EP0075818A2 - Granular bleach activator - Google Patents

Abstract

Granular bleach activator for use in a detergent or bleach, the granules of which are each composed of a) 70 to 99.5% by weight of at least one bleach activator substance for per compounds and b) 0.5 to 30% by weight of at least one water-swellable auxiliary.

Description

The invention relates to granular bleach activators with a certain grain size for use in detergents or bleaches which contain water-swellable substances as auxiliaries, and to a process for the preparation of these activators.

It is known that detergents which contain per-compounds as bleaching agents are only successful with regard to their bleaching action at temperatures close to 100 ° C., because the per-compounds, mostly sodium perborate, do not yet decompose at lower temperatures with sufficient speed to be active in the To be able to intervene in the bleaching process. For this reason, so-called activators have been used for a long time, which reacted with the peroxo group of the per compounds to form peracids, but the latter are already active at 30 to 60 ^b C, ie at temperatures which are necessary for washing delicate textiles.

These activators, which include N- and 0-acyl compounds, such as anhydrides or acid amides, and nitriles - a more detailed list is given below - are highly sensitive to hydrolysis, especially in the presence of alkalis which are common in detergents. This problem is exacerbated by the fact that the activators are often poorly soluble in water, which is why they had to be used in finely pulverized form for faster dispersibility. It is precisely this finely divided form that, due to the enlarged surface area, enables the activators to be hydrolysed during storage.

The most common way to shield bleach activators from moisture is to package them in the form of small particles, preferably coated with an auxiliary. Numerous methods for producing such particles and their use in detergents have been described in the literature.

In the majority of cases, an organic substance or a mixture of organic substances is used as a binding or coating agent, e.g. non-ionic surfactants, fatty acids, polymeric materials or waxes.

From DE-OS 26 57 042 a detergent mixture is known which contains tetraacetylethylenediamine in the form of granulated particles. These particles consist e.g. from said activator and a smaller amount of a nonionic surfactant, which has a melting point of at least 35 ° C.

However, the use of organic substances has the disadvantage that it generally leads to handling problems, especially in the warm season, because of the stickiness, and furthermore the disadvantage that the dissolution or dispersion speed is often slow due to the increased disintegration time of the granules.

Inorganic substances have also already been used for the purpose in question.

For example, GB-PS 1 360 427 teach activator particles which are produced with sodium triphosphate with granulation, and DE-OS 28 55 777 granulated activator particles which consist of a larger proportion of the activator itself and a small proportion of a hydratable salt mixture of sodium triphosphate and another Put the salt together. However, such granules still have insufficient properties. If they are not yet coated, their storage stability (hydrolysis) is unsatisfactory. The coating, on the other hand, limits the rapid dispersibility required in the wash liquor. In particular, the use of water as one of the auxiliary substances and the at least partial remaining water in the activator granulate made it very sensitive to temperature and hydrolysis.

The water bound in the crystal is e.g. released spontaneously when the transition point is exceeded and leads to the decomposition of the activator granules, as described in DE-OS 28 55 777 on page 7. The use of readily water-soluble auxiliaries which have the properties of water-hydration binding is justified with the statement that this is the only way to achieve satisfactory rapid dispersion of the agglomerates under washing conditions.

Water-soluble cellulose ethers, starch and starch ethers are described as pelletizing aids for bleach activators in EP-OS 0 037 026. As in DE-OS 28 55 777, i.a. water used as an auxiliary for granulating. Just as in the first case, a small amount of water that is brought in by the preparation remains in the granulate and immediately destroys part of the stabilization intended by the granulation process.

Every suitable method for assembling a bleach activator has two goals. Firstly, there is an improvement in the hydrolysis stability of the activators, which, regardless of the chemical invidium, all have an easily saponifiable active group which must be protected during storage in alkaline washing powder. On the other hand Any suitable method for protecting the bleach activator from the environment must permit the rapid dispersal of the activator in the wash liquor, ie the release of the activator in the finest distribution must occur within a period of time well before the end of the wash cycle, so that the bleaching effect can be optimal.

The aim of the invention is to use agglomerates composed of <300 μm particles, which have the smallest possible internal surface from which no residual water has to be evaporated, without the use of water and without the use of highly water-soluble, highly hydratable compounds, and despite these parameters, previously known to be prohibitive for good dispersion, they spontaneously disperse finely in the wash liquor and achieve a significantly better storage stability when stored compared to the prior art.

A further goal was a process which was as simple and economical as possible for the production of such granular activators with a coarse particle size which corresponds to that of the other ingredients customary in dry detergents and which is generally 0.5 to 3 mm.

These objectives have been achieved with granular bleach activators of a certain composition and a process for their preparation as defined in claims 1 to 5 and 6, respectively.

The particles generally have a particle size of 0.5 to 3 mm, preferably 0.5 to 2 mm and are composed of 70 to 99.5, preferably 75 to 95% by weight of a bleach activator substance for per compounds and 0.5 to 30 , preferably 2.5 to 15% by weight of at least one auxiliary material which is swellable with water. Preferably contains they additionally 1 to 10, preferably 2.5 to 10 wt.% Of an inorganic or organic builder and / or dispersant; the sum of the percentages must of course be 100 each.

Bleach activators for per compounds are e.g. 0- and N-acylated compounds, such as pentaacetylglucose (PAG), pentapropionylglucose (PPG), tetraacetylethylenediamine (TAED), tetraacetylglycoluril (TAGU), carboxylic acid anhydrides, such as succinic acid, benzoic acid or phthalic acid anhydride, or also salts, such as mixed sodium salts, or also salts Magnesium diacetyl phosphate (NADAP or MGDAP), as well as phenol esters such as p-carboxylphenylacetate, p-sulfonylphenylacetate, p-cresyl acetate or phenyl acetate.

In contrast to the previously used auxiliary substances, the water-swellable auxiliary substance is a substance that does not or only slowly dissolves in water at washing temperatures of at most 70 ° C, but only swellable, i.e. is able to absorb water with a large increase in volume. This clearly shows the function of the additive: the granules, which consist of a mixture of dust-fine microparticles of the activator substance and the additive, are torn apart under the influence of the water - it is therefore not a nonionic surfactant as an emulsifier or a readily soluble additive with high hydration water binding necessary for the dispersion of the particles.

The swellable excipient, because it acts as a "disintegrant", causes immediate dispersion.

Auxiliaries in the sense of the invention are high molecular weight carbohydrates, such as starch, pulverized cellulose, wood pulp, as used in the paper industry or crosslinked polyvinylpyrrolidone (PVP), which is known to be used in the pharmaceutical industry as a tablet disintegrant. It is preferred to use starch or the crosslinked PVP, but also starch ethers such as carboxymethyl cellulose.

The builders and / or dispersants preferably present in the context of the invention are inorganic, such as sodium sulfate, sodium carbonate, then preferably alkali or alkaline earth metal salts of phosphoric acid, oligomeric or polymeric phosphoric acids and organic, such as the alkali metal or alkaline earth metal salts of nitrilotriacetic acid, ethylenediaminetetraacetic acid, Polyacrylic acid, of copolymers of maleic acid with acrylic acid or vinyl ether and carboxymethyl cellulose. The organic acids mentioned can also be used in free form. Nitrilotriacetate, ethylenediamine triacetate, tripolyphosphate, maleic acid-acrylic acid copolymers as sodium salt and carboxymethyl cellulose (CMC) are particularly recommended as dispersants. Mixtures of the substances mentioned can also be used.

According to the invention, CMC can be used both as auxiliary b and as component c, i.e. the bleach activator can contain only CMC in addition to the activator substance. The amount of CMC is then to be measured in such a way that the defined percentages for components a and b are taken into account, i.e. In this case, the bleach activator contains 1.5 to 30% by weight of CMC, preferably 5 to 25% by weight.

The effect of the combination of activator, swellable auxiliaries and optionally builder and / or dispersant is also surprising insofar as the addition of the both acidic and alkaline component c leads to a significant increase in the storage stability of the compact. However, it is clearly evident from other studies that the hydrolysis of the activators is accelerated very strongly under acidic and in particular alkaline conditions.

The combination also results in a compact that is easily dispersed in the wash liquor within a few minutes. The particle size of the dispersed particles is of the same order of magnitude; Surprisingly, the coarse proportion even drops significantly compared to that of the fine powder used in the compaction.

According to the invention, the granular activator is produced by compacting the mixture of the individual components.

The method of pelletizing or constructing granulation fails in this case because there is no binder and no water present, e.g. if the above-mentioned phosphates are used - they are sprayed onto the material to be granulated in aqueous solution - or if starch or cellulose ethers are used.

The granular activator is prepared in detail, for example, in such a way that a homogeneous mixture of the pulverulent auxiliary, the pulverulent activator substance and the pulverulent builder and / or dispersant, in which the activator particles generally have a particle size of approximately 10 to 300 _/ um, manufactured and compacted. The compacting can be carried out in such a way that the aforementioned powder mixture is conveyed into the nip of two rollers rotating against each other by means of a stuffing screw. ⁸ dert and pressed between the rollers. the resulting band ("Schülpe") is broken on a shredder and limited to the desired grain size (advantageously 0.5 to 3 mm) on a sieve shredder.

The material, the particle size of which lies outside the desired limits, is separated off and returned to the compactor together with another mixture to be compacted.

The resulting granular activator is surprisingly very stable in storage, as we have been able to determine, which could not be expected, since the insoluble and only water-swellable auxiliaries do not have any protective functions (coating) against the activator substances in the sense as described in the previous ones Publications should be the case. The storage stability, as we have also found, is in many cases even better, which is shown by the improved bleaching effect of the activators according to the invention which have been stored for a long time compared to activators of the prior art which have been stored for the same time. By adding component c is. to even achieve increased activity.

The following examples and test results explain the invention insofar as the bleach activator is composed exclusively of components a and b.

Examples

• 1) Herstellung des Testwaschpulvers
  • Jeweils 80 Teile eines aus einem Sprühturm kommenden Waschpulvers, dem noch Perborat zugemischt werden muß, werden mit ca. 10 Teilen TAED-Kompaktat = 8 Teile 100 %iges TAED gut gemischt. Die genaue Menge an Kompaktat bestimmt sich aus dem TAED-Gehalt des Kompaktats. Enthält es weniger als 20 Gew.% an Hilfsstoff, wird noch zusätzlich die auf 100 % fehlende Menge Na₂SO₄ zugemischt.
  • Das Testwaschpulver weist folgende Zusammensetzung auf:
    
• 2) Durchführung der Lagerversuche
  • Jeweils 20 bis 30 g der so hergestellten Waschpulvermischung werden in offenen Petrischalen im Klimaschrank bei 38°C und 76 % relativer Luftfeuchtigkeit gelagert. Die Bleichwirkung wird nach-der Abmischung sofort sowie nach 21 und 42 Tagen Lagerung bestimmt.
  • Verglichen wird mit der Bleichwirkung einer Pulvermischung WO die 10 g Na₂SO₄ anstelle des Kompaktats enthält (keine Aktivierung) und mit der gleichen Waschpulvermischung, dem vor jedem Bleichversuch 8 % des kompaktierten Aktivators, bzw. eines Aktivatorgranulats gemäß dem Stand der Technik zugemischt wird.
  • Da das Pulver W₀ ebenfalls der Lagerung unterworfen wird, hat die geringe Zersetzung des Perborats keinen Einfluß auf die relativierten Meßergebnisse, die so weitgehend nur die Hydrolyse des Aktivators angeben.
• 3) Prüfung der Bleichwirkung des Testwaschpulver
  • a) Versuchsbedingungen:
    • Prüfgerät: Launder-Ometer
      Wasserhärte: 16°C
      Flottenmenge: 250 ml
      Flottenverhältnis: 1 : 12,5
      Waschmittelkonzentration: 7 g/l
  • b) Testgewebe:
    • 10 g Baumwollnessel roh (Weißgrad ca. 59 %)
      5 g gebleichter Baumwollnessel mit Rotweinanschmutzung (Weißgrad ca. 70 %)
      5 g gebleichter Baumwollnessel mit Teeanschmutzung (Weißgrad ca. 54 %)
    • Die drei verschiedenen Testgewebe jeweils 30 min gewaschen bei Raumtemperatur, 25 bis 45°C und 35 bis 60°C ergeben nach Weißgradmessung 9 Werte, die aufsummiert werden. Durch diese Summenbildung und durch Doppelbestimmung erreichen die Werte einen ausreichenden Grad an Zuverlässigkeit.
    • Die Weißgrade wurden mit dem ELREPHO-Gerät der Fa. Zeiss mit Filter 8, Xenonlampe mit FL 46 gemessen.
    • Die Differenz der Summen der Weißgrade von W₁₀₀ (s. unten) und W₀, multipliziert mit 100, ergibt die Aktivierung des unzersetzen Aktivators (100 %). Die Differenz der Weißgradsummen von M und M_o, multipliziert mit 100 ergibt die nach der Lagerung verbliebene Aktivität des Pulvers M in Prozent. x

Checking the storage stability of the granular activators

• 1) Preparation of the test washing powder
  • 80 parts each of a washing powder coming from a spray tower, to which perborate is also added must be mixed well with approx. 10 parts TAED compactate = 8 parts 100% TAED. The exact amount of compactate is determined from the TAED content of the compactate. If it contains less than 20% by weight of excipient, the amount of Na ₂ SO _{4 which is} missing to 100% is also added.
  • The test washing powder has the following composition:
    
• 2) Carrying out storage tests
  • In each case 20 to 30 g of the washing powder mixture produced in this way are stored in open petri dishes in a climatic cabinet at 38 ° C. and 76% relative atmospheric humidity. The bleaching effect is determined immediately after mixing and after storage for 21 and 42 days.
  • A comparison is made with the bleaching action of a WO powder mixture which contains 10 g Na ₂ SO ₄ instead of the compact (no activation) and with the same washing powder mixture to which 8% of the compacted activator or an activator granulate according to the prior art is mixed before each bleaching test .
  • Since the powder W _{0 is} also subjected to storage, the low decomposition of the perborate has no influence on the relativized measurement results, which largely only indicate the hydrolysis of the activator.
• 3) Testing the bleaching effect of the test washing powder
  • a) Test conditions:
    • Tester: Launder-Ometer
      Water hardness: 16 ° C
      Amount of liquor: 250 ml
      Fleet ratio: 1: 12.5
      Detergent concentration: 7 g / l
  • b) Test fabric:
    • 10 g raw cotton nettle (whiteness approx. 59%)
      5 g bleached cotton nettle with red wine soiling (whiteness approx. 70%)
      5 g bleached cotton nettle with tea stains (whiteness approx. 54%)
    • The three different test fabrics each washed for 30 minutes at room temperature, 25 to 45 ° C and 35 to 60 ° C give 9 values after whiteness measurement, which are added up. Through this sum formation and through double determination, the values achieve a sufficient degree of reliability.
    • The degrees of whiteness were measured with the ELREPHO device from Zeiss with filter 8, xenon lamp with FL 46.
    • The difference in the sum of the degrees of whiteness of W ₁₀₀ (see below) and W ₀ , multiplied by 100, results in the activation of the undecomposed activator (100%). The difference in the whiteness sums of M and M _o , multiplied by 100, gives the activity of the powder M remaining after storage in percent. x

80 parts of the washing powder coming from the spray tower and 10 parts of sodium perborate were mixed with the respective activator mentioned below in such a way that a content of 8 parts of tetraacetylethylenediamine (TAED) was obtained in the powder. Possibly missing additional quantities were added to 100 parts with Na ₂ S0 ₄ .

• W₀ = Waschpulver ohne Aktivator (nur Na₂SO₄)
• W₁₀₀ Waschpulver + kristalline TAED (8 %) zugesetzt vor jedem Bleichversuch
• W₃ = Waschpulver + 8 % TAED kompaktiert mit 5 % Maisstärke - bezogen auf TAED -, Korngröße 2 mm
• W₄ = Waschpulver M₃, TAED-Kompaktat zusätzlich überzogen mit 4 % 25-fach ethoxyliertem Fettalkohol
• W₅ = Waschpulver M₃, TAED-Kompaktat zusätzlich überzogen mit 8 % 25-fach ethoxyliertem Fettalkohol
• W₆ = Waschpulver + 8 % TAED kompaktiert mit 5 % vernetztem Polyvinylpyrrolidon - bezogen auf TAED
• ''W₇ = Waschpulver + 8% TAED kompaktiert mit 3 % Maisstärke - bezogen auf TAED - Korngröße 0,8-1,5 mm
• W₈ = Waschpulver + 8 % TAED kompaktiert mit 10 % Maisstärke - bezogen auf TAED
• W₉ = Waschpulver + 8 % TAED kompaktiert mit 5 % Hydroxymethylcellulose
• W₁₀ = Waschpulver + 8 % TAED granuliert gemäß DE-OS 28 55 777, Beispiel 1
• W₁₁ = Waschpulver + 8 % kristallines nicht kompaktiertes TAED

Mean it

• W ₀ = washing powder without activator (only Na ₂ SO ₄ )
• W ₁₀₀ washing powder + crystalline TAED (8%) added before each bleaching test
• W ₃ = washing powder + 8% TAED compacted with 5% corn starch - based on TAED -, grain size 2 mm
• W ₄ = washing powder M ₃ , TAED compactate additionally coated with 4% 25-fold ethoxylated fatty alcohol
• W ₅ = washing powder M ₃ , TAED compactate additionally coated with 8% 25-fold ethoxylated fatty alcohol
• W ₆ = washing powder + 8% TAED compacted with 5% cross-linked polyvinylpyrrolidone - based on TAED
• '' W ₇ = washing powder + 8% TAED compacted with 3% corn starch - based on TAED - grain size 0.8-1.5 mm
• W ₈ = washing powder + 8% TAED compacted with 10% corn starch - based on TAED
• W ₉ = washing powder + 8% TAED compacted with 5% hydroxymethyl cellulose
• W ₁₀ = washing powder + 8% TAED granulated according to DE-OS 28 55 777, example 1
• W ₁₁ = washing powder + 8% crystalline non-compacted TAED

The bleaching results are shown in Table I below.

The following examples explain the preferred combination of three from a), b) and c).

• 1. Herstellung des Testwaschpulvers
  • Ein Testwaschpulver wird durch Abmischen eines Turmpulvers mit 10 % Perborat und soviel konfektioniertem Kaltbleichaktivator, daß 8 % Aktivator 100 % im Waschmittel enthalten sind. Mit 33 % Natriumsulfat wird auf 100 % Waschmittelformulierung aufgefüllt. Bei Verwendung von konfektioniertem Kaltbleichaktivatoren wird . das Dispergiermittel gegen die 33 % Natriumsulfat aufgerechnet.
  • Das Testwaschpulver weist nach dem Abmischen folgende Zusammensetzung auf:
    
• 2. Durchführung der Lagerversuche
  • Jeweils 30 g der so hergestellten Waschpulvermischun- ^{gen W} _x werden in offenen Petrischalen im Klimaschrank bei 40°C und 76 % relativer Luftfeuchtigkeit gelagert.
  • Die Bleichwirkung wird nach der Abmischung sofort sowie nach 21, 42 und 84 Tagen Lagerung bestimmt.
  • Verglichen wird mit der Bleichwirkung einer Pulvermischung W₀, die Na₂SO₄ anstelle des Kaltbleichaktivators enthält (keine Aktivierung) und mit der gleichen Waschpulvermischung, der vor jedem Bleichversuch 8 % kristalliner Aktivator frisch zugesetzt wird (W₁₀₀) (Versuch 17 und 18).
  • Da das Pulver W₀ ebenfalls der Lagerung unterworfen wird, hat die geringe Zersetzung des Perborats keinen Einfluß auf die relativierten Meßergebnisse, die so weitgehend nur die Hydrolyse des Aktivators angeben.
• 3. Prüfung der Bleichwirkung des Testwaschpulvers
  • a) Versuchsbedingungen:
    
  • b) Testgewebe:
    • 10 g Baumwollnessel roh (Weißgrad ca. 59 %)
      5 g gebleichter Baumwollnessel mit Rotweinanschmutzung (Weißgrad ca. 70 %)
      5 g gebleichter Baumwollnessel mit Teeanschmutzung (Weißgrad ca. 54 %)

Checking the storage stability of the granular activators

• 1. Preparation of the test washing powder
  • A test washing powder is made by mixing a tower powder with 10% perborate and so much made-up cold bleach activator that 8% activator is 100% contained in the detergent. Make up to 100% detergent with 33% sodium sulfate. When using ready-made cold bleach activators. the dispersant is offset against the 33% sodium sulfate.
  • After mixing, the test washing powder has the following composition:
    
• 2. Carrying out the storage tests
  • 30 g of the washing powder ^{mixtures W} _x thus produced are stored in open petri dishes in a climate controlled cabinet at 40 ° C and 76% relative humidity.
  • The bleaching effect is determined immediately after mixing and after 21, 42 and 84 days of storage.
  • A comparison is made with the bleaching action of a powder mixture W ₀ which contains Na ₂ SO ₄ instead of the cold bleach activator (no activation) and with the same washing powder mixture which 8% crystalline activator is freshly added before each bleaching attempt (W ₁₀₀ ) (experiments 17 and 18) .
  • Since the powder W _{0 is} also subjected to storage, the low decomposition of the perborate has no influence on the relativized measurement results, which largely only indicate the hydrolysis of the activator.
• 3. Testing the bleaching effect of the test washing powder
  • a) Test conditions:
    
  • b) Test fabric:
    • 10 g raw cotton nettle (whiteness approx. 59%)
      5 g bleached cotton nettle with red wine soiling (whiteness approx. 70%)
      5 g bleached cotton nettle with tea stains (whiteness approx. 54%)

The three different test fabrics each washed for 30 minutes at room temperature, 25 to 45 ° C and 35 to 60 ° C result in 9 values after whiteness measurement, which are added up. Through this accumulation and through double determination, the values achieve a sufficient degree of reliability.

The degrees of whiteness were measured with the ELREPHO device from Zeiss with filter 8, xenon lamp with FL 46.

Σ W_x soll dabei die Summe der Weißgrade der Waschmittel- mischung W_x sein, Σ W_o und ΣW₁₀₀ sind die Summen der Weißgrade der beiden vorher beschriebenen Mischungen mit der Aktivierung Null und 100 %.The difference in the sum of the whiteness levels of W ₁₀₀ and W _o corresponds to 100% activation. The activation in% of a mixture is calculated according to the following formula

Σ W _x should be the sum of the degrees of whiteness of the detergent mixture W _x , Σ W _o and ΣW ₁₀₀ are the sums of the degrees of whiteness of the two previously described mixtures with zero and 100% activation.

Example 12

A mixture of 90 parts of tetraacetylethylene diamine (TAED) with a special particle size distribution, 5 parts of corn starch and 5 parts of sodium tripolyphosphate is homogenized in a continuously running Lödige mixer, fed to a roller press by means of a feed screw and compacted into flakes. The scoop is crushed in a hammer mill. Subsequent fractionation leads to a useful fraction with a particle size between 0.5 and 2 mm in diameter. Oversize and undersize granules go back to grinding or compacting.

• 90 Teile TAED
• 5 Teile Maisstärke
• 5 Teile Natriumtripolyphosphat,
  

das zusammen mit Natriumperborat und gegebenenfalls Natriumsulfat einem sogenannten Turmpulver dergestalt zugesetzt wird, daß ein Waschpulver entsteht, das die auf Seite 10 beschriebene Zusammensetzung hat.A granulate of the composition is obtained:

• 90 parts TAED
• 5 parts of cornstarch
• 5 parts of sodium tripolyphosphate,
  

which is added together with sodium perborate and optionally sodium sulfate to a so-called tower powder in such a way that a washing powder is formed which has the composition described on page 10.

Analogous to Example 12, analog compactings were carried out with different amounts of auxiliaries and additives. The product composition is shown in Examples 13 to 25 below (Table II).

The grit granules described in Examples 12 to 25 were then incorporated into a test washing powder in accordance with the test method described and tested for its activating effect. As a result, the washing results were evaluated in the whiteness of the differently soiled fabrics washed at different temperatures. The whiteness which was obtained with a detergent (tower powder + perborate) + TAED, example 28 and PAG, example 29 was evaluated as 100% whiteness. The% activation after storage was calculated according to the formula given above.

Activation values in% based on the initial value (no storage) after 21 days, 42 days and 84 days of storage of the washing powder + activator.

"Important for successful bleaching is the rapid dispersing of the bleach activator in the bleach.

Coarse cold bleach activators have too little surface area, and in unfavorable cases, if they are deposited in the laundry, they can cause fiber damage together with perborate. For all these reasons, the spontaneous dispersion of the agglomerates, be they mixer granules or compactates, in the wash liquor is required.

Since the compacts are produced under high roller pressure, whereas mixer granules are only agglomerated, it was feared that compactates would be significantly inferior to the mixer granules with regard to their dispersion in the wash liquor.

Surprisingly, the compactates described here behave just as favorably as the mixer granules when dispersing. They even have an advantage. The majority of the output activator with a diameter of> 200 µm is still crushed by the compacting, i.e. it is decreasing.

Table IV shows the dispersion times and the particle size distribution of some examples.

Claims (6)

1. Granular bleach activator for use in a washing or bleaching agent, the granules of which have particle sizes of 0.5 to 3 mm and are composed in each case a) 70 to 99.5% by weight of at least one bleach activator substance for per compounds and b) 0.5 to 30% by weight of at least one water-swellable auxiliary,
and which have been produced without the use of water by compacting components a) and b). 2. Granular bleach activator according to claim 1, additionally containing c) 1 to 10% by weight of at least one inorganic or organic builder and / or dispersant compacted in with the proviso that the percentages of a, b and c add up to 100%. 3. bleach activator according to claim 1 or 2, the grains of which are composed of 75 to 95% by weight of the bleach activator substance, 2.5 to 15% by weight of the auxiliary and 2.5 to 10% by weight of the builder and / or dispersant. 4. bleach activator according to claim 1 to 3, wherein the excipient b is crosslinked polyvinylpyrrolidone or a high molecular weight carbohydrate. 5. bleach activator according to claims 1 to 4, in which component c by alkali metal or alkaline earth metal salts of phosphoric acid, oligomeric or polymeric phosphoric acids, alkali metal or alkaline earth metal salts of nitrilotriacetic acid, ethylenediaminetetraacetic acid, polyacrylic acid, maleic acid-acrylic acid or vinyl ether-free copolymers or by organic copolymers Acids themselves as well as by carboxymethyl cellulose is represented. 6. A process for the preparation of granular bleach activators according to claim 1 to 5, characterized in that 70 to 99.5 parts by weight of a bleach activator substance for per compounds with 0.5 to 30 parts by weight of a water-swellable auxiliary and optionally 1 to 10 parts by weight of an inorganic or organic Builders and / or dispersants in powdered form are mixed homogeneously without the use of water as auxiliary, with the proviso that the sum of the parts by weight is 100, the mixture is compacted and the compacted mass is then crushed and the parts with a particle size of 0.5 to 3 mm separates in a conventional manner.