Carboxylic acid, acyl chloride compound, compound containing carbazole group, and oxime ester-based photoinitiator, photocurable coating, and cured film

Abstract

The application provides a carboxylic acid, an acyl chloride compound, a compound containing a carbazole group, an oxime ester photoinitiator, a photocuring coating and a cured film. The carboxylic acid compound has the general structure of: the acyl chloride compound has the general structure of: the oxime ester photoinitiator containing the carbazole group has the general structure of: the raw material of the photocuring coating comprises the oxime ester photoinitiator containing the carbazole group. The cured film is prepared by using the photocuring coating. The oxime ester photoinitiator containing the carbazole group provided by the application has good curing effect and low migration rate.

Description

Technical Field

[0001] This application relates to the field of photoinitiators, and more particularly to a carboxylic acid, acyl chloride compound, carbazole-containing compound and oxime ester photoinitiator, photocurable coating and cured film. Background Technology

[0002] Oxime esters are well-known as photoinitiators in this field due to their outstanding reactivity, and are widely used in high-end photoresists such as color filter films (RGB), black matrix (BM), photospacers, and ribs. Commonly used oxime ester photoinitiators are based on carbazole groups; however, their solubility with the matrix resin is often insufficient, resulting in insufficient hardness and high migration rates in the cured film.

[0003] Moreover, existing initiators require a large dosage when used.

[0004] Therefore, developing an oxime ester photoinitiator that has good compatibility with the matrix resin and produces a cured film with high hardness and low migration has become an urgent problem to be solved.

[0005] The preparation of intermediates is also essential for developing the aforementioned photoinitiators. Summary of the Invention

[0006] The purpose of this application is to provide a carboxylic acid, acyl chloride compound, carbazole-containing compound and oxime ester photoinitiator, photocurable coating and cured film to solve the above problems.

[0007] To achieve the above objectives, this application adopts the following technical solution:

[0008] A carboxylic acid compound with the following general structural formula:

[0009]

[0010] R1-R5 are selected from H, C1-C20 straight-chain alkyl, C1-C20 branched alkyl, and C3-C20 cycloalkyl; and at least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

[0011] This application also provides an acyl chloride compound with the following general structural formula:

[0012]

[0013] R1-R5 are selected from H, C1-C20 straight-chain alkyl, C1-C20 branched alkyl, and C3-C20 cycloalkyl, and at least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

[0014] This application also provides a compound containing a carbazole group, the general structural formula of which is:

[0015]

[0016] Among them, R1-R5 are selected from H, straight-chain alkyl groups of C1-C20, branched alkyl groups of C1-C20, and cycloalkyl groups of C3-C20;

[0017] R 21 Selected from C1-C20 straight-chain alkyl, C1-C20 branched-chain alkyl, C3-C20 cycloalkyl, and C6-C20 aryl.

[0018] This application also provides a compound containing a carbazole group, the raw materials for which the carbazole group-containing compound is described above, and its general structural formula is:

[0019]

[0020] Among them, R1-R5 are selected from H, straight-chain alkyl groups of C1-C20, branched alkyl groups of C1-C20, and cycloalkyl groups of C3-C20;

[0021] R 21 Selected from C1-C20 straight-chain alkyl, C1-C20 branched-chain alkyl, C3-C20 cycloalkyl, and C6-C20 aryl;

[0022] R 31 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, and C3-C20 cycloalkyl-substituted C1-C20 branched alkyl.

[0023] The compounds containing the carbazole group mentioned above include compounds of the following two general formulas:

[0024]

[0025] Furthermore, in In this composition, at least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, or 1-methylcyclohexyl.

[0026] This application also provides a compound containing a carbazole group, the raw materials for which the carbazole group-containing compound is described above, and its general structural formula is:

[0027]

[0028] Among them, R1-R5 are selected from H, straight-chain alkyl groups of C1-C20, branched alkyl groups of C1-C20, and cycloalkyl groups of C3-C20;

[0029] R 21 Selected from C1-C20 straight-chain alkyl, C1-C20 branched-chain alkyl, C3-C20 cycloalkyl, and C6-C20 aryl;

[0030] R 31 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, and C3-C20 cycloalkyl-substituted C1-C20 branched alkyl.

[0031] The compounds containing the carbazole group mentioned above include the following two compounds represented by the general formula:

[0032]

[0033] Furthermore, in In this composition, at least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, or 1-methylcyclohexyl.

[0034] This application also provides an oxime ester photoinitiator containing a carbazole group, with the following general structural formula:

[0035]

[0036] Among them, R1-R5 are selected from H, straight-chain alkyl groups of C1-C20, branched alkyl groups of C1-C20, and cycloalkyl groups of C3-C20;

[0037] R 21 Selected from C1-C20 straight-chain alkyl, C1-C20 branched-chain alkyl, C3-C20 cycloalkyl, and C6-C20 aryl;

[0038] R 31 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, and C3-C20 cycloalkyl-substituted C1-C20 branched alkyl.

[0039] R 41 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, 3-C20 cycloalkyl-substituted C1-C20 branched alkyl, and C6-C20 aryl.

[0040] Preferably, the general structural formula of the carbazole-containing oxime ester photoinitiator is:

[0041]

[0042] Among them, at least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

[0043] The reaction equation for synthesizing this photoinitiator is as follows:

[0044]

[0045]

[0046] Preferably, at least two of R1, R3, and R5 are selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

[0047] Preferably, R1 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

[0048] Preferably, R 21 Selected from methyl, ethyl, propyl, butyl, pentyl, and hexyl;

[0049] R 31 R 41 Each is independently selected from C1-C20 straight-chain alkyl groups substituted with methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl.

[0050] Preferably, the general structural formula of the carbazole-containing oxime ester photoinitiator is:

[0051]

[0052] Preferably, R1 is selected from H, methyl, tert-butyl, R 21 Selected from methyl, ethyl, propyl, butyl, pentyl, and hexyl;

[0053] Preferably, R 31 R 41 Each is independently selected from C1-C20 straight-chain alkyl groups substituted with methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl.

[0054] The reaction equation for this photoinitiator is:

[0055]

[0056]

[0057] This application also provides a photocurable coating, the raw materials of which include the aforementioned oxime ester photoinitiator containing a carbazole group;

[0058] Preferably, the photocurable coating further includes copolymers, monomers, solvents, and additives;

[0059] Preferably, the raw materials of the photocurable coating include a variety of the aforementioned oxime photoinitiators containing carbazole groups;

[0060] Preferably, the raw materials of the photocurable coating include two of the aforementioned carbazole-containing oxime ester photoinitiators.

[0061] This application also provides a cured film prepared using the aforementioned photocurable coating.

[0062] Compared with the prior art, the beneficial effects of this application include:

[0063] The carboxylic acid compounds, acyl chloride compounds, and compounds containing carbazole groups provided in this application provide a raw material basis for the development of oxime ester photoinitiators containing carbazole groups.

[0064] The oxime ester photoinitiator containing a carbazole group provided in this application has good curing effect and low migration rate of the cured film.

[0065] When the carbazole-containing oxime ester photoinitiator of this application has the following structure:

[0066]

[0067] At least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl. Because tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl have large steric hindrance, the carbonyl group on the left side of the above structure is more likely to crack and generate free radicals, which improves the curing efficiency. As a result, the hardness of the cured film increases and the migration rate decreases after curing.

[0068] When the carbazole-containing oxime ester photoinitiator of this application has the following structure:

[0069]

[0070] The carbonyl group on the left is located at position 4 of the carbazole ring. Compared with the carbonyl group on the left being located at position 3 of the carbazole ring, the carbonyl group on the left is more prone to cleavage and generate free radicals, which improves the curing efficiency. As a result, the hardness of the cured film increases and the migration rate decreases after curing.

[0071] The photocurable coating provided in this application has a good curing effect, and the cured film prepared has high hardness and low migration rate. Attached Figure Description

[0072] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0073] Figure 1The HPLC chromatogram of compound P1 is shown below.

[0074] Figure 2 This is the HPLC chromatogram of compound S1. Detailed Implementation

[0075] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0076] Examples 1-20

[0077] The preparation of carboxylic acid compounds and acyl chloride compounds will be explained first, as follows:

[0078] The general structural formula of carboxylic acid compounds is:

[0079]

[0080] R1-R5 are selected from H, C1-C20 straight-chain alkyl, C1-C20 branched alkyl, and C3-C20 cycloalkyl; and at least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

[0081] The general structural formula of the acyl chloride compound is:

[0082]

[0083] R1-R5 are selected from H, C1-C20 straight-chain alkyl, C1-C20 branched alkyl, and C3-C20 cycloalkyl, and at least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

[0084] Exemplary:

[0085] Preparation Example 1

[0086] The synthesis of 4-(1-methylcyclopentyl)benzoyl chloride is shown in the following reaction equation:

[0087]

[0088] First, 4-(1-methylcyclopentyl)benzoic acid was synthesized:

[0089] Under nitrogen protection, 5.0 g of 4-(1-methylcyclopentyl)bromobenzene and 80 mL of tetrahydrofuran were added to a 250 mL three-necked flask. The mixture was cooled to -78 °C, and 15.6 mL of a 1.6 M butyllithium solution in n-hexane was slowly added dropwise. After the addition was complete, the mixture was kept at -78 to -60 °C for half an hour. Then, dry carbon dioxide gas was slowly introduced, controlling the temperature not to exceed -40 °C, until the reaction system no longer absorbed carbon dioxide, and then the gas was introduced for another half hour. The mixture was slowly raised to room temperature, and the reaction was allowed to proceed for 2 hours. The reaction solution was poured into ice water to obtain a solid. The solid was collected, dried, and crystallized from methanol to give 3.2 g of 4-(1-methylcyclopentyl)benzoic acid.

[0090] Infrared measurements revealed a characteristic peak for carboxyl groups at 1700–1750 nm.

[0091] Then, 4-(1-methylcyclopentyl)benzoyl chloride was synthesized:

[0092] In a 1000 mL three-necked flask, add 21 g of 4-(1-methylcyclopentyl)benzoic acid and 200 mL of dichloromethane. Slowly add 20 g of thionyl chloride. After the addition is complete, slowly heat to reflux and react for half an hour. Cool down and slowly add isopropanol to decompose the excess thionyl chloride. Then concentrate the reaction solution to dryness and then distill under reduced pressure to obtain 16.8 g of 4-(1-methylcyclopentyl)benzoyl chloride.

[0093] Preparation Example 2

[0094] The synthesis of 2-(1-methylcyclopentyl)benzoyl chloride is shown in the following reaction equation:

[0095]

[0096] Following the synthesis of 4-(1-methylcyclopentyl)benzoyl chloride, 2-(1-methylcyclopentyl)benzoic acid and 2-(1-methylcyclopentyl)benzoyl chloride were prepared by simply replacing the raw materials.

[0097] Preparation Example 3

[0098] The synthesis of 4-(1-methylcyclohexyl)benzoyl chloride is shown in the following reaction equation:

[0099]

[0100] Following the synthesis of 4-(1-methylcyclopentyl)benzoyl chloride, 4-(1-methylcyclohexyl)benzoic acid and 4-(1-methylcyclohexyl)benzoyl chloride were prepared by simply replacing the raw materials.

[0101] Preparation Example 4

[0102] The synthesis of 2-(1-methylcyclohexyl)benzoyl chloride is shown in the following reaction equation:

[0103]

[0104] Following the synthesis of 4-(1-methylcyclopentyl)benzoyl chloride, 4-(2-methylcyclohexyl)benzoic acid and 4-(2-methylcyclohexyl)benzoyl chloride were prepared by simply replacing the raw materials.

[0105] For example, this embodiment provides a method for preparing a carbazole-containing oxime ester photoinitiator, and the reaction equation is as follows:

[0106]

[0107] The specific method includes the following steps:

[0108] (1) Synthesis of intermediate P1-1

[0109] In a 2000 mL three-necked flask, add 10 g of N-ethylcarbazole and 1000 mL of dichloromethane. Slowly add 60 g of anhydrous aluminum trichloride. Cool to 0 °C and control the temperature between 0-5 °C. Slowly add 6.7 g of cyclohexylformyl chloride in 30 mL of dichloromethane solution. After the addition is complete, slowly heat to 20 °C and react for 1 hour. Then cool to 5 °C and control the temperature between 5-10 °C. Slowly add 12.6 g of 2,4-di-tert-butylbenzoyl chloride in 50 mL of dichloromethane solution. After the addition is complete, slowly heat to 20 °C and react for 4 hours. Cool down, add water to dissolve the mixture, wash the organic layer until neutral, dry with magnesium sulfate, filter off the desiccant, concentrate the organic layer to dryness, and crystallize twice with ethanol to obtain intermediate P1-1, 12 g.

[0110] The mass spectra of intermediate P1-1 were measured, m / z: 507.31.

[0111] (2) Synthesis of intermediate P1-2

[0112] In a 500 mL three-necked flask, add 10 g of intermediate P1-1, 100 mL of acetonitrile, 3 g of hydroxylamine hydrochloride, and 3.3 g of sodium acetate. Heat under reflux for 48 hours, cool down, pour the reaction solution into 1000 mL of water, filter to obtain a solid, crystallize from ethanol to obtain intermediate P1-2, 6.2 g.

[0113] The mass spectra of intermediate P1-1 were measured, m / z: 522.32.

[0114] (3) Synthesis of compound P1

[0115] In a 500 mL three-necked flask, add 10 g of intermediate P1-1, 100 mL of dichloromethane, and 2.5 g of triethylamine. Cool to 10-15 °C, then add dropwise a solution of 1.6 g of acetyl chloride in 10 mL of dichloromethane. After the addition is complete, slowly heat to 20-25 °C and react for 2 hours. Cool down and pour the reaction solution into 1000 mL of water. Separate the layers, wash the organic layer with water until neutral, dry with magnesium sulfate, filter off the drying agent, concentrate under reduced pressure to remove the solvent, and crystallize from ethanol to obtain compound P1, 8.2 g, HPLC purity 99.99% (see [link to flask]). Figure 1 ).

[0116] The mass spectra of intermediate P1 were measured, m / z: 564.34.

[0117] The obtained compound 1 was analyzed by NMR: 1 H-NMR (Bruker, Switzerland, Avance II 400MHz NMR spectrometer, CDCl3) δ8.88 (d, 1H), δ8.53 (d, 1H), δ8.00 (m, 1H), δ7.80 (d, 1H), δ7.71 (d, 1H), δ7.55–7.43 (m, 2H), δ7.26–7.18 (m, 2H), δ4.66 (m, 2H), δ4.00 (m, 1H), δ2.31 (s, 3H), δ1.80–1.60 (m, 6H), δ1.55–1.45 (m, 2H), δ1.40–1.34 (m, 12H), δ1.29 (s, 9H).

[0118] Based on the above synthesis examples, the following synthesis examples are provided, specifically including:

[0119] N-ethylcarbazole reacts sequentially with the corresponding starting material (acyl chloride) to give intermediate 1. Intermediate 1 then reacts to give intermediate 2. Intermediate 2 then reacts with the corresponding acyl chloride to give the compound. Details are shown in Table 1.

[0120] Table 1. Examples of final product synthesis

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127] The obtained compounds and the compounds used in the comparative examples were numbered for subsequent presentation, as follows:

[0128]

[0129]

[0130] The photoinitiator provided in this application can be applied to photocurable coatings, including but not limited to photocurable inks, photocurable coatings, color filter films (RGB), black matrix (BM), photo-spacers, and ribs.

[0131] Example 21

[0132] The specific methods for preparing UV-curable coatings and cured films are as follows:

[0133] In a yellow-light laboratory, a photocurable coating was prepared using 220 parts by weight of an acrylate copolymer (benzyl methacrylate: methacrylic acid: ethyl methacrylate = 70:10:20, Mw: 10000), 90 parts by weight of dipentaerythritol hexaacrylate, 5 parts by weight of a photoinitiator, and 1000 parts by weight of butanone. In this embodiment, the photoinitiator is compound P1 prepared in this application.

[0134] A 10cm×10cm blank glass plate was coated on a rotary spin coater at 600 rpm, pre-baked at 110℃ for 2 minutes, exposed to 50 mJ, and then post-baked at 280℃ for 40 minutes to obtain a cured film.

[0135] Examples 22-32

[0136] The preparation method is the same as in Example 21, except that the type and amount of photoinitiator are different.

[0137] Comparative Examples 1-4

[0138] The preparation method is the same as in Example 21, except that the type and amount of photoinitiator are different.

[0139] The cured membrane prepared above was tested for pencil hardness according to GB / T 6739-2006. The cured membrane was dissolved in acetonitrile solution, and the filtrate was obtained by extraction and purification. The migration rate was tested by gas chromatography-mass spectrometry (GC-MS). The test results are shown in Table 2.

[0140] Table 2 Specific Categories and Test Results

[0141]

[0142]

[0143] As can be seen from Examples 22, 28 to 31 in Table 2, when R1 is selected from tert-butyl and R2-R5 are selected from H, the migration rate is low.

[0144] Examples 25-27 show that when one of R1-R5 is selected from 1-methylcyclopentyl or 1-methylcyclohexyl, the curing effect is good and the hardness is high.

[0145] As shown in Example 32, the two initiators provided in this application, when used in combination, result in a cured film with high hardness.

[0146] Next, we will describe another initiator with a similar structure.

[0147] Preparation Example 5

[0148] The synthesis equation for intermediate A-1 is as follows:

[0149]

[0150] Under nitrogen protection, 5.5 g of 4-bromo-9-ethylcarbazole and 100 mL of tetrahydrofuran were added to a 500 mL three-necked flask. The mixture was cooled to -60 °C, and then 12.5 mL of a 1.6 M butyllithium solution in n-hexane was slowly added dropwise at -60 to -70 °C. After the addition was complete, the mixture was maintained at -60 to -70 °C for 30 minutes, and then 2 g of benzonitrile in 20 mL of tetrahydrofuran solution was slowly added. After the addition was complete, the mixture was slowly heated to room temperature and reacted for 4 hours. Then, 50 mL of 5% hydrochloric acid was slowly added, and the mixture was heated to reflux and reacted for 2 hours. The mixture was cooled, dichloromethane was added, and the layers were separated. The organic layer was washed with water until neutral, concentrated to dryness, and then crystallized from ethanol to give 4.1 g of the intermediate shown in A-1.

[0151] The intermediate shown in A-1 was analyzed by mass spectrometry, m / z: 299.13.

[0152] Preparation Example 6

[0153] The synthesis equation for intermediate A-2 is as follows:

[0154]

[0155] Following the synthesis of intermediate A-1, intermediate A-2 was prepared.

[0156] The intermediate shown in A-2 was analyzed by mass spectrometry, m / z: 313.15.

[0157] Preparation Example 7

[0158] The synthesis equation for intermediate A-3 is as follows:

[0159]

[0160] Following the synthesis of intermediate A-1, intermediate A-2 was prepared.

[0161] The intermediate shown in A-3 was analyzed by mass spectrometry, m / z: 355.19.

[0162] Preparation Example 8

[0163] The synthesis equation for intermediate B-1 is as follows:

[0164]

[0165] In a 500 mL three-necked flask, add 3 g of intermediate A-1 and 100 mL of dichloromethane. Slowly add 4.5 g of anhydrous aluminum trichloride. Cool to 0 °C and control the temperature between 0 and 5 °C. Slowly add 5 mL of a dichloromethane solution containing 0.92 g of acetyl chloride. After the addition is complete, slowly raise the temperature to 20 °C and react for 1 hour. Add water to the mixture to separate the contents. Wash the organic layer until neutral. Dry with magnesium sulfate, filter off the desiccant, concentrate the organic layer to dryness, and crystallize with ethanol to obtain 2.6 g of intermediate B-1.

[0166] The mass spectra of intermediate B-1 were measured at m / z: 341.14.

[0167] Preparation Examples 9-19

[0168] Following the synthesis of intermediate B-1, the following intermediates were prepared by reacting the corresponding starting material 1 with the corresponding acyl chloride, and the mass spectra of the prepared intermediates were measured.

[0169] The details are shown in Table 3:

[0170] Table 3 Preparation Examples 9-19

[0171]

[0172]

[0173]

[0174]

[0175] For example:

[0176] Preparation Example 20

[0177] The synthesis equation for intermediate C-1 is as follows:

[0178]

[0179] In a 500 mL three-necked flask, add 7 g of intermediate B-1, 60 mL of acetonitrile, 2.6 g of hydroxylamine hydrochloride, and 2.8 g of sodium acetate. Heat under reflux for 48 hours, cool down, pour the reaction solution into 600 mL of water, filter to obtain a solid, crystallize from ethanol to obtain intermediate C-1, 5.2 g.

[0180] The mass spectra of intermediate C-1 were measured at m / z: 356.15.

[0181] Following the synthesis of intermediate C-1, the following intermediates were prepared by reacting the corresponding starting material 2 with hydroxylamine hydrochloride, and the mass spectra of the prepared intermediates were measured.

[0182] Preparation Examples 21-31

[0183] As shown in Table 4:

[0184] Table 4 Preparation Examples 21-31

[0185]

[0186]

[0187]

[0188] Finally, the second intermediate reacts with the third acyl chloride starting material to obtain an oxime ester photoinitiator containing a carbazole group.

[0189] The general structural formula of the third type of acyl chloride raw material is:

[0190]

[0191] Among them, R 41 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, 3-C20 cycloalkyl-substituted C1-C20 branched alkyl, and C6-C20 aryl.

[0192] Example 33

[0193] The preparation of an exemplary embodiment 33 is described by the following equation:

[0194]

[0195] In a 500 mL three-necked flask, add 7.1 g of intermediate C-1, 80 mL of dichloromethane, and 2.4 g of triethylamine. Cool to 10-15 °C, then add dropwise a solution of 1.6 g of acetyl chloride in 10 mL of dichloromethane. After the addition is complete, slowly heat to 20-25 °C and react for 2 hours. Cool down and pour the reaction mixture into 600 mL of water. Separate the layers, wash the organic layer with water until neutral, dry with magnesium sulfate, filter off the drying agent, concentrate under reduced pressure to remove the solvent, and crystallize from ethanol to obtain compound S1, 5.1 g. HPLC chromatogram is shown below. Figure 2 .

[0196] The mass spectra of intermediate S1 were measured, m / z: 398.16.

[0197] Elemental analysis of the obtained compound S1 yielded the following results: theoretical values: C, 75.36%, H, 5.57%, N, 7.03%; measured values: C, 75.39%, H, 5.56%, N, 7.00%.

[0198] Examples 34-53

[0199] Following the synthesis of S1, the compound was prepared by reacting reactant 3 with the corresponding acyl chloride, and the mass spectra (m / z) of the compound were measured. Details are shown in Table 5.

[0200] Table 5 Examples 34-53

[0201]

[0202]

[0203]

[0204]

[0205] Example 54

[0206] Preparation of UV-curable coatings and cured films:

[0207] In a yellow-light laboratory, a photocurable coating was prepared using 170 parts by weight of an acrylate copolymer (benzyl methacrylate: methacrylic acid: ethyl methacrylate = 70:10:20, Mw: 10000), 90 parts by weight of the compound shown in formula (I-1), 20 parts by weight of dipentaerythritol hexaacrylate, 5 parts by weight of a photoinitiator, and 1000 parts by weight of butanone. In this embodiment, the photoinitiator was the compound obtained in Example 34 of this application.

[0208] The compounds represented by formula (I-1) are as follows:

[0209]

[0210] A 10cm×10cm blank glass plate was coated on a rotary spin coater at 600 rpm, pre-baked at 90°C for 5 minutes, exposed to 50 mJ, and then post-baked at 100°C for 60 minutes to obtain a cured film.

[0211] Examples 55-60

[0212] The preparation method is the same as in Example 54, except that the type and amount of photoinitiator are different.

[0213] Comparative Examples 5-7

[0214] The preparation method is the same as in Example 54, except that the type and amount of photoinitiator are different.

[0215] Comparative Examples 8-10

[0216] The preparation method is the same as in Example 54, except that the type and amount of photoinitiator are different. In addition, the baking temperature of Comparative Examples 8-10 is 230°C and the time is 40 min.

[0217] The cured membrane prepared above was tested for pencil hardness according to GB / T 6739-2006. The cured membrane was dissolved in acetonitrile solution, and the filtrate was obtained by extraction and purification. The migration rate was tested by gas chromatography-mass spectrometry (GC-MS). The test results are shown in Table 6 below.

[0218] Table 6 Examples 54-61 and Comparative Examples 5-10

[0219]

[0220]

[0221] As shown in Table 6, the cured film obtained in this application has high hardness and low migration rate.

[0222] As can be seen from Examples 55 and 59, when R1 is selected from tert-butyl and R2-R5 are selected from H, the migration rate is low.

[0223] Compared with Examples 54-60 and Comparative Examples 5-7 and 8-10, the cured film obtained by this application has high hardness and low migration rate. At the same post-baking temperature (100°C), the cured film using the initiator provided by this application has high hardness. Increasing the post-baking temperature (Comparative Example 8-10, 230°C) improves the hardness of the cured film, but it is still less than that of the case with the initiator provided by this application at a lower post-baking temperature (100°C).

[0224] The initiator structures used in Comparative Examples 5-10 are as follows:

[0225]

[0226] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A carbazole-containing oxime ester photoinitiator, characterized in that, Its general structural formula is: ， Among them, at least one of R1-R5 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl; R 21 Selected from C1-C20 straight-chain alkyl, C1-C20 branched-chain alkyl, C3-C20 cycloalkyl, and C6-C20 aryl; R 31 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, and C3-C20 cycloalkyl-substituted C1-C20 branched alkyl. R 41 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, 3-C20 cycloalkyl-substituted C1-C20 branched alkyl, and C6-C20 aryl; or, The general structural formula of the oxime ester photoinitiator containing a carbazole group is: ， Among them, R1-R5 are selected from H, straight-chain alkyl groups of C1-C20, branched alkyl groups of C1-C20, and cycloalkyl groups of C3-C20; R 21 Selected from C1-C20 straight-chain alkyl, C1-C20 branched-chain alkyl, C3-C20 cycloalkyl, and C6-C20 aryl; R 31 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, and C3-C20 cycloalkyl-substituted C1-C20 branched alkyl. R 41 Selected from C1-C20 straight-chain alkyl, C1-C20 branched alkyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl-substituted C1-C20 straight-chain alkyl, 3-C20 cycloalkyl-substituted C1-C20 branched alkyl, and C6-C20 aryl.

2. The carbazole-containing oxime ester photoinitiator according to claim 1, characterized in that, Its general structural formula is: ， Among them, at least two of R1, R3, and R5 are selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

3. The carbazole-containing oxime ester photoinitiator according to claim 2, characterized in that, R1 is selected from tert-butyl, 1-methylcyclopentyl, and 1-methylcyclohexyl.

4. The carbazole-containing oxime ester photoinitiator according to claim 1, characterized in that, Its general structural formula is: ， Among them, R 21 Selected from methyl, ethyl, propyl, butyl, pentyl, and hexyl.

5. The carbazole-containing oxime ester photoinitiator according to claim 1, characterized in that, Its general structural formula is: ， Among them, R 31 R 41 Each is independently selected from C1-C20 straight-chain alkyl groups substituted with methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl.

6. The carbazole-containing oxime ester photoinitiator according to claim 1, characterized in that, Its general structural formula is: ； Wherein, R1 is selected from H, methyl, tert-butyl, R 21 Selected from methyl, ethyl, propyl, butyl, pentyl, and hexyl.

7. The carbazole-containing oxime ester photoinitiator according to claim 1, characterized in that, Its general structural formula is: ； Among them, R 31 R 41 Each is independently selected from C1-C20 straight-chain alkyl groups substituted with methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl.

8. A UV-curable coating, characterized in that, Its raw materials include the oxime ester photoinitiator containing a carbazole group as described in any one of claims 1-7.

9. The photocurable coating according to claim 8, characterized in that, The photocurable coating also includes copolymers, monomers, solvents, and additives.

10. The photocurable coating according to claim 8, characterized in that, The raw materials of the photocurable coating include a variety of oxime ester photoinitiators containing carbazole groups.

11. The photocurable coating according to claim 10, characterized in that, The raw materials of the photocurable coating include two types of oxime photoinitiators containing carbazole groups.

12. A cured film, characterized in that, It is prepared using the photocurable coating according to any one of claims 8-11.

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