Preparation method of 1,3-diphenylpropanetrione, 1,3-diphenylpropanetrione, photoinitiator system and photopolymerization system

Abstract

The present invention relates to a kind of preparation method of 1,3 diphenyl acetone, dibenzoylmethane and N bromosuccinimide, react under the condition of adding DMSO, and N2 is passed through during the reaction; After the reaction is completed, extraction, the lower layer of extraction solution is rotary evaporated to obtain a yellow solid, and 1,3 diphenyl acetone is prepared. Extractant is extractant A extractant B system; The extractant A is any one of sodium chloride solution, sodium nitrate solution, potassium chloride solution, and potassium nitrate solution; The extractant B is any one of dichloromethane, chloroform, and acetonitrile, and the concentration of the extractant A is at least 15wt%. By a specific extractant system, DMSO can be efficiently removed, greatly improving the purity of 1,3 diphenyl acetone. Meanwhile, the present invention also discloses that the aforementioned method obtains 1,3 diphenyl acetone, a photoinitiator system comprising the 1,3 diphenyl acetone, and a photopolymerization system.

Description

[0001] Field

[0002] The present invention relates to the technical field of photopolymerization, and in particular to a method for preparing 1,3-diphenylpropanetrione, the 1,3-diphenylpropanetrione obtained by the preparation method, a 1,3-diphenylpropanetrione photoinitiator system, and a photopolymerization system. Background Art

[0003] 1,3-Diphenylpropanetrione (DPPT) is widely used in the reversible cross-linking and self-healing materials of polymers and is an important raw material. In the prior art, the preparation method of 1,3-diphenylpropanetrione adds DMSO as a solvent and oxidant, and removes DMSO after the reaction is completed. In the prior art, DMSO is generally removed by vacuum distillation and water washing extraction. However, due to the characteristics of the reaction product, there are technical difficulties in removing DMSO using vacuum distillation and water washing extraction. This is because although DPPT is insoluble in water, it reacts with water, and DPPT forms a dynamic equilibrium reaction with the hydrated structure of DPPT in the solution (as shown below).

[0004]

[0005] If DMSO is not removed quickly, it will form hydrogen bonds with the hydrated DPPT-H2O structure, making it difficult to remove the hydrated structure even under vacuum drying, and thus failing to obtain high-purity DPPT. Vacuum distillation inevitably requires the use of a water pump, shifting the dynamic equilibrium reaction to the right. As the content of the hydrated DPPT-H2O increases, the DPPT dissolved in DMSO will react with water, ultimately making it impossible to remove this portion of DMSO and DPPT-H2O, ultimately affecting the purity of DPPT.

[0006] In view of this, developing a method for preparing high-purity DPPT has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0007] To address the problems existing in the prior art, the present invention provides a method for preparing 1,3-diphenylpropanetrione, 1,3-diphenylpropanetrione, a photoinitiator system, and a photopolymerization system. The preparation method of the present invention utilizes a specific extractant system to efficiently remove DMSO, significantly improving the purity of 1,3-diphenylpropanetrione.

[0008] One of the objects of the present invention is to provide a method for preparing 1,3-diphenylpropanetrione, which comprises:

[0009] Dibenzoylmethane and N-bromosuccinimide react under the condition of adding DMSO, and nitrogen is introduced during the reaction process; after the reaction is completed, extraction is performed, and the lower layer of the extract solution is rotary evaporated to obtain a yellow solid to prepare 1,3-diphenylpropanetrione;

[0010] The extractant is an extractant A-extractant B system; the extractant A is any one of sodium chloride solution, sodium nitrate solution, potassium chloride solution, and potassium nitrate solution; the extractant B is any one of dichloromethane, chloroform, and acetonitrile, and the concentration of the extractant A is at least 15wt% to ensure the removal effect of DMSO.

[0011] The reaction equation of dibenzoylmethane and N-bromosuccinimide is as follows:

[0012]

[0013] Preferably, the concentration of the extractant A is 16-26 wt%; and / or

[0014] The volume ratio of the extractant A to the extractant B is 1:1 to 1.5.

[0015] The present invention can specifically adopt the following technical solutions:

[0016] The preparation method comprises the following steps:

[0017] Dibenzoylmethane and N-bromosuccinimide (NBS) are dissolved in anhydrous DMSO and reacted under a continuous nitrogen flow. For example, extractant A is sodium chloride solution and extractant B is dichloromethane. After the reaction is complete, sodium chloride solution and dichloromethane are added to the reaction solution for extraction to remove the DMSO solvent. After standing, the sodium chloride solution is on the upper layer and the dichloromethane is on the lower layer. The dichloromethane layer is yellow. In practice, the dichloromethane layer can be extracted several times with sodium chloride solution until the sodium chloride solution layer is colorless to further improve the purity of DPPT. The sodium chloride solution layer is discarded, and the dichloromethane layer is retained. The dichloromethane layer is rotary evaporated until a yellow solid is obtained. The yellow solid is dried to obtain 1,3-diphenylpropanetrione. Preferably, the concentration of extractant A is 16-26 wt% to further improve the removal of DMSO. More preferably, the volume ratio of the extractant A to the extractant B is 1:1 to 1.5, so as to further improve the removal effect of DMSO.

[0018] Preferably, the mass ratio of dibenzoylmethane to N-bromosuccinimide is 1:1-1.1, the reaction time is 30-40 hours, the reaction temperature is 48-50°C, and the N2 introduction rate is 3-6 m / s. During the actual reaction process, technicians can adjust the various reaction parameters and the mass ratio of the two reactants as appropriate.

[0019] Preferably, before rotary evaporation, sodium bicarbonate solution is added to the extraction solution, and the sodium bicarbonate solution layer is discarded. Specifically, sodium bicarbonate solution is added to the dichloromethane layer to remove impurities during the reaction, primarily dibenzoylmethane, NBS, and brominated products generated by the intermediate reaction, thereby further improving the purity of DPPT. After standing, the sodium bicarbonate solution is in the upper layer and the dichloromethane is in the lower layer. The sodium bicarbonate solution layer is discarded, and the dichloromethane layer is retained. The sodium bicarbonate solution has a concentration of at least 6 wt%. More preferably, the sodium bicarbonate solution has a concentration of 7 to 10 wt% to further enhance impurity removal.

[0020] Preferably, after rotary evaporation, the yellow solid obtained by rotary evaporation is recrystallized from petroleum ether to obtain 1,3-diphenylpropanetrione, and the generated benzil and other impurities are further removed. Specifically, DPPT is not easily soluble in petroleum ether, so the petroleum ether is heated. The heated petroleum ether is added dropwise to the yellow solid obtained by rotary evaporation until the yellow solid is completely dissolved. The petroleum ether-DPPT solution is gradually cooled to room temperature, and yellow crystals slowly precipitate during the cooling process, thereby obtaining 1,3-diphenylpropanetrione.

[0021] The second object of the present invention is to provide 1,3-diphenylpropanetrione prepared according to one of the objects of the present invention.

[0022] A third object of the present invention is to provide a photoinitiator system comprising 1,3-diphenylpropanetrione, the second object of the present invention, further comprising an initiator co-initiator. Preferably, the co-initiator is selected from at least one of triethanolamine, ethyl 4-dimethylaminobenzoate, and ethanol. More preferably, the weight ratio of the 1,3-diphenylpropanetrione to the co-initiator is 1:1 to 4. A skilled person can select an appropriate co-initiator and an appropriate amount of the co-initiator as appropriate.

[0023] A fourth object of the present invention is to provide a photopolymerization system comprising the second object of the present invention, 1,3-diphenylpropanetrione, or the third object of the present invention, a photoinitiator system. The photopolymerization system further comprises a photopolymerizable monomer. Preferably, the photopolymerizable monomer is any one of hydroxyethyl acrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, and trimethylolpropane triacrylate. More preferably, the mass fraction of the 1,3-diphenylpropanetrione in the photopolymerization system is 0.25 to 2 wt%. A skilled person can select the appropriate photopolymerizable monomer and initiator addition amount as appropriate.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The preparation method of the present invention uses a specific extractant system to efficiently remove DMSO, greatly improving the purity of 1,3-diphenylpropanetrione. At the same time, the method for preparing 1,3-diphenylpropanetrione of the present invention is simple, the raw materials are readily available, and the cost is low.

[0026] 2. The maximum absorption wavelength of the 1,3-diphenylpropanetrione prepared by the present invention as a long-wavelength photoinitiator can reach above 365 nm, which can match the emission wavelength of the LED light source.

[0027] 3. The 1,3-diphenylpropanetrione prepared in the present invention can be used as a long-wavelength photoinitiator to initiate monomer polymerization under the irradiation of 365nm and 405nm LED light sources, and has excellent photopolymerization performance; when 1,3-diphenylpropanetrione acts together with a co-initiator, the photopolymerization performance is further enhanced; when 1,3-diphenylpropanetrione acts together with a tertiary amine co-initiator, photopolymerization reaction can even be carried out under a 460nm blue light LED light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The ultraviolet absorption spectrum (c=10 -3 M). DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to specific drawings and embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0030] All the raw materials used in the examples are commercially available. All the instruments used in the examples are commercially available.

[0031] In the examples, HEA is hydroxyethyl acrylate, PEGDA is polyethylene glycol diacrylate, TPGDA is tripropylene glycol diacrylate, HDDA is 1,6-hexanediol diacrylate, TMPTA is trimethylolpropane triacrylate; TEOA is triethanolamine; EDAB is ethyl 4-dimethylaminobenzoate; and EtOH is ethanol.

[0032] In the examples, the density of DMSO is 1.1 g / ml, the density of dichloromethane is 1.325 g / ml, and the concentration of chloroform is 1.48 g / ml.

[0033] In the embodiment, the purity is based on 1Purity is calculated based on the impurity peaks in H NMR, with benzil as the impurity. The specific calculation formula is: Purity = (A1 / n1) / (A1 / n1+A2 / n2). Where A1 is the peak area of ​​DPPT, n1 is the number of hydrogen atoms in DPPT, A2 is the peak area of ​​the impurity, and n2 is the number of hydrogen atoms in the impurity.

[0034] Example 1

[0035] Take 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) and dissolve them in DMSO (165 parts by weight) that has been dehydrated with anhydrous sodium sulfate in advance, and react at 50°C for 38 hours under N2. Prepare a sodium chloride solution with a concentration of 23.08wt% and a sodium bicarbonate solution with a concentration of 9.09wt%. The amounts of the sodium chloride solution, dichloromethane, and sodium bicarbonate solution are 260 parts by weight, 265 parts by weight, and 330 parts by weight, respectively. First, extract with sodium chloride solution and dichloromethane, discard the sodium chloride solution layer, and retain the dichloromethane layer. Add sodium bicarbonate solution to the dichloromethane layer, discard the sodium bicarbonate solution layer, and retain the dichloromethane layer. Rotary evaporate the dichloromethane layer to obtain a yellow solid. The product was recrystallized from petroleum ether to obtain a pure product, which was then dried in a vacuum drying oven at 60°C for 10 hours to obtain 1,3-diphenylpropanetrione with a purity of 98%. 1 The H NMR spectrum information is as follows:

[0036] 1 H NMR (400MHz, CDCl3) δ8.11–8.06(m,4H),7.72(t,J=7.5Hz,2H),7.57(t,J=7.8Hz,4H).13C NMR (101MHz, CDCl3) δ192.26(s), 188.07(s), 135.21(s), 131.96(s), 130.04(s), 128.91(s).

[0037] The 1,3-diphenylpropanetrione prepared in Example 1 was subjected to ultraviolet absorption spectrum measurement. The specific steps are: the 1,3-diphenylpropanetrione prepared in Example 1 was prepared with deoxyacetonitrile to a concentration of about 10 -3 The solution was added to a quartz cuvette and its UV-visible absorption spectrum was measured at room temperature using a UV-visible spectrometer in the range of 200 to 600 nm. Figure 1 As shown. Figure 1 It can be seen that the 1,3-diphenylpropanetrione prepared in Example 1 has an absorption peak at 400-500 nm, that is, it can match the long-wavelength irradiation range of the LED light source.

[0038] Example 2

[0039] Take 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) and dissolve them in DMSO (165 parts by weight) that has been dehydrated with anhydrous sodium sulfate in advance, and react at 50°C for 38 hours through N2. Prepare a sodium chloride solution with a concentration of 16.67wt% and a sodium bicarbonate solution with a concentration of 9.09wt%. The amounts of the sodium chloride solution, chloroform, and sodium bicarbonate solution are 240 parts by weight, 296 parts by weight, and 330 parts by weight, respectively. First, extract with potassium chloride solution and chloroform, discard the potassium chloride solution layer, and retain the chloroform layer. Add sodium bicarbonate solution to the organic layer, discard the sodium bicarbonate solution layer, and retain the organic layer. Perform rotary evaporation to obtain a yellow solid. Recrystallize with petroleum ether to obtain a pure product, and then dry it in a vacuum drying oven at 60°C for 10 hours to obtain 1,3-diphenylpropanetrione with a purity of 97%. The product 1 The H NMR spectrum information is as follows:

[0040] 1 H NMR (400MHz, CDCl3) δ8.11–8.06(m,4H),7.72(t,J=7.5Hz,2H),7.57(t,J=7.8Hz,4H).13C NMR (101MHz, CDCl3) δ192.26(s), 188.07(s), 135.21(s), 131.96(s), 130.04(s), 128.91(s).

[0041] Example 3

[0042] Take 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) and dissolve them in DMSO (165 parts by weight) that has been dehydrated with anhydrous sodium sulfate in advance, and react at 50°C for 38 hours under N2. Prepare a sodium chloride solution with a concentration of 16.67wt% and a sodium bicarbonate solution with a concentration of 9.09wt%. The amounts of the sodium chloride solution, dichloromethane, and sodium bicarbonate solution are 240 parts by weight, 265 parts by weight, and 440 parts by weight, respectively. First, extract with sodium chloride solution and dichloromethane, discard the sodium chloride solution layer, and retain the dichloromethane layer. Add sodium bicarbonate solution to the dichloromethane layer, discard the sodium bicarbonate solution layer, and retain the dichloromethane layer. Rotary evaporate the dichloromethane layer to obtain a yellow solid. The product was recrystallized from petroleum ether to obtain a pure product, which was then dried in a vacuum drying oven at 60°C for 10 hours to obtain 1,3-diphenylpropanetrione with a purity of 95%. 1 The H NMR spectrum information is as follows:

[0043] 1H NMR (400MHz, CDCl3) δ8.11–8.06(m,4H),7.72(t,J=7.5Hz,2H),7.57(t,J=7.8Hz,4H).13C NMR (101MHz, CDCl3) δ192.26(s), 188.07(s), 135.21(s), 131.96(s), 130.04(s), 128.91(s).

[0044] Example 4

[0045] Take 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) and dissolve them in DMSO (165 parts by weight) that has been dehydrated with anhydrous sodium sulfate in advance. The mixture is reacted at 50°C for 38 hours under N2. A sodium chloride solution with a concentration of 20wt% and a sodium bicarbonate solution with a concentration of 9.09wt% are prepared. The amounts of the sodium chloride solution, dichloromethane, and sodium bicarbonate solution are 250 parts by weight, 397.5 parts by weight, and 330 parts by weight, respectively. First, extract with sodium chloride solution and dichloromethane, with a concentrated salt water / dichloromethane weight ratio of 1:0.5. Discard the sodium chloride solution layer and retain the dichloromethane layer. Add sodium bicarbonate solution to the dichloromethane layer, discard the sodium bicarbonate solution layer, and retain the dichloromethane layer. Rotary evaporate the dichloromethane layer to obtain a yellow solid. The product was recrystallized from petroleum ether to obtain a pure product, which was then dried in a vacuum drying oven at 60°C for 10 hours to obtain 1,3-diphenylpropanetrione with a purity of 97%. 1 The H NMR spectrum information is as follows:

[0046] 1 H NMR (400MHz, CDCl3) δ8.11–8.06(m,4H),7.72(t,J=7.5Hz,2H),7.57(t,J=7.8Hz,4H).13C NMR (101MHz, CDCl3) δ192.26(s), 188.07(s), 135.21(s), 131.96(s), 130.04(s), 128.91(s).

[0047] Example 5

[0048] Take 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) and dissolve them in DMSO (165 parts by weight) that has been dehydrated with anhydrous sodium sulfate in advance, and react at 50°C for 38 hours with N2. Prepare a sodium chloride solution with a concentration of 23.08wt% and a sodium bicarbonate solution with a concentration of 9.09wt%. The amounts of the sodium chloride solution, chloroform, and sodium bicarbonate solution are 260 parts by weight, 265 parts by weight, and 330 parts by weight, respectively. First, extract with sodium chloride solution and dichloromethane, discard the sodium chloride solution layer, and retain the dichloromethane layer. Add sodium bicarbonate solution to the dichloromethane layer, discard the sodium bicarbonate solution layer, and retain the dichloromethane layer. Rotary evaporate the dichloromethane layer to obtain a yellow solid, and then dry it in a vacuum drying oven at 60°C for 10 hours to obtain 1,3-diphenylpropanetrione with a purity of 92%. The product 1 The H NMR spectrum information is as follows:

[0049] 1 H NMR (400MHz, CDCl3) δ8.11–8.06(m,4H),7.72(t,J=7.5Hz,2H),7.57(t,J=7.8Hz,4H).13C NMR (101MHz, CDCl3) δ192.26(s), 188.07(s), 135.21(s), 131.96(s), 130.04(s), 128.91(s).

[0050] Example 6

[0051] Take 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) and dissolve them in DMSO (165 parts by weight) that has been dehydrated with anhydrous sodium sulfate in advance, and react at 50°C for 38 hours under N2. Prepare a sodium chloride solution with a concentration of 25.93wt% and a sodium bicarbonate solution with a concentration of 9.09wt%. The amounts of the sodium chloride solution, dichloromethane, and sodium bicarbonate solution are 270 parts by weight, 265 parts by weight, and 220 parts by weight, respectively. First, extract with sodium chloride solution and dichloromethane, discard the sodium chloride solution layer, and retain the dichloromethane layer. Add sodium bicarbonate solution to the dichloromethane layer, discard the sodium bicarbonate solution layer, and retain the dichloromethane layer. Rotary evaporate the dichloromethane layer to obtain a yellow solid. The product was recrystallized from petroleum ether to obtain a pure product, which was then dried in a vacuum drying oven at 60°C for 10 hours to obtain 1,3-diphenylpropanetrione with a purity of 97%. 1 The H NMR spectrum information is as follows:

[0052] 1H NMR (400MHz, CDCl3) δ8.11–8.06(m,4H),7.72(t,J=7.5Hz,2H),7.57(t,J=7.8Hz,4H).13C NMR (101MHz, CDCl3) δ192.26(s), 188.07(s), 135.21(s), 131.96(s), 130.04(s), 128.91(s).

[0053] Example 7

[0054] Take 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) and dissolve them in DMSO (165 parts by weight) that has been dehydrated with anhydrous sodium sulfate in advance, and react at 50°C for 38 hours under N2. Prepare a sodium chloride solution with a concentration of 23.08wt% and a sodium bicarbonate solution with a concentration of 6.54wt%. The amounts of the sodium chloride solution, dichloromethane, and sodium bicarbonate solution are 260 parts by weight, 265 parts by weight, and 428 parts by weight, respectively. First, extract with sodium chloride solution and dichloromethane, discard the sodium chloride solution layer, and retain the dichloromethane layer. Add sodium bicarbonate solution to the dichloromethane layer, discard the sodium bicarbonate solution layer, and retain the dichloromethane layer. Rotary evaporate the dichloromethane layer to obtain a yellow solid. The product was recrystallized from petroleum ether to obtain a pure product, which was then dried in a vacuum drying oven at 65°C for 12 hours to obtain 1,3-diphenylpropanetrione with a purity of 97%. 1 The H NMR spectrum information is as follows:

[0055] 1 H NMR (400MHz, CDCl3) δ8.11–8.06(m,4H),7.72(t,J=7.5Hz,2H),7.57(t,J=7.8Hz,4H).13C NMR (101MHz, CDCl3) δ192.26(s), 188.07(s), 135.21(s), 131.96(s), 130.04(s), 128.91(s).

[0056] Comparative Example 1

[0057] Take 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) and dissolve them in DMSO (165 parts by weight) that has been dehydrated with anhydrous sodium sulfate in advance, and react at 50°C for 38 hours through N2. Prepare a sodium bicarbonate solution with a concentration of 9.09wt%, add 265 parts by weight of dichloromethane and 330 parts by weight of sodium bicarbonate aqueous solution, discard the upper mixed solution, and retain the lower dichloromethane layer. Rotary evaporate the dichloromethane layer to obtain a yellow solid. Recrystallize it with petroleum ether to obtain a pure product, and then dry it in a vacuum drying oven at 60°C for 10 hours to obtain 1,3-diphenylpropanetrione with a purity of 63%. The product 1 The H NMR spectrum information is as follows:

[0058] 1 H NMR (400MHz, CDCl3) δ8.11–8.06(m,4H),7.72(t,J=7.5Hz,2H),7.57(t,J=7.8Hz,4H).13C NMR (101MHz, CDCl3) δ192.26(s), 188.07(s), 135.21(s), 131.96(s), 130.04(s), 128.91(s).

[0059] Comparative Example 2

[0060] 6.72 parts by weight of dibenzoylmethane and 5.34 parts by weight of N-bromosuccinimide (NBS) were dissolved in 165 parts by weight of DMSO, previously dehydrated with anhydrous sodium sulfate, and reacted at 50°C for 38 hours under nitrogen. Extraction was then performed by adding 200 parts by weight of water and 265 parts by weight of dichloromethane. The three substances did not separate into separate layers, but formed an emulsion.

[0061] Application Example 1

[0062] 99.75 parts by weight of HEA monomer and 0.25 parts by weight of 1,3-diphenylpropanetrione prepared in Example 1 were selected to prepare a photosensitive solution.

[0063] Application Example 2

[0064] 99 parts by weight of HEA monomer and 1 part by weight of 1,3-diphenylpropanetrione prepared in Example 1 were selected to prepare a photosensitive solution.

[0065] Application Example 3

[0066] 98 parts by weight of HEA monomer and 2 parts by weight of 1,3-diphenylpropanetrione prepared in Example 1 were selected to prepare a photosensitive solution.

[0067] The photosensitive liquids in Application Examples 1 to 3 were coated in a double-layer KBr salt sheet with a thickness of about 30 μm. They were illuminated by a 365 nm LED and a 405 nm light source, respectively, with a light intensity of 50 mW / cm 2 The real-time infrared spectrometer (Nicolet 5700, 4000-600cm -1 ) Record the changes in the infrared spectrum of the sample during the illumination process, with a sampling interval of about 2s. The double bond conversion (DBC) is based on the 820-800cm -1 Calculation of the change in peak area at:

[0068] DBC%=[1-(A810) t / (A810)0]×100%

[0069] Among them, (A810)0 and (A810)t are 810cm before and after illumination, respectively. -1 The area of ​​the absorption peak at the absorption peak was measured repeatedly for each sample until the error was less than 3% for three consecutive times. The test results are shown in Table 1. Analysis of the results in Table 1 shows that under the irradiation of 365nm LED and 405nm LED light sources, 1,3-diphenylpropanetrione can initiate the polymerization of HEA, and has excellent photopolymerization performance. It should be noted that under the same test conditions, if the monomer is replaced with PEGDA or TPGDA, similar double bond conversion rates can be achieved, and the photopolymerization performance is excellent. Under the same test conditions, if the monomer is replaced with HDDA, the double bond conversion rate is slightly lower, and the double bond conversion rate is about 72% under the irradiation of 365nm LED light source, but it is also suitable for industrial applications. It can be seen that 1,3-diphenylpropanetrione can match the emission wavelength of the LED light source, initiate the polymerization of photopolymerizable monomers, and has excellent photopolymerization performance.

[0070] Table 1 Double bond conversion rate of application examples 1-3

[0071]

[0072] Application Example 4

[0073] 96 parts by weight of HDDA monomer, 1 part by weight of 1,3-diphenylpropanetrione prepared in Example 1, and 3 parts by weight of TEOA were selected to prepare a photosensitive solution.

[0074] Application Example 5

[0075] 96 parts by weight of HDDA monomer, 1 part by weight of 1,3-diphenylpropanetrione prepared in Example 1, and 3 parts by weight of EDAB were selected to prepare a photosensitive solution.

[0076] Application Example 6

[0077] 96 parts by weight of HDDA monomer, 1 part by weight of 1,3-diphenylpropanetrione prepared in Example 1, and 3 parts by weight of EtOH were selected to prepare a photosensitive solution.

[0078] Application Example 7

[0079] 98 parts by weight of HDDA monomer, 1 part by weight of 1,3-diphenylpropanetrione prepared in Example 1, and 1 part by weight of TEOA were selected to prepare a photosensitive solution.

[0080] Application Example 8

[0081] 95 parts by weight of HDDA monomer, 1 part by weight of 1,3-diphenylpropanetrione prepared in Example 1, and 4 parts by weight of TEOA were selected to prepare a photosensitive solution.

[0082] Table 2 Double bond conversion rate of application examples 4-8

[0083]

[0084] The photosensitive liquids in Application Examples 4 to 8 were coated in a double-layer KBr salt sheet with a thickness of about 30 μm. 365 nm LED, 405 nm LED, and 460 nm LED light sources were used for irradiation, respectively, with a light intensity of 50 mW / cm 2 The real-time infrared spectrometer (Nicolet 5700, 4000-600cm -1 ) Changes in the sample's infrared spectrum during illumination were recorded. The double bond conversion rate was calculated using the same method as previously described. The test results are shown in Table 2. Analysis of the results in Table 2 shows that the photoinitiator system consisting of 1,3-diphenylpropanetrione and a co-initiator can initiate polymerization of the photopolymerizable monomers under both 365nm and 405nm LED illumination. The double bond conversion rates of Application Examples 4-8 after 5 minutes of 365nm LED illumination were all higher than the 72% achieved when 1,3-diphenylpropanetrione was used alone as a photoinitiator, demonstrating that the photopolymerization performance is even better when 1,3-diphenylpropanetrione is used in conjunction with a co-initiator. Even under 460nm LED illumination, the photoinitiator system consisting of 1,3-diphenylpropanetrione and a tertiary amine co-initiator can still initiate polymerization of the photopolymerizable monomers. This demonstrates that the photopolymerization performance of 1,3-diphenylpropanetrione is further enhanced when used in conjunction with a co-initiator. In particular, when used in conjunction with a tertiary amine co-initiator, photopolymerization can even proceed under 460nm blue LED illumination.

[0085] It should be noted that when triethanolamine or ethyl 4-dimethylaminobenzoate is the co-initiator, photopolymerization can be initiated under a 460nm blue LED light source. However, when EtOH is used as the co-initiator, photopolymerization does not actually occur under 460nm blue LED light, so the double bond conversion rate is not entered here.

Claims

1. A method for preparing 1,3-diphenylpropanetrione, characterized in that: The method comprises: Dibenzoylmethane and N-bromosuccinimide react under the condition of adding DMSO, and nitrogen is introduced during the reaction; after the reaction is completed, extraction is performed, sodium bicarbonate solution is added to the lower layer of the extraction solution, and the sodium bicarbonate solution layer is discarded; the lower layer of the extraction solution is rotary evaporated to obtain a yellow solid to prepare 1,3-diphenylpropanetrione; The extractant is an extractant A-extractant B system; the extractant A is any one of sodium chloride solution, sodium nitrate solution, potassium chloride solution, and potassium nitrate solution; the extractant B is any one of dichloromethane, chloroform, and acetonitrile, and the concentration of the extractant A is at least 15wt%; the concentration of the sodium bicarbonate solution is at least 6wt%.

2. The method according to claim 1, wherein: The concentration of the extractant A is 16-26 wt%; and / or The volume ratio of the extractant A to the extractant B is 1:1 to 1.

5.

3. The method according to any one of claims 1 or 2, characterized in that: The method further comprises: The sodium bicarbonate solution has a concentration of 7 to 10 wt%; and / or After rotary evaporation, the yellow solid obtained by rotary evaporation was recrystallized from petroleum ether to obtain 1,3-diphenylpropanetrione.

4. The method according to claim 1, wherein: The mass ratio of the dibenzoylmethane to the N-bromosuccinimide is 1:1 to 1.1; The reaction time is 30h to 40h; and / or The reaction temperature is 48-50°C; and / or The N2 introduction rate is 3-6 m / s.

5. A photoinitiator system, characterized in that: The photoinitiator system comprises 1,3-diphenylpropanetrione prepared by the method according to any one of claims 1 to 4 and a co-initiator.

6. The photoinitiator system according to claim 5, characterized in that: The co-initiator is selected from at least one of triethanolamine, ethyl 4-dimethylaminobenzoate and ethanol.

7. The photoinitiator system according to claim 6, characterized in that: The weight ratio of the 1,3-diphenylpropanetrione to the co-initiator is 1:1-4.

8. The photoinitiator system according to claim 7, characterized in that: The weight ratio of the 1,3-diphenylpropanetrione to the co-initiator is 1:3-4.

9. A photopolymerization system, characterized in that: The method comprises 1,3-diphenylpropanetrione prepared by the method described in any one of 1 to 4 or the photoinitiator system and photopolymerization monomer described in any one of claims 5 to 8.

10. The photopolymerization system according to claim 9, wherein: The photopolymerizable monomer is any one of hydroxyethyl acrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, and trimethylolpropane triacrylate.

11. The photopolymerization system according to claim 9, wherein: The mass fraction of the 1,3-diphenylpropanetrione is 0.25-2 wt %.

12. The photopolymerization system according to claim 11, wherein: The mass fraction of the 1,3-diphenylpropanetrione is 1 to 1.5 wt %.

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