EP0642576B1 - Continuous production process of a granulated washing and/or cleaning agent - Google Patents

Abstract

PCT No. PCT/EP93/01191 Sec. 371 Date Dec. 19, 1994 Sec. 102(e) Date Dec. 19, 1994 PCT Filed May 13, 1993 PCT Pub. No. WO93/23523 PCT Pub. Date Nov. 25, 1993A process for the continuous production of a granular detergent composition comprising: (a) pregranulating at least 40% by weight of a mixture of solid and liquid detergent components, based on the total weight of the solid and liquid cleaning components, in a first low-speed mixer/granulator having mixing tools contained therein, to form a pregranulated detergent mixture; and (b) granulating the pregranulated detergent mixture in a second high-speed mixer/granulator to form a final granular detergent composition.

Description

The invention relates to a process for the continuous production of granular detergents and / or cleaning agents, wherein non-dusting and non-greasy granules are obtained by suitably chosen process conditions, which preferably have a bulk density between 600 and 1000 g / l.

The prior art knows a number of proposals for the batchwise or continuous production of compacted granules. Either high-speed, high-speed mixers / granulators are used, or two mixers / granulators are connected in series, whereby the first mixer / granulator is a high-speed, high-speed mixer / granulator and the second mixer / granulator is a slow-running, low-speed mixer / granulator. For example, granulations in a high-speed, high-speed mixer / granulator are disclosed in European patent applications 351 937 and 339 996.

Methods in which a high-speed, high-speed and a slow-speed, low-speed mixer / granulator are connected in series are described, for example, in European patent application 420 317 and in European patent application 390 251. According to the teaching of EP-A-420 317, the high-speed mixer / granulator initially neutralizes anionic surfactants in their acid form, which are then converted into granules with further constituents. These granules are in a plastic state and are deformed in the slow-running mixer / granulator, whereby compression occurs. The process is completed by a drying or cooling step. EP-A-390 251 describes a two-stage granulation process in which 0.1 to 40% by weight of the solid starting material is added after the first granulation stage (high-speed mixer / granulator) and, if appropriate, during the second granulation stage (slow-speed mixer / granulator) becomes.

A common feature of these known processes is that the granules obtained by them have a bulk density of between about 600 and 900 g / l, but tend to cake, stick and grease if the processes are not nearly water-free and / or essentially free of nonionic surfactants and / or be carried out in a certain temperature range. In addition, the bulk density can only be set to a small extent in a targeted manner.

It was therefore the object of the invention to provide a process for the continuous production of non-dusting and non-greasy detergents and / or cleaning agents which do not tend to cake and stick, and which contain anionic surfactants and nonionic surfactants in substantial amounts. This process should also make it possible to adjust the bulk density of the granules in a targeted manner, as well as to produce granules with a relatively low proportion of coarse particles.

Process for the continuous production of a granular detergent and / or cleaning agent with a high bulk density by a two-stage granulation in two consecutive mixers / granulators, characterized in that in a first, low-speed mixer / granulator, through which the product flows horizontally and in which the granulation Circumferential speeds of the mixing tools between 2 m / s and 7 m / s is possible, 40 to 100 wt .-%, based on the total amount of the components used, the solid and liquid components pre-granulated and in a second, high-speed mixer / granulator by the mixture to be granulated is flowed through vertically and its mixing tools can be operated at peripheral speeds of at least about 8 m / s, the pre-granules from the first process stage are optionally mixed with the remaining solid and / or liquid constituents and converted into granules, the en The resulting granulate is plastic to the extent that it can be deformed in the second granulation stage and the proportion of the granules with a diameter above 2 mm is less than 25% by weight.

A special feature of the process according to the invention is that in the two-stage granulation process, in which a low-speed and a high-speed mixer / granulator are used, in contrast to the known processes of the prior art, the first part of the granulation in a low-speed mixer / granulator and only the second part is carried out in a high-speed mixer / granulator, the process conditions in the high-speed mixer / granulator being set according to the requirements of the desired granulate so that the The first, low-speed mixer / granulator, the resulting granulate is not adhesive, but is nevertheless plastic to the extent that it can be deformed to compress it. As a result, the proportion of coarse-grain granules formed in the first low-speed mixer / granulator can be largely reduced without the coarse-grain fraction being ground or pulverized.

As a low-speed mixer / granulator, all mixers / granulators through which the product flows horizontally can be used in the first granulation stage, in which the product is moved in the mixer room by mixing tools. In addition, the granulation can be carried out by. cutter heads located in the lower part of the mixer drum are accelerated. Granulation in these mixers / granulators is possible at peripheral speeds of the mixing tools between 2 m / s and 7 m / s and is preferably carried out at peripheral speeds between 4 m / s and 5 m / s.

Low-speed mixers / granulators which are preferably used are, for example, the ploughshare mixers from Lödige (Federal Republic of Germany) and the intensive mixers from IMCATEC (Federal Republic of Germany). The first granulation stage is preferably carried out in a time of 0.5 to 10 minutes, average residence times in the first granulation stage between 1 and 6 minutes being preferred.

In the second granulation stage, mixers / granulators are used as high-speed mixers / granulators, through which the mixture to be granulated flows vertically and whose mixing tools can be operated at peripheral speeds of at least about 8 m / s. It is preferred that a concentrically arranged in a cylindrical mixing chamber and fast rotating shaft on which the mixing tools are in the form of mixing knives or beaters, the product in a spiral downward annular layer along the mixer chamber wall at a peripheral speed of the mixing tools of 8 m / s to 35 m / s, preferably at peripheral speeds of 12 m / s to 30 m / s, is transported to the mixer outlet. A suitable high-speed mixer / granulator is, for example, the ring-layer mixer from Schugi (Netherlands). The second stage of granulation is generally in a much shorter time than the first granulation stage, for example up to 30 seconds. Preferred granulation times in the second granulation stage are 0.1 to 10 seconds and in particular 0.5 to 2 seconds.

The sequence of the granulation steps defined according to the invention (first granulation in a low-speed mixer / granulator, then in a high-speed mixer / granulator) enables almost any desired bulk density between 600 and Selectively set 1100 g / l. The parameter of the first granulation stage, by means of which the bulk density can be influenced, is the energy input to the mixture to be granulated, a high energy input being achieved over long dwell times and over the number and speed of the cutter heads to be used. Heavy granules are obtained through high energy inputs. The same applies to the second pelletizing stage, in which the peripheral speeds of the mixing tools and the energy input are increased by increasing the speeds of the mixer shaft, which leads to an increase in the bulk density in addition to the reduction of coarse particles. Another parameter by means of which the bulk density can be changed at least slightly, for example by approx. 30 to 80 g / l, in particular up to 60 g / l, is the temperature of the pre-granulate (this is the granulate obtained in the first granulation stage) when entering the second granulation stage. Temperatures of the pre-granulate of at most 90 ° C., in particular from 30 to 60 ° C., are preferred, higher temperatures leading to lower bulk densities compared to lower temperatures in the order of magnitude specified above.

The most important parameter for setting the bulk density is the addition of the liquid constituents, which also serve as granulating liquid and which can be added either only in the first, low-speed mixer / granulator or partly in the low-speed mixer / granulator and partly in the high-speed mixer / granulator. The general rule is that by adding granulating liquids alone in the first, low-speed mixer / granulator, higher ones Bulk weights, for example between 800 and 950 g / l, can be achieved, while for setting lower bulk weights, for example bulk weights between 600 and 800 g / l, it is advisable to add part of the granulating liquid only in the second, high-speed mixer / granulator. For example, for a special recipe, granules with a bulk density of about 850 g / l were obtained by adding the entire granulating liquid in the first mixer / granulator. By adding 8% by weight of the granulating liquid, based on the total amount of the constituents used, in the second, high-speed mixer / granulator, granules with a bulk density of 680 g / l were obtained for the same formulation. By adding 8.5% to 10.5% by weight of the granulating liquid in the second mixer, granules with a bulk density between 600 g / l and 570 g / l were obtained for the same recipe.

Just as it is possible to add some of the liquid components only in the high-speed mixer / granulator, some of the solid components - either alone or in addition to the part of the granulating liquid - can only be used in the high-speed mixer / granulator. It generally applies that the addition of solids, in particular fine-particle solids such as zeolite powder, for example Wessalith P ^(R) (commercial product from Degussa, Federal Republic of Germany), sodium sulfate or sodium carbonate, increases the bulk density in the second mixer / granulator can. The addition of solids in the second granulation stage can also serve to improve the further processability of the granules and the flow properties of the finished granules.

Overall, it is preferred that 40 to 100% by weight, preferably 60 to 100% by weight and in particular up to 95% by weight of the solid and liquid constituents are pregranulated in the first mixer / granulator and then with 0 to 60% by weight %, preferably 5 to 40% by weight of remaining solid and / or liquid constituents are mixed in the second mixer / granulator and then transferred to the finished, but not yet dried and therefore possibly still moist granulate.

The solid constituents can be introduced into the process as powders or granules which have been obtained by granulation or spray drying and have a bulk density of, for example, 200 to 600 g / l. The powders are usually individual components, for example zeolite, sodium carbonate, tripolyphosphate, water glass or sodium sulfate, while the granules preferably contain several components, mostly also small components and liquid feedstocks. Powder alone or granules alone can be used.

However, it is preferred that at least some of the constituents used in the granulation in the first mixer / granulator, preferably 10 to 100% by weight and in particular 40 to 100% by weight, in each case based on those used in the first mixer / granulator solid components, used as granules. The use of 10 to 40% by weight, in particular up to 30% by weight, based in each case on the total formulation of the granules, preferably spray-dried granules, has proven to be particularly advantageous.

In principle, all known solid ingredients of detergents and / or cleaning agents can be used as solid constituents. Preferred solid constituents are anionic surfactants, builder substances, alkaline and neutral salts, bleaching agents and graying inhibitors.

Preferred surfactants of the sulfonate type are C ₉ -C ₁₃ alkylbenzenesulfonates, olefin sulfonates, ie mixtures of alkene and hydroxyalkanesulfonates and disulfonates such as are obtained, for example, from C ₁₂ -C ₁₈ monoolefins with a terminal or internal double bond by sulfonating with gaseous Sulfur trioxide and subsequent alkaline or acidic hydrolysis of the sulfonation products is considered. Also suitable are alkanesulfonates obtained from C ₁₂ -C ₁₈ alkanes, for example by sulfochlorination or sulfoxidation with subsequent hydrolysis or neutralization.

Preferred anionic surfactants are also the salts of alkylsulfosuccinic acid, which are also referred to as sulfosuccinates or as sulfosuccinic acid esters, and the monoesters and / or diesters of sulfosuccinic acid Alcohols, preferably fatty alcohols and especially ethoxylated fatty alcohols. Preferred sulfosuccinates contain C ₈ to C ₁₈ fatty alcohol residues or mixtures thereof. Particularly preferred sulfosuccinates contain a fatty alcohol residue which is derived from ethoxylated fatty alcohols, which in themselves are nonionic surfactants (description see below). Again, sulfosuccinates, the fatty alcohol residues of which are derived from ethoxylated fatty alcohols with a restricted homolog distribution, are particularly preferred.

Also suitable are the esters of α-sulfo fatty acids (ester sulfonates), e.g. the α-sulfonated methyl esters of hydrogenated coconut, palm kernel or tallow fatty acids.

Suitable surfactants of the sulfate type are the sulfuric acid monoesters from primary alcohols of natural and synthetic origin, in particular from fatty alcohols, for example from coconut oil alcohol, tallow fatty alcohol, oleyl alcohol, lauryl, myristyl, cetyl or stearyl alcohol, or the C ₁₀ -C ₂₀ oxo alcohols, and those secondary alcohols of this chain length. The sulfuric acid monoesters of the alcohols ethoxylated with 1 to 6 mol of ethylene oxide, such as 2-methyl-branched C ₉ -C ₁₁ alcohols with an average of 3.5 mol of ethylene oxide, are also suitable. Fatty alcohol mixtures which may additionally contain proportions of unsaturated alcohols, for example oleyl alcohol, are also preferred. Mixtures in which the proportion of the alkyl radicals is 50 to 70% by weight on C ₁₂ , 18 to 30% by weight on C ₁₄ , 5 to 15% by weight on C ₁₆ , are preferred 3% by weight on C ₁₀ and less than 10% by weight on C _{18 are} distributed.

Other suitable anionic surfactants are, in particular, soaps, preferably in amounts of 0.5 to 8% by weight. Saturated fatty acid soaps are suitable, such as the salts of lauric acid, myristic acid, palmitic acid or stearic acid, and in particular soap mixtures derived from natural fatty acids, for example coconut, palm kernel or tallow fatty acids. In particular, those soap mixtures are preferred which are composed of 50 to 100% by weight of saturated C ₁₂ -C ₁₈ fatty acid soaps and 0 to 50% by weight of oleic acid soap.

The anionic surfactants can be in the form of their sodium, potassium or ammonium salts and as soluble salts of organic bases, such as mono-, di- or triethanolamine. The anionic surfactants are preferably in the form of their sodium or potassium salts, in particular in the form of the sodium salts.

The anionic surfactants are preferably used in amounts of 3 to 25% by weight, in particular in amounts of 10 to 20% by weight, in each case based on the sum of the constituents used. However, their content can also exceed 15% by weight. Preferred anionic surfactants are fatty alkyl sulfates, alkylbenzenesulfonates, sulfosuccinates and mixtures thereof, such as mixtures of fatty alkyl sulfates and sulfosuccinates or fatty alkyl sulfates and fatty alkylbenzenesulfonates, especially in combination with soap. It is particularly preferred that at least some of the sulfonate and / or sulfate surfactants are used as a component of the granulating liquid rather than as a solid component.

The known zeolites and phosphates, in particular tripolyphosphates, are particularly suitable as builder substances. Their content is preferably 20 to 60% by weight, in particular 20 to 50% by weight, in each case based on the sum of the constituents used and calculated as an anhydrous active substance.

The finely crystalline, synthetic and bound water-containing zeolite used is preferably zeolite NaA in detergent quality. It is preferably used as a spray-dried powder. Preferred zeolites have an average particle size of less than 10 μm (volume distribution; measurement method: Coulter Counter) and preferably contain 20 to 22% by weight of bound water.

Usable organic builders are, for example, the polycarboxylic acids preferably used in the form of their sodium salts, such as citric acid, succinic acid, glutaric acid, adipic acid, tartaric acid and nitrilotriacetic acid (NTA), provided that such use is not objectionable for ecological reasons, and mixtures of these.

Polymeric polycarboxylates come into consideration as further organic builder substances.

Suitable polymeric polycarboxylates are, for example, the sodium salts of polyacrylic acid or polymethacrylic acid, for example those with a relative molecular weight of 800 to 150,000 (based on acid). Suitable copolymeric polycarboxylates are, 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. Copolymers in which 60 to 85% by weight of acrylic acid and 40 to 15% by weight of maleic acid are present are particularly preferred. Their relative molecular weight, based on free acids, is generally 5,000 to 200,000, preferably 10,000 to 120,000 and in particular 50,000 to 100,000.

The content of (co) polymeric polycarboxylates in the agents is preferably 0.5 to 8% by weight.

It is particularly preferred that at least a portion, preferably 20 to 100 wt .-% of the (co) polymeric polycarboxylates used not as a solid component, but in the form of an approximately 20 to 55 wt .-% aqueous solution as a component of Granulating liquid is used.

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, for example as described in European patent application 280 223. 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.

The alkaline salts used with preference include water-soluble inorganic salts such as bicarbonates, carbonates, silicates or mixtures thereof; in particular alkali carbonate and alkali silicate, especially sodium silicate with a molar ratio of 1: 1 to 1: 4.5, used. The sodium carbonate content of the agents is preferably up to 20% by weight, advantageously between 1 and 15% by weight. The content of sodium silicate in the agents, for example amorphous or crystalline sodium disilicate, is generally up to 10% by weight and preferably between 2 and 8% by weight.

If sulfates are used, this is preferably done in amounts between 15 and 40% by weight, based on the finished granulate. However, processes in which no sulfate is used are also preferred.

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 percarbonates, peroxypyrophosphates, citrate perhydrates and H ₂ O ₂ -producing peracidic salts or peracids, such as perbenzoates, peroxaphthalates, diperazelaic acid or diperdodecanedioic acid. The bleaching agent content of the agents is preferably 5 to 25% by weight and in particular 10 to 20% by weight, based on the finished granulate. The bleaching agents can be added either in the granulation process according to the invention or in a subsequent processing step. If bleaching agents, preferably perborates and percarbonate, are used in the two-stage granulation process according to the invention, they are preferably added in the second granulation stage, the granule temperature not exceeding 70 ° C. If necessary, this can be achieved by cooling.

Graying inhibitors have the task of keeping the dirt detached from the fibers suspended in the liquor and thus preventing graying. Water-soluble colloids of mostly organic nature are suitable for this, for example the water-soluble salts of polymeric carboxylic acids, glue, gelatin, salts of ether carboxylic acids or ether sulfonic acids of starch or cellulose or salts of acidic sulfuric acid esters of cellulose or starch. Water-soluble polyamides containing acidic groups are also suitable for this purpose. Soluble starch preparations and starch products other than those mentioned above can also be used, for example degraded starch, aldehyde starches etc. However, preference is given to Carboxymethyl cellulose, methyl cellulose, methyl hydroxyethyl cellulose and mixtures thereof and polyvinylpyrrolidone, if appropriate in mixtures with the cellulose derivatives, are preferably used in amounts between 0.1 and 5% by weight, in particular up to 3% by weight.

To granulate the solid constituents, a granulating liquid is required which either consists only of pure liquid constituents or mixtures thereof or which contains solid constituents in dissolved and / or suspended form. The granulating liquid is preferably used in amounts of 5 to 30% by weight, based on the total amount of the constituents used. Overall, it can only be used in the first mixer / granulator or partly in the first mixer / granulator and partly in the second mixer / granulator. It is preferred that, depending on the desired bulk density, 0 to 20% by weight, preferably up to 10% by weight, based in each case on the total amount of the constituents used, of granulating liquid are added in the second, high-speed mixer / granulator. The granulating liquid preferably consists of liquid constituents of detergents and / or cleaning agents or of water, of aqueous solutions and / or of mixtures which contain per se solid constituents and liquid constituents of detergents and / or cleaning agents.

The liquid constituents of washing and / or cleaning agents include, in particular, nonionic surfactants which are in liquid, ie pumpable and flowable, form at the process temperature. These nonionic surfactants preferably include addition products of 1 to 12 moles of ethylene oxide with primary C ₁₂ -C ₁₈ fatty alcohols and their mixtures, such as coconut oil, tallow oil or oleyl alcohol, or with primary alcohols (oxo alcohols) branched with methyl in the 2-position. In particular, C ₁₂ -C ₁₄ alcohols with 3 EO or 4 EO, C ₉ -C ₁₁ alcohol with 7 EO, C ₁₃ -C ₁₅ alcohols with 3 EO, 5 EO, 7 EO or 8 EO, C ₁₂ - C ₁₈ alcohols with 3 EO, 5 EO or 7 EO and mixtures thereof, such as mixtures of C ₁₂ -C ₁₄ alcohol with 3 EO and C ₁₂ -C ₁₈ alcohol with 5 EO.

The degrees of ethoxylation given represent statistical mean values which, for a specific product, are an integer or a fraction can. Preferred alcohol ethoxylates have a restricted homolog distribution (narrow range ethoxylates, NRE).

The content of the ethoxylated fatty alcohols in the finished granules is preferably 5 to 15% by weight. In a preferred embodiment, the liquid nonionic surfactants are used in a mixture with lower polyalkylene glycols which are derived from straight-chain or branched glycols having 2 to 6 carbon atoms. Preferred lower polyalkylene glycols are polyethylene glycols or polypropylene glycols which have a relative molecular mass between 200 and 12,000, in particular between 200 and 4,000, for example up to 2,000. The weight ratio of liquid nonionic surfactant to lower polyalkylene glycol in these mixtures is preferably 10: 1 to 1: 1.

The preferred aqueous mixtures also include aqueous alkyl glycoside pastes in which alkyl glycosides of the general formula RO (G) _x are used, in which R is a primary straight-chain or aliphatic radical with 8 to 22, preferably 12 to 18 C, methyl-branched in the 2-position -Atoms means and G is the symbol which stands for a glycose unit with 5 or 6 carbon atoms, preferably for glycose. The degree of oligomerization X, which indicates the distribution of monoglycosides and oligoglycosides, is any number between 1 and 10 and is preferably 1.2 to 1.4.

The preferred aqueous solutions also include the solutions of (co) polymeric polycarboxylates already mentioned. They are preferably added in the first, low-speed mixer / granulator in order to obtain heavy granules. A reduction in the bulk density can preferably be achieved by adding this solution in the second, high-speed mixer / granulator.

Pumpable, aqueous suspensions of zeolites, which preferably contain stabilizers for these suspensions, can preferably be used in the first, low-speed mixer / granulator. The use of concentrated aqueous anionic surfactant solutions and anionic surfactant pastes is also particularly preferred. These are preferably by neutralizing the Anionic surfactants in their acid form with highly concentrated aqueous bases, for example a 45 to 55% strength by weight sodium hydroxide solution, are produced in a commercially available rotor-stator machine, for example a Supraton ^(R) , or a stirred kettle. The additional concomitant use of nonionic surfactants is particularly preferred, the nonionic surfactants preferably being used in amounts such that the viscosity of the anionic surfactant pastes is reduced and thus their processability, in particular pumpability and flowability, is improved. These mixtures have a pH of at least 7.0, preferably from 7.5 to 12, and are added as constituents of the granulating liquid either in the first or in the second mixer / granulator. It is preferred that 8 to 20% by weight, preferably 10 to 18% by weight, based in each case on the total amount of the constituents used, of these anionic surfactant-nonionic surfactant mixtures are added, in particular in the first, low-speed mixer / granulator.

After the two-stage granulation, a drying stage can be added. This is not necessary if the granulating liquid contains no water, or is not absolutely necessary if the granulating liquid contains water only in small amounts, for example up to 12% by weight, based on the total amount of the constituents used. The amount of water tolerable without drying depends heavily on the overall composition. However, if the granulating liquid contains water, irrespective of the amount, the subsequent drying step is preferred. In particular, this drying is carried out in the fluidized bed at supply air temperatures below 180 ° C. The granulating liquid preferably contains only so much water that under these conditions a maximum of 15% by weight, based on the total amount of the constituents used, of water evaporate.

The continuous process according to the invention is not only distinguished by the fact that it enables the targeted setting of a desired bulk density of the granules produced; granules are also obtained which are distinguished by a very homogeneous grain spectrum with small coarse grain fractions, the fraction of granules with a diameter above 2 mm and in particular above 1.6 mm being preferred is a maximum of 12% by weight and in particular a maximum of 10% by weight (sieve analysis). These outstanding properties are achieved in particular when the degree of filling of the first mixer / granulator is set to 10 to 80%, preferably to 20 to 70% and the second mixer / granulator with high peripheral speeds of approximately 25 m / s to approximately 30 m / s is operated.

Existing coarse-grained fractions, that is to say granules with a diameter above 2 mm, preferably with a diameter above 1.6 mm, are preferably screened off and can advantageously be returned to the continuous production process after comminution, for example in a mill. It is preferred to return the crushed coarse particles to the sieve and thus to feed further finished granules. It is also possible to recycle crushed coarse particles or fine particles, i.e. granules with a diameter of less than 0.1 mm, in every granulation stage.

The granules obtained by the process according to the invention can be used directly as detergents and / or cleaning agents and / or they are mixed with further amounts, preferably small amounts, for example in the range from 2 to 10% by weight, based on the total amount of the constituents used , sprayed on liquid nonionic surfactants or nonionic surfactant mixtures in a manner known per se and / or they are mixed in a preparation step with further constituents, preferably granular and in particular granular and compacted constituents of detergents and cleaning agents. The other granular constituents include, for example, compacted bleach or bleach activator granules, enzyme granules, foam inhibitor granules, preferably concentrated foam inhibitor granules and granular carriers for colorants and fragrances.

Serve as bleach activators, for example, with H ₂ O ₂ which form organic peracids N-acyl or O-acyl compounds, preferably N, N'-tetraacylated diamines, also carboxylic anhydrides and esters of polyols such as glucose pentaacetate. The bleach activators contain bleach activators in the usual range, preferably between 1 and 10% by weight and in particular between 2 and 8% by weight. Particularly preferred Bleach activators are N, N, N ', N'-tetraacetylethylenediamine (TAED) and 1,5-diacetyl-2,4-dioxo-hexahydro-1,3,5-triazine (DADHT).

Suitable enzymes are those from the class of proteases, lipases, amylases, cellulases or mixtures thereof. Enzymes obtained from bacterial strains or fungi such as Bacillus subtilis, Bacillus licheniformis and Streptomyces griseus are particularly suitable. Proteases of the subtilisin type and in particular proteases which are obtained from Bacillus lentus are preferably used. Their proportion can be about 0.2 to about 2% by weight. The enzymes can be adsorbed on carriers and / or embedded in coating substances in order to protect them against premature decomposition.

Suitable stabilizers, in particular for per-compounds and enzymes, are, for example, the salts of polyphosphonic acids, in particular 1-hydroxyethane-1,1-diphosphonic acid (HEDP).

Suitable foam inhibitors are, for example, soaps of natural or synthetic origin, which have a high proportion of C ₁₈ -C ₂₄ fatty acids. Suitable non-surfactant-like foam inhibitors are, for example, organopolysiloxanes and their mixtures with microfine, optionally silanized silica, and paraffins, waxes, microcrystalline waxes and their mixtures with silanized silica. Mixtures of various foam inhibitors are also advantageously used, for example those made of silicone, paraffins or waxes. It is also possible for silicone oils and / or paraffin oils to be used in the two-stage granulation process according to the invention and preferably in the first, low-speed mixer / granulator.

Other components of detergents also include optical brighteners. As optical brighteners, the agents can contain derivatives of diaminostilbenedisulfonic acid or its alkali metal salts. Suitable are, for example, salts of 4,4'-bis (2-anilino-4-morpholino-1,3,5-triazin-6-yl-amino) stilbene-2,2'-disulfonic acid or compounds of the same structure which are used instead of Morpholino group, a diethanolamino group, a methylamino group, an anilino group or one Wear 2-methoxyethylamino group. Brighteners of the substituted 4,4'-distyryl-di-phenyl type may also be present, for example the compound 4,4'-bis (4-chloro-3-sulfostyryl) diphenyl. Mixtures of the aforementioned brighteners can also be used. Particularly uniform white granules are obtained if, in addition to the usual brighteners, the agents are also used in customary amounts, for example between 0.1 and 0.5% by weight, preferably between 0.1 and 0.3% by weight, contains, for example, 10 ^-6 to 10 ^-3 % by weight, preferably around 10 ^-5 % by weight, of a blue dye. A particularly preferred dye is Tinolux ^(R) (commercial product from Ciba-Geigy).

The optical brighteners or the mixtures of optical brightener and dye are preferably dissolved in ethoxylated nonionic surfactants and sprayed onto the granules produced by the process according to the invention in a known manner.

The granular detergents and / or cleaning agents produced in this way and having advantages generally have a bulk density between 600 and 1100 g / l, preferably between 700 and 950 g / l and, after sieving the coarse-grained fractions, preferably above 1.6 mm in particular between 750 and 850 g / l. Despite the possibly high proportions of ethoxylated nonionic surfactants, the granules are non-greasy, dust-free and, after drying, if appropriate, have a proportion of granules with a diameter above 1.6 mm of at most 25% by weight, preferably at most 20% by weight and in particular from 6 to 12% by weight, which is screened off and returned.

The content of anionic and nonionic surfactants in the granules is preferably 10 to 40% by weight and in particular 15 to 30% by weight, in each case based on the finished granules, and 20 to 60% by weight, preferably 25 to 55% by weight. -%, each based on the finished granulate and calculated as an anhydrous active substance, on builder substances. In particular, the finished granules have a content of 7 to 15% by weight of nonionic surfactants and 0 to 20% by weight, preferably 0 to 10% by weight, of free, ie non-chemically or non-physically bound water .

Examples Example 1:

In a ploughshare mixer from the company Lödige at peripheral speeds of the tools of 4 m / s and at a temperature which did not exceed 35 ° C., 41% by weight of water-containing zeolite NaA (Wessalith P ^(R) , commercial product from Degussa, Federal Republic of Germany ), 7.01% by weight of sodium carbonate and 28.35% by weight of a spray-dried granulate of the composition given below and homogenized with 7.07% by weight of a 30% by weight aqueous solution of a (co) polymer Polyacrylate (Sokalan CP5 ^(R) , commercial product from BASF, Federal Republic of Germany) and with 16.57% by weight of a mixture (neutralizate) of 8.18% by weight of Cg-C13-alkylbenzenesulfonic acid, 2.32% by weight % of a 50 wt .-% aqueous sodium hydroxide solution and 6.07 wt .-% of a C ₁₂ -C ₁₈ fatty alcohol sprayed with 5 ethylene oxide groups (E0). The fill level of this low-speed mixer was about 50%. The residence time of the ingredients in this mixer was about 3 minutes. The pregranules were then granulated in a Schugi ring bed mixer for a maximum of 1 second at peripheral speeds of the ring bed of about 30 m / s and at temperatures of 35 ° C. and dried in a fluidized bed at supply air temperatures of 130 ° C. The finished non-greasy, free-flowing and non-dusting granules had a bulk density of 860 g / l. The proportion of the dried granules with a diameter above 1.6 mm was below 12% by weight before sieving.

Grain spectrum (sieve analysis) in% by weight: > 1.6 mm > 0.8 mm > 0.4 mm > 0.2 mm > 0.1 mm <0.1 mm 9.1 28.7 32.9 26.6 2.7 -

These granules were mixed with other constituents of washing and / or cleaning agents such as perborate tetrahydrate, bleach activator, foam inhibitor granules, enzyme, nonionic surfactant and optical brightener.

The spray-dried granules used in the low-speed mixer / granulator had the following composition: 10th % By weight C ₉ -C ₁₃ alkylbenzenesulfonate, sodium salt 4th % By weight C ₁₂ -C ₁₄ fatty acid soap, sodium salt 2.5 % By weight C ₁₂ -C ₁₈ fatty alcohol with 5 EO 20.0 % By weight Polyacrylate, sodium salt, (Sokalan CP5 ^(R) ) 9.0 % By weight Sodium silicate, Na ₂ O: SiO ₂ 1: 2.0 (?) 42.5 % By weight sodium 2.0 % By weight 1-hydroxyethane-1,1-diphosphonate, sodium salt rest Water, dye, optical brightener

Example 2:

Example 1 was repeated. However, the pre-granulate was produced without the Sokalan ^(R) CP 5 solution. The sokalan was added in the form of a 30% by weight aqueous solution via nozzles during the second granulation step. The bulk density of these granules after drying and after sieving was 720 g / l. The coarse grain fraction above 1.6 mm was 6% by weight.

Example 3:

Example 2 was repeated. However, the second granulation step was carried out at peripheral speeds of the ring layer of 17 m / s. The bulk density of these granules after drying and after sieving was 621 g / l. The coarse grain fraction above 1.6 mm was 21% by weight.

Example 4:

Example 1 was repeated. The temperature of the pre-granulate was 48 ° C. when entering the second granulation stage. The bulk density of these granules was 830 g / l.

Example 5:

Example 1 was repeated. The residence time in the first mixer was 4 minutes while simultaneously reducing the Sokalan ^(R) CP 5 solution to 6% by weight. After drying and sieving 23% by weight of coarse particles above 1.6 mm, a bulk density of 930 g / l was obtained.

Claims (12)

1. A process for the continuous production of a granular detergent and/or cleaning composition of high apparent density by two-stage granulation in two mixer/ granulators arranged in tandem, characterized in that 40 to 100% by weight, based on the total quantity of constituents used, of the solid and liquid constituents are pregranulated in a first low-speed mixer/granulator, through which the product flows horizontally and in which granulation is possible at peripheral speeds of the mixing tools of 2 m/s to 7 m/s, and the initial granules from the first granulation stage are optionally mixed with the remaining solid and/or liquid constituents and converted into granules in a second, high-speed mixer/granulator, through which the mixture to be granulated flows vertically and of which the mixing tools can be operated at peripheral speeds of about 8 m/s, the granules formed being plastic to the extent that they can be compacted in the second granulation stage and the percentage of granules larger than 2 mm in diameter being less than 25% by weight.
2. A process as claimed in claim 1, characterized in that granulation in the first mixer/granulator is carried out for 0.5 to 10 minutes and, in the second mixer/granulator, for 0.1 to 30 seconds, preferably for up to 10 seconds and more preferably for 0.5 to 2 seconds at peripheral speeds of 8 m/s to 35 m/s.
3. A process as claimed in claim 1 or 2, characterized in that the temperature of the initial granules on entering the second granulation stage is between 30°C and 60°C.
4. A process as claimed in any of claims 1 to 3, characterized in that at least part of the constituents used for granulation in the first mixer/granulator, preferably 10 to 100% by weight, based on the solid constituents used in the first mixer/granulator, is used in the form of granules, the percentage content of these granules, preferably spray-dried granules, being from 10 to 40% by weight, based on the formulation as whole.
5. A process as claimed in any of claims 1 to 4, characterized in that 40 to 100% by weight, preferably 60 to 100% by weight and, more preferably, up to 95% by weight of the solid and liquid constituents are pregranulated in the first mixer/granulator and subsequently mixed with 0 to 60% by weight and preferably 5 to 40% by weight of remaining solid and/or liquid constituents and converted into the optionally still moist granules in the second mixer/granulator.
6. A process as claimed in any of claims 1 to 5, characterized in that the granulation liquid, which optionally contains solid constituents in dissolved and/or suspended form, is used in quantities of 5 to 30% by weight, based on the total quantity of constituents used.
7. A process as claimed in claim 6, characterized in that water, aqueous solutions, nonionic surfactants present in liquid form at the process temperature and/or mixtures of aqueous solutions and nonionic surfactants, preferably a mixture of an aqueous anionic surfactant solution and nonionic surfactants, the mixture having a pH value of at least 7.0, are used as the granulation liquid.
8. A process as claimed in claim 6 or 7, characterized in that 0 to 20% by weight and preferably up to 10% by weight, based on the total quantity of constituents used, of granulation liquid, preferably a mixture of an aqueous anionic surfactant solution and nonionic surfactants and/or an aqueous polymeric polycarboxylate solution, is added in the second high-speed mixer/granulator.
9. A process as claimed in any of claims 1 to 8, characterized in that the filling level of the first mixer/granulator is adjusted to 10 to 80% and the second mixer/granulator is operated at high peripheral speeds of around 25 m/s to around 30 m/s.
10. A process as claimed in any of claims 1 to 9, characterized in that, after the two-stage granulation, the granules are dried, preferably in a fluidized bed at feed air temperatures below 180°C, at most 15% by weight, based on the total quantity of constituents used, of water evaporating.
11. A process as claimed in any of claims to 10, characterized in that the granules obtained are mixed with other constituents of detergents and/or cleaning compositions in a processing step.
12. A process as claimed in any of claims 1 to 11, characterized in that granules with an apparent density in the range from 600 to 1100 g/l, preferably in the range from 700 to 950 g/l and more preferably in the range from 750 to 850 g/l are produced, granules larger than 1.6 mm in diameter being removed by sieving and recycled after the optional drying step, the percentage by weight of these granules being at most 25% by weight, preferably at most 20% by weight and, more preferably, from 6 to 12% by weight.