JPS59146917A - Manufacture of porous carbonaceous material - Google Patents

Abstract

PURPOSE:To obtain inexpensively and easily a porous carbonaceous material by permeating a liquid composition consisting of an org. liquid substance and an inorg. substance into a resin having a tri-dimensional network structure and calcining after hardening. CONSTITUTION:A liquid composite consisting of an org. liquid substance and an inorg. substance is permeated into a resinous foam having a tri-dimensional network structure. The composite is hardened and calcined under an atmosphere of an inert gas. Resinous foams to be used are thermosetting resinous foams such as urethane foam, phenol foam having outside diameters in 0.1- several cm region and 5- max. 98% porosity. The above-mentioned org. liquid substance is an org. substance having >=5% carbonizing yield by calcination in an atmosphere of an inert gas. If the substance is not in a liquid state at ordinary temp., it is liquefied by using the initial condensing product of the substance and a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves baking a composite in which a resin foam having a three-dimensional network structure is impregnated with a liquid composition consisting of an organic liquid substance and an inorganic substance in an inert gas atmosphere. This is a method for producing a porous carbon material having a three-dimensional network structure, which faithfully reproduces the structure of the base resin foam, and has high strength and is extremely easy to manufacture. Concerning a method of manufacturing a body.

As used herein, the term carbon includes carbonaceous and graphitic substances.

Conventional methods for producing porous carbon materials include phenol,
There are methods to create resin foams such as urethane by firing, but these methods generally have a low carbonization yield of the resin, so the starting material foam undergoes extremely large volumetric shrinkage during firing, resulting in poor strength. There were drawbacks. As a method to improve these drawbacks, a method has been proposed in which a porous carbon material is produced by impregnating a resin foam such as urethane foam with a resin such as furan and firing it (Japanese Patent Publication No. 53-7536, etc.). In these methods, since the impregnated material is entirely composed of organic substances, the inventors' additional tests revealed that the strength of the carbon porous material after firing was too weak to withstand use, and the firing shrinkage rate was also low. However, the dimensional accuracy after firing was low.

An object of the present invention is to overcome the above-mentioned drawbacks, to produce a carbon porous body that is inexpensive, has continuous pores that have a three-dimensional network structure, has high strength, and uses a simple manufacturing method.

As a result of intensive research in order to achieve the above object, the inventors of the present application have developed a composite material in which a liquid composition consisting of an organic liquid substance and an inorganic substance is infiltrated into a resin foam having a three-dimensional network structure. We have succeeded in obtaining a porous carbon material having a three-dimensional network structure by firing in an inert gas atmosphere.

The method for producing a carbon porous body of the present invention will be specifically explained below.

Thermosetting resin foam such as resin foamed haurethane foam or phenol foam having a three-dimensional network structure used in the present invention, with an outer diameter in the range of 0.1 to several meters and a porosity of 5% to 98% maximum. It is.

A liquid composition consisting of an organic liquid substance and an inorganic substance is impregnated into this resin foam without any trenches. The organic liquid substance in this liquid composition is obtained by calcination in an inert gas atmosphere.
% or more and which does not exhibit a liquid state at room temperature is made into a liquid state using an initial condensate of the material or a solvent.

Examples of this organic substance include thermoplastic resins such as polyvinyl chloride, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride-vinyl acetate copolymers, phenolic resins,
Thermosetting resins such as furan resins, epoxy resins, and unsaturated polyesters; natural polymers such as lignin and cellulose; and synthetic polymers containing condensed polycyclic aromatics in the basic molecular structure such as formalin condensates of naphthalene sulfonic acid. molecular substances,
These include petroleum asphalt coal tar pinch, naphtha decomposition pinch, and carbonized products of hydrocarbon compounds such as synthetic resins at temperatures below 400°C.

The inorganic substances in the liquid composition include scaly graphite, green graphite, and carbon blank fine powder. This liquid composition refers to one or more of the above organic liquid substances containing 95 to 100%
5 to 9 parts by weight and one or more of the above inorganic substances
When mixed with 0 parts by weight using a mixer such as a Henschel mixer, it is obtained.

Next, excess liquid composition that has not permeated the surface of the resin foam is removed. In addition, if the inorganic substance has a large particle size as the inorganic substance in the liquid composition and the inorganic substance is difficult to penetrate into the resin foam, the resin foam surface ((take care not to remove the attached inorganic substance) .The composite is then cured.

This curing operation means, in the case of using a liquid composition using a thermosetting resin, to cause the resin to undergo a curing reaction, and in the case of a liquid composition using a solvent, to perform an operation of removing the solvent.

Next, the composite after the hardening operation is subjected to a carbon precursor treatment, and the resulting carbon precursor is heated to 800°C or higher, preferably 1000°C or higher in an inert gas atmosphere such as J element, argon, etc. and carbonize it.

There is no upper limit to the firing temperature, and if necessary
Even if it is heated up to about 500°C, there is no effect, and if the heating rate is up to 500°C, there is a drawback that the strength of the final product decreases by about 3 to 50°C.

Therefore, it is better to avoid a heating rate of more than 00°C/1] up to 500°C.For temperatures above 50.0°C, it depends on the heating method, but there is no particular restriction on the heating rate. .

The carbon porous material obtained according to the above method faithfully maintains the shape of the original resin foam, and its shrinkage rate ranges from 5 to 80 depending on the type and composition of the organic and inorganic substances in the liquid composition to be infiltrated. Become the person in charge.

This porous carbon material is composed of a resin foam, an organic substance, and an inorganic substance, so it has a lower carbon porous material than a carbon porous material made by infiltrating only an organic substance into a resin foam, or a carbon porous material made only from a resin foam. , stress diffusion becomes possible.

The carbon porous body obtained by this method is suitable for use in various filters, catalyst carriers, lightweight structural materials, planar heating elements, chemical adsorbents, radio wave shielding materials, and the like.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 Furan initial condensate (■ Hitafuran VF302 manufactured by Nippon Kasei Co., Ltd.
) 80 parts by weight, 10 parts by weight of graphite with an average particle size of 23μ, carbon blank (■ Denki Kagaku Denka polyurethane foam having a dimensional network structure was prepared, and the above liquid composition kl was prepared.
Allowed to penetrate for o minutes. The unpenetrated excess liquid composition that prevented the pores was then removed. This complex was heated to 100°C.
A curing reaction was performed in a dryer for 3 hours, and then a carbon precursor treatment was performed in a 180° C. dryer for 10 hours. This precursor treated product was fired in N2 gas at 20"C/h to 500°C, then fired at 100'C/h from 500°C to 100°C, kept at 1000°C for 2 hours, and then cooled in air at room temperature. A porous carbon material was obtained.The characteristics of the obtained porous carbon material are shown in Table 1.
Shown below.

Comparative Example 1 The same furan initial stage as in Example 1 and the condensate were infiltrated into a polyurethane foam of the same size for 10 minutes.

Thereafter, curing, precursor treatment, and firing were performed in the same manner to obtain a carbon porous body.

Table 1 shows the properties of the obtained porous carbon material.

Example 2 Chlorinated vinyl chloride resin powder with chlorine content of 67% and degree of polymerization of 740 (■ Nikatemp T-870 manufactured by Nippon Carbide) 7
0 parts by weight 15 parts by weight of graphite with an average particle diameter of 3 μm and 15 parts by weight of carbon blank (Denka Blank from Denki Kagakuten) were mixed in a Hen/L mixer, and tetrahydrofuran was added as a solvent to form a vertical, horizontal, and height liquid composition. . 4 cm x 4 cm x 4.
A polyurethane foam having a three-dimensional network structure (porosity: 80 cm) was prepared, and the above composition was permeated therein for 10 minutes.

The unpenetrated excess liquid composition that was blocking the pores was then removed. This complex f: 2 hours in a dryer at 100 °C ('i 2 hours at 20 °C, 2 hours at 140 °C, 160 °C
Carbon precursor treatment was carried out for 2 hours at 180°C and for 10 hours at 180°C. This precursor treated product was heated at 15°C in N2 gas for 50 minutes.
Firing to 0℃, 50℃ to 1000℃ from 500℃
After firing outside and holding at 1000° C. for 3 hours, the material was air-cooled to room temperature to obtain a carbon porous body.

Table 1 shows the properties of the obtained porous carbon material.

Comparative Example 2 The same chlorinated vinyl chloride resin powder as in Example 2 was dissolved in tetrahydrofuran and infiltrated into a polyurethane foam of the same size for 10 minutes. Thereafter, similar operations were performed to obtain a carbon porous body, which was treated with a precursor and fired. Table 1 shows the properties of the obtained porous carbon material.

Example 3 Chlorinated vinyl chloride resin powder with chlorine content of 65φ and degree of polymerization of 650 (■ Nikatemp T-025 manufactured by Nippon Carbide) 7
0 parts by weight, 10 parts by weight of graphite with an average particle size of 23 μm were crystallized in a Hen/El mixer, and then tetrahydrofuran was added as a solvent to make a liquid, in which a furan initial condensate (e. A foam was prepared and infiltrated with the above composition for 10 minutes.Then the uninfiltrated excess liquid composition preventing pores was removed.The composite was dried in a dryer at 100°C for 2 hours and at 130°C for 4 hours. time, 1
Carbon precursor treatment was performed at 60°C for 4 hours and at 180°C for 10 hours. Before this, the processed material was heated to 15°C in N2 gas.
/h up to 500°C, fired at 100°C from 500°C to 1000°C, held at 1000°C for 3 hours, and air cooled to room temperature to obtain a carbon porous body. Table 1 shows the properties of the obtained porous carbon material.

Comparative Example 3 70 parts by weight of the same chlorinated vinyl chloride resin powder as in Example 3 was dissolved in tetrahydrofuran, 20 parts by weight of the initial charge of furan was added and mixed, and a polyurethane foam of the same size was infiltrated for 10 minutes.

Thereafter, the precursor was treated and fired in the same manner to obtain a carbon porous body. Table 1 shows the details of the obtained porous carbon material.

Claims (5)

[Claims] (1) A three-dimensional network formed by impregnating a resin foam with a three-dimensional network structure with a liquid composition consisting of an organic liquid substance and an inorganic substance, curing the composite, and then firing it in an inert gas atmosphere. A method for producing a carbon porous body having a structure. (2) The resin foam having the three-dimensional network structure is made of a thermosetting resin such as foam, nord foam polyurethane foam, and has a pore size in the range of 0.1 to several σ and a porosity of 5.
1. The method for producing a porous carbon material according to item 1, wherein (3) The organic liquid substance is one or more organic substances that exhibit a carbonization yield of 95% or more when fired in an inert gas atmosphere. 1. The method for producing a porous carbon material according to item 1, which is made of an initial condensate of a substance or a substance dissolved in a solvent. (4) The method for producing a carbon porous body according to item 1, wherein the inorganic substance is one or a mixture of two or more of scaly graphite, earthy graphite, and chikara-den blank fine powder. (5) The method for producing a porous carbon material described in item 1, wherein the firing is carried out by heating to a temperature of 800° C. or higher.