JP2008176029A - Resin core of elastic roller, electrophotograph process cartridge, and electrophotographic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a strong resin core which is for an elastic roller used in electrophotographic equipment, without the use of metals and without loading the environments with its wastes, when machining and is capable of reducing the core weight, and also provide an elastic roller using this core, an electrophotograph process cartridge and electrophotographic equipment by using this elastic roller for developing. <P>SOLUTION: This resin core unitizes a core shaft and a drive means, formed to transmit the torque to its end and is made of a resin composition, containing both porous particles and a filler of fibers having length of 100% or higher and 180% or lower of the particle diameter. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an elastic roller core for an electrophotographic apparatus, and more particularly to a resin core for an elastic roller. The present invention also relates to an elastic roller using the resin core for the elastic roller as a core, an electrophotographic process cartridge and an electrophotographic apparatus incorporating the elastic roller as a developing roller.

  Conventionally, various elastic rollers used in electrophotographic apparatuses such as copying machines and laser beam printers are made by laminating an elastic layer or a resin layer on the outer periphery of a metal core such as iron or aluminum. The characteristics suitable for

  This metal core is usually formed by cutting a raw metal round bar. Further, since the core of the elastic roller used in the electrophotographic apparatus is combined with a member such as a gear for driving, the end portion is generally complicated in shape in many cases. Therefore, as a cost required for the core metal, not only the material cost but also the processing cost occupies a large proportion. Therefore, the cored bar is expensive. Further, the more complicated the end shape is, the more cutting scraps, that is, wastes that are scraped from the round bar during processing, which is an insufficient method from the viewpoint of reducing the burden on the environment.

  For such problems, the conductive resin shaft (from the merit that the material cost is low, the processing property can be easily reduced due to its physical properties, and the weight can be reduced compared to the metal cored bar ( In some cases, a technique using a cored bar is used (Patent Document 1). In addition, a conductive roller is disclosed in which a thin polyurethane layer or a silicone rubber layer is formed by RIM or LIM molding on a roller body made of resin which serves as a core metal and a roller body (Patent Document 2).

  When the cored bar shape is formed of resin in this way and used as an elastic roller cored bar of an electrophotographic apparatus, the elastic roller to which the cored bar is mounted is rotated by another power. At this time, in order to transmit the rotation, a driving member (hereinafter sometimes referred to as “gear”) is usually attached or integrally formed at the end of the cored bar. Since the rotational force from the gear is transmitted to the elastic roller main body, stress concentrates on the core metal portion where the gear is mounted or integrally formed, and the resin core metal has insufficient durability.

  In order to improve the strength of the resin core bar against such a problem, a method of blending various fillers in the resin to be used has also been proposed (Patent Document 3).

However, the filler, which can be blended in the resin and can sufficiently improve the mechanical strength of the resin, has a limited composition, shape, etc., and is expensive compared to other general-purpose fillers. I have to be. Therefore, in order to obtain sufficient strength, it is insufficient for the low cost, which is one of the objects of the present technology. Furthermore, if the particle shape of the filler is complicated, the filler particle shape may be destroyed by the stress when the resin cored bar is created by injection molding, and as a result, the strength required for the molded product may not be obtained. Yes, it is insufficient as a resin for metal replacement.
JP 2004-150610 A JP 2004-151616 A JP 2003-195601 A

  An object of the present invention is not only to reduce the environmental load caused by the waste material cut by cutting as an elastic roller cored bar of an electrophotographic apparatus, but also to reduce the weight of the cored bar and to be sufficient as a cored bar. An object of the present invention is to provide a resin core bar for an elastic roller having strength at low cost. Another object of the present invention is to provide an elastic roller using the resin cored bar, an electrophotographic process cartridge and an electrophotographic apparatus using the elastic roller as a developing roller.

  In order to achieve the above-mentioned problems, the present inventors have intensively studied, and even if a driving member is integrally formed in a resin cored bar, a fibrous filler having a specific fiber length and porous particles are mixed into the resin. It has been found that a core bar having sufficient strength can be obtained, and finally the present invention has been achieved.

  That is, the present invention is a resin cored bar for an elastic roller of an electrophotographic apparatus, in which a driving member is integrally formed on at least one end of a shaft core part, and the porous particles and the average of the porous particles A resin cored bar for an elastic roller, characterized in that it is formed of a resin composition containing a fibrous filler having a fiber length of 100% to 180% of the particle size.

  Further, the present invention provides a driving composition at least at one end of the shaft core portion by a resin composition containing porous particles and a fibrous filler having a fiber length of 100% to 180% of the average particle diameter of the porous particles. The elastic roller is characterized in that an end portion of an elastic layer provided on the outer periphery of a resin cored bar for an elastic roller integrally formed with the member is integrated with a driving member.

  Furthermore, the present invention provides an electrophotographic process cartridge in which an electrostatic latent image formed on a photosensitive drum is visualized by a developer carried on a developing roller, the developing roller being the elastic roller This is an electrophotographic process cartridge.

  Furthermore, the present invention is an electrophotographic apparatus in which an electrostatic latent image formed on a photosensitive drum is visualized by a developer carried on a developing roller, wherein the developing roller has the above-described elasticity. The electrophotographic apparatus is a roller.

  According to the present invention, there is provided a resin-made metal core having a small environmental load and having a sufficient strength and reduced in weight as compared with a metal metal core with a reduced amount of material generated by cutting. Provided. Further, a developing roller having good performance using the cored bar is provided.

  First, an elastic roller using the resin cored bar of the present invention will be described.

  A sectional view of an example of the elastic roller is shown in FIG.

  A cylindrical elastic layer 2 is formed on the outer peripheral surface of a resin rod-shaped cored bar 1. The end of the elastic layer 2 is integrated with a driving member 4 formed integrally with the cored bar 1. On the other hand, a resin layer 3 having a necessary function is formed on the outer periphery of the elastic layer 2 according to the purpose of use of the elastic roller.

  The resin cored bar 1 is not particularly limited as long as sufficient strength is achieved as a resin material, but is preferably selected from thermoplastic resins in consideration of recycling.

  In the present invention, the resin cored bar 1 is provided with both porous particles and a fibrous filler having a fiber length of 100% to 180% of the average particle diameter of the porous particles. It is necessary to achieve the strength of gold, particularly the strength of the portion integrated with the driving member.

  The porous particles can be appropriately selected from calcium carbonate, aluminum hydroxide, aluminum silicate, magnesium silicate and the like as long as the average particle size is 100 μm or less. When the average particle diameter exceeds 100 μm, the reinforcing effect expected when used in combination with the fibrous filler cannot be exhibited, which is not preferable. It is appropriate that the amount of the porous particles is 5 parts by mass or more and 50 parts by mass with respect to 100 parts by mass of the raw material resin because sufficient strength is obtained as a cored bar. In addition, as a porous particle, in order to acquire the reinforcement effect by combined use with a fibrous filler, it is desirable that an average particle diameter is 0.5 micrometer or more.

  The surface properties of the porous particles are preferably porous from the viewpoint of developing a synergistic effect with the fibrous filler added at the same time. In other words, the porous particles come into contact with the fibrous filler at the concavo-convex portion of the surface, and the movement of the fibrous filler is restricted compared to the particles without the concavo-convex, and the reinforcing effect is made like particles having an apparently large particle diameter. To express. Actually, when the fibrous filler and the spherical filler having no irregularities on the surface were used, the reinforcing effect more than when each was blended alone was not expressed.

  As the fibrous filler, a fibrous filler having a fiber length of 100% or more and 180% or less of the average particle diameter of the porous particles used in combination is appropriately selected and used. Specifically, as long as the fiber length is 1 μm or more and 200 μm or less, it can be appropriately selected from carbon fiber powder, glass fiber powder, cellulose fine powder, silk fine powder, and various whiskers. The aspect ratio of the fibrous filler is preferably about 10 or more and 100 or less from the viewpoint of reinforcing the strength of the cored bar and improving the dispersibility in the resin during production.

  When the fiber length of the fibrous filler is out of this range, when the resin cored bar is formed, the surface roughness of the cored bar becomes too large, and when used as a conductive roller or the like, This is not preferable because the wear of the member is promoted.

  The blending amount of the fibrous filler is suitably 5 to 50 parts by mass with respect to 100 parts by mass of the raw resin. When the blending amount is within this range, sufficient strength as a core metal can be obtained.

  In addition, when using the fibrous conductive agent which has electroconductivity, such as a metal fiber and carbon fiber, as a following conductive agent, the thing of the range of fiber length 1 micrometer to 100 micrometers is 50 mass% or more, Preferably it contains 80 mass% or more In such a case, the fibrous filler can also be used.

In addition, when the elastic roller is a conductive elastic roller, the cored bar needs to be conductive. Therefore, even when the resin material itself has conductivity, metal powders and fibers such as aluminum, palladium, iron, copper and silver; metal oxides such as titanium oxide, tin oxide and zinc oxide; copper sulfide Metal compound powders such as zinc sulfide; tin oxide, antimony oxide, indium oxide, molybdenum oxide, zinc, aluminum, gold, silver, copper, chromium, cobalt, iron, lead, platinum, rhodium, etc. on the surface of suitable particles Powder deposited by electrolytic treatment, spray coating, mixed shaking, etc .; carbon powders such as acetylene black, ketjen black (trade name), PAN-based carbon black, pitch-based carbon black; KSCN, LiClO ₄ , NaClO _4. It is preferable to arrange a conductive agent such as an ion conductive material such as a quaternary ammonium salt.

  In the present invention, fumed silica, wet silica, quartz fine powder, diatomaceous earth, carbon black, zinc oxide, basic magnesium carbonate, activated calcium carbonate, silica, and the like are further added to provide sufficient bending strength and heat resistance. Fillers such as magnesium oxide, aluminum silicate, titanium dioxide, talc, mica powder, aluminum sulfate, calcium sulfate, barium sulfate, glass powder, organic reinforcing agent, and organic filler may be arranged.

  In the resin cored bar of the present invention, the diameter of the axial center part forming the elastic layer is 2 mm or more, preferably 4 mm or more in order to obtain sufficient strength. In addition, if the elastic layer can be formed with a necessary thickness as an elastic roller, it is preferably as large as possible. However, it is appropriate to set it to 15 mm or less, preferably 12 mm or less in view of handling.

  Further, as the shape of the core bar integrally provided with the driving member of the present invention, if the shaft center portion has sufficient strength, the portion of the driving member can sufficiently transmit power to the elastic roller. If it is, it will not specifically limit. For example, a gear shape, a D-cut shape, a rectangular shape, an elliptical shape, and the like can be shown, and may be determined according to the purpose of use.

  For example, in the case where the portion with the driving member is a gear shape or a rectangular convex shape, (a) a front view and (b) a side view seen from the arrow side shown in the front view are shown in FIGS. , Respectively. In FIGS. 3 and 4, reference numeral 1 denotes a resin core, and a driving member 4 is integrated at one end thereof.

  For example, when polystyrene is used as the resin material, the resin metal core can be manufactured as follows.

  A cylindrical mold having a cavity for forming a driving member at one end is set in an injection molding apparatus, and the mold is heated to a temperature of 60 ° C to 100 ° C. In this state, a molten resin material is injected into the cavity in the range of 150 ° C. to 200 ° C. Thereafter, the mold is cooled to room temperature, for example, and the injection molded body is taken out from the mold. Next, the resin cored bar is obtained by taking a strain in a temperature-controlled room adjusted to 60 ° C. to 80 ° C. for about one week. In addition, these temperature, time, etc. can be suitably changed with the shape of a metal core, a magnitude | size, a resin composition, etc.

  The material for the elastic layer can be appropriately selected from those used for known elastic rollers. Moreover, the hardness can also be suitably determined according to the purpose of use. In the case of a conductive elastic roller, the elastic layer has conductivity, but the degree of conductivity can be appropriately determined according to the purpose of use.

  In the case of a conductive elastic roller used in an electrophotographic process, a liquid rubber material, preferably a liquid addition reaction cross-linked silicone rubber, blended with a conductive filler such as carbon black as a conductivity imparting agent as a material of the elastic layer Is preferably used.

  As a material for the elastic layer, it is excellent in processability, has no dimensional stability due to the absence of by-products associated with the curing reaction, and has a liquid addition reaction for reasons such as stable physical properties after curing. Cross-linked silicone rubber is preferred.

  This addition reaction crosslinking type silicone rubber contains, for example, an organopolysiloxane represented by the formula (1) and an organohydrogenpolysiloxane represented by the formula (2), and further, a catalyst and other additives, Are appropriately mixed and used.

  In addition, the composition obtained by mix | blending a catalyst and an additive with the organopolysiloxane represented by Formula (1) and the organohydrogenpolysiloxane represented by Formula (2) is called a liquid silicone rubber material.

  The organopolysiloxane represented by the formula (1) is a base polymer of a liquid silicone rubber raw material, and the molecular weight thereof is not particularly limited, but the weight average molecular weight is 100,000 to 1,000,000, preferably 400,000 to 700,000. Is appropriate. Furthermore, from the viewpoint of processing characteristics and characteristics of the resulting silicone rubber composition, the organopolysiloxane has a viscosity (25 ° C.) of 10 Pa · s to 300 Pa · s, preferably 50 Pa · s to 250 Pa · s. Is preferred.

  The alkenyl group in the organopolysiloxane is a site that reacts with the active hydrogen of the organohydrogenpolysiloxane to form a crosslinking point, and the kind thereof is not particularly limited. However, for reasons such as high reactivity with active hydrogen, a vinyl group or an allyl group is preferable, and a vinyl group is particularly preferable.

  The organohydrogenpolysiloxane represented by the formula (2) functions as a crosslinking agent for addition reaction in the curing step. Accordingly, the number of silicon atom-bonded hydrogen atoms in one molecule is 2 or more, and from the viewpoint of excellent curing reaction, the number of silicon atom-bonded hydrogen atoms in one molecule is preferably 3 or more. .

  The molecular weight of the polyorganohydrogenpolysiloxane is not particularly limited, and for example, a molecular weight of 1000 to 10,000 can be used. However, in order to appropriately perform the curing reaction, it is preferable to use one having a relatively low molecular weight (for example, a weight average molecular weight of 1000 or more and 5000 or less).

As a catalyst for the crosslinking reaction between the organopolysiloxane and the organohydrogenpolysiloxane, for example, chloroplatinic acid hexahydrate can be used, and a transition metal compound that exhibits a catalytic action in the hydrosilylation reaction can also be used. is there. Specific examples _{thereof, Fe (CO) 5, Co} (CO) 8, RuCl 3, IrCl 3, [(olefin) PtCl _{2] 2,} a vinyl group-containing polysiloxane -Pt complex, L ₂ Ni (olefin), L ₄ Pd, L ₄ Pt, L ₂ NiCl ₂ (wherein L is PPh ₃ or PR ₃ , where P is phosphorus, Ph is a phenyl group, and R is an alkyl group). Among these, platinum, palladium or rhodium-based transition metal compound catalysts are preferable.

  In the case of a platinum-based metal compound catalyst, the amount of the catalyst used is preferably 1 to 100 ppm by mass as platinum in the liquid silicone rubber material, but is not limited to this range, and the target pot life and curing time are as follows. It is appropriately selected depending on the product shape and the like.

  In addition, the liquid silicone rubber material can contain an unsaturated alcohol such as 1-ethynyl-1-cyclohexanol or phenylbutynol as a curing reaction retarder. The blending amount of the curing reaction retarder is appropriately determined depending on the target pot life, curing time, product shape, etc. in the range of 0.05 to 0.5 parts by mass with respect to 100 parts by mass of the organopolysiloxane. Is done.

  The viscosity ρ (25 ° C.) of the liquid silicone rubber material in which necessary fillers are blended is not particularly limited, but is appropriately determined according to the elastic layer forming method. For example, when using a metal mold in which a core metal is housed in a cavity, the pressure is preferably 10 Pa · s or more from the viewpoint of suppressing the fluidity of the material to some extent and preventing the material leakage from the metal mold. From the viewpoint of avoiding the problem of molding processability such as generation of welds between the injection gates, 300 Pa · s or less is preferable.

  In the present invention, in order to form an elastic layer around the core metal, the elastic layer material is extruded into a tube shape, heated and cured, then cut, and the core metal coated with an adhesive is pushed into the core metal or the core metal is formed into a cavity. A method in which the liquid elastic layer material is poured into the mold and heated and cured is suitable.

  When the liquid silicone rubber material is used as the elastic layer material, the following method is preferred.

  An elastic layer formed between the metal mold and the core metal is placed in a cylindrical metal mold that has a cavity with an outer shape of an elastic roller. Liquid silicone rubber material is injected into the cavity. In the mold, the liquid silicone rubber is primarily heated and vulcanized at a temperature of 100 ° C. to 150 ° C. for 0.1 hour to 1 hour, and the molded product is taken out from the mold. If necessary, the molded product can be further heated and vulcanized in a thermostat whose temperature is adjusted from 180 ° C. to 220 ° C. to form an elastic layer on the cored bar.

  When the elastic roller used in the electrophotographic process is a conductive elastic roller, the thickness of the conductive elastic layer is usually in the range of 2 mm to 6 mm, preferably in the range of 3 mm to 5 mm, although it varies depending on the purpose of use. To do.

  The elastic roller manufactured as described above can be used as it is as various rollers used in an electrophotographic process as it is, but the surface layer is formed after polishing with a blast or a grindstone if necessary, It is an elastic roller according to the purpose.

  As the resin material for forming the surface layer, for example, various polyamide resins, fluorine resins, hydrogenated styrene-butylene resins, urethane resins, silicone resins, polyester resins, phenol resins, imide resins, olefin resins, and the like can be used.

  These materials are prepared in a suitable solvent, for example, methyl ethyl ketone, toluene, methyl isobutyl ketone, etc. together with necessary additives using a conventionally known dispersion apparatus using beads such as a sand mill, paint shaker, dyno mill, pearl mill, etc. Used in a dispersed manner. By performing this dispersion, a coating solution for obtaining a surface layer with few surface defects can be obtained. It is desirable to select a solvent that does not attack the resin cored bar.

  The obtained coating liquid for forming the surface layer can be applied onto the elastic layer by a roller coating method, a spray coating method, a dipping method, a ring coating method, a brush coating or the like.

  When the resin cored bar is poor in resistance to the solvent used in the coating solution during coating, there is a concern that if the part exposed from the elastic layer touches the solvent, problems such as strength and dimensional accuracy may occur. is there. Therefore, it is preferable to take protective means such as a masking cap and a masking agent coat so that the solvent does not touch the exposed portion. This measure is particularly important in the case of coating by the dipping method. It is also effective to devise a coating method so that the solvent does not touch the exposed portion.

  In the case of an elastic roller used in an electrophotographic process, the thickness of the surface layer is preferably 5 μm or more from the viewpoint of preventing low molecular weight components from seeping out from the elastic layer and contaminating the photosensitive drum. Further, it is preferably 500 μm or less from the viewpoint of preventing the surface of the elastic roller from becoming hard and preventing toner fusion. More preferably, it is in the range of 10 μm to 30 μm.

  In the case where the elastic roller is a developing roller, if fine particles having an average particle size in the range of 1 μm to 20 μm are dispersed in the surface layer, the developer conveyance on the surface of the developing roller is improved, and a sufficient amount of developer is supplied to the developing region. It is preferable because it can be conveyed to the surface. Examples of the fine particles used for this 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. Particularly preferred are polymethyl methyl methacrylate fine particles and polyurethane fine particles. These fine particles are preferably added in a range of 3% by mass to 200% by mass with respect to the total mass of the surface layer constituent components excluding the fine particles.

  Next, FIG. 2 schematically shows an example of a contact developing type electrophotographic apparatus using an electrophotographic process cartridge in which the elastic roller of the present invention is incorporated as a developing roller.

  A photosensitive drum 31, a primary charging roller 32, a developing roller 33, a developer supply roller 34, a toner layer thickness regulating member (developing blade) 35 that is a developer layer thickness regulating member, a stirring blade 36, and a toner 37 that is a developer. The cartridges are integrated into one and can be replaced as a unit.

  The photosensitive drum 31 that is uniformly charged by the primary charging roller 32 rotates in the direction of the arrow, and a laser beam 40 carrying recording information on the surface is irradiated between the primary charging roller 32 and the developing roller 33. An electrostatic latent image is formed. On the other hand, the toner 37 sent to the developer supply roller 34 by the stirring blade 36 is uniformly coated on the surface of the developing roller 33 by the toner layer thickness regulating member 35, is carried to the surface of the photosensitive drum 31, and the photosensitive drum 31. The electrostatic latent image formed on the surface is visualized as a toner image. When the photosensitive drum 31 further rotates and the toner image reaches the transfer region, the toner image is transferred onto a recording medium 43 such as paper by a transfer roller 42 that is opposed to the photosensitive drum 31. The photosensitive drum 31 is uniformly charged again by the primary charging roller 32 after the toner remaining without being transferred to the recording medium 43 by the cleaning elastic member 38 is removed from the surface thereof.

  The unfixed toner image transferred to the recording medium 43 passes between the fixing roller 44 and the pressure roller 45, is fixed to the recording medium by pressure and heat, and is discharged from the electrophotographic apparatus.

  On the other hand, the developing roller 33 is returned to the developing container 41 while the toner remaining without being used for development is carried on the surface. Inside the developing container 41, the developer supply roller 34 removes the toner remaining on the surface of the developing roller 33 and supplies new toner to the surface of the developer carrying roller 33. The new toner supplied to the surface of the developing roller 33 has its layer thickness made uniform again by the toner layer thickness regulating member 35 and is conveyed to the developing region. By repeating this, the developing roller 33 is always uniformly coated with new toner, and the electrostatic latent image is developed.

  Hereinafter, the present invention will be described in more detail with reference to examples. This does not limit the invention in any way.

  First, image development evaluation of the developing roller performed in the following examples and comparative examples will be described.

Image evaluation:
The developing roller produced in the following examples and comparative examples is incorporated as a developing roller in a cartridge of an electrophotographic laser beam printer “LBP-2510” (trade name) manufactured by Canon Inc., and a solid image and a halftone image are output. did. The obtained image was visually observed and evaluated according to the following criteria. “LBP-2510” used for the evaluation is an A4 version output machine, output speed: A4 vertical 16 sheets / minute, and image resolution: 600 dpi. The photosensitive drum is of a reversal development type in which an OPC (organic photoconductor) layer is coated on an aluminum cylinder, and the outermost layer is a charge transport layer using a modified polycarbonate as a binder resin.
○: Density unevenness is hardly seen in any image.
Δ: Although slight density unevenness is observed in the halftone image, there is no practical problem.
X: Density unevenness due to circumferential abnormality of the developing roller is observed, which is a problem in practical use.

[Example 1]
Glass fiber “EFH75-01” (milled fiber, manufactured by Central Glass Co., Ltd., aspect ratio: 12) with 100 parts by mass of polystyrene resin pellets “Topolex G120K” (trade name, manufactured by Nippon Polystyrene Co., Ltd.) .5) 20 parts by mass and 20 parts by mass of silicic acid (fine sand C, Nippon Silica Kogyo Co., Ltd.) having an average particle size of 75 μm as porous particles and 3 parts by mass of acetylene black were blended to obtain a raw material resin composition. . As shown in FIG. 3, this raw material resin composition was injection-molded into a cored bar manufacturing pipe mold at a resin temperature of 200 ° C. and a mold temperature of 80 ° C., and a gear having an outer diameter of 12 mm and a diameter of 8 mm was attached. A resin cored bar was obtained. The gear thickness was 2 mm. The fiber length of the fibrous filler was 100% of the average particle diameter of the porous particles.

  A silicone primer was applied to the resin core, and then set in a developing roller forming die. A liquid addition reaction type silicone rubber having a viscosity of 150 Pa · s in a liquid state and an Asuka C hardness of 40 ° after curing was injected into the cavity of the mold. The liquid addition-reaction type silicone rubber is an appropriate blend of organopolysiloxane, organohydropolyenepolysiloxane, conductive carbon black, platinum catalyst, quartz, and silica. Next, it was heat-cured, and an elastic layer of silicone rubber having a length of 230 mm and a thickness of 2 mm was formed on the outer periphery so as to be in close contact with the gear. The heat curing conditions for the silicone rubber layer were 100 ° C. × 30 minutes.

  Subsequently, 10 parts by mass of polymethyl methacrylate fine powder (average particle size: 10 μm), 5 parts by mass of ketjen black and 30 parts by mass of polyester resin were blended, and the coating composition for the surface layer was made 10% by mass with methyl ethyl ketone (MEK). Was made. The roller on which the silicone rubber elastic layer obtained above is formed on this paint is masked on the exposed part of the core (on the opposite side to the side where the gear is formed), then dipped, dried and cured after the solvent is dried. Thus, a surface layer having a thickness of 20 μm was formed to obtain a developing roller.

  Image evaluation was performed using the obtained developing roller. The result was “◯”.

[Example 2]
A developing roller was prepared in the same manner as in Example 1 except that glass fiber “EFH100-31” (milled fiber, manufactured by Central Glass Co., Ltd.) having an average fiber length of 122 μm was used as the glass fiber. The result of image evaluation using the obtained developing roller was “◯”. The fiber length of the fibrous filler was 163% of the average particle diameter of the porous particles.

[Comparative Example 1]
A developing roller was prepared in the same manner as in Example 1 except that glass fiber “EFH50-31” (milled fiber, manufactured by Central Glass Co., Ltd.) having an average fiber length of 50 μm was used as the glass fiber. The result of image evaluation using the obtained developing roller was “×”. The fiber length of the fibrous filler was 67% of the average particle diameter of the porous particles.

[Comparative Example 2]
A developing roller was prepared in the same manner as in Example 1 except that glass fiber “EFH150-31” (milled fiber, manufactured by Central Glass Co., Ltd.) having an average fiber of 146 μm was used as the glass fiber. The result of image evaluation using the obtained developing roller was “×”. The fiber length of the fibrous filler was 197% of the average particle diameter of the porous particles.

It is sectional drawing of an example of the elastic roller of this invention. 1 is a conceptual diagram of an example of an electrophotographic apparatus of the present invention. It is the (a) front view and (b) side view from an arrow direction of an example of the resin-made metal cores of this invention. It is (a) front view and (b) side view from the arrow direction of another example of the resin cored bar of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin metal core 2 Elastic layer 3 Surface layer 4 Driving member 31 Photosensitive drum 32 Primary charging roller 33 Developing roller 34 Developer supply roller 35 Toner layer thickness regulating member (developing blade)
36 Stirring blade 37 Toner 38 Elastic member for cleaning 40 Laser beam 41 Developer container 42 Transfer roller 43 Recording medium 44 Fixing roller 45 Pressure roller

Claims (4)

A resin core for an elastic roller of an electrophotographic apparatus,
A drive member is integrally formed on at least one end of the shaft core,
And a resin composition for an elastic roller, characterized in that it is formed of a resin composition containing porous particles and a fibrous filler having a fiber length of 100% to 180% of the average particle diameter of the porous particles. Core metal.   A driving member is integrally molded at least at one end of the shaft core portion with a resin composition containing porous particles and a fibrous filler having a fiber length of 100% to 180% of the average particle diameter of the porous particles. An elastic roller characterized in that an end portion of an elastic layer provided on an outer periphery of a resin core metal for an elastic roller is integrated with a driving member.   An electrophotographic process cartridge in which an electrostatic latent image formed on a photosensitive drum is visualized by a developer carried on a developing roller, wherein the developing roller is for an elastic roller according to claim 2. An electrophotographic process cartridge, which is an elastic roller made of a resin cored bar.   An electrophotographic apparatus in which an electrostatic latent image formed on a photosensitive drum is visualized by a developer carried on a developing roller, wherein the developing roller is an elastic roller according to claim 2. An electrophotographic apparatus characterized by that.

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