JP2007248444A - Film thickness measuring method and device of wet film, manufacturing method of photoconductive photoreceptor using method and device, and photoconductive photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely and precisely measure a light transmitting wet film formed on a surface of a coating object. <P>SOLUTION: A coated substance in which the wet film is formed on a surface of the coating object provided with at least a hardened layer formed on a support substrate is made as a body to be measured. Light from a light source is guided by an irradiation light guiding fiber of a fiber probe (FP) and emitted from an emission part thereof. The emitted luminous flux is perpendicularly incident on the object to be measured by an objective lens of a condensing optical system and condensed on the wet film. Interference reflected light reflected by the outermost surface of the wet film and the outermost surface of the hardened layer is returned to an end face of a detection light transmission fiber of the (FP) via the objective lens, and is guided to a spectroscopic means by the detection light transmission fiber so as to be separated. The film thickness of the wet film is arithmetically calculated on the basis of respective wavelengths providing the minimum and the maximum of the obtained spectroscopic spectral intensity and a refractive index of the wet film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a film thickness measuring method for measuring a film thickness of a wet film by applying a light interference method to a coated object in which a light transmissive wet film is formed on the surface of the coating object. The present invention relates to a film thickness measuring apparatus, a method for manufacturing a photoconductive photoreceptor using the film thickness measuring method and apparatus, and a photoconductive photoreceptor obtained by the manufacturing method.

  An image forming apparatus that forms an electrostatic latent image on a photoconductive photosensitive member, transfers a toner image obtained by developing the electrostatic latent image to a sheet-like recording medium, and fixes the image to form an image. It is known as a digital copying machine, facsimile, various optical printers, optical plotters, and the like.

  Some photoconductive photoreceptors can fix a toner image as it is, such as zinc oxide photosensitive paper, but the photoconductive photoreceptor used in an image forming apparatus that transfers a toner image onto a sheet-like recording medium. The body can be used repeatedly, and is generally formed into a drum shape or an endless / endless belt shape, and each step of image formation is performed while moving the peripheral surface in one direction.

In general, a photoconductive photoreceptor that can be used repeatedly has an intermediate layer as an undercoat layer formed on a conductive substrate, and a photoconductive photosensitive layer formed on the intermediate layer.
In an image forming apparatus using a photoconductive photoconductor that can be used repeatedly, various members such as a charging roller, a developing brush, a transfer roller, a cleaning brush, and a cleaning blade are physically provided on the surface of the photoconductive photoconductor. Due to this physical contact, the surface of the photosensitive layer gradually wears as the image forming process is repeated. In particular, the rubbing force by the cleaning brush and the cleaning blade is large, which is a significant factor in photosensitive layer wear.

  If the thickness of the photosensitive layer is reduced to a certain extent as the photosensitive layer is worn, the photosensitivity is remarkably reduced or the charging characteristics are deteriorated and the surface cannot be uniformly charged to a desired potential. An image cannot be formed. In this way, the life of the photoconductive photoreceptor is exhausted. For this reason, the film thickness of the photosensitive layer in the photoconductive photoreceptor is a very important factor in terms of characteristics.

  As a method for measuring the film thickness (layer thickness) of the photosensitive layer, conventionally, the charging current when charging the surface of the photosensitive layer by applying a constant voltage to the charging means is made to correspond to the layer thickness of the photosensitive layer. "Current detection method" that converts the change over time into the change in layer thickness of the photosensitive layer, or the amount of infrared absorption by the photosensitive layer from the intensity of the component that is irradiated with infrared rays and reflected by the intermediate layer An “infrared absorption method” for obtaining the layer thickness by measuring the thickness is being studied.

In the current detection method, the measured current value is easily affected by environmental changes such as temperature and humidity, and it is not always easy to obtain a highly reliable measurement result. Further, as described above, there are various contact members on the surface of the photosensitive layer, and a certain amount of current leakage inevitably occurs through the contact member when measuring the layer thickness of the photosensitive layer. It is difficult to measure at 5 μm or less.
On the other hand, since the infrared absorption method is an optical measurement, it has an advantage that the layer thickness can be measured without physical contact. However, the infrared absorption method cannot achieve the required measurement accuracy, or the measurement itself becomes impossible due to variations in the calibration curve acquired in advance, so the types of photosensitive layers that can measure the layer thickness are limited, and versatility. There is a problem from the aspect.

  Although it is conceivable to optically measure the film thickness of the “light-transmitting film” by applying the conventionally known “light interference film thickness measurement method”, a conventionally known apparatus or measurement is possible. In this method, only a transparent layer formed on a conductive substrate having a mirror surface can be measured. For example, the effect of scattering by filler fine particles or pigment particles dispersed in a photosensitive layer, or light diffusion in an intermediate layer, a conductive substrate ( For example, scattering caused by the surface roughness of a cut metal substrate) can cause a so-called “detection light sufficiently separated from the maximum and minimum of spectral spectrum intensity” necessary for film thickness measurement.

In order to deal with the above problem, the present applicant has previously described a light-transmitting film thickness measuring method and film thickness measuring apparatus using optical interference, an image forming apparatus having a film thickness measuring apparatus, a photoconductive photoreceptor, and light. A method for producing a conductive photoreceptor has been proposed (see, for example, Patent Document 1 below).
With this proposal, the light-transmitting film thickness (for example, photosensitive layer) formed on the support substrate via the undercoat layer or the sum of the undercoat layer and the light-transmitting film thickness can be measured reliably and accurately. can do. In Patent Document 1 below, there is no description regarding a film thickness measurement method for a wet film formed through a cured layer on a support substrate.

  Several methods for measuring the thickness of the optical interference film thickness have been proposed (for example, refer to Patent Documents 2 to 6 below), but the film thickness measurement of the wet film targeted by the present invention is performed reliably and accurately. It was not enough as a method to do.

JP 2003-287409 A JP-A-6-77302 JP-A-11-201730 JP 2000-186916 A JP 2000-356859 A Japanese Patent Laid-Open No. 2001-27815

  The present invention has been made in view of the above-described circumstances, and a coating liquid containing a polymerizable resin and a solvent on the surface of a coating object in which a cured layer containing a cured resin is provided on a support substrate in advance. A coating material having a light-transmitting wet film formed by the above method is used as a measurement object, and a film thickness measurement method for reliably and accurately measuring the film thickness of the wet film in the measurement object is provided. It is an object of the present invention to provide a film thickness measuring device for carrying out a film thickness measuring method for a wet film, a method for producing a photoconductive photoreceptor to which the film thickness measuring method is applied, and a photoconductive photoreceptor.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by the inventions described in the following (1) to (23), and have reached the present invention. This will be specifically described below.

  According to the first aspect of the present invention, a light-transmitting wet film is formed on a surface of a coating object on which a cured layer containing at least a cured resin is previously provided on a support substrate by a coating liquid containing a polymerizable resin and a solvent. A method for measuring a film thickness of a wet film on the object to be measured, wherein the formed coating material is the object to be measured, wherein the film thickness of the wet film is a light from a light source that emits spectrum light in a desired wavelength region. The light is guided by an irradiation light guiding fiber disposed on the fiber probe and emitted from the emission part, and this radiated light beam is vertically incident on the object to be measured by the objective lens of the condensing optical system and is condensed on the wet film. The reflected light reflected and interfered with each other at the outermost surface of the wet film and the outermost surface of the hardened layer is returned to the end surface of the detection light transmission fiber disposed in the fiber probe via the objective lens, and the detected light Separation by transmission fiber Film thickness measurement of a wet film characterized in that the wet film thickness is calculated and calculated based on each wavelength giving the minimum and maximum of the spectral spectrum intensity obtained and spectrally guided to the means, and the refractive index of the wet film Is the method.

  The wet film thickness measuring method can reliably and accurately measure the wet film thickness on the object to be measured, and thus can be widely applied to various coated products. In particular, a precursor in which a coated product in which a cured layer such as an intermediate layer or a photosensitive layer is previously formed on a conductive substrate is provided with a wet film, that is, an electrophotographic photosensitive member ( Hereinafter, it may be referred to as “electrophotographic photoreceptor precursor”).

The invention according to claim 2 is the wet film thickness measuring method according to claim 1, wherein the spectral wavelength range of the spectroscopic means is 770 to 1050 nm.
By setting the spectral wavelength range to 770 to 1050 nm, it is possible to secure a measurement wavelength in a region suitable for wet film thickness measurement even if there are scattering elements with a film surface property or a size smaller than the wavelength present in the film. it can. Further, as shown in FIG. 7, since the change in light dispersion (refractive index) becomes a broad region, it is possible to stably measure the wet film thickness.

According to a third aspect of the present invention, there is provided the calibration method according to the first or second aspect, wherein the calculation means has a calibration method for expanding the spectral spectrum intensity (reflectance) obtained by the spectroscopy to an arbitrary size. This is a film thickness measurement method.
By expanding the spectral spectrum intensity to an arbitrary size, the visibility of the interference waveform is improved, and it becomes easy to extract the wavelength indicating the minimum and maximum, so that it is possible to measure the wet film thickness with high accuracy. .

The invention according to claim 4 is a calibration method for calculation calculation, wherein the obtained spectral spectrum intensity to be oscillated is calibrated to a small size by using a standard sample with a known reflectivity and enlarged to an arbitrary size. The wet film thickness measuring method according to claim 3.
Using a standard sample, the amount of reflected light is reduced and calibrated, and the spectral spectrum intensity is expanded to an arbitrary size, thereby improving the visibility of the interference waveform and facilitating extraction of wavelengths that exhibit the minimum and maximum. Therefore, it becomes possible to measure the wet film thickness with high accuracy.

According to a fifth aspect of the present invention, in the coating object, the support substrate is a conductive substrate, the cured layer containing a cured resin is an intermediate layer in which fine particles are dispersed and contained in a binder resin, and the intermediate layer 5. The wet film thickness measuring method according to claim 1, wherein the wet film thickness measuring method comprises a layer structure in which a photosensitive hardened layer containing a photoconductive substance and a binder resin is sequentially provided. is there.
By the wet film thickness measurement method provided on the surface of the coating object having the above layer structure, the wet film thickness of the precursor when the electrophotographic photosensitive member is produced is reliably and accurately measured.
Note that the photosensitive hardened layer has a functional separation between the charge generation layer containing the charge generation material and the charge transport layer containing the charge transport material, even if the photoconductive material contains a charge generation material and a charge transport material at the same time. A laminated structure may be used.

  According to a sixth aspect of the present invention, the photosensitive hardened layer has a laminated structure in which a charge transport layer containing a charge transport material and a binder resin is sequentially provided on a charge generation layer containing a charge generation material and a binder resin. The film thickness measuring method for a wet film according to any one of claims 1 to 5.

  Precursor for producing an electrophotographic photoreceptor in which the charge generation and charge transport functions in the photosensitive cured layer are separated by the method for measuring the thickness of the wet film provided on the surface of the coating object having the above-described laminated structure The film thickness of the wet film is measured reliably and accurately.

  According to a seventh aspect of the invention, the light-transmitting wet film has a charge transporting molecular structure and is formed of a coating liquid containing a photocrosslinking polymerizable resin that is polymerized and cured by application of light energy and a solvent. The wet film thickness measuring method according to claim 1, wherein the wet film thickness is a coated film.

  By using a wet film containing a photocrosslinkable polymerizable resin (hereinafter sometimes referred to as “photocrosslinkable resin”), in the curing process of the wet film reliably and accurately measured, A cured film (surface layer) can be formed easily and quickly by application.

  Invention of Claim 8 is a film thickness measuring apparatus which implements the film thickness measuring method of the wet film | membrane in the to-be-measured object as described in any one of Claims 1 thru | or 7, Comprising: The said apparatus is a desired wavelength area | region. A light source that emits spectrum light, and the light from the light source is guided to the measured object side by the irradiation light guiding fiber, and emitted from the emission part toward the measured object side, and the reflected light from the measured object is detected. A fiber probe that receives and transmits light through an optical transmission fiber, and a condensing optical system that irradiates the irradiated light emitted from the emission part of the fiber probe perpendicularly to the surface of the object to be measured and condenses it toward the light-transmitting wet film. The reflected light that is reflected by the objective lens of the system and the wet film outermost surface and the hardened layer outermost surface of the object to be measured and interferes with each other is transmitted by the detection light transmission fiber through the objective lens of the focusing optical system. Transmitted detection A spectral means for separating the spectral light, a spectral intensity detecting means for detecting the spectral spectral intensity of the detection light split by the spectral means, and an arithmetic means for calculating a reflectance from the spectral spectral intensity. When calculating the reflectance curve using the reflected light obtained by the spectral intensity detection means, the reflectance curve is calibrated using a standard sample with a known reflectance and the actual amount of reflected light is reduced. Then, a reflectance curve having a minimum and a maximum is obtained from the spectral spectrum intensity, and the wavelength at which the reflectance curve is minimum and maximum and the refractive index of the light-transmitting wet film are used to determine the light transmittance of the object to be measured. A film thickness measuring apparatus comprising: a calculation means for calculating and calculating a film thickness of the wet film.

  With the film thickness measuring apparatus having the above-described configuration, the film thickness of the light-transmitting wet film can be easily, reliably and accurately measured without being affected by changes in the environment such as temperature and humidity.

  A ninth aspect of the present invention is the film thickness measuring apparatus according to the eighth aspect, wherein the condensing optical system has a numerical aperture (NA) of 0.3 or less.

  If the numerical aperture (NA) of the condensing optical system is 0.3 or less, it is possible to detect the spectral spectrum intensity of the detection light favorably.

  The invention according to claim 10 is the film thickness measuring device according to claim 8 or 9, wherein the objective lens is an achromatic lens.

  When the objective lens is an achromatic lens, it is possible to remove chromatic aberration at the time of light collection and light reception, and it is possible to detect a spectral spectrum intensity with high light collection and good wavelength accuracy.

  An eleventh aspect of the present invention is the film thickness measuring apparatus according to any one of the eighth to tenth aspects, wherein the light source is a halogen-tungsten lamp.

  Since the light emitted from the halogen-tungsten lamp has a spectral distribution in a wide wavelength region, the “spectral light in the desired wavelength region” can be easily realized.

  A twelfth aspect of the present invention is the film thickness measuring apparatus according to any one of the eighth to eleventh aspects, wherein the spectroscopic means is a diffraction grating, a prism, or a spectral filter.

As the spectroscopic means in the film thickness measuring apparatus of the present invention, any of a diffraction grating, a prism and a spectral filter can be used, and the film thickness can be measured reliably and with high accuracy.
If fixed spectroscopic means (for example, a diffraction grating used in a spatially fixed manner) is used, a space for rotating and a rotating mechanism become unnecessary, and thus the film thickness measuring apparatus can be made compact. Become.

  A thirteenth aspect of the present invention is the film thickness measuring apparatus according to any one of the eighth to twelfth aspects, wherein the spectrum intensity detecting means is a line sensor or a silicon photodiode array.

  As the spectral intensity detection means in the film thickness measuring apparatus of the present invention, a line sensor or a silicon photodiode array can be preferably used, and the film thickness can be measured reliably and with high accuracy. In particular, silicon photodiodes have the advantage of being small, light and inexpensive.

  According to a fourteenth aspect of the present invention, the end of the fiber probe facing the objective lens is centered on the reflected light receiving end surface of the detection light transmitting fiber, and the exit end surface of the irradiation light guiding fiber surrounds the end portion. The film thickness measuring apparatus according to claim 8, wherein the film thickness measuring apparatus is configured as follows.

  With the above configuration, the irradiation light from the objective lens side is condensed on the object to be measured as a circular light source, and interference reflected light (detection light having a good spectral intensity) is obtained, and the spectral spectral intensity is minimized and maximized. Each wavelength is acquired.

  According to a fifteenth aspect of the present invention, the calculation means stores one or more types of spectral refractive index data relating to a light-transmitting wet film that can be a measurement target, in a usable manner. It is a film thickness measuring apparatus as described in any one.

  Referring to the corresponding spectral refractive index data regarding the light-transmitting wet film, estimate the dry cured film thickness corresponding to the measured wet film thickness, and continue the subsequent wet film coating process to obtain the desired film thickness. Since it can control so that it may be obtained, a high quality product with a uniform film thickness is obtained.

  The invention according to claim 16 has a filter for cutting light in an unnecessary wavelength region out of light emitted from the light source, and the film thickness measuring device according to any one of claims 8 to 15 It is.

  By cutting the light in the wavelength region that does not contribute to the film thickness measurement, the measured object (particularly, the coated material having a structure that is a precursor of the photoconductive photosensitive member) is not damaged such as light fatigue. The film thickness can be measured reliably and with high accuracy.

  According to a seventeenth aspect of the present invention, there is provided an intermediate layer forming step in which a coating liquid containing a binder resin and fine particles is applied on a support substrate made of a conductive substrate, and dried and cured to form an intermediate layer. A coating solution containing a conductive material and a binder resin is applied, dried and cured to form a photosensitive cured layer, and a surface of a coating object formed of the intermediate layer and the photosensitive cured layer. A spray coating process in which a coating liquid containing a photo-crosslinking type polymerizable resin that has charge transportability and is polymerized and cured by application of light energy and a solvent is applied by a spray coating method to form a light-transmitting wet film; The coating material on which the light-transmitting wet film is formed is a measurement object, and the wet film thickness measurement method according to any one of claims 1 to 7 is applied to the wet film thickness. The film thickness measurement process to be measured and the wet film after the film thickness measurement process It is provided with a wet film curing step for applying energy to cure and further drying to form a surface layer, and spray coating while controlling the spray coating conditions based on the thickness of the wet film measured in the film thickness measurement step. It is a manufacturing method of a photoconductive photoconductor characterized by performing a process.

  According to the above manufacturing method, a photoconductive photoconductor having a uniform film thickness can be easily and reliably manufactured. The photoconductive photoconductor manufactured in this way has a uniform quality and high reliability.

  According to an eighteenth aspect of the present invention, in the photosensitive cured layer forming step, a charge generating layer forming step in which a coating liquid containing a charge generating substance and a binder resin is applied and dried and cured to form a charge generating layer; 18. A photoconductive feeling according to claim 17, further comprising a charge transport layer forming step of applying a coating liquid containing a charge transport material and a binder resin on the layer and drying and curing to form a charge transport layer. It is a manufacturing method of a light body.

  According to the above process, an electrophotographic photosensitive member in which the functions of charge generation and charge transport are separated can be easily and reliably manufactured. The photoconductive photosensitive member manufactured in this way has a uniform quality and high reliability.

  According to a nineteenth aspect of the present invention, the conductive substrate is cylindrical or belt-shaped, and the wet film thickness in the film thickness measurement step is measured in the direction of the rotation axis of the cylindrical or belt-shaped conductive substrate. The photoconductive photoreceptor according to claim 17, wherein the spray coating process is performed while controlling the spray coating conditions based on the film thickness distribution. It is a manufacturing method.

  As described above, light having a uniform film thickness composed of a cylindrical or belt-like conductive substrate used in an electrophotographic image forming apparatus (for example, an analog or digital copying apparatus, facsimile, various optical printers, optical plotters, etc.). A conductive photoconductor can be manufactured easily and reliably, and the photoconductive photoconductor manufactured in this way has a uniform quality and high reliability.

  The invention according to claim 20 is characterized in that, based on the film thickness of the wet film measured in the film thickness measurement process, the coating amount is adjusted by controlling the discharge amount of the coating liquid in the spray coating process. Item 20. The method for producing a photoconductive photoconductor according to any one of Items 17 to 19.

  By controlling the discharge amount of the coating liquid, the film thickness of the wet film can be made uniform with certainty and high accuracy. This produces a high-quality and highly reliable photoconductive photoreceptor.

  The invention of claim 21 is characterized in that the wet film applied to the surface of the object to be coated comprising the intermediate layer and the photosensitive cured layer is cured by applying light energy to the wet film to form a surface layer. The distance between the outermost surface of the layer and the outermost surface of the photosensitive cured layer is determined by guiding light from a light source that emits spectrum light in a desired wavelength region by an irradiation light guide fiber disposed in the fiber probe and emitting the light. The radiated light flux is vertically incident on the object to be measured by the objective lens of the condensing optical system and is condensed on the wet film, and is reflected by the outermost surface layer and the outermost surface of the photosensitive cured layer, respectively. The reflected light that has interfered is returned to the end face of the detection light transmission fiber disposed in the fiber probe via the objective lens, guided to the spectroscopic means by the detection light transmission fiber, and spectrally dispersed. Giving the minimum and maximum 21. The method for producing a photoconductive photoreceptor according to claim 17, further comprising a step of calculating and measuring based on each wavelength and the refractive index of the surface layer. is there.

  Since the thickness of the surface layer is controlled by measuring the thickness of the surface layer by an optical interference method, a photoconductive photoconductor having uniform quality and high reliability can be obtained.

  According to a twenty-second aspect of the present invention, there is provided a film thickness measuring apparatus for performing a method for measuring a film thickness of a wet film on the object to be measured. A fiber probe that guides light to the measured object side through a fiber, radiates it from the emitting part toward the measured object side, and receives and transmits reflected light from the measured object by a detection light transmission fiber; and The objective lens of the condensing optical system that vertically irradiates the irradiated light emitted from the emitting part to the surface of the object to be measured and condenses it toward the light-transmitting wet film, and the wet film outermost surface of the object to be measured and the hardened layer outermost Reflected lights that are reflected from the surface and interfere with each other are transmitted by a detection light transmission fiber through the objective lens of the condensing optical system, and the transmitted detection light is dispersed. Based on the spectral intensity detection means for detecting the spectral intensity of the detected light, the wavelengths giving the minimum and maximum of the obtained spectral spectrum intensity, and the refractive index of the light-transmitting wet film. The method for producing a photoconductive photoconductor according to any one of claims 17 to 21, further comprising a calculation unit that calculates and calculates a film thickness of the permeable wet film.

  With the film thickness measuring device, a photoconductive photoreceptor having a uniform film thickness can be easily and reliably manufactured without being affected by changes in the environment such as temperature and humidity. The manufactured photoconductive photoreceptor has a uniform quality and high reliability.

  A twenty-third aspect of the present invention is a photoconductive photoconductor produced by the method for producing a photoconductive photoconductor according to any one of the seventeenth to twenty-second aspects.

  The above-mentioned electrophotographic photosensitive member has a uniform and stable surface layer thickness and high reliability, so it has excellent wear resistance, and there is little loss of photosensitivity and deterioration of charging characteristics even in long-term use, and a clear image is always obtained. Can be formed.

According to the method for measuring the thickness of a wet film according to the present invention, a coated object (object to be measured) in which a light-transmissive wet film is formed on the surface of a coating object on which a cured layer is previously provided on a support substrate. The wet film thickness can be measured reliably and accurately.
According to the film thickness measuring apparatus of the present invention, the wet film thickness measuring method can be easily and reliably performed with high accuracy without being affected by environmental changes.
According to the method for producing a photoconductive photoreceptor according to the present invention, a reliable and high-quality photoconductive photoreceptor having a uniform film thickness can be easily and reliably produced.
According to the photoconductive photoreceptor of the present invention, the surface layer film thickness is uniform and stable, and thus has excellent wear resistance. For example, even if it is used for a long time in image formation by electrophotography, photosensitivity and charging characteristics are obtained. Is maintained well and a clear image can always be formed.

  As described above, the method for measuring the thickness of a wet film according to the present invention includes a coating containing a polymerizable resin and a solvent on the surface of a coating object on which a cured layer containing at least a cured resin is previously provided on a support substrate. A method for measuring a film thickness of a wet film in the measurement object, wherein a coating object in which a light-transmitting wet film is formed by a working liquid is used, wherein the film thickness of the wet film is set in a desired wavelength region. Light from a light source that emits spectrum light is guided by an irradiation light guiding fiber disposed in a fiber probe and radiated from its emission part, and this radiated light flux is directed to a measurement object by an objective lens of a condensing optical system. Detected light is transmitted to the fiber probe through the objective lens, and the reflected light that is vertically incident and condensed on the wet film and reflected on the wet film outermost surface and the hardened layer outermost surface is interfered with each other. Return to the end of the fiber It is characterized in that the wet film thickness is calculated and calculated based on each wavelength that gives the minimum and maximum of the spectral spectrum intensity obtained and the refractive index of the wet film, and the light is guided to the spectroscopic means by the detection light transmission fiber. To do.

FIG. 1 shows a schematic configuration cross-sectional view of an object to be measured which is a coated product in the wet film thickness measuring method.
In the coated object (object to be measured) 10 shown in FIG. 1, a light-transmitting wet film 5 is formed on the surface of a coated object 4 in which a cured layer 3 containing a cured resin is provided on a support substrate 2 in advance. Has been.

The configuration of FIG. 1 is a precursor in the case of manufacturing a photoconductive photoreceptor used for an image forming apparatus (analog or digital copying apparatus, facsimile, various optical printers, optical plotters, etc.) that forms an image by electrophotography. It can be applied to the structure of the body.
That is, as shown in the schematic cross-sectional view of FIG. 2, the support substrate of the coating object 4 of FIG. 1 is the conductive substrate 2a, and the cured layer 3 containing the cured resin of FIG. The intermediate layer 3a containing fine particles in a dispersed manner can be formed, and a photosensitive hardened layer 3b containing a photoconductive substance and a binder resin can be sequentially provided on the intermediate layer 3a.

Further, as shown in the schematic cross-sectional view of FIG. 3, the photosensitive cured layer 3b of FIG. 2 includes a charge generation layer 3b ₁ containing a charge generation material and a binder resin, and a charge transport containing a charge transport material and a binder resin. A stacked structure in which the layer 3b ₂ is sequentially provided can be employed.
A detailed description of each constituent layer of the photoreceptor will be described later.

In addition, as a preferable example of the light-transmitting wet film 5 of FIGS. 1 to 3, a photocrosslinking type polymerizable resin (photocrosslinking type resin: which has a charge transporting molecular structure and is polymerized and cured by application of light energy: For example, the coating film formed using the coating liquid containing UV curable resin) and a solvent is mentioned.
Detailed description regarding the photocrosslinking resin will be described later.
In addition, the coating material as the said to-be-measured body 10 is a precursor of a photoconductive photoreceptor as mentioned above. That is, the photoconductive photoreceptor is obtained by curing the wet film 5 of the coated product to form a surface layer.

FIG. 4 is a coating film formed by using the light-transmitting wet film 5 shown in FIG. 3 by using a coating liquid containing a photocrosslinking resin and a solvent, which is cured by applying light energy to the surface layer. A schematic cross-sectional view of the photoconductive photoconductor 20 designated as 5a is shown. In FIG. 4, the charge generation layer 3 b ₁ , the charge transport layer 3 b _2, and the surface layer 5 a form the photosensitive layer 6.

Next, an apparatus for performing the film thickness measurement method of the wet film 5 and a film thickness measurement method will be described.
[Apparatus for executing film thickness measurement method]
The apparatus for executing the film thickness measurement method of the present invention includes at least a “light source”, a “fiber probe”, a “spectrometer”, a “spectral intensity detector”, and a “calculator”.
FIG. 5 is a schematic diagram showing a configuration example (a) of an apparatus for executing the film thickness measurement method of the present invention and an objective lens side end (b) of the fiber probe.
A film thickness measuring device 9 shown in FIG. 5 includes a light source 91 that emits spectrum light in a desired wavelength region, and a light to be measured 10 (for example, a coating shown in FIG. A fiber probe 93 for guiding the light to the object) side, radiating it from the emitting part toward the measured object side, and receiving and transmitting the reflected light from the measured object 10 by the detection light transmission fiber 92; The objective lens 94 of the condensing optical system for converging the irradiated light emitted from the emitting part vertically onto the surface of the measured object 10 and condensing it toward the light-transmitting wet film, and the outermost surface of the wet film of the measured object 10 and curing. Reflected light beams reflected and interfered with each other on the outermost surface of the layer (for example, the surface of the charge transport layer 3b2 in FIG. 3) are transmitted by the detection light transmission fiber via the objective lens 94 of the condensing optical system. Detection light , A spectral intensity detecting means 97 for detecting the spectral intensity of the detection light split by the spectroscopic means 96, each wavelength giving the minimum and maximum of the obtained spectral spectral intensity, and light transmission And a calculating means 98 for calculating and calculating the film thickness of the light-transmitting wet film in the measured object 10 based on the refractive index of the wet film.

  As described above, the above-mentioned problems in the conventional current detection method, infrared absorption method meter, optical interference film thickness measurement method, etc. (for example, influence due to environmental changes such as temperature and humidity, scattering due to substrate surface roughness or scattering due to constituent layers, The effect of light diffusion and the like is solved, and a light-transmitting wet film / film thickness can be measured easily, reliably and with high accuracy.

  As the light source 91 in the film thickness measuring device 9, a halogen-tungsten lamp having a spectral spectrum distribution in a wide wavelength region from the visible region to the near-infrared region is preferably used, and radiation of the “spectral light in the desired wavelength region” is facilitated. Can be realized. In addition, an LED having a light emission distribution at 400 to 1000 nm can be used as the light source.

In addition to the above-described film thickness measurement device configuration, a filter that cuts light in an unnecessary wavelength region out of light emitted from a light source that emits spectrum light in a desired wavelength region can be provided.
That is, the “unnecessary wavelength region” light is light in a wavelength region that does not contribute to film thickness measurement, and is irradiated with light in this wavelength region, for example, photoconductive as shown in FIGS. This is light that causes damage such as light fatigue when it is a precursor of a photosensitive photoreceptor. The light in the unnecessary wavelength region is determined by the spectral characteristics of the object to be measured (for example, the spectral sensitivity and spectral absorption characteristics of the photoconductive photoconductor).

When the object to be measured is a precursor of a photoconductive photoreceptor, the setting region of the unnecessary wavelength region is preferably a non-absorption band of the photosensitive layer, and particularly preferably a near infrared region. As a filter in this case, a sharp cut filter or the like that transmits light in a wavelength region of 770 to 1050 nm is suitable.
A film thickness measuring device having a filter that cuts light in the unnecessary wavelength region will be described later.

The condensing optical system provided with the objective lens 94 preferably has a numerical aperture (NA) of 0.3 or less. By using a condensing optical system having an NA of 0.3 or less, it is possible to detect the spectral spectrum intensity of the detection light with good accuracy.
The objective lens 94 of the focusing optical system is fixed to one end portion of the lens barrel 95, and the other end portion of the lens barrel 95 holds the emission side end portion of the fiber probe 93.
The objective lens 94 is preferably an “achromatic lens”. By using the objective lens 94 as an achromatic lens, it is possible to remove chromatic aberration at the time of light collection and light reception, and to detect a spectral spectrum intensity with high light condensing property and good wavelength accuracy.

  In the example in the description, for example, an achromatic lens having a lens diameter of 25.4 mm and a focal length of 30 mm is used. Further, the distance between the objective lens 94 and the surface of the measured object 10 (for example, the coated material shown in FIG. 3) is 70 mm, and the distance between the objective lens 94 and the emission side end of the fiber probe 93 is 52.5 mm. . From NA = n sin u (u: 1/2 of the angle extending from the on-axis object point to the objective lens), the NA is about 0.17.

As shown in FIG. 5B, the end of the fiber probe 93 facing the objective lens 94 side is centered on the reflected light receiving end surface of the detection light transmitting fiber 92, and this is emitted from the irradiation light guiding fiber 930. It is comprised so that a part end surface may surround.
That is, the light radiated from the emitting portion of the irradiation light guide fiber is collected by the objective lens 94 as a light spot having a diameter of 0.53 mm on the surface of the measurement object 10. That is, the diameter of the end face of the irradiation light guiding fiber 930 is 0.2 mm, and when the bundle of fibers shown in FIG. 5B is a circular light source having a diameter of 0.4 mm, the imaging magnification (= 70 / 52.5 = 1.33), the diameter of the light spot is 0.53 mm.

As the spectroscopic means 96, a diffraction grating, a prism, or a spectroscopic filter can be used.
As the spectroscopic means such as a diffraction grating, a rotation type that changes the spectral wavelength region by rotation can be used. However, if a fixed spectroscopic means such as a diffraction grating that is spatially fixed is used, rotation is possible. Therefore, the film thickness measuring apparatus can be made compact.

  The example spectroscopic means 96 is a diffraction grating, specifically, a fixed Zernitana diffraction grating. This diffraction grating has a spectral region of 770 to 1050 nm and a resolution of 0.5 nm / point. As the spectroscopic means 96, as described above, a prism or a spectroscopic filter may be used instead of the diffraction grating.

As the spectral intensity detection means 97, a line sensor such as a CCD or a silicon photodiode array in which silicon photodiodes are arranged at predetermined spectral wavelength positions can be suitably used.
The illustrated spectral intensity detection means 97 is a line sensor, and has a sensitivity in the range from the visible range to 1050 nm and uses 512 light receiving elements. It goes without saying that the above-described silicon photodiode array can be used in place of such a line sensor. Silicon photodiodes are small, light, and inexpensive.

The calculation means 98 calculates the data detected by the spectrum intensity detection means 97 as a continuous spectral spectrum intensity, and performs a differential operation on the obtained spectral spectrum intensity to determine each specified wavelength that gives a minimum / maximum. The calculation is performed based on the refractive index of the wet film of the measured object 10. A specific method of calculation calculation will be described later.
The calculation means 98 can store one or more types of spectral refractive index data relating to a light-transmitting wet film that can be a measurement target.

[Thickness measurement method]
Next, a method for measuring the film thickness of the wet film in the object to be measured 10, that is, the principle will be described by taking as an example a configuration that is a precursor of the photoconductive photoreceptor shown in FIG.
That is, the measured object 10 in this case is provided with an intermediate layer 3a containing fine particles dispersed in a binder resin as a hardened layer on the conductive substrate 2a, and the charge generating substance and the binder resin are contained on the intermediate layer 3a. On the surface of a coating object provided with a photosensitive cured layer having a laminated structure in which a charge generating layer 3b ₁ to be formed, a charge transporting material and a charge transport layer 3b ₂ containing a binder resin are sequentially formed. This is a coated product provided with a wet film 5. Here, the wet film 5 is a coating film formed using a coating liquid containing a photocrosslinking resin and a solvent. Therefore, if the wet film 5 is applied with light energy and cured, and further dried to form a surface layer (surface layer 5a in FIG. 4), it can be used as a photoconductive photoreceptor.

  A part of the light collected by the objective lens 94 of the condensing optical system is reflected by the surface of the wet film 5, and part of the light is incident on the wet film 5 and is reflected by the surface of the charge transport layer 3 b 2. . The reflected light is condensed on the end face of the detection light transmission fiber 92 disposed on the fiber probe 93 via the objective lens 94 and transmitted to the spectroscopic means 96 through the fiber 92 as detection light. The transmitted detection light is split by the spectroscopic means 96, and the spectral intensity is detected by the spectral intensity detecting means 97.

FIG. 6 shows an example of the measurement result of the wet film measured using the film thickness measuring apparatus of the present invention. Here, the reflection curve 61 after normalization of the spectral distribution (spectrum) of the light source, the spectral characteristic (sensitivity characteristic) of the light receiving element, and the reflection characteristic of the standard sample are calculated from the amount of reflected light detected by the spectral intensity detecting means 97 and the calculation. Depending on the means 98, a theoretical reflectance curve 62 calculated from the reflectance curve 61 is shown.
The theoretical reflectance curve 62 indicates a theoretical reflectance curve calculated as a continuous reflectance curve from the optical model by a nonlinear least square method (for example, a curve fitting algorithm based on a nonlinear least square standard such as the simplex method). .
As shown in FIG. 6, the spectral spectrum intensity is finite over a wavelength range of 770 nm to 1000 nm, and the intensity changes in a vibrational manner with the wavelength in the entire wavelength area.

Here, in the wavelength region where the wavelength is larger than 770 nm, an appropriate change in the spectral spectrum intensity, that is, an adjacent maximum and minimum appropriate spectral spectrum intensity is selected. Then, thickness of the wet film: and d, the refractive index of the wet film: and n _1, the interference of order: m and as well known between, holds the relationship of the following equation. The wavelengths that give the maximum and minimum are λ _2m and λ _{2m + 1} . m can be appropriately determined.
2m = 4n ₁ d / λ _2m
2m + 1 = 4n ₁ d / λ _{2m + 1}
Erasing the interference order m from the above equations,
n ₁ d = λ _2m · λ _2m +1/4 (λ _2m -λ _{2m + 1} )
Is obtained.

Accordingly, if the wavelengths λ _2m and λ _{2m + 1} that give the maximum / minimum are known, the optical thickness n ₁ d of the wet film is known, and if the refractive index n ₁ is known, the thickness of the wet film to be obtained is known. The _length d can be calculated as d = λ _2m · λ _{2m + 1} / 4n ₁ (λ _2m −λ _{2m + 1} ) (1).

The refractive index of the wet film: n ₁ is uniquely determined when the material of the wet film 5 is determined, and the spectral characteristics, that is, the change in the refractive index of the wet state depending on the wavelength (spectral refractive index) is spectrally analyzed in advance. Measured with an ellipsometer and stored in the control means 98 as a table or “function of wavelength”, and in this way, each wavelength giving the minimum and maximum in spectral spectrum intensity: λ _{2m + 1} , λ _2m , refractive index of the wet film 5: n ₁ and the basis light permeability of the wet film thickness: the d, can be computed calculated in accordance with the equation (1).

  As is apparent from the above formula (1), when calculating the film thickness of the light-transmitting wet film, the absolute value of the reflectance is not necessary, and if the wavelength that gives the maximum and minimum values can be obtained with high accuracy, the wet film The film thickness d of the wet film can be measured using the spectral refractive index. In order to increase the accuracy of the wavelength that gives the maximum and minimum reflectance, the reflectance is increased to an arbitrary size.

Generally, what is directly measured by a spectrophotometer, spectral reflectance meter, optical interference film thickness meter, etc. is the amount of reflected light (or spectral spectrum intensity) from the sample, and the reflectance is known to obtain the reflectance. It is necessary to measure and calibrate the standard sample in advance. Thereby, the reflectance (curve) R (λ) of the sample is expressed by the following equation (2).
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 digital data received by the reflected light from the sample and handled in the calculation means, and I _d (λ) is a dark current component of the light receiver handled in the calculation means. Digital data, I _r (λ) is digital data in which the amount of reflected light from the standard sample is handled in the light receiving calculation means, and r (λ) represents the theoretical reflectance of the standard sample.

In the present invention, it is preferable to expand R (λ) to an arbitrary size by intentionally reducing the amount of reflected light of the standard sample serving as the denominator of equation (2). Specifically, for a standard sample having I _r1 (λ) and r ₁ (λ), a standard sample having I _r2 (λ) smaller than I _r1 (λ) is prepared, and I _r2 (λ) and R (λ) is calculated using r ₁ (λ).

That is, the computing unit 98 expands the reflectance to an arbitrary size when computing the reflectance from the amount of reflected light (or spectral spectrum intensity) detected by the spectrum intensity detecting unit 97. Further, after deriving a theoretical reflectance curve from the optical model for the obtained reflectance, the wavelengths λ _{2m + 1} and λ that give a minimum and a maximum by a differential operation etc. with respect to this theoretical reflectance curve _{2 m} is obtained, and based on the refractive index n ₁ of the wet film 5, the film thickness d of the light transmissive wet film is calculated according to the equation (1).

  In the experiment under the above conditions, the thickness of the wet surface layer could be accurately measured with a resolution of 0.1 μm or less.

  As described above, calculation of the film thickness of the wet film requires the spectral refractive index data of the wet film. In the above example, the spectral refractive index of the wet film in a so-called wet state can be used for the control means 98. Is remembered.

Various photoconductive photoreceptors are used for each type of image forming apparatus, and the material of the surface layer of these photoreceptors varies widely.
In the case of the film thickness measuring apparatus 9 shown in FIG. 5, the calculation means 98 stores “spectral refractive index data relating to the material (wet state) forming the wet film to be measured for the film thickness” in an available manner. However, in order to increase the versatility of the film thickness measurement device and adapt it to multiple types of photoconductors, the calculation means will display “a material that forms a wet film that can be measured for film thickness (wet condition). It is preferable to store one or more types of spectral refractive index data relating to).
FIG. 7 shows a specific example of one or more types of spectral refractive index data relating to a material for forming a wet film that can be a measurement target of the film thickness stored in the calculation means.

As described above, in the calculation calculation of the film thickness, the spectral refractive index: n ₁ is considered to be constant in the wavelength range of λ _{2m to} λ _{2m + 1} .
Therefore, the film thickness of the wet film is guided using the film thickness measuring device 9 to guide the light from the light source 91 that emits spectral light in the desired wavelength region by the irradiation light guiding fiber 930 disposed in the fiber probe 93. Then, the radiated light beam is radiated from the exit portion, and the radiated light beam is vertically incident on the measured object 10 by the objective lens 94 of the condensing optical system to be condensed on the wet film, and the wet film outermost surface and the hardened layer outermost surface The reflected lights that have been reflected and interfered with each other in the step are returned to the end face of the detection light transmission fiber 92 disposed on the fiber probe 93 via the objective lens 94 and guided to the spectroscopic means 96 by the detection light transmission fiber. It is carried out by a film thickness measurement method that performs calculation and calculation based on each wavelength: λ _2m , λ _{2m + 1} and the refractive index of the wet film: n ₁ that performs spectroscopy and gives the obtained spectral spectrum intensity minimum and maximum become.

  As a supplementary explanation, in the above embodiment, as a diffraction grating which is a spectroscopic means, a fixed Zellnitana diffraction grating (spectral region: 770 to 1050 nm, resolution: 0.5 nm / point) is prepared for measurement. However, the wavelength resolution of the diffraction grating is preferably in the range of 0.7 nm / point to 0.1 nm / point.

  As a detector capable of increasing the wavelength resolution, there is a CCD having a higher sensitivity than a photodiode and a maximum number of elements of 5000 pixels. However, there is a problem that noise is superimposed around 900 nm.

Increasing the wavelength resolution of the diffraction grating is the same as increasing the sampling frequency when acquiring electrical signals.In the case of thick films and interference spectra with superimposed noise, discrete sampling can be performed without loss of information. It is easy to measure the film thickness with high accuracy.
As an example, instead of the diffraction grating 96 in the film thickness measuring device, a wavelength resolution of 1.2 nm / point was used, and measurement was performed on an object to be measured having the configuration shown in FIG. The average variation in the measured film thickness value was 0.8 μm, and measurement with a resolution of 0.1 μm or less was not possible.

  Thus, at a resolution of 1.2 nm / point, when filler particles are dispersed in a wet film, sufficient spectrum acquisition is possible when the dispersed filler particles have a particle diameter or agglomerated diameter of 0.8 μm or less. Can not. On the contrary, the resolution: 0.1 nm or less is overspec, the calculation time of the curve fitting algorithm becomes long, and the area becomes too large.

  Further, when the diffraction grating 96 used in the above embodiment has a spectral region of 770 nm to 1050 nm, a measurement wavelength in a region suitable for film thickness measurement is ensured. By setting the region, it is possible to obtain an interference spectrum with high accuracy and not only to measure the film thickness with an accuracy of 0.1 μm but also to easily ensure the wavelength resolution of the diffraction grating.

  When the spectral region is less than 770 nm, the measurement wavelength region is smaller than the surface roughness of the rough tube, for example, Rmax. Therefore, the film on the laminated photosensitive hardened layer is affected by scattering and diffraction due to the surface roughness. When measuring the thickness or measuring the film thickness on a rough aluminum cutting drum, the spectral spectrum intensity for measuring the film thickness cannot be obtained. Further, when the spectral region exceeds 1050 nm, the interference spectrum cannot be acquired by the photodiode in the spectral region beyond this at the upper limit of the sensitivity range of the photodiode as the spectral intensity detection means.

  As described above, the wet film thickness measuring apparatus according to the present invention is configured by adding a filter that cuts light in an unnecessary wavelength region out of light emitted from a light source that emits spectrum light in a desired wavelength region. be able to.

FIG. 9 is a schematic diagram showing a configuration example of a film thickness measuring apparatus including a filter. In order to avoid complication, the same reference numerals as those in FIG. 5A are assigned to the same components and the like of the film thickness measuring apparatus shown in FIG.
The film thickness measuring device 9A shown in FIG. 9 differs from that shown in FIG. 5A in addition to the structure of the film thickness measuring device 9 shown in FIG. 5A from a light source that emits spectrum light in a desired wavelength region. The only difference is that the light source 91 has a filter 99 that cuts light in the unnecessary wavelength region out of the emitted light, and the other parts are the same as those shown in FIG.

  As the filter 99, for example, by using the above-described sharp cut filter that transmits light in the wavelength region of 770 to 1050 nm, a good film can be obtained without damaging the photoconductive photoconductor as a measurement target, such as light fatigue. Thickness measurement can be performed.

As described above, in the embodiment, the calculation is performed using the values in the wavelength region of 770 nm to 850 nm as the wavelengths λ _2m and λ _{2m + 1} that give the minimum and maximum in the spectral spectrum intensity.

  As described above, the spectral refractive index data of the wet film can use the “spectral refractive index data relating to the material (wet state) forming the wet film to be measured” in the calculation unit 98 of the film thickness measuring device 9A. In order to increase the versatility of the film thickness measurement device and adapt to multiple types of light-transmitting wet layers, the calculation means “forms a wet film that can be measured for film thickness”. It is preferable to store one or more kinds of spectral refractive index data relating to the material (wet state).

Next, a method for producing a photoconductive photoreceptor in the present invention will be described.
In the method for producing a photoconductive photoreceptor in the present invention, an intermediate layer forming step in which a coating liquid containing a binder resin and fine particles is applied on a support substrate composed of a conductive substrate, dried and cured to form an intermediate layer, Applying a coating liquid containing a photoconductive substance and a binder resin on the intermediate layer, drying and curing to form a photosensitive cured layer, and a coating comprising the intermediate layer and the photosensitive cured layer A coating liquid containing a photocrosslinking type polymerizable resin that has charge transportability and is polymerized and cured by the application of light energy and a solvent is applied to the surface of the object by a spray coating method, and a light-transmitting wet film is formed. A wet coating film according to any one of claims 1 to 7, wherein a sprayed coating step and a coated product on which the light-transmitting wet film is formed are used as a measurement object. A film thickness measurement process for measuring by applying a thickness measurement method, and the above The wet film is cured by applying light energy to the wet film after the thickness measurement process, and is further cured to form a surface layer. The spray is based on the film thickness of the wet film measured in the film thickness measurement process. The spray coating process is executed while controlling the coating conditions.
In addition, the film thickness measuring method applied to a film thickness measuring process shall be implemented with the film thickness measuring apparatus of the said wet film | membrane of this invention.

That is, the photoconductive photoreceptor produced by each of the above steps comprises a structure having a surface layer obtained by curing an intermediate layer, a photosensitive cured layer, and a light-transmitting wet film on a support substrate. In this case, the photosensitive layer has a single layer structure containing a charge generating substance and a charge transporting substance simultaneously as a photoconductive substance.
Further, the photosensitive cured layer forming step includes applying a coating solution containing a charge generating material and a binder resin, drying and curing the coating layer to form a charge generating layer, and forming a charge on the charge generating layer. A photoconductive photoreceptor produced by a charge transport layer forming step in which a coating liquid containing a transport material and a binder resin is applied and dried and cured to form a charge transport layer can also be obtained.
In this case, on the support substrate, the intermediate layer, the charge generation layer, the charge transport layer, and the surface layer obtained by curing the light-transmitting wet film, the photosensitive cured layer in this case, The stacked structure is functionally separated into a charge generation layer and a charge transport layer.

As a coating liquid coating method for producing a photoconductive photoreceptor, a dip coating method, a ring coating method, a spray coating method, and the like are known. When applying a coating liquid (substantially, photocrosslinking type charge transport layer coating liquid) containing a photocrosslinking polymerizable resin and a solvent that is polymerized and cured by application to form a light transmissive wet film, The dip coating method and the ring coating method have many technical difficulties.
In contrast, the spray coating method can form a predetermined coating film on various substrates with a small amount of coating liquid, and it is relatively easy to control the physical properties of the coating liquid and to maintain and manage the coating apparatus. Even in the case of the photocrosslinking type charge transport layer coating solution, a uniform film can be formed by coating.

If the film thickness of the photoconductive photoconductor after applying wet film, curing with light energy, and further drying, so-called product surface layer, changes the electrical characteristics of the photoconductor, causing abnormal images It also becomes.
On the other hand, by providing the film thickness measuring step according to the method for measuring the film thickness of the wet film of the present invention, the film thickness of the wet film during the manufacturing process can be monitored in a wet state. It is possible to grasp the state of the film during the process, and based on this, it becomes possible to adjust the coating liquid properties or coating conditions.
That is, in the process of producing a photoconductive photoconductor, the wet film thickness (distance between the outermost surface of the wet film and the outermost surface of the photosensitive cured layer) is measured by a film thickness measuring device, and the measured wet film The layer thickness of the cured film (surface layer) can be estimated based on the thickness. Based on this estimation result, during spray coating or standing drying, it can be reflected as the application condition of the immediately subsequent spray coating process, and by adjusting the coating amount by controlling the spray application condition in the subsequent spray coating process Thus, it is possible to improve the film thickness uniformity of the surface layer of the photoconductor and to produce a photoconductive photoconductor having stable image quality. In addition, productivity can be improved and the yield rate can be improved.

In the method for producing the photoconductive photoreceptor, a conductive base having a cylindrical shape or a belt shape is used. Then, the wet film thickness measurement in the film thickness measurement process is performed at multiple points along the direction of the rotation axis of the cylindrical or belt-like conductive substrate, and the spray coating conditions are controlled based on the film thickness distribution. However, by executing the spray coating process, it is possible to improve the uniformity of the surface layer and obtain a good photoconductive photoreceptor.
When measuring multi-point wet film thickness in the axial direction of the conductive substrate, generally, in the spray coating process, the film thickness in the circumferential direction of the conductive substrate is almost the same by spin coating. The film thickness profile in the axial direction can be known, and it is easy to estimate the film thickness profile in the axial direction when the surface layer is dried and hardened. Based on this estimation result, the uniformity of the surface layer serving as the photocrosslinking charge transport layer can be improved by controlling the coating conditions in the subsequent spray coating process and adjusting the coating amount.

  In the above manufacturing method, if the physical properties of the coating liquid, the spray coating apparatus, the conductive substrate, and the like are the same, the wet film thickness in spray coating changes according to the discharge amount. Specifically, the film thickness increases as the discharge amount increases and decreases as the discharge amount decreases. Therefore, the spray coating film thickness can be controlled with high accuracy by controlling the discharge amount.

  Thus, when performing film thickness measurement by a manufacturing method involving a spray coating process, the objective lens constituting the condensing optical system used in the film thickness measuring device is under the condition of lens diameter: φ25 mm to 30 mm, It is preferable that the light is vertically incident at a distance of 50 mm to 70 mm from the surface of the object to be measured.

Since the objective lens is used to increase the convergence / condensation of light onto the object to be measured, the use of a large-diameter lens can increase the convergence / condensation. The basic principle of “vertical light reception” is broken. For this reason, the measurement light enters obliquely with respect to the wet film of the object to be measured, resulting in a measurement error. By configuring the measurement light to be perpendicularly incident, even in the spray coating process, it is possible to ensure a sufficient focusing degree and light collecting property of the measurement light without being affected by the coating liquid.
Also, if the objective lens is too close to a wet film, the spray coating solution diffuses in the spray coating process and is applied to the objective lens, which may cause the objective lens to become dirty and reduce the measurement detection power. This problem can be solved by separating the objective lens from the object to be measured. However, if the objective lens is separated too much, the amount of light returning to the objective lens is reduced, which hinders film thickness measurement.

The spray coating process performed in the method for producing a photoconductive photoreceptor of the present invention can be performed using a known spray coating apparatus.
In order to estimate the film thickness of the surface layer formed by curing the wet film by light energy, the film thickness of the wet film formed by spray coating and the film thickness of the surface layer cured by light energy and further dried By obtaining the correlation in advance, the cured film thickness can be estimated in the manufacturing process. That is, coating with various discharge amounts using a coating solution for a wet film, measuring the formed wet film thickness and cured film thickness with a film thickness measuring device, and accumulating correlation data regarding the film thickness, With reference to this, the cured film thickness corresponding to the wet film thickness measured in the manufacturing process can be estimated.

  In that case, the wet film thickness after the spray coating process changes over time during standing drying, but if the liquid physical properties and the standing drying conditions are the same, the behavior of the wet film thickness over time will be the same and the same. If the time has elapsed, the influence on the film thickness fluctuation is small. Although the wet film thickness can be measured during spray coating, the film thickness can be measured with high accuracy by measuring the film thickness after standing for a certain period of time.

  The standing drying time in this case may be set so that the estimated result based on the measured wet film thickness can be fed back to the next spray application, and is the time from immediately after spray application to the time immediately before the next spray application. Is set. Specifically, it is set to 1 to 30 minutes, preferably 2 to 3 minutes. If it is shorter than 1 minute, “vaporization of the solvent by natural drying from the wet film” is insufficient, and the change in the film thickness by natural drying is the most severe, so that the variation in the film thickness measurement becomes large. If it is longer than 30 minutes, feedback to the next spray coating process will not be in time.

  In the film thickness measurement process of the wet film, it is necessary to finish the measurement in as short a time as possible in order to reduce the measurement error due to the film thickness decrease immediately after the spray coating process. 30 points at a pitch of 10 mm in the axial direction of the conductive substrate can be measured in about 15 to 45 seconds.

The photoconductive photoreceptor produced by the production method of the present invention will be described with the configuration shown in FIG. 4 as a representative example.
In the photoconductive photoreceptor shown in FIG. 4, an intermediate layer 3a is formed on a conductive substrate 2a, a charge generation layer 3b ₁ and a charge transport layer 3b ₂ are laminated thereon, and the wet film is further photocured to further cure. The surface layer 5a is formed by drying. Surface layer 5a is made by forming a photo-crosslinking type charge transporting layer on the surface side of the charge transport layer 3b _2. That is, the photosensitive layer 6 is composed of a charge generating layer 3b ₁ charge transport layer 3b ₂ and the surface layer 5a.

[Conductive substrate]
As the conductive substrate, various known substrates such as a metal substrate such as an aluminum tube and a nickel belt, a plastic belt, and the like can be used.
The aluminum tube can be subjected to surface processing such as cutting, ironing, drawing, etc., the nickel belt is a belt-like metal substrate formed by deposition in the same manner as plating, and the plastic belt is formed by vapor deposition of aluminum on a polyester film. A conductive resin coat is applied to form a conductive belt. The conductive substrate shown in FIG. 4 is, for example, an aluminum drum.

[Middle layer]
The intermediate layer 3a has a function as a binder that adheres and fixes the photosensitive layer to the conductive substrate, and contains fine pigment particles in order to suppress adverse effects such as uneven charging. That is, the intermediate layer 3a has a configuration in which fine particles are dispersed in a binder resin (binder resin).

  As the binder resin, use is made of thermoplastic resins such as acrylic resin, vinyl acetate resin, polyvinyl alcohol, nitrocellulose, polyamide, and polyvinyl chloride, and thermosetting resins such as polyurethane, alkyd resin, melamine resin, and alkyd melamine resin. it can. Of these, alkyd resins, melamine resins, acrylic resins, vinyl acetate resins and the like having a small refractive index are preferable.

  The layer thickness of the intermediate layer 3a is generally 2 to 6 μm, but the layer thickness of the intermediate layer 3a is 3 μm or more in order to achieve a sufficient function as a binder and a good light shielding effect on the conductive substrate. It is preferable that

  As particles dispersed in the intermediate layer 3a, 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 used in terms of dispersibility and electrical characteristics. Is preferred. As the titanium oxide, any of rutile type and anatase type can be used, but as the colorless transparent pigment, rutile type titanium oxide having a large refractive index is preferable.

The fine particles dispersed in the intermediate layer 3a are preferably colorless and transparent pigments that are white in a powder state in consideration of increasing the surface reflectance, and have a rear surface concealing power, that is, a light shielding power against a conductive substrate. If it is colorless and transparent, there is no selective wavelength absorption, so surface reflection and internal multiple refraction are possible in the entire visible region, which makes it a good interference spectrum even when measuring the thickness of the 3b ₂ charge transport layer. Can be acquired.

  In order to realize the intermediate layer 3a as described above, for example, the above-described binder resin is dissolved in an organic solvent, and the above-mentioned particles are dispersed in the solution by means of a ball mill, a sand mill, or the like to form a coating liquid. What is necessary is just to apply | coat and dry on a conductive substrate.

(Charge generation layer)
The charge generation layer 3b ₁ is a layer that generates positive and negative charge pairs by irradiation with a specific wavelength, and the charge transport layer 3b ₂ has a predetermined polarity out of the charges generated in the charge generation layer 3b ₁ to the photosensitive layer surface. Has the ability to transport. The charge generation layer 3b ₁ is composed of a charge generation material as a main component and a binder resin added as necessary. As the charge generation material, either an inorganic material or an organic material can be used. The layer thickness of the charge generation layer 3b ₁ is preferably 1 μm or less.

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

  Examples of organic materials 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, and diphenylamine skeletons. Azo pigments, azo pigments having a dibenzothiophene skeleton, azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, distyrylcarbazole skeleton Azo pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and Zomechin pigments, indigoid pigments, vicinal benzimidazole pigments, may be known materials. These charge generation materials can be used alone or as a mixture of two or more.

  Binder resins used as necessary include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide, and the like. Can be mentioned. These binder resins can be used alone or as a mixture of two or more.

  When an optical scanning device using laser light is used as the exposure means in the image forming apparatus, the laser light is internally reflected on the surface of the conductive substrate, the surface of the intermediate layer, or the surface of the photosensitive layer and interferes inside the photosensitive layer, thereby Interference patterns may appear on the top. In order to avoid such a problem, it is effective to roughen the surface of the conductive substrate by cutting or the like, or to disperse fine pigment particles in the intermediate layer to cause irregular reflection.

A charge transport material may be added to the charge generation layer 3b ₁ as necessary.
The method of forming the charge generation layer 3b ₁ is roughly classified into a vacuum thin film manufacturing method and a casting method from a solution dispersion system. Vacuum thin film preparation methods include vacuum deposition, glow discharge decomposition, ion plating, sputtering, reactive sputtering, CVD, etc., and the charge generation layer using the inorganic or organic materials described above Can be formed satisfactorily.

In order to form the charge generation layer 3b ₁ by a casting method, the above-described inorganic or organic charge generation material is ball milled using a binder resin and a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone, if necessary. What is necessary is just to disperse | distribute by an attritor, a sand mill, etc., and to dilute and apply | coat a dispersion liquid appropriately and to dry.
As a coating method, a dip coating method, a spray coating method, a beat coating method, or the like can be used. The film thickness of the charge generation layer 3b ₁ is suitably 1 μm or less, preferably in the range of 0.01 to 1 μm, particularly preferably in the range of 0.05 to 0.5 μm.

(Charge transport layer)
The charge transport layer 3b ₂ is mainly composed of a charge transport material, and the charge transport material and, if necessary, a binder resin are dissolved in an appropriate solvent such as tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, cyclohexanone, etc. Alternatively, it can be formed by applying and drying a dispersed coating solution (solution or dispersion). A plasticizer, a leveling agent, etc. can also be added to the charge transport layer 3b ₂ as necessary.

Charge transport materials include hole transport materials and electron transport materials.
Examples of the electron transport material include chloroanil, bromanyl, 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-dimethyl Known electron-accepting substances such as -3 ', 5'-dita-shearary butyl-4,4'-diphenoquinone can be mentioned. 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-diethylaminostyrylanthracene), 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene. , Styrylpyrazolines, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzfuran derivatives, benzimidazole derivatives, thiophone derivatives, and the like. It can be used alone or as a mixture of two or more.

The binder resin used for the charge transport layer 3b ₂ includes polycarbonate (bisphenol A type, bisphenol Z type, etc.), polyester, methacrylic resin, acrylic resin, polyethylene, vinyl chloride, vinyl acetate, polystyrene, phenol resin, epoxy resin, polyurethane. Polyvinylidene chloride, alkyd resin, silicone resin, polyvinyl carbazole, polyvinyl butyral, polyvinyl holmar, polyacrylate, polyacrylamide, phenoxy resin, and the like can be used.
As the binder resin, a polymer charge transport material having a function as a binder resin and a function as a charge transport material can also be used. Such polymer charge transport materials include, for example, a polymer having a carbazole ring in the main chain and / or side chain, a polymer having a hydrazone structure in the main chain and / or side chain, a polystyrene polymer, a main chain and Examples thereof include a polymer having a tertiary amine structure in the side chain.

These binder resins can be used singly or as a mixture of two or more. The amount of the binder resin used is suitably 0 to 150 parts by weight with respect to 100 parts by weight of the charge transport material.
The allowable thickness of the charge transport layer is about 5 to 100 μm, but is preferably about 15 to 35 μm.

  Incidentally, an antioxidant can be added to the constituent layer of the photoconductive photoreceptor in the present invention for the purpose of preventing 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 transport material. In this case, even when an antioxidant is added, the detection of the interference spectrum is hardly affected.

[Surface layer]
The surface layer 5a is formed by applying light energy to the wet film 5 formed using a coating solution containing a photocrosslinking resin having a so-called charge transporting molecular structure and a solvent, and further drying and curing.
The surface layer 5a can contain the above-mentioned additives and dispersed particles, whereby the wear resistance can be improved.

Hereinafter, the formation of the surface layer 5a will be described along the spray coating process.
A photocrosslinking resin having a charge transporting property on the surface of a coating object having a photoconductive substance and a photosensitive cured layer containing the binder resin (charge transporting layer 3b ₂ ) on an intermediate layer containing the binder resin and fine particles; When spraying a coating solution for a wet film containing a solvent, even if spray coating is performed using a coating solution containing a solvent that does not dissolve the photosensitive cured layer, the coating is not compatible at each layer interface. When the charge transport layer 3b ₂ and the wet film (the surface layer 5a is formed by photocuring) are incompatible, the charge transport layer 3b ₂ and the surface layer 5a have a discontinuous layer structure, and a clear interface is formed between the respective layers. It is formed.

The layer thickness of the surface layer 5a formed by curing the spray-coated wet film 5 with light energy and further drying is preferably 0.1 to 10 μm, more preferably 1 to 10 μm, and particularly preferably 2 to 2 μm. 8 μm.
When the layer thickness is less than 0.1 μm, the surface hardness and strength are not sufficient and the durability is poor. On the other hand, when the layer thickness exceeds 10 μm, the electrostatic latent image formed by optical scanning or optical writing is developed. Dot reproducibility decreases when visualized.
Incidentally, the preferable thickness as the photosensitive layer 6 is 18 to 46 μm.

If necessary, a charge transport material may be added to the coating liquid for the wet film used as the surface layer 5a.
Examples of charge transport materials include hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triarylmethane compounds.

FIG. 10 is a schematic view conceptually showing an example of a manufacturing apparatus for carrying out the method for manufacturing a photoconductive photoreceptor.
Reference numeral 100 denotes a coating object (for example, a photoconductive photosensitive member having the structure shown in FIG. 4) in which an intermediate layer 3 a, a charge generation layer 3 b ₁ , and a charge transport layer 3 b ₂ are sequentially provided on a conductive substrate 2 a ( In the spray coating process, a wet film coating solution is applied to the surface of the spray object to form a wet film, and the next wet film curing process. Then, light energy is applied to the wet film, and it is further dried and cured to form the surface layer 5a.

  Reference numeral 111 denotes a spray gun in the spray coating apparatus. The spray gun 111 is supplied with the coating liquid stored in the liquid tank 113 by the liquid feed pump 112 and performs spray coating on the spray target object 100. At this time, the spray object 100 is rotated at a constant speed around the axis, and the spray gun 111 sprays while moving at a constant speed in the direction of the axis. Spray coating is effected by performing spraying a plurality of times.

  Reference numeral 120 denotes a film thickness measuring apparatus, and the film thickness measuring apparatus 9A shown in FIG. 9 is used here. That is, in the film thickness measuring apparatus 120, the configuration of each part excluding the filter 99 shown in FIG. 9 is the same as that described above with reference to FIG. That is, the objective lens 94 is an achromatic lens having a lens diameter of 25.4 mm and a focal length of 30 mm, and is disposed at a position 70 mm away from the surface of the spray target 100. The filter 99 is a sharp cut filter that transmits the light in the wavelength region of 720 to 1050 nm.

  The film thickness measuring device 120 is movable in the axial direction of the spray object 100. That is, in the spray coating process, while the spray object 100 is rotated, the spray gun 111 is moved in the axial direction to perform spraying, and after the wet film is formed by spraying, it is left to dry for 2 minutes as described above. Then, the film thickness measuring device 120 is moved in the axial direction of the spray object 100 and, for example, film thickness measurement (multi-point measurement) is performed at 30 positions at intervals of 10 mm.

  The result of the film thickness measurement is input to the calculation means 121. The calculation means 121 determines the dry cured film corresponding to the measured wet film thickness from the correlation between the measured wet film thickness and the dry cured film thickness in accordance with the film thickness measurement result of the wet film formed by the spray. The thickness is estimated, and the subsequent spraying is continued to determine the discharge amount of the coating liquid so that a desired film thickness is obtained.

  The discharge amount determined in this way is input to the control means 122 (configured by a microcomputer together with the calculation means 121), and the control means 122 controls the liquid feed pump 112 when performing subsequent spraying, Spray is performed according to the discharge amount. After the measurement of the wet film thickness, the spray object 100 is subsequently photocrosslinked and cured by a light energy irradiation device to cure the wet film, and further dried at 130 ° C. for 20 minutes to form a surface layer.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not restrict | limited by these Examples. “Parts” are all in weight units.

(Example)
A photoconductive photoconductor having the structure shown in FIG. 4 was produced using a photoconductive photoconductor manufacturing apparatus equipped with a film thickness measuring apparatus for carrying out the film thickness measuring method of the present invention shown in FIG. .

[Conductive substrate]
A cut aluminum base tube (tube whose peripheral surface was roughened by cutting) having a tube diameter of φ100 mm was prepared as the conductive substrate 2a as a support.

[Middle layer]
Titanium oxide (particles having an average particle size of 0.25 μm) as a colorless transparent pigment, 70 parts by weight, alkyd resin (trade name: Beckolite M6401-50-S (solid content 50%): manufactured by Dainippon Ink & Chemicals, Inc.) 15 10 parts by weight of melamine resin (trade name: Super Becamine L-121-60 (solid content 60%): manufactured by Dainippon Ink and Chemicals) and 100 parts by weight of methyl ethyl ketone are mixed, and the mixture is dispersed with a ball mill for 72 hours. Thus, an intermediate layer coating solution was obtained.
This coating solution was applied to the aluminum base tube by a dipping method and dried at a temperature of 130 ° C. for 20 minutes to form an intermediate layer 3a forming a hardened layer having a thickness of 3.5 μm.

[Charge generation layer]
10 parts by weight of a trisazo pigment represented by the following structural formula (a) is added to a resin 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. After time dispersion, 210 parts by weight of cyclohexanone was added and dispersed for 3 hours to obtain a charge generation layer coating solution having an absorption peak at 900 nm or less. This charge generation layer coating solution is applied on the intermediate layer 3a by the “dipping method” and dried at a temperature of 130 ° C. for 10 minutes to form a charge generation layer 3b ₁ having a thickness of 0.2 μm. did.

[Charge transport layer]
Next, 7 parts by weight of a charge transport material represented by the following structural formula (b), 10 parts by weight of a polycarbonate resin (Iupilon Z200: manufactured by Mitsubishi Gas Chemical Company), silicone oil (KF-50: manufactured by Shin-Etsu Chemical Co., Ltd.) A charge transport layer coating solution in which 002 parts by weight is dissolved in 100 parts by weight of tetrahydrofuran is applied onto the charge generation layer 3b1 by dipping and dried at a temperature of 130 ° C. for 20 minutes to obtain a cured layer having an average film thickness of 22 μm. to form a charge transport layer 3b ₂ forming a.

  As described above, the spray object 100 shown in FIG. 10 was obtained. Next, a wet film 5 was formed by spray coating the surface of the spray object using a wet film coating liquid having the following composition (a coating liquid containing a photocrosslinking resin having a charge transporting molecular structure). .

[Wetting film coating solution]
Trifunctional or more radical polymerizable monomer having no charge transporting structure <Trimethylolpropane triacrylate (KAYARAD TMPTA, Nippon Kayaku Co., Ltd.) molecular weight: 296, functional group number: trifunctional, molecular weight / functional group number = 99>: 10 Part Radical polymerizable compound having a monofunctional charge transporting structure represented by the following structural formula (c): 10 parts Photopolymerization initiator <1-hydroxy-cyclohexyne-phenyl-ketone (Irgacure 184, Ciba Specialty Chemicals) Manufactured) >>: 1 part Tetrahydrofuran: 100 parts

When spraying the wet film, data on the correlation between the wet film thickness measured in advance and the dry film (surface layer) ("data relating to the coating liquid for the surface layer") is input to the calculation means 121 and sprayed. The discharge amount of the coating liquid was determined so as to obtain a desired film thickness by continuing the above.
Specifically, the film thickness in a wet state after the lapse of 2 minutes after the end of spraying with respect to the discharge amount, the film thickness after curing by light energy, and heat were measured, and the correlation between these was grasped and input.
That is, after the film thickness between the outermost surface of the charge transport layer 3b _{2 and} the outermost surface of the surface layer 5a of the photoconductive photoreceptor finally obtained is set to 8 μm and the wet film coating solution is sprayed. Wet film and film thickness were measured, and the optimum spray discharge amount was calculated from the measurement results, and the discharge amount in the subsequent spray was controlled. After each photoconductor was obtained, the discharge amount data at the time of manufacturing the photoconductor was reflected in the discharge amount of the next photoconductor. In this manner, 50 photoconductive photoreceptors were prepared in succession.

When the film thickness of the surface layer 5a of the photoconductive photoreceptor produced as described above, that is, the distance between the outermost surface of the charge transport layer 3b _{2 and} the outermost surface of the surface layer 5a was measured, the obtained film thickness was It was within the range of 8 μm ± 0.5 μm and was constant. Some of the results are shown in Table 1 below.

(Comparative Example 1)
On the other hand, in the examples, photoconductive photoreceptors were produced under exactly the same conditions as in the examples except that the wet film was formed by fixing the spray discharge amount of the wet film coating liquid to 7.5 cc / min. That is, in the case of the comparative example, since the film thickness control step of the wet film is omitted, the film thickness of the surface layer to be cured is not controlled and managed.
The results are shown in Table 2 below.

In the embodiment of the present invention for controlling the spray discharge amount shown in Table 1, the film thickness of the surface layer is surely formed with high accuracy. On the other hand, when the spray discharge amount shown in Table 2 is not controlled, the surface is increased as the number of production increases. The film thickness of the layer decreased, and the predetermined quality could not be achieved after 15 lines.
The spray coating liquids used in the examples and comparative examples change in physical properties over time, and the quality cannot be maintained unless the discharge rate is increased with the increase in the number of productions. By providing the film thickness measurement step and adjusting the discharge amount based on the film thickness measurement, a photoconductive photoconductor of good quality can be manufactured.

(Comparative Example 2)
In the wet film thickness measurement method and film thickness measurement apparatus according to the present invention, the spectral light emitted from the fiber probe 93 is condensed on the light transmissive wet film by the objective lens 94 constituting the condensing optical system. I am letting. On the other hand, in this comparative example, instead of condensing using the condensing optical system, the fiber probe 93 is brought close to the distance of 0.5 mm from the surface of the light-transmitting wet film as shown in FIG. The emitted light is directly incident on the surface of the object 10 to be measured. The obtained reflectance was as shown in FIG.
As is apparent from FIG. 8, the obtained reflectance curve has a very small vibration amplitude (difference between the maximum value and the minimum value), and it is difficult to obtain the wavelengths: λ _2m and λ _{2m + 1} , and therefore the wet film It can be seen that it is difficult to accurately measure the film thickness.

(Comparative Example 3)
In the method for measuring the thickness of the wet film in the present invention, it is used to expand the spectral spectrum intensity obtained by spectroscopy to an arbitrary size, but in this comparative example, in the calculation means Using a Si-wafer (standard sample) with a known reflectance, the spectral intensity obtained by the spectroscopic means was calibrated as per theory without reducing the actual amount of reflected light, and the wet film thickness was measured. . The obtained reflectance was as shown in FIG.
As is apparent from FIG. 12, the obtained reflectance curve has an extremely small amplitude, the curve fitting of the theoretical reflectance curve does not work well, and it is difficult to obtain the wavelengths: λ _2m , λ _{2m + 1} , and therefore wet. It can be seen that it is difficult to accurately measure the film thickness.

It is a schematic structure sectional view of a to-be-measured object in a film thickness measuring method of a wet film of the present invention. FIG. 2 is a schematic cross-sectional view of a measured object having a layer structure in which a support substrate of FIG. 1 is a conductive substrate 2a, a cured layer 3 is an intermediate layer 3a, and a photosensitive layer 3b is sequentially provided on the intermediate layer 3a. FIG. 3 is a schematic cross-sectional view of a measured object having a photosensitive layer 3b of FIG. 2 having a stacked configuration in which a charge generation layer 3b ₁ and a charge transport layer 3b ₂ are sequentially provided. FIG. 3 is a schematic cross-sectional view of a photoconductive photoreceptor in which the wet film 5 of FIG. 3 is a coating film formed with a photocrosslinking resin-containing coating solution and is cured by light energy to form a surface layer 5a. It is the schematic which shows the structural example (a) of the apparatus which performs the film thickness measuring method of this invention, and the objective lens side edge part (b) of a fiber probe. 7 is a graph showing continuous spectral spectrum intensities obtained by calculating the data detected by the spectrum intensity detecting means 97 by the non-linear least square method in the calculating means 98; It is a graph which shows the relationship between the refractive index and wavelength which show the specific example of 1 or more types of spectral-refractive-index data regarding the material which forms the wet film | membrane which can be a film thickness measurement object. 6 is a graph showing the spectral spectrum intensity of detection light when the emission end of the fiber probe 93 is brought close to the surface of the photosensitive layer and the emission light is directly irradiated on the surface of the object to be measured 10. It is the schematic which shows the structural example of the film thickness measuring apparatus provided with the filter. It is a schematic diagram which shows roughly an example of the manufacturing apparatus for enforcing the manufacturing method of a photoconductive photoreceptor. The film thickness measurement process figure in the comparative example 2 is shown. It is a graph which shows spectrum spectrum intensity at the time of calibrating spectrum spectrum intensity using Si-wafer (standard sample) with a known reflectance.

Explanation of symbols

2 Support Substrate 2a Conductive Substrate 3 Cured Layer 3a Intermediate Layer 3b Photosensitive Cured Layer 3b ₁ Charge Generation Layer 3b ₂ Charge Transport Layer 4 Application Object 5 Light Transmittable Wet Film (Wet Film)
5a Surface layer 6 Photosensitive layer 9 Film thickness measuring device 9A Film thickness measuring device 10 Coated object (object to be measured)
DESCRIPTION OF SYMBOLS 20 Photoconductive photoreceptor 91 Light source 92 Optical transmission fiber 93 Fiber probe 94 Objective lens 95 Lens tube 96 Spectroscopic means 97 Spectral intensity detection means 98 Calculation means 99 Filter 100 Spray object 111 Spray gun 112 Liquid feed pump 113 Liquid tank 120 Film thickness measuring apparatus 121 Calculation means 122 Control means 930 Irradiation light guiding fiber

Claims (23)

On the surface of the coating object on which a cured layer containing at least a cured resin is provided in advance on a support substrate, a coated object in which a light-transmitting wet film is formed with a coating liquid containing a polymerizable resin and a solvent is coated. A method for measuring the thickness of a wet film in the measurement object, which is a measurement object,
The film thickness of the wet film is
The light from the light source that radiates spectrum light in the desired wavelength region is guided by the irradiation light guiding fiber disposed in the fiber probe, and is emitted from the emission part,
This radiated light beam is vertically incident on the object to be measured by the objective lens of the condensing optical system and condensed on the wet film,
The reflected light reflected and interfered with each other at the outermost surface of the wet film and the outermost surface of the hardened layer is returned to the end surface of the detection light transmission fiber disposed in the fiber probe via the objective lens, and the detection light transmission is performed. Led to the spectroscopic means with a fiber for spectroscopy,
A wet film thickness measurement method, comprising: calculating and calculating a wet film thickness based on the obtained wavelengths and the respective wavelengths that give the minimum and maximum spectral spectrum intensity and the refractive index of the wet film.   The method for measuring a thickness of a wet film according to claim 1, wherein the spectral wavelength range of the spectroscopic means is 770 to 1050 nm.   The wet film thickness measuring method according to claim 1 or 2, further comprising a calibration method for enlarging a spectral spectrum intensity obtained by spectroscopy to an arbitrary magnitude in the calculation calculation.   4. The calibration method according to claim 3, wherein the obtained spectral spectrum intensity that is oscillated is calibrated to an arbitrary size by calibrating the actual reflected light amount by using a standard sample having a known reflectance. The film thickness measuring method of the described wet film. In the coating object,
The support substrate is a conductive substrate, the cured layer containing a cured resin is an intermediate layer containing fine particles dispersed in a binder resin, and a photosensitive material containing a photoconductive substance and a binder resin on the intermediate layer. The wet film thickness measuring method according to any one of claims 1 to 4, wherein the wet film has a layer structure in which a hardened layer is sequentially provided.   2. The photosensitive cured layer has a laminated structure in which a charge transport layer containing a charge transport material and a binder resin is sequentially provided on a charge generation layer containing a charge generation material and a binder resin. The method for measuring a film thickness of the wet film according to any one of claims 1 to 5.   The light-transmitting wet film is a coating film having a charge transporting molecular structure and a coating solution containing a photocrosslinking polymerizable resin that is polymerized and cured by the application of light energy and a solvent. The method for measuring a thickness of a wet film according to any one of claims 1 to 6. A film thickness measuring apparatus that implements the method for measuring a film thickness of a wet film in a measurement object according to any one of claims 1 to 7,
The film thickness measuring device is
A light source that emits spectral light in a desired wavelength region;
The light from the light source is guided to the measured object side by the irradiation light guiding fiber, radiated from the emission part toward the measured object side, and the reflected light from the measured object is received by the detection light transmission fiber. A fiber probe to transmit,
An objective lens of a condensing optical system that vertically irradiates the irradiation light emitted from the emission portion of the fiber probe and condenses the light toward the light-transmitting wet film;
Reflected light reflected and interfered with each other on the wet film outermost surface and the hardened layer outermost surface of the object to be measured is transmitted by the detection light transmission fiber through the objective lens of the condensing optical system, and the transmitted detection light is transmitted. Spectroscopic means for spectroscopic analysis;
Spectral intensity detection means for detecting the spectral intensity of the detection light split by the spectroscopic means, and calculation means for calculating a reflectance from the spectral spectrum intensity, the calculation means being obtained by the spectral intensity detection means. When calculating the reflectance curve using the reflected light, the reflectance curve is calibrated using a standard sample with a known reflectance, with the actual amount of reflected light being reduced, and is minimized from the spectral spectrum intensity. And calculating the film thickness of the light-transmitting wet film on the object to be measured using the wavelength at which the reflectance curve is minimum and maximum and the refractive index of the light-transmitting wet film. A film thickness measuring apparatus comprising a calculating means for calculating.   The film thickness measuring apparatus according to claim 8, wherein the condensing optical system has a numerical aperture (NA) of 0.3 or less.   The film thickness measuring apparatus according to claim 8 or 9, wherein the objective lens is an achromatic lens.   The film thickness measuring apparatus according to any one of claims 8 to 10, wherein the light source is a halogen-tungsten lamp.   The film thickness measuring device according to any one of claims 8 to 11, wherein the spectroscopic means is a diffraction grating, a prism, or a spectroscopic filter.   The film thickness measuring device according to any one of claims 8 to 12, wherein the spectrum intensity detecting means is a line sensor or a silicon photodiode array.   The end facing the objective lens side of the fiber probe is centered on the reflected light receiving end face of the detection light transmission fiber, and is configured so that the end face of the emission part of the irradiation light guiding fiber is surrounded by this. The film thickness measuring device according to any one of claims 8 to 13, characterized in that   The said calculating means has memorize | stored one or more types of spectral-refractive-index data regarding the light-transmitting wet film | membrane which can become a measuring object so that utilization is possible. Film thickness measuring device.   The film thickness measuring device according to any one of claims 8 to 15, further comprising a filter that cuts light in an unnecessary wavelength region out of light emitted from the light source. An intermediate layer forming step in which a coating liquid containing a binder resin and fine particles is applied onto a support substrate made of a conductive substrate, dried and cured to form an intermediate layer,
A photosensitive cured layer forming step of applying a coating liquid containing a photoconductive substance and a binder resin on the intermediate layer, and drying and curing to form a photosensitive cured layer;
A coating liquid containing a photocrosslinking polymerizable resin that has charge transportability and is polymerized and cured by the application of light energy and a solvent is spray-coated on the surface of the coating object composed of the intermediate layer and the photosensitive cured layer. A spray coating process that is applied by a construction method to form a light transmissive wet film,
The coated material on which the light-transmitting wet film is formed is a measurement object, and the wet film thickness measurement method according to any one of claims 1 to 7 is applied to the wet film thickness. A film thickness measurement process to be measured;
After the film thickness measurement step, the wet film is cured by applying light energy, further dried, and provided with a wet film curing step as a surface layer,
A method for producing a photoconductive photoconductor, comprising performing a spray coating process while controlling the spray coating conditions based on the film thickness of a wet film measured in the film thickness measurement process. The photosensitive cured layer forming step is a charge generating layer forming step in which a coating liquid containing a charge generating material and a binder resin is applied, dried and cured to form a charge generating layer,
The charge transport layer forming step according to claim 17, further comprising: applying a coating liquid containing a charge transport material and a binder resin on the charge generation layer, drying and curing the charge transport layer to form a charge transport layer. A method for producing a photoconductive photoreceptor.   The conductive substrate is cylindrical or belt-shaped, and the film thickness measurement of the wet film in the film thickness measurement step is performed at multiple points along the rotation axis direction of the cylindrical or belt-shaped conductive substrate. The method of manufacturing a photoconductive photoreceptor according to claim 17 or 18, wherein the spray coating step is executed while controlling the spray coating conditions based on the film thickness distribution.   20. The coating amount is adjusted by controlling the discharge amount of the coating liquid in the spray coating process based on the wet film thickness measured in the film thickness measurement process. The method for producing a photoconductive photoreceptor according to one item. The outermost surface layer after the wet film curing step in which light energy is applied to the wet film applied to the surface of the coating object consisting of the intermediate layer and the photosensitive cured layer, and then cured to form a surface layer by drying. And the distance between the outermost surface of the photosensitive cured layer,
The light from the light source that radiates spectrum light in the desired wavelength region is guided by the irradiation light guiding fiber disposed in the fiber probe and emitted from the emission part,
This radiated light beam is vertically incident on the object to be measured by the objective lens of the condensing optical system and condensed on the wet film,
The reflected light reflected and interfered with each other on the outermost surface layer and the photosensitive hardened layer outermost surface is returned to the end face of the detection light transmission fiber disposed on the fiber probe via the objective lens, and the detection light transmission is performed. Led to the spectroscopic means with a fiber for spectroscopy,
21. The method of claim 17, further comprising a step of calculating and measuring based on each wavelength that gives the minimum and maximum of the obtained spectral spectrum intensity and the refractive index of the surface layer. A method for producing a photoconductive photoreceptor according to 1. A film thickness measuring apparatus for carrying out a method for measuring a film thickness of a wet film in the measured object is
A light source that emits spectral light in a desired wavelength region;
The light from the light source is guided to the measured object side by the irradiation light guiding fiber, radiated from the emission part toward the measured object side, and the reflected light from the measured object is received by the detection light transmission fiber. A fiber probe to transmit,
An objective lens of a condensing optical system that vertically irradiates the irradiation light emitted from the emission portion of the fiber probe and condenses the light toward the light-transmitting wet film;
Reflected light reflected and interfered with each other on the wet film outermost surface and the hardened layer outermost surface of the object to be measured is transmitted by the detection light transmission fiber through the objective lens of the condensing optical system, and the transmitted detection light is transmitted. Spectroscopic means for spectroscopic analysis;
Spectral intensity detection means for detecting the spectral intensity of the detection light split by the spectroscopic means,
An arithmetic means for calculating and calculating the film thickness of the light-transmitting wet film in the object to be measured based on each wavelength that gives the minimum and maximum of the obtained spectral spectrum intensity and the refractive index of the light-transmitting wet film. The method for producing a photoconductive photoreceptor according to any one of claims 17 to 21, further comprising:   A photoconductive photoreceptor produced by the method for producing a photoconductive photoreceptor according to any one of claims 17 to 22.

Images