MXPA97007796A - Procedure for the preparation of a coated granulate of a blank activator - Google Patents

Abstract

Process for the preparation of a granulate coated with a bleach activator, in which a base granulate of the bleach activator is wrapped with a coating substance, and at the same time and / or subsequently

Description

PROCEDURE FOR THE PREPARATION OF A COATED TUBE OF AN # WHITCHING ACTIVATOR Bleach activators are important constituents of washing agents (commonly known as detergents), stain removers and mechanical dishwashing agents. These make possible a whitening effect already at relatively low temperatures, by reacting with '^ (L hydrogen peroxide - most of the time in the form of 0 perborates or percarbonates - the release of an organic peroxycarboxylic acid takes place The result of whitening that can be achieved is determined by the type and reactivity of peroxycarboxylic acid formed, by the structure of the effect perhydrolyzate roasted as the water solubility of the bleach activator. Since most of the time 'fc * is a reactive ester or an amide, in many cases it is necessary to use it in a granulated form for the intended sector of use, in order to avoid hydrolysis in the presence of alkaline constituents of the washing agents and ensure sufficient storage stability. Many coadjuvant substances and a large number of processes have been proposed in the past for the granulation of these substances. In the European patent document EP-A-0 037 026 describes a process for the preparation of an easily soluble activator granulate based on 90 W has + to 98% of an activator with 10 to 2% of a cellulose ether, starch or ether of starch. and disclose in the PCT patent document UO 90/01535 granules having a bleach activator, film-forming polymers and additions of a carboxylic acid, hydroxycarboxylic acid or organic C3-C6 ether carboxylic acid, from EP-A -A- 0.468.824 granules based on a bleach activator and a film-forming polymer are known, which is better soluble at a pH of 10 than at a pH of 7. German patent application publication DE -US-. 39.039 describes a process for the preparation of an activator granulate by mixing a bleach activator in the dry state with an inorganic binder material, which contains water of hydration in the dry state, by pressing this mixture to give agglomerates of larger size and by crushing these agglomerates until the desired grain size is achieved. An anhydrous process for preparing or comparing a bleach activator without the use of water, with at least one adjuvant substance swellable with water, is known from EP-A-0 075 818. It is disadvantageous in these activator granules that the properties of a granulate are essentially established by the binder and by the granulation process used, and frequently, together with the advantages described in the literature, they also have certain properties. disadvantages, p. ex. a non-optimal release of J the active substance, a low resistance to abrasion, a high proportion of dust evolved, an insufficient storage stability, a debonding (segregation) in the powder or a deterioration of the color of the fabric when used in washing and cleaning agents. In order to adjust defined properties in the granules, a coating step is carried out frequently after the granulation stage. The current processes are the coating on mixers 10 (mechanically induced fluidized layer) or the coating on fluidized layer equipment (pneumatically induced fluidized layer). Thus, WO-92/13798 discloses for a bleach activator a coating with an organic acid soluble in water, which melts at temperatures above 30 ° C, and in document UO-94/03305 describes a coating with a water-soluble acid polymer to reduce the deterioration of the * L color of laundry washed. From document UO-94/26862 the coating of a granulate is known., which consists of a bleach activator * and a water and / or alkali-soluble polymer, with an organic compound that melts at temperatures between 30 ° C and 100 ° C, to reduce the segregation in the final product in the form of dust. In such a case, the activator granulate is previously arranged in a plow grinder mixer, it is recirculated without using the shredder at room temperature lfe with 160 to 180 rpm (revolutions per minute) and then sprayed with the dough hot melted A disadvantage of this method is a very poor quality of the coating, which certainly produces a reduction of the segregation in the final product in powder form, but has no influence on the other properties of the granulate, such as p. ex. release of active substances, resistance to abrasion, proportion of dust? detached or storage stability. The positive effect on the segregation behavior must presumably be attributed to a solidification in the form of droplets of the coating substance on the surface of the granulate, whereby the grain of the granulate in the bulk material is crushed. It was the object of the present invention to develop a coating process for granules of activators, which would make possible a deliberate adjustment of the properties of the granules over a wide range, simultaneously with optimum use of the coating material. The resolution of the problem posed by this mission was achieved by an attestation during and / or after the coating operation. The subject of the invention is therefore a process for the preparation of a granulate coated with bleach activator, in which a base product of the bleach activator is wrapped with a coating substance, and at the same time and / or subsequently tempered. As basic granules, all the activators can be used, which in granulated form have a melting point of more than 100 ° C. Examples of activating substances are tetraacetyl-ethylenediamine (TAED), tetraacetyl-glycol-uryl (TA6U), diacetyl-dioxo-hexahydrotriazine (DADHT), acyloxybenzenesulfonates (eg a nonanyloxy-benzenesulfonate k EN0BS3, a benzoyloxy-benzenesuifonate CB0BS3), sugars acylated (eg, pentaacetyl-giucose [PAG]) or compounds as described in EP-A-0,325,100, EP-fi-0,492.00 and UO-91/10719. Other suitable activators are amines acylated in N, amides, lactarines, esters of activated carboxylic acids, anhydrides of carboxylic acids, lactones, acylales, carboxylic acid amides, acyl lactones, acylated ureas and oxides, and together with these compounds especially However, also nitriles, which, together with the nitrile group, may also contain a quaternary ammonium group. They can also be present in the granulate of base blends of different bleach activators. These base products may contain the usual granulation aids, which must have a melting point above 100 ° C. In this case, the film-forming polymers, p. eg: ethers Cellulose, starch, starch ethers, furnace copolymers, copolymers and graft copolymers of carboxylic acids and / or Mk unsaturated sulphonic acids as well as their salts; organic substances, p. eg cellulose, crosslinked poly (vinyl-pyrrolidone) or inorganic substances, e.g. eg: silicic acid, amorphous silicates, zeolites, bentonites, 5-layer alkali silicates having the formula rw'Six 02x -? * and H2O (M, M '= Na, K, H, x = 1.9-23; and -0-25), ortho-, pyro- and polyphosphates, phosphonic acids and their salts, sulfates, carbonates and bicarbonates. Depending on the needs, these agents k. granulation aids can be used as substances individual or co or mixtures. Together with the bleach activator and the granulation aid, the base granules of the bleach activators can also contain other additives which are capable of improving the properties such as, for example, storage stability and the ability to activate bleaching. Among these substances The additives are inorganic acids, organic acids such as, for example, carboxylic acids, hydroxycarboxylic acids and / or univalent ether carboxylic acids or plurivalents, as well as their salts, complexing compounds, metal complexes and ketones. Depending on the needs, the aforementioned additive substances can be used as individual substances or as mixtures thereof. 25 As coating substances come into question all compounds, or mixtures thereof, that are solid to the JÉ | ambient temperature and that soften or melt in the range of 30 ° C to 100 ° C. Examples of these are: C8-C3 fatty acids (eg: lauric, rniristic and stearic acids); C8-C31 fatty alcohols (alkylene glycols) (eg poly (ethylene glycols) with a molar mass of 1,000 to 50,000 g / mol); nonionic compounds (eg polyalkoxylated fatty alcohols Cs ~ C3i with 1 to 100 moles OE (= ethylene oxide)); anionic compounds (eg f-alkanesulfonates, alkylbenzenesulfonates, α-olefin sulfonates, alkyl sulfates, alkyl ethersulfates with C8-C31 hydrocarbon radicals); polymers (eg polyvinyl alcohols) waxes eg: ontanic waxes, paraffin waxes, waxes esters, polyolefin waxes); silicones. In the coating substance, which softens or melts in the range from 30 to 100 ° C, other substances which do not soften or melt in this temperature range, for example, can be dissolved or suspended. eg polymers (eg homopolymers, copolymers, or graft copolymers of carboxylic acids and / or unsaturated sulfonic acids as well as their alkali metal salts, cellulose ethers, starches, starch ethers, poly (vinylpyrrolidone) ), - organic substances (eg carboxylic acids, hydroxy carboxylic acids or ether carboxylic acids, univalent or plurivalent, with 3 to 8 C atoms, as well as their salts); colorants; inorganic substances (eg, silicates, carbonates, bicarbonates, sulphates, JES phosphates, fo or cough). Depending on the desired properties of the coated granulate of the activator, the content of wrapping substances may be up to 1 to 30% by weight, preferably to 5 to 15% by weight, based on the granulate coated with activator. For the application of the substances of wrapping can be used mixers (with fluidized lid induced * 4 § - mechanically) and fluidized layer devices (with pneumatically induced fluidized layer 0). As mixers are possible p. ex. plow grid mixers (operating in continuous and discontinuous regimes), annular layer mixers and also Schugi mixers .. The feeding can be carried out, if a mixer is used, within a preheater of the granulates and / or inside the mixer directly and / or in the fluidized bed disposed behind the b mixer. For the cooling of the coated granulate, granular coolants and / or fluidized bed coolants can be used. In the case of equipment with fluidized layer, the operation is carried out through the hot gas used to produce the swirling. The granulate coated according to the fluidized layer process can be cooled in the same way as it is carried out in the blender process through a granular coolant and / or a fluidized bed coolant. Both in the case of a mixer process and also in a fluidized layer process, # in the coating substance can be applied by spraying or spraying through a nozzle device for a single substance or for two substances. The heat treatment consists of a heat treatment at a temperature of 30 to 100 ° C, but precisely or below the melting or softening temperature of the respective wrapping substance. Preferably, work is carried out at a temperature that is only slightly below the • ^ f melting or softening temperature. The grain size of the coated bleach activator granulate is 0.1 to 2.0 nm, preferably 0.2 to 1.0 rpm and particularly preferably 0.3 to 0.8 nm. The exact temperature during tempering, or the temperature difference with respect to the melting point of the coating substance, is dependent on the coating amount, the holding time and the desired properties for the coated granulate of bleach activator. and must be determined in previous experiments 0 for the respective system. The duration of the aging time is from about 1 to 180, preferably from 3 to 60, particularly preferably from 5 to 30 minutes. The advantage of the new process compared to state 5 of the technique lies in the fact that the liquid coating agent does not solidify too quickly and therefore has the possibility of running in a thin peel form on the surface of the granulate. . In this way, a very uniform coverage of the grain in a thin layer with the coating substance and an optimum coating effect is achieved, at the same time that a minimum amount of the coating substance is used. In the case of the usual procedures, that is to say without stage of atemperara! On the other hand, there is a too rapid solidification of the individual droplets on the cold surface of the granulate. As a consequence, the surface is covered only with fine individual droplets and still has large areas in which the coating is missing. The desired coating effect is thus only insufficiently achieved or a significantly larger amount of coating substance is needed to achieve a desired coating effect. The latter, however, reduces the content of the activating substance, which in many cases is not desired. By means of the process according to the invention, the properties of the activator granules can be optimally optimized, within wide limits, by deliberately aiming at the desired requirements by appropriately choosing the coating substance, the coating quantity and the temperature profile of the process. In such a case, the deliberate optimization of the following 5 properties of the activator granules is possible above all.

Jtk 1. Time-optimized release of the active substances To avoid the interaction between the bleaching system and the enzymatic system, a reaction 5 and a release, slightly delayed in time, of the active ingredients of the bleaching system are advantageous, simultaneously with a faster effect of enzymes. In this way, the enzymes can fully develop their washing force in the first minutes of the washing process, without being damaged by the bleaching system. Only after the enzymes have developed their work, the bleaching process is then started by reacting the bleach activator with the source of hydrogen peroxide. By appropriate coating of the bleach activator, the reactivity, ie the speed of dissolution, or the rate of peracid formation, can be deliberately adapted to the enzymatic system. In the jk < In this process, a deliberate adjustment of the rate of formation of peracids with a simultaneously minimal amount of the coating substance is possible and therefore a maximum content of the activator. • 2. Increased resistance to abrasion By coating a granulate with substances that soften or melt, you can increase the resistance to the abrasion of an activator granulate. In such a case, the increase in the abrasion resistance is the greater the better the surface of the granulate is coated with the coating substance. By means of the coating process according to the invention, a rapid displacement of the coating substance on the surface of the granulate and thus an optimum improvement of the abrasion resistance can occur. 3. Reduction of the proportion of dust released By the coating process according to the invention, in which, by appropriate tempering during and / or after the wrapping stage, too rapid solidification of the coating substance which softens or melts is avoided, it is also possible an optimum elimination of the powder having a granulate with a greater amount of coating, since the coating substance remains able to flow and agglutinate for a long period of time and therefore is in a position to fix a greater quantity of particles of dust. In the case of the coating according to the state of the art, on the contrary, an unfavorable event must be counted even with an increase in the proportion of dust evolved as a consequence of a partially direct spray drying. 4. Increase in storage stability When storing a washing and cleaning agent, a reaction with subsequent loss of active oxygen can be reached, at the boundary between a grain of the activator and a grain? Tt directly adjacent to the source of hydrogen peroxide. and consequently to an uncontrolled degradation of the bleaching system. By means of an optimum coating, such as is possible only by the coating process according to the invention, a complete protective layer is formed at the boundary of the grains which then represses a reaction in-the grain of the activator and the grain of the source of Mt hydrogen peroxide during storage. In the case of 0 using water-soluble and / or melting substances which melt at low temperature, the necessary bleaching performance in the washing process can still be achieved. The granules obtained in this way are directly suitable for use in washing and cleaning agents. They are ideal for use in complete washing agents, stain removers, mechanical dishwashing agents, all-purpose powder cleaners, and denture cleaners. In these formulations, the granulates according to the invention are used at least part of the times in combination with a source of hydrogen peroxide. Examples of this are a perborate-rnonohydrate, a perborate-tetrahydrate, percarbonates as well as adducts of hydrogen peroxide with urea and amine oxides. In addition, the formulation corresponding to the state of the art 5 can have other constituents of washing agents, such as detergency builders and co-agents, organic or inorganic detergency builders, agents * surfactants, enzymes, washing additives, optical aolaradores and perfumes. EXAMPLES 5 EXAMPLE 1 Coating in a Schugi fluidized bed mixer set up below for tempering and cooling * 0 TAED 4303 (Hoechst AG) was dosed continuously with a flow rate of 480 l < g / h in a Schugi mixer (Flexornix 160, entity Hosokawa Schugi) and sprinkled with a melt of myristic acid, hot at 75 ° C. The coated material fell directly into a fluidized bed connected thereafter (Hosoka to Schugi) and there it was tempered in a first chamber for 5 to 10 minutes at a fluidized bed temperature of about 54 ° C and then cooled in a second chamber. chamber at fluidized bed temperatures of 0 about 35 ° C. For comparative purposes (state of the art), TPED 4303 was dosed continuously with a flow rate of 480 / h in the Schugi mixer, it was sprayed with a melt of myristic acid, hot at 75 ° C, and then cooled directly in the fluidized bed connected below, at fluidized bed temperatures of about 35 ° C. The quality of the coating of the products was evaluated by determining the rate of formation of the peracetic acid at a temperature of 20 ° C. The slower the formation of peracetic acid, the better the degree of coating achieved. To determine the rate of peracetic acid formation, 1 1 of distilled water, 8.0 g of the washing agent for UMP and 1.5 test were placed in a wide-mouthed glass of 2 1 capacity. g of sodium perborate rnonohydrate at 20 ° C, and stirred with a magnetic stirrer at 250 to 280 rprn. After 1 to 2 rrun, 0.5 g of the TAED coated granulate was then added. After one minute, an aliquot portion of 50 rnl was pipetted and poured into an Erlenmeyer flask over 150 g of ice and 5 rnl of 20% acetic acid. After adding 2 to 3 rnl 5 of a 10% solution of potassium iodide, it was quickly evaluated with a 0.01 molar solution of sodium thiosulfate, until reaching the point of potenciorneric equivalence (Titroprozessor 716 DMS, Metrohm entity) ) and from the amount consumed of sodium thiosulfate the amount of peracetic acid was calculated. At intervals of 2 to 5 rnm, samples were then taken and evaluated as described. The total process was repeated as many times as they were necessary until after three consecutive titrations equal or even decreasing amounts of peracetic acid were found. The maximum amount found of the peracetic acid was then established as 100% and on this basis the peracetic acid amounts formed after 5, 10 and 20 minutes were finally determined as a percentage, as measured for the rate of peracetic acid formation. Table 1: Formation rate of peracetic acid present in the TAED granules (Products 1 and 4, Comparative Examples) coated in the Schugi mixer. with fluidized bed arranged below. No. of the TAED granulate Peracetic acid formed T.% 1 Product 5 rnin 10 min 20 rnin Base granulate (BG, uncoated) 75 95 100 2 BG + 10% myristic acid, tempered 11 21 55 3 BG + 15% myristic acid, tempered 9 18 54 4 BG + 15% myristic acid, cooled 39 59 83 By means of the aging, the quality of the coating, expressed by the delay in the formation of peracetic acid can be clearly improved, in comparison with the quantity of the coating (comparison of the products 3 and 4). To achieve an optimum coating quality, an amount of 10% of the coating substance (Product 2) is sufficient, with suitable tempering.

EXAMPLE 2 * Coating according to the fluidized layer process with adhesion made below 500 - 600 g of TAED 4303 were placed in the fluidized layer (fluidized layer equipment Strea 1, entity Aeronatic) and were sprayed with a molten loop of stearic acid, heated at approximately 80 ° C in such a context, in one case, for comparative purposes, the fluidized bed was operated at low temperatures and after the application had been completed. sprayed, cooled again approximately 5 rnin (state of the art). In the other case, according to the process according to the invention, the coated granulate was previously placed back into the fluidized layer and was tempered. For this, the fluidized bed was heated stepwise at temperatures of about 65 to 70 ° C - and this temperature of the product was kept constant for about 5 to 8 min. Then, the tempered product was again cooled stepwise. The quality of the coating was checked again by determining the rate of formation of the peracetic acid at a temperature of 20 ° C. The slower the formation of peracetic acid, the better the degree of coating achieved.

TABLE 2 # Formation rate of peracetic acid that "present the TAEI granules) (Products 5, 8 hasH to 10: K Comparative examples) coated in the fluidized layer process with subsequent sequencing NO of the TAED granulate Peracetic acid formed Í% 1 product 5 rnin 10 inin 20 in * 5 Base granulate (BG) 75 95 100 6 BG + 10% stearic acid, tempered 10 21 50 7 BG + 20% stearic acid, tempered 12 22 52 8 BG * • 10% stearic acid, without tempering 70 85 98"^ 9 BG + 20% stearic acid, without tempering 40 60 84 10 BG + 30% stearic acid, unattached 20 35 60 Through the addition, with the same amount of coating, the quality of the coating can be clearly improved. coating, expressed by the delay of peracetic acid formation (comparison of Products 6 and, 8 and respectively of Products 7 and 9).

To achieve an optimum quality of the coating, an amount of 10% coating substance is sufficient (Product 6). The influence of weathering on the quality of the coating is also demonstrated in the storage stability of TRED granules in washing agent formulations. The storage stability check ßm was carried out in prefabricated folded boxes (height 6.5 crn; width 3.2 crn; depth 2.2 crn) at 38 ° C and a relative humidity of air (rF) of 80%, during a period of time of 28 days. Each of the folded boxes was filled with a homogeneous mixture based on 8.0 g of UMP test washing agent, 1.5 g of sodium percarbonate and 0.5 g of the granulate of TAED to test and then closed at the top with Tesaflirn tape. All samples were mixed and packed on the same day. The folded boxes filled and labeled were then fitted in a * HVAC cabinet at a sufficient distance between them and stored at 38 ° C and an RF of 80%. After a while After storage of 0, 3, 6, 9, 15, 23 and 28 days, the samples were taken out of the air conditioning cabinet, all the samples were incorporated at 20 ° C in 1 1 of distilled water with agitation by means of a stirrer magnetic (at 250 to 280 rmp) and 1 g of sodium percarbonate was added. the determination Further, the amount of peracetic acid formed was carried out analogously to the data given in Example 1. From the maximum found value of the peracetic acid, the TAED content of the sample was then calculated. The degree of conservation of the TAED constitutes the percentage content of TAED of the sample after storage, referred to the content in TAED of the sample not stored.

TABLE 3 Storage stability in formulations of TAED granulate washing agents coated in the fluidized layer process with subsequent temperature adjustment.

NQ of the TAED Granulate Degree of conservation of TAED product after storage C% 3 Od 3d 6d 9d 15d 23d 28d # Granulate 100 24 14 12 10 base (BG) 20 BG + 10% acid 100 88 61 56 56 45 45 ethereal, tempered BG + 20% acid 100 52 24 20 18 16 15 stearic, un-tempered With small amounts of the coating, from 5 to 10%, an improvement of many properties of the product can be achieved, among them for example the storage stability in formulations of washing agents, only by tempering, that is to say only by the process according to the invention.

EXAMPLE 3 Coating according to the fluidized layer process with simultaneous tempering # 10 TAED 4303 was metered in, through a flexible dosing auger, in a continuous mode with a quantity of 40 kg / h, in a fluidized layer apparatus (layer technical equipment) fluidized) and coated with 20% rniristic acid. The residence time in the fluidized layer was about 30 minutes. The product discharged through a cellular wheel gate (compartments) ^ It was transported by a dosing screw to a screening machine, in which the coarse portion greater than 1.0 nm and the fine portion greater than 0.2 nm were separated. The The coarse portion was then comminuted in a mill and then, in common with the fine portion, returned to the fluidized layer equipment through a metering auger. In the course of the experiment, the temperature of the fluidized bed was increased from 46 ° C at the beginning to 54 ° C at the end. 25 The quality of the coating was checked by determining the rate of formation of peracetic acid. "> at a temperature of 20 ° C as well as the proportion of the loose dust that is less than 0.2 rnrn of the coated TAED granulate. The slower the formation of peracetic acid, the better is the degree of coating achieved. The lower the proportion of dust evolved, the better the dust removal achieved by the coating, and the increase in abrasion resistance. 1 00 TABLE 4 Formation rate of peracetic acid of TAED granules (Product 11: Comparative example) coated according to the simultaneous fluidized layer method 15 tempering ? NQ of the Acid-treated Granulate Proportion of TRED? EracéticoH% 3 of dust L ~ ° C3 5 rnin 10 rnin 20 min C% 3 11 Granulate of - 75 95 100 base (BG) 12 BG + 20% of 46 66 81 94 30 ini ristic acid 13 BG + 20% of 49 48 68 87 15 myristic acid 14 BG + 20% of 52 38 60 86 10 myristic acid 15 BG + 20% of 54 20 36 62 no ristic acid With increasing temperature of the fluidized bed, which approaches the melting point of myristic acid (55 ° C), the quality of the coating clearly increases, expressed by the delay in the formation of the peracid and a better dust removal is achieved and a greater abrasion resistance, expressed by the decreasing proportion of dust, < 0.2 rn, of the coated granulate.

EXAMPLE 4 Coating in the plowshare mixer with simultaneous "V tempering W 5 1.2 kg of the TAED granulate according to EP-A-0.03 .026 was previously arranged in a batch-plow discontinuous mixer (M5R, entity Lódige) and, through good thorough mixing with a number of revolutions of mixing tools of approximately 150 rprn, was sprayed with 210 g of a melt of stearic acid, hot at 80 ° C. In such a case, the contents of the mixer during the coating step were tempered through a heating jacket at a temperature of 50 ° C. The time of coating and tempering was approximately 10 minutes. With comparative purposes, they set out * previously, in a batch plow discontinuous mixer according to UO-94/26826, 1.2 kg of the TAED granulate according to EP-A ~ 0.037.026 and sprayed at the temperature environment with 210 g of a melt of stearic acid, hot at 80 ° C, by thorough mixing with a number of revolutions of the mixing tools of approximately 150 rprn. The quality of the coating was checked by determination of the rate of formation of peracetic acid at a temperature of 20 ° C.

TABLE 5 Rate of peracetic acid formation present in the TAED granules (Products 16 and 18, Comparative Examples) coated in the plowing grate mixer with abatement during the coating stage NQ of TAED granulate Peracetic acid L ~% 3 product 5 min 10 min 20 rnin 16 Base granulate 81 9d 100 17 BG + 15% stearic acid, tempered (at 50 ° C) 44 61 79 18 BG + 15% acid 75 90 98 stearic, without tempering Without delay, a positive effect can certainly be achieved by the coating on the The behavior of segregation in the powder (Product 18), but the improvement of many other properties, among them, for example, the delay in the formation of peracetic acid, is possible only by angling, that is to say by the process according to the invention (Product 17). ). The positive effect on the debonding behavior, which is achieved by the coating without abatement, must presumably be attributed to the solidification in the form of droplets of the coating substance on the surface of the granulate, whereby a crumbling of the Grain grain in the bulk material. However, no positive effect on many other properties is linked with it.

EXAMPLE 5 Coating in the plowshare mixer with simultaneous tempering The TAED 4303 was continuously incorporated in a continuous manner with flow rates of 100 to 300 kg / h in the plowshare mixer (KT-160, entity Drais). In this case, the contents of the mixer were alternated through a heating jacket at a temperature in the range of 44 to 52 ° C. The residence time in the mixer was from 8 to 12 minutes. Simultaneously a molten mass of stearic acid was injected at a temperature of 80 ° C in the front of the mixer (closer to the inlet for the product). The amount of coating was 7%. The mixer was operated at a rotational speed of the 90 rpm mixing tools and without using the demolding knife. The degree of loading in the mixer was adjusted so that the product covered precisely the mixing shaft. The coated material was removed continuously from the mixer and was conducted directly through a * sieve (0.2 to 1.0 rnrn) in order to separate the thin and thick portions. The quality of the coating was checked by determining the rate of formation of the peracetic acid at a temperature of 20 ° C.

TABLE 6"f Coating of peracetic acid formation having 0 TAED granules (Pr-oduct 19: comparative example) recorded in the plowing-bed mixer with simultaneous addition of the granulate Tmezcia peracetic acid C% 1 product of TAED C ° C3 5 rnin 10 in 20 inin 5 19 Base granulate 75 95 100 20 BG + 7% acid 44 72 95 99 stearic 21 BG + 7% acid 48 70 90 98 0 stearic 22 BG + 7% acid 52 60 80 94 stearic With increasing temperature of the mixing product, which approaches the melting point of stearic acid, the coating quality increases, expressed by the. delay in the formation of peracetic acid.

Claims (1)

1. NOVELTY OF THE INVENTION CLAIMS 1. - Procedure for the preparation of a granulate 5 of coated bleach activator, characterized in that a base granulate of the bleach activator is wrapped with a coating substance and at the same time and / or subsequently tempered. "^ 2.- Procedure according to claim 1, 10 characterized in that the base granulate of the activator has a melting point higher than 100 ° C. 3. Method according to claim 1 or 2, characterized in that the coating substance has a softening or melting point in the range of 30 to 15 100 ° C. 4. Method according to one or more of claims 1 to 3, characterized in that the aging takes place during and / or after the coating step at temperatures close to the softening or melting point. 20 of the coating substance. 5. Process according to one or more of claims 1 to 4, characterized in that, as activators of bleaching, N-amines acylated, amides, lactarines, acyloxy-benzenesulphonates, acylated sugars, activated carboxylic acid esters, carboxylic acid anhydrides are used. , lactones, acylals, oxarnides and / or nitriles that # may contain- a quaternary ammonium group. 6. Process according to one or more of claims 1 to 5, characterized in that fatty acids, fatty alcohols, poly (alkylene glycols), nonionic surfactants, ammonium surfactants, polymers, waxes and / or waxes are used as coating substances. or silicones. 7. Process according to one or more of claims 1 to 6, characterized in that the substance of the coating contains polymers, organic substances and / or inorganic substances, in dissolved or suspended form. 8. Process according to one or more of claims 1 to 7, characterized in that the content of coating substance is from 1 to 30% by weight, preferably from 5 to 15% by weight, based on the coated activator granulate. 9. Method according to one or more of claims 1 to 8, characterized in that the application of the coating substance is carried out in a mixer or in an apparatus with a fluidized layer. 10. Process according to one or more of claims 1 to 9, characterized in that the grain size of the coated bleach activator granulate is 0. 1 to 2.0 nm, preferably 0.2 to 1.0 m and especially preferred mode 0.3 to 0.8 nm. 11. Method according to one or more of claims 1 to 10, characterized in that the base granulate of the activator contains up to 20% by weight, based on the weight of the activator base granules, of one or more additives, selected from the group consisting of group consisting of inorganic acids, organic acids, form complex compounds, ketones and metal complexes. 12. Granules coated with a bleach activator, prepared according to the. procedure according to one or several of claims 1 to Ll. 13. Washing, cleaning, bleaching and disinfecting agents, containing a coated bleach activator granulate, prepared according to the method according to one or more of claims 1 to 11. #