JPH037942A - Charge holding medium - Google Patents

Abstract

PURPOSE:To permanently maintain the information charges accumulated in a charge holding layer by forming the charge holding layer of a resin contg. fluorine. CONSTITUTION:The charge holding medium is provided with at least an electrode layer 13 and the charge holding layer 11. The layer 11 is formed of the resin (A) contg. the fluorine. A tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, polytetrafluoroethylene, etc., are preferably used for the resin A. The medium 3 can be formed by depositing the Al electrode 13 by evaporation on the film 11 of the resin A. Also, formation of the medium by depositing the Al electrode 13 on a glass supporting body 15 by evaporation and applying the soln. of the resin A thereon is possible as well.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a charge-retaining medium that can electrostatically record information using an exposure method when voltage is applied, etc., and that can reproduce information at any time. The present invention relates to a charge retention medium with excellent charge retention properties.

[Conventional technology]

Conventionally, in electrophotography, etc., a photoconductive layer is deposited on an electrode layer, the entire surface of the photoconductive layer is charged, and then imagewise exposed to leak the charge in the exposed area, thereby forming an electrostatic latent layer on the photoconductive layer. It is known that an image is formed optically, a toner having a polarity opposite to the residual charge is attached, and the image is electrostatically transferred onto paper or the like to be developed. This is mainly used for copying, but it shortens the retention period of electrostatic charge in the photoconductive layer as a recording medium, and the toner is developed immediately after the electrostatic latent image is formed. This makes it very unusable due to its low sensitivity.

Furthermore, the TV photography technique requires line-sequential scanning in order to extract and record the electrical image signals obtained by the image pickup tube. Line-sequential scanning is performed using an electron beam in the image pickup tube and a magnetic head for video recording, but because resolution depends on the number of scanning lines, it is said to be significantly worse than planar analog recording such as silver halide photography. There's a problem.

Furthermore, TV imaging systems that use solid-state imaging devices, which have been developing in recent years, are essentially the same in terms of resolution, and the problems inherent in these technologies become worse the higher the quality and resolution of image recording. The processing process is complicated, and if the process is simple, there is a lack of storage function or a basic deterioration of image quality.

[Problem to be solved by the invention]

The present inventors first placed a photoreceptor made of a photoconductive layer with an electrode on the front surface and a charge retention medium made of a charge retention layer with an electrode on the rear surface facing each other, and then After image exposure with a voltage applied, the charge retention medium is separated,
They discovered that information could be reproduced extremely clearly by amplifying the surface potential accumulated as image information on the surface of the charge retention layer and outputting the image reproduction, and filed an application for the charge retention medium (Japanese Patent Application No. 127555/1983).

The present invention aims at further improving charge retention characteristics, and an object of the present invention is to provide a charge retention medium having excellent charge retention characteristics.

[Means to solve the problem]

For this purpose, the charge retention medium of the present invention is characterized in that the charge retention medium has at least an electrode layer and a charge retention layer, and the charge retention layer is made of a resin containing fluorine.

Hereinafter, the constituent materials of the charge retention medium of the present invention, the method for forming the same, and the electrostatic image recording and reproducing method using this charge retention medium will be explained.

FIG. 1 is a cross-sectional view showing an example of each aspect of the charge retention medium 3 of the present invention, in which 3 is the charge retention medium, 11 is the charge retention layer, 13 is the charge retention medium electrode, 15 is the support, 16 is an adhesive layer.

The charge retention layer 11 is made of a fluorine-containing resin having high insulation properties.

Examples of resins containing fluorine include poly (tetrafluoroethylene) (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PF
A), Tetrafluoroethylene-hexafluoropropylene copolymer (FEP), Tetrafluoroethylene-hexafluoropropylene-berfluoroalkyl vinyl ether copolymer (EPE), Tetrafluoroethylene-ethylene copolymer (ETFE), Poly( In addition to fluororesins such as chlorotrifluoroethylene (PCTFE) and chlorotrifluoroethylene-ethylene copolymer (ECTFE), thermoplastic resins, thermosetting resins, ultraviolet curable resins, electron beam curable resins, etc. It can be used in combination with a resin in which part or all of hydrogen has been replaced with fluorine atoms, such as an energy ray-curable resin or an engineering plastic, or a resin containing fluorine.

In addition, it is composed of a repeating unit of a ring structure represented by - binding margin and/or - binding margin (where n is 1 or 2), and has a molecular weight such that the intrinsic viscosity at 50°C is at least 0.1. A fluorine-containing thermoplastic resin having a repeating unit (a) of a ring structure represented by - binding allowance and/or - binding allowance (however, n is 1 or 2), and binding allowance,
...(3)-(CF2-C
PX) - (However, X1tF, CI, -0-C11, CF, CF,
, -0-CF@CP(CF,)mouthCFffiCFffS
O31', -0-CF, CF, CF2C0mouth CH,
), containing at least 80% by weight of the repeating unit (a), and having a molecular weight such that the intrinsic viscosity at 50° C. is at least 0.1. can be suitably used.

The repeating unit (a) is obtained by radical cyclization polymerization of perfluoroallyl vinyl ether or perfluorobutenyl vinyl ether represented by the formula % (where n is 1 or 2). be. In addition, those containing the repeating unit (a) and the above-mentioned repeating unit (b) are perfluorovinyl ethers represented by the formula % (where n is 1 or 2) and the general formula %)). It can be obtained by radical polymerization with 1,000 yen. These resins are disclosed in, for example, JP-A-1-
It is disclosed in Japanese Patent No. 131215.

In the case of the charge-retaining medium shown in FIG. 1(a), the charge-retaining layer is first formed on the electrode by vapor deposition, sputtering, etc., or by dissolving it in a solvent and coating or dipping. can do. Further, a layer may be formed by adhering a fluorine-containing polymer film to an electrode via an adhesive or the like, or an electrode forming material may be laminated on the fluorine-containing polymer film by a method such as vapor deposition. The above-mentioned cyclized polymer consisting of the repeating unit (a) shown in the above-mentioned binding margin (1) and/or (2), or the copolymer consisting of the repeating unit (a) and the repeating unit (b) is used. In such cases, it is preferable to dissolve it in a fluorine-based solvent such as perfluoro(2-butyltetrahydrofuran) and apply it.

The thickness of the charge retention layer should be between 0.1 μm and 100 μm. If it is less than 0.1 μm, charge leakage will occur even if the charge is retained, and if it is 100 μm or more, flexibility is required. Loses flexibility.

Furthermore, photoconductive and conductive fine particles may be present in these fluorine-containing resins for charge accumulation.

As photoconductive fine particle materials, inorganic photoconductive materials such as amorphous silicon, crystalline silicon, amorphous selenium, crystalline selenium, cadmium sulfide, and zinc oxide, and organic photoconductive materials such as polyvinyl carbazole, phthalocyanine, and azo pigments are used. be done.

Conductive materials include Group 1A (alkali metals), Group IB (copper), Group 2A (alkaline earth metals), Group 2B (zinc group), and Group 3A (aluminum group) of the periodic table. ), Group 3B (rare earths), Group IVB (titanium), Group VB (vanadium), Group VIB (chromium), Group ■B (manganese), Group ■ (iron, platinum). Also, the IVA group (carbon group) includes carbon, silicon, germanium, tin, and lead, and the VA group (nitrogen group) includes antimony,
Bismuth and VTA group (oxygen group) sulfur, selenium, and tellurium are used in fine powder form. Among the above elements, metals include metal ions, fine particle alloys, organic metals,
It can also be used in the form of a complex. Furthermore, the above elements can be used in the form of oxides, phosphorus oxides, sulfides, and halides. In particular, carbon, gold, copper, aluminum, etc. are preferably used.

This fine particle layer is formed by vapor depositing its forming material onto the electrode or the fluororesin layer using a low pressure vapor deposition apparatus. The particle layer forming material is 10 TOrr to 10-'T
When evaporated under a low pressure of about 10 to 0.
The particles are in the form of ultrafine particles with a diameter of about 1 μm, and the particles are stacked on the electric bridge or the surface of the fluororesin layer in a single layer or in a plurality of layers. In addition, when forming the charge retention layer by coating, it can be formed by dispersing particulate material in a fluororesin solution and coating it.

The charge retention medium 3 records information in the charge retention layer 11 as a distribution of static charges. Information recorded accordingly;
Alternatively, the shape of this charge retention medium can take various shapes depending on the recording method. For example, when used in an electrostatic camera (Japanese Patent Application No. 63-121591 filed by the same applicant), it is in the form of a general film (single frame or continuous frame) or a disk, and digital information or analog When recording information, it takes the form of a tape, disk, or card.

The support 15 in the charge retention medium shown in FIG. 1(b) supports the charge retention medium 3 with strength, and if it has a certain level of strength that can support the charge retention layer, There are no particular restrictions on the material and thickness; for example, flexible plastic films, metal foils, paper, or rigid bodies such as glass, plastic sheets, and metal plates (which can also serve as electrodes) may be used, and light transmittance may also be used. The same may be required. When light transmittance is required, antireflection properties can be imparted by using a layer having an antireflection effect, adjusting the film thickness to a level that can exhibit the antireflection effect, or combining both, if necessary. Specifically, when the charge retention medium 3 takes the form of a flexible film, tape, or disk, a flexible plastic film is used as the support, and when strength is required, a rigid sheet, Inorganic materials such as glass are used.

A case where the charge retention medium 3 takes the shape of a flexible film, tape, or disk will be described.

First, what is shown in FIG. 2(a) is a type in which the charge retention layer 11, which is a recording section, is continuous.

This is made by forming a charge retention layer on a support such as a plastic film provided with an electrode layer, leaving both sides of the support or the entire surface of the support. This charge retention medium has a length that is at least twice as long as one screen to be recorded (for example, one frame in the case of camera recording, or the track width in digital information recording). Of course, it also includes a structure in which a plurality of charge-retaining media are joined in the longitudinal direction, and in this case, there may be a slit zone between adjacent charge-retaining layers, where the charge-retaining layer is missing.

Furthermore, as shown in FIG. 2(b), there is a type in which the charge retention N11 is discontinuous in the longitudinal direction.

This is made by forming a charge retention layer discontinuously in the longitudinal direction on a support such as a plastic film, with or without leaving both sides of the support. It is formed to a size that corresponds to the charge retention layer. The size of this charge retention layer depends on the exposure method of the image and information input device, but for example, when using a camera, 35 m
m x 35 mm, which is the track width of digital information recording in the case of spot input such as a laser beam.

In the case of digital information recording, a charge retention layer missing portion formed between adjacent charge retention layers is used as a tracking band when inputting and outputting information. Of course, it also includes a structure in which a plurality of charge-retaining media are joined in the longitudinal direction, and in this case, there may be a slit zone between adjacent charge-retaining layers, where the charge-retaining layer is missing.

Furthermore, as shown in FIG. 2(c), there is a type in which the charge retention layer is discontinuous in the width direction.

This type is made by forming a charge retention layer discontinuously in the width direction on a support such as a plastic film provided with an electrode layer, with or without leaving both sides of the support. A plurality of band-shaped charge retention layers are formed on the body. The width of this charge retention layer is equal to or an integral multiple of the track width of digital information to be recorded, and the charge retention layer missing portion formed between adjacent charge retention layers is
It is used as a tracking band when inputting and outputting information.

Furthermore, as shown in FIG. 2(d), there is a disc-shaped type.

In this type, a charge retention layer is formed on the entire surface of a support such as a circular plastic film provided with an electrode layer, or with a continuous spiral missing portion of the charge retention layer. This charge retention medium may have a circular cutout for driving an input/output device. Further, in the case of a digital information recording section, the continuous spiral missing portion of the charge retention layer can be used as a tracking band when inputting and outputting information.

The electrode 13 is formed on the support via an adhesive layer 16 or by a vapor deposition method, and the material thereof has a specific resistance value of 106.
There is no limitation as long as it is 0.CII+ or less, and examples include inorganic metal conductive films, inorganic metal oxide conductive films, and organic conductive films such as quaternary ammonium salts. Such charge retention medium electrodes are formed on the support by methods such as vapor deposition, sputtering, CVD, coating, plating, dipping, and electrolytic polymerization.

In addition, the film thickness needs to be changed depending on the electrical properties of the material constituting the electrode and the applied voltage during information recording, but for example, in the case of aluminum, it is about 100 to 3000, and the thickness of the support and charge retention layer is approximately 100 to 3000. It is formed on the entire surface between or in accordance with the formation pattern of the charge retention layer.

When light transmittance is required, antireflection properties can be imparted by using a layer having an antireflection effect, adjusting the film thickness to a level that can exhibit the antireflection effect, or combining both, if necessary.

The charge-retaining medium of the present invention also includes a plastic film as a protective film on the surface of the charge-retaining medium to prevent damage to the surface of the charge-retaining medium and attenuation of information charges after information is recorded.
Alternatively, the film may be coated with a plastic solution or formed to a thickness of several hundred to several tens of micrometers by a vapor deposition method, and information reproduction is possible at this level.

As a protective film, first, recycled rubber, styrene-butadiene rubber, polyisoprene, butyl rubber, Buna-N (butadiene-acrylonitrile rubber), polyvinyl ether (ethyl group or higher (having a hydrocarbon group as an alcohol residue), polyacrylate ester (having an ethyl group or higher hydrocarbon group), silicone rubber, polyterpene resin, gum rosin, rosin ester, and rosin derivatives, oil-soluble phenol Formed by forming a film with a thickness of 0.5 to several tens of micrometers from one or more of resin, coumaron/indene resin, and petroleum-based hydrocarbon resin and attaching it to the surface of a charge retention medium. Alternatively, the above-mentioned plastic film as a charge retention layer forming material may be attached using a removable adhesive, and the adhesive has a specific resistance of 10'4 Ω・C.
m or more silicone oil, dimethyl silicone oil, methylphenyl silicone oil, higher fatty acid modified silicone oil, methyl chlorinated phenyl silicone oil, alkyl modified silicone oil, methylhydrogen silicone oil, cyclic polydimethylsiloxane, silicone polyether copolymer , amino-modified silicone oil, epoxy-modified silicone oil, insulating oil, etc., or a mixture of two or more thereof may be used.

Further, the above-mentioned fluororesin or the like may be formed by a vapor deposition method, a spinner coating method, or the like so as to have a film thickness of several hundred to several tens of μm.

Further, when it is necessary to impart photosensitivity to the charge retention medium at the same time, the charge retention layer can be provided on the surface of the photoreceptor having the photoconductive layer by coating or adhesion.

Next, an electrostatic image recording method, which is one method of using the charge retention medium of the present invention, will be described.

FIG. 3 is a diagram for explaining the electrostatic image recording method, in which 1 is a photoreceptor, 5 is a photoconductive layer support, 7 is a photoreceptor electrode, and 9 is a diagram for explaining an electrostatic image recording method.
1 is a photoconductive layer, and 17 is a power source.

First 1! A transparent photoconductor electrode 7 made of IT○ with a thickness of 1000 is formed on a photoconductive layer support 5 made of glass with a thickness of I11, and a photoconductive layer 9 of about 10 μm is formed on this to form a photoconductor 1. It consists of As shown in FIG. 2A, a charge holding medium 3 is placed with respect to the photoreceptor 1 with a gap of about 10 μm in between.

Next, as shown in FIG. 7(b), the electrode 7.
A voltage is applied between 13. In the dark, the photoconductive layer 9 is a high-resistance material, so if the voltage applied to the gap is equal to or lower than the discharge start voltage according to Paschen's law, no change occurs between the electrodes. Further, when a voltage equal to or higher than the discharge starting voltage is applied to the gap by an external power source, a discharge occurs, charge is accumulated on the surface of the charge holding medium, and this state continues until the voltage drops to the discharge starting voltage, resulting in fogging charge. Light 18 from the photoreceptor 1 side
When the photoconductive layer 9 is incident, the portion of the photoconductive layer 9 on which the light is incident exhibits conductivity, a discharge occurs, and charges are accumulated on the surface of the charge retention medium. Further, even if there is a uniform fog charge in advance, charge is further accumulated in the portion where light is incident. Next, power supply 17
The formation of the electrostatic latent image is completed by turning OFF and peeling off the charge holding medium 3 from the photoreceptor 1.

When this electrostatic image recording method is used for planar analog recording,
Similar to silver salt photography, high resolution can be obtained, and the information charges are protected in the charge retention layer and can be stored for a long time without discharging.

Methods for inputting information to the charge retention medium of the present invention include a method using a high-resolution electrostatic camera and a recording method using a laser. First of all, a high-resolution electrostatic camera uses a photoconductor 1 consisting of a photoconductive layer 9 with a photoconductor electrode 7 on the front surface, and a charge on the rear surface facing the photoconductor 1, instead of the photographic film used in ordinary cameras. A recording member is constituted by a charge retention medium consisting of a charge retention layer 11 provided with a retention medium electrode 13,
An electrostatic latent image of the incident optical image is formed in the fine particles by applying a voltage to the picture electrode, making the photoconductive layer conductive according to the amount of incident light, and accumulating charges on the charge retention layer according to the amount of incident light. A mechanical shutter can be used, or an electric shutter can be used, and the electrostatic latent image can be retained for a long time regardless of whether it is in a bright or dark place. In addition, a prism separates the optical information into R, G, and B light components, and a color filter is used to extract them as parallel light, and three sets of charge retention media separated into RSG and B are used to form one frame, or on one plane. It is also possible to take color photographs by arranging the RlG and B images so that one set constitutes one frame.

For recording methods using lasers, the light sources include argon laser (514,488 nm), helium-neon laser (633 nm), and semiconductor laser (78 nm).
0 nm, 810 nm, etc.), and a voltage is applied to the photoreceptor and the charge holding medium with their surfaces brought into close contact with each other or facing each other with a fixed interval. In this case, it is preferable to set the photoreceptor electrode to the same polarity as the carrier of the photoreceptor. In this state, laser exposure corresponding to image signals, character signals, code signals, and line drawing signals is performed by scanning. Analog recording such as images is performed by modulating the light intensity of the laser, and digital recording such as characters, codes, and line drawings is performed by ON-OFF control of the laser light. Also, in images where halftone dots are formed,
It is formed by applying dot generator ON-OFF control to laser light. Note that the spectral characteristics of the photoconductive layer in the photoreceptor do not need to be highly bank chromatic, but only need to be sensitive to the wavelength of the laser light source.

Next, a method for reproducing electrostatic information recorded on the charge retention medium will be explained.

FIG. 4 is a diagram showing an example of a potential reading method in an electrostatic information recording and reproducing method, and the same numbers as in FIG. 1 indicate the same contents. In the figure, 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.

To reproduce information from a charge-holding medium that has accumulated information charges, first, the potential reading unit 21 is placed opposite the surface of the charge-holding medium, and an electric field generated by the charges accumulated in the fine particle layer acts on the detection electrode 23. An induced charge equal to the charge on the charge storage medium is generated on the electrode surface. Since the capacitor 27 is charged with an equal amount of charge of opposite polarity to this induced charge, a potential difference corresponding to the accumulated charge is generated between the electrodes of the capacitor, and by reading this value with a voltmeter 29, the potential of the information charge is determined. be able to. Then, the potential reading section 21
The electrostatic latent image can be output as an electric signal by scanning the surface of the charge holding medium with the . Note that the detection electrode 2
If only the guard electrode 25 is grounded around the detection electrode, the electric field (electric line of force) due to the charges in a wider range than the area facing the detection electrode of the charge retention medium will act and the resolution will deteriorate.
You may also place . As a result, the lines of electric force are oriented perpendicularly to the surface, so that the lines of electric force only act on the area facing the detection electrode 23, and the potential of the area approximately equal to the area of the detection electrode 23 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 guard electrode, and the distance between them and the charge retention medium, it is necessary to find and design optimal conditions according to the required performance.

FIG. 5 is a diagram showing a schematic configuration of an electrostatic image reproduction method, in which 31 is a potential reading device, 33 is an amplifier, and 35 is a CR
T, 37 is a printer.

In the figure, a potential reading device 31 detects the charge potential, and an amplifier 33 amplifies the detected output, which can be displayed on a CRT 35 and printed out using a printer 37. In this case, it is possible to arbitrarily select and output the part to be read at any time, and it is also possible to reproduce it repeatedly.

It is also possible to read optically using a material whose optical properties change depending on an electric field, such as an electro-optic crystal. Furthermore, since the electrostatic latent image is obtained as an electric signal, it can also be used for recording on other recording media, etc., if necessary.

[Effect]

The charge retention layer 11 in the charge retention medium needs to be formed from a highly insulating polymeric material in order to suppress the movement of charges, and is required to have insulation properties. It has been discovered that this material has extremely excellent charge retention performance.

In addition, as a charge retention medium, heat resistance is required as a physical property of the polymer material that forms the charge retention layer, and fluororesins have high heat resistance, and charge retention media are generally not affected by humidity. It is necessary to prevent the leakage of information charges due to oxidation, and for this purpose it is necessary that the polymer material forming the charge retention layer has a low water absorption rate, but fluorine-containing resin has an extremely low water absorption rate. By using a fluorine-containing resin as the charge retention layer, a charge retention medium with extremely high charge retention performance can be obtained.

The charge retention medium can be used as an electrostatic recording medium using an electrode needle head or an ion flow head, an optical printer such as a laser printer, or a recording medium using an electron beam, ion implantation, etc. It is suitable as an electrostatic information recording medium using

The charge retention medium of the present invention has good charge retention performance, and the accumulated information charge is stored inside the charge retention layer, so it is extremely stable. When reproducing information, it is possible to reproduce information by measuring the potential difference between the electrode and the surface potential. The potential difference can be easily detected and easily reproduced as high-quality, high-resolution information.

Examples will be described below.

[Example 1] Specific resistance 1018Ω・Cm or more, water absorption rate 0.01%,! A 12.5 μm thick tetrafluoroethylene-hexafluoropropylene copolymer (FEP) film (manufactured by DuPont) was laminated with an Al electrode to a thickness of 1000 μm using a vacuum evaporation method (10-5 Tarr) to form a charge retention medium. I got it.

The charge retention medium was charged by corona charging to a surface potential of +100 V or -100 V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature for 30 days was 95V for both + and - (hereinafter the same)! 1 hold, 60 as an accelerated test
℃, 20%R,) 1. 95V even when left for 30 days
It maintains a surface potential of 40℃, 95%R, l
(, even under humid conditions left for 30 days, the surface charge was 94
V was maintained.

[Example 2] Specific resistance I x 1016 Ω・am or more, water absorption rate 0.03
%, an Al electrode was laminated to a thickness of 1000 μm on a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) film (manufactured by DuPont) with a film thickness of 12 μm using a vacuum deposition (104↑orr) method, and the charge was A holding medium was obtained.

+100V on the resulting charge retention medium due to corona charging
Alternatively, it was charged to a surface potential of -100V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature and humidity for 30 days was 93V11 for both + and - (hereinafter the same), and 60V as an accelerated test.
℃, 20% R, 8, It maintains a surface potential of 90V even when left for 30 days, and it also maintains a surface potential of 90V at 40℃, 95% R, 8,
The surface charge of 90V was maintained even under humid conditions after being left for 30 days.

[Example 3] Vacuum evaporation (10-'T) onto a 1+nm thick glass substrate.

rr) method to deposit the electrode to a thickness of 1,000 layers. Then, on the E electrode, there is a fluorine-containing resin cytotube (product name: manufactured by Asahi Glass ■, water absorption rate 0.01%, specific resistance 1 x 101 Ω・Cm,
) was dissolved in perfluoro (2-butyltetrahydrofuran), and a 5% solution thereof was coated using a blade coater to prepare a charge retention medium with a thickness of 3 μm after drying.

The charge retention medium obtained above was charged by corona charging to a surface potential of -100V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature and humidity for 30 days was -90V.
Met. In addition, as an accelerated test, 60℃, 20%R, It
It maintained a surface potential of -85 V even after being left for 30 days, and maintained a surface charge of -90 V even under humid conditions of 40° C., 95% R, and 11 days left for 30 days.

[Example 4] Specific resistance 1Xl0"Ω"Cm or more, water absorption rate 0. A 25 μm thick film (manufactured by Nitto Denko Corporation) made of less than 0.1% polytetrafluoroethylene (PTFE) is laminated with an Al electrode to a thickness of 1000 μm by vacuum deposition (10” Torr) to maintain charge. Got the medium.

+100V on the resulting charge retention medium due to corona charging
Alternatively, it was charged to a surface potential of -100V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature and humidity for 30 days was maintained at 93V (hereinafter the same) and 60V as an accelerated test.
℃, 20% R, retains a surface potential of 90 V even when left for 8 or 30 days, and also maintains a surface potential of 90 V at 40° C., 95% R98,
The surface charge of 93V was maintained even under humid conditions after being left for 30 days. Furthermore, the surface potential of 90V was maintained even after being left for 10 hours under a high temperature condition of 150°C.

[Example 5] Vacuum deposition (10-5T) on a 1 mm thick glass substrate.

Al electrodes are laminated to a thickness of 1,000 layers using the rr) method. To that! It has a repeating unit of the above-mentioned binding margin (1) (n=1) on the electrode, and has an intrinsic viscosity [l] of Floriner) PC-
75 (trade name, manufactured by 3M ■) in a solvent mainly composed of perfluoro(2-butyltetrahydrofuran) at 30°C.
50, glass transition point 69°C, water absorption rate 0.01%,
A polymer with a specific resistance of 1xio''Ω・Cm was treated with perfluoro(
2-butyltetrahydrofuran), 5% of which
The solution was coated with a spin coater at 1500 rpm for 20 seconds.
After drying, a charge retention medium with a film thickness of 3 μm was prepared.

The charge retention medium obtained above was charged by corona charging to a surface potential of -100V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature and humidity for 30 days was -93V.
Met. In addition, as an accelerated test, 60℃, 20%R, 8,
It maintained a surface potential of -78V even when left for 30 days, and maintained a surface charge of -90V even under humid conditions of 40° C., 95% R, H and left for 30 days.

[Example 6] Vacuum deposition (10-'T) on a 1non-thick glass substrate.

rr) method to stack ^l electrodes to a thickness of 1000 layers. On the person's l electrode, the - Tsuzuriyo (1) (n=2) and the same (2)
) (n=2), and has an intrinsic viscosity [η]
is 0.55 at 30°C in a solvent mainly composed of perfluoro(2-butyltetrahydrofuran) manufactured by Fluorinert PC-75 (trade name, manufactured by 3M■), and the glass transition point is 108.
℃, a water absorption rate of 0.01%, and a specific resistance of 1X10''Ω・Cm were dissolved in perfluoro(2-butyltetrahydrofuran), and the 7% solution was coated with a spin coater for 15
Coated at 00 rpms 20 seconds, and after drying, the film thickness was 3 μm.
A charge retention medium was prepared.

The charge retention medium obtained above was charged by corona charging to a surface potential of -100V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature for 30 days was -90v.
Met. In addition, as an accelerated test, 60℃, 20% R0H,
It maintained a surface potential of -85V even when left for 30 days, and maintained a surface charge of -90V even under humid conditions of 40°C, 95% R, and 8.30 days.

[Example 7] Vacuum deposition (10-'T) was performed on a 1 mm thick glass substrate.

rr) method to stack ^l electrodes to a thickness of 1000 layers. On the electrode, a repeating unit consisting of the above-mentioned (1) (a blend of n = 1 and n = 2) and (2) (n = 2) and derived from perfluoroallyl vinyl ether. The ring structural unit is 54% by weight, and the intrinsic viscosity [η]
is 0.44 at 30°C in a solvent mainly composed of perfluoro(2-butyltetrahydrofuran) manufactured by Fluorinert PC-75 (trade name, manufactured by 3M■), and the glass transition point is 91°C.
A polymer having a water absorption rate of 0.01% and a specific resistance of 1X10"Ω"Cm was dissolved in perfluoro(2-butyltetrahydrofuran), and a 5% solution thereof was applied using a spin coater.
After drying, a charge retention medium with a membrane thickness of 3 μm was prepared.

The charge retention medium obtained above was charged by corona charging to a surface potential of -100V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature for 30 days was -90V.
Met. In addition, as an accelerated test, 60℃, 20%R, H0
It maintained a surface potential of -80 V even after being left for 30 days, and maintained a surface charge of -90 V even under humid conditions of 40° C., 95% R, H and being left for 30 days.

[Example 8] Vacuum deposition (10−
'T.

rr) method to stack ^l electrodes to a thickness of 1000 layers. On the ^l electrode, the - binding margin (1) (n eclipse 1) and - (C
Consisting of repeating units of F, -CF, )-, the ring structural unit derived from perfluoroallyl vinyl ether is 8
1% by weight, and the intrinsic viscosity (v) is 7oliner)F
C-75 (trade name, 0.425 at 30°C in a solvent mainly composed of perfluoro(2-butyltetrahydrofuran) manufactured by 3M@, water absorption 0.01%, specific resistance lXl0
A "Ω" Cm polymer was dissolved in perfluoro(2-butyltetrahydrofuran), and a 5% solution thereof was applied using a spin coater to produce a charge retention medium having a film thickness of 3 μm after drying.

The charge retention medium obtained above was charged by corona charging to a surface potential of -100V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature and humidity for 30 days was -93V.
Met. In addition, as an accelerated test, 60℃, 20% R, H,
It maintained a surface potential of -70V even after being left for 30 days, and maintained a surface charge of -90V even under humid conditions at 40°C and 95% R,I.

[Example 9] Vacuum evaporation (10-'T) onto a 1+nm thick glass substrate.

rr) Law Aj! The electrodes are stacked to a thickness of 1000 layers.

On the ^β electrode, the - binding margin (1) (n = 1) and -(
It consists of repeating units of CF, -CF)-C5Fy, and the ring structural unit derived from perfluoroallyl vinyl ether is 89% by weight,
and the intrinsic viscosity [η] is 0.35 at 30°C in a solvent mainly composed of perfluoro(2-butyltetrahydrofuran) manufactured by Fluorinert FC~75 (trade name, 3M ■),
Glass transition temperature 61t', water absorption 0.01%, specific resistance l
A polymer having a diameter of X10''Ω'cm was dissolved in perfluoro(2-butyltetrahydrofuran), and a 5% solution thereof was applied using a spin coater to produce a charge retention medium having a film thickness of 3 μm after drying.

The charge retention medium obtained above was charged by corona charging to a surface potential of -100V, and its charge retention performance was measured.

The surface potential measured after being left at room temperature for 30 days was -90v.
Met. In addition, as an accelerated test, 60℃, 20% R111
It maintained a surface potential of -60 V even after being left for 30 days, and maintained a surface charge of -90 V even under humid conditions of 40° C., 95% R, and 8.30 days.

[Reference Example 1]...Single-layer organic photoreceptor (PVK-TN
P) Preparation method Po IJ-N-vinylcarbazole 10g (manufactured by Anan Perfumery Co., Ltd.), 2.4.7-) dinitrofluorore 2210g 1
2 g of polyester resin (binder; manufactured by Byron 200 Toyo 817 Co., Ltd.), tetrahydrofuran (THF)
A mixed solution having a composition of 90 g was prepared in a dark place, and InJs
-3n02 was applied to a glass substrate (1 mm thick) sputtered to a thickness of about 1000 using a doctor blade, and dried with ventilation at 60°C for about 1 hour. I got it. In addition, in order to completely dry the sample, it was further air-dried for one day before use.

[Example 4] Electrostatic information recording and reproducing method As shown in FIG.
-TNF) 1 and the charge retention medium prepared in Example 1 were grounded using a polyester film having a thickness of IO μm as a spacer, with the charge retention medium surface facing the photoconductive layer surface of the photoreceptor.

Next, a DC voltage of 100 V was applied between both electrodes, with the photoreceptor side being positive and the resin layer side being negative.

With the voltage applied, exposure is performed from the photoconductor side for 1 second using a halogen lamp with an illuminance of 1000 lux as a light source, and the formation of the electrostatic latent image is completed.

Next, as shown in No. 4 TXJ, the potential difference between the electrode and the medium surface was measured. As a result, a surface potential of 100 V was measured on the medium surface using a surface potentiometer, but the surface potential in the unexposed area was OV.

〔Effect of the invention〕

In the charge retention medium of the present invention, the charge retention layer has a specific resistance of lXl0
By being made of a resin containing fluorine of 14 Ωcm or more, the information charge accumulated in the charge retention layer can be permanently retained, and the surface charge formed by the accumulated charge can be transferred to the electrode. It can be easily detected by a potential reading method that measures the potential difference between the electrostatic latent image and the electrostatic latent image.
Alternatively, it can be printed out using a printer.

In addition, since the information storage means is a unit of electrostatic charge, the information stored in the charge retention medium is of high quality and resolution, and the processing process is simple and can be stored for a long time. This information can be repeatedly played back at any desired image quality depending on the purpose.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing each aspect of the charge holding medium of the present invention, Fig. 2 is a perspective view showing various flexible charge holding media, and Fig. 3 is a charge holding medium of the present invention. 5 is a diagram showing an example of a potential reading method, and FIG. 5 is a diagram showing a schematic configuration of an electrostatic image recording and reproducing method using the charge retention medium of the present invention. In the figure, 1 is a photoconductor, 3 is a charge retention medium, 5 is a photoconductive layer support, 7 is a photoconductor electrode, 9 is a photoconductive layer, 11 is a charge retention layer, 12 is a charge retention layer missing portion, and 13 is a charge holding medium electrode,
15 is a charge retention layer support, 16 is an adhesive layer, 17 is a power source,
18 is a pattern exposure light, 21 is a potential reading section, 23 is a detection electrode, 25 is a guard electrode, and 27 is a capacitor. Part 2 (a) (b) Part (a) (b) (C) Part 2 (c) (d) 1.

Claims (6)

[Claims] (1) A charge retention medium having at least an electrode layer and a charge retention layer, wherein the charge retention layer is made of a resin containing fluorine. (2) The charge retention medium according to claim 1, wherein the fluorine-containing resin is a tetrafluoroethylene-hexafluoropropylene copolymer. (3) The charge retention medium according to claim 1, wherein the fluorine-containing resin is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer. (4) The charge retention medium according to claim 1, wherein the fluorine-containing resin is polytetrafluoroethylene. (5) The above fluorine-containing resin is expressed by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and/or the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, n is 1 or 2) 2. The charge retention medium according to claim 1, which is a fluorine-containing thermoplastic resin consisting of repeating units having a ring structure, and having a molecular weight such that the intrinsic viscosity at 50° C. is at least 0.1. (6) The above fluorine-containing resin is expressed by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and/or the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, n is 1 or 2) There are repeating units (a) of the ring structure, general formulas, ▲mathematical formulas, chemical formulas, tables, etc.▼ (However, X is F, Cl, -O-CF_2CF_2CF_
3, -O-CF_2CF(CF_3)OCF_2CF_
2SO_3F, -O-CF_2CF_2CF_2COO
consisting of repeating units (b) represented by CH_3), containing at least 80% by weight of repeating units (a), and containing 50% by weight of repeating units (a)
The charge retention medium according to claim 1, which is a fluorine-containing thermoplastic resin having a molecular weight such that the intrinsic viscosity at ℃ is at least 0.1.