JP5094078B2 - Method for producing elastic roller - Google Patents

Description

The present invention is a printer, the present invention relates to resilient low la fabrication method used like in an image forming apparatus and electrophotographic process cartridge such as a copying machine.

  A conventional electrophotographic apparatus will be described below. An image forming unit is installed inside the main body of the apparatus, and an image is formed through processes of cleaning, charging, latent image, development, transfer, and fixing. The image forming unit includes a photosensitive drum as an image carrier, and includes a cleaning unit, a charging unit, a latent image forming unit, a developing unit, and a transfer unit. The image on the photosensitive drum formed by the image forming unit is transferred to a recording material (transfer material) by a transfer member, conveyed, and then heated and pressed in a fixing unit, and output as a fixed recorded image. Is done.

  Next, among the cleaning, charging, latent image, development, transfer, and fixing processes, the charging, latent image formation, development, and transfer processes will be described.

  The charging member performs a primary charging process on the surface of the photosensitive drum so that the potential is uniform with a predetermined polarity. After being uniformly charged by the charging member, the target image information is exposed to form an electrostatic latent image corresponding to the target image on the surface of the photosensitive drum. This electrostatic latent image is visualized as a developer image by a developing device. The visualized developer image is transferred to the recording material by applying a voltage from the back surface of the recording material by the transfer means under the photosensitive drum. Thereafter, the recording material is conveyed to a fixing unit, subjected to image fixing, and output as an image formed product.

  In the developing device in the image forming apparatus such as the electrophotographic apparatus described above, since it is good to contact the photosensitive drum, a charging member, a developing member for visualizing a latent image, a rubber material or the like for a transfer unit, etc. An elastic roller having the elastic body is used.

  Very high dimensional accuracy is required for the shape of the elastic roller used in these image forming apparatuses. If these dimensional accuracy is poor, for example, in the developing member, the amount of the developer supplied to the photosensitive drum becomes non-uniform, which may cause adverse effects such as density unevenness and resistance unevenness. Further, in the charging member, the photosensitive drum cannot be uniformly charged, and as a result, there is a possibility that the image is adversely affected.

  In order to meet this demand for high dimensional accuracy, various molding methods such as molding using a mold and molding by extrusion have been studied as methods for producing various elastic rollers. In addition, various methods such as spray coating, dip coating, roll coating, blade coating, etc. have been studied as methods for directly applying a liquid material to the shaft core. When applied to a roller or the like that requires several millimeters, there are various problems.

  For example, in spray coating, if the viscosity of the paint is high, it is difficult to atomize uniformly, so it is necessary to keep the viscosity of the paint low. 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 part may appear directly in the image.

  Under such circumstances, a coating method using a cylindrical coating head is disclosed as a method for directly coating a high-viscosity material (see Patent Document 1). This document discloses a method of coating a coating liquid on the surface of the cylindrical body in a state where the center line of the cylindrical body is parallel to the horizontal direction. According to this document. By using this method, the restriction of the coating process due to the viscosity of the coating liquid and the film thickness of the coating film is removed, and the coating liquid is directly applied to the surface of the cylindrical body with a simpler apparatus, so that a good and uniform coating is achieved. It is said that a coating method capable of forming a film is provided.

  By using the above technique, a highly viscous material can be applied directly to the shaft core. However, in the coating method using the cylindrical coating head, the elastic layer material spreads in the circumferential direction due to the weight of the upper end portion of the elastic layer material with the lapse of time at the start of coating of the material to be coated (roller end portion). May cause honey. When an elastic roller with an end portion is used, the contact state with the mating member is biased, and local stress concentration occurs at the end of the elastic roller, resulting in a large stress on the elastic roller or the mating member. This may cause accelerated wear and deterioration of the part. In addition, the balance of charge and developer supply may be disrupted, which may cause uneven resistance and image defects, particularly density unevenness. In order to avoid this problem, there is a means for cutting off the end of the elastic roller, but this increases the waste material.

As a method for solving the above problem, a method using a masking member is disclosed (see Patent Document 2). This is because the masking cap is attached to at least one of the shaft cores, thereby preventing the material from adhering to the shaft cores and preventing the bulges of the material from being formed at both ends of the elastic layer material. Is the method. However, this technique relates to a case where conductive paint is dip-coated on an elastic roller that has been previously coated with an elastic layer material, and a process of coating the elastic layer material on the shaft core and a cylindrical coating head are used. No mention is made of the application method.
JP 2003-190870 A JP 2001-179144 A

  As described above, when an elastic roller having an end portion is used, the contact state with the counterpart member is biased, and local stress concentration occurs at the end portion of the elastic roller. Wear and deterioration may be accelerated. In addition, the balance of charge and developer supply may be disrupted, which may cause uneven resistance and image defects, particularly density unevenness.

  Up to now, when adjusting the end shape during the production of an elastic roller, the elastic layer material is controlled to have a high viscosity to prevent dripping at the end of the elastic layer material after coating. The end shape accuracy has been improved by adjusting the coating speed of the elastic layer material on the body. However, the adjustment of the material viscosity and the adjustment of the coating speed cannot take a complete correlation with the end shape accuracy after coating, and it cannot be said that it is easy to manufacture a roller having a highly accurate end shape.

An object of the present invention is to use a coating head having an annular slit opened inward to move the coating head in the direction of gravity relative to the shaft core body, so that the annular slit is not formed on the outer peripheral surface of the shaft core body. In the manufacturing method of an elastic roller that cures an uncured elastic material after discharging the cured elastic layer material, the amount of waste at the upper end of the elastic roller at the end of coating can be reduced, and waste materials can be reduced. made, high dimensional accuracy, is to provide a method for producing low-cost elastic low la.

  As a result of intensive studies to solve this problem, the present inventors attached a ring-shaped member to the shaft core at the start of coating, and contacted the end of the elastic layer material to be covered with the ring-shaped member. Then, it has been found that a roller having extremely excellent edge shape accuracy can be produced by a process of curing an uncured elastic layer material and forming an elastic layer with the ring-shaped member attached.

According to the present invention, an uncured elastic layer material is discharged from the annular slit onto the outer peripheral surface of the shaft core body while moving the coating head having the annular slit opened inward in the direction of gravity relative to the shaft core body. Elastically applied to the outer peripheral surface of the shaft core body, and having a coating step of curing the uncured elastic material coated on the outer peripheral surface of the shaft core body after the coating step. In a method for producing an elastic roller having a layer,
Before the coating step, it has a ring-shaped member arrangement step of arranging a ring-shaped member,
In the ring-shaped member arrangement step, the maximum outer diameter portion of the ring-shaped member is positioned rearward in the coating head moving direction from the end on the coating head moving direction rear side of the opening of the annular slit,
In the coating step, the coating head discharges and coats an uncured elastic layer material on the outer peripheral surface of the shaft core so as to contact the ring-shaped member,
In the curing step, the uncured elastic layer material is cured without removing the ring-shaped member to form an elastic layer,
And the manufacturing method of the elastic roller whose viscosity in 25 degreeC of this uncured elastic layer material is 10 Pa.s or more and 5000 Pa.s or less is provided.

According to the present invention, using a coating head having an annular slit opened inward, the coating head is moved in the direction of gravity relative to the shaft core body, and the annular slit is not formed on the outer peripheral surface of the shaft core body. In the manufacturing method of an elastic roller that cures an uncured elastic material after discharging the cured elastic layer material, the amount of waste at the upper end of the elastic roller at the end of coating can be reduced, and waste materials can be reduced. made, high dimensional accuracy, a manufacturing method of low-cost elastic row La is provided.

  Hereinafter, although the form of this invention is demonstrated, this invention is not limited by this.

  A series of basic flows for manufacturing the elastic roller in the present invention is as follows. That is, by using a coating head having an annular slit opened inside, the coating head is moved in the direction of gravity relative to the shaft core body, and the uncured elastic layer material from the annular slit on the outer periphery of the shaft core body After the discharge coating, the uncured elastic material is cured. In this method, a ring-shaped member is mounted behind the annular slit of the coating head in the traveling direction (coating head moving direction) before coating. Thereafter, an uncured elastic layer material is discharged and coated on the outer periphery of the shaft core body by the coating head. Then, the uncured elastic layer material is cured while the ring-shaped member is mounted to form an elastic layer. At this time, an elastic roller in which the amount of splash at the end portion is suppressed can be obtained by performing a curing step such as heat treatment while the upper end of the uncured elastic layer material is in contact with the ring-shaped member.

  FIG. 1 is a schematic cross-sectional view of an example of a coating head that can be suitably used in the present invention. As shown in FIG. 1, the coating head 308 is configured such that the first annular member 101 and the second annular member 102 are held by an annular member holding member 105 having a supply port 311. The coating head 308 having the first annular member 101 and the second annular member 102 has an annular slit 103 that opens to the inside. The annular slit 103 is controlled by the first annular member 101 and the second annular member 102. That is, the 1st annular member 101 and the 2nd annular member 102 comprise the surface (A surface and B surface in FIG. 1) of an annular slit. The first annular member 101 has an annular slit A surface, and the second annular member 102 has an annular slit B surface. The cylindrical surface forming the smallest diameter portion inside the first annular member and the cylindrical surface forming the smallest diameter portion inside the second annular member have a diameter (this diameter is the inner diameter L of the coating head) and a central axis. Are the same, and the elastic layer material discharge port 104 exists between both cylindrical surfaces.

  The first annular member 101 has a throttle step 107, and a liquid distribution chamber 106 is formed with the annular member holding member 105. Therefore, the annular slit 103 is connected to the liquid distribution chamber 106 through which the elastic layer material passes, and is further connected to the supply port 311 for supplying the elastic layer material to the lower side of the liquid distribution chamber 106. The liquid distribution chamber 106 is provided with a throttle step 107 through which the elastic layer material passes. The elastic layer material is uniformly distributed in the annular slit 103 on the elastic layer material discharge port 104 side by once narrowing the flow path of the elastic layer material supplied from the supply port 311 and increasing the internal pressure of the liquid distribution chamber 106 on the supply port 311 side. Inflow. Thereby, the elastic layer material is uniformly discharged from the elastic layer material discharge port 104.

  The coating head 308 is composed of three members: a first annular member 101, a second annular member 102, and an annular member holding member 105. However, the coating head 308 may be an integral mold or may be composed of two or more members. The inner diameter L of the coating head 308 and the width of the annular slit 103 are appropriately selected depending on the film thickness, viscosity, solid content, coating speed, etc. of the elastic layer material applied around the shaft core body.

  As shown in FIG. 2A, before starting the elastic layer material discharge coating from the elastic layer material discharge port on the outer peripheral surface of the shaft core body, the traveling direction (from the elastic layer material discharge port 104 of the coating head) A detachable ring-shaped member 401 is attached to the front portion (in the direction indicated by arrow A in FIG. 2). Hereinafter, this ring-shaped member 401 is referred to as a stop ring. As a result, the elastic layer material discharged from the elastic layer material discharge port at the start of coating is prevented from leaking in the relative traveling direction (arrow A direction) of the coating head with respect to the shaft core, and the shaft core outer peripheral surface The elastic layer material can be applied with high dimensional accuracy.

  A stop ring is mounted, and a detachable ring-shaped member 501 is mounted behind the elastic layer material discharge port 104 of the coating head. As a result, the elastic layer material discharged from the elastic layer material discharge port at the start of coating comes into contact with the ring-shaped member, thereby suppressing swelling of the end of the elastic layer material applied on the outer peripheral surface of the shaft core body. A stable end shape can be obtained.

  Next, with the stop ring 401 and the ring-shaped member 501 mounted as described above, an uncured elastic layer material having a viscosity of 10 Pa · s to 5000 Pa · s is brought into contact with the ring-shaped member 501 with the coating head. Coating on the outer peripheral surface of the shaft core. The viscosity is a value at 25 ° C. (hereinafter the same). By setting the viscosity of the elastic layer material to 10 Pa · s or more, the end shape of the elastic layer material coated on the outer peripheral surface of the shaft core by the ring-shaped member 501 can be prevented from becoming unstable. Moreover, it is possible to prevent the elastic layer material from leaking from the gap between the outer peripheral surface of the shaft core and the inner peripheral surface of the stop ring. As a result, after heat curing in the subsequent process, the contact state with the mating member deteriorates due to an increase in the amount of edge splashing, and the difference in outer diameter with respect to the elastic layer thickness of the elastic roller becomes large, and the elastic roller is used. It is possible to prevent a situation in which it cannot withstand. The amount of edge splash that can be preferably used as an elastic roller is less than 30 μm. By making the amount of edge splash within 30 μm, the contact state with the mating member is not biased, and local stress concentration at the end of the elastic roller is suppressed, which causes faster wear and deterioration of the part where the stress is large. Can be prevented. In addition, it is possible to prevent an adverse effect on the image due to an unbalance in the charge and developer supply due to an increase in the unevenness of the resistance value, in particular, a density unevenness. In addition, by setting the viscosity of the elastic layer material to 5000 Pa · s or less, the elastic layer material viscosity is high at the shear rate in the pipe for supplying the material, so the apparatus is heavily loaded and difficult to supply the material stably. Can be prevented.

  The ring-shaped member 501 adheres to the uncured elastic layer material during application of the elastic layer material on the outer peripheral surface of the shaft core body. Then, as shown in FIG. 2B, the coating head is removed by moving in the traveling direction (arrow A direction) from the back in the traveling direction (arrow A direction) from the elastic layer material discharge port 104 of the coating head. . At this time, the ring-shaped member 501 is preferably in contact with the uncured elastic layer material-like portion coated on the outer periphery of the shaft core. Thereby, the spread to the circumferential direction by the dead weight of the uncured elastic layer material upper end part can be prevented at the end of coating. Furthermore, by obtaining a stable end shape, waste materials can be reduced, the amount of the elastic layer material to be applied can be reduced as much as possible, and the cost of the material used can be prevented excellently. Similarly, after the coating of the elastic layer material on the outer peripheral surface of the shaft core is completed, the stop ring is removed from the back in the traveling direction (arrow A direction) from the elastic layer material discharge port 104 of the coating head. That is, the stop ring passes through the opening of the annular slit, that is, the elastic layer material discharge port. Thereby, the elastic layer material is separated from the elastic layer material discharge port after the coating is finished, and the elastic layer material remaining at the elastic layer material discharge port of the annular slit is removed. At the same time, adhesion of the elastic layer material on the inner peripheral surface of the coating head can be eliminated. In this manner, the coating head can be easily cleaned, and the production equipment can be prevented from increasing in cost. In order to acquire the said effect, it is preferable that the whole outer peripheral surface of a stop ring can contact the coating head inner peripheral surface. Therefore, it is desirable that the inner peripheral surfaces of the first annular member and the second annular member constituting the annular slit of the coating head are aligned on the same plane.

  Next, a process of curing the uncured elastic layer material with the ring-shaped member 501 attached and forming an elastic layer is performed. When the ring-shaped member is removed from the uncured elastic layer material, it is difficult to maintain a stable end shape due to the tackiness of the uncured elastic layer material. Therefore, it is preferable to cure the uncured elastic layer material while the ring-shaped member 501 is attached to form an elastic layer. Therefore, the melting point of the ring-shaped member is preferably 160 ° C. or higher. By setting the melting point of the ring-shaped member 501 to 160 ° C. or higher, in the process of curing the uncured elastic layer material while the ring-shaped member is mounted and forming the elastic layer, the ring-shaped member is melted or caused by thermal stress. Deformation of the ring-shaped member can be prevented. Thereby, the situation where the end shape of the elastic roller becomes unstable and the contact state with the mating member is deteriorated due to an increase in the amount of end portion splash can be prevented.

  For the above-described reason, it is preferable that the material of the ring-shaped member 501 has heat resistance and is not affected by the elastic layer material. Furthermore, a synthetic resin is suitable because it does not damage the coating head. Examples of the synthetic resin include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyacetal, polybutylene terephthalate, polyethylene terephthalate, polyamide, polycarbonate, polyimide, polyamideimide, polyether ether ketone, and fluororesin. Among them, fluororesins such as polytetrafluoroethylene and polycarbonate are more preferably used as materials having a melting point of 160 ° C. or higher.

  The shape of the ring-shaped member 501 is preferably such that the elastic layer material contacts the lower surface of the largest outer diameter portion (the portion having the largest outer diameter) of the ring-shaped member, and has a portion having a diameter smaller than the largest outer diameter. Preferably it is. Further, since the shape of the shaft core is preferably a columnar shape or a cylindrical shape having a hollow central portion, for example, a T-shaped hollow cylindrical shape shown in FIG. That is, the outer diameters of the two annular bottom surfaces are different, the inner diameter is the same, the two annular bottom surfaces are concentric, and the side surfaces are two curved surfaces (cylindrical surfaces), below (mounted on the coating head) B) A convex solid.

  The shape which chamfered to the ridge part of the ring-shaped member may be sufficient. 5 (b), (c) and (d) show examples of C-chamfered ring-shaped members, and FIGS. 5 (e), (f) and (g) show examples of R-chamfered ring-shaped members, respectively.

  Although the shape and dimensions of the ring-shaped member 501 depend on the physical properties of the elastic layer material used, the adhesion between the elastic layer material and the ring-shaped member is improved, and the elastic layer material coated on the outer peripheral surface of the shaft core body is used. It can be set in view of improving the accuracy of the end shape. Moreover, in order to acquire the said effect, the ring-shaped member 501 may be used independently and multiple may be used simultaneously.

The maximum outer diameter of the ring-shaped member is D _max (mm), the minimum outer diameter is D _min (mm), the inner diameter is r (mm), and W1 (mm) is W1 = (D _max −r) / 2, W2 ( mm) is W2 = (D _min −r) / 2, and 0 <W2 / W1 ≦ 0.5 is preferable. The maximum outer diameter _Dmax , the minimum outer diameter _Dmin , and the inner diameter r of the ring-shaped member 501 can be determined in accordance with the inner diameter L of the coating head and the outer diameter d of the shaft core body.

FIG. 10 is a schematic cross-sectional view for explaining the arrangement when the ring-shaped member 501 and the stop ring 401 are mounted (before the coating process). As shown in FIG. 10, W1 is a distance from the outer end of the maximum outer diameter portion to the inner peripheral surface, and W1 is a dominant value for stabilizing the end shape. When W1 is set to an extremely large value, the maximum outer diameter _Dmax of the ring-shaped member 501 increases, and interference with the cylindrical surface forming the minimum diameter portion inside the first annular member of the coating head occurs. There is. As a result, smooth sliding during application of the elastic layer material is not performed, and it may be difficult to form a stable end shape. Here, the outer diameter d of the shaft core can be determined as appropriate, but is usually in the range of 4 mm to 30 mm. Moreover, although the coating head inner diameter L can also be determined suitably, it is the range of 5 mm-40 mm normally. For the above reasons, it is preferable that W1 and W2 of the ring-shaped member 501 are in the range of 0 <W2 / W1 ≦ 0.5. More preferably, W1 and W2 are in a range of 0.1 <W2 / W1 <0.4. If W2 / W1 is greater than 0.1, W2 can be secured to some extent relative to W1, and the ring-shaped member 501 can be stably upright. Further, if W2 / W1 is smaller than 0.4, the size of W1 can be secured to some extent, and the contact area between the uncured elastic layer material and the ring upper member 501 is increased, which is excellent for the end shape. Can be manufactured.

  When the ring-shaped member 501 is attached to the coating head, the maximum outer diameter portion of the ring-shaped member 501 is rearward in the direction of travel of the coating head from the end of the opening direction of the opening of the annular slit of the coating head. It is preferable that it is located in.

The maximum opening width of the annular slit of the coating head is s _max (mm), and the vertical line from the maximum outer diameter portion of the ring-shaped member 501 is from the front end in the traveling direction of the annular slit opening of the coating head. Let h (mm) be the shortest distance to the point that intersects the horizon. At this time, it is preferable that s _max and h satisfy 1.0 ≦ h / s _max ≦ 3.0. More preferably, h is in the range of 1.5 ≦ h / s _max ≦ 2.0.

The maximum opening width (slit width) s _max of the annular slit of the coating head is appropriately selected according to the film thickness, viscosity, solid content, coating speed, etc. of the elastic layer material applied around the shaft core body. The s _max is usually set to 0.1 mm to 5.0 mm, more preferably 0.5 mm to 2.0 mm. The maximum opening width (slit width) s _max here is, as shown in FIG. 10, the rear end portion of the first annular member 101 in the traveling direction (arrow A direction) and the traveling direction of the second annular member 102. This is the distance from the front end.

  h is the shortest distance to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects the horizontal line from the front end portion in the traveling direction of the annular slit opening of the coating head. This h can be selected according to the setting of the slit width, but is preferably set to 0.1 mm to 15.0 mm, more preferably 0.5 mm to 7.0 mm. Here, the shortest distance h to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects the horizontal line from the front end of the annular slit opening of the coating head is the ring shape. This is a portion indicated by symbol h in FIG. 10 when the member 501 is mounted.

When h / s _max is 1.0 or more, the surface having the maximum outer diameter of the ring-shaped member 501 is not in contact with the slit position for discharging the elastic layer material, and does not hinder the discharge of the elastic layer material. Thereby, it can prevent that the dimensional accuracy of the elastic layer material of a shaft core outer peripheral surface falls, and it becomes easy to manufacture a favorable elastic roller. Further, when h / s _max is 3.0 or less, it is possible to prevent the elastic layer material from being applied to the outer peripheral surface of the shaft core body without contacting the lower surface of the surface having W1 of the ring-shaped member 501. It becomes easy to manufacture a roller having an excellent end shape.

  The inner diameter r of the ring-shaped member 501 is preferably in the range of d + 0.02 (mm) <r <d + 0.40 (mm), where d (mm) is the outer diameter of the shaft core.

  If the inner diameter r of the ring-shaped member 501 is larger than d + 0.02 (mm) and smaller than d + 0.40 (mm), the uncured elasticity between the shaft core outer peripheral surface and the ring-shaped member 501 inner peripheral surface. Infiltration of the layer material can be prevented. From this, the behavior of the ring-shaped member 501 can be stabilized, and the shape of the end portion of the elastic layer material on the outer peripheral surface of the shaft core body can be adjusted.

  If the inner diameter r of the ring-shaped member 501 is larger than d + 0.02, due to a dimensional error of the ring-shaped member 501 and the shaft core body, the outer surface of the shaft core and the inner surface of the ring-shaped member 501 come into contact with each other during the coating process. Can be prevented. As a result, it is possible to prevent the ring-shaped member 501 from moving during coating and the shape of the elastic layer material end portion of the outer peripheral surface of the shaft core body from being deteriorated. In addition, when the inner diameter r of the ring-shaped member 501 is less than d + 0.40, W1 of the ring-shaped member 501 is reduced to prevent the contact area between the outer peripheral surface of the shaft core body and the elastic layer material end. This makes it easy to produce a roller that is superior to the end shape.

  Alternatively, if the inner diameter r of the ring-shaped member 501 is d−0.02 (mm) <r <d, the ring-shaped member 501 can be used by being press-fitted into the shaft core. When the inner diameter r of the ring-shaped member 501 exceeds d−0.02 (mm), it can be prevented that the mounting of the ring-shaped member 501 on the shaft core becomes difficult.

Moreover, as shown in FIG.5 (d), the inner peripheral surface of the ring-shaped member 501 may be a discontinuous surface of two or more steps. At this time, the inner diameter of the ring-shaped member 501 has a maximum inner diameter r _max (mm) and a minimum inner diameter r _min (mm). If the inner circumferential surface of the ring-shaped member 501 is a convex shape toward the mandrel, W1 (mm) is _{W1 = (D max -r max)} / 2, W2 (mm) is W2 = (D _min - r _min ) / 2. Also, when the inner peripheral surface of the ring-shaped member 501 is a convex shape toward the outer circumferential surface, W1 (mm) is _{W1 = (D max -r min)} / 2, W2 (mm) is W2 = (D _min -R _max r _min ) / 2. In any case, the minimum inner diameter r _min of the ring-shaped member 501 is d + 0.02 (mm) <r _min <d + 0.40 (mm), where d (mm) is the outer diameter of the shaft core body. A range is preferable. When the ring-shaped member is used by being press-fitted, the inner diameter r _min of the ring-shaped member is preferably in the range of d−0.02 (mm) <r _min <d.

  FIG. 3 is a schematic view showing an example of an apparatus suitable for carrying out the production method of the present invention. In this coating apparatus, as shown in FIG. 3, a column 302 is attached substantially vertically to the gantry 301, and a precision ball screw 303 is attached substantially vertically to the gantry 301 and the column 302. The LM guide 304 connects the linear guide 314 and the precision ball screw 303, and a rotary motion is transmitted from the servo motor 305 through the pulley 306 so that the LM guide 304 can move up and down. The column 302 is provided with a coating head 308 for discharging and applying uncured elastic layer material from an elastic layer material discharge port formed in an annular slit on the outer periphery of the shaft core body 61. Further, a bracket 307 is attached to the LM guide 304, and a shaft core lower holding shaft 309 for holding and fixing the shaft core body 102 is attached to the bracket 307 substantially vertically. The central axis of the shaft core upper holding shaft 310 that holds the shaft core body 102 of the opposite roller is attached to the upper portion of the bracket 307, and the shaft core upper holding shaft 310 faces the shaft core lower holding shaft 309. And it arrange | positions so that it may become substantially concentric, and the shaft core body is hold | maintained. Further, the central axis of the coating head 308 is supported so as to be parallel to the moving direction of the shaft core lower holding shaft 309 and the shaft core upper holding shaft 310. Further, when the lower shaft core holding shaft 309 and the upper shaft core holding shaft 310 are moved, the center axis of the elastic layer material discharge port formed in an annular slit opened inside the coating head 308 and the lower shaft core body The central axis of the holding shaft 309 and the shaft core holding shaft 310 is adjusted so as to be substantially concentric. With such a configuration, the central axis of the elastic layer material discharge port formed in the annular slit of the coating head 308 can be made substantially concentric with the central axis of the shaft core body. A uniform gap is formed between the outer peripheral surface of the shaft core body 61.

  The elastic layer material supply port 311 is connected to the material supply valve 313 via a piping 312 for conveying the elastic layer material. A mixing mixer, a material supply pump, a material dispensing device, a material tank (not shown), etc. (not shown) are provided in front of the material supply valve 313, and a fixed amount (a constant amount per unit time) of the elastic layer material can be discharged from the supply port 311. It is said. A certain amount of the elastic layer material is weighed from the material tank by a material dispensing device and mixed by a mixing mixer. Thereafter, the elastic layer material mixed by the material supply pump is sent from the material supply valve 313 to the supply port 311 via the pipe 312.

  In order to make the layer thickness of the elastic layer material constant, the discharge amount from the elastic layer material discharge port and the supply amount from the material supply pump are made constant, and the shaft core body holding shaft is moved in the direction of the central axis of the shaft core body (particularly Is moved vertically). As a result, a cylindrical (roll-shaped) uncured material layer made of an elastic layer material is formed on the outer peripheral surface of the shaft core body. In this case, the coating head 308 is fixed and the shaft core 61 moves in the axial direction. On the other hand, the shaft core body 61 is fixed, and the coating head can be moved in the direction of the central axis of the shaft core body. That is, by moving the coating head relative to the shaft core body, a cylindrical (roll-shaped) uncured material layer made of an elastic layer material is formed on the outer surface of the shaft core body.

  Next, the uncured elastic layer material formed on the outer peripheral surface of the shaft core is cured to become an elastic layer, and an elastic roller is manufactured. At this time, since the uncured elastic layer material having a cylindrical shape (roll shape) has adhesiveness, it is preferable to perform the heat treatment by a non-contact heat treatment method.

  Examples of the heat treatment method include an infrared heating method, a hot air heating method, and a nichrome heat heating method. In particular, infrared heating is preferred because the apparatus is simple and the layer of the uncured product can be uniformly heat-treated in the axial direction. At this time, heat treatment can be uniformly performed in the circumferential direction by fixing the infrared heating device and rotating the axial core body provided with the cylindrical (roll-shaped) uncured material layer in the circumferential direction. The heat treatment temperature on the surface of the elastic layer material is preferably 100 to 250 ° C. at which the curing reaction starts although it depends on the material used. For example, when performing infrared heating, the distance between the infrared heating device and the layer of the uncured elastic layer material, the output, etc. may be adjusted according to the material properties (thermal conductivity, specific heat, etc.). Moreover, what is necessary is just to adjust the temperature and direction of a hot air when performing hot air heating.

  Here, for the purpose of stabilizing physical properties of the elastic layer after curing, removing reaction residues and unreacted low-molecular components in the elastic layer, etc., secondary curing is performed in which the elastic layer formed by curing is further subjected to heat treatment or the like. It may be done.

The elastic roller manufactured according to the present invention can be used as a developing roller. A schematic diagram of an example is shown in FIG. 6A shows a cross section parallel to the longitudinal direction of the developing roller, and FIG. 6B shows a cross section perpendicular to the longitudinal direction.

As the material of the mandrel 61 of the current image roller, can be appropriately selected from electrically conductive material, carbon steel, alloy steel and cast iron, from such as a conductive resin, it may be appropriately selected and used. Here, examples of the alloy steel include stainless steel, nickel chrome steel, nickel chrome molybdenum steel, chrome steel, chromium molybdenum steel, nitriding steel to which Al, Cr, Mo, and V are added, but from the viewpoint of strength. Metal is preferable. Furthermore, as a countermeasure against rust, the shaft core material can be plated and oxidized. As the type of plating, both electroplating and electroless plating can be used, but electroless plating is preferable from the viewpoint of dimensional stability. Examples of the electroless plating used here include nickel plating, copper plating, gold plating, Kanigen plating, and other various alloy platings. Examples of the nickel plating include Ni-P, Ni-B, Ni-WP, and Ni-P-PTFE composite plating. The thickness of the plating film is preferably 0.05 μm or more, more preferably 0.1 μm to 30 μm.

  Further, the developing roller is always in pressure contact with the photosensitive drum, the developing blade, the toner, and the like. For this reason, in order to reduce the damage given to these members, it is important to obtain a good image by using a material having a low hardness and a small compression set. Further, it is desirable that the surface of the developing roller has wear resistance and the like and has high durability. For this reason, the developing roller has a configuration in which an elastic layer 62 is provided around the shaft core body 61.

  At this time, the hardness of the elastic layer 62 is desirably Asker C hardness of 10 to 80 degrees for the above reason. If the hardness of the elastic layer is 10 degrees or more, contamination of the photosensitive drum can be prevented. Further, if the hardness of the elastic layer is 80 degrees or less, it is possible to suppress damage to the toner when coming into contact with the toner, and it is possible to prevent the quality of the output image from being deteriorated. The elastic layer 62 does not need to be a single layer, and may be a multilayer.

  Examples of materials used for the elastic layer 62 include epoxy rubber, diallyl phthalate rubber, polycarbonate rubber, fluorine rubber, polypropylene rubber, urea rubber, melamine rubber, silicon rubber, polyester rubber, styrene rubber, vinyl acetate rubber, phenol rubber, polyamide rubber, Examples thereof include fiber base rubber, urethane rubber, silicone rubber, acrylic urethane rubber, and water-based rubber. These materials can be used alone or in combination. Furthermore, foams of these materials may be used for the elastic layer.

  In order to impart conductivity to the elastic layer, a conductivity imparting agent based on an ionic conduction mechanism or a conductivity imparting agent based on an electronic conduction mechanism can be included in the elastic layer.

Examples of the conductivity-imparting agent by the ionic conduction mechanism include LiCF ₃ SO ₃ , NaClO ₄ , LaClO ₄ , LiAsF ₆ , LiBF ₄ , NaSCN, KSCN, NaCl, etc. Group 1 metal salts, NH ₄ Cl, Ammonium salts such as (NH ₄ ) ₂ SO ₄ and NH ₄ NO ₃ , salts of Group 2 metals of the periodic table such as Ca (ClO ₄ ) ₂ and Ba (ClO ₄ ) ₂ , these salts and 1,4- Complexes with polyhydric alcohols such as butanediol, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol and their derivatives, salts thereof with ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, polyethylene glycol monomethyl ether, polyethylene glycol mono Complexes with monools such as ethyl ether, Examples include cationic surfactants such as quaternary ammonium salts, anionic surfactants such as aliphatic sulfonates, alkyl sulfate esters, and alkyl phosphate esters, and amphoteric surfactants such as betaines. it can.

  Examples of the conductivity imparting agent by the electronic conduction mechanism include carbon-based materials such as carbon black and graphite, metals or alloys such as aluminum, silver, gold, tin-lead alloy, copper-nickel alloy, zinc oxide, titanium oxide. Examples thereof include metal oxides such as aluminum oxide, tin oxide, antimony oxide, indium oxide, and silver oxide, and substances obtained by applying conductive metal plating such as copper, nickel, and silver to various fillers. These conductivity-imparting agents based on the ion conduction mechanism and the electron conduction mechanism can be used alone or in a mixture of two or more in the form of powder or fiber. Among these, carbon black is preferable from the viewpoint of easy control of conductivity and economy.

  In addition, the surface layer 63 may be formed on the outer periphery of the elastic layer 62 in order to improve wear resistance and the like. Similarly to the elastic layer, the surface layer does not have to be a single layer, and may be a multilayer.

  Next, the surface layer 63 will be described. A surface layer 63 may be formed around the elastic layer 62 in order to optimize the roller surface.

  Materials used for the surface layer 63 are epoxy resin, diallyl phthalate resin, polycarbonate resin, fluororesin, polypropylene resin, urea resin, melamine resin, silicon resin, polyester resin, styrene resin, vinyl acetate resin, phenol resin, polyamide resin , Fiber based resins, urethane resins, silicone resins, acrylic urethane resins, water based resins, and the like. It is also possible to use a combination of two or more of these. Among these, it is particularly preferable to use a nitrogen-containing compound such as a urethane resin or an acrylic urethane resin because the toner can be stably charged.

  The urethane resin used here can be obtained from an isocyanate compound and a polyol.

  Diisocyanate-4,4′-diisocyanate, 1,5-naphthalene diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, p-phenylene diisocyanate as isocyanate compounds Isophorone diisocyanate, carbodiimide-modified MDI, xylylene diisocyanate, trimethylhexamethylene diisocyanate, tolylene diisocyanate, naphthylene diisocyanate, paraphenylene diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl polyisocyanate and the like can be used. Moreover, these mixtures can also be used and the mixing ratio may be any ratio.

  In addition, as the polyol used here, as a divalent polyol (diol), ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, hexanediol, neopentyl glycol, 1,4-cyclohexanediol 1,4-cyclohexanedimethanol, xylene glycol, triethylene glycol, etc., and trivalent or higher polyols include 1,1,1-trimethylolpropane, glycerin, pentaerythritol, sorbitol, etc. be able to. Furthermore, polyols such as high molecular weight polyethylene glycol, polypropylene glycol, and ethylene oxide-propylene oxide block glycol obtained by adding ethylene oxide and propylene oxide to diol, triol, and the like can also be used. Moreover, these materials can also be mixed and used, and the mixing ratio may be any ratio.

  In addition, as a method for applying the surface layer 63, generally known coating methods such as a ring coating method, a dipping method, a roll coating method, and a spray coating method can be used, but the thickness of the surface layer 63 can be easily controlled. The dipping method is often used for such reasons. In the dipping method, it is preferable to use a material having a viscosity of 5 cps (0.005 Pa · s) to 50 cps (0.05 Pa · s). When the viscosity is 5 cps or more, the shape can be prevented from collapsing until the material is cured and stabilized, and the specifications as a developing roller can be satisfactorily satisfied. Further, when the viscosity of the material is 50 cps or less, it becomes easy to form the surface layer 63 uniformly on the surface of the elastic layer 62.

  Further, the surface layer 63 can be used with conductivity imparted. As a method for imparting conductivity, it is possible to use a method similar to the above-described method for making the elastic layer conductive.

  Furthermore, the thickness of the surface layer 63 is preferably 1 μm to 500 μm. More preferably, the thickness of the surface layer 63 is 1 μm to 50 μm. When the surface layer 63 is 1 μm or more, it is possible to prevent the role of the surface layer from being lost due to deterioration due to wear or the like when an image is output repeatedly. Further, when the surface layer 63 is 500 μm or less, it is possible to prevent the roller surface from becoming hard and promoting toner deterioration and causing toner fusion.

  Also, if the electrical resistance unevenness of the entire developing roller is smaller, the toner with a uniform charge can be sent from the developing roller to the photosensitive drum, so that the transferability of the toner is stabilized, so that a good image is obtained. Can be obtained. Here, the uneven resistance of the developing roller refers to a value obtained by “1− (minimum resistance value of developing roller / maximum resistance value of developing roller)”. It is preferable that the resistance unevenness in the developing roller is at least less than 0.7 (including zero). More preferably, the resistance unevenness is suppressed to less than 0.3 (including zero). The measurement of the resistance unevenness will be specifically described later.

  Further, the shape is given as a characteristic required for the developing roller. For example, when the circumferential deviation of the developing roller is large, the fluctuation in the nip width between the developing roller and the photosensitive drum becomes large in one round of the developing roller. When the variation in the nip width is large as described above, the toner conveying force to the drum is uneven, and the image may be shaded. In order to prevent this, it is better that the circumferential deviation of the developing roller is smaller. Specifically, if the value of (maximum value) − (minimum value) between the (maximum value) and the (minimum value) of the distance from the center of the shaft core to the developing roller surface in one round of the developing roller is 0 to 50 μm. It is possible to suppress the shading on the image. Further, if the value of (maximum value) − (minimum value) is 0 to 30 μm, the density on the image is almost uniform, and excellent image quality can be output.

  The roughness on the surface of the developing roller greatly affects the toner conveying force. Therefore, it is desirable that the Ra of the developing roller surface in the standard of JIS B 0601: 1994 surface roughness is 0.5 μm to 3.0 μm. When Ra is 0.5 μm or more, the toner conveying force can be prevented from being reduced, and a good image density can be obtained. When the thickness is 3.0 μm or less, it is possible to prevent the toner from being transported in a large amount and transporting a large amount of toner, so that the toner remains on the photosensitive drum and the image is deteriorated. In addition, it is possible to transport toner uniformly and to output an image having a uniform density when the roughness unevenness is smaller around the developing roller. Therefore, the roughness unevenness in the developing roller is desirably 0 to 0.6. More preferably, the roughness unevenness is in the range of 0 to 0.3. Here, the roughness unevenness refers to a value obtained by subtracting the minimum roughness from the maximum roughness in the developing roller.

The elastic roller manufactured according to the present invention can be used as a charging roller. An example of the schematic is shown in FIG. FIG. 7A shows a cross section parallel to the longitudinal direction of the developing roller, and FIG. 7B shows a cross section perpendicular to the longitudinal direction.

  The charging roller desirably has an appropriate elasticity in order to ensure good uniform adhesion to the photosensitive drum. Therefore, the charging roller has a configuration in which an elastic layer 72 is provided around the shaft core 71 in the same manner as the developing roller. The hardness of the elastic layer 72 used for the charging roller is desirably Asker C hardness of 20 to 40 degrees for the purpose of ensuring adhesion. At this time, like the developing roller, the elastic layer 72 does not have to be a single layer, and may be a multilayer. In addition, when the conductivity is imparted to the elastic layer 72 as in the developing roller, the conductivity of the elastic layer 72 is adjusted by adding a conductive agent such as carbon black.

  Further, a surface layer 73 may be provided on the surface of the elastic layer 72 in order to maintain the slipperiness and smoothness of the charging roller surface. The surface layer 73 does not have to be a single layer like the elastic layer, and may have a multilayer structure.

  Specific materials for the elastic layer 72 used for the charging roller include, for example, natural rubber, ethylene propylene diene methylene rubber (EPDM), styrene-butadiene rubber (SBR), silicone rubber, urethane rubber, epichlorohydrin rubber, isoprene rubber ( IR), butadiene rubber (BR), nitrile-butadiene rubber (NBR), chloroprene rubber (CR), and other synthetic rubbers, as well as polyamide rubber and fluorine rubber. These materials can be used alone or in combination. Moreover, you may use the foam of these materials for an elastic layer.

  Examples of the material used for the surface layer 73 include resins such as polyamide resin, urethane resin, acrylic resin, fluorine resin, and silicone resin, epichlorohydrin resin, chloroprene resin, and acrylonitrile resin. These materials can be used alone or in combination. As a method for coating the surface layer material, generally known coating methods such as a ring coating method, a dipping method, a roll coating method, and a spray coating method can be used as in the developing roller.

  Regardless of whether the charging roller is in contact or non-contact with the photosensitive drum, if the surface of the charging roller is rough, subtle uneven charging occurs due to the unevenness. As a result, image defects may occur. Therefore, the surface of the charging roller is preferably smoother, and it is desirable that Rz in the standard of JIS B 0601 surface roughness is 0 to 30 μm. In particular, the thickness is desirably 15 μm or less.

  The thickness of the surface layer is desirably 1 μm to 500 μm. When the thickness of the surface layer is 1 μm or more, a surface layer that can withstand friction with the photosensitive drum can be easily obtained. Further, when the thickness of the surface layer is 500 μm or less, the function of the elastic layer can be fully utilized.

  In addition, when the electrical resistance unevenness of the entire charging roller is smaller, the photosensitive drum can be uniformly charged, so that a good image can be obtained.

  In addition, when the circumferential deviation of the charging roller is large, the variation in the nip width between the charging roller and the photosensitive drum within the circumference of the charging roller becomes large, and the photosensitive drum may not be uniformly charged. In order to prevent this, it is better that the circumferential deflection of the charging roller is smaller. Specifically, if the difference between (maximum value) and (minimum value) (maximum value) − (minimum value) of the distance from the center of the shaft core to the charging roller surface in one round of the charging roller is 0 to 30 μm. This range is preferable because the photosensitive drum can be charged almost uniformly.

In addition, when the roller obtained by the production method of the present invention is used as a charging roller, it is important to function as an electrode, and it is elastic and obtains a sufficient contact state, and at the same time charges a moving charged object. It is necessary to have a sufficiently low resistance. However, on the other hand, it is necessary to prevent voltage leakage in the case where a defect site such as a pinhole exists in the member to be charged. Therefore, when an electrophotographic photosensitive drum is used as the member to be charged, a resistance of 1 × 10 ³ to 1 × 10 ⁹ Ω · cm is required as the resistance value of the elastic layer in order to obtain sufficient chargeability and leakage resistance. It is desirable to have.

  According to the present invention, an elastic layer, which is a hardened layer of a cylindrical shape (roll shape) made of a high-viscosity material, is provided with low dimensional accuracy on the outer peripheral surface of the shaft core body, and the shape of the elastic layer end is stable. An elastic roller can be obtained.

An example of a process cartridge and an electrophotographic apparatus equipped with a developing roller manufactured according to the present invention is shown as a schematic diagram in FIG. This will be described below with reference to FIG.

  In this image forming apparatus, four image forming units 8a to 8d that respectively form yellow, cyan, magenta, and black images are provided in a tandem manner. The specifications of the photoconductor 1, the charging device 2, the image exposure device 3 (writing beam in the figure), the developing device 4, the cleaning device 5, the image transfer device 6 (transfer roller in the figure), etc. are slightly different according to the characteristics of each color toner. Although there is a difference in adjustment, these four image forming units 8a to 8d are the same in the basic configuration. Further, the photosensitive member 1, the charging device 2, the developing device 4, and the cleaning device 5 are integrated to form a process cartridge.

  The developing device 4 includes a developing container 10 that contains a one-component toner 9 and a developing roller 60 that is located in an opening extending in the longitudinal direction in the developing container 10 and that is opposed to the photoreceptor 1. The electrostatic latent image on the photoreceptor 1 is developed and visualized. Further, a toner supply roller 11 that supplies the one-component toner 9 to the developing roller 60 and scrapes the one-component toner 9 carried on the developing roller 60 without being used for development from the developing roller 60 is provided. Further, a developing blade 12 that regulates the amount of the one-component toner 9 on the developing roller 60 and frictionally charges is provided.

The surface of the photoreceptor 1 is uniformly charged to a predetermined polarity / potential by the charging device 2, and image information is irradiated from the image exposure device 3 as a beam to the surface layer of the charged photoreceptor 1, thereby forming an electrostatic latent image. Is formed. Then, one-component toner from the developing device 4 having a current image roller 60 is supplied onto the formed electrostatic latent image, a toner image is formed on the surface of the photosensitive member 1. The toner image is transferred to a transfer material (paper) 7 such as paper supplied in synchronization with the rotation when the toner image comes to a portion facing the image transfer device 6 as the photoconductor 1 rotates.

  In the drawing, four image forming units 8 a to 8 d are formed in a linked manner so that predetermined color images are superimposed on one transfer material 7. Therefore, the transfer material 7 is synchronized with the image formation of each image forming unit. That is, the image formability is synchronized with the insertion of the transfer material 7. For this purpose, the transfer roller 13 for transporting the transfer material 7 is sandwiched between the photosensitive member 1 and the image transfer device 6 so that the drive roller 14, the tension roller 15, and the driven roller 16 of the transfer conveyor belt 13 are sandwiched between them. It is laid around. The transfer material 7 is conveyed to the transfer conveyance belt 13 while being electrostatically adsorbed by the action of the adsorption roller 17. Reference numeral 18 denotes a supply roller for supplying the transfer material 7.

  The transfer material 7 on which the image has been formed is peeled off from the transfer conveyance belt 13 by the action of the peeling device 19 and sent to the fixing device 20, and the toner image is fixed on the transfer material 7 and printing is completed. On the other hand, the photosensitive member 1 after the transfer of the toner image to the transfer material 8 is further rotated, the surface of the photosensitive member 1 is cleaned by the cleaning device 5, and is discharged by a discharging device (not shown) if necessary. Thereafter, the photoreceptor 1 is used for the next image formation. In the figure, reference numerals 21 and 22 denote bias power supplies to the suction roller 17 and the image transfer device 6, respectively.

Here, the description has been made with respect to the apparatus for directly transferring the toner images of the respective colors onto the tandem type transfer material. However, the elastic roller manufactured according to the present invention is suitably used in an electrophotographic image forming apparatus as a developing roller (or a charging roller). ). As an example of an image forming apparatus that can use an elastic roller manufactured according to the present invention, a monochrome image forming apparatus for black and white, a toner image of each color is once superimposed on a transfer roller or a transfer belt, and a color image is formed on a transfer member. Examples thereof include an image forming layer that is collectively transferred. In addition, an image forming apparatus in which each color developing unit is arranged on a rotor or arranged in parallel with a photosensitive member may be used. Further, instead of the process cartridge, a photoreceptor, a charging device, a developing device, or the like may be directly incorporated in the image forming apparatus.

  Hereinafter, the present invention will be described in more detail with reference to examples. First, various evaluation and measurement methods performed in Examples will be described.

(Image evaluation (density unevenness))
Electrophotographic process cartridge (nominal life: 6000 sheets, A4 size, 5% printing rate, print cartridge black, cyan, magenta, yellow, manufactured by Hewlett-Packard Company, trade name: print cartridge black, print cartridge cyan, print cartridge magenta, print cartridge Yellow) was prepared. In this process cartridge, the roller prepared in each example was incorporated as a developing roller for each of the square colors. This process cartridge is one in which the following means are integrated into a cartridge. Means for uniformly charging a photosensitive drum as an image carrier, means for forming a latent image by selective exposure to the photosensitive drum, means for realizing the latent image with toner as a developer, and transferring a toner image to a transfer material And a means for cleaning residual toner on the photosensitive drum after transfer.

Next, this electrophotographic process cartridge was incorporated into an electrophotographic image forming apparatus (trade name: Color LaserJet 3700, manufactured by Hewlett-Packard Company). Then, using this image forming apparatus, an image (solid image, halftone image) was output, and density unevenness (roller pitch) was evaluated as follows.
A: When all the images are good visually.
○: Density unevenness is slightly confirmed with solid and halftone, but there is no practical problem.
Δ: When density unevenness is confirmed in all images.

(Measurement and evaluation of edge amount of elastic roller)
The amount of splash at the end of the elastic roller is determined by a non-contact laser length measuring device (manufactured by Keyence, product name: LS-5000) which is arranged perpendicular to the rotation axis by rotating the elastic roller with the central axis of the shaft core as the rotation axis. The average outer diameter was measured and determined. The average outer diameter here is an average value of the outer diameters of the 180 elastic layer portions measured by rotating the elastic roller by 2 °. The average outer diameter value of 40 points is obtained at a pitch of 1 mm in the longitudinal direction from both ends of the elastic layer, and the maximum value among the values is defined as the value of the end amount of the elastic roller. Evaluation was performed as follows.
A: The value of the amount of splash at the end of the elastic roller (maximum average outer diameter) is less than 30 μm.
◯: The value of the amount of splash at the end of the elastic roller (maximum average outer diameter) is 30 μm or more and less than 100 μm.
(Triangle | delta): The value of the edge part amount (maximum average outer diameter) of an elastic roller is 100 micrometers or more.

(Measurement and evaluation of resistance unevenness of elastic roller)
Details will be described with reference to FIG. A load of 500 g (4.9 N) is applied to both ends of the shaft core of an elastic roller (developing roller 60 in the figure, but charging roller 70), and pressed against a metal drum 92 rotating at 60 rpm. Then, a voltage of 100 V is applied between the shafts of the metal drum 92 and the elastic roller 60, and the resistance value of the elastic roller is calculated from the value of the current flowing through the 10 kΩ resistor connected in series with the elastic roller. The average value of the maximum value and the minimum value of the elastic roller resistance in one round is defined as the resistance value of the elastic roller. Further, the maximum and minimum resistance values at the measurement points obtained by dividing the elastic roller (elastic layer) into 20 in the longitudinal direction are taken, and the value of “1- (minimum resistance value / maximum resistance value)” is set to that elastic roller. Resistance unevenness.

If the resistance unevenness is 0 or more and less than 0.3, ◎,
When resistance unevenness is 0.3 or more and less than 0.7, ○,
When the resistance unevenness was 0.7 or more and 1.0 or less, it was evaluated as Δ.

(Measurement of viscosity of uncured elastic layer material)
For the viscosity measurement, Rheo Stress 600 (trade name) manufactured by Haake was used.

  About 1 g of an uncured elastic layer material was sampled and placed on a sample table, a cone plate (diameter 35 mm, inclination angle 1 °) was gradually brought closer, and a measurement gap was set at a position of about 50 μm from the sample table. At that time, the elastic layer material extruded around was removed so as not to affect the measurement. The temperature of the sample stage was set so that the sample temperature was 25 ° C., and the measurement was started after being left for 10 minutes after setting the sample. The value obtained by dividing the shear rate applied to the sample from 0.1 s-1 to 10 and changing the shear stress at the shear rate of 1 s-1 by the shear rate of 1 s-1 in increments of 0.2 s-1. Viscosity.

(Measuring melting point of ring-shaped member)
A method for measuring the melting point of the ring-shaped member will be described below. The melting point refers to the outflow start temperature measured by the following method. The measurement was performed as follows using a flow tester CFT-500D type (trade name, manufactured by Shimadzu Corporation). An extrusion load of 10 kg (98 N) is applied with a die (nozzle) diameter of 1 mm and a thickness of 1 mm, and after a preheating time of 420 seconds at an initial set temperature of 50 ° C., the sample is heated at a constant rate of 4 ° C./min. As a sample, powder obtained by pulverizing the same material as that of the ring-shaped member to 1 to 3 g as necessary was used, and the plunger cross-sectional area was 1.0 cm ² .

  As the temperature rises at a constant speed, the sample is gradually heated and starts to flow out. When the temperature is further raised, the sample in a molten state largely flows out, and the plunger lowering stops and ends. At this time, the temperature at which the sample started to flow out was defined as the outflow start temperature.

  The measurement method is as described above, but each measurement condition can be changed based on the conditions of this example depending on the type of material.

[Example 1]
In producing the elastic roller, the shaft core is nickel-plated on a round bar-shaped iron shaft having an outer diameter of 6 mm, and further coated with a primer DY35-051 (trade name: manufactured by Toray Dow Corning Co., Ltd.) having a thickness of about 1 μm. What was baked for 30 minutes at 150 degreeC was used. As the coating apparatus, a coating apparatus having the structure shown in FIG. 3 was used.

  Carbon black (trade name: MA11, manufactured by Mitsubishi Chemical Corporation) is added to 100 parts by mass of each of the liquids A and B of addition reaction crosslinkable liquid silicone rubber (trade name: DY35-1265, manufactured by Toray Dow Corning) 8 A part by mass was added and defoamed with a planetary mixer for 30 minutes. Thereafter, liquid A and liquid B blended with carbon black are respectively set in the raw material tanks attached to the coating apparatus, and sent to a static mixer using a pressure pump, and liquids A and B are 1: 1 on a mass basis. This silicone rubber mixed solution was mixed and used as an elastic layer material. The viscosity was 545 Pa · s.

The shaft core body is clamped by the shaft core body holding shaft and the shaft core body lower holding shaft of the coating apparatus, and these shaft core body holding shafts are raised vertically from the bottom to the top at a speed of 10 mm / s. Moved. At the same time, the silicone rubber mixture is discharged from the annular slit of the coating head having the configuration shown in FIG. 2 at 840 mm ³ / s, and an uncured elastic layer material is cylindrically formed on the outer peripheral surface of the shaft core (roll Shape).

  The inner diameter (L) of the coating head was set to 12.1 mm (the inner peripheral surfaces of the first annular member 101 and the second annular member 102 form the same surface). The width of the annular slit (elastic layer material discharge port) was uniform at 1.0 mm. Therefore, smax is 1.0 mm.

  Prior to coating, a stop ring 401 was attached to the coating head. The stop ring has a hollow cylindrical ring shape as shown in FIG. At this time, the stop ring was positioned ahead of the traveling direction (arrow A direction) from the annular slit of the coating head.

  Further, before coating, a ring-shaped member 501 (having a shape shown in FIG. 5A) called an upper ring was attached to the coating head. At this time, the maximum outer diameter portion of the ring-shaped member 501 was positioned behind the annular slit of the coating head in the traveling direction.

The inner diameter r of the ring-shaped member 501 is r = 6.1 mm, the maximum outer diameter D _max is D _max 12.0 mm, and the minimum outer diameter D _min is D _min = 8.46 mm. W1 calculated from the maximum outer diameter and the inner diameter is W1 = 2.95 mm, and W2 calculated from the minimum outer diameter and the inner diameter is W2 = 1.18 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm. The material of this ring-shaped member is polycarbonate. In addition, such a method of mounting the ring-shaped member having the inner diameter r larger than the outer diameter of the shaft core body is referred to as “gap fitting” (hereinafter the same).

  Next, infrared heating was applied to the uncured elastic layer. Infrared heating lamp (trade name: manufactured by Hybeck, trade name: HYL25) is heat treatment temperature (surface temperature of the object to be heated. Hereinafter, heat treatment temperature refers to the surface temperature of the object to be heated) 200 ° C., lamp and uncured product It arrange | positioned so that the distance with the layer surface of might be set to 60 mm. Then, the shaft core provided with the uncured material layer was heated for 4 minutes while rotating in the circumferential direction at 60 rpm to cure the uncured elastic layer material to obtain an elastic layer.

  Thereafter, secondary curing at 200 ° C. for 4 hours in an electric furnace is performed 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. went.

  In this way, an elastic roller having an elastic layer on the outer periphery of the shaft core was manufactured.

Thereafter, a surface layer was provided on the elastic roller. The material formulation of the surface layer is shown.
100 parts by mass of a polyurethane polyol prepolymer (trade name: Takelac TE5060, manufactured by Mitsui Takeda Chemical Co., Ltd.).
77 parts by mass of isocyanate (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).

MEK (methyl ethyl ketone) was added to the above material, and the mixture was dispersed with a horizontal disperser NVM-03 (trade name, manufactured by IMEX) at a peripheral speed of 7 m / s, a flow rate of 1 cc / _min , and a dispersion temperature of 15 ° C. for 1 hour. After dispersion, MEK was further added to adjust the solid content to 25% by mass (so that the film thickness was 20 μm) as the surface layer raw material liquid. Next, this surface layer raw material was immersed in the outer periphery of the elastic roller at a penetration speed of 100 mm / s in a cylinder having a diameter of 32 circulated at a liquid flow rate of 250 cc / _min and a liquid temperature of 23 ° C., and stopped for 10 seconds. / S at a final speed of 200 mm / s. This was naturally dried for 10 minutes. Subsequently, the raw material of the surface layer was cured by heat treatment at 140 ° C. for 60 minutes, and an elastic roller provided with the surface layer was obtained.

  An elastic roller provided with a surface layer was incorporated in an electrophotographic process cartridge as a developing roller. Table 1 shows the result of examining the density unevenness by outputting the image.

  In Table 1, “h / s” means “h / smax”.

[Example 2]
The following were used as A liquid and B liquid of addition reaction crosslinking type liquid silicone rubber.

  100 parts by mass of a silicone base polymer (weight average molecular weight Mw = 100000, manufactured by Toray Dow Corning) and 3 parts by mass of carbon black (trade name: MA77, manufactured by Mitsubishi Chemical Corporation) were mixed and defoamed with a planetary mixer for 30 minutes. A silicone rubber base material was obtained. A solution A was prepared by adding 0.02 part by mass of an isopropyl alcohol solution of chloroplatinic acid (platinum content: 3% by mass) to 100 parts by mass of the base material. Further, to 100 parts by mass of the silicone base material, 1.5 parts by mass of an organohydrogenpolysiloxane (viscosity 10 mPa · s, SiH content 1% by mass, manufactured by Toray Dow Corning) was added and mixed. It was set as B liquid.

  A silicone rubber mixed liquid obtained by mixing the A liquid and the B liquid was used as the elastic layer material. The viscosity of this material was 10 Pa · s.

A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 3
To 100 parts by mass of each of the liquids A and B of addition reaction cross-linkable liquid silicone rubber (trade name: DY35-1265, manufactured by Toray Dow Corning), 16 parts by mass of carbon black (MA11, manufactured by Mitsubishi Chemical Corporation) was added. added.

  A silicone rubber mixed liquid obtained by mixing the A liquid and the B liquid was used as the elastic layer material. The viscosity of this material was 5000 Pa · s.

A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 4
A ring-shaped member 501 having a shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm. This ring-shaped member has a cylindrical shape that is convexly tapered (taper angle 20 °) from the inner peripheral surface having a thickness of 1.95 mm toward the outer peripheral surface. W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 5
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. This ring-shaped member is tapered (taper angle 20 °) from the lower end of the surface having W1 toward the surface having W2. Further, from the maximum outer diameter portion of the ring-shaped member 501, the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end portion in the traveling direction of the annular slit opening of the coating head. The shortest distance h to h is 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 6
A ring-shaped member 501 having a shape shown in FIG. This ring-shaped member is made of polycarbonate and has a minimum inner diameter r _min of r _min = 6.1 mm, a maximum inner diameter r _max of r _max = 6.2 mm, and a maximum outer diameter D _max of D _max = 12. 0 mm and the minimum outer diameter D _min is D _min = 8.1 mm. W1 = 2.9 mm and W2 = 1.0 mm. This ring-shaped member is tapered from the lower end of the surface having W1 toward the surface having W2 (taper angle 20 °), and is convexly tapered from the outer peripheral surface having a thickness of 0.5 mm toward the inner peripheral surface (taper angle). 75 °).

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 7
A ring-shaped member 501 having a shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. This ring-shaped member is rounded in a convex shape from the lower end of the surface having W1 toward the surface having W2. Further, from the maximum outer diameter portion of the ring-shaped member 501, the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end portion in the traveling direction of the annular slit opening of the coating head. The shortest distance h to h is 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 8
A ring-shaped member 501 having a shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. This ring-shaped member is rounded in a concave shape from the lower end of the surface having W1 toward the surface having W2. Further, from the maximum outer diameter portion of the ring-shaped member 501, the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end portion in the traveling direction of the annular slit opening of the coating head. The shortest distance h to h is 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 9
A ring-shaped member 501 having a shape shown in FIG. This ring-shaped member is made of polycarbonate and has a minimum inner diameter r _min of r _min = 6.1 mm, a maximum inner diameter r _max of r _max = 6.2 mm, and a maximum outer diameter D _max of D _max = 12. 0 mm and the minimum outer diameter D _min is D _min = 8.1 mm. W1 = 2.9 mm and W2 = 1.0 mm. This ring-shaped member is rounded in a concave shape from the lower end of the surface having W1 toward the surface having W2. Further, from the maximum outer diameter portion of the ring-shaped member 501, the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end portion in the traveling direction of the annular slit opening of the coating head. The shortest distance h to h is 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 10
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polyacetal, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 11
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polyethylene terephthalate and has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. . W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 12
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polytetrafluorothien, the inner diameter r is r = 6.1 mm, the maximum outer diameter D _max is D _max = 12.0 mm, and the minimum outer diameter D _min is D _min = 8.1 mm. It is. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 13
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate and has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 6.16 mm. W1 = 2.95 mm and W2 = 0.03 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 14
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate and has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 6.7 mm. W1 = 2.95 mm and W2 = 0.3 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 15
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 7.3 mm. W1 = 2.95 mm and W2 = 0.6 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 16
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate and has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.46 mm. W1 = 2.95 mm and W2 = 1.18 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 17
A ring-shaped member 501 having the shape shown in FIG. The ring-shaped member is made of polycarbonate and has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 9.1 mm. W1 = 2.95 mm and W2 = 1.5 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 18
A ring-shaped member 501 having a shape shown in FIG. 5 (h) was used by being press-fitted into a core metal (shaft core body). This ring-shaped member is made of polycarbonate, the inner diameter r is r = 5.98 mm, and the maximum outer diameter D _max is D _max = 12.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 19
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 0.1 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 20
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.5 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 21
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 2.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

[Example 22]
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 3.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 23
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 5.0 mm.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

Example 24
A ring-shaped member 501 having the shape shown in FIG. This ring-shaped member is made of polycarbonate, has an inner diameter r of r = 6.1 mm, a maximum outer diameter D _max of D _max = 12.0 mm, and a minimum outer diameter D _min of D _min = 8.1 mm. W1 = 2.95 mm and W2 = 1.0 mm. From the maximum outer diameter portion of the ring-shaped member 501 to the point where the vertical line from the maximum outer diameter portion of the ring-shaped member 501 intersects with the horizontal line from the front end in the traveling direction of the annular slit opening of the coating head The shortest distance h is h = 1.0 mm.

  Other than the above, the procedure was the same as in Example 1, but an elastic roller was prepared without a surface layer, and various evaluations were performed. The results are shown in Table 1.

Example 25
An elastic roller was obtained in the same manner as in Example 1. After measuring the amount of splash at the end of this elastic roller, a surface layer was provided in the same manner as in Example 1. An elastic roller provided with a surface layer was incorporated into an electrophotographic process cartridge as a charging roller, and image evaluation was performed (the developing roller used originally with the electrophotographic process cartridge was used).

[Comparative Example 1]
An elastic roller with a surface layer was prepared in the same manner as in Example 1 except that the ring-shaped member 501 was not used, and various evaluations were performed. The results are shown in Table 1.

[Comparative Example 2]
The following were used as A liquid and B liquid of addition reaction crosslinking type liquid silicone rubber.

  100 parts by mass of a silicone base polymer (weight average molecular weight Mw = 100000, manufactured by Toray Dow Corning) and 1 part by mass of carbon black (trade name: MA77, manufactured by Mitsubishi Chemical Corporation) are mixed and defoamed for 30 minutes using a planetary mixer. did. This was a silicone rubber base material. A solution A was prepared by adding 0.02 part by mass of an isopropyl alcohol solution of chloroplatinic acid (platinum content: 3% by mass) to 100 parts by mass of the base material. Further, to 100 parts by mass of the silicone base material, 1.5 parts by mass of an organohydrogenpolysiloxane (viscosity 10 mPa · s, SiH content 1% by mass, manufactured by Toray Dow Corning) was added and mixed. It was set as B liquid.

  A silicone rubber mixed liquid obtained by mixing the A liquid and the B liquid was used as the elastic layer material. The viscosity of this material was 8 Pa · s.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

[Comparative Example 3]
Carbon black (trade name: MA11, manufactured by Mitsubishi Chemical Corporation) 20 is added to 100 parts by mass of each of the liquids A and B of addition reaction crosslinkable liquid silicone rubber (trade name: DY35-1265, manufactured by Toray Dow Corning). Part by weight was added.

  A silicone rubber mixed liquid obtained by mixing the A liquid and the B liquid was used as the elastic layer material. The viscosity of this material was 6520 Pa · s.

  Except for the above, an elastic roller with a surface layer was prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

  In Table 1, PC represents polycarbonate, POM represents polyacetal, PET represents polyethylene terephthalate, PTFE represents polytetrafluoroethylene, and PE represents polyethylene.

It is a schematic diagram which shows the example of the coating head which can be used for this invention. It is a schematic diagram for demonstrating the coating method by a coating head, (a) shows before coating start, (b) shows the state at the time of completion | finish of coating. It is a schematic diagram which shows the example of the coating apparatus which can be used for this invention. It is typical sectional drawing which shows the example of the stop ring which can be used for this invention. (A)-(h) is typical sectional drawing which shows the example of the ring-shaped member which can be used for this invention, respectively. 2A and 2B are cross-sectional views showing the developing roller, in which FIG. 1A is a cross-sectional view in the longitudinal direction of the developing roller, and FIG. 2A and 2B are cross-sectional views illustrating a charging roller manufactured according to the present invention , in which FIG. 1A is a cross-sectional view in the longitudinal direction of the charging roller, and FIG. It is a typical sectional view for explaining an example of an image forming device. It is the schematic of the apparatus which measures the resistance of an elastic roller. It is typical sectional drawing of the step which mounted | wore the coating ring with the stop ring, the ring-shaped member, and the axial core body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging apparatus 3 Image exposure apparatus (writing beam)
4 Developing device 5 Cleaning device 6 Image transfer device 7 Transfer material (paper)
8a to d Image forming unit 9 One-component toner 10 Developer container 11 Toner supply roller 12 Development blade 13 Transfer conveyor belt 14 Drive roller 15 Tension roller 16 Follow roller 17 Adsorption roller 18 Supply roller 19 Peeling device 20 Fixing device 21 Adsorption roller Bias power source 22 Image transfer device bias power source 60 Developing roller 61 Shaft core (developing roller)
62 Elastic layer (developing roller)
63 Surface layer (developing roller)
70 Charging roller 71 Shaft core (charging roller)
72 Elastic layer (charging roller)
73 Surface layer (charging roller)
92 Metal drum 101 First annular member 102 Second annular member 103 Annular slit 104 Elastic layer material discharge port 105 Annular member holding member 106 Liquid distribution chamber 107 Throttle step portion 301 Base 302 Column 303 Ball screw 304 LM guide 305 Servo motor 306 Pulley 307 Bracket 308 Coating head 309 Shaft core lower holding shaft 310 Shaft core upper holding shaft 311 Supply port 312 Pipe 313 Material supply valve 314 Linear guide 401 Ring-shaped member disposed forward in the traveling direction from the annular slit of the coating head ( Stop ring)
501 Ring-shaped member arranged behind the annular slit of the coating head in the traveling direction

Claims (6)

A coating head having an annular slit opened inside is moved in the direction of gravity relative to the shaft core body, and an uncured elastic layer material is discharged from the annular slit onto the outer peripheral surface of the shaft core. An elastic layer having an elastic layer on the outer peripheral surface of the shaft core, and a curing step of curing the uncured elastic material applied on the outer peripheral surface of the shaft core after the coating step In the method for manufacturing a roller,
Before the coating step, it has a ring-shaped member arrangement step of arranging a ring-shaped member,
In the ring-shaped member arrangement step, the maximum outer diameter portion of the ring-shaped member is positioned rearward in the coating head moving direction from the end on the coating head moving direction rear side of the opening of the annular slit,
In the coating step, the coating head discharges and coats an uncured elastic layer material on the outer peripheral surface of the shaft core so as to contact the ring-shaped member,
In the curing step, the uncured elastic layer material is cured without removing the ring-shaped member to form an elastic layer,
And the manufacturing method of the elastic roller whose viscosity in 25 degreeC of this uncured elastic layer material is 10 Pa.s or more and 5000 Pa.s or less.   The method for producing an elastic roller according to claim 1, wherein the ring-shaped member has a melting point of 160 ° C. or higher.   The elastic roller manufacturing method according to claim 1, wherein a material of the ring-shaped member is a synthetic resin. When the maximum outer diameter of the ring-shaped member is D _max (mm), the minimum outer diameter is D _min (mm), and the inner diameter is r (mm), W1 (mm) represented by Expression 1 and Expression 2 The method for manufacturing an elastic roller according to any one of claims 1 to 3, wherein W2 (mm) represented by:

The maximum opening width of the annular slit is s _max (mm), and from the maximum outer diameter portion of the ring-shaped member, the vertical line from the maximum outer diameter portion is on the front side in the coating head moving direction of the annular slit opening. 5. The method for producing an elastic roller according to claim 1, wherein s _max and h satisfy Expression 4 when a shortest distance from the end to a point intersecting the horizontal line is h (mm).

  The method for producing an elastic roller according to any one of claims 1 to 5, wherein the elastic layer is made of silicone rubber.

Images