JP3204745B2 - Information recording medium and information recording / reproducing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recording and storing electrostatic information as visible information using a resin body in which liquid crystals are dispersed and fixed,
The present invention relates to an information recording medium that can be reproduced at an arbitrary time, a method of manufacturing the same, and an information recording and reproducing method thereof, and particularly relates to an information recording medium having no variation in light transmittance, a method of manufacturing the same, and an information recording and reproducing method thereof.

[0002]

2. Description of the Related Art Liquid crystal display devices are used for displays for office automation equipment such as word processors and laptop computers. In these, a liquid crystal layer is sandwiched between transparent substrates such as glass or plastic substrates provided with two transparent electrode films, and an image is formed by applying a voltage between both electrodes using a single matrix or an active matrix. And the like.

As this method, a typical TN type, STN
In addition to the type, there are a dynamic scattering type operated by a current effect, a type utilizing a cholesteric-nematic phase transition, and more recently, a type combining a polymer and a liquid crystal. In a device in which a nematic liquid crystal is dispersed and fixed in a polymer resin body, the orientation of the liquid crystal material is oriented in the direction of voltage application by applying a voltage by keeping the ordinary light refractive index of the liquid crystal material and the refractive index of the polymer resin body equal. When they are aligned, they become transparent, and when no voltage is applied, the orientation of the liquid crystal material becomes irregular, and as a result, light is scattered at the interface between the liquid crystal and the polymer resin body or in the liquid crystal fixed by dispersion, resulting in an opaque state. This is to utilize the state, and to display information in a transparent and opaque manner.

A liquid crystal display device in which a nematic liquid crystal is dispersed and fixed in a polymer resin body can have a large area, has a short response time, particularly a short rise time, does not require a polarizing plate, has a high light use efficiency, and has a wide viewing angle. It has features such as being wide and uniform or having flexibility, and has recently been reported for use in window light control sheets or projection displays.
As an application to a projection type display or a computer display, there is an advantage that the fall time is as short as 1 to 30 ms and the fall time is shorter than that of a TN type or STN type display which is most frequently used.

In a normal case, a liquid crystal display element in which a nematic liquid crystal is dispersed and fixed in a polymer resin body is one in which an alternating voltage is applied in a state sandwiched between electrodes, and display and erasing can be performed by turning on and off the voltage. It is. At this time, there is a report that a slight hysteresis occurs in the voltage vs. light transmittance, and a difference occurs in the transmittance between when the applied AC voltage is increased and when the applied AC voltage is decreased. It returns to the initial transmittance, that is, the opaque state.

As a method of displaying information such as an image, a method of displaying the image by turning it on and off for each pixel while sandwiching it between matrix electrodes is generally used. When forming a composite film of molecules and liquid crystal, for example, there is a method of irradiating image-like ultraviolet rays using an ultraviolet-curable polymer material, and all of these methods flash fixed information.

On the other hand, those having memory properties include:
There is a method using cholesteric-nematic phase transfer, but in this method, it is necessary to have a sandwich structure in which a vertical alignment film is sandwiched between transparent electrodes formed on the electrode. In this case, an electrode structure is required.

Recently, a liquid crystal cell using a polymer dispersed liquid crystal instead of a liquid crystal layer has been developed. In such an information recording medium, a polymer-dispersed liquid crystal is held while being sandwiched between two substrates having ITO electrodes.

[0009] Further, the information recording medium is formed on a substrate / ITO electrode /
By forming a polymer dispersed liquid crystal layer and exposing it when applying a voltage while facing the photoreceptor consisting of the electrode and the photoconductive layer, a discharge phenomenon corresponding to the information light is generated, and the electrostatic information is enhanced. A device that records data in the form of alignment of a molecule-dispersed liquid crystal layer has also been developed (JP-A-2-18633).

In this case, the liquid crystal dispersed in the resin body is
Especially in the case of smectic liquid crystal, the memory property is large,
Even if the electric field is removed, the modulated orientation is maintained as it is, and the image can be read even if left for a long time. Since this visible image is erased by heating to a temperature near the isotropic phase transition of the liquid crystal, it can be reused.

In the information recording medium in which the liquid crystal is dispersed in the resin as described above, the recording medium in which the smectic liquid crystal or the nematic liquid crystal is individually dispersed is opposed to the photosensitive member, and the information is recorded on the information recording layer by voltage application exposure. In this case, it has been found that unevenness in recording occurs due to variations in light transmittance in the medium before recording, and high-resolution images cannot be recorded.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an information recording medium having a small variation in light transmittance, a method for manufacturing the same, and an information recording / reproducing method using the information recording medium. I do.

[0013]

The information recording medium of the present invention is an information recording medium in which an information recording layer is laminated on a transparent electrode, wherein the information recording layer has a mixed weight of a nematic liquid crystal and a smectic liquid crystal. The information recording layer has a structure in which a skin layer made of an ultraviolet-curable resin is formed, while having a structure in which a phase composed of a mixed liquid crystal having a ratio of 5/95 to 20/80 and a UV-curable resin phase are phase-separated. It is characterized by having.

In the method of manufacturing an information recording medium according to the present invention, a mixed solution comprising a smectic liquid crystal and an ultraviolet-curable resin is applied on a transparent electrode, and then a smooth substrate having ultraviolet transmittance is placed on the coated surface. While pressing the coating layer uniformly, the ultraviolet curing resin is cured by ultraviolet irradiation,
Forming an information recording layer having a structure in which a phase composed of a smectic liquid crystal and a UV-curable resin phase are phase-separated, and a skin layer composed of an ultraviolet-curable resin formed on an outer surface,
Then, the substrate is separated.

Further, in the method of manufacturing an information recording medium according to the present invention, a mixed solution of a nematic liquid crystal and a smectic liquid crystal in a mixed weight ratio of 5/95 to 20/80 and an ultraviolet curable resin is coated on a transparent electrode. After applying, a smooth substrate having ultraviolet permeability is placed on the application surface, and while uniformly applying pressure to the application layer, the ultraviolet curable resin is cured by irradiation with ultraviolet light, and the mixed weight of nematic liquid crystal and smectic liquid crystal is applied. Information recording having a structure in which a phase composed of a mixed liquid crystal having a ratio of 5/95 to 20/80 and a UV-curable resin phase are separated, and a skin layer composed of a UV-curable resin is formed on the outer surface. Forming a layer, and then peeling off the smooth substrate.

According to the method for recording and reproducing information on an information recording medium of the present invention, a phase composed of a mixed liquid crystal having a mixing weight ratio of a nematic liquid crystal and a smectic liquid crystal of 5/95 to 20/80 on a transparent electrode and an ultraviolet curable resin An information recording medium having a structure separated from a phase and an information recording layer in which a skin layer made of an ultraviolet curable resin is formed on the outer surface of the information recording layer, and a photoconductive layer on a transparent electrode. The laminated photoreceptor is disposed to face, image exposure is performed with a voltage applied between the information recording medium electrode and the photoreceptor electrode, and the liquid crystal phase in the information recording layer is aligned according to the exposure pattern, and then The exposure pattern is reproduced as visible information by transmitted or reflected light.

Hereinafter, an information recording medium and an information recording / reproducing method of the present invention will be described. FIG. 1 is a diagram for schematically explaining a cross section of the 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.

The electrode layer 13 may be any one or both of which are transparent, and include a metal thin film conductive film having a specific resistance of 10 ⁶ Ω · cm or less, an inorganic metal oxide conductive film, a quaternary ammonium salt, and the like. Organic conductive film. The electrode layer 13 is formed by a method such as vapor deposition, sputtering, CVD, coating, plating, dipping, and electrolytic polymerization. Further, the film thickness needs to be changed depending on the electrical characteristics of the material constituting the electrode and the applied voltage at the time of information recording. For example, the thickness of the ITO film is about 100 to 3000 °, and the entire surface between the information recording layer and Alternatively, it is formed according to the formation pattern of the information recording layer.

The substrate 15 may be transparent or opaque, but strongly supports an information recording medium having a shape such as a card, a film, a tape, or a disk. If it has, there is no need to provide it, but the material and thickness are not particularly limited as long as it has a certain strength capable of supporting the information recording layer. For example, a flexible plastic film or a rigid body such as glass, a plastic sheet, or a card is used. Specifically, when the information recording medium takes the shape of a flexible film, tape, disk, or card,
When a flexible plastic film is used and strength is required, a rigid sheet or an inorganic material such as glass is used.

When reproducing information with transmitted light, the substrate 15 needs to have transparency.
On the other surface of the substrate on which the electrode layer 13 is provided, a layer having an anti-reflection effect is laminated as necessary, or the transparent substrate is adjusted to a film thickness capable of exhibiting the anti-reflection effect, or both are further adjusted. Antireflection properties may be imparted by combining them.

Next, the information recording layer 11 has a structure in which a mixed liquid crystal phase of a smectic liquid crystal and a nematic liquid crystal is separated from a resin phase. First, smectic liquid crystals exhibit a smectic phase at room temperature (25 ° C.).
A liquid crystal material exhibiting a smectic A phase such as a cyanobiphenyl-based, cyanoterphenyl-based, phenylester-based, and fluorine-based liquid crystal material having a long carbon chain at a terminal group of a material exhibiting a liquid crystal property, and a smectic C phase used as a ferroelectric liquid crystal. And a liquid crystal substance exhibiting smectic H, G, E, F, and the like. Smectic liquid crystals are excellent in so-called memory properties, in which the orientation of the liquid crystal is maintained after information recording and information is permanently maintained.

The nematic liquid crystal mixed with the smectic liquid crystal exhibits a nematic liquid crystal phase at normal temperature (25 ° C.), and includes, for example, Schiff base type, azoxy type,
Azo, phenyl benzoate, phenyl cyclohexyl, biphenyl, terphenyl, phenylcyclohexane, phenylpyridine,
Known nematic liquid crystals such as phenyl oxazine type, polycyclic ethane type, phenyl cyclohexene type, cyclohexyl pyrimidine type, phenyl type and tolan type can be used.
When a liquid crystal material is selected, a material having a different direction of the refractive index is preferable because contrast can be obtained.

The mixing weight ratio of the nematic liquid crystal and the smectic liquid crystal is preferably 5/95 to 20/80. If the nematic liquid crystal is less than 5% by weight, the light transmittance greatly varies and exceeds 20% by weight. In addition, the memory property is deteriorated, and the dispersion of the light transmittance is increased, which is not preferable. By using a mixed phase of nematic liquid crystal and smectic liquid crystal, the detailed reason is unknown compared to the case of using each alone, but the liquid crystal distribution inside the information recording layer can be made uniform and the light transmission It seems that the variation of the rate can be reduced.

Examples of the material forming the resin phase include UV-curable resins that are compatible with the liquid crystal material in the form of monomers and oligomers, or that are compatible with common solvents.

When an ultraviolet curable resin is used, a skin layer is formed on the surface of the information recording layer, and even when a large amount of liquid crystal is contained, phenomena such as bleeding of liquid crystal are suppressed, and bleeding of liquid crystal onto the surface of the information recording layer is prevented. , And a decrease in conductivity of the electrode layer can be prevented.

Examples of such UV-curable resins include acrylic acid esters and methacrylic acid esters. In the form 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, and other polyfunctional monomers or urethanes , Ester-based oligomers, nonylphenol-modified acrylates, N-vinyl-2-pyrrolidone,
Monofunctional monomers or oligomers such as 2-hydroxy-3-phenoxypropyl acrylate are exemplified.

The solvent is not particularly limited as long as it is a common solvent. Examples thereof include hydrocarbon solvents such as xylene, halogenated hydrocarbon solvents such as chloroform, and methyl cellosolve. And ether solvents such as dioxane.

Examples of the photocuring agent include 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck) and 1-hydroxycyclohexylphenylketone (“Irgacure” manufactured by Ciba Geigy). 184 "), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one (" Darocure 1116 "manufactured by Merck), benzyldimethylketal (" Irgacure 65 "manufactured by Ciba-Geigy)
1 "), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (" Irgacure 907 ", manufactured by Ciba-Geigy), 2,4-diethylthioxanthone (manufactured by Nippon Kayaku Co., Ltd.) A mixture of “Kayacure DETX”) and ethyl p-dimethylaminobenzoate (“Kayacure EPA” manufactured by Nippon Kayaku Co., Ltd.), isopropylthioxanthone (“Kuntacure I” manufactured by Ward Brekinsop)
A mixture of "TX" and ethyl p-dimethylaminobenzoate, and the like. Liquid 2-hydroxy-2-methyl-1-phenylpropan-1-one is a liquid crystal, and a polymer-forming monomer or oligomer. It is particularly preferable in terms of compatibility with the resin forming material.

The ratio between the liquid crystal and the resin-forming material is preferably such that the content of the liquid crystal is 10 to 90% by weight, preferably 40 to 80% by weight, and less than 10% by weight. Even if the liquid crystal phase is oriented by information recording, the contrast ratio is low, and if it exceeds 90% by weight, phenomena such as bleeding of the liquid crystal occur and image unevenness occurs, which is not preferable. In general, when a large amount of liquid crystal is present in the information recording phase, the contrast ratio can be improved and the operating voltage can be reduced.

When an information recording layer is formed by using an ultraviolet curable resin as a resin forming material, the surface of the information recording layer is covered with the ultraviolet curable resin, and the inside of the layer contains a liquid crystal phase and a resin particle phase. Having a structure filled with.

Next, a method for manufacturing the information recording medium of the present invention will be described. The information recording layer is formed by applying a resin-forming material and a mixed liquid crystal as a mixed solution having a solid content of 10 to 60% by weight on the electrode layer using a blade coater, a roll coater, a spin coater, or the like, and curing the mixture. It is formed by this.

If necessary, a leveling agent may be added to improve the applicability of the solution and improve the surface properties, and a fluorine-based material may be used to maintain the wettability to the electrode layer. A surfactant is added.

Examples of such a fluorine-based surfactant include Florad FC-430, Florad FC-431, and N- (n-propyl) -N- manufactured by Sumitomo 3M Limited.
(Β-acryloxyethyl) -perfluorooctylsulfonic acid amide [EF-125 manufactured by Mitsubishi Materials Corporation]
M], N- (n-propyl) -N- (β-methacryloxyethyl) -perfluorooctylsulfonic acid amide [EF-135M manufactured by Mitsubishi Materials Corporation], perfluorooctanesulfonic acid [Mitsubishi Materials Corporation EF
-101], perfluorocaprylic acid [EF-201 manufactured by Mitsubishi Materials Corporation], N- (n-propyl) -N-
Perfluorooctane sulfonic acid amide ethanol [EF-121 manufactured by Mitsubishi Materials Corporation], and EF-102, EF-103, and EF- manufactured by Mitsubishi Materials Corporation
104, EF-105, EF-112, EF-1
21, EF-122A, EF-122B, EF-
122C, EF-122A3, EF-123A, EF-123B, EF-132, EF-301, EF-303, EF-305, EF-306A, EF-501, and EF- 700, EF-201, E
F-204, EF-351, EF-352, EF
-801, EF-802, EF-125DS, E
F-1200, EF-L102, EF-L155,
EF-L174 and EF-L215.
Also, 3- (2-perfluorohexyl) ethoxy-
1,2-dihydroxypropane [Mitsubishi Materials Corporation
MF-100], N-n-propyl-N-2,3-dihydroxypropylperfluorooctylsulfonamide [MF-110 from Mitsubishi Materials Corporation], 3- (2
-Perfluorohexyl) ethoxy-1,2-epoxypropane [MF-120 manufactured by Mitsubishi Materials Corporation], N
-N-propyl-N-2,3-epoxypropylperfluorooctylsulfonamide [Mitsubishi Materials Corporation
MF-130], perfluorohexyl ethylene [MF-140 from Mitsubishi Materials Corporation], N- [3-trimethoxysilyl) propyl] perfluoroheptylcarboxylic acid amide [MF-15 from Mitsubishi Materials Corporation]
0], N- [3-trimethoxysilyl) propyl] perfluoroheptylsulfonamide [MF-160 manufactured by Mitsubishi Materials Corporation] and the like. The fluorine-based surfactant is used in an amount of 0.1 to the total amount of the liquid crystal and the resin-forming material.
It is used at a rate of ２０20% by weight.

In the present invention, in particular, a mixed solution of the resin-forming material and the mixed liquid crystal is applied on the electrode, dried, and then a smooth substrate is placed on the applied surface to uniformly apply the applied layer. It has been found that when the information recording layer is formed by curing the curable resin while applying pressure and then peeling the substrate, the information recording layer can have a smaller variation in light transmittance. Although the detailed reason is unknown, the structure of the resin phase inside the information recording layer is uniform by placing the smooth substrate on the coating surface and pressing the coating layer evenly and curing the curable resin. It is thought that the variation in light transmittance is reduced.

When a thermosetting resin is used as the resin material for the smooth substrate, the material is not particularly limited, but an active energy ray-curable resin such as an ultraviolet curable resin or an electron beam curable resin is used. In this case, it is preferable to use an active energy ray transmitting substrate, such as quartz glass.

According to the method for producing an information recording medium of the present invention, by using a mixed liquid crystal as a liquid crystal, an information recording medium with less variation in light transmittance can be obtained. However, a smectic liquid crystal is used alone as a liquid crystal. Even in the case of performing, by placing a smooth substrate on the application surface and uniformly applying pressure to the application layer, by curing the curable resin,
The structure of the resin phase inside the information recording layer is made uniform, and the variation in light transmittance can be reduced.

In applying the mixed solution of the resin-forming material and the liquid crystal, it is necessary to heat the liquid crystal to a temperature higher than a temperature at which the liquid crystal maintains an isotropic phase to completely dissolve the liquid crystal and the resin-forming material. is necessary. When the information recording layer is cured at a temperature equal to or lower than the temperature at which the liquid crystal exhibits an isotropic phase, a problem occurs due to partial phase separation between the liquid crystal and the resin material. That is, the liquid crystal domain grows too much, the skin layer is not completely formed on the surface of the information recording layer, and the liquid crystal seeps out, or the resin is matted, making it difficult to accurately take in information. In some cases, the resin cannot hold the liquid crystal and the information recording layer is not even formed. Also, when evaporating the solvent, if heating is necessary to maintain the isotropic phase, in particular, the wettability to the electrode layer is reduced,
There is a problem that a uniform information recording layer cannot be obtained.

When an ultraviolet curable resin material is used as the resin, the outer surface layer of the information recording layer can be a skin layer composed of only the resin phase. When the skin layer is formed on the outer surface of the information recording layer, the use ratio of the liquid crystal in the information recording layer can be increased, and the bleeding of the liquid crystal can be eliminated.

Since the thickness of the information recording layer affects the resolution, the thickness after drying is 0.1 μm to 20 μm, preferably 3 μm.
The thickness is preferably from 8 μm to 8 μm, whereby the operating voltage can be reduced while maintaining high resolution. If the film thickness is too thin, the contrast of the information recording section is low, and if it is too thick, the operating voltage is undesirably high.

Next, the information recording / reproducing method of the present invention will be described. The photoconductor used for recording information on the information recording medium can be a single-layer photoconductor or a stacked photoconductor. A single-layer photoreceptor is formed by laminating a mixture of a charge generating substance and a charge transporting substance on an electrode, and a laminated photoreceptor separates a charge generating layer and a charge transporting layer,
This is a type in which a charge generation layer and a charge transport layer are sequentially laminated on an electrode.

In the photoreceptor used in the present invention, the following general formula (1):

[0042]

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(Where X in the formula may be the same or different selected from hydrogen, lower alkyl group, lower alkoxy group, nitro group, sulfonic group, hydroxyl group, carboxyl group, halogen atom, and n is An integer of 0 to 3, and R is a hydrocarbon ring group, a heterocyclic group, or an alkyl group which may be substituted.) As a charge generating substance, and an electron accepting substance. In the case of a single-layer type photoreceptor, it is added together with a bisazo compound, and in the case of a multilayer type photoreceptor, it is added together with a bisazo type compound to the charge generation layer or added together with the charge generation layer and added to the charge transport layer Is also added.

The photoreceptor used in the present invention can not only provide electrostatic information corresponding to an information pattern with high sensitivity and high contrast to a charge holding medium, but also provide a photoreceptor after the photoreceptor is prepared. Even during the course, the contrast ratio is excellent in stability over time since the dark potential does not increase.

First, bisazo compounds which can be preferably used in the present invention are exemplified below by combinations of the respective substituents in the above formula (1).

[0046]

[Table 1]

Among them, preferred bisazo compounds are exemplified below.

[0048]

Embedded image

Next, the charge transporting substance forming the charge transporting layer is a substance having a good transporting property of the charge generated by the charge generating substance, for example, hydrazone type, pyrazoline type and PVK type.
System, carbazole system, oxazole system, triazole system, aromatic amine system, amine system, triphenylmethane system, polycyclic aromatic compound system, etc. it can.

In particular, the compound number (2
Those of 4) to (33) are preferred.

[0051]

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[0052]

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Next, as the electron accepting substance to be added to the charge generation layer or the charge generation layer and the charge transport layer,
4,7-trinitrofluorenone, tetrafluoro-P
-Benzoquinone, tetracyanoquinodimethane, triphenylmethane, maleic anhydride, hexacyanobutadiene and the like can be used.

Next, a method for manufacturing a photoreceptor will be described. First, as a laminated photoreceptor, first, a charge generating substance and an electron accepting substance are mixed at a ratio of 0.001 part by weight to 10 parts by weight of an electron accepting substance with respect to 1 part by weight of the charge generating substance. Dispersed and dissolved in an appropriate medium, coated on the electrode and dried to form a charge generating layer, and then, on this charge generating layer, a charge transporting substance is dissolved or dispersed in a suitable medium and applied to charge transport. A layer is formed, or an electron accepting substance is mixed in a ratio of 0.001 to 10 parts by weight with respect to 1 part by weight of a charge transporting substance, dispersed and dissolved in an appropriate medium, and coated and dried. To form a charge transport layer. The charge generation layer preferably has a thickness of 0.1 to 10 μm after drying, and the charge transport layer has a thickness of 1 to 50 μm.

In a single-layer type photoreceptor, the charge generating substance and the charge transporting substance are preferably mixed at a ratio (parts by weight) of 1: 100 to 100: 100, and the electron accepting substance is mixed with the charge generating substance and the charge transporting substance. 0.1 parts per 1 part by weight of the total amount of the substance.
It is advisable to mix them in a ratio of 001 parts by weight to 10 parts by weight, and they are dispersed or dissolved in a medium, coated on an electrode, and dried to form a layer. The thickness is preferably 1 to 50 μm.

A charge transfer complex may be formed by forming a complex with the charge generating substance and the charge transporting substance. Normal,
The photoreceptor has photosensitivity determined by the light absorption characteristics of the charge generating material. However, when a charge generating material and a charge transporting material are mixed to form a complex, the light absorption characteristics change. For example, polyvinyl carbazole (PVK) is used in the ultraviolet region. Although only trinitrofluorenone (TNF) feels only around 400 nm wavelength, the PVK-TNF complex becomes sensitive up to 650 nm wavelength range.

In both the single-layer type and the laminated type, a binder can be used to form the photoconductive layer. Examples of the binder include a silicone resin, a styrene-butadiene copolymer resin, an epoxy resin, and an acrylic resin. , A saturated or unsaturated polyester resin, a polycarbonate resin, a polyvinyl acetal resin, a phenol resin, a polymethyl methacrylate (PMMA) resin, a melamine resin, a polyimide resin, a vinyl chloride resin, a vinyl acetate resin, and the like. It is preferable to use 0.1 to 10 parts by weight for 1 part by weight of each material of the transport substance. In the case where the charge generating substance and the charge transporting substance show the role of the binder itself, the binder is unnecessary.

As the solvent, dichloroethane, 1,1,
2-trichloroethane, monochlorobenzene, tetrahydrofuran, cyclohexane, dioxane, 1,2,3
-Trichloropropane, ethyl cellosolve, 1,1,
Examples thereof include 1, -trichloroethane, methyl ethyl ketone, chloroform, and toluene.

As a coating method, a coating method such as a blade coating method, a dipping method and a spinner coating method can be used.

In the photoreceptor of the present invention, it is not always necessary to provide the photoconductive layer to lower the sensitivity. However, as a means for increasing the current difference between the exposed and unexposed portions, the photoconductive layer is provided with an electrode via a charge injection preventing layer. It may be laminated on top.

The charge injection prevention layer is a dark current (for example, charge injection from an electrode) when a voltage is applied to the photoconductive layer, that is, the charge moves in the photoconductive layer as if it were exposed even though it was not exposed. This is provided in order to prevent the phenomenon that occurs.

There are two types of charge injection preventing layers, one utilizing a so-called tunneling effect and one utilizing a rectifying effect. First, in a device utilizing the so-called tunneling effect, current does not flow to the photoconductive layer or the insulating layer surface due to the charge injection preventing layer only by applying a voltage, but when light is incident, it corresponds to an incident portion. In the charge injection preventing layer, a high electric field is applied due to the presence of one of the charges (electrons or holes) generated in the photoconductive layer, causing a tunnel effect and causing a current to flow through the charge injection preventing layer. .

Such a charge injection preventing layer has an inorganic insulating property.
Film, organic insulating polymer film, insulating monolayer, etc.
Or, they are formed by laminating them, and as an inorganic insulating film
Is, for example, As_TwoO_Three, B_TwoO_Three, Bi_TwoO_Three, CdS, CaO, CeO_Two,
Cr_TwoO_Three, CoO, GeO_Two, HfO_Two, Fe_TwoO_Three , La_TwoO_Three, MgO, Mn
O_Two, Nd_TwoO_Three, Nb_TwoO_Five, PbO, Sb_TwoO_Three, SiO_Two, SeO_Two, Ta_TwoO
_Five, TiO_Two, WO_Three, V_TwoO_Five, Y_TwoO_Five, Y_TwoO_Three, ZrO_Two, BaTiO_Three, Al
_TwoO_Three, Bi_TwoTiO_Five, CaO-SrO, CaO-Y_TwoO_Three, Cr-SiO, LiTa
O_Three, PbTiO_Three, PbZrO_Three, ZrO_Two-Co, ZrO_Two-SiO_Two, AlN, B
N, NbN, Si_ThreeN_Four, TaN, TiN, VN, ZrN, SiC, TiC
 , WC, Al_FourC_ThreeGlow discharge, evaporation, sputtering etc.
And the like. The thickness of this layer prevents charge injection
It is used in consideration of insulation properties and tunnel effect.
Determined for each material.

Next, the charge injection preventing layer utilizing the rectifying effect is formed by providing a charge transporting layer having a charge transporting ability of a polarity opposite to that of the electrode substrate utilizing the rectifying effect. As such a charge injection preventing layer, an inorganic photoconductive layer,
It is formed of an organic photoconductive layer and an organic-inorganic hybrid type photoconductive layer, and has a thickness of about 0.1 to 10 μm. Specifically, when the electrode is negative, amorphous silicon photoconductive layer doped with B, Al, Ga, In, etc., amorphous selenium photoconductive layer, polyvinyl carbazole photoconductive layer, or oxadiazole, pyrazoline, polyvinyl carbazole, Stilbene, anthracene, naphthalene, tridiphenylmethane, triphenylmethane, azine, amine,
An organic charge transport layer formed by dispersing an aromatic amine or the like in a resin, and P, N, As, Sb, B
amorphous silicon photoconductive layer doped with i, etc., Zn
An O photoconductive layer, a polyvinyl carbazole-trinitrofluorenone organic photoconductive layer, and the like are formed by a method such as glow discharge, vapor deposition, sputtering, CVD, and coating.

The photoreceptor support is not particularly limited in thickness and material as long as it has a certain strength capable of supporting the photoreceptor. For example, a flexible plastic film, metal foil, paper Alternatively, a rigid body such as a glass, a plastic sheet, or a metal plate (which can also serve as an electrode) is used. However, when used in a device that records information by irradiating light from the photoconductor side, it is naturally necessary to have the property of transmitting that light.For example, when using natural light as incident light and using it in a camera that enters from the photoconductor side Has a thickness of 1
A transparent glass plate of about mm or a plastic film or sheet is used.

The photoreceptor electrode is formed on the photoreceptor support except when a metal support is used for the photoreceptor support,
The material is not limited as long as the specific resistance value is 10 ⁶ Ω · cm or less, and examples thereof include an inorganic metal conductive film, an inorganic metal oxide conductive film, and an organic conductive film such as a quaternary ammonium salt. Such a photoreceptor electrode is formed on a photoreceptor support by vapor deposition, sputtering, CVD, coating, plating, dipping, electrolytic polymerization, or the like. The film thickness needs to be changed depending on the electrical characteristics of the material constituting the photoreceptor electrode and the applied voltage when recording information. For example, in the case of aluminum, it is about 100 to 3000 °. This photoreceptor electrode also needs the above-mentioned optical characteristics when it is necessary to transmit information light, similarly to the support. For example, if the information light is visible light (400 to 700 nm), the IT
Transparent electrodes such as O (In ₂ O ₃ -SnO ₂ ), SnO _2, etc., which are formed by sputtering, vapor deposition, or inking and coating fine powders thereof with a binder, Au, Al,
Translucent electrodes made of Ag, Ni, Cr, etc. by evaporation or sputtering, tetracyanoquinodimethane (TCN
Q), an organic transparent electrode with a coating of polyacetylene or the like is used.

The above-mentioned electrode material can also be used when the information light is infrared (700 nm or more) light. In some cases, a colored visible light absorbing electrode can be used to cut off visible light.

Further, when the information light is ultraviolet light (400 nm or less), the above electrode material can be basically used, but the electrode substrate material which absorbs ultraviolet light (organic polymer material,
Soda glass) is not preferred, and a material that transmits ultraviolet light, such as quartz glass, is preferred.

It is preferable to form an antireflection film on the light incident surface. This anti-reflection film can be formed by depositing an inorganic material such as magnesium fluoride, titanium oxide or the like in a single layer or by lamination by a sputtering method or the like.

Next, a method for recording information on the first information recording medium of the present invention will be described. FIG. 2 is a diagram for explaining a method of recording information on the information recording medium shown in FIG. 1, wherein 1 is a photoconductor, 5 is a photoconductive layer support, 7 is a photoconductor electrode, 9
Is a photoconductive layer, and 17 is a power supply.

First, a 1000 mm thick indium tin oxide (ITO) film was formed on a photoconductive layer support 5 made of glass having a thickness of 1 mm.
A transparent photoreceptor electrode 7 made of
The photoconductor 1 is formed by forming about m photoconductive layers 9.

As shown in FIG. 2A, an information recording medium 3 is arranged on the photosensitive member 1 with a gap of about 10 μm.

Next, a voltage is applied between the electrodes 7 and 13 by the power supply 17 as shown in FIG. In a dark place, the photoconductive layer 9 is a high-resistance body.

In this state, when light 18 is incident from the photoreceptor 1 side, the photoconductive layer 9 in the portion where the light is incident exhibits conductivity and becomes a low resistance body, an electric field acts on the information recording layer, and the information recording layer , The liquid crystal orientation occurs.

In forming information charges, since the operating voltage and the range may differ depending on the liquid crystal, the voltage distribution between the photosensitive member, the air gap, and the information recording medium is determined when setting the applied voltage and the applied voltage time. May be appropriately set, and the voltage distribution applied to the information recording layer may be set in the operating voltage region.

The method of recording information on an information recording medium according to the present invention is capable of performing planar analog recording and obtaining high resolution because alignment at the liquid crystal level is obtained, and the exposure pattern is variable depending on the alignment of the liquid crystal phase. It is visualized and held.

The information input method includes a method using a high-resolution electrostatic camera and a recording method using a laser. The information light may be incident from the photoconductor side or may be incident from the information recording medium side. First, a high-resolution electrostatic camera forms a recording member by a photoreceptor 1 and an information recording medium 3 in place of a photographic film used in a normal camera, and may use an optical shutter. A typical shutter may also be used.

Further, optical information is separated into R, G, and B light components by a prism and a color filter, extracted as parallel light, and R, G, and B separated into three information recording media.
Color photography can be performed by forming frames or by arranging R, G, and B images on one plane to form one frame in one set.

As a recording method using a laser, an argon laser (514.488 nm) is used as a light source,
A helium-neon laser (633 nm) or a semiconductor laser (780 nm, 810 nm, or the like) can be used. The photosensitive member and the information recording medium are brought into close contact with each other in a planar state, or they are opposed to each other at a certain interval, and a voltage is applied. In this state, laser exposure corresponding to the image signal, character signal, code signal, and line drawing signal is performed by scanning. Analog recording such as an image is performed by modulating the light intensity of a laser, and digital recording such as characters, codes, and line drawings is performed by ON-OFF control of a laser beam. In the case where halftone dots are formed in an image, the laser light is formed by performing dot generator ON-OFF control. Note that the spectral characteristics of the photoconductive layer in the photoreceptor need not be panchromatic, but may be any as long as they have sensitivity to the wavelength of the laser light source.

In addition, instead of the photoreceptor, corona charging, or a method in which a voltage is applied by a needle electrode or a pattern electrode in a contact or non-contact state, or information is recorded by an ion printer using an ion head. You can also.

The information recorded by the orientation of the liquid crystal is visible information that can be read visually, but can be read in an enlarged manner by a reflection type projector, and further reflected by laser scanning or CCD. Information can be read with high accuracy by reading with light or transmitted light.

The information recording medium of the present invention records electrostatic information in a state visualized by the orientation of liquid crystal, and has a memory property. This memory property is erased when the liquid crystal is heated to a temperature near its isotropic phase transition, and can be reused.

[0083]

The information recording medium of the present invention has a mixing weight ratio of nematic liquid crystal and smectic liquid crystal of 5/5.
By using a mixed liquid crystal of 95 to 20/80, the liquid crystal distribution inside the information recording layer can be made uniform, the variation in light transmittance can be reduced, and In manufacturing information recording media,
After coating the information recording layer with a mixed solution of the resin-forming material and the mixed liquid crystal on the electrode and drying it, place a smooth substrate on the coated surface and pressurize the coated layer uniformly, By forming the resin by curing the resin and then peeling the substrate, it is considered that the structure of the resin phase inside the information recording layer is made uniform and the variation in light transmittance is reduced.

When an ultraviolet curable resin material is used in particular as the resin, the outer surface layer of the information recording layer can be a skin layer composed of only a resin phase having no liquid crystal phase. The use ratio of the liquid crystal in the recording layer can be increased, and the exudation of the liquid crystal can be eliminated. Further, when used in an information recording method combined with a photoreceptor or the like, there is no disturbance of information recording by liquid crystal on the surface of the information recording layer, and there is no image unevenness.
A high-resolution image can be recorded and reproduced.

Each of the information recording media of the present invention can easily obtain an electro-optical effect, and can record and store analog information. When an electric field is not applied by an information charge, the liquid crystal phase is opaque due to light scattering. When an electric field is applied by an information charge, the liquid crystal phase is oriented and the information recording section is made transparent. Therefore, the optical system for reading can be simplified. Hereinafter, Examples will be described, in which the parts are by weight,
% Means% by weight.

[0086]

Example 1 Multifunctional monomer (dipentaerythritol hexaacrylate, manufactured by Toa Gosei Chemical Co., Ltd., M-40)
0) 40 parts, photocuring initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by Merck, Darocure 1173) 4 parts, and smectic liquid crystal (S-6 manufactured by Merck) as a liquid crystal A mixed liquid crystal composed of 90% and a nematic liquid crystal (E31LV manufactured by Merck) 10% was mixed with 50%.
Parts, and 3 parts of a surfactant (Fluorard FC-430, manufactured by Sumitomo 3M) were uniformly dissolved in 96 parts of xylene, and an ITO film was formed to a thickness of about 1000 angstroms by a sputtering method (1. (1 mm thick) on the ITO film side using a blade coater,
After drying under reduced pressure at 47 ° C. for 2 minutes, ultraviolet rays of 300 mJ / cm ² were immediately irradiated to cure the polyfunctional monomer. The thickness was 6 μm.

After the liquid crystal was extracted from the cross section of the information recording layer with hot methanol and dried, the internal structure was observed with a scanning electron microscope (S-800, manufactured by Hitachi, Ltd., 10000 times). However, the surface of the layer is covered with a UV-curable resin having a thickness of 0.6 μm, and the inside of the layer has a structure in which a liquid crystal phase forming a continuous layer is filled with a resin particle phase having a particle size of 0.1 μm. Was. The information recording layer was scanned with white light, and the amount of transmitted light was read by a CCD camera (C1000, manufactured by Hamamatsu Photonics KK). As a result, the variation in transmittance was within a range of an average value ± 6%. .

[0088]

Example 2 Multifunctional monomer (dipentaerythritol hexaacrylate, manufactured by Toa Gosei Chemical Co., Ltd., M-40)
0) 40 parts, photocuring initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by Merck, Darocure 1173) 4 parts, and smectic liquid crystal (S-6 manufactured by Merck) as a liquid crystal A mixed liquid crystal composed of 90% and a nematic liquid crystal (E31LV manufactured by Merck) 10% was mixed with 50%.
Parts, and 3 parts of a surfactant (Fluorard FC-430, manufactured by Sumitomo 3M) were uniformly dissolved in 96 parts of xylene, and an ITO film was formed to a thickness of about 1000 angstroms by a sputtering method (1. (1 mm thick) on the ITO film side using a blade coater,
After drying under reduced pressure at 47 ° C. for 2 minutes, place a quartz glass plate (film thickness: 1.0 mm) on the coated surface and immediately irradiate with 300 mJ / cm ² of ultraviolet light to obtain a polyfunctional monomer. After curing, the quartz glass was peeled off to produce an information recording medium of the present invention. When evaluated in the same manner as in Example 1, the variation in transmittance was ± 4.5% on average, and the variation in light transmittance was further reduced.

[0089]

Example 3 Polyfunctional monomer (dipentaerythritol hexaacrylate, manufactured by Toa Gosei Chemical Co., Ltd., M-40)
0), 40 parts of a photocuring initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by Merck Ltd.)
A mixture of 4 parts of Darocure 1173), 50 parts of smectic liquid crystal S-6 and 3 parts of surfactant FC-430 was uniformly dissolved in 100 parts of xylene, and the same evaluation test as in Example 2 was carried out. The average value was ± 6.5%.

[0090]

[Reference Example 1] Instead of the resin forming material in Example 1,
Using a thermosetting resin, bisphenol A resin (Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.) and an aliphatic curing agent (B-002, manufactured by Ibid.), And cured by heating to 60 ° C. An information recording medium was manufactured in the same manner as in Example 1.

When evaluated in the same manner as in Example 1, the variation in the transmittance was ± 0% on average and the variation in the light transmittance was low, but stain-like stains occurred on the information recording surface. As a result, bleeding of the liquid crystal occurred.

[0092]

Comparative Example 1 Multifunctional monomer (dipentaerythritol hexaacrylate, manufactured by Toa Gosei Chemical Co., Ltd., M-40)
0), 4 parts of a photo-curing initiator (2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by Merck, Darocure 1173) and 4 parts of a smectic liquid crystal (S-6 manufactured by Merck). 50 parts, surfactant (Fluorard FC-
430, manufactured by Sumitomo 3M) is uniformly dissolved in 100 parts of xylene, applied to the ITO film side of the substrate using a blade coater, dried at 50 ° C. for 2 minutes, and then decompressed at 50 ° C. for 2 minutes. Immediately after drying, 300 mJ / cm
^The polyfunctional monomer was cured by irradiating ultraviolet light of No. ² .
After that, when the evaluation was performed in the same manner as in Example 1, the variation in the transmittance was an average value ± 12%.

[0093]

Comparative Example 2 Multifunctional monomer (dipentaerythritol hexaacrylate, manufactured by Toa Gosei Chemical Co., Ltd., M-40)
0) 4 parts, photocuring initiator Darocur 1173 4 parts,
50 parts of nematic liquid crystal (E31LV manufactured by Merck) and 4 parts of surfactant Florad FC-430 in xylene 10
0 parts, uniformly coated on the ITO film side of the substrate using a blade coater, dried at 80 ° C. for 2 minutes, and then dried at 80 ° C. for 2 minutes under reduced pressure.
The polyfunctional monomer was cured by irradiating ultraviolet rays of J / cm ² . Thereafter, when the evaluation was performed in the same manner as in Example 1, the variation in the transmittance was an average value ± 20%.

Since the drying temperature is as high as 80 ° C.,
The compatibility between the monomer and the liquid crystal was increased, and the problem of a decrease in the electrical properties of the medium also occurred.

[0095]

Embodiment 4 (Preparation of photoreceptor) The charge generating material is represented by the following formula:

[0096]

Embedded image

3 parts of a bisazo pigment and 1 part of a polyvinyl acetal resin were mixed with dioxane: cyclohexane = 1: 1.
After a 100 g solution having a solid content of 2% in a mixed solvent of the above was sufficiently dispersed by a ball mill, the ITO transparent electrode (film thickness: about 5
00Å, glass substrate having a resistance value of 80Ω / sq.)
The coating was applied to the O side using a 2 mil gap blade coater and dried at 100 ° C. for 1 hour to form a 0.3 μm thick charge generating layer.

Next, 15 parts of p-diethylaminobenzaldehyde-N-phenyl-benzylhydrazone as a charge transporting material and 10 parts of a polycarbonate resin (trade name: Iupilon S-100, manufactured by Mitsubishi Gas Chemical Co., Ltd.) were mixed with 1.1: 1 dichloromethane. , 2-Trichloroethane = 4: 6 to adjust the solid content to 17.8%.
The resultant was coated on the above-mentioned charge generating layer with a blade coater having a mill gap thickness, and dried at 80 ° C. for 2 hours to form a charge transporting layer having a thickness of 10 μm, thereby producing an organic photoreceptor.

On the other hand, a DC voltage of 800 V was applied to the information recording medium in Example 1 with the photoreceptor prepared above and a polyester film having a thickness of 9 μm as spacers, with the photoreceptor side positive and the information recording medium side negative.

In a state where a voltage is applied, an illuminance of 10
Exposure using a 00-lux halogen lamp as a light source is 0.
This was performed for 1 second, and after the exposure was completed, the information recording medium was taken out, and the information recording was completed. The exposed portion became transparent, and the transmittance of this portion was 80%.

A normal camera was used as an exposure method, and in the same manner as described above, a photocopier was photographed outdoors and in the daytime with an exposure f = 1.4 and a shutter speed of 1/60 second with a voltage of 800 V applied through the gap. Was done. When the information recording medium was taken out after the exposure, an image having gradation was formed.

Further, the medium was read by a film scanner using a CCD sensor, and output by a sublimation transfer printer. As a result, a hard copy having gradation was obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an information recording medium of the present invention.

FIG. 2 is a diagram for explaining a method of recording information on an information recording medium according to the present invention.

[Explanation of symbols]

1 is a photoreceptor, 3 is an information recording medium, 5 is a photoconductive layer support,
7 is a photoreceptor electrode, 9 is a photoconductive layer, 11 is an information recording layer, 1
3 is an electrode layer, 15 is a substrate, 17 is a power supply, 18 is pattern exposure

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/13 505 G02F 1/1334 G03G 5/02

Claims (4)

(57) [Claims] 1. An information recording medium having an information recording layer laminated on a transparent electrode, wherein the information recording layer has a mixed weight ratio of a nematic liquid crystal and a smectic liquid crystal of 5/95 to 20 /.
80 and a UV-curable resin phase, and the outer surface of the information recording layer has
An information recording medium, wherein a skin layer made of an ultraviolet curable resin is formed . 2. After applying a mixed solution comprising a smectic liquid crystal and an ultraviolet curable resin on a transparent electrode , a smooth substrate having ultraviolet transmittance is placed on the applied surface, and the applied layer is uniformly pressed. by ultraviolet radiation to cure the ultraviolet curable resin, a phase and an ultraviolet curable consisting smectic liquid crystal
Has a structure separated from the resin phase, and has an ultraviolet light on the outer surface
Information recording layer with skin layer made of line-curable resin
And then peeling off the substrate. 3. A mixed liquid crystal having a mixing weight ratio of a nematic liquid crystal and a smectic liquid crystal of 5/95 to 20/80 and an ultraviolet ray.
After applying a mixed solution composed of a curable resin onto a transparent electrode, a flat substrate having ultraviolet transparency is placed on the applied surface, and the applied layer is pressed uniformly, and ultraviolet rays are irradiated by ultraviolet irradiation.
Curing the line-curable resin, nematic liquid crystal and Sumekuchi'
Liquid mixture with mixed liquid ratio of 5/95 to 20/80
Structure separated into crystalline phase and UV-curable resin phase
With a UV-curable resin on the outer surface.
Forming an information recording layer on which a recording layer is formed, and then peeling off the smooth substrate. 4. A on the transparent electrode and has a nematic liquid crystal and structure weight ratio is 5/95 to 20/80 mixture was phase-separated into a phase and a UV-curable resin phase consisting of the liquid crystal of the smectic liquid crystal, the UV curing on the outer surface of the information recording layer
An information recording medium in which an information recording layer in which a skin layer made of a mold resin is formed and a photoconductor in which a photoconductive layer is laminated on a transparent electrode are arranged to face each other, and an information recording medium electrode and a photoconductor electrode are disposed. Image exposure with a voltage applied during, to orient the liquid crystal phase in the information recording layer according to the exposure pattern,
Next, an information recording / reproducing method is characterized in that an exposure pattern is reproduced as visible information by transmitted or reflected light.