JP2006293015A - Elastic roll and method for manufacturing same, electrophotographic process cartridge, and image forming apparatus having elastic roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method of an elastic roll having satisfactory dimensional accuracy without using dies in a method for forming a rubber material as a coating material on the circumference of a shaft core body and curing the material by vulcanization. <P>SOLUTION: In the method for manufacturing the elastic roll, the coating filming forming object having the satisfactory dimensional accuracy is obtained by coating and forming a material in the form of a non-Newtonian liquid in which the yield stress of the coating material is 50 Pa to 600 Pa and thixotropic index is 2.0 to 6.5 by using a coating head of a cylindrical shape. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cylindrical elastic roll used in an electrophotographic apparatus and a method for manufacturing the same. Specifically, it is a manufacturing method in which an elastic body is provided around a shaft core body without using a molding die, and a liquid rubber material is directly, well and uniformly molded around the shaft core body.

  In a printer using an electrophotographic system, a photosensitive drum as an image forming body is uniformly charged by a charging roll, and an electrostatic latent image is formed by a laser or the like. Next, the developer in the developing container is uniformly applied on the developing roll with a proper charge by the developer coating roll and the developer regulating member, and the developer is transferred (developed) at the contact portion between the photosensitive drum and the developing roll. Done. Thereafter, the developer on the photosensitive drum is transferred to a recording sheet by a transfer roll and fixed by heat and pressure (a pressure roll and a fixing roll), and the developer remaining on the photosensitive drum is removed by a cleaning blade, and a series of The process is complete.

  In an electrophotographic apparatus, for example, in the case of a developing roll, the developing roll is always in pressure contact with the photosensitive drum and the developer regulating member, and development is performed between the developing roll and the photosensitive drum, and between the developing roll and the developer regulating member. It is in pressure contact with the agent. The developer that is not transferred to the photosensitive drum is peeled off by the developer coating roll, returned to the developing container again, stirred in the container, and conveyed again onto the developing roll by the developer coating roll. As a result of repeating these steps, the developer is subjected to great stress. Accordingly, for the purpose of reducing the stress on the developer, a developing roll made of a material composed of a low-hardness elastic body has been used.

  In the case of a developing roll or a charging roll, since it always rotates in contact with other members, it is necessary to keep the contact state stable, and therefore high dimensional accuracy is required as a roll. If the contact state cannot be kept stable, the supply amount of the developer varies and the pressure distribution on the photosensitive drum varies, which adversely affects the image. The fixing roll and the pressure roll are also required to have high accuracy as the image quality is improved and the speed of the apparatus is increased. If the dimensional accuracy is poor, the stress applied to other members increases, which causes accelerated wear and deterioration.

Due to these demands, a molding method using a mold is used to mold an elastic roll with good dimensional accuracy. For example, a mold forming technique in which one or a plurality of reservoir grooves are provided in the shaft core receiving portion is disclosed (see Patent Document 1). According to this, it is said that good molding can be performed without reducing the dimensional accuracy of the roll by letting the material escape to the reservoir groove. Thus, in order to mold a highly accurate elastic roll, a molding method using a mold is common. However, in the mold forming technology, it is inevitable that the production equipment is expensive because a large number of highly accurate molds are required.
Also, in mold molding, production facilities are large because there are many processes such as mold assembly, preheating, casting, primary vulcanization, cooling, mold separation, demolding, and secondary vulcanization and processes at the required time. There is a current situation such as.

  Conventional methods for forming a liquid material on the surface of a cylindrical body without using a mold include, for example, a spray coating method, a dip coating method, a roll coating method, a blade coating method, and a quantitative coating method using a dispenser (Patent Document 2). Various methods such as a ring coating method have been studied. A film having a desired function is formed on the surface of the cylindrical body in accordance with various uses of the elastic roll. Particularly in recent years, in order to express such a desired function, a coating film from a uniform thin layer to a thickness of about several millimeters is required, and coating liquids to be applied are diversified. Along with this, some of the coating liquids change from low viscosity to high viscosity. For this reason, in the conventional coating method, the coating range of such coating liquids cannot be covered.

For example, the spray coating method can be used only for a coating solution having a low viscosity. If the viscosity of the coating solution is high, atomization of the coating solution becomes difficult. In the blade coating method and the roll coating method, for example, a blade or roll is disposed in the axial direction of the cylinder to be applied, and the coating liquid is applied by the blade or roll while rotating the cylinder. After rotating the cylindrical body by one to several revolutions, the blade or roll is moved backward to complete the coating. When the blade or roll is retracted at the end of coating, a part of the coating film on the cylindrical body is thicker than the other part due to the viscosity of the coating liquid, especially when the viscosity of the coating liquid is high. The portion becomes unrecoverable during the subsequent leveling of the coating film, and a uniform coating film cannot be obtained.
In the dip coating method, the problem of non-uniformity of the coating film in the spray coating method, the blade coating method, the roll coating method, etc. is improved, but the control of the coating film thickness is a property of the coating liquid, for example, coating. Since it is governed by the viscosity, surface tension and density of the liquid, and other temperatures, it is difficult to adjust the physical properties of the coating liquid, and it is difficult to apply a thin wall when the coating liquid has a high viscosity. For this reason, in the spray coating method, blade coating method, roll coating method, and dip coating method, a high-viscosity coating solution is diluted with a solvent, and the coating solution is applied in a state where the coating solution is lowered to the viscosity required for coating. In the process after coating, the solvent used for diluting the coating solution must be removed by, for example, evaporation to form a coating film.

On the other hand, a ring coating method is disclosed as a method for directly coating a high viscosity material (see Patent Document 3). By using a method in which the coating liquid is applied to the surface of the cylindrical body with the center line of the cylindrical body parallel to the horizontal direction, the coating process is limited by the viscosity of the coating liquid and the film thickness of the coating film. The present invention provides a coating method capable of forming a good and uniform coating film by removing and applying the coating liquid directly onto the surface of the cylindrical body with a simpler apparatus.
JP 2000-006163 A JP-A-8-89867 JP 2003-190870 A

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and an object of the present invention is to provide a method for producing a coating film formed with good dimensional accuracy without using a mold even when the thickness of the coating film is increased. It is in providing the elastic roll obtained by the manufacturing method.

  The present invention relates to a method for producing an elastic roll obtained by forming a coating around a cylindrical body with a coating material containing a rubber material and vulcanizing and curing, wherein the yield stress of the coating material is 50 Pa or more and 600 Pa or less, and a thixotropic index A method for producing an elastic roll, characterized in that a non-Newtonian liquid material having a thickness of 2.0 or more and 6.5 or less is formed by coating using a cylindrical coating head.

  Moreover, it is the manufacturing method of the said elastic roll characterized by the thickness of the coating material shape | molded being 0.5 mm or more and 6.0 mm or less.

  Furthermore, it is the manufacturing method of the said elastic roll characterized by the thickness of the coating material shape | molded exceeding 2.0 mm and 4.0 mm or less.

  In the method for producing the elastic roll, the covering material contains at least a material having conductivity.

The method for producing an elastic roll, wherein the conductive material in the coating material is in the form of a filler.
The elastic roll is formed by the manufacturing method.

  The elastic roll is at least one of a fixing roll and a pressure roll of an electrophotographic apparatus.

  A conductive roll formed by the manufacturing method.

  The conductive roll is at least one of a developing roll and a charging roll of an electrophotographic apparatus.

  An electrophotographic process cartridge comprising a charging roll, wherein the charging roll is in contact with a photosensitive drum to supply charges to the surface of the photosensitive drum, wherein the charging roll is the charging roll. It is a cartridge.

A developing roll is mounted, a thin layer of developer is formed on the surface of the developing roll, the developer roll is brought into contact with the image forming body, and the developer is supplied to the surface of the image forming body. In an electrophotographic process cartridge for forming a visible image on the surface of the formed body,
The electrophotographic process cartridge is characterized in that the developing roll is the developing roll.

A developing roll is mounted, a thin layer of developer is formed on the surface of the developing roll, the developer roll is brought into contact with the image forming body, and the developer is supplied to the surface of the image forming body. In the image forming apparatus for forming a visible image on the surface of the formed body,
The image forming apparatus is characterized in that the developing roll is the developing roll.

  According to the molding method of the present invention, there is no need for a large number of highly accurate molds as in the conventional mold molding, so that the production equipment cost can be greatly reduced and the number of processes is small. For this reason, the production equipment is reduced in size. With these, it is possible to form an elastic roll with good dimensional accuracy at low cost.

When using a liquid material to increase the coating film thickness, the material viscosity at a shear rate (0.1 s ^-1 to 1 s ^-1 ) measured with a general rotational viscometer is high. By trying to control, the shape retention after coating was going to be improved. However, the ability to retain the shape has a certain degree of correlation with the material viscosity in the shear rate region that can be measured with a rotational viscometer, but further improvement was required when trying to control the dimensions with high accuracy.

  As a result of diligent research to achieve the above-mentioned object, the present inventors have controlled the yield stress value at which structural destruction of the coating material occurs and the shear rate dependence of the material viscosity (thixotropic index) within an appropriate range, It has been found that the above-mentioned problems can be solved when combined with a manufacturing method using a cylindrical coating head.

  According to the present invention, when a non-Newtonian liquid material having a yield stress of 50 Pa or more and 600 Pa or less and a thixotropic index of 2.0 or more and 6.5 or less is used as a coating material, the coating thickness is conventionally increased. Further, it is characterized in that a film-formed product with good dimensional accuracy can be obtained even when the thickness is increased.

The thixotropy index represents the amount by which the viscosity changes with respect to the shear rate.
When the thixotropy index is 1, it indicates a Newtonian liquid, and when the thixotropy index is other than 1, it indicates a non-Newtonian liquid.

A more preferable range of the yield stress is 100 Pa or more and 400 Pa or less. When the yield stress is in the range of 50 Pa or more and 600 Pa or less, the dimensional accuracy with respect to the coating thickness can be maintained and the balance with the smoothness of the coating surface can be achieved in the best condition. When the yield stress exceeds 600 Pa The stress necessary for causing the structural breakdown of the material is too large, causing problems such as generation of streaks or irregularities on the surface after coating. If it is less than 50 Pa, the yield stress is too small for the gravity and the shape after the coating is formed cannot be maintained. Therefore, the outer diameter dimensional difference with respect to the coating thickness of the heat-cured elastic roll becomes large. Can not withstand use. A dimensional system that can be suitably used as an elastic roll is a case where the dimensional difference is within 3% of the outer diameter of the roll, although it depends on the grade and durability of the apparatus. If it exceeds 3%, the stress applied to the other members is biased, which may cause accelerated wear and deterioration of the portion where the stress is large, or cause image defects due to the loss of the balance of charge and developer supply.

  A more preferable range of the thixotropy index is 2.5 or more and 5.0 or less.

  When the more preferable range of the thixotropic index is in the range of 2.0 or more and 6.5 or less, the balance between the flow stability of the material with respect to the change in shear rate and the stable supply of the material can be achieved in the best condition.

  When the thixotropy index exceeds 6.5, the fluidity of the raw material with respect to the shear rate change becomes unstable, and the dimensional stability of the molded coating film is deteriorated. When the yield stress is less than 2.0, when the yield stress is controlled within a predetermined range, the material viscosity is too high at the shear rate in the piping during material transportation, and the apparatus is overloaded with high load. Difficulties arise.

  When the yield stress of the coating material is 50 Pa or more and 600 Pa or less and the thixotropy index is 2.0 or more and 6.5 or less, it is possible to obtain a coating film formed with good dimensional accuracy.

  When the thickness of the coating to be molded is 6.0 mm or less, no dripping occurs and dimensional stability can be maintained. If the thickness is 0.5 mm or more, the problem that the material cannot be molded satisfactorily can be avoided because the shearing force applied to the material is increased and the recovery stability of the structurally broken material is hindered. The thickness of the coating to be molded is preferably 0.5 mm or more and 6.0 mm or less. More preferably, it is more than 2.0 mm and 4.0 mm or less.

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

  The elastic roll of the present invention has an elastic layer 102 around a shaft core body 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. Details of each component will be described below.

(Shaft core)
The shaft body of the elastic roll 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 core 1, for example, alloys such as iron, aluminum, titanium, copper and nickel, and alloys of these metals including stainless steel, duralumin, brass and bronze, carbon black and carbon It is also possible to use a known material exhibiting rigidity and conductivity, such as a composite material in which fibers are 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 shaft core is usually in the range of 4 to 10 mm.

[Elastic layer]
A conductive coating layer can be formed on the outer periphery of the conductive shaft core. Various liquid rubbers can be used as a preferable material for forming the conductive coating layer. Specifically, from rubber materials such as diene rubber, silicone rubber, polysulfide rubber, urethane rubber, etc., these rubbers can be used as long as they give desired mechanical properties when molded by adding other ingredients The materials can be used alone or in admixture of two or more.

[Liquid silicone rubber]
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. Although other liquid rubbers can be used in the method of the present invention, the most preferred silicone rubber will be described in detail, but other known liquid rubbers can also be used.

  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.

  The molecular weight of the base polymer is an important characteristic value for controlling the material yield stress and the thixotropy index. By selecting the molecular weight of the polymer or blending polymers having different molecular weights, it is possible to control the target characteristic value. If the average molecular weight is 10,000 or more, the polymer is large enough to take in the added filler, so that the desired yield stress is obtained. Moreover, if it is 1 million or less, a viscosity is appropriate and sufficient filler quantity can be added and it is further possible to disperse | distribute a filler uniformly.

  The alkenyl group of the organopolysiloxane is a site that reacts with the active hydrogen of the organohydrogenpolysiloxane to form a crosslinking point, and the type thereof is not particularly limited, but for reasons such as high reactivity with active hydrogen. , Vinyl group and allyl group are preferable, and vinyl group is particularly preferable.

  Organohydrogenpolysiloxane serves as a crosslinking agent for addition reaction in the curing process, and the number of silicon-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.

[Various additives contained in liquid silicone rubber]
The liquid silicone rubber can contain, for example, chloroplatinic acid hexahydrate as a polyorganohydrogensiloxane crosslinking catalyst. Moreover, the transition metal compound which shows a catalytic action in hydrosilylation reaction can also be used as a crosslinking catalyst. Specific examples thereof include Fe (CO) 5, Co (CO) 8, RuCl3, IrCl3, [(olefin) PtCl2] 2, vinyl group-containing polysiloxane-Pt complex, H2PtCl6 · 6H2O, L2Ni (olefin), L4Pd, L4Pt, L2NiCl2 (wherein L = PPh3 or PR′3, where P represents phosphorus, Ph represents a phenyl group, and R ′ represents an alkyl group). Among these, platinum, palladium, and rhodium-based transition metal compound catalysts are preferable.

  In the case of a platinum-based metal compound catalyst, the compounding amount of the catalyst is preferably 1 mass ppm or more and 100 mass ppm or less as platinum in the liquid silicone rubber (including various compounds), but is not limited to this range. It is appropriately selected depending on the target pot life, curing time, product shape and the like.

  The liquid silicone rubber can contain an unsaturated alcohol such as 1-ethynyl-cyclohexanol or phenylbutynol as a curing reaction retarder. The blending amount of the curing reaction retarder can be appropriately selected according to the target pot life, curing time, and product shape, for example, in the range of 0.05 to 0.5 parts by mass with respect to 100 parts by mass of the organopolysiloxane.

  When using liquid rubber other than silicone rubber, known additives can be added as necessary.

  In order to adjust the curing speed of the liquid rubber, it is effective to adjust the types and amounts of the catalyst and the curing reaction retarder.

[Conducting agent and filler]
Examples of the conductive agent that can be included in the liquid rubber include conductive plasticizers, ion conductive materials such as KSCN, LiClO4, NaClO4, and quaternary ammonium salts, and metal-based metals such as aluminum, palladium, iron, copper, and silver. 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 tin oxide, antimony oxide, indium oxide and molybdenum oxide on the surface of appropriate particles; Zinc, aluminum, gold, silver, copper, chromium, cobalt, iron, lead, platinum, rhodium powder deposited by electrolytic treatment, spray coating, mixed shaking; acetylene black, ketjen black, PAN carbon black And carbon powders such as pitch-based 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 roll used in electrophotography cannot be obtained.

  Examples of reinforcing fillers and extenders that can be included in the liquid rubber include fumed silica, wet silica, quartz fine powder, diatomaceous earth, carbon black, zinc oxide, basic magnesium carbonate, activated calcium carbonate, and silicic acid. Examples thereof include magnesium, 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 roll used in electrophotography cannot be obtained.

  The type and amount of filler and conductive agent are important in controlling the material yield stress 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 stress 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.

[Plasticizer]
Examples of plasticizers that can be included in the liquid rubber include polydimethylsiloxane oil, diphenylsilanediol, trimethylsilanol, phthalic acid derivatives, adipic acid derivatives, and softening agents such as lubricating oil, process oil, and coal tar. Castor oil, anti-aging agents such as phenylenediamines, phosphates, quinolines, cresols, phenols, dithiocarbamate metal salts, and heat-resistant agents such as iron oxide, cerium oxide, potassium hydroxide , 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.

[Distribution method]
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.

[Surface layer]
In the present invention, a resin layer is further formed as a surface layer on the surface of the conductive elastic base layer formed as described above for the purpose of imparting charging characteristics to the toner, imparting a surface shape, adjusting resistance, and the like. You can also. 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, since the surface of the roll is preferably a rough surface, 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 photosensitive drum, and is preferably 50 μm or less from the viewpoint of preventing the roll from becoming hard and causing fusion. . More preferably, it is 10-30 micrometers.

  Unevenness on the roll 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).

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

    FIG. 1 is a schematic view showing an apparatus to which a coating method according to an embodiment of the present invention is applied.

  As an example, in the coating apparatus of this embodiment, as shown in FIG. 1, 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 so that 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.
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 shaft core body 101.

Further, a bracket 7 is mounted on the LM guide 3, and a work lower holding shaft 9 for holding and fixing the roll shaft core 101 is mounted on the bracket 7 substantially vertically, and the shaft core 101 of the roll on the opposite side is mounted on the bracket 7. The center axis of the workpiece upper holding shaft 10 to be held is attached to the upper part of the bracket 7, and the workpiece upper holding shaft is arranged so as to be substantially concentric with the workpiece lower holding shaft 9 to hold the shaft core body. Yes. Further, the center axis of the ring-shaped coating head 8 (see FIG. 2) is respectively supported so as to be parallel to the movement direction of the workpiece lower holding shaft 9 and the workpiece upper holding shaft 10, and the workpiece lower holding shaft 9 and When the workpiece holding shaft 10 is moved up and down, the central axis of the discharge port, which is an annular slit opened inside the coating head 8, and the workpiece holding shaft 9 and the workpiece holding shaft 10 are substantially concentric. It has been adjusted to become. With such a configuration, the central axis of the discharge port formed in the annular slit of the coating head 8 can be aligned with the central axis of the shaft core body so as to be substantially concentric with the inner peripheral surface of the ring-shaped coating head and the shaft. A uniform gap is formed between the outer peripheral surface of the core body 101.
The coating solution supply port 11 is connected to a material supply valve 13 via a coating solution 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, and is configured to discharge a fixed amount (a constant amount per unit time) of the coating liquid.

  FIG. 2 is a sectional view of a ring-shaped coating head used in the manufacturing method of the present invention. The ring-shaped coating head used in the manufacturing method of the present invention is composed of a head upper portion 201 and a head lower portion 202 formed of a material such as metal, and is used by being fixed as shown in FIG. The raw material entered from the material injection port 203 is filled in the direction of 360 degrees through the material flow path 204 in the head, and is discharged from the material discharge port 205.

  FIG. 5 schematically shows an example of the structure of the elastic roll with a surface layer formed by the manufacturing method of the present invention. The elastic roll formed by the manufacturing method of the present invention has a shaft core body 101 that is usually formed of a conductive material such as metal as a shaft core body at the center, and an elastic layer on the outer peripheral surface of the shaft core body 101. The (base layer) 102 is fixed, and the conductive surface layer (surface layer) 103 is laminated on the outer peripheral surface of the elastic layer 102.

  FIG. 6 schematically shows a developing device using the elastic roll of the present invention as a developing roll, and an image forming apparatus using the elastic roll as at least one of a developing roll, a charging roll, a transfer roll, a fixing roll, and a pressure roll. It is sectional drawing which shows a structure.

  In this image forming apparatus, the photosensitive drum 21 as a latent image carrier rotates in the direction of arrow A, and the region of the photosensitive drum 21 that has passed therethrough is uniformly charged by a charging roll 22 for charging the photosensitive drum 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 drum 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 visualized (visualized) 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 photosensitive drum 21 is transferred onto a transfer paper 33 such as paper by a transfer roll 29. The paper 33 to which the toner image has been transferred is fixed by the fixing roll 32 and the pressure roll 36, and is discharged out of the apparatus, thus completing the printing operation. The transfer roll 33 is a region that holds the toner image on the photosensitive drum 21 by pressing the transfer paper 33 from the back surface to the region holding the toner image on the photosensitive drum 21 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 photosensitive drum 21 by automatically inserting the transfer paper 33 into the portion where the photosensitive drum 21 and the transfer roll 29 are in contact with each other. Achieved.

  On the other hand, the transfer residual toner remaining on the photosensitive drum 21 without being transferred is scraped off by the cleaning blade 30 and stored in the waste toner container 31, and the above process is repeated on the cleaned photosensitive drum 21. The same image can be copied or a new image can be transferred.

  In the illustrated example, the developing device 35 is located opposite to the photosensitive drum 21 and is located in the opening extending in the longitudinal direction in the developing container 34 and the developing device 34 containing the non-magnetic toner 28 as a one-component developer. And a developing roll 25 as a developer carrying member, and the electrostatic latent image on the photosensitive drum 21 is developed and visualized.

  The developing roll 25 is in contact with the photosensitive drum 21 with a contact width. In the developing device, the developer supply roll 26 having elasticity is abutted on the upstream side in the rotation direction of the developing roll 25 with respect to the abutting portion of the elastic blade 27 with the surface of the developing roll 25 in the developing container 34, and It is supported rotatably. The developer supply roll 26 has a foamed skeleton-like sponge structure or a fur brush structure in which fibers such as rayon and nylon are planted on a core metal, and supplies toner 28 to the development roll 25 and peels off undeveloped toner. It is preferable from the point of taking. In the present embodiment, a developer supply roll 26 having a diameter of 16 mm provided with a polyurethane foam on a core metal is used.

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

  Normally, the developing container 34 and the developing roll 25, the developer supply roll 26, the toner 28, the elastic blade 27, etc. 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 a photosensitive drum 21, a waste toner container 31, and a charging roll 22 is also used.

<Various measurement methods>
<Molecular weight measuring method> The measuring method of the molecular weight by GPC of silicone rubber is described below.
Molecular weight of chromatogram by gel permeation chromatography (GPC)
Mn, Mw, Mz) are measured under the following conditions. The column was stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) was added to the column at this temperature as a solvent at a rate of 1 per minute.
The sample is poured at a flow rate of ml, and about 50 to 200 μl of a THF sample solution of resin adjusted to a sample concentration of 0.05 to 0.6% by mass is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts (retention time). As a standard polystyrene sample for preparing a calibration curve, for example, Tosoh Corporation or Pressure Chemical Co.
. The molecular weight is 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10
⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and at least about 10 standard polystyrene samples are used. Is appropriate. An RI (refractive index) detector is used as the detector.

As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, shodex GPC KF-801, 802, 803, 804, 8 manufactured by Showa Denko K.K.
05, 806, 807 combination or μ-styrgel500 manufactured by Waters
, 103, 104, and 105.

<Yield stress measurement method>
The yield stress measurement method for liquid rubber materials using a viscoelasticity measuring device is described below.
As a viscoelasticity measuring device, RheoStress 600 manufactured by Haake was used.

About 1 g of material was sampled and placed on the sample stage, the cone plate was gradually approached, and a measurement gap was set at a position of about 50 μm from the sample stage (a thing with a diameter of 35 mm and an inclination angle of 1 ° was used for the cone plate). ). At that time, the material extruded around was removed cleanly so as not to affect the measurement.
The temperature of the platen was set so that the material temperature was 25 ° C., and the sample was left for 10 minutes after setting the sample, and then the measurement was started.
The stress applied to the sample is varied from 180 Pa to 50000 Pa (frequency is 1 Hz) over 180 seconds, and changes in G 'storage elastic modulus, G "loss elastic modulus, and phase difference tan δ at that time Measurement was performed at 32 points, G 'was initially a constant value in the linear viscoelastic region, and then the stress value at the point where G' storage elastic modulus and G "loss elastic modulus intersect was read and used as the yield stress.

<Thixotropic index: TI value>
The following describes how to determine the thixotropy index of a liquid rubber material using a rotational viscometer.
RE550U manufactured by Toki Sangyo Co., Ltd. was used as the rotational viscometer.
About 0.25 mL of the sample was set on the sample stage, and pretreatment was performed at 10 rpm for 30 seconds using a cone rotor with R9.7 and an inclination angle of 3 °. Immediately after the end of the pretreatment, the shear rate (s ^-1 ) was measured under the conditions of 0.2 for 100 sec, 0.4 for 50 sec, 1 for 30 sec, 2 for 30 sec, 4 for 30 sec, and 10 for 30 sec. At this time, the thixotropic index was obtained by dividing the viscosity measured at the shear rate 1 by the viscosity measured at the shear rate 10.

<Measurement of outer diameter and coating thickness>
The roll was rotated with the shaft core as the rotation axis, and a non-contact laser length measuring device (LS-5000 manufactured by Keyence) was installed perpendicular to the rotation axis, and the outer diameter of the elastic roll was measured. Using the end face of the shaft core as a reference, the distance to the outer peripheral surface of the elastic roll was measured to obtain the coating thickness (elastic body thickness).

  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.

<Example 1>
[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.
In the measurement of the yield stress and the thixotropy index described in the claims, the measurement value of the mixture A and the mixture B mixed at a ratio of 1: 1 was used as the measurement value of the coating material.

〔Production method〕
For the shaft core, an iron surface with chemical nickel plating was used, and a primer was applied to the surface (trade name: DY39-051: manufactured by Toray Dow Corning Silicone), and 150 degrees for 30 minutes in an electric furnace. Heat treatment was performed. The primer core (workpiece) after primer processing is placed on the ring coater work holding shaft, clamped by the upper holding shaft 10 and the lower holding shaft, the work is lowered to the coating start position and stopped, and the work rises Simultaneously with the start, the material was discharged from the ring coating head at a constant discharge amount, and a liquid rubber material layer having a constant thickness was formed around the work.

Next, while rotating the workpiece after coating in a horizontal state, it was irradiated with an infrared heater for 5 minutes and cured by heating to form a rubber elastic layer. 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 elastic layer.
Liquid silicone rubber material (molecular weight Mw = 100,000) 70% by mass
(Toray Dow Corning Silicone)
Carbon black (Denka black powder manufactured by Denki Kagaku Kogyo) 3% by mass
Carbon black (Mitsubishi Chemical product name: MA-11) 7% by mass
Silica (made by Nippon Aerosil Co., Ltd .: Trade name: AEROSIL50) 7% by mass
Quartz (Pennsylvania Glass Sand: Trade name 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 having a yield stress of 50 [Pa] and a thixotropy index (hereinafter referred to as TI value) of 2.01. 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) 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, ring coating head inner diameter φ12.6 mm, workpiece lifting speed 10 mm / sec, material discharge rate 720 mm ³ / sec, coating around φ8 mm cored bar, coating thickness 2.0 mm, length 250 mm A liquid rubber material layer was formed so that Furthermore, 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 4 minutes. An elastic roll with a diameter of 12 mm was formed by heat curing, and then heat-treated at 200 ° C. for 4 hours in an electric furnace.

(Formation of surface layer)
100 parts by mass of polyurethane polyol prepolymer (trade name: Takelac TE5060; manufactured by Mitsui Takeda Chemical)
Isocyanate 77 parts by mass (trade name: Coronate 2521; manufactured by Nippon Polyurethane Co., Ltd.)
24 parts by mass of carbon black (trade name: MA100; manufactured by Mitsubishi Chemical Corporation)
24 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. An elastic roll 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, and the conductive surface layer is laminated on the outer peripheral surface of the conductive elastic layer. After forming a conductive surface layer having a surface roughness (Rz) of 9.2 μm, 10 mm was cut from both ends of the rubber to form a developing roll, which was incorporated into an image forming apparatus for image evaluation.

<Example 2>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 80% by mass
Carbon black (Denka black powder made by Denki Kagaku Kogyo) 7% by mass
Silica (made by Nippon Aerosil, trade name: AEROSIL50) 13% by mass
The above blend was mixed and degassed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 210 [Pa] and a TI value of 4.82.
In the same manner as in Example 1, mixture A and mixture B were mixed at a ratio of 1: 1.

  Using this material, ring coating head inner diameter φ12.6 mm, workpiece lifting speed 10 mm / sec, material discharge rate 960 mm3 / sec, coating around φ6 mm cored bar, coating thickness 3.0 mm, length 250 mm A liquid rubber material layer was formed as described above. Furthermore, 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 4 minutes. An elastic roll having a diameter of 12 mm was formed by heat curing.

  Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 3>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 60% by mass
Liquid silicone rubber material (molecular weight Mw = 500,000) 30% by mass
(Toray Dow Corning Silicone)
Carbon black (product name MA-11, manufactured by Mitsubishi Chemical Corporation) 5% by mass
Silica (made by Nippon Aerosil, trade name: AEROSIL380) 5% by mass
The above blend was defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 600 [Pa] and a TI value of 6.5.

  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 was coated at an inner diameter of φ21.0 mm, a workpiece lifting speed of 10 mm / sec, a material discharge rate of 2960 mm3 / sec, and a coating thickness of 6.0 mm and a length of 250 mm around a φ8 mm cored bar. A liquid rubber material layer was formed as described above. 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 .: 60 mm workpiece heater distance, output 780 W) for 6 minutes. An elastic roll having a diameter of 20 mm was formed by heat curing.
In order to improve releasability on the surface of this roll, a PFA (copolymer of tetrafluoroethylene and perfluoroalkylpinyl ether) solution was spray-coated to provide a 50 μm fluororesin layer. The created roll was used as a fixing roll and incorporated in an image forming apparatus for image evaluation.

<Example 4>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 80% by mass
Carbon black (product name: MA-100, manufactured by Mitsubishi Chemical) 8% by mass
Silica (made by Nippon Aerosil, trade name: AEROSIL 50) 12% by mass
The above blend was mixed and defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 140 [Pa] and a TI value of 2.8.

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

  Using this material, coating is performed with a ring coating head inner diameter of 12.6 mm, workpiece lifting speed of 10 mm / sec, material discharge rate of 720 mm3 / sec, and a liquid rubber having a thickness of 2.0 mm and a length of 250 mm around a φ8 mm cored bar. A material layer was formed. Furthermore, 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 4 minutes. An elastic roll having a diameter of 12 mm was formed by heat curing.

  Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 5>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 50% by mass
Liquid silicone rubber material (molecular weight Mw = 500,000) 30% by mass
Carbon black (Denka black powder manufactured by Denki Kagaku Kogyo) 3% by mass
Carbon black (product name: MA-11, manufactured by Mitsubishi Chemical Corporation) 7% by mass
Silica (Product name: AEROSIL 50, manufactured by Nippon Aerosil) 7% by mass
Quartz (Pennsylvania Glass Sand, trade name Min-USil) 3% by mass
The above blend was mixed and defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 350 Pa and a TI value of 2.5.

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

  Using this material, ring coating head inner diameter φ16.8 mm, workpiece lifting speed 10 mm / sec, material discharge rate 1680 mm3 / sec, coating around φ8 mm cored bar, coating thickness 4.0 mm, length 250 mm A liquid rubber material layer was formed as described above. 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 An elastic roll having a diameter of 16 mm was formed by heat curing.

  Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 6>
Using the same mixture A and mixture B as in Example 1, an elastic roll was molded under the following conditions.
Ring rubber coating material with inner diameter of φ12.6mm, workpiece lifting speed of 10mm / sec, material discharge rate of 200mm3 / sec, and liquid rubber material around φ11mm cored bar with coating thickness of 0.5mm and length of 250mm A layer was formed. Furthermore, 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 4 minutes. An elastic roll having a diameter of 12 mm was formed by heat curing.
Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 7>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 80% by mass
Carbon black (Denka Black powder, manufactured by Denki Kagaku Kogyo) 4% by mass
Silica (made by Nippon Aerosil, trade name AEROSIL 50) 16% by mass
The above blend was defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 400 Pa and a TI value of 2.1.
In the same manner as in Example 1, mixture A and mixture B were mixed at a ratio of 1: 1.
Using this material, an elastic roll having a diameter of 12 mm was formed in the same manner as in Example 2.
Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 8>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 80% by mass
Carbon black (Denka black powder made by Denki Kagaku Kogyo) 6% by mass
Silica (made by Nippon Aerosil, trade name: AEROSIL50) 14% by mass
The above blend was defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 400 Pa and a TI value of 2.5.

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

  Using this material, an elastic roll having a diameter of 12 mm was formed in the same manner as in Example 2.

  Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 9>
Liquid silicone rubber material (molecular weight Mw = 100,000) 50% by weight Liquid silicone rubber material (molecular weight Mw = 500,000) 30% by weight
Carbon black (Denka black powder made by Denki Kagaku Kogyo) 6% by mass
Carbon black (Mitsubishi Chemical, trade name MA-11) 9% by mass
Silica (Nippon Aerosil, trade name: AEROSIL200) 5% by mass
The above blend was mixed and degassed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 400 [Pa] and a TI value of 5.
In the same manner as in Example 1, mixture A and mixture B were mixed at a ratio of 1: 1.
Using this material, an elastic roll having a diameter of 12 mm was formed in the same manner as in Example 2.
Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 10>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 50% by mass Liquid silicone rubber material (Molecular weight Mw = 500,000) 34% by mass Carbon black (Denka Black powder form by Denki Kagaku Kogyo) 6% by mass
Carbon black (Made by Mitsubishi Chemical, trade name: MA-11) 5% by mass
Silica (Nippon Aerosil, trade name: AEROSIL200) 5% by mass
The above blend was defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 400 Pa and a TI value of 6.5.
In the same manner as in Example 1, mixture A and mixture B were mixed at a ratio of 1: 1.
Using this material, an elastic roll having a diameter of 12 mm was formed in the same manner as in Example 2.
Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 11>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 75% by mass Carbon black (Denka Black powder, manufactured by Denki Kagaku Kogyo) 3% by mass
Carbon black (product name: MA-11, manufactured by Mitsubishi Chemical Corporation) 7% by mass
Silica (product name: AEROSIL50, manufactured by Nippon Aerosil) 5% by mass
Quartz (Pennsylvania Glass Sand, trade name: Min-USil) 10% by mass The above composition is mixed and degassed for 30 minutes using a planetary mixer, and a silicone rubber having a yield stress of 55 [Pa] and a TI value of 6.4 A base material was obtained.
In the same manner as in Example 1, mixture A and mixture B were mixed at a ratio of 1: 1.
Using this material, a φ12 mm elastic roll was formed in the same manner as in Example 1.
Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 12>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 50% by mass Liquid silicone rubber material (Molecular weight Mw = 500,000) 34% by mass Carbon black (Denka Black powder form by Denki Kagaku Kogyo) 6% by mass
Carbon black (Made by Mitsubishi Chemical, trade name: MA-11) 5% by mass
Silica (product name: AEROSIL50, manufactured by Nippon Aerosil) 5% by mass
The above blend was defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 400 Pa and a TI value of 6.5.
In the same manner as in Example 1, mixture A and mixture B were mixed at a ratio of 1: 1.
Using this material, a φ12 mm elastic roll was formed in the same manner as in Example 1.
Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Example 13>
In order to increase the releasability on the surface of the elastic roll obtained in the same manner as in Example 3, a PFA (copolymer of tetrafluoroethylene and perfluoroalkylpinyl ether) solution was spray-coated, and a 50 μm fluororesin was added. Provided. The created roll was used as a pressure roll and incorporated into an image forming apparatus for image evaluation.

<Example 14>
The roll created in Example 1 was used as a charging roll and incorporated in an image forming apparatus, and image evaluation was performed.

<Comparative Example 1>
Liquid silicone rubber material (molecular weight Mw = 100,000) 75% by mass
Carbon black (Denka black powder, manufactured by Denki Kagaku Kogyo) 5% by mass
Silica (Nippsil ss50 manufactured by Nippon Silica Industry) 7% by mass
Quartz (Pennsylvania Glass Sand Min-USil) 13% by mass
The above blend was defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 15 [Pa] and a TI value of 1.88.
A mixture A and a mixture B were obtained in the same manner as in Example 1.
Using this material, a φ12 mm elastic roll was formed in the same manner as in Example 1.
Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Comparative example 2>
Liquid silicone rubber material (Molecular weight Mw = 500,000) 60% by mass
Carbon black (Ketjen Black EC) 20% by mass
Silica (AEROSIL 380 manufactured by Nippon Aerosil) 20% by mass
The above blend was mixed and defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 810 [Pa] and a TI value of 7.21.
A mixture A and a mixture B were obtained in the same manner as in Example 1.
Using this material, an elastic roll having a diameter of 16 mm was formed in the same manner as in Example 5.

<Comparative Example 3>
Liquid silicone rubber material (molecular weight Mw = 100,000) 70% by mass
Carbon black (Denka black powder, manufactured by Denki Kagaku Kogyo) 5% by mass
Silica (Nippsil ss50 manufactured by Nippon Silica Industry) 7% by mass
Quartz (Pennsylvania Glass Sand Min-USil) 18% by mass
The above blend was mixed and defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 30 [Pa] and a TI value of 2.2.
A mixture A and a mixture B were obtained in the same manner as in Example 1.
Using this material, a φ12 mm elastic roll was formed in the same manner as in Example 1.
Further, in the same manner as in Example 1, a surface layer was formed to form a developing roll, which was incorporated into an image forming apparatus and subjected to image evaluation.

<Comparative example 4>
Liquid silicone rubber material (Molecular weight Mw = 100,000) 50% by weight Liquid silicone rubber material (Molecular weight Mw = 500,000) 30% by weight Carbon black (Denka black powder made by Denki Kagaku Kogyo) 6% by weight
Carbon black (Mitsubishi Chemical MA-11) 9% by mass
Silica (AEROSIL200 from Nippon Aerosil) 5% by mass
The above blend was defoamed for 30 minutes using a planetary mixer to obtain a silicone rubber base material having a yield stress of 500 [Pa] and a TI value of 6.9.
In the same manner as in Example 1, mixture A and mixture B were mixed at a ratio of 1: 1.
Using this material, an elastic roll having a diameter of 16 mm was formed in the same manner as in Example 5.

<Examples and evaluation results>
The outer diameter dimensions and coating thicknesses of the rolls of Examples 1 to 13 and Comparative Examples 1 and 2 were measured. The measurement positions are the outer diameter and coating thickness at two locations I and II (FIG. 4), 15 mm from the coating start position (position where the outer diameter is stable: FIG. 2) and 15 mm before the coating end position. The outer diameter difference was measured as a ratio to the coating thickness.
A: The ratio of the outer diameter difference to the coating thickness is 1% or less B: The ratio of the outer diameter difference to the coating thickness is 3% or less C: The ratio of the outer diameter difference to the coating thickness is larger than 3% Item D: The coated surface has streaks or irregularities The elastic rolls prepared in Examples 1, 2, 4 to 12 and Comparative Examples 1 and 3 are incorporated into the developing cartridge as a developing roll (φ12 roll is a color manufactured by HP) Laser Jet 3700, φ16 roll, Canon LASER SHOT LBP-2510), solid image was formed. With respect to the obtained solid image, the left and right image drawing directions (15 mm position from the left and right edges of the image) were each measured at five points using a Macbeth densitometer (RD918, Gretag Macbeth), and the average value was calculated. Next, a difference in average solid density (density difference between left and right) was calculated and judged based on the following levels.
A: The difference in solid density is smaller than 0.02 and good on the image B: The difference in solid density is 0.02 to 0.06 and does not cause any problem on the image C: The difference in solid density Those exceeding 0.06 When the fixing roll, pressure roll, and charging roll obtained in Examples 3, 13, and 14 were incorporated in an image forming apparatus and image evaluation was performed, a good image was obtained.

It is the schematic which shows the 1st apparatus with which the coating method of embodiment was applied. It is a figure which shows the ring coating head to which the coating method of embodiment was applied. It is a figure which shows the distance from the coating start of the elastic roll formed by the coating method of this invention until an outer diameter is stabilized. It is a figure which shows the position which measured the outer diameter dimension of the elastic roll shape | molded by the coating method of this invention. It is a figure which represents typically the 2 layer structure of the image development roll in this invention. 1 is a schematic view showing an image forming apparatus using a developing device of the present invention and a process cartridge of the present invention.

Explanation 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 axis
11.Supply port
12.Piping
13.Material supply valve
14.Linear guide
21 Photosensitive drum (image forming body)
22 charging roll
23 laser light
24 development equipment
25 developing roll
26 Developer supply roll
27 elastic blade
28 Developer (Toner)
29 Transfer roll
30 cleaning blade
31 Waste toner container
32 fixing roll
33 paper
34 Developer container
35 process cartridge
36 pressure roll
101 shaft core
102 elastic layer
103 Surface layer
201 Ring head top
202 Ring head bottom
203 Material inlet
204 Material flow path
205 Material outlet

Claims (12)

  In a method for producing an elastic roll obtained by coating a coating material containing a rubber material around a shaft core and vulcanizing and curing, the yield stress of the coating material is 50 Pa or more and 600 Pa or less, and the thixotropy index is 2 A method for producing an elastic roll, comprising coating a non-Newtonian liquid material having a thickness of 0.0 or more and 6.5 or less using a cylindrical coating head.   The method for producing an elastic roll according to claim 1, wherein the thickness of the covering to be molded is 0.5 mm or more and 6.0 mm or less.   The method for producing an elastic roll according to claim 1 or 2, wherein a thickness of the coating to be molded is more than 2.0 mm and 4.0 mm or less.   The method for producing an elastic roll according to any one of claims 1 to 3, wherein the coating material contains at least a conductive material.   The method for producing an elastic roll according to claim 4, wherein the conductive material in the coating material is in the form of a filler.   An elastic roll formed by the production method according to claim 1.   The elastic roll according to claim 6, wherein the elastic roll is any one of a fixing roll and a pressure roll of an electrophotographic apparatus.   A conductive roll formed by the production method according to claim 1.   The conductive roll according to claim 8, wherein the conductive roll is at least one of a developing roll and a charging roll of an electrophotographic apparatus.   An electrophotographic process cartridge that is equipped with a charging roll and that supplies electric charges to the surface of the photosensitive drum by bringing the charging roll into contact with the photosensitive drum, wherein the charging roll is the charging roll according to claim 9. An electrophotographic process cartridge. A developing roll is mounted, a thin layer of developer is formed on the surface of the developing roll, the developer roll is brought into contact with the image forming body, and the developer is supplied to the surface of the image forming body. In an electrophotographic process cartridge for forming a visible image on the surface of the formed body,
The electrophotographic process cartridge according to claim 9, wherein the developing roll is the developing roll according to claim 9. A developing roll is mounted, a thin layer of developer is formed on the surface of the developing roll, the developer roll is brought into contact with the image forming body, and the developer is supplied to the surface of the image forming body. In the image forming apparatus for forming a visible image on the surface of the formed body,
The image forming apparatus, wherein the developing roll is the developing roll according to claim 9.

Images