Composition for holographic recording medium and holographic recording medium
By introducing substrate film-forming materials, active monomers, and photoinitiators into the holographic recording medium, and utilizing the unsaturated ring structure to enhance the rigidity and stability of the material, the problems of low photosensitivity and refractive index modulation in the prior art have been solved, and the fabrication of high-performance volume holographic gratings has been realized.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NANCHANG VIRTUAL REALITY RES INST CO LTD
- Filing Date
- 2025-06-06
- Publication Date
- 2026-07-02
Smart Images
Figure PCTCN2025099757-FTAPPB-I100001 
Figure PCTCN2025099757-FTAPPB-I100002 
Figure PCTCN2025099757-FTAPPB-I100003
Abstract
Description
A composition for a holographic recording medium and a holographic recording medium. Technical Field
[0001] This application relates to the field of holographic technology, and more specifically to a composition for a holographic recording medium and a holographic recording medium using the composition for a holographic recording medium. Background Technology
[0002] Holographic technology refers to an optical information technology that utilizes the principle of optical coherence to record the amplitude, phase, and other optical properties of light waves. It is widely used in fields such as holographic anti-counterfeiting and data storage. In this process, the holographic recording medium, as the carrier of the holographic record, is particularly crucial. Typical holographic recording media include: silver halide emulsions, dichromate gelatin, photodegradable polymers, photothermoplastic materials, photoisomerization materials, photorefractive materials (including liquid crystals), metasurface materials, and photopolymers.
[0003] Among these, silver halide latex has a complex post-processing process and easily generates large amounts of waste liquid, polluting the environment; dichromate gelatin, photodegradable polymers, photothermoplastic materials, and photoisomerized materials suffer from low photosensitivity and refractive index modulation; photorefractive materials typically require an additional external electric field, resulting in complex equipment and poor safety; and metasurface materials are difficult to construct and have complex processes. These media cannot be used to fabricate high-performance volume holographic gratings (VHGs). In contrast, photopolymers not only possess advantages such as high photosensitivity, high resolution, and good light transmittance, but also have excellent fabrication processability, gradually becoming the most promising recording medium in the field of volume holographic recording devices.
[0004] An ideal holographic photopolymer recording material should possess high refractive index modulation, a wide spectral response range, excellent photosensitivity, and low haze. Furthermore, to ensure good display performance after exposure, the holographic recording medium must also exhibit good stability, meaning minimal shrinkage. Therefore, this patent primarily focuses on improving material stability through structural design, thereby enhancing stability. Summary of the Invention
[0005] The purpose of this application is to provide a composition for a holographic recording medium and a holographic recording medium using the composition for a holographic recording medium, so as to improve at least some of the above-mentioned technical problems.
[0006] To achieve the above objectives, in a first aspect, embodiments of this application provide a composition for a holographic recording medium, comprising: a substrate film-forming substance, an active monomer, and a photoinitiator;
[0007] The substrate film-forming material is selected from compounds having one of the functional groups selected from isocyanate group, urethane group, amide group, urea group, epoxy group, and hydroxyl group, or obtained by reacting compounds having at least two functional groups. The compound having the isocyanate group includes at least two -NCO structures, and the compound having the hydroxyl group includes at least three -OH structures.
[0008] The compound having an isocyanate group structure must satisfy the following general structural formula;
[0009] R1 is a C-chain skeleton with at least one benzene ring structure, and the relative molecular mass of R1 is not greater than 1000.
[0010] As a preferred embodiment of this application, the compound having an isocyanate group structure is specifically:
[0011] As a preferred embodiment of this application, the refractive index of the compound with the isocyanate group structure is not higher than 1.50.
[0012] As a preferred embodiment of this application, both the compound with the isocyanate group structure and the compound with the hydroxyl group have -F modified branches.
[0013] In a preferred embodiment of this application, the relative molecular mass of the hydroxyl compound is not greater than 3000.
[0014] As a preferred embodiment of this application, the functionality ratio between the isocyanate in the compound with the isocyanate group structure and the hydroxyl group in the compound with the hydroxyl group is not greater than 1:1.02.
[0015] As a preferred embodiment of this application, the active monomer is a C4 to C30 carbon chain having one or more acrylate structures, preferably an acrylate substance having a urethane or carbamate structure in its molecular structure, and in order to increase the refractive index difference with the substrate film-forming material, the refractive index of the active monomer is ≥1.55.
[0016] In a preferred embodiment of this application, the photoinitiator, as a sensitizing agent at a specific wavelength, has a very important influence on the photosensitivity of materials in holographic technology, and is limited by the absorption of a specific wavelength. In this application, the photoinitiator is a compound that is known in nature and commercially available. Taking a 520nm wavelength light source as an example, the photoinitiator is a combination of rose red or rhodamine with n-aminoglycine or ethylenediamine, respectively, or a combination of a boron-containing quaternary ammonium salt with rose red.
[0017] As a preferred embodiment of this application, the content of the substrate film-forming substance is 15% to 60% based on the total amount of the composition, the content of the active monomer is 20% to 50%, and the content of the photoinitiator is 0.01% to 1%.
[0018] Secondly, embodiments of this application also provide a holographic recording medium, which is prepared by the composition of the holographic recording medium described in any one of the first aspects.
[0019] Compared with the prior art, the embodiments of this application provide a composition for a holographic recording medium and a holographic recording medium. The composition for the holographic recording medium includes the following components: a substrate film-forming material, active monomers, and a photoinitiator. The substrate film-forming material mainly uses mechanical support to construct a freely moving spatial network structure for the active monomers, requiring a certain degree of rigidity and thermal stability. Experiments show that introducing unsaturated cyclic structures such as benzene rings, naphthalene rings, and niobium rings into the structure can significantly improve the rigidity and thermal stability of the material, thereby providing a strong spatial network structure for the free movement of active monomers and ensuring the display effect as a holographic recording medium. Detailed Implementation
[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort should fall within the scope of protection of this application.
[0021] Example 1
[0022] Under red light protection, 30-35% of polyether triol, 40% of polyethylene glycol o-phenyl ether acrylate (OPPEA) active monomer, 0.1% rose red and 0.3% N-phenylglycine are pre-mixed and thoroughly mixed. Then, 8-12% dimethyl biphenyl diisocyanate and 0.1% organotin are added and mixed again to obtain a clear photosensitive solution. Then, under red light protection, a quantitative amount of the above photosensitive solution is drawn and siphoned into a film in a glass box of a specific thickness. In this embodiment, the box thickness is 10 μm. Finally, after the siphoning is completed, the glass box is protected from light with tin foil and placed in an oven at 70°C for 1 hour.
[0023] Example 2
[0024] Under red light protection, 30-35% of polyether triol, 40% of polyethylene glycol o-phenyl phenyl ether acrylate (OPPEA) active monomer, 0.1% rose red, and 0.3% N-phenylglycine are premixed and thoroughly mixed. Then, 8-12% of 4,4-phenylamine is added. ， Methylenebis(phenyl isocyanate) and 0.1% organotin are added and mixed again to obtain a clear photosensitive solution. Then, under red light protection, a quantitative amount of the above photosensitive solution is drawn and siphoned into a film in a glass box of a specific thickness. In this embodiment, the box thickness is 10 μm. Finally, after the siphoning is completed, the glass box is protected from light with tin foil and placed in an oven at 70°C for 1 hour.
[0025] Example 3
[0026] Under red light protection, 30-35% of polyether triol, 40% of polyethylene glycol o-phenyl phenyl ether acrylate (OPPEA) active monomer, 0.1% of rose red and 0.3% of N-phenylglycine are pre-mixed and thoroughly mixed. Then, 8-12% of naphthalene-1,5-diisocyanate and 0.1% of organotin are added and mixed again to obtain a clear photosensitive solution. Then, under red light protection, a quantitative amount of the above photosensitive solution is drawn and siphoned into a film in a glass box of a specific thickness. In this embodiment, the box thickness is 10 μm. Finally, after the siphoning is completed, the glass box is covered with tin foil to protect it from light and placed in an oven at 70°C for 1 hour.
[0027] Comparative Example 1
[0028] Under red light protection, 30-35% of polyether triol, 40% of OPPEA active monomer, and 0.1% of rose red + 0.3% of N-phenylglycine are pre-mixed and thoroughly mixed. Then, 8-12% of 4,4-diisocyanate dicyclohexylmethane monomer and 0.1% of organotin are added and mixed again to obtain a clear photosensitive solution. Then, under red light protection, a quantitative amount of the above photosensitive solution is drawn and siphoned into a film in a glass box of a specific thickness. In this embodiment, the box thickness is 10 μm. Finally, after the siphoning is completed, the glass box is protected from light with tin foil and placed in an oven at 70°C for 1 hour.
[0029] Table 1: Test Results of Examples 1-3 and Comparative Examples
[0030] As shown in Table 1, the holographic recording media in Examples 1-3, due to the defined isocyanate structure, exhibit significantly improved diffraction efficiency and shrinkage compared to the comparative holographic recording media. This is because introducing unsaturated cyclic structures such as benzene rings, naphthalene rings, and niobium rings into the isocyanate structure significantly enhances the material's rigidity and thermal stability, thereby providing a robust spatial network structure for the free movement of active monomers and ensuring the display effect as a holographic recording medium. Furthermore, the organotin in the above examples serves as a catalyst to catalyze the film-forming material of the substrate.
[0031] It should be noted that the composition for holographic recording media provided in this application may also introduce some small molecule substances with high boiling points as toughening agents, preferably with a boiling point greater than 200 degrees Celsius.
[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A composition for a holographic recording medium, characterized in that, include: Substrate film-forming material, active monomer, photoinitiator; The substrate film-forming material is selected from compounds having one of the functional groups selected from isocyanate group, urethane group, amide group, urea group, epoxy group, and hydroxyl group, or obtained by reacting compounds having at least two functional groups. The compound having the isocyanate group includes at least two -NCO structures, and the compound having the hydroxyl group includes at least three -OH structures. The compound having an isocyanate group structure must satisfy the following general structural formula; R1 is a C-chain skeleton with at least one benzene ring structure, and the relative molecular mass of R1 is not greater than 1000.
2. The composition for a holographic recording medium as described in claim 1, characterized in that, Compounds with isocyanate group structures are specifically:
3. The composition for a holographic recording medium as described in claim 1, characterized in that, The refractive index of the compound with the isocyanate group structure is not higher than 1.
50.
4. The composition for a holographic recording medium as described in claim 1, characterized in that, Both the compounds with isocyanate groups and the compounds with hydroxyl groups have -F modified branches.
5. The composition for a holographic recording medium as described in claim 1, characterized in that, The relative molecular mass of the hydroxyl compounds is not greater than 3000.
6. The composition for a holographic recording medium as described in claim 1, characterized in that, The functionality ratio between the isocyanate in the compound having an isocyanate group structure and the hydroxyl group in the compound having a hydroxyl group is not greater than 1:1.
02.
7. The composition for a holographic recording medium as described in claim 1, characterized in that, The active monomer is a C4 to C30 carbon chain having one or more acrylate structures, and the refractive index of the active monomer is ≥1.
55.
8. The composition for a holographic recording medium as described in claim 1, characterized in that, The photoinitiator is a combination of rose red or rhodamine with n-aminoglycine or ethylenediamine, or a combination of boron-containing quaternary ammonium salt and rose red.
9. The composition for a holographic recording medium as described in claim 1, characterized in that, The content of the substrate film-forming substance is 15% to 60% based on the total amount of the composition, the content of the active monomer is 20% to 50%, and the content of the photoinitiator is 0.01% to 1%.
10. A holographic recording medium, characterized in that, It is prepared by the composition for holographic recording media as described in any one of claims 1-9.