Dynozzle and electrostatic coating apparatus using the dynozzle

Abstract

To provide a die nozzle obtaining coating film having a uniform thickness.SOLUTION: A die nozzle includes: a nozzle applying coating material on a substrate continuously travelling on a roll; and a liquid feeding means supplying the coating material to the nozzle. When it is defined that a side where the substrate approaches the nozzle is an upstream side and a side where the substrate releases from the nozzle is a downstream side, the nozzle is composed of a first block forming an upstream nozzle and a second block forming a downstream nozzle along the travelling direction of the substrate, and has a charging electrode applying potential forming a potential gradient between the roll and the nozzle.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] The present invention relates to a nozzle for forming a functional film by applying and drying a functional paint composed of a functional powder, a binder resin, and a solvent to a substrate, and a coating apparatus using the nozzle.

Background Art

[0002] As conventional coating apparatuses, there are those that directly apply a functional paint to a substrate using a nozzle, a gravure plate, etc. to form a functional film. There are also those that atomize a functional paint using an air-assisted spray, an ultrasonic spray, etc. and apply it to the substrate in a non-contact manner to form a functional film.

[0003] Also, as a conventional coating apparatus, there is one that atomizes a functional paint in advance with an ultrasonic element, applies an electric charge to the floating paint, and applies it to a substrate serving as a counter electrode (see, for example, Patent Document 1). FIG. 9 is a schematic diagram showing the configuration of the conventional coating apparatus described in Patent Document 1. Also, as a conventional coating apparatus, there is one that applies an electric charge to a functional paint in advance and draws a thin line on a substrate serving as a counter electrode (see, for example, Patent Document 2). FIG. 10 is a schematic diagram showing the configuration of the conventional coating apparatus described in Patent Document 2.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration of Patent Document 1, the atomized paint floats in the tank and is then discharged in the vertical direction. Therefore, when using a paint mainly composed of functional powders such as conductive carbon and metal oxides, it may aggregate while floating in the tank and liquefy by the time it reaches the application part. Also, even if it reaches the application part in a floating state, since the droplets land on the substrate before being atomized into fine particles, it has been difficult to form a coating film with a uniform thickness.

[0006] Further, in the configuration of Patent Document 2, since the charge is applied to the paint inside the nozzle, it has been difficult to atomize the paint.

[0007] The present invention solves the above-mentioned conventional problems, and an object thereof is to provide a die nozzle capable of obtaining a coating film with a uniform thickness and a coating apparatus using the same.

Means for Solving the Problems

[0008] In order to achieve the above object, the die nozzle according to the present invention includes a nozzle for applying paint onto a substrate continuously running on a roll, and a liquid feeding means for supplying the paint to the nozzle. When the side where the substrate approaches the nozzle is defined as the upstream side and the side where the substrate separates from the nozzle is defined as the downstream side along the running direction of the substrate, the nozzle is composed of a first block defining an upstream nozzle and a second block defining a downstream nozzle along the running direction of the substrate, and has a charging electrode for applying a potential that forms a potential gradient between the roll and the nozzle.

[0009] The coating apparatus according to the present invention includes the above die nozzle, a roll provided at a position horizontally facing the nozzle of the die nozzle and for continuously running the substrate. and is provided with.

Effects of the Invention

[0010] As described above, according to the nozzle and the coating device according to the present invention, by separating the atomizing function and the charging function by the charging electrode, it becomes possible to uniformly apply charges in the width direction to the atomized paint. As a result, it is possible to atomize while the charged paint flies onto the base material as the object to be coated, and to control it into a coating film with a uniform thickness. Further, by installing a roll that serves as a counter electrode in the horizontal direction, large droplets can be dropped on the way, and paint droplets of uniform size can be landed on the base material as the object to be coated.

Brief Description of the Drawings

[0011]

Figure 1A

Figure 1B

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0012] The nozzle according to the first aspect includes a nozzle for applying a coating material onto a base material continuously running on a roll, and a liquid feeding means for supplying the coating material to the nozzle. When the side where the base material approaches the nozzle is defined as the upstream side and the side where the base material separates from the nozzle is defined as the downstream side, the nozzle is composed of a first block defining an upstream nozzle and a second block defining a downstream nozzle along the running direction of the base material, and has a charging electrode for applying a potential for forming a potential gradient between the roll and the nozzle.

[0013] The nozzle according to the second aspect is, in the first aspect, the first block defining the upstream nozzle has an ultrasonic element at its tip, the second block defining the downstream nozzle has a charging electrode for applying a charge at its tip, the coating material supplied from the liquid feeding means to the nozzle is atomized by ultrasonic waves by the ultrasonic element of the upstream nozzle, and the floating coating material is charged by the charging electrode of the downstream nozzle and is made to fly onto the roll serving as a counter electrode, thereby applying it onto the base material.

[0014] According to the above configuration, it becomes possible to uniformly atomize the continuously supplied coating material in the width direction.

[0015] The nozzle according to the third aspect is, in the first or second aspect, the slit gap of the slit of the nozzle may be 0.1 mm or more and 2 mm or less.

[0016] The coating apparatus according to the fourth aspect includes the nozzle according to any one of the first to third aspects, and a roll provided at a position horizontally facing the nozzle of the nozzle and continuously running the base material.

[0017] The coating apparatus according to the fifth aspect is, in the fourth aspect, the roll may have a diameter of 50 mm or more.

[0018] Hereinafter, the nozzle and the coating apparatus according to the embodiment will be described with reference to the accompanying drawings. In the drawings, substantially the same members are denoted by the same reference numerals.

[0019] (Embodiment 1) FIG. 1A is a schematic view showing the overall configuration of a coating apparatus 101 according to Embodiment 1. FIG. 1B is a schematic view showing the flying state of the paint between the nozzle 105 and the roll 111 of the coating apparatus 101 in FIG. 1A. For convenience, the coating direction of the paint is shown as the X direction, the vertically upward direction is shown as the Z direction, and the width direction of the nozzle is shown as the Y direction. In FIG. 1A, the coating apparatus 101 includes a roll 111 for continuously running a base material, a nozzle 105 for applying paint onto the base material, and a paint feeding mechanism 104. The roll 111 is arranged to face the nozzle 105 in the horizontal direction (X direction). Then, a functional paint 102 composed of a functional powder, a binder resin, and a solvent is supplied from the tank 103 to the nozzle 105 by the feeding mechanism 104. Note that the nozzle 105 and the paint feeding mechanism 104 that supplies paint to the nozzle 105 constitute a die nozzle 120. Further, as shown in FIG. 1B, when the side where the base material 112 approaches the nozzle 105 is defined as the upstream side and the side where the base material 112 separates from the nozzle 105 is defined as the downstream side, the nozzle 105 is composed of a first block that defines an upstream nozzle 106 and a second block that defines a downstream nozzle 107 along the traveling direction of the base material 112. The functional paint 102 is atomized by an ultrasonic element 109 embedded at the tip of the upstream nozzle 106 and is charged by a high voltage potential applied to a charging electrode 110 arranged at the tip of the downstream nozzle 107. The charged functional paint flies (113) from the nozzle 105 onto the base material 112 traveling on the roll 111 and lands on the base material 111 to form a coating state 114.

[0020] According to the nozzle 120 and the coating device 101 according to Embodiment 1, by separating the atomizing function and the charging function by the charging electrode 110, it becomes possible to uniformly apply charges in the width direction to the atomized paint. As a result, while the charged paint flies onto the base material 112 which is the object to be coated, it atomizes and can be controlled into a coating film with a uniform thickness. Further, by installing the roll 111 which is a counter electrode in the horizontal direction, large droplets can be dropped midway, and paint droplets of a uniform size can be made to land on the base material 112 which is the object to be coated.

[0021] <Nozzle> FIG. 2 is a perspective development view showing the configuration of the nozzle 105 in the nozzle according to Embodiment 1. The nozzle 105 includes an upstream nozzle (first block) 106, a downstream nozzle (second block) 107, and a shim 108 disposed therebetween. The manifold 115 is a groove portion provided to spread the paint supplied to the nozzle 105 to a desired coating width and discharge it uniformly. The paint whose coating width in the width direction (Y direction) is controlled by the manifold 115 and the shim 108 flows to the tip of the nozzle 105, is atomized by the ultrasonic element 109 embedded at the tip of the upstream nozzle 106, and a potential is applied by a high-voltage power supply by the charging electrode 601 disposed at the tip of the downstream nozzle 107 to charge the paint.

[0022] <Ultrasonic element> FIG. 3 is a schematic perspective view showing the configuration of the upstream nozzle 106 and the shim 108 in the nozzle according to Embodiment 1. The upstream nozzle 106 is provided with a manifold 115 for spreading the supplied paint in a desired width direction, and an ultrasonic element 401 is embedded at the tip.

[0023] FIG. 4(a) is a schematic diagram showing the configuration of the tip of the upstream nozzle 106 of the nozzle according to Embodiment 1. FIGS. 4(b) to (d) are schematic diagrams showing examples of the arrangement of the ultrasonic element 401 at the tip of the upstream nozzle 106. The ultrasonic element 401 may be embedded throughout the width direction of the upstream nozzle 106 (FIG. 4(b)), or those divided into a certain width may be evenly embedded (FIG. 4(c)), or a diaphragm 402 may be provided on the ultrasonic element 401 (FIG. 4(d)). By the ultrasonic element 401 provided at the tip of the upstream nozzle 106, the paint can be atomized evenly in the width direction. The ultrasonic element vibrates in the range of 40 kHz to 2.4 MHz. For example, it may be 48 kHz, 60 kHz, 120 kHz, or 2.4 MHz. Also, for the output, it is desirable to use it at 100 μA to 500 μA, but the frequency and output are not particularly limited. For example, it may be changed according to the solid content concentration and solvent of the functional powder contained in the paint, and the flow rate of the paint applied per unit time.

[0024] <Charging electrode> FIG. 5 is a schematic diagram showing the configuration of the downstream nozzle (second block) 107 of the nozzle according to Embodiment 1 and the charging electrode 601 arranged at the tip. As the shape of the charging electrode 601 arranged at the tip, an elongated needle shape is desirable, and those with a length of 3 to 20 mm and a diameter of 100 to 500 μm are desirable. Further, the length may be 5 to 10 mm. The electrode interval is preferably 3 to 10 mm, and the voltage to be applied is desirably from -50 kV to +50 kV. Also, the applied voltage may be, for example, 3 kV to 50 kV. Note that the length and diameter of the electrode, the electrode interval, and the voltage to be applied are not particularly limited. For example, it may be changed according to the solid content concentration and solvent of the functional powder contained in the paint, and the flow rate of the paint applied per unit time.

[0025] FIG. 6 is a schematic diagram showing the form of the charging electrode 601 arranged at the tip of the downstream nozzle 107 of Embodiment 1. The same effect can be obtained by arranging the charging electrode 601 on the integral electrode plate 602. Further, by providing the electrode plate and applying thereto, the downstream nozzle 107 does not need to be entirely made of a conductive metal, and the electric field generated between the nozzle and the roll can be locally concentrated on the charging electrode 601 and the electrode plate 602.

[0026] FIG. 7 is a conceptual diagram showing the state 113 in which the paint flies from the nozzle 105 to the roll 111. By flying the droplets of the functional paint in the horizontal direction (X direction) instead of the vertically downward (-Z direction), when the atomized droplets are large, they can fall during flight, and it is possible to avoid the situation where the paint with a large particle size is directly applied and becomes a defect. Further, during flight, the paint (ink) with a large particle size is atomized by the effect of electrostatic explosion and can be applied onto the object to be coated as fine droplets.

[0027] According to such a configuration, the paint whose coating width in the width direction is controlled by the manifold 115 and the shim 108 flows to the tip of the nozzle. Further, the paint is atomized by the ultrasonic element 109 embedded at the tip of the upstream nozzle, and a potential is applied to the paint by a high-voltage power supply by the electrode 601 arranged at the tip of the downstream nozzle 107 to charge the paint, and the paint can be made to fly toward the roll which is the counter electrode.

[0028] In addition, in this Embodiment 1, the charging electrode for applying a potential to the paint is provided by arranging it on the nozzle, but it is not limited to this. For example, an electrode different from the nozzle may be provided in the space between the nozzle and the roll to control the electric field between the nozzle and the roll and control the flight of the paint.

[0029] (Embodiment 2) FIG. 8 is a schematic diagram showing the configuration of the conductive portion 802 of the roll 111 in the coating apparatus according to Embodiment 2. In FIG. 8, by embedding a conductive member in the conductive portion 802 and combining it with the non-conductive member 803, there is an effect of selectively attaching the paint charged to the conductive portion 802. Note that since other configurations are substantially the same as those of the coating apparatus according to the first embodiment, the description thereof is omitted. According to the coating apparatus according to the second embodiment, by providing the patterned conductive portion 802 on the roll 111, it is possible to attach the paint selectively charged to the patterned conductive portion 802.

[0030] In addition, an antistatic functional film can be formed using a coating film liquid containing conductive particles on a plastic film substrate. Also, a thin functional film such as an antireflection film can be formed using a coating film liquid containing titanium oxide particles or barium titanate particles.

[0031] Note that in the present disclosure, it includes appropriately combining any of the various embodiments and / or examples described above, and the effects possessed by each embodiment and / or example can be achieved.

Industrial Applicability

[0032] The nozzle according to the present invention and the coating apparatus using the same can obtain a coating film with a uniform thickness. Therefore, for example, it is possible to form an antistatic functional film formed using a coating film liquid containing conductive particles on a plastic film substrate, an antireflection film formed using a coating film liquid containing titanium oxide particles or barium titanate particles, and a thin functional film such as a catalyst layer electrode used in a fuel cell.

Explanation of Signs

[0033] 101 Coating apparatus 102 Coating liquid 103 Tank section 104 Liquid feeding mechanism 105 Entire nozzle 106 Upstream nozzle (first block) 107 Downstream nozzle (second block) 108 Shim 109 Ultrasonic element 110 Charging electrode 111 Roll 112 Substrate 113 Atomized and flying paint 114 Paint applied on the substrate 115 Manifold 120 Nozzle 201 Overall view of the nozzle 401 Ultrasonic element 402 Diaphragm 601 Charging electrode 602 Electrode plate 701 Flying state of the nozzle, roll and atomized paint 802 Conductive part 803 Non - conductive part

Claims

1. A die nozzle comprising a nozzle for applying a coating material onto a base material continuously running on a roll, and a liquid feeding means for supplying the coating material to the nozzle, wherein when the side where the base material approaches the nozzle is defined as the upstream side and the side where the base material moves away from the nozzle is defined as the downstream side, the nozzle is composed of a first block defining an upstream nozzle and a second block defining a downstream nozzle along the running direction of the base material, and has a charging electrode for applying a potential for forming a potential gradient between the roll and the nozzle.

2. The first block defining the upstream nozzle has an ultrasonic element at its tip, the second block defining the downstream nozzle has the charging electrode for applying a charge at its tip, the coating material supplied from the liquid feeding means to the nozzle is atomized by ultrasonic waves by the ultrasonic element of the upstream nozzle, and the floating coating material is charged by the charging electrode of the downstream nozzle and then made to fly onto the roll serving as a counter electrode, thereby applying the coating material onto the base material. The die nozzle according to claim 1.

3. The die nozzle according to claim 1 or 2, wherein the slit gap of the slit of the nozzle is 0.1 mm or more and 2 mm or less.

4. A coating apparatus comprising the die nozzle according to any one of claims 1 to 3, and a roll provided at a position horizontally opposed to the nozzle of the die nozzle for continuously running the base material.

5. The coating apparatus according to claim 4, wherein the roll has a diameter of 50 mm or more. ​ ​

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