JP3157306B2 - Electrostatic information recording medium and electrostatic information recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic information recording medium capable of recording information electrostatically by an exposure method at the time of applying a voltage and reproducing the information at an arbitrary time, and particularly has an excellent charge retention property. The present invention relates to an electrostatic information recording medium excellent in disturbance resistance and a method for recording the electrostatic information.

[0002]

2. Description of the Related Art A photoreceptor in which an electrode layer and a photoconductive layer are sequentially laminated on a support, and an electrostatic information recording medium in which an electrode layer and a charge holding layer are sequentially laminated on the support are opposed to each other. An image is recorded on the charge holding layer as an electrostatic latent image by applying an image while applying a voltage between the electrodes, and reproducing the electrostatic latent image is described in JP-A-1-290366. I have.

According to this method, extremely high-resolution analog recording is possible, and an electrostatic latent image recorded on an electrostatic information recording medium is held semipermanently. The recorded surface charges tend to gradually attenuate due to moisture in the air, and there is a problem that an electrostatic latent image is destroyed by external damage or contact.

For this reason, Japanese Patent Application Laid-Open No. 1-290366 discloses an electrostatic information recording medium in which an electrostatic latent image is formed on a charge holding layer and a protective layer is laminated on the surface to protect the electrostatic latent image. Further, as another electrostatic information recording medium, the charge retention layer is formed by patterning and laminating a photoconductive layer or a conductive layer on an insulating layer in pixel units, and furthermore, a thin insulating layer is formed on the pattern layer. By having a structure in which a conductive resin layer is laminated, the electrostatic latent image formed on the surface of the charge holding layer is passed through a thin insulating resin layer by a tunneling phenomenon and accumulated in the photoconductive layer or the conductive layer, An electrostatic information recording medium for holding an electrostatic latent image inside an electrostatic information recording medium is disclosed in
No. 5473. Each of these media has the advantage that the electrostatic latent image can be prevented from attenuating due to moisture in the air or physical contact with the information recording surface.

[0005] However, these methods have a problem that the process of manufacturing an electrostatic information recording medium and the operation of storing an electrostatic latent image after information recording are complicated. There is also a problem that the resolution is limited by the size of the formed pixel.

Therefore, the present inventors have made an electrostatic information recording medium in which the charge holding layer is a laminate of a resin layer having a low glass transition temperature and a heat-resistant insulating layer, and after recording an electrostatic latent image on the surface of the charge holding layer. It has been found that by heating the charge holding layer to a temperature higher than the glass transition temperature of the resin layer having a low glass transition temperature, the electrostatic information can be of an internal holding type, and an application was previously filed (Japanese Patent Laid-Open No. 3-7943). However, the transition state of the glass transition temperature is not always clear depending on the resin, and even if the charge holding layer is heated to a temperature higher than the glass transition temperature of the resin layer having a low glass transition temperature, charge injection does not occur, and the electrostatic latent temperature does not increase. It was found that the image could not be internally retained.

[0007]

SUMMARY OF THE INVENTION Therefore, the present invention
It is an object of the present invention to provide an electrostatic information recording medium and an electrostatic information recording method that can more reliably hold an electrostatic information recording medium capable of internally holding an electrostatic latent image.

[0008]

According to a first aspect of the present invention, there is provided an electrostatic information recording medium having an electrode layer and a charge holding layer, wherein the charge holding layer is opened by trapping a charge obtained by measuring a thermal stimulation current. A laminate of a low-temperature fluororesin layer and a high-trap-opening temperature insulating layer, the difference between the trap-opening temperature of the low-trap-temperature fluororesin layer and the trap-opening temperature of the high-trap-opening temperature insulating layer; Is 20 ° C. or higher.

Further, the electrostatic information recording method of the present invention comprises an electrode layer and a charge holding layer, wherein the charge holding layer has a low charge opening temperature for a charge obtained by measuring a heat stimulation current, and a fluorine resin layer having a low opening temperature. An electrostatic information recording device comprising a laminate of insulating layers having a high temperature, wherein a difference between a trap opening temperature in the fluorine resin layer having a low trap opening temperature and a trap opening temperature in the insulating layer having a high trap opening temperature is 20 ° C. or more. First, after recording electrostatic information on the surface of the charge holding layer on the medium, the electrostatic information recording medium is heated at a temperature higher than or equal to the trap opening temperature in the fluorine resin layer having a low trap opening temperature and having a high trap opening temperature. It is characterized in that the insulating layer is heated to a temperature lower than the trap opening temperature.

Hereinafter, the electrostatic information recording medium of the present invention will be described. FIG. 1 is a cross-sectional view of an electrostatic information recording medium of the present invention. In the figure, reference numeral 10 denotes an electrostatic information recording medium, 11 denotes a charge holding layer, 11a denotes a resin layer having a low trap opening temperature, and 11b denotes a high trap opening temperature. An insulating layer, 13 is an electrode, and 15 is a support.

As shown in FIGS. 1A and 1B, the first aspect of the electrostatic information recording medium of the present invention is as follows. First, an insulating layer 11b having a high trap opening temperature is formed on an electrode 13, and a trap is formed thereon. It has a structure in which resin layers 11a having a low open temperature are laminated.

The resin forming the resin layer having a low trap opening temperature has a specific resistance of 10 ¹⁴ Ω · cm at that temperature or lower.
It is required that the resin has the above-mentioned insulating properties, and it is preferable to use a resin whose trap opening temperature is higher than a normal living temperature. The thermal stimulation current measurement is measured using the open circuit thermal stimulation current measurement device shown in FIG. In the thermal stimulus current measuring device, a charged sample (charge retaining layer) 11 is arranged on an electrode 13, an upper electrode 13 'is arranged on the charged sample at a certain distance, and an ammeter A is provided between both electrodes. The sample is heated at a constant heating rate (5 ° C
/ Min. ), The current value with respect to the temperature change is measured while heating. In the measurement, the potential change of the upper electrode caused by the surface potential of the charged sample is taken out in the form of a current change in an external circuit, and the polarity of the surface potential charged on the sample and the sign of the taken out current are usually The opposite is true.

As the resin having a low trap opening temperature and the insulating layer forming material having a high trap opening temperature which constitute the charge holding layer, resins having different trap opening temperatures are selected from the following resins and combined. be able to. The difference between the trap opening temperatures of the two resin layers may be 20 ° C. or more, preferably 50 ° C. or more.

[0014]

Examples of the fluorine resin layer having a low trap opening temperature include polytetrafluoroethylene, fluorinated ethylene propylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polyether ether ketone resin, and polyparaxylylene as described below. What is shown by a structural formula can be used.

[0016]

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(Note that the C type is not limited to the above structure, and it is preferable to use one in which one of the sites other than the main chain binding site in the benzene ring is substituted with chlorine. One is replaced with chlorine.) In addition, the following general formula (1)

[0018]

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(Where n is 1 or 2) a fluorine-containing thermoplastic resin having a molecular weight such that its intrinsic viscosity at 50 ° C. is at least 0.1, or , The following general formula (1)

[0020]

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And / or general formula (2)

[0022]

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(Where n is 1 or 2) a repeating unit (a) having a ring structure represented by the following general formula (3):-(CF ₂ -CFX)-
(However, X is F, Cl, -O-CF ₂ CF ₂ CF ₃ , -O-CF ₂ CF (CF ₃ ) O
CF ₂ CF ₂ SO ₃ F, -O-CF ₂ CF ₂ CF ₂ COOCH ₃ ), comprising at least 80% by weight of the repeating unit (a), at 50 ° C. A fluorine-containing thermoplastic resin having a molecular weight such that the intrinsic viscosity is at least 0.1 can be suitably used.

The repeating unit (a) has the general formula CF ₂ = CF-O
-(CF ₂ ) _n It is obtained by radically cyclopolymerizing perfluoroallyl vinyl ether or perfluorobutenyl vinyl ether represented by CF = CF ₂ (where n is 1 or 2). Those containing the repeating unit (a) and the repeating unit (b) are represented by the general formula CF ₂ = CF-O
-(CF ₂ ) _n CF = CF ₂ (where n is 1 or 2) and a general formula CF ₂ = CFX (where X is F, Cl, -O-CF ₂ CF ₂ CF ₃ , -O-CF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₃ F,
-O-CF ₂ CF ₂ CF ₂ COOCH ₃ ) is obtained by radical polymerization with a monomer represented by the formula: These resins are disclosed, for example, in JP-A-1-131215. Furthermore,

[0025]

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(Provided that the dioxonol component content represented by the number m of repeating units is 20 to 90 mol%), and the melt viscosity at a temperature 90 to 110 ° C. higher than the glass transition temperature is 10 ² to 10 ^4. A fluorine-containing thermoplastic resin having a Pa · sec can also be used.

Examples of the fluorine-containing thermoplastic resin include, for example, those manufactured by DuPont (trade name “Teflon” AF1600, containing about 65 mol% of dioxonol units, glass transition temperature of 1).
60 ° C., melt viscosity 2657 Pa · sec (250 ° C., 100
(measured by ASTM D3835 in sec- ¹ ), water absorption 0.01% or less], manufactured by the company [trade name "Teflon" AF2
400, containing about 85 mol% of dioxonol units, glass transition temperature 240 ° C., melt viscosity 540 Pa · sec (350
C., measured at 100 sec ^{-1 according} to ASTM D3835), and a water absorption of 0.01% or less].

The resin laminate in the charge retention layer may be laminated by combining different resins among the above-mentioned resins, and even if the same resin is used, the trap opening temperature differs due to, for example, a difference in molecular weight. Those can be used in combination.

As a method for forming the resin layer, a film-shaped resin may be laminated, or another resin is dissolved in an appropriate solvent on the film-shaped resin, and the resin is formed by coating, dipping, or the like. Alternatively, it may be formed by applying another resin on the applied resin layer.

In place of the resin layer having a high trap opening temperature, an inorganic material layer having a high trap opening temperature may be used. For example _{SiO 2, Al 2 O 3,} ZrO 2, TiO 2, As 2 O 3, B 2 O 3,
Bi ₂ O ₃ , CdS, CaO, CeO ₂ , Cr ₂ O ₃ , CoO, GeO ₂ , Hf
O ₂ , Fe ₂ O ₃ , La ₂ O ₃ , MgO, MnO ₂ , Nd ₂ O ₃ , Nb ₂ O ₅ , Pb
_{O, Sb 2 O 3, SeO} 2, Ta 2 O 5, WO 3, V 2 O 5, Y 2 O 5, Y 2 O 3,
BaTiO ₃ , Bi ₂ TiO ₅ , CaO-SrO, CaO-Y ₂ O ₃ , Cr-SiO ₂ , LiT
Inorganic oxides such as aO ₃ , PbTiO ₃ , PbZrO ₃ , ZrO ₂ -Co, ZrO ₂ -SiO ₂ , also AlN, BN, NbN, Si ₃ N ₄ , TaN, TiN, V
N, ZrN, SiC, TiC, WC, Al ₄ C _{3 and the} like. Particularly preferred is silicon dioxide, and these inorganic material layers are formed by glow discharge, vapor deposition, sputtering, or by forcibly oxidizing or nitriding a metal or semiconductor.

In the resin layer having a high trap opening temperature, photoconductive fine particles or conductive fine particles may be present for the purpose of improving the charge retention characteristics. As the photoconductive fine particle material, amorphous silicon, crystalline silicon, amorphous selenium, crystalline selenium,
Inorganic photoconductive materials such as cadmium sulfide and zinc oxide, and organic photoconductive materials such as polyvinyl carbazole, phthalocyanine, and azo pigments are used. Examples of the conductive material include Group IA (alkali metal), Group IB (copper group), Group IIA (alkaline earth metal), Group IIB (zinc group), Group IIIA (aluminum) of the periodic table. Tribe), IIIB
Group (rare earth), group IVB (titanium group), group VB (vanadium group), group VIB (chromium group), group VIIB (manganese group), group VIII (iron group, platinum group) IVA
Group (carbon group) includes carbon, silicon, germanium, tin,
Antimony and bismuth are used as the lead and the VA group (nitrogen group), and sulfur, selenium and tellurium are used as the fine group powder as the VIA group (oxygen group). Metals among the above-mentioned elemental elements can also be used in the form of metal ions, fine powdery alloys, organic metals, and complexes. Further, the above element simple substance can be used in the form of an oxide, a phosphate, a sulfate, or a halide. Particularly, carbon, gold, copper, aluminum and the like are preferably used.

These photoconductive and conductive materials are deposited on a heated resin layer by using a low-pressure vapor deposition apparatus at a pressure of 10 Torr to 10 ^-3 To
Aggregate when evaporated under low pressure of about rr, 10-0.1μ
It becomes a state of ultrafine particles having a diameter of about m and can be present inside the resin layer. When a layer is formed by coating a resin solution, one microparticle is added to the resin solution.
0 ^-4 dispersed in a range of 1 percent by weight and may form the layer.

The thickness of the insulating layer 11b having a high trap opening temperature shown in FIG. 1 is preferably set to 0.1 μm or more.
If it is less than μm, leakage occurs because charges having a polarity opposite to that of the stored information charges are injected due to a tunneling phenomenon or the like.

The resin layer 11 having a low trap opening temperature
The thickness of “a” is not particularly limited, but if it exceeds 100 μm, it becomes difficult to read the potential when reproducing information charges. Further, when resolution is required when reproducing the information charges, it is preferable that the resolution is small. If the film thickness is large, disturbance of lines of electric force occurs. However, if it is less than 0.1 μm, the influence of pinholes and the like becomes remarkable, and sufficient performance cannot be obtained.

The electrodes of the electrostatic information recording medium are not limited as long as the specific resistance is 10 ⁶ Ω · cm or less, and may be an organic conductive material such as an inorganic metal conductive film, an inorganic metal oxide conductive film, or a quaternary ammonium salt. Film. Such electrodes are deposited, sputtered, CVD, coated, plated,
It is formed by a method such as dipping or electrolytic polymerization.

The film thickness needs to be changed depending on the electrical characteristics of the material constituting the electrodes and the voltage applied during information recording.
It is about 3000 °, and is formed on the entire surface between the support and the charge holding layer or in accordance with the formation pattern of the charge holding layer. In the case where a film-like material having its own strength is used as the charge holding layer, an electrode material may be formed on the film by vapor deposition or the like as described above.

The electrostatic information recording medium of the present invention may have a support. Figure 1 with support
(B). The material and thickness of the support 15 are not particularly limited as long as the support 15 has a certain strength capable of supporting the electrostatic information recording medium in a strong manner. , Paper or glass,
Rigid bodies such as plastic sheets and metal plates (which can also serve as electrodes) can be used. If the electrostatic information recording medium takes the form of a flexible film, tape or disk, a flexible plastic film is used. , A rigid sheet if strength is required,
An inorganic material such as glass is used. This is not necessary when the charge holding layer is a film-like material having its own strength.

Further, the electrostatic information recording medium of the present invention may be required to have optical transparency when recording and reproducing information. When light transmittance is required, it is preferable to provide an antireflection effect by providing an antireflection film, adjusting the thickness of each of the electrode layer and the charge holding layer, or combining both. .

The electrostatic information recording medium can take various shapes depending on information to be recorded or a recording method. For example, an electrostatic camera (Japanese Patent Application No. 63-
No. 121591), it has a general film (for single frame or continuous frame) shape or a disk shape. When digital information or analog information is recorded by a laser or the like, a tape shape, a disk shape,
Or it becomes a card shape.

Next, an electrostatic information recording method will be described with reference to FIG. In the figure, 1 is a photoreceptor, 5 is a support, 7 is an electrode, 9 is a photoconductive layer, 10 is an electrostatic information recording medium, 11 is a charge holding layer, 13 is an electrode, 15 is a support, 17 is a power source,
8 is an information light.

In order to record information on the electrostatic information recording medium of the present invention, a photoconductor is used in which a photoconductive layer such as an a-selenium layer or an organic photoconductive layer is laminated on an electrode. First, as shown in FIG.
Indium oxide-tin oxide (ITO) having a thickness of 1000
O) The photoreceptor 1 formed by laminating the electrodes 7 and further laminating the photoconductive layer 9 of about 10 μm and the electrostatic information recording medium 10 of the present invention with the gap of about 10 μm facing each other. I do.

Next, as shown in FIG.
To apply a voltage between the electrodes 7 and 13. In a dark place, since the photoconductive layer 9 is a high-resistance material, no change occurs between the electrodes if the voltage applied to the gap is equal to or lower than the discharge starting voltage according to Paschen's law. Information light 1 from photoconductor 1 side
When the light 8 enters, the photoconductive layer 9 in the portion where the information light has entered exhibits conductivity, discharge occurs, and information charges corresponding to the information light are accumulated in the charge holding layer. Then, as shown in FIG. 3C, the power supply 17 is turned off, the electrostatic information recording medium 3 is separated from the photoreceptor 1 (FIG. 3D), and information charges are accumulated on the surface of the electrostatic information recording medium. You.

After recording the information charges as surface charges, the electrostatic information recording medium is heated to a temperature higher than the trap opening temperature of the resin layer having a lower trap opening temperature and lower than the trap opening temperature of the insulating layer having a higher trap opening temperature. By doing so, the surface charge can be moved to the interface with the insulating layer having a high trap opening temperature, whereby the electrostatic latent image can be held inside the insulator and stabilized.

Next, as a method for inputting information light in the electrostatic information recording method of the present invention, there are a method using a high-resolution electrostatic camera and a recording method using a laser. First, a high-resolution electrostatic camera consists of a photoreceptor and an electrostatic information recording medium, instead of a photographic film used in a normal camera, and forms a recording member, and charges an electrostatic latent image according to the amount of incident light. Formed on the holding layer, a mechanical shutter can be used, and an electric shutter can also be used.
Also, using a color filter that separates optical information into R, G, and B light components by a prism and extracts it as parallel light,
Color photography can be performed by forming one frame with three sets of the electrostatic information recording medium separated into R, G, and B, or by arranging R, G, and B images on one plane to make one frame with one set. it can.

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), a semiconductor laser (780 nm, 810 nm, etc.) can be used, and the photoconductor and the electrostatic information recording medium are planar, and the surfaces are in close contact with each other, or are opposed at a certain interval, Apply. In this case, the photoconductor electrode may be set to the same polarity as the carrier of the photoconductor. 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 images is performed by modulating the light intensity of the laser. Digital recording such as characters, codes, and line drawings is performed using laser light.
This is performed by N-OFF control. In the case where a halftone dot is formed in an image, a laser beam is applied to a dot generator O.
It is formed by performing N-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.

Although the case where electrostatic information is recorded using a photosensitive member has been described above, the method for recording electrostatic information on an electrostatic information recording medium according to the present invention may be replaced by, for example, an electrode needle head or an ion current. An electrostatic recording using a head or a recording method using an optical printer such as a laser printer may be used.

Next, a method of reproducing the recorded electrostatic information will be described. FIG. 4 is a diagram showing an example of a potential reading method in the electrostatic information reproducing method. The same numbers as those in FIG. 1 indicate the same contents. In the drawing, 10 is an electrostatic information recording medium, 21 is a potential reading section, 23 is a detection electrode, 25 is a guard electrode, 27 is a capacitor, and 29 is a voltmeter.

In order to reproduce information from the electrostatic information recording medium in which information charges are stored, first, when the potential reading section 21 is opposed to the surface of the charge storage layer, the detection electrode 23 is charged by the charges stored in the charge storage layer. The generated electric field acts to generate an induced charge on the detection electrode surface in the same amount as the charge on the electrostatic information recording medium. Since the capacitor 27 is charged with the same amount of charge having a polarity opposite to that of the induced charge, a potential difference occurs between the electrodes of the capacitor according to the accumulated charge. By reading this value with the voltmeter 29, the potential of the information charge is obtained. be able to. Then, by scanning the surface of the charge holding layer by the potential reading unit 21, an electrostatic latent image can be output as an electric signal. In addition, since the electric field (line of electric force) due to the electric charges in a wider range than the detection electrode facing portion of the electrostatic information recording medium acts on the detection electrode 23 alone to lower the resolution, the guard electrode 25 grounded around the detection electrode is connected to the detection electrode 23. It may be arranged. As a result, the lines of electric force are directed in a direction perpendicular to the surface, so that the lines of electric force act only on the portion facing the detection electrode 23, and the potential of the portion substantially equal to the detection electrode area is read. be able to. Since the accuracy and resolution of potential reading vary greatly depending on the shape and size of the detection electrode and the guard electrode, and the distance between the detection electrode and the guard electrode, it is necessary to design an optimal condition in accordance with the required performance.

FIG. 5 is a diagram showing a schematic configuration of an electrostatic information reproducing method. In the figure, reference numeral 31 denotes a potential reading device, 33 denotes an amplifier,
35 is a CRT and 37 is a printer. In the figure, a charge potential is detected by a potential reading device 31, the detected output is amplified by an amplifier 33, displayed on a CRT 35, and printed out by a printer 37. In this case, at any time, a portion to be read can be arbitrarily selected and output, and repetitive reproduction can be performed. In addition, optical reading can be performed using a material whose optical properties change due to an electric field, for example, an electro-optic crystal or the like. Further, since the electrostatic latent image is obtained as an electric signal, it can be used for recording on another recording medium as needed.

[0050]

The function of the electrostatic information recording medium of the present invention is as follows.
An electrode layer and a charge holding layer, wherein the charge holding layer is a laminate of a resin layer having a low trap opening temperature of charge obtained by thermal stimulation current measurement and an insulating layer having a high trap opening temperature. After recording the electrostatic information on the surface of the holding layer, the electrostatic information recording medium is heated to a temperature equal to or higher than the trap opening temperature of the resin layer having a low trap opening temperature and equal to or lower than the trap opening temperature of the insulating layer having a high trap opening temperature. As a result, it is found that information charges move in the resin layer having a low trap opening temperature, and that the information charges are stably held inside the electrostatic information recording medium by cooling the electrostatic information recording medium. It is a thing.

Although the detailed reason for the stabilization is unknown,
FIG. 6 schematically shows the electrostatic information recording medium shown in FIG. As shown in the figure, by heating after accumulating the electrostatic latent image on the surface, the information charge or the charge induced by the information charge probably causes the electric field to act in the conductive resin layer having a low trap opening temperature. The charges trapped in the insulating layer having a high trap opening temperature cannot be released by the heat energy by the above-mentioned heating, and the information charges are traps which have been insulated by cooling the electrostatic information recording medium. It is considered that the resin is stably held near the interface between the resin layer having a low opening temperature and the insulating layer having a high trap opening temperature.

In the electrostatic information recording medium of the present invention, the accumulated electrostatic information is very stable because the electrostatic information is stored inside the electrostatic information recording medium. It is possible to obtain an excellent electrostatic information recording medium having no charge decay due to disturbances such as the above. Hereinafter, examples will be described.

[0053]

Embodiment 1 Vacuum deposition (10 mm) was performed on a 1 mm thick glass substrate.
^-5 Torr) Al electrode is laminated to a thickness of 1000mm.
l Fluororesin (trade name; Cytop CTX-
807, manufactured by Asahi Glass Co., Ltd., glass transition temperature: 108 ° C.) in a fluorine-based solvent (trade name: Fluorinert FC-40, manufactured by 3M), and a spin coater (700 rpm, 700 rpm).
0 sec), air-dried at room temperature for 2 hours,
After drying in an oven at a temperature of 1 ° C. for 1 hour, a resin layer having a thickness of 2 μm was laminated after drying.

Then, on this resin layer, a fluororesin (trade name: Florard FC-722, manufactured by 3M, glass transition temperature: 30 ° C. to 40 ° C.) was coated with a fluorine-based solvent (trade name: Fluorinert FC-40, manufactured by 3M). Co., Ltd.) was applied by a spin coater (1000 rpm, 20 sec) and laminated, air-dried at room temperature for 2 hours, and dried in an oven at 80 ° C. for 2 hours. After drying, a resin layer having a thickness of 1.8 μm was formed. Were laminated to obtain an electrostatic information recording medium of the present invention shown in FIG. 1 (b).

The electrostatic information recording medium was charged to a surface potential of -340 V by corona charging. The charged electrostatic information recording medium is subjected to an open circuit thermal stimulation current measuring device shown in FIG. 3 (manufactured by Toyo Seiki Seisaku-sho, Ltd.).
And heated at a constant heating rate (5 ° C./min.), And the current value obtained with respect to the heating temperature was measured. FIG. 7 shows the result.

As can be seen from the figure, in the electrostatic information recording medium of the present invention, current peaks occurred at around 100 ° C. and 140 ° C., and the residual potential after the measurement became 0V. In addition, it was found that the current peak value in Comparative Example 1 described later and the current peak value in Comparative Example 2 were combined.

Next, the electrostatic information recording medium obtained above was charged by corona charging so as to have a surface potential of -455 V in the same manner as described above, and the peak at 100 ° C. was similarly measured by an open circuit thermal stimulation current measuring device. The electrostatic information recording medium was taken out at a stage before 140 ° C. and rapidly cooled. For the electrostatic information recording medium after cooling,
The measured residual potential was -280 V.

A polyethylene terephthalate film on which aluminum was deposited on the back surface was brought into close contact with the surface of the electrostatic information recording medium under a pressure of 100 kgf / cm ² , then peeled off, and the electrostatic latent image recorded on the electrostatic information recording medium was peeled off. The image was examined for contact resistance. Even after performing the contact peeling operation five times, -28
It was confirmed that the residual potential of 0 V was maintained, and the surface charge was stably held inside the electrostatic information recording medium.

The electrostatic information recording medium charged by corona charging so as to have a surface potential of -455 V in the same manner as described above was heated to 50 to 80 ° C., cooled, and the residual potential was measured. And, as described above, 5
After performing the contact peeling operation twice, the potential became -337 V, the surface charge was not held inside the electrostatic information recording medium, and the effect of the present invention was not exhibited.

[0060]

[Comparative Example 1] Vacuum deposition (10
^-5 Torr) Al electrode is laminated to a thickness of 1000mm.
l Fluororesin (trade name; Cytop CTX-
807, manufactured by Asahi Glass Co., Ltd., glass transition temperature: 108 ° C.) was applied by a spin coater (700 rpm, 20 sec) to a 7% solution of the fluorine-based solvent used in Example 1, air-dried at room temperature for 2 hours, and then oven at 180 ° C. For 1 hour, and after drying, a resin layer having a thickness of 2 μm was laminated.

The electrostatic information recording medium was charged to a surface potential of -235 V by corona charging. The charged electrostatic information recording medium was measured for the current value obtained with respect to the heating temperature by using an open circuit thermal stimulation current measuring device in the same manner as described above. FIG. 8 shows the result.

As can be seen from the figure, in this electrostatic information recording medium, a current peak was generated at around 140 ° C. due to charge detrapping, and the residual potential of the medium after measurement was 0 V.

After the surface of the electrostatic information recording medium was charged to a surface potential of -200 V by corona charging in the same manner as described above, and the contact peeling operation was performed five times in the same manner as above, the residual potential of -150 V was obtained. And the surface charge was attenuated by the contact peeling operation.

[0064]

Comparative Example 2 Vacuum evaporation (10 mm) was performed on a glass substrate having a thickness of 1 mm.
^-5 Torr) Al electrode is laminated to a thickness of 1000mm.
l Fluororesin (trade name: Florard FC-7) on the electrode
22, 3M, glass transition temperature 30 ° C. to 40 ° C.) was applied to a fluorine-based solvent used in Example 1 and coated with an 8% solution by a spin coater (1000 rpm, 20 sec) and laminated, and then room temperature for 2 hours. After air drying, drying was performed in an oven at 80 ° C. for 2 hours, and a resin layer having a thickness of 1.8 μm was laminated after drying.

The electrostatic information recording medium was charged to a surface potential of -170 V by corona charging. The charged electrostatic information recording medium was measured for the current value obtained with respect to the heating temperature by using an open circuit thermal stimulation current measuring device in the same manner as described above. FIG. 9 shows the result.

As can be seen from the figure, in this electrostatic information recording medium, a current peak was generated at around 100 ° C. due to charge detrapping, and the residual potential of the medium after measurement was 0 V. After the surface of the electrostatic information recording medium was charged to a surface potential of −105 V by corona charging as described above, the contact peeling operation was performed five times as described above.
The residual potential was -90 V, and the surface charge was reduced by the contact peeling operation.

[0067]

Embodiment 2 (Preparation of Photoreceptor) As a charge generating material, it is represented by the following formula:

[0068]

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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 dichloromethane: 1,1 , 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.

(Electrostatic Information Recording Method) The photosensitive member produced above and the electrostatic information recording medium produced in Example 1 were exposed at the time of voltage application by the electrostatic information recording method shown in FIG.
After obtaining a charge image of −200 V in a pattern of 0 μm, 1
Heated at 20 ° C. for 60 seconds. The residual potential after heating was measured to be -120V.

On the other hand, for comparison, electrostatic information was recorded on the electrostatic information recording medium manufactured in Comparative Example 1 in the same manner as described above, and a charge image of -120 V was obtained.

When the electrostatic information recording medium of the present invention and the comparative medium were subjected to five contact-peeling operations in the same manner as in Example 1, the electrostatic information recording medium of the present invention was different from that before the contact peeling. Although the potential of -120 V was maintained, the residual potential of the electrostatic information recording medium manufactured in Comparative Example 1 was -90 V, and the surface charge was attenuated by the contact peeling operation.

[Brief description of the drawings]

FIGS. 1A and 1B are cross-sectional views of an electrostatic information recording medium according to the present invention.

FIG. 2 is a schematic diagram of a thermal stimulation current measuring device.

FIG. 3 is a diagram for explaining the electrostatic information recording method of the present invention.

FIG. 4 is a diagram illustrating an example of a DC amplification type potential reading method.

FIG. 5 is a diagram showing a schematic configuration of an electrostatic information recording / reproducing method.

FIG. 6 is a schematic diagram illustrating stabilization of electrostatic information in the electrostatic information recording medium of the present invention.

FIG. 7 is a diagram showing a result of measuring a heat stimulus current in the electrostatic information recording medium manufactured in Example 1.

FIG. 8 is a diagram showing a measurement result of a heat stimulus current in the electrostatic information recording medium manufactured in Comparative Example 1.

FIG. 9 is a diagram showing a result of measuring a heat stimulus current in the electrostatic information recording medium manufactured in Comparative Example 2.

[Explanation of symbols]

1 is a photoreceptor, 5 is a support, 7 is an electrode, 9 is a photoconductive layer, 1
0 denotes an electrostatic information recording medium, 11 denotes a charge holding layer, 11a denotes a resin layer having a low trap opening temperature, 11b denotes an insulating layer having a high trap opening temperature, 13 denotes an electrode, 15 denotes a support, 17 denotes a power source, and 18 denotes information. Light, 21 is a potential reading unit, 23 is a detection electrode, 25 is a guard electrode, 27 is a capacitor, 31 is a potential reading device, 33 is an amplifier, 35 is a CRT, and 37 is a printer.

Claims (2)

(57) [Claims] 1. A electrode layer and the electrostatic information recording medium having a charge retaining layer, charge retaining layer having high thermally stimulated current low fluorine resin layer and the trap opening temperature of the trap opening temperature of the charge obtained by measuring insulation Ri Do from the stack of layers,
The trap in the fluorine resin layer having a low trap opening temperature is trapped.
Temperature and the insulating layer where the trap opening temperature is high.
Electrostatic information recording medium in which the difference between the kicking trap opening temperature is characterized in der Rukoto 20 ° C. or higher. 2. An electrode layer and a charge holding layer, wherein the charge holding layer is a laminate of a fluorine resin layer having a low charge trap opening temperature and an insulating layer having a high trap opening temperature obtained by thermal stimulation current measurement. Lowering the trap opening temperature
The trap opening temperature in the fluorine resin layer and the trap opening temperature.
Difference of trap opening temperature in insulating layer with high trap opening temperature
To but Ru der 20 ° C. or more electrostatic information recording medium, firstly, after recording an electrostatic information on the charge holding layer surface, the trap opening temperature of the electrostatic information recording medium at a low fluorine resin layer of the trap opening temperature As described above, an electrostatic information recording method is characterized in that the insulating layer having a high trap opening temperature is heated to a temperature equal to or lower than the trap opening temperature.