A polymerizable one-component photoinitiator and its preparation method

Abstract

The present invention discloses a polymerizable single-component photoinitiator and its preparation method. It is prepared by Friedel-Crafts reaction, oxidation reaction and cyclization reaction using p-substituted benzoic acid and 4-mercapto phenylacetic acid. The polymerizable single-component thioxanthone molecule contains a photoinitiating component, a hydrogen donor and a double bond. It has high photoinitiating activity. The double bond in the molecule can undergo a polymerization reaction and be fixed in the polymer network, with low migration and low toxicity. The synthesis process is simple and suitable for industrial production. The photoinitiator of the present invention has a long initiation wavelength and a high matching degree with LED light, and can be used in the fields of coatings, adhesives, packaging, microelectronics, 3D printing, etc.

Description

Technical Field

[0001] The invention relates to the technical field of synthesis of photoinitiators, and in particular to a polymerizable single-component photoinitiator and a preparation method thereof. Background Art

[0002] Photopolymerization refers to the reaction of using light energy to initiate the polymerization of monomers. After being irradiated by an incident light source, the photoinitiator absorbs radiation energy to generate active fragments such as free radicals, cations or anions, which trigger the polymerization reaction of photosensitive materials (unsaturated acrylate monomers, cyclic monomers), thereby converting monomers into polymers. Therefore, although the amount of photoinitiator used in the photopolymerization system is small, it is a key component of the system. Thioxanthone is a widely used hydrogen-abstracting photoinitiator with strong ultraviolet absorption and high initiation efficiency. However, it needs to be used in conjunction with a hydrogen donor during its use. This can easily cause the migration of residual small molecule initiators and hydrogen donors after the photopolymerization reaction, thereby causing odor, toxicity, yellowing and other problems. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In order to overcome the shortcomings of the prior art, a polymerizable single-component photoinitiator is proposed, which is a polymerizable single-component thioxanthone initiator containing a double bond and a hydrogen donor, has excellent migration stability, and significantly reduced toxicity.

[0005] (II) Technical solution

[0006] The present invention is achieved through the following technical solution: The present invention proposes a polymerizable single-component photoinitiator, the structural formula of which is as follows:

[0007] ,

[0008] R1 is hydrogen or methyl; R2 is a straight or branched alkylene substituent containing 1 to 4 carbon atoms; R3 and R4 are independently one of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl and isobutyl.

[0009] A method for preparing a polymerizable single-component photoinitiator comprises the following steps:

[0010] Step 1: Dissolve 4-acetoxy-thiophenol in ethanol, stir evenly, add alkaline solution and methyl iodide, stir and react for a period of time at room temperature, spin dry the solvent, and add the crude product to the alkaline solution and dimethyl iodide.

[0011] The mixture was added to chloromethane, shaken and separated, the organic phase was collected and spin-dried to obtain a light yellow solid 4-acetoxy-thioanisole;

[0012] Step 2: Dissolve 4-vinylbenzoic acid in dichloromethane. After complete dissolution, add thionyl chloride dropwise under an ice bath, and stir the reaction at room temperature for a period of time. Then, evaporate the solvent to obtain 4-vinylbenzoyl chloride.

[0013] Step 3: Completely dissolve 4-vinylbenzoyl chloride in dichloromethane. Under nitrogen protection and an ice bath, add AlCl3, stir the reaction for a period of time, then add 4-acetoxy-benzenemethanethiol obtained in Step 1, and stir the reaction at room temperature for a period of time. Quench with an acid solution, add dichloromethane for extraction, and evaporate to obtain Intermediate I.

[0014] Step 4: Completely dissolve Intermediate I in ethyl acetate, then add an oxidizing agent dropwise at room temperature. After reacting for a period of time, evaporate the solvent to obtain Intermediate II.

[0015] Step 5: Completely dissolve Intermediate II in dichloromethane. Add zinc chloride under an ice bath and stir the reaction. Evaporate the solvent, add an acid solution to the system, shake well and separate the phases. Then, collect the organic phase and evaporate the solvent to obtain 2-acetoxy-6-vinylxanthone.

[0016] Step 6: Dissolve the obtained and mono-hydroxyalkanolamine in an organic solvent, then add a dehydrating agent, react at a certain temperature for a period of time, evaporate the solvent and mono-hydroxyalkanolamine, extract with water and an organic solvent, collect the organic phase and then evaporate to obtain the target product.

[0017] Step 7: Conduct performance testing on the target product.

[0018] Further, the structural general formula of the 4-acetoxy-thiophenol is as follows:

[0019] ,

[0020] The structural general formula of the mono-hydroxyalkanolamine is as follows:

[0021] ,

[0022] Further, the reaction equation is as follows:

[0023] ,

[0024] R1 is hydrogen or methyl; R2 is a straight-chain or branched-chain alkylene substituent containing 1-4 carbon atoms, and R3 and R4 are each independently one of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, and isobutyl.

[0025] Further, the base solution includes ammonia water, sodium hydroxide, potassium hydroxide, or sodium bicarbonate.

[0026] Further, the organic solvent includes methanol, ethanol, ethyl acetate, dichloromethane, chloroform, acetonitrile or acetone.

[0027] (III) Beneficial effects

[0028] The present invention has the following beneficial effects compared with the prior art:

[0029] A polymerizable single-component photoinitiator and a preparation method thereof mentioned in the present invention, the polymerizable single-component thioxanthone photoinitiator, which contains both a double bond and an amine hydrogen donor in the molecule. After photoinitiated photopolymerization, it can also undergo a polymerization reaction itself, improving the migration stability of the photoinitiator, reducing toxicity, yellowing, and odor; different photosensitive products with absorption wavelengths in the range of 300 nm - 450 nm can be obtained according to the selection of reactants, that is, it can be matched with LED light sources of different wavelengths for use; the photoinitiator and acrylate monomers have a high reaction rate without adding a co-initiator, and the double bond conversion rate can reach about 80% within 600 s. Description of the drawings

[0030] Figure 1 is the ultraviolet absorption spectrum of the product in Example 1 of the present invention.

[0031] Figure 2 is the real-time double bond conversion rate graph of the product in Example 1 of the present invention initiating the polymerization of monomer PEGDA.

[0032] Figure 3 is the chemical structural formula of the polymerizable single-component photoinitiator in the present invention. Specific embodiments

[0033] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following further details the present invention with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] The performance test method in the present invention is as follows:

[0035] Dissolve the synthesized product in an acetonitrile solvent with a molar concentration of 3*10-5 mol L-1, and perform ultraviolet spectrum testing to obtain its ultraviolet spectrum. Dissolve the synthesized product in the monomer, and perform real-time infrared testing with double salt tablets to obtain the real-time double bond conversion rate at different initiator concentrations. Examples

[0036] Dissolve 0.1 mol of 4-(4-acetoxyphenyl)thiophenol (0.1 mol, 18.4 g) in 100 ml of dichloromethane. After stirring evenly, add 0.5 g of NaOH (0.125 mol, 0.5 g) and iodomethane (7.39 ml), and stir the reaction at room temperature for 5 h. After rotary evaporation of the solvent, add the crude product to 1 M NaOH solution (100 ml) and dichloromethane (100 ml). After shaking well, perform liquid separation, collect the organic phase and rotary evaporate to obtain pale yellow solid 4-acetoxyphenyl methyl sulfide;

[0037] Dissolve 4-vinylbenzoic acid (0.1 mol, 14.8 g) in dichloromethane (50 ml). After complete dissolution, dropwise add thionyl chloride (14 ml) under ice bath, and stir the reaction at room temperature for 8 h. Rotary evaporate the solvent to obtain 4-vinylbenzoyl chloride;

[0038] Completely dissolve the obtained 4-vinylbenzoyl chloride (0.1 mol, 16.6 g) in 50 ml of dichloromethane. Under nitrogen protection and ice bath, add AlCl3 (0.0175 mol, 2.29 g), stir the reaction for 1 h, then add the 4-acetoxyphenyl methyl sulfide (0.12 mol, 21.84 g) obtained in Step 1, stir the reaction at room temperature for 8 h, quench with 100 ml of acid solution, add 100 ml of dichloromethane for extraction, and rotary evaporate to obtain intermediate I;

[0039] Completely dissolve intermediate I (0.1 mol, 31.2 g) in ethyl acetate (150 ml), then dropwise add sulfonyl chloride at room temperature. After reacting for 5 h, rotary evaporate the solvent to obtain intermediate II;

[0040] Completely dissolve intermediate II in dichloromethane (100 ml). Under ice bath, add zinc chloride (2.5 g) and stir the reaction for 5 h. Rotary evaporate the solvent, add acid solution to the system, shake well and separate the phases. Collect the organic phase and rotary evaporate the solvent to obtain 2-acetoxy-6-vinylxanthone;

[0041] Dissolve the obtained 2-acetoxy-6-vinylxanthone (0.1 mol, 29.6 g) and dimethylaminoethanol (0.2 mol, 1.78 g) in ethyl acetate (150 ml), then add dehydrating agent dicyclohexylcarbodiimide (4.5 g) and catalyst 4-dimethylaminopyridine (0.05 mol, 0.61 g), and react at 25 °C for 10 h. Rotary evaporate the solvent and dimethylaminoethanol, extract with water and ethyl acetate, collect the organic phase and rotary evaporate to obtain the target product.

[0042] Its 1H NMR spectrum is as follows: 1H NMR (400 MHz, Chloroform-d) δ 8.69 – 8.52 (m, 2H), 7.79 – 7.40 (m, 4H), 6.82 (dd, J = 17.6, 10.9 Hz, 1H), 5.90 (d, J = 17.4 Hz, 1H), 5.37 (d, J = 10.9 Hz, 1H), 4.45 (t, J = 5.3 Hz, 2H), 3.82 (s, 2H), 3.45 (t, J = 6.1 Hz, 2H), 2.98 (s, 6H).

[0043] Experimental results: As Figure 1 shown, the maximum absorption wavelength of the polymerizable monocomponent thioxanthone prepared in this example reaches 396 nm. As Figure 2 shown, under the condition of not adding a co-initiator, the double bond conversion rate of monomer PEGDA is 92% within 600 s.

[0044] The structural formula of the target product is as follows:

[0045] , Example

[0046] Dissolve 0.1 mol of 4-4-acetoxy-thiophenol (0.1 mol, 18.4 g) in 100 ml of dichloromethane. After stirring evenly, add 0.5 g of NaOH (0.125 mol, 0.5 g) and methyl iodide (7.39 ml), and stir and react at room temperature for 5 h. After evaporating the solvent, add the crude product to 1M NaOH solution (100 ml) and dichloromethane (100 ml), shake well and separate the layers. Collect the organic phase and evaporate to dryness to obtain light yellow solid 4-acetoxy-benzyl methyl sulfide.

[0047] Dissolve 4-vinylbenzoic acid (0.1 mol, 14.8 g) in dichloromethane (50 ml). After complete dissolution, dropwise add thionyl chloride (14 ml) under ice bath, and stir and react at room temperature for 8 h. Evaporate the solvent to obtain 4-vinylbenzoyl chloride.

[0048] Completely dissolve the obtained 4-vinylbenzoyl chloride (0.1 mol, 16.6 g) in 50 ml of dichloromethane. Under nitrogen protection and ice bath, add AlCl3 (0.0175 mol, 2.29 g), stir and react for 1 h, then add the 4-acetoxy-benzyl methyl sulfide (0.12 mol, 21.84 g) obtained in step 1, stir and react at room temperature for 8 h, quench with 100 ml of acid solution, add 100 ml of dichloromethane for extraction, and evaporate to dryness to obtain intermediate I.

[0049] The intermediate I (0.1 mol, 31.2 g) was completely dissolved in 150 ml of ethyl acetate, and then sulfonyl chloride was added dropwise at room temperature. After reacting for 5 h, the solvent was evaporated to dryness to obtain intermediate II.

[0050] The intermediate II was completely dissolved in dichloromethane (100 ml). 2.5 g of zinc chloride was added under an ice bath and the mixture was stirred and reacted for 5 h. The solvent was evaporated to dryness. An acid solution was added to the system. After shaking and phase separation, the organic phase was collected and the solvent was evaporated to dryness to obtain 2-acetyl-6-vinylxanthone.

[0051] The obtained 2-acetyl-6-vinylxanthone (0.1 mol, 29.6 g) and 1-methyl-2-ethyl ethanolamine (0.15 mol, 10.3 g) were dissolved in dichloromethane (100 ml). Then dehydrating agent dicyclohexylcarbodiimide (4.5 g) and catalyst 4-dimethylaminopyridine (0.05 mol, 0.61 g) were added. The reaction was carried out at 25 °C for 8 h. Dichloromethane and 1-methyl-2-ethyl ethanolamine were evaporated to dryness. Extraction was carried out with water and ethyl acetate. After collecting the organic phase, it was evaporated to dryness to obtain the target product.

[0052] Its 1H NMR spectrum is as follows: 1H NMR (400 MHz, Chloroform-d) δ 8.69 – 8.52 (m, 2H), 7.79 – 7.40 (m, 4H), 6.82 (dd, J = 17.6, 10.9 Hz, 1H), 5.90 (d, J = 17.4 Hz, 1H), 5.37 (d, J = 10.9 Hz, 1H), 4.45 (t, J = 5.3 Hz, 2H), 3.82 (s, 2H), 2.74 – 2.62 (m, 4H), 2.30 (s, 3H), 1.12 (t, J = 5.9 Hz, 3H).

[0053] Experimental results: The maximum absorption wavelength of the polymerizable photoinitiator prepared in this example reached 400 nm. Without adding a co-initiator, the double bond conversion rate of monomer PEGDA within 600 s was 82%.

[0054] The structure of the target product is as follows:

[0055] , Example

[0056] Dissolve 0.1 mol of 4-(4-acetoxyphenyl)thiophenol (0.1 mol, 18.4 g) in 100 ml of dichloromethane. After stirring evenly, add 0.5 g of NaOH (0.125 mol, 0.5 g) and iodomethane (7.39 ml), and stir the reaction at room temperature for 5 h. After evaporating the solvent, add the crude product to 1 M NaOH solution (100 ml) and dichloromethane (100 ml), shake well and separate the layers. Collect the organic phase and evaporate it to dryness to obtain light yellow solid 4-acetoxyphenyl methyl sulfide.

[0057] Dissolve 4-vinylbenzoic acid (0.1 mol, 14.8 g) in dichloromethane (50 ml). After complete dissolution, dropwise add thionyl chloride (14 ml) under ice bath, and stir the reaction at room temperature for 8 h. Evaporate the solvent to obtain 4-vinylbenzoyl chloride.

[0058] Completely dissolve the obtained 4-vinylbenzoyl chloride (0.1 mol, 16.6 g) in 50 ml of dichloromethane. Under nitrogen protection and ice bath, add AlCl3 (0.0175 mol, 2.29 g), stir the reaction for 1 h, then add 4-acetoxyphenyl methyl sulfide (0.12 mol, 21.84 g) obtained in step 1, and stir the reaction at room temperature for 8 h. Quench with 100 ml of acid solution, add 100 ml of dichloromethane for extraction, and evaporate to dryness to obtain intermediate I.

[0059] Completely dissolve intermediate I (0.1 mol, 31.2 g) in 150 ml of ethyl acetate, then dropwise add sulfonyl chloride at room temperature. After reacting for 5 h, evaporate the solvent to obtain intermediate II.

[0060] Completely dissolve intermediate II in dichloromethane (100 ml). Under ice bath, add 2.5 g of zinc chloride and stir the reaction for 5 h. Evaporate the solvent, add acid solution to the system, shake well and separate the layers. Collect the organic phase and evaporate the solvent to obtain 2-acetoxy-6-vinylxanthone.

[0061] Dissolve the obtained 2-acetoxy-6-vinylxanthone (0.1 mol, 29.6 g) and dipropylethanolamine (0.15 mol, 14.4 g) in dichloromethane (100 ml), then add dehydrating agent dicyclohexylcarbodiimide (4.5 g) and catalyst 4-dimethylaminopyridine (0.05 mol, 0.61 g), and react at 25 °C for 8 h. Evaporate the solvent and dipropylethanolamine, extract with water and ethyl acetate, collect the organic phase and evaporate to dryness to obtain the target product.

[0062] Its 1H NMR spectrum is as follows: 1H NMR (400 MHz, Chloroform-d) δ 8.69 – 8.52 (m, 2H), 7.79 – 7.40 (m, 4H), 6.82 (dd, J = 17.6, 10.9 Hz, 1H), 5.90 (d, J = 17.4 Hz, 1H), 5.37 (d, J = 10.9 Hz, 1H), 4.45 (t, J = 5.3 Hz, 2H), 3.82 (s, 2H), 3.08 (t, J = 6.1 Hz, 2H), 2.58 (t, J = 7.6 Hz, 4H), 1.54 (m, 4H), 0.99 (t, J = 6.8 Hz, 6H).

[0063] Experimental results: The maximum absorption wavelength of the polymerizable photoinitiator prepared in this example reaches 392 nm. Without adding a co-initiator, the double bond conversion rate of monomer PEGDA is 80% within 600 s, showing a photo-bleaching effect.

[0064] The structure of the target product is as follows:

[0065] , Example

[0066] Dissolve 0.1 mol of 4-acetylthiophenol (0.1 mol, 18.4 g) in 100 ml of dichloromethane. After stirring evenly, add 0.5 g of NaOH (0.125 mol, 0.5 g) and methyl iodide (7.39 ml), and stir and react at room temperature for 5 h. After evaporating the solvent, add the crude product to 1 M NaOH solution (100 ml) and dichloromethane (100 ml). After shaking well, separate the layers, collect the organic phase and evaporate it to dryness to obtain light yellow solid 4-acetyl-benzylthioether.

[0067] Dissolve 4-vinylbenzoic acid (0.1 mol, 14.8 g) in dichloromethane (50 ml). After complete dissolution, dropwise add thionyl chloride (14 ml) under ice bath, and stir and react at room temperature for 8 h. Evaporate the solvent to obtain 4-vinylbenzoyl chloride.

[0068] Completely dissolve the obtained 4-vinylbenzoyl chloride (0.1 mol, 16.6 g) in 50 ml of dichloromethane. Under nitrogen protection and ice bath, add AlCl3 (0.0175 mol, 2.29 g), stir and react for 1 h, then add the 4-acetyl-benzylthioether obtained in step 1 (0.12 mol, 21.84 g), stir and react at room temperature for 8 h, quench with 100 ml of acid solution, add 100 ml of dichloromethane for extraction, and evaporate to dryness to obtain intermediate I.

[0069] The intermediate I (0.1 mol, 31.2 g) was completely dissolved in 150 ml of ethyl acetate, and then sulfonyl chloride was added dropwise at room temperature. After reacting for 5 h, the solvent was evaporated to dryness to obtain intermediate II.

[0070] The intermediate II was completely dissolved in dichloromethane (100 ml). 2.5 g of zinc chloride was added under an ice bath and stirred for 5 h. The solvent was evaporated to dryness. An acid solution was added to the system. After shaking and phase separation, the organic phase was collected and the solvent was evaporated to dryness to obtain 2-acetyl-6-vinylxanthone.

[0071] The obtained 2-acetyl-6-vinylxanthone (0.1 mol, 29.6 g) and diethylethanolamine (0.2 mol, 23.4 g) were dissolved in dichloromethane (100 ml). Then, dehydrating agent dicyclohexylcarbodiimide (4.5 g) and catalyst 4-dimethylaminopyridine (0.05 mol, 0.61 g) were added. The reaction was carried out at 25 °C for 8 h. The solvent and diethylethanolamine were evaporated to dryness. Extraction was carried out with water and ethyl acetate. After collecting the organic phase, the solvent was evaporated to dryness to obtain the target product.

[0072] Its 1H NMR spectrum is as follows: 1H NMR (400 MHz, Chloroform-d) δ 8.69 – 8.52 (m, 2H), 7.79 – 7.40 (m, 4H), 6.82 (dd, J = 17.6, 10.9 Hz, 1H), 5.90 (d, J = 17.4 Hz, 1H), 5.37 (d, J = 10.9 Hz, 1H), 4.45 (t, J = 5.3 Hz, 2H), 3.82 (s, 2H), 3.09 – 3.02 (m, 6H), 1.24 (t, J = 7.2 Hz, 6H).

[0073] Experimental results: The maximum absorption wavelength of the polymerizable photoinitiator prepared in this example reached 394 nm. Without adding a co-initiator, the double bond conversion rate of monomer PEGDA within 600 s was 83%, and it had a photo-bleaching effect.

[0074] The structure of the target product is as follows:

[0075] ,

[0076] Finally, the synthetic products obtained in Examples 1 - 4 were added to the PEGDA monomer at a mass fraction of 0.01% and numbered 1, 2, 3, 4 respectively. After curing under a 365 nm LED light source, the cured bulk polymers were soaked in acetonitrile for 24 h and ultrasonically treated for 2 h. The extraction solution was taken to measure the ultraviolet spectrum.

[0077] Experimental results: As shown in the following table, the leaching solution has no ultraviolet absorption in the wavelength range of 250 nm - 450 nm, that is, there is no migration of small molecules in the initiator system of this initiator.

[0078] Number 1 2 3 4 Maximum UV absorption in the wavelength range of 250nm - 500nm 0 0 0 0

[0079] The above-described embodiments are merely descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope of the present invention. The technical content claimed by the present invention has been fully recorded in the claims.

Claims

1. A polymerizable one-component photoinitiator, characterized in that: Its structural formula is as follows: ， R1 is hydrogen or methyl; R2 is a straight-chain or branched-chain alkylene substituent containing 1-4 carbon atoms, and R3 and R4 are each independently one of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, and isobutyl.

2. The preparation method of a polymerizable single-component photoinitiator according to claim 1, wherein: It includes the following steps: Step 1: Dissolve 4-acetylthiophenol in ethanol. After stirring evenly, add an alkali solution and methyl iodide. Under normal temperature conditions, stir and react for a period of time. After evaporating the solvent, add the crude product to the alkali solution and dichloromethane. After shaking well, perform liquid separation, collect the organic phase and evaporate it to dryness to obtain light yellow solid 4-acetyl-benzenemethanethiol; Step 2: Dissolve 4-vinylbenzoic acid in dichloromethane. After complete dissolution, dropwise add thionyl chloride under ice bath, and stir and react at room temperature for a period of time. Evaporate the solvent to obtain 4-vinylbenzoyl chloride; Step 3: Completely dissolve 4-vinylbenzoyl chloride in dichloromethane, add AlCl3 under nitrogen protection and ice bath, stir and react for a period of time, add 4-acetyl-benzenemethanethiol obtained in Step 1, stir and react at room temperature for a period of time, quench with an acid solution, add dichloromethane for extraction, and spin dry to obtain ; Step 4: Completely dissolve in ethyl acetate, then add an oxidizing agent dropwise at room temperature. After reacting for a period of time, spin-dry the solvent to obtain ; Step 5: Completely dissolve in dichloromethane, add zinc chloride under ice bath and stir for reaction. Rotate to dry the solvent, add acid solution to the system, shake well and separate the phases. Then collect the organic phase and rotate to dry the solvent to obtain 2-acetyl-6-vinylxanthone; Step 6: Dissolve the obtained and mono-hydroxy alkanolamine in an organic solvent, then add a dehydrating agent, react for a period of time at a certain temperature, spin-dry the solvent and mono-hydroxy alkanolamine, extract with water and an organic solvent, and spin-dry the collected organic phase to obtain the target product; Step 7: Conduct performance testing on the target product; The general structural formula of 4-acetylthiophenol is as follows: ， The general structural formula of mono-hydroxyalkanolamine is as follows: ， R1-R4 are defined as in claim 1.

3. The preparation method of a polymerizable single-component photoinitiator according to claim 2, characterized in that: The reaction equation is as follows: ， R1 is hydrogen or methyl; R2 is a straight-chain or branched-chain alkylene substituent containing 1-4 carbon atoms, and R3 and R4 are each independently one of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, and isobutyl.

4. The preparation method of a polymerizable single-component photoinitiator according to claim 2, characterized in that: The alkali solution includes ammonia water, sodium hydroxide, potassium hydroxide or sodium bicarbonate.

5. The preparation method of a polymerizable single-component photoinitiator according to claim 2, characterized in that: The organic solvent includes methanol, ethanol, ethyl acetate, dichloromethane, chloroform, acetonitrile or acetone.

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