Building ceramic slurry dispersion-enhanced admixture, preparation method and application thereof

Abstract

The application belongs to the technical field of ceramic production aids, and particularly relates to a building ceramic slurry dispersion-enhanced additive, a preparation method and application thereof. The application discloses a ceramic slurry dispersion-enhanced additive. Raw materials of the ceramic additive include modified silicate material, carboxylic acid grafted ester amine copolymer, modified polymethyl methacrylate and charge shielding agent. The ceramic slurry dispersion-enhanced additive of the application is applied to the ball milling dispersion and sintering process of ceramic production, which can further improve the dispersion performance of the ceramic slurry, reduce the water demand of the ball milling process and the energy consumption of the subsequent sintering process, improve the green strength, facilitate the subsequent processing stability, reduce the waste rate and improve the ceramic production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of ceramic production additives technology, specifically relating to a building ceramic slurry dispersing-reinforcing admixture, its preparation method, and its application. Background Technology

[0002] Ceramics are inorganic non-metallic materials prepared by high-temperature sintering. They are mainly composed of minerals such as clay, feldspar, and quartz, and possess excellent properties such as high hardness, high-temperature resistance, and corrosion resistance, making them widely used in structural and functional materials. With the development of materials science, modern ceramics are divided into traditional ceramics and new ceramics. Traditional ceramics include daily-use ceramics and building ceramics; new ceramics encompass electronic ceramics, bioceramics, and structural ceramics, playing important roles in electronic components, medical devices, and high-temperature and high-strength environments, respectively. The ceramic production process typically includes raw material processing, molding, drying, sintering, and surface treatment. The dispersibility and particle size of the raw materials directly affect product quality. To improve the flowability and processing performance of the slurry, admixtures are often added during production to enhance the mechanical properties of the ceramics, increase sintering density, and reduce defects. Dispersants play a crucial role in reducing the interaction forces between particles, ensuring uniform distribution of solid particles, improving the flowability and stability of the slurry, ensuring smooth molding and sintering processes, and effectively preventing the formation of cracks and defects. Furthermore, reducing the moisture content of the slurry entering the drying tower can also reduce the energy consumption for evaporating moisture during the drying process, which is of great significance for improving production efficiency and energy conservation and emission reduction. Reinforcing agents are mainly used to improve the mechanical strength and impact resistance of ceramics, increase the density and durability of the material, and make it perform better in high-stress or harsh environments.

[0003] Currently, commonly used dispersants for building ceramics include inorganic electrolytes (such as sodium phosphate, sodium silicate, sodium carbonate, sodium metasilicate, etc.), small organic molecules (such as sodium citrate, sodium humate, etc.), and organic polymers (such as sodium polyacrylate, polyacrylamide, styrene-maleic anhydride copolymer, etc.). These dispersants exert their dispersion mechanism through electrostatic repulsion and / or steric hindrance. Common reinforcing agents for building ceramic bodies include sodium lignosulfonate, calcium lignosulfonate, sodium methyl cellulose, polyvinyl alcohol and propylene polymers, sodium polyacrylate, and sodium alginate. The use of reinforcing agents can improve the green strength of the body, but it usually also increases the viscosity of the slurry, adversely affecting the flowability of the ceramic slurry. Therefore, how to improve the green strength while maintaining good slurry flowability is a major challenge in the application of ceramic admixtures.

[0004] Traditional ceramic admixtures have limitations in terms of effectiveness, dosage, and cost, making it difficult to simultaneously meet the requirements for dispersibility and strengthening properties in ceramic production. Therefore, the research and development of multifunctional dispersants has gradually become a hot topic. For example, Chinese invention patent CN112573929A discloses a composite ceramic water-reducing agent, whose main components include sodium metasilicate, sodium polyphosphate, methylcellulose, sodium citrate, sodium perborate, magnesium carbonate, polyolamine, fatty alcohol polyoxyethylene ether, and waste sand. This water-reducing agent can not only reduce the water content of the slurry, shorten the ball milling time, and reduce grinding power consumption, but also improve the strength of the dried ceramic blank, possessing grinding aid, strength enhancement, and water-reducing functions. This water-reducing agent is suitable for clays with a high content of lean materials, can improve the product forming qualification rate, reduce production costs, and has energy-saving and emission-reduction effects. Chinese invention patent CN104291830A discloses a composite ceramic dispersant, which is mainly composed of sodium humate, polyacrylamide, sodium polyacrylate, and potassium persulfate. The dispersant is prepared using microwave radiation technology, significantly improving the reaction speed and efficiency. This dispersant effectively improves the fluidity of ceramic slurry, reduces the water content of the slurry, thereby reducing drying energy consumption and improving the strength of ceramic products. This dispersant has good versatility, is suitable for various clay mineral raw materials, and still achieves good dispersion effects even with small addition amounts. Chinese invention patent CN105968270A discloses a composite ceramic water-reducing agent, which mainly comprises tannin, diallyl polyethylene glycol ether, glucose acrylate, unsaturated carboxylic acids and their salts, an initiator, and an inorganic dispersant. The above components are mixed and subjected to a polymerization reaction. By controlling the temperature and reaction time, a ceramic water-reducing agent with good fluidity and viscosity control effects is obtained. This water-reducing agent can reduce the moisture content in ceramic slurry, improve the fluidity of the slurry and the flexural strength of the green body, thereby achieving the effects of energy saving, consumption reduction and improved performance of ceramic products.

[0005] In summary, current composite ceramic water-reducing agents / dispersants primarily enhance the dispersion of synthesized or combined products in ceramic slurries by incorporating key inorganic or organic functional groups, thereby reducing the water requirement of ceramic clay particles during ball milling. However, the market currently offers a limited number of ceramic admixtures that simultaneously possess excellent dispersing properties and significantly enhance green body strength. There remains a significant market demand for composite ceramic admixtures, characterized by strong versatility, low dosage, and high effectiveness. Therefore, further development of multifunctional ceramic admixtures that integrate various functions, require low dosage, and are environmentally friendly is necessary. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this invention proposes a ceramic slurry dispersing-reinforcing admixture and its preparation method, aiming to solve the compatibility problem between the dispersibility and reinforcing properties of ceramic slurries. This admixture can effectively improve the dispersibility and flowability of ceramic slurries, and enhance the mechanical strength and durability of the final product, providing a more efficient and stable solution for ceramic production, and has practical application significance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This invention provides a ceramic slurry dispersion-reinforcing admixture, wherein, by mass parts, the raw materials of the admixture include 15-25 parts of modified silicate material, 3-8 parts of carboxylic acid grafted ester amine copolymer, 1-5 parts of modified polymethacrylate, and 6-12 parts of charge shielding agent.

[0009] The modified silicate material is prepared by adding sodium hydroxide aqueous solution to water glass, adjusting its modulus to 2.0, then adding aluminum chloride solution and ore powder, and controlling the silicon-aluminum ratio in the solution to be 200:2-4. The mixture is then calcined at 625-700℃ for 5-25 minutes, and finally cooled and ground to obtain the modified silicate material.

[0010] The carboxylic acid grafted amine copolymer is an alkanolamine-carboxylic acid type polymer. Its preparation method is as follows: 59-66 parts of N-methyl mixed alkanolamine, 33-39 parts of maleic anhydride, 1-1.6 parts of concentrated sulfuric acid, 15-100 parts of butyl acetate, and 0.4-0.6 parts of hydroquinone are mixed and reacted at 110-120℃ for 4-8 hours. Unreacted raw materials are recovered by vacuum distillation. After separation and purification, an intermediate is obtained. The intermediate is then diluted with water to a mass concentration of 15%-30%. The temperature is raised to 80-90℃, and then 40%-50% of isopentenyl alcohol polyoxyethylene ether and 5%-10% of potassium persulfate are added. The reaction is carried out for 2-4 hours and cooled. The pH of the solution is adjusted to neutral to obtain the carboxylic acid grafted amine copolymer.

[0011] The modified polymethacrylate is prepared by mixing 92-105 parts of an acrylic acid solution with a mass concentration of 10% with 40-70 parts of sodium methacrylate sulfonate, purging with nitrogen for 15-30 minutes under continuous stirring, then adding 7.5-10 parts of potassium persulfate and 3.8-5.1 parts of sodium bisulfite redox initiator, and then heating to 60-80℃ to initiate the polymerization reaction for 1-3 hours. Then adding 0.2-0.8 parts of hydroxyethyl cellulose to the reaction solution and maintaining a constant temperature for 2-4 hours, and then separating and purifying after the reaction to obtain the modified polymethacrylate.

[0012] This invention utilizes specific dehydration and decomposition reactions of water glass under intermediate temperature conditions to prepare a novel layered silicate. This raw material possesses strong ion exchange capacity, enhancing the water-reducing effect of traditional phosphate dispersants, further improving the fluidity of ceramic slurries, and also exhibiting pH alkalinity adjustment and enhanced green body strength effects. Subsequently, a carboxylic acid-grafted amine copolymer was prepared via chemical synthesis. This polymer acts as a grinding aid during ceramic raw material mixing, reduces water content in the slurry, maintains slurry stability, and delays stratification during settling. The ceramic slurry admixture prepared by this formulation exhibits multifunctional effects, is applicable to a wide range of ceramic raw materials, provides excellent slurry dispersion, further reduces water demand, and contributes to energy conservation and emission reduction in the production process. It is a green and environmentally friendly high-performance admixture.

[0013] Preferably, the ore powder includes at least one of montmorillonite powder, vermiculite powder, hydrotalcite powder, and barite powder.

[0014] Preferably, the ore powder has a particle size of less than 0.1 mm and its mass fraction in the mixture is 10%-20%.

[0015] Preferably, the monomer molecular weight of the isopentenyl alcohol polyoxyethylene ether is 800-1600.

[0016] Preferably, isopentenyl alcohol polyoxyethylene ether with a mass concentration of 40%-50% and potassium persulfate with a mass concentration of 5%-10% are slowly added dropwise over 5 hours.

[0017] Preferably, the oxidation initiator is potassium persulfate, and the reduction initiator is sodium bisulfite.

[0018] Preferably, the charge shielding agent is at least one of sodium hexametaphosphate, sodium tripolyphosphate, sodium polyacrylate, sodium polycarboxylate, sodium citrate, sodium oxalate, and sodium humate.

[0019] The present invention also provides the application of the above-mentioned ceramic slurry dispersing-reinforcing admixture in the preparation of building ceramics.

[0020] The ceramic slurry additive involved in this invention not only satisfies the dispersibility requirements of the ceramic slurry but also optimizes the green body strength in the subsequent green body preparation process, ensuring the product's performance in energy saving, consumption reduction, and high-efficiency production. It can meet the ceramic industry's demand for efficient and low-energy-consumption production processes, while simultaneously promoting the improvement of ceramic product quality and production efficiency.

[0021] Preferably, the amount of the ceramic slurry dispersing-reinforcing admixture used in the preparation of building ceramics is 0.1-1.2 wt%.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention discloses a ceramic slurry dispersing-reinforcing admixture. The raw materials of this ceramic admixture include modified silicate material, carboxylic acid grafted amine copolymer, modified polymethacrylate, and a charge shielding agent. Applying this ceramic slurry dispersing-reinforcing admixture to the ball milling and sintering stages of ceramic production can further improve the dispersion performance of the ceramic slurry, reduce the water requirement in the ball milling process and the energy consumption in the subsequent sintering process, and also improve the green body strength, which is beneficial for subsequent processing stability, reduces the scrap rate, and improves ceramic production efficiency. Overall, this invention has the following advantages:

[0024] (1) The ceramic multifunctional admixture provided by the present invention has a small dosage, is easy to store, meets environmental protection requirements, and is suitable for large-scale production conditions. In terms of product function, the admixture integrates multiple functions such as grinding aid, dispersion and water reduction, alkaline pH buffer, stabilizing suspended colloid and enhancing the strength of the green body. It not only ensures the flow quality of slurry and the strength of green body pressing in the ceramic production process, but also helps to reduce the water demand in the material preparation process and the energy consumption of the subsequent spray drying process. It is green and environmentally friendly and is a multifunctional admixture.

[0025] (2) In the ceramic multifunctional admixture raw material provided by this invention, the use of modified silicate material significantly reduces the dosage of phosphate dispersants commonly used in ceramic processes, mitigating the environmental impact of traditional admixtures. Modified silicate material possesses certain grinding aid effects and high-temperature stability, ensuring continuous effectiveness during ball milling heating, which helps shorten the ball milling process of ceramic raw materials and optimize particle size distribution. In ceramic slurry, modified silicate material has pH buffering capacity and strong cation exchange capacity. On the one hand, it can stabilize the alkaline environment of the ceramic slurry, making the surface of ceramic particles as negatively charged as possible. On the other hand, the unique layered structure of modified silicate material contains negatively charged silicate groups that attract calcium, magnesium, and aluminum ions from the slurry into the interlayer through charge neutralization, further increasing the negative charge on the surface of ceramic particles and enhancing the dispersion effect. In the subsequent sintering process of the green body, this modified silicate material can also undergo chemical reactions with other ceramic raw materials, forming new phase structures that act as bridges or fillers within the material, thereby enhancing the overall mechanical strength of the ceramic material.

[0026] (3) The ceramic multifunctional admixture raw material provided by this invention uses modified polymethacrylate, which is a linear polycarboxylic acid dispersant. The main chain has strong anionic properties, which can attract and stabilize positively charged particles. The side chains have a large number of hydroxyl groups, which have good water solubility and adhesion. Based on its molecular characteristics, the carboxyl and sulfonate groups on the main chain can provide negative charges to the ceramic particles, enhance the electrostatic repulsion between particles, and prevent particle agglomeration. The grafted side chains further prevent particles from approaching and agglomerating by providing steric hindrance, maintain the good dispersion state of the particles, and have a certain stability to temperature and pH changes, which is conducive to the formation of a stable dispersion system of slurry under different conditions.

[0027] (4) The ceramic multifunctional admixture raw material provided by this invention uses a carboxylic acid grafted ester amine copolymer. This polymer has a carboxylic acid comb-shaped molecular structure, with polyoxyethylene chains, hydroxyl groups, amine groups, carboxyl groups, ester groups, and other functional groups distributed on the molecular side chains. This facilitates the contact between the active part of the molecular surface and the surface of ceramic particles, forming an adsorption film. Moreover, the molecular branches can form a three-dimensional cross with the branches on the surface of other particles, reducing direct contact between particles and playing an excellent role in grinding and dispersing, further optimizing the particle size distribution effect of the ceramic raw material after ball milling. In addition, the active sites on the molecule can undergo cross-linking reactions with metal cations to form a three-dimensional gel network structure, which captures and fixes suspended ceramic particles, preventing them from settling, maintaining the stability of suspended particles under static or low shear stress, and increasing the efficiency of preform preparation. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0030] In the following examples, all units (parts) refer to parts by mass.

[0031] Example 1

[0032] A ceramic slurry dispersion-reinforcing admixture, by mass parts, comprises: 18.7 parts modified silicate material, 4.7 parts carboxylic acid grafted amine copolymer, 3.5 parts modified polymethacrylate, and 8 parts charge shielding agent (sodium hexametaphosphate).

[0033] The preparation method is as follows: The above-mentioned raw materials are mixed according to the specified proportions. Specifically, the modified silicate material, carboxylic acid grafted amine copolymer, and modified polymethacrylate are prepared as follows:

[0034] The modified silicate material is prepared as follows: 100 parts of industrially produced water glass with a modulus of 2.4 and a solid content of 49% are taken, and 25.33 parts of a 15% (w / w) sodium hydroxide solution prepared with deionized water are added. Then, 5.87 parts of a 10% (w / w) aluminum chloride solution and 17 parts of montmorillonite powder (particle size less than 0.1 mm) are added to adjust the modulus of the water glass to 2.0 (silicon-to-aluminum ratio in the solution = 200:3). The water glass with the adjusted modulus is then placed in a rotary stirring furnace, and the heating rate is set to 30℃ / min. The temperature is raised to a holding temperature of 675℃ and held for 9 minutes. After the holding period, the crucible is removed using a heat-insulating tool, and the product is rapidly cooled to room temperature by cold air. After crushing and grinding, the modified silicate material is obtained.

[0035] The preparation method of the carboxylic acid grafted ester amine copolymer is as follows: In a four-necked flask equipped with a constant temperature oil bath, thermometer, stirrer and condenser, 50 parts of N-methyldiethanolamine, 41.2 parts of maleic anhydride, 1.3 parts of 98% concentrated sulfuric acid, 41.2 parts of butyl acetate and 0.5 parts of hydroquinone are added sequentially. The temperature is raised to 115°C and stirred continuously. After reacting for 6 hours, the butyl acetate and unreacted raw materials are recovered by vacuum distillation (vacuum degree 200-300 mmHg, 60-80°C), and purified (aqueous phase extraction method). An intermediate was obtained; then 8.4 parts of the intermediate were diluted with 45 parts of deionized water to a concentration of 15.7%, added to a reaction vessel, and the temperature was maintained at 85±1℃. Then, 15 parts of 5.5% ammonium persulfate initiator solution and 60.1 parts of 50% isopentenyl alcohol polyoxyethylene ether (monomer molecular weight of 1200) solution were slowly added dropwise over 5 hours. After maintaining the temperature for 3 hours, the product was cooled to below 40℃ and adjusted to neutral with 30% NaOH solution. Finally, a carboxylic acid grafted ester amine copolymer liquid with an orange-yellow or orange-red color was obtained.

[0036] The modified polymethacrylate is prepared as follows: In a four-necked flask equipped with a constant temperature oil bath, thermometer, stirrer and condenser, 73 parts of 10% mass concentration acrylic acid solution and 47 parts of sodium methacrylate sulfonate are added. Under continuous stirring, nitrogen gas is purged for about 20 minutes. Then, 6.1 parts of potassium persulfate and 3.04 parts of sodium bisulfite redox initiator are added sequentially. The mixture is heated to 70°C to initiate the polymerization reaction for 2 hours. Then, 0.3 parts of hydroxyethyl cellulose are slowly added to the reaction solution and the reaction is maintained at a constant temperature for 3 hours. After the reaction is complete, the modified polymethacrylate is obtained after separation and purification.

[0037] Example 2

[0038] A ceramic slurry dispersion-reinforcing admixture, by mass parts, comprises: 17.0 parts modified silicate material, 4.9 parts carboxylic acid grafted amine copolymer, 2.8 parts modified polymethacrylate, and 7 parts charge shielding agent (sodium hexametaphosphate).

[0039] The preparation method is as follows: The above-mentioned raw materials are mixed according to the specified proportions. Specifically, the modified silicate material, carboxylic acid grafted amine copolymer, and modified polymethacrylate are prepared as follows:

[0040] The modified silicate material is prepared as follows: 100 parts of industrially produced water glass with a modulus of 2.4 and a solid content of 49% are taken, and 25.33 parts of a 15% (w / w) sodium hydroxide solution prepared with deionized water are added. Then, 5.87 parts of a 10% (w / w) aluminum chloride solution and 17 parts of montmorillonite powder (particle size less than 0.1 mm) are added to adjust the modulus of the water glass to 2.0 (silicon-to-aluminum ratio in the solution = 200:3). The water glass with the adjusted modulus is then placed in a rotary stirring furnace, and the heating rate is set to 30℃ / min. The temperature is raised to a holding temperature of 675℃ and held for 9 minutes. After the holding period, the crucible is removed using a heat-insulating tool, and the product is rapidly cooled to room temperature by cold air. After crushing and grinding, the modified silicate material is obtained.

[0041] The preparation method of the carboxylic acid grafted ester amine copolymer is as follows: In a four-necked flask equipped with a constant temperature oil bath, thermometer, stirrer and condenser, 47 parts of N-methyldiethanolamine, 38.2 parts of maleic anhydride, 1.5 parts of 98% concentrated sulfuric acid, 38.2 parts of butyl acetate and 0.54 parts of hydroquinone are added sequentially. The temperature is raised to 115°C and stirred continuously. After reacting for 6 hours, the butyl acetate and unreacted raw materials are recovered by vacuum distillation (vacuum degree 200-300 mmHg, 60-80°C), and purified (aqueous phase extraction method). An intermediate was obtained; then 15.9 parts of the intermediate were diluted with 67.6 parts of deionized water to a concentration of 19%, added to a reaction vessel, and the temperature was maintained at 85±1℃. Then, 24.4 parts of 6.6% ammonium persulfate initiator solution and 87.5 parts of 48.3% isopentenyl alcohol polyoxyethylene ether (monomer molecular weight of 1200) solution were slowly added dropwise over 5 hours. After maintaining the temperature for 3 hours, the product was cooled to below 40℃ and adjusted to neutral with 30% NaOH solution. Finally, an orange-yellow or orange-red alkanolamine-carboxylic acid polymer liquid was obtained.

[0042] The modified polymethacrylate is prepared as follows: In a four-necked flask equipped with a constant temperature oil bath, thermometer, stirrer and condenser, 87 parts of 10% mass concentration acrylic acid solution and 47.9 parts of sodium methacrylate sulfonate are added. Under continuous stirring, nitrogen gas is purged for about 20 minutes. Then, 7.66 parts of potassium persulfate and 3.8 parts of sodium bisulfite redox initiator are added sequentially. The mixture is heated to 70°C to initiate the polymerization reaction for 2 hours. Then, 0.44 parts of hydroxyethyl cellulose are slowly added to the reaction solution and the reaction is maintained at a constant temperature for 3 hours. After the reaction is complete, the modified polymethacrylate is obtained after separation and purification.

[0043] Example 3

[0044] A ceramic slurry dispersion-reinforcing admixture, by mass parts, comprises: 20 parts modified silicate material, 5.5 parts carboxylic acid grafted ester amine copolymer, 3.0 parts modified polymethacrylate, and 10 parts charge shielding agent (sodium hexametaphosphate).

[0045] The preparation method is as follows: The above-mentioned raw materials are mixed according to the specified proportions. Specifically, the modified silicate material, carboxylic acid grafted amine copolymer, and modified polymethacrylate are prepared as follows:

[0046] The modified silicate material is prepared as follows: 100 parts of industrially produced water glass with a modulus of 2.4 and a solid content of 49% are taken, and 25.33 parts of a 15% (w / w) sodium hydroxide solution prepared with deionized water are added. Then, 5.87 parts of a 10% (w / w) aluminum chloride solution and 17 parts of montmorillonite powder (particle size less than 0.1 mm) are added to adjust the modulus of the water glass to 2.0 (silicon-to-aluminum ratio in the solution = 200:3). The water glass with the adjusted modulus is then placed in a rotary stirring furnace, and the heating rate is set to 30℃ / min. The temperature is raised to a holding temperature of 675℃ and held for 9 minutes. After the holding period, the crucible is removed using a heat-insulating tool, and the product is rapidly cooled to room temperature by cold air. After crushing and grinding, the modified silicate material is obtained.

[0047] The preparation method of the carboxylic acid grafted ester amine copolymer is as follows: In a four-necked flask equipped with a constant temperature oil bath, thermometer, stirrer and condenser, 51 parts of N-methyldiethanolamine, 41.7 parts of maleic anhydride, 1.5 parts of 98% concentrated sulfuric acid, 41.7 parts of butyl acetate and 0.5 parts of hydroquinone are added sequentially. The temperature is raised to 115°C and stirred continuously. After reacting for 6 hours, the butyl acetate and unreacted raw materials are recovered by vacuum distillation (vacuum degree 200-300 mmHg, 60-80°C). The product is then purified (aqueous phase extraction method) to obtain... Intermediate; then take 9.1 parts of the intermediate and dilute it with 37.1 parts of deionized water to a concentration of 19.6%, add it to the reaction vessel, keep the temperature at 85±1℃, and then slowly add 12.0 parts of 6.5% ammonium persulfate initiator solution and 42.8 parts of 47.7% isopentenyl alcohol polyoxyethylene ether (monomer molecular weight of 1200) solution over 5 hours. After maintaining for 3 hours, cool the product to below 40℃ and adjust it to neutral with 30% NaOH solution to finally obtain an orange-yellow or orange-red alkanolamine-carboxylic acid polymer liquid.

[0048] The modified polymethyl methacrylate is prepared as follows: In a four-necked flask equipped with a constant temperature oil bath, thermometer, stirrer and condenser, 85 parts of 10% mass concentration acrylic acid solution and 51 parts of sodium methacrylate sulfonate are added. Under continuous stirring, nitrogen gas is purged for about 20 minutes. Then, 7.65 parts of potassium persulfate and 3.8 parts of sodium bisulfite redox initiator are added sequentially. The mixture is heated to 70°C to initiate the polymerization reaction for 2 hours. Then, 0.34 parts of hydroxyethyl cellulose are slowly added to the reaction solution and the reaction is maintained at a constant temperature for 3 hours. After the reaction is complete, the modified polymethyl methacrylate is obtained after separation and purification.

[0049] Example 4

[0050] A ceramic slurry dispersion-reinforcing additive, by mass parts, comprises: 23 parts modified silicate material, 5.1 parts carboxylic acid grafted amine copolymer, 3.2 parts modified polymethacrylate, and 8.5 parts charge shielding agent (sodium hexametaphosphate).

[0051] The preparation method is as follows: The above-mentioned raw materials are mixed according to the specified proportions. Specifically, the modified silicate material, carboxylic acid grafted amine copolymer, and modified polymethacrylate are prepared as follows:

[0052] The modified silicate material is prepared as follows: 100 parts of industrially produced water glass with a modulus of 2.4 and a solid content of 49% are taken, and 25.33 parts of a 15% (w / w) sodium hydroxide solution prepared with deionized water are added. Then, 5.87 parts of a 10% (w / w) aluminum chloride solution and 17 parts of montmorillonite powder (particle size less than 0.1 mm) are added to adjust the modulus of the water glass to 2.0 (silicon-to-aluminum ratio in the solution = 200:3). The water glass with the adjusted modulus is then placed in a rotary stirring furnace, and the heating rate is set to 30℃ / min. The temperature is raised to a holding temperature of 675℃ and held for 9 minutes. After the holding period, the crucible is removed using a heat-insulating tool, and the product is rapidly cooled to room temperature by cold air. After crushing and grinding, the modified silicate material is obtained.

[0053] The preparation method of the carboxylic acid grafted ester amine copolymer is as follows: In a four-necked flask equipped with a constant temperature oil bath, thermometer, stirrer and condenser, 58 parts of N-methyldiethanolamine, 48.2 parts of maleic anhydride, 2.1 parts of 98% concentrated sulfuric acid, 47.6 parts of butyl acetate and 0.5 parts of hydroquinone are added sequentially. The temperature is raised to 115°C and stirred continuously. After reacting for 6 hours, the butyl acetate and unreacted raw materials are recovered by vacuum distillation (vacuum degree 200-300 mmHg, 60-80°C). The copolymer is purified (aqueous phase extraction method) to obtain the intermediate... Intermediate; then take 14.3 parts of the intermediate and dilute it with 61.3 parts of deionized water to a concentration of 22.3%, add it to the reaction vessel, keep the temperature at 85±1℃, and then slowly add 19.9 parts of 6.9% ammonium persulfate initiator solution and 68.4 parts of 45.7% isopentenyl alcohol polyoxyethylene ether (monomer molecular weight of 1200) solution over 5 hours. After maintaining for 3 hours, cool the product to below 40℃ and adjust it to neutral with 30% NaOH solution, finally obtaining an orange-yellow or orange-red alkanolamine-carboxylic acid polymer liquid.

[0054] The modified polymethacrylate is prepared as follows: In a four-necked flask equipped with a constant temperature oil bath, thermometer, stirrer and condenser, 76 parts of 10% mass concentration acrylic acid solution and 43.3 parts of sodium methacrylate sulfonate are added. Under continuous stirring, nitrogen gas is purged for about 20 minutes. Then, 7.6 parts of potassium persulfate and 3.8 parts of sodium bisulfite redox initiator are added sequentially. The mixture is heated to 70°C to initiate the polymerization reaction for 2 hours. Then, 0.25 parts of hydroxyethyl cellulose are slowly added to the reaction solution and the reaction is maintained at a constant temperature for 3 hours. After the reaction is complete, the modified polymethacrylate is obtained after separation and purification.

[0055] Experimental Example: Performance Testing

[0056] The main components of the ceramic formulation used in this test were: kaolin (22%), clay (15%), bauxite (36%), stone (5%), and white sand (22%). The experimental groups (referred to as Examples 1-4) included the ceramic slurry dispersing-reinforcing additives from Examples 1-4, while the control group included no ceramic additives (Reference 1) and a group containing commercially available ceramic additives (Reference 2, whose main components included 1.5%–2% triethanolamine diluent, 25%–30% sodium polyacrylate polymer, sodium tripolyphosphate, and water glass in a 5:3:1.5:0.5 mass ratio). The following tests were then conducted:

[0057] (1) Flowability of ceramic slurry

[0058] Flowability refers to the ability of a slurry to flow under certain conditions, and is usually related to its viscosity. A Ford-4 viscometer is used to measure the flowability of various ceramic slurries to evaluate their rheological properties. The Ford-4 viscometer indirectly reflects the viscosity of the slurry by measuring the time required for a specific volume to flow out. Viscosity is a key indicator of slurry flowability; higher viscosity indicates poorer flowability, while lower viscosity indicates better flowability. Measuring flowability can also monitor whether phenomena such as stratification, sedimentation, or agglomeration occur during storage or transportation of the slurry.

[0059] At the standard specified temperature (25℃), weigh the ceramic formula materials, control the moisture content to 28%, and add 0.4% of additives. Then mix them in a ball mill jar, set the speed to 400 r / min, and ball mill for 15 minutes to obtain a ceramic slurry. After ball milling stops, quickly pour out the slurry, let it stand for 30 seconds, and then fill the Ford-4 viscometer with the slurry until overflowing, ensuring the liquid surface is flat and free of air bubbles. Use a scraper to scrape off the excess sample from the rim of the cup, making the liquid surface level with the rim. Open the outlet of the Ford-4 viscometer and start the stopwatch simultaneously to observe the liquid flow. Start timing from the stopwatch until the liquid flow is interrupted or continuously interrupted. Each group is measured three times, and the average value t is taken. 0.5 As an indicator of fluidity.

[0060] Thickness reflects the changes in rheological properties of a slurry during settling due to interparticle interactions, flocculation, and agglomeration. Thickness is an important indicator for evaluating the stability and workability of a slurry under settling conditions. Thickness is calculated by measuring the outflow time of the slurry after ball milling and settling for different times (30 s and 30 min), thus quantitatively characterizing the thixotropic properties of the slurry. Using a ceramic slurry set for 30 min, the flowability t was measured over 30 s. 0.5 In the same manner, a 30-minute flowability test was performed to obtain t. 30 Then the thickness is calculated. Thickness = (t) 30 / t0.5 ).

[0061] According to the test results in Table 1, the 30-second flow rate of the ceramic slurry obtained by incorporating ceramic admixtures in Examples 1-4 was lower than that of Comparative Example 2. Comparative Example 1 is the result of ball milling the ceramic formulation without any admixtures. Without the admixture, the ceramic formulation soil after ball milling was severely agglomerated. All the water was adsorbed and encapsulated by the soil particles under the multiple influences of hydrophilic functional groups, capillary water bridges, and particle agglomeration and flocculation, thus lacking any fluidity. Furthermore, under the action of the optimized admixture formulation, the ceramic slurry exhibited a fluid state, and the admixtures in Examples 1-4 all showed significant advantages in dispersing the ceramic slurry. After 30 minutes, the focus was on evaluating the reflow properties of the slurry after settling. Excessive thickness would affect the uniformity and fluidity of the slurry, which is detrimental to subsequent production processes and product quality. Under the condition of meeting production requirements, the 30-minute flow rate of Examples 1-4 was lower than that of Comparative Example 2, and the thickness was also smaller. After standing for one day, the slurry did not separate into layers, indicating that the colloid has good stability.

[0062] Table 1 Results of fluidity quality test

[0063] Example 1 37 45 1.216 Example 2 36 43 1.194 Example 3 33 39 1.182 Example 4 34 41 1.206 Comparative Example 1 Unable to flow Unable to flow / Comparative Example 2 43 55 1.279

[0064] (2) Green body strength after ceramic slurry drying

[0065] The green body strength was tested using a dry pressing method: The prepared ceramic slurry was placed in a container and dried in a drying oven at 105℃ until the moisture content was 1-3%. The dried powder was then removed, granulated, and excess moisture was removed to achieve a suitable moisture content (usually between 5-10%). The granules were then sieved through a 20-mesh sieve. The sieved ceramic granules were placed in a well-ventilated bag and aged for 24 hours to allow the moisture and additives inside the granules to gradually and evenly distribute. The aged powder was placed in a dry pressing mold, and a dry pressing machine was used to apply high pressure, controlling the pressure at 30MPa and the holding time at 10s, to press the powder into a green body. After pressing, the green body was carefully removed from the mold and placed in a drying oven. The temperature and humidity were controlled to accelerate the drying process and ensure that the moisture in the green body was completely evaporated. The drying temperature was set at 115℃. Finally, the flexural strength of the green body was tested according to the standard (GB / T 3810.4-2006).

[0066] The test results in Table 2 show that the use of the dispersing-reinforcing admixtures in Examples 1-4 significantly improved the flexural strength of the ceramic slurry greens. Specifically, the admixtures of this invention, when added to the ceramic slurry, improve fluidity, regulate the moisture distribution in the slurry, making the drying process more uniform, reducing local stress concentration, and preventing cracking and deformation during drying. The modified silicate lamellar structure can fill the voids between ceramic particles, increasing the density and uniformity of the green body. This filling effect helps reduce porosity and defects in the green body, improves the strength of the green body, and synergistically forms a stable micro-network structure within the green body with the polymer, providing additional reinforcing effects. This helps optimize the ceramic production process, improve product quality, and increase production efficiency.

[0067] Table 2 Results of flexural strength test of green body

[0068]

[0069] In summary, applying the ceramic slurry dispersing-reinforcing admixture of the present invention to the ball milling dispersion and sintering stages of ceramic production can further improve the dispersion performance of ceramic slurry, reduce the water demand in the ball milling process and the energy consumption in the subsequent sintering process, and can also improve the green body strength, which is beneficial to the stability of subsequent processing, reduce the scrap rate, and improve the efficiency of ceramic production.

[0070] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A ceramic slurry dispersing-reinforcing admixture, characterized in that, The additives, by mass, consist of 15-25 parts of modified silicate material, 3-8 parts of carboxylic acid grafted ester amine copolymer, 1-5 parts of modified polymethacrylate, and 6-12 parts of charge shielding agent. The modified silicate material is prepared by adding sodium hydroxide aqueous solution to water glass, adjusting its modulus to 2.0, then adding aluminum chloride solution and ore powder, and controlling the silicon-aluminum ratio in the solution to be 200:2-4. The mixture is then calcined at 625-700℃ for 5-25 minutes, and finally cooled and ground to obtain the modified silicate material. The carboxylic acid grafted ester amine copolymer is an alkanolamine-carboxylic acid type polymer. Its preparation method is as follows: 59-66 parts of N-methyl mixed alkanolamine, 33-39 parts of maleic anhydride, 1-1.6 parts of concentrated sulfuric acid, 15-100 parts of butyl acetate and 0.4-0.6 parts of hydroquinone are mixed and reacted at 110-120℃ for 4-8 hours. Unreacted raw materials are recovered by vacuum distillation. After separation and purification, an intermediate is obtained. The intermediate is then diluted with water to a mass concentration of 15%-30%. The temperature is raised to 80-90℃ and then 40%-50% of isopentenyl alcohol polyoxyethylene ether and 5%-10% of ammonium persulfate are added. The reaction is carried out for 2-4 hours and cooled. The pH of the solution is adjusted to neutral to obtain the carboxylic acid grafted ester amine copolymer. The modified polymethacrylate is prepared by mixing 92-105 parts of 10% acrylic acid solution with 40-70 parts of sodium methacrylate sulfonate, purging with nitrogen for 15-30 minutes under continuous stirring, then adding 7.5-10 parts of potassium persulfate and 3.8-5.1 parts of sodium bisulfite, and then heating to 60-80℃ to initiate a polymerization reaction for 1-3 hours. Then, 0.2-0.8 parts of hydroxyethyl cellulose are added to the reaction solution and the reaction is maintained at a constant temperature for 2-4 hours. After the reaction, the modified polymethacrylate is obtained by separation and purification.

2. The ceramic slurry dispersion-reinforcing admixture according to claim 1, characterized in that, The ore powder includes at least one of montmorillonite powder, vermiculite powder, hydrotalcite powder, and barite powder.

3. The ceramic slurry dispersion-reinforcing admixture according to claim 1, characterized in that, The ore powder has a particle size of less than 0.1 mm and a mass fraction of 10%-20% in the mixture.

4. The ceramic slurry dispersion-reinforcing admixture according to claim 1, characterized in that, The monomer molecular weight of the isopentenyl alcohol polyoxyethylene ether is 800-1600.

5. The ceramic slurry dispersion-reinforcing admixture according to claim 1, characterized in that, Slowly add isopentenyl alcohol polyoxyethylene ether with a mass concentration of 40%-50% and potassium persulfate with a mass concentration of 5%-10% over 5 hours.

6. The ceramic slurry dispersion-reinforcing admixture according to claim 1, characterized in that, The charge shielding agent is at least one of sodium hexametaphosphate, sodium tripolyphosphate, sodium polyacrylate, sodium polycarboxylate, sodium citrate, sodium oxalate, and sodium humate.

7. The application of the ceramic slurry dispersing-reinforcing admixture according to any one of claims 1-6 in the preparation of building ceramics.

8. The application according to claim 7, characterized in that, The dosage of the ceramic slurry dispersion-reinforcing admixture in the preparation of building ceramics is 0.1-1.2 wt%.

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