JPH0713132A - Information recording medium - Google Patents

Abstract

PURPOSE:To obtain a recording medium having high sensitivity which enables information recording with good contrast by forming a skin layer comprising only a UV-curing resin as the outer surface of an information recording medium and forming the information recording layer to have a specified range of film thickness. CONSTITUTION:This information recording medium 3 is produced by forming an electrode layer 13 and information recording layer 11 in this order on a substrate 15. The information recording layer 11 consists of a liquid crystal phase and a resin phase. The information recording layer 11 is formed by applying a mixture soln. of liquid crystal, material to form a UV-curing resin, and fluorine-base surfactant on the electrode layer 13 and then hardening by irradiation of UV rays so that a skin layer comprising only the UV-curing resin is formed as the outer surface. Besides, the information recording layer 11 has 1mum-30mum film thickness and the thickness of the skin layer is 0.01-20% of the film thickness of the information recording layer 11. By controlling the average film thickness of the information recording layer 11 to lmum-30mum, the obtd. information recording medium has high sensitivity and high contrast.

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 which can obtain electrostatic information recorded by an exposure recording method at the time of voltage application as visible information, and particularly, to record information having high sensitivity and excellent contrast ratio. The present invention relates to a possible information recording medium.

[0002]

2. Description of the Related Art In the conventional electrophotographic technology, there is known an information recording medium in which a liquid crystal cell in which a nematic liquid crystal is sealed on a photoconductive layer between a pair of electrodes and an insulating layer for liquid crystal alignment are sequentially laminated. Is known in which information is exposed with a voltage applied between electrodes to lower the resistance of the photoconductive layer in the information exposed portion to align the liquid crystal and obtain a visible image using a deflector.

This information recording medium needs to be made into cells in order to enclose the liquid crystal, and in order to perform twist nematic orientation in the initial stage, an insulating film whose both surfaces are oriented by rubbing treatment is provided, and further, the cells are further provided. It is necessary to mix spacers to keep the gap constant, and it is not possible to obtain a high-resolution image. There is also an optical problem because a rigid and transparent support is required to form the gaps or cells.
Further, there is also a problem that such an alignment-processed material in the initial state cannot be detected unless a polarizing plate is used for reading.

On the other hand, recently, a polymer dispersion type liquid crystal has been developed for the liquid crystal layer in a liquid crystal cell, and in such a medium, it is held in a state of being sandwiched between two substrates having ITO electrodes. This medium is substrate / ITO electrode /
When used in a method of recording electrostatic information on the liquid crystal layer by a discharge phenomenon corresponding to information light by exposure with voltage application in the state of facing the photoconductor, the polymer dispersion type There is a problem in that the phenomenon of liquid crystal bleeding occurs on the surface of liquid crystal, which causes noise when recording information. When the substrate / ITO electrode / liquid crystal layer / ITO electrode is used in a method for recording information by orienting a liquid crystal layer by applying a voltage between both electrodes, the ITO of the surface layer is also spilled due to seepage of liquid crystal. There is a problem in that the electrodes are cracked, floated, and the like, and the conductivity is lowered.

The applicant of the present invention uses an ultraviolet curable resin as a resin for forming the information recording layer in this type of medium, whereby a liquid crystal phase and an ultraviolet curable resin phase are dispersed inside the information recording layer. It was found that it has a structure and that the outer surface thereof can be used as an ultraviolet-curing resin skin layer, and the application was filed earlier (Japanese Patent Application No. 4-24580). Since the surface of this information recording layer is formed only of the resin layer, liquid crystal bleeding phenomenon does not occur, noise-free recording can be performed in information recording using an optical sensor, and sputtering is performed on the resin layer. This makes it possible to directly form an electrode layer such as an ITO film.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to an improvement of an information recording medium using this type of polymer dispersed liquid crystal, and is an information recording which enables information recording with high sensitivity and good contrast. The challenge is to provide media.

[0007]

A first information recording medium of the present invention is an information recording medium having an information recording layer composed of a liquid crystal phase and a resin phase on an electrode layer, the information recording layer comprising:
After coating the electrode layer with a mixed solution of liquid crystal, UV-curable resin forming material and fluorine-based surfactant, it is cured by UV irradiation and its outer surface is formed into a skin layer consisting of only UV-curable resin. And the information recording layer is 1 μm
It is characterized by having a film thickness of ˜30 μm.

The second information recording medium of the present invention is an information recording medium in which an electrode layer, a photoconductive layer, an information recording layer, and an electrode layer are sequentially provided, and at least one electrode is transparent and the information recording is performed. The layer is coated with a mixed solution of liquid crystal, a UV-curable resin forming material and a fluorine-based surfactant on the electrode layer, and then cured by UV irradiation, and the outer surface of the layer becomes a skin layer consisting of only the UV-curable resin. The information recording layer is formed and has a film thickness of 1 μm to 30 μm.

Further, the third information recording medium of the present invention is an information recording medium in which a transparent electrode layer, a photoconductive layer, an insulating light reflecting layer, an information recording layer and a transparent electrode layer are provided in this order. After coating the electrode layer with a mixed solution of a liquid crystal, a UV-curable resin forming material, and a fluorine-based surfactant, the electrode layer is cured by UV irradiation, and the outer surface is formed into a skin layer consisting of only the UV-curable resin. In addition, the information recording layer has a thickness of 1 μm to 30 μm, and the thickness of the skin layer is in the range of 0.01% to 20% with respect to the thickness of the information recording layer. .

FIG. 1A is a diagram for schematically explaining a cross section of a first information recording medium of the present invention, in which 3 is an information recording medium, 11 is an information recording layer, and 13 is an electrode layer. , 15 are substrates.

The information recording layer 11 is composed of a liquid crystal phase and a resin phase, and a smectic liquid crystal is used as a liquid crystal material.
A nematic liquid crystal, a cholesteric liquid crystal, or a mixture thereof can be used, but it is preferable to use a smectic liquid crystal from the viewpoint of so-called memory property that retains the orientation of the liquid crystal and permanently retains information.

As the smectic liquid crystal, a liquid crystal substance exhibiting a smectic A phase such as a cyanobiphenyl type, a cyanoterphenyl type, a phenyl ester type having a long carbon chain at a terminal group of a substance exhibiting liquid crystallinity, and a ferroelectric type, a ferroelectric substance A liquid crystal substance exhibiting a smectic C phase used as a liquid crystal,
Alternatively, a liquid crystal substance exhibiting smectic H, G, E, F or the like can be given. A nematic liquid crystal may be used, and the memory property can be improved by mixing with a smectic or cholesteric liquid crystal, and examples thereof include a Schiff base type, an azoxy type, an azo type, a benzoic acid phenyl ester type, and a phenyl cyclohexylate. Known nematic liquid crystals such as ester type, biphenyl type, terphenyl type, phenyl cyclohexane type, phenyl pyridine type, phenyl oxazine type, polycyclic ethane type, phenyl cyclohexene type, cyclohexyl pyrimidine type, phenyl type and tolan type can be used. Also, a microcapsule obtained by mixing polyvinyl alcohol or the like with a liquid crystal material can be used. When selecting a liquid crystal material, it is preferable to use a material having a large anisotropy in the refractive index because the contrast can be obtained.

As a material for forming the resin phase, a solvent-soluble thermosetting resin having compatibility with a liquid crystal material and a common solvent, such as an acrylic resin, a methacrylic resin, a polyester resin, a polystyrene resin, and these are mainly used. The above-mentioned copolymers, epoxy resins, silicone resins, etc. may be used, but ultraviolet curable resins that are compatible with the liquid crystal material in the monomer or oligomer state, or in the monomer or oligomer state Therefore, those having compatibility with the liquid crystal material and the same solvent can be preferably used.

Examples of such UV-curable resins include acrylic acid esters, methacrylic acid esters, etc. In the state of monomers and oligomers, 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. Type, ester type oligomer, further nonylphenol modified acrylate, N-vinyl-2-pyrrolidone,
Examples thereof include monofunctional monomers or oligomers such as 2-hydroxy-3-phenoxypropyl acrylate.

The solvent is a solvent having a relative evaporation rate with respect to -n-butyl acetate of less than 2, and is a solvent common to each of the liquid crystal, the ultraviolet curable resin-forming material, the photocuring agent and the fluorine-based surfactant. It is necessary to be. 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. Volatile at constant temperature, And R is less than 2.

Solvents usable in the present invention include:
Xylene (R = 0.76), cyclohexanone (R =
0.32) and the like having a relatively slow evaporation rate are preferable,
Further, halogenated hydrocarbon solvents such as chloroform, alcohol derivative solvents such as methyl cellosolve, and ether solvents such as dioxane are also included. In addition, specifically, methyl alcohol,
Denatured ethanol, isopropanol, n-propanol, sec-butanol, isobutanol, n-butanol, methylisobutylcarbinol, diisobutylcarbinol, hexylene glycol, acetic acid-sec-butanol, isobutyl acetate (98%), n-butyl acetate , Methylaluminum acetate, aluminum acetate (95% isomer mixture), ethyl lactate, methyloxitol, ethyloxitol, isopropyloxitol, methyloxitol acetate, ethyloxitol acetate, butyloxitol, methyldioxitol, ethyl Dioxitol, butyldioxitol, butyldioxitol acetate, methyl isobutyl ketone, ethyl amyl ketone, Pent-O-xone (ME-6K), methylcyclohexanone, di Sobuchiruketon, diacetone alcohol, isophorone, 1,4-dioxane, perchlorethylene, dichloropropane, 2-nitropropane,
Toluene, SBP100 / 140, rubber solvent, xylene, SBP140 / 165, SBP6, SBP11, S
hellsolA, white spirit (LAWS),
ShellsolE, ShellsolTD, White Spirit (115 ° F flash), ShellsolT,
Shellsol AB, Distilate, Sol
Vent300, ShellsolN, Shellso
lRA, ShellsolK, ShellsolR, S
olvent350 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 (manufactured by Ciba Geigy). "Irgacure 184"), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1
-On (Caro Geigy's "Darocur 111
6 "), benzyl dimethyl ketal (" Irgacure 651 "manufactured by Ciba-Geigy), 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropanone-1 (“Irgacure 907” manufactured by Ciba-Geigy),
A mixture of 2,4-diethylthioxanthone ("Kayacure DETX" manufactured by Nippon Kayaku Co., Ltd.) and ethyl p-dimethylaminobenzoate ("Kayacure EPA" manufactured by Nippon Kayaku Co., Ltd.),
Isopropyl thioxanthone (a mixture of "Kunta Cure ITX" manufactured by Ward Brekinsop Co., Ltd.) and ethyl p-dimethylaminobenzoate can be mentioned, but it is in a liquid form.
-Hydroxy-2-methyl-1-phenylpropane-1
-One is particularly preferable in terms of compatibility with the liquid crystal material, the polymer-forming monomer or the oligomer.

The content ratio of the liquid crystal to the total amount of the liquid crystal and the resin can be 10% by weight to 90% 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 oriented by the information recording, and when it exceeds 90% by weight, the phenomenon such as exudation of the liquid crystal occurs to cause image unevenness. Not preferable. However, in the information recording medium of the present invention, the proportion of the liquid crystal is preferably 40% by weight to 80% by weight. According to the present invention, since the outer surface of the information recording layer can be a skin layer made of a resin layer, the content of the liquid crystal can be increased, whereby a highly sensitive and high contrast information recording medium can be obtained. The operating voltage can be lowered.

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

In the present invention, a fluorine-containing surfactant is added for the purpose of forming a skin layer made of only resin on the surface of the information recording layer as well as wettability with respect to the electrode layer. Examples of such fluorine-based surfactants include Sumitomo 3M Ltd.'s Florard FC-430, Florard FC-431, N- (n-propyl) -N- (β-acryloxyethyl) -perfluoro. Octyl sulfonic acid amide [Mitsubishi Materials Corp. EF-125M], N
-(N-Propyl) -N- (β-methacryloxyethyl) -perfluorooctylsulfonic acid amide [EF-135M manufactured by Mitsubishi Materials Corporation], perfluorooctanesulfonic acid [EF-10 manufactured by Mitsubishi Materials Corporation]
1], perfluorocaprylic acid [Mitsubishi Materials Corporation
EF-201], N- (n-propyl) -N-perfluorooctanesulfonic acid amide ethanol [EF-121 manufactured by Mitsubishi Materials Corp.], and EF-102 and EF-103 manufactured by Mitsubishi Materials Corp. , The same EF-10
4, the same EF-105, the same EF-112, the same EF-12
1, the same EF-122A, the same EF-122B, the same EF-1
22C, EF-122A3, EF-123A, E
F-123B, same EF-132, same EF-301, same E
F-303, EF-305, EF-306A, E
F-501, EF-700, EF-201, EF
-204, EF-351, EF-352, EF-
801, EF-802, EF-125DS, EF
-1200, EF-L102, EF-L155, EF-L174, EF-L215 and the like. In addition, 3- (2-perfluorohexyl) ethoxy-1,
2-dihydroxy propane [M manufactured by Mitsubishi Materials Corporation]
F-100], Nn-propyl-N-2,3-dihydroxypropyl perfluorooctyl sulfonamide [MF-110 manufactured by Mitsubishi Materials Corporation], 3- (2-
Perfluorohexyl) ethoxy-1,2-epoxypropane [MF-120 manufactured by Mitsubishi Materials Corporation], N-
n-propyl-N-2,3-epoxypropyl perfluorooctyl sulfonamide [MF-130 manufactured by Mitsubishi Materials Corporation], perfluorohexyl ethylene [MF-140 manufactured by Mitsubishi Materials Corporation], N- [3-] Trimethoxysilyl) propyl] perfluoroheptylcarboxylic acid amide [MF-150 manufactured by Mitsubishi Materials Corporation],
N- [3-trimethoxysilyl) propyl] perfluoroheptylsulfonamide [M manufactured by Mitsubishi Materials Corporation]
F-160] and the like. The fluorine-based surfactant is 0.1 to 20% by weight based on the total amount of liquid crystal and resin forming material.
Used in proportion. Further, if necessary, a leveling agent may be added in order to improve the suitability for application of the solution and improve the surface property.

Next, a method of forming the information recording layer will be described step by step. (1) Mixing a liquid crystal, a resin-forming material, a photopolymerization initiator, and a surfactant with a solvent having a relative evaporation rate of less than 2 with respect to -n-butyl acetate to obtain a solid content concentration of 10 to 60% by weight. Use as a solution. Solvent dilution is 1 to 500 cps (2
0 ° C.), preferably 10 to 200 cps (20 ° C.). If the viscosity is low, the coating solution will flow and the film thickness after coating cannot be maintained, and if the viscosity is high, leveling will be difficult. Further, the liquid crystal is heated to a temperature above the temperature at which the liquid crystal retains an isotropic phase, preferably within the temperature range of the isotropic phase transition point + 10 ° C. to dissolve it. At this time, the gelled material, dust and the like of the ultraviolet curable resin forming material present in the solution are removed by filtering. The presence of gelled matter, dust, etc. causes noise as an information recording medium.

Further, the mixed solution is heated above the isotropic phase temperature, but at this time, if the solvent is evaporated and dried, the mixed solution undergoes phase separation and a uniform film is not formed. Therefore, a solvent having a relative evaporation rate with respect to -n-butyl acetate of less than 2 is used as the solvent. If the relative evaporation rate is greater than 2, the evaporation will be too fast and the above problems will occur.
Usually, as long as it can be dissolved by heating up to 70 ° C., there is no problem even if R is 0.3 or more and 1 or less, and xylene (R = 0.7) may be used,
Further, when heating at 70 ° C. or higher is required for dissolution, a solvent having R less than 0.3, for example, cyclohexanone (R = 0.2) may be used.

(2) Next, the mixed solution is applied uniformly on the electrode layer at room temperature by a coating method such as spin coater, bar coat, blade coater or roll coater.

(3) The coating layer is maintained above the temperature at which the liquid crystal maintains an isotropic phase, preferably within the temperature range of the isotropic phase transition point ± 10 ° C., and the solvent is removed by evaporation. The temperature of the coating layer is
When the temperature is lower than the isotropic phase transition temperature by 10 ° C. or more, there arises a problem that the phase separation between the liquid crystal and the ultraviolet curable resin material becomes large. That is, the liquid crystal domain grows too much, the skin layer is not completely formed on the surface of the information recording layer, liquid crystal bleeding phenomenon occurs, and the ultraviolet curable resin becomes matte, which makes it difficult to accurately capture information. , Not preferable. In addition, the ultraviolet curable resin may not be able to hold the liquid crystal and may not even form the information recording layer. Also, the isotropic phase transition point +1
When the temperature is 0 ° C. or higher, the detailed reason is unknown, but the phase separation between the liquid crystal phase and the resin phase becomes unclear in the information recording layer.

(4) In order to completely remove the solvent, the drying treatment may be carried out in two steps of hood drying and vacuum drying, which prevents unevenness on the surface of the information recording layer due to air flow. However, interference fringes can be prevented.

(5) Next, the dried coating layer is exposed to UV.
It is irradiated with ultraviolet rays using a lamp to cure it, but the coating layer
When irradiating ultraviolet rays to the
Ultraviolet light in which the wavelength portion of 00 nm to 400 nm is 1% or more
0.1mJ / cm using a wire ²Illuminate with more energy
By spraying, excellent phase separation between liquid crystal phase and resin phase
An information recording layer is obtained.

When the information recording layer is formed in this way,
0.01% to 3% of the thickness of the information recording layer on the surface of the information recording layer
A skin layer having a film thickness of 0% is formed, and the inside of the information recording layer has a primary particle diameter of 0.03 μm to 0.
It can have a structure in which resin particles of 3 μm are filled, and a liquid crystal phase communicates between them. When a polyfunctional UV-curable resin material having a parameter represented by the average molecular weight / average functional group of 160 or less is used as the UV-curable resin forming material, 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 liquid crystal in the information recording layer, and to prevent the liquid crystal from seeping out to the surface of the information recording layer. Disturbance of the image due to this 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, there is a problem that the 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 not effectively applied to the liquid crystal phase in the information recording layer. However, there is a problem that the liquid crystal drive becomes slow and the sensitivity is lowered. In addition, if the phase separation is incomplete, when the UV curable resin forming material is irradiated with a UV lamp containing infrared rays, unnecessary heating causes non-uniform shrinkage, which is a fatal homogeneous and homogeneous information as an information recording medium. It causes a serious problem that the recording layer cannot be formed.

(6) The average film thickness of the information recording layer thus formed is 1 μm to 30 μm. If the film thickness is too thick, the operating voltage will be high, but generally it is better to make the film thickness thinner to increase the sensitivity and thicker to increase the contrast. In order to have excellent sensitivity and contrast ratio, the film thickness is preferably 3 μm.
The film thickness may be m to 20 μm, and more preferably 5 μm to 10 μm. As a result, the operating voltage can be lowered 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, liquid crystal oozes out and its surface will be described later. Even if the information is recorded by the optical sensor, it becomes noise. Therefore, it is preferable that the thickness of the skin layer is 0.01% to 30% of the thickness of the information recording layer. Although the detailed reason is not clear, the film thickness of the skin layer can be appropriately adjusted by the kind of the ultraviolet curable resin, the ultraviolet irradiation amount, the addition of a fluorine-based surfactant, and the like.

Further, in the information recording medium of the present invention,
The thickness of the information recording layer needs to be applied accurately and uniformly. However, by forming the information recording layer by the above method, the uniformity of the film thickness is as follows when the film thickness is 5 μm to 10 μm. The surface roughness Ra can be set to 200 Å or less, the contrast is not uneven, and the shading phenomenon does not occur 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, but the information recording of the present invention. When the resin has a large liquid crystal content such as a layer and the resin phase forms in a particle shape, the domain size of the liquid crystal is taken into consideration much like a polymer dispersed liquid crystal having a low normal liquid crystal content. Since there is no need, it is possible to easily provide an information recording medium with high sensitivity and high contrast ratio.

After the mixed solution of the resin forming material and the liquid crystal is applied and dried, a smooth substrate such as a quartz glass plate is placed on the applied surface, and ultraviolet rays are applied while uniformly applying pressure to the applied layer. When the information recording medium is obtained by irradiating to cure the curable resin and then peeling off the substrate, an information recording layer having less variation in light transmittance can be obtained.

Further, by forming a skin layer on the surface of the information recording layer in the present invention, the exudation of liquid crystal can be prevented, but in order to further increase the surface hardness of the information recording layer, A resin layer may be laminated on. As such a resin layer, a thermoplastic resin film, a thermosetting resin film, an ionizing radiation curable resin film such as an ultraviolet curable resin, or the like is formed by a coating method. Further, polyvinyl alcohol, which is a water-soluble resin having low compatibility with organic solvents,
Examples thereof include water-based polyurethane and water glass. An aqueous solution thereof may be applied by a blade coater, a roll coater, a spin coater or the like to be laminated. Further, resins such as polytetrafluoroethylene, fluorinated ethylene propylene, tetrafluoroethylene perfluoroalkyl vinyl ether copolymer, polyimide resin, polyetherketone resin, and polyvaraxylylene are dissolved in a fluorine-based solvent to form a coating film. It can also be laminated. Further, instead of such a coating method, a film may be formed by sticking the above-mentioned various polymer films to the surface of the information recording layer via a laminate or an adhesive.

As the material for forming the resin layer, particularly preferable are polyethylene terephthalate, polyethylene, polypropylene, ultraviolet ray and electron beam curable resins and the like. Even when formed into a thin film, a hard coat layer having high surface hardness can be obtained. Therefore, the durability of the information recording medium can be improved. The thickness of the resin layer is 0.1 μm to 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 phase at the time of information recording becomes low. Therefore, when the optical sensor described later is used as the information recording mode, the applied voltage is increased. There is a need to. By laminating such a resin layer, it is possible to further 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. By changing the film thickness, the voltage applied to the information recording layer can be controlled, so that the recordable exposure range can be controlled.

The electrode layer 13 is required to be transparent when reading the information recorded in the information recording layer with transmitted light, and has a specific resistance value of 10 ⁶ Ω · cm or less. Film, conductive film of inorganic metal oxide such as indium tin oxide,
It is an organic conductive film such as a quaternary ammonium salt. 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 100 to 3000 Å, and the entire surface between the information recording layer and Alternatively, it is formed according to the formation pattern of the information recording layer.

When the information recorded on the information recording layer is read by reflected light, the electrode layer may be made light reflective or the transparent electrode layer may be laminated with a light reflective layer. In order to make the electrode layer light-reflecting, a metal electrode such as aluminum may be used. As the light reflecting layer, for example, a dielectric mirror layer can be cited, and it is preferable to provide it on one side or on 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 may have a shape such as a card, a film, a tape, a disc, etc., but the support strongly supports the information recording medium, and when the information recording layer has supportability, No need to provide. The material and thickness of the support are not particularly limited, and include, for example, a flexible plastic film or glass,
Rigid bodies such as plastic sheets and cards are used. Specifically, when the information recording medium has a flexible film, tape, disc, or card shape, a flexible plastic film is used, and when strength is required, a rigid sheet or glass. Inorganic materials and the like are used.

When information is reproduced by transmitted light, a layer having an antireflection effect may be laminated if necessary, or the transparent substrate may be adjusted to a film thickness capable of exhibiting the antireflection effect. Antireflection property may be imparted by combining the both.

Next, an information recording method on the first information recording medium of the present invention will be described. The information is recorded using a method such as an optical sensor, heat, laser, corona charging, etc., but preferably, an optical sensor is used to record the information. Such an optical sensor is one in which an electrode layer and a photoconductive layer are laminated on a transparent substrate, and the photoconductive layer is a single layer having a charge generating function and a charge transporting function corresponding to information light at the same time. System, and a laminated system in which a charge generation layer and a charge transport layer are sequentially laminated on an electrode layer, and are formed by the same material and forming method as the photoconductive layer in the second information recording medium described later. It The photoconductive layer generally has a function of generating photocarriers (electrons and holes) in the irradiated portion when irradiated with light, and these carriers can move in the layer width. When present, the effect is significant. An example of such an optical sensor is Japanese Patent Application No. 4-2879.
The optical sensor described in No. 83 is mentioned. In the optical sensor described in this publication, the electric field or the amount of electric charge applied to the information recording medium at the time of light irradiation is amplified as the light is irradiated, and the conductivity of the sensor is maintained when the voltage is continuously applied even after the light irradiation is completed. It has a function of continuing and continuously applying an electric field or an electric charge to the information recording medium.

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, and 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
Is a shutter having a drive mechanism, 23 is a pulse generator (power supply), and 24 is a dark box.

First, a voltage is applied between the electrodes 13 and 13 'by a power source. When recording on the information recording medium, the information recording medium is heated by, for example, resistance heating (not shown) embedded in the support to heat the liquid crystal to a temperature at which the liquid crystal phase is exhibited. Can be improved.

When information light is made incident from the light source 21 while applying a voltage 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 on both electrodes. By the electric field formed by, the 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, but it goes without saying that the polarity is set according to the discharge characteristics of the optical sensor.

When setting the applied voltage, since some liquid crystal materials operate at a low voltage, the voltage distributions of the optical sensor, the air gap, and the information recording medium are appropriately set and applied to the information recording layer. The voltage should be set in its operating voltage range. Information recording by this optical sensor is possible as planar analog recording, and since the liquid crystal phase can be aligned at the electrostatic charge level,
A high resolution similar to that of silver salt photography can be obtained, and the exposure pattern is retained as a visible image due to the orientation of the liquid crystal phase.

As a method of inputting information to the first information recording medium of the present invention, there are a camera method and a laser recording method. As a method using a camera, an information recording medium is used instead of a photographic film used in a normal camera, and it is used as a recording member, and an optical shutter can be used and an electric shutter can also be used. It is profitable. Further, 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 to form one frame with three sets of R, G, B decomposed information recording media, or on one plane. Color images can also be taken by arranging the R, G, and B images side by side to form one frame for one set.

The laser recording method is as follows.
Argon laser (514.488n)
m), a helium-neon laser (633 nm), a semiconductor laser (780 nm, 810 nm, etc.) can be used,
Laser exposure corresponding to an image signal, a character signal, a code signal, and a line drawing signal is performed by scanning. 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, laser light is subjected to dot generator ON-OFF control.

As shown in FIG. 3, when the electrostatic information recorded on the information recording medium is reproduced by transmitted light, the light A is transmitted because the liquid crystal is oriented in the electric field direction in the information recording portion. On the other hand, the light B is scattered at the portion where no information is recorded, and the contrast with the information recording portion can be obtained.
The information recorded by the orientation of the liquid crystal is visible information that can be visually read, but it can also be magnified and read by a projector, laser scanning, or CC.
Information can be read with high accuracy by reading using D, and scattered light can be prevented by using a Schlieren optical system as needed. Furthermore, as described above, it is possible to read by reflected light by making the electrode layer itself light reflective or by laminating a light reflective layer on the electrode layer.

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 does not require an optical sensor or the like for recording information and can record information by itself. FIG. 1B is a diagram for schematically explaining the cross section, in which 3 is an information recording medium, 11 is an information recording layer, 13 and 13 'are electrode layers, 14 is a photoconductive layer,
Reference numeral 5 is a substrate.

Photoconductive layer 14 laminated on electrode 13 '
There are a single layer type and a laminated type in which a charge generation layer and a charge transport layer are laminated. The photoconductive layer generally has a function of generating photocarriers (electrons and holes) in the irradiated portion when irradiated with light, and these carriers can move in the layer width. When present, the effect of the layer is remarkable, but in particular, the electric field applied to the information recording layer during light irradiation to the photoconductive layer is amplified with light irradiation, and the voltage is applied even after the light irradiation is completed. It is preferable to have a function of continuing the application of the magnetic field to keep its conductivity and continuously applying the electric field to the information recording medium.

First, the single-layer photoconductive layer is formed of an inorganic photoconductive substance or an organic photoconductive substance. As the inorganic photoconductive substance, Se, Se-Te, ZnO, Ti
O _2, Si, CdS, and the like, a vapor deposition method, a sputtering method, the electrode layer by a CVD method or the like, 5 to 30 [mu] m, alone or mixed system, is laminated preferably in a thickness of 20 to 30 [mu] m. Further, the above-mentioned inorganic photoconductor as fine particles may be dispersed in an organic insulating resin such as a silicone resin, a polyester resin, 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, preferably 1 to 5 parts by weight, of the photoconductive fine particles are dispersed in 1 part by weight of the resin.

Further, the organic photoconductive substance includes a polymer photoconductive substance and a dispersion of a low molecular weight photoconductive substance in an insulating binder. As the polymer photoconductive substance, for example, polyvinylcarbazole (PVK), poly-N-ethylenically unsaturated group substitution containing allyl group or acryloxyalkyl group ethylenically unsaturated group instead of vinyl group in PVK There are carbazoles, poly-N-ethylenically unsaturated group-substituted phenothiazines such as poly-N-acrylphenothiazine and poly-N- (β-acryloxy) phenothiazine, and polyvinylpyrene. Above all, 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 and the like, triphenylmethane derivatives, hydrazone derivatives, butadiene derivatives, stilbene derivatives and the like. 1 part by weight is 0.1 to 5 parts by weight, preferably 0.1 to 1 part by weight of an electrically insulating resin such as a silicone resin, a polyester resin, a polycarbonate resin, a styrene-butadiene copolymer resin, a styrene resin or a polyvinyl acetal resin. It may be dispersed in parts by weight to form a film-forming organic photoconductive substance. The film thickness of these organic photoconductive substances after drying is 5 to 30 μm, preferably 10 to 30 μm.
m on the electrode.

Further, the organic photoconductive layer may optionally contain a persistent conductivity imparting agent described in Japanese Patent Application No. 4-287983. The above-mentioned organic photoconductive layer itself has a persistent conductivity, and this persistent conductivity imparting agent is added for the purpose of enhancing the persistent conductivity in the above-mentioned organic photoconductive layer. The persistent conductivity imparting agent is 0.001 to 1 part by weight with respect to 1 part by weight of the organic photoconductive substance,
Preferably 0.001 to 0.1 part by weight is added. If the added amount of the persistent conductivity imparting agent exceeds 1 part by weight,
This is not preferable because the amplification function of the photoconductive layer is significantly reduced. In addition, some persistent conductivity imparting substances do not have a spectral sensitivity in visible light, and when utilizing optical information in the visible light region, an electron-accepting substance is added to increase sensitivity in the visible light region. A dye or the like can be further added. Examples of the electron accepting substance include nitro-substituted benzene, diano-substituted benzene, halogen-substituted benzene, quinones and trinitrofluorenone. Examples of the sensitizing dye include triphenylmethane dye, pyrylium salt dye and xanthene dye. Electron-accepting substances, sensitizing dyes, etc.
It is added in an amount of 0.001 to 1 part by weight, preferably 0.01 to 1 part by weight, relative to 1 part by weight of the organic photoconductive substance. At the same time, when the optical information is in the infrared region, it is advisable to add a pigment such as phthalocyanine or the like, a pyrrole-based dye, a cyanine-based dye or the like in the same amount, and vice versa. 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 photoconductive layer and an organic material photoconductive layer. The charge generation layer in the inorganic system is formed by depositing Se—Te, Si doped with sulfur, oxygen, or the like on the electrode by a vapor deposition method, a sputtering method, a CVD method, or the like to have a film thickness of 0.05 μm to 1 μm. Then, as a charge transport layer, Se, As is formed on the charge generation layer.
₂ Se ₃ , Si, Si doped with methane or the like may be similarly laminated to have a film thickness of 10 μm to 50 μm.

Next, the charge generating layer in the organic system comprises a charge generating substance and a binder.
Fluorenone azo pigments, monoazo pigments, bisazo pigments, pyrrole pigments, azulenium salt pigments, phthalocyanine pigments, polycyclic aromatic pigments, pyrylium salt pigments, triazo pigments, squarylium salt pigments, perylene pigments , Antoanthrone pigments, cyanine pigments, polycyclic quinone pigments, imidazole pigments and the like, and specific examples thereof include the charge generating substances described in Japanese Patent Application No. 4-287983.

Examples of the binder include silicone resin, styrene-butadiene copolymer resin, epoxy resin, acrylic resin, saturated or unsaturated polyester resin, PMMA resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate mixed resin and the like. For example, the charge generation material is formed by dispersing it in a binder. The charge generating agent is preferably a fluorenone azo pigment or a bisazo pigment, and the binder is preferably a polyester resin or a vinyl chloride-vinyl acetate mixed resin. It is desirable that the charge generating agent and the binder are used in a mixing ratio of 0.1 to 10 parts by weight, preferably 0.1 to 1 part by weight, relative to 1 part by weight of the charge generating agent. The charge generation layer has a thickness after drying of 0.01 to 1 μm, preferably 0.1 to 1 μm.
0.3 μm is preferable.

The charge transport layer comprises a charge transport material and a binder. The charge transport material is a material having a good transport property of the charge generated by the charge generation material, and for example, a hydrazone-based material,
Pyrazoline-based, PVK-based carbazole-based, oxazole-based, triazole-based, aromatic amine-based, amine-based, triphenylmethane-based, butadiene-based, stilbene-based, polycyclic aromatic compound-based, etc. It is necessary to. Preferred are butadiene-based and stilbene-based charge transfer agents, and specifically, Japanese Patent Application No. 4-
The charge transport material described in Japanese Patent No. 287983 can be used.

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

Examples of combinations of these charge generating substances and charge transporting substances include a combination of fluorenone azo pigment (charge generating substance) and stilbene type charge transporting agent, bisazo type pigment (charge generating substance) and butadiene type, hydrazone type. The combination of the charge-transporting agents described above is preferable.

Further, the persistent conductivity imparting agent and the electron acceptor described in the section of the single-layer photoconductive layer are 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 an organic photoconductive layer, dichloroethane, 1,1,2-trichloroethane, monochlorobenzene, tetrahydrofuran, cyclohexane, dioxane, 1 , 2,3-trichloropropane, ethyl cellosolve, 1,1,1, -trichloroethane, methyl ethyl ketone, chloroform, toluene and the like may be used as a coating solution. The coating method may be a blade coating method, a dipping method, a spinner. A coating method and the like can be mentioned.

The photoconductive layer may be provided on the electrode via the charge injection control layer. The charge injection control layer is provided as needed, and is provided to control the charge injection property from the electrode to the photoconductive layer and adjust the voltage substantially applied to the information recording medium. However, in the information recording medium of the present invention, it is necessary to set the sensitivity of the photoconductive layer in the operating voltage region of the liquid crystal in the information recording layer. That is, the difference (contrast potential) between the potential (bright potential) applied to the information recording layer in the exposed portion and the potential (dark potential) applied to the information recording layer in the unexposed portion is made large in the liquid crystal operating region. Because it is necessary.

Therefore, for example, the dark potential applied to the liquid crystal layer in the unexposed portion of the photoconductive layer needs to be set to about the operation start potential of the liquid crystal, and 10 ⁵ V / cm to 10 V / cm to the bulk of the photoconductive layer.
10 ^-4 to 10 ^-8 A under an electric field of ⁶ V / cm
The conductivity is required to the extent that a dark current of / cm ² is generated, and the range of 10 ^-5 to 10 ^-6 A / cm ² is preferable.
In the photoconductive layer having a dark current of 10 ^-8 A / cm ² or less, the liquid crystal layer is not aligned even in the exposed state, and in the photoconductive layer having a dark current of 10 ^-4 A / cm ² or more, the voltage is applied even in the unexposed state. At the same time, a large amount of current flows, the liquid crystal in the information recording layer is not aligned, and even if it is exposed, the difference in its transmittance cannot be obtained. The charge injection control layer is appropriately provided in relation to the characteristics of such an information recording medium. When it is necessary to keep the dark potential in the photoconductive layer low, the charge injection control layer is a layer having a charge injection preventing property. There are two types of charge injection prevention layers, a layer utilizing a so-called tunneling effect and a layer utilizing a rectifying effect, and the one described in Japanese Patent Application No. 4-287983 can be used.

Next, the information recording layer 11 described in the section of the first information recording medium is laminated on the photoconductive layer 14 in the same manner as the first information recording medium.

In the information recording layer of the second information recording medium, 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 a sputtering method, the information recording layer has a high insulating property and has no noise when recording information.

For the electrode layers 13 and 13 ', the same material and forming method as those of the electrode layer in the above-mentioned first information recording medium can be adopted, but if the recorded information is read by transmitted light, it is transparent. Is required, and 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 either one of the electrode layers. A substrate may be laminated on the electrode 13 on the information recording layer.

Next, in this second information recording medium, a transparent insulating layer may be provided between the photoconductive layer 14 and the information recording layer 11. When the transparent insulating layer is provided, it is particularly suitable when the photoconductive layer is an organic photosensitive layer formed by using a solvent, and the liquid crystal in the information recording layer is eluted by the interaction between the photoconductive layer and the information recording layer. Alternatively, when the information recording layer is formed on the photoconductive layer by coating, the photoconductive material is eluted by the solvent for forming the information recording layer to prevent image unevenness. When forming the transparent insulating layer, it is necessary that it is not compatible with both the organic photoconductive layer forming material and the information recording layer forming material. Occurs, and the deterioration of resolution occurs, so insulation is required. However, since the transparent insulating layer lowers the distribution voltage applied to the liquid crystal layer or deteriorates the resolution, it is preferable that the film thickness is thin, and the thickness is preferably 2 μm or less.
In addition, the thinning causes not only the generation of image noise due to the interaction with time, but also the problem of penetration due to defects such as pinholes in the 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 film thickness of the material to be laminated and applied is appropriately set. Further, in order to prevent these problems, the following materials may be laminated and used. Further, in consideration of 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.

Such a transparent insulating layer is made of an inorganic material.
SiO ₂ , TiO ₂ , CeO ₂ , Al ₂ O ₃ , GeO ₂ , Si ₃ N ₄ , AlN, Ti
Alternatively, N ₂ , MgF ₂ , ZnS or the like may be used, and the layers may be laminated by a vapor deposition method, a sputtering method, a chemical vapor deposition (CVD) method, or the like. Further, an aqueous solution of polyvinyl alcohol, water-based polyurethane, water glass or the like may be used as a water-soluble resin having a low compatibility with an organic solvent, and 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 coated by a spin coating method, or laminated by a blade coating method, a roll coating method or the like. As the coatable fluorine resin, the fluorine resin described in Japanese Patent Application No. 4-24722 can be preferably used. When selecting a coating type transparent insulating material, the solvent does not dissolve the photoconductive layer, and does not dissolve in the material forming the information recording layer when forming the information recording layer by coating, or when applying It needs to be insoluble in the solvent.

Further, in the case of an organic material which is formed into a film in a vacuum system, there is no fear of dissolving the photoconductive layer during the film formation. Of these, polyethylene, polypropylene, poly (monochlorotrifluoroethylene), polytetrafluoroethylene, etc. can be used as the material for forming the film by the vapor deposition method.
As a material for forming a film by the CVD method, polyparaxylene specifically described in Japanese Patent Application No. 4-24722 can be used. If the photoconductive layer is made 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 transparent insulating layer.

Next, the third information recording medium of the present invention will be described. The third information recording medium is one in which an insulating light reflecting layer is provided between the photoconductive layer and the information recording layer in the second information recording medium, and the recorded information is read by reflected light.

Next, the method of recording information on the second information recording medium of the present invention will be described with reference to FIG.

First, when the information light 18 is incident while a voltage is applied between the electrodes 13 and 13 'by the power source, the photo carriers generated in the photoconductive layer 14 at the portion where the light is incident are formed by both electrodes. By moving by the electric field and redistributing the voltage, 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 the applied voltage time, the voltage distribution in the information recording medium is appropriately set, and the voltage distribution applied to the information recording layer is determined by the operation of the liquid crystal. It is recommended to set it in the voltage range.

This information recording method enables planar analog recording and obtains high resolution because recording can be performed at the liquid crystal particle level, and the exposure pattern is retained as a visible image due to the orientation of the liquid crystal phase. To be done. Further, as the information input method, the same method as the method using the camera and the method described with the laser described in the section of the first information recording medium can be used. Further, the recording method using a laser can be similarly performed. Further, the spectral characteristics of the photoconductive layer do not need to be panchromatic, and may be sensitive to the wavelength of the laser light source. The information recorded on the second information recording medium is reproduced in the same manner as in the case of the first information recording medium shown in FIG. 3 when reading with transmitted light, and also when reading with reflected light. It is the same.

FIG. 1C is a diagram for schematically explaining the cross section, in which 3 is an information recording medium, 11 is an information recording layer, 12 is an insulating light reflecting layer, and 13 and 13 'are. Electrode layer, 1
4 is a photoconductive layer, and 15 is a substrate.

Information recording layer 1 in third information recording medium
1. The photoconductive layer 14 is the same as that of the second information recording medium described above. It is necessary that the electrode layers 13, 13 'and the substrate 15 are transparent.

As the insulating light reflecting layer laminated on the information recording layer or the photoconductive layer, for example, a dielectric mirror layer,
Examples thereof include 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 vapor-deposited at a rate of 50 Å / sec and a germanium vapor-deposition rate of 20 Å / As one second, a film having a film thickness of about 1 μm can be given by vapor deposition at the same time.

The information recorded on the third information recording medium is
It is read by reflected light from the information recording layer side.

In each of the first to third information recording media of the present invention, a primer layer is provided between the respective layers such as the electrode layer, the light reflection layer or the light reflection prevention layer, and the substrate to improve the adhesion. 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 made of an ionizing radiation curable resin such as a thermoplastic resin, a thermosetting resin, or an ultraviolet curable resin. It may be formed by applying a resin, or in the case of a combination of an inorganic material and an organic material, a known silane coupling agent, an organotitanium compound, an organoaluminum compound or other organometallic 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. Since the voltage applied to the information recording layer can be controlled by improving the adhesion and changing the film thickness, the recordable exposure range can be controlled.

Further, the first to third information recording media of the present invention are used by being cut in the layer width direction into an appropriate size according to the mode of use, and the information recording is made at the cut surface. The inside of the layer is exposed, and the liquid crystal phase exudes during storage. When this bleeding phenomenon occurs, a problem arises in that when information is recorded, accurate information cannot be recorded at the edge of the information recording medium. In order to prevent this, after cutting the information recording medium into an appropriate shape, a resin layer may be similarly laminated on the cut surface by the coating method or the laminating method to protect the cut surface.

The first to third information recording media of the present invention record electrostatic information in a state where the electrostatic information is visualized by the orientation of the liquid crystal. However, by selecting the combination of the liquid crystal and the resin, Oriented and visualized information is not erased, and a memory property is provided. To erase the memory, it is preferable to heat it to a high temperature near the isotropic phase transition, and it can be used again for information recording.

[0084]

The first information recording medium of the present invention can be an information recording medium having high sensitivity and high contrast by setting the average film thickness of the information recording layer to 1 μm to 30 μm. In particular, when the film thickness is 5 μm to 10 μm, the operating voltage can be lowered while maintaining high sensitivity and high contrast. The thickness of the skin layer in the information recording layer is 0.01% to 30% of the thickness of the information recording layer.
When the ratio is set to, the liquid crystal does not seep out from the surface, it is possible to perform information recording without noise, and the content ratio of the liquid crystal can be increased to 40% by weight to 80% by weight. The information recording medium can have high sensitivity and high contrast, and the operating voltage can be lowered.

Further, in the second information recording medium, since the liquid crystal bleeding phenomenon does not occur on the surface of the information recording layer, an electrode layer can be provided on the surface by a sputtering method or the like, and the electrode is cracked or the like. Therefore, the conductivity of the electrode layer is not lowered. In addition, there is no noise during information recording, and the information recording layer can have a high resistance. Further, since it has a photoconductive layer, it is not necessary to combine it with an optical sensor, and information can be recorded by itself.

The third information recording medium may be suitable for reading recorded information by reflected light.

Further, in the first to third information recording media of the present invention, since the information recording layer can be uniformly thinned by the coating technique, a large area information recording medium can be manufactured,
Moreover, since information can be recorded at the liquid crystal molecule level, a high-resolution image can be recorded. Hereinafter, examples will be described. In the examples, “parts” means parts by weight and “%” means% by weight.

[0088]

Example 1 An indium tin oxide (ITO) film having a film thickness of 1000 Å was formed on a thoroughly washed glass substrate having a thickness of 1.1 mm by a sputtering method to obtain an electrode layer. On the electrode, 40 parts of a polyfunctional monomer (dipentaerythritol hexaacrylate, manufactured by Toagosei Co., Ltd., M-400, molecular weight / functional group = 117), a photocuring initiator (2-hydroxy-2-methyl-) 1-phenylpropan-1-one, 2 parts by Ciba-Geigy: trade name Darocur 1173, 60 parts by smectic liquid crystal (BDH: S-6), surfactant (Sumitomo 3M: trade name) Florard FC-
430) 3 parts of 3 parts was uniformly dissolved in 105 parts of xylene (manufactured by Junsei Kagaku Co., Ltd., special grade reagent) using a blade coater, and this was immediately dried at 50 ° C. for 3 minutes and then at 50 ° C.
After drying under reduced pressure for 3 minutes, immediately 600 mJ / cm ²
Is irradiated with the UV light of, the film thickness is 6 μm, and the surface roughness R
An information recording layer of a = 50Å was formed to obtain the first information recording medium of the present invention. The transmittance of 633 nm light of this information recording medium was 40%.

Further, the cut surface of the obtained information recording layer was extracted with hot methanol to dry the liquid crystal, and then dried, and then a scanning electron microscope (S-800, 100 manufactured by Hitachi, Ltd.).
The internal structure of the layer was observed to be 0.
It was found that the structure was covered with an ultraviolet curable resin having a thickness of 6 μm (10% of the film thickness), and the inside of the layer was filled with resin particles having a particle diameter of 0.1 μm.

(Production of optical sensor) -The following structure as a charge generating agent

[0091]

[Chemical 1]

Using 3 parts of a fluorenone azo pigment (manufactured by Nippon Senshoku Co., Ltd.) having 1 part, a polyester resin (manufactured by Toyobo Co., Ltd., Byron 200), and a mixed solvent of 1,4-dioxane: cyclohexanone = 1: 1, A 100 g solution with a solid content of 2% was sufficiently dispersed with a paint shaker to form a coating solution, and an IT having a film thickness of 500 Å and a resistance value of 80 Ω / cm ²
It is applied to the ITO side of the glass substrate having the O film using a blade coater with a gap of 2 mils, and the temperature is 100 ° C.
After drying for an hour, a charge generation layer having a thickness of 0.3 μm was laminated.

On the charge generation layer, the following structure was used as a charge transfer agent.

[0094]

[Chemical 2]

25 parts of para-dimethyl stilbene, 5 parts of polystyrene resin (HRM-3 manufactured by Denka), 1,
1,2-trichloroethane 102 parts, dichloromethane 6
8 parts of the coating solution is applied using a blade coater, dried at 80 ° C. for 2 hours, and a charge transport layer is laminated to form a photoconductive layer having a thickness of 20 μm and including a charge generation layer and a charge transport layer. Layers were applied to obtain a light sensor.

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 PET film of 10 μm as a spacer, and incorporated in the recording apparatus of FIG. Was positive and the information recording medium side was negative, and a DC voltage of 800 V was applied. With the voltage applied, exposure was performed from the photosensor side using a halogen lamp with an illuminance of 1000 lux as a light source for 0.1 seconds, and after the exposure was completed, the information recording medium was taken out and the information recording was completed. The exposed area becomes transparent and the transmittance of this area becomes 80%.
The contrast ratio was excellent.

Further, an ordinary camera was used as an exposure method, and an object was photographed outdoors and in the daytime with an exposure f = 1.4 and a shutter speed of 1/60 seconds under a voltage application of 600V. When the information recording medium was taken out after the exposure, it was possible to see through an image having no noise and gradation. Further, as a result of reading this information recording medium with a scanner using a CCD line sensor and further outputting with a sublimation printer, a hard copy having gradation and high resolution was obtained.

On the surface of the information recording layer of the information recording medium manufactured as described above, an I film having a film thickness of 500Å is formed as an upper electrode.
When the TO film was formed by the sputtering method, good film formation was possible. A lead wire was attached between both electrodes, and a voltage of 400 V DC was applied to the terminals for 0.1 second. The transmittance for light of 633 nm was 40% before the voltage was applied, but it was 90% after the voltage was applied.

[0099]

Example 2 An indium tin oxide (ITO) film having a film thickness of 1000 Å was formed on a thoroughly washed glass substrate having a thickness of 1.1 mm by a sputtering method to obtain an electrode layer. On the electrode: -Polyfunctional monomer (trimethylolpropane triacrylate acrylate, manufactured by Nippon Kayaku Co., TMPTA) 40
Part: 2 parts of a photo-curing initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by Merck: product name Darocur 1173), 2 parts of smectic liquid crystal (manufactured by BDH: S-6) 60 Part, ・ Surfactant (Sumitomo 3M: Trade name Florard FC-
430) 3 parts of xylene (manufactured by Junsei Kagaku Co., Ltd., special grade reagent) was uniformly dissolved, and the solution was applied using a blade coater, dried at 50 ° C. for 3 minutes, and then at 50 ° C. for 3 minutes. After drying under reduced pressure, UV light of 600 mJ / cm ^{2 was} immediately irradiated to obtain a first information recording medium of the present invention having a film thickness of 6 μm and a transmittance of 40% for light of 633 nm.

The cut surface of the obtained information recording layer was extracted with hot methanol to dry the liquid crystal, and dried, and then a scanning electron microscope (S-800, 100 manufactured by Hitachi, Ltd.).
The internal structure of the layer was observed to be 0.
Covered with 3 μm thick (5% of film thickness) UV curable resin,
Inside the layer, the particle size is about 0.1 μm in the continuous liquid crystal phase.
It was found that it had a structure filled with the resin particles.

This information recording medium and the optical sensor prepared in Example 1 were arranged facing each other with a PET film of 10 μm as a spacer as in Example 1, and incorporated in the recording apparatus of FIG. A DC voltage of 700 V was applied with the positive side and the information recording medium side as the negative side. With the voltage applied, exposure was performed from the photosensor side using a halogen lamp with an illuminance of 1000 lux as a light source for 0.1 seconds, and after the exposure was completed, the information recording medium was taken out and the information recording was completed. The exposed area becomes transparent and the transmittance of this area becomes 90%.
The contrast ratio was excellent.

An ordinary camera was used as the exposure method, and with an applied voltage of 700 V, the illuminance was 2000 lux from the optical sensor side, exposure f = 4, shutter speed 1
The subject was photographed at / 30 seconds. When the information recording medium was taken out after the exposure, it was possible to see through an image having no noise and gradation. Further, this information recording medium is read by a scanner using a CCD line sensor, and further,
As a result of outputting with a sublimation printer, a high-resolution hard copy having gradation was obtained.

On the surface of the information recording layer of the information recording medium manufactured as described above, an I film having a film thickness of 500Å is formed as an upper electrode.
When the TO film was formed by the sputtering method, good film formation was possible. A lead wire was attached between both electrodes, and a voltage of 400 V DC was applied to the terminals for 0.1 second. The transmittance for light of 633 nm was 40% before the voltage was applied, but was 80% after the voltage was applied.

[0104]

Example 3 An aluminum film having a film thickness of 1000Å was formed by vapor deposition on a glass substrate having a thickness of 1.1 mm that had been thoroughly washed to obtain an electrode layer. An information recording layer was laminated on this electrode layer in the same manner as in Example 1 to produce a first information recording medium of the present invention, and after information recording was performed in the same manner as in Example 1, information was reflected by reflected light. Was reproduced, a hard copy similar to the medium of Example 1 was obtained.

[0105]

Example 4 Fluorine-containing resin CYTOP (trade name; Asahi Glass) on the photoconductive layer of the optical sensor prepared in Example 1.
Co., Ltd., water absorption 0.01%, specific resistance 1 × 10 ¹⁸ Ω · c
m) perfluoro (2-butyltetrahydrofuran)
Dissolve in, and the 4.5% solution is 1500r with a spinner.
pm, apply for 20 seconds, dry at 80 ° C for 1 hr,
A transparent insulating layer having a film thickness of 1 μm was formed.

Then, an information recording layer having a thickness of 6 μm was formed on the transparent insulating layer as in Example 1, and an ITO film having a film thickness of 500 Å was formed as an upper electrode on the information recording layer by sputtering. Then, the second information recording medium of the present invention was produced.

This information recording medium, as shown in FIG.
The photoconductive layer side electrode is positive and the information recording layer side electrode is negative 60
A DC voltage of 0V was applied. Exposure with a halogen lamp having an illuminance of 1000 lux as a light source was performed for 0.1 seconds from the side of the photoconductive layer while a voltage was applied, and after completion of the exposure, the information recording medium was taken out.

The information recording medium before information recording is 800 nm.
The light transmittance was 60%, but it was 90% after information recording.
%, And there was contrast.

As an exposure method, an ordinary camera was used, and an exposure using a halogen lamp with an illuminance of 2000 lux as a light source was applied from the photoconductive layer side under a voltage application of 700 V. Exposure f = 4, shutter speed 1/30 The subject was photographed in seconds. When the information recording medium was taken out after the exposure, it was possible to see through an image having no noise and gradation.
Further, as a result of reading this information recording medium with a scanner using a CCD line sensor and further outputting with a sublimation printer, a hard copy having gradation and high resolution was obtained.

[0110]

[Example 5] Fluorine-containing resin CYTOP (trade name; Asahi Glass) on the photoconductive layer of the optical sensor prepared in Example 1.
Co., Ltd., water absorption 0.01%, specific resistance 1 × 10 ¹⁸ Ω · c
m) perfluoro (2-butyltetrahydrofuran)
Dissolve in, and the 4.5% solution is 1500r with a spinner.
pm, apply for 20 seconds, dry at 80 ° C for 1 hr,
A transparent insulating layer having a film thickness of 1 μm was formed.

Then, an information recording layer having a thickness of 6 μm was formed on the transparent insulating layer as in Example 2, and an ITO film having a film thickness of 500 Å was formed as an upper electrode on the information recording layer by sputtering. Then, the second information recording medium of the present invention was produced.

This information recording medium, as shown in FIG.
The photoconductive layer side electrode is positive and the information recording layer side electrode is negative 60
A DC voltage of 0V was applied. Exposure with a halogen lamp having an illuminance of 1000 lux as a light source was performed for 0.1 seconds from the side of the photoconductive layer while a voltage was applied, and after completion of the exposure, the information recording medium was taken out.

The information recording medium before information recording had a transmittance of light of 800 nm of 65%, but after information recording it had a transmittance of 80%.
And there was contrast.

As an exposure method, an ordinary camera is used, and an exposure using a halogen lamp having an illuminance of 2000 lux as a light source is exposed from the photoconductive layer side with a voltage of 700 V applied, and the exposure is f = 4 and the shutter speed is 1/30. The subject was photographed in seconds. When the information recording medium was taken out after the exposure, it was possible to see through an image having no noise and gradation.
Further, as a result of reading this information recording medium with a scanner using a CCD line sensor and further outputting with a sublimation printer, a hard copy having gradation and high resolution was obtained.

[0115]

Example 6 Zinc sulfide and magnesium fluoride were deposited on the photoconductive layer of the optical sensor prepared in Example 1 to give a film thickness λ.
/ 4n (light wavelength read out at λ = 370 nm, n is the refractive index, zinc sulfide is 2.38, and magnesium fluoride is 1.38, so zinc sulfide is 39 nm, magnesium fluoride is 67 nm) Then, six layers were alternately laminated by the EB vapor deposition method, and finally zinc sulfide was laminated to a film thickness of λ / 2 to form a dielectric mirror layer.

Then, an information recording layer having a thickness of 6 μm was laminated on this dielectric mirror layer as in Example 1, and further an ITO film having a film thickness of 500 Å was formed as an upper electrode by a sputtering method to form a third embodiment of the present invention. An information recording medium is manufactured and the applied voltage is 650V.
Information recording was performed in the same manner as in Example 3 except that the reflected light was used to reproduce an image having no noise and gradation, and a high-resolution hard copy similar to that in Example 3 was obtained. It was

[0117]

[Comparative Example 1] An indium tin oxide (ITO) film having a film thickness of 1000 Å was formed by a sputtering method on a glass substrate having a thickness of 1.1 mm and thoroughly washed to obtain an electrode layer. On the electrode, 40 parts of a polyfunctional monomer (dipentaerythritol hexaacrylate, manufactured by Toagosei Co., Ltd., M-400, molecular weight / functional group = 117), a photocuring initiator (2-hydroxy-2-methyl-) 1-phenylpropan-1-one, 2 parts by Ciba-Geigy: trade name Darocur 1173, 60 parts by smectic liquid crystal (BDH: S-6), surfactant (Sumitomo 3M: trade name) Florard FC-
430) 3 parts of 3 parts was uniformly dissolved in 105 parts of xylene (manufactured by Junsei Kagaku Co., Ltd., special grade reagent) using a blade coater, and this was immediately dried at 50 ° C. for 3 minutes and then at 50 ° C.
After drying under reduced pressure for 3 minutes, immediately 600 mJ / cm ²
Was irradiated with UV light to form an information recording layer having a film thickness of 60 μm to obtain an information recording medium. 633 of this information recording medium
The transmittance for nm light was 5%.

Then, as shown in FIG. 4, a DC voltage of 600 V was applied with the photoconductive layer side electrode being positive and the information recording layer side electrode being negative. Illuminance of 10 from the photoconductive layer side when voltage is applied.
The exposure using a halogen lamp of 00 lux as a light source is set to 0.
The operation was performed for 1 second, and after the exposure was completed, the information recording medium was taken out. When the transmittance of 633 nm light was measured for the recording portion of this information recording medium, it was modulated only to 7%, and the contrast was hardly obtained.

[0119]

[Comparative Example 2] An indium tin oxide (ITO) film having a film thickness of 1000 Å was formed by a sputtering method on a sufficiently washed glass substrate having a thickness of 1.1 mm to obtain an electrode layer. On the electrode, 40 parts of a polyfunctional monomer (dipentaerythritol hexaacrylate, manufactured by Toagosei Co., Ltd., M-400, molecular weight / functional group = 117), a photocuring initiator (2-hydroxy-2-methyl-) 1-phenylpropan-1-one, 2 parts by Ciba-Geigy: trade name Darocur 1173, 60 parts by smectic liquid crystal (BDH: S-6), xylene (manufactured by Junsei Kagaku Co., Ltd., reagent special grade) ) A solution in which 102 parts are uniformly dissolved is applied using a blade coater, immediately dried at 50 ° C. for 3 minutes, and then 50 ° C.
After drying under reduced pressure for 3 minutes, immediately 600 mJ / cm ²
However, the liquid crystal phase was solidified into particles and could not be used as an information recording medium.

[Brief description of drawings]

FIG. 1 is a schematic view showing a cross section of an information recording medium of the present invention, where (a) is a first information recording medium, (b) is a second information recording medium, and (c) is a first information recording medium. The section of the information recording medium of No. 3 is shown.

FIG. 2 is a schematic diagram of an information recording device using an optical sensor.

FIG. 3 is a diagram for explaining a method of reproducing recorded information on an information recording medium with transmitted light.

FIG. 4 is a diagram for explaining an information recording method on a second information recording medium.

[Explanation of symbols]

1 is an optical sensor, 3 is an information recording medium, 11 is an information recording layer, 12 is an insulating light reflecting layer, 13 and 13 'are electrode layers, 1
4 is a photoconductive layer, 15 is a substrate, 18 is information light, 19 is a spacer, 21 is a light source, 22 is a shutter having a drive mechanism, 23 is a pulse generator (power source), 24 is a dark box, A is transmitted light, B is It is scattered light.

Claims (8)

[Claims] 1. An information recording medium having an information recording layer comprising a liquid crystal phase and a resin phase on an electrode layer, wherein the information recording layer is a mixed solution of liquid crystal, an ultraviolet curable resin forming material and a fluorine-based surfactant. Is applied to the electrode layer and then cured by irradiation with ultraviolet rays, and the outer surface of the electrode layer is formed into a skin layer made of only an ultraviolet curable resin, and the information recording layer is
An information recording medium having a thickness of μm to 30 μm, and a thickness of the skin layer being in the range of 0.01% to 20% with respect to the thickness of the information recording layer. 2. The information recording medium according to claim 1, wherein the electrode layer is light reflective or a light reflective layer is laminated on the electrode layer. 3. An information recording medium having an electrode layer, a photoconductive layer, an information recording layer, and an electrode layer sequentially provided, at least one electrode of which is transparent, and the information recording layer is a liquid crystal or an ultraviolet curable resin forming material. And a mixed solution of a fluorine-based surfactant on the electrode layer and then cured by irradiation with ultraviolet rays, and the outer surface of the electrode layer is formed into a skin layer consisting only of an ultraviolet curable resin, and the information recording layer is 1 μm. An information recording medium having a thickness of ˜30 μm, and a thickness of the skin layer being in the range of 0.01% to 20% with respect to the thickness of the information recording layer. 4. An information recording medium in which a transparent electrode layer, a photoconductive layer, an insulating light reflecting layer, an information recording layer and a transparent electrode layer are sequentially provided, wherein the information recording layer is a liquid crystal, an ultraviolet curable resin forming material and fluorine. After coating a mixed solution with a surface-active agent on the electrode layer, the electrode layer is cured by irradiation with ultraviolet rays, and the outer surface thereof is formed into a skin layer made of only an ultraviolet curable resin, and the information recording layer is 1 μm to 30 μm. And the thickness of the skin layer is 0.01 with respect to the thickness of the information recording layer.
% To 20% of the information recording medium. 5. The information recording medium according to claim 1, wherein the liquid crystal in the information recording layer has a memory property. 6. The content ratio of liquid crystal in the information recording layer is
40% to 80% by weight based on the total amount of liquid crystal and resin
The information recording medium according to any one of claims 1 to 5, wherein 7. The information recording medium according to claim 1, wherein the thickness of the information recording layer is 5 μm to 10 μm. 8. The thickness of the skin layer in the information recording layer is
The information recording medium according to any one of claims 1 to 7, wherein the ratio is 0.01% to 30% of the thickness of the information recording layer.