KR102410805B1 - A carbon paper used in gas diffusion layer of fuel cell and a method of manufacturing thereof - Google Patents

Abstract

The present invention relates to the steps of preparing a phenol impregnation solution in which an acrylic acid binder containing carboxylic acid and a phenol resin are dissolved, impregnating the carbon veil in the phenol impregnation solution and drying it to bind the carbon fibers protruding from the surface of the carbon veil. It provides a method for producing carbon paper applied to a gas diffusion layer of a fuel cell comprising the steps of suppressing the protrusion of the carbon veil and curing, carbonizing and graphitizing the dried carbon veil.

Description

Carbon paper applied to gas diffusion layer of fuel cell and manufacturing method thereof

The present invention relates to carbon paper and a method for manufacturing the same, and to carbon paper and a method for manufacturing the same, which can be easily applied to a thin-film gas diffusion layer of a fuel cell.

In general, a fuel cell is a device that generates electric energy by electrochemically reacting hydrogen and oxygen. Since it directly produces electricity without burning fuel, it is environmentally friendly and has very high power generation efficiency.

Here, the unit cell of the fuel cell is usually stacked in the order of an electrode plate (anode), a gas diffusion layer, a catalyst layer, an electrolyte layer, a catalyst layer, a gas diffusion layer, and an electrode plate (cathode), and hydrogen used as fuel is supplied to the anode. and oxygen is supplied to the cathode.

In the case of carbon paper produced through a carbon veil without removing the carbon fibers protruding from the surface as described above, when applied to a fuel cell, it affects the membrane electrode assembly (at least one of a catalyst layer, an electrolyte layer, and a gas diffusion layer), so that the fuel cell It is important to remove the carbon fiber protruding from the surface as it can act as a cause of lowering the durability and performance of the product.

In addition, on the cathode side, the fuel cell operates on the principle that hydrogen ions (cations) that have moved through the electrolyte layer, electrons that have moved through an external circuit, and supplied oxygen meet to generate water.

Among the components of such a fuel cell, the gas diffusion layer uniformly diffuses and supplies oxygen or hydrogen to the catalyst layer, moves generated electrons quickly, and requires characteristics such as strength to withstand external shocks, so it has excellent strength and electrical conductivity. It is made of carbon fiber-based carbon paper with

In general, carbon paper can be produced by impregnating a carbon veil with a phenol-impregnated liquid and then carbonizing and graphitizing it. It can be manufactured through a (wet-laid) manufacturing process.

Recently, as the gas diffusion layer is thinned, the thickness of the carbon veil becomes thinner compared to the length of the carbon fibers constituting the carbon veil.

In the case of carbon paper produced through a carbon veil without removing the carbon fibers protruding from the surface as described above, when applied to a fuel cell, it may affect the catalyst layer, etc., thereby reducing the durability and performance of the fuel cell. It is important to remove the carbon fibers protruding from the surface.

In addition, in order to increase the efficiency of the fuel cell, it is necessary to quickly and uniformly diffuse the gas supplied to the gas diffusion layer into the catalyst layer, and for this purpose, high gas permeability is required for the carbon paper of the gas diffusion layer.

Patent Publication No. 2020-0076395 (published date: June 29, 2020) "Graphitized carbon substrate and gas diffusion layer employing the same"

In the present invention, the carbon paper applied to the gas diffusion layer of the fuel cell and its manufacturing method, specifically, the carbon veil is impregnated with a phenol impregnated solution mixed with an acrylic acid binder of an appropriate ratio, and the carbon fibers protruding from the surface of the carbon veil are removed. It is an object of the present invention to provide a carbon paper that can increase the gas permeability by forming a uniform impregnated film, ensure durability, and can be easily applied to a thin-film gas diffusion layer.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. will be able

In order to solve the above problems, the present invention provides a step of preparing a phenol impregnating solution in which an acrylic acid-based binder containing carboxylic acid and a phenol resin are dissolved, impregnating the carbon veil in the phenol impregnating solution and drying the surface of the carbon veil It provides a method for producing carbon paper applied to a gas diffusion layer of a fuel cell, comprising the steps of suppressing protrusion from the surface by binding the carbon fibers protruding from the carbon fiber and curing, carbonizing and graphitizing the dried carbon veil.

In addition, the acrylic acid binder provides a method for producing carbon paper in which carboxylic acid is applied to a gas diffusion layer of a fuel cell containing 10 to 50%.

In addition, the acrylic acid-based binder provides a method for producing carbon paper applied to the fuel cell gas diffusion layer, which is mixed in an amount of 5 to 20 parts by weight based on 100 parts by weight of the phenol-impregnated solution.

In addition, the acrylic acid binder is styrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, vinyl chloride, vinyl acetate, acrylonitrile, 2-ethylhexyl methacrylate, lauryl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, ethylene, octadecyl methacrylate, acrylamide It provides a method for producing carbon paper applied to a fuel cell gas diffusion layer, which is a copolymer binder that forms a copolymer with at least one of them.

Meanwhile, in another aspect of the present invention for solving the above-described problems, there is provided a carbon paper applied to a gas diffusion layer of a fuel cell manufactured using the above-described manufacturing method.

In addition, in another aspect of the present invention for solving the problems as described above, it includes a carbon veil and a carbon structure bound on the carbon veil, and the carbon veil is composed of an acrylic acid-based binder containing carboxylic acid and a phenolic resin. There is provided a carbon paper applied to a gas diffusion layer of a fuel cell, characterized in that the protrusion of carbon fibers from the surface is suppressed by using a dissolved phenol impregnating solution.

Carbon paper according to an embodiment of the present invention is made by impregnating a carbon veil in a phenol-impregnated solution prepared by adding an acrylic acid-based binder containing an appropriate ratio of carboxylic acid to easily remove the carbon fibers protruding from the surface of the carbon veil. In particular, it is possible to improve the gas permeability by allowing a uniform impregnated film to be formed on the carbon veil through the acrylic acid-based binder.

In addition, by adjusting the ratio of the carboxylic acid contained in the acrylic acid binder and the content of the acrylic acid binder mixed with the phenol-impregnated liquid, the compression ratio of the produced carbon paper can be adjusted to be suitable for the thin film type gas diffusion layer, through which durability and can be easily applied to the thin-film gas diffusion layer of the fuel cell to increase the performance.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be.

1 is a flowchart illustrating a method of manufacturing carbon paper according to an embodiment of the present invention.
2 is a cross-section of a carbon paper to which 10 parts by weight of an acrylic acid binder having a carboxylic acid ratio of 10% according to Example 1 of the present invention is applied, taken with a scanning electron microscope (SEM).
3 is a cross-section of carbon paper to which 10 parts by weight of an acrylic acid binder having a carboxylic acid ratio of 7% according to Comparative Example 2 of the present invention is applied, taken by SEM.
4 is a cross-section of carbon paper to which 5 parts by weight of an acrylic acid binder having a carboxylic acid ratio of 25% according to Example 4 of the present invention is applied, taken by SEM.
5 is a cross-section of carbon paper to which 3 parts by weight of an acrylic acid binder having a carboxylic acid ratio of 25% according to Comparative Example 4 of the present invention is applied, taken by SEM.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

DETAILED DESCRIPTION The detailed description set forth below in conjunction with the appended drawings is intended to describe exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced.

In order to clearly explain the present invention in the drawings, parts not related to the description may be omitted, and the same reference numerals may be used for the same or similar components throughout the specification.

In an embodiment of the present invention, expressions such as “or” and “at least one” may indicate one of the words listed together, or a combination of two or more.

1 is a flowchart illustrating a method of manufacturing carbon paper according to an embodiment of the present invention.

1, the carbon paper according to an embodiment of the present invention, the step of preparing a phenol-impregnated liquid mixed with an acrylic acid-based binder (S110), the step of impregnating the carbon veil in the phenol-impregnated liquid (S120), impregnated It may include drying and curing the carbon veil (S130), carbonizing the cured carbon veil (S140) and graphitizing the carbonized carbon veil (S150).

The carbon paper produced according to an embodiment of the present invention is manufactured by applying a phenol impregnating solution containing an acrylic acid binder in an appropriate ratio, so that the carbon fibers protruding from the surface of the carbon veil can be easily removed, and the gas It is possible to improve the permeability, and it can be easily applied to a thin-film gas diffusion layer for a fuel cell to increase the performance.

Specifically, in the step of preparing the phenol-impregnated liquid in which the acrylic acid-based binder is mixed (S110), a phenolic resin and an acrylic acid-based binder are added to alcohol to prepare a phenol-impregnated liquid.

In this case, the phenol-impregnated solution prepared in this embodiment can be prepared by mixing ethanol, which is an alcohol-based solvent, a phenol resin, graphite powder, and an acrylic acid-based binder.

As an example, the phenol impregnating solution may be composed of 55 to 90 wt% of ethanol, 2 to 10 wt% of a phenolic resin, 3 to 15 wt% of graphite powder, and 5 to 20 wt% of an acrylic acid binder.

Here, the phenol resin is a thermosetting resin used for manufacturing carbon paper, and has an advantage of high carbon yield after carbonization process.

These phenolic resins can be used by mixing one or more types that are soluble in alcohol, for example, at least one of a novolak-based or a resol-based resin can be selectively used.

In addition, the acrylic acid-based binder serves to bind the carbon fibers of the carbon veil impregnated with the phenol-impregnated liquid, and the graphite powder may be used as a carbide to improve electrical conductivity.

At this time, various adhesive materials capable of binding the carbon fibers of the carbon veil may be applied to the binder mixed with the phenol-impregnated solution. Carbon paper with improved compressibility and gas permeability can be manufactured only when an acrylic acid-based binder of an appropriate ratio is applied as in the embodiment.

In addition, the acrylic acid binder binds the carbon fibers protruding from the surface of the carbon veil so that the surface of the carbon veil can be formed flat, and a uniform impregnation film can be formed from the surface to the inside of the carbon veil to increase gas permeability can contribute to making

Such an acrylic acid-based binder, polyacrylic acid or styrene (Styrene), methyl methacrylate (Methylmethacrylate), ethyl methacrylate (Ethylmethacrylate), n- butyl methacrylate (n-Butylmethacrylate), isobutyl methacrylate acrylate (iso-Butylmethacrylate), t-butyl methacrylate (t-Butylmethacrylate), vinyl chloride (Vinylchloride), vinyl acetate (Vinylacetate), acrylonitrile (Acrylonitrile), 2-ethylhexyl methacrylate (2- Ethylhexylmethacrylate, Laurylmethacrylate, Methylacrylate, Ethylacrylate, n-Butylacrylate, iso-Butylacrylate, 2-ethyl Copolymerization of at least one selected raw material capable of forming a copolymer with acrylic acid such as 2-Ethylhexylacrylate, ethylene, octadecylmethacrylate, and acrylamide A copolymer binder may be applied.

Here, it is preferable to apply an acrylic acid-based copolymer rather than polyacrylic acid to control the compression ratio of carbon paper and improve gas permeability.

In addition, the acrylic acid-based binder can be selected according to the compression ratio and gas permeability of the target carbon paper, and it is possible to use one type or a mixture of two or more types.

In addition, when carbon paper is manufactured by applying a binder having a high carboxylic acid ratio in the acrylic acid binder, the gas permeability (vertical and horizontal gas permeability) of the carbon paper can be increased, and the effect of removing the protruding fibers compared to the same amount of binder is reduced. Excellent, it is possible to obtain the effect of removing the protruding fibers with a smaller amount of binder input compared to the conventional one.

In addition, in the process of manufacturing carbon paper, when the binder content is low, the compression ratio of the carbon paper increases, and when the binder content is high, the compression ratio decreases. There is a disadvantage in that the porosity is lowered and the gas permeability is lowered.

In this case, in the case of carbon paper applied to the thin-film gas diffusion layer of the fuel cell, it is possible to contribute to the improvement of the performance of the fuel cell by appropriately adjusting the compression ratio.

Accordingly, in this embodiment, a phenol-impregnated solution is prepared by adding an appropriate amount of an acrylic acid-based binder containing an appropriate ratio of carboxylic acid, and carbon paper is manufactured using the phenol-impregnated solution thus prepared, thereby suppressing the protruding fibers from the surface. Carbon paper with excellent gas permeability can be manufactured by increasing the impregnation uniformity while still being, and the compression rate of carbon paper can be adjusted to appropriately lower, ensuring durability and can be easily applied to a thin-film gas diffusion layer of a fuel cell.

As a preferred example, in this embodiment, 5 to 20 parts by weight of an acrylic acid binder containing carboxylic acid in a ratio of 10 to 50% is added to 100 parts by weight of a phenol-impregnated solution to prepare a phenol-impregnated solution, and the phenol-impregnated solution is Carbon paper having excellent gas permeability and suitable for a thin-film gas diffusion layer can be manufactured by using it.

Next, in the step (S120) of impregnating the carbon veil in the phenol impregnating liquid, the carbon veil may be impregnated in the prepared phenol impregnating liquid.

Carbon veil can be manufactured through a wet-laid manufacturing process by dispersing carbon fibers in water, and electrical properties can be improved only when carbon fibers are well cultured in two dimensions.

Recently, as the gas diffusion layer of the fuel cell is thinned, the thickness of the carbon veil becomes thinner compared to the length of the carbon fibers constituting the carbon veil. When the gas diffusion layer is prepared after coating the microporous layer without it, and this is applied to a fuel cell, the membrane electrode assembly (at least one of the catalyst layer, the electrolyte layer, and the gas diffusion layer) is penetrated by the protruding carbon fiber. It may cause physical damage and act as a cause to deteriorate the durability and performance of the fuel cell.

Accordingly, in the present embodiment, in the process of impregnating the carbon veil in the phenol impregnating liquid, the acrylic acid-based binder contained in the phenol impregnating liquid is impregnated with the carbon veil to coat the surface of the carbon veil, and thereby The carbon fibers protruding from the surface can be arranged in a horizontal direction to form a flat surface, and the durability and performance of the fuel cell can be improved by solving the problems caused by the carbon fibers protruding from the surface as described above. .

Next, in the step of drying and curing the impregnated carbon veil (S130), the remaining solvent may be dried in the first impregnated carbon veil, and the dried carbon veil may be cured.

In this case, preferably, the impregnated carbon bale may be dried at 70 to 100° C. for several minutes, and then cured at 150 to 200° C. for several minutes.

Next, in the step of carbonizing the cured carbon veil (S140), the cured carbon veil may be carbonized in an inert gas atmosphere.

Specifically, in order to block the combustion of the phenol resin, carbonization may be performed using nitrogen or argon gas, which is an inert gas, and preferably, carbonization may be performed at 700 to 900° C. for several tens of minutes.

Subsequently, in the step of graphitizing the carbonized carbon veil (S150), the carbonized carbon veil may be graphitized in an inert gas atmosphere.

In this case, the graphitization process may be performed using nitrogen gas or argon gas, and the temperature of the graphitization process may be formed at 2000° C. or higher.

As described above, in the carbon paper according to the present embodiment, the carbon veil is impregnated with a phenol-impregnated solution prepared by adding an acrylic acid-based binder containing carboxylic acid to easily remove the carbon fibers protruding from the surface of the carbon veil. This can be done, and the compression rate can be reduced, and in particular, it can contribute to increasing the gas permeability by forming a uniform impregnated film on the carbon veil through the acrylic acid-based binder.

Furthermore, by controlling the ratio of carboxylic acid contained in the acrylic acid binder and the content of the acrylic acid binder mixed in the phenol impregnating solution, durability can be secured and the compressibility of the produced carbon paper can be adjusted to be suitable for the thin film type gas diffusion layer. .

Hereinafter, carbon paper prepared according to a preferred embodiment and a comparative example of the present invention will be described.

However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any sense.

[Example 1]

Weigh 5 g of phenol resin, 8 g of graphite powder, 10 g of butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 10%, and 77 g of ethanol in a paste mixer container, and stir for 10 minutes under the conditions of revolution of 1000 RPM and rotation of 1000 RPM to obtain a phenol-impregnated solution. prepared.

Next, a carbon veil having an average length of 9 mm and a polyvinyl alcohol (PVA) binder containing 10 wt% of carbon fibers was impregnated in the phenol impregnating solution, and then the impregnated carbon bale was dried at 80° C. for 5 minutes, 180 It was cured at ℃ for 5 minutes, carbonized at 900℃ in nitrogen atmosphere for 1 hour, and graphitized at 2000℃ for 1 hour to prepare carbon paper.

[Example 2]

Carbon paper was prepared in the same manner as in Example 1, except that 10 g of a butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 25% was added.

[Example 3]

Carbon paper was prepared in the same manner as in Example 1, except that 10 g of a butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 50% was added.

[Example 4]

Carbon paper was prepared in the same manner as in Example 1, except that 82 g of ethanol and 5 g of a butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 25% were added.

[Example 5]

Carbon paper was prepared in the same manner as in Example 1, except that 67 g of ethanol and 20 g of a butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 25% were added.

[Comparative Example 1]

Carbon paper was prepared in the same manner as in Example 1, except that 87 g of ethanol was added and a separate binder was not added.

[Comparative Example 2]

Carbon paper was prepared in the same manner as in Example 1, except that 10 g of a butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 7% was added.

[Comparative Example 3]

Carbon paper was prepared in the same manner as in Example 1, except that 10 g of a butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 60% was added.

[Comparative Example 4]

Carbon paper was prepared in the same manner as in Example 1, except that 84 g of ethanol and 3 g of a butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 25% were added.

[Comparative Example 5]

Carbon paper was prepared in the same manner as in Example 1, except that 57 g of ethanol and 30 g of a butyl methacrylate acrylic acid copolymer binder having a carboxylic acid ratio of 25% were added.

The gas permeability and compressibility of the carbon paper prepared according to Examples 1 to 5 and Comparative Examples 1 to 5 were measured in the following manner.

1) Gas permeability

1-1) Horizontal gas permeability

The horizontal gas permeability was measured using CPRT-10, and the upper plate of the tester was blocked and there was a hole through which the gas was supplied in the center of the lower plate. .

1-2) Vertical gas permeability

The vertical gas permeability was measured using CPRT-10 to measure the degree of gas permeation from the bottom to the top of the uncompressed specimen, and was measured after sealing to prevent horizontal gas permeation.

2) Compression rate

Carbon paper was compressed with a load of 1 MPa to measure the rate of decrease in thickness change.

Meanwhile, the results of measuring the presence or absence of protruding fibers, gas permeability, and compressibility of the carbon paper prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 1 below.

In addition, FIGS. 2 to 5 are SEM cross-sections of carbon papers according to Example 1 and Comparative Example 2 and Example 4 and Comparative Example 4 of the present invention, respectively.

division carboxylic acid
ratio bookbinder
input ratio protruding fibers
(The presence or absence) Gas permeability (㎡) compressibility
(%) horizontality Perpendicular Example 1 10% 10g radish

34.1 Example 2 25% 10g radish

32.1 Example 3 50% 10g radish

31.1 Example 4 25% 5g radish

39.6 Example 5 25% 20g radish

27.5 Comparative Example 1 - - you

44.8 Comparative Example 2 7% 10g you

35.3 Comparative Example 3 60% 10g radish

30.5 Comparative Example 4 25% 3g you

40.2 Comparative Example 5 25% 30g radish

22.6

As shown in Table 1, in the case of the carbon paper according to the embodiment of the present invention, compared to Comparative Example 1 in which the acrylic acid-based binder containing carboxylic acid was not applied, the carbon fiber did not protrude, and the compressibility and gas permeability were A significant improvement can be seen.

On the other hand, the acrylic acid binder of the present invention may preferably contain 10 to 50% of carboxylic acid in the acrylic acid binder.

When the proportion of carboxylic acid is less than 10%, the binding effect for suppressing the protrusion of carbon fibers is insufficient, and when the proportion of carboxylic acid exceeds 50%, improvement in compressibility is limited due to the viscosity of the binder, whereas gas Transmittance can be greatly reduced.

Referring to Table 1, in the case of Example 1 to which the acrylic acid-based binder having a carboxylic acid ratio of 10% was applied, compared to Comparative Example 2 to which the acrylic acid-based binder having a carboxylic acid ratio of 7% was applied, the carbon fiber It can be seen that the protrusion was suppressed, the compression ratio was reduced and the gas permeability was increased.

In addition, in the case of Comparative Example 3 to which the acrylic acid-based binder having a carboxylic acid ratio of 60% is applied, when compared with Example 3 to which the acrylic acid-based binder having a carboxylic acid ratio of 50% is applied, a slight improvement in the compressibility is confirmed. It can be seen that the gas permeability is greatly reduced.

In addition, in the phenol-impregnated liquid of the present invention, the acrylic acid-based binder including carboxylic acid may be mixed in an amount of 5 to 20 parts by weight based on 100 parts by weight of the phenol-impregnated liquid.

When the acrylic acid-based binder is mixed in less than 5 parts by weight, the binding effect of suppressing the protrusion of carbon fibers is insufficient, and when the acrylic acid-based binder exceeds 20 parts by weight, the phenol-impregnated liquid is excessively impregnated into the carbon veil and the gas permeability can be significantly reduced.

Referring to Table 1, in the case of Example 4 in which the acrylic acid-based binder was mixed in 5 parts by weight, compared to Comparative Example 4 in which the acrylic acid-based binder was mixed in 3 parts by weight, the protrusion of the carbon fibers was suppressed, the compressibility was reduced, and the gas It can be seen that the transmittance is increased.

In addition, in the case of Comparative Example 5 in which the acrylic acid-based binder was mixed in 30 parts by weight, when compared with Example 5 in which the acrylic acid-based binder was mixed in 20 parts by weight, a slight improvement in the compressibility was confirmed, but it was confirmed that the gas permeability was greatly reduced. .

In addition, referring to FIGS. 2 and 4, in the case of Example 1 to which an acrylic acid binder having a carboxylic acid ratio of 10% is applied and Example 4 to which 5 parts by weight of an acrylic acid binder is applied, no protruding carbon fibers are identified, It can be seen that the surface of the carbon paper is formed flat.

On the other hand, referring to FIGS. 3 and 5 , in Comparative Example 2 to which an acrylic acid binder having a carboxylic acid ratio of 7% is applied and Comparative Example 4 to which 3 parts by weight of an acrylic acid binder is applied, a number of protruding carbon fibers are identified and And it can be confirmed that the surface of the carbon paper is not formed flat.

As described above, in the carbon paper according to an embodiment of the present invention, the carbon veil is impregnated with a phenol-impregnated solution prepared by adding an acrylic acid-based binder containing an appropriate ratio of carboxylic acid, and protrudes from the surface of the carbon veil. It is possible to easily remove the carbon fiber, and in particular, it is possible to form a uniform impregnated film on the carbon veil through the acrylic acid binder, thereby improving the gas permeability.

In addition, by adjusting the ratio of the carboxylic acid contained in the acrylic acid binder and the content of the acrylic acid binder mixed with the phenol impregnating solution, the compression ratio of the produced carbon paper can be adjusted to be suitable for the thin film type gas diffusion layer, through which durability and can be easily applied to the thin-film gas diffusion layer of the fuel cell to increase the performance.

The embodiments of the present invention disclosed in the present specification and drawings are merely provided for specific examples to easily explain the technical content of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention.

Therefore, the scope of the present invention should be construed as including all changes or modifications derived based on the technical idea of the present invention in addition to the embodiments disclosed herein are included in the scope of the present invention.

Claims (9)

preparing a phenol-impregnated solution in which an acrylic acid-based binder containing carboxylic acid and a phenol resin are dissolved;
impregnating the carbon veil in the phenol-impregnated liquid and drying it to bind the carbon fibers protruding from the surface of the carbon veil to suppress protrusion from the surface; and
A method for producing carbon paper applied to a gas diffusion layer of a fuel cell, comprising the steps of curing, carbonizing and graphitizing the dried carbon veil.
The method of claim 1,
The acrylic acid-based binder,
A method for producing carbon paper applied to the gas diffusion layer of a fuel cell, wherein 10 to 50% of the carboxylic acid is included.
The method of claim 1,
The acrylic acid-based binder,
5 to 20 parts by weight based on 100 parts by weight of the phenol-impregnated solution, a method for producing carbon paper applied to the gas diffusion layer of a fuel cell.
The method of claim 1,
The acrylic acid-based binder,
Styrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, vinyl chloride, vinyl acetate, acrylonitrile, 2-ethylhexyl methacrylate , lauryl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, ethylene, octadecyl methacrylate, a copolymer with at least one of acrylamide A method for producing carbon paper applied to a fuel cell gas diffusion layer, which is a copolymer binder to be formed.
[Claim 5] Carbon paper applied to the gas diffusion layer of a fuel cell manufactured by using any one of the manufacturing methods of any one of claims 1 to 4.
carbon veil; and
It includes a carbon structure bound on the carbon veil,
The carbon veil is carbon paper applied to the fuel cell gas diffusion layer, characterized in that the protrusion of carbon fibers from the surface is suppressed by using an acrylic acid-based binder containing carboxylic acid and a phenol impregnating solution in which the phenol resin is dissolved.
7. The method of claim 6,
The acrylic acid-based binder,
A carbon paper applied to the gas diffusion layer of a fuel cell, wherein the carboxylic acid is contained in an amount of 10 to 50%.
7. The method of claim 6,
The acrylic acid-based binder,
Carbon paper applied to the fuel cell gas diffusion layer, which is mixed in an amount of 5 to 20 parts by weight based on 100 parts by weight of the phenol-impregnated solution.
In the phenol impregnation solution for carbon paper applied to the gas diffusion layer and comprising a carbon veil and a carbon structure bound to the carbon veil,
an acrylic acid-based binder containing carboxylic acid; and
containing phenolic resin,
The acrylic acid-based binder suppresses the protrusion of carbon fibers from the surface of the carbon veil and increases gas permeability through uniform impregnation, a phenol impregnation solution for carbon paper applied to the gas diffusion layer of a fuel cell.

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