JPH09218484A - Information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out information recording of high quality with high contrast of the recorded information and no graininess (roughness) by incorporating a specified compd. into a specified liquid crystal compsn. SOLUTION: This information recording medium has an information recording layer comprising a liquid crystal phase and a resin phase on an electrode layer. The information recording layer consists of a UV-curing resin and a fluorine- surfactant. The liquid crystal phase contains at least a compd. expressed by formula I of compds. expressed by formula I and formula II in a liquid crystal compsn. comprising at least either 4-alkyl-4-cyanobiphenyl or 4-alkoxy-4'- cyanobiphenyl. In formula I, (m) is an integer 1 to 18, (p) is an integer 1 to 18, and in formula II, (n) is an integer 1 to 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium capable of obtaining electrostatic information recorded by an exposure recording method when a voltage is applied as visible information, and particularly, there is no noise due to graininess (roughness) of recorded information. The present invention relates to an information recording medium capable of recording high quality information.

[0002]

2. Description of the Related Art An optical sensor in which a photoconductive layer is laminated on an electrode and an information recording medium in which an information recording layer made of polymer dispersed liquid crystal is laminated on the electrode are arranged facing each other on the optical axis, and both electrodes are arranged. An information recording / reproducing method in which exposure is performed while applying a voltage between layers, information is recorded by orienting a liquid crystal layer by an electric field formed by a photosensor, and visible information is reproduced by transmitted light or reflected light when reproducing information Japanese Patent Application Laid-Open No. 5-270140, Japanese Patent Application Laid-Open No. 5-165005, Japanese Patent Application Laid-Open No. 6-130347, and Japanese Patent Application No. 5-266646. This information recording / reproducing method can reproduce recorded information without using a polarizing plate.

The applicant of the present invention has a structure in which a liquid crystal phase and an ultraviolet curable resin phase are dispersed inside the information recording layer by using an ultraviolet curable resin as a resin forming the information recording layer, and Since the surface of the information recording layer is formed only from the resin layer, the phenomenon of liquid crystal seepage does not occur,
It was found that it is possible to perform noise-free recording in information recording using an optical sensor, and it is possible to directly form an electrode layer such as an ITO film on a resin layer by a sputtering method or the like, and filed a prior application. However, in such an information recording medium, smectic liquid crystals are preferably used as the liquid crystal substance from the viewpoint of recording property, but the recording has low contrast and also graininess (roughness) occurs, When reproducing information, noise may occur and the quality of recorded information may deteriorate.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an information recording medium using an ultraviolet-curable resin-dispersed liquid crystal and an improvement thereof, wherein recorded information has high contrast and is free of graininess (roughness). It is an object to provide an information recording medium capable of recording high quality information.

[0005]

A first information recording medium of the present invention has an information recording layer composed of a liquid crystal phase and a resin phase on an electrode layer, and the information recording layer is an ultraviolet curable resin and a fluorine-based resin. In an information recording medium containing a surfactant, the liquid crystal composition in which the liquid crystal phase is at least one of 4-alkyl-4-cyanobiphenyl and 4-alkoxy-4′-cyanobiphenyl is added to the above formula 1 Among the compounds represented by 1 and 2, the information recording medium contains at least the compound represented by the general formula 1. Also, the electrode layer,
In the information recording medium, a photoconductive layer, an information recording layer, and an electrode layer are sequentially provided, and at least one of the electrode layers is transparent, and the information recording layer is composed of an ultraviolet curable resin and a fluorosurfactant. The liquid crystal phase is 4-alkyl-4
-Cyanobiphenyl and 4-alkoxy-4'-cyanobiphenyl are contained in a liquid crystal composition containing at least a compound represented by the general formula 1 among the compounds represented by the general formulas 1 and 2. This is an information recording medium.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining a cross section of a first information recording medium of the present invention. The information recording medium 3 has an electrode layer 13 used for recording information on a substrate 15 and an information recording layer 11 on the electrode layer. Information recording layer 1
1 is composed of a liquid crystal phase and a resin phase. In particular,
The present invention provides, as a liquid crystal composition, a liquid crystal composition comprising at least one of 4-alkyl-4′-cyanobiphenyl and 4-alkoxy-4′-cyanobiphenyl,
It is considered that the thermal or structural stability of the liquid crystal phase is increased, and the light scattering degree is improved by the tricyclic compound having a large refractive index anisotropy and the microscopic phase separation between the hydrocarbon moiety and the fluorine-substituted moiety. By using a liquid crystal composition to which at least one of the fluorine compounds considered to be added is used, an information recording medium with high contrast and high quality can be obtained.

The 4-alkyl-4'-cyanobiphenyl and 4-alkoxy-4'-cyanobiphenyl used in the present invention can achieve the purpose even if only one kind is used, but prevent crystallization in an information recording medium. Therefore, in order to obtain a liquid crystal composition having a low melting point, it is better to mix two or more kinds. It is better to use 4-alkyl-4'-cyanobiphenyl in terms of lowering the melting point, but it is better to use 4-alkoxy-4'-cyanobiphenyl in terms of improving the stability of the smectic phase. The compound may be appropriately selected according to the purpose. However, when the amount of 4-alkyl-4′-cyanobiphenyl or 4-alkoxy-4′-cyanobiphenyl having 11 or more carbon atoms in the alkyl side chain is too large, the nematic phase disappears in the phase transition of the liquid crystal, and the granularity If (roughness) is generated and the amount of cyanobiphenyl having 8 or less carbon atoms in the alkyl side chain is too large, the temperature range of the nematic phase is widened and the contrast is lowered. The nematic phase does not disappear in the phase transition of the object,
The temperature range of the nematic phase should be below the amount that does not spread.

The addition amount of the compound of the general formula 1 used in the present invention should be 20% or less from the viewpoint of not raising the melting point, and 7% or less from the viewpoint of not eliminating the nematic phase of the liquid crystal composition. desirable. In order to improve the contrast, 0.5% or more, preferably 1% or more should be added. Further, the addition amount of the compound of the general formula 2 used in the present invention should be 20% or less in view of not raising the melting point, and 0.1% or more, preferably 1% or more is added to improve the contrast. Should. The compounds of the above-mentioned general formulas 1 and 2 may be added to the biphenyl liquid crystal at the same time, and the compound of the general formula 1 may be added alone to perform information recording with high contrast and improved graininess at the time of information recording. be able to.

Next, as the material for forming the resin phase, an ultraviolet curable resin which is compatible with the liquid crystal at room temperature or by heating in the state of a monomer or an oligomer,
Alternatively, those having a compatibility with a solvent common to the liquid crystal material in a monomer or oligomer state at room temperature or at the time of heating can be mentioned. Examples of such an ultraviolet curable resin include acrylic acid ester, methacrylic acid ester and the like, and in a monomer or oligomer state, for example, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, polypropylene glycol. Diacrylate, isocyanuric acid (ethylene oxide modified) triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetraacrylate, neopentyl glycol diacrylate, hexanediol diacrylate, etc. , Further nonylphenol modified acrylate, N-vinyl-2-pyrrolidone, 2-hydroxy-3-phenoxy B monofunctional monomer or oligomer such as pills acrylate. Further, as the ultraviolet curable resin, those represented by the following general formulas 3 and 4 can also be used.

[0010]

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Next, the common solvent for the liquid crystal and the UV-curable resin monomer or oligomer is a solvent having a relative evaporation rate of less than 2 with respect to -n-butyl acetate. It is necessary that the solvent is a common solvent for both the agent and the fluorosurfactant. The "solvent having a relative evaporation rate with respect to -n-butyl acetate of less than 2" is described, for example, in Yuji Harazaki, "Easy-to-understand coating technology", pages 217 to 221, published by Riko Shuppansha. It is volatile at a constant temperature and R defined by evaporation rate (R) = (time required for evaporation of n-butyl acetate-n-butyl acetate) / (time required for evaporation of comparative solvent) is 2 or more. It's a small one.

Solvents that can be used in the present invention include
Xylene (R = 0.76), cyclohexanone (R =
0.32) or the like having a relatively low evaporation rate is preferable.
Examples of the solvent include halogenated hydrocarbon solvents such as chloroform, alcohol derivative solvents such as methyl cellosolve, and ether solvents such as dioxane. In addition, specifically, methyl alcohol,
Ethanol, isopropanol, n-propanol, s
ec-butanol, isobutanol, n-butanol,
Methyl isobutyl carbinol, diisobutyl carbinol, hexylene glycol, acetic acid-sec-butanol, isobutyl acetate (98%), n-butyl acetate, methyl amyl acetate, aluminum acetate (95% isomer mixture), methyl amyl acetate, amyl lactic acid acetate Ethyl, methyl oxitol, ethyl oxitol, isopropyl oxitol, methyl oxitol acetate, ethyl oxytol acetate, butyl oxitol, methyl dioxitol, ethyl dioxitol, butyl dioxitol,
Butyldioxitol acetate, methyl isobutyl ketone, ethyl amyl ketone, methyl cyclohexanone,
Diisobutyl ketone, diacetone alcohol, isophorone, 1,4-dioxane, perchloroethylene, dichloropropane, 2-nitropropane, toluene, Shel
lsolA, White Spirit (LAWS), She
llsolE, ShellsolTD, white spirit (115 ° F flash), ShellsolT, She
llsolAB, Distillate, Solven
t300, ShellsolN, ShellsolR
A, ShellsolK, ShellsolR, Sol
Vent350 etc. can be mentioned.

Examples of the photo-curing agent include 2-hydroxy-2-methyl-1-phenylpropan-1-one (Darocur 1173 manufactured by Ciba-Geigy), 1-hydroxycyclohexyl phenyl ketone (Irgacure 184 manufactured by Ciba-Geigy), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one (Darocur 1116 manufactured by Ciba-Geigy), benzyl dimethyl ketal (Irgacure 65 manufactured by Ciba-Geigy)
1), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (Irgacure 907 manufactured by Ciba-Geigy), 2,4-diethylthioxanthone (Kayacure DETX manufactured by Nippon Kayaku) and p -Ethyl dimethylaminobenzoate (Kayakyu EP manufactured by Nippon Kayaku Co., Ltd.
A), a mixture of isopropylthioxanthone (Kundacure ITX manufactured by Ward Brekinsop Co.) and ethyl p-dimethylaminobenzoate, and the like, and liquid 2-hydroxy-2-methyl-1-phenyl. Propan-1-one is particularly preferable in terms of compatibility.

In addition to the wettability of the information recording layer with respect to the electrode layer, a fluorochemical surfactant is added for the purpose of forming a skin layer made of only resin on the surface of the information recording layer. Examples of such a fluorine-based surfactant include, for example, Sumitomo 3M, Florard FC-430 and Florard FC-431, and N- (n-propyl) -N- (β-acryloxy manufactured by Mitsubishi Materials. Ethyl) -perfluorooctyl sulfonic acid amide (EF-
125M), N- (n-propyl) -N- (β-methacryloxyethyl) -perfluorooctyl sulfonic acid amide (EF-135M), perfluorooctane sulfonic acid (EF-101), perfluorocaprylic acid (EF
-201), N- (n-propyl) -N-perfluorooctanesulfonic acid amide ethanol (EF-12)
1), EF-102, EF-103, EF-104, E
F-105, EF-112, EF-121, EF-12
2A, EF-122B, EF-122C, EF-122
A3, EF-123A, EF-123B, EF-13
2, EF-301, EF-303, EF-305, EF
-306A, EF-501, EF-700, EF-20
1, EF-204, EF-351, EF-352, EF
-801, EF-802, EF-125DS, EF-1
200, EF-L102, EF-L155, EF-L1
74, EF-L215 and the like. Also, 3- (2
-Perfluorohexyl) ethoxy-1,2-dihydroxypropane (MF-100), Nn-propyl-N
-2,3-Dihydroxypropyl perfluorooctylsulfonamide (MF-110), 3- (2-perfluorohexyl) ethoxy-1,2-epoxypropane (MF-120), Nn-propyl-N-2. , 3-epoxypropyl perfluoroactyl sulfonamide (MF-130), perfluorohexyl ethylene (M
F-140), N- [3-trimethoxysilyl) propyl] perfluoroheptylcarboxylic acid amide (MF-1)
50), N- (3-trimethoxysilyl) propyl] perfluoroheptylsulfonamide (MF-160) and the like. The fluorine-based surfactant is used in a proportion of 0.1 to 20% by weight based on the total amount of the liquid crystal and the resin forming material. Further, if necessary, a leveling agent may be added to improve the coating properties of the solution and improve the surface properties after coating.

The content ratio of liquid crystal in the information recording layer is 1
It is 0% to 90% by weight, preferably 40% to 80% by weight. When the content of the liquid crystal is less than 10% by weight, the light transmittance is low even if the liquid crystal phase is aligned by information recording, and when it exceeds 90% by weight, the phenomenon such as seepage of the liquid crystal occurs.
Image unevenness is not preferable. Also, according to the present invention,
The outer surface of the information recording layer can be a skin layer made of a resin layer. As a result, the ratio of liquid crystal is 40% by weight.
The liquid crystal content can be increased to 80% by weight, and an information recording medium with high sensitivity and high contrast can be obtained.

Further, the information recording layer is made opaque due to light scattering when the electric field is not applied by setting the optical refractive index of the oriented liquid crystal phase and the optical refractive index of the resin phase to be substantially the same, and the electric field is When applied, the liquid crystal phase is oriented, and the information recording portion can be made transparent, a polarizing plate is not required for reproducing information, and the optical system for reading can be simplified.

Next, as a method of forming the information recording layer, a liquid crystal, at least one of an ultraviolet-curable monomer and an oligomer, a photopolymerization initiator and a surfactant are used and a relative evaporation rate with respect to -n-butyl acetate. Is mixed with a solvent of less than 2 to obtain a mixed solution having a solid content concentration of 10 to 60% by weight. The viscosity is 1 to 500 cP (20 ° C.), preferably 10 to 200 cP (20 ° C.). If the viscosity is low, the coating solution will flow and the film thickness after coating cannot be maintained.
If the viscosity is high, leveling becomes difficult. Further, the liquid crystal is heated to a temperature higher than the temperature at which the liquid crystal retains an isotropic phase, preferably 10 ° C. higher than the isotropic phase transition point to dissolve the liquid crystal,
The mixed solution is applied onto the electrode at room temperature with a uniform film thickness by a coating method such as a spin coater, a bar coater, a blade coater, or a roll coater.

Next, the dried coating layer is irradiated with ultraviolet rays using an ultraviolet lamp to be cured. When the coating layer is irradiated with ultraviolet rays, infrared rays are shielded to 20
An information recording layer excellent in phase separation between the liquid crystal phase and the resin phase can be obtained by using ultraviolet rays having a wavelength portion of 0 to 400 nm of 1% or more and irradiating with energy of 0.1 mJ / cm ² or more.

When the information recording layer is formed in this way,
0.01% to 30% of the thickness of the information recording layer on the surface of the information recording layer
%, And a skin layer having a film thickness of
Inside the information recording layer, the primary particle diameter is 0.03 μm to 0.3 μm.
The resin particles are filled with the resin particles and the liquid crystal phase is connected between them. Further, the above general formulas (3) and (4)
When the ultraviolet-curable resin monomer represented by is used, the surface skin layer can have excellent durability. By forming a durable skin layer on the surface of the information recording layer, it is possible to increase the use ratio of the liquid crystal in the information recording layer, and there is no bleeding of the liquid crystal onto the surface of the information recording layer. Can be eliminated, and a high-quality image can be obtained.

If the phase separation between the liquid crystal phase and the resin phase is incomplete in the fine structure inside the information recording layer,
The problem arises that contrast cannot be obtained. Also,
When the phase separation is incomplete, the resistance of the information recording layer itself becomes low, and during the information recording by the action of the electric field by the electrostatic information using the optical sensor, the voltage is effectively applied to the liquid crystal phase in the information recording layer. The LCD drive becomes slower,
There is a problem of lowering sensitivity. In addition, if the phase separation is imperfect, when the UV curable resin-forming material is irradiated by an ultraviolet lamp containing infrared rays, it causes non-uniform shrinkage due to unnecessary heating, which is a fatal homogeneous and homogeneous information recording as an information recording medium. It causes a serious problem that it cannot be layered. The average film thickness of the information recording layer is set to 1 μm to 30 μm. If the film thickness is too thick, the operating voltage becomes high, but generally, it is better to make the film thickness thinner for high sensitivity and thicker for higher contrast. In order to achieve excellent sensitivity and contrast ratio, the film thickness is preferably 3 μm to 20 μm, more preferably 5 μm.
The film thickness is preferably 10 to 10 μm. This makes it possible to reduce the operating voltage while maintaining high contrast.

The thickness of the skin layer in the information recording layer can be set to 0.01% to 50% of the thickness of the information recording layer, but if it is too thin, the liquid crystal will seep out.
Noise occurs even when information is recorded by an optical sensor described later. Therefore, the thickness of the skin layer is preferably 0.01% to 30% of the thickness of the information recording layer. Although the detailed reason is not clear, the thickness of the skin layer can be appropriately adjusted by the irradiation amount of ultraviolet rays, addition of a fluorine-based surfactant, and the like. Further, in the information recording medium of the present invention, it is necessary that the thickness of the information recording layer is accurately and uniformly applied. However, by forming the information recording layer by the above method, the thickness of the information recording layer becomes uniform. Has a film thickness of 5μ
In the case of m to 10 μm, the surface roughness Ra is 20 nm.
The contrast can be kept within the range, the contrast is not uneven, and the shading phenomenon does not occur even at the time of recording information.

In general, in the case of this type of polymer-dispersed liquid crystal, it is considered that the resolution depends more on the domain size of the liquid crystal than on the film thickness. When the resin has a large liquid crystal content such as a layer and the resin phase forms into particles, it is necessary to consider the domain size of the liquid crystal much like polymer dispersed liquid crystal with a low normal liquid crystal content. It is possible to easily provide an information recording medium having high contrast ratio and a high contrast ratio. Further, by forming a skin layer on the surface of the information recording layer of the present invention, it is possible to prevent the liquid crystal from seeping out. A resin film, a thermosetting resin film, an ionizing radiation curable resin film such as an ultraviolet curable resin, or the like may be applied or laminated to form.

As a material for forming these resin layers, polyethylene terephthalate, polyethylene, polypropylene, ultraviolet rays and electron-curable resins are particularly preferable. Even when formed into a thin film, a hard coat layer having a high surface hardness is obtained. Therefore, the durability of the information recording medium can be improved. The thickness of the resin layer is 0.1 μm
˜20 μm, preferably 0.1 μm to 5 μm. However, when the film thickness of the resin layer is large, the operating voltage applied to the liquid crystal layer at the time of information recording becomes low. Therefore, when the information recording is performed using the optical sensor described later,
It is necessary to increase the applied voltage. By laminating such a resin layer, it is possible to prevent the phenomenon of liquid crystal seepage from the surface of the information recording layer, increase the hardness of the surface of the information recording layer, and make it durable. Further, since the voltage applied to the information recording layer can be controlled by further changing the film thickness, the recordable exposure intensity range can be adjusted.

The electrode layer needs to be transparent when reading the information recorded in the information recording layer with transmitted light, and the metal thin film conductive film has a specific resistance value of 10 ⁶ Ω · cm or less. Conductive film of inorganic metal oxide such as indium tin oxide, 4
It is an organic conductive film containing a quaternary ammonium. The electrode layer is formed by a method such as vapor deposition, sputtering, CVD, coating, plating, dipping and electrolytic polymerization. The film thickness needs to be changed depending on the electrical characteristics of the material forming the electrodes and the applied voltage at the time of recording information. For example, an ITO film has a thickness of about 10 to 300 nm, and the front surface between the film and the information recording layer. Alternatively, it is formed according to the formation pattern of the information recording layer. When reading information recorded on the information recording layer with reflected light, the electrode layer may be made light-reflective or a light reflecting layer may be laminated on the transparent electrode layer. In order to make the electrode layer light-reflective, a metal electrode such as aluminum may be used. The light reflecting layer may be, for example, a dielectric mirror layer, and may be provided on at least one side or both sides of the electrode layer.

The substrate 15 may be either transparent or opaque depending on whether information is read by transmitted light or reflected light. The information recording medium can have a shape such as a card, a film, a tape, a disk, etc., but the support supports the information recording medium in a strong manner, and when the information recording layer has a supporting property, No need to provide. Flexible plastic film,
Alternatively, a rigid material such as glass, plastic sheet or card is used. When the information recording medium is a flexible film, tape, disc, or card, a flexible plastic film is used, and when strength is required, a rigid sheet, glass, etc. Inorganic materials and the like are used, and those having an arbitrary thickness can be used.

When reproducing information with transmitted light,
If necessary, a layer having an antireflection effect may be laminated on the substrate, the transparent substrate may be adjusted to a film thickness capable of exhibiting the antireflection effect, or the both may be combined to provide the antireflection property.

Next, an information recording method on the first information recording medium of the present invention will be described. Information can be recorded using a method such as an optical sensor, heat, laser, corona charging, etc., but it is preferable to record information using an optical sensor. As the optical sensor, an electrode layer and a photoconductive layer are laminated on a transparent substrate, and as the photoconductive layer, a single layer type having both a charge generating function and a charge transporting function according to information light, There is a laminated type in which a charge generation layer and a charge transport layer are sequentially laminated on an electrode layer. The photoconductive layer generally has a function of generating photocarriers (electrons and holes) at an irradiated portion when irradiated with light, and the carriers can move the layer width. This layer has a remarkable effect when present.

The single-layer type photoconductive layer is formed of an inorganic photoconductive material or an organic photoconductive material. Examples of the inorganic photoconductive substance, Se, Se-Te, ZnO , TiO 2, S
i, CdS, and the like, a vapor deposition method, a sputtering method,
A single layer or a combination thereof is laminated on the electrode layer by a CVD method or the like to have a thickness of 5 to 30 μm, preferably 20 to 30 μm. Further, the inorganic photoconductor as fine particles, organic insulating resin, for example, silicone resin, polyester resin,
It may be dispersed in a binder such as a polycarbonate resin, a styrene-butadiene resin, a styrene resin, or a polyvinyl acetal resin to form a photoconductive layer. In this case, 0.1 to 10 parts by weight of photoconductive fine particles per 1 part by weight of the binder, Preferably, it is dispersed at a ratio of 1 to 5 parts by weight.

Examples of the organic photoconductive substance include high molecular weight photoconductive substances and low molecular weight photoconductive substances dispersed in an insulating binder. Examples of the polymer photoconductive substance include polyvinylcarbazole (PVK), a poly-N-ethylenically unsaturated group containing an ethylenically unsaturated group such as an allyl group or an acryloxyalkyl group instead of the vinyl group in PVK. Examples include substituted carbazoles, poly-N-ethylenically unsaturated group-substituted phenothiazines such as poly-N-acrylphenothiazine and poly-N (β-acryloxy) phenothiazine, and polyvinylpyrene. Among them, poly-N-ethylenically unsaturated group-substituted carbazoles, particularly polyvinylcarbazole are preferably used.

Examples of the low molecular weight photoconductive substance include oxadiazoles substituted with an alkylaminophenyl group, triphenylmethane derivatives, hydrazone derivatives, butadiene derivatives, stilbene derivatives, etc., and low molecular weight photoconductors. 1 part by weight is 0.1 to 5 parts by weight, preferably 0.1 to 1 part by weight of electrically insulating resin such as silicone resin, polyester resin, polycarbonate resin, styrene-butadiene copolymer resin, styrene resin, polyvinyl acetal resin. It may be dispersed in the part to form a film-forming organic photoconductive substance. The film thickness after drying of these organic photoconductive substances is 5 to 30 μm, preferably 10 to 30 μm.
Is laminated on the electrode.

Further, the organic photoconductive layer may be added with a persistent conductivity imparting substance described in JP-A-6-265931, if necessary. The organic photoconductive layer itself has a persistent conductivity, and this persistent conductivity imparting substance is added for the purpose of increasing the persistent conductivity in the organic photoconductive layer. Sustainable conductive material is
The organic photoconductive substance is added in an amount of 0.001 to 1 part by weight, preferably 0.001 to 0.1 part by weight, based on 1 part by weight. If the added amount of the persistent conductivity imparting substance exceeds 1 part by weight, the amplifying function of the photoconductive layer is significantly deteriorated, which is not preferable. In addition, some persistent conductivity-imparting substances do not have spectral sensitivity in visible light, and when utilizing optical information in the visible light region, electron-accepting substances and sensitizing dyes are added so that they have sensitivity in the visible light region. Etc. can be further added. Examples of the electron accepting substance include nitro-substituted benzene, cyano-substituted benzene, halogen-substituted benzene, quinones,
Examples include trinitrofluorenone. Examples of the sensitizing dye include triphenylmethane dye, pyrylium salt dye and xanthene dye. The electron-accepting substance, the sensitizing dye, etc. are 0.001 with respect to 1 part by weight of the organic photoconductive substance.
-1 part by weight, preferably 0.01-1 part by weight. At the same time, if the optical information is in the infrared region, it is advisable to add the same amount of a pigment such as phthalocyanine, a pyrrole-based dye, or a cyanine-based dye, and conversely, there is information light in the ultraviolet region or in a wavelength region below it. In this case, the purpose is achieved by adding the same amount of each wavelength absorbing substance.

Next, the laminated photoconductive layer is formed by sequentially laminating the charge generation layer and the charge transport layer on the electrode, and includes an inorganic material type photoconductive layer and an organic material type photoconductive layer. The charge generation layer in the inorganic material type photoconductive layer is Se-Te, Si doped with sulfur or oxygen, etc., is deposited, sputtered, C
A film having a thickness of 0.05 μm to 1 μm is laminated on the electrode by the VD method or the like. Next, it is preferable that Se, As ₂ Se ₃ , Si, Si doped with methane or the like is laminated on the charge generation layer as a charge transport layer in a similar manner to a film thickness of 10 μm to 50 μm.

Next, the charge generating layer in the organic material type photoconductive layer comprises a charge generating substance and a binder, and as the charge generating substance, there are fluorenone azo pigments, monoazo pigments, bisazo pigments, pyrrole pigments and azurenium. Salt pigments, phthalocyanine pigments, polycyclic aromatic pigments, pyrylium salt pigments, triazo pigments, squarylium salt pigments, perylene pigments, pyranthrone pigments, cyanine pigments, polycyclic quinone pigments, imidazole pigments and the like. Specific examples thereof include the charge-generating substance described in JP-A-6-265931.

Examples of the binder include silicone resin, styrene-butadiene copolymer resin, epoxy resin, acrylic resin, saturated or unsaturated polyester resin, polymethylmethacrylate resin, vinyl chloride resin,
Examples thereof include vinyl acetate resin and vinyl chloride-vinyl acetate copolymer resin, which are formed by dispersing the above charge generating substance in a binder. The charge-generating substance is preferably a fluorenone azo pigment or a bisazo pigment, and the binder is preferably a polyester resin or a vinyl chloride-vinyl acetate copolymer resin. The mixing ratio of the charge generating agent and the binder is 0.1 to 10 parts by weight, preferably 0.1 to 10 parts by weight of the binder per 1 part by weight of the charge generating agent.
It is desirable to use 1 part by weight. The charge generation layer has a thickness of 0.01 to 1 μm, preferably 0.1 to 0.3 μm after drying.

The charge transport layer comprises a charge transport material and a binder. The charge-transporting substance is a substance having a good property of transporting the charges generated in the charge-generating layer, and includes, for example, hydrazone-based, pyrazoline-based, PVK-based carbazole-based, oxazole-based, triazole-based, aromatic amine-based, amine-based,
Triphenylmethane type, butadiene type, stilbene type,
There is a polycyclic aromatic compound system and the like, and it is necessary to use a substance having a good hole transporting property. Preferably, butadiene-based,
Examples thereof include stilbene-based charge transporting substances, and specific examples thereof include the charge transporting substances described in JP-A-6-265931.

As the binder, the same binders as those mentioned above in the charge generating layer can be used, but polyvinyl acetal resin, styrene resin and styrene-butadiene copolymer resin are preferable. The binder is
0.1 to 10 parts by weight with respect to 1 part by weight of the charge transporting substance,
It is desirable to use it in a ratio of preferably 0.1 to 1 part by weight. The thickness of the charge transport layer after drying is 1 to 50 μm, and preferably 10 to 30 μm.

Examples of combinations of these charge generating substances and charge transporting substances include, for example, a combination of a fluorenone azo pigment (charge generating substance) and a stilbene type charge transporting substance, and a bisazo type pigment (charge generating substance). Combinations of butadiene-based and hydrazone-based charge-transporting substances are good. Further, the persistent conductivity imparting substance and the electron accepting substance described in the section of the single-layer photoconductive layer may be added to the charge generation layer and the charge transport layer in the laminated photoconductive layer in the same proportions. However, it is preferably added to the charge generation layer.

When the single-layer photoconductive layer or the laminated photoconductive layer is formed of an organic photoconductive layer, dichloroethane, 1,1,2-trichloroethane, monochlorobenzene, tetrahydrofuran, cyclohexane, or the like is used as a solvent.
A coating solution may be prepared by using dioxane, 1,2,3-trichloropropane, ethyl cellosolve, 1,1,1-trichloroethane, methyl ethyl ketone, chloroform, toluene or the like, and the coating method may be a blade coating method or a dipping method. , Spinner coating method and the like.

An electron-accepting substance, a sensitizing dye, an antioxidant, an ultraviolet absorber, a light stabilizer and the like may be added to the photoconductive layer. The electron accepting substance or the sensitizing dye has a base current regulating action, a base current stabilizing action or a photo-induced current amplifying action. Examples of the electron accepting substance include nitro-substituted benzenes, amino-substituted benzenes, halogen-substituted benzenes, substituted naphthalenes, benzoquinones,
The nitros-substituted fluorenones, chloranil compounds, compounds listed in the charge-transporting substances, and the like, and the sensitizing dyes include triphenylmethane dyes, pyrylium salt dyes, xanthene dyes, leuco dyes, and the like. Electron-accepting substance,
The sensitizing dye is added in an amount of 0.001 to 10 parts by weight, preferably 0.01 to 1 part by weight, based on 1 part by weight of the photoconductive substance. When the amount is less than 0.001 part by weight, no action is exhibited. When the amount is more than 10 parts by weight, the image quality is adversely affected.

The antioxidants include phenolic antioxidants, sulfur antioxidants, and phosphorus antioxidants, and the ultraviolet absorbers include salicylic acid ultraviolet absorbers, benzophenone ultraviolet absorbers, and benzotriazole ultraviolet absorbers. Agents and cyanoacrylate-based UV absorbers, and examples of the light stabilizers include UV stabilizers and hindered amine-based light stabilizers. About antioxidants, ultraviolet absorbers, and light stabilizers, the proportion of 0.001 to 10 parts by weight, preferably 0.01 to 1 part by weight, relative to 1 part by weight of the photoconductive substance, alone or in combination. Is added in. 0.0
If it is less than 01 parts by weight, the effect of addition of these substances cannot be obtained, and if it is more than 10 parts by weight, the image quality is adversely affected. In the case of a laminated photosensor, a charge generation layer,
It can be added to the charge transport layer in the same proportion. Preferably, these substances are added to the charge generation layer.

A photoinduced current amplification layer may be provided between the electrode and the photoconductive layer. The photo-induced current amplification layer controls the action of amplifying the current generated by photo induction in the optical sensor and the charge carrier injection property from the electrode to the photoconductive layer to control the voltage substantially applied to the information recording medium. It has the function of adjusting and uniformizing the charge carrier injection property from the electrode to the photoconductive layer, and reducing the noise and unevenness of the information recorded on the information recording medium. The first effect is effective in improving the recording sensitivity as an optical sensor, the second effect is effective in adjusting the image density of the recorded image, and the third effect is effective in improving the image quality of the recorded image. Target.

This photo-induced current amplification layer is made of, for example, silicone resin, polycarbonate resin, vinyl formal resin, vinyl acetal resin, vinyl butyral resin, styrene resin, styrene-butadiene copolymer resin, epoxy resin, acrylic resin, saturated or unsaturated resin. The saturated polyester resin, the methacrylic resin, the vinyl chloride resin, the vinyl acetate resin, the vinyl chloride-vinyl acetate copolymer resin, or the like is used alone or in combination. further,
Soluble polyamide, phenol resin, polyurethane, polyurea, casein, polypeptide, polyvinyl alcohol, polyvinylpyrrolidone, maleic anhydride polymer, quaternary ammonium salt-containing polymer, cellulose compound, etc. may be used alone or in combination. You can also do it. Particularly, a vinyl formal resin, a vinyl acetal resin, and a vinyl butyral resin are preferable. The thickness of the photo-induced current amplification layer is preferably 0.005 to 5 μm, preferably 0.05 to 0.5 μm, and it can be applied by a method such as dip coating, roll coating or spin coating. If the thickness is less than 0.005 μm, the effect of reducing image noise is lost, and it is 5 μm.
If it is thicker than this, injection of charge carriers from the electrode to the charge generation layer is hindered. Further, the photoinduced current amplification layer may include various electron accepting substances, photoconductive substances, inorganic salts, and
Organic salts are added, and each additive can be used alone or in combination. Examples of the electron accepting substance include substituted benzenes, substituted naphthalenes, substituted and unsubstituted benzoquinones, substituted and unsubstituted naphthoquinones, substituted and unsubstituted anthraquinones, substituted fluorenones, chloranils, substituted quinodimethanes. You can

As the photoconductive substance, the inorganic and organic photoconductive substances of the single layer type and the charge generating substance of the laminated type can be used. As the charge-generating substance, pyrylium dyes, thiapyrylium dyes,
Azurenium dyes, cyanine dyes, cationic dyes such as azurenium dyes, squarylium salt dyes, phthalocyanine pigments, perylene pigments, polycyclic quinone pigments such as pyranthrone pigments, indigo pigments, quinacridone pigments, pyrrole Dyes and pigments such as azo pigments and azo pigments can be used alone or in combination of two or more.

These additives are contained in an amount of 0.001 to 10 parts by weight, preferably 0.0 to 1 part by weight of the binder resin.
5 to 5 parts by weight are added, and each additive may be used alone or in combination of two or more,
Particularly, it is preferable to use a combination of an electron-accepting compound and an organic photoconductive pigment such as a combination of a substituted benzoquinone and an azo pigment, since a large amplifying action can be obtained.

Next, the photo-induced current amplifying action in the optical sensor portion consisting of the electrode and the photoconductive layer will be described. The photo-induced current is the current value of the light-irradiated part minus the base current value, which is the current flowing in the part not irradiated with light. Say. In the photosensor of the present invention, not all of the photo-induced charge carriers generated by the irradiation of information light move in the layer width direction of the photoconductive layer in the voltage applied state, and some of the photo-induced charge carriers It becomes as if it was trapped in a trap site existing in the conductive layer or at the interface between the electrode and the photoconductive layer.The trapped charges are accumulated over time, and when a voltage is applied, there is a photo-induced current generated by exposure. In addition, it is considered that an injection current from the electrode, which is induced by the trapped charges, flows to amplify the apparent photo-induced current amount with time. When the exposure is terminated while maintaining the state of applying the voltage, the photocarriers generated by the exposure are immediately attenuated and disappeared, but the decay of the trapped charges is gentle, so that they are induced by the trapped charges. It is presumed that a sufficient amount of the injected current from the electrode is flowed while being attenuated. This photo-induced current is an effect of current amplification triggered by light in the optical sensor of the present invention, and a current larger than the photo-induced current caused by the incident light expected in a normal photoconductor flows. This makes it possible to effectively provide optical information to the medium.

The photosensor portion comprising the electrode and the photoconductive layer in the present invention is semi-conductive as a whole including the electrode, and has a specific resistance in darkness of 10 ⁹ to 1 from the flowing current density.
It is preferably 0 ¹³ Ω · cm. In particular, the specific resistance is 1
The amplification effect is remarkable in the range of 0 ¹⁰ to 10 ¹¹ Ω · cm. An optical sensor having a specific resistance of more than 10 ¹³ Ω · cm does not show the amplifying effect as in the optical sensor of the present invention in the electric field intensity range of 10 ⁵ to 10 ⁶ V / cm. Further, in an optical sensor having a specific resistance of less than 10 ⁹ Ω · cm 2, a large amount of current flows, and noise due to the current is likely to occur, which is not preferable. On the other hand, a photosensitive element used for general electrophotography has a dark resistivity of 10 ¹⁴ Ω · cm to 10 ¹⁶ Ω · cm.
Are used, and the optical sensor of the present invention cannot achieve its purpose even when used for general electrophotography,
Further, a photosensitive element having a photoconductive layer having a large dark resistivity for general electrophotography cannot be used for the purpose of the present invention. The specific resistance ρ (Ω · cm) of the optical sensor is the current density J (A / cm ² ), The film thickness d of the optical sensor, the electrode area S, and the applied electrolytic strength E (V / cm) are defined as follows: ρ = (E · d / J · S) × (S / d) = E / J Since the equation holds, it can be obtained from the applied electric field strength and the current density.

When the information recording layer in the information recording medium is a polymer-dispersed liquid crystal, it is necessary to set the sensitivity of the optical sensor in the operating voltage range of the liquid crystal. That is,
The contrast voltage, which is the difference between the potential (bright potential) applied to the information recording medium in the exposed portion and the potential (dark potential) applied to the information recording medium in the unexposed portion, is set in the operating voltage region of the liquid crystal in the information recording medium. It is necessary to take a certain size. Therefore, for example, the dark potential applied to the liquid crystal layer in the unexposed portion of the optical sensor needs to be set to about the operation start potential of the liquid crystal. Therefore,
The resistivity of the information recording medium is 10 ¹⁰ to 10 ¹³ Ω · cm at room temperature.
In addition, the photosensor is required to have conductivity such that a base current of 10 ⁻⁴ to 10 ⁻⁷ A / cm ² is generated in a state where an electric field of 10 ⁵ to 10 ⁶ V / cm is applied, and preferably 10 ^-Five
The range of 10 ⁻⁶ A / cm ² is preferable. Base current is 10 ^-7
In the photosensor of less than A / cm ² , the liquid crystal is not oriented even in the exposed state, and in the photosensor with the base current of 10 ⁻⁴ A / cm ² or more, a large amount of current flows simultaneously with the voltage application even in the unexposed state, and the liquid crystal Even if it is oriented and exposed, no difference in transmittance can be obtained between the exposed portion and the unexposed portion. Since the operating voltage and the range vary depending on the liquid crystal, it is necessary to consider the voltage distribution in the information recording medium when setting the applied voltage and the voltage application time.

An information recording device incorporating an optical sensor is shown in FIG. In the figure, 1 is an optical sensor, 3 is an information recording medium, 1
3, 13 'are electrode layers, 14 is a photoconductive layer, 11 is an information recording layer, 15 is a substrate, 19 is a spacer, 21 is a light source, 22
Denotes a shutter having a driving mechanism, 23 denotes a pulse generator (power supply), and 24 denotes a dark box. First, a voltage is applied between the electrodes 13 and 13 'by a power source. When recording on this information recording medium, the information recording medium is heated by, for example, a heating resistor (not shown) embedded in its support, and the liquid crystal is heated to a temperature showing a liquid crystal phase. The memory property can be improved. That is, when recording to an information recording medium using a liquid crystal that is crystalline at room temperature and exhibits a smectic A phase at a temperature higher than room temperature, if the liquid crystal is heated to a temperature at which the smectic A phase is exhibited, the smectic A phase has an orientational order. Since it is high, the memory property can be improved.

When information light is made incident from the light source 21 while voltage is applied by the pulse generator 23 between the electrodes 13 and 13 ', photo carriers generated in the photoconductive layer 14 at the portion where the light is made incident are generated by both electrodes. The formed electric field moves to the interface on the information recording layer 11 side, the voltage is redistributed, the liquid crystal phase in the information recording layer 11 is aligned, and recording is performed according to the pattern of information light. In the figure, the photoconductor side is the positive electrode and the information recording medium side is the negative electrode.
The polarity is set according to the characteristics of the optical sensor.

The applied voltage is set by appropriately setting the voltage distributions of the optical sensor, the air gap, and the information recording medium according to the operating voltage of the liquid crystal material, and setting the voltage applied to the information recording layer to the operating voltage. It is recommended to set it in the area. Information recording by this optical sensor is possible as planar analog recording, and since the orientation of the liquid crystal phase can be oriented at the electrostatic charge level, the same high resolution as silver salt photography can be obtained, and exposure is also possible. The pattern is retained by being visualized by the alignment of the liquid crystal phase.

As a method of inputting information to the first information recording medium of the present invention, there are a method using a camera and a recording method using a laser. As a method using a camera, an information recording medium is used instead of the photographic film used in a normal camera, and an optical shutter can be used as a recording member, and an electric shutter can also be used. I will get it. Also, the optical information is separated into R, G, and B light components by a prism and a color filter, and taken out as parallel light. One for each of three R, G, and B information recording media.
Frames are formed, or R on the same information recording medium,
Color images can also be taken by recording G and B images side by side and recording them as one frame.

The laser recording method is as follows.
The light source is an argon laser (514.488n)
m), a helium-neon laser (633 nm), a semiconductor laser (780 nm, 810 nm, etc.) can be used,
This is performed by laser exposure scanning corresponding to an image signal, a character signal, a code signal, and a line drawing signal. An analog recording such as an image is performed by modulating the light intensity of the laser, and a digital recording such as a character, a code or a line drawing is performed by ON / OFF control of the laser light. In the case of halftone dot formation in an image, dot generator ON / OFF control is performed on laser light.

In the electrostatic information recorded on the information recording medium, when the information is reproduced by the transmitted light as shown in FIG. 3, the light A is transmitted because the liquid crystal is oriented in the electric field direction in the information recording portion. Then, the light B is scattered at a portion where no information is recorded, and contrast with the information recording portion is generated. The information recorded by the orientation of the liquid crystal is visible information that can be visually read, but it can also be read by enlarging it with a projector, and can be read with high accuracy by laser scanning or using a CCD. Can be read, and scattered light can be prevented by using a Schlieren optical system if necessary. Further, by making the electrode layer light-reflecting or laminating a light-reflecting layer on the electrode layer, it can be read by reflected light. Next, the second information recording medium of the present invention will be described. The second information recording medium is one in which a photoconductive layer is incorporated into the first information recording medium, and it is not necessary to separately prepare an optical sensor for recording information, and information recording can be performed by itself.

FIG. 4 is a sectional view for explaining the information recording medium of the present invention integrated with an optical sensor. FIG. 4A shows an information recording medium in which a photoconductive layer and an information recording layer are directly laminated, 3 in the figure is an information recording medium, 11 is an information recording layer, 13,
13 'is an electrode layer, 14 is a photoconductive layer, and 15 is a substrate.
The photoconductive layer 14 laminated on the electrode 13 ′ is similar to the photoconductive layer in the above-described photosensor, and the information recording layer 11 described in the section of the first information recording medium is formed on the photoconductive layer. Are laminated in the same manner as the first information recording medium.

Further, according to the method for forming the first information recording layer described above, it is possible to prevent the liquid crystal from seeping out from the surface of the information recording layer.
Since the electrode layer 13 can be formed by vapor deposition by sputtering, the electrode layer 13 can have a high insulating property, and a noise-free information recording layer can be formed when information is recorded. The electrode layers 13 and 13 'can adopt the same material and forming method as the electrode layer in the first information recording medium described above, but transparency is required when reading information recording by transmitted light, When reading with reflected light, either one of the electrode layers may be made light reflective, or a light reflecting layer such as a dielectric mirror layer may be laminated on any one of the electrode layers. Further, a substrate may be laminated on the electrode 13 on the information recording layer.

FIG. 4B is a diagram for explaining an information recording medium in which the intermediate layer 12 is provided between the photoconductive layer 14 and the information recording layer 11. When the photoconductive layer of the intermediate layer 12 is an organic photosensitive layer formed by using a solvent, the liquid crystal in the information recording layer may be eluted due to the interaction depending on the solvent, or the photoconductive layer may be used as the photoconductive layer. The photoconductive material is eluted by the solvent for forming the information recording layer at the time of coating and forming it on the surface, so that image unevenness occurs. Therefore, it is provided to prevent these problems. Examples of such an intermediate layer include inorganic materials such as SiO ₂ , TiO ₂ , CeO ₂ , Al ₂ O ₃ and Ge.
It is preferable to use O ₂ , Si ₃ N ₄ , AlN, TiN, MgF ₂ , ZnS, etc. and stack them by a vapor deposition method, a sputtering method, a CVD method or the like.

Further, as the intermediate layer, an aqueous solution such as polyvinyl alcohol, water-soluble polyurethane, or water glass, which is a water-soluble resin having a low compatibility with the organic solvent used for forming the photoconductive layer or the information recording layer, is used. Alternatively, the layers may be laminated by a spin coating method, a blade coating method, a roll coating method, or the like. Further, a coatable fluororesin may be used, and in this case, it may be dissolved in a fluorine-based solvent and applied by a spin coating method, or may be laminated by a blade coating method, a roll coating method or the like. As the applicable fluororesin, the fluororesin described in JP-A-6-265931 can be used.

Further, in the case of an organic material which is formed into a film under vacuum, there is no fear of dissolving the photoconductive layer during the film formation. Among these materials, polyethylene, polypropylene, poly (monochlorotrifluoroethylene), polytetrafluoroethylene, etc. can be used as a material to be formed by a vapor deposition method.
Moreover, polyparaxylylene or the like can be used as a material for forming a film by the CVD method. Among these, it is particularly preferable to use polyvinyl alcohol, and when a saponification degree of 97% or more and a polymerization degree of 1500 or more is used, the formation of the information recording layer can be made excellent.

The intermediate layer needs to be incompatible with both the organic photoconductive layer forming material and the information recording layer forming material, and in the case of having conductivity, diffusion of space charge is not possible. 10 ⁷ Ω due to deterioration of resolution.
Insulation of cm or more is required. Further, the intermediate layer is preferably thin because it lowers the distribution voltage applied to the liquid crystal layer or deteriorates the resolution, and is preferably 2 μm or less, preferably 0.1 to 1.5 μm. If it is too thin, not only image noise will be generated due to interaction over time, but also a problem of penetration due to defects such as pinholes will occur during multilayer coating. Since the permeability varies depending on the solid content ratio of the material to be laminated and applied, the type of solvent, and the viscosity, the thickness of the material to be laminated and coated may be appropriately set.
The intermediate layer is required to be transparent, and considering the voltage distribution applied to each layer, it is preferable to use a material having a high dielectric constant as well as a thin film. If the photoconductive layer is formed of an inorganic material and there is no interaction such as liquid crystal seepage with the information recording layer, it is not necessary to provide the intermediate layer.

A method of recording information on the second information recording medium will be described with reference to FIG. First, electrode 1
When the information light 18 is incident while applying a voltage between 3 and 13 ′, the photocarriers generated in the photoconductive layer 14 in the portion where the light is incident move due to the electric field formed by both electrodes,
When the voltage is redistributed, the liquid crystal phase in the information recording layer is aligned, and recording according to the pattern of the information light 18 is performed. The voltage may be applied for a predetermined time while the information light 18 is being incident. Since some liquid crystals have different operating voltages and ranges, when setting the applied voltage and applied voltage time, the voltage distribution in the information recording medium is set appropriately and the voltage distribution in the information recording layer is set in the operating voltage region of the liquid crystal. Good to do.

This information recording method is capable of surface analog recording and can obtain recording at the liquid crystal particle level so that high resolution can be obtained, and the exposure pattern is visualized by the alignment of the liquid crystal phase. Retained. Further, as the information input method, the same method as the method using a camera and the method using a laser described in the section of the first liquid crystal recording medium can be used. Further, a recording method using a laser can be similarly performed. Further, the spectral characteristics of the photoconductive layer do not need to be panchromatic, as long as they have sensitivity to the wavelength of the laser light source. When the information recorded on the second liquid crystal recording medium is read by the transmitted light, it is reproduced by the transmitted light from the information recording layer side as in the case of the first liquid crystal recording medium shown in FIG. The same applies when reading with reflected light.

Next, in the second liquid crystal recording medium of the present invention, as shown in FIG. 4C, the insulating light reflection layer 12 is provided between the photoconductive layer and the information recording layer in the second liquid crystal recording medium. ', The transparent insulating layer 12 "may be provided.
The recording light is incident on the recording information from the information recording layer side,
It can be read by the reflected light. Insulating light reflection layer 1
Examples of 2'include a dielectric mirror layer and a light-shielding film having light reflectivity. Examples of the dielectric mirror layer include those having a film thickness of λ / 4 and formed of, for example, a combination of silicon dioxide and titanium dioxide, or zinc sulfide and magnesium fluoride. As the light-shielding film having light reflectivity, for example, aluminum oxide, which is an insulating material, and germanium, which is a light-shielding material, are deposited from different vapor deposition sources at a deposition rate of aluminum oxide of 5 nm / sec and a deposition rate of germanium of 2 nm / sec. For example, a film having a film thickness of about 1 μm can be given by simultaneous vapor deposition. The transparent insulating layer 12 ″ has a problem that the insulating light-reflecting layer 12 ′ peels off when the information recording layer 11 is directly formed on the insulating light-reflecting layer 12 ′. The transparent insulating layer 12 ″ is provided to improve the formation.
The same as 2. The insulating light reflection layer 12 ',
Since the transparent insulating layer 12 ″ lowers the distribution voltage applied to the liquid crystal phase or deteriorates the resolution like the above-mentioned intermediate layer, it is preferable that the film thickness is thin, and the total thickness is 2 μm or less, preferably In this information recording medium, the reading light is
Since the photoconductive layer, which is generally colored, does not pass through, the reproduced information can be noise-free.

In the first and second liquid crystal recording media of the present invention, a primer is provided between the electrode layer, the light reflection layer, or the light reflection prevention layer, the substrate, etc. to improve adhesion. Layers may be provided. The primer layer is selected in consideration of the respective materials of the electrode layer, the light reflection layer or the light reflection prevention layer, and the substrate, and is coated with an ionizing radiation curable resin such as a thermoplastic resin, a thermosetting resin, or an ultraviolet curable resin. Or in the case of a combination of an inorganic material and an organic material, a known silane coupling agent, an organic metal compound such as an organic titanium compound or an organic aluminum compound may be used. Further, a primer layer may be provided between the electrode layer and the information recording layer, and the same material as described above can be used as the material thereof. In this case, the film thickness is 0.01 μm to 10 μm. It is a range. Since the voltage applied to the information recording layer can be controlled by improving the adhesion and changing the film thickness, it is possible to control the recordable exposure range.

Furthermore, the first and second liquid crystal recording media of the present invention are used by being cut in the width direction of the layer thereof into an appropriate size according to the mode of use, and the cut surface is the information recording layer. The inside is exposed and the liquid crystal layer exudes during storage. When this bleeding phenomenon occurs, a problem arises in that when information is recorded, accurate information recording cannot be performed at the edge of the liquid crystal recording medium. In order to prevent this, after cutting the liquid crystal recording medium into an appropriate shape, a resin layer may be applied or laminated on the cut surface in the same manner as above to form the same, and the cut surface may be protected.

The first and second liquid crystal recording media of the present invention record electrostatic information in a state in which the electrostatic information is visualized by the alignment of the liquid crystal. However, the visualized information is not erased and a memory property is added. The memory may be erased by heating to a high temperature near the isotropic phase transition, and can be used again for information recording. A first information recording medium of the present invention has an information recording layer composed of a liquid crystal phase and a resin phase on an electrode layer, and the second information recording medium has an electrode layer, a photoconductive layer, and an information layer. An information recording medium in which a recording layer and an electrode layer are sequentially provided, and at least one electrode of the electrode layer is transparent, and the information recording layer is composed of a liquid crystal phase and a resin phase and a liquid crystal. And at least one of a UV-curable oligomer or a UV-curable monomer, and a solution containing a fluorine-containing surfactant, wherein the liquid crystal is 4-alkyl-4′-cyanobiphenyl, 4-alkoxy- The liquid crystal composition comprising at least one of 4′-cyanobiphenyl contains the compound represented by the general formulas 1 and 2 or the compound represented by the general formula 2. Ri, graininess (roughness) is good, and can be an information recording medium that allows high contrast high quality information recording.

[0066]

EXAMPLES Examples will be described below. In the examples, “parts” means parts by weight and “%” means% by weight. Example 1 A film having a thickness of 1 mm was placed on a sufficiently cleaned glass substrate having a thickness of 1.1 mm.
An indium tin oxide (ITO) film having a thickness of 00 nm was formed by a sputtering method to obtain an electrode layer.

On the electrode, 9 parts of dipentaerythritol hexaacrylate (trade name: MPL-410: manufactured by Nippon Kayaku Co., Ltd.) and a photocuring initiator (2-hydroxy-2-methyl-1-phenylpropane-1-). ON, Ciba-Geigy Darocur 1173) 0.45 part Smectic liquid crystal of the following composition 11 parts

[0068]

Embedded image

A solution of 0.21 part of a surfactant (Florard FC-430 manufactured by Sumitomo 3M) uniformly dissolved in 20 parts of xylene (manufactured by Junsei Kagaku Co., Ltd., reagent grade) was applied using a spin coater, This was immediately held at 50 ° C. for 3 minutes, then held under reduced pressure vacuum for 2 minutes, returned to atmospheric pressure, and immediately irradiated with 800 mJ / cm ² of ultraviolet light,
An information recording layer having a film thickness of 6 μm was formed. The liquid crystal composition had a melting point of 5 ° C., a phase transition temperature (° C.) (measured at a rate of −2 ° C./min): isotropic phase (ISO) → (65-63) →
Nematic phase (N) → (62) → smectic A phase (S
_A ) → (−16) → crystal (Cr).

After the liquid crystal was extracted from the cut surface of the obtained information recording layer using hot methanol and dried, it was analyzed by a scanning electron microscope (Hitachi, S-800) at 10000.
Observation of the internal structure at a magnification of 0.6 μm shows that the surface of the layer is 0.6 μm.
It was found that the structure was covered with an ultraviolet curable resin corresponding to 10% of the film thickness, that is, 10% of the film thickness, and the inside of the layer was filled with resin fine particles having a particle size of 0.1 μm.

(Manufacturing Method of Optical Sensor) ITO having a film thickness of 100 nm was formed on a glass substrate having a thickness of 1.1 mm which was thoroughly washed.
The film was formed by a sputtering method to obtain an electrode layer of 80Ω / □. A solution of a bisazo pigment DPDP-3 (manufactured by Dainichiseika Kogyo Co., Ltd.) as a charge generating substance was used as a coating liquid on the electrode, and was coated with a blade coater and dried at 100 ° C. for 1 hour to laminate a 300 nm charge generating layer. . On the charge generation layer, a hydrazone-based solution DPDT as a charge transporting substance
-3 (manufactured by Dainichiseika Kogyo Co., Ltd.) was applied using a spinner and then dried at 80 ° C. for 2 hours to obtain a photoconductive layer having a film thickness of 10 μm and comprising a charge generation layer and a charge transport layer. Next, the obtained optical sensor and the information recording medium of the present invention produced as described above are arranged so as to face each other with a polyethylene terephthalate film of 10 μm as a spacer, and are incorporated in the recording apparatus of FIG. 75 with the recording medium side as negative
A DC voltage of 0 V was applied. With a voltage applied, exposure was performed from the light sensor side using a halogen lamp with an illuminance of 1000 lux as a light source for 0.1 second to photograph a gray scale. After the exposure was completed, the information recording medium was taken out and it was confirmed that the image information was recorded. In addition, a film scanner (LS-3510AF manufactured by Nikon) was used, a xenon lamp was used as a light source, and a wavelength filter (488) was used.
information was read by the transmitted light using the wavelength light through the (nm) and output by the sublimation printer, the standard deviation of the same density portion in the output image was 3.9,
A good image without graininess was obtained. Further, the transmittance of the exposed portion and the unexposed portion was measured using an ultraviolet and visible spectrophotometer, and it was 92% and 17% at 490 nm, and a high contrast ratio was obtained.

Example 2 The liquid crystal composition in the information recording layer of Example 1 was prepared.

[0073]

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An information recording medium was prepared in the same manner as in Example 1 except that the above was adopted. The liquid crystal composition had a melting point of 11
° C., the phase transition temperature (℃) (- 2 ℃ / measurement with a rate): isotropic phase (ISO) → (65) → nematic phase (N) → (61) → smectic A phase (S _A) → It is a crystal (Cr). The transmittance of the exposed and unexposed areas was measured using an ultraviolet and visible spectrophotometer.
A high contrast ratio was obtained, which was 90% and 19% at 0 nm.

Example 3 Instead of the liquid crystal composition in the information recording layer of Example 1,

[0076]

[Chemical 6]

An information recording medium was prepared in the same manner as in Example 1 except that the above was used. The liquid crystal composition had a phase transition temperature (° C.) (measured at a rate of −2 ° C./min): isotropic phase (ISO) → (56) → nematic phase (N) → (55).
→ is a smectic A phase (S _A) → crystal (Cr). The transmittance of the exposed and unexposed areas was measured with an ultraviolet and visible spectrophotometer to find that it was 90 at 490 nm.
% And 28%, and a high contrast ratio was obtained.

Example 4 Instead of the liquid crystal composition in the information recording layer of Example 1,

[0079]

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An information recording medium was prepared in the same manner as in Example 1 except that the above was used, and information was recorded in the same manner. The standard deviation of the same density portion in the output image was 4.2, and the graininess was A good image was obtained. The liquid crystal composition had a melting point of 9 ° C., a phase transition temperature (° C.) (measured at a rate of −2 ° C./min): isotropic phase (ISO) → (56) →
Nematic phase (N) → (55) → Smectic A phase (S
_A ) → (−13) → crystal (Cr). Further, the transmittance of the exposed portion and the unexposed portion was measured using an ultraviolet and visible spectrophotometer, and was 88% at 490 nm and 33%.
%Met.

Example 5 Instead of the liquid crystal composition in the information recording layer of Example 1,

[0082]

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An information recording medium was produced in the same manner as in Example 1 except that the above was carried out, and information was recorded in the same manner. The standard deviation of the same density portion in the output image was 4.2, and the graininess No good image was obtained. The liquid crystal composition had a melting point of 4 to 8 ° C., a phase transition temperature (° C.) (measured at a rate of −2 ° C./min): isotropic phase (ISO) → (61) → nematic phase (N) → (59). ) → Smectic A phase (S _A ) → (−14) → crystal (Cr). Also,
The transmittance of the exposed and unexposed areas was measured using an ultraviolet and visible spectrophotometer, and it was 87% at 490 nm.
And 20%, and a high contrast ratio was obtained.

Example 6 An optical sensor was formed on a transparent electrode by the same method as the method for producing the optical sensor in Example 1. Then, a solution prepared by dissolving polyvinyl alcohol (AH-26: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) in water at a concentration of 5% by weight was applied onto the charge transport layer of the photosensor using a spinner, and 8
It was dried at 0 ° C. for 1 hour to form an intermediate layer having a film thickness of 1.3 μm. Further, the liquid crystal recording layer of Example 1 was formed on the intermediate layer to a thickness of 6 μm by the same method, and the ITO electrode was further formed on the liquid crystal recording layer by the sputtering method to obtain the second information recording medium of the present invention. Was produced. Next, a grayscale was projected and exposed from the photoconductive layer side of this information recording medium, and at the same time, a DC voltage of 400 V was applied between the ITO electrodes with the photoconductive layer side being positive and the information recording layer side being negative. Exposure with a halogen lamp with an illuminance of 1000 lux as a light source was performed for 1/30 seconds from the photoconductive layer side in a voltage applied state, and a gray scale was photographed. After the exposure, a transmission image corresponding to gray scale was formed on the information recording medium. further,
This information recording medium was read by a scanner using a CCD line sensor and output by a sublimation printer,
The standard deviation of the same density portion in the output image is 3.
6, a good image without graininess was obtained.

Comparative Example 1 Instead of the liquid crystal composition in the information recording layer of Example 1,

[0086]

Embedded image

An information recording medium was produced in the same manner as in Example 1 except that was used. The liquid crystal composition has a melting point of 9 to
12 ° C., phase transition temperature (° C.) (measured at a rate of −2 ° C./min): isotropic layer (ISO) → (56) → nematic phase (N) → (55) → smectic A phase (S _A ). → (-1
2) → crystal (Cr).

The transmittance of the exposed and unexposed areas was measured using an ultraviolet and visible spectrophotometer, and it was 490n.
The contrast ratio is low at 87% and 36% at m, and a good image cannot be obtained.

[0089]

INDUSTRIAL APPLICABILITY In an information recording medium having an information recording layer composed of a liquid crystal phase and a resin phase on the electrode layer, since the liquid crystal has a specific chemical structure, it has high contrast and graininess (roughness). It is possible to obtain an information recording medium that enables good and high-quality information recording.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an information recording medium of the present invention.

FIG. 2 is a diagram illustrating an information recording device incorporating an optical sensor.

FIG. 3 is a diagram illustrating a method of reproducing information recorded on an information recording medium.

FIG. 4 is a sectional view illustrating an information recording medium of the present invention integrated with an optical sensor.

FIG. 5 is a cross-sectional view illustrating a method of recording information on an information recording medium integrated with an optical sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical sensor, 3 ... Information recording medium, 11 ... Information recording layer, 12 ... Intermediate layer, 13, 13 '... Electrode layer, 14 ... Photoconductive layer, 15 ... Substrate, 18 ... Information light, 19 ... Spacer,
21 ... Light source, 22 ... Shutter having drive mechanism, 23
… Pulse generator (power supply), 24… Dark box

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G11B 9/00 9075-5D G11B 9/00

Claims (2)

[Claims] 1. An information recording medium having an information recording layer made of a liquid crystal phase and a resin phase on an electrode layer, and the information recording layer made of an ultraviolet curable resin and a fluorosurfactant, wherein the liquid crystal phase is: In a liquid crystal composition comprising at least one of 4-alkyl-4-cyanobiphenyl and 4-alkoxy-4′-cyanobiphenyl, at least one of the compounds represented by the following general formulas 1 and 2 is represented by the general formula 1. An information recording medium containing a compound. Embedded image 2. An electrode layer, a photoconductive layer, an information recording layer, and an electrode layer are sequentially provided, at least one of the electrode layers is transparent, and the information recording layer is an ultraviolet curable resin and a fluorine-based surfactant. In the information recording medium consisting of, a liquid crystal composition in which the liquid crystal phase is at least one of 4-alkyl-4-cyanobiphenyl and 4-alkoxy-4′-cyanobiphenyl, An information recording medium comprising at least a compound represented by the general formula 1 of the compounds represented. Embedded image