Photocurable resin, and preparation method therefor and use thereof

Abstract

The present application belongs to the technical field of photocuring 3D printing. Disclosed are a photocurable resin, and a preparation method therefor and the use thereof. The photocurable resin provided in the present application comprises a polyurethane acrylate oligomer, a modified acrylate oligomer, a reactive diluent, a photoinitiator, a light stabilizer and a dye, wherein the polyurethane acrylate oligomer can improve the toughness and reaction speed of the photocurable resin and reduce the volume shrinkage of the photocurable resin; the modified acrylate oligomer can improve the durability of the photocurable resin, adjust the hardness and toughness, and also reduce the volume shrinkage of the photocurable resin; and the reactive diluent can improve the hardness and toughness of the photocurable resin. The compounding of the polyurethane acrylate oligomer, the modified acrylate oligomer and the reactive diluent is used, and the amount of each component is defined, such that each component fully exerts a synergistic effect, and the photocurable resin maintains high toughness and durability while having a relatively low volume shrinkage and a relatively high hardness.

Description

UV-curable resins, preparation methods and applications

[0001] This disclosure is based on and claims priority to Chinese Patent Application No. 202411508143.3, filed on October 25, 2024, entitled "Photocurable Resin, Preparation Method and Application", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of photocurable 3D printing technology, and in particular to a photocurable resin, its preparation method, and its application. Background Technology

[0003] Photopolymer 3D printing is a method of producing 3D products by curing a photopolymer resin layer by layer using ultraviolet light. The performance of the photopolymer resin, a crucial consumable in photopolymer 3D printing, directly impacts the product's performance. Different products have different performance requirements for the photopolymer resin. For example, dental materials require photopolymer resins to have low volume shrinkage, high hardness, while maintaining high toughness and durability. However, existing photopolymer resins cannot simultaneously meet these requirements. Therefore, it is necessary to provide a photopolymer resin for dental materials that can simultaneously satisfy these requirements. Summary of the Invention

[0004] This application provides a photocurable resin, its preparation method, and its application. The photocurable resin exhibits low shrinkage and high hardness while maintaining high toughness and durability, and can be applied to photocurable 3D printing dental materials. The technical solution is as follows:

[0005] On one hand, a photocurable resin is provided, the photocurable resin comprising the following components in parts by weight:

[0006] 40-65 parts of polyurethane acrylate oligomer, 10-20 parts of modified acrylate oligomer, 25-40 parts of reactive diluent, 1-5 parts of photoinitiator, 0.1-0.5 parts of light stabilizer, and 0.001-0.01 parts of dye.

[0007] In one possible implementation, the reactive diluent comprises 5 to 10 parts by weight of bisphenol A di(meth)acrylate and 20 to 30 parts by weight of a monofunctional or bifunctional monomer.

[0008] In another possible implementation, the monofunctional or difunctional monomer is selected from at least one of acrylamide morpholine, isobornyl acrylate, Sartoma SR420NS, Sartoma SR259NS, Changxing Chemical EM2104, Changxing Chemical EM2204, Changxing Chemical EM2251, Changxing Chemical EM328, and Rahn Chemical Genomer*1122.

[0009] In another possible implementation, the modified acrylate oligomer is selected from at least one of Elvacite4026, Changxing Chemical 6530B, Lankeluo L-6020, Lankeluo L-6040, and Runao Chemical FSP2902.

[0010] In another possible implementation, the polyurethane acrylate oligomer is a bifunctional polyurethane acrylate oligomer with a viscosity of 1000cps to 80000cps and a hardness range of 44D to 90D after curing.

[0011] In another possible implementation, the polyurethane acrylate oligomer is selected from at least one of Songda SD8976, Runao Chemical FSP8091, Runao Chemical CN1964NS, Rahn Chemical Genomer*4247, and Rahn Chemical Genomer*4256.

[0012] In another possible implementation, the photoinitiator is selected from at least one of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphine, 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0013] In another possible implementation, the light stabilizer is selected from at least one of Tinuvin 292, Tinuvin 770, and Omnistab 326.

[0014] On the other hand, a method for preparing a photocurable resin is provided, the method comprising:

[0015] Add reactive diluent and dye to the container according to the mass fractions of each component, and ultrasonically disperse for 20 to 30 minutes;

[0016] Continue adding photoinitiator and disperse at a speed of 600 r / min to 800 r / min for 30 min to 60 min;

[0017] Continue adding polyurethane acrylate oligomer, modified acrylate oligomer and light stabilizer, disperse at a speed of 600 r / min to 800 r / min for 45 min to 60 min, filter, let stand to defoam, and obtain the light-cured resin.

[0018] On the other hand, an application of photocurable resin in photocurable 3D printed dental materials is provided.

[0019] This application provides a photocurable resin comprising polyurethane acrylate oligomers, modified acrylate oligomers, reactive diluents, photoinitiators, light stabilizers, and dyes. The polyurethane acrylate oligomers improve the toughness and reaction rate of the photocurable resin and reduce its volume shrinkage. The modified acrylate oligomers improve the durability of the photocurable resin, regulate its hardness and toughness, and further reduce its volume shrinkage. The reactive diluent improves the hardness and toughness of the photocurable resin. By using a compound of polyurethane acrylate oligomers, modified acrylate oligomers, and reactive diluents, and limiting the amount of each component, the components can fully exert their synergistic effect, thereby enabling the photocurable resin to maintain high toughness and durability while exhibiting low volume shrinkage and high hardness. Furthermore, the photocurable resin also includes light stabilizers and dyes. The light stabilizers enhance the color stability of the photocurable resin during post-curing and photoaging conditions, while the dyes not only provide the desired color but also reduce the yellowing effect of the photocurable resin.

[0020] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this disclosure. Detailed Implementation

[0021] To make the technical solution and advantages of this application clearer, the embodiments of this application will be described in further detail below.

[0022] On one hand, embodiments of this application provide a photocurable resin, which comprises the following components in parts by weight:

[0023] 40-65 parts of polyurethane acrylate oligomer, 10-20 parts of modified acrylate oligomer, 25-40 parts of reactive diluent, 1-5 parts of photoinitiator, 0.1-0.5 parts of light stabilizer, and 0.001-0.01 parts of dye.

[0024] The mass fractions of the polyurethane acrylate oligomers can be 40, 42, 45, 48, 50, 52, 53, 55, 58, 60, 63, 65, etc., and the mass fractions of the modified acrylate oligomers can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc., and the mass fractions of the photoinitiator... The quantities can be 1, 2, 3, 4, or 5 parts, etc.; the quantities of light stabilizer can be 0.1, 0.2, 0.3, 0.4, or 0.5 parts, etc.; and the quantities of dye can be 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, or 0.01 parts, etc.

[0025] This application provides a photocurable resin comprising polyurethane acrylate oligomers, modified acrylate oligomers, reactive diluents, photoinitiators, light stabilizers, and dyes. The polyurethane acrylate oligomers improve the toughness and reaction rate of the photocurable resin and reduce its volume shrinkage. The modified acrylate oligomers improve the durability of the photocurable resin, regulate its hardness and toughness, and further reduce its volume shrinkage. The reactive diluent improves the hardness and toughness of the photocurable resin. By using a compound of polyurethane acrylate oligomers, modified acrylate oligomers, and reactive diluents, and limiting the amount of each component, the components can fully exert their synergistic effect, thereby enabling the photocurable resin to maintain high toughness and durability while exhibiting low volume shrinkage and high hardness. Furthermore, the photocurable resin also includes light stabilizers and dyes. The light stabilizers enhance the color stability of the photocurable resin during post-curing and photoaging conditions, while the dyes not only provide the desired color but also reduce the yellowing effect of the photocurable resin.

[0026] In one possible implementation, the reactive diluent comprises 5 to 10 parts by mass of bisphenol A di(meth)acrylate and 20 to 30 parts by mass of monofunctional or bifunctional monomers.

[0027] The mass fractions of bisphenol A di(meth)acrylate can be 5, 6, 7, 8, 9, 10, etc., and the mass fractions of monofunctional or difunctional monomers can be 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, etc.

[0028] In one possible implementation, bisphenol A di(meth)acrylate is selected from at least one of Changxing Chemical EM3260 (BPA2EODMA), Changxing Chemical EM3265 (BPA10EODMA), Changxing Chemical EM3262 (BPA2.6EODMA), Changxing Chemical EM3261-8 (BPA4EODMA), Changxing Chemical EM2261, Changxing Chemical EM2265, Changxing Chemical EM2266, Sartoma SR348NS, and Sartoma SR601NS.

[0029] In one possible implementation, the monofunctional or difunctional monomer is selected from at least one of acrylamide morpholine (ACMO), isobornyl acrylate (IBOA), Sartoma SR420NS (TMCHA), Sartoma SR259NS (polyethylene glycol (200) diacrylate), Changxing Chemical EM2104 (TMCHA), Changxing Chemical EM2204 (DCPDA), Changxing Chemical EM2251 (NPG2PDOA), Changxing Chemical EM328 (TEGDMA), and Rahn Chemical Genomer*1122.

[0030] Among them, ACMO, IBOA, Sartoma SR420NS, Changxing Chemical EM2104, Sartoma SR420NS, and Rahn Chemical Genomer*1122 are monofunctional monomers, while Sartoma SR259NS, Changxing Chemical EM2204, EM2251, and EM328 are difunctional monomers.

[0031] In the embodiments of this application, bisphenol A di(meth)acrylate is a type of monomer containing bisphenol A and ethoxylated to varying degrees. Due to its bisphenol A structure, this type of monomer exhibits high reactivity, fast reaction rate, high hardness, low skin irritation, good heat resistance, low odor, and low volatility. The functionality of the monomer directly affects the viscosity, curing speed, degree of curing, and toughness of the photocurable resin. High-functionality monomers can provide more reaction sites, thereby accelerating the curing process, increasing crosslinking density, and thus improving the hardness and strength of the photocurable resin. However, high-functionality monomers, due to excessively high crosslinking density, can cause the photocurable resin to harden, reduce elongation at break, and become prone to breakage. Simultaneously, high-functionality monomers typically have poor dilution ability, resulting in higher viscosity and poorer flowability of the system. Therefore, this application uses monofunctional or difunctional monomers, and combines monofunctional or difunctional monomers with bisphenol A di(meth)acrylate as an active diluent, and then combines them with other components. This can not only make the photocurable resin have a suitable viscosity, but also effectively improve the hardness and toughness of the photocurable resin.

[0032] In one possible implementation, the modified acrylate oligomer is selected from at least one of Elvacite 4026, Changxing Chemical 6530B, Lankeluo L-6020, Lankeluo L-6040, and Runao Chemical FSP2902.

[0033] In this implementation method, the modified acrylate oligomers such as Elvacite 4026, Changxing Chemical 6530B, Lankeluo L-6020, Lankeluo L-6040, and Runao Chemical FSP2902 are all acrylate oligomers modified with UV reactive functional groups. When using these modified acrylate oligomers, if the viscosity is in the range of 10,000 cps to 30,000 cps, no dilution is required. If the viscosity is too high, exceeding the above range, an active diluent such as 4-acryloylmorpholine (ACMO), 3,3,5-trimethylcyclohexyl acrylate (TMCHA), or 1,6-hexanediol diacrylate (HDDA) can be used to pre-dilute the modified acrylate oligomers to a viscosity of 10,000 cps to 30,000 cps.

[0034] It should be noted that the reactive diluent mentioned here is the reactive diluent used to dilute the viscosity of the modified acrylate oligomer before preparing the photocurable resin, and is not the reactive diluent in the formulation.

[0035] Conventional acrylate resins possess advantages such as high flexibility, water resistance, yellowing resistance, and excellent tear resistance, but they lack reactive functional groups and have extremely high viscosity, making them difficult to apply in photopolymerization 3D printing. This application utilizes a special acrylate modified with UV reactive functional groups. Photoinitiating activity is introduced by modifying the acrylate backbone, and monomer pre-dissolution reduces the viscosity, enabling its application in photopolymerization 3D printing.

[0036] This application uses modified acrylate oligomers within the above viscosity range to blend with other components, which can give the photocurable resin suitable viscosity and curing speed, as well as high hardness, flexibility, durability and low volume shrinkage.

[0037] In one possible implementation, the polyurethane acrylate oligomer is selected from at least one of Songda SD8976, Runao Chemical FSP8091, Runao Chemical CN1964NS, Rahn Chemical Genomer*4247, and Rahn Chemical Genomer*4256.

[0038] In this implementation, the aforementioned polyurethane acrylate oligomers are all bifunctional polyurethane acrylate oligomers with a room temperature viscosity of 1000 cps to 80000 cps and a hardness range of 44D to 90D after curing. Among them, Rahn Chemical's Genomer*4247 and Genomer*4256 are aliphatic polyurethane methacrylates.

[0039] The viscosity, functionality, and hardness of polyurethane acrylate oligomers directly affect the performance of UV-curable resins. Excessive hardness typically results in poor elongation and toughness, while insufficient hardness leads to poor shape retention, both limiting their applications. Polyurethane acrylate oligomers within the aforementioned hardness range exhibit moderate hardness, which can be adjusted by adding other components to meet usage requirements. The viscosity and functionality of polyurethane acrylate oligomers also affect the curing speed and other properties of UV-curable resins. For example, the level of functionality determines the length of the polymer molecular chain and the crosslinking density, thus affecting the mechanical properties of the UV-curable resin. Simultaneously, the level of functionality also affects the tensile strength, tensile modulus of elasticity, and elongation at break of the UV-curable resin, thereby impacting its durability. Excessively high resin viscosity necessitates the addition of large amounts of reactive diluents, leading to reduced mechanical properties and significant volume shrinkage.

[0040] This application uses a bifunctional polyurethane acrylate oligomer within the above-mentioned hardness and viscosity range after curing, combined with other components, which can give the photocurable resin a suitable curing speed, as well as high hardness, flexibility, durability and low volume shrinkage.

[0041] In one possible implementation, the photoinitiator is selected from at least one of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator TPO), ethyl 2,4,6-trimethylbenzoylphenylphosphonate (photoinitiator TPO-L), 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide (photoinitiator TMO), and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator 819).

[0042] Photoinitiators can generate free radicals under ultraviolet or visible light irradiation, which can initiate polymerization reactions of double bonds.

[0043] In one possible implementation, the light stabilizer is selected from at least one of Tinuvin 292, Tinuvin 770, and Omnistab 326.

[0044] In the embodiments of this application, the above-mentioned light stabilizer can enhance the color stability of the photocurable resin during the post-curing process and under photoaging conditions.

[0045] In one possible implementation, the dye is selected from blue dyes, such as at least one of elusive crystal violet, ultramarine, and blue dyes.

[0046] In the embodiments of this application, the above-mentioned dye can not only provide the required color for the photocurable resin, but also effectively reduce the yellowing effect of the photocurable resin.

[0047] On the other hand, embodiments of this application provide a method for preparing a photocurable resin, the method comprising:

[0048] Step 1: Add reactive diluent and dye to the container according to the mass fractions of each component, and disperse using ultrasonication.

[0049] Add bisphenol A di(meth)acrylate, monofunctional or bifunctional monomers and dyes to the tank, and ultrasonically disperse for 20-30 minutes. After dissolution, proceed to the next step.

[0050] The ultrasonic dispersion time can be 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, 30 min, etc.

[0051] Step 2: Continue adding photoinitiator and disperse at a speed of 600 r / min to 800 r / min for 30 min to 60 min.

[0052] Continue adding photoinitiator to the tank and disperse it using a high-speed disperser at a speed of 600 r / min to 800 r / min for 30 min to 60 min.

[0053] The rotational speed can be 600 r / min, 650 r / min, 680 r / min, 700 r / min, 750 r / min, 780 r / min, 800 r / min, etc., and the dispersion time can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, etc.

[0054] Step 3: Continue to add polyurethane acrylate oligomer, modified acrylate oligomer and light stabilizer, disperse at a speed of 600 r / min to 800 r / min for 45 min to 60 min, filter, let stand to defoam, and obtain light-cured resin.

[0055] The rotation speed in this step can be 600 r / min, 650 r / min, 680 r / min, 700 r / min, 750 r / min, 780 r / min, 800 r / min, etc., and the dispersion time can be 45 min, 48 min, 50 min, 52 min, 55 min, 56 min, 58 min, 60 min, etc.

[0056] The photocurable resin prepared in this application is a compound of polyurethane acrylate oligomers, modified acrylate oligomers, and reactive diluents, with limited dosage of each component. The components fully exert their synergistic effect, thereby enabling the photocurable resin to maintain high toughness and durability while exhibiting low volume shrinkage and high hardness. Furthermore, the photocurable resin also includes light stabilizers and dyes. The light stabilizers enhance the color stability of the photocurable resin during post-curing and photoaging conditions, while the dyes not only provide the desired color but also reduce the yellowing effect of the photocurable resin.

[0057] On the other hand, this application also provides an application of photocurable resin in photocurable 3D printed dental materials.

[0058] Among them, dental materials can be orthodontic materials or other dental materials, without specific limitations.

[0059] To make the technical solution and advantages of this application clearer, they will be described in detail below through specific embodiments.

[0060] In the following specific embodiments, operations without specified conditions are performed under standard conditions or conditions recommended by the manufacturer. Raw materials without specified manufacturers and specifications are all commercially available products.

[0061] Among them, the polyurethane acrylate oligomers were selected from Songda SD8976, Runao Chemical FSP8091, Rahn Chemical Genomer*4247, and Runao Chemical CN1964NS.

[0062] The modified acrylate oligomer was selected from Runao Chemical's FSP2902;

[0063] Bisphenol A di(meth)acrylate is selected from Changxing Chemical EM3261-8;

[0064] Monofunctional or difunctional monomers were selected from ACMO, Changxing Chemical EM2104, and EM2251;

[0065] The photoinitiator is selected from TPO, TMO, and TPO-L;

[0066] The light stabilizer was selected from Tinuvin 292;

[0067] The dye was selected from ultramarine.

[0068] Example 1

[0069] Example 1 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of ACMO, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of photoinitiator TPO are added and dispersed evenly; 53 parts by weight of CN1964NS, 20 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0070] Example 2

[0071] Example 2 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of photoinitiator TPO are added and dispersed evenly; 63 parts by weight of FSP8091, 10 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0072] Example 3

[0073] Example 3 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of ACMO, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of photoinitiator TPO are added and dispersed evenly; 53 parts by weight of FSP8091, 20 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0074] Example 4

[0075] Example 4 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of photoinitiator TMO are added and dispersed evenly; 48 parts by weight of SD8976, 15 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0076] Example 5

[0077] Example 5 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of photoinitiator TMO are added and dispersed evenly; 53 parts by weight of SD8976, 10 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0078] Example 6

[0079] Example 6 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2251, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of TPO-L are added and dispersed evenly; 53 parts by weight of Genomer*4247, 10 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0080] Example 7

[0081] Example 7 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of photoinitiator TMO are added and dispersed evenly; 30 parts by weight of SD8976, 33 parts by weight of FSP8091, 10 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0082] Comparative Example 1

[0083] Comparative Example 1 provides a photocurable resin, which is prepared by the following method: 22 parts by mass of ACMO, 5 parts by mass of EM3261-8 and 0.004 parts by mass of ultramarine are added to a container and ultrasonically dispersed; 3 parts by mass of photoinitiator TPO are added and dispersed evenly; 53 parts by mass of Genomer*4247, 20 parts by mass of FSP2902 and 0.4 parts by mass of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0084] Comparative Example 2

[0085] Comparative Example 2 provides a photocurable resin, which is prepared by the following method: 22 parts by mass of ACMO, 5 parts by mass of EM3261-8 and 0.004 parts by mass of ultramarine are added to a container and ultrasonically dispersed; 3 parts by mass of photoinitiator TPO are added and dispersed evenly; 63 parts by mass of FSP8091, 10 parts by mass of FSP2902 and 0.4 parts by mass of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0086] Comparative Example 3

[0087] Comparative Example 3 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of photoinitiator TMO are added and dispersed evenly; 58 parts by weight of SD8976, 5 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0088] Comparative Example 4

[0089] Comparative Example 4 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of photoinitiator TPO are added and dispersed evenly; 53 parts by weight of SD8976, 10 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0090] Comparative Example 5

[0091] Comparative Example 5 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of TMO are added and dispersed evenly; 40 parts by weight of SD8976, 23 parts by weight of FSP8091, 10 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0092] Comparative Example 6

[0093] Comparative Example 6 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of TMO are added and dispersed evenly; 20 parts by weight of SD8976, 43 parts by weight of FSP8091, 10 parts by weight of FSP2902 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0094] Comparative Example 7

[0095] Comparative Example 7 provides a photocurable resin, which is prepared by the following method: 22 parts by weight of EM2104, 5 parts by weight of EM3261-8 and 0.004 parts by weight of ultramarine are added to a container and ultrasonically dispersed; 3 parts by weight of TMO are added and dispersed evenly; 63 parts by weight of SD8976 and 0.4 parts by weight of Tinuvin 292 are added and dispersed evenly; after filtration and standing to defoam, the photocurable resin is obtained.

[0096] The formulations of Examples 1 to 7 above can be found in Table 1 below, and the formulations of Comparative Examples 1 to 7 can be found in Table 2 below.

[0097] Table 1

[0098] Table 2

[0099] Application Examples

[0100] The photocurable resins prepared in Examples 1-7 and Comparative Examples 1-7 were used for 3D printing. A DLP 3D printer with a wavelength of 405 nm and a light intensity of 1 mW·cm was selected. -1 ~5mW·cm -1 The printing thickness of each layer is set to 100μm, and the printing time for a single layer is 5s to 10s.

[0101] Test methods: The appearance of the printed product was judged visually; no obvious yellowing and clear details were considered acceptable. Mechanical properties such as modulus and tensile elongation were tested using a tensile testing machine. The sample strip was approximately 15mm wide and 120μm thick. Curing degree was tested using an infrared spectrometer. The printed sample was cut with a knife, and the cross-section was scanned with infrared light. The curing degree was calculated by comparing the double bond ratio in the liquid state with that in the cured film. The bending durability of the printed sample was tested using a mechanical reciprocating structure. Test results are shown in Table 3 below.

[0102] Table 3

[0103] Comparing Examples 1, 3, and Comparative Example 1, the difference lies in the different polyurethane acrylate oligomers used to assess the influence of resins with different properties on the performance of the printed samples. Table 3 shows that the printed samples from Examples 1, 3, and Comparative Example 1 exhibit significant differences in performance, particularly in mechanical modulus, bending cycles, and tensile elongation.

[0104] Comparing Example 2 with Comparative Example 2, the difference lies in the different monomers. As can be seen from Table 3, when ACMO is used as the monomer, the sample has a faster curing rate and a higher degree of curing.

[0105] Comparing Examples 4 and 5 with Comparative Example 3, the difference lies in the different ratios of polyurethane acrylate oligomer (SD8976) and modified acrylate oligomer (FSP2902). As shown in Table 3, different ratios of polyurethane acrylate oligomer (SD8976) and modified acrylate oligomer (FSP2902) result in significant differences in mechanical properties such as modulus, tensile elongation, and hardness. In particular, the amount of modified acrylate oligomer (FSP2902) significantly affects the overall hardness and tensile elongation of the system.

[0106] Comparing Examples 5 and 6 with Comparative Example 4, the difference lies in the photoinitiator. Example 5 uses TMO as the photoinitiator, Example 6 uses TPO-L as the photoinitiator, and Comparative Example 4 uses TPO as the photoinitiator. As can be seen from Table 3, the sample corresponding to Example 5 has a higher degree of curing. This indicates that compared with TPO and TPO-L, the sample using TMO as the photoinitiator has a higher degree of curing.

[0107] Comparing Example 7 with Comparative Examples 5 and 6, the difference lies in the use of TMO as the photoinitiator. While keeping other components unchanged, SD8976 and FSP8091 were combined as a polyurethane acrylate oligomer. The differences in mechanical properties, degree of cure, and number of bends were compared between samples with different compounding ratios. It can be seen that different ratios of SD8976 and FSP8091 as polyurethane acrylate oligomers have a certain impact on the mechanical properties, degree of cure, and number of bends of the samples.

[0108] Comparing Example 5 with Comparative Example 7, the difference is that Comparative Example 7 only used polyurethane acrylate oligomers without adding modified acrylate oligomers. As shown in Table 3, compared to Comparative Example 7, although the modulus and hardness of the sample decreased after adding modified acrylate oligomers in Example 5, the elongation and flexural strength were significantly improved. This demonstrates that the addition of modified acrylate oligomers is beneficial for improving the flexibility and durability of the sample.

[0109] In summary, by adjusting the polyurethane acrylate oligomers, modified acrylate oligomers, reactive diluents, and initiators, the mechanical properties of the samples, such as mechanical modulus and tensile elongation, can be simultaneously improved, further meeting the application requirements of dental materials. Due to the reproductive toxicity issues of the photoinitiator TPO, it is listed on the EU REACH list, limiting its application. Therefore, a bottom-side cure test of TMO was introduced to compare the curing degree of samples with different photoinitiators. The results show that, for the same amount, the cure degree of samples with photoinitiator TMO is higher than that of traditional photoinitiators such as TPO and TPO-L.

[0110] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application, and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A photocurable resin, wherein, The photocurable resin comprises the following components in parts by weight: 40-65 parts of polyurethane acrylate oligomer, 10-20 parts of modified acrylate oligomer, 25-40 parts of reactive diluent, 1-5 parts of photoinitiator, 0.1-0.5 parts of light stabilizer, and 0.001-0.01 parts of dye.

2. The photocurable resin according to claim 1, wherein, The reactive diluent comprises 5 to 10 parts by weight of bisphenol A di(meth)acrylate and 20 to 30 parts by weight of monofunctional or bifunctional monomers.

3. The photocurable resin according to claim 2, wherein, The bisphenol A di(meth)acrylate is selected from at least one of Changxing Chemical EM3260, Changxing Chemical EM3265, Changxing Chemical EM3262, Changxing Chemical EM3261-8, Changxing Chemical EM2261, Changxing Chemical EM2265, Changxing Chemical EM2266, Sartoma SR348NS, and Sartoma SR601NS.

4. The photocurable resin according to claim 2, wherein, The monofunctional or difunctional monomer is selected from at least one of acrylamide morpholine, isobornyl acrylate, Sartoma SR420NS, Sartoma SR259NS, Changxing Chemical EM2104, Changxing Chemical EM2204, Changxing Chemical EM2251, Changxing Chemical EM328, and Rahn Chemical Genomer*1122.

5. The photocurable resin according to claim 1, wherein, The modified acrylate oligomer is selected from at least one of Elvacite 4026, Changxing Chemical 6530B, Lankeluo L-6020, Lankeluo L-6040, and Runao Chemical FSP2902.

6. The photocurable resin according to claim 1, wherein, The polyurethane acrylate oligomer is a bifunctional polyurethane acrylate oligomer with a viscosity of 1000cps to 80000cps and a hardness range of 44D to 90D after curing.

7. The photocurable resin according to claim 6, wherein, The polyurethane acrylate oligomer is selected from at least one of Songda SD8976, Runao Chemical FSP8091, Runao Chemical CN1964NS, Rahn Chemical Genomer*4247, and Rahn Chemical Genomer*4256.

8. The photocurable resin according to claim 1, wherein, The photoinitiator is selected from at least one of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphine, 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

9. A method for preparing a photocurable resin, wherein, The photocurable resin is as described in any one of claims 1 to 8, and the preparation method comprises: Add reactive diluent and dye to the container according to the mass fractions of each component, and ultrasonically disperse for 20 to 30 minutes; Continue adding photoinitiator and disperse at a speed of 600 r / min to 800 r / min for 30 min to 60 min; Continue adding polyurethane acrylate oligomer, modified acrylate oligomer and light stabilizer, disperse at a speed of 600 r / min to 800 r / min for 45 min to 60 min, filter, let stand to defoam, and obtain the light-cured resin.

10. The application of a photocurable resin in photocurable 3D printed dental materials, wherein, The photocurable resin is as described in any one of claims 1 to 8.

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