A self-cleaning photocurable ceramic slurry, a preparation method thereof, and a self-cleaning method

Abstract

The present invention provides a self-cleaning photocurable ceramic slurry, a preparation method thereof and a self-cleaning method. The self-cleaning photocurable ceramic slurry comprises ceramic powder and a photosensitive prepolymer solution; the solid-phase mass content of the ceramic powder in the self-cleaning photocurable ceramic slurry is 40% to 70%. The photosensitive prepolymer solution comprises a photosensitive resin, a photoinitiator, a thermosensitive phase change agent, a leveling agent and a dispersant. It has the following advantages: (1) In the self-cleaning photocurable ceramic slurry of the present invention, the thermosensitive phase change agent is used to replace the thickener, which can meet the high solid-phase content of the system, and at the same time has excellent stability and photocuring printing process performance. (2) The self-cleaning photocurable ceramic slurry in the present invention not only has the advantages of easy availability of raw materials, simple preparation steps and high yield, but also has simple, environmentally friendly, efficient cleaning steps and is very suitable for industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical fields of preparation of photocurable ceramic slurries and additive manufacturing, and particularly relates to a self-cleaning photocurable ceramic slurry, a preparation method thereof, and a self-cleaning method. Background Art

[0002] Ceramic materials have many excellent properties such as high melting point, high hardness, high wear resistance, and oxidation resistance, and are widely used in fields such as aerospace, automotive manufacturing, petrochemical industry, and biomedicine. With the diversification of application scenarios of ceramic materials and the individuation of application requirements, the requirement for the complexity of the structure of ceramic parts is also getting higher and higher. In traditional processes, it is extremely difficult to perform subtractive operations such as cutting on ceramic parts, and the preparation cycle of the mold is relatively long. The mold opening step is limited in operation when facing complex structures, which severely restricts the preparation of complex structure ceramic parts and limits their applications.

[0003] Additive manufacturing technology obtains a three-dimensional structure by layer-by-layer stacking, and is an ideal technology for preparing complex structure ceramic parts. Among them, the printing accuracy of stereolithography (SLA) technology can reach 20um. It is not only one of the most mature printing processes in additive manufacturing technology, but also one of the most widely studied additive manufacturing processes for preparing complex structure ceramic parts at present. As the raw material of the SLA printing process, the photocurable ceramic slurry mainly consists of ceramic powder, photosensitive resin, dispersant, photoinitiator, and other functional additives. In order to improve the thixotropy of the slurry system and meet its process printing performance, a thickener is often added to the system. Due to the physical entanglement of random coils caused by the disordered molecular conformation, the viscosity of the slurry system is relatively large in the non-shearing state. In the shearing state, the thickener molecules stretch from the cluster state into a linear state, and the viscosity of the slurry decreases. The addition of the thickener provides good rheology for the slurry and improves the printing process performance of the photocurable ceramic slurry system. However, after printing is completed, the residual slurry in the printed ceramic green body is in a non-shearing state, and the mechanical properties of the printed ceramic green body are weak. Therefore, it is often difficult to clean the residual slurry in the green body, especially in complex flow channel structures. This not only affects the processing efficiency, but also brings many difficulties to the subsequent machining steps after sintering and forming. For ceramic parts with internal complex flow channel structures, such as filters, radiators, sweating devices, etc., using the SLA printing process will put forward higher requirements for the cleaning of the photocurable printing slurry and the residual slurry in the green body. Developing a new type of photocurable ceramic printing slurry that can simultaneously achieve efficient and simple cleaning of the residual slurry in the green body while meeting good process performance is a major problem that urgently needs to be solved in the photocurable printing of complex flow channel structures of ceramics at present, and is also the key to improving the preparation efficiency of additive manufacturing of ceramic parts.

[0004] Implementing the cleaning of SLA printed ceramic slurries by flushing with cleaning agents is a commonly used method at present. The cleaning agents are usually solvents such as ethanol, isopropanol, acetone, etc., but the cleaning effect is generally average. In order to achieve a better cleaning effect, strong cleaning agents are also used, usually strong polar solvents such as N-methylpyrrolidone, N,N-dimethylacetamide, etc. However, the long cleaning process may cause certain damage to the green body and also cause environmental pollution. On the other hand, for complex internal flow channels, the cleaning agent method is often inefficient and has a high cleaning difficulty, and the effect is not ideal in actual cleaning applications. Starting from the slurry formulation design, while ensuring excellent photocuring performance and rheological properties of the slurry system, and at the same time meeting the easy cleaning of the residual slurry, developing a photocurable ceramic slurry system with self-cleaning function to achieve an environmentally friendly, efficient and simple ceramic slurry cleaning method is the common goal pursued by the scientific research community and the industrial community. Summary of the Invention

[0005] In view of the defects existing in the prior art, the present invention provides a self-cleaning photocurable ceramic slurry, a preparation method thereof and a self-cleaning method, which can effectively solve the above problems.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The first object of the present invention is to provide a self-cleaning photocurable ceramic slurry, and the self-cleaning photocurable ceramic slurry includes ceramic powder and a photosensitive prepolymer solution; the solid-phase mass content of the ceramic powder in the self-cleaning photocurable ceramic slurry is 40% to 70%.

[0008] Preferably, the photosensitive prepolymer solution includes a photosensitive resin, a photoinitiator, a thermosensitive phase-change agent, a leveling agent and a dispersant.

[0009] Preferably, the weight ratio of each component of the photosensitive prepolymer solution is:

[0010]

[0011] Preferably, the photosensitive resin is one or a mixture of several of trimethylolpropane triacrylate, 1,6-hexanediol diacrylate or polyester acrylate prepolymer;

[0012] The photoinitiator is one or a mixture of several of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoyl phenylphosphonate or 1-hydroxycyclohexyl phenyl ketone;

[0013] The thermosensitive phase-change agent is one or a mixture of several of polyethylene glycol 1000, polyethylene glycol 2000, polycaprolactone, ethylene-vinyl acetate copolymer or poly(hexylene adipate) copolymer;

[0014] The leveling agent is one or a mixture of several of isophorone, diacetone alcohol, acrylic leveling agent or silicone leveling agent;

[0015] The dispersant is one or a mixture of several of diatom mud dispersant SP-710, diatom mud dispersant BYK-111, triethylhexyl phosphate, sodium dodecyl sulfate, methyl pentanol, cellulose derivative, polyacrylamide, guar gum or fatty acid polyethylene glycol ester.

[0016] Preferably, the ceramic powder is one or a mixture of several of silicon carbide powder, zirconia powder, alumina powder or silicon nitride powder, and the particle size of the ceramic powder is 10 nm to 50 μm.

[0017] The second object of the present invention provides a preparation method of the self-cleaning photocurable ceramic slurry described above, including the following steps:

[0018] Step S1, preparing a photosensitive prepolymer solution:

[0019] Heat the formula amount of thermosensitive phase change agent to melt at 80-120 °C, and then add the formula amounts of photosensitive resin, photoinitiator, leveling agent and dispersant respectively, and stir well until evenly mixed to prepare a photosensitive prepolymer solution;

[0020] Step S2, preparing a self-cleaning photocurable ceramic slurry

[0021] Mix the prepared photosensitive prepolymer solution and the formula amount of ceramic powder evenly to prepare a self-cleaning photocurable ceramic slurry;

[0022] The prepared self-cleaning photocurable ceramic slurry is stored at low temperature in an environment of 4-10 °C;

[0023] When in need of use, place the self-cleaning photocurable ceramic slurry stored at low temperature in a room temperature environment until its temperature reaches the room temperature environment, and then use the self-cleaning photocurable ceramic slurry as a printing material to print a ceramic green body with a complex internal structure through a printing process.

[0024] The third object of the present invention provides a self-cleaning method for a ceramic green body prepared from the self-cleaning photocurable ceramic slurry described above, including the following steps:

[0025] Step S1, printing a ceramic green body with the self-cleaning photocurable ceramic slurry, heating the ceramic green body to the phase change temperature of the thermosensitive phase change agent, and the residual slurry in the internal pores of the ceramic green body is fully heated, so that the thermosensitive phase change agent undergoes a phase change, thereby reducing the viscosity of the residual slurry in the internal pores and making it easy to flow, and automatically flowing out under the action of gravity;

[0026] Step S2: Rinse the internal pores of the green ceramic part with a cleaning solvent until the residual slurry in the internal pores of the green ceramic part is completely cleaned up.

[0027] The self-cleaning photocurable ceramic slurry, its preparation method and self-cleaning method provided by the present invention have the following advantages:

[0028] (1) In the self-cleaning photocurable ceramic slurry of the present invention, a thermosensitive phase change agent is used to replace the thickener, which can meet the high solid content of the system and at the same time has excellent stability and photocuring printing process performance.

[0029] (2) The self-cleaning photocurable ceramic slurry in the present invention, in addition to having the advantages of easy availability of raw materials, simple preparation steps and high yield, its cleaning steps are simple, environmentally friendly, efficient and very suitable for industrial production. Description of the Drawings

[0030] Figure 1 It is the overall process diagram of the self-cleaning photocurable ceramic slurry, its preparation method and self-cleaning method provided by the present invention.

[0031] Figure 2 It is the comparison diagram of the thermogravimetric performance of the photosensitive prepolymer provided by the present invention and the traditional photosensitive prepolymer.

[0032] Figure 3 It is the comparison diagram of the photocuring performance of the photosensitive prepolymer provided by the present invention and the traditional photosensitive prepolymer.

[0033] Figure 4 It is the comparison diagram of the room temperature rheological properties of the photocurable ceramic slurry provided by the present invention and the traditional photocurable ceramic slurry. Detailed Embodiments

[0034] The following embodiments are only the preferred technical solutions of the present invention and are not used to limit the present invention in any way. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0035] The purpose of the present invention is to overcome the deficiencies in the prior art, design a photocurable ceramic slurry suitable for printing by the sinking SLA process, and meet the self-cleaning of the residual highly viscous slurry in the complex flow channel structure of the printed green body, and can solve the problem of difficult cleaning of the residual slurry in the green body in the non-shearing state under the condition of meeting the good printing process performance of the slurry; the present invention also solves and improves the problems of poor cleaning effect, low cleaning efficiency and non-environmental protection in the traditional scheme.

[0036] Specifically, the present invention provides a self-cleaning photocurable ceramic slurry, which includes ceramic powder and a photosensitive prepolymer solution; the solid-phase mass content of the ceramic powder in the self-cleaning photocurable ceramic slurry is 40% to 70%. The photosensitive prepolymer solution includes a photosensitive resin, a photoinitiator, a thermosensitive phase-change agent, a leveling agent, and a dispersant. The weight ratio of each component of the photosensitive prepolymer solution is:

[0037]

[0038] In the present invention, the photosensitive resin is one or a mixture of several of trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, or polyester acrylate prepolymer;

[0039] The photoinitiator is one or a mixture of several of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoyl phenylphosphonate, or 1-hydroxycyclohexyl phenyl ketone;

[0040] The thermosensitive phase-change agent is a thermoplastic polymer with a glass transition temperature of 60°C to 100°C, specifically one or a mixture of several of polyethylene glycol 1000, polyethylene glycol 2000, polycaprolactone, ethylene-vinyl acetate copolymer, or poly(hexamethylene adipate) copolymer; Specifically, in the self-cleaning photocurable ceramic slurry provided by the present invention, a thermosensitive phase-change agent is innovatively adopted. The thermosensitive phase-change agent is an additive that presents a solid state at room temperature and undergoes a phase change to a liquid state at high temperature. At room temperature, the thermosensitive phase-change agent presents solid particles in the slurry system. Due to the intermolecular attraction and electrostatic attraction between the particles and between the solid particles and the liquid resin, it can meet the excellent stability, rheology, and process performance of the slurry system, replacing the thickening effect of the thickener. After the green body printing step is completed, the green body is heated to the phase change temperature of the thermosensitive phase-change agent, and the thermosensitive phase-change agent will change from a solid state to a liquid state, releasing the intermolecular attraction and electrostatic attraction, and the viscosity of the slurry system becomes smaller and it is easy to flow, enabling the efficient cleaning of the residual slurry in the green body. By using a thermosensitive phase-change agent instead of a thickener in the photocurable ceramic slurry system, it can meet the excellent printing process performance of the slurry system and achieve the efficient self-cleaning of high-viscosity slurries for complex pore structure ceramics.

[0041] The leveling agent is one or a mixture of several of isophorone, diacetone alcohol, acrylic leveling agent, or silicone leveling agent;

[0042] The dispersant is one or a mixture of several of diatom mud dispersant SP-710, diatom mud dispersant BYK-111, triethylhexyl phosphate, sodium dodecyl sulfate, methyl amyl alcohol, cellulose derivatives, polyacrylamide, guar gum, or fatty acid polyethylene glycol ester.

[0043] In the present invention, the ceramic powder is one or a mixture of several of silicon carbide powder, zirconia powder, alumina powder or silicon nitride powder, and the particle size of the ceramic powder is 10 nm to 50 μm.

[0044] The present invention also provides a method for preparing a self-cleaning photocurable ceramic slurry, referring to Figure 1 , which includes the following steps:

[0045] Step S1, preparing a photosensitive prepolymer solution:

[0046] Heat and melt the thermosensitive phase change agent in a formula amount at 80 to 120 °C, and then add the photosensitive resin, photoinitiator, leveling agent and dispersant in a formula amount respectively, and stir well until evenly mixed to prepare a photosensitive prepolymer solution;

[0047] In this step, after the thermosensitive phase change agent is heated and melted, it becomes liquid, and can be more evenly mixed with other liquid organic components.

[0048] Step S2, preparing a self-cleaning photocurable ceramic slurry

[0049] Mix the prepared photosensitive prepolymer solution and the ceramic powder in a formula amount evenly. For example, put the prepared photosensitive prepolymer solution and the ceramic powder in a formula amount into a self-rotating and revolving homogenizer and mix for 10 to 20 minutes to make them evenly mixed, so as to prepare a self-cleaning photocurable ceramic slurry; specifically, during the 10 to 20 minutes of mixing the photosensitive prepolymer solution and the ceramic powder in the self-rotating and revolving homogenizer, the heat generated by friction is sufficient to keep the thermosensitive phase change agent in a liquid state, and the intermolecular interaction force and viscosity in the system are reduced, realizing efficient mixing.

[0050] The prepared self-cleaning photocurable ceramic slurry needs to be immediately stored at a low temperature in an environment of 4 to 10 °C; for example, immediately placed in a refrigerator for cooling and storage for later use. The reason for low-temperature storage is that after the fully mixed photocurable ceramic slurry is put into the refrigerator and cooled immediately, the thermosensitive phase change agent in the system changes from liquid to solid, and the viscosity of the system increases, so that the powder in the system does not settle, ensuring the uniformity of the slurry system.

[0051] When in need of use, place the self-cleaning photocurable ceramic slurry stored at low temperature in a room-temperature environment until its temperature reaches the room-temperature environment. Then, use the self-cleaning photocurable ceramic slurry as a printing material to print a green ceramic part with a complex internal structure through a printing process. Specifically, take out the self-cleaning photocurable ceramic slurry stored in the refrigerator until the system temperature reaches room temperature, and then print a green ceramic part with a complex internal structure through the SLA process. When printing a green ceramic part using the SLA process, the self-cleaning photocurable ceramic slurry needs to be taken out of the refrigerator and waited for 30 - 60 minutes. At low temperature, the thermosensitive phase change agent molecules are still in a frozen state, and in a non-shearing state, the viscosity of the slurry system is relatively large, which is not conducive to printing. After the slurry system returns to room temperature, good viscosity and printability can be achieved, and then it can be used for SLA printing operations.

[0052] The present invention also provides a self-cleaning method for a green ceramic part prepared from the self-cleaning photocurable ceramic slurry, including the following steps:

[0053] Step S1, print a green ceramic part using the self-cleaning photocurable ceramic slurry, and heat the green ceramic part to the phase transition temperature of the thermosensitive phase change agent. For example, place the green ceramic part in an oven at 100 - 120 °C for 30 - 60 minutes. The residual slurry in the internal pores of the green ceramic part is fully heated, causing the thermosensitive phase change agent to undergo a phase change, thereby reducing the viscosity of the residual slurry in the internal pores and making it easy to flow, and automatically flowing out under the action of gravity. Specifically, after being heated at a high temperature of 100 - 120 °C for 30 - 60 minutes, the thermosensitive phase change agent in the residual slurry in the internal pores of the green ceramic part can change from a solid state to a liquid state, the viscosity of the residual slurry decreases in a non-shearing state, the liquid resin and solid powder are easily separated, and the slurry is easily cleaned and flowed out.

[0054] Step S2, clean the inside of the pores by solvent assistance:

[0055] After most of the unreacted slurry flows out of the pores of the green body, use a cleaning solvent such as isopropanol or ethanol to rinse the inside of the pores of the green ceramic part until the residual slurry in the inside of the pores of the green ceramic part is completely cleaned.

[0056] The present invention provides a self-cleaning photocurable ceramic slurry, a preparation method thereof, and a self-cleaning method. By using a thermosensitive phase change agent to replace the thickener in the traditional scheme, a self-cleaning photocurable ceramic slurry is prepared. On the one hand, it can meet the excellent stability, rheological properties, and process performance of the slurry system and is suitable for additive printing; on the other hand, the printed green ceramic part has high self-cleaning performance.

[0057] The following verifies the advantages of the present invention compared with the traditional scheme through Comparative Example 1, Comparative Example 2, and Comparative Example 3:

[0058] Comparative Example 1:

[0059] This comparative example was used to investigate the effects of the temperature-sensitive phase-changing agent and the thickener on the properties of the prepared photosensitive prepolymer solution:

[0060] Experimental example: Add 200 g of the temperature-sensitive phase-changing agent polyethylene glycol (PEG-2000) to a 1000 ml black wide-mouth bottle equipped with mechanical stirring, heat up and maintain the system temperature at 120 °C, and then sequentially add 800 g of the photosensitive resin trimethylolpropane triacrylate, 20 g of the photoinitiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 120 g of the dispersant diatomaceous earth SP-710, and 120 g of the leveling agent isophorone. Stir in the dark for 60 min until it becomes a homogeneous liquid state to prepare a photosensitive prepolymer solution, denoted as photosensitive prepolymer solution B1.

[0061] Control example:

[0062] Add 1000 g of the photosensitive resin trimethylolpropane triacrylate, 20 g of the photoinitiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 120 g of the dispersant diatomaceous earth SP-710, 120 g of the leveling agent isophorone, and 33.03 g of the thickener BYK-410 to a 1000 ml black wide-mouth bottle equipped with mechanical stirring in sequence. Stir in the dark for 60 min until it becomes a homogeneous state to prepare a photosensitive prepolymer solution, denoted as photosensitive prepolymer solution A1.

[0063] Therefore, by using the preparation method of the photosensitive prepolymer solution with the temperature-sensitive phase-changing agent raw material of the present invention, photosensitive prepolymer solution B1 was prepared. While by using the traditional preparation method of the photosensitive prepolymer solution with the thickener raw material, photosensitive prepolymer solution A1 was prepared.

[0064] Measure the viscosities of photosensitive prepolymer solution A1 and photosensitive prepolymer solution B1 under non-shearing conditions at room temperature. The viscosity test was carried out in accordance with GB / T 12007.4-1989. The results were as follows: the viscosity of photosensitive prepolymer solution A1 was 34.5 cp. The viscosity of photosensitive prepolymer solution B1 was 180 cp.

[0065] Measure the photocuring properties of photosensitive prepolymer solution A1 and photosensitive prepolymer solution B1. The photocuring properties were represented by the resin cured layer thickness obtained when the fixed light intensity was 80 and the light irradiation times were 2 s, 4 s, 6 s, 8 s, and 10 s respectively. The results were as Figure 3 shown.

[0066] Measure the thermal weight loss properties of photosensitive prepolymer solution A1 and photosensitive prepolymer solution B1. The test method was as follows: Carry out the thermal weight loss property test on the completely cured resin. The test conditions were in an N2 atmosphere with a heating rate of 5 °C / min, and measure the mass after weight loss. The results were as Figure 2 shown.

[0067] By comparing the viscosity values of the photosensitive prepolymer solution A1 and the photosensitive prepolymer solution B1 at room temperature in a non-shearing state, it can be seen that the viscosity of the photosensitive prepolymer solution B1 prepared in the present invention has a slight increase compared to the viscosity of the traditional photosensitive prepolymer solution A1; the photocuring activity of the photosensitive prepolymer solution B1 prepared in the present invention has a slight decrease compared to the photocuring activity of the traditional photosensitive prepolymer solution A1; however, through the comparison of the thermal weight loss performance, it is obtained that the photosensitive prepolymer solution B1 prepared in the present invention has a more gentle weight loss curve than the traditional photosensitive prepolymer solution A1. Therefore, the photosensitive prepolymer solution B1 prepared in the present invention is beneficial to reducing the cracking risk of the printed three-dimensional ceramic green body in the subsequent debinding step.

[0068] Comparative Example 2:

[0069] This comparative example is used to investigate the performance differences of photocurable ceramic slurries prepared by different methods:

[0070] Test Example:

[0071] Using the photosensitive prepolymer solution B1 prepared in Comparative Example 1 as the raw material, 100 g of the photosensitive prepolymer solution B1 and 308 g of 45-μm silicon carbide powder were added to a 500-ml wide-mouth bottle. After simple manual mixing, it was placed in a self-rotating and revolving stirrer and mixed at 2000 r / min for 5 min until uniform to obtain a photocurable ceramic slurry, denoted as: photocurable ceramic slurry B10.

[0072] The prepared photocurable ceramic slurry B10 was promptly placed in a refrigerator for refrigerated storage, and before being applied to the SLA printing technology, the photocurable ceramic slurry B10 was taken out of the refrigerator and restored to room temperature before printing operations.

[0073] Control Example:

[0074] Using the photosensitive prepolymer solution A1 prepared in Comparative Example 1 as the raw material, 100 g of the photosensitive prepolymer solution A1 and 308 g of 45-μm silicon carbide powder were added to a 500-ml wide-mouth bottle. After simple manual mixing, it was placed in a self-rotating and revolving stirrer and mixed at 2000 r / min for 5 min until uniform to obtain a photocurable ceramic slurry, denoted as: photocurable ceramic slurry A10.

[0075] Therefore, by using the method of the present invention, the photocurable ceramic slurry B10 was prepared. While by using the traditional method, the photocurable ceramic slurry A10 was prepared.

[0076] Test the room-temperature rheological properties of the photocurable ceramic slurry B10 and the photocurable ceramic slurry A10, that is: test the viscosities of the two photocurable ceramic slurries at room temperature at rotational speeds from 0 to 150 r / min. The results are as Figure 4 shown.

[0077] From Figure 4It can be seen that under the room temperature non-shearing state (rotation speed from 0 to 90 r / min), the viscosity of the photocurable ceramic slurry B10 prepared by the present invention is higher than that of the photocurable ceramic slurry A10 prepared by the traditional method; however, under the room temperature shearing state (rotation speed higher than 90 r / min), the photocurable ceramic slurry B10 prepared by the present invention has excellent rheological properties, shows shear thinning characteristics, and has excellent printing process performance.

[0078] Comparative Example 3:

[0079] This comparative example is used to investigate the difference in the cleaning performance of the ceramic green body parts prepared by different methods:

[0080] Test Example:

[0081] Using the photocurable ceramic slurry B10 prepared in Comparative Example 2 as the printing material, adjusting the printing parameters, and applying it to the stereolithography process to prepare a ceramic green body part, denoted as: ceramic green body part B11. Among them, the ceramic green body part is a three-dimensional condensing pipe part.

[0082] Using the photocurable ceramic slurry A10 prepared in Comparative Example 2 as the printing material, adjusting the printing parameters, and applying it to the stereolithography process to prepare a ceramic green body part, denoted as: ceramic green body part A11. Among them, the ceramic green body part is a three-dimensional condensing pipe part.

[0083] Put the prepared ceramic green body part B11 into an oven, set the temperature to 120 °C, wait statically for 20 min, and then use isopropanol for auxiliary cleaning.

[0084] Put the prepared ceramic green body part A11 into an oven, set the temperature to 120 °C, wait statically for 20 min, and then use isopropanol for auxiliary cleaning.

[0085] Record the outflow state and time of the residual photocurable ceramic slurry in the pores of the ceramic green body parts B11 and A11 respectively. The results are shown in Table 1:

[0086] Table 1 Comparison of the cleaning performance of ceramic green body parts

[0087] ceramic green body cleaning method cleaning effect residual slurry outflow time A11 heating + cleaning agent not obvious very long B11 heating + cleaning agent obvious 10 min

[0088] It can be seen from Table 1 that for the ceramic green body parts prepared by the present invention, the residual photocurable ceramic slurry has high self-cleaning ability and good solubility in isopropanol solvent. For the ceramic green body parts prepared by the present invention, the residual photocurable ceramic slurry can achieve efficient and simple self-cleaning ability in complex pores.

[0089] Compared with the prior art, the technology of the present invention has the following advantages:

[0090] (1) In the self-cleaning photocurable ceramic slurry of the present invention, a thermosensitive phase change agent is used to replace the thickener, which can meet the high solid content of the system and at the same time has excellent stability and photocurable printing process performance.

[0091] (2) The self-cleaning photocurable ceramic slurry in the present invention not only has the advantages of easy availability of raw materials, simple preparation steps and high yield, but also has simple, environmentally friendly, efficient cleaning steps and is very suitable for industrial production.

[0092] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A self-cleaning method for a green ceramic body prepared from a self-cleaning photocurable ceramic slurry, characterized in that, The self-cleaning photocurable ceramic slurry comprises ceramic powder and photosensitive prepolymer liquid; the solid phase mass content of the ceramic powder in the self-cleaning photocurable ceramic slurry is 40% to 70%; the photosensitive prepolymer liquid comprises a photosensitive resin, a photoinitiator, a temperature-sensitive phase change agent, a leveling agent and a dispersant; A self-cleaning method for a ceramic green blank prepared by using a self-cleaning light-cured ceramic slurry comprises the following steps: Step S1, using a self-cleaning light-curing ceramic slurry to print a ceramic blank, heating the ceramic blank to the phase change temperature of the temperature-sensitive phase change agent, and sufficiently heating the residual slurry in the internal pores of the ceramic blank to cause the temperature-sensitive phase change agent to undergo a phase change, thereby reducing the viscosity of the residual slurry in the internal pores, making it easy to flow, and automatically flowing out under the action of gravity; Step S2, using a cleaning solvent to rinse the internal channels of the ceramic green blank until the residual slurry in the internal channels of the ceramic green blank is completely cleaned.

2. The self-cleaning method of a green ceramic part prepared from a self-cleaning photocurable ceramic slurry according to claim 1, characterized in that The weight ratio of each component of the photosensitive prepolymer liquid is:

3. The self-cleaning method of a green ceramic body prepared by using a self-cleaning photocurable ceramic slurry according to claim 1, characterized in that, The photosensitive resin is one or a mixture of trimethylolpropane triacrylate, 1,6-hexanediol diacrylate or polyester acrylate prepolymer; The photoinitiator is one or a mixture of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate or 1-hydroxycyclohexylphenyl ketone; The temperature-sensitive phase change agent is one or a mixture of polyethylene glycol 1000, polyethylene glycol 2000, polycaprolactone, ethylene-vinyl acetate copolymer or poly(hexanediol adipate) copolymer; The leveling agent is one or a mixture of isophorone, diacetone alcohol, acrylic leveling agent or silicone leveling agent; The dispersant is one or a mixture of several of diatom mud dispersant SP-710, diatom mud dispersant BYK-111, triethylhexyl phosphoric acid, sodium lauryl sulfate, methyl amyl alcohol, cellulose derivatives, polyacrylamide, guar gum or fatty acid polyethylene glycol ester.

4. The self-cleaning method of a green ceramic body prepared from a self-cleaning photocurable ceramic slurry according to claim 1, characterized in that, The ceramic powder is one of silicon carbide powder, zirconium oxide powder, aluminum oxide powder or silicon nitride powder or a mixture of the two or more thereof, and the particle size of the ceramic powder is 10nm to 50um.

5. The self-cleaning method of a green ceramic body prepared by using a self-cleaning photocurable ceramic slurry according to claim 1, characterized in that, The method for preparing the self-cleaning light-cured ceramic slurry comprises the following steps: Step S1, preparing a photosensitive prepolymer solution: The formulated amount of the thermosensitive phase change agent is heated to melt at 80-120° C., and then the formulated amount of the photosensitive resin, the photoinitiator, the leveling agent and the dispersant are respectively added, and the mixture is stirred until uniformly mixed to prepare a photosensitive prepolymer solution; Step S2, preparing self-cleaning light-cured ceramic slurry The prepared photosensitive prepolymer liquid and the formulated amount of ceramic powder are evenly mixed to prepare a self-cleaning light-cured ceramic slurry; The prepared self-cleaning light-curing ceramic slurry is stored at a low temperature of 4 to 10°C; When in need of use, place the self-cleaning photocurable ceramic slurry stored at low temperature in a room-temperature environment until its temperature reaches that of the room-temperature environment. Then, use the self-cleaning photocurable ceramic slurry as a printing material to print a green ceramic part with a complex internal structure through a printing process.

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