JPS59207822A - Production of carbon material - Google Patents

Abstract

PURPOSE:To produce a carbonaceous material having a high strength and density at a low cost, by heating a heavy oil containing a nitrating agent added thereto under reduced pressure, treating the heated heavy oil while removing distilled oil, pulverizing the treated resultant pitch, molding the resultant powder, and carbonizing the molded material. CONSTITUTION:10wt% or less nitrating agent, e.g. nitric acid or acetyl nitrate, is added to a heavy oil, e.g. coal tar formed as a by-product in carbonization of coal or residual oil in thermal cracking of crude oil, at <=0.85 atomic ratio (H/C), and the resultant mixture is heated at 400-530 deg.C under 3,000mm.Hg reduced pressure to polycondense the heavy oil while distilling oil therefrom. The resultant pitch is then pulverized to give powder, which is molded without using a binder and carbonized at about one thousand several hundreds of degrees deg.C(or graphitized at about two thousand several hundreds of degrees deg.C) to afford the aimed carbon material.

Description

【発明の詳細な説明】 〔発明の技術分野〕 本発明は重質油から高強度高密度炭素材料を製造する方
法に関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for producing high strength, high density carbon materials from heavy oil.

〔発明の技術的背景とその問題点〕[Technical background of the invention and its problems]

放電加工用電極、メカニカルシール材、原子力用黒鉛材
１．ホットプレス用押型等に使用さｎる高強度高密度炭
素材料の製造方法は、従来、コークスあるいは黒鉛等を
粒径１０μｍ以下に微粉砕し、これにコールタールピッ
チ等のバインダーを加え熱間混線したのち、再び粉砕し
、成型、焼成、さらにタールピッチ等の含浸、再焼成を
くり返して製造されるもので、工程が極めて複雑で手間
のかかるものであった。さらにコークスあるいは黒鉛等
の骨材とバインダーの収縮率の違いによる微小クラック
の発生、骨材の持つ気孔の焼成後の残存、バインダーに
含まれる揮発物のガス化による気孔の発生等種々の問題
があり、高強度高密度炭素材料の製造が難しくその価格
は高価なものであった。従って、より安価で、高品位の
高強度高密度炭素材料を得るために従来から種々検討さ
れている。Electrodes for electrical discharge machining, mechanical seal materials, graphite materials for nuclear power 1. Conventionally, the manufacturing method for high-strength, high-density carbon materials used in hot-press molds, etc. is to finely grind coke or graphite to particles with a particle size of 10 μm or less, add a binder such as coal tar pitch, and heat cross-mixing. After that, it is manufactured by repeatedly pulverizing it, molding it, firing it, impregnating it with tar pitch, etc., and firing it again, making the process extremely complicated and time-consuming. Furthermore, there are various problems such as the occurrence of micro-cracks due to the difference in shrinkage rate between aggregates such as coke or graphite and the binder, pores in the aggregate remaining after firing, and the formation of pores due to the gasification of volatiles contained in the binder. However, it is difficult to manufacture high-strength, high-density carbon materials, and the price is high. Therefore, various studies have been made in the past in order to obtain inexpensive, high-grade, high-strength, high-density carbon materials.

たとえば原料粉の調整方法として、■特開昭５５−１３
０８６４号公報では、粘結材を含まない無定形炭素粉末
あるいは人造黒鉛質粉末に焼結促進剤として種々の硼化
物（ＡｌＢ１２あるいはＬ　ａ　Ｂ６粉末）を添加し、
加圧下１９００℃以上で焼成する方法、■特開昭５６−
５３１０号公報においてはコールタールピッチを３５０
℃〜６００℃で熱処理し、熱処理ピッチ中のβ成分の全
量または一部を抽出残ピッチに残すような条件下で溶剤
抽出し、■焼処理を施して収焼品を得て、その捷まある
いは微粉砕したのちに、バインダーを使用せずに高密度
炭素材を製造する方法、■特開昭５６−２２６１５号公
報において、石油系重質油またはコールタールピッチを
熱処理し、生成するメンフェーズ（光学的異方性小球体
）を溶剤分別法にて分離し、高密度炭素材料の原料を製
造する方法が提案さ扛ている○これらの方法はいずれも
原料粉自身が骨材−とバインダー性の両性質を兼ね、自
己焼結性を持たせてクラックの発生あるいは気孔の発生
を防ぎ高強度高密度炭素材を製造する試みである。とこ
ろか■の方法では焼結促進剤として添加する硼化物の灰
分が残留するし、加圧（数百〜あるいはそれ以上）焼成
は生産性が低く経済的に不利である。For example, as a method for adjusting raw material powder,
In Publication No. 0864, various borides (AlB12 or L a B6 powder) are added as a sintering accelerator to amorphous carbon powder or artificial graphite powder that does not contain a binder,
Method of firing at 1900°C or higher under pressure, ■ JP-A-56-
In Publication No. 5310, the coal tar pitch is 350
Heat treated at ℃ to 600℃, extracted with solvent under conditions such that all or part of the β component in the heat-treated pitch remains in the extracted pitch, subjected to calcination treatment to obtain a burnt-out product, and then shredded. Alternatively, a method for producing high-density carbon material without using a binder after finely pulverizing it is described in Japanese Patent Application Laid-Open No. 56-22615. A method has been proposed in which the raw material for high-density carbon materials is produced by separating (optically anisotropic spherules) using a solvent fractionation method. In both of these methods, the raw material powder itself contains aggregates and binders. This is an attempt to produce a high-strength, high-density carbon material that has both carbon properties and self-sintering properties to prevent the generation of cracks and pores. However, in method (2), the ash of the boride added as a sintering accelerator remains, and pressurized firing (several hundred or more) has low productivity and is economically disadvantageous.

■の方法では引火性で毒性を有するベンゼンを溶剤とし
て使用するため、安全、衛生上の問題が多く、さらに不
溶分の分離、不溶分から溶剤の回収、不溶分の百方ｆｆ
熱処理等、工程が複雑で製造コスト高となる。また■の
方法ではメンフェーズの単離採取が難しく収率が低いと
いった問題点がある。Method (2) uses flammable and toxic benzene as a solvent, so there are many safety and hygiene problems.
Processes such as heat treatment are complicated and manufacturing costs are high. In addition, method (2) has the problem that it is difficult to isolate and collect menphase and the yield is low.

〔発明の目的〕[Purpose of the invention]

本発明は、上記問題点を解決すべくなされたものであり
、Ｈ／Ｃが０，８５以下の重質油から、揮発分が少なく
骨材とバインダーの両性質を兼ね、自己焼結性の原料粉
を高収率で得、これを成型し、焼成することにより製造
工程も単純化でき、安価な高強度、高密度の炭素材料の
製造方法を提供するものである。The present invention was made to solve the above problems, and is made from heavy oil with H/C of 0.85 or less, which has low volatile content, has both aggregate and binder properties, and has self-sintering properties. By obtaining raw material powder at a high yield, molding it, and firing it, the manufacturing process can be simplified, and an inexpensive method for manufacturing a high-strength, high-density carbon material is provided.

〔発明の概要〕[Summary of the invention]

上記目的を達成するための本発明の要旨とするところは
、水素と炭素の原子比Ｈ／Ｃが０８５以下の重質油に、
ニトロ化剤を１０ｗｔ１以下添加し、４００〜５３０℃
に加熱し、加熱過程で３００ｍｍＨｊｉ以下に減圧し留
出する油分を除去して得られるピッチを粉砕し、成型し
、炭化または黒鉛化することを特徴とする炭素材料の製
造方法である○ 〔発明の具体例〕 さらに本発明を詳述する。The gist of the present invention to achieve the above object is to use heavy oil with an atomic ratio of hydrogen to carbon H/C of 085 or less.
Add 10wt1 or less of nitrating agent and heat at 400-530℃
This is a method for producing a carbon material, characterized in that the pitch obtained by heating the pitch to 300 mmHji or less and removing distilled oil during the heating process is crushed, molded, and carbonized or graphitized. Specific Examples] The present invention will be further described in detail.

この発明における重質油としては石炭乾留時ニ産出する
コールタールやアスファルト、原油の熱分解で生成する
重質油、エチレンボトム油、あるいはこれらを蒸留、抽
出、分解重合処理した重質油を用いることができ、その
水素と炭素の原子比Ｈ／Ｃが０．８５以下の芳香族性重
質油が用いられるＯＨ／Ｃが０．８５を超える重質油は
、芳香族性が低く、アルキル側鎖の多い重質油であシ、
本発明に従うニトロ化剤によるニトロ化反応が生じ難く
、重縮合を充分行うことができない。As the heavy oil in this invention, coal tar and asphalt produced during coal carbonization, heavy oil produced by thermal decomposition of crude oil, ethylene bottom oil, or heavy oil obtained by distilling, extracting, cracking and polymerizing these are used. Aromatic heavy oil with an atomic ratio of hydrogen to carbon H/C of 0.85 or less is used. Heavy oil with an OH/C of more than 0.85 has low aromaticity and alkyl Heavy oil with many side chains,
The nitration reaction by the nitration agent according to the present invention is difficult to occur, and polycondensation cannot be carried out sufficiently.

上記重質油にニトロ化剤を１０ｗｔ％以下で添加される
。このニトロ化剤としては希硝酸、濃硝酸、硝酸アセチ
ル、二酸化チノ素等が用いら扛る０ニド占化剤の添加目
的は次の工程で４００〜５３０℃に加熱した際、メンフ
ェーズの生成を妨げないで重縮合を進め、原料粉にバイ
ンダー性を持たせながら炭化歩留りを増加させ、原料粉
収率の向上を計ることにあるＯ 元来、ベンゼン、ナフタ／ン等の低分子ｔ。A nitrating agent is added to the heavy oil in an amount of 10 wt% or less. As this nitrating agent, dilute nitric acid, concentrated nitric acid, acetyl nitrate, tinoxide dioxide, etc. are used. The objective is to proceed with polycondensation without interfering with the raw material powder, increase the carbonization yield while imparting binder properties to the raw material powder, and improve the raw material powder yield.

芳香族系炭化水素のニトロ化は、硝酸に硫酸を加えた混
酸で行なわれる。しかるに本発明の重質油はベンゼン縮
合環が３以上の多環式化合物が主成分であり、硝酸との
反応性に富み、自ら発熱してニトロ化反応が進む。従っ
てニトロ化反応は極めて容易であり、圧力、温度等の反
応条件を制御する必要はないが、少量のニトロ化剤を有
効使用するために加熱してもよい０もしニトロ化剤を１
０ｗｔ％以上添加した場合は、重縮合によシ重質油の粘
度が異常に上昇し、メンフェーズの生成が進みにくく、
原料粉のバインダー性も失われ、自己焼結性もなくなり
、本発明の目的に達しない○ さらに、ニトロ化しｆｃＭ質油を４０゛０〜５３０℃に
加熱するのであるが、ニトロ化重質油は加熱昇温過程で
ニトロ基が遊離し、ラジカルの発生によシ重縮合がさら
に進むためニトロ化工程て重合時間を設ける必要はない
。この点もニトロ化重合の特徴である。このとき、４０
０〜５３０℃の加熱過程で重縮合を行なうと同時に、３
００　ｒ、＋ｍ　Ｈ＆以下に減圧し、加熱過程で発生す
る分解油や、もともと重質油に含まれていた低分子化合
物を除去することに９より、重質油の濃縮およびメソフ
ェーズの生成の促進、さらに後の工程の成型体の焼成過
程で揮発する成分の大部分を、この過程で除去して、焼
成過程での発泡を防ぐ。Nitration of aromatic hydrocarbons is carried out using a mixed acid consisting of nitric acid and sulfuric acid. However, the heavy oil of the present invention is mainly composed of a polycyclic compound having three or more benzene condensed rings, has high reactivity with nitric acid, and generates heat by itself to proceed with the nitration reaction. Therefore, the nitration reaction is extremely easy, and there is no need to control reaction conditions such as pressure and temperature. However, in order to effectively use a small amount of nitration agent, it may be heated.
If it is added in excess of 0 wt%, the viscosity of heavy oil will abnormally increase due to polycondensation, making it difficult for the production of menphase to proceed.
The binder property of the raw material powder is also lost, and the self-sintering property is also lost, so the purpose of the present invention cannot be achieved.Furthermore, the nitrated heavy oil is heated to 40°C to 530°C, but the nitrated heavy oil Since the nitro group is liberated during the heating process and the polycondensation further progresses due to the generation of radicals, there is no need to provide a polymerization time in the nitration step. This point is also a feature of nitration polymerization. At this time, 40
Polycondensation is carried out in the heating process at 0 to 530°C, and at the same time, 3
By reducing the pressure to below 00 r, +m H& and removing the cracked oil generated during the heating process and the low molecular weight compounds originally contained in the heavy oil, the concentration of heavy oil and the generation of mesophase are promoted. Most of the components that volatilize during the subsequent firing process of the molded body are removed in this process to prevent foaming during the firing process.

ここで加熱温度が４００℃未満の場合はニトロ化による
重縮合は充分進むが、メソフェーズの生成に長時間を要
し、減圧による油分除去の効果も小さく、これを原料と
して粉砕、成型、焼成しても発泡してしまい良質の炭素
材料は得られない。また、加熱温度が５３０℃を超える
場合は重縮合が進み過ぎて、原料のバインダー　、性が
失なわれ、成型できない。なお、減圧する除圧が３００
朋Ｈｐを超えると、４００〜５３０℃加熱過程における
油分の除去が充分行なわれず、原料のバインダー性は良
く成型は容易であるけれども、焼成過程での揮発分によ
る発泡あるいは変形が起こり高強度高密度炭素材料は得
られない○ 上記方法により製造した原料は粉砕したのち、バインダ
ーを使用することなく成型する。成型方法は片押しプレ
ス、両押しプレス、ラバープレスによるか、あるいはク
レオソート油等を添加して押し出し成型を行なってもよ
い。成型は室温で充分行なうことができ、焼成前の成型
体はハンドリングに耐える強度を有するＯ成型体の形状
は棒状、パイプ状、柱状等任意に選ぶことができる。If the heating temperature is below 400°C, polycondensation through nitration will proceed satisfactorily, but it will take a long time to generate mesophase, and the effect of removing oil under reduced pressure will be small. However, foaming occurs and a high-quality carbon material cannot be obtained. Furthermore, if the heating temperature exceeds 530°C, polycondensation will proceed too much and the binder properties of the raw materials will be lost, making it impossible to mold them. In addition, the pressure to be reduced is 300
If the Hp is exceeded, oil content will not be removed sufficiently during the heating process of 400 to 530°C, and although the binder properties of the raw material are good and molding is easy, foaming or deformation due to volatile matter during the firing process will occur, resulting in high strength and high density. No carbon material is obtained. The raw material produced by the above method is pulverized and then molded without using a binder. The molding method may be one-sided press, double-press press, rubber press, or extrusion molding by adding creosote oil or the like. Molding can be sufficiently carried out at room temperature, and the shape of the O-shaped body before firing has a strength sufficient to withstand handling, and the shape of the O-shaped body can be arbitrarily selected, such as a rod, a pipe, or a column.

次に成型体を千数百℃で炭化あるいは二手数百℃で黒鉛
化し炭素材料を製造する。焼成条件は成型体の形状に応
じ昇温速度を任意に選んで焼成するが、成型体は不活性
ガスあるいは粉コークス中で焼成し酸化されるのを防ぐ
○〔実施例および比較例〕 （実施例） 第１表に示す実施例１〜６はＨ／Ｃが０．８５以下のコ
ールクールあるいはエチレンボトムピッチ等に７０係濃
度の硝酸または硝酸アセチル等のニトロ化剤を１０ｗｔ
％以下で添加し、４００〜５３０℃で加熱し、加熱中に
３００η＋ｉＨ，９以下の減圧で留出する油分を除去し
て第１表（右側欄）に示す性状の素原料を得た。Next, the molded body is carbonized at several hundred degrees Celsius or graphitized at several hundred degrees Celsius by hand to produce a carbon material. The firing conditions are determined by arbitrarily selecting the heating rate depending on the shape of the molded body, but the molded body is fired in an inert gas or coke powder to prevent it from being oxidized. Example) In Examples 1 to 6 shown in Table 1, 10 wt of a nitrating agent such as nitric acid or acetyl nitrate with a concentration of 70 parts was added to coal cool or ethylene bottom pitch with an H/C of 0.85 or less.
% or less, heated at 400 to 530°C, and removed the oil distilled out under reduced pressure of 300η+iH and 9 or less during heating to obtain raw materials having the properties shown in Table 1 (right column).

この素原料をボールミルで１０μｍ以下に粉砕し、片押
しプレスで室温で５００〜２０００〜で加圧し成型サイ
ズ６０φ×３０ｙｎｒｎの円柱に成型したのち、粉コー
クス中で０３℃／ｒｔ＋ｍで１２００’Ｃ−ｉで昇温し
炭化物を得た。さらにこの炭化物をＡｒ雰囲気中で１０
℃／ｍｍ　２８００℃まで昇温し黒鉛化した。その結果
を第２表に示す。This raw material was ground to 10 μm or less in a ball mill, pressurized at 500 to 2000 at room temperature using a single-press press, and formed into a cylinder with a molding size of 60φ x 30ynrn, and then heated to 1200'C- The temperature was raised at i to obtain a carbide. Furthermore, this carbide is mixed with 10
°C/mm The temperature was raised to 2800 °C to graphitize. The results are shown in Table 2.

（比較例） 第１表に示す比較例１〜４は実施例と同じ手順で炭素材
料を製造したものであるが比較例］はＨ／Ｃ＝　１．．
７５　（＞０．８５　）で芳香族性の低い重質油を使用
した場合、比較例２はニトロ化剤としての硝酸を１２ｗ
ｔ％添加したもの、比較例３はニトロ止剤添加後の温度
を３８０℃（＜４００℃）にしたもの、比較例４はニト
ロ止剤添加後の温度を５５０”Ｃ（）５３０℃）にした
ものであυ、さらに実施例と同一条件で、粉砕、成型、
炭化、黒鉛化したものである。結果を第２表に示す。(Comparative Example) In Comparative Examples 1 to 4 shown in Table 1, carbon materials were manufactured using the same procedure as in the Examples, but in Comparative Example, H/C=1. ．．
75 (>0.85) and low aromaticity, Comparative Example 2 uses 12w of nitric acid as a nitrating agent.
Comparative Example 3 has a temperature of 380°C (<400°C) after adding a nitro stopper, and Comparative Example 4 has a temperature of 550"C (< 530°C) after adding a nitro stopper. υ, and was further crushed, molded, and molded under the same conditions as in the example.
It is carbonized and graphitized. The results are shown in Table 2.

（考察） 第１表、第２表で明らかなように、本発明方法実施例に
おける素原料の光学異方性は比較例と比べ９９係と高く
メソフェーズの生成が犬であることがわかる。さらに炭
化物の性状も嵩密度−硬度、曲げ強度いずれも比較例と
比べ大きく、電気比抵抗は比較例に比べ低くなっている
。(Discussion) As is clear from Tables 1 and 2, the optical anisotropy of the raw materials in the Examples of the method of the present invention is as high as 99 compared to the Comparative Examples, indicating that the generation of mesophase is superior. Furthermore, the properties of the carbide include bulk density-hardness and bending strength, which are both higher than those of the comparative example, and electrical resistivity is lower than the comparative example.

黒鉛化物の性状も同様である。The properties of graphitized materials are also similar.

〔発明の効果〕〔Effect of the invention〕

以上のように本発明方法によると、Ｈ／Ｃが０．８５以
下の重質油から骨材とバインダーの両性質を兼ね、自己
焼結性の原料粉を高収率で得ることができ、さらにこれ
を成型し焼成することにより製造工程も単純化でき安価
な高強度、高密度の炭素材料が製造できる。As described above, according to the method of the present invention, a self-sintering raw material powder that has both aggregate and binder properties can be obtained at a high yield from heavy oil with an H/C of 0.85 or less. Furthermore, by molding and firing this material, the manufacturing process can be simplified and an inexpensive, high-strength, high-density carbon material can be manufactured.

特許出願人　　　住友金属工業株式会社１３Patent applicant: Sumitomo Metal Industries, Ltd. 13

Claims (1)

【特許請求の範囲】[Claims] （１）水素と炭素の原子比Ｈ／Ｃが０．８５以下の重質
油に、ニトロ化剤を１０ｗｔ係以下添加し、４００〜５
３０℃に加熱し、加熱過程で３００７ｎｍＨ９以下に減
圧し留出する油分を除去して得られるピッチを粉砕し、
成型し、炭化または黒鉛化することを特徴とする炭素材
料の製造方法。(1) Add a nitrating agent of 10 wt or less to heavy oil with a hydrogen to carbon atomic ratio H/C of 0.85 or less.
The pitch obtained by heating to 30 ° C. and reducing the pressure to 3007 nmH9 or less during the heating process to remove distilled oil is crushed,
A method for producing a carbon material, characterized by molding and carbonizing or graphitizing.