JPS59151346A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To inhibit the photo-deterioration of an optical information recording medium due to oxygen by placing thin films of org. coloring matter on transparent substrates opposite to each other with a space in-between, providing a tightly sealed structure, and filling the space with an inert gas and an oxygen absorber. CONSTITUTION:A thin film 2 of org. coloring matter is formed on one side of each of transparent substrates 1 as a recording layer, and the films 2, 2 are placed opposite to each other with spacers 3, 3 in-between. The space 4 among the two substrates 1, 1 and the spacers 3, 3 is filled with an inert gas and an oxygen absorber. An underlayer of SiO2 or the like may be formed between each of the substrates 1 and each of the films 2 to reduce the gas permeability and to improve the shelf stability furthermore. The inert gas is N2, Ar, CO2 or Ne, and fine powder of iron, Mg, Ni, Cu, CuO, Zn, Pb, Sn, Al, Ag, Cd or Au is used as the oxygen absorber.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a novel structure of an optical information recording medium having an organic dye thin film. More specifically, the present invention relates to an optical information recording medium used in a method of directly recording with a laser beam and reproducing information by changing reflected light.

Prior Art Optical recording media using thin films of organic dyes are characterized by ease of manufacture and excellent recording properties, but they have the disadvantage of being somewhat less stable against light, resulting in fading when exposed to light for a long period of time. be. This is because the dye is photoexcited and reacts with oxygen. As a countermeasure against this problem, a so-called sand inch method has been proposed in which dye thin films are arranged facing each other, but there is a problem in that oxygen enters the space through the substrate and the adhesive part, causing deterioration of the information recording medium.

Purpose The present invention was made in view of the above problems, and
The purpose of this is to make the inert gas and oxygen absorbent fully present in the closed space in order to completely suppress photodeterioration caused by oxygen.

Structure In order to achieve the above-mentioned purpose, the optical information H1 of the present invention,
, the recording medium has a sealed structure in which two optical information recording media each having an organic dye thin film on a transparent substrate face each other across the entire space of each dye thin film surface, and an inert gas and It is characterized by the presence of an acid accumulation absorbent.

Examples of inert gases useful in the present invention include N
2, Ar%002 and Ne, among which nitrogen is preferred because it is economical. As an oxygen absorbent, for example, fine iron powder, J%N1, OutOuO, Zn%
Pb s Eln % At , A, E % Cd
* Fine powder such as Au can be used.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view showing the basic structure of the optical information recording medium of the present invention. The two transparent substrates 1.1 are made of transparent material such as glass, acrylic, polycarbonate, etc. An organic color thread film 2 is provided as a recording layer on the next surface of the plate 1, and the thin film 2.2 is spaced 14'1 apart with a spacer 3.6 interposed therebetween. 2 boards 1
．． The sky 1”J is quadrupled by 1 and Sube-za 6, 3
] 4 is filled with inert gas and oxygen absorbent. Although not shown, a sublayer such as SIO may be provided between the substrate 1 and the organic colored thin film 2 to reduce air permeability and further improve storage stability. It is also possible to provide a protective layer on top of the pigmented membrane 2.

FIG. 2 is a sectional view showing another structure of the optical information recording medium of the present invention. As shown in the figure, if an oxygen absorber 5 (for example, fine iron powder) is completely enclosed in a part of the spacer 6 on the inner circumference of the information recording medium 1, oxygen that enters through the substrate or adhesive part can be captured. This improves light resistance.

At this time, in order to prevent the oxygen absorbent from scattering, it is necessary to bring the oxygen absorbent into full contact with the space 4 through the membrane filter 6. Furthermore, for the same purpose, an oxygen absorbent can be enclosed in a part of the spacer 6 on the outer circumference of the information recording medium 1 or on both the inner and outer circumferences.

EXAMPLES The present invention will be further illustrated by examples below, but the present invention is not limited thereto.

Comparative Example 1 1-Methyl-2-(7-(1-methyl-6,6-dimethyl-2-indolinylidene), 1 on an acrylic substrate
．． 3.5-Hebutatrienyl) -3,3-dimethyl-indolium-ξ-chlorate-(i7j4 cloth was used to make a recording layer with a thickness of 500 A. Two information recording media were placed facing each other in a nitrogen stream, and a spacer was inserted. Sealed through.

When a light resistance life test was conducted, a change occurred after about 270 hours.

5- The light resistance life of a recording medium is expressed as the value when stored outdoors in a place exposed to 1/100 of the irradiation light, and is the number of years it takes for the optical density to decrease to 80% of its initial value. did. For the light resistance test, an accelerated test method was used in which tungsten light of 54,000 lux was irradiated at ff140±5°C.

Comparative Example 2 eiO was deposited on an all-acrylic substrate to a thickness of 2000X, and further recorded on it in the same manner as Comparative Example 1)fiIfr:
The needles were set up and closely punctured in a nitrogen stream.

When a sidelight test was conducted, a change occurred after about 360 hours.

Comparative example 6 The information recording medium prepared in Comparative Example 1 was sealed in air.

When it reached the end of its light resistance life, a change occurred after about 42 hours.

6- Example 1 The information recorder prepared in Comparative Example 1 was sealed in a ♀ plain air flow together with fine iron powder having an average particle size of 6 μm, which had been reduced in advance and kept for 10 days. The iron powder was separated by a membrane filter with a pore size of 02 μm to prevent it from coming into direct contact with the recording layer.

When the light exchange life of the thus obtained recording medium was suppressed, no change occurred even after approximately 480 hours had elapsed.

Actual sister example 2 The information recording medium prepared in comparative example 1 was
It was sealed in the same manner as in Example 1 in an argon stream together with g powder.

When the blood/light life of the thus obtained recording medium was determined, no change occurred even after approximately 540 hours had elapsed.

Example 5 Embrun filter, 7...center shaft hole.

A similar test was conducted by replacing the iron fine powder in Example 1 with N1 fine powder. When the sidelight life was reached, no change occurred even after about 480 hours.

Effects The optical information recording medium of the present invention configured as described above can suppress photodeterioration caused by oxygen. For example, when a closed space is filled with only an inert gas, the light suppression life is improved by about 6 times compared to that in air, but in the presence of an oxygen absorber as in the present invention, the light suppression life is further extended by more than two times.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the entire basic structure of the optical information recording medium of the present invention, and FIG. 2 is a cross-sectional view showing another structure of the optical information recording medium of the present invention. DESCRIPTION OF SYMBOLS 1... Transparent substrate, 2... Organic dye thin film, 3... Spacer, 4... Closed space, 5... Oxygen absorber, 6...
...Me 8- Patent applicant Rico Co., Ltd. - 9-

Claims (1)

[Claims] Two optical information recording media each having an organic dye thin film on a transparent substrate are made to face each other across the entire surface of each dye thin film to form a sealed structure, and an inert gas and an oxygen absorber are completely present in the thus formed sealed space. An optical information recording medium characterized by: