JPS62123489A - Hologram recording photosensitive materials and manufacture of hologram - Google Patents

Abstract

PURPOSE:To improve the sensitivity to Ar laser light and improve the moistureproof property, the thermal resistance, and the light resistance by using a thioflavin T as the cross-linking agent of a polymer including a carbazole ring which constitutes the base of a hologram recording body. CONSTITUTION:The polymer including a carbazole ring is used as the base and the thioflavin T is used as the cross-linking agent to form hologram recording photosensitive materials. If the thioflavin and an iodoform are used as the cross-linking agent, the sensitivity is made higher. Hologram recording of these photosensitive materials is performed by a hologram exposure optical system. That is, the laser light emitted from a laser 1 passes a shutter 2 and is reflected on a mirror 3, and a photosensitive plate 9 is irradiated with the light which is reflected on a half mirror 4 and passes a mirror 6 and a collimator lens 7 and the light, which is transmitted through the half mirror 4 and passes a mirror 5 and a collimator lens 8, to record a hologram. Thus, holograms of high quality are produced.

Description

[Detailed Description of the Invention] [Summary] Characteristics such as sensitivity were improved by using thioflavin T as a crosslinking agent for a polymer containing a Kartuzole ring, which constitutes the main ingredient of a holographic recording material.

[Industrial application field]

The present invention relates to a photosensitive material for hologram recording, and more particularly to a photosensitive material used in a method of recording a hologram using a photochemical crosslinking reaction in a polymer.

A hologram is a recording of the interference wavefront of coherent light such as a laser on a photographic film, etc., and can be used not only to record optical images but also to record information or optical elements that utilize the diffraction phenomenon, such as bar code readers. Used in beam scanners, etc.

When creating this hologram element, the characteristics that the hologram recording material should have are: (1) High sensitivity (2) High hologram diffraction efficiency (3) High resolution (4) Hologram is required to have excellent environmental resistance.

When using a hologram as an optical element, a semiconductor laser (780 nm) or a He-Ne laser beam is used as the reproduction light.
A laser (633 nm) is often used, and the recording light is
In order to suppress chromatic aberration, it is desirable to use light with a small wavelength difference from these reproduction lights, and gas lasers (He-Ne lasers, A
r laser (4880 m), etc.) light is desirable. However, the photosensitive range of conventional polymer photosensitive materials is in the ultraviolet region, and the longer the wavelength, the lower the sensitivity becomes. Therefore, regarding the photosensitivity in item (1), the visible light Ar laser (488nrn
) High sensitivity to light is desirable.

[Conventional technology]

The photosensitive material for hologram recording is generally made by bleaching silver salt, which is used as an ordinary photographic material, but other materials such as dichromate gelatin are also used as hologram recording materials. There is. Although these silver salts and dichromate gelatin have high sensitivity, the hologram formation process is complicated, and because they use a gelatin film as a binder, they have low environmental resistance such as moisture resistance, heat resistance, and light resistance. There is a problem.

On the other hand, as a hologram recording material with excellent environmental resistance, a polymer hologram recording material containing an organic halogen compound and mainly composed of polyvinylcarbazole has been proposed (for example, JP-A No. 53-15153, JP-A No. Showa 5
4-101343, and Japanese Patent Application Laid-Open No. 54-102140)
.

[Problem that the invention seeks to solve]

The polymer hologram recording material records a hologram using a photochemical crosslinking reaction between polymers,
An organic halogen compound is used as a crosslinking agent that participates in this crosslinking reaction. When carbon tetraiodide is used as an organic halogen compound, the long wavelength end of absorption is approximately 540 nm, and although a hologram can be created using an Ar laser, it tends to gel during the coating stage and affects the chemical stability of the recording material. There's a problem. In addition, when iodoform is used as an organic halogen compound, although it is chemically stable, the long wavelength end of absorption is approximately 450 nm, and there is a problem that the sensitivity is low for light with wavelengths longer than 450 nm. There is.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, and to provide a hologram recording material that is chemically more stable than the above-mentioned recording materials, has higher sensitivity to Ar laser light, and has excellent moisture resistance, heat resistance, and light resistance. It is about providing.

[Means for solving problems]

As a result of research aimed at providing a photosensitive material for hologram recording that has sensitivity, resolution, heat and humidity resistance, and light resistance that are sensitive to long wavelengths, the applicant found that A cyclic cis-α that can release radicals by photoexcitation as a crosslinking agent in a polymer having an aromatic ring or a heterocycle in which possible reaction sites exist.
- Discovered that the desired light-sensitive material can be provided by using a dicarbonyl compound and a sensitizer together,
A hologram recording material characterized by containing a polymer containing a vinyl carbazole ring, a cyclic cis-α-dicarbonyl compound that generates radicals upon irradiation with light, and a dye as a photosensitizer or spectral sensitizer for thioflavins. was proposed in Japanese Patent Application Laid-Open No. 58-122532 (Japanese Patent Application No. 57-5695).

As a result of further research, the present inventors found that thioflavin T having the following chemical formula unexpectedly acts as a crosslinking agent for a polymer containing a carbazole ring in the absence of the cyclic cis-α-dicarbonyl compound. The present invention has been completed. That is, according to the present invention, the above object is achieved by a photosensitive material for hologram recording, which is formed using a polymer containing a carbazole ring as a main ingredient and using thioflavin T as a crosslinking agent.

As a result of further studies, the present inventor found that sensitivity can be further increased by using thioflavin and iodoform together as crosslinking agents.

[For production]

The hologram recording photosensitive material of the present invention uses a polymer containing a carbazole ring as a main ingredient, and uses thioflavin T as a crosslinking agent. Thioflavin T is known to be used as a dye, but its use as a crosslinking agent for hologram recording photosensitive materials is unknown, and its action is still unknown. Incidentally, Japanese Patent Publication No. 51-31453 discloses the invention of a photoreceptor for forming light scattering patterns and relief patterns having a vinylcarbazole group that utilizes the sensitizing effect of a dye precursor. Containing compounds are used. According to the same invention, a gradual explanation is given that the dye precursor promotes the crosslinking of the polymer containing vinylcarbazole, but even if this explanation is taken into account, the effect of the dye Thioflavin T cannot be inferred. Thioflavin T used in the present invention acts as an optical crosslinking agent in the polymer, improves the chemical stability of the photosensitive material, and provides a photosensitive material with excellent moisture resistance, heat resistance, and light resistance. In addition, thioflavin T
Higher sensitivity can be achieved by using thioflavin T and iodoform together as a crosslinking agent. For example, when thioflavin T and acridine orange, which functions as a crosslinking agent, are used together, Sensitivity was worse than when used alone.

〔Example〕

The carbazole ring-containing polymer used in the present invention may be substituted with halogen, alkyl, amino, nitro, thiocyano, etc., or may be a copolymer with other polymers.

The photosensitive material for hologram recording according to the present invention contains the above-mentioned components, that is, a polymer and a crosslinking agent. It can be prepared by dissolving or dispersing it in an appropriate solvent with a seismic intensity, and forming the resulting solution or dispersion into a film as it is, or by coating it on a support such as glass or plastic. In this case, the amount of crosslinking agent used is about 1.0 to 50% by weight, based on the weight of the polymer;
Advantageously, it is preferably between 3 and 30% by weight. Furthermore, if necessary, in addition to the above-mentioned components, it is also possible to appropriately add, for example, a plasticizer, a reducing agent, an antioxidant, and the like.

Hologram recording using the photosensitive material according to the present invention can be performed, for example, with a hologram exposure optical system as shown in FIG. In the case of the illustrated optical system, the laser beam emitted from the laser 1 passes through the shutter 2 and is reflected by the mirror 3.
A hologram is recorded by irradiating the photosensitive plate 9 with the light reflected by the half mirror 4 and passed through the mirror 6 and the collimator lens 7, and the light that passed through the half mirror 4 and passed through the mirror 5 and the collimator lens 8. be able to.

The present invention will be further explained below using experimental examples.

Example 1 Poly-N-vinylcarbazole Log (Menga Fragrance Industry, Tubicol T-210) Thioflavin T
1g methanol
1.8ml chloroform
120g photosensitive liquid with the above composition 70 x 70 x 3
The film thickness after drying is 1.5 on am reinforced acrylic substrate.
Coated in the dark using the spin code method so that the thickness of
A photosensitive plate for hologram recording was manufactured.

This photosensitive plate was used to record a hologram using a 488 nm Ar laser using the hologram production optical system shown in Figure 3, immersed in ethanol for 10 minutes, air-dried, and then left in toluene vapor for a certain period of time. A hologram was created by immersing it in n-pentane.

FIG. 1 shows the relationship between the exposure amount and the diffraction efficiency when holograms were created by varying the exposure amount. Exposure amount 360mJ/crl
We were able to create a hologram with a diffraction efficiency of 78%.

To check the moisture resistance of this hologram, 50℃, 95%
Although it was left in a constant temperature and humidity chamber of R, H, no decrease in diffraction efficiency was observed even after 10 days. Further, in order to examine the heat resistance, a heat shock test of 5 cycles of 1 hour at 30° C. and 1 hour at 80° C. was conducted, but no decrease in diffraction efficiency was observed in this case either.

Example 2.3 Table 1 shows the exposure amount required to obtain a diffraction efficiency of 70% when the weight ratio of Thioflavin T was changed in Example 1. As shown in Table 1, when the weight ratio is 20.0wt%,
The required exposure amount was 200 mJ/ctA.

Table 1 Relationship between concentration and exposure Example 4 Poly-N-vinylcarbazole 10g (Mento Fragrance Industry, Tubicol T-210) Thioflavin T
1g iodoform
1g methanol 1.
8ml chloroform 120g
A photosensitive liquid having the above composition was coated on a reinforced acrylic substrate of 70 x 70 x 3 mm in a dark place by a spin code method so that the film thickness after drying was 1.5 μm, thereby producing a photosensitive plate for hologram recording.

This photosensitive plate was used to record a hologram using 488 nm Ar laser light using the hologram production optical system shown in Figure 3, immersed in ethanol for 10 minutes, air-dried, and then left in toluene vapor for a certain period of time. A hologram was created by immersing it in n-pentane.

FIG. 2 shows the relationship between the exposure amount and the diffraction efficiency when holograms were created by changing the exposure amount. A hologram with a diffraction efficiency of 78% was created with an exposure dose of 40 mJ/cut.

What about this hologram? 50℃ to complete the W property three times.
,95%R,)! I left it in a constant temperature and humidity chamber for 10 minutes.
No decrease in diffraction efficiency was observed even after several days. Further, in order to examine the heat resistance, a heat shock test was conducted for 5 cycles of 1 hour at 30° C. and 1 hour at 80° C., but no decrease in diffraction efficiency was observed in this case either.

In order to show the increased sensitivity achieved by using a crosslinking agent in combination, Table 2 shows the exposure amount required to obtain a diffraction efficiency of 70% when Thioflavin T and iodoform are used together and when each is used alone. .

It can be seen that by using a crosslinking agent in combination in this way, the sensitivity could be increased by more than 10 times as compared to the case where only Thioflavin T, which is a highly sensitive crosslinking agent, was used.

Table 2 Relationship between crosslinking agent and required exposure amount In Examples 1 and 4 above, hologram recording was performed using Ar laser light, and the material was immersed in ethanol for 10 minutes, air-dried, and then developed and fixed. The photosensitivity to laser light increases with the weight ratio of the crosslinking agent added. However, when the weight ratio of the crosslinking agent to poly-N-vinyl powder exceeds 8%, the development and fixing process frequently causes small cracks and the crosslinking agent. This is to eliminate the problem of the occurrence of crystalline regions that are thought to be precipitated. After exposing a hologram to a photoresist film for hologram recording, which is formed using poly-N-vinyl chloride as a main ingredient and using thioflavin T or thioflavin T and iodoform as a cross-linking agent, the poly-N - This can be achieved by removing unnecessary crosslinking agents from the photosensitive film using a solvent in which vinylcarbazole is insoluble and thioflavin T or thioflavin T and iodoform are soluble.

In addition to ethanol, acetone, 2-butanone, isopropanol, methyl acetate,
Ethyl acetate or a mixture thereof can also be used.

Example 5 Poly-N-vinylcarbazole 10g (Menga Fragrance Industry, Tubicol T-210) Thioflavin T
1g iodoform
1g methanol
1.8ml chloroform 12
A photosensitive film for hologram recording was prepared by applying 0 g of a photosensitive liquid having the above composition onto a 70 x 70 x l + u glass substrate by a spin code method so that the film thickness after drying was 1.5 μm.

Two-beam interference optical system T for hologram exposure on this photosensitive plate:
Hologram exposure using Ar laser 488n and m light (
After exposure ('120 mJ/cIiI), it was immersed in acetone for 2 minutes. The photoresist film had a yellow color before being immersed in acetone, but by immersing it in acetone, thioflavin T and iodoform in the film were dissolved in acetone, and when the photoresist film was pulled up from the acetone, it became colorless and transparent. Met.

After this photosensitive film was air-dried, it was left in toluene vapor for a certain period of time, and then immediately immersed in n-pentane for development and fixation, thereby creating a hologram.

As a result, a high-quality hologram without cracks or crosslinking agent precipitation was obtained, and the maximum diffraction efficiency of the hologram was 78%.

For comparison, when the hologram was developed and fixed without removing the crosslinking agent after exposure, fine cracks were generated on one side of the hologram, and a crystalline region where the crosslinking agent was thought to have precipitated was generated.

〔Effect of the invention〕

As explained in detail above, according to the present invention, holographic recording is chemically stable and more sensitive to Ar laser light than conventional recording materials, and has high moisture resistance, heat resistance, and light resistance. materials can be obtained. Furthermore, high-quality holograms without cracks or crosslinking agent precipitation can be produced using highly sensitive photosensitive materials.

[Brief explanation of drawings]

FIGS. 1 and 2 are diagrams showing the relationship between exposure amount and diffraction efficiency in hologram creation. FIG. 3 is a block diagram of a two-beam exposure device for producing holograms. In Figure 1, 1 is a laser, 2 is a laser, 3°5.6
is a mirror, 4 is a half mirror 17, 8 is a collimator, 9
indicates a photosensitive plate.

Claims (1)

[Claims] 1. A photosensitive material for recording an interference fringe pattern caused by interference between a reference beam and an information beam from a laser light source, the main ingredient being a polymer containing a carbazole ring, and containing thioflavin T.
A photosensitive material for hologram recording, characterized in that it comprises as a crosslinking agent. 2. A photosensitive material for recording an interference fringe pattern caused by the interference of reference light from a laser light source with information light is characterized by comprising a polymer containing a carbazole ring as a main ingredient and thioflavin T and iodoform as crosslinking agents. Photosensitive material for hologram recording. 3. After performing hologram exposure on a hologram recording photosensitive film made of a polymer having a carbazole ring and a crosslinking agent,
A method for manufacturing a hologram, which comprises removing unnecessary crosslinking agent from the photoresist film before a development process using a solvent in which the polymer is insoluble and the crosslinking agent is soluble. 4. The method for producing a hologram according to item 3, wherein the polymer having a carbazole ring is poly-N-vinylcarbazole, and the crosslinking agent is thioflavin T or thioflavin T and a halogen-containing compound. 5. Removal treatment is ethanol, acetone, 2-butanone,
4. The method for producing a hologram according to claim 3, wherein the photosensitive film is immersed in isopropanol, methyl acetate, ethyl acetate, or a mixture thereof.