TW202144083A - Coating device, film production system, and film production method - Google Patents

Abstract

A bar coater is provided with a bar and a blower. The bar coats a substrate with a coating solution. The bar extends in the axial direction orthogonal to the flow direction of the substrate. An accumulation of liquid in which the coating solution is accumulated is formed between the bar and the substrate upstream of the bar in the flow direction. The blower applies pressure to a contact part of the substrate at which the substrate contacts the accumulation of liquid.

Description

Coating apparatus, film manufacturing system, and film manufacturing method

The present invention relates to a coating apparatus, a film manufacturing system, and a film manufacturing method.

Conventionally, a bar coater is known as a coating apparatus for coating a coating liquid on the surface of a resin substrate (for example, refer to Patent Document 1). prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2019-115878

The problem to be solved by the invention In the case of the coating apparatus described in the above-mentioned Patent Document 1, the coating liquid containing air bubbles may be coated on the substrate.

The present invention provides a coating apparatus capable of suppressing application of a coating solution containing bubbles to a substrate, a film manufacturing system, and a film manufacturing method.

means of solving problems The present invention [1] includes an application device including an application member for applying a coating liquid to a substrate, the application member extending in an axial direction orthogonal to the traveling direction of the substrate , and on the upstream side of the coating member in the traveling direction, an accumulation liquid formed by accumulating the coating liquid is formed between the coating member and the base material; and a pressing device is used to press the base material. The contact part that comes into contact with the aforementioned accumulated liquid.

According to the above configuration, when air bubbles are contained in the accumulating liquid, the air bubbles can be squeezed out from the accumulating liquid by pressing the contact portion by the pressing means.

Thereby, the coating liquid containing air bubbles can be suppressed from being applied to the base material.

The present invention [2] includes the coating device according to the above-mentioned [1], wherein the pressing means presses the contact portion by causing an air flow to act on the contact portion.

According to the above configuration, the pressing means can press the contact portion without coming into contact with the contact portion.

Thereby, the friction between the base material and the pressing member can be suppressed, and the appearance defects due to damage to the base material can be reduced.

The present invention [3] includes the coating device according to the above [2], wherein the pressing device has a nozzle for blowing the airflow toward the contact portion.

The present invention [4] includes the coating device according to the above [3], wherein the nozzle is movable in the axial direction.

According to the above-described configuration, by moving the nozzle in the axial direction while the nozzle is blowing out the airflow, the air bubbles in the accumulated liquid can be squeezed out in the axial direction.

The present invention [5] includes the coating device according to any one of the above [1] to [4], wherein the coating member is a roller.

The present invention [6] includes a film manufacturing system comprising: an extrusion forming device for extruding a base material; and a coating device for coating as described in any one of the above [1] to [5] A device for applying a coating liquid to the substrate; and an extending device for extending the substrate on which the coating liquid is applied.

According to the above-described configuration, since the above-described coating device is provided, the coating liquid containing air bubbles can be suppressed from being coated on the substrate.

As a result, the yield of the thin film can be improved.

The present invention [7] includes a method for producing a film, which includes the following steps: an extrusion forming step, which is to extrude a base material; and a coating step, which utilizes any one of the above [1] to [5]. a coating device for coating the coating liquid on the substrate extruded through the extrusion forming step; and an extension step for applying the coating liquid to the substrate through the coating step material to be extended.

According to this method, since the coating liquid can be applied to the base material by the above-mentioned coating apparatus, the application of the coating liquid containing air bubbles to the base material can be suppressed.

As a result, the yield of the thin film can be improved.

Invention effect According to the coating apparatus, the manufacturing system of a thin film, and the manufacturing method of a thin film of this invention, it can suppress that the coating liquid containing a bubble is apply|coated to a base material.

1. Film manufacturing system The manufacturing system 1 of the thin film F is demonstrated.

As shown in FIG. 1 , the thin film F includes a base material S and a coating film C. As shown in FIG. The base material S has a first surface S1 and a second surface S2 in the thickness direction of the base material S. As shown in FIG. The film C is arranged on the first surface S1 of the substrate S. The film C covers the first surface S1 of the substrate S. The film C may also be an easily adhesive layer. When the coating film C is an easily bonding layer, the film F is an easily bonding film. The easy-to-bond film is, for example, a polarizer used in image display devices such as mobile devices, car navigation devices, personal computer screens, and televisions. Specifically, the easily adhesive film is used as a protective film for protecting the polarizer of a polarizing plate. The easily adhesive film is bonded to the polarizer through the adhesive layer. The easily bonding film is bonded to the polarizer using the easily bonding layer.

As shown in FIG. 2, the production system 1 of the film F includes: an extrusion forming apparatus 2, a first stretching apparatus 4A, a bar coater 3 as an example of a coating apparatus, a second stretching apparatus 4B as an example of the stretching apparatus, The cutting processing device 5 , the knurling processing device 6 , and the winding device 7 are provided.

(1) Extrusion forming device The extrusion forming apparatus 2 is used to extrude the base material S (extrusion forming step). The substrate S extruded from the extrusion forming apparatus 2 has a sheet shape.

The base material S is made of thermoplastic resin. Examples of thermoplastic resins include acrylic resins, polyolefin resins, cyclic polyolefin resins, polyester resins, polycarbonate resins, polystyrene resins, polyamide resins, polyimide resins, acetate resins (diacetic acid cellulose, cellulose triacetate, etc.), etc.

In the manufacture of an easy-to-bond film used as a protective film of a polarizer, the material of the substrate S is preferably an acrylic resin.

In addition, when producing an easily adhesive film used as a protective film of a polarizer, the acrylic resin may be an acrylic resin having a glutaric anhydride structure or an acrylic resin having a lactone ring structure. Acrylic resins with a glutaric anhydride structure and acrylic resins with a lactone ring structure have high heat resistance, high transparency, and high mechanical strength, and are therefore suitable for producing polarizing plates with high degrees of polarization and excellent durability. Acrylic resins having a glutaric anhydride structure are described in Japanese Patent Laid-Open No. 2006-283013, Japanese Patent Laid-Open No. 2006-335902, and Japanese Patent Laid-Open No. 2006-274118. Acrylic resins having a lactone ring structure are described in Japanese Patent Laid-Open No. 2000-230016, Japanese Patent Laid-Open No. 2001-151814, Japanese Patent Laid-Open No. 2002-120326, Japanese Patent Laid-Open No. 2002-254544, In Japanese Patent Laid-Open No. 2005-146084.

In addition, the base material S may contain other thermoplastic resins other than the acrylic resin in addition to the acrylic resin. By containing other thermoplastic resins, the birefringence of the acrylic resin can be eliminated to obtain an easy-bonding film with excellent optical isotropy. Moreover, the mechanical strength of the easy-to-bond film can also be improved.

In addition, the substrate S may also contain additives such as antioxidants, stabilizers, reinforcing materials, ultraviolet absorbers, flame retardants, antistatic agents, colorants, fillers, plasticizers, lubricants, and fillers.

(2) The first extension device The first stretching device 4A extends the base material S obtained by the extrusion forming step in the traveling direction MD of the base material S after heating (first stretching step).

(3) Bar coater The bar coater 3 applies the coating liquid to the first surface S1 of the base material S extruded through the extrusion step (coating step). In addition, on the first surface S1 of the substrate S, surface treatments such as corona treatment and plasma treatment may also be performed after the extrusion forming step and before the coating step.

The coating liquid is an easily bonding composition for forming an easily bonding layer when producing an easily bonding film.

The easy-bond layer contains a binder resin and fine particles.

As a binder resin, thermosetting resins, such as a urethane resin and an epoxy resin, are mentioned, for example, and thermoplastic resins, such as an acrylic resin and a polyester resin, are mentioned, for example. When the easy-adhesive film is used as a protective film for the polarizer, the adhesive resin is preferably a thermosetting resin. A plurality of binder resins can be used in combination.

Examples of fine particles include oxides such as silicon oxide (silica), titanium oxide (titania), aluminum oxide (alumina), and zirconia (zirconia); examples thereof include carbonates such as calcium carbonate; examples include calcium silicate, aluminum silicate, etc. , silicates such as magnesium silicate; for example, silicate minerals such as talc and kaolin; for example, phosphates such as calcium phosphate and the like. When the easy-adhesive film is used as a protective film for the polarizer, the fine particles are preferably oxide, preferably silicon oxide. A plurality of fine particles can be used in combination.

The coating liquid (easy-bonding composition) contains a resin component, the above-mentioned fine particles, and a dispersion medium.

The resin component forms the film (easy-bonding layer) of the above-mentioned binder resin by the stretching step described later. When the binder resin is a urethane resin, the resin component includes, for example, a water-based urethane resin. Examples of the water-based urethane resin include non-reactive water-based urethane resins which are emulsions of urethane resins, and examples include emulsions of urethane resins in which isocyanate groups are protected with a blocking agent. Reactive water-based urethane resin, etc. When the binder resin is a urethane resin, the coating liquid may contain a urethane curing catalyst (triethylamine, etc.) and an isocyanate monomer.

Examples of the dispersion medium include water; examples thereof include alcohols such as methanol and ethanol; and examples thereof include ketones such as acetone and methyl ethyl ketone.

(4) Second extension device The second stretching device 4B dries the coating liquid coated in the coating step. Thereby, the coating liquid becomes the coating film C described above. And the 2nd extending|stretching apparatus 4B draws the base material S on which the coating film C is formed in the width direction TD of the base material S after heating (2nd extending|stretching process). The width direction TD is orthogonal to the traveling direction MD. By the second stretching step, the substrate S on which the coating film C is formed is stretched, and the above-mentioned thin film F can be obtained.

(5) Cutting processing device The cutting device 5 cuts the film F stretched by the stretching step into a predetermined width (cutting step).

(6) Knurling processing device The knurling forming processing apparatus 6 forms knurling at both ends in the width direction of the film F cut into a predetermined width by the cutting step (knurling forming step). The knurling is formed by laser. Knurling can also be formed by heated embossing rolls.

(7) Coiling device The take-up device 7 takes up the film F having the knurling formed in the knurling step (winding-up step). By completing the winding step, a roll of the film F can be obtained.

2. Details of the rod coater As shown in FIG. 3 , the bar coater 3 includes a roller 11 as an example of a coating member, a manifold block 12, and a blower 13 as an example of a pressing device.

(1) Roller The roller 11 applies the coating liquid to the substrate S in the above-mentioned coating step. The rollers 11 extend in the axial direction. The axial direction is the same direction as the width direction TD of the substrate S. That is, the axial direction is orthogonal to the advancing direction MD of the base material S. As shown in FIG. The roller bar 11 is arranged on the upper end of the bar coater 3 . In other words, the roller bar 11 is arranged at one end of the bar coater 3 in the orthogonal direction to both the axial direction and the advancing direction MD. The roller 11 has a cylindrical shape.

As the rolling rod 11, for example, a wire rod having a wire wound around a shaft can be mentioned; The wire rods form grooves between the wires in the axial direction.

The rolling rod 11 can also be subjected to surface treatment such as chrome plating, diamond-like carbon coating, and the like. When the coating liquid contains the above-mentioned fine particles, the roller rod 11 is preferably coated with diamond-like carbon from the viewpoint of improving the wear resistance.

The rollers 11 are rotated in the forward direction with respect to the traveling direction MD (see arrows in FIG. 3 ). The peripheral speed of the roller 11 is slower than the conveying speed of the substrate S. Thereby, when the substrate S is conveyed in the traveling direction MD and the roller 11 is rotating, a coating liquid is formed between the roller 11 and the substrate S on the upstream side of the roller 11 in the traveling direction MD. The accumulated liquid L. A portion of the base material S that is in contact with the accumulated liquid L is defined as a contact portion P. The contact portion P has an upstream end E1 and a downstream end E2 in the traveling direction MD. The upstream end E1 is away from the roller bar 11 in the traveling direction MD. The downstream end E2 is in contact with the rolling rod 11 .

(2) Manifold block The manifold block 12 is arranged below the roller bar 11 . In a state where the bar coater 3 is applying the coating liquid to the substrate S, the manifold block 12 is disposed on the opposite side of the roller bar 11 with respect to the substrate S in the orthogonal direction. The manifold block 12 supports the rollers 11 . The manifold block 12 extends in the axial direction and the orthogonal direction. The manifold block 12 has a manifold 121 , a discharge port 122 and a flow path 123 .

(2-1) Manifold The manifold 121 is disposed away from the rollers 11 in the orthogonal direction. The manifold 121 accumulates the coating liquid.

(2-2) Discharge port The discharge port 122 is arranged at one end portion in the orthogonal direction of the manifold block 12 . The discharge port 122 is arranged on the upstream side of the roller 11 in the traveling direction MD. The discharge port 122 discharges the coating liquid. The coating liquid discharged from the discharge port 122 is applied to the substrate S by the rotation of the roller 11 .

(2-3) Flow path The flow path 123 is arranged between the manifold 121 and the discharge port 122 in the orthogonal direction. The flow path 123 connects the manifold 121 and the discharge port 122 . The coating liquid in the manifold 121 is discharged from the discharge port 122 through the flow path 123 .

(3) Blower The blower 13 causes the air flow to act on the contact portion P while the bar coater 3 is applying the coating liquid to the substrate S. In other words, the blower 13 causes the air flow to act on the contact portion P in a state in which the substrate S is conveyed in the traveling direction MD and the rollers 11 are rotating. The blower 13 acts on the contact portion P from the opposite side of the roller 11 with respect to the substrate S in the orthogonal direction. When the air flow acts on the contact portion P, the contact portion P is pressed by the air flow, and then bends in the direction of approaching the rolling rod 11 in the orthogonal direction. That is, the blower 13 presses the contact portion P. Thereby, when air bubbles are contained in the accumulation liquid L, the air bubbles can be extruded from the accumulation liquid L. By squeezing out the air bubbles from the accumulation liquid L, the coating liquid containing the air bubbles can be suppressed from being applied to the substrate S. As a result, coating defects due to air bubbles in the coating liquid can be suppressed. The blower 13 presses the contact portion P without contacting the contact portion P. As shown in FIG. By pressing the contact portion P without contacting the contact portion P, the friction between the substrate S and the blower 13 can be suppressed, and the appearance defect due to damage to the substrate S can be reduced. Specifically, the blower 13 includes a compressor 131 and a nozzle 132 .

(3-1) Compressor The compressor 131 is connected to the nozzle 132 through piping. The compressor 131 delivers compressed air to the nozzle 132 .

(3-2) Nozzle The nozzle 132 is arranged on the opposite side of the roller 11 with respect to the substrate S in the orthogonal direction. The nozzle 132 is arranged on the opposite side of the discharge port 122 with respect to the substrate S in the orthogonal direction. The nozzle 132 blows the compressed air from the compressor 131 toward the contact portion P. Thereby, the nozzle 132 blows the air flow toward the contact portion P. As shown in FIG. The airflow (compressed air) blown from the nozzle 132 acts on the contact portion P. As shown in FIG. Preferably, the nozzle 132 causes the air flow to act between the upstream end E1 and the downstream end E2 of the contact portion P in the travel direction MD in a way that is stronger than the upstream end E1 in the travel direction MD of the contact portion P. Preferably, the nozzle 132 causes the air flow to act on the center of the contact portion P in the travel direction MD in a way that is stronger than the upstream end E1 of the contact portion P in the travel direction MD. Thereby, the blower 13 presses the center of the contact portion P in the travel direction MD in a stronger manner than the upstream end E1 of the contact portion P in the travel direction MD. Thereby, the air bubbles in the accumulating liquid L can be approached in the direction away from the roller 11 in the traveling direction MD (the upstream direction in the traveling direction MD).

In this embodiment, the nozzle 132 can be moved in the axial direction while blowing out the airflow. Thereby, the air bubbles in the accumulated liquid L can be squeezed out in the axial direction. The nozzle 132 can move back and forth between one end and the other end of the substrate S in the axial direction. Thereby, the air bubbles can be squeezed out from all the accumulated liquid L in the axial direction.

3. Variations (1) The nozzle 132 may not move.

For example, the nozzle 132 may also extend in the axial direction, and make the air flow act on the entire contact portion P in the axial direction. The nozzle 132 can also swing in the axial direction.

In addition, the blower 13 may have a plurality of nozzles 132 . A plurality of nozzles 132 may be arranged in the axial direction. Each of the plurality of nozzles 132 can also blow out airflow in sequence along the axial direction.

In addition, the blower 13 may have one nozzle 132. One nozzle 132 may be arranged in the center of the roller 11 in the axial direction. One nozzle 132 may blow the air flow so as to move the air bubbles in the accumulating liquid L to both ends in the axial direction.

(2) The pressing device may also be in contact with the contact portion P to press the contact portion P. Specifically, as shown in FIG. 4 , the pressing device may also have a roller 21 in contact with the contact portion P. As shown in FIG. The rollers 21 extend in the axial direction. In addition, the pressing device may have a ball which is in contact with the contact portion P. As shown in FIG. The ball can also move in the axial direction.

(3) The use of the bar coater 3 is not limited to extrusion molding. For example, the base material S may be released from the coil of the base material S, and the coating liquid may be applied to the released base material S by the bar coater 3 .

(4) The coating device is not limited to the bar coater 3 . For example, the coating apparatus includes a gravure coater and a contact coater.

(5) The coating device, as shown in FIG. 5 , may be provided with a disk 31 for accumulating the coating liquid instead of the manifold block 12 .

(6) The manufacturing system 1 of the film F may not include the first stretching device 4A. The base material S to which the coating liquid is applied may be extended in the traveling direction MD and the width direction TD by the second extending device 4B (biaxial simultaneous extension). The manufacturing system 1 of the film F may not extend the substrate S. That is, the manufacturing system 1 of the film F may not include the first stretching device 4A and the second stretching device 4B.

(7) The manufacturing system 1 of the film F may also be provided with a masking film releasing device and a laminating device, instead of the knurling forming processing device 6, the masking film releasing device is one that releases the masking film, and the laminating device is a The released masking film is attached to the film F. In addition, although the above-mentioned invention provides the embodiment as an example of this invention, it is only an illustration, and should not be construed as a limitation. It will be apparent to those skilled in the art that modifications of the present invention are included in the scope of the patent application described later. industrial availability The coating apparatus, the manufacturing system of a thin film, and the manufacturing method of a thin film of this invention are utilized for manufacturing thin films, such as an easily bonding film.

1: Manufacturing system 2: Extrusion forming device 3: Bar coater 4A: 1st extension device 4B: 2nd extension device 5: Cutting and processing device 6: Knurling processing device 7: Coiling device 11: Roller 12: Manifold block 13: Blower 21: Roller 31: Plates 121: Manifold 122: Spit out 123: Flow Path 131: Compressor 132: Nozzle C: film E1: The upstream end of the contact part E2: Downstream end of contact part F: film L: accumulating fluid MD: direction of travel S: Substrate S1: The first side of the substrate S2: The second side of the substrate TD: width direction P: Contact part

FIG. 1 is a cross-sectional view of a film produced by a film production system as an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a thin film manufacturing system. FIG. 3 is an explanatory diagram for explaining the bar coater shown in FIG. 2 . It is explanatory drawing for demonstrating the 1st modification of the bar coater. FIG. 5 is an explanatory diagram for explaining a second modification of the bar coater.

11: Roller

12: Manifold block

13: Blower

121: Manifold

122: Spit out

123: Flow Path

131: Compressor

132: Nozzle

E1: The upstream end of the contact part

E2: Downstream end of contact part

L: accumulating fluid

S: Substrate

P: Contact part

Claims (7)

A coating device is characterized in that it has: An application member for applying a coating liquid to a substrate, the application member extending in an axial direction orthogonal to the advancing direction of the substrate and upstream of the application member in the advancing direction On the side, a liquid accumulation formed by accumulating the coating liquid will be formed between the coating member and the base material; and The pressing device is a device that presses the contact portion of the base material that is in contact with the accumulated liquid. The coating device of claim 1, wherein the pressing means presses the contact portion by causing an air flow to act on the contact portion. The coating device according to claim 2, wherein the pressing device has a nozzle for blowing the airflow toward the contact portion. The coating apparatus of claim 3, wherein the nozzle is movable in the axial direction. The coating device according to any one of claims 1 to 4, wherein the aforementioned coating member is a roller. A film manufacturing system is characterized by having: Extrusion forming devices, which are those that extrude substrates; A coating device, which is the coating device according to any one of claims 1 to 5, which applies a coating liquid to the aforementioned substrate; and The stretching device is used to stretch the substrate coated with the coating liquid. A method of manufacturing a thin film, comprising the following steps: The extrusion forming step is to extrude the base material; The coating step is to use the coating device according to any one of claims 1 to 5 to apply the coating solution to the substrate extruded by the extrusion step; and In the extending step, the aforementioned substrate coated with the aforementioned coating liquid through the aforementioned coating step is extended.

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