MGDA GRANULES AND (MET)ACRYLIC ACID HOMOPOLYMER OR COPOLYMER; PROCESS FOR MAKING THEM

Abstract

A process for preparing a granule containing (A) at least one chelating agent selected from alkali metal salts of methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS) and, optionally, (B) at least one homopolymer or copolymer of (meth)acrylic acid, partially or completely neutralized with alkali, wherein said process comprises the steps of (a) providing an aqueous solution or slurry containing chelating agent (A) and, if applicable, (co)polymer (B), (b) removing most of said water by spray granulation in a fluidized bed, (c) treating the resulting granule in a vessel at least a portion of which rotates about a horizontal axis and wherein said vessel is selected from paddle mixers, drop mixers, and grate mixers.

Description

MGDA GRANULES AND (MET)ACRYLIC ACID HOMOPOLYMER OR COPOLYMER; PROCESS FOR MAKING THEM The present invention relates to a process for preparing a granule containing (A) at least one chelating agent selected from alkali metal salts of methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS) and, optionally, (B) at least one homopolymer or copolymer of (meth)acrylic acid, partially or completely neutralized with alkali, wherein said process comprises the steps of (a) providing an aqueous solution or slurry containing chelating agent (A) and, if applicable, (co)polymer (B), (b) removing most of said water by spray granulation in a fluidized bed, (c) treating the granule resulting from step (b) with air or an inert gas in a vessel at least a portion of which rotates about a horizontal axis and wherein said vessel is selected from paddle mixers, drop mixers, and grate mixers. Chelating agents, such as methylglycinediacetic acid (MGDA) and its respective alkali metal salts, are useful sequestering agents for alkaline earth metal ions, such as Ca2+ and Mg2+. For this reason, they are recommended and used for various purposes, such as in laundry detergents and automatic dishwasher (ADW) formulations, particularly in so-called phosphate-free laundry detergents and phosphate-free ADW formulations. These chelating agents are most often delivered in solid form, such as powders or granules, or as aqueous solutions. Depending on the product type (liquid household and fabric care products versus solid household and fabric care products) and the manufacturing process, manufacturers may prefer to handle aminocarboxylate solutions or solid aminocarboxylates, for example, through combined spray drying or solid blending. Aminocarboxylate powders and granules can be shipped economically due to their high active ingredient content combined with low water content. Therefore, convenient processes for producing granules remain of significant commercial interest. WO 2009 / 103822 discloses a process in which the slurries are granulated and have a certain solids content, with a gas inlet temperature of 120°C or less. WO 2012 / 168739 discloses a process in which slurries of complexing agents are spray-dried under non-agglomeration conditions. WO 2012 / 041741 discloses a process where complexing agents are dried using a jet bed. However, large-scale application of jet bed reactors is difficult. ADW formulations typically contain up to 40% MGDA enhancer and are packaged in single-unit doses (SUDs). Space in these SUDs is limited, so a higher bulk density is desirable, as it allows for more active product per unit volume. Therefore, an object of the present invention was to provide a process for producing chelating agent granules with increased bulk density and reduced hygroscopicity. Furthermore, an object of the present invention was to provide chelating agent granules with increased bulk density and reduced hygroscopicity. Accordingly, the process as defined at the outset, hereinafter also referred to as the inventive process or the process according to the present invention, has been discovered. The inventive process comprises several steps, which may be referred to as step (a), step (b), or step (c), and which will be explained in more detail below. The inventive process is a process for producing a granule. The term "granule" in the context of the present invention refers to particulate materials that are solid at room temperature and preferably have an average particle diameter (D50) in the range of 0.1 mm to 2 mm, preferably 0.4 mm to 1.25 mm, and even more preferably 400 µm to 1 mm. The average particle diameter of the inventive granules can be determined, for example, by optical methods or, preferably, by sieving. The sieves used can have a mesh size in the range of 60 to 3,000 µm. In one embodiment of the present invention, the granules produced according to the present invention have a broad particle diameter distribution. In another embodiment of the present invention, the granules produced according to the present invention have a narrow particle diameter distribution. The particle diameter distribution can be adjusted, if desired, by multiple sieving stages. The granules produced by the inventive process may contain residual moisture, where moisture refers to water including water of crystallization and absorbed water. The amount of water may be in the range of 0.1 to 20% by weight, preferably 1 to 15% by weight, which refers to the total solids content of the respective granule, and may be determined by Karl Fischer titration or by drying at 160°C to 200°C to constant weight using infrared light. The granule particles produced by the inventive process have a regular shape: they are spheroidal. The granule particles produced by the inventive process contain at least one chelating agent, hereinafter also referred to as the chelating agent (A). The chelating agent (A) is selected from alkali metal salts of methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS). The alkali metal salts of MGDA are selected from compounds according to the general formula (I a) [CH3-CH(COO)-N(CH2-COO)2]M3.xHx (I a) where M is selected from alkali metal cations, the same or different, for example, lithium, sodium, potassium, rubidium, cesium cations, and combinations of at least two of the above. Preferred examples of alkali metal cations are sodium and potassium and combinations of sodium and potassium. x in Formula (I a) is in the range of zero to 1.0, preferably from zero to 0.5. In a particularly preferred embodiment, x is zero. The alkali metal salts of IDS are selected from compounds according to the general formula (I b) [HN-(CH(COO)-CH2COO)2]M4-xHx (I c) where M is selected from alkali metal cations, the same or different, as defined above, x in Formula (I b) is in the range of zero to 2.0, preferably from zero to 0.5. In a particularly preferred embodiment, x is zero. In one embodiment of the present invention, the alkali metal salts of MGDA are selected from lithium salts, potassium salts, and preferably sodium salts of MGDA. MGDA may be partially or, preferably, completely neutralized with the respective alkali. In a preferred embodiment, an average of 2.7 to three COOH groups of MGDA are neutralized with an alkali metal, preferably sodium. In a particularly preferred embodiment, the chelating agent (A) is the trisodium salt of MGDA. MGDA and its respective alkali metal salts are selected from racemic mixtures, the D isomers and the L isomers, and from mixtures of the D and L isomers other than racemic mixtures. Preferably, MGDA and its respective alkali metal salts are selected from the racemic mixture and from mixtures containing 55 to 85 mol% of the L isomer, the remainder being the D isomer. Mixtures containing 60 to 80 mol% of the L isomer, the remainder being the D isomer, are particularly preferred. Racemic mixtures are also particularly preferred embodiments. IDS and its respective alkali metal salts are selected from various mixtures of stereoisomers, for example, D,D-IDS, L,L-IDS, and D,L-IDS and combinations thereof. Preferably, these are optically inactive mixtures as they are more economical to prepare. In any case, the smaller amounts of chelating agent (A) may contain a cation other than an alkali metal. Therefore, it is possible that smaller amounts, such as 0.01 to 5 mol% of total IDS or MGDA, respectively, may contain alkaline earth metal cations, such as Mg2+ or Ca2+, or an Fe2+ or Fe3+ cation. In one embodiment of the present invention, the alkali metal salts of the chelating agent (A) may contain one or more impurities that may arise from the synthesis of the respective chelating agent (A). In the case of MGDA and its alkali metal salts, such impurities may be selected from propionic acid, lactic acid, alanine, nitrilotriacetic acid (NTA), or similar compounds and their respective alkali metal salts. In the case of IDS, such impurities may be selected from maleic acid, maleic / fumaric acid monoamides, and racemic asparagine. Such impurities are typically present in minor quantities. Minor quantities in this context refer to a total of 0.1 to 5% by weight, with reference to the alkali metal salt of the chelating agent (A), preferably up to 2.5% by weight. In the context of the present invention, such minor quantities are disregarded when determining the composition of the granule prepared according to the inventive process. In one particular embodiment of the present invention, a combination of alkali metal salts of at least two chelating agents is used, for example, sodium salts of MGDA and ISD in a weight ratio of 1:1 to 5:1. In other embodiments, the alkali metal salts of only one chelating agent are used, in particular sodium metal salts of MGDA. The granule particles produced by the inventive process may further contain (B) at least one homopolymer or copolymer of (meth)acrylic acid, partially or completely neutralized with alkali, hereinafter also referred to as polymer (B). Polymers (B) that are homopolymers are also referred to as homopolymers (B), and polymers (B) that are copolymers are also referred to as copolymers (B). The polymer (B) is selected from homopolymers (B) of (meth)acrylic acid and copolymers (B) of (meth)acrylic acid, preferably acrylic acid, partially or completely neutralized with alkali. In the context of the present invention, the copolymers (B) are those in which at least 50 mol% of the comonomers are (meth)acrylic acid, preferably at least 75 mol%, and even more preferably from 80 to 99 mol%. Suitable comonomers for copolymers (B) are ethylenically unsaturated compounds such as styrene, isobutene, ethylene, α-olefins such as propylene, 1-butylene, 1-hexene, and ethylenically unsaturated dicarboxylic acids and their alkali metal salts and anhydrides such as, among others, maleic acid, fumaric acid, itaconic acid, disodium maleate, disodium fumarate, itaconic anhydride, and especially maleic anhydride. Other examples of suitable comonomers are C1-C4 alkyl esters of (meth)acrylic acid, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate. In one embodiment of the present invention, the (co)polymer (B) is selected from (meth)acrylic acid copolymers and a comonomer having at least one sultani acid group per molecule. The comonomers having at least one sultani acid group per molecule can be incorporated into the (co)polymer (B) as a free acid or at least partially neutralized with alkali.Particularly preferred comonomers containing a sultanidic acid group are 1-acrylamido-1-propansulfonic acid, 2-acrylamido-2-propansulfonic acid, 2-acrylamido-2-methylpropansulfonic acid (AMPS), 2-methacrylamido-2-methylpropansulfonic acid, 3-methacrylamido-2-hydroxypropansulfonic acid, allylsulfonic acid, metalylsulfonic acid, allyloxybenzenesulfonic acid, metalyloxybenzenesulfonic acid, 2-hydroxy-3-(2-propenyloxy)propansulfonic acid, 2-methyl-2-propen-15 sulfonic acid, styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl acrylate, 2-sulfoethyl methacrylate, 3-sulfopropyl methacrylate, sulfomethacrylamide, sulfomethylmethacrylamide and salts of said acids, such as sodium salts, potassium salts or ammonium salts of these. The copolymers (B) can be selected from random copolymers, alternating copolymers, block copolymers and graft copolymers, with alternating copolymers and especially random copolymers being preferred. Useful copolymers (B) include, for example, random copolymers of acrylic acid and methacrylic acid, random copolymers of methacrylic acid and maleic anhydride, random copolymers of acrylic acid, methacrylic acid, and maleic anhydride, block or random copolymers of acrylic acid and styrene, and random copolymers of acrylic acid and methacrylic acid. Methacrylic acid homopolymers are preferred. Acrylic acid homopolymers are even more preferred. The (co)polymers (B) can be branched or linear chain molecules. Branching in this context occurs when at least one repeating unit of such a (co)polymer (B) is not part of the main chain, but forms a branch or part of a branch. Preferably, the (co)polymer (B) is not cross-linked. In one embodiment of the present invention, the (co)polymer (B) has an average molecular weight Mw in the range of 1,200 to 30,000 g / mol, preferably 2,500 to 20,000 g / mol and, even more preferably, 5,000 to 18,500 g / mol, determined by gel permeation chromatography (GPC), with reference to the respective free acid. In one embodiment of the present invention, the (co)polymer (B) is at least partially neutralized with alkali, for example, with lithium, potassium, sodium, or combinations of at least two of the foregoing, especially with sodium. For example, in the range of 10 to 100 mol%, the carboxyl groups of the (co)polymer (B) can be neutralized with alkali, especially with sodium. In one embodiment of the present invention, the (co)polymer (B) is selected from per-sodium salts of polyacrylic acid, i.e., polyacrylic acid completely neutralized with sodium. In one embodiment of the present invention, the (co)polymer (B) is selected from a combination of at least one polyacrylic acid and at least one (meth)acrylic acid copolymer and a comonomer having at least one sulfonic acid group per molecule, wherein both polymers are completely neutralized with alkali. In one embodiment of the present invention, the (co)polymer (B) is selected from per-sodium salts of polyacrylic acid with an average molecular weight Mwen in the range of 1,200 to 30,000 g / mol, preferably from 2,500 to 20,000 g / mol and, even more preferably, from 5,000 to 18,500 g / mol, determined by gel permeation chromatography (GPC), with reference to the respective free acid. In embodiments where a (co)polymer (B) is present, the weight ratio of (A):(B) is in the range of 2:1 to 1,000:1, preferably from 7.5:1 to 1,000:1 and, more preferably, from 40:1 to 100:1. In this weight ratio, impurities of the chelating agent (A) are ignored. IVIA / a / ZUZZ / UU / ¿14 which come from the synthesis, see above. The granule particles produced by the inventive process may contain at least 75% by weight of chelating agent (A). The content of chelating agent (A) may be determined, for example, by potentiometric titration with FeCl₂. The percentage refers to the solids content of said granule and may be determined by Karl Fischer titration or by drying at 160°C to 200°C to constant weight using infrared light. Excludes crystallization water. The granules produced by the inventive process may contain residual moisture, where moisture refers to water including water of crystallization and absorbed water. The amount of water may be in the range of 0.1 to 20% by weight, preferably 1 to 15% by weight, which refers to the total solids content of the respective granule, and may be determined by Karl Fischer titration or by drying at 160°C to 200°C to constant weight using infrared light. In one embodiment of the present invention, in the (co)polymer (B) containing granules prepared for the inventive process, the chelating agent (A) and the (co)polymer (B) are homogeneously dispersed. This means that essentially all the particles of said granule contain the chelating agent (A) and the (co)polymer (B) and that they are not core-shell particles, but rather that the chelating agent (A) and the (co)polymer (B) are distributed over such particles. Such homogeneous dispersion is best achieved when step (a) of the inventive process is initiated from a solution of chelating agent (A) and (co)polymer (B). In another embodiment of the present invention, in the (co)polymer (B) containing granules prepared by the inventive process, the chelating agent (A) and the (co)polymer (B) are dispersed non-homogeneously. Such non-homogeneous dispersion is best achieved when step (a) of the inventive process is initiated from a slurry of chelating agent (A) and (co)polymer (B). The inventive process is now described in greater detail. In step (a), an aqueous solution or slurry of chelating agent (A) and, if applicable, (co)polymer (B) is provided. Such a slurry or aqueous solution can be prepared by known processes. For example, an aqueous solution of alkali metal salts of chelating agent (A) can be obtained from its synthesis. Such a solution can be further concentrated by the addition of solid chelating agent (A) or by evaporation of water. The (co)polymer (B) can be added, if desired, as a solid or as an aqueous solution. Step (a) can be carried out at room temperature. In another embodiment, step (a) is carried out at 20°C or at an elevated temperature, for example, at a temperature in the range of 25 to 90°C, preferably 60 to 75°C. The water used in step (a) may be present in an amount sufficient to dissolve both the chelating agent (A) and the (co)polymer (B). However, it is also possible to use smaller quantities of water and mix the chelating agent (A) and the (co)polymer (B) in a way that forms a slurry. Solutions are preferred. In one embodiment of the present invention, the total solids content of said solution or slurry formed as a result of step (a) is in the range of 20 to 75%, preferably 35 to 50%. In step (b), most of the water is removed from the aqueous solution or slurry provided in step (a) by spray granulation in a fluidized bed. The aqueous slurry or aqueous solution according to step (a) can have a temperature in the range of 15 to 95°C, preferably 20 to 90°C and even more preferably 50 to 90°C. In step (b), the aqueous slurry or aqueous solution is introduced into a spray granulator. In the context of the present invention, a spray granulator typically contains a fluidized bed, which in the context of the present invention is a fluidized bed of chelating agent (A) or granule prepared according to the present invention. Such a fluidized bed of chelating agent (A) is preferably in crystalline form, for example, at least 66% crystalline, as determined by X-ray diffraction. In one embodiment of the present invention, the fluidized bed can have a temperature in the range of 75 to 150°C, preferably 80 to 110°C. The atomization is carried out through one or more nozzles per spray granulator. Suitable nozzles include, for example, high-pressure rotary drum atomizers, rotary atomizers, three-fluid nozzles, single-fluid nozzles, three-fluid nozzles, and two-fluid nozzles, with single-fluid, two-fluid, and three-fluid nozzles being preferred. The first fluid is the aqueous slurry, aqueous solution, or emulsion, respectively. The second fluid is compressed hot gas, also referred to as the hot gas inlet stream, for example, with a pressure of 1.1 to 7 bar. The hot gas inlet stream can have a temperature in the range of at least 125°C to 250°C, preferably 150 to 250°C, and even more preferably 160 to 220°C. In step (b), the aqueous slurry or aqueous solution of the complexing agent (A), and optionally the (co)polymer (B), is introduced in the form of droplets into said fluidized bed. In one embodiment of the present invention, the droplets formed during spray granulation have an average diameter in the range of 10 to 500 µm, preferably 20 to 180 µm, and even more preferably 30 to 100 µm. In one embodiment of the present invention, the waste gas exiting the spray granulator can have a temperature in the range of 40 to 140°C, preferably 80 to 110°C, but not cooler than the hot gas stream. Preferably, the temperature of the waste gas exiting the drying vessel and the temperature of the solid product present in the drying vessel are identical. In one embodiment of the present invention, the pressure in the spray tower or spray granulator in stage (b) is a normal pressure of +100 mbar, preferably a normal pressure of ±20 mbar, for example, one mbar less than the normal pressure. In one embodiment of the present invention, especially in a process for making an inventive granule, the average residence time of the chelating agent (A) in step (b) is in the range of 2 minutes to 4 hours, preferably from 30 minutes to 2 hours. In embodiments where an aged grout is used, such aging can last in the range of 2 hours to 24 hours at a temperature preferably higher than room temperature. During step (b), most of the water is removed in a fluidized bed. "Most of the water" means that a residual moisture content of 0.1 to 20% by weight, with reference to the granule, may remain. In embodiments that start from a solution, approximately 51 to 75% by weight of the water present in the aqueous solution is removed in step (b). A granule is obtained, hereinafter also referred to as the resulting particulate residue or stage (b) granule. This stage (b) granule has the appearance of a granule that may have an apparent density in the range of 700 to 950 g / L. The particles of the stage (b) granule may show some degree of irregularity in shape. At the end of step (b), the granule from step (b) is removed from the spray granulator. This granulator was at least partially formed during step (b) of the inventive process. This removal can be carried out through one or more openings in the spray tower or spray granulator. Preferably, such one or more openings are located at the bottom of the respective spray tower or spray granulator. The granules are removed, including fines and lumps. In step (c), the pellet from step (b) is treated with air, an inert gas, or a combination thereof in a container, at least part of which rotates about a horizontal axis. Examples of inert gases include nitrogen and rare gases such as argon. Air and inert gases are also possible. Preferably, such air or inert gas is dry. In this context, "dry" is understood to mean less than 5 g of H₂O per kg of gas. As mentioned above, stage (c) is transported in a vessel, at least part of which rotates about a horizontal axis, for example, a mixing element or a mixer. Preferably, the mixing element rotates about a horizontal axis while the rest of the reactor does not. Various embodiments of the reactor design are possible for carrying out step (c) of the inventive process. Step (c) of the inventive process is carried out in a forced circulation mixer. Examples of forced circulation mixers are paddle mixers and grate mixers. Even more preferentially, stage (c) is performed in a so-called free-fall mixer. While free-fall mixers use gravitational forces to move particles, forced-circulation mixers operate with moving mixing elements, specifically rotating mixing elements installed in the mixing chamber. In the context of the present invention, the mixing chamber is the interior of the reactor. Examples of forced-circulation mixers include grate mixers, paddle mixers, and shovel mixers. Grate mixers are preferred. Preferred grate mixers are installed horizontally, where the term "horizontally" refers to the axis around which the mixing element rotates. Preferably, the inventive process is carried out in a paddle mixing tool, in a paddle mixing tool, in a blade mixing tool and, more preferably, in a grate mixer, for example, according to the throwing and turning principle. In a preferred embodiment of the present invention, the inventive process is carried out in a free-fall mixer. Free-fall mixers use gravitational force to achieve mixing. In a preferred embodiment, step (c) of the inventive process is carried out in a drum or tube-shaped container that rotates about its horizontal axis. In a preferred embodiment, step (c) of the inventive process is carried out in a rotating container having baffles. In one embodiment of the present invention, the container or at least parts thereof rotate in the range of 5 to 200 rounds per minute, preferably from 5 to 60 rounds per minute. In one embodiment of the present invention, step (c) of the inventive process is carried out with a forced circulation mixer operated with a Fraude number (Fr) in the range of 1 to 10. In another embodiment, step (c) of the inventive process is carried out with a forced circulation mixer operated with a Fraude number below 1. In the context of the present invention, the Fraude number is defined as Fr = v² / gl, with the variable v as circumferential speed, wherein the variable l is the diameter of, for example, the respective forced circulation mixer or free-fall mixer, and the variable g is gravitational acceleration. In a preferred embodiment of the present invention, which enables the pneumatic conveying of said particulate material, a pressure differential in the range of up to 400 mbar is applied. The granule can be blown out of the mixer or removed by suction. In one embodiment of the present invention, the inlet pressure is higher, but close to, the desired reactor pressure. Pressure drops at the gas inlet must be compensated for. During the inventive process, strong shear forces are introduced due to the shape of the reactor, and the particles in the agglomerates are frequently exchanged, allowing access to the entire particle surface. Through this inventive process, particulate materials can be coated in a short time, and in particular, cohesive particles can be coated very uniformly. In a preferred embodiment of the present invention, the inventive process comprises the step of removing the coated material from the container or containers, by pneumatic transport, for example, at 20 to 100 m / s. In one embodiment of the present invention, step (c) is carried out at a temperature in the ambient temperature range of 115°C, preferably from 30 to 80°C. Preferably, the material obtained from step (b) is introduced directly into step (c) and cooled during step (c). In one embodiment of the present invention, step (c) has a duration in the range of 1 minute to 5 hours, preferably from 5 to 30 minutes. During stage (c), the gas atmosphere can be renewed, for example, once up to 5 times per hour. After step (c), a granule with an excellent spherical shape is obtained from the particles. It exhibits reduced hygroscopicity and can be used directly for the preparation of, for example, automatic dishwasher formulations. In a preferred embodiment of the present invention, step (c) is followed by step (d) which includes the removal of fines. Such step (d) may include a screening or winnowing stage, or air classification. The fines formed during step (c) can be readily removed and, for example, recycled in step (b). In the context of step (d), it is intended that the fines have a diameter in the range of nearly zero to less than 100 µm. The portion of fines removed in step (d) may be in the range of 0.5 to 20% by weight of the total chelating agent (A) removed after step (c), preferably 4 to 8% by weight. Other steps are possible, for example, the removal of lumps after step (b) or (d), preferably after step (b). In this context, the lumps to be separated can also be referred to as oversize material, and lumps are particles with a minimum particle diameter of 2 mm or more, or exceeding the specified maximum diameter by at least 15%. The lumps can be removed, for example, using a discharge screw or a rotary valve, generally along with the desired product, which is then graded. An additional aspect of the present invention relates to granules, hereinafter also referred to as inventive granules. The inventive granules contain (A) at least one chelating agent selected from alkali metal salts of methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS), (B) at least one (meth)acrylic acid copolymer with a monomer having at least one sulfonic acid group per molecule, partially or completely neutralized with alkali, hereinafter also referred to as copolymer (B*) or simply (B*), in a weight ratio of (A):(B*) from 2:1 to 1,000:1, preferably from 7.5:1 to 1,000:1, wherein said granule contains at least 75% by weight of chelating agent (A), and wherein said granule has a width-to-length ratio in the range of 1:1 to 1:0.75. The ratio of amplitude to average length is determined as the b / l ratio, for example, determined by dynamic image analysis, for example, with a Camsizer. The inventive granules may contain (A) and (B*) in molecularly dispersed form or as a core-shell arrangement, where the molecularly dispersed form is preferred. In the context of the present invention, the expression "molecularly dispersed" implies that all or a large majority, for example, at least 80%, of the inventive granule particles contain chelating agent (A) and copolymer (B*). The expression "molecularly dispersed" also implies that the chelating agent (A) and the copolymer (B) are distributed over the particle diameter in a nearly homogeneous manner. In one embodiment of the present invention, the inventive granules are selected from granules with an average particle diameter in the range of 0.1 mm to 2 mm, preferably from 0.75 mm to 1.25 mm. In one embodiment of the present invention, the inventive granule contains from 85 to 99.9% by weight of chelating agent (A) and from 0.1 to 15% by weight of copolymer (B*), wherein the percentages refer to the solids content of said granule. In this weight ratio, impurities in the chelating agent (A) arising from the synthesis, as discussed above, are disregarded. The chelating agent (A) has been described in detail above. The copolymer (B*) is a copolymer of (meth)acrylic acid with a comonomer having at least one sultani acid group per molecule, partially or completely neutralized with alkali, preferably an acrylic acid copolymer with a comonomer having at least one sultani acid group per molecule. In a preferred embodiment, said comonomer having at least one sultani acid group per molecule is 2-acrylamido-2-methylpropansulfonic acid. In one embodiment of the present invention, the copolymer (B*) has an average molecular weight Mwen in the range of 1,200 to 30,000 g / mol, preferably 2,500 to 20,000 g / mol and, even more preferably, 5,000 to 19,000 g / mol, determined by gel permeation chromatography (GPC), with reference to the respective free acid. The copolymers (B*) can be selected from block copolymers, graft copolymers, and random copolymers, with random copolymers being preferred. The copolymers (B*) can be linear or branched chain, with linear chain being preferred. The inventive granules exhibit advantageous general properties, including, but not limited to, excellent hygroscopicity and bulk density. Furthermore, their tendency to yellow, especially in the presence of bleaching agents, is low. Therefore, they are highly suitable for the manufacture of cleaning agents containing at least one bleaching agent, such as cleaning agents, hereinafter referred to as bleach. In particular, the inventive granules are suitable for the manufacture of cleaning agents for fibers or hard surfaces, where such cleaning agents contain at least one peroxy compound. Another aspect of the present invention is, therefore, the use of an inventive granule for the preparation of a cleaning agent that may contain at least one bleaching agent, and in particular, for the preparation of a cleaning agent for fibers or hard surfaces, wherein said cleaning agent contains at least one peroxy compound. Another aspect of the present invention is a process for preparing a cleaning agent by combining at least one inventive granule with at least one bleaching agent, preferably at least one peroxy compound. Another aspect of the present invention is a cleaning agent, hereinafter also referred to as an inventive cleaning agent. Inventive cleaning agents may contain at least one bleaching agent and at least one inventive granule. Inventive cleaning agents exhibit a reduced tendency to yellow and therefore have an extended shelf life. Examples of suitable peroxy compounds are sodium perborates, anhydrous or, for example, as monohydrate or tetrahydrate or the so-called dihydrate, sodium percarbonate, anhydrous or, for example, as monohydrate, hydrogen peroxide, persulfates, organic peracids such as peroxylauric acid, peroxystearic acid, peroxy-α-naphthoic acid, 1,12-diperoxidodecanedioic acid, perbenzoic acid, peroxylauric acid, 1,9-diperoxyzelaic acid, diperoxyisophthalic acid, in each case as a free acid or as an alkali metal salt, in particular as a sodium salt, also sulfonylperoxy acids and cationic peroxy acids. In a preferred embodiment, the peroxy compound is selected from the group of inorganic perborates, persulfates, and percarbonates. Examples of sodium percarbonates include 2 Na₂CO₃·3 H₂O₂. Examples of sodium perborate include (Na₂[B(OH)₂(O₂)]₂), sometimes written as NaBO₂·O₂·3H₂O instead. The most preferred peroxy compound is sodium percarbonate. The term cleaning agents includes compositions for dishwashing, especially hand dishwashing and automatic dishwashers and utensil washing, and compositions for cleaning hard surfaces such as, among others, compositions for cleaning bathrooms, cleaning kitchens, cleaning floors, descaling pipes, cleaning windows, cleaning cars, including cleaning trucks, as well as cleaning open plants, on-site cleaning, cleaning metals, disinfecting cleaning, cleaning farms, high-pressure cleaning and, in addition, detergent compositions for washing clothes. Such cleaning agents may be liquids, gels, or, preferably, solids at room temperature, with solid cleaning agents being preferred. They may be in the form of a powder or granule, or in a unit dose, for example, as a tablet. In one embodiment of the present invention, the inventive cleaning agents may contain in the range of 2 to 50% by weight of inventive granule, in the range of 0.5 to 15% by weight of bleach. The percentages are based on the solids content of the respective inventive cleaning agent. Inventive cleaning agents may contain other ingredients, such as one or more surfactants, which may be selected from nonionic, zwitterionic, cationic, and anionic surfactants. Other ingredients that may be contained in inventive cleaning agents may be selected from bleaching activators, bleaching catalysts, corrosion inhibitors, sequestering agents other than the chelating agent (A), enzymes, fragrances, colorants, antifoaming agents, and enhancers. Particularly advantageous inventive cleaning agents may contain one or more complexing agents other than MGDA or GLDA. Advantageous detergent compositions for cleaners and advantageous laundry detergent compositions may contain one or more sequestering agents other than a mixture according to the present invention. Examples of sequestering agents other than a mixture according to the present invention are citrate, phosphonic acid derivatives, for example, the disodium salt of hydroxyethan-1,1-diphosphonic acid (HEDP), and polymers with complexing groups such as, for example, polyethyleneimine in which 20 to 90 mol% of the N atoms have at least one CH2COO· group, and their respective alkali metal salts, especially their sodium salts, for example, IDS-Na4 and trisodium citrate, and phosphates such as STPP (sodium tripolyphosphate).Because phosphates pose environmental problems, it is preferable that advantageous inventive cleaning agents be phosphate-free. Phosphate-free, in the context of the present invention, means that the total phosphate and polyphosphate content is in the range of 10 ppm to 0.2% by weight, as determined by gravimetric methods and with reference to the respective inventive cleaning agent. Inventive cleaning agents may contain one or more surfactants, preferably one or more non-ionic surfactants. The preferred non-ionic surfactants are alkoxylated alcohols, di- and multiblock copolymers of ethylene oxide and propylene oxide and reaction products of sorbitan with ethylene oxide or propylene oxide, alkyl polyglycosides (APGs), ethers mixed with hydroxyalkyl and amine oxides. Preferred examples of alkoxylated alcohols and alkoxylated fatty alcohols are, for example, compounds of the general formula (I) R1R2 / °4^o4d^°^R3 where the variables are defined as follows: R1 is identical or different and is selected from hydrogen and linear Ci-Cio-alkyl, preferably identical in each case and ethyl and preferably in particular hydrogen or methyl, R2 is selected from C8-C22-alkyl, branched or linear, for example, n-CsHi?, n-CwH2i, n-Ci2H25, n-Cífe, n-CieHsa or n-CisHs?, R3 is selected from Ci-Cw-alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, sechexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl or isodecyl, m and n are in the range of zero to 300, where the sum of ny and m is at least one, preferably in the range of 3 to 50. Preferably, m is in the range of 1 to 100 and n is in the range of 0 to 30. In one embodiment, the compounds of General Formula (I) can be block copolymers or random copolymers, where block copolymers are preferred. Other preferred examples of alkoxylated alcohols are, for example, compounds of the general formula (II) where the variables are defined as follows: R1 is identical or different and is selected from hydrogen and linear Ci-Co-alkyl, preferably identical in each case and ethyl and preferably particularly hydrogen or methyl, R4 is selected from C6-C2o-alkyl, branched or linear, in particular, n-CsHv, n-CwH2i, n-Ci2H25, nC14H29, n-CieH33, n-CisHs?, a is a number in the range of zero to 10, preferably from 1 to 6, b is a number in the range of 1 to 80, preferably from 4 to 20, d is a number in the range of zero to 50, preferably from 4 to 25. The sum of a + b + d is preferably in the range from 5 to 100, with greater preference in the range from 9 to 50. The preferred examples of ethers mixed with hydroxyalkyl are compounds of the general formula (III) .OH R1 where the variables are defined as follows: R1 is identical or different and is selected from hydrogen and linear Ci-Cio-alkyl, preferably identical in each case and ethyl and preferably in particular hydrogen or methyl, R2 is selected from C8-C22-alkyl, branched or linear, for example, SO-C11H23, SO-C13H27, n-CsHv, n-CiH2i, n-Ci2H25, n-Ci4H29, n-OA6H33o n-Ci8H37, R3 is selected from C1 -Cis-alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, sechexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, isodecyl, n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl. The variables m and n are in the range of zero to 300, where the sum of ny and m is at least one, preferably in the range of 5 to 50. Preferably, m is in the range of 1 to 100 and n is in the range of 0 to 30. The compounds of General Formula (II) and (III) can be block copolymers or random copolymers, where block copolymers are preferred. Suitable additional nonionic surfactants are selected from di- and multiblock copolymers, which are composed of ethylene oxide and propylene oxide. Suitable additional nonionic surfactants are selected from ethoxylated or propoxylated sorbitan esters. Amine oxides or alkyl polyglycosides, especially linear C4-C16-alkyl polyglycosides and branched Cs-C1M-alkyl polyglycosides such as the compounds of Average General Formula (IV), are also suitable. where the variables are defined as follows: R5 is Ci-C4-alkyl, in particular ethyl, n-propyl or isopropyl, R6es -(CH2)2-R5, G1 is selected from monosaccharides with 4 to 6 carbon atoms, especially glucose and xylose, x is in the range of 1.1 to 4, where x is an average number. An overview of suitable additional non-ionic surfactants can be found in EP-A 0 851 023 and DE-A 198 19 187. Mixtures of two or more different non-ionic surfactants may also be present. Other surfactants that may be present are selected from amphoteric (zwitterionic) surfactants and anionic surfactants and mixtures of these. Examples of amphoteric surfactants are those that have both a positive and a negative charge on the same molecule under conditions of use. Preferred examples of amphoteric surfactants are the so-called betaine surfactants. Many betaine surfactants have a quaternized nitrogen atom and a carboxylic acid group per molecule. A particularly preferred example of an amphoteric surfactant is cocamidopropyl betaine (lauramidopropyl betaine). Examples of amide oxide surfactants are compounds of the general formula (V) R7R8R9N^O (V) wherein R7, R8, and R9 are independently selected from each other from aliphatic, cycloaliphatic, or C2-C4 alkylene Cio-C2o-alkylamido portions. Preferably, R7 is selected from C8-C2o-alkyl or C2-C4 alkylene Cio-C2o-alkylamido and both R8 and R9 are methyl. A particularly preferred example is lauryldimethyl aminooxide, sometimes also called lauramine oxide. An additional particularly preferred example is cocamidylpropyl dimethyl aminooxide, sometimes also called cocamidopropylamine oxide. Examples of suitable anionic surfactants include alkali metal and ammonium salts of Ce-Cis-alkyl sulfates, Cs-Cis-polyether sulfates of fatty alcohols, sulfuric acid hemiesters of C4-C12 ethoxylated alkylphenols (ethoxylation: 1 to 50 mol ethylene oxide / mol), C12-C18 alkyl sulfoesters of fatty acids, for example, C12-C18 fatty acid sulfomethyl esters, and Ci2-Ci8 alkylsulfonic acids of Cio-Ci8 alkylsulfonic acids. Preference is given to alkali metal salts of the aforementioned compounds, with sodium salts being particularly preferred. Additional examples of suitable anionic surfactants are soaps, for example, sodium or potassium salts of stearic acid, oleic acid, palmitic acid, ether carboxylates, and alkyl ether phosphates. Preferably, laundry detergent compositions contain at least one anionic surfactant. In one embodiment of the present invention, the inventive cleaning agents determined to be used as laundry detergent compositions may contain from 0.1 to 60% by weight of at least one surfactant, selected from anionic surfactants, amphoteric surfactants, and amine oxide surfactants. In one embodiment of the present invention, the inventive cleaning agents determined to be used for cleaning hard surfaces may contain from 0.1 to 60% by weight of at least one surfactant, selected from anionic surfactants, amphoteric surfactants, and amine oxide surfactants. In a preferred embodiment, the inventive cleaning agents do not contain any anionic detergent. Inventive cleaning agents comprise one or more bleaching catalysts. The bleaching catalysts can be selected from transition metal salts or transition metal complexes that enhance bleaching, such as, for example, manganese, iron, cobalt, ruthenium, or molybdenum-salene or carbonite complexes. Manganese, iron, cobalt, ruthenium, molybdenum, titanium, vanadium, and copper complexes with nitrogen-containing tripod ligands, as well as cobalt, iron, copper, and ruthenium amine complexes, can also be used as bleaching catalysts. Inventive cleaning agents may comprise one or more bleaching activators, for example, N-methylmorpholinium-acetonitrile salts (MMA salts), trimethylammonium acetonitrile salts, N-acylimides such as, for example, N-nonanoylsuccimide, 1,5-diacetyl-2,2-dioxohexahydro-1,3,5-triazine (DADHT) or quater nitrile (trimethylammonium acetonitrile salts). Other examples of suitable bleaching activators are tetraacetylethylenediamine (TAED) and tetraacetylhexylenediamine. The inventive cleaning agents comprise one or more corrosion inhibitors. In the present case, this is understood to include compounds that inhibit metal corrosion. Examples of suitable corrosion inhibitors are triazoles, in particular benzotriazoles, bisbenzotriazoles, aminotriazoles, alkylaminotriazoles, and phenol derivatives such as, for example, hydroquinone, pyrocatechol, hydroxyhydroquinone, gallic acid, phloroglucinol, or pyrogallol. In one embodiment of the present invention, the inventive cleaning agents comprise a total corrosion inhibitor in the range of 0.1 to 1.5% by weight. Inventive cleaning agents may comprise one or more enhancers, selected from organic and inorganic enhancers. Examples of suitable inorganic enhancers include sodium sulfate or sodium carbonate or silicates, in particular sodium disilicate and sodium metasilicate, zeolites, sheet silicates, in particular those of the formula α-Na₂S₂O₅, 3-Na₂S₂O₅ and β-Na₂S₂O₅, also fatty acid sulfonates, α-hydroxypropionic acid, alkali metal malonates, fatty acid sultanates, alkyl and alkenyl disuccinates, tartaric acid diacetate, tartaric acid monoacetate, oxidized starch, and polymeric enhancers, for example, polycarboxylates and polyaspartic acid. Examples of organic improvers are especially polymers and copolymers. In one embodiment of the present invention, the organic improvers are selected from polycarboxylates, for example, alkali metal salts of (meth)acrylic acid homopolymers and (meth)acrylic acid copolymers, partially or completely neutralized with alkali. Suitable comonomers for (met) are monoethylenically unsaturated dicarboxylic acids, such as maleic acid, fumaric acid, maleic anhydride, itaconic acid, and citraconic acid. A particularly suitable polymer is polyacrylic acid, preferably having an average molecular weight in the range of 2000 to 40,000 g / mol, and preferably 3,000 to 10,000 g / mol. It is also possible to use copolymers of at least one monomer from the group consisting of CaCw-mono- or C4-Cio-dicarboxylic monoethylenically unsaturated acids or anhydrides thereof, such as maleic acid, maleic anhydride, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, and citraconic acid, with at least one hydrophilic or hydrophobic monomer as listed below. Suitable hydrophobic monomers include, for example, isobutene, diisobutene, butene, pentene, hexene, and styrene; olefins with 10 or more carbon atoms or mixtures thereof, such as, for example, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-docosene, 1-tetracosene, and 1-hexacosene; C22-a-olefin; a mixture of C2o-C24-a-olefins; and polyisobutene, which has on average 12 to 100 carbon atoms per molecule. Suitable hydrophilic monomers include monomers with sulfonate or phosphonate groups, as well as non-ionic monomers with hydroxyl groups or alkylene oxide groups. Examples include: allyl alcohol, isoprene, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, methoxypolybutylene glycol (meth)acrylate, methoxypoly(propylene oxide-co-ethylene oxide) (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, ethoxypolybutylene glycol (meth)acrylate, and ethoxypoly(propylene oxide-ethylene oxide) (meth)acrylate. The polyalkylene glycols herein may comprise from 3 to 50 alkylene oxide units per molecule, in particular from 5 to 40 alkylene oxide units per molecule and especially from 10 to 30 alkylene oxide units per molecule. The monomers containing a sulfonic acid group particularly preferred herein are 1-acrylamido-1-propansulfonic acid, 2-acrylamido-2-propansulfonic acid, 2-acrylamido-2-methylpropansulfonic acid, 2-methacrylamido-2-methylpropansulfonic acid, 3-methacrylamido-2-hydroxypropansulfonic acid, allylsulfonic acid, metalylsulfonic acid, allyloxybenzenesulfonic acid, metalyloxybenzenesulfonic acid, 2-hydroxy-3-(2-propenyloxy)propansulfonic acid, 2-methyl-2-propen-1-sulfonic acid, styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl acrylate, 2-sulfoethyl methacrylate, 3-sulfopropyl methacrylate, sulfomethacrylamide, sulfomethylmethacrylamide and salts of said acids, such as sodium, potassium or ammonium salts thereof. Particularly preferred monomers containing a phosphonate group are vinylphosphonic acid and its salts. In addition, amphoteric polymers can also be used as enhancers. Inventive cleaning agents may comprise, for example, in the range, in total, from 10 to 50% by weight, preferably up to 20% by weight, of improver. In one embodiment of the present invention, the inventive cleaning agents may contain one or more commoderate particles. Inventive cleaning agents may comprise one or more antifoaming agents, selected, for example, from silicone oil and paraffin oils. In one embodiment of the present invention, the inventive cleaning agents comprise in total in the range of 0.05 to 0.5% by weight of antifoam. Inventive cleaning agents may comprise one or more enzymes. Examples of enzymes include lipases, hydrolases, amylases, proteases, cellulases, esterases, pectinases, lactases, and peroxidases. In one embodiment of the present invention, the inventive cleaning agents may comprise, for example, up to 5% by weight of enzyme, where 0.1 to 3% by weight is preferred. Such enzyme may be stabilized, for example, with the sodium salt of at least one C4-C5-carboxylic acid or C4-C5-dicarboxylic acid. Formates, acetates, adipates, and succinates are preferred. In one embodiment of the present invention, the inventive cleaning agents may comprise at least one zinc salt. The zinc salts may be selected from water-soluble and water-insoluble zinc salts. In this connection, within the context of the present invention, "water-insoluble" refers to those zinc salts that, in distilled water at 25°C, have a solubility of 0.1 g / L or less. Zinc salts that have greater water solubility are therefore referred to, within the context of the present invention, as "water-soluble zinc salts." In one embodiment of the present invention, the zinc salt is selected from zinc benzoate, zinc gluconate, zinc lactate, zinc formate, ZnCl2, ZnSCh, zinc acetate, zinc citrate, Zn(NOs)2, Zn(CH3SO3)2 and zinc gallate, preferably ZnCb, ZnSO4, zinc acetate, zinc citrate, Zn(NOs)2, Zn(CH3SO3)2 and zinc gallate. In another embodiment of the present invention, the zinc salt is selected from ZnO, aqueous ZnO, Zn(OH)2, and ZnCOs. Aqueous ZnO is preferred. In one embodiment of the present invention, the zinc salt is selected from zinc oxides with an average particle diameter (weight average) in the range of 10 nm to 100 pm. The zinc salt cation may be present in complex form, for example, forming complexes with ammonia ligands or water ligands, and in particular, may be present in hydrated form. For simplicity, within the context of the present invention, ligands are generally omitted if they are water ligands. Depending on how the pH of the mixture is adjusted according to the invention, the zinc salt may change. Therefore, for example, it is possible to use zinc acetate or ZnCl2 to prepare a formulation according to the invention, but at a pH of 8 or 9 in an aqueous environment it converts to ZnO, Zn(OH)2, or Aqueous ZnO, which can be present in a non-complex or complex form. Zinc salts may be present in inventive cleaning agents that are solid at room temperature. In such inventive cleaning agents, the zinc salts are preferably present in the form of particles having, for example, an average diameter (number average) in the range of 10 nm to 100 pm, preferably from 100 nm to 5 pm, as determined by X-ray scattering. Zinc salts may be present in inventive cleaning agents that are liquid at room temperature. In such inventive cleaning agents, zinc salts are preferably present in dissolved, solid, or colloidal form. In one embodiment of the present invention, the inventive cleaning agents comprise in total in the range of 0.05 to 0.4% by weight of zinc salt, depending in each case on the solids content of the cleaning agent in question. Here, the zinc salt fraction is given as zinc or zinc ions. From this, it is possible to calculate the counterion fraction. In one embodiment of the present invention, the inventive cleaning agents are free from heavy metals other than zinc compounds. Within the context of the present invention, this may be understood to mean that the inventive cleaning agents are free from those heavy metal compounds that do not act as bleaching catalysts, particularly iron and bismuth compounds. Within the context of the present invention, "free from" with respect to heavy metal compounds is to mean that the content of heavy metal compounds that do not act as bleaching catalysts is, in total, in the range of 0 to 100 ppm, determined by the leaching method and as a function of the solids content. Preferably, the inventive cleaning agents, other than zinc, have a heavy metal content below 0.05 ppm, as a function of the solids content of the formulation in question.Therefore, the zinc fraction is not included. Within the context of the present invention, heavy metals are considered to be all metals with a specific gravity of at least 6 g / cm³, except for zinc. In particular, heavy metals include metals such as bismuth, iron, copper, lead, tin, nickel, cadmium, and chromium. Preferably, the inventive cleaning agents comprise non-measurable fractions of bismuth compounds, i.e., for example, less than 1 ppm. Inventive cleaning agents are excellent for cleaning hard surfaces and fibers. The invention is illustrated by the following practical examples. General comments: Apparent density is determined in accordance with ISO 697 (2nd edition 1981-03-01). The amplitude-to-average-length ratio was determined using a CAMSIZER XT Retsch. Hygroscopicity was determined as follows: Approximately 5 g of the respective sample were placed in a Petri dish and its weight was determined. The Petri dish with the sample was placed in a conditioning cabinet at 38°C and 78% relative humidity. The weight was determined again after 1 hour, 3 hours, 6 hours, 24 hours, 48 ​​hours, etc. Each determination was carried out in duplicate. Starting materials: (A.1): trisodium salt of methylglycinediacetic acid (MGDA-Nas), provided as 40% by weight of aqueous solution (B.1): polyacrylic acid, 25 mol% neutralized with sodium hydroxide, Mw: 4,000 g / mol, determined by GPC and with reference to the free acid (B.2) random copolymer of acrylic acid and 2-acrylamido-2-methylpropansulfonic acid (AMPS), partially neutralized with sodium, pH value 5, Mw: 18,500 g / mol. I. Preparation of spray liquors, stage (a) 1.1 Preparation of spray liquor SL.1, stage (a.1) A container was charged with 15.28 kg of an aqueous solution of (A.1) (40% by weight) and 720 g of an aqueous solution of (B.1) (45% by weight). The spray liquor SL.1 thus obtained was vigorously stirred, then heated to 70°C and subjected to spray granulation. I.2 Preparation of spray liquor SL.2 A vessel was charged with 42.697 kg of an aqueous solution of (A.1) (40% by weight), 7.303 kg of MGDA-Nas granules (12% by weight moisture content), and 3.668 g of an aqueous solution of (B.2) (40% by weight). The spray liquor SL.2 thus obtained was stirred, then heated to 70°C and subjected to spray granulation. II. Spray granulation, stage (b) 11.1 Spray granulation of spray liquor SL.1, stage (b.1) A laboratory-scale granulator, commercially available as the Glatt Procell laboratory system with Vario 3 insert, was charged with 0.9 kg of solid spherical MGDA-Nas particles, 350 to 1000 µm in diameter, and 600 g of ground MGDA-Naa particles. 200 Nm³ / h of air at 165 to 168°C was blown from the bottom. A fluidized bed of MGDA-Nas particles was obtained. The SL.1 liquor was introduced by spraying 7 kg of SL.1 (70°C) per hour into the fluidized bed from the bottom through a two-fluid nozzle at an absolute nozzle pressure of 4.3 bar. Granules formed, and the bed temperature, corresponding to the surface temperature of the solids in the fluidized bed, was 95 to 101°C. Particles that were large enough (heavy) fell through the zigzag air classifier (operated at a relative pressure of 1.8 to 2 bar) and were continuously transferred to a sample bottle. Smaller (lighter) granules were blown through the recycler back into the fluidized bed adjacent to the air classifier. When approximately 1 L of granules had been collected in the sample bottle, it was replaced with a new one. The collected granules were sieved through a 1 mm mesh screen. Two fractions were obtained: coarse particles (diameter >1 mm) and value fraction (<1 mm). The coarse particles (diameter >1 mm) were ground together with the small amounts of value fraction using a hammer mill (Kinetatica Polymix PX-MFL 90D) at 4000 revolutions per minute (rpm) to a 2 mm mesh screen. The resulting powder was returned to the fluidized bed. Most of the value fraction, which was not ground, was discarded and collected. After consuming 10 kg of SL.1, a steady state was reached. Then, the <1 mm fraction was collected as inventive granules. The residual moisture of C-Gr.1 was determined to be 12.0%, with reference to the total solids content of the granule, and was determined by Karl-Fischer titration. In the example above, the 170°C hot air can be replaced by hot N2 which has a temperature of 170°C. II.2 Spray granulation of spray liquor SL.2, stage (b.2) A laboratory-scale granulator, commercially available as the Glatt Procell laboratory system with Vario 3 insert, was charged with 0.9 kg of solid spherical MGDA-Nas particles, 350 to 1000 µm in diameter, and 600 g of ground MGDA-Nas particles. 200 Nm³ / h of air at 170–175°C was blown from the bottom. A fluidized bed of MGDA-Nas particles was obtained. The SL.2 liquor was introduced by spraying 8 kg of SL.2 (70°C) per hour into the fluidized bed from the bottom through a two-fluid nozzle at an absolute nozzle pressure of 4.35 bar. Granules formed, and the bed temperature, corresponding to the surface temperature of the solids in the fluidized bed, was 95–101°C. Particles that were large enough (heavy) fell through the zigzag air classifier (operated at a relative pressure of 1.8 to 2 bar) and were continuously transferred to a sample bottle. Smaller (lighter) granules were blown through the recycler back into the fluidized bed adjacent to the air classifier. When approximately 1 L of granules had been collected in the sample bottle, it was replaced with a new sample bottle. The collected granules were sieved through a 1 mm mesh screen. Two fractions were obtained: coarse particles (diameter >1 mm) and value fraction (<1 mm). The coarse particles (diameter >1 mm) were ground together with the small amounts of value fraction using a hammer mill (Kinetatica Polymix PX-MFL 90D) at 4000 rpm (rounds per minute) through a 2 mm mesh screen. The resulting powder was returned to the fluidized bed. Most of the value fraction, which was not ground, was discarded and collected. The <1 mm middle fraction was collected as comparative granule C-Gr.2. The residual moisture of C-Gr.2 was determined to be 12.0%, with reference to the total solids content of the granule. In the example above, the 170°C hot air can be replaced by hot N2 which has a temperature of 170°C. III. Treatment in a grid mixer, stage (c), general protocol III.1 Treatment of C-Gr.1 A Lódige MK 5 mixer (total volume: 5 liters) was charged with 1885 g of C-Gr.1 granules. The Lódige mixer was then operated at Fr in the range of 2 to 3 at room temperature for 16 minutes. Fines were removed by sieving through a 100 µm mesh. The resulting granules were Gr.1. The residual moisture content was 12.0% by weight, and the width-to-average length ratio (b / l) was 0.793. III.2 Treatment of C-Gr.2 A Lodige MK 5 mixer (total volume: 5 liters) was charged with 1885 g of C-Gr.2 granules. The Lodige was then operated at room temperature at Fr in the range of 2 to 3 for 16 minutes. Fines were removed by sieving through a 100 µm mesh. The resulting granules were Gr.2. The residual moisture content was 12.0% by weight, and the amplitude-to-average-length ratio was 0.795. III.3 Physical characterization of the respective granules Hygroscopicity: the ability of granules to absorb moisture under specific conditions. Five-g samples of granules were placed in a conditioning cabinet at 38°C and 78% relative humidity. Hygroscopicity was measured after 24 hours. Hygroscopicity [%]= (M2-M0)x100 / M1 M0 = weight of the empty Petri dish (g) M1 = initial weight (g) M2 = final weight (g) Apparent density: The mass in grams of a product that occupies the volume of one milliliter under specific conditions, measured according to ISO 697. The collection container, prepared according to ISO 697, was placed under a funnel. The funnel's opening was closed using a cover flap. The funnel was then filled to the top edge with the sample, the cover flap was quickly removed, and the contents of the funnel were poured into the collection container. Any excess granules were wiped off the collection container as it was removed. The container was then cleaned and its weight determined. Apparent density [g / mL] = (M1 -M0) / V M1 = mass of full collection container (g) M0 = mass of empty collection container (g) Table 1: Apparent density and hygroscopicity of inventive and comparative granules C-Gr.1 Gr.1 C-Gr.2 Gr.2 MGDA-Nas content [%] 77 77 78 78 Apparent density (g / L) 774 817 756 802 Hygroscopicity [%] 19 18 16 15 The MGDA content refers to the active matter and was determined by potentiometric titration with FeCh. From the inventive granules, example detergent compositions for automatic dishwasher detergents can be formulated by mixing the respective components according to Table 2. From the comparative granules, comparative detergent compositions for automatic dishwasher detergents can be formulated by mixing the respective components according to Table 2. Table 2: Example detergent compositions for automatic dishwashers All quantities in g / sample ADW.1 ADW.2 ADW.3 either Gr.1, Gr.2, C-Gr.1 or C-Gr.2 30 22.5 15 Protease 2.5 2.5 2.5 Amylase 1 1 1 n-Ci8H37-O(CH2CH2O)9H 5 5 5 Sodium percarbonate 10.5 10.5 10.5 TAED 4 4 4 Na2CO3 19.5 19.5 19.5 Sodium citrate dihydrate 15 22.5 30 HEDP 0.5 0.5 0.5 ethoxylated polypropyleneimine, 20 EO / NH groups, Mn: 30,000 g / mol optionally: 0.1 optionally: 0.1 optionally: 0.1

Claims

1. A process for preparing a granule containing (A) at least one chelating agent selected from alkali metal salts of methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS) and, optionally, (B) at least one homopolymer or copolymer of (meth)acrylic acid, partially or completely neutralized with alkali, wherein said process comprises the steps of (a) providing an aqueous solution or slurry containing chelating agent (A) and, if applicable, (co)polymer (B), (b) removing most of said water by spray granulation in a fluidized bed, thereby providing a granule, (c) treating the granule resulting from step (b) with air or an inert gas in a vessel at least a portion of which rotates about a horizontal axis and wherein said vessel is selected from paddle mixers, drop mixers, and grate mixers.

2. The process according to claim 1, wherein, in step (b), a gas with an inlet temperature of at least 125°C is used.

3. The process according to claim 1 or 2, wherein the weight ratio of the chelating agent (A) and the copolymer (B) is in the range of 1,000:1 to 7.5:

1.

4. The process according to any of the preceding claims, wherein step (b) is carried out using a two-fluid nozzle.

5. The process according to any of the preceding claims, wherein step (c) is carried out during a period of 1 minute to 5 hours.

6. The process according to any of the preceding claims, wherein step (c) is carried out in a free-fall mixer.

7. The process according to any of the preceding claims, wherein step (c) is followed by a step (d) that includes the removal of fines.

8. The process according to any of the preceding claims, wherein the (co)polymer (B) is selected from (meth)acrylic acid copolymers and a comonomer having at least one sulfonic acid group per molecule.

9. The process according to claim 8, wherein the comonomer having at least one sulfonic acid group per molecule is 2-acrylamido-2-methylpropansulfonic acid.

10. A granule containing (A) at least one chelating agent selected from alkali metal salts of methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS), (B) at least one (meth)acrylic acid copolymer with a monomer having at least one sulfonic acid group per molecule, partially or completely neutralized with alkali, in a weight ratio of (A):(B) from 2:1 to 1,000:1, IVIA to ZUZZ.UU / ¿14 wherein said granule contains at least 75% by weight of chelating agent (A), and wherein said granule has a width-to-length ratio in the range of 1:1 to 1:0.

75.

11. The granule according to claim 10, having a residual moisture content in the range of 1 to 20% by weight.

12. The granule according to claim 10 or 11, having an average diameter in the range of 0.1 mm to 2 mm.

13. The granule according to any of claims 10 to 12, wherein the comonomer having at least one sulfonic acid group per molecule is 2-acrylamido-2-methylpropansulfonic acid.

14. The granule according to any of claims 10 to 13, wherein the chelating agent (A) is the trisodium salt of MGDA.

15. The use of a granule according to any of claims 10 to 14 for the preparation of a cleaning agent for fibers or hard surfaces, wherein said cleaning agent contains at least one peroxy compound selected from percarbonates, persulfates and perborates.