JPH0550001A - Coating device - Google Patents

Abstract

PURPOSE:To uniformize a mixing concn. and film thickness and to prevent the clogging of a supply path with liquid over the entire part thereof at the time of applying the liquid of a solid-liquid dispersion system. CONSTITUTION:A cylindrical rotating body 9 which is freely rotatably supported in parallel with the longitudinal direction of a slit port 4 is provided near the slit port 4 of the liquid pool part 2 in an extrusion coater 1. Many stirring blades 10, 10 intersecting with the center line of rotation of the rotating body 9 are provided at spaced intervals over the entire part of the outer periphery of this rotating body 9. Static mixers 20A to 20N are provided in the supply path 20, and further, a stirrer 31 is provided in a coating liquid tank 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating device capable of uniformly coating a liquid of a solid-liquid dispersion system and preventing liquid clogging throughout the coating liquid feed passage.

[0002]

2. Description of the Related Art For example, when a blood analysis element is manufactured, a solid content such as antibody powder is contained in a solvent to be applied, so that the precipitation and agglomeration of the solid matter become a problem during the application. Cannot be coated on the support at a uniform mixed concentration. In addition, when applying a non-setting type coating liquid, in the drying step after coating, the coating speed is often determined to be low due to the restriction from the drying capacity of the existing drying device. When attempting to apply the solid-liquid dispersion type coating liquid below, there are cases in which the liquid cannot be applied due to liquid clogging due to sedimentation and aggregation of solids throughout the liquid passage.

Conventionally, when applying a liquid of a solid-liquid dispersion system,
For example, in Japanese Utility Model Laid-Open No. 2-137971, as shown in FIG. 6, a rotary shaft 41, which is rotatably supported by a drive means 43, is provided in a liquid reservoir in a coater 40, and the rotary shaft 41 is also provided. Stirring blades 42, 4 in place
There is a disclosure of an apparatus in which solids are prevented from settling by fixing 2 and forcibly stirring the coating liquid in the liquid reservoir.

[0004]

However, since the area stirred by the stirring device in Japanese Utility Model Laid-Open No. 2-137971 is limited to the substantially peripheral area where the stirring blades 42 are arranged, the inside of the liquid reservoir is It is extremely difficult to uniformly stir the entire region, and in the region below the stirring blade 42, solid precipitation is unavoidable and solids are aggregated. In addition, if an attempt is made to stir the entire liquid reservoir by increasing the number of revolutions of the stirring blade 42, the stirring force will be too large and a dynamic pressure distribution will be generated in the stirring process.
There is a problem that pulsation occurs in the coating liquid discharged from the tip of the slit mouth and the film thickness becomes uneven. Even if it is possible to prevent sedimentation and aggregation in the coating coater, good quality coating cannot be realized if sedimentation / aggregation or liquid clogging occurs in the supply path to the coating coater.

Therefore, the main object of the present invention is to apply a coating liquid which easily aggregates, to prevent settling / aggregation of solids throughout the coating liquid path, and to eliminate the dynamic pressure of the coating liquid for uniform coating. The present invention provides a coating device that enables the above.

[0006]

[Problems to be Solved by the Invention] The problems described above include a coating coater having a liquid reservoir inside the coater, and a slit port communicating from the liquid reservoir to the outside, and a coating liquid supplied to the coating coater. In the coating device, which comprises a supply passage for storing the coating liquid and a coating liquid tank for storing the coating liquid, and which coats the surface of a continuously running support, in the vicinity of the slit mouth of the coating coater liquid reservoir. , A cylindrical rotating body that is rotatably supported parallel to the longitudinal direction of the slit mouth, and has a large number of pieces that intersect the rotation center line of the rotating body at intervals over the entire outer peripheral surface of the rotating body. This can be solved by providing a blade or spiral blade, providing a static stirring means in the supply passage, and further providing a stirring means in the coating liquid tank.

[0007]

In the coating apparatus of the present invention, first, a cylindrical rotary member that is rotatably supported parallel to the longitudinal direction of the slit mouth is provided in the liquid reservoir inside the coating coater, and the entire outer peripheral surface of the rotary member is provided. The blade-shaped stirring means is provided with a large number of single-sided blades or spiral blades intersecting the center line of rotation of the rotating body at intervals. According to this blade-shaped stirring means, since the coating liquid in the area near the slit mouth is stirred while being sheared,
No pulsation occurs. Since the coating liquid is constantly dispersed by the shear flow, even if there is sedimentation of solids from above the liquid reservoir, sedimentation / aggregation of solids is prevented and a uniform mixed concentration is obtained from the slit mouth. Since the coating liquid is applied, the uniformity of the film thickness is ensured. Further, since the static stirrer such as a static mixer is provided in the supply passage of the coating liquid, sedimentation / aggregation in the supply passage is prevented. Further, the coating liquid tank is also provided with a stirring means to prevent sedimentation / aggregation.

As described above, in the present invention, since various stirring means are provided throughout the coating liquid feeding section, the coating speed is slow and the coating liquid is a solid-liquid dispersion system. Even under conditions, liquid clogging due to liquid sedimentation is prevented, and good application is secured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. In FIG. 1, the coating liquid 8 in which the solid-liquid content is stirred in the coating liquid tank 30 by the stirrer 31 is
2 is sent to the extrusion coater 1 via the supply pipes 20A to 20N. As shown in FIG. 2, the extrusion coater 1 has a slit port 4 that communicates with a liquid reservoir 2 in the coater 1 at a portion facing a support 6 that continuously runs with a backup roll 5, and a liquid supply port. The coating liquid 8 supplied from the liquid reservoir 3 to the liquid reservoir 2 is discharged from the slit port 4 by the action of pressure and gravity and applied to the support 6. A curvature of R3 mm or more is provided at the entrance of the slit 4 to make the outflow of the coating liquid smooth.

In the vicinity of the slit port 4 in the liquid reservoir 2 of the extrusion coater 1, there is provided a cylindrical rotating body 9 which is rotatably supported parallel to the longitudinal direction of the slit port 4,
A large number of flaky stirring blades 10 and 1 that intersect the rotation center line of the rotating body 9 at intervals over the entire outer peripheral surface of the rotating body 9.
0 ... is provided. The rotating body 9 has a slit opening 4
It is arranged in the vicinity of the slit port 4 in order to cause a shear flow in the peripheral region of the and to disperse the coating liquid. Specifically, the clearance C between the tip of the stirring blade 10 and the slit port 4 is preferably set to 3 to 4 mm. The rotation speed of the rotating body 9 is in the range of 50 rpm to 30,000 rpm,
The speed is preferably 500 rpm to 3000 rpm. 50rp
If it is less than m, stirring cannot be completed and agglomeration occurs.
When it exceeds rpm, a dynamic pressure distribution is generated in the liquid reservoir 2. An electromagnetic motor or the like is preferably used as the driving means of the rotating body 9, but if it is directly attached to the outer wall of the die 1, resonance occurs and uniform coating cannot be performed. It is desirable to let

The stirring blades 10, 10 may be arranged in a staggered shape or a spiral shape, but as shown in FIG. 3, preferably, they are arranged at random over the entire outer peripheral surface of the rotating body 9 at intervals. , When the rotating body 9 is rotated,
The pitch is preferably narrowed so that the stirring regions of the stirring blades 10, 10 ... Have overlapping portions with each other.

As shown in FIG. 4, the shape of the stirring blade 10 is preferably such that the stirring can be carried out so as not to generate a dynamic pressure distribution in the liquid reservoir 2 in the stirring process and to cause a shear flow. Has a height h = 0.5 to 5 mm and a width w = 2 to 10 mm. Further, the inclination angle θ of the stirring blades 10, 10 ... with respect to the rotation center line of the rotating body 9 is 5 to 80.
The degree is preferably 30 to 60 degrees.

By the way, instead of the stirring blade 10, as shown in FIG.
It is also possible to provide a continuous spiral blade 11 as shown in FIG. The height and width of the spiral blade 11, the inclination angle θ, the clearance C between the tip of the spiral blade 11 and the slit port 4 and the number of revolutions are the same as those of the stirring blade 10.

On the other hand, a static mixer 20A, 20B, ..., 20N, which is a static stirrer, is connected in series to a supply path 20 connecting the coating solution tank 30 and the extrusion coater 1.

As is well known, the static mixers 20A ... The elements 21, 21 ... Each of which is formed by twisting both ends of a plate by 180.degree.
It is a type of flow mixer that mixes using the kinetic energy of its own liquid flow. An orifice mixer or the like may be used instead of the static mixer.

(Examples) Next, the effects of the present invention will be clarified by examples. In this example, an extruding coater having no stirring means (Comparative Example 1) and an extruding coater having an edge stirring means shown in FIG. Flow rate 200
Coating was performed at cc / min, and the state of the liquid reservoir and the coating state during coating were observed. The shape and arrangement of the stirring blade 10 are
The height h = 3 mm, the width w = 5 mm, the inclination angle θ = 45 degrees, and the rotation speed of the rotating body 9 is 20 to 50 rpm (case 1), 100.
rpm (case 2), 500 rpm (case 3), 1000
rpm (Case 4). The results are shown in Table 1.

As shown in FIG. 1, a static mixer was provided in the coating liquid supply path to prevent the liquid clogging in the supply path.

[0018]

[Table 1]

From Table 1, in Comparative Example 1, when the difference in specific gravity between the powder and the solvent is 1 to 1.5, the slit mouth is clogged. It was non-uniform in the longitudinal direction. Case 1 (20) of the present invention
.About.50 rpm), the stirring force was insufficient and pulsation was confirmed regardless of the difference in specific gravity. Case 2 (100 rpm)
In the case of 1, the coating was satisfactorily performed when the difference in specific gravity between the powder and the solvent was 1 to 1.5, but in the case of 1.5, the stirring force was insufficient. On the other hand, Case 3 (500rp)
m) and Case 4 (1000 rpm), it was possible to apply with a uniform mixed concentration and a uniform film thickness. Also, the liquid clogging in the middle of the supply passage could be almost eliminated by the static mixer.

[0020]

As described above, according to the present invention, even a liquid of a solid-liquid dispersion system containing a solid that easily agglomerates can be applied with a uniform mixed concentration and a uniform film thickness. It is possible to prevent liquid clogging in the supply path.

[Brief description of drawings]

FIG. 1 is an overall schematic view of a coating apparatus according to the present invention.

FIG. 2 is an enlarged vertical sectional view of the extrusion coater of the present invention.

FIG. 3 is an overall perspective view of a blade-shaped stirring unit.

FIG. 4 is an enlarged view of a stirring blade according to the present invention.

FIG. 5 is a side view of another example of the blade-shaped stirring means.

FIG. 6A 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 ... Extrusion coater, 2 ... Liquid reservoir, 4 ... Slit port, 6
... Support, 8 ... Coating liquid, 9 ... Rotating body, 10 ... Stirring blade, 1
1 ... spiral blade

Claims (1)

[Claims] 1. A coating coater having a liquid reservoir inside the coater and having a slit opening communicating from the liquid reservoir to the outside, a supply path for supplying the coating liquid to the coating coater, and coating. In a coating device which is composed of a coating liquid tank for storing liquid, and which coats the surface of a continuously running support, in the vicinity of the slit mouth of the coating coater liquid reservoir, parallel to the longitudinal direction of the slit mouth. A rotatably supported cylindrical rotor is provided, and a large number of single blades or spiral blades that intersect the center line of rotation of the rotor at intervals are provided on the entire outer peripheral surface of the rotor. At the same time, a static stirring unit is provided in the supply path, and a stirring unit is further provided in the coating liquid tank.