WO2024021979A1

WO2024021979A1 - Oxime ester photoinitiator, preparation method therefor and use thereof

Info

Publication number: WO2024021979A1
Application number: PCT/CN2023/103405
Authority: WO
Inventors: 钱彬
Original assignee: 常州强力电子新材料股份有限公司; 常州强力先端电子材料有限公司
Priority date: 2022-07-27
Filing date: 2023-06-28
Publication date: 2024-02-01
Also published as: CN117510396A

Abstract

The present application provides an oxime ester photoinitiator, and a preparation method therefor and the use thereof. The oxime ester photoinitiator has a structure as shown in general formula (I), wherein R1 and R2 are each independently selected from a substituted or unsubstituted C1-C20 alkyl, a substituted or unsubstituted C3-C20 cycloalkyl, a substituted or unsubstituted C6-C20 aryl, a substituted or unsubstituted C4-C20 heteroaryl, and a substituted or unsubstituted C3-C20 cycloaliphatic heterocyclic group; m is 1 or 0, n is 1 or 0, x is 1 or 0, y is 1 or 0, and z is 1 or 0. The oxime ester photoinitiator of the present application has a diketone oxime ester structure and asymmetric substituents, and has a delocalization structure. Compared with an existing similar photoinitiator, the oxime ester photoinitiator has significantly improved solubility, can take both high sensitivity and low yellowing into consideration when applied to a photocurable composition, and has good application prospects.

Description

Oxime ester photoinitiator, its preparation method and application

This application claims priority from Chinese patent application 202210893632.X with a filing date of July 27, 2022. This application cites the full text of the above-mentioned Chinese patent application.

Technical field

The present application relates to the technical field of organic chemistry, specifically, to an oxime ester photoinitiator, its preparation method and application.

Background technique

Oxime ester photoinitiators are widely used in the production of various photoresists due to their relatively excellent performance. Among them, oxime ester initiators with carbazole as the parent group are an important type of oxime ester photoinitiators. Because of its relatively high sensitivity, it has attracted widespread attention from those skilled in the art. High-sensitivity oxime ester initiators have always been the goal pursued by industry technicians. The patents CN103833872A, CN103819583A and CN110066225A respectively modified the molecular structure and red-shifted the absorption wavelength to improve the sensitivity, thereby obtaining high sensitivity under LED curing conditions. Initiator.

However, this type of initiator is difficult to apply in RGB color photoresists and transparent coatings due to yellowing problems. Patents such as patents CN114369178A, CN104910053A and application number 202111363587.9 have reduced the yellowing coefficient to a certain extent, but their sensitivity is still It is not ideal, and some parts of the structure are relatively complex, making it difficult to apply industrially. In order to improve the transmittance of transparent photoresist and the color saturation of color photoresist, the photoinitiator used needs to have lower yellowness and higher sensitivity. Therefore, it is still necessary to develop higher sensitivity and lower New photoinitiator products for yellowing.

Contents of the invention

The main purpose of this application is to provide an oxime ester photoinitiator, its preparation method and application, so as to solve the problem that photoinitiators in the prior art cannot achieve both high sensitivity and low yellowing.

In order to achieve the above objects, according to one aspect of the present application, an oxime ester photoinitiator is provided, having a structure represented by general formula (I):

General formula (I), wherein R ₁ and R ₂ are each independently selected from substituted or unsubstituted C ₁ to C ₂₀ alkyl, substituted or unsubstituted C ₃ to C ₂₀ cycloalkyl, substituted or unsubstituted Substituted C ₆ to C ₂₀ aryl group, substituted or unsubstituted C ₄ to C ₂₀ heteroaryl group, substituted or unsubstituted C ₃ to C ₂₀ alicyclic heterocyclic group; m is 1 or 0, n is 1 or 0, x is 1 or 0, y is 1 or 0, z is 1 or 0.

Further, in the substituted C ₁ to C ₂₀ alkyl group, the substituent is selected from the C ₃ to C ₁₂ cycloalkyl group; optionally, in the substituted or unsubstituted C ₁ to C ₂₀ alkyl group, at least one -CH ₂ - is substituted by -O- or -S-; in the substituted C ₃ ~ C ₂₀ cycloalkyl group, the substituent is selected from C ₁ ~ C ₁₀ linear or branched alkyl group; the substituted C ₆ ~ In the C ₂₀ aryl group, the substituent is selected from C ₁ to C ₆ linear or branched alkyl group, C ₁ to C ₁₀ linear or branched alkoxy group, C ₁ to C ₁₀ linear or branched alkoxy group. One or more of alkylthio groups, C ₁ to C ₈ linear or branched acyl groups, C ₁ to C ₈ linear or branched acyloxy groups, halogen atoms, cyano groups or nitro groups; substitution In the C ₄ to C ₂₀ heteroaryl group, the substituent is selected from C ₁ to C ₈ linear or branched alkyl group; in the substituted C ₃ to C ₂₀ alicyclic heterocyclic group, the substituent is selected from C ₁ to C ₆ linear or branched alkyl group.

Further, R ₁ and R ₂ are each independently selected from a C ₁ to C ₂₀ alkyl group or a C ₆ to C ₂₀ aryl group; preferably, R ₁ and R ₂ are each independently selected from a methyl group, an ethyl group or a C 20 alkyl group. phenyl.

Further, the oxime ester photoinitiator has a structure shown in any one of the structural formulas (1) to (13):

Further, the oxime ester photoinitiator is

Further, the preparation method includes the following steps: step S1, carbazole with raw material A Carry out substitution reaction to obtain intermediate a Step S2, combine intermediate a and raw material B Carry out the first Friedel-Crafts reaction to obtain intermediate b Step S3, combine intermediate b and raw material C Carry out the second Friedel-Crafts reaction to obtain intermediate c Step S4, react intermediate c with nitrite and/or nitrite ester oximation reaction to obtain intermediate d Step S5, perform an esterification reaction between intermediate d and acid anhydride and/or acid chloride to obtain an oxime ester photoinitiator Among them, X is F, Cl, Br or I, m is 1 or 0, n is 1 or 0, x is 1 or 0, y is 1 or 0, and z is 1 or 0.

Further, in step S1, the substitution reaction is carried out under alkaline conditions, and the base is potassium hydroxide and/or sodium hydroxide; and/or, in step S2, the first Friedel-Crafts reaction is carried out under the catalysis of aluminum trichloride. , the solvent of the first Friedel-Crafts reaction is methylene chloride and/or dichloroethane; and/or, in step S3, the second Friedel-Crafts reaction is carried out under the catalysis of aluminum trichloride, and the solvent of the second Friedel-Crafts reaction is be methylene chloride and/or dichloroethane; and/or, in step S4, the nitrite is sodium nitrite and/or potassium nitrite, and the nitrite ester is ethyl nitrite, isoamyl nitrite and nitrite. One or more isooctyl nitrates; preferably, the oximation reaction is carried out under acidic conditions, the acid is concentrated hydrochloric acid and/or halogenated carboxylic acid, the halogenated carboxylic acid is chloroacetic acid or bromoacetic acid, the oximation reaction is The solvent is one or more of ethyl acetate, tetrahydrofuran and dichloromethane; and/or, in step S5, the acid anhydride is acetic anhydride and/or benzoic anhydride, and the acid chloride is one of acetyl chloride, propionyl chloride and benzoyl chloride. One or more; preferably, the esterification reaction is carried out under alkaline conditions, and the base is one or more of triethylamine, diisopropylethylamine and 4-dimethylaminopyridine.

Further, in step S1, the molar ratio of raw material A to carbazole is (1~1.1):1; preferably, the reaction temperature of the substitution reaction is 50~100°C; more preferably, the reaction temperature of the substitution reaction is 50~100°C. 80°C; and/or, in step S2, the molar ratio of raw material B to intermediate a is (1~1.1):1; preferably, the reaction temperature of the first Friedel-Crafts reaction is -10~10°C; more preferably, The reaction temperature of the first Friedel-Crafts reaction is 0-5°C; and/or, in step S3, the molar ratio of raw material C to intermediate b is (1-1.1):1; preferably, the reaction temperature of the second Friedel-Crafts reaction is is -10~10°C; more preferably, the reaction temperature of the second Friedel-Crafts reaction is 0~5°C; and/or, in step S4, the molar ratio of nitrite and/or nitrite ester to intermediate c is ( 2～3.5):1; Preferably, the reaction temperature of the oximation reaction is 0～30°C; More preferably, the reaction temperature of the oximation reaction is 20～25°C; and/or, step S5, acid anhydride and/or acid chloride The molar ratio to intermediate d is (2-2.8):1; preferably, the reaction temperature of the esterification reaction is 0-30°C; more preferably, the reaction temperature of the esterification reaction is 20-25°C.

According to another aspect of the present application, the application of the oxime ester photoinitiator of the present application in photoresist is provided.

According to another aspect of the present application, a photocurable composition is provided, including a photoinitiator, which is the oxime ester photoinitiator of the present application; preferably, in parts by weight, the photocurable composition includes 800 to 1000 parts of solvent, 100-300 parts of acrylate copolymer, 50-150 parts of dipentaerythritol hexaacrylate and 3-10 parts of oxime ester photoinitiator.

The oxime ester photoinitiator of the present application has a diketoxime ester structure, which greatly improves the sensitivity. It also improves the solubility by setting asymmetric substituents and limiting specific group types; moreover, its delocalized structure can reduce Fluctuation of groups improves yellowing properties. Compared with existing similar photoinitiators, the oxime ester photoinitiator of the present application has significantly improved solubility, excellent application performance in photocurable compositions, and not only has low yellowing properties when applied to photocurable compositions It has high sensitivity and can take into account both high sensitivity and low yellowing. In addition, the oxime ester photoinitiator also has the advantages of easy synthesis and low cost, and has good application prospects in the field of photocuring.

Detailed ways

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present application will be described in detail below with reference to examples.

Terminology explanation:

Concentrated hydrochloric acid: aqueous hydrochloric acid solution with a mass concentration of 38% and above.

As mentioned in the background of this application, there is a problem in the prior art that photoinitiators cannot achieve both high sensitivity and low yellowing. In order to solve the above problems, in a typical embodiment of the present application, an oxime ester photoinitiator is provided, having a structure represented by general formula (I):

The oxime ester photoinitiator of the present application has a diketoxime ester structure, which greatly improves the sensitivity; by setting asymmetric substituents and limiting specific group types, the solubility is improved; and its delocalized structure can reduce the number of radicals. The group fluctuates and improves the yellowing performance. Compared with existing similar photoinitiators, the oxime ester photoinitiator of the present application has significantly improved solubility. It has excellent application performance in photocurable compositions. When applied to photocurable compositions, it not only has the characteristics of low yellowing, but also has high sensitivity, and can achieve both high sensitivity and low yellowing. In addition, the oxime ester photoinitiator also has the advantages of easy synthesis and low cost, and has good application prospects in the field of photocuring.

Specifically, in a preferred embodiment, in the substituted C ₁ to C ₂₀ alkyl group, the substituent is selected from the group consisting of C ₃ to C ₁₂ cycloalkyl groups; optionally, substituted or unsubstituted C ₁ to In the C ₂₀ alkyl group, at least one -CH ₂ - is substituted by -O- or -S-; in the substituted C ₃ to C ₂₀ cycloalkyl group, the substituent is selected from C ₁ to C ₁₀ straight chain or branched Alkyl group; in the substituted C ₆ to C ₂₀ aryl group, the substituent is selected from C ₁ to C ₆ linear or branched alkyl group, C ₁ to C ₁₀ linear or branched alkoxy group, C ₁ to C ₁₀ linear or branched alkylthio group, C ₁ to C ₈ linear or branched acyl group, C ₁ to C ₈ linear or branched acyloxy group, halogen atom, cyano group or nitro group One or more of them; in the substituted C ₄ to C ₂₀ heteroaryl group, the substituent is selected from the C ₁ to C ₈ linear or branched alkyl group; the substituted C ₃ to C ₂₀ alicyclic group In the heterocyclic group, the substituent is selected from C ₁ to C ₆ linear or branched alkyl groups, and the oxime ester photoinitiator having the above substituents has better solubility.

In a preferred embodiment, R ₁ and R ₂ are independently selected from C ₁ to C ₂₀ alkyl groups or C ₆ to C ₂₀ aryl groups; preferably, R ₁ and R ₂ are independently selected from Methyl, ethyl or phenyl. The oxime ester photoinitiator with the above substituents has higher sensitivity and lower yellowing property.

Preferably, the oxime ester photoinitiator has a structure shown in any one of the structural formulas (1) to (13), and has better overall performance:

More preferably, the oxime ester photoinitiator is Most preferably, the oxime ester photoinitiator is The oxime ester photoinitiator with the above structure has greater sensitivity and better solubility. The substituents and delocalized structure can reduce group fluctuations and improve yellowing properties. Better, it has further improved solubility, can better balance high sensitivity and low yellowing, and is easier to synthesize and lower cost.

In yet another typical embodiment of the present application, a method for preparing the oxime ester photoinitiator of the present application is also provided, which includes the following steps: Step S1, convert carbazole with raw material A Carry out substitution reaction to obtain intermediate a Step S2, combine intermediate a and raw material B Carry out the first Friedel-Crafts reaction to obtain intermediate b Step S3, combine intermediate b and raw material C Carry out the second Friedel-Crafts reaction to obtain intermediate c Step S4, perform an oximation reaction between intermediate c and nitrite and/or nitrite ester to obtain intermediate d. Step S5, perform an esterification reaction between intermediate d and acid anhydride and/or acid chloride to obtain an oxime ester photoinitiator Among them, X is F, Cl, Br or I, m is 1 or 0, n is 1 or 0, x is 1 or 0, y is 1 or 0, and z is 1 or 0.

In this application, carbazole and raw material A are first subjected to a substitution reaction to realize substitution of carbazole N-H to obtain intermediate a; then intermediate a and raw material B are subjected to the first Friedel-Crafts reaction, so that raw material B is connected to the carbazole benzene ring, Obtain intermediate b; continue to carry out the second Friedel-Crafts reaction between intermediate b and raw material C, so that raw material C is connected to another carbazole benzene ring to obtain intermediate c; then intermediate c is reacted with nitrite and/or nitrite The nitrate ester undergoes an oximation reaction to form an aldoxime structure to obtain intermediate d; finally, intermediate d is subjected to an esterification reaction with acid anhydride and/or acid chloride to form an oxime ester structure, thereby obtaining the oxime ester photoinitiator of the present application.

The preparation method of the present application has a simple process, does not produce polluting waste, has high product purity and high yield, and is suitable for industrial production. The prepared oxime ester photoinitiator can have both high sensitivity and low yellowing. In the process of preparing the above-mentioned oxime ester compounds, the reaction reagents used are all known compounds in the prior art, and can be obtained commercially or conveniently prepared by existing synthesis methods.

On the basis of knowing the synthetic ideas disclosed in this application, the specific reaction conditions can be easily determined by those skilled in the art. In a preferred embodiment, in order to increase the yield, the nitrite is sodium nitrite and/or potassium nitrite, and the nitrite ester is ethyl nitrite, isoamyl nitrite and isooctyl nitrite. One or more of; and/or, the acid anhydride is acetic anhydride and/or benzoic anhydride, and the acid chloride is one or more of acetyl chloride, propionyl chloride and benzoyl chloride.

The above reaction is carried out in an organic solvent, and the type of organic solvent is not particularly limited, as long as it can dissolve the raw materials and has no adverse effect on the reaction. At the same time, in order to further increase the reaction rate, in a preferred embodiment, in step S1 , the substitution reaction is carried out under alkaline conditions, and the base is potassium hydroxide and/or sodium hydroxide; and/or, in step S2, the first Friedel-Crafts reaction is carried out under the catalysis of aluminum trichloride, the first Friedel-Crafts reaction The solvent is dichloromethane and/or dichloroethane; and/or, in step S3, the second Friedel-Crafts reaction is performed under the catalysis of aluminum trichloride, and the solvent of the second Friedel-Crafts reaction is dichloromethane and/or Or dichloroethane; and/or, in step S4, the oximation reaction is carried out under acidic conditions, the acid is concentrated hydrochloric acid and/or halogenated carboxylic acid, the halogenated carboxylic acid is chloroacetic acid or bromoacetic acid, the oximation reaction is The solvent is one or more of ethyl acetate, tetrahydrofuran and dichloromethane; and/or, in step S5, the esterification reaction is performed under alkaline conditions, and the base is triethylamine (TEA), diisopropyl ethyl One or more of amine and 4-dimethylaminopyridine.

The reactants added later in the reaction process can achieve a more complete reaction if the reactants added later are slightly excessive based on the proportion of the reaction formula. The reaction temperature varies slightly depending on the type of raw materials. In a preferred embodiment, in step S1, The molar ratio of raw material A to carbazole is (1~1.1):1; preferably, the reaction temperature of the substitution reaction is 50~100°C; more preferably, the reaction temperature of the substitution reaction is 50~80°C; and/or, Step S2, the molar ratio of raw material B to intermediate a is (1~1.1):1; preferably, the reaction temperature of the first Friedel-Crafts reaction is -10~10°C; more preferably, the reaction temperature of the first Friedel-Crafts reaction The temperature is 0~5℃; and/or, Step S3, the molar ratio of raw material C to intermediate b is (1~1.1):1; preferably, the reaction temperature of the second Friedel-Crafts reaction is -10~10°C; more preferably, the reaction temperature of the second Friedel-Crafts reaction The temperature is 0~5°C; and/or, in step S4, the molar ratio of nitrite and/or nitrite ester to intermediate c is (2~3.5):1; preferably, the reaction temperature of the oximation reaction is 0 ~30°C; more preferably, the reaction temperature of the oximation reaction is 20~25°C; and/or, in step S5, the molar ratio of acid anhydride and/or acid chloride to intermediate d is (2~2.8):1; preferably , the reaction temperature of the esterification reaction is 0-30°C; more preferably, the reaction temperature of the esterification reaction is 20-25°C, which can obtain the best reaction effect and the product yield is higher.

In yet another typical embodiment of the present application, the application of the oxime ester photoinitiator in photoresist is also provided. It is especially suitable for UV-LED light curing systems, especially suitable for initiating under the action of 365nm light source. It has excellent sensitivity after application, and has the characteristics of low yellowing and high solubility.

Without limitation, the oxime ester photoinitiator of the present application can also be used in paints, coatings, inks, and molding materials. Specifically, it can be used in the production of base materials such as plastics, metals, glass, ceramics, wood, and walls. Coatings for coating; protective film materials such as hard coating agents, antifouling films, anti-reflective films, and impact buffer films; photocurable adhesives, adhesives, photodegradable coatings, coatings, and molded articles; holographic imaging materials Optical recording media, etc.; optical molding resins, such as inks (resins) for 3D printing, photoresists for electronic circuits and semiconductor manufacturing, photoresists for electronic materials such as color filters, black matrices, and dry films in displays, etc. ; Interlayer insulation film, light extraction film, brightness enhancement film, sealing material; printing inks such as screen printing, offset printing, gravure printing, etc., light curing ink for inkjet printing; lenses, lens arrays, optical waveguides, light guide plates , light diffusion plates, diffraction elements and other optical components; optical gaps, ribs, nanoimprint materials, quantum dots, OLEDs, etc.

In yet another typical embodiment of the present application, a photocurable composition is also provided, including a photoinitiator. The photoinitiator is the oxime ester photoinitiator of the present application; preferably, in parts by weight, the photocurable composition The composition includes 800 to 1000 parts of solvent, 100 to 300 parts of acrylate copolymer, 50 to 150 parts of dipentaerythritol hexaacrylate, and 3 to 10 parts of oxime ester photoinitiator.

The type of solvent for the above composition is not particularly limited as long as it can dissolve the raw materials and has no adverse effect on the reaction. It can be one or more of butanone, ethyl acetate, tetrahydrofuran and methylene chloride. The acrylate copolymer is preferably a copolymer in which the molar ratio of benzyl methacrylate: methacrylic acid: hydroxyethyl methacrylate is 70:10:20, and Mw=10000. The photocurable composition not only has the characteristics of low yellowing, but also has high sensitivity, and can achieve both high sensitivity and low yellowing. It should be noted that the term "parts by weight" in this application has the same dimension, for example, they all represent 1g or 1kg.

The present application will be described in further detail below with reference to specific examples. These examples shall not be construed as limiting the scope of protection claimed by the present application.

Example 1

(1) Preparation of intermediate 1a

Add 20g carbazole (0.12mol), 16.70g cyclohexylmethyl chloride (0.13mol), 5.76g sodium hydroxide (0.14mol) and 100mL DMF into a 250mL three-necked flask, raise the temperature to 80°C for substitution reaction, and stir for 4 hours; TLC confirmed that the raw material reaction was complete. The reaction solution was cooled to room temperature, filtered through Celite, and 100 mL of methylene chloride was added to the filtrate, then washed with water (200 mL Crystallize for 2 hours, filter, collect the solid, and dry it in an oven at 40°C to obtain 24.81g of white solid, namely intermediate 1a, with a yield of 78.5%.

(2) Preparation of intermediate 1c

Dissolve 24g of intermediate 1a (0.090mol) and 12.60g of aluminum trichloride (0.095mol) in 100mL of dichloromethane, and cool the temperature to 0~5°C; dissolve 15.88g of cyclohexylpropionyl chloride (0.091mol) in 20mL of dichloromethane. In methyl chloride, add dropwise to the reaction solution, and perform the first Friedel-Crafts reaction at a temperature of 0 to 5°C; after the dropwise addition, continue stirring for 1 hour, the raw materials react completely, and intermediate 1b is obtained.

Then cool the temperature to 0~5℃, then add 12.60g aluminum trichloride (0.095mol), then dissolve 14.64g n-octanoyl chloride (0.095mol) in 20mL methylene chloride, add it to the reaction solution, and control the temperature from 0~ Carry out the second Friedel-Crafts reaction at 5°C. After the dropwise addition, continue stirring for 1 hour. TLC confirms that the reaction is complete. Slowly add the reaction solution to 500 mL of ice water, stir thoroughly, and let stand for half an hour. The organic phase is washed with water (100 mL Crystallize for 2 hours, filter, and dry the obtained solid at 60°C to obtain 40.19g of white solid, namely intermediate 1c, with a yield of 84.6%.

(3) Preparation of compound 1d

Add 45g of intermediate 1c (0.085mol) and 270mL of ethyl acetate into a 500L round-bottom flask, add 25.5mL of concentrated hydrochloric acid, and add 29.97g of isoamyl nitrite (0.256mol) dropwise under a nitrogen atmosphere at room temperature. After completion, continue the oximation reaction for 2 hours. Add 200 mL sodium chloride aqueous solution to the reaction solution, separate the organic phase, wash the organic phase with water (200 mL 33.91g of light yellow solid was obtained, namely intermediate 1d, with a yield of 68.1%.

(4) Preparation of compound 1

Add 48g of intermediate 1d (0.082mol), 8.70g of TEA (0.172mol) and 240mL of methylene chloride into a 500mL reaction bottle, and stir to dissolve. Add 8.78g acetic anhydride (0.172 mol) dropwise, and stir at room temperature for 2 hours to perform esterification reaction. Add 200 mL of water to the reaction solution, stir for 10 min, let stand for layering, separate the lower organic phase, wash with water until neutral, concentrate the organic phase, dissolve the solid obtained with 200 mL of methanol, and stir under reflux for 1 h. Cool to room temperature, stir for 1 hour, then cool to 5-10°C in ice bath, and stir for 1 hour. Filter, and wash the filter cake with 200 mL methanol to obtain crude product. Dissolve the crude product in 150 mL acetone, add it to 300 mL methanol, stir to crystallize, continue stirring in an ice bath for 1 hour, filter, rinse the filter cake with 200 mL methanol, and dry the solid in a 60°C vacuum drying oven for 24 hours to obtain 34.39 g of shallow Yellow solid, compound 1, yield 62.6%, purity 99.12%.

The structure of compound 1 was confirmed by the following NMR data:

1H NMR (500MHz, Chloroform-d) δ8.61～8.57 (m, 1H), 8.57～8.53 (m, 1H), 7.97 (dd, J=7.5, 1.5Hz, 1H), 7.92 (dd, J=7.5 , 1.5Hz, 1H), 7.80 (d, J=7.5Hz, 1H), 7.58 (d, J=7.5Hz, 1H), 4.12 (d, J=7.1Hz, 2H), 2.91 (d, J=7.0 Hz, 2H), 2.76 (t, J=7.1Hz, 2H), 2.15 (s, 6H), 2.04 (dq, J=13.9, 7.0Hz, 1H), 1.95 (hept, J=7.0Hz, 1H), 1.65(p, J=7.1Hz, 2H), 1.59~1.50(m, 5H), 1.54~1.38(m, 16H), 1.37~1.23(m, 5H), 0.93~0.85(m, 3H).

Examples 2 to 13

According to the method of Example 1 and replacing the corresponding raw materials, the following compounds 2 to 13 were prepared. Their structures and corresponding NMR characterization data are listed in Table 1 below.

Table 1

Examples 14 to 19

The difference between Examples 14 to 19 and Example 1 is that the molar ratio of reactants in each reaction is different. See Table 2 for details.

Table 2

Examples 20 to 25

The difference between Examples 20 to 25 and Example 1 lies in the different reaction temperatures. See Table 3 for details.

table 3

In the process of preparing the same compound product, different reaction conditions were changed, and the yield and purity of Compound 1 obtained in Example 1 and Examples 14 to 25 are shown in Table 4.

Table 4

It can be seen from Table 2 to Table 4 that when the preparation molar ratio of each step of the embodiment is within the preferred range of the present application, the yield and purity of the oxime ester photoinitiator are the highest. If it is too low, the reaction will be insufficient and exceed this limit. The improvement in yield and purity is not obvious when applying within the scope. Instead, it causes a waste of reagents and raw materials, and may even cause side reactions that affect product purity. When the example When the reaction temperature of each step is within the preferred range of this application, the yield and purity of the oxime ester photoinitiator will be the highest. If the temperature is too low, the reaction will be incomplete and the reaction rate will be slow. If the temperature is too high and exceeds the range of this application, The improvement in yield and purity is not obvious, but leads to increased costs. Therefore, it is preferred that the molar ratio of preparation and the reaction temperature are within the preferred ranges of this application.

Performance evaluation

It should be noted that the photocurable compositions used in the photosensitivity tests in Examples 1 to 13 and Comparative Examples 1 to 4 of the present application were prepared according to the proportions in Table 5. For example, in parts by weight, the photocurable composition of Example 1 includes: 200 parts of acrylate copolymer, 100 parts of dipentaerythritol hexaacrylate, 5 parts of photoinitiator, 900 parts of butanone (solvent), and 5 parts of dye blue 15 (CAS: 147-14-8), and the above-mentioned acrylate copolymer (manufacturer: Changzhou Qianli Electronic New Materials Co., Ltd.) is benzyl methacrylate/methacrylic acid/hydroxyethyl methacrylate (molar ratio is 70:10:20) copolymer, Mw=10000. In the above-mentioned photocurable composition, the photoinitiator is the oxime ester compound represented by the general formula (I) in the foregoing content of the application or a similar photoinitiator known in the prior art for comparison.

table 5

1. Dissolution performance test

The solubility of the oxime ester photoinitiator in propylene glycol methyl ether acetate (PGMEA) is one of the index parameters that represents its solubility and measures the application performance of the photoinitiator. Compounds with the structure shown in general formula (I) were selected and the solubility of compounds 1 to 13 and compounds A, B, C, and D in PGMEA at 25°C were tested respectively. The test results are shown in Table 6.

2. Photosensitive performance test

(1) Sensitivity test

The compositions of Examples 1 to 13 and Comparative Examples 1 to 4 were protected from light and stirred, and then coated on a 21-step scale using a #6 wire rod to form a coating film with a film thickness of about 15 μm. Expose the coating film with an LED lamp (385nm), give an energy of 191mJ/ ^cm2 (100% light intensity, 8m/min*2 times), develop with 2% NaOH aqueous solution for 2 minutes after curing, rinse with tap water for 1 minute, and observe The test results of the gradient ruler are shown in Table 6.

(2)Yellowing resistance test

After the photocurable compositions of Examples 1 to 13 and Comparative Examples 1 to 4 were fully stirred in a yellow light room, the composition was coated on tinplate using a 15# wire rod to form a coating film with a wet film thickness of 10 μm. Use 365nm-LED light source for exposure and receive 2000mJ/ ^cm2 energy to fully cure it. An X-Rite colorimeter was used to conduct a yellowing test, and the yellowing resistance of the light-cured resin was judged based on the Δb value. The higher the Δb value, the more obvious the yellowing and the worse the yellowing resistance. The yellowing resistance test results of Examples 1 to 13 and Comparative Examples 1 to 4 are shown in Table 6.

Table 6

In summary, it can be seen that compared with traditional photoinitiators, the oxime ester initiator shown in formula (I) disclosed in the present application has excellent solubility in organic solvents, has the characteristics of high sensitivity and low yellowing after application, and is easy to Synthetic, low cost, and has good application prospects in the field of photocuring.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application.

Claims

An oxime ester photoinitiator is characterized by having a structure represented by general formula (I):

Wherein, R 1 and R 2 are independently selected from substituted or unsubstituted C 1 to C 20 alkyl groups, substituted or unsubstituted C 3 to C 20 cycloalkyl groups, substituted or unsubstituted C 6 to C 20 aryl group, substituted or unsubstituted C 4 to C 20 heteroaryl group, substituted or unsubstituted C 3 to C 20 alicyclic heterocyclic group; m is 1 or 0, n is 1 or 0, x is 1 or 0, y is 1 or 0, z is 1 or 0.
The oxime ester photoinitiator according to claim 1, characterized in that,

In the substituted C 1 to C 20 alkyl group, the substituent is selected from C 3 to C 12 cycloalkyl groups; optionally, in the substituted or unsubstituted C 1 to C 20 alkyl group, at least One -CH 2 - is replaced by -O- or -S-;

In the substituted C 3 to C 20 cycloalkyl group, the substituent is selected from C 1 to C 10 linear or branched chain alkyl groups;

In the substituted C 6 to C 20 aryl group, the substituent is selected from C 1 to C 6 linear or branched alkyl groups, C 1 to C 10 linear or branched alkoxy groups, C 1 to C 10 linear or branched alkylthio group, C 1 to C 8 linear or branched acyl group, C 1 to C 8 linear or branched acyloxy group, halogen atom, cyano group or nitro group one or more;

In the substituted C 4 to C 20 heteroaryl group, the substituent is selected from a C 1 to C 8 linear or branched alkyl group;

In the substituted C 3 to C 20 alicyclic heterocyclic group, the substituent is selected from C 1 to C 6 linear or branched chain alkyl groups.
The oxime ester photoinitiator according to claim 1 or 2, characterized in that R 1 and R 2 are each independently selected from a C 1 to C 20 alkyl group or a C 6 to C 20 aryl group; preferably, R 1 and R 2 are each independently selected from methyl, ethyl or phenyl.
The oxime ester photoinitiator according to any one of claims 1 to 3, characterized in that the oxime ester photoinitiator has a structure shown in any one of the structural formulas (1) to (13):
The oxime ester photoinitiator according to any one of claims 1 to 4, characterized in that the oxime ester photoinitiator is
The preparation method of the oxime ester photoinitiator according to any one of claims 1 to 5, characterized in that the preparation method includes the following steps:

Step S1, carbazole with raw material A Carry out substitution reaction to obtain intermediate a

Step S2, combine the intermediate a and raw material B Carry out the first Friedel-Crafts reaction to obtain the intermediate b

Step S3, combine the intermediate b and raw material C Carry out the second Friedel-Crafts reaction to obtain intermediate c

Step S4, perform an oximation reaction between the intermediate c and nitrite and/or nitrite ester to obtain the intermediate d.

Step S5, perform an esterification reaction between the intermediate d and acid anhydride and/or acid chloride to obtain the oxime ester photoinitiator

Among them, X is F, Cl, Br or I, m is 1 or 0, n is 1 or 0, x is 1 or 0, y is 1 or 0, and z is 1 or 0.
The preparation method according to claim 6, characterized in that:

In the step S1, the substitution reaction is carried out under alkaline conditions, and the base is potassium hydroxide and/or sodium hydroxide; and/or,

In the step S2, the first Friedel-Crafts reaction is carried out under the catalysis of aluminum trichloride, and the solvent of the first Friedel-Crafts reaction is dichloromethane and/or dichloroethane; and/or,

In the step S3, the second Friedel-Crafts reaction is carried out under the catalysis of aluminum trichloride, and the solvent of the second Friedel-Crafts reaction is dichloromethane and/or dichloroethane; and/or,

In the step S4, the nitrite is sodium nitrite and/or potassium nitrite, and the nitrite is one or more of ethyl nitrite, isoamyl nitrite and isooctyl nitrite. ; Preferably, the oximation reaction is carried out under acidic conditions, the acid is concentrated hydrochloric acid and/or halogenated carboxylic acid, the halogenated carboxylic acid is chloroacetic acid or bromoacetic acid, and the solvent of the oximation reaction is ethyl acetate. One or more of ester, tetrahydrofuran and methylene chloride; and/or,

In the step S5, the acid anhydride is acetic anhydride and/or benzoic anhydride, and the acid chloride is one or more of acetyl chloride, propionyl chloride and benzoyl chloride; preferably, the esterification reaction is carried out in an alkaline The base is one or more of triethylamine, diisopropylethylamine and 4-dimethylaminopyridine.
The preparation method according to claim 6 or 7, characterized in that,

In the step S1, the molar ratio of the raw material A to the carbazole is (1~1.1):1; preferably, the reaction temperature of the substitution reaction is 50~100°C; more preferably, the substitution The reaction temperature of the reaction is 50~80°C; and/or,

In the step S2, the molar ratio of the raw material B to the intermediate a is (1~1.1):1; preferably, the reaction temperature of the first Friedel-Crafts reaction is -10~10°C; more preferably Ground, the reaction temperature of the first Friedel-Crafts reaction is 0~5°C; and/or,

In the step S3, the molar ratio of the raw material C and the intermediate b is (1~1.1):1; preferably, the reaction temperature of the second Friedel-Crafts reaction is -10~10°C; more preferably Ground, the reaction temperature of the second Friedel-Crafts reaction is 0~5°C; and/or,

In the step S4, the molar ratio of the nitrite and/or nitrite ester to the intermediate c is (2-3.5):1; preferably, the reaction temperature of the oximation reaction is 0-30 ℃; more preferably, the reaction temperature of the oximation reaction is 20 to 25 ℃; and/or,

In the step S5, the molar ratio of the acid anhydride and/or acid chloride to the intermediate d is (2-2.8):1; preferably, the reaction temperature of the esterification reaction is 0-30°C; more preferably Preferably, the reaction temperature of the esterification reaction is 20-25°C.
Application of the oxime ester photoinitiator described in any one of claims 1 to 5 in photoresist.
A photocurable composition, including a photoinitiator, characterized in that the photoinitiator is the oxime ester photoinitiator described in any one of claims 1 to 5; preferably, in parts by weight, the The photocurable composition includes 800 to 1000 parts of solvent, 100 to 300 parts of acrylate copolymer, 50 to 150 parts of dipentaerythritol hexaacrylate, and 3 to 10 parts of the oxime ester photoinitiator.