Process for the preparation of a class of aryl alpha-keto photoinitiators

Abstract

The application discloses a preparation method of aryl alpha ketone photoinitiator, and relates to the field of organic synthesis. Specifically, the method comprises the following steps: taking a compound shown in formula (I) or formula (II), morpholine or piperidine as a reactant, taking potassium carbonate as an acid-binding agent, and performing a reaction under the action of a catalyst; wherein the catalyst is a porous SiO2 loaded palladium-copper composite catalyst, the average particle size of the catalyst is 180-250 nm, and the weight ratio of palladium to copper is (92-98):(2-8). The application avoids using fluorine-containing compounds as reactants, thus no fluorine-containing wastewater is generated, energy is saved, the environment is protected, and the cost is low. In addition, the reaction condition is mild, and the yield is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of organic synthesis, in particular to a preparation method of aryl alpha ketone photoinitiator. BACKGROUND

[0002] The aryl alpha ketone photoinitiator mainly includes photoinitiator 369, photoinitiator 379 and photoinitiator 389, and the specific structural formula is as follows:

[0003]

[0004] The main synthesis route of the aryl alpha ketone photoinitiator at present is to take fluorobenzene as a starting material, to obtain 4-fluorobutyrophenone under the catalysis of anhydrous aluminum chloride, to obtain a bromide through bromination, to obtain an aminated substituent through dimethylamine amination of the bromide, to obtain a quaternary ammonium salt through the reaction of the aminated substituent with chlorobenzene, to obtain a rearrangement compound through catalytic rearrangement of the quaternary ammonium salt under alkaline conditions, and to obtain the photoinitiator 369 / 379 / 389 through substitution reaction of the rearrangement compound with morpholine or piperidine. However, the use of fluorobenzene will produce fluorine-containing ion wastewater, which is difficult to handle and has high cost. In addition, the reaction condition is harsh and the yield is low in the morpholine substitution process. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a preparation method of aryl alpha ketone photoinitiator, which can effectively reduce the preparation temperature and pressure of aryl alpha ketone photoinitiator, improve the yield, and not produce fluorine-containing wastewater.

[0006] In order to solve the technical problem of the present application, the present application provides a preparation method of aryl alpha ketone photoinitiator, which comprises the step of taking a compound represented by formula (I) or formula (II), morpholine or piperidine as a reactant, taking potassium carbonate as an acid-binding agent, and reacting under the action of a catalyst.

[0007]

[0008] (I)

[0009]

[0010] (II)

[0011] The catalyst is a porous SiO2 supported palladium-copper composite catalyst, the average particle size is 180-250 nm, and the weight ratio of copper to palladium is 92:2-98:8.

[0012] As an improvement of the above technical solution, in the step of taking a compound represented by formula (I) or formula (II), morpholine or piperidine as a reactant, taking potassium carbonate as an acid-binding agent, and reacting under the action of a catalyst, water is used as a solvent.

[0013] As the improvement of the above technical scheme, in the step of taking the compound shown in formula (I) or formula (II), morpholine or piperidine as the reactant, taking potassium carbonate as the acid-binding agent, and taking the catalyst to react, the reaction temperature is 60-70 DEG C, and the reaction time is 12-15 h.

[0014] As the improvement of the above technical scheme, the aryl alpha ketone photoinitiator is photoinitiator 369, and the preparation method comprises the step of taking the compound shown in formula (I) and morpholine as the reactant, taking potassium carbonate as the acid-binding agent, taking water as the solvent, and taking the catalyst to react; or

[0015] The aryl alpha ketone photoinitiator is photoinitiator 379, and the preparation method comprises the step of taking the compound shown in formula (II) and morpholine as the reactant, taking potassium carbonate as the acid-binding agent, taking water as the solvent, and taking the catalyst to react; or

[0016] The aryl alpha ketone photoinitiator is photoinitiator 389, and the preparation method comprises the step of taking the compound shown in formula (I) and piperidine as the reactant, taking potassium carbonate as the acid-binding agent, taking water as the solvent, and taking the catalyst to react.

[0017] As the improvement of the above technical scheme, the step of taking the reaction product to purify is further included;

[0018] The step of taking the reaction product to purify comprises the step of dispersing the reaction product into ethanol, then heating to 70-80 DEG C, keeping warm for 1-4 h, and then gradiently cooling to 0-5 DEG C, so that the reaction product recrystallizes.

[0019] As the improvement of the above technical scheme, the preparation method of the catalyst comprises:

[0020] (1) providing or preparing carbon nanospheres;

[0021] (2) dispersing the carbon nanospheres in water to obtain dispersion liquid A with a concentration of 1-5 g / L; dispersing copper chloride in the dispersion liquid A to obtain dispersion liquid B with a concentration of 3-10 g / L; uniformly mixing the dispersion liquid A and the dispersion liquid B, and then performing solid-liquid separation to obtain intermediate A; wherein the dispersion liquid A is sulfuric acid solution, hydrochloric acid solution or nitric acid solution;

[0022] (3) dispersing the intermediate A in water to obtain dispersion liquid C with a concentration of 5-12 g / L, and then sequentially adding a divalent palladium salt solution and a sodium acetate solution, mixing for 3-8 h, and then performing solid-liquid separation to obtain intermediate B; wherein the Pd 2+The concentration of the glucose is 120-150 g / L, the concentration of the sodium acetate is 0.03-0.2 mol / L, the concentration of the sodium acetate in the sodium acetate solution is 0.1-0.5 mol / L, the volume ratio of the divalent palladium salt solution to the dispersion liquid C is 0.1:10-0.3:10, and the volume ratio of the sodium acetate solution to the dispersion liquid C is 0.2:1-0.5:1.

[0023] (4) mixing the intermediate B, a dispersant B, CTAB and NH3·H2O uniformly to obtain a dispersion liquid D; wherein the dispersant B is one or more of water, ethanol or methanol, the concentration of the intermediate B in the dispersion liquid D is 2-10 g / L, the concentration of CTAB is 1-3 g / L, and the concentration of NH3·H2O is 0.5-2 mol / L;

[0024] (5) adding tetraethyl silicate to the dispersion liquid D, and after stirring at 20-40 ℃ for 2-12 h, performing solid-liquid separation to obtain an intermediate C; wherein the volume ratio of the dispersion liquid D to the tetraethyl silicate is 400:1-550:1;

[0025] (6) calcining the intermediate C in an inert atmosphere at 350-450 ℃ for 1-4 h, and then calcining the intermediate C in an oxygen-containing atmosphere at 350-450 ℃ for 2-8 h to obtain a catalyst product.

[0026] As an improvement of the above technical solution, in step (6), the intermediate is calcined in a nitrogen atmosphere at 390-420 ℃ for 1.5-2.2 h, and then calcined in an air atmosphere at 350-380 ℃ for 5-7 h to obtain a catalyst product based on hollow silicon nanocapsule loading.

[0027] As an improvement of the above technical solution, in step (1), the glucose is dispersed in water to obtain a dispersion liquid E with a concentration of 120-150 g / L, and then subjected to hydrothermal reaction at 200-300 ℃ for 2-5 h, and after solid-liquid separation, carbon nanospheres are obtained.

[0028] As an improvement of the above technical solution, in step (2), the dispersant A is a hydrochloric acid solution with a concentration of 0.01-0.1 mol / L.

[0029] In step (3), the divalent palladium salt solution is a PdCl2 solution or a palladium acetate solution; the concentration of Pd 2+ in the divalent palladium salt solution is 0.04-0.1 mol / L.

[0030] As an improvement of the above technical solution, in step (4), the dispersant B is a mixture of water and ethanol, and the volume ratio of water to ethanol is 1.5:1-3:1.

[0031] The implementation of the present application has the following beneficial effects:

[0032] The preparation method of the aryl alpha ketone photoinitiator of the present application uses the compound shown in formula (I) or formula (II), morpholine or piperidine as the reactant, potassium carbonate as the acid binding agent, and the reaction is carried out under the action of the catalyst; wherein the catalyst is a porous SiO2 loaded palladium copper composite catalyst, the average particle size is 180-250 nm, and the weight ratio of palladium to copper is (92-98):(2-8). Based on the above-mentioned composite catalyst, the compound shown in formula (I) or formula (II) is used as the reactant in the present application, so that the use of fluorine-containing compounds is avoided, thus no fluorine-containing wastewater is generated, energy saving and environmental protection are achieved, and the cost is low. Further, the reaction can use water as the solvent, which also reduces the cost. Further, the reaction of the present application can be carried out at 60-70 DEG C, the reaction condition is mild, and the yield is high. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 It is a scanning electron microscope graph of the carbon nano powder in Example 1;

[0034] Fig. 2 It is a scanning electron microscope graph of the palladium carbon nano powder in Example 1;

[0035] Fig. 3 It is a scanning electron microscope graph of the catalyst finished product in Example 1. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with the drawings and specific embodiments.

[0037] The present application discloses a preparation method of a kind of aryl alpha ketone photoinitiator, it is characterized in that, including with the compound shown in formula (I) or formula (II), morpholine or piperidine as reactant, potassium carbonate is used as acid binding agent, and the step of reaction under the action of catalyst;

[0038]

[0039] (I)

[0040]

[0041] (II)

[0042] Wherein the catalyst is a porous SiO2 loaded palladium copper composite catalyst, the inventor has unexpectedly found that by introducing the SiO2 loaded palladium copper composite catalyst, the reaction based on the compound shown in formula (I) and formula (II) can be effectively promoted to become aryl alpha ketone photoinitiator. If the catalyst is not added or other types of catalysts commonly used in the art (such as copper catalyst, copper-nickel composite catalyst, copper-cobalt composite catalyst, etc.) are introduced, the reaction cannot be carried out.

[0043] Specifically, the average particle size of the porous SiO2 supported palladium-copper composite catalyst is 180-250 nm, and examples include 190 nm, 200 nm, 210 nm, 220 nm or 230 nm, but are not limited thereto. The weight ratio of copper to palladium in the catalyst is (92-98):(2-8), and examples include 92:8, 93:7, 94:6, 96:4 or 92:8, but are not limited thereto.

[0044] Preferably, in some embodiments of the present application, water is used as the solvent in the above reaction step. Using water as the solvent not only reduces the cost of the reaction, but also simplifies the subsequent processing steps. Specifically, the amount of water used is 3-5 times the weight of the compound of formula (I) or formula (II).

[0045] Preferably, in some embodiments of the present application, the reaction temperature in the above reaction step is 55-70°C, and examples include 58°C, 59°C, 61°C, 63°C, 65°C or 67°C, preferably 60-70°C. The reaction time is 10-18 h, and examples include 11 h, 13 h, 14.5 h, 16 h or 17.5 h, but are not limited thereto. Preferably, the reaction time is 12-15 h.

[0046] Preferably, in some embodiments of the present application, the aryl α-ketone photoinitiator is photoinitiator 369, and the preparation method comprises the step of reacting the compound of formula (I) and morpholine as reactants, using potassium carbonate as an acid-binding agent, water as a solvent, and a catalyst.

[0047]

[0048] In other embodiments of the present application, the aryl α-ketone photoinitiator is photoinitiator 379, and the preparation method comprises the step of reacting the compound of formula (II) and morpholine as reactants, using potassium carbonate as an acid-binding agent, water as a solvent, and a catalyst.

[0049]

[0050] In other embodiments of the present application, the aryl α-ketone photoinitiator is photoinitiator 389, and the preparation method comprises the step of reacting the compound of formula (I) and piperidine as reactants, using potassium carbonate as an acid-binding agent, water as a solvent, and a catalyst.

[0051]

[0052] Preferably, in some embodiments of the present application, the step of removing the reactants and catalyst to obtain the reaction product is further included. Specifically, dichloromethane and water are added to the reaction system after the reaction is completed, and after sufficient stirring, the solid-liquid separation is performed, the solid phase is the catalyst, and the liquid phase is allowed to stand to obtain an organic phase and an aqueous phase, the organic phase is dried and concentrated to obtain the reaction product.

[0053] Preferably, in some embodiments of the present application, the step of purifying the reaction product obtained in the above reaction step is further included, and specifically includes the step of dispersing the reaction product into ethanol, then heating to 70-80°C, maintaining for 1-4 h, and then gradiently cooling to 0-5°C to recrystallize the reaction product. In the step of gradiently cooling, the cooling rate is 5-15°C / h.

[0054] Specifically, in some embodiments of the present application, the catalyst is prepared by the following method:

[0055] (1) providing or preparing carbon nanospheres;

[0056] The carbon nanospheres are solid carbon nanospheres, and the average particle size is 150-300 nm. The carbon nanospheres with such a particle size can be effectively decomposed in the subsequent treatment process, thereby forming hollow and porous silicon nanocapsules and improving the reaction activity. If the particle size is too small, the amount of loaded Pd metal and Cu metal is too small, and the activity is low. If the particle size is too large, the decomposition is not complete in the subsequent heat treatment process, the pore structure is small, and the reaction activity is low. Preferably, the average particle size of the carbon nanospheres is 180-220 nm, and more preferably 190-205 nm.

[0057] Specifically, in one embodiment of the present application, the carbon nanospheres can be prepared by the following method: dispersing glucose in water to obtain a dispersion E with a concentration of 120-150 g / L, and then hydrothermally reacting at 200-300°C for 2-5 h. After solid-liquid separation, the carbon nanospheres are obtained.

[0058] Preferably, after the solid-liquid separation, the obtained product is sequentially rinsed with water and ethanol for 2-3 times, and then dried to obtain the carbon nanospheres.

[0059] (2) dispersing the carbon nanospheres in water to obtain a dispersion A; dispersing copper chloride in the dispersion A to obtain a dispersion B; and mixing the dispersion A and the dispersion B uniformly, and then performing solid-liquid separation to obtain an intermediate A;

[0060] The concentration of the carbon nanospheres in the dispersion A is 1-5 g / L, preferably 1-3 g / L, and more preferably 1.5-3 g / L.

[0061] The concentration of the copper chloride in the dispersion is 3-10 g / L, preferably 4-8 g / L, and more preferably 4-6 g / L.

[0062] wherein the dispersant A is a sulfuric acid solution, a hydrochloric acid solution or a nitric acid solution, but is not limited thereto. The concentration of H + in the dispersant A is 0.01-0.2 mol / L, preferably 0.01-0.1 mol / L, and more preferably 0.01-0.05 mol / L. Preferably, in one embodiment of the present application, the dispersant A is a hydrochloric acid solution.

[0063] Specifically, the dispersion A and the dispersion B are mixed and continuously stirred at 20-40°C for 5-20 min, then solid-liquid separation is performed, the obtained precipitate is washed with water for 2-5 times, and intermediate A is obtained.

[0064] (3) The intermediate A is dispersed in water to obtain dispersion C, a divalent palladium salt solution and a sodium acetate solution are sequentially added, and after mixing for 3-8 h, solid-liquid separation is performed to obtain intermediate B;

[0065] wherein the concentration of the intermediate A in the dispersion C is 5-12 g / L, preferably 6-10 g / L, and more preferably 6-9 g / L.

[0066] wherein the divalent palladium salt solution is a PdCl2 aqueous solution or a palladium acetate aqueous solution, but is not limited thereto. The concentration of Pd 2+ in the divalent palladium salt solution is 0.03-0.2 mol / L, preferably 0.03-0.1 mol / L, and more preferably 0.03-0.08 mol / L.

[0067] The volume ratio of the divalent palladium salt solution to the dispersion C is 0.1:10-0.3:10, and is exemplarily 0.12:10, 0.15:10, 0.2:10, 0.23:10 and 0.25:10, but is not limited thereto.

[0068] wherein the sodium acetate solution is a sodium acetate aqueous solution, and the concentration of sodium acetate is 0.1-0.5 mol / L, preferably 0.1-0.3 mol / L, and more preferably 0.15-0.3 mol / L.

[0069] The volume ratio of the sodium acetate solution to the dispersion C is 0.2:1-0.5:1.

[0070] Preferably, in one embodiment of the present application, the divalent palladium salt solution is first added to the dispersion C, and stirring is performed at 20-40°C for 3-8 h, then the sodium acetate solution is added, stirring and mixing are performed at 20-40°C for 5-10 min, then solid-liquid separation is performed, and the obtained product is washed with water for 3-5 times and dried, and intermediate B is obtained.

[0071] (4) The intermediate B, the dispersant B, CTAB and NH3·H2O are uniformly mixed to obtain dispersion D;

[0072] The dispersant B is one or more of water, ethanol or methanol, but is not limited thereto. Preferably, it is a mixture of water and ethanol, and the volume ratio of water to ethanol is 1.5:1 to 3:1.

[0073] In the dispersion D, the concentration of the intermediate B is 2 to 10 g / L, the concentration of CTAB is 1 to 3 g / L, and the concentration of NH3·H2O is 0.5 to 2 mol / L.

[0074] (5) Tetraethyl silicate is added to the dispersion D, and after stirring at 20 to 40℃ for 2 to 12 hours, solid-liquid separation is performed to obtain the intermediate C;

[0075] The volume ratio of the dispersion D to tetraethyl silicate is 400:1 to 550:1. Tetraethyl silicate undergoes hydrolysis and polycondensation, and the formed SiO2 nanoparticles are coated on the surface of the intermediate C.

[0076] Preferably, after the solid-liquid separation, the product is rinsed with water and ethanol each for 3 times, to obtain the intermediate C.

[0077] (6) The intermediate C is calcined at 350 to 450℃ for 1 to 4 hours in an inert atmosphere, and then calcined at 350 to 450℃ for 2 to 8 hours in an oxygen-containing atmosphere, to obtain the finished catalyst.

[0078] The inert atmosphere can be an inert gas atmosphere or a nitrogen atmosphere, but is not limited thereto. Preferably, it is a nitrogen atmosphere. The calcination temperature in the inert atmosphere is preferably 390 to 420℃, and the calcination time is preferably 1.5 to 2.2 hours.

[0079] The oxygen-containing atmosphere is an oxygen atmosphere or an air atmosphere, but is not limited thereto. Preferably, it is an air atmosphere. The preferred calcination temperature in the oxygen-containing atmosphere is 350 to 380℃, and the calcination time is 5 to 7 hours.

[0080] After the above calcination, the average particle size of the obtained finished catalyst is 180 to 250 nm, and the catalyst has a coating structure, and the coating layer has multiple pores, which makes the reactants enter the catalyst during the preparation of the aryl α-ketone photoinitiator, effectively reduces the reaction temperature and the reaction pressure, and improves the yield.

[0081] The present application is further described below with specific examples:

[0082] Example 1

[0083] The present example provides a preparation method of a photoinitiator 369, which comprises:

[0084] Put 4.1 g of 369 raw material (a compound as shown in formula (I)) into 16 g of water, 1.8 g of potassium carbonate, 2.3 g of morpholine, and 0.04 g of catalyst into a reaction bottle in turn, replace the reactor with nitrogen, heat to 65℃ for 12-13 hours, and control the HPLC detection of the raw material to be less than or equal to 0.5%. Then, 100 ml of dichloromethane and 50 ml of water are added, the catalyst is removed by stirring and filtration, the organic phase is washed with water twice, dried with anhydrous sodium sulfate, and concentrated to obtain 4.76 g of yellow solid with a purity of greater than or equal to 89%. The solid is added to 20 ml of ethanol, heated to 75℃ for 2 hours, and then cooled to 3℃ at a cooling rate of 10℃ / h to precipitate the solid. The solid is filtered to obtain 3.8 g of yellow solid with a purity of greater than or equal to 98%.

[0085] The specific preparation method of the catalyst is as follows:

[0086] Dissolve 20 g of glucose in 150 mL of water to form a clear solution, and then transfer it to a 200 mL sealed hydrothermal kettle. Keep it at high temperature and high pressure at 210℃ for 4 hours. Centrifugal separation, washing with water and ethanol three times, and drying in a 100ºC oven to obtain carbon nanometer powder. Disperse 0.2 g of carbon nanometer balls in 100 mL of distilled water, stir for 10 min, and use as solution A. Dissolve 0.2 g of copper chloride in 40 mL of 0.02 mol / L hydrochloric acid solution as solution B. Mix solutions A and B and stir for 10 min. Then centrifuge the suspension. After washing five times with distilled water, disperse the precipitate in 50 mL of distilled water. Add 750µL of 0.05 mol / L PdCl2 aqueous solution. After stirring for 5h, add 20 mL of 0.2 mol / L sodium acetate aqueous solution. After centrifugation, wash five times with distilled water, and dry at 80ºC for 12h to obtain palladium carbon nanometer powder.

[0087] Disperse the obtained palladium carbon nanometer powder in a solution containing 50 mL of water, 25 mL of ethanol, 2 g / L of CTAB, and 1 mol / L of NH3·H2O at a concentration of 6 g / L, and ultrasonic treat for 20 min. Then add 0.15 mL of TEOS and stir for 10 h. After centrifugation, collect the precipitate, wash it with distilled water and ethanol three times, and dry it at 80ºC for 6h. Then calcine it at 400ºC under nitrogen protection for 2h, and then in air at 370℃ for 6h.

[0088] The carbon nanometer powder, palladium carbon nanometer powder, and catalyst product in Example 1 were analyzed by scanning electron microscopy, and the specific results are shown in Figs. 1-3 Fig. 1 is the scanning electron micrograph of the carbon nanometer powder, and from Fig. 1 it can be seen that the carbon nanometer powder is a sphere with very high uniformity, and the average particle size is about 200 nm; Fig. 2 ​is a scanning electron microscope image of palladium carbon nanometer powder, from Fig. 2 As can be seen from the figure, some Pd and Cu are loaded on the periphery of the carbon nanometer powder. Fig. 3 is a scanning electron microscope image of the catalyst product, from Fig. 3 As can be seen from the figure, a layer of substance is attached to the outside of the sphere, which is porous SiO2.

[0089] Example 2

[0090] The present example provides a preparation method of a photoinitiator 379, which comprises:

[0091] 3.3g of 379 raw material (a compound as shown in formula (II)) is added into 14g of water, 1.4g of potassium carbonate, 1.8g of morpholine, and 0.03g of catalyst (the same as in Example 1) is sequentially added into a reaction bottle, the reactor is sealed by nitrogen replacement, and the temperature is raised to 70°C for 12-13 hours of reaction, the raw material is detected by HPLC to be ≤0.5%, 80ml of dichloromethane and 30ml of water are added, the catalyst is removed by stirring and filtration, the organic phase is washed with water twice, dried with anhydrous sodium sulfate, concentrated to obtain 3.9g of yellow solid, and the purity is ≥93%. The solid is added into 15ml of ethanol, the temperature is raised to 80°C for 2h of heat preservation, the solid is precipitated by gradient cooling at a cooling rate of 10°C / h to 2°C, and the solid is obtained by filtration, which is 3.5g of yellowish solid, and the purity is ≥98%.

[0092] Example 3

[0093] The present example provides a preparation method of a photoinitiator 389, which comprises:

[0094] 3.1g of 389 raw material (a compound as shown in formula (I)) is added into 14g of water, 1.4g of potassium carbonate, 1.8g of piperidine, and 0.04g of catalyst (the same as in Example 1) is sequentially added into a reaction bottle, the reactor is sealed by nitrogen replacement, and the temperature is raised to 65°C for 12-13 hours of reaction, the raw material is detected by HPLC to be ≤0.5%, 80ml of dichloromethane and 40ml of water are added, the catalyst is removed by stirring and filtration, the organic phase is washed with water twice, dried with anhydrous sodium sulfate, concentrated to obtain 3.64g of white solid, and the purity is ≥90%. The solid is added into 15ml of ethanol, the temperature is raised to 75°C for 2h of heat preservation, the solid is precipitated by gradient cooling at a cooling rate of 10°C / h to 5°C, and the solid is obtained by filtration, which is 3.3g of white solid, and the purity is ≥98%.

[0095] The above is a preferred embodiment of the application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements are also considered to be within the protection scope of the application.

Claims

1. A method for preparing a class of aryl α-ketone photoinitiators, characterized in that, The reaction includes the steps of using a compound of formula (I) or formula (II), morpholine or piperidine as reactants, potassium carbonate as an acid-binding agent, and the reaction being carried out in the presence of a catalyst; （I） (II) The aryl α-ketone photoinitiator is photoinitiator 369, photoinitiator 379, or photoinitiator 389. The catalyst is a porous SiO2-supported palladium-copper composite catalyst with an average particle size of 180-250 nm and a copper-to-palladium weight ratio of 92:2-98:

8. The method for preparing the catalyst includes: (1) Provide or prepare carbon nanospheres; (2) Disperse carbon nanospheres in water to obtain dispersion A with a concentration of 1~5 g / L; disperse copper chloride in dispersant A to obtain dispersion B with a concentration of 3~10 g / L; mix dispersion A and dispersion B evenly and then separate solid and liquid to obtain intermediate A; wherein, dispersant A is sulfuric acid solution, hydrochloric acid solution or nitric acid solution. (3) Disperse intermediate A in water to obtain dispersion C with a concentration of 5~12 g / L. Add divalent palladium salt solution and sodium acetate solution in sequence, mix for 3~8 h, and then separate the solid and liquid to obtain intermediate B; wherein, the divalent palladium salt solution contains Pd 2+ The concentration of sodium acetate in the sodium acetate solution is 0.03~0.2 mol / L, and the concentration of sodium acetate in the sodium acetate solution is 0.1~0.5 mol / L; the volume ratio of the divalent palladium salt solution to the dispersion C is 0.1:10~0.3:10, and the volume ratio of the sodium acetate solution to the dispersion C is 0.2:1~0.5:1; (4) Mix the intermediate B, dispersant B, CTAB and NH3·H2O evenly to obtain dispersion D; wherein, the dispersant B is one or more of water, ethanol or methanol, and the concentration of the intermediate B in the dispersion D is 2~10 g / L, the concentration of CTAB is 1~3 g / L, and the concentration of NH3·H2O is 0.5~2 mol / L; (5) Add tetraethyl silicate to the dispersion D, stir at 20℃~40℃ for 2~12h and then separate the solid and liquid to obtain intermediate C; wherein the volume ratio of dispersion D to tetraethyl silicate is 400:1~550:

1. (6) The intermediate C is calcined in an inert atmosphere at 350-450°C for 1-4 hours, and then calcined in an oxygen-containing atmosphere at 350-450°C for 2-8 hours to obtain the catalyst product.

2. The method for preparing the aryl α-ketone photoinitiator as described in claim 1, characterized in that, In the step of reacting with the compound represented by formula (I) or formula (II), morpholine or piperidine as reactants, potassium carbonate as an acid-binding agent, and under the action of a catalyst, water is used as a solvent.

3. The method for preparing the aryl α-ketone photoinitiator as described in claim 1, characterized in that, In the step of reacting with the compound represented by formula (I) or formula (II), morpholine or piperidine as reactants, potassium carbonate as an acid-binding agent, and under the action of a catalyst, the reaction temperature is 60~70℃ and the reaction time is 12~15h.

4. The method for preparing the aryl α-ketone photoinitiator as described in claim 1, characterized in that, The aryl α-ketone photoinitiator is photoinitiator 369, and its preparation method includes the steps of reacting the compound shown in formula (I) and morpholine as reactants, using potassium carbonate as an acid-binding agent, water as a solvent, and carrying out the reaction under the action of a catalyst; or The aryl α-ketone photoinitiator is photoinitiator 379, and its preparation method includes the steps of reacting the compound shown in formula (II) and morpholine as reactants, using potassium carbonate as an acid-binding agent, water as a solvent, and carrying out the reaction under the action of a catalyst; or The aryl α-ketone photoinitiator is photoinitiator 389, and its preparation method includes the steps of using the compound shown in formula (I) and piperidine as reactants, potassium carbonate as an acid-binding agent, water as a solvent, and carrying out the reaction under the action of a catalyst.

5. The method for preparing the aryl α-ketone photoinitiator according to any one of claims 1 to 4, characterized in that, It also includes the step of purifying the reaction products; The step of purifying the reaction product includes dispersing the reaction product in ethanol, then heating it to 70-80°C, holding it at that temperature for 1-4 hours, and then gradually cooling it to 0-5°C to allow the reaction product to recrystallize.

6. The method for preparing the aryl α-ketone photoinitiator as described in claim 1, characterized in that, In step (6), the intermediate is calcined in a nitrogen atmosphere at 390°C to 420°C for 1.5 to 2.2 hours, and then calcined in an air atmosphere at 350 to 380°C for 5 to 7 hours to obtain the catalyst product supported on hollow silicon nanocapsules.

7. The method for preparing the aryl α-ketone photoinitiator as described in claim 1, characterized in that, In step (1), glucose is dispersed in water to obtain a dispersion E with a concentration of 120~150g / L. Then, a hydrothermal reaction is carried out at 200~300℃ for 2~5h. After solid-liquid separation, carbon nanospheres are obtained.

8. The method for preparing the aryl α-ketone photoinitiator as described in claim 1, characterized in that, In step (2), the dispersant A is a hydrochloric acid solution with a concentration of 0.01~0.1 mol / L; In step (3), the divalent palladium salt solution is a PdCl2 solution or a palladium acetate solution; the Pd in ​​the divalent palladium salt solution... 2+ The concentration is 0.04~0.1mol / L.

9. The method for preparing the aryl α-ketone photoinitiator as described in claim 1, characterized in that, In step (4), the dispersant B is a mixture of water and ethanol, with a volume ratio of water to ethanol of 1.5:1 to 3:1.

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