JP2003262966A - Organic photoreceptor, manufacture method of organic photoreceptor, cleaning method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic photoreceptor in which the problem of a faulty cleaning caused by a fault part of the end of a coating layer caused after removing the coating layer of an unnecessary part such as a liquid bank part at the lower end of the cylindrical organic photoreceptor is solved, and to provide a manufacture method of the organic photoreceptor, and to provide a cleaning method and an image forming apparatus using the organic photoreceptor. <P>SOLUTION: The organic photoreceptor having the coating layer including a photoreceptive layer on cylindrical base substance, is characterized in that the locus of the end of the coating layer is meandered or inclined in the circumferential direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic photoconductor used in an electrophotographic image forming apparatus, a method for manufacturing the organic photoconductor, a cleaning method, and an image forming apparatus.

[0002]

2. Description of the Related Art Cylindrical organic photoconductors (hereinafter also referred to as "cylindrical photoconductors") are generally manufactured by coating a cylindrical substrate with a solution such as a photosensitive layer coating solution by a dip coating method or the like and then drying it. However, during the coating and drying process, a liquid pool is generated at the lower end of the cylindrical substrate due to the flow of the coating liquid. If this is left as it is and dried, a thick film portion of a liquid pool is formed at the lower end portion of the cylindrical photoreceptor. When such a cylindrical photoreceptor is used in an image forming apparatus, film peeling may occur from the liquid pool, cleaning failure may occur, and image defects may easily occur. Therefore, there has been proposed a method of removing the lower end portion of the cylindrical photosensitive member (the portion unnecessary for image formation) including the liquid pool portion.

As a method for removing the coating layer on the lower end of the cylindrical photoreceptor, a method of immersing the lower end of the cylindrical photoreceptor in a solvent and ultrasonically vibrating it (Japanese Patent Laid-Open No. 63-311357) or rubbing with a brush is used. Method (JP-A-3-60782, JP-A-4-141663, JP-A-5-142789)
No. 10-207084 and No. 11-184.
No. 100, No. 11-194509, etc.), there is also a removing method using a tape. For example, a method of sequentially unwinding a tape made of a heat-fusion type non-woven fabric, supplying a solvent to this tape, and then contacting this tape with a cylindrical photosensitive member to remove the photosensitive layer (Japanese Patent Publication No. 4-65376).
Alternatively, a method of unwinding a tape made of a twill fabric impregnated with a solvent and then contacting the tape with a photoconductor drum to remove the tape (Japanese Patent Laid-Open No. 6-138670) is used. Method using tape (JP-A-9-28)
No. 1725) is known.

However, when the cylindrical photosensitive member manufactured as described above is loaded into an image forming apparatus and a performance test is carried out, a cleaning failure such as toner slippage often occurs at the end of the image, and the image is There were cases where defects occurred. Upon investigating the cause of this, the cleaning blade receives a strong cutting force at the cut portion of the coating layer at the lower end of the removed cylindrical photosensitive member, and the wear and cutting of the cleaning blade are large at this portion, resulting in poor cleaning. It was confirmed that an image defect occurred at the edge of the image.

This phenomenon is more likely to occur when the cleaning blade is worn or cut at the tomographic portion in the case of a cylindrical photosensitive body containing inorganic fine particles in the photosensitive layer or the intermediate layer or a cylindrical photosensitive body using a thermosetting resin. A phenomenon that appears largely and in which cleaning failure easily occurs can be seen.

[0006]

The present invention has been made to solve the above problems. That is, an organic photoconductor that solves the problem of poor cleaning caused by a faulty portion of the end portion of the coating layer after removing the coating layer in an unnecessary portion such as a liquid pool at the lower end portion of the cylindrical organic photoreceptor, and the organic photoreceptor. And a cleaning method and an image forming apparatus using the organic photoconductor.

[0007]

The above object of the present invention can be achieved by adopting any one of the following configurations.

1. An organic photoreceptor having a coating layer including a photosensitive layer on a cylindrical substrate, wherein an end locus of the coating layer meanders or inclines in the circumferential direction.

2. The meandering width or inclination width of the end locus is
2. The organic photoreceptor according to the item 1, which has a length of 0.5 mm or more and 10 mm or less.

3. 3. The organic photoreceptor as described in 1 or 2 above, wherein the surface layer of the organic photoreceptor contains inorganic fine particles.

4. In a method for producing an organic photoreceptor having a coating layer containing at least a photosensitive layer on a cylindrical substrate, a rubbing member is formed by coating the coating layer on the cylindrical substrate and impregnating the coating layer end with a solvent. And removing the coating layer end portion by rotating the cylindrical base body relative to the rubbing member relative to the rubbing member and moving the cylindrical base body in the central axis direction at the same time. A method of manufacturing an organic photoreceptor, which comprises forming an end locus of a coating layer meandering or sloping in a circumferential direction.

5. A cleaning blade is used to remove residual toner on an organic photoreceptor having a coating layer including a photosensitive layer on a cylindrical substrate, and the end locus of the coating layer meanders or is inclined in the circumferential direction. Characteristic toner cleaning method.

6. An image forming apparatus using the cleaning method described in 5 above.

The present invention will be described in detail below. The organic photoreceptor of the present invention is characterized in that the end portion loci of the coating layer in the circumferential direction meander or incline. That is, the present invention is characterized in that the end locus of the coating layer formed on the cylindrical substrate from which unnecessary portions are removed is meandering or inclined in the circumferential direction. As a result, with the rotation of the cylindrical photosensitive member, the contact position between the cleaning blade and the end section of the coating layer constantly fluctuates, and the cleaning blade is not worn or cut at the contact position, resulting in poor cleaning or It is possible to prevent the occurrence of image defects.

The fact that the end locus of the coating layer meanders or is inclined in the circumferential direction will be described with reference to FIG.
The coating layer refers to all layers that are coated on the cylindrical conductive substrate as necessary, such as the charge generation layer of the function-separated type photoreceptor, the photosensitive layer including the charge transport layer, the intermediate layer, and the surface protective layer. Point to.

The cylindrical photosensitive member 3 has a shape as shown in the perspective view of FIG. 1A, and a photosensitive layer is formed on the surface of the conductive substrate 1 having a drum shape, and if necessary, an intermediate layer or a surface protective layer. A coating layer 2 such as is coated. It is desirable that at least one of the coating layers on the cylindrical photoreceptor is completely removed, but the curable intermediate layer or the like may remain.

Here, the meaning of the end locus meandering or inclining in the circumferential direction will be described by way of example. Figure 1
(B) shows an end locus of the coating layer after removing the coating layer of the liquid pool portion at the lower end of the cylindrical photoreceptor. The solid line c in FIG. 1 (b) indicates the circumferential line of the circumferential surface perpendicular to the central axis of the cylindrical substrate. The end locus achieved by the heretofore known coating film removing method is formed on this circumference. However, the end locus of the coating layer shown by the solid line and the broken line p indicates an inclined line that is not parallel to the circumferential surface perpendicular to the central axis, and the end locus p formed on such an inclined line is referred to. It is said that the end locus of the coating layer is inclined in the circumferential direction.

FIG. 2 shows examples of various coating layer end loci.
2 (a) and 2 (b) show inclined end loci (p, q), and FIGS. 2 (c), (d) and (e) show meandering end loci (r, s, t). Show. In the present invention, it may meander in a comb shape as shown in FIG.

An example in which the end locus of the coating layer meanders or inclines in the circumferential direction will be described with reference to the development view of FIG. Figure 3
In (a), the circumferential line of the circumferential surface perpendicular to the central axis of the cylindrical substrate is represented by a horizontal line with a being the circumferential line. The points as and ae on the horizontal line indicate the same points on the circumferential line. An example of the end locus of the coating layer tilted in the direction of the central axis of the cylindrical substrate with respect to the circumferential line a is the dashed-dotted lines p and q in FIGS. 3A and 3B. 3 (c), (d), and (e), the end loci indicated by the wavy one-dot chain lines of r, s, and t meander in the circumferential direction. That is, the end locus of the coating layer meandering or sloping in the circumferential direction of the present invention does not need to be in one direction, and there may be a discontinuity in the middle.

The meandering width or inclination width of the end locus is shown in FIG.
Explaining (a) to (e) as an example, the maximum vertical interval due to the meandering or inclination of the end locus, that is, the interval indicated by h in the figure is shown. In the present invention, the maximum meandering width or inclination width is shown. The value is preferably 0.5 mm or more and 10 mm or less. Furthermore, 2 mm or more and 8 mm or less are more preferable. 0.5 mm
When it is less than 10 mm, the effect of preventing abrasion and cutting due to contact between the cleaning blade and the end locus is small, and the effect of preventing defective cleaning is small. On the other hand, when it is more than 10 mm, the image forming width of the organic photoreceptor becomes narrow, It becomes impossible to secure an effective image forming area.

In the cylindrical photosensitive member having the end locus of the coating layer of the present invention as described above, even if the toner is removed by using the cleaning blade, the rotation of the cylindrical photosensitive member causes the cleaning blade and the coating layer to be separated from each other. The contact position of the end section constantly changes, and the wear or cutting of the cleaning blade does not occur at the corresponding contact position, and it is possible to prevent defective cleaning or defective images.

On the other hand, a cleaning device is known in which the length of the cleaning blade is relatively short, and the end portion of the cleaning blade has a sealing member made of maltoprene or the like (for example, Japanese Patent Laid-Open No. 05-61390). There is a case where the end fault of the contact layer comes into contact with the seal member, but even in such a case, if the end fault of the coating layer always contacts at the same position, the seal member naturally wears and cuts. Even in such a case, the same effect as that described for the cleaning blade is exhibited.

Next, a method of forming an end locus of the coating layer meandering or sloping in the circumferential direction will be described.

The method of removing the coating layer to form the end locus of the coating layer is not particularly limited. Less than,
A method of forming the end locus of the coating layer of the present invention will be described by taking a brush removal method as an example.

Method of Removing Coating Layer by Brush FIG. 4 is a sectional view of the coating layer removing apparatus by brush. In the figure, 3 is a cylindrical photoreceptor having a coating layer formed on its surface. This cylindrical photosensitive member is gripped by the conveying means 47 so as to be movable up and down (from a coating layer coating step (not shown),
The cylindrical photoconductor is conveyed) and is brought into contact with a rubbing member 55 provided in a coating layer removing stand (coating layer removing means) 54 of the coating layer removing device 50. The coating layer removing base 54 is also provided with a sponge-shaped base holding member 541, and the cylindrical photosensitive member 3 is sandwiched between the base holding member 541 and the rubbing member 55 on the coating layer removing base 54. The coating layer removing table 54 is designed to be rotatable by driving a motor or the like. The cylindrical photoconductor 3 is installed on the coating layer removing table 54 by the conveying means 47 having a gripping means (O-ring chuck, air picker chuck, etc.) for gripping the inside of the base body, and the lower end of the cylindrical photoconductor 3 is rubbed. It is brought into contact with the member 55 (FIG. 4A). At this time, the coating layer removing table 54 is a solvent tank 51 as a cleaning means.
It is out of the liquid surface. With the residual solvent in the end coating layer of the cylindrical photosensitive member being 60% by mass or less, the coating layer removing table 54 rotates (the cylindrical photosensitive member may be rotated. The cylindrical photoconductor is relatively rotated), and at the same time, the cylindrical photoconductor is moved up and down (the coating layer removing table 54 is moved up and down by the rotation of the cylinder 542) to remove the coating layer at the lower end. Wipe off with the rubbing member 55. The end loci p to s of the coating layer shown in FIGS. 3A to 3D are formed by the vertical movement pattern of the coating layer removing table.

FIG. 5 is a vertical cross-sectional view of the cylindrical photoconductor 3 and the rubbing member 55 in contact with each other. The cylindrical photoconductor 3 is in contact with the brush 551 of the rubbing member. If the rubbing member 55 is located at the same position on both ends of the cylindrical photosensitive member 3 relatively, and the cylindrical photosensitive member is gradually raised at the same time as the sliding member rotates,
The end locus becomes q in FIG. 3 (b), and if the cylindrical photoconductor is moved up and down in addition to this movement, the end locus is shown in FIG. 3 (d).
S. Also, the number of the brush 551 of the rubbing member is one,
When the cylindrical photosensitive member is moved up and down by 1/2 rotation at the same time as the rotation of the rubbing member, the end locus is as shown in FIG.
When the vertical movement of the photosensitive member is repeated simultaneously with the rotation of the sliding member, the end locus is formed as shown in FIG.
It becomes r in (c).

The residual solvent in the coating layer at the start of removing the coating layer is preferably 60% by mass or less and 3% by mass or more. The residual solvent amount remains in the coating layer immediately after the coating layer is formed (when a plurality of layers are coated, immediately after the last layer is coated), with the content of the solvent content being 100% by mass. The obtained mass% is calculated.

After this wiping is completed, the cylindrical photosensitive member is lifted by the conveying means 47 (also serving as a separating means), separated from the coating layer removing table 54, and dried. In this way, a cylindrical photoreceptor having the end locus of the coating layer of the present invention is manufactured. On the other hand, the coating layer removing table 54 is immersed in the solvent 51E of the solvent tank 51, which is a cleaning means, by rotating a cylinder (moving means of the coating layer removing means) 542 that enables the coating layer removing table 54 to move up and down ( Figure 4
(B)) In the solvent tank, the ultrasonic cleaning machine and the vertical movement of the coating layer removal table by a cylinder, and the rotational movement are combined to clean the entire coating layer removal table including the rubbing member. After that, by rotating the cylinder 542 again, the cylinder 542 is lifted above the liquid surface of the solvent tank 51 to prepare for removal of the next coating layer. Further, it is preferable to install an ultrasonic transducer U in the solvent tank to enhance the cleaning efficiency of the coating layer removing means. When two or more coating layers are simultaneously removed as shown in FIG. 4, a partition plate 59 is provided between the coating layer removing means.
Is preferably provided to prevent the occurrence of defects due to bounce and the like during the removal of the coating layer of each cylindrical photoreceptor 3.

As the material of the rubbing member, there are a brush, a sponge, a cloth, a polymer fiber cloth and the like, and the brush is preferable.

Suitable materials for the brush are nylon, polyethylene, polypropylene, polyester and the like. The size of one hole for planting the brush on the coating layer removal table 54 is about 0.5 to 2 mm, and the distance between the holes is about 1 to 3 mm. The entire width of the brush is preferably used so as to correspond to the width of the coating layer to be removed.

In the present invention, the solvent-impregnated rubbing member need only carry the solvent even if the material of the rubbing member is not impregnated with the solvent. The amount of impregnation of the rubbing member is preferably 105 to 200 parts by mass, when the mass of the rubbing member during drying is 100 parts by mass.

FIG. 6 is an overall configuration diagram of the coating layer removing device 50. The coating layer removing device 50 includes a solvent tank 51, a solvent overflow chamber 52, a replenishment tank 53, and a coating layer removing table 5.
4, rubbing member 55, solvent circulation pipe 56, pump 57,
It is composed of a filter 58, a conveying means 47, and the like.

A rubbing member 55 and a substrate holding member 541 are attached to the coating layer removing base 54, and the cylindrical photosensitive member 3 is fixed at the same time by the rotation and vertical movement of the coating layer removing base 54. The coating layer at the lower end is wiped off and removed. In addition, as shown in FIG.
4 is designed to be movable in and out of the solvent tank 51 by rotation of the cylinder 542 together with the rubbing member 55 and the like.

The solvent in the solvent tank is replenished by the replenishment tank 5.
3 is constantly circulated through the solvent circulation pipe 56, and a coating layer component is removed by providing a filter in the middle of the circulation pipe so that the solvent can sufficiently wash the coating layer removing means.

The solvent used in the present invention for removal depends on the type of the coating layer, but examples thereof include ethers such as tetrahydrofuran, methanol, chloroform, methylene chloride, MEK (methyl ethyl ketone), acetone, alcohols and chlorine. There are system solvents, ketone systems and mixed solvents thereof.

The method for forming the removed end of the coating layer of the present invention is as follows.
A wiping tape removal method may be used. The wiping method using a wiping tape is a method in which the wiping tape is impregnated with a solvent that dissolves or swells the coating layer, and the wiping tape is brought into contact with the coating layer of the rotating cylindrical photoreceptor to wipe the coating layer. If the movement in the direction of the central axis of the cylindrical photoconductor is applied at the same time as the rotation of the cylindrical photoconductor, FIG.
Various patterns of the coating layer end locus of p to s in (d) can be formed.

The material for the wiping tape is preferably capable of impregnating the solvent used. The material is not particularly limited as long as it is not attacked by the solvent used and can withstand the tension during wiping. Specifically, 6
Nylon fibers, polyamide fibers such as 66 nylon fibers, polyester fibers such as polyethylene terephthalate fibers, polybutylene terephthalate fibers, acrylic fibers, vinylon fibers, vinylidene fibers, polyurethane fibers, fluorine fibers, aromatic polyamide fibers, polyethylene fibers, Synthetic fibers such as polyolefin fibers such as polypropylene fibers, regenerated fibers such as rayon fibers, semi-synthetic fibers such as acetate fibers, inorganic fibers such as carbon fibers, plant fibers such as cotton fibers and hemp fibers, animal fibers such as wool. Can be used.

The impregnating solvent used by impregnating the wiping tape varies depending on the type of the coating layer, but is not particularly limited as long as it can be dissolved or swelled and removed.
What was mentioned above can be used.

Next, the organic photoreceptor of the present invention will be described. In the present invention, the organic photoreceptor means an electrophotographic photoreceptor constituted by giving an organic compound either one of the charge generation function and the charge transport function, which is essential for the construction of the electrophotographic photoreceptor, It includes all known organic electrophotographic photoconductors such as a photoconductor composed of a known organic charge generating substance or an organic charge transporting substance, and a photoconductor comprising a polymer complex having a charge generating function and a charge transporting function.

Further, the surface layer of the present invention means a layer that is simply present on the surface in the various layer constitutions constituting the electrophotographic photosensitive member, and does not exhibit a function. That is, when the electrophotographic photoreceptor has an intermediate layer, a charge generation layer and a charge transport layer laminated in this order on a cylindrical substrate, the charge transport layer is a surface layer, and when a protective layer is further laminated. The protective layer serves as the surface layer.

The cylindrical organic photoreceptor used in the present invention will be described below. Cylindrical Substrate A cylindrical conductive substrate is used as the cylindrical substrate used in the cylindrical photoreceptor of the present invention. The cylindrical conductive substrate means a cylindrical support that needs to be capable of forming an image endlessly by being rotated, and has a straightness of 0.1 mm.
Hereinafter, a conductive substrate having a deflection of 0.1 mm or less is preferable. If the straightness and the shake range are exceeded, good image formation becomes difficult.

As the conductive material, a metal drum of aluminum, nickel or the like, a plastic drum on which aluminum, tin oxide, indium oxide or the like is deposited, or a paper / plastic drum coated with a conductive substance can be used. It is preferable that the conductive support has a specific resistance of 10 ³ Ωcm or less at room temperature.

Intermediate Layer The intermediate layer (UCL) used in the photoreceptor of the present invention is a cylindrical substrate in order to improve the adhesion between the cylindrical substrate and the photosensitive layer or to prevent the injection of charges from the cylindrical substrate. The material for the intermediate layer, which is provided between the photosensitive layers, includes a polyamide resin, a vinyl chloride resin, a vinyl acetate resin, and a copolymer resin containing two or more of the repeating units of these resins. . Among these resins, a polyamide resin is preferable as a resin that can reduce the increase in residual potential due to repeated use. The thickness of the intermediate layer using these resins is preferably 0.01 to 2.0 μm.

The intermediate layer most preferably used in the present invention is an intermediate layer using a curable metal resin obtained by thermosetting an organic metal compound such as a silane coupling agent or a titanium coupling agent. The thickness of the intermediate layer using the curable metal resin is preferably 0.01 to 2.0 μm.

Another preferable intermediate layer is a layer containing titanium oxide and a binder resin, in which titanium oxide is dispersed and applied in a binder resin solution. The thickness of the intermediate layer using titanium oxide is preferably 0.1 to 15 μm.

Photosensitive Layer The photosensitive layer structure of the cylindrical photoreceptor of the present invention may be a single-layer photosensitive layer structure in which one layer has a charge generating function and a charge transporting function on the undercoat layer. It is preferable that the function of the photosensitive layer is separated into a charge generation layer (CGL) and a charge transport layer (CTL). By adopting a constitution in which the functions are separated, the increase in residual potential due to repeated use can be controlled to be small, and other electrophotographic characteristics can be easily controlled according to the purpose. In the negative charging photoreceptor, it is preferable that a charge generation layer (CGL) is formed on the undercoat layer and a charge transport layer (CTL) is formed on the charge generation layer. In the case of the photoconductor for positive charging, the order of the layers is the reverse of that of the photoconductor for negative charging. The most preferable photosensitive layer structure of the present invention is a negative charging photosensitive member structure having the function separation structure.

The constitution of the photosensitive layer of the function-separated negative charging photoreceptor will be described below. << Charge Generation Layer >> The charge generation layer of the present invention contains a charge generation substance and a binder resin, and is formed by dispersing and coating the charge generation substance in a binder resin solution.

As the charge generating substance, a known phthalocyanine compound can be used. Preferred are titanyl phthalocyanine compounds and hydroxygallium phthalocyanine compounds. Furthermore, Y type of titanyl phthalocyanine,
Cu-Kα characteristic X-rays (wavelength 1.54) such as A type (β type)
A titanyl phthalocyanine compound, which is characterized by a main peak of Bragg angle 2θ with respect to Å), is preferable. Regarding these oxytitanyl phthalocyanines, JP-A-10-06910
No. 7 publication. Further, these charge generating substances may be used alone or in combination of two or more kinds such as Y type and A type, or may be used by mixing with polycyclic quinone such as perylene pigment.

As the binder resin for the charge generation layer, known resins can be used. Examples thereof include polystyrene resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, Epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin,
Melamine resin, and copolymer resins containing two or more of these resins (for example, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin) and poly-vinyl Examples thereof include carbazole resin, but are not limited thereto.

The charge generation layer is formed by dispersing a charge generation substance in a solution in which a binder resin is dissolved with a solvent to prepare a coating solution, and coating the coating solution with a coating machine to a constant film thickness. Then, it is preferable that the coating layer is dried to be manufactured.

Solvents for dissolving and coating the binder resin used in the charge generation layer include, for example, toluene, xylene, methylene chloride, 1,2-dichloroethane, methyl ethyl ketone, cyclohexane, ethyl acetate, butyl acetate, methanol, ethanol. , Propanol, butanol, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, 1,4-dioxane, 1,3
-Dioxolane, pyridine, diethylamine and the like, but not limited thereto.

As the means for dispersing the charge generating substance, an ultrasonic disperser, a ball mill, a sand grinder, a homomixer or the like can be used, but it is not limited to these.

Examples of the coating machine for forming the charge generation layer include a dip coating machine and a ring coater, but the coating machine is not limited to these.

The mixing ratio of the charge generating substance to the binder resin is preferably 1 to 600 parts (hereinafter, “parts by weight”) of the charge generating substance relative to 100 parts by weight of the binder resin, and more preferably 50 to 500 parts. . The thickness of the charge generation layer varies depending on the characteristics of the charge generation substance, the characteristics of the binder resin, the mixing ratio, etc., but is preferably 0.01 to 5 μm.

<< Charge Transport Layer >> The charge transport layer of the present invention contains a charge transport substance and a binder resin, and is formed by dissolving and coating the charge transport substance in a binder resin solution.

As the charge transport material, Japanese Patent Application No. 2000-3609 is used.
In addition to the charge-transporting substances represented by the general formula in the specification of No. 98, for example, carbazole derivative, oxazole derivative, oxadiazole derivative, thiazole derivative, thiadiazole derivative, triazole derivative, imidazole derivative, imidazolone derivative, imidazolidine derivative,
Bisimidazolidine derivative, styryl compound, hydrazone compound, pyrazoline compound, oxazolone derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, triarylamine derivative, phenylenediamine derivative, stilbene derivative, benzidine Derivatives, poly-N-vinylcarbazole, poly-1-
Vinylpyrene and poly-9-vinylanthracene
You may use it in mixture of 2 or more types.

As the binder resin for the charge transport layer, known resins can be used, such as polycarbonate resin, polyacrylate resin, polyester resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polymethacrylate ester resin and styrene. -Methacrylic acid ester copolymer resin and the like can be mentioned, but polycarbonate is preferable. Furthermore, BPA and BP of polycarbonate
Z, dimethyl BPA, BPA-dimethyl BPA copolymer and the like are preferable in terms of cracking, abrasion resistance and charging characteristics.

The charge transport layer can be formed by dissolving the binder resin and the charge transport substance to prepare a coating solution, coating the coating solution with a coating machine to a constant film thickness, and drying the coating layer. preferable.

As the solvent for dissolving the binder resin and the charge transport substance, for example, toluene, xylene,
Methylene chloride, 1,2-dichloroethane, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, methanol, ethanol, propanol, butanol, tetrahydrofuran, 1,4-dioxane, 1,
Examples thereof include, but are not limited to, 3-dioxolane, pyridine and diethylamine.

The mixing ratio of the charge transport material to the binder resin is preferably 10 to 500 parts by weight of charge transport material (hereinafter referred to as “parts by weight”) per 100 parts by weight of the binder resin.
It is more preferably 20 to 100 parts.

The thickness of the charge transport layer varies depending on the characteristics of the charge transport material, the characteristics of the binder resin, the mixing ratio, etc., but is preferably 10 to 100 μm, more preferably 15 μm.
Is about 40 μm.

Further, in the charge transport layer, an antioxidant (AO
Agent), an electron-accepting substance (EA agent), a stabilizer and the like may be added. Regarding the AO agent, Japanese Patent Application No. 11-200135
Nos. And EA agents are preferably those described in JP-A Nos. 50-137543 and 58-76483.

<< Protective Layer >> In order to improve durability, a protective layer may be provided on the charge transport layer. JP-A-9-1900
04, JP-A-10-095787, JP-A 2000-
A protective layer using a siloxane-based resin described in each publication of No. 171990 improves abrasion resistance and is preferable. In the above, the layer structure of the most preferred organic photoreceptor of the present invention is exemplified,
In the present invention, a layer structure other than the above may be used.

Inorganic fine particles having a number average particle diameter of 5 to 1000 nm are preferably added to the surface layer of the photoreceptor of the present invention. By including such inorganic fine particles on the surface of the photoconductor, it is possible to improve the abrasion strength of the organic photoconductor and obtain a highly durable organic photoconductor. Further, by giving such a photosensitive member the end shape of the present invention, it is possible to prevent the cleaning blade from being worn out or cut, and it is highly durable and does not cause defective cleaning. Can be provided.

The surface roughness of the above-mentioned inorganic fine particles is preferably adjusted by dispersing and containing hydrophobically treated inorganic fine particles (for example, described in JP-A-8-248663) in the surface layer of the photoreceptor. . As a method of hydrophobizing the inorganic fine particles, a method of treating with a hydrophobizing agent such as a titanium coupling agent, a silane coupling agent, a polymeric fatty acid or a metal salt thereof can be used.

Examples of the inorganic fine particles include silica, titanium oxide, alumina, barium titanate, calcium titanate, strontium titanate, zinc oxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate and silicon carbide. Examples thereof include fine particles of silicon nitride, chromium oxide, red iron oxide and the like.

As described above, the inorganic fine particles are preferably subjected to a hydrophobizing treatment. The hydrophobizing treatment can be carried out by reacting the inorganic fine particles and the hydrophobizing agent at a high temperature. The hydrophobic treatment agent is not particularly limited,
For example, hexamethyldisilazane, dimethyldichlorosilane, decylsilane, dialkyldihalogenated silane,
Examples thereof include silane coupling agents such as trialkylhalogenated silanes and alkyltrihalogenated silanes, and dimethyl silicone oil. The amount of the hydrophobizing agent varies depending on the type of the fine particles and the like and cannot be specified unconditionally, but generally, the greater the amount, the higher the degree of hydrophobicity. It is also effective to remove the hygroscopic substance by, for example, reprecipitation or heat treatment.

The above number average particle diameter is a value measured as a Feret direction average particle diameter by observing 100 particles as primary particles at a magnification of 2000 times by observation with a transmission electron microscope.

Next, an image forming apparatus using the cylindrical photosensitive member manufactured by the method for manufacturing a cylindrical photosensitive member of the present invention will be described.

<Image Forming Apparatus> FIG. 7 is a sectional view showing an example of the image forming apparatus of the present invention.

In FIG. 7, reference numeral 50 is a photosensitive drum (photosensitive member) which is an image bearing member, and an organic photosensitive layer is coated on the drum.
A photosensitive member having the resin layer of the present invention applied thereon is grounded and driven and rotated clockwise. Reference numeral 52 denotes a scorotron charger (charging means) for uniformly charging the peripheral surface of the photosensitive drum 50 by corona discharge. This charger 5
Prior to the charging by 2, the exposure may be performed by the pre-charge pre-exposure unit 51 using a light emitting diode or the like to eliminate the history of the photo conductor in the pre-image formation to eliminate the charge on the peripheral surface of the photo conductor.

After the photosensitive member is uniformly charged, the image exposing device 53 as the image exposing means performs image exposure based on the image signal. The image exposure device 53 in this figure uses a laser diode (not shown) as an exposure light source. Rotating polygon mirror 5
Scanning on the photosensitive drum is performed by the light whose optical path is bent by the reflection mirror 532 through the 31, f.theta.
An electrostatic latent image is formed.

Here, the reversal development process of the present invention is to uniformly charge the surface of the photoconductor by the charger 52 and develop the image-exposed region, that is, the exposed portion potential (exposed region) of the photosensitive member. It is an image forming method that visualizes by a step (means). On the other hand, the unexposed portion potential is not developed by the developing bias potential applied to the developing sleeve 541.

The electrostatic latent image is then developed by the developing device 54 as a developing means. A developing device 54 containing a developer composed of toner and carrier is provided on the periphery of the photosensitive drum 50, and development is performed by a developing sleeve 541 that contains a magnet and holds the developer and rotates.
Inside the developing unit 54, the developer stirring and conveying members 544, 543,
The developer is constituted by a conveyance amount regulating member 542 and the like, and the developer is agitated and conveyed to be supplied to the developing sleeve, and the supply amount is controlled by the conveyance amount regulating member 542. The amount of the developer conveyed varies depending on the linear velocity of the applied organic electrophotographic photosensitive member and the specific gravity of the developer, but is generally 20 to 2
It is in the range of 00 mg / cm ² .

The developer includes, for example, a carrier having the above-mentioned ferrite as a core and coated with an insulating resin around the core, a coloring agent such as carbon black and a charge control agent mainly composed of the above-mentioned styrene acrylic resin, and a charge control agent of the present invention. Colored particles consisting of low molecular weight polyolefin, and toner externally added with silica, titanium oxide, etc., the developer is transported to the developing zone with the layer thickness regulated by the transport amount regulating member, and development is carried out. . At this time, normally, a DC bias is applied between the photosensitive drum 50 and the developing sleeve 541, and if necessary, an AC bias voltage is applied to develop. Further, the developer is developed in a state of being in contact with or non-contacting with the photoreceptor. The potential sensor 547 measures the potential of the photoconductor.
Is provided above the developing position as shown in FIG.

After the image formation, the recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 57 when the transfer timing is adjusted.

In the transfer area, a transfer electrode (transfer means: transfer device) 58 operates on the peripheral surface of the photosensitive drum 50 in synchronization with the transfer timing, and the recording paper P fed is charged with a polarity opposite to that of the toner. To transfer the toner.

Then, the recording paper P is separated by a separating electrode (separator) 59.
Is discharged by the peripheral surface of the photoconductor drum 50 and conveyed to the fixing device 60. The heat roller 601 and the pressure roller 602 heat and pressurize the toner to fuse the toner, and then the paper is discharged from the outside of the device via the paper discharge roller 61. Is discharged to. The transfer electrode 58 and the separation electrode 59 stop the primary operation after passing the recording paper P and prepare for the next toner image formation. In FIG. 7, a corotron transfer band electrode is used as the transfer electrode 58. The setting condition of the transfer electrode varies depending on the process speed (peripheral speed) of the photoconductor and cannot be specified unconditionally. For example, the transfer current is +
100 to +400 μA, transfer voltage +500 to +
2000V can be used as the set value.

On the other hand, after the recording paper P is separated, the photosensitive drum 50 is cleaned by the cleaning blade 621 of the cleaning device (cleaning means) 62 so as to remove and clean the residual toner. Upon receiving the charge from the container 52, the next image forming process starts. The cleaning blade 621 has a thickness of 1 to 30.
A rubber-like elastic body of about mm is used, and urethane rubber is often used as the material.

Reference numeral 70 denotes a detachable process cartridge in which a photoconductor, a charger, a transfer device, a separator and a cleaning device are integrated.

The organic electrophotographic photoreceptor of the present invention is generally applied to electrophotographic apparatuses such as electrophotographic copying machines, laser printers, LED printers and liquid crystal shutter type printers. It can be widely applied to devices such as printing, plate making, and facsimile.

[0082]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 Production of Cylindrical Photoreceptor As a cylindrical conductive substrate, an outer diameter of 80 m subjected to mirror finishing
An aluminum drum base having a length of m and a length of 355 mm was used.

An intermediate layer coating solution was prepared on the substrate as described below, and dip coating was performed so that the dry film thickness was 1.0 μm.

Intermediate layer coating liquid 50 g of ethylene-vinyl acetate copolymer (Elvax 4260: manufactured by Mitsui DuPont Chemical Co., Ltd.) Toluene / n-butanol = 5/1 (Vol ratio) 2000 ml The charge generation layer coating solution was dispersed and prepared, and dip coating was performed so that the dry film thickness was 0.5 μm.

Charge generation layer coating liquid Titanyl phthalocyanine pigment 100 g Silicone resin (KR-5240: manufactured by Shin-Etsu Chemical Co., Ltd.) 100 g t-Butyl acetate 1000 ml The above coating liquid composition is dispersed for 17 hours using a sand mill.

[0087]   Charge transport layer coating liquid   Charge transport material ([4- (2,2-diphenylvinyl) phenyl] diparatolyl Amine) 500g   Polycarbonate (Z-200: Mitsubishi Gas Chemical Co., Inc.) 560 g   Hydrophobic silica (number average particle size: 50 nm) 50 g   Dioxolane (bp 74-75 ° C) 2800 ml   Methylphenyl silicone oil (KF-54: manufactured by Shin-Etsu Chemical Co., Ltd.) 100 ppm was added to the total solid content.

A coating solution for the charge transport layer was prepared on the charge generation layer as described above, dip-coated to a dry film thickness of 23 μm, and a coating layer solution pool portion (below) formed by the apparatus shown in FIG. The cylindrical photoreceptor 1 is removed from the lower end of the photoconductor substrate by about 20 mm from the lower end of the photoconductor substrate by the method described in the method for removing the coating layer by changing the locus of the end portion of the coating layer, and then dried.
~ 6 were produced. The end locus of the coating layer of each cylindrical photoreceptor,
The meandering width or inclination width of the end locus is collectively shown in Table 1.

A copying machine Konica 705 manufactured by Konica Co., Ltd., which basically has the configuration shown in FIG.
0 (corona charging, laser exposure, reversal development, electrostatic transfer, nail separation, blade cleaning adopted process, printing speed A4 paper, 50 sheets / min), 24 ° C 6
200,000 sheets of A4 paper were copied in an environment of 0% RH, and the cleaning property and the abrasion or cutting of the cleaning blade were evaluated.

Cleaning conditions Hardness 70 °, impact resilience 65%, thickness 2 in cleaning area
(Mm) and a cleaning blade having a free length of 9 mm were brought into contact with each other by a weight load method in the counter direction so as to have a linear pressure of 18 (N / m). Cleaning blade length is 345
mm, and a gap was provided at both ends of the photoconductor 5 mm.

Table 1 shows the evaluation results.

[0092]

[Table 1]

As is clear from Table 1, the cylindrical photoconductors 1 to 5 having the coating layer end portion locus of the present invention have better cleaning property than the cylindrical photoconductor 6 of the present invention, and in particular, Cylindrical photoreceptors 1 to 4 were evaluated in the copy evaluation of 200,000 sheets.
Although no cleaning failure occurs, the cylindrical photoconductor 5
The toner slip-through occurs after about 180,000 sheets, and the toner slip-through occurs on the cylindrical photoconductor 6 after about 120,000 sheets. Further, in the cylindrical photoconductors 1 to 5, there is little or no abrasion mark of the cleaning blade in the portion contacting the locus of the coating layer end portion, but the cylindrical photoconductor 6 is more distinct. It appears that this is a difference in the occurrence of the cleaning failure.

[0094]

EFFECT OF THE INVENTION By using the cylindrical photosensitive member of the present invention (a cylindrical photosensitive member in which an unnecessary coating film at the lower end is removed and the end locus after removing the coating film is meandered or inclined), cleaning is performed. Does not cause wear or cutting of specific parts of the blade,
It is possible to provide an electrophotographic image having a good cleaning property.

[Brief description of drawings]

FIG. 1 is a diagram for explaining that an end locus of a coating layer meanders or inclines in a circumferential direction.

FIG. 2 is a diagram showing examples of various coating layer end loci.

FIG. 3 is a development view of an example in which an end locus of a coating layer meanders or inclines in a circumferential direction.

FIG. 4 is a cross-sectional view of a coating layer removing device using a brush.

FIG. 5 is a vertical cross-sectional view of a contact state between a cylindrical photosensitive member and a rubbing member.

FIG. 6 is an overall configuration diagram of a coating layer removing device.

FIG. 7 is a sectional view showing an example of an image forming apparatus of the present invention.

[Explanation of symbols]

1 Conductive substrate 2 coating layers 3 Cylindrical photoconductor p, q, r, s, t end locus

Claims (6)

[Claims] 1. An organic photoreceptor having a coating layer including a photosensitive layer on a cylindrical substrate, wherein an end locus of the coating layer meanders or inclines in a circumferential direction. 2. The meandering width or inclination width of the end locus is
The organic photoreceptor according to claim 1, which has a length of 0.5 mm or more and 10 mm or less. 3. The organophotoreceptor according to claim 1, wherein the surface layer of the organophotoreceptor contains inorganic fine particles. 4. A method for producing an organic photoreceptor having a coating layer containing at least a photosensitive layer on a cylindrical substrate, wherein after coating the coating layer on the cylindrical substrate, the end of the coating layer is impregnated with a solvent. The step of removing the cylindrical base body relative to the rubbing member relative to the rubbing member, and at the same time, the cylindrical base body is moved in the central axis direction to remove the coating layer end portion. Is removed to form an end locus of the coating layer meandering or sloping in the circumferential direction. 5. A cleaning blade is used to remove residual toner on an organic photoconductor having a coating layer including a photosensitive layer on a cylindrical substrate, and the end locus of the coating layer meanders or is inclined in the circumferential direction. A method for cleaning toner, which comprises: 6. An image forming apparatus using the cleaning method according to claim 5.