JP2796129B2 - Rectifier for coating liquid used in drum coating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention is used for manufacturing a photosensitive drum used in, for example, an electrophotographic copying machine, and a drum coating for coating a photosensitive material on an outer peripheral surface of the drum. The present invention relates to a rectifier for a coating solution used in the method.

(Prior Art) For example, a photosensitive drum used in an electrophotographic copying machine is formed by applying a photosensitive substance to a drum outer peripheral surface using a conductive material, such as an alumite pipe. In such a photosensitive drum, it is important to apply a photosensitive substance uniformly. As a method of manufacturing a photosensitive drum for applying a photosensitive substance to the outer peripheral surface of a drum, a drum is immersed in a coating liquid of a photosensitive substance, and the drum is pulled up from the application liquid in the axial direction thereof, and the drum is exposed to the outer peripheral surface. A so-called immersion method of applying a coating liquid is generally used.

A volatile organic solvent such as tetrahydrofuran or the like is used as a solvent in the coating liquid used for manufacturing the photosensitive drum, and the organic solvent is constantly evaporated from the coating liquid surface. Therefore, when the photosensitive drum is manufactured by the immersion method, the coating liquid in the tank containing the coating liquid is always filled with the vapor of the solvent. The drum pulled up from the coating liquid passes through this solvent vapor layer and is discharged out of the tank. On the other hand, when the drum is pulled up from the coating liquid, the coating liquid level is lowered corresponding to the volume of the drum discharged from the coating liquid. For this reason, the volume of the space above the coating liquid surface in the tank increases sequentially, and the concentration of the solvent vapor in this space depends on the volume of the drum pulled up from the coating liquid.
Decrease sequentially. Therefore, when the ram is pulled up from the coating solution in the axial direction, the upper part of the drum, which is first discharged from the coating solution, gradually lowers in a narrow space on the surface of the coating solution from the atmosphere of the highly concentrated solvent vapor. Exposure to an atmosphere of concentrated solvent vapor. Finally, the lower part of the drum discharged from the coating liquid is merely exposed to the atmosphere of the low concentration solvent vapor in the wide space on the coating liquid surface. Due to the constant evaporation of the solvent vapor, the concentration of the coating liquid also varies constantly, and the upper and lower parts are significantly different. For this reason, the drying speed of the applied coating liquid varies depending on the axial position of the outer peripheral surface of the drum, and the coating liquid applied to the outer peripheral surface of the drum is not uniform. In addition to stripe-shaped coating unevenness), circumferential unevenness (film thickness becomes uneven in the circumferential direction), haze (black spots), etc., thinning of the coating liquid at the lower end, vertical streaks, etc. Coating unevenness may occur. If such coating unevenness occurs, the photosensitive layer of the manufactured photosensitive drum does not have a uniform thickness, the charging characteristics become non-uniform, and image unevenness occurs. Further, white spots due to pinholes and background stains due to toner adhesion also occur, so that clear electrophotographs cannot be supplied after all.

For this reason, in the immersion method, the tank is filled with the coating liquid, and when the drum is immersed in the coating liquid, the coating liquid is continuously supplied from the lower part of the tank to overflow the coating liquid from the upper surface of the tank. In addition, a method of preventing the fluctuation of the coating liquid surface by preventing the fluctuation of the concentration distribution in the coating liquid due to evaporation of the solvent vapor and uniformly applying the coating liquid on the outer peripheral surface of the drum is also known. I have.

(Problems to be Solved by the Invention) As described above, in the method in which the drum is dipped in the coating liquid and the drum is pulled up from the coating liquid while the coating liquid overflows from the tank, the coating liquid in the tank is exposed to the outer peripheral surface of the drum. Flow along the axis, the coating liquid applied to the outer peripheral surface of the drum pulled up from the coating liquid becomes non-uniform, and it is impossible to completely prevent the above-described coating unevenness.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a rectifying device for a coating liquid used in a drum coating method capable of uniformly applying a coating liquid without causing a coating unevenness on an outer peripheral surface of a drum. Is to do.

(Means for Solving the Problems) A rectifier for a coating liquid used in the drum coating method of the present invention is provided by vertically dipping a drum in a coating liquid contained in a tank and supplying the coating liquid to the tank. A coating liquid rectifier used in a drum coating method for applying the coating liquid to the outer peripheral surface of the drum by pulling up the drum from the coating liquid while overflowing the coating liquid from the tank; And a plurality of straight lines through which the coating liquid supplied from below is passed in a predetermined inclined state toward the tank inner surface without entering the drum immersed in the coating liquid above the coating liquid. It is characterized by having a guide hole in the shape of a circle, thereby achieving the above object.

Further, the rectifier for a coating solution used in the drum coating method of the present invention is a device for immersing a drum vertically in a coating solution accommodated in a tank, supplying the coating solution to the tank, and removing the coating solution from the tank. By raising the drum from the coating liquid while overflowing, it is a rectifier of the coating liquid used in the drum coating method for coating the coating liquid on the outer peripheral surface of the drum, is disposed in the lower portion of the tank, A plurality of linear guide holes penetrating vertically in a predetermined inclined state so that the coating liquid supplied from below flows upward, and an extension of the axis of each guide hole is the inner surface of the tank. Intersect with the tangential direction at an angle θ ₁ of 45 degrees or less, and incline at an angle θ ₂ of 45 degrees or less with respect to the horizontal direction, and a tangent (tan θ ₂ ) to the inclination angle θ ₂ of each guide hole The axis is translated horizontally. It is characterized small (tanθ _{2 <y} / x) than the ratio of the radius x vertical distance y and the drum inner peripheral surface from the point of intersection with the drum axis to the drum lower end when the above by its Objective is achieved.

(Example) Hereinafter, the present invention will be described with reference to examples.

FIG. 1 and FIG. 2 are schematic views of an embodiment of a drum coating method. The drum 10 made of an alumite tube is immersed in a coating solution contained in a cylindrical tank 21. The drum 10 is held vertically by a suitable chucking device (not shown), and the drum 10 is moved up and down by moving the chucking device up and down.

The tank 21 has an open top surface, and a supply liquid supply pipe 31 is provided on a side surface of a lower end portion thereof. The supply pipe
31 is connected to the tank 21 in a state of being inclined with respect to the radial direction of the tank 21 so that the supplied coating liquid flows upward from below along the inner peripheral surface of the lower end of the tank 21. The part is inclined so as to be upward. Therefore, the tank
The application liquid is supplied to 21 from the lower side of the side via the supply pipe 31.

The drum 10 is held in a substantially vertical shape, and is immersed substantially entirely in a coating solution contained in a tank 21. Then, the coating liquid is supplied from the supply pipe 31 into the tank 21, and the drum 10 is pulled up from the coating liquid in the tank 21 in a state where the coating liquid overflows from the tank 21. At this time, the tank
The coating liquid supplied to the inside of the tank 21 flows along the inner peripheral surface of the lower end portion of the tank 21, is swirled in the coating liquid below the drum 10 in the tank 21, and flows upward from below.
Thus, the coating liquid in the tank 21 flows upward from below as a swirling flow along the outer peripheral surface of the drum 10 immersed in the coating liquid, and overflows from the upper surface of the tank 21. As described above, the coating liquid is swirled along the outer peripheral surface of the drum 10 and flows upward from below, and in a state where the coating liquid overflows from the upper surface of the tank 21, the drum 10 is pulled up from the coating liquid. Thus, the coating liquid is uniformly applied to the outer peripheral surface of the drum 10 without causing coating unevenness.

FIG. 3 is a tank showing another embodiment of the drum coating method.
FIG. 22 is a sectional view. The tank 22 has a truncated conical shape whose diameter is gradually reduced as the lower portion 22a is located on the lower side. A vertical application liquid supply pipe 32 is connected to the lower end of the lower portion 22a. When the drum 10 is pulled up from the tank 22, the application liquid is supplied into the tank 22 by the supply pipe 32. A rectifier 40 for rectifying the application liquid supplied from the supply pipe 32 in a swirl shape is provided in the lower portion of the cylindrical portion and the frustoconical lower portion 22a of the tank 22. Rectifier 40
As shown in FIG. 4, a horizontal regulating plate 41 facing the coating liquid discharge port of the supply pipe 32 vertically disposed on the lower surface of the tank 22 and a vertically attached lower surface of the regulating plate are provided. And a short cylindrical guide portion 42 provided.

The regulating plate 41 is a drum immersed in the coating solution in the tank 22.
The drum 10 has a rectangular shape large enough to cover the lower end surface of the drum 10, and is positioned slightly below the lower end of the drum 10 in a state where the drum 10 is almost entirely immersed in the coating liquid in the tank 22. For example, four large-diameter through-holes 42a are formed on the peripheral surface of the short cylindrical guide portion 42 at an interval equal to the peri-buccal effect, and each large-diameter through-hole 42a is provided between the large-diameter through-holes 42a. Small-diameter through-holes 42b each having a diameter slightly smaller than the hole 42a are formed.

When the coating liquid was allowed to flow from the supply pipe 32 into the tank 22 in a state where the drum 10 was immersed in the coating liquid in the tank 22 in which the rectifier 40 was disposed, the liquid flowed into the tank 22. The application liquid flows into the guide portion 42 of the rectifier 40 and collides with the regulating plate 41. The coating liquid that has collided with the regulating plate 41 is radiated from each of the large-diameter through holes 42a and the small-diameter
The fluid flows out between the inner peripheral surface of the tank 22 and the swirling flow along the inner peripheral surface of the tank 22 and flows upward from below. Then, by pulling up the drum 10 from the coating liquid in the tank 22 while overflowing the coating liquid from the tank 22,
The coating liquid is uniformly applied to the outer peripheral surface of the drum 10 without causing coating unevenness.

As shown in FIG. 1 and FIG. 2, when the coating liquid is supplied from the side of the tank 21, the coating liquid of the tank 21 is required to make the coating liquid a swirling flow along the outer peripheral surface of the drum 10. A space elongated in the axial direction is required below the drum 10 immersed in the liquid, but as shown in FIG. When the application liquid is supplied and the rectifier 40 causes the application liquid supplied into the tank 22 to be swirled, the coating liquid is surely swirled by the rectifier 40. It is sufficient if the length is large enough to accommodate the drum 10 and the rectifier 40. The coating liquid supplied from below the drum 10 is prevented from entering the drum 10 by the regulating plate 41.

Another embodiment of the rectifier is shown in FIG. The rectifier 50,
A disc-shaped regulating plate 51 positioned below the drum 10 immersed in the coating liquid in the tank 22 shown in FIG. 3 and three guide tubes 52 arranged on the regulating plate 51 Have. Each guide tube 52 is attached to each through-hole that penetrates the regulating plate 51 in the vertical direction, and the coating liquid supplied from below the regulating plate 51 enters each guide tube 52 from each through-hole. Each guide tube 52
On the horizontal regulating plate 51, the regulating plate 51 is arranged horizontally, and the extension of the axis thereof intersects the inner peripheral surface of the tank 22 at an acute angle of 45 degrees or less. Therefore, each guide tube
From 52, the coating liquid is discharged at an acute angle toward the inner peripheral surface of the tank, and the coating liquid discharged from each guide tube 52 is formed into a swirling flow along the inner peripheral surface of the tank, and from the bottom upward. Flowed through.

The rectifier 50 also has a coating liquid supplied from a supply pipe 32 disposed on the lower surface of the tank 22, similarly to the rectifier 40, and has a drum shape.
The swirl flow is ensured without infiltration into the
10 Flows from the bottom to the top along the outer peripheral surface.

FIGS. 6 and 7 show still another example of the rectifier of the present invention.
Shown in the figure. The rectifier 60 is mounted in the lower part 23a of the tank 23. The lower portion 23a of the tank 23 has a truncated conical shape that is suspended on the lower side and is sequentially reduced in diameter, and the rectifier 60 disposed in the lower portion 23a has a disc-shaped regulating plate 61. . At the center of the regulating plate 61, a core 62 penetrating through the regulating plate 61 is mounted concentrically. The core portion 62 has a shell shape that tapers toward the upper end.

Four guide holes 61a are formed around the central portion of the rule plate 61 to which the core 62 is attached so as to penetrate the rule plate 61. The coating liquid supplied into the tank 23 from the vertical supply pipe 33 connected to the lower part of the tank 23 flows through each guide hole 61a. Each guide hole 61a is formed in a linear shape in which the position of the coating liquid inlet on the lower surface of the regulating plate 61 and the position of the coating liquid outlet on the upper surface of the regulating plate 61 are deviated from the vertical direction. The application liquid inlets of the respective guide holes 61a are disposed at equal intervals in the circumferential direction of the regulating plate 61, and as shown in FIG. in the point of intersection with the tank 23 circumferential surface, to the tangent of the intersection of the tank 23 circumferential surface, and it is the angle theta ₁ of 45 degrees or less. Further, as shown in FIG. 8, when the inclination angle with respect to the horizontal plane of the axial line of the guide holes 61a and theta _2, the inclined angle theta ₂ is smaller than 45 degrees, and the tangent to the inclined angle theta ₂ (Tan θ ₂ ) is the guide hole 61a
A vertical distance y from a point intersecting the axis of the regulating plate 61 to the lower end surface of the drum 10 by horizontally moving the axis of
Θ ₂ is set so that the ratio to the radius x of the drum 10 is smaller than y / x, and therefore tan θ ₂ <y / x. Each guide hole 61a
Are formed such that the angles θ ₁ and θ ₂ of their respective axes satisfy such a condition.

The coating liquid is supplied from the supply pipe 33 into the tank 23 in a state where the drum 10 is immersed in the coating liquid in the tank 23 in which the rectifier 60 for the coating liquid is provided. The coating liquid supplied from the supply pipe 33 penetrates into each guide hole 61a of the coating liquid flow rectifier 60, and flows through the coating liquid outlet of each guide hole 61a.
Is discharged above. At this time, the coating liquid discharged from each guide hole 61a does not enter the drum 10 because the axis of each guide hole 61a is in an inclined state satisfying the predetermined condition as described above. Then, the light is incident on the inner peripheral surface of the tank 23 from below with an inclination of 45 degrees or less with respect to the tangential direction. Thereby, the coating liquid discharged from each guide hole 61a forms a swirling flow along the inner peripheral surface of the tank 20, and flows upward from below. The swirling flow flows along the outer peripheral surface of the drum 10 and overflows from the upper surface of the tank 23. Then, in a state where the coating liquid overflows from the upper surface of the tank 23, the drum 10 is pulled up from the coating liquid in the tank 23, and the coating liquid is uniformly applied to the outer peripheral surface of the drum 10 without causing coating unevenness.

The rectifier 60 can be easily removed from the tank 23 by the central core portion 62.

(Effect of the Invention) As described above, the swirling flow along the outer peripheral surface of the drum immersed in the coating liquid is passed downward or upward to overflow the tank and pull up the drum from the coating liquid. The coating liquid is uniformly applied to the outer peripheral surface of the drum without causing coating unevenness. The coating liquid is supplied vertically from below the drum immersed in the coating liquid, and the supplied coating liquid is swirled by a coating liquid rectifier, so that the coating liquid is swirled in the tank. Space can be reduced.

The rectifier for a coating solution of the present invention has a plurality of linear guide holes through which the coating solution flows vertically in an inclined state, and the guide holes allow the coating solution supplied from below to enter the drum. Since the swirling flow can be ensured without infiltration, the size of the tank can be reduced, and the coating liquid can be surely applied uniformly without causing uneven coating holes.
Further, by setting the guide holes in a predetermined inclined state, the coating liquid does not enter the drum, and the coating liquid can be reliably swirled.

[Brief description of the drawings]

FIG. 1 is a sectional view of a tank showing an example of an embodiment of a drum coating method, FIG. 2 is a plan view thereof, FIG. 3 is a sectional view of a tank in another example of an embodiment of a drum coating method, FIG. FIG. 5 is a perspective view of a coating liquid rectifier used in the method, FIG. 5 is a perspective view of another example of the coating liquid rectifier, and FIG. 6 is a tank showing still another example of the coating liquid rectifier. FIG. 7 is a cross-sectional view, FIG. 7 is a plan view of the same, and FIG. 10 ... Drum, 21,22,23 ... Tank, 31,32,33 ... Supply pipe, 40,50,60 ... Coating liquid rectifier, 41,51,61 ... Regulatory plate, 42 ... Guide part, 52 Guide pipe, 62a Guide hole, 6
2 …… Core part.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Koichi Kigami 1-2-28 Tamazo, Chuo-ku, Osaka-shi, Osaka Mita Kogyo Co., Ltd. (56) References JP-A-64-75064 (JP, A) Kaihei 2-9472 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 5/05 102 B05C 3/02 B05D 1/18

Claims (2)

(57) [Claims] 1. A drum is vertically immersed in a coating solution contained in a tank, the coating solution is supplied to the tank, and the drum is pulled up from the coating solution while overflowing the coating solution from the tank. A rectifier for a coating liquid used in a drum coating method of coating the coating liquid on the outer peripheral surface of the drum, the rectifier being provided in a lower portion of the tank, and a coating liquid supplied from below is provided above the tank. The coating liquid used in the drum coating method, which has a plurality of linear guide holes that flow in a predetermined inclined state toward the tank inner surface without entering the drum immersed in the coating liquid. Rectifier. 2. A drum is vertically immersed in a coating liquid accommodated in a tank, and the coating liquid is supplied to the tank and the drum is pulled up from the coating liquid while overflowing the coating liquid from the tank. A rectifier for a coating liquid used in a drum coating method of coating the coating liquid on the outer peripheral surface of the drum, the rectifier being disposed in a lower portion of the tank, and a coating liquid supplied from below is circulated upward. as to have a plurality of guide holes straight penetrating vertically in a predetermined inclined state at an angle theta ₁ extension line of the axis is less than 45 degrees to the tangent direction of the tank inner surface of the guide hole When they intersect and incline at an angle θ ₂ of 45 degrees or less with respect to the horizontal direction, and the tangent (tan θ ₂ ) to the inclination angle θ ₂ translates the axis of each guide hole in the horizontal direction, From the intersection with the drum axis to the bottom of the drum Less than the ratio of the radius x vertical distance y and the drum inner peripheral face up (tanθ _{2 <y} / x) current piece of coating solution for use in a drum coating wherein the.