Photo-thermal dual curable hyperbranched resin and synthesis method and ultraviolet light curable resin composition for 3D printing

Abstract

The application relates to a photo-thermal double-cured hyperbranched resin and a synthesis method and a UV-cured resin composition for 3D printing. A synthesis method of a photo-thermal double-cured hyperbranched resin is as follows: isocyanate and a catalyst 1 are put into a reaction kettle at 55-60 DEG C; 2,2-dimethylol butyric acid is dissolved in a diluent, then a mixture of tertiary butyl amino ethyl methacrylate and a polymerization inhibitor is added dropwise and kept at reaction temperature until an intermediate product A1 is obtained; a catalyst 2 is put in, the reaction continues at 65-70 DEG C, and an intermediate product A2 is obtained; the temperature is lowered to 55-60 DEG C, the mixture of tertiary butyl amino ethyl methacrylate and the polymerization inhibitor is added dropwise and kept at reaction temperature until the isocyanate value is less than 0.5%, and a photo-thermal double-cured hyperbranched resin is obtained; the resin has the characteristics of low viscosity, high functionality, high activity and reduced volume shrinkage, and can be used for preparing a UV-cured resin composition for 3D printing, so that the material has high rigidity and good toughness.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ultraviolet light-cured 3D printing materials, more specifically, it relates to a hyperbranched resin capable of dual curing by light and heat, a synthesis method thereof, and an ultraviolet light-cured resin composition for 3D printing. BACKGROUND

[0002] With the rapid development of manufacturing industry, especially in the fields of product rapid prototyping, small-batch customized production and complex structure manufacturing, 3D printing technology gradually stands out with its unique flexibility and high efficiency. Among them, the 3D printing technology based on resin materials shows great potential in injection mold manufacturing, and becomes an effective supplement to metal molds in specific application scenarios. Resin molds not only can effectively reduce production cost and shorten product development cycle, but also can quickly verify the feasibility and manufacturability of product design in the trial production stage, providing valuable data support for subsequent batch production.

[0003] However, the current 3D printing resin materials for injection mold on the market still face many challenges in performance and application, which are specifically reflected in the following aspects:

[0004] 1. Brittleness problem: Although the existing high-temperature-resistant 3D printing mold resin can maintain good stability at high temperatures, i.e., it has a high heat distortion temperature and rigidity, the brittleness of the material itself limits its application range. In actual use, the mold is prone to cracking, breaking and other phenomena due to external impact or internal stress concentration, which not only affects the service life of the mold, but also increases the risk and cost in the production process.

[0005] 2. Volume shrinkage and deformation problem: Resin materials often accompany significant volume shrinkage during the curing process, especially when printing large or regular-shaped models. This volume change may cause the model to bend and deform, seriously affecting the dimensional accuracy and surface quality of the model. In addition, the large volume change also makes it difficult to directly apply the printed model to the injection molding machine, limiting its direct application in industrial production.

[0006] 3. Material stability and storage problem: In order to improve the heat distortion temperature, a large amount of solid multifunctional resin with rigid rings is usually added in the existing technology. However, this type of resin has high viscosity, although it can effectively improve the heat resistance of the material, it also brings problems such as increased viscosity and poor storage stability. For example, high-viscosity resin is prone to solid precipitation during storage, especially in low-temperature environments, the entire formulation may become completely solid, which brings great inconvenience to use and also affects the performance stability of the printed model.

[0007] Therefore, the existing 3D printing injection mold resin material has problems in brittleness, volume shrinkage and deformation, material stability and storage, which seriously restricts its wide application in high-precision and high-demand 3D printing scenarios. Therefore, developing a kind of ultraviolet curing resin for 3D printing which has excellent heat resistance, rigidity and toughness, does not crack and break, and can effectively control the volume shrinkage and improve the storage stability of the material, is of great significance to promote the further development of 3D printing technology in the field of injection mold manufacturing. SUMMARY

[0008] In order to solve the above problems, the present application provides a kind of photothermal dual-cured hyperbranched resin for 3D printing and its synthesis method and ultraviolet curing resin composition.

[0009] In the first aspect, the present application provides a kind of synthesis method of photothermal dual-cured hyperbranched resin, adopts the following technical scheme:

[0010] A kind of synthesis method of photothermal dual-cured hyperbranched resin, comprising the following steps:

[0011] Step 1: the reaction kettle is heated to 55-60℃, the isocyanate, catalyst 1 is put into the reaction kettle, and is stirred uniformly;

[0012] The isocyanate at least contains a mixture of one or more of toluene diisocyanate, p-phenylene diisocyanate and isophorone diisocyanate;

[0013] Catalyst 1 at least contains a mixture of one or more of dibutyltin dilaurate, stannous octoate and organic bismuth;The amount of catalyst 1 is 0.05-0.3% of the mass of isocyanate;

[0014] Step 2: mix 2,2-dimethylol butyric acid and diluent uniformly, then add to the reaction kettle at a certain speed, after dropping, keep the temperature at 55-60℃, to obtain intermediate product A1;

[0015] The molar ratio of 2,2-dimethylol butyric acid to isocyanate is 1:2;

[0016] Step 3: put in catalyst 2, control the temperature at 65-70℃, and make the intermediate product A1 continue to react to obtain intermediate product A2;

[0017] Catalyst 2 at least includes a mixture of one or more of magnesium stearate, tributylphosphine and triethylenediamine;

[0018] The amount of catalyst 2 is 0.01-0.1% of the total mass of isocyanate and 2,2-dimethylol butyric acid;

[0019] Step 4: After cooling to 55-60℃, the tert-butyl amino ethyl methacrylate and the polymerization inhibitor are mixed uniformly, and then added to the reaction kettle at a certain speed. After the addition is completed, the reaction is kept at 55-60℃ until the isocyanate value is less than 0.5%, and the final product A3, i.e. the light-heat dual-curable hyperbranched resin, is obtained.

[0020] In this step, since the isocyanate is capped with tert-butyl amino ethyl methacrylate (TBAEMA) monomer, the isocyanate will be uncapped after heating, and the isocyanate can further crosslink with the polyol (thermal curing) as the temperature rises, so that the material has high rigidity and good toughness at the same time.

[0021] By adopting the technical scheme, the light-heat dual-curable hyperbranched resin synthesized by the application has the characteristics of low viscosity, high functionality and high activity, and has a highly branched three-dimensional structure, which has the potential to reduce volume shrinkage, thereby solving the problem of model bending deformation due to volume change when printing large or regular-shaped models, and further improving the overall accuracy of the printed model. On the other hand, the resin has the characteristics of light-heat dual-curing, which can be cured under ultraviolet light and can also be thermally cured, i.e. the terminal isocyanate can be uncapped at a certain temperature, and the isocyanate can further crosslink as the temperature rises, so that the crosslinking degree and molecular weight of the material will be greatly improved, so that the material has high rigidity and good toughness at the same time, thereby solving the problems of cracking, breaking and bending deformation of the model during printing and use. In addition, compared with the high-viscosity solid multi-functional resin with rigid rings used in the prior art, the light-heat dual-curable hyperbranched resin synthesized by the application has low viscosity, does not precipitate from the formula during storage, does not become a solid at low temperature, and has a high heat distortion temperature, thereby solving the problems of storage and stability.

[0022] Preferably, the diluent is morpholine acrylate, and the amount of the diluent is 40-60% of the total mass of the isocyanate and 2,2-dimethylol butyric acid.

[0023] Preferably, the polymerization inhibitor at least contains one of p-hydroxyanisole, hydroquinone and p-tert-butyl hydroquinone.

[0024] Preferably, the polymerization inhibitor at least contains one of p-hydroxyanisole, hydroquinone and p-tert-butyl hydroquinone; and the amount of the polymerization inhibitor is 0.1-0.3% of the mass of the tert-butyl amino ethyl methacrylate.

[0025] Preferably, in step 2, the dropping speed of the mixture of 2,2-dimethylol butyric acid and diluent is 25-35 mL / min; in step 4, the dropping speed of the mixture of tert-butyl aminoethyl methacrylate and polymerization inhibitor is 25-35 mL / min.

[0026] The reaction process of steps 1-4 is shown as follows:

[0027]

[0028]

[0029] In a second aspect, the application provides a hyperbranched resin capable of dual curing by light and heat.

[0030] In a third aspect, the application provides the use of a hyperbranched resin capable of dual curing by light and heat in the preparation of a resin composition for 3D printing injection molds.

[0031] In a fourth aspect, the application provides a UV-curable resin composition for 3D printing, which adopts the following technical solution:

[0032] A UV-curable resin composition for 3D printing, according to mass percentage, comprises the following raw materials: 20-30% of the above-synthesized hyperbranched resin capable of dual curing by light and heat, 5-8% of polyol, 25-45% of alumina, 1.5-2.5% of initiator, 25-35% of monomer, and 0.1-0.5% of auxiliary agent.

[0033] The hyperbranched resin capable of dual curing by light and heat can be unblocked at the end isocyanate at a certain temperature, and the isocyanate and polyol react as the temperature rises, which greatly improves the crosslinking degree and molecular weight of the material, making the material have high rigidity, high heat distortion temperature, and certain toughness, and the model is not prone to cracking and breaking in actual application.

[0034] The use amount and matching relationship of the raw materials are limited, which can effectively improve the stability and mechanical properties of the obtained material during the curing process, ensure the dimensional accuracy and heat resistance of the 3D printing injection mold resin composition after molding, and reduce the deformation risk of the model during the printing process.

[0035] Preferably, the polyol is a poly(lactide-co-caprolactone) ternary alcohol modified by polypropylene glycol, with a molecular weight of 4000 and a hydroxyl group of 42, which is purchased from Hunan Juren New Material Technology Co., Ltd. and has a product model of 3400P.

[0036] Preferably, the monomer at least contains one of dipentaerythritol hexaacrylate and tricyclodecane dimethanol diacrylate.

[0037] Preferably, the alumina is a spheroidal alumina powder with a particle size of 10000-15000 mesh.

[0038] In a fifth aspect, the application provides a preparation method of a UV-curable resin composition for 3D printing.

[0039] A preparation method of a UV-curable resin composition for 3D printing, comprising the following steps: mixing the photo-thermal dual-curable hyperbranched resin, polyol, alumina, initiator, monomer and additive to be uniform at 55-60°C, to obtain a UV-curable resin composition for 3D printing.

[0040] The thermal curing reaction of the above-mentioned UV-curable resin composition for 3D printing is shown as follows:

[0041]

[0042] In summary, the application has the following beneficial effects:

[0043] 1. By synthesizing a photo-thermal dual-curable hyperbranched resin, the brittleness of the mold resin material is significantly reduced, the toughness is improved, and the problem of cracking and breaking of the mold during use is effectively avoided.

[0044] 2. The highly branched three-dimensional structure of the photo-thermal dual-curable hyperbranched resin effectively reduces the volume shrinkage of the material during curing, avoids the bending deformation of the 3D printed large or regular-shaped model, and improves the overall precision and surface quality of the model.

[0045] 3. The photo-thermal dual-curable hyperbranched resin has low viscosity, which improves the storage stability of the mold resin material, reduces the precipitation of solid multifunctional resin during storage, ensures the flowability of the material under low temperature conditions, and improves the performance stability and consistency of the printed model.

[0046] 4. The photo-thermal dual-curable hyperbranched resin has photo-thermal dual-curing properties, which can not only be cured under ultraviolet light, but also the terminal isocyanate can be deblocked at a certain temperature and further crosslink with polyol at high temperature, the crosslinking degree and molecular weight of the prepared resin composition are greatly improved, so that the material has high rigidity and good toughness, and the problem of model cracking and breaking during 3D printing is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is the design drawing of the model making and processing of the UV-curable resin composition for 3D printing of Example 1 in the performance detection test.

[0048] Figure 2is a picture of printing a model after the UV-curable resin composition for 3D printing of Example 1 in the performance detection experiment.

[0049] Figure 3 is a picture of model cleaning after the UV-curable resin composition for 3D printing of Example 1 in the performance detection experiment.

[0050] Figure 4 is a picture of the model of the UV-curable resin composition for 3D printing of Example 1 in the performance detection experiment being placed in the curing box.

[0051] Figure 5 is a picture of the finished product of the model printed by the UV-curable resin composition for 3D printing of Example 1 in the performance detection experiment. DETAILED DESCRIPTION

[0052] The present application is further described in detail below with reference to the accompanying drawings and examples.

[0053] The raw materials used in the following examples and comparative examples are all commercially available products.

[0054] Example

[0055] A UV-curable resin composition for 3D printing is prepared as follows:

[0056] Step 1: Synthesis of a hyperbranched resin capable of dual photocuring and thermal curing

[0057] Step 1: After the reaction kettle is heated to 55-60°C, the isocyanate and catalyst 1 are sequentially added and stirred uniformly.

[0058] The isocyanate is one or more of toluene diisocyanate, p-phenylene diisocyanate, and isophorone diisocyanate.

[0059] The catalyst 1 is one or more of dibutyltin dilaurate, stannous octoate, and organic bismuth.

[0060] The amount of catalyst 1 is 0.01-0.3% of the mass of the isocyanate.

[0061] Step 2: 2,2-dimethylol butyric acid (DMBA) is dissolved in the diluent and added dropwise into the reaction kettle at a rate of 25-35 mL / min. After the dropwise addition is complete, the reaction is carried out at 55-60°C until the isocyanate value reaches the specified value, to obtain intermediate product A1.

[0062] The molar ratio of 2,2-dimethylol butyric acid to isocyanate is 1:2.

[0063] The diluent is morpholine acrylate (ACMO), and the amount is 40-60% of the total mass of isocyanate and 2,2-dimethylol butyric acid.

[0064] Step 3: Add catalyst 2 to the reaction kettle, heat to 65-70°C, and react until the isocyanate value reaches the specified value to obtain intermediate product A2.

[0065] Catalyst 2 is a mixture of one or more of magnesium stearate, tributylphosphine, and triethylenediamine.

[0066] The amount of catalyst 2 is 0.01-0.1% of the total mass of isocyanate and 2,2-dimethylol butyric acid.

[0067] Step 4: After cooling to 55-60°C, mix the tertiary butyl amino ethyl methacrylate (TBAEMA) and the polymerization inhibitor uniformly, then add it into the reaction kettle at a speed of 25-35 mL / min, and after the addition is completed, react at 55-60°C until the isocyanate value is less than 0.5% to obtain product A3, which is a hyperbranched resin that can be cured by light and heat.

[0068] The polymerization inhibitor is a mixture of one or more of p-hydroxyanisole, hydroquinone, and p-tert-butylcatechol.

[0069] The amount of polymerization inhibitor is 0.1-0.3% of the mass of tertiary butyl amino ethyl methacrylate.

[0070] In the above steps, the determination method of isocyanate value refers to the standard: HG / T 2409-2023 Determination of Isocyanate Group Content in Polyurethane Prepolymer.

[0071] Step 2, preparation of the composition

[0072] Mix the light and heat dual-curable hyperbranched resin prepared in step 1 with polyol, aluminum oxide, initiator, monomer, and auxiliary agent uniformly at 55-60°C to obtain an ultraviolet light curing resin composition for 3D printing.

[0073] According to the mass percentage, the light and heat dual-curable hyperbranched resin is 20-30%, the polyol is 5-8%, the aluminum oxide is 25-45%, the initiator is 1.5-2.5%, the monomer is 25-35%, and the auxiliary agent is 0.1-0.5%.

[0074] The polyol is a polybutylene glycol modified polycaprolactone triol with a molecular weight of 4000 and a hydroxyl group of 42, purchased from Hunan Polyren New Material Technology Co., Ltd., and the product model is 3400P.

[0075] The aluminum oxide is a spherical aluminum oxide powder with 10000-15000 mesh.

[0076] The initiator is TPO.

[0077] The monomer is one or more of dipentaerythritol hexaacrylate, tricyclodecane dimethanol diacrylate.

[0078] Example 1

[0079] A UV-curable resin composition for 3D printing is prepared as follows:

[0080] Step 1: Synthesis of photo-thermal dual-curable hyperbranched resin

[0081] Step 1: After the reaction kettle is heated to 58℃, the isocyanate and catalyst 1 are sequentially added and stirred uniformly.

[0082] The isocyanate is isophorone diisocyanate.

[0083] Catalyst 1 is organic bismuth.

[0084] The amount of catalyst 1 is 0.1% of the mass of the isocyanate.

[0085] Step 2: 2,2-dimethylol butyric acid is dissolved in the diluent and added dropwise into the reaction kettle at a rate of 30 mL / min. After the addition is complete, the reaction is carried out at 58℃ to obtain intermediate product A1.

[0086] The molar ratio of 2,2-dimethylol butyric acid to isocyanate is 1:2.

[0087] The diluent is morpholine acrylate, and the amount used is 50% of the total mass of the isocyanate and 2,2-dimethylol butyric acid.

[0088] Step 3: Catalyst 2 is added to the reaction kettle, heated to 68℃, and reacted until the isocyanate value reaches the calculated value to obtain intermediate product A2.

[0089] Catalyst 2 is magnesium stearate.

[0090] The amount of catalyst 2 is 0.05% of the total mass of the isocyanate and 2,2-dimethylol butyric acid.

[0091] Step 4: Cool to 58℃, mix the tert-butyl aminoethyl methacrylate and the polymerization inhibitor uniformly, then add dropwise into the reaction kettle at a rate of 30 mL / min. After the addition is complete, the reaction is carried out at 58℃ until the isocyanate value is less than 0.5% to obtain product A3, a photo-thermal dual-curable hyperbranched resin.

[0092] The polymerization inhibitor is p-hydroxyanisole.

[0093] The amount of polymerization inhibitor is 0.15% of the mass of the tert-butyl aminoethyl methacrylate.

[0094] Step two, preparation of the composition

[0095] According to the mass percentage, 25% of the photothermal double-cured hyperbranched resin prepared in step one, 5% of the polyol, 40% of the alumina, 1.5% of the initiator, 28.2% of the monomer, and 0.3% of the auxiliary agent were mixed at 58°C until uniform to obtain a UV-curable resin composition for 3D printing.

[0096] The polyol refers to a polycaprolactone triol modified with polypropylene glycol, with a molecular weight of 4000 and a hydroxyl group of 42.

[0097] The alumina is a spherical alumina powder with 12500 mesh.

[0098] The initiator is TPO.

[0099] The monomer is 15% di-pentaerythritol hexaacrylate and 13.2% tricyclodecane dimethylol diacrylate.

[0100] The auxiliary agent is BYK410.

[0101] The amounts of raw materials used to prepare the photothermal double-cured hyperbranched resin are shown in Table 1, and the amounts of raw materials used to prepare the UV-curable resin composition for 3D printing are shown in Table 2.

[0102] Examples 2-5

[0103] A UV-curable resin composition for 3D printing, the main preparation method is the same as example 1, the difference is that the selection and amount of part of the raw materials in step one and step two are different, see table 1 and table 2.

[0104] Comparative example

[0105] Comparative example 1

[0106] A resin composition for 3D printing, the main preparation method is the same as example 1, the difference is that:

[0107] The monomer used in step 4 is hydroxyethyl acrylate (HEA) instead of tert-butyl aminoethyl methacrylate (TBAEMA) in example 1.

[0108] Comparative example 2

[0109] A resin composition for 3D printing, which is different from example 1 in that the polyol is omitted.

[0110] Comparative example 3

[0111] A resin composition for 3D printing, which is different from example 2 in that the polyol is omitted.

[0112] Comparative example 4

[0113] A resin composition for 3D printing, which differs from Example 3 in that the polyol is omitted.

[0114] The specific components and amounts of the above Examples 1-5, Comparative Examples 1-4 are shown in Tables 1 and 2.

[0115] Table 1

[0116]

[0117] Table 2

[0118]

[0119]

[0120] Performance test The resin compositions prepared using Examples 1-5, Comparative Examples 1-4 were used to 3D print models, and the models were tested for performance. The performance data are shown in Table 3.

[0121] I. Related parameters and operations of the printed models are as follows:

[0122] 1. 3D printing equipment parameters: pull-up type 450 nm LCD 3D printer, light source intensity 5000 uw / cm 2 , slice layer thickness 0.05 mm, layer exposure time 4.5 s, bottom layer exposure time 60 s.

[0123] 2. Post-processing method of the printed model:

[0124] 1) Place the model in 95% alcohol and clean it using an ultrasonic cleaner for 3 min. Replace the clean alcohol and clean it again using an ultrasonic cleaner for 3 min.

[0125] 2) Place the model in the curing oven after setting the temperature of the ultraviolet curing oven to 50°C. Turn on the ultraviolet light of the curing oven and cure at a constant temperature for 30 min.

[0126] 3) Place the model in an oven at 120°C and heat cure for 120 min.

[0127] The related process diagram of Example 1 is shown in Figures 1-5 .

[0128] II. The reference standards for performance testing are as follows:

[0129] 1. Bending strength test method: GB / T 9341-2008 "Determination of the bending properties of plastics".

[0130] 2. Impact strength test method: GB / T 1843-2008 "Determination of the Izod impact strength of plastics".

[0131] 3. Volume shrinkage test method: shrinkage = (p after - p before) / p after x 100%, wherein p after and p before are the densities after curing and before curing, respectively.

[0132] Detection index explanation: toughness is reflected by the detection index of impact strength, and rigidity is reflected by the index of bending strength, that is, the higher the impact strength, the better the material toughness; the higher the bending strength, the better the material rigidity.

[0133] Table 3

[0134]

[0135] According to Table 3, the detection results of Examples 1-5 and Comparative Examples 1-4 show that:

[0136] 1. The ultraviolet light curing resin composition of Examples 1-5, because the isocyanate in the light-heat dual-curing hyperbranched resin synthesized in step one is capped with t-butyl aminoethyl methacrylate (TBAEMA) monomer, the isocyanate will be uncapped after heating, and as the temperature rises, the isocyanate and polyol will undergo crosslinking reaction (thermal curing), at this time the crosslinking degree and molecular weight of the material will greatly increase, thereby improving the toughness of the material while maintaining high rigidity.

[0137] In the synthesis reaction of the light-heat dual-curing hyperbranched resin in Comparative Example 1, the monomer hydroxyethyl acrylate (HEA) is used for capping, and HEA cannot uncaps the isocyanate under thermal curing. Therefore, despite the addition of polyol in the resin composition formula, it cannot achieve the relevant effect; on the contrary, because the polyol cannot participate in the reaction, the material performance tends to deteriorate.

[0138] According to the detection data in Table 3, the ultraviolet light curing resin composition of Examples 1-5 exhibits good performance with rigidity and toughness compared to Comparative Examples 1-4. The improvement in material toughness solves the problem of cracking and fragility of 3D printed models caused by excessive rigidity; at the same time, it also reduces the volume shrinkage, and the shrinkage of Examples 1-5 is reduced to below 3.6%.

[0139] 1. The difference between the resin composition of Comparative Example 2 and Example 1 is that Comparative Example 2 does not use polyol. Since no polyol is added to the composition, thermal curing cannot play a role, and therefore it is not possible to achieve toughening, and the material impact strength is low. Similarly, the same applies to Comparative Example 3 and Example 2, and Comparative Example 4 and Example 3.

[0140] The embodiments are only illustrative of the present application, and are not intended to limit the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A UV-curable resin composition for 3D printing, characterized in that: The raw materials include the following according to mass percentage: 20-30% of a hyperbranched resin capable of dual curing with light and heat, 5-8% of a polyol, 25-45% of aluminum oxide, 1.5-2.5% of an initiator, 25-35% of a monomer, and 0.1-0.5% of an additive; The method for synthesizing the hyperbranched resin capable of photothermal dual curing comprises the following steps: Step 1: Heat the reactor to 55-60°C, add isocyanate and catalyst 1 into the reactor, and stir evenly; The isocyanate comprises at least one or more of toluene diisocyanate, p-phenylene diisocyanate, and isophorone diisocyanate; Catalyst 1 comprises at least a mixture of one or more of dibutyltin dilaurate, stannous octoate, and organic bismuth; the amount of catalyst 1 is 0.05-0.3% of the mass of the isocyanate; Step 2: 2,2-dihydroxymethylbutyric acid and a diluent are mixed evenly, and then added dropwise to a reaction kettle at a certain speed. After the addition is complete, the mixture is kept at 55-60°C for reaction to obtain an intermediate product A1; The molar ratio of 2,2-dihydroxymethylbutyric acid to isocyanate is 1:2; Step 3: Add catalyst 2 and control the temperature at 65°C-70°C to allow intermediate product A1 to continue reacting to obtain intermediate product A2; Catalyst 2 comprises at least a mixture of one or more of magnesium stearate, tributylphosphine, and triethylenediamine; The amount of catalyst 2 is 0.01-0.1% of the total mass of isocyanate and 2,2-dimethylolbutyric acid; Step 4: After cooling to 55-60°C, tert-butylaminoethyl methacrylate and the polymerization inhibitor are mixed evenly, and then added dropwise to the reactor at a certain speed. After the addition is completed, the reaction is kept at 55-60°C until the isocyanate value is less than 0.5%, thereby obtaining the final product A3, which is a photothermal dual-curing hyperbranched resin.

2. The UV-curable resin composition for 3D printing according to claim 1, wherein: The diluent is morpholine acrylate, and the amount of the diluent is 40-60% of the mass of the isocyanate and the 2,2-dihydroxymethylbutyric acid.

3. The UV-curable resin composition for 3D printing according to claim 1, wherein: The polymerization inhibitor contains at least one of p-hydroxyanisole, hydroquinone, and p-tert-butylcatechol; and the dosage of the polymerization inhibitor is 0.1-0.3% of the mass of tert-butylaminoethyl methacrylate.

4. The UV-curable resin composition for 3D printing according to claim 1, wherein: In step 2, the mixture of 2,2-dihydroxymethylbutyric acid and the diluent is added at a rate of 25-35 mL / min; and in step 4, the mixture of tert-butylaminoethyl methacrylate and the polymerization inhibitor is added at a rate of 25-35 mL / min.

5. The UV-curable resin composition for 3D printing according to claim 1, wherein: The polyol is polycaprolactone triol modified with polypropylene glycol.

6. The UV-curable resin composition for 3D printing according to claim 1, wherein: The monomer comprises at least one of dipentaerythritol hexaacrylate and tricyclodecane dimethanol diacrylate.

7. The method for preparing the UV-curable resin composition for 3D printing according to any one of claims 1 to 6, wherein: Under the condition of 55-60° C., the hyperbranched resin capable of photothermal dual curing, polyol, aluminum oxide, initiator, monomer and auxiliary agent are mixed until uniform, so as to obtain a UV-curable resin composition for 3D printing.

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