JP3757683B2 - Cylindrical electrophotographic photoreceptor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylindrical electrophotographic photosensitive member, more specifically, a cylinder that is equipped with a flange having excellent roundness, has excellent rotational accuracy, and can obtain a beautiful and faithful image without color misregistration even in color printing. The present invention relates to a type electrophotographic photosensitive member.
[0002]
[Prior art]
In recent years, electrophotographic technology has been widely used not only in the field of copiers but also in the fields of various printers and facsimiles because it can provide images with immediacy, high quality and high storage stability. .
This electrophotographic process basically includes charging a photosensitive member, forming an electrostatic latent image by image exposure, developing the latent image with toner, and transferring the toner image to paper (in some cases, via a transfer member in the middle). And an image forming process by fixing.
A photoreceptor that is the core of electrophotographic technology is used by attaching a flange to the end of a cylindrical photosensitive drum on which a photosensitive layer such as a charge generation layer or a charge transport layer is formed.
As shown in FIG. 4, the flange 3 of the electrophotographic photosensitive member is formed with a drum fitting portion 4 fitted to the end portion of the photosensitive drum 2 on one end side of the substantially cylindrical body, and the other end side as required. A gear 5 for transmitting a rotational driving force is formed.
[0003]
Therefore, the roundness is important for a cylindrical electrophotographic photosensitive member. When the roundness is lowered, the running speed of the photosensitive drum peripheral surface is not constant, and the image is distorted, or color misregistration is performed in color printing. Occurs, and a beautiful and faithful image cannot be obtained.
In order to increase the roundness of the photosensitive drum, the roundness of the flange fitted to both ends of the photosensitive drum is important, and it is necessary to form a flange having a high roundness without distortion.
The flange is generally formed by injection molding using a thermoplastic resin. In order to improve uniformity, the flange is formed using about 3 to 12 pin gates 7 as shown in FIG.
[0004]
However, there has been a problem that high dimensional accuracy cannot be obtained even when trying to perform uniform injection molding using many pin gates.
As a result of extensive studies by the present inventor in order to find out the cause, it has been found that there is a problem in the mounting position of the pin gate.
In other words, conventionally, the pin gates 7 and 7 are provided on the intermediate wall 6 for receiving the rotation shaft. However, when a large number of pin gates are formed on the intermediate wall 6 and injection molding is performed, the state of the thermoplastic resin is integrated. It was found that local non-uniformity occurred and this caused distortion.
[0005]
[Problems to be solved by the invention]
The present invention provides a cylindrical electrophotographic photosensitive member capable of forming a beautiful and faithful image with high roundness and no color shift even in color printing by mounting a flange having no distortion and high roundness. Provide the body.
[0006]
[Means for Solving the Problems]
The present invention has been made as a result of intensive studies in order to achieve such an object. In a cylindrical electrophotographic photosensitive member in which a flange is fitted to an end of a cylindrical photosensitive drum, the photosensitive member is exposed on one side. A cylindrical portion that fits into the drum, a hub sleeve that is coaxially formed in the cylindrical portion at the center thereof, and an annular rib that is coaxially formed between the cylindrical portion and the hub sleeve A cylindrical electronic device characterized in that a cylindrical portion, a hub sleeve and an annular rib are connected by an intermediate wall, and a flange formed by arranging a plurality of pin gates at the end of the annular rib is mounted. A photographic photoreceptor is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the cylindrical electrophotographic photoreceptor 1 of the present invention has a flange 3 attached to the end of a photosensitive drum 2 having a photosensitive layer formed on the outer surface.
The material of the photosensitive drum 2 is not particularly limited, but a photosensitive layer is formed on the surface of a cylindrical substrate, and the substrate can be formed into a cylindrical shape with a high dimensional accuracy and a heat-resistant material.
Specifically, synthetic resins such as glass, ceramics, polyethylene, polypropylene, polycarbonate, and polyamide, and metals such as copper and aluminum can be used. Of these, aluminum is preferable.
When a non-conductor is used, it is common to conduct a conductive material by blending a conductive powder or to conduct a conductive surface by metal vapor deposition.
[0008]
Hereinafter, the manufacturing method will be described in the case of using aluminum as the substrate. After processing aluminum or aluminum alloy such as A1050, A3003, A6063, etc. into a cylindrical shape by the porthole method, mandrel method, etc., the predetermined thickness, length, outer In order to obtain a cylindrical cylinder having a diameter, processing such as drawing or cutting is performed. In many cases, the substrate subjected to the processing is usually anodized.
[0009]
As conditions for the anodizing treatment, conventionally known conditions are arbitrarily selected and adopted. Specifically, sulfuric acid, oxalic acid, phosphoric acid, or the like can be used as the electrolytic solution for anodizing treatment. Of these electrolytes, sulfuric acid is preferred. In the case of sulfuric acid alumite treatment, the sulfuric acid concentration in the electrolytic solution is preferably selected from the range of 100 to 300 g / L, and the temperature of the electrolytic solution is selected from the range of 10 to 30 ° C. The energization time is appropriately determined depending on the thickness of the target anodized film. The thickness of the anodic oxide coating is suitably in the range of 2 to 15 μm.
[0010]
The anodized substrate is subjected to sealing treatment. As the sealing treatment solution, a conventional sealing treatment solution such as a solution containing nickel ions (for example, a solution containing nickel acetate or a solution containing nickel fluoride) can be used.
A photosensitive layer is formed on the sealed substrate. The photosensitive layer includes a charge generation layer containing a charge generation material and a charge transport layer laminated in this order, a reverse layer, or a so-called single layer type in which charge generation material particles are dispersed in a charge transport medium. Although it can be used, a multilayer photosensitive layer having a charge generation layer and a charge transport layer is preferred.
[0011]
Charge generation materials include selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, other inorganic photoconductors, azo pigments such as Sudan Red, Diane Blue, and Dienas Green B, disazo pigments, argol yellow, and pyrenequinone And quinocyanine pigments such as quinocyanine pigments, quinocyanine pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments such as Indian First Orange toner, phthalocyanine pigments such as copper phthalocyanine, quinacridone pigments, pyrylium salts, and azurenium salts. Of these, oxytitanium phthalocyanine is preferable.
[0012]
Charge transport materials include polyaromatic compounds such as anthracene, pyrene, phenanthrene, coronene or indole, carbazole, oxazole, isoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline, thiadiazole, triazole in the main chain or side chain Examples thereof include compounds having a skeleton of a nitrogen-containing cyclic compound such as, and hole transport materials such as hydrazone compounds.
[0013]
Examples of the binder resin for forming the photosensitive coating film include polycarbonate, polyarylate, polystyrene, polymethacrylic acid esters, styrene-methyl methacrylate copolymer, polyester, styrene-acrylonitrile copolymer, polysulfone, polyvinyl acetate, poly Examples include acrylonitrile, polyvinyl butyral, polyvinyl pyrrolidone, methyl cellulose, hydroxymethyl cellulose, and cellulose esters.
[0014]
As the coating solvent, a solvent having high volatility and a vapor density larger than that of air is preferably used. For example, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, 4-methoxy-4-methyl-2-pentanone, dimethoxymethane, dimethoxyethane, 2,4-pentadione, anisole, methyl 3-oxobutanoate, monochlorobenzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, Examples thereof include methyl cellosolve, ethyl cellosolve, and methyl cellosolve acetate.
[0015]
The coating solution for the photosensitive material in the case of producing a single layer type electrophotographic photosensitive member is prepared by mixing the charge generating substance, the charge transporting substance, the binder resin and the coating solvent. The photosensitive material coating solution used in the production of the laminated electrophotographic photosensitive member includes a charge generating layer coating solution comprising the charge generating material, a binder resin and a coating solvent, and the charge transporting material. A charge transport layer coating solution comprising a binder resin and a coating solvent is prepared separately.
[0016]
The concentration of each component in the coating solution is appropriately selected according to a known method. The concentration of the solid content is mainly determined according to the film thickness of the layer to be formed. In the case of a coating solution for producing a single-layer type electrophotographic photosensitive member, a laminated type electrophotographic photosensitive member is produced. In the case of the coating liquid for the charge transport layer, the amount is adjusted to 40% by weight or less, preferably 10 to 35% by weight. In the case of these coating solutions, the viscosity is 50 to 300 cps, preferably 70 to 250 cps, and the dry film thickness is 15 to 40 μm.
[0017]
In the case of a coating solution for a charge generation layer, the solid concentration is 15% by weight or less, preferably 1 to 10% by weight, and the dry film thickness is usually 0.1 to 1 μm. .
The above coating is usually performed by dip coating, that is, a method in which the cylindrical substrate is vertically lowered and immersed in the coating solution in a dipping bath in which the coating solution overflows, and then the cylindrical substrate is vertically lifted and pulled up. Is called.
The photosensitive drum 2 thus obtained is provided with flanges 3 at both ends thereof.
[0018]
As shown in FIG. 1, the flange 3 used in the present invention is formed of a substantially cylindrical body.
The flange 3 is made of a material having rigidity and excellent dimensional accuracy, and a synthetic resin such as polyamide, polycarbonate, polyphenylene ether, ABS resin, polyacetal or polyphenylene sulfide, or a metal such as copper or aluminum is used.
When a defective conductor such as a synthetic resin is used, it is generally used by making it conductive by blending conductive powder such as metal powder, carbon black, and graphite. It is also possible to use a conductive element that is molded with a synthetic resin of a defective conductor and that electrically connects the photosensitive drum 2 and the rotating shaft separately.
[0019]
In order to improve the physical properties of synthetic resins, two or more of these resins may be used in combination, and may be used in combination with other materials as long as the properties are not impaired. In this case, it can be used in combination with a resin containing reinforcing fibers such as glass fibers, carbon fibers, and alumina fibers or bead-like reinforcing materials. The reinforcing fiber and the bead-like reinforcing material may be used alone or in combination of two or more, but the reinforcing fiber mainly composed of glass fiber is advantageous in terms of cost.
[0020]
As shown in FIG. 1, the flange 3 is formed in a substantially cylindrical shape, and a cylindrical portion 4 that fits on the photosensitive drum 2 is formed on one side, and a rib 8 protrudes in the circumferential direction on the opposite side. It serves as a stopper that determines the drum stop position.
Generally, at least one end of the photosensitive drum 2 is loaded with a flange having a gear for rotational driving. When the geared flange 3 is formed, the opposite side of the cylindrical body 4 is formed as shown in FIG. A gear 5 is formed on the outer periphery of the cylinder.
A sleeve 10 for forming a hub 9 is formed at the center of the cylindrical portion 4 and is connected by an intermediate wall 6.
[0021]
In the flange 3 of the present invention, an annular rib 11 is formed coaxially with the cylindrical portion 4 on the intermediate wall 6 between the cylindrical portion 4 and the sleeve 10.
The height of the annular rib 11 is 2 to 20 times, preferably 5 to 10 times the wall thickness of the intermediate wall 6, and the rib width is 0.5 to 2 times the wall thickness of the intermediate wall 6. Preferably 0.8 times to 1.2 times is desirable, and a plurality of pin gates 7 are disposed at the end of the annular rib 11 as shown in FIGS.
The number of pin gates 7 is not particularly limited, but is generally 3 or more, preferably 3-12.
[0022]
Further, a second annular rib 12 having the same diameter as the annular rib 11 is projected on the back surface of the projecting portion of the annular rib 11 of the intermediate wall 6, that is, on the opposite surface of the intermediate wall 6 on which the annular rib 11 is projected. It is desirable to install.
The height of the second annular rib 12 is 2 to 20 times, preferably 5 to 10 times the wall thickness of the intermediate wall 6, and the rib width is 0.5 to 2 times the wall thickness of the intermediate wall 6. It is desirable to make it twice, preferably 0.8 times to 1.2 times.
By forming the annular rib 11 on the intermediate wall 6 and providing a pin gate on its end face, variation in the orientation of the resin is suppressed, and the weld state or the cooling and solidifying state of the resin junction is made uniform. 3 is reduced, and the flange 3 maintains roundness.
[0023]
【The invention's effect】
Since the present invention does not cause distortion of the flange and maintains high roundness, the photosensitive drum loaded with the flange of the present invention has excellent roundness, and is beautiful and faithful without color misregistration even in color printing. Can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an example of a flange of the present invention. FIG. 2 is a longitudinal sectional view of a flange with a gear of the present invention. FIG. 3 is a perspective view of the flange of FIG. [Explanation of symbols]
1. 1. Cylindrical electrophotographic photosensitive member 2. Photosensitive drum Flange 4. 5. tubular portion Intermediate wall 7. Pin gate 9. Hub 10. Sleeve 11. Annular rib 12. Second annular rib

Claims (3)

In a cylindrical electrophotographic photosensitive member in which a flange is fitted to the end of a cylindrical photosensitive drum, a cylindrical portion that is fitted to the photosensitive drum on one side and a cylindrical portion that is coaxially formed at the center thereof. A hub sleeve, and an annular rib formed coaxially between the tubular portion and the hub sleeve. The tubular portion, the hub sleeve and the annular rib are connected by an intermediate wall. A cylindrical electrophotographic photosensitive member comprising a flange formed with a plurality of pin gates disposed at an end thereof. 2. The cylindrical electrophotographic photosensitive member according to claim 1, wherein a second annular rib having the same diameter as the annular rib is formed on the back surface of the intermediate wall where the annular rib of the flange is continuously provided. 3. The cylindrical electrophotographic photosensitive member according to claim 1, wherein a rotation driving gear is formed at an end of the flange opposite to the cylindrical portion.

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