Carbazole oxime ester photoinitiator, and preparation method therefor and use thereof

Abstract

A carbazole oxime ester photoinitiator, and a preparation method therefor and the use thereof. The carbazole oxime ester photoinitiator has a structure as represented by formula I. By means of simple modification of the carbazole parent, the solubility of the oxime ester photoinitiator can be improved without increasing the cost, the solubility of the oxime ester photoinitiator in an organic solvent can be improved, so as to improve the practical applicability thereof, and the oxime ester photoinitiator has high initiation efficiency and good stability, thereby meeting requirements with regard to the field of photocuring.

Description

A carbazole oxime ester photoinitiator and its preparation method and application Technical Field

[0001] The present invention relates to the field of organic chemistry, and specifically relates to a carbazole oxime ester photoinitiator, a preparation method thereof, and an application thereof. Background Art

[0002] In the field of photocuring, oxime ester compounds have been widely used as photoinitiators. Compared with commonly used α-amino ketones, benzoin ethers, and phosphine oxide compounds, oxime ester photoinitiators have higher sensitivity and excellent photoinitiation efficiency. Therefore, they are widely used in color filters, black matrices, photospacers, and liquid crystal segmentation alignment.

[0003] To improve the solubility and photosensitivity of oxime ester photoinitiators, as well as their application stability, researchers have developed various oxime ester initiators with different structures. Through various structural modifications, some of these initiators have improved their solubility in organic solvents, while others have improved their application performance during the photocuring process.

[0004] Furthermore, in the actual production of oxime ester photoinitiators, different crystal configurations exist, and different crystal forms directly affect the compound's solubility in the solvent. Therefore, improving solubility requires balancing photosensitivity and application stability. Furthermore, the production cost of oxime ester initiators also needs to be considered.

[0005] Therefore, in the existing technology, there are still problems and limitations in solubility, photosensitivity and application stability, which need to be further improved and resolved.

[0006] Summary of the Invention

[0007] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0008] The present application provides a carbazole oxime ester photoinitiator, a preparation method thereof, and an application thereof.

[0009] In a first aspect, the present application provides a carbazole oxime ester photoinitiator having a structure shown in the following formula I:

[0010] The carbazole oxime ester photoinitiator of the present application improves the solubility of the oxime ester photoinitiator without increasing the cost through simple modification of the carbazole matrix, can increase the solubility of the oxime ester photoinitiator in organic solvents to improve its practical applicability, has high initiation efficiency and good stability, and can meet the needs of the photocuring field.

[0011] In a second aspect, the present application provides a method for preparing the carbazole oxime ester photoinitiator as described above, the preparation method comprising the following steps:

[0012] (1) Carbazole and halogenated isooctane undergo substitution reaction to obtain compound A, and the reaction formula is as follows:

[0013] (2) Compound A and propionyl compound B undergo Friedel-Crafts reaction to obtain compound C. The reaction formula is as follows:

[0014] (3) Compound C reacts with isoamyl nitrate in the presence of hydrochloric acid to produce compound D. The reaction formula is as follows:

[0015] (4) Compound D is subjected to an esterification reaction with acetic anhydride to obtain a carbazole oxime ester photoinitiator represented by Formula I, as shown in the following reaction formula:

[0016] Preferably, the molar ratio of the carbazole to the halogenated isooctane in step (1) is 1.2:1-1:1.2, for example, 1.2:1, 1.1:1, 1:1, 1:1.1 or 1:1.2.

[0017] Preferably, the substitution reaction in step (1) is carried out in the presence of a basic substance.

[0018] Preferably, the alkaline substance is selected from any one or a combination of at least two of potassium hydroxide, sodium hydroxide or ammonia water.

[0019] Preferably, the substitution reaction in step (1) is carried out in the presence of a phase transfer catalyst.

[0020] Preferably, the phase transfer catalyst is selected from tetrabutylammonium bromide.

[0021] Preferably, the substitution reaction in step (1) is carried out in a solvent, and the solvent is water.

[0022] Preferably, the temperature of the substitution reaction in step (1) is 40-80°C (e.g., 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C), and the reaction time is 4-8h (e.g., 4h, 5h, 6h, 7h or 8h).

[0023] Preferably, the molar ratio of compound A to compound B in step (2) is 1:2.5-1.2:2, for example, 1:2.5, 1:2, 1:1.8, 1:1.5, 1:1, 1.1:1, 1.2:1, 1.2:1.5, 1.2:1.8 or 1.2:2.

[0024] Preferably, the Friedel-Crafts reaction in step (2) is carried out in the presence of a catalyst.

[0025] Preferably, the catalyst is selected from aluminum chloride and / or zinc chloride, but is not limited thereto.

[0026] In the present application, there is no particular limitation on the type of solvent used in the reaction of step (2), as long as it can dissolve the raw materials and has no adverse effect on the reaction. Dichloromethane and / or dichloroethane are preferred.

[0027] Preferably, the temperature of the Friedel-Crafts reaction in step (2) is 0-10°C (e.g., 0°C, 1°C, 2°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C or 10°C), and the reaction time is 1-3h (e.g., 1h, 2h or 3h).

[0028] Preferably, the molar ratio of compound C to isoamyl nitrate in step (3) is 1:2.5-1.2:2, for example, 1:2.5, 1:2, 1:1.8, 1:1.5, 1:1, 1.1:1, 1.2:1, 1.2:1.5, 1.2:1.8 or 1.2:2.

[0029] Preferably, the temperature of the oximation reaction in step (3) is 20-40°C (e.g., 20°C, 25°C, 28°C, 30°C, 35°C, 38°C or 40°C), and the reaction time is 8-12h (e.g., 8h, 9h, 10h, 11h or 12h).

[0030] In the present application, there is no particular limitation on the type of solvent used in the oximation reaction in step (3), as long as it can dissolve the raw materials and has no adverse effect on the reaction. Preferably, it is any one of DMF, DMSO or acetonitrile or a combination of at least two of them.

[0031] Preferably, the molar ratio of compound D to acetic anhydride in step (4) is 1:5-1.2:2, for example, 1:5, 1:4.5, 1:4, 1:3.5, 1:3, 1:2, 1:1, 1:2, 1.1:1, 1.2:1 or 1.2:2.

[0032] Preferably, the esterification reaction in step (4) is carried out at room temperature, and the reaction time is 2-4 h, such as 2 h, 2.5 h, 3 h, 3.5 h or 4 h.

[0033] Preferably, the solvent for the esterification reaction in step (4) is selected from any one of methanol, ethanol, isopropanol, 4-dimethylaminopyridine, dimethyl sulfoxide or toluene, or a combination of at least two thereof.

[0034] During the post-treatment process of the esterification product obtained in step (4) of the present application, a mixture of acetone and alcohol solvents is used for recrystallization.

[0035] Preferably, the alcohol solvent is selected from methanol, ethanol or isopropanol.

[0036] The present application utilizes the preparation method described above to prepare the carbazole oxime ester photoinitiator, and the preparation method is simple and efficient, and the product yield is high.

[0037] In a third aspect, the present application provides a use of the above-mentioned carbazole oxime ester photoinitiator in the field of photocuring.

[0038] In a fourth aspect, the present application provides a photocurable resin composition comprising the following components: (A) an acrylate copolymer, (B) a polymerizable compound, and (C) the carbazole oxime ester photoinitiator as described above.

[0039] Preferably, the acrylate copolymer is selected from the group consisting of copolymers of benzyl methacrylate, methacrylic acid and hydroxyethyl methacrylate.

[0040] Preferably, the polymerizable compound is selected from any one or a combination of at least two of dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate or dipentaerythritol pentaacrylate.

[0041] Preferably, based on 100 parts by weight of the total weight of the photocurable resin composition, the content of each component in the photocurable resin composition is as follows: (A) 10-80 parts by weight (for example, 10 parts by weight, 15 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight or 80 parts by weight) of an acrylate copolymer, (B) 20-80 parts by weight (for example, 20 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight or 80 parts by weight) of a polymerizable compound, and (C) 1-6 parts by weight (for example, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight or 5 parts by weight) of the carbazole oxime ester photoinitiator as described above.

[0042] Preferably, the photocurable resin composition further comprises a solvent.

[0043] Preferably, the solvent is selected from any one of butanone, propylene glycol methyl ether acetate (PGMEA), ethyl 3-ethoxypropionate, propylene glycol methyl ether (PM) or ethylene glycol ethyl ether, or a combination of at least two thereof.

[0044] In a fifth aspect, the present application provides a cured film, which is obtained by curing the photocurable resin composition as described above.

[0045] In a sixth aspect, the present application provides an EL element, which includes the photocurable resin composition as described above or the cured film as described above.

[0046] In a seventh aspect, the present application provides a display device, comprising the photocurable resin composition as described above, the cured film as described above, or the EL element as described above.

[0047] Compared with the related art, this application has the following beneficial effects:

[0048] The carbazole oxime ester photoinitiator of the present application improves the solubility of the oxime ester photoinitiator without increasing the cost through simple modification of the carbazole matrix, and can increase the solubility of the oxime ester photoinitiator in organic solvents to improve its practical applicability. It has high initiation efficiency and good stability, and can meet the needs of the photocuring field.

[0049] Still other aspects will become apparent upon reading and understanding the detailed description. DETAILED DESCRIPTION

[0050] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0051] Example 1

[0052] (1) Preparation of isooctylcarbazole

[0053] To a 200 mL four-necked flask, 16.7 g of carbazole, 11.2 g of potassium hydroxide, 15 g of water, 21.1 g of isobutyl bromide, and 1 g of tetrabutylammonium bromide were added. The mixture was heated at 50°C with stirring. Liquid chromatography was used to monitor the reaction until no further changes occurred. The reaction solution was poured into 50 g of water, extracted with dichloromethane (20 mL x 3), washed with water, and the organic layer was rotary evaporated to obtain 26.5 g of pale yellow solid isooctylcarbazole (95% yield). The product structure was confirmed by mass spectrometry: MS (m / z): 280 (M+1). + .

[0054] (2) Preparation of 3,6-bis(3-propionyl-1-yl)-9-isobutylcarbazole

[0055] To a 200mL four-necked flask, add 14g of isobutylcarbazole, 20mL of dichloromethane, and 13.3g of aluminum trichloride. Stir at 10°C. Add a dichloromethane-propionyl chloride solution (10mL of dichloromethane, 9.2g of propionyl chloride) dropwise over approximately 1 hour. Stir for 2 hours. Pour the reaction mixture into 100mL of water, separate the dichloromethane layer, wash with water until neutral, and recrystallize from ethanol to obtain 16.6g of a white solid in 85% yield. The product structure was confirmed by H NMR and mass spectrometry.

[0056] The H-NMR spectrum data are as follows: 1H-NMR (400 MHz, deuterated chloroform): δ 8.73-8.73 (s, 2H), 8.12-8.10 (d, 2H), 7.38-7.35 (d, 2H), 4.15-4.13 (d, 2H), 3.12-3.07 (m, 4H), 2.01-1.95 (m, 1H), 1.38-1.15 (m, 14H), 0.87-0.76 (m, 6H).

[0057] MS (m / z): 392 (M+1) + .

[0058] (3) Preparation of 3,6-bis(1-oxime acetate-3-propionyl-1-yl)-9-isobutylcarbazole

[0059] To a 100mL four-necked flask, 3.9g of 3,6-bis(3-propionyl-1-yl)-9-isobutylcarbazole, 11.8g of isoamyl nitrite, 10g of 37% hydrochloric acid, and 20mL of DMF were added. The mixture was stirred at room temperature for 3h. The reaction was monitored by liquid phase chromatography. After completion, the mixture was poured into water. A solid precipitated and filtered to obtain the oximation intermediate, which was then added directly to the feed. 11g of acetic anhydride and 20mL of 4-dimethylaminopyridine were added as the solvent. The mixture was stirred at room temperature for 2h. The reaction was monitored by liquid phase chromatography until completion. The product solution was poured into water. The product precipitated and filtered to obtain 4.5g of the product. The product was then added to a mixture of 5mL of acetone and 5mL of ethanol. The mixture was heated to dissolve and cooled for crystallization to obtain a pale yellow solid product with a yield of 86%. The product structure was confirmed by H NMR and mass spectrometry:

[0060] MS (m / z): 534 (M+1) + .

[0061] The H-NMR spectrum data are as follows: 1 H-NMR (400 MHz, deuterated chloroform): δ 8.89-8.24 (m, 2H), 8.27-8.24 (m, 2H), 7.41-7.39 (d, 2H), 4.16-4.11 (m, 2H), 2.54-1.99 (m, 12H), 1.97-1.94 (m, 1H), 1.35-1.10 (m, 8H), 0.96-0.77 (m, 6H).

[0062] Example 2: Other conditions remain unchanged, and the product obtained in Example 1 is added with 5 mL of acetone and 5 mL of methanol for recrystallization.

[0063] Example 3: Other conditions remain unchanged, the product obtained in Example 1 above was added with 5 mL of acetone and 5 mL of isopropanol for recrystallization.

[0064] Comparative Example 1: With other conditions unchanged, the product obtained in Example 1 was added with 10 mL of acetone for recrystallization.

[0065] Comparative Example 2: With other conditions unchanged, the product obtained in Example 1 was added into 10 mL of ethanol for recrystallization.

[0066] Comparative Example 3: With other conditions unchanged, the product obtained in Example 1 was added with 10 mL of acetonitrile for recrystallization.

[0067] Comparative Example 4: With other conditions unchanged, the product obtained in Example 1 was added with 10 mL of methanol for recrystallization.

[0068] Comparative Example 5: Referring to the synthesis method of Example 1, the second step reaction raw material isooctylcarbazole was replaced with ethylcarbazole, and the post-treatment conditions remained unchanged.

[0069] Comparative Example 6: Referring to the synthesis method of Example 1, the second step reaction raw material isooctylcarbazole is replaced with ethylcarbazole, and the product is recrystallized with 10 mL of methanol during post-treatment.

[0070] Comparative Example 7: Referring to the synthesis method of Example 1, the raw material propionyl chloride in the second step reaction was replaced with cyclohexylpropionyl chloride, and the post-treatment conditions remained unchanged.

[0071] Comparative Example 8: Referring to the synthesis method of Example 1, the raw material propionyl chloride in the second step reaction was replaced with octanoyl chloride, and the product was recrystallized using 10 mL of acetone during the post-treatment process.

[0072] Performance evaluation

[0073] The curing speed, odor, migration, solubility and other application properties of the photoinitiator represented by formula (I) of the present application were evaluated by preparing a representative photocurable resin composition. The specific steps are as follows:

[0074] (1) Prepare a photocurable resin composition as follows:

[0075] The acrylic acid ester copolymer is a copolymer (Mv=10000) of benzyl methacrylate, methacrylic acid, and hydroxyethyl methacrylate (molar ratio 70:10:20).

[0076] In the above composition, the photoinitiator is the product prepared in Examples 1-3 or the product in Comparative Examples 1-8.

[0077] (2) Curing speed

[0078] The above composition was stirred under a yellow light lamp, and the material was rolled onto a PET template to form a film. The film was dried at 90°C for 2 minutes to obtain a film with a dry film thickness of 5 μm. The film was then cooled to room temperature and illuminated with an LED lamp (EXECURE 4000, 365 nm LED light source, energy 50 mJ / cm 2) is irradiated to expose the coating film to cure it into a film.

[0079] The coating was evaluated by the number of irradiations required to cure into a cured film. The more irradiations required, the less satisfactory the curing speed.

[0080] (3) Migration

[0081] According to the above formula, other conditions remain unchanged and the irradiation light source energy is adjusted to 500mJ / cm 2 , so that it is fully cured into a film.

[0082] Using the GC-MS test method, 5 g of the sample film prepared in the same way as above was cut into a suitable size and placed in a headspace bottle for use. Headspace sampling was used to observe whether there was any overflow gas output (except carbon dioxide and its own solvent peak).

[0083] Instruments: Agilent 7890B gas chromatograph, Agilent 7697A headspace sampler, Agilent 7010B mass spectrometer.

[0084] Chromatographic column: Agilent HP-5ms column; vaporization temperature: 280°C; temperature program: 60°C-3 min-20°C / min-280°C-10 min.

[0085] Headspace conditions: heating box: 110°C; quantitative loop: 120°C; transfer line: 140°C; equilibration time: 30 min.

[0086] Mass spectrometry conditions: ion source temperature: 280°C; electron energy: 70 eV; scanning range (m / z): 30-400.

[0087] (4) Solubility

[0088] The solubility of the photoinitiator in the reactive diluent and oligomer is an important indicator for measuring the application performance of the initiator. The solubility of the photoinitiator in PGMEA is one of the index parameters representing its solubility and measuring the application performance of the photoinitiator. The photoinitiators obtained in Examples 1-3 and Comparative Examples 1-8 were selected and their solubility in PGMEA at 25°C was tested respectively. The results are shown in Table 1.

[0089] Table 1

[0090] As can be seen from Table 1, the carbazole oxime ester initiator of the present application has a good curing effect after application and has no migration, and the product obtained by the synthesis method described in the present application has excellent solubility.

[0091] The applicant declares that while the above-mentioned embodiments are used to illustrate the carbazole oxime ester photoinitiator, its preparation method, and application, this application is not limited to the above-mentioned embodiments, and does not necessarily rely on the above-mentioned embodiments for implementation. Persons skilled in the art should understand that any improvements to this application, equivalent substitutions for the raw materials used in this application, addition of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of this application.

Claims

1. A carbazole oxime ester photoinitiator having a structure as shown in the following formula I:

2. A method for preparing the carbazole oxime ester photoinitiator according to claim 1, comprising the following steps: (1) Carbazole and halogenated isooctane undergo substitution reaction to obtain compound A, and the reaction formula is as follows: (2) Compound A and propionyl compound B undergo Friedel-Crafts reaction to obtain compound C. The reaction formula is as follows: (3) Compound C undergoes oximation reaction with isoamyl nitrate in the presence of hydrochloric acid to obtain compound D. The reaction formula is as follows: (4) Compound D is subjected to an esterification reaction with acetic anhydride to obtain a carbazole oxime ester photoinitiator represented by formula I, and the reaction formula is as follows:

3. The preparation method according to claim 2, wherein The molar ratio of the carbazole to the halogenated isooctane in step (1) is 1.2:1-1:1.2; Preferably, the substitution reaction in step (1) is carried out in the presence of an alkaline substance; Preferably, the alkaline substance is selected from any one or a combination of at least two of potassium hydroxide, sodium hydroxide or ammonia water; Preferably, the substitution reaction in step (1) is carried out in the presence of a phase transfer catalyst; Preferably, the phase transfer catalyst is selected from tetrabutylammonium bromide; Preferably, the substitution reaction in step (1) is carried out in a solvent, and the solvent is water; Preferably, the temperature of the substitution reaction in step (1) is 40-80° C., and the reaction time is 4-8 h; Preferably, the molar ratio of compound A to compound B in step (2) is 1:2.5-1.2:2; Preferably, the Friedel-Crafts reaction in step (2) is carried out in the presence of a catalyst; Preferably, the catalyst is selected from aluminum chloride and / or zinc chloride; Preferably, the solvent for the Friedel-Crafts reaction in step (2) is dichloromethane and / or dichloroethane; Preferably, the temperature of the Friedel-Crafts reaction in step (2) is 0-10° C., and the reaction time is 1-3 h.

4. The preparation method according to claim 2 or 3, wherein In step (3), the molar ratio of compound C to isoamyl nitrate is 1:2.5-1.2:2; Preferably, the temperature of the oximation reaction in step (3) is 20-40° C., and the reaction time is 8-12 h; Preferably, the solvent for the oximation reaction in step (3) is selected from any one of DMF, DMSO or acetonitrile or a combination of at least two thereof; Preferably, the molar ratio of compound D to acetic anhydride in step (4) is 1:5-1.2:2; Preferably, the esterification reaction in step (4) is carried out at room temperature for 2-4 hours; Preferably, the solvent for the esterification reaction in step (4) is selected from any one of methanol, ethanol, isopropanol, 4-dimethylaminopyridine, dimethyl sulfoxide or toluene, or a combination of at least two thereof; Preferably, during the post-treatment of the esterification product obtained in step (4), a mixture of acetone and an alcohol solvent is used for recrystallization; Preferably, the alcohol solvent is selected from methanol, ethanol or isopropanol.

5. Use of the carbazole oxime ester photoinitiator according to claim 1 in the field of photocuring. 6 . A photocurable resin composition comprising the following components: (A) an acrylate copolymer, (B) a polymerizable compound, and (C) the carbazole oxime ester photoinitiator according to claim 1 .

7. The photocurable resin composition according to claim 6, wherein The acrylate copolymer is selected from the copolymer of benzyl methacrylate, methacrylic acid and hydroxyethyl methacrylate; Preferably, the polymerizable compound is selected from any one or a combination of at least two of dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate or dipentaerythritol pentaacrylate; Preferably, based on 100 parts by total weight of the photocurable resin composition, the contents of the components in the photocurable resin composition are as follows: (A) 10-80 parts by weight of an acrylate copolymer, (B) 20-80 parts by weight of a polymerizable compound, and (C) 1-6 parts by weight of the carbazole oxime ester photoinitiator as described above; Preferably, the photocurable resin composition further comprises a solvent; Preferably, the solvent is selected from any one of butanone, propylene glycol methyl ether acetate, ethyl 3-ethoxypropionate, propylene glycol methyl ether or ethylene glycol ethyl acetate, or a combination of at least two thereof. 8 . A cured film obtained by curing the photocurable resin composition according to claim 6 or 7 .

9. An EL element comprising the photocurable resin composition according to claim 6 or 7 or the cured film according to claim 8. 10 . A display device comprising the photocurable resin composition according to claim 6 or 7 , the cured film according to claim 8 , or the EL element according to claim 9 .

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