JP2013054151A - Method for manufacturing cylindrical substrate for electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a cylindrical substrate for an electrophotographic photoreceptor for obtaining the electrophotographic photoreceptor in which generation of interference stripes is suppressed even when a halftone image with high image quality is output.SOLUTION: A method for manufacturing a cylindrical substrate for an electrophotographic photoreceptor is the method for manufacturing the cylindrical substrate in the electrophotographic photoreceptor at least having a photosensitive layer on the cylindrical substrate, and has a cutting process of relatively moving a processing blade in a tube axis direction at set transmission speed from one end to the other end of a processed area on the outer peripheral surface of a circular tube material while bringing the processing blade into contact with the processed area at a state that the circular tube material is rotated centering around its tube axis, and changes the transmission speed of the processing blade to the circular tube material for a plurality of times in the cutting process. The transmission speed is preferably changed for three or more times per 1 cm of moving distance of the processing blade to the circular tube material.

Description

  The present invention is a cylindrical substrate for an electrophotographic photosensitive member (hereinafter simply referred to as “cylindrical substrate”) that constitutes an electrophotographic photosensitive member that can be used in the field of light printing and the like and can output a halftone image with extremely high image quality. )).

In recent years, with respect to an image forming apparatus based on electrophotography, it has become possible to obtain a relatively high-quality image as its performance is improved. The image forming apparatus according to has been widely used.
As a result, an image forming apparatus based on electrophotography is required to have a higher level of image quality. Also, it is rarely used in conventional electrophotographic image forming apparatuses, such as printing on coated paper, printing of high-coverage images, printing of extremely high-definition images and images with subtle tones (color tone), and the same An electrophotographic image forming apparatus is used for mass continuous printing of images. Along with these problems, there have been problems that have been hardly or not pointed out in the past.

One of the problems is the occurrence of oblique streak-like density unevenness in images, which has frequently occurred in recent years in the combination of outputting a halftone image with improved uniformity of intermediate colors to coated paper, etc., using a high-quality image forming apparatus. There is.
This oblique stripe-shaped density unevenness is so-called interference streak, and is the surface of a cylindrical substrate of an electrophotographic photosensitive member (hereinafter also simply referred to as “photosensitive member”) used in an electrophotographic image forming apparatus. In order to make the dimensional accuracy of the outer diameter, etc. a desired level, or to make it fresh except for the oxide film on the surface, cutting irregularities are periodically formed on the outer peripheral surface in the tube axis direction. It is presumed that it is caused by interference between the period of the cutting irregularities formed on the surface of the cylindrical substrate of the photoconductor and the period (pitch) of the screen pattern (exposure pattern) used for the screen processing. .

As a technique for suppressing the occurrence of interference stripes, there is a technique for devising the shape of the cutting irregularities on the surface of a cylindrical substrate constituting a photoreceptor (for example, Patent Documents 1 and 2). That is, the cutting shape on the surface of the cylindrical substrate is often formed by cutting with a bite, but cutting irregularities with a relatively less harmful cycle such as a cycle that is not an integral multiple of the cycle of the exposure pattern are obtained by constant-speed cutting. It has been practiced to eliminate the uneven shape of the cut by performing additional processing which is costly and harmful, such as anodizing and blasting.
In an image forming apparatus using a cylindrical substrate photoconductor having such cut irregularities, a general halftone image output on plain paper in an office or the like is satisfactory as having a sufficient image quality level. It had been.

  However, the density unevenness visibility is marked for the output of a halftone image in which the uniformity of the intermediate color is improved to the coated paper by the high-quality image forming apparatus used in the light printing field as described above. Therefore, the above-described technique is not sufficient in suppressing the occurrence of interference streaks.

JP 2003-91085 A Japanese Patent No. 3894023

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide an electrophotographic photosensitive member capable of suppressing the occurrence of interference streaks even when a high-quality halftone image is output. An object of the present invention is to provide a method for producing a cylindrical substrate for an electrophotographic photosensitive member capable of obtaining the above.

The method for producing a cylindrical substrate for an electrophotographic photoreceptor of the present invention is a method for producing the cylindrical substrate in an electrophotographic photoreceptor having at least a photosensitive layer on the cylindrical substrate,
In a state where the circular pipe is rotated around its tube axis, the processing blade is set from one end to the other end of the processing area while bringing the processing blade into contact with the processing area on the outer peripheral surface of the circular pipe. A cutting process for moving in the direction of the pipe axis at the feed rate
In the cutting step, the feed rate of the processing blade to the circular pipe material is changed a plurality of times.

  In the method for producing a cylindrical substrate for an electrophotographic photosensitive member of the present invention, it is preferable to change the feed speed at least three times per 1 cm of the moving distance of the processing blade with respect to the circular pipe material.

  According to the method for manufacturing a cylindrical base body of the present invention, by changing the feed rate of the machining blade to the circular pipe material a plurality of times, irregularities in the period of the cutting irregularities in the tube axis direction on the surface of the obtained cylindrical base body are obtained. Can be expressed. Even when a high-quality halftone image is output by using such a photoconductor having a cylindrical substrate, the cycle of the screen pattern and the cycle of the cutting irregularities formed on the surface of the cylindrical substrate are Therefore, it is possible to reliably obtain a high-quality halftone image in which the occurrence of interference lines is suppressed.

FIG. 2 is a partial cross-sectional view showing an example of the configuration of a photoreceptor provided with a cylindrical substrate obtained by the method for producing a cylindrical substrate for an electrophotographic photoreceptor of the present invention. It is an image figure of the interference stripe which appears in the formed halftone image. It is the elements on larger scale in the cross section of a photoreceptor. It is a figure explaining the measuring method of (DELTA) L. 1 is a cross-sectional view illustrating an example of a configuration of an image forming apparatus on which a photoconductor according to the present invention is mounted.

  Hereinafter, the present invention will be specifically described.

[Method of manufacturing cylindrical substrate]
The method for producing a cylindrical substrate of the present invention is a method for producing a cylindrical substrate in a photosensitive member, which will be described in detail later, with a circular pipe (hereinafter also referred to as “element tube”) as the center of the tube axis. In the rotated state, the processing blade is moved in the tube axis direction at a set feed speed from one end to the other end of the processing region while bringing the processing blade into contact with the processing region on the outer peripheral surface of the circular pipe material. It has a cutting process that moves relatively, and the feed speed of the processing blade to the circular pipe material in the cutting process is changed a plurality of times, that is, the processing area of the raw pipe is changed with respect to the raw pipe. It is characterized by being moved non-constantly from one end to the other end.
The cutting process of the cylindrical substrate is to make the dimensional accuracy such as the outer diameter of the cylindrical substrate a desired level, to be fresh except for the oxide film on the surface of the cylindrical substrate, and to make the surface of the cylindrical substrate a desired shape. This is done for the purpose.

  As a concrete means for performing the cutting process, a cutting tool using a lathe and using a cutting tool as a processing blade can be used.

  The element tube is not particularly limited as long as it has conductivity, and examples thereof include a material obtained by forming a metal such as aluminum, copper, chromium, nickel, zinc and stainless steel into a drum shape.

The feed speed is preferably changed three times or more per 1 cm of the moving distance of the cutting tool relative to the raw tube, and particularly preferably 3 to 6 times per 1 cm of the moving distance.
If the feed rate is changed less frequently, the resulting cylindrical substrate may not have a sufficiently reduced periodicity of the cutting irregularities, and as a result, depending on the screen pattern used for the screen processing, there are sufficient interference streaks. It may not be possible to suppress the occurrence of.

In the case where a CNC lathe is used for the cutting of the cutting tool, specifically, a combination of an instruction speed X _n (μm / rotation) of the cutting tool and a moving distance Y _n (mm) of the cutting tool with respect to the raw pipe is specified. By executing a specific program of n blocks composed of (X ₁ , Y ₁ ), (X ₂ , Y ₂ ),... (X _n , Y _n ), in which a feed speed setting command is instructed a plurality of times, Perform cutting tool processing.

In this specific program, the indicated speeds indicated in adjacent blocks may be the same value.
This is because, for example, in the m-th block, when (Y _{m + 1} −Y _m ) / X _m does not become a specific number, the actual feed speed of the cutting tool is set to enable switching at the end point of the m-th block. This is because in the next m + 1th block, the speed is increased to the command speed _{Xm + 1,} and as a result, the actual feed speed of the cutting tool can be changed.

In this particular program, the change amount of the indicated rate, for feed rate X _m-1 in the feed rate X _m and the m-1 block in the m blocks, absolute (X _m -X _m-1) / X _m The amount of change is preferably 0.01 to 0.3, and more preferably 0.02 to 0.1.

  In this specific program, the indicated speed of each block is preferably in the range of 100 μm / revolution to 600 μm / revolution.

In the particular program, in order to further reduce the periodicity of the cutting irregularities, the amount of change in the moving distance is not constant, i.e. the moving distance Y _m in the moving distance Y _m and the m-1 block in the m blocks It is desirable that Y _m -Y _m-1 is not constant for _-1 .

  As a specific aspect of the change in the feed speed in the specific program, an aspect in which the increase / decrease is repeated within a certain speed range can be exemplified.

Further, when an analog lathe is used for the cutting of the cutting tool, the cutting of the cutting tool is performed by instructing a change of the feed speed with respect to the moving distance a plurality of times.
Specifically, the feed speed of the cutting tool can be changed, for example, by outputting a motor voltage that controls the feed speed of the cutting tool, for example, through a circuit that switches a plurality of resistors. Further, for example, the feed rate can be changed by moving the cutting tool using a power source capable of outputting a voltage having a specified waveform.

  The feed rate is preferably in the range of 100 μm / revolution to 600 μm / revolution.

  It is desirable that the moving distance when changing the feed rate, that is, the instruction interval for changing the feed rate, is not constant in order to further reduce the periodicity of the cutting irregularities. The fact that the instruction interval for changing the feed rate is not constant can be achieved by using a plurality of switching timers, or by using a power supply that can complicate the output waveform by superimposing different waveforms. .

  Moreover, as a specific aspect of the change in feed speed, an aspect in which the increase / decrease is repeated within a certain speed range can be exemplified.

  In the tool cutting process, it is preferable that the spindle rotational speed (the rotational speed of the raw pipe) is 2000 to 7000 rpm in any case where a CNC lathe or an analog lathe is used.

  The cylindrical substrate obtained by the above manufacturing method has a difference ΔL between the maximum value and the minimum value of the periodic width of the cutting unevenness in the tube axis direction in the image area on the outer peripheral surface thereof, that is, the period is inconsistent. The cutting irregularities having regularity are formed. Note that the cutting irregularities formed by the conventional cutting tool in which the cutting tool is brought into contact with the raw pipe while moving at a constant speed has a constant cycle in the pipe axis direction, that is, theoretically ΔL = 0. It becomes. Some errors may appear as ΔL depending on the precision of the cutting tool. In the present invention, “changing the feed speed a plurality of times” means intentionally changing the feed speed a plurality of times.

(Measurement method of ΔL)
ΔL is read from a cross-sectional curve of the image area on the outer peripheral surface, for example, as illustrated in FIG. Specifically, from the cross-sectional curve of FIG. 4A, the repetitive shape and period are focused, and the period width is read by increasing to an appropriate magnification as shown in the cross-sectional curve of FIG. 4B. Is. In addition, the cross-sectional curve of FIG.4 (b) makes lateral magnification 4 times the cross-sectional curve of Fig.4 (a).

  The number of periods of the cutting unevenness measured for reading the maximum value and the minimum value of the periodic width of the cutting unevenness may be 5 or more.

  The measurement location of the cross-sectional curve may be an arbitrary location in the image area on the outer peripheral surface of the cylindrical substrate, and may be one location or a plurality of locations. When the measurement location is one location, it is only necessary to read the maximum value and the minimum value from the periodic width of the cutting irregularities of 5 cycles or more that are continuous or intermittent from the measurement location, and when the measurement location is a plurality of locations, It is only necessary to select a periodic width of the cutting irregularities of 5 cycles or more from the plurality of measurement points and read the maximum value and the minimum value from these.

  As the measurement location of the cross-sectional curve, for example, the vicinity of the center of the cylindrical base in the tube axis direction is preferably selected.

The measurement length of the cross-sectional curve may be any length as long as the period width of the cutting irregularities can be read. However, when the number of measurement points is one, the period width of the cutting irregularities is a length that can be read by at least five cycles. It is preferable that the length is readable for 10 cycles or more.
The measurement length of the cross-sectional curve is specifically 4 mm, for example.

  The cross-sectional curve of the image region on the outer peripheral surface of the cylindrical substrate is obtained under the following measurement conditions using a stylus type surface roughness measuring instrument “Surfcom 1400D” (manufactured by Tokyo Seimitsu Co., Ltd.).

-Measurement conditions-
・ Measurement mode: Roughness measurement (JIS'01 standard)
・ Measurement length: 4.0mm
・ Cutoff: 0.8mm (Gaussian)
・ Measurement speed: 0.3mm / sec

  According to the method for manufacturing a cylindrical base as described above, the cycle of the cutting irregularities in the tube axis direction on the surface of the obtained cylindrical base is irregular by changing the feed rate of the processing blade to the circular pipe material a plurality of times. Can be expressed. Even when a high-quality halftone image is output by using such a photoconductor having a cylindrical substrate, the cycle of the screen pattern and the cycle of the cutting irregularities formed on the surface of the cylindrical substrate are Therefore, it is possible to reliably obtain a high-quality halftone image in which the occurrence of interference lines is suppressed.

The reason why the above effect is obtained is as follows.
FIG. 2 shows interference streaks appearing in the formed halftone image, which is a problem in the present invention. Thus, the interference streaks appear on the screen r as oblique stripe-shaped density unevenness extending in the circumferential direction of the photosensitive member, that is, in the direction along the conveying direction s of the image support P, and a uniform image. In particular, it is clearly visible in a high-quality halftone image of a large screen such as a light print on a smooth surface image.

  According to the inventor's investigation, the cause of the occurrence of the interference streak which is regarded as a problem in the present invention is as follows.

FIG. 3 is a partially enlarged view of the cross section of the photoconductor.
The interference streaks are not caused by the cutting irregularities of the cylindrical substrate itself, but are caused by the sensitivity of the photoreceptor 1 having a period reflecting the cutting irregularities.
That is, as shown in FIG. 3, the shape of the cutting irregularities on the surface of the cylindrical substrate 1a is reflected in the film thickness of the charge generation layer (CGL) 1c through the intermediate layer 1b, and specifically, the cylindrical substrate 1a. A portion β having a large film thickness, a portion α having a small film thickness, or the like is generated corresponding to the depth of the cutting unevenness of the film. As a result, the photosensitive member 1 has a film thickness of the charge generation layer 1c in accordance with a regular cycle. It will fluctuate.
Since the sensitivity of the photoreceptor 1 varies according to the film thickness of the charge generation layer 1c, the sensitivity pattern of the photoreceptor 1 and the screen pattern related to the exposure when exposure is performed by a laser beam, an LED light source, or the like. In the image obtained by developing, transferring, and fixing the electrostatic latent image, the image has a high image quality. In some cases, it is visualized as periodic density unevenness, that is, interference streaks.

In the present invention, it is extremely effective for suppressing the occurrence of interference streaks that the period width of the cutting irregularities generated by cutting in the area corresponding to the image area of the photoreceptor on the surface of the cylindrical substrate is changed to some extent. As a result, it has been completed as a method for forming cutting irregularities having irregularity in such a cycle.
In addition, the cylindrical substrate finished by the conventional cutting tool has a shape in which cutting irregularities are formed very regularly in the tube axis direction, and the film thickness of the photosensitive layer formed on the cylindrical substrate. The distribution has a periodicity reflecting the shape, and the reflection does not easily disappear even when layers are stacked, such as through an intermediate layer.

[Photoconductor]
FIG. 1 is a partial cross-sectional view showing an example of the structure of a photoreceptor provided with a cylindrical substrate obtained by the method for producing a cylindrical substrate for an electrophotographic photoreceptor of the present invention.
In this photoreceptor 1, an intermediate layer 1b, a charge generation layer 1c, a charge transport layer 1d, and a protective layer 1e are laminated in this order on a cylindrical substrate 1a. From the charge generation layer 1c and the charge transport layer 1d, electrophotography is performed. A photosensitive layer 1α that is indispensable for the configuration of the photoreceptor is configured. Such a photoreceptor 1 is preferably a so-called organic photoreceptor in which the charge generation layer 1c and the charge transport layer 1d are organic photosensitive layers made of a known organic charge generation material and organic charge transport material, respectively.
In the following description, it is assumed that the specific photoreceptor is an organic photoreceptor.

(Middle layer)
The intermediate layer provides a barrier function and an adhesive function between the cylindrical substrate and the organic photosensitive layer. From the viewpoint of preventing various failures, it is preferable to provide such an intermediate layer.

For the intermediate layer, a coating solution is prepared by dissolving a binder resin such as casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide, polyurethane, alkyd-melamine, epoxy and gelatin in a known solvent. Can be formed by coating the outer peripheral surface of the cylindrical substrate by dip coating or the like to form a coating film and drying the coating film.
As the binder resin for forming the intermediate layer, it is preferable to use an alcohol-soluble polyamide resin.

Further, the intermediate layer may contain various fine particles such as metal oxide particles for the purpose of adjusting resistance and imparting roughness.
According to a specific photoconductor in which various fine particles are contained in the intermediate layer, the surface shape of the intermediate layer reflects a random convex shape derived from the shape of the fine particles in addition to the cutting irregularities on the surface of the cylindrical substrate. Therefore, the periodicity of the sensitivity derived from the shape of the surface of the cylindrical substrate can be reduced, and the generation of interference streaks can be extremely effectively suppressed.

  Examples of the metal oxide particles include fine particles such as alumina, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony-doped tin oxide, and zirconium oxide. It is done.

  These metal oxide particles may be used in combination of two or more. When two or more types are mixed, it may take the form of a solid solution or fusion. The average particle size of such metal oxide particles is preferably 0.3 μm or less, more preferably 0.1 μm or less. These metal oxide particles may be surface-treated with an inorganic compound or an organic compound in a single or multiple manner.

  Examples of the solvent that dissolves the binder resin that forms the intermediate layer include known ones. For example, when alcohol-soluble polyamide is used as the binder resin, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, and n-butanol are used. C1-C4 alcohols such as t-butanol and sec-butanol are preferred because of excellent solubility and coating performance of polyamide. Further, in order to improve coating properties, storage stability, fine particle dispersibility, etc., it is preferable to use a co-solvent together with a solvent. Etc.

  The concentration of the binder resin in the coating solution for forming the intermediate layer is appropriately selected according to the film thickness and production rate of the intermediate layer.

  When the intermediate layer contains fine particles, the mixing ratio of the fine particles with respect to the binder resin is preferably 20 to 400 parts by volume, more preferably 40 to 200 parts by volume with respect to 100 parts by volume of the binder resin.

  As a means for dispersing fine particles, an ultrasonic disperser, a ball mill, a sand grinder, a homomixer, or the like can be used, but is not limited thereto. A preferred example is a bead mill using beads having an average particle diameter of 0.1 to 0.5 mm.

  The intermediate layer coating solution can prevent the occurrence of image defects by filtering foreign matter and aggregates before coating.

  Although the drying method of an intermediate | middle layer can be suitably selected according to the kind of binder resin and a solvent, and a film thickness, heat drying is preferable.

  The film thickness of the intermediate layer is preferably 0.1 to 30 μm, and more preferably 0.3 to 15 μm.

(Charge generation layer)
The charge generation layer constituting a specific photoconductor is a binder resin containing a charge generation material.

  Examples of charge generation materials include azo pigments such as Sudan Red and Diane Blue, quinone pigments such as pyrenequinone and anthanthrone, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo, and phthalocyanine pigments. It is not something. These charge generating substances can be used alone or in a form dispersed in a known resin.

  As the binder resin for forming the charge generation layer, known resins can be used. For example, 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 resin containing two or more of these resins (for example, vinyl chloride-vinyl acetate copolymer resin) , Vinyl chloride-vinyl acetate-maleic anhydride copolymer resin) and polyvinyl carbazole resin, but are not limited thereto.

  The charge generation layer is prepared by dispersing a charge generation material in a solution in which a binder resin is dissolved in a solvent using a disperser to prepare a coating solution, and the coating solution is fixed on the outer peripheral surface of the intermediate layer by a coating device. It is preferable to apply to a film thickness and dry to produce a coating film.

  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, 4-methoxy-4-methyl-2-pentanone, cyclohexane, Examples include, but are not limited to, ethyl acetate, butyl acetate, methanol, ethanol, propanol, butanol, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, 1-dioxane, 1,3-dioxolane, pyridine, and diethylamine.

  As a 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 is not limited thereto.

The mixing ratio of the charge generating material to the binder resin is preferably 10 to 600 parts by mass, more preferably 50 to 500 parts by mass with respect to 100 parts by mass of the binder resin.
The thickness of the charge generation layer varies depending on the characteristics of the charge generation material, the characteristics of the binder resin, the mixing ratio, and the like, but is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm. It should be noted that the coating solution for the charge generation layer can prevent the occurrence of image defects by filtering foreign matter and aggregates before coating. It can also be formed by vacuum deposition of the pigment.

(Charge transport layer)
The charge transport layer constituting the specific photoreceptor is a binder resin containing a charge transport material (CTM).

  Examples of the charge transport material include carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazolines. Compound, oxazolone derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, triarylamine derivative, phenylenediamine derivative, stilbene derivative, benzidine derivative, poly-N-vinylcarbazole, poly-1 -Vinylpyrene, poly-9-vinylanthracene, triphenylamine derivatives, etc. Mixed and may also be used.

  As the binder resin for forming the charge transport layer, known resins can be used, such as polycarbonate resin, polyarylate resin, polyester resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polymethacrylate resin, and styrene- Examples thereof include methacrylic acid ester copolymer resins, and polycarbonate resins are preferably used. In addition, it is preferable to use BPA, BPZ, dimethyl BPA, BPA-dimethyl BPA copolymer and the like in terms of crack resistance, wear resistance, and charging characteristics.

  The charge transport layer is prepared by dissolving a binder resin and a charge transport material in a solvent to prepare a coating solution, applying the coating solution to the outer peripheral surface of the charge generation layer to a certain thickness by a coating machine, and drying the coating film. It is preferable to produce it.

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

  The mixing ratio of the charge transport material to the binder resin is preferably 10 to 500 parts by mass, more preferably 20 to 100 parts by mass with respect to 100 parts by mass of the binder resin.

  The film 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, and the like, but is preferably 5 to 40 μm, more preferably 10 to 30 μm.

  An antioxidant, an electronic conductive agent, a stabilizer and the like may be added in the charge transport layer. Examples of the antioxidant include those described in JP-A No. 2000-305291, and examples of the electronic conductive agent include those described in JP-A Nos. 50-137543 and 58-76483.

(Protective layer)
A specific photoreceptor may be provided with a protective layer on the outermost surface, that is, on the charge transport layer, if necessary.

[Image forming apparatus]
FIG. 5 is an explanatory sectional view showing an example of the configuration of the image forming apparatus on which the photoconductor according to the present invention is mounted.
This image forming apparatus is called a tandem type color image forming apparatus. Each of the image forming units 10Y, 10M, 10C, and 10Bk that forms yellow, magenta, cyan, or black toner images, and these image forming units. Image formation comprising an intermediate transfer unit 7 for transferring toner images of respective colors formed on 10Y, 10M, 10C, and 10Bk onto the image support P, and fixing means 24 for fixing the toner image to the image support P An apparatus main body A is provided, and an original image reading apparatus SC for optically scanning an original and reading image information as digital data (original image data) is disposed above the image forming apparatus main body A.

The image forming unit 10Y will be described in detail below.
Each of the image forming units 10M, 10C, and 10Bk forms a toner image with magenta toner, cyan toner, and black toner instead of yellow toner, and basically has the same configuration as the image forming unit 10Y. Is.

  The image forming unit 10Y is exposed around a drum-shaped photoreceptor 1Y that is an image forming body, a charging unit 2Y that applies a uniform potential to the surface of the photoreceptor 1Y, and a uniformly charged photoreceptor 1Y. Exposure unit 3Y that performs exposure based on the image data signal (yellow) for image formation and forms an electrostatic latent image corresponding to the yellow image, and conveys color toner onto the photoreceptor 1Y to visualize the electrostatic latent image The developing means 4Y for cleaning and the cleaning means 6Y for collecting the residual toner remaining on the photoreceptor 1Y after the primary transfer are arranged to form a yellow (Y) toner image on the photoreceptor 1Y.

  As the charging means 2Y, a corona discharge type charger is used.

  As the exposure unit 3Y, a light emitting device using a light emitting diode as an exposure light source, for example, an LED unit in which light emitting elements made of light emitting diodes are arrayed in the axial direction of the photoreceptor 1Y and an imaging element Alternatively, the image forming apparatus shown in FIG. 5 uses a laser irradiation device, such as a laser optical system laser irradiation device using a semiconductor laser as an exposure light source.

  The exposure means 3Y is preferably composed of an apparatus using a semiconductor laser or light emitting diode having an oscillation wavelength of 350 to 850 nm as an exposure light source. By using such an exposure light source with an exposure dot diameter of 10 to 100 μm narrowed down in the writing direction, and performing digital exposure on the photoreceptor 1Y, a high-resolution electrophotographic image of 600 to 2400 dpi or more is provided. Can be obtained.

The exposure method in the exposure means 3Y may be a scanning optical system using a semiconductor laser or a solid type using an LED. Regarding the light intensity distribution, there are a Gaussian distribution, a Lorentz distribution, etc., but an area of 1 / e ² or more of each peak intensity may be set as the exposure dot diameter.

  In the image forming apparatus of this example, the photosensitive member 1Y, the charging unit 2Y, the developing unit 4Y, and the cleaning unit 6Y in the image forming unit 10Y are provided as an integrated process cartridge.

  The image forming apparatus as described above is configured by integrally coupling a photosensitive member in one image forming unit and components such as a developing unit and a cleaning unit as a process cartridge, and this process cartridge is attached to the main body of the image forming apparatus. On the other hand, it may be configured to be detachable. In addition, a process cartridge is formed by integrally supporting at least one of a charging unit, an exposure unit, a developing unit, a transfer unit or a separation unit (not shown), and a cleaning unit in one image forming unit together with a photosensitive member. It may be configured to be detachable from the main body of the image forming apparatus using a guide means.

  The intermediate transfer unit 7 is formed by an endless belt-like intermediate transfer body 70 that is stretched by a plurality of support rollers 71 to 74 and supported so as to be circulated, and image forming units 10Y, 10M, 10C, and 10Bk, respectively. The primary transfer rollers 5Y, 5M, 5C, and 5Bk for transferring the toner image to the intermediate transfer member 70, and the toner image transferred onto the intermediate transfer member 70 by the primary transfer rollers 5Y, 5M, 5C, and 5Bk are image supports. A secondary transfer roller 5b for transferring onto P and a cleaning means 6b for collecting residual toner remaining on the intermediate transfer member 70 are provided.

  The primary transfer roller 5Bk in the intermediate transfer unit 7 is always in contact with the photoconductor 1Bk during the image forming process, and the other primary transfer rollers 5Y, 5M, and 5C are each only when forming a color image. It contacts the corresponding photoreceptors 1Y, 1M, 1C.

  Further, the secondary transfer roller 5b is brought into contact with the intermediate transfer body 70 only when the image support P passes through the secondary transfer roller 5b and the secondary transfer is performed.

  In this image forming apparatus, each of the process cartridges in the image forming units 10Y, 10M, 10C, and 10Bk and other than the secondary transfer roller 5b of the intermediate transfer unit 7 are housed in a housing 8, and the housing 8 is configured to be drawable from the image forming apparatus main body A through the support rails 82L and 82R.

  In this image forming apparatus, among the photoreceptors 1Y, 1M, 1C, and 1Bk of all the image forming units 10Y, 10M, 10C, and 10Bk, all the photoreceptors 1Y, 1M, 1C, and 1Bk perform the above-described cutting process. It is preferable that the photosensitive member is made of a specific photosensitive member having a cylindrical substrate obtained through the above process, but if at least one of the photosensitive members 1Y, 1M, 1C, and 1Bk is composed of the specific photosensitive member, An effect of forming a high-quality image in which the generation of interference lines is suppressed can be obtained.

  The image forming apparatus equipped with the photoconductor according to the present invention is generally applicable to electrophotographic apparatuses such as electrophotographic copying machines, laser printers, LED printers, and liquid crystal shutter printers. The present invention can be widely applied to apparatuses such as recording, light printing, plate making and facsimile.

(Image forming method)
In the above image forming apparatus equipped with the photoreceptor according to the present invention, the surfaces of the photoreceptors 1Y, 1M, 1C, and 1Bk are charged by the charging means 2Y, 2M, 2C, and 2Bk, and the exposure means 3Y, 3M. 3C and 3Bk are operated in accordance with exposure image data signals of respective colors obtained by performing various image processing and the like on the document image data obtained by the document image reading device SC. A laser beam modulated in accordance with the data signal is output from the exposure light source, and the photoconductors 1Y, 1M, 1C, and 1Bk are scanned and exposed by the laser beam, whereby the document read by the document image reading device SC. Electrostatic latent images corresponding to the respective colors of yellow, magenta, cyan, and black are formed on the respective photoreceptors 1Y, 1M, 1C, and 1Bk.

Next, the electrostatic latent images formed on the photoreceptors 1Y, 1M, 1C, and 1Bk are developed with the toners of the respective colors in the developing units 4Y, 4M, 4C, and 4Bk, thereby forming toner images of the respective colors. The toner images of the respective colors are sequentially transferred onto the intermediate transfer body 70 by the transfer rollers 5Y, 5M, 5C, and 5Bk, and are superimposed and combined to form a color toner image.
Further, in synchronism with the formation of the color toner image, the image support P such as plain paper or transparent sheet accommodated in the paper feed cassette 20 is fed by the paper feed means 21 and a plurality of intermediate rollers 22A, 22B. , 22C, 22D and the registration roller 23, the color toner images conveyed to the secondary transfer roller 5b and transferred onto the intermediate transfer body 70 by the secondary transfer roller 5b on the image support P in a lump. Transcribed.
The color toner image transferred onto the image support P is fixed by, for example, heating and pressurization in the fixing unit 24 to form a visible image, and then the image support P on which the visible image has been formed is discharged to the discharge roller. 25 is discharged out of the apparatus and placed on the discharge tray 26.

The photoreceptors 1Y, 1M, 1C, and 1Bk after the toner images of the respective colors are transferred to the intermediate transfer member 70 remain on the photoreceptors 1Y, 1M, 1C, and 1Bk by the cleaning units 6Y, 6M, 6C, and 6Bk, respectively. After the toner is removed, it is used to form toner images of the following colors.
On the other hand, the intermediate transfer member 70 after the color toner image is transferred onto the image support P by the secondary transfer roller 5b and the curvature of the image support P is separated is left on the intermediate transfer member 70 by the cleaning means 6b. After the removed toner is removed, it is used for intermediate transfer of the next toner image.

[Toner and developer]
The toner used in the image forming method using the photoconductor according to the present invention may be a pulverized toner or a polymerized toner. However, in the image forming method using the photoconductor according to the present invention, the toner is stable. From the viewpoint of obtaining a particle size distribution, it is preferable to use a polymerized toner prepared by a polymerization method.

  A polymerized toner is obtained by generating a binder resin for forming a toner and forming a toner particle shape by performing polymerization of raw material monomers to obtain a binder resin and, if necessary, subsequent chemical treatment in parallel. Means toner.

  More specifically, it means a toner formed through a step of obtaining resin fine particles by a polymerization reaction such as suspension polymerization or emulsion polymerization, and a step of fusing the resin fine particles performed thereafter if necessary.

  The volume average particle diameter of the toner, that is, the 50% volume particle diameter (Dv50) is preferably 2 to 9 μm, more preferably 3 to 7 μm. By setting this range, the resolution can be increased. In addition, by combining with the above range, the amount of toner having a fine particle diameter can be reduced while being a small particle diameter toner, the dot image reproducibility is improved over a long period of time, and the sharpness is excellent. In addition, a stable image can be formed.

  The toner used in the image forming method using the photoreceptor according to the present invention may be used alone as a one-component developer, or may be mixed with a carrier and used as a two-component developer.

  When used as a one-component developer, a non-magnetic one-component developer or a magnetic one-component developer containing about 0.1 to 0.5 μm of magnetic particles in the toner can be used. be able to.

  In addition, when used as a two-component developer by mixing with a carrier, conventionally known magnetic particles of the carrier, such as metals such as iron, ferrite and magnetite, alloys of these metals with metals such as aluminum and lead, etc. Material can be used. Ferrite particles are particularly preferable. The magnetic particles preferably have a volume average particle size of 15 to 100 μm, more preferably 25 to 80 μm.

  The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  The carrier is preferably a carrier in which magnetic particles are further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene-acrylic resin, silicone resin, ester resin, fluorine-containing polymer resin, or the like is used. In addition, the resin for constituting the resin-dispersed carrier is not particularly limited, and a known resin can be used. For example, a styrene-acrylic resin, a polyester resin, a fluorine resin, a phenol resin, or the like is used. be able to.

  According to the image forming method using the photoconductor according to the present invention as described above, the period of the exposure pattern and the electrophotographic photosensitivity are obtained because the cylindrical substrate of the photoconductor has reduced periodicity of the cutting irregularities. Interference with the period of the cutting irregularities formed on the surface of the cylindrical body of the body is reduced, and therefore the occurrence of interference streaks in the obtained high-quality halftone image is suppressed.

  As mentioned above, although embodiment of this invention was described concretely, embodiment of this invention is not limited to said example, A various change can be added.

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.
Rz _JIS measures the cross-sectional curve near the center of the outer peripheral surface of the cylindrical substrate using “Surfcom 1400D” (manufactured by Tokyo Seimitsu Co., Ltd., 2 μm R (60 °) pickup) at JIS'01 standard. It was obtained by roughness measurement performed under measurement conditions of a length of 4.0 mm, a cutoff of 0.8 mm (Gaussian), and a measurement speed of 0.06 mm / sec, and was calculated as a ten-point average roughness from this cross-sectional curve.
Moreover, (DELTA) L was measured as mentioned above from the cross-sectional curve obtained in the measurement of said cross-sectional curve.

<Example 1: Production Example 1 of cylindrical substrate>
A blank tube made of aluminum alloy with a length of 362 mm is mounted on a CNC lathe, and with a diamond sintered cutting tool, cutting is performed under the following conditions so that the outer diameter is 59.95 mm and the surface Rz _JIS is 0.75 μm. By doing so, a cylindrical substrate [1] was produced.
In the cutting of the cutting tool, the rotation speed of the main spindle of the lathe is set to 6000 rpm, and (the indicated speed related to the feeding speed of the cutting tool [μm / rotation (rev)], the moving distance of the cutting tool [mm]) is (300 μm / rev, 2 mm). ) → (310 μm / rev, 2 mm) → (320 μm / rev, 2 mm) → (310 μm / rev, 2 mm) → The program set to repeat (feed speed per 1 cm of moving distance of the bite base tube (average change frequency) : 5 times).
When ΔL on the outer peripheral surface of the cylindrical substrate [1] was measured, it was 40 μm.

<Example 2: Production example 2 of cylindrical substrate>
In the manufacturing example 1 of the cylindrical substrate, the cutting of the bite is performed by (indicated speed related to the bite feed speed [μm / rotation (rev)], bite moving distance [mm]) is (300 μm / rev, 2 mm) → (305 μm / rev, 2 mm) → (310 μm / rev, 2 mm) → (315 μm / rev, 2 mm) → (320 μm / rev, 2 mm) → (315 μm / rev, 2 mm) → (310 μm / rev, 2 mm) → (305 μm / Rev, 2 mm) → A cylindrical substrate [2] was produced in the same manner except that it was carried out by a program (average change frequency: 5 times) set to repeat.
The ΔL on the outer peripheral surface of the cylindrical substrate [2] was measured and found to be 35 μm.

<Example 3: Production example 3 of cylindrical substrate>
In the manufacturing example 1 of the cylindrical substrate, the cutting of the bite was performed by (indicated speed related to the bite feed speed [μm / rotation (rev)], bite moving distance [mm]) (300 μm / rev, 2.5 mm). ) → (305 μm / rev, 2 mm) → (310 μm / rev, 1.5 mm) → (315 μm / rev, 1 mm) → (320 μm / rev, 2.5 mm) → (315 μm / rev, 2 mm) → (310 μm / rev , 1.5 mm) → (305 μm / rev, 1 mm) → A cylindrical substrate [3] was obtained in the same manner except that it was performed by a program set to repeat (average frequency of change: 5.7 times). . It was 45 micrometers when (DELTA) L of the outer peripheral surface of this cylindrical base | substrate [3] was measured.

<Example 4: Production Example 4 of cylindrical substrate>
In the manufacturing example 1 of the cylindrical substrate, the cutting of the bite is performed by (indicated speed related to the bite feed speed [μm / rotation (rev)], bite moving distance [mm]) is (300 μm / rev, 2 mm) → (320 μm / rev, 2 mm) → A cylindrical substrate [4] was obtained in the same manner except that it was performed by a program (average change frequency: 5 times) set to repeat. It was 30 micrometers when (DELTA) L of the outer peripheral surface of this cylindrical base | substrate [4] was measured.

<Example 5: Production example 5 of cylindrical substrate>
A cylindrical substrate [5] was obtained in the same manner as in Production Example 4 of the cylindrical substrate, except that the spindle speed of the lathe for cutting by cutting was set to 3000 rpm. The average change frequency is 5 times. The ΔL of the outer peripheral surface of the cylindrical substrate [5] was measured and found to be 38 μm.

<Example 6: Production example 6 of cylindrical substrate>
In the manufacturing example 1 of the cylindrical substrate, the cutting of the bite was performed by (indicated speed related to the bite feed speed [μm / rotation (rev)], bite moving distance [mm]) (400 μm / rev, 1.47 mm). ) → (400 μm / rev, 2.32 mm) → (400 μm / rev, 1.68 mm) → (400 μm / rev, 2.53 mm) → (400 μm / rev, 1.89 mm) → (400 μm / rev, 2.75 mm) ) → (400 μm / rev, 2.10 mm) → (400 μm / rev, 2.96 mm) → A substrate [6] was produced.
The ΔL of the outer peripheral surface of the cylindrical substrate [6] was measured and found to be 8 μm.

<Comparative example 1: Production example 7 of cylindrical substrate>
Cylindrical substrate [7] was obtained in the same manner as in Production Example 1 of the cylindrical substrate, except that the cutting of the bite was performed with the bite feed speed fixed at 310 μm / rotation. The average change frequency is zero. The ΔL of the outer peripheral surface of this cylindrical substrate [7] was measured and found to be 3 μm.

<Example 7: Production example 8 of cylindrical substrate>
A base pipe made of aluminum alloy having a length of 362 mm is mounted on an analog lathe and is cut with a diamond sintered tool under the following conditions so that the outer diameter is 59.95 mm and the surface Rz _JIS is 0.75 μm. By doing so, a cylindrical substrate [8] was produced.
In the cutting of the tool, the main spindle speed of the lathe is set to 3160 rpm, and the feed speed of the tool relative to the tool moving distance (moving distance-feed speed) is 0.5 mm to 380 μm / rotation, 1.6 mm to 390 μm / rotation, Through a circuit combining a timer and a resistor so that 2.8 mm-380 μm / rotation, 1.1 mm-390 μm / rotation, 2.5 mm-380 μm / rotation, and 3.2 mm-390 μm / rotation are repeated. The voltage was input to the bite moving motor. The average change frequency is 5.1 times.
The ΔL of the outer peripheral surface of the cylindrical substrate [8] was measured and found to be 25 μm.

<Photoconductor Production Example 1>
(1) Formation of intermediate layer 1 part by mass of a binder resin represented by the following formula (N-1) is added to 20 parts by mass of a mixed solution of ethanol, n-propyl alcohol and tetrahydrofuran (volume ratio = 45: 20: 35). In addition, after stirring and dissolving, 4.2 parts by mass of rutile-type titanium oxide particles surface-treated with 5% by weight of methylhydrogenpolysiloxane were mixed, and this mixture was averaged using a bead mill. By using zirconia beads having a particle diameter of 0.5 mm and dispersing under conditions of a filling rate of 80%, a peripheral speed setting of 4 m / sec, and a mill residence time of 3 hours, an intermediate layer coating solution [1] was prepared. This intermediate layer coating solution [1] is filtered through a filter using a polypropylene filter medium having a filtration accuracy of 10 μm, and this is applied to the outer peripheral surface of the cylindrical substrate [1] by dip coating. Then, an intermediate layer [1] having a dry film thickness of 2 μm was formed on the cylindrical substrate [1] by drying at 120 ° C. for 20 minutes.

(2) Formation of charge generation layer Next, the following components were mixed and dispersed using a sand mill disperser to prepare a charge generation layer coating solution.
This charge generation layer coating solution was applied onto the intermediate layer [1] by a dip coating method to form a charge generation layer [1] having a dry film thickness of 0.3 μm.
Y-titanyl phthalocyanine (a titanyl phthalosine pigment having a maximum diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.3 ° in an X-ray diffraction spectrum by Cu-Kα characteristic X-ray)
20 parts by mass-polyvinyl butyral ("BX-1" (manufactured by Sekisui Chemical Co., Ltd.)) 10 parts by mass-700 parts by mass of methyl ethyl ketone-300 parts by mass of cyclohexanone

(3) Formation of charge transport layer Next, the following components were mixed and dissolved to prepare a charge transport layer coating solution.
The charge transport layer coating solution is applied onto the charge generation layer [1] by a dip coating method and dried at 120 ° C. for 70 minutes to form a charge transport layer [1] having a dry film thickness of 20 μm. A photoreceptor [1] was obtained.
-50 parts by mass of a charge transport material represented by the following formula (CTM)-100 parts by mass of polycarbonate resin "Iupilon-Z300" (manufactured by Mitsubishi Gas Chemical Company)-Antioxidant (2,6-di-t-butyl-4 -Methylphenol) 8 parts by mass / tetrahydrofuran / toluene (volume ratio 8/2) 750 parts by mass

<Photoconductor Production Examples 2 to 8>
In Photoconductor Production Example 1, Photoconductors [2] to [8] were prepared in the same manner except that the cylindrical substrates [2] to [8] were used instead of the cylindrical substrate [1]. Obtained.

[Image quality evaluation 1, 2]
An image forming apparatus “bizhub PRO C6501” (manufactured by Konica Minolta Business Technologies, Inc.) (machine using 780 nm laser light source) is mounted with any of the above photoreceptors [1] to [8], and a screen angle: 45 degrees, The number of screen lines: A test image was output through screen processing using a screen pattern of 212 lpi, and the obtained output image was evaluated for image quality according to the following evaluation criteria. The results are shown in Table 1.
Specifically, the test image is printed on the A3 size coated paper “POD gloss” with a density indication value of 0/255, 15/255, 31/255... It is an entire halftone image of black (Bk) output on a coat (100 g / m ² ) ”(manufactured by Oji Paper Co., Ltd.).
The image quality evaluation was performed on the worst-level image portion among image portions having different density instruction values.

(Image quality evaluation 1) Diagonal stripe density unevenness (interference lines)
-Evaluation criteria-
○: No oblique stripe density unevenness is observed.
Δ: Slight stripe-like density unevenness is slightly observed, but there is no problem in actual use.
X: Oblique stripe-like density unevenness is observed, and there is a problem in actual use.

(Image quality evaluation 2) Image scratches due to cutting defects-Evaluation criteria-
○: Image scratches are not seen at all.
Δ: Slight image scratches are observed, but there is no problem in actual use.
X: Image scratches are seen and there is a problem in actual use.

  As is apparent from Table 1, a good image was obtained when an image was formed using a photoreceptor (specific photoreceptor) comprising a cylindrical substrate produced by the production method according to the present invention. In the case where an image is formed using a photoconductor provided with a cylindrical substrate manufactured by cutting at a constant speed as in Comparative Example 1, the period of cutting irregularities of the cylindrical substrate and the period of the screen pattern Oblique streaky density unevenness estimated to be caused by the interference between the two occurred.

1, 1Y, 1M, 1C, 1Bk Photoconductor 1a Cylindrical substrate 1b Intermediate layer 1c Charge generation layer 1d Charge transport layer 1e Protective layer 1α Photosensitive layer 2Y, 2M, 2C, 2Bk Charging means 3Y, 3M, 3C, 3Bk Exposure means 4Y, 4M, 4C, 4Bk Developing means 5Y, 5M, 5C, 5Bk Primary transfer roller 5b Secondary transfer rollers 6Y, 6M, 6C, 6Bk Cleaning means 6b Cleaning means 7 Intermediate transfer unit 8 Housings 10Y, 10M, 10C, 10Bk Image forming unit 20 Paper feed cassette 21 Paper feed means 22A, 22B, 22C, 22D Intermediate roller 23 Registration roller 24 Fixing means 25 Paper discharge roller 26 Paper discharge tray 70 Intermediate transfer bodies 71-74 Support rollers 82L, 82R Support rail A Image Forming device main body P Image support SC Original image reading device

Claims (2)

A method for producing the cylindrical substrate in an electrophotographic photosensitive member having at least a photosensitive layer on the cylindrical substrate,
In a state where the circular pipe is rotated around its tube axis, the processing blade is set from one end to the other end of the processing area while bringing the processing blade into contact with the processing area on the outer peripheral surface of the circular pipe. A cutting process for moving in the direction of the pipe axis at the feed rate
A method of manufacturing a cylindrical substrate for an electrophotographic photosensitive member, wherein in the cutting step, the feed rate of the processing blade to the circular pipe material is changed a plurality of times. 2. The method for producing a cylindrical substrate for an electrophotographic photosensitive member according to claim 1, wherein the feed rate is changed at least three times per 1 cm of the moving distance of the processing blade with respect to the circular pipe material.

Images