JP3197965B2 - 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 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 a reproducible information recording medium, and particularly to an information recording medium having excellent contrast when recording information.

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

[0010]

However, this type of information recording medium generally has a problem that a sufficient contrast cannot be obtained and a signal is insufficient.
SUMMARY OF THE INVENTION It is an object of the present invention to provide an information recording medium of this type which can obtain information having a high contrast ratio.

[0011]

According to a first information recording medium of the present invention, a skin layer comprising a liquid crystal phase and an ultraviolet-curable resin phase on an electrode layer and an outer surface layer of which is formed solely of an ultraviolet-curable resin. In an information recording medium provided with an information recording layer having a structure in which a resin particle is filled in a layer and a liquid crystal phase communicates between the layers, a dichroic dye is contained in the liquid crystal phase. And

Hereinafter, the information recording medium of the present invention will be described. FIG. 1A is a diagram for schematically explaining a cross section of the information recording medium of the present invention.
1 is an information recording layer, 13 is an electrode layer, and 15 is a substrate.

Next, the information recording layer 11 has a structure in which a liquid crystal phase and a resin phase are phase-separated. As the liquid crystal used in the present invention, smectic liquid crystal, nematic liquid crystal,
Alternatively, a mixed liquid crystal of these is used. From the viewpoint of recording retention (memory properties), a smectic liquid crystal or a mixed liquid crystal of a smectic liquid crystal and a nematic liquid crystal is preferable.

First, the smectic liquid crystal exhibits a smectic phase at room temperature (25 ° C.), and a cyanobiphenyl-based, cyanoterphenyl-based, phenylester-based substance having a long carbon chain at a terminal group of a substance exhibiting liquid crystallinity.
Further, a liquid crystal substance exhibiting a smectic A phase such as a fluorine-based liquid crystal 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, and the like can be given. 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 room temperature (25 ° C.), and is, for example, a Schiff base type, an azoxy type, an azo type, a phenyl benzoate type, a phenyl cyclohexylate. Known nematic liquid crystals such as ester, biphenyl, terphenyl, phenylcyclohexane, phenylpyridine, phenyloxazine, polycyclic ethane, phenylcyclohexene, cyclohexylpyrimidine, phenyl and tolane 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 5 / 95-20.
/ 80, and when the content of the nematic liquid crystal is less than 5% by weight, the variation in light transmittance is large, and
Exceeding the range is not preferred because the memory properties deteriorate and the variation in light transmittance increases. 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 Variation in rate can be reduced.

Next, the dichroic dye is dissolved in the liquid crystal,
It is preferable to select one that exists in the liquid crystal phase and hardly dissolves in the resin. A dichroic dye is one in which the molecular axis of the dye is oriented by the action of an electric field to change the absorbance. Specifically, SI-486 manufactured by Mitsui Toatsu Chemical Industry Co., Ltd.
_{(Λ max = 406nm in ZLI-} 1840, 397nm in Toluene, hereinafter the same), the _{SI-209 (λ max = 450nm} , 432nm), the M-
710 (λ _max = 468 nm, 445 nm), M-570 (λ _max = 45 nm)
1nm, 433nm), the _{M-361 (λ max = 477nm} , 474nm), the same
M-86 (λ _max = 514 nm, 510 nm, λ _max = 552 nm, 547 nm),
The _{M-370 (λ ma x =} 519nm, 514nm, λ max = 555nm, 558nm
), SI-455 (λ _max = 522 nm, 495 nm), SI-426
(Λ _max = 525 nm, 504 nm) and M-618 (λ _max = 544 nm,
527nm), the _{SI-252 (λ max = 572nm} , 550nm), the M-77
7 (λ _max = 577 nm, 552 nm) and S-432 (λ _max = 575 n)
m, 552 nm), the _{SI-512 (λ max = 587nm} , 580nm), the M-
137 (λ _max = 594 nm, 586 nm, λ _max = 639 nm, 623 nm),
M-141 (λ _max = 594 nm, 586 nm, λ _max = 639 nm, 623 nm
), M-483 (λ _max = 594 nm, 586 nm, λ _max = 640 nm, 6
M-412 (λ _max = 593 nm, 585 nm, λ _max = 639)
nm, 629 nm) and M-34 (λ _max = 593 nm, 585 nm, λ _max = 6)
40 nm, 629 nm), SI-497 (λ _max = 665 nm, 658 nm),
SI-501 (λ _max = 675 nm, 665 nm), M-403 (λ _max =
680 nm, 678 nm), the same S-344 (λ _max = 598 nm, 510 nm),
S-416 (λ _max = 625 nm, 507 nm) and S-426 (λ _max
= 505 nm, 505 nm) and S-428 (λ _max = 505 nm, 508 nm, λ)
_{max = 608nm, 530nm, λ max} = 587nm, 574nm, λ max = 632n
m, 622nm), the _{S-429 (λ max = 486nm} , 486nm, λ max =
_{540nm, 534nm, λ max = 587nm} , 575nm, λ max = 632nm, 620n
m) and S-435 (λ _max = 460 nm, 449 nm, λ _max = 582 nm, 5
80 nm, λ _max = 636 nm, 622 nm) and S-441 (λ _max = 474 n)
m, 467 nm, λ _max = 589 nm, 583 nm, λ _max = 633 nm, 620 nm).

Further, LCD-102 (λ) manufactured by Nippon Kayaku Co., Ltd.
_max = 645nm in Xylene, same hereafter), LCD-105
(Λ _max = 680 nm), LCD-109 (λ _max = 760 nm),
LCD-116 (λ _max = 670 nm), LCD-118 (λ _max =
630nm), LCD-121 ( _λmax = 630nm), LCD-122
(Λ _max = 680 nm), LCD-204 (λ _max = 520 nm),
LCD-208 (λ _max = 530 nm), LCD-209 (λ _max =
LCD-211 ( _λmax = 595nm (550nm))
), LCD-212 (λ _max = 535 nm (575 nm)), LCD-213
(Λ _max = 585 nm), LCD-307 (λ _max = 455 nm) and the like can also be used.

In addition, a dichroic dye Dye Mos. LSY-110, LSR-401, LSR-405, LSR-426
, LSB-278, LSB-350, LSB-335, and a dichroic dye Dye Mos. CLD-506, CLD-513, CL
D-514, CLD-515, CLD-516 and the like are also exemplified.

The first information recording medium preferably has a λ _max value of 300 nm to 500 nm in toluene. In the information recording layer of the second information recording medium to be described later, since the use of the near infrared region is useful, the λ _max value in toluene is 600 n.
It is preferable to use a dichroic dye having a wavelength of m to 900 nm.

The amount of the dichroic dye used for the liquid crystal is 0.1.
001% by weight to 5% by weight, desirably 0.01% by weight to
1% by weight is preferred. If the amount of the dichroic dye used is too large, the contrast can be increased, but the resistance value of the medium is reduced and the voltage is not effectively applied to the liquid crystal phase. On the other hand, if the addition amount is too large, the amount of the dye to be dissolved in the resin phase described later increases, and the dichroic dye does not work effectively. The volume resistivity of each information recording layer in the first information recording medium and the second information recording medium described later is 1 × 10 ¹⁰ Ω at room temperature.
cm or more, preferably 1 × 10 ¹¹ Ωcm or more.

Next, as a material forming the resin phase, a solvent-soluble resin having compatibility with a common solvent with the liquid crystal material,
For example, an acrylic resin, a methacrylic resin, a polyester resin, a polystyrene resin, and a copolymer containing these as a main component, or a monomer, an ultraviolet ray having compatibility with a liquid crystal material in a state of an oligomer or having compatibility with a common solvent, Radiation-curable resins, such as acrylates and methacrylates, and thermosetting resins, such as epoxy resins and silicone resins, may be used.

In particular, 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 oozing out of the liquid crystal are suppressed. Disturbance of an image due to seepage and a decrease in conductivity of the electrode layer can be prevented. UV-curable resins that are compatible with the liquid crystal material in the form of a monomer or oligomer, or that are compatible with a common solvent with the liquid crystal material in the form of a monomer or oligomer can be preferably used.

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.

As the solvent, there is no particular problem as long as it is a common solvent, but a solvent having a relative evaporation rate to n-butyl acetate of less than 2 may be used. For example, a hydrocarbon solvent represented by xylene or the like, Examples thereof include halogenated hydrocarbon solvents such as chloroform, alcohol derivative solvents such as 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 Ciba-Geigy) and 1-hydroxycyclohexylphenyl ketone (Ciba-Geigy). "Irgacure 184"), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1
-On (Caro Geigy Darocur 111
6 "), benzyldimethyl 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 (Nippon Kayaku Co., Ltd. “Kayacure DETX”) and ethyl p-dimethylaminobenzoate (Nippon Kayaku Co., Ltd. “Kayacure EPA”),
Isopropyl thioxanthone (a mixture of "Kuntacure ITX" manufactured by Ward Brekinsop and ethyl p-dimethylaminobenzoate, etc., and the like.
-Hydroxy-2-methyl-1-phenylpropane-1
-On is particularly preferred in terms of compatibility with liquid crystals and resin-forming materials such as polymer-forming monomers or oligomers.

The ratio of the liquid crystal to the resin forming material is such that the ratio of the liquid crystal is 10% to 90% by weight, preferably 40% by weight.
It is good to use so that it may be set to 80% by weight. 10% by weight
If it is less than 50%, the contrast ratio is low even if the liquid crystal phase is oriented by information recording. If it exceeds 90% by weight, phenomena such as bleeding of the liquid crystal occur, and image unevenness is not preferred.

The electrode layer 13 may be transparent or opaque, but has a specific resistance of 10 ⁶ Ω · cm or less, a conductive film of an inorganic metal oxide such as indium tin oxide, a quaternary ammonium salt, or the like. Organic conductive film. Electrode layer is evaporation, sputtering, CVD, coating, plating,
It is formed by a method such as dipping or electrolytic polymerization. Further, the film thickness needs to be changed depending on the electric characteristics of the material constituting the electrode and the applied voltage at the time of information recording.
For example, an ITO film has a thickness of about 100 to 3000 °, and is formed on the entire surface between the information recording layers or in accordance with the formation pattern of the information recording layers.

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 information is reproduced by transmitted light, the substrate needs to have transparency. In this case, the other surface of the substrate on which the electrode layer is provided is provided with antireflection if necessary. An anti-reflection property may be imparted by laminating layers having an effect, adjusting the transparent substrate to a film thickness capable of exhibiting an anti-reflection effect, or further combining them.

As will be described later, the information recording layer is formed by applying a resin-forming material, a liquid crystal, and a dichroic dye as a mixed solution on the electrode layer and curing the mixed solution. In addition, a fluorine-based surfactant is added for the purpose of forming a skin layer composed of only a resin on the surface of the information recording layer formed together with the improvement of the wettability to the electrode layer. Examples of such a fluorine-based surfactant include Florad FC-430, Florad FC-431, and N- (n-propyl) -N- (β-acryloxyethyl) -perfluoro manufactured by Sumitomo 3M Co., Ltd. Octylsulfonic acid amide [EF-125M manufactured by Mitsubishi Materials Corporation], N-
(N-propyl) -N- (β-methacryloxyethyl)
-Perfluorooctylsulfonic acid amide [EF-135M manufactured by Mitsubishi Materials Corporation], perfluorooctanesulfonic acid [EF-101 manufactured by Mitsubishi Materials Corporation],
Perfluorocaprylic acid [EF manufactured by Mitsubishi Materials Corporation]
-201], N- (n-propyl) -N-perfluorooctanesulfonic acid amide ethanol [EF-121 manufactured by Mitsubishi Materials Corporation], and EF-102, EF-103 manufactured by Mitsubishi Materials Corporation, and EF-103 manufactured by Mitsubishi Materials Corporation. EF-104, E
F-105, EF-112, EF-121, EF
-122A, EF-122B, EF-122C, EF-122A3, EF-123A, EF-123
B, EF-132, EF-301, EF-30
3, EF-305, EF-306A, EF-50
1, EF-700, EF-201, EF-20
4, EF-351, EF-352, EF-80
1, EF-802, EF-125DS, EF-1
200, EF-L102, EF-L155, EF
-L174 and EF-L215. Also,
3- (2-perfluorohexyl) ethoxy-1,2-
Dihydroxypropane [MF- manufactured by Mitsubishi Materials Corporation]
100], Nn-propyl-N-2,3-dihydroxypropyl perfluorooctylsulfonamide [MF-110 manufactured by Mitsubishi Materials Corporation], 3- (2-perfluorohexyl) ethoxy-1,2-epoxy Propane [MF-120 manufactured by Mitsubishi Materials Corporation], Nn-propyl-N-2,3-epoxypropyl perfluorooctylsulfonamide [MF-120 manufactured by Mitsubishi Materials Corporation]
130], 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 [Mitsubishi Materials Corporation MF-
160]. The fluorine-based surfactant is used in an amount of 0.1 to 0.1 based on the total amount of the liquid crystal, the resin-forming material, and the dichroic dye.
It is used in a proportion of 20% by weight. Also, if necessary,
A leveling agent may be added to improve the applicability of the solution and improve the surface properties.

Next, a method of forming the information recording layer will be described step by step. (1) A liquid crystal, a dichroic dye, a resin-forming material, 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, and the solid concentration is adjusted to 10 to 10.
The mixed solution is adjusted to 60% by weight. Solvent dilution is 1-50
0 cps (20 ° C.), preferably 10 to 200 cps
(20 ° C.). If the viscosity is low, the coating liquid flows and the film thickness after coating cannot be maintained, and if the viscosity is high, leveling becomes difficult. Further, the liquid crystal is heated and melted at a temperature higher than a temperature at which the liquid crystal maintains an isotropic phase, preferably within a temperature range of ± 10 ° C. of an isotropic phase transition point. At this time, the gelled material, dust and the like of the ultraviolet-curable resin-forming material present in the solution are removed by filtration. The presence of gelled matter, dust and the like causes noise as an information recording medium.

The mixed solution is heated to a temperature equal to or higher than the isotropic phase temperature in the preparation stage. At this time, if the solvent is evaporated and dried, the mixed solution is phase-separated. The information recording layer of the present invention is not formed. Therefore, a solvent having a relative evaporation rate of less than 2 with respect to n-butyl acetate is used as the solvent. If the relative evaporation rate is greater than 2, evaporation will be too fast, causing the above problem. Usually 70 ° C
If the solvent can be dissolved by heating up to
Is not less than 0.3 and not more than 1. For example, xylene (R = 0.7) may be used, and when heating at 70 ° C. or more is required for dissolution, R Is less than 0.3, for example, cyclohexanone (R = 0.2).

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

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

(4) In order to complete the removal of the solvent, the drying treatment is preferably performed in two stages, food drying and vacuum drying, thereby preventing the information recording layer surface from being uneven due to the flow of air. In addition, interference fringes can be prevented.

(5) Next, the dried coating layer is subjected to UV irradiation.
The coating layer is irradiated with ultraviolet light by using a lamp and cured.
An information recording layer having excellent phase separation between a liquid crystal phase and a resin phase can be obtained by irradiating with ultraviolet light having a wavelength portion of 1% or more from 00 nm to 400 nm at an energy of 0.1 mJ / cm ² or more. .

When the information recording layer is formed as described above,
On the surface of the information recording layer, 0.01% to 3% of the thickness of the information recording layer
A skin layer having a thickness of 0% is formed, and the inside of the information recording layer has a primary particle size of 0.03 μm to 0.2 μm.
A structure in which resin particles of 3 μm are filled and a liquid crystal phase is communicated therebetween can be obtained. When a polyfunctional ultraviolet-curable resin material having a parameter represented by average molecular weight / average functional group of 160 or less is used as the ultraviolet-curable resin-forming material, the surface skin layer can have excellent durability.

By forming a durable skin layer on the surface of the information recording layer, the use ratio of the liquid crystal in the information recording layer can be increased. As a result, image disturbance 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,
If the phase separation is incomplete, the information recording layer itself will have low resistance, and when recording information by the action of an electric field by electrostatic information using an optical sensor, no voltage is applied to the liquid crystal phase in the information recording layer effectively. In addition, there is a problem that the liquid crystal drive becomes slow and the sensitivity is lowered. Also, if the phase separation is incomplete, when the UV-curable resin-forming material is irradiated by a UV lamp containing infrared rays, unnecessary heating causes non-uniform shrinkage. There is a serious problem that the recording layer cannot be used.

(6) The information recording layer thus formed has an average thickness of 1 μm to 30 μm. If the film thickness is too large, the operating voltage increases. However, in general, it is preferable to reduce the film thickness in order to increase the sensitivity, and to increase the film thickness in order to increase the contrast. In order to obtain an excellent contrast ratio along with the sensitivity, the film thickness is preferably 3 μm.
The thickness is preferably from 20 to 20 μm, more preferably from 5 to 10 μm. Thus, the operating voltage can be reduced while maintaining high contrast.

The thickness of the skin layer in the information recording layer can be in the range of 0.01% to 50% of the thickness of the information recording layer. Even if information is recorded by an optical sensor that emits light, noise occurs. Therefore, it is preferable that the thickness of the skin layer is 0.01% to 30% of the thickness of the information recording layer. The thickness of the skin layer can be appropriately adjusted by the type of the ultraviolet-curable resin, the amount of ultraviolet irradiation, the addition of a fluorine-based surfactant, and the like, although the detailed reason is unknown.

Further, in the information recording medium of the present invention,
It is necessary that the thickness of the information recording layer be accurately and uniformly applied. However, by forming the information recording layer by the above method, the uniformity of the film thickness can be improved when the film thickness is 5 μm to 10 μm. Has a surface roughness Ra of 200 ° or less, has no contrast unevenness, and does not cause a shading phenomenon even during information recording.

In general, in the case of this type of polymer-dispersed liquid crystal, it is considered that the resolution depends more on the domain size of the liquid crystal than on the film thickness. When the content of the liquid crystal is large, such as a layer, and the resin forms a phase in the form of particles, the domain size of the liquid crystal is considered very much, as in the case of a polymer-dispersed liquid crystal in which the content of the normal liquid crystal is low. Since there is no need, it is possible to easily provide an information recording medium having high sensitivity and a high contrast ratio.

After a mixed solution of the resin forming material and the liquid crystal is applied and dried, a smooth substrate such as a quartz glass plate is placed on the applied surface, and the ultraviolet light is applied while uniformly pressing the applied layer. When the curable resin is cured by irradiation, and then the substrate is peeled off to obtain an information recording medium, an information recording layer with less variation in light transmittance can be obtained.

Next, a method for recording information 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, or corona charging. Preferably, the information is recorded using an optical sensor. Such an optical sensor is formed by laminating an electrode layer and a photoconductive layer on a transparent substrate, and the photoconductive layer is a single layer having both a charge generation function and a charge transport function according to information light. And a layered system in which a charge generation layer and a charge transport layer are sequentially laminated on an electrode layer, and are formed by the same material and a forming method as a photoconductive layer in a second information recording medium described later. You. The photoconductive layer generally has a function of generating photocarriers (electrons and holes) at an irradiated portion when irradiated with light, and the carriers can move the layer width. This layer has a remarkable effect when present. As such an optical sensor, for example, Japanese Patent Application No. 4-2879
No. 83. In the optical sensor described in this publication, the electric field or electric charge applied to the information recording medium at the time of light irradiation is amplified with light irradiation, and the conductivity is maintained when a voltage is continuously applied even after the light irradiation is completed. It has a function of sustaining and continuously applying an electric field or a charge amount to the information recording medium.

FIG. 2 shows an information recording apparatus incorporating an optical sensor. In the figure, 1 is an optical sensor, 3 is an information recording medium, 1
3, 13 'are electrode layers, 11 is an information recording layer, 14 is a photoconductive layer, 15 is a substrate, 19 is a spacer, 21 is a light source, 22
Denotes a shutter having a driving mechanism, 23 denotes a pulse generator (power supply), and 24 denotes a dark box.

When information light is incident from the light source 21 while a voltage is applied by the pulse generator 23 between the electrodes 13 and 13 ′, the photocarriers generated in the photoconductive layer 14 at the portion where the light is incident are applied to both electrodes. Move to the interface on the information recording layer 11 side by the electric field formed by the above, the voltage is redistributed, the liquid crystal phase in the information recording layer 11 is oriented, and the recording according to the information light pattern is performed. In the figure, the photoconductor side is a positive electrode and the information recording medium side is a negative electrode. However, it goes without saying that the polarity is set according to the discharge characteristics of the optical sensor.

When setting the applied voltage, some liquid crystal materials operate at a low voltage. Therefore, the voltage distribution of the optical sensor, the air gap, and the information recording medium is appropriately set and applied to the information recording layer. The voltage may be set in its operating voltage range. Information recording by this optical sensor can be performed in the form of planar analog recording, and the liquid crystal phase can be oriented at the level of electrostatic charge.
A high resolution similar to that of silver salt photography is obtained, and the exposure pattern is kept visible by the orientation of the liquid crystal phase.

As a method for inputting information to the first information recording medium of the present invention, there are a method using a camera and a method using a laser. As a method using a camera, an information recording medium is used instead of a photographic film used in a normal camera, and a recording member is used. An optical shutter can be used, and an electric shutter can also be used. It is a good thing. Further, the optical information is separated into R, G, and B light components by a prism and a color filter, extracted as parallel light, and one frame is formed by three sets of R, G, and B information recording media, or on one plane. By arranging the R, G, and B images side by side to form one frame in one set, color photography can also be performed.

Further, as a recording method using a laser,
As a light source, an argon laser (514.488n)
m), helium-neon laser (633 nm), 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. 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.

When the electrostatic information recorded on the information recording medium is reproduced by transmitted light as shown in FIG. 3, light A is transmitted because the liquid crystal is oriented in the direction of the electric field in the information recording portion. On the other hand, the light B is scattered in a portion where information is not recorded, and a 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 with transmitted light, but can also be read by enlarging with a projector, and is read with laser scanning or transmitted light using a CCD. Thus, information can be read with high accuracy, and scattered light can be prevented by using a schlieren optical system as needed. Further, it can be read by reflected light. If contrast is a problem, a reflective layer may be provided on any of the layers.

Next, a second information recording medium of the present invention will be described. The second information recording medium has a photoconductive layer incorporated in the first information recording medium, and does not require an optical sensor or the like when recording information, and can record information by itself.

FIG. 1B is a diagram for schematically explaining the cross section, in which 3 is an information recording medium, 11 is an information recording layer, 13 and 13 'are electrode layers, and 14 is a photoconductive layer. , 15 are substrates.

Photoconductive layer 14 laminated on electrode 13 '
Are classified into a single layer type and a multilayer type in which a charge generation layer and a charge transport layer are stacked. The photoconductive layer generally has a function of generating photocarriers (electrons and holes) at an irradiated portion when irradiated with light, and the carriers can move the layer width. This layer is a layer whose effect is remarkable when it is present. In particular, the electric field applied to the information recording layer when the photoconductive layer is irradiated with light is amplified as the light is irradiated, and the voltage is increased even after the light irradiation is completed. It is preferable to have a function of maintaining the conductivity by continuously applying the electric field and continuously applying an electric field to the information recording medium.

First, a single-layer photoconductive layer is formed from an inorganic photoconductive substance or an organic photoconductive substance. Se, Se—Te, ZnO, Ti as the inorganic photoconductive substance
O _2, Si, CdS, and the like, a vapor deposition method, a sputtering method, the electrode layer by a CVD method or the like, 5 to 30 [mu] m, alone or mixed system, is laminated preferably in a thickness of 20 to 30 [mu] m. Further, the above-mentioned inorganic photoconductor as fine particles, an organic insulating resin, for example, a silicone resin, a polyester resin, a polycarbonate resin, a styrene-butadiene resin, a styrene resin, a polyvinyl acetal resin may be dispersed to form a photoconductive layer, In this case, the photoconductive fine particles may be dispersed in a proportion of 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 1 part by weight of the resin.

The organic photoconductive material includes a polymer photoconductive material and a dispersion of a low molecular weight photoconductive material in an insulating binder. Examples of the polymer photoconductive substance include polyvinyl carbazole (PVK), and poly-N-ethylenically unsaturated group substitution containing an ethylenically unsaturated group such as an allyl group or an acryloxyalkyl group instead of a vinyl group in PVK. There are also carbazoles, poly-N-ethylenically unsaturated group-substituted phenothiazines such as poly-N-acrylphenothiazine, poly-N- (β-acryloxy) phenothiazine, polyvinylpyrene and the like. Among them, poly
N-ethylenically unsaturated group-substituted carbazoles, particularly polyvinyl carbazole, 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, and a stilbene derivative. One 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, and 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 materials after drying is 5 to 30 μm, preferably 10 to 30 μm.
m on the electrode.

The organic photoconductive layer may be added with a sustained conductivity imparting agent described in Japanese Patent Application No. 4-287983 if necessary. The above-mentioned organic photoconductive layer itself has sustained conductivity, and this persistent conductivity imparting agent is added for the purpose of enhancing the sustained conductivity in the above-mentioned organic photoconductive layer. The sustaining conductivity imparting agent is 0.001 to 1 part by weight based on 1 part by weight of the organic photoconductive substance,
Preferably, it is added in a ratio of 0.001 to 0.1 parts by weight. When the amount of the sustained conductivity-imparting agent exceeds 1 part by weight,
This is not preferable because the amplifying function of the photoconductive layer is significantly reduced. Also, some sustained conductivity-imparting substances do not have spectral sensitivity in visible light, and when utilizing light information in the visible light region, an electron-accepting material is used 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 a triphenylmethane dye, a pyrylium salt dye, and a xanthene dye. Electron accepting substances, sensitizing dyes, etc.
0.001 to 1 part by weight, preferably 0.01 to 1 part by weight, is added to 1 part by weight of the organic photoconductive substance. At the same time, if the optical information is in the infrared region, it is advisable to add the same amount of a pigment such as phthalocyanine, a pyrrole-based dye, or a cyanine-based dye, and conversely, there is information light in the ultraviolet region or in a wavelength region below it In this case, the purpose is achieved by adding the same amount of each wavelength absorbing substance.

Next, the laminated photoconductive layer is formed by sequentially laminating a charge generation layer and a charge transport layer on an electrode, and includes an inorganic material type photoconductive layer and an organic material type 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 to a thickness of 0.05 μm to 1 μm by an evaporation method, a sputtering method, a CVD method, or the like. Next, on this charge generation layer, Se, As
_It is preferable to form a layer of 10 μm to 50 μm in thickness in the same manner, for example, by doping ₂ Se ₃ , Si, Si or the like doped with methane.

Next, the charge generation layer in the organic system is composed of a charge generation material 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 And anthantrone pigments, cyanine pigments, polycyclic quinone pigments, imidazole pigments and the like, and specific examples thereof include charge generation substances described in Japanese Patent Application No. 4-287983.

Examples of the binder include a silicone resin, a styrene-butadiene copolymer resin, an epoxy resin, an acrylic resin, a saturated or unsaturated polyester resin, a PMMA resin, a vinyl chloride resin, a vinyl acetate resin, and a vinyl chloride-vinyl acetate mixed resin. And formed by dispersing the charge generating material in a binder. The charge generator 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. The mixing ratio of the charge generating agent and the binder is preferably 0.1 to 10 parts by weight, and more preferably 0.1 to 1 part by weight, per 1 part by weight of the charge generating agent. The charge generation layer has a thickness of 0.01 to 1 μm after drying, preferably 0.1 to 1 μm.
It is good to be 0.3 μm.

The charge transport layer comprises a charge transport substance and a binder. The charge transport substance is a substance having a good charge transport property of the charge generated by the charge generation substance, for example, a hydrazone type,
There are pyrazoline type, PVK type carbazole type, oxazole type, triazole type, aromatic amine type, amine type, triphenylmethane type, butadiene type, stilbene type, polycyclic aromatic compound type, etc. It is necessary to. Preferred are butadiene-based and stilbene-based charge transport agents.
And the charge transport materials described in JP-A-289833.

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

Examples of the combination of the charge generating substance and the charge transporting substance 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, and a hydrazone type. And the like are good.

The sustaining conductivity-imparting agent and the electron-accepting substance described in the section of the single-layer photoconductive layer are added to the charge generating layer and the charge transporting layer in the stacked photoconductive layer at the same ratio. However, it is preferably added to the charge generation layer.

When the single-layer photoconductive layer and the laminated photoconductive layer are organic photoconductive layers, dichloroethane, 1,1,2-trichloroethane, monochlorobenzene, tetrahydrofuran, cyclohexane, dioxane, and dioxane are used as solvents. , 2,3-trichloropropane, ethyl cellosolve, 1,1,1, -trichloroethane, methyl ethyl ketone, chloroform, toluene, etc., and the coating solution may be used. The coating method includes a blade coating method, a dipping method, and a spinner. Coating methods and the like can be mentioned.

The photoconductive layer may be provided on the electrode via a charge injection control layer. The charge injection control layer is provided as needed, and is provided for controlling the charge injection property from the electrode to the photoconductive layer to 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 operation region of the liquid crystal. It is necessary.

[0068] Therefore, for example, the dark potential across the liquid crystal layer in the unexposed portions of the photoconductive layer must be set to about the operation start voltage of the liquid crystal, Hikarishirubedenso bulk 10 ⁵ V / cm to 10
10 ⁻⁴ to 10 ⁻⁸ A in a state where an electric field of ⁶ V / cm is applied
/ Cm ² is required to have a conductivity sufficient to generate a dark current, and is preferably in the range of 10 ⁻⁵ to 10 ⁻⁶ A / cm ² .
In a photoconductive layer having a dark current of 10 ⁻⁸ A / cm ² or less, the liquid crystal layer is not oriented even in an exposed state, and in a photoconductive layer having a dark current of 10 ⁻⁴ A / cm ² or more, voltage is applied even in an unexposed state. At the same time, a large amount of current flows, the liquid crystal in the information recording layer is oriented, and even when exposed, there is no difference in transmittance. The charge injection control layer is appropriately provided in relation to such characteristics of the information recording medium. When it is necessary to keep the dark potential of the photoconductive layer low, the charge injection control layer is a layer having charge injection prevention properties. As the charge injection preventing layer, there are two types, that is, a layer using a so-called tunneling effect and a layer using a rectifying effect, and those described in Japanese Patent Application No. 4-287983 can be used.

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

In the second information recording medium, since the liquid crystal does not exude from the surface of the information recording layer in the present invention, the electrode is directly applied to the surface of the information recording layer. The layer 13 can be formed by vapor deposition by a sputtering method, and an electrode layer without a decrease in conductivity can be formed.

The electrode layer 13 can be made of the same material as the electrode layer described in the first information recording medium. However, since a skin layer made of only resin is formed on the surface of the information recording layer, for example, an ITO film By evaporation, sputtering, etc.
An electrode free of cracks or the like can be formed even when the electrode is laminated to a thickness of 00 °. One or both of the electrode layers 13 and 13 'may be transparent. Note that a substrate similar to that in the first information recording medium may be stacked on the electrode 13.

Next, in the second information recording medium, a transparent insulating layer may be provided between the photoconductive layer 14 and the information recording layer 11. When a transparent insulating layer is provided, the photoconductive layer is particularly suitable for an organic photosensitive layer formed using a solvent, and liquid crystals in the information recording layer are eluted due to the interaction between the photoconductive layer and the information recording layer. Also, when the information recording layer is formed on the photoconductive layer by coating, the photoconductive material is eluted by the solvent for forming the information recording layer, and is provided for the purpose of preventing the occurrence of image unevenness.

Therefore, in forming the transparent insulating layer, it is necessary that the transparent insulating layer has no compatibility with any of the organic photoconductive layer forming material and the information recording layer forming material. Since the space charge is diffused and the resolution is deteriorated, the insulating property is required. However, since the transparent insulating layer lowers the distribution voltage applied to the liquid crystal layer or deteriorates the resolution, the film thickness is preferably thinner, and is preferably 2 μm or less. Further, when the thickness is reduced, not only the occurrence of image noise due to the interaction with time, but also the problem of permeation due to defects such as pinholes during lamination coating occurs. Since the permeability varies depending on the solid content ratio of the material to be layer-coated, the type of solvent, and the viscosity, the film thickness of the layer-coated material is appropriately set. In order to prevent these problems, the following materials can be laminated and used. Further, 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.

Such a transparent insulating layer is used as an inorganic material.
_{SiO 2, TiO 2, CeO 2} , Al 2 O 3, GeO 2, Si 3 N 4, AlN, Ti
It may be formed by laminating N 2 and the like by a vapor deposition method, a sputtering method, a chemical vapor deposition (CVD) method, or the like. Further, an aqueous solution such as polyvinyl alcohol, water-based polyurethane, or water glass may be used as a water-soluble resin having low compatibility with an organic solvent, and may be laminated by a spin coating method, a blade coating method, a roll coating method, or the like. Further, a fluorine resin which can be applied may be used. In this case, the resin may be dissolved in a fluorine-based solvent and applied by a spin coating method, or may be laminated by a blade coating method, a roll coating method or the like. As the fluorine resin which can be applied, the fluorine resin described in Japanese Patent Application No. Hei 4-24722 can be suitably used. When selecting a coating type transparent insulating material, the solvent does not dissolve the photoconductive layer, and does not dissolve in the material constituting the information recording layer when forming and coating the information recording layer, or when the coating is performed. It is necessary not to dissolve in the solvent.

In the case of an organic material formed in a vacuum system, there is no possibility of dissolving the photoconductive layer during film formation. Among these materials, polyethylene, polypropylene, poly (monochlorotrifluoroethylene), polytetrafluoroethylene, etc. can be used as a material to be formed by a vapor deposition method.
In addition, as a material for forming a film by the CVD method, polyparaxylene or the like specifically described in Japanese Patent Application No. 4-24722 can be used. Note that when 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 a transparent insulating layer.

Next, a second method for recording and reproducing information on an information recording medium according to the present invention will be described. FIG. 4 is a diagram for explaining an information recording method. When the information light 18 enters while applying a voltage between the electrodes 13 and 13 ′, the photocarriers generated in the photoconductive layer 14 in the portion where the light has entered move due to the electric field formed by both electrodes, and the voltage By performing the redistribution, the liquid crystal phase in the information recording layer is oriented, 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.

Further, since the operating voltage and the range vary depending on the liquid crystal, 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 liquid crystal. It is preferable to set the operation voltage range.

In this information recording method, planar analog recording is possible, and recording at the liquid crystal particle level is obtained, so that a high resolution is obtained. Further, the exposure pattern is visualized and maintained by the orientation of the liquid crystal phase. Is done.

As a method for inputting information to the information recording medium, a method similar to the method using a camera or the method using a laser described in the section of the first information recording medium can be used. In addition, the same can be performed as a recording method using a laser, but the spectral characteristics of the photoconductive layer in this information recording medium need not be panchromatic, as long as they have sensitivity to the wavelength of the laser light source. . The information recorded on the second information recording medium is reproduced in the same manner as in the case of the first information recording medium shown in FIG.

The first and second information recording media of the present invention are used by being cut in an appropriate size in the layer width direction according to the usage mode. The inside of the layer is exposed, and the liquid crystal phase exudes during storage. When this bleeding phenomenon occurs, there occurs a problem that when information is recorded, accurate information recording cannot be performed at the end of the information recording medium. In order to prevent this, after the information recording medium is cut into an appropriate shape, a resin layer may be similarly laminated on the cut surface by a coating method or a 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. Oriented and visualized information is not erased, providing memory. The memory may be erased by heating to a high temperature near the isotropic phase transition, and can be used again for information recording.

[0082]

The information recording medium composed of a liquid crystal phase and a resin phase can easily obtain an electro-optical effect and can record and store analog information.
In addition, since the information recording layer can be uniformly thinned by a coating technique, a large-area information recording medium can be manufactured, and a high-resolution image can be recorded and reproduced. In the information recording layer, by setting the optical refractive index of the liquid crystal and the optical refractive index of the resin body to be substantially the same, the liquid crystal becomes opaque by light scattering in a state where an electric field is not applied by an information charge, and the liquid crystal is applied by an electric field. The phase is oriented, and the information recording portion can be made transparent. The information reproducing device does not require a deflecting plate, and the reading optical system can be simplified.

In the first information recording medium of the present invention, by including a dichroic dye in the information recording layer composed of such a liquid crystal phase and a resin phase, the information recording layer is formed of only the liquid crystal phase and the resin phase. As compared with the case where the charge or electric field is not applied, the transmittance is further reduced to make the film opaque, and when the charge or the electric field is applied, the dichroic dye ( Since the guest) itself is also oriented, the absorbance can be made more different, so that an excellent information recording medium with high contrast can be obtained.

Further, in the second information recording medium, since the liquid crystal does not bleed out on the surface of the information recording layer, an electrode layer can be provided on the surface by a sputtering method or the like. Can be prevented, so that a decrease in conductivity can be prevented. In addition, since it has a photoconductive layer, it is not necessary to combine it with an optical sensor, and information can be recorded by itself.

Hereinafter, the present invention will be described with reference to examples.

[0086]

[Example 1] Smectic liquid crystal S-6 (manufactured by Merck) 5 parts by weight Nematic liquid crystal E-31LV (manufactured by Merck) 0.5 parts by weight UV curable resin M-400 (Toa Gosei Chemical) 4.5 parts by weight-Photopolymerization initiator Darocure 1173 (manufactured by Ciba-Geigy) 0.25 parts by weight-Dichroic dye SI-486 (azo type) (Mitsui Toatsu Chemical Industry Co., Ltd.) )) ・ ・ 0.01 parts by weight ・ Surfactant Florad FC-430 (Sumitomo 3M) ・ ・ 0.1 parts by weight dissolved in xylene (special grade of reagent manufactured by Junsei Chemical Co., Ltd.) to 50 parts by weight % Of the solution, and the solution was sputtered on a glass substrate having a thickness of 1 mm to form an ITO electrode of 1000%.
Was applied on a glass substrate electrode formed by lamination with a film thickness of 10 seconds using a spinner (10 seconds, 300 rpm). And
It was placed in a 47 ° C. vacuum dryer, left for 3 minutes, evacuated for 2 minutes, and then returned to normal pressure to remove the solvent.

Next, ultraviolet rays having an energy of 600 mJ / cm ² were irradiated to obtain a medium having an information recording layer having a thickness of 6 μm. The transmittance of this medium at 600 nm is 38.
% And the volume resistivity at room temperature was 2 × 10 ¹¹ Ωcm.

Further, a liquid crystal was extracted from the cross section of the information recording layer using hot methanol, dried, and then subjected to a scanning electron microscope (S-800, 10000, manufactured by Hitachi, Ltd.).
Observation of the internal structure, the surface of the layer was 0.6μ
The layer was covered with a m-thick ultraviolet-curable resin, and the inside of the layer had a structure in which a resin particle phase having a particle diameter of 0.1 μm was filled in a liquid crystal phase forming a continuous layer.

[0089]

Example 2 Smectic liquid crystal S-6 (Merck) 5 parts by weight Nematic liquid crystal E-31LV (Merck) 0.5 part by weight UV curable resin M-400 (Toa Gosei Chemical) 4.5 parts by weight-Photopolymerization initiator Darocure 1173 (manufactured by Ciba-Geigy) 0.25 parts by weight-Dichroic dye M-34 (anthraquinone-based) (Mitsui Toatsu Chemical Industry Co., Ltd.) 0.01 parts by weight Surfactant FC-430 (manufactured by Sumitomo 3M) 0.1 part by weight is dissolved in xylene (special grade reagent manufactured by Junsei Chemical Co., Ltd.) and 50 parts by weight % Of the solution, and this solution was coated with a 100 mm ITO electrode on a 1 mm thick glass substrate by sputtering.
On a glass substrate electrode formed by laminating with a thickness of 0 °,
Apply with a spinner (10 seconds, 300 rpm), 47 ° C
After leaving in a vacuum dryer for 3 minutes and evacuating for 2 minutes, the pressure was returned to normal pressure and the solvent was removed.

Next, the medium was irradiated with ultraviolet rays having an energy of 600 mJ / cm ² to obtain a medium having an information recording layer having a thickness of 6 μm. This medium has a transmittance of 42% at 600 nm and a volume resistivity at room temperature of 2 × 10 ¹¹ Ωc.
m.

[0091]

Example 3 Smectic liquid crystal S-6 (manufactured by Merck) 5 parts by weight Nematic liquid crystal E-31LV (manufactured by Merck) 0.5 part by weight UV-curable resin M-400 (Toa Gosei Chemical) 4.5 parts by weight-Photopolymerization initiator Darocure 1173 (manufactured by Ciba-Geigy) 0.25 parts by weight-Dichroic dye SI-486 (azo type) (Mitsui Toatsu Chemical Industry Co., Ltd.) 0.03 parts by weight Surfactant FC-430 (manufactured by Sumitomo 3M) 0.1 parts by weight dissolved in xylene (manufactured by Junsei Chemical Co., Ltd., reagent special grade) to 50 parts by weight % Of the solution, and this solution was coated with a 100 mm ITO electrode on a 1 mm thick glass substrate by sputtering.
On a glass substrate electrode formed by laminating with a thickness of 0 °,
Apply with a spinner (10 seconds, 300 rpm), 47 ° C
After leaving in a vacuum dryer for 3 minutes and evacuating for 2 minutes, the pressure was returned to normal pressure and the solvent was removed.

Next, the medium was irradiated with ultraviolet rays having an energy of 600 mJ / cm ² to obtain a medium having an information recording layer having a thickness of 6 μm. The transmittance of the medium at 600 nm is 25.
% And the volume resistivity at room temperature was 1 × 10 ¹¹ Ωcm.

[0093]

[Comparative Example 1] Smectic liquid crystal S-6 (manufactured by Merck) 5 parts by weight Nematic liquid crystal E-31LV (manufactured by Merck) 0.5 part by weight UV curable resin M-400 (Toa Gosei Chemical) 4.5 parts by weight-Photopolymerization initiator Darocur 1173 (manufactured by Ciba-Geigy) 0.25 parts by weight-Surfactant Florard FC-430 (manufactured by Sumitomo 3M) 0.1 parts by weight Was dissolved in xylene (special grade reagent, manufactured by Junsei Chemical Co., Ltd.) to prepare a 50% by weight solution, and this solution was sputtered on a glass substrate having a thickness of 1 mm to form an ITO electrode having a thickness of 100%.
On a glass substrate electrode formed by laminating with a thickness of 0 °,
Apply with a spinner (10 seconds, 300 rpm), 47 ° C
After leaving in a vacuum dryer for 3 minutes and evacuating for 2 minutes, the pressure was returned to normal pressure and the solvent was removed.

Next, this medium was irradiated with ultraviolet rays having an energy of 600 mJ / cm ² to obtain a medium having an information recording layer having a thickness of 6 μm. The volume resistivity at room temperature of this medium was 2 × 10 ¹¹ Ωcm, but the transmittance at 600 nm was as high as 46%, and when no dichroic dye was contained,
It can be seen that the transmittance increases.

[0095]

[Comparative Example 2] Smectic liquid crystal S-6 (manufactured by Merck) 5 parts by weight Nematic liquid crystal E-31LV (manufactured by Merck) 0.5 part by weight UV curable resin M-400 (Toa Gosei Chemical) 4.5 parts by weight-Photopolymerization initiator Darocure 1173 (manufactured by Ciba-Geigy) 0.25 parts by weight-Dichroic dye SI-486 (azo type) (Mitsui Toatsu Chemical Industry Co., Ltd.) )) 1 part by weight Surfactant FC-430 (manufactured by Sumitomo 3M) 0.1 part by weight was dissolved in xylene (special grade reagent, manufactured by Junsei Chemical Co., Ltd.) to give 50% by weight. A solution was prepared, and this solution was coated on a glass substrate having a thickness of 1 mm with an ITO electrode by sputtering.
On a glass substrate electrode formed by laminating with a thickness of 0 °,
Apply with a spinner (10 seconds, 300 rpm), 47 ° C
After leaving in a vacuum dryer for 3 minutes and evacuating for 2 minutes, the pressure was returned to normal pressure and the solvent was removed.

Next, this medium was irradiated with ultraviolet rays having an energy of 600 mJ / cm ² to obtain an information recording medium having a thickness of 6 μm. Although the transmittance of the medium at 600 nm was 10%, the volume resistivity at room temperature was as low as 5 × 10 ⁸ Ωcm, and when the amount of the dichroic dye used was large, the volume resistivity was lowered. I understand.

[0097]

Example 4 An ITO film having a thickness of 1000 Å was formed on a sufficiently cleaned glass substrate having a thickness of 1.1 mm by a sputtering method to obtain an electrode layer. On the electrode, the following structure as a charge generating agent

[0098]

Embedded image

3 parts by weight of a fluorenone azo pigment having a polyester resin (manufactured by Toyobo Co., Byron 2)
00) 1 part by weight, 98 parts by weight of 1,4-dioxane and 98 parts by weight of anone were mixed, and the mixture was mixed for 6 hours with a paint shaker.
Disperse into a coating liquid, and spin at 1400 rpm,
After coating for 0.4 sec, 100 ℃, 1hr
After drying, a charge generating layer having a thickness of 3000 ° was laminated.

On this charge generating layer, a charge transport agent having the following structure

[0101]

Embedded image

Using 25 parts by weight of paradimethylstilbene, a polystyrene resin (manufactured by Denka Co., HRM-
3) A coating liquid obtained by mixing 5 parts by weight, 102 parts by weight of 1,1,2-trichloroethane and 68 parts by weight of dichloromethane,
After coating with a spinner at 300 rpm and 0.3 msec, the resultant was dried at 80 ° C. for 2 hours, and a charge transport layer was laminated thereon, to produce an optical sensor having a photoconductive layer having a thickness of 20 μm.

This optical sensor and the information recording medium produced in Example 1 were laminated with a 10 μm air gap provided therebetween with a polyimide film spacer 19 interposed therebetween.

In the information recording apparatus shown in FIG. 2 incorporating this laminate, a DC voltage of 850 V is applied for 0.05 seconds between the two layers of the optical sensor and the information recording medium, and at the same time, an imaging camera (RB67 manufactured by Mamiya) is applied. In), the gray scale was projected and exposed from the optical sensor side for 1/30 sec. After the exposure, the information recording medium was taken out. When the information recording medium was observed with the transmitted light, the transmittance in the light transmitting portion was 90%, and a recording portion including the light transmitting portion corresponding to the gray scale was observed.

Next, the information recording medium is read by a film scanner (LS-3500, manufactured by Nikon Corporation) 51 to read the recorded information, and the information is read by a sublimation transfer printer (JV).
As a result of outputting information using SP-5500 (manufactured by Company C), a good printed matter corresponding to the gray scale was obtained.

[0106]

Example 5 An ITO film having a thickness of 500 ° was formed on a sufficiently cleaned glass substrate having a thickness of 1.1 mm by a sputtering method to obtain an electrode layer. On the electrode, the following structural formula

[0107]

Embedded image

3 parts by weight of a fluorenone azo pigment (manufactured by Nippon Kosaku Dye Co., Ltd.) and 1 part by weight of a polyester resin (manufactured by Toyobo Co., Ltd., Byron 200) were mixed in a ratio of 1,4-dioxane: cyclohexane = 1: 1. A 100 g solution having a solid content of 2% by weight in a solvent is sufficiently dispersed with a paint shaker to form a coating liquid, and the coating liquid is applied using a blade coater having a gap of 2 mil, and dried at 100 ° C. for 1 hour. Thus, a charge generation layer having a thickness of 0.3 μm was formed.

Next, on this charge generation layer, the following structural formula was used as a charge transport material.

[0110]

Embedded image

Using 25 parts by weight of para-dimethylstilbene, a polystyrene resin (HRM-
3) A coating liquid obtained by mixing 5 parts by weight, 102 parts by weight of 1,1,2-trichloroethane and 68 parts by weight of dichloromethane,
After coating with a blade coater, the coating was dried at 80 ° C. for 2 hours to laminate a charge transport layer, and a photoconductive layer composed of a charge generation layer and a charge transport layer having a thickness of 20 μm was provided.

On this photoconductive layer, a fluororesin Cytop (trade name; manufactured by Asahi Glass Co., Ltd., water absorption 0.01%, specific resistance 1 × 10 ¹⁸ Ω · cm) was coated with perfluoro (2-butyltetrahydrofuran). ), And a 4.5% solution thereof was applied using a spinner at 1500 rpm for 20 seconds.
After drying at ℃ for 1 hour, a transparent insulating layer having a thickness of 0.8 μm was formed.

Next, on this transparent insulating layer, a smectic liquid crystal S-6 (manufactured by Merck) 5 parts by weight nematic liquid crystal E-31LV (manufactured by Merck) 0.5 parts by weight UV curing Resin M-400 (manufactured by Toa Gosei Chemical Industry Co., Ltd.) 4.5 parts by weight Photopolymerization initiator Darocure 1173 (manufactured by Ciba Geigy) 0.25 parts by weight Dichroic dye M-403 (anthraquinone-based) (Manufactured by Mitsui Toatsu Chemical Co., Ltd.) 0.1 part by weight of surfactant Florad FC-430 (manufactured by Sumitomo 3M) 0.1 part by weight of xylene (manufactured by Junsei Chemical Co., Ltd., reagent (Special grade) to give a 50% by weight solution. This solution is applied with a spinner (10 seconds, 300 rpm), put in a vacuum dryer at 47 ° C., left for 3 minutes, evacuated for 2 minutes, and then Return to normal thickness and remove solvent Was. Then, 600mJ /
Irradiation with ultraviolet light having an energy of cm ² was performed to laminate an information recording layer having a thickness of 6 μm.

Next, an ITO film having a thickness of 500 Å was formed as an upper electrode on the information recording layer by sputtering.
A second information recording medium of the present invention was manufactured. The transmittance of this information recording medium at 800 nm light was 60%.

Further, in producing the above information recording layer,
When an information recording medium was produced in the same manner without adding a dichroic dye, the transmittance at 800 nm light was 64%, and it can be seen that the transmittance was high without the dichroic dye.

The information recording medium thus formed is
As shown in FIG. 4, a DC voltage of 600 V was applied with the photoconductive layer side electrode being positive and the information recording layer side electrode being negative. Under a voltage applied state, exposure was performed from the photoconductive layer side using a halogen lamp having an illuminance of 1000 lux as a light source for 0.1 second, and after the exposure was completed, the information recording medium was taken out.

After the information recording, the transmittance at 800 nm was 90%. On the other hand, with respect to the information recording medium to which the dichroic dye was not added, information recording was performed in the same manner, and the transmittance at 800 nm was similarly measured. As a result, the transmittance was 90%. Like,
It can be seen that the information recording medium of the present invention has a higher contrast than the medium without the addition of the dichroic dye.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross section of an information recording medium of the present invention, wherein (a) shows a first information recording medium and (b) shows a cross section of a second information recording medium.

FIG. 2 is a schematic view of an apparatus for recording information on a first information recording medium using an optical sensor.

FIG. 3 is a diagram for explaining a method of reproducing recorded information on first and second information recording media.

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

[Explanation of symbols]

1 is an optical sensor, 3 is an information recording medium, 11 is an information recording layer, 13 and 13 'are electrode layers, 14 is a photoconductive layer, 15 is a substrate, 18 is an information light, 19 is a spacer, 21 is a light source,
2 is a shutter having a driving mechanism, 23 is a pulse generator (power supply), 24 is a dark box, A is transmitted light, and B is scattered light.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/135 G02F 1/1334

Claims (5)

(57) [Claims] 1. An electrode layer comprising a liquid crystal phase and an ultraviolet-curable resin phase, and an outer surface layer of which comprises only an ultraviolet-curable resin.
Formed in a skin layer made of
An information recording medium, which is provided with an information recording layer having a structure in which a liquid crystal phase is communicated therebetween, wherein a dichroic dye is contained in the liquid crystal phase. 2. The information recording medium according to claim 1, wherein the dichroic dye has a λ _{max in} toluene of 300 nm to 500 nm. 3. An information recording medium in which an electrode layer, a photoconductive layer, an information recording layer, and an electrode layer are sequentially provided, wherein at least one electrode is transparent, and the information recording layer has a liquid crystal phase and an ultraviolet ray hardening layer.
And UV curing of its outer surface layer
It is formed on a skin layer consisting of mold resin only,
With a structure in which oil particles are filled and the liquid crystal phase communicates between them.
An information recording medium according to claim 1, wherein said liquid crystal phase contains a dichroic dye. 4. The information recording medium according to claim 3, wherein the dichroic dye has a λ _{max in} toluene of 600 nm to 900 nm. 5. A dichroic dye in an amount of 0.01 to 5% by weight.
The information recording medium according to claim 1 or 3, wherein the information recording medium is contained.