JP5470902B2 - Photoconductor evaluation method - Google Patents

Description

  The present invention relates to a method for evaluating a photoreceptor.

  Various materials are recycled from the viewpoint of effective use of resources. In the field of image forming apparatuses, the recycling of photoreceptors has attracted attention. The photoreceptor is generally produced by laminating a photosensitive layer on an aluminum drum, and is incorporated in a process cartridge or a photoreceptor unit.

  The process cartridge has been replaced and discarded when the entire amount of toner has been consumed. This follows the trend of the time when the life of the photoconductor was not sufficient, especially when a photoconductor having a surface protective layer is used, or when an image is printed while applying a lubricant to the photoconductor. In the case of forming the photoconductor, the photoconductor incorporated in the replaced process cartridge often maintains sufficient performance.

  For this reason, currently, process cartridges that can be used for a long period of time while supplying toner are mainstream. However, each time a predetermined image is formed or when an abnormal image is formed, the process cartridge is used. Exchanged. Also in this case, the photoconductor incorporated in the replaced process cartridge often maintains a sufficient performance. Further, by cleaning the photoconductor incorporated in the replaced process cartridge, a photoconductor having no problem in performance may be obtained.

  Therefore, after cleaning the process cartridge collected from the market or the photoconductor taken out from the photoconductor unit, the appearance is inspected visually or by a machine to check whether there is any defect and recycled. However, an abnormal image may be formed on the photoreceptor having no problem in appearance. For example, a photoconductor to which silica having a refractive index close to that of the photoconductor adheres adsorbs an ionic substance generated by charging or the like, and the surface resistance is lowered, resulting in image blur. For this reason, a photoreceptor having no problem in appearance is incorporated into a process cartridge or a photoreceptor unit to form an image, and it is confirmed that no abnormal image is formed, and is recycled. However, in general, an image forming apparatus that confirms that no abnormal image is formed is not a user's image forming apparatus. Therefore, after removing the photoconductor from the image forming apparatus, the toner or the like attached to the photoconductor is removed. It needs to be cleaned again.

  Therefore, a method for evaluating a photoconductor without forming an image is desired. Patent Document 1 discloses a method for evaluating the occurrence of filming by irradiating an electrophotographic photoreceptor with ultraviolet rays having a wavelength of 200 nm to 420 nm and measuring fluorescence emitted from the photoreceptor. Using this method, the occurrence of filming can be evaluated, but depending on the substance attached to the photoconductor, there are substances that cause recycling problems due to a small amount of adhesion. Some substances do not cause problems. Therefore, in order to accurately determine whether or not the photoconductor can be used, it is necessary to analyze the adhesion amount according to the substance adhering to the photoconductor.

The present invention aims at providing the prior art in view of the problems with the method of evaluating the photoreceptor capable of determining whether a sensing the light can be used accurately.

According to one aspect of the present invention, a method for evaluating the photoconductor used in the image forming apparatus having a means for supplying a lubricant to the photoreceptor, a step of cleaning the photoreceptor, which is the cleaning Measuring the ATR-IR spectrum of the photoreceptor, the ratio of the area of the peak from silica to the area of the peak from the cleaned photoreceptor in the ATR-IR spectrum, and the ATR-IR spectrum calculating a ratio of the area of the peak attributable to the lubricant to the area of a peak derived from the cleaned photosensitive member, the cleaned photosensitive body, a step of determining whether it is possible to use a, the peak derived from the silica to the area of a peak derived from the cleaned photosensitive member of the ATR-IR spectrum With the ratio of the product is less than 0.20, when the ratio of the peak area of that from the lubricant to the area of a peak derived from the cleaned photosensitive member of the ATR-IR spectrum is less than 0.70 In addition, it is determined that the cleaned photoreceptor can be used, and the photoreceptor has a surface layer containing polycarbonate, and the lubricant contains zinc stearate and zinc palmitate. The peak derived from the photoconductor is a carbonate group peak, the peak derived from the silica is a Si-O bond peak, and the peak derived from the lubricant is a zinc ion and a carboxylate ion. It is the peak of the coupling | bond part of (1 ).

According to a second aspect of the invention, a method for evaluating the photoconductor used in the image forming apparatus having a means for supplying a lubricant to the photoreceptor, a step of cleaning the photoreceptor, which is the cleaning A process for measuring the ATR-IR spectrum of the photoconductor, and the ATR-IR spectrum and the photoconductor used in the image forming apparatus on the basis of the peak derived from the cleaned photoconductor of the ATR-IR spectrum Obtaining a difference spectrum of a new ATR-IR spectrum of the ATR-IR spectrum, a ratio of a peak area derived from silica of the difference spectrum to an area of a peak derived from the cleaned photoreceptor of the ATR-IR spectrum, and the difference with respect to the peak area derived from the cleaned photosensitive member of the ATR-IR spectrum spectrum Calculating a ratio of the area of the peak attributable to the lubricant, the cleaned photosensitive member has a step of determining whether it is possible to use, it has been cleaned of the ATR-IR spectrum The ratio of the peak area derived from silica in the difference spectrum to the area of the peak derived from the photoreceptor is less than 0.20 , and the ratio of the peak area derived from the cleaned photoreceptor in the ATR-IR spectrum. When the ratio of the peak areas derived from the lubricant in the difference spectrum is less than 0.70 , the cleaned photoreceptor is determined to be usable, and the photoreceptor is a surface containing polycarbonate. A layer formed, and the lubricant contains zinc stearate and zinc palmitate and has a peak derived from the photoreceptor. Is the peak of the carbonate group, a peak derived from the silica is the peak of the Si-O bond, wherein the peaks derived from the lubricant, the peak of the binding portion of the zinc ion and carboxylate ion And

According to a third aspect of the present invention, in the method for evaluating a photoconductor according to the first or second aspect , the lubricant is a mixture of zinc stearate and zinc palmitate.

According to a fourth aspect of the present invention, in the method for evaluating a photosensitive member according to any one of the first to third aspects, a Ge prism is used as the ATR prism when the ATR-IR spectrum is measured, The incident angle of external light is 30 ° or more and 60 ° or less.

According to the present invention can provide a method for evaluating capable photoreceptor determining whether sensitive phosphors can be used accurately.

1 is a cross-sectional view illustrating an example of an image forming apparatus in which a photoconductor to be evaluated is incorporated. FIG. 3 is a diagram showing an ATR-IR spectrum at a measurement point 1 of the photosensitive drum 1. 3 is a diagram showing a new ATR-IR spectrum of the photosensitive drum used in Example 1. FIG.

  Next, the form for implementing this invention is demonstrated with drawing.

  The present inventors analyzed the ATR-IR spectrum of the collected photoconductor in order to investigate an evaluation method for determining whether or not the photoconductor collected for recycling can be used. It was found that toner, silica, and lubricant were mainly attached. Further, ATR-IR measurement and image formation were performed on the photoconductors in various states, and the substances adhering to the photoconductor and the influence of the adhesion amount on the image formation were examined. As a result, it has been found that the amount of toner, silica, and lubricant adhering to the photoreceptor starts to affect the image formation differs depending on each substance.

  Next, the present inventors examined whether the adhesion amount at which the toner, silica, and lubricant start to affect image formation can be estimated by ATR-IR measurement of the collected photoreceptor. As a result, using the area of the peak derived from the toner, silica, and lubricant in the ATR-IR spectrum as an index, the value of the index that begins to affect image formation is estimated to determine whether the photoconductor can be used. As a result, it was found that it was used as an index when performing the present invention.

  That is, the method for evaluating a photoconductor of the present invention includes a step of cleaning a photoconductor, a step of measuring an ATR-IR spectrum of the cleaned photoconductor, and a peak area derived from the photoconductor of the ATR-IR spectrum. The step of calculating the ratio of the area of the peak derived from silica and the ratio of the area of the peak derived from the lubricant to the area of the peak derived from the photoreceptor in the ATR-IR spectrum and the cleaned photoreceptor are used. Determining whether it is possible. The ratio of the area of the peak derived from silica to the area of the peak derived from the photoconductor of the ATR-IR spectrum is less than a predetermined value, and the lubricant for the area of the peak derived from the photoconductor of the ATR-IR spectrum When the ratio of the peak areas derived from is less than a predetermined value, it is determined that the cleaned photoreceptor can be used.

  The peak derived from the photoreceptor is not particularly limited as long as the overlap with the peak derived from the toner, silica, or lubricant is small, but includes a carbonate group peak.

  In the case where the photoreceptor has absorption in a region where a peak derived from silica and / or a peak derived from a lubricant exists, the peak derived from the photoreceptor in the ATR-IR spectrum of the cleaned photoreceptor is used as a reference. It is preferable to obtain a difference spectrum between the ATR-IR spectrum of the cleaned photoconductor and the new ATR-IR spectrum of the photoconductor. In this case, instead of the area of the peak derived from the silica and / or the peak derived from the lubricant in the ATR-IR spectrum of the cleaned photoreceptor, the area and / or lubrication of the peak derived from the silica in the difference spectrum. The area of the peak derived from the agent is used. The new ATR-IR spectrum of the photoconductor is measured under the same conditions as the ATR-IR spectrum of the cleaned photoconductor, and is the average of the new ATR-IR spectra of a plurality of photoconductors. Also good.

  The lubricant is not particularly limited, but a lubricant containing zinc stearate and zinc palmitate is preferable. At this time, the content of zinc stearate and zinc palmitate in the lubricant is preferably 55 to 100% by mass. Moreover, the mass ratio of zinc stearate and zinc palmitate is usually 75:25 to 40:60, preferably 66:34 to 40:60.

  The lubricant preferably further contains boron nitride together with zinc stearate and zinc palmitate. Thereby, since boron nitride self-lubricates, abrasion of the blade 24a can be suppressed.

  The amount of boron nitride used is usually 2-30%, preferably 4-25%, more preferably 6-20%, based on the total mass of zinc stearate and zinc palmitate. When the amount of boron nitride used is less than 2%, the effect of adding boron nitride may be insufficient. When it exceeds 30%, boron nitride is deposited on the photoconductor 10, and white spots are abnormal. An image may be generated easily.

  The lubricant may further contain alumina together with zinc stearate, zinc palmitate and boron nitride. Thereby, the lubricant applied excessively on the photoreceptor 10 can be polished.

  The amount of alumina used is usually 2 to 15%, preferably 3 to 10%, more preferably 4 to 8%, based on the total mass of zinc stearate and zinc palmitate. If the amount of alumina used is less than 2%, the effect of adding alumina may be insufficient, and if it exceeds 15%, alumina may easily damage the photoconductor 10.

  The average particle diameter of alumina is usually 0.05 to 0.5 μm, preferably 0.1 to 0.4 μm, and more preferably 0.2 to 0.3 μm. If the average particle size of alumina is less than 0.05 μm, the effect of adding alumina may be insufficient, and if it exceeds 0.5 μm, alumina may easily damage the photoreceptor.

  Hereinafter, a method for evaluating a photoreceptor on which a surface layer containing polycarbonate is formed will be described. At this time, since the photoconductor on which the surface layer is formed has a long life, there is a high possibility that it can be used.

  The photoreceptor to be evaluated is not particularly limited, and examples include a process cartridge collected from the market and a photoreceptor taken out from the photoreceptor unit. The process cartridge and the photoreceptor unit have means for supplying a lubricant containing zinc stearate and zinc palmitate to the photoreceptor, and the lubricant is supplied to the photoreceptor when forming an image. For this reason, toner, silica, and lubricant are mainly attached to the photoreceptor to be evaluated.

  The photoreceptor to be evaluated is first cleaned by removing deposits with air, cloth or the like. In cleaning, a solvent that does not dissolve or swell the photoreceptor such as water or ethanol may be used. Further, it is preferable that the cleaned photoreceptor is visually inspected and visually inspected to measure the ATR-IR spectrum of the photoreceptor free from scratches, dents, distortions and the like.

  Next, from the ATR-IR spectrum of the cleaned photoconductor, the ratio of the peak area Sa derived from silica to the peak area Sp derived from the photoconductor (hereinafter referred to as silica index) and the photoconductor. A ratio of the peak area Sb derived from the lubricant to the peak area Sp (hereinafter referred to as a lubricant index) is calculated. At this time, since the photoconductor has absorption in a region where a peak derived from silica and a peak derived from the lubricant exist, cleaning is performed on the basis of the peak derived from the photoconductor of the ATR-IR spectrum of the cleaned photoconductor. A difference spectrum between the ATR-IR spectrum of the photoreceptor and the new ATR-IR spectrum of the photoreceptor is obtained. And the area of the peak derived from the silica of the difference spectrum and the area of the peak derived from the lubricant are used as Sa and Sb, respectively.

  As a result, when the silica index is less than 0.20 and the lubricant index is less than 0.70, it is determined that the cleaned photoreceptor can be used. Photoconductors determined to be usable can be reused by being incorporated into a process cartridge or a photoconductor unit. When the silica index is 0.20 or more, an abnormality occurs in the output image due to silica on the photoreceptor soon after use. Further, if the lubricant index is 0.70 or more, image blurring occurs due to the lubricant soon after use, or silica is taken into the lubricant and fixed on the photoreceptor.

  Table 1 shows the peak and background ranges when calculating Sa, Sb, and Sp.

このとき、Ｓａを算出する際のピークは、Ｓｉ−Ｏ結合のピークであり、Ｓｂを算出する際のピークは、Ｚｎ^２＋とＲＣＯＯ⁻の結合部分のピークであり、Ｓｐを算出する際のピークは、カーボネート基のピークである。

At this time, the peak when calculating Sa is the peak of Si—O bond, the peak when calculating Sb is the peak of the bond portion of Zn ²⁺ and RCOO ⁻ , and the peak when calculating Sp Is the peak of the carbonate group.

  Sa, Sb, and Sp can be measured at arbitrary points on the surface of the photoreceptor, respectively. However, when evaluating a drum-shaped photoreceptor, values of 3 to 15 points measured in the longitudinal direction of the photoreceptor are measured. An average value is preferred. At this time, since the amount of silica or lubricant adhering in the circumferential direction of the photoconductor is considered to be substantially constant, the distance between the both ends of the image output region in the longitudinal direction of the photoconductor is set to 2 By measuring three points that are equally divided, it is possible to allow variations in the adhesion amount of silica and lubricant in the longitudinal direction of the photoreceptor. In addition, although the one where there are many measurement points can evaluate the dispersion | variation in the adhesion amount of a silica or a lubricant, when a measurement point exceeds 15 points, measurement time and analysis time will become long.

  When measuring the ATR-IR spectrum of the cleaned photoreceptor, a Ge prism is preferably used as the ATR prism, and the incident angle of infrared light is preferably 30 to 60 °. Thereby, the balance between the thickness of the silica and the lubricant adhering to the photoconductor and the depth at which the infrared light penetrates into the sample becomes good, and the measurement accuracy of Sa, Sb and Sp can be improved.

  The reason why the peak area derived from the toner is not measured is that when the toner is attached to the photoreceptor, it can be visually confirmed. In the case where it is difficult to visually confirm the toner, the ratio of the peak area derived from the toner to the toner index, that is, the peak area derived from the photoreceptor in the ATR-IR spectrum, is the same as the silica index and the lubricant index. May be further calculated. In this case, when the toner index is less than a predetermined value in addition to the silica index and the lubricant index, it is determined that the cleaned photoreceptor can be used.

  As described above, the case where the photoconductor on which the surface layer containing polycarbonate is formed is evaluated has been described. However, when the photoconductor on which the surface layer containing polycarbonate is not formed is evaluated, as a peak derived from the photoconductor The peak of the component contained in the vicinity of the surface of the photoconductor is used so as not to overlap with the peak of the toner, silica or lubricant.

  Next, the photoreceptor to be evaluated will be described.

  The shape, structure, size and the like of the photoreceptor are not particularly limited, but the shape is preferably a drum shape. The material of the photoreceptor is not particularly limited, and examples thereof include azo-based and phthalocyanine-based organic photoreceptors. Organic photoreceptors are cheaper to manufacture than inorganic photoreceptors and are widely used in process cartridges and photoreceptor units.

  In the photoreceptor, at least a photosensitive layer is formed on a conductive support, and other layers are further formed as necessary. As the photosensitive layer, 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 formed on the charge generation layer, or a charge generation layer is formed on the charge transport layer. The opposite layer type is mentioned. Further, a surface layer may be formed on the photosensitive layer in order to improve the mechanical strength, abrasion resistance, gas resistance, cleaning property, etc. of the photoreceptor. Furthermore, an undercoat layer may be further formed between the photosensitive layer and the conductive support. Moreover, each layer may contain a plasticizer, antioxidant, a leveling agent, etc. as needed.

Although it does not specifically limit as an electroconductive support body, Metals, such as aluminum, nickel, chromium, nichrome, copper, gold | metal | money, silver, platinum, whose volume specific resistance is 10 < ¹⁰ > ohm * cm or less, tin oxide, indium oxide, etc. Metal oxide coated with film or cylindrical plastic or paper by vapor deposition or sputtering; aluminum, aluminum alloy, nickel, stainless steel, etc .; these plates are formed into drums by extruding and drawing. Examples of the tube include a tube subjected to surface treatment such as cutting, superfinishing, and polishing after being formed into a blank.

  The diameter of the drum-shaped conductive support is usually 20 to 150 mm, preferably 24 to 100 mm, and more preferably 28 to 70 mm. If the diameter is less than 20 mm, it becomes physically difficult to arrange the charging means, the exposure means, the developing means, the transfer means, and the cleaning means around the drum-shaped photoconductor. The device becomes larger. In particular, when the image forming apparatus is a tandem type, it is necessary to mount a plurality of photoconductors. Therefore, the diameter of the drum-shaped conductive support is usually 70 mm or less, and preferably 60 mm or less.

  As the conductive support, an endless nickel belt or an endless stainless steel belt can also be used.

  Examples of the undercoat layer include a resin or a white pigment and a resin as a main component, and a metal oxide obtained by chemically or electrochemically oxidizing the surface of a conductive support. What is made into a component is preferable. Examples of the white pigment include metal oxides such as titanium oxide, aluminum oxide, zirconium oxide, and zinc oxide. Among these, titanium oxide is preferable because charge injection from the conductive support can be suppressed. Examples of the resin include thermoplastic resins such as polyamide, polyvinyl alcohol, casein, and methyl cellulose, thermosetting resins such as acrylic resin, phenol resin, melamine resin, alkyd resin, unsaturated polyester, and epoxy resin. You may use together. The undercoat layer may be a single layer, or a plurality of layers may be laminated.

  The charge generation material is not particularly limited, but azo pigments such as monoazo pigments, bisazo pigments, trisazo pigments, tetrakisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthene dyes, cyanine Organic dyes, styryl dyes, pyrylium dyes, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indanthrone pigments, squarylium pigments, phthalocyanine pigments, etc. Pigments and dyes; inorganic materials such as selenium, selenium-arsenic, selenium-tellurium, cadmium sulfide, zinc oxide, titanium oxide, and amorphous silicon may be used, and two or more of them may be used in combination.

  Although it does not specifically limit as a charge transport material, Anthracene derivative, pyrene derivative, carbazole derivative, tetrazole derivative, metallocene derivative, phenothiazine derivative, pyrazoline compound, hydrazone compound, styryl compound, styryl hydrazone compound, enamine compound, butadiene compound, distyryl compound , An oxazole compound, an oxadiazole compound, a thiazole compound, an imidazole compound, a triphenylamine derivative, a phenylenediamine derivative, an aminostilbene derivative, a triphenylmethane derivative, and the like.

  The resin that can be used to form the charge generation layer, the charge transport layer, or the photosensitive layer is not particularly limited as long as it is insulative, but polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer Polymer, 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 Thermoplastic resins such as polyethersulfone and ABS resin; thermosetting resins such as phenol resin, epoxy resin, urethane resin, melamine resin, isocyanate resin, alkyd resin, silicone resin, thermosetting acrylic resin; polyvinyl carbazole, polyvinyl Anthracene, Photoconductive resins such as Ribinirupiren. These may be used alone or in combination.

  The surface layer is not particularly limited, and examples thereof include a resin having a mechanical strength higher than that of the photosensitive layer and a resin in which an inorganic filler is dispersed. The surface layer may not have charge transport capability when the film thickness is small, but when the film thickness is large, the sensitivity of the photoreceptor decreases, the potential after exposure increases, or the residual potential increases. The surface layer preferably contains a charge transporting material or a resin having a charge transporting ability because it is likely to rise.

  The resin that can be used for forming the surface layer is preferably a resin that is transparent to the exposure light used for forming an image and that is excellent in insulation, mechanical strength, and adhesiveness.

  Examples of the inorganic filler include, but are not limited to, alumina, titanium oxide, tin oxide, potassium titanate, TiN, zinc oxide, indium oxide, and antimony oxide.

  The surface layer may further contain a fluorine resin such as polytetrafluoroethylene, a silicone resin, or a resin in which an inorganic filler is dispersed in order to improve wear resistance.

  The surface layer generally has a mechanical strength significantly different from that of the photosensitive layer. Therefore, when the surface layer is worn away due to friction with the cleaning blade, the photosensitive layer is worn. For this reason, the film thickness of the surface layer is usually 0.1 to 12 μm, preferably 1 to 10 μm, and more preferably 2 to 8 μm. If the thickness of the surface layer is less than 0.1 μm, it tends to disappear partially due to friction with the cleaning blade, and if it exceeds 12 μm, the sensitivity of the photoreceptor decreases and the potential after exposure increases. The residual potential is likely to rise.

  Although it does not specifically limit as a plasticizer, Dibutyl phthalate, a dioctyl phthalate, etc. are mentioned. In addition, the usage-amount of a plasticizer is 0-30 mass% normally with respect to resin.

  The antioxidant is not particularly limited, but 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- ( Monophenolic compounds such as 3,5-di-t-butyl-4-hydroxyphenyl) propionate and 3-t-butyl-4-hydroxynisol; 2,2′-methylene-bis (4-methyl-6- t-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3- Bisphenol compounds such as methyl-6-tert-butylphenol); 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3 5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4 ′) -Hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid] glycol ester, tocophenols and other high molecular phenolic compounds; N- Phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-s-butyl-p-phenylenediamine, N-phenyl-Ns-butyl-p-phenylenediamine, N, N′-diisopropyl- para-phenylenediamines such as p-phenylenediamine and N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine; 2,5-di-t-o Such as octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone, etc. Hydroquinones; organic sulfur compounds such as dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate; triphenylphosphine, And organic phosphorus compounds such as tris (nonylphenyl) phosphine, tris (dinonylphenyl) phosphine, tricresylphosphine, and tris (2,4-dibutylphenoxy) phosphine.

  The leveling agent is not particularly limited, and examples thereof include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil; polymers or oligomers having a perfluoroalkyl group in the chain. In addition, the usage-amount of a leveling agent is 0-1 mass% normally with respect to resin.

  Next, an image forming apparatus incorporating a photoconductor to be evaluated will be described.

  FIG. 1 shows an example of an image forming apparatus incorporating a photoconductor to be evaluated. The image forming apparatus 100 includes a drum-shaped photoconductor 10, a lubricant application device 20 that applies a lubricant to the photoconductor 10, a charging roller 30 that charges the photoconductor 10 to which the lubricant is applied, and a charged photoconductor 10. An exposure device (not shown) for forming an electrostatic latent image by exposing the laser beam L to the toner, a developing device 40 for developing the electrostatic latent image with toner to form a toner image, and a toner image for recording medium (or intermediate transfer) A transfer roller 50 for transferring to a medium) and a cleaning device 60 for removing toner remaining on the photoreceptor 10 to which the toner image has been transferred. The image forming apparatus 100 includes a process cartridge 110 in which a photoconductor 10, a lubricant applying device 20, a charging device 30, a developing device 40, and a cleaning device 60 are integrally supported. The main body of the apparatus 100 is detachable.

  The lubricant application device 20 includes a bar 21 made of a lubricant, a brush 22 that contacts the bar 21, applies the lubricant transferred from the bar 21 to the photoconductor 10, and a pressing force that causes the bar 21 to contact the brush 22. And a support guide 25 that supports the bar 21 so that it does not swing back and forth and back and forth.

  The bar 21 is manufactured using a melt molding method in which a lubricant is melted and then charged into a mold and cooled, or a compression molding method in which a lubricant powder is compressed.

  The brush 22 rotates at a linear velocity different from that of the photoconductor 10, and rubs the surface of the photoconductor 10, thereby applying an irregular lubricant held on the surface of the brush 22 to the surface of the photoconductor 10. To do.

  Although it does not specifically limit as the brush 22, The roll brush which wound the tape which made the fiber the pile ground around the metal cored bar spirally can be used.

  The fiber preferably has flexibility in order to suppress mechanical stress on the surface of the photoreceptor 10 of the brush 22. Such fibers are not particularly limited, but polyolefin resins such as polyethylene and polypropylene; polystyrene, styrene-butadiene resin, acrylic resin, styrene-acrylic acid copolymer, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl Polyvinyl and polyvinylidene resins such as butyral, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl carbazole, polyvinyl ether, polyvinyl ketone; polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene Polyester; Nylon; Rayon; Polyurethane; Polycarbonate; Phenol resin; Urea-formaldehyde resin, melamine resin, benzoguanamine Fat, urea resin, amino resin and the like, such as a polyamide resin, may be used in combination. In addition, in order to adjust the degree of bending, flexible fibers are diene rubber, styrene-butadiene rubber (SBR), ethylene propylene rubber, isoprene rubber, nitrile rubber, urethane rubber, silicone rubber, hydrin rubber, norbornene. Rubber or the like may be combined.

  The fiber diameter is usually 10 to 500 μm, preferably 20 to 300 μm. When the fiber diameter is less than 10 μm, the force for scraping the lubricant from the bar 21 may be insufficient, and when it exceeds 500 μm, uneven application of the lubricant may become remarkable.

  The length of the fiber is usually 1 to 15 mm, preferably 3 to 10 mm. If the fiber length is less than 1 mm, the core of the brush 22 and the photoconductor 10 are close to each other, so that the photoconductor 10 may be easily scratched. If it exceeds 15 mm, the lubricant is scraped from the bar 21. The power to take may be insufficient.

The density of the fibers is usually 10,000 to 300,000 per square inch (1.5 × 10 ^{7 to} 4.5 × 10 ⁸ per square meter), and 50,000 to 600,000 per square inch ( 7.5 × 10 ^{7 to} 9.0 × 10 ⁸ per square meter) is preferable. If the density of the fiber is less than 10,000 per square inch, uneven application of the lubricant may become remarkable. If the density exceeds 300,000 per square inch, the force to scrape the lubricant from the bar 21 It may be insufficient.

  Although it does not specifically limit as a manufacturing method of the brush 22, Electrostatic flocking is mentioned. Electrostatic flocking is a method in which an adhesive is applied on a cored bar, and the cored bar is charged to fly the fibers with electrostatic force, and then flocked to the adhesive on the cored bar to cure the adhesive. .

  In addition, you may provide a coating layer on the surface of a fiber as needed. The material constituting the coating layer is not particularly limited as long as it is a flexible material. Polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, and chlorosulfonated polyethylene; polystyrene, polymethyl methacrylate, poly Polyvinyl and polyvinylidene resins such as acrylonitrile, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, polybiliketones; silicone resins and alkyds composed of organosiloxane bonds Modified products by resin, polyester, epoxy resin, polyurethane, etc .; perfluoroalkyl ether, polyfluorovinyl, polyfluorovinylidene, polychlorotrifluoroe Polyamides; polyesters; polyurethanes; polycarbonates; fluororesin Len such as urea - amino resins such as formaldehyde resins, epoxy resins and the like, may be used in combination.

  The layer thickness regulating member 24 includes a blade 24 a, a support 24 b that supports the blade 24 a, and a spring 24 c that applies a pressing force that brings the tip of the blade 24 a into contact with the surface of the photoreceptor 10. The blade 24a is in contact with the surface of the photoreceptor 10 in a counter manner.

  The material constituting the blade 24a is not particularly limited, and examples thereof include elastic materials such as urethane rubber, hydrin rubber, silicone rubber, and fluorine rubber, and two or more kinds may be used in combination. Further, the blade 24a may be coated or impregnated with a material having a small coefficient of friction at a portion in contact with the photoreceptor 10. Furthermore, in order to adjust the hardness of the elastic material, a filler such as an organic filler or an inorganic filler may be dispersed.

  The blade 24a is fixed to the support 24b using a method such as adhesion or fusion. The thickness of the blade 24a is usually 0.5 to 5 mm, preferably 1 to 3 mm. Moreover, the length which can protrude from the support body 24b of the braid | blade 24a and can give a bending | flexion, ie, free length, is 1-15 mm normally, and 2-10 mm is preferable.

  The blade 24a is formed by coating or dipping the surface layer on the surface of an elastic metal blade such as a spring plate via a coupling agent, a primer or the like as necessary. In addition, a material that has been subjected to treatment such as thermosetting or surface polishing may be used.

  The thickness of the elastic metal blade is usually 0.05 to 3 mm, preferably 0.1 to 1 mm. Further, in order to suppress twisting of the blade 24a, a process such as bending may be performed in a direction substantially parallel to the support shaft after the blade 24a is attached.

  The material constituting the surface layer of the blade 24a is not particularly limited, and examples thereof include fluorine resins such as PFA, PTFE, FEP, and PVdF; fluorine rubber; silicone elastomer such as methylphenyl silicone elastomer. The surface layer may contain a filler as necessary.

  The pressing force (linear pressure) with which the tip of the blade 24a is brought into contact with the surface of the photoconductor 10 by the spring 24c may be any force that allows the lubricant on the surface of the photoconductor 10 to spread and become a protective film. Usually, it is 5-80 gf / cm, and 10-60 gf / cm is preferable.

  As described above, by supplying the irregular lubricant to the photoconductor 10, the lubricant is easily held as an irregular protective film on the photoconductor 10. Accordingly, an abnormal image due to dirt or the like of the charging device 30 is less likely to occur, the consumable is not frequently replaced, and a high-quality image can be formed over a long period of time.

  Instead of applying the lubricant by using the lubricant applying device 20, a container filled with the lubricant powder, a pump for transferring the lubricant powder, a protective agent transfer device such as an auger, etc. The powder of the agent may be applied directly to the surface of the photoreceptor 10.

  The charging roller 30 is installed in contact with the photoconductor 10 or in a non-contact state with a gap of 20 to 100 μm. The charging roller 30 superimposes an AC voltage on a DC voltage by a high voltage power source (not shown). The applied voltage is applied. At this time, since the lubricant is applied on the photoconductor 10, deterioration of the photoconductor 10 due to discharge can be suppressed.

  The charging roller 30 preferably has a conductive elastic layer and a surface layer formed on a conductive support.

  The conductive support is not particularly limited as long as it is a material that functions as an electrode and a support member of the charging roller 30; however, a metal or alloy such as aluminum, copper alloy, or stainless steel; iron plated with chromium, nickel, or the like And a resin to which a conductive agent is added.

The conductive elastic layer generally has an electric resistivity of 10 ⁶ to 10 ⁹ Ω · cm, and a conductive agent is added to the polymer material.

  The polymer material is not particularly limited, but polyester; olefin thermoplastic elastomer; styrene thermoplastic such as polystyrene, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, etc. Resins: 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, epichlorohydride Phosphorus-ethylene oxide-allyl glycidyl ether copolymer rubber, ethylene-propylene-diene copolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber, natural rubber and the same Rubber material and the like blended with. The rubber material should be silicone rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, acrylonitrile-butadiene copolymer rubber and rubbers blended with these. Is preferred. The rubber material may be foamed.

  As the conductive agent, an electronic conductive agent or an ionic conductive agent can be used. The electron conducting agent is not particularly limited, but carbon black such as ketjen black and acetylene black; pyrolytic carbon, graphite; metal or alloy such as aluminum, copper, nickel, and stainless steel; tin oxide, indium oxide, titanium oxide And metal oxides such as tin oxide-antimony oxide solid solution and tin oxide-indium oxide solid solution; and the like. The usage-amount of an electronic electrically conductive agent is 1-30 mass% normally with respect to a polymeric material, and 15-25 mass% is preferable. In addition, the ionic conductive agent is not particularly limited, but perchlorates such as tetraethylammonium and lauryltrimethylammonium, chlorates; alkali metals such as lithium and magnesium, perchlorates of alkaline earth metals, chloric acid Examples include salts. The usage-amount of an ionic conductive agent is 0.1-5.0 mass% normally with respect to a polymeric material, and 0.5-3.0 mass% is preferable. These conductive agents may be used in combination of two or more.

  In the surface layer, the above-mentioned conductive agent and fine particles are added to a polymer material.

The polymer material is not particularly limited as long as the dynamic ultra-fine hardness of the surface of the charging roller 30 is 0.04 to 0.5, but polyamide, polyurethane, polyvinylidene fluoride, tetrafluoroethylene copolymer, Polyester, polyimide, silicone resin, acrylic resin, polyvinyl butyral, ethylenetetrafluoroethylene copolymer, melamine resin, fluororubber, epoxy resin, polycarbonate, polyvinyl alcohol, cellulose, polyvinylidene chloride, polyvinyl chloride, polyethylene, ethylene-acetic acid A vinyl copolymer etc. are mentioned, You may use 2 or more types together. Among these, polyamide, polyvinylidene fluoride, tetrafluoroethylene copolymer, polyester, and polyimide are preferable from the viewpoint of releasability with toner. In addition, the number average molecular weight of the polymer material is usually 1 × 10 ³ to 1 × 10 ⁵ , and preferably 1 × 10 ^{4 to} 5 × 10 ⁴ .

  Examples of the fine particles include metal oxides and composite metal oxides such as silicon oxide, aluminum oxide, and barium titanate; fluorine resins such as tetrafluoroethylene and vinylidene fluoride, and two or more kinds may be used in combination.

  The developing device 40 carries and conveys a developer composed of toner and carrier, and a developing roller 41 that supplies toner to the photoreceptor 10 is partially exposed from the opening. The toner replenished from the toner bottle (not shown) into the developing device 40 is conveyed while being agitated with the carrier by the agitating and conveying screws 42 and 43 and is carried on the developing roller 41. The developing roller 41 has a magnet roller (not shown) and a developing sleeve (not shown) that rotates coaxially around the magnet roller. The carrier in the developer is transported to the developing area facing the photoreceptor 10 in a state where the carrier is raised on the developing roller 41 by the magnetic field generated from the magnet roller. Here, the developing roller 41 moves in the same direction at a linear velocity faster than the surface of the photoreceptor 10. Then, the carrier that stands up on the developing roller 41 supplies the toner adhered to the surface of the carrier to the electrostatic latent image formed on the photoconductor 10 while rubbing the surface of the photoconductor 10. ,develop. At this time, a developing bias is applied to the developing roller 41 from a power source (not shown), and a developing electric field is formed in the developing region.

  The cleaning device 60 removes the toner remaining on the surface of the photoreceptor 10 with the cleaning blade 61. The cleaning blade 61 is supported by the pressing mechanism 62 and is in contact with the surface of the photoreceptor 10 in a counter manner.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples.

[Example 1]
After removing 20 photosensitive drums from the process cartridge 110 shown in FIG. 1 collected from the market, it was cleaned. The process cartridge 110 uses a mixture of zinc stearate and zinc palmitate (mass ratio 65:35) as a lubricant. Next, the appearance of the 20 photosensitive drums was inspected with a machine for scratches, dents, distortions, and the like. As a result of inspecting the appearance, the three photosensitive drums had scratches or dents and were determined to be defective. Further, the appearance of the remaining 17 photosensitive drums was visually inspected for any deposits. As a result, one photoconductor drum clearly had a deposit and was determined to be defective.

  Next, ATR-IR spectra of 16 photoconductor drums (hereinafter referred to as photoconductor drums 1 to 16) that were determined to be non-defective products by inspecting the appearance with a machine and using a VARIAN 600UMA (manufactured by VARIAN). It was measured. A Ge prism was used as the ATR prism, and the incident angle of infrared light was 45 °. Further, while holding the photosensitive drum, using a dedicated jig for controlling the position so as to contact the Ge prism with a constant pressure, the measuring points 1 to 7 are sequentially measured while being moved in the longitudinal direction of the photosensitive drum. The ATR-IR spectrum was measured at 7 points. At this time, the measurement points were 7 points, that is, the points at both ends of the image output region and the points that divide the both ends into 6 equal parts. FIG. 2 shows an ATR-IR spectrum at the measurement point 1 of the photoreceptor 1.

  Next, the silica index and the lubricant index were calculated from the ATR-IR spectra of the photosensitive drums 1 to 16. At this time, referring to a new ATR-IR spectrum (see FIG. 3) of the photoconductor, the silica-derived peak and the lubricant-derived peak in the ATR-IR spectrum of the photoconductor drums 1 to 16 exist. It can be seen that the photoreceptor has absorption. Therefore, the ATR-IR spectrum of the photoconductor drums 1 to 16 obtained based on the peak derived from the photoconductor of the ATR-IR spectrum of the photoconductor drums 1 to 16, and the new ATR-IR spectrum of the photoconductor The peak area derived from the silica and the peak area derived from the lubricant in the difference spectrum were used as Sa and Sb, respectively. Specifically, Sa and Sb at the measurement point 1 of the photoconductor 1 are measured by measuring the heights hp and hp ′ of the peaks derived from the photoconductor of the ATR-IR spectrum of FIGS. Measurement was performed using a difference spectrum between the -IR spectrum and the ATR-IR spectrum of FIG. 3 multiplied by hp / hp ′. Table 2 shows the evaluation results of the 16 photoconductors.

表２から、シリカ指標が０．２０未満であると共に、潤滑剤指標が０．７０未満である感光体ドラム１〜３、５〜７、９、１０、１３、１４、１６は、使用が可能であると判定された。

From Table 2, the photosensitive drums 1 to 3, 5 to 7, 9, 10, 13, 14, and 16 having a silica index of less than 0.20 and a lubricant index of less than 0.70 can be used. It was determined that

  Next, the photosensitive drums 1 to 16 were incorporated into a tandem type color image forming apparatus imagio MPC3500 (manufactured by Ricoh Co., Ltd.) from which a plurality of process cartridges 110 can be attached and detached to form 1000 sheets of images at normal temperature and humidity. The linear velocity of the photosensitive member 10 is set to 125 mm / second, and a voltage obtained by superimposing an AC voltage having a frequency of 1450 Hz and an amplitude of 1100 V on a DC voltage of −600 V is applied to the charging roller 30. A mixture of zinc acid and zinc palmitate (mass ratio 65:35) was used.

  As a result, high-quality images were formed on the photosensitive drums 1 to 3, 5 to 11, 13, 14, and 16 up to the 1000th sheet, but up to the 1000th sheet on the photosensitive drums 4, 12, and 15. In addition, abnormal images such as vertical stripes and black stripes occurred.

  Next, after cleaning the photosensitive drums 4, 8 to 16 on which 1000 sheets of images were formed, 100 sheets of images were formed in the same manner as above except that the room temperature and the normal pressure were changed to 28 ° C. and 70% RH. .

  As a result, high-quality images were formed on the photosensitive drums 9, 10, 13, 14, and 16 up to the 100th sheet, but the photosensitive drums 4, 8, 11, 12, and 15 were formed on the 100th sheet. , Image blur occurred.

[Example 2]
In the same manner as in Example 1, the appearance was visually inspected with a machine and visually, and it was determined that the product was good, and 50 photoconductor drums that were determined to be usable were used. After 1000 images were formed with moisture and cleaned, 100 images were formed at 28 ° C. and 70% RH. As a result, high-quality images were formed on all the photosensitive drums up to the 100th sheet.

[Comparative Example 1]
In the same manner as in Example 1, the photoreceptor drum determined to be a non-defective product by inspecting the appearance with a machine and visually was evaluated by the evaluation method disclosed in Patent Document 1. Specifically, first, the photosensitive drum was attached to the evaluation apparatus shown in FIG. Next, while rotating the photosensitive drum (1) at 120 rpm, using the OSSV 5111A (manufactured by OptoSupply) of the ultraviolet LED (3), the peak from the position where the distance from the surface of the photosensitive drum (1) is 5 cm. Irradiation with ultraviolet light having a wavelength of 400 nm was performed. At this time, 20 mA was supplied to the ultraviolet LED (3) by putting a current limiting resistor in a low voltage of DC5V. In addition, S7686 (manufactured by Hamamatsu Photonics) of Si photodiode (6) is attached so as to receive the fluorescence emitted from the photosensitive drum (1), and the ultraviolet LED (3) and the Si photodiode (6) are attached from the left end. It was moved toward the right end at a speed of 2 mm / sec. In addition, the irradiation time of ultraviolet light was 5 seconds per location. The signal received by the Si photodiode (6) was amplified by an operational amplifier, and the change in the signal was examined. As a result, the ATR-IR spectrum of 50 photoconductor drums in which no signal change was observed and no filming was observed was measured in the same manner as in Example 1.

  Next, in the same manner as in Example 1, using 50 photosensitive drums, 1000 sheets of images were formed at normal temperature and humidity, and after cleaning, 100 sheets of images were formed at 28 ° C. and 70% RH.

  As a result, image blurring occurred on the seven photosensitive drums up to the 100th sheet. When the silica index and the lubricant index of these seven photosensitive drums were calculated in the same manner as in Example 1, the silica index was 0.2 or more and / or the lubricant index was 0.7 or more. there were.

JP 2007-171909 A

Claims (4)

A method for evaluating a photoreceptor used in an image forming apparatus having means for supplying a lubricant to the photoreceptor,
A step of cleaning the photoreceptor,
Measuring the ATR-IR spectrum of the cleaned photoreceptor;
The ratio of the area of the peak attributable to silica to the area of a peak derived from the cleaned photosensitive member of the ATR-IR spectrum, and, to the area of a peak derived from the cleaned photosensitive member of the ATR-IR spectrum calculating a ratio of the area of the peak attributable to the lubricant,
Determining whether the cleaned photoreceptor can be used;
With the ratio of the area of the peak attributable to silica to the area of a peak derived from the cleaned photosensitive member of the ATR-IR spectrum is less than 0.20, the cleaned photosensitive member of the ATR-IR spectrum If the ratio of the area of the peak attributable to the lubricant to the area from which the peak is less than 0.70, the cleaned photosensitive member, it is determined that it is possible to use,
The photoreceptor has a surface layer containing polycarbonate,
The lubricant contains zinc stearate and zinc palmitate,
The peak derived from the photoreceptor is a carbonate group peak,
The peak derived from the silica is a Si-O bond peak,
The peak derived from the lubricant is a peak of a bonded portion of zinc ions and carboxylate ions, and the method for evaluating a photoreceptor, wherein: A method for evaluating a photoreceptor used in an image forming apparatus having means for supplying a lubricant to the photoreceptor,
A step of cleaning the photoreceptor,
Measuring the ATR-IR spectrum of the cleaned photoreceptor;
A step of obtaining a difference spectrum between the ATR-IR spectrum and a new ATR-IR spectrum of the photoconductor used in the image forming apparatus with reference to a peak derived from the cleaned photoconductor of the ATR-IR spectrum. When,
The ratio of the area of the peak attributable to silica of the difference spectrum to the area of a peak derived from the cleaned photosensitive member of the ATR-IR spectrum, and, from the cleaned photosensitive member of the ATR-IR spectrum calculating a ratio of the area of the peak attributable to the lubricant of the difference spectrum to the area of the peak,
Determining whether the cleaned photoreceptor can be used;
With the ratio of the area of the peak attributable to silica of the difference spectrum to the area of a peak derived from the cleaned photosensitive member of the ATR-IR spectrum is less than 0.20, cleaned photosensitive of the ATR-IR spectrum When the ratio of the peak area derived from the lubricant in the difference spectrum to the peak area derived from the body is less than 0.70 , the cleaned photoreceptor is determined to be usable ,
The photoreceptor has a surface layer containing polycarbonate,
The lubricant contains zinc stearate and zinc palmitate,
The peak derived from the photoreceptor is a carbonate group peak,
The peak derived from the silica is a Si-O bond peak,
The peak derived from the lubricant is a peak of a bonded portion of zinc ions and carboxylate ions, and the method for evaluating a photoreceptor, wherein: The lubricant, the evaluation method of the photosensitive member according to claim 1 or 2, characterized in that a mixture of zinc stearate and zinc palmitate. When measuring the ATR-IR spectra, as ATR prism, Ge using a prism, any one of claims 1 to 3, characterized in that the angle of incidence of infrared light is 30 ° to 60 ° The method for evaluating a photoreceptor according to 1.

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