JP7445944B1 - Method for manufacturing activated carbon compact - Google Patents

Abstract

An object of the present invention is to provide a method for producing an activated carbon molded body, which can obtain an activated carbon molded body by molding a thermoplastic resin into a predetermined shape and carbonizing the molded body. [Solution] This method for producing an activated carbon molded body 1 includes adding graphite, carbon black, carbon fiber, carbon nanotube, carbon nanofiber, graphene, etc. to a thermoplastic resin 2 such as PET, PP, PE, PS, PVC, or PMMA. A mixing step SA for adding and mixing powder of the carbon-based conductive material 3, a molding step SB for molding the thermoplastic resin 2 after the mixing step SA, and a carbonizing step SC for carbonizing the thermoplastic resin 2 after the molding step SB. and has. [Selection diagram] Figure 1

Description

The present invention relates to a method for producing an activated carbon molded body obtained by carbonizing a thermoplastic resin.

Activated carbon is a porous carbide, and in addition to the typical type, which is simply a collection of finely crushed carbon that absorbs odors and harmful substances, there are also activated carbon molded bodies that are formed into a predetermined shape. Are known. Activated carbon molded bodies are used, for example, in polarizable electrodes of electric double layer capacitors, as shown in Patent Document 1. Activated carbon can be obtained by carbonizing various materials, and can also be obtained by carbonizing thermosetting resins or thermoplastic resins (see Patent Document 1).

Activated carbon molded bodies are generally obtained by binding finely crushed activated carbon with a binder and molding it (see Patent Document 1), but as shown in Patent Document 2, thermosetting resin is It can also be obtained by molding it into a shape and carbonizing it. The latter manufacturing method has a simpler process and is more economical than the former manufacturing method.

JP2007-269518A Japanese Patent Application Publication No. 2002-234772

By the way, if thermosetting resins or thermoplastic resins can be used to reuse waste products such as products made from them or residues from product production, the process of producing carbonized materials can be omitted and costs can be reduced. It also contributes to waste reduction and resource recycling. Furthermore, the amount of products in the world and the corresponding amount of waste are much larger for thermoplastic resins than for thermosetting resins. However, when a thermoplastic resin is molded into a predetermined shape and heated to a high temperature for carbonization, it has difficulty retaining its shape due to its thermoplastic nature.

The present invention has been made in view of the above circumstances, and its purpose is to provide a method for producing an activated carbon molded body, which can obtain an activated carbon molded body by molding a thermoplastic resin into a predetermined shape and carbonizing it. Our goal is to provide the following.

In order to achieve the above object, the method for producing an activated carbon molded body according to claim 1 includes adding powder of a carbon-based conductive material (excluding activated carbon) to a thermoplastic resin at a weight ratio of 50% to 100% with respect to the thermoplastic resin. A mixing step in which the thermoplastic resin is added and mixed without using a binder, a molding step in which the thermoplastic resin after the mixing step is poured into a molding machine and molded, and a state taken out from the molding machine after the molding step. The method includes a carbonization step of heating and carbonizing the thermoplastic resin in an oxygen-free state, and an activation treatment step of subjecting the carbonized resin to an activation treatment .

The method for producing an activated carbon molded article according to claim 2 includes adding powder of a carbon-based conductive material (excluding activated carbon) to a thermoplastic resin at a weight ratio of 50% to 100%, and using a binder. The thermoplastic resin after the mixing step is poured into a molding machine and molded, and the thermoplastic resin is carbonized by heating in an oxygen-free condition while being held in the molding machine. and an activation treatment step of subjecting the carbonized material to activation treatment .

According to the method for producing an activated carbon molded body of the present invention, it is possible to obtain an activated carbon molded body by molding a thermoplastic resin into a predetermined shape and carbonizing it.

1 is a conceptual diagram showing a method for manufacturing an activated carbon molded body according to an embodiment of the present invention. It is a conceptual diagram which shows the modification of the manufacturing method same as the above.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated. The activated carbon molded body 1 that can be manufactured by the activated carbon molded body manufacturing method according to the embodiment of the present invention is molded into a predetermined shape. The activated carbon molded body 1 can be made into various shapes depending on the application, but for example, it can be used as a polarizable electrode of an electric double layer capacitor, an electrode of a redox flow battery or a desalination CDI device, or a building material (insulating material). material, electromagnetic wave absorbing material, soundproofing material, etc.) can be made into a plate shape.

As shown in FIG. 1, the method for producing an activated carbon molded body according to an embodiment of the present invention includes a mixing step SA, a forming step SB, and a carbonizing step SC.

The mixing step SA is a step in which powder of the carbon-based conductive material 3 is added to the thermoplastic resin 2 and mixed.

The thermoplastic resin 2 softens and becomes fluidized when heated from a hardened state at room temperature, and then becomes hardened again when cooled. For example, polyethylene terephthalate (PET), polypropylene, etc. (PP), polyethylene (PE), polystyrene (PS), vinyl chloride (PVC), methacrylic (PMMA), etc.

The carbon-based conductive material 3 exhibits conductivity by bonding carbon atoms together, and includes, for example, graphite, carbon black (acetylene black, furnace black, etc.), carbon fiber, carbon nanotube, carbon nanofiber, graphene, etc. included. Further, the powder of the carbon-based conductive material 3 includes powder, particulate, short fiber, and the like.

When adding and mixing the powder of the carbon-based conductive material 3 to the thermoplastic resin 2, carbon is added to the aggregate of the granules of the thermoplastic resin 2 (for example, pellets of crushed thermoplastic resin 2) at room temperature. Powder 3 of the conductive material can be added and mixed evenly.

The molding step SB is a step of molding the thermoplastic resin 2 after the mixing step SA.

Specifically, in the molding step SB, the heated and fluidized thermoplastic resin 2 is poured into a molding machine that corresponds to the predetermined shape of the activated carbon molded body 1 and molded. Thereafter, the thermoplastic resin 2 is taken out from the molding machine. The temperature of the thermoplastic resin 2 is lowered before and after taking it out.

The carbonization step SC is a step of carbonizing the molded body 1' of the thermoplastic resin 2 after the molding step SB.

The thermoplastic resin 2 is heated and carbonized in an oxygen-free state, and a large number of pores are generated in the thermoplastic resin 2.

On the other hand, in the carbon-based conductive material 3, the carbon atoms can be bonded to each other well enough to exhibit conductivity, so even if the thermoplastic resin 2 is heated to the carbonization temperature, the bonding state of the carbon atoms can be maintained. Can be done. Further, since the carbon-based conductive material 3 is made of the same carbon atoms as the carbonized thermoplastic resin 2, it has good affinity with the carbonized thermoplastic resin 2, and the specific gravity is almost unchanged when viewed near the contact portion.

In this way, the thermoplastic resin 2 mixed with the powder of the carbon-based conductive material 3 in the mixing step SA and molded in the molding step SB is carbonized while maintaining almost the predetermined shape at the time of molding, and becomes the activated carbon molded body 1.

After the carbonization step SC, the activated carbon molded body 1 can be subjected to a general activation treatment.

Next, a modification of the method for manufacturing an activated carbon molded body according to an embodiment of the present invention will be described. Here, the molding carbonization step SD is performed after the mixing step SA. The molding and carbonizing step SD is a step of molding and carbonizing the thermoplastic resin 2 after the mixing step SA.

Specifically, in the molding carbonization step SD, the heated and fluidized thermoplastic resin 2 is poured into a molding machine according to the predetermined shape of the activated carbon molded body 1, and the thermoplastic resin 2 is molded into the molding machine. It is carbonized in the same manner as in the carbonization step SC above. In this way, the powder of the carbon-based conductive material 3 is mixed in the mixing step SA, and is molded and carbonized in the compacting and carbonizing step SD to form the activated carbon compact 1.

After the carbonization step SD, the activated carbon compact 1 can be subjected to a general activation treatment.

Next, an experiment conducted by the inventor of the present application will be explained. The thermoplastic resin 2 was polyethylene terephthalate (PET), and the carbon-based conductive material 3 was graphite. A spaghetti-like material (strand) was produced using an extruder as a molding machine, and the strand was carbonized and used as a sample. In Table 1 below, sample A is one in which powder of carbon-based conductive material 3 is added to thermoplastic resin 2 at a weight ratio of 100% (that is, the same weight), and sample B is one in which powder of carbon-based conductive material 3 is added to thermoplastic resin 2 at a weight ratio of 100% (that is, the same weight). Sample C has carbon-based conductive material 3 powder added to thermoplastic resin 2 at a weight ratio of 50%, Sample D has carbon-based conductive material 3 added to thermoplastic resin 2 at a weight ratio of 10%. It's something I didn't do.

As shown in Table 1, the shapes of the activated carbon molded bodies 1 could not be maintained in samples C and D, but the shapes of the activated carbon molded bodies 1 could be maintained in samples A and B.

In this way, by adding an appropriate amount of powder of the carbon-based conductive material 3 to the thermoplastic resin 2, it is possible to obtain the activated carbon molded body 1 by molding the thermoplastic resin 2 into a predetermined shape and carbonizing it. become. Further, if waste is used for the thermoplastic resin 2, it is possible to reduce costs, and also contributes to waste reduction and resource recycling.

Moreover, since the activated carbon molded body 1 contains the carbon-based conductive material 3 without using the binder, it can easily be made to have excellent conductivity. The activated carbon molded body 1 can be used as it is as a polarizable electrode of an electric double layer capacitor by utilizing its excellent conductivity. In addition, the activated carbon molded body 1 can be used as it is for electrodes of redox flow batteries, desalination CDI devices, etc., taking advantage of its excellent conductivity.

Moreover, the activated carbon molded body 1 can be used for building members (insulating materials, electromagnetic wave absorbing materials, soundproofing materials, etc.) or other members even when electrical conductivity is not required. Including the carbon-based conductive material 3 generally increases thermal conductivity, so its properties can also be utilized in building materials or other materials.

Although the method for manufacturing an activated carbon molded body according to the embodiment of the present invention has been described above, the present invention is not limited to what is described in the embodiment, and can be applied to various methods within the scope of the claims. Design changes are possible. For example, it is also possible to incorporate reinforcing materials such as reinforcing fibers into the molding process during the molding step SB or the molding and carbonization step SD.

1 Activated carbon molded body 1' Thermoplastic resin molded body 2 Thermoplastic resin 3 Carbon-based conductive material SA Mixing process SB Molding process SC Carbonization process SD Molding carbonization process

Claims (2)

A mixing step of adding powder of a carbon-based conductive material (excluding activated carbon) to a thermoplastic resin at a weight ratio of 50% to 100% to the thermoplastic resin and mixing without using a binder;
a molding step of pouring the thermoplastic resin after the mixing step into a molding machine;
a carbonization step of heating and carbonizing the thermoplastic resin taken out from the molding machine after the molding step in an oxygen-free state;
an activation treatment step of subjecting the carbonized material to activation treatment;
A method for producing an activated carbon molded body having the following. A mixing step of adding powder of a carbon-based conductive material (excluding activated carbon) to a thermoplastic resin at a weight ratio of 50% to 100% to the thermoplastic resin and mixing without using a binder;
A molding carbonization step in which the thermoplastic resin after the mixing step is poured into a molding machine and molded, and the thermoplastic resin is heated and carbonized in an oxygen-free state while being held in the molding machine;
an activation treatment step of subjecting the carbonized material to activation treatment;
A method for producing an activated carbon molded body having the following.

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