DE3348394C2 - Sodium percarbonate bleaching agents - Google Patents

Abstract

Bleaching agents contg. Na percarbonate (I) coated with a borate-contg. compsn. (II) are claimed. Also claimed are bleaching detergent compsns. contg. 1-99wt.% of (I) coated with (II).(II) may contain 10-100wt.% borate, esp. Na metaborate, opt.together with a sequestering agent (esp. EDTA or NTA) and/or an alkali metal silicate or a Mg cpd. The amt. of (II) may be 0.1-30% of the wt.of (I).Coating (I) with (II) stabilises it against decompsn., esp. in detergent compsns. which have a low or zero phosphate content and/or contain aluminosilicates

Description

The invention relates to a storage-stable sodium percarbonate and a method for its production.

Sodium percarbonate is as a bleaching agent or oxidizing agent known. Like sodium perborate, sodium percarbonate is also included Oxygen-eliminating bleach. Sodium percarbonate will prepared by reaction of sodium carbonate with hydrogen peroxide to a compound of general formula 2Na₂CO₃ · 3H₂O₂.

Sodium percarbonate has a lower bleaching power than a Chlorine-containing bleach at ambient temperature. Therefore The use of sodium percarbonate has the advantage of being synthetic fibers, animal fibers, plastic-treated Fibers or fibers treated with optical brighteners turns yellow and does not attack the fibers. In addition, it shows a sufficient bleaching effect at elevated temperature or in Presence of a decomposition accelerator. sodium is therefore used as household or as technical bleach used.

Sodium carbonate is in the range of detergents and in the field household bleach of particular importance, since its Decomposition products do not lead to pollution, therefore it is usable without problems.  

However, sodium percarbonate shows the undesirable disadvantage that its storage stability is significantly worse than that of Sodium perborate and that provided oxygen lost very quickly during storage. The surface of the Sodium percarbonate becomes moist, and it gets lower even Humidity quickly decomposes, as it has a high affinity for Has water. Especially if iron, copper, manganese or cobalt ions are present, the decomposition still continues accelerated, and the stability is then still significant less than that of sodium perborate. Only if sodium percarbonate stored alone in a closed vessel is the storage stability corresponds approximately to that of the sodium perborate. However, if sodium percarbonate in the form of a mixture stored with detergents or in open containers, Due to its high solubility, it has a high moisture sensitivity and low storage stability.

Sodium tripolyphosphate (STPP), which is used in detergents as a builder contained, leads to eutrophication and thus causes Pollution in closed water areas. It exists therefore, a need for low phosphorus detergents or those without phosphorus. Recently, therefore as replacement for STPP synthetic zeolites (aluminosilicates) used.

However, sodium percarbonate is in the zeolite-containing detergents completely unstable. In the zeolite-containing phosphorus-free Detergents or cleaning agents increases the proportion of the Sodium percarbonate provided oxygen very much fast due to the catalytic decomposition by the aluminosilicates from.

It has been proposed to stabilize sodium percarbonate thereby by mixing it with paraffin or polyethylene glycol a molecular weight of 3000 to 8000 mixes. These known However, methods are practically not usable, since the water solubility  of sodium percarbonate in this way very strong is reduced or the substance thereby practically insoluble and in addition to the use of polyethylene glycol beyond no higher storage stability is achieved because the polyethylene glycol in itself hygroscopic.

Furthermore, a method has been proposed in which at least two stabilizers selected from the group consisting from phosphoric acid compounds, silicic acid compounds, Ethylenediaminetetraacetaten and nitrilotriacetates in the aqueous Hydrogen peroxide solution in the preparation of sodium percarbonate be incorporated. However, these stabilizers cause no practical stabilization when using water or Detergents are mixed.

In another known method, sodium percarbonate is used uniformly coated with sodium pyrophosphate, this Method has the disadvantage that the stabilizing effect not reached in the presence of moisture and detergents and also the thermal decomposition rate is low.

From DE-OS 28 00 916 is a method for producing a Sodium percarbonate-containing bleach known, the Sodium percarbonate comprising compounds of boric acid Group is coated. In an advantageous embodiment is the shell material in an amount of 0.5 to 20%, based on the weight of the peroxide compound, used and generally consists of 30 to 100% of the boron compound, boric acid being used as boron compound.

From US-A-3 951 838 a sodium percarbonate with improved Storage stability in solid bleach detergents described wherein the sodium percarbonate particles are mixed with an aqueous sol, containing silica gel, coated and then dried become.  

From DE-A-27 12 139 are sodium percarbonate layer particles known, consisting of a sodium percarbonate core and a serving consist of sodium perborate and sodium silicate.

From DE-A-24 58 326 a mixture is known, which is substantially from sodium percarbonate particles, these being evenly with a film of a hydrophobic liquid organic Compound coated with sodium perborate are included.

US-A-4 120 812 discloses a coated peroxy compound having improved storage stability, wherein the peroxygen compounds with a polyethylene glycol product are coated.

DE-A-26 51 442 describes sodium percarbonate layer particles, those made from a sodium percarbonate core and a serving Sodium perborate exist, with a highly dehydrated sodium perborate is used, since this the adhesive strength Sodium percarbonate is improved.

From DE-A-28 10 379 a process for the preparation of stabilized sodium percarbonate, in which a sodium perborate layer is applied to the sodium percarbonate core.

The invention is based on the object, a storage-stable Sodium percarbonate to create, especially then a has sufficient storage stability when the sodium percarbonate in a detergent with low phosphorus content or no phosphorus content or an aluminosilicate cleaning agent is used, as well as to provide a method for its production.

This object is achieved by a storage-stable specified in claim 1 Sodium percarbonate and by the specified in claim 9 Procedure solved.

The dependent claims describe advantageous embodiments of Process.  

The invention therefore relates to a process for the preparation of storage stable sodium percarbonate obtainable therefrom is that on the surface of sodium percarbonate one Apply sodium borate-containing layer, with water present is, and then the product at a temperature of not higher than 160 ° C dries.

The following

Fig. 1 shows an electron micrograph of an uncoated sodium percarbonate particle, and

Fig. 2 shows an electron micrograph of the coated sodium percarbonate particle in each case in a 100-fold magnification.

FIG. 3 shows a 440-fold enlarged view of a cross-section of the coated sodium percarbonate particle according to FIG. 2, wherein the borate-containing coating layer is clearly visible on the surface of the particle. The sodium percarbonate of FIGS. 2 and 3 is coated with 3.7% sodium metaborate dihydrate.

The storage-stable produced by the process according to the invention Sodium percarbonate is stabilized by a coating with a coating agent containing sodium borate, in particular Sodium metaborate. The coating agent may be next to it still sequestering agent, for. B. ethylenediaminetetraacetate, nitrilotriacetate or phosphates.  

The amount of the coating agent is preferably included 0.1 to 30 wt .-%, based on the sodium percarbonate. The amount of sodium borate in the coating agent is preferably at 10 to 100 wt .-%.

It was found that those coated with the sodium borate Particles have a high sprayability and that the sodium percarbonate coating effect is very high and that coated with sodium borate on the surface Sodium percarbonate in powder or granular form has much higher storage stability than boric acid coated sodium percarbonate in a bleach detergent. The electron micrographs of the surfaces The sodium percarbonate particles show a uniform Coating with the sodium borate. This fact proves that the coating method according to the invention highly effective is.

For coating the sodium percarbonate with sodium borates according to the invention can be used be, for. b. Sodium tetraborate decahydrate (Na₂O · B₂O₃ · 10H₂O), Natriumtetraboratpentahydrat (Na₂O · 2B₂O₃ · 5H₂O), sodium tetraborate tetrahydrate (Na₂O · 2B₂O₃ · 4H₂O), anhydrous Natriumtetraborat (Na₂O · 2B₂O₃), sodium octaborate tetrahydrate (Na₂O · 4B₂O₃ · 4H₂O), Sodium pentaborate pentahydrate (Na₂O · 5B₂O₃ · 10H₂O), Sodium metaborate tetrahydrate (NaBO₂ · 4H₂O) and sodium metaborate dihydrate (NaBO₂ · 2H₂O). From the above Sodium borates are especially sodium metaborate dihydrate and sodium metaborate tetrahydrate.  

The coating composition used according to the invention can various organic and inorganic compounds in Combination to contain sodium borate. Suitable inorganic Connections are z. For example, sodium carbonate, Glauber's salt and magnesium sulfate. Suitable organic compounds are z. Organic high molecular compounds, such as polyethylene glycol, polyvinyl pyrrolidone and hydroxypropyl cellulose. The sodium borates can be used are used in combination with a sequestering agent, z. B. nitrilotriacetate or ethylenediaminetetraacetate. The Amount of sequestering agent is preferably included 0.01 to 3 wt .-%, based on the sodium percarbonate.

The sodium percarbonate can with a a sodium borate-containing coating composition according to customary Process are coated, for. By using a solution of the coating agent or by mixing a powdery one Coating agent with wet or dry Sodium percarbonate powders or granules to a uniform Adsorption, and then the mixture dried. The coated sodium percarbonate particles have an average particle diameter of 100 to 2000 .mu.m, in particular 250 to 1000 .mu.m.

According to the invention, a method for coating the Sodium percarbonate is being developed on an industrial scale can be and where the sodium percarbonate completely coated with the sodium borate. It was determined, that the properties of sodium borate containing Coating agent are particularly suitable for this. On particularly advantageous method is using of water wetted sodium percarbonate, the then with the sodium borate containing powdery coating agent is mixed and that the coating agent is adsorbed on the sodium percarbonate, and Thereafter, the agent is dried at temperatures that not lower than the temperature at which the used Sodium borate melts or begins to melt. at  the procedure given above, the sodium borate, if it in the form of powdery, containing water of crystallization Sodium borate to the sodium percarbonate in the wet state is sprayed on and then not at a temperature below the melting temperature of the respective sodium borate is dried, dissolved in the water of crystallization and melts, and so the sodium percarbonate will be complete surrounded by the molten sodium borate. The melting temperatures the sodium borates are z. At: Na₂B₄O₇ · 10H₂O: 75 ° C, NaBO₂ · 4H₂O: 57 ° C, NaBO₂ · 2H₂O: 90 ° C.

At this stage, the water becomes the sodium percarbonate and the water of crystallization of the sodium borate evaporates and the drying stage completed simultaneously. To this Way, a uniform film is formed, which is the sodium percarbonate wrapped and the drying process is stopped. Usually, sodium percarbonate can be used at 40 to 160 ° C are dried. The drying can also be used at Temperatures below 40 ° C are performed, the Drying time but then extended accordingly. At a temperature above 160 ° C finds an undesirable Decomposition of the sodium percarbonate takes place, and it comes it to oxygen losses. The drying temperature is preferably not lower than the melting temperature of used sodium borate, but not higher than 160 ° C.

The anhydrous sodium borates have a higher melting point as the corresponding hydrate compounds (eg. Na₂B₄O₇ with a melting point of 741 ° C). The melting points The anhydrous sodium borates are slightly lower due to the influence of moisture in the moistened Sodium percarbonate is included. It can be anhydrous Sodium borate can be used but also sodium borate can be used for the serving, the Contain crystal water. The amount of sodium borate in the sodium borate coating is 0.04 to 10 W / W%, preferably 0.1 to 5 W / W% (in terms of boron) based on dry sodium percarbonate. Preferably, small  Sodium borate particles used. The particle size of the sodium borate is about 50 to 300 microns, preferably 100 to 150 microns.

As sodium percarbonate, the percarbonate can be used by the usual reaction of sodium carbonate with hydrogen peroxide and subsequent dehydration is won. This percarbonate is in the wet state a moisture content of 7 to 18%. Because the moisture content of percarbonate used for the serving can be made, the thus prepared moist sodium percarbonate as such in the process of the invention be used. The moisture content of the used However, sodium percarbonate is preferably included 10 to 16%. If the moisture content below this Limit is the sodium percarbonate is preferred moistened, so that the powdered sodium borate evenly can be sprayed on.

It is advantageous if the coating agent has a contains usual stabilizer for sodium percarbonate, z. Ethylenediamine tetraacetate or a sequestering agent, z. B. nitrilotriacetate, which is not detrimental Has an effect on the film formation of the molten sodium borate.

In the preparation of the coated with a sodium borate Sodium percarbonate can coat the sodium percarbonate by spraying with an aqueous solution of sodium borate by mixing with a powder and then Dry. As with this method, however, dry Sodium percarbonate is used, it is necessary to to carry out the drying process twice.

Alternatively, the sodium percarbonate may also be coated be prepared by using a sodium percarbonate powder, which is moistened with water, preferably in the form, as in the production of sodium carbonate with hydrogen peroxide from the aqueous solution  is obtained, d. H. by mixing the sodium percarbonate in the wet state with powdered sodium borate and then Dry. This process is industrial Can be used on a large scale, as it is easy to carry out is and requires only small amounts of energy and the sodium borate must be resolved separately.

In the method according to the invention are with the sodium borate compound coated sodium percarbonate particles obtained, wherein the coating is uniform and uniform.

The sodium percarbonate particles according to the invention thus prepared have a high storage stability, namely even if the particles in usual powdery Cleaners (spray-dried cleaners) or especially when they are in zeolithhaltige phosphorarmarme or phosphorus-free detergents are mixed.

Sodium percarbonate is usually caused by moisture and by the presence of heavy metal salts and other impurities in the detergent are contained, decomposed, so that the available Oxygen content is reduced accordingly. This Disadvantage occurs in the sodium percarbonate according to the invention not on, so that the invention stabilized Particles do not survive in their storage stability Moisture, by bleach activating agents, enzymes, Brighteners, fragrances, etc. are impaired. On This way it is possible with the invention Means a high quality household bleach with a lot to provide good storage stability.  

Usually, untreated sodium percarbonate will be used by transition metal salts, e.g. As cobalt, iron or Copper salts and decomposed by gelating. If Activating agent and sodium percarbonate in a mixture used, it also leads to a decomposition reaction, the commercial value of the household detergent is significantly affected by the Odor of the released carboxylic acid, in particular Acetic acid caused by the decomposition of the activating agent is formed.

Even if the coated sodium percarbonate is incorporated into a detergent composition containing an enzyme or a brightener, usually to a decomposition of the sodium percarbonate lead, no impairment of storage stability on. It can even phosphorus-free detergent mixtures are prepared, the inventive Sodium percarbonate in combination with enzymes and brighteners contained, without affecting the storage stability becomes.  

sequestering agents

The mixture contains 0 to 50% by weight of one or more Builder selected from the group consisting of alkali metal salts and alkanolamine salts of the following Line-up:

• 1) salts of phosphoric acids, eg. B. orthophosphoric acid, Pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid, Hexametaphosphoric acid or phytic acid.
• 2) salts of phosphorous acid, eg. Ethane-1,1-diphosphonic acids, Ethane-1,2-triphosphoric acid or Ethane-1-hydroxy-1,1-diphosphoric acid and derivatives thereof, Ethane-hydroxy-1,1,2-triphosporic acid, ethane 1,2-dicarboxy-1,2-diphosphoric acid or methane hydroxyphosphorigesäure.
• 3) salts of phosphocarboxylic acids, eg. B. 2-phosphorous acid butane-1,2-dicarboxylic acid, 1-phosphorous acid butane-2,3,4-tricarboxylic acid or α-methylphosphosuccinic acid.
• 4) salts of the amino acids, eg. B. aspartic acid and Glutamic acid.  
• 5) salts of aminopolyacetic acids, eg. B. nitrilotriacetic acid, Ethylenediaminetetraacetic acid or diethylenetriaminepentaacetic acid.
• 6) high molecular weight electrolytes, eg. B. polyacrylic acid, polyaconitic acid, Polyitaconic acid, polycitraconic acid, polyfumaric acid, Polymaleic acid, polymesaconic acid, poly-α- hydroxyacrylic acid, polyvinylphosphorous acid, sulfonated Polymaleic acid, maleic anhydride / diisobutylene copolymer, Maleic anhydride / styrene copolymer, maleic anhydride / Methyl vinyl ether copolymer, maleic anhydride / Ethylene copolymer, maleic anhydride / ethylene crosslinked copolymer, maleic anhydride / vinyl acetate copolymer, Maleic anhydride / Acrylonitrilcopolymerisat, Maleic anhydride / acrylate copolymer, Maleic anhydride / butadiene copolymer, maleic anhydride / Isoprene copolymer, poly-β-ketocarboxylic acid, derived from maleic anhydride and carbon monoxide, Itaconic acid / ethylene copolymer, itaconic acid / aconitic acid copolymer, Itaconic / Maleinsäurecopolymerisat, Itaconic acid / acrylic acid copolymer, malonic acid / methylene copolymer, Mesaconic / Fumarsäurecopolymerisat, Ethylene glycol / ethylene terephthalate copolymer, vinyl pyrrolidone / Vinyl acetate copolymer, 1-butene-2,3,4-tricarboxylic acid / Itaconic acid / acrylic acid copolymer, polyester polyaldehydarbonsäure, containing a quaternary Ammonium group, cis isomer of epoxysuccinic acid, poly [N, N-bis (carboxymethyl) acrylamide], poly (oxycarboxylic acids), Starch succinate, maleate or terephthalate, starch phosphate, Dicarboxystärke, dicarboxymethyl starch or cellulose succinate.
• 7) non-dissociating higher molecules, e.g. For example, polyethylene glycol, Polyvinyl alcohol, polyvinylpyrrolidone or cold-water soluble urethanized polyvinyl alcohols.
• 8) salts of organic acids, such as. B. diglycolic acid, Hydroxydiglycolic acid, carboxymethyloxysuccinic acid, Cyclopentane-1,2,3,4-tetracarboxylic acid, tetrahydrofuran 1,2,3,4-tetracarboxylic acid, tetrahydrofuran-2,2,5,5-tetracarboxylic acid, Citric acid, lactic acid or tartaric acid,  carboxymethylated products of sucrose, lactose or Raffinose, carboxymethylated pentaerythritol, carboxymethylated Gluconic acid, condensates of polyhydric alcohols or sugar with maleic or succinic anhydride, Condensates of hydroxycarboxylic acid with maleic or succinic anhydride Benzene polycarboxylic acids, e.g. B. Mellitic acid, Ethane-1,1,2,2-tetracarboxylic acid, ethene-1,1,2,2-tetracarboxylic acid, Butane-1,2,3,4-tetracarboxylic acid, propane-1,2,3- tricarboxylic acid, butane-1,4-dicarboxylic acid, oxalic acid, Sulfosuccinic acid, decane-1,10-dicarboxylic acid, sulfotricarboxylic acid, Sulfoitaconic acid, maleic acid, hydroxydisuccinic acid or gluconic acid, CMOS or Builder M.
• 9) Aluminum silicates:
  number 1
  Crystalline aluminosilicates of the general formula: x '(M₂'O or M''O) .Al₂O₃.Y' (SiO₂) .W '(H₂O) wherein M' represents an alkali metal atom, M '' represents an alkaline earth metal atom exchangeable with calcium and x ', y' and w ', each corresponding to the number of moles of the corresponding component, satisfy the requirement of 0.7 ≦ x' ≦ 1.5, 0.8 ≦ y '≦ 6, and w' represents an integer.
  No. 2
  A detergent builder of the following general formula: Na₂O.Al₂O₃.nSiO₂.wH₂Oworin n is a number from 1.8 to 3.0 and w is an integer from 1 to 6.
  No. 3
  Amorphous aluminosilicates of the general formula x (M₂O) .Al₂O₃.y (SiO₂) .w (H₂O) where M is sodium and / or potassium and x, y and w are each the number of moles of the corresponding component, as follows. 7 <x ≦ 1.21.6 ≦ y ≦ 2.8 and wherein w is a whole positive number including 0.
  No. 4
  Amorphous aluminosilicates of the general formula X (M₂O). Al₂O₃.Y (SiO₂) .Z (P₂O₅). Ω (H₂O) where M stands for Na or K and X, Y, Z and ω for the respective number of moles of the respective component with the following provisional: 0.20 ≦ X ≦ 1100.20 ≦ Y ≦ 4,000,001 ≦ Z ≦ 0.80 and wherein ω is a whole positive number including 0.

In detail, the incorporation of the alkali metal silicates explained in the coating agent.

The mechanical strength of the coating on the sodium percarbonate is improved if the to be displayed Sodium borate an alkali metal silicate is mixed. In this case, there is no danger that the coating during handling of the coated sodium percarbonate particles damaged, especially not during mixing with powdered detergents.

Suitable alkali metal silicates are those of the formula Na₂O · nSiO₂, wherein n stands for the number of moles of SiO₂ / Na₂O and N is preferably 0.5 to 4. Suitable examples for such alkali metal silicates are the aqueous solution a crystalline sodium silicate, e.g. B. sodium orthosilicate  (2Na₂O · SiO₂ · xH₂ =, n = 0.5), sodium sesquisilicate (3Na₂O · 2SiO₂ · xH₂ =, n = 0.67), sodium metasilicate (Na₂O · SiO₂ · xH₂O, n = 1), the aqueous solution of an amorphous Sodium silicate, z. B. Na₂O · nSiO₂ (n = 1-4) and anhydrous sodium silicate powder thereof.

The thus coated sodium percarbonate particles show excellent storage stability and even then, when in usual powdered detergent (spray-dried products) are incorporated, in particular but even if they are in low-phosphorus or phosphorus-free Detergents containing zeolites are mixed. When combining sodium borates and alkali metal silicates used for the coating, the particles have a particularly high strength without thereby solubility of the sodium percarbonate is impaired. On This will ensure that the coating during the stage of mixing with the powdery ones Detergents will not be damaged.  

Stabilizers for the peroxides

Furthermore, stabilizers can be added to the mixture for the peroxides, z. B. magnesium silicate, magnesium sulfate, Magnesium oxide and magnesium chloride.

In an advantageous embodiment of the invention, the Sodium percarbonate by coating with a coating agent, containing a sodium borate and a magnesium compound, be stabilized. In addition to sodium borate is preferred Sodium metaborate used. As a magnesium compound is in particular one or more compounds selected from magnesium chloride, Magnesium oxide, magnesium sulfate and magnesium silicate, suitable.

Furthermore, the coating composition can be a sequestering agent, z. Ethylenediaminetetraacetate or nitrilotriacetate, contain.  

The sodium percarbonate is used in an amount of preferably 0.1 to 30 wt .-%, based on the amount of the coating agent and the sodium borate is used in an amount of preferably 10 to 95% by weight and the Magnesium compound in an amount of preferably 5 to 70 wt .-%, based on the amount of the coating agent. Preferably, the magnesium compound does not become used in a larger amount than the sodium borate.

It has been found that when using a coating agent consisting of a mixture of sodium borate and magnesium compound have a synergistic effect the stabilization occurs and that the so coated Sodium percarbonate when in a powdered Cleaning agent is incorporated or in a bleach a particularly high storage stability is incorporated having.

Suitable magnesium compounds are magnesium sulfate, Magnesium chloride, magnesium oxide, magnesium hydroxide, Magnesium silicate, magnesium nitrate, magnesium phosphate and magnesium carbonate in anhydrous or in hydrated state and the magnesium salts of various organic acids. Especially preferred thereof are magnesium sulfate, magnesium chloride, magnesium oxide and magnesium silicate in anhydrous or hydrated Shape.

The invention will be more apparent from the following examples explained.

Example 1

Moist sodium percarbonate with a moisture content of 10% and a mean dry particle size of 480 μm (prepared by reaction of hydrogen peroxide with sodium carbonate in aqueous solution) is dissolved in a continuous mixer with a  Addition rate of 5.3 kg / min given. Furthermore, sodium metaborate dihydrate having a mean particle size of 150 μm in the mixer at an addition rate of 0.178 kg / min. The addition rates become so adjusted that a residence time in the mixer of 5 min is reached. The mixture discharged from the mixer is continuously fed to a flow dryer and dried at 130 ° C therein.

The amount of boron in the coated sodium percarbonate is 0.42%, based on boron. The coated Sodium percarbonate comes with various Blended additives and then the stability of the Mixture examined. The results are in Table 1 summarized. The stability is expressed as Amount of residual oxygen provided the storage of a sample in a hole-equipped Plastic container for 24 h at 50 ° C and 80% relative humidity.  

Table 1

example 2

3.4 g of moist sodium percarbonate with a moisture content of 12% and a medium dry Particle size of 400 microns and 0.1 kg of sodium borate decahydrate become a batch mixer  and mixed therein for 1 min. The mixture is dried in a flow dryer at 160 ° C. The amount to boron in the coated sodium percarbonate 0.40%, calculated on boron.

For comparison, the above procedure is repeated, however with the exception that 0.16 kg of sodium carbonate, 0.78 kg colloidal silica (SiO 2 content 20%) and 0.31 kg No. 3 Sodium silicate as a coating agent instead of Sodium borate decahydrate can be used. The so produced coated sodium percarbonate is mixed with a commercially available detergent mixture A (phosphorus-free Cleaning agent containing zeolite) in the mixing ratio of 9: 1 mixed and in a hole-equipped Plastic container for 2 weeks at Stored at 40 ° C and a relative humidity of 80%. The thereafter still available amounts of oxygen are measured to determine the stability of the products. The results are summarized in Table 2.

Table 2

example 3

It is a coated polycarbonate according to Examples 1 and 2 and then a storage stability test subject to the following conditions:

• (1) 10% by weight of the coated PC is mixed with a commercial detergent B (phosphorus-free Detergent containing zeolite)
• (2) 10% by weight of the coated PC is mixed with a commercial detergent C (phosphorus-containing Detergent containing sodium tripolyphosphate).

10 g of each mixture are in a 50 cm³ large Plastic container given. Then the container is closed and for 14 days at 40 ° C and 80% relative Humidity left and after that is the still cleavable oxygen radical according to the following Equation determined:

Provided residual oxygen content (%)

The amount of oxygen provided was measured by titration with 0.1 N potassium permanganate solution.

For comparison, uncoated PC (1) is obtained by drying wet PC and (2) sodium perborate (PB) in addition to the coated PC.

Example 4

100 g of sodium percarbonate are in a mixer with Stirred, then a 25% aqueous solution of 5 g sodium metaborate tetrahydrate (NaBO₂ · 4 H₂O) (prepared by dissolving with heating) on the with Sodium percarbonate stirred at a speed of 250 rpm sprayed. After stirring for 10 min the mixture is dried with warm air to produce the coated sodium percarbonate.

For comparison, a sodium percarbonate coated with boric acid is prepared (2.4 g of boric acid per 100 g Sodium).

10% by weight of the coated sodium percarbonate homogeneous with a phosphorus-free powdered detergent mixture mixed with the following composition to prepare a bleach detergent.

Phosphorus free bleach detergent Wt .-% sodium dodecyl benzene sulfonate 20.0 synthetic zeolite (type 4A) 20.0 Sodium silicate (JIS No. 2) 10.0 sodium 5.0 fluorescent dye 0.5 Sodium salt of carboxymethylcellulose 1.0 Enzyme (Alcalase) 0.3 Sodium percarbonate (coated with sodium metaborate according to the invention) 10.0 water 5.0 sodium sulphate compensation amount a total of 100

Three samples according to the above composition and for comparison, a boric acid coated and an uncoated sodium percarbonate sample are stored as indicated in Example 3 and then the stability is measured. The results are in Table 3 summarized.

Table 3

Coating amount of NaBO 2: 2.4%.

The results of Table 3 show that stability the sodium percarbonate sample coated according to the invention is considerably better than the boric acid coated sample. Is remarkable also that the sodium percarbonate sample coated according to the invention has a high stability although the detergent is a completely phosphorus free Detergent containing zeolite.

Example 5

Sodium percarbonate is mixed with a mixture from sodium metaborate with other coating agents in the same manner as given in Example 4, coated. The coating agents used are below listed. The quantities of coating agents are in wt .-%, based on the sodium percarbonate.

• (1) 5% sodium metaborate (NaBO₂ · 4H₂O) + 5% polyethylene glycol (PEG, MW: 6000)
• (2) 5% sodium metaborate + 5% sodium carbonate
• (3) 5% sodium metaborate + 0.5% disodium ethylenediaminetetraacetate (EDTA)
• (4) 5% sodium metaborate + 0.5% EDTA. Di-triethanolamine and
• (5) 5% sodium metaborate + 0.5% trisodium nitrilotriacetate (NTA).

Six samples, namely five samples with a coating as indicated above and an uncoated sodium percarbonate sample be in the same phosphorus-free Detergent mixed according to Example 4, wherein the amount of sodium percarbonate is 10% by weight. The The resulting mixtures are then subjected to the same storage conditions subjected as indicated in Example 4. The results after storage are summarized in Table 4.

Table 4

The results of the table show that when sodium metaborate in combination with other coating agents is used, a very good storage stability of sodium percarbonate is reached. Especially if Sodium metaborate together with an organic high molecular weight compound, for. PEG or one Sequestering agents, e.g. B. EDTA or NTA is used over a synergistic effect a particularly good storage stability reached.

Example 6

The solubilities, compressive strength and disintegration properties of the coated sodium percarbonate according to Example 5 are examined. The results are in Table 5 summarized.

solubility

To 1 liter of city water in a 1 liter beaker was added 1 g granulated sodium percarbonate added and The mixture is stirred at 200 rpm. It will be the Time measured until the measured electrical conductivity the solution is constant after the beginning of the stirring.

Compressive strength

A certain amount of a sample will compressed under given conditions. It will measured the load that is necessary to control the amount of powder to compress 1 cm. The recording will made with an autographic recorder.

disintegration properties

100 g of a sample by a Screen of a mesh size of 1.65 mm has been screened, but not through a sieve of mesh size 0.178 mm go through, put in a 500 ml plastic bottle given with a wide neck. Then 50 g of steel balls filled with a diameter of 3 mm into the bottle and the bottle closed. After that, the bottle becomes clamped in a shaker and with 360 rpm shaken for 10 min at an amplitude of 4.5 cm.  

The decay properties are in the crowd (Wt .-%) of the sample, which after the shaking by sieved a sieve with a mesh size of 0.178 mm has been. The smaller the amount in wt% that is screened through can be, the better are the strength properties of the powder.

The results of Table 5 show that the solubility, the compressive strength and disintegration property of sodium percarbonate not affected by the coating has been.

Example 7

20 kg of a moist Natriumpercarbonats be in a Centrifugal diffusion mixer (FKM-130 D, T.M. Engineering Co., Ltd.). A powdered coating agent is added with stirring and the mixture is mixed for a total of 10 minutes. Then the coated one Sodium percarbonate taken out and with Warm air dried.

As the coating agent, the following compounds used:

• (1) 5% sodium metaborate (NaBO₂ · 4H₂O) + 0.5% EDTA · 2 TEA
• (2) 4.54% borax (Na₂B₄O₇ · 10H₂O) + 0.5% EDTA · 2 TEA and
• (3) 2.4% boric acid (H₃BO₃) + 0.5 EDTA · 2 TEA

The percentages are based on wt .-%, based on Sodium.

There are three samples, two coated sodium percarbonate samples and a comparative sample and a uncoated sodium percarbonate sample and then pulled in an amount of 10% by weight in the following phosphorus-free Detergent mixture in the same way as specified in Examples 4 and 5 mixed. It becomes the storage stability as in Example 4 Examined and the results are shown below Table 6 summarized. Next to it is the residual activity of the enzyme (2.0 M Alcalase) incorporated into the mixture has been determined as well. The enzymatic Residual activity is determined by the following formula:

Enzymatic residual activity in% logo CNRS logo INIST

The method for measuring the residual activity of enzymes is in J.B.C. 244 (4), pages 789-793 (1969) and Analyst 96, pages 159-163 (1971).

Phosphorus free bleach detergent Wt .-% sodium dodecyl benzene sulfonate 20.0 synthetic zeolite (type 4A) 20.0 Sodium silicate (JIS No. 2) 10.0 sodium 5.0 fluorescent dye 0.5 Sodium salt of carboxymethylcellulose 1.0 Enzyme (2.0 M Alcalase) 0.3 Sodium percarbonate (coated) 10.0 water 5.0 sodium sulphate as compensation amount a total of 100

Table 6

The results of Table 6 show that the prepared phosphorus-free bleaching detergent 1 and 2 an extremely high stability with regard to the sodium percarbonate and the enzyme although containing zeolite.

Example 8

In a powdery bleach of the following composition, 10 wt .-% of the invention coated sodium percarbonate according to Example 7 (Sodium percarbonate coated with NaBO₂ · 4 H₂O or Na₂B₄O₇ · 10 H₂O) or one or two comparison samples (Sodium percarbonate coated with H₃BO₃ or uncoated Sodium percarbonate) incorporated. The storage stability and the residual enzyme activity (2.0 M Alcalase) are examined. The results are summarized in Table 5. The examination methods are the same as in the Examples 4 and 7 indicated.

Bleach Cleaner Wt .-% sodium dodecyl benzene sulfonate 20.0 sodium tripolyphosphate 18.0 Sodium silicate (JIS No. 2) 10.0 sodium 5.0 fluorescent dye 0.5 Sodium salt of carboxymethylcellulose 0.5 Enzyme (2.0 M Alcalase) 0.3 sodium 10.0 water 5.0 sodium sulphate until the balance a total of 100

Table 7

Contain the bleach cleaners in this example STPP, which is contained in usual cleaning agents. Samples 1 and 2 containing the storage stable sodium percarbonate according to the invention are also in the presence of sodium tripolyphosphate storage stable.

Example 9

100 g of sodium percarbonate are placed in a shaking mixer given. Then 5 g of sodium metaborate (Na₂BO₂ · 4 H₂O prepared by dissolving metaborate in water Heating) in the form of a 25% aqueous solution and 1 g (based on solid) sodium silicate (JIS No. 3) (NH₂O · 2 SiO₂ · aq) in the form of a 25% aqueous solution sprayed the sodium percarbonate with one revolution of 250 rpm is stirred. After stirring for 10 minutes The sodium percarbonate is dried with warm air to the produce coated material.

For comparison, sodium percarbonate is coated with 7.1 g of sodium metaborate Na₂BO₂ · 4 H₂O per 100 g of starting material,  with 3.4 g of boric acid per 100 g of starting material, 2.4 g of boric acid and 1 g of JIS No. 3 sodium silicate per 100 g of starting material and with 3.4 g based on solid JIS No. 3 sodium silicate based on 100 g of starting material.

10% by weight of the respective coated samples evenly in a powdered phosphorus-free detergent of the following composition to prepare the following bleach detergent:

Phosphorus free bleach detergent Wt .-% sodium dodecyl benzene sulfonate 20.0 synthetic zeolite (type 4A) 20.0 Sodium silicate (JIS No. 2) 10.0 sodium 5.0 fluorescent dye 0.5 Sodium salt of carboxymethylcellulose 1.0 Enzyme (Alcalase) 0.3 sodium 10.0 water 5.0 sodium sulphate until the balance a total of 100

The six samples with the different coatings and for comparison, a coated sample in the mixture with the above detergent composition are examined for storage stability. The Results are summarized in Table 8.

The results of the table show that the available Asked residual oxygen quantity in the Examples containing the storage-stable sodium percarbonate prepared according to the invention are higher than in Comparative Examples 3 to 7 and that these examples in terms the coating effect of those of the comparative examples 3 to 6 are superior.

The bleaching agents used contain no phosphate, but a zeolite and still are the invention Stable samples.

Example 10

The solubility, compressive strength and disintegration property the coated sodium percarbonate samples according to Example 9 was examined. The results are in Table 9 summarized.

The results of Table 9 show that the solubility is essentially unchanged, although the sodium percarbonate has been coated according to the invention and that significantly improved the disintegration property of the particles when the coating with sodium metaborate and sodium silicate made according to the example of the invention becomes.

Example 11

Sodium percarboant is prepared according to the method of Example 9 using various sodium silicates coated in combination with sodium metaborate. The composition the coating agent is listed below:

5% NaBO₂ · 4 H₂O + 1% sodium orthosilicate, (based on solids)
5% NaBO₂ · 4 H₂O + 1% sodium metasilicate, (based on solids)
5% NaBO₂ · 4 H₂O + 1% sodium silicate, (JIS No. 1) (based on solids)
5% NaBO₂ · 4H₂O + 1% sodium silicate, (JIS No. 2) (based on solids)
5% NaBO₂ · 4H₂O + 1% sodium silicate, (JIS No. 3) (based on solids) and
7.1% NaBO₂ · 4 H₂O

The above six coated sodium percarbonate samples and an uncoated comparative sample are in one Amount of 10 wt .-% in a phosphorus-free bleach-detergent mixture according to the composition of Example 9 incorporated. The storage stability of the samples is given in the same manner as in Example 9  examined. Further, the seven sodium percarbonate samples nor a decay investigation in similar Method as described in Example 10 examined. After completion of the decay test, the obtained Products of further investigation of storage stability subjected. The results are in table 10 summarized.

The results of Table 10 show that the Samples 1 to 5 a very good storage stability due to the coating. Using a coating of sodium borate and silicate, the coated Particles have a firmness with one Coating of sodium borate alone can not be achieved. The results from the study of storage stability after the decay investigation show that the resistance the coated particle is improved and that the coated particles during mixing with the detergent mixture and on the transport hardly affected in terms of storage stability even if they do not during the Transports are crushed.

Example 12

Sodium percarbonate is prepared by the method of Example 9 coated, but with the exception that sodium metaborate and sodium silicate as a mixture with other coating agents as indicated below. The amount of the coating agent is given in% by weight, based on sodium percarbonate:

5% NaBO₂ · 4H₂O + 1% sodium silicate (JIS No. 3) (based on solids) + 5% polyethylene glycol (PEG, MW + 6000)
5% NaBO₂ · 4 H₂O + 1% sodium silicate (JIS No. 3) (based on solids) + 5% sodium carbonate
5% NaBO₂ · 4H₂O + 1% sodium silicate (JIS No. 3) (based on solids) + 0.5% disodium ethylenediaminetetraacetate (EDTA)
5% NaBO₂ · 4H₂O + 1% sodium silicate (JIS No. 3) (based on solids) + 0.5% EDTA, di (triethanolamine) salt and
5% NaBO₂ · 4H₂O + 1% sodium silicate (JIS No. 3) (based on solids) + 0.5% trisodium nitrilotriacetate (NTA)

The above five samples and an uncoated sodium percarbonate sample be in a lot of 10% by weight in a phosphorus-free bleach detergent of the same composition as given in Example 9 incorporated. The storage stability is in the same The procedure as described in Example 9 examined. The results are summarized in Table 11.

The results of Table 11 show that sodium percarbonate even then has a good storage stability, if it is with sodium perborate, sodium silicate and others Coating agents coated in combination. A particularly good stability effect can be achieved in a coating mixture of sodium silicate, an organic high molecular weight compound, e.g. B. PEG or a sequestering agent such as EDTA or NTA. in this connection apparently a synergistic stability effect is achieved.

Example 13

20 kg of moist sodium percarbonate are placed in a centrifugal diffusion mixer (FKM-130D, T.M. Engineering Co., Ltd.) and then becomes a powdery coating agent added with stirring. The mixture is stirred for a total of 10 minutes, then becomes the coated sodium percarbonate removed and dried with warm air. It will be the following coating agents used:

5% sodium metaborate (NaBO₂ · 4H₂O) + 1% sodium silicate (JIS No. 3) (based on solids) + 0.5% EDTA · 2 TEA
4.54% borax (Na₂B₄O₇ · 10H₂O) + 1% sodium silicate (JIS No. 3) (based on solids) + 0.5% EDTA · 2 TEA and
2.4% boric acid (H₃BO₃) + 1% sodium silicate (JIS No. 3) (based on solids) + 0.5% EDTA · 2 TEA.

The percentages are based on wt .-%, based on sodium percarbonate.

10 g of the above three coated sodium percarbonate samples and an uncoated sodium percarbonate control sample  are converted into a phosphorus-free bleach detergent the composition according to Examples 9 and 10 incorporated to prepare the following mixtures. Then, the storage stability of the samples becomes as in Example 9 examined and the results are summarized in Table 12. Furthermore, the residual enzyme activity (Alcalase 2.0 M).

Phosphorus free bleach detergent Wt .-% sodium dodecyl benzene sulfonate 20.0 synthetic zeolite (type 4A) 20.0 Sodium silicate (JIS No. 2) 10.0 sodium 5.0 fluorescent dye 0.5 Sodium salt of carboxymethylcellulose 1.0 Enzyme (Alcalase 2.0 M) 0.3 Sodium percarbonate (coated) 10.0 water 5.0 sodium sulphate until the balance a total of 100

The results of Table 12 show that sodium percarbonate and also the enzyme have a very good stability even if bleach detergent 1 and 2 zeolite added is.

Example 14

In a powdered bleach detergent according to the The following composition is 10 wt .-% of the According to the invention coated sodium percarbonate according to Example 13 and two comparative samples (one coated with H₃BO₃ in combination with sodium silicate and prepared according to example 5 and a second sample uncoated) incorporated. The storage stability is in the same As described in Examples 9 and 13 described. The results are in Table 13 summarized.

Bleach Cleaner Wt .-% sodium dodecyl benzene sulfonate 20.0 sodium tripolyphosphate 18.0 Sodium silicate (JIS No. 2) 10.0 sodium 5.0 fluorescent dye 0.5 Sodium salt of carboxymethylcellulose 0.5 Enzyme (Alcalase 2.0 M) 0.3 sodium 10.0 water 5.0 sodium sulphate until the balance a total of 100

The samples prepared according to the invention have a very good storage stability even though the detergent mixture STPP contains. The results show that the invention Substances have a good storage stability and indeed regardless of whether a zeolite in the detergent mixture is present or not.

Example 15

100 g of sodium percarbonate are placed in a shaking mixer and then 5 g of sodium metaborate tetrahydrate (NaBO₂ · 4H₂O) prepared by dissolving the metaborate in Water with heating) in the form of a 25% aqueous Solution and 1 g of anhydrous magnesium sulfate in the form a 25% aqueous solution of the sodium percarbonate are sprayed with stirring at 250 rpm. After a Total stirring time of 10 min will be the sodium percarbonate with warm air dried around the coated product manufacture.

For comparison, sodium percarbonate is coated with only sodium metaborate (7.1 g NaBO₂ · 4 H₂O per 100 g Sodium percarbonate), with 3.4 g of boric acid per 100 g Percarbonate, with 2.4 g of boric acid and 1 g of magnesium sulfate per 100 g percarbonate and 3.4 g MgSO₄ per 100 g percarbonate. It is used in each case anhydrous MgSO₄.

Each 10 wt .-% of the thus prepared coated Sodium percarbonate samples become evenly powdered phosphorus-free detergent mixed in, to prepare a composition as indicated below.

Phosphorus free bleach detergent Wt .-% sodium dodecyl benzene sulfonate 20.0 synthetic zeolite (type 4A) 20.0 Sodium silicate (JIS No. 2) 10.0 sodium 5.0 fluorescent dye 0.5 Sodium salt of carboxymethylcellulose 1.0 Enzyme (Alcalase) 0.3 sodium 10.0 water 5.0 sodium sulphate until the balance a total of 100

Six of the samples coated as above and an uncoated comparative sample will be given the storage stability examined. The results are in Table 14 summarized.

The results of Table 14 show that the Samples which coated a sodium percarbonate prepared according to the invention containing sodium metaborate and magnesium sulfate, one have significantly better stability than Comparative Examples 8 to 12.

The samples are in terms of coating those of comparative samples 8 to 11 far think. The stability is with the present samples although it is phosphorus-free Detergents acts.

Example 16

Sodium percarbonate is given as in Example 15 with different magnesium compounds in combination coated with sodium metaborate. The coating agents are listed below:

5% NaBO₂ · 4 H₂O + 1% MgSO₄ (based on anhydrous solids)
5% NaBO₂ · 4 H₂O + 1% MgCl₂ (based on anhydrous solids basis)
5% NaBO₂ · 4 H₂O + 1% 2 MgO · 3 SiO₂ (based on anhydrous solids basis
5% NaBO₂ · 4 H₂O + 1% MgO (based on anhydrous solids basis) and
7.1% NaBO₂ · 4 H₂O.

10% by weight of the above five samples plus one uncoated Sodium percarbonate sample are transformed into a phosphorus-free Bleach detergent in the same As indicated in Example 15, incorporated. It will be the Storage stability in the same manner as in Example 15 specified examined. The results are in Table 15 summarized.  

Table 15

The results of Table 15 show that the Samples 1 to 4 a very good storage stability have.

Example 17

Sodium percarbonate is as in Example 15 with the exception that sodium metaborate and Magnesium sulfate in combination with others Coating agents were used. The amount of piled up Means in wt .-%, based on sodium percarbonate:

5% NaBO₂ · 4 H₂O + 1% MgSO₄ (on anhydrous substance basis) + 5% polyethylene glycol (PEG, MW = 6000)
5% NaBO₂ · 4 H₂O + 1% MgSO₄ (on anhydrous solids basis) + 5% sodium carbonate
5% NaBO₂ · 4 H₂O + 1% MgSO₄ (based on anhydrous solids) + 0.5% disodium ethylenediaminetetraacetate (EDTA · 2 Na)
5% NaBO₂ · 4 H₂O + 1% MgSO₄ (based on anhydrous solids) + 0.5% EDTA · di (triethanolamine) salt (2 TEA) and
5% NaBO₂ · 4 H₂O + 1% MgSO₄ (based on anhydrous solids) + 0.5% trisodium nitrilotriacetate (NTA · 3 Na).

10 wt .-% of the above five coated samples and a uncoated sodium percarbonate sample in a phosphorus-free bleach detergent of the same composition as in Example 15 specified, incorporated. The storage stabilities are in analog The procedure as described in Example 15 examined. The results are summarized in Table 16.

Table 16

The results of Table 16 show that the invention Examples 1 to 5 a very good storage stability relative to the comparative sample. Both Coating agents appear to be more synergistic Effect on the stabilization of the percarbonate.

Example 18

The solubility, compressive strength and disintegration properties the coated sodium percarbonate samples according to Example 17 were examined. The results are summarized in Table 17.

The results of Table 17 show that the corresponding Properties of coated percarbonate particles are about the same as those of the uncoated ones Sodium.

Example 19

20 kg of moist sodium percarbonate is placed in a centrifugal diffusion mixer given and then a powdered Coating added with stirring. The mixture is carried out over a total time of 10 minutes and then the coated sodium percarbonate dried with warm air. There are the following coating agents used:

5% sodium metaborate (NaBO₂ · 4 H₂O) + 1% MgSO₄ (based on anhydrous solids) + 0.5% EDTA · 2 TEA,
4.54% borax (Na₂B₄O₇ · 10 H₂O) + 1% MgSO₄ (based on anhydrous solids) + 0.5% EDTA · 2 TEA and
2.4% boric acid (H₃BO₃) + 1% MgSO₄ (based on anhydrous solids) + 0.5% EDTA · 2 TEA

All percentages are wt .-%, based on sodium percarbonate.

10% by weight of the above three samples and one uncoated Comparative sample are added to a phosphorus-free bleach detergent mixed in to a mixture of the following Make composition. The storage stability of Samples are given in an analogous manner as in Example 15 examined. The results are in Table 18 summarized. Furthermore, the residual enzyme activity (Alcalase 2.0 M) of the detergent mixture.

Phosphorus free bleach detergent Wt .-% sodium dodecyl benzene sulfonate 20.0 synthetic zeolite (type 4A) 20.0 Sodium silicate (JIS No. 2) 10.0 sodium 5.0 fluorescent dye 0.5 Sodium salt of carboxymethylcellulose 1.0 Enzyme (Alcalase 2.0 M) 0.3 Sodium percarbonate (coated) 10.0 water 5.0 sodium sulphate until the balance a total of 100

The results of Table 18 show that the Samples 1 and 2 which contain the storage-stable sodium percarbonate have good storage stability and enzyme stability although the mixtures contain zeolite.

Example 20

10% by weight of the sodium percarbonate samples coated by the process according to the invention according to Table 18 and two comparative samples with a coating of H₃BO₃ and MgSO₄ produced according to Example 5 and an uncoated sodium percarbonate sample are added to a powdered bleach-detergent mixture incorporated, which instead of zeolite sodium tripolyphosphate in an amount of 18% by weight. The storage stabilities and the residual activity of the enzyme are measured. It follows that the inventive Samples with the coatings of Table 18 better storage stability and better residual enzyme activity have as the comparison sample with H₃BO₃ + MgSO₄ + EDTA · 2 TEA and the comparative sample without coating. The results show that the coated according to the invention Samples have good stability and Regardless of whether the detergent is zeolite or as in this case contains STPP.

Example 21

100 g of sodium percarbonate are placed in a shaking mixer and then 5 g of sodium metaborate tetrahydrate prepared by dissolving metaborate in water with heating in the form of a 25% aqueous solution Stirring of the percarbonate sprayed at 250 rpm. To a stirring time of a total of 10 minutes, the sodium percarbonate dried with warm air to make a coated Produce sodium percarbonate.

For comparison, sodium percarbonate with 2.4 g of boric acid per 100 g of sodium percarbonate coated.  

The so coated samples and one uncoated Sodium percarbonate sample in a bleach (1) having the following composition. The three samples of bleach composition become then undergo a storage test, and at the same time becomes the odor emanating from the samples is examined.

Bleaching composition (1)

Table 20

The results of Table 20 show that the Bleaching agent with regard to storage stability and with regard to odor nuisance to the comparative samples are considerably superior if they according to the invention prepared storage stable sodium percarbonate.

Example 22

The samples according to Example 21 and the Comparative samples of Example 21 become uniform incorporated into a bleaching mixture II. Samples are then subjected to a storage stability test, such as in Example 21. The results are in table 21 summarized.

Bleach mixture (2)

Table 21

The results of Table 21 show that the Bleaching composition a significantly better Has storage stability and although even if transition metal traces in the investigated Mixture are included, provided that they are according to the invention prepared storage stable sodium percarbonate contains.

Example 23

Sodium percarbonate is combined with sodium metaborate with other coating agents in a similar way coated in Example 21. The coating agents are given below. The quantities of coating agents are expressed in wt .-%, based on the amount of sodium percarbonate:

5% sodium metaborate + 5% polyethylene glycol (PEG, MW = 6000)
5% sodium metaborate + 5% sodium carbonate
5% sodium metaborate + 0.5% disodium ethylenediaminetetraacetate (EDTA)
5% sodium metaborate + 0.5% EDTA · di (triethanolamine) salt and
5% sodium metaborate + 0.5% trisodium nitrilotriacetate (NTA).

The above five samples and an uncoated sodium percarbonate sample Be even in a bleach of the following compositions 3-1 and 3-2. The mixtures are then in terms of Stability in the same way as in Example 21 was examined. The results are in Table 22 summarized.

The results of Table 22 show that the Samples have a very good storage stability, especially when sodium metaborate is used in Mixture with an organic high molecular compound, z. PEG or a sequestering agent, e.g. B. EDTA or NTA, provided they are the storage-stable prepared according to the invention Sodium percarbonate included.

Example 24

20 kg of moist sodium percarbonate are placed in a centrifugal diffusion mixer given. The mixture is with sprayed with a coating agent with stirring. The Total mixing time is 10 min. After that, the coated was Sodium percarbonate taken out and with warm air dried. The coating mixture has the following Composition:

5% sodium metaborate + 0.5% EDTA · 2 TEA
4.54% Borax + 0.5% EDTA · 2 TEA and
2.4% boric acid + 0.5% EDTA · 2 TEA

The above three samples and an uncoated sodium percarbonate control and uncoated Sodium percarbonate is evenly mixed in a bleach with the following composition 4-1 and 4-2 incorporated. The mixtures thus prepared are then in terms of storage stability examined as in Example 21. The results are summarized in Table 23.  

The results of Table 23 show that the coating of sodium percarbonate to a greater extent as in Examples 21 to 23 is made and that the Samples 1 and 2 a storage stability which is considerably better than that of the comparative samples 3 and 4.

Example 25

The coated sodium percarbonate according to Example 24 becomes the following enzyme-containing bleaching agents 1 and 2 added. The resulting mixtures are with regard to storage stability after storage examined at 50 ° C for 20 days. The results are in Table 24 summarized.

Samples 1 and 2 of Table 24 are the inventively prepared storage stable sodium percarbonate containing samples, while samples 3 and 4 of Table 24 are comparative samples. The results from Table 24 show that samples 1 and 2 are superior to Comparative Samples 3 and 4 in terms of storage stability and enzyme stability. The Stability of the enzyme is improved especially in the samples, which contains the bleaching mixture (2) with zeolite.

Example 26 Preparation of coated sodium percarbonate

The additives for the coating compositions become so prepared such that 0.2 parts by weight of boron atoms per 100 parts by weight Sodium percarbonate present.

TEST 1:
Drying temperature is higher than the melting point of sodium borate.
1000 g (13.7% oxygen provided) of dried sodium percarbonate are charged in a centrifugal diffusion type mixer.
A 25% aqueous solution of 25 g of sodium metaborate tetrahydrate (NaBO₂ · 4 H₂O, 57 ° C melting point) is sprayed with stirring for 30 seconds. After stirring, the mixture is dried for 10 minutes at a temperature of 100 ° C in a fluidized bed dryer to obtain a composition of the present invention (provided oxygen: 13.6%, moisture content: less than 0.5%).

TEST 2:
Drying temperature is lower than the melting point of sodium borate.
This test is carried out in the same manner as TEST 1, except that the mixture is dried at 40 ° C for 30 minutes to obtain another composition according to the invention (oxygen provided: 13.6%, moisture content : less than 0.5%)

Storage stability test of coated sodium percarbonate

Each 10 parts by weight of the prepared according to the above test Sodium percarbonate and 90 parts by weight of those shown in Table 1 phosphorus-free powder detergent composition be mixed. Each 10 g of the mixtures are in a 50 cc given a plastic container. The vessels are closed and allowed to stand at 40 ° C and 80% RH for 14 days. Subsequently is the oxygen provided by means of Measured potassium permanganate titration. The results are in Table 2 is shown.

A coated sodium percarbonate according to the invention shows even then excellent stability when the drying temperature lower than the melting point of the sodium borate lies. Table 2 shows that the excellent Results of the invention are not only available if the Drying temperature higher than the melting point of sodium borate but also when the drying temperature is lower as the melting point of sodium borate.

component Wt .-% Sodium alkylbenzenesulfonate (C = 12 to 16) 25 Sodium alkyl sulfate (C = 12 to 16) 3 Synthetic alcohol ethoxylate (C = 12, 7 moles EO average) 2 4A-type zeolite 40 sodium 5 sodium 15 sodium sulphate rest Polyethylene glycol (average molecular weight: 13,000) 1 fluorescent dye 0.1 Enzyme (protease) 1 water 5

Provided oxygen residue (%) 14 days later TEST 1 (dried at 100 ° C for 10 min) | 76.1% TEST 2 (dried at 40 ° C for 30 min) 73.9% Comparative composition [dried PC (uncoated)] 32.4%

Example 27 Experimental report I

In the following examples, the amounts of boron used were in Coating the same, based on 100 parts by weight Sodium percarbonate (Bormenge = 0.20 parts by weight).

example 1

A centrifugal diffusion type mixing device (Lödige Mixing device) was water wetted with sodium percarbonate (3374 g) (water content 11.2%) loaded. As a coating agent sodium metaborate tetrahydrate (NaBO 2 .4H 2 O, 76.4 g) was added, while stirring and mixing for 3 minutes. Subsequently the coated sodium percarbonate was removed and added to a batch-type fluidized bed dryer and at Dried at 100 ° C for 10 minutes.

Example 2

It was prepared in the same way as described in Example 1, prepared a coated sodium percarbonate, with the exception that boric acid (36.2 g) was used as the coating agent were.  

Example 3

Dried sodium percarbonate (1000 g) was added to a fluid bed dryer of the batch type added. A boric acid solution (H₃BO₃ 11.4 g, water: 57 ml, heated and dissolved at 80 ° C) was sprayed on, fluidized and dried at 100 ° C for 5 minutes.

Example 4

Dry sodium percarbonate (1000 g) was added to a fluid bed dryer of the batch type added. Subsequently were 100 g of dioctyl phthalate sprayed on and fluidized. Then it became Sodium perborate tetrahydrate (NaBO₃ · 4 H₂O, 28.5 g, with a 100 Mesh screen sieved) added.

Shelf life studies for the coated sodium percarbonate

The coated sodium percarbonate (10 parts by weight) was washed with a phosphorus-free detergent (zeolite builder) (90 parts by weight) mixed to obtain the following composition.

Phosphate-free bleach detergent Wt .-% sodium dodecyl benzene sulfonate 25.0 Synthetic zeolite (type 4A) 30.0 Sodium silicate (JIS No. 2) 5.0 sodium 15.0 fluorescent dye 0.5 Sodium polyacrylate (MW = 10,000) 1.0 Enzyme (API-21, Showa Denko) 0.3 Sodium percarbonate (coated) 10.0 water 5.0 sodium sulphate rest total 100

Subsequently, a 50 cc plastic vessel with 10 g the mixture described above. The vessels were sealed and allowed to stand at 40 ° C, 80% RH for 14 days. Subsequently, the oxygen radical provided was added measured by a titration method with 0.1 N potassium permanganate solution, the process being the same way as described in Example 3 of the patent application performed has been.

Results: Provided oxygen radical (%) 1. wetted PC + powder coating (NaBO₂ · 4 H₂O, 2.55 wt .-% / PC) 54.4 2. wetted PC + powder coating agent (H₃BO₃ · 1.14 wt.% / PC) 48.8 3. Dry PC + coating agent solution (sprayed in a fluidized bed) (H₃BO₃ · 1.14 wt .-% / PC) 38.0 4. Dry PC + PB + hydrophobic organic substance (NaBO₃ · 4 H₂O, 2.85 wt .-% / PC) 37.1 Comparison: dry PC (uncoated) 16.7

In Examples (1) and (2), the coated sodium percarbonates became in the same manner as in Example 1 of the patent application prepared to the coating agent Sodium borate on the one hand and boric acid on the other hand. From the results it is clear that the by Sodium borate caused stabilizing effect is higher than that boric acid effect.

Example (3)

The coated sodium percarbonate was submerged Use of boric acid as a coating agent on the same Way, as in the examples of citation 1  (DE-OS 28 00 916) described, prepared. The stabilizing effect is essential compared to the effect of sodium borate deteriorated.

Example (4)

The coated sodium percarbonate was submerged Use of sodium perborate as a coating agent on the same way as in example 1 of the citation 5 (DE-OS 24 58 326) described, prepared. Again, this is the Stabilizing effect compared to sodium borate as a coating agent significantly worsened.

Claims (9)

1. Storage stable sodium percarbonate, obtainable by that on the surface of sodium percarbonate, a sodium borate containing layer is present, with water present is, and then the product at a temperature of not higher than 160 ° C dries. 2. Storage stable sodium percarbonate according to claim 1, characterized obtainable by adding a sodium borate containing water of crystallization used. 3. Storage stable sodium percarbonate according to claim 1, characterized available, that is wetted with water sodium percarbonate used, with the water in an amount of 7 to 18 Wt .-%, based on the sodium percarbonate, is present, and then add the sodium borate powder for the coating. 4. Storage-stable sodium percarbonate according to one of claims 1 to 3, obtainable by adding 0.1 to 30% by weight of coating agent, based on the sodium percarbonate, and From 10 to 100% by weight of sodium borate, based on the coating agent, starts. 5. Storage-stable sodium percarbonate according to one of claims 1 to 4, obtainable by using a coating agent used a sodium borate in an amount of 0.04 to 10 wt .-% boron, based on the sodium percarbonate, contains.   6. Storage-stable sodium percarbonate according to one of claims 1 to 5, obtainable by using a coating agent which further comprises an alkali metal silicate or a Contains magnesium compound. 7. Storage-stable sodium percarbonate according to any one of claims 1 to 6, obtainable by using a coating agent which continues to be a metal sequestering agent contains. 8. Storage-stable sodium percarbonate according to any one of claims 1 to 7, obtainable by applying to the surface of Sodium percarbonate a sodium borate containing layer Apply, with water present, and then a temperature treatment is carried out at a temperature which is not below the melting temperature of the borate. 9. Process for the preparation of storage-stable sodium percarbonate, characterized in that on the surface of Sodium percarbonate a sodium borate containing layer with water present, and the product then dried at a temperature of not higher than 160 ° C.