JP4256906B2 - Developing roller and developing device having the same - Google Patents

Description

  The present invention relates to a developing roller that develops using a one-component toner used in an electrophotographic apparatus such as a copying machine, a printer, and a facsimile machine, and a developing apparatus having the developing roller.

  Conventionally, in the field of electrophotographic apparatuses such as copying machines, printers, facsimiles, and particularly small electrophotographic apparatuses, the maintenance has been simplified. For example, the image on the surface of a photoreceptor, photosensitive paper, recording paper, etc. A developing device for developing an electrostatic latent image formed on a carrier using a non-magnetic one-component toner has been put into practical use.

  In this type of developing device, in order to maintain the image quality by preventing the occurrence of background stains and afterimages, and to extend the life of the developing device, (a) the toner charge is made high and uniform; b) preventing toner aggregation and sticking on the toner regulating member surface and the developing roller surface; (c) preventing deterioration due to scratches, cracks, peeling, etc. on the developing roller surface and the toner regulating member surface; d) Prevention of contamination inside the image forming apparatus due to toner leakage and scattering has been a problem. These problems have been partially solved by means such as selection of a material constituting the developing roller and a device structure of the developing device.

  As such a developing roller, the following has been used. (B) a developing roller provided with an elastic layer made of rubber on a metal core, (b) a developing roller provided with a resin coating layer on the elastic layer of the developing roller of (b), and (C) Each of the developing rollers provided with a resin coating layer on a metal core was used. These developing rollers are used corresponding to the structure of the photosensitive member. For example, when a drum photosensitive member is used, the developing roller (b) and the developing roller (b) are used. In the case of using a belt-shaped photoconductor, any of the developing roller (a), the developing roller (b) and the developing roller (c) has been used. And (b) the developing roller or (b) the developing roller is generally used in combination.

However, when using the developing roller (b) and the developing roller (b), so-called elastic developing roller,
1) Control the hardness and electrical resistance appropriately.
2) Low hardness and low surface roughness,
3) The resin coating layer has flexibility, and
4) Setting the firing temperature for heat-curing the coating resin low so as not to deteriorate the rubber of the elastic layer,
There was a problem.

  In recent years, with the development of color in developing devices, it has become necessary to increase the degree of freedom in layout. Therefore, a system using a belt photoreceptor has been adopted. Accordingly, a developing roller having a resin coating layer on the metal core bar (c), a so-called hard developing roller, has been increasingly adopted. When such a hard developing roller is used, the problems 1), 3) and 4) can be solved. However, the toner can be highly charged, the toner can be formed in a uniform thin layer, and the developing roller can be made high. The common problem of making it a lifetime remained.

  In the one-component developing device, as described above, the toner must be highly charged and the toner must be formed in a uniform thin layer. In order to charge the toner at a high level, it is desirable to coat the surface of the developing roller or the surface of the toner regulating member (roller) with a material having a chargeability opposite to that of the toner. As such a material, a resin material made of a polymer compound having a nitrogen element in the main chain or side chain, such as a polyamide resin, a melamine resin, and a guanamine resin exhibiting a positive charging property is effective for a negatively charged toner. Yes (see Patent Documents 1 and 2). However, since it is difficult to make the chemical composition of the resin coating layer on the surface of the developing roller completely uniform, there has been a problem that the amount of charge changes due to the chemical composition of the roller surface changing due to wear over time. . In particular, since the skin layer is formed on the outermost surface of the resin coating layer of the developing roller, the chemical composition change due to wear is steep. Further, along with the recent improvement in image quality, the surface roughness of the developing roller and the protrusions caused by the coating defects of the surface layer appear as image defects, so that extremely strict surface properties of the resin coating layer are required. Therefore, such surface defects are removed by performing removal processing such as tape polishing on the surface of the resin coating layer after resin coating.

  In the elastic developing roller, it is necessary to firmly contact the seal on the resin coating layer in order to prevent toner leakage. However, cracks and peeling may occur in the contacted portion of the seal. A resin coating layer obtained by curing a triazine-based resin such as melamine or guanamine has poor flexibility. Therefore, when such a resin coating layer is formed on an elastic layer, a crack occurs in the resin coating layer within a short time. End up. In particular, in the developing roller, it is necessary to include an electric resistance control agent in the resin coating layer in order to apply a bias voltage. However, if the resistance control agent is included in the resin coating layer, a crack is generated in the resin coating layer. Is accelerated. Therefore, it is difficult for the elastic developing roller to cope with the seal in terms of wear. In the conventional developing device, such an elastic developing roller is used. However, when the developing device after image formation of 10,000 sheets is observed, the seal portion at the end of the elastic developing roller is heavily worn.

Therefore, a developing device has been proposed in which an aluminum sleeve, which is a metal substrate, is used as a developing roller, and an elastic roller whose surface is coated with a material having a chargeability opposite to that of the toner is used as a toner regulating roller. It was. However, this developing device has a problem that the toner holding force and conveying force on the aluminum surface are low. In addition, it has been considered that the surface of the developing roller is roughened to improve the toner transportability, but the surface is smoothed as the number of image formation increases, and therefore, the necessary toner transport amount There was a problem that could not be obtained. Further, the developing roller using the aluminum sleeve as a metal substrate as it is has a problem that the toner holding force is small, so that the image forming apparatus is easily contaminated by scattering.
JP 2000-181218 A JP 2001-34060 A

  The present invention aims to solve this problem.

  That is, the present invention relates to a developing roller for developing with a one-component toner and a developing device having the same, which maintains an appropriate high toner charge amount to prevent the occurrence of afterimages and background stains and has improved durability. The purpose is to provide.

The inventor is a developing roller having a resin coating layer containing ITO as a conductivity imparting member on the surface of a substrate, wherein the resin coating layer is a resin made of a polymer compound having a nitrogen element in the molecular structure. It is composed of a resin containing a low molecular compound having a nitrogen element in the molecular structure, and the elemental composition ratio of carbon element to nitrogen element by X-ray photoelectron spectroscopy analysis of the surface of the resin coating layer In the developing roller in which (N / C) is 0.10 to 0.35, (b) the distribution of the nitrogen element is reduced inward from the surface of the resin coating layer, and (b) the constituent material of the ITO distribution of indium element is found is increased inwardly from the surface of the resin coating layer, and, the skin layer part is a major part of the initial composition change at the surface of (c) the resin coating layer, abrasive Assuming that have been removed by polishing by-loop, and held in proper height toner charge amount while preventing the occurrence of afterimage and scumming, improved durability, and developed using a one-component toner It has been found that a developing roller and a developing device having the developing roller can be provided, and the present invention has been completed.

Specifically, in order to achieve the above object, the invention according to claim 1 is a developing roller having a resin coating layer containing ITO as a conductivity imparting member on the surface of a substrate, wherein the resin coating layer has a molecular structure. X-ray on the surface of the resin coating layer, which is composed of a resin made of a polymer compound having nitrogen element in it, or composed of a resin containing a low molecular compound having nitrogen element in the molecular structure In a developing roller having an elemental composition ratio (N / C) of carbon element to nitrogen element of 0.10 to 0.35 by photoelectron spectroscopy analysis,
(A) The distribution of the nitrogen element is reduced from the surface of the resin coating layer toward the inside,
(B) The distribution of indium element which is a constituent material of the ITO is increased inward from the surface of the resin coating layer, and
(C) A developing roller characterized in that a skin layer portion, which is a portion having a large initial composition change on the surface of the resin coating layer , is removed by polishing with a polishing tape .

In the invention described in claim 2, in the invention described in claim 1, the resin coating layer is a cross-link between a polyester resin having a hydroxyl group in a main chain or a side chain and a triazine resin obtained by etherifying an amino group. It is characterized by comprising a reaction product.

  The invention described in claim 3 is the invention described in claim 1 or 2, wherein the resin coating layer has a surface roughness (Rz) of 4 μm or less, and a protrusion on the surface of the resin coating layer. Is 7 μm or less.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, before polishing with the polishing tape , from the surface of the resin coating layer, a constituent material of ITO is used. Indium is not detected by X-ray photoelectron spectroscopic analysis, and indium, which is a constituent of ITO, is detected from the surface of the resin coating layer after polishing with the polishing tape. is there.

  The invention described in claim 5 includes a developing roller, a toner supply roller that is disposed in contact with the developing roller and supplies toner, and a toner regulating roller that regulates the toner on the developing roller to form a thin layer. The developing device for developing using the one-component toner comprises the developing roller according to any one of claims 1 to 4 as the developing roller.

According to the first aspect of the present invention, 1) since the resin coating layer contains ITO as a conductivity-imparting member, resistance controllability in the developing roller is improved and wear resistance is improved. 2) The resin coating layer is composed of a resin made of a polymer compound having a nitrogen element in the molecular structure, or a resin containing a low molecular compound having a nitrogen element in the molecular structure In addition, since the elemental composition ratio (N / C) of the carbon element to the nitrogen element by the X-ray photoelectron spectroscopic analysis on the surface of the resin coating layer is 0.10 to 0.35, an appropriate high toner charge amount can be obtained. It can be retained to prevent the occurrence of afterimages and background stains, and can be a developing roller that develops using one-component toner with improved durability. 3) The distribution of the nitrogen element is the resin coating layer. From the surface to the inside Is small, the distribution of the indium element is a constituent of the ITO is increased inwardly from the surface of the resin coating layer, and is the major part of the initial composition change at the surface of (c) the resin coating layer Since the skin layer portion has been removed by polishing with an abrasive tape , it is possible to remove the skin layer with a large chemical composition change and to eliminate defects such as protrusions due to painting, Since the agent can be exposed on the surface, it is possible to prevent the image from being changed due to the toner, and to reduce the after-image by reducing the electrical resistance of the surface.

According to the invention described in claim 2, the resin coating layer is composed of a cross-linking reaction product of a polyester resin having a hydroxyl group in the main chain or a side chain and a triazine resin obtained by etherifying an amino group . Therefore, not only the toner chargeability of the resin coating layer can be improved, but also the mechanical properties such as water resistance, solvent resistance, and wear resistance can be improved.

  According to the invention described in claim 3, since the surface roughness (Rz) of the resin coating layer is 4 μm or less and the protrusions on the surface of the resin coating layer are 7 μm or less, The skin layer with a large composition change can be removed, defects such as protrusions due to painting can be removed, and the conductive agent can be exposed on the surface. In addition, afterimages can be prevented by lowering the electrical resistance of the surface.

According to the invention described in claim 4, before polishing with the polishing tape , indium as a constituent material of ITO is not detected by X-ray photoelectron spectroscopy from the surface of the resin coating layer, and After polishing with the polishing tape , indium, which is a constituent material of ITO, is detected from the surface of the resin coating layer. Therefore, the surface of the resin coating layer subjected to polishing with the polishing tape has its electrical resistance. Becomes an electric resistance region where no afterimage is generated.

  According to the invention described in claim 5, a developing roller, a toner supply roller arranged in contact with the developing roller to supply toner, and a toner regulating roller for regulating the toner on the developing roller to form a thin layer In the developing device for developing using the one-component toner comprising the developing roller, the developing roller according to any one of claims 1 to 7 is used as the developing roller, so that the afterimage is maintained at an appropriate high toner charge amount. In addition, it is possible to provide a developing device that develops using a one-component toner that prevents the occurrence of background stains and has improved durability.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a developing roller showing an embodiment of the present invention. FIG. 2 is a sectional view of a developing roller showing another embodiment of the present invention. FIG. 3 is a graph showing the relationship between the depth of the surface layer of the developing roller and the elemental composition ratio (N / C) of the carbon element to the nitrogen element according to one embodiment of the present invention. FIG. 4 is a graph showing the relationship between the depth of the surface layer of the developing roller and the toner charge amount according to the embodiment of the present invention. FIG. 5 is a graph showing the relationship between the N / C of the developing roller and the toner charge amount according to an embodiment of the present invention. FIG. 6 is a graph showing the relationship between the durability of the developing roller and the amount of wear on the surface layer according to an embodiment of the present invention. FIG. 7 is a schematic explanatory view of a developing device using a developing roller showing an embodiment of the present invention.

  In FIG. 1, reference numeral 10 denotes a developing roller. The developing roller 10 has a resin coating layer 4 containing ITO as a conductivity imparting member on the surface of the substrate 3. Thus, when the resin coating layer 4 contains ITO as a conductivity imparting member, resistance controllability in the developing roller is improved and wear resistance is improved. The base 3 is a cored bar made of, for example, a columnar or cylindrical metal. In the present invention, as shown in FIG. 2, the base 3 in the developing roller 20 may have an elastic layer 2 on the surface of the core metal 1. As the elastic layer 2, for example, rubber or elastomer such as ethylene propylene rubber, butadiene rubber, nitrile rubber, styrene rubber, isoprene rubber, silicone rubber, urethane rubber, urethane foam, or the like can be used. The resin coating layer 4 is composed of a resin made of a polymer compound having a nitrogen element in the molecular structure, or a resin containing a low molecular compound having a nitrogen element in the molecular structure. Since such a resin containing a nitrogen element is a positively charged material, the toner can be negatively charged. The resin coating layer 4 is formed, for example, by coating by means such as dipping, spray coating, roller coating, or by coating a molded product formed into a tube shape.

  In the developing roller 10 (20) of the present invention, the elemental composition ratio (N / C) of the carbon element to the nitrogen element by X-ray photoelectron spectroscopy analysis on the surface of the resin coating layer 4 is 0.10 to 0.35. is there. The “element composition ratio” is also called “atomic ratio”. When the elemental composition ratio (N / C) of the carbon element to the nitrogen element by X-ray photoelectron spectroscopic analysis on the surface of the resin coating layer 4 is less than 0.10, the toner cannot be highly charged. When the elemental composition ratio (N / C) of the carbon element to the nitrogen element by the X-ray photoelectron spectroscopic analysis on the surface of the resin coating layer 4 exceeds 0.35, the reverse charge of the toner is formed on the developing roller 10 (20). Since it remains, an afterimage is generated. However, as described above, in the developing roller 10 (20) of the present invention, the elemental composition ratio (N / C) of the carbon element to the nitrogen element by X-ray photoelectron spectroscopy analysis on the surface of the resin coating layer 4 is 0.10 to 0. Therefore, it is possible to provide a developing roller that develops using a one-component toner that is maintained at an appropriate high toner charge amount to prevent the occurrence of afterimages and background stains and has improved durability.

Resins comprising a polymer compound having a nitrogen element in the molecular structure include, for example, triazine resins such as melamine, guanamine, and guanamine derivatives, polyamide, polyimide, polyamine, polyimine, polyacrylamide, polyacrylimide, polyethyleneamine, polyethylene Imine, polyallylamine, aminopolyacrylamide, polyamideimide, polyetherimide, polyoxyethylene alkylamine, urea resin, amino acid resin, polyacrylonitrile, polyurethane, and mixtures of these resins, or these resins and other resins Preferably, it is a crosslinking reaction product of a polyester resin having a hydroxyl group in the main chain or side chain and a triazine resin obtained by etherifying an amino group. Triazine-based resins such as melamine, guanamine, and guanamine derivatives contain amino groups, and thus have a reverse polarity with respect to negatively charged toner. Therefore, such a triazine resin, since amino groups loaded onto the triazine ring does not act as a curing agent in the form of -NH _2, by changing the etherified structure -NH (CH ₂ OR) A crosslinked structure is formed by a condensation crosslinking reaction between the generated ether group and the hydroxyl group of the base resin.

In the developing roller 10 (20) of the present invention, (b) the distribution of the nitrogen element is reduced inward from the surface of the resin coating layer 4, and (b) the distribution of the indium element that is a constituent material of the ITO. Is increased inward from the surface of the resin coating layer 4 and (c) the skin layer portion, which is a large portion of the initial composition change on the surface of the resin coating layer , is removed by polishing with an abrasive tape. ing. As described above, (a) the distribution of the nitrogen element is reduced from the surface of the resin coating layer 4 toward the inside, and (b) the distribution of the indium element that is a constituent material of the ITO is reduced in the resin coating layer 4. The chemical composition is increased when the skin layer portion which is increased inward from the surface and (c) the skin layer portion which is a large portion of the initial composition change on the surface of the resin coating layer is removed by polishing processing with an abrasive tape. It is possible to remove skin layers with large changes, remove defects such as protrusions due to painting, and expose the conductive agent to the surface, so that the image of the image due to changes in characteristics such as toner charge amount can be removed. A change can be prevented, and an afterimage can be prevented by lowering the electrical resistance of the surface.

  Further, when the developing roller 10 (20) having the above-described configurations (a) to (c) is mounted on a commonly used developing device (see FIG. 7), the N / C after 150 k printing of the developing roller is completed. It can be seen that the ratio is 0.1 or more, and the In / C ratio of the developing roller after completion of 150k printing is 0.01 or more, and it is difficult for afterimages and background staining to occur.

  In the present invention, the resin constituting the resin coating layer 4 is preferably a cross-linking reaction product of a polyester resin having a hydroxyl group in the main chain or side chain and a triazine resin obtained by etherifying an amino group. Thus, when the resin constituting the resin coating layer 4 is a cross-linking reaction product of a polyester resin having a hydroxyl group in the main chain or side chain and a triazine resin obtained by etherifying an amino group, the resin coating layer 4 In addition to improving the toner chargeability, the mechanical properties such as water resistance, solvent resistance, and wear resistance can be improved.

  Examples of the low molecular compound having nitrogen in the molecular structure include imidazole, 2-methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1- Benzyl-2-methylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methyl Imidazole, 1-aminoethyl-2-methylimidazole, 1-aminoethyl-2-methylimidazole, 1- (cyanoethylaminoethyl) -2-methylimidazole, N- [2- (2-methyl-1-imidazolyl) ]] Urea, 1-cyanoethyl- -Undecylimidazole, 1-cyanoethyl-2-methylimidazole trimellitate, 1-cyanoethyl-2-ethyl-4-methylimidazole trimellitate, 1-cyanoethyl-2-undecylimidazole trimellitate, 2,4- Diamino-6- [2-methyl-1-imidazolyl] -ethyl-1,3,5-triazine, 2,4-diamino-6- (2-undecyl-1-imidazolylethyl) -1,3,5-triazine 2,4-diamino-6- [2-ethyl-4-methyl-1-imidazolylethyl] -1,3,5-triazine, 1-dodecyl-2-methyl-3-benzylimidazolium crawleride, N, N′bis (2-methyl-1-imidazolylethyl) urea, N, N ′-(2-methyl-1-imidazolylethyl) -azi Amide, 2,4-dialkylimidazole-5-dithiocarboxylic acid, 1,3-dibenzyl-2-methylimidazolium crawleride, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5 -Bis (hydroxylmethyl) imidazole, 1-cyanoethyl-2-phenyl-4,5-bis (cyanoethoxymethyl) imidazole, 2-methylimidazole / isocyanuric acid adduct, 2-phenylimidazole / isocyanuric acid adduct, 2, 4-diamino-6- [2-methyl-1-imidazolylethyl] -1,3,5-triazine isocyanuric acid adduct, 2-alkyl-4-formylimidazole, 2,4-dialkyl-5-phor Milimidazole, 2,4,6-carboxyphenyl-1,3,5-to It is a derivative of imidazole or triazine such as lyazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4,6-triamino-1,3,5-triazine. Unless it is contrary to the object of the present invention, low molecular compounds having nitrogen other than these compounds in the molecular structure may be used.

  The surface roughness (Rz) of the resin coating layer 4 is preferably 4 μm or less, and the protrusion on the surface of the resin coating layer 4 is preferably 7 μm or less. Thus, when the surface roughness (Rz) of the resin coating layer 4 is 4 μm or less and the protrusions on the surface of the resin coating layer 4 are 7 μm or less, the surface of the resin coating layer 4 over time. Even if it is worn, the change in the toner conveyance amount is small, the dot reproducibility of the image (no omissions) is good, and white spots due to protrusions do not occur in the image.

In the developing roller 10 (20) of the present invention, before polishing with the polishing tape , indium, which is a constituent material of ITO, is not detected from the surface of the resin coating layer 4 by X-ray photoelectron spectroscopy, and After polishing with the polishing tape , indium, which is a constituent material of ITO, is detected from the surface of the resin coating layer 4. The ITO is inclined in the resin coating layer 4 as the diluted solvent evaporates after coating and sinks in the direction of the core metal . Therefore, ITO is not exposed in the skin layer of the resin coating layer 4. As a result, the surface of the resin coating layer 4 without polishing has a high electric resistance, and charges having a polarity opposite to that of the developed toner remain on the roller surface after development, and the charges are not removed, and thus an afterimage is likely to occur. Become. However, when the resin coating layer 4 is polished by the polishing tape , the ITO is exposed, so that the surface of the resin coating layer 4 becomes an electric resistance region where the electric resistance is lowered and no afterimage is generated.

  As shown in FIG. 7, the developing device of the present invention regulates the developing roller 10, the toner supply roller 102 that is disposed in contact with the developing roller 10 and supplies the toner 107, and the toner 107 on the developing roller 10. A developing device that develops using a one-component toner including a toner regulating roller 104 that forms a thin layer, and has the developing roller according to claim 1 as the developing roller 10. Yes. In FIG. 7, 103 is a toner conveying member, 105 is a case, and 106 is a spring. As described above, when the developing device of the present invention has the developing roller according to any one of the first to fourth aspects, the image is maintained at an appropriate high toner charge amount to prevent the occurrence of an afterimage and a background stain. In addition, it is possible to provide a developing device that develops using one-component toner with improved durability.

  In order to operate the developing device of the present invention, the toner regulating roller 104 is not rotated during non-development, but the developing roller 10 is rotated in the direction opposite to the rotation during image formation. In this way, the toner deposited on the wedge portion between the developing roller 10 and the toner regulating roller 104 is once pushed back to the upstream side during non-development. Specifically, if the toner regulating roller 104 is provided with a one-way clutch (not shown) and the toner regulating roller 104 is operated only when the developing roller 10 rotates in the reverse direction, the toner regulating roller 104 and the developing roller 10 are operated. The toner regulating roller 104 can be rotated only by the frictional resistance of the surface. The same effect can be obtained even if the toner regulating roller 104 is forcibly driven in the same direction, but the developing device becomes complicated, and side effects such as banding may occur depending on the configuration of the gear. , You need to be careful. In order to rotate the toner restricting roller 104 only by the frictional resistance between the toner restricting roller 104 and the developing roller 10, the larger the static friction coefficient between the developing roller 10 and the toner restricting roller 104, the easier the rotation. However, if this friction coefficient is too large, the frictional resistance between the developing roller 10 and the toner regulating roller 104 is increased even during image formation, and heat is generated due to friction, so that the toner at the contact portion is likely to be welded. Therefore, it is considered necessary to make the frictional resistance during non-development greater than during image formation.

Example 1
A polyester resin and a melamine resin were blended at a solid content ratio of 7: 3, and ITO conductive particles were blended therein to prepare a paint. This paint was spray-coated on a φ26 mm aluminum roller and baked at 160 ° C. for 1 hour to form a resin coating layer of about 10 μm on the surface of the aluminum roller. Then, the surface roughness (Rz) is 1.4 to 2.1 μm by polishing the surface of the resin coating layer to a thickness of about 0.05 m using a # 1000 polishing tape (abrasive: SiC). A developing roller having a smooth surface was obtained.

  The chemical composition of the resin coating layer of the developing roller thus obtained was measured by the following measurement method using X-ray photoelectron spectroscopy (XPS).

[Measuring method]
Measuring device: Composite surface analyzer PHI ESCA-5600
X-ray source: Mg-kα ray (1253.6 eV)
Measurement depth: about 4nm Ellipse Neutralizing gun: Used

  The measurement results of the chemical composition of the resin coating layer of the developing roller, that is, 1) the relationship between the surface layer depth of the developing roller and the elemental composition ratio (N / C) of the carbon element to the nitrogen element, and 2) the developing roller The relationship between the depth of the surface layer and the toner charge amount, and 3) the relationship between the N / C of the developing roller and the toner charge amount are shown in FIGS. 3, 4 and 5, respectively.

  In addition, the durability test was performed in a cycle in which the developing roller was idled for 1 minute, and then the reverse operation was performed for 0.1 second and then rested for 10 seconds. The process speed was equivalent to 20 sheets of A4 paper / minute. The number of durable sheets was converted by the calculation of (empty turning time) / (20 sheets / minute). The durability target was 150k. The durability test result of the resin coating layer of the developing roller is shown in FIG.

  The initial change (0 → 0.05 μm) in FIG. 2 is a change when the surface of the resin coating layer after resin coating is polished by tape polishing. The initial chemical composition change is very large. For this reason, removing a portion where the change is large in advance can prevent a large change with time. Further, when the toner charge amount is too high, the reverse charge of the toner remains on the surface of the resin coating layer, and an afterimage is generated. Furthermore, since the conductive agent is not exposed on the surface of the resin coating layer that is not subjected to tape polishing, the resistance is high as shown in the following Table 1, and an afterimage is generated. In Table 1, In (indium) is an element derived from ITO which is a conductive agent. The resistance is a value of an applied voltage of 30V.

The following can be seen from FIG. That is, as the presence of nitrogen element decreases as it goes into the surface layer, the toner charge amount tends to decrease, and the resin coating layer is worn by about 2 μm and the N / C ratio is 0.1. If the value is less than 1, the toner charge amount is less than −10 nC / cm ² , and the background stain is likely to occur.

It is sectional drawing of the developing roller which shows one embodiment of this invention. It is sectional drawing of the developing roller which shows other one Embodiment of this invention. 6 is a graph showing the relationship between the depth of the surface layer of the developing roller and the elemental composition ratio (N / C) of the carbon element to the nitrogen element according to an embodiment of the present invention. 6 is a graph showing the relationship between the depth of the surface layer of the developing roller and the toner charge amount according to an embodiment of the present invention. 6 is a graph showing the relationship between the N / C of the developing roller and the toner charge amount according to an embodiment of the present invention. It is a graph which shows the relationship between the durable sheet number of the developing roller which shows one embodiment of this invention, and the abrasion loss of a surface layer. It is a schematic explanatory drawing of the developing device using the developing roller which shows one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core metal 2 Elastic layer 3 Base | substrate 4 Resin coating layer 10,20 Developing roller 102 Toner supply roller 104 Toner control roller

Claims (5)

A developing roller having a resin coating layer containing ITO as a conductivity imparting member on the surface of the substrate, wherein the resin coating layer is composed of a resin made of a polymer compound having a nitrogen element in the molecular structure, Alternatively, it is composed of a resin containing a low molecular compound having nitrogen element in the molecular structure, and the element composition ratio (N / C) of carbon element to nitrogen element by X-ray photoelectron spectroscopy analysis on the surface of the resin coating layer In a developing roller having a 0.10 to 0.35,
(A) The distribution of the nitrogen element is reduced from the surface of the resin coating layer toward the inside,
(B) The distribution of indium element which is a constituent material of the ITO is increased inward from the surface of the resin coating layer, and
(C) A developing roller , wherein a skin layer portion, which is a portion having a large initial composition change on the surface of the resin coating layer , is removed by polishing with a polishing tape . 2. The development according to claim 1, wherein the resin coating layer is composed of a crosslinking reaction product of a polyester resin having a hydroxyl group in a main chain or a side chain and a triazine resin obtained by etherifying an amino group. roller.   The developing roller according to claim 1, wherein a surface roughness (Rz) of the resin coating layer is 4 μm or less, and a protrusion on the surface of the resin coating layer is 7 μm or less. Before polishing with the polishing tape , indium, which is a constituent of ITO, is not detected from the surface of the resin coating layer by X-ray photoelectron spectroscopy, and after polishing with the polishing tape , the resin coating The developing roller according to claim 1, wherein indium, which is a constituent material of ITO, is detected from the surface of the layer.   Development that develops using one-component toner comprising a developing roller, a toner supply roller that is disposed in contact with the developing roller and supplies toner, and a toner regulating roller that regulates the toner on the developing roller to form a thin layer 5. A developing apparatus comprising the developing roller according to claim 1 as the developing roller.

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