JP2002119907A - Extrusion coater and method for deaerating the coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion coater having a structure that can realize high-accuracy coating with a non-Newtonian fluid and a function necessary for its operation and to provide a deaerating method for the coater. SOLUTION: There is provided an extrusion coater 1 that distributes a coating fluid poured into a coating liquid reservoir 3 having a slit 4 with a specified width over a desired width and applies it, wherein the slit 4 is formed by fastening two members 2 and 2' that constitute the slit 4 with a base structure member 5. An air trap pocket 7 is formed along the entire coating width on the slit member upstream of the periphery of a rotary roll 11, and a degassing port 6 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion coating apparatus and a method for removing air from the extrusion coating apparatus.

[0002]

2. Description of the Related Art In the production of many recording materials such as a stimulable phosphor plate, a silver halide photosensitive material and a magnetic recording material, there is a coating step for forming various layers having various functions and characteristics.

In recent years, in order to improve the performance of recording materials and the like, there is a high demand that the thickness of these layers to be formed is small and the variation thereof is small. Furthermore, it is required that the coating liquid can be applied at a high speed, the loss of the coating liquid is small, and it is possible to cope with various kinds of small-quantity production.

[0004] A typical extrusion coating machine structure is composed of two members. One member has a step corresponding to the gap between the liquid reservoir and the slit. The two members are brought into close contact with each other, and the members are fastened at regular intervals with screws to form a slit.

[0005] The slit precision is a method which is substantially determined by the member processing accuracy such as the parallelism of the step, the flatness of the slit surface, and the flatness of the member contact surface. Further, since the warp of each member at the time of processing is fastened along the slit surface, the influence on the slit is relatively small. In the supply of the liquid, a hole is usually formed at the center of the coating machine so as to flow into a liquid reservoir (commonly called a pocket).

Japanese Patent Application No. 2000-068543 discloses a basic device configuration for applying a non-Newtonian fluid. However, the invention does not disclose a device structure for realizing high-precision coating and a function necessary for operation. That is, it is difficult to form the liquid supply section into a long hole shape with a conventional coating apparatus structure. In order to do this, it is not possible to secure slit accuracy only by a method of fastening with a side plate at the end of the coating apparatus or by simply tightly fastening only the slit end. This is because bending occurs due to insufficient rigidity, and when the coater has a long structure, warpage in processing cannot be absorbed.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an extrusion coating apparatus having an apparatus structure for realizing high-precision coating of a non-Newtonian fluid and a function necessary for operation, and the extrusion coating apparatus. Another object of the present invention is to provide an air bleeding method.

[0008]

The above object of the present invention has been attained by the following constitutions.

1. In an extrusion coating apparatus that distributes and coats a coating liquid into a coating liquid retaining section having a slit of a desired width over a desired width, two members constituting the slit are fastened to a base structural member to form a slit. An extrusion coating device.

[0010] 2. The base structural member is 10-50m thick
m, the flatness of the mounting surface of the base structural member in contact with the slit structural member is 0.003 to 0.03 mm, and the flatness of the mounting surface of the slit structural member in contact with the base structural member is 0.00
3 ~ 0.03mm, flatness of slit surface is 0.003 ~
2. The extrusion coating apparatus according to the above item 1, wherein the thickness is 0.03 mm, and the perpendicularity between the base mounting surface and the slit surface is 0.003 to 0.02 mm.

3. A rotating roll is provided near the slit having a desired width inside the coating solution retaining section, a mechanism for applying a uniform shear rate to the coating solution in the width direction is provided, and the parallelism of the base is parallel to the slit width. 2. The extrusion coating apparatus according to the above 1, wherein the rotary roll bearing member is mounted on the base structural member along the reference unevenness having a reference unevenness of 005 to 0.05 mm.

4. 4. The extrusion coating device according to the above item 3, wherein the flatness of the rotary roll bearing member in contact with the base mounting surface is 0.001 to 0.01 mm.

5. A shim for securing a specified slit width is sandwiched at both ends in a slit portion outside a desired width, and an assembling apparatus is assembled to secure slit accuracy.
The extrusion coating device according to any one of the above.

6. 4. The extrusion coating apparatus according to the above item 3, wherein a hole for venting air is provided in the slit constituent member on the upstream side of the outer peripheral position of the rotary roll.

[0015] 7. 7. The extrusion coating apparatus according to the above item 6, wherein the slit constituting member on the upstream side of the outer peripheral position of the rotary roll has a pocket for air accumulation over the entire coating width and a hole for air bleeding.

8. In the initial stage of feeding the solution to the extrusion coating device according to the above item 6, the slit portion is 5 to 15 μm from the slit gap.
An air bleeding method, wherein a thin shim is inserted over the entire length of the slit portion, and air is evacuated from the air bleeding valve to the inside of the coating apparatus in a state where the rotating roll is stopped.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. FIG. 1 is a sectional view of the extrusion coating apparatus of the present invention. The coater 1 is composed of slit components 2 and 2 ′ and forms a slit 4. Then, the slit constituting members 2 and 2 ′ are fastened to the base structural member 5 by screws 14.
As a result, the coating liquid retaining portions 3 and 13 are formed. A rotating roll 11 is provided near the slit 4 having a desired width inside the coating liquid retaining section 3 to apply a uniform shear rate to the coating liquid in the width direction. Further, the reference unevenness 9 is provided in parallel with the base portion slit width, and the rotating roll bearing member 18 (see FIG. 3) is mounted on the base structure member 5 along the reference unevenness 9. A hole 6 for venting air and a pocket 7 for accumulating air are provided in the slit component 2 on the upstream side of the outer peripheral position of the rotary roll 11. The pocket 7 for storing air is provided over the entire coating width of the slit component 2, and a valve 8 is provided above the hole 6 for removing air. By adopting the method of the first aspect and the processing conditions of the second aspect, it is possible to secure slit accuracy while the liquid supply unit has a long hole structure. In addition, by having such a structure, an arbitrary slit gap can be set, and high-precision coating can be performed under a wide range of liquid conditions.

FIG. 2 is a view showing a coater mounting surface of a base structural member 5 on which the coater 1 is mounted. The base structural member 5 to which the coater 1 is attached is tightly fastened by a cylinder 20 having a pressure ram 12 and a bolt 15 having a thumbscrew 16.

The coating solution is separated into the cylinder 20 and the base structural member 5 to which the coater 1 is attached, and is put in a predetermined amount in the coating solution retaining portion 13 of the cylinder with the coater attachment surface facing upward. At this time, the coater 1 is separated from the back roll 10, and the slit 4 is covered with a shim. After the coating liquid is put into the coating liquid retaining section 13, the thumb screw 1
6, tighten the coater horizontally, open the valve 8,
By pressing the pressure ram 12, air is collected in the pocket 7, and all the air in the coating solution retaining sections 3 and 13 is discharged. When the air has run out, the valve 8 is closed, and the shim that has closed the slit 4 is removed. By this operation, the inside air can be evacuated without polluting the coater slit outlet, the coating liquid loss is small, and the coating can be performed better than the head. The coater 1 is set in front of the back roll 10 at regular intervals, and the desired support is
While running upward, the pressing ram 12 is pressed to apply the coating liquid. During the coating, the rotating roll 11 is driven by the motor 17 (FIG. 3).
The connection between the rotating roll and the motor is shown in FIG. 1) to apply a uniform shear rate to the coating liquid in the width direction.

FIG. 4 is a cross-sectional view of the extrusion coating apparatus described in Japanese Patent Application No. 2000-068543. The coater 1 is composed of the slit components 2 and 2 ′ and forms the slit 4. However, since there is no base structural member, the position of the rotating roll 11 is accurately determined with respect to the width by the coating solution retaining section 3. And it is structurally difficult to keep the slit gap constant. In contrast, the present invention provides a coater 1
In contrast, the base structural member 5 and the cylinder 20 having the pressurizing ram 12 were separated, and the position of the rotating roll 11 was accurately determined with respect to the width by the coating solution retaining section 3. Further, when the slit is used upward, there is no problem because air is evacuated from the slit at the time of initial liquid feeding. However, when the coating apparatus is used sideways, air accumulation occurs at the upper part. When the rotating roll is operated in this state, the flow path is blocked by air entrainment, resulting in poor film thickness distribution with streaks. Because of this,
By adopting the structure of claim 6 or 7, and the method of claim 8, air can be removed from the coating apparatus, and defects during the operation of the rotating roll are eliminated.

[0021]

According to the present invention, there is provided an apparatus for extruding a non-Newtonian fluid with high accuracy, an extrusion coating apparatus having a function required for operation, and an air bleeding method for the extrusion coating apparatus. We were able to.

[Brief description of the drawings]

FIG. 1 is a sectional view of an extrusion coating apparatus according to the present invention.

FIG. 2 is a view showing a coater mounting surface of a base structural member on which a coater is mounted.

FIG. 3 is a diagram showing a connection between a rotating roll and a motor.

FIG. 4 is a sectional view of a conventional extrusion coating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coater 2, 2 'Slit component 3 Coating liquid retention part 4 Slit 5 Base structure member 6 Air vent hole 7 Pocket 8 Valve 9 Reference unevenness 10 Back roll 11 Rotating roll 12 Pressure ram 13 Coating liquid retention part of cylinder 14 Screw 15 Bolt 16 Thumb screw 17 Motor 18 Rotary roll bearing member 20 Cylinder

Claims (8)

[Claims] 1. An extrusion coating apparatus for distributing and coating a coating liquid, which has been injected into a coating liquid retaining section having a slit of a desired width, over a desired width, and applying two members constituting the slit to a base structural member. An extrusion coating device characterized by forming a slit by fastening. 2. The base structural member has a thickness of 10 to 50 mm,
The flatness of the mounting surface of the base structural member in contact with the slit structural member is 0.003 to 0.03 mm, and the flatness of the mounting surface of the slit structural member in contact with the base structural member is 0.003 to 0.003.
0.03 mm, the flatness of the slit surface is 0.003 to 0.
2. The extrusion coating device according to claim 1, wherein the perpendicularity between the base mounting surface and the slit surface is 0.003 to 0.02 mm. 3. A rotating roll is provided near a slit having a desired width inside the coating liquid retaining section, a mechanism for applying a uniform shear rate in the width direction to the coating liquid is provided, and the base is parallel to the slit width. 2. The extrusion coating apparatus according to claim 1, wherein the rotating roll bearing member is mounted on the base structural member along the reference unevenness with a parallelism of 0.005 to 0.05 mm. 4. The extrusion coating apparatus according to claim 3, wherein the flatness of the rotary roll bearing member in contact with the base mounting surface is 0.001 to 0.01 mm. 5. A slit for securing a prescribed slit width in a slit portion outside a desired width is sandwiched at both ends, and a coating apparatus is assembled to secure slit accuracy.
The extrusion coating device according to any one of the above. 6. The extrusion coating apparatus according to claim 3, wherein a hole for bleeding air is provided in the slit member upstream of the outer peripheral position of the rotary roll. 7. The extruder according to claim 6, wherein the slit constituting member on the upstream side of the outer peripheral position of the rotary roll has a pocket for collecting air over the entire coating width and a hole for removing air is provided. Coating device. 8. At the initial stage of feeding the solution to the extrusion coating device according to claim 6, the slit portion has a width of 5 to 15 μm from the slit gap.
An air bleeding method, wherein a thin shim is inserted over the entire length of the slit portion, and air is evacuated from the air bleeding valve to the inside of the coating apparatus in a state where the rotating roll is stopped.