Photosensitive resin material for additive manufacturing and preparation method and product thereof

Abstract

The invention discloses a photosensitive resin material for additive manufacturing and a preparation method and a product thereof, the photosensitive resin material comprises a resin matrix composed of 30%-60% by mass of an acrylate oligomer, 20%-50% by mass of an active diluent and 1.5%-3% by mass of a photoinitiator, and a modified silicon-containing inorganic filler with a mass fraction of 13%-30%. Wherein the modified silicon-containing inorganic filler comprises silicon dioxide or silicate; the particle size of the modified silicon-containing inorganic filler is 0.1-30 [mu] m. After the photosensitive resin material is digitally sampled and subjected to 3D printing forming, the dimensional stability is kept under the high-temperature vacuum condition, and the die pressing success rate and the tooth socket precision are remarkably improved.

Description

Technical Field

[0001] The present application relates to the field of additive manufacturing materials, and in particular to a photosensitive resin material for additive manufacturing, a preparation method thereof, and products thereof. Background Art

[0002] In traditional orthodontic brace production, some manufacturers still use plaster as a negative mold. The specific process includes taking a patient's oral impression, casting a plaster model, and trimming the surface. The plaster model is placed in a molding machine, where a transparent film is heated and softened, and then vacuumed to fit the contours of the teeth, forming a suitable brace. Although plaster models are low-cost and easy to use, they have drawbacks such as low precision, a complex production process, and high dust levels in the production environment.

[0003] In recent years, dentists have increasingly conducted research on digital dental diagnosis and treatment. For example, Qin Changtao's "The Application Effect of Digital Dental Models in Practical Teaching of Orthodontic Models" compared digital models with traditional plaster models and concluded that the application of digital dental models in orthodontic model practice is effective, improves the accuracy of orthodontic models, and provides a new direction for orthodontic model practice.

[0004] With the popularization of digital technology, high-precision resin models have gradually replaced plaster models. However, the heat deformation temperature (HDT) of photosensitive resin is usually around 60-80°C, and the vacuum mold needs to be heated to above 100°C (such as the molding temperature of PETG film), which causes the resin model to soften and deform at high temperatures, affecting the fitting accuracy of the braces; at the same time, the low modulus of the resin will deform under vacuum pressure, and in severe cases, it will break, resulting in reduced braces accuracy or unusability, which is particularly serious when printing thin-walled parts. Therefore, the development of a model resin for 3D printing that can meet the application requirements of orthodontic molds has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0005] In view of the shortcomings of the related technologies mentioned above, the purpose of this application is to provide a photosensitive resin material for additive manufacturing, a preparation method, and products thereof, which are used to solve the problems of low modulus, easy softening and deformation at high temperatures, breakage and low precision of braces prepared with traditional photosensitive resins in the existing technology.

[0006] To achieve the above-mentioned objectives and other related objectives, the first aspect of the present application provides a photosensitive resin material for additive manufacturing, wherein the photosensitive resin material comprises: a resin matrix composed of an acrylate oligomer with a mass fraction of 30%-60%, an active diluent with a mass fraction of 20%-50%, and a photoinitiator with a mass fraction of 1.5%-3%, and a modified silicon-containing inorganic filler with a mass fraction of 13%-30%; wherein the modified silicon-containing inorganic filler comprises silicon dioxide or silicate; and the particle size of the modified silicon-containing inorganic filler is 0.1-30 μm.

[0007] In an embodiment of the first aspect, the acrylate oligomer includes one or more of polyester acrylate, polyether acrylate, polyurethane acrylate, and epoxy acrylate, and the resin functionality is 2-6.

[0008] In an embodiment of the first aspect, the reactive diluent includes one or more of acryloylmorpholine, isobornyl acrylate, isobornyl methacrylate, 4-tert-butylcyclohexyl acrylate, lauryl acrylate, cyclic trimethylolpropane formal acrylate, tricyclodecane dimethanol diacrylate, phenoxyethyl acrylate, tripropylene glycol diacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, ethylene glycol dimethacrylate, 1,9-nonanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-ethylene glycol diacrylate, and dipropylene glycol diacrylate.

[0009] In an embodiment of the first aspect, the mass fraction of the 4-tert-butylcyclohexyl acrylate is 20%-45%.

[0010] In an embodiment of the first aspect, the photoinitiator includes one or more of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO), 2,4,6-trimethylbenzoyl-di(p-tolyl) phosphine oxide (TMO), phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide (819), methyl benzoylformate (MBF), and camphorquinone (CQ).

[0011] In an embodiment of the first aspect, the mass fraction of the 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide is 1.5%-3%.

[0012] In an embodiment of the first aspect, the modified silicon-containing inorganic filler includes a silicon-containing inorganic filler and fumed silica with a mass fraction of 1.0%-5%.

[0013] In an embodiment of the first aspect, the fumed silica is fumed silica having a specific surface area of 120 m2 / g.

[0014] In an embodiment of the first aspect, the silicon-containing inorganic filler is surface-modified by using a silane coupling agent to prepare the modified silicon-containing inorganic filler.

[0015] In an embodiment of the first aspect, the modified silicon-containing inorganic filler is obtained by sequentially adding a silicon-containing inorganic filler and a silane coupling agent to an ethanol-water mixture, adjusting the pH value to 3.5-4 with dilute acid, and then drying.

[0016] In an embodiment of the first aspect, the ethanol-water mixture is formed by dispersing 20%-40% ethanol by mass and 60%-80% pure water by mass.

[0017] In an embodiment of the first aspect, the mass fraction of the silane coupling agent in the silicon-containing inorganic filler is 1%-5%.

[0018] In an embodiment of the first aspect, the silane coupling agent includes one of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS), or a mixture of the two.

[0019] The second aspect of the present application provides a method for preparing a photosensitive resin material for additive manufacturing, the preparation method comprising the following steps: at room temperature, adding 20%-50% by mass of a reactive diluent and 1.5%-3% by mass of a photoinitiator into a stirring kettle, and using a dispersing device to disperse at a speed of 500-1000 r / min for 30-60 minutes; adding 30%-60% by mass of an acrylate oligomer into the stirring kettle, and using the dispersing device to disperse at a speed of 500-1000 r / min; in speed and continue dispersing for 30-60 minutes to obtain a resin matrix; adding 13%-30% by mass of a modified silicon-containing inorganic filler to the resin matrix and continuing to disperse it using the dispersion equipment at a speed of 500-1000 r / min for 60-90 minutes; wherein the modified silicon-containing inorganic filler includes silicon dioxide or silicate; the particle size of the modified silicon-containing inorganic filler is 0.1-30 μm; after stirring, filtering with a 200-mesh filter cloth and the photosensitive resin material can be used for filling.

[0020] In an embodiment of the second aspect, the modified silicon-containing inorganic filler includes a silicon-containing inorganic filler and fumed silica with a mass fraction of 1.0%-5%.

[0021] In an embodiment of the second aspect, the fumed silica is fumed silica having a specific surface area of 120 m2 / g.

[0022] In an embodiment of the second aspect, the step of preparing a silicon-containing inorganic filler as a modified silicon-containing inorganic filler is further included: adding the silicon-containing inorganic filler to a pre-prepared modifying liquid and ultrasonically dispersing it for 10-25 minutes until the silicon-containing inorganic filler is uniformly suspended; adding a silane coupling agent according to 1%-5% of the mass of the silicon-containing inorganic filler, and then adding a diluted acetic acid solution to adjust the pH value to 3.5-4.0, using a dispersion equipment to stir the disperser at a speed of 800-1200 r / min for 30-90 minutes; after filtering, placing it in an 80°C oven for drying for 2 hours to obtain the modified silicon-containing inorganic filler.

[0023] In an embodiment of the second aspect, the modifying liquid is formed by mixing 20%-40% ethanol and 60%-80% pure water to form an ethanol-water dispersion.

[0024] In an embodiment of the second aspect, the mass fraction of the silane coupling agent in the silicon-containing inorganic filler is 1%-5%.

[0025] In an embodiment of the second aspect, the silane coupling agent includes one or a mixture of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS).

[0026] In a third aspect, the present application provides a resin product formed by curing the photosensitive resin material as described in the first aspect.

[0027] The fourth aspect of the present application provides a product made by 3D printing of the photosensitive resin material as described in the first aspect above.

[0028] In summary, the photosensitive resin material for additive manufacturing, its preparation method, and its products provided in this application achieve synergistic optimization of high HDT, high modulus, and high strength through composite modification of silicon-containing inorganic fillers; at the same time, it reduces the shrinkage of the photosensitive resin and improves printing accuracy. After digital sampling and 3D printing, the photosensitive resin material of this application maintains dimensional stability under high-temperature vacuum conditions, significantly improving the success rate of compression molding and the accuracy of braces. Therefore, it can be used specifically for the vacuum compression molding process of orthodontic braces. Compared with plaster models, it can greatly improve production efficiency and reduce personnel costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The specific features of the present application are set forth in the appended claims. The features and advantages of the present invention can be better understood by referring to the exemplary embodiments described in detail below and the accompanying drawings. A brief description of the drawings is as follows:

[0030] Figure 1 Shown is a flow chart of one embodiment of a method for preparing a photosensitive resin material for additive manufacturing of the present application.

[0031] Figure 2 Shown is a flow chart of another embodiment of the method for preparing the photosensitive resin material for additive manufacturing of the present application. DETAILED DESCRIPTION

[0032] The following describes the implementation of the present application through specific embodiments. People familiar with this technology can easily understand other advantages and effects of the present application from the contents disclosed in this specification.

[0033] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] In this application, the term "comprising" generally means including the features specifically stated, but not excluding other elements.

[0035] In this application, the term "about" generally refers to a variation within a range of 0.5%-10% above or below the specified value, for example, a variation within a range of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10% above or below the specified value.

[0036] As used herein, the term "dispersion" refers to the process of uniformly mixing, for example, oligomers, reactive diluents, photoinitiators, or the silicon-containing inorganic fillers described below, through stirring or centrifugal motion to achieve uniform distribution of the various mixtures. In specific embodiments, the filler mixture can be incorporated into the resin using various mixing and dispersing or stirring devices, such as dissolvers, planetary mixers, paddle mixers, rotor-stator dispersers, or mixers operating according to the dual asymmetric centrifuge (DAC) principle. On a laboratory scale, DAC mixers enable rapid and simple particle dispersion and simultaneous degassing, even in highly viscous matrices.

[0037] In this application, "min" is an abbreviation for minute, indicating minutes. For example, a stirring speed of 1000 rpm, as described below, indicates 1000 revolutions per minute, such as the number of revolutions of the paddle in a paddle mixer or the number of revolutions of the rotor in a rotor-stator disperser. For another example, a duration of 10 min indicates a duration of 10 minutes. Similarly, "2 h" indicates 2 hours.

[0038] The photosensitive resin material of the present application comprises a resin matrix and a modified silicon-containing inorganic filler. The resin matrix is composed of an acrylate oligomer, a reactive diluent, and a photoinitiator. The modified silicon-containing inorganic filler and the resin matrix are uniformly mixed and then used to produce a dental model using a light-curing 3D printing technique. In one embodiment, the dental model can be used for vacuum molding to produce orthodontic braces.

[0039] The photosensitive resin material of the present application achieves uniform distribution of silicon-containing inorganic fillers in the photosensitive resin matrix through a stirring and dispersion process, and adopts photocuring additive manufacturing technology (for example, through DLP photocuring 3D printing equipment or LCD photocuring 3D printing equipment) to prepare precision dental models with complex structures such as orthodontic braces. In the present application, a coupling agent (for example, a silane coupling agent) is used to modify the surface of the silicon-containing inorganic filler, so that active functional groups are introduced into the surface of the silicon-containing inorganic filler, and an in-situ chemical reaction occurs with the resin matrix during the photocuring molding process to form a stable chemical bond, thereby realizing the preparation of lightweight and high-precision dental models.

[0040] The mass fraction of the photosensitive resin material of the present application is 100% (or 100 parts by weight), the mass fraction of the acrylate oligomer in the resin matrix is 30%-60%, the mass fraction of the active diluent is 20%-50%, the mass fraction of the photoinitiator is 1.5%-3%, and the rest is the modified silicon-containing inorganic filler used to mix the resin matrix, and the mass fraction of the modified silicon-containing inorganic filler is 13%-30%.

[0041] In this application, the modified silicon-containing inorganic filler comprises silicon dioxide or silicate; the particle size of the modified silicon-containing inorganic filler is 0.1-30 μm. In specific embodiments, the modified silicon-containing inorganic filler can be compounded according to different particle sizes and component ratios. The silicon-containing filler can be a commercially available pre-modified filler or an unmodified filler. The unmodified filler must be modified according to the subsequent preparation method of this application in order to be mixed with the resin matrix to prepare the photosensitive resin material.

[0042] The present application prepares a photosensitive resin material by composite modification of a silicon-containing inorganic filler and then composite it with a resin matrix. The orthodontic mold prepared by a light-curing 3D printing process can achieve synergistic optimization of high HDT (heat deformation temperature (HDT): >100°C), high modulus (flexural modulus: >3000MPa) and high strength (flexural strength: >80MPa); at the same time, it reduces the shrinkage of the photosensitive resin (volume shrinkage rate <5%) and improves the printing accuracy (initial model accuracy: 100μm is the scanning scale, and the overlap rate compared with the original model is >90%). In particular, after two vacuum moldings, the model accuracy has an overlap rate of >85% compared with the original model, thereby being able to meet the application requirements of orthodontic molds for 3D printing model resins. That is to say, the photosensitive resin material of the present application maintains dimensional stability under high temperature vacuum conditions, significantly improves the success rate of molding and the accuracy of braces, and therefore can be specifically used in the vacuum molding process of orthodontic braces. After digital sampling and 3D printing, the photosensitive resin material can be used for vacuum molding to prepare orthodontic braces. Compared with plaster models, it can greatly improve production efficiency and reduce labor costs.

[0043] In this application, "oligomer" generally refers to a polymer composed of fewer repeating units. Generally speaking, it can be a polymer composed of ≤50, ≤40, ≤30, ≤20, or 5-10, 10-15, 15-20, or 10-20 repeating units. Oligomers can usually undergo polymerization reactions with the same or other molecules to form polymers with higher molecular weight.

[0044] In this application, the oligomer, also referred to as a prepolymer, is a relatively low-molecular-weight photosensitive resin containing photocurable groups, such as various unsaturated double bonds or epoxy groups. Among the components of the photosensitive resin material for additive manufacturing described in this application, the oligomer is the main component of the resin composition. Its properties largely determine the primary properties of the cured material, making the selection of the oligomer undoubtedly the most crucial step in the design of photocurable products.

[0045] The photosensitive resin material of the present application includes oligomers. In some embodiments, the acrylate oligomer includes one or more of polyester acrylate, polyether acrylate, polyurethane acrylate, and epoxy acrylate. The resin functionality of the selected acrylate oligomer is 2-6.

[0046] In the photosensitive resin material of the present application, the mass fraction of the oligomer used is about 30%-60%, for example, it can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%.

[0047] In the following embodiments, the oligomer selected is polyurethane acrylate. Specifically, the specific materials of polyurethane acrylate selected in the subsequent embodiments include: a modified acrylate oligomer with 3 functionalities (brand: CN989 NS), a modified acrylate oligomer with 2 functionalities (brand: GENOMER*4297), a modified acrylate oligomer with 2 functionalities (brand: GENOMER*4205), a modified acrylate oligomer with 2 functionalities (brand: UDMA), a modified acrylate oligomer with 2 functionalities (brand: CN 151), a modified acrylate oligomer with 2 functionalities (brand: CN983NS), a modified acrylate oligomer with 2 functionalities (brand: GENOMER*4337), or / and a modified acrylate oligomer with 6 functionalities (brand: CN9010 NS), etc.

[0048] Taking the selected oligomer as a modified acrylate oligomer with 3 functionalities (brand: CN989 NS) as an example, CN989NS is a trifunctional aliphatic polyurethane acrylate oligomer with an acrylate functional group at the end. It can undergo rapid free radical crosslinking under UV or electron beam irradiation to form a dense three-dimensional network structure. The viscosity of the material is 13,000-18,000cps (test temperature is 60°C), low color (color APHA: 0-35), and it is a transparent or slightly turbid liquid (appearance grade 1-2). After curing, it does not affect the optical clarity and surface appearance of the molded parts. The material has high hardness, high temperature resistance (heat deformation temperature>120°C), excellent adhesion (can reduce the risk of peeling between printed layers), high wear resistance and weather resistance. The CN989 NS material can be purchased commercially from Sartomer Chemical (ARKEMA), Sartomer (Guangzhou) Chemical Co., Ltd.

[0049] Taking the selected oligomer as a modified acrylate oligomer with 2 functionalities (brand: GENOMER*4297) as an example, GENOMER*4297 is an aliphatic polyurethane dimethacrylate oligomer with a functionality of 2. It can undergo free radical crosslinking under UV or visible light irradiation to form a stable bifunctional three-dimensional network structure. The viscosity range of this material is 8,000–13,000 mPa·s (test temperature is 25°C), which is suitable for compatibility with reactive diluents and meets the requirements of LCD / DLP 3D printing for resin fluidity. It is a low-color (color ≤70 APHA) transparent and clear liquid that does not affect the optical clarity of the printed part after curing. Its refractive index is 1.485 (20°C), which is conducive to the uniform penetration of UV / LED beams in the resin and the control of curing depth. This material has a high viscosity under UV It can be rapidly cross-linked and cured under LED or mercury lamp light source. The cured product has high elastic modulus (e-modulus), high wear resistance, chemical resistance and high light fastness. Its rigidity is manifested in that the tensile strength increases significantly with the elongation (>80MPa when the elongation is 4%). 4297 material is commercially available from the RAHN Group (eg, RAHN Trading (Shanghai) Ltd.).

[0050] Taking the selected oligomer as an example, a difunctional modified acrylate oligomer (brand: GENOMER*4205), GENOMER*4205 consists of an aliphatic polyurethane backbone with methacrylate groups at both ends (Functionality = 2). Under UV / visible light or electron beam irradiation, it undergoes a free radical-induced cross-linking reaction, forming a stable three-dimensional network. Its viscosity range is 7,000–11,000 mPa·s (tested at 25°C), which is suitable for the flowability and thin-layer deposition requirements of LCD / DLP resin systems. Its color (APHA) is ≤100, and it is a transparent and clear liquid. Its refractive index is 1.483 (20°C), which facilitates uniform penetration of UV / LED beams within the resin and control of cure depth. Curing does not affect optical clarity. The material has high strength properties, such as high elastic modulus (e-modulus), high breaking stress (verified by ASTM D 638 testing), and high abrasion resistance, ensuring the structural integrity of printed parts. The GENOMER* 4205 material is commercially available from the RAHN Group (eg, RAHN Trading (Shanghai) Ltd.).

[0051] Taking the selected oligomer as a difunctional modified acrylate oligomer (brand: UDMA) as an example, the UDMA ( HEMATMDI (2-hydroxyethyl methacrylate isocyanate, CAS No. 72869-86-4) is a difunctional dimethacrylate with a viscosity range of 10,000–15,000 mPa·s (tested at 20°C). It has high purity (≥95%), ensuring curing consistency and reducing the risk of cytotoxicity. Its refractive index is 1.485 and its density is 1.11 g / cm 3 . The material can be rapidly cross-linked under 365–405nm UV LED light source, and the cured product has high hardness, excellent wear resistance, and thermal and chemical stability. In particular, the bifunctional groups of the UDMA material provide a moderate degree of cross-linking, balancing the mechanical strength and toughness of dental restorations; the UDMA material meets the biocompatibility requirements of dental materials (passed the ISO 10993 cytotoxicity test), and the isocyanate residue is ≤0.1%. The UDMA material can be purchased from Evonik in Germany. GmbH.

[0052] Taking the selected oligomer as an example, a modified acrylate oligomer with two functionalities (brand: CN 151), this CN 151 material is an epoxy acrylate oligomer (epoxy diacrylate). Its molecular structure contains both epoxy groups and acrylate double bonds. Under UV / electron beam (EB) irradiation, it can form a dense network structure through a dual mechanism of epoxy ring-opening polymerization and acrylate free radical crosslinking. It has the advantage of low shrinkage, with a cure shrinkage rate significantly lower than that of polyurethane systems (which can reduce printed part warping). Its viscosity range is 4,500–6,500 mPa·s (tested at 70°C). This low-to-medium viscosity facilitates mixing with reactive diluents and meets the fluidity and interlayer spreading requirements of LCD / DLP 3D printing resins. The acid value of this CN 151 material is ≤5 mg KOH / g (which can reduce cure inhibition. The epoxy group content provides additional crosslinking sites in the formulation, enhancing network density). Its Gardner color is 0-5, and it has high light transmittance, ensuring printing accuracy. The CN 151 material cures rapidly under 365–405 nm UV LED or electron beam light sources through dual crosslinking of epoxy ring opening and acrylate free radicals. The cured product has flexibility, high adhesion and low cure shrinkage. The CN 151 (CNUVE151 NS) material is commercially available from Sartomer Chemical (ARKEMA), Sartomer (Guangzhou) Chemical Co., Ltd.

[0053] Taking the selected oligomer as a modified acrylate oligomer with 2 functionalities (brand: CN983NS) as an example, the CN983NS material is a difunctional aliphatic polyurethane diacrylate oligomer with a viscosity of 3,400–6,400 cps (test temperature is 60°C), low color (color is 0–100), and a refractive index of 1.4936, which is conducive to light beam penetration and polymerization depth control. It is in a transparent and clear liquid state and does not produce yellowing after curing, which is beneficial to the appearance and dimensional accuracy of the printed parts. The oligomer has a fast light curing response and a high cross-linking density. After curing, it exhibits excellent scratch resistance, chemical resistance and weather resistance. The surface hardness of the molded part is high and it is not easy to leave scratches or scratches. The CN983 NS material is commercially available from Sartomer Chemical (ARKEMA), Sartomer (Guangzhou) Chemical Co., Ltd.

[0054] Taking the selected oligomer as a modified acrylate oligomer with 2 functionalities (brand: GENOMER*4337) as an example, the GENOMER*4337 material is based on a polyurethane diacrylate (PU-diacrylate) oligomer, has an aliphatic backbone structure, has a terminal acrylate bifunctional group, and an average functionality of about 2. Its molecular weight design facilitates a significant reduction in the system viscosity in the formulation while ensuring a high cross-linking density of the network structure after light curing. The viscosity of this material is 3,400–6,400 0 cps (measured at 60°C), making it suitable for use with reactive diluents, meeting the fluidity and thin-film forming requirements of LCD / DLP resins. Its refractive index of 1.4936 facilitates beam transmission and polymerization depth control. Its APHA color range is 0–100, making it a transparent, clear liquid. It does not yellow after curing, enhancing the appearance and dimensional accuracy of printed parts. After curing, this GENOMER* 4337 material exhibits excellent scratch and abrasion resistance, resulting in a high surface hardness that resists scratches and abrasions. This GENOMER* 4337 material is commercially available from the RAHN Group (e.g., RAHN Trading (Shanghai) Ltd.).

[0055] Taking the selected oligomer as a modified acrylate oligomer with 6 functionalities (brand: CN9010 NS) as an example, the CN9010NS material is a polyurethane acrylate oligomer with an end group containing an acrylate group. It can undergo free radical-induced cross-linking polymerization under UV / visible light irradiation to form a three-dimensional network structure. Its viscosity is 1,500-2,500 cps (measured at 60°C). The low viscosity is conducive to mixing with reactive diluents and meeting the fluidity requirements of LCD / DLP 3D printing thin layer molding. The color (APHA) of the material is 0-75, and it is a transparent and clear liquid. The appearance of the cured part is clear, without visible turbidity or yellowing. Its light curing performance is reflected in the ability to quickly cross-link under commonly used UV LED or mercury lamp light sources, significantly shortening the printing time and interlayer curing cycle. The oligomeric structure and multi-functional design make the network dense after curing, taking into account the characteristics of rigidity and hardness. The CN9010 The characteristics of the NS material after curing are high surface hardness, wear resistance and scratch resistance, and excellent adhesion and weather resistance. The CN9010NS material can be purchased from Sartomer Chemical (ARKEMA), Sartomer (Guangzhou) Chemical Co., Ltd.

[0056] For example, in one embodiment, a polyurethane acrylate having a mass fraction of 30% is selected, and a modified acrylate oligomer having a functionality of 2 having a mass fraction of 5% (brand: CN989 NS) and a modified acrylate oligomer having a functionality of 2 having a mass fraction of 25% (brand: GENOMER*4297) can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0057] For example, in another embodiment, a polyurethane acrylate with a mass fraction of 30% is selected, and a modified acrylate oligomer with a functional group of 2 (brand: CN989 NS) with a mass fraction of 5% and a modified acrylate oligomer with a functional group of 2 (brand: GENOMER*4205) with a mass fraction of 25% can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0058] For example, in another embodiment, a polyurethane acrylate with a mass fraction of 50% is selected, and a modified acrylate oligomer with a functional group of 2 (brand: UDMA) with a mass fraction of 25% and a modified acrylate oligomer with a functional group of 2 (brand: CN 151) with a mass fraction of 25% can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0059] For example, in another embodiment, a polyurethane acrylate with a mass fraction of 38% is selected, and a modified acrylate oligomer with a functionality of 2 with a mass fraction of 8% (brand: CN983NS) and a modified acrylate oligomer with a functionality of 2 with a mass fraction of 30% (brand: GENOMER*4337) can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0060] For example, in another embodiment, a polyurethane acrylate with a mass fraction of 60% is selected, and a modified acrylate oligomer with a functionality of 2 (brand: CN983NS) with a mass fraction of 40% and a modified acrylate oligomer with a functionality of 6 (brand: CN9010 NS) with a mass fraction of 20% can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0061] For example, in another embodiment, a polyurethane acrylate with a mass fraction of 30% is selected, and a modified acrylate oligomer with a functional group of 2 (brand: CN983NS) with a mass fraction of 15% and a modified acrylate oligomer with a functional group of 2 (brand: GENOMER*4337) with a mass fraction of 15% can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0062] The photosensitive resin material of the present application contains a reactive diluent, which is also called a monomer or functional monomer. It is a small molecule containing a polymerizable functional group. The reactive diluent is used to dissolve and dilute the oligomer to adjust the viscosity of the system. It also participates in the photocuring reaction and thus affects the various properties of the photocurable product. In the embodiment, the reactive diluent is divided into monofunctional reactive diluents, bifunctional reactive diluents and multifunctional reactive diluents according to the number of reactive groups contained in each molecule. The more functional groups, the higher the reactivity, the higher the crosslinking density, the worse the flexibility, the greater the shrinkage, the better the mechanical properties, the higher the hardness, and the higher the heat resistance; the opposite is true.

[0063] In some embodiments, the reactive diluent includes acryloylmorpholine, isobornyl acrylate, isobornyl methacrylate, 4-tert-butylcyclohexyl acrylate, lauryl acrylate, cyclic trimethylolpropane formal acrylate, tricyclodecane dimethanol diacrylate, phenoxyethyl acrylate, tripropylene glycol diacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, ethylene glycol dimethacrylate, 1,9-nonanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-ethylene glycol diacrylate, and a mixture of one or more of dipropylene glycol diacrylate.

[0064] In one embodiment, the mass fraction of the active diluent used is about 20%-50%, for example, it can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%.

[0065] For example, in one embodiment, a reactive diluent having a mass fraction of 45% is selected, and a composition of 4-tert-butylcyclohexyl acrylate having a mass fraction of 20% and cyclotrimethylolpropane formal acrylate having a mass fraction of 25% as reactive diluents can be used to participate in the preparation of the photosensitive resin material.

[0066] For example, in another embodiment, a reactive diluent with a mass fraction of 50% is selected, and a composition of 40% by mass of 4-tert-butylcyclohexyl acrylate and 10% by mass of dipropylene glycol diacrylate as reactive diluents can be used to prepare the photosensitive resin material.

[0067] For example, in another embodiment, a reactive diluent with a mass fraction of 35% is selected, and a composition of 15% by mass of cyclotrimethylolpropane formal acrylate and 20% by mass of isobornyl acrylate as reactive diluents can be used to prepare the photosensitive resin material.

[0068] For another example, in some embodiments, a single reactive diluent material may be used, such as 4-tert-butylcyclohexyl acrylate with a mass fraction of 20%-45%. Specifically, for example, 4-tert-butylcyclohexyl acrylate with a mass fraction of 45% may be used as a reactive diluent in the preparation of the photosensitive resin material, or 4-tert-butylcyclohexyl acrylate with a mass fraction of 20% may be used as a reactive diluent in the preparation of the photosensitive resin material, or 4-tert-butylcyclohexyl acrylate with a mass fraction of 38% may be used as a reactive diluent in the preparation of the photosensitive resin material.

[0069] In the present application, the photoinitiator, also known as an initiator, is a compound that, after absorbing electromagnetic radiation, typically in the (UV) wavelength range of about 320 nm to 420 nm, decays in a photolysis reaction and thereby forms reactive species that can initiate chemical reactions, primarily polymerization reactions. These reactive species are free radicals or cations. In the present application, a photoinitiator that forms free radicals is used. In principle, any compound that forms free radicals when exposed to suitable radiation can be used as a photoinitiator.

[0070] The photosensitive resin material of the present application includes a photoinitiator, which is the main component of the photocurable product and plays a decisive role in the photocuring rate of the photocurable product. The photoinitiator is a kind of material that absorbs ultraviolet light and excites free radicals or cations, thereby initiating a polymerization reaction. The amount of the photoinitiator added (mass fraction) is usually 1%-5%, but the mass fraction of the photoinitiator used in the photosensitive resin material of the present application is about 1.5%-3%, which does not affect the performance of the photocurable material. The selection of the photoinitiator mainly considers the reaction rate and its corresponding absorption wavelength. Different photoinitiators have their own unique absorption wavelength range. For the ultraviolet light wavelength generated by the corresponding device in the implementation of the first use of the present application is 405nm, the photoinitiator can be selected as a mixture of one or more of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO), 2,4,6-trimethylbenzoyl-di (p-tolyl) phosphine oxide (TMO), phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide (819), methyl benzoylformate (MBF), and camphorquinone (CQ).

[0071] In some embodiments, the mass fraction of the photoinitiator used is about 1.5%-3%, for example, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, or 3%. In a preferred embodiment, the photoinitiator is a phosphine oxide group, which can be activated by radiation in the wavelength range of 355 to 405 nm. For example, the photoinitiator used is 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide (TMO) in the preparation of the photosensitive resin material, and the mass fraction used is, for example, 1.5%, 1.8%, 2%, or 3%.

[0072] The photosensitive resin material of the present application contains a modified silicon-containing inorganic filler with a mass fraction of 13%-30%; wherein the modified silicon-containing inorganic filler contains silicon dioxide or silicate; in the subsequent embodiments, the modified silicon-containing inorganic filler containing silicon dioxide is temporarily used as an example for description.

[0073] In some embodiments, the particle size of the modified silicon-containing inorganic filler is 0.1-30 μm. For example, it can be 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, 39 μm, 40 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm, 50 μm, 51 μm, 52 μm, 53 μm, 54 μm, 55 μm, 56 μm, 57 μm, 58 μm, 59 μm, 60 μm, 61 μm, 16μm, 16.5μm, 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, 20μm, 21μm, 21.5μm, 22μm, 22.5μm, 23μm, 23.5μm, 24μm, 24.5μm, 25μm, 25.5μm, 26μm, 26.5μm, 27μm, 27.5μm, 28μm, 28.5μm, 29μm, 29.5μm, or 30μm. In a specific embodiment, the modified silicon-containing inorganic filler can be compounded according to different particle sizes and component ratios.

[0074] The modified silicon-containing inorganic filler includes a silicon-containing inorganic filler and 1.0% to 5% by mass of fumed silica. In one embodiment, the fumed silica has a specific surface area of 120 m 2 / g of fumed silica.

[0075] In a specific embodiment, the silicon-containing filler can be a commercially available pre-modified filler or an unmodified filler, wherein the commercially available pre-modified filler is, for example, an inert dental glass material with the brand name Schott glass powder. This commercially available inert dental glass material itself has a degree of modification and does not require modification. The unmodified filler needs to be modified according to the subsequent preparation method of this application so as to be mixed with the resin matrix to prepare the photosensitive resin material. In some embodiments, the unmodified filler is, for example, a brand name The silicon-containing inorganic filler can be selected from Nippon Sheet Glass Co., Ltd., or the silicon-containing inorganic filler with the brand name Anmi Vina T801, or the silicon-containing inorganic filler with the brand name Suzhou Jingpin Material V-glass powder.

[0076] The selected brand is Taking the silicon-containing inorganic filler (Nippon Sheet Glass Co., Ltd., NSG Group) as an example, the The silicon-containing inorganic filler is flaky glass powder, specifically flake glass powder, with an average thickness of 1-7μm and a selected particle size range of 1-30μm. It is in the form of irregular hexagonal or diamond flakes. After being mixed with the resin matrix, the material is easily distributed in a directional manner in the resin, and its directional glass flakes form a mechanical support skeleton, which can effectively inhibit the warping deformation caused by the shrinkage of the resin during curing (especially the light curing process) and subsequent use, thereby improving the dimensional retention rate of the molded parts. The flake arrangement of the material blocks the penetration of water vapor and chemical media, thereby extending the service life of the coating or lining; the water vapor permeability decreases significantly with the increase of the flake particle size / thickness ratio. In addition, the The high modulus glass network containing silicon inorganic filler can improve the rigidity (flexural modulus) and hardness of resin composite materials, and enhance the wear and scratch resistance of printed parts; the glass flakes themselves have excellent resistance to UV rays, heat, water and chemicals, and their barrier properties also protect the resin matrix, slowing down the aging degradation caused by factors such as light, heat, oxygen and moisture, thus having excellent weather resistance and durability; as an inorganic glass filler, the material itself has high transparency, and its thin flake form and appropriate addition amount have good transmittance to ultraviolet light (specific wavelength) used for light curing (LCD / DLP), ensuring that the resin can be fully cured; the The material undergoes specific surface treatment (such as silane coupling agent) to improve its compatibility and bonding with the resin matrix, helping to achieve uniform dispersion in the resin and avoid agglomeration, thereby stably exerting its performance advantages. The silicon-containing inorganic filler is commercially available from Nippon Sheet Glass Co., Ltd. (NSG Group).

[0077] Taking the selected silicon-containing inorganic filler brand AnmiVina T801 as an example, the silicon-containing inorganic filler of AnmiVina T801 is flaky glass powder (Glass Flour), which is a glassy crystalline powder. Its main component is silica-alumina glass that is rapidly cooled after high-temperature melting. It is a new inorganic non-metallic functional powder material with an average thickness of about 1-7μm and a particle size range of 1-30μm, which is conducive to stable dispersion and microstructure control in the formula. The oil absorption of this filler is only about 23g / 100g (lower than traditional silica powder), which can reduce resin requirements and allow higher filling amounts (15-30%) without affecting rheology. The silicon-containing inorganic filler of AnmiVina T801 has a high refractive index transparent filling, and its glass flake form still maintains high light transmittance after the resin is cured. This reduces formulation turbidity, ensuring optical clarity and fine detail reproduction in printed parts. The material's rigid flake glass forms a reinforcing phase in the curing system, significantly improving the surface hardness, abrasion resistance, and scratch resistance of the coating / printed parts. The AnmiVina T801 material has low surface tension and a regular particle morphology, enabling uniform suspension in commonly used acrylate-based photocurable resins and reactive diluents with simple mechanical stirring, without agglomeration or sedimentation. Its flake structure exhibits low shear resistance rheologically, maintaining good flowability even at filler levels (13–30 wt%), making it suitable for the thin layer spreading requirements of LCD / DLP 3D printing. Furthermore, the chemically inert glass matrix of the AnmiVina T801 material is resistant to most organic solvents, acids, bases, and humid environments, ensuring that printed parts are less susceptible to delamination, swelling, or flaking during long-term indoor or outdoor use. The silicon-containing inorganic filler in the AnmiVina T801 material is commercially available from Anmi Micro-Nano Materials (Guangzhou) Co., Ltd.

[0078] Taking the silicon-containing inorganic filler of the V-glass powder of Suzhou Jingpin Material as an example, the silicon-containing inorganic filler of the V-glass powder is made of inorganic non-metallic minerals such as high-purity quartz as raw materials, which are melted at high temperature and quenched into glass, and then crushed, ground and classified to obtain a glass phase powder with controllable particle size. Its phase state and chemical stability are excellent. The silicon-containing inorganic filler is an amorphous (glass phase) powder with no crystalline impurities and has excellent chemical inertness. It shows excellent corrosion resistance to acids, alkalis and most organic solvents; its particle size classification can reach micron level (optional D 50 The powder has a regular morphology and a smooth surface, which is conducive to dispersion and reduces rheological viscosity increase. The oil absorption value of the silicon-containing inorganic filler is 18-22g / 100g and the density is about 2.5g / cm 3The V-glass powder has a Mohs hardness of 5-6 and a refractive index of 1.52-1.55 (≤0.03 difference from the resin matrix). This excellent refractive index matching facilitates light transmission and cure depth control in the resin system. The silicon-containing inorganic filler in this V-glass powder exhibits shrinkage suppression and dimensional stability in photocurable resins. Its regular powder filling forms a micron-scale support skeleton during the curing process, reducing volume shrinkage and inhibiting warpage. Furthermore, its surface hardness and wear resistance are enhanced by the filler's high hardness, significantly improving the scratch and wear resistance of printed parts. The material's amorphous glass phase and high-purity formula ensure excellent transparency even after high filling, making it suitable for fine structure molding. The powder surface can be modified with silane coupling to further enhance dispersibility and resin-matrix interfacial bonding strength. The powder is highly compatible with acrylates, commonly used reactive diluents, and photoinitiators (such as TMO or TPO). The silicon-containing inorganic filler in this V-glass powder is commercially available from Jingpin Material Technology (Suzhou) Co., Ltd.

[0079] The commercially available pre-modified filler is, for example, an inert dental glass material of the selected brand Schott glass powder. The inert dental glass material of the Schott glass powder is, for example, Dental glass powder (inert dental glass filler, model example P1000275) is an amorphous (glass phase) fine powder, the main component of which is high-purity silica-alumina special optical glass, containing adjustable metal oxide modifiers for precise control of refractive index and chemical stability. It has a wide range of particle sizes, such as Nano Grade ultra-fine up to D 50 ≈180nm. The standard particle size D of the inert dental glass filler 50 ≈0.4μm, etc., which can meet the different layer thickness and resolution requirements in 3D printing, and larger particle size specifications such as 2-5μm and 10-20μm can also be selected as needed; this inert dental glass filler is easy to disperse evenly in acrylate, inhibiting agglomeration and sedimentation. Its refractive index can be adjusted from 1.50–1.61, accurately matching the refractive index of the resin matrix, minimizing light scattering and shadow effects during the curing process. Due to the excellent transparency of this inert dental glass filler, the resin system maintains high light transmittance after filling, making it suitable for high-precision LCD / DLP printing. This inert dental glass filler has a high glass phase hardness (Mohs hardness ≈ 5–6), significantly improving the surface hardness, wear resistance, and scratch resistance of cured parts. Its micron-scale support skeleton, constructed from regular micropowders, suppresses volume shrinkage (<1%) and warping during the curing process, improving the dimensional retention and precision of printed parts. Furthermore, it is extremely chemically inert, exhibiting excellent chemical and hydrolysis resistance to most organic solvents, acids, bases, and ambient humidity. This inert dental glass material, manufactured with SCHOTT glass powder, is a commercially available pre-modified filler that enhances interfacial bonding strength with organic resin matrices. This inert dental glass material, commercially available under the SCHOTT brand, is available from SCHOTT.

[0080] In one embodiment, the modified silicon-containing inorganic filler is prepared by surface-modifying the silicon-containing inorganic filler using a silane coupling agent. In this embodiment, the mass fraction of the silane coupling agent in the silicon-containing inorganic filler is 1%-5%, for example, the mass fraction of the silane coupling agent in the silicon-containing inorganic filler is 2%. In this embodiment, the silane coupling agent includes one or a mixture of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS).

[0081] For example, in one embodiment, only 3-methacryloxypropyltrimethoxysilane (MPS) accounting for 2% by mass of the silicon-containing inorganic filler can be selected as a silane coupling agent to modify the surface of the silicon-containing inorganic filler. In another embodiment, a mixture of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS) can be selected as a silane coupling agent to modify the surface of the silicon-containing inorganic filler, with the mixture accounting for 2% by mass of the silicon-containing inorganic filler.

[0082] In one embodiment, the modified silicon-containing inorganic filler is obtained by sequentially adding a silicon-containing inorganic filler and a silane coupling agent to an ethanol-water mixture, adjusting the pH to 3.5-4 with a diluted acetic acid solution, and then drying the mixture. In this embodiment, the ethanol-water mixture is formed by dispersing 20%-40% ethanol by mass and 60%-80% pure water by mass. In a more specific embodiment, the ethanol-water mixture is formed by dispersing 25% ethanol by mass and 75% pure water by mass.

[0083] This application also provides a method for preparing a photosensitive resin material for additive manufacturing for 3D printing. Figure 1 , which is a flow chart of a method for preparing a photosensitive resin material of the present application in one embodiment. As shown in the figure, the preparation method includes the following steps:

[0084] Execute step S11. Under room temperature, add 20%-50% of the active diluent by mass and 1.5%-3% of the photoinitiator by mass into a stirring tank, and use a dispersing device to disperse them at a speed of 500-1000 r / min for 30-60 minutes. In this embodiment, the room temperature environment is, for example, a room temperature of 25±5°C and no strong light irradiation environment, add 20%-50% of the active diluent by mass and 1.5%-3% of the photoinitiator by mass into a stirring tank, and use a dispersing device such as a stirring device to disperse them at a speed of, for example, about 500 rpm / min, 600 rpm / min, 700 rpm / min, 800 rpm / min, 900 rpm / min, or 1000 rpm / min, preferably 800 rpm / min, for about 30 minutes to dissolve the initiator completely.

[0085] In some embodiments, the reactive diluent includes acryloylmorpholine, isobornyl acrylate, isobornyl methacrylate, 4-tert-butylcyclohexyl acrylate, lauryl acrylate, cyclic trimethylolpropane formal acrylate, tricyclodecane dimethanol diacrylate, phenoxyethyl acrylate, tripropylene glycol diacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, ethylene glycol dimethacrylate, 1,9-nonanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-ethylene glycol diacrylate, and a mixture of one or more of dipropylene glycol diacrylate.

[0086] For example, in one embodiment, a reactive diluent having a mass fraction of 45% is selected, and a composition of 4-tert-butylcyclohexyl acrylate having a mass fraction of 20% and cyclotrimethylolpropane formal acrylate having a mass fraction of 25% as reactive diluents can be used to participate in the preparation of the photosensitive resin material.

[0087] For example, in another embodiment, a reactive diluent with a mass fraction of 50% is selected, and a composition of 40% by mass of 4-tert-butylcyclohexyl acrylate and 10% by mass of dipropylene glycol diacrylate as reactive diluents can be used to prepare the photosensitive resin material.

[0088] For example, in another embodiment, a reactive diluent with a mass fraction of 35% is selected, and a composition of 15% by mass of cyclotrimethylolpropane formal acrylate and 20% by mass of isobornyl acrylate as reactive diluents can be used to prepare the photosensitive resin material.

[0089] For another example, in some embodiments, a single reactive diluent material may be used, such as 4-tert-butylcyclohexyl acrylate with a mass fraction of 20%-45%. Specifically, for example, 4-tert-butylcyclohexyl acrylate with a mass fraction of 45% may be used as a reactive diluent in the preparation of the photosensitive resin material, or 4-tert-butylcyclohexyl acrylate with a mass fraction of 20% may be used as a reactive diluent in the preparation of the photosensitive resin material, or 4-tert-butylcyclohexyl acrylate with a mass fraction of 38% may be used as a reactive diluent in the preparation of the photosensitive resin material.

[0090] In some embodiments, the photoinitiator can be selected from a mixture of one or more of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO), 2,4,6-trimethylbenzoyl-di(p-tolyl) phosphine oxide (TMO), phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide (819), methyl benzoylformate (MBF), and camphorquinone (CQ). In a preferred embodiment, the photoinitiator is a phosphine oxide group, which can be activated by radiation in the wavelength range of 355 to 405 nm. For example, the photoinitiator used is 2,4,6-trimethylbenzoyl-di(p-tolyl) phosphine oxide (TMO) to participate in the preparation of the photosensitive resin material, and the mass fraction used is, for example, 1.5%, 1.8%, 2%, or 3%.

[0091] Execute step S12, add 30%-60% of the mass fraction of the acrylate oligomer into the stirred tank, and use the dispersion equipment to continue dispersing at a speed of 500-1000 r / min for 30-60 minutes to obtain a resin matrix; in this embodiment, the acrylate oligomer is added to the liquid mixed evenly in the above step S11, and continues to disperse at a rate of 500 rpm / min, 600 rpm / min, 700 rpm / min, 800 rpm / min, 900 rpm / min, or 1000 rpm / min, preferably 500 rpm / min, for about 30 minutes to obtain a completely uniformly dispersed resin matrix.

[0092] In some embodiments, the acrylate oligomer includes one or more of polyester acrylate, polyether acrylate, polyurethane acrylate, and epoxy acrylate, and the resin functionality of the selected acrylate oligomer is 2-6. For example, the specific materials of the selected polyurethane acrylate are: 2-functionality modified acrylate oligomer (brand: CN989 NS), 2-functionality modified acrylate oligomer (brand: GENOMER*4297), 2-functionality modified acrylate oligomer (brand: GENOMER*4205), 2-functionality modified acrylate oligomer (brand: UDMA), 2-functionality modified acrylate oligomer (brand: CN 151), 2-functionality modified acrylate oligomer (brand: CN983NS), 2-functionality modified acrylate oligomer (brand: GENOMER*4337), or / and 6-functionality modified acrylate oligomer (brand: CN9010 NS), etc.

[0093] For example, in one embodiment, a polyurethane acrylate having a mass fraction of 30% is selected, and a modified acrylate oligomer having a functionality of 2 having a mass fraction of 5% (brand: CN989 NS) and a modified acrylate oligomer having a functionality of 2 having a mass fraction of 25% (brand: GENOMER*4297) can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0094] Alternatively, in another embodiment, a polyurethane acrylate having a mass fraction of 30% is selected, and a modified acrylate oligomer having a functionality of 2 having a mass fraction of 5% (brand: CN989 NS) and a modified acrylate oligomer having a functionality of 2 having a mass fraction of 25% (brand: GENOMER*4205) can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0095] Alternatively, in another embodiment, a polyurethane acrylate having a mass fraction of 50% is selected, and a modified acrylate oligomer having a functionality of 2 with a mass fraction of 25% (brand: UDMA) and a modified acrylate oligomer having a functionality of 2 with a mass fraction of 25% (brand: CN 151) can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0096] Alternatively, in another embodiment, a polyurethane acrylate with a mass fraction of 38% is selected, and a modified acrylate oligomer with a functionality of 2 with a mass fraction of 8% (brand: CN983NS) and a modified acrylate oligomer with a functionality of 2 with a mass fraction of 30% (brand: GENOMER*4337) can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0097] Alternatively, in another embodiment, a polyurethane acrylate having a mass fraction of 60% is selected, and a modified acrylate oligomer having a functionality of 2 (brand: CN983NS) having a mass fraction of 40% and a modified acrylate oligomer having a functionality of 6 (brand: CN9010 NS) having a mass fraction of 20% can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0098] Alternatively, in another embodiment, a polyurethane acrylate with a mass fraction of 30% is selected, and a modified acrylate oligomer with a functional group of 2 (brand: CN983NS) with a mass fraction of 15% and a modified acrylate oligomer with a functional group of 2 (brand: GENOMER*4337) with a mass fraction of 15% can be used as a composition of oligomers to participate in the preparation of the photosensitive resin material.

[0099] Execute step S13, add the modified silicon-containing inorganic filler with a mass fraction of 13%-30% to the resin matrix prepared in step S12, and continue to disperse it for 60-90 minutes using the dispersing equipment at a speed of 500-1000 r / min; wherein the components of the modified silicon-containing inorganic filler include silicon dioxide or silicate; the particle size of the modified silicon-containing inorganic filler is 0.1-30 μm; in this embodiment, the modified silicon-containing inorganic filler with a mass fraction of 13%-30% is added to the stirring tank and mixed with the resin matrix, and a dispersing equipment such as a stirring equipment is used at a speed of, for example, about 500 rpm / min, 600 rpm / min, 700 rpm / min, 800 rpm / min, 900 rpm / min, or 1000 rpm / min, preferably 500 rpm / min, for about 90 minutes, so that the modified silicon-containing inorganic filler is evenly dispersed.

[0100] The modified silicon-containing inorganic filler includes a silicon-containing inorganic filler and 1.0% to 5% by mass of fumed silica. In one embodiment, the fumed silica has a specific surface area of 120 m 2 / g of fumed silica.

[0101] The particle size of the modified silicon-containing inorganic filler is 0.1-30 μm. In a specific embodiment, the modified silicon-containing inorganic filler can be compounded according to different particle sizes and component ratios.

[0102] In a specific embodiment, the silicon-containing filler can be a commercially available pre-modified filler or an unmodified filler, wherein the commercially available pre-modified filler is, for example, an inert dental glass material with the brand name Schott glass powder. This commercially available inert dental glass material itself has a degree of modification and does not require modification. The unmodified filler needs to be modified according to the subsequent preparation method of this application so as to be mixed with the resin matrix to prepare the photosensitive resin material. In some embodiments, the unmodified filler is, for example, a brand name The silicon-containing inorganic filler can be selected from Nippon Sheet Glass Co., Ltd., or the silicon-containing inorganic filler with the brand name Anmi Vina T801, or the silicon-containing inorganic filler with the brand name Suzhou Jingpin Material V-glass powder.

[0103] In one embodiment, the modified silicon-containing inorganic filler is prepared by surface-modifying the silicon-containing inorganic filler using a silane coupling agent. In this embodiment, the mass fraction of the silane coupling agent in the silicon-containing inorganic filler is 1%-5%, for example, the mass fraction of the silane coupling agent in the silicon-containing inorganic filler is 2%. In this embodiment, the silane coupling agent includes one or a mixture of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS).

[0104] For example, in one embodiment, only 3-methacryloxypropyltrimethoxysilane (MPS) accounting for 2% by mass of the silicon-containing inorganic filler can be selected as a silane coupling agent to modify the surface of the silicon-containing inorganic filler. In another embodiment, a mixture of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS) can be selected as a silane coupling agent to modify the surface of the silicon-containing inorganic filler, with the mixture accounting for 2% by mass of the silicon-containing inorganic filler.

[0105] In one embodiment, the modified silicon-containing inorganic filler is obtained by sequentially adding a silicon-containing inorganic filler and a silane coupling agent to an ethanol-water mixture, adjusting the pH to 3.5-4 with a diluted acetic acid solution, and then drying the mixture. In this embodiment, the ethanol-water mixture is formed by dispersing 20%-40% ethanol by mass and 60%-80% pure water by mass. In a more specific embodiment, the ethanol-water mixture is formed by dispersing 25% ethanol by mass and 75% pure water by mass.

[0106] Step S14 is executed. After stirring is completed, the photosensitive resin material is filtered using a 200-mesh filter cloth and is ready for packaging. In an embodiment, after performing step S13, the photosensitive resin material is filtered using a 200-mesh filter cloth to remove any large solid impurities that may be present. After filtering the photosensitive resin material and completing the packaging, the preparation of the photosensitive resin material is completed.

[0107] In a specific embodiment, the silicon-containing filler can be a commercially available pre-modified filler or an unmodified filler, wherein the commercially available pre-modified filler is, for example, an inert dental glass material with the brand name Schott glass powder. This commercially available inert dental glass material itself has a degree of modification and does not need to be modified. However, the unmodified filler needs to be modified in order to be mixed with the resin matrix to prepare the photosensitive resin material. Therefore, the preparation method of the photosensitive resin material of the present application also includes step S10 of preparing the silicon-containing inorganic filler into a modified silicon-containing inorganic filler, see Figure 2 , which is a flow chart of another embodiment of a method for preparing a photosensitive resin material of the present application. As shown in the figure, the preparation method includes the following steps:

[0108] Execute step S101, add the silicon-containing inorganic filler to be modified (i.e., unmodified filler) into the pre-made modification liquid and ultrasonically disperse for 10-25 minutes until the silicon-containing inorganic filler is uniformly suspended; in this embodiment, the modification liquid is formed by mixing 20%-40% ethanol and 60%-80% pure water to form an ethanol-water mixture. The unmodified filler is, for example, a brand of The silicon-containing inorganic filler can be selected from Nippon Sheet Glass Co., Ltd., or the silicon-containing inorganic filler with the brand name Anmi Vina T801, or the silicon-containing inorganic filler with the brand name Suzhou Jingpin Material V-glass powder.

[0109] In this embodiment, 25% ethanol and 75% pure water are added to a stirring tank at room temperature and stirred and dispersed at 1000 rpm. The ethanol-water mixture formed by stirring for 30 minutes is used as a modifying liquid. Then, the silicon-containing inorganic filler to be modified is added to the prefabricated stirring tank and mixed with the modifying liquid. For example, an ultrasonic device is used to ultrasonically disperse for 15 minutes until the silicon-containing inorganic filler is evenly suspended in the solution.

[0110] Step S102 is performed, where a silane coupling agent is added at a rate of 1% to 5% of the mass of the silicon-containing inorganic filler. A diluted acetic acid solution is then added to adjust the pH to 3.5 to 4.0, and the mixture is stirred at 800 to 1200 rpm for 30 to 90 minutes. The mixture is then filtered and dried in an oven at 80°C for 2 hours to obtain the modified silicon-containing inorganic filler. The silane coupling agent may include one or a mixture of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS).

[0111] In some embodiments, the mass fraction of the silane coupling agent in the silicon-containing inorganic filler is 1%-5%, for example, 1%, 2%, 3%, 4%, or 5%. In this embodiment, the silane coupling agent is added at a mass fraction of 2% of the silicon-containing inorganic filler, and then diluted acetic acid solution is added to adjust the pH value to 4.0, and then a dispersion device is used to stir at a speed of 1000 rpm for 90 minutes. Then, a 200-mesh filter cloth is used to filter out any large solid particles that may be present, and then the mixture is placed in an 80°C oven to dry for 2 hours to obtain the modified silicon-containing inorganic filler.

[0112] In another embodiment provided in the present application, the resin material or resin product formed by curing the photosensitive resin material can be used as a liquid resin material for photocuring 3D printing, such as using a photocuring 3D printing device using a surface exposure process such as DLP or LCD to print 3D objects, such as a mold for preparing orthodontic braces, that is, using a vacuum mold to prepare orthodontic braces.

[0113] In another embodiment provided in the present application, the product made by 3D printing of the photosensitive resin material is suitable for preparing a mold for orthodontic braces, that is, orthodontic braces are prepared using a vacuum mold.

[0114] Example 1:

[0115] The following provides Example 1, which provides a photosensitive resin material for additive manufacturing, which is composed of the following components in parts by mass:

[0116] The raw materials for preparing the photosensitive resin for additive manufacturing are as follows, in parts by mass: 5 parts of difunctional modified acrylate oligomer (brand: CN989 NS), 25 parts of difunctional modified acrylate oligomer (brand: GENOMER*4297), 20 parts of 4-tert-butyl cyclohexyl acrylate, 25 parts of cyclotrimethylolpropane formal acrylate, 22 parts of modified silicon-containing inorganic filler (brand: High-performance materials, Nippon Sheet Glass Co., Ltd.), 2 parts of 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, 1 part of fumed silica (specific surface area of 120 m 2 / g).

[0117] Preparation method: 25% ethanol and 75% pure water are added to a stirring tank at room temperature and stirred and dispersed at 1000 rpm. The ethanol-water mixture formed by stirring for 30 minutes is used as the modification liquid. Then, the silicon-containing inorganic filler to be modified is added to the prefabricated stirring tank and mixed with the modification liquid. Ultrasonic dispersion is used for 15 minutes until the silicon-containing inorganic filler is evenly suspended in the solution. 3-methacryloxypropyltrimethoxysilane (MPS) is added at a ratio of 2% of the mass of the silicon-containing inorganic filler. Then, diluted acetic acid solution is added to adjust the pH to 4. Then, a dispersing device is used to stir and disperse at 1000 rpm for 90 minutes, filtered, and dried in an 80°C oven for 2 hours to obtain the modified silicon-containing inorganic filler.

[0118] Next, at room temperature and without strong light, the active diluent and photoinitiator are placed in a stirred tank and dispersed at 800 rpm for 30 minutes using a dispersing device. The aforementioned acrylate oligomer is then added to the stirred tank and dispersed at room temperature and 500 rpm for 30-60 minutes. The modified silicon-containing inorganic filler and fumed silica are then added to the stirred tank and dispersed at room temperature and 500 rpm for 90 minutes. After stirring, the product is filtered using a 200-mesh filter cloth and bottled. This completes the preparation.

[0119] A Resai Edge E2 3D printer was used, and a curing technology using an LCD (the LCD screen was a 9.25-inch 6K black and white screen) radiation light source was adopted. The photosensitive resin material prepared by the above preparation method was poured into the resin tank of the 3D printing device. At normal room temperature (e.g., room temperature of 25±5°C) and normal humidity (e.g., 50±20%), the wavelength was 405nm, the layer thickness was 0.05mm, and the light intensity was 4mW / cm 2 3D printing is performed under the setting parameters of 75mm / h and a molding speed of 75mm / h. The sample of the 3D component completed by 3D printing is then placed in a 25-30℃ environment with a secondary curing light source (for example, in a curing box with a light source of 60mW / cm 2 , ultraviolet light with a wavelength of 405nm) for 10-60 minutes for secondary ultraviolet curing, and placed at normal room temperature (for example, room temperature of 25±5°C) and normal humidity conditions (for example, 50±20%) for 24 hours to obtain a 3D printed sample.

[0120] The sample was tested for its flexural strength (Mpa) and flexural modulus (Mpa), heat deformation temperature (HDT, ℃), volume shrinkage (%), initial accuracy (%), and overlap rate (%) between the two laminations and the original model. The test results are shown in Table 1. The sample was then cleaned with alcohol and stored at room temperature for 3 days to verify its storage capacity. The test results are shown in Table 2.

[0121] Example 2:

[0122] The following provides Example 2. This example provides a photosensitive resin material for additive manufacturing, which is composed of the following components in parts by mass:

[0123] The raw materials for preparing the photosensitive resin for additive manufacturing are as follows, in parts by mass: 5 parts of difunctional modified acrylate oligomer (brand: CN989 NS), 25 parts of difunctional modified acrylate oligomer (brand: GENOMER*4205), 40 parts of 4-tert-butylcyclohexyl acrylate, 10 parts of dipropylene glycol diacrylate, 15.2 parts of modified silicon-containing inorganic filler (brand: Anmivina T801), 1.8 parts of 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, 3 parts of fumed silica (specific surface area of 120m 2 / g).

[0124] Preparation method: 25% ethanol and 75% pure water are added to a stirring tank at room temperature and stirred and dispersed at 1000 rpm. The ethanol-water mixture formed by stirring for 30 minutes is used as the modification liquid. Then, the silicon-containing inorganic filler to be modified is added to the prefabricated stirring tank and mixed with the modification liquid. Ultrasonic dispersion is used for 15 minutes until the silicon-containing inorganic filler is evenly suspended in the solution. 3-methacryloxypropyltrimethoxysilane (MPS) is added at a ratio of 2% of the mass of the silicon-containing inorganic filler. Then, diluted acetic acid solution is added to adjust the pH to 4. Then, a dispersing device is used to stir and disperse at 1000 rpm for 90 minutes, filtered, and dried in an 80°C oven for 2 hours to obtain the modified silicon-containing inorganic filler.

[0125] Next, at room temperature and without strong light, the active diluent and photoinitiator are placed in a stirred tank and dispersed at 800 rpm for 30 minutes using a dispersing device. The aforementioned acrylate oligomer is then added to the stirred tank and dispersed at room temperature and 500 rpm for 30-60 minutes. The modified silicon-containing inorganic filler and fumed silica are then added to the stirred tank and dispersed at room temperature and 500 rpm for 90 minutes. After stirring, the product is filtered using a 200-mesh filter cloth and bottled. This completes the preparation.

[0126] A Resai Edge E2 3D printer was used, and a curing technology using an LCD (the LCD screen was a 9.25-inch 6K black and white screen) radiation light source was adopted. The photosensitive resin material prepared by the above preparation method was poured into the resin tank of the 3D printing device. At normal room temperature (e.g., room temperature of 25±5°C) and normal humidity (e.g., 50±20%), the wavelength was 405nm, the layer thickness was 0.05mm, and the light intensity was 4mW / cm 2 3D printing is performed under the setting parameters of 75mm / h and a molding speed of 75mm / h. The sample of the 3D component completed by 3D printing is then placed in a 25-30℃ environment with a secondary curing light source (for example, in a curing box with a light source of 60mW / cm 2 , ultraviolet light with a wavelength of 405nm) for 10-60 minutes for secondary ultraviolet curing, and placed at normal room temperature (for example, room temperature of 25±5°C) and normal humidity conditions (for example, 50±20%) for 24 hours to obtain a 3D printed sample.

[0127] The sample was tested for its flexural strength (Mpa) and flexural modulus (Mpa), heat deformation temperature (HDT, ℃), volume shrinkage (%), initial accuracy (%), and overlap rate (%) between the two laminations and the original model. The test results are shown in Table 1. The sample was then cleaned with alcohol and stored at room temperature for 3 days to verify its storage capacity. The test results are shown in Table 2.

[0128] Example 3:

[0129] The following provides Example 3. This example provides a photosensitive resin material for additive manufacturing, which is composed of the following components in parts by mass:

[0130] The raw materials for preparing the photosensitive resin for additive manufacturing are as follows, in parts by mass: 25 parts of difunctional modified acrylate oligomer (brand: UDMA), 25 parts of difunctional modified acrylate oligomer (brand: CN 151), 20 parts of isobornyl acrylate, 15 parts of cyclotrimethylolpropane formal acrylate, 10 parts of modified silicon-containing inorganic filler (brand: Suzhou Jingpin Materials-V-type glass powder), 2 parts of 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, 3 parts of fumed silica (specific surface area of 80m 2 / g).

[0131] Preparation method: 25% ethanol and 75% pure water are added to a stirring tank at room temperature and stirred and dispersed at 1000 rpm. The ethanol-water mixture formed by stirring for 30 minutes is used as a modification liquid. Then, the silicon-containing inorganic filler to be modified is added to the pre-prepared stirring tank and mixed with the modification liquid. Ultrasonic dispersion is used for 15 minutes until the silicon-containing inorganic filler is evenly suspended in the solution. A mixture of 3-methacryloxypropyltrimethoxysilane (MPS) and 3-aminopropyltriethoxysilane (APTES) in equal proportions is added at a ratio of 2% of the mass of the silicon-containing inorganic filler. Then, diluted acetic acid solution is added to adjust the pH to 3.5. Then, a dispersing device is used to stir and disperse at 1000 rpm for 90 minutes, filtered, and dried in an 80°C oven for 2 hours to obtain a modified silicon-containing inorganic filler.

[0132] Next, at room temperature and without strong light, the active diluent and photoinitiator are placed in a stirred tank and dispersed at 800 rpm for 30 minutes using a dispersing device. The aforementioned acrylate oligomer is then added to the stirred tank and dispersed at room temperature and 500 rpm for 30-60 minutes. The modified silicon-containing inorganic filler and fumed silica are then added to the stirred tank and dispersed at room temperature and 500 rpm for 90 minutes. After stirring, the product is filtered using a 200-mesh filter cloth and bottled. This completes the preparation.

[0133] A Resai Edge E2 3D printer was used, and a curing technology using an LCD (the LCD screen was a 9.25-inch 6K black and white screen) radiation light source was adopted. The photosensitive resin material prepared by the above preparation method was poured into the resin tank of the 3D printing device. At normal room temperature (e.g., room temperature of 25±5°C) and normal humidity (e.g., 50±20%), the wavelength was 405nm, the layer thickness was 0.05mm, and the light intensity was 4mW / cm 2 3D printing is performed under the setting parameters of 75mm / h and a molding speed of 75mm / h. The sample of the 3D component completed by 3D printing is then placed in a 25-30℃ environment with a secondary curing light source (for example, in a curing box with a light source of 60mW / cm 2 , ultraviolet light with a wavelength of 405nm) for 10-60 minutes for secondary ultraviolet curing, and placed at normal room temperature (for example, room temperature of 25±5°C) and normal humidity conditions (for example, 50±20%) for 24 hours to obtain a 3D printed sample.

[0134] The sample was tested for its flexural strength (Mpa) and flexural modulus (Mpa), heat deformation temperature (HDT, ℃), volume shrinkage (%), initial accuracy (%), and overlap rate (%) between the two laminations and the original model. The test results are shown in Table 1. The sample was then cleaned with alcohol and stored at room temperature for 3 days to verify its storage capacity. The test results are shown in Table 2.

[0135] Example 4:

[0136] The following provides Example 4. This example provides a photosensitive resin material for additive manufacturing, which is composed of the following components in parts by mass:

[0137] The raw materials for preparing the photosensitive resin for additive manufacturing are as follows, in parts by mass: 8 parts of difunctional modified acrylate oligomer (brand: CN983NS), 30 parts of difunctional modified acrylate oligomer (brand: GENOMER*4337), 45 parts of 4-tert-butylcyclohexyl acrylate, 9 parts of modified silicon-containing inorganic filler (brand: Schott glass powder-inert dental glass), 3 parts of 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, 5 parts of fumed silica (specific surface area of 120m 2 / g).

[0138] This commercially available silicon-containing inorganic filler (brand: Schott glass powder - inert dental glass) has its own degree of modification and does not require modification.

[0139] Preparation method: At room temperature and without strong light, place the active diluent and photoinitiator into a stirred tank and disperse them using a dispersing device at 800 rpm for 30 minutes. Then, add the aforementioned acrylate oligomer to the stirred tank and disperse them at room temperature at 500 rpm for 30-60 minutes. Add the modified silicon-containing inorganic filler (brand: Schott glass powder - inert dental glass) and fumed silica to the stirred tank and disperse them at room temperature at 500 rpm for 90 minutes. After stirring, filter the product using a 200-mesh filter cloth and bottle.

[0140] A Resai Edge E2 3D printer was used, and a curing technology using an LCD (the LCD screen was a 9.25-inch 6K black and white screen) radiation light source was adopted. The photosensitive resin material prepared by the above preparation method was poured into the resin tank of the 3D printing device. At normal room temperature (e.g., room temperature of 25±5°C) and normal humidity (e.g., 50±20%), the wavelength was 405nm, the layer thickness was 0.05mm, and the light intensity was 4mW / cm 23D printing is performed under the setting parameters of 75mm / h and a molding speed of 75mm / h. The sample of the 3D component completed by 3D printing is then placed in a 25-30℃ environment with a secondary curing light source (for example, in a curing box with a light source of 60mW / cm 2 , ultraviolet light with a wavelength of 405nm) for 10-60 minutes for secondary ultraviolet curing, and placed at normal room temperature (for example, room temperature of 25±5°C) and normal humidity conditions (for example, 50±20%) for 24 hours to obtain a 3D printed sample.

[0141] The sample was tested for its flexural strength (Mpa) and flexural modulus (Mpa), heat deformation temperature (HDT, ℃), volume shrinkage (%), initial accuracy (%), and overlap rate (%) between the two laminations and the original model. The test results are shown in Table 1. The sample was then cleaned with alcohol and stored at room temperature for 3 days to verify its storage capacity. The test results are shown in Table 2.

[0142] Example 5:

[0143] The following provides Example 5. This example provides a photosensitive resin material for additive manufacturing, which is composed of the following components in parts by mass:

[0144] The raw materials for preparing the photosensitive resin for additive manufacturing are as follows, in parts by mass: 40 parts of difunctional modified acrylate oligomer (brand: CN983NS), 20 parts of hexafunctional modified acrylate oligomer (brand: CN9010 NS), 20 parts of 4-tert-butylcyclohexyl acrylate, 16.5 parts of modified silicon-containing inorganic filler (brand: Schott glass powder-inert dental glass), 1.5 parts of 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, 2 parts of fumed silica (specific surface area of 120m 2 / g).

[0145] This commercially available silicon-containing inorganic filler (brand: Schott glass powder - inert dental glass) has its own degree of modification and does not require modification.

[0146] Preparation method: At room temperature and without strong light, place the active diluent and photoinitiator into a stirred tank and disperse them using a dispersing device at 800 rpm for 30 minutes. Then, add the aforementioned acrylate oligomer to the stirred tank and disperse them at room temperature at 500 rpm for 30-60 minutes. Add the modified silicon-containing inorganic filler (brand: Schott glass powder - inert dental glass) and fumed silica to the stirred tank and disperse them at room temperature at 500 rpm for 90 minutes. After stirring, filter the product using a 200-mesh filter cloth and bottle.

[0147] A Resai Edge E2 3D printer was used, and a curing technology using an LCD (the LCD screen was a 9.25-inch 6K black and white screen) radiation light source was adopted. The photosensitive resin material prepared by the above preparation method was poured into the resin tank of the 3D printing device. At normal room temperature (e.g., room temperature of 25±5°C) and normal humidity (e.g., 50±20%), the wavelength was 405nm, the layer thickness was 0.05mm, and the light intensity was 4mW / cm 2 3D printing is performed under the setting parameters of 75mm / h and a molding speed of 75mm / h. The sample of the 3D component completed by 3D printing is then placed in a 25-30℃ environment with a secondary curing light source (for example, in a curing box with a light source of 60mW / cm 2 , ultraviolet light with a wavelength of 405nm) for 10-60 minutes for secondary ultraviolet curing, and placed at normal room temperature (for example, room temperature of 25±5°C) and normal humidity conditions (for example, 50±20%) for 24 hours to obtain a 3D printed sample.

[0148] The sample was tested for its flexural strength (Mpa) and flexural modulus (Mpa), heat deformation temperature (HDT, ℃), volume shrinkage (%), initial accuracy (%), and overlap rate (%) between the two laminations and the original model. The test results are shown in Table 1. The sample was then cleaned with alcohol and stored at room temperature for 3 days to verify its storage capacity. The test results are shown in Table 2.

[0149] Example 6:

[0150] The following provides Example 6. This example provides a photosensitive resin material for additive manufacturing, which is composed of the following components in parts by mass:

[0151] The raw materials for preparing the photosensitive resin for additive manufacturing are as follows, in parts by mass: 15 parts of difunctional modified acrylate oligomer (brand: CN983NS), 15 parts of difunctional modified acrylate oligomer (brand: GENOMER*4337), 38 parts of 4-tert-butylcyclohexyl acrylate, 28 parts of modified silicon-containing inorganic filler (brand: Schott glass powder-inert dental glass), 2 parts of 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, 2 parts of fumed silica (specific surface area of 120m 2 / g).

[0152] This commercially available silicon-containing inorganic filler (brand: Schott glass powder - inert dental glass) has its own degree of modification and does not require modification.

[0153] Preparation method: At room temperature and without strong light, place the active diluent and photoinitiator into a stirred tank and disperse them using a dispersing device at 800 rpm for 30 minutes. Then, add the aforementioned acrylate oligomer to the stirred tank and disperse them at room temperature at 500 rpm for 30-60 minutes. Add the modified silicon-containing inorganic filler (brand: Schott glass powder - inert dental glass) and fumed silica to the stirred tank and disperse them at room temperature at 500 rpm for 90 minutes. After stirring, filter the product using a 200-mesh filter cloth and bottle.

[0154] A Resai Edge E2 3D printer was used, and a curing technology using an LCD (the LCD screen was a 9.25-inch 6K black and white screen) radiation light source was adopted. The photosensitive resin material prepared by the above preparation method was poured into the resin tank of the 3D printing device. At normal room temperature (e.g., room temperature of 25±5°C) and normal humidity (e.g., 50±20%), the wavelength was 405nm, the layer thickness was 0.05mm, and the light intensity was 4mW / cm 2 3D printing is performed under the setting parameters of 75mm / h and a molding speed of 75mm / h. The sample of the 3D component completed by 3D printing is then placed in a 25-30℃ environment with a secondary curing light source (for example, in a curing box with a light source of 60mW / cm 2 , ultraviolet light with a wavelength of 405nm) for 10-60 minutes for secondary ultraviolet curing, and placed at normal room temperature (for example, room temperature of 25±5°C) and normal humidity conditions (for example, 50±20%) for 24 hours to obtain a 3D printed sample.

[0155] The sample was tested for its flexural strength (Mpa) and flexural modulus (Mpa), heat deformation temperature (HDT, ℃), volume shrinkage (%), initial accuracy (%), and overlap rate (%) between the two laminations and the original model. The test results are shown in Table 1. The sample was then cleaned with alcohol and stored at room temperature for 3 days to verify its storage capacity. The test results are shown in Table 2.

[0156] Comparative Example:

[0157] The following comparative example provides a photosensitive resin material for additive manufacturing, which is composed of the following components in parts by mass:

[0158] The raw materials for preparing the photosensitive resin for additive manufacturing are as follows, calculated by mass: 15 parts of trifunctional modified acrylate oligomer (brand: CN989 NS), 27 parts of difunctional modified acrylate oligomer (brand: GENOMER*4297), 20 parts of 4-tert-butylcyclohexyl acrylate, 35 parts of cyclotrimethylolpropane formal acrylate, and 3 parts of 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide.

[0159] Preparation method: At room temperature and without strong light, place the active diluent and photoinitiator into a stirred tank and disperse them at 800 rpm for 30 minutes using a dispersing device. Next, add the aforementioned acrylate oligomer to the stirred tank and disperse at room temperature at 500 rpm for 30-60 minutes. Add the fumed silica to the stirred tank and disperse at room temperature at 500 rpm for 90 minutes. After stirring, filter the product using a 200-mesh filter cloth and bottle. Preparation is complete.

[0160] A Resai Edge E2 3D printer was used, and a curing technology using an LCD (the LCD screen was a 9.25-inch 6K black and white screen) radiation light source was adopted. The photosensitive resin material prepared by the above preparation method was poured into the resin tank of the 3D printing device. At normal room temperature (e.g., room temperature of 25±5°C) and normal humidity (e.g., 50±20%), the wavelength was 405nm, the layer thickness was 0.05mm, and the light intensity was 4mW / cm 2 3D printing is performed under the setting parameters of 75mm / h and a molding speed of 75mm / h. The sample of the 3D component completed by 3D printing is then placed in a 25-30℃ environment with a secondary curing light source (for example, in a curing box with a light source of 60mW / cm 2 , ultraviolet light with a wavelength of 405nm) for 10-60 minutes for secondary ultraviolet curing, and placed at normal room temperature (for example, room temperature of 25±5°C) and normal humidity conditions (for example, 50±20%) for 24 hours to obtain a 3D printed sample.

[0161] The sample was tested for its flexural strength (Mpa) and flexural modulus (Mpa), heat deformation temperature (HDT, ℃), volume shrinkage (%), initial accuracy (%), and overlap rate (%) between the two laminations and the original model. The test results are shown in Table 1. The sample was then cleaned with alcohol and stored at room temperature for 3 days to verify its storage capacity. The test results are shown in Table 2.

[0162] The resins provided in the above Examples 1-6 and the comparative example were printed with reference to the method provided in the above application examples to obtain test samples of Examples 1 to 6 and the comparative example, and performance tests were performed with reference to the following methods and test standards:

[0163] 1. According to the requirements and test methods of 3.4 and 3.11 of GBT9341-2008 Plastics Bending Properties, the bending strength and bending modulus of the test samples of Examples 1 to 6 and the comparative example were tested respectively.

[0164] 2. According to the ASTM D648 plastic heat deformation temperature test method, the heat deformation temperatures of the test samples of Examples 1 to 6 and the comparative example were tested respectively.

[0165] 3. According to the test standard: GB / T 24148.9-2014 Plastics Unsaturated Polyester Resin (UP-R) Part 9 Determination of Total Volume Shrinkage, the volume shrinkage φ of the test samples of Examples 1 to 6 and the comparative example was tested respectively.

[0166] 4. Use a 3D scanner that meets the requirements of GB / T 39111 to reverse scan the prepared model to obtain its 3D scanning data. Use third-party 3D comparison software to compare the 3D scanning data with the original model, and calculate the initial accuracy and model accuracy, as well as the overlap rate of the two press molds, that is, the scanning accuracy (%).

[0167] The test results are shown in Table 1:

[0168] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example Bending strength (Mpa) 92.89 87.63 86.67 85.77 89.23 92.64 77.89 Flexural modulus (Mpa) 3983 3717 3524 3683 3787 4135 2117 HDT(℃) 119.1 110.5 104.8 103.1 114.2 123.2 84.8 Shrinkage (%) 3.9 4.3 4.7 4.7 4.6 3.5 7.2 Initial accuracy (%) 96 94 93 93 90 96 88 Compression molding twice (%) 88 86 86 85 87 91 73

[0169] Based on the test results presented in Table 1 above, it can be concluded that the photosensitive resin material prepared by adding the modified silicon-containing inorganic filler described in the present application, compared with the photosensitive resin material prepared in the comparative example without adding the modified silicon-containing inorganic filler described in the present application, can be tested to show that the performance of the photosensitive resin material for additive manufacturing described in the present application can reach bending strength: >80MPa; heat deformation temperature (HDT): >100°C; bending modulus: >3000MPa; volume shrinkage: <5%; initial model accuracy: 100μm is the scanning scale, and the overlap rate compared with the original model is >90%; model accuracy after two vacuum moldings: 100μm is the scanning scale, and the overlap rate compared with the original model is >85%.

[0170] The photosensitive resin materials provided in the above embodiments and comparative examples were printed with reference to the method provided in the above application examples to obtain test samples of Examples 1 to 6 and the comparative example, respectively. At the same time, the printing accuracy, temperature resistance, suitability for alcohol cleaning, and long-term storage of the photocurable 3D printing were tested. The test results are shown in Table 2.

[0171] The test results are shown in Table 2:

[0172] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example Heat resistance OK OK OK OK OK OK OK Alcohol cleaning OK OK OK OK OK OK OK Storage capacity OK OK OK OK OK OK OK

[0173] Based on the above results, it can be concluded that by adding the modified silicon-containing inorganic filler described in the present application, the photosensitive resin material of the present application is compared with the control example without adding the modified silicon-containing inorganic filler described in the present application. It can be seen from the test that the bending modulus and heat deformation temperature of the sample printed using the photosensitive resin material of the present application are significantly improved, so that it can withstand the mechanical stress and thermal load during multiple high-temperature vacuum molding of orthodontic braces; at the same time, as shown in the test data of Example 6 above, a high filler content (such as 30%) reduces the volume shrinkage rate to 3.5%, and improves the initial accuracy of the model to 96% by suppressing the curing deformation. After two moldings, it still maintains an accuracy of 91%, thereby solving the problem of inaccurate fitting of molded braces caused by low modulus and high shrinkage of traditional resins, and providing highly stable and low-cost production materials for digital orthodontic diagnosis and treatment.

[0174] The photosensitive resin material for additive manufacturing provided herein can be used in photocuring technology. The photosensitive resin material for additive manufacturing can typically undergo a polymerization reaction under conditions that trigger a free radical initiator and cure to form a molded object. The curing technology can include, but is not limited to, radiation curing technology, and more specifically, can include, but is not limited to, DLP photocuring technology and LCD photocuring technology.

[0175] The present application further provides a method for using a photosensitive resin material for additive manufacturing, comprising the following steps:

[0176] Step 1: The photosensitive resin material for additive manufacturing prepared by the above preparation method is introduced into the resin tank of the 3D printing device. At normal room temperature (e.g., room temperature of 20±5°C) and normal humidity conditions (e.g., 50±20%), the 3D printing device performs a 3D printing operation to solidify and shape the material to obtain a 3D component / model. The light source used in this process is 4mW / cm 2 , ultraviolet light with a wavelength of 405nm.

[0177] Step 2: The 3D printed 3D component / model is then placed in a secondary curing light source (e.g., in a curing box) at 25-30°C for 10-60 minutes for secondary UV curing, and then placed at normal room temperature (e.g., 25±5°C) and normal humidity (e.g., 50±20%) for 24 hours to obtain a light-cured model. The light source in this process is 60mW / cm 2 , ultraviolet light with a wavelength of 405nm.

[0178] The photosensitive resin material of the present application maintains dimensional stability under high-temperature vacuum conditions after digital sampling and 3D printing, significantly improving the success rate of molding and the accuracy of braces. Therefore, it can be specifically used in the vacuum molding process of orthodontic braces.

[0179] The present application prepares a photosensitive resin material by composite modification of a silicon-containing inorganic filler and then composite it with a resin matrix. The orthodontic mold prepared by a light-curing 3D printing process can achieve synergistic optimization of high HDT (heat deformation temperature (HDT): >100°C), high modulus (flexural modulus: >3000MPa) and high strength (flexural strength: >80MPa); at the same time, it reduces the shrinkage of the photosensitive resin (volume shrinkage rate <5%) and improves the printing accuracy (initial model accuracy: 100μm is the scanning scale, and the overlap rate compared with the original model is >90%). In particular, after two vacuum moldings, the model accuracy has an overlap rate of >85% compared with the original model, thereby being able to meet the application requirements of orthodontic molds for 3D printing model resins. That is to say, the photosensitive resin material of the present application maintains dimensional stability under high temperature vacuum conditions, significantly improves the success rate of molding and the accuracy of braces, and therefore can be specifically used in the vacuum molding process of orthodontic braces. After digital sampling and 3D printing, the photosensitive resin material can be used for vacuum molding to prepare orthodontic braces. Compared with plaster models, it can greatly improve production efficiency and reduce labor costs.

[0180] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. A photosensitive resin material for additive manufacturing, characterized in that: The photosensitive resin material includes: a resin matrix composed of 30%-60% by mass of an acrylate oligomer, 20%-50% by mass of a reactive diluent, and 1.5%-3% by mass of a photoinitiator, and 13%-30% by mass of a modified silicon-containing inorganic filler; wherein the modified silicon-containing inorganic filler contains silicon dioxide or silicate; and the particle size of the modified silicon-containing inorganic filler is 0.1-30 μm.

2. The photosensitive resin material for additive manufacturing according to claim 1, characterized in that: The acrylate oligomer includes one or more of polyester acrylate, polyether acrylate, polyurethane acrylate, and epoxy acrylate, and the resin functionality is 2-6.

3. The photosensitive resin material for additive manufacturing according to claim 1, characterized in that: The reactive diluent includes one or more of acryloylmorpholine, isobornyl acrylate, isobornyl methacrylate, 4-tert-butylcyclohexyl acrylate, lauryl acrylate, cyclic trimethylolpropane formal acrylate, tricyclodecane dimethanol diacrylate, phenoxyethyl acrylate, tripropylene glycol diacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, ethylene glycol dimethacrylate, 1,9-nonanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-ethylene glycol diacrylate, and dipropylene glycol diacrylate.

4. The photosensitive resin material for additive manufacturing according to claim 3, characterized in that: The mass fraction of the 4-tert-butylcyclohexyl acrylate is 20%-45%.

5. The photosensitive resin material for additive manufacturing according to claim 1, characterized in that: The photoinitiator includes one or more of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO), 2,4,6-trimethylbenzoyl-di(p-tolyl) phosphine oxide (TMO), phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide (819), methyl benzoylformate (MBF), and camphorquinone (CQ).

6. The photosensitive resin material for additive manufacturing according to claim 5, characterized in that: The mass fraction of the 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide is 1.5%-3%.

7. The photosensitive resin material for additive manufacturing according to claim 1, characterized in that: The modified silicon-containing inorganic filler comprises a silicon-containing inorganic filler and fumed silica with a mass fraction of 1.0% to 5%.

8. The photosensitive resin material for additive manufacturing according to claim 7, characterized in that: The fumed silica has a specific surface area of 120 m 2 / g of fumed silica.

9. The photosensitive resin material for additive manufacturing according to claim 7, characterized in that: The modified silicon-containing inorganic filler is prepared by surface-modifying the silicon-containing inorganic filler with a silane coupling agent.

10. The photosensitive resin material for additive manufacturing according to claim 9, characterized in that: The modified silicon-containing inorganic filler is obtained by sequentially adding the silicon-containing inorganic filler and the silane coupling agent into an ethanol-water mixture, adjusting the pH value to 3.5-4 with dilute acid, and then drying.

11. The photosensitive resin material for additive manufacturing according to claim 10, characterized in that: The ethanol-water mixed liquid is formed by dispersing 20%-40% ethanol by mass and 60%-80% pure water by mass.

12. The photosensitive resin material for additive manufacturing according to claim 10, characterized in that: The mass fraction of the silane coupling agent to the silicon-containing inorganic filler is 1%-5%.

13. The photosensitive resin material for additive manufacturing according to claim 10, characterized in that: The silane coupling agent includes one of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS), or a mixture of the two.

14. A method for preparing a photosensitive resin material for additive manufacturing, characterized in that: The preparation method comprises the following steps: At room temperature, add 20%-50% by mass of active diluent and 1.5%-3% by mass of photoinitiator into a stirring kettle, and use a dispersing device to disperse at a speed of 500-1000 r / min for 30-60 minutes; Adding 30% to 60% by mass of an acrylate oligomer into the stirred tank and continuing to disperse at a speed of 500 to 1000 r / min for 30 to 60 minutes using the dispersing device to obtain a resin matrix; Adding 13% to 30% by mass of a modified silicon-containing inorganic filler into the resin matrix and continuing to disperse it at a speed of 500 to 1000 r / min for 60 to 90 minutes using the dispersion equipment; wherein the modified silicon-containing inorganic filler comprises silicon dioxide or silicate; and the particle size of the modified silicon-containing inorganic filler is 0.1 to 30 μm; After stirring, filter with 200 mesh filter cloth and the resulting photosensitive resin material can be used for filling.

15. The preparation method according to claim 14, characterized in that The modified silicon-containing inorganic filler comprises a silicon-containing inorganic filler and fumed silica with a mass fraction of 1.0% to 5%.

16. The preparation method according to claim 15, characterized in that The fumed silica has a specific surface area of 120 m 2 / g of fumed silica.

17. The preparation method according to claim 15, characterized in that The method further comprises the steps of preparing the silicon-containing inorganic filler into a modified silicon-containing inorganic filler: Add the silicon-containing inorganic filler to the pre-made modified liquid and perform ultrasonic dispersion for 10-25 minutes until the silicon-containing inorganic filler is uniformly suspended; A silane coupling agent is added according to 1%-5% of the mass of the silicon-containing inorganic filler, and then a diluted acetic acid solution is added to adjust the pH value to 3.5-4.0, and a dispersion device is used to stir the dispersion machine at a speed of 800-1200 r / min for 30-90 minutes; after filtering, it is placed in an 80°C oven and dried for 2 hours to obtain the modified silicon-containing inorganic filler.

18. The preparation method according to claim 17, characterized in that: The modified liquid is formed by mixing ethanol water formed by dispersing 20%-40% ethanol and 60%-80% pure water.

19. The preparation method according to claim 17, characterized in that The mass fraction of the silane coupling agent to the silicon-containing inorganic filler is 1%-5%.

20. The preparation method according to claim 17, characterized in that The silane coupling agent includes one of 3-methacryloxypropyltrimethoxysilane (MPS) and vinyltrimethoxysilane (VTMS), or a mixture of the two.

21. A resin product formed by curing the photosensitive resin material according to any one of claims 1 to 13.

22. A product produced by 3D printing using the photosensitive resin material according to any one of claims 1 to 13.

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