Derivative with benzophenone structure, preparation method of derivative, photopolymerizable composition and application of photopolymerizable composition as photoinitiator

Abstract

The invention provides a derivative with a benzophenone structure, a preparation method of the derivative, a photopolymerizable composition and application of the photopolymerizable composition as a photoinitiator. The photoinitiator shows excellent performance in a photopolymerization reaction, and can effectively catalyze the starting of the polymerization reaction especially under the irradiation of ultraviolet light. The compound not only has practical application value as a photoinitiator, but also is widely applied to preparation of various radiation curing materials due to high efficiency. The photoinitiator provided by the invention is suitable for producing, including but not limited to, photoresist, coating compositions, decorative and wear-resistant coatings, varnish, fiber reinforced composite materials, microelectronic packaging materials, plastic substrates, optical fiber coatings, molding materials, UV-cured structural resin and the like. These applications prove versatility and high efficiency of the compounds of formula (I) as photoinitiators.

Description

Technical Field

[0001] The present application relates to the technical field of organic photosensitizer materials, and more specifically, to a derivative having a benzophenone structure and a preparation method thereof, a photopolymerizable composition and the application thereof as a photoinitiator. Background Art

[0002] Photopolymerization technology is a process in which photoinitiators absorb light to provide a certain amount of energy, initiating the polymerization of monomers to form a curing system. It fully meets the "5E" characteristics: Efficient, Enabling, Economical, Energy Saving, and Environmental Friendly, and is therefore known as "green technology."

[0003] Photoinitiators, also known as photosensitizers or photocuring agents, are compounds that can absorb energy of a certain wavelength in the ultraviolet region (250-420nm) or visible region (400-800nm) to generate free radicals, cations and other active species, thereby initiating monomer polymerization, cross-linking and curing. Photoinitiators are the most important component in the photopolymerization process. Photoinitiators reach an excited state by absorbing light of a specific wavelength, and then generate active substances alone or through interaction with other additional compounds to further initiate polymerization, which can determine the polymerization efficiency under the irradiation of light of a specific wavelength.

[0004] Nowadays, photopolymerization photoinitiators have been widely used in industries such as lithography, coatings, inks, and dentistry. They can polymerize acrylic resins or epoxy resins, thereby giving the resins photopolymerization properties. Traditional thermal polymerization technology usually inevitably causes the release of volatile organic compounds (VOCs), which can be effectively avoided by photopolymerization technology. However, the photoinitiators currently on the market cannot meet the requirements of manufacturers due to their performance or price issues. Therefore, in the field of photopolymerization technology, there is still a need for photoinitiators with the advantages of higher activity, easy preparation, and easy handling.

[0005] Application Contents

[0006] In order to overcome at least one problem of the above-mentioned prior art, the present application provides a derivative having a benzophenone structure, which can be used as a photoinitiator. The photoinitiator needs to have the advantages of higher activity, easy preparation and easy handling.

[0007] Another object of the present application is to provide a photopolymerizable composition.

[0008] Another object of the present application is to provide a method for preparing the above-mentioned derivative having a benzophenone structure.

[0009] Another object of the present application is to provide application of the above-mentioned photopolymerizable composition in radiation curable materials.

[0010] In order to solve the above technical problems, the technical solution adopted in this application is:

[0011] A derivative having a benzophenone structure, which can be used as a photoinitiator, has a chemical structure shown in formula (I):

[0012]

[0013] Wherein, X is selected from any one of a sulfur atom, an oxygen atom or a carbonyl group;

[0014] R1 and R2 are independently selected from any one of the following structures:

[0015]

[0016] The present application also provides a photopolymerizable composition, comprising a compound as a photoinitiator and at least one ethylenically unsaturated photopolymerizable compound, wherein the compound as a photoinitiator is the above-mentioned derivative having a benzophenone structure.

[0017] Preferably, the ethylenically unsaturated photopolymerizable compound is an ester of an ethylenically unsaturated carboxylic acid and a polyol or an ester of an ethylenically unsaturated carboxylic acid and a polyepoxide.

[0018] More preferably, the ethylenically unsaturated photopolymerizable compound is acrylate, epoxy resin, acrylamide or a mixture thereof.

[0019] Preferably, a reactive co-initiator is also included, and the reactive co-initiator is a water-soluble tertiary amine or an iodonium salt.

[0020] More preferably, the reactive co-initiator comprises 0.5-5% by weight of the composition.

[0021] Preferably, the compound serving as a photoinitiator accounts for 0.01-5% by weight of the composition.

[0022] Preferably, it comprises N,N-dimethylacrylamide, a reactive co-initiator and a photoinitiator, wherein the N,N-dimethylacrylamide accounts for 95-98%, the reactive co-initiator accounts for 0.5-3%, and the photoinitiator accounts for 0.01-3%.

[0023] The present application also provides a method for preparing the above-mentioned derivative having a benzophenone structure, which comprises the following steps:

[0024] The donor and the acceptor are dissolved in an organic solvent, and an alkaline catalyst and a transition metal catalyst are added to react completely, and then post-treated. The obtained product and the acceptor are dissolved in an organic solvent again, and an alkaline catalyst and a transition metal catalyst are added to react completely, and then post-treated to obtain a derivative having a benzophenone structure.

[0025] The present application also provides the use of the above-mentioned photopolymerizable composition in radiation-curable materials, including pigmented and non-pigmented paints, varnishes, powder coatings, printing inks, printing plates, adhesives, photoresists, electronic component packaging materials, magnetic recording materials, 3D printing, micromechanical components, waveguides, optical converters, electroplating masks, color coating systems, glass fiber cable coatings, screen printing templates, and UV-curable structural resins.

[0026] Compared with the prior art, the beneficial effects of this application are:

[0027] The application provides a photoinitiator of formula (I), which exhibits excellent performance in photopolymerization, particularly under ultraviolet irradiation, and can effectively catalyze the start of polymerization. The compound not only has practical application value as a photoinitiator, but is also widely used in the preparation of a variety of radiation-cured materials due to its high efficiency. The photoinitiator of the application is suitable for the production of, including but not limited to, photoresists, coating compositions, decorative and wear-resistant coatings, varnishes, fiber-reinforced composite materials, microelectronic packaging materials, plastic substrates, optical fiber coatings, molding materials, and UV-cured structural resins. These applications have demonstrated the versatility and high efficiency of the compound of formula (I) as a photoinitiator. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The DMA monomer in the A1 / Iod system with different concentrations under LED@365nm irradiation is shown in Figure 2. 1 HNMR spectrum.

[0029] Figure 2 The DMA monomer in the A2 / Iod system with different concentrations under LED@365nm irradiation is shown in Figure 2. 1 HNMR spectrum.

[0030] Figure 3 Compound A1 prepared in Example 1 of the present invention 1 HNMR spectrum.

[0031] Figure 4 Compound A2 prepared in Example 2 of the present invention 1 HNMR spectrum.

[0032] Figure 5 Schematic diagram of the polymerization and curing effect of monomer DMA initiated by A1 / Iod and A2 / Iod systems under LED@365nm irradiation. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0034] It should be noted that:

[0035] In this application, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0036] In the present application, unless otherwise specified, each reaction or operation step can be carried out sequentially or in a sequential manner. Preferably, the reaction method herein is carried out sequentially.

[0037] Unless otherwise specified, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to the present application.

[0038] The present application provides a derivative having a benzophenone structure, which can be used as a photoinitiator compound, and has a chemical structure shown in formula (I):

[0039]

[0040] Wherein, X is selected from any one of a sulfur atom, an oxygen atom or a carbonyl group;

[0041] R1 and R2 are independently selected from any one of the following structures:

[0042]

[0043] More specifically, the derivative having a benzophenone structure provided in the present application can be used as a photoinitiator and has a structure of one of the following structures:

[0044]

[0045]

[0046] Another object of the present application is a method for preparing a benzophenone derivative having a donor-acceptor structure of formula (I), the method comprising the following steps:

[0047] The donor and the acceptor are dissolved in an organic solvent, and an alkaline catalyst and a transition metal catalyst are added to react completely, and then post-treated. The obtained product and the acceptor are dissolved in an organic solvent again, and an alkaline catalyst and a transition metal catalyst are added to react completely, and then post-treated to obtain;

[0048] In some preferred embodiments, during the reaction, the molar ratio of the donor to the acceptor is 1:1 to 4:1, and the molar ratio of the product to the acceptor is 1:1 to 1:2.

[0049] In some preferred embodiments, the organic solvent for the reaction is toluene or 1,4-dioxane.

[0050] In some preferred embodiments, the chemical structure of the receptor is as follows:

[0051]

[0052] Wherein, B is a halogen, and X is selected from a sulfur atom, an oxygen atom or a carbonyl group.

[0053] In some preferred embodiments, the halogen is F, Cl, Br or I.

[0054] The present application provides a type of photoinitiator of formula I, which exhibits excellent performance in photopolymerization reactions, particularly under ultraviolet light irradiation, and can effectively catalyze the start of polymerization reactions. The compound not only has practical application value as a photoinitiator, but is also widely used in the preparation of a variety of radiation-cured materials due to its high efficiency. The photoinitiator of the present application is suitable for the production of, including but not limited to, photoresists, coating compositions, decorative and wear-resistant coatings, varnishes, fiber-reinforced composite materials, microelectronic packaging materials, plastic substrates, optical fiber coatings, molding materials, and UV-cured structural resins. These applications demonstrate the versatility and high efficiency of the compound of formula I as a photoinitiator. In one aspect of the present application, a photopolymerizable composition is provided, comprising: a compound (a) as a photoinitiator and at least one ethylenically unsaturated photopolymerizable compound (b), wherein the structural formula of the compound (a) of the photoinitiator is as follows:

[0055]

[0056]

[0057] In one embodiment of the present application, the photopolymerizable composition may further contain other known photoinitiators. These photoinitiators include, but are not limited to, camphorquinone, benzophenone and its derivatives, acetophenone and its derivatives, benzil ketal, phenylglyoxylic acid and its derivatives, diacetyl compounds and peresters. These additional photoinitiators can synergize with the photoinitiator of formula (I) to improve the photopolymerization efficiency or adapt to different application requirements.

[0058] In one aspect of the present application, the photoinitiator of the photopolymerizable composition generally comprises 0.01-5% by weight of the composition, preferably 0.01-3% by weight, and most preferably 0.05-3% by weight. If a mixture of photoinitiators is used in the composition, the amount refers to the sum of all added photoinitiators, that is, the amount refers to the amount of photoinitiator (a), or the amount of photoinitiator (a) plus other photoinitiators. The concentration can be selected according to the application thickness. A combination of two or more photoinitiators can also be used to obtain the best possible curability of the formulated composition. The minimum amount of photoinitiator that can initiate curing and achieve the desired use intensity on the production line is preferred. The selection of this amount depends on the characteristics of the polymer composition, the type of radiation source, the amount of radiation received, the speed of the production line, and the thickness of the coating on the substrate.

[0059] In the photopolymerizable composition of the present application, the ethylenically unsaturated photopolymerizable compound in component (b) is a compound commonly used in the art. Examples of monomers containing double bonds of the photopolymerizable compound are methacrylamide, isobornyl acrylate, and the ethylenically unsaturated photopolymerizable compound includes one or more ethylenic double bonds. The ethylenically unsaturated 2-phenoxyethyl acrylate, N,N-dimethylacrylamide, etc. are formed. Examples of monomers containing two or more double bonds are 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, 1,3-propylene glycol diacetate, etc.

[0060] In one aspect of the present application, the ethylenically unsaturated photopolymerizable compound is an acrylated epoxy resin, an alkyl acrylate or a mixture thereof, most preferably epoxy acrylate, trimethylolpropane triacrylate or a mixture thereof.

[0061] The ethylenically unsaturated photopolymerizable compound contained in component (b) may be one kind thereof, or a mixture of two kinds thereof, or a mixture of two or more kinds thereof.

[0062] In the photopolymerizable composition of the present application, component (b) ethylenically unsaturated photopolymerizable compound is generally used in an amount of about 90% to about 99%, preferably about 92% to about 98%, more preferably about 95% to 98%.

[0063] The photopolymerizable composition provided in the present application may further contain other additives.

[0064] In one aspect of the present application, the additive contained in the photopolymerizable composition is a reactive co-initiator (c),

[0065] For example, water-soluble tertiary amines or iodonium salts, such as triethanolamine, N-methyl-diethanolamine, N,N-dimethylethanolamine, aliphatic tertiary amines (such as acrylated aliphatic tertiary amines) or diphenyliodonium hexafluorophosphate, etc. The reactive co-initiator in the photopolymerizable composition of the present application usually accounts for 0.5-5% by weight of the composition, and most preferably 0.5-3%.

[0066] In the photopolymerizable composition of the present application, in addition to the photoinitiator, other types of additives may also be included. For example, in order to prevent uncontrolled premature polymerization reactions, thermal inhibitors may be added, including hydroquinone, hydroquinone derivatives, p-methoxyphenol, 3-naphthol or sterically hindered phenols, etc. In order to exclude oxygen during the polymerization process to avoid its interference, paraffin or similar waxy substances may be added to the composition. In addition, in order to improve the light stability of the composition, a light stabilizer, such as a UV absorber, may be added in small amounts. The addition of these additives helps to optimize the polymerization process and improve the performance of the final product.

[0067] In the art, a series of other known additives are also included, such as flow promoters and adhesion promoters. The selection of these additives will be based on the specific application requirements and the performance characteristics expected in the application field. Since these additives are widely used in the art, their addition amount usually follows the conventional amount in the industry.

[0068] In one aspect of the present application, there is provided the above-mentioned photopolymerizable composition, which comprises:

[0069] Ethylenically unsaturated photopolymerizable compounds 10-99%

[0070] Reactive co-initiator 0.1-10%

[0071] Photoinitiator 0.01-10% wherein the photoinitiator is

[0072]

[0073]

[0074] In one aspect of the present application, there is provided the above-mentioned photopolymerizable composition, which comprises:

[0075] N,N-dimethylacrylamide 95-98%

[0076] Reactive amine co-initiator 0.5-3%

[0077] Photoinitiator 0.01-3%

[0078] The present application relates to a photopolymerizable material, which is sensitive to light in the range of 300 to 450 nanometers from ultraviolet to visible light. The material can be irradiated with natural light or artificial light, thereby providing the possibility of multiple light source selection. Depending on the intended application of the material and the type and output intensity of the light source, the distance between the light source and the substrate to be exposed can be adjusted. In addition, it is also possible to consider irradiating with lasers in the visible light range.

[0079] Another object of the present application is to create a photolithographic pattern, in particular to form a photolithographic pattern on a metal substrate. A preferred method for achieving this object is to use a photopolymerization system consisting of reactive oligomers and / or monomers containing ethylenically unsaturated groups, non-reactive polymers (such as polyacrylates) and at least one compound of a specific structure. This mixture is exposed to light with a wavelength in the ultraviolet to visible light region, up to 450 nanometers, through a negative film, and after a suitable development process, a photolithographic pattern can be formed.

[0080] Another feature of the present application is the various application fields of its photopolymer materials. These applications include, but are not limited to, the production of pigmented and non-pigmented paints, varnishes, powder coatings, printing inks, printing plates, adhesives, photoresists for the electronics industry, packaging materials for electrical and electronic components, magnetic recording materials, micromechanical components, waveguides, optical converters, electroplating masks, etching masks, color coating systems, glass fiber cable coatings, screen printing templates, and the manufacture of three-dimensional objects using stereolithography.

[0081] Next, the preparation method of the boron-containing conjugated aromatic hydrocarbon fluorescent dye in the present application is described in detail with specific examples.

[0082] Example 1 Preparation of Photoinitiator A1

[0083] The preparation and synthesis route of photoinitiator A1 is as follows:

[0084]

[0085] The preparation method of photoinitiator A1 comprises the following steps:

[0086] 3.49 g of 4-fluoro-2-chlorobenzoic acid and 4.48 g of m-fluorophenol were dissolved in N, N-dimethylformamide, and heated at 120-150°C for 6-12 hours under the catalysis of 4.54 g of potassium carbonate and 0.2 g of copper powder. The reaction solution was cooled to room temperature and filtered to remove inorganic salts. Sulfuric acid was added to the filtrate to adjust the pH to 1 and stirred overnight. The product was filtered and then separated and purified by silica gel column chromatography using petroleum ether / dichloromethane (volume ratio 4:1) as the eluent to obtain compound C. 1a .

[0087] Add compound C into a 100 mL round-bottom flask. 1a Then, 30 mL of concentrated sulfuric acid was added, and the mixture was heated at 90-100°C for 6-10 h. The reaction solution was cooled to room temperature, poured into 500 mL of ice, and filtered to obtain a solid. The solid was then separated and purified by silica gel column chromatography using petroleum ether / dichloromethane (volume ratio 2:1) as the eluent to obtain receptor B. 1a .

[0088] 423mg diphenylamine, 232mg receptor B 1a , t-BuOK: 336 mg was dissolved in 20 mL N, N-dimethylformamide. Under nitrogen protection, the above reactants were heated to 100-120 ° C for 8-12 hours. After the reaction was completed, the reaction solution was cooled to room temperature and extracted with ethyl acetate and saturated brine three times. The organic phase was taken and the ethyl acetate was evaporated under reduced pressure to obtain a crude product. Then, it was separated and purified by silica gel column chromatography with petroleum ether / dichloromethane (volume ratio 1:1) as eluent to obtain photoinitiator A. 1。

[0089] Example 2 Preparation of Photoinitiator A2

[0090] The preparation and synthesis route of photoinitiator A2 is as follows:

[0091]

[0092] The preparation method of photoinitiator A2 comprises the following steps:

[0093] 2.35 g of 4-bromo-2-fluorobenzoic acid and 1.78 g of m-bromothiophenol were dissolved in N, N-dimethylformamide, and heated at 120-150°C for 6-12 hours under the catalysis of 4.2 g of potassium carbonate and 0.2 g of copper powder. The reaction solution was cooled to room temperature and filtered to remove inorganic salts. Sulfuric acid was added to the filtrate to adjust the pH to 1 and stirred overnight. The product was filtered and then separated and purified by silica gel column chromatography using petroleum ether / dichloromethane (volume ratio 4:1) as the eluent to obtain compound C. 2a .

[0094] Add compound C into a 100 mL round-bottom flask. 2a Then, 30 mL of concentrated sulfuric acid was added, and the mixture was heated at 90-100°C for 6-10 h. The reaction solution was cooled to room temperature, poured into 500 mL of ice, and filtered to obtain a solid. The solid was then separated and purified by silica gel column chromatography using petroleum ether / dichloromethane (volume ratio 2:1) as the eluent to obtain receptor B. 2a .

[0095] 507mg diphenylamine, 350mg receptor B 2a, 31.5mg Pd(dba)3, 58mg t-BuXPhos, 1.92gK2CO3, dissolved in 20mL toluene, heated to 100-120°C under nitrogen protection for 8-12h. After the reaction, the reaction solution was cooled to room temperature, and extracted with dichloromethane and saturated brine for 3 times. The organic phase was taken, and dichloromethane was evaporated under reduced pressure to obtain a crude product. Then, the product was separated and purified by silica gel column chromatography with petroleum ether / dichloromethane (volume ratio 1:1) as eluent to obtain photoinitiator A2.

[0096] Example 3 Preparation of UV Curing Agent

[0097] Prepare the UV curing agent according to the following formula.

[0098] The specific formula is as follows:

[0099] N,N-dimethylacrylamide 95-98%

[0100] Reactive co-initiator 0.5-3%

[0101] Photoinitiator 0.01-3%

[0102] According to the above formula, A1 and A2 were used as photoinitiators to prepare the invention preparation 1.

[0103] Example 4 Curing effect test

[0104] 0.2 ml of the UV curable preparation prepared in Example 3 was taken and heated to 10 mW / cm 2 The samples were irradiated with a 365 nm LED light for 1 min, and nuclear magnetic resonance hydrogen spectrum was detected using a Bruker 400 MHz superconducting nuclear magnetic resonance instrument and deuterated chloroform as solvent to record the polymerization effect.

[0105] A photoinitiator system consisting of different concentrations of photoinitiator A1 or A2 and 0.5 mol% Iod was used, 0.2 mL of DMA monomer was added, deoxygenated in dark, ultrasonically mixed, and the irradiation time was controlled, and irradiated for 1 min under a 365 nm LED lamp. After irradiation, the monomers were cured to varying degrees. Internal standards of mesitylene and deuterated chloroform were added to each irradiated sample to dissolve. 1 The monomer conversion rate was obtained by HNMR nuclear magnetic resonance comparison.

[0106] The test method of monomer conversion rate is as follows: mesitylene is used as the internal standard (the integral signal (6.76-6.82 ppm) is set to 1). Select the specific hydrogen (H A ) to monitor the changes of monomers under UV irradiation. At the beginning (0s), H AThe integral value of is H0, and when the sample is treated with UV light for t seconds, H A The integral value is H t .

[0107] The conversion formula is:

[0108] Figure 1 The DMA monomer in the A1 / Iod system with different concentrations under LED@365nm irradiation is shown in Figure 2. 1 HNMR spectrum.

[0109] Figure 2 The DMA monomer in the A2 / Iod system with different concentrations under LED@365nm irradiation is shown in Figure 2. 1 HNMR spectrum.

[0110] from Figure 1 It can be seen that at LED@365nm, the power is 10mW / cm 2 Under the condition of 1 The conversion rate monitored by HNMR showed a trend of increasing first and then decreasing, and the viscosity of the sample gradually increased with the increase of UV LED irradiation time. When the content of photoinitiator was 0.06wt%, the conversion rate could reach 97.57%.

[0111] from Figure 2 It can be seen that at LED@365nm, the power is 10mW / cm 2 Under the condition of 1 The conversion rate monitored by HNMR showed a trend of increasing first and then decreasing, and the viscosity of the sample gradually increased with the increase of UV LED irradiation time. When the content of photoinitiator was 0.06wt%, the conversion rate could reach 93.51%.

[0112] Table 1: Calculated conversion rate of DMA in A1 / Iod or A2 / Iod system under LED@365nm irradiation

[0113]

[0114] The photoinitiators A1 and A2 obtained in Examples 1 and 2 were characterized as

[0115] Compound structure detection: The molecular hydrogen spectrum of the photoinitiator A1 prepared in Example 1 was obtained by using a Bruker 400 MHz superconducting nuclear magnetic resonance instrument and the solvent was deuterated chloroform. Figure 3 As shown. Figure 3 It can be seen that: 1H NMR (400MHz, Chloroform-d) δ8.10 (d, J = 8.9 Hz, 2H), 7.39-7.31 (m, 8H), 7.24-7.09 (m, 12H), 6.92 (dd, J = 8.9, 2.3 Hz, 2H), 6.73 (d, J = 2.2 Hz, 2H). Combined with the above NMR results, it can be seen that the product obtained in Example 1 is A1.

[0116] The molecular hydrogen spectrum of the photoinitiator A2 prepared in Example 2 is as follows: Figure 4 As shown. Figure 4 It can be seen that: 1 H NMR (400MHz, Chloroform-d) δ8.37 (d, J = 9.0 Hz, 2H), 7.38-7.30 (m, 8H), 7.22-7.11 (m, 12H), 7.01 (dd, J = 9.0, 2.3 Hz, 2H), 6.90 (d, J = 2.3 Hz, 2H). Combined with the above NMR results, it can be seen that the product obtained in Example 2 is A2.

[0117] Figure 5 This is a schematic diagram of the polymerization and curing effect of the monomer DMA initiated by the A1 / Iod and A2 / Iod systems under LED@365nm irradiation, that is, a schematic diagram of the polymerization effect when the content is 0.06wt%. Figure 5 It can be seen that the photoinitiator molecules can react with the iodonium salt co-initiator under light to initiate the polymerization and curing of the monomer DMA. After curing, there is no liquid flow, which indicates that the photoinitiator molecules can generate free radicals through energy transfer and electron transfer with the iodonium salt co-initiator in the UV curing system, thereby initiating the polymerization of the monomer.

[0118] The present application provides a derivative having a benzophenone structure, which can be used as a photoinitiator compound, and has a chemical structure shown in formula (I):

[0119]

[0120] Wherein, X is selected from any one of a sulfur atom, an oxygen atom or a carbonyl group;

[0121] R1 and R2 are independently selected from any one of the following structures:

[0122]

[0123] The present application also provides a photopolymerizable composition, which includes a compound as a photoinitiator and at least one ethylenically unsaturated photopolymerizable compound, wherein the compound as a photoinitiator is the above-mentioned derivative having a benzophenone structure.

[0124] In summary, the photoinitiator provided by the present application shows excellent performance in photopolymerization reaction, especially under ultraviolet light irradiation, and can effectively catalyze the start of polymerization reaction. The compound not only has practical application value as a photoinitiator, but is also widely used in the preparation of various radiation-cured materials due to its high efficiency. The photoinitiator of the present application is suitable for the production of materials including but not limited to photoresists, coating compositions, decorative and wear-resistant coatings, varnishes, fiber-reinforced composite materials, microelectronic packaging materials, plastic substrates, optical fiber coatings, molding materials, and UV-cured structural resins. These applications prove the versatility and high efficiency of the compound of formula (I) as a photoinitiator.

[0125] The present application also provides a photopolymerizable material, whose light sensitivity range covers the ultraviolet to visible light region of 300 to 450 nanometers. This material can be irradiated using natural light or artificial light sources, thereby providing the possibility of multiple light source selections. Depending on the intended application of the material and the type and output intensity of the light source, the distance between the light source and the substrate to be exposed can be adjusted. In addition, it is also possible to consider using lasers in the visible light range for irradiation.

[0126] Another object of the present application is to create a photolithographic pattern, in particular to form a photolithographic pattern on a metal substrate. A preferred method for achieving this object is to use a photopolymerization system consisting of reactive oligomers and / or monomers containing ethylenically unsaturated groups, non-reactive polymers (such as polyacrylates) and at least one compound of a specific structure. This mixture is exposed to light with a wavelength in the ultraviolet to visible light region, up to 450 nanometers, through a negative film, and after a suitable development process, a photolithographic pattern can be formed.

[0127] Another feature of the present application is the various application fields of its photopolymer materials. These applications include, but are not limited to, the production of pigmented and non-pigmented paints, varnishes, powder coatings, printing inks, printing plates, adhesives, photoresists for the electronics industry, packaging materials for electrical and electronic components, magnetic recording materials, micromechanical components, waveguides, optical converters, electroplating masks, etching masks, color coating systems, glass fiber cable coatings, screen printing templates, and the manufacture of three-dimensional objects using stereolithography.

[0128] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0129] Although several embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A derivative having a benzophenone structure, which can be used as a photoinitiator, characterized in that: It has a chemical structure shown in formula (I): Wherein, X is selected from any one of a sulfur atom, an oxygen atom or a carbonyl group; R1 and R2 are independently selected from any one of the following structures:

2. A photopolymerizable composition, characterized in that: The invention comprises a compound as a photoinitiator and at least one ethylenically unsaturated photopolymerizable compound, wherein the compound as a photoinitiator is the derivative having a benzophenone structure as claimed in claim 1.

3. The photopolymerizable composition according to claim 2, characterized in that The ethylenically unsaturated photopolymerizable compound is an ester of an ethylenically unsaturated carboxylic acid and a polyol or an ester of an ethylenically unsaturated carboxylic acid and a polyepoxide.

4. The photopolymerizable composition according to claim 3, characterized in that The ethylenically unsaturated photopolymerizable compound is acrylate, epoxy resin, acrylamide or a mixture thereof.

5. The photopolymerizable composition according to claim 2, characterized in that Also included is a reactive co-initiator, which is a water-soluble tertiary amine or an iodonium salt.

6. The photopolymerizable composition according to claim 5, characterized in that The reactive co-initiator comprises 0.5-5% by weight of the composition.

7. A photopolymerizable composition according to any one of claims 2 to 7, characterised in that The compound as photoinitiator accounts for 0.01-5% by weight of the composition.

8. The photopolymerizable composition according to claim 2, characterized in that The invention comprises N,N-dimethylacrylamide, a reactive co-initiator and a photoinitiator, wherein the N,N-dimethylacrylamide accounts for 95-98%, the reactive co-initiator accounts for 0.5-3%, and the photoinitiator accounts for 0.01-3%.

9. The method for preparing the derivative having a benzophenone structure according to claim 1, characterized in that: The steps include: The donor and the acceptor are dissolved in an organic solvent, and an alkaline catalyst and a transition metal catalyst are added to react completely, and then post-treated. The obtained product and the acceptor are dissolved in an organic solvent again, and an alkaline catalyst and a transition metal catalyst are added to react completely, and then post-treated to obtain a derivative having a benzophenone structure.

10. Use of the photopolymerizable composition of claims 2 to 9 in radiation curable materials, including pigmented and non-pigmented paints, varnishes, powder coatings, printing inks, printing plates, adhesives, photoresists, electronic component packaging materials, magnetic recording materials, 3D printing, micromechanical components, waveguides, optical converters, electroplating masks, color coating systems, glass fiber cable coatings, screen printing templates, and UV curing structural resins.

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