JP3528938B2 - Information recording medium - Google Patents

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 more particularly to an information recording medium having excellent resolution.

[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 an electrode are arranged facing each other on the optical axis. Information recording / reproduction in which exposure is performed while applying voltage between electrode layers, the liquid crystal layer is oriented by the electric field formed by the optical sensor to record information, and when reproducing information, it is reproduced as visible information by transmitted light or reflected light. The method was previously filed as Japanese Patent Application No. 4-3394, Japanese Patent Application No. 4-24580, Japanese Patent Application No. 4-24722, and Japanese Patent Application No. 5-266646. This information recording / reproducing method makes it possible to visualize recorded information without using a deflector.

In such an information recording medium, smectic liquid crystals are preferably used as the liquid crystal substance from the viewpoint of recording property, but there is a problem that the resolution is deteriorated depending on the type of liquid crystal. .

[0004]

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide an information recording medium having high resolution in an information recording medium using a polymer dispersed liquid crystal as an information recording layer and using smectic liquid crystal as the liquid crystal. To do.

[0005]

A first information recording medium of the present invention is an information recording medium having an information recording layer comprising a smectic liquid crystal phase and a resin phase on an electrode layer, the information recording layer being driven. A liquid crystal in which a nematic liquid crystal is mixed with a smectic liquid crystal having a voltage of at least 100 V is 10 to
It contains 53% by weight and has a film thickness of 1 to 30 μm,
The surface of the information recording layer has a thickness of 0.01-50.
%, The inside of the skin layer is filled with resin particles having a primary particle diameter of 0.03 to 0.3 μm, and a liquid crystal phase is in communication between them. In the voltage-current characteristics shown when a slope voltage of 500 V is applied for 0.1 seconds in the direction, the current value for the applied voltage equal to or lower than the driving voltage is 7.0 × 10 ⁻⁶ A / cm ² or less. It is characterized by being a thing.

A second information recording medium of the present invention is an electrode layer,
An information recording medium in which 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 has a driving voltage of at least 1
It contains 10 to 53% by weight of a liquid crystal in which a nematic liquid crystal is blended with a smectic liquid crystal of 00 V or more, and has a thickness of 1 to 30 μm.
A skin layer having a thickness of m and a thickness of 0.01 to 50% of the thickness of the information recording layer is formed on the surface of the information recording layer, and the inside has a primary particle diameter of 0.03. In the voltage-current characteristics shown when a slope voltage of 500 V is applied to the film thickness direction for 0.1 second in a film thickness direction, the liquid crystal phase is filled with resin particles of 0.3 μm. Current value for applied voltage below drive voltage is 7.0 × 10 ^-6
It is characterized by showing a value of A / cm ² or less.

FIG. 1 is a diagram for schematically explaining a cross section of a first information recording medium of the present invention. In the figure, 3 is an information recording medium, 11 is an information recording layer, 13 is an electrode layer, and 15 is a substrate. Is.

The information recording layer 11 is composed of a liquid crystal phase and a resin phase, and the liquid crystal phase has a driving voltage of at least 10%.
It is made of a smectic liquid crystal of 0 V or more, and retains the recording property, that is, the orientation of the liquid crystal, and retains information permanently.
It has a so-called memory property. From the viewpoint of improving the memory property, nematic liquid crystal may be appropriately blended, and cholesteric liquid crystal may be used instead of smectic liquid crystal.

Examples of such smectic liquid crystals include cyanobiphenyl-based, cyanoterphenyl-based, phenylester-based compounds having a long carbon chain at the terminal group of a substance exhibiting liquid crystallinity,
Further, a liquid crystal substance exhibiting a smectic A phase such as a fluorine-based substance, a liquid crystal substance exhibiting a smectic C phase used as a ferroelectric liquid crystal, or a liquid crystal substance exhibiting smectic H, G, E, F or the like can be given.

The nematic liquid crystal can improve the memory property by being mixed with the smectic liquid crystal. For example, a Schiff base type, an azoxy type, an azo type, a benzoic acid phenyl ester type, a cyclohexyl acid phenyl ester type, a biphenyl type. System, terphenyl system, phenylcyclohexane system, phenylpyridine system, phenyloxazine system, polycyclic ethane system, phenylcyclohexene system,
Known nematic liquid crystals such as cyclohexylpyrimidine type, phenyl type and tolan type can be used. Further, a microcapsule obtained by mixing a liquid crystal material with polyvinyl alcohol or the like can also be used.

Next, as a material for forming a 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 Examples thereof include copolymers containing these as main constituents, epoxy resins, silicone resins, and UV-curable resins. It is preferably an ultraviolet curable resin, and the case where the ultraviolet curable resin is used as the resin phase will be described.

The UV-curable resin is a monomer or oligomer which is compatible with the liquid crystal at room temperature or by heating, or a monomer or oligomer in a solvent common to the liquid crystal material at room temperature or by heating. Those having compatibility are listed. Examples of the ultraviolet curable resin include acrylic acid ester and methacrylic acid ester, and in a monomer or oligomer state, for example, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, Polyfunctional monomers such as isocyanuric acid (ethylene oxide modified) triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetraacrylate, neopentyl glycol diacrylate, hexanediol diacrylate, etc. or polyfunctional urethane-based, ester-based oligomers, and nonylphenol Modified acrylate, N-vinyl-2-pyrrolidone, 2-hydroxy-3-phenoxypropyl ac Monofunctional monomer or oligomer rate and the like.

The common solvent for the liquid crystal and the UV-curable resin monomer is a solvent having a relative evaporation rate of less than 2 with respect to -n-butyl acetate, and the liquid crystal, the UV-curable resin forming material, the photocuring agent, and the fluorine-based interface are used. It must be a common solvent for each of the activators. 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.

As the photo-curing agent, for example, 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 111 manufactured by Ciba Geigy”)
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
-On is particularly preferable in terms of compatibility.

Further, in addition to the wettability of the information recording layer with respect to the electrode layer, a fluorine-based 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 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.

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 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. Further, 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 liquid crystal content can be increased to 40% to 80% by weight and the high sensitivity,
The information recording medium can have a high contrast and 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.

Next, as a method for forming the information recording layer, liquid crystal, an ultraviolet curable resin monomer, a photopolymerization initiator and a surfactant are mixed with a solvent having a relative evaporation rate of less than 2 with respect to -n-butyl acetate. , Solid content concentration of 10 to 60% by weight
And the mixed solution. Solvent dilution is 1 to 500 cps
(20 ° C), preferably 10 to 200 cps (20 ° C)
Is. 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 higher than the temperature at which the liquid crystal retains an isotropic phase, preferably within a temperature range of the isotropic phase transition point + 10 ° C. to dissolve the liquid crystal, and the mixed solution is spin-coated on the electrode layer under a room temperature condition or a bar coat , Blade coater,
Alternatively, it is applied uniformly with a uniform film thickness by a coating method such as a roll coater.

Next, the dried coating layer is irradiated with ultraviolet rays using a UV lamp to be cured. When the coating layer is irradiated with ultraviolet rays, the infrared rays are shielded to 200 n.
An information recording layer excellent in phase separation between a liquid crystal phase and a resin phase can be obtained by using ultraviolet rays having a wavelength portion of m 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 5% 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. Further, when the ultraviolet curable resin monomer represented by the above general formulas (1) and (2) 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 liquid crystal in the information recording layer, and there is no seepage of liquid crystal on 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, 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.

The average film thickness of the information recording layer is 1 μm to 30 μm.
m. If the film thickness is too thick, the operating voltage will increase,
Generally, the film thickness should be thinned to increase the sensitivity, and the film thickness should be increased to increase the contrast. The film thickness is preferably 3 μm to 20 μm, and more preferably 5 in order to have excellent sensitivity and contrast ratio.
It is preferable that the film thickness is 10 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, the liquid crystal oozes out and the optical sensor described later is used. Therefore, even if information is recorded, 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 irradiation amount of ultraviolet rays, 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 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. Easily, with high sensitivity,
Moreover, it is possible to easily provide an information recording body having a high contrast ratio.

A skin layer may be formed on the surface of the information recording layer of the present invention to prevent liquid crystal from seeping out. Thermoplastic resin film, thermosetting resin film,
An ionizing radiation curable resin film such as an ultraviolet curable resin may be laminated by a coating method.

As a material for forming these resin layers, particularly preferable are polyethylene terephthalate, polyethylene, polypropylene, ultraviolet ray and electron beam curable resins and the like, and a hard coat layer having a high surface hardness even when formed into a thin film. Therefore, the durability of the information recording medium can be improved. The thickness of the resin layer is 0.1 μm to 20 μm.
m, 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 on 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. 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 a light reflecting layer may be laminated on the transparent electrode 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 reproducing information with transmitted light, whether a layer having an antireflection effect is laminated on the substrate as necessary, or whether the transparent substrate is adjusted to a film thickness capable of exhibiting the antireflection effect. The antireflection property may be imparted by further combining the two.

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.

The photosensor is formed by laminating an electrode layer and a photoconductive layer on a transparent substrate, and the photoconductive layer is a single layer system having a charge generating function and a charge transporting function depending on information light. And a laminated system 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) in the irradiated portion when irradiated with light, and these carriers can move in the layer width. When present, the effect is significant.

The single-layer photoconductive layer is formed of an inorganic photoconductive substance or an organic photoconductive substance. Examples of the inorganic photoconductive substance include Se, Se—Te, ZnO, TiO ₂ , and S.
i, CdS, etc., for example, vapor deposition method, sputtering method, CVD
On the electrode layer by a method or the like, alone or in a mixed system of 5 to 30 μm.
m, preferably 20 to 30 μm. 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.

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 an ethylenically unsaturated group such as an allyl group or an acryloxyalkyl group instead of the 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, a triphenylmethane derivative, a hydrazone derivative, a butadiene derivative, a stilbene derivative, 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.

If desired, the organic photoconductive layer may 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 a fluorenone azo pigment (charge generating substance) and a stilbene type charge transporting agent, a bisazo type pigment (charge generating substance) and a butadiene type, a 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 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 ⁵ V / cm is applied 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.

In the optical sensor described in this publication, the electric field or the amount of electric charge applied to the information recording medium during light irradiation is amplified as the light is irradiated, and when the voltage is continuously applied even after the light irradiation is finished, It has the function of maintaining conductivity and continuously applying an electric field or an amount of 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 incident from the light source 21 while applying a voltage between the electrodes 13 and 13 'by the pulse generator 23, the photo carriers generated in the photoconductive layer 14 at the portion where the light is 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 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 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 information is reproduced by the transmitted light, the electrostatic information recorded on the information recording medium is transmitted through the light A 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.

The present invention provides an information recording medium having an information recording layer formed in this way and having information recorded thereon,
The information recording layer has a specific voltage-current characteristic. The voltage-current characteristics of the information recording layer will be described below.

FIG. 4 is a diagram for measuring the voltage-current characteristics in the information recording layer, where 30 is an electrode, 100 is an ammeter, and 101 is a power source, and the same symbols as in FIG. 1 indicate the same contents. The measurement sample is prepared by forming the electrode 13 and the information recording layer 11 on the support 15 in this order, and then forming the electrode 30 on the information recording layer 11 by vapor deposition of gold.

As shown in the figure, a voltage applying power source 101 and an ammeter 1 are provided between both electrodes 13 and 30 of this measurement sample.
00 is connected, but the voltage applied by the power supply 101 is a slope voltage of 500 V in 0.1 seconds as shown in FIG. 5, and the current value corresponding to the voltage between them is measured by an ammeter. Is.

In an information recording medium having a liquid crystal phase of smectic liquid crystal, the driving voltage is usually 100 V or more, and the obtained voltage-current characteristics are typically as shown in FIG. It comprises a maximum peak section b section, a section a before the maximum peak section b section in the low voltage section, and a section c after the maximum peak section b section in the high voltage section.

The present inventors have found that in the information recording layer formed by the above method, the current value in the section a before the maximum peak section b differs depending on the mixing ratio of the liquid crystal, the ratio of the liquid crystal to the resin, and the like. It was found that this current value affects the resolution as an information recording medium.

The information recording layer in the information recording medium of the present invention is composed of a smectic liquid crystal phase and a resin phase, and in terms of a circuit, as shown in FIG. 7, the current value has an electric resistance portion R and an electric capacitance portion C. Although schematically shown by both, in the voltage-current characteristics shown in FIG. 6, it is considered that the section a is due to the current increase due to the resistance portion and the section b is due to the current increase due to the capacitance change due to the alignment of the liquid crystal. The initial voltage value b ¹ corresponds to the drive voltage (threshold value) in the information recording layer.

In the case of the smectic liquid crystal, the driving voltage is generally 100 V or more, and therefore, as a step before the section b which is the maximum peak portion, a certain section a until the driving voltage (threshold b ¹ ) is reached. At, a substantially constant current value is maintained. Then, a certain relationship is recognized between the magnitude of the current value and the drive voltage (threshold value) in the section a.

In the present invention, in the voltage-current characteristics shown in FIG. 6, the current value in the section a is 10 ⁻⁶ A / cm ²
It has been found that the information recording medium has excellent resolution as described below. That is, in the present invention,
A liquid crystal material, a resin or the like forming material in the information recording layer, a mixing ratio thereof, a manufacturing method of the information recording layer, a film thickness and the like are appropriately selected, and the information recording layer is adjusted to 5 in 0.1 seconds in the film thickness direction.
By setting the current value before the transition to the maximum peak portion in the voltage-current characteristics shown when a slope voltage of 00 V is applied to a value of 7.0 × 10 ⁻⁶ A / cm ² or less, Although the detailed reason is unknown, it can be regarded as an information recording medium having excellent resolution.

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. 8A 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, and 15 is a photoconductive layer.
Is the substrate.

Photoconductive layer 14 laminated on electrode 13 '
Is the same as 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 provided on the photoconductive layer as the first information recording medium. It is laminated in the same manner.

Further, according to the above-described method for forming the first information recording layer, it is possible to prevent the liquid crystal from seeping out from the surface of the information recording layer. Therefore, the electrode layer 1 is directly formed on the surface of the information recording layer.
3 can be formed by vapor deposition by sputtering,
The information recording layer can be made highly insulating and can be a noise-free information recording layer when recording information.

The electrode layers 13 and 13 'can employ the same material and forming method as those of the electrode layer in the above-mentioned first information recording medium, but are transparent when the recorded information is read by transmitted light. 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 the second information recording medium, an intermediate layer 12 may be provided between the photoconductive layer 14 and the information recording layer 11 as shown in FIG. 8B. When the photoconductive layer is an organic photosensitive layer formed by using a solvent, the intermediate layer 12 causes the liquid crystal in the information recording layer to elute due to the interaction depending on the solvent, or the information recording layer is photoconductive. The photoconductive material is eluted by the solvent for forming the information recording layer at the time of coating and forming on the layer, which causes image unevenness, and is provided to prevent this.

As such an intermediate layer, inorganic materials such as SiO ₂ , TiO ₂ , CeO ₂ , Al ₂ O ₃ , GeO ₂ , Si ₃ N ₄ , AlN,
TiN, MgF ₂ , ZnS or the like may be used and laminated by vapor deposition, sputtering, chemical vapor deposition (CVD) or the like.

Further, an aqueous solution of polyvinyl alcohol, water-based polyurethane, water glass or the like is used as a water-soluble resin having a low compatibility with an organic solvent, and laminated by spin coating, blade coating, roll coating or the like. Good. 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.

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.

Of the various materials mentioned above, it is particularly preferable to use polyvinyl alcohol, and when a material having a saponification degree of 97% or more and a polymerization degree of 1500 or more is used, the formation of the information recording layer is excellent. Can be something.

In forming the intermediate layer, it is necessary that the intermediate layer is incompatible with either the organic photoconductive layer forming material or the information recording layer forming material. Insulation of 10 ⁷ Ωcm or more is required because diffusion occurs and resolution deteriorates. Also,
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 μm 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 coated, the type of solvent, and the viscosity, the film thickness of the material to be laminated and coated may be appropriately set. The intermediate layer is required to be transparent, and in consideration of the voltage distribution applied to each layer, a material having a high dielectric constant as well as a thin film is preferable. 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, the 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 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 can obtain recording at the liquid crystal particle level, so that high resolution can be obtained, 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. When the information recorded on the second information 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 information recording medium shown in FIG. The same applies when reading with reflected light.

Next, as shown in FIG. 8C, the second information recording medium of the present invention has an insulating light reflection layer 12 between the photoconductive layer and the information recording layer in the second information recording medium. ′ And a transparent insulating layer 12 ″ may be provided.
The recording information can be read by making the reading light from the information recording layer side incident and reflecting it.

Examples of the insulating light reflection layer 12 'include a dielectric mirror layer and a light-shielding light-shielding film. 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 50Å /
Second, germanium is vapor-deposited at a rate of 20 Å / sec at the same time to give a film thickness of about 1 μm.

The transparent insulating layer 12 ″ is the insulating light reflecting layer 1
When the information recording layer 11 is directly formed on the 2 ', there is a problem that the insulating light reflection layer 12' is peeled off, and it is provided to prevent the peeling and improve the formation of the information recording layer 11. The transparent insulating layer 12 ″ is the same as the intermediate layer 12 described above.

The insulating light-reflecting layer 12 'and the transparent insulating layer 12 "reduce the distribution voltage applied to the liquid crystal layer or worsen the resolution like the above-mentioned intermediate layer, so that the film thickness should be smaller. Is preferable, and the total is 2 μm or less, preferably 0.1 μm to 1 μm.

In this information recording medium, the read light does not pass through the generally colored photoconductive layer when reading the information, so that the reproduced information can be noise-free.

In the first and second information recording media of the present invention, a primer layer is provided between the electrode layer, the light reflection layer or the light reflection prevention layer, the substrate and the like to improve 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. Is the range. Since the voltage applied to the information recording layer can be controlled by improving the adhesiveness and changing the film thickness, the recordable exposure range can be controlled.

Further, the first and second information recording media of the present invention are used by being cut in the layer width direction into an appropriate size according to the use mode, 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 and second 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.

[0087]

In the first and second information recording media of the present invention, the information recording layer has a thickness of 50 in 0.1 seconds in the film thickness direction.
By setting a current value of 7.0 × 10 ⁻⁶ A / cm ² or less as the current value immediately before the transition to the maximum peak portion in the voltage-current characteristics shown when a slope voltage of 0 V is applied, the solution is obtained. It can be regarded as an information recording medium having excellent image quality. Examples will be described below.
“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, -dipentaerythritol hexaacrylate--9 parts-photocuring initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by Ciba-Geigy: trade name Darocur 1173)-・ 0.45 parts ・ Smectic liquid crystal (Merck, S-6) ・ ・ 10 parts ・ Nematic liquid crystal (Merck, BL-066) ・ ・ 1 part ・ Surfactant (Sumitomo 3M: trade name Florard FC-430) ... 0.2 part of xylene (manufactured by Junsei Kagaku Co., Ltd., reagent grade) is uniformly dissolved in a solution, which is 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 500 mJ / cm ²
Was irradiated with UV light to form an information recording layer having a film thickness of 6 μm.

After the liquid crystal was extracted from the cut surface of the obtained information recording layer with hot methanol and dried, a scanning electron microscope (manufactured by Hitachi Ltd., S-800, 10000) was used.
When observing the internal structure, the surface of the layer is 0.6μ.
It was found that the structure was covered with an m-thick (10% of film thickness) ultraviolet curable resin, and the inside of the layer was filled with resin particles having a particle diameter of 0.1 μm.

A gold electrode was formed on the information recording layer of this information recording medium by vapor deposition, and a slope voltage of 500 V in 0.1 second was applied by the measuring apparatus shown in FIG. 4 to record the information. The result of measuring the voltage-current characteristics in the layer is shown by the line (a) in FIG. 10. That is, the current value was 6 × 10 ⁻⁶ A / cm ² at 50 V, and the driving voltage was as high as 230 V.

Next, the information recording medium and the resolution pattern of the chrome substrate are arranged so as to face each other with a PET film of 10 μm as a spacer, and the information recording medium side is set to the negative side.
A DC voltage of 0 V was applied and the resolution pattern was recorded.
After recording, the information recording medium was taken out and observed with a polarization microscope. As a result, a line & space of 6 μm was resolved.

[0092]

Comparative Example 1 The composition for forming an information recording layer in Example 1 was prepared by: dipentaerythritol hexaacrylate 9 parts Photocuring initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one) , Ciba-Geigy: trade name Darocur 1173) ・ 0.45 part ・ Smectic liquid crystal (Merck S-6) ・ ・ 12 parts ・ Nematic liquid crystal (Merck BL-066) ・ ・ 2 parts -Surfactant (Sumitomo 3M: trade name Florard FC-430) --- An information recording layer was formed in the same manner as in Example 1 except that 0.2 parts was used, and in the same manner as in Example 1. The result of measuring the voltage-current characteristics is shown by the line (b) in FIG.

That is, at 50V, 7.5 × 10 ⁻⁶ A /
The current value was cm ² , and the driving voltage was as low as 180V.

Further, as in the case of Example 1, when the information recording medium was made to face the resolution pattern of the chromium substrate and recording was performed in the same manner, only the line & space of 10 μm was resolved.

[0095]

Comparative Example 2 The composition for forming an information recording layer in Example 1 was prepared by: dipentaerythritol hexaacrylate 9 parts Photocuring initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one) , Ciba-Geigy: Trade name Darocur 1173) ・ ・ 0.45 part ・ Smectic liquid crystal (Merck, S-1) ・ ・ 11 parts ・ Surfactant (Sumitomo 3M: trade name Florard FC-430 .. The information recording layer was formed in the same manner as in Example 1 except that the content was changed to 0.2 part, and the voltage-current characteristics were measured in the same manner as in Example 1 and the result is shown in FIG. Shown with a line.

That is, at 50 V, 1.0 × 10 ⁻⁵ A /
The current value was cm ² , and the driving voltage was as low as 140V.

Further, when the information recording medium was made to face the resolution pattern of the chrome substrate and recording was carried out in the same manner as in Example 1, only the line and space of 20 μm was resolved.

[0098]

Example 2 (Production of optical sensor) ・ The following structure as a charge generator

[0099]

[Chemical 1]

Using a mixed solvent of 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 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.

[0102]

[Chemical 2]

25 parts of para-dimethylstilbene, 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 optical sensor thus obtained and the information recording medium prepared in Example 1 were placed so as to face each other with a PET film of 10 μm as a spacer and incorporated in the recording apparatus of FIG. A DC voltage of 700 V was applied with the information recording medium side being negative. With voltage applied,
Exposure from a light sensor side using a halogen lamp with an illuminance of 1000 lux as a light source was performed for 0.1 seconds, and a gray scale was photographed.

After the completion of exposure, the information recording medium was taken out and the transmittance of the exposed and unexposed areas was measured using an ultraviolet and visible spectrophotometer to find that it was 90% and 40%, and a high contrast ratio was obtained. Was given.

The Nikon type film scanner (LS
-3510AF), a xenon lamp was used as a light source, information was read by the wavelength light through a wavelength filter (357 nm), and the information was output by a sublimation printer. The output image was good.

[0107]

Example 3 Fluorine-containing resin CYTOP (trade name; Asahi Glass) on the photoconductive layer in the optical sensor prepared in Example 2.
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,
An intermediate layer (transparent insulating layer) having a film thickness of 1 μm was formed.

Next, on this transparent insulating layer: Dipentaerythritol hexaacrylate 9 parts Photocuring initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one, Ciba Geigy) Manufactured: Product name Darocur 1173) ・ ・ 0.45 part ・ Smectic liquid crystal (Merck, S-6) ・ ・ 10 part ・ Nematic liquid crystal (Merck, BL-066) ・ ・ 1 part ・ Surfactant ( Sumitomo 3M: trade name Florard FC-430) ... 0.2 parts of xylene (manufactured by Junsei Kagaku Co., Ltd., reagent grade) 22 parts was uniformly dissolved and 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 500 mJ / cm ²
Was irradiated with UV light to form an information recording layer having a film thickness of 6 μm.

Further, an Au film having a film thickness of 500 Å was formed as an upper electrode on this information recording layer by a vapor deposition method to prepare a second information recording medium of the present invention.

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 photoconductive layer side under voltage application, and a gray scale was photographed.

After completion of the exposure, a Nikon type film scanner (LS-3510AF) was used, a xenon lamp was used as a light source, and information was read by transmitted light with the wavelength light through a wavelength filter (500 nm). When it was output, the output image was good.

[Brief description of drawings]

FIG. 1 is a schematic view showing a cross section of a first information recording medium of the present invention.

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 a method for measuring voltage-current characteristics in an information recording layer.

FIG. 5 is a diagram for explaining a voltage application method used for measuring a voltage-current characteristic in an information recording layer.

FIG. 6 is a diagram for explaining a voltage-current characteristic in an information recording layer.

FIG. 7 is a schematic diagram for explaining a circuit of the information recording layer.

8 (a), (b) and (c) are schematic views showing a cross section of a second information recording medium of the present invention.

FIG. 9 is a diagram for explaining an information recording method on a second information recording medium.

FIG. 10 is a diagram for explaining voltage-current characteristics in the information recording layer.

[Explanation of symbols]

1 is an optical sensor, 3 is an information recording medium, 11 is an information recording layer, 12 is an intermediate layer, 12 'is an insulating light reflecting layer, 12 "is a transparent insulating layer, 13 and 13' are electrode layers, and 14 is photoconductive. layer,
Reference numeral 15 is a substrate, 18 is information light, 19 is a spacer, 21 is a light source, 22 is a shutter having a driving mechanism, 23 is a pulse generator (power supply), 24 is a dark box, A is transmitted light,
B is scattered light. 30 is a gold electrode, 100 is an ammeter, 1
01 is a power supply.

Claims (2)

(57) [Claims] 1. An information recording medium having an information recording layer comprising a smectic liquid crystal phase and a resin phase on an electrode layer, wherein the information recording layer is a liquid crystal in which a nematic liquid crystal is mixed with a smectic liquid crystal having a driving voltage of at least 100 V or more. Content of 10 to 53% by weight and a thickness of 1 to 30 μm, and the thickness of the information recording layer is 0.0
A skin layer having a film thickness of 1 to 50% is formed, and the inside thereof is filled with resin particles having a primary particle diameter of 0.03 to 0.3 μm, and has a structure in which a liquid crystal phase communicates between them. In the voltage-current characteristics shown when a slope voltage of 500 V was applied for 0.1 second in the film thickness direction, the current value for an applied voltage equal to or lower than the drive voltage was 7.0 × 10 ⁻⁶ A / c.
An information recording medium having a value of m ² or less. 2. 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 of the electrode layer is transparent, and the information recording layer comprises:
It contains 10 to 53% by weight of a liquid crystal in which a nematic liquid crystal is mixed with a smectic liquid crystal having a driving voltage of at least 100 V or more, and has a film thickness of 1 to 30 μm. A skin layer having a film thickness of 01 to 50% is formed, the inside is filled with resin particles having a primary particle diameter of 0.03 to 0.3 μm, and a liquid crystal phase is in communication between them. 0.1 seconds in the film thickness direction
In the voltage-current characteristics shown when a slope voltage of 500 V is applied between the ^two, it is confirmed that the current value with respect to the applied voltage of the drive voltage or less shows a value of 7.0 × 10 ⁻⁶ A / cm ² or less. Characteristic information recording medium.