A single-component dual-curing 3D printing photosensitive resin and elastomer material incorporating a "latent" reaction source, and its preparation method.

Abstract

This invention provides a single-component, dual-curing 3D printing photosensitive resin, elastomer material, and preparation method incorporating a "latent" reaction source, relating to the field of 3D printing technology. The photosensitive resin, by weight, comprises the following raw materials: 70-90 parts of methacrylate-terminated polyurethane prepolymer, 1-5 parts of a dehydrating compound under heating conditions, 5-15 parts of an reactive diluent, and 1-5 parts of a photoinitiator. The structural formula of the methacrylate-terminated polyurethane prepolymer is shown in Formula II. The photosensitive resin of this invention introduces a dehydrating substance that can be heated to a specific temperature as a "latent" reaction source. In the post-printing processing stage, dehydration is triggered by heating, and the released water molecules react with some isocyanate groups in the system, generating a highly active diamine chain extender in situ, which then undergoes a highly efficient chain extension reaction with the remaining isocyanate.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, specifically to a single-component dual-curing 3D printing photosensitive resin, elastomer material, and preparation method that incorporates a "latent" reaction source. Background Technology

[0002] 3D printing technology, especially those based on stereolithography (SLA) and digital light processing (DLP), has demonstrated significant advantages in rapid prototyping, personalized customization, and small-batch production due to its high precision, high efficiency, and excellent surface quality. The core material of this technology—photosensitive resin—can rapidly cure under ultraviolet light, determining the initial properties of the printed part. However, traditional single-component photocurable resins mainly rely on photo-initiated free radical or cationic polymerization, which limits their curing depth. Furthermore, printed parts often suffer from inherent defects such as insufficient mechanical properties and poor heat resistance, making it difficult to meet the growing demand for high-performance engineering components.

[0003] To overcome the aforementioned limitations, the "dual-curing" system has emerged and become a research hotspot. This system typically achieves precise shape shaping through photocuring in the first stage, followed by deep cross-linking through thermocuring or other methods in the second stage, thereby significantly improving the final material performance. Among these, dual-curing systems incorporating polyurethane chemistry are highly favored due to their strong designability and excellent product performance. However, existing single-component polyurethane photosensitive resins face severe technical challenges. If isocyanates (-NCO) are premixed with active hydrogen compounds (such as polyols and amines), the system exhibits extremely poor storage stability and is prone to gelation. Patent CN 120682116 A discloses a blocked diamine chain extender, a dual-curing photosensitive resin, and its preparation method. To avoid gelation, the diamine chain extender is blocked, which improves system stability. However, once blocked, the diamine is difficult to unblock, and different degrees of unblocking result in variations in the performance of the final 3D printed product. If a two-component system is used to avoid this problem, the significant advantages of single-component systems—ease of operation and applicability to existing printing equipment—are lost. Therefore, ensuring good storage stability of single-component systems while significantly improving the performance of printed materials has become a critical challenge in this field. Developing a novel and efficient latent crosslinking mechanism to achieve a perfect balance between storage stability and high performance is therefore of paramount importance for promoting the practical application of high-performance 3D printing materials. Summary of the Invention

[0004] The purpose of this invention is to provide a single-component, dual-curing 3D printing photosensitive resin, elastomer material, and preparation method that combines a "latent" reaction source. The core of this invention lies in the creative introduction of a dehydrated substance that can be heated to a specific temperature as a "latent" reaction source. During the post-printing processing, dehydration is triggered by heating. The released water molecules react with some of the isocyanate groups in the system, generating a highly active diamine chain extender in situ, which then undergoes a highly efficient chain extension reaction with the remaining isocyanate. This design cleverly solves the industry problem of poor storage stability and difficulty in achieving optimal final material performance in traditional single-component systems.

[0005] This invention provides a single-component, dual-curing photosensitive resin for 3D printing that incorporates a "latent" reaction source, comprising the following raw materials by weight:

[0006] 70-90 parts of methacrylate-terminated polyurethane prepolymer

[0007] 1-5 parts of a compound that can be dehydrated under heating conditions

[0008] 5-15 parts of reactive diluent

[0009] 1-5 parts of photoinitiator

[0010] The structural formula of the methacrylate-terminated polyurethane prepolymer is shown in Formula II:

[0011] Formula II

[0012] In Equation II, m = 5~10; R1 is , or R2 is or .

[0013] Preferably, the dehydrating compound under heating conditions is a dehydrating crystalline hydrate, hydroxide, or molecular sieve.

[0014] Preferably, the dehydrated crystalline hydrate is copper sulfate pentahydrate CuSO4·5H2O, calcium chloride dihydrate CaCl2·2H2O, or magnesium sulfate heptahydrate MgSO4·7H2O, the hydroxide is magnesium hydroxide Mg(OH)2 or aluminum hydroxide Al(OH)3, and the molecular sieve is 4A molecular sieve activated powder.

[0015] This invention also provides a method for preparing the above-mentioned single-component dual-curing 3D printing photosensitive resin combined with a "latent" reaction source, comprising:

[0016] Step 1: Under nitrogen protection, diisocyanate, diol, catalyst dibutyltin dilaurate (DBTDL) and solvent N,N-dimethylformamide (DMF) are added sequentially to the reaction vessel to react and obtain the isocyanate-terminated oligomer shown in Formula I.

[0017] Formula I

[0018] In Equation I, m = 5~10, and R1 is... , or R2 is or ;

[0019] Step 2: Under a nitrogen atmosphere, the isocyanate-terminated oligomer obtained in Step 1 is reacted with tert-butylaminoethyl methacrylate (TBAEMA) and solvent N,N-dimethylformamide (DMF) in a reaction vessel to obtain the methacrylate-terminated polyurethane prepolymer shown in Formula II.

[0020] Formula II

[0021] In Equation II, m = 5~10, and R1 is... , or R2 is or ;

[0022] Step 3: Mix the methacrylate-terminated polyurethane prepolymer obtained in Step 2, the dehydrable compound under heating conditions, the reactive diluent, and the photoinitiator uniformly at room temperature to prepare a one-component photosensitive resin.

[0023] Preferably, the molar ratio of isocyanate groups to tert-butylaminoethyl methacrylate in the isocyanate-encapsulated oligomer of step two is 1:(1~1.1).

[0024] Preferably, the reaction temperature in step two is 65~85℃ and the reaction time is 4~6 hours.

[0025] Preferably, the reactive diluent in step three is dipropylene glycol diacrylate, and the photoinitiator is diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride.

[0026] The present invention also provides an elastomer material comprising the above-described single-component dual-curing 3D printing photosensitive resin incorporating a "latent" reaction source.

[0027] This invention also provides a method for preparing the above-mentioned elastomer material, comprising:

[0028] Step 1: Inject the photosensitive resin into the material tank of the photocuring 3D printer and photocur it to obtain the photocured product shown in Formula III;

[0029] Formula III

[0030] In Equation III, m = 5~10, and R1 is... , or R2 is or ;

[0031] Step 2: Place the photocured product obtained in Step 1 in an oven for programmed temperature rise thermocuring reaction to obtain an elastomer material including the chemical structural formula IV;

[0032] Formula IV

[0033] In Equation IV, m = 5~10, n = 10~100, and R1 is... , or R2 is or .

[0034] Preferably, the initial temperature of the programmed temperature rise thermosetting process in step two is 80~100℃, the final heating temperature is 120~150℃, and the programmed temperature rise process lasts for 8~12 hours.

[0035] Beneficial effects of the present invention

[0036] This invention provides a single-component, dual-curing 3D printing photosensitive resin, elastomer material, and preparation method that combines a "latent" reaction source. The core of this invention lies in the innovative introduction of a heat-dehydrated substance as a "latent" reaction source. This design cleverly solves the industry problem of poor storage stability and difficulty in achieving optimal final material performance in traditional single-component systems. During the post-printing processing, dehydration is triggered by heating. The released water molecules react with some isocyanate groups in the system, generating a highly active diamine chain extender in situ, which then undergoes a highly efficient chain extension reaction with the remaining isocyanate. This unique "one-step" endogenous chain extension mechanism not only fundamentally ensures the excellent single-component stability of the resin during storage and printing, avoiding the risk of prepolymer gelation, but more importantly, it significantly improves the mechanical strength and toughness of the cured elastomer material by forming a denser and more robust chemical network. This invention successfully achieves a perfect balance between convenient storage and high-performance products, opening up a new technical path for preparing high-performance, structurally complex 3D printed flexible products. Attached Figure Description

[0037] Figure 1The NMR spectrum of the methacrylate-terminated polyurethane prepolymer prepared in Example 1 of this invention is shown below.

[0038] Figure 2 The tensile strength curve of the elastomer material prepared in Example 1 of this invention;

[0039] Figure 3 The tensile strength curve of the elastomer material prepared in Example 2 of this invention;

[0040] Figure 4 The tensile strength curve of the elastomer material prepared in Example 3 of this invention;

[0041] Figure 5 The tensile strength curve of the elastomer material prepared in Comparative Example 1 of this invention;

[0042] Figure 6 These are the viscosity change curves of the photosensitive resin in Examples 1-3 of this invention;

[0043] Figure 7 The viscosity change curve of the photosensitive resin in Comparative Example 1 of this invention is shown. Detailed Implementation

[0044] This invention provides a single-component, dual-curing photosensitive resin for 3D printing that incorporates a "latent" reaction source, comprising the following raw materials by weight:

[0045] 70-90 parts of methacrylate-terminated polyurethane prepolymer

[0046] 1-5 parts of a compound that can be dehydrated under heating conditions

[0047] 5-15 parts of reactive diluent

[0048] 1-5 parts of photoinitiator

[0049] The structural formula of the methacrylate-terminated polyurethane prepolymer is shown in Formula II:

[0050] Formula II

[0051] In Equation II, m = 5~10; R1 is , , R2 is , .

[0052] According to the present invention, the dehydrating compound under heating conditions refers to a dehydrating crystalline hydrate, hydroxide, or molecular sieve under heating conditions, wherein the heating conditions are preferably 120~150℃; the dehydrating crystalline hydrate is preferably copper sulfate pentahydrate CuSO4·5H2O, calcium chloride dihydrate CaCl2·2H2O, or magnesium sulfate heptahydrate MgSO4·7H2O; the hydroxide is preferably magnesium hydroxide Mg(OH)2 or aluminum hydroxide Al(OH)3; and the molecular sieve is preferably 4A molecular sieve activated powder.

[0053] This invention also provides a method for preparing the above-mentioned single-component dual-curing 3D printing photosensitive resin combined with a "latent" reaction source, comprising:

[0054] Step 1: Under nitrogen protection, diisocyanate, glycol, dibutyltin dilaurate catalyst (DBTDL), and N,N-dimethylformamide (DMF) solvent are sequentially added to a reaction vessel. The reaction system is then preferably heated to 60-80°C and reacted for 2-4 hours under constant stirring to synthesize an isocyanate-terminated polyurethane prepolymer. The glycol is preferably polyethylene glycol, polypropylene glycol, or polytetrahydrofuran glycol; the diisocyanate is preferably isophorone diisocyanate or hexamethylene diisocyanate; the molar ratio of glycol to diisocyanate is preferably 1:(1.5-2.5); the amount of dibutyltin dilaurate catalyst is preferably 0.1wt%-1wt% of the total mass of glycol and diisocyanate. The reaction process is as follows:

[0055]

[0056] Step 2: Under nitrogen protection, the isocyanate-terminated polyurethane prepolymer obtained in Step 1 is placed in a container with tert-butylaminoethyl methacrylate (TBAEMA) and the solvent N,N-dimethylformamide (DMF). Preferably, the reaction system is heated to 65-85°C and the reaction is continued for 4-6 hours. After the reaction is complete, the product is poured into n-hexane to precipitate. The obtained solid is collected, filtered, and washed repeatedly with n-hexane 3-5 times. Finally, it is dried to obtain the methacrylate-terminated polyurethane prepolymer. The preferred molar ratio of isocyanate groups to tert-butylaminoethyl methacrylate in the isocyanate-terminated oligomer is 1:(1-1.1). The reaction process is as follows:

[0057]

[0058] Step 3: The methacrylate-terminated polyurethane prepolymer obtained in Step 2 is uniformly mixed with a dehydrating compound under heating conditions, an active diluent, and a photoinitiator at room temperature to prepare a one-component photosensitive resin. The active diluent is preferably dipropylene glycol diacrylate, and the photoinitiator is preferably diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxychloride; the preferred mass ratio of the methacrylate-terminated polyurethane prepolymer, hydrated polyurethane or hydroxide, molecular sieve, active diluent, and photoinitiator is (70~90):(1~5):(5~15):(1~5).

[0059] The present invention also provides an elastomer material comprising the above-described single-component dual-curing 3D printing photosensitive resin incorporating a "latent" reaction source.

[0060] This invention also provides a method for preparing the above-mentioned elastomer material, comprising:

[0061] Step 1: Inject the photosensitive resin into the material tank of the photopolymer 3D printer, and then cure it layer by layer under ultraviolet light at a wavelength of 405nm to obtain the photopolymer product. The reaction process is as follows:

[0062]

[0063] Step 2: Place the obtained photocured product in an oven and allow it to undergo a programmed temperature rise process to fully carry out the thermocuring reaction. The preferred programmed temperature rise process has an initial temperature of 80-100℃ and a final temperature of 120-150℃, lasting 8-12 hours. During the thermocuring stage, the sterically hindered urea bonds formed by tert-butylaminoethyl methacrylate (TBAEMA) and isocyanate partially dissociate under heating conditions, regenerating isocyanate-terminated prepolymers (reaction a). Simultaneously, the crystalline hydrates, hydroxides, or molecular sieves in the system release water molecules at high temperatures (reaction b). These water molecules further react with some of the isocyanate-terminated prepolymers to generate diamine-terminated prepolymers (reaction c). Subsequently, the newly generated diamine-terminated prepolymers can rapidly undergo a chain extension reaction with the isocyanate-terminated prepolymers in the system that have not yet reacted with water (reaction d), ultimately forming a stable elastomer material (3D printed product).

[0064] The reaction process is as follows:

[0065] Reaction a:

[0066]

[0067] Reaction b:

[0068]

[0069]

[0070]

[0071] Reaction c:

[0072]

[0073] Reaction d:

[0074]

[0075] The present invention will be further described in detail below with reference to specific embodiments. All raw materials involved in the embodiments are commercially available.

[0076] Example 1

[0077] 1) Under ambient temperature and nitrogen protection, isophorone diisocyanate (15 mmol, 3.33 g), polypropylene glycol (Mn=2000) (10 mmol, 20.00 g), dibutyltin dilaurate catalyst (DBTDL) (0.12 g), and N,N-dimethylformamide (DMF) solvent (17 mL) were sequentially added to a three-necked flask equipped with a mechanical stirrer, thermometer, and reflux condenser. The reaction system was then heated to 60 °C and reacted under constant stirring for 2 hours to synthesize isocyanate-terminated oligomers.

[0078] 2) The isocyanate-terminated oligomer obtained above (10 mmol, 25.20 g) was placed in a three-necked flask equipped with a mechanical stirrer, thermometer, and condenser with tert-butylaminoethyl methacrylate (TBAEMA) (20 mmol, 3.70 g) and N,N-dimethylformamide (DMF) solvent (50 mL). Under a nitrogen atmosphere, the reaction system was heated to 65 °C and reacted for 4 hours. After the reaction was completed, the product was poured into n-hexane to precipitate. The obtained solid was collected, filtered, washed repeatedly with n-hexane 3–5 times, and finally dried to obtain the methacrylate-terminated polyurethane prepolymer. Figure 1 The image shows the 1H NMR spectrum of the methacrylate-terminated polyurethane prepolymer prepared in Example 1. As can be seen from the image, each H has a corresponding assignment, proving that the chemical structure was successfully prepared.

[0079] 3) The obtained methacrylate-terminated polyurethane prepolymer (80g) was mixed with 4A molecular sieve activating powder (4.00g), reactive diluent dipropylene glycol dimethacrylate (15.00g), and photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) (1.00g) at room temperature to prepare a one-component photosensitive resin.

[0080] 4) Subsequently, the photosensitive resin is injected into the material tank of the photocurable 3D printer and photocured layer by layer under ultraviolet light with a wavelength of 405nm to obtain the photocured product.

[0081] 5) Place the obtained photocured product in an oven, preheat at 100℃ for 2 hours, then raise the temperature to 120℃ and heat-treat for 8 hours to fully carry out the thermocuring reaction. During the thermocuring stage, the sterically hindered urea bonds formed by tert-butylaminoethyl methacrylate (TBAEMA) and isocyanate partially dissociate under heating conditions, regenerating isocyanate-terminated prepolymers. Simultaneously, the crystalline hydrates, hydroxides, or molecular sieves in the system release water molecules at high temperatures. These water molecules further react with some of the isocyanate-terminated prepolymers to generate diamine-terminated prepolymers. Subsequently, the newly generated diamine-terminated prepolymers can rapidly undergo chain extension reactions with the isocyanate-terminated prepolymers in the system that have not yet reacted with water, ultimately forming a stable 3D printed product.

[0082] The tensile strength curve of the 3D printed product prepared in Example 1 is shown below. Figure 2 As shown, the tensile strength is 29 MPa and the elongation at break is 706%. This is because a unique "microphase separation" structure is constructed in situ through a "latent" reaction. This structure combines rigid and flexible segments and forms reversible physical cross-linking points, thus endowing the material with extremely high elasticity.

[0083] Example 2

[0084] 1) Under ambient temperature and nitrogen protection, isophorone diisocyanate (20 mmol, 4.44 g), polypropylene glycol (Mn=2000) (10 mmol, 20.00 g), dibutyltin dilaurate catalyst (DBTDL) (0.12 g), and N,N-dimethylformamide (DMF) solvent (18 mL) were sequentially added to a three-necked flask equipped with a mechanical stirrer, thermometer, and reflux condenser. The reaction system was then heated to 70 °C and reacted under constant stirring for 4 hours to synthesize isocyanate-terminated oligomers.

[0085] 2) The isocyanate-terminated oligomer obtained above (10 mmol, 25.20 g) was placed in a three-necked flask equipped with a mechanical stirrer, thermometer, and condenser with tert-butylaminoethyl methacrylate (TBAEMA) (20 mmol, 3.70 g) and N,N-dimethylformamide (DMF) solvent (50 mL). Under a nitrogen atmosphere, the reaction system was heated to 65 °C and reacted for 4 hours. After the reaction was completed, the product was poured into n-hexane to precipitate. The obtained solid was collected, filtered, washed repeatedly with n-hexane 3–5 times, and finally dried to obtain the methacrylate-terminated polyurethane prepolymer.

[0086] 3) The obtained methacrylate-terminated polyurethane prepolymer (85g) was mixed with magnesium sulfate heptahydrate MgSO4·7H2O (2.00g), reactive diluent dipropylene glycol dimethacrylate (12.00g), and photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) (1.00g) at room temperature to prepare a one-component photosensitive resin.

[0087] 4) Subsequently, the photosensitive resin is injected into the material tank of the photocurable 3D printer and photocured layer by layer under ultraviolet light with a wavelength of 405nm to obtain the photocured product.

[0088] 5) Place the obtained photocured product in an oven, preheat it to 80°C for 2 hours, then raise the temperature to 120°C and heat treat it for 8 hours to fully carry out the thermocuring reaction and finally form a stable 3D printed product.

[0089] The tensile strength curve of the 3D printed product prepared in Example 2 is shown below. Figure 3 As shown, the tensile strength is 22 MPa and the elongation at break is 669%.

[0090] Example 3

[0091] 1) Under ambient temperature and nitrogen protection, isophorone diisocyanate (25 mmol, 5.55 g), polypropylene glycol (Mn=2000) (10 mmol, 20.00 g), dibutyltin dilaurate catalyst (DBTDL) (0.13 g), and N,N-dimethylformamide (DMF) solvent (20 mL) were sequentially added to a three-necked flask equipped with a mechanical stirrer, thermometer, and reflux condenser. The reaction system was then heated to 80 °C and reacted under constant stirring for 4 hours to synthesize isocyanate-terminated oligomers.

[0092] 2) The isocyanate-terminated oligomer obtained above (10 mmol, 25.20 g) was placed in a three-necked flask equipped with a mechanical stirrer, thermometer, and condenser with tert-butylaminoethyl methacrylate (TBAEMA) (20 mmol, 3.70 g) and N,N-dimethylformamide (DMF) solvent (50 mL). Under a nitrogen atmosphere, the reaction system was heated to 65 °C and reacted for 4 hours. After the reaction was completed, the product was poured into n-hexane to precipitate. The obtained solid was collected, filtered, washed repeatedly with n-hexane 3–5 times, and finally dried to obtain the methacrylate-terminated polyurethane prepolymer.

[0093] 3) The obtained methacrylate-terminated polyurethane prepolymer (80g) was mixed with aluminum hydroxide Al(OH)3 (3.50g), reactive diluent dipropylene glycol dimethacrylate (15.00g), and photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) (1.50g) at room temperature to prepare a one-component photosensitive resin.

[0094] 4) Subsequently, the photosensitive resin is injected into the material tank of the photocurable 3D printer and photocured layer by layer under ultraviolet light with a wavelength of 405nm to obtain the photocured product.

[0095] 5) Place the obtained photocured product in an oven, preheat it to 100°C for 2 hours, then raise the temperature to 150°C and heat treat it for 8 hours to fully carry out the thermocuring reaction and finally form a stable 3D printed product.

[0096] The tensile strength curve of the 3D printed product prepared in Example 3 is shown below. Figure 4 As shown, the tensile strength is 26 MPa and the elongation at break is 695%.

[0097] Comparative Example 1

[0098] 1) Under ambient temperature and nitrogen protection, isophorone diisocyanate (15 mmol, 3.33 g), polypropylene glycol (Mn=2000) (10 mmol, 20.00 g), dibutyltin dilaurate catalyst (DBTDL) (0.12 g), and N,N-dimethylformamide (DMF) solvent (17 mL) were sequentially added to a three-necked flask equipped with a mechanical stirrer, thermometer, and reflux condenser. The reaction system was then heated to 60 °C and reacted under constant stirring for 2 hours to synthesize isocyanate-terminated oligomers.

[0099] 2) The isocyanate-terminated oligomer obtained above (10 mmol, 25.20 g) was placed in a three-necked flask equipped with a mechanical stirrer, thermometer, and condenser with tert-butylaminoethyl methacrylate (TBAEMA) (20 mmol, 3.70 g) and N,N-dimethylformamide (DMF) solvent (50 mL). Under a nitrogen atmosphere, the reaction system was heated to 65 °C and reacted for 4 hours. After the reaction was completed, the product was poured into n-hexane to precipitate. The obtained solid was collected, filtered, washed repeatedly with n-hexane 3–5 times, and finally dried to obtain the methacrylate-terminated polyurethane prepolymer.

[0100] 3) The obtained methacrylate-terminated polyurethane prepolymer (85g), along with the reactive diluent dipropylene glycol dimethacrylate (12.00g), deionized water (2.00g), and photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) (1.00g), were mixed at room temperature to prepare a one-component photosensitive resin.

[0101] 4) Subsequently, the photosensitive resin is injected into the material tank of the photocurable 3D printer and photocured layer by layer under ultraviolet light with a wavelength of 405nm to obtain the photocured product.

[0102] 5) Place the obtained photocured product in an oven, preheat it to 100°C for 2 hours, then raise the temperature to 120°C and heat treat it for 8 hours to fully carry out the thermocuring reaction and finally form a stable 3D printed product.

[0103] The tensile strength curve of the 3D printed product prepared in Comparative Example 1 is shown below. Figure 5 As shown, the tensile strength is 4 MPa and the elongation at break is 93%. During the heating process, the evaporation of moisture leads to insufficient moisture content, resulting in incomplete chain extension reaction and thus failing to improve the mechanical properties of the material.

[0104] Figure 6 These are the viscosity change curves of the photosensitive resin in Examples 1-3 of the present invention. Figure 7 The figure shows the viscosity change curve of the photosensitive resin in Comparative Example 1 of this invention. It can be seen that the viscosity of Comparative Example 1 increases rapidly within 7 days, eventually becoming a solidified state, while the viscosity of the product obtained in the embodiment of this invention only increases slightly after 28 days and can still be used for printing, proving that the single-component 3D printing photosensitive resin of this invention has good stability.

Claims

1. A single component dual cure 3D printing photoreactive resin incorporating a "latent" reactive source, characterized in that, By mass parts, including the following raw materials: Methyl methacrylate-terminated polyurethane prepolymer 70~90 parts Compound dehydratable under heating conditions 1~5 parts Active diluent 5~15 parts Photoinitiator 1~5 parts The structural formula of the methyl methacrylate-terminated polyurethane prepolymer is shown as formula II: Formula II, m = 5-10; R1is , , R2is , .

2. A single-part dual-cure 3D printing photoreactive resin incorporating a "latent" reactive source according to claim 1, characterized in that, The compound dehydratable under heating conditions is a crystalline hydrate, a hydroxide or a water-adsorbing molecular sieve dehydratable under heating conditions.

3. A single-part dual-cure 3D printing photoreactive resin incorporating a "latent" reactive source according to claim 2, characterized in that, The crystalline hydrate dehydratable under heating conditions is copper sulfate pentahydrate CuSO4·5H2O, calcium chloride dihydrate CaCl2·2H2O or magnesium sulfate heptahydrate MgSO4·7H2O, and the hydroxide is magnesium hydroxide Mg(OH)2 or aluminum hydroxide Al(OH)3.

4. The process for the preparation of a single component dual cure 3D printing photo- sensitive resin in combination with "latent" reactive source as claimed in claim 1, wherein, It comprises: Step one: under the protection of nitrogen, diisocyanate, diol, catalyst dibutyltin dilaurate and solvent N,N-dimethylformamide are sequentially added to the reaction container for reaction to obtain the isocyanate-terminated oligomer shown in formula I; Formula I, In formula I, m = 5-10, R1 is , , R2 is , ; Step two: under the protection of nitrogen atmosphere, the isocyanate-terminated oligomer prepared in step one is placed in a reaction container with tert-butyl aminoethyl methacrylate and solvent N,N-dimethylformamide for reaction to obtain the methyl methacrylate-terminated polyurethane prepolymer shown in formula II; Formula II, In formula II, m = 5-10, R1 is , or R2 is or ; Step three: the methyl methacrylate-terminated polyurethane prepolymer obtained in step two, the compound dehydratable under heating conditions, the active diluent and the photoinitiator are uniformly mixed at room temperature to prepare a single-component photosensitive resin.

5. The process for the preparation of a single component dual cure 3D printing photore- s in resin in combination with "latent" reactive source according to claim 4, characterized in that, The molar ratio of isocyanate groups to tert-butyl aminoethyl methacrylate in the isocyanate-terminated oligomer in step two is 1: (1~1.1).

6. The process for the preparation of a single component dual cure 3D printing photosensitive resin in combination with "latent" reactive source as claimed in claim 4 wherein, The reaction temperature in step two is 65~85℃, and the reaction time is 4~6 hours.

7. The process for the preparation of a single component dual cure 3D printing photore- sin in combination with "latent" reactive source according to claim 4, characterized in that, The active diluent in step three is dipropylene glycol diacrylate, and the photoinitiator is diphenyl-(2,4,6-trimethylbenzoyl) phosphine oxide.

8. An elastomeric material characterized by, It comprises the single-component dual-curing 3D printing photosensitive resin combined with the "latent" reaction source according to claim 1.

9. The method of making an elastomeric material according to claim 8, wherein, It comprises: Step one: the photosensitive resin is injected into the trough of the light-curing 3D printer for light-curing molding to obtain a light-cured product comprising formula III; Formula III, In formula III, m = 5-10, R1is , or , R2is or ; Step two: the light-cured product obtained in step one is placed in an oven for programmed temperature heating and curing reaction to obtain an elastomer material comprising chemical structure formula IV; Formula IV, m = 5-10, n = 10-100, R1is , or R2is or .

10. The method of making an elastomeric material according to claim 9, wherein, The starting temperature of the programmed temperature heating and curing in step two is 80~100℃, the final heating temperature is 120~150℃, and the programmed temperature heating process lasts for 8~12 hours.

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