Light-cured resin, preparation method and application

Abstract

The invention discloses light-cured resin, a preparation method and application, and belongs to the technical field of light-cured 3D printing. The light-cured resin provided by the invention comprises an acrylate oligomer, a reactive diluent, polyfunctional mercaptan, a polymerization inhibitor, a benzoxazole absorbent and an ultraviolet light absorber, the acrylate oligomer and the reactive diluent are main bodies of the light-cured resin, and the polyfunctional mercaptan and the polymerization inhibitor are added on the basis of the main bodies of the light-cured resin, so that the light-cured resin is prepared. The curing rate can be improved, the reaction speed under low energy is inhibited, the curing degree is improved, the curing thickness is reduced, and the printing precision can be improved. Moreover, by adding the benzoxazole absorbent and the ultraviolet absorbent, the curing thickness can be reduced, and all the components play a synergistic effect, so that the printing precision is improved.

Description

Technical Field

[0001] This application relates to the technical field of photocuring 3D printing, and particularly to a photocuring resin, a preparation method and an application thereof. Background Art

[0002] Photocuring 3D printing is a method of using ultraviolet light to irradiate a photocuring resin to produce 3D products by layer-by-layer curing. For transparent 3D printing materials, since light easily penetrates deep, it often causes the areas without set patterns to be irradiated by ultraviolet light and cured, resulting in overexposure, which will greatly reduce the accuracy of the product. The accuracy of photocuring 3D printing is limited by the layer thickness of each thin slice cut. For some high-precision applications, such as dentistry and fine parts, etc., lower printing layer thicknesses are often required to obtain higher accuracy. And lower layer thickness requires the photocuring resin to have a lower curing layer thickness and a higher curing degree under the set curing energy. Therefore, it is necessary to provide a photocuring resin with a low curing layer thickness and a high curing degree to improve the printing accuracy. Summary of the Invention

[0003] The embodiments of this application provide a photocuring resin, a preparation method and an application thereof. The photocuring resin has both a lower curing layer thickness and a higher curing degree, and can be applied to photocuring 3D printing of transparent materials. The technical solution is as follows:

[0004] On the one hand, a photocuring resin is provided. The photocuring resin comprises the following components in parts by mass:

[0005] 40 - 70 parts of acrylate oligomer, 20 - 50 parts of active diluent, 5 - 20 parts of polyfunctional thiol, 0.5 - 1.5 parts of inhibitor, 1 - 5 parts of photoinitiator, 0 - 0.5 parts of ultraviolet absorber, 0.1 - 2 parts of benzoxazole absorber, 0.001 - 0.01 parts of dye, 0.1 - 0.5 parts of light stabilizer.

[0006] In a possible implementation manner, the acrylate oligomer is selected from at least one of aliphatic polyurethane acrylate and epoxy acrylate.

[0007] In another possible implementation manner, the acrylate oligomer is selected from at least one of Sartomer CN989, CN1964NS, Changxing Chemical EM3261, Runao Chemical FSP8091, Bomar BR-952, Rahn Chemical Genomer*4337.

[0008] In another possible implementation manner, the active diluent is selected from at least one of monofunctional acrylate or methacrylate, difunctional acrylate or methacrylate, acrylamide monomers.

[0009] In another possible implementation, the multifunctional thiol is selected from at least one of trimethylolpropane tris(3-mercaptopropionate), tris[2-(3-mercaptopropoxy)ethyl] isocyanurate, pentaerythritol tetra(3-mercaptopropionate), pentaerythritol tetra(3-mercaptobutyrate), and dipentaerythritol hexa(3-mercaptopropionate).

[0010] In another possible implementation, the benzoxazole absorbent is selected from at least one of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene, 2,2-(4,4-divinylphenyl)bisbenzoxazole, 4,4-bis(5-methyl-2-benzoxazolyl)stilbene, 1,4-bis(benzoxazol-2-yl)naphthalene, and LOT Chemical FV-100.

[0011] In another possible implementation, the photoinitiator is selected from at least one of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-bis(p-tolyl)phosphine oxide, 1-hydroxycyclohexyl phenyl ketone, 2-isopropylthioxanthone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, and 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone.

[0012] In another possible implementation, the ultraviolet absorber is selected from at least one of UV3035, UV1130, and UV400.

[0013] On the other hand, a preparation method of a photocurable resin is provided, and the preparation method includes:

[0014] According to the mass parts of each component, an active diluent and a dye are added to a material tank and ultrasonically dispersed for 20 - 60 min;

[0015] A photoinitiator, a multifunctional thiol, an ultraviolet absorber, a benzoxazole absorbent, a light stabilizer, and a polymerization inhibitor are continuously added and dispersed at a rotation speed of 600 r / min - 800 r / min for 40 - 80 min;

[0016] An acrylate oligomer is continuously added and dispersed at a rotation speed of 800 - 1200 r / min for 40 - 80 min, and after filtration and standing for defoaming, the photocurable resin is obtained.

[0017] On the other hand, an application of the photocurable resin in photocuring a 3D printing transparent material is provided.

[0018] An embodiment of the present application provides a photocurable resin, which includes acrylate oligomer, reactive diluent, polyfunctional mercaptan, inhibitor, benzoxazole absorbent and ultraviolet absorber. Among them, the acrylate oligomer and the reactive diluent are the main components of the photocurable resin. On this basis, adding polyfunctional mercaptan and inhibitor at the same time can inhibit the reaction rate at low energy while increasing the curing rate, reduce the curing thickness while improving the curing degree, and is beneficial to improving the printing accuracy. Moreover, by adding benzoxazole absorbent and ultraviolet absorber, the curing thickness can also be reduced, and each component plays a synergistic role, thereby improving the printing accuracy.

[0019] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a 3D transparent dental appliance provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

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

[0022] On the one hand, an embodiment of the present application provides a photocurable resin, which includes the following components in parts by mass:

[0023] 40-70 parts of acrylate oligomer, 20-50 parts of reactive diluent, 5-20 parts of polyfunctional mercaptan, 0.5-1.5 parts of inhibitor, 1-5 parts of photoinitiator, 0-0.5 parts of ultraviolet absorber, 0.1-2 parts of benzoxazole absorbent, 0.001-0.01 parts of dye, 0.1-0.5 parts of light stabilizer.

[0024] Among them, the mass fraction of the acrylate oligomer can be 40 parts, 42 parts, 45 parts, 50 parts, 52 parts, 55 parts, 60 parts, 62 parts, 65 parts, 70 parts; the mass fraction of the reactive diluent can be 20 parts, 22 parts, 25 parts, 30 parts, 32 parts, 35 parts, 40 parts, 45 parts, 48 parts, 50 parts; the mass fraction of the polyfunctional thiol can be 5 parts, 8 parts, 9 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts; the mass fraction of the inhibitor can be 0.5 part, 0.6 part, 0.7 part, 0.8 part, 1 part, 1.2 parts, 1.4 parts, 1.5 parts; the mass fraction of the photoinitiator can be 1 part, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts; the mass fraction of the ultraviolet absorber can be 0 part, 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, 0.35 part, 0.4 part, 0.45 part, 0.5 part; the mass fraction of the benzoxazole absorber can be 0.1 part, 0.2 part, 0.5 part, 0.8 part, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts; the mass fraction of the dye can be 0.001 part, 0.002 part, 0.003 part, 0.004 part, 0.005 part, 0.006 part, 0.007 part, 0.008 part, 0.009 part, 0.01 part; the mass fraction of the light stabilizer can be 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, 0.35 part, 0.4 part, 0.45 part, 0.5 part.

[0025] An embodiment of the present application provides a photocurable resin, which includes an acrylate oligomer, a reactive diluent, a polyfunctional thiol, an inhibitor, a benzoxazole absorber and an ultraviolet absorber. Among them, the acrylate oligomer and the reactive diluent are the main components of the photocurable resin. On this basis, adding a polyfunctional thiol and an inhibitor at the same time can inhibit the reaction rate at low energy while increasing the curing rate, reduce the curing thickness while improving the curing degree, which is beneficial to improving the printing accuracy. And by adding a benzoxazole absorber and an ultraviolet absorber, the curing thickness can also be reduced, and each component plays a synergistic role, thereby improving the printing accuracy.

[0026] In a possible implementation manner, the acrylate oligomer is selected from at least one of aliphatic polyurethane acrylate and epoxy acrylate.

[0027] In this implementation, the acrylate oligomer can be an aliphatic polyurethane acrylate, can be an epoxy acrylate, or can be a blend of an aliphatic polyurethane acrylate and an epoxy acrylate. If the acrylate oligomer is a blend of an aliphatic polyurethane acrylate and an epoxy acrylate, the blending ratio between the two can be set and changed as needed. For example, the mass fraction ratio of the aliphatic polyurethane acrylate to the epoxy acrylate is 20:40, 20:35, 30:30, 20:25, 20:30, 40:25, 40:20, and no specific limitation is imposed thereon.

[0028] Among them, both the aliphatic polyurethane acrylate and the epoxy acrylate have a functionality of 2 to 3, and the weight average molecular weight ranges of both are 400 g / mol to 2000 g / mol.

[0029] Specifically, the acrylate oligomer can be selected from at least one of Sartomer CN989, CN1964NS, Changxing Chemical EM3261, Runao Chemical FSP8091, Bomar BR-952, and Rahn Chemical Genomer*4337.

[0030] Among them, Sartomer CN989, CN1964NS, FSP8091, Bomar BR-952, and Rahn Chemical Genomer*4337 belong to aliphatic polyurethane acrylates, and Changxing Chemical EM3261 belongs to epoxy acrylates.

[0031] In the embodiments of the present application, the molecular weight of the acrylate oligomer not only affects the curing speed of the photocurable resin but also affects the viscosity of the photocurable resin. The acrylate oligomer with a high molecular weight has a high viscosity, and the acrylate oligomer with a low molecular weight has a low viscosity. Selecting the acrylate oligomer within the above molecular weight range can make the photocurable resin have a suitable curing speed and viscosity. Correspondingly, the functionality of the acrylate oligomer also affects the performance of the photocurable resin. The level of functionality determines the length of the polymer molecular chain and the crosslinking density, thereby affecting the performance of the photocurable resin.

[0032] The present application uses the acrylate oligomer within the above molecular weight range and functionality together with other components, which can not only make the photocurable resin have a suitable viscosity and curing speed but also improve the performance of the photocurable resin.

[0033] In a possible implementation, the reactive diluent is selected from at least one of monofunctional acrylates or methacrylates, difunctional acrylates or methacrylates, and acrylamide monomers.

[0034] Among them, the monofunctional acrylate or methacrylate is selected from at least one of isobornyl acrylate (IBOA), 4-tert-butylcyclohexyl acrylate (TBCHA), 3,3,5-trimethylcyclohexyl acrylate (TMCHA), isobornyl methacrylate (IBOMA), cyclotrimethylolpropane formal acrylate (CTFA), and Rahn Chemical Genomer*1122.

[0035] The difunctional acrylate or methacrylate is selected from at least one of tripropylene glycol diacrylate (TPGDA), tetraethoxylated bisphenol A diacrylate (BPA4EODA), decaethoxylated bisphenol A diacrylate (BPA10EODA), and triethylene glycol dimethacrylate (TEGDMA).

[0036] The acrylamide monomer is selected from at least one of 4-acryloylmorpholine (ACMO), dimethylacrylamide (DMAA), and diethylacrylamide (DEAA).

[0037] In the embodiments of the present application, the above-mentioned reactive diluent is compounded with other components, which can reduce the viscosity of the photocurable resin and improve the fluidity of the photocurable resin.

[0038] In a possible implementation manner, the polyfunctional thiol is selected from at least one of trimethylolpropane tris(3-mercaptopropionate) (TMPMP), tris[2-(3-mercaptopropoxy)ethyl] isocyanurate (TEMPIC), pentaerythritol tetra(3-mercaptopropionate) (PETMP), pentaerythritol tetra(3-mercaptobutyrate) (PE1), and dipentaerythritol hexa(3-mercaptopropionate) (DTMPS).

[0039] Among them, TMPMP and TEMPIC are trifunctional thiols, PETMP and PE1 are tetrafunctional thiols, and DTMPS is a hexafunctional thiol.

[0040] In the embodiments of the present application, the polyfunctional thiol is compounded with an inhibitor and other components, which can inhibit the curing effect at low energy while increasing the overall curing rate, reduce the curing thickness while increasing the degree of curing, and adding the polyfunctional thiol can also improve oxygen inhibition and increase the curing speed of the photocurable resin, and reduce the viscosity of the photocurable resin.

[0041] In a possible implementation manner, the benzoxazole absorbent is selected from at least one of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene (OB), 2,2-(4,4-divinylphenyl)bisbenzoxazole, 4,4-bis(5-methyl-2-benzoxazolyl)stilbene, 1,4-bis(benzoxazol-2-yl)naphthalene, and LOTTE Chemical FV-100.

[0042] In the embodiments of the present application, the benzoxazole absorbent can adjust the curing layer thickness and curing accuracy of the photocurable resin, and while absorbing light energy, it can cooperate with the photoinitiator to generate energy conversion, thereby improving the curing degree of the photocurable resin.

[0043] In a possible implementation, the photoinitiator is selected from at least one of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator TPO), 2,4,6-trimethylbenzoyl-bis(p-tolyl)phosphine oxide (photoinitiator TMO), 1-hydroxycyclohexyl phenyl ketone (photoinitiator 184), 2-isopropylthioxanthone (photoinitiator ITX), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone (photoinitiator 369), 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone (photoinitiator 379), 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (photoinitiator 907).

[0044] Furthermore, one of TPO and TMO can be used in combination with one of photoinitiators 184, ITX, 369, 379, 907 as the photoinitiator.

[0045] In the embodiments of the present application, the photoinitiator is an acylphosphine oxide photoinitiator. This type of photoinitiator has good absorption at a wavelength of 365-405 nm of the light source for photocurable 3D printing and can initiate reaction polymerization. Moreover, it also has a photo-bleaching effect. After participating in the curing, the absorbance decreases, and better light uniformity can be obtained.

[0046] In a possible implementation, the ultraviolet absorber is selected from at least one of UV3035, UV1130, and UV400.

[0047] In the embodiments of the present application, the ultraviolet absorber can adjust the curing layer thickness of the photocurable resin and improve the light aging color stability of the photocurable resin.

[0048] In a possible implementation, the inhibitor is selected from at least one of aluminum N-nitroso-N-phenylhydroxylamine (inhibitor 510), 2,6-di-tert-butyl-p-cresol (BHT), p-methoxyphenol (MEHQ), phenothiazine (PTZ), Rahn Chemical Genorad*16, and Genorad*20.

[0049] In the embodiments of the present application, the inhibitor is used in combination with polyfunctional mercaptan. While improving the overall curing rate, it can inhibit the curing effect at low energy. While improving the curing degree, it reduces the curing thickness. Moreover, the inhibitor can also increase the system stability and reduce the influence of trace light transmitted and scattered on the accuracy.

[0050] In a possible implementation, the dye is selected from blue dyes, such as at least one of cryptocrystalline violet, ultramarine, and blue dyes.

[0051] In the embodiments of the present application, using the above dyes can not only provide the desired color for the photocurable resin, but also effectively reduce the yellowing effect of the photocurable resin.

[0052] In a possible implementation, the light stabilizer is selected from at least one of Tinuvin 292, Tinuvin 770, and light stabilizer 944.

[0053] In the embodiments of the present application, using the above light stabilizer can not only effectively protect the photocurable resin from ultraviolet damage and extend its service life, but also improve the color aging stability of the product.

[0054] On the other hand, the embodiments of the present application provide a method for preparing a photocurable resin, and the preparation method includes:

[0055] Step 1: Add the reactive diluent and the dye to the feed tank according to the mass parts of each component, and ultrasonically disperse for 20 - 60 min.

[0056] Add the reactive diluent and the dye to the feed tank, ultrasonically disperse for 20 - 60 min, and proceed to the next step after dissolution.

[0057] Among them, the dispersion time can be 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min.

[0058] Step 2: Continuously add the photoinitiator, polyfunctional mercaptan, ultraviolet absorber, benzoxazole absorber, light stabilizer, and inhibitor, and disperse at a rotation speed of 600 r / min - 800 r / min for 40 - 80 min.

[0059] Among them, a high-speed disperser can be used to disperse at a rotation speed of 600 r / min - 800 r / min for 40 - 80 min.

[0060] The rotation speed can be 600 r / min, 650 r / min, 680 r / min, 700 r / min, 750 r / min, 780 r / min, 800 r / min. The dispersion time can be 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min.

[0061] Step 3: Continuously add acrylate oligomer and disperse it at a speed of 800 r / min to 1200 r / min for 40 to 80 minutes. After filtration, standing, and defoaming, a photocurable resin is obtained.

[0062] Among them, during filtration, a 300-mesh filter cloth can be used for filtration.

[0063] The rotation speed in this step can be 800 r / min, 850 r / min, 900 r / min, 950 r / min, 1000 r / min, 1050 r / min, 1100 r / min, 1150 r / min, 1200 r / min. The dispersion time can be 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min.

[0064] On the other hand, the present application also provides an application of a photocurable resin in photocuring 3D printing transparent materials.

[0065] The transparent material can be a dental material, a fine part, or a material in other aspects, and no specific limitation is made thereto.

[0066] Printing step: Pour the photocurable resin into the material tank of a photocurable 3D printer, import the pre-printed model into the 3D printer, and set the printing parameters (such as printing layer thickness, single-layer light irradiation time) and then perform printing. For example, the printing layer thickness is 30 μm, and the single-layer light irradiation time is 3 s. After printing is completed, take out the model, remove the support and clean it with a solvent (such as alcohol, isopropyl alcohol, etc.). After cleaning is completed, perform surface treatment such as grinding and polishing, and then put it into a light box for post-curing.

[0067] See Figure 1 , Figure 1 As shown in the 3D transparent dental appliance printed with the photocurable resin provided by the present application, it can be seen that the printed 3D printing dental appliance has a transparent appearance, high precision, and clear details, meeting the appearance requirements of invisible orthodontic dental appliances.

[0068] To make the technical solutions and advantages of the present application clearer, the following will be elaborated in detail through specific examples.

[0069] In the following specific examples, operations not specified in terms of conditions are all carried out according to conventional conditions or conditions recommended by the manufacturer. Raw materials not specified in terms of manufacturer and specifications are all conventional products that can be obtained through commercial purchase.

[0070] Among them, the acrylate oligomer is selected from Rahn Chemical Genomer*4337, Runao Chemical FSP8091, Bomar BR-952, Sartomer CN1964NS, Changxing Chemical EM3261;

[0071] The multifunctional mercaptans are selected from PE1 and PETMP;

[0072] The reactive diluents are selected from ACMO, TBCHA, IBOA, Genomer*1122, and TMCHA;

[0073] The photoinitiators are selected from TPO, TMO, 819, 379, and 184;

[0074] The polymerization inhibitors are selected from polymerization inhibitor 510 and PTZ;

[0075] The benzoxazole absorbers are selected from OB and Lot Chemical FV-100;

[0076] The light stabilizers are selected from Tinuvin 292;

[0077] The ultraviolet absorbers are selected from UV3035 and 1130;

[0078] The dyes are selected from ultramarine.

[0079] Example 1

[0080] Example 1 provides a photocurable resin, which is prepared by the following method: Add 36 parts by mass of TMCHA and 0.002 parts by mass of ultramarine into a material tank, and ultrasonically disperse for 30 min; Then continue to add 3 parts by mass of photoinitiator TPO, 10 parts by mass of PETMP, 0.05 parts by mass of UV3035, 0.8 parts by mass of FV-100, 0.2 parts by mass of Tinuvin 292, and 1 part by mass of PTZ, and disperse for 60 min; Then continue to add 18 parts by mass of Genomer*4337 and 36 parts by mass of BR-952, and disperse for 60 min. After filtration and standing to defoam, the photocurable resin is obtained.

[0081] Example 2

[0082] Example 2 provides a photocurable resin, which is prepared by the following method: Add 36 parts by mass of TMCHA and 0.002 parts by mass of ultramarine into a material tank, and ultrasonically disperse for 30 min; Then continue to add 3 parts by mass of photoinitiator TMO, 10 parts by mass of PETMP, 0.05 parts by mass of UV3035, 0.8 parts by mass of FV-100, 0.2 parts by mass of Tinuvin 292, and 1 part by mass of PTZ, and disperse for 60 min; Then continue to add 18 parts by mass of Genomer*4337 and 36 parts by mass of BR-952, and disperse for 60 min. After filtration and standing to defoam, the photocurable resin is obtained.

[0083] Example 3

[0084] Example 3 provides a photocurable resin, which is prepared by the following method: Add 35 parts by mass of TBCHA and 0.002 parts by mass of ultramarine into a feed tank, and ultrasonically disperse for 30 min; continue to add 2.5 parts by mass of photoinitiator TMO, 15 parts by mass of PE1, 0.5 parts by mass of OB, 0.2 parts by mass of Tinuvin 292, 0.8 parts by mass of PTZ, and disperse for 60 min; continue to add 15 parts by mass of Genomer*4337, 35 parts by mass of FSP8091, disperse for 60 min, filter, stand for defoaming, and obtain the photocurable resin.

[0085] Example 4

[0086] Example 4 provides a photocurable resin, which is prepared by the following method: Add 35 parts by mass of ACMO and 0.002 parts by mass of ultramarine into a feed tank, and ultrasonically disperse for 30 min; continue to add 2.7 parts by mass of photoinitiator TMO, 15 parts by mass of PETMP, 0.1 parts by mass of UV3035, 0.5 parts by mass of OB, 0.2 parts by mass of Tinuvin 292, 1 part by mass of inhibitor 510, and disperse for 60 min; continue to add 17 parts by mass of BR-952, 33 parts by mass of CN1964NS, disperse for 60 min, filter, stand for defoaming, and obtain the photocurable resin.

[0087] Example 5

[0088] Example 5 provides a photocurable resin, which is prepared by the following method: Add 30 parts by mass of ACMO and 0.002 parts by mass of ultramarine into a feed tank, and ultrasonically disperse for 30 min; continue to add 2.5 parts by mass of photoinitiator TMO, 8 parts by mass of PETMP, 0.15 parts by mass of UV3035, 0.7 parts by mass of OB, 0.2 parts by mass of Tinuvin 292, 0.8 parts by mass of PTZ, and disperse for 60 min; continue to add 40 parts by mass of FSP8091, 25 parts by mass of EM3261, disperse for 60 min, filter, stand for defoaming, and obtain the photocurable resin.

[0089] Example 6

[0090] Example 6 provides a photocurable resin, which is prepared by the following method: Add 25 parts by mass of IBOA, 10 parts by mass of Genomer*1122, and 0.001 part by mass of ultramarine into a feed tank, and ultrasonically disperse for 30 min; then continue to add 2.6 parts by mass of TPO, 0.5 part by mass of photoinitiator 184, 8 parts by mass of PETMP, 0.1 part by mass of UV3035, 0.4 part by mass of FV-100, 0.1 part by mass of Tinuvin 292, and 0.6 part by mass of inhibitor 510, and disperse for 60 min; then continue to add 30 parts by mass of Genomer*4337 and 30 parts by mass of BR-952, disperse for 60 min, filter, and let stand to defoam to obtain the photocurable resin.

[0091] Example 7

[0092] Example 7 provides a photocurable resin, which is prepared by the following method: Add 10 parts by mass of ACMO, 30 parts by mass of IBOA, and 0.002 part by mass of ultramarine into a feed tank, and ultrasonically disperse for 30 min; then continue to add 2.5 parts by mass of TMO, 0.5 part by mass of photoinitiator 379, 9 parts by mass of PETMP, 0.1 part by mass of UV3035, 0.5 part by mass of OB, 0.2 part by mass of Tinuvin 292, and 0.5 part by mass of inhibitor 510, and disperse for 60 min; then continue to add 20 parts by mass of Genomer*4337 and 25 parts by mass of BR-952, disperse for 60 min, filter, and let stand to defoam to obtain the photocurable resin.

[0093] Example 8

[0094] Example 8 provides a photocurable resin, which is prepared by the following method: Add 20 parts by mass of IBOA, 20 parts by mass of TMCHA, and 0.001 part by mass of ultramarine into a feed tank, and ultrasonically disperse for 30 min; then continue to add 2.6 parts by mass of photoinitiator TMO, 0.6 part by mass of photoinitiator 184, 5 parts by mass of PETMP, 0.1 part by mass of UV3035, 0.4 part by mass of FV-100, 0.1 part by mass of Tinuvin292, and 0.5 part by mass of PTZ, and disperse for 60 min; then continue to add 20 parts by mass of Genomer*4337 and 30 parts by mass of CN1964NS, disperse for 60 min, filter, and let stand to defoam to obtain the photocurable resin.

[0095] Comparative Example 1

[0096] Comparative Example 1 provided a photocurable resin, which was prepared by the following method: Add 36 parts by mass of TMCHA and 0.002 parts by mass of ultramarine in a feed tank, and ultrasonically disperse for 30 min; then continue to add 3 parts by mass of photoinitiator 819, 10 parts by mass of PETMP, 0.05 parts by mass of UV3035, 0.8 parts by mass of FV-100, 0.2 parts by mass of Tinuvin 292, and 1 part by mass of PTZ, and disperse for 60 min; then continue to add 18 parts by mass of Genomer*4337 and 36 parts by mass of BR-952, disperse for 60 min, filter, and stand for defoaming to obtain the photocurable resin.

[0097] Comparative Example 2

[0098] Comparative Example 2 provided a photocurable resin, which was prepared by the following method: Add 36 parts by mass of TMCHA and 0.002 parts by mass of ultramarine in a feed tank, and ultrasonically disperse for 30 min; then continue to add 2 parts by mass of photoinitiator 819, 10 parts by mass of PETMP, 0.05 parts by mass of UV3035, 0.8 parts by mass of FV-100, 0.2 parts by mass of Tinuvin 292, and 1 part by mass of PTZ, and disperse for 60 min; then continue to add 18 parts by mass of Genomer*4337 and 36 parts by mass of BR-952, disperse for 60 min, filter, and stand for defoaming to obtain the photocurable resin.

[0099] Comparative Example 3

[0100] Comparative Example 3 provided a photocurable resin, which was prepared by the following method: Add 40 parts by mass of ACMO in a feed tank, and ultrasonically disperse for 30 min; then continue to add 3 parts by mass of TMO, and disperse for 60 min; then continue to add 20 parts by mass of Genomer*4337 and 40 parts by mass of BR-952, disperse for 60 min, filter, and stand for defoaming to obtain the photocurable resin.

[0101] Comparative Example 4

[0102] Comparative Example 4 provided a photocurable resin, which was prepared by the following method: Add 40 parts by mass of ACMO and 0.002 parts by mass of ultramarine in a feed tank, and ultrasonically disperse for 30 min; then continue to add 3 parts by mass of TMO and 0.2 parts by mass of Tinuvin 292, and disperse for 60 min; then continue to add 20 parts by mass of Genomer*4337 and 40 parts by mass of BR-952, disperse for 60 min, filter, and stand for defoaming to obtain the photocurable resin.

[0103] Comparative Example 5

[0104] Comparative Example 5 provides a photocurable resin, which is prepared by the following method: Add 40 parts by mass of ACMO and 0.002 parts by mass of ultramarine blue into a feed tank, and ultrasonically disperse for 30 min; then continue to add 6 parts by mass of TMO, 0.2 parts by mass of Tinuvin 292, and disperse for 60 min; then continue to add 20 parts by mass of Genomer*4337, 40 parts by mass of BR-952, and disperse for 60 min. After filtration and static defoaming, the photocurable resin is obtained.

[0105] Comparative Example 6

[0106] Comparative Example 6 provides a photocurable resin, which is prepared by the following method: Add 40 parts by mass of ACMO and 0.002 parts by mass of ultramarine blue into a feed tank, and ultrasonically disperse for 30 min; then continue to add 3 parts by mass of TMO, 10 parts by mass of PETMP, and 0.2 parts by mass of Tinuvin 292, and disperse for 60 min; then continue to add 20 parts by mass of Genomer*4337, 40 parts by mass of BR-952, and disperse for 60 min. After filtration and static defoaming, the photocurable resin is obtained.

[0107] Comparative Example 7

[0108] Comparative Example 7 provides a photocurable resin, which is prepared by the following method: Add 40 parts by mass of ACMO and 0.002 parts by mass of ultramarine blue into a feed tank, and ultrasonically disperse for 30 min; then continue to add 3 parts by mass of TMO, 0.2 parts by mass of Tinuvin 292, 1 part by mass of PTZ, and disperse for 60 min; then continue to add 20 parts by mass of Genomer*4337, 40 parts by mass of BR-952, and disperse for 60 min. After filtration and static defoaming, the photocurable resin is obtained.

[0109] Comparative Example 8

[0110] Comparative Example 8 provides a photocurable resin, which is prepared by the following method: Add 40 parts by mass of ACMO and 0.002 parts by mass of ultramarine blue into a feed tank, and ultrasonically disperse for 30 min; then continue to add 3 parts by mass of TMO, 0.2 parts by mass of Tinuvin 292, and 1 part by mass of UV1130, and disperse for 60 min; then continue to add 20 parts by mass of Genomer*4337, 40 parts by mass of BR-952, and disperse for 60 min. After filtration and static defoaming, the photocurable resin is obtained.

[0111] Comparative Example 9

[0112] Comparative Example 9 provided a photocurable resin, which was prepared by the following method: 40 parts by mass of ACMO and 0.002 parts by mass of ultramarine were added to a feed tank and ultrasonically dispersed for 30 min; 3 parts by mass of TMO, 1 part by mass of FV-100 and 0.2 parts by mass of Tinuvin 292 were continuously added and dispersed for 60 min; 20 parts by mass of Genomer*4337 and 40 parts by mass of BR-952 were continuously added and dispersed for 60 min. After filtration and standing for defoaming, the photocurable resin was obtained.

[0113] The formulations of Examples 1 to 8 above can be seen in Table 1 below, and the formulations of Comparative Examples 1 to 9 can be seen in Table 2 below.

[0114] Table 1

[0115]

[0116]

[0117] Table 2

[0118]

[0119]

[0120] Application Example

[0121] A DLP type 3D printer with a wavelength of 405 nm and a printer light intensity of 2 - 5 mW·cm -1 was selected for the printing test, and the set printing thickness per layer was 30 μm and the single-layer light irradiation time was 3 s.

[0122] The appearance color was determined visually.

[0123] Test method for the degree of curing: The prepared photocurable resin was coated on a quartz slide with a coating thickness of 30 μm, and the surface layer was covered with a release film. Then the quartz slide was placed on the light irradiation platform of the printer and set to irradiate and cure for 3 s. The slide was taken out, the release film was removed, and the cured resin film was taken off. The infrared spectra of the side with the release film attached and the infrared spectrum of the photocurable resin liquid before curing were respectively scanned using a Fourier red spectrometer, and then the spectra were processed to obtain the degree of curing.

[0124] Infrared spectrum processing method: Integrate the reaction characteristic absorption peak at 1410 cm -1 , and then integrate the standard absorption peak (such as: the carbonyl absorption peak at 1730 cm -1 ). The area integral ratio of the two absorption peaks was defined as:

[0125] AU liquid = A liquid (1410 cm -1 ) / A liquid (1730 cm-1 )

[0126] AU sample = A sample (1410 cm -1 ) / A sample (1730 cm -1 )

[0127] Degree of curing = ((AU liquid - AU sample) / AU liquid) * 100%.

[0128] The test method for the curable thickness is as follows: Coating the prepared photocurable resin on a quartz slide with a coating thickness of about 1 mm, then placing the quartz slide on the light exposure platform of the printer and setting the light exposure curing time to 3 s. Taking out the slide, wiping off the uncured liquid part, and then measuring the film thickness of the cured part, which is the curable thickness.

[0129] Test method for the ratio of actual size to set size:

[0130] Importing the drawn printing model into a 3D printer, setting the exposure time for each layer to 3 s and printing under the condition of a layer thickness of 30 μm. After printing and cleaning, removing the column and using a vernier caliper to measure the actual width of the column, and then calculating the value of actual size / set size.

[0131] Model drawing: Using 3D drawing software to draw 64 columns with a bottom surface of a quadrilateral of 2 mm × 2 mm and a height of 1 cm, arranged in a grid pattern evenly on a plane with a spacing of 1 mm between the columns, and exporting the model in 3D printing format.

[0132] Using the above test methods to perform 3D printing on the photocurable resins prepared in Examples 1 - 8 and Comparative Examples 1 - 9. Among them, the test results of Examples 1 - 8 can be seen in Table 3 below, and the test results of Comparative Examples 1 - 9 can be seen in Table 4 below.

[0133] Table 3

[0134]

[0135] Table 4

[0136]

[0137] Comparing Example 1, Example 2 and Comparative Example 1, the only difference is the type of photoinitiator. It can be found that in the system, the initiation efficiency of TMO and TPO is comparable. The degree of curing of the sample using TMO is comparable to that of the sample using TPO, and the curing depth of the sample using TMO is slightly lower than that of the sample using TPO. 819 Due to the too strong initiation efficiency, serious light attenuation occurs, and at the same addition amount, the degree of curing and the curable thickness of the sample both show a significant decrease, and printing cannot be formed.

[0138] The difference between Comparative Example 2 and Comparative Example 1 lies in reducing the addition amount of 819. It can be seen that after reducing the addition amount of 819 in Comparative Example 2, the curing degree, curing thickness and printing accuracy of the sample are comparable to those of Example 2, that is, the sample when using TMO, but the appearance is light yellow. And TPO has reproductive toxicity problems and is listed in the Candidate List of Substances of Very High Concern, which limits its application. Therefore, the photoinitiator TMO is selected.

[0139] Comparative Example 3 is a pure resin composition without special additives, which is close to the commercially available 3D printing formulation. It can be seen that for the pure resin composition without special additives, the ability to absorb light from the light source is weak, and the light easily penetrates deep into it, resulting in a higher curing thickness and a lower curing degree. When printing, there is a problem that the areas not set are also cured, resulting in a serious decline in printing accuracy, and it is not suitable for 3D printing with a low layer thickness.

[0140] Compared with Comparative Example 3, only dyes and light stabilizers are added in Comparative Example 4. It can be seen that after adding dyes and light stabilizers, yellowing is better inhibited, and the color after curing changes from light yellow to colorless and transparent, and the curing effect is not significantly affected.

[0141] In Comparative Example 5, the amount of photoinitiator is increased on the basis of Comparative Example 4. Increasing the amount of photoinitiator can increase the absorption of ultraviolet light, thereby reducing the curing thickness, but it correspondingly brings the problem of yellowing. At the same time, too much amount of photoinitiator will also bring adverse effects such as small molecule migration and reduction of mechanical properties.

[0142] In Comparative Example 6, polyfunctional thiols are added on the basis of Comparative Example 4. The addition of polyfunctional thiols increases the curing degree at 30 μm. Due to the excellent reactivity of the mercapto group, it increases the curing activity of the system and improves the curing degree. However, at the same time, the curing thickness is increased. Therefore, adding polyfunctional thiols alone is not conducive to improving the printing accuracy.

[0143] In Comparative Example 7, inhibitors are added on the basis of Comparative Example 4. Some conventional photocuring resin formulations also add inhibitors, but only to increase the storage stability of the formulation, and the addition amount is about 0.01 - 0.5%. At this content, the curing effect is basically not affected. In this application, the amount of inhibitor is increased, and by increasing the amount of inhibitor, it plays the role of reducing the curing thickness, but the corresponding curing degree is also affected. Therefore, adding inhibitors alone is not conducive to improving the printing accuracy.

[0144] In Examples 1 - 8, polyfunctional thiols and inhibitors are added simultaneously, which improves the overall curing rate while inhibiting the curing effect at low energy. While improving the curing degree, it reduces the curing thickness, thereby improving the printing accuracy.

[0145] Comparative Example 8 added an ultraviolet absorber on the basis of Comparative Example 4. Adding the ultraviolet absorber can reduce the curing thickness. However, the ultraviolet absorber only absorbs light energy and does not generate energy conversion with the photoinitiator and resin to promote curing. While reducing the curing thickness, the curing degree also decreases accordingly. However, adding the ultraviolet absorber can effectively reduce the risk of yellowing of the cured sample caused by ultraviolet irradiation aging.

[0146] Comparative Example 9 added a benzoxazole absorber on the basis of Comparative Example 4. Adding the benzoxazole absorber can significantly reduce the curing thickness and adjust the printing accuracy, but there is still a problem of low curing degree.

[0147] In Examples 1 to 8, while increasing the reaction rate and the curing degree by adding polyfunctional thiols, the reaction rate at low energy was inhibited by adding a polymerization inhibitor, the curing degree was increased by adding a benzoxazole absorber, and at the same time, the curing thickness was reduced. Then, a small amount of ultraviolet absorber, dye and light stabilizer were added to adjust the curing thickness, so as to achieve the effect of good printing accuracy.

[0148] In summary, the present application achieves the effect of improving the printing accuracy by comprehensively and synergistically matching the type and addition amount of the photoinitiator, polyfunctional thiols, polymerization inhibitor, benzoxazole absorber, ultraviolet absorber and light stabilizer. That is, the technical effect produced by the present application is achieved by the synergistic effect of each component, and simply adding a single component among them has no obvious improvement effect on the improvement of the printing accuracy.

[0149] The above description is only for the convenience of those skilled in the art to understand the technical solution of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A photocurable resin, characterized in that, The photocurable resin comprises the following components in parts by mass: 40 - 70 parts of acrylate oligomer, 20 - 50 parts of reactive diluent, 5 - 20 parts of polyfunctional thiol, 0.5 - 1.5 parts of inhibitor, 1 - 5 parts of photoinitiator, 0 - 0.5 parts of ultraviolet absorber, 0.1 - 2 parts of benzoxazole absorber, 0.001 - 0.01 parts of dye, 0.1 - 0.5 parts of light stabilizer.

2. The photocurable resin according to claim 1, wherein The acrylate oligomer is selected from at least one of aliphatic polyurethane acrylate and epoxy acrylate.

3. The photocurable resin according to claim 2, wherein The acrylate oligomer is selected from at least one of Sartomer CN989, CN1964NS, Changxing Chemical EM3261, Runao Chemical FSP8091, Bomar BR - 952, Rahn Chemical Genomer*4337.

4. The photocurable resin according to claim 1, wherein The reactive diluent is selected from at least one of monofunctional acrylate or methacrylate, difunctional acrylate or methacrylate, acrylamide monomers.

5. The photocurable resin according to claim 1, wherein The polyfunctional thiol is selected from at least one of trimethylolpropane tris(3 - mercaptopropionate), tris[2 - (3 - mercaptopropoxy)ethyl] isocyanurate, pentaerythritol tetra(3 - mercaptopropionate), pentaerythritol tetra(3 - mercaptobutyrate), dipentaerythritol hexa(3 - mercaptopropionate).

6. The photocurable resin according to claim 1, wherein The benzoxazole absorber is selected from at least one of 2,5 - bis(5 - tert - butyl - 2 - benzoxazolyl)thiophene, 2,2 - (4,4 - divinylstyryl)bisbenzoxazole, 4,4 - bis(5 - methyl - 2 - benzoxazolyl)stilbene, 1,4 - bis(benzoxazol - 2 - yl)naphthalene, Lot Chemical FV - 100.

7. The photocurable resin according to claim 1, characterized in that, The photoinitiator is selected from at least one of diphenyl(2,4,6 - trimethylbenzoyl)phosphine oxide, 2,4,6 - trimethylbenzoyl - bis(p - tolyl)phosphine oxide, 1 - hydroxycyclohexyl phenyl ketone, 2 - isopropylthioxanthone, 2 - benzyl - 2 - dimethylamino - 1 - (4 - morpholinophenyl)butanone, 2 - (4 - methylbenzyl)-2 - (dimethylamino)-1 - (4 - morpholinophenyl)-1 - butanone, 2 - methyl - 1 - [4 - (methylthio)phenyl]-2 - (4 - morpholino)-1 - propanone.

8. The photocurable resin according to claim 1, characterized in that, The ultraviolet absorber is selected from at least one of UV3035, UV1130, UV400.

9. A method for preparing the photocurable resin according to any one of claims 1 to 8, characterized in that, The preparation method comprises: Adding the reactive diluent and the dye into a storage tank according to the parts by mass of each component, and performing ultrasonic dispersion for 20 - 60 min; Continuously adding the photoinitiator, polyfunctional thiol, ultraviolet absorber, benzoxazole absorber, light stabilizer and inhibitor, and dispersing at a rotation speed of 600 r / min - 800 r / min for 40 - 80 min; Continuously adding the acrylate oligomer, and dispersing at a rotation speed of 800 - 1200 r / min for 40 - 80 min. After filtering and standing for defoaming, the photocurable resin is obtained.

10. Application of the photocurable resin according to any one of claims 1 - 8 in photocuring 3D printing transparent materials.

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