A novel water-washable photopolymerizable 3D printing material and its preparation method

Abstract

This invention discloses a novel washable photocurable 3D printing material and its preparation method, relating to the field of 3D printing photosensitive resin materials technology. Utilizing the properties of polyethylene glycol diacrylate and glyceryl acrylate, this invention constructs a strong and hydrolyzable network structure, improving the washability and strength of the composition. By mechanically alloying bismuth powder, indium powder, and gallium powder, a low-melting-point metal material with thiol groups on its surface is prepared, improving its compatibility and dispersibility with the resin. This metal material acts as a reinforcing agent in photocuring crosslinking, significantly enhancing the mechanical strength of the 3D printing material. During the heat treatment stage after cleaning, the low melting point of the metal material melts and bonds the cured resin network and ceramic particles, further improving the mechanical strength of the 3D printing material.

Description

Technical Field

[0001] This invention relates to the field of 3D printing photosensitive resin materials technology, specifically to a novel washable photocurable 3D printing material and its preparation method. Background Technology

[0002] Photopolymer 3D printing technology has shown great potential in precision manufacturing, medical, dental, and jewelry fields due to its high precision, high efficiency, and high surface quality. The core of this technology lies in photopolymerizable liquid resin materials. However, existing commercially available photopolymer resins, while pursuing high performance, especially high mechanical strength, often face a key bottleneck: the difficulty of post-processing cleaning and the challenge of simultaneously maintaining mechanical properties.

[0003] To facilitate the removal of uncured resin residue after printing, the development of washable resins is crucial. Currently, the mainstream approach involves introducing hydrophilic components, such as polyethylene glycol or its derivatives. While these materials significantly improve washability, their high hydrophilicity typically weakens the intermolecular forces within the cured network, sacrificing the material's crosslinking density and final mechanical strength. Existing technologies struggle to achieve efficient and thorough washability while simultaneously imparting the high strength and rigidity required for practical applications.

[0004] Adding inorganic fillers is a common strategy to improve the mechanical properties of photocurable resins. However, the dispersibility and compatibility of these reinforcements in the resin matrix pose significant challenges. Micro and nano fillers are prone to aggregation, especially in high-viscosity resin systems, leading to stress concentration and potentially reducing strength. The interfacial bonding between inorganic fillers and the organic resin matrix is ​​typically weak, resulting in low stress transfer efficiency and failing to fully realize the reinforcing potential of the fillers. While surface modification of fillers is a common method to improve compatibility, its effectiveness is often limited and the process is complex.

[0005] Therefore, the current field of photopolymer 3D printing materials urgently needs to overcome the following key limitations: develop a new material system that can effectively and synergistically resolve the contradiction between "highly efficient washability" and "high mechanical strength"; at the same time, the introduced reinforcement must have excellent resin compatibility and dispersion stability, and be able to fully utilize the post-processing steps of the 3D printing process to achieve a strong and tough bond with the resin matrix, thereby significantly improving the comprehensive mechanical properties of the material without adding complex processes. Summary of the Invention

[0006] The purpose of this invention is to provide a novel washable photocurable 3D printing material and its preparation method to solve the problems existing in the prior art.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a novel washable photopolymerizable 3D printing material, comprising, by weight:

[0008] 20-40 parts of photosensitive oligomer;

[0009] 5-10 parts of hydroxyethyl methacrylate;

[0010] 1-6 parts of glyceryl acrylate;

[0011] 10-15 parts of polyethylene glycol diacrylate;

[0012] 1-5 parts of trimethylolpropane triacrylate;

[0013] 5-10 parts of low melting point alloy powder;

[0014] 5-10 parts of ceramic powder;

[0015] 1-3 parts of photoinitiator;

[0016] 0.1-1 part of hydrophilic fumed silica;

[0017] The preparation method of the low melting point alloy powder is as follows: bismuth powder, indium powder and gallium powder are loaded into a high-energy ball mill jar, ground for 20-40 hours under argon protection, and then subjected to surface modification treatment.

[0018] This invention utilizes the physical swelling of polyethylene glycol diacrylate and the polyhydroxy hydration of glycerol acrylate to synergistically construct a high-strength but water-destructible network, thereby simultaneously improving the washability and strength of the composition.

[0019] Furthermore, the hydrophilic fumed silica has an average particle size of 5-25 nm and a specific surface area of ​​200-400 m². 2 / g, Manufacturer: Evonik Degussa, Brand: AEROSIL 300.

[0020] Furthermore, the photosensitive oligomer is one or a combination of more than one of waterborne polyurethane acrylic resin, waterborne polyester acrylic resin, and waterborne epoxy acrylic resin.

[0021] Furthermore, the photoinitiator is at least one selected from 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, benzoin ether, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, isopropylthioxanthonone, 2-chlorothioxanthonone, 2,4-diethylthioxanthonone, and 2-ethylanthraquinone.

[0022] Furthermore, the polyethylene glycol diacrylate has a molecular weight of 400 and is derived from PEG400DA from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.

[0023] Furthermore, the ceramic powder is one or more of SiO2, Al2O3, MgO, CaO, Sm2O3, and ZrO2.

[0024] Furthermore, the bismuth powder, indium powder, and gallium powder have a particle size of 10-30 μm.

[0025] Furthermore, the mass ratio of the bismuth powder, indium powder, and gallium powder is 60:30-35:22-25.

[0026] Furthermore, the surface modification treatment specifically involves: dissolving mercaptopropyltrimethoxysilane (specifically KH-590 produced by Guangzhou Zhongjie New Materials Co., Ltd.), anhydrous ethanol, and water, adjusting the pH, and controlling the hydrolysis time to 1-2 hours; immersing the ground alloy in the hydrolyzed silane coupling agent alcohol-water solution for 30 minutes, and then filtering and drying.

[0027] Furthermore, the mass ratio of mercaptopropyltrimethoxysilane, anhydrous ethanol, and water is 1:5-10:1.

[0028] Furthermore, the pH adjustment specifically involves adding acetic acid to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4.

[0029] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0030] This invention uses bismuth powder, indium powder, and gallium powder as main raw materials and successfully prepares a low-melting-point metallic material through mechanical alloying. The material is coated with thiol groups on its surface, improving its compatibility and dispersibility in the resin. This material serves as a reinforcement, participating in photocuring crosslinking and significantly enhancing the mechanical strength of the 3D printing material. Simultaneously, during the heat treatment stage after cleaning the 3D printing material, due to the relatively low melting point of the metallic material, it melts and wets the surrounding cured resin network and ceramic particles, firmly bonding the entire structure together and further improving the mechanical strength of the 3D printing material.

[0031] The 3D printing material composition of this invention has good hydrophilicity. After 3D printing is completed, the excess material can be dissolved by quickly rinsing the 3D printed model with water, which can efficiently clean its surface. At the same time, by adding low melting point alloy powder to the composition, the mechanical strength of the 3D printing material is improved while ensuring water washing performance. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0033] Figure 1 The part blank produced by the composition corresponding to Example 8 in a 3D printing equipment;

[0034] Figure 2 This is a schematic diagram showing the state of the green part prepared in Example 8 after initial cleaning with a scraper and before water washing.

[0035] Figure 3 A schematic diagram showing the state of the green part prepared in Example 8 being washed and cleaned with water.

[0036] Figure 4 A schematic diagram showing the completely cleaned state of the green blank of the part prepared in Example 8;

[0037] In the picture: Figure 1 The interior of the frame is the raw blank, while the exterior of the frame is the uncured resin residue left after printing. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1; (1) Bismuth powder with a particle size of 10 μm, indium powder with a particle size of 10 μm, and gallium powder with a particle size of 10 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:30:22 and ground for 24 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:5:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 1 hour; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.4, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0040] (2) By weight, 20 parts of waterborne polyurethane acrylate resin, 5 parts of hydroxyethyl methacrylate, 1 part of glyceryl acrylate, 10 parts of polyethylene glycol diacrylate with a molecular weight of 400, 1 part of trimethylolpropane triacrylate, 5 parts of low melting point alloy powder, 5 parts of SiO2 with a particle size of 10 μm, 1 part of photoinitiator, and 0.1 parts of hydrophilic fumed silica are added to a mixer. At room temperature, the mixture is stirred at a speed of 500 r / min for 1 h and then allowed to stand for 2 h to obtain the composition. The waterborne polyurethane acrylate resin is W-2110 produced by ICL Company of the United Kingdom. The photoinitiator is 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and benzoin ether in a mass ratio of 0.5:1.

[0041] Example 2; (1) Bismuth powder with a particle size of 12 μm, indium powder with a particle size of 10 μm, and gallium powder with a particle size of 12 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:30:22 and ground for 24 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:5.7:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 1 hour; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.4, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0042] (2) By weight, 22 parts of waterborne polyurethane acrylate resin, 5 parts of hydroxyethyl methacrylate, 1 part of glyceryl acrylate, 10.7 parts of polyethylene glycol diacrylate with a molecular weight of 400, 2 parts of trimethylolpropane triacrylate, 5.7 parts of low melting point alloy powder, 6 parts of Al2O3 with a particle size of 10 μm, 1 part of photoinitiator, and 0.2 parts of hydrophilic fumed silica are added to a mixer. The mixture is stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The waterborne polyurethane acrylate resin is W-2200 produced by ICL Company of the United Kingdom. The photoinitiator is 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 2,4,6-trimethylbenzophenone in a mass ratio of 1:1.

[0043] Example 3; (1) Bismuth powder with a particle size of 15 μm, indium powder with a particle size of 15 μm, and gallium powder with a particle size of 10 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:31:23 and ground for 24 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:5:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 1 hour; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.5, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0044] (2) By weight, 25 parts of waterborne polyurethane acrylate resin, 6.4 parts of hydroxyethyl methacrylate, 3 parts of glyceryl acrylate, 13 parts of polyethylene glycol diacrylate with a molecular weight of 400, 3 parts of trimethylolpropane triacrylate, 7 parts of low melting point alloy powder, 4 parts of MgO with a particle size of 10 μm, 1 part of photoinitiator, and 0.35 parts of hydrophilic fumed silica are added to a mixer. At room temperature, the mixture is stirred at a speed of 500 r / min for 1 h and then allowed to stand for 2 h to obtain the composition. The waterborne polyurethane acrylate resin is W-2310 produced by ICL Company of the United Kingdom. The photoinitiator is 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 4-methylbenzophenone in a mass ratio of 1:1.

[0045] Example 4; (1) Bismuth powder with a particle size of 18 μm, indium powder with a particle size of 18 μm, and gallium powder with a particle size of 30 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:32:22 and ground for 30 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:7:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 1 hour; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.6, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0046] (2) By weight, 28 parts of waterborne polyurethane acrylic resin W-2310, 7 parts of hydroxyethyl methacrylate, 4 parts of glycerol acrylate, 12 parts of polyethylene glycol diacrylate with a molecular weight of 400, 4 parts of trimethylolpropane triacrylate, 7 parts of low melting point alloy powder, 5 parts of Sm2O3 with a particle size of 10 μm, 2 parts of photoinitiator, and 0.4 parts of hydrophilic fumed silica were added to a mixer. The mixture was stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The photoinitiator was 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 2,4-diethylthioxanthrone in a mass ratio of 2:1.

[0047] Example 5; (1) Bismuth powder with a particle size of 21 μm, indium powder with a particle size of 10 μm, and gallium powder with a particle size of 18 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:33:24 and ground for 30 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:7:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 2 hours; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.7, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0048] (2) By weight, 31 parts of waterborne polyurethane acrylic resin W-2200, 10 parts of hydroxyethyl methacrylate, 6 parts of glycerol acrylate, 15 parts of polyethylene glycol diacrylate with a molecular weight of 400, 5 parts of trimethylolpropane triacrylate, 10 parts of low melting point alloy powder, 5 parts of SiO2 with a particle size of 10 μm, 3 parts of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, and 0.6 parts of hydrophilic fumed silica were added to a mixer. The mixture was stirred for 1 hour at room temperature at a speed of 500 r / min and then allowed to stand for 2 hours to obtain the composition.

[0049] Example 6; (1) Bismuth powder with a particle size of 24 μm, indium powder with a particle size of 10 μm, and gallium powder with a particle size of 24 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:30:22 and ground for 30 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol, and water were mixed at a mass ratio of 1:5:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 2 hours; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.4, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0050] (2) By weight, 34 parts of waterborne polyurethane acrylic resin W-2110, 6 parts of hydroxyethyl methacrylate, 1 part of glyceryl acrylate, 11 parts of polyethylene glycol diacrylate with a molecular weight of 400, 1 part of trimethylolpropane triacrylate, 6 parts of low melting point alloy powder, 10 parts of Al2O3 with a particle size of 10 μm, 2 parts of photoinitiator, and 0.7 parts of hydrophilic fumed silica were added to a mixer. The mixture was stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The photoinitiator was 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and benzoin ether in a mass ratio of 0.5:1.

[0051] Example 7; (1) Bismuth powder with a particle size of 27 μm, indium powder with a particle size of 24 μm, and gallium powder with a particle size of 10 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:33:22 and ground for 40 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:6:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 2 hours; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.5, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0052] (2) By weight, 37 parts of waterborne polyurethane acrylic resin W-2200, 8 parts of hydroxyethyl methacrylate, 4 parts of glycerol acrylate, 12 parts of polyethylene glycol diacrylate with a molecular weight of 400, 5 parts of trimethylolpropane triacrylate, 7 parts of low melting point alloy powder, 10 parts of MgO with a particle size of 10 μm, 3 parts of photoinitiator, and 0.8 parts of hydrophilic fumed silica were added to a mixer. The mixture was stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The photoinitiator was 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 2,4,6-trimethylbenzophenone in a mass ratio of 1:1.

[0053] Example 8; (1) Bismuth powder with a particle size of 30 μm, indium powder with a particle size of 30 μm, and gallium powder with a particle size of 30 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:35:24 and ground for 40 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:10:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 2 hours; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.8, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0054] (2) By weight, 40 parts of waterborne polyurethane acrylic resin W-2310, 10 parts of hydroxyethyl methacrylate, 6 parts of glycerol acrylate, 10 parts of polyethylene glycol diacrylate with a molecular weight of 400, 2 parts of trimethylolpropane triacrylate, 7 parts of low melting point alloy powder, 9 parts of CaO with a particle size of 10 μm, 3 parts of photoinitiator, and 1 part of hydrophilic fumed silica were added to a mixer. The mixture was stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The photoinitiator was 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 2,4-diethylthioxanthrone in a mass ratio of 2:1.

[0055] Comparative Example 1; (1) Bismuth powder with a particle size of 30 μm, indium powder with a particle size of 30 μm, and gallium powder with a particle size of 30 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:35:24 and ground for 40 h under argon protection to obtain low melting point alloy powder;

[0056] (2) By weight, 40 parts of waterborne polyurethane acrylic resin W-2310, 10 parts of hydroxyethyl methacrylate, 6 parts of glycerol acrylate, 10 parts of polyethylene glycol diacrylate with a molecular weight of 400, 2 parts of trimethylolpropane triacrylate, 7 parts of low melting point alloy powder, 9 parts of CaO with a particle size of 10 μm, 3 parts of photoinitiator, and 1 part of hydrophilic fumed silica were added to a mixer. The mixture was stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The photoinitiator was 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 2,4-diethylthioxanthrone in a mass ratio of 2:1.

[0057] Comparative Example 2: By weight, 40 parts of waterborne polyurethane acrylic resin W-2310, 10 parts of hydroxyethyl methacrylate, 6 parts of glyceryl acrylate, 10 parts of polyethylene glycol diacrylate with a molecular weight of 400, 2 parts of trimethylolpropane triacrylate, 9 parts of CaO with a particle size of 10 μm, 3 parts of photoinitiator, and 1 part of hydrophilic fumed silica were added to a mixer. The mixture was stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The photoinitiator was 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 2,4-diethylthioxanthrone in a mass ratio of 2:1.

[0058] Comparative Example 3; (1) Bismuth powder with a particle size of 30 μm, indium powder with a particle size of 30 μm, and gallium powder with a particle size of 30 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:35:24 and ground for 40 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:10:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 2 hours; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.8, the immersion time was 30 minutes, and then filtered and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0059] (2) By weight, 40 parts of waterborne polyurethane acrylic resin W-2310, 10 parts of hydroxyethyl methacrylate, 6 parts of glycerol acrylate, 2 parts of trimethylolpropane triacrylate, 7 parts of low melting point alloy powder, 9 parts of CaO with a particle size of 10 μm, 3 parts of photoinitiator, and 1 part of hydrophilic fumed silica were added to a mixer. The mixture was stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The photoinitiator was 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 2,4-diethylthioxanthrone in a mass ratio of 2:1.

[0060] Comparative Example 4; (1) Bismuth powder with a particle size of 30 μm, indium powder with a particle size of 30 μm, and gallium powder with a particle size of 30 μm were loaded into a high-energy ball mill jar at a mass ratio of 60:35:24 and ground for 40 h under argon protection; mercaptopropyltrimethoxysilane, anhydrous ethanol and water were mixed at a mass ratio of 1:10:1, and acetic acid was added to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4, and the hydrolysis time was controlled to 2 hours; the alloy after grinding was immersed in the hydrolyzed silane coupling agent alcohol aqueous solution, the mass ratio of the alloy after grinding to mercaptopropyltrimethoxysilane was 1:0.8, the immersion time was 30 minutes, then filtered, and dried at 60°C for 12 h to obtain low melting point alloy powder;

[0061] (2) By weight, 40 parts of waterborne polyurethane acrylic resin W-2310, 10 parts of hydroxyethyl methacrylate, 6 parts of glycerol acrylate, 10 parts of polyethylene glycol diacrylate with a molecular weight of 400, 7 parts of low melting point alloy powder, 9 parts of CaO with a particle size of 10 μm, 3 parts of photoinitiator, and 1 part of hydrophilic fumed silica were added to a mixer. The mixture was stirred at 500 r / min for 1 h at room temperature and then allowed to stand for 2 h to obtain the composition. The photoinitiator was 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone and 2,4-diethylthioxanthrone in a mass ratio of 2:1.

[0062] Example of effect

[0063] The resin compositions prepared in Examples 1-8 and Comparative Examples 1-4 were used to print test samples using the HunterDLD light-curing printer from Zhejiang Flashforge 3D Co., Ltd. After the samples were washed and dried with tap water, they were placed in a 130℃ oven for 2 hours for post-treatment. The comprehensive properties of the sample samples, such as water cleanliness, tensile strength, elongation at break and hardness, are compared as shown in Table 1 below.

[0064] Tensile test: according to standard ISO527, INSTRON5966 electronic universal testing machine, tensile rate 50mm / min.

[0065] Sample water washing cleanliness test: visual inspection and touch. 10 points represents the best water washing cleanliness, and 1 point represents the worst.

[0066] Table 1

[0067]

[0068] As shown in Table 1, the cleanliness score of the present invention after water washing is ≥8 points (out of 10), indicating that the uncured resin can be removed efficiently and efficient water washing can be achieved. At the same time, the tensile strength is greater than 30MPa. Therefore, the present invention, through the combination of water-based resin and low-melting-point alloy, enables the 3D printing material to have both good water washability and mechanical strength.

[0069] This invention utilizes the physical swelling of polyethylene glycol diacrylate and the polyhydroxy hydration of glycerol acrylate to synergistically construct a high-strength yet water-destructible network, simultaneously improving the washability and strength of the composition. Using bismuth powder, indium powder, and gallium powder as main raw materials, this invention successfully prepares a low-melting-point metallic material through mechanical alloying. The surface is coated with thiol groups, improving its compatibility and dispersibility in resin. This material serves as a reinforcement, participating in photocuring crosslinking and significantly enhancing the mechanical strength of the 3D printing material. Furthermore, during the heat treatment stage after cleaning the 3D printing material, due to the relatively low melting point of the metallic material, it melts and wets the surrounding cured resin network and ceramic particles, firmly bonding the entire structure together and further improving the mechanical strength of the 3D printing material.

[0070] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A novel washable photocurable 3D printing material, characterized in that, By weight, it includes: 20-40 parts of photosensitive oligomer; 5-10 parts of hydroxyethyl methacrylate; 1-6 parts of glyceryl acrylate; 10-15 parts of polyethylene glycol diacrylate; 1-5 parts of trimethylolpropane triacrylate; 5-10 parts of low melting point alloy powder; 5-10 parts of ceramic powder; 1-3 parts of photoinitiator; 0.1-1 part of hydrophilic fumed silica; The preparation method of the low melting point alloy powder is as follows: bismuth powder, indium powder, and gallium powder are loaded into a high-energy ball mill jar, with a mass ratio of bismuth powder, indium powder, and gallium powder of 60:30-35:22-25. Under argon protection, the powder is ground for 20-40 hours. Mercaptopropyltrimethoxysilane, anhydrous ethanol, and water are mixed, the pH is adjusted, and the hydrolysis time is controlled to be 1-2 hours. The ground alloy is then immersed in a hydrolyzed silane coupling agent alcohol aqueous solution for 30 minutes, followed by filtration and drying to obtain the final product. The photosensitive oligomer is one or a combination of one or more of waterborne polyurethane acrylic resin, waterborne polyester acrylic resin, and waterborne epoxy acrylic resin.

2. The novel washable photocurable 3D printing material according to claim 1, characterized in that, The photoinitiator is at least one selected from benzoin ether, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, isopropylthioxanthonone, 2-chlorothioxanthonone, 2,4-diethylthioxanthonone, and 2-ethylanthraquinone.

3. The novel washable photocurable 3D printing material according to claim 1, characterized in that, The polyethylene glycol diacrylate has a molecular weight of 400.

4. The novel washable photocurable 3D printing material according to claim 1, characterized in that, The ceramic powder is one or more of SiO2, Al2O3, MgO, CaO, Sm2O3, and ZrO2.

5. The novel washable photocurable 3D printing material according to claim 1, characterized in that, The bismuth powder, indium powder, and gallium powder have a particle size of 10-30 μm.

6. The novel washable photocurable 3D printing material according to claim 1, characterized in that, The mass ratio of mercaptopropyltrimethoxysilane, anhydrous ethanol, and water is 1:5-10:

1.

7. The novel washable photocurable 3D printing material according to claim 1, characterized in that, The pH adjustment specifically involves adding acetic acid to adjust the pH of the mercaptopropyltrimethoxysilane alcohol aqueous solution to 4.

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