EP0633923B1 - Granular, phosphate-free additive containing non-ionic surface-active agents for washing and cleaning agents - Google Patents

Abstract

The aim is to produce an additive for granular and phosphate-free washing and cleaning agents, which contains non-ionic surface-active agents and which has both a better rinsing behaviour and a higher self-ignition temperature, i.e. lower combustibility. This is achieved with a granular, phosphate-free additive which contains: (A) 10-70 % by weight sodium perborate monohydrate with a mean granular size of between 0.2 and 1.2 mm; (B) 25-80 % by weight of a granular mixture with a mean grain size of between 0.2 and 1.2 mm, of which at least 75 % by weight is anorganic and free from peroxygen and contains 45-75 % by weight of synthetic, compact-grained zeolite (in relation to anhydrous substance in component B), 0-30 % by weight sodium sulphate and 1-12 % by weight homopolymer or copolymer carboxylic acid salts; (C) 5-30 % by weight non-ionic surface active agents bonded to the granular components (A) and (B), (B) containing 2-10 % by weight (in relation to the anhydrous substance in component B) of a layered silicate.

Description

The invention relates to a granular additive for washing and cleaning agents, which consists of two granular powder components of a defined composition, on which liquid, semi-solid or solid nonionic surfactants are adsorbed. Both powder components have a porous structure and can absorb up to 30% by weight, based on the additive, of such nonionic surfactants without the free-flowing properties suffering.

As is known, nonionic surfactants have a very high cleaning power, which makes them particularly suitable for use in low-temperature detergents. However, their proportion cannot be increased significantly beyond 8 to 10 percent by weight in the generally customary production of detergents by spray drying, since this would otherwise result in excessive smoke formation in the exhaust air from the spray towers and inadequate pouring properties of the spray powder. Processes have therefore been developed in which the liquid or melted nonionic surfactant is mixed onto the previously spray-dried powder or sprayed onto a carrier substance. Both water-soluble builder substances, in particular spray-dried phosphates, carbonates, bicarbonates, soluble silicates and borates, and water-insoluble builder substances, such as sodium aluminosilicate (zeolite) and silicon dioxide (aerosil), have been proposed as the carrier substance, but the known agents often have only a limited adsorption capacity and certain application technology disadvantages on. In addition, phosphates are often undesirable because of their eutrophic properties. Fine powdered zeolites also have only a limited absorption capacity for liquid substances, while special adsorbents such as diatomaceous earth and Aerosil ^® , as inert components, do not contribute to the washing effect.

DE-A-24 18 294 discloses detergents which consist of a powder component obtained by hot spray drying and granular sodium perborate tetrahydrate, the latter being impregnated with a defined mixture of nonionic surfactants. Due to the selection of non-ionic surfactants, the granulate is dust-free and free-flowing. According to EP-A-34 194, the perborate tetrahydrate is treated with nonionic surfactants which contain both ethylene glycol ether groups and propylene glycol ether groups. In addition to good flowability, the granules are particularly characterized by being odorless.

DE-A-25 07 926 contains examples of the preparation of premixes, powder mixtures of aluminosilicate (zeolite), perborate and optionally also a bleach activator being sprayed with nonionic surfactants. The resulting granules are then mixed with other powder components, in particular tower spray powder. Here, a certain stickiness of the granules disturbs, which can also be transferred to the overall mixture, especially if the admixed tower spray powder contains no phosphates.

If one tries to replace the sodium perborate tetrahydrate in these granules with sodium perborate monohydrate, which is known to have better solubility in cold water and therefore has advantages in the low-temperature washing range, additional difficulties arise. Above a certain critical amount of adsorbed nonionic surfactant, the ignition range of the mixture is reduced to such an extent that, under unfavorable conditions, the mixtures can self-ignite even at room temperature.

EP-A-168 102 discloses a process for producing high-density detergents in which nonionic surfactants are sprayed onto a powder mixture of sodium perborate monohydrate, zeolite and other builder substances. In this spray mixing process, granulation of the base powder occurs at the same time. Another part of the total nonionic surfactants used is sprayed onto a second powder component which is free of sodium sulfate and consists of spray-dried granules, the usual surfactants, builder substances and others Contains detergent ingredients. Both the perborate-containing base powder and the spray-dried powder component contain considerable amounts of sodium tripolyphosphate in the agents according to the examples. As already stated, such a base powder of perborate and powdered zeolite, especially if it is free from tripolyphosphate, leads to the formation of sticky, poorly pourable granules after the application of large amounts of nonionic surfactants. In order to be able to incorporate larger amounts of these surfactants nevertheless, it is proposed to treat not only the base powder but also the spray drying product in the same way in a spray mixing system. This process is therefore comparatively cumbersome since a much larger product stream has to be passed through the spray mixing plant. The problem of spontaneous combustion does not arise in this process, since the proportion of perborate monohydrate in the base powder is not very high and water is sprayed on at the same time with the nonionic surfactant.

On the other hand, absorbent carrier grains are known which consist of several components and are usually produced by spray drying. Examples of these are the agents according to US-A-3 849 327, US-A-3 886 098 and US-A-3 838 027 and US-A-4 269 722 (DE-A-27 42 683). However, these carrier grains, developed especially for the adsorption of nonionic surfactants, contain considerable amounts of phosphates, which limits their possible uses. Phosphate-free carrier grains are known from DE-A-32 06 265 and DE-A-32 06 379. They consist essentially of sodium carbonate or hydrogen carbonate, zeolite, sodium silicate, bentonite and polyacrylate. The high proportion of carbonates, however, favors the formation of calcium carbonate in hard water, while the sodium silicate in connection with zeolite considerably deteriorates the dispersibility of the grains in water.

EP-A-184 794 discloses a granular adsorbent which is able to absorb high proportions of liquid to pasty detergent constituents, in particular nonionic surfactants, and (based on anhydrous substance) 60 to 80% by weight of zeolite, 0.1 to 8% by weight. -% sodium silicate, 3 to 15 wt .-% of homo- or copolymers of acrylic acid, methacrylic acid and / or maleic acid, 8 to 18 wt .-% water and optionally up to 5 wt .-% contains nonionic surfactants and can be obtained by spray drying. In practice, it has been shown that in washing machines with poorly designed washing-in devices, the products do not completely detach during the washing-in phase and leave residues. This worsened washing-in behavior is not only shown by the particles in question themselves, but can also have an influence on the solubility or the washing-in behavior of the other powdered detergent components. The result of this is that a powder mixture which is intrinsically easy to flush in becomes difficult to flush in overall if it additionally contains such a powder component in the mixture.

EP-A-425 804 discloses a granular, nonionic surfactant-containing additive for detergents and cleaning agents, which has improved washing-in behavior and consists of a granular adsorbent (I) and nonionic surfactants (II) adsorbed thereon, where (I) 50 to 75% by weight of finely crystalline zeolite, 2 to 10% by weight of a layered silicate, 3 to 15% by weight of the sodium salt of a (co) polymeric carboxylic acid, optionally up to 10% by weight of sodium sulfate and up to 3 Wt .-% of a surfactant and the rest contains water and minor components and the weight ratio of adsorbent (I) to nonionic surfactants (II) is 2: 1 to 20: 1.

International patent application W0 90/14412 describes granular adsorbents which have a high adsorption capacity for nonionic surfactants and which, together with these, have an improved dissolving and flushing behavior. These granular, free-flowing and phosphate-free detergent additives contain (A) 10 to 70% by weight sodium perborate monohydrate, which has an average particle size of 0.2 to 1.2 mm, (B) 25 to 80% by weight of a granular, an average grain size of 0.2 to 1.2 mm mixture which is at least 75% by weight inorganic and free of peroxygen and (based on the anhydrous substance in component B) 45 to 75% by weight. contains synthetic, fine crystalline zeolite, 0 to 30% by weight of sodium sulfate and 1 to 12% by weight of salts of homopolymeric or copolymeric carboxylic acids, (C) 5 to 30% by weight of nonionic surfactants which are attached to the granular components (A ) and (B) are bound.

Optionally, but with advantages, component (B) contains a water-soluble soap, which significantly improves the washing-up behavior in the washing machine. However, it is disadvantageous that the soap-containing additive has a lower absorbency for nonionic surfactants and has a lower autoignition temperature or increased flammability.

The object of the invention was to provide an additive for granular and phosphate-free detergents and cleaning agents which contains nonionic surfactants and which has both improved wash-in behavior and an increased autoignition temperature or a reduced flammability.

• (A) 10 bis 70 Gew.-% Natriumperborat-monohydrat, das eine mittlere Korngröße von 0,2 bis 1,2 mm aufweist,
• (B) 25 bis 80 Gew.-% eines granularen, eine mittlere Korngröße von 0,2 bis 1,2 mm aufweisenden Gemisches, das mindestens zu 75 Gew.-% anorganischer Natur und frei von Persauerstoff ist und (auf wasserfreie Substanz in Komponente B bezogen) 45 bis 75 Gew.-% synthetischen, feinkristallinen Zeolith, 0 bis 30 Gew.-% Natriumsulfat und 1 bis 12 Gew.-% Salze homopolymerer bzw. copolymerer Carbonsäuren enthält,
• (C) 5 bis 30 Gew.-% an nichtionischen Tensiden, die an den granularen Komponenten (A) und (B) gebunden sind, wobei (B) 2 bis 10 Gew.-%, bezogen auf die wasserfreie Substanz in Komponente (B), eines Schichtsilikats enthält.

The invention accordingly relates to a granular and phosphate-free additive for detergents and cleaning agents, comprising

• (A) 10 to 70% by weight sodium perborate monohydrate, which has an average grain size of 0.2 to 1.2 mm,
• (B) 25 to 80% by weight of a granular mixture having an average grain size of 0.2 to 1.2 mm, which is at least 75% by weight inorganic in nature and free of peroxygen and (on anhydrous substance in component B related) contains 45 to 75% by weight of synthetic, finely crystalline zeolite, 0 to 30% by weight of sodium sulfate and 1 to 12% by weight of salts of homopolymeric or copolymeric carboxylic acids,
• (C) 5 to 30% by weight of nonionic surfactants which are bound to the granular components (A) and (B), where (B) 2 to 10% by weight, based on the anhydrous substance in component (B ), a layered silicate.

The granular components (A) and (B) and the finished agent have an average particle size of 0.2 to 1.2 mm, preferably 0.3 to 1 mm, in the interest of good flowability and trouble-free flushing behavior. In particular, the proportion of particles in the composite with a grain size of less than 0.05 mm is less than 1% by weight, preferably less than 0.1% by weight, the fraction with a grain size below 0.1 mm less than 2% by weight, preferably less than 1% by weight, the fraction with a grain size above 2 mm less than 5% by weight .-%, preferably less than 1 wt .-% and the proportion with a grain size above 1.2 mm less than 10 wt .-%, preferably less than 5 wt .-%. Both components can have the same or a different grain size within the specified limits. Mixing and treating them together with nonionic surfactants can result in a slight agglomeration of the particles, in particular by attaching finely divided components to larger grains, and thus overall a slight increase in the average grain size.

The proportion of sodium perborate monohydrate (component A) is preferably 20 to 60% by weight and in particular 30 to 50% by weight. The proportion of component (B) is preferably 35 to 70% by weight and in particular 40 to 60% by weight. The proportion of the nonionic component (C) is preferably 7 to 25% by weight and in particular 10 to 20% by weight.

The perborate monohydrate is preferably used as loose, expanded pellets with a liter weight of 450 to 650 g / l, preferably 500 to 600 g / l. Such granules are characterized by a good adsorption capacity for liquid to lard-like nonionic surfactants. Loading the granules with the nonionic surfactants generally increases the bulk density by about 50 to 200 g / l, which is in the interest of a higher total bulk weight and a saving in packaging and transport volume.

Component (B) likewise preferably consists of a granular, porous material, as can be obtained by spray drying aqueous slurries of water-insoluble or water-soluble salts or salt mixtures. It contains synthetic zeolite of the NaA type in proportions of 45 to 75, preferably 50 to 72% by weight and in particular 55 to 70% by weight (based on anhydrous substance). Mixtures of zeolite NaA and NaX can also be used, the proportion of the zeolite NaX in such mixtures advantageously being below 30%, in particular below 20%. Suitable zeolites have no particles larger than 30 µm and consist of at least 80% particles less than 10 µm in size. Their average particle size (volume distribution, measurement method: Coulter Counter) is in the range from 1 to 10 µm. Their calcium binding capacity, which is determined according to the information in DE-A-24 12 837, is in the range from 100 to 200 mg CaO / g. The zeolites can still contain excess alkali from their production. The water content of synthetic zeolites is usually 18 to 22% by weight.

$${\text{(OH)}}_{\text{4}}{\text{Si}}_{\text{8-y}}{\text{Al}}_{\text{y}}{\text{(Mg}}_{\text{6-z}}{\text{Li}}_{\text{z}}{\text{)O}}_{\text{20}}\text{Hectorit}$$

$${\text{(OH)}}_{\text{4}}{\text{Si}}_{\text{8-y}}{\text{Al}}_{\text{y}}{\text{(Mg}}_{\text{6-z}}{\text{Al}}_{\text{z}}{\text{)O}}_{\text{20}}\text{Saponit}$$

mit x = 0 bis 4, y = 0 bis 2, z = 0 bis 6.Suitable layered silicates, which belong to the group of water-swellable smectites, are, for example, those of the general formula $${\text{(OH)}}_{\text{4th}}{\text{Si}}_{\text{8-y}}{\text{Al}}_{\text{y}}{\text{(M}}_{\text{8x}}{\text{Al}}_{\text{4-x}}{\text{)O}}_{\text{20th}}\text{Montmorrilonite}$$

$${\text{(OH)}}_{\text{4th}}{\text{Si}}_{\text{8-y}}{\text{Al}}_{\text{y}}{\text{(Mg}}_{\text{6-z}}{\text{Li}}_{\text{e.g.}}{\text{)O}}_{\text{20th}}\text{Hectorite}$$

$${\text{(OH)}}_{\text{4th}}{\text{Si}}_{\text{8-y}}{\text{Al}}_{\text{y}}{\text{(Mg}}_{\text{6-z}}{\text{Al}}_{\text{e.g.}}{\text{)O}}_{\text{20th}}\text{Saponite}$$

with x = 0 to 4, y = 0 to 2, z = 0 to 6.

In addition, small amounts of iron can be incorporated into the crystal lattice of the layered silicates according to the above formulas. Furthermore, due to their ion-exchanging properties, the layered silicates can contain hydrogen, alkali and alkaline earth ions, in particular Na⁺ and Ca⁺⁺. The amount of water of hydration is usually in the range of 8 to 20% by weight and depends on the swelling condition or the type of processing. The particle size is in the range from 0.05 to 25 µm, usually less than 10 µm. Useful sheet silicates are known, for example, from US-A-3,966,629, US-A-4,062,647 (DE-A-23 34 899), EP-A-26 529 and EP-A-28 432. Layered silicates are preferably used which are largely free of calcium ions and strongly coloring iron ions due to an alkali treatment.

The layer silicate content of component (B) is preferably 3 to 7% by weight.

Another advantageous component of component (B) is sodium sulfate, which is calculated as an anhydrous substance and is present in proportions of 0 to 30% by weight, preferably 1 to 25 and in particular 3 to 20% by weight. The sodium sulfate contributes to a considerable improvement in the grain structure of component (B) and the washing-in behavior of the detergent additive and at the same time increases its bulk density, which results in the possibility of saving packaging and transport volume.

Another inorganic salt that can be combined with the zeolite is sodium carbonate, which can be present in proportions of up to 20% by weight, based on component (B). With regard to the flushing-in behavior, however, such mixtures are inferior to the mixtures of zeolite and sodium sulfate.

The content of component (B) in inorganic salts including zeolite should be at least 75% by weight, preferably at least 85% by weight (based on component B). In addition, component (B) contains organic salts which are of particular advantage for the grain structure, the grain stability and in particular for the washing-in behavior of the granules and their mixtures with other detergent constituents.

These organic salts which are contained in component (B) include the sodium or potassium salts, preferably the sodium salts of homopolymeric and / or copolymeric carboxylic acids. Suitable homopolymers are polyacrylic acid, polymethacrylic acid and polymaleic acid, with polyacrylic acid being preferred. Suitable copolymers are those of acrylic acid with methacrylic acid or copolymers of acrylic acid, methacrylic acid or maleic acid with vinyl ethers, such as vinyl methyl ether or vinyl ethyl ether. In such copolymeric acids in which one of the components has no acid function, the proportion thereof in the interest of sufficient hater solubility is not more than 50 mole percent, preferably less than 30 mole percent. Copolymers of acrylic acid or methacrylic acid with maleic acid, as described in more detail in EP-A-25 551, have proven to be particularly suitable. These are copolymers which contain 40 to 90% by weight of acrylic acid or methacrylic acid and 60 to 10% by weight of maleic acid. Such copolymers are particularly preferred, in which 45 to 85 percent by weight acrylic acid and 55 to 15 percent by weight maleic acid are present.

The molecular weight of the homopolymers or copolymers is generally 2,000 to 150,000, preferably 5,000 to 100,000. Their proportion in component (B) is, for example, up to 12% by weight, preferably 1.5 to 8% by weight. and in particular 2 to 5% by weight, calculated as the sodium salt. The resistance of the grains to abrasion increases with an increasing proportion of polyacid or its salts. With a proportion from 1.5% by weight, sufficient abrasion resistance is achieved in many cases. Mixtures with 2 to 5% by weight of sodium salt of polyacid have optimal abrasion properties.

In those cases in which the zeolite is used in the production of the granular component (B) not in powder or spray-dried form, but rather as a moist filter cake, it can contain dispersion stabilizers, as is the case in DE-A-25 27 388 are described in more detail. Suitable stabilizers are in particular nonionic surfactants with HLB values below 12, such as ethoxylated tallow alcohol with 3 to 8 EO. The proportion of these additives in the powder component (B) can, depending on the zeolite content, be up to 4% by weight, usually 0.3 to 3% by weight. In the final balance, this portion of component (C) is added.

The difference of up to 100% by weight is due to water, which is present in bound form and as moisture, the major amount being bound to the zeolite. A proportion of the water, which is about 8 to 18 wt .-% (based on the agent) can be removed at a drying temperature of 145 ° C. Another portion, which is between 4 and 8% by weight depending on the zeolite portion, is released at the annealing temperature by about 800 ° C. and corresponds to the water stored in the crystal lattice of the zeolite.

The average grain size of component (B) is 0.2 to 1.2 mm, the proportion of the grains below 0.05 mm less than 1% by weight, preferably less than 0.5% by weight and above 2 mm should not be more than 5% by weight. Preferably, at least 80% by weight, in particular at least 90% by weight, of the grains have a size of 0.1 to 1.2 mm, the proportion of the Grains between 0.1 and 0.05 mm, preferably not more than 3% by weight, in particular less than 1% by weight, the proportion of the grains between 0.1 and 0.2 mm less than 20% by weight , in particular less than 10% by weight and the proportion of the grains between 1.2 and 2 mm is not more than 10% by weight, in particular not more than 5% by weight. The bulk density of component (B) in the preferred embodiment is 400 to 680 g / l, preferably 450 to 650 g / l. The adsorption of the non-ionic surfactants also increases it by 50 to 200 g / l.

The nonionic surfactants adsorbed on the mixture of components (A) and (B) are those which are usually used in washing and cleaning agents. Other suitable additives are organic solvents, with which the cleaning ability of detergents and cleaning agents is improved, in particular with regard to greasy soiling, and which can in this way be incorporated into a granular cleaning agent without problems. However, other substances, such as fragrances, finishing agents, optical brighteners and anionic or cationic surfactants, can also be mixed into the mixture of components (A) and (B) after prior dissolution or dispersion in organic solvents or the liquid or molten nonionic surfactants. These substances penetrate into the porous grains together with the solvent or dispersant and are thus protected against interactions with other powder components.

Preferred detergent constituents which are bound to the granular mixture and are present together with this as a free-flowing mixture are liquid to pasty nonionic surfactants from the class of the polyglycol ethers, derived from alcohols with 10 to 22, in particular 12 to 18, carbon atoms. These alcohols can be saturated or olefinically unsaturated, linear or methyl-branched in the 2-position (oxo radical). Their reaction products with ethylene oxide (EO) or propylene oxide (PO) are water-soluble or water-dispersible mixtures of compounds with different degrees of alkoxylation. The number of EO or PO groups corresponds to the statistical mean for technical alkoxylates.

Examples of suitable ethoxylated fatty alcohols are C₁₂-₁₈ coconut alcohols with 3 to 12 EO, C₁₆₋₁₈ tallow alcohol with 4 to 16 EO, oleyl alcohol with 4 to 12 EO as well as ethoxylation products of appropriate chain and EO distribution available from other native fatty alcohol mixtures. From the series of ethoxylated oxo alcohols, for example, those of the composition C₁₂₋₁₅ + 5 to 10 EO and C₁₄-C₁₅ + 5 to 12 EO are suitable. Mixtures of low and highly ethoxylated alcohols are distinguished by an increased detergency against both greasy and mineral soiling, for example those made from tallow alcohol with 3 to 6 EO and tallow alcohol with 12 to 16 EO or C₁₃₋₁₅ oxo alcohol with 3 to 5 EO and C₁₂ ₋₁₄ oxo alcohol with 8 to 12 EO. Agents in which the adsorbed nonionic surfactants have both long hydrophobic residues and higher degrees of ethoxylation have particularly favorable flushing properties.

The bulk density of the additives according to the invention is preferably between 600 and 950 g / l, in particular between 650 and 850 g / l.

The advantages of the additives according to the invention lie above all in that they have an increased autoignition temperature or a lower flammability with comparable flushing behavior compared to soap-containing additives of the prior art. Compared to additives of the prior art, which contain zeolite and (co) polymeric polycarboxylates, but contain neither soap nor layered silicates, they have, depending on the amount of nonionic surfactant applied, an analogue to better auto-ignition temperature or flammability and better flushing behavior. An additional advantage of these additives is that they are more free-flowing than the additives mentioned in the prior art.

The preparation of component (B) in the preferred embodiment is based, for example, on an aqueous batch containing a total of 40 to 55% by weight of water-free ingredients, which is sprayed into a falling space by means of nozzles and by means of drying gases which have an inlet temperature of 150 to 280 ° C and an outlet temperature of 50 to 120 ° C, is dried to a removable moisture content at 145 ° C.

The aqueous batch can be prepared by mixing the dry or water-containing constituents with the addition of the water required for liquefaction. Instead of the salts of the polymeric carboxylic acids, the corresponding free acids can also be incorporated and the alkali required for salt formation can be added separately. The addition of alkali hydroxide, in particular NaOH, is also recommended in order to make the aqueous zeolite suspension or the slurry alkaline, i.e. adjust to a pH of at least 8 and provide a sufficient alkali excess so that the pH does not drop to less than 8 during spray drying. Such a pH reduction, which would lead to a loss of activity of the zeolite, can be caused by CO₂ in the dry gas. The addition of NaOH, which ensures a sufficient alkali reserve, can be, for example, up to 3% by weight. In general, 0.2 to 1% by weight is sufficient.

The content of water-free ingredients in the aqueous mixture is preferably 43 to 50% by weight. Its temperature is advantageously 50 to 100 ° C and its viscosity 2,000 to 20,000 mPas, usually 8,000 to 14,000 mPas. The atomization pressure is usually 20 to 120 bar, preferably 30 to 80 bar. The drying gas, which is generally obtained by burning heating gas or heating oil, is preferably conducted in countercurrent. When using so-called drying towers, into which the aqueous batch is sprayed in the upper part via several high-pressure nozzles, the inlet temperature, measured in the ring channel (ie immediately before entering the lower part of the tower), is 150 to 280 ° C, preferably 170 to 250 ° C . The exhaust gas laden with moisture leaving the tower usually has a temperature of 50 to 130 ° C., preferably 55 to 115 ° C. The spray drying is conducted so that the particle size of the spray product has the distribution given above. Existing fine and coarse grains are screened before further processing. It has been shown that the rinsing behavior of the adsorption impregnated with nonionic surfactants deteriorates with increasing proportion of fine grain.

Both powder components are combined to form a homogeneous mixture and then mixed with liquid or nonionic liquid or liquefied by heating Treated surfactants or surfactant mixtures. For faster distribution, the nonionic surfactant is expediently sprayed onto the agitated mixture. Heating the nonionic surfactant to temperatures between 35 and 60 ° C, preferably 40 to 50 ° C, accelerates the adsorption process. The abrasion resistance and constancy of shape of the grains is so high if the specified proportions or production conditions are observed that even the freshly prepared, but especially the cooled and possibly reheated, matured grains can be treated, mixed and conveyed with the liquid additives under the usual spray mixing conditions without the formation of fine fractions or coarser agglomerates.

The mixing of the two granular components and the subsequent spraying with nonionic surfactants can be carried out continuously or batchwise in conventional mechanical mixing devices, such as drum mixers, fluidized bed mixers or spray mixers. The mixing and spraying process can also be carried out in a single mixing apparatus with continuous operation, the combination of the two powder components in a first mixing section and the admixing of the nonionic component in a final mixing section. A particular advantage of the invention can be seen in the fact that the adsorption of the liquid nonionic surfactants and their diffusion into the interior of the grain takes place comparatively quickly. Shortly after leaving the mixing apparatus, the grain mixtures are fully free-flowing and can be processed without intermediate storage or time-consuming post-ripening processes.

After the application of the nonionic surfactant or the additives that may have been added, the grains can optionally be dusted with finely divided powders or coated on the surface. This can further improve the pourability and slightly increase the bulk density. Suitable powdering agents have a grain size of 0.001 to at most 0.1 mm, preferably less than 0.05 mm and can be present in proportions of 0.03 to 3, preferably 0.05 to 2% by weight, based on that with the additive loaded adsorbents are used. For example, finely powdered zeolites, silica airgel (Aerosil ^(R) ), colorless or colored pigments, such as titanium dioxide and other powder materials already proposed for powdering granules or detergent particles, such as finely powdered sodium tripolyphosphate, sodium sulfate, magnesium silicate and carboxylmethyl cellulose. In the products according to the invention, such treatment is generally not necessary, especially since the ability to be washed in is not improved thereby.

The granular adsorbents impregnated with the nonionic surfactants or with the mixtures of nonionic surfactant and additive can be mixed with further powdery to granular detergents or detergent components, as can be obtained, for example, by spray drying or granulation, or with bleaching agents or with bleaching detergents of known composition be mixed in any ratio. Here, their good flowability and their high grain stability are of great advantage, since an undesirable formation of abrasion and dust is avoided. The powder mixtures are in turn stable in storage and do not tend to clump or exude the nonionic surfactant. When used, they are particularly easy to flush in compared to known agents. In contrast to the information in EP-A-168 102, the admixed spray powders and granules can also contain sodium sulfate, which is often advantageous for their grain properties, especially in the absence of phosphates. These admixed detergent components are therefore preferably also phosphate-free. In addition, the absorbency of the granulate mixture according to the invention for nonionic surfactants is so high that an additional application of these surfactants to other mixture components is unnecessary.

Examples

The additives A1 and A2 according to the invention and the comparative additives V1 to V4 were examined in particular for their flammability and their flow behavior. All additives contained 40.9% by weight of perborate monohydrate with a bulk density of 460 g / l (sieve analysis: greater than 0.8 mm 0%, greater than 0.4 mm 48%, greater than 0.2 mm 47%, greater than 0.1 mm 5%, less than or equal to 0.1 mm 0%). The additives A1, V1 and V2 each contained 34.1% by weight of component (B); additives A2, V3 and V4 each contained 46.5% by weight of component (B). In the additives A1, V1 and V2, the mixtures of perborate monohydrate and component (B) were each sprayed with 25% by weight, based on the sprayed additive, of C₁₂-C₁₈ fatty alcohol with 5 EO; in the additives A2, V3 and V4, the mixtures of perborate monohydrate and component (B), each with 12.6% by weight, based on the sprayed additive, of C₁₂-C₁₈ fatty alcohol were sprayed with 5 EO.

The spray-dried component (B) had the composition given in Table 1 in the additives.

To determine the flammability, 50 g of the additives were piled up on a watch glass and touched with a Bunsen burner flame from above at an angle of 45 ° C. for 10 seconds from a distance.

The result given in Table 2 after the flame was switched off was determined visually. Table 1: Component (B) in A1 / A2 and V1 / V3 or V2 / V4 A1 / A2 V1 / V3 V2 / V4 Zeolite NaA (calculated as an anhydrous substance) 70.0 70.0 70.0 Tallow fatty alcohol with 5 EO 1.95 1.95 1.95 Laundrosil ^(R) DG-A (layered silicate treated with soda solution) 3.0 --- --- C₁₂-C₁₈ sodium fatty acid soap --- 3.0 --- Sodium sulfate --- --- 3.0 Sokalan CP5 ^(R) (acrylic acid-maleic acid polymer, sodium salt) 4.0 4.0 4.0 water 20.6 20.6 20.6 Sodium hydroxide 0.43 0.43 0.43 Silicone oil 0.02 0.02 0.02 Bulk density in g / l 610 460 575 Sieve analysis (in%) greater than 1.6 mm 0 0 0 0.8 mm 0 5 1 0.4 mm 17th 38 16 0.2 mm 61 37 55 0.1 mm 21 12th 26 Smaller or equal 0.1 mm 1 8th 2nd A1 V1 V2 A2 V3 V4 Bulk density in (g / l) 780 700 770 680 605 670 Flammability after switching off the Bunsen burner flame little burns burns more than A1 and V2 burns with normal flame Flame goes out smoldering through Flame goes out after 10 seconds Flowability (in%) 106 91 100 106 96 102 Sieve analysis over 1.6 mm 0 0 0 0 0 0 0.8 mm 1 1 0 1 1 0 0.4 mm 31 35 37 26 31 27 0.2 mm 54 49 51 54 49 55 0.1 mm 14 14 12th 17th 16 17th less than or equal to 0.1 mm 0 1 0 2nd 3rd 1 The induction behavior of A1 was roughly comparable to the behavior of V1 and better than that of V2; The flushing behavior of A2 was comparable to that of V3 and better than that of V4.

To determine the flow behavior, 1 liter of the powder was filled in a funnel closed at its outlet opening with the following dimensions: Diameter of the top opening 150 mm Diameter of the lower opening 10 mm Height of the conical funnel area 230 mm Height of the cylindrical area below 20 mm Inclination angle of the conical area 73 ° Dry sea sand with the following grain spectrum was chosen as the reference substance: mm over 1.5 to 0.8 to 0.4 up to 0.2 to 0.1 % By weight 0.2 11.9 54.7 30.1 3.1 The flow time of the dry sand after opening of the outflow opening (51 seconds) was set at 100%. The flowability of the additives is given in%, based on this 100% value.

Claims (7)

1. A granular phosphate-free detergent additive containing

   (A) 10 to 70% by weight of sodium perborate monohydrate with an average particle size of 0.2 to 1.2 mm,

   (B) 25 to 80% by weight of a granular mixture with an average particle size of 0.2 to 1.2 mm of which at least 75% by weight is inorganic and free from peroxygen and which contains (based on water-free substance in component B) 45 to 75% by weight of synthetic finely crystalline zeolite, 0 to 30% by weight of sodium sulfate and 1 to 12% by weight of salts of homopolymeric or copolymeric carboxylic acids,

   (C) 5 to 30% by weight of nonionic surfactants fixed to the granular components (A) and (B),

   characterized in that (B) contains 2 to 10% by weight, based on the water-free substance in component (B), of a layer silicate.
2. An additive as claimed in claim 1 in which the fraction with a particle size below 0.05 mm makes up less than 1% by weight and preferably less than 0.1% by weight, the fraction with a particle size below 0.1 mm makes up less than 2% by weight and preferably less than 1% by weight, the fraction with a particle size above 2 mm makes up less than 5% by weight and preferably less than 1% by weight and the fraction with a particle size above 1.2 mm makes up less than 10% by weight and preferably less than 5% by weight.
3. An additive as claimed in claim 1 or 2 containing 20 to 60% by weight and more particularly 30 to 50% by weight of component (A), 35 to 70% by weight and more particularly 40 to 60% by weight of component (B) and 7 to 25% by weight and more particularly 10 to 20% by weight of component (C).
4. An additive as claimed in one or more of claims 1 to 3, characterized in that the sodium perborate monohydrate used has an apparent density of 450 to 650 g/l and preferably 500 to 600 g/l.
5. An additive as claimed in one or more of claims 1 to 4, characterized in that 50 to 72% by weight (based on water-free substance) of component (B) consists of synthetic fine-particle zeolite containing bound water, 0 to 30% by weight of sodium sulfate, 1.5 to 8% by weight of homopolymeric or copolymeric polycarboxylic acids (expressed as sodium salt) and 3 to 7% by weight of a layer silicate and also bound water.
6. A process for the production of the additive claimed in one or more of claims 1 to 5, characterized in that a homogeneous dry mixture of components (A) and (B) is sprayed and at the same time mixed with a liquid component (C) or with a component (C) liquefied by heating.
7. A powder-form to granular, phosphate-free to lowphosphate detergent, characterized by a content of the detergent additive claimed in one or more of claims 1 to 5.