A high-temperature-resistant ceramic ink, a preparation method and an application method thereof

Abstract

The application discloses a high-temperature-resistant ceramic ink, a preparation method and an application method thereof. The preparation method comprises the following steps: uniformly mixing wrapped color powder, phosphate ester wetting agent and a solvent to obtain a premix; grinding the premix at a rotating speed of 7-10 m / s of an online speed to obtain coarse grinding material with a D50 of 0.7-1.0 microns; uniformly mixing talcum powder with a D50 of 1-2 microns into the coarse grinding material, wherein the talcum powder accounts for 0.1-0.5% of the mass of the wrapped color powder; then grinding at a rotating speed of 11-13 m / s of the online speed until the D50 of the wrapped color powder is 0.3-0.5 microns to obtain a color paste; and mixing the color paste, a resin carrier, a dispersing agent and other additives to obtain the high-temperature-resistant ceramic ink. The application realizes the standard average particle size of the wrapped color powder, optimizes and improves the particle size distribution, and improves the printing fluency and the color saturation and other color development effects after sintering.

Description

Technical Field

[0001] This application relates to the field of heat-resistant inks, and in particular to a high-temperature resistant ceramic ink, its preparation method, and its application method. Background Technology

[0002] Ceramic inkjet printing technology is currently the mainstream production process in the ceramic decoration field, and its core consumable is ceramic ink. Ceramic ink is typically formulated by dispersing inorganic pigments, polymeric resin carriers, dispersants, and other functional additives in an organic solvent, forming a suspension dispersion system with specific rheological properties. In a typical glazed tile production process, the application of ceramic ink generally involves: using a digital inkjet printer to spray ink onto the surface of a ceramic body or a body already coated with a base glaze, forming a pre-set decorative pattern; subsequently, the ink layer is dried at a low temperature to remove the solvent; after the ink layer is surface dry, a layer of transparent glaze is applied as a protective layer; finally, the body is sent to a kiln for high-temperature firing. During firing, the organic resin components in the ink layer decompose and escape due to heat, and the glaze melts, spreads, and bonds with the ink layer to solidify, ultimately forming a glazed tile product with a decorative pattern.

[0003] Based on the aforementioned process characteristics, the pigments used in ceramic inks must possess excellent high-temperature stability to resist high-temperature oxidation during the firing stage and chemical erosion by the glaze melt, thereby ensuring the vibrancy and saturation of the pattern's color. To meet this requirement, the industry commonly uses encapsulated inorganic pigments as the color-producing component. The core of this type of pigment is a chromophore capable of producing a specific color, such as cadmium sulfide selenide or cadmium sulfide, while the outer layer is coated with a dense, high-temperature resistant shell material. Common shell materials include zirconium silicate, zirconium dioxide, and silicon dioxide. This shell layer effectively isolates the chromophore from direct contact with external oxygen and corrosive glaze melt during the high-temperature firing stage, thus ensuring the structural integrity and color rendering effect of the core chromophore.

[0004] The color quality of coated toner is closely related to its particle size distribution. Generally speaking, the more uniform the particles and the narrower the particle size distribution, the better their dispersion stability in the ink system, and the more guaranteed the uniformity and vibrancy of the color after firing. At the same time, to meet the stringent requirements of inkjet printing for smoothness and non-clogging, the average particle size of the toner cannot be too coarse; otherwise, it is prone to gravity sedimentation, clogging the printhead micropores and causing broken lines or missing colors in printing. Currently, the original average particle size of commercially available coated toners is usually in the range of 2 to 10 μm. Directly using them to formulate inkjet inks poses a significant risk of sedimentation and clogging. Therefore, they often need to be ground and refined before actual use.

[0005] In existing technologies, even when the average particle size of the pigment coating is reduced to the target range by adjusting grinding parameters, the particle size distribution of pigments obtained by conventional grinding processes remains relatively wide, with significant coarseness and fineness variations in particle size. Specifically, the grinding products often contain a considerable number of both coarse and ultrafine particles. The presence of coarse particles reduces the dispersion stability and printing smoothness of the ink, increasing the risk of sedimentation and clogging; while ultrafine particles often correspond to fragments of shell damage caused by excessive breakage during the grinding process, increasing the exposure of some chromophores and thus affecting the color stability during subsequent high-temperature firing. This wide particle size distribution means that during the subsequent high-temperature firing process, the ink coating simultaneously contains both effective chromophores protected by intact shells and ineffective chromophores whose shells have been damaged. The color behavior of these two types differs significantly, ultimately leading to quality problems such as color difference, uneven color development, or decreased overall color saturation in the fired pattern. Summary of the Invention

[0006] This application provides a high-temperature resistant ceramic ink, its preparation method, and its application method, aiming to optimize and improve the particle size distribution and enhance the color saturation and other color development effects after firing, while ensuring that the average particle size of the coated pigment meets the standard.

[0007] In a first aspect, this application provides a method for preparing a high-temperature resistant ceramic ink, comprising the following steps: The coating pigment, phosphate ester wetting agent, and solvent are mixed in a mass ratio of 100:0.3~1.0:100~150 to obtain a premix; the premix is ​​then ground at an online speed of 7~10m / s to obtain a coarse abrasive with a D50 of 0.7~1.0μm. Add talc powder with a D50 of 1-2 μm to the coarse abrasive and mix well. The amount of talc powder is 0.1-0.5% of the mass of the pigment powder it coats. Then grind it at an online speed of 11-13 m / s until the D50 of the pigment powder it coats is 0.3-0.5 μm to obtain a pigment paste. By mixing color paste, resin carrier, dispersant and other additives, a high-temperature resistant ceramic ink is obtained.

[0008] In some embodiments, the phosphate ester wetting agent is selected from one or more of alkyl phosphate esters, fatty alcohol polyoxyethylene ether phosphate esters, and alkylphenol polyoxyethylene ether phosphate esters.

[0009] In some embodiments, the encapsulated color powder is selected from one or more of zirconium silicate-encapsulated cadmium sulfide selenide, zirconium dioxide-encapsulated cadmium sulfide, zirconium silicate-encapsulated cadmium sulfide, and zirconium dioxide-encapsulated cadmium sulfide.

[0010] The encapsulated pigment in this application uses cadmium sulfide selenide, etc., as the core and zirconium silicate or zirconium dioxide, etc., as the outer shell. The shell surface is rich in silanol and zirconium hydroxyl groups, exhibiting high surface energy and chemical activity. In the early stages of grinding, mechanical force breaks down large particles, exposing a large number of high-energy fresh surfaces and microcracks. These newly formed surfaces have high surface energy and are prone to secondary agglomeration through interparticle adsorption, leading to an increase in the proportion of coarse particles. In the later stages of grinding, when some particles have reached the target particle size, they are subjected to high-intensity shearing and impact, producing ultrafine particles with excessively thin or even broken shells. The core chromophores of these ultrafine particles are easily oxidized and faded during subsequent high-temperature firing.

[0011] To address the aforementioned issues, this application employs a segmented grinding process, matching differentiated grinding intensities and grinding aids at different stages to achieve effective control and narrowing of particle size distribution. The first stage of grinding is conducted at a relatively low linear velocity of 7–10 m / s, while a phosphate ester wetting agent is added to the premix. This type of wetting agent has a small molecular weight and strong penetrability; its phosphate ester groups can quickly penetrate into the fresh, high-energy surface and microcracks of the particles, and coordinate and anchor with metal ions on the shell surface. This strong chemical adsorption reduces the free energy of the newly formed surface, inhibiting its re-adhesion through van der Waals forces; on the other hand, the steric hindrance effect provided by the adsorption layer effectively hinders direct contact and cold welding between particles, thereby significantly reducing the generation of coarse particles, reducing the risk of clogging, and ensuring smooth printing. Once the average particle size D50 reaches 0.7–1.0 μm, the process transitions to the second stage of grinding, with the linear velocity increased to 11–13 m / s, to ensure that the average particle size can be further reduced to the target range of 0.3–0.5 μm. In this stage, a small amount of talc powder is introduced. Its Mohs hardness is much lower than that of zirconium silicate. In the initial stage of high-speed grinding, the average particle size of the added talc powder is larger than that of the pigment particles after the first stage of grinding, and its hardness is lower than that of the material encapsulating the pigment. During the second stage of high-speed grinding, the talc powder particles preferentially break down, forming fine inorganic particles dispersed in the slurry. This reduces the probability of direct collisions between the pigment particles, minimizes further breakage of particles that have reached the target particle size, and reduces the risk of over-grinding and breakage of qualified particles due to continuous stress, effectively reducing the generation of ultrafine particles.

[0012] Through the aforementioned segmented grinding process and the synergistic effect of phosphate ester wetting agents and talc, the particle size distribution range of the pigments can be significantly narrowed while ensuring the average particle size meets the standard, ultimately guaranteeing the uniformity and saturation of the color in the fired pattern. It is worth noting that the amount of talc is controlled within 0.5% of the weight of the pigment coating. This ensures that the talc plays a compensatory buffering role without interfering with the overall grinding efficiency due to excessive addition, thus guaranteeing the successful achievement of the average particle size standard. Furthermore, this trace addition has virtually no impact on the color performance after high-temperature firing.

[0013] In some embodiments, the particle size of the encapsulated pigment is 2–5 μm.

[0014] In some embodiments, in the grinding process, the diameter of the grinding media is 0.3 to 1.0 mm, and the diameter of the grinding disc is 100 to 250 mm.

[0015] It is worth noting that the linear velocity described in the above grinding process is a parameter of the linear velocity of the grinding media, calculated based on the diameter and rotational speed of the grinding disc. In the parameter control of actual grinding equipment, the linear velocity usually needs to be converted into a settable rotational speed (rpm). The conversion relationship is: rotational speed (rpm) = (v×60) / (π×D), where v is the linear velocity (m / s), D is the diameter of the grinding disc (m), and π is taken as 3.14. Using linear velocity as a control parameter ensures that the grinding intensity is not affected by differences in equipment size, guaranteeing the process reproducibility of the same process across different specifications of grinding equipment.

[0016] In some embodiments, the other additives include one or more of leveling agents, defoamers, and stabilizers.

[0017] In some embodiments, the solvent is selected from one or more of diethylene glycol ethyl ether, diethylene glycol methyl ether, propylene glycol methyl ether, ethylene glycol ethyl ether acetate, and propylene glycol methyl ether acetate.

[0018] In some embodiments, the dispersant is selected from one or more of polyurethane dispersants, polyacrylate dispersants, and stearamides.

[0019] In some embodiments, the resin carrier is selected from one or more of polyacrylic acid resin, polyethylene glycol, and ethyl cellulose.

[0020] Preferably, the resin carrier is a hydroxy acrylic resin, which is prepared by free radical copolymerization of the following raw materials in parts by weight: 25-35 parts styrene, 10-20 parts hydroxy acrylate, 50-65 parts alkyl acrylate, 0.5-1.5 parts chain transfer agent, and 1-2 parts initiator.

[0021] In some embodiments, the high-temperature resistant ceramic ink comprises the following raw materials in parts by weight: 100 parts color paste, 2-5 parts hydroxyl acrylic resin, 1-3 parts blocked isocyanate crosslinking agent, 5-10 parts dispersant, and 0.3-2 parts defoamer; the unblocking temperature of the blocked isocyanate crosslinking agent is 120-160°C.

[0022] In some embodiments, the number-average molecular weight of the acrylic resin is 8000 to 15000.

[0023] In some embodiments, the hydroxyacrylate is selected from at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, and hydroxypropyl acrylate; In some embodiments, the alkyl acrylate is selected from at least one of ethyl acrylate, butyl acrylate, or isooctyl acrylate; preferably butyl acrylate.

[0024] Secondly, this application provides a high-temperature resistant ceramic ink, which is prepared by any of the preparation methods described in the first aspect.

[0025] Thirdly, this application provides a method for applying a high-temperature resistant ceramic ink, comprising the following steps: The prepared high-temperature resistant ceramic ink is used to print a preset pattern on the surface of a ceramic blank through inkjet printing. The printed blank is dried at 150-250°C to deblock the blocked isocyanate crosslinking agent and crosslink and cure it with hydroxyl acrylic resin. Then, a layer of transparent glaze is applied to the surface of the patterned body, and the body is then sent into the kiln. Under an oxidizing atmosphere, the temperature is uniformly raised to 1000-1100℃ at a heating rate of 5-15℃ / min, and then held for firing to obtain a patterned ceramic product.

[0026] The coated pigments obtained through the aforementioned segmented grinding process have a narrow particle size distribution, good sphericity, and highly uniform particle morphology. While this characteristic is beneficial for color uniformity, it also leads to new problems. Specifically, when uniform pigment particles accumulate in the ink layer, it is difficult for them to form an effective gradation and filling, resulting in a high porosity. Simultaneously, during the subsequent sintering process, the organic resin components in the ink layer undergo pyrolysis and gradually decompose and escape in the range of approximately 300–500℃, leaving behind a large number of voids. At this time, conventional ceramic glazes have not yet reached their softening and melting temperature. Therefore, during the long temperature rise period from resin pyrolysis to glaze melting and wetting, the ink layer particles lose both the bridging support of the organic binder and the filling and reinforcement of the glaze melt, resulting in low adhesion strength. Combined with the high porosity of the pigment particles, the ink layer is highly susceptible to cracking or powdering and flaking due to volume shrinkage and thermal stress concentration, leading to pattern defects and uneven color development.

[0027] To address the aforementioned issues, this application employs a specific ratio of hydroxyl acrylic resin combined with a blocked isocyanate crosslinking agent as an organic carrier. The carbonization of the resin during the firing heating stage forms a transient carbon skeleton support, effectively suppressing shrinkage and thermal stress concentration that could lead to cracking or powdering and flaking. It is worth noting that the monomer composition of this acrylic resin plays a crucial role. First, the introduction of a carbon-rich, rigid benzene ring structure through styrene monomers increases the residual carbon rate, providing the necessary carbon source for the formation of a trace carbon skeleton after pyrolysis. The amount used must be controlled within a suitable range; excessive amounts will result in the carbon skeleton failing to completely oxidize and escape after the glaze melts, remaining in the glaze layer and causing a dull color. Second, the alkyl acrylate segments impart good flexibility and film-forming properties to the resin, ensuring the smoothness of the ink during inkjet printing and the basic physical properties of the ink layer. The hydroxyl acrylate units introduce side-chain hydroxyl groups, enabling the resin to undergo an addition reaction with the deblocked isocyanate crosslinking agent during the ink layer drying stage at 150–250°C, forming a three-dimensional crosslinked network. This cross-linked network, on the one hand, imparts initial strength to the ink layer after drying, effectively solving the problem of powder shedding after drying; on the other hand, the formation of the cross-linked network causes the polymer chain segments to preferentially undergo solid-phase carbonization rather than depolymerization and gasification during subsequent pyrolysis, providing a structural basis for the formation of the carbon skeleton.

[0028] In summary, when the ink layer enters the sintering stage and the temperature rises to the resin's pyrolysis temperature range (approximately 350–500℃), the three-dimensional cross-linked network and styrene segments undergo aromatization and carbonization reactions, transforming in situ into a continuous trace carbon skeleton. This carbon skeleton is uniformly distributed in the gaps between the pigment particles. During the heating stage, before the glaze reaches its softening and melting temperature and cannot penetrate and fill the gaps, it provides physical support and stress buffering, maintaining the interparticle spacing and effectively inhibiting the volume shrinkage and cracking of the ink layer caused by the decomposition of organic matter. As the temperature further increases, the carbon skeleton oxidizes and escapes, and the glaze gradually softens and melts, filling the gaps between particles and completing the encapsulation and fixation of the pigment particles. Finally, when the temperature is raised to a firing temperature of 1000–1100℃, the glaze completely melts and densifies, resulting in a ceramic product with a complete pattern and rich color.

[0029] It is worth noting that the number average molecular weight of the resin is controlled within the range of 8,000 to 15,000, which can maintain a suitable solution viscosity in the alcohol ether solvent system, ensuring that the ink meets the requirements of inkjet printing for smoothness.

[0030] In summary, this application has the following beneficial effects: This application improves the color development of ceramic inks by synergistically controlling the particle size of the pigment coating, synthesizing the resin carrier, and implementing the firing process. In the pigment grinding stage, a segmented grinding process combined with phosphate ester wetting agents effectively inhibits particle self-healing and agglomeration in the early stages of grinding, reducing the generation of coarse particles, by utilizing the coordination and anchoring effect of phosphate ester groups on the metal ions on the pigment shell surface. In the later stages of grinding, the introduction of an inert buffer medium reduces the risk of over-grinding of qualified particles, significantly decreasing the proportion of ultrafine particles. The resulting pigment paste has the advantages of controllable average particle size and narrowed particle size distribution, providing a fundamental guarantee for inkjet smoothness and color uniformity. Furthermore, this application uses hydroxyl acrylic resin and a blocked isocyanate crosslinking agent to form a three-dimensional network structure through drying temperature crosslinking. During the resin pyrolysis process, it is converted into a trace carbon skeleton in situ. In the heating stage where the glaze has not yet reached the softening and melting temperature and cannot penetrate to fill the gaps between particles, it plays a role in physical support and stress buffering, effectively suppressing the ink layer shrinkage, cracking and powdering problems caused by the combined effects of resin decomposition and high porosity between pigment particles, and significantly improving the firing quality of the ceramic ink encapsulated with pigment. Detailed Implementation

[0031] Preparation Example 1 This preparation example provides a hydroxyl acrylic resin, prepared by the following method: 300g of propylene glycol methyl ether acetate was added to a reaction flask, and nitrogen gas was introduced to purge the air from the flask. The mixture was stirred and heated to 85°C under nitrogen protection. 300g of styrene, 150g of hydroxyethyl methacrylate, 520g of butyl acrylate, 12g of dodecyl mercaptan, and 9g of azobisisobutyronitrile were mixed thoroughly to prepare a monomer mixture. The mixture was added dropwise to the reaction flask over 2 hours while maintaining the temperature at 85°C with continuous stirring. After the addition was complete, the reaction was maintained at 85°C for 1 hour. Then, a solution of 9g of azobisisobutyronitrile dissolved in 50g of propylene glycol methyl ether acetate was added, and the reaction was continued for another 2 hours. Heating was stopped, and the mixture was cooled to below 40°C. Propylene glycol methyl ether acetate was added to dilute the solution to a solid content of 50%, yielding a hydroxyl acrylic resin solution. The number-average molecular weight of the obtained resin was determined to be 11300 by gel permeation chromatography.

[0032] Preparation Example 2 This preparation example provides a hydroxyl acrylic resin, prepared by the following method: Add 350g of diethylene glycol ethyl ether to a reaction flask, purge the air from the flask with nitrogen, and stir and heat to 82°C under nitrogen protection. Mix 260g of styrene, 120g of hydroxyethyl methacrylate, 585g of butyl acrylate, 15g of dodecyl mercaptan, and 10g of benzoyl peroxide to prepare a monomer mixture. Maintain the temperature at 82°C and stir continuously, then add this monomer mixture dropwise to the reaction flask at a uniform rate over 2.5 hours. After the addition is complete, maintain the reaction at 82°C for 1.5 hours, then add 10g of benzoyl peroxide dissolved in 50g of diethylene glycol ethyl ether, and continue the reaction for another 2 hours. Stop heating, cool to below 40°C, and dilute with diethylene glycol ethyl ether to a solid content of 45%, obtaining a solution of hydroxyacrylic resin. The number-average molecular weight of the obtained resin was determined to be 9500 by gel permeation chromatography.

[0033] Preparation Example 3 This preparation example provides a hydroxyl acrylic resin, prepared by the following method: 400g of propylene glycol methyl ether acetate was added to a reaction flask, and nitrogen gas was introduced to purge the air from the flask. The mixture was stirred and heated to 88°C under nitrogen protection. 340g of styrene, 140g of hydroxypropyl acrylate, 500g of butyl acrylate, 10g of dodecyl mercaptan, and 10g of azobisisobutyronitrile were mixed thoroughly to prepare a monomer mixture. This monomer mixture was added dropwise to the reaction flask over 2 hours while maintaining the temperature at 85°C and stirring continuously. After the addition was complete, the reaction was maintained at 88°C for 1 hour. Then, 8g of azobisisobutyronitrile dissolved in 40g of propylene glycol methyl ether acetate was added, and the reaction was continued for another 2.5 hours. Heating was stopped, and the mixture was cooled to room temperature. Propylene glycol methyl ether acetate was added to dilute the solution to a solid content of 50%, yielding a hydroxyl acrylic resin solution. The number-average molecular weight of the obtained resin was determined to be 14200 by gel permeation chromatography.

[0034] Preparation Example 4 This preparation example provides a hydroxy acrylic resin, which differs from Preparation Example 1 in that the amount of styrene used is 150g.

[0035] Preparation Example 5 This preparation example provides a hydroxyl acrylic resin, which differs from Preparation Example 1 in that the amount of styrene used is 450g.

[0036] Preparation Example 6 This preparation example provides a hydroxy acrylic resin, which differs from Preparation Example 1 in that an equal mass of butyl acrylate is used instead of styrene.

[0037] Preparation Example 7 This preparation example provides an acrylic resin, which differs from Preparation Example 1 in that an equal mass of butyl acrylate is used instead of hydroxyethyl acrylate.

[0038] Example 1 This embodiment provides a high-temperature resistant ceramic ink and its application method, wherein the preparation method of the high-temperature resistant ceramic ink is as follows: Take 100g of zirconium silicate-coated cadmium sulfide selenide red powder (D50 of 2.8μm), 0.6g of fatty alcohol polyoxyethylene ether phosphate wetting agent (Rhodafac® RS-610), and 120g of diethylene glycol ethyl ether, and put them into a mixing tank. Stir at 800rpm for 30 minutes to obtain a premix. Feed the premix into a horizontal sand mill, using yttrium-stabilized zirconium oxide beads with a diameter of 0.5-0.6mm as the grinding media. The grinding disc diameter is 150mm. Adjust the linear speed of the sand mill to 8.5m / s (corresponding to a rotation speed of approximately 1082rpm) and perform one cycle of grinding. Take samples for testing every 15 minutes until the color powder D50 is 0.8-0.9μm to obtain coarse abrasive. Add 0.3g of ultrafine talc powder with a D50 of 1.5μm (accounting for 0.3% of the mass of the coated color powder) to the coarse abrasive, and continue to perform secondary cyclic grinding in the sand mill at a linear speed of 12m / s (corresponding to a rotation speed of about 1528rpm) until the color powder D50 is 0.4~0.5μm, then discharge the material to obtain the color paste.

[0039] Take 100g of the above color paste, add 4g of the hydroxyl acrylic resin solution obtained in Preparation Example 1, 2g of blocked isocyanate crosslinking agent (Covestro Desmodur® BL 3575, unblocking temperature 160℃), 7g of dispersant (Lubrizol Solsperse 24000), and 1g of defoamer BYK-066N. Stir in a disperser at 1200rpm for 45 minutes, filter, and obtain high-temperature resistant ceramic ink.

[0040] The application method of high-temperature resistant ceramic ink is as follows: Using a 12-channel digital inkjet printer, the above-mentioned high-temperature resistant ceramic ink is printed onto the surface of a porcelain tile blank that has been coated with a base glaze, forming a preset pattern. The printed blank is then placed in an infrared drying oven and dried at 200℃ for 7 minutes to allow the solvent to evaporate and the blocked isocyanate crosslinking agent to unblock, allowing it to crosslink and cure with hydroxyl acrylic resin. After cooling, a layer of transparent top glaze is applied onto the pattern layer using a bell-shaped glazing applicator, with a glaze application rate of 300g / m². 2 The brick blanks are then fed into a roller kiln and heated to 1050°C at a uniform rate of 10°C / min in an air atmosphere. The temperature is then maintained for 60 minutes to fire the bricks, resulting in glazed tiles with decorative patterns.

[0041] Example 2 This embodiment provides a high-temperature resistant ceramic ink and its application method, wherein the preparation method of the high-temperature resistant ceramic ink is as follows: 100g of zirconium silicate-coated cadmium sulfide selenide red powder (D50 of 2.8μm), 0.6g of dodecyl phosphate, and 110g of propylene glycol methyl ether were added to a mixing tank and stirred at 800 rpm for 30 minutes to obtain a premix. The premix was then fed into a horizontal sand mill with yttrium-stabilized zirconium oxide beads of 0.4–0.5 mm in diameter as the grinding media. The grinding disc diameter was 150 mm, and the linear speed of the sand mill was adjusted to 7 m / s (corresponding to a rotation speed of approximately 891 rpm). One cycle of grinding was performed. Samples were taken every 15 minutes for testing until the color powder D50 reached 0.7–0.8 μm, at which point coarse abrasive was obtained. Add 0.15g of ultrafine talc powder with a D50 of 1.2μm (accounting for 0.15% of the mass of the coated color powder) to the coarse abrasive, and continue to perform secondary cyclic grinding in a sand mill at a linear speed of 11m / s (corresponding to a rotation speed of about 1400rpm) until the color powder D50 is 0.3~0.4μm, then discharge the material to obtain a color paste.

[0042] Take 100g of the above color paste, add 2.5g of the hydroxyl acrylic resin solution obtained in Preparation Example 2, 2g of blocked isocyanate crosslinking agent (Covestro Desmodur® BL 3575, unblocking temperature 160℃), 5.5g of dispersant (Lubrizol Solsperse 24000), and 0.5g of defoamer BYK-066N. Stir at 1200rpm for 45 minutes in a disperser, filter, and obtain high-temperature resistant ceramic ink. The application method of the high-temperature resistant ceramic ink is as follows: Use a 12-channel digital inkjet printer to print the above high-temperature resistant ceramic ink onto the surface of a porcelain tile blank that has been glazed to form a preset pattern. Send the printed blank into an infrared drying oven and dry at 180℃ for 8 minutes to allow the solvent to evaporate and the blocked isocyanate crosslinking agent to unblock and crosslink with the hydroxyl acrylic resin. After cooling, apply a layer of transparent glaze on the pattern layer using a bell jar glazing applicator, with a glaze application amount of 300g / m². 2 The brick blanks are then fed into a roller kiln and heated to 1020°C at a uniform rate of 6°C / min in an air atmosphere. The temperature is then maintained for 90 minutes to fire the bricks, resulting in glazed tiles with decorative patterns.

[0043] Example 3 This embodiment provides a high-temperature resistant ceramic ink and its application method, wherein the preparation method of the high-temperature resistant ceramic ink is as follows: 100g of zirconium silicate-coated cadmium sulfide selenide red powder (D50 4.5μm), 0.9g of octylphenol polyoxyethylene ether phosphate (Xinyuhong OP-10P), and 140g of propylene glycol methyl ether acetate were added to a mixing tank and stirred at 800rpm for 30 minutes to obtain a premix. The premix was then fed into a horizontal sand mill, using yttrium-stabilized zirconium oxide beads with a diameter of 0.5-0.6mm as the grinding media. The grinding disc diameter was 150mm, and the mill linear speed was adjusted to 9.5m / s (corresponding to a rotation speed of approximately 1209rpm) for one cycle of grinding. Samples were taken every 15 minutes for testing until the color powder D50 was approximately 0.9-1.0μm, yielding coarse abrasive. Add 0.45g of ultrafine talc powder with a D50 of 1.5μm (accounting for 0.45% of the mass of the coated color powder) to the coarse abrasive, and continue to perform secondary cyclic grinding in a sand mill at a linear speed of 13m / s (corresponding to a rotation speed of about 1655rpm) until the color powder D50 is 0.4~0.5μm and D90≤0.95μm, then discharge the material to obtain the color paste.

[0044] Take 100g of the above color paste, add 4.9g of the hydroxyl acrylic resin solution obtained in Preparation Example 3, 2.8g of blocked isocyanate crosslinking agent (Desmodur® BL 3575, Covestro, unblocking temperature 160°C), 7g of dispersant (Lubrizol Solsperse 24000), and 1.6g of defoamer BYK-066N. Stir in a disperser at 1400rpm for 40 minutes, filter, and obtain high-temperature resistant ceramic ink.

[0045] The application method of high-temperature resistant ceramic ink is as follows: Using a 12-channel digital inkjet printer, the above-mentioned high-temperature resistant ceramic ink is printed onto the surface of a porcelain tile blank that has been coated with a base glaze to form a preset pattern. The printed blank is then placed in an infrared drying oven and dried at 230℃ for 5 minutes to allow the solvent to evaporate and the blocked isocyanate crosslinking agent to deblock, allowing it to crosslink and cure with hydroxyl acrylic resin. After cooling, a layer of transparent top glaze is applied onto the pattern layer using a bell-shaped glazing applicator, with a glaze application rate of 300g / m². 2 The brick blanks are then fed into a roller kiln and heated to 1100℃ at a uniform rate of 15℃ / min in an air atmosphere. The temperature is then maintained for 45 minutes before firing to obtain glazed tile products with decorative patterns.

[0046] Example 4 This embodiment provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that the hydroxyl acrylic resin obtained in Example 1 is replaced with an equal amount of the hydroxyl acrylic resin obtained in Example 4.

[0047] Example 5 This embodiment provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that the hydroxyl acrylic resin obtained in Example 1 is replaced with an equal amount of the hydroxyl acrylic resin obtained in Example 5.

[0048] Example 6 This embodiment provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that the hydroxyl acrylic resin obtained in Example 1 is replaced with an equal amount of the hydroxyl acrylic resin obtained in Example 6.

[0049] Example 7 This embodiment provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that the acrylic resin obtained in Preparation Example 7 is used to replace the hydroxyl acrylic resin obtained in Preparation Example 1.

[0050] Example 8 This embodiment provides a high-temperature resistant ceramic ink and its application method. The difference from Embodiment 1 is that no blocked isocyanate crosslinking agent is added to the raw materials of the high-temperature resistant ceramic ink.

[0051] Example 9 This embodiment provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that an equal amount of polyethylene glycol PEG-2000 is used to replace the hydroxyl acrylic resin obtained in Preparation Example 1.

[0052] Comparative Example 1 This comparative example provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that no fatty alcohol polyoxyethylene ether phosphate wetting agent is added during one cycle of grinding.

[0053] Comparative Example 2 This comparative example provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that no ultrafine talc powder is added in the secondary cyclic grinding.

[0054] Comparative Example 3 This comparative example provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that, in one cycle of grinding, an equal mass of ultrafine talc powder with a D50 of 1.5 μm is used to replace the fatty alcohol polyoxyethylene ether phosphate wetting agent (Rhodafac® RS-610).

[0055] Comparative Example 4 This comparative example provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that, in the secondary cycle grinding, an equal mass of fatty alcohol polyoxyethylene ether phosphate wetting agent (Rhodafac® RS-610) is used to replace the ultrafine talc powder with a D50 of 1.5μm.

[0056] Comparative Example 5 This comparative example provides a high-temperature resistant ceramic ink and its application method. The difference from Example 1 is that, in one cycle of grinding, an equal mass of fatty alcohol polyoxyethylene ether (Wuhan Kangqiong AEO-7) is used to replace the fatty alcohol polyoxyethylene ether phosphate wetting agent (Rhodafac® RS-610).

[0057] Performance testing and analysis: Experiment 1: Particle size distribution test Take approximately 0.5 g of each of the color paste samples obtained after secondary grinding in Examples 1-9 and Comparative Examples 1-5, and dilute them with propylene glycol methyl ether acetate to an opacity of 10%-15%. Use a laser particle size analyzer to measure their particle size distribution, record the D10, D50, and D90 values, and calculate the diameter distance according to the formula: Diameter distance = (D90-D10) / D50; the test results are shown in Table 1.

[0058] Note: D50 is the particle size value corresponding to a cumulative volume fraction of 50% on the particle size distribution curve, representing the average size of the powder particles.

[0059] D10 represents the particle size corresponding to 10% of the cumulative volume fraction, reflecting the distribution of the "fine particle end" in the particle group. The smaller the D10 value, the more ultrafine particles (including shell fragments) there are in the system.

[0060] D90 represents the particle size corresponding to 90% of the cumulative volume fraction, reflecting the distribution of the "coarse particle end" in the particle group. The larger the D90 value, the more coarse particles remain in the system.

[0061] The diameter distance is defined as (D90-D10) / D50, and is a dimensionless parameter for evaluating the width of the particle size distribution. The larger the diameter distance, the more severe the differentiation between coarse and fine particles and the wider the distribution; the smaller the diameter distance, the more concentrated and uniform the particle size distribution.

[0062] Experiment 2: Printing Fluency Test An industrial-grade ceramic inkjet printer (20μm nozzle diameter) was used to continuously print ink samples (printed patterns as full-width color blocks) on a ceramic body with a base glaze. The number of line breaks, nozzle blockages, and printing lengths were recorded during the printing process. When continuous line breaks or nozzle blockages caused obvious line stretching in the pattern, it was considered as a lack of smoothness. The results are shown in Table 1.

[0063] Table 1. Particle size distribution test results

[0064] Experiment 3: Firing and Color Development Performance Test The procedure was performed according to GB / T 3979-2008, "Methods for Measuring the Color of Objects". Following the methods, steps, and parameters described in the embodiments and comparative examples, high-temperature resistant ceramic ink was used to print circular solid-color patterns with a diameter of 3 cm onto a pre-glazed ceramic body using an inkjet printer. After applying a transparent top glaze, the body was fired. Three parallel samples were prepared for each group. A spectrophotometer (X-Rite Ci7800, D65 light source, 10° viewing angle) was used to measure five points in the central area of ​​each sample, and the average value was recorded. , , Value. Using Example 1 as the standard sample, the color saturation was calculated according to the following formula. :

[0065] Saturation The higher the value, the more vibrant (bright red) and richer the red color. The test results are shown in Table 2.

[0066] Test 4: Resistance to shrinkage cracking Place the fired color block on a black background and observe it with the naked eye (or wearing corrective glasses) at a 45° angle, 30cm directly below a 40W fluorescent lamp (or a D65 standard light source). Rate it according to the following standards: Level 3: The surface is smooth and flat, and no cracks or pinholes can be observed from any angle; Level 2: Sparse pinholes or fine lines (non-open cracks) can be identified under specific reflective angles, but do not affect the overall integrity of the pattern; Level 1: Visible superficial microcracks or a small number of pinholes (≤3 per cm) are present. 2 ); Level 0: Cracks are dense (network-like) and there are penetrating cracks.

[0067] The test results are shown in Table 2.

[0068] Table 2. Firing performance test results

[0069] Based on the test results in Tables 1 and 2, we can conclude that: Compared to Example 1, the color saturation of Example 4 (with too little styrene) is... A certain degree of decline was observed, with the shrinkage crack resistance grade dropping from level 3 to level 2. This indicates that insufficient styrene content significantly reduces the shrinkage crack resistance and color vibrancy of the ink layer. The reason may be that reduced styrene content leads to insufficient carbon skeleton formed after pyrolysis, which cannot adequately support the interparticle spaces, causing shrinkage cracking in some areas, resulting in powdering and a decrease in color vibrancy and saturation.

[0070] Color saturation in Example 5 (excessive styrene content) The color intensity decreased significantly, but the shrinkage crack resistance remained at level 3. This indicates that excessive styrene content leads to a noticeably duller color, but it still has an effect on supporting and buffering the ink layer structure. The reason may be that the carbon skeleton formed by excessive styrene failed to completely escape in the oxidation stage at 700-750℃, and the residual carbon was sealed after the glaze melted, causing localized graying and impairing the saturation of the bright red color.

[0071] Compared to Example 1, the color saturation of Example 6 (where butyl acrylate completely replaces styrene) is... The shrinkage crack resistance grade decreased significantly, dropping to level 1. This indicates that styrene is an essential component of hydroxyl acrylic resin. The reason for this may be that the lack of styrene as a carbon source prevents the formation of a continuous carbon skeleton after resin pyrolysis. Consequently, the ink layer loses support before the glaze melts, resulting in significant shrinkage cracking, causing some pigment particles to detach and compromising color vibrancy and saturation.

[0072] Color saturation of Example 7 (with butyl acrylate completely replacing hydroxyethyl methacrylate) The shrinkage crack resistance level dropped significantly, falling to level 1. This indicates that hydroxyl functional groups are a necessary prerequisite for cross-linking curing. The reason may be that resins without hydroxyl groups cannot undergo cross-linking reactions with blocked isocyanates, and cannot form a three-dimensional network after drying, resulting in insufficient initial strength of the ink layer and easy powder shedding. At the same time, the lack of preferential carbonization effect due to pyrolysis of the cross-linked network makes it difficult to form a carbon skeleton, which cannot suppress the powder shedding problem caused by shrinkage cracking, and the color saturation deteriorates.

[0073] Color saturation of Example 8 (without blocked isocyanate crosslinking agent) The strength decreased significantly, with the shrinkage crack resistance grade dropping to level 1. This indicates that the crosslinking agent is a key component in improving the shrinkage crack resistance of the ink layer. The reason for this may be that, without the curing effect of the crosslinking agent, the ink layer after drying is merely a physical film of thermoplastic resin, resulting in low strength; and during sintering, without a crosslinked network as the basis for the carbonization structure, the carbon skeleton is difficult to form.

[0074] Color saturation of Example 9 (using polyethylene glycol PEG-2000 instead of hydroxyl acrylic resin) The color development was significantly reduced, with the shrinkage crack resistance grade severely deteriorating to grade 1, and noticeable powdering. This indicates that the hydroxyl acrylic resin system in this application is a non-conventional resin substitute. The reason may be that polyethylene glycol has good film-forming properties, but leaves almost no carbon residue after pyrolysis, making it unable to form a carbon skeleton structure. The ink layer loses all support during sintering, resulting in the most severe shrinkage cracking and significant deterioration in color development.

[0075] Comparative Example 1 (single-stage grinding without phosphate wetting agent) had a higher D50, significantly increased D90 and particle size distribution, and a noticeably wider particle size distribution, resulting in lower color saturation. The decline may be due to the lack of coordination anchoring and steric hindrance effects of phosphate ester wetting agents, which causes the surface of newly formed particles to re-adhere, resulting in more coarse particles remaining, a wider particle size distribution, deterioration of printing smoothness, and a reduction in pattern integrity, color uniformity, and saturation.

[0076] Comparative Example 2 (secondary grinding without talc) showed a significantly reduced D10, a significantly increased radial distance, and a significantly reduced color saturation. A significant decrease. This may be due to the lack of talc buffer; the continuous stress on the qualified particles leads to excessive breakage of the shell, producing a large number of ultrafine fragments. The shell damage causes the chromophores to lose protection and oxidize and fade at high temperatures, resulting in severe damage to the color.

[0077] Comparative Example 3 (where talc was used to replace the phosphate ester wetting agent in a single grinding process) showed a higher D50, increased D90, D10, and increased radial distance, and lower color saturation. The decline is likely due to the fact that talc lacks the ability to penetrate microcracks and coordinate with newly formed surfaces, thus failing to effectively inhibit particle self-healing and agglomeration. Therefore, talc cannot replace the anti-self-healing function of phosphate ester wetting agents in the early stages of grinding, and adding talc in the early stages can actually negatively impact the grinding effect, leading to an increase in overall particle size and a deterioration in print smoothness.

[0078] Comparative Example 4 (secondary grinding with phosphate ester wetting agent replacing talc) showed a significantly reduced D10, increased diameter, and improved color saturation. A significant decrease indicates that phosphate ester wetting agents cannot replace the buffering and protective function of talc in the later stages of grinding. This may be because phosphate esters are small-molecule wetting agents and cannot form a physical buffer layer between particles like refined talc microparticles. This leads to the over-grinding of qualified particles, resulting in ultrafine particles or even shell rupture, thus deteriorating the color development effect.

[0079] Comparative Example 5 (with fatty alcohol polyoxyethylene ether AEO-7 replacing the phosphate ester wetting agent) has a coarser D50, increased diameter, and lower color saturation. The decrease indicates that ordinary nonionic surfactants cannot replace phosphate ester wetting agents. This may be because the AEO-7 molecule only contains ether bonds and terminal hydroxyl groups, lacking phosphate ester groups that can form strong coordination bonds with metal ions on the surface of the pigment shell. It can only rely on weak hydrogen bonding for physical adsorption, failing to quickly anchor on newly formed high-energy surfaces and reduce surface energy. This results in ineffective suppression of particle self-healing and agglomeration, an increase in coarse particles, and a wider particle size distribution, thus affecting printing smoothness and the uniformity and saturation of the fired color.

[0080] Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications to the technical solutions of this application by utilizing the methods and techniques disclosed above without departing from the spirit and scope of this application. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall fall within the protection scope of the technical solutions of this application.

Claims

1. A method for preparing a high-temperature resistant ceramic ink, characterized in that, The steps include the following: The coating pigment, phosphate ester wetting agent, and solvent are mixed in a mass ratio of 100:0.3~1.0:100~150 to obtain a premix; the premix is ​​then ground at an online speed of 7~10m / s to obtain a coarse abrasive with a D50 of 0.7~1.0μm. Add talc powder with a D50 of 1-2 μm to the coarse abrasive and mix well. The amount of talc powder is 0.1-0.5% of the mass of the pigment powder it coats. Then grind it at an online speed of 11-13 m / s until the D50 of the pigment powder it coats is 0.3-0.5 μm to obtain a pigment paste. By mixing color paste, resin carrier, dispersant and other additives, a high-temperature resistant ceramic ink is obtained.

2. The preparation method according to claim 1, characterized in that, The phosphate ester wetting agent is selected from one or more of alkyl phosphate esters, fatty alcohol polyoxyethylene ether phosphate esters, and alkylphenol polyoxyethylene ether phosphate esters.

3. The preparation method according to claim 1, characterized in that, The encapsulated color powder is selected from one or more of zirconium silicate-encapsulated cadmium sulfide selenide, zirconium dioxide-encapsulated cadmium sulfide, zirconium silicate-encapsulated cadmium sulfide, and zirconium dioxide-encapsulated cadmium sulfide, and its particle size is 2-5 μm.

4. The preparation method according to claim 1, characterized in that, In the grinding process, the diameter of the grinding media is 0.3 to 1.0 mm, and the diameter of the grinding disc is 100 to 250 mm.

5. The preparation method according to claim 1, characterized in that, The resin carrier is a hydroxy acrylic resin, which is prepared by free radical copolymerization of the following raw materials in parts by weight: 25-35 parts styrene, 10-20 parts hydroxy acrylate, 50-65 parts alkyl acrylate, 0.5-1.5 parts chain transfer agent, and 1-2 parts initiator.

6. The preparation method according to claim 5, characterized in that, The high-temperature resistant ceramic ink comprises the following raw materials in parts by weight: 100 parts color paste, 2-5 parts hydroxyl acrylic resin, 1-3 parts blocked isocyanate crosslinking agent, 5-10 parts dispersant, and 0.3-2 parts defoamer; the unblocking temperature of the blocked isocyanate crosslinking agent is 120-160℃.

7. The preparation method according to claim 5, characterized in that, The number-average molecular weight of the acrylic resin is 8000 to 15000.

8. The preparation method according to claim 5, characterized in that, The hydroxy acrylate is selected from at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, and hydroxypropyl acrylate; the alkyl acrylate is selected from at least one of ethyl acrylate, butyl acrylate, or isooctyl acrylate.

9. A high-temperature resistant ceramic ink, characterized in that, It is prepared by any one of the preparation methods described in claims 1 to 8.

10. The application method of the high-temperature resistant ceramic ink prepared by any one of the preparation methods according to claims 1 to 8, characterized in that, The steps include the following: The prepared high-temperature resistant ceramic ink is used to print a preset pattern on the surface of a ceramic blank through inkjet printing. The printed blank is dried at 150-250°C to deblock the blocked isocyanate crosslinking agent and crosslink and cure it with hydroxyl acrylic resin. Then, a layer of transparent glaze is applied to the surface of the patterned body, and the body is then sent into the kiln. Under an oxidizing atmosphere, the temperature is uniformly raised to 1000-1100℃ at a heating rate of 5-15℃ / min, and then held for firing to obtain a patterned ceramic product.

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