JPH0713416A - Developer carrying member and developing device, electrophotographic device and facsimile formed by using the same - Google Patents

Abstract

PURPOSE:To obtain uniform, stable and high-grade images free from uneven densities, etc., by laminating plural resin layers varying in contents of conductive materials, such as carbons, onto a base body of the developer carrying member, thereby forming the developer carrying member. CONSTITUTION:A developing sleeve 8 which is the developer carrying member consists of a metallic cylindrical pipe which is the metallic base body and the resin layers 6, 7 clad on the outer periphery of the base body. The resin layers 6, 7 are composed of laminated films consisting of at least two layers; a surface layer 7 having the high content of the conductive materials, such as carbons and the lower layer 6 having the content of the conductive materials, such as carbons, lower than in the surface layer. As a result, the control of the electrostatic charge imparting capacity of the developing sleeve in the first half and second half of image producing durability is possible. Namely, the content of the conductive materials, such as carbons, is high in the surface layer 7 and the carbons are exposed more on the surfaces and, therefore, the contact chances of the constituting resin components of the resin layers 6, 7 and the toners are decreased and a charge-up is prevented in the first half of the image producing durability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer carrier and various apparatuses using the same, and more specifically, to a latent image formed on an image carrier such as an electrophotographic photoreceptor or an electrostatic recording derivative. A developer carrier used when developing and visualizing an image,
The present invention relates to a developing device, an electrophotographic device and a facsimile using the same.

[0002]

2. Description of the Related Art Conventionally, for example, in a developing device for developing an electrostatic latent image formed on the surface of a photosensitive drum as an image carrier with a magnetic toner of a one-component developer, friction between magnetic toner particles, and By friction between the developing sleeve as a developer carrier and the magnetic toner particles, the electrostatic latent image charge on the photosensitive drum and a charge having a polarity opposite to the developing reference potential are applied to the magnetic toner particles, and the magnetic toner particles are applied to the developing sleeve. Is applied very thinly to the developing area where the photosensitive drum and the developing sleeve face each other, and the magnetic toner of the magnet immovably installed in the developing sleeve in the developing area causes magnetic toner to move the magnetic toner to the electrostatic latent surface of the photosensitive drum. It is known that an electrostatic latent image is visualized as a toner image by flying and adhering to an image to develop it. As the developer carrier used in these methods,
For example, as disclosed in JP-A-57-66455, a metal such as aluminum, nickel and corrosion resistant steel (stainless steel), an alloy thereof, or a compound thereof is molded into a cylindrical shape, and the surface thereof is subjected to electrolysis, blasting and sanding. Those processed to have a predetermined surface roughness by a method such as the above are generally widely used. In addition to being inexpensive, these developer carrying members can relatively stably form high-quality images.

[0003]

However, in the developing method using the conventional developer carrier as described above, and using the one-component developer which is charged by friction between the developer carrier and the toner, Although it is difficult to adjust the charge imparting to the toner and various devises have been made on the developer, the problems relating to the non-uniform charging of the toner and the durability stability of the charging have not been completely solved. In particular, in the developing step, the developer existing in the vicinity of the surface of the developer carrier in the developer layer formed on the surface of the developer carrier by the regulating member has a very high electric charge, so that the surface of the developer carrier is As a result of being strongly attracted to the
Since there is no chance of friction between the toner and the developer carrier, the developer cannot have a suitable charge. Under such a situation, there is a problem that sufficient development and transfer are not performed, and an image with many image density unevenness and scattering of characters is generated.

On the other hand, as a method of reducing the developer having an excessively high charge as described above and imparting a suitable charge amount for development, as disclosed in JP-A-2-105181, etc. By providing a resin coating in which a conductive agent such as carbon and graphite is dispersed on the metal base of the developer carrying member, the developer is electrically charged and at the same time,
The purpose of the present invention is to prevent the generation of a highly charged developer and the strong adhesion to the developer carrier due to the mirror power of the developer, and to provide the toner on the developer carrier with a charge amount suitable for development. A proposal has been made to do so. However, this is not enough. A further problem is that the density of the image changes during the durability test. It is considered that this is mainly related to changes in the physical properties of the toner during durability. That is, because the toner has microscopic variations in its components, or has a particle size distribution,
The toner remaining in the developing machine after endurance changes. That is, since these toners are carried on the developing carrier, the properties of the toner to be developed change. In particular, such a phenomenon remarkably occurs at the early stage or the late stage of durability. Therefore, a developing mechanism capable of obtaining a stable image even under such a situation is desired.

Therefore, it is an object of the present invention that the developer placed on the developer carrying member has a stable and proper electric charge, and is capable of obtaining a stable and high-quality image having no density unevenness. Another object of the present invention is to provide a developer carrier and various devices (developing device, electrophotographic device and facsimile) using the same. Another object of the present invention is to provide a developer carrying member which can provide a clear image without scattering of characters, thickening and thinning, and various apparatuses using the same. Further, an object of the present invention is to provide a developer carrier capable of obtaining a stable and high-quality image which does not cause a decrease in image density or uneven density even when it is repeatedly used, and various devices using the same. Especially.

[0006]

The above objects can be achieved by the present invention described below. That is, according to the present invention, in a developer carrier in which a resin layer in which a conductive substance such as carbon is dispersed is provided on a metal substrate, the resin layer has a surface containing a large amount of conductive substance such as carbon. Layer and a developer coating comprising at least two lower layers containing less conductive material such as carbon than the surface layer, developing device using the same, electrophotographic device And a facsimile.

[0007]

As a result of intensive studies to solve the above-mentioned problems of the prior art, the present inventors have found that two or more resin layers having different contents of conductive substances such as carbons on the substrate of the developer carrier. If the surface layer is a layer having a high content of a conductive substance such as carbons, and the lower layer is a layer having a low content of a conductive substance such as carbons compared to the surface layer, It is possible to control the charge imparting ability of the developer carrier,
It has been found that the developer placed on the developer carrier has a stable and appropriate electric charge, and can be a developer carrier capable of obtaining a stable, high-quality image that is uniform and has no uneven density. The present invention has been completed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. The developer carrier of the present invention is composed of a metal cylindrical tube which is a metal substrate and a resin layer coated on the outer periphery thereof, and the resin layer is a surface layer containing a large amount of a conductive substance such as carbons, At least two lower layers containing less conductive material such as carbon than the surface layer
It is characterized in that it is composed of a laminated film composed of layers.

In the developer carrier of the present invention, the resin layer has a laminated film structure composed of at least two layers having different contents of conductive substances such as carbons for the following reason. That is, the toner is produced with a certain particle size distribution due to its production technology. Furthermore, there are some variations in the dispersed state of the material. Therefore, when individual toner particles are taken and observed, particles having a high charge amount retention property and particles having a low charge amount coexist. By the way, magnetic force and electrostatic force mainly contribute to the force for carrying the toner on the developer carrying member. In particular, the force of accumulating the fine toner powder on the surface of the developer carrying member in the initial stage is largely due to the electrostatic force. At this time, if the toner fine powder is excessively accumulated on the developer carrying member, a phenomenon called charge-up occurs, which makes it difficult for the toner to be developed and causes a phenomenon of low image density. Even when such a phenomenon does not occur, the toner is carried on the developer carrying member from the fine powder side of the toner having a particle size distribution and is consumed. In that case, toner of coarse particles having a low charge amount retention and a coarse particle size remains, which also causes a phenomenon of low image density obtained in this case.

Therefore, under the above circumstances, what is required is a developer carrying member having a small charge imparting ability in the first half of image development durability and a large charge imparting ability in the latter half. Generally, charging is performed by a developer carrier (developing sleeve)
Depending on the surface material and the charging series of the toner, a resin layer with a small charge imparting property and a high content of conductive substances such as carbon is provided on the surface, and a conductive layer such as carbon is contained underneath. By providing a resin layer with a small amount, it becomes possible to control the charge imparting ability of the developing sleeve in the first half and the latter half of the image development durability. That is,
The surface layer contains a large amount of conductive substances such as carbons,
Since a large amount of carbon is generated on the surface, it is possible to reduce the chance of contact between the resin component constituting the resin layer and the toner in the first half of image formation durability, and prevent the charge-up phenomenon. Further, the advantage of the resin layer having a laminated film structure including at least two layers having different contents of conductive substances such as carbons is that the upper layer having a large content of conductive substances such as carbons is Since it is more brittle than the lower layer containing less conductive substance, it is gradually scraped off during image formation to prevent toner from adhering to the developing sleeve, and at the same time, in the latter half of durability, carbons with high charge imparting properties, etc. The lower layer containing less conductive substance appears on the surface of the sleeve.
Here, when the toner is developed, the content of the conductive substance such as carbon does not necessarily need to be linearly reduced because there is a certain width of the developable region. Therefore, any number of layers having different carbon contents may be provided, but a two-layer structure is often sufficient.

As the metal substrate used in the developer carrying member of the present invention, for example, a metal cylindrical tube made of, for example, stainless steel or aluminum is preferably used.
Further, the resin coating layer provided on the above-mentioned metal cylindrical tube which characterizes the present invention is a mixture containing at least a resin and a conductive substance. The respective materials and the mixing ratio can be arbitrarily selected depending on the properties of the toner and the developing conditions. Generally, the ratio (PB ratio) of the resin (B) and the conductive substance (P) is P / B.
= 1/20 to 4/1 is preferably set. 1/2
When it is 0 or less, the effect of adding the conductive substance is hardly obtained, and 4 /
When it is 1 or more, the resin layer becomes very brittle, and the resin layer is severely scraped.

In the present invention, the resin layer is formed by laminating at least two kinds of resin mixtures having different ratios (PB ratio) of the resin (B) and the conductive substance (P). That is,
It has at least two layers, a surface layer containing a large amount of a conductive substance and a lower layer containing a smaller amount of a conductive substance than the surface layer. The difference in the ratio (PB ratio) between the resin (B) and the conductive substance (P) in each layer to be laminated is, for example, P / B = 3/2 in the surface layer: P / B = 1/2 in the lower layer, P / B of surface layer = 5/4: P / B of lower layer = 3/10, P of surface layer
/ B = 2/1: P / B of middle layer = 1/1: P / B of lower layer =
It will be 4/10. The thickness of the resin layer formed is usually 2
The thickness is preferably 0 μm or less in order to obtain a uniform film thickness, but is not particularly limited.

The conductive material used in the developer carrying member of the present invention includes, for example, metal powder such as aluminum, copper, nickel and silver, metal short fiber, carbon fiber,
Examples of the conductive powder include carbon black and graphite. Among them, graphite is suitable for use in the present invention because it has conductivity and lubricity and can reduce toner adhesion on the developer carrying member.

Here, the crystalline graphite is roughly classified into natural graphite and artificial graphite. Artificial graphite is made by fixing pitch coke with tar pitch etc.
It was obtained by once calcining at a temperature of about ° C and then placing it in a graphitization furnace and treating it at a high temperature of about 2300 ° C to grow carbon crystals and transform it into graphite. Natural graphite is completely graphitized by natural geothermal heat for a long time and underground high temperature.
It is produced underground. These graphites have a wide range of industrial uses because they have various excellent properties. Graphite is a very soft, crystalline mineral with a dark gray to black luster, and is used for pencils and the like, and because it has excellent heat resistance and chemical stability, it is a lubricant, fire-resistant material, and electrical material. It is used in the form of powder, solid and paint. Some crystal structures belong to the hexagonal system and the other rhombohedral systems, and have a completely layered structure. In terms of electrical properties, there are free electrons between carbon-carbon bonds,
It is a good conductor of electricity. The graphite used in the present invention may be either natural or artificial, but the particle size is preferably 0.5 μm to 20 μm.

As the carbon fine particles used in the present invention, conductive amorphous carbon can be used. Conductive amorphous carbon is generally defined as “an aggregate of crystallites formed by burning or thermally decomposing a hydrocarbon or a compound containing carbon in a state where the supply of air is insufficient”. In particular, it is widely used because it is excellent in electric conductivity and can be filled with a polymer material to give conductivity, or it can obtain an arbitrary conductivity to some extent by controlling the addition amount. The particle size of the conductive amorphous carbon used in the present invention is 10 m.
Those having a thickness of from 80 to 80 m are preferred, and from 15 to 40
It is more preferably mμm.

The resin layer of the developer carrying member of the present invention is formed by dispersing a conductive substance such as carbon as described above in a resin. As the resin used at this time, any of various film-forming polymer materials can be used. Examples of the film-forming polymer material used in the present invention include:
Styrene resin, vinyl resin, polyether sulfone resin, polycarbonate resin, polyphenylene oxide resin, polyamide resin, fluororesin, fibrin resin,
Thermoplastic resin such as acrylic resin; thermosetting resin such as epoxy resin, polyester resin, alkyd resin, phenol resin, melamine resin, polyurethane resin, urea resin, silicone resin, polyimide resin; or photocurable resin Can be used. Among them, those having releasability such as silicone resin and fluorine resin, or machines such as polyethersulfone resin, polycarbonate resin, polyphenylene oxide resin, polyamide resin, phenol resin, polyester resin, polyurethane resin, styrene resin. More preferable are those having excellent physical properties.

The developer carrying member of the present invention is manufactured by the manufacturing method described below. First, at least two kinds of dispersion liquids are produced by changing the content of the conductive substance such as carbon described above in the various resins as described above.
As a method for dispersing a conductive substance in a resin, a mixture of a conductive substance having an appropriate content added to an arbitrarily selected resin, and methanol, isopropyl alcohol, or the like appropriately added to adjust the viscosity is used. , Using a sand mill, etc. Next, of the dispersion liquids prepared as described above, the dispersion liquid having the smaller content of the conductive substance is
Using a spray gun or the like, a uniform coating is applied onto a metal cylindrical tube of aluminum or the like so that the film thickness after drying will be about several μm. Next, while the film is in a dry state, a dispersion liquid containing a large amount of a conductive substance is further used on the film so that the film thickness after drying with a spray gun or the like is about several μm. Apply. After coating, the coating film is dried and cured by an oven dryer or the like to form the developer carrying member of the present invention.

Next, the developing device of the present invention using the developer carrying member of the present invention formed as described above will be described with reference to the drawings. In FIG. 1, an electrophotographic photosensitive drum 1, which is an image carrier that carries an electrostatic latent image formed by a known process, is rotated in the direction of arrow B. The developing sleeve 8 as a developer carrying member carries the magnetic toner 4 as a one-component magnetic developer supplied by the hopper 3 and rotates in the direction of arrow A, so that the developing sleeve 8 and the photosensitive drum 1 are separated from each other. The magnetic toner 4 is conveyed to the developing portion D facing each other. A magnet 5 is arranged in the developing sleeve 8 for magnetically attracting and holding the magnetic toner 4 on the developing sleeve 8. Further, the toner 4 is a developing sleeve.
By friction with the brush 8, triboelectric charges capable of developing the electrostatic latent image on the photosensitive drum 1 are obtained.

Further, in order to regulate the layer thickness of the magnetic toner 4 conveyed to the developing section D, a regulating blade 2 made of a ferromagnetic metal is provided from the surface of the developing sleeve 8 to about 200 μm to 300 μm.
It is suspended from the hopper 3 so as to face the developing sleeve 8 with a gap width of μm. Then, the magnetic lines of force from the magnetic pole N _{1 of the} magnet 5 are concentrated on the regulation blade 2, whereby a thin layer of the magnetic toner 4 is formed on the developing sleeve 8. A non-magnetic blade may be used as the regulation blade 2.

The thin layer of the magnetic toner 4 formed on the developing sleeve 8 is preferably thinner than the minimum gap between the developing sleeve 8 and the photosensitive drum 1 in the developing section D. The developer carrying member of the present invention is particularly effective for a developing device of the type that develops an electrostatic latent image with such a thin toner layer, that is, a non-contact developing type developing device. But,
In the developing section, the developer carrier of the present invention is also applied to a developing device in which the thickness of the toner layer is not less than the minimum gap between the developing sleeve 8 and the photosensitive drum 1, that is, a contact developing type developing device. You can To avoid complicated explanations,
In the following description, a non-contact developing type developing device will be taken as an example.

A developing bias voltage is applied to the developing sleeve 8 by a power source 9 in order to fly the toner 4 from the toner layer of the magnetic toner 4 which is a one-component magnetic developer carried on the developing sleeve 8 toward the photosensitive drum 1. Is applied. When a DC voltage is used as the developing bias voltage, a voltage between the potential of the image portion (the area where the toner 4 is adhered and visualized) of the electrostatic latent image and the potential of the background portion is applied to the developing sleeve 8. It is preferably applied. On the other hand, in order to increase the density of the developed image or improve the gradation, an alternating bias voltage may be applied to the developing sleeve 8 to form an oscillating electric field in which the direction is alternately inverted in the developing portion D. In this case, it is preferable that a DC voltage component having a value between the potential of the image portion and the potential of the background portion is applied to the developing sleeve 8 with an alternating bias voltage superimposed thereon.

Further, in so-called regular development in which toner is visualized by adhering toner to a high potential portion of an electrostatic latent image having a high potential portion and a low potential portion, the toner is charged to a polarity opposite to that of the electrostatic latent image. On the other hand, in so-called reversal development, in which toner is visualized by adhering toner to the low-potential portion of the electrostatic latent image, the toner is charged to the same polarity as the electrostatic latent image. The high potential and the low potential are expressed by absolute values. In any case, the magnetic toner 4 is charged with the polarity for developing the electrostatic latent image by friction with the developing sleeve 8. The silica externally added to the toner 4 is also charged by friction with the developing sleeve 8.

FIG. 2 is a block diagram showing another embodiment of the developing device of the present invention, and FIG. 3 is a block diagram showing still another embodiment of the developing device of the present invention. In the developing device of FIGS. 2 and 3, as a member for regulating the layer thickness of the toner 4 on the developing sleeve 8,
An elastic plate 20 made of a material having rubber elasticity such as urethane rubber and silicone rubber, or a material having metal elasticity such as phosphor bronze and stainless steel is used.
2 is brought into pressure contact with the developing sleeve 8 in the posture opposite to the rotation direction in the developing device of FIG. 2, and is brought into pressure contact with the developing sleeve 8 in the posture of the same rotational direction in the developing device of FIG. .

In these developing devices, a thinner toner layer can be formed on the developing sleeve 8. Incidentally, FIG.
The other configurations of the developing device shown in FIG. 3 are basically the same as those of the developing device shown in FIG. 1. In FIGS. 2 and 3, the same reference numerals as those shown in FIG. 1 denote the same members. As described above, the developing device for forming the toner layer on the developing sleeve 8 as shown in FIGS. 2 and 3 is a non-magnetic device that uses a one-component magnetic developer containing magnetic toner as a main component. It is also suitable for use with a one-component non-magnetic developer whose main component is toner. In any case, since the toner is rubbed against the developing sleeve 8 by the elastic plate 20, the triboelectric charge amount of the toner is increased and the image density is improved.

Next, the developer (toner) used to obtain a visible image by the developer carrier or the developing device of the present invention will be described. Toners are roughly classified into dry toners and wet toners. However, since wet toners have a large problem of solvent volatilization, currently dry toners are the mainstream. The toner is a fine powder in which a resin, a release agent, a charge control agent, a colorant and the like are melt-kneaded, solidified and then pulverized, and then the particle size distribution is made uniform by classification and the like. Generally, the toner having a weight average particle diameter of about 10 μm to 15 μm is mainly used. Further, recently, in order to improve the image quality of electrophotography, the particle size of toner has been reduced.

For example, in an electrophotographic laser beam printer, the print density is 60 times that of the conventional 300 dpi.
To realize a toner having a higher resolution of 0 dpi (23.6 pel), it is possible to faithfully reproduce an electrostatic latent image with higher resolution and sharpness, for example, by using a toner having a particle diameter of about 8 μm to 6 μm. Is relatively easy to solve. An example of such a small particle size toner is a one-component magnetic toner having a volume average particle size of 6.0 μm. Further, this one-component magnetic toner has a volume average particle size of 3.5 μm or less. Those having a number distribution of about 20% or less and those having a volume average particle diameter of 16 μm or more are contained at a ratio of about 1% or less in the volume distribution.

However, the above-mentioned small particle size toner has a larger specific surface area per volume as compared with a toner having a normal particle size, so that the charge amount per volume or weight is measured by the two-component triboelectrometry. In addition to the increase of about 30%, as described above, the amount of fine powder having a particle diameter of 5 μm or less increases, so that the surface of a developer carrying member such as a developing sleeve is caused by the high-friction electrified fine powder of the small particle diameter toner. Are easily contaminated, and a sleeve ghost and a decrease in image density are likely to occur. The sleeve ghost is a phenomenon in which an afterimage of a toner image portion before one rotation of the sleeve appears as a negative (low density) or a positive (high density) in a halftone image of the rotation portion of the sleeve. The developer carrying member of the present invention has an improving effect against such a sleeve ghost and the above-mentioned reduction in image density.

As the binder resin of the toner used in the present invention, generally known resins can be used. Specifically, for example, styrene such as styrene, α-methylstyrene, and p-chlorostyrene and their substitution products; acrylic acid,
Methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylic Monocarboxylic acids having double bonds such as diethylaminoethyl acidate, diethylaminoethyl methacrylate, acrylamide, etc. and substituted products thereof; having double bonds such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate, etc. Dicarboxylic acids and their substitutions;
Vinyls such as vinyl chloride, vinyl acetate, vinyl benzoate or vinyl esters; vinyl ethers such as vinyl ethyl ether, vinyl methyl ether, vinyl isobutyl ether, etc. Styrene-butadiene copolymer; silicone resin; polyester resin; polyurethane resin; polyamide resin; epoxy resin; polyvinyl butyral resin; rosin; modified rosin; terpene resin; phenol resin; fat Group or alicyclic hydrocarbon resins;
Aromatic petroleum resin; chlorinated paraffin, etc .; these may be used alone or in combination of two or more.

Further, the toner used in the present invention contains a colorant. Specifically, for example, carbon black, nigrosine dye, lamp black, Sudan black S
M, First Yellow G, Benzidine Yellow,
Pigment Yellow, India First Orange,
Irgadine Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Resor Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine blue, pigment blue, brilliant
Green B, Phthalocyanine Green, Oil Yellow GG, Zapon First Yellow CGC, Kayaset Y963, Kayaset YG, Sumiplast Yellow G
Pigments such as G, Zapon Fast Orange RR, Oil Scarlet, Sumiplast Orange G, Orazol Brown B, Zapon Fast Scarlet CG, Eisenspiron Red BEH, Oil Pink OP and the like can be appropriately used.

In order to use the toner used in the present invention as a magnetic toner, the toner may contain magnetic powder. As the magnetic powder used at this time, a substance that is magnetized by being placed in a magnetic field is used. For example, iron,
Examples include powders of ferromagnetic metals such as cobalt and nickel, or alloys and compounds such as magnetite, hematite, and ferrite. The content of magnetic powder is 15 with respect to the toner weight.
˜70 wt% is preferred.

Further, various releasing agents can be used in the toner used in the present invention. As such a release agent,
For example, polyfluorinated ethylene, fluororesin, fluorocarbon oil, silicone oil, low molecular weight polyethylene, low molecular weight polypropylene, etc. may be mentioned. Further, if necessary, a charge control agent may be added to facilitate positive or negative charging. Further, these toners used in the present invention may be used by adding a fluidity improver such as colloidal silica, if necessary. These fluidity improvers may be used after being treated with various silicone oils or various coupling agents in order to assist the charging of the toner as needed.

The developer carrying member of the present invention is used not only in electrophotographic copying machines, but also in laser beam printers,
It can be widely used in electrophotographic application fields such as CRT printers, LED printers, liquid crystal printers, printers for laser plate making and facsimiles. Figure 4
FIG. 1 shows a schematic configuration of a general transfer type electrophotographic apparatus using a drum type photoconductor on which the developer carrying member of the present invention is mounted.
In FIG. 4, reference numeral 41 denotes a drum type photosensitive member as a developer carrying member, which is rotationally driven around the shaft 41a in the arrow direction at a predetermined peripheral speed. In the course of rotation of the photoconductor 41, the peripheral surface of the photoconductor 41 is uniformly charged with a predetermined positive or negative potential by the charging means 42, and then the light exposure L ( Slit exposure or laser beam scanning exposure). As a result, electrostatic latent images corresponding to the exposed images are sequentially formed on the peripheral surface of the photoconductor 41.

The obtained electrostatic latent image is then developed by the developing means 44.
The toner is developed by the transfer material, and the toner development is carried by the transfer means 45 from a paper feeding portion (not shown) between the photosensitive body 41 and the transfer means 45 and in synchronism with the rotation of the photosensitive body 41. The images are sequentially transferred to the P surface. The transfer material P that has received the image transfer is separated from the surface of the photoconductor 41, and is transferred to the image fixing unit 4.
The image is fixed to the image receiving device 8 and is printed out as a copy. The surface of the photoconductor 41 after the image transfer is cleaned by the cleaning unit 46 to remove the residual toner after transfer, and is repeatedly used for image formation.

As the uniform charging means 42 for the photoconductor 41,
Corona charging devices are generally widely used. Further, also in the transfer device 45, corona transfer means is widely and generally used. The electrophotographic apparatus is configured by integrally combining a plurality of constituent elements such as the photoconductor 41, the developing unit 44, and the cleaning unit 46 described above as an apparatus unit, and this unit can be detachably attached to the apparatus main body. You may comprise. For example, the photoconductor 41 and the cleaning unit 4
6 and 6 may be integrated into a unit of a single apparatus, and may be detachable by using a guide means such as a rail of the apparatus main body. At this time, the above device unit may be provided with the charging means 42 and / or the developing means 44.

When the electrophotographic apparatus is used as a copying machine or a printer, the optical image exposure L converts the reflected light from the original document, the transmitted light or the original document into a signal, and scans and emits a laser beam by this signal. The diode array or the liquid crystal shutter array is driven.
Further, when used as a printer for a facsimile, the light image exposure L becomes an exposure for printing the received data. FIG. 5 is a block diagram showing an example of this case.

In FIG. 5, the controller 51 controls the image reading section 50 and the printer 59. The entire controller 51 is controlled by the CPU 57.
The read data from the image reading unit is sent to the transmission circuit 53.
Sent to the other station through. The data received from the partner station is sent to the printer 59 through the receiving circuit 52. The image memory 56 stores predetermined image data. The printer controller 58 controls the printer 59. 54 is a telephone.

The image received from the line 55 (image information from the remote terminal connected via the line) is demodulated by the receiving circuit 52, and then the image information is decoded by the CPU 57, and the images are sequentially displayed. It is stored in the memory 56.
When an image for at least one page is stored in the image memory 56, the image of that page is recorded. The CPU 57 reads out the image information for one page from the image memory 56 and sends the decoded image information for one page to the printer controller 58. The printer controller 58 is a CP
When the image information for one page is received from U57, the printer 59 is controlled to record the image information for the page. The CPU 57 is receiving the next page during recording by the printer 59. As described above, an electrophotographic apparatus equipped with the developer carrying member of the present invention can be used as a printer to receive and record images.

[0038]

EXAMPLES The present invention will be described in more detail based on the following examples. <Example 1> Formulation of Dispersion A -Phenol resin 100 parts-Crystalline graphite 75 parts-Carbon black 75 parts-Methanol 100 parts-Isopropyl alcohol 650 parts The above materials were dispersed at room temperature for 5 hours using a sand mill. It was After dispersion, the dispersion was measured with a B-type viscometer to find a viscosity of 120 (cp). Further, after adding 500 parts of isopropyl alcohol, dispersion is carried out for 1 hour, and this dispersion is designated as (A).

Formulation of Dispersion B -Phenol resin 100 parts-Crystalline graphite 40 parts-Carbon black 10 parts-Methanol 100 parts-Isopropyl alcohol 150 parts The above materials were dispersed at room temperature for 5 hours using a sand mill. After dispersion, the dispersion was measured with a B-type viscometer to find that the viscosity was 75 (cp). Furthermore, after adding 100 parts of isopropyl alcohol, dispersion is carried out for 1 hour, and this dispersion is designated as (B).

An aluminum cylindrical tube prepared by drawing was prepared, and spray coating was carried out while moving the spray gun at a constant speed while placing it on a turntable and rotating it to obtain a uniform coating film according to the following conditions. Obtained. First,
Coating was performed using the dispersion liquid (B) under the condition that the film thickness after drying was 5 μm. Next, the dispersion (A) was used in a state where the film was dried, and coating was performed so that the thickness of the dried dispersion (A) layer was 5 μm. After coating, the coated film was dried and cured at 150 ° C. for 20 minutes in an oven dryer to complete the developer carrying member (developing sleeve) of this example.

Next, this developing sleeve was incorporated into a developing device, and an image forming test was conducted using the following magnetic toner. Toner composition -Styrene-acrylic resin 100 parts-Magnetite 50 parts-Negative charge control agent 2 parts-Low molecular weight polypropylene 3 parts The above materials are kneaded by a general dry toner manufacturing method, pulverized and classified, and weighted. Average particle size (D4) = 12.0
Number of particles having a particle size of μm and a particle size of 6.35 μm or less =
A toner having a particle size distribution of 25.3% and a weight percentage of particles having a particle size of 20.2 μm or more = 1.8% was obtained. still,
The particle size distribution was measured using Coulter Counter TA-II type. To this toner, 0.4% of colloidal silica was externally added and used.

Canon LPB A406 for image output
Was used. Further, the cartridge is an EPS cartridge for the same machine with some modifications (the developing sleeve prepared in this embodiment can be mounted, and the distance between the sleeve and the drum is set to a constant distance regardless of the coating film thickness). And a stirring mechanism for making the circulation of the toner in the developing device hopper more uniform). The toner of this embodiment is packed in a 300 g cartridge, and about 3,500 sheets are intermittently discharged (1 minute per minute) until the remaining amount of toner reaches 10 g.
An image output durability test was performed. Image is 24 ℃, 6
The test was performed in a normal temperature and normal humidity environment of 5% RH and a low humidity environment of 20 ° C. and 10% RH. The change in image density at this time is shown in FIG. The image density was evaluated using both a square solid black image of 5 mm × 5 mm (5-sided density) and a solid black density on the entire surface.

Comparative Example 1 A developing sleeve was prepared in the same manner as in Example 1 except that the dispersion liquid (A) was used and the resin layer had a thickness of 10 μm. An image output test was conducted. The change in image density at this time is shown in FIG.

Comparative Example 2 By the same method as in Comparative Example 1, a developing sleeve was prepared using only the dispersion liquid (B), and the same image development test as in Example 1 was conducted. The change in image density at this time is shown in FIG.

<Example 2> Formulation of Dispersion (C) -Phenol resin 100 parts-Crystalline graphite 75 parts-Carbon black 50 parts-Methanol 100 parts-Isopropyl alcohol 675 parts The above materials were the same as in Example 1. After dispersion by the method, isopropyl alcohol was further added to carry out dispersion to prepare a dispersion liquid (C) having a solid content concentration of 22.5%.

Formulation of Dispersion (D) : Phenol resin 100 parts: Crystalline graphite 15 parts Carbon black 15 parts Methanol 100 parts Isopropyl alcohol 30 parts The above materials were dispersed in the same manner as in Example 1. Then, isopropyl alcohol was further added and dispersed to prepare a dispersion liquid (D) having a solid content concentration of 33%.

The drawn aluminum tube used in Example 1 was blasted with alundum alumina abrasive grains # 100. The center line average roughness (Ra) at this time is
When measured with a surface roughness meter SE-30H (manufactured by Kosaka Laboratory), it was 2.5 μm. Next, the same method as in Example 1 was applied except that the dispersion liquid (D) and the dispersion liquid (C) were applied to the blasted aluminum cylindrical tube so as to have a film thickness of 5 μm and 3 μm, respectively. Thus, the developing sleeve of this example was prepared.

Next, using this developing sleeve, an image output test was conducted in the same manner as in Example 1 to evaluate the image. However, the toner used had the following composition. Toner composition -Styrene-acrylic resin 100 parts-Magnetite 80 parts-Negative charge control agent 3 parts-Low molecular weight polypropylene 4 parts A toner was prepared in the same manner as in Example 1 and the particle size distribution was measured. Average particle size (D4) = 7.5
(Μm), the number percentage of particles having a particle size of 4.0 μm or less = 15.8%, and the weight percentage of particles having a particle size of 12.7 μm or more = 1.5% were obtained. To this toner,
Colloidal silica 0.9% was used as an external additive.

For image formation, LBP A406 manufactured by Canon Inc. was used as in Example 1. As the cartridge, a modified machine similar to that of Example 1 was used except that an EPS cartridge for the same machine was equipped with an elastic blade as shown in FIG. FIG. 9 shows the change in the density of the image output durability.

<Comparative Example 3> In the same manner as in Example 1,
Using only the dispersion liquid (D), a developing sleeve was prepared so that the resin layer had a film thickness of 8 μm, and the same image forming test was conducted. The change in image density at this time is shown in FIG.

<Example 3> Formulation of dispersion liquid (E) -phenol resin 100 parts-Crystalline graphite 140 parts-Carbon black 60 parts-Methanol 100 parts-Isopropyl alcohol 600 parts Dispersion liquid (F) formulation -phenol resin 100 parts-Crystalline graphite 70 parts-Carbon black 30 parts-Methanol 100 parts-Isopropyl alcohol 300 parts Dispersion (G) formulation -Phenolic resin 100 parts-Crystalline graphite 35 parts-Carbon black 15 parts-Methanol 100 parts- Isopropyl alcohol 100 parts

The above materials were dispersed in the same manner as in Example 1, then diluted with isopropyl alcohol and dispersed,
The solid contents of the dispersion liquid (E), the dispersion liquid (F) and the dispersion liquid (G) were adjusted to be 15%, 27.5% and 32.5%, respectively. Next, dispersion liquid (G) and dispersion liquid (F), respectively.
Then, the dispersion liquid (E) was coated in the same manner as in Example 1 so that each film thickness was 3 μm, and a developing sleeve was prepared.

The developing sleeve thus obtained was subjected to an image forming test in the same manner as in Example 1. However, the toner used had the following composition. Toner composition -Styrene-acrylic resin 100 parts-Magnetite 55 parts-Negative charge control agent 3 parts-Low molecular weight polypropylene 4 parts A toner was prepared in the same manner as in Example 1 and the particle size distribution was measured. Particle size (D4) = 10.3
A toner having a particle size distribution of (μm), number percentage of particles having a particle size of 6.35 μm or less = 27.3%, and weight percentage of particles having a particle size of 16.0 μm or more = 2.8% was obtained. 0.4% of colloidal silica was externally added to this toner and used as the toner of this example. Example 1
In the same manner as above, evaluation was performed using LBP A406 manufactured by Canon Inc. FIG. 11 shows the change in the image development durability density.

<Comparative Example 4> In the same manner as in Example 1,
A developing sleeve was prepared using only the dispersion liquid (F) so as to have a film thickness of 9 μm, and the same image forming test was conducted.
FIG. 12 shows a change in image density when an image is output.

As shown above, when the developing sleeves after the endurance of all Examples and Comparative Examples were observed, the resin films of the samples of Comparative Examples 1 and 4 were scraped and the surface of the aluminum cylindrical tube appeared. . Further, the samples of the examples were examined for ghost images at the time of endurance, but all were at a practical level, and there were no images that pose a problem.

[0056]

As described above, according to the developer carrying member of the present invention, a developer carrying member which can obtain a uniform, high-density image without unevenness or density through durable image formation, and the same can be obtained. Various devices using can be provided. As described above, according to the developer carrier of the present invention and various apparatuses using the same, since the developer placed on the developer carrier has a stable and suitable electric charge, uniform and uneven density can be obtained. A stable, high-quality image can be obtained. Further, according to the developer carrying member of the present invention and various apparatuses using the same, a clear image without scattering of characters, thickening and thinning, etc. can be provided. Furthermore, according to the developer carrying member of the present invention and various apparatuses using the same, a stable and high-quality image that does not cause a decrease in image density or uneven density is obtained even when repeatedly used,
Further, it is possible to obtain stable image quality that is not affected by environmental changes.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a developing device using a developer carrier of the present invention.

FIG. 2 is a diagram showing an example of a developing device using the developer carrier of the present invention.

FIG. 3 is a diagram showing an example of a developing device using the developer carrier of the present invention.

FIG. 4 is a schematic view of an electrophotographic apparatus using the developer carrier of the present invention.

FIG. 5 is a block diagram showing an example of a facsimile of the present invention.

FIG. 6 is a graph showing evaluation results of Example 1.

7 is a graph showing the evaluation results of Comparative Example 1. FIG.

FIG. 8 is a graph showing the evaluation results of Comparative Example 2.

9 is a graph showing evaluation results of Example 2. FIG.

FIG. 10 is a graph showing the evaluation results of Comparative Example 3.

11 is a graph showing evaluation results of Example 4. FIG.

FIG. 12 is a graph showing the evaluation results of a comparative example.

[Explanation of symbols]

 1, 41 ... Drum type photoconductor 2 ... Regulation blade 3 ... Hopper 4 ... Toner 5 ... Magnet 6, 7 ... Resin layer 8 ... Development sleeve 9 ... Power supply 20 ... Elastic plate D ... Development part L ... Optical image exposure 41a ... Shaft 42 ... Charging means 43 ... Exposure section 44 ... Developing means 45 ... Transfer means 46 ... Cleaning means 48 ... Fixing means 54 ... Telephone 55 ... Line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michiko Orihara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. A developer carrier having a resin layer in which a conductive substance such as carbon is dispersed on a metal substrate, wherein the resin layer is a surface layer containing a large amount of a conductive substance such as carbon. And a layered coating comprising at least two lower layers containing less conductive material such as carbon than the surface layer. 2. The latent image formed on the image carrier is formed according to claim 1.
A developing device carrying the developer carried by the developer carrying body described in 1, and carrying out development using the carried developer. 3. An electron comprising at least the developer carrier, the charging means, the developing means and the cleaning means of claim 1, which are integrally supported, and which is a detachable unit in the developing device main body. Photographic equipment unit. 4. An electrophotographic apparatus comprising the developer carrying member according to claim 1, a developing means using the same, a latent image forming means, and a means for transferring the developed image to a transfer material. 5. A facsimile comprising the electrophotographic apparatus according to claim 4 and a receiving unit for receiving image information from a remote terminal.