Photopolymer composition and application thereof

Abstract

The embodiment of the invention provides a photopolymer composition and application thereof, and the photopolymer composition comprises polyacrylate resin with a side chain containing an epoxy group, an acrylate writing monomer containing an aromatic ring structure, a second monomer and a photoinitiator, the second monomer comprises an epoxy monomer containing an aromatic ring structure and / or a vinyl ether monomer containing an aromatic ring structure. A holographic photosensitive film formed by the photopolymer composition can be subjected to high-temperature and high-pressure lamination treatment without macroscopic phase separation, the photopolymer composition can form a grating structure with high diffraction efficiency, high light transmittance and high performance stability, and the photopolymer composition can be used for head-up display equipment to improve the display effect.

Description

TECHNICAL FIELD

[0001] The embodiments of the present application relate to the technical field of photopolymer, in particular to a photopolymer composition and application thereof. BACKGROUND

[0002] At present, holographic photopolymer materials are widely used in optical components such as head-up display (HUD), AR (Augmented Reality) / VR (Virtual Reality) glasses, holographic storage, etc. In order to meet the application requirements, the holographic photopolymer material needs to be able to form a high-performance stable grating structure, resist high-temperature aging, and in the actual application of HUD, the holographic photopolymer material also needs to be able to withstand high-temperature and high-pressure lamination processing without macroscopic phase separation, so as not to affect the display effect. However, the existing holographic photopolymer material is difficult to meet the requirements of high-performance stability and resistance to high-temperature and high-pressure lamination processing at the same time, thus limiting its application in the field of HUD. SUMMARY

[0003] In view of this, the embodiments of the present application provide a photopolymer composition and application thereof, the holographic photosensitive film formed by the photopolymer composition can withstand high-temperature and high-pressure lamination processing without macroscopic phase separation, the photopolymer composition can form a grating structure with high diffraction efficiency, high light transmittance and high-performance stability, and the photopolymer composition used in head-up display equipment can improve the display effect.

[0004] The first aspect of the embodiments of the present application provides a photopolymer composition, the photopolymer composition comprises a main component, the main component comprises a side chain epoxy group-containing polyacrylate resin, an aromatic ring structure-containing acrylate writing monomer, a second monomer and a photoinitiator, the second monomer comprises an aromatic ring structure-containing epoxy monomer and / or an aromatic ring structure-containing vinyl ether monomer.

[0005] The light polymer composition provided by the embodiment of the present application adopts a polyacrylate resin as a film-forming resin, that is, as a film layer substrate, which is beneficial to improving the mechanical properties, optical properties and thermal stability of the film layer structure of the light polymer composition; adopts an acrylic resin containing an aromatic ring structure as a writing monomer, which has a high refractive index and can form a grating structure by regionally polymerizing under the action of exposure, improving the performance of the grating structure; the second monomer containing an aromatic ring structure is introduced into the light polymer composition system, which can play a dilution role, improve the diffusion capacity of the writing monomer, make the writing monomer more fully polymerize in the coherent bright area, form a grating structure with a larger refractive index difference, thereby improving the diffraction efficiency of the grating, and also can make the entire film layer form a three-dimensional network structure with more stable structure, reduce the volume shrinkage of the film layer structure, and improve the structural stability of the film layer; and the second monomer and the writing monomer both contain an aromatic ring structure, which can reduce the solubility parameter difference between the two, make the compatibility of the entire system better, thereby effectively avoiding the occurrence of macroscopic phase separation in the high-temperature and high-pressure film clamping and pressing process, and being beneficial to the application of the light polymer composition in the HUD field.

[0006] In the embodiment of the present application, the epoxy monomer containing an aromatic ring structure includes one or more of a monofunctional or polyfunctional glycidyl ether containing an aromatic ring structure, a monofunctional or polyfunctional oxetane containing an aromatic ring structure, and a monofunctional or polyfunctional alicyclic epoxy monomer containing an aromatic ring structure; the vinyl ether monomer containing an aromatic ring structure includes a monofunctional or polyfunctional vinyl ether monomer containing an aromatic ring structure. The epoxy monomer containing an aromatic ring structure and the vinyl ether monomer containing an aromatic ring structure can undergo cationic polymerization under the action of a cationic photoinitiator, form a three-dimensional network structure with the polyacrylate resin, improve the structural stability of the entire film layer, and thereby improve the stability of the holographic grating.

[0007] In the embodiment of the present application, the aromatic ring structure includes an aromatic ring structure and / or an aromatic heterocyclic ring structure, and the aromatic ring structure includes one or more of a substituted or unsubstituted benzene ring structure, a substituted or unsubstituted biphenyl structure, a substituted or unsubstituted naphthalene ring structure, a substituted or unsubstituted anthracene ring structure, a substituted or unsubstituted fluorene ring structure, a substituted or unsubstituted pyrrole structure, and a substituted or unsubstituted benzopyrrole structure. The epoxy monomer containing the above aromatic ring structure has high compatibility in the composition system, can effectively avoid the occurrence of macroscopic phase separation in the high-temperature and high-pressure film clamping and pressing process, is beneficial to forming a grating structure with a larger refractive index difference, improving the diffraction efficiency, and improving the structural stability of the obtained film layer; and thereby is beneficial to the application of the light polymer composition in the HUD field.

[0008] In the embodiment of the present application, the epoxy monomer containing an aromatic ring structure includes any one or more of the monomers represented by formula (A1) to formula (A25):

[0009]

[0010]

[0011] The epoxy monomer containing aromatic ring structure is added to the photopolymer composition system, which is beneficial to form a grating structure with a large refractive index difference and improve the diffraction efficiency; the epoxy monomer can be crosslinked with the polyacrylate resin under the action of a photoinitiator, thereby improving the structural stability of the obtained film layer; and the epoxy monomer has high compatibility in the composition system, which can effectively avoid macroscopic phase separation in the high-temperature and high-pressure film pressing process, thereby facilitating the application of the photopolymer composition in the HUD field.

[0012] In the embodiments of the present application, the vinyl ether monomer containing an aromatic ring structure includes any one or more of the monomers represented by formula (B1) to formula (B24):

[0013]

[0014]

[0015] The epoxy monomer containing an aromatic ring structure is added to the photopolymer composition system, which is beneficial to form a grating structure with a large refractive index difference and improve the diffraction efficiency; the epoxy monomer can be crosslinked with the polyacrylate resin under the action of a photoinitiator, thereby improving the structural stability of the obtained film layer; and the epoxy monomer has high compatibility in the composition system, which can effectively avoid macroscopic phase separation in the high-temperature and high-pressure film pressing process, thereby facilitating the application of the photopolymer composition in the HUD field.

[0016] In the embodiments of the present application, the solubility parameter difference Δδ of the acrylic ester writing monomer containing an aromatic ring structure and the second monomer is ≤5 (J / cm 3 ) 1 / 2 When the solubility parameter difference of the acrylic ester writing monomer containing an aromatic ring structure and the second monomer is less than 5 (J / cm 3 ) 1 / 2 , it is beneficial to better improve the mutual solubility and avoid phase separation.

[0017] In the main component, the mass percentage of the second monomer is 5% to 40% in the present application. The photopolymer composition of the present application can maintain no macroscopic phase separation in the sandwich film process at a higher addition amount of the second monomer, so as to better utilize the second monomer to improve the thermal stability of the final grating structure and improve the anti-aging performance. Controlling the content of the second monomer in the photopolymer composition in a suitable range is beneficial to better maintain no macroscopic phase separation in the sandwich film process while taking into account high thermal stability.

[0018] In the present application, the aromatic ring structure-containing acrylate writing monomer includes one or more of aromatic ring structure-containing mono- or multi-functional acrylate and aromatic ring structure-containing mono- or multi-functional methacrylate. The presence of the aromatic ring structure is beneficial to improve the refractive index of the writing monomer.

[0019] In the present application, the side chain epoxy group-containing polyacrylate resin includes an acrylate homopolymer and / or an acrylate copolymer. In the present application, the side chain epoxy group-containing acrylate copolymer can be a copolymer of at least one acrylate monomer not containing an epoxy group and at least one acrylate monomer containing an epoxy group. Exemplarily, the acrylate monomer not containing an epoxy group includes at least one of methyl acrylate, methyl methacrylate (MMA), ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, and 2-ethylhexyl methacrylate. The acrylate monomer containing an epoxy group can be at least one of glycidyl methacrylate (GMA), 3,4-epoxycyclohexylmethyl methacrylate (ECMMA), and oxetane methacrylate. In some embodiments, the side chain epoxy group-containing acrylate copolymer includes a copolymer of methyl methacrylate and glycidyl methacrylate (P(MMA-co-GMA)). In the present application, the film-forming resin is a side chain epoxy group-containing polyacrylate resin, so that the aromatic ring structure-containing epoxy monomer can be crosslinked with the polyacrylate resin to form a more stable three-dimensional crosslinked network in the post-processing process.

[0020] In the present application, the photoinitiator includes a visible light radical type photoinitiator capable of initiating a radical polymerization reaction of the aromatic ring structure-containing acrylate writing monomer and a cationic type photoinitiator capable of initiating a cationic polymerization reaction of the second monomer.

[0021] In the main component, the mass percentage of the side chain epoxy group-containing polyacrylate resin is 20% to 50% in the present application.

[0022] and / or, the mass percentage content of the aromatic ring-containing acrylate writing monomer is 20%-50%;

[0023] and / or, the mass percentage content of the photoinitiator is 0.2%-15%. Controlling the content of the polyacrylate resin in the photopolymer composition system at a suitable content is conducive to film formation and ensures the mechanical properties, optical properties and thermal stability of the obtained film layer after subsequent film formation. Controlling the content of the writing monomer in the photopolymer composition system at a suitable content is conducive to the formation of the grating structure.

[0024] In the present application, the mass percentage content of the visible light radical type photoinitiator capable of initiating the radical polymerization of the writing monomer in the photopolymer composition relative to the main component is 0.1%-10%. The addition of a suitable amount of the visible light radical type photoinitiator can better achieve the polymerization of the writing monomer and avoid the negative effects caused by the excessive addition of the photoinitiator.

[0025] In the present application, the mass percentage content of the cationic type photoinitiator capable of initiating the cationic polymerization of the second monomer in the photopolymer composition relative to the main component is 0.1%-5%. The addition of a suitable amount of the cationic type photoinitiator can better achieve the polymerization of the second monomer and avoid the negative effects caused by the excessive addition of the photoinitiator.

[0026] In the present application, the photopolymer composition further comprises a solvent, and the solvent comprises one or more of dimethylformamide, an alcohol solvent and a ketone solvent. The solvent as a medium can disperse the components and form a slurry with suitable fluidity for film formation.

[0027] In the present application, the obtained film material of the photopolymer composition after molding undergoes a pressing treatment at a temperature of 100°C-150°C and a pressure of 5bar-15bar, and has no defects in appearance and does not undergo macroscopic phase separation. The photopolymer composition of the present application can withstand high temperature and high pressure pressing treatment, which is conducive to its application in the field of automobile windshields and the like.

[0028] In the present application, the grating structure layer prepared using the photopolymer composition has an average light transmittance greater than or equal to 80% in the range of 400nm-800nm and a diffraction efficiency greater than 100%. The photopolymer composition of the present application can be used to prepare a holographic optical element with high light transmittance and diffraction efficiency in the visible light region, which can be applied to the field of holographic display to improve the performance of holographic display equipment.

[0029] In the embodiments of the present application, the grating structure layer prepared by using the photopolymer composition has an average light transmittance greater than 75% in the range of 400-800 nm and a diffraction peak drift change less than 5 nm after aging at 85℃ for 1000 hours. The grating structure layer prepared by using the photopolymer composition of the embodiments of the present application has excellent heat aging resistance and stable performance after aging at 85℃ for a long time.

[0030] The second aspect of the embodiments of the present application provides an application of the photopolymer composition of the first aspect in holographic display, holographic storage or anti-counterfeiting identification. Specifically, it can be applied to a head-up display (HUD), AR / VR glasses, a holographic diffusion screen, holographic projection, a holographic memory and the like. Specifically in a vehicle, it can be applied to an instrument panel, a central control screen, a windshield and the like. In an embodiment, it can be applied to the field of vehicle head-up display to prepare an automobile windshield.

[0031] The third aspect of the embodiments of the present application provides a holographic photosensitive film formed by the photopolymer composition of the first aspect of the embodiments of the present application.

[0032] The fourth aspect of the embodiments of the present application provides a preparation method of a holographic photosensitive film, comprising:

[0033] The photopolymer composition of the first aspect of the embodiments of the present application is coated on a substrate, and after drying, a holographic photosensitive film attached to the substrate is obtained.

[0034] The fifth aspect of the embodiments of the present application provides a holographic optical element, comprising the holographic photosensitive film of the third aspect of the embodiments of the present application, or comprising a grating structure layer obtained from the holographic photosensitive film of the third aspect of the embodiments of the present application. The grating structure layer is specifically a resin film layer with a grating structure obtained from the holographic photosensitive film after exposure and post-processing operations.

[0035] In the embodiments of the present application, the holographic optical element further comprises a transparent substrate located on one side or both sides of the holographic photosensitive film or the grating structure layer.

[0036] The embodiments of the present application further provide a display device comprising the holographic optical element of the fifth aspect of the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a schematic diagram of forming a holographic grating structure using an existing holographic photopolymer material;

[0038] Figure 2 is a schematic diagram of forming a holographic grating using the photopolymer composition of the embodiments of the present application;

[0039] Figure 3FIG. 1 is a schematic diagram of a cross-sectional structure of a holographic optical element 100 provided by an embodiment of the present application;

[0040] Figure 4 FIG. 6 is a photograph of a glass film sandwich module of Example 1 of the present application after exposure to sunlight, laser transmission light, and laser light;

[0041] Figure 5 FIG. 7 is an ultraviolet-visible light absorption spectrum of the grating structure layer of Example 1 of the present application;

[0042] Figure 6 FIG. 8 is an ultraviolet-visible light absorption spectrum of the grating structure layer of Example 1 of the present application at different aging times;

[0043] Figure 7 FIG. 12 is a photograph of a glass film sandwich module of Example 2 of the present application after exposure to sunlight, laser transmission light, and laser light;

[0044] Figure 8 FIG. 13 is an ultraviolet-visible light absorption spectrum of the grating structure layer of Example 2 of the present application;

[0045] Figure 9 FIG. 14 is an ultraviolet-visible light absorption spectrum of the grating structure layer of Example 2 of the present application at different aging times;

[0046] Figure 10 FIG. 18 is a photograph of a glass film sandwich module of Example 3 of the present application after exposure to sunlight, laser transmission light, and laser light;

[0047] Figure 11 FIG. 19 is an ultraviolet-visible light absorption spectrum of the grating structure layer of Example 3 of the present application;

[0048] Figure 12 FIG. 20 is an ultraviolet-visible light absorption spectrum of the grating structure layer of Example 3 of the present application at different aging times;

[0049] Figure 13 FIG. 24 is a photograph of a glass film sandwich module of Comparative Example 1 of the present application after exposure to sunlight, laser transmission light, and laser light;

[0050] Figure 14 FIG. 25 is a comparison of ultraviolet-visible light absorption spectra of the grating structure layers of Example 1 and Comparative Example 1 of the present application;

[0051] Figure 15 FIG. 28 is a photograph of a glass film sandwich module of Comparative Example 2 of the present application after exposure to sunlight, laser transmission light, and laser light;

[0052] Figure 16 FIG. 29 is a comparison of ultraviolet-visible light absorption spectra of the grating structure layers of Example 1 and Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0053] The embodiments of the present application will be described below with reference to the accompanying drawings of the embodiments of the present application.

[0054] Holographic technology is a technology that records and reproduces all optical information of an object using interference and diffraction principles. The implementation of holographic technology includes forming a holographic grating structure using a holographic photopolymer material, which mainly consists of a film-forming resin, a writing monomer and a photoinitiator. Referring to Figure 1 The process of forming a holographic grating structure using a holographic photopolymer material specifically includes: under the irradiation of two coherent lasers, the photoinitiator initiates the polymerization reaction (usually free radical polymerization) of the writing monomer in the coherent bright area, and the chemical potential difference caused by the concentration of the writing monomer makes the writing monomer in the coherent dark area diffuse to the coherent bright area and participate in the photopolymerization reaction, finally resulting in different polymer densities and refractive indices in the coherent bright area and the coherent dark area, forming a grating structure with periodic distribution of refractive index, and realizing holographic information recording.

[0055] At present, holographic photopolymer materials are widely used in optical components such as head-up display devices, AR / VR glasses, holographic diffusion screens, holographic storage, etc. In order to meet the application requirements of these fields, the holographic photopolymer material needs to be able to form a grating with high performance stability (including performance stability under different environmental conditions and long-term use), resist high-temperature aging, and in the actual application of HUD, the holographic photopolymer material needs to be able to withstand high-temperature and high-pressure pressing process without macroscopic phase separation in appearance. This is mainly because, in the actual application of HUD, the holographic photopolymer material film needs to be sandwiched between two layers of automotive laminated glass, and after a series of harsh processes such as high temperature and high pressure, a film sandwich module is formed, and then a grating structure is formed by laser exposure; and in this process, the holographic photopolymer material is prone to macroscopic phase separation due to the enrichment of components caused by system compatibility and stress, resulting in appearance defects of the film sandwich module and subsequent non-uniformity of exposure, thereby affecting the display effect. However, the existing holographic photopolymer material is difficult to meet the requirements of high performance stability and resistance to high-temperature and high-pressure pressing process at the same time, thus limiting its application in the field of HUD. In view of this, the embodiments of the present application provide a photopolymer composition, which can form a holographic photosensitive film through molding, and the holographic photosensitive film can form a holographic grating with high performance stability after exposure treatment, and the holographic photosensitive film can withstand high-temperature and high-pressure pressing process without macroscopic phase separation, so as to meet the application requirements of HUD.

[0056] The embodiments of the present application provide a photopolymer composition, which comprises a main component, and the main component comprises a polyacrylate resin containing an epoxy group in a side chain, an acrylic ester writing monomer containing an aromatic ring structure, a second monomer and a photoinitiator, wherein the second monomer comprises an epoxy monomer containing an aromatic ring structure and / or a vinyl ether monomer containing an aromatic ring structure.

[0057] The light polymer composition provided by the embodiment of the present application uses a polyacrylate resin as a film-forming resin, i.e., as a film layer substrate, which is beneficial to improving the mechanical properties, optical properties and thermal stability of the film layer structure of the light polymer composition; uses an acrylic resin containing an aromatic ring structure as a writing monomer, which has a high refractive index and can form a grating structure by regional polymerization under the action of exposure, thereby improving the performance of the grating structure; the second monomer containing an aromatic ring structure is introduced into the light polymer composition system, which can play a dilution role, improve the diffusion ability of the writing monomer, make the writing monomer more fully polymerize in the coherent bright area, form a grating structure with a larger refractive index difference, thereby improving the diffraction efficiency of the grating, and also make the entire film layer form a three-dimensional network structure with better stability, reduce the volume shrinkage of the film layer structure, and improve the structural stability of the film layer; moreover, the second monomer and the writing monomer both contain an aromatic ring structure, which can reduce the solubility parameter difference between the two, make the compatibility of the entire system better, thereby effectively avoiding the occurrence of macroscopic phase separation in the high-temperature and high-pressure film pressing process, and being beneficial to the application of the light polymer composition in the HUD field.

[0058] Referring to Figure 2 , Figure 2 is a schematic diagram of forming a holographic grating using the light polymer composition of the embodiment of the present application. As shown in Figure 2 , the process of forming a holographic grating structure using the light polymer composition of the embodiment of the present application specifically includes: under the irradiation and exposure of two coherent lasers, the photoinitiator initiates a free radical polymerization reaction of the writing monomer in the coherent bright area, the chemical potential difference caused by the concentration of the writing monomer makes the writing monomer in the coherent dark area diffuse to the coherent bright area and participate in the photopolymerization reaction, resulting in different polymer densities and refractive indexes of the coherent bright area and the coherent dark area, and forming a grating structure with a periodic distribution of refractive index; in the subsequent post-processing process, the second monomer undergoes a cationic polymerization reaction under the action of the photoinitiator, forming a three-dimensional network structure of the second monomer derived segment and the polyacrylate resin containing an epoxy group in the side chain, thereby improving the structural stability of the entire film layer and the thermal stability of the holographic grating.

[0059] It can be understood that in the embodiments of the present application, the photoinitiator includes a visible light radical type photoinitiator capable of initiating radical polymerization of the writing monomer, and a cationic type photoinitiator capable of initiating cationic polymerization of the second monomer. Among them, the cationic type photoinitiator can be a visible light cationic type photoinitiator, or an ultraviolet light cationic type photoinitiator. Visible light photoinitiator is a kind of compound with the ability to absorb visible light (400nm-800nm), which can absorb energy of a certain wavelength in the visible light region to produce free radicals, cations and other substances, thereby initiating monomer polymerization and crosslinking curing. The cationic photoinitiator is a compound that can be activated by light to reach the excited state, undergo a series of decomposition reactions, and finally produce a super strong proton acid (also known as Bronsted acid), which is the active species of cationic polymerization to initiate polymerization of epoxy monomer and vinyl ether monomer.

[0060] In the embodiments of the present application, the visible light radical type photoinitiator can be various known visible light radical type photoinitiators, for example, but not limited to, benzoin and its derivatives, benzoin ethers, imidazoles, titanium metallocenes, alkyl phenone, acyl phosphine oxide, coumarin ketone, thioxanthone, dyes. More specifically, the visible light radical type photoinitiator can be one or more of bis(2,4,5-triphenyl)imidazole, fluorinated diphenyl titanium metallocene (Irgacure 784), bis(pentafluorophenyl) titanium metallocene, 2-hydroxy-2-methyl-1-phenylpropanone, 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, neomethylene blue, toluidine blue, azure A, safranin O, rose Bengal, basic orange, 3,3'-carbonyl bis(7-diethylamine coumarin), basic red 2, cyanine, basic yellow, 2-isopropyl thioxanthone, etc.

[0061] In the embodiments of the present application, the cationic type photoinitiator can be various known cationic type photoinitiators, for example, but not limited to, one or more of diazonium salt, onium salt, metal organic compound, organosilane, sulfonyloxy ketone and triaryl siloxane ether. Among them, the onium salt can be, for example, diaryl iodonium salt, triaryl sulfonium salt, alkyl sulfonium salt. The metal organic compound can be, for example, iron arene salt.

[0062] During the formation of the grating, as the writing monomer gradually polymerizes in the bright area to increase the viscosity of the system, it is difficult for the writing monomer in the dark area to continue to diffuse to the bright area to continue to polymerize, and the second monomer can play a dilution role to reduce the viscosity of the system, so that the writing monomer can continue to diffuse and polymerize to form a grating structure with greater refractive index difference, thereby improving the diffraction efficiency of the grating.

[0063] In some embodiments of the present application, the second monomer can be an epoxy monomer comprising only a structure containing an aromatic ring; in some other embodiments of the present application, the second monomer can be a vinyl ether monomer comprising only a structure containing an aromatic ring; in some other embodiments of the present application, the second monomer comprises both an epoxy monomer comprising a structure containing an aromatic ring and a vinyl ether monomer comprising a structure containing an aromatic ring. The epoxy monomer comprising a structure containing an aromatic ring and the vinyl ether monomer comprising a structure containing an aromatic ring can undergo cationic polymerization under the action of a cationic photoinitiator in a post-processing process, forming a three-dimensional network structure, improving the structural stability of the entire film layer, and thus improving the thermal stability of the holographic grating. In addition, based on the principle of similar compatibility, the introduction of the epoxy monomer comprising a structure containing an aromatic ring and the vinyl ether monomer comprising a structure containing an aromatic ring can improve the compatibility of the composition system, and better avoid the occurrence of macroscopic phase separation in the film clamping and pressing process.

[0064] In embodiments of the present application, the epoxy monomer comprising a structure containing an aromatic ring can be one or more of a monofunctional or polyfunctional glycidyl ether comprising a structure containing an aromatic ring, a monofunctional or polyfunctional oxetane comprising a structure containing an aromatic ring, and a monofunctional or polyfunctional alicyclic epoxy monomer comprising a structure containing an aromatic ring. In embodiments of the present application, the vinyl ether monomer comprising a structure containing an aromatic ring can be a monofunctional or polyfunctional vinyl ether monomer comprising a structure containing an aromatic ring. In the present application, "monofunctional" refers to a monofunctional group, and "polyfunctional" refers to a polyfunctional group.

[0065] In embodiments of the present application, the structure containing an aromatic ring includes an aromatic ring structure and / or an aromatic heterocyclic ring structure. That is, the epoxy monomer comprising a structure containing an aromatic ring and the vinyl ether monomer comprising a structure containing an aromatic ring can contain only an aromatic ring structure, can contain only an aromatic heterocyclic ring structure, or can contain both an aromatic ring structure and an aromatic heterocyclic ring structure.

[0066] In some embodiments, the structure containing an aromatic ring includes one or more of a substituted or unsubstituted benzene ring structure, a substituted or unsubstituted biphenyl structure, a substituted or unsubstituted naphthalene ring structure, a substituted or unsubstituted anthracene ring structure, a substituted or unsubstituted fluorene ring structure, a substituted or unsubstituted pyrrole structure, and a substituted or unsubstituted benzopyrrole structure. The epoxy monomer comprising a structure containing an aromatic ring and the vinyl ether monomer comprising a structure containing an aromatic ring can contain one or more of the above-mentioned aromatic ring structures. In some embodiments, the epoxy monomer comprising a structure containing an aromatic ring and the vinyl ether monomer comprising a structure containing an aromatic ring contain two or more substituted or unsubstituted benzene ring structures, and the two or more substituted or unsubstituted benzene ring structures are connected by a bridging group, which can be a substituted or unsubstituted alkylene group (such as methylene, ethylene, propylene, isopropylene), a substituted or unsubstituted alkylidene group (such as methylidene, ethylidene, propylidene, isopropylidene), or a substituted or unsubstituted cycloalkylene group (such as cyclohexylene). The substituted or unsubstituted biphenyl structure can be a substituted or unsubstituted bi-biphenyl structure or a substituted or unsubstituted tri-biphenyl structure.

[0067] In the embodiments of the present application, the substituent groups in the substituted benzene ring structure, the substituted biphenyl structure, the substituted naphthalene ring structure, the substituted anthracene ring structure, the substituted fluorene ring structure, the substituted pyrrole structure, and the substituted benzopyrrole structure can be alkyl, alkoxy, epoxy, aryl, etc. The alkyl can be an alkyl group having 1-6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc. The alkoxy can be an alkoxy group having 1-6 carbon atoms, such as methoxy, ethoxy, etc. The epoxy can be, but is not limited to, an epoxy ethyl group or an epoxy propyl group.

[0068] In some embodiments of the present application, the epoxy monomer containing an aromatic ring structure can be any one or more of the monomers represented by formula (A1) to formula (A25):

[0069]

[0070]

[0071] The epoxy monomer containing an aromatic ring structure described above is added to the photopolymer composition system, which is beneficial to form a grating structure with a large refractive index difference, thereby improving the diffraction efficiency. The epoxy monomer described above can crosslink with the polyacrylate resin under the action of a photoinitiator, thereby improving the structural stability of the obtained film layer. Moreover, the epoxy monomer described above has high compatibility in the composition system, which can effectively avoid the occurrence of macroscopic phase separation during the high-temperature and high-pressure film pressing process, thereby being beneficial to the application of the photopolymer composition in the field of HUD.

[0072] In some embodiments of the present application, the vinyl ether monomer containing an aromatic ring structure can be any one or more of the monomers represented by formula (B1) to formula (B24):

[0073]

[0074]

[0075] The vinyl ether monomer containing an aromatic ring structure described above is added to the photopolymer composition system, which is beneficial to form a grating structure with a large refractive index difference, thereby improving the diffraction efficiency. The vinyl ether monomer described above can undergo cationic polymerization under the action of a photoinitiator, and together with the polyacrylate resin, form a more stable network structure, thereby improving the structural stability of the obtained film layer. Moreover, the vinyl ether monomer described above has high compatibility in the composition system, which can effectively avoid the occurrence of macroscopic phase separation during the high-temperature and high-pressure film pressing process, thereby being beneficial to the application of the photopolymer composition in the field of HUD.

[0076] In some embodiments, the difference between the solubility parameters of the aromatic ring-containing acrylate writing monomer and the second monomer is less than or equal to 5 (J / cm 3 ) 1 / 2 . The difference between the solubility parameters of the aromatic ring-containing acrylate writing monomer and the second monomer is less than or equal to 5 (J / cm 3 ) 1 / 2 . In some embodiments, the difference between the solubility parameters of the aromatic ring-containing acrylate writing monomer and the second monomer is 1 (J / cm 3 ) 1 / 2 , 2 (J / cm 3 ) 1 / 2 , 3 (J / cm 3 ) 1 / 2 , 4 (J / cm 3 ) 1 / 2 , 5 (J / cm 3 ) 1 / 2 . The solubility parameter of a substance (J / cm 3 ) 1 / 2 The solubility parameter is calculated by the group contribution method, which can be used to preliminarily evaluate the mutual solubility of different components. In the present application, the solubility parameter is the Dutch-Finsterla solubility parameter. The Dutch-Finsterla solubility parameter is proposed by J.H. Van Krevelen and P.J. Hoftyzer. The basic calculation formula of the Dutch-Finsterla solubility parameter is as follows: δ = (ρ∑Fi) / M, where δ is the solubility parameter; Fi is the molar attraction constant of each group component in the molecule (which can be obtained by consulting literature); ρ and M are the molecular density and molecular weight, respectively.

[0077] In some embodiments, the mass percentage of the second monomer in the main component can be 5%-40%, i.e., the mass ratio of the second monomer to the main component is 5%-40%. The photopolymer composition of the present application can maintain no macroscopic phase separation in the interlayer process at a higher addition amount of the second monomer, so as to better utilize the second monomer to improve the thermal stability of the final grating structure and improve its anti-aging performance. Controlling the content of the second monomer in the photopolymer composition in a suitable range is beneficial to better maintain high thermal stability while avoiding macroscopic phase separation in the interlayer process. In some embodiments, the mass percentage of the second monomer in the main component can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 40%.

[0078] In the present application, the acrylic ester writing monomer containing aromatic ring structure can be distributed and polymerized in a region during the exposure process to form a grating structure. The region where the acrylic ester writing monomer containing aromatic ring structure is more aggregated corresponds to the formation of Figure 2 the coherent bright region shown in the figure, and the region where the acrylic ester writing monomer containing aromatic ring structure is less aggregated corresponds to the formation of Figure 2 the coherent dark region shown in the figure. In the embodiments of the present application, the acrylic ester writing monomer containing aromatic ring structure can be one or more of a single or multi-functional acrylic ester containing aromatic ring structure, a single or multi-functional methacrylic ester containing aromatic ring structure. In the photopolymer composition, one or more acrylic ester writing monomers containing aromatic ring structure can be contained.

[0079] In the present application, the acrylic ester writing monomer containing aromatic ring structure can be one or more of a single or multi-functional acrylic ester containing aromatic ring structure, a single or multi-functional methacrylic ester containing aromatic ring structure. In the photopolymer composition, one or more acrylic ester writing monomers containing aromatic ring structure can be contained.

[0080] The acrylic ester writing monomer containing aromatic ring structure can contain one or more of the above-mentioned aromatic ring structures. The presence of aromatic ring structure is beneficial to improve the refractive index of the writing monomer. In some embodiments, the acrylic ester writing monomer containing aromatic ring structure contains two or more substituted or unsubstituted benzene ring structures, and the two or more substituted or unsubstituted benzene ring structures are connected by a bridging group, which can be a substituted or unsubstituted alkylene group (such as methylene, ethylene, propylene, isopropylene), a substituted or unsubstituted alkylidene group (such as methylidene, ethylidene, propylidene, isopropylidene), a substituted or unsubstituted cycloalkylene group (such as cyclohexylene).

[0081] In some embodiments, the acrylic ester writing monomer containing aromatic ring structure can be one or more of the following monomer compounds:

[0082] 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene,

[0083] o-phenylphenoxyethyl acrylate, 2-naphthalene thioethyl acrylate,

[0084] 2-(9H-carbazole-9-yl)acrylate.

[0085] In some embodiments of the present application, the refractive index of the aromatic ring structure-containing acrylate writing monomer is greater than the refractive index of the polyacrylate resin and the second monomer. The aromatic ring structure-containing acrylate writing monomer is a high-refractive-index component, and the polyacrylate resin and the second monomer are low-refractive-index components. This can better form a refractive index difference when forming the grating structure.

[0086] The side chain epoxy group-containing polyacrylate resin as the film-forming resin is used as a base resin for forming the holographic photosensitive film and provides mechanical support for the entire holographic photosensitive film. The polyacrylate resin has good mechanical properties, optical properties, and thermal stability, which is conducive to improving the optical properties, stability, and service life of the obtained holographic grating. The side chain epoxy group-containing polyacrylate resin can be an acrylate homopolymer and / or an acrylate copolymer. In some embodiments, the side chain epoxy group-containing polyacrylate resin only includes an acrylate homopolymer; in some embodiments, the side chain epoxy group-containing polyacrylate resin only includes an acrylate copolymer; and in some embodiments, the side chain epoxy group-containing polyacrylate resin includes both an acrylate homopolymer and an acrylate copolymer.

[0087] The side chain epoxy group-containing acrylate copolymer can be a copolymer of at least one acrylate monomer not containing an epoxy group and at least one acrylate monomer containing an epoxy group. Exemplarily, the acrylate monomer not containing an epoxy group includes at least one of methyl acrylate, methyl methacrylate (MMA), ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, amyl methacrylate, and 2-ethylhexyl methacrylate. The acrylate monomer containing an epoxy group can be at least one of glycidyl methacrylate (GMA), 3,4-epoxycyclohexylmethyl methacrylate (ECMMA), and oxetane methacrylate. In some embodiments, the side chain epoxy group-containing acrylate copolymer includes a copolymer of methyl methacrylate and glycidyl methacrylate (P(MMA-co-GMA)). In the present application, the film-forming resin is the side chain epoxy group-containing polyacrylate resin, so that, in the post-processing process, the epoxy monomer containing an aromatic ring structure can be crosslinked with the polyacrylate resin to form a more stable three-dimensional crosslinked network.

[0088] In the embodiments of the present application, the weight average molecular weight Mw of the side chain epoxy group-containing polyacrylate resin is 20,000-500,000. In some embodiments, the weight average molecular weight Mw of the side chain epoxy group-containing polyacrylate resin is 20,000, 50,000, 100,000, 120,000, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, or 500,000.

[0089] In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the main component is 20% to 50%. That is, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component is 20% to 50%. Controlling the content of the polyacrylate resin in the photopolymer composition system to a suitable content is conducive to film formation and ensures the mechanical properties, optical properties, and thermal stability of the film obtained after subsequent film formation. In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component can be, but is not limited to, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0090] In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the main component is 20% to 50%. That is, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component is 20% to 50%. Controlling the content of the polyacrylate resin in the photopolymer composition system to a suitable content is conducive to film formation and ensures the mechanical properties, optical properties, and thermal stability of the film obtained after subsequent film formation. In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component can be, but is not limited to, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0091] In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the main component is 20% to 50%. That is, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component is 20% to 50%. Controlling the content of the polyacrylate resin in the photopolymer composition system to a suitable content is conducive to film formation and ensures the mechanical properties, optical properties, and thermal stability of the film obtained after subsequent film formation. In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component can be, but is not limited to, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0092] In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the main component is 20% to 50%. That is, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component is 20% to 50%. Controlling the content of the polyacrylate resin in the photopolymer composition system to a suitable content is conducive to film formation and ensures the mechanical properties, optical properties, and thermal stability of the film obtained after subsequent film formation. In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component can be, but is not limited to, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0093] In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the main component is 20% to 50%. That is, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component is 20% to 50%. Controlling the content of the polyacrylate resin in the photopolymer composition system to a suitable content is conducive to film formation and ensures the mechanical properties, optical properties, and thermal stability of the film obtained after subsequent film formation. In some embodiments, the mass percentage of the polyacrylate resin with an epoxy group in the side chain in the photopolymer composition relative to the main component can be, but is not limited to, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0094] In the embodiments of the present application, the photopolymer composition further comprises a solvent, which can disperse the components and form a slurry with suitable fluidity as a medium for film formation, and the solvent can be one or more of dimethylformamide, alcohol solvent, ketone solvent. The alcohol solvent can be, for example, methanol, etc. The ketone solvent can be, for example, acetone, etc. The amount of the solvent can be reasonably adjusted according to the actual situation.

[0095] The photopolymer composition of the present application can be obtained by uniformly mixing and stirring the components. The components in the photopolymer composition can be analyzed and characterized by infrared spectroscopy, chromatography, chromatography-mass spectrometry, etc.

[0096] In the embodiments of the present application, the film material (i.e., holographic photosensitive film) obtained after the photopolymer composition is shaped is subjected to a pressing treatment at a temperature of 100-150°C and a pressure of 5-15 bar, and has no defects in appearance and no macroscopic phase separation. Macroscopic phase separation refers to phase separation on a macroscopic scale, which has visible defects to the naked eye, and is specifically manifested in uneven distribution of film layer components, uneven thickness of film layer, and slurry-rich areas in the film layer. The photopolymer composition of the present application can withstand high-temperature and high-pressure pressing treatment, which is beneficial to its application in the field of automotive windshields, etc.

[0097] In the embodiments of the present application, the grating structure layer prepared from the photopolymer composition described above has an average transmittance greater than or equal to 80% in the range of 400-800 nm of visible light and a diffraction efficiency greater than 100%. In some embodiments, the diffraction efficiency is greater than 110%. In some embodiments, the diffraction efficiency is greater than 120%. In some embodiments, the diffraction efficiency is greater than 130%. The photopolymer composition of the present application can be used to prepare a holographic optical element with high transmittance and diffraction efficiency in the visible light region, which can be applied to the field of holographic display to improve the performance of holographic display devices. The transmittance is the ratio of the light intensity transmitted through the sample to the incident light intensity, and the average transmittance can be obtained by a haze meter. The diffraction efficiency is the ratio of the light intensity in a certain diffraction direction to the incident light intensity, which can be calculated according to the ultraviolet-visible absorption spectrum.

[0098] In the embodiments of the present application, the grating structure layer prepared from the photopolymer composition described above has an average transmittance greater than or equal to 80% in the range of 400-800 nm of visible light and a diffraction efficiency greater than 100%. In some embodiments, the diffraction efficiency is greater than 110%. In some embodiments, the diffraction efficiency is greater than 120%. In some embodiments, the diffraction efficiency is greater than 130%. The photopolymer composition of the present application can be used to prepare a holographic optical element with high transmittance and diffraction efficiency in the visible light region, which can be applied to the field of holographic display to improve the performance of holographic display devices. The transmittance is the ratio of the light intensity transmitted through the sample to the incident light intensity, and the average transmittance can be obtained by a haze meter. The diffraction efficiency is the ratio of the light intensity in a certain diffraction direction to the incident light intensity, which can be calculated according to the ultraviolet-visible absorption spectrum.

[0099] The holographic photosensitive film is formed by the photopolymer composition according to the embodiment of the present application. The holographic photosensitive film can be formed into a thin film material, and can form a required grating structure through subsequent exposure and post-processing operations.

[0100] The thickness of the holographic photosensitive film can be designed as required. In order to better form a grating structure with good performance under exposure conditions, and to avoid application limitations caused by excessive thickness, the thickness of the holographic photosensitive film can be controlled to be 5 μm-50 μm. For example, the thickness of the holographic photosensitive film can be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm.

[0101] The preparation method of the holographic photosensitive film according to the embodiment of the present application can include the following steps:

[0102] The photopolymer composition according to the embodiment of the present application is coated on a substrate in a light-free environment, and a holographic photosensitive film attached to the substrate is obtained after drying.

[0103] The substrate can be selected from glass, polymer materials, and the like. The drying temperature can be 60-100°C, and the drying time can be 5-30 min. The drying can remove liquid components such as solvents. In order to protect the holographic photosensitive film from external light and the like, a protective film can be attached to the side of the holographic photosensitive film away from the substrate. The material of the protective film is not limited, for example, it can be a polymer material. In specific applications, the protective film can be removed, and the holographic photosensitive film can be peeled off from the substrate. In some cases, the substrate can also be a transparent substrate or other functional layer constituting a subsequent holographic optical element. At this time, the holographic photosensitive film can not be peeled off from the substrate. Before the grating structure is formed, the holographic photosensitive film needs to be in a light-free environment.

[0104] As can be seen from the above preparation method, the holographic photosensitive film is obtained by drying the photopolymer composition. In the holographic photosensitive film, the film-forming resin, the writing monomer, the second monomer, and the photoinitiator are all in the original state and have not been polymerized. The components in the holographic photosensitive film can be extracted by solvent extraction, and analyzed and characterized by nuclear magnetic resonance, liquid chromatography tandem mass spectrometry, and the like.

[0105] Referring to Figure 3 The embodiment of the present application also provides a holographic optical element 100, which includes the holographic photosensitive film 101 according to the embodiment of the present application, or includes a grating structure layer obtained from the holographic photosensitive film according to the embodiment of the present application. In some embodiments, the holographic optical element can include the holographic photosensitive film. In some embodiments, the holographic optical element can include the grating structure layer obtained from the holographic photosensitive film.

[0106] The grating structure layer is specifically a resin film layer with a grating structure obtained after the holographic photosensitive film is exposed and post-processed. The exposure operation can specifically include: exposure by using two coherent lights generated by a laser. The laser can include a 457nm blue laser, a 532nm green laser, and a 640nm red laser. The exposure power density can be 0.5mW / cm 2 , and the exposure time can be about 60s. The post-processing operation can specifically include: bleaching the exposed sample using a white light LED or a UV light source for 5-60min.

[0107] In an embodiment, as shown in Figure 3 , the holographic optical element 100 includes a holographic photosensitive film 101 and a transparent substrate 102 located on one side or both sides of the holographic photosensitive film 101. The material of the transparent substrate 102 can be glass, polymer material, etc. A bonding layer 103 can also be provided between the holographic photosensitive film 101 and the transparent substrate 102. The material of the bonding layer 103 can be PVB (polyvinyl butyral).

[0108] In a specific embodiment, the holographic optical element is a glass sandwich film module, which includes glass, PVB film, holographic photosensitive film, PVB film, and glass stacked and pressed together in sequence.

[0109] The glass sandwich film module can be prepared in the following manner:

[0110] The glass, PVB film, holographic photosensitive film, PVB film, and glass are stacked in sequence, vacuumed, and then placed in a high-temperature and high-pressure reaction kettle for sandwich film processing, with a temperature of 100-150℃ and a pressure of 5-15bar. After cooling, the glass sandwich film module is obtained. According to the preparation method of the glass sandwich film module, an automobile windshield can be prepared. The holographic photosensitive film of the present application is used to prepare the glass sandwich film module, and after the above sandwich film processing, the holographic photosensitive film has no defects in appearance and does not appear macroscopic phase separation.

[0111] When the holographic photosensitive film 101 is subjected to the above exposure and post-processing operations, a grating structure layer can be obtained. At this time, the holographic optical element includes the grating structure layer obtained from the holographic photosensitive film 101, and the holographic optical element can be a holographic grating. Continue to refer to Figure 2The process of forming the grating structure layer of the holographic photosensitive film in the present application is as follows: under the irradiation exposure of two coherent lasers, the photoinitiator initiates the free radical polymerization reaction of the writing monomer in the coherent bright area, so that the coherent bright area and the coherent dark area with different polymer density and refractive index are formed, and the grating structure with periodic distribution of refractive index is obtained; in the subsequent post-processing process, the photoinitiator initiates the cationic polymerization reaction of the second monomer, and forms a more stable three-dimensional network structure with the polyacrylate resin; and finally a resin film layer with high thermal stability and grating structure, i.e. the grating structure layer, is obtained.

[0112] The photopolymer composition, the holographic photosensitive film and the holographic optical element described above in the embodiments of the present application can be applied in multiple fields, for example, can be applied in the fields of holographic display, holographic storage, anti-counterfeiting identification, etc. Specifically, for example, can be applied in head-up display devices (HUD), AR / VR glasses, holographic diffusion screens, holographic projection, holographic memories, etc. Specifically in vehicles, can be applied in instrument panels, central control screens, windshields, etc. In an embodiment, can be applied in the field of vehicle-mounted head-up display to prepare automobile windshields.

[0113] The embodiments of the present application also provide a display device comprising the holographic optical element described above in the embodiments of the present application, specifically, comprising the grating structure layer obtained from the holographic photosensitive film. The display device may, for example, be a head-up display device, specifically, for example, an augmented-reality head-up display device (AR-HUD).

[0114] The technical solutions of the present application are further described below in multiple embodiments.

[0115] Embodiment 1

[0116] (1) Photopolymer composition

[0117] 27 wt. % P(MMA-co-GMA) resin (Mw is 300,000), 38 wt. % (9,9-bis[4-(2-acryloyloxyethoxy) phenyl] fluorene) writing monomer, 33 wt. % epoxy monomer 9,9-di[(2,3-epoxypropoxy) phenyl] fluorene as shown in formula (A25), 1 wt. % visible light radical type initiator, 1 wt. % cationic photoinitiator and dimethylformamide, methanol solvent are mixed, stirred overnight to obtain a slurry, i.e. the photopolymer composition. In this embodiment, the solubility parameter δ of the writing monomer is 19.3 (J / cm 3 ) 1 / 2 , the solubility parameter δ of the epoxy monomer is 22.5 (J / cm 3 ) 1 / 2The difference in solubility parameters between the two is Δδ = 3.2 (J / cm³). 3 ) 1 / 2 .

[0118] (2) Preparation of holographic photosensitive film

[0119] The obtained slurry is filtered and coated onto a substrate, and then baked at 60℃-100℃ for 5min-30min to remove the solvent, resulting in a holographic photosensitive film with a thickness of 10 micrometers attached to the substrate. A protective film is then attached to the side of the holographic photosensitive film facing away from the substrate.

[0120] (3) Glass laminated module preparation

[0121] Glass, PVB film, HOE film material, PVB film and glass are stacked in sequence, and after vacuuming, they are placed in a high temperature and high pressure reactor for film lamination treatment. The temperature is 100-150℃ and the pressure is 5-15 bar. After cooling, glass laminated module is obtained.

[0122] (4) Exposure and post-processing processes

[0123] Using a 457nm blue laser, a 532nm green laser, and a 640nm red laser at a ratio of 0.5mW / cm² 2 The sample is exposed to a power density of 60s, and then bleached with a white LED or UV light source for 5-60 minutes after exposure to form a grating structure layer.

[0124] Characterization analysis of samples

[0125] The glass interlayer module obtained in Embodiment 1 of this application has no defects in appearance. Figure 4 From left to right, (a), (b), and (c) are photographs of the glass-laminated module of Example 1 under fluorescent light, laser transmitted light, and after laser exposure, respectively. Figure 4 It can be seen that no macroscopic phase separation phenomenon occurred in the glass laminated module.

[0126] Transmittance, diffraction efficiency, and haze were measured using a UV-Vis spectrophotometer and a haze meter to test the grating structure layer. The test sample was prepared by coating a photopolymer composition onto a polyethylene terephthalate (PET) substrate film, drying it to obtain a 10-micron-thick holographic photosensitive film, and then exposing and post-processing it.

[0127] Figure 5 This is the ultraviolet-visible absorption spectrum of the grating structure layer in Embodiment 1 of this application. Figure 5 It can be seen that the diffraction efficiency of the grating structure layer prepared by the photopolymer composition of Example 1 of this application is 123%, and the average transmittance is 87.2%. In addition, the haze of the grating structure layer was measured to be 1.8%.

[0128] wherein the diffraction efficiency can be calculated according to the UV-Vis absorption spectrum by first determining the minimum transmittance (T B ) of the reflection peak and the transmittance (T A ) of the baseline, which is the ordinate value of the intersection of the peak value of the minimum transmittance and the baseline, and then calculating the diffraction efficiency η according to the following formula.

[0129]

[0130] Figure 6 is the UV-Vis absorption spectrum of the grating structure layer of Example 1 at different aging times. The aging is specifically performed in an 85°C oven. It can be known from Figure 6 that the grating structure layer is stable in performance after aging in the 85°C oven for 1000h, the average transmittance is >75%, the T 400nm transmittance decreases by less than 5%, and the diffraction peak drifts by <5nm. It is also measured that the haze is less than 3% after aging for 1000h. It can be known that the grating structure layer prepared from the photopolymer composition of Example 1 has excellent thermal aging stability.

[0131] Example 2

[0132] The epoxy monomer in Example 1 is replaced by an epoxy monomer [(2,5-dimethylphenoxy)methyl]oxirane as shown in formula (A9), and the content is unchanged, and the others are the same as in Example 1. In this example, the solubility parameter of the writing monomer is δ = 19.3 (J / cm 3 ) 1 / 2 , the solubility parameter of the epoxy monomer is δ = 19.45 (J / cm 3 ) 1 / 2 , and the difference Δδ between the solubility parameters of the two is Δδ = 0.15 (J / cm 3 ) 1 / 2 .

[0133] Characterization analysis of the sample

[0134] The glass film sandwich module obtained in Example 2 has no defects in appearance. Figure 7 From left to right, (a), (b), (c) are respectively photos of the glass film sandwich module of Example 2 under a daylight lamp, under laser transmission light, and after laser exposure. It can be known from Figure 7 that the glass film sandwich module does not have macroscopic phase separation phenomenon.

[0135] Figure 8 is the UV-Vis absorption spectrum of the grating structure layer of Example 2. It can be known from Figure 8It can be seen that the diffraction efficiency of the grating structure layer prepared by the photopolymer composition of Example 1 of this application is 138%, and the average transmittance is 81.2%. In addition, the haze of the grating structure layer was measured to be 2.3%.

[0136] Figure 9 This is the UV-Vis absorption spectrum of the grating structure layer in Embodiment 2 of this application at different aging times. The aging process was specifically carried out in an oven at 85°C. Figure 9 It can be seen that the grating structure layer has stable performance after aging in an 85℃ oven for 1000 hours, with an average light transmittance >75%. 400nm The light transmittance decreased by less than 5%, and the diffraction peak shift changed by less than 5 nm. Furthermore, the haze was measured to be less than 3% after 1000 hours of aging. Therefore, the grating structure layer prepared by the photopolymer composition of Example 1 of this application exhibits excellent thermal aging stability.

[0137] Example 3

[0138] In Example 1, the epoxy monomer was replaced with the vinyl ether monomer phenyl vinyl ether shown in formula (B1), with the content remaining unchanged, and everything else the same as in Example 1. In this example, the monomer's δ was written as 19.3 (J / cm). 3 ) 1 / 2 The δ of the vinyl ether monomer is 15.7 (J / cm). 3 ) 1 / 2 The difference in solubility parameters between the two is Δδ = 3.6 (J / cm³). 3 ) 1 / 2 .

[0139] Characterization analysis of samples

[0140] The glass interlayer module obtained in Embodiment 3 of this application has no defects in appearance. Figure 10 From left to right, (a), (b), and (c) are photographs of the glass-laminated module of Example 3 under fluorescent light, laser transmitted light, and after laser exposure, respectively. Figure 10 It can be seen that no macroscopic phase separation phenomenon occurred in the glass laminated module.

[0141] Figure 11 This is the ultraviolet-visible absorption spectrum of the grating structure layer in Embodiment 3 of this application. Figure 11 It can be seen that the diffraction efficiency of the grating structure layer prepared by the photopolymer composition of Example 1 of this application is 132.1%, and the average transmittance is 80.5%. In addition, the haze of the grating structure layer was measured to be 2.7%.

[0142] Figure 12 This is the UV-Vis absorption spectrum of the grating structure layer in Embodiment 3 of this application at different aging times. The aging process was specifically carried out in an oven at 85°C. Figure 12It can be seen that the performance of the grating structure layer is stable after aging in the 85℃ oven for 1000h, the average transmittance is >75%, T 400nm The transmittance reduction is less than 5%, the diffraction peak drift change is <5nm. It is also measured that the haze is less than 3% after aging for 1000h. It can be seen that the grating structure layer prepared by the photopolymer composition of the embodiment 3 of the present application has excellent thermal aging stability.

[0143] Comparative Example 1

[0144] The epoxy monomer in the embodiment 1 is replaced by epoxy monomer 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylmethyl carboxylate, the content is unchanged, and the others are the same as in the embodiment 1. In the comparative example, the solubility parameter of the writing monomer is δ = 19.3 (J / cm 3 ) 1 / 2 , the solubility parameter of the epoxy monomer is δ = 6.26 (J / cm 3 ) 1 / 2 , and the difference in solubility parameter Δδ of the two is 13 (J / cm 3 ) 1 / 2 .

[0145] The structural formula of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylmethyl carboxylate is as follows:

[0146] Characterization analysis of samples

[0147] The glass film sandwich module obtained in the comparative example 1 of the present application has obvious appearance defects, and macroscopic phase separation occurs at the edge and the middle. Figure 13 From left to right (a), (b), (c) are respectively the photos of the glass film sandwich module of the comparative example 1 under the daylight lamp, the laser transmission light and after laser exposure. It can be seen from the photos that Figure 13 macroscopic phase separation occurs obviously at the edge and the middle of the glass film sandwich module.

[0148] Figure 14 is a comparison chart of the ultraviolet-visible light absorption spectrum of the grating structure layer of the embodiment 1 and the comparative example 1 of the present application. It can be seen from the chart that Figure 14 the diffraction efficiency of the grating structure layer of the comparative example 1 is 62%, and the average transmittance is 85.8%; the diffraction efficiency and the transmittance of the grating structure layer of the embodiment 1 are obviously higher than those of the comparative example 1, which is because the phase separation occurs at the boundary and the middle of the film sandwich module in the comparative example 1, which affects the display effect of the film sandwich module after exposure. The haze of the grating structure layer of the comparative example 1 is 1.6%.

[0149] Comparative Example 2

[0150] The epoxy monomer in Example 1 is replaced by epoxy monomer 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylmethyl carboxylate modified ε-caprolactone, the content is unchanged, and the rest is the same as in Example 1. In this comparative example, the delta of the writing monomer is 19.3 (J / cm 3 ) 1 / 2 , the delta of the epoxy monomer 4 is 10.1 (J / cm 3 ) 1 / 2 , and the difference between the solubility parameters of the two is delta = 9.2 (J / cm 3 ) 1 / 2 .

[0151] The structural formula of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylmethyl carboxylate modified ε-caprolactone is: n = 1.

[0152] Characterization analysis of the sample

[0153] The glass film sandwich module obtained in Comparative Example 2 of the present application has obvious appearance defects, and macroscopic phase separation occurs at the edges and in the middle. Figure 15 From left to right, (a), (b), (c) are respectively the photos of the glass film sandwich module of Comparative Example 2 under daylight lamp, laser transmission light, and after laser exposure. It can be seen from the photos that Figure 15 macroscopic phase separation occurs at the edges and in the middle of the glass film sandwich module.

[0154] Figure 16 is a comparison chart of the ultraviolet-visible light absorption spectrum of the grating structure layer of Example 1 and Comparative Example 2 of the present application. It can be known from the chart that Figure 16 the diffraction efficiency of the grating structure layer of Comparative Example 2 is 51.7%, and the average light transmittance is 88.3%; the diffraction efficiency and light transmittance of the grating structure layer of Example 1 are obviously higher than those of Comparative Example 2, which is because the phase separation occurs at the edges and in the middle of the film sandwich module in Comparative Example 2, affecting the display effect of the film sandwich module after exposure. The haze of the grating structure layer of Comparative Example 2 is 1.8%.

[0155] As can be seen from the above, the photopolymer compositions of Comparative Example 1 and Comparative Example 2 cannot withstand the high-temperature and high-pressure film sandwich processing, and cannot meet the application requirements of the vehicle head-up display device.

[0156] It should be understood that the first, second, and various numerical numbers involved herein are only for the convenience of differentiation in description, and do not limit the scope of the present application.

[0157] In the present application, "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it.

[0158] In this application, "at least one" means one or more, "multiple" means two or more. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can represent: a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0159] In this application, "-" represents a range value, including both end point values. For example, the value of a can be 0.5-15, indicating that the value of a can be between 0.5 and 15, and including the end point values 0.5 and 15.

[0160] It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and part or all of the steps can be executed in parallel or in sequence. The execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A photopolymer composition, characterized by, The photopolymer composition comprises a main component, the main component comprises a side chain epoxy group-containing polyacrylate resin, an aromatic ring structure-containing acrylate writing monomer, a second monomer and a photoinitiator, the second monomer comprises an aromatic ring structure-containing epoxy monomer and / or an aromatic ring structure-containing vinyl ether monomer.

2. The photopolymer composition according to claim 1, wherein The aromatic ring structure-containing epoxy monomer comprises one or more of an aromatic ring structure-containing mono- or poly-glycidyl ether, an aromatic ring structure-containing mono- or poly-oxetane, an aromatic ring structure-containing mono- or poly-alicyclic epoxy monomer.

3. The photopolymer composition according to claim 1, wherein The aromatic ring structure-containing vinyl ether monomer comprises an aromatic ring structure-containing mono- or poly-vinyl ether monomer.

4. Photopolymer composition according to any of claims 1 to 3, characterized in that The aromatic ring structure comprises an aromatic ring structure and / or an aromatic heterocyclic ring structure.

5. Photopolymer composition according to any of claims 1 to 4, characterized in that The aromatic ring structure comprises one or more of a substituted or unsubstituted benzene ring structure, a substituted or unsubstituted biphenyl structure, a substituted or unsubstituted naphthalene ring structure, a substituted or unsubstituted anthracene ring structure, a substituted or unsubstituted fluorene ring structure, a substituted or unsubstituted pyrrole structure, a substituted or unsubstituted benzopyrrole structure.

6. The photopolymer composition according to any one of claims 1 to 5, wherein The aromatic ring structure-containing epoxy monomer comprises any one or more of the monomers represented by formula (A1) to formula (A25):

7. The photopolymer composition according to any one of claims 1 to 6, wherein The aromatic ring structure-containing vinyl ether monomer comprises any one or more of the monomers represented by formula (B1) to formula (B24):

8. The photopolymer composition according to any one of claims 1 to 7, wherein The solubility parameter difference Δδ between the aromatic ring-containing acrylate-based writing monomer and the second monomer is ≤ 5 (J / cm 3 ) 1 / 2 .

9. The photopolymer composition according to any one of claims 1 to 8, wherein In the main component, the mass percentage content of the second monomer is 5%-40%.

10. The photopolymer composition according to any one of claims 1 to 9, wherein The aromatic ring structure-containing acrylate writing monomer comprises one or more of an aromatic ring structure-containing mono- or poly-acrylate and an aromatic ring structure-containing mono- or poly-methacrylate; and / or, the side chain epoxy group-containing polyacrylate resin comprises an acrylate homopolymer and / or an acrylate copolymer.

11. The photopolymer composition according to any one of claims 1 to 10, wherein The photoinitiator comprises a visible light radical type photoinitiator capable of initiating radical polymerization of the aromatic ring structure-containing acrylate writing monomer and a cationic type photoinitiator capable of initiating cationic polymerization of the second monomer.

12. The photopolymer composition according to any one of claims 1 to 11, wherein In the main component, the mass percentage content of the side chain epoxy group-containing polyacrylate resin is 20%-50%; And / or, the mass percentage content of the aromatic ring structure-containing acrylate writing monomer is 20%-50%; And / or, the mass percentage content of the photoinitiator is 0.2%-15%.

13. The photopolymer composition according to any one of claims 1 to 12, wherein The photopolymer composition further comprises a solvent, the solvent comprises one or more of dimethylformamide, an alcohol solvent, a ketone solvent.

14. The photopolymer composition according to any one of claims 1 to 13, wherein The film material obtained after the photopolymer composition is formed undergoes a compression treatment at a temperature of 100°C-150°C and a pressure of 5bar-15bar, and has no defects in appearance and does not undergo macroscopic phase separation.

15. The photopolymer composition according to any one of claims 1 to 14, wherein The grating structure layer prepared using the photopolymer composition has an average transmittance greater than or equal to 80% in the range of 400nm-800nm and a diffraction efficiency greater than 100%.

16. The photopolymer composition of claim 15, wherein After the grating structure layer is aged at 85°C for 1000 hours, the average transmittance in the range of 400nm-800nm is greater than 75% and the diffraction peak drift change is less than 5nm.

17. Use of the photopolymer composition according to any one of claims 1 to 16 in holographic display, holographic storage or security marking.

18. A holographic photosensitive film, characterized by comprising: obtained by film formation from the photopolymer composition according to any one of claims 1 to 16.

19. A method for producing a holographic photosensitive film, characterized by, comprising: coating the photopolymer composition according to any one of claims 1 to 16 on a substrate, and obtaining a holographic photosensitive film attached to the substrate after drying.

20. A holographic optical element, characterized by comprising the holographic photosensitive film according to claim 18, or comprising a grating structure layer obtained from the holographic photosensitive film according to claim 18.

21. The holographic optical element of claim 20, wherein further comprising a transparent substrate on one side or on both sides of the holographic photosensitive film or the grating structure layer.

22. A display device, characterized by comprising the holographic optical element according to any one of claims 20 to 21.

Images