KR20210014904A - Release film for electrolyte membrane and manufacturing method thereof - Google Patents

Abstract

The present invention relates to release paper for manufacturing an electrolyte membrane, a manufacturing method thereof, and a method for manufacturing an electrolyte membrane using the release paper. Only the electrolyte membrane can be smoothly peeled off by adjusting the weight% of components of a polymer solution included in a release agent layer, so that the degree of contamination of the electrolyte membrane can be reduced. In addition, even if the release agent layer is left, since the release agent layer contains an antioxidant, the electrolyte membrane can be peeled off smoothly, and durability such as chemical resistance and heat resistance of the electrolyte membrane can be increased.

Description

Release film for electrolyte membrane and manufacturing method thereof {Release film for electrolyte membrane and manufacturing method thereof}

The present invention relates to a release paper for manufacturing an electrolyte membrane, a method for manufacturing the same, and a method for manufacturing an electrolyte membrane using the release paper.

A fuel cell is a power generation system that directly converts the chemical reaction energy of hydrogen and oxygen contained in hydrogen or hydrocarbon-based substances such as methanol, ethanol, and natural gas into electrical energy. Fuel cells are classified into phosphoric acid type fuel cells, molten carbonate type fuel cells, solid oxide type fuel cells, polymer electrolyte type or alkaline type fuel cells, etc., depending on the type of electrolyte used. Each of these fuel cells basically operates on the same principle, but the types of fuels used, operating temperatures, catalysts, electrolytes, etc. are different from each other.

A fuel cell stack that substantially generates electricity in such a fuel cell generally has a structure in which several to tens of unit cells composed of a membrane electrode assembly (MEA) and a separator (or bipolar plate) are stacked. The electrode membrane assembly may include an electrolyte membrane, an anode electrode (called a fuel electrode or an anode) and a cathode electrode (called a cathode or a cathode) attached to both surfaces of the electrolyte membrane.

Meanwhile, the electrolyte membrane provided between the electrodes can be obtained by coating a polymer solution on a sheet material, drying, and then peeling. At this time, the sheet material should not have a physicochemical reaction when the polymer solution is dried, and should be well separated from the sheet material when the electrolyte membrane is peeled from the sheet. However, when the dried electrolyte membrane is peeled from the sheet, there is a problem that a release agent, which is a sheet material, comes out.

Korean Patent Registration 10-1926910

The present invention is to solve the above problems, the specific purpose is as follows.

An object of the present invention is to provide a release paper that facilitates peeling of an electrolyte membrane.

In addition, an object of the present invention is to provide a method of manufacturing a release paper that facilitates peeling of the electrolyte membrane.

In addition, an object of the present invention is to provide a method of manufacturing an electrolyte membrane in which a peeling interface is different depending on the composition component of a release agent layer included in a release paper.

The object of the present invention is not limited to the object mentioned above. The object of the present invention will become more apparent from the following description, and will be realized by the means described in the claims and combinations thereof.

Release paper according to an embodiment of the present invention sheet layer; And a release agent layer provided on the sheet layer and including an antioxidant.

The sheet layer is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyoxymethylene (POM), and combinations thereof. Can include.

The release agent layer may further include a polymer solution.

The polymer solution may include perfluorosulfonic acid (PFSA), alcohol-based, and water.

The alcohol system may be selected from the group consisting of methanol, ethanol, propanol, butanol, and combinations thereof.

The antioxidant may be selected from the group consisting of cerium (Ce) salt, cerium (Ce) oxide, manganese (Mn) salt, manganese (Mn) oxide, vanadium (V) salt, vanadium (V) oxide, and combinations thereof. have.

The release agent layer may include 100 parts by weight of PFSA and 5 to 20 parts by weight of the antioxidant.

The release agent layer may have a thickness of 0.02 to 0.5 μm.

In addition, a method of manufacturing a release paper according to an embodiment of the present invention includes preparing a sheet layer and a release agent, coating a release agent on the sheet layer, and drying the coated release agent.

The release agent may include a polymer solution and an antioxidant.

The polymer solution may contain 10 to 30% by weight of perfluorosulfonic acid (PFSA) and 70 to 90% by weight of a solvent.

The solvent may contain 20 to 40% by weight of alcohol and 60 to 80% by weight of water.

The drying may include natural drying or heat treatment after drying.

In the step of heat treatment after drying, the drying may have a temperature of 60 to 120°C, and the heat treatment may have a temperature of 190 to 210°C.

In addition, a method of manufacturing an electrolyte membrane according to an embodiment of the present invention includes preparing a release paper and an electrolyte membrane solution prepared by the above method, coating an electrolyte membrane solution on the release paper, drying the coated electrolyte membrane solution, and And performing heat treatment and peeling the electrolyte membrane.

The drying may be performed at a temperature of 60 to 120°C, and the heat treatment may be performed at a temperature of 120 to 200°C.

In the peeling, the electrolyte membrane or the electrolyte membrane including the release agent layer may be peeled off.

The electrolyte membrane is peeled off from a release paper prepared using a polymer solution containing 10 to 30% by weight of perfluorosulfonic acid (PFSA), 35 to 54% by weight of alcohol, and 28 to 45% by weight of water. It can be peeled off.

The electrolyte membrane including the release agent layer is peeled off from the release paper prepared by using a polymer solution containing 10 to 30% by weight of PFSA, 14 to 36% by weight of alcohol, and 42 to 72% by weight of water. Can be.

According to the present invention, only the electrolyte membrane can be smoothly peeled by adjusting the weight% of the component of the polymer solution contained in the release agent layer, thereby reducing the degree of contamination of the electrolyte membrane. In addition, even if the release agent layer is buried, since the release agent layer contains an antioxidant, the electrolyte membrane can be removed smoothly, and durability such as chemical resistance and heat resistance of the electrolyte membrane can be increased.

The effects of the present invention are not limited to the effects mentioned above. It should be understood that the effects of the present invention include all effects that can be inferred from the following description.

1 is a cross-sectional view schematically showing a release paper according to the present invention.
2 is a flowchart showing a method of manufacturing a release paper according to the present invention.
3 is a flow chart showing a method of manufacturing an electrolyte membrane according to the present invention.
4 is a cross-sectional view schematically showing a state in which an electrolyte membrane is coated on a release paper according to the present invention.
5 is a cross-sectional view showing that only the electrolyte membrane is peeled off after coating the electrolyte membrane on the release paper according to Example 1 of the present invention.
6 is a cross-sectional view showing that the electrolyte membrane including the release agent layer is peeled off after coating the electrolyte membrane on a release paper according to Example 2 of the present invention.

The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments related to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed contents may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance the possibility of being added. Further, when a part such as a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where the other part is "directly above", but also the case where there is another part in the middle. Conversely, when a part such as a layer, a film, a region, or a plate is said to be "under" another part, this includes not only the case where the other part is "directly below", but also the case where there is another part in the middle.

Unless otherwise specified, all numbers, values, and/or expressions expressing quantities of ingredients, reaction conditions, polymer compositions, and formulations used herein are those that occur in obtaining these values, among other things essentially. Since they are approximations that reflect the various uncertainties of the measurement, it should be understood as being modified in all cases by the term "about". In addition, when numerical ranges are disclosed herein, these ranges are continuous and, unless otherwise indicated, include all values from the minimum value of this range to the maximum value including the maximum value. Furthermore, when this range refers to an integer, all integers from the minimum value to the maximum value including the maximum value are included, unless otherwise indicated.

1 is a cross-sectional view schematically showing a release paper 1 according to the present invention . Referring to this, the release paper includes a sheet layer 10 and a release agent layer 20 provided on the sheet layer.

Sheet layer

The sheet layer 10 according to an embodiment of the present invention is not particularly limited as long as the release agent layer 20 to be described later can be provided on the sheet layer.

The sheet layer according to the present invention is a group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyoxymethylene (POM), and combinations thereof It may be selected from, and preferably may be polyimide (PI).

Release agent layer

The release agent layer 20 according to an embodiment of the present invention is provided on the sheet layer and includes a polymer solution and an antioxidant.

The polymer solution according to the present invention may include perfluorosulfonic acid (PFSA), alcohol-based, and water.

Specifically, it may be a composition selected from the group consisting of surfactants, polyvinylidene difluoride (PVDF), perfluorosulfonic acid (PFSA), and combinations thereof in the polymer solution according to the present invention. There may be, preferably PVDF.

In addition, the alcohol system according to the present invention may be selected from the group consisting of methanol, ethanol, propanol, and combinations thereof, and preferably propanol.

In addition, the antioxidant according to the present invention is composed of cerium (Ce) salt, cerium (Ce) oxide, manganese (Mn) salt, manganese (Mn) oxide, vanadium (V) salt, vanadium (V) oxide, and combinations thereof. It may be selected from the group, preferably a cerium-based cerium (Ce) salt or a cerium (Ce) oxide.

The composition of the antioxidant contained in the release agent layer according to the present invention may vary depending on the equivalent amount of PFSA. Preferably, it may contain 5 to 20 parts by weight of an antioxidant based on 100 parts by weight of PFSA. If the weight of the antioxidant is less than 5, it has a disadvantage that it cannot perform the role of the release agent.If it exceeds 20, the ionic conductivity of the electrolyte membrane decreases when a large amount of the antioxidant moves to the surface of the electrolyte membrane during the release of the electrolyte membrane, thereby reducing the performance of the fuel cell. There is a drawback of reducing it.

In addition, when the release agent layer according to the present invention is peeled off after the release agent layer is included in the electrolyte layer by adding an additive, various properties may be imparted to the electrolyte layer. For example, it is possible to increase the hydrophilicity in the electrolyte layer by adding a filler that has a hydrophilic role.

The release agent layer according to the present invention may be coated with a thin thickness on the sheet layer, and preferably may be coated with a thickness of 0.02 to 0.5 μm. If it is less than 0.02μm, there is a problem that the role of the release agent cannot be performed, and if it exceeds 0.5μm, when a large amount of antioxidant moves to the surface of the electrolyte membrane when the electrolyte membrane is released, the ionic conductivity of the electrolyte membrane decreases, thereby reducing the performance of the fuel cell. There is a problem.

Figure 2 is a flow chart showing a release paper (1) manufacturing method according to the present invention . Referring to this, it includes preparing a sheet layer and a release agent (S10), coating a release agent on the sheet layer (S20), and drying the coated release agent (S30).

Preparing the sheet layer and the release agent (S10) is a step of preparing basic materials for release paper. The sheet layer is preferably prepared from the material of the sheet layer described above. In addition, the step of preparing a release agent is preferably to prepare a material included in the release agent layer described above. Specifically, the release agent included in the release agent layer according to the present invention includes a polymer solution and an antioxidant, and the polymer solution includes perfluorosulfonic acid (PFSA), alcohol and water. The alcohol system may be selected from the group consisting of methanol, ethanol, propanol, and combinations thereof, and preferably, propanol. The antioxidant may be selected from the group consisting of cerium (Ce) salt, cerium (Ce) oxide, manganese (Mn) salt, manganese (Mn) oxide, vanadium (V) salt, vanadium (V) oxide, and combinations thereof. And, preferably, it may be a cerium-based cerium (Ce) salt or cerium (Ce) oxide.

At this time, if there is a lot of water, it is important to adjust the ratio of water and alcohol because it may cause a problem to be lifted from the sheet layer when the release agent is dried later. Therefore, the polymer solution according to the present invention preferably contains 10 to 30% by weight of perfluorosulfonic acid (PFSA) and 70 to 90% by weight of a solvent. If it is less than 10% by weight of PFSA, it is difficult to form a release agent film, and if it exceeds 30% by weight, it is difficult to form a thin film because the viscosity of the release agent is high. In addition, the solvent may include 20 to 40% by weight of alcohol and 60 to 80% by weight of water in 70 to 90% by weight. In this case, if the amount is less than 20% by weight of alcohol, it is difficult to form a release agent film, and if it exceeds 40% by weight, the viscosity of the release agent is high, making it difficult to form a thin film. In addition, if the water is less than 60% by weight, the viscosity of the release agent is difficult to form a thin film, and if it exceeds 80% by weight, it is difficult to form a film of the release agent.

The step of coating the release agent (S20) is a step of coating the release agent prepared according to the present invention on the sheet layer prepared according to the present invention. The coating may be selected from the group consisting of gravure coating, spin coating, bar coating, spray coating, and combinations thereof, preferably spin coating.

The step of drying the coated release agent (S30) is a step of preparing a release paper while drying the coated release agent to form a release agent layer.

Specifically, drying in the method of manufacturing a release agent according to the present invention may include natural drying or heat treatment after drying. The natural drying may be performed at room temperature (23 ~ 27 ℃). In addition, in the step of heat treatment after drying, the drying temperature may be 60 to 120°C, and the heat treatment may be 190 to 210°C. If the drying temperature is less than 60°C, there is a disadvantage in that volatilization of the solvent is not easy, and when the drying temperature exceeds 120°C, an unstable surface may be formed due to rapid volatilization of the solvent. In addition, when the heat treatment temperature is less than 120°C, there is a disadvantage in that the formation of the morphology of the electrolyte membrane may be unstable, and when it exceeds 210°C, physical deterioration of the PFSA occurs.

A feature of the present invention is that the polymer solution contained in the release agent is 10 to 30% by weight of perfluorosulfonic acid (PFSA), 35 to 54% by weight of alcohol, and 28 to 45% by weight of the total polymer solution. In the case of manufacturing a release paper by heat treatment after drying under the above conditions, only the electrolyte membrane can be peeled off when the electrolyte membrane is manufactured using the release paper, thereby reducing the degree of contamination of the electrolyte membrane.

In addition, the polymer solution contained in the release agent is contained in 10 to 30% by weight of PFSA, 14 to 36% by weight of alcohol, and 42 to 72% by weight of water, among the total polymer solution weight%, and naturally dried under the above conditions to prepare a release paper. In this case, when the electrolyte membrane is manufactured using the release paper, the electrolyte membrane including the release agent layer containing antioxidants, etc. can be peeled off, so that the electrolyte membrane can be removed smoothly and at the same time, the durability such as chemical resistance and heat resistance of the electrolyte membrane can be increased. I can.

3 is a flow chart showing a method of manufacturing an electrolyte membrane 30 according to the present invention . Referring to this, the step of preparing a release paper and electrolyte membrane solution prepared by the manufacturing method according to the present invention (S40), coating the electrolyte membrane solution on the release paper (S50), drying and heat treatment of the coated electrolyte membrane solution And a step (S60) of removing the electrolyte membrane (S70).

The release paper according to the present invention is prepared according to the manufacturing method described above. The electrolyte membrane solution according to the present invention is not particularly limited as long as it includes a conventional material for manufacturing an electrolyte membrane used in a membrane-electrode assembly (MEA), and may be, for example, Nafion. In addition, coating the electrolyte membrane solution on the release paper is not particularly limited as long as it is coated by a conventional method for preparing an electrolyte membrane. In the drying and heat treatment of the electrolyte membrane solution coated according to the present invention, the drying temperature may be 60 to 120°C, and the heat treatment temperature may be 120 to 200°C. When the drying temperature is less than 60° C., there is a disadvantage that volatilization of the solvent is not easy, and when it exceeds 120° C., an unstable surface may be formed due to rapid volatilization of the solvent. In addition, when the heat treatment temperature is less than 120°C, the formation of the morphology of the electrolyte membrane may be unstable, and when the heat treatment temperature exceeds 200°C, physical deterioration of the PFSA occurs.

Separating the electrolyte membrane according to the present invention is performed while the electrolyte membrane is provided on the release paper as shown in FIG. 4. At this time, the peeling interface may vary depending on the composition ratio of the polymer solution contained in the release paper and the drying process.

Specifically, the polymer solution is included in 10 to 30% by weight of perfluorosulfonic acid (PFSA), 35 to 54% by weight of alcohol, and 28 to 45% by weight of water, among the total polymer solution weight%, In the case of manufacturing a release paper by heat treatment after drying under the conditions of the release paper manufacturing method according to the present invention, when the electrolyte membrane is manufactured using the release paper, only the electrolyte membrane can be peeled off as shown in FIG.

In addition, the polymer solution is contained in 10 to 30% by weight of PFSA, 14 to 36% by weight of alcohol and 42 to 72% by weight of water, and naturally dried under the conditions in the release paper production method according to the present invention. In the case of manufacturing the release paper, as shown in FIG. 6, when the electrolyte membrane is manufactured using the release paper, the electrolyte membrane including the release agent layer containing an antioxidant, etc. can be peeled off, so that the electrolyte membrane can be removed smoothly and at the same time, the electrolyte. It can increase the durability such as chemical resistance and heat resistance of the membrane.

The present invention will be described in more detail through the following examples. The following examples are only examples to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

Example 1

(S10) The sheet layer was prepared with polyimide (PI), and as a release agent, 0.5 g of an antioxidant CeO ₂ ; As the polymer solution, 5 g of perfluorosulfonic acid (PFSA), 8 g of alcohol-based propanol (NPA), and 12 g of water, PFSA 20% by weight, alcohol-based 32% by weight, and water 48% by weight Ready.

(S20, S30) The prepared release agent was coated on the sheet layer by spin coating. Thereafter, natural drying was performed at room temperature (25°C) to prepare a release paper.

Example 2

As compared with Example 1, the release agent was 0.5 g as an antioxidant; 5 g of perfluorosulfonic acid (PFSA) as a polymer solution, 10 g of alcohol-based, 10 g of water, 20% by weight of PFSA, 40% by weight of alcohol, and 40% by weight of water were prepared; And

A release paper was prepared in the same manner as in Example 1, except that the heat treatment after drying instead of natural drying was performed at a drying temperature of 60°C and a heat treatment temperature of 120°C.

Experimental Example-Electrolyte membrane separation interface change according to the composition of polymer solution

Release papers were prepared according to Examples 1 and 2, and each of the release papers was coated with an electrolyte membrane solution PFSA dispersion, dried at 60°C, and heat treated at 120°C. The interface result when peeled after that is as follows.

Specifically, in the case of Example 1, as shown in FIG. 5, the electrolyte membrane was peeled at the interface between the electrolyte membrane and the release agent layer, and it was confirmed that only the electrolyte membrane could be peeled off.

In addition, in the case of Example 2, as shown in FIG. 6, the electrolyte membrane was peeled at the interface between the release agent layer and the sheet layer, and it was confirmed that the electrolyte membrane including the release agent layer containing an antioxidant, etc. could be peeled off. .

That is, in the present invention, when the electrolyte membrane is peeled through a release paper prepared according to a change in the ratio of the solvent (alcohol-based: water) contained in the polymer solution and drying conditions, only the electrolyte membrane can be removed smoothly, thereby reducing the degree of contamination of the electrolyte membrane. In addition, even if the releasing agent layer is stained, since the releasing agent layer contains an antioxidant, the electrolyte membrane can be removed smoothly and durability such as chemical resistance and heat resistance of the electrolyte membrane can be increased.

1: Hyungji Lee
DESCRIPTION OF SYMBOLS 10 Sheet layer 20 Release agent layer 30 Electrolyte membrane

Claims (19)

Sheet layer; And
A release paper provided on the sheet layer and comprising a release agent layer containing an antioxidant. The method of claim 1,
The sheet layer is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyoxymethylene (POM), and combinations thereof. The release paper that includes. The method of claim 1,
The release agent layer is a release paper that further comprises a polymer solution. The method of claim 3,
The polymer solution is a release paper containing perfluorosulfonic acid (PFSA), alcohol-based and water. The method of claim 4,
The alcohol-based release paper is selected from the group consisting of methanol, ethanol, propanol, butanol, and combinations thereof. The method of claim 1,
The antioxidant is selected from the group consisting of cerium (Ce) salt, cerium (Ce) oxide, manganese (Mn) salt, manganese (Mn) oxide, vanadium (V) salt, vanadium (V) oxide, and combinations thereof Hyungji Lee. The method of claim 1,
The release agent layer is a release paper containing 100 parts by weight of PFSA and 5 to 20 parts by weight of the antioxidant. The method of claim 1,
The release agent layer is a release paper having a thickness of 0.02 ~ 0.5μm. Preparing a sheet layer and a release agent;
Coating a release agent on the sheet layer;
Method of producing a release paper comprising the step of drying the coated release agent. The method of claim 9,
The method of manufacturing a release paper containing the release agent and a polymer solution and an antioxidant. The method of claim 10,
The polymer solution is
10 to 30% by weight of perfluorosulfonic acid (PFSA);
A method for producing a release paper containing 70 to 90% by weight of a solvent. The method of claim 11,
The solvent is
20 to 40% by weight of alcohol;
A method for producing a release paper containing 80-60% by weight of water. The method of claim 9,
The drying method for producing a release paper comprising the step of natural drying or heat treatment after drying. The method of claim 13,
In the step of heat treatment after drying,
The drying is a temperature of 60 ~ 120 ℃, heat treatment is a method of manufacturing a release paper that the temperature is 190 ~ 210 ℃. Preparing a release paper and an electrolyte membrane solution prepared by the manufacturing method of any one of claims 9 to 14;
Coating an electrolyte membrane solution on the release paper;
Drying and heat treating the coated electrolyte membrane solution; And
An electrolyte membrane manufacturing method comprising the step of peeling the electrolyte membrane. The method of claim 15,
The drying is performed at a temperature of 60 to 120°C, and the heat treatment is performed at a temperature of 120 to 200°C. The method of claim 15,
The peeling is a method of manufacturing an electrolyte membrane in which the electrolyte membrane or the electrolyte membrane including the release agent layer is peeled. The method of claim 17,
Peeling of the electrolyte membrane is 10 to 30% by weight of perfluorosulfonic acid (PFSA); An electrolyte membrane manufacturing method wherein the electrolyte membrane is peeled from a release paper prepared using a polymer solution containing 35 to 54% by weight of alcohol and 28 to 45% by weight of water. The method of claim 17,
Peeling of the electrolyte membrane including the release agent layer is 10 to 30% by weight of PFSA; An electrolyte membrane manufacturing method in which the electrolyte membrane including the release agent layer is peeled from a release paper prepared using a polymer solution containing 14 to 36% by weight of alcohol and 42 to 72% by weight of water.

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