Preparation process of high-sensitivity oxime ester photopolymerization initiator

Abstract

The invention relates to a preparation process of a high-sensitivity oxime ester photopolymerization initiator, and belongs to the technical field of photosensitive materials. The preparation process of the high-sensitivity oxime ester photopolymerization initiator comprises the following steps: uniformly mixing a 2-nitrothiophene solution and an alkaline compound to obtain a mixed solution, then dropwise adding an isophthalonitrile solution into the mixed solution, and after dropwise adding is finished, carrying out mixed reaction for 12-15 hours to obtain an oxime compound; and finally reacting the oxime compound with acyl chloride to obtain the high-sensitivity oxime ester photopolymerization initiator. The optimal solvent and the alkaline catalyst for the reaction of the 2-nitrothiophene and the isophthalodiacetonitrile are screened out through a large number of experiments, and the yield of the intermediate oxime compound can be effectively improved. By screening the appropriate solvent, the acyl chloride solution can be ensured to move downwards under the action of gravity and be in better contact reaction with the oxime compound, so that the reaction yield is improved, side reaction is avoided, and the product purity is improved.

Description

Technical Field

[0001] The present invention relates to a preparation process of a high-sensitivity oxime ester photoinitiator, belonging to the technical field of photosensitive materials. Background Art

[0002] The ultraviolet curing technology is a process that uses ultraviolet light as the energy source to rapidly transform liquid materials into solids, and has been increasingly applied in industries such as postal and telecommunications, printing and packaging, electronics, and decoration. In the ultraviolet curing system, the photoinitiator plays a crucial role. It can be said that the core technology for expanding the range of ultraviolet curing products is the development of new photoinitiators.

[0003] Traditional photoinitiators can be divided into free radical polymerization photoinitiators and cationic polymerization photoinitiators according to different reaction mechanisms. With the development of technology, designing two-photon photoinitiators with large two-photon absorption cross-sections has become a new development direction. Oxime ester compounds have good light responsiveness. The N-O bond in the structure undergoes cleavage under light irradiation, and then rapidly decarboxylates to release carbon dioxide, generating free radical active species to initiate the polymerization reaction. The irreversible decarboxylation process can effectively solve the problems of reverse electron transfer and free radical inactivation.

[0004] Chinese patent document CN106478843B discloses a bis-oxime ester photoinitiator containing a thiophene ring. The presence of the thiophene ring and the bis-oxime ester group in the chemical structure of this bis-oxime ester photoinitiator makes the photoinitiator excellent in terms of storage stability, photosensitivity, developability, and pattern integrity. The chemical structure of this bis-oxime ester photoinitiator is as follows:

[0005] However, the photoinitiator prepared by the preparation method of the bis-oxime ester photoinitiator containing a thiophene ring disclosed in this patent document has a low yield, cannot be mass-produced, and cannot meet industrial applications. Summary of the Invention

[0006] The purpose of the present invention is to provide a preparation process of a high-sensitivity oxime ester photoinitiator to solve the problem of low yield in the current preparation of bis-oxime ester photoinitiators containing a thiophene ring with high photosensitivity.

[0007] The technical solution of the preparation process of the high-sensitivity oxime ester photoinitiator of the present invention is as follows: A preparation process of a high-sensitivity oxime ester photoinitiator, comprising the following steps: (1) Mix the 2-nitrothiophene solution and the basic compound to obtain a mixed solution. The 2-nitrothiophene solution consists of 2-nitrothiophene and a first solvent, and the first solvent consists of dioxane and 1,2-diethoxyethane with a mass ratio of 1:0.8 - 1; then dropwise add the isophthalonitrile solution to the mixed solution. After the addition is completed, carry out a mixed reaction for 12 - 15 h. Add hydrochloric acid to the reaction system to adjust the pH of the system to 5, and then purify the reaction product to obtain the oxime compound shown in Formula 1; the isophthalonitrile solution consists of isophthalonitrile and a second solvent, and the second solvent consists of tetrahydrofuran and dimethoxymethane with a mass ratio of 1:0.8 - 1;; the basic compound consists of lithium hydroxide and potassium tert-butoxide with a mass ratio of 2:2.5 - 3.

[0008] (2) Under nitrogen protection, in the dark, and at 0 - 5 °C, add a first acid-binding agent to the oxime compound solution, mix well, then dropwise add the acyl chloride solution. After the addition is completed, add a second acid-binding agent and carry out a mixed reaction for 2 - 4 h. Finally, purify the reaction product to obtain the oxime ester photoinitiator; the first acid-binding agent consists of tri-n-butylamine and diisopropylethylamine with a molar ratio of 2:1 - 1.2; the oxime compound solution consists of the oxime compound and a third solvent, and the third solvent consists of tetrahydrofuran and dimethoxymethane with a mass ratio of 2:1; the acyl chloride solution consists of an acyl chloride compound and a fourth solvent, and the fourth solvent consists of dioxane and 1,2-diethoxyethane with a mass ratio of 1:1 - 1.5; the second acid-binding agent consists of pyridine and triethylamine with a molar ratio of 1:1 - 1.2.

[0009] Preferably, for every 0.21 - 0.23 mol of 2-nitrothiophene, the volume of the first solvent used is 1000 - 1100 mL.

[0010] Preferably, for every 0.21 - 0.23 mol of 2-nitrothiophene, the mass of the basic compound used is 65 - 70 g.

[0011] Preferably, the molar ratio of 2-nitrothiophene to isophthalonitrile is (0.21 - 0.23):0.1.

[0012] Preferably, for every 0.1 mol of isophthalonitrile, the volume of the second solvent used is 500 - 550 mL.

[0013] Preferably, the purification method in step (1) is as follows: Rotavapor-concentrate the reaction product to obtain a concentrated solution, and then purify the concentrated solution by column chromatography. The eluent for column chromatography is a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 3:1. Then, rotavapor and vacuum-dry the liquid collected by column chromatography.

[0014] Preferably, the volume of the third solvent used for every 0.32 mmol of the oxime compound is 5 mL.

[0015] Preferably, the molar ratio of the oxime compound, the first acid-binding agent, the acyl chloride compound, and the second acid-binding agent is 0.32:(1~1.2):(1~1.3):(0.9~1.1).

[0016] Preferably, the volume of the fourth solvent used for every 1~1.3 mmol of the acyl chloride compound is 5 mL.

[0017] Preferably, the acyl chloride compound is p-trifluoromethylbenzenesulfonyl chloride, p-toluenesulfonyl chloride, p-methylbenzoyl chloride, p-methoxybenzoyl chloride, 2-thiopheneacetyl chloride, 2-pyrazinecarbonyl chloride, furfuryl chloride, 1-methyl-1H-pyrazole-5-carbonyl chloride, 2,2-bithiophene-5-carbonyl chloride, or carbazole-N-carbonyl chloride.

[0018] The beneficial technical effects of the present invention are as follows: (1) Through a large number of experiments, the present invention screens out the best solvent and basic catalyst for the reaction of 2-nitrothiophene and m-xylene dinitrile, which can effectively improve the yield of the intermediate oxime compound.

[0019] (2) Through a large number of experiments, the present invention screens out the best solvent for the reaction of the oxime compound and the acyl chloride. The oxime compound is dissolved in the mixed solvent of tetrahydrofuran and dimethoxymethane with a smaller density, and the acyl chloride is dissolved in the mixed solvent of dioxane and 1,2-diethoxyethane with a larger density. By dropping the acyl chloride solution into the oxime compound solution, it can ensure that the acyl chloride solution moves downward under the action of gravity, better contact and react with the oxime compound, improve the reaction yield, avoid side reactions, and improve the product purity.

[0020] (3) By adding different acid-binding agents to the reaction system of the oxime compound in batches, the first acid-binding agent added is composed of tri-n-butylamine and diisopropyl ethylamine with more branched chains, and the second acid-binding agent added is composed of pyridine and triethylamine with fewer branched chains. The two acid-binding agents added in different batches can cooperate to improve the acid-binding effect, thereby improving the reaction efficiency and product purity. Description of the Drawings

[0021] Figure 1 It is the 1H NMR spectrum of the oxime ester photoinitiator prepared in Example 2 of the present invention; Figure 2 It is the 1H NMR spectrum of the oxime ester photoinitiator prepared in Example 4 of the present invention. Detailed Embodiments

[0022] The following examples are intended to further illustrate the content of the present invention rather than limit the protection scope of the present invention.

[0023] Example 1: The preparation process of the high-sensitivity oxime ester photoinitiator in this example includes the following steps: (1) Dissolve 0.21 mol of 2-nitrothiophene in 1000 mL of the first solvent (the first solvent consists of dioxane and 1,2-diethoxyethane with a mass ratio of 1:0.8) to obtain a 2-nitrothiophene solution. Then add 65 g of the basic compound (the basic compound consists of lithium hydroxide and potassium tert-butoxide with a mass ratio of 2:2.5) to the 2-nitrothiophene solution, and then stir to fully dissolve the sodium hydroxide to obtain a mixed solution. Then, add dropwise the m-phthalonitrile solution (prepared by dissolving 0.1 mol of m-phthalonitrile in 500 mL of the second solvent, and the second solvent consists of tetrahydrofuran and dimethoxymethane with a mass ratio of 1:1) to the mixed solution. After the addition is completed, stir and react for 12 h. Add concentrated hydrochloric acid to the reacted system to adjust the pH of the system to 5, and then rotary evaporate and concentrate the reaction product at 50 °C to obtain a concentrated solution. Purify the concentrated solution by column chromatography. The eluent during column chromatography is a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 3:1. Then rotary evaporate and vacuum dry the liquid collected by column chromatography to obtain the oxime compound shown in Formula 1. The yield calculated based on m-phthalonitrile is 95%, and the purity is 99.6%.

[0024]

[0025] (2) Under nitrogen protection and light-shielded conditions, add 0.32 mmol of the oxime compound prepared in step (1) and 5 mL of the third solvent (the third solvent consists of tetrahydrofuran and dimethoxymethane with a mass ratio of 2:0.8) to the reaction flask. Adjust the temperature of the materials in the reaction flask to 0 °C, and then add the first acid-binding agent with a total molar amount of 1 mmol (the first acid-binding agent consists of tri-n-butylamine and diisopropyl ethylamine with a molar ratio of 2:1) to the reaction flask. After stirring evenly, add dropwise the acyl chloride solution. The acyl chloride solution is prepared by dissolving 1 mmol of the acyl chloride compound in 5 mL of the fourth solvent (the fourth solvent consists of dioxane and 1,2-diethoxyethane with a mass ratio of 1:1). The acyl chloride compound is p-trifluoromethylbenzenesulfonyl chloride. After the addition is completed, add the second acid-binding agent with a total molar amount of 0.9 mmol (the second acid-binding agent consists of pyridine and triethylamine with a molar ratio of 1:1) to the reaction flask, and then stir and react for 2 h. Then rotary evaporate and concentrate the reacted system at 50 °C to obtain a concentrated solution. Purify the concentrated solution by column chromatography. The eluent during column chromatography is dichloromethane. Then rotary evaporate and vacuum dry the liquid collected by column chromatography to obtain the oxime ester photoinitiator shown in Formula 2. The yield calculated based on the oxime compound is 97%, and the purity is 99.5%.

[0026]

[0027] Example 2: The preparation process of the high-sensitivity oxime ester photoinitiator in this example includes the following steps: (1) Dissolve 0.23 mol of 2-nitrothiophene in 1100 mL of the first solvent (the first solvent is composed of dioxane and 1,2-diethoxyethane with a mass ratio of 1:1) to obtain a 2-nitrothiophene solution. Then add 70 g of the basic compound (the basic compound is composed of lithium hydroxide and potassium tert-butoxide with a mass ratio of 2:3) to the 2-nitrothiophene solution, and then stir to fully dissolve sodium hydroxide to obtain a mixed solution. Then dropwise add the m-phthalodinitrile solution (prepared by dissolving 0.1 mol of m-phthalodinitrile in 550 mL of the second solvent, and the second solvent is composed of tetrahydrofuran and dimethoxymethane with a mass ratio of 1:0.8) into the mixed solution. After the dropping is completed, stir and react for 15 h. Add concentrated hydrochloric acid to the reacted system to adjust the pH of the system to 5. Then rotary evaporate and concentrate the reaction product at 50 °C to obtain a concentrated solution. Purify the concentrated solution by column chromatography. The eluent during column chromatography is a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 3:1. Then rotary evaporate and vacuum dry the liquid collected by column chromatography to obtain the oxime compound shown in Formula 1. The yield calculated based on m-phthalodinitrile is 99%, and the purity is 99.8%.

[0028]

[0029] (2) Under nitrogen protection and in the dark, add 0.32 mmol of the oxime compound prepared in step (1) and 5 mL of the third solvent (the third solvent is composed of tetrahydrofuran and dimethoxymethane with a mass ratio of 2:1) to the reaction flask. Adjust the temperature of the materials in the reaction flask to 0 - 5 °C. Then add the first acid-binding agent with a total molar amount of 1.2 mmol (the first acid-binding agent is composed of tri-n-butylamine and diisopropyl ethylamine with a molar ratio of 2:1.2) to the reaction flask. After stirring evenly, dropwise add the acyl chloride solution. The acyl chloride solution is prepared by dissolving 1.3 mmol of the acyl chloride compound in 5 mL of the fourth solvent (the fourth solvent is composed of dioxane and 1,2-diethoxyethane with a mass ratio of 1:1.5). The acyl chloride compound is 2-thiopheneacetyl chloride. After the dropping is completed, add the second acid-binding agent with a total molar amount of 1.1 mmol (the second acid-binding agent is composed of pyridine and triethylamine with a molar ratio of 1:1.2) to the reaction flask, and then stir and react for 4 h. Then rotary evaporate and concentrate the reacted system at 50 °C to obtain a concentrated solution. Purify the concentrated solution by column chromatography. The eluent during column chromatography is dichloromethane. Then rotary evaporate and vacuum dry the liquid collected by column chromatography to obtain the oxime ester photoinitiator shown in Formula 3 (the nuclear magnetic hydrogen spectrum of the oxime ester photoinitiator is as Figure 1 shown). The yield calculated based on the oxime compound is 98%, and the purity is 99.9%.

[0030]

[0031] Example 3: The preparation process of the high-sensitivity oxime ester photoinitiator of this example includes the following steps: (1) Dissolve 0.22 mol of 2-nitrothiophene in 1050 mL of the first solvent (the first solvent consists of dioxane and 1,2-diethoxyethane with a mass ratio of 1:0.9) to obtain a 2-nitrothiophene solution. Then add 68 g of the basic compound (the basic compound consists of lithium hydroxide and potassium tert-butoxide with a mass ratio of 2:2.8) to the 2-nitrothiophene solution, and then stir to fully dissolve sodium hydroxide to obtain a mixed solution. Then drip the m-phthalodinitrile solution (prepared by dissolving 0.1 mol of m-phthalodinitrile in 520 mL of the second solvent, and the second solvent consists of tetrahydrofuran and dimethoxymethane with a mass ratio of 1:0.9) into the mixed solution. After the dripping is completed, stir and react for 13 h. Add concentrated hydrochloric acid to the reacted system to adjust the pH of the system to 5. Then rotary evaporate and concentrate the reaction product at 50 °C to obtain a concentrated solution. Purify the concentrated solution by column chromatography. The eluent during column chromatography is a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 3:1. Then rotary evaporate and vacuum dry the liquid collected by column chromatography to obtain the oxime compound shown in Formula 1. The yield calculated based on m-phthalodinitrile is 98%, and the purity is 99.9%.

[0032]

[0033] (2) Under nitrogen protection and light-shielded conditions, add 0.32 mmol of the oxime compound prepared in step (1) and 5 mL of the third solvent (the third solvent consists of tetrahydrofuran and dimethoxymethane with a mass ratio of 2:0.9) to the reaction flask. Adjust the temperature of the materials in the reaction flask to 2 °C, and then add the first acid-binding agent with a total molar amount of 1.1 mmol (the first acid-binding agent consists of tri-n-butylamine and diisopropyl ethylamine with a molar ratio of 2:1.1) to the reaction flask. After stirring evenly, drip the acyl chloride solution. The acyl chloride solution is prepared by dissolving 1.2 mmol of the acyl chloride compound in 5 mL of the fourth solvent (the fourth solvent consists of dioxane and 1,2-diethoxyethane with a mass ratio of 1:1.3). The acyl chloride compound is 2,2'-bithiophene-5-carbonyl chloride. After the dripping is completed, add the second acid-binding agent with a total molar amount of 1.0 mmol (the second acid-binding agent consists of pyridine and triethylamine with a molar ratio of 1:1.1) to the reaction flask, and then stir and react for 3 h. Then rotary evaporate and concentrate the reacted system at 50 °C to obtain a concentrated solution. Purify the concentrated solution by column chromatography. The eluent during column chromatography is dichloromethane. Then rotary evaporate and vacuum dry the liquid collected by column chromatography to obtain the oxime ester photoinitiator shown in Formula 2. The yield calculated based on the oxime compound is 99%, and the purity is 99.7%.

[0034]

[0035] Example 4: The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this example and that in Example 3 lies only in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this example, is replaced with 2-pyrazinecarbonyl chloride. The oxime ester photoinitiator shown in Formula 5 is prepared in this example (the 1H NMR spectrum of the oxime ester photoinitiator is as shown in Figure 2 ), and the yield calculated based on the oxime compound is 98%, and the purity is 99.9%.

[0036]

[0037] Example 5: The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this example and that in Example 3 lies only in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this example, is replaced with furan carbonyl chloride. The oxime ester photoinitiator shown in Formula 6 is prepared in this example, and the yield calculated based on the oxime compound is 99%, and the purity is 99.8%.

[0038]

[0039] Example 6: The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this example and that in Example 3 lies only in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this example, is replaced with 1-methyl-1H-pyrazole-5-carbonyl chloride. The oxime ester photoinitiator shown in Formula 7 is prepared in this example, and the yield calculated based on the oxime compound is 98%, and the purity is 99.7%.

[0040]

[0041] Example 7: The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this example and that in Example 3 lies only in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this example, is replaced with carbazole-N-carbonyl chloride. The oxime ester photoinitiator shown in Formula 8 is prepared in this example, and the yield calculated based on the oxime compound is 98%, and the purity is 99.4%.

[0042]

[0043] Example 8: The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this example and that in Example 3 is only that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this example, is replaced by p-toluenesulfonyl chloride. The oxime ester photoinitiator shown in Formula 8 is prepared in this example, and the yield calculated based on the oxime compound is 99%, and the purity is 99.7%.

[0044] Example 9: The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this example and that in Example 3 is only that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this example, is replaced by p-methoxybenzoyl chloride. The oxime ester photoinitiator shown in Formula 8 is prepared in this example, and the yield calculated based on the oxime compound is 98%, and the purity is 99.8%.

[0045] Example 10: The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this example and that in Example 3 is only that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this example, is replaced by p-tert-butylbenzoyl chloride. The oxime ester photoinitiator shown in Formula 8 is prepared in this example, and the yield calculated based on the oxime compound is 99%, and the purity is 99.9%.

[0046] Comparative Example 1 The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example and that in Example 3 is only that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first solvent is composed of dioxane and 1,2-dimethoxyethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 37%, and the purity is 95.1%.

[0047] Comparative Example 2 The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example and that in Example 3 is only that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first solvent is composed of dioxane and diethoxymethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 45%, and the purity is 96.2%.

[0048] Comparative Example 3 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first solvent is composed of dioxane and dimethoxymethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 39%, and the purity is 97.2%.

[0049] Comparative Example 4 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first solvent is composed of tetrahydrofuran and 1,2-diethoxyethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 41%, and the purity is 95.4%.

[0050] Comparative Example 5 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first solvent is composed of 1,2-dimethoxyethane and 1,2-diethoxyethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 35%, and the purity is 96.5%.

[0051] Comparative Example 6 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first solvent is composed of diethoxymethane and 1,2-diethoxyethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 39%, and the purity is 98.3%.

[0052] Comparative Example 7 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first solvent is composed of dimethoxymethane and 1,2-diethoxyethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 43%, and the purity is 97.3%.

[0053] Comparative Example 8 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example differs from that of the high-sensitivity oxime ester photoinitiator in Example 3 only in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the basic compound consists of sodium hydroxide and potassium tert-butoxide with a mass ratio of 2:2.8. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 46%, and the purity is 98.3%.

[0054] Comparative Example 9 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example differs from that of the high-sensitivity oxime ester photoinitiator in Example 3 only in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the basic compound consists of potassium hydroxide and potassium tert-butoxide with a mass ratio of 2:2.8. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 34%, and the purity is 97.5%.

[0055] Comparative Example 10 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example differs from that of the high-sensitivity oxime ester photoinitiator in Example 3 only in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the basic compound consists of lithium hydroxide and sodium tert-butoxide with a mass ratio of 2:2.8. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 32%, and the purity is 95.8%.

[0056] Comparative Example 11 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example differs from that of the high-sensitivity oxime ester photoinitiator in Example 3 only in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the basic compound consists of lithium hydroxide and lithium tert-butoxide with a mass ratio of 2:2.8. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 40%, and the purity is 96.2%.

[0057] Comparative Example 12 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example differs from that of the high-sensitivity oxime ester photoinitiator in Example 3 only in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second solvent consists of dioxane and dimethoxymethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalonitrile is 38%, and the purity is 97.1%.

[0058] Comparative Example 13 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second solvent is composed of 1,2-dimethoxyethane and dimethoxymethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phenylenediacetonitrile is 41%, and the purity is 98.3%.

[0059] Comparative Example 14 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second solvent is composed of 1,2-diethoxyethane and dimethoxymethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phenylenediacetonitrile is 46%, and the purity is 95.8%.

[0060] Comparative Example 15 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second solvent is composed of diethoxymethane and dimethoxymethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phenylenediacetonitrile is 43%, and the purity is 96.2%.

[0061] Comparative Example 16 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second solvent is composed of tetrahydrofuran and 1,2-dimethoxyethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phenylenediacetonitrile is 35%, and the purity is 98.1%.

[0062] Comparative Example 17 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second solvent is composed of tetrahydrofuran and 1,2-diethoxyethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phenylenediacetonitrile is 42%, and the purity is 95.9%.

[0063] Comparative Example 18 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second solvent consists of tetrahydrofuran and diethoxymethane with a mass ratio of 1:0.9. The yield of the oxime compound prepared in this comparative example calculated based on m-phthalodinitrile is 48%, and the purity is 96.8%.

[0064] Comparative Example 19 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the third solvent consists of dioxane and dimethoxymethane with a mass ratio of 2:0.9. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 41%, and the purity is 95.9%.

[0065] Comparative Example 20 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the third solvent consists of tetrahydrofuran and 1,2-dimethoxyethane with a mass ratio of 2:0.9. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 39%, and the purity is 96.3%.

[0066] Comparative Example 21 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the third solvent consists of tetrahydrofuran and 1,2-diethoxyethane with a mass ratio of 2:0.9. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 43%, and the purity is 97.3%.

[0067] Comparative Example 22 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the third solvent consists of tetrahydrofuran and diethoxymethane with a mass ratio of 2:0.9. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 45%, and the purity is 96.1%.

[0068] Comparative Example 23 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first acid-binding agent consists of triethylamine and diisopropylethylamine with a molar ratio of 2:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 37%, and the purity is 98.4%.

[0069] Comparative Example 24 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first acid-binding agent consists of tri-n-pentylamine and diisopropylethylamine with a molar ratio of 2:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 46%, and the purity is 97.3%.

[0070] Comparative Example 25 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first acid-binding agent consists of tri-n-butylamine and N,N-dimethylethylamine with a molar ratio of 2:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 42%, and the purity is 98.9%.

[0071] Comparative Example 26 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the first acid-binding agent consists of tri-n-butylamine and dimethylbenzylamine with a molar ratio of 2:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 41%, and the purity is 97.5%.

[0072] Comparative Example 27 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the fourth solvent consists of tetrahydrofuran and 1,2-diethoxyethane with a mass ratio of 1:1.3. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 45%, and the purity is 96.3%.

[0073] Comparative Example 28 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the fourth solvent consists of dioxane and 1,2-dimethoxyethane with a mass ratio of 1:1.3. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 38%, and the purity is 97.1%.

[0074] Comparative Example 29 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the fourth solvent consists of dioxane and diethoxymethane with a mass ratio of 1:1.3. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 46%, and the purity is 95.7%.

[0075] Comparative Example 30 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the fourth solvent consists of dioxane and dimethoxymethane with a mass ratio of 1:1.3. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 49%, and the purity is 96.2%.

[0076] Comparative Example 31 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second acid-binding agent consists of pyridine and tri-n-butylamine with a molar ratio of 1:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 44%, and the purity is 96.2%.

[0077] Comparative Example 32 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second acid-binding agent consists of pyridine and diisopropylethylamine with a molar ratio of 1:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 41%, and the purity is 97.4%.

[0078] Comparative Example 33 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second acid-binding agent consists of pyridine and tri-n-pentylamine with a molar ratio of 1:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 46%, and the purity is 95.9%.

[0079] Comparative Example 34 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second acid-binding agent consists of pyridine and N,N-dimethylethylamine with a molar ratio of 1:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 45%, and the purity is 98.1%.

[0080] Comparative Example 35 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second acid-binding agent consists of pyridine and dimethylbenzylamine with a molar ratio of 1:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 43%, and the purity is 97.5%.

[0081] Comparative Example 36 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second acid-binding agent consists of N,N-dimethylethylamine and triethylamine with a molar ratio of 1:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 41%, and the purity is 97.2%.

[0082] Comparative Example 37 The preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example is only different from that of the high-sensitivity oxime ester photoinitiator in Example 3 in that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second acid-binding agent consists of dimethylbenzylamine and triethylamine with a molar ratio of 1:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 45%, and the purity is 98.0%.

[0083] Comparative Example 38 The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example and that of the high-sensitivity oxime ester photoinitiator in Example 3 is only that in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator in this comparative example, the second acid-binding agent consists of diisopropylethylamine and triethylamine with a molar ratio of 1:1.1. The yield of the oxime ester photoinitiator prepared in this comparative example calculated based on the oxime compound is 36%, and the purity is 97.2%.

[0084] The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in other comparative examples and that of the high-sensitivity oxime ester photoinitiator in Example 3 is only that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in Example 3, the first solvent is replaced with methanol, dioxane, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, diethoxymethane or dimethoxymethane. The yields of the prepared oxime compounds calculated based on m-phthalodinitrile are 39%, 41%, 43%, 37%, 42%, 35%, 45% respectively in sequence.

[0085] The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in other comparative examples and that of the high-sensitivity oxime ester photoinitiator in Example 3 is only that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in Example 3, the basic compound is replaced with sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, sodium tert-butoxide, potassium tert-butoxide, lithium tert-butoxide, sodium hexamethyldisilazide, potassium hexamethyldisilazide or lithium hexamethyldisilazide. The yields of the prepared oxime compounds calculated based on m-phthalodinitrile are 42%, 41%, 43%, 38%, 40%, 39%, 41%, 35%, 43%, 41%, 38%, 42%, 41% respectively in sequence.

[0086] The difference between the preparation process of the high-sensitivity oxime ester photoinitiator in other comparative examples and that of the high-sensitivity oxime ester photoinitiator in Example 3 is only that in step (1) of the preparation process of the high-sensitivity oxime ester photoinitiator in Example 3, the second solvent is replaced with methanol, dioxane, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, diethoxymethane or dimethoxymethane. The yields of the prepared oxime compounds calculated based on m-phthalodinitrile are 37%, 44%, 41%, 39%, 42%, 37%, 44% respectively in sequence.

[0087] The preparation processes of the high-sensitivity oxime ester photoinitiators of other comparative examples and the preparation process of the high-sensitivity oxime ester photoinitiator of Example 3 only differ in that the third solvent in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator of Example 3 is replaced with dioxane, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, diethoxymethane or dimethoxymethane. The yields of the prepared oxime ester photoinitiators calculated based on the oxime compounds are 41%, 38%, 35%, 39%, 42%, and 45% respectively.

[0088] The preparation processes of the high-sensitivity oxime ester photoinitiators of other comparative examples and the preparation process of the high-sensitivity oxime ester photoinitiator of Example 3 only differ in that the first acid-binding agent in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator of Example 3 is replaced with pyridine, triethylamine, tri-n-butylamine, diisopropylethylamine, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, tri-n-pentylamine, N,N-dimethylethylamine or dimethylbenzylamine. The yields of the prepared oxime ester photoinitiators calculated based on the oxime compounds are 45%, 42%, 39%, 43%, 40%, 47%, 42%, 35%, 31%, 37%, and 48% respectively.

[0089] The preparation processes of the high-sensitivity oxime ester photoinitiators of other comparative examples and the preparation process of the high-sensitivity oxime ester photoinitiator of Example 3 only differ in that the fourth solvent in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator of Example 3 is replaced with dioxane, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, diethoxymethane or dimethoxymethane. The yields of the prepared oxime ester photoinitiators calculated based on the oxime compounds are 38%, 41%, 45%, 41%, 43%, and 44% respectively.

[0090] The preparation processes of the high-sensitivity oxime ester photoinitiators of other comparative examples and the preparation process of the high-sensitivity oxime ester photoinitiator of Example 3 only differ in that the second acid-binding agent in step (2) of the preparation process of the high-sensitivity oxime ester photoinitiator of Example 3 is replaced with pyridine, triethylamine, tri-n-butylamine, diisopropylethylamine, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, tri-n-pentylamine, N,N-dimethylethylamine or dimethylbenzylamine. The yields of the prepared oxime ester photoinitiators calculated based on the oxime compounds are 41%, 36%, 37%, 41%, 44%, 42%, 45%, 39%, 34%, 33%, and 42% respectively.

[0091] Effect Example The oxime ester photoinitiator and the polymerizable monomer were stirred evenly until the initiator was completely dissolved. The mass of the oxime ester photoinitiator was 1.5% of the mass of the polymerizable monomer. The polymerizable monomer was composed of triethylene glycol divinyl ether and tetra(ethylene glycol) divinyl ether with a mass ratio of 1:2. Then it was coated on a glass plate with a coating thickness of 30 μm and irradiated with an ultraviolet lamp (wavelength 385 nm or 410 nm) for 2 min. The double bond conversion rate of the polymerizable monomer was determined by infrared test analysis, and the results are shown in Table 1.

[0092] Table 1 Photo-conversion rates of different polymerizable monomers by different oxime ester photoinitiators under different light wavelengths

[0093] As can be seen from Table 1, the oxime ester photoinitiator prepared in the present invention has a high photoinitiation efficiency for the polymerizable monomer at different wavelengths, has high photosensitivity, and can effectively improve the conversion rate of the polymerizable monomer.

Claims

1. A process for preparing a high-sensitivity oxime ester photopolymerization initiator, characterized in that: The following steps are involved: (1) Mixing a 2-nitrothiophene solution and an alkaline compound to obtain a mixed solution, wherein the 2-nitrothiophene solution is composed of 2-nitrothiophene and a first solvent, wherein the first solvent is composed of dioxane and 1,2-diethoxyethane in a mass ratio of 1:0.8~1; then adding the isophthalic diacetonitrile solution dropwise to the mixed solution, after the addition is completed, mixing and reacting for 12~15 hours, adding hydrochloric acid to the system after the reaction, adjusting the pH of the system to 5, and then purifying the reaction product to obtain an oxime compound as shown in Formula 1; the isophthalic diacetonitrile solution is composed of isophthalic diacetonitrile and a second solvent, wherein the second solvent is composed of tetrahydrofuran and dimethoxymethane in a mass ratio of 1:0.8~1; the alkaline compound is composed of lithium hydroxide and potassium tert-butoxide in a mass ratio of 2:2.5~3; (2) Under nitrogen protection, light avoidance and 0-5°C, a first acid binding agent is added to an oxime compound solution, mixed, and then an acyl chloride solution is added dropwise. After the addition is completed, a second acid binding agent is added, mixed and reacted for 2-4 hours, and finally the reaction product is purified to obtain an oxime ester photopolymerization initiator; the first acid binding agent is composed of tri-n-butylamine and diisopropylethylamine in a molar ratio of 2:1-1.2; the oxime compound solution is composed of an oxime compound and a third solvent, and the third solvent is composed of tetrahydrofuran and dimethoxymethane in a mass ratio of 2:1; the acyl chloride solution is composed of an acyl chloride compound and a fourth solvent, and the fourth solvent is composed of dioxane and 1,2-diethoxyethane in a mass ratio of 1:1-1.5; the second acid binding agent is composed of pyridine and triethylamine in a molar ratio of 1:1-1.

2.

2. The process for preparing the high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The volume of the first solvent used for every 0.21-0.23 mol of 2-nitrothiophene is 1000-1100 mL.

3. The process for preparing the high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The mass of the basic compound used for every 0.21-0.23 mol of 2-nitrothiophene is 65-70 g.

4. The process for preparing the high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The molar ratio of 2-nitrothiophene to isophthalonitrile is (0.21~0.23):0.

1.

5. The process for preparing the high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The volume of the second solvent used for every 0.1 mol of isophthalic acid cyanide is 500-550 mL.

6. The process for preparing the high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The purification method in step (1) is as follows: the reaction product is concentrated by rotary evaporation to obtain a concentrated solution, and then the concentrated solution is purified by column chromatography, wherein the eluent during the column chromatography purification is a mixed solvent of n-hexane and ethyl acetate in a volume ratio of 3:1, and then the liquid collected by column chromatography purification is rotary evaporated and vacuum dried.

7. The process for preparing the high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The volume of the third solvent used for every 0.32 mmol of the oxime compound is 5 mL.

8. The process for preparing the high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The molar ratio of the oxime compound, the first acid binding agent, the acyl chloride compound and the second acid binding agent is 0.32:(1-1.2):(1-1.3):(0.9-1.1).

9. The process for preparing a high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The volume of the fourth solvent used for every 1-1.3 mmol of the acyl chloride compound is 5 mL.

10. The process for preparing a high-sensitivity oxime ester photopolymerization initiator according to claim 1, characterized in that: The acyl chloride compound is p-trifluoromethylbenzenesulfonyl chloride, p-toluenesulfonyl chloride, p-toluoyl chloride, p-methoxybenzoyl chloride, 2-thiopheneacetyl chloride, 2-pyrazinecarbonyl chloride, furoyl chloride, 1-methyl-1H-pyrazole-5-carbonyl chloride, 2,2-bithiophene-5-carbonyl chloride or carbazole-N-carbonyl chloride.

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