A highly efficient stable bleach catalyst and bleach activator composite particle for use in a dishwashing detergent and a method of making the same

Abstract

The application provides a high-efficiency stable bleaching catalyst and bleaching activator composite particle for a dishwashing agent, which is granulated from a bleaching activator, a bleaching catalyst, a binder, an antioxidant, a PH buffer and other auxiliaries; and a preparation method for the composite particle, which comprises dry mixing, wet mixing, granulation, drying and sieving. The application has the advantages that the synergistic effect of low-temperature catalysis of an oxygen-based bleaching agent in a bleaching process and preparation and bleaching of peroxyacetic acid is effectively improved; and the granulation process combining dry and wet methods avoids the dust safety problem of a pure dry granulation route and effectively improves the one-way yield of the granulation process.

Description

Technical Field

[0001] This invention relates to the field of oxygen-based bleaching catalyst and bleaching activator particle preparation technology, specifically to a high-efficiency and stable composite particle of bleaching catalyst and bleaching activator for dishwashing detergent and its preparation method. Background Technology

[0002] Dishwashing is a global hygiene practice. A global survey report led by Rainer et al. of the University of Bonn (Stamminger R, Berkholz P. Automatic dishwashers are superior to hand dishwashers—a global analysis [J]. China Detergent Industry, 2020, (09): 159-164) revealed that automatic dishwashers have significant advantages over hand washing in terms of water, energy, and time consumption. However, whether hand washing or machine washing, oxygen-based bleaching agents need to be added to the dishwasher formula to ensure the clean and bright surface of the dishes after washing, thereby enhancing their cleaning and sterilization effects. Under the global trend of carbon reduction and emission reduction, the dishwashing process is gradually developing towards low-temperature washing. When the washing temperature is below 60°C, the dishwasher formula needs to be further coupled with bleaching activators or bleaching catalysts to enhance the washing effect of the bleach.

[0003] Currently, bleaching activators are mainly amide-based, alkyloxyloxy-based, cationic caprolactam-based, guanidine-based, and cyanide-based activators. These activators react with hydrogen peroxide in alkaline aqueous solutions to generate hydrogen peroxide radicals (HOO-), which in turn produce peroxyacids with higher redox potentials and stronger oxidizing power than hydrogen peroxide. These peroxyacids exhibit stronger bleaching and bactericidal effects at lower temperatures. Bleaching catalysts are mainly enzyme-mimicking catalysts such as metalloporphyrin complexes, macrocyclic polyamine metal complexes, Schiff base metal complexes, and metal phthalocyanine coordination compounds. Under low-temperature conditions, these catalysts can effectively promote the ionization of hydrogen peroxide to generate peroxyacid radicals. Therefore, bleaching activators and bleaching catalysts significantly improve and enhance the low-temperature bleaching efficiency of oxygen-based bleaching agents, and have become a major development direction for daily chemical bleaching products under the current trend of energy conservation and emission reduction.

[0004] To achieve both efficient low-temperature rinsing and sterilization, dishwashing detergents typically require the simultaneous use of three components: an oxygen-based bleaching agent, a bleaching activator, and a bleaching catalyst. The bleaching catalyst, under low-temperature conditions, promotes the generation of peroxide free radicals from the oxygen-based bleaching agent, which further react with the bleaching activator to produce peroxide organic acids, enhancing the sterilization and stain removal capabilities. To achieve the synergistic effect of the bleaching activator and the bleaching catalyst, while ensuring the accurate addition of the effective components to the dishwashing detergent and maintaining their stability and effectiveness, researchers have conducted a series of studies on granulation methods and technologies containing bleaching activators and / or bleaching catalyst particles. For example, Unilever pioneered the development of low-temperature bleaching catalysts, revealing in its patent EP0458397 that manganese-based transition metal complexes can effectively enhance the cleaning effect of oxygen-based bleaching agents on tea stains at 10-40℃, with an addition amount of only 0.001wt%-0.05wt% in the detergent. To ensure the accuracy, uniformity, and stability of low-dose addition of manganese-based complex catalysts in detergents, patent EP0544440 (CN1073477) proposes a method for preparing non-fragile composite particles containing manganese-based complex bleaching catalysts. The composite particles are a mixture of 0.5-8 wt% (2-5 wt%) manganese complex catalyst, 0-90 wt% (50-90 wt%) inert additives, and 5-91 wt% (5-30 wt%) binder, and are granulated using a disc granulator, fluidized bed, mixer, compaction equipment, and mixing granulation equipment. Warwick, in its patent US5433881, proposed a composite bleaching activator for low-temperature and even cold-washing applications in daily chemical cleaning and its preparation method. It pointed out that by adding not less than 2 wt% of a disintegrant composed of sodium organophosphonate (sodium ethylenediaminetetramethylenephosphonate or diethylenetriaminepentamethylenephosphonic acid) and sodium sulfate (sodium sulfate) to the bleaching activator granule formulation, the peracetic acid release rate and bleaching ability of the bleaching activator granules under low-temperature conditions of 20°C can be effectively improved.

[0005] The preparation of bleaching activator composite particles involves dry mixing TAED bleaching activator with sodium carboxymethyl cellulose, followed by wet mixing with an aqueous solution containing a composite disintegrant of organophosphonates and sodium sulfate. The mixture is then agglomerated, granulated, fluidized bed dried, and sieved to obtain a product with a particle size of 300μm-1500μm. Clariant, in its patent US8883704, proposed a method using TAED or DOBA as a bleaching activator, manganese salts or manganese complexes as a bleaching catalyst, fatty alcohol alkoxy compounds as a binder, and organic acids as stabilizers to prepare composite bleaching particles. The particle composition includes 50wt%-85wt% bleaching activator, 0.1-20wt% bleaching catalyst, 8-20wt% organic acid, and 1-20wt% binder. The particle formulation components are premixed, melted into a viscous state, granulated using a disc granulator, and then cooled and sieved to obtain bleaching particles of the target size. Welly Chemicals states in its patent US9902921B1 that due to the high efficiency of its bleaching catalyst, its addition amount in detergent / washing blocks is 0.02-0.08 wt%. To ensure the stability and uniform dispersion of bleaching catalysts in detergents, Weil Chemical proposed an anhydrous dry roller pressing method for preparing bleaching catalyst particles. The particle formulation consists of 2-10 wt% of a transition metal coordination compound containing trimethyltriazacyclononane or coupled triazacyclononane as a ligand and 90-98 wt% of one or more copolymer or homopolymer acrylic polymers with a pH of 4-8 as a binder. The dry-prepared bleaching catalyst particles exhibit good storage stability and bleaching enhancement effect in dishwashing detergent formulations. Furthermore, patent US9902922B2 proposes an anhydrous dry roller pressing method for preparing composite particles of bleaching catalyst and bleaching activator. The particle formulation consists of 65-85 wt% bleaching activator, 0.05 wt%-6 wt% bleaching catalyst, and 10-30 wt% binder. The particles exhibit good stability in dishwashing detergent formulations. Nourion disclosed in its patent WO2016 / 005392 a multi-layered core-shell granule containing enzymes and bleaching catalysts for use in dishwashing tablets, designed to reduce rinsing temperature and improve cleaning performance. The granule consists of an enzyme-containing core, a first coating layer containing a mixture of bleaching catalysts, a second coating layer mainly composed of soluble salts, and a third coating layer made of natural or synthetic polymer materials to improve the storage stability of the granules in dishwashing detergent. The stability results of its implementation examples show that the multi-layered enzyme and bleaching catalyst composite granules have good stability and cleaning effect in dishwashing detergent formulations.

[0006] However, the above preparation methods still have obvious drawbacks: For example, Unilever and Warwick use bleaching catalysts or bleaching activators as active ingredients for separate granulation. On the one hand, the granulation process uses a large amount of inert carriers, resulting in fewer active ingredients, and the two independent particles occupy a large volume in the dishwashing liquid, leading to high costs for granulation and application. On the other hand, it is difficult to ensure that the two are released simultaneously during the washing process when adding two independent particles, making it difficult to realize the synergistic effect of the bleaching catalyst and bleaching activator during the washing process, resulting in poor rinsing effect. Clariant et al. use fatty alcohol alkoxy compounds as binders and manganese-based nitrogen heterocyclic complexes as bleaching catalysts, and granulate them after molten mixing. On the one hand, transition metal organometallic compounds, especially manganese-based complexes, are prone to redox reactions with hydroxyl groups in primary, secondary, and tertiary alcohols, leading to deactivation. Therefore, natural or synthetic polymers with hydroxyl groups cannot be used in the granulation process. On the other hand, the agglomeration is achieved by melting the binder through heating during the granulation process. Excessive melting temperature can also easily lead to decomposition of the complex, and there are problems with high process energy consumption and difficulty in material transportation. The multi-layer core-shell strategy proposed by Noryon et al. ensures the stability of the composite particles in dishwashing detergent, but the multi-layer structure cannot be released simultaneously, affecting the synergistic effect of the washing process; moreover, the preparation process of the multi-layer core-shell structure is complex. Weylchem, based on acrylic binders, prepares particles containing bleaching catalysts and co-particles of bleaching catalyst and bleaching activator through dry granulation. On the one hand, it avoids the redox reaction of the catalyst caused by hydroxyl-containing polymers, and on the other hand, it avoids the decomposition of the catalyst caused by the molten state or wet drying process; however, the binder bonding is weak in the dry granulation process, the particle strength is low, and it is easy to wear after mixing and packaging. In addition, the amount of binder used in the dry granulation process is high, and the effective component is low. At the same time, the dry granulation process generates a lot of dust, requires high-end equipment, and has a high potential safety risk index.

[0007] Therefore, there is an urgent need to develop a highly efficient and stable composite particle of bleaching catalyst and bleaching activator and its reliable and safe preparation method to solve a series of problems existing in the above-mentioned products and preparation methods, such as low synergy in the washing process of particle products, poor product stability, and safety issues in the granulation process. Summary of the Invention

[0008] To address the aforementioned problems, this invention proposes a composite particle of bleaching catalyst and bleaching activator with high efficiency, stability, and synergistic catalytic activation, as well as a safe and simple preparation method, from multiple perspectives including process formulation, granulation process, and product stability.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution: A highly efficient and stable composite particle of bleaching catalyst and bleaching activator for dishwashing detergent and its preparation method are disclosed. The composite particle is granulated from a bleaching activator, a bleaching catalyst, a binder, an antioxidant, a pH buffer, and other additives. The mass percentage of each component in the composite particle is as follows: bleaching activator 90-96 wt%, bleaching catalyst 0-10%, binder 0-10 wt%, antioxidant 0-5 wt%, pH buffer 0-5 wt%, other additives 0-2 wt%, and moisture content 0-1 wt%. Preferably, the bleaching activator 90-92 wt%, bleaching catalyst 0.5-5 wt%, binder 2-6 wt%, antioxidant 0.1-2 wt%, pH buffer 0.1-1 wt%, other additives 0-1 wt%, and the moisture content of the prepared composite particle is less than 0.5 wt%.

[0010] The bleaching activator mentioned above mainly acts as a precursor of peroxy organic acids. During the washing process, it reacts with free radicals generated by oxygen-based bleaching agents to produce peroxy organic acids, thereby enhancing the bleaching, sterilization, and stain removal capabilities of the washing process. The bleaching activators include polyalkylimide diamines (such as tetraacetylethylenediamine (TAED)), acylated triazine derivatives (such as 1,5-diacetyl-2,4-dioxane-1,3,5-triazine (DADHT)), acylated glucosamine (such as tetraacetylglucosamine (TAGU)), N-imides (such as N-nonanoylsuccinimide (NOSI)), acyloxysulfonates (such as N-nonanoyloxy or lauroyloxybenzenesulfonate (NOBS or LOBS)), acyloxycarboxylic acids, nonanoyloxy or decanoyloxybenzoic acid (NOBA or DOBA), carboxylic anhydrides (such as phthalic anhydride), acylated polyols (such as triacetylglycerol or acetylated sorbitol), acylated sugar derivatives (such as pentaacetyl glucose (PAG) or acetyllactone), N-alkylated glucosamine and gluconic acid lactone, N-acylated lactams (such as N-benzoylcaprolactam), etc. The bleaching activator is preferably composed of one or more substances selected from tetraacetylethylenediamine (TAED), sodium nonanoyloxybenzenesulfonate (NOBS), sodium lauroyloxybenzenesulfonate (LOBS), nonanoyloxybenzoic acid (NOBA), and decanyloxybenzoic acid (DOBA). More preferably, the bleaching activator is composed of one or more substances selected from tetraacetylethylenediamine (TAED), sodium nonanoyloxybenzenesulfonate (NOBS), and decanyloxybenzoic acid (DOBA). Even more preferably, the bleaching activator is composed of tetraacetylethylenediamine, or a combination of tetraacetylethylenediamine and sodium nonanoyloxybenzenesulfonate (NOBS), or a combination of tetraacetylethylenediamine, sodium nonanoyloxybenzenesulfonate (NOBS), and decanyloxybenzoic acid (DOBA). The bleaching activator component accounts for 90-98 wt% of the bleaching activator and bleaching catalyst particles, preferably 90-96 wt%, and more preferably 90-92%.

[0011] The bleaching catalyst described herein primarily functions as a low-temperature catalyst for oxygen bleaching agents, lowering the energy barrier in the peroxy free radical generation process, promoting the generation of peroxy free radicals, and generating peroxy organic acids with the bleaching activator, thereby enhancing the bleaching, stain-removing, and bactericidal effects and achieving a synergistic effect. The bleaching catalyst is primarily a transition metal coordination compound with a transition metal as the central atom and a polydentate macrocyclic organic molecule with lone pairs of electrons (N, NR, PR, O, or S atoms) as ligands. Preferably, the bleaching catalyst is a coordination compound formed with Fe, Cu, Co, or Mn as the central atom and polydentate macrocyclic organic molecules with lone pairs of electrons (N, NR, or O atoms) as ligands. Further preferably, Fe... 3+ Cu2+ Co 2+ Mn 3+ Mn 4+ The bleaching catalyst uses a metal ion as the central atom and a polydentate nitrogen-containing organic molecule as the ligand, as shown in the following molecular schematic: 1,4,7-trimethyl-1,4,7-triazacyclononane (A), 1,2-bis(4,7-dimethyl-1,4,7-triazacyclononane-1)-ethane (B), 1,8-dimethyl-4,12-bridged-1,4,8,12-tetraazacyclotetradecane (C), porphyrin parent material porphyrin (D) and its derivatives, pentadentate nitrogen-containing ligands (E, F), Schiff base (G) and its derivatives, 2,2':6',2''-terpyridine (H) and its derivatives; more preferably, Mn is used. 3+ Mn 4+ Mononuclear or polynuclear transition metal coordination compounds, with a metal ion as the central atom and 1,4,7-trimethyl-1,4,7-triazacyclononane (A) or 1,2-bis(4,7-dimethyl-1,4,7-triazacyclononane-1)-ethane (B) as ligands, or Fe 3+ The bleaching catalyst is a mononuclear or polynuclear transition metal coordination compound consisting of a metal ion as the central atom, a porphyrin parent compound (Porphyrin (D) and its derivatives), and pentadentate nitrogen-containing ligand molecules (E, F) as ligands. The bleaching catalyst component comprises 0-10 wt% of the bleaching activator and bleaching catalyst particles, preferably 0.5-8 wt%, and more preferably 0.5-5%.

[0012]

[0013] The binder primarily functions as an adhesive and agglomerator during the granulation process of the bleaching catalyst and bleaching activator, thereby enhancing particle strength and wear resistance. The binder is mainly a water-soluble synthetic polymer binder without hydroxyl groups, such as fatty acids, acrylic polymers or copolymers, povidones or copovidones. The fatty acid binder is an organic fatty acid with 8-22 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, and mixtures thereof. The acrylic polymer or copolymer is a polymeric material formed by polymerizing acrylic acid as the main monomer with monomers such as methacrylic acid, acrylates, methacrylates, and maleic anhydride, including polyacrylic acid, acrylic acid-methacrylic acid copolymers, acrylic acid-acrylate copolymers, acrylic acid-methacrylate copolymers, and acrylic acid-maleic anhydride copolymers. The povidone or copovidone binder is a polyacrylic acid polymer prepared by polymerizing vinylpyrrolidone as a monomer, or a copovidone polymer prepared by copolymerizing vinylpyrrolidone with vinyl acetate. The adhesive is preferably an acrylic polymer, an acrylic-methacrylic acid copolymer, an acrylic-maleic anhydride copolymer, or an acrylic-methacrylic acid-maleic anhydride copolymer obtained by polymerization of acrylic acid, methacrylic acid, and maleic anhydride as monomers; the adhesive is further preferably an acrylic polymer or an acrylic-maleic anhydride copolymer with a relative molecular weight of 2000-70000 g / mol; the adhesive is even more preferably an acrylic-maleic anhydride copolymer and its sodium salt with a relative molecular weight of 20000-50000 g / mol, especially with a relative molecular weight of 30000-40000 g / mol, obtained by copolymerization of 50-90 wt% acrylic monomer and 10-50 wt% maleic anhydride monomer.

[0014] The binder component accounts for 0-10 wt% of the bleaching activator and bleaching catalyst particles, preferably 2-8 wt%, and more preferably 2-6%.

[0015] The antioxidants described herein are primarily used to slow down or prevent the bleaching catalyst from undergoing redox reactions with other active molecules, leading to partial or complete inactivation. The antioxidants may be inorganic salts such as sulfites, thiosulfates, isoascorbic acid salts, ascorbic acid salts, or nitrites; or organic acids such as methionine, cysteine, propyl gallate, tert-butylhydroquinone, tocopherol, thiodipropionic acid, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), or tannic acid. Preferably, the antioxidants are one or more mixtures of isoascorbic acid salts or ascorbic acid salt vitamin antioxidants, methionine or cysteine ​​antioxidants, or butylated hydroxytoluene or butylated hydroxyanisole phenolic antioxidants; further preferably, they are one or more ascorbic acid salt vitamin antioxidants or methionine amino acid antioxidants; and even more preferably, they are ascorbic acid-vitamin antioxidants.

[0016] The antioxidant component accounts for 0-5 wt% of the bleaching activator and bleaching catalyst particles, preferably 0.1-4 wt%, and more preferably 0.5-2 wt%.

[0017] The pH adjuster is mainly used to adjust the pH value of the particles between 4 and 6.5, maintaining an acidic atmosphere to ensure the stability of the bleaching activator and bleaching catalyst particles in the dishwasher detergent coating environment. The acidic buffer component mainly consists of a mixture of weak acids and their corresponding salts, and is at least partially present in the form of weak acids. The pH adjuster includes phosphoric acid and its phosphates, polyacrylic acid or polyacrylic acid derivatives and their partially neutralized salts, and small molecule organic acids and their salts (citric acid and its disodium citrate). More preferably, the pH adjuster is a combination or mixture of two of the following: polyacrylic acid, partially neutralized polyacrylic acid and its copolymers, citric acid, and sodium citrate. Even more preferably, the pH adjuster is a pH buffer system composed of citric acid and sodium citrate.

[0018] The pH adjuster component accounts for 0-5 wt% of the bleaching activator and bleaching catalyst particles, preferably 0.1-3 wt%, and more preferably 0.1-2 wt%.

[0019] The other additives mainly include inert fillers, such as inorganic salts like sodium sulfate and sodium chloride, and functional indicator additives such as pigments. The proportion of these other components in the bleaching activator and bleaching catalyst particles is 0-1 wt%.

[0020] The preparation method of the mixture of bleaching activator and bleaching catalyst particles is mainly achieved through the following steps, methods, and equipment: Dry mixing: The bleaching activator, bleaching catalyst, binder, antioxidant, pH adjuster, and other additives are added to a dry mixing machine in a predetermined ratio to mix the components evenly; Wet mixing: The material that has been evenly mixed by dry mixing is transferred to a wet mixing machine, and a certain amount of water or an aqueous solution containing some functional additives is added according to a certain water-to-solid ratio for further wet mixing to promote uniform mixing and generate some viscosity; Granulation: The material that has been evenly mixed by wet mixing is further passed through a granulator to obtain bleaching activator and bleaching catalyst particles of a certain size; Drying: The wet bleaching activator and bleaching catalyst particles obtained by the granulator are further dried by a dryer to reduce and control the moisture content of the composite particles; Sieving: The dried bleaching activator and bleaching catalyst particles are further sieved to prepare composite particles of bleaching activator and bleaching catalyst within the target size range, and then packaged.

[0021] The dry mixing machine is preferably a horizontal ribbon mixer, a plow-type mixer, a gravity-free twin-shaft paddle mixer, a ribbon conical mixer, or a double-helix conical mixer or a triple-helix conical mixer; a double-helix conical mixer or a triple-helix conical mixer is particularly preferred. The dry mixing time is preferably 10-60 minutes, and particularly preferably 20-30 minutes.

[0022] The wet mixer is preferably a kneader, a plow-type wet mixer, a horizontal ribbon wet mixer, or a planetary wet mixer; a kneader or plow-type wet mixer with jacketed temperature control is particularly preferred. The liquid-to-solid ratio is preferably 5-20%, and particularly preferably 8-15%. The wet mixing time is preferably 5-30 minutes, and particularly preferably 10-20 minutes.

[0023] The pellet mill is preferably a swing-type pellet mill, a rotary extrusion pellet mill, a twin-screw extrusion pellet mill, or a high-speed mixing pellet mill; a twin-screw extrusion pellet mill or a high-speed mixing pellet mill is particularly preferred. The pellet size is preferably 0.25~2.0mm, and particularly preferably 0.4~1.6mm.

[0024] The drying process is preferably carried out using an oven, belt dryer, moving bed dryer, or fluidized bed dryer; fluidized bed dryer is particularly preferred. The drying temperature is preferably a temperature that controls the bed temperature, ideally between 50°C and 100°C, preferably between 60°C and 90°C, and particularly preferably between 70°C and 80°C.

[0025] The particle size of the target product after screening is preferably controlled within 0.1~1.6mm, more preferably within 0.2~1.2mm, and even more preferably within 0.3~1.0mm.

[0026] The granulation method described above can achieve a yield of 60-90% for bleaching activator and bleaching catalyst particles in a single granulation process, and can be further optimized to a yield of 70-80%.

[0027] Compared with the prior art, the present invention has the following advantages: A highly efficient and stable composite particle of bleaching catalyst and bleaching activator for dishwashing detergent and its preparation method are disclosed. Firstly, this invention solves the problem of low effective component content in particles caused by the extensive use of inert additives and binders in single catalyst particle granulation and dry granulation processes. Secondly, the composite granulation of bleaching activator and bleaching catalyst effectively enhances the low-temperature catalysis of oxygen-based bleaching agents and the synergistic effect of peracetic acid preparation and bleaching during the bleaching process. Thirdly, in terms of granulation formulation, the optimized binder and functional additives prevent the bleaching catalyst from deactivating due to reduction reactions during storage. Furthermore, the combined dry and wet granulation process avoids the dust safety issues associated with pure dry granulation and effectively improves the single-pass particle yield during the granulation process.

[0028] Specifically, based on the excellent compound stability of the bleaching activator and bleaching catalyst components, a dry-wet combined granulation process is used to form single composite particles of the bleaching activator and bleaching catalyst components. This not only avoids the problem of low effective ingredient content caused by the use of large amounts of binders or additives in the granulation process of a single component, but also enables the simultaneous dissolution and release of the bleaching activator and bleaching catalyst during the washing and bleaching process, which helps to quickly generate peroxy organic acids and improve bleaching and sterilization capabilities. In the granulation process and formulation, synthetic or natural polymer binders without hydroxyl active functional groups are further optimized. By adjusting the atmosphere of the composite particles, the stability problem of the composite particles of bleaching activator and bleaching catalyst in detergent powder is not only solved, but also the particle yield and particle strength are improved during the granulation process, avoiding powder dust and safety issues during granulation. Detailed Implementation

[0029] The embodiments of the present invention will now be described in further detail.

[0030] Comparative Case 1 (Synthetic Polymers Containing Hydroxyl Groups) Clariant patent US8883704 describes the use of 3.5 kg of TAED bleaching activator and 0.1 kg of Mn. ⅣThe catalyst 2(μ-O)3(Me-TACN)2(PF6)2.H2O, 400g of citric acid, and 1kg of Clariant Genapol T500 fatty alcohol alkoxy compound binder were mixed in a 10L screw dry mixer for 20 minutes until homogeneous. The homogeneous mixture was then transferred to a 10L jacketed kneader. The temperature inside the kneader was raised to 70-75°C using a heating medium in the jacket. The Genapol T500 binder melted and generated binding force, and the mixture was thoroughly mixed in the kneader for 15 minutes. The homogeneous mixture was then extruded and granulated using a disc granulator. After cooling, the granules were sieved. 2.0kg of orange-red composite granules of bleaching activator and bleaching catalyst with a target size of 0.3mm-1.2mm were obtained, with a single-pass yield of approximately 40%. Notably, a distinct amine odor was produced during the heating and fitting process in the kneader, which is preliminarily inferred to be caused by the thermal decomposition of some catalyst.

[0031] Compare with Case 2 (dry granulation process)

[0032] In Example 3 of Weil Chemical's patent US9902922B2, 3.75 kg of TAED bleaching activator and 0.1 kg of Mn were used. Ⅳ The catalyst 2(μ-O)3(Me-TACN)2(PF6)2.H2O and 1.15 kg of BASF Sokalan CP5 polyacrylic acid binder were mixed in a 10L screw dry mixer for 20 minutes to ensure thorough and uniform mixing. The uniformly mixed material was then fed into an integrated roller press dry granulator, where it underwent roller pressing, crushing, granulation, and sieving in sequence. After sieving, 1.75 kg of composite particles of bleaching activator and bleaching catalyst with a target size of 0.3 mm to 1.2 mm were obtained, with a single-pass yield of approximately 35%.

[0033] Comparative Case 3 (Hydroxyl-containing natural polymer materials)

[0034] 4.6 kg of TAED bleaching activator and 0.1 kg of Mn were added. ⅣThe catalyst 2(μ-O)3(Me-TACN)2(PF6)2.H2O, 0.075 kg of citric acid, 0.025 kg of ascorbic acid, and 0.2 kg of sodium carboxymethyl cellulose binder were added to a 10L screw dry mixer and mixed for 20 minutes until fully homogeneous. The homogeneous mixture was then transferred to a kneader, and 0.75 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 15%. The mixture was kneaded for 15 minutes until homogeneous. The homogeneous mixture was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the bed temperature controlled at 55°C. The fluidized bed-dried granules were sieved, and 3.45 kg of composite granules of bleaching activator and bleaching catalyst with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 69%.

[0035] Case 1

[0036] 4.6 kg of TAED bleaching activator and 0.1 kg of [Mn] were added. Ⅳ The catalyst 2(μ-O)3(Me-TACN)2](PF6)2.H2O, 0.075 kg of citric acid, 0.025 kg of ascorbic acid, and 0.2 kg of acrylic acid-maleic anhydride copolymer sodium salt were added to a 10L screw dry mixer and mixed for 20 minutes until fully mixed. The uniformly mixed material was then transferred to a kneader, and 0.5 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 10%. The mixture was kneaded for 15 minutes until uniform. The uniformly kneaded material was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the fluidized bed temperature controlled at 55-60℃. The fluidized bed-dried granules were sieved, and approximately 3.5 kg of composite granules of bleaching activator and bleaching catalyst with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 70%.

[0037] The bleaching activator components in Cases 1 to 4 were, in order, TAED, NOBS, DOBA, and a mixture of 50wt% TAED, 25wt% NOBS, and 25wt% DOBA.

[0038] Case 2 4.6 kg of NOBS bleaching activator and 0.1 kg of [Mn] were added. ⅣThe catalyst 2(μ-O)3(Me-TACN)2](PF6)2.H2O, 0.075 kg of citric acid, 0.025 kg of ascorbic acid, and 0.2 kg of acrylic acid-maleic anhydride copolymer sodium salt were added to a 10 L screw dry mixer and mixed for 20 minutes until fully homogeneous. The homogeneous mixture was then transferred to a kneader, and 0.5 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 10%. The mixture was kneaded for 15 minutes until homogeneous. The homogeneous mixture was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the fluidized bed temperature controlled at 55-60 °C. The fluidized bed-dried granules were sieved, and approximately 3.2 kg of composite bleaching activator and bleaching catalyst particles with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 64%.

[0039] Case 3

[0040] 4.6 kg of DOBA bleaching activator and 0.1 kg of [Mn] were added. Ⅳ The catalyst 2(μ-O)3(Me-TACN)2](PF6)2.H2O, 0.075 kg of citric acid, 0.025 kg of ascorbic acid, and 0.2 kg of acrylic acid-maleic anhydride copolymer sodium salt were added to a 10L screw dry mixer and mixed for 20 minutes until fully homogeneous. The homogeneous mixture was then transferred to a kneader, and 0.5 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 10%. The mixture was kneaded for 15 minutes until homogeneous. The homogeneous mixture was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the fluidized bed temperature controlled at 55-60℃. The fluidized bed-dried granules were sieved, and approximately 3.35 kg of composite bleaching activator and bleaching catalyst particles with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 67%.

[0041] Case 4

[0042] A compound bleaching activator consisting of 2.3 kg TAED, 1.2 kg NOBS, 1.1 kg DOBA, and 0.1 kg [Mn] was added. ⅣThe catalyst 2(μ-O)3(Me-TACN)2](PF6)2.H2O, 0.075 kg of citric acid, 0.025 kg of ascorbic acid, and 0.2 kg of acrylic acid-maleic anhydride copolymer sodium salt were added to a 10L screw dry mixer and mixed for 20 minutes until fully homogeneous. The homogeneous mixture was then transferred to a kneader, and 0.5 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 10%. The mixture was kneaded for 15 minutes until homogeneous. The homogeneous mixture was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the bed temperature controlled at 55-60°C. The fluidized bed-dried granules were sieved, and approximately 3.12 kg of composite bleaching activator and bleaching catalyst particles with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 62.4%.

[0043] Case 5

[0044] 4.6 kg of TAED bleaching activator and 0.1 kg of [Mn] were added. Ⅲ Ⅳ [μ-O)2(μ-OAc)(Me4-DTE)]Cl2 catalyst, 0.075 kg of citric acid, 0.025 kg of ascorbic acid, and 0.2 kg of acrylic acid-maleic anhydride copolymer sodium salt were added to a 10L screw dry mixer and mixed for 20 minutes until fully mixed. The uniformly mixed material was then transferred to a kneader, and 0.5 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 10%. The kneading was continued for 15 minutes until uniform. The uniformly kneaded material was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the bed temperature controlled at 55-60°C. The fluidized bed-dried granules were sieved, and approximately 3.35 kg of composite bleaching activator and bleaching catalyst particles with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 67%.

[0045] Case 6

[0046] 4.625 kg of TAED bleaching activator and 0.1 kg of [Mn] were added. ⅣThe catalyst 2(μ-O)3(Me-TACN)2](PF6)2.H2O, 0.075 kg of citric acid, and 0.2 kg of sodium salt of acrylic acid-maleic anhydride copolymer were added to a 10 L screw dry mixer and mixed for 20 minutes until fully mixed. The uniformly mixed material was then transferred to a kneader, and 0.5 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 10%. The mixture was kneaded for 15 minutes until uniform. The uniformly kneaded material was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the fluidized bed temperature controlled at 55-60 °C. The fluidized bed-dried granules were sieved, and approximately 3.2 kg of composite granules of bleaching activator and bleaching catalyst with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 64%.

[0047] Case 7

[0048] 4.605 kg of TAED bleaching activator and 0.1 kg of [Mn] were added. Ⅳ The catalyst 2(μ-O)3(Me-TACN)2](PF6)2.H2O, 0.025 kg of ascorbic acid, and 0.2 kg of acrylic acid-maleic anhydride copolymer sodium salt were added to a 10 L screw dry mixer and mixed for 20 minutes until fully mixed. The uniformly mixed material was then transferred to a kneader, and 0.5 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 10%. The kneading was continued for 15 minutes until uniform. The uniformly kneaded material was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the fluidized bed temperature controlled at 55-60 °C. The fluidized bed-dried granules were sieved, and approximately 3.3 kg of composite granules of bleaching activator and bleaching catalyst with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 66%.

[0049] Case 8

[0050] 4.7 kg of TAED bleaching activator and 0.1 kg of [Mn] were added. ⅣThe catalyst 2(μ-O)3(Me-TACN)2](PF6)2.H2O and 0.2 kg of acrylic acid-maleic anhydride copolymer sodium salt were added to a 10L screw dry mixer and mixed for 20 minutes until fully mixed. The uniformly mixed material was then transferred to a kneader, and 0.5 kg of distilled water was added through a nozzle during the kneading process while controlling the liquid-to-solid ratio at 10%. The kneading was continued for 15 minutes until uniform. The uniformly kneaded material was then transferred to a disc extruder for granulation. The resulting wet granules were then dried in a laboratory fluidized bed, with the fluidized bed temperature controlled at 55-60℃. The fluidized bed-dried granules were sieved, and approximately 3.3 kg of composite granules of bleaching activator and bleaching catalyst with a target size of 0.3 mm to 1.2 mm were finally obtained, with a single-pass yield of approximately 66%.

[0051] Table 1 shows the particle components and their content ratios in the above comparative cases 1-3 and cases 1-8.

[0052] Table 1. Composition of bleaching activator-bleaching catalyst particles I. Physical stability test of bleaching activator and bleaching catalyst particles Five grams each of the series of bleaching activators and bleaching catalyst particles prepared in the implementation case were weighed and placed in labeled small sample bottles. The sample bottles containing the samples were left open and placed in a constant temperature and humidity chamber at 40°C and 75% relative humidity. After 4 weeks, the samples were removed and the flowability and color changes of the particles were observed. The results of the physical stability experiment are shown in Table 2.

[0053] Table 2 Physical stability test of bleaching activator and bleaching catalyst particles Particle preparation method Particle Flow Particle color change Comparison Case 1 The particles are severely clumped together and lack fluidity. The surface of the particles is brown Comparison Case 2 The particles are intact and have good flowability. Brown spots appear on the surface of the particles Comparison Case 3 The particles are severely clumped together and lack fluidity. The surface of the particles is dark brown. Case 1 Particles are intact and have good flowability Particle color stable Case 2 The particles are intact and have good flowability. Particle color temperature Case 3 The particles are intact and have good flowability. Particle color stable Case 4 The particles are intact and have good flowability. Particle color stable Case 5 The particles are intact and have good flowability. Particle color stable Case 6 The particles are intact and have good flowability. Particle color stable Case 7 The particles are intact and have good flowability. Particle color stable Case 8 Particles are intact and have good flowability Brown spots appear on the surface of the particles II. Chemical stability test of bleaching activator and bleaching catalyst particles in dishwashing detergent base powder To evaluate the chemical stability of the prepared series of bleaching activators and bleaching catalyst particles, the bleaching activators and bleaching catalyst particles were further compounded with IEC-A dishwashing detergent base powder. The specific implementation method was as follows: 5 wt% of the prepared bleaching activators and bleaching catalyst particles were added to IEC-A dishwashing detergent base powder and mixed thoroughly. Then, 10 g of the thoroughly mixed material was placed in an open sample bottle and kept in a constant temperature and humidity environment of 40℃ and RH-75% for 4 weeks to conduct a compound stability experiment. The stability was determined by observing the surface color change of the bleaching activators and bleaching catalyst particles. The results of the compound stability are shown in Table 3.

[0054] Table 3 Stability test of bleaching activator and bleaching catalyst particles-chemical compound Particle preparation method Particle color change Comparison Case 1 The particles are dark brown. Comparison Case 2 The particles are dark brown. Comparison Case 3 The particles are dark brown. Case 1 Particle color stable Case 2 Particle color stable Case 3 Particle color stable Case 4 Particle color stable Case 5 Particle color stable Case 6 The particles are dark brown. Case 7 The particles are dark brown. Case 8 The particles are dark brown. By comparing the experimental data on the physical stability and compound chemical stability of the bleaching activator and bleaching catalyst particles in Tables 2 and 3, it can be found that the dry-wet combined granulation process proposed in this invention, as well as the optimization of the granulation binder and additives to control the atmosphere of the composite particles, not only solves the stability problem of the composite particles of bleaching activator and bleaching catalyst in detergent powder, but also improves the particle yield and particle strength during the granulation process, and avoids powder dust and safety issues during the granulation process.

[0055] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the concept of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A composite particle of highly efficient and stable bleaching catalyst and bleaching activator for use in dishwashing detergent, characterized in that: It includes bleaching catalysts, bleaching activators, binders, antioxidants, pH buffers, and other auxiliary components.

2. The composite particles of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 1, characterized in that: The bleaching catalyst content is 0-10 wt%, the bleaching activator content is 90-96 wt%, the binder content is 0-10 wt%, the antioxidant content is 0-5 wt%, the pH buffer content is 0-5 wt%, and the other components content is 0-2 wt%.

3. The highly efficient and stable bleaching catalyst and bleaching activator composite particles for dishwashing detergent according to claim 1 or 2, characterized in that: The bleaching catalyst is composed of a metal-organic coordination compound consisting of at least one polydentate macrocyclic organic molecule selected from Fe, Cu, Co, and Mn as the central atom and N, NR, or O atoms with lone pairs of electrons as ligands.

4. The highly efficient and stable bleaching catalyst and bleaching activator composite particles for dishwashing detergent according to claim 1 or 2, characterized in that: The bleaching activator is composed of one or more selected from polyalkylene diamines, acylated glucourea, acyloxysulfonates, acyloxycarboxylic acids, carboxylic anhydrides, acylated polyols, and acylated sugar derivatives.

5. A composite particle of highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 1 or 2, characterized in that: The adhesive is composed of one or more of the following: fatty acids, acrylic polymers or copolymers, povidones or copovidones, and water-soluble synthetic polymeric adhesives that do not contain hydroxyl groups.

6. The highly efficient and stable bleaching catalyst and bleaching activator composite particles for dishwashing detergent according to claim 1 or 2, characterized in that: The antioxidant includes at least one inorganic salt selected from sulfites, thiosulfates, isoascorbates, ascorbic acid salts, nitrites, or organic acids such as methionine, cysteine, propyl gallate, tert-butylhydroquinone, tocopherol, thiodipropionic acid, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tannic acid.

7. A composite particle of highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 1 or 2, characterized in that: The pH buffer comprises at least one system selected from phosphoric acid and its phosphates, polyacrylic acid or polyacrylic acid derivatives and their partially neutralized salts, and small molecule organic acids and their salts (citric acid and its disodium citrate).

8. A composite particle of highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 1 or 2, characterized in that: The other additives include one or more inert fillers, pigments, or functional indicator additives, wherein the inert filler is sodium sulfate, sodium chloride, or other inorganic salts.

9. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent as described in claim 1, characterized in that... The process includes dry mixing, wet mixing, granulation, drying, and sieving. Dry mixing step: The bleaching activator, bleaching catalyst, binder, antioxidant, pH adjuster and other additives are put into the dry mixing mixer in a predetermined proportion and the components are mixed evenly. Wet mixing step: After the material is dry-mixed evenly, it is transferred to a wet mixer, and a certain amount of water or an aqueous solution containing some functional additives is added according to a certain water-to-solid ratio to further wet mix, so as to promote the material to be mixed evenly and produce some viscosity. Granulation step: The materials that have been wet-mixed evenly are granulated to obtain bleaching activator and bleaching catalyst particles of a certain size through a granulation machine; Drying step: The wet granules of bleaching activator and bleaching catalyst obtained by the granulator are further dried by the dryer to reduce and control the moisture content of the composite granules of bleaching activator and bleaching catalyst. Sieving step: After drying, the bleaching activator and bleaching catalyst particles are further sieved to prepare composite particles of bleaching activator and bleaching catalyst within the target size range, and then packaged.

10. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 9, characterized in that: The dry mixing machine is selected from at least one of the following: horizontal ribbon mixer, plow mixer, zero-gravity twin-shaft paddle mixer, ribbon conical mixer, double-helix conical mixer, or triple-helix conical mixer.

11. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 9, characterized in that: The wet mixer for mixing dry materials with water is selected from one of the following: kneader, plow-type wet mixer, horizontal ribbon wet mixer, or planetary wet mixer.

12. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 9, characterized in that: The granulator is selected from at least one of the following: a swing granulator, a rotary extrusion granulator, a twin-screw extrusion granulator, or a high-speed mixing granulator.

13. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 9, characterized in that: The particle drying method shall be selected from at least one of the following: oven drying, belt drying, moving bed drying, or fluidized bed drying.

14. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 10, characterized in that: The dry mixing time is 10-60 minutes.

15. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 11, characterized in that: The wet mixing liquid-to-solid ratio is 5-20 wt%, and the wet mixing time is 5-30 minutes.

16. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 12, characterized in that: The granulation particle size is controlled to be 0.25~2.0mm.

17. The method for preparing a composite particle of a highly efficient and stable bleaching catalyst and bleaching activator for dishwashing detergent according to claim 13, characterized in that: The drying temperature is controlled at 50~100℃, and the particle diameter of the product after sieving is 0.25~1.6mm.

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