3D printing photosensitive resin material based on epoxy resin and preparation method thereof

Abstract

The invention discloses a 3D printing photosensitive resin material based on epoxy resin and a preparation method of the 3D printing photosensitive resin material, and relates to the technical field of 3D printing. The preparation method comprises the following steps: sequentially adding 1, 4-epoxy cyclohexyl methacrylate, 2-hydroxyethyl acrylate, tetraethylene glycol diacrylate, a photoinitiator 819, bis (4-(diphenyl sulfonium) phenyl) thioether-bis hexafluoroantimonate, modified nano titanium dioxide, a photosensitizer and organic silicon epoxy resin into a reaction container, carrying out ultrasonic dispersion, uniformly mixing, and carrying out cryopreservation to obtain the 3D printing photosensitive resin material. The modified nano titanium dioxide is prepared by coating the modified nano titanium dioxide with 2-isopropyl thioxanthone; the photosensitizer is a thioxanthone derivative. The 3D printing photosensitive resin material prepared by the preparation method disclosed by the invention has excellent mechanical properties and low volume shrinkage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing, in particular to a 3D printing photosensitive resin material based on epoxy resin and a preparation method thereof. BACKGROUND

[0002] In the field of 3D printing technology, photosensitive resin has been widely used in aerospace, medical devices, precision manufacturing and other fields due to its fast curing speed and high forming precision. However, the existing photosensitive resin material still has many technical bottlenecks in the curing system, mechanical properties and shrinkage control, which limits its application in high requirement scenarios.

[0003] From the perspective of the curing system, traditional photosensitive resin relies on the matching of a single photoinitiator and resin matrix, and has the problems of insufficient curing depth and uneven crosslinking density. Some systems have strong selectivity to the wavelength of the light source, and are prone to incomplete curing under ultraviolet or visible light irradiation, resulting in rough surface of the printed part and internal pores, affecting the stability of the final product.

[0004] In terms of mechanical properties, the existing photosensitive resin printed parts often face the dilemma of balancing rigidity and toughness. Materials with too high rigidity are prone to brittle fracture under stress, while materials with high toughness may have problems such as excessive deformation and poor dimensional stability. This contradiction is due to the unreasonable design of the molecular chain structure of the resin matrix and the insufficient interfacial compatibility between inorganic fillers and organic phases, which limits the improvement of the mechanical properties of the composite material.

[0005] Shrinkage is a key factor affecting the precision of 3D printing. During the curing process of traditional photosensitive resin, the volume shrinks due to the transition of molecular chains from disordered state to ordered crosslinked structure, resulting in warping, cracking or dimensional deviation of the printed part. Especially in the printing of large and complex structures, the accumulation of shrinkage stress can seriously reduce the forming precision and increase the difficulty of post-processing. At present, the method of adding inorganic nano fillers or optimizing the proportion of crosslinking agent to reduce shrinkage often has the side effects of decreasing the curing speed or weakening the mechanical properties, making it difficult to achieve a synergistic improvement in comprehensive performance.

[0006] Therefore, it is an important task in the field of 3D printing technology to develop a photosensitive resin material with efficient curing system, excellent mechanical properties and low shrinkage. SUMMARY

[0007] The present application relates to the technical field of 3D printing, in particular to a 3D printing photosensitive resin material based on epoxy resin and a preparation method thereof.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A preparation method of an epoxy resin-based 3D printing photosensitive resin material, comprising the following steps: S1: adding isopropyl titanate and triethanolamine into deionized water, stirring uniformly, adjusting pH to 9.5-9.6, heating to 100-105 DEG C and reacting for 24 h, further heating to 140-145 DEG C and aging for 8-8.5 h, filtering, washing the product with ethanol, vacuum drying at 120-125 DEG C for 4-4.5 h, calcining at 500-505 DEG C for 3-3.5 h, and obtaining nano titanium dioxide; Further, in the preparation process of the nano titanium dioxide, the volume ratio of isopropyl titanate to triethanolamine is (3.9-4):3.5; S2: ultrasonic dispersion of the nano titanium dioxide in ethanol, adding 2-isopropyl thioxanthone ethanol solution, stirring at room temperature until the solution is completely evaporated, and obtaining modified nano titanium dioxide; Further, in the preparation process of the modified nano titanium dioxide, the mass ratio of nano titanium dioxide to 2-isopropyl thioxanthone is 1:(0.5-0.75); S3: adding 2-bromo-4-methoxy-benzoic acid, 3-methoxy thiophenol, potassium carbonate, copper powder and cuprous oxide into 2-ethoxy ethanol, heating to 130-135 DEG C and reacting for 16-16.5 h, cooling to room temperature, adding deionized water into the reaction mixture, adding activated carbon, filtering the mixture through diatomite, adjusting the pH of the filtrate to 5 with dilute hydrochloric acid, filtering, collecting the precipitate, adding the precipitate into 5% sodium carbonate solution, stirring to dissolve, filtering the solution through diatomite, adjusting the pH of the filtrate to 5 with dilute hydrochloric acid again, repeating the precipitation-filtration-dissolution-filtration-acidification steps, and purifying to obtain 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid; Further, in the preparation process of the 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid, the molar ratio of 2-bromo-4-methoxy-benzoic acid to 3-methoxy thiophenol to potassium carbonate to copper powder to cuprous oxide is (8.3-9.2):(10-11.9):(10-12.1):1:0.5; S4: adding 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid and oxalyl chloride into dichloromethane, stirring uniformly, adding N,N-dimethylformamide, reacting for 1-1.5 h, removing the solvent under reduced pressure, dissolving the residue in dichloromethane, adding aluminum chloride under ice bath condition, stirring and reacting for 12-12.5 h, quenching with deionized water, extracting with dichloromethane, washing with saturated sodium bicarbonate solution, drying, removing the solution under reduced pressure, and purifying to obtain a photosensitizer; Further, in the preparation process of the photosensitizer, the molar ratio of 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid, oxalyl chloride and aluminum chloride is (1-1.1):(1.2-1.3):(1.2-1.3); S5: 4-vinyl-1-cyclohexene-1,2-epoxy, toluene, platinum gold catalyst, ethanol are added into a reaction container, heated to 80-85 DEG C, stirred uniformly, 2,4,6,8-tetramethylcyclotetrasiloxane toluene mixture is added, and the reaction is kept at 80-85 DEG C for 1-1.5 h, and vacuum rotary evaporation is carried out to obtain a silicone epoxy resin; Further, in the preparation process of the silicone epoxy resin, the molar ratio of 4-vinyl-1-cyclohexene-1,2-epoxy and 2,4,6,8-tetramethylcyclotetrasiloxane is 4:(1-1.2); the addition amount of platinum gold catalyst is 0.0015-0.002wt% of the mass of 4-vinyl-1-cyclohexene-1,2-epoxy; S6: 3,4-epoxycyclohexyl methacrylate, 2-hydroxyethyl acrylate, tetraethylene glycol diacrylate, photoinitiator 819, bis(4-(diphenyl sulfonium)phenyl) sulfide-bishexafluoroantimonate, modified nano titanium dioxide, photosensitizer, silicone epoxy resin are sequentially added into a reaction container, ultrasonic dispersion, mixing uniformly, freezing preservation, to obtain a 3D printing photosensitive resin material.

[0009] Further, in the preparation process of the 3D printing photosensitive resin material, the components include 3,4-epoxycyclohexyl methacrylate 6-8 parts, 2-hydroxyethyl acrylate 2.2-3.4 parts, tetraethylene glycol diacrylate 0.02-0.04 parts, photoinitiator 819 0.13-0.15 parts, bis(4-(diphenyl sulfonium)phenyl) sulfide-bishexafluoroantimonate 0.667-0.778 parts, modified nano titanium dioxide 1.6-2.4 parts, photosensitizer 0.078-0.089 parts, and silicone epoxy resin 1-3 parts.

[0010] Compared with the prior art, the beneficial effects of the present application are: 1, the present application is a hybrid monomer containing epoxy and acrylate groups, which is constructed by the wavelength selective photoinitiating system of the unique wavelength selection performance of the self-made 3,6-dimethoxythioxanthone, combined with the mechanism of double curing (acrylate radical polymerization, epoxy group cationic polymerization) and sequential curing (405nm, 365nm), and finally prepared 3D printing photosensitive resin with excellent mechanical properties and shrinkage properties.

[0011] 2,3,6-dimethoxythioxanthone can enhance the absorption efficiency of photoacid generator bis(4-(diphenyl sulfonio)phenyl) sulfide-bishexafluoroantimonate at 365 nm, synergize with 2-isopropylthioxanthone 365 nm absorption enhancement, improve wavelength selectivity, avoid cross reaction. 405 nm violet light activates free radical photoinitiator, triggers free radical polymerization of acrylate, at the same time, as a diluent for the cured epoxy-containing monomer, reduces free radical polymerization shrinkage, and further uniformly disperses in the matrix; under 365 nm ultraviolet light irradiation, activate photoacid generator and photosensitizer, start cationic polymerization of epoxy groups, the formed acrylate network limits the movement of epoxy monomer, inhibits the volume relaxation during epoxy polymerization, thereby reducing post-curing shrinkage, the four epoxy groups in the silicone epoxy resin structure build a rigid network during curing, limiting the movement of polymer chains, reducing curing shrinkage. (3,4-epoxycyclohexyl) methacrylate as a key hybrid monomer, covalently links the epoxy and acrylate networks, reducing the delamination phenomenon at the soft / hard material interface, and endowing the 3D printing photosensitive resin with excellent mechanical properties. DETAILED DESCRIPTION

[0012] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0013] In the following examples, nano titanium dioxide was prepared as follows: 3.9 mL isopropyl titanate, 3.5 mL triethanolamine were added to deionized water, stirred uniformly, adjusted to pH 9.5, heated to 100°C for 24 h, further heated to 140°C for 8 h, filtered, the product was washed with ethanol, vacuum dried at 120°C for 4 h, calcined at 500°C for 3 h to obtain nano titanium dioxide; The photosensitizer was prepared as follows: 8.9 mmol 2-bromo-4-methoxy-benzoic acid, 10 mmol 3-methoxybenzenethiol, 10 mmol potassium carbonate, 1 mmol copper powder, 0.5 mmol cuprous oxide were added to 30 mL 2-ethoxyethanol, heated to 130°C for 16 h, cooled to room temperature, deionized water was added to the reaction mixture, activated carbon was added, the mixture was filtered through diatomite, the filtrate was adjusted to pH 5 with dilute hydrochloric acid, filtered, the precipitate was collected, the precipitate was added to a 5% sodium carbonate solution, stirred to dissolve, the solution was filtered through diatomite, the filtrate was adjusted to pH 5 with dilute hydrochloric acid again, the precipitation-filtration-dissolution-filtration-acidification steps were repeated, and the product was purified to obtain 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid. Add 10 mmol of 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid, 12 mmol of oxalyl chloride into dichloromethane, stir uniformly, add 50 mL of N,N-dimethylformamide, react for 1 h, remove the solvent under reduced pressure, dissolve the residue in dichloromethane, add 12 mmol of aluminum chloride under ice bath conditions, stir for 12 h, quench with deionized water, extract with dichloromethane, wash with saturated sodium bicarbonate solution, dry, remove the solution under reduced pressure, purify, and obtain the photosensitizer.

[0014] The silicone epoxy resin is prepared as follows: Add 0.4 mol of 4-vinyl-1-cyclohexene-1,2-epoxide, 50 mL of toluene, 0.0015 wt% of platinum gold catalyst, and 4 g of ethanol into a reaction vessel, heat to 80°C, stir uniformly, add 0.1 mmol of a toluene mixture of 2,4,6,8-tetramethylcyclotetrasiloxane, and react for 1 h at 80°C under vacuum rotary evaporation to obtain the silicone epoxy resin.

[0015] Example 1: A preparation method of an epoxy resin-based 3D printing photosensitive resin material: S1: ultrasonically disperse 1 g of nano-titanium dioxide in ethanol, add an ethanol solution containing 0.5 g of 2-isopropylthioxanthone, stir at room temperature until the solution is completely evaporated, and obtain modified nano-titanium dioxide; S2: sequentially add 8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of a photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonio)phenyl) sulfide-bishexafluoroantimonate, 1.6 parts of modified nano-titanium dioxide, 0.078 parts of a photosensitizer, and 1 part of a silicone epoxy resin into a reaction vessel, ultrasonically disperse, mix uniformly, and freeze to obtain the 3D printing photosensitive resin material.

[0016] Example 2: A preparation method of an epoxy resin-based 3D printing photosensitive resin material: S1: ultrasonically disperse 1 g of nano-titanium dioxide in ethanol, add an ethanol solution containing 0.75 g of 2-isopropylthioxanthone, stir at room temperature until the solution is completely evaporated, and obtain modified nano-titanium dioxide; S2: sequentially add 8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of a photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonio)phenyl) sulfide-bishexafluoroantimonate, 1.6 parts of modified nano-titanium dioxide, 0.078 parts of a photosensitizer, and 1 part of a silicone epoxy resin into a reaction vessel, ultrasonically disperse, mix uniformly, and freeze to obtain the 3D printing photosensitive resin material.

[0017] Embodiment 3: A method for preparing an epoxy resin-based 3D printing photosensitive resin material: S1: ultrasonic dispersion of 1 g of nano-titanium dioxide in ethanol, addition of an ethanol solution containing 0.75 g of 2-isopropylthioxanthone, stirring at room temperature until the solution completely evaporates, to obtain modified nano-titanium dioxide; S2: 8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonium)phenyl) sulfide-bishexafluoroantimonate, 2 parts of modified nano-titanium dioxide, 0.083 parts of photosensitizer, 1 part of silicone epoxy resin are sequentially added to a reaction container, ultrasonic dispersion, uniform mixing, frozen preservation, to obtain a 3D printing photosensitive resin material.

[0018] Embodiment 4: A method for preparing an epoxy resin-based 3D printing photosensitive resin material: S1: ultrasonic dispersion of 1 g of nano-titanium dioxide in ethanol, addition of an ethanol solution containing 0.75 g of 2-isopropylthioxanthone, stirring at room temperature until the solution completely evaporates, to obtain modified nano-titanium dioxide; S2: 8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonium)phenyl) sulfide-bishexafluoroantimonate, 2.4 parts of modified nano-titanium dioxide, 0.089 parts of photosensitizer, 1 part of silicone epoxy resin are sequentially added to a reaction container, ultrasonic dispersion, uniform mixing, frozen preservation, to obtain a 3D printing photosensitive resin material.

[0019] Embodiment 5: A method for preparing an epoxy resin-based 3D printing photosensitive resin material: S1: ultrasonic dispersion of 1 g of nano-titanium dioxide in ethanol, addition of an ethanol solution containing 0.75 g of 2-isopropylthioxanthone, stirring at room temperature until the solution completely evaporates, to obtain modified nano-titanium dioxide; S2: 8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonium)phenyl) sulfide-bishexafluoroantimonate, 2.4 parts of modified nano-titanium dioxide, 0.089 parts of photosensitizer, 2 parts of silicone epoxy resin are sequentially added to a reaction container, ultrasonic dispersion, uniform mixing, frozen preservation, to obtain a 3D printing photosensitive resin material.

[0020] Embodiment 6: A method for preparing an epoxy resin-based 3D printing photosensitive resin material: S1: ultrasonic dispersion of 1 g of nano-titanium dioxide in ethanol, addition of an ethanol solution containing 0.75 g of 2-isopropylthioxanthone, stirring at room temperature until the solution completely evaporates, to obtain modified nano-titanium dioxide; S2: 8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of a photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonio)phenyl) sulfide-bishexafluoroantimonate, 2.4 parts of modified nano titanium dioxide, 0.089 parts of a photosensitizer, 3 parts of a silicone epoxy resin were sequentially added to a reaction vessel, ultrasonic dispersion, mixed uniformly, frozen preservation, to obtain a 3D printing photosensitive resin material.

[0021] Comparative Example 1: A preparation method of an epoxy resin-based 3D printing photosensitive resin material: S1: 1 g of nano titanium dioxide was ultrasonically dispersed in ethanol, and an ethanol solution containing 0.25 g of 2-isopropylthioxanthone was added, stirred at room temperature until the solution was completely evaporated, to obtain modified nano titanium dioxide; S2: 8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of a photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonio)phenyl) sulfide-bishexafluoroantimonate, 1.6 parts of modified nano titanium dioxide, 0.078 parts of a photosensitizer, 1 part of a silicone epoxy resin were sequentially added to a reaction vessel, ultrasonic dispersion, mixed uniformly, frozen preservation, to obtain a 3D printing photosensitive resin material.

[0022] Comparative Example 2: A preparation method of an epoxy resin-based 3D printing photosensitive resin material: S1: 1 g of nano titanium dioxide was ultrasonically dispersed in ethanol, and an ethanol solution containing 1 g of 2-isopropylthioxanthone was added, stirred at room temperature until the solution was completely evaporated, to obtain modified nano titanium dioxide; S2: 8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of a photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonio)phenyl) sulfide-bishexafluoroantimonate, 1.6 parts of modified nano titanium dioxide, 0.078 parts of a photosensitizer, 1 part of a silicone epoxy resin were sequentially added to a reaction vessel, ultrasonic dispersion, mixed uniformly, frozen preservation, to obtain a 3D printing photosensitive resin material.

[0023] Comparative Example 3: A preparation method of an epoxy resin-based 3D printing photosensitive resin material: S1: 1 g of nano titanium dioxide was ultrasonically dispersed in ethanol, and an ethanol solution containing 0.5 g of 2-isopropylthioxanthone was added, stirred at room temperature until the solution was completely evaporated, to obtain modified nano titanium dioxide; S2: 8 parts of glycidyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonium)phenyl) sulfide-bis-hexafluoroantimonate, 1.6 parts of modified nano-titanium dioxide, 0.078 parts of photosensitizer, 1 part of silicone epoxy resin were sequentially added into a reaction vessel, ultrasonic dispersion, mixed uniformly, frozen preservation, to obtain a 3D printing photosensitive resin material.

[0024] Preparation method of a 3D printing photosensitive resin material based on epoxy resin: S1: 1g of nano-titanium dioxide was ultrasonically dispersed in ethanol, and an ethanol solution containing 0.25g of 2-isopropylthioxanthone was added, and stirred at room temperature until the solution was completely evaporated to obtain modified nano-titanium dioxide; S2: 8 parts of glycidyl methacrylate, 2.2 parts of 2-hydroxyethyl acrylate, 0.02 parts of tetraethylene glycol diacrylate, 0.13 parts of photoinitiator 819, 0.667 parts of bis(4-(diphenyl sulfonium)phenyl) sulfide-bis-hexafluoroantimonate, 1.6 parts of modified nano-titanium dioxide, 0.078 parts of 2-isopropylthioxanthone, 1 part of silicone epoxy resin were sequentially added into a reaction vessel, ultrasonic dispersion, mixed uniformly, frozen preservation, to obtain a 3D printing photosensitive resin material.

[0025] Experiment: The 3D printing photosensitive resin materials prepared in the above examples and comparative examples were placed and allowed to naturally warm up to room temperature, and then 3D printing was performed, first 405nm ultraviolet light printing and curing, and then placed in 365nm ultraviolet light for curing, to obtain test samples.

[0026] Tensile strength: tested by an impact testing machine, and the size of the test bar was also 100mmx10mmx5mm; Curing shrinkage: a cube with a side length of 10cmx10cmx10cm was designed, and the actual printed cube had a side length of LcmxLcmxLcm, and the shrinkage was calculated as 10-L / 10x100%.

[0027] The experimental data are shown in Table 1 below.

[0028] Table 1: Performance test data table of 3D printing photosensitive resin material

[0029] Conclusion: The 3D printing photosensitive resin material prepared by the present application has excellent mechanical properties and low volume shrinkage.

[0030] In Comparative Example 1, the coating amount of 2-isopropylthioxanthone on the surface of nano-titanium dioxide is too low, which reduces the curing efficiency and leads to reduced mechanical properties and anti-shrinkage performance.

[0031] The amount of 2-isopropylthioxanthone coated on the surface of nano-titanium dioxide in Comparative Example 2 is too high, which hinders the photocatalytic activity of nano-titanium dioxide itself, resulting in a slight decrease in performance.

[0032] In Comparative Example 3, glycidyl methacrylate is used to replace (3,4-epoxycyclohexyl) methacrylate. Since the cationic polymerization activity of glycidyl ether group is lower than that of cycloaliphatic epoxy group, it is easy to cure incompletely under the same time, and a longer curing time is needed, which reduces the efficiency. At the same time, it is easy to be affected by 405 nm violet light, and premature curing leads to the performance of shrinkage being affected. The acrylate and epoxy groups in glycidyl methacrylate are separated by a long aliphatic chain, and the tendency of phase separation increases, the interface is easy to delaminate, which leads to the weakening of the interface bonding and the reduction of mechanical properties.

[0033] In Comparative Example 4, 2-isopropylthioxanthone is used to replace the photosensitizer prepared in the application, which leads to a decrease in selectivity for 365 nm wavelength. The enhancement of 2-isopropylthioxanthone for 365 nm wavelength is far lower than that of 3,6-dimethoxythioxanthone photosensitizer prepared in the application.

[0034] It is apparent for those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the present application being defined by the appended claims rather than the foregoing description, and it is intended that all changes that come within the meaning and range of equivalency of the claims are embraced therein.

Claims

1. A method for preparing a 3D printing photosensitive resin material based on epoxy resin, characterized in that: The following steps are involved: 3,4-Epoxycyclohexyl methacrylate, 2-hydroxyethyl acrylate, tetraethylene glycol diacrylate, photoinitiator 819, bis(4-(diphenylsulfonium)phenyl) sulfide-bishexafluoroantimonate, modified nano-titanium dioxide, photosensitizer, and silicone epoxy resin were sequentially added into a reaction container, ultrasonically dispersed, mixed evenly, and frozen to obtain a 3D printing photosensitive resin material; The modified nano titanium dioxide is prepared by coating modified nano titanium dioxide with 2-isopropylthioxanthone; The photosensitizer is a thioxanthone derivative.

2. The method for preparing a 3D printing photosensitive resin material based on epoxy resin according to claim 1, characterized in that: The components of the 3D printing photosensitive resin material, calculated by mass, include 6-8 parts of 3,4-epoxycyclohexyl methacrylate, 2.2-3.4 parts of 2-hydroxyethyl acrylate, 0.02-0.04 parts of tetraethylene glycol diacrylate, 0.13-0.15 parts of photoinitiator 819, 0.667-0.778 parts of bis(4-(diphenylsulfonium)phenyl)sulfide-bishexafluoroantimonate, 1.6-2.4 parts of modified nano-titanium dioxide, 0.078-0.089 parts of photosensitizer, and 1-3 parts of silicone epoxy resin.

3. The method for preparing a 3D printing photosensitive resin material based on epoxy resin according to claim 1, characterized in that: The preparation method of the photosensitizer comprises the following steps: step (1): adding 2-bromo-4-methoxy-benzoic acid, 3-methoxythiophenol, potassium carbonate, copper powder, and cuprous oxide to 2-ethoxyethanol, heating to 130-135° C. for reaction for 16-16.5 hours, cooling to room temperature, adding deionized water to the reaction mixture, and purifying to obtain 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid; Step (2): Add 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid and oxalyl chloride to dichloromethane, stir evenly, add N,N-dimethylformamide, react for 1-1.5 hours, remove the solvent under reduced pressure, add dichloromethane to dissolve the residue, add aluminum chloride under ice bath conditions, stir the reaction for 12-12.5 hours, add deionized water to quench, extract with dichloromethane, wash with saturated sodium bicarbonate solution, dry, remove the solvent under reduced pressure, and purify to obtain a photosensitizer.

4. The method for preparing a 3D printing photosensitive resin material based on epoxy resin according to claim 3, characterized in that: In the preparation process of 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid, the molar ratio of 2-bromo-4-methoxy-benzoic acid: 3-methoxybenzenethiol: potassium carbonate: copper powder: cuprous oxide is (8.3-9.2): (10-11.9): (10-12.1): 1: 0.

5.

5. The method for preparing a 3D printing photosensitive resin material based on epoxy resin according to claim 3, characterized in that: During the preparation of the photosensitizer, the molar ratio of 4-methoxy-2-[(3-methoxyphenyl)thio]benzoic acid:oxalyl chloride:aluminum trichloride is (1-1.1):(1.2-1.3):(1.2-1.3).

6. The method for preparing a 3D printing photosensitive resin material based on epoxy resin according to claim 1, characterized in that: The preparation method of the modified nano-titanium dioxide comprises the following steps: adding isopropyl titanate and triethanolamine to deionized water, stirring evenly, adjusting the pH to 9.5-9.6, heating to 100-105° C. for reaction for 24 hours, further heating to 140-145° C. for aging for 8-8.5 hours, filtering, washing the product with ethanol, vacuum drying at 120-125° C. for 4-4.5 hours, and calcining at 500-505° C. for 3-3.5 hours to obtain nano-titanium dioxide; The nano-titanium dioxide is ultrasonically dispersed in ethanol, an ethanol solution of 2-isopropylthioxanthone is added, and the mixture is stirred at room temperature until the solution is completely evaporated to obtain modified nano-titanium dioxide.

7. The method for preparing a 3D printing photosensitive resin material based on epoxy resin according to claim 6, characterized in that: During the preparation of nano-titanium dioxide, the volume ratio of isopropyl titanate: triethanolamine is (3.9-4):3.5; During the preparation of the modified nano-titanium dioxide, the mass ratio of nano-titanium dioxide to 2-isopropylthioxanthone is 1:(0.5-0.75).

8. The method for preparing a 3D printing photosensitive resin material based on epoxy resin according to claim 1, characterized in that: The preparation method of the organosilicon epoxy resin comprises the following steps: adding 4-vinyl-1-cyclohexene-1,2-epoxy, toluene, a platinum catalyst, and ethanol into a reaction vessel, heating to 80-85° C., stirring evenly, adding a toluene mixture of 2,4,6,8-tetramethylcyclotetrasiloxane, keeping the temperature for reaction for 1-1.5 hours, and vacuum rotary evaporation at 80-85° C. to obtain the organosilicon epoxy resin.

9. The method for preparing a 3D printing photosensitive resin material based on epoxy resin according to claim 8, characterized in that: During the preparation of the silicone epoxy resin, the molar ratio of 4-vinyl-1-cyclohexene-1,2-epoxy:2,4,6,8-tetramethylcyclotetrasiloxane is 4:(1-1.2); and the amount of platinum catalyst added is 0.0015-0.002 wt% of the mass of 4-vinyl-1-cyclohexene-1,2-epoxy.

10. A 3D printing photosensitive resin material prepared according to the method for preparing a 3D printing photosensitive resin material based on epoxy resin according to any one of claims 1 to 9.

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