JPH11329454A - Porous gas-diffusion electrode for phosphoric-acid fuel cell, its manufacture and manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous gas-diffusion electrode for a phosphoric-acid fuel cell, having the seal of improved quality on a porous substrate end and capable of corresponding with both low volume production and high volume production, and its manufacturing method as well as its manufacturing device. SOLUTION: In a first process, a first synthetic resin sheet 4 is bonded by thermocompression to a side surface and front and back surfaces of an end paralleling a gas passage of a porous gas-diffusion electrode of a phosphoric-acid fuel cell, and, in a second process, second and third synthetic resin sheets are bonded by thermocompression to the front and back surfaces, respectively, of the end of the porous electrode 1 by interposing them between two parallel hot-press members and the first to third synthetic resin sheets 10 are impregnated into and absorbed by the porous electrode 1, and thereby the front and back surfaces of the end of the porous electrode 1 are given flat shapes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous gas diffusion electrode for a phosphoric acid fuel cell, a method and an apparatus for manufacturing the same, and more particularly to a porous electrode end.

[0002]

2. Description of the Related Art A phosphoric acid type fuel cell body is a device for obtaining DC power by electrochemically reacting hydrogen obtained by reforming fuel with oxygen in air using phosphoric acid as an electrolyte. As shown in FIG. 13, this is an aggregate of two electrodes 11 each formed of a porous substrate and an electrolyte plate 12 interposed therebetween, each having a single cell and stacked with a separate plate interposed therebetween. It is necessary to use several layers of these aggregates. At this time, the stacked electrodes 11
Are stacked so that their directions cross each other with the other reaction gas supply passages provided above or below. Therefore, one reactant gas flowing through one reactant gas supply passage, for example, hydrogen gas and another gas flowing above or below the gas supply passage, such as air, do not mix with each other, so that each supply passage Some care must be taken to seal the side edges of the parallel substrates from different gases and to maintain electrical insulation. As a sealing method, a synthetic resin film is press-bonded and thermo-compressed. For example, FIG. 12 shows a manufacturing method showing a conventional end sealing method disclosed in JP-A-59-205164. In the figure, 1 is a porous substrate forming a gas diffusion electrode, 4 is a film of a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, 24 is a fluorine oil release agent, 20 is a gas flow path of the porous substrate, 21 Is a male type and 22 is a female type.

Next, the operation will be described. 0.1m thick
A m-0.2 mm film-shaped copolymer 4 is placed on the end surface of the porous body 1 in a U-shape in cross section, and this is placed in a female mold 22 of a mold to which a fluorine oil release agent 24 has been previously applied. Then, thermocompression bonding is performed in the directions of arrows A and B by a male mold to which the release agent 24 is applied. Actually about 20-40 kg / cm ²
Heat to 340 to 380 ° C for 15 to 30 minutes while applying a surface pressure, and then anneal at a temperature of 80 to 90 ° C for about 1 hour to press the copolymer into the porous body to form a good seal. Let it. (Hereinafter referred to as known technology)

[0004]

In the prior art, for example, when performing thermocompression bonding of a porous substrate having a size of 500 mm × 1000 mm, the size of the mold must be equal to or larger than that of the porous substrate, and Equipment for pressurizing the end face of the porous substrate from the side is also required. Further, since a heating step is required, it is necessary to incorporate a heater or the like. Therefore, it becomes a large-sized facility, which requires a large capital investment and makes maintenance difficult.

In the prior art, when a 0.1-mm-thick copolymer is thermocompressed, a set of a copolymer 4 is required in a female mold, but the sheet is about 0.1-0.2 mm in width, about 30 mm in width and about 30 mm in length. Must be the same length as the length of the porous substrate, and 1000 mm
If the length is extended, deflection occurs and positioning is difficult. A large amount of capital investment is required to secure a manufacturing method that takes these points into consideration.

[0006] In the prior art, a single weight is replaced with a female mold 22.
And a male mold 21 for crimping with a U-shaped molding die. At this time, the weight 4 flows into the gap between the female mold 22 and the male mold 21 to generate burrs. When the cells are combined, the burrs cause the adhesion between the cells to be impaired, thereby deteriorating the sealing performance.

[0007] In the known art, a structure is used in which sealing is performed with a single copolymer film. The thickness of the copolymer film is 0.1 m
Since a material as thin as m is used, seal breakage occurs at the time of thermocompression bonding, leading to poor sealing.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is intended to improve the quality of a porous base end seal and to realize a porous gas of a phosphoric acid type fuel cell which can cope with a small quantity to a mass production. It is an object to provide a diffusion electrode, a method for manufacturing the same, and a manufacturing apparatus.

[0009]

According to the first aspect of the present invention, a porous gas diffusion electrode of a phosphoric acid fuel cell according to the first aspect of the present invention has an end parallel to a gas flow path of the porous gas diffusion electrode of the phosphoric acid fuel cell. Is subjected to a first step of thermocompression bonding a first synthetic resin sheet to the side and front and back surfaces of the porous electrode. By performing a second step in which the first to third synthetic resin sheets are impregnated into the porous electrode and absorbed by being subjected to thermocompression bonding while being sandwiched between heating press members, the front and rear end portions of the porous electrode Has a flat shape.

Further, according to a second aspect of the present invention, there is provided a method for manufacturing a porous gas diffusion electrode of a phosphoric acid type fuel cell, comprising: A first step of thermocompression bonding a first synthetic resin sheet to the side surface and the front and back surfaces is performed, and a second and third synthetic resin sheets are placed on two sides of the front and back surfaces of the porous electrode, respectively. By performing a second step in which the first to third synthetic resin sheets are impregnated in the porous electrode and absorbed by being pressed between the press members and thermocompression-bonded, the front and rear ends of the porous electrode are It has a flat shape.

Further, according to the method for manufacturing a porous gas diffusion electrode of a phosphoric acid fuel cell according to the third configuration of the present invention, there is provided a method for manufacturing a porous gas diffusion electrode according to the second configuration, comprising: The thickness of the sheet to be thermocompression-bonded is larger than the thickness of the sheet to be thermocompression-bonded to the front and back surfaces of the porous substrate.

Further, according to a fourth aspect of the present invention, there is provided a method for manufacturing a porous gas diffusion electrode for a phosphoric acid type fuel cell according to the second aspect, wherein the porous substrate is provided in the second step and in the first step. The first and second synthetic resin sheets thermocompression-bonded to the front and back surfaces of the ends are provided with a step of partially temporarily fixing the second and third synthetic resin sheets.

Further, according to a fifth aspect of the present invention, there is provided an apparatus for manufacturing a porous gas diffusion electrode of a phosphoric acid fuel cell, comprising an end parallel to a gas flow path of the porous gas diffusion electrode of the phosphoric acid fuel cell. Means for performing a first step of thermocompression bonding a first synthetic resin sheet on the side surface and the front and back surfaces, and applying second and third synthetic resin sheets in parallel to the front and back surfaces of the porous electrode end, respectively. Thermocompression bonding between two heating press members, the first
Means for performing a second step of impregnating and absorbing the third synthetic resin sheet into the porous electrode to make the end surface of the porous electrode flat. .

Further, according to a sixth aspect of the present invention, in the apparatus for manufacturing a porous gas diffusion electrode of a phosphoric acid fuel cell according to the sixth aspect, in the fifth aspect, a synthetic resin sheet is provided on the front and back surfaces and side surfaces of the porous substrate. In pressing, the porous substrate is heated, and a synthetic resin sheet is sequentially supplied from one corner to the other end of the end surface of the porous substrate, and the sheet is pressed to the porous substrate by the pressing means. It is provided with.

Further, according to the seventh aspect of the present invention, in the apparatus for manufacturing a porous gas diffusion electrode of a phosphoric acid type fuel cell according to the fifth aspect, in the fifth aspect, the flanged guide for regulating the position of the synthetic resin sheet in the width direction is provided. It is provided with a pressure roller for pressing the roller and the synthetic resin sheet to the side surface of the end of the porous substrate.

Further, according to an eighth aspect of the present invention, in the device for manufacturing a porous gas diffusion electrode of a phosphoric acid type fuel cell according to the eighth aspect, in the fifth aspect, the porous substrate is heated and the one corner of the porous substrate is heated. Means for sequentially feeding the synthetic resin sheet to the other corner from the other and simultaneously pressing the sheet to the side surface and the front and back surfaces of the end of the porous substrate by means of a flanged pressure roller which bends the sheet in a U-shape. is there.

According to a ninth aspect of the present invention, in the apparatus for manufacturing a porous gas diffusion electrode of a phosphoric acid fuel cell according to the ninth aspect, in the fifth aspect, the pressure roller comprises three rollers, each of which is made of a synthetic resin sheet. It is provided with a means for pressure-bonding to the front, back, and side surfaces of the porous substrate end.

Further, the apparatus for manufacturing a porous gas diffusion electrode of a phosphoric acid type fuel cell according to the tenth structure of the present invention comprises
Wherein, when thermocompression bonding of a synthetic resin sheet to the side surface of the porous substrate, means for heating the porous substrate and pressing the vacuum-adsorbed and positioned sheet to the side surface of the porous substrate are provided. It is.

An apparatus for manufacturing a porous gas diffusion electrode of a phosphoric acid type fuel cell according to the eleventh configuration of the present invention comprises:
In the configuration described above, the synthetic resin sheet is formed into a U-shape by a mold block having a suction portion for heating the porous substrate and vacuum-sucking the synthetic resin sheet, and a slide portion that slides using the suction portion as a guide. It is provided with a means for bending upward and pressing the porous substrate to the side surface and the front and back surfaces.

Further, according to a twelfth aspect of the present invention, there is provided an apparatus for manufacturing a porous gas diffusion electrode for a phosphoric acid type fuel cell, wherein a suction section for vacuum-sucking a synthetic resin sheet and a slide which slides using the suction section as a guide. Means for bending a synthetic resin sheet into a U-shape by means of a mold block having two rotating portions that are rotated by being pressed by the sliding portion and pressing the side surfaces and the front and back surfaces of the porous substrate. Things.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a main part showing a state where a synthetic resin sheet is thermocompression-bonded to a porous substrate. In the figure, 1 is an electrode made of a porous substrate, 4 is a sheet made of a synthetic resin such as a fluororesin, which is thermocompression-bonded to the side surface of the end parallel to the gas flow path of the porous substrate, 10
(10a, 10b) are synthetic resin sheets pressed on the front and back surfaces of the end portions of the porous substrate 1 in a later step.

Next, the operation will be described. After heating the porous substrate 1 to a predetermined temperature in the first step, the synthetic resin sheet 4 is pressure-bonded to the side surface by a pressure-bonding means from the side surface. In the second step, after the synthetic resin sheet 4 is press-bonded to the side surface of the end of the porous substrate in advance, the synthetic resin sheet 10 is processed to a predetermined thickness, a predetermined width and a length on the front and back surfaces, After the substrate is heated to a predetermined temperature, it is pressed from the front and back. The synthetic resin sheet used in the first step and the synthetic resin sheet used in the second step are fused together in the second step.

Next, the operation will be described. The process of dividing the synthetic resin sheet on the porous substrate into three parts and thermocompression bonding
By setting the stage, a slightly thicker synthetic resin sheet can be arranged on the side portion where gas leaks easily, so that the sealing property is improved. Since the thermocompression bonding to the end face of the porous substrate in the first step can be performed with simple equipment, maintenance is easy and the capital investment cost is reduced. In the thermocompression bonding in the second step, workability is improved because it is not necessary to press the side surface. Further, since there is no need to press the side surface, generation of burrs from the end of the porous substrate has been eliminated.

Next, the results of experiments conducted to prove the effect of the present invention will be described. The material of the porous substrate is Showa Denko's porous carbon, 2 mm thick and 100 mm wide.
The synthetic resin sheet 4 for pressure-bonding to the end face of the porous body in the first step is made of Daikin Neoflon FEP (model N
F0250) An experiment was conducted using a synthetic resin sheet 10 having a thickness of 0.25 mm and a synthetic resin sheet 10 for thermocompression bonding on the front and back surfaces in the second step, using Daikin NEOFLON FEP, type name NF0100, and thickness 0.1 mm. The experimental conditions were as follows: the heating temperature of the porous substrate was 290 to 300 ° C., and the pressure was 10 kg / cm ² .

Next, the results of the above experiment will be described. No gas leakage from the porous substrate was observed, and good results were obtained.
When the inside of the porous substrate was photographed with a microscope photograph, the inside of the porous substrate was impregnated with the synthetic resin sheet.
It was confirmed that the solution penetrated to a depth of 2 to 0.3 mm.

Embodiment 2 FIG. Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows a second embodiment of the present invention.
FIG. 4 is a view for explaining a step of pressing a synthetic resin sheet according to the first embodiment of the present invention. In the first step of the first embodiment, a synthetic resin sheet is placed on one end side of a porous substrate from one corner to the other corner. 2 shows a process of sequentially supplying the synthetic resin sheet toward the end and simultaneously performing thermocompression bonding to the side surface of the end of the porous substrate. In the figure, 1 is a porous substrate, 4 is a synthetic resin sheet in a state of being pressed against the end of the porous substrate, and 2 is a means for pressing the synthetic resin sheet 4 to the end surface of the porous substrate. It is a roller 2 with a guide. The guide-equipped roller 2 has a side surface 1 including a corner portion of the porous substrate 1.
e, 1a, 1h, while moving horizontally,
It is mounted on a movable base capable of applying a pressing force perpendicular to the surface in any direction. Synthetic resin sheet 4
Are thermocompression-bonded sequentially in the order of 1e, 1a, and 1h along the side surface of the end of the porous substrate 1 by the rotational movement and pressure of the roller 2 with the guide.

Next, the operation will be described. After the synthetic resin sheet 4 is heated by the heating block 6 to a temperature suitable for thermocompression bonding, the synthetic resin sheet 4 is processed into a predetermined width at a corner 1 e on an end side surface of the porous substrate 1 parallel to the gas flow path 20. The sheet is thermocompression-bonded at the same time as the sheet is supplied, and is sequentially adhered and thermocompression-bonded from the straight portion 1a to the other corner 1h. Subsequent to the first step, as in the first embodiment, a synthetic resin sheet thinner than the side surface is thermocompression-bonded to the front and back surfaces of the end of the porous substrate 1 as a second step.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a perspective view showing the attaching procedure of an apparatus for thermocompression bonding the synthetic resin sheet 4 to the side surface of the end of the porous substrate. In the figure, 1 is a porous substrate, 2
Is a roller with a guide, and 16 is a pressure roller. In this embodiment, a pressure roller 16 is separately used in addition to the guide roller 2 used in the second embodiment to share the guide and pressure of the synthetic resin sheet 4 during thermocompression. The first step is performed more reliably. The guide-equipped roller 2 and the pressure roller 16 move along the end side surfaces 1e, 1a, 1h of the porous substrate 1, and
It is mounted on a movable gantry capable of applying a pressing force perpendicular to the surface in any direction. The guide-equipped roller 2 is arranged such that the center in the width direction of the synthetic resin sheet 4 is
Guide is performed so as to match the center of the sheet 4 in the thickness direction, and the pressure roller 16 presses the sheet 4. This pressing force is 300 g to 400 g.

Next, the operation will be described. End face 1 of porous substrate 1 pressed from above and below by heating block 6
e, 1a and 1h are heated by the heating block 6 to a constant temperature suitable for thermocompression bonding. On the other hand, the synthetic resin sheet 4 to be thermocompression-bonded is cut into a fixed width, supplied to the guide roller 2 from a sheet supply roller (not shown), and positioned and set at the center of the porous substrate end surfaces 1e, 1a, 1h in the vertical direction. You. The synthetic resin sheet 4 is restricted in the width direction, and at the same time, is required for thermocompression bonding to the porous substrate end face 1e.
g to 400 g. End face 1e
, The synthetic resin sheet is thermocompression bonded to the end face. The synthetic resin sheet 4 thermocompression-bonded to the end face 1e of the porous base body is sequentially pressed from the end corner section 1e to the porous base end section 1a in the direction of arrow B, and the other corner section 1 is formed.
h.

Next, the operation will be described. The synthetic resin sheet pressed and pressed with a pressing pressure of 300 to 400 g against the side surface of the end of the porous substrate is thermocompressed without generating wrinkles, breakage, and bubbles on the end surface.

Embodiment 4 FIG. A fourth embodiment of the present invention will be described with reference to the drawings. In this embodiment, in the first step of the first embodiment, a synthetic resin sheet 4 wider than the thickness of the porous substrate 1 is used, and the upper and lower edges of the sheet are bent to form an end portion of the porous substrate. It is designed to be crimped in a U-shape. FIG. 4 is a perspective view showing the attaching procedure of an apparatus for thermocompression bonding the synthetic resin sheet 4 to the end of the porous substrate. In the figure, 1 is a porous substrate, 2 is a roller with a guide, and 3 is a pressure roller with a bent portion. Further, a roller 2 with a guide and a pressure roller 3 with a bent portion
Are individually porous substrate end faces 1a, porous substrate corners 1e,
It is a structure that moves in the direction perpendicular to the corner 1h as shown by the arrow E.
The structure is such that the porous substrate is pressed against the end face of the porous substrate with a force of 0 g. Further, the guide-equipped roller 2 and the bend-equipped pressure roller 3 are provided along the side surface of the end of the porous substrate 1e,
1a and 1h are always mounted on a movable gantry that moves horizontally from one end to the other end in the horizontal direction in parallel with each end face. The guide roller 2 has a groove having the same dimension and width as the synthetic resin sheet 4 to be thermocompression-bonded, and is arranged at the center of the end surface 1a of the end of the porous substrate. The pressure roller 3 with a bent portion has a role of bending and thermocompression-bonding the synthetic resin sheet 4 to the front and back surfaces of the end portion 1 of the porous base, and has a dimension width including the thickness of the end of the porous base 1 and the thickness of the sheet. It has a groove. The depth of the groove has a structure deeper than the length dimension of bending the sheet into the front surface 1b and the back surface 1c.

Next, the operation will be described. End side surfaces 1e, 1a, 1h, front surfaces 1d, 1b, 1g, back surface 1f, of porous substrate 1 pressed from above and below by heating block 6
1c and 1j are heated by the heating block to a constant temperature suitable for thermocompression bonding. On the other hand, the synthetic resin sheet 4 to be thermocompression-bonded is cut into a fixed width, supplied to the guide roller 2 from the sheet supply roller (not shown), and positioned and set at the center of the porous substrate end side surfaces 1e, 1a, 1h. You. The positioned synthetic resin sheet 4 is placed on a moving block (not shown) and guided to the press-fit roller 3 with a bent portion that moves simultaneously. The supplied synthetic resin sheet 4a is regulated in the vertical direction, and is pressed against the porous substrate end face 1e in the directions of arrows C and D with a pressing force of 300 g to 400 g required for thermocompression bonding. By pressing against the side surface 1e, the synthetic resin sheet is thermocompression-bonded to the side surface. The synthetic resin sheet 4 thermocompression-bonded to the side face 1e of the porous substrate is further subjected to a pressure roller 3 having a bent portion to form a front surface 1d and a back surface 1d.
and is thermocompression bonded to the front surface 1d and the back surface 1f.
In this manner, the end corner portion 1 is moved in the direction of arrow B.
e, 1d, 1f sequentially from the porous substrate ends 1a, 1b, 1
c and then thermocompression-bonded sequentially to the other corners 1h, 1g, 1j.

Next, the operation will be described. The thermocompression-bonded synthetic resin sheet 4 can produce a flat surface without wrinkles and burrs. Further, in the sealing test after the final pressure bonding in the second step, good results were obtained without any leakage. This seal device can be manufactured at low manufacturing cost due to its simple structure.

Next, the results of experiments performed to prove the embodiment of the present invention will be described. The material was porous substrate 1, porous carbon manufactured by Showa Denko, thickness 2 mm, width 1
An experiment was performed using 00 mm × 100 mm, and using a synthetic resin sheet 4 made of Daikin NEOFLON FEP, model name NF0250, and thickness 0.25 mm. Next, the environment will be described. The heating temperature of the heating block 6 is set at 270 to 300 ° C. at the end of the porous base to be thermocompressed, and the pressing force of the guide roller 2 and the crimping roller 4 with a bend onto the porous base end 1 a is 300 to 300 ° C. The experiment was performed under the conditions of 400 g and a pressure bonding speed of 600 mm / min.

Next, the results of the above experiment will be described. When the width of the U-shaped bent portion on the front and back surfaces of the synthetic resin sheet became 3 mm or more, the bent front end portion tended to float. No lifting is observed by setting the bending amount to 3 mm or less. Further, an experiment was conducted by changing the shape of the end portion 1 of the porous substrate. Side surface 1 of porous substrate end 1
The a, 1e, and 1h portions were subjected to a 45 mm square chamfering process on both the front and back sides with a width of 0.5 mm, and a compression bonding experiment was performed. At this time, the crimping roller with a bend was also processed so as to have the same shape as the end face shape of the porous substrate, and crimping was performed sequentially from the end. As a result, the shape of the synthetic resin sheet after crimping changed from a U-shape to a U-shaped cross-section, and good results were obtained. Next, an experiment was conducted by changing the shape of both corners at the end of the porous substrate 1. When both corners are formed in a radius of 5 mm, and when the edge of the porous substrate 1 is 45 mm from a position 5 mm from the corner end.
In two cases in which the shape of 5C was cut off at a degree angle, good results could be obtained without breaking, wrinkling or peeling of the synthetic resin sheet under any conditions.

Embodiment 5 A fifth embodiment of the present invention will be described with reference to the drawings. In this embodiment, the function of the crimping roller 3 with a bent portion in the fourth embodiment is replaced by three crimping rollers 5a, 5b, 5c in three directions perpendicular to each other.
It is what was shared. In this method, the porous substrate 1
There is an advantage that the pressing force toward the front and back surfaces of the end can be freely and stably applied. FIG. 5 shows the porous substrate end 1.
It is a perspective view which shows the sticking point of the apparatus which thermocompression-bonds the synthetic resin sheet 4 to the sheet. In the figure, 1 is a porous substrate, 2 is a roller with a guide, and 5 is a three-side independent roller for pressing the side surface, front surface, and back surface of the porous substrate 1 against an individual surface. Further, the guide-equipped roller 2 and the three-sided independent roller 5 individually move in a direction perpendicular to the porous substrate end face 1a, the porous substrate corner 1e, and one corner 1h. Is pressed against the side surface 1a, the front surface 1b, and the back surface 1c of the end of the porous substrate with a force of 300 g to 400 g. In addition, guided rollers 2
And the three-sided independent roller 5 are connected to the end faces 1e, 1a, 1h of the porous substrate.
A moving block (not shown) that always moves in full width from one end to the other in parallel with the front and back sides in parallel with each end face
It is placed on. The guide-equipped roller 2 has a groove having the same width as the width of the synthetic resin sheet 4 to be thermocompression-bonded, and is arranged at the center of the end face 1a of the end of the porous substrate. The three-sided independent roller 5 includes three rollers, and the upper-side roller 5b
Are the surfaces 1d, 1b, and 1g of the end of the porous substrate, and the lateral rollers 5a are the end surfaces 1e, 1a, and 1h of the end of the porous substrate.
And the lower roller 5c is the back surface 1f, 1
c and 1j are independently moved while being pressed and rotated with a force of 300 g to 400 g.

Next, the operation will be described. End face 1 of porous substrate 1 pressed from above and below by heating block 6
e, 1a, 1h, front surface 1d, 1b, 1g, back surface 1f, 1
The blocks c and 1j are heated by the block to a constant temperature suitable for thermocompression bonding. On the other hand, the synthetic resin sheet 4 to be thermocompressed
Is cut into a predetermined width 4a and supplied to the guide roller 2 from the sheet supply roller (not shown), and the porous substrate end face 1
e, 1a, and 1h are positioned and set at the center. The positioned synthetic resin sheet 4 is placed on a moving block (not shown), and the synthetic resin sheet 4 is guided to three-side independent rollers 5 that move simultaneously. The supplied sheet 4 is regulated in the vertical direction, and 300 g required for thermocompression bonding to the end face 1e.
It is pressed with a pressing force of 400 g. By pressing against the end face 1e, the synthetic resin sheet is thermocompression-bonded to the end face. The synthetic resin sheet 4 thermocompression-bonded to the end face 1e of the porous substrate is further subjected to three-sided independent rollers 5 to form a surface 1d,
It is crimped while being bent on the back surface 1f. In this manner, the end portions 1e, 1d, and 1f are sequentially pressed in the direction of arrow b to the porous substrate ends 1a, 1b, and 1c, and are sequentially pressed to one of the corner portions 1h, 1gg, and 1j.

Next, the operation will be described. The synthetic resin sheet is crimped in a U-shape sequentially from the corner of one end of the porous substrate 1 to the opposite corner while the end parallel to the gas flow path is crimped to the synthetic resin sheet. Since thermocompression bonding is sequentially performed from one end, it is possible to cope with a displacement or the like due to distortion or bending of the end portion of the porous substrate, and high quality can be stably obtained with an inexpensive apparatus.

Next, the results of experiments performed to prove the effect of this embodiment will be described. The material was porous substrate 1 made of Showa Denko's porous carbon, 2 mm thick, 1 width.
Use 00mm x 100mm. Synthetic resin sheet 4 is made of Daikin NEOFLON FEP, model name NF0250, thickness 0,
The experiment was performed using 25 mm. Next, the environment will be described. The heating temperature of the heating block 6 is set at 270 to 300 ° C. at the end of the porous substrate to be thermocompressed, and the guide roller 2 and the three-side independent roller 5 are connected to the porous substrate end 1.
a, 1b, and 1c all have a pressing force of 300 to 4
The experiment was performed under the conditions of 00 g and a pressure bonding speed of 600 mm / min.

Next, the experimental results will be described. The U-shaped bent surface on the front and back of the synthetic resin sheet has 3
mm or more, when compared to the fourth embodiment, in which the bent front end tends to float, no lift is observed on the front and back surfaces of the synthetic resin sheet. Good results were obtained without wrinkles, flexures, or breaks without any problem. In the case where the bending surface width is 3 mm or more, it is preferable to use a structure using three independent rollers. Further, an experiment was conducted by changing the shape of the end of the porous substrate 1. End faces 1a, 1e,
A 1 mm portion was chamfered with a width of 0.5 mm and a 45 degree angle on both the front and back sides, and a crimping experiment was performed. As a result, the shape of the synthetic resin sheet after crimping changes from a U-shape to a U-shape,
Good results were obtained. Next, an experiment was performed by changing the shape of both corners at the end of the porous substrate 1. 5mm for both corners
5 m from the corner of the end of the porous substrate 1
In an experiment with a 5C shape cut off at an angle of 45 degrees from the m position, good results could be obtained without breaking, wrinkling, or peeling of the synthetic resin sheet under any conditions.

Embodiment 6 FIG. A sixth embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a cross-sectional view of a main part showing an attaching procedure of an apparatus for thermocompression-bonding a synthetic resin sheet to an end portion of a porous substrate, and states A to C show a thermocompression bonding process flow of the synthetic resin sheet 4. In the figure, 1 is a porous substrate,
Reference numeral 4 denotes a synthetic resin sheet, reference numeral 6 denotes a heating block, and reference numeral 13 denotes a molding die with an adsorption function mounted on a moving mechanism (not shown) that moves in a direction perpendicular to the end of the porous substrate 1. The mold 13 with a suction function is a vacuum exhaust block 13d / 13e, a compression spring 13c, a mold block 13a, a suction block 13b.
When pressed against the end of the porous substrate 1, the structure is pressed against the end of the porous substrate 1 with a pressing force of ³ to 4 kg / cm ^{2 in} the direction of arrow B. The mold 13 with a suction function is provided with a positioning mechanism and an exhaust port for vacuum-sucking the synthetic resin sheet 4 at the center of the mold. Further, a vacuum pump (not shown) is provided at the end of the exhaust port 13d. Next, the process flow will be described. State A shows a state where the synthetic resin sheet 4 cut into a certain width and length is mounted. State B shows a state in which the mold 13 with the adsorption function is pressed against the end of the porous substrate 1.
Is pressed with a constant pressure on the side of the end. State C shows a state in which the mold with adsorption function 13 has been retracted from the side surface of the end of the porous substrate 1 by a moving mechanism (not shown) after thermocompression bonding, and has been separated from the porous substrate 1.

Next, the operation will be described. The porous substrate 1 is heated by the heating block 6 to a temperature suitable for thermocompression bonding of the synthetic resin sheet 4. In the state A, the synthetic resin sheet 4 processed into a width and a length suitable for thermocompression bonding to the side surface of the end portion of the porous substrate 1 is positioned and attached to the mold 13 with the suction function. Vacuum is exhausted in the direction of arrow A through the exhaust ports 13d and 13e by a vacuum pump (not shown) and is adsorbed. The mold 13 with the suction function placed on the moving mechanism (not shown) is pressed toward the end of the porous substrate 1 (arrow B) (state B). In the state B, the synthetic resin sheet 4 pressed against the side surface of the end of the porous substrate 1 with a pressing force of 3 to 4 kg / cm ² by the compression spring 13c is thermocompression-bonded to the side surface of the end of the porous substrate. After leaving for 10 to 20 seconds, the vacuum suction is released, and the mold 13 with the suction function is retracted to the state C position. The suction block 13b of the mold 13 with the suction function returns to the home position by the return force of the compression spring 13c.

Next, the operation will be described. Since the synthetic resin sheet 4 can be pressed and pressed against the side surface of the end portion of the porous substrate 1 at a stretch, work can be performed in a short time and work efficiency is high, so that the structure is suitable for automation.

Embodiment 7 FIG. A seventh embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a cross-sectional view of a main part showing an attaching procedure of an apparatus for thermocompression bonding the synthetic resin sheet 4 to an end portion of the porous substrate 1, and states A to C show a synthetic resin sheet thermocompression bonding process flow. Show. In the drawing, 1 is a porous substrate, 4 is a synthetic resin sheet, 6 is a heating block, and 7 is a molding mounted on a moving mechanism (not shown) that moves in a direction perpendicular to the side surface 1a of the end of the porous substrate. It is a mold. Mold 7
Is composed of evacuation blocks 7d and 7e, a compression spring 7c, a mold block 7a and a suction block 7b. When pressed against the end of the porous base 1, 3 to 4 kg / cm in the direction of arrow B
^The structure is such that the pressing force of ² presses against the end of the porous substrate 1. Synthetic resin sheet 4 in the center of molding die 7
There is provided an exhaust port for vacuum mounting. Further, an exhaust pump (not shown) is provided at the end of the exhaust port 7d. The flow will be described. State A shows a state where the porous substrate 1 is heated by the heating block 6 to a temperature suitable for pressing the synthetic resin sheet. Also, a state in which a synthetic resin sheet 4 processed to a fixed width and length is attached to the molding die 7 is shown. State B shows a state in which the molding die 7 is pressed against the end 1 of the porous substrate. State C shows a state where the molding die 7 is separated from the end of the porous substrate 1.

Next, the operation will be described. In the state A, the synthetic resin sheet 4 processed into a width and length suitable for thermocompression bonding to the side surface of the end portion of the porous substrate 1 is attached to the molding die 7. After mounting, vacuum suction (not shown) is used to prevent falling, misalignment and the like. In the state B, the molding die 7 vacuum-mounted in the state A on the end of the porous base 1 heated to a predetermined temperature suitable for thermocompression bonding from above and below by the heating block 6 with respect to the end of the porous base 1 Press a moving mechanism (not shown) that moves at right angles and horizontally. 3-4 kg / cm in the direction of arrow B while being pressed against the end side surface 1a of the porous substrate
The force of ² works and it is crimped. The synthetic resin sheet 4 hits the end side surface 1a of the porous substrate and continues to push the moving mechanism so that the suction block 7b moves the compression spring 7 in the direction of arrow C.
Defeat C and slide. By this operation, the synthetic resin sheet 4 is pressed against the end side surface 1a of the porous substrate and bent in the direction of the front surface 1b and the back surface 1c. At the same time as being bent, it is thermocompression bonded to the front and back surfaces 1b and 1c of the porous substrate 1 heated to a temperature suitable for pressure bonding. The vacuum pump is released in a state of being bent and crimped on the front and back surfaces, and the molding die is moved by a moving mechanism (not shown) at the end surface 1 of the porous substrate.
Retreat from a. When returning to the position of the state C, the synthetic resin sheet is pressed in a U-shape like 4a, 4b, 4c at the end of the porous substrate, and the molding block 7 returns to the origin position and at the same time, the suction block 7b is It returns with the force of the spring 7c.

Next, the operation will be described. The thermocompression-bonded synthetic resin sheet 4 can produce a flat surface without wrinkles, breakage, and burrs. Furthermore, good results were obtained without any leakage even in a sealability test after the completion of the pressure bonding step. This seal device can be manufactured at low manufacturing cost due to its simple structure.

Embodiment 8 FIG. An eighth embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a side cross-sectional view of a main part showing an attaching procedure of an apparatus for thermocompression-bonding a synthetic resin sheet to an end portion of a porous substrate, and states A to C show a thermocompression bonding process flow of the synthetic resin sheet 4. . In the figure, 1 is a porous substrate, 4 is a sheet made of synthetic resin, 6 is a heating block, and 8 is a bend placed on a moving mechanism (not shown) that moves in a direction perpendicular to the end of the porous substrate 1. This is a mold with a mechanism. The metal mold 8 with a bending mechanism, when pressed against the end side surface of the porous substrate at the time of thermocompression bonding, has 3 to 4 kg / g between the end surface of the porous substrate and the mold.
a compression spring 8c for applying a force of ² cm ² , a pressing metal 8g for pressing the synthetic resin sheet 4 into a U-shape, and a fulcrum pin 8 for bending the bending metal.
f, and an exhaust port for vacuum suction of the synthetic resin sheet 4 is provided at the center of the mold. Furthermore, the exhaust port 8
A vacuum pump (not shown) is installed at the end of d.
The flow will be described. State A shows a state in which the synthetic resin sheet 4 processed to a constant width and length is mounted. State B shows a state in which the mold 8 with the bending mechanism is pressed against the end of the porous substrate 1. State C is a synthetic resin sheet 4
Shows the state of returning to the origin after crimping.

Next, the operation will be described. The porous substrate 1 is heated by the heating block 6 to a temperature suitable for thermocompression bonding of the synthetic resin sheet 4. In state A, the synthetic resin sheet 4 processed into a width and length suitable for thermocompression bonding to the side surface of the end of the porous substrate 1 is positioned and mounted on a mold 8 with a bending mechanism. Vacuum is exhausted in the direction of arrow A through the exhaust ports 7d and 7e by a vacuum pump (not shown), and is absorbed. A mold 8 with a bending mechanism placed on a moving mechanism (not shown) is pressed in the direction of the end face of the porous substrate 1 (arrow B) (state B). When the mold 8 with a bending mechanism is pressed against the end of the porous base 1 in the state B, the suction block 8b hits the end face 1a of the porous base, and the synthetic resin sheet 4 is sandwiched between the end face and the suction block. Further, the mold block 8a advances by overcoming the force of the compression spring 8c. At this time, the bending metal fitting 8g is pressed by the mold block 8a and is bent with the fulcrum pin 8f as a fulcrum, and the synthetic resin sheet 4 is bent into a U-shape by the bending pipe 8g. The mold block 7a is 3 to 4 kg / c.
Advances and stops until a pressing force of m ² is generated. The pressed synthetic resin sheet 4 is thermocompression-bonded to the end face and the front and back surfaces of the porous substrate. After leaving for 10 to 20 seconds, the vacuum suction is released, and the mold 8 with the bending mechanism is retracted to the state C position. Suction block 8b of mold 8 with bending mechanism
Returns to the original position by the return force of the compression spring 8c.

Next, the operation will be described. Since no frictional force acts when the synthetic resin sheet is bent, it is possible to press the thin synthetic resin sheet with good quality even by thermocompression. Since the synthetic resin sheet 4 can be pressed and pressed against the side surface of the end portion of the porous substrate 1 at a stretch, the work can be performed in a short time, so that the work efficiency is improved and the structure is suitable for automation.

Embodiment 9 FIG. A ninth embodiment of the present invention will be described with reference to the drawings. FIG. 9 shows a synthetic resin sheet 10 (10a, 1a) after thermocompression bonding of the synthetic resin sheet to the end of the porous substrate 1 in the first step in the first to eighth embodiments.
0b) is thermocompression-bonded to the front and back surfaces of the end of the porous substrate 1.
It is a figure explaining a process. In the figure, 1 is a porous substrate, 4 is 0.2 to 0.25 pressed to an end of the porous substrate.
A slightly thick synthetic resin sheet of about mm, 9 is a press-fit press with a heating mechanism, 10a and 10b are partially overlapped with the synthetic resin sheet 4 press-fitted to both corners, or the ends of the sheets are butted by thermocompression. A synthetic resin sheet slightly thinner, about 1 to 0.15 mm, and 14 is a separator plate. States AB illustrate the crimping process.

Next, the operation will be described. Seal the front and back surfaces by thermocompression bonding to the front and back surfaces of the porous substrate end.
A slightly thinner front and back synthetic resin sheet 1 ~ 0.15mm
0a and 10b are processed in advance to a predetermined width and length. State A
In the above, the front and back synthetic resin sheet 10b, the synthetic resin sheet 4 is already pressed into a U-shape on the press 9b with a heating mechanism, the porous substrate 1, the front and back synthetic resin sheet 10
a, The separators 14 are stacked in order from the bottom. At this time, the front and back surfaces of the synthetic resin sheet 4 previously compressed and the newly stacked front and back synthetic resin sheets 10a and 10b are aligned and overlapped. The stacking of the porous substrate 1 and the separator 14 is performed in alignment in consideration of the change of the synthetic resin sheet after pressure bonding. State B shows a state in which the cells aligned in the state A are pressed, and after pressing at a predetermined pressure, the press 9 with a heating mechanism (9a, 9b) is heated to a predetermined temperature. At this time, the applied pressure is 10 kg / cm ² , the heating temperature is 290 to 300 ° C., and the pressing time is 290 to 300.
When the temperature reaches ° C, the heater is turned off to cool naturally. 25
It is dismantled at the stage when it is naturally cooled to 0 ° C.

Next, the operation will be described. In the state B in which the thermocompression bonding in the second step is completed, the synthetic resin sheets 4 and 10 impregnate the porous substrate 1 and are absorbed, so that the front and back surfaces of the end of the porous substrate 1 become flat. In addition, the cross-sectional shape of the synthetic resin sheet on the side surface of the end portion of the porous substrate 1 is a shape having an outward convex roundness, and burrs are not generated. After the synthetic resin sheet was heat-pressed on the porous substrate 1, the permeation surface of the synthetic resin on the front and back surfaces of the porous substrate was measured with a microscope. As a result, the synthetic resin sheet had permeated to a depth of 0.2 to 0.3 mm.
In the test of the sealing property, when a small amount of the synthetic resin sheet 4 is slightly overlaid on the synthetic resin sheet 4 thermocompressed in a U-shape and thermocompression-bonded, the reliability of the seal from the end increases. Further, the slightly thin front and back synthetic resin sheet 10 is attached to the synthetic resin sheet 4 pressed in a U-shape.
When (10a, 10b) is pressed against each other, a good shape can be obtained without generating burrs from the end of the porous substrate. No leakage occurred in any case. Based on the above results, the first step of thermocompression bonding the synthetic resin sheet to the end of the porous substrate in a U-shape and the second step of thermocompression bonding a slightly thinner synthetic resin sheet to the front and back surfaces are performed. Thus, a high quality porous substrate can be manufactured at low cost.

Embodiment 10 FIG. A tenth embodiment of the present invention will be described with reference to the drawings. This embodiment is different from the ninth embodiment in that the synthetic resin sheet 4 previously thermocompressed to the end of the porous base 1 in the first step and the end of the porous base 1 in the second step The present invention relates to a temporary fixing for accurately aligning the synthetic resin sheets 10 (10a, 10b) which are newly thermocompression-bonded to the front and back surfaces, and preventing displacement. FIG. 10 is a perspective view showing a state in which a synthetic resin sheet is thermocompression-bonded to the end of the porous substrate, and then the synthetic resin sheet is superimposed on the front and back surfaces of the end of the porous substrate 1 or temporarily butted with a heating rod. It is. In the figure, 1 is a porous substrate, 4 is a thermo-compressed synthetic resin sheet in advance, 10 is a synthetic resin processed to the same length and a predetermined width as the front and back surfaces of the porous substrate at the front and rear ends parallel to the gas flow path. The sheet 15 is a heating rod for spot thermal connection.

Next, the operation will be described. The synthetic resin sheet 10 previously processed to a predetermined length and width is partially overlapped or abutted on the end of the synthetic resin sheet 4 in which the synthetic resin sheet 4 is thermocompression-bonded to the end face of the porous substrate in advance. Do. The heating rod 15 heated to a predetermined temperature is pressed in a state where the positioning is completed, and spot heat welding is performed at predetermined intervals. Next, the porous substrate 1 is turned upside down and subjected to thermal welding in the same manner as the surface.

Next, the operation will be described. By performing the spot thermal welding, when the combined thermocompression bonding, which is the second step, is performed, the synthetic resin sheet pre-pressed to the end face and the synthetic resin sheet press-bonded to the front and back surfaces are not displaced and work is efficiently performed. Quality as well as quality.

Next, the result of an experiment for verifying the results will be described. Positioning is performed so that the synthetic resin sheet 4 and the synthetic resin sheet that is attached to the front and back surfaces and thermocompression-bonded can be overlapped by about 1 mm. Next, the heating probe 15 is pressed against the overlapping portion of the side synthetic resin sheet 4 and the front and back synthetic resin sheets 10. At this time, heating rod 1
5 The diameter of the tip is Φ2 mm, and the temperature of the tip is 280 to 30
The pressing was performed at 0 ° C. for 2 seconds. As a result, the superposed synthetic resin sheets are adhered to each other and 30 to 40 g.
It can withstand a certain amount of pulling force. In addition, by performing spot thermal welding, when the combined thermocompression bonding, which is the second step, is performed, the synthetic resin sheet pre-pressed to the end face and the synthetic resin sheet press-bonded to the front and back surfaces can be efficiently moved without any displacement. Quality will increase with the progress of

Embodiment 11 FIG. An eleventh embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a perspective view showing a state in which a synthetic resin sheet is thermocompression-bonded to the end of a porous substrate, and then the synthetic resin sheet is overlapped or butted on the front and back surfaces and fixed by an ultrasonic vibration element. In the figure, 1 is a porous substrate, 4 is a thermo-compressed synthetic resin sheet,
Reference numeral 10 denotes a synthetic resin sheet processed to have the same length and predetermined width as the front and rear surfaces of the end of the porous substrate parallel to the gas flow path. Reference numeral 17 denotes an ultrasonic vibration element for spot heat connection.

Next, the operation will be described. The synthetic resin sheet 10 previously processed to a predetermined length and width is partially overlapped or abutted on the end of the synthetic resin sheet 4 in which the synthetic resin sheet 4 is thermocompression-bonded to the end face of the porous substrate in advance. Do. Arrow A /
The ultrasonic vibration element 16 vibrating in the direction B is pressed to perform spot heat welding at predetermined intervals. Next, the porous substrate 1 is turned over and heat-welded in the same manner as the surface.

Next, the operation will be described. Therefore, when the combined thermocompression bonding, which is the second step, is performed, the synthetic resin sheet pre-pressed to the end face and the synthetic resin sheet press-bonded to the front and back surfaces are not displaced. .

[0060]

According to the first and second constitutions of the present invention, a synthetic resin sheet is thermocompression-bonded in advance to the end of the porous substrate in a U-shape, and then another synthetic resin sheet is attached to the front and back surfaces. By adopting the manufacturing method, the sealability is improved, and wrinkles and burrs are not generated on the synthetic resin sheet, which leads to an improvement in quality.

Further, according to the third configuration of the present invention, it is possible to manufacture the synthetic resin sheet by changing the thickness of the synthetic resin sheet at the end portion and the front and back surfaces. The cell thickness can be suppressed by arranging a thin synthetic resin sheet on the front and back surfaces of the sheet, for which the degree of necessity for sealing is low.

According to the fourth aspect of the present invention, it is possible to easily perform alignment between the synthetic resin sheet thermocompression-bonded in the first step and the sheet thermocompression-bonded in the second step, and to prevent displacement. Therefore, a high quality seal can be obtained.

According to the fifth aspect of the present invention, a synthetic resin sheet is thermocompression-bonded in advance in a U-shape to the end of the porous substrate, and then another synthetic resin sheet is attached to the front and back surfaces. By adopting the method, the sealing property is improved, and wrinkles and burrs are not generated on the synthetic resin sheet, which leads to an improvement in quality.

According to the sixth to ninth structures of the present invention, the thermocompression bonding method of the synthetic resin sheet to the end of the porous substrate can be performed by a device having a simple structure. Can be suppressed. Furthermore, even if the area of the porous substrate becomes large, only the moving mechanism needs to be lengthened, so that capital investment costs can be reduced. Furthermore, even if the sealing length of the end face of the porous substrate is increased and the end face of the porous substrate is bent or deformed, the shape of the end face can be followed, so that the quality of the finished product can be ensured.

According to the tenth to twelfth structures of the present invention, the synthetic resin sheet can be thermocompression-bonded to the end of the porous substrate instantaneously in a U-shape, so that the working efficiency is good and mass production can be supported. Furthermore, since the shape of the mold is simple, even if it is adopted for a mass production device, the device has excellent maintainability.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a pressure bonding step of a synthetic resin sheet according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a pressure bonding step of a synthetic resin sheet according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating a pressure bonding step of a synthetic resin sheet according to a third embodiment of the present invention.

FIG. 4 is a view illustrating a pressure bonding step of a synthetic resin sheet according to a fourth embodiment of the present invention.

FIG. 5 is a view illustrating a pressure bonding step of a synthetic resin sheet according to a fifth embodiment of the present invention.

FIG. 6 is a view illustrating a pressure bonding step of a synthetic resin sheet according to a sixth embodiment of the present invention.

FIG. 7 is a view illustrating a pressure bonding step of a synthetic resin sheet according to a seventh embodiment of the present invention.

FIG. 8 is a view illustrating a pressure bonding step of a synthetic resin sheet according to an eighth embodiment of the present invention.

FIG. 9 is a diagram illustrating a pressure bonding step of a synthetic resin sheet according to a ninth embodiment of the present invention.

FIG. 10 is a diagram illustrating a pressure bonding step of a synthetic resin sheet according to a tenth embodiment of the present invention.

FIG. 11 is a diagram illustrating a pressure bonding step of a synthetic resin sheet according to an eleventh embodiment of the present invention.

FIG. 12 is a cross-sectional view illustrating a pressure bonding step of a synthetic resin sheet according to a conventional technique.

FIG. 13 is a perspective view illustrating a fuel cell body.

[Explanation of symbols]

1 porous substrate, 2 guide rollers with flange, 3
Crimping roller with flange, 4 sheets made of synthetic resin, 5 independent rollers, 6 heating block, 7 molding die, 8
Mold with bending mechanism, 9 Press with heating mechanism,
10 front and back synthetic resin sheet, 11 electrodes, 12 electrolyte plate, 13 mold with adsorption function, 114 separator, 1
5 heating rod, 16 pressure roller, 17 ultrasonic transducer,
21 male mold, 22 female mold, 24 fluorine oil release agent.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshinobu Higashishima 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Tamotsu Itoyama 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 Rishi Electric Co., Ltd. (72) Inventor Shoichiro Hara 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. Inside the corporation

Claims (12)

[Claims] A first step of thermocompression-bonding a first synthetic resin sheet to side surfaces and front and back surfaces of an end portion of the porous gas diffusion electrode of the phosphoric acid type fuel cell which is parallel to the gas flow path, The second and third synthetic resin sheets are sandwiched between two parallel heating press members and thermocompression-bonded to the front and back of the porous electrode end, respectively, and the first to third synthetic resin sheets are bonded to the porous sheet. A porous gas diffusion electrode for a phosphoric acid-type fuel cell, in which a second step of impregnating and absorbing an electrode is performed to flatten the front and rear end portions of the porous electrode. 2. A first step of thermocompression-bonding a first synthetic resin sheet to side surfaces and front and back surfaces of an end portion of a porous gas diffusion electrode of a phosphoric acid type fuel cell which is parallel to a gas flow path, The second and third synthetic resin sheets are sandwiched between two parallel heating press members and thermocompression-bonded to the front and back of the porous electrode end, respectively, and the first to third synthetic resin sheets are bonded to the porous sheet. A method for producing a porous gas diffusion electrode of a phosphoric acid type fuel cell, wherein a second step of impregnating and absorbing the electrode is performed to make the front and rear end portions of the porous electrode flat. 3. The three synthetic resin sheets, wherein the thickness of the sheet thermocompression-bonded to the side surface of the porous substrate is greater than the thickness of the sheet thermocompression-bonded to the front and back surfaces of the porous substrate. Item 3. The method for producing a porous gas diffusion electrode for a phosphoric acid fuel cell according to Item 2. 4. In the second step, the second and third synthetic resin sheets are attached to the first synthetic resin sheet thermocompression-bonded to the front and back surfaces of the end of the porous substrate in the first step. 3. The method for producing a porous gas diffusion electrode of a phosphoric acid fuel cell according to claim 2, further comprising a step of temporarily fixing the porous gas diffusion electrode. 5. A means for performing a first step of thermocompression-bonding a first synthetic resin sheet to side surfaces and front and back surfaces of an end portion of a porous gas diffusion electrode of a phosphoric acid fuel cell which is parallel to a gas flow path. ,
On each of the front and back surfaces of the end portion of the porous electrode, the second and third synthetic resin sheets are sandwiched between two parallel heating press members and thermocompression-bonded, and the first to third synthetic resin sheets are bonded to each other. An apparatus for manufacturing a porous gas diffusion electrode for a phosphoric acid fuel cell, wherein the porous electrode is provided with means for performing a second step of impregnating and absorbing the porous electrode so that the front and back surfaces of the porous electrode are formed in a flat shape. . 6. When the synthetic resin sheet is thermocompression-bonded to the front, back, and side surfaces of the porous substrate, the porous substrate is heated and the synthetic resin is applied from one corner to the other at the end surface of the porous substrate. 6. The apparatus for producing a porous gas diffusion electrode of a phosphoric acid fuel cell according to claim 5, further comprising means for sequentially supplying sheets made of the same and simultaneously pressing the sheet to the porous substrate by a pressing means. 7. The phosphoric acid mold according to claim 5, further comprising a guide roller with a flange for regulating the position of the synthetic resin sheet in the width direction, and a pressure roller for pressing the synthetic resin sheet to the side surface of the end of the porous substrate. An apparatus for manufacturing a porous gas diffusion electrode for a fuel cell. 8. A sheet made of a synthetic resin is sequentially supplied from one corner of the porous substrate to the other corner while heating the porous substrate, and at the same time, the sheet is bent by a pressing roller with a flange to bend the sheet into a U-shape. 6. The apparatus for producing a porous gas diffusion electrode of a phosphoric acid type fuel cell according to claim 5, further comprising means for pressing the surface of the porous substrate to the side surface and the front and back surfaces of the end of the porous substrate. 9. The porous phosphoric acid fuel cell fuel cell according to claim 5, wherein the pressure roller comprises three rollers, and means for pressing the synthetic resin sheet onto the front, back, and side surfaces of the end of the porous substrate. Gas diffusion electrode manufacturing equipment. 10. When the synthetic resin sheet is thermocompression-bonded to the side surface of the porous substrate, a means for heating the porous substrate and pressing the vacuum-adsorbed and positioned sheet to the side surface of the porous substrate is provided. An apparatus for manufacturing a porous gas diffusion electrode for a phosphoric acid fuel cell according to claim 5. 11. A synthetic resin sheet is heated in a U-shape by a mold block having a suction portion for heating the porous substrate and vacuum-sucking the synthetic resin sheet, and a slide portion sliding with the suction portion as a guide. The apparatus for manufacturing a porous gas diffusion electrode of a phosphoric acid type fuel cell according to claim 5, further comprising means for folding up and pressing the porous substrate on the side and front and back surfaces of the porous substrate. 12. A suction section for vacuum-sucking a synthetic resin sheet, a slide section sliding with the suction section as a guide, and a rotating section which is rotated by being pressed by the slide section.
6. The porous gas for a phosphoric acid-type fuel cell according to claim 5, further comprising means for folding the synthetic resin sheet into a U-shape by a mold block having two rotating parts and pressing the sheet on the side surface and the front and back surfaces of the porous substrate. Diffusion electrode manufacturing equipment.