JP2009037197A - Protective agent application device, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective agent application device capable of preventing abnormal images while making good use of an advantage of a protective agent having paraffin as a main component. <P>SOLUTION: In the protective agent application unit to apply paraffin as the protective agent 21 to the surface of a photoreceptor 1, a ratio of values (X/Y) calculated by equations (1) and (2) is 2 or less when applying the protective agent 21 for 120 minutes, wherein the applied amount index of the protective agent 21 on the photoreceptor 1 is defined by the equation (1): X=(applied amount index of protective agent)=(Sb/Sa), and the coating ratio of the protective agent 21 to the photoreceptor 1 is defined by the equation (2): Y=(coating ratio of protective agent)=(A0-A)/A0×100(%). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention has a protective agent coating apparatus for applying a protective agent to a photosensitive body in order to protect the photosensitive body from mechanical stress such as frictional force with a cleaning blade and electrical stress due to charging, and the protective agent coating apparatus. The present invention relates to an image forming apparatus such as a process cartridge, a copier having the protective agent coating apparatus, a printer, a facsimile machine, and a plotter, and a multifunction machine including at least one of them.

In an image forming apparatus using an electrophotographic process, an image is formed by performing a charging process, an exposure process, a development process, and a transfer process on a photoreceptor. The discharge product generated in the charging process and remaining on the surface of the photoreceptor and the residual toner or toner component remaining on the surface of the photoreceptor after the transfer process are removed through a cleaning process.
As a generally used cleaning method, a rubber blade that is inexpensive, has a simple mechanism, and has excellent cleaning properties is used. However, since the rubber blade is used to remove the residue on the surface of the photoconductor by pressing it against the photoconductor, the stress caused by friction between the surface of the photoconductor and the cleaning blade is large. Wears the surface layer of the photoreceptor and shortens the life of the rubber blade and the organic photoreceptor.
In addition, the toner used for image formation in response to the demand for higher image quality has become a small particle size. In an image forming apparatus using a small particle size toner, the ratio of residual toner passing through the cleaning blade increases. In particular, the dimensional accuracy and assembly accuracy of the cleaning blade are insufficient, or the cleaning blade partially vibrates. In this case, the toner slips through the image, which prevents high-quality image formation.

Therefore, in order to extend the life of the organic photoreceptor and maintain high image quality over a long period of time, it is necessary to reduce deterioration of the member due to friction and improve cleaning properties.
In response to this requirement, a method of actually supplying a lubricant (protective agent) to the photoreceptor and forming a lubricant film with a cleaning blade is employed. Since the surface of the photoconductor is protected by the lubricant by applying the lubricant to the photoconductor, the photoconductor wear due to the friction between the cleaning blade and the photoconductor and the energy of the discharge caused by charging the photoconductor Degradation is reduced.
In addition, since the lubricity of the surface of the photoreceptor is increased by applying the lubricant, the phenomenon that the cleaning blade partially vibrates is reduced, and the amount of slip-through toner is reduced. However, such lubrication and protective properties are limited if the amount of lubricant applied is too small to provide sufficient effect on photoreceptor wear, photoreceptor deterioration due to AC charging, and toner slipping. It was necessary to keep it.

Regarding the evaluation of the amount of lubricant applied, when zinc stearate, which is generally used as a lubricant, is used, the amount of zinc stearate applied to the surface of the photoconductor is expressed as XPS (X-ray photoelectron) on the surface of the photoconductor. A method of evaluating by the ratio of zinc element to all elements detected by spectroscopy analysis has been used (see Patent Documents 1 to 4).
Since XPS detects all elements other than hydrogen on the surface of the sample electrode, analyzing the surface of the organic photoreceptor coated with zinc stearate using XPS, the organic photoreceptor has as the zinc stearate coverage increases. When the element ratio approaches the element ratio of zinc stearate and the coverage of zinc stearate reaches 100%, the element ratio theoretically matches the element ratio of zinc stearate, and the detected amount of zinc is saturated. End up.
That is, when zinc stearate (C ₃₆ H ₇₀ O ₄ Zn) covers the entire surface of the photoreceptor, the XPS is calculated based on the ratio of elements other than hydrogen in the molecule of zinc stearate (C ₃₆ H ₇₀ O ₄ Zn). Theoretically, the ratio of zinc element to the total elements detected by is 2.44%.

In recent years, in the charging process, so-called AC charging using a charging roller or the like for charging by superimposing an AC voltage on a DC voltage has been used. This AC charging has excellent performance such as high uniformity of the charging potential of the photoconductor, less generation of oxidizing gases such as ozone and NOx, and miniaturization of the apparatus, but the applied alternating current. Depending on the frequency of the voltage, hundreds to thousands of positive and negative discharges are repeated between the charging member and the photosensitive member per second, and the photosensitive member receives this large number of discharges to accelerate the deterioration of the surface layer.
In response to this deterioration, if a lubricant is applied to the photoconductor, the AC charging energy is first absorbed by the lubricant and hardly reaches the photoconductor, so that the photoconductor is protected.
Although the metal soap is decomposed by the energy of AC charging, it is not completely decomposed and lost, but a fatty acid having a low molecular weight is generated, the frictional force between the photoconductor and the cleaning blade is increased, and the fatty acid At the same time, the toner component easily adheres to the photosensitive film in the form of a film, so that the resolution of the image is liable to be lowered, and the photoconductor is worn, which tends to cause density unevenness.
Therefore, a large amount of metal soap is supplied onto the photoconductor so that the surface of the photoconductor can be immediately covered with metal soap even if fatty acids are generated. However, even if a large amount of metal soap is supplied onto the photoconductor, only a small portion actually adheres to the surface of the photoconductor, and most of the metal soap supplied onto the photoconductor is transferred together with the toner. In other words, the metal soap is depleted at an early stage, and the metal soap must be replaced with a new one before the life of the photosensitive member.

As a protective agent that replaces metal soap, for example, in Patent Document 5, a lubricant mainly composed of a higher alcohol having 20 to 70 carbon atoms is supplied. By using this lubricant, the higher alcohol stays as irregular particles at the tip of the blade nip portion, and has appropriate wettability to the surface of the photoconductor, so that the durability of the lubricating performance is expressed.
However, lubricants with higher alcohols tend to get wet on the surface of the photoconductor and can be expected to have an effect as a lubricant, but higher alcohol molecules adsorbed on the photoconductor, the adsorption occupation area per molecule tends to be widened, Since the density of molecules adsorbed per unit area of the photoreceptor (adsorbed molecule weight per unit area) is small, it is difficult to protect the photoreceptor from the electrical stress due to AC charging described above.
Further, in Patent Document 6, since powder of a specific alkylenebisalkylamide compound is used as a lubricity component, powder fine particles exist at the interface where the cleaning blade and the photosensitive member are pressed, so that smooth lubrication is possible. The action can be maintained over a long period of time.
However, a lubricant having a nitrogen atom in the molecule has an ion dissociation property similar to a nitrogen oxide or an ammonium-containing compound as a decomposition product when the lubricant itself is subjected to the above-described electrical stress due to AC charging. A compound is formed and taken into the lubricating layer, and the lubricating layer may have a low resistance under high humidity, resulting in image blurring.

On the other hand, the paraffin-based protective agent protects the photoconductor from electrical stress due to AC charging, can reduce the frictional force between the photoconductor and the cleaning blade, and has extremely good cleaning properties for waste toner. It turns out to be good.
In particular, a protective agent containing paraffin as a main component is very preferable because even if it is oxidized by stress due to AC charging, the production of fatty acid is small and the change in frictional force between the photosensitive member and the cleaning blade is very small.

JP 2005-17469 A JP 2005-249901 A JP-A-2005-004051 JP 2004-198662 A JP 2005-274737 A JP 2002-97483 A

However, when image formation is repeated using a protective agent mainly composed of paraffin, streaky abnormal images that may be caused by wear of the photoreceptor and the cleaning blade may occur.
In particular, the probability of occurrence of an abnormal image may vary greatly depending on the lot for manufacturing the protective agent coating apparatus.
A detailed investigation of where the abnormal image occurred and where it did not occur revealed that the photoconductor film thickness was small at the location where the streaky abnormal image occurred and where no abnormal image occurred. It was found that the toner component was attached and a large amount of the toner component was attached, but it was not known why this phenomenon occurred.
As described above, paraffin is effective as a protective agent to replace metal soap. However, when a protective agent having a simple structure not containing metal such as paraffin is used, the metal is not used in XPS analysis or XRF analysis. Since it was not detected, it was difficult to evaluate the amount of protective agent applied on the photoreceptor. In the case of a protective agent containing a metal such as a metal soap, the coating amount can be traced from a metal element by ICP (Inductively Coupled Plasma) emission spectroscopic analysis as a method for determining the coating amount, but it contains a metal such as paraffin. When the protective agent not used was used, the coating amount could not be evaluated by ICP emission spectroscopic analysis.

  In view of the above problems, the present invention provides a protective agent coating apparatus capable of preventing abnormal images while taking advantage of a protective agent mainly composed of paraffin, a process cartridge having the protective agent coating apparatus, and an image forming apparatus. The purpose is to provide.

First, how the present invention was established will be described.
In order to investigate the cause of the occurrence of an abnormal image, the present inventors consider that the amount of the protective agent is different between the place where the abnormal image occurs and the place where the abnormal image does not occur, and observe the surface using the SEM. went.
As a result of surface observation, it was possible to observe the appearance of the protective agent adhering to the photoconductor, but the amount of the protective agent could not be estimated from SEM observation, I didn't understand.
Next, the present inventors considered that the generation mechanism of the abnormal image differs depending on the image to be imaged, and observed the location where the abnormal image is generated in more detail by SEM. As a result, the image area of the image to be imaged When the amount of toner is small, the toner component often adheres to the photoreceptor and the resolution of the image is often lowered. When the image area of the image to be formed is large, the photoreceptor is partially worn and an abnormal image is likely to occur. I understood.
As described above, the method of generating an abnormal image differs depending on the image to be formed. Therefore, the image is not formed and only the protective agent is applied on the photoconductor, that is, depending on the protective agent application capability of the protective agent application device. Considering that an abnormal image may or may not appear, an application amount of the protective agent on the photoconductor is expressed using an index, and an attempt was made to determine an appropriate application amount of the protective agent using the index.

As described above, when a protective agent containing no metal such as paraffin is used as the protective agent, it is difficult to estimate the amount of the protective agent applied on the photoreceptor by a conventional method.
Therefore, an attempt was made to use the FT-IR ATR method, which is used for analysis of XPS and organic substances, as a method for analyzing a protective agent containing no metal.
First, in the analysis using XPS, it was necessary to devise since the protective agent contains no metal element. Therefore, in order to obtain an index that can grasp the amount of the protective agent applied on the photoconductor even when a protective agent containing no metal such as paraffin is used as the protective agent, the components contained in the protective agent However, it was investigated whether the amount of the protective agent could be grasped by tracing the components contained only in the photoreceptor.
That is, if the value of the index representing the component contained only in the photoconductor is decreased by applying the protective agent, it means that the protective agent coats the photoconductor.

As a result of investigating an analysis method suitable for tracing components contained only in the photoreceptor, a photoreceptor containing a polycarbonate resin without a protective agent is detected by XPS analysis without applying the protective agent. Regarding the C1s spectrum, when the waveform separation of different bonding states of carbon is performed, a peak having a peak top in the range of 290.3 to 294 eV can be separated, but the polycarbonate resin after applying a sufficient amount of protective agent is included. When XPS analysis is performed on the photoconductor, the peak existing in the range of 290.3 to 294 eV disappears, or the total area of the peak having the peak top in the range of 290.3 to 294 eV with respect to the area of the entire C1s spectrum However, the present inventors have found that the existing ratio is much smaller than that in the case of XPS analysis of the photoreceptor before applying the protective agent.
Here, the peak indicates a curve represented by a Gaussian function or a Lorentz function, and the peak top indicates a vertex of the curve. As a function, not only a Gaussian function and a Lorentz function but also a function suitable for waveform separation such as a composite function of a Gaussian function and a Lorentz function is used as appropriate.

Subsequently, it was examined whether or not a good state of the protective agent on the photoreceptor after applying the protective agent using the protective agent coating apparatus could be defined with this coverage, and the photoreceptor coverage ((A0-A) / A0 ×). 100) (%) within the preferable range was found to easily maintain high-quality image output.
The photoreceptor of the present invention contains polycarbonate, and peak 1 having a peak top in the range of 290.3 to 294 eV in the C1s spectrum obtained by XPS analysis is a combination of carbonate bonds in the polycarbonate resin and the photoreceptor. The peak appearing due to the π-π * transition of the benzene ring in the CTM (charge transport material) or polycarbonate resin, but the peak having a peak top in the range of 290.3 to 294 eV is reduced or eliminated. By applying a protective agent such as paraffin to the photosensitive member, the surface of the photosensitive member is covered with the protective agent, and the exposed portion of the photosensitive member is reduced.

Therefore, it is possible to determine the degree of exposure of the photosensitive member based on the degree of decrease in the area ratio of the sum of the areas of all peaks having a peak top in the range of 290.3 to 294 eV (total area) to the area of the entire C1s spectrum.
When such an evaluation method is used, the degree of exposure of the photosensitive member can be determined even if the protective agent does not contain a metal, and thus it can be said that the evaluation method is not more restricted by the type of the protective agent. .
When determining the application state of the protective agent, the detection depth of the analytical instrument is very important. That is, if the analysis depth is too deep, if the protective agent is very thinly placed on the surface of the photoconductor, only the signal of the photoconductor may be detected strongly. As described above, XPS detects only the depth of 5 to 8 nm on the extreme surface, and is therefore very preferable as a method for analyzing the state of the protective agent thinly applied on the photoreceptor.

Next, it was examined whether the amount of the protective agent on the photoconductor can be defined by an index using the FT-IR ATR method used for the analysis of organic matter.
Here, the IR spectrum obtained by FT-IR looks at how the intensity distribution with respect to the wave number (wavelength) of light possessed by the infrared light source changes depending on the specimen sample, and is usually the reciprocal of the wavelength. The wave number (unit: cm-1) is taken as a horizontal axis, and the vertical axis shows transmittance (T) and absorbance (A) and is drawn as a curve. “Cm-1” means cm ⁻¹ .
The transmittance is the ratio of the energy transmitted through the sample to the energy incident on the sample, and the absorbance is a common logarithm of the reciprocal of the transmittance. It is well known that the absorbance and the sample concentration are in a proportional relationship (Lambert-Beer's law), and when performing a quantitative calculation, the peak intensity of the absorbance spectrum is generally used.
The peak intensity of the IR spectrum is preferably not a transmittance but an absorbance with good quantitativeness.
Devices for measuring IR spectra are broadly divided into dispersive infrared spectrophotometers and Fourier transform infrared spectrophotometers, and because of their high time efficiency, light usage rate, wave number resolution, and wave number accuracy, Fourier transform red Outer spectrophotometers (FT-IR) are the current mainstream.

As a measurement method, there are various measurement accessories in addition to the normal transmission method, and the measurement method can be selected according to the form of the sample and information to be known. Among various measurement accessories, the ATR method can measure an IR spectrum with almost no sample processing, and has recently become quite popular as a measurement accessory for FT-IR.
The ATR method is a method for measuring an infrared absorption spectrum, which uses total reflection. An ATR prism having a high refractive index is closely attached to a sample, and the sample is irradiated with infrared light through the ATR prism. The light emitted from the ATR prism is spectrally analyzed.
When infrared light is incident on the prism at a certain angle or more due to the refractive index relationship between the ATR prism and the sample, the infrared light does not exit the ATR prism and causes total reflection at the contact surface between the ATR prism and the sample. However, at that time, the infrared light oozes to the sample side by a short distance, so that if the sample absorbs the infrared light, the reflected light attenuates and the absorption spectrum of the sample can be obtained.
Since the ATR method can measure the absorption spectrum of a very thin sample portion in contact with the ATR prism, it has the advantage that even a thick sample or a sample with low permeability can be measured if it can be brought into close contact with the ATR prism. I have.
In addition, when the ATR method is used, the functional group is known from the wave number at which infrared light absorption occurs, so the ATR method is often used for qualitative analysis, but the peak intensity of the absorption spectrum changes depending on the pressure with which the sample is pressed. It was not basically used for quantitative analysis.

However, the present inventors consider that it is possible to estimate the coating amount of the protective agent on the photosensitive member by using the ATR method, and therefore various ATR measurements are performed on the photosensitive member coated with the protective agent. The spectra were compared and analyzed.
As a result, in the ATR method, the penetration depth of infrared light changes depending on the crystal used and the incident angle condition. Therefore, the spectrum obtained even if the same sample is measured is different, and the photoconductor depends on the crystal used and the incident angle condition. Only the peak derived from the photocatalyst was detected, only the peak of only the protective agent was detected, and both the peak derived from the photoconductor and the peak derived from the protective agent were detected.
Applying the protective agent on the photoconductor from the spectrum obtained under various conditions where both the crystal used and the incident angle are finely changed to detect both the photoconductor-derived peak and the protective agent-derived peak. An intensive study was conducted to determine whether the amount could be evaluated.

Here, in the ATR method, since the intensity ratio changes depending on the pressure with which the sample is pressed, the intensity of the spectrum cannot be followed directly. Therefore, when the sample is set in measurement, if the gap between the jig for fixing the sample and the crystal can be kept constant, or if the pressing pressure is constant, the IR spectrum under a certain condition is It was considered that the sample was set, and at the time of setting the sample, the gap between the jig for pressing the sample and the crystal could be kept constant, and the sample with the coating time varied using a protective agent coating apparatus was measured.
As a result, for each spectrum obtained, the peaks in the spectrum were assigned and the ratio of the area of the peak derived from the protective agent to the area of the peak derived from the photoconductor was taken. It has been found that the ratio of increases gradually.
Next, the ratio of the area of the peak derived from the protective agent to the area of the peak derived from the photoconductor was further attempted to take a ratio with the coverage calculated by the XPS analysis described above.
As a result, it can be seen that high-quality image formation can be maintained by setting the ratio of the area ratio calculated from the ATR method and the ratio of the coverage calculated from the XPS method to a preferable range, and the present invention has been realized. It was.

Specifically, in the invention according to claim 1,
A protective agent application device for applying a protective agent mainly composed of paraffin on the surface of a photoreceptor,
When the index of the amount of the protective agent on the photoconductor is expressed by the following formula (1) and the coverage of the protective agent on the photoconductor is expressed by the following formula (2), when the protective agent is applied for 120 minutes, The protective agent coating apparatus, wherein a ratio (X / Y) of values calculated from the formulas (1) and (2) is 0.020 or less.
X = (index of the amount of protective agent attached) = (Sb / Sa) (1)
Y = (coverage of protective agent) = (A0−A) / A0 × 100 (%) (2)
Here, about Formula (1),
In the ATR (Attenuated Total Reflection) method of the infrared absorption spectrum method, the IR spectrum obtained by measurement under the conditions of Ge as the ATR prism and 45 ° as the incident angle of infrared light, When the spectrum is IR spectrum A (absorbance spectrum) and the IR spectrum of the protective agent alone is IR spectrum B (absorbance spectrum),
Sa does not exist in the IR spectrum B in the IR spectrum (IR spectrum C (absorbance spectrum)) of the photoconductor after 120 minutes of application of the protective agent by the protective agent coating apparatus, and exists in the IR spectrum A 1770 cm −. 1 shows the peak area (Sa) of the peak (peak a) seen in FIG.
Sb is not present in the IR spectrum A and is present in the IR spectrum B in the IR spectrum (IR spectrum C (absorbance spectrum)) of the photoreceptor after 120 minutes of application of the protective agent by the protective agent coating apparatus. 1 shows the peak area (Sb) of the peak (peak b) seen in FIG.
Moreover, about Formula (2),
A0 relates to the C1s spectrum initially obtained by XPS analysis on the surface of the photoreceptor, and the peak obtained by separating the waveform resulting from different bonding states of carbon according to the binding energy is in the range of 290.3 to 294 eV. The ratio of the sum of the areas of peaks having peak tops (total area) to the area of the entire C1s spectrum is shown,
A shows a C1s spectrum obtained by XPS analysis of the surface of the photoconductor after applying the protective agent on the photoconductor for 120 minutes, and shows a waveform generated from different bonding states of carbon according to the binding energy. About the peak obtained by isolate | separating, the ratio with respect to the area of the whole C1s spectrum after the said protective agent application | coating of the sum (total area) of the peak area which has a peak top in the range of 290.3-294 eV is shown.

In the protective agent coating apparatus of the present invention, when the protective agent is applied for 120 minutes, the ratio (X / Y) of the values calculated from the formulas (1) and (2) is 0.020 or less, preferably 0.016 or less, more preferably 0.014 or less.
When the protective agent is applied for 120 minutes and the ratio (X / Y) of the values calculated from the equations (1) and (2) is 0.020 or more, the amount of the protective agent attached is too large. This is not preferable because a blurred image tends to occur.
Further, when the protective agent is applied for 120 minutes, the ratio (X / Y) of the values calculated from the formula (1) and the formula (2) is preferably 0.0002 or more. When the ratio (X / Y) of the values calculated from the formulas (1) and (2) is 0.0002 or less, the protective effect of the photosensitive member cannot be sufficiently maintained, which is not preferable.

When a protective agent is applied to the photoreceptor, the amount of the protective agent attached increases as the application time increases. However, the adhesion amount of the protective agent does not increase indefinitely, and is saturated to a certain amount by the coating device. Since 120 minutes is sufficient for the protective agent to become saturated, (X / Y) is calculated from the photoconductor after 120 minutes of application of the protective agent.
Here, the infrared light does not reflect at the sample interface, but enters the sample side by a certain depth and then totally reflects, but the penetration depth of the infrared light irradiates the sample with infrared light. At this time, the infrared light intensity is defined as a distance that is 1 / e of the intensity on the sample surface. The higher the refractive index of the ATR crystal, the shorter the measurement wavelength, the smaller the depth of penetration, and information closer to the surface is reflected in the spectrum.

In the present invention, the ATR method is used for analysis of the protective agent on the photosensitive member, and Ge having a large refractive index and capable of obtaining information closer to the surface is used as the ATR prism. In addition, the incident angle of infrared light to the sample is 45 °.
In the evaluation of the coating apparatus of the present invention, an index with higher accuracy can be obtained by setting the incident angle of infrared light to 45 °. A combination of these ATR prisms and infrared light incident angles can express a preferable state as the coating amount of the protective agent on the photoreceptor.
The peak b (see FIG. 7) is a peak derived from a methylene group, and is detected as a peak having a sufficient intensity, and thus is preferable as an index for estimating the protective agent on the photoreceptor. In FIG. 7, “new lubricant” means a protective agent mainly composed of paraffin according to the present invention.
Peak a (see FIG. 7) is a peak derived from polycarbonate contained in the photoconductor, and is detected as a peak of sufficient strength in the photoconductor before applying the protective agent containing polycarbonate. It is preferable as an index for estimating the protective agent.
Moreover, since the detected wavelengths are close to each other, the peak a and the peak b are preferable because the sensitivity of the coating amount calculation index Sa / Sb is improved. In the present invention, the peak area is calculated using an absorbance spectrum with good quantitativeness.

In the FT-IR analysis, as a method of estimating the coating amount of the protective agent on the photoconductor, it may be possible to simply follow the area of the peak derived from the protective agent, but in the ATR method, depending on the pressure with which the sample is pressed. Since the peak area (intensity) changes, it is not preferable to directly follow the spectrum area (intensity).
As a coating amount index, it is preferable to obtain a stable index by using a ratio of a peak derived from the photoconductor to a peak derived from the protective agent.
Regarding the peak a in the IR spectrum C, the peak a is not present in the IR spectrum B but is present in the IR spectrum A.
In the state shown in FIG. 8, a state where no peak is detected in the IR spectrum B is shown at the wave number where the peak a is detected.
For example, as shown in FIG. 9, the peak M is a peak existing in the IR spectrum B, and is not suitable as a peak for calculating the coating amount index.
The peak a is more preferably a peak that does not overlap with the peak present in the IR spectrum B. In other words, it is preferable that the peak a exists in the IR spectrum B with the peak a as shown in FIG.

As shown in FIG. 8, when the peak a overlaps with the peak existing in the IR spectrum B, it is necessary to take a difference spectrum between the IR spectrum C and the IR spectrum B. By using the difference spectrum, an index (area ratio (Sb / Sa)) that is not affected by the peak existing in the IR spectrum B can be obtained.
However, even when the peak a overlaps with the peak existing in the IR spectrum B, as shown in FIG. 8, when the area of the peak a is sufficiently larger than the area of the peak overlapping the peak a, the IR spectrum The step of subtracting the IR spectrum B from C may be omitted.
By excluding this subtracting process, the number of processes is reduced by one, so the calculation of the index (area ratio (Sb / Sa)) becomes easier and the accuracy is improved.

Further, with respect to the peak b in the IR spectrum C, the peak b does not exist in the IR spectrum A but exists in the IR spectrum B.
In the state as shown in FIG. 11, the state in which no peak is detected in the IR spectrum A is shown at the wave number where the peak b is detected.
For example, as shown in FIG. 12, the peak N in the IR spectrum B is a peak existing in the IR spectrum A and is not suitable as a peak for calculating the coating amount index.
The peak b is more preferably a peak that does not overlap with the peak present in the IR spectrum A. That is, it is preferable that the peak a existing in the IR spectrum B does not overlap the peak a peak of the peak a with the peak a shown in FIG.
As shown in FIG. 11, when the peak a overlaps with the peak existing in the IR spectrum B, it is necessary to take a difference spectrum between the IR spectrum C and the IR spectrum A. By using the difference spectrum, an index (area ratio (Sb / Sa)) that is not affected by the peak existing in the IR spectrum A can be obtained.
However, even when the peak b overlaps with the peak existing in the IR spectrum A, as shown in FIG. 11, when the area of the peak b is sufficiently larger than the area of the peak overlapping the peak b, the IR spectrum The step of subtracting the IR spectrum A from C may be omitted.
By excluding this subtracting process, the number of processes is reduced by one, so the calculation of the index (area ratio (Sb / Sa)) becomes easier and the accuracy is improved.

According to a second aspect of the present invention, in the protective agent coating apparatus according to the first aspect, the coverage Y of the protective agent is 70% or more.
The coverage Y of the protective agent in the protective agent coating apparatus of the present invention is 70% or more, preferably 75% or more, and more preferably 80% or more when the protective agent is applied for 120 minutes.
When the protective agent coverage Y when the protective agent is applied for 120 minutes is less than 70%, the speed at which the protective agent is coated on the photosensitive member is too slow. The photosensitive member is not sufficiently protected from the above, and the frictional force between the photosensitive member and the cleaning blade is partially increased.
Further, the photoconductor whose coverage is measured by the above method using XPS is destroyed and cannot be used. However, it may be considered that the protective agent coating apparatuses of the production lot under the same conditions are equivalent.
However, even under the same conditions, the coverage changes depending on the production lot of the material used, and when an image is formed, an abnormal image is often generated. It is preferable to confirm whether or not the manufactured protective agent coating apparatus can maintain the coverage of the present invention.

4 and 5 are diagrams showing the intensity distribution of the binding energy by XPS analysis on the surface of the photoreceptor before and after application of the protective agent. FIG. 4 is a view showing before the protective agent is applied, and FIG. 5 is a view showing after the protective agent is applied. 5A shows an example in which the coverage is 74%, and FIG. 5B shows an example in which the coverage is 98%.
Here, with reference to FIGS. 4 and 5 as model diagrams, the above-described method of obtaining A0 and A will be described. First, how to obtain A0 will be described based on the C1s spectrum before applying the protective agent shown in FIG. The C1s spectrum is a spectrum ranging from 281 to 296 eV in FIG. As a method for calculating the area of the entire C1s spectrum, there are a method in which all the peaks included in the spectrum are separated, each area is obtained and the sum of the areas is obtained, and a method in which the C1s spectrum is calculated as a block area. Can be mentioned. It is more preferable to calculate the C1s spectrum as a block area because there is no need for peak separation and accuracy is high. The C1s spectrum entire area before the protective agent applied calculated in any manner, hereinafter referred to as Y _0.

On the other hand, the peak detected in the range of 290.3 to 294 eV (peak top) used for the calculation of A0 is a peak derived from a carbonate bond (a portion adjacent to the right side of the hatched portion in the same figure), and The peaks resulting from the π-π * transition (indicated by the hatched portion in the figure) are separated, and the peaks resulting from the π-π * transition are present by overlapping a plurality of peaks. Therefore, the total area of peaks detected in the range of 290.3 to 294 eV (peak top) is obtained by separating each peak, obtaining the area of each peak, and taking the sum of those areas, (W ₀ : before application of protective agent) is required. As shown in the figure, the total area (W ₀ ) is when the peak seen in the range of 290.3 to 294 eV (peak top) is less than 290.3 eV (peak top) and does not overlap with the bottom of the peak of 294 eV or more Only, the waveform seen in the range of 290.3 to 294 eV (peak top) can be calculated as a lump area without waveform separation.
As described above, if the area (Y ₀ ) and the area (W ₀ ) can be calculated, A can be calculated by the following equation.
A0 = W ₀ / Y ₀ × 100
In the example of FIG. 4, A0 = 8.7%.

Similarly, how to obtain A will be described based on the C1s spectrum after applying the protective agent shown in FIG. As described above, the C1s spectrum indicates a spectrum ranging from 281 to 296 eV in the figure. The method for calculating the area of the entire C1s spectrum is exactly the same as the method for obtaining Y ₀ , separating all peaks included in the spectrum, obtaining each area, and obtaining the sum of those areas, and the entire C1s spectrum. Can be calculated as the area of a lump, and it is more preferable to calculate the entire C1s spectrum as the area of a lump because there is no need for peak separation and accuracy is high. The C1s spectrum entire area after the protective agent applied calculated in any manner is referred to as Y _1.

The calculation method of A is the same as the calculation method of A0. That is, the peak detected in the range of 290.3 to 294 eV (peak top) is a peak derived from a carbonate bond (a portion adjacent to the right side of the hatched portion in FIG. 5A), and π−π, as shown in FIG. * It is separated into peaks caused by transitions (hatched portion in FIG. 5A), and the peaks caused by this π-π * transition are present by overlapping a plurality of peaks. Therefore, the total area of peaks detected in the range of 290.3 to 294 eV (peak top) is obtained by separating each peak, obtaining the area of each peak, and taking the sum of those areas, (W: after application of protective agent) is required. As shown in the figure, the total area (W) is only when the peak in the range of 290.3 to 294 eV (peak top) does not overlap with the peak of 290.3 eV (peak top) or lower and the peak of 294 eV or higher. , 290.3 to 294 eV (peak top), waveforms can be calculated as a single area without waveform separation.
As described above, if the area (Y ₁ ) and the area (W) can be calculated, A can be calculated by the following equation.
A = W / Y ₁ × 100
Using A and A0 obtained as described above, the coverage Y is ((A0−A) / A0 × 100) (%)
It can be calculated by the following formula.
In the example of FIG. 5A, A = 2.3%, and in the example of FIG. 5B, A = 0.2%.

In invention of Claim 3, in the protective agent coating device of Claim 1 or 2,
The protective agent bar made of the protective agent is scraped off with a brush, and the brush electrostatically flocks 50,000 to 600,000 monofilaments having a diameter of 28 to 42 μm per square inch on a metal core. The paraffin is supplied to the photoconductor by pressing the brush against the photoconductor, and the blade is pressed against the photoconductor to apply the protective agent on the photoconductor. It is fixed.

According to a fourth aspect of the present invention, in the process cartridge, at least the photosensitive member and the protective agent coating apparatus according to any one of the first to third aspects are integrally provided.
According to a fifth aspect of the present invention, the image forming apparatus includes the protective agent coating apparatus according to any one of the first to third aspects.

  According to the present invention, the protective agent mainly composed of paraffin is used to protect the photoreceptor against electrical stress due to AC charging, reduce the frictional force between the photoreceptor and the cleaning blade, and clean the waste toner. Abnormal images can be prevented.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 7.
FIG. 1 is a schematic configuration diagram of a process cartridge 12 integrally including a protective agent coating apparatus 20 according to the present embodiment.
The process cartridge 12 includes a photosensitive drum (hereinafter also simply referred to as “photosensitive member”) 1, a protective agent coating device 20, a charging roller 3, a developing device 5, and the like that are disposed to face the photosensitive drum 1. Is housed in. The protective agent coating device 20 includes a protective agent supply unit 2, a cleaning mechanism 4 positioned upstream of the protective agent supply unit 2 in the photosensitive drum rotation direction, and a protective layer forming mechanism 24 positioned downstream of the photosensitive drum rotation direction. It is composed of
The developing device 5 includes a developing roller 51, conveying screws 52 and 53 that circulate the developer while stirring and conveying, a preset case 54 that accommodates toner, and the like.
In the present embodiment, the protective agent coating apparatus 20 includes the cleaning mechanism 4, but the present invention is not limited to this.

The protective agent supply unit 2 includes a protective agent bar 21, a protective agent supply member 22, a pressing force application mechanism (here, a spring) 23, a protective agent bar support guide 25 that supports the protective agent bar 21 so as not to swing back and forth, and the like. It is composed of
The protective agent bar 21 used in the present invention is produced by a melt molding method in which a protective agent is melted and then charged into a mold and cooled to prepare, or a compression molding method in which a protective agent powder is compressed to prepare.
The cleaning mechanism 4 includes a cleaning member 41, a cleaning pressing mechanism 42 that urges the cleaning member 41 in the clockwise direction, and the like.
The cleaning member 41 is provided with a blade support 41b rotatably provided around a shaft 41c, and one end (an end on the opposite side of the photosensitive drum) supported by the blade support 41b. The cleaning blade 41a is in contact with the surface in the counter direction.

  The protective layer forming mechanism 24 is provided with a blade support 24b rotatably provided about a shaft 24c, and one end (an end opposite to the photosensitive drum side) supported by the blade support 24b. A blade 24a that abuts the surface of the drum 1 in the trailing direction, a spring 24d as a pressing means that urges the blade support 24b counterclockwise and presses the blade 24a against the surface of the photosensitive drum 1 and the like. is doing.

The protective agent bar 21 is in contact with, for example, a brush-like protective agent supply member 22 by the pressing force from the pressing force applying mechanism 23. The protective agent supply member 22 rotates and rubs with the photosensitive member 1 with a linear velocity difference. At this time, the protective agent held on the surface of the protective agent supply member 22 is supplied to the surface of the photosensitive member.
Since the protective agent supplied to the surface of the photoconductor may not be a sufficient protective layer upon supply depending on the selection of the type of substance, in order to form a more uniform protective layer, for example, a protective layer having a blade-like member The layer is thinned by the forming mechanism 24 to become a photosensitive member protective layer.

  The protective agent deteriorated by exposure to electrical stress is removed by the cleaning mechanism 4 together with other components such as toner remaining on the photoreceptor. The cleaning mechanism 4 may also be used as the protective layer forming mechanism 24, but the function of removing the photoreceptor surface residue and the function of forming the protective layer may differ in the rubbing state of an appropriate member. Therefore, the functions are preferably separated and provided on the upstream side in the rotation direction of the photosensitive drum 1 from the protective agent supply unit 2 as shown in FIG.

The photosensitive drum 1 has a surface on which partially deteriorated protective agent, toner component, and the like remain after the transfer process, but the surface residue is cleaned and cleaned by the cleaning member 41.
In FIG. 1, the cleaning member 41 is abutted at an angle similar to a so-called counter type (leading type).

The protective agent is supplied from the protective agent supply member 22 to the surface of the photosensitive drum 1 from which the residual toner and the deteriorated protective agent have been removed by the cleaning mechanism 4, and the protective layer forming mechanism 24 protects the film. A layer is formed.
At this time, the protective agent according to the present embodiment has a better adsorptivity to the portion of the surface of the photosensitive drum 1 that is highly hydrophilic due to electrical stress. Even if a stress is applied and the surface of the photoconductor begins to partially deteriorate, the deterioration of the photoconductor itself can be prevented by the adsorption of the protective agent.
The photosensitive drum 1 having a protective layer formed on the surface by the protective agent coating device 20 is charged, and an electrostatic ray image is formed by exposure L such as a laser. This latent image is visualized as a toner image by the developing device 5 and transferred to an intermediate transfer belt 105 as an intermediate transfer medium by a transfer roller 6 as a transfer device outside the process cartridge 12. In the case of the direct transfer method, the transfer medium is a sheet-like recording medium.

The material of the blade 24a used in the protective layer forming mechanism 24 is not particularly limited. For example, elastic materials such as urethane rubber, hydrin rubber, silicone rubber, and fluorine rubber, which are generally known as cleaning blade materials, may be used alone or in a blend. Can be used.
Further, these rubber blades may be coated or impregnated with a low friction coefficient material at the contact portion with the photoreceptor. Moreover, in order to adjust the hardness of an elastic body, you may disperse | fill the filler represented by another organic filler and an inorganic filler.

These blades are fixed to the blade support 24b by an arbitrary method such as adhesion or fusion so that the tip portion can be pressed against the surface of the photoreceptor. The blade thickness cannot be uniquely defined in consideration of the force applied by pressing, but can be preferably used if it is about 0.5 to 5 mm, and more preferably about 1 to 3 mm.
Also, the length of the cleaning blade that protrudes from the blade support and can be deflected, the so-called free length is also applied by pressing in the same manner, but it cannot be uniquely defined in terms of the force, but generally 1 to If it is about 15 mm, it can be preferably used, and if it is about 2-10 mm, it can be used more preferably.

As another configuration of the blade member for forming the protective layer, the surface of the elastic metal blade such as a spring plate may be coated with a layer of resin, rubber, elastomer or the like via a coupling agent or a primer component, if necessary. It may be formed by a method, and if necessary, heat curing or the like may be performed, and if necessary, surface polishing or the like may be performed.
The thickness of the elastic metal blade is preferably about 0.05 to 3 mm, and more preferably about 0.1 to 1 mm.
Moreover, in an elastic metal blade, in order to suppress the twist of a blade, you may perform processes, such as a bending process, in the direction substantially parallel to a spindle after attachment.
As a material for forming the surface layer, fluorine resin such as PFA, PTFE, FEP, PVdF, silicone elastomer such as fluorine rubber, methylphenyl silicone elastomer, and the like can be used together with a filler, if necessary. It is not limited to this.

Further, the force that presses the photoreceptor with the protective layer forming mechanism 24 is sufficient to spread the protective agent and become a protective layer or a protective film, and the linear pressure is 5 gf / cm or more and 80 gf / cm or less. Is preferably 10 gf / cm or more and 60 gf / cm or less.
A brush-like member is preferably used as the protective agent supply member 22. In this case, the brush fiber is preferably flexible in order to suppress mechanical stress on the surface of the photoreceptor.
As a specific material of the flexible brush fiber, one or more kinds can be selected and used from generally known materials. Specifically, polyolefin resins (for example, polyethylene, polypropylene); polyvinyl and polyvinylidene resins (for example, polystyrene, acrylic resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and Polyvinyl chloride); vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; styrene-butadiene resin; fluororesin (eg, polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene); Polyester; Nylon; Acrylic; Rayon; Polyurethane; Polycarbonate; Phenol resin; Amino resin (eg urea-formaldehyde resin, melamine) Fat, benzoguanamine resins, urea resins, polyamide resins); Among such, may be a resin having flexibility.
Also, in order to adjust the degree of bending, diene rubber, styrene-butadiene rubber (SBR), ethylene propylene rubber, isoprene rubber, nitrile rubber, urethane rubber, silicone rubber, hydrin rubber, norbornene rubber, etc. are used in combination. Also good.

The support body of the protective agent supply member 22 includes a fixed mold and a rotatable roll. As a roll-shaped supply member, for example, there is a roll brush obtained by winding a tape made of brush fibers in a pile ground around a metal core bar in a spiral shape. The brush fiber has a fiber diameter of about 10 to 500 μm, the length of the brush fiber is 1 to 15 mm, the brush density is 10,000 to 300,000 per square inch (1.5 × 107 to 4.5 × 108 per square meter) ) Is preferably used.
The protective agent supply member 22 is preferably made of a material having a very high brush density in terms of supply uniformity and stability, and one fiber is made from several to several hundreds of fine fibers. Is also preferable. For example, bundling 50 fine fibers of 6.7 decitex (6 denier), such as 333 decitex = 6.7 decitex × 50 filament (300 denier = 6 denier × 50 filament), and implanting as one fiber Is also possible.

Among these protective agent supply members, a brush made of a single fiber having a thickness of 28 to 43 μm, preferably 30 to 40 μm is most preferable because of its high supply efficiency of the protective agent. Since fibers are often produced by twisting, the diameter of the fibers is not uniform, and therefore, denier and decitex units have been used.
However, in the case of a single fiber, the fiber diameter is constant, so that it is preferable to define the fiber diameter in order to define the protective agent supply member.
When the diameter of the single fiber is smaller than 28 μm, the efficiency of supplying the protective agent is lowered, and when the diameter of the single fiber exceeds 43 μm, the rigidity of the single fiber becomes too high and the photoreceptor is easily damaged.
Moreover, it is preferable that the 28-43 micrometer single fiber is planted as perpendicularly as possible with respect to a metal core, and when manufacturing a brush, it is manufactured by what is called electrostatic flocking using static electricity. Is preferred. The electrostatic flocking is performed by applying an adhesive on the core metal of the brush and charging the core metal, thereby flying single fibers of 28 to 43 μm by electrostatic electric force, and flocking the adhesive on the core metal. This is a method of curing the adhesive. Thus, the brush which planted 50,000 to 600,000 per square inch by electrostatic flocking can be used conveniently.

Moreover, you may provide a coating layer in the brush surface for the purpose of stabilizing the surface shape of a brush, environmental stability, etc. as needed. As a component constituting the coating layer, it is preferable to use a coating layer component that can be deformed according to the bending of the brush fiber, and these are not limited as long as the material can maintain flexibility. Can be used without any problems.
For example, polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, chlorosulfonated polyethylene; polystyrene, acrylic (for example, polymethyl methacrylate), polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether Polyvinyl chloride and polyvinylidene resins such as polybiliketones; vinyl chloride-vinyl acetate copolymers; silicone resins composed of organosiloxane bonds or modified products thereof (for example, modified products using alkyd resins, polyester resins, epoxy resins, polyurethanes, etc.); Fluorine resins such as fluoroalkyl ether, polyfluorovinyl, polyfluorovinylidene, polychlorotrifluoroethylene; Polyamide, polyesters, polyurethanes, polycarbonates, urea - amino resins such as formaldehyde resins; and epoxy resins, such as their composite resins.

As the charging means used in the process cartridge 12 of the present invention, the charging roller 3 shown in FIG. 1 is used in addition to the corona charging and the solatron charging. A charging roller is preferably used.
The charging roller charges the photosensitive member by applying a voltage between the charging roller and the photosensitive member in contact with the photosensitive member or in a state of being close to 20 to 100 μm. The voltage applied between the charging roller and the photoconductor may be a DC voltage (DC charging), or an AC voltage may be superimposed on the DC voltage (AC charging).
The charging roller is preferably composed of a polymer layer and a surface layer on a conductive support.
The conductive support functions as an electrode and a support member of the charging roller 13, and includes, for example, a metal or alloy such as aluminum, copper alloy, stainless steel, iron subjected to a plating process with chromium, nickel, or a conductive agent. It is made of a conductive material such as an added resin.

The polymer layer is preferably a conductive layer having a resistance of 10 ⁶ to 10 ⁹ Ωcm, and a polymer material mixed with a conductive agent to adjust the resistance is used. As the polymer of the polymer layer of the charging roller used in the image forming apparatus of the present invention, polyester-based, olefin-based thermoplastic elastomer, polystyrene, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene Styrenic thermoplastic resins such as acrylonitrile copolymer, isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, urethane rubber, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide Copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene Emissions copolymer rubber, natural rubber, and blends the rubber material. Among the rubber materials, silicone rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, acrylonitrile-butadiene copolymer rubber and blended rubber thereof are preferably used. These rubber materials may be foamed or non-foamed.

As the conductive agent, an electronic conductive agent or an ionic conductive agent is used. Examples of electronic conductive agents include carbon blacks such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, and stainless steel; tin oxide, indium oxide, titanium oxide Examples thereof include fine powders such as various conductive metal oxides such as tin oxide-antimony oxide solid solution and tin oxide-indium oxide solid solution;
Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium; perchlorates and chlorates of alkaline earth metals Can be mentioned. These conductive agents may be used alone or in combination of two or more. Moreover, the addition amount is not particularly limited, but in the case of the electronic conductive agent, it is preferably in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the polymer, in the range of 15 to 25 parts by mass. More preferably. On the other hand, in the case of the ionic conductive agent, it is preferably in the range of 0.1 to 5.0 parts by mass, and in the range of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the polymer. Is more preferable.

The polymer material constituting the surface layer is not particularly limited as long as the dynamic ultrafine hardness of the surface of the charging roller 3 is 0.04 or more and 0.5 or less, as described above. Vinylidene, tetrafluoroethylene copolymer, polyester, polyimide, silicone resin, acrylic resin, polyvinyl butyral, ethylene tetrafluoroethylene copolymer, melamine resin, fluoro rubber, epoxy resin, polycarbonate, polyvinyl alcohol, cellulose, polyvinylidene chloride , Polyvinyl chloride, polyethylene, ethylene vinyl acetate copolymer and the like.
Among these, polyamide, polyvinylidene fluoride, tetrafluoroethylene copolymer, polyester, and polyimide are preferably used from the viewpoint of releasability with toner and the like. The above polymer materials may be used alone or in combination of two or more. Further, the number average molecular weight of the polymer material is preferably in the range of 1,000 to 100,000, and more preferably in the range of 10,000 to 50,000.

The surface layer is formed as a composition by mixing the polymer material with the conductive agent used in the conductive elastic layer and various fine particles. As the fine particles, metal oxides such as silicon oxide, aluminum oxide, barium titanate and complex metal oxides, and polymer fine powders such as tetrafluoroethylene and vinylidene fluoride are used alone or in combination. It is not limited to.
The developing means used in the process cartridge 12 of the present invention contacts the developer with the photosensitive member and develops the latent image formed on the photosensitive member into a toner image. As the developer, a two-component developer composed of a toner and a carrier or a one-component developer not containing a carrier can be used.
For example, as shown in FIG. 1, in the developing device 5, a developing roller 51 as a developer carrying member is partially exposed from an opening of the casing.
The toner replenished from the toner bottle (not shown) into the developing device 5 is conveyed while being agitated with the carrier by the agitating and conveying screws 52 and 53 and is carried on the developing roller 51. The developing roller 51 includes a magnet roller as magnetic field generating means and a developing sleeve that rotates coaxially therearound. The carrier in the developer is brought up on the developing roller 51 by the magnetic force generated by the magnet roller, and is conveyed to the developing region facing the photosensitive drum 1.

  Here, the developing roller 51 moves in the same direction at a linear velocity faster than the surface of the photosensitive drum 1 in the developing region. The carrier spiked on the developing roller 51 supplies the toner adhered to the carrier surface to the surface of the photosensitive drum 1 while rubbing the surface of the photosensitive drum 1. At this time, a developing bias is applied to the developing roller 51 from a power source (not shown), whereby a developing electric field is formed in the developing region. Then, between the electrostatic latent image on the photosensitive drum 1 and the developing roller 51, an electrostatic force toward the electrostatic latent image side acts on the toner on the developing roller 51. As a result, the toner on the developing roller 51 adheres to the electrostatic latent image on the photosensitive drum 1. By this adhesion, the electrostatic latent image on the photosensitive drum 1 is developed into a corresponding color toner image.

FIG. 2 is a cross-sectional view showing an example of a tandem type intermediate transfer type color copying machine 100 as an image forming apparatus having the protective layer forming apparatus 20 by including the process cartridge 12.
The color copying machine 100 includes an apparatus main body 101, a scanner 102 provided on the upper surface of the apparatus main body 101, and an automatic document feeder (ADF) 103 provided on the scanner 102.
A paper feed unit 104 including a plurality of paper feed cassettes 104a, 104b, 104c, and 104d is provided at the lower portion of the apparatus main body 101.
An endless intermediate transfer belt 105 as an intermediate transfer member is disposed at a substantially central portion of the apparatus main body 101. The intermediate transfer belt 105 is supported by being wound around a plurality of support rollers 106, 107, 108, and the like, and is driven to rotate clockwise in the drawing by a drive source (not shown).
In the vicinity of the support roller 108, an intermediate transfer member cleaning device 109 for removing residual toner remaining on the intermediate transfer belt 105 after the secondary transfer is provided.
On the intermediate transfer belt 105 stretched between the support roller 106 and the support roller 107, four colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged along the conveyance direction. Process cartridges 12Y, 12M, 12C, and 12K as image forming means are arranged side by side to constitute a tandem image forming unit 10. However, these four color orders are examples and are not intended to be limited to this.

An exposure device 8 is disposed above the tandem image forming unit 10. A secondary transfer roller 110 as a transfer device is disposed on the opposite side of the intermediate transfer belt 105 from the support roller 108. The image on the intermediate transfer belt 105 is transferred to a sheet (paper) fed from the paper feeding unit 104 by the secondary transfer roller 110.
On the left side of the secondary transfer roller 110, a fixing device 111 for fixing the transferred image on the sheet is provided. The fixing device 111 has a configuration in which a pressure roller 111b is pressed against an endless belt-like fixing belt 111a.
Below the fixing device 111, there is provided a sheet reversing device 112 for reversing the sheet when recording images on both sides of the sheet, substantially parallel to the tandem image forming unit 10 described above.

A series of processes for image formation will be described using a negative-positive process.
A photosensitive drum 1 typified by a photosensitive member (OPC) having an organic photoconductive layer is neutralized by a static elimination lamp (not shown) or the like, and is charged by a charging device (not shown) having a charging roller 3 as a charging member. Uniformly negatively charged.
When the photosensitive drum 1 is charged by the charging device, a voltage of an appropriate magnitude or a voltage suitable for charging the photosensitive drum 1 to a desired potential from a voltage application device (not shown) to the charging member 3 is used. A charging voltage in which an alternating voltage is superimposed on is applied.
The charged photosensitive drum 1 is formed with a latent image by laser light irradiated by an exposure device 8 such as a laser optical system (the absolute value of the exposed portion potential is lower than the absolute value of the non-exposed portion potential). Done.
Laser light is emitted from a semiconductor laser, and the surface of the photosensitive drum 1 is scanned in the rotational axis direction of the photosensitive drum 1 by a polygonal polygonal mirror (polygon) that rotates at high speed.

The latent image formed in this way is developed by a developer made of toner particles or a mixture of toner particles and carrier particles supplied onto a developing sleeve (developing roller 51) which is a developer carrying member in the developing device 5. Development is performed to form a toner visible image.
At the time of developing the latent image, a voltage of an appropriate magnitude between the exposed portion and the non-exposed portion of the photosensitive drum 1 or a development in which an AC voltage is superimposed on the developing sleeve from a voltage application mechanism (not shown). A bias is applied.
The toner image formed on the photosensitive drum 1 corresponding to each color is transferred onto the intermediate transfer belt 105 by a transfer roller 6 constituting a transfer device (not shown), and is fed from the paper feeding unit 104, or Overlaid toner images (color images) are collectively transferred by the secondary transfer roller 110 onto a transfer medium (sheet) such as paper fed from the manual feed tray 113.
At this time, it is preferable that a potential having a polarity opposite to the polarity of toner charging is applied to the transfer roller 6 as a transfer bias. Thereafter, the intermediate transfer belt 105 is separated from the photosensitive drum 1 to obtain a transfer image.

The toner particles remaining on the photosensitive drum 1 are cleaned by the cleaning member 41 and collected in the toner collection chamber in the cleaning device 4.
The sheet after the image transfer is sent to the fixing device 111 where heat and pressure are applied to fix the transferred image, and the sheet is stacked on the paper discharge tray 116 by the paper discharge roller pair 115.
Alternatively, the conveyance path is switched by a switching claw (not shown), put into the sheet reversing device 112, reversed there and guided again to the transfer position, and after the image is recorded also on the back surface, the paper discharge roller pair 115 discharges it. The paper is discharged onto the paper tray 116.
After the image transfer, the intermediate transfer belt 105 has the residual toner removed by the intermediate transfer member cleaning device 109, and prepares for another image formation by the tandem image forming unit 10.

  As described above, as the image forming apparatus, a plurality of developing devices are used, and a plurality of toner images with different colors sequentially produced by the plurality of developing devices are sequentially and sequentially transferred onto an intermediate transfer medium. It is not limited to the “tandem-type intermediate transfer method” in which the toner images are transferred to a transfer medium such as paper and then fixed, but a plurality of toner images similarly produced are sequentially placed on the transfer medium. A “tandem direct transfer method” or the like in which the image is fixed after being transferred in an overlapping manner may be used.

Further, the charging device described above is preferably a charging device disposed in contact with or close to the surface of the photoconductor, so that it can be compared with a corona discharge device called a corotron or a scorotron using a discharge wire. Thus, the amount of ozone generated during charging can be greatly suppressed.
However, in a charging device that performs charging by bringing a charging member into contact with or close to the surface of the photoconductor, as described above, discharge is performed in a region near the surface of the photoconductor, which tends to increase electrical stress on the photoconductor. is there. By using the protective layer forming apparatus using the protective agent of the present invention, the photoconductor can be maintained for a long time without deteriorating, so that it is possible to greatly suppress image changes over time and image changes due to use environments. As a result, stable image quality can be ensured.
In the present exemplary embodiment, the configuration including the protective agent coating apparatus 20 by including the process cartridge 12 is illustrated, but it is needless to say that the protective agent coating apparatus 20 may be directly provided in the image forming apparatus main body.

In the protective agent coating apparatus 20, the protective agent preferably contains 50 to 95% by weight of paraffin.
The ratio of paraffin in the protective agent in the present invention indicates the ratio with respect to all organic components contained in the protective agent, and when the protective agent contains an inorganic component, all the inorganic components are excluded. It represents the ratio of paraffin to organic components.
Further, although the threshold value of the index (Sb / Sa) varies somewhat depending on the ratio of paraffin in the protective agent, the good application amount of the protective agent on the photoconductor is not dependent on the ratio of paraffin. The Sb / Sa value on the photoconductor after 5 minutes of application of the protective agent described in 1 is sufficiently within the threshold value of 0.02 or more, and the Sb / Sa value on the photoconductor after 150 minutes of application is 0.85 or less. I know it will fit.

The protective agent used in the protective agent coating apparatus of the present invention is mainly composed of paraffin.
Examples of the paraffin used in the protective agent of the present invention include normal paraffin and isoparaffin. The paraffin may be used by mixing not only one kind but also different kinds of paraffin.
The proportion of paraffin in the protective agent used in the protective agent bar of the present invention is 50% by weight or more, preferably 60% by weight or more, and more preferably 70% by weight or more. When the proportion of paraffin is 50% by weight or less, the function as a protective agent is low, and the photoconductor is easily worn by image formation, which is not preferable.
If the ratio of paraffin is 95% by weight or more, it is difficult and difficult for paraffin to cover the surface of the photoreceptor. In the case of paraffin alone, it is indispensable to mix with other substances because it is thin on the photoconductor and hardly spreads in a film form only by the pressure of the brush or blade.

Examples of substances other than paraffin used in the protective bar of the present invention include amphiphilic organic compounds, aliphatic unsaturated hydrocarbons, alicyclic saturated hydrocarbons, alicyclic unsaturated hydrocarbons, and aromatic hydrocarbons. In addition to the classified hydrocarbons, polytetrafluoroethylene (PTFE), polyperfluoroalkyl ether (PFA), perfluoroethylene-perfluoropropylene copolymer (FEP), polyvinylidene fluoride (PVdF), ethylene -Fluorine resins such as tetrafluoroethylene copolymer (ETFE), fluorine waxes, silicone resins such as polymethyl silicone and polymethyl phenyl silicone, silicone waxes, inorganic compounds having lubricity such as mica, etc. Examples include, but are not limited to, amphiphilic organic compounds, alicyclic saturation. When the hydrocarbon is contained in the protective agent, the coating property of the protective agent is improved, and in particular, the alicyclic saturated hydrocarbon such as cyclic polyolefin can coat the protective agent on the photosensitive member in a film form, which is particularly preferable. . These compounds other than paraffin may be used not only in one kind but also in a mixture of many kinds.
Examples of the alicyclic saturated hydrocarbon include cycloparaffin and cyclic polyolefin.

Amphiphilic organic compounds are classified into anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, and composites thereof. Since the protective agent forms a protective agent layer on the photoconductor as described above and undergoes an image forming process, it is necessary not to adversely affect the electrical characteristics of the photoconductor.
By using a nonionic surfactant as an amphiphilic organic compound, the surfactant itself is not ionically dissociated, so air discharge etc. even when the usage environment, especially humidity, varies significantly Therefore, the image quality can be maintained at a high level.
The nonionic surfactant is preferably an esterified product of an alkyl carboxylic acid of the chemical formula (1) and a polyhydric alcohol.
CnH2n + 1COOH Chemical formula (1)
However, n in the formula represents an integer of 15 to 35. By using a linear alkyl carboxylic acid as the alkyl carboxylic acid of the chemical formula (1), the surface of the photoreceptor adsorbed the amphiphilic organic compound is amphiphilic. This is a preferable mode because the hydrophobic portion of the organic compound is easily arranged and the adsorption density on the surface of the support is particularly high.

The alkyl carboxylic acid ester in one molecule shows hydrophobicity, and the larger the number, the more the dissociable substances generated by air discharge are prevented from adsorbing to the surface of the photoconductor, and the surface of the photoconductor on the surface of the photoconductor is charged. This is effective for reducing electrical stress.
However, when the proportion of the alkyl carboxylic acid ester is too large, the portion of the polyhydric alcohol that exhibits hydrophilicity is covered and the sufficient adsorption performance may not be exhibited depending on the surface state of the photoreceptor.
Therefore, the average number of ester bonds per molecule of the amphiphilic organic compound is preferably 1 to 3.
The average number of ester bonds per molecule of these amphiphilic organic compounds can be adjusted by selecting one or more from a plurality of amphiphilic organic compounds having different numbers of ester bonds.
Examples of the amphiphilic organic compound include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant as described above.
Examples of anionic surfactants include alkylbenzene sulfonate, α-olefin sulfonate, alkane sulfonate, alkyl sulfate, alkyl polyoxyethylene sulfate, alkyl phosphate, long chain fatty acid salt, α -Anion (anion) at the end of the hydrophobic site, such as sulfo fatty acid ester salt and alkyl ether sulfate, and alkali metal ions such as sodium and potassium, and alkaline earth metal ions such as magnesium and calcium , Compounds in which metal ions such as aluminum and zinc, ammonium ions, and the like are bonded.
Examples of cationic surfactants include a cation (cation) at the end of a hydrophobic site, such as alkyltrimethylammonium salt, dialkylmethylammonium salt, alkyldimethylbenzylammonium salt, etc., and chlorine, fluorine , Bromine, and the like, and compounds in which phosphate ions, nitrate ions, sulfate ions, thiosulfate ions, carbonate ions, hydroxide ions, and the like are bonded.

Examples of amphoteric surfactants include dimethylalkylamine oxide, N-alkylbetaines, imidazoline derivatives, alkyl amino acids and the like.
Examples of nonionic surfactants include alcohol compounds such as long-chain alkyl alcohols, alkyl polyoxyethylene ethers, polyoxyethylene alkyl phenyl ethers, fatty acid diethanolamides, alkyl polyglucooxides, polyoxyethylene sorbitan alkyl esters, Examples include ether compounds and amide compounds. Also, long-chain alkyl carboxylic acids such as lauric acid, palmitic acid, stearic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, and melicic acid, and polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, erythritol, and hexitol. And ester compounds with these partial anhydrides are also preferred.
More specific examples of the ester compound include glyceryl monostearate, glyceryl distearate, glyceryl monopartic acid, glyceryl dilaurate, glyceryl trilaurate, glyceryl dipaltimate, glyceryl tripartinate, glyceryl dimyristate, and glyceryl trimistate. Glyceryl stearate, glyceryl stearate, glyceryl monoarachidate, glyceryl diarachidate, glyceryl monobehenate, glyceryl stearate, glyceryl stearate, glyceryl monomontanate, glyceryl monomelicate, and their substitutes, Sorbitan monostearate, sorbitan tristearate, sorbitan monopartitic acid, sorbitan dipartitic acid, Sorbitan palmitate, sorbitan dimyristate, sorbitan trimistate, sorbitan palmitate, sorbitan monoarachidate, sorbitan diarachidate, sorbitan dibehenate, sorbitan monobehenate, sorbitan stearate, sorbitan monostearate, sorbitan monomontanate, monomelicic acid Examples include, but are not limited to, sorbitan alkylcarboxylates such as sorbitan and substituted products thereof.
Moreover, these amphiphilic organic compounds may use a single kind, and may use multiple types together.
Furthermore, you may make it contain during filler protection, such as a metal oxide, a silicic acid compound, and a mica depending on the case.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.
The photosensitive member used was manufactured as follows.
(Photoconductor)
An undercoat layer, a charge generation layer, a charge transport layer, and a protective layer were applied in that order on an aluminum drum (conductive support) having a diameter of 30 mm, and then dried, and a 3.6 μm undercoat layer, about 0.0. A photoreceptor comprising a 14 μm charge generation layer, a 23 μm charge transport layer, and a protective layer of about 3.5 μm was prepared. At this time, the coating of the protective layer was performed by a spray method, and the others were performed by a dip coating method. Details of the protective layer were as follows.
(Protective layer)
Z-type polycarbonate 10 parts Triphenylamine compound (Structural formula 1 below) 7 parts Alumina fine particles (particle size 0.3 μm) 5 parts Tetrahydrofuran 400 parts Cyclohexanone 150 parts

Production of the protective agent bar used was carried out as follows.
(Method for producing protective agent bar 1)
88 parts by weight of FT115 (manufactured by Nippon Seiwa Wax), 12 parts by weight of TOPAS-TM (manufactured by Chicona), placed in a glass container with a lid, and stirred with a hot stirrer whose temperature is controlled at 160 to 250 ° C. While melting.
The protective agent, which has been stirred and melted, is poured so as to fill an aluminum mold having an internal size of 12 mm × 8 mm × 350 mm heated to 115 ° C. in advance, allowed to cool to 88 ° C. on a wooden table, and then an aluminum table The solid was removed from the mold and cooled to room temperature with a weight to prevent warpage.
After cooling, both ends in the longitudinal direction were cut and the bottom surface was cut to prepare a protective agent bar of 7 mm × 8 mm × 310 mm. Double-sided tape was affixed to the bottom of the protective agent bar and fixed to a metal support.

(Method for producing protective agent bar 2)
60 parts by weight of normal paraffin (average molecular weight 640), 40 parts by weight of sorbitan monostearate (HLB: 5.9), put in a glass container with a lid and stirring with a hot stirrer controlled to 180 ° C Melted.
The protective agent, which has been stirred and melted, is poured so as to fill an aluminum mold having an inner size of 12 mm × 8 mm × 350 mm heated to 115 ° C. in advance, allowed to cool to 90 ° C. on a wooden table, and then an aluminum table The solid was removed from the mold and cooled to room temperature with a weight on it to prevent warping.
After cooling, both ends in the longitudinal direction were cut and the bottom surface was cut to prepare a protective agent bar of 7 mm × 8 mm × 310 mm. Double-sided tape was affixed to the bottom of the protective agent bar and fixed to a metal support.

(Analysis of photoconductor before applying protective agent)
The protective agent bar 1 and the photoreceptor 1 were subjected to IR analysis using FT-IR Avatar 370 (Thermo Electron Co., Ltd., Thunder Dome (single reflection ATR, Ge, incident angle 45 °)).
In FIG. 7, A and B spectra (absorbance spectra) indicate the spectrum of the photoreceptor and the spectrum of the protective agent bar 1, respectively.
In the spectrum obtained with the photoconductor, a peak derived from carbonate (peak a1 (1770 cm-1)) was observed at 1770 cm-1. In the spectrum obtained with the protective agent bar 1, peaks derived from a methylene group (peak b1 (2850 cm-1), peak b2 (2920 cm-1)) were observed at 2850 cm-1 and 2920 cm-1.
Here, when the ATR measurement was performed on the photosensitive member, the photosensitive layer of the photosensitive member was peeled off from the aluminum substrate with a size of 1 cm × 1 cm using a cutter to obtain a measurement sample.

Further, XPS (AXIS / ULTRA, Shimadzu / KRATOS, X-ray source: Mono Al, analysis area: 700 × 300 μm) analysis of the photoreceptor 1 before applying the protective agent was performed, and a C1s spectrum as shown in FIG. 4 was obtained. Obtained. For the spectrum of FIG. 4, the total area of the peak (initial peak 1) having a peak top in the range of 290.3 to 294 eV (arrow range in the figure) is calculated by waveform separation of different bonded states of carbon. However, when the ratio (area ratio A0) to the waveform area of the entire C1s spectrum was obtained, it was 8.6%.
Here, the peaks detected in the range of 290.3 to 294 eV (peak top) are, as shown in FIG. 4, a peak derived from a carbonate bond (a portion adjacent to the right side of the hatched portion in the figure) and a π-π * transition. The peaks resulting from the separation (the hatched portion in the figure), and the peaks resulting from the π-π * transition, are present with several peaks overlapping.
When calculating the area, it takes a lot of time and effort to separate these peaks. Therefore, the waveform found in the range of 290.3 to 294 eV (peak top) is calculated as a lump area without waveform separation. did.
As described above, here, the peak in the range of 290.3 to 294 eV (peak top) was calculated as a lump area without waveform separation, but the peak in the range of 290.3 to 294 eV (peak top) was seen. When the peak to be overlapped with the bottom of the peak seen below 290.3 eV (peak top) and above 294 eV (peak top), it is necessary to calculate the area after separating each peak.

As in the case of the photoconductor 1, XPS analysis was performed on the photoconductor 2 before applying the protective agent, and the area ratio (A0) of the peak area of the peak 1 to the area of the entire C1s spectrum was found to be 8.8%. there were.
Also in the C1s spectrum obtained by XPS analysis for Photoreceptor 2, the peaks seen in the range of 290.3 to 294 eV (peak top) are seen below 290.3 eV (peak top) and above 294 eV (peak top). Since it did not overlap with the bottom of the peak to be obtained, the area calculation was performed by calculating the waveform seen in the range of 290.3 to 294 eV as a whole area.
Here, when performing the XPS measurement, the photoconductor was cut out with a size of 0.5 cm × 1 cm together with the Al substrate to obtain a measurement sample.

(Analysis after application of protective agent and calculation method of X and Y)
Analysis of the photoreceptor after application of the protective agent was performed as follows.
For photoreceptors 3 to 8 (after applying a protective agent for 120 minutes), which will be described later, sampling is performed, and a sample is used using FT-IR Avatar 370 (Thermo Electron Co., Ltd., ThunderDome (single reflection ATR, Ge, incident angle 45 °)). IR analysis was performed to obtain a spectrum (coating time 150 minutes) (absorbance spectrum) as shown in FIG. 7-C.
From the spectrum of FIG. 7-C, an attempt was made to obtain the ratio (Sb / Sa) of the area (Sb) of peak b1 (2850 cm-1) and the area (Sa) of peak a1 (1770 cm-1).
Here, the peak at 2850 cm −1 is a peak derived from the protective agent bar 1, but there is a peak derived from the photoconductor in the vicinity of this peak, and the peaks overlap each other. The difference spectrum between the spectrum obtained by the later photoconductor and the spectrum of the photoconductor only in FIG. 7-A is taken, and processing is performed so that the area of the peak at 2850 cm-1 is not affected by the area of the peak derived from the photoconductor. Then, X = Sb / Sa was obtained.
When taking the difference spectrum, a coefficient was applied to the absorbance of each spectrum so that the peak observed at 1770 cm −1 would be zero, and the peak intensity was adjusted by appropriately scaling.
Table 1 shows the integration range of wave numbers and areas at the start and end points of the background when determining the area of each peak.

In the same manner as before the application of the protective agent, XPS analysis was performed on the photoconductor after applying the protective agent for 120 minutes, and the C1s spectrum was within a range of 290.3 to 294 eV by waveform separation of different bonding states of carbon. Calculate the total area of the peak with the peak top (peak 1 after application), and obtain the ratio of the area to the waveform area of the entire C1s spectrum (area ratio A),
Y = ((A0−A) / A0 × 100) (%) was calculated. This calculation was performed for five random locations on each photoconductor, and the average value was obtained.
A0 relates to the C1s spectrum initially obtained by XPS analysis on the surface of the photoreceptor, and the peak obtained by separating the waveform resulting from different bonding states of carbon according to the binding energy is in the range of 290.3 to 294 eV. The ratio of the sum of the areas of peaks having peak tops (total area) to the entire area of the C1s spectrum is shown, and the average value of the XPS analysis results of the photoreceptors 1 and 2 was 8.7%.
A shows a C1s spectrum obtained by XPS analysis of the surface of the photoconductor after 120 minutes of application of the protective agent on the photoconductor, and separates the waveform resulting from different bonding states of carbon according to the binding energy. About the peak obtained by this, the ratio with respect to the area of the whole C1s spectrum after the said protective agent application | coating of the sum (total area) of the peak area which has a peak top in the range of 290.3-294 eV is shown.

(Examples 1-4, Comparative Examples 1-2)
The protective agent was applied to the photoreceptors 3 to 8 for 120 minutes using the following coating apparatus.
[Example 1]
In order to apply the protective agent of the protective agent bar 1 to the photoreceptor, the brush 3 (thickness: 20 denier, density: 50,000 per square inch) and urethane blade are mounted on the protective agent application device as shown in FIG. The brush was pressed against the photoconductor with a spring pressure of 4.8 N to apply the protective agent to the photoconductor 3 (protective agent application apparatus 1). The linear speeds of the photosensitive member and the brush were 125 mm / s and 146 mm / s, respectively.
The photoconductor after application of the protective agent was subjected to IR analysis using FT-IR Avatar 370 (Thermo Electron Co., Ltd., ThunderDome (single reflection ATR, Ge, incident angle 45 °)), and X was calculated.
Further, the XPS (AXIS / ULTRA, Shimadzu / KRATOS, X-ray source: Mono Al, analysis area: 700 × 300 μm) analysis was performed on the photoreceptor after applying the protective agent, and Y was calculated. From the calculated X and Y, X / Y was found to be 0.0033.
Next, in the black photoconductor unit of IPSIO CX400 (tandem type color image forming apparatus, manufactured by Ricoh), a new photoconductor is incorporated, a charging roller is disposed immediately above the photoconductor, and the linear velocity of the photoconductor is 125 mm. The evaluation was performed by applying an AC voltage having a frequency of 1450 Hz and an amplitude of 1100 V superimposed on a DC voltage of −600 V between the photosensitive member and the charging roller. At this time, the black photoconductor unit was set so as to satisfy the same conditions as the protective agent coating apparatus condition 1.

When 150 black character images were output and evaluated using the image forming apparatus set as described above, the images were high-quality images.
Subsequently, a total of 6000 1-by1 halftone images of A4 size paper as shown in FIG. 6 were output. As a result, the 6000th image was a high-quality image in visual evaluation. Furthermore, when the 6000th image was observed with a microscope, the dots were not disturbed and beautiful dots were arranged.

[Example 2]
In order to apply the protective agent of the protective agent bar 1 to the photoreceptor, the brush 2 (thickness: 10 denier, density: 50,000 per square inch) and urethane blade are mounted on the protective agent application device as shown in FIG. The brush was pressed against the photoconductor with a spring pressure of 4.8 N to apply the protective agent to the photoconductor 4 (protective agent application device 2). The linear speeds of the photosensitive member and the brush were 125 mm / s and 146 mm / s, respectively.
The photoconductor after application of the protective agent was subjected to IR analysis using FT-IR Avatar 370 (Thermo Electron Co., Ltd., ThunderDome (single reflection ATR, Ge, incident angle 45 °)), and X was calculated.
XPS (AXIS / ULTRA, Shimadzu / KRATOS, X-ray source: Mono Al, analysis area: 700 × 300 μm) analysis was performed on the photoconductor after the protective agent was applied, and Y was calculated. From the calculated X and Y, X / Y was found to be 0.0025.

Next, in the black photoconductor unit of IPSIO CX400 (tandem type color image forming apparatus, manufactured by Ricoh), a new photoconductor is incorporated, a charging roller is disposed immediately above the photoconductor, and the linear velocity of the photoconductor is 125 mm. The evaluation was performed by applying an AC voltage having a frequency of 1450 Hz and an amplitude of 1100 V superimposed on a DC voltage of −600 V between the photosensitive member and the charging roller.
At this time, the black photoconductor unit was set so as to be in the same condition as condition 2 of the protective agent coating apparatus.
When 150 black character images were output and evaluated using the image forming apparatus set as described above, the images were high-quality images.
Subsequently, a total of 6000 1-by1 halftone images of A4 size paper as shown in FIG. 6 were output. As a result, the 6000th image was a high-quality image in visual evaluation. Furthermore, when the 6000th image was observed with a microscope, the dots were not disturbed and beautiful dots were arranged.

[Comparative Example 1]
In order to apply the protective agent of the protective agent bar 2 to the photoreceptor, the brush 1 (thickness: 20 denier, density: 100,000 per square inch) and urethane blade are mounted on the protective agent application device as shown in FIG. Then, the brush was pressed against the photoconductor with a spring pressure of 6N, and a protective agent was applied to the photoconductor 5 (protective agent coating device 3). The linear speeds of the photosensitive member and the brush were 125 mm / s and 146 mm / s, respectively.
The photoconductor after application of the protective agent was subjected to IR analysis using FT-IR Avatar 370 (Thermo Electron Co., Ltd., ThunderDome (single reflection ATR, Ge, incident angle 45 °)), and X was calculated.
Further, the XPS (AXIS / ULTRA, Shimadzu / KRATOS, X-ray source: Mono Al, analysis area: 700 × 300 μm) analysis was performed on the photoreceptor after applying the protective agent, and Y was calculated. From the calculated X and Y, X / Y was 0.0242.
Next, in the black photoconductor unit of IPSIO CX400 (tandem type color image forming apparatus, manufactured by Ricoh), a new photoconductor is incorporated, a charging roller is disposed immediately above the photoconductor, and the linear velocity of the photoconductor is 125 mm. The evaluation was performed by applying an AC voltage having a frequency of 1450 Hz and an amplitude of 1100 V superimposed on a DC voltage of −600 V between the photosensitive member and the charging roller. At this time, the black photoconductor unit was set so as to be in the same condition as the protective agent coating apparatus condition 3.
When the image forming apparatus set as described above was used to output and evaluate 150 black character images, the characters in the image were slightly thicker. The image output in Example 1 and the image output in Comparative Example 1 were observed using a microscope. As a result, in the image of Example 1, the dots were sharp, but in the image of Comparative Example 1, the spread of the dots was observed.
Subsequently, a total of 6000 1-by1 halftone images of A4 size paper as shown in FIG. 6 were output. As a result, white stripes were seen in the 6000th image.

[Comparative Example 2]
In order to apply the protective agent of the protective agent bar 2 to the photoreceptor, the brush 1 (thickness: 20 denier, density: 100,000 per square inch) and urethane blade are mounted on the protective agent application device as shown in FIG. Then, the brush was pressed against the photoconductor with a spring pressure of 5N, and a protective agent was applied to the photoconductor 6 (protective agent application device 4). The linear speeds of the photosensitive member and the brush were 125 mm / s and 146 mm / s, respectively.
The photoconductor after application of the protective agent was subjected to IR analysis using FT-IR Avatar 370 (Thermo Electron Co., Ltd., ThunderDome (single reflection ATR, Ge, incident angle 45 °)), and X was calculated.
Further, the XPS (AXIS / ULTRA, Shimadzu / KRATOS, X-ray source: Mono Al, analysis area: 700 × 300 μm) analysis was performed on the photoreceptor after applying the protective agent, and Y was calculated. From the calculated X and Y, X / Y was 0.0220.
Next, in the black photoconductor unit of IPSIO CX400 (tandem type color image forming apparatus, manufactured by Ricoh), a new photoconductor is incorporated, a charging roller is disposed immediately above the photoconductor, and the linear velocity of the photoconductor is 125 mm. The evaluation was performed by applying an AC voltage having a frequency of 1450 Hz and an amplitude of 1100 V superimposed on a DC voltage of −600 V between the photosensitive member and the charging roller. At this time, the black photoconductor unit was set so as to satisfy the same conditions as the protective agent coating apparatus condition 4.
When the image forming apparatus set as described above was used to output and evaluate 150 black character images, the characters in the image were slightly thicker. The image output in Comparative Example 1 was observed using SEM. As a result, the spread of dots was observed in the image of Comparative Example 2 as compared with the image of Example 1.
Subsequently, a total of 6000 1-by1 halftone images of A4 size paper as shown in FIG. 6 were output. As a result, white stripes were seen in the 6000th image.

[Example 3]
In order to apply the protective agent of the protective agent bar 2 to the photoreceptor, the brush 2 (thickness: 10 denier, density: 50,000 per square inch) and urethane blade are mounted on the protective agent application device as shown in FIG. Then, the brush was pressed against the photoconductor with a spring pressure of 3.5 N, and a protective agent was applied to the photoconductor 7 (protective agent application device 5). The linear speeds of the photosensitive member and the brush were 125 mm / s and 146 mm / s, respectively.
The photoconductor after application of the protective agent was subjected to IR analysis using FT-IR Avatar 370 (Thermo Electron Co., Ltd., ThunderDome (single reflection ATR, Ge, incident angle 45 °)), and X was calculated.
Further, the XPS (AXIS / ULTRA, Shimadzu / KRATOS, X-ray source: Mono Al, analysis area: 700 × 300 μm) analysis was performed on the photoreceptor after applying the protective agent, and Y was calculated. From the calculated X and Y, X / Y was 0.014.
Next, in the black photoconductor unit of IPSIO CX400 (tandem type color image forming apparatus, manufactured by Ricoh), a new photoconductor is incorporated, a charging roller is disposed immediately above the photoconductor, and the linear velocity of the photoconductor is 125 mm. The evaluation was performed by applying an AC voltage having a frequency of 1450 Hz and an amplitude of 1100 V superimposed on a DC voltage of −600 V between the photosensitive member and the charging roller. At this time, the black photoconductor unit was set so as to satisfy the same conditions as the protective agent coating apparatus condition 5.
When 150 black character images were output and evaluated using the image forming apparatus set as described above, the images were high-quality images.
Subsequently, a total of 6000 1-by1 halftone images of A4 size paper as shown in FIG. 6 were output. As a result, the 6000th image was a high-quality image in visual evaluation. Furthermore, when the 6000th image was observed with a microscope, the spread of dots was observed in some places.

[Example 4]
In order to apply the protective agent of the protective agent bar 1 to the photoreceptor, the brush 1 (thickness: 20 denier, density: 100,000 per square inch) and urethane blade are mounted on the protective agent application device as shown in FIG. Then, the brush was pressed against the photoconductor with a spring pressure of 6N, and a protective agent was applied to the photoconductor 8 (protective agent coating device 6). The linear speeds of the photosensitive member and the brush were 125 mm / s and 146 mm / s, respectively.
The photoconductor after application of the protective agent was subjected to IR analysis using FT-IR Avatar 370 (Thermo Electron Co., Ltd., ThunderDome (single reflection ATR, Ge, incident angle 45 °)), and X was calculated.
Further, the XPS (AXIS / ULTRA, Shimadzu / KRATOS, X-ray source: Mono Al, analysis area: 700 × 300 μm) analysis was performed on the photoreceptor after applying the protective agent, and Y was calculated. From the calculated X and Y, X / Y was found to be 0.0059.
Next, in the black photoconductor unit of IPSIO CX400 (tandem type color image forming apparatus, manufactured by Ricoh), a new photoconductor is incorporated, a charging roller is disposed immediately above the photoconductor, and the linear velocity of the photoconductor is 125 mm. The evaluation was performed by applying an AC voltage having a frequency of 1450 Hz and an amplitude of 1100 V superimposed on a DC voltage of −600 V between the photosensitive member and the charging roller. At this time, the black photoconductor unit was set so as to satisfy the same conditions as the protective agent coating apparatus condition 6.
When 150 black character images were output and evaluated using the image forming apparatus set as described above, the images were high-quality images.
Subsequently, a total of 6000 1-by1 halftone images of A4 size paper as shown in FIG. 6 were output. As a result, the 6000th image was a high-quality image in visual evaluation. Furthermore, when the 6000th image was observed with a microscope, the dots were not disturbed and beautiful dots were arranged.

Table 2 summarizes the above experimental results. Table 3 summarizes the experimental specifications of the protective agent bar. The meanings of symbols in the column of evaluation results in Table 1 are as follows.
○: High image quality △: Cannot be confirmed by visual observation, but there is degradation in image quality when magnified with a microscope (no problem in actual use)
×: Abnormal image

Next, a photoconductor preferably used in this embodiment (the present invention) will be described.
In the photoreceptor used in the image forming apparatus of the present invention, a photosensitive layer is provided on a conductive support. The photosensitive layer is composed of a single layer type in which a charge generation material and a charge transport material are mixed, a forward layer type in which a charge transport layer is provided on the charge generation layer, or a charge generation layer provided on the charge transport layer. There is a reverse layer type.
In addition, a protective layer can be provided on the photosensitive layer in order to improve the mechanical strength, abrasion resistance, gas resistance, cleaning property, and the like of the photoreceptor. An undercoat layer may be provided between the photosensitive layer and the conductive support. In addition, an appropriate amount of a plasticizer, an antioxidant, a leveling agent and the like can be added to each layer as necessary.
Examples of the conductive support for the photoreceptor include those having a volume resistance of 1010 Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, indium oxide, etc. A metal or oxide film, or a plastic film or paper coated by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel, etc. After forming the tube, a tube subjected to surface treatment such as cutting, super-finishing or polishing can be used.
A drum-shaped support having a diameter of 20 to 150 mm, preferably 24 to 100 mm, and more preferably 28 to 70 mm can be used. If the diameter of the drum-shaped support is 20 mm or less, it is physically difficult to arrange the charging, exposure, development, transfer, and cleaning steps around the drum. If the diameter of the drum-shaped support is 150 mm or more, image formation is performed. The apparatus becomes undesirably large. In particular, when the image forming apparatus is a tandem type, it is necessary to mount a plurality of photoconductors, and therefore the diameter is preferably 70 mm or less, and preferably 60 mm or less. Further, endless nickel belts and endless stainless steel belts disclosed in JP-A-52-36016 can also be used as the conductive support.

  As the undercoat layer of the photosensitive member used in the image forming apparatus of the present invention, a resin or a material mainly composed of a white pigment and a resin, a metal oxide film obtained by chemically or electrochemically oxidizing the surface of a conductive substrate, etc. However, those containing a white pigment and a resin as main components are preferable. Examples of the white pigment include metal oxides such as titanium oxide, aluminum oxide, zirconium oxide, and zinc oxide. Among them, it is most preferable to contain titanium oxide that is excellent in preventing charge injection from the conductive substrate. As the resin used for the undercoat layer, thermoplastic resins such as polyamide, polyvinyl alcohol, casein, and methyl cellulose, thermosetting resins such as acrylic, phenol, melamine, alkyd, unsaturated polyester, and epoxy, one or various kinds of these Mixtures can be exemplified.

  Examples of the charge generating material for the photoreceptor used in the image forming apparatus of the present invention include azo pigments such as monoazo pigments, bisazo pigments, trisazo pigments, and tetrakisazo pigments, triarylmethane dyes, thiazine dyes, and oxazines. Dyes, xanthene dyes, cyanine dyes, styryl dyes, pyrylium dyes, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indanthrone pigments, squarylium pigments Inorganic materials such as pigments, organic pigments and dyes such as phthalocyanine pigments, selenium, selenium-arsenic, selenium-tellurium, cadmium sulfide, zinc oxide, titanium oxide, and amorphous silicon can be used. It can be used alone or in combination. The undercoat layer may be a single layer or a plurality of layers.

Examples of the charge transport material for the photoreceptor used in the image forming apparatus of the present invention include anthracene derivatives, pyrene derivatives, carbazole derivatives, tetrazole derivatives, metallocene derivatives, phenothiazine derivatives, pyrazoline compounds, hydrazone compounds, styryl compounds, styryl hydrazone compounds, Enamine compounds, butadiene compounds, distyryl compounds, oxazole compounds, oxadiazole compounds, thiazole compounds, imidazole compounds, triphenylamine derivatives, phenylenediamine derivatives, aminostilbene derivatives, triphenylmethane derivatives, etc. can do.
The binder resin used to form the photosensitive layer of the charge generation layer and the charge transport layer is electrically insulating and is a known thermoplastic resin, thermosetting resin, photocurable resin, and photoconductive material. Suitable binder resins include, for example, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, Ethylene-vinyl acetate copolymer, polyvinyl butyral, polyvinyl acetal, polyester, phenoxy resin, (meth) acrylic resin, polystyrene, polycarbonate, polyarylate, polysulfone, polyethersulfone, ABS resin and other thermoplastic resins, phenolic resin, epoxy Resin, urethane resin, melamine resin, isocyanate resin, alkyd resin, Examples thereof include a thermosetting resin such as a ricone resin, a thermosetting acrylic resin, a type of binder resin such as a photoconductive resin such as polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene, or a mixture of various types of binder resins. In particular, it is not limited to these.

As antioxidant, the following are used, for example.
(Monophenol compound)
2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate, 3-t-butyl-4-hydroxynisol and the like.
(Bisphenol compounds)
2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2′-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4′-thiobis- ( 3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol) and the like.
(High molecular phenolic compounds)
1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t- Butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4 ′ -Hydroxy-3'-t-butylphenyl) butyric acid] glycol ester, tocophenols and the like.
(Paraphenylenediamines)
N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'- Di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.
(Hydroquinones)
2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) ) -5-methylhydroquinone and the like.
(Organic sulfur compounds)
Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.
(Organic phosphorus compounds)
Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.

As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is about 0 to 30 parts by weight with respect to 100 parts by weight of the binder resin. Is appropriate.
A leveling agent may be added to the charge transport layer. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the chain are used, and the amount used is 100 parts by weight of binder resin. 0 to 1 part by weight is suitable.
As described above, the surface layer is provided to improve the mechanical strength, abrasion resistance, gas resistance, cleaning property, etc. of the photoreceptor. Examples of the surface layer include a polymer having higher mechanical strength than the photosensitive layer, and a polymer in which an inorganic filler is dispersed.
The polymer used for the surface layer may be either a thermoplastic polymer or a thermosetting polymer, but the thermosetting polymer has a high mechanical strength and does not wear due to friction with the cleaning blade. It is very preferable because of its extremely high ability to suppress. If the surface layer is thin, there is no problem even if it does not have the charge transport capability, but if the surface layer without the charge transport capability is formed thick, the sensitivity of the photoreceptor decreases, the potential increases after exposure, and the residual layer Since the potential rise is likely to occur, it is preferable to use the above-mentioned charge transporting substance in the surface layer or to use a polymer having a charge transporting capability for the protective layer.

When the surface layer is provided, the mechanical strength of the photosensitive layer and the surface layer is generally greatly different, and therefore the protective layer is worn away due to friction with the cleaning blade. It is important that the surface layer has a sufficient film thickness, and is 0.01 to 12 μm, preferably 1 to 10 μm, more preferably 2 to 8 μm. If the film thickness of the surface layer is 0.1 μm or less, it is not preferable because it is too thin and easily disappears due to friction with the cleaning blade, and wear of the photosensitive layer proceeds from the disappeared portion.
When the film thickness of the surface layer is 12 μm or more, the sensitivity is lowered, the potential after exposure is increased, and the residual potential is easily increased. In particular, when a polymer having charge transport capability is used, the cost of the polymer having charge transport capability is high. This is not preferable.

  As the polymer used for the surface layer, polycarbonate that is transparent to the writing light at the time of image formation and excellent in insulation, mechanical strength, and adhesiveness is used. In addition, ABS resin, ACS resin, olefin- Vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, polybutylene terephthalate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin , Polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, epoxy resin, etc. It may be.

  In the surface layer, fine particles of metal or metal oxide can be dispersed in order to increase the mechanical strength of the surface layer. Examples of the metal oxide include titanium oxide, tin oxide, potassium titanate, TiO, TiN, zinc oxide, indium oxide, and antimony oxide. In addition, for the purpose of improving wear resistance, fluorine resins such as polytetrafluoroethylene, silicone resins, and those obtained by dispersing inorganic materials such as these resins can be added.

The photoconductor of the present invention is an intermediate transfer used for image formation by a so-called intermediate transfer method in which a toner image formed on a photoconductor is primarily transferred to perform color superposition and further transferred to a transfer medium. It may be a medium.
As the intermediate transfer medium, a medium having a volume resistance of 105 to 1011 Ω · cm is preferable. When the surface resistance is less than 105Ω / □, when the toner image is transferred from the photoconductor onto the intermediate transfer medium, so-called transfer dust may be generated in which the toner image is disturbed due to discharge. In the case of exceeding, the toner image may be transferred from the intermediate transfer medium to a transfer medium such as paper, and then the counter charge of the toner image may remain on the intermediate transfer medium and appear as a residual image on the next image.
As an intermediate transfer medium, for example, a metal oxide such as tin oxide or indium oxide, a conductive particle such as carbon black, or a conductive polymer, alone or in combination, kneaded with a thermoplastic resin, and then extruded into a belt shape Alternatively, a cylindrical plastic can be used. In addition, the above-mentioned conductive particles and conductive polymer are added to a resin solution containing a thermal crosslinking reactive monomer or oligomer, if necessary, and subjected to centrifugal molding while heating to obtain an intermediate transfer medium on an endless belt. You can also.
When providing a surface layer on the intermediate transfer medium, among the surface layer materials used for the above-mentioned photoreceptor surface layer, the composition excluding the charge transport material is appropriately combined with a conductive substance to adjust the resistance, Can be used.

Next, the toner suitably used in the present invention will be described.
First, the toner of the present invention preferably has an average circularity of 0.93 to 1.00. In the present invention, the value obtained from the following formula (3) is defined as circularity. This circularity is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated.
Circularity SR = peripheral length of circle having the same area as the projected particle area / perimeter length of projected particle image (3)
When the average circularity is in the range of 0.93 to 1.00, the surface of the toner particles is smooth, and the contact area between the toner particles and between the toner particles and the photosensitive member is small, so that the transferability is excellent.
Since the toner particles have no corners, the developer agitation torque in the developing device is small, and the agitation drive is stabilized, so that no abnormal image is generated.
Since there are no angular toner particles in the toner that forms the dots, when the pressure is brought into contact with the transfer medium during the transfer, the pressure is uniformly applied to the entire toner that forms the dots, and the transfer is not easily lost.
Since the toner particles are not angular, the abrasive power of the toner particles themselves is small, and the surface of the image carrier is not damaged or worn.

Next, a method for measuring the circularity will be described.
The circularity can be measured using a flow type particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics.
As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes.

In the present invention, the weight average diameter D4 of the toner is preferably 3 to 10 μm.
In this range, since the toner particles have a sufficiently small particle size with respect to the minute latent image dots, the dot reproducibility is excellent.
If the weight average diameter D4 is less than 3 μm, phenomena such as a decrease in transfer efficiency and a decrease in blade cleaning properties tend to occur.
When the weight average diameter D4 exceeds 10 μm, it is difficult to suppress scattering of characters and lines.

In the toner of the present invention, the ratio of the weight average diameter D4 to the number average diameter D1 (D4 / D1) is preferably 1.00 to 1.40. The closer the value of (D4 / D1) is to 1, the sharper the particle size distribution of the toner.
Therefore, when (D4 / D1) is in the range of 1.00 to 1.40, the selective development due to the toner particle size does not occur, and the stability of the image quality is excellent.
Since the toner particle size distribution is sharp, the triboelectric charge amount distribution is also sharp, and fogging is suppressed.
When the toner particle size is uniform, the latent image dots are developed so that they are densely and neatly arranged, and the dot reproducibility is excellent.

Next, a method for measuring the particle size distribution of toner particles will be described.
Examples of the measuring device for the particle size distribution of toner particles by the Coulter counter method include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average diameter D4 and the number average diameter D1 of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

  In addition, as such a substantially spherical toner, a toner composition containing a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent in an aqueous medium in the presence of fine resin particles. A toner that undergoes crosslinking and / or elongation reaction is preferred. The toner produced by this reaction can reduce the hot offset by curing the toner surface, and can prevent the fixing device from becoming dirty and appearing on the image.

Examples of the prepolymer comprising a modified polyester resin that can be used for toner preparation include a polyester prepolymer (A) having an isocyanate group, and examples of a compound that extends or crosslinks with the prepolymer include amines (B). Can be mentioned.
Examples of the polyester prepolymer (A) having an isocyanate group include a polycondensate of a polyol (1) and a polycarboxylic acid (2) and a polyester having an active hydrogen group, which is further reacted with a polyisocyanate (3). Can be mentioned. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.
Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Mixtures are preferred. Diol (1-1) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide phenol compound (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyol (1-2) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( The mixture of 2-2) is preferable. Dicarboxylic acid (2-1) includes alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, and the like). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.
The ratio of the polyol (1) and the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably 1. as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 5/1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; polyisocyanates such as phenol derivatives, oximes, caprolactam And a combination of two or more of these.
The ratio of the polyisocyanate (3) is usually 5/1 to 1/1, preferably 4 /, as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1.
When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate. The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. It is. If it is less than 0.5% by weight, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by weight, the low-temperature fixability deteriorates.

The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.
As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1-B5 blocked (B6). Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of B1 to B5 blocked amino groups (B6) include ketimine compounds and oxazoline compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

Furthermore, if necessary, the molecular weight of the urea-modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. [NCO] / [NHx] exceeds 2 or 1/2
If it is less than 1, the molecular weight of the urea-modified polyester (i) becomes low, and the hot offset resistance deteriorates. In the present invention, the polyester (i) modified with a urea bond may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

By these reactions, the modified polyester used in the toner of the present invention, especially the urea-modified polyester (i) can be prepared. These urea-modified polyesters (i) are produced by a one-shot method or a prepolymer method. The weight average molecular weight of the urea-modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester is not particularly limited when using the unmodified polyester (ii) described later, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.
Moreover, in this invention, not only polyester (i) modified | denatured with the said urea bond but polyester (ii) which is not modified | denatured with this (i) can also be contained as a binder resin component. By using (ii) in combination, the low-temperature fixability and glossiness when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component (i) above, and preferred ones are also the same as (i). Further, (ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, for example, may be modified with a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, the polyester component (i) and (ii) preferably have similar compositions. In the case of containing (ii), the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. If the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (ii) is usually 1000-30000, preferably 1500-10000, more preferably 2000-8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is usually 1-30, preferably 5-20. By having an acid value, it tends to be negatively charged.

In the present invention, the glass transition point (Tg) of the binder resin is usually 50 to 70 ° C., preferably 55 to 65 ° C. If it is less than 50 ° C., the blocking of the toner during high temperature storage deteriorates, and if it exceeds 70 ° C., the low temperature fixability becomes insufficient. Due to the coexistence of the urea-modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester-based toners. As the storage elastic modulus of the binder resin, the temperature (TG ′) at which 10000 dyne / cm 2 is obtained at a measurement frequency of 20 Hz is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the binder resin, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or less, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, from the viewpoint of achieving both low temperature fixability and hot offset resistance, TG ′ is preferably higher than Tη. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher.
More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

  The binder resin can be produced by the following method. The polyol (1) and the polycarboxylic acid (2) are heated to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and the generated water is distilled off as necessary. Thus, a polyester having a hydroxyl group is obtained. Next, this is reacted with polyisocyanate (3) at 40 to 140 ° C. to obtain a prepolymer (A) having an isocyanate group. Further, (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When (3) is reacted and (A) and (B) are reacted, a solvent can be used as necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to the isocyanate (3), such as tetrahydrofuran (such as tetrahydrofuran). When polyester (ii) not modified with urea bond is used in combination, (ii) is produced in the same manner as polyester having a hydroxyl group, and this is dissolved in the solution after completion of the reaction of (i) and mixed. To do.

In addition, the toner used in the present invention can be produced generally by the following method, but is not limited thereto.
As an aqueous medium used in the present invention, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like.
The toner particles may be formed by reacting a dispersion made of a prepolymer (A) having an isocyanate group in an aqueous medium with (B), or using a urea-modified polyester (i) produced in advance. good. As a method for stably forming a dispersion comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium, a toner raw material comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium is used. And a method of dispersing by shearing force. The prepolymer (A) and other toner compositions (hereinafter referred to as toner raw materials), a colorant masterbatch, a release agent, a charge control agent, an unmodified polyester resin, etc. are dispersed in an aqueous medium. It may be mixed at the time of formation, but it is more preferable to mix the toner raw materials in advance and then add and disperse the mixture in the aqueous medium. In the present invention, other toner materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium, but after the particles are formed. , May be added. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.

The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferred in that the dispersion made of urea-modified polyester (i) or prepolymer (A) has a low viscosity and is easily dispersed.
The amount of the aqueous medium used relative to 100 parts of the toner composition containing the urea-modified polyester (i) and the prepolymer (A) is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

In the step of synthesizing the urea-modified polyester (i) from the prepolymer (A), the amine (B) may be added and reacted before the toner composition is dispersed in the aqueous medium, or may be dispersed in the aqueous medium. An amine (B) may be added later to cause a reaction from the particle interface. In this case, urea-modified polyester is preferentially produced on the surface of the toner to be produced, and a concentration gradient can be provided inside the particles.
Anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphates, etc., alkylamines as dispersants for emulsifying and dispersing the oily phase in which the toner composition is dispersed in a liquid containing water Amine salts such as salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, etc. Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives, such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl N, amphoteric surfactants such as N-dimethyl ammonium betaine and the like.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 31- [omega-fluoroalkyl (C6-C11) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) mono-N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carboxylic acid and metal salt, Perfluoroalkylcarboxylic acid (C7 to C13) and its metal salt, perfluoroalkyl (C4 to C12) sulfonic acid and its metal salt, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2hydroxyethyl) -Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Is mentioned.

Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-1101 , DS-102, (Taikin Kogyo Co., Ltd.), Megafuck F-l0, F-l20, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF-ichi 102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).
Further, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6 1 C10) sulfonamidopropyltrimethylammonium salt which right the fluoroalkyl group, Benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, trade names include Surflon S-21 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries Co., Ltd.) ), Megafuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-32 (Tochem Products Co., Ltd.), Footgent F 1300 (Neos Co., Ltd.), and the like.

Further, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like can be used as an inorganic compound dispersant which is hardly soluble in water.
Further, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups, For example, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloro-2-acrylate -Hydroxypropyl, 3-chloro-2-methacrylic acid methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N -Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or esters of compounds containing vinyl alcohol and carboxyl groups For example, pinyl acetate, pinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, pinylviridine, vinylpyrrolidone, vinylimidazole, ethyleneimine Homopolymers or copolymers such as those having a nitrogen atom or its heterocyclic ring, polyoxyethylene, polyoxypropylene, Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and then washing with water. To do. It can also be removed by operations such as enzymatic degradation.
When a dispersant is used, the dispersant may remain on the surface of the toner particles, but it is preferable from the charged surface of the toner that the dispersant is washed and removed after the elongation and / or crosslinking reaction.
Furthermore, in order to lower the viscosity of the toner composition, a solvent in which the urea-modified polyester (i) or the prepolymer (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred, and aromatic solvents such as toluene and xylene are more preferred. The usage-amount of the solvent with respect to 100 parts of prepolymers (A) is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after elongation and / or crosslinking reaction.

The elongation and / or cross-linking reaction time is selected depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. is there. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.
In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, the emulsified dispersion can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, particularly various air streams heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used are generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.
When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying into a desired particle size distribution.

In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be wet.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.
By mixing the resulting dried toner powder with dissimilar particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or by giving mechanical impact force to the mixed powder By immobilizing and fusing on the surface, it is possible to prevent detachment of the foreign particles from the surface of the resulting composite particle.

  Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, etc.

As the colorant used in the toner, pigments and dyes conventionally used as toner colorants can be used. Specifically, carbon black, lamp black, iron black, ultramarine, nigrosine dye, Aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6C lake, chalcoa oil blue, chrome yellow, quinacridone red, benzidine yellow, rose bengal and the like can be used alone or in combination.
Furthermore, if necessary, in order to give the toner particles magnetic properties, magnetic components such as iron oxides such as ferrite, magnetite and maghemite, metals such as iron, cobalt and nickel, or alloys of these with other metals. May be contained alone or in combination in the toner particles. Moreover, these components can also be used / used together as a colorant component.

The number average diameter of the colorant in the toner used in the present invention is desirably 0.5 μm or less, preferably 0.4 μm or less, more preferably 0.3 μm or less.
When the number average diameter of the colorant in the toner is larger than 0.5 μm, the dispersibility of the pigment does not reach a sufficient level, and preferable transparency may not be obtained.
A colorant having a fine particle diameter of less than 0.1 μm is sufficiently smaller than a half wavelength of visible light, and thus is considered not to adversely affect light reflection and absorption characteristics. Therefore, the colorant particles of less than 0.1 μm contribute to good color reproducibility and transparency of the OHP sheet having a fixed image. On the other hand, if there are many colorants having a particle size larger than 0.5 μm, the transmission of incident light is hindered or scattered, and the brightness and color of the projected image of the OHP sheet tend to decrease. There is.
Further, if there are many colorants having a particle diameter larger than 0.5 μm, the colorant is detached from the surface of the toner particles and easily causes various problems such as fogging, drum contamination, and poor cleaning, which is not preferable. In particular, the colorant having a particle size larger than 0.7 μm is preferably 10% by number or less, more preferably 5% by number or less of the total colorant.
In addition, by adding a wetting liquid in advance with a part or all of the binder resin and kneading the colorant, the binder resin and the colorant are initially sufficiently adhered, In the toner production process, the colorant is dispersed more effectively in the toner particles, the dispersed particle diameter of the colorant is reduced, and better transparency can be obtained.

As the binder resin used for kneading in advance, the resins exemplified as the binder resin for toner can be used as they are, but are not limited thereto.
As a specific method for kneading the mixture of the binder resin and the colorant with the wetting liquid in advance, for example, the binder resin, the colorant and the wetting liquid are obtained after mixing with a blender such as a Henschel mixer. The obtained mixture is kneaded at a temperature lower than the melting temperature of the binder resin by a kneader such as a two-roll or three-roll to obtain a sample.
In addition, as the wetting liquid, a general one can be used in consideration of the solubility of the binder resin and the paintability with the colorant, but in particular, an organic solvent such as acetone, toluene, butanone, or water, It is preferable from the viewpoint of dispersibility of the colorant.
Among these, the use of water is more preferable from the viewpoint of environmental considerations and maintaining the dispersion stability of the colorant in the subsequent toner production process.
According to this manufacturing method, not only the particle diameter of the colorant particles contained in the obtained toner is reduced, but also the uniformity of the dispersion state of the particles is increased, so that the color reproducibility of the projected image by OHP is further improved. Get better.

In addition, as long as the configuration of the present invention is adopted, a release agent typified by wax may be contained in the toner together with the binder resin and the colorant.
Known release agents can be used, such as polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbons (paraffin wax, sazol wax, etc.); carbonyl group-containing wax, etc. .
Of these, carbonyl group-containing waxes are preferred. Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18 -Octadecanediol distearate, etc.); polyalkanol esters (trimellitic acid tristearyl, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone).
Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred. The melting point of these release agents is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability. The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

In addition, a charge control agent may be contained in the toner as needed in order to accelerate the toner charge amount and its rise. Here, since a color change occurs when a colored material is used as the charge control agent, a material that is colorless and close to white is preferable.
Any known charge control agent can be used. Examples include triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkyls. Amide, phosphorus simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Bontron P-51 of a quaternary ammonium salt, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex, E-89 of a phenol condensate (above, Orient Chemical Co., Ltd.) Manufactured), TP-302 of quaternary ammonium salt molybdenum complex, TP-1415 (above, manufactured by Hodogaya Chemical Co., Ltd.), copy charge PSY VP2038 of quaternary ammonium salt, copy blue PR of triphenylmethane derivative, Quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (from Hoechst), LRA-901, boron complex LR-147 (Nihon Kalit Ltd), quinacridone, azo pigment, other sulfone Conversion of polymers with functional groups such as acid groups, carboxyl groups, and quaternary ammonium salts Thing, and the like.
In the present invention, the amount of charge control agent used is determined by the toner production method including the type of binder resin, the presence or absence of additives used as necessary, and the dispersion method, and is uniquely limited. However, it is preferably used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents can be dissolved and dispersed after being melt-kneaded with a masterbatch and resin, or may be added when directly dissolving and dispersing in an organic solvent, or may be fixed on the toner surface after preparation of toner particles. Also good.

Further, when the toner composition is dispersed in the aqueous medium during the toner production process, resin fine particles for mainly stabilizing the dispersion may be added.
The resin fine particles used may be any resin that can form an aqueous dispersion, and may be a thermoplastic resin or a thermosetting resin. For example, vinyl resins, polyurethane resins, epoxy resins, polyester resins, Examples thereof include polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, and polycarbonate resin. As the resin fine particles, two or more of the above resins may be used in combination. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained.
The vinyl resin is a polymer obtained by homopolymerization or copolymerization of a vinyl monomer, such as a styrene- (meth) acrylate resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylate polymer, Examples include, but are not limited to, styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene- (meth) acrylic acid copolymers, and the like.

Further, inorganic fine particles can be preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles.
The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m <2> / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
Other polymer fine particles such as polystyrene, methacrylic acid ester and acrylic acid ester copolymer obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, polycondensation systems such as silicone, benzoguanamine, and nylon, and thermosetting resins Examples include polymer particles.
Such a fluidizing agent can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .

  Examples of the cleaning property improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid, such as polymethyl methacrylate fine particles, polystyrene. Examples thereof include fine polymer particles produced by soap-free emulsion polymerization of fine particles and the like. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

By using these toners, a high-quality toner image having excellent development stability can be formed as described above. However, the toner that is not transferred to the transfer medium or intermediate transfer medium by the transfer device and remains on the photosensitive member passes through the toner because it is difficult to remove by the cleaning device due to its fineness and good rolling properties. May end up. In order to completely remove the toner from the image bearing member, it is necessary to strongly press a toner removing member such as a cleaning blade against the photosensitive member. Such a load not only shortens the life of the photoreceptor and the cleaning device, but also uses extra energy.
When the load on the photoconductor is reduced, the toner on the photoconductor and the small-diameter carrier are insufficiently removed, which damages the surface of the photoconductor when passing through the cleaning device and fluctuates the performance of the image forming apparatus. It becomes a factor to make.

As described above, the image forming apparatus of the present invention has an excellent tolerance for fluctuations in the surface state of the photoreceptor, particularly the presence of low-resistance parts, and has a configuration in which fluctuations in charging performance to the photoreceptor are highly suppressed. Therefore, when used in combination with the toner having the above-described configuration, an extremely high quality image can be stably obtained over a long period of time.
In addition, the image forming apparatus of the present invention can be applied not only to the use of the toner having a configuration suitable for obtaining a high-quality image as described above, but also to an irregularly shaped toner by a pulverization method, and the life of the apparatus. Needless to say, it will be greatly extended.

As a material constituting such a pulverized toner, those usually used as an electrophotographic toner can be applied without particular limitation.
Examples of general binder resins used in the toner include homopolymers of styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and the like; styrene / p-chlorostyrene copolymers; Styrene / propylene copolymer, styrene / vinyl toluene copolymer, styrene / vinyl naphthalene copolymer, styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, Styrene / octyl acrylate copolymer, styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / α-chloromethyl methacrylate copolymer, styrene / Acrylonitrile copolymer, styrene / vinyl methyl ketone copolymer, Styrene copolymers such as tylene / butadiene copolymers, styrene / isoprene copolymers, styrene / maleic acid copolymers; polymethyl acrylate, polybutyl acrylate, polymethyl methacrylate, polybutyl methacrylate, etc. Acrylic ester-based homopolymers and copolymers thereof; polyvinyl derivatives such as polyvinyl chloride and polyvinyl acetate; polyester-based polymers, polyurethane-based polymers, polyamide-based polymers, polyimide-based polymers, polyol-based polymers, Examples thereof include an epoxy polymer, a terpene polymer, an aliphatic or alicyclic hydrocarbon resin, an aromatic petroleum resin, and the like. These can be used alone or in combination, but are not particularly limited thereto. Among these, at least one selected from styrene-acrylic copolymer resins, polyester resins, and polyol resins is more preferable from the viewpoint of electrical characteristics, cost, and the like. Furthermore, it is more preferable to use a polyester-based resin and / or a polyol-based resin as having good fixing characteristics.

For the reasons described above, the same resin component as the binder resin of the toner contained in the coating layer of the charging member includes a linear polyester resin composition, a linear polyol resin composition, and a linear styrene acrylic resin. At least one of the compositions or these cross-linked products can be preferably used.
In the toner of the pulverization method, the colorant component, the wax component, the charge control component and the like as described above are mixed with these resin components as necessary, and then kneaded at a temperature close to the melting temperature of the resin component and cooled. Thereafter, a toner may be prepared through a pulverization and classification step, and the above-mentioned external additive components may be appropriately added and mixed as necessary.

It is a schematic sectional drawing of the process cartridge which has a protective agent coating device which concerns on embodiment of this invention. FIG. 3 is a schematic sectional view of a color copying machine as an image forming apparatus including the process cartridge of FIG. 2. It is a block diagram of the protective agent coating device in an Example. It is a figure which shows intensity distribution of the binding energy by XPS analysis of the photoreceptor surface before application | coating of a protective agent. It is a figure which shows the intensity distribution of the binding energy by XPS analysis of the photoreceptor surface after application | coating of a protective agent, (a) is a figure which shows a state with a coverage of 74%, (b) is a figure which shows a state with a coverage of 98%. It is a top view which shows the output state of a halftone image. It is a figure which shows the relationship (IR spectrum) of the wave number and the light absorbency of a photoconductor and the protective agent on this photoconductor. It is a schematic diagram which shows the relationship (IR spectrum) of a wave number and a light absorbency. It is a schematic diagram which shows the relationship (IR spectrum) of a wave number and a light absorbency. It is a schematic diagram which shows the relationship (IR spectrum) of a wave number and a light absorbency. It is a schematic diagram which shows the relationship (IR spectrum) of a wave number and a light absorbency. It is a schematic diagram which shows the relationship (IR spectrum) of a wave number and a light absorbency. It is a schematic diagram which shows the relationship (IR spectrum) of a wave number and a light absorbency.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Protective agent supply part 3 Charging roller 4 Cleaning mechanism 5 Developing device 6 Transfer roller 8 Latent image forming device 12 Process cartridge 20 Protective agent coating device 21 Protective agent bar 22 Protective agent supply member 23 Pressing force applying mechanism 24 Protection Layer forming mechanism 41 Cleaning member 42 Cleaning pressing mechanism 51 Developing roller 52, 53 Agitating and conveying screw 100 Image forming apparatus 104 Paper feeding mechanism L Exposure

Claims (5)

A protective agent application device for applying a protective agent mainly composed of paraffin on the surface of a photoreceptor,
When the index of the amount of the protective agent on the photoconductor is expressed by the following formula (1) and the coverage of the protective agent on the photoconductor is expressed by the following formula (2), when the protective agent is applied for 120 minutes, The protective agent coating apparatus, wherein a ratio (X / Y) of values calculated from the formulas (1) and (2) is 0.020 or less.
X = (index of the amount of protective agent attached) = (Sb / Sa) (1)
Y = (coverage of protective agent) = (A0−A) / A0 × 100 (%) (2)
Here, about Formula (1),
In the ATR (Attenuated Total Reflection) method of the infrared absorption spectrum method, the IR spectrum obtained by measurement under the conditions of Ge as the ATR prism and 45 ° as the incident angle of infrared light, When the spectrum is IR spectrum A (absorbance spectrum) and the IR spectrum of the protective agent alone is IR spectrum B (absorbance spectrum),
Sa does not exist in the IR spectrum B in the IR spectrum (IR spectrum C (absorbance spectrum)) of the photoconductor after 120 minutes of application of the protective agent by the protective agent coating apparatus, and exists in the IR spectrum A 1770 cm −. 1 shows the peak area (Sa) of the peak (peak a) seen in FIG.
Sb is not present in the IR spectrum A and is present in the IR spectrum B in the IR spectrum (IR spectrum C (absorbance spectrum)) of the photoreceptor after 120 minutes of application of the protective agent by the protective agent coating apparatus. 1 shows the peak area (Sb) of the peak (peak b) seen in FIG.
Moreover, about Formula (2),
A0 relates to the C1s spectrum initially obtained by XPS analysis on the surface of the photoreceptor, and the peak obtained by separating the waveform resulting from different bonding states of carbon according to the binding energy is in the range of 290.3 to 294 eV. The ratio of the sum of the areas of peaks having peak tops (total area) to the area of the entire C1s spectrum is shown,
A shows a C1s spectrum obtained by XPS analysis of the surface of the photoconductor after applying the protective agent on the photoconductor for 120 minutes, and shows a waveform generated from different bonding states of carbon according to the binding energy. About the peak obtained by isolate | separating, the ratio with respect to the area of the whole C1s spectrum after the said protective agent application | coating of the sum (total area) of the peak area which has a peak top in the range of 290.3-294 eV is shown. The protective agent coating apparatus according to claim 1,
The protective agent coating apparatus characterized in that the covering ratio Y of the protective agent is 70% or more. In the protective agent coating device according to claim 1 or 2,
The protective agent bar made of the protective agent is scraped off with a brush, and the brush electrostatically flocks 50,000 to 600,000 monofilaments having a diameter of 28 to 42 μm per square inch on a metal core. The paraffin is supplied to the photoconductor by pressing the brush against the photoconductor, and the blade is pressed against the photoconductor to apply the protective agent on the photoconductor. A protective agent applicator characterized by fixing.   A process cartridge integrally comprising at least the photosensitive member and the protective agent coating apparatus according to claim 1.   An image forming apparatus comprising the protective agent coating apparatus according to claim 1.

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