KR102492915B1 - Manufacturing method for film type carbon material with continuous skeleton structure - Google Patents

Abstract

The present invention relates to a method for manufacturing a film-type carbonaceous material having a continuous skeleton through a carbonization process after manufacturing a film having a continuous skeleton in which the structure of the epoxy resin does not collapse in the carbonization process by adding graphene to the epoxy resin, and the manufacturing method. It relates to a film-like carbon material having a continuous skeleton manufactured according to the method, wherein the film-like carbon material having a continuous skeleton can produce a film of a desired thickness, can form a porous carbon material into a film, and can add graphene and a continuous skeleton. As a result, electrical conductivity and charge mobility can be increased by porosity.

Description

Film type carbon material having continuous skeleton and manufacturing method thereof {Manufacturing method for film type carbon material with continuous skeleton structure}

The present invention relates to a method for manufacturing a film-type carbonaceous material having a continuous skeleton through a carbonization process after manufacturing a film having a continuous skeleton in which the structure of the epoxy resin does not collapse in the carbonization process by adding graphene to the epoxy resin, and the manufacturing method. It relates to a film-like carbon material having a continuous skeleton manufactured according to the present invention.

Graphene is a type of carbon nanoparticle called a new dream material, and has excellent properties such as high electrical conductivity, thermal conductivity, and high strength. Graphene is a structure in which six carbon atoms are gathered together to form a hexagonal honeycomb shape and are connected in a plate-like structure. Graphene is composed of a single layer, and a form in which these graphenes are stacked is graphite, which is commonly seen around. Graphite, also called graphite, is a good starting material for obtaining large quantities of graphene because of its low price. Graphene is produced from graphite. The simplest method is to separate graphite from graphite with scotch tape. A commonly used method is to obtain graphite by reducing chemically oxidized graphite and to form graphite on a metal substrate by chemical vapor deposition. There is a way to grow a pin. Since graphene thus obtained has high conductivity, it is widely used as a material for electronic devices and energy storage devices.

Epoxy resin is one of the very important cross-linked polymer materials due to its excellent physical properties such as strong adhesiveness, high tensile strength and toughness, high chemical/thermal stability, shape stability, excellent creep properties, and solvent resistance. In addition to these excellent properties, adhesives and coatings are used in various electric and electronic products/parts, aerospace, automobile, military, sporting goods/household goods, civil engineering/construction, and machinery due to their excellent process characteristics and economical price. , paints, laminated products, molded products, and molded products.

On the other hand, film-type carbon materials are a product group that is attracting attention in the era of the 4th industrial revolution, and many research groups at home and abroad have been making efforts to develop related technologies for the past several years. Carbon materials are polymers because of their advantages such as high conductivity, high surface area (2,630 m ² /g), light weight, high temperature stability, tunable pore structure, compatibility with composite materials, and relatively low cost. Research is being conducted focusing on carbon-based materials, graphene, and carbon nanotubes.

In this regard, U.S. Patent Publication No. 2020-0010633 discloses a carbon fiber having excellent moldability, heat resistance, and excellent mechanical properties such as tensile strength and compressive strength by mixing a specific epoxy resin component as an epoxy resin component within a specific range. Although an epoxy resin composition suitably used for a reinforced composite material is disclosed, a conventional material using an epoxy resin has a problem in that the polymer structure collapses at 700° C. or higher.

US Patent Publication No. 2020-0010633

In the prior art, when a carbonization process is performed at 700° C. or higher to make a continuous skeletal porous polymer into a carbon material, the polymer structure collapses and the carbon structure is not maintained. In addition, it is difficult to film a porous carbon material.

In order to solve this problem, the present invention is to prepare a film having a continuous skeleton in which the structure of the epoxy resin does not collapse in the carbonization process by adding graphene to the epoxy resin, and then to produce a film-like carbon material having a continuous skeleton through the carbonization process. It is intended to provide a manufacturing method and a film-like carbonaceous material having a continuous skeleton manufactured according to the manufacturing method.

In order to solve the above problem,

In one embodiment, the present invention comprises the steps of forming a carbon precursor by mixing an epoxy resin and graphene; preparing a carbon material precursor having a continuous skeleton by adding a pore forming agent to the carbon precursor; coating a carbon material precursor having a continuous backbone on a substrate coated with polyvinyl alcohol (PVA) and then covering another polyvinyl alcohol coated substrate to prepare a film-type carbon material precursor; and carbonizing the film-like carbonaceous material precursor by heat treatment.

The content of the graphene relative to the total content of the epoxy resin may be 1 to 5 wt%.

The pore forming agent may include a thermoplastic resin.

In the step of preparing the film-like carbonaceous material precursor, the carbonaceous material precursor having a continuous backbone may be coated on the substrate coated with polyvinyl alcohol to a thickness of 10 to 1,000 μm.

In the step of preparing the film-like carbonaceous material precursor, after coating the carbonaceous material precursor having the continuous backbone on the polyvinyl alcohol-coated substrate and then covering another polyvinyl alcohol-coated substrate, the film-like carbon thermally curing by heating the material precursor; Separating the film-like carbonaceous material precursor from the polyvinyl alcohol-coated substrate; And, it may be to further include the step of removing the pore forming agent.

The heat treatment may be to heat to 700 to 800 °C at a heating rate of 0.5 to 10 °C/min and then hold for 30 to 80 minutes.

The carbonization step may be carried out by supporting upper and lower portions of the film-like carbonaceous material precursor with an alumina substrate in order to maintain the film-like structure during the heat treatment.

In addition, in one embodiment, the present invention includes a film having a continuous skeleton including an epoxy resin and graphene, wherein the film having a continuous skeleton has a thickness of 10 to 1,000 μm. A type carbon material is provided.

The content of the graphene relative to the total content of the epoxy resin may be 1 to 5 wt%.

According to the present invention, the manufacturing method of a film-type carbonaceous material having a continuous skeleton is a film having a continuous skeleton in which micrometer-level pores are introduced without the structure of the epoxy resin being collapsed in the carbonization process at 700 ° C or higher by adding graphene to the epoxy resin. A type carbon material can be produced.

In addition, the film-like carbon material having a continuous skeleton prepared according to the above manufacturing method can produce a film of a desired thickness, and can increase electrical conductivity and porosity due to the addition of graphene and the continuous skeleton. .

1 is a schematic diagram showing a manufacturing method of a film-like carbonaceous material having a continuous skeleton according to the present invention.
2 is a schematic diagram showing a method for manufacturing a film type in the method for manufacturing a film type carbonaceous material having a continuous skeleton according to the present invention.
3 is a schematic diagram of a phase separation phenomenon for manufacturing a film-like carbonaceous material having a continuous skeleton according to the present invention.
4 is a scanning electron microscope image of a film-like carbonaceous material (comparative example) to which graphene is not added according to an embodiment of the present invention.
5 is a scanning electron microscope image of a film-like carbonaceous material having a continuous backbone in an embodiment of the present invention.
6 is a transmission electron microscope image of a film-like carbonaceous material having a continuous backbone in an embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In the present invention, the term "comprises" or "has" is intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

The present invention can manufacture a porous carbon material having a continuous skeleton through a carbonization and activation process after manufacturing a film-like carbonaceous material precursor having a continuous skeleton by using the phase separation phenomenon of the epoxy resin and the pore former to which graphene is added. there is.

The carbon material according to the conventional manufacturing method of the carbon material using an epoxy resin has a problem in that the electrical conductivity is lowered because the structure is not continuously connected, but the present invention can improve this problem. In addition, high efficiency can be achieved when applying a film-type energy storage device by manufacturing a new carbon material in which pores of several to several tens of μm are formed inside the continuous framework.

Hereinafter, the present invention will be described in detail.

In one embodiment, the present invention comprises the steps of forming a carbon precursor by mixing an epoxy resin and graphene; preparing a carbon material precursor having a continuous skeleton by adding a pore forming agent to the carbon precursor; coating a carbon material precursor having a continuous backbone on a substrate coated with polyvinyl alcohol (PVA) and then covering another polyvinyl alcohol coated substrate to prepare a film-type carbon material precursor; and carbonizing the film-like carbonaceous material precursor by heat treatment.

1 is a schematic diagram showing a manufacturing method of a film-like carbonaceous material having a continuous skeleton according to the present invention.

Referring to FIG. 1 , in the manufacturing method of the film-like carbonaceous material having a continuous skeleton, first, a carbon precursor is formed by mixing an epoxy resin and graphene. At this time, acetone may be added and mixed as a solvent, and the acetone may be removed by heating.

The content of the graphene relative to the total content of the epoxy resin may be 1 to 5 wt%. For example, the amount of graphene relative to the total amount of the epoxy resin may be 1 to 4 wt%, 1 to 3 wt%, 1 to 2 wt%, 2 to 5 wt%, or 2 to 3 wt%.

After forming the carbon precursor, a pore former is added to the carbon precursor. When the pore-forming agent is added, a curing agent for curing the epoxy resin may be added.

The pore forming agent may include a thermoplastic resin. Since the pore former is a material to be removed by dissolving in water, it may be a water-soluble thermoplastic resin that dissolves well in water. For example, the pore former may be polyethylene glycol (PEG).

2 is a schematic diagram showing a method for producing a film type in the method for producing a film type carbonaceous material having a continuous skeleton.

2, the carbon material precursor having a continuous skeleton prepared by mixing the carbon precursor and the pore forming agent is coated on a polyvinyl alcohol-coated substrate and then coated on another polyvinyl alcohol-coated substrate. After covering, it is thermally cured by heating.

The carbon precursor and the pore former are phase separated by using a phase separation phenomenon that occurs when two or more kinds of polymers are mixed due to physical properties of the polymer having a high molecular weight, and then heated to thermally cure only the epoxy resin of the carbon precursor. At this time, only the epoxy resin is thermally cured by the curing agent, graphene is dispersed in the cured epoxy resin, and the pore forming agent may exist in a phase-separated state without being cured.

The carbon material precursor having a continuous backbone may be coated on the polyvinyl alcohol-coated substrate to a thickness of 10 to 1,000 μm. For example, the coating thickness of the carbon material precursor having a continuous skeleton is 10 to 800 μm, 10 to 600 μm, 10 to 400 μm, 10 to 200 μm, 100 to 1,000 μm, 100 to 500 μm, 100 to 300 μm , 200 to 1,000 μm, 400 to 1,000 μm, 500 to 1,000 μm, or 800 to 1,000 μm may be coated to a desired thickness.

3 is a schematic diagram of a phase separation phenomenon for manufacturing a film-like carbonaceous material having a continuous skeleton according to the present invention.

As shown in FIG. 3, when the epoxy resin, graphene, and pore former are blended in a specific ratio and then heated at a designated temperature, a spinodal decomposion phenomenon occurs to form a carbon material precursor structure having a continuous skeleton.

The heating may be performed at 150 to 200° C. for 1 to 3 hours. For example, the heating may be heating at 160 to 180 °C or 170 °C.

The use of a substrate coated with polyvinyl alcohol on/under the carbon material precursor having a continuous skeleton during the thermal curing is because the epoxy resin adheres well to a general substrate such as glass when cured. This is to ensure that the film-like carbonaceous material precursor formed after curing by coating with polyvinyl alcohol can be well separated. For example, as shown in FIG. 3, spacers having a coating thickness of a carbon material precursor having a continuous backbone are placed on both sides of a substrate coated with polyvinyl alcohol, and the precursor is poured to cover the substrate coated with polyvinyl alcohol. After that, it may be cured.

After the curing, the film-like carbonaceous material precursor is separated from the polyvinyl alcohol-coated substrate, and then placed in ultrapure water and subjected to ultrasonic treatment to remove the pore-forming agent to prepare a film-like carbonaceous material precursor.

Since the pore-forming agent is not hardened during thermal curing and is a water-soluble material, it is possible to form voids in the place where the pore-forming agent was by dissolving it in ultrapure water.

As the mole fraction of the pore former relative to the epoxy resin increases, more of the pore former is removed when the pore former is removed, thereby increasing the size of the void.

Before carbonizing the film-like carbonaceous material precursor, a stabilization process may be performed at 300 to 350° C. for 10 to 50 minutes in an air atmosphere using a tubular electric furnace to increase thermal stability of the precursor. For example, the stabilization process may be performed at 310 to 330 °C or 320 °C for 20 to 40 minutes or 30 minutes.

After the stabilization process, the film-like carbonaceous material precursor having a continuous skeleton may be carbonized by heat treatment to prepare a film-like carbonaceous material having a continuous skeleton. In order to prevent the continuous skeleton from being collapsed by heat, the heat treatment may be to heat from the stabilization process temperature to 700 to 1,000 ° C at a heating rate of 0.5 to 10 ° C / min and then hold for 30 to 80 minutes. For example, the heat treatment is performed at a temperature elevation of 0.5 to 5 °C/min, 0.5 to 3 °C/min, 0.5 to 1 °C/min, 1 to 10 °C/min, 1 to 5 °C/min, or 1 to 2 °C/min. 700 to 900 ° C, 700 to 800 ° C, 700 to 750 ° C, 800 to 1,000 ° C, 800 to 900 ° C, 750 to 800 ° C or 700 ° C can be heated at a rate of 30 to 60 minutes, 30 to 60 minutes after heating It may be held for 50 minutes, 50 to 80 minutes, 50 to 70 minutes or 60 minutes.

The film-like carbonaceous material having a continuous skeleton may maintain a continuous skeleton and a porous structure by graphene even after undergoing a carbonization process at 700° C. or higher, and may include pores of several to several tens of μm in the continuous skeleton.

The carbonization may be performed in an inert gas atmosphere.

The carbonization step may be carried out by supporting upper and lower portions of the film-like carbonaceous material precursor with an alumina substrate in order to maintain the film-like structure during the heat treatment.

In addition, the present invention provides a film-like carbon material having a continuous skeleton, comprising a film having a continuous skeleton including an epoxy resin and graphene, wherein the film having a continuous skeleton has a thickness of 10 to 1,000 μm. do.

For example, the thickness of the continuous backbone film is 10 to 800 μm, 10 to 600 μm, 10 to 400 μm, 10 to 200 μm, 100 to 1,000 μm, 100 to 500 μm, 100 to 300 μm, 200 to 200 μm. 1,000 μm, 400 to 1,000 μm, 500 to 1,000 μm, or 800 to 1,000 μm.

The content of the graphene relative to the total content of the epoxy resin may be 1 to 5 wt%. For example, the amount of graphene relative to the total amount of the epoxy resin may be 1 to 4 wt%, 1 to 3 wt%, 1 to 2 wt%, 2 to 5 wt%, or 2 to 3 wt%.

The film-type carbon material having a continuous skeleton according to the present invention is a film-like carbon material having a continuous skeleton in which micrometer-level pores are introduced without the structure of the epoxy resin collapsing in the carbonization process at 700 ° C or higher by adding graphene to the epoxy resin. can be manufactured.

In addition, the film-like carbon material having a continuous skeleton can produce a film of a desired thickness, and it is possible to make a film of a porous carbon material, and electrical conductivity and charge mobility are increased by the addition of graphene and the continuous skeleton. can make it

Hereinafter, the present invention will be described in more detail through examples and the like according to the present invention, but the scope of the present invention is not limited by the examples presented below.

[Example]

Production Example: Production of a Film-Type Carbon Material Having a Continuous Skeleton

Epoxy Resin [Bisphenol A diglycidyl ether] 340.42 g/mol, Epoxy Resin Curing Agent [bis(4-aminocyclohexyl)methane] 210.37 g/mol, A pore former [polyethylene glycol] 200 g/mol and multilayer graphene powder (average thickness: 5 nm, average particle size: 11 μm) were used as raw materials. An epoxy resin and an epoxy resin curing agent are used to make a carbon precursor of a continuous skeleton through a thermal curing process, and a pore forming agent is used to prepare continuous pores through spinodal decomposition. Graphene is added to a mixture of an epoxy resin and an epoxy resin curing agent to contribute to the thermal stability of the continuous backbone and to increase electrical conductivity. A film-like carbonaceous material having a continuous backbone is manufactured by the following two-step manufacturing process.

1) Manufacture of film-type carbon material precursor

0 (no graphene, comparative example), 1, 3 wt% of graphene powder and 30 wt% of acetone were added to the epoxy resin, mixed using a blade mill, and then heated at 100 ° C to remove acetone. (Material A). 0.5 g of the curing agent and 3.5 g of the pore forming agent were added to 1 g of material A and mixed through ultrasonic treatment (material B). After coating the surface of the glass substrate with polyvinyl alcohol to a level of 1 μm, material B was coated thereon to a thickness of 200 μm. After covering with another polyvinyl alcohol coated glass, it was thermally cured by heating at 170° C. for 2 hours (Material C). After separating the polyvinyl alcohol-coated glass and the material C, they were placed in ultrapure water to remove the pore-forming agent inside the material C, and ultrasonic treatment was performed for 2 hours to remove the pore-forming agent to prepare a film-like carbonaceous material precursor. did

2) Carbonization process

Before carbonization, a stabilization process was performed at 320° C. for 30 minutes in an air atmosphere using a tubular electric furnace to increase the thermal stability of the precursor. Thereafter, heat treatment was performed at 700° C. for 1 hour in a nitrogen atmosphere. In order to prevent the continuous framework from being collapsed by heat, the heat treatment was performed as slowly as possible at a heating rate of 1° C./min. In addition, in order to maintain the film-like structure, a carbonization process was performed by supporting two alumina substrates above and below the precursor.

Experimental example

4 is a scanning electron microscope image of the prepared comparative example (a film-like carbon material without adding graphene).

Referring to FIG. 4 , it was confirmed that the continuous skeleton and porous structure collapsed by not adding graphene to the epoxy resin.

5 is a scanning electron microscope image of the film-like carbonaceous material having a continuous skeleton prepared above.

Referring to FIG. 5, it was confirmed that the carbon material synthesis and pore control were performed in which the structure was not collapsed by the addition of graphene to the epoxy resin.

6 is a transmission electron microscope image of the film-like carbonaceous material having a continuous framework prepared above.

As shown in FIG. 6, it was confirmed that graphene was introduced into the carbon skeleton.

Claims (9)

Forming a carbon precursor by mixing an epoxy resin and graphene;
preparing a carbon material precursor having a continuous skeleton by adding a pore forming agent to the carbon precursor;
coating a carbon material precursor having a continuous backbone on a substrate coated with polyvinyl alcohol (PVA) and then covering another polyvinyl alcohol coated substrate to prepare a film-type carbon material precursor; and,
A method for producing a film-like carbon material having a continuous skeleton, comprising the step of carbonizing the film-like carbon material precursor by heat treatment.
According to claim 1,
Method for producing a film-like carbon material having a continuous skeleton, characterized in that the content of the graphene relative to the total content of the epoxy resin is 1 to 5 wt%.
According to claim 1,
The method for producing a film-like carbonaceous material having a continuous skeleton, characterized in that the pore former comprises a thermoplastic resin.
According to claim 1,
In the step of preparing the film-like carbon material precursor,
A method for producing a film-like carbon material having a continuous skeleton, characterized in that the carbon material precursor having a continuous skeleton is coated on the polyvinyl alcohol-coated substrate to a thickness of 10 to 1,000 μm.
According to claim 1,
In the step of preparing the film-like carbonaceous material precursor, after coating the carbonaceous material precursor having the continuous skeleton on the polyvinyl alcohol-coated substrate, another polyvinyl alcohol-coated substrate is covered,
thermally curing the film-like carbonaceous material precursor by heating;
Separating the film-like carbonaceous material precursor from the polyvinyl alcohol-coated substrate; and,
A method for producing a film-like carbonaceous material having a continuous skeleton, further comprising the step of removing the pore-forming agent.
According to claim 1,
The heat treatment is a method for producing a film-like carbon material having a continuous skeleton, characterized in that heated to 700 to 1,000 ° C at a heating rate of 0.5 to 10 ° C / min and maintained for 30 to 80 minutes.
According to claim 1,
In the carbonization step,
In order to maintain the film-like structure during the heat treatment, the method of manufacturing a film-like carbon material having a continuous skeleton, characterized in that the upper and lower portions of the film-like carbon material precursor are supported by an alumina substrate.
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