JPS58151316A - Manufacture of molded carbon body - Google Patents

Abstract

PURPOSE:To form a homogeneous molded carbon body with superior strength and hardness, by molding a specified powdered phenol-aldehyde resin contg. nitrogen or a composition contg. the resin and by carbonizing and calcining the molded body. CONSTITUTION:A powdered resin obtd. by reacting phenols with a compound contg. nitrogen in a hydrochloric acid-formaldehyde bath is used. The bath has about 3-28wt% concn. of hydrochloric acid, about 3-25wt% concn. of formaldehyde, about 10-40wt% total concn. of hydrochloric acid and formaldehyde, and about 10-40wt% concn. of aldehydes other than formaldehyde. The powdered resin contains spherical particles (primary particles and secondary aggregates thereof) having 0.1-100mum particle size and has an infrared absorption spectrum (KBr disk method) satisfying relation expressed by the equation (where Dx-y is the maximum absorption intensity at x-ycm<-1> wavelengths). The powdered resin or a composition prepared by mixing the resin with a thermosetting resin is molded under heating, and the molded body as a precursor is carbonized and calcined.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a carbon molded body. More specifically, it is a novel granular or powdery compound that has good flow characteristics and reactivity, and exhibits excellent moldability and carbonization yield by itself or when mixed with various carbonized materials, fillers, etc. This invention relates to a method for producing a carbon molded article with excellent strength and high hardness using nitrogen phenol aldehyde resin.

Conventionally, novolac resins and resol resins are known as typical phenol-aldehyde resins. Novolak resins are usually prepared under conditions of excess phenol, such as a molar ratio of phenol to formaldehyde of, for example, 1:0.7 to 0.9, and in the presence of an acid catalyst such as oxalic acid (usually 0.2 to 0.9). 2π) by reacting phenol with formalin. The novolac resin obtained by such a method is mainly composed of trimers to pentamers of phenols bonded mainly through methylene groups, contains almost no free methylol groups, and therefore does not have self-crosslinking properties by itself. It has thermoplastic properties.

The novolac resin is then reacted under heat with a crosslinking agent which is itself a formaldehyde generator and also an organic base (catalyst) generator, such as hexamethylenetetramine (hexamine), or with a solid acid catalyst and paraformaldehyde, etc. It can be made into a cured resin by mixing with the resin and causing a heating reaction.

Novolac resins are powdered and easy to handle, but when a molded product is heated and cured, curing progresses from the surface of the molded product to the inside, often resulting in a cured product whose interior is not sufficiently cured. Therefore, when such a hardened product is subjected to carbonization firing, gas is generated inside the molded product, causing cracks and gas blisters in the molded product.As the carbonization firing progresses, these cracks and gas blisters become more noticeable, resulting in unsatisfactory quality. It is very difficult to produce a carbon molded body.

Additionally, resol resins are usually supplied as solutions, and therefore,
It is very difficult to make a molded product by itself by removing the solvent because the gelation reaction proceeds while foaming occurs during the removal of the solvent.

For this reason, it is common practice to use a filler material to desolvent and mold the product, but when such a molded product is subjected to carbonization firing, gas blisters and cracks occur, similar to the case with the novolac resin mentioned above, and the strength is reduced. Alternatively, it is extremely difficult to produce a carbon molded body with satisfactory quality in terms of hardness.

In addition, in relatively recent years, novolac resins have been heated at high temperatures to obtain products with a fairly high degree of condensation, and this has been purified to separate and remove low condensates, resulting in 7 to 10 phenol groups and methylene groups. A relatively high condensate bonded with A method of producing cured novolac resin fibers was proposed by proceeding the curing reaction from the outside of the fibers (%Ko-Sho No. 48-11284).
.

However, cutting or crushing the cured novolak fibers produced as described above is not only expensive, but also cannot be used as a molding material in the form of granules or powders with good flow characteristics.

A method for producing a carbon molded body from a composition of the above-mentioned cured novolac resin fibers and other carbonized materials has also been proposed very recently (1986-77293).
(see issue). However, as mentioned above, cured novolac resin fibers are not granular or powdered resins with good flow characteristics and are not reactive, so they always require other carbonized materials as binders. For example, during injection molding, nozzles may become clogged, or it may be difficult to produce a molded article in which the fibers are uniformly dispersed.

In addition, in recent years, a hydrophilic polymer compound is added to a condensate obtained by reacting phenols and formaldehyde in the presence of at least a nitrogen-containing compound, and the reaction is performed to produce granular or powdered resin. A method has been published. (Japanese Patent Publication No. 53-42077), the non-gelled resin obtained by this method contains a large amount of free phenol, about 5 to 6%.
Example 5) is not only an extremely hard non-reactive resin but also contains a hydrophilic polymer compound. Therefore, it not only deteriorates the performance of the molded product itself obtained by using it as a filler, but also has the drawback of causing cracks and gas blisters in the carbon molded product obtained from the molded product.

Furthermore, a method is known in which a prepolymer obtained by reacting phenol and formaldehyde in a basic aqueous solution is mixed with a colloid and coagulated into inert solid beads under acidic conditions (Japanese Patent Publication No. 51-13491). ), this corresponds to the so-called cured resol resin, and has no reactivity, and also contains salts, acids, and other protective colloids, so the performance of the molded product itself obtained by using it as a filler is affected. This has the disadvantage that not only does it cause a decrease in carbon properties, but also cracks and gas blisters occur in the carbon molded product obtained from the molded product.

As mentioned above, attempts have been made to use phenol formaldehyde resin as a filler in molded products, but
When viewed as a filler for molded products, it is difficult to obtain phenol-formaldehyde resin in a shape or form suitable for use as a filler, and it is also undesirable for molded products, especially molded products for carbonization. It has the problem of containing substances that have an impact.

The present inventors have previously provided a new granular or powdery nitrogen-containing phenol aldehyde resin that does not have the above-mentioned drawbacks, and a method for producing the same.

Therefore, an object of the present invention is to provide a method for producing a carbon molded body using a novel granular or powdery nitrogen-containing resin as a carbonized material.

Another object of the present invention is to produce a carbon molded body having excellent strength and high hardness by using a granular or powdery nitrogen-containing resin having excellent flow characteristics as a carbonized material. The purpose is to provide a method.

Still another object of the present invention is to produce a carbon molded body with a high carbonization yield from a precursor molded body (a molded body for carbonization) using the granular or powdered nitrogen-containing resin as a carbonization material. The goal is to provide a way to do so.

Still another object of the present invention is to use a granular or powdery nitrogen-containing resin that is reactive with itself or with other resins as a carbonization material, thereby reducing cracks and gas blisters, and making it possible to bond between the inside and the outside. It is an object of the present invention to provide a method for producing a precursor molded body with almost no unevenness in quality, and thus producing a carbon molded body having no cracks or gas blisters and having a homogeneous inside and outside from the precursor molded body.

Still another object of the present invention is to provide a method for producing a sponge-like carbon molded body having excellent strength and high hardness.

Still another object of the present invention is to provide a method for producing a carbon molded body having excellent strength, high hardness, and an extremely large specific surface area.

Still another object of the present invention is to provide a method for manufacturing a carbon molded body that has excellent strength and high hardness and exhibits electrical conductivity ranging from a conductor to a non-conductor.

Still another object of the present invention is to provide a method for producing a carbon molded article that has excellent strength and high hardness, and also exhibits excellent heat resistance, wear resistance, sliding properties, and chemical resistance. be.

Still another object of the present invention is to provide a nitrogen-containing carbon molded article having a high specific surface area.

Further objects and advantages of the present invention will become apparent from the following description.

These objects and advantages of the present invention are, according to the present invention, a granular or powdered resin comprising a phenol, a nitrogen-containing compound having at least two active hydrogens, and a condensate with an aldehyde, comprising: (A ) The granular or powdered resin has a particle size of 0.1-10
Contains 0 micron spherical particles and secondary aggregates thereof, and has the largest absorption intensity in the range of 11450 to 1500 m'' in the infrared absorption spectrum of (B) # resin by KBr tablet method. 7. And 960-1020 cm-'
The largest absorption intensity in the range of DI60 to I11! <1
When expressed in %: I) *ao--sow. / DI4110~1! to
A thermoformable resin composition containing at least a granular or powdery nitrogen-containing phenol aldehyde (+=o, 1 to 2.0), or a thermoformable resin composition containing at least a granular or powdery nitrogen-containing phenol aldehyde resin. This is achieved by a method for producing a carbon molded body, which is characterized in that a precursor molded body is thermoformed from a thermoformable material alone, and then the precursor molded body is carbonized and fired.

Such granular or powdered nitrogen-containing phenolic aldehyde resin used in the present invention is composed of phenol, or phenol containing at least 50% by weight of phenol, especially at least 70% by weight of phenol and '#LId O-cresol;
m-cresol, p-cresol, bis-phenol A
10-lm- or p C*~C4 alkylphenol,
It includes a condensation product of a mixture with one or more known phenol derivatives such as p-phenylphenol, xylenol, and resorcinol, and a atomic compound having at least two active hydrogens and an aldehyde.

The granular or powdery nitrogen-containing resin in the resin composition of the present invention has the properties (A) and (B) described above.

In specifying (A) and CB) above, the particle size of the spherical-order particles and their secondary aggregates of (A) is 0.
．． Specifying that it is 1 to 100 microns, (B) D...07% - 10 6/D1410 to 1100 = 0.
The identification of 122.0 is based on the measurement method described below.

The first characteristic of the granular or powdered nitrogen-containing resin is that it is extremely difficult to crush a conventionally known cured product of novolak resin or cured resol resin, but it can be Completely different from known pulverized cured novolac resin fibers, most of them are spherical-order particles and secondary aggregates thereof, with a particle size of 0.1 as specified in (A) above. ~100 microns, preferably 0.1 to 50 microns.

Generally, at least 30%, preferably at least 50% of the granular or powdered nitrogen-containing resin has a particle size of 0.1 to 10%.
It consists of spherical-order particles of 0 micron, more preferably 0.1 to 50 micron, and secondary aggregates thereof. These 30
% or 50% refers to 30% or 50% of the total number of particles (including secondary aggregates) in one field of view of an optical microscope with a magnification of 100 to 1000 times, as defined in the particle size measurement method described below. It means 50%. Particularly preferred is one in which 70 to substantially 100% of the granular or powdered nitrogen-containing resin consists of spherical primary particles and secondary aggregates thereof having a particle size of 0.1 to 100 microns.

Particularly preferred is at least 30%, especially at least 50% of the number of particles in the field of the optical micrograph according to the above definition (as the average value of 5 fields), and from 70 to substantially 1.
00% is 0.1-50 microns, more preferably 0.1
It consists of spherical-order particles and their secondary agglomerates in the range of ~20 microns.

As mentioned above, the granular or powdery nitrogen-containing resin is
Since it is mainly formed of the fine particles of the above-mentioned spherical-order particles and their secondary aggregates, it is extremely small, and is at least 50% by weight, preferably 70% by weight, particularly preferably 70% by weight of the total. At least 80% by weight of the total is 150%
Pass through Tyler Metshiyu's simple. Such an indication that the granular or powdered product passes through a sieve is used in the operation of sieving the granular or powdered product using the armpit, such as by gently kneading the granular or powdered product with your hands or using a brush-like method. Do not apply any force that does not forcefully destroy the particles (secondary aggregates), such as lightly pushing or smoothing the particles on the sieve, or tapping them with your hand. It is not something to be excluded.

The above granular or powdery nitrogen-containing resin may further include the above (B
), in the infrared absorption spectrum, Dose~wets/D+aso~ts@e=0
−1 to 2,0 Preferably, further D1tao to tsao/D t4so to tsoe=
It has a characteristic of 0.15 to 3.0.

Further, preferable granular or powdery nitrogen-containing resins used in the present invention are D@@6-1616 / DH466-1 O@8
0.1 5-0.6 Preferably, further D It80-%-1sso/' D14!1(1-%
-1100"0.2 to 2-0, and particularly preferred are D@@6 to 1616/D 145
0~I6=0.2~O64 Preferably, further Dstao--tmso/DI4110~ll06
= 0.3 to 1.5.

Further, the granular or powdery nitrogen-containing resin used in the present invention further has an infrared absorption spectrum of 1
When the maximum absorption intensity in the range of 580 to 1650 cm-'' is expressed as 11) +5se
--1sso/Dstao-tso6=0.3~4
．． 5 (preferably 0.75 to 2.01, particularly preferably 1
．． 0 to 1.5) in the infrared absorption spectrum.

Generally, it is difficult to determine the genus of various functional groups of a substance having a three-dimensional crosslinked structure using an infrared absorption spectrum. That is, this is because the peak in an infrared absorption spectrum diagram often shifts significantly.

However, from the infrared absorption spectra of phenol aldehyde resins and various nitrogen-containing compounds, the above absorption in the infrared absorption spectrum in the present invention shows that the absorption at 960 to 1020ffi' is a peak belonging to the methylol group, and the absorption at 1280 to 1360 evs-' is a peak belonging to the methylol group. The absorption is a peak attributed to carbon-nitrogen bonds, and 14
The absorption between 50 and 15003-' was determined to be a peak attributed to aromatic double bonds.

In addition, although it is difficult to clearly attribute the absorption of 1580 to 16503-1, the above ratio I) + s using the intensity of this absorption
The value of ao ~ 16110/D1410 ~ 11100 indicates a value that can clearly distinguish the ratio in phenol formaldehyde resins that do not contain nitrogen, so it can be used as a characteristic absorption similarly to the rounding that specifies the resin of the present invention. Recognizable.

The ratio of the above absorption intensities in the infrared absorption spectrum, which is one parameter for specifying the granular or powdery nitrogen-containing resin used in the present invention, for example, 6
゜~1゜. /DI4m. ~1. . . ~0.1~2.0
This range is related to the structure that the nitrogen-containing resin used in the present invention contains a considerable amount of methylol groups, and the content of methylol groups can also be adjusted within a certain range. It can be understood that it represents the characteristic value.

The granular or powdered nitrogen-containing resin used in the present invention usually has a free phenol content of 500 ppm or less as measured by liquid chromatography, and more preferred products have a free phenol content of 300 ppm or less,
In particular, it is 1100 pp or less. Said special public service 1973-420
The granular or powdered resin obtained by the method disclosed in No. 77 contains an extremely large amount of free phenol ranging from 0.3 to about 611% by weight, whereas the granular or powdered nitrogen-containing resin used in the present invention The free phenol content of the resin is extremely low. This fact provides an important advantage in use for this type of granular or powdered resin.

It has also been found that many of the granular or powdered nitrogen-containing resins used in the present invention contain at least 1% by weight of nitrogen, preferably 2 to 30% by weight.

The granular or powdered nitrogen-containing resin used in the present invention can be in either a state in which the curing reaction has not progressed sufficiently, or in a state in which the curing reaction has progressed relatively, according to the manufacturing method described later. As a result, it was found that the granular or powdered nitrogen-containing resin used in the present invention thermally exhibits at least (a) This includes both those that partially fuse to form a lump or plate-like body, and those that do not substantially melt or fuse and take the form of granules or powder.

When the solubility of the resin in (a), which has relatively high fusibility, is measured in methanol according to the test method described later, it has a methanol content of 20% by weight or more, further 30% by weight or more, and even 40% by weight or more. Includes resins that exhibit solubility.

The granular or powdered resin used in the present invention is characterized by having the properties (Al and (B)) described above.

The granular or powdered nitrogen-containing resin used in the present invention has a particle size of 0.1 to 100 microns, preferably 0.1 to 100 microns.
Containing 50 micron spherical-order particles and their secondary aggregates (condition (A) above) preferably contain at least 50% of these, and usually at least 50% by weight, preferably at least 70% by weight. Since it has a size that allows its weight percent to pass through a 150-meter mesh sieve, it has extremely good fluidity and can be easily mixed with other carbonized materials in a relatively large amount. Further, since at least many of the granular or powdery nitrogen-containing resins used in the present invention have extremely small spherical primary particles as a basic constituent, the thermosetting resin of the present invention containing these particles The cured moldings obtained by curing the composition exhibit excellent mechanical properties, in particular strong resistance to compression. The granular or powdered nitrogen-containing resin used in the present invention is extremely stable at room temperature, but since it itself contains a considerable amount of methylol groups, it shows reactivity when heated, and as shown in the examples below, it exhibits reactivity. A cured molded pipe is formed that has extremely excellent not only mechanical properties but also heat insulation, heat resistance, low electrical insulation properties, and chemical properties.

The granular or powdered nitrogen-containing resin used in the present invention further has a low free phenol content of usually 500 ppm or less, preferably 300 ppm or less, especially 1100 ppm or less. Since the phenol content is extremely low, the granular or powdered nitrogen-containing resin used in the present invention is extremely easy to handle and safe. Further, since the granular or powdered nitrogen-containing resin used in the present invention has an extremely low free phenol content as described above, side reactions caused by phenols are reduced when a precursor molded body is obtained from it.

Further, the granular or powdery nitrogen-containing resin used in the present invention is manufactured by a manufacturing method that does not substantially contain a hydrophilic polymer compound in the reaction system, as is clear from the manufacturing method described below. Therefore, it usually does not substantially contain hydrophilic polymer compounds.

As mentioned above, the granular or powdered nitrogen-containing phenol/aldehyde copolymer resin used in the present invention is extremely fine, has good storage stability and flow characteristics, and contains a certain amount of methylol groups, so it can be used for preforming. It has the excellent feature of providing a carbon molded body with uniform physical properties because it is reactive when molded and heated.

The granular or powdered resin used in the present invention includes (1) the following composition (a), hydrochloric acid (HCII concentration: 3 to 28% by weight), formaldehyde (HCHOIII[2>!3 to 25% by weight, and formaldehyde). The concentration of aldehydes other than
~10% by weight, and c) the total concentration of hydrochloric acid and formaldehyde is 10~40%
C) A phenol and a nitrogen-containing compound having at least two active hydrogens are added to a hydrochloric acid-formaldehyde bath having the following formula (I) in weight percent, It can be produced by contacting them while maintaining the ratio to be at least 8 or more.

The composition of the hydrochloric acid-formaldehyde bath in 0) above is as follows:
In addition to the above three conditions (a), (b), and (c), there is an additional condition (2).
It is preferable that the total is at least 2 or more, especially 2.5 or more, especially 3 or more. The upper limit of the molar ratio in the above condition 2) is not particularly limited, but it is preferably 20 or less. The upper limit of the molar ratio in the above condition 2) is not particularly limited, but is preferably 20 or less, particularly 15 or less. The above molar ratio is preferably 4 to 15, particularly preferably 8 to 10. The characteristics of the above production method are that a bath of a hydrochloric acid-formaldehyde aqueous solution having a fairly high concentration of hydrochloric acid (HCl) and containing formaldehyde in excess of phenols and nitrogen-containing compounds is used at a bath ratio of 8. As mentioned above, contact with phenols and nitrogen-containing compounds is preferably carried out at a large ratio of 10 or more.

That is, to explain further, the above method is carried out under the conditions that the respective concentrations of hydrochloric acid and formaldehyde are 3% by weight or more and the bath ratio is 8 or more, so that the total weight of phenols and nitrogen-containing compounds is The weight ratio of both hydrochloric acid and formaldehyde to
% by weight.

Furthermore, since the above method is carried out at a total concentration of hydrochloric acid and formaldehyde of 10% by weight or more, the total weight of hydrochloric acid and formaldehyde relative to the total weight of phenols and nitrogen-containing compounds is 80% by weight or more. Such reaction conditions are fundamentally different from those previously described for the production of novolak and resol resins.

When bringing the phenol and the nitrogen-containing compound into contact with a hydrochloric acid-formaldehyde bath, the bath ratio represented by the formula (I) is preferably 10 or more, particularly 15 to 40. The contact with the 9 element-containing compound is carried out in such a way that after the phenol comes into contact with the iron bath, white turbidity is formed, and then a granular or powdery solid is formed. The contact between the hydrochloric acid-formaldehyde bath and the phenol and the nitrogen-containing compound can be carried out by adding the phenol and the nitrogen-containing compound together into the hydrochloric acid-formaldehyde bath, or by adding the nitrogen-containing compound and then adding the phenol. It is preferred to first form a clear solution, then to form a cloudy cloud, and then to form a granular or powdery solid.

At this time, before or at the stage where phenols are added to the iron bath to produce white turbidity, the iron bath is stirred so that the added phenols and nitrogen-containing compounds form a transparent solution as uniform as possible in the iron bath. Depending on the ratio of phenols and nitrogen-containing compounds and the reaction conditions, mechanical shearing force such as stirring may be applied to the iron bath (reaction liquid) during the period from the time when cloudiness occurs until solid matter is formed. It is preferable not to have any.

The phenol to be added may be the phenol itself, or may be a diluted phenol with formalin, an aqueous hydrochloric acid solution, water, or the like.

Furthermore, when adding phenols or phenols and nitrogen-containing compounds (or diluted solutions thereof), the temperature of the hydrochloric acid-formaldehyde bath or the temperature of the hydrochloric acid-formaldehyde bath in which the nitrogen-containing compound has been dissolved in advance is 90°C. below,
In particular, a temperature of 70° C. or lower is preferred. The temperature of the iron bath is 40
℃ or higher, especially 50℃ or higher, the reaction rate between phenols and nitrogen-containing compounds and formaldehyde increases, so phenols or phenols and nitrogen-containing compounds should be diluted with the formalin solution. It is preferred to add it to the iron bath as a diluted solution.

In this case, since the reaction rate is high, the phenols, or the phenols and the nitrogen-containing compound, are added to the iron bath, especially in the form of a trickle of a diluted solution thereof, or as fine droplets as possible, and brought into contact. It is preferable to force it.

When the bath temperature is higher than 40°C, especially higher than 50°C,
When phenols, phenols and nitrogen-containing compounds, or diluted solutions thereof are brought into contact with this bath, the higher the bath temperature, the faster the reaction rate between phenols and nitrogen-containing compounds. After that, white turbidity occurs within a short time or instantaneously within several minutes, and a solid substance in the form of granular glass powder is rapidly formed.

The temperature of the hydrochloric acid-formaldehyde bath is maintained at 40°C or less, preferably 5° to 35°C, particularly preferably 10 to 30°C, and phenols and nitrogen-containing compounds are added to this bath as they are or their diluted solutions, preferably phenol. A granular or powdery solid material is obtained by adding a diluted water solution of a nitrogen-containing compound and completing the desired reaction at a temperature of approximately 50°C or lower, preferably 45°C or lower after white turbidity is formed. Since it has not progressed that far, it is generally heated to 100℃ as described below.
It shows heat fusion properties in a heat fusion test.

On the other hand, the temperature of the hydrochloric acid-formaldehyde bath is maintained at 40° C. or lower, preferably 15° to 35° C., and the phenols and nitrogen-containing compounds to be added to this bath are stirred as they are or substantially the entire amount of the diluted solution thereof. A clear solution is formed by adding the mixture to the bottom, and then a white cloud is formed under non-stirring conditions, and then a light pink granular or powdery solid is formed with or without increasing the temperature, and this solid is If the desired reaction is completed by heating to a temperature higher than 50°C, preferably from 70' to 95°C, the curing reaction will be carried out well, so the heat fusion property at 100°C will decrease or or exhibit heat-fusibility at higher temperatures, such as 200° C., or have substantially no heat-fusibility even at such high temperatures.

In any of the above cases, the nitrogen-containing compound may be added in advance to the hydrochloric acid-formaldehyde bath, and then only the phenol may be added.

The phenol used in the above method is most preferably phenol, but at least 50% by weight, especially at least 7% by weight.
If it contains 0% by weight of phenol, 0-cresol, m-cresol, p-cresol, bis-phenol A, O+, m- or tfp C*~C4 alkylphenol, p-phenylphenol, xylenol, resorcinol, etc. It may be a mixture with one or more known phenol derivatives.

The nitrogen-containing compound used in the above method is a compound having at least two active hydrogens in its molecule, preferably an amino group, an amide group, a thioamide group, a urein group, or a thiouraine group having active hydrogens in its molecule. A compound having at least one group selected from the group consisting of:

Examples of such nitrogen-containing compounds include urea, thiourea, methylol derivatives of urea or thiourea, aniline, melamine, guanidine, daanamine, dicyandiamide, fatty acid amide, tetraamide, toluidine, cyanuric acid, or functional derivatives thereof. It will be done. These F
i can be used alone or in combination of two or more.

The granular or powdered solid nitrogen-containing phenol aldehyde resin produced in the bath as described above and having completed the desired reaction is separated from the hydrochloric acid-formaldehyde bath, washed with water, and preferably The desired product can be obtained by neutralizing the hydrochloric acid with an alkaline aqueous solution, such as aqueous ammonia or methanolic aqueous ammonia, and further washing with water. In this case, as a matter of course, if the resin has a relatively high solubility in methanol, it is preferable to neutralize it with an aqueous alkaline solution.

The method of the present invention is carried out by first producing a precursor molded body by thermoforming from the above-mentioned granular or powdered nitrogen-containing phenol/aldehyde resin alone or from a resin composition containing at least the granular or powdered nitrogen-containing resin. .

The granular or powdered nitrogen-containing phenolic aldehyde resin or the resin composition used alone must be highly thermoformable.

Therefore, at least a portion of the granular or powdered nitrogen-containing phenol aldehyde resin used alone is one that fuses when held at a temperature of 100°C for 5 minutes according to the thermal fusion measurement method. The above nitrogen-containing phenol/aldehyde resin (al) or the nitrogen-containing phenol/aldehyde resin (a) which does not substantially melt or fuse with the nitrogen-containing phenol/aldehyde resin (a) according to the heat fusion measurement method Mixtures with phenolic aldehyde resins are preferably used. In the case of the latter (mixture), the nitrogen-containing phenol/formal and dehyde tung fat (c) act as fillers, and the nitrogen-containing phenol/aldehyde resin (al) acts as a binder in the precursor molded body.

In the case of the above-mentioned resin composition containing a granular or powdered nitrogen-containing phenol-aldehyde resin, the nitrogen-containing phenol-aldehyde resin does not necessarily have a property that at least a part of it is fused according to the thermal fusion measurement method. thing (a
) or a mixture of (a) and (b)! ! There isn't. That is, as long as the resin composition contains a thermoformable binder in addition to the granular or powdered nitrogen-containing phenol-aldehyde resin, the granular or powdered nitrogen-containing phenol-aldehyde resin does not need to be fusible (a). In other words, the granular or powdered nitrogen-containing phenol/aldehyde resin is
If other resins that can act as binders are present, they can be used in exactly the same way, whether they are fusible (Al or non-fusible or non-fusible (b)).

As is clear from the foregoing, what is important in the present invention is the above-mentioned granular or powdered nitrogen-containing phenol.
The use of the aldehyde resin as a component of the precursor molding does not mean whether the resin is a filler or an ingredient for the precursor molding. Whether it is fusion-adhesive (because it is not) must be taken into consideration when manufacturing the precursor molded body, but whether granular or powdered nitrogen-containing phenol in 6) or (bl)
Even if an aldehyde resin is used, a carbon molded body having excellent strength and hardness can be obtained by carbonization and firing.

In the method of the present invention, the precursor molded body is made of a granular or powdery 9-containing phenol aldehyde resin alone, and the granular or powdery nitrogen-containing resin has fusibility (
In the case of a mixture of a) and those having no fusibility, the al of the above-mentioned fusibility
% by weight, more preferably 20% by weight, especially 30% by weight.

In the method of the present invention, the resin composition containing at least a granular or powdered nitrogen-containing phenol aldehyde resin is
In addition to the granular or powdery nitrogen-containing phenol aldehyde resin, other carbonized materials may be contained.

The carbonized material may be a curable resin (first carbonized material). Thermosetting resin is preferred as the first carbonized material. For example, resol resin, novolak resin,
Polymer resin, furan resin, melamine resin, carbon resin, etc. are preferably used. These carbonized materials can act as binders, so when using such carbonized materials, the granular or powdered nitrogen-containing phenol/aldehyde resin used must have fusibility (a)
(with or without).

Regardless of the granular or powdered nitrogen-containing phenol/aldehyde resins, these resins are the result of the growth of cloudy microparticles, which are the initial reaction products of phenols, which further react with formaldehyde; It is extremely stable at room temperature, and since it itself contains a considerable amount of methylol groups, it exhibits reactivity when heated, providing a precursor that is integrated with the first carbonized material.

In addition, since the granular or powdered nitrogen-containing phenol/aldehyde resin used in the present invention is extremely fine particles and has a large surface area as described above, it is easy to uniformly disperse with the first carbonized material. Therefore, even when used in a relatively small amount, a carbon molded body with a high carbonization yield, excellent airtightness, and no gas blisters can be obtained by carbonization firing.

The granular or powdered nitrogen-containing phenol/aldehyde resin used in the method of the present invention is excellent as a carbonization material. The carbonization yield is 50 to 54% by weight when This is clear from the fact that the carbonization yield is 60 to 70% by weight when the mixture is composed of a mixture with 50 parts by weight of a powdered nitrogen-containing phenol/aldehyde resin. The carbonization yield is 54 to 58% by weight when the granular or powdered nitrogen-containing phenol aldehyde resin used in the present invention is carbonized and fired at the same temperature without using it as a precursor molded body. If you also take into account,
The granular or powdered nitrogen-containing phenol/aldehyde resin used in the present invention has reactivity by itself and is also reactive with other resins, so it is possible to obtain a carbon molded body from a precursor molded body with a high carbonization yield. Believable.

When the first carbonized material is mixed with the granular or powdered nitrogen-containing phenol/aldehyde resin and thermoformed to produce a precursor molded body, which is carbonized and fired, a precursor molded body consisting only of the carbonized material is formed. It can be said that when carbonized and calcined, it is possible to give a carbon compact with a high carbonization yield.

What carbonized materials are used in resin compositions? It can also be a second carbonized material. As the second carbonized material,
For example, coke, anthracite, caking bituminous coal, pitch, or a cured product of a thermosetting resin is preferably used.

Although this second carbonized material has relatively low reactivity with the granular or powdered nitrogen-containing phenol/aldehyde resin compared to the first carbonized material, it itself has already been carbonized to a considerable extent or It can be said that a relatively high carbonization yield can be provided. Coke, anthracite, and cured thermosetting resins can act as fillers, pitch as binders, and caking bituminous coal as fillers or binders in the precursor moldings.

In addition, the carbonized material used in the resin composition is further
It can also be a carbonized material.

As the third carbonized material, firstly, carbohydrates, carbohydrate derivatives, or natural products mainly composed of carbohydrates, such as Evercellulose (rayon), starch, and sugar;
Carbohydrate derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, acetyl cellulose, or carbohydrate-based natural products such as wood flour, linters, coconut husk, rice husk, and grain flour; secondly, thermoplastic resins such as polyamide and polyvinyl acetate; , cyclized vinyl, vinylidene chloride or polyacrylonitrile resin,
Alternatively, heat-infusible resins other than cured products of curable resins, such as polyvinyl alcohol or polyvinyl formal, are preferably used.

The above-mentioned third carbonized material generally has a low carbonization yield, and the carbon molded body obtained by carbonizing and firing a precursor molded body using the third carbonized material provides voids and often has voids with an activated inner wall. give. That is, the carbon molded body is obtained as a porous body. According to the method of the present invention, even when a carbon atmosphere molded body is obtained as such a porous body, it is possible to produce a carbon molded body that generally has high strength and high hardness.

In the method of the present invention, the resin composition containing at least a granular or powdered nitrogen-containing phenol/aldehyde resin may further contain an inorganic filler independently of the carbonized material.

The inorganic filler remains in the carbon molded body with its composition as it is or after being reduced, without being carbonized, even when a small precursor molded body different from the above-mentioned carbonized material is carbonized and fired.

Such an inorganic filler therefore imparts properties such as heat resistance and semiconductivity to the resulting carbon molded product by remaining in the carbon molded product, or improves certain properties of the carbon molded product. Used when actively improving. For example, silica, alumina, silica/alumina, calcium carbonate,
Mention may be made of calcium silicate or noble metals such as gold, silver, palladium, platinum, etc. Porous carbon molded bodies containing noble metals can be used as catalysts for reactions in which such noble metals are used as catalysts.

In the method of the present invention, the resin composition containing at least a granular or powdery nitrogen-containing phenol-aldehyde resin is composed of (11) a granular or powdery nitrogen-containing phenol-aldehyde resin and (lI), a curable resin (first carbonized material) and/or the second or third carbonized material or inorganic filler.

In the method of the present invention, when the precursor molded body is composed of the resin composition, the granular or powdered nitrogen-containing phenol aldehyde resin is at least 10% by weight of the total composition.
and the above granular or powdered nitrogen-containing phenol.
Preferably, the thermoformable version of the aldehyde resin (resin (a) above) and/or the second carbonized material, singly or in combination, account for at least 20% by weight of the total composition.

Preferably, the granular or powdered nitrogen-containing phenolic aldehyde resin accounts for at least 20% by weight of the total composition, and the thermoformable granular or powdered nitrogen-containing phenolic aldehyde resin and/or The carbonized materials of 2, alone or in total, are at least 30% by weight of the total composition.
occupies

In particular, the granular or powdery nitrogen-containing phenol-aldehyde resin accounts for 30% by weight of the total composition, and the thermoformable granular or powdery nitrogen-containing phenol-aldehyde resin and/or the second carbonized material It is particularly preferred that the amounts alone or in combination represent at least 40% by weight of the total composition.

As described above, in the method of the present invention, a precursor molded body is first produced by thermoforming from a granular or powdered nitrogen-containing phenol/aldehyde resin alone or a resin composition containing at least a granular or powdered nitrogen-containing phenol/aldehyde resin. .

The resin composition can be produced by mixing the various constituent components as described above, for example, by a method known per se using a mixer, a mill, a roller, or the like.

In order to mold the precursor molded body by thermoforming, in the case of a granular or powdered nitrogen-containing phenol aldehyde resin alone, the temperature must be at least at least the temperature at which the component (a) to be fused is melted (for example, about 50 to about 200 mA). ℃), and in the case of the resin composition, at a temperature at least at least at which the binder component therein melts (e.g., about 100 to about 150°C), by a method known per se, such as injection molding, press molding, or molding. It may be heated and pressurized into a desired shape by molding or the like.

All of these thermoforming methods involve external heating, but according to the present invention, a granular or powdered nitrogen-containing phenolic aldehyde resin that is reactive with itself or with other resins and has very small particles and a large surface area is used. Because of this, when using granular or powdered nitrogen-containing phenol/aldehyde alone, as well as when using a resin composition, it is mutually uniformly dispersed with other resins and can be uniformly dispersed by heating. By reacting and rolling, the obtained precursor molded body is hardened substantially uniformly to the inside, and no decomposition gases that would cause cracks or gas blisters in the carbon molded body are generated during carbonization firing.

In contrast, the precursor molded body manufactured using only resol resin is rounded, with different degrees of hardening depending on the surface area where heat is applied by external heating and the interior area where heat is difficult to transfer, and in many cases the surface area is completely cured. This results in a molded product that is cured but has an uncured interior, which is not desirable for use as a carbon molded product. That is, when a precursor molded body whose inside is uncured is carbonized and fired, decomposition gas is generated from the inside, resulting in a carbon molded body having cracks and gas blisters.

The method of the present invention is then carried out by carbonizing and firing the precursor molded body.

The carbonization calcination is preferably carried out at a temperature of about 450<0>C or higher, more preferably at a temperature between about 100<0>C and about 500<0>C. Furthermore, carbonization firing is carried out under a non-oxidizing atmosphere, usually an atmosphere that does not substantially contain molecular oxygen, for example, containing at least 41 species selected from nitrogen, helium, hydrogen, and carbon monoxide as the main atmosphere gas. Perform under atmospheric conditions.

An appropriate temperature increase rate when carrying out carbonization firing differs depending on the thickness or airtightness of the precursor molded body.

In general, the thicker and more airtight the precursor molding, the
It is desirable to raise the temperature slowly. The heating rate is from about 10'C/hour to about 2000C/hour.

The temperature and atmosphere of carbonization firing have a considerable influence on the properties of the obtained carbon molded body.

For example, when carrying out carbonization firing at a temperature of about 700°C to about 1,000°C in an atmosphere of water vapor, carbon dioxide, a mixture thereof, or a mixture of these and the above-mentioned non-oxidizing gases, a relatively comparative A carbon molded body with a large surface area can be obtained.

Further, for example, the conditions in which carbonization firing is carried out at about 500°C to about 800°C are suitable for producing a carbon molded body with conductivity in the range of semiconductors, and the temperature is about 00°C to about 2000°C.
The conditions in which it actually occurs at .degree. C. are suitable for producing highly conductive carbon molded bodies suitable for heat exchanger pipes, electrodes, and the like.

According to the method of the present invention, as can be seen from the foregoing, a carbon molded body with high strength and hardness can be obtained as a high-density or low-density (porous body) or with a small surface area. Whether to obtain it as a large or small one, to obtain one that exhibits the conductivity of a semiconductor, or one that exhibits the conductivity of a conductor, etc., depends on the type or amount ratio of the constituent components constituting the precursor molded body. Of course, it can be changed to a certain extent depending on the molding conditions of the precursor molded body (for example, it is desirable to heat mold under high pressure to obtain a high-density carbon molded body) or the carbonization firing conditions, such as atmosphere, temperature, etc. be able to.

The carbon molded article obtained by the method of the present invention consists essentially of amorphous carbon. This means that the diffraction angle (2
θ) It was confirmed by the existence of a broad angle around 23 to 24 degrees.

In addition, it is produced by carbonizing and firing at a relatively low temperature according to the method of the present invention using a granular or powdered nitrogen-containing phenol/aldehyde resin (particularly fused or fusion-colored) and another resin as a binder. The carbon molded body may develop a granular or powdery interface by electrolytically etching the carbon molded body using the carbon molded body as an anode.

The nine-carbon molded product obtained by the method of the present invention has excellent strength and hardness, and exhibits excellent heat resistance, abrasion resistance, sliding properties, and chemical resistance.

Therefore, the nine charcoal stamp compact obtained by the method of the present invention can be used, for example, in sliding materials such as bearings, gears, bearings, aviation brakes, motor brushes, etc.; corrosion-resistant materials such as heat exchangers, Raschig rings, bubbler catalyst carriers, etc. ;Heaters such as heaters for electronic equipment and heaters for sorting equipment;Insulating materials such as insulation boards for vacuum furnaces and protective tubes for high temperature furnaces;Electrodes for hydric soda, fuel cells, and scouring;semiconductors, radio waves It can be suitably used for electrical parts such as reflective gaskets; electronic parts; etc.

In addition, it has excellent strength and hardness, and has wear resistance, so it can be used as type type or abrasive grain; it has excellent chemical resistance, so it can be used, for example, as biological aggregate, analytical equipment, or ceramics.・Can also be used as a jig for glass processing.

Furthermore, those with a large specific surface area or those that contain catalytic metals or have been added through post-processing, such as filters such as air filters, ozone filters, water filters, and oil filters; car canisters; and solvent recovery equipment. It can be suitably used as an adsorbent or a catalyst for various reactions.

In particular, those with a large specific surface area and containing nitrogen,
Not only hydrocarbon solvents such as benzene but also heteronomous atoms such as pyridine or mercaptans can be contained from one sample to about 0.
．． Su/Bring 1 ton of Sansol. Such sampling is performed five times from different locations for one sample.

One part of each approximately 0.1 f sample sampled,
Place each on a slide glass for microscopic observation. To make it easier to observe the sample placed on the slide glass, spread it out so that the particles do not overlap as much as possible.

The mold casting observation is performed at locations where 10 to 50 granular or powdery substances and/or secondary aggregates thereof are present in the visual field under an optical microscope.

It is usually desirable to observe at a magnification of 102 to 10''.The size of all particles present in the field of view under the optical microscope is measured using a tape measure in the field of view under the light microscope.

The content (%) of particles with a size of 0.1 to 100 μ is determined by the following formula.

No.: j [Total number of particles whose dimensions were read in the lower visual field Nt: Number of particles having dimensions of 0.1 to 100 μ out of No. 0.0 as the average value of the results of 5 samples for one sample. It represents the content of particles of 1 to 100 microns.

2. Amount of sieve passing through a 150 meter mesh After massaging the dried sample as necessary, lightly knead the sample with #1 by hand, accurately weigh approximately 100 ml of the sample, and measure the amount of 150
Tyler mesh sieving machine (TIN size: 200
wx+d, shake condition; input to 200 RPM+,
After adding the sample, shake for 10 minutes.

The passing amount of 150 tyres/mesh is determined by the following formula.

ω. Two inputs (1) ωs: 150 Amount remaining on the sieve without passing through the Tyler mesh sieve (r) 3. How to measure infrared absorption spectrum and determine absorption intensity (see Figure 1 of the attached drawings) Co., Ltd. Infrared spectrophotometer manufactured by Hitachi (Model 225)
The infrared absorption spectrum was measured for a measurement sample prepared by the usual KBr tablet method.

The absorption intensity at a specific wavelength was determined as follows. In the measured infrared absorption spectrum diagram, draw a baseline at the peak whose absorption intensity is to be determined. If the transmission fund at the top of the peak is expressed as tp, and the baseline transmittance at that wavelength is expressed as tl, then the absorption intensity at that specific wavelength is given by the following equation.

D=log-p Therefore, for example, the ratio of the absorption intensity of the peak from 960 to 10203-' and the absorption intensity of the peak from 1450 to 500 is the ratio of the respective absorption intensities calculated using the above formula (D,...
,. ,. /D 1456~1. . . ) is given as

4. Thermal bonding at 100°C Approximately 5 tons of sample passed through a 350 tier mesh was placed into two 0.
2. Prepare a material inserted between van-thick stainless steel plates, and press it with an initial pressure of 50°C for 5 minutes using a heat press machine (manufactured by Shindo Metal Industry Co., Ltd., single-acting compression molding machine) preheated to 100°C.
Pressed with Kf. After releasing the press, the sample that had been hot pressed between the two stainless steel plates was also taken out. If the sample taken out is clearly fixed to form a flat plate due to melting or fusion, it is determined that the sample has fusible properties, and if there is almost no difference between before and after hot pressing, the sample is judged to be It was judged to be infusible.

5. Precisely weigh about 1Of of a methanol-soluble sample and let the exact weighed weight be wo),
Heat treated under reflux for 30 minutes in about 500 wLl of substantially anhydrous methanol. Filter with a glass filter (A3), and further filter the remaining sample on the filter with approximately 100%
- Wash with methanol, then filter residue sample't
It was dried at a temperature of -40℃ for 5 hours (the exact weight was W8
). Methanol solubility (S0%) was determined using the following formula.

6. Quantification of free phenol content: Accurately weigh approximately 102 samples that passed through 150 tiles,
Heat treated under reflux for 30 minutes in substantially anhydrous methanol 190f. The filtrate filtered through a glass filter (A3) was subjected to high performance liquid chromatography (6000A manufactured by Waters, USA) to quantify the phenol content in the liquid, and the free phenol content in the sample was determined from a separately prepared calibration curve. I asked for

The operating conditions for high performance liquid chromatography are as follows.

Equipment: 6000A column manufactured by Waters Co., USA Carrier: B-Bondapak C1m column: μ inch diameter x 1 ft length Column temperature: room temperature Eluent: methanol/water (3/7, volume ratio) flow
Speed: 0.5m/min Dif/tar: UV (254nm), Range
O,01 (1 mV) The phenol content in the v solution was determined from a previously prepared calibration curve (relationship between phenol content and peak height based on phenol).

7. 10 is cut off at the bulk density index of 10011j
Into the 0- graduated cylinder, place 2 above the edge of the graduated cylinder.
From point υ, pour the sample that passes through the 100 Tyler mesh. The bulk density is determined by the following formula.

W: Weight per 100 (1) 8. Density of carbon molded body The sample was crushed and measured using the float-sink method.

9. Hardness of carbon molded body It was measured using a Vickers microhardness tester under a load of 500 Kf.

10. Bending strength of carbon molded body Measured according to JIS-6911.

11. Gas permeability of carbon molded body Measured by volume change method using helium gas in an apparatus according to ASTM D-1434.

]2. Heat resistance of carbon molded body Temperature rising at a temperature rising rate of 5°C/min in air T, 0
It was measured at the temperature at which weight loss starts using °A device.

13. Grind the X@ diffraction pattern sample of the carbon compact using a tungsten carbide disk type grinder,
CuKCl g was measured using a radial fractometer using a nickel filter.

14. Electrical specific resistance of carbon molded body It was measured by the voltage drop method according to JIS-R-7202.

Reference example] (1) In a 21 C/# twin-hole flask, 11 compositions each of hydrochloric acid and formaldehyde (listed in Table 1) were added at 25°C.
Add 1.500 f into a mixed aqueous solution of
0% by weight of 7 enol, 20% by weight of urea and 14.
A mixed aqueous solution containing 6% by weight of formaldehyde (25% by weight)
℃) and 25f each. After adding it for 15 seconds, it was left to stand for 60 minutes. During the 660 minutes,
The contents of each bottle flask may remain transparent (RunJl and 20ml in Table 1).
), some went from clear to cloudy and remained cloudy (RunJ 3.9 and ]8 of Part 1 II), and others changed from transparent horizontal writing to cloudy and gave a white precipitate (No. 1
RunA2.4-8.10-17 and ]9) in the table. For this white sediment, use a trowel I! Upon inspection, spherical objects, aggregates of spherical objects, and a small amount of powder were already observed. Next, the contents of each separable flask were heated to 80°C for an additional 60 minutes, with occasional stirring, and then heated to 80°C to 80°C.
The reaction product was washed with hot water at 40-45°C for 15 minutes at a temperature of 60°C and treated again for 30 minutes at a temperature of 60°C in a mixed aqueous solution consisting of 0.5% by weight ammonia and 50% by weight methanol. Wash with warm water at 40-45°C and dry at 80°C for 2 hours. The properties of reaction products obtained from mixed aqueous solutions of hydrochloric acid and formaldehyde of various compositions were investigated in the second
1! ! Described in.

e) On the other hand, the following experiment was conducted for comparison. 282 t of distilled phenol, 369 f of formalin of 37% by weight and 150 ft of ammonia water of 26% by weight were placed in a 7-7 rubble flask of No. 11, and the temperature was raised from room temperature to 70°C Kt over 60 minutes with stirring, and then 70-72
The mixture was stirred and heated at a temperature of .degree. C. for 90 minutes. Then let it cool, 3
00F of methanol was added little by little, then dehydration was carried out by azeotropic distillation under a reduced pressure of 40 μHf, and 70 of methanol was added as a solvent to take out a yellow-brown transparent resol tung fat solution.

When a part of the thus obtained resol resin was desolvated under reduced pressure, it foamed violently and turned into a gel. This gelled product was further thermally cured under nitrogen gas at a temperature of 160° C. for 60 minutes, and the resulting cured foam was crushed to obtain a small amount of powder that passed through a 150 Tyler Messier. In this case, the thermosetting resol resin is extremely difficult to obtain, and it is very difficult to obtain powder Yr of 4150 mesh by using various grinding methods, a ball mill, or a percussion mill for fluorescent X-rays. The thermosetting resol resin powder obtained by brazing was heated to zero under the same conditions as described above.
, treated with a mixed aqueous solution consisting of 5% by weight ammonia and 50% by weight methanol, washed with warm water, and then dried. The properties of the sample thus obtained are listed in Table 2 as RunA21.

Next, add phenol 3 to the 11 nanano 9 rubble flask.
G Of, 37111t%F) Formal y370 f
Add 1.5f of oxalic acid and 390f of water, heat to 9011:K for 60 minutes while stirring, and heat to 90-92℃.
The mixture was stirred and heated for 60 minutes at a temperature of . Next, 35% by weight of Hanawa H1,Oft was added, and the mixture was further stirred and heated at a temperature of 90 to 92°C for 60 minutes. Next, add water tsoot and cool it.
Water was removed using a siphon, and the mixture was heated under reduced pressure to 301 HP to maintain a concentration of ]oo for 3 hours, and further heated to 180 C for 3 hours under reduced pressure. The obtained novolak resin was obtained as a tan solid upon cooling. This material has a softening temperature of 78 to 80°C, and a free phenol content of 0.76% by weight as determined by liquid chromatography.
It belonged to

The above novolac resin was crushed, mixed with 15% by weight of hexamethylenetetramite, and the mixture was heated to 16% by weight in nitrogen gas.
It was heat cured at a temperature of 0 DEG C. for 120 minutes, then ground in a ball mill and passed through a 150 tiler mesh. The powder thus obtained was prepared under the same conditions as in point 9 above.
It was treated with a mixed aqueous solution consisting of 5% by weight ammonia and 50% by weight methanol, washed with warm water and then dried.

Properties of the sample thus obtained 1iJLunA22
Listed in the table.

Furthermore, 1 the above novolac resin has a hole diameter of 0.25■φ and a hole number of 1.
Melt spinning was carried out at 136-138° C. using 20 spinnerets. The resulting spun yarn with an average fineness of 21 denier was immersed in a mixed aqueous solution* consisting of salt 1II 11 degrees 18% by weight and formaldehyde concentration 18% by weight at a temperature of 20 to 2]'C for 60 minutes, and then heated to a temperature of 97°C. It took 5 hours to raise the temperature to 97 to 98° C. and was maintained at 97 to 98° C. for 10 hours. The thus obtained cured novolac fibers were treated with a mixed aqueous solution consisting of 0.5% by weight ammonia and 50% methanol under the same conditions as described above after a hot water flow, washed with warm water and then dried. This material was ground with a ball mill. The properties of the material that passed through the 150 Tyler mesh are listed in Table 2 as Run A23.

(3) Table 1 shows the nine hydrochloric acids used, formaldehyde, the total concentration of hydrochloric acid and formaldehyde, the ratio of the weight of the hydrochloric acid-formaldehyde solution to the total weight of phenol and urea, and the formaldehyde (mol) to phenol (mol) urea. c mol) and the total molar ratio is shown.

Table 2 also shows 0,
The content of particles of 1 to 50μ and 0.1 to 100μ, the amount of the obtained sample passed through a t150 Tyler mesh sieve (150 mesh Rs), and the 960 by infrared absorption spectroscopy of the obtained sample ~1020c*-
', 1280~1360m-' and 1580~
1450~ of absorption intensity at 1650cIII-'
Absorption wavelength intensity ratio (I
R intensity ratio).

In the experiments of RunAl, 2.6.17 and 20 in Table fIIJ1, many sticky resins and hard large lumps or plate-like substances were formed at the bottom of the separable flask.

In addition, in experiments with fLunAl, 2 and 20, 4 solids were obtained from the 25f phenol and 25f urea used.
It was obtained in an amount less than 91.

RunAl, 2nd for 2.3.6.17 and 20
Content rate (X) of 0, 1-50# and 0.1-100μ particles listed in the table and ]50 mesh pass (wt%)
The numerical value is the value for granular or powdery materials relative to the total solids including adhesive resin, lumps, and plate-like materials.

However, the content (%) of particles of 0.1 to 50 μ and 01 to 100 in only the granular or powdered solids produced in these experiments and the values of 50 mesh bath C weight %) The respective values are shown in parentheses in Table 2.

From the above experimental facts including the results listed in Table 2, l
un eyebrows 1.2.3.6.17 and 20 are not recommended as manufacturing methods. However, even with these manufacturing methods, it is limited to the granular or powdery products produced, and these granular or powdery products are not sufficiently suitable for use as the granular or powdery nitrogen-containing resin used in the present invention. It has the following characteristics.

FIG. 1 of the accompanying drawings shows an infrared absorption spectrum diagram of the granular or powdery material obtained with RunAl2. Also, in the same @1tN, there is an illustration of how to obtain tb and tb, which are required when determining absorption intensity from an infrared absorption spectrum diagram. A baseline is drawn at a certain peak, and t and tb at that wavelength are determined by K as illustrated.

81 Example 2 A mixed aqueous solution 110 consisting of 18% by weight hydrochloric acid and 11% by weight formaldehyde was placed in 6 reaction vessels in a room at a room temperature of 21-22°C. Into each flask, at a temperature of 23° C., with stirring, add 30% by weight of phenol, 20% by weight of urea and 1% by weight of formaldehyde.
A mixed aqueous solution consisting of 1% by weight was added to #3.34, #2.
66! , 1.60 hours, 1.06 hours, 0.74- and 0
．． Added 45Kf. The bath ratio in this case is 7.0.8.
5.13.5.20.0.28.0 and 45.0. In either case, when the mixed aqueous solution was continued to be stirred after being added, it rapidly became cloudy within 10 to 60 seconds. Stirring was stopped as soon as the mixture became cloudy, and the mixture was allowed to stand for 3 hours. The internal temperature gradually rose, and 30 minutes after the mixture became cloudy, a white slurry or resin-like substance was observed to be produced in each case.

The contents of each were then washed with water while stirring. In this case, a large amount of resin-like cured material was fused to the stirring rod in the yarn with a bath ratio of 7.0, making stirring very difficult.

The contents were then dissolved in a 0.31111-% aqueous ammonia solution at a temperature of 30° C. for 2 hours with slow stirring.
Dry for an hour. The moisture content after drying was 0.5% by weight or less in all cases. The contents are divided into pus from the one with the smaller bath ratio.
unA31.32.33.34.35 and 36.

Table 3 shows the maximum m degree reached in the reaction system from the start of the reaction until 3 hours after it became cloudy, the yield of the reaction product, and the microscopic
*Presence or absence of spherical-order particles, 15% of reaction products
The content of the 150 mesh pass through the mesh, the bulk density of the 150 mesh pass crystal, the thermal fusibility of the reaction product at 100°C, the methanol solubility, and the free phenol content are shown.

In Table 3, RunA21, 22 and 23 (first
The free phenol content of Comparative Example (see table) was measured for the resol resin and novolak resin before heating and was shown within 0.

In Table 3, in the dormitory test of Run A31, sticky resin and lumps amounted to about 80% of the total solids formed at the bottom of the flask. Granular or powdery materials account for only about 20% of the total solid matter produced, and grains account for about 8 of that.
5% passed the m of 100 meshes and mourned. In addition, RunA
The presence or absence of spherical-order particles in No. 31 is small because the proportion of granular or powdery materials in the solid matter is as small as about 20%. Therefore, although the method of Run A31 is not recommended as a manufacturing method, the produced granules or powders have the characteristics of granules or powders suitably used in the present invention.

All of the granular or powdery substances in Run A3] to 36 are
Almost all of the particles had a particle size of 0.1 to 100μ.

Reference Example 3 2oTII 1% m in a 2t separable flask
While stirring a mixed aqueous solution 12501 at 24°C consisting of al' and 8 parts formaldehyde, the weld of phenols and nitrogen-containing compounds diluted to 20 to 80% by weight with 37% formalin was added to the phenols. and the nitrogen-containing compound were added to the iron bath so that the total amount was 5Of. Upon addition of the solution, the mixture became cloudy and instantly turned white, pink, or brown, and stirring was stopped 10 seconds after iron bath g was added. After stopping stirring, the mixture was kept in a still device for 60 minutes, and the temperature was raised to 75° C. over 30 minutes while stirring again, and then maintained at a temperature of 73 to 76° C. for 60 minutes. Each reaction product was washed with water and then treated with 0.3% by weight ammonia and 6%
The sample was treated in a mixed water bath containing 0 weight tX methanol at m/f of 45°C for 60 minutes, washed with water, and then dried at 80°C for 3 hours.

Table 4 shows the types and proportions of the phenols and nitrogen-containing compounds used, the concentration of the diluted solution of the phenols and nitrogen-containing compounds used in formalin, and the addition rate of this diluted solution.
The color of the reaction product after minutes, the yield of the reaction product based on the total amount of phenolics and nitrogen-containing compounds used, the group content of 01 to 50 particles in the reaction product, the 150% of the reaction product The mesh pass amount and infrared absorption spectrum intensity ratio are shown.

1/1-,,-='1' Reference Example 4 18% by weight was added to each of the 6 ]l separable flasks.
1.00 of a mixed aqueous solution containing 9% by weight of formaldehyde and 9% by weight of formaldehyde was added.

The temperature in the room was 115°C. While stirring each of these, 15f of urea was first dissolved, and then 25f of a diluted mixture containing 80% by weight of phenol and 5111% of formaldehyde was added to each at once. In either case, stirring was stopped 10 seconds after the diluent was introduced into the tube and the mixture stood still, but the mixture suddenly became cloudy 8 to 19 seconds after stopping the stirring, and a milky white product was observed.

The temperature of each solution gradually rises from 18℃, and after adding the diluted solution, it reaches 5~
It reached a peak of 31-32°C in 7 minutes and then dropped again.

After adding all the diluted liquid, 0.5 hours (Runn 61), 1 hour (Runn 62), 3 hours (Run 4631.6 hours (
After leaving it at room temperature for 24 hours (Run 65) and 1.72 hours (Run 66), the contents were washed with water and
．． After treatment for 3 hours at a temperature of 15 to 17°C in 75% ammonia water, washed with water, then dehydrated, and treated at a temperature of 40°C for 6 hours.
Dry for 11 hours.

Table 5 shows the passing rate of the obtained dry sample through a 150 tiler mesh sieve, 960 to 102051'''1, R%.
The concentration ratio, methanol dissolution amount, and free phenol content tv were shown. All of the samples of Run Muro 1 to RunA 66 were fused in # fusion test at 100° C. for 5 minutes.

Reference example 5 V & 11100 zo reaction volume with stirring bar! aIc, 1
Pour a 22.5°C mixed aqueous solution t-800Kf consisting of 8.5% hydrochloric acid and 8.5% formaldehyde by weight,
While stirring the mixed aqueous solution, 40 Kt of a mixed aqueous solution of 20% by weight phenol, 10% by weight hydroquinone, and 20% by weight urea at 20° C. was charged.

After adding all of the mixed aqueous solution and stirring for 20 seconds, stirring was stopped and the mixture was allowed to stand for 2 hours. In the reaction vessel, rapid cloudiness was observed 35 seconds after the entire amount of the mixed aqueous solution was added, white granules were gradually formed, and the internal temperature gradually decreased to 35.5°C.
It rose to , and then fell again. Next, while stirring the mixed aqueous solution system of the reaction product again, open the valve attached to the bottom of the reaction vessel to take out the contents, and use a Nomex nonwoven fabric to mix the reaction product and the #1e#. After separating the reaction product from the mixed aqueous solution consisting of formaldehyde and washing and dehydrating it with water, it was immersed in a 0-5 weight ammonia aqueous solution at 8°C for a day and night, and then washed again with water and dehydrated to have a water content of 151% by weight. 29.9 It of reaction product
I got 4.

2, oKf of the obtained loss reaction product by the above method is gA of 40C.
Dry with 1# for 3 hours and sample 1.7 to 9? Got it ( Run
A67).

Table 6 shows the skin content of 01-50t1 and 01-100μ particles of the dried sample obtained in this way, according to the microscopic observation, 150
The sound passing through a Tyler mesh sieve (150 mesh sieves) and the melt solubility are shown.

1/1 Example l RunAl2 product (as filler) ] 00t
and the resol resin used in Run A21 (uncured product, 100 f in terms of solid content) were mixed. The resulting resin mixture was dried at room temperature overnight and then dried in an open dryer at 80° C. for 30 minutes.

A certain amount of the obtained product was processed for 30 minutes under a pressure of 200 Kf△i using a mold preheated to 150°C, and a finished product with dimensions of 20 m in width, 3 cm in thickness, and 120 cm in length was made into 5 parts. I created one.

Similarly, as fillers, the product of RunA30, Ru
nA47 product, RunA30 product, RunA2
Using the product (cured product) obtained in step 2, wood flour, carbon black, and silica powder each passed through a 100-meter mesh sieve, equal amounts of each were mixed with the resol resin used in Rur + A; 2], and the above-mentioned Dimensions of various fillers and resol resin were made using the same method as above, width 20 mm, thickness approx. 3 mm,
Five molded products (precursors) each having a length of 20 cm were prepared.

Next, these precursors were heated from room temperature to 1.0% under nitrogen gas flow.
The temperature was raised to 000°C at a rate of 30°C/hour, and the temperature was further maintained at 1000°C for 60 minutes. Thereafter, it was slowly cooled to obtain a carbonized fired product (carbon compact).

Table 7 shows the ingredients of the filler used, the length retention rate (relative to the precursor) of the carbonized and fired product, the carbonization yield (relative to the precursor), Vickers hardness, gas permeability, and bending strength. showed that.

In Table 7, both the carbonized and fired products of Run A75 and Run A76 had cracks and gas blisters in the /f run, causing them to bend or break, making it difficult to measure the length retention rate. Also, there is a large variation in the opening degree.

Example 2 RunA65 product (as filler) and RunA65 product (as filler) and RunA65 product (as filler)
The resol resins (uncured products) used in 1 were mixed in various proportions (referred to as Runj K79 to Run A86) and air-dried at room temperature for 24 hours, and then dried at a temperature of 60° C. for 60 minutes. Each sample of 5Of was divided into 10 equal parts and processed for 20 minutes under a pressure of 300 to 4/33 using a mold preheated to 150°C in a hot press machine, so that the dimensions were 13 in width. (2) 10 molded products with a thickness of 3.2 to 34 w and a length of 100 mm were obtained for each sample. Next, these molded products (precursor for carbonization firing) were heated from room temperature to 100°C in 30 minutes under a gas flow, held at 100°C for 30 minutes, and then heated again to 1500°C. up to a temperature of 50
After increasing the temperature over time, the temperature was maintained at 1500° C. for 2 hours. Further, while continuing to flow nitrogen gas, the sample was left to cool for 12 hours, and the carbonized and fired sample (carbonized and fired product) was taken out.

Table 8 shows the mixing ratio of the Run A65 product and resol resin (in terms of solid content), the appearance and specific gravity of the precursor, and cracks and gas bubbles in each of the 10 carbonized and fired products in the experiments of Run 79 to Run 86. Items in which no noticeable deterioration is observed (
number of good products), specific gravity measured using good products, carbonization yield,
The bending strength and electrical resistivity were shown.

Since a good product was not obtained for Run A179, only the specific gravity and carbonization yield are shown.

In addition, a glass-like luster was observed on the fractured surface of each carbonized and fired product, and the X-ray diffraction pattern had a broad peak around 22 to 24''.

Example 3 40 precursor samples consisting of 40 parts by weight of the product of Run A41 (as a filler) and 60 parts by weight of the resol resin (uncured product, solid content) used in Run A21 were prepared in the same manner as in Example 2. Created.

65 samples each were heated from room temperature to 4 times under helium gas flow.
350°C (RunA871.450
°C (RunA88), 550 °C (RunA89), 65
0℃ (Run 90), 800℃ (Run 491),
1000℃ (RunA92), 1500℃ (RunA9
31.1800t: (Run491) or 2100℃
(Run 491), held at each temperature (carbonization temperature) for 3 hours, and then allowed to cool.

Table 9 shows the carbon content, specific gravity, bending strength, electrical resistivity, and X-ray diffraction angle of each carbonized and fired product obtained by elemental analysis.

Example 4 Production of RunA13 product (1501 J! parts as filler, resol resin (uncured product) used in RunA21, novolak resin C obtained in Run 22 containing 10% by weight of hexamethylenetetramine), RunA63 product (thermal adhesive bacteria), RunA67 product (thermal adhesive bacteria), furan resin (Hitafuran-303; Hitachi Chemical Co., Ltd.)
), epoxy resin (Epikoat 815; Shell Chemical (
Co., Ltd.) or coal tar pitch (softening point: 125°C, quinoline solution 13.6%; Allied Chemical Co., Ltd.)
and 50 parts by weight of each in terms of solid content were mixed according to the method of Example 2 to obtain mixtures of each acetate composition.

Next, 2.5 f of mixtures of various compositions were taken per sample and molded according to Example 2, and the dimensions were 13 mm in width.

Molded product (precursor) with a thickness of 1.5 to 17 cm and a length of 100 m
I obtained 10 pieces of each. The precursor obtained by the above method was heated gradually from room temperature to 1000°C over 24 hours while flowing nitrogen gas, maintained at 1000°C for 60 minutes, and then allowed to cool.

Table 10 shows the type of resin used, the number of samples (good products) with no cracks or gas blisters among the 10 samples obtained by carbonization firing, and the carbonization yield and bending strength of the good products. Ta.

Example 5 A product of 50% of the total weight, 100% of coconut husk powder, 100% of flour, 100% of polyvinyl alcohol or 100% of flour, previously heat treated at a temperature of 500C under a nitrogen atmosphere and then pulverized.
Five types of mixtures (Run & 103 to Run A 10
7), or the product of Run A 35 (Run
s 10g) from a single small extruder (manufactured by Sumitomo Heavy Industries, Ltd., type: 3AGM) to 150℃ I7) m
A rope of 2 to 3 degrees was extruded. After that, cool it with water for about 1
The pieces cut to a length of 0 m were dried at a temperature of 80° C. for 5 hours to obtain a precursor for carbonization and firing.

Next, the above precursor was heated from a temperature of 900°C to 900°C while continuing to feed water vapor-containing nitrogen passed through hot water at 80°C.
The temperature was raised to 900° C. in 60 minutes, and the temperature was further maintained at 900° C. for 30 minutes, and then cooled and taken out.

Table 11 shows the type and composition of the raw materials used, the carbonization yield of the carbonized and fired product (relative to the precursor), the apparent density, and the BET method (N!
The specific surface area and equilibrium adsorption amount of benzene at 20°C are shown.

Example 6 65 parts by weight of the uncured novolac resin used in Run A 22 (compounded with 10% hexamethylene tetramite) was used as a matrix, and Run A was used as a filler.
12 products, Run A 64 products, Run A
3 each of Run A21 powder (cured product), Run A22 powder (cured product), and Run A 23 powder (cured product).
5 parts by weight of the powder was mixed into a melter preheated to 160°C, and extruded from a nozzle with a diameter of Im under a pressure of 511w/am'' to form a gold plate with dimensions of 50w square and 10m deep. Each of the plate-like products thus obtained was cooled to room temperature, then heat-treated in a drying oven heated to 8oC for 8 hours, and then at 120C for 4 hours, and then removed from the mold. The precursor was obtained by pulverizing the powder and passing it through a 20 mesh sieve.

Next, the precursor obtained by the above method was left standing in an electric furnace, and 8
While continuing to feed the steam-containing rope passed through hot water at 5°C, the temperature inside the furnace was raised from room temperature to 850°C over 90 minutes, and maintained at 850°C for another 60 minutes.

Table 12 shows the type of filler used, the extrudability of the mixed powder from the nozzle, the nitrogen content determined by elemental analysis of the carbonized and fired product, the specific surface area determined by the BET method (Nt method), and the adsorption amount of ethyl mercaptan. .

[Brief explanation of drawings]

FIG. 1 of the accompanying drawings is an infrared absorption spectrum diagram of an example of a granular or powdery nitrogen-containing phenol formaldehyde resin used in the present invention. FIG. 1 also illustrates a method for determining the absorption intensity at a specific wavelength of the peak.

Claims (1)

[Scope of Claims] 1. A granular or powdered resin comprising a phenol, a nitrogen-containing compound having at least two active hydrogens, and a condensate with an aldehyde, wherein (A) the iron granular or powdered resin is Contains spherical-order particles with a particle size of 0.1 to 100 microns and secondary aggregates thereof, and (B) has the largest absorption in the range of 1450 to 1500 cm in the infrared absorption spectrum of the resin by the KBr tablet method. Intensity D14s0~1. . ol and 960~1020~
Moths in the range -1 also have a large absorption intensity, and when expressed as 6° to 1°, D @@g--1616 / DI416-11B1
6 to 0.1 to 2.0, or thermoforming a precursor molded body solely from the thermoformable particulate or powdered nitrogen-containing phenol aldehyde resin, and then carbonizing and firing the precursor molded body. A method for producing a carbon molded body. 2. The method according to claim 1, wherein at least 30% of the granular or powdered nitrogen-containing resin is composed of spherical particles having a particle size of 0.1 to 0.00 microns and secondary aggregates thereof. 3. The granular or powdered nitrogen-containing resin has an infrared absorption spectrum of 1280 to 136 by KBr tablet method.
0ctn-" (absorption peak attributed to carbon-nitrogen bonds), the largest absorption node in the range N 'k D 1 * no
-l5o. When expressed as D, 180-'-131+6/D 14 B6~
156°" 0.15 to 3.0. 4. The granular or powdered nitrogen-containing resin has a D* in an infrared absorption spectrum measured by the KBr tablet method. so, zot
The method according to any one of claims 1 to 3, wherein o/DI450 to 1800 is 0.15 to 0.6. 5. The granular or powdered nitrogen-containing resin has an infrared absorption spectrum of D1! according to the KBr tablet method. @O~l1
110/D1480~15Otl is 0.2 to 2.0, the method according to any one of claims 1 to 4. 6. The granular or powdered nitrogen-containing resin has D 1110 to 11 in the infrared absorption spectrum measured by the KBr tablet method.
116/DI4110-! The method according to any one of claims 1 to 5, wherein Woo is 0.3 to 1.5. 7. The granular or powdered nitrogen-containing resin contains at least 5 of the total
7. The method according to any one of claims 1 to 6, wherein 0% by weight has a size that allows it to pass through a 150-meter mesh sieve. 8. The granular or powdered nitrogen-containing resin has a free phenol content of 50% as measured by liquid chromatography.
The method according to any one of claims 1 to 7, wherein the content is 0 ppm or less. 9. The method according to any one of claims 1 to 8, wherein the granular or powdered nitrogen-containing resin contains at least II amount % of element 9. 10. The granular or powdered nitrogen-containing resin contains 2 to 30 nitrogen.
10. The method according to any one of claims 1 to 9, wherein the method contains % polypropylene. 11. The claim that the granular or powdered nitrogen-containing resin is at least partially fused when held at a temperature of 100°C for 5 minutes according to the heating fusion measurement method described in the main text. The method according to any one of items 1 to 10. 12. When the granular or powdery nitrogen-containing resin 10F is heated under reflux in substantially anhydrous methanol 50011j, in the following formula, Wo is the weight (f) of the resin used, and W is the heating The weight (f) of the resin remaining after reflux, S represents the methanol solubility (wt%) of the resin, and the methanol solubility represented by the following is 20 wt% or more, any one of claims 1 to 11 Method described in Crab. 13. Claims 1 to 10 that the granular or powdered nitrogen-containing resin does not substantially melt or fuse when held at a temperature of 100°C for 5 minutes according to the thermal fusion measurement method described in the main text. The method described in any of the paragraphs. 14. The thermoformable part of the granular or powdered nitrogen-containing resin alone has a temperature of 10% according to the heat fusion measurement method described in the text.
It consists of a substance that at least partially fuses when held at a temperature of 0°C for 5 minutes, or substantially melts or melts when held at a temperature of 100°C for 5 minutes according to the same thermal fusion measurement method. 2. A method according to claim 1, comprising: non-fusing. 15. At a temperature of 100°C according to the heat fusion measurement method described above.
It consists of a material that at least partially fuses when held for a minute and a material that does not substantially melt or melt, and at least 10% by weight of the total material that is at least partially fused.
15. The method of claim 14, wherein the method comprises: 16. The method according to claim 1, wherein the thermoformable resin composition further comprises another carbonized material in addition to the granular or powdery nitrogen-containing resin. 17. The method according to claim 16, wherein the carbonized material is a first carbonized material that is a curable resin. 18. The method according to claim 17, wherein the first carbonized material is a thermosetting resin. 19. The method according to claim 18, wherein the thermosetting resin is a resol resin, a novolak resin, an epoxy resin, a furan resin, a melamine resin, or a urea resin. 20. The method according to claim 16, wherein the carbonized material is a second carbonized material selected from coke, anthracite, caking bituminous coal, bicarbonate, or a cured product of a thermosetting resin. . 21. The carbonized material is a carbohydrate, a carbohydrate derivative,
or the second carbonized material selected from natural products containing carbohydrates as a main component. 22. The method according to claim 21, wherein the carbohydrate is cellulose, starch or sugar. 23. The method according to claim 16, wherein the carbonized material is a third carbonized material selected from a thermoplastic resin or a heat-insoluble resin other than a cured product of a curable resin. 24. The method according to claim 23, wherein the thermoplastic resin is polyamide, polyvinyl acetate, vinyl chloride, vinylidene chloride, or polyacrylonitrile resin. 25. The method according to claim 23, wherein the heat-infusible resin is polyvinyl alcohol or hapolyvinyl formal. 26. The method according to claim 1 or 16, wherein the thermoformable resin composition further contains an inorganic filler. 27. The method according to claim 26, wherein the inorganic filler is silica, alumina, silica-alumina, calcium carbonate, calcium silicate, or a noble metal. 28. The thermoformable resin composition may include (a) a granular or powdered phenol aldehyde nitrogen-containing resin and (c) a curable resin (first carbonized material) and/or (C) the above-mentioned 2 or 3 carbonized material or inorganic filler, the granular or powdered nitrogen-containing resin of (al) is at least 11011ffi'% of the total composition, and (a)
The aged form of the granular or powdered nitrogen-containing resin and/or the second carbonized material of the above (bl) alone or in total amount is at least 20% by weight of the total composition. The method according to item 1. things and/
29. The method of claim 28, wherein the second carbonized material of (b), alone or in total, is at least 30% by weight of the total composition. 30. The granular or powdery nitrogen-containing resin of the above (30) is at least 30% by weight of the total composition, and the thermoformable granular or powdery nitrogen-containing resin of the above (al) and/or the above ( 29. The method of claim 29, wherein the amount of the second carbonized material of the bl, alone or in total, is at least 40% by weight of the total composition. 31. The carbonization calcination is carried out at a temperature of about 450° C. or higher. 32. The method of claim 31, wherein the carbonization calcination is carried out at a temperature between about 500 and about 2500<0>C. 33. The method according to any one of claims 1 to 32, wherein the carbonization firing is performed in a non-oxidizing atmosphere. 34. A patent in which the non-oxidizing atmosphere does not substantially contain molecular oxygen. The method according to claim 33. 35. Claim 35, wherein the non-oxidizing atmosphere contains at least one element selected from 9 elements, helium, hydrogen, and carbon oxide as the main atmospheric gas. The method according to claim 33 or 34. 36. The method according to any one of claims 1 to 32, wherein the carbonization firing is carried out in an atmosphere containing steam or carbon dioxide.