Carbazole oxime ester photoinitiator as well as preparation method and application thereof

Abstract

The invention provides a carbazole oxime ester photoinitiator and a preparation method and application thereof, the carbazole oxime ester photoinitiator has a structure as shown in a formula I. According to the carbazole oxime ester photoinitiator, through simple modification of a carbazole matrix, the dissolving property of the oxime ester photoinitiator is improved under the condition that the cost is not increased, and the stability of the carbazole oxime ester photoinitiator is improved. The solubility of the oxime ester photoinitiator in an organic solvent can be improved, so that the practical applicability of the oxime ester photoinitiator is improved, and the oxime ester photoinitiator has high initiation efficiency and good stability and can meet the requirements of the photocuring field.

Description

Technical Field

[0001] The invention belongs to the field of organic chemistry, and in particular relates to a carbazole oxime ester photoinitiator and a preparation method and 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, so they have been widely used in color filters, black matrices, photospacers, liquid crystal segmentation orientation and other fields.

[0003] In order to improve the solubility and photosensitivity of oxime ester photoinitiators and improve their application stability, researchers have developed oxime ester initiators with various structures. Through different 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] In addition, in the actual production of oxime ester photoinitiators, due to the presence of different crystal configurations, different crystal forms will directly affect the solubility of the compound in the solvent. Therefore, it is necessary to balance photosensitivity and application stability while improving solubility. In addition, the production cost of oxime ester initiators is also a problem that needs to be considered. Therefore, in the prior art, there are still problems and limitations in solubility, photosensitivity and application stability, which need to be further improved and solved. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a carbazole oxime ester photoinitiator and a preparation method and application thereof.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a carbazole oxime ester photoinitiator having a structure as shown in the following formula I:

[0008]

[0009] The carbazole oxime ester photoinitiator of the present invention 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 an organic solvent, thereby improving its practical applicability, has high initiation efficiency and good stability, and can meet the needs of the photocuring field.

[0010] On the other hand, the present invention provides a method for preparing the above-mentioned carbazole oxime ester photoinitiator, the preparation method comprising the following steps:

[0011] (1) Carbazole undergoes a substitution reaction with halogenated isooctane to obtain compound A, and the reaction formula is as follows:

[0012]

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

[0015]

[0016] (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:

[0017]

[0018] (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:

[0019]

[0020] 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.

[0021] Preferably, the substitution reaction in step (1) is carried out in the presence of an alkaline substance.

[0022] Preferably, the alkaline substance is selected from any one or a combination of at least two of potassium hydroxide, sodium hydroxide or ammonia water.

[0023] Preferably, the substitution reaction in step (1) is carried out in the presence of a phase transfer catalyst.

[0024] Preferably, the phase transfer catalyst is selected from tetrabutylammonium bromide.

[0025] Preferably, the substitution reaction in step (1) is carried out in a solvent, and the solvent is water.

[0026] 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).

[0027] 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.

[0028] Preferably, the Friedel-Crafts reaction in step (2) is carried out in the presence of a catalyst.

[0029] Preferably, the catalyst is selected from aluminum chloride and / or zinc chloride, but is not limited thereto.

[0030] In the present invention, the type of solvent used in the reaction of step (2) is not particularly limited, as long as it can dissolve the raw materials and has no adverse effect on the reaction, preferably dichloromethane and / or dichloroethane.

[0031] 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).

[0032] 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.

[0033] 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).

[0034] In the present invention, there is no particular limitation on the type of solvent used in the oximation reaction of 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.

[0035] 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.

[0036] Preferably, the esterification reaction in step (4) is carried out at room temperature, and the reaction time is 2-4 h, for example 2 h, 2.5 h, 3 h, 3.5 h or 4 h.

[0037] 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.

[0038] In the post-treatment process of the esterification product obtained in step (4) of the present invention, acetone and an alcohol solvent are mixed for recrystallization.

[0039] Preferably, the alcohol solvent is selected from methanol, ethanol or isopropanol.

[0040] The present invention utilizes the above-mentioned preparation method to prepare the carbazole oxime ester photoinitiator, and the preparation method is simple and efficient, and the product yield is high.

[0041] In another aspect, the present invention provides a use of the above-mentioned carbazole oxime ester photoinitiator in the field of photocuring.

[0042] In another aspect, the present invention 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.

[0043] Preferably, the acrylate copolymer is selected from copolymers of benzyl methacrylate, methacrylic acid and hydroxyethyl methacrylate.

[0044] 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.

[0045] 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 (e.g., 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 (e.g., 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 (e.g., 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.

[0046] Preferably, the photocurable resin composition further comprises a solvent.

[0047] 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.

[0048] In another aspect, the present invention provides a cured film obtained by curing the photocurable resin composition as described above.

[0049] In another aspect, the present invention provides an EL element comprising the photocurable resin composition as described above or the cured film as described above.

[0050] In another aspect, the present invention 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.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The carbazole oxime ester photoinitiator of the present invention 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 an organic solvent, thereby improving its practical applicability, has high initiation efficiency and good stability, and can meet the needs of the photocuring field. DETAILED DESCRIPTION

[0053] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0054] Example 1

[0055]

[0056] (1) Preparation of isooctylcarbazole

[0057] Add 16.7g carbazole, 11.2g potassium hydroxide, 15g water, 21.1g isobutyl bromide, 1g tetrabutylammonium bromide to a 200mL four-necked flask, heat and stir at 50℃, the liquid phase tracking reaction will not change, pour the reaction solution into 50g water, extract with dichloromethane (20mL*3), wash with water, and evaporate the organic layer to obtain 26.5g light yellow solid isooctylcarbazole, with a yield of 95%. The product structure was confirmed by mass spectrometry: MS (m / z): 280 (M+1) + .

[0058] (2) Preparation of 3,6-di(3-propionyl-1-yl)-9-isobutylcarbazole

[0059] Add 14g isobutylcarbazole, 20mL dichloromethane, 13.3g aluminum chloride to a 200mL four-necked flask, stir at 10°C, add dichloromethane propionyl chloride (10mL dichloromethane, 9.2g propionyl chloride) solution dropwise, add in about 1h, continue stirring for 2h, pour the reaction solution into 100mL water, separate the dichloromethane layer, wash with water until neutral, recrystallize from ethanol to obtain 16.6g white solid, yield 85%. The product structure was confirmed by nuclear magnetic resonance hydrogen spectrum and mass spectrum.

[0060] The H NMR spectrum data are as follows: 1 H-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).

[0061] MS (m / z): 392 (M+1) + .

[0062] Step (3) and Step (4): Preparation of 3,6-bis(1-oxime acetate-3-propionyl-1-yl)-9-isobutylcarbazole

[0063] To a 100mL four-necked flask, 3.9g 3,6-di(3-propionyl-1-yl)-9-isobutylcarbazole, 11.8g isoamyl nitrite, 10g 37% hydrochloric acid, and 20mL DMF were added, and the mixture was stirred at room temperature for 3h. The reaction was followed by liquid phase reaction. After the reaction was completed, the mixture was poured into water, and a solid was precipitated. The oximation intermediate was directly fed to the feed. 11g acetic anhydride and 20mL 4-dimethylaminopyridine were added as solvent. The mixture was stirred at room temperature for 2h. The reaction was followed by liquid phase reaction until the reaction was completed. The product solution was poured into water, and the product was precipitated. 4.5g of the product was obtained by filtration. The product was then added to a mixed solution of 5mL acetone and 5mL ethanol, heated to dissolve, and cooled to crystallize to obtain a light yellow solid product. The yield of the two-step product was 86%.

[0064] The product structure was confirmed by H NMR and mass spectrometry:

[0065] MS (m / z): 534 (M+1) + .

[0066] 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).

[0067] Example 2: With other conditions unchanged, the product obtained in Example 1 was recrystallized by adding 5 mL of acetone and 5 mL of methanol.

[0068] Example 3: With other conditions unchanged, the product obtained in Example 1 was recrystallized by adding 5 mL of acetone and 5 mL of isopropanol.

[0069] Comparative Example 1: With other conditions unchanged, the product obtained in Example 1 was added with 10 mL of acetone for recrystallization.

[0070] Comparative Example 2: With other conditions unchanged, the product obtained in Example 1 was added with 10 mL of ethanol for recrystallization.

[0071] Comparative Example 3: With other conditions unchanged, the product obtained in Example 1 was added with 10 mL of acetonitrile for recrystallization.

[0072] Comparative Example 4: With other conditions unchanged, the product obtained in Example 1 was added with 10 mL of methanol for recrystallization.

[0073] Comparative Example 5: Referring to the synthesis method of Example 1, the second step reaction raw material isooctylcarbazole is replaced with ethylcarbazole, and the post-treatment conditions remain unchanged.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] Performance Evaluation

[0078] The curing speed, odor, migration, solubility and other application properties of the photoinitiator represented by formula (I) of the present invention were evaluated by preparing a representative photocurable resin composition. The specific steps are as follows:

[0079] (1) Prepare a photocurable resin composition with the following composition:

[0080]

[0081] The acrylic acid ester copolymer is a copolymer of benzyl methacrylate / methacrylic acid / hydroxyethyl methacrylate (molar ratio 70 / 10 / 20) (Mv: 10000).

[0082] In the above composition, the photoinitiator is the product prepared in Examples 1-3 or the product in Comparative Examples 1-8.

[0083] (2) Curing speed

[0084] The above composition was stirred under a yellow light lamp, and the material was rolled onto a PET template to form a film, and dried at 90°C for 2 min to obtain a coating 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.

[0085] The coating was evaluated by the number of irradiation times required for the coating to cure into a cured film. The greater the number of irradiation times, the less ideal the curing speed.

[0086] (3) Migration

[0087] 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.

[0088] Using the GC-MS test method, take 5 g of the sample film prepared in the same way as above, cut it into a suitable size, put it into a headspace bottle for standby use, and use headspace injection to observe whether there is any overflow gas output (except carbon dioxide and its own solvent peak).

[0089] Instruments: Agilent 7890B gas chromatograph, Agilent 7697A headspace sampler, Agilent 7010B mass spectrometer;

[0090] Chromatographic column: Agilent HP-5ms column, vaporization temperature: 280°C, program temperature: 60°C-3min-20°C / min-280°C-10min;

[0091] Headspace conditions: heating box: 110°C, quantitative loop: 120°C, transfer line: 140°C, equilibrium time: 30 min;

[0092] Mass spectrometry conditions: ion source temperature: 280 °C, electron energy: 70 eV, scanning range (m / z): 30-400;

[0093] (5) Solubility

[0094] The solubility of the photoinitiator in the active diluent and the 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.

[0095] Table 1

[0096] Examples / Comparative Examples Curing speed Mobility Solubility Example 1 1 Not Detected >50％ Example 2 1 Not Detected >50％ Example 3 1 Not Detected >50％ Comparative Example 1 1 Not Detected ＜20％ Comparative Example 2 2 Not Detected ＜50％ Comparative Example 3 1 Not Detected ＜20％ Comparative Example 4 2 Not Detected ＜10％ Comparative Example 5 2 Not Detected ＜10％ Comparative Example 6 2 Not Detected ＜10％ Comparative Example 7 2 Detected ＜10％ Comparative Example 8 2 Detected ＜10％

[0097] It can be seen from Table 1 that the carbazole oxime ester initiator of the present invention has good curing effect and no migration after application, and the product obtained by the synthesis method of the present invention has excellent solubility.

[0098] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the carbazole oxime ester photoinitiator and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by 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 carbazole oxime ester photoinitiator, characterized in that: The carbazole oxime ester photoinitiator has a structure shown in the following formula I:

2. The method for preparing the carbazole oxime ester photoinitiator according to claim 1, characterized in that: The preparation method comprises 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, characterized in that: 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, characterized in that: 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, characterized in that: The photocurable resin composition comprises 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, characterized in that: The acrylate copolymer is selected from the group consisting of copolymers 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, characterized in that: The cured film is obtained by curing the photocurable resin composition according to claim 6 or 7.

9. An EL element, characterized in that: The EL element comprises the photocurable resin composition according to claim 6 or 7 or the cured film according to claim 8.

10. A display device, characterized in that: The display device comprises 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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