Preparation method of branched chain fluorine-containing polyurethane acrylate and application of branched chain fluorine-containing polyurethane acrylate in 3D printing photosensitive resin composition
By preparing branched fluorinated polyurethane acrylate, the problem of insufficient precision of dental 3D printing materials in high temperature, high pressure and water vapor environments was solved, and the high precision, temperature resistance and water resistance were improved, ensuring the stability and strength of the dental model.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-25
- Publication Date
- 2026-04-07
AI Technical Summary
Existing dental 3D printing materials are insufficient in precision, have poor temperature resistance, weak water resistance and low strength in high temperature, high pressure and water vapor environments, making it difficult to accurately reproduce the complex anatomical morphology of teeth and jawbones, and are prone to deformation or chemical degradation during high temperature water vapor washing.
A method for preparing branched fluorinated polyurethane acrylates was adopted, which involves acylation of perfluorocarboxylic acid with aminobutanediol, followed by polymerization with diisocyanate and dropwise addition of acrylate end-capping agent to prepare branched fluorinated polyurethane acrylates with benzene ring-rich main chain, which can be used for 3D printing photosensitive resin compositions.
It improves the precision stability and mechanical strength of 3D printing materials in high temperature, high pressure and water vapor environments, ensuring the high precision, temperature resistance and water resistance of dental models, avoiding warping and shrinkage, and extending service life.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of 3D printing technology, specifically to a method for preparing branched fluorinated polyurethane acrylate and its application in 3D printing photosensitive resin compositions. Background Technology
[0002] In recent years, the rapid development of digital and 3D printing technologies has injected new vitality into the field of dental restoration, propelling oral healthcare into the digital age. In the dental restoration process, traditional methods rely on manual manufacturing for stages such as dental model creation, orthodontic treatment planning, precise design of implant guides, and efficient denture fabrication. This results in long production cycles, complex procedures, and insufficient precision. Leveraging the digital advantages of 3D printing, the production process has been significantly simplified, allowing patients to enjoy a more comfortable, faster, and safer treatment experience.
[0003] 3D printing uses a specific wavelength light source to catalyze the curing of resin through exposure, achieving precise stacking and forming of three-dimensional structures. This process places stringent requirements on specialized photosensitive resin materials—they must possess ideal rheological properties to ensure uniform liquid spreading, while also exhibiting rapid light response, strong penetration, high hardness, low shrinkage, and excellent dimensional stability.
[0004] In the diverse applications of dentistry, material properties must be precisely matched. The core of thermoformed dental tray manufacturing lies in the process of heating and softening a plastic sheet, then vacuum-forming it onto a dental model. This process requires the dental model to maintain excellent precision under the harsh environment of high temperature and high pressure. Furthermore, given that the dental model needs to be rinsed with high-temperature steam in the early stages, it must possess the ability to continuously maintain high precision under the combined effects of high temperature and steam.
[0005] Current materials have common defects: significant shrinkage and warping after resin curing limits the accuracy of models and makes it difficult to accurately reproduce the complex anatomical morphology of teeth and jawbones; insufficient mechanical strength makes them unable to withstand high temperature and high pressure, resulting in deformation and inability to accurately represent the real state of teeth; and they are prone to deformation, softening, or even chemical degradation when in contact with water or other bodily fluids, seriously threatening the stability and service life of the products. Summary of the Invention
[0006] This invention provides a branched fluorinated polyurethane acrylate for use in photocurable 3D printing resin compositions, thereby solving the technical problems of insufficient precision, poor temperature resistance, weak water resistance, and low strength in existing dental 3D printing models.
[0007] In view of this, the solution of the present invention is as follows: The first aspect of the present invention is to provide a method for preparing branched fluorinated polyurethane acrylates, comprising: S1. Fluorinated branched ethylene glycol is prepared by acylation of perfluorocarboxylic acid and aminobutanediol under solvent 1 and catalyst 1 conditions. S2. After removing the water from the fluorinated branched diol, add diisocyanate, catalyst II, and solvent II, and polymerize under stirring to obtain the prepolymer; S3. Add an acrylate end-capping agent dropwise to the prepolymer system obtained in step S2 and react until the NCO reaction is complete. After separation and drying, branched fluorinated polyurethane acrylate is obtained.
[0008] Further, in step S1, the general formula of the perfluorocarboxylic acid is CnF2n+1COOH, where n is an integer between 4 and 16.
[0009] Furthermore, in step S1: The solvent is selected from one of tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, dichloromethane, and N,N-dimethylformamide; And / or, the catalyst is selected from one or two of N,N'-dicyclohexylcarbodiimide, 1-hydroxybenzotriazole, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 2,4-bis(trifluoromethyl)phenylboronic acid, hexafluorophosphate, and N,N'-carbonyldiimidazole; And / or, the molar ratio of the perfluorocarboxylic acid to aminobutanediol and the catalyst is 1:(1~1.2):(1~1.3). And / or, the acylation reaction temperature is -5~25℃.
[0010] Furthermore, in step S2: The aromatic diisocyanate is selected from one or more of the following structures: , , , , , ; And / or, the catalyst 2 is selected from one of dibutyltin dilaurate, stannous octoate, di(dodecyl sulfide)dibutyltin, dibutyltin diacetate, triethylamine, and N,N-dimethylethanolamine; And / or, the solvent 2 is selected from one or more of N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, toluene, xylene, dichloromethane, chloroform, 1,2-dichloroethane, and tetrahydrofuran; And / or, the molar ratio of the fluorinated branched diol to the diisocyanate and catalyst II is 1:(1.5~4):(0.005~0.01).
[0011] Further, in step S3, the acrylate end-capping agent is selected from one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and 2-hydroxyethyl methacrylate.
[0012] A second aspect of the present invention is to provide a branched fluorinated polyurethane acrylate, prepared by the method described in the first aspect.
[0013] A third aspect of the present invention is to provide a 3D printing photosensitive resin composition, comprising, by weight: 20-50 parts of branched fluorinated polyurethane acrylate, 0-20 parts of polyurethane acrylate, 30-60 parts of photocurable monomer, 1-5 parts of photoinitiator, and 0-0.5 parts of colorant; wherein the branched fluorinated polyurethane acrylate is prepared by the preparation method described in the first aspect.
[0014] Furthermore, in the above resin composition: The polyurethane acrylate is selected from one or more of aliphatic polyurethane acrylate oligomers, aromatic polyurethane acrylate oligomers, polyurethane diacrylate, and dimethacrylate urethane; And / or, the photocurable monomer is selected from one or more of ethylene glycol diacrylate, 1,6-ethylene glycol diacrylate, dipropylene glycol diacrylate, propoxylated neopentyl glycol diacrylate, pentaerythritol triacrylate, tricyclodecanedimethyl diacrylate, dipropylene glycol diacrylate, and acryloylmorpholine; And / or, the photoinitiator is one or more of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, benzoin dimethyl ether, and 1-hydroxycyclohexylphenyl ketone.
[0015] A fourth aspect of the present invention is to provide a 3D printed article obtained by photocuring the resin composition described in the third aspect after 3D printing.
[0016] A fifth aspect of the present invention is to provide a dental model which is obtained by curing the resin composition described in the third aspect after 3D printing, or by making the 3D printed article described in the fourth aspect.
[0017] Compared with the prior art, the present invention has the following beneficial effects: The branched fluorinated polyurethane acrylate provided by this invention has a main chain rich in benzene rings and is fluorine-free, ensuring strength, temperature resistance, and pressure resistance. The presence of fluorine in the branches enhances its water resistance in addition to its excellent temperature and pressure resistance. As a bifunctional polyurethane acrylate, it ensures moderate photocuring reactivity and is less prone to warping and shrinkage, making it suitable for use in dental 3D printing photocurable compositions to effectively address various performance issues such as precision, temperature resistance, water resistance, and strength.
[0018] The 3D printing photosensitive resin composition provided by this invention uses branched fluorinated polyurethane acrylate, thus exhibiting high curing and molding precision. Even in high temperature, high pressure and water vapor environments, it can maintain excellent precision stability and has significant application prospects. Detailed Implementation
[0019] The technical solution of the present invention will now be clearly and completely described in conjunction with preferred embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0020] In one embodiment, a method for preparing branched fluorinated polyurethane acrylate is provided as follows: 1. Preparation of fluorinated branched diols In a three-necked flask, perfluorocarboxylic acid, 2-amino-2-methyl-1,3-propanediol (aminobutanediol), a catalyst, and an appropriate amount of solvent are added. The mixture is cooled to 0°C in an ice bath to induce an acylation reaction. The mixture is then allowed to naturally warm to room temperature. After reacting for 24 hours, the precipitate is removed by filtration. The mixture is concentrated under reduced pressure to remove the solvent. It is then dissolved in ethyl acetate, and excess 2-methyl-amino-1,3-propanediol is washed away with dilute hydrochloric acid. The mixture is concentrated under reduced pressure to remove the ethyl acetate, and a small amount of petroleum ether is added to seal the flask. The mixture is then frozen to crystallize, yielding the desired fluorinated branched diol.
[0021] Preferably, the catalyst is one or two of N,N'-dicyclohexylcarbodiimide, 1-hydroxybenzotriazole, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 2,4-bis(trifluoromethyl)phenylboronic acid, hexafluorophosphate, and N,N'-carbonyldiimidazole. When the catalyst is a mixture of two catalysts, the molar ratio of the two catalysts is 1:1. Preferably, the solvent is one of tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, dichloromethane, and N,N-dimethylformamide.
[0022] Preferably, the perfluorocarboxylic acid has the structural formula C0. n F 2n+1 COOH, 4≤n≤16; Preferably, the molar ratio of the perfluorocarboxylic acid, 2-amino-2-methyl-1,3-propanediol, and the catalyst is 1:1:1 to 1:1.2:1.3.
[0023] Step 2: Preparation of branched fluorinated polyurethane acrylate
[0024] Fluorinated branched diols were heated under vacuum to remove moisture. Aromatic diisocyanates, catalysts, and solvents were added under N2 atmosphere, and the mixture was continuously stirred to induce polymerization and obtain a prepolymer. The resulting product was further mixed thoroughly, protected with N2, and kept at 60°C. An acrylate-based end-capping agent was added dropwise, and infrared spectroscopy was used until the NCO characteristic peak disappeared. The resulting product was washed sequentially with ethanol and diethyl ether to remove unreacted raw materials, and then dried under vacuum to obtain branched fluorinated polyurethane acrylate.
[0025] Preferably, the aromatic diisocyanate is selected from one or more of the following structures: , , , , , ; Preferably, the catalyst is selected from one of dibutyltin dilaurate, stannous octoate, di(dodecyl sulfide)dibutyltin, dibutyltin diacetate, triethylamine, and N,N-dimethylethanolamine.
[0026] Preferably, the solvent is selected from one or more mixtures of N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, toluene, xylene, dichloromethane, chloroform, 1,2-dichloroethane, and tetrahydrofuran.
[0027] Preferably, the acrylate capping agent is an acrylate containing capping groups, including but not limited to one or more mixtures of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and 2-hydroxyethyl methacrylate.
[0028] Preferably, the molar ratio of the fluorinated branched diol to the diisocyanate is 1:1.5-1:4.
[0029] Preferably, the molar ratio of the fluorinated branched diol to the catalyst is 1:0.005-1:0.01.
[0030] In the above embodiments, the branched fluorinated polyurethane acrylate obtained by the preparation method has a main chain rich in benzene rings and is fluorine-free, ensuring strength, temperature resistance, and pressure resistance. The presence of fluorine in the branches enhances water resistance on top of its excellent temperature and pressure resistance. As a bifunctional polyurethane acrylate, it ensures moderate photocuring reactivity and is less prone to warping and shrinkage, making it suitable for use in dental 3D printing photocurable compositions to effectively address various performance issues such as precision, temperature resistance, water resistance, and strength.
[0031] In some embodiments, taking perfluorooctanoic acid, isophthalic diisocyanate, and hydroxypropyl acrylate as examples, the specific synthetic routes are as follows:
[0032] In another embodiment, a temperature-resistant, pressure-resistant, water-resistant, and high-precision 3D printing photosensitive resin composition is provided, which is prepared from the following raw materials in parts by weight: 20-50 parts by weight of branched fluorinated polyurethane acrylate, 0-20 parts by weight of ordinary polyurethane acrylate, 30-60 parts by weight of photocurable monomer, 1-5 parts by weight of photoinitiator, and 0-0.5 parts by weight of colorant.
[0033] The 3D printing photosensitive resin composition provided in the above embodiments uses branched fluorinated polyurethane acrylate, thus having high curing and molding precision, and maintaining excellent precision stability even in high temperature, high pressure and water vapor environments.
[0034] In a preferred embodiment, the common polyurethane acrylate is selected from one or more of aliphatic polyurethane acrylate oligomers, aromatic polyurethane acrylate oligomers, polyurethane diacrylate, and dimethacrylate urethane; the photocurable monomer is selected from one or more of ethylene glycol diacrylate, 1,6-ethylene glycol diacrylate, dipropylene glycol diacrylate, propoxylated neopentyl glycol diacrylate, pentaerythritol triacrylate, tricyclodecanedimethyl diacrylate, dipropylene glycol diacrylate, and acryloylmorpholine; the photoinitiator is one or more of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, benzoin dimethyl ether, and 1-hydroxycyclohexylphenyl ketone.
[0035] In another embodiment, a 3D printed dental model is provided, which is obtained by 3D printing and photocuring of the above-described 3D printing photosensitive resin composition. In a preferred embodiment, the performance of the 3D-printed dental model is as follows: 1) The accuracy of the machine is above 96.5%, preferably above 97%; 2) The boiling accuracy reaches 90% or higher, preferably 95% or higher; 3) The hot pressing accuracy reaches 91% or higher, preferably 94% or higher; 4) The hardness HD is 85 or higher, preferably 90 or higher.
[0036] The aforementioned 3D printed dental model solves the technical problems of insufficient precision, poor temperature resistance, weak water resistance, and low strength of existing printed models.
[0037] Example 1
[0038] In a 500 ml three-necked flask, add 41.40 g of perfluorooctanoic acid (0.10 mol), 11.03 g of 2-amino-2-methyl-1,3-propanediol (0.105 mol), and 8.10 g of 1-hydroxybenzotriazole (0.06 mol), then add 300 ml of tetrahydrofuran. Cool to 0 °C in an ice bath, add 12.36 g of N,N-dicyclohexylcarbodiimide (0.06 mol), react, and allow to warm naturally to room temperature. After reacting for 24 h, filter to remove the precipitate, concentrate under reduced pressure to remove tetrahydrofuran, dissolve in ethyl acetate, wash away excess 2-amino-2-methyl-1,3-propanediol with dilute hydrochloric acid, concentrate under reduced pressure to remove ethyl acetate, add a small amount of petroleum ether, seal, and freeze to crystallize to obtain the desired fluorinated branched diol.
[0039] 50.12 g of fluorinated branched diol (0.10 mol) was vacuum-treated at 100 °C for 1 hour to remove moisture. When the system temperature dropped to 80 °C, N2 was introduced, followed by the addition of 48.03 g of isophthalic acid diisocyanate (0.30 mol), 0.06 g of catalyst dibutyltin dilaurate (0.001 mol), and 100 ml of N,N-dimethylacetamide solvent. The mixture was stirred continuously for 2 hours to obtain a prepolymer. The product was then stirred until homogeneous under N2 conditions and kept at 60 °C. Hydroxypropyl acrylate was added dropwise, and infrared spectroscopy was used until the NCO characteristic peak disappeared. The product was washed sequentially with ethanol and diethyl ether to remove unreacted raw materials, and then vacuum-dried at 80 °C for 12 hours to obtain branched fluorinated polyurethane acrylate.
[0040] Take 20 parts by weight of the prepared branched fluorinated polyurethane acrylate, 17 parts by weight of ordinary polyurethane acrylate, 60 parts by weight of the photocurable monomer, 3 parts by weight of the photoinitiator, and 0 parts by weight of the color paste. Stir evenly at room temperature, let stand to defoam, and obtain a photosensitive resin composition.
[0041] The photocurable monomers are 30 parts by weight of dipropylene glycol diacrylate and 30 parts by weight of acrylamide morpholine.
[0042] Example 2
[0043] In a 500 ml three-necked flask, add 36.41 g of perfluoroheptanoic acid (0.10 mol), 10.50 g of 2-amino-2-methyl-1,3-propanediol (0.10 mol), and 6.75 g of 1-hydroxybenzotriazole (0.05 mol). Then add 300 ml of tetrahydrofuran, cool to 0 °C in an ice bath, add 10.30 g of N,N-dicyclohexylcarbodiimide (0.05 mol), react, and allow to warm naturally to room temperature. After reacting for 24 h, filter to remove the precipitate, concentrate under reduced pressure to remove tetrahydrofuran, dissolve in ethyl acetate, wash away excess 2-amino-2-methyl-1,3-propanediol with dilute hydrochloric acid, concentrate under reduced pressure to remove ethyl acetate, add a small amount of petroleum ether, seal, and freeze to crystallize to obtain the desired fluorinated branched diol.
[0044] 49.82 g of fluorinated branched diol (0.10 mol) was vacuum-treated at 100 °C for 1 hour to remove moisture. When the system temperature dropped to 80 °C, N2 was introduced, followed by the addition of 48.03 g of terephthalic diisocyanate (0.30 mol), 0.04 g of stannous octoate catalyst (0.001 mol), and 100 ml of N,N-dimethylformamide solvent. The mixture was stirred continuously for 2 hours to obtain a prepolymer. The product was then stirred until homogeneous under N2 conditions and kept at 60 °C. Hydroxyethyl acrylate was added dropwise, and infrared spectroscopy was used until the NCO characteristic peak disappeared. The product was washed sequentially with ethanol and diethyl ether to remove unreacted raw materials, and then vacuum-dried at 80 °C for 12 hours to obtain branched fluorinated polyurethane acrylate.
[0045] Take 30 parts by weight of the prepared branched fluorinated polyurethane acrylate, 20 parts by weight of ordinary polyurethane acrylate, 48.5 parts by weight of the photocurable monomer, 1 part by weight of the photoinitiator, and 0.5 parts by weight of the color paste. Stir evenly at room temperature, let stand to defoam, and obtain the photosensitive resin composition.
[0046] The photocurable monomers are 20 parts by weight of dipropylene glycol diacrylate and 28.5 parts by weight of acryloylmorpholine.
[0047] Example 3
[0048] In a 500 ml three-necked flask, add 61.41 g of perfluorododecanoic acid (0.10 mol), 12.61 g of 2-amino-2-methyl-1,3-propanediol (0.12 mol), and 300 ml of dichloromethane. Cool to 0 °C in an ice bath, then add 12.62 g of N,N'-diisopropylcarbodiimide (0.10 mol). React and allow to warm naturally to room temperature. After reacting for 24 h, filter to remove the precipitate, concentrate under reduced pressure to remove dichloromethane, dissolve in ethyl acetate, wash away excess 2-amino-2-methyl-1,3-propanediol with dilute hydrochloric acid, concentrate under reduced pressure to remove ethyl acetate, add a small amount of petroleum ether, seal, and freeze to crystallize to obtain the desired fluorinated branched diol.
[0049] 51.02 g of fluorinated branched diol (0.10 mol) was vacuum-treated at 100 °C for 1 hour to remove moisture. When the system temperature dropped to 80 °C, N2 was introduced, followed by the addition of 50.05 g of xylene diisocyanate (0.20 mol), 0.40 g of stannous octoate catalyst (0.01 mol), and 100 ml of toluene solvent. The mixture was stirred continuously for 2 hours to obtain a prepolymer. The product was then stirred until homogeneous under N2 conditions and kept at 60 °C. Hydroxyethyl methacrylate was added dropwise, and infrared spectroscopy was used until the NCO characteristic peak disappeared. The product was washed sequentially with ethanol and diethyl ether to remove unreacted raw materials, and then vacuum-dried at 80 °C for 12 hours to obtain branched fluorinated polyurethane acrylate.
[0050] Take 40 parts by weight of the prepared branched fluorinated polyurethane acrylate, 15 parts by weight of ordinary polyurethane acrylate, 41.7 parts by weight of the photocurable monomer, 3 parts by weight of the photoinitiator, and 0.3 parts by weight of the color paste. Stir evenly at room temperature, let stand to defoam, and obtain the photosensitive resin composition.
[0051] The photocurable monomers are 21.7 parts by weight of dipropylene glycol diacrylate and 20 parts by weight of acrylamide morpholine.
[0052] Example 4
[0053] In a 500 ml three-necked flask, add 61.41 g of perfluorododecanoic acid (0.10 mol), 10.51 g of 2-amino-2-methyl-1,3-propanediol (0.10 mol), and 300 ml of dichloromethane. Cool to 0 °C in an ice bath, then add 12.62 g of N,N'-diisopropylcarbodiimide (0.10 mol). React and allow to warm naturally to room temperature. After reacting for 24 h, filter to remove the precipitate, concentrate under reduced pressure to remove dichloromethane, dissolve in ethyl acetate, wash away excess 2-amino-2-methyl-1,3-propanediol with dilute hydrochloric acid, concentrate under reduced pressure to remove ethyl acetate, add a small amount of petroleum ether, seal, and freeze to crystallize to obtain the desired fluorinated branched diol.
[0054] 51.02 g of fluorinated branched diol (0.10 mol) was vacuum-treated at 100 °C for 1 hour to remove moisture. When the system temperature dropped to 80 °C, N2 was introduced, followed by the addition of 69.66 g of toluene-2,4-diisocyanate (0.40 mol), 0.40 g of stannous octoate catalyst (0.01 mol), and 150 ml of tetrahydrofuran solvent. The mixture was stirred continuously for 2 hours to obtain a prepolymer. The product was then stirred until homogeneous under N2 conditions and kept at 60 °C. Hydroxybutyl acrylate was added dropwise, and infrared spectroscopy was used until the NCO characteristic peak disappeared. The product was washed sequentially with ethanol and diethyl ether to remove unreacted raw materials, and then vacuum-dried at 80 °C for 12 hours to obtain branched fluorinated polyurethane acrylate.
[0055] Take 46 parts by weight of the prepared branched fluorinated polyurethane acrylate, 20 parts by weight of ordinary polyurethane acrylate, 30 parts by weight of the photocurable monomer, 3.8 parts by weight of the photoinitiator, and 0.2 parts by weight of the color paste. Stir evenly at room temperature, let stand to defoam, and obtain a photosensitive resin composition.
[0056] The photocurable monomers are 13 parts by weight of dipropylene glycol diacrylate and 17 parts by weight of acrylamide morpholine.
[0057] Example 5
[0058] Take 50 parts by weight of the branched fluorinated polyurethane acrylate prepared in Example 1, 5 parts by weight of ordinary polyurethane acrylate, 42.6 parts by weight of photocurable monomer, 2 parts by weight of photoinitiator, and 0.4 parts by weight of color paste. Stir evenly at room temperature, let stand to defoam, and obtain a photosensitive resin composition.
[0059] The photocurable monomers are 25 parts by weight of dipropylene glycol diacrylate and 17.6 parts by weight of acrylamide morpholine.
[0060] Example 6
[0061] Take 45 parts by weight of the branched fluorinated polyurethane acrylate prepared in Example 2, 49.8 parts by weight of the photocurable monomer, 5 parts by weight of the photoinitiator, and 0.2 parts by weight of the color paste. Stir evenly at room temperature and let stand to defoam to obtain a photosensitive resin composition.
[0062] The photocurable monomers are 25 parts by weight of dipropylene glycol diacrylate and 24.8 parts by weight of acrylamide morpholine.
[0063] Example 7
[0064] Take 36.6 parts by weight of the branched fluorinated polyurethane acrylate prepared in Example 3, 60 parts by weight of the photocurable monomer, 3 parts by weight of the photoinitiator, and 0.4 parts by weight of the color paste. Stir evenly at room temperature and let stand to defoam to obtain a photosensitive resin composition.
[0065] The photocurable monomers are 30 parts by weight of dipropylene glycol diacrylate and 30 parts by weight of acrylamide morpholine.
[0066] Comparative Example 1
[0067] 45 parts by weight of ordinary polyurethane acrylate, 52.6 parts by weight of photocurable monomer, 2 parts by weight of photoinitiator, and 0.4 parts by weight of colorant were mixed evenly at room temperature and allowed to stand to defoam, thus obtaining a photosensitive resin composition.
[0068] The photocurable monomers are 30 parts by weight of dipropylene glycol diacrylate and 22.6 parts by weight of acrylamide morpholine.
[0069] Comparative Example 2
[0070] Compared with Example 1, in Comparative Example 2, 48.03g of isophthalic diisocyanate was replaced with 50.46g of hexamethylene diisocyanate (0.30mol), and the remaining steps and components were the same as in Example 1.
[0071] Comparative Example 3
[0072] Compared with Example 1, in Comparative Example 3, 41.40g of perfluorooctanoic acid (0.10mol) was replaced with 16.40g of pentafluoropropionic acid (0.10mol), and 50.12g of fluorinated branched diol (0.10mol) was changed to 25.10g of fluorinated branched diol (0.10mol). The remaining steps and components were the same as in Example 1.
[0073] The common polyurethane acrylate mentioned in Examples 1-7 and Comparative Example 1 is Sartoma CN991NS, the photoinitiator is (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and the color paste is a gray color obtained by compounding Jiangxi Xiyan R2885 and exp8002 in a ratio of 65:1.
[0074] The photosensitive resin compositions prepared in Examples 1-7 and Comparative Examples 1-3 were poured into the resin tank of a 3D printer and printed. Tooth models were printed and post-processed. The accuracy and surface hardness of the tooth models were tested. The 3D printer model was a UnionTech E120, the printing exposure power was 400μw, and the exposure time was the time required for each material to cure a single layer thickness of 0.15mm. Post-processing involved first cleaning the liquid resin on the surface of the tooth model with alcohol, then curing it for 10 minutes in a UnionTech PCU400 curing chamber to harden the surface.
[0075] Accuracy testing methods: The printed tooth model was scanned using a 3D scanner to obtain a reverse-scan accuracy model. Using the comparison software Geomagic Qualify, the reverse-scan accuracy model was "best fit alignment" with the original printed model, and "3D deviation analysis" was performed to obtain the overlap rate value within ±0.05mm of the deviation between the two models. A higher overlap rate value indicates higher accuracy of the printed model, named "off-machine accuracy." The printed tooth model was boiled in 100℃ water for 1 hour and then compared with the model before boiling to obtain the overlap rate value within ±0.05mm of the deviation between the two models. A higher overlap rate value indicates higher accuracy retention rate after boiling, named "boiling accuracy." The printed tooth model was kept at 70℃ and 300kPa pressure for 0.5 hours and then compared with the model before treatment to obtain the overlap rate value within ±0.05mm of the deviation between the two models. A higher overlap rate value indicates higher accuracy retention rate after heating and pressurizing, named "hot-pressing accuracy."
[0076] Surface hardness test method: Refer to GB / T 2411-2008 standard for testing, use a Shore hardness tester to test the surface hardness of the printed tooth model.
[0077] Table 1: Comparative Test Data of Examples
[0078] As can be seen from Table 1 above: The test data of Comparative Example 1 show that the photosensitive resin composition formulated with ordinary polyurethane acrylate can also achieve relatively high accuracy in the machine, but the accuracy retention rate of the tooth model during boiling and hot pressing is very low.
[0079] Compared with Example 1, Comparative Example 2 shows that although fluorinated branched polyurethane was introduced in Comparative Example 2, the main chain of the fluorinated branched polyurethane used did not contain a benzene ring structure. The overall hardness of the photosensitive resin composition after curing was not high, and it was easy to deform during boiling and hot pressing, resulting in a very low accuracy retention rate of the tooth model during boiling and hot pressing.
[0080] Compared with Example 1, Comparative Example 3 shows that although fluorinated branched polyurethane was introduced in Comparative Example 3, the branches in the fluorinated branched polyurethane used were too short and the fluorine content was low. Although the hot pressing accuracy was very high, the boiling water accuracy was still not ideal.
[0081] Test data from Examples 1-7 show that after introducing the branched fluorinated polyurethane acrylate provided by this invention into the photosensitive resin composition, the tooth model exhibits excellent precision upon machine application, indicating that the reaction rate of the branched fluorinated polyurethane acrylate is just right, without causing significant shrinkage or warping. The tooth model demonstrates excellent precision upon boiling, indicating its superior temperature and water resistance. Its excellent hot-pressing precision further demonstrates its superior temperature and pressure resistance. Compared to Comparative Examples 1-3, the surface hardness of the tooth model did not decrease, indicating that although the branched fluorinated polyurethane acrylate provided by this invention introduces fluorinated branches, it does not weaken the hardness of the polyurethane itself.
[0082] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preparing branched fluorinated polyurethane acrylate, characterized in that, include: S1. Fluorinated branched ethylene glycol is prepared by acylation of perfluorocarboxylic acid and aminobutanediol under solvent 1 and catalyst 1 conditions. S2. After removing the water from the fluorinated branched diol, add the aromatic diisocyanate, catalyst 2, and solvent 2, and the polymerization reaction occurs under stirring to obtain the prepolymer; S3. Add an acrylate end-capping agent dropwise to the prepolymer system obtained in step S2 and react until the NCO reaction is complete. After separation and drying, branched fluorinated polyurethane acrylate is obtained.
2. The preparation method according to claim 1, characterized in that, In step S1, the perfluorocarboxylic acid has the general formula C1 n F 2n+ 1COOH, where n is an integer between 4 and 16.
3. The preparation method according to claim 1, characterized in that, In step S1, the solvent is selected from one of tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, dichloromethane, and N,N-dimethylformamide; And / or, the catalyst is selected from one or two of N,N'-dicyclohexylcarbodiimide, 1-hydroxybenzotriazole, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 2,4-bis(trifluoromethyl)phenylboronic acid, hexafluorophosphate, and N,N'-carbonyldiimidazole; And / or, the molar ratio of the perfluorocarboxylic acid to aminobutanediol and the catalyst is 1:(1~1.2):(1~1.3). And / or, the acylation reaction temperature is -5~25℃.
4. The preparation method according to claim 1, characterized in that, In step S2, the aromatic diisocyanate is selected from one or more of the following structures: 、 、 、 、 、 ； And / or, the catalyst 2 is selected from one of dibutyltin dilaurate, stannous octoate, di(dodecyl sulfide)dibutyltin, dibutyltin diacetate, triethylamine, and N,N-dimethylethanolamine; And / or, the solvent 2 is selected from one or more of N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, toluene, xylene, dichloromethane, chloroform, 1,2-dichloroethane, and tetrahydrofuran; And / or, the molar ratio of the fluorinated branched diol to the diisocyanate and catalyst II is 1:(1.5~4):(0.005~0.01).
5. The preparation method according to claim 1, characterized in that, In step S3, the acrylate end-capping agent is selected from one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and 2-hydroxyethyl methacrylate.
6. A branched fluorinated polyurethane acrylate, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 5.
7. A 3D printing photosensitive resin composition, characterized in that, The components, by weight, include: 20-50 parts of branched fluorinated polyurethane acrylate, 0-20 parts of polyurethane acrylate, 30-60 parts of photocurable monomer, 1-5 parts of photoinitiator, and 0-0.5 parts of colorant; wherein the branched fluorinated polyurethane acrylate is prepared by the preparation method according to any one of claims 1-5.
8. The 3D printing photosensitive resin composition according to claim 7, characterized in that, The polyurethane acrylate is selected from one or more of aliphatic polyurethane acrylate oligomers, aromatic polyurethane acrylate oligomers, polyurethane diacrylate, and dimethacrylate urethane; And / or, the photocurable monomer is selected from one or more of ethylene glycol diacrylate, 1,6-ethylene glycol diacrylate, dipropylene glycol diacrylate, propoxylated neopentyl glycol diacrylate, pentaerythritol triacrylate, tricyclodecanedimethyl diacrylate, dipropylene glycol diacrylate, and acryloylmorpholine; And / or, the photoinitiator is one or more of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, benzoin dimethyl ether, and 1-hydroxycyclohexylphenyl ketone.
9. A 3D printed product, characterized in that, The resin composition of claim 7 or 8 is obtained by photocuring after 3D printing.
10. A dental model, characterized in that, It is obtained by curing the resin composition of claim 7 or 8 after 3D printing, or by making the 3D printed article of claim 9.