JP2005103447A - Method and apparatus for coating rubber roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus capable of substituting an overflow coater which inevitably becomes larger in size, capable of accomplishing simplification in structure and reduction in size, capable of coping with a demand for reduction in the amount of an organic solvent used, capable of simplification of a complicated step, i.e.g, twice coating after inversion necessary to obtain a uniform film thickness in coating of a rubber roller by a vertical dip method, into single-time coating, and capable of forming a uniform coating film. <P>SOLUTION: The rubber roller coating method is one comprising vertically holding the end of the rubber roller from the overhead, immersing it in a coating fluid in a coating tank, and lifting it to perform surface coating, wherein coating is accomplished by using a means that keeps the level of the coating fluid constant by inhibiting the rise in the level of the coating fluid upon immersion and the overflow of the fluid from the top margin of the coating tank, and the rubber roller can be lifted without lowering the level of the coating liquid. The coater used therein is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coating method and a coating apparatus such as a charging roller and a developing roller used for image formation of an electrophotographic apparatus such as a laser beam printer and a facsimile as a rubber roller having a surface layer.

  There is a vertical dipping method as one of the methods of coating the surface of the rubber roller, and the film thickness of the surface layer is controlled by controlling the pulling speed of the rubber roller from the coating solution and the viscosity of the coating solution. (For example, Patent Document 1).

  In this case, it is desirable that the coating liquid surface be near the upper end of the coating tank and be constant. The reason is that when the rubber roller is pulled up without taking any means, the liquid level is lowered by the volume obtained by adding the volume of the rubber roller out of the liquid and the volume attached to the rubber roller. For coating liquids in which the paint is dispersed or dissolved in an organic solvent, the space filled with the coating liquid evaporation component above the liquid level in the coating tank changes, so that the coating liquid is covered. Since the evaporation time of the coating solution solvent from the surface changes in the vertical direction of the rubber roller, it becomes easier to sag the coating solution coated surface in the space for a long time above, resulting in the uniformity of the coating film. Absent.

  Another reason is that a dry portion of the paint is generated inside the coating tank due to a drop in the liquid level. In the coating liquid dispersed or dissolved in the organic solvent, the phenomenon is remarkable, and therefore the homogeneity of the coating liquid is impaired, and as a result, the uniformity of the coating film cannot be obtained.

  Therefore, it is desirable that the coating liquid surface is near the upper end of the coating tank and is constant regardless of whether or not the rubber roller is immersed in the coating tank.

  Further, if the rubber roller is immersed from this state, the coating liquid overflows from the coating tank, so that the liquid level cannot be kept constant in the next pulling.

  Therefore, in the above prior art coating method, in order to keep the coating liquid level constant, the paint is always overflowed from the coating tank by a circulation pump or the like, and the coating liquid is circulated in the coating apparatus for coating. Is common. In this case, if the flow velocity of the overflow is high or the distance between the coating tank wall and the coating surface of the rubber roller is close, the coating liquid coating surface is easily affected by overflow, and the coating film has a uniform stability. There was a problem that it was difficult to get.

  In this method, it is inevitable that the coating apparatus is complicated and large, such as by adding a circulation pump and an auxiliary tank that receives the overflowed coating liquid, and the amount of coating liquid in the coating apparatus increases accordingly. In the case of a coating liquid that is dispersed or dissolved in an organic solvent, it is difficult to control the viscosity of the coating liquid. It has been desired to develop a coating method and a coating apparatus for obtaining a good and uniform coating film while accommodating the amount.

In the vertical dipping method, the coating liquid adhering to the peripheral surface of the rubber roller hangs down along the surface of the rubber roller due to gravity, and the upper film thickness becomes thinner than the lower film thickness. Therefore, in order to obtain a uniform film thickness, the complexity of the process in which the rubber roller has to be turned upside down and the coating process has to be performed again has been a problem. This is because there was no means to reduce the speed continuously during a single coating, although it was known that the film thickness can be increased by increasing the pulling speed and can be decreased by decreasing the speed. is there.
Japanese Patent Application No. 2001-62153

  Accordingly, an object of the present invention is to realize a coating that can be simplified and miniaturized in place of the overflow type coating apparatus that cannot avoid the complicated and large size of the prior art and can meet the demand for reducing the amount of organic solvent used. It is to provide a construction method and a coating apparatus.

  Moreover, the subject of this invention is simplifying the complicated process of up-and-down inversion 2 times performed in order to obtain a uniform film thickness to 1 time in the coating of the rubber roller by the vertical dipping method.

  Another object of the present invention is to provide a coating method and a coating apparatus that can form a uniform coating film and that is particularly easy to implement in the coating of a rubber roller by the vertical dipping method. .

The present invention is a rubber roller coating method in which an end of a rubber roller is vertically gripped from above, immersed in a coating liquid in a coating tank, and then surface coating is performed by pulling up.
A means for keeping the height of the coating liquid level constant;
The coating liquid level rises during dipping, exceeds the upper end of the coating tank, the coating liquid does not overflow, and the coating liquid level does not decrease during pulling up to complete the coating. A rubber roller coating method characterized by:

In addition, the present invention provides a coating tank and a rubber roller coating that performs surface coating by means of vertically pulling the end of the rubber roller from above and immersing it in the coating solution in the coating tank. In the device
As a means for keeping the level of the coating liquid level constant, it has a replenisher tank connected to the coating tank, and the replenisher tank is a lance cylinder.
The liquid level of the coating liquid rises during the immersion, the upper end of the coating tank is exceeded, the coating liquid does not overflow, and the liquid level of the coating liquid does not decrease during the lifting, A rubber roller coating device characterized in that the coating is completed.

  According to the present invention, a coating method and a coating apparatus that can accommodate a minimum amount of liquid, can form a good and uniform coating film, and are particularly easy to implement can be realized.

  The present invention will be described with reference to FIGS.

  1 and 2 show a schematic arrangement of each step and apparatus of the coating method of the present invention.

  As shown in the figure, the object to be coated is a rubber roller 100, and silicone rubber is bonded so that both ends of an iron core bar come out.

  In the present invention, a uniform surface coating film is formed on an elastic layer such as the silicone rubber layer.

  As a material for the coating film in the present invention, a urethane material dissolved in an organic solvent is used.

  The jig 101 that holds one end of the rubber roller is a means for pulling up or immersing the rubber roller in the coating tank 112. In this embodiment, the jig 101 has a structure that can hold four at the same time. The jig is connected to a servo motor 102 as a driving source so as to convert a rotary motion into a reciprocating motion via a ball screw 103. From the rationality of arrangement, the servo motor 102 and the ball screw are connected by a timing belt.

  The lance cylinder, which is a means for keeping the coating liquid level constant, is composed of a cinder 104, a piston 105, and a seal 106 for preventing the coating liquid from leaking from the sliding portion, and the piston 105 is a driving source thereof. The servo motor 107 is connected via a ball screw 108 so as to convert the rotational motion into a reciprocating motion. Also in this case, the servo motor 107 and the ball screw 108 are connected by a timing belt because of the rational arrangement.

  In order to keep the coating surface constant, it is necessary to replenish the coating tank with the amount reduced by applying it to the rubber roller, and 109 is used as a replenisher tank for storing the replenishing coating liquid. It is attached in the device. In the replenishment method, a sensor capable of detecting the liquid level is provided in the upper space of the coating tank, the electromagnetic valve 110 is opened and closed, and the gravity roller is used so that the rubber roller is not immersed in the coating tank. The liquid level is ensured. The two servo motors are set so that the speed can be changed continuously at a minute interval in each control means. Each control means is built in one controller 111, and each controller is set to interpolate its position and operate in conjunction.

  The coating process will be described with reference to FIGS.

  FIG. 1 shows a state before coating. The rubber roller 100 is gripped by a jig 101, and the jig is stationary at a position where a dipping stroke can be secured. The piston 105 of the lance cylinder is stationary in the vicinity of the lower end of the cylinder 104 that can secure a stroke sufficient to suck up the capacity overflowed by the immersion of the rubber roller, and can secure a capacity that can compensate for the amount of application to the rubber roller. The liquid level in the coating tank is stationary at a position that is optimal for coating near the upper limit of the coating tank and does not overflow by the above-described means. Next, the rubber roller 100 is immersed in the coating tank over the entire length of the coating area by the lowering operation of the jig 102. At the same time, the piston 105 of the lance cylinder moves upward in conjunction with the jig 101 to accommodate the overflow in the cylinder 104. This state is shown in FIG.

  Next, when the rubber roller was pulled up from the coating tank, the jig 101 and the piston 105 of the lance cylinder were operated in an interlocked manner opposite to that during immersion, so that the position of the coating liquid surface could be made constant. In other words, this is because the lowering of the liquid level due to the pull-up is compensated by the lowering operation of the lance cylinder. At this time, in the present embodiment, the rubber roller is pulled up by dividing the entire length of the rubber roller coating area by 300, setting the speed for each, and continuously decelerating by applying the paint on the rubber roller. It was possible to prevent the phenomenon that the lower part was thin and the bottom part was thick, and it was possible to achieve the film thickness uniformity of the two-time coating.

The result is the amount of liquid contained.
Thickness uniformity with respect to the target value of 10 μm Thickness difference 3 μm (upside-down inversion twice coating) The present invention 3 μm (one-time coating)
Met.

It is explanatory drawing which shows the process in the coating apparatus and coating method of this invention, and shows the state at the time of completion of coating before coating. It is explanatory drawing which shows the process in the coating apparatus and coating method of this invention, and the state which the rubber roller immersed in the coating tank is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Rubber roller 101 Jig 102 Servo motor 103 Ball screw 104 Cylinder 105 Piston 106 Seal 107 Servo motor 108 Ball screw 109 Replenishment liquid tank 110 Electromagnetic valve 111 Controller 112 Coating tank

Claims (4)

In the rubber roller coating method in which the end of the rubber roller is vertically gripped from above, immersed in the coating liquid in the coating tank, and then surface-coated by pulling up,
A means for keeping the height of the coating liquid level constant;
The coating liquid level rises during dipping, exceeds the upper end of the coating tank, the coating liquid does not overflow, and the coating liquid level does not decrease during pulling up to complete the coating. A rubber roller coating method characterized by: In the coating device of the rubber roller, which grips the coating tank and the end of the rubber roller vertically from above, immerses in the coating liquid in the coating tank, and performs surface coating by means of lifting,
As a means for keeping the level of the coating liquid level constant, it has a replenisher tank connected to the coating tank, and the replenisher tank is a lance cylinder,
The liquid level of the coating liquid rises during the immersion, the upper end of the coating tank is exceeded, the coating liquid does not overflow, and the liquid level of the coating liquid does not decrease during the lifting, A rubber roller coating device characterized by completing the coating.   The speed increasing / decreasing means for controlling the speed of the rubber roller and the speed increasing / decreasing means for controlling the vertical operating speed of the piston of the lance cylinder are speed increasing / decreasing means for continuously controlling the speed. 2. A rubber roller coating apparatus according to 2. 4. The rubber roller coating apparatus according to claim 3, further comprising means for synchronously operating the two speed increasing / decreasing means.