JP2006208449A - Method for manufacturing photoreceptor and photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a photoreceptor controlled in the film thickness of an under coat layer formed on a conductive base having rough surface. <P>SOLUTION: The method has a process of coating the conductive base having ten-point average surface roughness of 0.7 to 12 μm with a coating liquid by using a dip coating method, and a process of making incident light incident on the formed film in a wet state perpendicularly to the film, detecting the light quantity of the spectral reflected light by subjecting the reflected light obtained by the interference of the light reflected on the surface of the film and the light reflected on the surface of the conductive base to spectral differentiation, determining the wavelength to maximize and minimize the spectral intensity of the spectra, and measuring the film thickness of the film by using the wavelength to maximize and minimize the spectral intensity of the spectra and the refractive index of the film. The photoreceptor is manufactured by controlling the conditions under which the coating liquid is coated based on the measured film thickness. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a photoreceptor and a photoreceptor.

  In recent years, as the speed of the electrophotographic process has been increased, a photoconductive photoconductor having good reliability and durability that can maintain high image quality even when used repeatedly is demanded.

  In the electrophotographic process, the photoconductive photosensitive member is worn out by being subjected to various mechanical, chemical, and electrostatic loads, and abnormal images are generated. Therefore, as a method for imparting charge (hole) blocking properties to the photoconductive photoconductor from the viewpoint of suppressing a decrease in image density and background smearing of the photoconductive photoconductor, there is a method between the conductive substrate and the photosensitive layer. A method of forming a light transmissive film is known.

  In general, when the film thickness of a light-transmitting film for adding a charge blocking function varies, the charge blocking characteristics of the photoconductive photoreceptor change, causing an abnormal image. For this reason, a method for measuring the film thickness of a light-transmitting film in a wet state is known in the manufacturing process.

  In Patent Documents 1 and 2, when the undercoat layer or the like is a light-transmitting film, the film thickness is sequentially measured in a wet state by an optical interference method, and the coating speed is automatically controlled by feeding back the measurement result. A method for suppressing thickness variation is disclosed. However, with this method, it is difficult to measure the film thickness of the light-transmitting film because good reflected light cannot be obtained from the light-transmitting film formed on the conductive substrate having a rough surface. In addition, since the light receiving part must be installed in the vicinity of the wet film, there is a problem that the light receiving part becomes dirty during coating and measurement becomes impossible.

  Patent Documents 3 and 4 disclose a manufacturing method in which the thickness of the undercoat layer is accurately measured even when the undercoat layer is a thin film, and the measurement result is reflected in the manufacturing process. However, with this method, it is difficult to measure the film thickness because good reflected light cannot be obtained from a thin film formed on a conductive substrate having a rough surface. In addition, the light receiving portion must be close to the undercoat layer.

In Patent Document 5, in a method for producing an electrophotographic photosensitive member by a dip coating method, a wet film thickness is measured by a light interference method using light having a wavelength of 500 nm or more, and a wet film thickness measurement result is immediately applied. A method of reflecting the process with high accuracy is disclosed. However, with this method, it is difficult to measure the wet film thickness of a light-transmitting film formed on a conductive substrate having a rough surface.
JP-A-4-336540 JP-A-6-130683 Japanese Patent Laid-Open No. 11-184104 JP-A-11-201730 Japanese Patent Laid-Open No. 2001-27815

  In view of the above-described problems of the conventional technology, the present invention provides a method for producing a photoreceptor capable of producing a photoreceptor in which the thickness of an undercoat layer formed on a conductive substrate having a rough surface is controlled, and It is an object of the present invention to provide a photoconductor manufactured using the method for manufacturing the photoconductor.

  The invention according to claim 1 is a method of applying a coating liquid to a conductive substrate having a ten-point average roughness of 0.7 μm or more and 1.2 μm or less using a dip coating method in the method of manufacturing a photoreceptor. The incident light is incident on the wet film formed by applying the coating liquid perpendicularly to the film, and the light reflected from the surface of the film is reflected from the surface of the conductive substrate. The reflected light obtained by interference with the reflected light is dispersed to detect the amount of the reflected reflected light, and when calculating the spectral spectrum intensity from the light amount, the dynamic range of the spectral spectrum intensity is expanded. Determining the wavelength at which the spectral spectrum intensity is minimum and maximum, and measuring the film thickness of the film using the wavelength at which the spectral spectrum intensity is minimum and maximum and the refractive index of the film, Membrane The photosensitive member is manufactured by controlling the condition for applying the coating liquid based on the thickness.

  According to the invention described in claim 1, using a dip coating method, a step of applying a coating liquid to a conductive substrate having a ten-point average roughness of 0.7 μm or more and 1.2 μm or less; Incident light is incident on the wet film formed by application perpendicularly to the film, and interference between the light reflected on the surface of the film and the light reflected on the surface of the conductive substrate The spectral spectrum intensity is obtained by spectroscopically analyzing the reflected light obtained by detecting the light intensity of the spectrally reflected reflected light and expanding the dynamic range of the spectral spectral intensity when calculating the spectral spectral intensity from the light quantity. Determining the wavelength at which the spectral spectrum intensity is minimum and maximum, and measuring the film thickness of the film using the wavelength at which the spectral spectrum intensity is minimum and maximum and the refractive index of the film, Based on the paint Since the photoconductor is manufactured by controlling the conditions for applying the liquid, a photoconductor capable of manufacturing a photoconductor in which the thickness of the undercoat layer formed on the conductive substrate having a rough surface is controlled. A manufacturing method can be provided.

  According to a second aspect of the present invention, in the method for manufacturing a photoreceptor according to the first aspect, an objective lens having a diameter of 6 mm to 30 mm is provided so that a distance from the surface of the film is 40 mm to 70 mm. It is characterized by that.

  According to the second aspect of the present invention, since the objective lens having a diameter of 6 mm or more and 30 mm or less is provided so that the distance from the surface of the film is 40 mm or more and 70 mm or less, the film thickness can be accurately measured. it can.

  According to a third aspect of the present invention, in the method for manufacturing a photosensitive member according to the first or second aspect, the conductive substrate has a cylindrical shape or a belt shape, and extends along an axis direction of the conductive substrate. The film thickness distribution of the film is obtained by measuring the film thickness of the film.

  According to the invention described in claim 3, the conductive substrate has a cylindrical shape or a belt shape, and the film thickness of the film is measured along the axial direction of the conductive substrate. Since the film thickness distribution is obtained, the uniformity of the film thickness of the undercoat layer can be improved.

  According to a fourth aspect of the present invention, in the method for manufacturing a photoreceptor according to any one of the first to third aspects, the condition for applying the coating liquid is a coating speed of the coating liquid. To do.

  According to the invention described in claim 4, since the condition for applying the coating liquid is the coating speed of the coating liquid, the film thickness of the undercoat layer can be controlled.

  According to a fifth aspect of the present invention, in the method for manufacturing a photoreceptor according to any one of the first to third aspects, the condition for applying the coating liquid is a physical property of the coating liquid. .

  According to the invention described in claim 5, since the condition for applying the coating liquid is the physical property of the coating liquid, the thickness of the undercoat layer can be controlled.

  According to a sixth aspect of the present invention, a photoconductor is manufactured by the method for manufacturing a photoconductor according to any one of the first to fifth aspects.

  According to the invention described in claim 6, since it is manufactured by the method for manufacturing a photoreceptor according to any one of claims 1 to 5, the undercoat layer is formed on a conductive substrate having a rough surface. It is possible to provide a photoconductor having a controlled film thickness.

  According to the present invention, a method for manufacturing a photoconductor capable of manufacturing a photoconductor in which the thickness of an undercoat layer formed on a conductive substrate having a rough surface is controlled, and a method for manufacturing the photoconductor are used. Thus, a photoconductor manufactured in the above manner can be provided.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  In the present invention, the step of applying the coating solution for the undercoat layer to the conductive substrate having a ten-point average roughness of 0.7 to 1.2 μm using the dip coating method is performed by a known coating method and coating method. An apparatus can be used.

  In the present invention, the step of measuring the film thickness is performed by applying spectral light having a desired wavelength region to the wet undercoat layer formed by applying the undercoat layer coating liquid, perpendicular to the undercoat layer. The thickness of the wet undercoat layer using the reflected light obtained by the interference between the light reflected from the surface of the wet undercoat layer and the light reflected from the surface of the conductive substrate. It is a process of measuring. The desired wavelength region means a wavelength region that enables film thickness measurement, and is determined by the material of the undercoat layer.

  The reflected light obtained in this way is dispersed to detect the amount of the reflected reflected light. Furthermore, when calculating the spectral spectrum intensity from the amount of light, the wavelength at which the spectral spectrum intensity becomes minimum and maximum is obtained by expanding the dynamic range of the spectral spectrum intensity, the wavelength at which the spectral spectrum intensity becomes minimum and maximum, and the wet state The thickness of the wet undercoat layer is measured using the refractive index of the undercoat layer. Furthermore, by controlling the coating conditions based on the measured film thickness, it is possible to obtain a photoreceptor in which the film thickness of the undercoat layer formed on the conductive substrate having a rough surface is controlled.

  FIG. 1 shows a circulation type dip coating apparatus for applying a coating solution for an undercoat layer to a conductive substrate by a dip coating method. Using the elevator 18, the conductive substrate 17 can be immersed in the undercoat layer coating solution, and then pulled up to apply the undercoat layer coating solution. The circulation type dip coating apparatus is supplied with a coating solution for the undercoat layer. In the storage tank 15, the coating solution for the undercoat layer is diluted with a solvent evaporated during coating or a heat insulating jacket (not shown). The temperature is adjusted. At this time, the stirring blade 14 is rotated by the stirring motor 16 so that the coating liquid of the undercoat layer in the storage tank 15 is made uniform. The undercoat layer coating liquid in the storage tank 15 is supplied to the coating tank 11 through the filter 12 by the circulation pump 13. The circulation pump 13 preferably has a structure that hardly applies stress to the coating liquid of the undercoat layer. Specifically, a pump that is difficult to apply a shearing force, such as a uniaxial eccentric screw pump, can be used. The filter 12 plays a role of filtering agglomerates and the like generated in the staying portion of the dispersion liquid in the circulation device. As the effective pore size of the filter 12 is smaller, the filtration performance is improved. However, since the circulation is continuous, a load is applied to the circulation pump 13. For this reason, there exists an appropriate range in the effective hole diameter of the filter 12, and generally it is preferable that it is 1-10 micrometers. The filter 12 is made of a material that is resistant to the coating liquid for the undercoat layer. Of the coating liquid of the undercoat layer supplied to the coating tank 11, the portion exceeding the capacity of the coating tank 11 overflows at the upper end of the coating tank 11 and is returned to the storage tank 15. Regarding the circulation, the circulation may be performed at all times, but since the vibration of the circulation pump 13 or the like may be picked up to cause a coating film defect, the circulation may be stopped while the conductive substrate 17 is immersed. preferable. Since the coating liquid for the undercoat layer is made uniform, it is preferable to continue the circulation until just before the conductive substrate 17 is immersed in the coating liquid for the undercoat layer. The circulation flow rate is determined by the liquid feeding capacity of the circulation pump 13, the degree of pressure increase in the circulation system, etc., but the coating liquid of the undercoat layer with a volume greater than the volume of the conductive substrate 17 is applied. The flow rate is preferably such that the liquid can be fed between tacts. Thereby, all the coating liquids of the undercoat layer in the coating tank 11 are replaced, and a good undercoat layer can be formed without leaving a history of the applied coating liquid.

  The conductive substrate preferably has a cylindrical shape or a belt shape. The aluminum base tube, a metal substrate such as a nickel belt formed by the same method as plating, and a polyester film are subjected to aluminum vapor deposition or a conductive resin coating. And various materials such as plastic belts. Among these, the aluminum base tube is preferably used because it can be subjected to surface processing such as cutting, ironing, and drawing.

  The material constituting the undercoat layer is not particularly limited as long as it is a material that transmits spectral light used for film thickness measurement, but is roughly classified into an organic material and an inorganic material.

  Examples of the organic material include resins such as oligomers, thermoplastic resins, and thermosetting resins. Such resins may be added with additives such as pigments, plasticizers, antioxidants, and conductive agents. Such a material needs to be optically transparent, and the additive is preferably dispersed in the resin. Specifically, polyamide resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester resin, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, poly Vinyl acetate, polyvinylidene chloride, polyarate, phenoxy resin, polycarbonate resin, cellulose acetate resin, ethyl cellulose, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, polyvinyl alcohol, poly (N-vinylcarbazole), acrylic resin, silicone resin, epoxy resin, A melamine resin, a urethane resin, a phenol resin, an alkyd resin, etc. are mentioned.

  Examples of inorganic materials include metal oxides such as silicon dioxide, glassy networks of metal oxides described in JP-A-3-191361, and materials obtained by thermally cross-linking organometallic compounds.

  The coating liquid for the undercoat layer may be a liquid in which the above materials are dissolved or dispersed in a solvent.

  The film thickness of the undercoat layer can be controlled by the physical properties of the undercoat layer coating liquid or the coating speed (speed at which the conductive substrate 17 is pulled up).

  Under the conditions that the temperature of the undercoat layer coating liquid, the temperature and humidity of the environment, the diameter of the conductive substrate, etc. are the same, and the physical properties of the undercoat layer coating liquid are constant, the thickness of the undercoat layer is , And changes depending on the coating speed of the coating solution for the undercoat layer. Specifically, the film thickness increases as the coating speed of the undercoat layer coating liquid increases.

  Under the conditions that the temperature of the undercoat layer coating liquid, the temperature and humidity of the environment, the diameter of the conductive substrate, etc. are the same, and the coating speed of the undercoat layer coating liquid is constant, the thickness of the undercoat layer Changes depending on the physical properties of the coating liquid of the undercoat layer. Specifically, as the viscosity of the coating liquid for the undercoat layer increases, the film thickness increases. The solid content concentration and the solvent contribute to the viscosity of the coating liquid of the undercoat layer.

  In order to control the film thickness of the undercoat layer, the film thickness in a wet state is measured, and the film thickness after dry curing is estimated based on the measurement result. Furthermore, based on this estimation result, the physical properties or coating speed of the coating liquid for the undercoat layer is adjusted to control the film thickness.

  In order to estimate the film thickness after drying and curing, a correlation between the film thickness in the wet state and the film thickness after drying and curing is obtained in advance. For this reason, it apply | coats on various conditions and the film thickness of a wet state and the film thickness after dry-curing are measured.

  At this time, the film thickness in the wet state changes with time during drying. However, if the physical properties of the coating liquid in the undercoat layer and the drying conditions are constant, the behavior of the change in the wet film thickness is almost the same. Therefore, the film thickness in a wet state may be measured after a certain time has elapsed. The film thickness in a wet state can be measured immediately after coating, but the measurement accuracy is improved when measured after drying for a certain period of time.

  The drying time may be a time when the estimation result based on the measured wet film thickness can be fed back to the next application. For this reason, what is necessary is just the time from immediately after application to the next application being performed, and is usually 1 to 30 minutes, and preferably 2 to 3 minutes. When the drying time is shorter than 1 minute, since the solvent is not sufficiently vaporized, the variation in the film thickness in the wet state increases. Moreover, if it is longer than 30 minutes, the productivity decreases.

  When measuring the film thickness of the undercoat layer in a wet state, it is necessary to carry out so as not to damage the coating film. Further, in order to reduce measurement errors due to solvent vaporization, it is necessary to perform measurement in a short time. In the present invention, 30 points can be measured at a pitch of 10 mm in the axial direction of a conductive substrate having a cylindrical shape or a belt shape in about 15 to 45 seconds.

  In order to increase the measurement accuracy of the film thickness of the undercoat layer in the wet state, it is preferable to obtain a film thickness distribution by measuring multiple points at a pitch of 10 mm in the axial direction of a conductive substrate having a cylindrical shape or a belt shape. It is possible to control the film thickness with high accuracy by estimating the film thickness after drying and curing corresponding to the film thickness in the wet state from the film thickness distribution, and controlling the physical properties or coating speed of the coating liquid of the undercoat layer. it can.

  The wet undercoat layer thus formed is heat-dried as necessary.

  The thickness of the undercoat layer is preferably 0.3 to 2.0 μm, but in order to improve the function as the charge blocking layer and the light shielding effect on the conductive substrate, the thickness is 0.5 μm or more. Preferably there is.

  FIG. 2 shows an example of a film thickness measuring apparatus for measuring the film thickness of the wet undercoat layer. The film thickness measuring apparatus includes a light source 21, a fiber probe 22 as a transmission optical system, and an objective lens 23 as a focusing optical system. The light source 21 emits spectrum light. The emitted spectrum light is transmitted to the emission part of the fiber probe 22 by the radiated light transmission fiber 22a, and the measured object in which the wet undercoat layer is formed on the conductive substrate from the emission part of the fiber probe 22. It is injected towards 20. The emitted spectral light is collected by the objective lens 23 onto the wet undercoat layer of the object to be measured 20 and is incident thereon. The reflected light obtained by the interference between the light reflected on the surface of the wet undercoat layer and the light reflected on the surface of the conductive substrate is received by the fiber probe 22 via the objective lens 23 and reflected light. It is transmitted by the transmission fiber 22b. The transmitted reflected light is split by the spectroscopic means 24, and the amount of the reflected reflected light is detected by the spectral intensity detecting means 25. When calculating the reflectance from the amount of light, the calculation means 26 uses a standard sample for calibrating the spectral spectrum intensity of the reflected light, normalizes the spectral characteristics of the light source and the light receiving element, and calculates the dynamic range of the spectral spectrum intensity. To enlarge. Thereby, the wavelength at which the spectral spectrum intensity is minimum and maximum is obtained. Further, the film thickness of the wet undercoat layer is calculated using these wavelengths and the refractive index of the wet undercoat layer.

  In this case, the objective lens 23 having a diameter of 6 mm or more and 30 mm or less is provided so that the distance from the surface of the wet undercoat layer is 40 mm or more and 70 mm or less, and spectral light is applied to the wet undercoat layer. It is preferable to make it enter perpendicularly.

  The numerical aperture of the objective lens 23 is preferably 0.05 or more. In the embodiment, an achromatic lens having a lens diameter of 12.5 mm and a focal length of 30 mm is used. The objective lens 23 is fixed to the end of the lens barrel 27, and the other end of the lens barrel 27 holds the end on the emission side of the fiber probe 22. In the embodiment, the distance between the objective lens 23 and the surface of the object 20 to be measured is 60 mm, and the distance between the objective lens 23 and the end portion on the emission side of the fiber probe 22 is 60 mm.

  The light source 21 is preferably a halogen-tungsten lamp, and can emit spectrum light in a wide wavelength range from the visible region to the near infrared region.

  As shown in FIG. 3, the end of the emission side of the fiber probe 22 is preferably configured so that the reflected light transmission fiber 22b is surrounded by the radiated light transmission fiber 22a. In the embodiment, the light emitted from the fiber probe 22 is collected by the objective lens 23 as a light spot having a diameter of 0.4 mm on the surface of the object 20 to be measured. That is, the diameter of the end face of the radiated light transmission fiber 22a is 0.2 mm. If the bundle of radiated light transmission fibers 22a shown in FIG. Using (= 60/60 = 1), the diameter of the light spot is 0.4 mm.

  The spectroscopic means 24 is preferably a diffraction grating, and specifically includes a fixed Zernitana diffraction grating having a spectral region of 380 to 850 nm and a resolution of 1.2 nm / point. As the spectroscopic means 24, a prism or a spectral filter can be used in addition to the diffraction grating.

  The spectral intensity detection means 25 is preferably a line sensor, and examples include a sensor having sensitivity in the range from the visible range to 1050 nm and having 512 light receiving elements. As the spectral intensity detection means 25, a silicon photodiode array can be used in addition to the line sensor.

The principle of measuring the thickness of the undercoat layer will be described using the photoconductor shown in FIG. 4 as an example. Here, the photoreceptor is considered as a system comprising a conductive substrate 41 having a refractive index of n ₀ and a subbing layer 42 having a film thickness of d and a refractive index of n ₁ formed thereon. Is perpendicularly incident on the surface of the undercoat layer 42.

  Part of the collected spectral light is reflected on the surface of the undercoat layer 42, and part of the light is incident on the undercoat layer 42 and reflected on the surface of the conductive substrate 41. The reflected light is split by the spectroscopic means, and the light intensity of the split reflected light is detected by the spectral intensity detecting means.

In the region where the wavelength is larger than 400 nm, the appropriate adjacent maximum and minimum of the spectral spectrum intensity are selected, and the wavelengths giving the maximum and minimum are λ _2m and λ _{2m + 1} , respectively. m is the order of interference and can be determined as appropriate.

Between the film thickness d of the undercoat layer 42, the refractive index n ₁ and the order of interference m,
2m = 4n ₁ d / λ _2m
2m + 1 = 4n ₁ d / λ _{2m + 1}
Since the relationship is established, if m is deleted,
n ₁ d = λ _2m · λ _{2m +} 1/4 (λ _2m −λ _{2m + 1} )
The relationship is obtained.

Therefore, when λ _2m and λ _{2m + 1} are given, the optical film thickness n ₁ d of the undercoat layer 42 is obtained. Furthermore, when the refractive index n ₁ is given, the film thickness d of the undercoat layer 42 is
d = λ _2m · λ _{2m + 1} / 4n ₁ (λ _2m −λ _{2m + 1} ) (1)
Can be computed as

The refractive index n ₁ is uniquely determined when the material of the undercoat layer 42 is determined, and its spectral characteristics, that is, the change in refractive index depending on the wavelength (hereinafter referred to as spectral refractive index) is previously stored in the calculation means. It can be stored as a table or a function of wavelength. Accordingly, the film thickness d of the undercoat layer 42 can be calculated from λ _2m , λ _{2m + 1} and n ₁ according to the equation (1).

  At this time, as is clear from the equation (1), when calculating the film thickness of the undercoat layer 42, the absolute value of the spectral spectrum intensity is not necessary, and if the wavelength that gives the maximum and minimum can be obtained with high accuracy, The film thickness d of the undercoat layer 42 can be measured using the spectral refractive index of the undercoat layer 42. Therefore, in order to increase the accuracy of the wavelength that gives the maximum and minimum spectral spectrum intensity, the dynamic range of the spectral spectrum intensity is expanded.

In general, the spectrophotometer, spectral reflectance meter, optical interference film thickness meter, etc. directly measure the amount of light reflected from the sample. To obtain the spectral spectrum intensity, a standard sample with a known spectral spectrum intensity is used. Must be measured and calibrated in advance. Thus, the spectral spectrum intensity R (λ) of the sample is
R (λ) = (I _s (λ) −I _d (λ)) / (I _r (λ) −I _d (λ)) · r (λ) (2)
Can be calculated as Here, I _s (λ) is the amount of reflected light from the sample, I _d (λ) is the dark current component of the light receiver, I _r (λ) is the amount of reflected light from the standard sample, and r (λ) is It means the spectral intensity of the standard sample.

In the present invention, it is preferable to expand the dynamic range of R (λ) by reducing the amount of reflected light of the standard sample. Specifically, a standard sample having I _r2 (λ) smaller than I _r1 (λ) is prepared for a standard sample having I _r1 (λ) and r ₁ (λ), and I _r2 (λ) and R (λ) is calculated using r ₁ (λ).

That is, the calculating means expands the dynamic range of the spectral spectrum intensity when calculating the spectral spectrum intensity from the amount of reflected light detected by the spectral intensity detecting means. Further, the respective wavelengths λ _{2m + 1} and λ _2m that give the minimum and maximum are obtained by differential operation etc. with respect to the obtained spectral spectrum intensity, and the film of the undercoat layer 42 is determined based on the refractive index n ₁ of the undercoat layer 42. The thickness d is calculated according to equation (1).

  In FIG. 5, an example of the result measured using the film thickness measuring apparatus is shown. Here, the amount of reflected light, which is measurement data detected by the spectrum intensity detection means, is calculated as a continuous spectral spectrum intensity in the calculation by a non-linear least square method (for example, a curve fit algorithm such as the simplex method) in the calculation means. It is a thing. Note that the spectral spectrum intensity is finite over a wavelength region of 400 to 850 nm, and vibrates as the wavelength changes.

  When the film thickness of the undercoat layer is measured under such conditions, it can be measured accurately with a resolution of 0.01 μm or less.

  When the undercoat layer is formed on a conductive substrate having a 10-point average roughness of 0.7 to 1.2 μm, the thickness of the undercoat layer is smaller than the 10-point average roughness. Can be measured.

  The calculation of the film thickness of the undercoat layer requires a spectral refractive index. However, the spectral refractive index of the material used as the undercoat layer may be stored in the calculation means so as to be usable.

  In order for the photoreceptor to exhibit an appropriate function, as described above, the undercoat layer needs to have an appropriate film thickness, and measurement of the film thickness is necessary at the time of manufacture.

  If the film thickness of the undercoat layer varies, as described above, the charge blocking characteristics of the photoconductor may change, which may cause an abnormal image. Can be measured, the film thickness can be grasped during coating, and a high-quality photoreceptor can be obtained by adjusting the physical properties or coating conditions of the coating solution for the undercoat layer.

  At this time, after the film thickness of the undercoat layer in the wet state is measured, the calculation means corresponds to the film thickness in the wet state from the correlation between the film thickness in the wet state and the film thickness after dry curing. The film thickness after drying and curing is estimated, and conditions for applying the coating liquid for the undercoat layer are determined so that a desired film thickness can be obtained in the next application step. At this time, it is preferable to control the physical properties or coating speed of the coating liquid for the undercoat layer.

  When controlling the physical properties of the coating liquid for the undercoat layer, the viscosity of the coating liquid is controlled by adjusting the solid content concentration and the solvent. When controlling the coating speed, the elevator motor is controlled. Thereby, the next application | coating process can be implemented on suitable application conditions.

  Thus, by measuring the wet film thickness of the undercoat layer and controlling the physical properties or coating speed of the undercoat layer coating liquid in the next coating step, the wet film thickness of the undercoat layer can be controlled. Can be adjusted. According to such a manufacturing method, the wet film thickness of the undercoat layer formed on the conductive substrate having a rough surface can be accurately measured in a non-contact / non-destructive manner, and immediately the next coating step. It is possible to adjust the film thickness. As a result, it is possible to obtain a photoreceptor having an undercoat layer having a proper and stable film thickness.

  In the method for producing a photoreceptor of the present invention, a step of drying and curing the undercoat layer after the step of measuring the film thickness, and applying and drying and curing a coating solution for an intermediate layer in which fine particles are dispersed on the surface of the undercoat layer And a step of forming a photosensitive layer by applying a coating solution for the photosensitive layer on the intermediate layer, followed by drying and curing.

  FIG. 4 shows an example of the configuration of the photoreceptor of the present invention. An undercoat layer 42, an intermediate layer 43, and a photosensitive layer 44 are laminated on the conductive substrate 41. Here, the photosensitive layer 44 includes a charge generation layer 44a and a charge transport layer 44b. The undercoat layer 42 has a function for imparting charge (hole) blocking properties to the photoreceptor as a means for improving electrical insulation from the viewpoint of suppressing image density reduction and background staining. The intermediate layer 43 has a function as a binder for bonding and fixing the photosensitive layer to the undercoat layer 42, and contains fine particles of pigment in order to suppress adverse effects such as uneven charging. The charge generation layer 44a is a layer that generates positive and negative charge pairs by irradiation with light of a specific wavelength, and the charge transport layer 44b is a surface of the photosensitive layer that has a predetermined polarity out of the charges generated in the charge generation layer 44a. It has a function to transport to.

  The thickness of the undercoat layer, intermediate layer, charge generation layer, and charge transport layer is preferably about 0.3 to 2.0 μm, 2 to 6 μm, 1 μm or less, and about 15 to 35 μm, respectively.

  When an optical scanning device using laser light is used as the exposure means in the image forming apparatus, the laser light is reflected from the surface of the conductive substrate and the surface of the intermediate layer and interferes inside the photosensitive layer, and an interference pattern is formed on the image. May appear. In order to avoid such a problem, the surface of the conductive substrate is roughened by cutting or the like, or fine particles of pigment are dispersed in the intermediate layer and diffusely reflected. The ten-point average roughness of the conductive substrate is preferably about 0.7 to 1.2 μm.

  The intermediate layer has a configuration in which particles and fine particles are dispersed in a binder resin. As the binder resin, thermoplastic resins such as polyvinyl alcohol, nitrocellulose, polyamide resin, and polyvinyl chloride, thermosetting resins such as polyurethane resin, alkyd-melamine resin, and the like can be used. As the particles, titanium oxide, aluminum oxide, tin oxide, zinc oxide, zirconium oxide, magnesium oxide, silica, and surface treated products thereof can be used, but titanium oxide is preferable in terms of dispersibility and electrical characteristics. is there. As the titanium oxide, both a rutile type and an anatase type can be used. As the colorless and transparent pigment, a rutile type titanium oxide having a large refractive index is preferable. In consideration of increasing the surface reflectance, the fine particles are preferably colorless and transparent pigments that are white in a powder state and have a back surface hiding power (light shielding power against a conductive substrate). If it is colorless and transparent, there is no selective wavelength absorption, so that surface reflection and internal multiple refraction are possible in the entire visible region.

  As a method for forming the intermediate layer, there is a method in which a coating liquid obtained by dispersing particles in a solution in which a binder resin is dissolved by means of a ball mill, a sand mill or the like is applied on the undercoat layer and dried. Can be mentioned.

  The charge generation layer is a layer mainly composed of a charge generation material, and a binder resin is added as necessary. As the charge generation material, both inorganic materials and organic materials can be used.

  Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium compounds such as selenium-tellurium, selenium-tellurium-halogen, and selenium-arsenic, and amorphous silicon. In amorphous silicon, dangling bonds in which dangling bonds are terminated with hydrogen atoms or halogen atoms, or those in which boron atoms, phosphorus atoms or the like are doped can be suitably used.

  Examples of the organic material include phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, An azo pigment having a dibenzothiophene skeleton, an azo pigment having a fluorenone skeleton, an azo pigment having an oxadiazole skeleton, an azo pigment having a bisstilbene skeleton, an azo pigment having a distyryloxadiazole skeleton, an azo having a distyrylcarbazole skeleton Pigment, perylene pigment, anthraquinone or polycyclic quinone pigment, quinone imine pigment, diphenylmethane and triphenylmethane pigment, benzoquinone and naphthoquinone pigment, cyanine and azomethine face It can be used indigoid pigment, a known material such as vicinal benzimidazole pigments.

  These charge generation materials can be used alone or as a mixture of two or more.

  Examples of the binder resin include polyamide resin, polyurethane resin, epoxy resin, polyketone, polycarbonate resin, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly (N-vinylcarbazole), and polyacrylamide. It is done. These binder resins can be used alone or as a mixture of two or more.

  If necessary, a charge transport material may be added to the charge generation layer.

  The method for forming the charge generation layer is roughly classified into a vacuum thin film manufacturing method and a casting method from a solution dispersion system. Examples of the vacuum thin film production method include a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, and the like, and a charge generation layer is formed using an inorganic material or an organic material. be able to. As a method for forming a charge generation layer by a casting method, an inorganic material or an organic material is optionally combined with a binder resin in a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone, ball mill, attritor, sand mill, etc. A method of appropriately diluting a dispersion liquid obtained by dispersing using, followed by coating and drying.

  As a coating method, a dip coating method, a spray coating method, a beat coating method, or the like can be used. The thickness of the charge generation layer is preferably 1 μm or less, more preferably about 0.01 to 1 μm, and particularly preferably 0.05 to 0.5 μm.

  The charge transport layer is a layer mainly composed of a charge transport material, and a binder resin is added as necessary. As a method for forming the charge transport layer, a liquid in which a charge transport material is dissolved or dispersed in a solvent such as tetrahydrofuran, dioxane, toluene, chlorobenzene, dichloroethane, methylene chloride, cyclohexanone, and a binder resin as necessary. The method of apply | coating and drying is mentioned. A plasticizer, a leveling agent, etc. can also be added to a charge transport layer as needed.

  Charge transport materials include hole transport materials and electron transport materials.

  Examples of electron transport materials include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8- Trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, 3,5- Examples thereof include dimethyl-3 ′, 5′-di-t-butyl-4,4′-diphenoquinone. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of hole transport materials include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis- (4-dibenzylaminophenyl) propane, styryl. Anthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzfuran derivatives, benzimidazole derivatives, thiophone derivatives, and the like can be given. These hole transport materials can be used alone or as a mixture of two or more.

  As binder resin, polycarbonate resin such as bisphenol A type and bisphenol Z type, polyester resin, methacrylic resin, acrylic resin, polyethylene, polyvinyl chloride, polyvinyl acetate, polystyrene, phenol resin, epoxy resin, polyurethane resin, polychlorinated resin Examples include vinylidene, alkyd resin, silicone resin, polyvinyl carbazole, polyvinyl butyral, polyvinyl holmar, polyacrylate, polyacrylamide, and phenoxy resin. These binder resins can be used singly or as a mixture of two or more kinds. The amount of the binder resin added is preferably 0 to 150 parts by weight with respect to 100 parts by weight of the charge transport material.

  As the binder resin, a polymer charge transport material having a function as a charge transport material can also be used. Polymer charge transport materials include polymers having a carbazole ring in at least one of the main chain and the side chain, polymers having a hydrazone structure in at least one of the main chain and the side chain, a styrene polymer, a main chain and a side chain. Examples thereof include a polymer having a tertiary amine structure on at least one side. The film thickness of the charge transport layer is preferably about 15 to 35 μm, but the allowable range is about 5 to 100 μm.

  The photosensitive layer may be formed as a single layer. In this case, the photosensitive layer contains a charge generation material and a charge transport material. At this time, the materials described above can be used as the charge generation material and the charge transport material.

  An antioxidant may be added to the photoreceptor of the present invention for the purpose of suppressing a decrease in sensitivity and an increase in residual potential. The antioxidant may be added to any layer containing an organic substance, but a particularly good effect can be obtained by adding it to a layer containing a charge transporting substance.

  As the conductive substrate, a cut aluminum base tube (tube whose peripheral surface was roughened by cutting) having a tube diameter of 100 mm and a ten-point average roughness of 0.9 μm was used.

  A coating liquid for an undercoat layer comprising 4 parts by weight of alcohol-soluble nylon Amilan CM8000 (manufactured by Toray Industries, Inc.), 70 parts by weight of methanol, and 30 parts by weight of n-butanol was prepared, and the circulation type dip coating apparatus shown in FIG. And applied to a cut aluminum blank.

  When applying the coating liquid for the undercoat layer, data relating to the coating liquid for the undercoat layer was previously input to the arithmetic processing unit. Specifically, the wet film thickness after 2 minutes from the coating with respect to the coating speed of the undercoat layer and the film thickness after drying and curing were measured, and the correlation between them was input. Thereafter, the film thickness of the undercoat layer finally obtained is set to 0.7 μm, the film thickness in a wet state is measured when 2 minutes have elapsed after the application of the undercoat layer coating liquid, The coating speed was determined and reflected in the coating speed in the next coating process, and 50 continuous samples were produced.

  The film thickness measurement apparatus shown in FIG. 2 is used to measure the film thickness in the wet state and the film thickness after dry curing, and the measurement conditions are optimum for the film thickness in the wet state and the film thickness after dry cure, respectively. A condition was set. In particular, the spectral refractive index data used for film thickness measurement has been prepared as a database by measuring actual target values.

  Next, after drying with the touch, an undercoat layer was formed by performing heat drying at 130 ° C. for 10 minutes. When the film thickness of the undercoat layer after drying and curing was measured, the film thickness obtained was within the range of 0.7 ± 0.1 μm. A part of the result is shown in Table 1.

表中、○は、品質に問題がないことを意味する。

In the table, ○ means that there is no problem in quality.

As a comparative example, a sample was prepared under the same conditions as described above except that the coating speed of the coating solution for the undercoat layer was fixed at 10 mm / second. A part of the results are shown in Table 2.

表中、×は、所定の品質を満足しないことを意味する。

In the table, x means that the predetermined quality is not satisfied.

  As described above, when the coating speed is not controlled, when the number of production increases, the thickness of the undercoat layer increases, and when the number of production exceeds 20, the predetermined quality cannot be achieved. The physical properties of the coating liquid for the undercoat layer change with time, so that it is necessary to reduce the coating speed as the number of production increases. For this reason, the film thickness of the undercoat layer could be controlled by providing a step of measuring the film thickness as in the example and adjusting the coating speed based on the measured film thickness.

  Furthermore, a photoconductive photoconductor was manufactured by forming an intermediate layer, a charge generation layer, and a charge transport layer as follows.

  As colorless transparent pigment, 70 parts by weight of titanium oxide having an average particle diameter of 0.25 μm, 15 parts by weight of alkyd resin Beckolite M6401-50-S (manufactured by Dainippon Ink & Chemicals, Inc.) of 50% by weight, 60% by weight of A mixture of 10 parts by weight of melamine resin Superbecamine L-121-60 (Dainippon Ink Chemical Co., Ltd.) and 100 parts by weight of methyl ethyl ketone was dispersed with a ball mill for 72 hours to prepare an intermediate layer coating solution. The intermediate layer coating solution was applied to the cut aluminum base tube on which the undercoat layer was formed by dip coating, and dried at 130 ° C. for 20 minutes. In this way, an intermediate layer having a thickness of 3.5 μm was formed.

  In a solution in which 4 parts by weight of polyvinyl butyral BM-2 (manufactured by Sekisui Chemical Co., Ltd.) is dissolved in 150 parts by weight of cyclohexanone, a chemical structural formula

で示されるトリスアゾ系顔料１０重量部を添加し、ボールミルで７２時間分散させた後、シクロヘキサノン２１０重量部を加えて３時間分散させ、９００ｎｍ以下に吸収ピークを有する電荷発生層の塗液を作製した。浸漬塗工法により、中間層上に電荷発生層の塗液を塗布し、１３０℃で１０分間乾燥して、膜厚０．２μｍの電荷発生層を形成した。

10 parts by weight of a trisazo pigment represented by the formula (1) was added and dispersed by a ball mill for 72 hours, and then 210 parts by weight of cyclohexanone was added and dispersed for 3 hours to prepare a coating solution for a charge generation layer having an absorption peak at 900 nm or less. . A charge generation layer coating solution was applied onto the intermediate layer by dip coating, and dried at 130 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.

  Chemical structural formula

で示される電荷輸送物質７重量部、ポリカーボネート樹脂ユーピロンＺ２００（三菱ガス化学社製）１０重量部及びシリコーンオイルＫＦ−５０（信越化学工業社製）０．００２重量部をテトラヒドロフラン１００重量部に溶解させた電荷輸送層の塗液を作製した。浸漬塗工法により、電荷発生層上に電荷輸送層の塗液を塗布し、１３０℃で２０分間乾燥して、膜厚２２μｍの電荷輸送層を形成した。

7 parts by weight of the charge transporting material represented by the formula, 10 parts by weight of the polycarbonate resin Iupilon Z200 (manufactured by Mitsubishi Gas Chemical) and 0.002 parts by weight of silicone oil KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.) are dissolved in 100 parts by weight of tetrahydrofuran. A coating liquid for the charge transport layer was prepared. A charge transport layer coating solution was applied onto the charge generation layer by dip coating, and dried at 130 ° C. for 20 minutes to form a charge transport layer having a thickness of 22 μm.

It is the schematic which shows an example of a circulation type dip coating apparatus. It is a figure which shows an example of a film thickness measuring apparatus. It is sectional drawing which shows an example of the transmission optical system used for a film thickness measuring apparatus. FIG. 2 is a schematic diagram illustrating an example of a configuration of a photoconductor of the present invention. It is a figure which shows an example of the result measured using the film thickness measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Coating layer 12 Filter 13 Circulation pump 14 Stirring blade 15 Storage tank 16 Stirring motor 17 Conductive substrate 18 Elevator 20 Measured object 21 Light source 22 Fiber probe 22a Radiation light transmission fiber 22b Reflected light transmission fiber 23 Objective lens 24 Spectroscopy Means 25 Spectral intensity detection means 26 Arithmetic means 27 Lens tube 41 Conductive substrate 42 Undercoat layer 43 Intermediate layer 44 Photosensitive layer 44a Charge generation layer 44b Charge transport layer

Claims (6)

Using a dip coating method, applying a coating solution to a conductive substrate having a ten-point average roughness of 0.7 μm or more and 1.2 μm or less;
Incident light was incident on the wet film formed by applying the coating liquid perpendicularly to the film, and was reflected from the surface of the film and reflected from the surface of the conductive substrate. By spectroscopically analyzing the reflected light obtained by interference with light, detecting the light quantity of the split reflected light, and calculating the spectral spectrum intensity from the light quantity, by expanding the dynamic range of the spectral spectrum intensity Determining the wavelength at which the spectral spectrum intensity is minimum and maximum, and measuring the film thickness of the film using the wavelength at which the spectral spectrum intensity is minimum and maximum and the refractive index of the film,
A method for producing a photoreceptor, comprising producing a photoreceptor by controlling conditions for applying the coating liquid based on the measured film thickness.   2. The method for producing a photoreceptor according to claim 1, wherein an objective lens having a diameter of 6 mm to 30 mm is provided so that a distance from the surface of the film is 40 mm to 70 mm. The conductive substrate has a cylindrical shape or a belt shape,
3. The method of manufacturing a photoconductor according to claim 1, wherein the film thickness distribution of the film is obtained by measuring the film thickness of the film along the axial direction of the conductive substrate.   The method for manufacturing a photoreceptor according to claim 1, wherein the condition for applying the coating liquid is a coating speed of the coating liquid.   The method for producing a photoreceptor according to claim 1, wherein the condition for applying the coating liquid is a physical property of the coating liquid.   A photoconductor produced by the method for producing a photoconductor according to claim 1.

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