JP2015164711A - Coating device and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a coating fluid layer coated on a first surface of a base material sheet from deforming due to coating on a second surface of the base material sheet, with a small-sized and simple structure.SOLUTION: A coating device of the invention comprises: a backup roll supporting a base material sheet; a first coating head arranged to face the backup roll, and coating a first coating fluid on a first surface of the base material sheet in a state in which the base material sheet is supported by the backup roll; and a second coating head coating a second coating fluid on a second surface of the base material sheet at a position in a floating state at which the base material sheet is not supported, after coating the first coating fluid by the first coating head, the backup roll including a heating unit for drying the first coating fluid coated by the first coating head.

Description

  The present invention relates to a coating apparatus and a coating method for forming a coating layer in which a coating liquid is applied to both surfaces of a base sheet.

  As a conventional coating apparatus, for example, in Patent Document 1, a coating liquid (coating liquid) is applied to the surface of a substrate to be transported by a first coating head (die head) on a backup roll. A coating apparatus and a coating method for coating a coating liquid by a web tension method using a second coating head (die head) in a floating state without a backup roll on the back surface are disclosed. Patent Document 2 includes a first coating roll (gravure roll) that applies a coating agent (corresponding to the coating liquid of Patent Document 1) on one surface (front surface) of a substrate to be conveyed. It is dried by heating the coating agent between the coating unit and the second coating coating unit having a second coating roll (gravure roll) that coats the coating agent on the other surface (back surface). A coating apparatus having a configuration in which a dryer is provided is disclosed.

JP2012-086212A JP 2010-221204 A

  However, in the coating apparatus described in Patent Document 1, since the surface coating layer is not dried after the surface coating of the base material, the second coating head is used for the back surface coating of the base material. There is a possibility that the coating liquid flows out from the coating layer at the place pressed against the back surface. When the coating liquid flows out, the shape of the coating layer at that location is deformed, so that there is a problem that the coating layer is not stably formed. Moreover, in the coating apparatus described in Patent Document 2, as described above, a dryer for drying the coating agent by heating or the like is disposed, so that the coating apparatus is enlarged and its structure is increased. Therefore, it is insufficient in terms of simplification of the apparatus and reduction of manufacturing cost, and improvement is desired.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) One form of this invention is a coating apparatus which coats a coating liquid on both surfaces of the strip | belt-shaped base material sheet | seat conveyed continuously. The coating apparatus includes a backup roll that supports the base sheet; and a first coating head that is disposed to face the backup roll, and the base sheet is supported by the backup roll. A first coating head for coating a first coating liquid on the first surface of the base sheet; and a floating state in which the base sheet is not supported after coating by the first coating head. And a second coating head that coats a second coating liquid on the second surface of the base sheet at a certain position. The said backup roll has a heating part for drying the said 1st coating liquid coated with the said 1st coating head. In this case, the first coating liquid is applied to the first surface of the base sheet by the first coating head, and at the same time, the first coating liquid applied by heating from the backup roll. Since drying is performed, when the second coating liquid is applied to the second surface of the base sheet, the second coating head is pressed against the second surface of the base sheet. The first coating liquid can be prevented from flowing out, and the coating liquid layer can be stably formed. Further, since there is no need to provide an independent drying device, it is advantageous for downsizing the device and simplifying the structure.

(2) The coating apparatus of the said form WHEREIN: You may make it provide the conveyance belt which has a heating part in the conveyance path | route of the said base material sheet from the said backup roll to a said 2nd coating head. In this case, since the drying by the transport belt can be performed together with the drying by the backup roll, the drying of the first coating liquid can be promoted. Moreover, since each heating part can be reduced in size compared with the case where an independent drying apparatus is provided, it is advantageous to the downsizing of the apparatus and the simplification of the structure as a whole.

(3) Another embodiment of the present invention is a coating method in which a coating solution is applied to both sides of a continuously conveyed belt-like substrate sheet. In this coating method, (a) the first coating head disposed opposite to the backup roll is first on the first surface of the base sheet while the base sheet is supported by the backup roll. And (b) after applying by the first coating head, the base material sheet is in a floating state where the base material sheet is not supported by the second coating head. Applying a second coating liquid to the second surface of the sheet, and the base sheet coated with the first coating liquid is formed on the second coating head. A step of drying so that the liquid component in the coating liquid layer formed with the first coating liquid is 5 times or less the volume of the solid component before being transported to the position; In this case, in this case, when the second coating liquid is applied to the second surface of the base sheet, the second coating head is pressed against the second surface side of the base sheet. The first coating liquid can be prevented from flowing out, and the coating liquid layer can be stably formed.

(4) In the coating method of the above aspect, the drying step may be performed so that the liquid component in the coating liquid layer is twice or more the volume of the solid component. In this case, even when the second coating head is pressed against the second surface side of the base material sheet when the second coating liquid is applied to the second surface of the base material sheet, It is possible to suppress the occurrence of cracking in the coating liquid layer due to the coating liquid and to stably form the coating liquid layer.

  The present invention can also be realized in various forms other than the above-described coating apparatus and coating method. For example, the present invention can be realized in the form of a transfer apparatus and transfer method using a coating apparatus, a catalyst layer forming film manufacturing apparatus and a manufacturing method in which a catalyst layer is formed on an electrolyte film using a coating liquid as a catalyst liquid.

It is explanatory drawing which shows schematic structure of the manufacturing apparatus for manufacturing the catalyst layer forming film in which the catalyst layer was formed on the electrolyte film as 1st Embodiment. It is explanatory drawing which shows the manufacture procedure of the catalyst layer formation film in the catalyst layer formation film manufacturing apparatus of FIG. It is explanatory drawing which shows schematic structure of the manufacturing apparatus for manufacturing the catalyst layer forming film in which the catalyst layer was formed on the electrolyte film as 2nd Embodiment.

A. First embodiment:
FIG. 1 is an explanatory diagram showing a schematic configuration of a manufacturing apparatus for manufacturing a catalyst layer forming film in which a catalyst layer is formed on an electrolyte film as the first embodiment. FIG. 2 is an explanatory diagram showing a manufacturing procedure of the catalyst layer forming film in the catalyst layer forming film manufacturing apparatus of FIG. As shown in FIG. 1, the catalyst layer forming film manufacturing apparatus 10 includes a transfer catalyst layer forming unit 100 and a catalyst layer transfer unit 200. The transfer catalyst layer forming unit 100 corresponds to the coating apparatus of the present invention.

  The transfer catalyst layer forming unit 100 includes a first coating unit 110, a second coating unit 120, and a drying unit 130. The first coating unit 110 is a general die coater, and includes a backup roll 114 and a first die head 112 disposed to face the backup roll 114. The backup roll 114 supports the belt-shaped base sheet BS continuously conveyed from the base sheet unwinding roll BU on the back surface. The first die head (slot die) 112 applies the first catalyst ink to the surface (first surface) of the base sheet BS at the position supported by the backup roll 114 to form the first catalyst layer CL1. (Step S10 in FIG. 2).

  As the base sheet BS, a sheet made of a material excellent in heat resistance, acid resistance, and peelability after transfer, which will be described later, usually a sheet using a fluorine-based material typified by PTFE (polytetrafluoroethylene) is often used. The catalyst ink is a mixed liquid in which catalyst ink particles are dispersed in a solvent, and includes a state such as slurry and paste. The catalyst ink particles have a substantially spherical shape, and are formed of a catalyst particle in the center and a polymer electrolyte covering the catalyst particles. The catalyst particles are those in which a noble metal (for example, platinum or a platinum alloy) is supported on a support having electron conductivity (for example, carbon particles). As the polymer electrolyte, for example, an electrolyte of the same quality as the electrolyte constituting the electrolyte membrane is used. The electrolyte membrane is, for example, a proton conductive ion exchange membrane (PEM) formed of a solid polymer material, for example, a fluorine-based resin or a carbon-based resin. As this electrolyte membrane, for example, a Nafion membrane (manufactured by DuPont) formed of Nafion (registered trademark), which is one of fluorine resins, is often used.

  Here, the backup roll 114 is a heat roll including a heating unit 115 that heats the roll surface, and is formed while the base sheet BS is in contact with the roll surface at the same time as the first catalyst ink is applied. The first catalyst layer CL1 is heated and dried (step S20 in FIG. 2). Note that the heating temperature is 5 times the volume of the liquid component with respect to the solid component in the first catalyst layer CL1 in a dry state immediately before starting the application of the second catalyst ink by the second coating unit 120 described later. In the following, it is set to be in the range of 0 to 5 times. Preferably, it is set to be within a range of 1 to 5 times. More preferably, it is set to be in the range of 2 to 5 times. In this example, it is set to be in a range of 2 to 5 times. For example, the heating temperature is set to 80 ° C. to 120 ° C. The reason for setting the dry state in this way will be described later.

  The second coating unit 120 is a so-called kiss coater, and the support roll 122 and the second roll disposed on the back surface (second surface) side of the base sheet BS conveyed from the first coating unit 110. A die head (slot die) 124 is provided. The second coating unit 120 applies the second catalyst ink to the back surface of the base sheet BS by a web tension method. Specifically, the back surface of the base material sheet BS supported by the support roll 122 is conveyed to the back surface of the base material sheet BS by pressing the tip of the head in an off-roll state (floating state) without a backup roll. A second catalyst ink is applied to form a second catalyst layer CL2 (step S30 in FIG. 2). The second catalyst ink may be the same ink as the first catalyst ink or a different ink.

  The drying unit 130 is configured by a general drying device. The drying unit 130 sufficiently dries the first catalyst layer CL1 and the second catalyst layer CL2 formed on the base sheet BS continuously conveyed from the second coating unit 120, thereby transferring the transfer catalyst. A layer sheet CS is produced (step S40). The produced transfer catalyst layer sheet CS is continuously conveyed to the catalyst layer transfer unit 200.

  The catalyst layer transfer unit 200 includes a pair of transfer rolls 210a and 210b and a pair of peeling rolls 220a and 220b. The pair of transfer rolls 210a and 210b are arranged to face each other so as to sandwich the transfer catalyst layer sheet CS being conveyed. The first electrolyte membrane PS1 fed from the first electrolyte membrane unwinding roll PU1 is overlaid on the first catalyst layer CL1 of the transfer catalyst layer sheet CS, and the second catalyst layer CL2 is overlaid with the first electrolyte membrane PS1. The second electrolyte membrane PS2 fed from the second electrolyte membrane unwinding roll PU2 is overlapped and sandwiched between the nip portions of the pair of transfer rolls 210a and 210b. The pair of transfer rolls 210a and 210b is a heat roll having heating portions 211a and 211b, and hot presses (heats) the superimposed transfer catalyst layer sheet CS, the first electrolyte film PS1, and the second electrolyte film PS2. And pressurize). Thereby, the first catalyst layer CL1 is transferred to the first electrolyte membrane PS1, and the second catalyst layer CL2 is transferred to the second electrolyte membrane PS2 (step S50 in FIG. 2). Accordingly, the second catalyst layer is formed on the first catalyst layer forming film (CCM) CM1 and the second electrolyte film PS2 in which the first catalyst layer CL1 is formed on the first electrolyte film PS1. A second catalyst layer forming film CM2 having CL2 formed thereon is produced. The first electrolyte membrane PS1 and the second electrolyte membrane PS2 may be the same electrolyte membrane or different electrolyte membranes. The heating temperature is set to a temperature not higher than the thermal decomposition temperature of the electrolyte contained in the electrolyte membrane or the catalyst layer and not lower than the phase transition temperature of the catalyst, for example, about 130 ° C. to 150 ° C.

  The pair of peeling rolls 220a and 220b peels the first catalyst layer forming film CM1 and the second catalyst layer forming film CM2 from the base sheet BS conveyed from the pair of transfer rolls 210a and 210b (Step S60). ). The first catalyst layer forming film CM1 and the second catalyst layer forming film CM2 after peeling are wound up by the first catalyst layer forming film winding roll CW1 and the second catalyst layer forming film winding roll CW2, The material sheet BS is wound up by the base sheet winding roll BW.

  As described above, in the catalyst layer forming film manufacturing apparatus 10 of the present embodiment, the surface (first surface) of the base sheet BS that is supported by the backup roll 114 by the first die head 112 of the first coating unit 110. At the same time that the first catalyst liquid is applied (coated) to the first surface), the first catalyst layer CL1 of the first coating liquid is heated and dried by the backup roll 114. Accordingly, the second coating liquid is applied to the back surface (second surface) of the base sheet BS by the second die head 124 of the second coating unit 120 without providing a separate drying device. (Applying) Even if the second die head 124 is pressed against the second surface of the base sheet BS, the first coating liquid flows out and the first catalyst layer CL1 is deformed. This can be suppressed, and the first catalyst layer CL1 can be formed in a stable shape.

  The first coating liquid and the second coating liquid are the same, and the first catalyst layer CL1 and the second catalyst layer CL2 have the same configuration, and the first electrolyte membrane PS1 and the second electrolyte. If the membrane PS2 is configured to use the same electrolyte membrane, the catalyst layer is formed by coating and drying the catalyst solution and transferring the catalyst layer to the electrolyte membrane to form the catalyst layer forming membrane. Since the production of the catalyst layer forming film for a batch becomes possible, the production efficiency can be doubled. Also, the length of the production line can be halved compared to the case where two production lines are arranged in series, and the width of the production line is halved compared to the case where two production lines are arranged in parallel. Can be.

  Further, PTFE used as the base sheet BS is difficult to reuse due to deformation due to transfer, and generally has a high material cost. If both surfaces of the base sheet BS are used as in this embodiment, it is possible to increase the utilization efficiency of the base sheet BS and reduce the manufacturing cost.

  In addition, the dry state immediately before starting the application of the second catalyst ink by the second coating unit 120, the volume of the liquid component with respect to the solid component in the first catalyst layer CL1 is 5 times or less, that is, 0 to 0 By limiting the range to 5 times, it is possible to suppress the first catalyst layer CL1 from being deformed due to insufficient drying of the first catalyst layer CL1 and deformation of the first catalyst layer CL1. it can. In addition, it is preferable that the volume ratio of the liquid component with respect to the solid component in the first catalyst layer CL1 is within a range of 1 to 5 times in the dry state immediately before starting the application of the second catalyst ink. It is more preferable to be within a range of ˜5 times. If it does in this way, it can also suppress that a crack generate | occur | produces in 1st catalyst layer CL1 by the 2nd die head 124 being pressed.

  As can be seen from the above description, the first die head 112 and the second die head 124 correspond to the first coating head and the second coating head of the present invention.

B. Second embodiment:
FIG. 3 is an explanatory diagram showing a schematic configuration of a manufacturing apparatus for manufacturing a catalyst layer forming film in which a catalyst layer is formed on an electrolyte film as a second embodiment. The catalyst layer forming film manufacturing apparatus 10B is different in that the transfer catalyst layer forming unit 100 of the catalyst layer forming film manufacturing apparatus 10 (FIG. 1) of the first embodiment is replaced with a transfer catalyst layer forming unit 100B. . The transfer catalyst layer forming unit 100B uses the second coating unit 120 of the transfer catalyst layer forming unit 100 as a second coating unit 120B in which the support roll 122 is omitted, and the first coating unit 110 and the first coating unit 120B. A conveyance belt 116 is provided on the conveyance path between the two coating units 120B.

  The conveyor belt 116 is a heat belt having a heating unit 117, and heat-drys the first catalyst layer CL1 in addition to heat-drying the first catalyst layer CL1 by the backup roll 114. As described in the first embodiment, the heating temperature is the dry state immediately before starting the application of the second catalyst ink by the second coating unit 120 by the drying by the backup roll 114 and the conveyor belt 116. The volume of the liquid component with respect to the solid component in one catalyst layer CL1 is set within a range of 0 to 5 times. Preferably, it is set to be within a range of 1 to 5 times. More preferably, it is set to be in the range of 2 to 5 times. For example, the heating temperature of the backup roll 114 may be set to 80 ° C., and the heating temperature of the conveyor belt 116 may be set to 110 ° C.

  In the present embodiment, the drying of the first catalyst layer CL can be promoted by executing the heating and drying by the conveying belt in addition to the heating and drying of the backup roll 114. In addition, according to the two-stage heating and drying by the backup roll 114 and the conveyor belt 116, each heating unit can be reduced in size. It is advantageous for making it easier and easier.

C. Variation:
In the above-described embodiment, the case where the coating apparatus of the present invention is applied to the transfer catalyst layer preparation unit of the catalyst layer forming film manufacturing apparatus has been described as an example. It is possible to apply the coating liquid to both sides of the base sheet, and to apply the coating liquid to form a coating liquid layer on both sides of the base sheet.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. Moreover, elements other than the elements described in the independent claims among the constituent elements in the above-described embodiments and modifications are additional elements and can be omitted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Catalyst layer forming film manufacturing apparatus 10B ... Catalyst layer forming film manufacturing apparatus 100 ... Catalyst layer preparation part 110 ... Coating part 112 ... Die head 114 ... Backup roll 115 ... Heating part 116 ... Conveying belt 117 ... Heating part 120 ... Coating Part 122 ... Support roll 124 ... Die head 130 ... Drying part 200 ... Catalyst layer transfer part 210a, 210b ... Transfer roll 211a, 211b ... Heating part 220a, 220b ... Peeling roll BS ... Base sheet CS ... Transfer catalyst layer sheet BU ... Base sheet winding roll BW ... Base sheet winding roll CL1 ... Catalyst layer CL2 ... Catalyst layer CM1 ... Catalyst layer forming film CM2 ... Catalyst layer forming film PS1 ... Electrolyte film PS2 ... Electrolyte film PU1 ... Electrolyte film unwinding roll PU2 ... electrolyte film unwinding roll CW1 ... catalyst layer forming film winding roll C 2 ... catalyst layer forming film take-up roll

Claims (4)

A coating apparatus that coats the coating liquid on both sides of a belt-like substrate sheet that is continuously conveyed,
A backup roll for supporting the base sheet;
A first coating head disposed opposite to the backup roll, wherein the first coating liquid is applied to the first surface of the base sheet in a state where the base sheet is supported by the backup roll. A first coating head to be worked;
A second coating for coating a second coating liquid on the second surface of the base sheet at a position where the base sheet is in a floating state where the base sheet is not supported after coating by the first coating head. Engineering head,
With
The said backup roll has a heating part for drying the said 1st coating liquid coated with the said 1st coating head. The coating device characterized by the above-mentioned. A coating apparatus according to claim 1,
A coating apparatus comprising: a transport belt having a heating unit in a transport path of the base sheet from the backup roll to the second coating head. It is a coating method for coating a coating liquid on both sides of a belt-like substrate sheet that is continuously conveyed,
(A) The first coating liquid is applied to the first surface of the base sheet in a state where the base sheet is supported by the backup roll by the first coating head disposed opposite to the backup roll. Process to work,
(B) A second coating is applied to the second surface of the base sheet by the second coating head in a floating state where the base sheet is not supported after coating by the first coating head. A process of applying the working fluid;
In addition,
By the time the said base material sheet | seat with which the said 1st coating liquid was coated is conveyed to the position of a said 2nd coating head, in the coating liquid layer formed with the said 1st coating liquid A coating method comprising a step of drying so that the liquid component is 5 times or less the volume of the solid component. The coating method according to claim 3,
The said drying process dries so that the liquid component in the said coating liquid layer may become 2 times or more of the volume of a solid component. The coating method characterized by the above-mentioned.

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