carried out continuously or discontinuously via perforated plates, sintered disks, sieve inserts, venturi nozzles or other conventional systems.

Any gases or gas mixtures can be used as the gaseous medium for foaming. Examples of gases used in industry are nitrogen, oxygen, noble gases and noble gas mixtures, carbon dioxide etc. For reasons of cost, the process according to the invention is preferably carried out with air as the gaseous medium.

The process according to the invention includes the independent substeps of the production of foam from a flowable component containing anionic surfactant acid and the subsequent addition to a solid bed moved in a mixer, the foam serving as a granulation aid. The ingredients of the surfactant-containing foam produced in the first step are described below.

The surfactant-containing flowable component contains at least surface-active substances from the group of anionic surfactants, which are at least partially present in their acid form, ie not neutralized. In addition, the surfactant-containing flowable component can contain further surface-active compounds from the groups of anionic, nonionic, zwitterionic or cationic surfactants. The salary of the flowable surfactant-containing component of surfactant (s) can vary within wide limits. According to the invention, processes are preferred in which the surfactant-containing flowable component contains one or more anionic surfactant acid (s) in amounts of from 20 to 100% by weight, preferably from 50 to 95% by weight and in particular from 60 to 90% by weight, each based on the surfactant-containing component.

The process according to the invention comprises the independent substeps of producing foam from an anionic surfactant in its acid form on the one hand and adding it to a solid bed moved in a mixer on the other. The most important anionic surfactant acids which can be used according to the invention are described below.

Anionic surfactants in acid form are preferably one or more substances from the group of carboxylic acids, sulfuric acid half-esters and sulfonic acids, preferably from the group of fatty acids, fatty alkyl sulfuric acids and alkylarylsulfonic acids. In order to have sufficient surface-active properties, the compounds mentioned should have longer-chain hydrocarbon radicals, that is to say they should have at least 6 carbon atoms in the alkyl or alkenyl radical. The C chain distributions of the anionic surfactants are usually in the range from 6 to 40, preferably 8 to 30 and in particular 12 to 22 carbon atoms.

Carboxylic acids, which are used as soaps in detergents and cleaning agents in the form of their alkali metal salts, are technically largely obtained from native fats and oils by hydrolysis. While the alkaline saponification which was carried out in the past century led directly to the alkali salts (soaps), only water is used on an industrial scale to split the fats into glycerol and the free fatty acids. Large-scale processes are, for example, cleavage in an autoclave or continuous high-pressure cleavage. Carboxylic acids which can be used as an anionic surfactant in acid form in the context of the present invention are, for example, hexanoic acid (caproic acid), heptanoic acid (enanthic acid), octanoic acid (caprylic acid), nonanoic acid (pelargonic acid), decanoic acid (capric acid), undecanoic acid, etc. Preference is given to the present invention Connection the use of fatty acids such as dodecanoic acid (lau- rinic acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), eicosanoic acid (arachic acid), docosanoic acid (behenic acid), tetracosanoic acid (lignoceric acid), hexacosanoic acid (cerotinic acid), and triacotanoic acid unsaturated species 9c-hexadecenoic acid (palmitoleic acid), 6c-octadecenoic acid (petroselinic acid), 6t-octadecenoic acid (petroselaidic acid), 9c-octadecenoic acid (oleic acid), 9t-octadecenoic acid ((elaidinic acid), 9c, 12c-octadecenoic acid) (9c -Octadecadienoic acid (linolaidic acid) and 9c, 12c, 15c- octadecatreic acid (linolenic acid) .For reasons of cost, it is preferred not to use the pure species, but rather technical mixtures of the individual acids, as can be obtained from fat cleavage. approx. 6% by weight C ", 6% by weight C ₁₀ , 48% by weight C ₁₂ , 18% by weight C ₁₄ , 10% by weight C ₁₆ , 2% by weight C _Ig , 8 wt% C, _g , 1 Ge w .-% C _18), palm kernel oil fatty acid (about 4 wt .-% C _8, 5 Ge .-% C _I0, 50 wt .-% _C12, 15 wt .-% C _14, 7 wt .-% C , ₆ , 2 wt% C ₁₈ , 15 wt% C ₁₈ , 1 wt% C _lg ), tallow fatty acid (approx. 3 wt .-% C _l4, 26 wt .-% C _16, 2 Ge .-% C _16, 2 wt .-% C _17, 17 Ge .-% C _lg, 44 wt .-% C _18, 3 wt % C, _g , 1% by weight C _lg ), hardened tallow fatty acid (approx. 2% by weight C ₁₄ , 28% by weight C ₁₆ , 2% by weight C, ₇ , 63% by weight) % C ₁₈ , 1% by weight C ₁₈ ), technical oleic acid (approx. 1% by weight C ₁₂ , 3% by weight C ₁₄ , 5% by weight C ₁₆ , 6% by weight C ₁₆ , 1% by weight of C ₁₇ , 2% by weight of C _{I g} , 70% by weight of C ₁₈ , 10% by weight of C _lg , 0.5% by weight of C ₁₈ ), technical-grade palmitin / stearic acid (approx. 1 wt% C ₁₂ , 2 wt% C ₁₄ , 45 wt% C ₁₆ , 2 wt% C ₁₇ , 47 wt% C ₁₈ , 1 wt% C ₁₈ ) and soybean oil _{fatty acid} (approx. 2% by weight C ₁₄ , 15% by weight C _I5 , 5% by weight C _I8 , 25% by weight C ₁₈ , 45% by weight C ₁₈ , 7% by weight % C, ₈ ).

Sulfuric acid semiesters of longer-chain alcohols are also anionic surfactants in their acid form and can be used in the process according to the invention. Their alkali metal, in particular sodium salts, the fatty alcohol sulfates, are commercially available from fatty alcohols which are reacted with sulfuric acid, chlorosulfonic acid, amidosulfonic acid or sulfur trioxide to give the alkyl sulfuric acids concerned and are subsequently neutralized. The fatty alcohols are obtained from the fatty acids or fatty acid mixtures concerned by high-pressure hydrogenation of the fatty acid methyl esters. The most significant industrial process in terms of quantity for the production of fatty alkyl sulfuric acids is the sulfonation of alcohols with SO ₃ / air mixtures in special cascade, falling film or tube bundle reactors.

Another class of anionic surfactant acids which can be used in the process according to the invention are the alkyl ether sulfuric acids, the salts of which, the alkyl ether sulfates, are distinguished by a higher water solubility and lower sensitivity to water hardness (solubility of the Ca salts) compared to the alkyl sulfates. Like the alkyl sulfuric acids, alkyl ether sulfuric acids are synthesized from fatty alcohols, which are reacted with ethylene oxide to give the fatty alcohol ethoxylates in question. Instead of ethylene oxide, propylene oxide can also be used. The subsequent sulfonation with gaseous sulfur trioxide in short-term sulfonation reactors yields over 98% of the alkyl ether sulfuric acids concerned.

Alkanesulfonic acids and olefin sulfonic acids can also be used as anionic surfactants in acid form in the context of the present invention. Alkanesulfonic acids can contain the sulfonic acid group in a terminal bond (primary alkanesulfonic acids) or along the C chain (secondary alkanesulfonic acids), only the secondary alkanesulfonic acids being of commercial importance. These are produced by sulfochlorination or sulfoxidation of linear hydrocarbons. In the sulfochlorination according to ReeJ, n-paraffms with sulfur dioxide and chlorine are converted to the corresponding sulfochlorides under irradiation with UV light, which give the alkanesulfonates directly when hydrolysed with alkalis, and the alkanesulfonic acids when reacted with water. Since di- and polysulfochlorides and chlorinated hydrocarbons can occur as by-products of the radical reaction in the sulfochlorination, the reaction is usually only carried out up to degrees of conversion of 30% and then terminated.

Another process for the production of alkanesulfonic acids is sulfoxidation, in which n-paraffms are reacted with sulfur dioxide and oxygen under irradiation with UV light. This radical reaction produces successive alkylsulfonyl radicals, which react further with oxygen to form the alkylpersulfonyl radicals. The reaction with unreacted paraffin gives an alkyl radical and the alkyl persulfonic acid, which are converted into an alkyl peroxysulfonyl radical and a hydroxyl radical decays. The reaction of the two radicals with unreacted paraffin gives the alkylsulfonic acids or water, which reacts with alkylpersulfonic acid and sulfur dioxide to give sulfuric acid. In order to keep the yield of the two end products alkylsulfonic acid and sulfuric acid as high as possible and to suppress side reactions, this reaction is usually carried out only up to degrees of conversion of 1% and then stopped.

Olefin sulfonates are produced industrially by reacting olefins with sulfur trioxide. Intermediate hermaphrodites form here, which cyclize to form so-called sultans. Under suitable conditions (alkaline or acidic hydrolysis), these sultones react to give hydroxylalkanesulfonic acids or alkenesulfonic acids, both of which can also be used as anionic surfactant acids.

Alkylbenzenesulfonates as powerful anionic surfactants have been known since the 1930s. At that time, alkyl benzenes were produced by monochlorination of kogasin fractions and subsequent Friedel-Crafts alkylation, which were sulfonated with oleum and neutralized with sodium hydroxide solution. In the early 1950s, to produce alkylbenzenesulfonates, propylene was tetramerized to give branched α-dodecylene and the product was converted to a tetrapropylenebenzene via a Friedel-Crafts reaction using aluminum tri chloride or hydrogen fluoride, which was subsequently sulfonated and neutralized. This economical possibility of producing tetrapropylene benzene sulfonates (TPS) led to the breakthrough of this class of surfactants, which subsequently displaced the soaps as the main surfactant in washing and cleaning agents.

Due to the lack of biodegradability of TPS, there was a need to produce new alkylbenzenesulfonates that are characterized by improved ecological behavior. These requirements are met by linear alkylbenzenesulfonates, which today are almost exclusively alkylbenzenesulfonates and are given the abbreviation ABS.

Linear alkylbenzenesulfonates are made from linear alkylbenzenes, which in turn are accessible from linear olefins. Large-scale petroleum Fractions with molecular sieves separated into the n-paraffms of the desired purity and dehydrated to the n-olefins, resulting in both α- and i-olefins. The resulting olefins are then reacted with benzene in the presence of acidic catalysts to give the alkylbenzenes, the choice of the Friedel-Crafts catalyst having an influence on the isomer distribution of the linear alkylbenzenes formed: when using aluminum trichloride, the content of the 2-phenyl Isomers in the mixture with the 3, 4, 5 and other isomers at approx. 30% by weight, but if hydrogen fluoride is used as a catalyst, the content of 2-phenyl isomer can be reduced to approx. 20% by weight. % reduce. Finally, the sulfonation of linear alkylbenzenes is now possible on a large industrial scale with oleum, sulfuric acid or gaseous sulfur trioxide, the latter being by far the most important. For the sulfonation, special film or tube bundle reactors are used which deliver a 97% by weight alkylbenzenesulfonic acid (ABSS) as product which can be used as anionic surfactant acid in the context of the present invention.

By choosing the neutralizing agent, a wide variety of salts, i.e. Alkylbenzenesulfonates. For reasons of economy, it is preferred to prepare and use the alkali metal salts and, among them, the sodium salts of the ABSS. These can be described by the general formula I:

in which the sum of x and y is usually between 5 and 13. Processes according to the invention in which C ₈ . ₁₆ -, preferably C ₉ . ₁₃ - _{Alkylbenzenesulfonic} acids are used are preferred. In the context of the present invention, it is further preferred C ₈ . ₁₆ -, preferably C ₉ . _13- alkylbenzenesulfonic acids to be used, which are derived from alkylbenzenes which have a tetralin content below 5% by weight, based on the alkylbenzene. It is further preferred to use alkylbenzenesulfonic acids whose alkylbenzenes have been prepared by the HF process, so that the C ₈ . ₁₆ -, preferably C ₉ . _13- Alkylbenzenesulfonic acids have a 2-phenyl isomer content below 22% by weight, based on the alkylbenzenesulfonic acid.

The above-mentioned anionic surfactants in their acid form can be used and foamed alone or in a mixture with one another in the process according to the invention. However, it is also possible and preferred that the anionic surfactant in acid form, before foaming, contains further, preferably acidic, ingredients of detergents and cleaning agents in amounts of 0.1 to 40% by weight, preferably 1 to 15% by weight and in particular from 2 to 10% by weight, based in each case on the weight of the mixture to be foamed.

According to the invention, methods are preferred in which the surfactant-containing flowable component alkylbenzenesulfonic acids in amounts of 20 to 99% by weight, preferably 30 to 95% by weight and in particular 40 to 90% by weight, in each case based on the surfactant-containing component, contains.

Suitable acidic reactants in the context of the present invention are, in addition to the "surfactant acids", the fatty acids, phosphonic acids, polymer acids or partially neutralized polymer acids as well as "builder acids" and "complex builder acids" (details later in the text) alone or in any mixtures. As ingredients in washing and cleaning agents; The anionic surfactant acid that can be mixed in before foaming is particularly suitable for acidic detergent and cleaning agent ingredients, for example phosphonic acids, which in neutralized form (phosphonates) are components of many detergents and cleaning agents as incrustation inhibitors. The use of (partially neutralized) polymer acids such as, for example, polyacrylic acids is also possible according to the invention. However, it is also possible to mix acid-stable ingredients with the anionic surfactant acid before foaming. Here offer themselves For example, so-called small components, which would otherwise have to be added in complex further steps, for example optical brighteners, dyes, etc., the acid stability being checked in individual cases.

In preferred processes, the surfactant-containing flowable component additionally contains fatty acids and / or soaps in amounts of 1 to 30% by weight, preferably 2 to 25% by weight and in particular 5 to 20% by weight, in each case based on the surfactant-containing component Component.

Optionally, nonionic surfactants can be obtained in amounts of 0.1 to 60% by weight, preferably 0.5 to 55% by weight and in particular 2.5 to 10% by weight, of the anionic surfactant in acid form before foaming to the weight of the mixture to be foamed. This additive can improve the physical properties of the anionic surfactant foam and make subsequent incorporation of nonionic surfactants into the surfactant granules or the entire detergent and cleaning agent unnecessary. The different representatives from the group of nonionic surfactants are described below. In preferred processes, the surfactant-containing flowable component additionally contains nonionic surfactant (s) in amounts of 1 to 50% by weight, preferably 2 to 40% by weight and in particular 5 to 30% by weight, based in each case on the surfactant-containing component.

The nonionic surfactants used are preferably alkoxylated, advantageously ethoxylated, in particular primary alcohols having preferably 8 to 18 carbon atoms and an average of 1 to 12 moles of ethylene oxide (EO) per mole of alcohol in which the alcohol radical has a methyl or linear branching in the 2-position may be or may contain linear and methyl-branched radicals in the mixture, as are usually present in oxo alcohol radicals. However, alcohol ethoxylates with linear residues of alcohols of native origin with 12 to 18 carbon atoms, for example from coconut, palm, tallow or oleyl alcohol, and an average of 2 to 8 EO per mole of alcohol are particularly preferred. The preferred ethoxylated alcohols include, for example, C _{] 2} . ₁₄ - alcohols with 3 EO or 4 EO, C ₉ _ _u alcohol with 7 EO, C _l3 . ₁₅ alcohols with 3 EO, 5 EO, 7 EO or 8 EO, C ₁₂ _ ₁₈ - alcohols with 3 EO, 5 EO or 7 EO and mixtures thereof, such as mixtures of C _12-14 - alcohol with 3 EO and C ₁₂ . ₁₈ alcohol with 5 EO. The degrees of ethoxylation given represent statistical averages, which can be an integer or a fraction for a specific product. Preferred alcohol ethoxylates have a narrow homolog distribution (narrow range ethoxylates, NRE). In addition to these nonionic surfactants, fatty alcohols with more than 12 EO can also be used. Examples of this are tallow fatty alcohol with 14 EO, 25 EO, 30 EO or 40 EO.

The use of alkoxylated nonionic surfactants is preferred in the context of the present invention. Process variants in which the surfactant-containing flowable component alkoxylated, preferably ethoxylated nonionic surfactants in amounts of 20 to 90 wt .-%, preferably from 30 to 85 wt .-% and in particular from 40 to 80 wt .-%, each based on the surfactant-containing component contains, besides, have advantages, which methods are particularly preferred in which the surfactant-containing flowable component as ethoxylated nonionic surfactants are the reaction products of C ₈ _ ₂₂ fatty alcohols, preferably, C _20/12 fatty alcohols and especially C _14:18 fatty alcohols with 1 up to 30 moles of ethylene oxide, preferably 2 to 20 moles of ethylene oxide and in particular 5 to 10 moles of ethylene oxide, in amounts of 10 to 80% by weight, preferably 20 to 75% by weight and in particular 30 to 70% by weight, each based on the surfactant-containing component.

Another class of preferably used nonionic surfactants, which are used either as the sole nonionic surfactant or in combination with other nonionic surfactants, are alkoxylated, preferably ethoxylated or ethoxylated and propoxylated fatty acid alkyl esters, preferably with 1 to 4 carbon atoms in the alkyl chain, in particular Fatty acid methyl esters as described, for example, in Japanese patent application JP 58/217598 or which are preferably prepared by the process described in international patent application WO-A-90/13533.

Another class of nonionic surfactants that can be used advantageously are the alkyl polyglycosides (APG). Alkypolyglycosides that can be used satisfy the general NEN formula RO (G) _z , in which R represents a linear or branched, in particular methyl-branched, saturated or unsaturated, aliphatic radical having 8 to 22, preferably 12 to 18 carbon atoms and G is the symbol which stands for a glycose unit with 5 or 6 carbon atoms, preferably for glucose. The degree of glycosidation z is between 1.0 and 4.0, preferably between 1.0 and 2.0 and in particular between 1.1 and 1.5.

Linear alkyl polyglucosides, ie alkyl polyglycosides, in which the polyglycosyl radical is a glucose radical and the alkyl radical is an n-alkyl radical are preferably used.

The surfactant granules according to the invention can preferably contain alkyl polyglycosides, with APG contents of the granules above 0.2% by weight, based on the total granules, being preferred. Particularly preferred surfactant granules contain APG in amounts of 0.2 to 10% by weight, preferably 0.2 to 5% by weight and in particular 0.5 to 3% by weight.

Nonionic surfactants of the amine oxide type, for example N-coconut alkyl-N, N-dimethylamine oxide and N-tallow alkyl-N, N-dihydroxyethylamine oxide, and the fatty acid alkanolamides can also be suitable. The amount of these nonionic surfactants is preferably not more than that of the ethoxylated fatty alcohols, in particular not more than half of them.

Other suitable surfactants are polyhydroxy fatty acid amides of the formula (I),

R ^]

R-CO-N- [Z] (I)

in which RCO stands for an aliphatic acyl radical with 6 to 22 carbon atoms, R for hydrogen, an alkyl or hydroxyalkyl radical with 1 to 4 carbon atoms and [Z] for a linear or branched polyhydroxyalkyl radical with 3 to 10 carbon atoms and 3 to 10 hydroxyl groups. The polyhydroxy fatty acid amides are known substances which can usually be obtained by reductive amination of a reducing sugar with ammonia, an alkylamine or an alkanolamine and subsequent acyl rank with a fatty acid, a fatty acid alkyl ester or a fatty acid chloride.

The group of polyhydroxy fatty acid amides also includes compounds of the formula (II)

R ^! -OR ^2nd

R-CO-N- [Z] (II)

in which R represents a linear or branched alkyl or alkenyl radical having 7 to 12 carbon atoms, R ^{1 represents} a linear, branched or cyclic alkyl radical or an aryl radical having 2 to 8 carbon atoms and R ^{2 represents} a linear, branched or cyclic alkyl radical or is an aryl radical or an oxyalkyl radical having 1 to 8 carbon atoms, where C,. ₄ -alkyl or phenyl radicals are preferred and [Z] represents a linear polyhydroxyalkyl radical whose alkyl chain is substituted by at least two hydroxyl groups, or alkoxylated, preferably ethoxylated or propoxylated derivatives of this radical.

[Z] is preferably obtained by reductive amination of a reduced sugar, for example glucose, fractose, maltose, lactose, galactose, mannose or xylose. The N-alkoxy- or N-aryloxy-substituted compounds can then, for example according to the teaching of international application WO-A-95/07331, be converted into the desired polyhydroxy fatty acid amides by reaction with fatty acid methyl esters in the presence of an alkoxide as catalyst.

In preferred processes according to the invention, the surfactant-containing flowable component contains alkoxylated, preferably ethoxylated, nonionic surfactants, preferably the reaction products of C ₈ . ₂₂ fatty alcohols, preferably C _{] 2} . ₂₀ fatty alcohols and special C ₁₄ . ₁₈ fatty alcohols with 1 to 30 moles of ethylene oxide, preferably 2 to 20 moles of ethylene oxide and in particular 5 to 10 moles of ethylene oxide.

According to the invention, the surfactant-containing flowable component can consist entirely of one or more surfactants and thus be free of non-surfactant compounds. According to the invention, however, it is also possible to incorporate further ingredients of detergents and cleaning agents into the surfactant-containing component. In addition to active and active substances, the surfactant-containing component can also contain water due to the production process, this water also being able to be added to adjust advantageous viscosity values or to optimize the foaming process of the surfactant-containing component. In preferred processes, however, the surfactant-containing flowable component contains less than 20% by weight, preferably less than 15% by weight and in particular less than 10% by weight of water, in each case based on the surfactant-containing component.

In particular, so-called “small components” can advantageously be introduced into the surfactant granules using the foam used as the granulating liquid. In preferred processes according to the invention the surfactant-containing flowable component contains further ingredients of detergents and cleaning agents, in particular substances from the group of complexing agents, polymers, optical brighteners, colorants and fragrances and alkalis. These small components, which are preferably added to the surfactant-containing flowable component, are described below.

Depending on the desired properties of the foam, the flowable surfactant-containing component can be foamed at room temperature or with cooling or heating. Preferred process variants are carried out so that the surfactant-containing flowable component to be foamed has temperatures of 20 to 120 ° C., preferably 30 to 90 ° C. and in particular 50 to 75 ° C., before the foaming. Through the selection of the ingredients, the viscosity of the surfactant-containing component can be varied within wide limits, with thinner surfactant-containing components generally providing less stable foams. As already mentioned above, it is an advantage of the process according to the invention that, in contrast to conventional granulation processes, granulation liquids whose viscosity is high can also be used. Thus, surfactant-containing liquid components can be used in the process according to the invention, the viscosity of which is above 100 mPas, but also liquid components with viscosities above 1000 mPas, even above 5000 mPas, can be foamed according to the invention and can be used without problems as granulation aids in the form of the "granulation foam".

The flowable surfactant-containing component is foamed into a foam by the gaseous medium, it being possible for liquid and gaseous medium to be used in varying amounts or ratios to one another. From a process engineering point of view, it is preferred to use the gaseous medium in each case in amounts of at least 20% by volume, based on the amount of liquid to be foamed, for foam generation.

If, for example, one liter of a surfactant-containing component is to be foamed, at least 200 ml of gaseous medium are preferably used for foaming. In preferred processes, the amount of gaseous medium is significantly above this value, so that processes are preferred in which the amount of gas used for the foaming is one to three hundred times, preferably five to two hundred times, and in particular ten to one hundred times the volume of those to be foamed Amount of liquid. As already mentioned above, air is preferably used as the gaseous medium. However, it is also possible to use other gases or gas mixtures for foaming. For example, it may be preferred to pass air or oxygen-enriched air over an ozonizer before the gas is used for foaming. In this way it is possible to produce gas mixtures which contain, for example, 0.1 to 4% by weight of ozone. The ozone content of the foaming gas then leads to the oxidative destruction of undesirable components in the liquids to be foamed. In the case of partially discolored anionic surfactant acids in particular, a clear brightening can be achieved by adding ozone. 1 to 300 liters, preferably 5 to 200 liters and in particular 10 to 100 liters of air are thus preferably used for foaming the liter of the surfactant-containing component cited above by way of example.

The temperature of the foam formed can be controlled via the temperature of the liquid to be foamed on the one hand and the temperature of the gaseous medium on the other hand. In preferred variants of the process according to the invention, the resulting foam has temperatures below 115 ° C., preferably between 20 and 80 ° C. and in particular between 30 and 70 ° C.

The resulting foam, which is used as a granulation aid in the next process step, can be characterized by further physical parameters. For example, it is preferred that the foam have a density below 0.80 like ^"3 , preferably from 0.10 to 0.6 like ^{" 3,} and especially from 0.30 to 0.55 like ^"3. It is further preferred that the foam has average pore sizes below 10 mm, preferably below 5 mm and in particular below 2 mm.

The specified physical parameters of temperature, density and average pore size characterize the foam at the time it is created. However, the procedure is preferably chosen so that the foam also meets the criteria mentioned when it is added to the mixer.

Processes are possible in which the foam only fulfills one or two of the criteria mentioned when it is added to the mixer, but preferably both the temperature and the density and the pore size are in the ranges mentioned when the foam reaches the mixer .

After its formation, the foam is placed on a solid bed placed in a mixer, where it serves as a granulation aid. This process step can be carried out in a wide variety of mixing and granulating devices, and so on is described in detail below. The solid bed placed in the mixer can contain all substances used in detergents and cleaning agents. In this way, finished washing and cleaning agents can be produced with the method according to the invention. Usually, however, certain ingredients of washing and cleaning agents are not granulated in order to avoid undesirable reactions of these components with one another under the mechanical action of the granulating tools. Ingredients that are usually only added to the resulting surfactant granules afterwards, ie after a granulation, are, for example, bleaching agents, bleach activators, enzymes and foam inhibitors.

It is preferred that the surfactant granules produced according to the invention contain, in addition to the surfactant, substances which later act as active substances in the washing and cleaning agent. In preferred processes, the solid bed placed in the mixer therefore contains one or more substances from the group of builders, in particular the alkali metal carbonates, sulfates and silicates, the zeolites and the polymers.

In order to produce surfactant granules which can later be mixed with other components to form the finished washing and cleaning agent without undesirable reactions occurring, it is preferred according to the invention that the surfactant granules contain no residues of excess anionic surfactant acid (s). This can easily be achieved in that the solid bed placed in the mixer contains alkaline components which neutralize the anionic surfactant acids. Carbonates and hydrogen carbonates are particularly suitable here, but other alkaline components such as oxides, hydroxides etc. or organic neutralizing agents such as amines etc. can also be used. In processes preferred according to the invention, the solid bed placed in the mixer contains one or more substances from the group of alkali metal carbonates and / or hydrogen carbonates, preferably sodium carbonate, in an amount which is sufficient to neutralize the amount of acid supplied via the foam.

It is particularly preferred here if the solid bed placed in the mixer contains the alkaline components in an amount which is used to neutralize the foam imported quantity of acid is sufficient. If, for example, 2 moles of monobasic acid are introduced into the foam containing anionic surfactant acid, then at least 2 neutralization equivalents, ie for example 2 moles of NaOH or 1 mole of sodium carbonate, should be present in the solid bed. Processes according to the invention in which the solid bed contains more than the stoichiometric amount of bases required to neutralize the amount of acid introduced are preferred. It is particularly preferred if the solid bed contains more than twice, preferably more than three times, particularly preferably more than four times and in particular more than five times the amount of alkalinity required to neutralize the amount of acid introduced via the foam.

In addition to the wash-active substances, builders are the most important ingredients in detergents and cleaning agents. In the process according to the invention, all builders customarily used in detergents and cleaning agents can be present in the solid bed, in particular thus zeolites, silicates, carbonates, organic cobuilders and - if there are no ecological concerns about their use - the phosphates as well.

Suitable crystalline, layered sodium silicates have the general formula NaMSi _x O _{2x + 1} Η ₂ O, where M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20 and preferred values for x 2 , 3 or 4 are. Such crystalline layered silicates are described, for example, in European patent application EP-A-0 164 514. Preferred crystalline layered silicates of the formula given are those in which M is sodium and x is 2 or 3 ar. In particular, both ß- and δ-sodium disilicate

'yH ₂ O is preferred, it being possible for β-sodium disilicate to be obtained, for example, by the process described in international patent application WO-A-91/08171.

Amorphous sodium silicates with a NajO: SiO ₂ module of 1: 2 to 1: 3.3, preferably 1: 2 to 1: 2.8 and in particular 1: 2 to 1: 2.6, which are delayed in dissolution, can also be used and have secondary washing properties. The release delay compared to conventional amorphous sodium silicates can be done in various ways, for example by surface treatment, compounding, compacting / compression or caused by overdrying. In the context of this invention, the term “amorphous” is also understood to mean “X-ray amorphous”. This means that the silicates in X-ray diffraction experiments do not provide sharp X-ray reflections, as are typical for crystalline substances, but at most one or more maxima of the scattered X-rays, which have a width of several degree units of the diffraction angle. However, it can very well lead to particularly good builder properties if the silicate particles deliver washed-out or even sharp diffraction maxima in electron diffraction experiments. This is to be interpreted as meaning that the products have microcrystalline areas of size 10 to a few hundred nm, values up to max. 50 nm and in particular up to max. 20 nm are preferred. Such so-called X-ray amorphous silicates, which also have a delay in dissolution compared to conventional water glasses, are described, for example, in German patent application DE-A-44 00 024. Compacted / compacted amorphous silicates, compounded amorphous silicates and over-dried X-ray amorphous silicates are particularly preferred.

The finely crystalline, synthetic and bound water-containing zeolite used is preferably zeolite A and / or P. As zeolite P, zeolite ^MAP® (commercial product from Crosfield) is particularly preferred. However, zeolite X and mixtures of A, X and / or P are also suitable. Commercially available and can preferably be used in the context of the present invention, for example a co-crystallizate of zeolite X and zeolite A (about 80% by weight of zeolite X) ), which is sold by CONDEA Augusta SpA under the brand name VEGOBOND AX ^® and by the formula

nN ^ O ^• (ln) K ₂ O ^• Al ₂ O ₃ ^■ (2 - 2.5) SiO ₂ ^■ (3.5 - 5.5) H ₂ O

can be described. Suitable zeolites have an average particle size of less than 10 μm (volume distribution; measurement method: Coulter Counter) and preferably contain 18 to 22% by weight, in particular 20 to 22% by weight, of bound water.

It is of course also possible to use the generally known phosphates as builder substances, provided that such use is not avoided for ecological reasons should be. Of the large number of commercially available phosphates, the alkali metal phosphates, with particular preference for pentasodium or pentapotassium triphosphate (sodium or potassium tripolyphosphate), have the greatest importance in the detergent and cleaning agent industry.

Alkali metal phosphates is the general term for the alkali metal (especially sodium and potassium) salts of the various phosphoric acids, in which one can distinguish between metaphosphoric acids (HPO ₃ ) _n and orthophosphoric acid H ₃ PO _{4 in} addition to higher molecular weight representatives. The phosphates combine several advantages: They act as alkali carriers, prevent limescale deposits on machine parts and lime incrustations in tissues and also contribute to cleaning performance.

Sodium dihydrogen phosphate, NaH ₂ PO ₄ , exists as a dihydrate (density 1.91 like ^"3 , melting point 60 °) and as a monohydrate (density 2.04 like ^{" 3} ). Both salts are white, water-soluble powders, which lose water of crystallization when heated and at 200 ° C into the weakly acidic diphosphate (disodium hydrogen diphosphate, Na ^ P ^), at higher temperature in sodium trimetaphosphate (Na ₃ P ₃ O ₉ ) and Maddrell's salt (see below). NaH ₂ PO _{4 is} acidic; it occurs when phosphoric acid is adjusted to a pH of 4.5 with sodium hydroxide solution and the mash is sprayed. Potassium dihydrogen phosphate (primary or monobasic potassium phosphate, potassium biphosphate, KDP), KH ₂ PO ₄ , is a white salt with a density of 2.33 ^"3 , has a melting point of 253 ° [decomposition to form potassium polyphosphate (KPO ₃ ) and is light soluble in water.

Disodium hydrogen phosphate (secondary sodium phosphate), Na, HPO ₄ , is a colorless, very easily water-soluble crystalline salt. It exists anhydrous and with 2 mol. (Density 2.066 gladly ^'3 , water loss at 95 °), 7 mol. (Density 1.68 gladly ^"3 , melting point 48 ° with loss of 5 H ₂ O) and 12 mol. Water ( Density 1.52, preferably ³ , melting point 35 ° with loss of 5 H ₂ O), becomes anhydrous at 100 ° and changes to diphosphate Na ₄ P ₂ O ₇ when heated more. Disodium hydrogenphosphate is used by neutralizing phosphoric acid with soda solution made from phenolphthalein as an indicator. Dipotassium hydrogen phosphate (secondary or dibasic potassium phosphate), K ₂ HPO ₄ , is an amorphous, white salt that is easily soluble in water.

Trisodium phosphate, tertiary sodium phosphate, Na ₃ PO ₄ , are colorless crystals, which like dodecahydrate have a density of 1.62 ^"3 and a melting point of 73-76 ° C (decomposition), as decahydrate (corresponding to 19-20% P ₂ O ₅ ) have a melting point of 100 ° C. and, in anhydrous form (corresponding to 39-40% P ₂ O ₅ ), a density of 2.536 ^{″ 3} . Trisodium phosphate is readily soluble in water with an alkaline reaction and is produced by evaporating a solution of exactly 1 mol of disodium phosphate and 1 mol of NaOH. Tripotassium phosphate (tertiary or triphase potassium phosphate), K ₃ PO ₄ , is a white, deliquescent, granular powder with a density of 2.56 ^"3 , has a melting point of 1340 ° and is readily soluble in water with an alkaline reaction Heating of Thomas slag with coal and potassium sulfate Despite the higher price, the more soluble, therefore highly effective, potassium phosphates are often preferred over corresponding sodium compounds in the cleaning agent industry.

Tetrasodium diphosphate (sodium pyrophosphate), Na ₄ P ₂ O ₇ , exists in anhydrous form (density 2.534 like ^"3 , melting point 988 °, also given 880 °) and as decahydrate (density 1.815-1.836 like ^{" 3} , melting point 94 ° with loss of water) . Substances are colorless crystals that are soluble in water with an alkaline reaction. Na ₄ P ₂ O ₇ is formed by heating disodium phosphate to> 200 ° or by reacting phosphoric acid with soda in a stoichiometric ratio and dewatering the solution by spraying. The decahydrate complexes heavy metal salts and hardness formers and therefore reduces the hardness of the water. Potassium diphosphate (potassium pyrophosphate), K ₄ P ₂ O ₇ , exists in the form of the trihydrate and is a colorless, hygroscopic powder with a density of 2.33 ^"3 , which is soluble in water, the pH value being 1% Solution at 25 ° is 10.4.

Condensation of the NaH ₂ PO ₄ or the KH ₂ PO ₄ produces higher moles. Sodium and potassium phosphates, in which one can differentiate cyclic representatives, the sodium or potassium metaphosphates and chain-like types, the sodium or potassium polyphosphates. A large number of terms are used in particular for the latter: Melting or annealing phosphates, Graham's salt, Kurrol's and Maddrell's salt. All higher sodium and potassium phosphates are collectively referred to as condensed phosphates.

The technically important pentasodium triphosphate, Na ₅ P ₃ O ₁₀ (sodium tripolyphosphate), is an anhydrous or non-hygroscopic, water-soluble salt of the general formula NaO- [P (O) (ONa) -O] which crystallizes with 6 H ₂ O, -Na with n = 3. Approx. 17 g of the salt free from water of crystallization dissolve in 100 g of water at room temperature, approx. 20 g at 60 ° and 32 g at 100 °; After heating the solution at 100 ° for two hours, hydrolysis produces about 8% orthophosphate and 15% diphosphate. In the production of pentasodium triphosphate, phosphoric acid is reacted with sodium carbonate solution or sodium hydroxide solution in a stoichiometric ratio and the solution is dewatered by spraying. Similar to Graham's salt and sodium diphosphate, pentasodium triphosphate dissolves many insoluble metal compounds (including lime soaps, etc.). Pentapotassium triphosphate, K ₅ P ₃ O ₁₀ (potassium tripolyphosphate), is commercially available, for example, in the form of a 50% strength by weight solution (> 23% P ₂ O ₅ , 25% K ₂ O). The potassium polyphosphates are widely used in the detergent and cleaning agent industry. There are also sodium potassium tripolyphosphates which can also be used in the context of the present invention. These occur, for example, when hydrolyzing sodium trimetaphosphate with KOH:

(NaPO ₃ ) ₃ + 2 KOH - Na ₃ K ₂ P ₃ O ₁₀ + H ₂ O

According to the invention, these can be used just like sodium tripolyphosphate, potassium tripolyphosphate or mixtures of these two; Mixtures of sodium tripolyphosphate and sodium potassium tripolyphosphate or mixtures of potassium tripolyphosphate and sodium potassium tripolyphosphate or mixtures of sodium tripolyphosphate and potassium tripolyphosphate and sodium potassium tripolyphosphate can also be used according to the invention.

As organic cobuilders in the process according to the invention, in particular polycarboxylates / polycarboxylic acids, polymeric polycarboxyla- te, aspartic acid, polyacetals, dextrins, other organic cobuilders (see below) and phosphonates. These classes of substances are described below.

Usable organic builders are, for example, the polycarboxylic acids which can be used in the form of their sodium salts, polycarboxylic acids being understood to mean those carboxylic acids which carry more than one acid function. For example, these are citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, maleic acid, fumaric acid, sugar acids, aminocarboxylic acids, nitrilotriacetic acid (NTA), as long as such use is not objectionable for ecological reasons, and mixtures of these. Preferred salts are the salts of polycarboxylic acids such as citric acid, adipic acid, succinic acid, glutaric acid, tartaric acid, sugar acids and mixtures of these.

The acids themselves can also be used. In addition to their builder effect, the acids typically also have the property of a sour acid component and thus also serve to set a lower and milder pH value of detergents or cleaning agents. Citric acid, succinic acid, glutaric acid, adipic acid, gluconic acid and any mixtures thereof can be mentioned in particular.

Polymeric polycarboxylates are also suitable as builders, for example the alkali metal salts of polyacrylic acid or polymethacrylic acid, for example those with a relative molecular weight of 500 to 70,000 g / mol.

In the context of this document, the molecular weights given for polymeric polycarboxylates are weight-average molecular weights M _{w of} the particular acid form, which were determined in principle by means of gel permeation chromatography (GPC), a UV detector being used. The measurement was carried out against an external polyacrylic acid standard, which provides realistic molecular weight values due to its structural relationship with the investigated polymers. This information differs significantly from the molecular weight information for which polystyrene sulfonic acids are used as standard. The molecular weights measured against polystyrene sulfonic acids are generally significantly higher than the molecular weights given in this document.

Suitable polymers are, in particular, polyacrylates, which preferably have a molecular weight of 2,000 to 20,000 g / mol. Because of their superior solubility, the short-chain polyacrylates which have molar masses from 2000 to 10000 g / mol, and particularly preferably from 3000 to 5000 g / mol, can in turn be preferred from this group.

Also suitable are copolymeric polycarboxylates, in particular those of acrylic acid with methacrylic acid and of acrylic acid or methacrylic acid with maleic acid. Copolymers of acrylic acid with maleic acid which contain 50 to 90% by weight of acrylic acid and 50 to 10% by weight of maleic acid have proven to be particularly suitable. Their relative molecular weight, based on free acids, is generally 2,000 to 70,000 g / mol, preferably 20,000 to 50,000 g / mol and in particular 30,000 to 40,000 g / mol.

The (co) polymeric polycarboxylates can be used either as a powder or as an aqueous solution. The content of (co) polymeric polycarboxylates in the agents is preferably 0.5 to 20% by weight, in particular 3 to 10% by weight.

To improve water solubility, the polymers can also contain AUylsulfonic acids, such as, for example, allyloxybenzenesulfonic acid and methallylsulfonic acid, as monomers.

Also particularly preferred are biodegradable polymers composed of more than two different monomer units, for example those which contain salts of acrylic acid and maleic acid as well as vinyl alcohol or vinyl alcohol derivatives as monomers or those which contain salts of acrylic acid and 2-alkylallylsulfonic acid and sugar derivatives as monomers . Further preferred copolymers are those which are described in German patent applications DE-A-43 03 320 and DE-A-44 17 734 and which preferably contain acrolein and acrylic acid / acrylic acid salts or acrolein and vinyl acetate as monomers.

Also to be mentioned as further preferred builder substances are polymeric aminodicarboxylic acids, their salts or their precursor substances. Particularly preferred are polyaspartic acids or their salts and derivatives, of which it is disclosed in German patent application DE-A-195 40 086 that, in addition to cobuilder properties, they also have a bleach-stabilizing effect.

Other suitable builder substances are polyacetals, which can be obtained by reacting dialdehydes with polyolcarboxylic acids which have 5 to 7 carbon atoms and at least 3 hydroxyl groups. Preferred polyacetals are obtained from dialdehydes such as glyoxal, glutaraldehyde, terephthalaldehyde and their mixtures and from polyol carboxylic acids such as gluconic acid and / or glucoheptonic acid.

Other suitable organic builder substances are dextrins, for example oligomers or polymers of carbohydrates, which can be obtained by partial hydrolysis of starches. The hydrolysis can be carried out by customary, for example acid or enzyme-catalyzed, processes. They are preferably hydrolysis products with average molar masses in the range from 400 to 500,000 g / mol. A polysaccharide with a dextrose equivalent (DE) in the range from 0.5 to 40, in particular from 2 to 30, is preferred, DE being a customary measure of the reducing action of a polysaccharide compared to dextrose, which has a DE of 100 owns. Both maltodextrins with a DE between 3 and 20 and dry glucose syrups with a DE between 20 and 37 as well as so-called yellow dextrins and white dextrins with higher molar masses in the range from 2000 to 30000 g / mol can be used.

The oxidized derivatives of such dextrins are their reaction products with oxidizing agents which are capable of oxidizing at least one alcohol function of the saccharide ring to the carboxylic acid function. Such oxidized dextrins and processes for their production are, for example, from the European patent applications EP-A-0 232 202, EP-A-0 427 349, EP-A-0 472 042 and EP-A-0 542 496 as well as the international patent applications WO 92/18542, WO 93/08251, WO 93/16110, WO 94/28030, WO 95/07303, WO 95/12619 and WO 95/20608 are known. An oxidized oligosaccharide according to German patent application DE-A-196 00 018 is also suitable. A product oxidized at C _{6 of} the saccharide ring can be particularly advantageous.

Oxydisuccinates and other derivatives of disuccinates, preferably ethylenediaminisisuccinate, are further suitable cobuilders. Ethylene diamine N, N'-disuccinate (EDDS) is preferably used in the form of its sodium or magnesium salts. Glycerol disuccinates and glycerol trisuccinates are also preferred in this context. Suitable amounts are 3 to 15% by weight in formulations containing zeolite and / or silicate.

Further usable organic cobuilders are, for example, acetylated hydroxycarboxylic acids or their salts, which may optionally also be in lactone form and which contain at least 4 carbon atoms and at least one hydroxy group and a maximum of two acid groups. Such cobuilders are described, for example, in international patent application WO 95/20029.

Another class of substances with cobuilder properties are the phosphonates. These are, in particular, hydroxyalkane or ammoalkane phosphonates. Among the hydroxyalkane phosphonates, l-hydroxyethane-l, l-diphosphonate (HEDP) is of particular importance as a cobuilder. It is preferably used as the sodium salt, the disodium salt reacting neutrally and the tetrasodium salt in an alkaline manner (pH 9). Preferred ammoalkane phosphonates are ethylenediaminetetramethylenephosphonate (EDTMP), diethylenetriaminepentamethylenephosphonate (DTPMP) and their higher homologues. They are preferably in the form of the neutral sodium salts, e.g. B. as the hexasodium salt of EDTMP or as the hepta and octa sodium salt of DTPMP. HEDP is preferably used as the builder from the class of the phosphonates. The ammoalkane phosphonates also have a pronounced heavy metal de assets. Accordingly, it may be preferred, particularly if the agents also contain bleach, to use aminoalkanephosphonates, in particular DTPMP, or to use mixtures of the phosphonates mentioned.

In addition, all compounds that are able to form complexes with alkaline earth metal ions can be used as cobuilders.

The solid bed placed in the mixer can also contain compounded raw materials, i.e. Ingredients that are themselves the end product of previous process steps. In addition to granulated, compacted or extruded raw materials, spray-dried basic powder can be used as part of the solid bed placed in the mixer. These spray-dried base powders can be free of surfactants (for example polymer compounds), but preferably contain surfactants. If such spray-dried base powders are to be used, the solid bed placed in the mixer contains the spray-dried base powders, preferably the surfactant-containing spray-dried base powders, in amounts of 10 to 80% by weight, preferably 15 to 70, based on the solids placed in the mixer % By weight and in particular from 20 to 60% by weight.

By adding the foam and under the influence of the mixer tools, a surfactant granulate is formed. Processes according to the invention are preferred in which the surfactant foam in the foam: solid weight ratio is from 1: 100 to 9: 1, preferably from 1:30 to 2: 1 and in particular from 1:20 to 1: 1, based on the solid present in the mixer - cloth bed is given. With the preferred amounts of granulation aid (surfactant foam), optimal granulation results are achieved.

As already mentioned, the method according to the invention can be carried out in a large number of conventional mixing and granulating devices. For carrying out the process according to the invention suitable mixers include for example Eirich ^® -Mi shear Series R or RV (trademark of Maschinenfabrik Gustav Eirich, Hardheim), the Schugi ^® Flexomix, the Fukae ^® FS-G mixers (trade marks of Fukae Powtech, Kogyo Co., yes- pan), the Lödige ^® FM, KM and CB mixers (trademark of Lödige Maschinenbau GmbH, Paderborn) or the Drais ^® series T or KT (trademark of Drais-Werke GmbH, Mannheim). Some preferred embodiments of the method according to the invention are described below.

For example, it is possible and preferred to carry out the process according to the invention in a low-speed mixer / granulator at peripheral speeds of the tools from 2 m / s to 7 m / s, the foam containing anionic surfactant acid being present in a time between 0.5 and 10 minutes, preferably between 1 and 7 minutes, and in particular between 2 and 5 minutes, is added to the solid bed placed in the mixer.

Alternatively, in preferred process variants, the foam containing anionic surfactant acid can be used in a high-speed mixer / granulator at circumferential speeds of 8 m / s to 35 m / s in a time between 0.1 and 30 seconds, preferably up to 10 seconds and in particular between 0.5 and 2 seconds be placed on the solid bed placed in the mixer.

While the two process variants described above each describe the use of one mixer, it is also possible according to the invention to combine two mixers with one another. For example, processes are preferred in which the foam containing anionic surfactant acid is placed in a first, low-speed mixer / granulator on a moving solid bed, 40 to 100% by weight, based on the total amount of the constituents used, of the solid and liquid constituents being pregranulated and in a second, high-speed mixer / granulator, the pre-granulate from the first process stage is optionally mixed with the remaining solid and / or liquid constituents and converted into a granulate. In this process variant, the foam containing anionic surfactant acid is placed on a solid bed in the first mixer / granulator and the mixture is pregranulated. The composition of the foam and the solid bed placed in the first mixer are selected so that 40 to 100% by weight, preferably 50 to 90% by weight and in particular 60 to 80% by weight, of the solid and liquid constituents are obtained on the total amount of ingredients used, in "Pregranules" are located. This "pre-granulate" is now mixed with other solids in the second mixer and granulated with the addition of further liquid components to the finished surfactant granulate. It is possible and preferred according to the invention that even in the second process step, the liquid constituents are not sprayed on as a liquid, but rather serve in the form of a foam as a granulation aid ("granulation liquid"). The composition of the foam which is added to the second mixer may differ from the composition of the foam used in the first mixer, so that the processes described above are preferred in which the pre-granules from the first process stage are likewise preferred in the second, high-speed mixer / granulator with the addition of a surfactant-containing foam, the composition of which may differ from the foam used in the first process stage, is granulated into the finished granulate. The second foam can of course be free from anionic surfactant acids.

The sequence of low-speed, high-speed mixers mentioned can also be reversed according to the invention, so that a process according to the invention results in which the foam containing anionic surfactant is added to a moving solid bed in a first, high-speed mixer / granulator, 40 to 100% by weight, based on to the total amount of the constituents used, the solid and liquid constituents are pregranulated and, in a second, low-speed mixer / granulator, the pregranules from the first process stage are optionally mixed with the remaining solid and / or liquid constituents and converted into a granulate.

In this variant of the method, what has been said above is to be applied analogously, so that here, too, methods are preferred in which, in the second, low-speed mixer / granulator, the pregranules from the first stage of the process are also added with a foam containing anionic surfactant, the composition of which is from the foam used in the first stage of the process can deviate, is granulated to the finished granulate.

All of the design variants of the method according to the invention described above can be carried out batchwise or continuously. In the above Design variants of the method according to the invention described are sometimes used high-speed mixers / granulators. It is particularly preferred in the context of the present invention that a mixer is used as a high-speed mixer, which has both a mixing and a shredding device, the mixing shaft at speeds of 50 to 150 revolutions / minute, preferably 60 to 80 revolutions / Minute and the shaft of the shredding device is operated at speeds of 500 to 5000 revolutions / minute, preferably from 1000 to 300 revolutions / minute.

The method according to the invention can be varied over a wide range with regard to the selection of the ingredients to be used and their concentration. Nevertheless, it is preferred if surfactant granules are produced according to the invention, the surfactant contents above 10% by weight, preferably above 15% by weight and in particular above 20% by weight, based in each case on the granules, and bulk densities above 600 g / 1, preferably above 700 g / 1 and in particular above 800 g / 1.

The granulation process according to the invention can be carried out in such a way that particles of predetermined size distribution result. Processes according to the invention are preferred in which the surfactant granules have a particle size distribution in which at least 50% by weight, preferably at least 60% by weight and in particular at least 70% by weight of the particles have sizes in the range from 400 to 1600 μm . The residual moisture content of the surfactant granules produced according to the invention can also be predetermined by the selection of the raw materials, so that subsequent drying steps can be dispensed with. In preferred processes, the surfactant granules have residual free water contents of from 2 to 15% by weight, preferably from 4 to 10% by weight, based on the surfactant granules. The residual free water content can be determined, for example, using a modified UX- Method (Sartorius MA 30, program 120 ° C over 10 minutes).

According to the method according to the invention, it is possible to produce components for detergents and cleaning agents which are only mixed with other ingredients the finished detergent and cleaning agent. Of course, according to the invention, surfactant granules can also be produced which, in themselves, are already a finished detergent and cleaning agent (for example a textile color detergent).

The surfactant granules produced by the process according to the invention can subsequently be mixed with further ingredients of detergents and cleaning agents to give the finished product. However, these ingredients can also be incorporated directly into the surfactant granules via the solid bed or via the surfactant foam and are described below:

In addition to the constituents mentioned, surfactant and builders are, in particular in washing and cleaning agents, the usual ingredients from the group of bleaching agents, bleach activators, enzymes, pH adjusters, fragrances, perfume carriers, fluorescent agents, dyes, foam inhibitors, silicone oils, anti-redeposition agents, optical brighteners, graying inhibitors , Color transfer inhibitors and corrosion inhibitors are important.

Among the compounds which serve as bleaching agents and supply H ₂ O ₂ in water, sodium perborate tetrahydrate and sodium perborate monohydrate are of particular importance. Further bleaching agents that can be used are, for example, sodium percarbonate, peroxypyrophosphates, citrate perhydrates and H ₂ O ₂ -producing peracid salts or peracids, such as perbenzoates, peroxophthalates, diperazelaic acid, phthaloiminoperacid or diperdodecanedioic acid. Typical organic bleaching agents are the diacyl peroxides, such as dibenzoyl peroxide. Other typical organic bleaching agents are peroxy acids, examples of which include alkyl peroxy acids and aryl peroxy acids. Preferred representatives are (a) the peroxybenzoic acid and its ring-substituted derivatives, such as alkyl peroxybenzoic acids, but also peroxy-α-naphthoic acid and magnesium monoperphthalate, (b) the aliphatic or substituted aliphatic peroxyacids, such as peroxylauric acid, peroxystearic acid, ε-phthalimidoxy acid panoic acid aprooxyaproacid (p-oxoacid) )], o-carboxybenzamidoperoxycaproic acid, N-nonenylamidoperadipic acid and N-nonenylamidopersuccinate, and (c) aliphatic and araliphatic peroxydicarboxylic acids, such as 1,12-diperoxycarboxylic acid, 1, 9-diperoxyazelaic acid, diperocysebacic acid, diperoxybrassylic acid, the diperoxyphthalic acids, 2-decyldiperoxybutane-l, 4-diacid, N, N-terephthaloyl-di (6-aminopercaproic acid) can be used.

Chlorine or bromine-releasing substances can also be used as bleaching agents in compositions for machine dishwashing. Suitable chlorine or bromine-releasing materials include, for example, heterocyclic N-bromo- and N-chloramides, for example trichloroisocyanuric acid, tribromoisocyanuric acid, dibromoisocyanuric acid and / or dichloroisocyanuric acid (DICA) and / or their salts with cations such as potassium and sodium. Hydantoin compounds such as 1,3-dichloro-5,5-dimethylhydanthoin are also suitable.

In order to achieve an improved bleaching effect when washing or cleaning at temperatures of 60 ° C and below, bleach activators can be incorporated. Bleach activators which can be used are compounds which, under perhydrolysis conditions, give aliphatic peroxocarboxylic acids having preferably 1 to 10 C atoms, in particular 2 to 4 C atoms, and / or optionally substituted perbenzoic acid. Suitable substances are those which carry O- and / or N-acyl groups of the number of carbon atoms mentioned and / or optionally substituted benzoyl groups. Preferred are multiply acylated alkylenediamines, in particular tetraacetylethylenediamine (TAED), acylated triazine derivatives, in particular 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), acylated glycolurils, in particular tetraacetylglycoluril (TAGU), N-acylimides, especially N-nonanoylsuccinimide (NOSI), acylated phenol sulfonates, especially n-nonanoyl- or isononanoyloxybenzenesulfonate (n- or iso-NOBS), carboxylic acid anhydrides, especially phthalic anhydride, acylated polyhydric alcohols and especially triacetyl, especially triacetin, 5-diacetoxy-2,5-dihydrofuran.

In addition to the conventional bleach activators or in their place, so-called bleach catalysts can also be incorporated. These substances are bleach-enhancing transition metal salts or transition metal complexes such as, for example, Mn, Fe, Co, Ru or Mo salt complexes or carbonyl complexes. Also Mn, Fe, Co, Ru, Mo, Ti, V and Cu complexes with N-containing tripod ligands and Co, Fe, Cu and Ru amine complexes can be used as bleaching catalysts.

Suitable enzymes are those from the class of proteases, lipases, amylases, cellulases or mixtures thereof. Enzymes obtained from bacterial strains or fungi such as BaciUus subtilis, BaciUus licheniformis and Streptomyces griseus are particularly suitable. Proteases of the subtilisin type and in particular proteases which are obtained from BaciUus lentus are preferably used. Enzyme mixtures, for example of protease and amylase or protease and lipase or protease and cellulase or of cellulase and lipase or of protease, amylase and lipase or protease, lipase and cellulase, but in particular mixtures containing cellulase, are of particular interest. Peroxidases or oxidases have also proven to be suitable in some cases. The enzymes can be adsorbed on carriers and / or embedded in coating substances in order to protect them against premature decomposition.

In addition, components can be used which have a positive influence on the washability of oil and fat from textiles (so-called soil repellents). This effect becomes particularly clear when a textile is soiled that has already been washed several times beforehand with a detergent according to the invention which contains this oil and fat-dissolving component. The preferred oil- and fat-dissolving components include, for example, nonionic cellulose ethers such as methyl cellulose and methyl hydroxypropyl cellulose with a proportion of methoxyl groups of 15 to 30% by weight and of hydroxypropoxyl groups of 1 to 15% by weight, in each case based on the nonionic cellulose ether, and the polymers of phthalic acid and / or terephthalic acid or their derivatives known from the prior art, in particular polymers of ethylene terephthalates and / or polyethylene glycol terephthalates or anionically and / or nonionically modified derivatives thereof. Of these, the sulfonated derivatives of phthalic acid and terephthalic acid polymers are particularly preferred.

The detergents and cleaning agents can contain, as optical brighteners, derivatives of diaminostilbenedisulfonic acid or its alkali metal salts. Suitable are, for example, salts of 4,4'- Bis (2-anilino-4-mo holino-l, 3,5-triazinyl-6-amino) stilbene-2,2'-disulfonic acid or compounds of the same structure which instead of the morpholino group have a diethanolamino group, a methylamino group, wear an anilino group or a 2-methoxyethylamino group. Brighteners of the substituted diphenylstyryl type may also be present, for example the alkali salts of 4,4'-bis (2-sulfostyryl) diphenyl, 4,4'-bis (4-chloro-3-sulfostyryl) diphenyl, or 4- (4-chlorostyryl) -4 '- (2-sulfostyryl) diphenyl. Mixtures of the aforementioned brighteners can also be used.

Dyes and fragrances are added to detergents and cleaning agents in order to improve the aesthetic impression of the products and, in addition to the softness performance, to provide the consumer with a visually and sensorially "typical and unmistakable" product. Individual fragrance compounds, for example the synthetic products of the ester, ether, aldehyde, ketone, alcohol and hydrocarbon type, can be used as perfume oils or fragrances. Fragrance compounds of the ester type are, for example, benzyl acetate, phenoxyethyl isobutyrate, p-tert-butylcyclohexyl acetate, linalyl acetate, dimethylbenzylcarbyl acetate, phenylethyl acetate, linalyl benzoate, benzyl formate, ethyl methylphenyl glycinate, allyl cyclohexyl benzylatepylate propylate propylate propylate. The ethers include, for example, benzylethyl ether, the aldehydes, for example, the linear alkanals with 8-18 C atoms, citral, citronellal, citronellyloxyacetaldehyde, cyclamenaldehyde, hydroxycitronellal, lilial and bourgeonal, the ketones, for example, the ionone, oc- Isomethyl ionone and methyl cedryl ketone, the alcohols anethole, citronellol, eugenol, geraniol, linalool, phenylethyl alcohol and terpineol, the hydrocarbons mainly include the terpenes such as limonene and pinene. However, preference is given to using mixtures of different fragrances which together produce an appealing fragrance. Perfume oils of this type can also contain natural fragrance mixtures such as are obtainable from plant sources, for example pine, citrus, jasmine, patchouli, rose or ylang-ylang oil. Also suitable are muscatel, sage oil, chamomile oil, clove oil, lemon balm oil, mint oil, cinnamon leaf oil, linden blossom oil, juniper berry oil, vetiver oil, olibanum oil, galbanum oil and labdanum oil as well as orange blossom oil, neroliol, orange peel oil and sandalwood oil. The colorant content of detergents and cleaning agents is usually less than 0.01% by weight, while fragrances can make up up to 2% by weight of the entire formulation.

The fragrances can be incorporated directly into the washing and cleaning agents, but it can also be advantageous to apply the fragrances to carriers, which increase the adhesion of the perfume to the laundry and ensure a long-lasting fragrance of the textiles due to a slower fragrance release. Cyclodextrins, for example, have proven useful as such carrier materials, and the cyclodextrin-perfume complexes can additionally be coated with further auxiliaries.

To improve the aesthetic impression of detergents and cleaning agents, they can be colored with suitable dyes. Preferred dyes, the selection of which is not difficult for the person skilled in the art, have a high storage stability and are insensitive to the other ingredients of the compositions and to light, and have no pronounced substantivity towards textile fibers in order not to dye them.

The foam produced in the process according to the invention and its use as a granulation aid have not hitherto been described in the prior art. Another object of the present invention is therefore a surfactant foam, obtainable by applying a surfactant-containing flowable component with a gaseous medium, characterized in that the foam contains anionic surfactant acid (s) and average pore sizes below 10 mm, preferably below 5 mm and in particular below 2 mm , having.

As already emphasized in the description of the method according to the invention, a surfactant foam is preferred in which the gaseous medium makes up at least 20% by volume, based on the amount of liquid to be foamed. In the case of a particularly preferred surfactant foam, the gaseous medium makes up one to three hundred times, preferably five to two hundred times and in particular ten to one hundred times the volume of the amount of liquid to be foamed. The surfactant foam according to the invention is preferably high in surfactant. Surfactant foams which have surfactant contents of 50 to 99% by weight, preferably 60 to 95% by weight and in particular 70 to 90% by weight, based in each case on the weight of the foam, are preferred.

Another object of the present invention is the use of the surfactant foams according to the invention as a granulation liquid in the production of surfactant granules. With regard to the quantitative ratios between granulation aids (surfactant foam) and solid bed, the mixers to be used and the ingredients which can be used in the solid bed, reference is made here to the above statements.

Examples:

A tower powder containing surfactant was produced by spray drying and was introduced together with soda in a 20 liter ploughshare mixer from Lödige. The composition of the tower powder is given in Table 1. With the mixing tools running, C ₉ . _13- Alkylbenzenesulfonic acid (ABS acid) was added to the mixer as a granulation aid, as a result of which the mixture granulated. In the process variants E1 and E2 according to the invention, the anionic surfactant acid was brought up to five times the volume by foaming with compressed air before adding it to the mixer. In the comparative examples VI and V2, the anionic surfactant acid was added to the mixer in liquid form. In all four cases the ABS acid (foam or liquid) had a temperature of 60 ° C. After four minutes of granulation, the granules were sprayed with perfume oil. After 7 days of storage at 20 ° C, the fragrance track was assessed by a perfumer. Table 2 shows the composition of the granules, the oversize particles formed during granulation and the fragrance track after storage.

Table 1: Composition of the tower powder [% by weight]:

Sokalan ^® CP5 is an acrylic acid-maleic acid copolymer (BASF) Table 2: Composition of the granules [% by weight]

Table 2 shows that on the one hand the coarse fraction is reduced by the process according to the invention, on the other hand the formation of acidic nests and the resulting impairment of the fragrance impression are avoided by the more uniform distribution of the acid.

Claims

Claims:

1. A process for the preparation of surfactant granules, wherein a surfactant-containing flowable component is acted upon and foamed with a gaseous medium and the resulting surfactant-containing foam is subsequently added to a solid bed placed in a mixer, characterized in that the surfactant-containing flowable component contains anionic surfactant acid (s).

2. The method according spoke 1, characterized in that the surfactant-containing flowable component one or more anionic surfactant acid (s) in amounts of 20 to 100 wt .-%, preferably from 50 to 95 wt .-%> and in particular from 60 to 90 wt .-%, each based on the surfactant-containing component.

3. The method according spoke 2, characterized in that the surfactant-containing flowable component alkylbenzenesulfonic acids in amounts of 20 to 99 wt .-%, preferably from 30 to 95 wt .-% and in particular from 40 to 90 wt .-%, each based on the surfactant-containing component.

4. The method according to any one of claims 1 to 3, characterized in that the surfactant-containing flowable component additionally fatty acids and / or soaps in amounts of 1 to 30 wt .-%, preferably from 2 to 25 wt .-% and in particular from 5 to 20% by weight, based in each case on the surfactant-containing component.

5. The method according to any one of claims 1 to 4, characterized in that the surfactant-containing flowable component additionally nonionic (s) surfactant (s) in amounts of 1 to 50 wt .-%, preferably from 2 to 40 wt .-% and in particular from 5 to 30% by weight, based in each case on the surfactant-containing component.

6. The method according to claim 5, characterized in that the surfactant-containing flowable component alkoxylated, preferably ethoxylated nonionic surfactants, preferably the reaction products of C _{8th 22} fatty alcohols, preferably C _12.20 Fatty alcohols and especially C _{14,., 8} fatty alcohols containing 1 to 30 moles of ethylene oxide, preferably 2 to 20 mol ethylene oxide and more preferably 5 to 10 moles of ethylene oxide.

7. The method according to any one of claims 1 to 6, characterized in that the surfactant-containing flowable component less than 20 wt .-%, preferably less than 15 wt .-% and in particular less than 10 wt .-% water, each based on the component containing surfactant.

8. The method according to any one of claims 1 to 7, characterized in that the surfactant-containing flowable component contains further ingredients of detergents and cleaning agents, in particular substances from the group of complexing agents, polymers, optical brighteners, dyes and fragrances and alkalis.

9. The method according to any one of claims 1 to 8, characterized in that the amount of gas used for foaming is one to three hundred times, preferably five to two hundred times and in particular ten to one hundred times the volume of the amount of the surfactant-containing flowable component to be foamed.

10. The method according to any one of claims 1 to 9, characterized in that air is used as the gaseous medium.

11. The method according to any one of claims 1 to 10, characterized in that the surfactant-containing flowable component to be foamed has temperatures of 20 to 120 ° C, preferably from 30 to 90 ° C and in particular from 50 to 75 ° C, prior to foaming.

12. The method according to any one of claims 1 to 11, characterized in that the surfactant-containing foam has temperatures below 115 ° C, preferably between 20 and 80 ° C and in particular between 30 and 70 ° C.

13. The method according to any one of claims 1 to 12, characterized in that the surfactant-containing foam has a density below 0.80 like ^"3 , preferably from 0.10 to 0.60 like ^{" 3} and in particular from 0.30 to 0, 55 likes ^"3 .

14. The method according to any one of claims 1 to 13, characterized in that the surfactant-containing foam has average pore sizes below 10 mm, preferably below 5 mm and in particular below 2 mm.

15. The method according to any one of claims 14 to 14, characterized in that the surfactant-containing foam meets the criteria mentioned when added to the mixer.

16. The method according to any one of claims 1 to 15, characterized in that the solid bed placed in the mixer contains one or more substances from the group of builders, in particular the alkali metal carbonates, sulfates and silicates, the zeolites and the polymers.

17. The method according to any one of claims 1 to 16, characterized in that the solid bed placed in the mixer contains one or more substances from the group of alkali metal carbonates and / or hydrogen carbonates, preferably sodium carbonate, in an amount which is used to neutralize the foam amount of acid supplied is sufficient.

18. The method according to any one of claims 1 to 17, characterized in that the solid bed placed in the mixer spray-dried base powder, preferably surfactant-containing spray-dried base powder, in amounts of 10 to 80 wt .-%, preferably from 15 to 70 wt .-% and in particular from 20 to 60 wt .-%, based on the solids in the mixer.

19. The method according to any one of claims 1 to 18, characterized in that the surfactant-containing foam in the foam: solid weight ratio of 1: 100 to 9: 1, pre- preferably from 1:30 to 2: 1 and in particular from 1:20 to 1: 1, is added to the solid bed placed in the mixer.

20. The method according to any one of claims 1 to 19, characterized in that the surfactant granules surfactant contents above 10 wt .-%, preferably above 15 wt .-% and in particular above 20 wt .-%, each based on the granules, and bulk densities above 600 g / 1, preferably above 700 g / 1 and in particular above 800 g / 1.

21. The method according to any one of claims 1 to 20, characterized in that the surfactant granules have residual free water contents of 2 to 15 wt .-%, preferably from 4 to 10 wt .-%>, based on the surfactant granules.

22. surfactant foam, obtainable by applying a surfactant-containing flowable component with a gaseous medium, characterized in that the

Foam contains anionic surfactant acid (s) and has average pore sizes below 10 mm, preferably below 5 mm and in particular below 2 mm.

23. surfactant foam according spoke 22, characterized in that the gaseous medium makes up at least 20 vol .-%>, based on the amount of liquid to be foamed.

24. surfactant foam according spoke 23, characterized in that the gaseous medium is one to three hundred times, preferably five to two hundred times and in particular ten to one hundred times the volume of the amount of liquid to be foamed.

25. surfactant foam according to any one of claims 22 to 24, characterized in that it contains anionic surfactant acid contents of 50 to 99% by weight, preferably 60 to 95% by weight and in particular 70 to 90% by weight, in each case based on the Weight of the foam.

6. Use of surfactant foams according to one of claims 22 to 25, as a granulation liquid in the production of surfactant granules.