JPH0515829A - Extrusion coater with stirrer - Google Patents

Abstract

PURPOSE:To obtain the extrusion coater which can execute uniform coating by stirring only the region near the slit port of a liquid pooling part so as to generate shearing flow and disperses a coating liquid having an easy tendency to agglomeration. CONSTITUTION:Many blade-shaped stirring pieces 10 groups which generate the shearing flow in the fixed liquid are provided over the entire part of the outer peripheral surface of a cylindrical rotating body 9 supported freely rotatably in parallel with the longitudinal direction of the slit port 4 of the liquid pooling part 2 so as to intersect with the center line of rotation of the rotating body 9 apart spaced intervals. The coating liquid 8 near the slit port 4 is sheared and stirred in this way and, therefore, the shearing flow is generated in the region near the slit port and the coating liquid is incessantly dispersed. Then, even if there is the settlement of solid from the upper part of the liquid pooling part, the solid is prevented from agglomerating and the application of the coating liquid at uniform mixing concn. from the slit port is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion coater equipped with a stirrer for uniformly applying a liquid of a solid-liquid dispersion system.

[0002]

2. Description of the Related Art It is known that an extrusion coater as shown in FIGS. 4A, 4B and 5 is used when applying a liquid of a solid-liquid dispersion system. This apparatus mainly includes a die 1, a slit port 4, and a liquid reservoir 2 that is a space formed in the die 1, and a coating liquid 8 supplied from the liquid supply port 3 into the liquid reservoir 2 is provided. Is discharged from the tip of the slit port 4 and is applied to the surface of the support 6 that continuously runs by the backup roll 5 or the like.

However, the above extrusion coater has the following problems. That is, when there is a large difference in density between the solid and liquid mixed in the coating liquid 8, the liquid reservoir 2
The solid 7 settles down below the coating liquid 8 and the coating liquid 8 cannot be applied to the surface of the support 6 at a uniform mixed concentration. Further, the settled solid 7 aggregates to clog the slit port 4. It will also end up.

As an extrusion coater for solving the above problems, for example, the one disclosed in Japanese Utility Model Laid-Open No. 2-137971 can be cited. This is shown in FIG.
As shown in (A) and (B), a rotary shaft 20 rotatably supported by the liquid reservoir 2 in the die 1 is provided, and a stirring blade 21 is fixed to the outer peripheral surface of the rotary shaft 20 to rotate the rotary shaft 20. The shaft 20 is connected to a driving unit 22, and the driving unit 22 rotates the rotating shaft 20 and the stirring blades 21 to generate a stirring flow in the liquid reservoir 2 to remove all the coating liquid 8 in the liquid reservoir 2. The solid is prevented from settling by forcibly stirring, the coating liquid 8 is discharged from the slit port 4 at a uniform mixed concentration, and is uniformly coated on the surface of the continuously running support 6.

[0005]

However, in reality, the region where the stirring blade 21 of the apparatus disclosed by Japanese Utility Model Laid-Open No. 2-137971 described above can stir is the stirring blade 2.
It is extremely difficult to uniformly agitate the entire area within the liquid reservoir 2 only in the substantially peripheral area where 1 is disposed, and in the area below the agitating blade 21, as described above, solid sedimentation still occurs. Is inevitable, and solids will aggregate.

Further, even if the whole of the liquid reservoir 2 can be stirred by increasing the number of rotations of the stirring blade 21, such stirring blade 21 has too much stirring force and produces a dynamic pressure distribution in the stirring process. As a result, the liquid discharged from the tip of the slit port 4 and applied to the surface of the support body 6 pulsates, and the film thickness becomes uneven.

Therefore, the main object of the present invention is not to agitate the entire liquid reservoir, but to agitate only the area near the slit mouth so that shear flow occurs, and evenly disperse the coating solution that easily agglomerates. It is to provide an extrusion coater that can be applied.

[0008]

The above problem is provided with a die, a slit opening, and a liquid reservoir which is a space formed in the die, and the coating liquid supplied to the liquid reservoir is In an extrusion coater that discharges from a slit port and coats the surface of a continuously running support, the liquid is rotated by a rotation driving unit that is rotatably supported in the liquid reservoir parallel to the longitudinal direction of the slit port. With a cylindrical rotating body
A large number of blade-shaped stirring means for causing a shear flow in a liquid fixed to intersect the rotation center line of the rotating body at intervals over the entire outer peripheral surface of the rotating body are provided, and the rotating body is provided with the slit opening. It can be solved by arranging it in the vicinity of.

Further, it is provided with a die, a slit port, and a liquid reservoir which is a space portion formed in the die, and the coating liquid supplied to the liquid reservoir is discharged from the slit port and continuously. In an extrusion coater for coating on the surface of a support that travels in a vertical direction, a cylindrical rotating body that is rotated by a rotation driving means that is rotatably supported in parallel with the longitudinal direction of the slit opening is provided in the liquid reservoir. The problem can be solved by fixing a spiral blade that causes a shear flow to the liquid on the outer peripheral surface of the rotating body, and further disposing the rotating body in the vicinity of the slit mouth.

[0010]

In the extrusion coater of the present invention, the liquid reservoir is provided with a cylindrical rotary member which is rotatably supported in parallel with the longitudinal direction of the slit opening and is rotated by the rotary driving means.
A large number of blade-shaped stirring means for causing a shear flow in the liquid fixed to intersect the rotation center line of the rotating body at intervals over the outer peripheral surface of the rotating body or fixed to the outer peripheral surface of the rotating body. With a spiral blade that creates a shear flow in the liquid,
Since the coating liquid in the region near the slit mouth is agitated while being sheared, a shear flow occurs in the region near the slit mouth, and the coating liquid is constantly dispersed, so that even if the solid precipitates from above the liquid reservoir, Even if there is, it is possible to prevent the solid from aggregating, and it is possible to apply the coating liquid at a uniform mixed concentration from the slit port.

Further, in the blade-shaped stirring means according to the present invention,
Unlike conventional stirring blades, it is possible to achieve film thickness uniformity without pulsation.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the embodiments shown in the drawings.

FIG. 1 is a cross-sectional view of an extrusion coater according to the present invention. This apparatus mainly comprises a die 1, a slit port 4 and a liquid reservoir 2 which is a space portion formed in the die 1. ing.

In such an apparatus, the coating liquid 8 is supplied from the liquid supply port 3 to the liquid reservoir 2 from a separate coating liquid tank (not shown), and the coating liquid 8 is applied by the pressure and gravity of the liquid reservoir 2. Is discharged from the slit opening, and the backup roll 5 applies the coating to the continuously running support 6. Extrusion coaters of this kind are known.

On the other hand, when applying a liquid of a solid-liquid dispersion system using this apparatus, if the difference in density between the solid and the liquid is large, the solid will settle below the liquid reservoir 2 and the slit 4 will Not only can it not be applied with a uniform mixed concentration, but further, the settled solids may aggregate and clog the slit port 4, resulting in a discharge failure.

On the other hand, if all of the liquid reservoir 2 is agitated by the agitating blade as described above, a dynamic pressure distribution is generated in the agitation process, resulting in pulsation and uneven film thickness. .

Therefore, in the present invention, as shown in FIGS. 1 and 2, the liquid reservoir 2 is rotated by a rotation drive means (not shown) rotatably supported in parallel with the longitudinal direction of the slit port 4. A large number of blade-like stirring means which are provided with a cylindrical rotating body 9 and which cause a shear flow in a liquid which is fixed to intersect the rotation center line of the rotating body 9 at intervals over the entire outer peripheral surface of the rotating body 9. A group of 10, 10 ... Is provided, and the rotating body 9 is arranged in the vicinity of the slit port 4.

As shown in FIG. 3, the blade-shaped stirring means 10 has a height h so that it can be stirred so as to generate a shear flow without causing a dynamic pressure distribution in the liquid reservoir 2 during the stirring process. = 0.5-5.00 mm, width w = 2.00
It is preferable that the thickness is ˜10.00 mm. Further, the inclination angle θ of the blade-shaped stirring means 10, 10 ... Group with respect to the rotation center line of the rotating body 9 is preferably 5 to 80 degrees, particularly preferably 30 to 60 degrees.

The arrangement of the blade-shaped stirring means 10, 10 ... Group on the outer peripheral surface of the rotating body 9 is staggered or spiral, or as shown in FIG.
It is desirable to arrange them at random over the entire outer peripheral surface, and when the rotating body 9 is rotated at a high speed, it is necessary to narrow each pitch so that all the blade-shaped stirring means 10, 10 ... Group overlap each other.

On the other hand, in the area near the slit mouth 4,
In order to cause a shear flow and disperse the coating liquid, the rotating body 9 is arranged in the vicinity of the slit mouth 4, and the clearance C between the tip of the blade-like stirring means 10 and the slit mouth 4 is 3 to 4 mm. Preferably.

The number of rotations of the blade-shaped stirring means 10, 10 ...
If it is less than 50 rpm, the stirring cannot be completed, and if it is more than 30,000 rpm, a dynamic pressure distribution is generated in the liquid reservoir 2, so 50 rpm to 3 rpm.
It is preferably in the range of 0000 rpm, more preferably 500 rpm to 3000 rpm.

Further, the rotating body 9 and the blade-shaped stirring means 10 ...
A motor is mentioned as a driving means for rotating the group, but if it is directly attached to the outer wall of the die 1, resonance occurs and uniform coating cannot be performed, so it is desirable to rotate the rotating body 9 by a belt drive. .

On the other hand, FIG. 4 is a side view showing another embodiment of the present invention. In place of the blade-shaped stirring means 10, 10 ... Group, a shear flow is generated in the liquid on the outer peripheral surface of the rotating body 9. The spiral blade 11 is fixed. The spiral blade 11
Height, inclination angle with respect to the rotation center line of the rotating body 9, clearance between the tip of the spiral blade 11 and the slit port 4,
The number of revolutions and other structures of the spiral blade 11 are the same as those of the device in the above-mentioned embodiment, and the same effects can be obtained.

In a preferred embodiment of the extrusion coater of the present invention, as shown in FIG. 1, the slit 4 of the die 1 is provided with a curvature of R3 mm or more at the entrance of the slit 4.

(Examples) Next, the effects of the present invention will be clarified by examples. In this example, two types of extrusion coaters were prepared: a coater having no stirring means (Comparative Example 1) and a coater having blade-shaped stirring means as shown in FIGS. 1 and 2 (Example).

The height of the blade-shaped stirring means is h
= 3 mm, width w = 5 mm, and inclination angle θ = 45 degrees.

Then, using the coater of the above two embodiments,
A liquid of a solid-liquid dispersion system having a liquid viscosity of 30 cp was applied at a flow rate of 200 cc / min, and the state of the liquid reservoir and the applied state during the application were observed.

For coating using a coater having a blade-shaped stirring means, the rotation speed of the blade-shaped stirring means is 20 to 5.
0 rpm (Example 1), 100 rpm (Example 2), 500
rpm (Example 3) and 1000 rpm (Example 4), respectively.

[0029]

[Table 1]

As a result, in Comparative Example 1, when the difference in specific gravity between the powder and the solvent was 1 to 1.5, the slit mouth was clogged. It was uneven in the direction. Example 1 (20 to 50 rpm
In (), irrespective of the difference in specific gravity, the stirring force was insufficient and pulsation was confirmed.

In Example 2 (100 rpm), good coating was achieved when the difference in specific gravity between the powder and the solvent was 1 to 1.5, but insufficient stirring power when the difference was 1.5 to 1.5. Met.

On the other hand, in Example 3 (500 rpm) and Example 4 (1000 rpm), coating could be performed with a uniform mixed concentration and a uniform film thickness.

[0033]

As described above, according to the present invention, even a liquid of a solid-liquid dispersion system containing a solid that easily aggregates can be applied with a uniform mixed concentration and a uniform film thickness.

[Brief description of drawings]

FIG. 1 is a sectional view showing an extrusion coater of the present invention.

FIG. 2 is a perspective view showing an arrangement state of blade-shaped stirring means according to the present invention.

FIG. 3 is an explanatory view showing a blade-shaped stirring means according to the present invention.

FIG. 4 is a side view showing another embodiment of the present invention.

FIG. 5A is a front view showing a conventional extrusion coater. (B) is a side view of (A).

FIG. 6 is an operation explanatory view of a conventional extrusion coater.

FIG. 7A is a sectional view showing an extrusion coater having a conventional stirring blade. (B) is a view taken along the line I-I of (A).

[Explanation of symbols]

1 die 2 liquid reservoir 4 slit mouth 6 support 8 coating liquid 9 rotating body 10 Edge stirring means 11 spiral blade

Claims (2)

[Claims] 1. A die, a slit port, and a liquid reservoir, which is a space portion formed in the die, are provided, and the coating liquid supplied to the liquid reservoir is discharged from the slit port and continuously. In an extrusion coater for coating on the surface of a support that travels in a horizontal direction, a cylindrical rotating body that is rotated by a rotation driving means that is rotatably supported in parallel with the longitudinal direction of the slit opening is provided in the liquid reservoir. , A plurality of blade-shaped stirring means for causing a shear flow in a liquid fixed to intersect with the rotation center line of the rotating body at intervals over the entire outer peripheral surface of the rotating body, and further, the rotating body is provided with the slits. An extrusion coater with a stirrer, which is arranged near the mouth. 2. A die, a slit port, and a liquid reservoir which is a space portion formed in the die, and the coating liquid supplied to the liquid reservoir is discharged from the slit port and continuously. In an extrusion coater for coating on the surface of a support that travels in a horizontal direction, a cylindrical rotating body that is rotated by a rotation driving means that is rotatably supported in parallel with the longitudinal direction of the slit opening is provided in the liquid reservoir. An extrusion coater with a stirrer characterized in that a spiral blade that causes a shear flow in the liquid is fixed to the outer peripheral surface of the rotating body, and the rotating body is arranged in the vicinity of the slit mouth.