Photocurable composition and use thereof in 3D printing, and 3D printed product

Abstract

The present invention relates to a photocurable composition and a use thereof in 3D printing, particularly in SLA 3D printing, and a 3D printed product obtainable from the photocurable composition. The photocurable composition of the present invention has good curing performance, and can be used for preparing large-sized products having complex and fine structures, and the obtained printed products have good mechanical properties and good appearance.

Description

Photocurable compositions and their uses in 3D printing and 3D printed products Technical Field

[0001] This invention relates to a photocurable composition and its use in 3D printing, particularly SLA 3D printing, and 3D printed products that can be obtained from said photocurable composition. Background Technology

[0002] 3D printing technology, also known as additive manufacturing, originated in the 1980s and has now developed into an extremely important material manufacturing method. Compared with traditional processing methods, 3D printing does not require molds, avoiding machining and subtractive manufacturing methods. Furthermore, 3D printing is computer-controlled, giving it exceptional precision and the ability to manufacture complex and precise structures. In recent years, photopolymer-based 3D printing technology has received considerable attention due to its "green" characteristics, such as energy saving, environmental friendliness, and high efficiency. Consequently, research on photopolymer 3D printing has been extensively reported. These methods typically offer advantages such as mild processing conditions, near 100% material utilization, and high production efficiency, enabling their widespread application.

[0003] Commercially available photoinitiators, such as acylphosphine oxides or thioxanthones, are photosensitized to short-wavelength light, such as near-ultraviolet and blue light, and therefore short-wavelength light is often used as the main light source for photopolymerization 3D printing. However, in recent years, the use of long-wavelength light as a light source has become an important research direction in the field of photopolymerization, since short-wavelength light is detrimental to human health, and its limited penetration ability is not conducive to deep curing. Based on this, photopolymerization technology using near-infrared light (NIR, wavelength greater than 700nm) as a light source has emerged, because near-infrared light is safer for the human body than ultraviolet light, which is extremely important for health issues in actual production processes.

[0004] Several articles have been reported on near-infrared photopolymerization 3D printing. For example, ink-direct writing (DIW) 3D printing based on upconversion nanoparticles (UCNPs) (Nat Commun 2020, 11, 3462) can even manufacture ceramic products under NIR light irradiation (Nat Commun 2023, 14, 2381). However, the preparation process of UCNPs is complex and costly, which reduces its practical application.

[0005] Stereopolymerization (SLA) 3D printing technology boasts advantages such as high processing speed and high precision. Furthermore, compared to DIW and DLP methods, SLA 3D printing offers superior performance in fabricating large-size and intricately complex products. However, current photopolymerizable compositions lack sufficient printability for 3D printing, particularly SLA 3D printing, resulting in poor-quality products even when printing is possible. Therefore, developing a photopolymerizable composition suitable for 3D printing, especially SLA 3D printing, is of great significance. Summary of the Invention

[0006] In view of the problems existing in the prior art, the inventors have conducted in-depth research on photocurable compositions suitable for near-infrared light sources. The inventors have surprisingly discovered that the photocurable composition of this invention is suitable for 3D printing, especially SLA 3D printing, exhibits excellent photocuring performance, and the resulting printed products have good and stable mechanical properties. The photocurable composition of this invention can also contain colorants and can be used to prepare colored products. Furthermore, the photocurable composition of this invention can prepare larger products with complex and intricate structures (such as hollow structures), which is difficult to achieve with existing near-infrared photocurable compositions.

[0007] One object of the present invention is to provide a photocurable composition.

[0008] Another object of the present invention is to provide the use of photocurable compositions in 3D printing, particularly SLA 3D printing.

[0009] Another object of the present invention is to provide a photocurable article obtained from the photocurable composition of the present invention.

[0010] The technical solution for achieving the objective of this invention can be summarized as follows:

[0011] 1. A photocurable composition comprising the following components:

[0012] (a) at least one polymethyl benzoin compound, which serves as an infrared-absorbing photosensitizer;

[0013] (b) at least one photopolymerization initiator;

[0014] (c) at least one free radical photopolymerizable compound;

[0015] (d) at least one electron-donating reducing agent; and

[0016] (e) At least one arylphosphine compound.

[0017] 2. The photocurable composition according to embodiment 1, wherein the polymethyl benzoin compound as component (a) has the structure shown in formula (I):

[0018] in

[0019] Y + This refers to a heterocycle with 8-18 ring members, including one or two nitrogen atoms as ring members, and carrying a positive charge.

[0020] Y represents a heterocycle with 8-18 ring members and containing 1 or 2 nitrogen atoms as ring members, consisting of bicyclic, tricyclic, or more rings.

[0021] Y + The heterocycles defined in Y may have one or more selected from halogens, CN, nitro, C1-C. 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups, C1-C 12 Branched or unbranched alkylthio or phenylthio substituents, wherein the C1-C 12 Branched or unbranched alkyl groups, the C1-C 12 Branched or unbranched alkoxy groups, the C1-C 12 The alkyl group in a branched or unbranched alkylthio group can be separated by one or more non-adjacent oxygen atoms;

[0022] Preferred Y + / Y represents the structural units shown below:

[0023] Indole salt / indole

[0024] Phenyl[e]indole salt / phenyl[e]indole

[0025] And / or phenyl[c,d]indole salt / phenyl[c,d]indole,

[0026] The indole salt / indole, phenyl[e]indole salt / phenyl[e]indole, and phenyl[c,d]indole salt / phenyl[c,d]indole may have one or more naphthalene rings on their benzene or naphthalene rings, preferably one or two selected from halogens, CN, nitro, C1-C. 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups, C1-C 12 Branched or unbranched alkylthio or phenylthio substituents, wherein the C1-C 12 Branched or unbranched alkyl groups, the C1-C 12 Branched or unbranched alkoxy groups, the C1-C 12 The alkyl group in the branched or unbranched alkylthio group may be separated by one or more non-adjacent oxygen atoms; wherein R1 is selected from C1-C1.12 Branched or unbranched alkyl groups and C1-C 12 Branched or unbranched alkoxy groups, wherein the C1-C 12 Branched or unbranched alkyl groups and C1-C 12 Branched or unbranched alkoxy groups can be separated by one or more non-adjacent oxygen atoms, such as –[-CH2CHR-O-]. n The polyether shown is n, which is 1-6, and R is H or CH3;

[0027] The positions of the cyclic carbon indicated by the arrows are the connection sites with the polymethyl tannin chain;

[0028] More preferred Y + / Y represents the structural units shown below:

[0029] and / or

[0030] R1 is selected from C1-C 12 Branched or unbranched alkyl groups and C1-C 12 Branched or unbranched alkoxy groups, wherein the C1-C 12 Branched or unbranched alkyl groups and C1-C 12 Branched or unbranched alkoxy groups can be separated by one or more non-adjacent oxygen atoms, such as –[-CH2CHR-O-]. n The polyethers shown are 1-6, and R is H or CH3; and

[0031] R2 and R3 are independently selected from H, halogen, CN, nitro, C1-C. 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups, C1-C 12 Branched or unbranched alkylthio or phenylthio, wherein the C1-C 12 Branched or unbranched alkyl groups, the C1-C 12 Branched or unbranched alkoxy groups, the C1-C 12 The alkyl group in a branched or unbranched alkylthio group can be separated by one or more non-adjacent oxygen atoms;

[0032] The positions of the cyclic carbon indicated by the arrows are the connection sites with the polymethyl tannin chain;

[0033] n1 and n2 are independently 0, 1 or 2; preferably 0 or 1, more preferably 1;

[0034] B and C are independently selected from H, C1-C 12 Alkyl groups, or together with the carbon atoms that connect them, form five-membered or six-membered rings;

[0035] A is selected from the structures shown in A-1 to A-13:

[0036] Or C1-C 12 Branched or unbranched alkoxy groups (A-13);

[0037] in

[0038] * indicates the connection point with the structure of equation (I).

[0039] Wherein, the "R2 and R2" groups may be the same or different, and each is independently selected from hydrogen, halogen, C1-C6 branched or unbranched alkyl, C1-C6 branched or unbranched alkoxy, C1-C6 branched or unbranched alkylthio or phenylthio.

[0040] Preferably, group A is selected from the structures shown in A-1, A-2, A-4, A-5 or A-7 to A-13;

[0041] When group A is group A-1 or A-2, n3 is 0; when group A is one of groups A-3 to A-13, n3 is 1.

[0042] and X - Indicates counterions.

[0043] 3. The photocurable composition according to embodiment 2, wherein the compound of formula (I) satisfies one or more of the following conditions:

[0044] R1 is selected from C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy, wherein the C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy may be separated by one or two non-adjacent oxygen atoms.

[0045] R2 is selected from H, halogen, nitro, C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy, wherein the C1-C6 branched or unbranched alkyl and the C1-C6 branched or unbranched alkoxy may be separated by one or two non-adjacent oxygen atoms.

[0046] R3 is selected from H, C1-C6 branched or unbranched alkyl groups and C1-C6 branched or unbranched alkoxy groups, wherein the C1-C6 branched or unbranched alkyl groups and the C1-C6 branched or unbranched alkoxy groups may be separated by one or two non-adjacent oxygen atoms.

[0047] 4. The photocurable composition according to embodiment 2 or 3, wherein B and C are independently H or form a five-membered or six-membered ring together with the carbon atoms that connect them, preferably B and C form a five-membered or six-membered ring together with the carbon atoms that connect them.

[0048] 5. A photocurable composition according to any one of items 2-4, wherein the "R2 and R2" groups are the same or different, and each is independently selected from hydrogen or C1-C6 branched or unbranched alkyl groups.

[0049] 6. A photocurable composition according to any one of embodiments 2-5, wherein X - The following counter ion is represented: BF4 - [B(Ph4)] - PF6 - SbF6 - AsF6 - [PF3(C2F5)3] - [Al(OC(CF3)3)4] - [B(PhF5)4] - [B(Ph(CF3)2)4] - [((CF3)2SO2)2N] - [(CF3)2SO2)3C] - Cl - ,Br - F - [Al(Ot-C4F9)4] - [Al(O-(i-C3F7)CH3)4] - [C(O-SO2CF3)3] - [nC] 12 H 25- TsO] - Or [NTf2] - BF4 is preferred. - [B(Ph4)] - PF6 - SbF6 - AsF6 - [PF3(C2F5)3] - [Al(OC(CF3)3)4] - [B(PhF5)4] - [B(Ph(CF3)2)4] - [((CF3)2SO2)2N] - [(CF3)2SO2)3C] - [Al(Ot-C4F9)4] - [Al(O-(i-C3F7)CH3)4] - Or [NTf2] - .

[0050] 7. A photocurable composition according to any one of embodiments 2-6, wherein the polymethyl benzoin compound as component (a) is selected from one or more of compounds S1-S189 as defined herein;

[0051] Preferably, the polymethyl benzoic acid compound used as component (a) is selected from S132, S44 or a mixture thereof.

[0052] 8. The photocurable composition according to any one of embodiments 1-7, wherein the photopolymerization initiator as component (b) is a photopolymerization initiator capable of generating free radicals in the presence of component (a).

[0053] 9. A photocurable composition according to any one of embodiments 1-8, wherein the photopolymerization initiator as component (b) is selected from iodonium salts, thiodonium salts, triazines, and oxime ester photopolymerization initiators.

[0054] 10. A photocurable composition according to any one of embodiments 1-9, wherein the photopolymerization initiator as component (b) is an iodonium salt, preferably selected from iodonium salts as shown in Formula II:

[0055] Among them, R1'-R6' can be the same or different and are independently selected from H, halogen, nitro, C1-C 20 Branched or unbranched alkyl groups, C1-C 20 Branched or unbranched alkoxy groups and C1-C 20 Branched or unbranched alkylthio groups, and X' - As in implementation scheme 2 or 6, X in compound (I) - Defined

[0056] X in the preferred compound (I) - X' in compound (II) - They are the same.

[0057] 11. A photocurable composition according to any one of embodiments 1-10, wherein the photopolymerization initiator as component (b) is selected from one or more compounds IS1-IS41 as defined herein;

[0058] Preferably, the photopolymerization initiator used as component (b) is selected from IS1, IS41 or a mixture thereof.

[0059] 12. The photocurable composition according to any one of embodiments 1-11, wherein the weight ratio of the infrared absorbing photosensitizer as component (a) to the photopolymerization initiator as component (b) is 100:1-1:100, preferably 1:1-1:100, more preferably 1:10-1:100.

[0060] 13. A photocurable composition according to any one of embodiments 1-12, wherein the amount of the infrared absorbing photosensitizer as component (a) is 0.001-5% by weight, preferably 0.01-1% by weight, based on the total weight of the photocurable composition.

[0061] 14. A photocurable composition according to any one of embodiments 1-13, wherein the amount of photopolymerization initiator as component (b) is 0.01-10% by weight, preferably 0.1-5% by weight, based on the total weight of the photocurable composition.

[0062] 15. A photocurable composition according to any one of embodiments 1-14, wherein the free radical photopolymerizable compound comprises at least one of a free radical polymerizable resin, a free radical polymerizable monomer with two or more functional groups, and a free radical polymerizable monomer with a single functional group; preferably, the free radical photopolymerizable compound comprises a free radical polymerizable resin and a free radical polymerizable monomer with two or more functional groups, or the free radical photopolymerizable compound comprises a free radical polymerizable resin and a free radical polymerizable monomer with a single functional group, or the free radical photopolymerizable compound comprises a free radical polymerizable resin, a free radical polymerizable monomer with two or more functional groups, and a free radical polymerizable monomer with a single functional group.

[0063] 16. The photocurable composition according to any one of embodiments 1-15, wherein the electron-donating reducing agent is selected from phenylglycine compounds and aryl borates, preferably selected from phenylglycine compounds and aryl borates, for example selected from sodium tetraphenylborate and N-phenylglycine.

[0064] 17. A photocurable composition according to any one of embodiments 1-16, wherein the weight ratio of the electron-donating reducing agent to the photopolymerization initiator is 5:1-1:50, preferably 1:1-1:40, more preferably 1:2-1:20.

[0065] 18. A photocurable composition according to any one of embodiments 1-17, wherein the amount of said electron-donating reducing agent is 0.05-2% by weight, preferably 0.08-1.2% by weight, based on the total weight of said photocurable composition.

[0066] 19. A photocurable composition according to any one of embodiments 1-18, wherein the arylphosphine compound is an arylphosphine compound having trivalent phosphorus atoms, especially triphenylphosphine.

[0067] 20. A photocurable composition according to any one of embodiments 1-19, wherein the weight ratio of the arylphosphide compound to the photopolymerization initiator is 5:1-1:50, preferably 1:1-1:40, more preferably 1:2-1:20.

[0068] 21. The photocurable composition according to any one of embodiments 1-20, wherein the weight ratio of the electron-donating reducing agent to the arylphosphide compound is 10:1-1:10, preferably 5:1-1:5, more preferably 3:1-1:3.

[0069] 22. A photocurable composition according to any one of embodiments 1-21, wherein the amount of said arylphosphide compound is 0.05-2% by weight, preferably 0.08-1.2% by weight, based on the total weight of said photocurable composition.

[0070] 23. A photocurable composition according to any one of embodiments 1-22, wherein the photocurable composition comprises at least one colorant, such as a dye and pigment, and in particular, the amount of the colorant is 0.05-20% by weight, preferably 0.08-10% by weight or 0.1-2% by weight, based on the total weight of the photocurable composition.

[0071] 24. In the use of the photocurable composition of any of embodiments 1-23 in 3D printing, especially SLA 3D printing, it is preferred to process the photocurable composition using an NIR (laser) light source with an emission wavelength of 700-2000 nm, preferably 750-900 nm.

[0072] 25. A photocurable article obtained from a photocurable composition as described in any one of embodiments 1-23.

[0073] The photocurable composition of the present invention exhibits excellent absorption performance in the near-infrared region and can be cured under low light intensity irradiation. The initiation system used in this photocurable composition can undergo photolysis under near-infrared light irradiation. This photocurable composition has good curing performance, such as a fast polymerization rate and high curing rate. It also has good curing performance even with the addition of colorants. The photocurable composition of the present invention also has good thermal stability. Using the photocurable composition of the present invention, SLA 3D printing can be successfully achieved, and large-sized products with complex and fine structures (such as hollow structures) can be prepared. The resulting printed products have good and stable mechanical properties and good appearance. Attached image description:

[0074] Figure 1 shows the light absorption curve of the photocurable composition of Example 1;

[0075] Figure 2 shows the light absorption curve of the photocurable composition of Example 2;

[0076] Figures 3 and 4 are the polymerization curing rate curves and polymerization rate curves of the photocurable composition of Example 3 under irradiation with an 808nm NIR laser light source.

[0077] Figures 5 and 6 are the polymerization curing rate curves and polymerization rate curves of the photocurable composition of Example 4 under irradiation with an 808nm NIR laser light source.

[0078] Figures 7 and 8 are the polymerization curing rate curves and polymerization rate curves of the photocurable composition of Example 5 under irradiation with an 808nm NIR laser light source.

[0079] Figures 9 and 10 show the polymerization curing rate curve and polymerization rate curve of the photocurable composition of Example 6 under irradiation with an 808nm NIR laser light source;

[0080] Figure 11 is a curve of temperature versus heat flow rate obtained by DSC test of the photocurable composition of Example 7;

[0081] Figure 12 is a temperature versus heat flow rate curve obtained by DSC test of the photocurable composition of Example 8;

[0082] Figure 13(a) is a product display image of the photocurable composition of Example 9 processed by a 3D printer, and Figure 13(b) is a tension rod prepared in Example 15;

[0083] Figure 14 is a product display image of the photocurable composition of Example 10 prepared by 3D printing;

[0084] Figure 15 is a product display diagram of the photocurable composition of Example 11 prepared by 3D printing.

[0085] Figure 16 is a product display diagram of the photocurable composition of Example 12 prepared by 3D printing;

[0086] Figure 17 shows the photodegradation curve of the photocurable composition of Example 13 under irradiation with an 820 nm NIR laser source;

[0087] Figure 18 shows the photodegradation curve of the photocurable composition of Example 14 under irradiation with an 820 nm NIR laser source.

[0088] Figure 19 shows the stress-strain curve of the product prepared by 3D printing using the photocurable composition of Example 15. Detailed Implementation

[0089] The embodiments of the present invention will now be described. However, the present invention is not limited to the embodiments described below. In the embodiments described below, the constituent elements (including element steps, etc.) are not essential unless specifically stated otherwise. The same applies to numerical values ​​and their ranges; the present invention is not limited thereto.

[0090] In this article, "(meth)acrylic acid" refers to acrylic acid or methacrylic acid, "(meth)acrylate" refers to acrylate or methacrylate, and "(meth)acryloyl" refers to acryloyl or methacryloyl.

[0091] In addition, in this article, numerical ranges are used to indicate that the numerical values ​​recorded before and after are the ranges of the minimum and maximum values, respectively.

[0092] This article discloses specific values ​​of relevant features (including the endpoints of the range) that can be combined to form a new range.

[0093] In this invention, the prefix "C" n -C m "In each case, it indicates that the number of carbon atoms contained in the group is nm."

[0094] "Halogen" refers to fluorine, chlorine, bromine, and iodine. In this invention, it is preferred that the halogen includes F, Cl, or combinations thereof. "Halogenation" means substitution by one or more identical or different halogen atoms.

[0095] The term "C" used alone or in combination in this article n -C m "alkyl" and "C" n -C m"Unbranched or branched alkyl" refers to a branched or unbranched saturated hydrocarbon group having 1-20 carbon atoms, preferably 1-12, more preferably 1-8, and particularly preferably 1-6, such as 1-5 or 1-4 carbon atoms, for example, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3- Dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, and their isomers. C1-C8 alkyl groups can be methyl, ethyl, propyl, isopropyl, n-butyl, 2-butyl, tert-butyl, pentyl, isopentyl, hexyl, heptyl, octyl, and their isomers. C1-C6 alkyl groups can be methyl, ethyl, propyl, isopropyl, n-butyl, 2-butyl, tert-butyl, pentyl, isopentyl, hexyl, and their isomers. C1-C4 alkyl groups can be methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, and their isomers.

[0096] The term "C2-C" is used in this article. m"Alkenyl" refers to a branched or unbranched unsaturated hydrocarbon group having 2-m, for example 2-20 or 2-12, preferably 2-6, more preferably 2-4 carbon atoms and having a double bond in any position, such as vinyl, 1-propenyl, 2-propenyl, 1-methylvinyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 2-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-1-butenyl, 2-methyl-1-butenyl, 3-methyl-1-butenyl, 1-methyl-2-butenyl, 2-methyl-2-butenyl, 3-methyl -2-Butenyl, 1-Methyl-3-butenyl, 2-Methyl-3-butenyl, 3-Methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-ethyl-1-propenyl, 1-ethyl-2-propenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 2-methyl-1-pentenyl, 3-methyl-1-pentenyl, 4-methyl-1-pentenyl, 1-methyl-2-pentenyl, 2-methyl-2-pentenyl, 3-methyl-2-pentenyl, 4-methyl-2-pentenyl, 1-methyl-3-pentenyl, 2-methyl-3-pentenyl 3-methyl-3-pentenyl, 4-methyl-3-pentenyl, 1-methyl-4-pentenyl, 2-methyl-4-pentenyl, 3-methyl-4-pentenyl, 4-methyl-4-pentenyl, 1,1-dimethyl-2-butenyl, 1,1-dimethyl-3-butenyl, 1,2-dimethyl-1-butenyl, 1,2-dimethyl-2-butenyl, 1,2-dimethyl-3-butenyl, 1,3-dimethyl-1-butenyl, 1,3-dimethyl-2-butenyl, 1,3-dimethyl-3-butenyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 3,3-dimethyl-3-butenyl The C2-C6 alkenyl group can be vinyl, propenyl, 1-butenyl, 2-butenyl, isobutenyl, 1-pentenyl, 2-pentenyl, neopentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, isohexenyl, neohexenyl, and their isomers.C2-C4 alkenyl groups can be vinyl, 1-propenyl, 2-propenyl, 1-methylvinyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 2-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl, and their isomers.

[0097] The term "C3-C" is used in this article. m "Cycloalkyl" refers to a saturated alicyclic monocyclic group having 3-m, for example 3-20, preferably 3-8, and more preferably 5-6 cyclic carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl.

[0098] Term "C" n -C m "alkoxy" and "C" n -C m "Alkylthio" refers to the group with a C-position of 10 ... n -C m alkyl corresponding to open chain C n -C m In alkanes, any carbon atom is bonded with either an oxygen atom or a sulfur atom as a linking group. n -C m Alkyl groups, such as C1-C 20 Alkoxy (or thio) group, preferably C1-C 12 The alkoxy (or thio) group, more preferably C1-C8 alkoxy (or thio) group, particularly preferably C1-C6 alkoxy (or thio) group, and especially preferably C1-C4 alkoxy (or thio) group. C1-C8 alkoxy groups can be methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, 2-butoxy, tert-butoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, isooctoxy, and their isomers. C1-C4 alkoxy groups can be methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, and their isomers. C1-C8 alkylthio groups can be methylthio, ethylthio, propylthio, isopropylthio, n-butylthio, 2-butylthio, tert-butylthio, pentoxy, isopentoxy, hexoxy, heptoxy, octylthio, isooctylthio, and their isomers. C1-C4 alkylthio groups can be methylthio, ethylthio, propylthio, isopropylthio, n-butylthio, and their isomers.

[0099] For Y + The heterocycles mentioned in Y, which have 8-18 ring members and include 1 or 2 nitrogen atoms as ring members, are preferably bicyclic or tricyclic heterocycles with 8-14 ring members and including 1 nitrogen atom as a ring member.

[0100] Photocurable compositions

[0101] The first aspect of this disclosure relates to a photocurable composition comprising the following components:

[0102] (a) at least one polymethyl benzoin compound, which serves as an infrared-absorbing photosensitizer;

[0103] (b) at least one photopolymerization initiator;

[0104] (c) at least one free radical photopolymerizable compound;

[0105] (d) at least one electron-donating reducing agent; and

[0106] (e) At least one arylphosphine compound.

[0107] The photocurable composition according to the present invention is particularly suitable for near-infrared light source curing. In a preferred embodiment, the photocurable composition is a free radical polymerizable near-infrared photocurable composition.

[0108] Component (a): Polymethyl benzoic acid compound as an infrared photosensitizer

[0109] In a preferred embodiment, the polymethyl benzoin compound as component (a) is selected from polymethyl benzoin compounds having the structure of formula (I):

[0110] Y + This refers to a heterocycle with 8-18 ring members, including one or two nitrogen atoms as ring members, and carrying a positive charge.

[0111] Y represents a heterocycle with 8-18 ring members and containing 1 or 2 nitrogen atoms as ring members, consisting of bicyclic, tricyclic, or more rings.

[0112] Y + The heterocycle in the definition of Y can have one or more radicals selected from halogens, CN, nitro, C1-C. 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups, C1-C 12 Branched or unbranched alkylthio or phenylthio substituents, wherein the C1-C 12 Branched or unbranched alkyl groups, the C1-C 12 Branched or unbranched alkoxy groups, the C1-C 12 The alkyl group in a branched or unbranched alkylthio group can be separated by one or more non-adjacent oxygen atoms;

[0113] Preferred Y + / Y represents the structural units shown below:

[0114] Indole salt / indole

[0115] Phenyl[e]indole salt / phenyl[e]indole

[0116] And / or phenyl[c,d]indole salt / phenyl[c,d]indole,

[0117] The indole salt / indole, phenyl[e]indole salt / phenyl[e]indole, and phenyl[c,d]indole salt / phenyl[c,d]indole may have one or more naphthalene rings on their benzene or naphthalene rings, preferably one or two selected from halogens, CN, nitro, C1-C. 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups, C1-C 12 Branched or unbranched alkylthio or phenylthio substituents, wherein the C1-C 12 Branched or unbranched alkyl groups, the C1-C 12 Branched or unbranched alkoxy groups, the C1-C 12 The alkyl group in a branched or unbranched alkylthio group can be separated by one or more non-adjacent oxygen atoms;

[0118] R1 is selected from C1-C 12 Branched or unbranched alkyl groups and C1-C 12 Branched or unbranched alkoxy groups, wherein the C1-C 12 Branched or unbranched alkyl groups and C1-C 12 Branched or unbranched alkoxy groups can be separated by one or more non-adjacent oxygen atoms, such as –[-CH2CHR-O-]. n The polyether shown is n, which is 1-6, and R is H or CH3;

[0119] The positions of the cyclic carbon indicated by the arrows are the connection sites with the polymethyl tannin chain;

[0120] More preferred Y + / Y represents the structural units shown below:

[0121] and / or

[0122] R1 is selected from C1-C 12 Branched or unbranched alkyl groups and C1-C 12 Branched or unbranched alkoxy groups, wherein the C1-C 12 Branched or unbranched alkyl groups and C1-C 12 Branched or unbranched alkoxy groups can be separated by one or more non-adjacent oxygen atoms, such as –[-CH2CHR-O-]. nThe polyethers shown are 1-6, and R is H or CH3; and

[0123] R2 and R3 are independently selected from H, halogen, CN, nitro, C1-C. 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups, C1-C 12 Branched or unbranched alkylthio or phenylthio, wherein the C1-C 12 Branched or unbranched alkyl groups, the C1-C 12 Branched or unbranched alkoxy groups, the C1-C 12 The alkyl group in a branched or unbranched alkylthio group can be separated by one or more non-adjacent oxygen atoms;

[0124] The positions of the cyclic carbon indicated by the arrows are the connection sites with the polymethyl tannin chain;

[0125] n1 and n2 are independently 0, 1 or 2; preferably 0 or 1, more preferably 1;

[0126] B and C are independently selected from H, C1-C 12 Alkyl groups, or together with the carbon atoms that connect them, form five-membered or six-membered rings;

[0127] A is selected from the structures shown in A-1 to A-13:

[0128] Or C1-C 12 Branched or unbranched alkoxy groups (A-13);

[0129] in

[0130] * indicates the connection point with the structure of equation (I).

[0131] Wherein, the "R2 and R2" groups may be the same or different, and each is independently selected from hydrogen, halogen, C1-C6 branched or unbranched alkyl, C1-C6 branched or unbranched alkoxy, C1-C6 branched or unbranched alkylthio or phenylthio.

[0132] Preferably, group A is selected from the structures shown in A-1, A-2, A-4, A-5 or A-7 to A-13;

[0133] When group A is group A-1 or A-2, n3 is 0; when group A is one of groups A-3 to A-13, n3 is 1.

[0134] and X - Indicates counterions.

[0135] In one embodiment, R1 is selected from C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy, wherein the C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy may be separated by one or two non-adjacent oxygen atoms.

[0136] In one embodiment, R2 is selected from H, halogen, nitro, C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy, wherein the C1-C6 branched or unbranched alkyl and the C1-C6 branched or unbranched alkoxy can be separated by one or two non-adjacent oxygen atoms, more preferably R2 is selected from H, halogen, nitro and C1-C6 branched or unbranched alkoxy, wherein the C1-C6 branched or unbranched alkoxy can be separated by one non-adjacent oxygen atom.

[0137] In one embodiment, R3 is selected from H, C1-C6 branched or unbranched alkyl groups and C1-C6 branched or unbranched alkoxy groups, wherein the C1-C6 branched or unbranched alkyl groups and the C1-C6 branched or unbranched alkoxy groups may be separated by one or two non-adjacent oxygen atoms, more preferably R3 is selected from H and C1-C6 branched or unbranched alkoxy groups.

[0138] In one embodiment, B and C are independently H or form a five- or six-membered ring together with the carbon atom connecting them. In another embodiment, B and C form a five- or six-membered ring together with the carbon atom connecting them. In a preferred embodiment, the five- or six-membered ring has only one carbon-carbon unsaturated double bond.

[0139] In one embodiment, the "R2 and R2" groups may be the same or different, each independently selected from hydrogen or C1-C6 branched or unbranched alkyl groups, preferably hydrogen or C1-C6 branched or unbranched alkyl groups. In one embodiment, the "R2 and R2" groups may be the same or different, each independently selected from C1-C6 branched or unbranched alkyl groups.

[0140] In one implementation, X - This indicates that the counterion is selected from one of the following groups: BF4 - [B(Ph4)] - PF6 - SbF6 - AsF6 - [PF3(C2F5)3] - [Al(OC(CF3)3)4] - [B(PhF5)4] - [B(Ph(CF3)2)4] - [((CF3)2SO2)2N] - [(CF3)2SO2)3C]- Cl - ,Br - F - [Al(Ot-C4F9)4] - [Al(O-(i-C3F7)CH3)4] - [C(O-SO2CF3)3] - [nC] 12 H 25- TsO] - Or [NTf2] - ,

[0141] BF4 is preferred. - [B(Ph4)] - PF6 - SbF6 - AsF6 - [PF3(C2F5)3] - [Al(OC(CF3)3)4] - [B(PhF5)4] - [B(Ph(CF3)2)4] - [((CF3)2SO2)2N] - [(CF3)2SO2)3C] - [Al(Ot-C4F9)4] - [Al(O-(i-C3F7)CH3)4] - Or [NTf2] - ,

[0142] More preferably, [PF3(C2F5)3] - [Al(OC(CF3)3)4] - [B(Ph4)] - PF6 - [B(PhF5)4] - [B(Ph(CF3)2)4] - [((CF3)2SO2)2N] - [(CF3)2SO2)3C] - [Al(Ot-C4F9)4] - or [Al(O-(i-C3F7)CH3)4] - .

[0143] In the compound of formula (I), when the A group is A-1 or A-2 and Y + R1 in Y is C1-C 12 Branched or unbranched alkyl groups or C1-C 12When the alkoxy group is branched or unbranched, the structural part of formula (I) is completely uncharged, X is absent, and when R 2 When the group is one of groups A-3 to A-13, the entire structural part of formula (I-1) carries a positive charge:

[0144] Where Y + Y, A, B, C, n1, n2 are defined as above.

[0145] In the compound of formula (I), when A is selected from A-1 or A-2, X does not exist, that is, n3 is 0.

[0146] When A is selected from one of A-3 to A-13, the entire structure of formula (I-1) carries a positive charge, and X - As defined above, n3 is 1.

[0147] In this invention, the polymethyl benzoic acid compound of formula (I) comprises the structural part of formula (I-1) and, if present, the counterion X. - .

[0148] In the polymethyl benzoic acid compound of formula (I) of the present invention and the structural part of formula (I-1) therein, n1 and n2 are independently 0, 1 or 2, and n3 is independently 0 or 1. B and C independently represent H, Cl-C 12 Alkyl groups, together with the carbon atoms attached to them, form five- or six-membered rings. When n1 and n2 are both 0, the compound of formula (I) is a trimethylolamine compound; when n1 is 0 and n2 is 1, the compound of formula (I) is a pentamethylolamine compound; when n1 and n2 are both 1, the compound of formula (I) is a heptamethylolamine compound; when n1 and n2 are both 1, and B and C, together with the carbon atoms attached to them, form five- or six-membered rings, the compound of formula (I) is a heptamethylolamine compound containing a five- or six-membered ring in the middle position. In a preferred embodiment of the invention, the compound of formula (I) is a trimethylolamine compound, wherein n1 and n2 are both 0. In another preferred embodiment of the invention, the compound of formula (I) is a pentamethylolamine compound, wherein n1 is 0 and n2 is 1. In yet another preferred embodiment of the invention, the compound of formula (I) is a heptamethylolamine compound in which B and C, together with the carbon atoms attached to them, form five-membered rings, wherein n1 and n2 are 1.

[0149] In the polymethylhexanetin compound of formula (I) of the present invention, (X) - ) n3 If present, it represents the counter ion of the structural part of formula (I-1), which depends on the type of A group; it may not exist at all or may be an anion.

[0150] When the entire structure of formula (I-1) is uncharged, n3 is 0, meaning that the compound of formula (I) does not contain any counterions.

[0151] In one embodiment of the invention, in the polymethyl benzoin compound of formula (I) of the invention and the structural portion of formula (I-1) contained herein, Y + Both Y and Y contain nitrogen-containing heterocycles, Y + The difference between Y and Y's structure is that Y... + The contained heterocyclic atom has a positive charge, while Y does not exhibit any charge.

[0152] Advantageously, the A group is A-1, A-4, A-5 or A-7 to A-13, or the A group is A-1, A-4, A-5, A-7, A-8, A-11, A-12 or A-13.

[0153] The preferred anthocyanin dye structures can be divided into the following four groups: S-1, S-2, S-3, and S-4:

[0154] Where A, R1, R2, R3, m and X - As defined above, m is 0-2 (e.g., 0, 1, and 2), and n is 0 or 1.

[0155] In one embodiment, the polymethyl benzoin compound, as component (a), is selected from one or more of the following compounds S1-S189:

[0156] When n=0, it is a quinary ring; when n=1, it is a hexagram.

[0157] Where barb1 refers to the A-1 group as defined above, where both R2 and R2 are -CH3, and barb2 refers to the A-2 group as defined above, where both R2 and R2 are -CH3.

[0158] The compounds of formula (I) of the present invention are known, for example, from Japanese Patent Application Publication No. 2010-209191, or can be prepared by conventional methods in the art.

[0159] Preferably, the polymethyl benzoic acid compound used as component (a) is selected from S132, S44 or a mixture thereof.

[0160] According to the present invention, the amount of the infrared absorbing photosensitizer as component (a) can be 0.001-5% by weight based on the total weight of the photocurable composition, for example 0.002% by weight, 0.005% by weight, 0.008% by weight, 0.01% by weight, 0.02% by weight, 0.03% by weight, 0.04% by weight, 0.05% by weight, 0.06% by weight, 0.07% by weight, 0.08% by weight, 0.09% by weight, 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.5% by weight, 0.8% by weight, 1% by weight, 1.5% by weight, 2% by weight, 2.5% by weight, 3% by weight, 3.5% by weight, 4% by weight, 4.5% by weight or 4.8% by weight, preferably 0.005-4% by weight, 0.01-3% by weight, 0.01-2% by weight, 0.01-1% by weight, 0.02-0.8% by weight, or 0.02-0.5% by weight.

[0161] Component (b): Photopolymerization initiator

[0162] According to one embodiment of the present invention, the photopolymerization initiator as component (b) can be a photopolymerization initiator capable of generating free radicals in the presence of component (a). Preferably, the photopolymerization initiator as component (b) is selected from photopolymerization initiators of iodonium salts, thiodonium salts, triazine compounds, and oxime esters, with iodonium salts being more preferred.

[0163] As a suitable iodonium salt compound for the present invention, an iodonium salt compound comprising formula (II) is preferred.

[0164] Among them, R1'-R6' can be the same or different, and are independently selected from H, halogen, nitro, C1-C. 20 Branched or unbranched alkyl groups, C1-C 20 Branched or unbranched alkoxy groups and C1-C 20 Branched or unbranched alkylthio groups, and X' - As shown above, X in compound (I) - As defined. In one implementation, R1'-R6' can be the same or different, and are independently selected from H, C1-C 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups and C1-C 12 Branched or unbranched alkylthio groups. In one embodiment, R1'-R6' can be the same or different, and are independently selected from H and C1-C. 12 Branched or unbranched alkyl groups. In one embodiment, R1', R3', R4', and R6' are H, and R2' and R5' are C1-C. 12Branched or unbranched alkyl groups, preferably C1-C6 branched or unbranched alkyl groups, especially methyl groups.

[0165] In one embodiment, X in the compound of formula (I) - With X' in compound (II) - They are the same.

[0166] The iodonium salt of formula (II) of the present invention is known and can be prepared by conventional methods in the art.

[0167] In an advantageous embodiment of the invention, the iodonium salt initiator of formula (II) as component (b) is one or more selected from the following compounds IS1-IS41:

[0168] Preferably, the photopolymerization initiator used as component (b) is selected from IS1, IS41 or a mixture thereof.

[0169] The amount of photopolymerization initiator as component (b) can be 0.1-10% by weight based on the total weight of the photocurable composition, for example 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1% by weight, 1.2% by weight, 1.5% by weight, 1.8% by weight, 2% by weight, 2.5% by weight, 3% by weight, 3.5% by weight, 4% by weight, 4.5% by weight, 5% by weight, 5.5% by weight, 6% by weight, 6.5% by weight, 7% by weight, 7.5% by weight, 8% by weight, 8.5% by weight, 9% by weight, 9.5% by weight, preferably 0.5-8% by weight or 0.5-5% by weight.

[0170] In one embodiment, the weight ratio of the infrared absorbing photosensitizer as component (a) to the photopolymerization initiator as component (b) is 100:1 to 1:100 (e.g., 90:1, 80:1, 70:1, 60:1, 50:1, 40:1, 30:1, 20:1, 10:1, 8:1, 5:1, 2:1, 1:1, 1:2, 1:5, 1:8, 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80 or 1:90), preferably 10:1 to 1:100 or 1:1 to 1:100, more preferably 1:10 to 1:100.

[0171] Component (c): Free radical photopolymerizable compound

[0172] According to a preferred embodiment of the present invention, the free radical photopolymerizable compound (c) is a free radical polymerizable compound containing an olefinically unsaturated group, particularly a compound containing a free radical polymerizable unsaturated carbon-carbon double bond. The free radical polymerizable compound may be in the form of a monomer and / or a resin (including oligomers or prepolymers).

[0173] In one embodiment, the amount of the free radical photopolymerizable compound as component (c) can be 50-98.5% by weight (e.g., 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight, 95% by weight, 96% by weight, 97% by weight, 97.1% by weight, 97.2% by weight, 97.3% by weight, 97.5% by weight, 97.6% by weight, 97.7% by weight, 97.8% by weight, 97.9% by weight, 98% by weight, 98.1% by weight, 98.2% by weight, 98.3% by weight, or 98.4% by weight), preferably 60-98.5% by weight, 70-98.5% by weight, 70-98.3% by weight, 80-98.5% by weight, 80-98.2% by weight, 85-98% by weight, or 90-98% by weight.

[0174] In one embodiment, the free radical photopolymerizable compound comprises a free radical polymerizable monomer and a free radical polymerizable resin. The weight ratio of the free radical polymerizable monomer to the free radical polymerizable resin can be 15:1 to 1:10 (e.g., 14:1, 13:1, 12:1, 11:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or 1:9), preferably 12:1 to 1:5, more preferably 10:1 to 1:1 or 8:1 to 2:1.

[0175] In one embodiment, the total weight of the free radical polymerizable monomers (especially monofunctional and / or difunctional compounds) in the photocurable composition of the present invention can be 10-85% by weight (e.g., 15% by weight, 20% by weight, 30% by weight, 40% by weight, 50% by weight, 60% by weight, 70% by weight, 80% by weight or 82% by weight), preferably 20-82% by weight, 30-82% by weight, 40-80% by weight or 50-80% by weight.

[0176] In one embodiment, the amount of free radical polymerizable resin, based on the total weight of the photocurable composition, can be 12-80% by weight, for example 15% by weight, 20% by weight, 25% by weight, 30% by weight, 40% by weight, 50% by weight, 60% by weight, 70% by weight, preferably 15-75% by weight, 15-60% by weight, or 15-45% by weight.

[0177] In one embodiment, the radical photopolymerizable compound comprises at least one of a radical polymerizable resin, a radical polymerizable monomer with two or more functional groups, and a monofunctional radical polymerizable monomer. Preferably, the radical photopolymerizable compound comprises a radical polymerizable resin and a radical polymerizable monomer with two or more functional groups, or the radical photopolymerizable compound comprises a radical polymerizable resin and a monofunctional radical polymerizable monomer, or the radical photopolymerizable compound comprises a radical polymerizable resin, a radical polymerizable monomer with two or more functional groups, and a monofunctional radical polymerizable monomer.

[0178] Free radical polymerizable monofunctional compounds (monomers)

[0179] Free radical polymerizable monofunctional compounds have low viscosity and can be used as photoreactive diluents. Examples include (meth)acrylates, (meth)acryloyl compounds, ethylene derivatives, styrene compounds, anhydrides containing olefinic unsaturated double bonds (maleic anhydride), N-vinylformamides, and monofunctional compounds with cyclic structures, such as N-vinylpyrrolidone and acryloylmorpholine. In a preferred embodiment, the free radical polymerizable monomer comprises a monofunctional compound with a cyclic structure, such as N-vinylpyrrolidone and acryloylmorpholine.

[0180] The following examples are preferred as (meth)acrylate compounds:

[0181] (Meth)acrylic acid C1-C 18 Alkyl esters, such as (meth)acrylic acid C1-C 12 Alkyl esters or C1-C6 alkyl esters of (meth)acrylate, examples of which include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, isooctyl acrylate (2-EHA), isodecyl acrylate (IDA), lauryl (meth)acrylate, stearyl (meth)acrylate, and 2-isobutylenoyl ethoxyphthalate.

[0182] Hydroxyl-functionalized (meth)acrylates, such as hydroxy C1-C6 alkyl (meth)acrylates, examples of which are 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, glycidyl methacrylate, etc.

[0183] (Meth)acrylates with a cyclic skeleton, such as isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, γ-butyrolactone (meth)acrylate, γ-butyrolactone (meth)acrylate, tricyclodecyl (meth)acrylate; and

[0184] (Meth)acrylates containing alkoxy groups such as EO and PO (e.g., having 1-10, such as 2, 4, 6, 6 or 8, preferably 1-5 EO and / or PO units), such as methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and phenoxyethyl (meth)acrylate.

[0185] Examples of (meth)acryloyl compounds include acryloylmorpholine, 2-methacryloylethoxysuccinate, N,N-dimethylacrylamide, N,N-diethylacrylamide, and N,N-dipropylacrylamide.

[0186] Chloromethylstyrene and α-methylstyrene can be mentioned as styrene compounds.

[0187] Anhydrides containing olefinic unsaturated double bonds can include maleic anhydride, etc.

[0188] Vinyl esters may be mentioned as ethylene derivatives, preferably vinyl esters of C2-C6 monocarboxylic acids, such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl hexanoate, or mixtures thereof.

[0189] The total weight of the free radical polymerizable monofunctional compound in monomer form based on the photocurable composition of the present invention can be 10-85% by weight (e.g., 15% by weight, 20% by weight, 30% by weight, 40% by weight, 50% by weight, 60% by weight, 70% by weight, 80% by weight or 82% by weight), preferably 20-82% by weight, 30-82% by weight, 40-80% by weight or 50-80% by weight.

[0190] Free radical polymerizable compounds (monomers) with two or more functional groups.

[0191] Two-functionalized radical polymerizable compounds have higher reactivity than monofunctionalized compounds, which can improve the surface curability of inks. Their viscosity is lower than that of radical polymerizable trifunctionalized compounds. By combining them with monofunctionalized compounds, they can serve as excellent diluents for trifunctionalized and more functionalized compounds, thereby reducing the viscosity and increasing the reactivity of the photocurable compositions and photosensitive inks of this invention.

[0192] As difunctional radical polymerizable compounds, examples include di(meth)acrylates of diols or triols having 2-12 carbon atoms, such as 2, 4, 6, 8, or 10, with a number average molecular weight not exceeding 1500, for example, not exceeding 1200, of polyethylene glycol or polypropylene glycol di(meth)acrylates, wherein these compounds are optionally modified with EO or PO, such as with 5-15 EOs and / or POs; specific examples include 2-hydroxy-3-acryloyloxypropyl(meth)acrylate, neopentyl glycol di(meth)acrylate. Acrylic esters, 1,3-butanediol di(meth)acrylate, 2-methyl-1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, ethoxylated 1,6-hexanediol di(meth)acrylate, neopentanediol di(meth)acrylate, propoxylated neopentanediol di(meth)acrylate Acrylates, polyethylene glycol #400 di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol #400 di(meth)acrylate, polyethylene glycol #700 di(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol #200 di(meth)acrylate, polyethylene glycol #600 di(meth)acrylate Acrylic esters, polyethylene glycol #1000 di(meth)acrylate, ethoxylated polypropylene glycol #700 di(meth)acrylate, polypropylene glycol #400 di(meth)acrylate, bisphenol A type di(meth)acrylate (may contain different EO, PO, and other alkoxy segments), hydrogenated bisphenol A type di(meth)acrylate (may contain different EO, PO, and other alkoxy segments), dicyclopentadiene, 2,2-bis(4-(methacryloyloxypolyethoxy)phenyl)propane (average number of EO units is 5-15 per molecule), etc. One or more of these can be used.

[0193] Preferred are di(meth)acrylates of polyethylene glycol and 2,2-bis(4-(methacryloyloxypolyethoxy)phenyl)propane (with an average number of EO units of 5-15 per molecule) and mixtures thereof, with a number average molecular weight not exceeding 1200 (e.g., not exceeding 800).

[0194] The total weight of the free radical polymerizable compound of the 2 functional groups based on the photocurable composition of the present invention can be 0-80% by weight or 10-80% by weight, for example 5% by weight, 20% by weight, 30% by weight, 40% by weight, 50% by weight, 60% by weight or 70% by weight.

[0195] Free radical polymerizable compounds (monomers) with 3 or more functional groups.

[0196] As a free radical polymerizable compound with three or more functional groups, one may refer to compounds having three or more (meth)acrylate groups. Specific examples include: trimethylolpropane triacrylate, trimethylolmethane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetra(meth)acrylate, tetramethylolmethane tetraacrylate, ethylene oxide-modified phosphate triacrylate, propylene oxide-modified phosphate triacrylate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, di(trimethylolpropane)tetraacrylate, or their sesquioxane-modified derivatives, etc., representing multifunctional acrylates, or their corresponding methacrylate monomers, ε-caprolactone-modified triacryloyloxyethyl isocyanurate, etc.

[0197] The amount of the free radical polymerizable compound with 3 or more functional groups can be 0-80% by weight or 5-80% by weight based on the total weight of the photocurable composition of the present invention, for example, 10, 20, 30, 40, 50, 60 or 70% by weight.

[0198] Free radical polymerizable resins

[0199] In one embodiment of the invention, the free radical photopolymerizable compound comprises a free radical polymerizable compound in the form of a resin (including oligomers or prepolymers), also referred to as a free radical polymerizable resin. Examples of free radical polymerizable resins include epoxy (meth)acrylate resins, polyester (meth)acrylates, polyurethane (meth)acrylates, olefinically unsaturated polyesters, amino (meth)acrylate resins, and photo-imaging alkali-soluble resins. Advantageously, according to the invention, epoxy (meth)acrylate resins, polyester (meth)acrylates, polyurethane (meth)acrylates, or combinations thereof are used.

[0200] [Amended according to Rule 26 09.02.2026] Preferred epoxy (meth)acrylate resins are bisphenol A epoxy (meth)acrylate, bisphenol A epoxy acrylate diluted with tripropylene glycol dimethacrylate, or combinations thereof, such as bisphenol A epoxy acrylate WSR-U125 from Wuxi Resin Factory, bisphenol A epoxy acrylate 621A-80 diluted with 20% tripropylene glycol diacrylate from Chang Hsing Chemical Co., Ltd. in Taiwan, modified bisphenol A epoxy acrylate 623-100 from Chang Hsing Chemical Co., Ltd. in Taiwan, and modified bisphenol A epoxy acrylate 6231A-80 diluted with 20% tripropylene glycol diacrylate from Chang Hsing Chemical Co., Ltd. in Taiwan.

[0201] Polyester (meth)acrylates are preferably hyperbranched polyester acrylate resins with high functionality, especially hyperbranched polyester acrylate resins with a functionality of 5-30, such as hyperbranched polyester acrylate prepolymers with a functionality of 6-20. Examples include hyperbranched polyester acrylate prepolymers 932-100 (6 functionality) from Wuxi Knox Company, and hyperbranched polyester acrylate prepolymers CN2300 (8 functionality), CN2301 (9 functionality), and CN2302 (16 functionality) from Sartoma Company, USA. Polyester (meth)acrylates also include polyester polyol acrylate resins diluted with 20% ethoxytrimethylolpropane triacrylate.

[0202] [Amended according to Rule 26, 09.02.2026] Polyurethane (meth)acrylates can be aliphatic polyurethane (meth)acrylates and / or aromatic polyurethane (meth)acrylates. Examples include aliphatic polyurethane hexaacrylates 6145-100, 6161-100, and aliphatic polyurethane diacrylates 611B-85 and 6141H-80 diluted with 15% 1,6-hexanediol diacrylate (HDDA) from Chang Hsing Chemical Co., Ltd., Taiwan; aliphatic polyurethane acrylate CN9013 (9-functionality) from Sartoma Chemical Co., Ltd., USA; aliphatic polyurethane acrylate CN966B85 (2-functionality) diluted with 15% 1,6-hexanediol diacrylate (HDDA) from Sartoma Chemical Co., Ltd., USA; and aliphatic polyurethane acrylate CN962 (2-functionality) from Zhanxin Resin (China) Co., Ltd. 220, Aromatic polyurethane acrylate (6 functionalities); Guangzhou Runao Chemical Materials Co., Ltd. 8091, a bifunctional polyurethane acrylate.

[0203] The functionality of the free radical polymerizable resin can be 2-20 (e.g., 3, 4, 5, 6, 8, 10, 12, 15, 18), preferably 2-12 or 2-8.

[0204] The number average molecular weight of the free radical polymerizable resin can be 600-5000 g / mol (e.g., 700, 800, 900, 1000, 1200, 1500, 2000, 3000, 4000 or 4500 g / mol), preferably 800-4000 g / mol.

[0205] In one embodiment, the free radical photopolymerizable compound comprises a free radical polymerizable resin and a monofunctional free radical polymerizable monomer, preferably the free radical polymerizable resin is a polyurethane (meth)acrylate, and the monofunctional free radical polymerizable monomer is a (meth)acryloyl group, such as acryloylmorpholine.

[0206] Component (d): Electron-donating reducing agent

[0207] The photocurable composition of the present invention comprises at least one electron-donating reducing agent (d). In one embodiment, the electron-donating reducing agent is selected from sulfinic acid and its salts, salts of ferrocyanide, ascorbic acid and its salts, phenylglycine compounds and aryl borates, preferably phenylglycine compounds and aryl borates, such as tetraphenylborate and N-phenylglycine.

[0208] In one embodiment, the weight ratio of the electron-donating reducing agent to the photopolymerization initiator is 5:1-1:50 (e.g., 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45 or 1:48), preferably 1:1-1:40, more preferably 1:2-1:20.

[0209] In one embodiment, the amount of the electron-donating reducing agent is 0.05-2.5% by weight (e.g., 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, or 2.2% by weight), preferably 0.08-1.2% by weight, based on the total weight of the photocurable composition.

[0210] Component (e): Arylphosphide compound

[0211] The arylphosphine compounds are particularly arylphosphine compounds having trivalent phosphorus atoms, such as phosphine compounds having 1-3 phenyl rings, like triphenylphosphine, and phosphites having 1-3 phenyl rings. In a preferred embodiment, the arylphosphine compound is selected from triphenylphosphine, triphenylphosphite, tri(nonylphenyl)phosphite, trimethylphenylphosphite, phenyl mono(2-ethylhexyl)phosphite, diphenyl monodecyl phosphite, diphenyl mono(tetrazyl)phosphite, tetraphenyl dipropylene glycol diphosphite, tetra(C... 12 -C 15 Alkyl)-4,4'-isopropylidene diphenyl diphosphite, 4,4'-butylidene bis(3-methyl-6-tert-butylphenyl tris(alkyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite and isodecyl diphenyl phosphite.

[0212] In a preferred embodiment, the arylphosphine compound is triphenylphosphine.

[0213] In one embodiment, the weight ratio of the arylphosphide compound to the photopolymerization initiator is 5:1 to 1:50 (e.g., 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40 or 1:45), preferably 1:1 to 1:40, more preferably 1:2 to 1:20.

[0214] In one embodiment, the weight ratio of the electron-donating reducing agent to the arylphosphide compound is 10:1-1:10 (9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or 1:9), preferably 5:1-1:5, more preferably 3:1-1:3.

[0215] In one embodiment, the amount of the arylphosphide compound is 0.05-2.5 wt% (e.g., 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt%, 0.12 wt%, 0.15 wt%, 0.18 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, 2 wt%, or 2.2 wt%), preferably 0.08-2 wt% or 0.08-1.2 wt%, based on the total weight of the photocurable composition.

[0216] Colorant

[0217] In one embodiment, the photocurable composition comprises at least one colorant, such as a white, blue, green, purple, yellow, red, or black colorant. These colorants may be pigments or dyes.

[0218] If pigments are used, the particle size of the pigments can be 1-200nm (e.g., 2, 4, 5, 8, 10, 20, 40, 50, 80, 100, 120, 150 or 180nm, preferably 1-150nm, 1-100nm or 1-50nm).

[0219] Colorants can be used alone or in mixtures of two or more.

[0220] As white pigments, those that can be mentioned include titanium dioxide, zinc oxide, magnesium oxide, zirconium oxide, aluminum oxide, barium sulfate, silicon dioxide, talc, mica, aluminum hydroxide, calcium silicate, aluminum silicate, hollow resin particles, and zinc sulfide.

[0221] Examples of black colorants include carbon, aniline black, and iron oxide. Examples of blue colorants include phthalocyanine blue. Examples of green colorants include phthalocyanine green and iodine green. Examples of purple colorants include crystal violet. Examples of yellow dyes include diazo yellow. Rhodamine B can also be mentioned.

[0222] The amount of the colorant is 0.05-20% by weight (e.g., 0.06%, 0.07%, 0.08%, 0.09%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.5%, or 3% by weight) based on the total weight of the photocurable composition, preferably 0.08-10% by weight, 0.08-5% by weight, or 0.1-2% by weight.

[0223] solvent

[0224] The photocurable composition of the present invention may optionally contain an organic solvent. The selection of the organic solvent is conventional. Examples of organic solvents include aromatic hydrocarbons such as benzene and toluene, halogenated alkanes such as chloroform, dichloromethane, and chloroethane, ketones such as acetone, butanone, and pentanone, alcohols such as methanol, ethanol, propanol, isopropanol, and ethylene glycol, and ethylene glycol ethers, ethylene glycol ether acetates, propylene glycol ethers, and propylene glycol ether acetates. The amount of solvent, based on the total weight of the photocurable composition, can be 0-20% by weight (e.g., 1% by weight, 2% by weight, 5% by weight, 8% by weight, 10% by weight, 15% by weight, or 18% by weight), or 0-15% by weight, or 0-10% by weight, or 0-5% by weight. In one embodiment, the photocurable composition of the present invention may also be solvent-free.

[0225] In one embodiment, the photocurable composition of the present invention comprises:

[0226] (a) 0.001-5% by weight of at least one polymethyl benzoic acid compound, which serves as an infrared absorbing photosensitizer;

[0227] (b) 0.1-10% by weight of at least one photopolymerization initiator;

[0228] (c) 60-98.5% by weight of at least one photopolymerizable compound;

[0229] (d) 0.05-2.5% by weight of at least one electron-donating reducing agent;

[0230] (e) 0.05-2.5% by weight of at least one arylphosphide compound; and

[0231] 0-20% by weight of solvent;

[0232] In each case, the total weight of the photocurable composition is used.

[0233] In one embodiment, the photocurable composition of the present invention comprises:

[0234] (a) 0.001-5% by weight of at least one polymethyl benzoic acid compound, which serves as an infrared absorbing photosensitizer;

[0235] (b) 0.1-10% by weight of at least one photopolymerization initiator;

[0236] (c) 70-98.5% by weight of at least one photopolymerizable compound and the light;

[0237] (d) 0.05-2% by weight of at least one electron-donating reducing agent;

[0238] (e) 0.05-2% by weight of at least one arylphosphine compound, and

[0239] 0-20% by weight of solvent;

[0240] In each case, the total weight of the photocurable composition is used.

[0241] In one embodiment, the photocurable composition of the present invention comprises:

[0242] (a) 0.001-5% by weight of at least one polymethyl benzoic acid compound, which serves as an infrared absorbing photosensitizer;

[0243] (b) 0.1-10% by weight of at least one photopolymerization initiator;

[0244] (c) 80-98.5% by weight of at least one photopolymerizable compound;

[0245] (d) 0.05-2.5% by weight of at least one electron-donating reducing agent; and

[0246] (e) 0.05-2.5% by weight of at least one arylphosphide compound;

[0247] In each case, the total weight of the photocurable composition is used.

[0248] In one embodiment, the photocurable composition of the present invention comprises:

[0249] (a) 0.001-0.5% by weight of at least one polymethyl benzoic acid compound, which serves as an infrared-absorbing photosensitizer;

[0250] (b) 0.1-10% by weight of at least one photopolymerization initiator;

[0251] (c) 85-98.5% by weight of at least one photopolymerizable compound;

[0252] (d) 0.05-2.5% by weight of at least one electron-donating reducing agent; and

[0253] (e) 0.05-2.5% by weight of at least one arylphosphide compound;

[0254] In each case, the total weight of the photocurable composition is used.

[0255] Uses and Products

[0256] One aspect of the invention relates to the use of the photocurable composition of the invention in 3D printing, particularly SLA 3D printing, wherein the photocurable composition is preferably processed using an NIR (laser) light source with an emission wavelength of 700-2000 nm, preferably 750-900 nm.

[0257] One aspect of the present invention relates to photocurable articles obtained from the photocurable composition of the present invention. The photocurable articles can be obtained by 3D printing, particularly SLA 3D printing, wherein the photocurable composition is preferably processed using an NIR (laser) light source with an emission wavelength of 700-2000 nm, preferably 750-900 nm.

[0258] Example

[0259] The following embodiments illustrate the present invention in detail, but the present invention is not limited to these embodiments. It should be noted that, unless otherwise specified, parts refer to parts by weight, amount refers to weight, and percentage refers to weight percentage.

[0260] raw material:

[0261] ACMO: 4-Acryloylmorpholine;

[0262] 220: Aromatic polyurethane acrylate; number average molecular weight (Mn) of 1000 g / mol, functionality of 6, purchased from ZN Resins (China) Co., Ltd.

[0263] LuCure8091: Bifunctional polyurethane acrylate, purchased from Guangzhou Runao Chemical Materials Co., Ltd.

[0264] Carbon black: 30nm particle size, purchased from Beijing Innocare Technology Co., Ltd.

[0265] Rhodamine B dye: purchased from Beijing Innocare Technology Co., Ltd.

[0266] method

[0267] 1. The test method for the curing rate of the composition is as follows:

[0268] Fourier transform infrared spectroscopy (FTIR) was used to analyze the characteristic peaks of acrylate double bonds in the cured coating film (ACMO, 820-773 cm⁻¹). -1 Use 1660-1600cm or other monomers or oligomers -1 The absorbance A t And the absorbance A0 at its characteristic peak before exposure. Then, the curing rate of the photopolymerization reaction of each component is calculated according to the following formula: Curing rate = ((A0-A0) / ... t ) / A0)×100%

[0269] When several polymerizable compounds are present, the curing rate is the average of the curing rates of the various polymerizable compounds.

[0270] 2. The test method for the thermal stability of the composition is as follows:

[0271] Using a Mettler differential calorimeter (DSC 1), the crucible containing the 3D printing photocurable composition was heated from 25°C at 10°C / min. -1 The temperature was increased to 250°C at a rate under nitrogen atmosphere. After testing, a temperature-to-heat-flow-rate curve was obtained, and the onset value of the first exothermic peak was determined as the thermal decomposition temperature of the 3D-printed photocurable composition.

[0272] 3. The 3D printing test method for the composition is as follows:

[0273] The photocurable composition was placed in the reservoir, and the near-infrared photocurable SLA 3D printer (Wuhan Duyi Technology Co., Ltd.) was debugged, with a suitable laser intensity set (approximately 125mW cm⁻¹). -2 ) and scanning speed (approximately 200 mm / s) -1After processing, the supporting structure is removed by cleaning with solvent, and then an 820nm LED light source (1.5W cm⁻¹) is used. -2 After post-curing, the printed product can be obtained.

[0274] 4. The test methods for the light absorption and photodegradation properties of the composition are as follows:

[0275] The photocurable composition was placed within a quartz sheet interlayer (45 mm long, 12 mm wide, and 1 mm thick), with an interlayer thickness of approximately 30 micrometers. The absorbance of the interlayer in the 400-900 nm range was measured using a Shimadzu UV-3600UV-vis-NIR spectrophotometer to obtain the light absorption curve of the 3D-printed photocurable composition. The interlayer was then irradiated with an 820 nm LED light source, and the absorption curves at different irradiation times were tested to determine the photodegradation properties of the photocurable composition.

[0276] 5. The mechanical performance testing methods for printed products are as follows:

[0277] The stress-strain curves of the printed tension bars were tested using an Instron 5969 electromechanical universal testing machine at a tensioning speed of 15 mm / min. Three tension bars of the same size were tested simultaneously to obtain the mechanical properties of the printed products.

[0278] Example 1 - Light absorption properties of the photocurable composition in the near-infrared region

[0279] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound. The specific formulation is shown in Table 1. The absorbance of the interlayer in the range of 400-900 nm was then measured using a Shimadzu UV-3600UV-vis-NIR spectrophotometer.

[0280] Table 1: Formulations of Photocurable Compositions

[0281] The light absorption curve test results of the photocurable composition prepared in Example 1 are shown in Figure 1. This 3D printing photocurable composition exhibits excellent light absorption properties in the NIR region, with a maximum absorption wavelength of approximately 800 nm, showing good compatibility with the 808 nm laser light source configured for near-infrared SLA 3D printing.

[0282] Example 2 - Light absorption properties of the photocurable composition in the near-infrared region

[0283] Compared with the composition of Example 1, the composition of Example 2 added infrared absorbing photosensitizer S44, used iodonium salt IS41 as an initiator, and changed the mass ratio between the components.

[0284] S132 and S44 were selected as infrared-absorbing photosensitizers, iodonium salt IS41 as an initiator, and acryloylmorpholine ACMO as a monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound. The specific formulation is shown in Table 2. The absorbance of the interlayer in the range of 400-900 nm was then measured using a Shimadzu UV-3600UV-vis-NIR spectrophotometer.

[0285] Table 2: Formulations of Photocurable Compositions

[0286] The light absorption curve test results of the photocurable composition prepared in Example 2 are shown in Figure 2. This 3D printing photocurable composition exhibits excellent light absorption properties in the NIR region, with a maximum absorption wavelength of approximately 800 nm, showing good compatibility with the 808 nm laser light source configured for near-infrared SLA 3D printing.

[0287] Example 3 - Polymerization curing rate and polymerization rate of photocurable compositions under near-infrared light source irradiation

[0288] S132 was selected as the infrared absorption photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound. The specific formulation is shown in Table 3. Exposure was performed according to the exposure conditions in Table 4, and the curing rate was then tested using Fourier transform infrared spectroscopy (FTIR).

[0289] Table 3: Formulations of Photocurable Compositions

[0290] Table 4: Exposure Conditions

[0291] The photopolymerization kinetics test results of the photocurable composition prepared in Example 3 are shown in Figures 3-4. Under irradiation with an 808nm NIR laser, the curing rate of the monomer and oligomers in this 3D printing photocurable composition can reach approximately 80%, and the peak polymerization rate can reach 40% s⁻¹. -1 This composition can achieve both a high curing rate and a fast polymerization rate, indicating that it has the potential to be used to prepare polymer materials through 3D printing.

[0292] Example 4 - Polymerization curing rate and polymerization rate of a carbon black-containing photocurable composition under near-infrared light irradiation

[0293] Compared with the composition of Example 3, the composition of Example 4 adds carbon black as a pigment additive.

[0294] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, triphenylphosphine as an arylphosphine compound, and carbon black as a pigment additive. The specific formulation is shown in Table 5. Exposure was performed according to the exposure conditions in Table 6, and the curing rate was then tested using Fourier transform infrared spectroscopy (FTIR).

[0295] Table 5: Formulations of Photocurable Compositions

[0296] Table 6: Exposure Conditions

[0297] The photopolymerization kinetics test results of the photocurable composition prepared in Example 4 are shown in Figures 5-6. This carbon black-containing 3D printing photocurable composition, under irradiation with an 808nm NIR laser, achieved a monomer and oligomer curing rate of approximately 80% and a peak polymerization rate of 27% s⁻¹. -1 It can achieve both a high curing rate and a fast polymerization rate. The addition of carbon black reduces the polymerization rate to some extent, but it still meets the requirements for printing. This indicates that the composition has the basis for preparing polymer materials through 3D printing and has the potential to prepare colored materials through NIR SLA 3D printing.

[0298] Example 5 - Polymerization curing rate and polymerization rate of photocurable compositions under near-infrared light source irradiation

[0299] Compared with the composition of Example 3, the composition of Example 5 added infrared absorbing photosensitizer S44, used iodonium salt IS41 as an initiator, and changed the mass ratio between the components.

[0300] S132 and S44 were selected as infrared-absorbing photosensitizers, iodonium salt IS41 as an initiator, and acryloylmorpholine ACMO as a monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound. The specific formulation is shown in Table 7. Exposure was performed according to the exposure conditions in Table 8, and the curing rate was then tested using Fourier transform infrared spectroscopy (FTIR).

[0301] Table 7: Formulations of Photocurable Compositions

[0302] Table 8: Exposure Conditions

[0303] The photopolymerization kinetics test results of the photocurable composition prepared in Example 5 are shown in Figures 7-8. Under irradiation with an 808nm NIR laser, the curing rate of the monomer and oligomers in this 3D printing photocurable composition can reach approximately 80%, and the peak polymerization rate can reach 27% s⁻¹. -1 This composition can achieve both a high curing rate and a fast polymerization rate, indicating that it has the potential to be used to prepare polymer materials through 3D printing.

[0304] Example 6 - Polymerization curing rate and polymerization rate of pigment-containing photocurable compositions under near-infrared light irradiation

[0305] Compared with the composition of Example 5, the composition of Example 6 adds Rhodamine B as a pigment additive.

[0306] S132 and S44 were selected as infrared-absorbing photosensitizers, IS41 as an initiator, and acryloylmorpholine (ACMO) as a monomer. 220 and LuCure8091 are oligomers, sodium tetraphenylborate is a reducing agent, triphenylphosphine is an arylphosphine compound, and rhodamine B is a pigment additive. A photocurable composition was prepared, and the specific formulation is shown in Table 9. Exposure was performed according to the exposure conditions in Table 10, and the curing rate was tested using Fourier transform infrared spectroscopy (FTIR).

[0307] Table 9: Formulations of Photocurable Compositions

[0308] Table 10: Exposure Conditions

[0309] The photopolymerization kinetics test results of the photocurable composition prepared in Example 6 are shown in Figures 9-10. Under irradiation with an 808nm NIR laser, the curing rate of this 3D printing photocurable composition reached approximately 78% for both monomers and oligomers, and the peak polymerization rate reached 23% s⁻¹. -1 It can achieve both a high curing rate and a fast polymerization rate. The addition of Rhodamine B reduces the polymerization rate to some extent, but it still meets the requirements for printing. This indicates that the composition has the basis for preparing polymer materials through 3D printing and has the potential to prepare colored materials through NIR SLA 3D printing.

[0310] Example 7 - Thermal stability of the photocurable composition

[0311] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound. The specific formulation is shown in Table 11. The thermal stability of the composition was then tested using a Mettler differential calorimeter (DSC 1).

[0312] Table 11: Formulations of Photocurable Compositions

[0313] Figure 11 shows the test results of the temperature versus heat flow rate of the photocurable composition prepared in Example 7. This 3D printing photocurable composition has good thermal stability, with an initial thermal reaction temperature of around 100°C, which can meet the requirements of actual printing and ensure accuracy and safety in the 3D printing process.

[0314] Example 8 - Thermal stability of the photocurable composition

[0315] Compared with the composition of Example 7, the composition of Example 8 added infrared absorbing photosensitizer S44, used iodonium salt IS41 as an initiator, and changed the mass ratio between the components.

[0316] S132 and S44 were selected as the infrared absorbing photosensitizers, iodonium salt IS41 was selected as the initiator, and acryloylmorpholine ACMO was selected as the monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound. The specific formulation is shown in Table 12. The thermal stability of the composition was then tested using a Mettler differential calorimeter (DSC 1).

[0317] Table 12: Formulations of Photocurable Compositions

[0318] Figure 12 shows the test results of the temperature versus heat flow rate of the photocurable composition prepared in Example 8. This 3D printing photocurable composition has good thermal stability, with an initial thermal reaction temperature of around 100°C, which meets the requirements of actual printing and ensures accuracy and safety during the 3D printing process.

[0319] Example 9 - Manufacturing 3D Printed Products via SLA 3D Printing

[0320] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. Using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound, a photocurable composition was formulated as shown in Table 13. The product was then manufactured using a near-infrared photocuring SLA 3D printer according to the printing parameters in Table 14. Post-curing was then performed using an 820nm LED light source (light intensity 1.5W cm⁻¹). -2 The time is 30 minutes.

[0321] Table 13: Formulations of Photocurable Compositions

[0322] Table 14: Printing Parameters

[0323] The printed product of the photocurable composition of Example 9 is shown in Figure 13(a), demonstrating that the composition has the ability to prepare polymer materials by 3D printing.

[0324] Example 10 - Manufacturing Colored 3D Printed Products via SLA 3D Printing

[0325] Compared with the photocurable composition of Example 9, the photocurable composition of Example 10 adds carbon black as a pigment additive.

[0326] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. Using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, triphenylphosphine as an arylphosphine compound, and carbon black as a pigment additive, a photocurable composition was prepared, the specific formulation of which is shown in Table 15. The material was then prepared using a near-infrared photocuring SLA 3D printer according to the printing parameters in Table 16. Post-curing was then performed using an 820nm LED light source (light intensity 1.5W cm⁻¹). -2 The time is 30 minutes.

[0327] Table 15: Formulations of Photocurable Compositions

[0328] Table 16: Exposure Conditions

[0329] The printed product of the photocurable composition in Example 10 is shown in Figure 14, demonstrating the composition's ability to prepare polymer materials via 3D printing. Furthermore, the addition of carbon black allows for coloring the product, resulting in a successfully manufactured black product.

[0330] Example 11 - Manufacturing 3D Printed Products via SLA 3D Printing

[0331] Compared to Example 9, the photocurable composition of Example 11 added infrared absorbing photosensitizer S44, used iodonium salt IS41 as an initiator, and changed the mass ratio between the components.

[0332] S132 and S44 were selected as infrared-absorbing photosensitizers, iodonium salt IS41 as an initiator, and acryloylmorpholine ACMO as a monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound, as shown in Table 17. The printed product was then prepared using a near-infrared photocurable SLA 3D printer according to the printing parameters in Table 18. Post-curing was then performed using an 820nm LED light source (light intensity 1.5W cm⁻¹). -2 The time is 30 minutes.

[0333] Table 17: Formulations of Photocurable Compositions

[0334] Table 18: Exposure Conditions

[0335] The 3D printed product of the photocurable composition of Example 11 is shown in Figure 15, demonstrating that the composition has the ability to prepare polymer materials by 3D printing.

[0336] Example 12 - Manufacturing Colored 3D Printed Products Using SLA 3D Printing

[0337] Compared with the photocurable composition of Example 11, the photocurable composition of Example 12 adds Rhodamine B as a pigment additive.

[0338] S132 and S44 were selected as infrared-absorbing photosensitizers, iodonium salt IS41 as an initiator, and acryloylmorpholine ACMO as a monomer. Using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, triphenylphosphine as an arylphosphine compound, and rhodamine B as a pigment additive, a photocurable composition was prepared, the specific formulation of which is shown in Table 19. The product was then printed using a near-infrared photocuring SLA 3D printer according to the printing parameters in Table 20. Post-curing was then performed using an 820nm LED light source (light intensity 1.5Wcm²). -2 The time is 30 minutes.

[0339] Table 19: Formulations of Photocurable Compositions

[0340] Table 20: Exposure Conditions

[0341] The printed product of the photocurable composition of Example 12 is shown in Figure 16, demonstrating the composition's ability to prepare polymer materials via 3D printing. Furthermore, the addition of Rhodamine B allows for coloring the product, resulting in a successful production of a red product.

[0342] Comparative Example 1 - SLA 3D Printing without Reducing Agent

[0343] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. 220 and LuCure8091 are oligomers, and triphenylphosphine is an arylphosphine compound. A photocurable composition was formulated, and the specific formulation is shown in Table 21. Compared with Example 9, this example does not include the reducing agent sodium tetraphenylborate. The product was then prepared using a near-infrared photocurable SLA 3D printer according to the printing parameters in Table 22.

[0344] Table 21: Formulations of Photocurable Compositions

[0345] Table 22: Printing Parameters

[0346] Compared to Example 9, the photocurable composition of Comparative Example 1 failed to successfully print a finished product, indicating that the electron-donating reducing agent plays a significant and essential role in the 3D printing photocurable composition. Comparative Example 2 – SLA 3D printing comparison without arylphosphine compounds.

[0347] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. 220 and LuCure8091 are oligomers, and sodium tetraphenylborate is used as the reducing agent to formulate a photocurable composition. The specific formulation is shown in Table 23. Compared with Example 9, this example does not contain arylphosphine compounds. The product was then prepared using a near-infrared photocurable SLA 3D printer according to the printing parameters in Table 24.

[0348] Table 23: Formulations of Photocurable Compositions

[0349] Table 24: Printing Parameters

[0350] Compared to Example 9, the photocurable composition of Comparative Example 2 failed to successfully print a finished product, indicating that the arylphosphine compound plays a significant and indispensable role in the photocurable composition for 3D printing. Comparative Example 3 – SLA 3D printing comparison with and without reducing agent and with arylphosphine compound.

[0351] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. 220 and LuCure8091 are oligomers, and a photocurable composition was formulated as shown in Table 25. Compared to Example 9, this example did not include a reducing agent or arylphosphine compounds. The product was then prepared using a near-infrared photocurable SLA 3D printer according to the printing parameters in Table 26.

[0352] Table 25: Formulations of Photocurable Compositions

[0353] Table 26: Printing Parameters

[0354] Compared to Example 9, the photocurable composition of Comparative Example 3 could not successfully print a finished product, indicating that the electron-donating reducing agent and arylphosphine compound play a significant role in the 3D printing photocurable composition and are both indispensable.

[0355] Example 13 - Photolysis reaction under NIR light source irradiation

[0356] This embodiment illustrates that the photoinitiator system in the 3D printing photocurable composition of the present invention can undergo a photolysis reaction.

[0357] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound. The specific formulation is shown in Table 27. An 820nm LED light source (luminous intensity 825mW / cm²) was used. -2 The composition in the interlayer was irradiated for different durations, and the absorbance of the interlayer in the range of 400-900nm was measured using a Shimadzu UV-3600UV-vis-NIR spectrophotometer.

[0358] Table 27: Formulations of Photocurable Compositions

[0359] The photolysis curve of the photocurable composition of Example 13 is shown in Figure 17. The absorbance of the photocurable composition decreases rapidly over time, indicating that the photoinitiator system in the composition can undergo photolysis under near-infrared light source irradiation.

[0360] Example 14 - Photolysis reaction under NIR light source irradiation

[0361] Compared to the photocurable composition of Example 13, the photocurable composition of Example 14 added infrared absorbing photosensitizer S44, used iodonium salt IS41 as an initiator, and changed the mass ratio between the components.

[0362] S132 and S44 were selected as infrared-absorbing photosensitizers, iodonium salt IS41 as an initiator, and acryloylmorpholine ACMO as a monomer. A photocurable composition was prepared using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound. The specific formulation is shown in Table 28. An 820nm LED light source (luminous intensity 825mW / cm²) was used. -2 The composition in the interlayer was irradiated for different durations, and the absorbance of the interlayer in the range of 400-900nm was measured using a Shimadzu UV-3600UV-vis-NIR spectrophotometer.

[0363] Table 28: Formulations of Photocurable Compositions

[0364] The photolysis curve of the photocurable composition in Example 14 is shown in Figure 18. The absorbance of the photocurable composition decreases rapidly over time, indicating that the photoinitiator system in the composition can undergo photolysis under near-infrared light source irradiation.

[0365] Example 15 - Mechanical property testing of products manufactured by SLA 3D printing

[0366] This embodiment illustrates that the products prepared by the 3D printing photocurable composition of the present invention have good mechanical properties.

[0367] S132 was selected as the infrared-absorbing photosensitizer, iodonium salt IS1 as the initiator, and acryloylmorpholine ACMO as the monomer. Using 220 and LuCure8091 as oligomers, sodium tetraphenylborate as a reducing agent, and triphenylphosphine as an arylphosphine compound, a photocurable composition was prepared (its formulation is the same as in Example 9), as shown in Table 29. A tensile rod was then fabricated using a near-infrared photocurable SLA 3D printer according to the printing parameters in Table 30. The overall length of the tensile rod was 55 mm, the overall width was 10.7 mm, the overall thickness was 2.5 mm, and the width at the fracture point was 2.8 mm. Post-curing was then performed using an 820 nm LED light source (light intensity 1.5 W / cm²). -2 The stress-strain test was then performed at 25°C using an Instron 5969 electromechanical universal testing machine for 30 minutes. The tensile rate was set to 15 mm / min.

[0368] Table 29: Formulations of Photocurable Compositions

[0369] Table 30: Exposure Conditions

[0370] The tensile bar prepared in Example 15 is shown in Figure 13(b). Three tensile bars with the same dimensions were printed simultaneously. The stress-strain curves of the tensile bars are shown in Figure 19, and the values ​​of tensile stress and tensile strain are shown in Table 31. The results show that the tensile bar prepared by SLA 3D printing has good mechanical properties, and the data among the three samples are not significantly different, with very similar slopes, indicating that SLA 3D printing has good printing stability.

[0371] Table 31: Tensile stress and tensile strain of tension bars

Claims

1. A photocurable composition comprising the following components: (a) at least one polymethyl benzoin compound, which serves as an infrared-absorbing photosensitizer; (b) at least one photopolymerization initiator; (c) at least one free radical photopolymerizable compound; (d) at least one electron-donating reducing agent; and (e) At least one arylphosphine compound.

2. The photocurable composition according to claim 1, wherein the polycyanine compound as the component (a) has a structure represented by formula (I): ###0001### (I) in Y + represents a bicyclic, tricyclic or more ring heterocycle with 8 to 18 ring members and containing 1 or 2 nitrogen atoms as ring members and carrying one positive charge, Y represents a heterocycle with 8-18 ring members and containing 1 or 2 nitrogen atoms as ring members, consisting of bicyclic, tricyclic, or more rings. Y + The heterocycles defined in Y may have one or more selected from halogens, CN, nitro, C1-C. 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups, C1-C 12 Branched or unbranched alkylthio or phenylthio substituents, wherein the C1-C 12 Branched or unbranched alkyl groups, the C1-C 12 Branched or unbranched alkoxy groups, the C1-C 12 The alkyl group in a branched or unbranched alkylthio group can be separated by one or more non-adjacent oxygen atoms; Preferably Y + Y are each structural units as shown below: indole salt / indole phenyl[e]indolium salts / phenyl[e]indoles and / or phenyl[c,d]indolium salts / phenyl[c,d]indoliums, wherein the benzene or naphthalene ring of the indolium salt / indole, phenyl[e]indolium salt / phenyl[e]indole and phenyl[c,d]indolium salt / phenyl[c,d]indole can carry one or more, preferably one or two, substituents selected from the group consisting of halogen, CN, nitro, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C 12 branched or unbranched alkyl, C1-C n branched or unbranched alkyl, C1-C The positions of the cyclic carbon indicated by the arrows are the connection sites with the polymethyl tannin chain; More preferably Y + Y is a structural unit as shown below: and / or R1is selected from the group consisting of C1-C 12 branched or unbranched alkyl and C1-C 12 branched or unbranched alkyl and C1-C 12 branched or unbranched alkyl and C1-C 12 branched or unbranched alkyl and C1-C n polyether of the formula shown, wherein n is 1-6 and R is H or CH3; and R2 and R3 are independently selected from H, halogen, CN, nitro, C1-C. 12 Branched or unbranched alkyl groups, C1-C 12 Branched or unbranched alkoxy groups, C1-C 12 Branched or unbranched alkylthio or phenylthio, wherein the C1-C 12 Branched or unbranched alkyl groups, the C1-C 12 Branched or unbranched alkoxy groups, the C1-C 12 The alkyl group in a branched or unbranched alkylthio group can be separated by one or more non-adjacent oxygen atoms; The positions of the cyclic carbon indicated by the arrows are the connection sites with the polymethyl tannin chain; n1 and n2 are independently 0, 1 or 2; preferably 0 or 1, more preferably 1; B and C are independently selected from H, C1-C 12 alkyl or together with the carbon atom to which they are attached form a five- or six-membered ring; A is selected from the structures depicted in A-1 through A-13: or C1-C 12 branched or unbranched alkoxy (A-13); in * indicates the connection point with the structure of equation (I). Wherein, the "R2 and R2" groups may be the same or different, and each is independently selected from hydrogen, halogen, C1-C6 branched or unbranched alkyl, C1-C6 branched or unbranched alkoxy, C1-C6 branched or unbranched alkylthio or phenylthio. Preferably, group A is selected from the structures shown in A-1, A-2, A-4, A-5 or A-7 to A-13; When group A is group A-1 or A-2, n3 is 0; when group A is one of groups A-3 to A-13, n3 is 1. and X - represents a counterion.

3. The photocurable composition according to claim 2, wherein the compound of formula (I) satisfies one or more of the following conditions: R1 is selected from C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy, wherein the C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy may be separated by one or two non-adjacent oxygen atoms. R2 is selected from H, halogen, nitro, C1-C6 branched or unbranched alkyl and C1-C6 branched or unbranched alkoxy, wherein the C1-C6 branched or unbranched alkyl and the C1-C6 branched or unbranched alkoxy may be separated by one or two non-adjacent oxygen atoms. R3 is selected from H, C1-C6 branched or unbranched alkyl groups and C1-C6 branched or unbranched alkoxy groups, wherein the C1-C6 branched or unbranched alkyl groups and the C1-C6 branched or unbranched alkoxy groups may be separated by one or two non-adjacent oxygen atoms.

4. The photocurable composition according to claim 2 or 3, wherein B and C are independently H or form a five- or six-membered ring together with the carbon atoms connecting them, preferably B and C form a five- or six-membered ring together with the carbon atoms connecting them.

5. A photocurable composition according to any one of items 2-4, wherein the "R2 and R2" groups are the same or different, and each is independently selected from hydrogen or C1-C6 branched or unbranched alkyl groups.

6. Photocurable composition according to any of claims 2 to 5, wherein X - represents the following counterion: BF4 - , [B(Ph4] - , PF6 - , SbF6 - , AsF6 - , [PF3(C2F5)3] - , [Al(OC(CF3)3)4] - , [B(PhF5)4] - , [B(Ph(CF3)2)4] - , [((CF3)2SO2)2N] - , [((CF3)2SO2)3C] - , Cl - , Br - , F - , [Al(O-t-C4F9)4] - , [Al(O-(i-C3F7)CH3)4] - , [C(O-SO2CF3)3] - , [n-C 12 H 25- TsO] - or [NTf2] - , wherein preferably BF4 - , [B(Ph4] - , PF6 - , SbF6 - , AsF6 - , [PF3(C2F5)3] - , [Al(OC(CF3)3)4] - , [B(PhF5)4] - , [B(Ph(CF3)2)4] - , [((CF3)2SO2)2N] - , [((CF3)2SO2)3C] - , [Al(O-t-C4F9)4] - , [Al(O-(i-C3F7)CH3)4] - or [NTf2] - .

7. The photocurable composition according to any one of claims 2-6, wherein the polymethyl benzoin compound as component (a) is selected from one or more of the following compounds S1-S189: When n=0, it is a quinary ring; when n=1, it is a hexagram. Wherein barb1 refers to the A-1 group as defined in claim 1, where both R2 and R2 are -CH3, and barb2 refers to the A-2 group as defined in claim 1, where both R2 and R2 are -CH3. Preferably, the polymethyl benzoic acid compound used as component (a) is selected from S132, S44 or a mixture thereof.

8. The photocurable composition according to any one of claims 1-7, wherein the photopolymerization initiator as component (b) is a photopolymerization initiator capable of generating free radicals in the presence of component (a).

9. The photocurable composition according to any one of claims 1-8, wherein the photopolymerization initiator as component (b) is selected from iodonium salts, thiodonium salts, triazines, and oxime ester photopolymerization initiators.

10. The photocurable composition according to any one of claims 1-9, wherein the photopolymerization initiator as component (b) is an iodonium salt, preferably selected from iodonium salts as shown in Formula II: in, R1'-R6' can be the same or different and are independently selected from H, halogen, nitro, C1-C 20 Branched or unbranched alkyl groups, C1-C 20 Branched or unbranched alkoxy groups and C1-C 20 Branched or unbranched alkylthio groups, and X' - As described in claim 2 or 6, X in compound (I) - Defined Preferably X in the compound of formula (I) - and X' in the compound of formula (II) - are the same.

11. The photocurable composition according to any one of claims 1-10, wherein the photopolymerization initiator as component (b) is selected from one or more of the following compounds IS1-IS41: Preferably, the photopolymerization initiator used as component (b) is selected from IS1, IS41 or a mixture thereof.

12. The photocurable composition according to any one of claims 1-11, wherein the weight ratio of the infrared absorbing photosensitizer as component (a) to the photopolymerization initiator as component (b) is 100:1-1:100, preferably 1:1-1:100, more preferably 1:10-1:

100.

13. The photocurable composition according to any one of claims 1-12, wherein the amount of the infrared absorbing photosensitizer as component (a) is 0.001-5% by weight, preferably 0.01-1% by weight, based on the total weight of the photocurable composition.

14. The photocurable composition according to any one of claims 1-13, wherein the amount of the photopolymerization initiator as component (b) is 0.01-10% by weight, preferably 0.1-5% by weight, based on the total weight of the photocurable composition.

15. The photocurable composition according to any one of claims 1-14, wherein the free radical photopolymerizable compound comprises at least one of a free radical polymerizable resin, a free radical polymerizable monomer with two or more functional groups, and a free radical polymerizable monomer with a single functional group, preferably the free radical photopolymerizable compound comprises a free radical polymerizable resin and a free radical polymerizable monomer with two or more functional groups, or the free radical photopolymerizable compound comprises a free radical polymerizable resin and a free radical polymerizable monomer with a single functional group, or the free radical photopolymerizable compound comprises a free radical polymerizable resin, a free radical polymerizable monomer with two or more functional groups, and a free radical polymerizable monomer with a single functional group.

16. The photocurable composition according to any one of claims 1-15, wherein the electron-donating reducing agent is selected from phenylglycine compounds and aryl borates, preferably selected from phenylglycine compounds and aryl borates, for example selected from sodium tetraphenylborate and N-phenylglycine.

17. The photocurable composition according to any one of claims 1-16, wherein the weight ratio of the electron-donating reducing agent to the photopolymerization initiator is 5:1-1:50, preferably 1:1-1:40, more preferably 1:2-1:

20.

18. The photocurable composition according to any one of claims 1-17, wherein the amount of the electron-donating reducing agent is 0.05-2% by weight, preferably 0.08-1.2% by weight, based on the total weight of the photocurable composition.

19. The photocurable composition according to any one of claims 1-18, wherein the arylphosphine compound is an arylphosphine compound having trivalent phosphorus atoms, especially triphenylphosphine.

20. The photocurable composition according to any one of claims 1-19, wherein the weight ratio of the arylphosphide compound to the photopolymerization initiator is 5:1-1:50, preferably 1:1-1:40, more preferably 1:2-1:

20.

21. The photocurable composition according to any one of claims 1-20, wherein the weight ratio of the electron-donating reducing agent to the arylphosphide compound is 10:1-1:10, preferably 5:1-1:5, more preferably 3:1-1:

3.

22. The photocurable composition according to any one of claims 1-21, wherein the amount of the arylphosphide compound is 0.05-2% by weight, preferably 0.08-1.2% by weight, based on the total weight of the photocurable composition.

23. The photocurable composition according to any one of claims 1-22, wherein the photocurable composition comprises at least one colorant, such as a dye and pigment, and in particular, the amount of the colorant is 0.05-20% by weight, preferably 0.08-10% by weight or 0.1-2% by weight, based on the total weight of the photocurable composition.

24. The use of the photocurable composition according to any one of claims 1-23 in 3D printing, especially SLA 3D printing, preferably using an NIR (laser) light source with an emission wavelength of 700-2000 nm, more preferably 750-900 nm, to process the photocurable composition.

25. A photocurable article obtained from a photocurable composition according to any one of claims 1-23.

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