EP0710716B1 - Granulated bleach activators and production thereof - Google Patents

Abstract

Prepn. of a granulate which is stable during storage and consists essentially of a bleach activator and an inorganic binder, comprises the following steps: (A) mixing a dry bleach activator with a dry inorganic binder; (B) compressing the mixt. to form larger agglomerates; and (C) crushing the agglomerates to give the desired particle size.

Description

Bleach activators are important components in compact detergents, Stain removal salts and machine dishwashing detergents. They already enable at 40-60 ° C a bleaching result comparable to that of hot laundry by using Hydrogen peroxide donors (mostly perborates or percarbonates) under Release organic peroxycarboxylic acid react.

The achievable bleaching result is determined by the type and reactivity of the Peroxycarboxylic acid formed, the structure of the bond to be hydrolyzed as well as the water solubility of the bleach activator. Since it's mostly one reactive ester or an amide, it is necessary in many cases for it to use the intended area of application in granulated or coated form, to hydrolysis in the presence of alkaline detergent ingredients prevent and ensure adequate storage stability.

There have been numerous granulations of these substances in the past Auxiliaries and processes have been described. EP-A-0 037 026 describes a Process for the production of easily soluble activator granules Active contents between 90-98 wt .-% described. For this the Powdery bleach activator with powdered cellulose or Starch ethers mixed homogeneously and then with water or a sprayed aqueous solution of the cellulose ether, simultaneously granulated and then dried.

According to EP-A-0 070 474, similar granules can be produced by spray-drying aqueous slurries containing the activator and the cellulose ether. Granules consisting of bleach activator, cellulose ethers and additives of an organic C ₃ -C ₆ carbon or hydroxycarboxylic acid are described in WO 90/01535 and WO 92/13798. While in WO 90/01535 the organic carboxylic acid is incorporated into the granulate core to accelerate its solubility, in WO 92/13798 the carboxylic acid is applied to the finished granulate in an additional coating step. The acidic protective coat is intended to prevent spotting of the bleaching agent and to protect the color of the fabric. For the same purpose, WO 94/03395 claims the use of acidic polymer compounds with a water solubility> 5 g / L (at 20 ° C.) and molecular weights of 1,000 to 250,000.

Also state of the art (GB-A 1 507 312) are granules from Bleach activators, in which mixtures of soaps and free fatty acids as Granulation aids are used.

An anhydrous manufacturing process is known from EP-A-0 075 818. This will the bleach activator together with an organic binder, e.g. one Fatty alcohol ethoxylate, by compacting it into particles with pressure Diameters of 0.5 - 3 mm pressed.

For most of the granulation processes mentioned it is a prerequisite that the granulating bleach activator is a solid and has a high melting point having. This is necessary so that he does not use the binder during manufacture or existing water is reacted and decomposed. For example, in DE-OS-2 048 331 preferred activators that have a melting point of preferably have at least 100 ° C, in particular at least 150 ° C.

So far, mostly organic compounds have been used as binders used. However, this may result in problems related to its use restrict the granules.

Are surface-active compounds used, such as soaps, fatty acids, anionic surfactants or fatty alcohol ethoxylates, so are those produced with them Granules unsuitable for use in machine dishwashing detergents because they are under Washing conditions Foam problems occur. This is even when in use normally low foaming highly ethoxylated fatty alcohols. For this reason, they are predominantly used in dishwasher detergents Activator granules are used, the binder of which consists of cellulose ethers. However, the biodegradability of this product group is moderate.

Suitable granules for use in stain salts pose another problem Modern formulations consist of mixtures of percarbonate and TAED granules. Exothermic decomposition of these mixtures (Percarbonate as a fire-promoting substance in combination with organic material) to prevent production and storage, inert materials are often such as sodium carbonate, hydrogen carbonate or sulfate added. For this Inert binders or coating agents would be of great use Interest.

There is therefore still a need for suitable activator granules that consist of ecologically unproblematic, universally applicable and inexpensive are to be produced.

Inorganic materials as carriers for bleach activators are known per se. In DE-OS-2 733 849, the adsorption of liquid activators, such as Diacetylmethylamine, diacetylbutylamine or acetylcaprolactam, to inorganic Adsorbents such as diatomaceous earth, magnesium aluminum, sodium or Calcium aluminum silicates, activated silica or aluminum oxide, proposed. However, it is not taught how to transform these particles into suitable, storage-stable granules can be transferred.

According to GB-A-2 249 104 particles can also be produced in which a solid bleach activator in finely divided form on inorganic Carrier material is deposited. For this purpose, activator and carrier material first mixed intimately and an organic solvent (ethanol or toluene) added, with the activator going into solution. By subsequent The activator is distilled off in very finely divided form deposited the carrier. The preferred grain size distribution of the Particles of the invention is between 60 and 250 microns. This scripture teaches not, as from the activator-loaded particles, storage-stable granules can be produced.

In addition, EP-A-0 240 057 bleach activator granules are known which by Mixing an activator with inorganic or organic salts, film-forming polymers and small amounts of smectite or aluminum silicates and subsequent granulation in the presence of water. After granulation, an expensive drying stage is necessary to obtain storage-stable granules.

EP-A-0 273 334 describes a process for the preparation of peracid concentrates by compacting granulation of a mixture of peracid and water-soluble Salt.

The Na perborate granules described in WO 91/02696 are also produced by dry pressing of a mixture of Na perborate and an as Receive compacting agent-serving alkali salt, alkaline earth salt or carbohydrate.

US-A-4,695,397 describes bleach activator granules which are used in the absence of Water by pressing a bleach activator with a water-swellable one organic auxiliaries can be obtained.

Surprisingly, it has now been found that storage stability Activator granules that the above Have properties in a simple way Have it produced if bentonite is used as the binding agent and the Pelletizing process anhydrous and without the use of organic solvents or film-forming substances is carried out.

• Vermischen eines trockenen Bleichaktivators mit einem trockenen kristallinen en Schichtsilikat,
• Verpressung dieser Mischung zu größeren Agglomeraten und
• Zerkleinern dieser Agglomerate auf die gewünschte Korngröße.

The present invention relates to a process for producing a storage-stable granulate consisting essentially of bleach activator and a crystalline layered silicate which is characterized by the following process steps:

• Mixing a dry bleach activator with a dry crystalline layered silicate,
• Compression of this mixture into larger agglomerates and
• Crush these agglomerates to the desired grain size.

According to the invention, bleach activators can be those with melting points > 60 ° C can be used. Examples include tetraacetylethylenediamine (TAED), tetraacetylglucoluril (TAGU), diacetyldioxohexahydrotriazine (DADHT),

Acyloxybenzenesulfonates, such as nonanoyloxybenzenesulfonate sodium (NOBS) or Benzoyloxybenzenesulfonate (BOBS) and acylated sugars such as pentaacetylglucose (PAG) or compounds described in EP-A-0 325 100, EP-A-0 492,000 and WO 91/10719.

Further suitable bleach activators are state of the art appropriately activated carboxylic acid esters, carboxylic anhydrides, lactones, Acylals, carboxamides, acyl lactams, acylated ureas and oxamides, in addition, in particular, nitriles. Mixtures of different Bleach activators can also be used.

As crystalline layered silicate binding material come into question natural and / or artificial bentonites, preferably smectite clays from the group of alkali or Alkaline earth montmorillonite, saponite or hectorite with ion exchange capacities of preferably 50-100 meq / 100 g, besides Illite, Attapulgite and Kaolinite. ®Laundrosil DGA and ®Laundrosil EX 0242 from Süd-Chemie, Munich (DE).

Also suitable are crystalline layered silicates, preferably crystalline, layered sodium silicates of the formula NaMSi _x O _{2x + 1} • yH ₂ O, where M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20 and preferred values for x are 2, 3 or 4. Such crystalline layered silicates are described, for example, in European patent application EP-A-0 164 514. Particularly preferred crystalline layered silicates are those in which M is sodium and x is 2 or 3. In particular, both β- and δ-sodium disilicate of the formula Na ₂ Si ₂ O ₅ • yH ₂ O are preferred, wherein β-sodium disilicate can be obtained, for example, by the method described in international patent application WO-A-91/08171 , β-sodium disilicate is commercially available under the name SKS7, δ-sodium disilicate is available under the name SKS6 (commercial products from Hoechst AG, DE). These powders generally have a bulk density of less than 600 g / l and have high fines content, usually more than 30% by weight, with a particle size below 0.1 mm.

Depending on requirements, the aforementioned crystalline layered silicates can be used as Individual substances or as mixtures can be used.

Suitable additives are substances that adjust the pH during storage and Affect applications. These include organic carboxylic acids or their Salts, such as citric acid in anhydrous or hydrated form, glycolic acid, Succinic acid, maleic acid or lactic acid. In addition, additions are possible that influence the bleaching capacity, such as complexing agents, polycarboxylates and Metal complexes containing iron or manganese, as in EP-A-0 458 397 and EP-A-0 458,398.

Also suitable additives are anionic and nonionic surfactants contribute to a faster dissolution of the granules according to the invention.

Preferred anionic surfactants are water-soluble alkali salts of organic sulfates, sulfonates and ether sulfonates with C ₈ -C ₃₁ hydrocarbon radicals, preferably C ₈ -C ₂₂ hydrocarbon radicals. Examples of anionic surfactants are: paraffin sulfonates, alkylbenzenesulfonates, such as sodium and potassium C ₉ -C ₁₈ -alkylbenzenesulfonates, preferably dodecylbenzenesulfonate, C ₁₀ -C ₂₀ alpha-olefin sulfonates, C ₈ -C ₁₈ alkyl sulfates and C ₈ -C ₁₈ alkyl ether.

Preferred nonionic surfactants are fatty alcohol polyalkoxylates, ie C ₈ -C ₃₁ alcohols, preferably C ₈ -C ₂₂ alcohols with 1-15 ethylene oxide and / or propylene oxide units.

Other additives are substances in the wash liquor with those from the activator released peroxycarboxylic acid with formation of reactive intermediates, such as Dioxiranes or oxaziridines react and in this way the reactivity can increase. Corresponding compounds are ketones and sulfonimines corresponding to US-A-3 822 114 and EP-A-0 446 982.

The ratio of bleach activator to crystalline layered silicate is usually 50:50 to 98: 2, preferably 70:30 to 96: 4% by weight on the total weight of the granules. The amount of the additive depends especially according to its type. So acidifying additives and organic Catalysts for increasing the performance of peracid in amounts of 0-20% by weight, especially in amounts of 1-10 wt .-%, based on the Total weight, added, however, metal complexes in concentrations in ppm Area.

To manufacture the granules, a mixing unit (e.g. Ploughshare mixer) the mixture of bleach activator and binder intimately mixed (step a). In a second step, the mixture becomes larger Particles pressed (step b). Suitable for this include Roller compactors. The Pressings are then subjected to comminution (grinding) and crushed to the desired grain size (step c). Suitable for this purpose sprocket rollers and / or strainers.

Fine fraction and coarse material are screened off and returned to the process. While the coarse fraction is directly re-shredded, the fine fraction is added to the compacting stage. The grain size of the product is generally in the range of 100-2000 microns, preferably 300-1800 microns. The bulk density of the granules according to the invention is therefore above 500 kg / m ³ , preferably above 600 kg / m ³ .

The granules obtained in this way can be used directly in washing and Suitable detergents. They can be used in a special way however, be provided with a coating sleeve.

For this purpose, the granulate according to the invention is added in an additional step d) a film-forming substance, which affects the product properties can be significantly influenced.

All film-forming substances, such as waxes, are suitable as coating material. Silicones, fatty acids, soaps, anionic surfactants, nonionic surfactants, cationic surfactants, as well as anionic and cationic polymers, e.g. Polyacrylic.

The aforementioned anionic and nonionic surfactants are preferred used. The preferred cationic surfactants include quaternary alkyl and / or Hydroxyalkylammonium.

By using these coating materials, i.a. the dissolution behavior to be delayed in this way interactions between the Bleach activator and the enzyme system at the beginning of the washing process prevention.

Should the granules according to the invention in dishwasher detergents Waxes with melting points are particularly suitable for this purpose from 40 to 50 ° C.

Acidic coating materials increase the storage stability of the granules in percarbonate-containing, highly alkaline formulations and suppress Color damage due to spotting. Additions of a dye are also possible.

The coating materials are usually applied by spraying the melted or dissolved coating materials in a solvent. According to of the invention, the coating material in amounts of 0-20, preferably from 1-10 wt .-%, based on the total weight, on the inventive Granules are applied.

The products according to the invention are characterized by good storage stability powder detergent, cleaning and disinfectant formulations.

They are ideal for use in heavy-duty detergents, stain salts, Dishwasher detergents, powdered all-purpose cleaners and Denture cleaners.

In these formulations, the granules according to the invention are mostly in Used in combination with a hydrogen peroxide source. Examples of this are Perborate monohydrate, perborate tetrahydrate, percarbonates as well Hydrogen peroxide adducts with urea or amine oxides.

In addition, the formulation can be further according to the prior art Have detergent ingredients, such as organic or inorganic builders and co-builders, surfactants, enzymes, optical brighteners and perfume.

Manufacturing and application examples: Example 1:

In a 50 l Lödige mixer, 12.5 kg of a mixture of 92% by weight Tetraacetylethylenediamine (TAED) and 8% by weight ®Laundrosil DGA (registered Trademark of Süd-Chemie) with a speed of 52 / min 20 min mixed. This mixture is at 38 ° C on a roller compactor with a Pressing force of 40-50 kN pressed into cigar-shaped pillows and then fed to the two-stage grinding. After a pre-meal with Toothed pulley rollers (Alexanderwerk) the product is in a sieve (Frewitt) crushed at a mesh size of 2000 µm. 6.3 kg are obtained Granules with a grain size distribution of 350-1800 µm (yield 50.2%), and 3.6 kg of fines (<350 µm), which are fed into the new compacting process and 2.6 kg of coarse fraction (> 1800 µm), which are fed for renewed grinding become.

Example 2:

The procedure is analogous to Example 1. 12.5 kg of a mixture of 82% by weight of TAED, 8% by weight of ®Laundrosil DGA and 10% by weight of citric acid are used. After compacting (pressing pressure 50-60 kN, maximum temperature 57 ° C) and grinding, the following are obtained:
6.5 kg of granules with a grain size between 350-1800 µm, 4 kg of fine fraction and 2 kg of coarse material.

Example 3:

The procedure is analogous to Example 1, but ®Laundrosil EX 0242 (Süd-Chemie) is used instead of the ®Laundrosil DGA.
Yields: 6.5 kg of granules, 3.8 kg of fines and 2.2 kg of coarse material.

Example 4:

The procedure is analogous to Example 2, but ®Laundrosil EX 0242 (Süd-Chemie) is used instead of the ®Laundrosil DGA.
Yields: 6.4 kg granulate, 3.8 kg fine fraction and 2.1 kg coarse fraction.

Example 5:

Granulat 1: erfindungsgemäßes Granulat nach Beispiel 1

Granulat 2: Vergleichsbeispiel, gemäß EP-A-0 062 523.

6.75 g of standard detergent without bleaching system (WMP detergent, laundry research Krefeld (DE)) and 0.75 g of perborate monohydrate are dissolved in 1 l of distilled water in a beaker at 20 ° C and then 0.3 g of the activator are dissolved added. The following are used as activators:

Granules 1: Granules according to the invention from Example 1

Granules 2: Comparative example, according to EP-A-0 062 523.

Samples are taken at intervals of one minute and the content of peracetic acid formed is determined iodometrically. Time [min] Peracid released [%] Granules 1 Granules 2 1 29 6 3 68 17 5 84 33 7 93 50 8th 100 77

The example makes it clear that the granules according to the invention are better dissolves as the comparison granulate, produced according to EP-A-0 062 523.

Example 6:

a) 2,61 g Bleichaktivatorgranulat (92 %ig) gemäß Beispiel 1

b) 2,93 g Bleichaktivatorgranulat (92 %ig) gemäß Beispiel 3

c) 2,65 g Bleichaktivatorgranulat (90.5 %ig) gemäß EP 062 523.

The bleaching activity of the granules according to the invention is tested under practical conditions in a multi-component washing machine Öko-Lavamat 6753 (AEG, Nuremberg) on bleaching test fabrics in the presence of clean test laundry. According to the dosing instructions for water hardness range 3, 14 g softener (®Skip, Lever Europe) and 70 g basic detergent without bleach (®Skip, Lever Europe) are added to the washing-up compartments of the washing machine. 9.6 g of NaHCO ₃ and 8.0 g of percarbonate as well as

a) 2.61 g of bleach activator granules (92%) according to Example 1

b) 2.93 g of bleach activator granules (92%) according to Example 3

c) 2.65 g bleach activator granules (90.5%) according to EP 062 523.

2 kg of terry cloth are used as fiber, as Test stains 10 bleachable stains (tea, red wine, curry, Grass etc. of the Krefeld laundry research). The laundry is in the Main wash at 40 ° C. The evaluation is done by Determination of the degree of whiteness after washing by adding the Reflectance differences.

Result:

Beispiel 6a: 194 Remissionseinheiten

Beispiel 6b: 192 Remissionseinheiten

Beispiel 6c: 167 Remissionseinheiten.

Total whiteness after washing:

Example 6a: 194 remission units

Example 6b: 192 remission units

Example 6c: 167 remission units.

The example shows that with the granules according to the invention clearly better bleaching results are achieved than with the comparison granulate.

Example 7:

To determine the storage stability, 0.5 g of the TAED granules together with 1.5 g perborate monohydrate and 8 g basic detergent (WMP, Krefeld laundry research) in folding boxes at 38 ° C and 80% humidity stored in a climate cabinet (quick test). At certain intervals the remaining TAED content determined iodometrically.

Granules used:

B1: Granules according to the invention according to Example 1

B2: Granules according to the invention according to Example 2

B3: Comparative example of granules according to EP-A-0 037 026. DAYS Residual TAED [%] B1 B2 B3 2 97 98 98 10 37 79 38 14 27 47 25

The example shows that the granules B1 according to the invention are of the prior art Technology has comparable storage stability, and the invention Granules B2 (with the addition of citric acid) shows an even better stability.

Claims (11)

1. A process for the preparation of storage-stable granules essentially comprising a bleaching activator and a crystalline laminar silicate, which comprises the process steps:

   a) mixing of a dry bleaching activator with a dry crystalline laminar silicate,

   b) pressing of this mixture to give relatively large agglomerates and

   c) comminution of these agglomerates to the desired particle size.
2. The process as claimed in claim 1, wherein naturally occurring or synthetic bentonite, illite, attapulgite or kaolinite is used as the laminar silicate.
3. The process as claimed in claim 2, wherein a smectitic clay selected from the group consisting of alkali metal or alkaline earth metal montmorillonites, saponites and hectorites is used as the laminar silicate.
4. The process as claimed in claim 1, wherein a crystalline, laminar silicate of the formula NaMSi_xO_2x+1·yH₂O, in which M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, is used as the laminar silicate.
5. The process as claimed in one of claims 1 to 4, wherein the process steps a) to c) are carried out in the absence of water and solvent.
6. The process as claimed in one of claims 1 to 5, wherein an N-acylated amine, amide, lactam, activated carboxylic acid ester and/or carboxylic acid anhydride is used as the bleaching agent activator.
7. The process as claimed in one of claims 1 to 6, wherein the ratio of bleaching activator to crystalline laminar silicate is 50:50 to 98:2, preferably 70:30 to 96:4% by weight, based on the weight of the granules.
8. The process as claimed in one of claims 1 to 7, wherein the granules comprise 0 to 20% by weight, based on the total weight, of an additive selected from the group consisting of inorganic acids, organic acids, complexing agents, ketones and metal complexes.
9. The process as claimed in one of claims 1 to 7, wherein the particle size of the granules is in the range 100 - 2000 µm, preferably 300 - 1800 µm.
10. The process as claimed in one of claims 1 to 9, wherein the granules are additionally coated with a coating layer after process step c).
11. The use of the granules prepared as claimed in one of claims 1 to 10 in detergents, cleaning compositions, bleaching compositions and disinfectants.