JPH0639341A - Continuous coating method for metal web - Google Patents

Abstract

PURPOSE:To provide the continuous coating method for a metal web which forms a film of good appearance and without uneven coating and the like and provide the industrial advantage. CONSTITUTION:In the coating method in which metal webs 1 transferred continuously are brought into contact with an applicator roll 3 with a back-up roll 2 in contact with the rear faces of the webs, a roll of flexible material roll is used as the back-up roll 2 and a metal roll is used as the applicator roll 3, and a coating material is discharged onto the applicator roll 3 through a die 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous coating method for metal webs, and more particularly to an industrially advantageous continuous coating method for metal webs which provides a coating film with good appearance without coating unevenness. is there.

[0002]

2. Description of the Related Art Conventionally, various methods have been known as a continuous coating method for continuously transferring webs. Most of them are roll coating methods using a coating roll. Recently, a die coating method using a die has attracted attention. The die coating method is basically a method in which a coating material is directly discharged through a die onto a web wound around a backup roll and continuously transferred. Such a die coating method has many advantages over the conventional roll coating method such that the film thickness can be easily controlled and the coating unevenness due to the agglomerates of the coating liquid is small.

Several proposals have been made for the above-mentioned die coating method.
No. 17259, a high-rigidity transfer roll and a flexible applicator roll are provided between a slit die and a backup roll as a coating machine for implementing the above-mentioned die coating method by an improved method. Arranged coating machines have been proposed.

By the way, the proposal by Japanese Utility Model Laid-Open No. 2-17259 is made based on the following reasons.
That is, in the conventional coating machine in which the flexible applicator roll is arranged between the slit die and the backup roll, the accuracy of the outer diameter processing of the applicator roll is low, so that the slit nozzle and the applicator roll are However, there is a drawback that unevenness in the coating easily occurs due to variations in the gap. The coating machine according to Japanese Utility Model Laid-Open No. 2-17259 disposes a highly rigid transfer roll between a slit die and a flexible applicator roll in order to solve such a drawback. The reason why the applicator roll is made of a flexible material such as rubber is that the surface of the web is not very uniform.
This is because it is necessary to adapt the roll surface to the surface shape.

[0005]

However, in the continuous coating method using a coating machine according to Japanese Utility Model Laid-Open No. 2-17259, it is sure that variation in the gap between the slit nozzle and the applicator roll is prevented, and coating unevenness occurs. Although a coating film having a good appearance can be obtained without such problems, the structure of the device is complicated and thus there is a problem in operability, and it is not necessarily an industrially advantageous method. The object of the present invention is,
Similar to the proposal of Japanese Patent Publication, the gap between the slit nozzle and the applicator roll is prevented from variation, and there is a point of providing a continuous coating method in which a coating film having good appearance without coating unevenness can be obtained, but in particular, metal As a continuous web coating method, there is a point to provide an industrially advantageous continuous coating method with excellent operability.

As a result of various studies to achieve the above object, the present inventors have surprisingly found that if a flexible material roll is used as the backup roll, a metal roll is used as the applicator roll. Even when used, the present inventors have found that even for a web whose surface is not so uniform, the applicator roll surface can be adapted to the surface shape to achieve good coating, and the present invention has been completed. That is, the gist of the present invention is a method of coating a continuously transferred metal web by bringing the backup roll into contact with an applicator roll with the back face as a back face, using a flexible material roll as the backup roll, A continuous coating method for a metal web is characterized in that a metal roll is used as the troll and the coating material is discharged through a die into the applicator roll.

The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an explanatory view showing an example of the method of the present invention, in which (1) is a metal web, (2) is a backup roll, (3) is an applicator roll, and (4) is a die.

The method of the present invention is a continuous coating method for metal webs, and examples of the metal web (1) include webs of aluminum, stainless steel, steel, plated steel and the like, and the thickness thereof is usually It is about 0.05 to 1 mm.
As the paint, any of various kinds can be used. For example, a clear coating containing a fluororesin, a polyester resin or the like, a metallic coating containing aluminum powder, brass powder or the like as a metallic pigment, and an acrylic resin or an alkyd resin as a vehicle resin component, and the like can be mentioned.

In the method of the present invention, the metal web (1), which is continuously transferred, is applied by contacting it with the applicator roll (3) with the backup roll (2) as the back surface. Then, a flexible material roll is used as the backup roll (2), and a metal roll is used as the applicator roll (3). As the flexible material forming the backup roll (2), NBR, E
Examples include PDM, urethane rubber, silicon rubber, and fluorine rubber, as well as soft plastic and soft PVC. In particular, the rubber hardness is 30 to 100, preferably 40 to
70 hard rubber is preferred.

In the method of the present invention, since the applicator roll (3) is made of metal, it is possible to perform highly accurate outer diameter processing, and the slit nozzle of the die (4) and the applicator roll (3) can be processed. There is no variation in the gap between and. Further, in the method of the present invention, since the metal web (1) is in contact with the applicator roll (3) with the backup roll (2) using a roll made of a flexible material as the back surface, the metal web (1) is Even if there is a non-uniform portion on the surface, the roll surface of the applicator roll (3) can be adapted to the surface shape.

In the method of the present invention, the rotating direction of the applicator roll (3) and the rotating direction of the backup roll (2) may be opposite or the same. In the method of the present invention, the coating material is transferred to the applicator roll (3) by discharging the coating material through the die (4). As the die (4), those having various conventionally known structures can be used. The die (4) is placed in close proximity such that the die lip is oriented straight with respect to the centerline of the applicator roll (3). Further, in the present invention, since the applicator roll (3) is made of metal, it is possible to perform highly accurate outer diameter processing, and the gap between the slit nozzle of the die (4) and the applicator roll (3). Does not vary.

[0012]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In addition, the main specifications of the metal web, the paint, and the coating device used in the following examples are:
It is as follows. (1) Metallic web 0.5 mm thick and 1600 mm wide aluminum sheet (1100-H14 material) (2) Paints The following clear paints ("Lumiflon" manufactured by Asahi Glass Co., Ltd.) Resin: Fluorine resin Solid content: 45 wt% Melt Medium: Organic solvent Viscosity: 80 seconds (Ford cup, 20 ° C)

(3) Coating device (a) Die slit spacing: 270 μm (b) Applicator roll: Iron roll with a chrome-plated roll surface (diameter 300 mm) (c) Distance between die lip tip and applicator roll:
50 μm (within ± 5 μm in the width direction) (d) Backup roll: Hard rubber roll with hardness 50 (diameter 300 mm)

Example 1 In the coating apparatus shown in FIG. 1, the applicator roll and the backup roll were rotated in opposite directions, the pressure of the coating material supplied to the die was 2.5 Kg / cm ² G, and the discharge amount of the coating material was 2
Continuous coating was performed with a coating width (die width) of 1592 mm at 500 ml / min and a running speed of the metal web of 20 m / min. The coated metal web was dried through a 20 m long drying oven. As a result of the above continuous coating, the film thickness is 20μ
m, and a coating web having an extremely good coating appearance was obtained. Continuous coating was performed up to a web length of 1000 m, and stable coating was confirmed.

[0015]

INDUSTRIAL APPLICABILITY According to the present invention described above, an industrially advantageous continuous coating method for a metal web that provides a coating film having good appearance without coating unevenness and the like is provided, and the industrial value of the present invention is great. .

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a method of the present invention.

[Explanation of symbols]

 (1): Metal web (2): Backup roll (3): Applicator roll (4): Die

Claims (4)

[Claims] 1. A method of coating a continuously transferred metal web by contacting an applicator roll with a backup roll as a back surface, wherein a roll made of a flexible material is used as the backup roll and the applicator roll is used. A continuous coating method for a metal web, which comprises using a metal roll and discharging the coating material through a die into the applicator roll. 2. The method according to claim 1, wherein the direction of rotation of the applicator roll and the direction of rotation of the backup roll are opposite. 3. The method according to claim 1, wherein the rotation direction of the applicator roll and the rotation direction of the backup roll are the same. 4. The method of claim 1, wherein the flexible material is hard rubber.