Acylphosphine oxide photoinitiator with chalcone structure and preparation method thereof

Abstract

The present invention relates to an acylphosphine oxide photoinitiator having a chalcone structure and a preparation method thereof. Chalcone aldehyde is reacted with diphenylphosphine oxide to obtain an intermediate, which is then mixed with an oxide and reacted in the presence of a catalyst to obtain an acylphosphine oxide compound having a chalcone structure. The maximum absorption wavelength of the synthesized acylphosphine oxide photoinitiator having a chalcone structure is red-shifted to varying degrees compared to TPO, with a maximum red-shift of 21 nm. The molar absorption coefficient is much greater than that of TPO, reaching a maximum of 16 times that of TPO. The compound can be used as a photoinitiator.

Description

Technical Field

[0001] The invention relates to an organic polymer compound, a photoinitiator used in a polymerization process, and belongs to the field of photocurable materials, in particular to an acylphosphine oxide photoinitiator with a chalcone structure and a preparation method thereof. Background Art

[0002] Photocuring technology is energy-saving, clean, and environmentally friendly. Photocurable materials offer the advantages of high performance, low cost, low energy consumption, minimal environmental pollution, and environmental friendliness. They are widely used in coatings, varnishes, 3D printing, UV ink printing, dental restorations, food packaging, and other fields. Traditional photoinitiators, due to their use of mercury lamps, pose significant environmental risks. Currently, LED photocuring has become mainstream, with commercialized and widely used initiators such as 2, 4, 6-trimethylbenzoyldiphenylphosphine oxide (TPO). However, TPO is gradually being phased out due to its low absorption in the long-wavelength range, poor storage stability, and risks of migration and toxicity. Therefore, the development of initiators with strong LED light absorption is of great significance. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides an acylphosphine oxide photoinitiator with a chalcone structure and a preparation method thereof.

[0004] The technical solution adopted by the present invention is: an acylphosphine oxide compound having a chalcone structure, the structure of which is shown in Formula I;

[0005] Formula I;

[0006] Wherein R1, R2, R3, R4, and R5 are independently represented by H, C1-C 10 Alkyl, C1-C 10 Alkoxy, C1-C 10 Alkylthio, C1-C 10 One or more of dialkylamino and halogen;

[0007] Preferably, halogen is F, Cl or Br;

[0008] Preferably, R1, R2, R3, R4, and R5 are independently represented by one of H, methyl, ethyl, propyl, methoxy, ethoxy, methylthio, ethylthio, dimethylamino, and diethylamino, and R1, R2, R3, R4, and R5 are the same, partially the same, or different.

[0009] Preferably, the structure is as shown in any one of Formulas 1-8;

[0010] Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 Formula 7 Formula 8.

[0011] The preparation method of an acylphosphine oxide compound having a chalcone structure comprises the following steps:

[0012] Step 1: placing the compound of formula II and diphenylphosphine oxide in a first solvent and reacting at 10-40° C. to obtain the compound of formula IV;

[0013] Step 2: Add the compound of formula IV to a second solvent, add an oxidant and a catalyst, and stir to react to obtain a compound of formula I;

[0014] Formula II;

[0015] Formula IV.

[0016] Preferably, in step 1, the first solvent is one of dichloromethane, dichloroethane, ethyl acetate, cyclohexane, tetrahydrofuran, toluene and chlorobenzene; the molar ratio of the compound of formula II to diphenylphosphine oxide is 1:1 to 1:2, preferably 1:1.2 to 1.5.

[0017] Preferably, in step 2, the second solvent is one of dichloromethane, dichloroethane, ethyl acetate, methanol, ethanol, chlorobenzene and toluene;

[0018] The oxidant is 30% hydrogen peroxide and / or 70% tert-butyl peroxide;

[0019] The catalyst is one or two of alum catalyst, heteropoly acid catalyst and heteropoly acid salt catalyst;

[0020] Preferably, the catalyst is vanadium pentoxide, phosphomolybdic acid or phosphotungstic acid.

[0021] Preferably, the ratio of the amount of the compound of formula IV to the oxidant substance is 1: 1.2 to 1: 5;

[0022] The amount of the catalyst used is 0.1% to 10% of the mass of the compound of formula IV.

[0023] Preferably, in step 2, the reaction progress is tracked by thin layer chromatography, and after the reaction is completed, the first product is filtered to obtain the first product; the filtrate is concentrated and recrystallized to obtain the second product, and the first product and the second product are combined to obtain the target product, compound of formula I.

[0024] Preferably, the reaction temperature in step 1 is 10-40°C, preferably room temperature;

[0025] Preferably, the reaction temperature in step 2 is 12-25°C.

[0026] Application of acylphosphine oxide compounds with chalcone structure in photocurable materials.

[0027] The advantages and positive effects of the present invention are: an acylphosphine oxide compound with a chalcone structure is obtained, the maximum absorption wavelength of which is red-shifted to varying degrees compared with TPO, with the maximum red shift being 21 nm; the molar absorption coefficient is much greater than that of TPO, with a maximum of 16 times the molar absorption coefficient of TPO;

[0028] Acylphosphine oxide compounds with a chalcone structure can be used as photoinitiators, have higher light absorption efficiency, and have better migration stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 UV-visible absorption spectra of the initiators. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0031] The present invention relates to an acylphosphine oxide photoinitiator having a chalcone structure and a preparation method thereof. First, an acylphosphine oxide compound having a chalcone structure is provided, the general structural formula of which is shown in Formula I;

[0032] Formula I;

[0033] Wherein R1, R2, R3, R4, and R5 are independently represented by H, C1-C 10 Alkyl, C1-C 10 Alkoxy, C1-C 10 Alkylthio, C1-C 10 one or more of dialkylamino and halogen; halogen is F, Cl or Br; preferably, R1, R2, R3, R4, R5 are independently represented by H, methyl, ethyl, propyl, methoxy, ethoxy, methylthio, ethylmercapto, dimethylamino and diethylamino, and R1, R2, R3, R4 and R5 are the same, partially the same or different.

[0034] The preparation method of the acylphosphine oxide compound having a chalcone structure comprises the following steps:

[0035] Step 1: reacting chalcone aldehyde (Formula II) with diphenylphosphine oxide (Formula III) in a first solvent. After the reaction is completed, filtering and washing with the first solvent to obtain an intermediate compound of Formula IV; the molar ratio of chalcone aldehyde II to diphenylphosphine oxide III is 1:1 to 1:2, preferably 1:1.2 to 1.5; the first solvent is one of dichloromethane, dichloroethane, ethyl acetate, cyclohexane, tetrahydrofuran, toluene, and chlorobenzene, preferably dichloromethane or dichloroethane; the reaction temperature is 10-40°C, preferably room temperature;

[0036]

[0037] Step 2: Add the intermediate represented by Formula IV to a second solvent, add a catalyst and an oxidant, stir and react, monitor the reaction progress by thin-layer chromatography, and filter after completion to obtain the product. The filtrate is concentrated and recrystallized, and then combined with the filtered filter cake to obtain the target product, Formula I. The second solvent is one of dichloromethane, dichloroethane, ethyl acetate, methanol, ethanol, chlorobenzene, or toluene, preferably ethyl acetate or dichloromethane. The oxidant is 30% hydrogen peroxide and / or 70% tert-butyl peroxide. The catalyst is one or more of vanadium pentoxide, heteropolyacid, and heteropolyacid salt, preferably vanadium pentoxide, phosphomolybdic acid, or phosphotungstic acid. The molar ratio of the intermediate represented by Formula IV to the oxidant is 1:1.2 to 1:5. The catalyst is used in an amount of 0.1% to 10% by weight of the intermediate represented by Formula IV, preferably 3% to 5%. The reaction temperature is 12°C to 25°C.

[0038]

[0039] In certain embodiments of the present invention, typical acylphosphine oxide compounds having the structures shown in Table 1 can be prepared according to the above-mentioned synthesis method. However, the above-mentioned contents are only preferred embodiments of the present invention and should not be considered as limiting the scope of the present invention.

[0040] Table 1 Structures of typical chalcone acylphosphine oxide initiators

[0041]

[0042] Introducing a chalcone structure into a phosphono-based photoinitiator molecule red-shifts the initiator's absorption wavelength and increases its light absorption capacity. Due to the conjugation effect between chalcone and acylphosphine oxide, the absorption wavelength can be red-shifted into the visible light range. Acylphosphine oxide compounds with a chalcone structure can be used as photoinitiators. Testing their UV-visible absorption spectra and comparing them with the commonly used photoinitiator TPO revealed that the maximum absorption wavelengths of the synthesized chalcone-based acylphosphine oxide photoinitiators were red-shifted to varying degrees compared to TPO, with a maximum red-shift of 21 nm. Their molar absorptivity was significantly greater than that of TPO, reaching a maximum of 16 times that of TPO. Acylphosphine oxide compounds with a chalcone structure exhibited higher light absorption efficiency and improved migration stability when used as photoinitiators.

[0043] The present invention is described below with reference to the accompanying drawings. Experimental methods without specific operating steps are carried out in accordance with the corresponding product specifications. Unless otherwise specified, the instruments, reagents, and consumables used in the examples can be purchased from commercial companies.

[0044] Example 1

[0045]

[0046] PI-1

[0047] Weigh 1.04 g (1.50 eq) of diphenylphosphine oxide into a 100 mL single-necked round-bottom flask, add 16 mL of ethyl acetate, and stir magnetically at room temperature until completely dissolved. Weigh 0.80 g (1.00 eq) of chalcone aldehyde II-1 (R1 = R2 = R3 = R4 = R5 = H) and add it to the above single-necked flask. Stir and react at room temperature for 11 h. Filter with suction, wash the filter cake with ethyl acetate (3 × 3 mL), and dry the filter cake to obtain 1.14 g of white solid product. 1.00 g (1.00 eq) of the above white solid was weighed into a 100 mL three-necked flask, 15 mL of dichloromethane was added, and the mixture was magnetically stirred at room temperature. 0.05 g of catalyst V2O5 was weighed and added to the above three-necked flask. 0.34 g (1.2 eq) of 70% tert-butyl hydroperoxide was weighed and added dropwise to the above three-necked flask at constant pressure. The reaction was stirred at room temperature for 18 h, filtered, and the filter cake was dried at 65°C to obtain 0.37 g of a white solid product, which was compound PI-1, with a yield of 37.2%.

[0048] 1H NMR (400 MHz, DMSO-d6) δ / ppm 8.18 (d, J = 7.8 Hz, 4H), 8.05 (d, J= 15.7 Hz, 2H), 8.00 (d, J = 8.9 Hz, 7H), 7.78 (d, J = 15.7 Hz, 2H), 7.69 (t,J = 7.3 Hz, 2H), 7.59 (t,J = 7.4 Hz, 4H).

[0049] 13 C NMR (101 MHz, DMSO-d6) δ / ppm 189.59, 167.32, 143.01, 139.21,137.82, 133.75, 132.61, 130.20, 129.92, 129.35, 129.26, 129.09, 124.66.

[0050] 31 P NMR (162 MHz, DMSO-d6) δ / ppm 29.52.

[0051] Example 2

[0052]

[0053] PI-2

[0054] Weigh 4.25 g (1.20 eq) of diphenylphosphine oxide into a 250 mL single-necked round-bottom flask. Add 160 mL of ethyl acetate and stir magnetically at room temperature until completely dissolved. Then, add 4.74 g (1.00 eq) of chalcone aldehyde II-2 (R1=R2=R4=R5=H, R3=Cl) to the same single-necked flask and stir at room temperature. Stop the reaction after complete reaction of diphenylphosphine oxide, as monitored by TLC. Filter, wash the filter cake with ethyl acetate (3 × 10 mL), and dry to yield 6.82 g of a white solid product. 4.50 g (1.00 eq) of the above white solid was weighed into a 100 mL three-necked flask, 40 mL of dichloromethane was added, and the mixture was stirred magnetically at room temperature. 0.07 g of catalyst V2O5 was weighed and added to the above three-necked flask. 4.90 g (1.2 eq) of 70% tert-butyl hydroperoxide was weighed and added dropwise to the above three-necked flask at constant pressure. The reaction was monitored by TLC to ensure completion. The reaction was filtered and the filter cake was dried at 65°C to obtain 2.87 g of a white solid product, which was compound PI-2, with a yield of 64.2%.

[0055] 1H NMR (400 MHz, DMSO-d6) δ / ppm 8.20 (d, J = 7.8 Hz, 4H), 8.00 (s,10H), 7.78 (d, J = 19.1 Hz, 2H), 7.63 (d, J = 7.8 Hz, 4H).

[0056] 13 C NMR (101 MHz, DMSO-d6) δ / ppm 188.44, 167.31, 167.16, 143.44,139.11, 138.81, 136.43, 136.02, 134.93, 134.68, 132.68, 131.90, 131.88,131.44, 131.34, 130.98, 130.19, 129.92, 129.42, 129.36, 129.15, 128.93,128.81, 124.28.

[0057] 31 P NMR (162 MHz, DMSO-d6) δ / ppm 23.38.

[0058] Example 3

[0059]

[0060] PI-3

[0061] Weigh 2.91 g (1.20 eq) of diphenylphosphine oxide into a 250 mL single-necked round-bottom flask, add 100 mL of ethyl acetate, and stir magnetically at room temperature until completely dissolved. Then, weigh 3.00 g (1.00 eq) of chalcone aldehyde II-3 (R1=R2=R4=R5=H, R3=CH3) and add it to the flask. Stir at room temperature and stop the reaction after complete reaction of diphenylphosphine oxide, as monitored by TLC. Filter, wash the filter cake with ethyl acetate (3 × 10 mL), and dry to yield 4.44 g of a white solid product. 3.50 g (1.00 eq) of the white solid was weighed into a 100 mL three-necked flask, and 20 mL of dichloromethane was added. The mixture was stirred magnetically at room temperature. 0.05 g of the catalyst, V2O5, was weighed and added to the flask. 3.99 g (4.00 eq) of 70% tert-butyl hydroperoxide was then added dropwise to the flask at a constant pressure. The reaction was monitored by TLC until completion. The mixture was filtered and the filter cake was dried at 65°C to yield 2.04 g of a white solid product, compound PI-3, in a yield of 58.6%.

[0062] 1H NMR (400 MHz, DMSO-d6) δ / ppm 8.28 (d, J = 8.6 Hz, 2H), 8.19-8.04(m, 8H), 7.84 (dd, J = 15.6, 7.7 Hz, 2H), 7.61-7.45 (m, 1H), 7.18 (d, J = 8.6Hz, 2H), 3.96 (s, 4H), 2.59 (s, 3H).

[0063] 13 C NMR (101 MHz, DMSO-d6) δ / ppm 188.98, 167.36, 167.18, 144.28,142.66, 139.31, 135.98, 135.33, 134.94, 134.64, 132.51, 131.91, 131.39,130.21, 129.90, 129.28, 128.95, 128.82, 124.67, 21.66

[0064] 31 P NMR (162 MHz, DMSO-d6) δ / ppm 23.39

[0065] Example 4 (Synthesis of Initiator PI-4)

[0066]

[0067] PI-4

[0068] Weigh 5.01 g (1.20 eq) of diphenylphosphine oxide into a 250 mL single-necked round-bottom flask. Add 100 mL of ethyl acetate and stir magnetically at room temperature until completely dissolved. Add 5.50 g (1.00 eq) of chalcone aldehyde II-4 (R1=R2=R4=R5=H, R3=OCH3) to the same single-necked flask and stir at room temperature. Stop the reaction after complete reaction of diphenylphosphine oxide by TLC monitoring. Filter the mixture, wash the filter cake with ethyl acetate (3 × 5 mL), and dry it to obtain 8.00 g of a white solid product. 2.50 g (1.00 eq) of the above white solid was weighed into a 100 mL three-necked flask, 90 mL of dichloromethane was added, and magnetic stirring was carried out at room temperature. 0.10 g of the catalyst V2O5 was weighed and added to the above three-necked flask. 5.70 g (4.00 eq) of 70% tert-butyl hydroperoxide was weighed and added dropwise to the above three-necked flask at constant pressure. The reaction was monitored by TLC until completion. The reaction was filtered and the filter cake was dried at 65°C to obtain 0.83 g of a white solid product, namely compound PI-4, with a yield of 33.7%.

[0069] 1 H NMR (400 MHz, DMSO-d6) δ / ppm 8.21 (d, J = 8.5 Hz, 3H), 8.09-7.93(m, 9H), 7.83-7.70 (m, 2H), 7.66 (d, J = 8.5 Hz, 3H), 7.54 – 7.44 (m, 1H),2.51 (s, 3H).

[0070] 13 C NMR (101 MHz, DMSO-d6) δ / ppm 195.29, 195.08, 167.29, 144.46,143.61, 138.86, 137.19, 136.45, 134.74, 132.66, 132.23, 131.80, 131.19,130.22, 129.27, 129.05, 128.92, 128.29, 20.56, 20.45.

[0071] 31 P NMR (162 MHz, DMSO-d6) δ / ppm 27.82.

[0072] Example 5

[0073]

[0074] PI-5

[0075] Weigh 6.68 g (1.40 eq) of diphenylphosphine oxide into a 250 mL single-necked round-bottom flask, add 170 mL of ethyl acetate, and stir magnetically at room temperature until completely dissolved. Then, weigh 6.00 g (1.00 eq) of chalcone aldehyde II-5 (R1=R2=R4=R5=H, R3=F) and add it to the flask. Stir at room temperature and react until the diphenylphosphine oxide completes the reaction. Stop the reaction by monitoring with TLC. Filter the mixture, wash the filter cake with ethyl acetate (3 × 5 mL), and dry it to yield 9.55 g of a white solid product. 6.00 g (1.00 eq) of the above white solid was weighed into a 100 mL three-necked flask, 30 mL of dichloromethane was added, and magnetic stirring was carried out at room temperature. 0.03 g of the catalyst V2O5 was weighed and added to the above three-necked flask. 6.77 g (4.00 eq) of 70% tert-butyl hydroperoxide was weighed and added dropwise to the above three-necked flask at constant pressure. The reaction was monitored by TLC until completion. The reaction was filtered and the filter cake was dried at 65°C to obtain 3.18 g of a white solid product, namely compound PI-5, with a yield of 53.2%.

[0076] 1H NMR (400 MHz, DMSO-d6) δ / ppm 8.25 (dd, J = 8.4, 5.7 Hz, 4H), 8.05-7.95 (m, 10H), 7.76 (d, J = 15.6 Hz, 2H), 7.38 (t, J = 8.7 Hz, 4H).

[0077] 13 C NMR (101 MHz, DMSO-d6) δ / ppm 188.04, 167.30, 164.36, 143.12,139.15, 134.48, 132.59, 132.04, 130.16, 129.37, 124.37, 116.38.

[0078] 31 P NMR (162 MHz, DMSO-d6) δ / ppm 23.55.

[0079] Example 6

[0080]

[0081] PI-6

[0082] Weigh 4.00 g (1.20 eq) of diphenylphosphine oxide into a 250 mL single-necked round-bottom flask. Add 150 mL of ethyl acetate and stir magnetically at room temperature until completely dissolved. Then, add 4.45 g (1.00 eq) of chalcone aldehyde II-6 (R1=R2=R3=R4=H, R5=Cl) to the same single-necked flask and stir at room temperature. Stop the reaction after complete reaction of diphenylphosphine oxide, as monitored by TLC. Filter the mixture, wash the filter cake with ethyl acetate (3 × 5 mL), and dry it to yield 8.00 g of a white solid product. 4.00 g (1.00 eq) of the above white solid was weighed into a 100 mL three-necked flask, 60 mL of dichloromethane was added, and the mixture was magnetically stirred at room temperature. 0.07 g of the catalyst V2O5 was weighed and added to the above three-necked flask. 4.40 g (4.00 eq) of 70% tert-butyl hydroperoxide was weighed and added dropwise to the above three-necked flask at constant pressure. The reaction was monitored by TLC to be complete. The mixture was filtered and the filter cake was dried at 65°C to obtain 2.38 g of a white solid product, namely compound PI-6, with a yield of 59.9%.

[0083] 1H NMR (400 MHz, DMSO-d6) δ / ppm 8.06-7.94 (m, 2H), 7.89 (d, J = 8.1Hz, 2H), 7.73 (dd, J = 11.4, 7.5 Hz, 4H), 7.63 – 7.34 (m, 12H).

[0084] 13 C NMR (101 MHz, DMSO-d6) δ / ppm 193.05, 166.81, 144.59, 138.41,138.19, 135.64, 134.30, 132.52, 132.13, 131.49 (d, J = 2.5 Hz), 131.01,130.91, 130.23, 130.09, 129.84, 129.50, 129.00, 128.54, 128.42, 128.17,127.49.

[0085] 31 P NMR (162 MHz, DMSO-d6) δ / ppm 23.49.

[0086] Example 7

[0087]

[0088] PI-7

[0089] Weigh 3.39 g (1.20 eq) of diphenylphosphine oxide into a 250 mL single-necked round-bottom flask, add 100 mL of ethyl acetate, and stir magnetically at room temperature until completely dissolved. Then, weigh 3.50 g (1.00 eq) of chalcone aldehyde II-7 (R1=R2=R3=R4=H, R5=CH3) and add it to the same single-necked flask. Stir the mixture at room temperature. Monitor the reaction by TLC until the diphenylphosphine oxide is completely reacted, then stop the reaction. Filter the mixture, wash the filter cake with ethyl acetate (3 × 5 mL), and dry it to obtain 5.76 g of a white solid product. 5.00 g (1.00 eq) of the above white solid was weighed into a 100 mL three-necked flask, 30 mL of dichloromethane was added, and magnetic stirring was carried out at room temperature. 0.05 g of the catalyst V2O5 was weighed and added to the above three-necked flask. 5.70 g (4.00 eq) of 70% tert-butyl hydroperoxide was weighed and added dropwise to the above three-necked flask at constant pressure. The reaction was monitored by TLC until completion. The reaction was filtered and the filter cake was dried at 65°C to obtain 2.55 g of a white solid product, namely compound PI-7, with a yield of 51.4%.

[0090] 1H NMR (400 MHz, DMSO-d6) δ / ppm 8.14-7.97 (m, 6H), 7.90-7.66 (m, 6H), 7.55-7.31 (m, 9H), 2.39 (d, J = 8.7 Hz, 2H).

[0091] 13 C NMR (101 MHz, DMSO-d6) δ / ppm 188.98, 167.36, 167.18, 144.28,142.66, 139.31, 135.98, 135.33, 134.94, 134.64, 132.51, 131.91 (d, J = 2.5Hz), 131.39 (d, J = 10.0 Hz), 130.21, 129.90 (d, J = 8.0 Hz), 129.28 (d, J =7.8 Hz), 128.95, 128.82, 124.67, 21.66.

[0092] 31 P NMR (162 MHz, DMSO-d6) δ / ppm 23.67.

[0093] Example 8

[0094]

[0095] PI-8

[0096] Weigh 4.00 g (1.20 eq) of diphenylphosphine oxide into a 250 mL single-necked round-bottom flask. Add 100 mL of ethyl acetate and stir magnetically at room temperature until completely dissolved. Then, add 4.45 g (1.00 eq) of chalcone aldehyde II-8 (R1=R2=R3=R5=H, R4=Cl) to the same single-necked flask and stir at room temperature. Stop the reaction after complete reaction of diphenylphosphine oxide, as monitored by TLC. Filter the mixture, wash the filter cake with ethyl acetate (3 × 5 mL), and dry it to yield 6.10 g of a white solid product. 4.50 g (1.00 eq) of the above white solid was weighed into a 100 mL three-necked flask, 30 mL of dichloromethane was added, and magnetic stirring was carried out at room temperature. 0.07 g of the catalyst V2O5 was weighed and added to the above three-necked flask. 4.90 g (4.00 eq) of 70% tert-butyl hydroperoxide was weighed and added dropwise to the above three-necked flask at constant pressure. The reaction was monitored by TLC until completion. The reaction was filtered and the filter cake was dried at 65°C to obtain 2.87 g of a white solid product, namely compound PI-8, with a yield of 64.2%.

[0097] 1H NMR (400 MHz, DMSO-d6) δ / ppm 8.23-7.97 (m, 6H), 7.84-7.67 (m, 6H), 7.59 (t, J = 7.8 Hz, 1H), 7.48 (dd, J = 12.7, 6.5 Hz, 7H).

[0098] 13 C NMR (101 MHz, DMSO-d6) δ / ppm 188.34, 167.31, 143.79, 139.60,139.08, 136.04, 134.38, 133.51, 132.74, 131.91, 131.62 – 131.14 (m), 130.17,129.93, 129.58, 129.10 – 128.66 (m), 127.70, 124.22.

[0099] 31 P NMR (162 MHz, DMSO-d6) δ / ppm 23.55.

[0100] Example 9 UV-visible absorption spectrum test

[0101] The compounds prepared in Examples 1-8 were used as photoinitiators, and acetonitrile solutions of the photoinitiators to be tested (5×10 -5 mol·L-1), and tested its UV-visible absorption spectrum. The photoinitiator TPO was used as the control group, and the molar concentration of TPO was 5×10 -4 mol·L -1 .

[0102] Table 2 Maximum absorption wavelength and molar absorption coefficient results of photoinitiators

[0103]

[0104] The results in Table 2 show that the maximum absorption wavelengths of the acylphosphine oxide initiators containing chalcone structures are all red-shifted to varying degrees compared with TPO, with the maximum red-shift being 21 nm; the molar absorptivity is much greater than that of TPO, with the maximum being about 16 times that of TPO.

[0105] Example 10 UV curing application test

[0106] The photoinitiators prepared in Examples 1-8 were mixed with acrylate-containing resins in varying proportions to prepare a photocurable system. The system was evenly coated onto a glass slide using a wire rod. The slide was placed on an energy meter and introduced into a photocuring machine via a conveyor. The UV irradiation duration was controlled by adjusting the transmission speed, and the degree of cure was assessed using a contact method. Complete cure was considered complete when the surface of the cured film showed no scratches or fingerprints after wiping with a paper towel or pressing with a finger. The energy meter reading at this point was recorded, representing the energy required for the system to cure.

[0107] Table 3 Curing energy results of photoinitiator-induced epoxy acrylate resin polymerization

[0108]

[0109] The results are shown in Table 3. When an equal amount of co-initiator EDB is added to the epoxy acrylate resin curing system, the energy of most photoinitiators to initiate resin polymerization is comparable to that of the commercial initiator TPO. These photoinitiators have the potential to replace TPO in practical applications and are expected to avoid the photoinitiator defects caused by the gradual ban on the use of TPO.

[0110] Example 11 Migration stability test

[0111] A photocuring system containing a photoinitiator (3 wt%), a difunctional amine-modified epoxy resin acrylate (94 wt%), and EDB (3 wt%) was prepared to test the photoinitiator migration performance. An equal mass of the formulation (30 mg) of the photocuring system was mixed and coated onto a glass slide to form a 10 mm × 25 mm × 1 mm transparent film. The film was then placed under a light intensity of 40 mW / cm 2 Irradiate the film under a mercury lamp for 3 minutes until the film is completely cured. Soak the treated glass slide in 10 mL of acetonitrile solution. After 5 days, select an appropriate amount of the extract for UV absorption testing. Calculate the mobility of the photoinitiator according to the following formula.

[0112] C = A / (ε·L) Formula 1;

[0113] R=100×C1 / C2 Formula 2;

[0114] In formula 1: A is λ max The absorbance at ; ε is the molar extinction coefficient, L·mol -1 cm -1 ; L is the optical path length. In this embodiment, the optical path length is 1 cm. C is the concentration of the photoinitiator in the solution. In Formula 2, C1 is the concentration of one of the initiators PI-1 to PI-8 prepared in Examples 1-8 in the extract, mol / L; C2 is the concentration of TPO in the extract; R is the relative mobility, %.

[0115] Table 4 Migration stability results of photoinitiators

[0116]

[0117] The results in Table 4 show that the synthesized photoinitiator has higher migration stability than the commercial photoinitiator TPO, and the best migration rate is only 10% of TPO. The mobility of the participating curing system is greatly improved, and it will not easily migrate to the surface of the material or into the food during use. Therefore, the initiator of the present invention has better light absorption ability than TPO and better migration stability.

[0118] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. An acylphosphine oxide compound having a chalcone structure, characterized in that: The structure is shown in Formula I; Formula I; Wherein, R1, R2, R3, R4, and R5 independently represent one or more of H, methyl, ethyl, propyl, methoxy, ethoxy, methylthio, ethylthio, dimethylamino, diethylamino, and halogen, and halogen is F, Cl, or Br; R1, R2, R3, R4, and R5 are the same, partially the same, or different.

2. The acylphosphine oxide compound having a chalcone structure according to claim 1, wherein: The structure of Formula I is shown in any one of Formulas 1-8; Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 Formula 7 Formula 8.

3. The method for preparing the acylphosphine oxide compound having a chalcone structure according to claim 1 or 2, characterized in that: The steps include: Step 1: placing the compound of formula II and diphenylphosphine oxide in a first solvent and reacting at 10-40° C. to obtain the compound of formula IV; Step 2: Add the compound of formula IV to a second solvent, add an oxidant and a catalyst, and stir to react to obtain a compound of formula I; Formula II; Formula IV.

4. The method for preparing an acylphosphine oxide compound having a chalcone structure according to claim 3, wherein: In step 1, the first solvent is one of dichloromethane, dichloroethane, ethyl acetate, cyclohexane, tetrahydrofuran, toluene and chlorobenzene; and the molar ratio of the compound of formula II to diphenylphosphine oxide is 1:1 to 1:

2.

5. The method for preparing an acylphosphine oxide compound having a chalcone structure according to claim 3, wherein: In step 2, the second solvent is one of dichloromethane, dichloroethane, ethyl acetate, methanol, ethanol, chlorobenzene and toluene; The oxidant is 30% hydrogen peroxide and / or 70% tert-butyl peroxide; The catalyst is one or two of a vanadium catalyst, a heteropolyacid catalyst and a heteropolyacid salt catalyst.

6. The method for preparing an acylphosphine oxide compound having a chalcone structure according to claim 5, wherein: The catalyst is vanadium pentoxide, phosphomolybdic acid or phosphotungstic acid.

7. The method for preparing an acylphosphine oxide compound having a chalcone structure according to claim 3, wherein: The molar ratio of the compound of formula IV to the oxidant substance is 1:1.2 to 1:5; The amount of the catalyst used is 0.1% to 10% of the mass of the compound of formula IV.

8. The method for preparing an acylphosphine oxide compound having a chalcone structure according to claim 3, wherein: In step 2, the reaction progress is tracked by thin layer chromatography, and after the reaction is completed, the first product is filtered to obtain the first product; the filtrate is concentrated and recrystallized to obtain the second product, and the first product and the second product are combined to obtain the target product, compound of formula I.

9. Use of the acylphosphine oxide compound having a chalcone structure according to claim 1 or 2 in a photocurable material.

10. The use according to claim 9, characterized in that: Used as a photoinitiator for preparing unsaturated resin compositions.

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