JPS6161894A - Optical recording material - Google Patents

Abstract

PURPOSE:To ensure easy production, unnecessary of development and rewritability, by constituting an optical recording material of a clathrate compound of a silver halide and zeolite. CONSTITUTION:The optical recording material is constituted of a clathrate compound of silver halide and zeolite. The silver halide is basically not limited, and may be, for example, at least one of AgCl, AgBr and AgI. Zeolite may be, for example, of the Na mordenite type, the NaX type or the BaY type. The amount of the silver halide used for forming the clathrate compound with zeolite is preferably not more than 30wt%, since an amount of more than 30wt% causes the clathrate compound to be formed with difficulty. By use of the clathrate compound, a photosensitive recording material which enables repeated rewriting can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to optical recording materials, and more particularly to rewritable photophobic recording materials containing silver halide.

[Invented dish]

Photochromic glass is an example of a replaceable five-light material containing halogenated fN. This glass is SiO
2. (A button and a halogen are introduced into a glass matrix mainly composed of t 20 s, and heat treated at a temperature of 600 to 70°C for several tens of minutes to several hours to precipitate fine silver halide particles that will become a photoreceptor. It is something that

Photochromic glass can be used as a rewritable recording material because it turns black when exposed to ultraviolet light and visible light, and rapidly fades when heated. However, it has the disadvantage of complicating the manufacturing process because it requires introducing additives such as Cu and optimizing silver and halogens, which tend to scatter during glass manufacturing.
The disadvantage was that the color faded even at room temperature, and records were easily lost.

[Summary of the invention]

The present invention has been made in view of the above points, and it is an object of the present invention to provide a six-optical recording material that is easy to manufacture, does not require development processing, and is refillable.

Therefore, the optical recording material according to the present invention is characterized in that it consists of an inclusion compound of silver halide and zeolite.

Since the optical recording material according to the present invention includes silver halide in zeolite, it has the advantage of improved photosensitivity and good reversibility.

[Detailed description of the invention]

The present invention consists of a clathrate compound of silver halide and zeolite, and such a clathrate compound can be obtained by firing a mixture of silver halide and zeolite.

The silver halide used in the present invention is basically not limited, and for example, ΔgCL AgBr, Agl
It is possible to use one or more of the following.

Zeolites include, for example, Na mordenite type (standard composition: Nas81, hereinafter abbreviated as NaF), NaX type (standard composition: Na
66Ala6Si10603B4), NaY type (
Standard composition: Nag6 AI! ,6 S1+36031
Any of the zeolites listed in 14) can be used.

It is preferable that 30wL% or less of silver halide which forms an clathrate with the zeolite is added. 30wL%
This is because if it exceeds this, it becomes difficult to form an clathrate compound.

More specifically, when NaM is used as the zeolite, the composition ratio of silver halide is 30-t% or less with respect to Na1l, and when NaX is used as the zeolite, the composition ratio of silver halide is approximately 15-t% relative to Na1L. % or less, when NaY is used as zeolite, 30-L with respect to NaY
% or less of halogenation is preferred.

The photosensitivity of an optical recording material is approximately proportional to the silver halide content, but if the composition exceeds the above, there is a strong possibility that silver halide will precipitate alone.

The firing temperature of the silver halide and zeolite mixture must not exceed the melting temperature of the silver halide.

For this reason, for example, when AgCl or AgBr is used as silver halide, the
When Agl is used, a temperature of about 500°C is appropriate.

In order to generate the above-mentioned clathrate compound, at the above-mentioned temperature, the formula 101) i! Requires intermediate firing. After heating, precipitation of silver halide can be prevented by rapidly cooling to room temperature.

In this way'! The clathrate compound A is AgC1
It is obtained as a white powder when using 8gBr, pale yellow when using 8gBr, and yellow when using Agl.

The optical recording material according to the present invention produced in this way can be used both in a moisture-adsorbed state and in a dry state. Let stand for ~3 hours before use. Also,
Dry! When using it in a room, it is necessary to keep it out of moisture by inserting it into a glass holder, etc.

Next, the characteristics of the optical recording material according to the present invention will be explained.

As a result of examining the photosensitivity of the above-mentioned clathrate compound, it was found that it turns black when exposed to light, and then returns to its original state and fades when heated. It is also possible to reverse the darkening caused by light irradiation and fading caused by heating. Therefore, by using these clathrate compounds, a repeatedly rewritable photosensitive recording material can be achieved.

These zeolite clathrate compounds of silver halide can be produced by mixing silver halide and zeolite and calcining the mixture.
) Although it can be easily produced, a diffraction peak of silver halide is found in the X89 times 4 loaf peak in a mixed state of silver halide and zeolite, but the X-ray diffraction peak of the photosensitive material produced by firing it is found. No diffraction peak of silver halide is observed in , which indicates that the optical recording material according to the present invention is not just a mixture of silver halide and zeolite, but is an inclusion compound.

The optical recording material according to the present invention has moisture adsorption and
) and dry light ↓ show different photosensitivity, but in either case, it can be used as a photosensitive material that can be repeatedly rewritten.

■ Photosensitive characteristics when moisture is adsorbed When moisture is adsorbed, near-ultraviolet and visible light from water pressure lamps, halogen lamps, white R() bulbs, fluorescent lamps, etc.
! By emitting 6 rays, the anti-Ij ratio in the visible region and near-infrared region is reduced, and recording becomes possible.

The recording sensitivity of this clathrate compound is higher than that of silver halide alone. The recording can be read out by using a weak light source of visible light or a light source with a wavelength longer than the upper sensitivity wavelength of the material and detecting the difference in reflectance.

After recording, the reflection spectral characteristics returned to the state before the light irradiation by heat treatment at a temperature of 400 to 450°C for 30 minutes, and as described in 1.
ヱ is erased. If moisture is adsorbed again, the state before recording can be restored and recording and erasing can be performed repeatedly.

This optical recording material retains records for several weeks or more at room temperature.

■ Photosensitive properties when dried When the optical recording material of the present invention is dried, it has a JPo
Not sensitive to mercury lamp light, halogen lamp light, or indoor light. On the other hand, it is exposed to laser light having a back density of several tens of W/C111 or more, and a black spot is formed, allowing recording. That is, there is a dark value of degree + W/ant. This threshold q! The l property brings the following benefits during optical recording.

11) Improving the S/N ratio of optical recording, (2)
After recording on the optical recording material according to the present invention using a laser, the recording does not deteriorate even when handled under daylight. (3) By utilizing the dark value characteristic, when the optical Baku value exceeds the dark value, You can selectively only

Recording can be read out by using visible light having a density of several tens of W/cJ or less and detecting the difference in reflectance.

Recordings can be erased by heat treatment at a temperature of 400 to 450° C. for 30 minutes, and then recording and erasing can be repeated.

Records remain stable at room temperature for several weeks or more.

The properties of the optical recording material according to the present invention described in sections ■ and ■ above, such as rewritability, sensitivity increase effect (when absorbing moisture), and dark value properties (when dry), cannot be observed with silver halide alone. This is a property that can only be obtained by inclusion in zeolite.

Examples will be described below.

Example 1 A (H[) was selected as the silver halide and Na group was selected as the zeolite. 8 g I O (26 g) was mixed with NaM Ig and calcined at 500° C. for 150 hours to obtain an clathrate compound.

The photosensitivity properties of this clathrate compound are shown in FIGS. 1 and 2.

■ Photosensitivity characteristics when moisture is absorbed
It is shown in curve 1 in the figure. Also, the reaction when absorbing water of 8gl-NaM! When this photosensitive material whose IJ spectral characteristics are shown by curve 2 in FIG. 2 is irradiated with 25 J/- of light with a wavelength of 360 nm, the reflectance decreases and changes as shown by curve 3 in FIG. The reflectance at a wavelength of 500 nm is reduced by 44%.

On the other hand, in the case of Agl alone, 500
The drop in reflectance in nm was 35.

8CI-'N a? I has an ACl content of 20w
Although the L% is low (it can be seen that the sensitivity is higher than that of Agl i0 Germany).

After irradiation with light, if the film is heated at 450°C for 30 minutes, the reflection spectral characteristics become as shown in 1 in Fig. 1, and the record is erased. It is also possible to repeat the cycle of moisture adsorption, exposure to light, and erasing.

Similar properties are found not only in water adsorption, but also in acetone, C52
It can be burned by the adsorption of a solvent such as chlorine.

(2) Photosensitive properties upon drying Acl-NaM which does not adsorb moisture can be obtained by heating the synthesized 8gl-NaM at 500°C for 30 minutes and then cooling it in dry air or nitrogen. We used low-melting point glass and highly heat-resistant polyimide resin to completely eliminate moisture! A photosensitive recording medium was prepared by adsorbing the material onto a glass disk using a vacuum cleaner. This photosensitive medium is 2 from the dark value characteristic of Agl-NaM.
It is not sensitive to 00W berogen lamp light or 250W mercury lamp light.

Recording was performed on this photosensitive medium using an optical recording system using an argon laser as shown in FIG.

This optical recording system consists of an argon laser 4, a prism 5, a lens 6, a recording medium rotation system 7, an optical head (lens prism) moving mechanism 10, and an optical recording medium 8, and focuses the laser beam onto the medium using the lens. It is for recording.

When irradiating with an argon laser at a density of 55-/- or less, the medium does not change at all even if irradiated for several minutes or more, and no recording is performed. However, when irradiation is performed at a density of 55 W/ci or higher, the irradiated area becomes black and a spot is formed, allowing recording to be performed.

Figure 4 shows the argon laser beam at 110 W/LIJIt.
The figure shows a spot formed when irradiated for 1.6 seconds at a background density of . With a spot diameter of approximately 130 μm, a spot approximately equal to the beam i can be obtained. It's against the spot! 1.J ratio is low, and optical J/L can be determined. After recording with a laser, it was heated at 450°C for 3
The recording spot is erased by heating for 0 minutes, and recording and reproduction can be repeated. Above AgI-N
We have detailed the photosensitive properties of atl, and the increase in arbitrariness due to the formation of clathrate compounds is most remarkable in Ag1.
It becomes smaller than iB of AgBr and A3Cl. As for theorides, AgCl and NaY have almost the same effect, and Naχ has a low sensitivity to the clathrate compound that is removed due to the small amount of inclusion of silver halide.

〔Effect of the invention〕

As explained above, the silver halide zeolite clathrate compound photosensitive material has improved photosensitive properties due to the encapsulation effect.
Good reversibility is obtained.

Therefore, the optical recording material according to the present invention has the following properties: 1) Records can be easily erased by heating, and recording and erasing can be repeated. 2) Development is not required, and records remain stable for several weeks or more at room temperature. 3) No special measures are required in the manufacturing process; 4) When water is absorbed, the degree of anger is higher than when silver halide is used alone; 5) When drying, the dark value of the writing laser beam is reduced. It has the following advantages:

[Brief explanation of the drawing]

Figure 1 is a graph showing the reflection spectral characteristics of Ag1-Na1l when it is dried, Figure 2 is a graph showing the powder diffuse reflection spectral characteristics of Agl-NaF when it absorbs water, and Figure 3
The figure does not show a complete diagram of the structure of an optical recording system for an optical recording medium on a disk to which Ag1-Na1l is attached. 1101+/c on the optical recording medium on the disc attached due to the death! Optics of a spot formed when irradiated with argon laser light of Baku-density II for 1.6 seconds! ? ! ! This is a microscopic photograph (spot diameter is approximately 130 μm). 1...Powder diffuse reflection spectral characteristics of Agl-NaM when dry, 2...Powder diffuse reflection spectral characteristics of ∆gl-NaM when water is absorbed, 3...Moisture adsorption step wavelength 350 nm for Ag1-NaF Reflection spectral characteristics after irradiation with 25 J/ca of light, 4...Argon laser, 5...Prism, 6...
... Lens, 7 ... Recording medium rotation system, 8 ... Disc-shaped optical recording medium, 9 ... Laser beam, 10.
...Optical head (prism lens) movement mechanism.

Claims (1)

[Claims] (1) An optical recording medium comprising an inclusion compound of silver halide and zeolite.