JP2005215297A - Method for manufacturing electrically conductive roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrically conductive roller by which unevenness in the thickness of a layer constituting the electrically conductive roller can be diminished by reducing the height of a leaving mark formed when an application roll leaves an electrically conductive roller after coating by roll coater coating. <P>SOLUTION: After completing the coating, the electrically conductive roller as well as the application roll is moved in a direction inclined at 45-90° to a direction toward a radial outside of the application roll, whereby the electrically conductive roller is made to leave the application roll. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a conductive roller, such as a charging roller, a developing roller, and the like, in which a surface layer of a conductive roller having a surface layer on the radially outer side of a conductive base layer is formed by roll coater coating. Relates to what forms the layer.

  Conductive rollers such as a charging roller that is mounted on an electrophotographic apparatus such as a copying machine or a printer, an electrostatic recording apparatus, etc., and charges the surface of the photosensitive drum, and a developing roller that transfers toner onto the surface of the photosensitive drum. A thin film surface layer which is the outermost layer is provided on the radially outer side of the columnar base layer having a shaft.

  Conventionally, as a method of forming this surface layer, a method of forming a coating film by roll coater coating and using this as a surface layer is proposed in addition to a method by dipping coating or spray coating (see, for example, Patent Document 1).

  This roll coater coating method uses the application roll that holds the paint supplied from the paint pan on the circumference, and makes the entire surface in the axial direction of the conductive roller that is the object to be coated in contact with each other. This is a method in which the paint is applied simultaneously, and it is easy to apply one by one continuously, so that it has a feature that the productivity is higher than other methods.

  However, in this roll coater coating, prior to coating, the conductive roller is translated toward the center on the radius until it comes into contact with the peripheral surface of the application roll. The application roll is moved away from the application roll by translation, but there is a problem that the coating film part of the conductive roller that finally comes off from the application roll becomes a thick film and remains as a leaving trace extending in the roller axial direction. .

  FIG. 1 is a schematic view of the conductive roller as viewed from the axial direction when it is detached from the application roll. When the coating is completed, as shown in FIG. The coating film P1 is held, and a coating film P3 is formed on the periphery of the conductive roller R. These coating films P2 and P3 are integrated at the abutting portion C. When the conductive roller R is detached from the roll 2, this is performed by translating the conductive roller in the direction of the arrow Pr shown in the drawing, that is, in the direction toward the radially outer side.

  FIG. 1 (b) shows the conductive roller R slightly away from the application roll 2 with respect to the position under the coating. At this time, the contact portion C between the coating films P3 and P2 is shown. Is stretched radially outward due to surface tension, but is still in a connected state.

When the conductive roller R is further away from the application roll 2, as shown in FIG. 1 (c), the contact portion C is extended and becomes thinner, and when the surface tension of the paint reaches the limit, the coating films P2 and P3 However, at this time, the separation portion C1 of the contact portion C becomes a thick film on the conductive roller R and remains as a separation trace extending in the roller axial direction.
JP 2001-134114 A

  The present invention has been made in view of such problems, and suppresses the height of the separation trace formed when the conductive roller is applied by roll coater coating and then released from the application roll. Thus, it is an object of the present invention to provide a method for manufacturing a conductive roller that can reduce the variation in the thickness of the constituent layers constituting the conductive roller.

<1> is a conductive material that forms a layer constituting the conductive roller by coating the conductive roller with a paint on the periphery of the application roll arranged in parallel with the conductive roller and the peripheral surfaces in contact with each other. In the method for manufacturing a roller,
This is a method for manufacturing a conductive roller in which the conductive roller is translated from the application roll in a direction inclined by 45 to 90 degrees with respect to the direction toward the radially outer side of the application roll after the coating is completed.

  <2> in <1>, the conductive roller is applied to the application roller while rotating the conductive roller in the same rotation direction as the application roller against the driving force caused by the contact between the peripheral surfaces of the application roller. It is a manufacturing method of the electroconductive roller of Claim 1 made to detach | leave from a roll.

  <3> is the method for producing a conductive roller according to claim 1 or 2, wherein the translational relative speed when the conductive roller is detached from the application roll in <1> or <2> is 1 to 10 mm / s. It is.

  According to the invention of <1>, as will be described in detail later, the conductive roller is translated and detached from the application roll in a direction inclined by 45 to 90 degrees with respect to the direction toward the radially outer side of the application roll. , It is possible to widen the separation surface at the time of separation, and to suppress the height of the separation trace by that amount.

  According to the invention of <2>, the conductive roller is rotated in the same rotation direction as the application roller against the driving force caused by the contact between the peripheral surfaces of the application roller and the application roller. Therefore, the height of the separation trace can be further suppressed by expanding the separation trace portions in the tangential direction.

According to the invention <3>, since the translational relative speed when the conductive roller is detached from the application roll is 1 to 10 mm / s, the height of the separation mark can be further reduced.
When this relative speed is less than 1 mm / s, the separation trace becomes small, but it is not preferable because the separation time of the conductive roller becomes long and the productivity is lowered, and when this exceeds 10 mm / s, there is no separation trace. It becomes large and is not preferable.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a cross-sectional view showing the conductive roller R formed by the manufacturing method of the present embodiment. The conductive roller R includes a shaft S, a base layer L1 disposed around the shaft S, and a base layer L1. And a surface layer L2 forming the roller peripheral surface. As such a conductive roller R, a charging roller that is mounted on an electrophotographic apparatus such as a copying machine or a printer, an electrostatic recording apparatus, or the like and charges the surface of the photosensitive drum, or a developer that transfers toner onto the surface of the photosensitive drum. There are rollers or the like, and in these rollers, the shaft S is a portion that is supported by an electrophotographic apparatus such as a printer, and is made of metal or plastic.

  For example, in the case of a charging roller, the base layer L1 is composed of two or more layers of an elastic layer L1a made of sponge rubber or the like and a resistance adjusting layer L1b provided on the outer periphery thereof to adjust the electric resistance between the surface layer and the surface layer. L2 is, for example, one or more of urethane-modified acrylic resin, polyurethane resin, acrylic resin, polyamide resin, fluororesin, etc. mixed with various electronic conductive agents, various ionic conductive agents, and conductive materials such as carbon. Thus, those imparted with conductivity are used.

  The thickness of the surface layer L2 is usually 1 to 30 mμ, and the width of the variation is formed with high accuracy so that it becomes ± 2 mμ or less when the thickness of the surface layer L2 is 20 mμ, for example.

  FIG. 3 is a cross-sectional view schematically showing the roll coater type conductive roller coating apparatus 1 for forming the surface layer L2. The roll coater type conductive roller coating apparatus 1 is arranged in parallel with the conductive roller R and is in contact with the peripheral surface of the conductive roller R. The application roll 2 that rotates and paints the paint on the periphery on the conductive roller, the paint pan 3 that contains this paint, the paint P0 in the paint pan 3 is brought into contact with the peripheral surface and the application roll 2 A pick-up roll 4 that rotates by bringing the surfaces into contact with each other and pumps the paint P0 from the paint pan 3 and supplies it to the application roll 2 is provided.

  In this apparatus 1, the paint P 0 accommodated in the paint pan 3 adheres to the surface of the rotating pickup roll 4 and is pumped up. Part of the paint P1 pumped up on the pickup roll 4 is supplied to the application roll 2 that rotates in contact with the pickup roll 4, and the paint P2 supplied onto the application roll 2 is similarly conductive. The paint P3 painted on the peripheral surface of the roller R and coated on the base layer L1 of the conductive roller R becomes the surface layer L2 after drying.

  4 and 5 are schematic views of the conductive roller as viewed from the axial direction, and a method for forming a surface layer on the conductive roller R will be described with reference to these drawings. First, as shown in FIG. 4 (a), the conductive roller R is translated to a predetermined position along the tangential direction Pt of the rotating application roll 2 while holding the paint on the peripheral surfaces, and the peripheral surfaces are brought into contact with each other. Make contact. At this time, the shaft S of the conductive roller R is connected to a roller drive shaft that drives the roller R via a clutch in a disconnected state. The drive force of the roller drive shaft is reduced by the action of the clutch. Since it is not transmitted to R, as shown in FIG. 4B, the conductive roller R starts to rotate by being driven by the contact between the peripheral surfaces of the rotating application roll 2.

  Thereafter, the clutch is connected and the driving of the conductive roller R is started by the driving force of the roller driving shaft. The driving direction of the conductive roller R is the same as that of the application roller 2 as shown in FIG. It is set so as to rotate in the same direction as the application roller 2 against the driving force caused by the contact between the peripheral surfaces. In other words, at this time, the conductive roller R and the application roller 2 rotate so that their peripheral surfaces are displaced in directions opposite to each other on their contact surfaces. Then, by performing this rotation a predetermined number of times, a predetermined film thickness is formed and the coating is completed. At this time, the coating film P1 is held on the circumference of the application roll 2, and the circumference of the conductive roller R is also increased. Is formed with a coating film P3, and these coating films P2 and P3 are in a state of being integrated by a contact portion C having a contact width of W.

  Next, the conductive roller R is continuously driven by the driving force of the roller drive shaft, and the conductive roller R is inclined by 90 degrees with respect to the tangential direction Pt1, that is, the direction toward the radially outer side of the application roll 2. And the conductive roller R is separated from the application roll 2. FIG. 5B shows a state in which the conductive roller R is slightly displaced in translation. In this state, the contact portion C is extended in the tangential direction.

  When the conductive roller is further translated and moved away from the application roll 2, the contact portion C is further extended in the tangential direction and the surface tension of the paint reaches the limit. As shown in FIG. P2 and P3 are separated from each other. At this time, the separation portion C1 of the contact portion C becomes a thick film and the trace of separation extending in the roller axis direction remains slightly on the conductive roller R. Since the film is thick by substantially the same thickness over the entire width of the contact width W of C, the height of the separation trace can be reduced, and variations in the coating film over the entire circumference of the conductive roller can be suppressed.

  Then, when the conductive roller R is detached from the application roll 2, the application roll 2 is held in a rotated state, thereby averaging the separation marks and the thickness of the portion including the periphery when the application roller 2 is rotated. And variations in the coating film can be further suppressed.

  Here, the translation speed at the time of separating these is preferably 1 to 10 mm / s, and the direction in which the conductive roller R is detached from the application roll 2 includes the tangential direction as well as the application roll. The direction may be any direction that is inclined by 45 to 90 degrees with respect to the direction toward the outer side in the radial direction.

  In the method for manufacturing the conductive roller R described in the present embodiment, the direction of separation when the conductive roller R is detached from the application roll 2 is set to a plurality of levels, and the conductive roller is separated in these directions. Each conductive roller was prototyped, and the variation in the film thickness of the surface layer of these rollers was measured. In addition, when the conductive roller is removed during its rotation, or after the rotation of the conductive roller is stopped and then released, the conductive roller is also manufactured with different levels and the level of the separation speed. In the same manner, the variation in the film thickness of the surface layer of the conductive roller was measured and compared. The results are shown in Table 1.

  Here, the thickness of the surface layer of the conductive roller R is measured by cutting the conductive roller R along a step surface perpendicular to the length direction, then taking an electron micrograph of the cross section, and measuring the dimensions on the image. went. Also. Regarding the film thickness variation, for each of the five conductive rollers R separated from the application roller 2 under the same measurement conditions, the difference between the maximum film thickness value and the minimum film thickness within one roller is ΔT. The average value of ΔT was taken, and this average value was defined as film thickness variation.

  Table 2 shows the main specifications of the prototype conductive roller, the paint used in the trial production, and the roll coater type conductive roller coating apparatus.

  As described above, as shown in Table 1, it can be seen that the conductive rollers of Examples 1 to 13 can reduce variations in the film thickness of the surface layer.

In the manufacturing method of the conventional electroconductive roller, it is the schematic diagram which looked at the electroconductive roller at the time of detachment | leave from an application roll from the axial direction. It is sectional drawing which shows the conductive roller formed by the manufacturing method of embodiment which concerns on this invention. It is sectional drawing which shows typically the roll coater type electroconductive roller coating apparatus used for this embodiment. It is the schematic diagram which looked at the electroconductive roller at the time of detachment | leave from an application roll from the axial direction. It is a schematic diagram explaining the process following FIG.

Explanation of symbols

1 Roll Coater Type Conductive Roller Coating Equipment 2 Application Roll 3 Paint Pan 4 Pickup Roll
L1 Base layer L1a Elastic layer L1b Resistance adjustment layer L2 Surface layer P0, P1, P2, P3 Paint R Conductive roller S Shaft

Claims (3)

In a method of manufacturing a conductive roller, a coating roller is coated with a coating on the periphery of an application roll arranged in parallel with the conductive roller and the peripheral surfaces in contact with each other to form a layer constituting the conductive roller. ,
A method of manufacturing a conductive roller, in which, after the coating is completed, the conductive roller is translated from the application roll in a direction inclined by 45 to 90 degrees with respect to the direction toward the radially outer side of the application roll.   The conductive roller is separated from the application roll while the conductive roller is rotated in the same rotational direction as the application roller against a driving force caused by contact between the peripheral surfaces of the application roller and the application roller. Manufacturing method of conductive roller.   The method for producing a conductive roller according to claim 1 or 2, wherein a translational relative speed when the conductive roller is separated from the application roll is 1 to 10 mm / s.

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