JP2007210153A - Rubber roller, its manufacturing method, electrophotographic process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a non-straight cylindrical rubber roller having an end part shape of high precision. <P>SOLUTION: In the manufacturing method of the rubber roller composed of a conductive shaft body and the elastic layer having a non-straight cylindrical shape formed to the outer periphery of the shaft body, the conductive shaft body is coated with a rubber material liquid at the normal temperature using a ring-shaped coating head and, after the coating amount of the rubber material on the conductive shaft body is controlled in the longitudinal direction of the conductive shaft body, the rubber material is cured to manufacture the non-straight cylindrical rubber roller. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a non-cylindrical rubber roller arranged in contact with a photosensitive member, particularly an electrostatic latent image on the photosensitive member, in an image forming apparatus such as an electrophotographic copying apparatus, a printer, and an electrostatic recording apparatus. The present invention relates to a developing roller, a manufacturing method thereof, an electrophotographic process cartridge in which the developing roller is incorporated, and an image forming apparatus.

  In a printer using a conventional electrophotographic system, a photosensitive member is uniformly charged by a charging roller, and an electrostatic latent image is formed by a laser or the like. Next, the developer in the developer container is uniformly applied on the developing roller with a proper charge by the developer supplying roller and the developer regulating member, and the developer is transferred (developed) at the contact portion between the photosensitive member and the developing roller. Done. Thereafter, the developer on the photoconductor is transferred onto a recording sheet by a fixing roller and fixed by heat and pressure. The developer remaining on the photoconductor is removed by a cleaning blade, and a series of processes is completed.

  Various rubber rollers are used in the printer using the electrophotographic system. The rubber roller generally used in the image forming apparatus includes the developing roller, the charging roller, and the fixing roller described above. Since these rubber rollers are in good contact with the photoreceptor, conductive elastic bodies have been actively used in recent years. In an apparatus that requires the rubber roller to be in pressure contact with another member with a uniform nip layer, depending on the demand for image accuracy obtained from the image forming apparatus, the rubber roller may be shaped like a crown or reverse crown in the axial direction of the rubber roller. Therefore, the need for a non-cylindrical rubber roller whose outer diameter is continuously changed along the line is increasing.

  For example, in the developing roller, there are many systems in which a rotating photosensitive member is pressed against the rotating photosensitive member with a predetermined pressure and rotated. This developing roller is required to have an electric resistance ground of a semiconductive region, and it is necessary for obtaining a good image that the developing roller is made of a material having low hardness and low compression set.

  However, when the length in the longitudinal direction is increased to some extent, bending occurs, and a non-uniform situation occurs in which the nip width with the photoreceptor is wide at the end and narrow at the center. As a result, when the developer carried by the developing roller is supplied to the photoconductor, the amount of developer supplied in the longitudinal direction becomes non-uniform, resulting in a defect in the resulting image.

  Therefore, many non-cylindrical rubber rollers have been required to ensure a uniform nip width.

Conventionally, as a manufacturing method of the non-cylindrical rubber roller described above, when unvulcanized rubber is applied on a conductive shaft body by an extrusion method, the conductive shaft is supplied while the rubber material is constantly supplied from a die nozzle that supplies the rubber material. Means have been proposed for producing a non-cylindrical rubber roller by changing the moving speed of the body in the longitudinal direction and changing the rubber material applied on the conductive shaft. (See Patent Document 1)
As another means of the extrusion method, means for manufacturing a non-rectilinear cylindrical rubber roller by changing the supply amount of the rubber material supplied from the die nozzle has been proposed. (See Patent Document 2)
Japanese Patent Laid-Open No. 2003-300279 JP 2004-145012 A

  However, in the above conventional example, when the non-cylinder-shaped rubber roller is made in the conventional technique, the unvulcanized rubber is replaced when the unvulcanized rubber is discharged from the die. There was a possibility that the jumping accuracy would be poor.

  In order to obtain a non-cylindrical rubber roller with good end accuracy, there is a method in which a non-cylindrical roller is obtained by previously applying unvulcanized rubber on a conductive shaft body in advance and cutting off the inaccurate end portion. Has been taken. However, in the case of a shape that cannot be applied on the conductive shaft for a long time, it is difficult to obtain a highly accurate non-cylindrical rubber roller without completely cutting off the end of the rubber with poor accuracy.

  Moreover, it is necessary to remove a lot of inaccurate ends, and there is a problem that a large amount of raw material unvulcanized rubber is required.

  The present invention solves the above-mentioned problems, and an object of the present invention is to form a rubber material by coating the conductive shaft body with a ring-shaped coating head and to make the rubber material conductive. After controlling the coating amount on the shaft body in the longitudinal direction, by curing the rubber material, to provide a manufacturing method that can obtain a rubber roller with good accuracy of the end of the rubber roller that is a non-cylindrical part, It is to provide a rubber roller obtained by the manufacturing method.

  As a result of intensive studies to solve the above problems, the present inventors finally came to the invention.

  According to the first invention of the present application, in a method of manufacturing a rubber roller comprising a conductive shaft body and an elastic layer having a non-cylindrical cylindrical shape formed on the outer periphery of the conductive shaft body, a rubber material that is liquid at room temperature Having a non-cylindrical shape by curing the rubber material using a ring-shaped coating head on the shaft body while controlling the coating amount of the rubber material in the longitudinal direction. This is a method of manufacturing a rubber roller.

  According to the second invention of the present application, a conductive shaft is installed at the center of the ring-shaped coating head ring, and the rubber material is applied to the coating head through a slit provided in the coating head. The rubber material is coated on the conductive shaft body by supplying a constant amount to the gap between the conductive shaft bodies and adjusting the speed of the conductive shaft body, and then the rubber material is cured. This is a method for manufacturing the rubber roller in which the elastic layer is formed in a non-cylindrical shape.

  According to the third invention of the present application, as means for forming the non-right cylindrical portion of the rubber roller, when the rubber material is coated on the conductive shaft body, the conductive shaft body has the The method of manufacturing a rubber roller as described above, wherein the moving speed at the time of coating the rubber material is continuously adjusted.

  According to the fourth invention of the present application, in the moving speed of the conductive shaft body, the ratio of the moving speed between the highest speed and the lowest speed, or the value of the lowest speed / maximum speed is 85% or more and 100% or less. It is a manufacturing method of said rubber roller characterized by the above-mentioned.

  According to a fifth aspect of the present application, in the rubber roller, the maximum thickness of the elastic layer after the rubber material is cured is greater than 2 mm and equal to or less than 6 mm, and the maximum outer diameter in the rubber roller. The difference between the minimum value and the minimum value is 0% to 10% of the maximum thickness of the elastic layer.

  According to a sixth aspect of the present invention, in the rubber roller, the maximum thickness of the elastic layer after the rubber material is cured is greater than 2 mm and less than or equal to 5 mm. It is a manufacturing method.

  Moreover, according to 7th invention which concerns on this application, it is a rubber roller manufactured by the method in any one of said.

  According to the eighth invention of the present application, the rubber roller carries a developer on its surface to form a thin film of developer, and the latent image developer is applied to the surface of the latent image holding member from the thin film of developer. The rubber roller described above, wherein the rubber roller is a developing roller that is attached to visualize the electrostatic latent image.

  According to the ninth aspect of the present application, the electrostatic latent image is obtained by bringing an electrostatic holding body that holds the electrostatic latent image into contact with a developing roller that carries a nonmagnetic developer on the surface. In the developing method for visualizing, a developer is carried on the surface of the developing roller to form a thin film of the developer, and a latent image developer is adhered to the surface of the latent image holding member from the thin film of the developer to form an electrostatic latent image. A developing method using the above-described developing roller to be visualized.

  According to a tenth aspect of the present application, a developing roller is mounted, a thin layer of developer is formed on the surface of the developing roller, and the developing roller is brought into contact with the photosensitive member to thereby form the photosensitive member. In the electrophotographic process cartridge in which a visible image is formed on the surface of the photosensitive member by supplying the developer to the surface, the developing roller is the developing roller described above.

  According to an eleventh aspect of the present application, the developing roller is mounted, a thin layer of developer is formed on the surface of the developing roller, and the developing roller is brought into contact with the photosensitive member to thereby form the photosensitive member. In the image forming apparatus for forming a visible image on the surface of the photosensitive member by supplying the developer to the surface, the developing roller is the developing roller described above.

  As described above, according to the invention of the present application, it is possible to easily manufacture a non-cylindrical rubber roller, and it is possible to prevent rubber from being used by using a liquid rubber material at room temperature. It is possible to produce a non-cylindrical rubber roller with excellent end accuracy.

  As a result, when manufacturing a non-cylindrical cylindrical rubber roller with a predetermined accuracy, the amount of cut off of the end portion with low accuracy is small, and it is possible to apply the rubber material to a portion closer to both end portions on the conductive shaft body. It is. As a result, the rubber roller used as the image forming apparatus can be made compact.

  At the same time, the yield of the rubber material used tends to be good, leading to cost reduction.

  Further, when the rubber roller manufactured as described above is used as a developing roller in the image forming apparatus, the nip width with the photosensitive member is uniform and the end shape is excellent, so that both ends of the obtained image are obtained. The image adverse effects such as the difference in density between the central portion and the central portion and the uneven density of the developing roller pitch at both ends of the image are improved.

  Embodiments of a method for producing a non-cylindrical rubber roller according to the present invention will be described below with reference to the drawings. FIG. 2 is a schematic view showing an apparatus to which the method for producing a non-cylindrical rubber roller according to the embodiment of the present invention is applied.

  As an example, in the coating apparatus of this embodiment, as shown in FIG. 2, a column 2 is attached substantially vertically on the gantry 1, and a precision ball screw 3 is attached substantially vertically on the gantry 1 and the column 2. It has been. Reference numeral 14 denotes a linear guide, two of which are mounted on the column 2 in parallel with the precision ball screw 3.

  The LM guide 4 is connected to the linear guide 14 and the precision ball screw 3, and the rotary motion is transmitted from the servo motor 5 through the pulley 6 so that the LM guide 4 can move up and down in the direction of the arrow in FIG.

  A ring-shaped coating head 8 that discharges the coating liquid is attached to the column 2 on the outer peripheral surface of the cylindrical conductive shaft body 101.

  Further, a bracket 7 is mounted on the LM guide 3, and a workpiece lower holding shaft 9 for holding and fixing the conductive shaft 101 of the rubber roller is mounted substantially vertically on the bracket 7, and the conductive shaft of the rubber roller on the opposite side is mounted. The center axis of the workpiece holding shaft 10 that holds 101 is attached to the upper portion of the bracket 7, and the workpiece holding shaft is disposed so as to be substantially concentric with the workpiece lower holding shaft 9, so that a conductive shaft is provided. keeping. Further, the center axis of the ring-shaped coating head 8 is supported so as to be parallel to the moving direction of the workpiece lower holding shaft 9 and the workpiece upper holding shaft 10, respectively. Also, the workpiece lower holding shaft 9 and the workpiece upper holding shaft 10 are supported. Is adjusted so that the central axis of the discharge port formed in the annular slit opened inside the coating head 8 and the central axes of the workpiece lower holding shaft 9 and the workpiece upper holding shaft 10 are substantially concentric when moving up and down. It is. With such a configuration, the central axis of the discharge port formed in the annular slit of the coating head 8 can be aligned substantially concentrically with the central axis of the conductive shaft body, and the inner peripheral surface of the ring-shaped coating head and the aforementioned A uniform gap is formed between the outer peripheral surface of the conductive shaft body 101.

  The rubber material supply port 11 is connected to a material supply valve 13 through a rubber material conveying pipe 12. The material supply valve 13 includes a mixing mixer, a material supply pump, a material fixed amount discharge device, a material tank, and the like in front of the material supply valve 13 so that a fixed amount (a constant amount per unit time) can be discharged.

  Next, an outline of a process of applying a rubber material on the conductive shaft 101 by this apparatus will be described. The conductive shaft body 101 attached to the workpiece lower holding shaft 9 and the workpiece upper holding shaft 10 can move up and down at a specified speed by controlling the rotation speed of the servo motor 5 by programming. The application amount of the rubber material applied on the conductive shaft 101 depends on the moving speed of the conductive shaft when the rubber material discharged from the coating head is constant. That is, when the moving speed of the conductive shaft body is high, the amount of rubber applied on the conductive shaft body is reduced, and the thickness of the resulting rubber roller is reduced.

  In this way, when applying a rubber material to the conductive shaft using the coating head, the discharge rate of the rubber material is made constant and the moving speed of the conductive shaft is changed depending on the portion in the length direction. Thus, it is possible to manufacture a rubber roller in which the film thickness of the rubber material, that is, the outer diameter of the rubber roller is changed along the longitudinal direction by a portion in the length direction of the conductive shaft body. By subjecting this unvulcanized rubber roller to vulcanization finishing, a rubber roller whose outer peripheral shape is a crown shape or a reverse crown shape is obtained.

  Here, the ratio of the maximum speed and the minimum speed of the moving speed of the conductive shaft body, or the value of the minimum speed / maximum speed is set to 85% or more and 100% or less.

  When the ratio between the maximum speed and the minimum speed is less than 85%, the amount of change in the moving speed is large, and it is necessary to increase the accuracy of the apparatus. More preferably, it is 93% or more and 97% or less.

  The maximum thickness of the non-cylindrical rubber roller formed on the conductive shaft is greater than 2 mm and not greater than 6 mm, preferably greater than 2 mm and not greater than 5 mm, preferably not less than 3 mm and not greater than 5 mm. is there. When the thickness of the rubber roller is 2 mm or less, the hardness of the obtained rubber roller is high, and when used as an image forming apparatus, the stress applied to the abutting member is strong, and there is a high possibility that the lifetime will be shortened. When the wall thickness is larger than 6 mm, it is necessary to increase the amount of rubber discharged by the ring-shaped coating head, and it is necessary to further improve the accuracy of the supply pump that supplies the rubber material. A more preferable range is 3 mm or more and 5 mm or less.

  The difference between the maximum value and the minimum value of the outer diameter in the rubber roller is 0% or more and 10% or less of the maximum thickness of the elastic layer. If the difference between the maximum value and the minimum value is larger than 10% of the maximum thickness of the elastic layer, the accuracy of the end shape of the obtained rubber roller is poor, and when used as an image forming apparatus, the image end device and the photoconductor Since the nip is non-uniform, image defects such as density unevenness generated at the rubber roller pitch occur, and the required image performance cannot be obtained. A more preferable range is 3% or more and 8% or less.

  Here, an example of a method for measuring the thickness and shape deflection of the rubber roller will be described. For the measurement of wall thickness and shape deflection, a rubber roller is rotated about the conductive shaft as a rotation axis, a non-contact laser length measuring device (LS-5000 manufactured by Keyence) is installed perpendicularly to the rotation axis, and the conductive shaft is measured. Using the end surface as a reference, the distance to the outer peripheral surface of the rubber roller was measured to obtain a wall thickness. Further, the difference between the maximum value and the minimum value at the measurement location of the measured wall thickness was taken as the shape shake value. The measurement location was measured at a location approaching the center by 1 mm from both ends of the rubber roller and a central portion of the rubber roller (a center position in the longitudinal direction).

  An example of the rubber roll of the present invention is shown in FIG.

  The rubber roll of the present invention has an elastic layer 102 around a conductive shaft 101 and a surface layer 103 arranged on the outer periphery thereof. The surface layer does not have to be a single layer and may be a multilayer.

  The conductive shaft body of the rubber roller used in the present invention is, for example, a cylinder having a carbon steel alloy surface subjected to industrial nickel plating having a thickness of 5 μm. In addition to the materials constituting the conductive shaft 101, for example, alloys such as iron, aluminum, titanium, copper and nickel, alloys of stainless steel, duralumin, brass and bronze containing these metals, and carbon black and carbon fibers are also included. It is also possible to use a known material that is rigid and shows conductivity, such as a composite material hardened with plastic. Moreover, as a shape, it can also be set as the cylindrical shape which made the center part the cavity besides the column shape. The outer diameter of the conductive shaft is usually in the range of 4 to 10 mm.

  A conductive elastic layer can be formed on the outer periphery of the conductive shaft body. As a preferable material for forming the conductive elastic layer, various liquid rubbers can be used. Specific examples include rubber materials such as diene rubber, silicone rubber, polysulfide rubber, and urethane rubber. In addition, these rubber materials can be used alone or in admixture of two or more as long as they give desired mechanical properties when molded by adding other components. The rubber material is a liquid rubber material at room temperature, and the viscosity at 25 ° C. in a B-type viscometer is preferably 100 to 10,000 poise. If the viscosity of the B-type viscometer is less than 100, the shape of the rubber material cannot be maintained against gravity, and only a rubber roller with poor accuracy can be obtained. On the other hand, when the viscosity exceeds 10,000, a stress for structural destruction of the rubber material is applied, and the surface of the obtained rubber roller is likely to be indented or streaked. The viscosity was measured with a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) using a No. 4 spindle at 12 rpm.

  Among them, when used for an image forming apparatus, it is desirable to use silicone rubber in consideration of the required hardness and compression set as described above. Liquid silicone rubber has excellent processability, has no dimensional stability due to the absence of by-products associated with the curing reaction, and has been subjected to addition reaction crosslinking for reasons such as stable physical properties after curing. Type liquid silicone rubber is preferred.

  The liquid silicone rubber can be a composition containing, for example, an organopolysiloxane represented by Formula 1 and an organohydrogenpolysiloxane represented by Formula 2, and further containing a catalyst and other additives as appropriate.

  Organopolysiloxane is a base polymer of a silicone rubber raw material. From the viewpoints of processing characteristics and characteristics of the resulting silicone rubber composition, the molecular weight of the organopolysiloxane is preferably 10,000 to 1,000,000, and the average molecular weight is preferably 50,000 to 700,000.

  Organohydrogenpolysiloxane functions as a crosslinking agent for addition reaction in the curing process, and the number of silicon atom-bonded hydrogen atoms in one molecule is 2 or more, and in order to perform the curing reaction optimally, Three or more polymers are preferred. The molecular weight of the polyorganohydrogensiloxane is not particularly limited and is, for example, from 1000 to 10,000, but a relatively low molecular weight (1000 or more and 5000 or less) is preferable in order to appropriately perform the curing reaction.

Examples of the conductive agent that can be included in the liquid silicone rubber include conductive plasticizers, ion conductive materials such as KSCN, LiClO ₄ , NaClO ₄ , quaternary ammonium salts, aluminum, palladium, iron, copper, silver, and the like. Metal-based powders and fibers; metal oxides such as titanium oxide, tin oxide, and zinc oxide; metal compound powders such as copper sulfide and zinc sulfide; or the surface of appropriate particles such as tin oxide, antimony oxide, indium oxide, and oxidation Powder with molybdenum, zinc, aluminum, gold, silver, copper, chromium, cobalt, iron, lead, platinum, rhodium deposited by electrolytic treatment, spray coating, mixed shaking; acetylene black, ketjen black, PAN And carbon powders such as carbon black and pitch carbon black.

  As content of the material which has electroconductivity in coating | covering material, in the case of the compound which has ionic conductivity, it is preferable that it is the range of 0.01-15 mass%, and is the range of 0.1-10 mass%. It is more preferable. If the amount is less than 0.01%, the amount is not sufficient to exhibit conductivity. If the amount is more than 15% by mass, the effect of conductivity is hardly obtained.

  In the case of carbon black or the like, depending on the type, it is preferably in the range of 5 to 40% by mass, more preferably 10 to 30% by mass. When the amount is less than 5% by mass, the amount is not sufficient for exhibiting electrical conductivity. When the amount is more than 40% by mass, the balance with the amount of polymer is poor, and preferable mechanical properties as a roller used in electrophotography cannot be obtained.

  Examples of reinforcing fillers and extenders that can be included in the liquid silicone rubber include fumed silica, wet silica, quartz fine powder, diatomaceous earth, carbon black, zinc oxide, basic magnesium carbonate, activated calcium carbonate, and silica. Examples thereof include magnesium oxide, aluminum silicate, titanium dioxide, talc, mica powder, aluminum sulfate, calcium sulfate, barium sulfate, glass fiber, organic reinforcing agent, and organic filler. The surface of these fillers may be hydrophobized by treating with an organosilicon compound such as polydiorganosiloxane. The filling amount is preferably in the range of 0 to 70% by mass, and more preferably 0 to 30% by mass. When the amount is more than 70% by mass, the balance with the polymer amount is deteriorated, and mechanical properties preferable as a rubber roller used in electrophotography cannot be obtained.

  The type and amount of filler and conductive agent are important for controlling the material yield value and thixotropy index. The smaller the particle size added, the larger the surface area, so the viscosity of the unvulcanized material increases, and the better the dispersion of the particles, the higher the material yield value and thixotropy index. Furthermore, when the particle shape is almost spherical or when the surface active group of the particle has a strong affinity with the polymer, the reinforcing effect acting on the rubber molecule is increased and the same tendency is observed. In addition, there is a tendency to reduce the thixotropy index by mixing those having different particle diameters or different affinity.

  Examples of plasticizers that can be included in the liquid silicone rubber include polydimethylsiloxane oil, diphenylsilanediol, trimethylsilanol, phthalic acid derivatives, adipic acid derivatives, and softeners such as lubricating oil, process oil, and coal. Examples of tar, castor oil, and anti-aging agents include phenylenediamines, phosphates, quinolines, cresols, phenols, dithiocarbamate metal salts, and heat-resistant agents such as iron oxide, cerium oxide, and hydroxide. Potassium, iron naphthenate, potassium naphthenate, other processing aids, colorants, ultraviolet absorbers, flame retardants, oil resistance improvers, foaming agents, scorch inhibitors, tackifiers, lubricants, and the like can be added.

  As a means for dispersing the fine powdered conductive agent and filler, a conventionally used means such as a roll kneader, a Banbury mixer, a roll mill, a planetary mixer or the like may be used as appropriate.

  In the present invention, a resin layer can also be formed as a surface layer on the surface of the rubber roller formed as described above. The reason for forming the surface layer is to improve durability when used as an image forming apparatus, to impart charge to the developer and other members, or to prevent bleeding such as oil inside the rubber roller.

  Examples of the material for forming the surface layer include various polyamides, fluororesins, hydrogenated styrene-butylene resins, urethane resins, silicone resins, polyester resins, phenol resins, imide resins, olefin resins, and the like.

  These materials constituting the surface layer are dispersed using a conventionally known dispersion apparatus using beads such as a sand mill, a paint shaker, a dyno mill, a pearl mill or the like. The obtained dispersion for forming the surface layer is applied to the surface of the conductive substrate by a spray coating method, a dipping method or the like. In the present invention, the surface of the rubber roller is preferably uniformly rough, and spray coating is particularly preferably used.

  The thickness of the surface layer is preferably 5 μm or more from the viewpoint of preventing the low molecular weight component from seeping out and contaminating the photoreceptor, and is preferably 50 μm or less from the viewpoint of preventing the rubber roller from becoming hard and causing fusion. . More preferably, it is 10-30 micrometers.

  Asperities on the roller surface can be formed by dispersing fine particles having a mass average particle diameter of 1 to 20 μm in the surface layer formed as described above. Examples of the fine particles used for such purpose include plastic pigments such as polymethyl methyl methacrylate fine particles, silicone rubber fine particles, polyurethane fine particles, polystyrene fine particles, amino resin fine particles, and phenol resin fine particles. Methyl acid fine particles and silicone rubber fine particles are preferable. These fine particles are preferably added in a range of about 5 to 40% by mass of the surface layer (based on the total mass of surface layer constituent components excluding the fine particles).

  FIG. 1 shows a schematic configuration of a developing device using the rubber roller of the present invention as a developing roller, and an image forming device using the rubber roller as at least one of a developing roller, a charging roller, a transfer roller, a fixing roller, and a pressure roller. It is sectional drawing shown.

  In this image forming apparatus, the photosensitive member 21 as a latent image carrier rotates in the direction of arrow A, and the region of the photosensitive member 21 passing therethrough is uniformly charged by the charging roller 22 for charging the photosensitive member 21. Further, in this charged region, an electrostatic latent image is formed on the surface by laser light 23 which is an exposure means for writing the electrostatic latent image. The electrostatic latent image is arranged close to the photosensitive member 21 and developed by applying a toner as a developer by a developing device 35 that can be attached to and detached from the image forming apparatus main body, and is visualized (realized) as a toner image. Is done.

  For development, a method such as so-called reversal development in which a toner image is formed on the exposed portion can be used. The visualized toner image (image) on the photoreceptor 21 is transferred onto a transfer paper 33 such as paper by a transfer roller 29. The transfer paper 33 to which the toner image has been transferred is fixed by the fixing roller 32 and the pressure roller 36, and is discharged out of the apparatus, thus completing the printing operation. The transfer roller 29 is a region that holds the toner image on the photosensitive member 21 by pressing the transfer paper 33 from the back surface thereof to transfer the toner image onto the surface of the transfer paper. On the contrary, the toner image transfer is promoted by being charged. The transfer paper 33 is pressed against the surface of the photoconductor 21 by automatically inserting the transfer paper 33 into a portion where the photoconductor 21 and the transfer roller 29 are in contact with each other. Achieved.

  On the other hand, the untransferred toner remaining on the photosensitive member 21 without being transferred is scraped off by the cleaning blade 30 and stored in the waste toner container 31, and the same process is performed by repeating the above process on the cleaned photosensitive member 21. Images can be copied and new images can be transferred.

  In the example shown in the figure, the developing device 35 is located opposite to the photosensitive device 21 in a developing device 34 containing a developer 28 as a one-component developer and an opening extending in the longitudinal direction in the developing container 34. A developing roller 25 as a developer carrying member is provided, and the electrostatic latent image on the photosensitive member 21 is developed and visualized.

  The developing roller 25 is in contact with the photoreceptor 21 with a contact width. In the developing device, the developer supply roller 26 having elasticity is brought into contact with the contact portion between the developer regulating member 27 and the surface of the developing roller 25 in the developing container 34 on the upstream side in the rotation direction of the developing roller 25. And it is rotatably supported. As the structure of the developer supply roller 26, a foamed skeleton-like sponge structure or a fur brush structure in which fibers such as rayon and nylon are planted on a shaft body is used. It is preferable from the point of peeling off. In the present embodiment, a developer supply roller 26 having a diameter of 16 mm and having a polyurethane foam on a shaft is used.

  As the contact width of the developer supply roller 26 with respect to the developing roller 25, 1 to 8 mm is effective, and it is preferable to give a relative speed to the developing roller 25 at the contact portion. Is a driving means (not shown) in which the contact width is set to 3 mm and the peripheral speed of the developer supply roller 26 is 50 mm / s during development operation (the relative speed to the developing roller 25 is 130 mm / s). Is driven to rotate at a predetermined timing.

  Normally, the developing container 34 and the developing roller 25, the developer supply roller 26, the developer 28, the developer regulating member 27, and the like are used as a unitary process cartridge, and parts are exchanged in the state of the process cartridge. Further, a process cartridge such as a developing device 35 including the photosensitive member 21, the waste toner container 31, and the charging roller 22 is also used.

  Hereinafter, the present invention will be described more specifically with reference to examples.

  In the specific examples described below, commercially available high-purity products were used as reagents used in the respective examples unless otherwise specified.

[Elastic layer rubber material]
Liquid silicone rubber was used to form the elastic layer. The liquid silicone rubber was used as a base material by blending organopolysiloxane with silica powder, quartz powder, carbon black or the like as a filler. Further, a mixture of a small amount of a platinum compound as a curing catalyst is referred to as a mixture A, and a mixture of an organohydrogenpolysiloxane as a mixture B, which are respectively set in the raw material tank 1 and the raw material tank 2 attached to the ring coat machine, and are pumped. The mixture A and the mixture B were mixed in a ratio of 1: 1 by feeding to a static mixer.

〔Production method〕
For the conductive shaft, use iron whose surface is chemically nickel-plated, apply a primer on the surface (DY39-051: manufactured by Toray Dow Corning Silicone), and heat-treat at 150 degrees for 30 minutes in an electric furnace. went. Place the conductive shaft (work) after primer treatment on the ring coater work holding shaft, clamp it with the upper holding shaft 10 and the lower holding shaft, lower the work to the coating start position, and stop the work. Simultaneously with the start of rising, the material was discharged from the ring coating head at a constant discharge amount, and the rubber material was applied while moving the workpiece at a specified speed.

  Next, a rubber roller was formed by irradiating with a near-infrared heater while rotating the coated workpiece in a horizontal state, and curing it by heating. Thereafter, heat treatment was carried out at 200 ° C. for 4 hours in an electric furnace for the purpose of stabilizing the physical properties after curing of the silicone rubber elastic layer and removing reaction residues and unreacted low molecular components in the silicone rubber roller.

Liquid silicone rubber material (Molecular weight Mw = 100000) 80% by mass
Carbon black (Denka black powder, manufactured by Denki Kagaku Kogyo) 7% by mass
Denka Black is a registered trademark.

Silica (AEROSIL50 made by Nippon AERZIL) 13% by mass
AEROSIL is a registered trademark.

  The above blend was mixed and defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material. Furthermore, 0.02 part of an isopropyl alcohol solution of chloroplatinic acid (platinum content 3% by mass) is added to 100 parts of this base material and mixed to obtain a mixture A, and an organohydrogenpolysiloxane having a viscosity of 10 cps (SiH content) 1 part by weight) 1.5 parts was added and mixed to obtain a mixture B. The mixture A and the mixture B were set in the raw material tank 1 and the raw material tank 2, respectively, and sent to a static mixer using a pressure feed pump to mix the mixture A and the mixture B at a ratio of 1: 1.

Using this material, the inner diameter of the ring coating head is 15.0 mm, the workpiece rising speed is 11.0 mm / sec at the start of coating, and up to 20% of the length in the longitudinal direction is a quadratic function. After reaching 20% of the length in the longitudinal direction, the rising speed is fixed at 10.5 mm / sec. After reaching 80%, the rising speed is reduced to 2%. degree function increased, at the time of coating ends set to increase speed is 11.0 mm / sec, and coated with a material discharge rate 1680mm ³ / sec, the length 250mm around the conductive shaft of φ7mm A liquid rubber material layer was formed. Further, after coating, move quickly to the heater so as not to give an impact to the workpiece, rotate at 30 rpm in a horizontal state, and 4 minutes with an infrared heater (HYL25, manufactured by Hybek: workpiece heater distance 60 mm, output 780 W) A rubber roller having a maximum outer diameter of 14.6 mm was formed by heat curing, and then heat-treated at 200 ° C. for 4 hours in an electric furnace.

[Conductive surface layer]
100 parts by mass of polyurethane polyol prepolymer (trade name: Takelac TE5060; manufactured by Mitsui Takeda Chemical Co., Ltd. Takelac is a registered trademark)
63 parts by mass of isocyanate (trade name: Coronate 2521; manufactured by Nippon Polyurethane Co., Ltd. Coronate is a registered trademark)
20 parts by mass of carbon black (trade name: MA100; manufactured by Mitsubishi Chemical Corporation)
20 parts by mass of urethane particles (trade name: C400; manufactured by Negami Kogyo Co., Ltd.)
MEK was added to the raw material mixture and dispersed with a sand mill for 1 hour. After dispersion, MEK was further added to adjust the solid content in the range of 20% to 30% (so that the film thickness was 20 μm) as the raw material liquid for the conductive surface layer. The conductive shaft after the formation of the conductive elastic layer was immersed in the raw material liquid for the conductive surface layer to coat the outer surface of the conductive elastic layer, and then pulled up and dried naturally. Next, the raw material of the coated conductive surface layer is cured by heat treatment at 140 ° C. for 60 minutes, the conductive surface layer is laminated on the outer peripheral surface of the conductive elastic layer, and the surface roughness ( Rz) A conductive surface layer of 7.2 μm was formed, and a developing roller was prepared.

  The surface roughness Rz was measured using a contact-type surface roughness meter (Surfcoder SE-3500, manufactured by Kosaka Laboratory), with a cutoff of 0.8 mm, a measurement length of 2.5 mm, and a measurement speed of 0.1 mm / sec. As measured. Three locations in the longitudinal direction of the rubber roller (50% position (longitudinal center position), 20% and 80% positions from the end face of the entire length of the developing roller) and three locations in the circumferential direction (positions every 120 °). It is the average value of a total of nine places.

  The ascent speed of the workpiece is 13.4 mm / sec at the start of coating, and the ascent speed is reduced by a quadratic function up to a position of 10% of the length in the longitudinal direction. After reaching the 10% position, the rising speed is fixed at 13.0 mm / sec, and after reaching the 90% position, the rising speed is increased by a quadratic function. A developing roller was prepared in the same manner as in Example 1 except that the setting was 13.4 mm / sec.

  The rising speed of the workpiece is 10.8 mm / sec at the start of coating, and the rising speed is decreased linearly up to a position of 10% with respect to the length in the longitudinal direction. After reaching the 10% position, the ascent rate is fixed at 10.0 mm / sec. After reaching the 90% position, the ascent rate is increased by a quadratic function. A developing roller was prepared in the same manner as in Example 1 except that the conductive shaft was set to 8 mm / sec and a φ6.5 mm conductive shaft was used.

  The ascent speed of the workpiece is 10.4 mm / sec at the start of coating, and the ascent speed is reduced by a quadratic function up to a position of 10% of the length in the longitudinal direction. After reaching the 10% position, the rising speed is fixed at 10.0 mm / sec. After reaching the 90% position, the rising speed is increased by a quadratic function. A developing roller was prepared in the same manner as in Example 3 except that the setting was 10.4 mm / sec.

  The inner diameter of the ring coating head is φ14.0 mm, the workpiece lifting speed is 13.8 mm / sec at the start of coating, and the lifting speed decreases linearly up to 20% of the length in the longitudinal direction. After reaching the position of 20% relative to the length in the longitudinal direction, the rising speed is fixed at 13.0 mm / sec, and after reaching the position of 80%, the rising speed is increased linearly, A developing roller was formed in the same manner as in Example 1 except that the rising speed was set to 14.0 mm / sec at the end of coating.

  The rising speed of the workpiece is 14.5 mm / sec at the start of coating, and the rising speed is linearly decreased up to a position of 10% with respect to the length in the longitudinal direction. After reaching the 10% position, the ascent rate is fixed at 14.0 mm / sec. After reaching the 90% position, the ascent rate is increased linearly. At the end of coating, the ascent rate is 14.5 mm / sec. The developing roller was prepared in the same manner as in Example 5 except that a conductive shaft having a diameter of 8.0 mm was used.

Liquid silicone rubber material (molecular weight Mw = 100000) 50% by mass
Liquid silicone rubber material (molecular weight Mw = 500000) 30% by mass
Carbon black (Denka black powder, manufactured by Denki Kagaku Kogyo) 10% by mass
Silica (Aerosil 200 from Nippon Aerosil) 10% by mass
The above blend was mixed and defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material.

  In the same manner as in Example 1, mixture A and mixture B were mixed at a ratio of 1: 1.

Using this material, the ring coating head has an inner diameter of φ16.0 mm, the workpiece rising speed is 9.8 mm / sec at the start of coating, and up to 15% of the length in the longitudinal direction is a quadratic function. After reaching the position of 15% relative to the length in the longitudinal direction, the rising speed is fixed at 9.0 mm / sec, and after reaching the position of 85%, the rising speed is reduced to 2 It is increased as a next function, and when the coating is completed, the ascending speed is set to 9.8 mm / sec, coating is performed at a material discharge rate of 1680 mm ³ / sec, and a length of 250 mm around a φ7 mm conductive shaft. A liquid rubber material layer was formed. Further, after coating, move quickly to the heater so as not to give an impact to the workpiece, rotate it at 30 rpm in a horizontal state, and use an infrared heater (HYL25, manufactured by Hybeck Co., Ltd .: workpiece heater distance 60 mm, output 780 W) for 5 minutes. A rubber roller having a diameter of 15.9 mm was formed by heat curing. A developing roller was prepared in the same manner as in Example 1.

  The inner diameter of the ring coating head is φ17.0 mm and the workpiece lifting speed is 7.2 mm / sec at the start of coating. The lifting speed is linearly reduced to a position of 15% of the length in the longitudinal direction. After reaching the position of 15% of the length in the longitudinal direction, the rising speed is fixed at 7.0 mm / sec. After reaching the position of 85%, the rising speed is increased linearly and the coating speed is increased. A developing roller was prepared in the same manner as in Example 7 except that the rising speed was set to 7.2 mm / sec at the end of the work, and a conductive shaft having a diameter of 5.0 mm was used.

  The workpiece rising speed is 11.0 mm / sec at the start of coating, and the rising speed is linearly decreased up to a position of 20% of the length in the longitudinal direction, with respect to the length in the longitudinal direction. After reaching the 20% position, the ascent rate is fixed at 10.0 mm / sec. After reaching the 80% position, the ascent rate is increased linearly. At the end of coating, the ascent rate is 11.0 mm / sec. A developing roller was prepared in the same manner as in Example 3 except that the setting was made so that

The workpiece rising speed is 12.5 mm / sec at the start of coating, and the rising speed is decreased linearly up to a position of 15% of the length in the longitudinal direction, with respect to the length in the longitudinal direction. After reaching the 15% position, the ascent speed is fixed at 12.0 mm / sec. After reaching the 85% position, the ascent speed is increased linearly. At the end of coating, the ascent speed is 12.5 mm / sec. A developing roller was prepared in the same manner as in Example 1 except that coating was performed on a conductive shaft having a diameter of 10.0 mm and a rubber material discharge rate of 840 mm ³ / sec.

The inner diameter of the ring coating head is φ17.0 mm, the workpiece rising speed is 11.5 mm / sec at the start of coating, and the lifting speed is a quadratic function up to 10% of the length in the longitudinal direction. After reaching 10% of the length in the longitudinal direction, the ascent rate is fixed at 10.0 mm / sec, and after reaching 90%, the ascent rate is expressed as a quadratic function. Except that the lifting speed was set to 11.5 mm / sec at the end of coating, and the coating was carried out on a conductive shaft having a diameter of 4.0 mm at a rubber material discharge rate of 2960 mm ³ / sec. A developing roller was prepared in the same manner as in No. 1.

The inner diameter of the ring coating head is φ13.5 mm, and the workpiece rising speed is 5.1 mm / sec at the start of coating. The rising speed is linearly reduced to a position of 15% of the length in the longitudinal direction. After reaching the position of 15% of the length in the longitudinal direction, the rising speed is fixed at 5.0 mm / sec. After reaching the position of 85%, the rising speed is linearly increased and the coating speed is increased. The same method as in Example 1 except that the lifting speed was set to 5.1 mm / sec at the end of the process, and coating was performed on a conductive shaft body of φ10.0 mm at a rubber material discharge rate of 200 mm ³ / sec. A developing roller was created.

The inner diameter of the ring coating head is φ16.0 mm, the workpiece rising speed is 10.6 mm / sec at the start of coating, and the rising speed is a quadratic function up to 20% of the length in the longitudinal direction. After reaching 20% of the length in the longitudinal direction, the ascent rate is fixed at 9.0 mm / sec. After reaching 80%, the ascent rate is increased by a quadratic function. Except that the rising speed was set to 10.6 mm / sec at the end of coating, and the coating was performed on a conductive shaft having a diameter of 7.0 mm with a rubber material discharge rate of 1680 mm ³ / sec. A developing roller was prepared in the same manner as in No. 1.

  The inner diameter of the ring coating head is φ17.5mm, and the workpiece lifting speed is 9.5mm / sec at the start of coating. The lifting speed is linearly decreased up to 10% of the length in the longitudinal direction. After reaching the position of 10% of the length in the longitudinal direction, the rising speed is fixed at 8.0 mm / sec, and after reaching the position of 90%, the rising speed is increased linearly, A developing roller was prepared in the same manner as in Example 13 except that the rising speed was set to 9.5 mm / sec at the end of the work.

  The rising speed of the workpiece is 11.5 mm / sec at the start of coating, and the rising speed is gradually decreased at a rate of 0.1 mm per second up to a position of 20% with respect to the longitudinal direction. After reaching the 20% position, the ascent speed is fixed at 10.0 mm / sec. After reaching the 80% position, the ascent speed is increased gradually at a rate of 0.1 mm per second. A developing roller was prepared in the same manner as in Example 1 except that the rising speed was set to 11.5 mm / sec at the end of coating.

Liquid silicone rubber material (molecular weight Mw = 100000) 70% by mass
Carbon black (Denka black powder, manufactured by Denki Kagaku Kogyo) 3% by mass
Carbon black (MA-11 manufactured by Mitsubishi Chemical) 7% by mass
Silica (Aerosil 50 from Nippon Aerosil) 7% by mass
Quartz (Pennsylvania Glass Sand Min-USil) 13% by mass
The above blend was mixed and defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material. Furthermore, 0.02 part of an isopropyl alcohol solution of chloroplatinic acid (platinum content 3% by mass) is added to 100 parts of this base material and mixed to obtain a mixture A, which is an organohydrogenpolysiloxane having a viscosity of 10 cps (SiH content). 1 part by weight) 1.5 parts was added and mixed to obtain a mixture B. The mixture A and the mixture B were set in the raw material tank 1 and the raw material tank 2, respectively, and sent to a static mixer using a pressure feed pump to mix the mixture A and the mixture B at a ratio of 1: 1.

  Using this material, the inner diameter of the ring coating head is 12.6 mm, the workpiece rising speed is 10.5 mm / sec at the start of coating, and rises linearly up to a position of 10% of the length in the longitudinal direction. Decreasing the speed, after reaching the position of 10% relative to the length in the longitudinal direction, the rising speed is fixed at 10.0 mm / sec, and after reaching the position of 90%, the rising speed is linearly At the end of coating, the rising speed was set to 10.5 mm / sec, and a liquid rubber material layer was formed around a φ8 mm cored bar so that the coating thickness was 2.0 mm and the length was 250 mm. Further, after coating, move quickly to the heater so as not to give an impact to the workpiece, rotate at 30 rpm in a horizontal state, and 4 minutes with an infrared heater (HYL25, manufactured by Hybek: workpiece heater distance 60 mm, output 780 W) A rubber roller having a maximum outer diameter of 12.0 mm was molded by heat curing, and then heat-treated at 200 ° C. for 4 hours in an electric furnace.

  The obtained rubber roller was formed with the outermost layer in the same manner as in Example 1 to prepare a charging roller.

(Comparative Example 1)
Liquid silicone rubber material (molecular weight Mw = 100000) 75% by mass
Carbon black (Denka Black powder, manufactured by Denki Kagaku Kogyo) 5% by mass
Silica (Nippsil LP manufactured by Nippon Silica Industry) 13% by mass
Quartz (Pennsylvania Glass Sand Min-USil) 7% by mass
The above blend was mixed and defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material.

  A conductive shaft is placed in a non-cylindrical mold having an inner diameter of 11.5 mm at the upper and lower ends inside the mold and an inner diameter of 12.0 mm at the middle of the mold, and a cavity formed in the mold The rubber material blended as described above was injected into the above. Subsequently, the mold was heated, and the injected rubber material was heated at 150 ° C. for 30 minutes to be cured. After cooling and demolding, a heat treatment was further performed at 200 ° C. for 4 hours to obtain a rubber material.

  However, when the rubber roller is removed from the mold, when the central part of the rubber roller reaches the upper end of the mold, excessive stress is applied to the rubber part, so air is injected between the rubber roller and the mold to remove the mold. The process was complicated.

(Comparative Example 2)
Millable type silicone rubber material (GE Toshiba Silicone YE3452UB)
The conductive shaft is set in a crosshead extrusion device, and while moving a predetermined amount of the rubber material, the moving speed of the conductive shaft is 3.0 mm / sec at both ends and 2.3 mm / sec at the center. The rubber material was molded on the conductive shaft. After molding, the mixture was immediately put into a heating furnace heated to 200 ° C. for 4 hours for vulcanization treatment.

  The obtained rubber roller was formed with a conductive resin layer by the same method as in Example 1 to prepare a developing roller.

  The measurement result of the shape shake at both ends of the rubber roller obtained at this time was 70 μm, which was large.

<Examples and evaluation results>
The runout shapes of the rollers of Examples 1 to 16 and Comparative Examples 1 and 2 were measured. The difference between the maximum value and the minimum value was determined for the rubber thickness at the end of the rubber roller.

◎: Rubber thickness maximum value-Minimum value is 30 μm or less ○: Rubber thickness maximum value-Minimum value is greater than 30 μm and 50 μm or less △: Rubber thickness maximum value-Minimum value is greater than 50 μm In addition, the rubber rollers molded in Examples 1 to 16 and Comparative Examples 1 and 2 are manufactured in Comparative Example of this Example as a developing roller or a charging roller using an electrophotographic laser printer (Canon, LBP-1310). The image was evaluated.

  The electrophotographic laser printer is an A4 vertical output machine, and has a recording medium output speed of 16 ppm and an image resolution of 1200 dpi.

The contact pressure of the developing roller with the photoreceptor and the amount of entry were adjusted so that the developer coating amount on the developing roller was 0.35 mg / cm ² .

  A developing roller was incorporated in the cartridge, and it was determined whether there was a problem with the formed image quality. Based on the judgment, evaluation was made according to the following criteria.

[Image Evaluation 1]
About the image obtained by said method, the density nonuniformity of the center part of an image and both ends was evaluated based on the following references | standards.

◎: Good that is not confirmed with the naked eye ○: There is a slight difference in density between the center and both ends of the image, but there is no practical problem at all △: There is a difference in density between the center and both ends of the image Although seen, there are problems in practical use [Image Evaluation 2]
For the image obtained by the above method, density unevenness at the developing roller pitch was evaluated based on the following criteria at both ends of the image.

◎: Good that is not confirmed with the naked eye ○: Density unevenness of the developing roller pitch is slightly seen at both ends of the image, but there is no practical problem at all △: Density unevenness of the developing roller pitch is evident at both ends of the image It is seen, but there is no problem in practical use

  From the result shown in Table 1, in Examples 1-16, it was a level which is satisfactory practically in shape shake and image evaluation.

It is a conceptual diagram which shows an example of the electrophotographic image forming apparatus of this invention. It is the schematic which shows the 1st apparatus with which the coating method of embodiment was applied. It is sectional drawing of an example of the rubber roller of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Photoconductor 22 Charging roller 23 Laser beam 24 Developing device 25 Developing roller 26 Developer supply roller 27 Developer control member 28 Developer 29 Transfer roller 30 Cleaning blade 31 Waste toner container 32 Fixing roller 33 Transfer paper 34 Developer container 35 Developing device DESCRIPTION OF SYMBOLS 1 Stand 2 Column 3 Ball screw 4 LM guide 5 Servo motor 6 Pulley 7 Bracket 8 Ring-shaped coating head 9 Workpiece holding shaft 10 Workpiece holding shaft 11 Supply port 12 Piping 13 Material supply valve 14 Linear guide 101 Conductive shaft Body 102 Conductive elastic layer 103 Conductive resin layer (surface layer)

Claims (11)

  In a method of manufacturing a rubber roller comprising a conductive shaft body and an elastic layer having a non-cylindrical cylindrical shape formed on the outer periphery of the conductive shaft body, a liquid rubber material at room temperature is coated in a ring shape on the shaft body A method for producing a rubber roller, comprising: a step of coating the rubber material while controlling a coating amount of the rubber material in a longitudinal direction by using a head, and having a non-cylindrical shape by curing the rubber material.   Installing the conductive shaft at the center of the ring of the ring-shaped coating head, supplying a constant amount of rubber material to the gap between the coating head and the conductive shaft through a slit provided in the coating head; and An elastic layer formed by curing the rubber material after the rubber material is coated on the shaft body by adjusting the speed of the conductive shaft body so as to have a non-right cylindrical shape. Item 2. A method for producing a rubber roller according to Item 1.   As a means for forming the non-cylindrical cylindrical portion of the rubber roller, when the rubber material is coated on the conductive shaft body, the moving speed of the conductive shaft body when the rubber material is coated is continuously increased. 3. The method for producing a rubber roller according to claim 1 or 2, wherein   4. The moving speed of the conductive shaft body is characterized in that a ratio of a moving speed between a maximum speed and a minimum speed, or a value of a minimum speed / maximum speed is 85% or more and 100% or less. The manufacturing method of the rubber roller in any one of.   In the rubber roller, the maximum thickness of the elastic layer after the rubber material is cured is greater than 2 mm and 6 mm or less, and the difference between the maximum value and the minimum value of the outer diameter in the rubber roller is the maximum thickness of the elastic layer. 5. The method for producing a rubber roller according to claim 1, wherein the rubber roller production method is 0% or more and 10% or less.   6. The method of manufacturing a rubber roller according to claim 1, wherein the rubber material has a maximum thickness of the elastic layer after curing of the rubber material of greater than 2 mm and 5 mm or less.   7. A rubber roller manufactured by the manufacturing method according to claim 1.   The rubber roller is a developing roller for visualizing an electrostatic latent image by forming a thin film of developer on the surface of the rubber roller and attaching a latent image developer to the surface of the latent image holding member from the thin film of the developer. The rubber roller according to claim 7.   9. The development according to claim 8, wherein the electrostatic latent image is visualized by bringing an electrostatic holding body that holds the electrostatic latent image into contact with a developing roller that carries a non-magnetic developer on the surface thereof. A developing method using a roller.   A developing roller is mounted, a thin layer of developer is formed on the surface of the developing roller, the developer roller is brought into contact with the photosensitive member, and the developer is supplied to the surface of the photosensitive member. An electrophotographic process cartridge for forming a visible image on an electrophotographic process cartridge, wherein the developing roller is the developing roller according to claim 8.   A developing roller is mounted, a thin layer of developer is formed on the surface of the developing roller, the developer roller is brought into contact with the photosensitive member, and the developer is supplied to the surface of the photosensitive member to thereby supply the developer surface. The image forming apparatus according to claim 8, wherein the developing roller is the developing roller according to claim 8.

Images