JPS6119032B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to electrophotography.

There are many types of electrophotography. For example, as a typical electrophotographic method using a photoreceptor consisting of a support and a photoconductive layer, there is a method consisting of charging, image exposure, development, and transfer steps. As an electrophotographic method using an electrophotographic photoreceptor composed of an insulating layer and an insulating layer, for example, US Pat.
41-16429, 1974-15446, 1971-3713, 1972-23910, 43-24748, 19747,
It is described in Japanese Patent Publication No. 36-4121, etc.

Nowadays, when electrophotographic copying machines are widely used, it would be extremely useful to provide an electrophotographic method that allows for the simplification of copying devices.

Among them, for example, as described in JP-A-48-90241, JP-A-48-90240, etc., a toner image formed on the surface of an electrophotographic photoreceptor is transferred onto the photoreceptor. There is a method of simultaneously transferring and thermally fixing the image onto a transfer material such as paper. In this method of simultaneously transferring and thermally fixing the toner image formed on the surface of the photoreceptor to a transfer material, it is necessary to ensure that the photoreceptor itself is thermally stable and that the surface of the photoreceptor has good releasability at high temperatures. When a toner image that attracts charge is thermally fixed at the same time as transfer, charge disturbance occurs due to heat.
The photoreceptor is required not to cause any disturbance in the transferred image.

However, conventional photoconductors, including the photoconductor described in the above publication, do not meet all of the above requirements, and this point has led to the proposal of a simultaneous transfer and heat fixing method on the surface of the photoconductor as a technical concept. Despite this, it has not been put into practical use until now.

The present invention has been made in view of the above-mentioned points, and uses a specific photoreceptor as a photoreceptor that can realize the conceptually proposed simultaneous transfer and heat fixing on the surface of a photoreceptor at a practical level. The point is that it was developed.

The present invention is an electrophotographic method characterized in that a toner image formed on the surface of an electrophotographic photoreceptor having a photoconductive layer made of amorphous silicon containing 10 to 40 at % of hydrogen is transferred to a transfer material and simultaneously heated and fixed. It is.

Transferring and heat-fixing the toner image formed on the surface of the photoreceptor to a transfer material at the same time has the advantage of physically shortening the processing steps and simplifying the apparatus, compared to post-transfer heat-fixing. In addition, by using the above-mentioned specific photoconductor, it is possible to raise the temperature to a higher temperature than before, and at the same time, the release property at high temperatures is good, so the transfer rate of toner to the transfer material is significantly improved while maintaining high image quality. Improved.

In the present invention, as described above, by employing an amorphous silicon layer (hereinafter referred to as "A-Si:H layer") containing 10 to 40 atomic percent hydrogen as the photoconductive layer, simultaneous transfer heating is possible. This was accomplished smoothly.

The basic structure of the photoreceptor used in the present invention is a support and a support formed thereon.

Examples of the support include styrene, Al, Cr,
A conductive support such as a metal such as Mo, Au, Ir, Nb, Ta, V, Ti, Pt, Pd or an alloy thereof, or
An electrically insulating support such as a film or sheet of synthetic resin, glass, ceramic, etc., which is optionally subjected to a series of cleaning treatments before the A-Si layer is deposited on the support. In such a cleaning treatment, generally, for example, if the support is made of metal,
Contact with an alkaline or acidic solution effectively cleans the surface by etching. after that,
The support is dried in a clean atmosphere and then A-Si
is deposited on the support.

In addition, in the case of an electrically insulating support, its surface is subjected to conductive treatment, if necessary.

For example, in the case of glass, its surface is conductively treated with In ₂ O ₃ or SnO ₂ , or in the case of a synthetic resin film such as polyimide film, it is treated with Al, Ag,
Pb, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, V,
The surface is treated with a metal such as Ti or Pt by vacuum evaporation, electron beam evaporation, sputtering, etc., or laminated with the metal, so that the surface thereof is conductive. The shape of the support body is cylindrical, belt-shaped,
It may have any shape, such as a plate shape, and the shape is determined as desired, but in the case of continuous high-speed copying, it is preferably an endless belt shape or a cylindrical shape.

The thickness of the support is determined as appropriate, but if flexibility is required, it is made as thin as possible within a range that allows the support to function satisfactorily.

However, in such a case, the thickness is usually set to 10μ or more in view of manufacturing and handling of the support, mechanical strength, etc.

The A-Si:H layer is usually formed on a support by a deposition method such as a glow discharge method, a sputtering method, an ion plating method, or a vacuum evaporation method. Glow discharge method, sputtering method and ion plating method are deposition methods that utilize discharge phenomenon.
This is a particularly effective method of forming an A-Si:H layer of a required thickness by maintaining a gas plasma atmosphere in a deposition chamber for a predetermined period of time.

As the material for forming the A-Si:H layer, in addition to silicon alone, a silicon compound that decomposes during deposition to produce silicon is used. Typical examples of such silicon compounds are silicon hydrogen compounds such as SiH ₄ and Si ₂ H ₆ . Regarding the formation of the A-Si:H layer, it is also effective to add at least one of oxygen, nitrogen, and carbon as necessary to control the dark resistance and photoelectric gain of the a-Si:H layer. .

A typical method for incorporating hydrogen (H) into the A-Si:H layer is to
It is introduced in the form of compounds such as SiH ₄ , Si ₂ H ₆ and/or H ₂ , and those compounds or
H ₂ can be decomposed and incorporated into the A-Si:H layer as the layer grows. A-Si:H
When using a silicon hydride compound such as SiH ₄ or Si ₂ H ₆ as a layer forming material, silicon in this compound can be used as the main component for forming the A-Si:H layer, so silicon alone or other Although it is not necessary to use a silicon compound in combination, these silicons alone or other silicon compounds may be used in combination as necessary.

The amount of H contained in the A-Si:H layer is usually 10 to 40 atomic% as described above, but preferably
The content is preferably 15 to 30 at%. A-Si:H
The inclusion of H in the layer is, for example, in the glow discharge method, when the starting material for forming A-Si:H is SiH ₄ ,
Since hydrogen compounds such as Si ₂ H ₆ are used, depending on the selection of conditions, when hydrogen compounds such as SiH ₄ and Si ₂ H ₆ are decomposed to form an A-Si:H layer, H is automatically removed from the layer. However, in order to more efficiently incorporate H into the layer, when forming the A-Si:H layer,
It is sufficient to introduce H ₂ gas into the apparatus system that performs glow discharge.

When using the sputtering method, H ₂ gas is introduced when performing sputtering with silicon as a target in an inert gas such as Ar or a mixed gas atmosphere based on this gas, or SiH ₄ , Si ₂ H ₆ A silicon hydride gas such as B ₂ H ₆ or PH ₃ may be introduced to also serve as impurity doping.

When oxygen, nitrogen, and carbon are contained in the A-Si:H layer, the same method as when hydrogen is contained can be used.

Oxygen, nitrogen, and carbon may be contained in the A-Si:H layer using these elements alone or in compounds of these elements.

Such oxygen compounds include SiO ₂ ,
Nitrogen compounds such as Si ₃ N ₄ , CO, CO ₂ , etc.
Examples of carbon compounds such as NO, _NO2 , and _NH5 include saturated hydrocarbons having 1 to 4 carbon atoms, ethylene hydrocarbons having 2 to 4 carbon atoms, acetylene hydrocarbons having 2 to 3 carbon atoms, and the like. For example, saturated hydrocarbons include methane (CH ₄ ), ethane (C ₂ H ₆ ), propane (C ₃ H ₈ ), and n-butane (n-C ₄ H ₁₀ ), and ethylene hydrocarbons include ethylene (C ₂ H ₄ ), propylene (C ₃ H ₆ ), butene-1 (C ₄ H ₅ ), butene-2
(C ₄ H ₆ ), isobutylene (C ₄ H ₈ ), and acetylene hydrocarbons include acetylene (C ₂ H ₂ ) and methylacetylene (C ₃ H ₄ ).

To form the A-Si:H layer, for example, a gas of a compound such as oxygen, nitrogen, oxide, nitride, or carbide is added to the A-Si:H layer.
A photoconductive layer may be formed by introducing the material together with a raw material gas for forming Si:H into a deposition chamber whose interior can be reduced in pressure and causing glow discharge within the deposition chamber. Furthermore, when forming a photoconductive layer by sputtering, for example, (Si+C), (Si+SiO ₂ ), (Si+
Sputtering can be carried out by using a sputtering target made of a mixture of Si ₃ N ₄ ), or by using two targets of a Si wafer and a C, SiO ₂ or Si ₃ N ₄ wafer, or by using oxygen A-Si:H is formed by introducing gas, nitrogen gas, or a compound gas containing carbon, oxygen, or nitrogen into the deposition chamber together with a sputtering gas such as Ar gas, and performing sputtering using a Si target. All you have to do is form a layer.

The amount of oxygen, nitrogen or carbon incorporated into the A-Si:H layer is set appropriately, but in normal cases,
Desirably, the content is 0.1 to 30 atom %, preferably 0.1 to 20 atom %, most preferably 0.2 to 15 atom %.

When the A-Si:H layer is formed by a deposition method that utilizes a discharge phenomenon, the discharge current density is usually adjusted to generate a discharge phenomenon in the deposition chamber that is effective for forming the desired plasma atmosphere. is 0.1~10mA/ ^cm2
The AC or DC current is preferably 1 to 5 mA/ ^cm2 , and in order to obtain sufficient power, the voltage is usually adjusted to 100 to 500 V, preferably 300 to 500 V. The power used is usually 0.1~
The power is preferably 50W, preferably 0.5 to 10W.
Furthermore, in the case of AC, its frequency is usually 0.2
It is desirable that the frequency is ~30MHz, preferably 5~20MHz.

The A-Si:H layer can be made intrinsic by doping with impurities during manufacture and its conductivity type can be controlled.

In order to make the A-Si:H layer P-type, impurities doped into the A-Si:H layer include elements from group A of the periodic table, such as B, Al, Ga, In, and Tl. Preferred examples include elements of group A of the periodic table when n-type, such as N, P,
Preferred examples include As, Sb, Bi, and the like.

The amount of impurities doped into the A-Si:H layer is determined appropriately depending on the desired electrical and optical properties, but in the case of impurities in group A of the periodic table, it is usually 10 ^-6 ~10 ^-3 atomic %, preferably 10 ^-5 to ^{10 -4}
Atomic %, in the case of impurities in group A of the periodic table,
It is usually 10 ^-3 to 10 ^-8 atomic %, preferably 10 ^-5 to ^{10 -7} atomic %.

The method of doping these impurities into the A-Si:H layer differs depending on the manufacturing method adopted when forming the A-Si:H layer, and the details are explained below. Or it will be explained in detail in the examples.

The layer thickness of the A-Si:H-based photoconductive layer is determined as appropriate depending on the desired electrophotographic properties and usage conditions, for example, whether flexibility is required or not. Usually 5~80μ, preferably 10~
It is desirable that the thickness be 70μ, optimally 10 to 50μ.

A representative embodiment of the invention is shown in FIG. An electrostatic image is formed on the photoreceptor by an appropriate electrophotographic process, and this electrostatic image is developed with toner (developer) and converted into a toner image. A toner image 7 is formed on the surface of the photoreceptor consisting of the support 1 and the A-Si layer 2. A heat fixing roller 5, which is a typical type of fixing means, is positioned to press the surface of the photoreceptor, and the transfer material 4 passes between the photoreceptor and the heat fixing roller. As the photoreceptor rotates in the direction of arrow 3 and the heat fixing roller rotates in the direction of arrow 6, the transfer material 4 moves in the direction of arrow 9. The toner image 7 formed on the surface of the photoreceptor is transferred to the surface of the transfer material as a toner image 8. Thereby, simultaneous transfer and heat fixing of the toner image is achieved. As the transfer material, paper, cloth, resin film, metal foil, etc. are used as appropriate. The heat fixing roller preferably has an elastic surface. The heat fixing roller may be heated by providing a heater in the hollow part of the heat fixing roller, or by installing a heater at an appropriate position where the heat fixing roller can be heated. Further, instead of the heat fixing roller, a heat fixing belt 10 as shown in FIG. 2 may be used. Heat fixing belt 10 rotates in the direction of arrow 11. Heating of the toner image is normally performed by a fixing pressure means such as a fixing roller or a fixing belt, but in special cases, the transfer material itself is heated before the transfer material reaches the fixing pressure means. In other cases, the heater 1 can be heated to the required temperature, as shown in FIG.
It is also effective to apply electricity and heat using a flash heater or a flash heater when necessary. Further, if necessary, auxiliary heating means may be used in combination after the transfer. The heating temperature is set appropriately depending on the type of toner, etc., but it is usually 100 to 250℃, especially 150℃.
~200°C is preferred. It is also effective to set a fixing means such as a fixing roller that is pressed against the surface of the photoreceptor in a state in which the pressure is released except during fixing. Furthermore, the heating may be performed by irradiating radiation such as infrared light, visible light, and ultraviolet light. In order to transfer the toner image more completely, silicone oil, fluorine resin, fluorine wax, talc, carbon fluoride, silicone wax, hydrocarbon wax, hydrocarbon oil, etc. may be applied to the surface of the photoreceptor as necessary. It is also effective to apply a releasable material continuously or intermittently.

The photoreceptor used in the present invention may have the structure shown in FIG. 1, or may have an insulating layer further formed on the A-Si layer, if necessary.

When an insulating layer is attached with the main purpose of protecting the photoreceptor, improving its durability, dark decay characteristics, etc., the insulating layer is set relatively thin. The layer is set relatively thick.

Usually, the thickness of the insulating layer is set to 0.1 to 100 μm, particularly 0.1 to 50 μm.

As the resin used for forming the insulating layer, a normal resin can be used as appropriate. For example, polyethylene, polyester, polypropylene, polyimide, phenolic resin, urea resin, polyurethane, polystyrene, polyvinyl chloride, polyvinyl acetate, polyphenylene oxide, polyphenylene sulfide, acrylic resin, polycarbonate, silicone resin, fluororesin, epoxy resin, etc. In particular, resins with excellent heat resistance such as silicone resin, polyimide resin, polyacrylate resin, polycarbonate resin, or a mixture of these resins are recommended.

Example 1 A photoconductive layer was formed in the following manner using the apparatus shown in FIG. 4, and a predetermined image forming process was performed on the photoconductive layer to form an image. That is, the surface is treated using a 1% NaOH solution, thoroughly washed with water and dried to clean the surface, an aluminum drum 1 with a diameter of 100 mm and a length of 350 mm is prepared, and a glow discharge deposition chamber 1 is prepared.
The heater 15 was firmly fixed to a predetermined position of a fixing member 14 in a predetermined position within the heater 15 at a distance of about 10 cm.

Next, the main valve 16 is fully opened to open the deposition chamber 1.
The air inside the chamber was evacuated to create a vacuum of approximately 5× _{10 −5} ^torr . Thereafter, the heater 15 was ignited to uniformly heat the aluminum drum to 150° C., and the temperature was maintained at this temperature. After that, fully open valve 17,
Subsequently, after fully closing the valve 19 of the cylinder 18 and the valve 21 of the cylinder 20, the flow rate adjustment valves 22 and 23 are gradually opened to supply Ar gas from the cylinder 18 and SiH ₄ gas from the cylinder 20 into the deposition chamber 15. It was introduced in

At this time, adjust the main valve 16 to
The degree of vacuum inside 3 was maintained at 0.75 torr.

Subsequently, the switch of the high frequency power supply 24 was turned on and a high frequency of 13.56 MHz was applied between the electrodes 25 and 25' to cause glow discharge and form an A-Si:H layer on the aluminum substrate. The glow discharge power at this time was about 5W. Also, A-Si:H at this time
The growth rate of the layer was about 4 Å/sec, and the deposition was carried out for 15 hours, and a 20 μ thick A-layer was deposited on an aluminum drum.
A Si:H based conductive layer was formed.

Next, the flow control valves 22 and 23 were closed, and the high frequency power source 24 was turned off to stop the glow discharge.

The aluminum drum on which the A-Si:H-based photoconductive layer was formed in this way was taken out of the apparatus, and the first
It was attached to a copying machine having the configuration shown in the figure, an electrostatic latent image was formed by the following process, magnetic brush development was performed using dry positive toner, and simultaneous copying and fixing was performed.

A 6kV corona charge is applied to the surface of the A-Si:H photoconductive layer, and a light image is irradiated after 0.2 seconds to increase the dark area potential to 500V.
An electrostatic latent image with a contrast of a bright area potential of 5 V was obtained, and after 0.2 seconds, dry positive toner magnetic brush development was performed, and the image was transferred and fixed onto transfer paper by a transfer fixing mechanism having the configuration shown in Fig. 1. .

Set the surface temperature of the heat fixing roller to 180℃,
When the transfer paper reaches the toner image area on the surface of the A-Si:H photoconductive layer, it is pressed into contact with the toner image area to complete the transfer and fixation of the toner onto the transfer paper.
The mechanism is such that it separates from the surface of the Si:H photoconductive layer. A cooling device is attached to the back of the drum having the A-Si:H photoconductive layer to prevent the temperature from rising above 50 DEG C. due to heat from the transfer and heat fixing rollers. In this example, cooling was performed using a water cooling coil, and the results were good. The images obtained in this way have sufficient sharpness and contrast,
Even after copying 50,000 copies, I was able to obtain the same image quality as the initial image quality.

Example 2 Similarly to Example 1, an organic solvent dispersion of fluororesin (trade name: Polyflon Enamel, manufactured by Daikin Industries) was applied to the A-Si:H photoconductive layer prepared on a stainless steel drum at 200 cps with thinner. An insulating layer with a thickness of 10 μm was applied once by dilution and dipping at 400°C.
Dry for 20 minutes and cool. 10μ on top of that
A thick insulating layer was provided to obtain a photoreceptor composed of three layers: substrate A--Si:H photoconductive layer and insulating layer. Then the third
The obtained photoreceptor was attached to a copying machine having the mechanism shown in the figure, and an image was printed by the following process.

In FIG. 3, a halogen lamp (800W) is arranged as the heater 12, and the lamp is turned on in synchronization with the passage of the transfer paper, completing the transfer and fixing. (Additionally, a heater may be provided to complete the fixation after transfer. In this case, the transfer lamp only needs to supply the amount of heat necessary for transfer, so the wattage of the halogen lamp should be lowered.) can be done.)
A 6.5 kV corona charge is applied, followed by a 7 kV corona charge, and at the same time a 10 lux sec light image is irradiated.
After 0.2 seconds, expose the entire surface to 100 lux sec to remove dark areas.
An electrostatic latent image with a contrast of 500V bright area and 100V was obtained. Next, dry negative toner and magnetic brush development were performed, and the transfer and fixation of the structure shown in FIG. 3 was carried out on a transfer paper, and a good copied image without sharpness, contrast, or fog could be obtained. When the above process was repeated 100,000 times, it was possible to obtain a good image that was not significantly different from the initial image.

Example 3 When carrying out the electrophotographic process using the photoreceptor having the A-Si:H photoconductive layer in Example 1,
When silicone oil (product name: SH200, manufactured by Toray Silicon Co., Ltd.) in Å units was supplied to the surface of the A-Si:H photoconductive layer image, the initial image quality and sharpness contrast remained unchanged even after 100,000 copies were made. I was able to get good image quality. By using silicone oil, it was possible to further prevent toner from adhering to the A-Si:H photoconductive layer and to increase transfer efficiency.

[Brief explanation of the drawing]

1, 2, and 3 each show one embodiment of the simultaneous transfer and heat fixing by the electrophotographic method of the present invention. FIG. 4 shows one embodiment of a photoconductive layer manufacturing apparatus used for manufacturing the photoreceptor used in the present invention. DESCRIPTION OF SYMBOLS 1...Support, 2...A-Si:H photoconductive layer, 4
...Transfer material, 5...Heating fixing roller, 7, 8...
Toner image, 10... Heat fixing belt, 12...
heater.

Claims (1)

[Claims] 1. A toner image formed on the surface of an electrophotographic photoreceptor having a photoconductive layer made of amorphous silicon containing 10 to 40 atomic percent hydrogen is transferred to a transfer material and simultaneously heat-fixed. electrophotography. 2. The electrophotographic method according to claim 1, wherein a releasable material is provided on the surface of the electrophotographic photoreceptor. 3. The electrophotographic method according to claim 1, wherein the fixing means is pressed against the surface of the electrophotographic photoreceptor during transfer and fixing. 4. The electrophotographic method according to claim 1, wherein the photoconductive layer contains at least one of oxygen, nitrogen, and carbon. 5. The electrophotographic method according to claim 4, wherein the content of at least one of oxygen, nitrogen, and carbon is 0.1 to 30 atomic %.