Photoinitiator as well as preparation method and application thereof

Abstract

The invention provides a photoinitiator and a preparation method and application thereof, the photoinitiator has a structure as shown in a formula (I), when the photoinitiator is applied to a photocuring system, the photoinitiator is good in compatibility, high in initiation activity, free of migration and high in atom utilization rate, and the photoinitiator can be applied to a hybrid system.

Description

Technical Field

[0001] This invention belongs to the field of organic chemistry, specifically relating to a photoinitiator, its preparation method, and its application. Background Technology

[0002] Benzoate esters and their derivatives possess the characteristic of intramolecular ring closure and self-hydrogen donation, enabling polymerization to be initiated without the addition of amine hydrogen donors. Their use as photoinitiators has been widely reported (e.g., CN1649905A, CN101523289A, US4229274A). With the development of photoinitiator systems, disubstituted benzoate ester initiators with different parent groups have been developed (e.g., CN101175773A, CN109790137A, CN102640055A, etc.), which have improved the initiation efficiency of these products to a certain extent, reduced migration, and met the application requirements.

[0003] However, improving the initiation efficiency of photoinitiators has always been a goal. In addition, how to improve the solubility and migration of initiator products after curing without affecting the initiation efficiency is also a direction that needs further breakthroughs. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a photoinitiator, its preparation method and application. Compared with traditional benzoic acid ester initiators, the initiator of this invention has good compatibility, high initiation activity and no migration when applied to photocuring systems, high atom utilization, and can be applied to hybrid systems.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] On one hand, the present invention provides a photoinitiator having a structure as shown in formula (I):

[0007]

[0008] in,

[0009] X is an O, S, or direct bond;

[0010] Y is O, S, or CR9R 10 ;

[0011] R1, R2, R3, R4, R5, R6, R7, and R8 are independently hydrogen, halogen, hydroxyl, or C1-C. 18 Alkyl, C5-C 10 cycloalkyl, C2-C 18Alkenyl, phenyl, C1-C4 alkoxy, C5-C7 cycloalkoxy, phenoxy, C1-C4 alkylthio, C5-C7 cycloalkylthio, phenylthio, di(C1-C4 alkyl)amino, di(C5-C7 cycloalkyl)amino, N-morpholinyl, N-piperidinyl n is 1 or 2, q is 0 or 1, m is an integer from 1 to 4, R is H, methyl or ethyl, A is a direct bond or a C1-C6 straight-chain or branched alkyl group, and X is a C1-C6 bond. 10 Straight-chain or branched alkyl groups, or C1-C 10 A group in which at least one CH2 group of a straight-chain or branched alkyl group is discontinuously replaced by an oxygen or carbonyl group, where R' is H, a C1-C6 straight-chain or branched alkyl group, a phenyl group, or a cycloalkyl group substituted with a C1-C6 straight-chain or branched alkyl group, and at least one of R1, R2, R3, R4, R5, R6, R7, and R8 has an n of 1 and a q of 1. Group;

[0012] R9 and R 10 Independently hydrogen, C1-C 18 Alkyl, C2-C 12 alkenyl, C5-C 10 Cycloalkyl, phenyl, C1-C4 alkylphenyl, R9 and R 10 They exist independently or together with the C atoms they are attached to form 5-membered, 6-membered, or 7-membered rings.

[0013] Preferably, the CR9R 10 Selected from -CH2- The wavy lines represent the connection sites of the functional groups.

[0014] Preferably, the Selected from

[0015] Preferably, R1, R2, R3, R4, R5, R6, R7, and R8 are selected independently from hydrogen, F, Cl, hydroxyl, methyl, ethyl, n-propyl, isopropyl, CH3-S-, ... methoxy

[0016] Or the above Group.

[0017] For non-restrictive purposes, equation (I) may have the following structure:

[0018]

[0019]

[0020]

[0021]

[0022] On the other hand, the present invention provides a method for preparing the photoinitiator as described above, the method comprising the following steps:

[0023] (1) The arylformyl ester shown in Formula III undergoes a hydrolysis reaction to give the arylformyl carboxylic acid shown in Formula II, as shown in the following reaction formula:

[0024]

[0025] (2) The arylformoylformic acid shown in Formula II reacts with the epoxy compound shown in Formula IV to obtain the photoinitiator shown in Formula I, as shown in the following reaction formula:

[0026]

[0027] Among them, at least one of R1”, R2”, R3”, R4”, R5”, R6”, R7” and R8” is selected from Other groups, independently of each other, are hydrogen, halogen, hydroxyl, C1-C18 alkyl, C5-C10 cycloalkyl, C2-C18 alkenyl, phenyl, C1-C4 alkoxy, C5-C7 cycloalkoxy, phenoxy, C1-C4 alkylthio, C5-C7 cycloalkylthio, phenylthio, di(C1-C4 alkyl)amino, di(C5-C7 cycloalkyl)amino, N-morpholinyl, N-piperidinyl, n is 1 or 2, q is 0 or 1, m is an integer from 1 to 4, R is H, methyl or ethyl, X is a C1-C10 straight-chain or branched alkyl group, or a group in which at least one CH2 group of a C1-C10 straight-chain or branched alkyl group is replaced by oxygen or carbonyl in a discontinuous manner, R' is H, a C1-C6 straight-chain or branched alkyl group, a phenyl group, or a cycloalkyl group substituted with a C1-C6 straight-chain or branched alkyl group; at least one of R1', R2', R3', R4', R5', R6', R7', and R8' is selected from... Other groups, independently of each other, are hydrogen, halogen, hydroxyl, C1-C18 alkyl, C5-C10 cycloalkyl, C2-C18 alkenyl, phenyl, C1-C4 alkoxy, C5-C7 cycloalkoxy, phenoxy, C1-C4 alkylthio, C5-C7 cycloalkylthio, phenylthio, di(C1-C4 alkyl)amino, di(C5-C7 cycloalkyl)amino, N-morpholinyl, N-piperidinyl, n is 1 or 2, q is 0 or 1, m is an integer from 1 to 4, R is H, methyl or ethyl, X is a C1-C10 straight-chain or branched alkyl group, or a group in which at least one CH2 group of a C1-C10 straight-chain or branched alkyl group is replaced by oxygen or carbonyl in a discontinuous manner, and R' is H, C1-C6 straight-chain or branched alkyl group, phenyl or cycloalkyl substituted C1-C6 straight-chain or branched alkyl group.

[0028] In this invention, different arylformyl esters are hydrolyzed to obtain arylformylformic acid, which is then further esterified with an epoxy compound to obtain the target product.

[0029] Preferably, the hydrolysis reaction in step (1) is carried out in the presence of an acidic catalyst.

[0030] Preferably, the acidic catalyst is selected from any one or a combination of at least two of concentrated sulfuric acid, polyphosphoric acid, hydrochloric acid, hydrobromic acid, phosphorus oxychloride, phosphorus pentachloride, dodecylbenzene sulfonic acid, p-toluene sulfonic acid, or strong acid resin.

[0031] Preferably, the amount of acidic catalyst added is 5%-15% of the weight of the arylformyl ester of Formula III, for example 5%, 7%, 9%, 10%, 12%, 14% or 15%.

[0032] Preferably, the solvent for the hydrolysis reaction in step (1) is water.

[0033] Preferably, the temperature of the hydrolysis reaction in step (1) is 90-100℃, for example 90℃, 93℃, 95℃, 98℃ or 100℃, and the reaction time is 10-24h, for example 10h, 12h, 15h, 18h, 20h, 22h or 24h.

[0034] Preferably, the molar ratio of the arylformic acid shown in Formula II to the epoxy compound shown in Formula IV in step (2) is 1.0:2.5.

[0035] In this invention, the reaction in step (2) may or may not be solvent-free. There is no particular limitation on the type of solvent used, as long as it can dissolve the reaction raw materials and has no adverse effect on the reaction. Preferably, the solvent in the reaction in step (2) is selected from any one or at least a combination of two of benzene, toluene, xylene or N,N-dimethylformamide.

[0036] Preferably, the reaction temperature in step (2) is 60-150℃, for example 60℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃ or 150℃, and the reaction time is 2-8h, for example 2h, 3h, 4h, 5h, 6h, 7h or 8h.

[0037] On the other hand, the present invention provides a photosensitive resin composition comprising the photoinitiator as described above.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The photoinitiator of the present invention has excellent solubility, and can be applied not only to free radical systems, but also to mixed systems, and does not migrate after application. Detailed Implementation

[0040] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0041] Preparation Examples

[0042] Example 1

[0043] This embodiment provides a method for preparing compound (Ⅰ), and the reaction process for its preparation is shown below:

[0044] The specific steps include:

[0045] Add 53.6g of raw material 1(a) to a 2L four-necked flask, dissolve it in 600g of distilled water, and heat it in a water bath at a temperature above 95°C. Then, add 3g of macroporous strong acid resin catalyst while stirring, and react continuously for 10h. Cool the reaction system in an ice-water bath and filter to obtain 43.5g of crystalline product 1(b), with a yield of 87%.

[0046] Add 50g of 1(b) above, 600mL of toluene, and 3g of macroporous strong acid resin catalyst to a 2L four-necked reaction flask, and heat to 60℃. Add 29g of 1(c) dropwise and react for 3.5h to obtain a reaction solution. Continue to heat and reflux to distill off the toluene. Add the reaction solution to 200mL of pure water, and a solid precipitates. Stir and wash at 60℃ for 30min, filter to obtain a wet filter cake, and dry at 150mbar and 60℃ to obtain a pale yellow solid (Ⅰ). HPLC analysis shows a purity of 99.8% and a yield of 85%.

[0047] Characterization data:

[0048] 1¹H NMR (500MHz, deuterated chloroform) δ 7.61 (dd, J = 7.5, 1.5Hz, 1H), 7.52 (d, J = 1.5Hz, 1H), 7.27 (td, J = 7.5, 1.5Hz, 1H), 7.26–7.18 (m, 2H), 6.93 (td, J = 7.5, 1.6Hz, 1H), 6.57 (dd, J = 7.5, 1.6Hz, 1H), 4.20–4.11 (m, 6H), 4.00 (d, J = 12.3Hz, 2H), 1.66 (q, J = 8.0Hz, 2H), 0.85 (t, J = 8.0Hz, 3H).

[0049] Example 2

[0050] This embodiment provides a method for preparing compound (II), and the reaction process for its preparation is shown below:

[0051]

[0052] The specific steps include:

[0053] 74 g of raw material 2(a) was added to a 2 L four-necked flask and dissolved in 800 g of distilled water. The mixture was heated in a water bath at a temperature above 95 °C. Then, 5 g of macroporous strong acid resin catalyst was added with stirring, and the reaction was continued for 10 h. The reaction system was then cooled in an ice-water bath and filtered to obtain 60 g of crystalline product 2(b), with a yield of 89%.

[0054] Add 43g of 2(b), 800mL of toluene, and 3.4g of macroporous strong acid resin catalyst to a 2L four-necked reaction flask, and heat to 60℃. Add 51g of 2(c) dropwise, and the reaction is completed after 3.5h. The reaction solution is obtained, and the temperature is further increased to reflux. Toluene is distilled off, and the reaction solution is added to 200mL of pure water. A solid precipitates out. The solid is stirred and washed at 60℃ for 30min, filtered to obtain a wet filter cake, and dried at 150mbar and 60℃ to obtain 78g of pale yellow solid (II). The purity was determined by HPLC to be 99.5%, and the yield was 87%.

[0055] Characterization data:

[0056] 1¹H NMR (500MHz, deuterated chloroform) δ 7.99 (dd, J = 4.6, 3.2Hz, 4H), 7.83 (dd, J = 7.5, 1.4Hz, 2H), 5.62 (dddd, J = 7.0, 5.9, 2.2, 1.2Hz, 1H), 5.01 (p, J = 7.0Hz, 1H), 4.35 (dd, J = 12.4, 6.8Hz, 1H), 4.29–4.21 (m, 1H), 4.04 (d, J = 12.5Hz, 4H), 3.75–3. 64(m,8H),3.66–3.59(m,2H),3.63–3.56(m,2H),3.50(d,J=12.5Hz,2H),3.30–3.21(m,1H),2.02–1.82(m,2H), 1.74(dq,J=12.3,8.0Hz,2H), 1.57(dq,J=12.5,8.0Hz,2H), 1.00(td,J=8.0,1.5Hz,3H), 0.86(t,J=8.0Hz,6H).

[0057] Example 3

[0058] This embodiment provides a method for preparing compound (Ⅲ), and the reaction process for its preparation is shown below:

[0059]

[0060] 73.2 g of raw material 3(a) was added to a 2 L four-necked flask and dissolved in 800 g of distilled water. The mixture was heated in a water bath at 95 °C. Then, 5.12 g of macroporous strong acid resin catalyst was added with stirring, and the reaction was continued for 10 h. The reaction system was cooled in an ice-water bath and filtered to obtain 60.84 g of crystalline intermediate product 3(b), with a yield of 90%.

[0061] Add 60g of 3(b), 800mL of toluene, and 4.3g of macroporous strong acid resin catalyst to a 2L four-necked reaction flask, and heat to 60℃. Add 18.5g of 3(c) dropwise, and the reaction is completed after 3.5h to obtain the reaction solution. Continue to heat and reflux, and distill off the toluene to obtain 65.5g of intermediate product 3(e), with a yield of 83%.

[0062] Add 60g of 3(e), 600mL of toluene, and 3g of macroporous strong acid resin catalyst to a 2L four-necked reaction flask, and heat to 60℃. Add 55g of 3(f) dropwise, and the reaction is completed after 3.5h, yielding a reaction solution. Continue heating and reflux to distill off the toluene. Add the reaction solution to 200mL of pure water, and a solid precipitates. Stir and wash at 60℃ for 30min, filter to obtain a wet filter cake, and dry at 150mbar and 60℃ to obtain a pale yellow solid (Ⅲ). HPLC analysis shows a purity of 99.3% and a yield of 85%.

[0063] Characterization data:

[0064] 1 ¹H NMR (500MHz, deuterated chloroform) 7.99 (dd, J = 4.6, 3.2Hz, 4H), 7.83 (dd, J = 7.5, 1.4Hz, 2H), 5.62 (dddd, J = 7.0, 5.9, 2.2, 1.2Hz, 1H), 5.01 (p, J = 7.0Hz, 1H), 4.35 (dd, J = 12.4, 6.8Hz, 1H), 4.29–4.21 (m, 1H), 4.04 (d, J = 12.5Hz, 4H), 3.75–3. 64(m,8H),3.66–3.59(m,2H),3.63–3.56(m,2H),3.50(d,J=12.5Hz,2H),3.30–3.21(m,1H),2.02–1.82(m,2H), 1.74(dq,J=12.3,8.0Hz,2H), 1.57(dq,J=12.5,8.0Hz,2H), 1.00(td,J=8.0,1.5Hz,3H), 0.86(t,J=8.0Hz,6H).

[0065] Examples 4-9

[0066] Products 4-9 having the structures shown in Table 1 below were synthesized according to the methods of Examples 1-3.

[0067] Table 1

[0068]

[0069]

[0070]

[0071]

[0072] Performance Evaluation

[0073] The application performance of the initiator of the present invention was evaluated by formulating exemplary photocurable compositions (i.e., photosensitive resin compositions, parts by weight).

[0074] Table 2-1 Free Radical System Photocurable Compositions

[0075]

[0076]

[0077] Table 2-2 Free Radical System Photocurable Compositions

[0078]

[0079] Table 3-1 Hybrid System Photocurable Compositions

[0080]

[0081]

[0082] Table 3-2 Hybrid System Photocurable Compositions

[0083]

[0084] Among them: E201: Bisphenol A epoxy acrylate (Changzhou Qiangli Electronic New Materials Co., Ltd.)

[0085] ACMO: Acryloylmorpholine (Runao Chemical)

[0086] TMPTA: Trimethylolpropane triacrylate

[0087] PEGDA: Polyethylene glycol diacrylate

[0088] BYK307: Leveling agent (BYK Chemicals, Germany)

[0089] PAG30201: Bis(4-tert-butylphenyl)iodonium hexafluorophosphate (Changzhou Qiangli Electronic New Materials Co., Ltd.)

[0090] PSS306: sensitizer (Changzhou Qiangli Electronic New Materials Co., Ltd.)

[0091] 2. Performance Evaluation Methods

[0092] (1) Solubility evaluation

[0093] The solubility of initiator A: [4-(4-methoxyoxalyl-phenylthioalkyl)-phenyl]-oxo-acetic acid methyl ester (IGM), initiator B: 2-(9,9-dimethoxyxanthan-2-yl)-2-oxo-acetic acid ethyl ester (IGM), and photoinitiator (Ⅰ)-(Ⅺ) provided in Examples 1-11 in propylene glycol methyl ether acetate were tested respectively, and the results are shown in Table 1 below.

[0094] The solubility test method is as follows: At room temperature (20±0.5℃), add an appropriate amount of 6110:TMPTA = 1:1 (mass ratio) photocurable monomer as a solvent to a 250mL glass beaker. Add 0.5g of the test sample to the solvent and stir for 20min. Visually observe whether there is any undissolved sample. If it dissolves completely, continue to add 0.5g of the test sample and stir for 20min until there is insoluble matter. Stop adding the sample, record the data, and calculate the sample solubility according to the following formula:

[0095]

[0096] Table 2

[0097]

[0098]

[0099] (2) Photosensitive evaluation

[0100] The photocurable composition was stirred and mixed under a yellow light lamp, and then rolled onto a PET template to form a film with a thickness of approximately 50 μm. The film was then heated by a mercury lamp (100%, 1 m / min, 1140 mJ / cm²). 2 ), LED385nm (100%, 3m / min, 2568mJ / cm 2 ), LED405nm (100%, 3m / min, 2568mJ / cm 2 Expose the mixture separately and observe its curing process. Evaluate the results according to the following criteria:

[0101] 1. Oil, not solid

[0102] 2. Surface oil, base layer cured.

[0103] 3. The surface is sticky, and fingerprints are easily left on the skin after touching it.

[0104] 4. Basically dry, slightly rough to the touch, faint fingerprints.

[0105] 5. Fully cured, smooth surface, no fingerprints after touching.

[0106] The test results are shown in Tables 4 and 5:

[0107] Table 4. Test results of the free radical system

[0108]

[0109] Table 5. Test results of the hybrid system

[0110]

[0111] (3) Transferability Testing

[0112] Using ethanol as a solvent, initiator (Ⅰ)-(Ⅺ), initiator (1), and initiator (2) were prepared into 1×10⁻⁶ solutions respectively. -5 The maximum absorption wavelength and absorbance A1 of the mol / L solution were measured using a UV3010 ultraviolet spectrophotometer, and the molar extinction coefficient was calculated using formula (1):

[0113] c = A / ε × b (1)

[0114] R = 100 × c / c1 (2)

[0115] Using the formulations of Evaluation Example 1 and Comparative Example 1 in Tables 3-1 and 3-2, the photocurable compositions were fully cured. 0.05g of the above photocurable compositions were weighed and fully cured under a high-pressure mercury lamp to obtain cured films. Each film was immersed in 30g of ethanol and left at room temperature for 24h. The absorbance A2 at the maximum absorption wavelength was measured using an ultraviolet spectrophotometer with the same volume of the immersion solution. The concentration of the photoinitiator migrating from the three cured films was calculated using formula (1). Using the concentration value of photoinitiator (1) as a reference, the relative migration rate of each photoinitiator was calculated using formula (2).

[0116] In the above formula, c is the relative concentration (mol / L), c1 is the relative concentration of photoinitiator (1), A is the absorbance, ε is the molar absorptivity (L / mol·cm), b is the sample cell thickness (cm), and R is the relative mobility. The test results are shown in Table 6.

[0117] Table 6

[0118]

[0119] Experiments show that the initiator of the present invention can be applied not only to free radical systems but also to hybrid systems, and has the effect of a long-wavelength initiator and low migration characteristics.

[0120] The applicant declares that the above embodiments illustrate the photoinitiator, its preparation method, and its application, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A photoinitiator, characterized in that, The photoinitiator has the structure shown in formula (I): in, X is an O, S, or direct bond; Y is O, S, or CR9R 10 ; R1, R2, R3, R4, R5, R6, R7, and R8 are independently hydrogen, halogen, hydroxyl, or C1-C. 18 Alkyl, C5-C 10 cycloalkyl, C2-C 18 Alkenyl, phenyl, C1-C4 alkoxy, C5-C7 cycloalkoxy, phenoxy, C1-C4 alkylthio, C5-C7 cycloalkylthio, phenylthio, di(C1-C4 alkyl)amino, di(C5-C7 cycloalkyl)amino, N-morpholinyl, N-piperidinyl n is 1 or 2, q is 0 or 1, m is an integer from 1 to 4, R is H, methyl or ethyl, A is a direct bond or a C1-C6 straight-chain or branched alkyl group, and X is a C1-C6 bond. 10 Straight-chain or branched alkyl groups, or C1-C 10 A group in which at least one CH2 group of a straight-chain or branched alkyl group is discontinuously replaced by an oxygen or carbonyl group, where R' is H, a C1-C6 straight-chain or branched alkyl group, a phenyl group, or a cycloalkyl group substituted with a C1-C6 straight-chain or branched alkyl group, and at least one of R1, R2, R3, R4, R5, R6, R7, and R8 has an n of 1 and a q of 1. Group; R9 and R 10 Independently hydrogen, C1-C 18 Alkyl, C2-C 12 alkenyl, C5-C 10 Cycloalkyl, phenyl, C1-C4 alkylphenyl, R9 and R 10 They exist independently or together with the C atoms they are attached to form 5-membered, 6-membered, or 7-membered rings.

2. The photoinitiator according to claim 1, characterized in that, The CR9R 10 Selected from -CH2- The wavy lines represent the connection sites of the functional groups.

3. The photoinitiator according to claim 1 or 2, characterized in that, The Selected from 4. The photoinitiator according to any one of claims 1-3, characterized in that, R1, R2, R3, R4, R5, R6, R7, and R8 are selected from those independently selected from hydrogen, F, Cl, hydroxyl, methyl, ethyl, n-propyl, isopropyl, CH3-S-, ... methoxy Or the above Group.

5. The photoinitiator according to any one of claims 1-4, characterized in that, The photoinitiator is any one of the following compounds:

6. The method for preparing the photoinitiator according to any one of claims 1-5, characterized in that, The preparation method includes the following steps: (1) The arylformyl ester shown in Formula III undergoes a hydrolysis reaction to give the arylformyl carboxylic acid shown in Formula II, as shown in the following reaction formula: (2) The arylformoylformic acid shown in Formula II reacts with the epoxy compound shown in Formula IV to obtain the photoinitiator shown in Formula I, as shown in the following reaction formula: Among them, at least one of R1”, R2”, R3”, R4”, R5”, R6”, R7” and R8” is selected from Other groups, independently of each other, are hydrogen, halogen, hydroxyl, C1-C18 alkyl, C5-C10 cycloalkyl, C2-C18 alkenyl, phenyl, C1-C4 alkoxy, C5-C7 cycloalkoxy, phenoxy, C1-C4 alkylthio, C5-C7 cycloalkylthio, phenylthio, di(C1-C4 alkyl)amino, di(C5-C7 cycloalkyl)amino, N-morpholinyl, N-piperidinyl, n is 1 or 2, q is 0 or 1, m is an integer from 1 to 4, R is H, methyl or ethyl, A is a direct bond or a C1-C6 straight-chain or branched alkyl group, X is a C1-C10 straight-chain or branched alkyl group, or a group in which at least one CH2 group of a C1-C10 straight-chain or branched alkyl group is discontinuously replaced by an oxygen or carbonyl group, R' is a C1-C6 straight-chain or branched alkyl group substituted with H, C1-C6 straight-chain or branched alkyl group, phenyl group, or cycloalkyl group; at least one of R1', R2', R3', R4', R5', R6', R7', and R8' is selected from... Other groups, independently of each other, are hydrogen, halogen, hydroxyl, C1-C18 alkyl, C5-C10 cycloalkyl, C2-C18 alkenyl, phenyl, C1-C4 alkoxy, C5-C7 cycloalkoxy, phenoxy, C1-C4 alkylthio, C5-C7 cycloalkylthio, phenylthio, di(C1-C4 alkyl)amino, di(C5-C7 cycloalkyl)amino, N-morpholinyl, N-piperidinyl, n is 1 or 2, q is 0 or 1, m is an integer from 1 to 4, R is H, methyl or ethyl, A is a direct bond or a C1-C6 straight-chain or branched alkyl group, X is a C1-C10 straight-chain or branched alkyl group, or a group in which at least one CH2 group in a C1-C10 straight-chain or branched alkyl group is replaced by oxygen or carbonyl in a discontinuous manner, and R' is a C1-C6 straight-chain or branched alkyl group substituted with H, C1-C6 straight-chain or branched alkyl group, phenyl group or cycloalkyl group.

7. The preparation method according to claim 6, characterized in that, The hydrolysis reaction described in step (1) is carried out in the presence of an acidic catalyst; Preferably, the acidic catalyst is selected from any one or a combination of at least two of concentrated sulfuric acid, polyphosphoric acid, hydrochloric acid, hydrobromic acid, phosphorus oxychloride, phosphorus pentachloride, dodecylbenzene sulfonic acid, p-toluene sulfonic acid, or strong acid resin. Preferably, the amount of acidic catalyst added is 5%-15% of the weight of the arylformyl ester shown in Formula III; Preferably, the solvent for the hydrolysis reaction in step (1) is water; Preferably, the hydrolysis reaction in step (1) is carried out at a temperature of 90-100℃ and for a reaction time of 10-24h.

8. The preparation method according to claim 6 or 7, characterized in that, The molar ratio of the arylformoylformic acid shown in Formula II to the epoxy compound shown in Formula IV in step (2) is 1.0:2.0 to 2.

8.

9. The preparation method according to any one of claims 6-8, characterized in that, The solvent for the reaction in step (2) is selected from any one or a combination of at least two of benzene, toluene, xylene or N,N-dimethylformamide; Preferably, the reaction temperature in step (2) is 60-150℃ and the reaction time is 2-8h.

10. A photosensitive resin composition, characterized in that, The photosensitive resin composition includes the photoinitiator as described in any one of claims 1-5.

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