Biphenyl derivative photoinitiator and preparation method thereof, photocuring film material and preparation method and application thereof

Abstract

The invention discloses a biphenyl derivative photoinitiator, a preparation method of the biphenyl derivative photoinitiator, a photocuring thin film material and a preparation method and application of the photocuring thin film material. The biphenyl derivative has a structural formula shown as a formula (I), R1 is an electron donor group, and R2 is an electron acceptor group. According to the invention, biphenyl is taken as a main body structure, different donor groups R1 and acceptor groups R2 are connected, the photoinitiator is synthesized through Suzuki reaction, and a polymeric monomer material is N, N-dimethylacrylamide (DMA). The photocuring material with long afterglow luminescence can be obtained through an ultraviolet irradiation method, and under the irradiation of a 365nm ultraviolet lamp, an initiator absorbs photons to generate active species to attack double bonds in a monomer to initiate a polymerization reaction. The light-cured film can generate long afterglow luminescence as long as several seconds after being illuminated, and can be applied to the aspects of counterfeiting prevention, 3D printing, photoetching and the like.

Description

Technical Field

[0001] The present application relates to the technical field of organic light-emitting materials, and more specifically, to a biphenyl derivative photoinitiator and a preparation method thereof, a photocurable film material and a preparation method and application thereof. Background Art

[0002] Free radical photopolymerization in photocuring technology has attracted much attention due to its greenness, environmental protection and fast reaction speed. Photoinitiators play a very important role in free radical polymerization, which affects the polymerization rate and the physical strength of the polymer after polymerization. Therefore, photoinitiators with excellent performance have always been a research hotspot. Among them, photoinitiators require non-toxicity, no yellowing, and low cost, which are the goals pursued by researchers.

[0003] However, the synthesis of photoinitiator materials in the prior art is relatively complex and the yield is not high. In addition, in the polymerization process, additional initiators such as iodonium salts and sulfonium salts need to be added, which increases the cost. Therefore, it is necessary to further find photoinitiator materials with excellent performance.

[0004] Application Contents

[0005] In order to overcome one of the problems existing in the above-mentioned prior art, the primary purpose of the present application is to provide a biphenyl derivative photoinitiator, which is a biphenyl derivative connected with an acceptor group and a donor group to synthesize a class of photoinitiator compounds through Suzuki reaction.

[0006] Another object of the present application is to provide a method for preparing the above-mentioned biphenyl derivative photoinitiator.

[0007] Another object of the present application is to provide a photocurable film material comprising the above-mentioned biphenyl derivative photoinitiator.

[0008] Another object of the present application is to provide the application of the above-mentioned biphenyl derivative photoinitiator.

[0009] The above-mentioned purpose of this application is achieved through the following technical solutions:

[0010] A biphenyl derivative photoinitiator having a molecular structure as shown in the following formula (I):

[0011]

[0012]

[0013] Wherein, R1 is an electron donor group, and R1 is selected from any one of the following groups:

[0014]

[0015] Wherein, R2 is an electron acceptor group, and R2 is selected from any one of the following groups:

[0016]

[0017] The biphenyl derivative in the present application is added as a photoinitiator to the monomer DMA, and a film material with a long afterglow luminescence phenomenon is obtained after photocuring. This type of film material shows a green long afterglow emission after being irradiated by a 365nm ultraviolet lamp. According to the long afterglow characteristics of the photocured film, it can be applied to anti-counterfeiting and information encryption.

[0018] The present application also provides a method for preparing the above-mentioned biphenyl derivative photoinitiator, comprising the following steps:

[0019] Under the protection of inert gas, 4-biphenylboric acid, R-Br, tetrakistriphenylphosphine palladium, potassium carbonate aqueous solution and tetrahydrofuran mixed solvent are reacted together at 50-70° C. for 5-10 hours to obtain a biphenyl derivative having a structure shown in formula (I).

[0020] The present application provides a photocurable film material, comprising a photoinitiator and an olefin monomer, wherein the olefin monomer is N,N-dimethylacrylamide, and the photoinitiator is the above-mentioned biphenyl derivative.

[0021] Preferably, the doping mass fraction of the photoinitiator material in the monomer material in the present application is 0.2%.

[0022] The present application also provides a method for preparing the above-mentioned photocurable film material, comprising the following steps:

[0023] S1. Weigh the photoinitiator material into a clean and dry container, add the monomer until it is completely dissolved to prepare a solution before light curing;

[0024] S2. The mass fraction of the photoinitiator material doped in the monomer material is 0.2%, and the formula solution is evenly applied on a glass slide, and then the formula solution is cured by irradiating the photocurable film material with an ultraviolet lamp for 120 seconds to obtain a photocurable film.

[0025] Preferably, the monomer in step S1 is N,N-dimethylacrylamide.

[0026] Preferably, in step S2, the initiator is dissolved in the poly (N,N-dimethylacrylamide) solution, and the initiator sample is completely dissolved by ultrasound.

[0027] More preferably, the wavelength of the ultraviolet lamp is 365nm and the power is 10mW / cm 2 .

[0028] The above-mentioned photocurable film materials are used in the fields of anti-counterfeiting, 3D printing and photolithography.

[0029] Compared with the prior art, the beneficial effects of this application are:

[0030] The present invention connects different electron donor groups R1 and electron acceptor R2 to biphenyl, and synthesizes biphenyl derivatives through Suzuki reaction. The donor and acceptor of the biphenyl derivative form a DA structure, which can effectively reduce the singlet-triplet energy level difference (ΔE ST ), thereby promoting self-selected orbital coupling, thereby generating more triplet excitons. The synthesis of biphenyl derivatives by Suzuki reaction has simple synthesis steps and high yield, and the monomer material DMA is an easily available and cheap industrial production monomer, and the polymerized polymer has good physical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The biphenyl derivative A1 prepared in Example 1 of the present application 1 HMNR diagram.

[0032] Figure 2 The biphenyl derivative A2 prepared in Example 2 of the present application 1 HMNR diagram.

[0033] Figure 3 This is a diagram of the degree of polymerization of DMA monomer initiated by the biphenyl derivative A1 prepared in Example 1 of the present application.

[0034] Figure 4 This is a diagram of the degree of polymerization of DMA monomer initiated by the biphenyl derivative A2 prepared in Example 2 of the present application.

[0035] Figure 5 This is a diagram of the polymerization mechanism of DMA monomer initiated by the photoinitiator biphenyl derivative A1 prepared in Example 1 of the present application.

[0036] Figure 6 The present invention relates to the application of the photocurable film in the field of anti-counterfeiting.

[0037] Figure 7 Schematic diagram of the polymerization of monomers initiated by initiators. DETAILED DESCRIPTION

[0038] 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.

[0039] It should be noted that:

[0040] 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.

[0041] In the present application, unless otherwise specified, percentage (%) or part refers to the weight percentage or weight part relative to the composition.

[0042] In the present application, unless otherwise specified, the components or preferred components involved can be combined with each other to form a new technical solution.

[0043] In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviation of any real number combination between a and b, where a and b are real numbers. For example, the numerical range "1-5" means that all real numbers between "1-5" are listed in this document, and "1-5" is just an abbreviation of these numerical combinations.

[0044] The "range" disclosed in the present application is in the form of a lower limit and an upper limit, which can be one or more lower limits, and one or more upper limits, respectively.

[0045] In the present application, unless otherwise specified, each reaction or operation step can be carried out sequentially or in accordance with the sequence. Preferably, the reaction method herein is carried out sequentially.

[0046] 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.

[0047] The present application provides a biphenyl derivative photoinitiator having a molecular structure as shown in the following formula (I):

[0048]

[0049] Wherein, R1 is an electron donor group, and R1 is selected from any one of the following groups:

[0050]

[0051] Wherein, R2 is an electron acceptor group, and R2 is selected from any one of the following groups:

[0052]

[0053] The present invention connects different electron donor groups R1 and electron acceptor R2 to biphenyl, and synthesizes biphenyl derivatives through Suzuki reaction. The donor and acceptor of the biphenyl derivative form a DA structure, which can effectively reduce the singlet-triplet energy level difference (ΔEST ), thereby promoting self-selected orbital coupling, thereby generating more triplet excitons. The synthesis of biphenyl derivatives by Suzuki reaction has simple synthesis steps and high yield, and the monomer material DMA is an easily available and cheap industrial production monomer, and the polymerized polymer has good physical properties.

[0054] In some preferred embodiments, the biphenyl derivative photoinitiator of the present application can be selected from any one of the following structural formulas:

[0055]

[0056] In some preferred embodiments, the present application also provides a method for preparing the above-mentioned biphenyl derivative photoinitiator, comprising the following steps:

[0057] Under the protection of inert gas, 4-biphenylboric acid, R-Br, tetrakistriphenylphosphine palladium, potassium carbonate aqueous solution and tetrahydrofuran mixed solvent are reacted together at 50-70° C. for 5-10 hours to obtain a biphenyl derivative having a structure shown in formula (I).

[0058] The present application also provides a photocurable film material, comprising a photoinitiator and an olefin monomer, wherein the olefin monomer is N,N-dimethylacrylamide, and the photoinitiator is the above-mentioned biphenyl derivative.

[0059] In some preferred embodiments, the doping mass fraction of the photoinitiator material in the photocurable film material in the present application in the monomer material is 0.2%.

[0060] The present application also provides a method for preparing the above-mentioned photocurable film material, comprising the following steps:

[0061] S1. Weigh the photoinitiator material into a clean and dry container, add the monomer until it is completely dissolved to prepare a solution before light curing;

[0062] S2. The mass fraction of the photoinitiator material doped in the monomer material is 0.2%, and the formula solution is evenly applied on a glass slide, and then the formula solution is cured by irradiating the photocurable film material with an ultraviolet lamp for 120 seconds to obtain a photocurable film.

[0063] In some preferred embodiments, the monomer in step S1 is N,N-dimethylacrylamide.

[0064] In some preferred embodiments, in step S2, the initiator is dissolved in the poly (N,N-dimethylacrylamide) solution, and the initiator sample is completely dissolved by ultrasound.

[0065] In some preferred embodiments, the wavelength of the ultraviolet lamp is 365nm and the power is 10mW / cm 2 .

[0066] The present application also provides applications of the above-mentioned photocurable film material in the fields of anti-counterfeiting, 3D printing and photolithography.

[0067] The preparation method of the biphenyl derivative photoinitiator compound of formula (I) is described in detail below.

[0068] Example 1

[0069] This embodiment provides a biphenyl derivative photoinitiator, the structural formula of which is shown in A1:

[0070]

[0071] The reaction equation and preparation method of the compound are as follows:

[0072]

[0073] Weigh 4-boric acid triphenylamine (1.15g, 4mmol), bromobenzene (0.30g, 2mmol), tetrakis triphenylphosphine palladium (0.11g, 0.1mmol), potassium carbonate (1.1g, 8mmol) into a 250ml double-necked flask, evacuate and fill with nitrogen, add 20ml tetrahydrofuran solvent and 4ml water, and stir the reaction for 8h at 70℃ under nitrogen protection. After the reaction is completed, cool it to room temperature, extract it with dichloromethane, and separate it with silica gel column chromatography (eluent is petroleum ether: dichloromethane = 6:1).

[0074] Example 2

[0075] This embodiment provides a biphenyl derivative, the structural formula of which is shown in A2:

[0076]

[0077] The reaction equation and preparation method of the compound are as follows:

[0078]

[0079] Weigh 4-bromotriphenylamine (648 mg, 2 mmol), p-fluorophenylboric acid (601 mg, 4 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), and potassium carbonate (1.1 g, 8 mmol) into a 250 ml double-necked flask, evacuate and fill with nitrogen, add 20 ml of tetrahydrofuran solvent and 4 ml of water, and stir and react for 8 hours at a reaction temperature of 70°C under nitrogen protection. After the reaction is completed, cool it to room temperature, extract it with dichloromethane, and separate it by silica gel column chromatography (eluent is petroleum ether: dichloromethane = 5:1).

[0080] Performance Testing

[0081] The biphenyl derivative photoinitiators A1 and A2 obtained in Examples 1 and 2 were characterized and their performance tested.

[0082] The test method is as follows:

[0083] Compound structure detection: using a Bruker 400MHz superconducting nuclear magnetic resonance spectrometer, the solvent is deuterated chloroform or deuterated dichloromethane;

[0084] Mass spectrometry detection: A1, A2, and A3 prepared in Example 1, Example 2, and Example 3 were dissolved in dichloromethane to prepare a solution with a concentration of 1 mg / mL, and mass spectrometry was performed using a liquid spectrometer LCMS-2020.

[0085] UV absorption spectrum detection: Shimadzu UV-visible spectrophotometer UV-2700 was used with a scanning range of 200 to 450 nm;

[0086] Emission spectrum detection: using a steady-state / transient fluorescence spectrometer (FLS980), with an excitation wavelength of 310 nm,

[0087] The test temperature was 300K under nitrogen protection.

[0088] The test results are as follows:

[0089] The product prepared in Example 1 was subjected to nuclear magnetic resonance detection. The structural formula was determined using a Bruker 400 MHz superconducting nuclear magnetic resonance instrument with deuterated chloroform as the solvent. The hydrogen spectrum obtained by the determination was as follows: Figure 1 As shown, the characteristic wave number (ppm) is 1 H NMR (400MHz, Chloroform-d) δ7.55-7.35 (m, 6H), 7.27 (td, J = 7.3, 1.4Hz, 4H), 7.17-7.08 (m, 6H), 7.07-7.01 (m, 2H). It can be seen that the molecular hydrogen spectrum peaks can correspond to the target product one by one, and the quantity is reasonable. This shows that the compound shown in Example 1 of biphenyl bio A1 is prepared, and the compound has a single structure and high purity;

[0090] The product prepared in Example 2 was subjected to nuclear magnetic resonance detection. Specifically, a Bruker 400 MHz superconducting nuclear magnetic resonance instrument was used, and the solvent was deuterated chloroform. The hydrogen spectrum obtained by the measurement was as follows: Figure 2 As shown, the characteristic wave number (ppm) is 1 H NMR (400MHz, Chloroform-d) δ7.53-7.48 (m, 1H), 7.43-7.39 (m, 1H), 7.29-7.24 (m, 2H), 7.14-7.00 (m, 5H). It can be seen that the molecular hydrogen spectrum peaks can correspond to the target product one by one, and the quantity is reasonable. This shows that the compound shown in Example 2 of biphenyl bio A2 is prepared, and the compound has a single structure and high purity.

[0091] Figure 3 This is a diagram of the polymerization degree of DMA monomer initiated by the biphenyl derivative A1 prepared in Example 1 of the present application. Figure 3 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 an increase first and then tended to equilibrium, and as the irradiation time of the ultraviolet LED increased, the viscosity of the sample gradually increased. The content of the photoinitiator was finally selected to be 0.2wt%, and its conversion rate could reach 71%.

[0092] Figure 4 This is a diagram of the polymerization degree of DMA monomer initiated by the biphenyl derivative A2 prepared in Example 2 of the present application. Figure 4 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 an increase first and then tended to equilibrium, and as the irradiation time of the ultraviolet LED increased, the viscosity of the sample gradually increased. The final photoinitiator content was selected to be 0.2wt%, and its conversion rate could reach 95%.

[0093] Table 1: Calculated conversion rate of DMA in A1 / Iod or A2 / Iod system under LED@365nm irradiation

[0094]

[0095] Figure 5 This is a diagram of the polymerization mechanism of DMA monomer initiated by the photoinitiator biphenyl derivative A1 prepared in Example 1 of the present application. Figure 5It can be seen that the photoinitiator generates active species after being excited by light, and the active species attacks the olefin double bonds in the monomer to initiate its chain polymerization and finally generate PDMA polymer.

[0096] Figure 6 The photocurable film of this application is used in the field of anti-counterfeiting. Figure 6 It can be seen that the PDMA photocured film generated after the monomer is polymerized has the characteristics of long afterglow emission. The film generates a school logo pattern under laser etching, and has afterglow emission after illumination.

[0097] Figure 7 Schematic diagram of the polymerization of monomers initiated by initiators. Figure 7 It can be seen that in the absence of light, the initiator molecules are dispersed in the monomers. After the system is irradiated with ultraviolet light, the initiator absorbs energy to generate active species, causing the monomers to undergo chain polymerization, ultimately generating polymers.

[0098] The present application provides a biphenyl derivative photoinitiator having a molecular structure as shown in the following formula (I):

[0099]

[0100] Wherein, R1 is an electron donor group, and R1 is selected from any one of the following groups:

[0101]

[0102] Wherein, R2 is an electron acceptor group, and R2 is selected from any one of the following groups:

[0103]

[0104] The present application also provides a photocurable film material, comprising a photoinitiator and an olefin monomer, wherein the olefin monomer is N,N-dimethylacrylamide, and the photoinitiator is the above-mentioned biphenyl derivative.

[0105] In summary, the present invention connects different electron donor groups R1 and electron acceptor R2 to biphenyl, and synthesizes biphenyl derivatives through Suzuki reaction. The donor and acceptor of the biphenyl derivative form a DA structure, which can effectively reduce the singlet-triplet energy level difference (ΔE ST ), thereby promoting self-selected orbital coupling, thereby generating more triplet excitons. The synthesis of biphenyl derivatives by Suzuki reaction has simple synthesis steps and high yield, and the monomer material DMA is an easily available and cheap industrial production monomer, and the polymerized polymer has good physical properties.

[0106] The biphenyl derivative in the present application has a structural formula as shown in formula (I), R1 is an electron donor group, and R2 is an electron acceptor group. The present application uses biphenyl as the main structure, connects different donor groups R1 and acceptor groups R2, and synthesizes a photoinitiator through Suzuki reaction, and the polymerization monomer material is N,N-dimethylacrylamide (DMA). A photocurable material with long afterglow luminescence can be obtained by ultraviolet irradiation. Under the irradiation of a 365nm ultraviolet lamp, the initiator absorbs photons to generate active species that attack the double bonds in the monomer to initiate a polymerization reaction. The photocurable film can produce long afterglow luminescence for several seconds after irradiation, and can be used in anti-counterfeiting, 3D printing, lithography and other aspects.

[0107] At the same time, the present application realizes the controllable preparation of biphenyl derivative photoinitiators; the preparation cost is low, the raw material sources are wide, large-scale production can be achieved, and it has broad commercial prospects.

[0108] 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.

[0109] 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 biphenyl derivative photoinitiator, characterized in that: The biphenyl derivative photoinitiator has a molecular structure as shown in the following formula (I): Wherein, R1 is an electron donor group, and R1 is selected from any one of the following groups: Wherein, R2 is an electron acceptor group, and R2 is selected from any one of the following groups: -CN -CF3 -NO2 -SO3H -CHO -COOH -COR -F.

2. The biphenyl derivative photoinitiator according to claim 1, characterized in that: The biphenyl derivative photoinitiator is selected from any one of the following structural formulas:

3. The method for preparing the biphenyl derivative photoinitiator according to claim 1, characterized in that: The following steps are involved: Under the protection of inert gas, 4-biphenylboric acid, R-Br, tetrakistriphenylphosphine palladium, potassium carbonate aqueous solution and tetrahydrofuran mixed solvent are reacted together at 50-70° C. for 5-10 hours to obtain a biphenyl derivative having a structure shown in formula (I).

4. A photocurable film material, characterized in that: It comprises a photoinitiator and an olefin monomer, wherein the olefin monomer is N,N-dimethylacrylamide, and the photoinitiator is the biphenyl derivative as claimed in claim 1 or 2.

5. The photocurable film material according to claim 4, characterized in that: The doping mass fraction of the photoinitiator material in the monomer material is 0.2%.

6. The method for preparing the photocurable film material according to claim 4, characterized in that: The following steps are involved: S1. Weigh the photoinitiator material into a clean and dry container, add the monomer until it is completely dissolved to prepare a solution before light curing; S2. The mass fraction of the photoinitiator material doped in the monomer material is 0.2%, and the formula solution is evenly applied on a glass slide, and then the formula solution is cured by irradiating the photocurable film material with an ultraviolet lamp for 120 seconds to obtain a photocurable film.

7. The method for preparing a photocurable thin film material according to claim 6, characterized in that: The monomer in step S1 is N,N-dimethylacrylamide.

8. The method for preparing a photocurable thin film material according to claim 6, characterized in that: In the step S2, the initiator is dissolved in the poly (N,N-dimethylacrylamide) solution, and the initiator sample is completely dissolved by ultrasound.

9. The method for preparing a light-curable thin film material according to claim 6, characterized in that: The wavelength of the ultraviolet lamp is 365nm and the power is 10mW / cm 2 .

10. Application of the photocurable film material according to claim 4 in the fields of anti-counterfeiting, 3D printing and photolithography.

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