WO1996034081A1

WO1996034081A1 - Long shelf life granulate containing bleach activators and its production

Info

Publication number: WO1996034081A1
Application number: PCT/EP1996/001618
Authority: WO
Inventors: Hans Kruse; Volker Bauer; Dieter Jung
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1995-04-28
Filing date: 1996-04-18
Publication date: 1996-10-31
Also published as: DE19515233A1; EP0822974A1; ES2140087T3; DE59603355D1; EP0822974B1; ATE185593T1

Abstract

The granulate is made by granulating a damp powdered mixture of a powdered bleach activator, a powdered granulating agent and an aqueous solution thereof and/or of another granulating agent or an aqueous solution of other active substances of washing or cleaning agents or water by means of agglomerating the damp particles in a mixing granulator and subsequently drying the damp granulate. Before the damp granulate is dried to the desired residual humidity it is taken to another unit (a rounding machine) and caused to rub against one another and on the wall and/or the bottom of the rounding machine and at the same time become compacted to the extent where the granulates, after drying, have a powder density of at least 580 g/l and especially at least 630 g/1. Besides the high powder density, the granulates exhibit an improved degree of whitening and long shelf life on mixing with bleach and alkali-containing products.

Description

Laαerstable. Granules containing bleach activators and their production

The invention relates to a process for producing a storage-stable, bleach-activator-containing granulate as a component of an agent for textile washing or for cleaning agents by granulating a moist powdery mixture of a powdery bleach activator, a powdery granulating aid and an aqueous solution of the same and / or another granulating aid or an aqueous solution of other active substances of detergents or cleaning agents or water by agglomerating the moist particles in a mixing granulator and then drying the moist granules and, if appropriate, sieving oversize and fine particles.

In the known manufacturing process, a so-called ploughshare mixer (from Lödige) with a central, rotating shaft lying in a horizontal cylindrical housing, to which plowshare-shaped paddles are attached, can be used as a mixing granulator. The moist granules obtained after granulation can be dried in conventional dryers, e.g. B. in fluidized bed dryers. However, problems arise from the agglomeration of the already finished but still moist granules in the inlet area of the dryer.

Textile detergents and cleaning agents, e.g. B. agents for machine dishwashing, often contain inorganic peroxides and peroxohydrates as bleach-active compounds. The main representative is sodium perborate. It hydrolyzes in water to form hydrogen peroxide, thus enabling oxidative bleaching. However, the bleaching effect strongly depends on the temperature. Sodium perborate only has a clear bleaching effect from around 60 ° C.

At lower temperatures, the oxidation effect of the inorganic per compounds can be improved by adding activators. These are usually acylating agents which form organic peracids in an alkaline medium in the wash liquor with hydrogen peroxide. These show due to their higher oxidation potential compared to hydrogen peroxide in the area of low temperatures a good bleaching effect. A known example of such a bleach activator is tetraacetylethylene diamine (TAED).

The bleach activators, for example from the class of the N- and O-acyl compounds, are, however, highly sensitive to hydrolysis, especially in the presence of the alkalis which are customary in washing and cleaning agents. The problems resulting from this for the storage stability of the textile detergents are further exacerbated by the fact that the activators are often poorly soluble in water, so that finely powdered materials with rapid dispersibility are used. Due to the large surface area, the finely divided form enables the activators to be hydrolysed during storage. In other words, the sensitivity to hydrolysis leads to an accelerated breakdown of the active oxygen content of the bleaching agent. The loose structure of the known bleach activator granules, the bulk density of which is about 530 to 550 g / l, also allows "migrating" water to penetrate into the interior of the granulate.

To solve this problem, the bleach activator is added to the dry detergent or cleaning agent mixtures in practice as separately produced granules. The storage stability is also increased by mixing the dry, very finely divided bleach activator with a dry, also very finely divided pelletizing agent and only then moistening and granulating. Thus, in the process according to DE 30 11 998 C2, the bleach activator TAED is granulated with the granulating aid sodium carboxymethyl cellulose. The granulation aid, which is distributed homogeneously in the granulate, protects the finely divided bleach activator particles from the entry of migrating water and in this way reduces the sensitivity of the finished granulate to hydrolysis. However, a further increase in storage stability is desired.

Another aim is to improve the abrasion stability of the granules, that is to say the mechanical stability of the bleach activator granules, in order to keep the fine fraction resulting from transportation of the granules against one another as low as possible due to friction of the granules. What is also desired is an improvement in the visual impression of the finished detergent and cleaning agent granules, which is expressed in the desire for an increase in the degree of whiteness. The known activator granules namely have a slightly darker appearance than the detergent and cleaning agent granules to which they are added, so that there is no uniform white appearance. According to the inventors' knowledge, the dark appearance of the known granules is caused by the rough surface formed by the adhering very fine to coarser particles, the microscopic unevenness of which leads to a corresponding formation of shadows.

Another requirement arises from a special area of application of bleach activator granules. To reduce the proportion of packaging in solid and free-flowing detergents and cleaning agents, particularly high bulk densities are desirable. Such products can be manufactured in different ways.

Particularly high bulk densities of approximately 800 g / l and more are achieved in a method known from DE 39 26 253 A1. Here, compressed granules are formed from premixes of solid ingredients of detergents and cleaning agents with the addition of water-soluble, water-emulsifiable or water-dispersible plasticizers and / or lubricants. For this purpose, the premixes are processed into a homogeneous mass and pressed into strands at pressures between 25 and 200 bar via hole shapes with opening widths of the predetermined granule dimension. The emerging compacted strands are crushed to the predetermined granule dimension. The warm and moist cylindrical granules obtained from the extruder granulation are rounded off in a rounder (rounding device) with the addition of zeolite NaA powder as a powdering agent. After drying, sieving and mixing with the remaining ingredients, the final detergent product is obtained.

In addition to bleaching agents, the extrudates can also contain bleach activators, e.g. B. TAED included. However, since the extrudates contain the alkalis customary for detergents and the bleach activators of the inorganic peroxide compounds are very sensitive to hydrolysis in the presence of alkalis, it is advantageous not to add the bleach activators together with the other solid ingredients extrude, but to produce them separately as granules and add them to the dried extrudates.

However, the relatively loose activator granules produced in the known process (DE 30 11 998 C2) undesirably reduce the bulk density of the final detergent product. The difference in the density of the extrudates and the activator granules can also lead to segregation of the detergent end product.

Bleach activator granules with a bulk density approximating the extrudates mentioned and a corresponding grain shape are therefore desirable. For this purpose, DE 41 43 016 A1 proposes to produce the activator granules in the same way as the extrudates containing the main ingredients of the detergents. A practically anhydrous mixture of bleach activator, anionic surfactant, solubilization aid and, if appropriate, further additives is homogenized and extruded in the form of a strand using increased pressure. The emerging strands are cut into short pieces and rounded if necessary and, if desired, classified according to size. However, the additives required for extrusion disadvantageously limit the maximum possible activator content in the extrudate.

It is an object of the present invention to develop a production process for bleach activator granules which, compared to the known granules produced in the mixing granulator, has an increased bulk density and a significantly higher mechanical abrasion stability, and when mixed with granules, including the remaining ingredients of washing and cleaning agents Hydrolyze alkaline components much more slowly, i.e. cause a significantly lower breakdown of the active oxygen content of the detergent end product. In addition, significantly higher activator contents should be possible in the granules than in the known extrudate. Finally, the granules should no longer agglomerate in the inlet area of the dryer as in the known method.

This object is achieved according to the invention in the method mentioned at the outset by feeding the moist granules to the desired residual moisture to a further apparatus (rounder) and rubbing them against one another and on the wall and / or on the bottom of the rounder and can be compacted so strongly at the same time that the granules after drying have a bulk density of at least 580 g / 1, in particular at least 630 g / 1.

According to the invention, therefore, the technically relatively complex extrusion method, which works with increased pressures, is not used, but rather between the known process step of wet granulation in a mixing granulator, e.g. B. a ploughshare mixer, and the drying step, a further process step is inserted. Here, the granules are allowed to rub against each other and on the inner wall of a rounder for a sufficiently long time so that the rough surface of the particles that results from wet agglomeration is smoothed. At the same time, the impacts acting on a granule from all sides lead to a reduction in the geometric size, that is to say to a compression, and to a firm connection of the agglomerated, finely divided individual particles contained in the granule. The frequent collision also leads to an agglomeration of several moist granules and a subsequent rounding and thus to compact, rounded granules, that is to say an increase in grain size with a simultaneous increase in density. The result is an increased bulk density and a higher mechanical stability. This compression effect was summarized above under the term "compact".

The very frequent contact and collision of the moist granules with one another in the rounding step according to the invention requires a relatively high density of the granulate cloud in the fillet, which corresponds to a density of a resting bed, that is to say a very much smaller mean distance between the granules than, for example, in a fluidized bed.

In addition to increasing the bulk density and mechanical stability, the manufacturing method according to the invention shows further advantages. The moist granules contained after the rounding have a significantly lower tendency to agglomerate in the subsequent drying stage, which is usually carried out in a fluidized bed dryer, than in the known process (DE 30 11 998 C2) and under normal process conditions. The proportion of oversize is therefore considerably lower. Compared to the granulate produced in the known manner, the granulate according to the invention with a bulk density of about 580 to 700 g / 1 is about 50 to 150 g / l heavier. The bulk density of the granules produced according to the invention is thus just as high as that of the products produced by extrusion in accordance with DE 41 43016 A1.

Another advantage is the significantly higher whiteness. The smooth, rounded surface makes the granules appear optically lighter due to the lower formation of shadows, so that after mixing with the granules of the main constituents of the detergents and cleaning agents there is an optically uniform appearance.

The activator granules according to the invention showed further surprising effects. If the granules are mixed with the extrudates containing the main constituents of the detergents, an increase in bulk density which is disproportionate to the theoretical value is observed.

The sensitivity to hydrolysis of the granules according to the invention after mixing to give the final detergent or cleaning product and thus the breakdown of the active oxygen content of the finished detergent or cleaning agent was surprisingly significantly lower when using the granules according to the invention than when using the activator granules produced by known processes.

In an advantageous embodiment of the method according to the invention, the moist granules are allowed to rub and compact from below between the housing wall and the edge of the base plate in a rounder with a rotating, horizontal base plate while at the same time blowing in a working gas, in particular cold air. Such rounders are known and are available, for example, under the name "Marumerizer" (from Elanco).

The use of several rounders can also be advantageous. For this purpose, it is proposed that the moist granules be rubbed and compacted in several rounders (rounder cascade) connected in series. The residence time of the moist granules in the rounder is preferably set from 5 to 180 s, in particular from 15 to 80 s. When carrying out the production method according to the invention, a peripheral speed of the rotating base plate of at least 10 m / s, in particular of at least 15 m / s, has also been found to be favorable. Preference is also given to a moisture content of 5 to 20% by weight, in particular 10 to 15% by weight, of the moist granules before rounding.

All substances or mixtures of substances known for this purpose can be used as bleach activators. For the sake of completeness, the substances are summarized as follows: Suitable bleach activators for perver¬ compounds are accordingly O- and / or N-acylated compounds such as pentaacetylglucose (PAG), pentapropionylglucose (PPG), tetraacetylethylenediamine (TAED), tetraacetylglycoluril (TAGU ), Triacetylethanolamine (TAEA), acylated triazine dehvates such as 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), carboxylic anhydrides such as succinic, benzoic or phthalic anhydride, salts of mixed anhydrides, such as sodium or magnesium diacetyl phosphate (NADAP or MGDAP), phenol esters such as p-carboxylphenylacetate, p-sulfonylphenylacetate, and further phenol esters with an anionic substituent on the phenyl radical.

The bleach activator used is preferably tetraacetylethylene diamine (TAED).

A compound from the class of water-soluble cellulose ethers, starch and starch ether is preferably used as the granulation aid in the process according to the invention. Carboxymethyl cellulose, in particular sodium carboxymethyl cellulose, is preferred here. Further information on the granulation aids can be found in DE 30 11 998 C2, to which reference is expressly made here to supplement the disclosure.

During granulation in the mixing granulator, additives such as oxidation-stable complexing agents and stabilizers for per compounds and / or further constituents of detergents and cleaning agents can also be mixed in as granulation aids or introduced via the aqueous granulation liquid. Examples of these are salts of polyphosphonic acids, such as 1-hydroxyethane-1,1-diphosphonate, ethylenediamine tetramethylene phosphonate and diethylene triamine pentamethylene phosphonate, each in the form of the sodium salt. The proportion of the phosphonate additives is preferably 3 to 10% by weight and particularly preferably 5 to 8% by weight, in each case based on the dried bleach activator granules. The preferred amount of phosphonate here is not based on the liquid granulation aid, but rather on the finished product, since it has been found that it is not the phosphonate concentration in the granulation aid, but the absolute amount of the sprayed-on phosphonate that is essential. The advantage lies in the strengthening of the rounding and compacting effect and thus also in an increase in the bulk density of the dried bleach activator granulate. In this case, a universal detergent mixed with the bleach activator granules according to the invention contains about 0.5% by weight of these additives.

In a further advantageous embodiment of the process according to the invention, in the granulating and / or compacting step, as granulating aid, a carboxymethyl cellulose-free solution of a stabilizer for per compounds, in particular a salt of a polyphosphonic acid, and optionally further components of detergents and cleaning agents are used. In particular, it is proposed that the granulation aid contains only polyphosphonate in addition to water.

In the process according to the invention, it is particularly preferred if a finely divided solid (powder) is added to the moist granules moving in the fillet. The powdering in the fillet leads to a better movement of the moist granulate and thus to an improved compaction and rounding.

The powder preferably contains one or more constituents of washing and / or cleaning agents and in particular zeolite NaA.

It is particularly preferred if the powder consists of fine fractions of the finished bleach activator granulate. These fine fractions occur regularly during the screening off of the dried product and are usually returned to the process by adding these fine fractions to the powdery batch used in the first process step, the granulation step. in the In contrast to this process control, the fine particles are thus fed to the second process step according to the invention.

It has proven to be advantageous if 1 to 25% by weight, preferably 3 to 15% by weight, of powder, based on the dried finished bleach activator granules, is added to the moist granules moving in the rounder.

To optimize the fillet and in particular to achieve advantageous surface effects, e.g. B. the formation of a particularly effective barrier against migrating water and / or an increase in the degree of whiteness, the additives mentioned above, in particular an aqueous solution of a granulating aid, or other ingredients of detergents and cleaning agents when rounding the moist granules can be added simultaneously, for. B. be injected.

The water content of the granules is then reduced to less than 3, preferably less than 2 and in particular less than 1.5% by weight. The excess water can be removed by drying with the addition of heat, the temperature of the granules expediently not exceeding 80 ° C. and below the melting temperature of the bleach activator. Dryers that do not disadvantageously change the granular structure of the product are suitable, for example tray dryers, vacuum dryers and, in particular, fluidized bed dryers.

The invention also relates to granules which are stable in storage and contain bleach activators and a granulating aid, prepared by the abovementioned process and which is characterized by a bulk density of at least 580 g / l, in particular at least 630 g / l.

The granules according to the invention have the advantages and surprising effects already mentioned, with the improved whiteness of the granules and the high storage stability of the finished washing and cleaning agent products with these granules being particularly emphasized here. The granules according to the invention are preferably characterized by a content of 70 to 97% by weight, preferably 80 to 95% by weight, of bleach activator, in particular TAED, 0.5 to 10% by weight of a granulation aid, in particular carboxymethyl cellulose and optionally others Components of washing and cleaning agents that are at least as good redispersible as the components mentioned. The possibility of a particularly high bleach activator content is advantageous. In a further advantageous embodiment, the granules according to the invention also contain 0 to 15% by weight, preferably 4 to 8% by weight, of a stabilizer for per compounds, in particular a salt of a polyphosphonic acid.

The granulate according to the invention is further characterized in that it can have a whiteness measured as an L ^* value, determined with the Minolta Chroma-Meter CR color measuring device, of at least 80.

Finally, the subject of the invention also comprises the detergent and cleaning agent end products produced by mixing the granules according to the invention, and in particular products in which the granules containing the main constituents are in the form of uniform, by extruding a homogeneous premix and cutting the obtained strand, that is, have been produced by the above-mentioned extrusion process and to which the granules according to the invention have been mixed.

B e i s p i el e

Exemplary embodiments of the invention are described in more detail below.

example 1

Tetraacetylethylenediamine (TAED) with an average grain size of 0.01 to 0.8 mm was used as the bleach activator. The grain fraction between 0.8 and 1.6 mm was 5% by weight, the fraction below 0.01 mm was 10% by weight.

In a first cylindrical mixer with a vertical axis and a shaft rotating rapidly around this axis with conveying and mixing tools, 1500 kg / h of the powdery bleach activator with 43 kg / h sodium carboxymethyl cellulose (CMC) and 500 kg / h of fine return content were continuously added Grain sizes of less than 0.4 mm mixed and at the same time sprayed with an aqueous 32% sodium diethylenetriamine pentamethylene phosphonate solution (Na / DTPMPA, commercially available product "Dequest / 2066"). The term “fine return fraction” is to be understood as meaning the fine fractions sieved off after drying, which in this example are returned to the first process step. The mixing and uniform distribution took place in an annular layer formed by the tools on the rapidly rotating shaft. Granules were already formed in this mixer.

The product then went through a second cylindrical mixer with a horizontal axis, however, and was brought there into the desired granulate shape.

The resulting wet granulate with a water content of 11.2% by weight was then fed to a rounder cascade consisting of two "Marumerizer" rounders connected in series.

In the cylindrical apparatuses with vertical longitudinal axes, a base plate provided with projections and recesses rotated at a circumferential speed of 18 m / s. Cold air was blown in between the inner wall of the cylindrical housing and the edge of the rotating plate. The granules collected on the edge of the base plate due to the centrifugal force. This very dense ring-shaped rotating granulate layer was caused by the cold air blown in from below into a circular movement around the ring axis in addition to the movement of the ring around the cylinder axis of the apparatus.

After an average residence time of the moist granules in the rounders of 45 s, the granules were discharged and heated in a fluidized bed dryer to a product temperature of 75 ° C. and dried to a residual water content of 0.6% by weight.

The composition of the granules obtained was

85 wt% TAED

7.6% by weight phosphonate

2.55% by weight carboxymethyl cellulose

4.8% by weight of salts and water.

65% by weight of the granules had a grain size of 0.4 to 2.0 mm. The rest contained coarse and very fine fractions, which were screened off and recycled.

The activator granules had a bulk density of 660 g / l. The degree of whiteness L *, determined with the Minolta Chroma-Meter CR color measuring device, was 84, which is a considerably higher value than with the known activator granules, for which it is well below 80.

The activator granules according to the invention were mixed with extrudates prepared in accordance with DE 39 26 253 A1 and containing the main constituents of a universal detergent in order to check the resulting bulk density and the storage stability. This extrudate contained 25% by weight sodium perborate monohydrate. 67% by weight of the extrudate mentioned were mixed with 8.5% by weight of the activator granules according to the invention and with further, conventional detergent components, for. B. enzymes, mixed to the finished detergent end product. For comparison, a mixture was made with granules produced according to DE 30 11 998 C2, which had a bulk density of 530 g / l. Compared to the detergent end product with the known granules, an increase in the bulk density by about 30 g / l was found. From the difference in the bulk weights of the activator granules, namely 130 g / l and their share of 8.5 Theoretically, however,% by weight in the end product results in an increase of only about 10 g / l. This disproportionate increase in the bulk density when using the activator granules according to the invention is surprising.

Both mixes were subjected to a storage test at 60 ° C. The storage test was carried out in a drying cabinet at a relative atmospheric humidity of 15%. Mixing with the known activator granules showed a reduction in the active oxygen content from an initial 1.72% by weight to 1.39% by weight after 8 days of storage. When mixed with the activator granules according to the invention, the content of active oxygen also decreased after an 8-day storage period at 60 ° C. from initially 1.75% by weight to 1.54% by weight. This significantly increased storage stability is a further surprising effect of the activator granules according to the invention and of the detergent end products mixed therewith.

Example 2

In a Schugi mixer (type "Flexomix") 1500 kg / h TAED powder and 800 kg / h fines <0.4 mm, which are constantly returned in the process, were sprayed with 416 kg / h "Dequest 2066" (32 % aqueous solution) granulated. After the moist product had then been passed through a "CB" mixer from Gebr. Lödige, the moist granules were rounded in a rounder cascade consisting of two rounders with a respective disk diameter of 0.7 m at speeds of 300 rpm. The product was dried in a vortex dryer from Haag at product temperatures of 65 - 75 ° C and residual water contents of <1%. The screened finished product had a bulk density of 590 g / l and the following grain composition:

> 1, 6 0.8 - 1, 6 0.4 - 0.8 0.2 - 0.4 <0.2 mm

3.4 33.4 53.9 8.9 0.4%

In a mixture of 8.5% by weight with the extrudates produced according to DE 39 26 253 A1 and containing the main constituents of a universal detergent, bulk densities were 20 g / l higher, based on the finished product, than when using unrounded TAED granules, prepared according to DE 30 11 998 C2. Examples 3a and 3b

In these examples, the granulation was carried out with CMC, but without the addition of phosphonate. At the end of the rounding process, powdering materials were added to the rounder as described below.

Example 3a

Moist granules were produced in batches in the FKM5D mixer from Gebr. Lödige.

Approach: TAED crystalline 1425 g

CMC ('Tylose CR1500P ") 75 g water 225 g

The mixing time with the rotating cutter head was 35 s after adding water. The moist granules obtained were rounded in a rounder with a diameter of the rounding disc of 50 cm at a speed of 450 1 / min for 40 s. After a rounding time of 15 s, 45 g of zeolite NaA ("Wessalith P" from Degussa) were added in the rounder.

Example 3b

The approach and the procedure corresponded to Example 3a, but after 15 s rounding time, instead of zeolite NaA, 150 g of TAED fines <0.4 mm were added to the production plant. After drying and sieving, fine particles of the same order of magnitude were obtained again.

The product data of Examples 3a and 3b after drying with hot air in a fluidized bed to a product temperature of 70 ° C and a residual water content of <1% and a screening of the return proportions> 1, 6 and finer 0.4 mm are listed in the table below. Example> 1, 6 0.8 - 1, 6 0.4 - 0.8 <0.4 Sg ΔSG

3a 0.5 34.8 62.6 2.1 597 20

3b 1, 2 49.1 48.1 1, 6 644 30

Mean

Sg bulk density in g / l

ΔSG bulk density increase in g / l in a mixture of 8.5 wt .-% with the above extrudate compared to the use of non-rounded

TAED granules of the type mentioned above.

The advantages of powdering the moist granules in the filler with powdered bleach activator can be clearly seen in the table.

Claims

claims

1. A process for producing a storage-stable, bleach activator-containing granulate as a component of an agent for textile washing or cleaning agents by granulating a moist powdery mixture of a powdery bleach activator, a powdery granulating aid and an aqueous solution of the same and / or another granulating aid or an aqueous solution of other active substances of detergents or cleaning agents or water by means of agglomerating the moist particles in a mixing granulator and then drying the moist granules and optionally sieving oversize and fine particles, characterized in that before drying the moist granules to the desired residual moisture this feeds another apparatus (fillet) and rubs them against each other and on the wall and / or on the bottom of the fillet and at the same time allows them to be compacted so much that the granules after T rock have a bulk density of at least 580 g / l, in particular at least 630 g / l.

2. The method according to claim 1, characterized in that the moist granules are rubbed and compacted from below between the housing wall and the edge of the base plate in a rounder with a rotating, horizontal base plate while at the same time blowing in a working gas, in particular cold air.

3. The method according to any one of the preceding claims, characterized in that the moist granules are rubbed and compacted in a plurality of rounders which are connected in series.

Method according to one of the preceding claims, characterized by a residence time of the moist granules in the fillet from 5 to 180 s, in particular from 15 to 80 s.

5. The method according to any one of claims 2 to 4, characterized by a peripheral speed of the rotating base plate of at least 10 m / s, in particular of at least 15 m / s.

6. The method according to any one of the preceding claims, characterized by a moisture content of 5 to 20% by weight, in particular 10 to 15% by weight, of the moist granules before rounding.

7. The method according to any one of the preceding claims, characterized in that tetraacetylethylenediamine (TAED) is used as the bleach activator.

8. The method according to any one of the preceding claims, characterized in that the granulation aid used is carboxymethyl cellulose, in particular sodium carboxymethyl cellulose.

9. The method according to any one of the preceding claims, characterized in that a solution of a stabilizer for per compounds, in particular a salt of a polyphosphonic acid and / or a solution of further constituents of detergents and cleaning agents is used as the granulating aid.

10. The method according to the preceding claim, characterized in that the granulation aid contains a proportion of 3 to 10 wt .-%, preferably 5 to 8 wt .-% of the salt of a polyphosphonic acid based on the dried Bleichaktivator¬ granules.

11. The method according to any one of claims 1 to 8, characterized in that in the granulating and / or compacting step as a granulating aid, a carboxymethyl cellulose-free solution of a stabilizer for per compounds, in particular a salt of a polyphosphonic acid, and optionally further constituents of washing and detergents.

12. The method according to the preceding claim, characterized in that the granulation aid contains only polyphosphonate in addition to water.

13. The method according to any one of the preceding claims, characterized in that a finely divided solid (powder) is added to the moist granules moving in the fillet.

14. The method according to the preceding claim, characterized in that the powder contains one or more constituents of washing and / or cleaning agents and in particular zeolite NaA.

15. The method according to claim 13 or 14, characterized in that the powder consists of fine fractions of the finished bleach activator granules.

16. The method according to any one of claims 13 to 15, characterized in that 1 to 25% by weight, preferably 3 to 15% by weight, of powder, based on the dried finished bleach activator granules, the moist granules moving in the fillet admits.

17. Storage-stable granules containing bleach activators and a granulating aid, prepared by the process according to one of the preceding the claims, with a bulk density of at least 580 g / l, in particular at least 630 g / l.

18. Granules according to the preceding claim, characterized by a content of 70 to 97% by weight, preferably 80 to 95% by weight, of bleach activator, in particular TAED, 0.5 to 10% by weight of a granulating aid, in particular carboxymethyl cellulose and, if appropriate, further constituents of washing and cleaning agents which are at least as readily redispersible as the constituents mentioned.

19. Granules according to claim 17, characterized by a content of 70 to 97% by weight, preferably 80 to 95% by weight, of bleach activator, in particular TAED, 0.5 to 10% by weight of a granulating aid, in particular Carboxymethyl cellulose, 0 to 15% by weight, preferably 4 to 8% by weight, of a stabilizer for per compounds, in particular a salt of a polyphosphonic acid and optionally further constituents of detergents and cleaning agents which are at least as well redispersible as the constituents mentioned are.

20. Granules according to one of claims 17 to 19, characterized by a whiteness measured as an L * value according to the Minolta color measurement method of at least 80.

21. 'Washing and cleaning agent containing granules according to one of the

Claims 17 to 20.

22. Detergents and cleaning agents in the form of uniform granules produced by extrusion of a homogeneous premix and cutting the strand obtained, to which granules according to claims 17 to 20 have been added.