WO2023169520A1

WO2023169520A1 - Use of arylvinyl a-carbonyl acid ester compound as photoinitiator in led photopolymerization and preparation method therefor

Info

Publication number: WO2023169520A1
Application number: PCT/CN2023/080561
Authority: WO
Inventors: 孙芳; 唐招贤
Original assignee: 湖北固润科技股份有限公司
Priority date: 2022-03-09
Filing date: 2023-03-09
Publication date: 2023-09-14
Also published as: CN114716315A

Abstract

The use of an arylvinyl α-carbonyl acid ester compound (I) as a photoinitiator in LED photopolymerization and a preparation method therefor, which relate to the field of polymer photocuring, and are provided on the basis of the problems that an existing photoinitiator has a weak initiation capability under an LED light source, the color of a cured film is relatively deep and cannot be used for deep polymerization, etc. The initiator has a certain absorption in the visible light area, such that the initiator has a relatively high initiation efficiency under an LED light source; moreover, the initiator also has a good photo-bleaching performance, such that the initiator can be used in colorless polymerization and deep polymerization to facilitate the development of the LED photopolymerization industry.

Description

Use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization and its preparation method

Technical field

The invention relates to the field of photopolymerization, and specifically to the use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization and its preparation method.

Background technique

Most of the matching light sources for commercial photoinitiators are high-pressure mercury lamps, but high-pressure mercury lamps have shortcomings such as high energy consumption, slow startup, and environmental pollution. Compared with traditional high-pressure mercury lamps, LED light sources have the advantages of energy saving, environmental protection, long life, and easy startup. Therefore, the development of photoinitiators that can match LED light sources is a current research hotspot. Most of the reported new photoinitiator molecules suitable for LED light sources require relatively complex synthesis processes and contain large conjugated structures within the molecules. This will lead to problems such as poor compatibility between the initiator molecules and the monomer, darker color of the cured film, inability to be used in deep polymerization, and higher usage costs. These problems have limited the wide application of photoinitiators. Therefore, it is of great practical significance to develop a photoinitiator that has a simple structure, low synthesis cost, and can be used in LED photopolymerization and colorless photopolymerization materials.

Currently, many commercial photoinitiators are carbonyl ester compounds such as methyl benzoylformate, benzoyl, camphorquinone, etc. However, as a UV photoinitiator, they are not suitable for LED light sources that emit longer wavelengths. . If conjugated double bonds are introduced into its structure, it can not only extend its absorption wavelength, but also participate in the polymerization through the double bonds to make it have excellent photobleaching and biocompatibility, broadening its application fields.

Contents of the invention

The technical problem solved by the present invention is to provide the use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization and its preparation method. The initiator absorbs in the visible light region and can well match LED light sources (385nm, 395nm, 405nm, 455nm). The photoinitiator prepared by the invention shows good initiating performance under both 405nm and 455nm LED light sources. In addition, the initiator also has good photobleaching properties and can be used in the field of LED deep polymerization and colorless photopolymerization materials. This type of photoinitiator only requires a simple two-step reaction, has mild synthesis conditions, low synthesis cost, and has extremely high practical value.

In order to achieve the above objects, the present invention adopts the following technical solutions:

1. The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization and its preparation method, characterized in that the structural formula of the compound is:

M stands for:

Wherein R ₁ is selected from O, S, -NH-, C1-C20 alkylamino group; R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different, and are independently selected from hydrogen, halogen atoms, C1-C20 alkoxy group, C1-C20 alkylmercapto group, C1-C20 hydroxyalkyl group, hydroxyl group, dialkylamino group, -OCF ₃ , -OC ₆ H ₅ , -COOH, -CHO, -NO ₂ , -CN;

R ₇ is selected from hydrogen, benzyl, C1-C20 alkyl, C1-C20 hydroxyalkyl,

2. The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization according to item 1 and its preparation method, characterized in that M is R _2, , R ₃ , R ₄ and R ₅ are the same, and are independently selected as H; R ₆ is selected from fluorine, hydrogen, methoxy and methylmercapto.

3. The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization according to any one of items 1-2 and its preparation method, characterized in that R ₇ is selected from C1- A C20 alkyl group and a C1-C20 hydroxyalkyl group are preferably a C1-C20 alkyl group, and more preferably an ethyl group.

4. The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization according to any one of items 1 to 3 and its preparation method, which is characterized in that the general synthesis process of the compound for:

The definitions of M and R ₇ are as described in item 1.

5. The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization according to item 4 and its preparation method, characterized in that the preparation method of the compound includes the following steps:

In the step (a), the aromatic aldehyde and pyruvic acid are dissolved in alcohol and added to the reaction vessel, then an appropriate amount of alkali is dissolved in alcohol and added to the reactor, and stirred at 35°C for 6 hours; then, After distilling off the alcohol under reduced pressure, a crude product is obtained. The crude product is dissolved in water and washed three times with ethyl acetate; an appropriate amount of acid is added to the water phase to adjust the pH to 3, and extracted three times with ethyl acetate; the acetic acid is then distilled under reduced pressure. Ethyl ester to obtain intermediate product A;

In step (b), the dehydrating agent and catalyst are dissolved in alcohol and added to the reaction vessel. Then, the intermediate product A is dissolved in alcohol and dropped into the reaction vessel. Continue stirring for 2 hours; distill under reduced pressure. The alcohol is removed to obtain a crude product, which is separated using a chromatographic column to obtain the final product.

6. The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization according to item 5 and its preparation method, characterized in that in the step (a), the alcohol is selected From methanol and ethanol; the base is selected from potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate; the molar ratio of aromatic aldehyde and pyruvic acid is 1:1-1:1.5, and the quality of the alcohol is 10-10% of the aromatic aldehyde. 60 times, the molar weight of the base is 150%-300% of the aromatic aldehyde; in the step (b), the dehydrating agent is selected from dicyclohexylcarbodiimide, diisopropylcarbodiimide and 1- (3-dimethylaminopropyl)-3-ethylcarbodiimide; the catalyst is selected from 4-dimethylaminopyridine, piperidine, 3-methylpiperidine, and triethylamine; the acid is selected from From hydrochloric acid, sulfuric acid, acetic acid, boric acid; the molar amount of the catalyst is 2%-10% of the intermediate product A, the molar amount of the dehydrating agent is 100%-150% of the intermediate product A, and the molar amount of alcohol added is 2%-150% of the intermediate product A. 100%-150%.

7. A free radical photopolymerizable composition, characterized in that, based on the total weight of the composition, The composition includes the aryl vinyl α-carbonyl acid ester compound, a hydrogen donor and a photo-curable resin or monomer; the aryl vinyl α-carbonyl acid ester compound, a hydrogen donor and a photo-curable resin or The mass ratio of the monomers is 0.5:1.5:100; the hydrogen donor is selected from triethylamine, triethanolamine, diethanolamine, ethyl 4-dimethylaminobenzoate; the photocurable resin is selected from epoxy (methane) base) acrylic resin, polyester (meth) acrylic resin, polyether (meth) acrylic resin, one or more of acrylated poly (meth) acrylic resin, polyurethane (meth) acrylic resin; The above-mentioned monomer is one or more of monofunctional, difunctional or multifunctional (meth)acrylates.

8. Application of the arylvinyl α-carbonyl acid ester compound described in item 1 in colorless photopolymerization.

9. Application of the arylvinyl α-carbonyl acid ester compound described in item 1 in deep photopolymerization.

In the following description of the invention, unless otherwise expressly stated, numerical values in this application may be deemed to be modified by the word "about". However, the inventors have reported the numerical values in the Examples as accurately as possible, although these numerical values inevitably include certain errors.

The beneficial effects of the present invention are: compared with traditional photoinitiators, the photoinitiator prepared by the present invention can be used in the field of LED photocuring, and has good initiating performance in the LED long wavelength band (405nm, 455nm), and the initiator It has very excellent photobleaching performance and deep curing performance. It can be used for LED deep photopolymerization and contributes to the development of the photocuring field.

Description of the drawings

Figure 1 is a diagram of the initiation mechanism of the photoinitiator provided by the present invention;

Figures 2 and 3 are UV absorption spectra of the arylvinyl α-carbonyl ester photoinitiators prepared in Synthesis Example 1, Example 2, Example 3 and Example 4;

Figure 4 is the polymerization of monomer tripropylene glycol diacrylate initiated by the arylvinyl α-carbonyl ester photoinitiator prepared in Synthesis Example 1, Example 2, Example 3 and Example 4 under a 405nm LED light source. Photopolymerization kinetic diagram;

Figure 5 is the polymerization of monomer tripropylene glycol diacrylate initiated by the arylvinyl α-carbonyl ester photoinitiator prepared in Synthesis Example 1, Example 2, Example 3 and Example 4 under a 455nm LED light source. Photopolymerization kinetic diagram;

Figure 6 shows how the arylvinyl α-carbonylate photoinitiator prepared in Synthesis Example 1, Example 2, Example 3 and Example 4 initiates the polymerization of monomer trimethylolpropane triacrylate under a 455nm LED light source. Photopolymerization kinetic diagram;

Figure 7 is a color comparison diagram before and after polymerization of the monomer tripropylene glycol diacrylate initiated by the arylvinyl α-carbonyl ester photoinitiator S-ECF prepared in Synthesis Example 3.

Figure 8 is a depth curing diagram of the arylvinyl α-carbonyl ester photoinitiator S-ECF initiating monomer tripropylene glycol diacrylate prepared in Synthesis Example 3.

Detailed ways

In order to make the technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below through examples and in conjunction with the accompanying drawings. The following examples illustrate the present invention in detail, but do not limit the scope of the present invention.

The above-mentioned photoinitiator can react with a hydrogen donor to generate alkyl radicals under the irradiation of commonly used LED light sources (emission wavelengths are 385nm, 395nm, 405nm and 455nm) to generate alkyl radicals, thereby initiating monomer polymerization. The mechanism is shown in Figure 1. Show: Under light, the photoinitiator transitions from the ground state to the excited state. The photoinitiator molecules in the excited state and the hydrogen donor first undergo an electron transfer reaction, and then a hydrogen abstraction reaction occurs between the two, and finally an alkyl radical is generated. , alkyl radicals initiate monomer polymerization.

Example 1:

Synthesis of photoinitiator ECF, the synthesis route of ECF is as follows:

(a) Dissolve benzaldehyde (1.06g, 10mmol) and pyruvic acid (0.88g, 10mmol) in 30mL ethanol and add it to a 100mL single-neck flask; then dissolve KOH (0.84g, 15mmol) in 20mL ethanol and drop it Pour into a single-necked flask and stir at room temperature for 6 hours. After the reaction was completed, the ethanol was distilled off under reduced pressure to obtain a yellow solid. The solid was dissolved in 40 mL of deionized water and washed three times with ethyl acetate (20 mL × 3). Add an appropriate amount of dilute hydrochloric acid to the aqueous phase until the pH is 3; then, use ethyl acetate (20 mL × 3) to extract the aqueous phase three times, combine the organic phases, and use vacuum distillation to remove the ethyl acetate to obtain the intermediate product CFA.

(b) Add dicyclohexylcarbodiimide (DCC, 1.08g, 10mmol), 4-dimethylaminopyridine (DMAP, 0.12g, 1mmol) and 40mL ethanol into a 100mL single-neck flask and start stirring. Then CFA (1.76g, 10mmol) was dissolved in 20mL of ethanol, and then the mixture was dropped into a one-neck flask. After the reaction was completed, ethanol was removed by distillation under reduced pressure to obtain a brown mixture. The crude product was purified by column chromatography to obtain yellow liquid ECF.

The hydrogen spectrum data of the photoinitiator ECF are: ¹ H NMR (400MHz, Chloroform-d) δ7.84 (d, J = 16.1Hz, 1H), 7.66–7.58 (m, 2H), 7.49–7.36 (m, 3H) ),7.35(d,J＝16.1Hz,1H),4.39(q,J＝7.1Hz,2H),1.40(t,J＝7.1Hz,3H).

The carbon spectrum data of photoinitiator ECF is: ¹³ C NMR (100MHz, Chloroform-d) δ182.85,162.20,148.36,134.01,131.61,129.08,129.02,120.58,62.47,14.07.

Example 2:

Synthesis of photoinitiator F-ECF, the synthesis route of F-ECF is as follows:

(a) Dissolve p-fluorobenzaldehyde (1.24g, 10mmol) and pyruvic acid (0.88g, 10mmol) in 30mL ethanol and add it to a 100mL single-neck flask; then dissolve KOH (0.84g, 15mmol) in 20mL ethanol And drop into a single-necked flask, stir at room temperature for 6 hours. After the reaction was completed, the ethanol was distilled off under reduced pressure to obtain a yellow solid. The solid was dissolved in 40 mL of deionized water and washed three times with ethyl acetate (20 mL × 3). Add an appropriate amount of dilute hydrochloric acid to the aqueous phase until the pH is 3; then, use ethyl acetate (20 mL × 3) to extract the aqueous phase three times, combine the organic phases, and use vacuum distillation to remove the ethyl acetate to obtain the intermediate product F-CFA.

(b) Add dicyclohexylcarbodiimide (DCC, 1.08g, 10mmol), 4-dimethylaminopyridine (DMAP, 0.12g, 1mmol) and 40mL ethanol into a 100mL single-neck flask and start stirring. Then F- CFA (1.94g, 10mmol) was dissolved in 20mL ethanol, and then the mixture was dropped into a one-neck flask. After the reaction was completed, ethanol was removed by distillation under reduced pressure to obtain a brown mixture. The crude product was purified by column chromatography to obtain yellow solid F-ECF.

The hydrogen spectrum data of the photoinitiator F-ECF are: ¹ H NMR (400MHz, Chloroform-d) δ7.80 (d, J = 16.1Hz, 1H), 7.67–7.57 (m, 2H), 7.28 (d, J) =16.1Hz,1H),7.16–7.05(m,2H),4.38(q,J=7.1Hz,2H),1.40(t,J=7.2Hz,3H).

The carbon spectrum data of photoinitiator F-ECF are: ¹³ C NMR (100MHz, Chloroform-d) δ182.57,165.91,163.38,162.10,146.90,131.11,131.03,130.35,130.32,120.27,120.25,116.44,116. 22,62.51, 14.03.

Example 3:

Synthesis of photoinitiator S-ECF, the synthesis route of S-ECF is as follows:

(a) Dissolve 4-(methylmercapto)benzaldehyde (1.52g, 10mmol) and pyruvic acid (0.88g, 10mmol) in 30mL ethanol and add it to a 100mL single-neck flask; then add KOH (0.84g, 15mmol) Dissolve in 20 mL of ethanol and drop into a one-neck flask, stir at room temperature for 6 hours. After the reaction was completed, the ethanol was distilled off under reduced pressure to obtain a yellow solid. The solid was dissolved in 40 mL of deionized water and washed three times with ethyl acetate (20 mL × 3). Add an appropriate amount of dilute hydrochloric acid to the aqueous phase until the pH is 3; then, use ethyl acetate (20 mL × 3) to extract the aqueous phase three times, combine the organic phases, and use vacuum distillation to remove the ethyl acetate to obtain the intermediate product S-CFA.

(b) Add dicyclohexylcarbodiimide (DCC, 1.08g, 10mmol), 4-dimethylaminopyridine (DMAP, 0.12g, 1mmol) and 40mL ethanol into a 100mL single-neck flask and start stirring. Then S- CFA (2.2g, 10mmol) was dissolved in 20mL ethanol, and then the mixture was dropped into a one-neck flask. After the reaction was completed, ethanol was removed by distillation under reduced pressure to obtain a brown mixture. The crude product was purified by column chromatography to obtain S-ECF as a yellow solid.

The hydrogen spectrum data of the photoinitiator S-ECF are: ¹ H NMR (400MHz, Chloroform-d) δ7.83 (d, J = 16.1 Hz, 1H), 7.60–7.51 (m, 2H), 7.33 (d, J) =16.1Hz,1H),7.28–7.23(m,2H),4.41(q,J＝7.2Hz,2H),2.53(s,3H),1.43(t,J＝7.2Hz,3H).

The carbon spectrum data of the photoinitiator S-ECF are: ¹³ C NMR (100MHz, Chloroform-d) δ182.67,162.34,147.89,144.22,130.41,129.39,125.76,119.36,62.48,14.91,14.09.

Example 4:

Synthesis of photoinitiator O-ECF, the structural formula of O-ECF is as follows:

(a) Dissolve p-methoxybenzaldehyde (1.52g, 10mmol) and pyruvic acid (0.88g, 10mmol) in 30mL ethanol and add it to a 100mL single-neck flask; then dissolve KOH (0.84g, 15mmol) in 20mL into ethanol and dropwise into a single-necked flask, stirring at room temperature for 6 hours. After the reaction was completed, the ethanol was distilled off under reduced pressure to obtain a yellow solid. The solid was dissolved in 40 mL of deionized water and washed three times with ethyl acetate (20 mL × 3). Add an appropriate amount of dilute hydrochloric acid to the aqueous phase until the pH is 3; then, use ethyl acetate (20 mL × 3) to extract the aqueous phase three times, combine the organic phases, and use vacuum distillation to remove the ethyl acetate to obtain the intermediate product O-CFA.

(b) Add dicyclohexylcarbodiimide (DCC, 1.08g, 10mmol), 4-dimethylaminopyridine (DMAP, 0.12g, 1mmol) and 40mL ethanol into a 100mL single-neck flask and start stirring. Then O-CFA (2.06g, 10mmol) was dissolved in 20mL ethanol, and then the mixture was dropped into a one-neck flask. opposite After the reaction was completed, the ethanol was removed by distillation under reduced pressure to obtain a brown mixture. The crude product was purified by column chromatography to obtain O-ECF as a yellow solid.

The hydrogen spectrum data of the photoinitiator O-ECF are: ¹ H NMR (400MHz, Chloroform-d) δ7.80 (d, J = 16.0 Hz, 1H), 7.61–7.53 (m, 2H), 7.21 (d, J) ＝16.0Hz,1H),6.96–6.87(m,2H),4.37(q,J＝7.2Hz,2H),3.83(s,3H),1.39(t,J＝7.1Hz,3H).

The carbon spectrum data of the photoinitiator O-ECF is: ¹³ C NMR (100MHz, Chloroform-d) δ182.68,162.60,162.50,148.26,131.03,126.80,118.20,114.58,77.33,62.34,55.45,14.07.

Example 5:

The purpose of Example 5 is to illustrate the light absorption properties of the arylvinyl α-carbonylate photoinitiators prepared in Examples 1-4.

The photoinitiators prepared in Examples 1-4 were respectively prepared into anhydrous acetonitrile solution with a concentration of 1×10 ^-4 mol L ^-1 . Use a UV spectrophotometer to test the absorption curves of the four solutions in the wavelength range of 200-500 nm, that is, the UV-visible absorption spectrum.

The measured UV-visible absorption spectra of the four photoinitiators are shown in Figures 2 and 3; from Figures 2 and 3, it can be found that the maximum absorption wavelengths of the four photoinitiators are between 300-400nm, and at 400nm There is also absorption between -455nm. Therefore, it can be ensured that the absorption wavelength of the photoinitiator matches the emission wavelength of the LED light source.

Example 6-7

The purpose of Examples 6-7 is to demonstrate that the arylvinyl α-carbonyl ester photoinitiator prepared in Examples 1-4 has good initiating properties for acrylate monomers under LED light source irradiation.

1. Prepare photosensitive liquid

Two acrylate monomers, the hydrogen donor 4-dimethylaminoethyl benzoate (EDB) and the arylvinyl α-carbonyl ester photoinitiator prepared in Examples 1-4 were selected respectively, according to the following proportions, Prepare photosensitive solution:

Example 6: Weigh an appropriate amount of monomer tripropylene glycol diacrylate (TPGDA), photoinitiator and EDB and stir evenly to form a photosensitive liquid. Their ratio is: photoinitiator:EDB:TPGDA=0.5:1.5:100 (mass ratio).

Example 7: Weigh an appropriate amount of monomer trimethylolpropane triacrylate (TMPTA), photoinitiator and EDB and stir evenly to form a photosensitive liquid. Their mass ratio is: photoinitiator:EDB:TMPTA=0.5:1.5 :100.

2. Aggregation performance test

Apply the prepared photosensitive liquid evenly on the potassium bromide salt flakes. The thickness of the photosensitive liquid coating is about 30 μm, and then cover the potassium bromide salt flakes on the coating. Use a real-time infrared spectrometer (Thermo Fisher Scientific, USA, model Nicolet 5700) to detect the photosensitive liquid at 405nm and 455nm LED light sources (Shenzhen Lambric Technology Co., Ltd., model UVEC-4II, light intensity 50mW/cm ² ) Polymerization under irradiation.

The photopolymerization test results of the photosensitive liquids prepared in Example 6 and Example 7 are shown in Figure 4, Figure 5 and Figure 6 respectively. The photoinitiator prepared in the present invention can effectively initiate the photopolymerization reaction of acrylate monomer under the irradiation of 405nm and 455nm LED light sources, which shows that the photoinitiator of the present invention has better initiating performance under the LED photopolymerization system. and applicability.

Example 8

The purpose of Example 8 is to demonstrate that the arylvinyl α-carbonyl ester photoinitiator S-ECF prepared in Example 3 has good photobleaching performance under LED light source irradiation.

1. Prepare photosensitive solution

Tripropylene glycol diacrylate monomer (TPGDA) and hydrogen donor 4-dimethylaminoethyl benzoate (EDB) were selected as well as the arylvinyl α-carbonyl ester photoinitiator S- prepared in Example 3. ECF, prepare photosensitive liquid according to the following proportions:

Photoinitiator S-ECF:EDB:tripropylene glycol diacrylate=0.5:1.5:100 (mass ratio)

2. Photobleaching performance test

Drop the photosensitive liquid into the silicone mold, and then cover it with a coverslip to ensure that there are no air bubbles between the coverslip and the liquid surface. Use 455nm and 405nm LED light sources to illuminate for 8s and 15s respectively.

The results of the photobleaching test of the photosensitive liquid prepared in Example 8 are shown in Figure 7. The cured film of the photoinitiator S-ECF prepared by the present invention becomes colorless after being irradiated by LED light sources of 405nm and 455nm for 15 seconds, indicating that the prepared photoinitiator S-ECF shows good photobleaching under the irradiation of LED light sources. performance.

Example 9

The purpose of Example 9 is to illustrate that the arylvinyl α-carbonyl ester photoinitiator S-ECF prepared in Example 3 has the ability to initiate deep polymerization under the irradiation of an LED light source.

1. Prepare photosensitive liquid

Use tripropylene glycol diacrylate monomer and hydrogen donor 4-dimethylaminoethyl benzoate (EDB) And the aryl vinyl α-carbonyl ester photoinitiator S-ECF prepared in Example 3, prepare a photosensitive liquid according to the following proportions:

2. Aggregation depth test

Inject the prepared photosensitive liquid into a glass tube with a depth of 8cm and a diameter of 0.6cm, and use an LED light source with an emission wavelength of 455nm to illuminate from the bottom of the glass tube so that the light intensity at the bottom of the glass tube is 50mW/cm ² . Irradiate for 20 minutes, turn the glass tube upside down and observe the polymerization of monomers in the glass tube. The test results are shown in Figure 8. The polymerization depth of the photosensitive liquid prepared in the present invention reached 7cm under the irradiation of a 455nm LED light source. This shows that the photoinitiator S-ECF of the present invention has good ability to initiate deep polymerization under the irradiation of LED light source.

Claims

The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization and its preparation method is characterized in that the structural formula of the compound is:

M stands for:

Wherein R 1 is selected from O, S, -NH-, C1-C20 alkylamino group; R 2 , R 3 , R 4 , R 5 and R 6 are the same or different, and are independently selected from hydrogen, halogen atoms, C1-C20 alkoxy group, C1-C20 alkylmercapto group, C1-C20 hydroxyalkyl group, hydroxyl group, dialkylamino group, -OCF 3 , -OC 6 H 5 , -COOH, -CHO, -NO 2 , -CN;

R 7 is selected from hydrogen, benzyl, C1-C20 alkyl, C1-C20 hydroxyalkyl,
The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization and its preparation method according to claim 1, wherein M is R 2, , R 3 , R 4 and R 5 are the same, and are independently selected as H; R 6 is selected from fluorine, hydrogen, methoxy and methylmercapto.
The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization according to any one of claims 1-2 and its preparation method, characterized in that R 7 is selected from C1- A C20 alkyl group and a C1-C20 hydroxyalkyl group are preferably a C1-C20 alkyl group, and more preferably an ethyl group.
The use of an arylvinyl α-carbonyl acid ester compound as a photoinitiator in LED photopolymerization according to any one of claims 1 to 3 and its preparation method, characterized in that the general compound of the compound The process is:

wherein M and R 7 are as defined in claim 1.
The use of an arylvinyl α-carbonyl ester compound as a photoinitiator in LED photopolymerization and its preparation method according to claim 4, characterized in that the preparation method of the compound includes the following steps:

In the step (a), the aromatic aldehyde and pyruvic acid are dissolved in alcohol and added to the reaction vessel, then an appropriate amount of alkali is dissolved in alcohol and added to the reactor, and stirred at 35°C for 6 hours; then, After distilling off the alcohol under reduced pressure, a crude product is obtained. The crude product is dissolved in water and washed three times with ethyl acetate; an appropriate amount of acid is added to the water phase to adjust the pH to 3, and extracted three times with ethyl acetate; the acetic acid is then distilled under reduced pressure. Ethyl ester to obtain intermediate product A;

In step (b), the dehydrating agent and catalyst are dissolved in alcohol and added to the reaction vessel. Then, the intermediate product A is dissolved in alcohol and dropped into the reaction vessel. Continue stirring for 2 hours; distill under reduced pressure. The alcohol is removed to obtain a crude product, which is separated using a chromatographic column to obtain the final product.
The use of an arylvinyl α-carbonyl ester compound as a photoinitiator in LED photopolymerization and its preparation method according to claim 5, characterized in that, in the step (a), the alcohol is selected from Methanol and ethanol; the base is selected from potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate; the molar ratio of aromatic aldehyde and pyruvic acid is 1:1-1:1.5, and the quality of the alcohol is 10-60 of the aromatic aldehyde. times, the molar amount of the base is 150%-300% of the aromatic aldehyde; in the step (b), the dehydrating agent is selected from dicyclohexylcarbodiimide, diisopropylcarbodiimide and 1-( 3-dimethylaminopropyl) 3-ethylcarbodiimide; the catalyst is selected from 4-dimethylaminopyridine, piperidine, 3-methylpiperidine, and triethylamine; the acid is selected from hydrochloric acid , sulfuric acid, acetic acid, boric acid; the molar amount of the catalyst is 2%-10% of the intermediate product A, the molar amount of the dehydrating agent is 100%-150% of the intermediate product A, and the molar amount of alcohol added is 100% of the intermediate product A. -150%.
A free radical photopolymerizable composition, characterized in that, based on the total weight of the composition, the composition contains the arylvinyl α-carbonyl acid ester compound, a hydrogen donor and a photocurable resin; or Monomer; the mass ratio of the aryl vinyl α-carbonyl ester compound, hydrogen donor and photocurable resin or monomer is 0.5:1.5:100; the hydrogen donor is selected from triethylamine, triethanolamine, diamine Ethanolamine, 4-dimethylaminoethyl benzoate; the photocurable resin is selected from epoxy (meth) acrylic resin, polyester (meth) acrylic resin, polyether (meth) acrylic resin, acrylic polyester resin One or more of (meth)acrylic resins, polyurethane (meth)acrylic resin; the monomer is one or more of monofunctional, difunctional or multifunctional (meth)acrylates or Various.
Application of the arylvinyl α-carbonyl acid ester compound described in claim 1 in colorless photopolymerization.
Application of the arylvinyl α-carbonyl acid ester compound described in claim 1 in deep photopolymerization.