Ketoximate ester photoinitiator compound with allyloxy double bond introduced at the ortho position of carbonyl group, preparation method and application thereof

Abstract

The present invention provides a ketoxime ester photoinitiator compound that introduces an allyloxy double bond at the ortho position of a carbonyl group, and its preparation method and application. The ketoxime ester photoinitiator compound can decompose under light-excited conditions to produce a benzoyl radical, and can form a carbon-centered free radical by an intramolecular cyclization reaction. On the one hand, this new active species can trigger the polymerization of unsaturated double bonds. On the other hand, no benzaldehyde-like by-products are generated in the curing system, which reduces the odor of the curing formula and can also effectively reduce the yellowing effect of the formula. The prepared ketoxime ester derivative has good light absorption and photoinitiation efficiency in the near-ultraviolet-visible light region. In particular, it has a wide range of applications in the field of LED light curing in the UVA and UVB bands as a low-migration, low-odor photoinitiator for radiation curing, and in the field of radiation curing formulas, especially in the field of UV-LED-excitable light curing coatings or ink industrialization.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical synthesis and photocuring, and specifically relates to the structure of a UV-sensitive photoinitiator-type compound derived by introducing an allyloxy double bond at the ortho position of a carbonyl group, a preparation method thereof, and applications in the field of photocuring, in particular applications in free radical UV curing formulations. Background Art

[0002] Photocurable materials (such as photocurable coatings, inks, and photoresists) are primarily composed of unsaturated resins and their monomers. To enable polymerization and crosslinking reactions under irradiation with ultraviolet light, visible light, lasers, and other light sources, highly sensitive photoinitiators must be added. These photoinitiators, when exposed to light sources of a certain wavelength, generate reactive groups (such as free radicals and cations), which trigger polymerization of the unsaturated groups and lead to crosslinking and curing of the photocurable material.

[0003] Aryl oxime esters or aromatic ketone oxime esters are a class of photoinitiators with a wide range of uses. The most typical ones are the commercial oxime ester initiators OXE-01 and OXE-02, whose molecular structures are shown below:

[0004]

[0005] Of course, these photoinitiators also have certain drawbacks or deficiencies. For example, the commercial oxime ester initiator OXE-01 can undergo cleavage at certain wavelengths, converting into phenyl radicals and benzoyl radicals. The latter have weaker initiation properties and are prone to hydrogen transfer reactions with hydrogen donors, generating strongly odorous aldehyde-containing photolysis products that remain in the UV-curable formulation. This inevitably limits the application of these photoinitiators in areas such as food packaging and biopharmaceutical materials. These issues are key technical challenges currently facing the UV-curable field.

[0006]

[0007] In response to the above problems and technical challenges, the present invention designs and proposes a new type of photoinitiator, which can not only improve the initiation performance of the photoinitiator, but also reduce the odor and toxicity of the photocuring formula, and is the key to solving these problems. Summary of the Invention

[0008] In response to the shortcomings of the prior art, the first object of the present invention is to provide a ketoxime ester photoinitiator-type compound derived from an allyloxy double bond introduced at the ortho position of the carbonyl group. The compound utilizes the characteristics of the benzoyl radical after photolysis of the photoinitiator to undergo intramolecular cyclization with the ortho-allyloxy double bond to form highly active carbon free radicals, while also solving the technical problems of existing commercial photoinitiators such as easy migration, yellowing, and strong odor.

[0009] The second object of the present invention is to provide a method for preparing the above-mentioned ketoximate ester photoinitiator compound derived from an allyloxy double bond introduced at the ortho position of the carbonyl group.

[0010] The third object of the present invention is to provide the use of the above-mentioned ketoxime ester photoinitiator compound derived from an allyloxy double bond introduced at the ortho position of the carbonyl group in the field related to photocuring.

[0011] To achieve the above object, the solution of the present invention is:

[0012] A ketoxime ester photoinitiator compound having an allyloxy double bond introduced at the ortho position of the carbonyl group: in its molecular structure, the allyloxy double bond must be introduced at the ortho position of the carbonyl group and cannot be other types of olefin substituents. Its molecular structure is shown in general formula (I):

[0013]

[0014] in,

[0015] R1 and R2 are selected from C1-C 20 Straight chain alkyl, C1-C 20 Branched alkyl, C3-C 12 Cycloalkyl, heterocyclic alkyl, C6-C 12 One or more of benzene and alkylbenzenes;

[0016] R3, R4, R5, and R6 are independently selected from hydrogen atoms, halogen atoms, CN, NO2, CF3, R, OR, SR, SOR, SO2R, and NRR', wherein R and R' are C1-C 24 Straight or branched alkyl or C6-C 24 Aryl, hydrogen atoms in the structures of R and R' can be replaced by fluorine atoms to form a fluorocarbon chain structure. When R and R' exist at the same time, they can also form a 3-6 membered ring structure. One or more -CH2- in R and R' can be independently replaced by -O-, -N-, -S-, -CO-, -COO-, -OCO- or a benzene ring;

[0017] R7, R8, and R9 are each independently selected from at least one of a hydrogen atom and a methyl group.

[0018] Furthermore, a ketoxime ester photoinitiator compound with an allyloxy double bond introduced at the ortho position of the carbonyl group undergoes photoexcitation decomposition under certain light conditions, with the NO bond being homolytically cleaved, releasing carbon dioxide and small nitrile molecules, and releasing R1 free radicals with higher initiation activity and benzoyl free radicals with lower initiation activity. The benzoyl free radical undergoes intramolecular cyclization with the allyloxy group to form a highly active carbon-centered free radical. The activity of the carbon-centered free radical is much higher than that of the original benzoyl free radical. The mechanism is as follows:

[0019]

[0020] A method for preparing the ketoxime ester photoinitiator compound having an allyloxy double bond introduced at the ortho position of the carbonyl group as described above comprises the following steps:

[0021] (a) An acyl chloride containing R2 substitution and a phenol substituted with R3, R4, R5, or R6 substitution are subjected to an esterification reaction at room temperature in an organic solvent under the protection of an inert gas using a base as an acid-binding agent to obtain intermediate (I)-a:

[0022]

[0023] (b) Under inert gas protection, add intermediate (I)-a and anhydrous AlCl3 in equal moles to a flask, heat to 140-150°C, and keep warm for 3-6 hours to obtain intermediate (I)-b:

[0024]

[0025] (c) Intermediate (I)-b and allyl bromide substituted by R7, R8, or R9 are heated under reflux in an organic solvent under the catalysis of K2CO3 until the raw materials disappear, and then subjected to conventional post-treatment to obtain intermediate (I)-c:

[0026]

[0027] (d) Under the protection of inert gas, the intermediate (I)-c was dissolved in tetrahydrofuran, and then 5.0 moles of concentrated hydrochloric acid was added. Finally, an equimolar amount of isoamyl nitrite was added dropwise with stirring, and the reaction was carried out at room temperature to obtain the intermediate (I)-d:

[0028]

[0029] (e) Under the protection of inert gas and in the dark, the intermediate (I)-d and the acyl chloride containing R1 substitution are subjected to esterification reaction at room temperature using a base as an acid binding agent to obtain the target product (I):

[0030]

[0031] The overall preparation process is as follows:

[0032]

[0033] Furthermore, in step (a), the base is selected from one or more of triethylamine, potassium carbonate, sodium hydride or sodium hydroxide.

[0034] Furthermore, in step (a), the organic solvent is selected from one or more of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, toluene, and dichloromethane.

[0035] Furthermore, in step (c), the organic solvent is selected from one or more of chloroform, dichloromethane, and tetrahydrofuran.

[0036] Furthermore, in step (e), the base is selected from one or more of triethylamine and potassium carbonate.

[0037] Furthermore, in step (a), step (b), step (d) and step (e), the inert gas is selected from nitrogen or argon, preferably nitrogen.

[0038] Furthermore, the method further comprises subjecting the intermediates and the final product (I) obtained in each step of the reaction to conventional extraction and washing, wherein the organic solvent used for the extraction and washing is ethyl acetate or dichloromethane; the intermediates and the final product can be purified by recrystallization or column chromatography.

[0039] A ketoxime ester photoinitiator compound having an allyloxy double bond introduced at the ortho position of the carbonyl group as described above is used as a photoinitiator in a photocuring formulation system or as an intermediate, raw material or reagent in chemical synthesis.

[0040] Furthermore, the light-curing formulation system includes:

[0041] (1) Containing at least one compound of the general formula (I) as a photoinitiator or one of the photoinitiator components;

[0042] (2) containing at least one polymerizable compound containing an unsaturated double bond;

[0043] (3) The amount of the compound of formula (I) is 0.5-10 parts by weight per 100 parts by weight of the total amount of polymerizable components in the system;

[0044] (4) A small amount of additives, defoaming agents, leveling agents, dyes, and inorganic fillers can be added to the formulation system of the initiator.

[0045] Furthermore, the polymerizable compound containing an unsaturated double bond is selected from at least one of various methacrylate monomers and resins.

[0046] Preferably, the methacrylate monomer is selected from at least one of monofunctional methyl methacrylate (MMA), difunctional 1,6-hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), trifunctional trimethylolpropane triacrylate (TMPTA), and pentaerythritol triacrylate (PETA). The resin also contains acrylate functional groups, for example, one or more selected from polyurethane acrylates and silicone acrylates.

[0047] Furthermore, the auxiliary agent is selected from one or more of acetone and dichloromethane.

[0048] Furthermore, the defoamer is solvent-based defoamer BYK-055.

[0049] Furthermore, the leveling agent is organic silicone leveling agent BYK-370.

[0050] Furthermore, the dye is selected from one or more of titanium dioxide, zinc oxide, lithopone, carbon black, and graphite.

[0051] Furthermore, the inorganic filler is selected from one or more of nano-silicon dioxide and zirconium dioxide.

[0052] Further, some representative molecular structures of the present invention are as follows:

[0053]

[0054] Due to the adoption of the above solution, the beneficial effects of the present invention are:

[0055] First, advantages in structure and performance: The present invention introduces a ketoxime ester photoinitiator compound derived from an allyloxy double bond at the ortho-position of the carbonyl group. The benzoyl radical generated by photolysis at a certain wavelength can undergo intramolecular cyclization with the double bond of the ortho-allyl group to form an alkyl carbon radical with high initiation efficiency. This process overcomes the relatively low reactivity of the benzoyl radical, resulting in better photopolymerization speed and double bond conversion when used in photocurable formulations than initiators without ortho-allyloxy groups. On the other hand, the benzoyl radical in the system may cause toxicity and odor problems in the photocurable system. The introduction of an allyloxy group at the ortho-position can help overcome these shortcomings. The compound has good sensitivity within the light radiation range, resulting in advantages such as a wide range of applicable wavelengths, high photolysis efficiency, and good compatibility with monomers and resins.

[0056] Second, advantages in application: The ketoxime ester photoinitiator compound provided by the present invention, which is derived from an allyloxy double bond and introduced at the ortho position of the carbonyl group, has the advantages of good solubility, good formula stability, and low migration performance for the application scenario of photocurable formulations. It is also effectively compatible with free radical curing resins and can be compounded to form storage-stable photocurable inks or coatings; in addition, the raw materials in the preparation process are simple and easy to obtain, the synthesis route is simple, the cost is low, and the synthesis process is environmentally friendly, with less three wastes, which is convenient for preparation and large-scale production.

[0057] Third, advantages in practical application effects: The present invention introduces a ketoxime ester photoinitiator compound derived from an allyloxy double bond at the ortho position of the carbonyl group. After application in a photocuring formula, no coupling product of benzoyl free radicals, benzil compounds, is generated in the system, which effectively reduces the yellowing of the system and demonstrates a good anti-yellowing advantage. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 1 is a general formula diagram of the ketoxime ester photoinitiator compound of the present invention.

[0059] Figure 2 The (I)-1 in CDCl3 in Example 1 of the present invention 1 H NMR spectrum.

[0060] Figure 3 For Example 2 of the present invention (I)-4 in CDCl3 1 H NMR spectrum.

[0061] Figure 4 The concentration of PI-1 in CDCl3 in Comparative Example 1 of the present invention is 1 H NMR spectrum.

[0062] Figure 5 The PI-2 in CDCl3 in Comparative Example 2 of the present invention 1 H NMR spectrum.

[0063] Figure 6 This is the UV-visible absorption spectrum of the molecules synthesized by (I)-1 and (I)-4 in acetonitrile solution in Examples of the present invention.

[0064] Figure 7 This is a Photo-DSC curve of the free radical polymerization of TPGDA thick film initiated by the molecules of (I)-1, (I)-4, and OXE-01 in the examples of the present invention under the excitation of 365nm LED light.

[0065] Figure 8This is a Photo-DSC curve of the free radical polymerization of TPGDA thick film initiated by the molecules of (I)-1 and (I)-4 in the examples of the present invention and PI-1 and PI-2 in the comparative example under 365nm LED light excitation.

[0066] Figure 9 This is the ultraviolet absorption spectrum of the TPGDA polymerization film initiated by the molecules of (I)-1, (I)-4, OXE-01 in the examples of the present invention and PI-1 and PI-2 in the comparative example under 365nm LED light excitation after being soaked in acetonitrile for 72 hours. DETAILED DESCRIPTION

[0067] The present invention provides a ketoxime ester photoinitiator compound with an allyloxy double bond introduced at the ortho position of a carbonyl group, a preparation method and application thereof.

[0068] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0069] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0070] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0071] Example 1: Synthesis of (I)-1, the reaction scheme is as follows:

[0072]

[0073] Step (a): Phenol (9.40 g, 0.1 mol) and triethylamine (12.12 g, 0.12 mol) were dissolved in 100 mL of anhydrous dichloromethane, cooled to below 5° C. with an ice-water bath, and slowly added dropwise propionyl chloride (11.04 g, 0.12 mol) dissolved in 50 mL of dichloromethane through a constant pressure dropping funnel under nitrogen protection and stirring. After the addition was completed for 1 h, the mixture was stirred at room temperature for 5 h and monitored by thin layer chromatography. After the reaction of the raw materials was completed, the generated salt was filtered off, and the dichloromethane solution was washed with saturated sodium chloride aqueous solution and water, dried over anhydrous sodium sulfate, and then the solvent was evaporated to obtain 14.25 g of intermediate (I)-1a, with a purity of 98% by liquid chromatography and a yield of 95.0%.

[0074] Step (b): Intermediate (I)-1a (14.25 g, 0.095 mol) and anhydrous aluminum chloride (13.3 g, 0.1 mol) were added to a 100 mL flask under nitrogen protection, heated to 150° C. in an oil bath for 3 h, and the reaction system was converted from liquid to solid and cooled to room temperature. The product was dissolved in 1 mol / L dilute hydrochloric acid, extracted with dichloromethane, washed with saturated brine and deionized water, dried, evaporated to dryness, and vacuum distilled to obtain 9.26 g of colorless liquid intermediate (I)-1b. The purity was 98% by liquid chromatography analysis, and the yield was 65%.

[0075] Step (c): Intermediate (I)-1b (9.26 g, 0.062 mol), potassium carbonate (12.83 g, 0.093 mol) and allyl bromide (9.00 g, 0.074 mol) were added to 50 mL of acetone and refluxed under nitrogen for 6 h. The reaction was completed, and the solvent was evaporated. The remaining mixture was extracted with dichloromethane, and the organic phase was washed with water. After evaporating the solvent, a colorless liquid was obtained, which was the target product (I)-1c (11.25 g in total). The purity was 98.0% by liquid chromatography analysis, and the yield was 95.5%.

[0076] Step (d): Intermediate (I)-1c (11.25 g, 0.062 mol) and concentrated hydrochloric acid (30.6 g, 0.31 mol) were dissolved in 100 mL of tetrahydrofuran, cooled to below 5°C with an ice-water bath, and slowly added dropwise isoamyl nitrite (7.25 g, 0.062 mol) dissolved in 50 mL of tetrahydrofuran through a constant pressure dropping funnel under nitrogen protection and stirring. After the addition was completed for 1 hour, the mixture was stirred at room temperature for 5 hours and monitored by thin layer chromatography. After the reaction of the raw materials was completed, the mixture was diluted with water, extracted with ethyl acetate, and washed several times with saturated brine. The organic layer was evaporated to dryness to obtain a light yellow liquid, thereby obtaining 11.57 g of intermediate (I)-1d, with a purity of 98% by liquid chromatography analysis and a yield of 85.2%.

[0077] Step (e): The intermediate (I)-1d (11.57 g, 0.053 mol) and triethylamine (6.46 g, 0.064 mol) were dissolved in 100 mL of anhydrous dichloromethane, cooled to below 5°C with an ice-water bath, and slowly added dropwise acetyl chloride (5.02 g, 0.064 mol) dissolved in 50 mL of dichloromethane through a constant pressure dropping funnel under nitrogen protection and stirring. After the addition was completed for 1 hour, the mixture was stirred at room temperature for 5 hours and monitored by thin layer chromatography. After the reaction of the raw materials was completed, the generated salt was filtered off, and the dichloromethane solution was washed with saturated sodium chloride aqueous solution and water, dried over anhydrous sodium sulfate, and then the solvent was evaporated to give a crude product. The crude product was purified by petroleum ether / dichloromethane column chromatography to give 12.73 g of the target product (I)-1. The purity was 98% by liquid chromatography analysis, and the yield was 92.0%.

[0078] NMR of target product (I)-1: 1 H NMR (400MHz, CDCl3) δ7.62(d,J=8.0Hz,1H),7.48(t,J=8.0Hz,1H),7.03(t,J=8.0Hz,1H) ,7.00(d,J=8.0Hz,1H),5.98(m,1H),5.24(m,2H),4.54(m,2H),2.23(s,3H),2.17(s,3H).

[0079] MS(C 14 H 15 NO4): m / e: 261.10; experimental result: 262.11 (M+H + ).

[0080] Specific NMR spectra can be found in Figure 2 .

[0081] Example 2: Synthesis of (I)-4, the reaction scheme is as follows:

[0082]

[0083] The specific steps were similar to those in Example 1, except that acetyl chloride in step (e) was replaced with benzoyl chloride. All other steps were the same as in Example 1. The yields and purities of steps (a) to (d) were similar, with the yield in step (e) being 90.0%.

[0084] NMR of target product (I)-4: 1 H NMR (400MHz, CDCl3) δ8.10(d,J=8.0Hz,2H),7.71(d,J=8.0Hz,1H),7.63(t,J=8.0Hz,1H),7.50–7.65(m ,3H),7.04(t,J=8.0Hz,1H),7.00(d,J=8.0Hz,1H),5.98(m,1H),5.22(m,2H),4.61(m,2H),2.41(s,3H).

[0085] MS(C 19 H 17 NO4): m / e: 323.35; experimental result: 324.36 (M+H + ).

[0086] Specific NMR spectra can be found in Figure 3 .

[0087] Example 3: Synthesis of (I)-7, the reaction scheme is as follows:

[0088]

[0089] The specific steps are similar to those in Example 1, except that propionyl chloride in step (a) is replaced with butyryl chloride. The other steps are the same as those in Example 1. The yields and purities of the remaining steps are similar.

[0090] MS(C 15 H 17 NO4): m / e: 275.30; experimental result: 276.31 (M+H + ).

[0091] Comparative Example 1: Synthesis of photoinitiator PI-1 without double bonds. The reaction route is as follows:

[0092]

[0093] The specific steps were similar to those in Example 1, except that n-butyl bromide was used in place of allyl bromide in step (c). The other steps were the same as in Example 1. The yields and purities of steps (a) to (d) were similar, with a yield of 92.0% in step (c).

[0094] NMR of target product PI-1: 1 H NMR (400MHz, CDCl3) δ7.65(d,J=8.0Hz,1H),7.51(t,J=8.0Hz,1H),7.03(t,J=8.0Hz,1H),6.95(d,J=8.0Hz,1H),4.00(t, J=7.2Hz,2H),2.26(s,3H),2.20(s,3H),1.70(td,J=7.2,5.4Hz,2H),1.43(td,J=7.2,5.4Hz,2H),0.96(t,J=7.2Hz,3H).

[0095] MS(C 15 H 19 NO4): m / e: 277.13; experimental result: 278.14 (M+H + ).

[0096] Specific NMR spectra can be found in Figure 4 .

[0097] Comparative Example 2: Synthesis of photoinitiator PI-2 without double bonds. The reaction route is as follows:

[0098]

[0099] The specific steps are similar to those in Comparative Example 1, except that acetyl chloride in step (e) is replaced with benzoyl chloride. All other steps are the same as those in Comparative Example 1. The yields and purities of steps (a) to (d) are similar, with the yield in step (e) being 85.0%.

[0100] NMR of target product PI-2: 1 H NMR (400MHz, CDCl3) δ8.10(d,J=8.0Hz,2H),7.62(d,J=8.0Hz,1H),7.50–7.65(m,3H),7.48(t,J=8.0Hz,1H),7.03(t,J=8.0Hz,1H),7.00(d,J =8.0Hz,1H),4.02(t,J=7.2Hz,2H),2.26(s,3H),2.20(s,3H),1.71(td,J=7.2,5.4Hz,2H),1.40(td,J=7.2,5.4Hz,2H),0.87(t,J=7.2Hz,3H).

[0101] MS(C 20 H 21 NO4): m / e: 339.15; experimental result: 340.16 (M+H + ).

[0102] Specific NMR spectra can be found in Figure 5 .

[0103] <Experiment 1>

[0104] The UV-visible absorption spectra and related photophysical parameters of the target products in different embodiments were tested.

[0105] Accurately weigh a certain amount of the sample in the embodiment, dissolve it in a volumetric flask, and then test the UV-visible absorption spectrum. The specific curve is as follows Figure 6 The maximum absorption wavelength, the molar extinction coefficient at the maximum absorption wavelength and the molar extinction coefficient at 365 nm are shown in Table 1.

[0106] Table 1 Photophysical parameters of two ketoxime ester photoinitiators in acetonitrile solution in the embodiment

[0107]

[0108] Experiment 2

[0109] (I)-1, (I)-4, PI-1, PI-2 and OXE-01 in a formulation containing acrylate monomers were subjected to LED@365nm light curing experiments and coating property tests:

[0110] Prepared according to the following formula (by weight percentage)

[0111] Bifunctional acrylate resin (tripropylene glycol diacrylate, TPGDA): 98%

[0112] Photoinitiators (I)-1, (I)-4, PI-1, PI-2, and OXE-01: 2%

[0113] The mixture prepared in the above example was applied to a cardboard to form a coating of about 25-30 μm. A coating with a unit power of 1000 mW / cm2 produced by Guangzhou Heguang Tongsheng Technology Co., Ltd. was used. 2 An LED light source with an emission wavelength of 365 nm (a 3 cm wide and 80 cm long LED surface light source) was used as the excitation light source and placed on a variable speed conveyor belt. The criterion for photopolymerization curing to be complete was that no marks were left by repeated pressure and scratching with a fingernail.

[0114] The results showed that the compounds of this example were all cured efficiently at a speed higher than 25 m / min.

[0115] The coating obtained by light curing was tested for hardness by a hand-cranked pencil hardness tester, and its hardness was measured to be 3H. The photopolymerization kinetic curve of the formulation system under the excitation of a 365nm LED light source was tested by Photo-DSC, and the conversion rate of the acrylate double bond was calculated based on the heat release. The specific curve is shown in FIG. Figure 7 as well as Figure 8 As shown. It can be found that the initiated polymerization effects of the three initiators are all better. Compared with OXE-01, the double bond conversion rates of (I)-1 and (I)-4 initiated polymerization are all higher, and the highest can reach 73%. Compared with (I)-4, the initiation efficiency of (I)-1 is higher, indicating that the initiation activity of the ketoxime ester substituted by acetyl chloride is higher than that of the photoinitiator substituted by benzoyl. Compared with PI-1 and PI-2 in the comparative example, the photoinitiator (I)-1 and (I)-4 synthesized in the embodiment have a higher photoinitiator efficiency, indicating that the photoinitiator synthesized by the mode of introducing allyl group in the ortho position has a photoinitiator efficiency higher than that of n-butyl. That is, this design scheme can play the purpose of improving the initiation efficiency of photoinitiator.

[0116] The cured coating was crushed and weighed to 1.00 g, then immersed in 20 mL of acetonitrile for 72 hours. Before testing the UV absorption spectrum of the immersion solution, the solution was diluted to 40 times, 40 times, 40 times, 40 times, and 280 times. Combining the UV absorption spectrum and the molar extinction coefficients of different photoinitiators measured so far, the concentration of the photoinitiator in the immersion solution can be calculated, and thus its mobility can be calculated. The specific curve is as follows: Figure 9 As shown. The mobilities of Examples (I)-1, (I)-4, Comparative Examples PI-1, PI-2, and OXE-01 were 2.7%, 3.2%, 10.4%, 10.8%, and 11.5%, respectively. Compared with Comparative Examples PI-1, PI-2, and the commercialized OXE-01, the small molecule mobilities in Examples (I)-1 and (I)-4 were significantly reduced, indicating that the photoinitiator in the designed solution has low mobility.

[0117] The above description of the embodiments is intended to facilitate understanding and use of the present invention by those skilled in the art. Those skilled in the art will readily be able to make various modifications to these embodiments and apply the general principles described herein to other embodiments without resorting to creative effort. Therefore, the present invention is not limited to the above-described embodiments. Any improvements or modifications made by those skilled in the art based on the principles of the present invention that do not depart from the scope of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A ketoxime ester photoinitiator compound having an allyloxy double bond introduced at the ortho position of the carbonyl group, characterized in that: Its molecular structure is shown in the general formula (I): in, R1 and R2 are selected from C1-C 20 Straight chain alkyl, C1-C 20 Branched alkyl, C3-C 12 One or more of cycloalkyl and phenyl; R3, R4, R5, and R6 are independently selected from hydrogen atoms, halogen atoms, CN, NO2, CF3, R, OR, SR, SOR, SO2R, and NRR', wherein R and R' are C1-C 24 Straight or branched alkyl or C6-C 24 aryl; R7, R8, and R9 are independently selected from one or more of a hydrogen atom and a methyl group; Or selected from the following compounds: 。 2. The ketoxime ester photoinitiator compound having an allyloxy double bond introduced at the ortho position of the carbonyl group according to claim 1, characterized in that: In the R and R' structures, fluorine atoms are used to replace hydrogen atoms to form a fluorocarbon chain structure.

3. The method for preparing a ketoxime ester photoinitiator compound having an allyloxy double bond introduced at the ortho position of the carbonyl group according to claim 1 or 2, characterized in that: It includes the following steps: (a) An acyl chloride containing R2 substitution and a phenol substituted with R3, R4, R5, or R6 substitution are subjected to room temperature esterification reaction in an organic solvent under inert gas protection using a base as an acid-binding agent to obtain intermediate (I)-a: ； (b) Under inert gas protection, add the intermediate (I)-a and anhydrous AlCl3 in equal moles to a flask, heat to 140-150°C, and keep warm for 3-6 hours to obtain intermediate (I)-b: ； (c) The intermediate (I)-b and allyl bromide substituted with R7, R8, and R9 are heated under reflux in an organic solvent under the catalysis of K2CO3 until the raw materials disappear, and then the intermediate (I)-c can be prepared by conventional post-treatment: ； (d) Under the protection of inert gas, the intermediate (I)-c is dissolved in tetrahydrofuran, and then 5.0 moles of concentrated hydrochloric acid are added. Finally, an equimolar amount of isoamyl nitrite is added dropwise under stirring, and the reaction is carried out at room temperature to obtain intermediate (I)-d: ； (e) In the absence of light and under the protection of inert gas, the intermediate (I)-d is subjected to an esterification reaction at room temperature with an acyl chloride containing R1 substitution using a base as an acid binding agent to obtain the target product (I): 。 4. The preparation method according to claim 3, wherein: In step (a), the base is selected from at least one of triethylamine, potassium carbonate, sodium hydride or sodium hydroxide.

5. The preparation method according to claim 3, wherein: In step (a), the organic solvent is selected from at least one of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, toluene, and dichloromethane.

6. The preparation method according to claim 3, wherein: In step (c), the organic solvent is selected from at least one of chloroform, dichloromethane, and tetrahydrofuran.

7. The preparation method according to claim 3, wherein: In step (e), the base is selected from at least one of triethylamine and potassium carbonate.

8. The preparation method according to claim 3, wherein: In step (a), step (b), step (d) and step (e), the inert gas is selected from nitrogen or argon.

9. The preparation method according to claim 3, wherein: The method further comprises extracting and washing the intermediates and the final product (I) obtained in each step, wherein the organic solvent used for the extraction and washing is ethyl acetate or dichloromethane; the intermediates and the final product can be purified by recrystallization or column chromatography.

10. Use of the ketoxime ester photoinitiator compound having an allyloxy double bond introduced at the ortho position of the carbonyl group as claimed in claim 1 as a photoinitiator in a photocuring formulation system.

11. The use according to claim 10, characterized in that: The light-curing formulation system comprises: (1) Containing at least one compound of the general formula (I) as a photoinitiator or one of the photoinitiator components; (2) Containing at least one polymerizable compound containing an unsaturated double bond; (3) The amount of the compound of formula (I) is 0.5-10 parts by weight per 100 parts by weight of the total amount of polymerizable components in the system; (4) Adding additives, defoamers, leveling agents, dyes, and inorganic fillers to the formulation system of the initiator; The auxiliary agent is selected from one or more of acetone and dichloromethane; The defoamer is a solvent-based defoamer BYK-055; The leveling agent is organic silicon leveling agent BYK-370; The dye is selected from one or more of titanium dioxide, zinc oxide, lithopone, carbon black, and graphite; The inorganic filler is selected from one or more of nano-silicon dioxide and zirconium dioxide.

12. The use according to claim 11, characterized in that: The polymerizable compound containing an unsaturated double bond is selected from at least one of methacrylate monomers and resins.

13. The use according to claim 12, characterized in that: The methacrylate monomer is selected from at least one of methyl methacrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate.

14. The use according to claim 12, characterized in that: The resin is selected from one or more of polyurethane acrylate and silicone acrylate.

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