MXPA99005525A - Method to produce sodium percarbonate - Google Patents

Abstract

The invention relates to a novel method for the"dry"production of sodium percarbonate (dry process). Monohydrate crystal is reacted with a quasi-stoichiometric quantity of concentrated aqueous hydrogen peroxide solution, in relation to the quantity of active oxygen required in the sodium percarbonate. This method can be combined to great advantage with the subsequent compaction of the sodium percarbonate obtained. Sodium percarbonate products containing varying concentrations of active oxygen of at least 10 weight percent, but in particular with high active oxygen concentrations of above 14.5 weight percent, can be produced. The resulting sodium percarbonate products are characterized in that they have remarkably advantageous characteristic as regards dissolution rate, stability and compatibility with detergent base, and are superior to conventional sodium percarbonates obtained, for example, by a crystallisation process. The invention also relates to said percarbonate sodium products and detergent compounds containing same.

Description

Procedure for the preparation of sodium percarbonate Description The present invention relates to a process for preparing sodium percarbonate (hereinafter also abbreviated as "PCS") and having active oxygen concentrations of at least 10% by weight, particularly > 14.5 and up to 15.2% by weight, as well as the sodium percarbonate itself and to bleaching and washing compositions containing this novel sodium percarbonate. Sodium percarbonate is used as a whitening component in pulverulent cleaning, bleaching and washing compositions, and is distinguished by good water solubility as well as by a rapid release of hydrogen peroxide, and is also an ecological product whose decomposition products do not they affect the environment. In the literature, for the sodium percarbonate, the overall formula Na 2 CO 3, 5 H 2 O 2 is indicated with a theoretical concentration of active oxygen of 15.28% by weight. However, it is necessary to take into account that industrial sodium percarbonate prepared from hydrogen peroxide and sodium carbonate is generally not a well-defined homogeneous compound of this type, but on the one hand it is a mixture of compounds that have different hydration water proportions, of the formulas Na2C03.l, 5 H202 Na2C03.1.5 H202. H20 Na2C03.2 H202. H20 Na2C03.2 H202 Na2C03. H202 and on the other hand and according to its preparation process, it also contains a certain proportion of non-oxidized sodium carbonate (soda) as well as other components coming from the manufacture, such as, for example, sodium sulfate or sodium chloride. Both the preparation conditions and also the respective additives influence the properties of the product not only with regard to stability but also with regard, for example, to the concentration of active oxygen, the solubility and the apparent specific gravity or granulometry of the product. sodium percarbonate. Thus, for example, the concentration of active oxygen that can be reached in industrial sodium percarbonate reaches, in the best case, 13.4 to 14.5% by weight, but is conditioned by additives resulting from the preparation (sulphate, sodium chloride) and because of the stabilizing resources it is often much lower. The inherently good solubility of sodium percarbonate is also often lowered, for example by the presence of other salts such as sodium carbonate, sodium sulfate and sodium chloride from the preparation. In addition, the apparent specific gravity or granulometry that can be obtained in sodium percarbonate with the preparation methods of the state of the art is generally only slightly variable and in most cases is limited from the start to narrow intervals by the type of preparation or the soda (sodium carbonate) used. However, there is an increasing desire to obtain sodium percarbonates with a high concentration of active oxygen and different apparent specific grains or granulometries, according to the different requirements of the manufacturers of washing compositions, for example to be used in light powders. for washing of low apparent specific gravity or in compact washing compositions with high apparent specific gravity of the components of the compositions for washing, bleaching and cleaning. In particular, it is also necessary to adapt the apparent specific weights of the various components of those compositions to each other to avoid as much as possible the demixing that would necessarily occur with different apparent specific weights of the components. For the preparation of sodium percarbonate, three technologies are known in the current state of the art: crystallization process, atomization process and dry process. Generally the sodium percarbonate is prepared by the crystallization process. For this, a solution or suspension of sodium carbonate is reacted with hydrogen peroxide at a temperature of 10 to 20 ° C and crystallized in the presence of crystallizers such as, for example, water glass, organic or inorganic phosphonic acids, etc. However, due to the good solubility of sodium percarbonate it is necessary to precipitate by saline saturation of the reaction mixture to increase the yield in sodium percarbonate, for which, according to the state of the art, sodium chloride is preferably incorporated in the a concentration of approximately 240 g / 1 in the reaction mixture. However, it is difficult to control the crystallization so that for the formation of a good crystalline configuration it is advisable to add the so-called crystallization enhancers such as polyphosphates or polyacrylates. Then, the crystallized sodium percarbonate is separated by centrifugation and dried by conventional procedures, for example in a fluidized bed. However, the PCS obtained by the crystallization process is not optimal for many applications, and in particular its properties are often affected by the concentration of sodium chloride required by virtue of the preparation process. In the spray process for the preparation of sodium carbonate it is not necessary to filter or centrifuge to separate the sodium percarbonate from the mother liquor. In contrast, in this atomization process, an aqueous solution (or, if necessary, also a slightly concentrated suspension) of sodium carbonate and hydrogen peroxide is dried in a spray dryer. However, spray drying products generally have a very low apparent specific weight of only 0.35 kg / 1 and therefore washing compositions which increasingly contain granular components with specific densities are not usable for the current formulations. In addition, by atomizing solutions it is necessary to remove a lot of water, which requires an important input of energy. As a modification of the atomization process, solutions of sodium carbonate and hydrogen peroxide are sprayed continuously on a bed for example fluidized with hot air constituted by previously prepared sodium percarbonate The atomization and drying step can be carried out alternately in one or two stages In another variant of the atomization process solutions of sodium carbonate and hydrogen peroxide are injected through of separate nozzles in a reaction chamber, making simultaneously pass through the reaction chamber a hot mixture of air and carbon dioxide. However, by this process an extremely porous sodium percarbonate is obtained which, with respect to apparent specific gravity and abrasion resistance, does not meet the current specifications of washing compositions. In the so-called dry process, the sodium percarbonate is prepared by reacting Na2CO3 free of water of hydration with a concentrated solution of hydrogen peroxide at 50 to 80% by weight, already evaporating during the reaction the small amounts of water produced . In this process, substantially all of the reaction is worked with a substantially dry reaction mixture. The process can be carried out, for example, in mixers, in fluidized-bed reactors or also in tubular reactors with an injection device for H202. Apart from the long reaction times, this process suffers from the drawback that there is no purification of the sodium carbonate thus prepared, so that it is necessary to adopt additional resources for the stabilization of the product, for example the addition of special stabilizers already during the reaction . A particularly serious drawback is that it is necessary to use a large excess of hydrogen peroxide to obtain a PCS with a sufficient concentration of active oxygen. In addition, this procedure offers few possibilities of variation with regard to the properties of the granulate of sodium percarbonate, for example with regard to apparent specific gravity and granulometry, because the configuration of the granulate of sodium percarbonate corresponds essentially to the shape of the granulate of the soda used as raw material (without taking into account small rounds resulting from the reaction). Particularly, in the preparation of high density bulk sodium percarbonate granules for compact washing compositions it is necessary to use heavy soda, but having only a small surface area for the reaction with hydrogen peroxide. Therefore the reaction is incomplete so that only low concentrations of active oxygen are obtained as well as heterogeneous products with a higher proportion of soda and heterogeneously distributed whose alkalinity affects the stability of the product. The present invention has the purpose of obviating the drawbacks of the state of the art with regard to the preparation of sodium percarbonate and proposing an efficient process capable of being carried out with high flexibility for the dry preparation (dry process) of sodium percarbonate with good properties. The dry process proposed in the present invention makes it possible in particular to obtain, with the most efficient possible yield of active oxygen, a high quality sodium percarbonate with variable but particularly high concentrations of active oxygen and with variable parameters of the granulate according to the intended use . This purpose is fulfilled by the process of preparation of sodium percarbonate of the present invention defined in the claims, as well as by the novel sodium percarbonate of unpredictably good properties and the solid bleaching and washing compositions also defined in the claims. The process of the present invention for the dry preparation of sodium percarbonate with an active oxygen concentration of at least 10% by weight is characterized in that solid sodium carbonate monohydrate is reacted with an almost stoichiometric amount, with reference to to the desired concentration of active oxygen in sodium percarbonate, of a 50-70% aqueous solution of hydrogen peroxide, at reaction temperatures up to a maximum of 80 ° C, in a mixing device to obtain a paste-like mass of percarbonate of moist sodium, then obtaining by drying and / or granulation a sodium percarbonate with an active oxygen concentration of 10 to 15.2% by weight, preferably >14.5 and up to 15.2% by weight, and with the desired particle parameters, such as apparent specific gravity and average granulometry. The carrying out of the process of the present invention can take place in any mixer that allows a sufficiently fast and intense intermixing of solid substance (particularly of sodium carbonate monohydrate and PCS formed) and of hydrogen peroxide used as raw materials. Suitable, for example, are the following mixers: mixing boilers provided with types of agitator tools suitable for fluids, for example propeller, disk, sheet, crossbar or grid agitators. High-intensity mixers are very efficient, for example turbo-mixers and high-speed rotor and stator mixers which can additionally be provided with a blade head for shredding larger agglomerates. Under the definition of rapid or intense intermixing is meant any mixing intensity corresponding to an initial speed of the mixing device of at least 100 rpm, particularly about 100 to 150 rpm. Preferred mixers are those that are equipped with kneading tools that can work in a particularly homogeneous way the doughy masses that are formed in the reaction. The reaction can be carried out continuously or discontinuously. The feed of solid sodium carbonate monohydrate to the mixer is conveniently carried out by means of a metering auger if the reaction takes place continuously. In the case of a batch reaction, the sodium carbonate monohydrate is first placed in the mixer. The aqueous solution of hydrogen peroxide is added in both cases, ie with continuous or discontinuous work, preferably through a nozzle, particularly a two-component nozzle, in the amount necessary to add it to the mixer, and in the continuous technique the The rate of addition of the hydrogen peroxide is adapted to the addition of sodium carbonate monohydrate, the residence time of the reaction mixture in the mixer and the amount of PCS formed continuously extracted, by time interval. For the temperature control of the exothermic reaction between the sodium carbonate monohydrate and the hydrogen peroxide, the mixer used can be provided with cooling devices. This is particularly convenient for dissipating the heat of reaction and maintaining the concentration of active oxygen in the hydrogen peroxide and in the sodium percarbonate in formation. For the cooling that can take place conveniently through a simple chiller jacket, the cooling capacity of running water is generally sufficient, so that for cooling it is generally not necessary to dissipate an additional amount of energy. During the reaction the reaction temperature can easily reach up to 80 ° C without affecting the properties of the product, particularly the concentration of active oxygen. The temperature control during the reaction does not present problems and the reaction can also be carried out above 20 ° C without affecting the product, which allows a "fast work", ie a relatively rapid intermixing of sodium carbonate monohydrate and hydrogen peroxide, however, temperatures higher than 80 ° C should be avoided as much as possible, otherwise the active oxygen y will be affected by the premature decomposition of hydrogen peroxide, the reaction temperatures during the exothermic reaction will be Conveniently they range from room temperature to a maximum of 80 ° C, preferably in the range from above 20 ° C to a maximum of 80 ° C. An essential characteristic of the method according to the present invention is that it is used as raw material sodium carbonate monohydrate, ie a particular form of sodium carbonate, with an essentially defined concentration of water of hydration. Conveniently, sodium carbonate monohydrate is obtained by conditioning soda (Na 2 CO 3), ie by reacting the anhydrous form of the soda with 1 to 1.5 mole of water. For this purpose, preferably preheated sodium carbonate (for example, water bath temperature up to 100 ° C) is reacted with the calculated amount of boiling water in a blender for a sufficient time interval, and then the formation reaction is analytically monitored of the sodium carbonate monohydrate in conventional manner, for example by DSC analysis and titration of the total alkalinity. The conditioning of the soda to form monohydrate to be used in the process of the present invention is independent of the type of the soda to be conditioned. For example, both super light soda with apparent specific weights less than 0.50 kg / 1, for example 0.20 kg / 1 to 0.48 g / 1, lightly calcined soda with an apparent specific gravity of for example 0 , 50 to 0.55 kg / 1 and heavy calcined soda with an apparent specific gravity of 1.0 to 1.1 kg / 1. The process of the present invention proceeds particularly conveniently using sodium carbonate monohydrate which has been obtained by conditioning light forms of soda, for example particularly light soda with apparent specific gravity of about 0.50 to 0.55 kg / 1, or also of superlivine soda with an apparent specific weight less than 0.50 kg / 1. These light forms of soda can be processed after conditioning to obtain sodium carbonate monohydrate, with an almost total reaction with hydrogen peroxide to obtain a particularly homogeneous sodium percarbonate. The use of sodium carbonate monohydrate from light forms of soda allows a rapid and complete reaction with H202, which is completed within a few minutes to a maximum of approximately 1.5 hours, in particular already within the term of one hour, according to the amount to react. As illustrated in the exemplary embodiments, for example, quantities of the order of a kilogram can be reacted within minutes by conventional cooling with water. Thus, for example, 2 kg of light soda monohydrate can be fully reacted in less than about 15 minutes by cooling with water. However, even when using calcined heavy soda for conditioning to form the monohydrate, short reaction times in the subsequent reaction with hydrogen peroxide are possible to obtain substantially homogeneous particles of PCS if the conditioning time is eventually lengthened for sufficient impregnation. the soda particles with the water prepared for hydration, or optionally alternatively or additionally a slight excess of water is added for hydration. The control of the characteristic of sodium carbonate monohydrate is carried out as in the conditioning of light soda by DCS analysis or titration of total alkalinity.

The ratio of sodium carbonate monohydrate to active oxygen concentration in the hydrogen peroxide is controlled in the process of the present invention in such a way that the molar ratios correspond to the concentration of active oxygen to be achieved in the PCS, being necessary eventually only a small excess of hydrogen peroxide of the order of magnitude up to about 5%. As the process of the present invention ensures a substantially total yield of active oxygen, it is therefore sufficient to use an almost stoichiometric amount of H202 (relative to sodium percarbonate with the theoretical global formula Na2C03.1.5 H202; active oxygen = 15.28% by weight) and costly excesses of H202 can be avoided. With molar ratios of H202 to sodium carbonate monohydrate of about 1.0, sodium percarbonate with active oxygen concentrations of about 10% by weight is obtained. In a preferred embodiment of the invention, the molar ratio of H202 to soda is regulated to approximately 1.5 to 1.52, so that an active oxygen concentration in sodium percarbonate of about 14% by weight is obtained, particularly mind > 14.5 to 15.2% by weight. The concentration of aqueous hydrogen peroxide used in the process of the present invention is 50 to 70% by weight, however concentrations of 55 to 65% by weight are preferred. Generally hydrogen peroxide is stabilized in conventional manner and all active oxygen stabilizers of the state of the art are suitable, for example, among others, the product known under the name Turpinal SL.

The drying and granulation of the reaction product of soda monohydrate and H202 can take place by conventional methods and can be controlled according to the procedure and device used to obtain a sodium percarbonate with the desired granulometry (= mean diameter of the granules) of about 150 to about 1300 μm. In a preferred embodiment of the present invention, in particular sodium percarbonatps with granulometries of 350 to 1300 μm are prepared. The process of the present invention therefore makes it possible to prepare sodium percarbonate with granulometric ranges for light washing compositions or for compact washing compositions with granulometries from about 550 to 600 μm, particularly 640 to 1100 μm, and preferably with granulometries of about 800 at 1000 μm. The granulation conditions that must be maintained for this purpose are not critical and correspond to the usual conditions of the granulation devices used in each case. By the process of the present invention, therefore, sodium percarbonate with an apparent specific gravity of from 0.2 kg / 1 to 0.1 kg / 1, preferably 0.5 to 1.1 kg / 1 can be obtained. Other particularly preferred particle sizes and specific weights are described below in relation to the PCS products according to the invention. The drying and granulation step can be carried out, for example, in a turbulence dryer (granulator dryer), as well as in other rapid drying or granulation devices under the usual conditions. Thus, for example, drying may also take place in fluidized bed or circulating air dryers. The granulation can take place in all the variants of the process of the invention in a conventional manner, for example by dry-phase granulation in a compaction or wet-phase granulation process (cumulative granulation) in granulating mixers such as, for example, grate mixers. of plow or mixers V. In a combined embodiment of the granulation and drying step, the process comprises working in a turbo-dryer, which in principle is a turbo-mixer equipped with a heating device. The work in the turbo-dryer is particularly recommended for continuous procedures, in which the reaction mass or paste is dried immediately after the reaction and simultaneously granulated. Alternatively, the granulation can take place after mixing the raw materials in an extrusion process. In the granulation and drying step, granulation aids (such as silicates) and stabilizers (such as organic phosphonic acids or phosphonates) can be added if desired, which in the PCS prepared according to the present invention generally, but not necessarily, are required. In a particularly preferred embodiment of the invention, the process is distinguished by the fact that the sodium percarbonate obtained after drying (for example in this variant of the invention by drying by circulating air) is subjected to a subsequent granulation compaction. This method of preparing a sodium percarbonate product is distinguished by the fact that in a first stage (= reaction stage) a sodium percarbonate is prepared by the reaction procedure described above and dried, and in a second stage (= stage of compacting and granulation by dry route) the sodium percarbonate obtained after drying in the first stage, if desired with addition of up to 1% of a lubricant, preferably an alkali metal stearate - and / or alkaline earth, it is compacted in the form of shells that later, by means of a granulation by dry way by crushing and sieving, it is transformed into a granulate of sodium percarbonate with the desired particle parameters such as apparent specific gravity and average diameter of the granules. According to this variant of the process of the present invention, primary particles which are substantially dry are subjected to a pressing process (compaction) and are densified by the action of the applied pressing pressure. In this way, the desired agglomeration of the primary particles used is produced. As the agglomeration takes place by pressing, that is to say by the application of a pressure, the densification process by pressing is also called compaction or agglomeration by pressing or by pressing, or in the case of the preparation of the granulate as granulation by pressing or by pressure. The process of agglomeration by pressing for the preparation of agglomerates or granulates must therefore be distinguished from the process of agglomeration by accumulation (process of granulation by accumulation) in which the adherence of the particles is carried out without substantial influence of the pressure and exclusively by adhesion with liquid (for example water) and / or a binder. The temperature range within which the compaction can be carried out corresponds to the temperature range which ensures a good thermal stability of the active oxygen-containing compositions used and the process can be carried out without problems under the safety aspects. The compaction of the sodium percarbonate particles takes place, for example, in a convenient embodiment of the present invention at room temperature. This process can be carried out without problems in this temperature range with respect to the concentration of active oxygen of the primary particles of sodium percarbonate to be pressed. In the PCS prepared according to the present invention no losses of active oxygen have been observed that could affect the product contrary to the conventional crystallization processes of the state of the art in conventional PCS. The magnitude of the pressure to be applied can vary within wide limits and can therefore be adapted to particular wishes and requirements as regards the product. However, downward pressure is limited by two premises. On the one hand, the minimum pressure to be applied must be sufficient to give the agglomerate of primary particles a mechanical resistance and sufficient apparent specific weight. The minimum pressure to be applied in order to obtain the desired properties depends on the type of presses used and the properties of adhesion of the product and can be easily determined in some preliminary tests with regard to the desired processing and product properties. The upper limit of the pressure to be applied is determined by the admissible or maximum pressure technically achievable in the equipment used for compaction and the adhesion properties of the product. According to an example of the inventionIn a cylinder press, for example, the primary amorphous particles of sodium percarbonate are densified by pressing at pressures of at least 50 bar to a maximum of 150 bar. Preferably it is densified at pressures of 80 to 120 bar. Compared to the fine mounds of primary particles of PCS, the agglomerates obtained according to the invention are shaped products that after scoring and screening have less tendency to dust, adhesion, agglutination and demixing, which can be transported and properly dosed, which have good creep and a specific apparent weight defined. By the process of the present invention the properties of the product, such as shape and size of the granulate as well as apparent specific weight of the PCS, can be adapted to the requirements of various application purposes or other market requirements. The desired properties of the product determine in a defined way the most convenient compaction process in each case. For compaction, all conventional pressing agglomeration devices can be used. While it is possible to agglomerate the primary particles in wet state by pressing, optionally with the addition of small quantities of liquid, binder, lubricant, other auxiliaries and / or desired or desirable additives, preferably the advantages of the present invention arise fully when using compaction in which only dried primary particles are pressed, because in this process the stability of the product can not be negatively affected (in particular the stability of active oxygen) by existing or added liquids (particularly water) and a subsequent drying is not required. the compaction. Another advantage arises from the fact that, if desired, binders, lubricants and / or other auxiliaries can be added in the agglomeration process by dry pressing, these are not strictly necessary for carrying out the process and undesirable modifications of the process can be avoided. properties in the pressed percarbonate that may eventually arise from these auxiliary and additional substances. On the other hand, it is also possible to homogeneously mix the agglomerates with additives which are conveniently modified, for example up to 1% by weight of sodium stearate or magnesium stearate, with the crystalline particles of percarbonate before pressing agglomeration. Suitable compaction devices are, for example, cylinder presses, such as smooth cylinders, structured cylinders or shaped cylinders (briquetting cylinders). These devices can be operated with, or possibly also without, forced feeding devices for the primary particles to be pressed. According to the compaction device used, the primary particles are pressed in defined forms, for example in dense, smooth or structured plates, ie the so-called shells. The husks are then crushed to give the granulate of the desired dimensions. Cylinder presses, preferably structured cylinders, are used in a particularly convenient embodiment of the compaction process. The structured cylinders are cylinders profiled, fluted or continuously profiled, for the generation of smooth or profiled plates (shells), tapes or compacted bodies. In the case of structured cylinders, more or less profiled cylinders can be used, the latter in open or closed configuration. In this way, more or less smooth, or more or less structured (for example, wafer-shaped) corrugated plates are obtained, or in the case of cylinders uniformly shaped over the entire width of the cylinder, rods are also obtained. As the products obtained by the compaction do not yet have the desired shape of the product, for example shells, corrugated plates or rods, these they are crushed by conventional processes to give granulates of the desired granulometry and bulk density. For crushing, shredders can be used for coarse graining or granulating sieves for fine graining. The sodium percarbonate granules prepared by the process of the present invention can optionally be provided in conventional manner with coatings. Suitable coating materials are, for example, those described in the state of the art., such as, for example, borates, salts, such as Na 2 CO 3, NaCl, Na 2 SO 4 and mixtures thereof, organic coatings, such as, for example, lactobionic acid and its derivatives. If an additional coating of the sodium percarbonate granules prepared according to the present invention is desired, the coating process can conveniently and conventionally follow the granulation step.

The invention also relates to novel sodium percarbonates distinguished by valuable properties that until now could not be obtained with the processes of the state of the art. The sodium percarbonate according to the invention is distinguished by an active oxygen concentration > 14.5 to 15.2% calculated without the granulation aids or coating materials optionally added. In a variant, this novel PCS is distinguished by a dissolution rate of at least 95% after 1 minute and at least 99% after 2 minutes (standard conditions being 2 g, 15 ° C). In another variant, the novel PCS is distinguished by an exothermic DSC peak greater than about 155 ° C, preferably greater than or equal to 159 ° C, particularly in the range of 159 to 162 ° C. In another variant, the novel PCS is distinguished because it has a stability loss lower than 6.2% and preferably 3.4 to 5.1%, measured under standard conditions 105 ° C, 2h. The innovative PCS products present a number of other convenient properties. The sodium percarbonate has in particular an average granule diameter of 550 to 1100 μm, preferably 640 to 1000 μm. The apparent specific gravity of sodium percarbonate is preferably 0.85 to 1.1 kg / 1. In addition, sodium percarbonate has a convenient abrasion index of less than 5% (measured under standard conditions). In a variant of the invention, sodium percarbonate is distinguished in that it contains up to 1% by weight of a lubricant selected from the group comprising alkali metal or alkaline earth metal stearates introduced during granulation and has an apparent specific gravity of 0.93 to 1. , 1 kg / 1. This sodium percarbonate has an abrasion index of less than 8% (measured under standard conditions). The novel sodium percarbonates can be prepared by the process according to the invention described above, in particular by the process variant with compaction and dry granulation. If the sodium percarbonate according to the convenient variant of the process is prepared with compaction and dry granulation, the compaction may optionally be carried out with or without the addition of lubricants. If the sodium percarbonate is prepared by the convenient process variant with compacting and dry granulation without adding lubricants during compaction and dry granulation, it is distinguished in a variant by a loss of stability lower than 6.2% under standard conditions (105 ° C, 2h). In another variant, the sodium percarbonate obtained in the dry compaction / granulation without the addition of lubricants has an average granule diameter of 550 to 1100 μm, preferably 640 to 1000 μm. In another variant, the sodium percarbonate which is obtained in the process without the addition of lubricants during dry compaction / granulation has an apparent specific gravity of 0.85 to 1.1 kg / 1. Sodium is further distinguished by an abrasion index of less than 5% (standard conditions) In another variant of the invention, the preparation of sodium percarbonate is carried out according to the process variant by compacting and granulating by dry route and with the addition of lubricant. During the compaction, the sodium percarbonate thus obtained is distinguished in a variant of the invention because it is obtained with the addition of up to 1% by weight of a lubricant during the dry compaction / granulation, preferably with the addition of metal stearate. alkaline or alkaline earth, having an active oxygen concentration greater than 14.5% by weight, preferably greater than 14.8% by weight and a loss of maximum stability of 1 2.0 (measured under standard conditions 105 ° C, 2 h). In another variant of the invention, the sodium percarbonate obtained with the addition of up to 1% of a lubricant during compaction / granulation by dry route, preferably with the addition of alkali metal or alkaline earth stearate, it is distinguished because it has an active oxygen concentration greater than 14.5% by weight up to 15% by weight, preferably higher than 14.8% by weight up to 15.0% by weight, and an average granulometry of 800 to 1000 μm . In another variant of the invention, the sodium percarbonate obtained with the addition of up to 1% by weight of a lubricant during the dry compaction / granulation, preferably with the addition of alkali metal or alkaline earth metal stearate, has an oxygen concentration active greater than 14.5% by weight up to 15% by weight, preferably greater than 14.8% by weight up to 15.0% by weight, and an apparent specific weight of 0.95 to 1.1 kg / 1. This sodium percarbonate has a convenient abrasion index of at most 8% (measured under standard conditions). The novel PCS products obtained according to the present invention are excellent for being used in solid washing and bleaching compositions. The invention therefore also relates to solid bleaching and washing compositions containing 0.5 to 40% by weight, preferably 5 to 25% by weight, of the sodium percarbonate according to the invention, and 99.5 to 60% by weight. weight, preferably 95 to 75% by weight, of formulating auxiliaries and excipients customary in washing and bleaching compositions, chosen from the group comprising surfactants, builders, bleach activators, peracid bleach precursors, enzymes, enzyme stabilizers, carriers of dirt and / or compatibilizers, complex before and chelators, foam regulators and additives such as optical brighteners, opacifiers, corrosion inhibitors, anti-electrostatic, dyes, bactericides. Due to the excellent stability of the sodium percarbonate according to the invention against the components of washing compositions, it is particularly suitable for bleaching and washing compositions containing the sodium percarbonate in the presence of builders such as zeolites. The specific granulometries and specific weights of the sodium percarbonate according to the invention conveniently allow the use in compact washing compositions. A wide selection of zeolite builders can be used in the compositions according to the present invention which alternatively are also referred to as aluminum silicate builders. Suitable zeolites generally have a substantial ion exchange capacity of calcium ions or alkaline earth metal (removal of water hardness). The ion exchange capacity is expressed in calcium carbonate equivalents and is at least 150 mg CaCO3 per gram, and for preferred zeolites the ion exchange capacity is 200 to 250 mg CaC03 equivalent per gram. Zeolites are generally described by their general empirical formula MZ [A102) Z (SiO2) and]. x H20, where M represents an alkali metal, preferably sodium, "z" and "y" are integers of at least 6 with a molar ratio of y: z from 1: 1 to 2: 1 and "x" is a number whole of at least 5 and preferably about 10 to 280. Many zeolites are hydrated and contain up to about 30% water, of which up to 10 to 25% by weight may be bound in the zeolite. The zeolites may be amorphous but most of the preferred zeolites have a crystal structure. Although certain aluminum silicates are of natural origin, most are synthetic. Suitable crystalline zeolites with known structure and formula are, for example, zeolite A, zeolite X, zeolite B, zeolite P, zeolite Y, zeolite HS and zeolite MAP. The amount of zeolite in the bleaching and washing compositions according to the invention is at least 5% by weight, and in many cases at least 10% by weight, relative to the entire composition. Generally the amount of zeolite is not more than about 60% by weight, and often not more than 50% by weight. In particular, the proportion of zeolite in the composition is not greater than 40% by weight relative to the total composition. Although in a preferred embodiment of the invention the sodium percarbonates according to the present invention are described for those washing and bleaching compositions which as a builder may contain one or more zeolites, the bleaching and washing compositions in a general embodiment of the present invention may also contain the sodium percarbonate according to the present invention together with amorphous zeolites or also with layered zeolites within the ranges of weight proportions indicated .. Suitable layered silicates, particularly of crystalline nature, frequently respond to the formula Na2Si ? 02? +1. And H20 or the corresponding compounds in which a sodium ion is replaced by a hydrogen ion X varies particularly in the range of 1.9 to 4 e "y" from 0 to 20. The layered silicates can be used both in mixtures with zeolite builders and also without zeolite builders in the composition it is washing and bleaching. In the bleaching and washing compositions containing the sodium percarbonate according to the present invention, non-zeolitic builders can be used in place of zeolite builders and in another general embodiment of the invention. These builders of washing compositions can be, for example, the above-mentioned layered silicates, alkali metal phosphates, particularly tripolyphosphates, and also tetrapyrophosphates and hexametaphosphates, particularly in the form of their sodium salt, alkali metal carbonates, preferably sodium, silicates of alkali metals and alkali metal borates, preferably sodium. Another group of builders which may be present in the bleaching and washing compositions according to the invention are organic chelating builders, such as, for example, aminopolycarboxylates and aminopolyethylenephosphonates or hydroxyphosphonates, including nitrilotriacetate or trimethylenephosphonate, ethylenediaminetetraacetate or tetramethylenephosphonate, diethylenetriaminepentamethylenephosphonate or cyclohexane. 1, 2-diaminotetramethylenephospho-nate which generally exist totally or partially in the form of its sodium salt. The carboxylate chelating builders comprise monomeric carboxylates and oligomers, including glycolic acid and its ether derivatives, such as, for example, salts and derivatives of succinic acids, tartarics, citrates, carboxylic derivatives of succinates, and polyaspartates. Other examples are ethane or propane tetracarboxylates and different sulfosuccinates. The mentioned chelating builders may exist in relatively small amounts in the bleaching and washing compositions, as for example to strengthen the builder properties and the peroxygen stabilizing effect, proportions of 10% by weight being suitable for this purpose., although larger amounts up to 40% by weight, preferably in the proportion of 5 to 20% by weight, can also be used.The washing and bleaching compositions according to the invention also generally contain one or more surfactants in the proportion of 2 to 40. % and particularly 5 to 25% by weight As usual surfactants chosen from the group of anionic, cationic, nonionic, zwitterionic, amphoteric and ampholytic surfactants, as well as natural or synthetic soaps, examples of surfactants can be cited, Examples include, as anionic surfactants, carboxylic acid soaps, alkylaryl sulfonates, olefin sulfonates, linear alkyl sulfonates, hydroxyalkylsulfonates, long chain alcohol bisphosphonates, sulfated glycerides, sulfated ethers, sulfosuccinates, phosphate esters, sucrose esters and surfactants. Fluorine Anionics As examples of cationic surfactants can cite c) quaternary ammonium or pyridinium quaternary salts containing at least one hydrophobic alkyl or arylalkyl group; nonionic surfactants are, for example, condensates of long-chain alcohols with ethylene or phenol polyoxides or condensates of long-chain carboxylic acids or of amines or amides with ethylene polyoxide or corresponding compounds, in which the chain unit long is condensed with an aliphatic polyol such as for example sorbitol or condensation products of ethylene or propylene oxides or of fatty acid alkalonamides and fatty acid amine oxides. Amphoteric or zwitterionic surfactants are, for example, sulfonium and phosphonium surfactants which, if appropriate, can be substituted with another anionic solubilization promoter group. This list is only illustrative and not exhaustive. Other optional components of the washing and bleaching compositions are, for example, as indicated above, dirt carriers, bleach activators, optical brighteners, enzymes, plasticizers, perfumes, dyes and optionally also processing aids. The optional components, except the processing aids, which constitute a separate component, are generally used in the proportion of 20% by weight as a maximum in relation to the composition. They usually reach up to 10% by weight. The processing aids can, if desired, comprise 0 to 40% of the composition as separate components. Carriers of dirt are generally, for example, methyl, carboxymethyl or hydroxyethyl derivatives of cellulose or polyvinylpyrrolidone or polycarboxylic acid polymers such as, for example, copolymers of maleic anhydride with methacrylic acid or ethylenic or methylvinyl ether. Conventional bleach activators are, for example, O-acyl or N-acyl compounds which by reaction with sodium percarbonate form peracids, particularly TAED, SNOBS and its isononyl analogue, TAGU and sugar esters. Suitable optical brighteners are, for example, substituted aminostilbene and in particular triazine aminostilbene. The enzymes may be chosen from the group comprising amylases, neutral or alkaline proteases, lipases, esterases and cellulases, which are obtained in commercial form. The plasticizers are, for example, water-insoluble tertiary amines, optionally in combination with long-chain quaternary ammonium salts and / or high molecular weight ethylene polyoxides. The processing aids are generally sodium and / or magnesium sulfate. In concentrated or ultraconcentrated compositions, the processing aids constitute only a small proportion of at most 5% by weight, but in traditional compositions this proportion can reach up to 20 to 40% by weight. The bleaching and washing compositions according to the invention can be prepared in any conventional manner, for example by dry blending the sodium percarbonate in the form of particles with the desired ingredients which can also be pre-processed in the form of pre-mixes or preformulations. The process according to the present invention as well as the sodium percarbonate prepared according to the invention are distinguished by the following advantages: By means of the invention a method is proposed capable of being implemented in a simple and economical way for the continuous or discontinuous preparation of particles or substantially homogeneous granules of PCS with varying concentrations of active oxygen of 10 to 15.2% by weight, particularly also with high concentrations of active oxygen greater than 14.5 to 15.2% by weight. The method of the invention acts to save energy, since on the one hand refrigeration energy is not needed during the reaction but the temperature can be controlled simply by a normal cooling with water, and on the other hand relatively little water must be evaporated for drying the product . In comparison with the wet process (crystallization process), PCS products free of chlorides are achieved according to the invention., which reduces the danger of corrosion in the installation. In contrast to the wet process, the process according to the invention does not produce waste water to be deposited, while in the wet process alkaline waste water containing hydrogen peroxide and chloride are obtained, which also, before being discarded, they must be neutralized and where they should eventually also decompose the hydrogen peroxide they contain. In contrast to dry processes which only allow active oxygen concentrations of approximately 10% by weight in the PCS, a variable concentration of active oxygen of 10 to 15.2% by weight can be regulated by the process according to the present invention and in particular greater than 14.5 to 15.2% by weight. The concentration of active oxygen in the PCS product is easily controllable in the dry process according to the present invention using a defined sodium carbonate monohydrate, which can be adapted to market requirements and to different products. The dry process according to the present invention guarantees an almost lossless utilization of hydrogen peroxide, and therefore a substantially total yield of active oxygen. This makes it possible to avoid costly excesses of H202 and the reaction of sodium carbonate monohydrate with H202 can be carried out in almost stoichiometric form. The PCS prepared with the process according to the invention is further distinguished by high homogeneity and purity. The PCS particles obtained according to the invention therefore have excellent "stability properties." The process is very flexible, since, unlike the dry process methods of the prior art (where tubular reactors are used), it can be carried out. In conventional mixing and drying devices, the flexibility of the method of the invention is also distinguished because not only can it be carried out discontinuously, but it can also be carried out in a well controlled manner with the continuous technique. then by the following non-limiting embodiment examples: The percentages in the tables and in the text are generally indications of percentage by weight, eg, Example 1: Conditioning of soda to obtain soda monohydrate.

For the preparation of soda monohydrate (sodium carbonate monohydrate), light soda is conditioned in a laboratory mixer from Lódige with heating jacket (water bath, 99 ° C). For this purpose, 2000 g of carbonate of soda are introduced into the mixer and preheated with a low number of revolutions (approximately 20 rpm) for 15 minutes. The mixer speed is then increased to approximately 120 rpm and boiling water is added rapidly in an amount of 520 g. After a residence time of approximately 35 minutes, the product is extracted from the mixer. The control of the reaction to obtain sodium carbonate monohydrate is carried out by DCS analysis and titration of the total alkalinity. 6 loads of soda monohydrate are prepared (see also Example 3). The general conditions of the procedure as well as the average results of analysis of the soda monohydrate products obtained are indicated in the following tables la and Ib.

Table the: Conditioning of soda (Na2C03) to obtain monohydrate soda (Na2C03.H20) in mixer of Lódige Table Ib: Analysis and properties of soda monohydrate (obtained by conditioning soda) Example 2: Preparation of sodium percarbonate The soda monohydrate prepared according to Example 1 is then reacted with hydrogen peroxide to give sodium percarbonate. For this purpose, a heavy amount (approximately 2000 g) of soda monhydrate is introduced into a mixer with kneading tools (Lddige mixer). For each mole of heavy soda monohydrate, 1.5 mole of aqueous hydrogen peroxide (60%) is weighed and stabilized by the addition of Turpinal SL (60% by weight) (Quantity: 5.75% by weight TSL (100 %) in relation to H202 (100%)). The hydrogen peroxide solution stabilized in this way is injected into the Lódige mixer through a double injection nozzle. The injection time is approximately 13 minutes by rotating the mixer at approximately 120 rpm. To control the temperature during the reaction, the mixer is cooled with tap water through its jacket. After the reaction, the product is extracted from the mixer and dried at 80 ° C in an oven. circulating air. The drying is interrupted as soon as the concentration of water or active oxygen in the final product reaches the desired value (< approximately 0.2% water, determination according to Sarto-rius). After cooling the produced sodium percarbonate, quality control was carried out by means of suitable analyzes for PCS. In total, 6 charges of soda monohydrate of Example 1 were reacted in the manner described above. The general procedure conditions of the reaction tests and the average results of the obtained sodium percarbonate analyzes are summarized in the following tables lia and Ilb.

Example 3: Other tests for conditioning and preparation of PCS. Analogously to examples 1 and 2, other tests for the preparation of PCS from soda monohydrate were carried out. The process conditions and properties of the products are summarized in the following table III.

Tabla lia: Reaction of soda monohydrate with hydrogen peroxide to give sodium percarbonate Table Ilb: Analysis and properties of sodium percarbonate produced according to the invention Table III Other Conditioning and Preparation Tests for PCS Conditioning: Reaction with hydrogen peroxide: Reaction with hydrogen peroxide: Example 4: Compaction and dry granulation The "microcrystalline sodium percarbonates prepared according to examples 2 or 3 were subjected to compaction and subsequent dry granulation." The compaction was carried out in a roller compaction machine. type P-50 N / 75 with dry granulation equipment from the company Alexander-Werke, this device being suitable for the continuous densification of powdery or finely crystalline dry products with subsequent crushing (granulation) of the pressed product. obtained by compaction could be controlled by the incorporation of various sets of sieves, for which sieves with meshes of 2.00, 1.25 and 1.00 mm were available. In addition to the sodium percarbonates prepared according to examples 2 and 3, a sodium percarbonate obtained by a crystallization process according to the state of the art (the average particle size of the granulometry) was also compacted and dry granulated, for comparison purposes. this PCS was d = 500 μm.) If desired, 1.0% by weight of sodium stearate powder for compaction was added to the sodium percarbonate, in this way the possibly necessary separation of the surface peels could be improved. of the cylinders The husks separated by themselves without the help of the built-in scraper The granulometry was not affected by the addition of sodium stearate.To find the most convenient conditions of the procedure in preliminary tests, the pressure of the cylinders was first progressively increased from 25 to 120 bar with continuous or constant feed of the product The husks obtained at high pressure could be well granulated through a set of 1.25 mm screens. The granulate then consisted of substantially cubic particles that had satisfactory mechanical strength. Below 50 bar, only friable husks were obtained, which, when granulated, easily crumbled into powder. The increase of the product feeding allowed to obtain thicker husks but when increasing the pressing pressure, they are released in an increasingly abrupt manner from the cylinders. Therefore the most favorable process conditions were pressing pressures in the cylinders from 50 to 100 bar. The coarse granules of sodium percarbonate prepared with the previous compaction and granulation on a set of screens with a mesh opening of 1.25 mm with an average granulometry of 650 μm (873 μm when adding sodium stearate) were analyzed to determine their properties. These granulated products had low abrasion loss (<; 5 o < 8% respectively according to ISO 5937), low loss of stability in dry (6% at 105 ° C, 2 hours) and high dissolution rate (99% after 1 minute, 15 ° C). The apparent specific weight of the sodium percarbonate prepared according to the invention was 0.87 g / ml or 0.93 g / ml, respectively, when sodium stearate was added. According to the results of the microcalorimetric (LKB) measurements and the zeolite test, the PCS granules prepared according to the present invention had good storage stability in a wash composition base. In the microcalorimetric measurement, values of 49 microwatt / g or 57 microwatt / g respectively (by adding sodium stearate) were obtained for the sodium percarbonate prepared according to the invention and in the zeolite test the residual oxygen concentration was approximately 50% or of 56% respectively with the addition of sodium stearate (always measured in relation to PBS-1 as a rule). The detailed analysis results of conventional sodium percarbonate (obtained by crystallization process or in its compacted form), and the sodium percarbonate products prepared according to the present invention with and without added stearate are summarized in the following table IV. Table IV: Properties of sodium percarbonate prepared according to the present invention and comparative tests 4.1 = PCS according to the invention after compaction 4.2 = PCS according to the invention after compaction with addition of sodium stearate VI = Comparative test: properties of commercial PCS prepared by the crystallization process V2 = Comparative procedure: PCS equal to VI, but after additional compaction *) All original samples; without sifted fractions; **) Measurement of LKB values based on washing composition containing zeolite. Mixing ratio: 20% by weight percarbonate and 80% by weight base of washing composition Glossary PCS sodium percarbonate Avox concentration of active oxygen Turpinal SL aqueous solution at 60% by weight of acid 1- (TSL) hydroxyethane-1, 1 -dif osf ónico (HEDP); stabilizer for peroxide Soluble glass Solution at 36% by weight of sodium silicate in water (8% by weight Na20; 25.5% by weight Si02) IFB integrated fluidized bed h hour min: minute mmWS mm column of water P, dP pressure , pressure difference rpm revolutions per minute DSC Differential exploratory calorimetry. DSC covers all processes with energy consumption or dissipation, that is, endothermic and exothermic phase transformations. Measurements LKB Thermal flux measurements. In these thermal flow measurements the thermal flows that occur under isothermal measurement conditions give indications on the stability of the product containing active oxygen. In particular, the stability of the product in the presence of components of washing compositions can also be determined when the thermal flow measurements are carried out in samples in which the "active oxygen-containing product is mixed with components of washing compositions. Thermal flux measurements were carried out in a LKB 2277 Bioactivity Monitor at 40 ° C within 20 hours The lower the measured thermal flux, the greater is the stability of the product containing active oxygen in the composition base. The stability of the wash, that is, the corresponding PCS particles are more stable. Avox Stability Avox Stability Loss = The determination of the thermal stability of the produced sodium percarbonate was used to determine the active oxygen loss (Avox stability). , the product was heated for 2 hours at 105 ° C and the resulting active oxygen loss was determined of decomposition. The determination of active oxygen was carried out by conventional titration methods. H20 (Sartorius) = Initial weight 7.5 g; Test temperature 60 ° C; end of the trial: < 5 Tng / 90 seconds. Zeolite test = 10 g of product and 10 g of zeolite A (2 to 3 μm molecular sieve from Aldrich) were mixed together and allowed to stand for 48 hours in open Petri dish at 32 ° C and 80% relative humidity . Zeolite characteristic = residual AVOX of the sample after storage divided by residual AVOX of the PBS-1 standard after storage. (PBS-1 = sodium perborate monohydrate). Abrasion test = The determination of the abrasion was carried out by ISO 5934, that is to say the proportion of fines was determined gravimetrically. 150 μm that were generated when swirling the sample in a vertical tube using compressed air. The proportion of the amount of fines produced in relation to the total amount indicated the percentages of abrasion.

Claims (32)

Claims

1. - Process for preparing sodium percarbonate, characterized in that in a first stage (= reaction stage) a sodium percarbonate is prepared by a process in which solid monohydrate obtained by conditioning light forms of soda is reacted with a an almost stoichiometric amount, relative to the concentration of active oxygen desired in sodium percarbonate, of a 50-70% by weight aqueous solution of hydrogen peroxide at reaction temperatures up to a maximum of 80 ° C, in a mixing device, with rapid and intense mixing, to form a pasty mass of wet sodium percarbonate and dry, and in a second stage (= stage of compaction or dry granulation) after drying the sodium percarbonate obtained in the first stage, optionally with the addition of 1% by weight of a lubricant, preferably alkali or alkaline earth metal stearate, is compacted forming husks which then, through a dry granulation and by crushing and sieving, it is converted into a granulate of sodium percarbonate with an active oxygen concentration of 10 to 15.2% by weight, preferably greater than 14.5 to 15.2% by weight, and with the desired parameters of the particles comprising apparent specific gravity between 0.85 and 1.1 kg / 1 and average granulometry "of 550 to 1100 μm.

2. Method according to claim 1, characterized in that the reaction temperatures are maintained during the exothermic reaction in the range from room temperature to a maximum of 80 ° C, preferably in the range from more than 20 ° C up to a maximum of 80 ° C.

3. Process according to claim 1, characterized in that, in relation to sodium percarbonate with the theoretical global formula Na2C03 x 1.5 H202, an almost stoichiometric amount, preferably 1.49 to 1.52 Mol (H202) of the aqueous solution of hydrogen peroxide.

4. Process according to claim 1, characterized in that an aqueous solution of hydrogen peroxide is used 55 to 65% by weight.

5. Process according to claim 1, characterized in that the aqueous solution of hydrogen peroxide is fed through a nozzle, preferably a two-component nozzle, to the mixer which already contains the solid monohydrate monohydrate.

6. Method according to claim 1, characterized in that light soda of apparent specific weight 0.50 is used. 0.55 kg / 1 obtained by conditioning of solid soda monohydrate.

7. Process according to claim 1, characterized in that a super light soda of apparent specific gravity of less than 0.50 kg / 1 obtained by conditioning of solid soda monohydrate is used.

8. Process according to claim 1, characterized in that the reaction of the soda monohydrate with the aqueous solution of hydrogen peroxide is carried out as quickly as possible in a high intensity mixer.

9. Method according to claim 1, characterized in that the compaction is carried out at a pressure of at least 50 bar up to a maximum of 150 bar, preferably at a pressure of 80 to 120 bar.

10. Process according to claim 1, characterized in that a granulate of sodium percarbonate with an average granulometry higher than 600 μm, preferably 640 a 1000 μm.

11. Process according to claim 1, characterized by preparing a granulate of sodium percarbonate with an apparent specific gravity of 0.93 to 1.1 kg / 1.

12. Method according to one of claims 10 to 11, characterized in that it is compacted with the addition of up to 1% by weight of sodium stearate or magnesium stearate.

13. Sodium percarbonate, characterized in that it has an active oxygen concentration greater than 14.5 to 15.2% by weight, calculated without granulation aids optionally added during the preparation and / or granulation, and has a dissolution rate of at least 95% after 1 minute and at least 99% after 2 minutes (under standard conditions: 2 g, 15 ° C).

14. Sodium percarbonate, characterized in that it has an active oxygen concentration greater than 14.5 to 15.2% by weight, calculated without any added granulation aids during the preparation and / or the granulation, and a superior exothermic DSC peak at 155 ° C, particularly in the range 159 to 162 ° C.

15. Sodium percarbonate, characterized in that it has an active oxygen concentration greater than 14.5 and up to 15.2% by weight, calculated without any added granulation aids during the preparation and / or granulation, and a loss of stability less than 6.2%, preferably 3.4 to 5.1%, measured under standard conditions (105 ° C, 2 hours).

16. Sodium percarbonate according to one of the claims 13 to 15, characterized in that it has an average granulometry of 550 to 1100 μm, preferably 640 to 1000 μm.

17. Sodium percarbonate according to one of the claims 15 to 15, characterized in that it has an apparent specific weight of 0.85 to 1.1 kg / 1.

18. Sodium percarbonate according to one of the claims 16 or 17, characterized in that it has an abrasion index of less than 5% (measured under standard conditions).

19. Sodium percarbonate according to one of claims 13 or 14, characterized in that it contains up to 1% by weight of a lubricant introduced during the granulation and chosen from the group comprising alkali metal or alkaline earth metal stearates and has an apparent specific gravity of 0. , 93 to 1.1 kg / 1.

20. Sodium percarbonate according to claim 19, characterized in that it has an abrasion index of less than 8% (measured under standard conditions).

21. Sodium percarbonate according to one of claims 13 to 20, characterized in that it is obtained by a process according to claims 1 to 12.

22. Sodium percarbonate according to one of claims 13 to 15, characterized in that it is obtained by a The process according to claims 1 to 12 without adding lubricant in compaction or dry granulation and has a stability loss lower than 6.2% measured under standard conditions (105 °, 2 hours).

23. - Sodium percarbonate according to one of claims 13 to 15, characterized in that it is obtained by a process according to claims 10 to 15 without the addition of lubricants in the dry compaction / granulation, and has an average granulometry of 550_ to 1100 μm, preferably 640 to 1000 μm.

24. Sodium percarbonate according to one of claims 13 to 15, characterized in that it is obtained by a process according to claims 1 to 12 without the addition of lubricants in the dry compaction / granulation, and has an apparent specific gravity of 0, 85 to 1.1 kg / 1.

25. Sodium percarbonate according to one of claims 23 or 24, characterized in that it has an abrasion index of less than 5% (under "normalized conditions")

26. Sodium percarbonate according to one of claims 13 or 14, characterized in that is obtained by a process according to claims 1 to 12 with the addition of up to 1% by weight of a lubricant in the dry compaction / granulation, preferably with the addition of alkali metal and / or alkaline earth metal stearate, having an active oxygen concentration greater than 14.5% by weight, preferably greater than 14.8% by weight, and a maximum stability loss of 12.0 (measured under standard conditions: 105 ° C, 2 hours).

27. Sodium percarbonate according to one of claims 13 or 14, characterized in that it is obtained by a process according to claims 1 to 12 with the addition of up to 1% by weight of a lubricant in the dry compaction / granulation, preferably with alkali metal or alkaline earth metal stearate having an active oxygen concentration greater than 14.5% by weight up to 15% by weight, preferably greater than 14.8% by weight up to 15.0% by weight and an average particle size of 800 to 1000 μm.

28. Sodium percarbonate according to one of claims 13 or 14, characterized in that it is obtained by a process according to claims 11 to 12 with the addition of up to 1% of a lubricant in the dry compaction / granulation, preferably with the addition of alkali metal or alkaline earth metal stearate, having an active oxygen concentration greater than 14.5% by weight up to 15% by weight, preferably greater than 14.8% by weight up to 15%, 0% by weight, and an apparent specific gravity from 0.93 to 1.1 kg / 1. 29.- Sodium percarbonate according to one of claims 27 or 28, characterized in that it has a maximum abrasion index of 8% (measured under standard conditions). washing or bleaching solid containing 0, 5 to 40% by weight and preferably 5 to 25% by weight of a sodium percarbonate according to one of claims 13 to 29 and 99.5 to 60% by weight, preferably 95 to 75% by weight of auxiliaries and substances of conventional formulations in washing and bleaching compositions chosen from the group comprising surfactants, builders, bleach activators, peracid bleach precursors, enzymes, enzyme stabilizers, dirt carriers and carriers, complexing and chelating agents, foam regulators and additives such as optical brighteners, opacifiers, corrosion inhibitors, anti-electrostatic, colorants, bactericides. 31. Washing and bleaching composition according to claim 30, characterized in that it contains a sodium percarbonate according to one of claims 13 to 24 in the presence of builders of the group of zeolites. 32. Washing and bleaching composition according to claim 30 or 31, characterized in that it is a compact washing composition.