Photocuring 3D printing material with excellent mechanical property and preparation method thereof

Abstract

The invention discloses a photocuring 3D printing material with excellent mechanical properties and a preparation method thereof. The 3D printing material disclosed by the invention is prepared by adopting an acrylate / epoxy resin hybrid light-cured resin system and adopting a light-heat dual-curing method. The hybrid light-cured resin system comprises 20-40 parts of polyurethane (methyl) acrylate containing dynamic reversible urea bonds, 20-40 parts of acrylate light-cured monomers, 0.1-5 parts of a photoinitiator and 10-80 parts of epoxy resin. The resin system is formed through photo-thermal two-step curing, and in the photo-curing stage, rapid and accurate 3D printing is achieved through free radical polymerization of an acrylate part; and in the subsequent thermocuring stage, the dynamic reversible urea bonds are dissociated, the curing process of the epoxy resin is efficiently triggered, the mechanical property of the printed piece is remarkably improved, and finally the 3D printed piece with the excellent mechanical property is obtained.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a photopolymerizable 3D printing material with excellent mechanical properties and its preparation method. Background Technology

[0002] Photopolymer 3D printing technology uses UV-cured monomers or oligomers to cure under ultraviolet light for printing, and it is one of the 3D printing technologies with the highest printing precision. Currently, the resins used for photopolymer 3D printing are mainly acrylate-based, epoxy-based, and acrylate / epoxy hybrid resins. Hybrid resins, combining the high curing rate of the acrylate portion with the low shrinkage and oxygen-free inhibition effect of the epoxy portion, have been widely used in model making. However, a key limitation of photopolymer resins is that their degree of curing is usually lower than that of thermosetting materials, resulting in mechanical properties that often fail to meet the requirements of structural applications.

[0003] To overcome mechanical property limitations, a photothermal dual-curing method has been developed: the first step involves photocuring the acrylate portion to achieve 3D printing, and the second step involves thermal curing the epoxy resin to further enhance the mechanical properties of the printed object. However, this strategy faces two major challenges in resin preparation and printing. The first challenge lies in the stability of the thermally curing component during preparation and photocuring. Commonly used amine or anhydride epoxy resin curing agents can cause slow curing of the epoxy component at room temperature or during photopolymerization, thus affecting the storage and handling stability of the printing resin. While latent curing agents can improve stability, they suffer from problems such as difficulty in dispersion and impaired light transmittance. The other challenge is the risk of internal stress and cracking during thermal curing. The inherent curing shrinkage during thermal curing generates significant internal stress, which may lead to cracking of the printed part. Furthermore, research shows that mono-network structures can provide better thermal stability and mechanical properties for 3D printed components compared to interpenetrating polymer network structures. Summary of the Invention

[0004] The purpose of this invention is to provide a photocurable 3D printing material with excellent mechanical properties and its preparation method. This invention innovatively designs a polyurethane acrylate containing dynamically reversible urea bonds and mixes it with a photocurable monomer and epoxy resin to construct a novel hybrid photocurable resin system. During the photocuring stage, the polyurethane acrylate component achieves rapid and precise 3D printing through free radical polymerization. In the subsequent thermocuring stage, the dynamically reversible urea bonds dissociate, efficiently triggering the curing process of the epoxy resin and significantly improving the final mechanical properties of the printed part.

[0005] The present invention provides a hybrid photocurable resin system for preparing photocurable 3D printing materials with excellent mechanical properties. The raw materials include the following components in parts by weight: 20-40 parts of polyurethane (meth)acrylate containing dynamic reversible urea bonds, 20-40 parts of photocurable monomer, 0.1-5 parts of photoinitiator, and 10-80 parts of epoxy resin.

[0006] Preferably, the hybrid photocurable resin system comprises the following components in parts by weight: 25-35 parts of polyurethane (meth)acrylate containing dynamic reversible urea bonds, 20-35 parts of photocurable monomer, 1-2 parts of photoinitiator, and 30-55 parts of epoxy resin.

[0007] In this invention, the polyurethane (meth)acrylate containing dynamic reversible urea bonds is first obtained by reacting diisocyanate with an alcohol or amine containing pyrrolidine or piperazine groups or a hydroxyl-terminated polyol to obtain an isocyanate-terminated prepolymer, and then reacting it with a hydroxyl-containing (meth)acrylate to obtain the polyurethane (meth)acrylate containing dynamic reversible urea bonds.

[0008] According to an embodiment of the present invention, the diisocyanate is selected from at least one of toluene diisocyanate, hydrogenated phenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, phenylmethane diisocyanate, etc.

[0009] According to an embodiment of the present invention, the pyrrolidine-containing alcohol or amine is selected from at least one of 3-hydroxypyrrolidine, pyrrolidine-2-methanol, L-hydroxyproline, etc.

[0010] According to an embodiment of the present invention, the alcohol or amine containing the piperazine group is selected from at least one of N-aminoethylpiperazine and N-hydroxyethylpiperazine.

[0011] According to an embodiment of the present invention, the hydroxyl-terminated polyol is selected from at least one of polyether polyols, polyester polyols, and polyolefin polyols.

[0012] Furthermore, the polyether polyol is selected from at least one of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran glycol.

[0013] Furthermore, the polyester polyol is selected from at least one of polycaprolactone diol, polylactic acid diol, polyethylene adipate diol, and polybutylene adipate diol.

[0014] Furthermore, the polyolefin polyol is selected from polybutadiene glycol.

[0015] Furthermore, the number-average molecular weight of the hydroxyl-terminated polyol is 200–10000 g / mol.

[0016] According to an embodiment of the present invention, the hydroxyl-containing (meth)acrylate is selected from at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and hydroxybutyl methacrylate.

[0017] Furthermore, the polyurethane (meth)acrylate containing dynamically reversible urea bonds can be prepared by a method including the following steps:

[0018] S1: In the presence of a catalyst, diisocyanate is mixed with an alcohol or amine containing pyrrolidine or piperazine groups, a hydroxyl-terminated polyol, and an organic solvent to undergo a stepwise addition polymerization reaction to obtain an isocyanate-terminated prepolymer.

[0019] S2: The isocyanate-terminated prepolymer prepared above is reacted with hydroxyl-containing (meth)acrylate, and a polymerization inhibitor is added during the reaction to obtain a polyurethane (meth)acrylate solution. After removing the solvent by rotary evaporation, a polyurethane (meth)acrylate with dynamic reversible urea bonds is obtained.

[0020] According to an embodiment of the present invention, the catalyst is a tertiary amine catalyst or an organometallic catalyst;

[0021] Furthermore, the tertiary amine is selected from at least one of the following: triethylenediamine, bis(dimethylaminoethyl) ether, and the organometallic catalyst is selected from at least one of the following: stannous octoate, n-butyltin laurate.

[0022] According to an embodiment of the present invention, the organic solvent is selected from at least one of acetone, tetrahydrofuran, dimethyl sulfoxide, dimethylformamide, and dimethylacetamide.

[0023] According to an embodiment of the present invention, the polymerization inhibitor is selected from at least one of hydroquinone and p-methoxyphenol.

[0024] According to an embodiment of the present invention, in step S1, the amount of catalyst used is 200–600 ppm. The reaction temperature of the polymerization reaction is 50–100°C, and the reaction time is 1–12 h.

[0025] According to an embodiment of the present invention, in step S2, the amount of the polymerization inhibitor is 50 to 1000 ppm; the reaction temperature is 50 to 100°C, and the reaction time is 1 to 12 h.

[0026] According to an embodiment of the present invention, the molar ratio of the diisocyanate, the alcohol or amine containing pyrrolidine or piperazine groups, the hydroxyl-terminated polyol, and the hydroxyl-containing (meth)acrylate is 1:(0.2-0.7):(0.1-0.5):(0.2-1.4), specifically 1:0.6:0.1:0.6.

[0027] In this invention, the photocurable monomer is selected from at least one of butyl acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, isobornyl acrylate, N-acryloylmorpholine, tert-butyl acrylate, 2-phenoxyethyl acrylate, polyethylene glycol diacrylate, hexanediol diacrylate, and trimethylolpropane triacrylate.

[0028] The photoinitiator is selected from at least one of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl (2,4,6-trimethylbenzoyl)phosphonate, benzophenone, isopropylthioxanthonone, 2,4-dimethylthioxanthonone, etc.

[0029] The epoxy resin is selected from at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenolic epoxy resin, hydrogenated bisphenol A type epoxy resin, tetraglycidyl diaminodiphenylmethane, alicyclic epoxy resin, etc.

[0030] According to one embodiment of the present invention, the hybrid photocurable resin system comprises the following components in parts by weight: 35 parts of polyurethane acrylate containing pyrrolidone bonds prepared in Example 1, 35 parts of 2-phenoxyethyl acrylate, 1 part of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and 30 parts of bisphenol A type epoxy resin.

[0031] According to another embodiment of the present invention, the hybrid photocurable resin system comprises the following components in parts by weight: 25 parts of polyurethane acrylate containing piperazine urea bonds prepared in Example 2, 20 parts of isobornyl acrylate, 2 parts of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and 55 parts of bisphenol A type epoxy resin.

[0032] The present invention also provides a method for preparing the above-mentioned hybrid photocurable resin system.

[0033] The preparation method of the hybrid photocurable resin system provided by the present invention includes the following steps: weighing the polyurethane (meth) acrylate containing dynamic reversible urea bonds, the acrylate photocurable diluent monomer, the photoinitiator, and the epoxy resin according to the proportion, pouring them into a stirrer, and mechanically stirring and mixing them under light-protected conditions to obtain the final product.

[0034] The mechanical stirring speed can be 100-400 r / min, and the stirring time can be 1-4 h.

[0035] The present invention also provides applications of the above-described photocurable resin system.

[0036] The application of the photocurable resin system provided by the present invention is its use in photocurable 3D printing, especially in stereolithography (SLA), digital light processing photocurable 3D printing (DLP), and continuous liquid interface (CLIP) printing.

[0037] The photocurable 3D printing material with excellent mechanical properties provided by this invention is obtained by photocuring the hybrid photocurable resin system provided by this invention in a mold for 3D printing, and then sequentially undergoing ultraviolet light curing and thermal curing.

[0038] Furthermore, after the above-mentioned photopolymerization 3D printing is completed and before ultraviolet light curing, the obtained sample is also cleaned.

[0039] The cleaning process can be performed using ethanol or isopropanol. Specifically, the sample blank can be placed in ethanol or isopropanol and ultrasonically cleaned for 10 minutes.

[0040] The UV curing process is as follows: UV curing is performed in a UV chamber for 5-20 minutes.

[0041] The thermosetting process is as follows: curing is carried out in an oven by heating at a temperature of 120-180℃ for 2-6 hours.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] (1) The dynamic reversible urea bond dissociates only at high temperature to generate active groups, ensuring that the mixed resin has excellent storage and processing stability.

[0044] (2) The flexible polyurethane segment can efficiently absorb and disperse the shrinkage stress generated during the thermosetting process, significantly suppress the accumulation of internal stress and avoid the risk of cracking.

[0045] (3) Through the good compatibility of polyurethane (meth)acrylate with dynamic reversible urea bonds and epoxy resin, dual curing mechanism and dynamic exchange of reversible bonds, the hybrid photocurable resin system eventually forms a highly uniform single network structure instead of an interpenetrating polymer network structure.

[0046] (4) The photopolymer 3D printing material with excellent mechanical properties provided by the present invention has a tensile strength of up to 60 MPa and an elongation at break of up to 10.4%. Attached Figure Description

[0047] Figure 1 The image shown is the NMR spectrum of the polyurethane acrylate containing reversible pyrrolidone bonds prepared in Example 1 of this invention.

[0048] Figure 2The image shown is the infrared spectrum of the polyurethane acrylate containing reversible piperazine urea bonds prepared in Example 2 of this invention.

[0049] Figure 3 The image shown is a temperature-varying infrared spectrum of the polyurethane acrylate prepared in Example 1 of this invention.

[0050] Figure 4 The figure shows the viscosity of the acrylate / epoxy hybrid photocurable resin obtained in Example 3 of this invention as a function of time.

[0051] Figure 5 The image shows the real-time infrared spectrum of the acrylate / epoxy hybrid photocurable resin obtained in Example 3 of this invention during the ultraviolet curing process and the infrared spectrum after thermosetting.

[0052] Figure 6 The image shows a part printed using the hybrid resin prepared in Example 3 of this invention for digital light processing (DLP) type photopolymerization 3D printing.

[0053] Figure 7 The image shows the mechanical properties of the hybrid resin prepared in Example 3 of this invention after photo-thermal dual curing.

[0054] Figure 8 The image shows the mechanical properties of the hybrid resin prepared in Example 4 of this invention after photo-thermal dual curing. Detailed Implementation

[0055] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0056] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0057] Example 1: Preparation of polyurethane acrylate containing dynamic pyrrolidone

[0058] In a 500 mL round-bottom flask equipped with a mechanical stirrer, nitrogen inlet tube, thermometer, and dropping funnel, 55.5 g (250 mmol) of isophorone diisocyanate (IPDI) was added, and the temperature was raised to 60 °C. Then, a mixture of 13.05 g (150 mmol) of 3-pyrrolidone (i.e., 3-hydroxypyrrolidine), 50.0 g (25 mmol) of polytetrahydrofuran glycol (molecular weight 2000), and dimethylformamide (100 mL) was added dropwise to the flask, and the reaction extent was monitored by Fourier transform infrared spectroscopy. 0.06 g of n-butyltin laurate was added to continue the reaction. When the characteristic infrared absorption peak of the isocyanate group no longer changed, 17.5 g (150 mmol) of hydroxyethyl acrylate and 0.1 g of hydroquinone were added to the system, and the temperature of the reaction system in the flask was maintained at 60 °C. The reaction was stopped when the characteristic infrared absorption peak of the isocyanate group completely disappeared. The solvent in the system was removed by rotary evaporation at 90°C for 3 hours, thus obtaining the polyurethane acrylate containing pyrrolidone bonds.

[0059] Example 2: Preparation of polyurethane acrylate containing dynamic piperazine urea

[0060] In a 500 mL round-bottom flask equipped with a mechanical stirrer, nitrogen inlet tube, thermometer, and dropping funnel, 55.5 g (250 mmol) of isophorone diisocyanate (IPDI) was added, and the temperature was raised to 60 °C. Then, a mixture of 19.5 g (150 mmol) of N-hydroxyethylpiperazine, 50.0 g (25 mmol) of polytetrahydrofuran glycol (molecular weight 2000), and dimethylformamide (100 mL) was added dropwise to the flask, and the reaction extent was monitored by Fourier transform infrared spectroscopy. 0.08 g of n-butyltin laurate was added to continue the reaction. When the characteristic infrared absorption peak of the isocyanate group no longer changed, 17.5 g (150 mmol) of hydroxyethyl acrylate and 0.1 g of hydroquinone were added to the system, and the reaction temperature was maintained at 60 °C. The reaction was stopped when the characteristic infrared absorption peak of the isocyanate group completely disappeared. The solvent in the system was removed by rotary evaporation at 90 °C for 3 h, yielding a polyurethane acrylate containing dynamic piperazine urea bonds.

[0061] Example 3: Preparation of acrylate / epoxy hybrid photocurable resin

[0062] 2-phenoxyethyl acrylate (35.0 g), bisphenol A epoxy resin (30.0 g), and (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (1 g) were added to the polyurethane acrylate (35.0 g) containing pyrrolidone bonds prepared in Example 1. After mechanical stirring at 300 r / min for 1 h under light-protected conditions, a hybrid photocurable resin was obtained.

[0063] Example 4: Preparation of acrylate / epoxy hybrid photocurable resin

[0064] To the polyurethane acrylate (25.0 g) containing piperazine urea bonds prepared in Example 2, add isobornyl acrylate (20.0 g), bisphenol A type epoxy resin (55.0 g), and (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (2 g). After mechanical stirring at 300 r / min for 1 h under light-protected conditions, a hybrid photocurable resin is obtained.

[0065] Photocurable 3D printing materials were prepared using the acrylate / epoxy hybrid photocurable resins prepared in Examples 3 and 4 above. The specific method is as follows: The prepared acrylate / epoxy hybrid photocurable resin was poured into the resin tank of a DLP 3D printing device (EvoDent S110, Shanghai Lianchuang Technology Co., Ltd.), and 3D samples were printed. During the printing process, the layer thickness was set to 0.1 mm, the exposure time and LED power parameters were set to 6 s and 85 μW respectively, and the power density was 6.32 mW / cm². -2 After printing, residual resin on the sample surface was ultrasonically cleaned with ethanol. The cleaned sample was then placed in a 405nm UV curing chamber for 10 minutes for curing. Finally, the sample was placed in a 150℃ oven for heat curing for 6 hours to obtain the final cured sample.

[0066] Figure 1 The image shows the 1H NMR spectrum of the polyurethane acrylate containing reversible pyrrolidone bonds prepared in Example 1 of this invention. All signals in the spectrum can be clearly attributed to the corresponding protons in the polyurethane acrylate molecule, proving its successful preparation.

[0067] Figure 2 The image shown is the infrared spectrum of the polyurethane acrylate containing reversible piperazine urea bonds prepared in Example 2 of this invention. The characteristic absorption peaks (3329 and 1719 cm⁻¹) corresponding to the stretching vibrations of the NH and C=O bonds on the urethane groups are also shown. -1 Clearly distinguishable. Furthermore, the acrylate groups are visible at 1638 and 1620 cm⁻¹. -1 (C=C stretching vibration), 1408cm -1 (=CH2 bending vibration) and 812cm -1 The absorption peak at (C=C bending vibration) confirms the successful synthesis of polyurethane acrylate.

[0068] Figure 3 The image shown is a temperature-dependent infrared spectrum of the polyurethane acrylate prepared in Example 1 of this invention. The infrared spectrum shows that when the temperature is below 150°C, it cannot be detected at 2256 cm⁻¹. -1 The characteristic absorption peak at the point; when heated to 170℃, the absorption peak of the isocyanate group appears and gradually increases with increasing temperature, confirming the dynamic reversible nature of the pyrrolidone bond.

[0069] Figure 4 The figure shows the viscosity change curve of the acrylate / epoxy hybrid photocurable resin obtained in Example 3 of this invention over time. The results show that the viscosity of the hybrid resin remained stable after being placed at room temperature for one month, confirming the storage stability of this hybrid photocurable resin in 3D printing applications.

[0070] Figure 5 The display shows the real-time infrared spectrum of the acrylate / epoxy hybrid UV-curable resin obtained in Example 3 of this invention during the UV curing process and the infrared spectrum after thermosetting. The infrared spectra show that during UV irradiation, the acrylate groups are located at 1636 and 1405 cm⁻¹. -1 The characteristic absorption peak at 914 cm⁻¹ drops sharply, and disappears completely after 3 minutes of UV irradiation. During the photocuring process, the epoxy groups at 914 cm⁻¹... -1 The characteristic absorption peaks remained constant but disappeared after heat curing (6 hours at 150°C), indicating that the mixed resin exhibited excellent stability during UV curing. Therefore, when polyurethane acrylates containing reversible pyrrolidone bonds were used as curing agents, this mixed resin demonstrated excellent stability during both the storage and UV curing stages, thus solving one of the most critical challenges in the field of photothermal dual-curing resins: resin stability.

[0071] Figure 6 The image shows a part printed using the hybrid resin prepared in Example 3 of this invention for digital light processing (DLP) type photopolymerization 3D printing. Figure 6 As shown in Figure a, two cubic lattice structures were successfully printed using a DLP printer. Figure 6 The magnified image of the cubic lattice printed in step b shows that the object has a fine lattice structure and a smooth surface. Furthermore, after the second step of thermosetting, the cubic lattice remained intact, with no microcracks detected.

[0072] Figure 7 The images show the mechanical properties of the hybrid resin prepared in Example 3 of this invention after photocuring and the mechanical properties of the hybrid resin after photo-thermal dual curing. Figure 7 As shown in Figure a, the photocurable component in the hybrid resin, a mixture of polyurethane (meth)acrylate containing dynamically reversible urea bonds and photocurable monomers, exhibits a tensile strength of 19.5 ± 0.3 MPa and an elongation at break of 34.0 ± 2.1% after photocuring. Due to the alternating hard and soft segments of the polyurethane, the UV-curable component displays excellent toughness after UV curing, which helps dissipate the internal stress generated by the epoxy component during the second thermal curing process. Therefore, the molecular structure of this composite resin solves another major problem of dual-curing resin systems—the tendency to crack during the second thermal curing process. Figure 7As shown in Figure b, the tensile strength and elongation at break of the hybrid resin after UV curing and the second-step thermosetting treatment are 59.6±1.3MPa and 10.0±2.1%, respectively. Therefore, adding 30% epoxy resin to the UV-curing component can significantly improve the mechanical properties of the printed parts, with the tensile strength reaching 3.7 times the original value, without compromising the printing performance of the resin.

[0073] Figure 8 The images show the mechanical properties of the hybrid resin prepared in Example 4 of this invention after photocuring and the mechanical properties of the hybrid resin after photo-thermal dual curing. Figure 8 As shown in Figure a, the photocurable component in the hybrid resin, namely a mixture of polyurethane (meth)acrylate containing dynamically reversible urea bonds and photocurable monomers, exhibits a tensile strength of 25.2 ± 3.2 MPa and an elongation at break of 63.1 ± 5.6% after photocuring. Figure 8 As shown in Figure b, the tensile strength and elongation at break of the hybrid resin after UV curing and the second-step thermosetting treatment are 61.2±2.1MPa and 15.6±2.8%, respectively.

[0074] The present invention has been described in detail above. For those skilled in the art, the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. Although specific embodiments have been given, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein. Some of the essential features can be applied within the scope of the following appended claims.

Claims

1. A hybrid photocurable resin system for preparing photocurable 3D printing materials with excellent mechanical properties, characterized in that: The hybrid photocurable resin system comprises the following components in parts by weight: 20-40 parts of polyurethane (meth)acrylate containing dynamic reversible urea bonds, 20-40 parts of photocurable monomer, 0.1-5 parts of photoinitiator, and 10-80 parts of epoxy resin.

2. The hybrid photocurable resin system according to claim 1, characterized in that: The polyurethane (meth)acrylate containing dynamic reversible urea bonds is first obtained by reacting diisocyanate with an alcohol or amine containing pyrrolidine or piperazine groups or a hydroxyl-terminated polyol to obtain an isocyanate-terminated prepolymer, and then reacting it with a hydroxyl-containing (meth)acrylate to obtain the polyurethane (meth)acrylate containing dynamic reversible urea bonds. And / or, the photocurable monomer is selected from at least one of butyl acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, isobornyl acrylate, N-acryloylmorpholine, tert-butyl acrylate, 2-phenoxyethyl acrylate, polyethylene glycol diacrylate, hexanediol diacrylate, and trimethylolpropane triacrylate. And / or, the photoinitiator is selected from at least one of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl (2,4,6-trimethylbenzoyl)phosphonate, benzophenone, isopropylthioxanthonone, and 2,4-dimethylthioxanthonone; And / or, the epoxy resin is selected from at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenolic epoxy resin, hydrogenated bisphenol A type epoxy resin, tetraglycidyl diaminodiphenylmethane, and alicyclic epoxy resin.

3. The hybrid photocurable resin system according to claim 2, characterized in that: The diisocyanate is selected from at least one of toluene diisocyanate, hydrogenated phenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and phenylmethane diisocyanate; And / or, the pyrrolidine-containing alcohol or amine is selected from at least one of 3-hydroxypyrrolidine, pyrrolidine-2-methanol, and L-hydroxyproline; And / or, the alcohol or amine containing the piperazine group is selected from at least one of N-aminoethylpiperazine and N-hydroxyethylpiperazine; And / or, the hydroxyl-terminated polyol is selected from at least one of polyether polyol, polyester polyol, and polyolefin polyol; And / or, the hydroxyl-containing (meth)acrylate is selected from at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and hydroxybutyl methacrylate.

4. The hybrid photocurable resin system according to claim 3, characterized in that: The polyether polyol is selected from at least one of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran glycol; And / or, the polyester polyol is selected from at least one of polycaprolactone diol, polylactic acid diol, polyethylene adipate diol, and polybutylene adipate diol; And / or, the polyolefin polyol is selected from polybutadiene glycol; And / or, the number-average molecular weight of the hydroxyl-terminated polyol is 200 to 10000 g / mol.

5. The hybrid photocurable resin system according to any one of claims 1-4, characterized in that: The polyurethane (meth)acrylate containing dynamically reversible urea bonds is prepared by a method comprising the following steps: S1: In the presence of a catalyst, diisocyanate is mixed with an alcohol or amine containing pyrrolidine or piperazine groups, a hydroxyl-terminated polyol, and an organic solvent to undergo a stepwise addition polymerization reaction to obtain an isocyanate-terminated prepolymer. S2: The isocyanate-terminated prepolymer prepared above is reacted with hydroxyl-containing (meth)acrylate, and a polymerization inhibitor is added during the reaction to obtain a polyurethane (meth)acrylate solution. After removing the solvent by rotary evaporation, a polyurethane (meth)acrylate containing dynamic reversible urea bonds is obtained.

6. The hybrid photocurable resin system according to claim 5, characterized in that: In step S1, the catalyst is a tertiary amine catalyst or an organometallic catalyst; further, the tertiary amine catalyst is selected from at least one of the following: triethylenediamine, bis(dimethylaminoethyl) ether, and the organometallic catalyst is selected from at least one of the following: stannous octoate, n-butyltin laurate; And / or, in step S1, the organic solvent is selected from at least one of acetone, tetrahydrofuran, dimethyl sulfoxide, dimethylformamide, and dimethylacetamide; And / or, in step S1, the amount of catalyst used is 200-600 ppm; And / or, in step S1, the polymerization reaction temperature is 50-100°C and the reaction time is 1-12 hours; And / or, the molar ratio of the diisocyanate, the alcohol or amine containing pyrrolidine or piperazine groups, the hydroxyl-terminated polyol, and the hydroxyl-containing (meth)acrylate is 1:(0.2-0.7):(0.1-0.5):(0.2-1.4).

7. The hybrid photocurable resin system according to claim 5 or 6, characterized in that: In step S2, the polymerization inhibitor is selected from at least one of hydroquinone and p-methoxyphenol; And / or, in step S2, the amount of the polymerization inhibitor is 50-1000 ppm; the reaction temperature is 50-100°C, and the reaction time is 1-12 h.

8. A method for preparing a hybrid photocurable resin system according to any one of claims 1-7, comprising the following steps: weighing the polyurethane (meth) acrylate containing dynamic reversible urea bonds, the acrylate photocurable diluent monomer, the photoinitiator, and the epoxy resin according to the proportion, pouring them into a stirrer, and mechanically stirring and mixing them under light-protected conditions to obtain the final product.

9. The use of the hybrid photocurable resin system according to any one of claims 1-7 in photocurable 3D printing, especially in photocurable stereolithography, digital light processing photocurable 3D printing or continuous liquid interface printing.

10. A photocurable 3D printing material with excellent mechanical properties is obtained by photocuring the hybrid photocurable resin system according to any one of claims 1-7 in a mold for 3D printing, followed by UV curing and thermal curing.

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