CN115602201A - Photopolymer holographic storage material, holographic optical disk and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of holographic polymer materials, and in particular relates to a photopolymer holographic storage material, a holographic disc and a preparation method thereof. The photopolymer holographic storage material is prepared from raw materials in the following mass ratio: MMA:NMP:AIBN:PQ=100:5-25:0.7-1:1-1.5. The photopolymer holographic storage material significantly improves the optical performance of the material by doping NMP (N-methylpyrrolidone) in PQ/PMMA (phenanthrenequinone/polymethylmethacrylate) for proportioning.

Description

A kind of photopolymer holographic storage material, holographic disc and preparation method thereof

technical field

The invention belongs to the technical field of holographic polymer materials, and in particular relates to a photopolymer holographic storage material, a holographic disc and a preparation method thereof.

Background technique

With the advent of the era of big data and the rapid development of social activities such as mobile Internet, e-commerce and social media, the amount of data generated by human society has exploded. The generation and dissemination of massive data urgently requires high-density, ultra-long-term and low-cost information storage technology. Volume holographic storage technology has the characteristics of high storage density, fast transmission rate and good redundancy, and is considered to be a storage technology with great potential. Holographic storage uses light waves as the main body, and the optical storage density can be improved by adjusting parameters such as amplitude, phase, and polarization. In recent years, increasing the dimensionality of holographic recording by using polarization information has received a lot of attention, but these materials have some inherent defects, such as: photoinduced refractive index change crystals, azo-based materials and polymer-dispersed liquid crystals and many other polarization-sensitive materials It cannot meet the requirements of holographic recording and storage. The main disadvantages of these materials are that their manufacturing industry is complex, expensive, the grating can be rewritable and the material itself is unstable.

The Chinese invention patent with publication number CN112812210A discloses a PQ/PMMA photopolymer material thermal polymerization process and PQ/PMMA photopolymer material and its holographic disc. The invention uses MMA, AIBN and PQ to prepare photopolymer , stable performance, can record and read multiple times at one time, easy to process into thick holographic materials, and the photoshrinkage is very low, but the diffraction efficiency of the PQ-PMMA (phenanthrenequinone-polymethyl methacrylate) photopolymer is not high , limiting its application in the field of high-density holographic storage.

Contents of the invention

In order to overcome the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide a photopolymer holographic storage material, a holographic disc and a preparation method thereof, the holographic storage material has higher diffraction efficiency, response efficiency and photosensitivity sensitivity.

In order to solve the above-mentioned technical problems, the technical solution adopted in the present invention is: a photopolymer holographic storage material prepared from raw materials with the following mass ratios:

MMA (methyl methacrylate): NMP (N-methylpyrrolidone): AIBN (azobisisobutyronitrile): PQ (phenanthrenequinone)=100:5-25:0.7-1:1-1.5.

Another technical solution adopted by the present invention is: the preparation method of the above-mentioned photopolymer holographic storage material, comprising the following steps:

S1: MMA, NMP, AIBN and PQ are weighed and mixed according to the mass ratio of 100:5~25:0.7~1:1~1.5, and then ultrasonically oscillated to obtain a mixed solution;

S2: putting the mixed solution into a water bath and heating and stirring to obtain a viscous substance;

S3: The sticky substance is baked and then cooled to obtain a photopolymer holographic storage material.

Another technical solution adopted by the present invention is: a holographic optical disc, which is prepared by using the above-mentioned photopolymer holographic storage material.

The beneficial effects of the present invention are: the NMP-doped PQ/PMMA photopolymer holographic storage material of the present invention, by doping NMP (N-methylpyrrolidone) in PQ/PMMA (phenanthrenequinone/polymethyl methacrylate) ) for the proportioning, which significantly improves the optical properties of the material. Compared with the traditional PQ/PMMA material, the material of the present invention has higher diffraction efficiency, refractive index modulation, response efficiency and photosensitivity, so it is more suitable for optical holographic storage; the preparation method of the present invention has simple process and low raw material cost lower, making it more competitive in holographic storage materials.

Description of drawings

Fig. 1 shows the diffraction efficiency test figure of embodiment one, two and comparative example one of the present invention;

Fig. 2 shows the test charts of the degree of refractive index modulation of Embodiments 1 and 2 of the present invention and Comparative Example 1;

Fig. 3 shows the photosensitivity test diagrams of Embodiments 1 and 2 of the present invention and Comparative Example 1.

detailed description

In order to describe the technical content, achieved goals and effects of the present invention in detail, the following descriptions will be made in conjunction with the embodiments and accompanying drawings.

The most critical idea of the present invention is: by doping NMP (N-methylpyrrolidone) in PQ/PMMA (phenanthrenequinone/polymethyl methacrylate) for proportioning, the optical performance of the material is significantly improved.

A photopolymer holographic storage material of the present invention is prepared from raw materials with the following mass ratios:

MMA (methyl methacrylate): NMP (N-methylpyrrolidone): AIBN (azobisisobutyronitrile): PQ (phenanthrenequinone)=100:5-25:0.7-1:1-1.5.

As can be seen from the above description, the beneficial effects of the present invention are: by doping NMP (N-methylpyrrolidone) in PQ/PMMA (phenanthrenonequinone/polymethylmethacrylate) for proportioning, the optical properties of the material are significantly improved , Compared with the traditional PQ/PMMA material, the material of the present invention has higher diffraction efficiency, refractive index modulation, response efficiency and photosensitivity, so it is more suitable for optical holographic storage.

The proportion of NMP will affect the photosensitivity and diffraction efficiency. Too little NMP content will not significantly improve the diffraction efficiency and photosensitivity; too much NMP will prolong the polymerization time and even fail to polymerize to the desired viscosity.

The proportion of AIBN will affect the time of stirring in the water bath. Excessive AIBN will lead to severe polymerization and prone to implosion.

The ratio of PQ will affect the diffraction efficiency and photosensitivity. Excessive PQ will cause PQ to remain and cannot be dissolved.

Another technical solution adopted by the present invention is: the preparation method of the above-mentioned photopolymer holographic storage material, comprising the following steps:

S1: MMA, NMP, AIBN and PQ are weighed and mixed according to the mass ratio of 100:5~25:0.7~1:1~1.5, and then ultrasonically oscillated to obtain a mixed solution;

S2: Put the mixed solution into a water bath and heat and stir to obtain a viscous substance;

S3: The sticky substance is baked and then cooled to obtain a photopolymer holographic storage material.

It can be seen from the above description that the preparation method has simple process and low cost of raw materials, making it more competitive in holographic storage materials.

Further, when heating and stirring in S2, the temperature of the water bath is 56-62°C. Preferably, the temperature of the water bath is 60°C.

From the above description, it can be known that the temperature of the water bath is too low, the reaction time is too long and even the thermal polymerization reaction cannot be initiated. If the temperature of the water bath is too high, the reaction rate will be difficult to control, and implosion will easily occur.

Further, when heating and stirring, the stirring speed is 600-1000 r/min. Preferably, the stirring speed is 700-900 r/min.

Further, when heating and stirring, the stirring time is 1-2 hours. Preferably, the stirring time is 1.5～1.7h

From the above description, it can be seen that too short stirring time will make the viscosity of the monomer insufficient, which will affect the forming after pouring into the mold, and too long stirring time will make the viscosity of the monomer too high, which will affect the operation of pouring into the mold.

Further, during ultrasonic oscillation, the oscillation time is 10-20 minutes. Preferably, the shaking time is 14 to 17 minutes

From the above description, it can be seen that ultrasound will affect the chain length of the polymer. If the ultrasound time is too short, PQ cannot be completely dissolved, and if the ultrasound time is too long, the internal monomers have already started to polymerize.

Another technical solution adopted by the present invention is: a holographic optical disc, which is prepared by using the above-mentioned photopolymer holographic storage material.

Embodiment one of the present invention is:

A method for preparing a photopolymer holographic storage material, comprising the following steps:

S1: MMA (methyl methacrylate), NMP (N-methylpyrrolidone), AIBN (azobisisobutyronitrile) and PQ (phenanthrenequinone) are weighed and mixed in a mass ratio of 100:5:1:1 , and then ultrasonically oscillated for 15 minutes to obtain a mixed solution;

S2: Put the mixed solution into a water bath and heat and stir to obtain a viscous substance; when heating and stirring, the temperature of the water bath is set at 60° C., the stirring speed is 800 r/min, and the stirring time is 75 min.

S3: Pour the viscous material into a mold for baking, then cool and release the mold to obtain a photopolymer holographic storage material.

Embodiment two of the present invention is:

The difference between embodiment two and embodiment one is: MMA (methyl methacrylate), NMP (N-methylpyrrolidone), AIBN (azobisisobutyronitrile) and PQ (phenanthrenequinone) by 100:25:1 : 1 mass ratio weighed and mixed.

Embodiment three of the present invention is:

A method for preparing a photopolymer holographic storage material, comprising the following steps:

S1: MMA (methyl methacrylate), NMP (N-methylpyrrolidone), AIBN (azobisisobutyronitrile) and PQ (phenanthrenequinone) are weighed and mixed at a mass ratio of 100:20:0.7:1.5 , and then ultrasonically oscillated for 10 minutes to obtain a mixed solution;

S2: put the mixed solution into a water bath and heat and stir to obtain a viscous substance; when heating and stirring, the temperature of the water bath is set at 56° C., the stirring speed is 600 r/min, and the stirring time is 1 h.

S3: Pour the viscous material into a mold for baking, then cool and release the mold to obtain a photopolymer holographic storage material.

Embodiment four of the present invention is:

A method for preparing a photopolymer holographic storage material, comprising the following steps:

S1: MMA (methyl methacrylate), NMP (N-methylpyrrolidone), AIBN (azobisisobutyronitrile) and PQ (phenanthrenequinone) are weighed and mixed at a mass ratio of 100:25:0.8:1.2 , and then ultrasonically oscillated for 20 minutes to obtain a mixed solution;

S2: Put the mixed solution into a water bath and heat and stir to obtain a viscous substance; when heating and stirring, the temperature of the water bath is set at 62° C., the stirring speed is 1000 r/min, and the stirring time is 2 hours.

S3: Pour the viscous material into a mold for baking, then cool and release the mold to obtain a photopolymer holographic storage material.

Comparative example one of the present invention is:

The difference between Comparative Example 1 and Example 1 is that no NMP (N-methylpyrrolidone) is added, and the mass ratio of MMA:AIBN:PQ is =100:1:1.

The diffraction efficiency of test embodiment one, two and comparative example one, test result is shown in Fig. 1;

Test the refractive index modulation degree of Example 1, 2 and Comparative Example 1, the test results are shown in Figure 2;

Test the photosensitivity of Examples 1, 2 and Comparative Example 1, and the test results are shown in Fig. 3;

For the above test methods, see references: Po Hu, Jinhong Li, Junchao Jin, Xiao Lin, & Xiaodi Tan. Highly Sensitive Photopolymer for Holographic Data Storage Containing Methacryl Polyhedral Oligomeric Silsesquioxane[J].ACSAppl.Mater.Interfaces2022,14,18,21544–21554.

The best diffraction efficiency, the best refractive index modulation degree, the best photosensitivity and the exposure time corresponding to the best diffraction efficiency of Examples 1 and 2 and Comparative Example 1 are summarized, and the summary results are shown in Table 1.

Table 1

It can be seen from Table 1 that MMA, AIBN, and PQ are the raw materials for the preparation of existing PQ/PMMA photopolymer holographic storage materials. When other substances are added, the content of the product-PQ/PMMA polymer will be reduced in theory. Thereby reducing the optical properties of the material. However, comparing the data of Examples 1, 2 and Comparative Example 1 in Table 1, it can be seen that adding NMP can effectively improve the diffraction efficiency, refractive index modulation and photosensitivity of PQ/PMMA, shorten the exposure time, and improve the response time. Among them, the best diffraction efficiency and refractive index modulation show peaks with the increase of NMP addition.

In summary, by doping NMP (N-methylpyrrolidone) in PQ/PMMA (phenanthrenequinone/polymethyl methacrylate) for proportioning, the optical properties of the material are significantly improved, compared with the traditional PQ/ The PMMA material, the material of the present invention has higher diffraction efficiency, refractive index modulation, response efficiency and photosensitivity, so it is more suitable for optical holographic storage.

The preparation method has simple process and low cost of raw materials, making it more competitive in holographic storage materials. Wherein, the too low temperature of the water bath will cause the reaction time to be too long or even fail to initiate the thermal polymerization reaction. If the temperature of the water bath is too high, the reaction rate will be difficult to control, and the phenomenon of implosion will easily occur; if the stirring time is too short, the viscosity of the monomer will be insufficient, which will affect the forming after pouring into the mold; if the stirring time is too long, the viscosity of the monomer will be too high, which will affect The operation of pouring into the mold; if the ultrasonic time is too short, the PQ cannot be completely dissolved, and if the ultrasonic time is too long, the internal monomers have begun to polymerize, and the ultrasonic wave will affect the chain length of the polymer.

The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent transformations made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in related technical fields, are all included in the same principle. Within the scope of patent protection of the present invention.

Claims (7)

1. A photopolymer holographic storage material, characterized in that it is prepared from the raw materials of the following mass ratios: MMA: NMP: AIBN: PQ = 100: 5-25: 0.7-1: 1-1.5. 2. A preparation method of the photopolymer holographic storage material described in claim 1, characterized in that, comprising the following steps: S1: MMA, NMP, AIBN and PQ are weighed and mixed according to the mass ratio of 100:5~25:0.7~1:1~1.5, and then ultrasonically oscillated to obtain a mixed solution; S2: putting the mixed solution into a water bath and heating and stirring to obtain a viscous substance; S3: The sticky substance is baked and then cooled to obtain a photopolymer holographic storage material. 3. The preparation method according to claim 2, characterized in that, when heating and stirring in S2, the temperature of the water bath is 56-62°C. 4. The preparation method according to claim 2, characterized in that, during the heating and stirring, the stirring speed is 600-1000r/min. 5. The preparation method according to claim 2, characterized in that, when heating and stirring, the stirring time is 1-2 hours. 6. The preparation method according to claim 2, characterized in that, during the ultrasonic oscillation, the oscillation time is 10-20 minutes. 7. A holographic optical disc, characterized in that the holographic optical disc is prepared by using the photopolymer holographic storage material described in claim 1.

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