JP2006151797A - Spherical carbon particle aggregate and manufacturing method thereof - Google Patents

Spherical carbon particle aggregate and manufacturing method thereof Download PDF

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JP2006151797A
JP2006151797A JP2005313114A JP2005313114A JP2006151797A JP 2006151797 A JP2006151797 A JP 2006151797A JP 2005313114 A JP2005313114 A JP 2005313114A JP 2005313114 A JP2005313114 A JP 2005313114A JP 2006151797 A JP2006151797 A JP 2006151797A
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particles
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spherical carbon
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Hiroyuki Aikyo
浩幸 相京
Toshifumi Shiratani
俊史 白谷
Masaki Yamamoto
昌樹 山本
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Mitsubishi Chemical Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide spherical carbon particles that have a new structure different from the structure of the conventional carbon particles and have uniform shapes, have excellent dispersibility in a solvent, and is easy to handle. <P>SOLUTION: The aggregate of spherical carbon particles has a structure having a space part surrounded by a carbon crystal wall, and have a diameter ≥5 nm to ≤100 μm, in which the ratio of the spherical carbon particles having a radius ratio ranging from 1.0 to 1.3 is ≥40% in number. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は球状炭素粒子の集合体およびその製造方法に関する。また、本発明は球状炭素粒子の分散体に関する。   The present invention relates to an aggregate of spherical carbon particles and a method for producing the same. The present invention also relates to a dispersion of spherical carbon particles.

近年、炭素粒子の製造方法について次の様な種々の報告がある。   In recent years, there have been various reports on carbon particle production methods as follows.

（１）ＰＭＭＡ（ポリメタクリル酸メチル）／ＰＤＶＢ（ポリジビニルベンゼン）のＣｏｒｅ／Ｓｈｅｌｌ粒子を重合で作製し、炭化することで中空炭素粒子を作製する（非特許文献１）。 (1) Core / Shell particles of PMMA (polymethyl methacrylate) / PDVB (polydivinylbenzene) are produced by polymerization and carbonized to produce hollow carbon particles (Non-patent Document 1).

（２）Ｈａｒｄ Ｃｏｒｅ／Ｍｅｓｏｐｏｒｏｕｓ Ｓｈｅｌｌ構造のサブミクロンサイズのシリカ粒子を作製し、テンプレートとして使用し、フェノール樹脂かポリジビニルベンゼンをｉｎ−ｓｉｔｕ重合する。炭化した後、シリカテンプレートを除去する（テンプレート法１）（非特許文献２）。 (2) Submicron-sized silica particles having a Hard Core / Mesoporous Shell structure are prepared and used as a template, and a phenol resin or polydivinylbenzene is in-situ polymerized. After carbonization, the silica template is removed (Template Method 1) (Non-Patent Document 2).

（３）Ｃｏｌｌｏｉｄａｌ Ｓｉｌｉｃａの表面にポリマーのシェルを形成し、炭化後、中のシリカを溶解して中空炭素を作製する（テンプレート法２）（非特許文献３）。 (3) A polymer shell is formed on the surface of Colloidal Silica, and after carbonization, silica inside is dissolved to produce hollow carbon (template method 2) (Non-patent Document 3).

上記（１）の方法は、粒径は１５ｎｍ程度のものも作製可能であるが、得られる炭素粒子は、Ｘ線回折法（ＸＲＤ）のデータによると、２θが２４度であり、アモルファス状炭素である。また、上記（２）及び（３）の方法は、原料を型の形状に合わせる方法であり、更に、上記（２）の方法で得られる炭素粒子のシェルはメゾポーラス構造ある。そして、結晶に関する報告ないが、ポーラス構造が発達しているため、結晶構造は発達していないと考えられる。また、表面にメソポアを有したスポンジ状の構造体となっている。上記（３）の方法ではポリマーとして架橋剤であるジビニルベンゼンを使用しているため、得られる炭素粒子は結晶構造が発達し難いと考えられる。何故ならば、一般的には、ポリジビニルベンゼンは固相炭化反応を経て炭化されるため、結晶構造は発達し難いとされているからである。   Although the method (1) can produce a particle having a particle size of about 15 nm, the obtained carbon particles have an angle of 2θ of 24 degrees according to X-ray diffraction (XRD) data. It is. The methods (2) and (3) are methods for adjusting the raw material to the shape of the mold, and the shell of the carbon particles obtained by the method (2) has a mesoporous structure. And although there is no report about the crystal, it is considered that the crystal structure is not developed because the porous structure is developed. Moreover, it is a sponge-like structure having mesopores on the surface. In the method (3), divinylbenzene as a cross-linking agent is used as a polymer, so that the obtained carbon particles are considered to hardly develop a crystal structure. This is because, in general, polydivinylbenzene is carbonized through a solid-phase carbonization reaction, so that the crystal structure is hardly developed.

また、上記の他、「ナノポリヘドロン」と呼ばれる炭素粒子も報告されている（非特許文献４）。この炭素粒子は、数層から数十層のグラファイトが入れ子構造状に積み重なって、全体として多面体の形態をなしている。カーボンナノチューブが溶媒に分散させるのが難しいのと同様に、ナノポリヘドロンの均一分散体を得ることは難しく、手間も掛かりコストが高くなる。また、ナノポリヘドロンは、多面体となっているため、球形度が低く、形状の均一性も低い。   In addition to the above, carbon particles called “nanopolyhedron” have also been reported (Non-patent Document 4). The carbon particles have a polyhedral shape as a whole, in which several to several tens of layers of graphite are stacked in a nested structure. Just as it is difficult to disperse carbon nanotubes in a solvent, it is difficult to obtain a uniform dispersion of nanopolyhedron, which is laborious and expensive. Moreover, since nanopolyhedron is a polyhedron, it has low sphericity and low shape uniformity.

更には、径１００ｎｍ、長さ６０ミクロンのポアを有するアルミナメンブレンをテンプレートとして、このポアに加熱したメソフェーズピッチをｃａｐｉｌｌａｒｙ ｆｌｏｗで流し込み、炭化してからテンプレートを溶解除去して、繊維状の炭素粒子（カーボンナノファイバー）を得るという方法も報告されている（非特許文献５）。しかしながら、この方法では、アルミナメンブレンの形状が筒形状となることから、繊維状の炭素粒子を誘導することは可能であるが、真球または球形度が高い球状の炭素粒子を誘導することは不可能である。   Furthermore, using an alumina membrane having a pore of 100 nm in diameter and 60 microns in length as a template, heated mesophase pitch is poured into this pore with a capillary flow, carbonized, and then the template is dissolved and removed to form fibrous carbon particles ( A method of obtaining carbon nanofibers has also been reported (Non-patent Document 5). However, in this method, since the shape of the alumina membrane becomes a cylindrical shape, it is possible to induce fibrous carbon particles, but it is not possible to induce spherical carbon particles having a high sphericity or high sphericity. Is possible.

また、実質的に単一な球状形態を有し、粒度分布がシャープな炭素微小球およびその製造方法が報告されている（特許文献１）。しかしながら、この炭素微小球の構造は、報告された図面（電子顕微鏡写真）から、粒子内部に空間部を有していないと理解される。何故ならば、仮に空間部が存在していれば周辺と内部でコントラストが異なるからである。   In addition, carbon microspheres having a substantially single spherical shape and a sharp particle size distribution and a method for producing the same have been reported (Patent Document 1). However, it is understood from the reported drawing (electron micrograph) that the structure of the carbon microsphere does not have a space inside the particle. This is because if there is a space, the contrast is different between the periphery and the inside.

「Chem. Mater. , p2109-2111, Vol. 15, No.11,2003」"Chem. Mater., P2109-2111, Vol. 15, No. 11, 2003" 「Adv. Mater. p19-21, 2002, 14, No.1, January 4」"Adv. Mater. P19-21, 2002, 14, No.1, January 4" 「Adv. Mater. p1390-1393, 2002, 14, No.19, October 2」"Adv. Mater. P1390-1393, 2002, 14, No.19, October 2" 「フラーレンの化学と物理（２００２年３月１５日、財団法人名古屋大学出版会発行、第２３５頁）」“Fullerene Chemistry and Physics (March 15, 2002, published by Nagoya University Press, page 235)” 「Adv. Mater.p164-167 ,2003,15,No.2,January 16」"Adv. Mater.p164-167, 2003,15, No.2, January 16" 特開２００４−２１１０１２号公報JP 2004-211012 A

本発明の目的は、従来の炭素粒子とは異なる新規な構造を有し、各種用途に適用可能な球状炭素粒子およびその集合体ならびにその製造方法および球状炭素粒子の分散体を提供することにある。特に、本発明の目的は、形状が揃っており、かつ、溶媒への分散性が優れ、取り扱いが容易な球状炭素粒子とその集合体を提供することにある。   An object of the present invention is to provide spherical carbon particles having a novel structure different from that of conventional carbon particles, applicable to various uses, an aggregate thereof, a production method thereof, and a dispersion of spherical carbon particles. . In particular, an object of the present invention is to provide spherical carbon particles having a uniform shape, excellent dispersibility in a solvent, and easy to handle, and aggregates thereof.

なお、本発明において、「集合体」とは本発明の球状炭素粒子が複数個存在する状態をいい、分散媒体に高分散した状態および乾燥した状態の両方を含む概念である。一方、「分散体」とは上記の前者のみを示す概念である。   In the present invention, the “aggregate” means a state where a plurality of the spherical carbon particles of the present invention are present, and is a concept including both a highly dispersed state and a dried state in a dispersion medium. On the other hand, “dispersion” is a concept showing only the former.

本発明者らは、鋭意検討を重ねた結果、特定の炭素化手段の採用により、形状の揃った球状炭素粒子が得られ、更に、当該粒子は従来存在しなかった新規な構造を備えていることを知得し、本発明の完成に到った。   As a result of intensive studies, the present inventors have obtained spherical carbon particles having a uniform shape by adopting a specific carbonization means, and further, the particles have a novel structure that did not exist conventionally. This was learned and the present invention was completed.

すなわち、本発明の第１の要旨は、粒径が５ｎｍ以上１００μｍ以下の粒子であり炭素結晶の結晶壁で包囲された空間部を有する構造の球状炭素粒子の集合体であって、半径比が１．０〜１．３の範囲である球状炭素粒子の割合が４０個数％以上であることを特徴とする球状炭素粒子の集合体に存する。   That is, the first gist of the present invention is an aggregate of spherical carbon particles having a particle size of 5 nm or more and 100 μm or less and having a space part surrounded by a crystal wall of a carbon crystal, and having a radius ratio. It exists in the aggregate | assembly of the spherical carbon particle characterized by the ratio of the spherical carbon particle which is the range of 1.0-1.3 being 40 number% or more.

本発明の第２の要旨は、球状炭素粒子の集合体であって、以下の方法で調製された分散液について、調製後２４時間静置して測定した以下の式（Ｉ）で表される粒径分布指標が０．１〜２０であることを特徴とする球状炭素粒子の集合体に存する。   The second gist of the present invention is an aggregate of spherical carbon particles, and is expressed by the following formula (I) measured by allowing the dispersion prepared by the following method to stand for 24 hours after preparation. It exists in the aggregate | assembly of the spherical carbon particle characterized by the particle size distribution parameter | index being 0.1-20.

＜分散液の調製＞
内径１３ｍｍ、容量５ｍｌのガラス容器に分散媒３ｍｌと試料１ｍｇを採り、蓋を被せ、超音波振盪器を使用し、高周波出力１２０Ｗ、発振周波数３８ｋＨｚの条件下に１分間振とうさせて試料を分散させる。 <Preparation of dispersion>
Place 3 ml of dispersion medium and 1 mg of sample in a glass container with an inner diameter of 13 mm and a capacity of 5 ml, cover the sample, and use an ultrasonic shaker to shake the sample for 1 minute under conditions of high frequency output of 120 W and oscillation frequency of 38 kHz. Let

本発明の第３の要旨は、粒径が５ｎｍから１００μｍの範囲から選択される前駆体球状粒子を原料とし、当該原料をその形状を維持するように原形型で被覆した状態で炭素化することを特徴とする球状炭素粒子の製造方法に存する。   The third gist of the present invention is to carbonize a precursor spherical particle selected from a range of 5 nm to 100 μm in particle size and coat the raw material with an original mold so as to maintain the shape. In a method for producing spherical carbon particles.

本発明の第４の要旨は、分散媒中に第１の要旨に係る球状炭素粒子の集合体を分散して成ることを特徴とする球状炭素粒子の分散体に存する。   The fourth gist of the present invention resides in a dispersion of spherical carbon particles, characterized in that the aggregate of spherical carbon particles according to the first gist is dispersed in a dispersion medium.

本発明の第５の要旨は、分散媒中に第２の要旨に係る球状炭素粒子の集合体を分散して成ることを特徴とする球状炭素粒子の分散体に存する。   The fifth gist of the present invention resides in a dispersion of spherical carbon particles, wherein the spherical carbon particle aggregate according to the second gist is dispersed in a dispersion medium.

本発明によれば、粒径が５ｎｍ以上１００μｍ以下であり炭素結晶壁で包囲された空間部を有する球状炭素粒子が提供される。本発明の球状炭素粒子は特定の炭素化手法を使用した製造方法（本発明の製造方法）によって容易に製造できる。また、本発明の球状炭素粒子は、分散媒中で凝集なく均一に分散することが出来、その結果、導電性、電界放出などの電気的特性を均質に発現させることが出来る。この他、ＤＤＳ（ドラッグデリバリーシステム）としての応用や潤滑剤としての応用も期待される。   According to the present invention, spherical carbon particles having a particle size of 5 nm or more and 100 μm or less and having a space part surrounded by a carbon crystal wall are provided. The spherical carbon particles of the present invention can be easily manufactured by a manufacturing method using a specific carbonization technique (the manufacturing method of the present invention). Further, the spherical carbon particles of the present invention can be uniformly dispersed in the dispersion medium without aggregation, and as a result, electrical characteristics such as conductivity and field emission can be expressed uniformly. In addition, application as a DDS (drug delivery system) and application as a lubricant are also expected.

以下、本発明を詳細に説明するが、この発明は、以下の実施の形態に限定されるものではなく、本発明の要旨の範囲内であれば、種々に変更して実施することが出来る。   Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.

先ず、説明の便宜上、本発明に係る球状炭素粒子の製造方法について説明する。   First, for the convenience of explanation, a method for producing spherical carbon particles according to the present invention will be described.

本発明においては、原料として球状の含炭素粒子（前駆体球状粒子）を使用する。前駆体球状粒子の粒径は５ｎｍから１００μmの範囲から選択される。原料の前駆体球状粒子の粒径および形状は、それを確認可能な倍率、例えば、粒径が数百ｎｍの場合、倍率５万倍以上のＴＥＭ（透過型電子顕微鏡）の観察像で確認できるが、簡便的にはＳＥＭ（走査型電子顕微鏡）を使用してもよい。この点は、後述の本発明の球状炭素粒子粒径および形状についても同様である。   In the present invention, spherical carbon-containing particles (precursor spherical particles) are used as a raw material. The particle diameter of the precursor spherical particles is selected from the range of 5 nm to 100 μm. The particle size and shape of the precursor precursor spherical particles can be confirmed by an observation image of a TEM (transmission electron microscope) having a magnification of 50,000 times or more when the particle size is several hundred nm. However, for convenience, an SEM (scanning electron microscope) may be used. This also applies to the spherical carbon particle diameter and shape of the present invention described later.

上記の前駆体球状粒子の材料（前駆体物質）としては、耐熱性材料で被覆して炭素化可能な材料であれば特に制限されないが、液相炭素化が可能な材料または易熱分解ポリマー含有物質が好ましい。   The material for the precursor spherical particles (precursor substance) is not particularly limited as long as it is a material that can be carbonized by coating with a heat-resistant material. Substances are preferred.

なお、液相炭素化とは、固体がガラス転移温度Ｔｇにおける流動状態よりも高い流動状態を経て、熱化学反応が液相中で進行し、分子の移動や配向が比較的起こり易い炭素化過程をいう。従って、液相炭素化が可能な材料とは後述する本発明の炭素化条件下の加熱過程を経た場合に塑性変形が可能な材料を指し、一般的な不活性ガス下での炭素化条件での加熱過程での炭素化とは必ずしも一致するものではない。   Liquid phase carbonization is a carbonization process in which a solid undergoes a fluid state higher than the fluid state at the glass transition temperature Tg, a thermochemical reaction proceeds in the liquid phase, and molecular movement and orientation are relatively likely to occur. Say. Therefore, the material capable of liquid phase carbonization refers to a material that can be plastically deformed through a heating process under the carbonization conditions of the present invention described later, and is a carbonization condition under a general inert gas. This does not necessarily coincide with carbonization in the heating process.

液相炭素化が可能な材料としては、具体的には、ピッチ、ポリアクリロニトリル又はその共重合ポリマー、ポリビニルアルコール、ポリビニルクロライド、フェノール樹脂、レーヨン等が挙げられ、これらのうち、ポリアクリロニトリル又はその共重合ポリマーが好ましい。   Specific examples of materials that can be liquid phase carbonized include pitch, polyacrylonitrile or a copolymer thereof, polyvinyl alcohol, polyvinyl chloride, phenol resin, rayon, and the like. Of these, polyacrylonitrile or a copolymer thereof. Polymerized polymers are preferred.

易熱分解性ポリマーは、通常、不活性な雰囲気下で、常圧で、５００℃以上に加熱した際に分解するポリマーのことをいう。具体的には、ポリスチレン、ポリアクリル酸メチル、ポリメタクリル酸メチル、ポリエチレン、ポリプロピレン等が挙げられ、これらのうち、ポリスチレン、ポリメタクリル酸メチルが好ましい。これらのポリマーは、通常、炭素粒子の製造原料として使用されていないが、本発明の製造方法では、耐熱性材料で被覆して炭素化するため、予想に反して、炭素粒子化できるものと考えられる。   The readily heat decomposable polymer usually refers to a polymer that decomposes when heated to 500 ° C. or higher under an inert atmosphere at normal pressure. Specific examples include polystyrene, polymethyl acrylate, polymethyl methacrylate, polyethylene, polypropylene, and the like. Among these, polystyrene and polymethyl methacrylate are preferable. These polymers are not usually used as a raw material for producing carbon particles. However, in the production method of the present invention, carbonization is performed by coating with a heat-resistant material. It is done.

上記の材料を使用した前駆体球状粒子の作製方法としては以下の方法が例示できる。アクリロニトリル等の液相可能材料のポリマー群の中のモノマーを原料とし、必要に応じて共重合可能なモノマーを併用した乳化重合、懸濁重合およびソープフリー重合などにより、均一な粒径をもつポリアクリロニトリル及びその共重合ポリマーの粒子をエマルジョンとして得る方法が挙げられる。ここでの共重合可能なモノマーは易熱分解性ポリマー群の中から選ばれるモノマーであってもよい。また、粒径が極めて均一な前駆体球状粒子の別の作製方法としては、ソープフリー重合で得た易熱分解性ポリマー粒子に更にアクリロニトリル等の液相可能材料のポリマー群の中のモノマーを加え、２段階のソープフリー重合を行うことにより、コアシェル構造の均一な粒子をエマルジョンとして得る方法が挙げられる。これらの重合方法により得られるエマルジョン中の前駆体粒子は、通常５ｎｍから１００μｍの範囲の粒径を有し、極めて粒径分布の小さい粒子の集合体として得られる。   The following methods can be exemplified as methods for producing precursor spherical particles using the above materials. Polypropylene having a uniform particle size by emulsion polymerization, suspension polymerization, and soap-free polymerization using monomers in the polymer group of liquid phase materials such as acrylonitrile as a raw material, and using monomers that can be copolymerized as necessary. The method of obtaining the particle | grains of acrylonitrile and its copolymer polymer as an emulsion is mentioned. The monomer that can be copolymerized here may be a monomer selected from the group of thermally decomposable polymers. Another method for producing precursor spherical particles having a very uniform particle size is to add monomers in a polymer group of liquid phase-capable materials such as acrylonitrile to the readily thermally decomposable polymer particles obtained by soap-free polymerization. A method of obtaining uniform particles of a core-shell structure as an emulsion by carrying out two-stage soap-free polymerization is mentioned. Precursor particles in the emulsion obtained by these polymerization methods usually have a particle size in the range of 5 nm to 100 μm, and are obtained as an aggregate of particles having a very small particle size distribution.

前駆体球状粒子は、液相炭素化が可能な材料と易熱分解ポリマーの何れか一方のみを含んでいても構わないが、両方を含んでいるのが好ましい。また、本発明の炭素粒子の優れた性能を大幅に妨げなければ、液相炭素化が可能な材料または易熱分解ポリマー以外の物質を含んでいてもよい。   The precursor spherical particles may contain only one of a material capable of liquid phase carbonization and an easily pyrolyzable polymer, but preferably contain both. Moreover, as long as the outstanding performance of the carbon particles of the present invention is not significantly hindered, a material other than a material capable of liquid phase carbonization or an easily pyrolyzed polymer may be included.

前駆体球状粒子が、液相炭素化が可能な材料と易熱分解ポリマーの両方を含んでいる場合、易熱分解性ポリマーは、前駆体球状粒子を炭素化させる加熱過程での液相炭素化可能材料の塑性変形を容易にし、更に、高温域では熱分解してガスとなり、その圧力によって前駆体球状粒子を内部から拡張し、中空粒子の形成を促進する機能を有すると推定される。そして、ガス圧によって拡張された前駆体球状粒子は、粒子の外表面に塗布された後述の耐熱性材料の壁に押しつけられ、その場で炭素化が進行し且つ結晶化が促進されると考えられる。   When the precursor spherical particles contain both a liquid phase carbonizable material and an easily pyrolyzed polymer, the easily pyrolyzable polymer is liquid phase carbonized during the heating process that carbonizes the precursor spherical particles. It is presumed that it has the function of facilitating the plastic deformation of the possible material, and further thermally decomposing into a gas at a high temperature range and expanding the precursor spherical particles from the inside by the pressure to promote the formation of hollow particles. The precursor spherical particles expanded by the gas pressure are pressed against the wall of the heat-resistant material described later applied to the outer surface of the particles, and carbonization proceeds and crystallization is promoted on the spot. It is done.

前駆体球状粒子に易熱分解性ポリマーを含有させる方法としては、それぞれの構成モノマーを任意の組成比で共重合する方法や組成を偏在させるためのシード重合方法などが挙げられる。   Examples of the method of containing the easily decomposable polymer in the precursor spherical particles include a method of copolymerizing each constituent monomer at an arbitrary composition ratio and a seed polymerization method for unevenly distributing the composition.

本発明の製造方法は、上記の前駆体粒子を原料とし、当該原料をその形状を維持するように原形型で被覆した状態で炭素化することを特徴とする。そして、本発明の好ましい態様においては、耐熱性材料で原料を被覆することにより、当該原料の原形型と略同一の形状と粒径を有する球状炭素粒子が形成される。   The production method of the present invention is characterized in that the precursor particles described above are used as raw materials, and the raw materials are carbonized in a state where they are covered with an original mold so as to maintain their shapes. In a preferred embodiment of the present invention, spherical carbon particles having substantially the same shape and particle size as the original mold of the raw material are formed by coating the raw material with a heat resistant material.

上記の耐熱性材料は、前駆体粒子が炭素化する温度域以下の温度で、自身の熱変形などにより前駆体粒子の形状に影響を与えない必要がある。好適な耐熱性材料としては、５０〜５００℃の温度域における線熱収縮率が３０％以下である材料がよく、１００〜５００℃の範囲で明確なガラス転移点（Tｇ）を持たない材料が好ましい。また、加熱による炭素化後に簡便な方法で除去できる材料が好ましい。   The above heat-resistant material should not affect the shape of the precursor particles due to its own thermal deformation at a temperature below the temperature range where the precursor particles are carbonized. As a suitable heat-resistant material, a material having a linear heat shrinkage rate of 30% or less in a temperature range of 50 to 500 ° C. is preferable, and a material having no clear glass transition point (Tg) in the range of 100 to 500 ° C. preferable. A material that can be removed by a simple method after carbonization by heating is preferred.

上記の特性を満たす耐熱性材料としては、一般的に無機酸化物が好ましい。具体的には、ＳｉＯ２、Ａｌ２Ｏ３、ＴｉＯ２、ＺｒＯ２、Ｉｎ２Ｏ、ＺｎＯ、ＰｂＯ、Ｙ２Ｏ３、ＢａＯ、これらの混合物などが挙げられる。これらの中では、本発明の球状炭素粒子の純度および金属不純物の制御の観点から、ＳｉＯ２、Ａｌ２Ｏ３、ＴｉＯ２、ＺｒＯ２が好ましく、前駆体粒子の炭素化反応と結晶化を安定に進行させる観点から、ＳｉＯ２が更に好ましい。 As a heat-resistant material satisfying the above characteristics, an inorganic oxide is generally preferable. Specific examples include SiO 2 , Al 2 O 3 , TiO 2 , ZrO 2 , In 2 O, ZnO, PbO, Y 2 O 3 , BaO, and mixtures thereof. Among these, SiO 2 , Al 2 O 3 , TiO 2 , and ZrO 2 are preferable from the viewpoint of the purity of the spherical carbon particles of the present invention and the control of metal impurities, and the carbonization reaction and crystallization of the precursor particles are stable. From the viewpoint of proceeding to the above, SiO 2 is more preferable.

前駆体粒子の被覆方法としては、上記の無機酸化物の金属アルコキシド等を原料としたゾルゲル法による被覆方法、硝酸塩またはオキシ塩化物塩などの溶媒可溶性の無機化合物の溶液による被覆方法などが挙げられる。   Examples of the method for coating precursor particles include a coating method by a sol-gel method using a metal alkoxide of the above inorganic oxide as a raw material, a coating method by a solution of a solvent-soluble inorganic compound such as nitrate or oxychloride salt, and the like. .

更には、シリカゾルを前駆体のポリマー粒子にアルコール等の溶媒中で混合した後に乾燥させ、前駆体粒子表面に付着させる方法が挙げられる。また、上記と同様なゾルゲル法による被覆方法において、金属アルコキシド以外で上記の特性を満たす材料としては珪酸ソーダ（水ガラス）が挙げられる。   Further, there is a method in which silica sol is mixed with precursor polymer particles in a solvent such as alcohol and then dried to adhere to the surface of the precursor particles. Moreover, in the coating method by the sol-gel method similar to the above, sodium silicate (water glass) is mentioned as a material satisfying the above characteristics other than the metal alkoxide.

特に、金属アルコキシドの加水分解により得たゾル溶液を前駆体粒子に塗布する方法、または、当該加水分解液中に前駆体粒子を分散させた後に乾燥させて前駆体粒子の周囲をゲル化もしくは固化する方法は、ゲルの均一化工程を安定制御する上で好ましい。   In particular, a method in which a sol solution obtained by hydrolysis of a metal alkoxide is applied to precursor particles, or the precursor particles are dispersed in the hydrolysis liquid and then dried to gel or solidify the periphery of the precursor particles. This method is preferable for stably controlling the gel homogenization step.

ＳｉＯ２を被覆する具体的方法としては次の方法が例示できる。すなわち、先ず、メタノール、エタノール等のアルコール類の溶液にアルコキシシラン類を加えた後、水を加え、室温で数時間撹拌することにより加水分解させ、シリケートゾル溶液を調製する。このゾル溶液調製の際に、ゾルの安定性と反応性を制御する上で適当なｐＨに調節するのが一般的であり、ここで、シュウ酸、酢酸、塩酸、硫酸、アンモニア等を触媒として加えてもよい。 The following method can be illustrated as a specific method for coating SiO 2 . That is, first, after adding alkoxysilanes to a solution of alcohols such as methanol and ethanol, water is added and the mixture is stirred at room temperature for several hours to be hydrolyzed to prepare a silicate sol solution. In preparing this sol solution, it is common to adjust the pH to an appropriate pH to control the stability and reactivity of the sol, where oxalic acid, acetic acid, hydrochloric acid, sulfuric acid, ammonia, etc. are used as catalysts. May be added.

珪酸ソーダを使用する場合は、上述の金属アルコキシドからゾルを作製する方法の他に、珪酸ソーダのアルコール液に水を加え、イオン交換樹脂と攪拌することでナトリウムと水素の交換反応を行い、ゾル溶液を調製する方法がある。   In the case of using sodium silicate, in addition to the above-described method for producing a sol from the metal alkoxide, water is added to the alcohol solution of sodium silicate, and the reaction is exchanged between sodium and hydrogen by stirring with an ion exchange resin. There are methods for preparing solutions.

更に、ゾル溶液に前駆体粒子を混合し、通常、室温から１００℃の範囲、好ましくは、室温から８０℃の範囲で、数時間から数日静置してゲル化に至らせ、前駆体粒子を分散させたシリカゲルを得る方法が挙げられる。また、斯かる方法の他、前駆体粒子にシリケートゾル溶液をスプレー塗布する方法なども挙げられる。   Further, the precursor particles are mixed with the sol solution, and are usually left in the range of room temperature to 100 ° C., preferably in the range of room temperature to 80 ° C. for several hours to several days to cause gelation. And a method of obtaining silica gel in which is dispersed. In addition to such a method, a method of spray-coating a silicate sol solution onto the precursor particles may be used.

上述のアルコキシシラン類の具体例としては、テトラアルコキシシラン類であるテトラメトキシシラン、テトラエトキシシラン、テトライソプロポキシシラン、テトラブトキシシラン、これらそれぞれのオリゴマーの他、アルキルトリアルコキシシラン類であるメチルトリメトキシシラン、メチルトリエトキシシラン、エチルトリメトキシシラン、エチルトリエトキシシラン等が例示できる。ゲル化のプロセス条件および被覆時の前駆体粒子の分散性などに応じ、２種類以上のアルコキシシラン類を併用してもよい。   Specific examples of the above alkoxysilanes include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, their respective oligomers, and alkyltrialkoxysilanes such as methyltrialkoxysilanes. Examples include methoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane. Two or more types of alkoxysilanes may be used in combination depending on the gelation process conditions and the dispersibility of the precursor particles during coating.

上記のＳｉＯ２被覆において、ＳｉＯ２被覆された前駆体粒子を真空乾燥、または、熱変形しない範囲で加熱することにより、ＳｉＯ２中のシロキサン結合の密度を高めることは、被覆成分の耐熱性を高める上で有効である。 In the above-mentioned SiO 2 coating, by increasing the density of siloxane bonds in SiO 2 by heating the SiO 2 -coated precursor particles in a range that is vacuum-dried or not thermally deformed, the heat resistance of the coating component is increased. It is effective in raising.

本発明の炭素粒子は、ポリマー組成やシリケートゾルのゲル化条件の違いによって、図１（ａ）〜（ｃ）に示す様な炭素結晶の方向が異なる炭素粒子および複数の空間部が存在する炭素粒子を作り分けることが出来る。以下、各構造の炭素粒子の製造方法について説明する。なお、図１（ａ）〜（ｃ）中の符号（１）は炭素結晶壁、（２）は空間部、（３）は炭素結晶の方向（炭素網面の積層方向）を表す。   The carbon particles of the present invention include carbon particles having different directions of carbon crystals as shown in FIGS. 1 (a) to 1 (c) and carbon having a plurality of space portions depending on differences in the polymer composition and gelation conditions of the silicate sol. Particles can be made separately. Hereinafter, the manufacturing method of the carbon particle of each structure is demonstrated. In addition, the code | symbol (1) in FIG. 1 (a)-(c) represents a carbon crystal wall, (2) represents a space part, (3) represents the direction (lamination direction of a carbon network surface) of a carbon crystal.

＜図１（ａ）に示す構造の炭素粒子の製造法＞
この炭素粒子の特徴は、結晶が接線と略平行な方向に積層し、結果として、炭素結晶端が外周に露出した構造を備えるか、または、炭素網面のループ状構造を外周に持つ形状を示す点にある。この炭素粒子の製造法の一例は次の通りである。 <Method for producing carbon particles having the structure shown in FIG. 1 (a)>
This carbon particle is characterized by having a structure in which crystals are stacked in a direction substantially parallel to a tangent and, as a result, the end of the carbon crystal is exposed on the outer periphery, or a shape having a loop structure of a carbon network surface on the outer periphery. There is in point to show. An example of a method for producing the carbon particles is as follows.

上述したゾル溶液に前駆体粒子を混合し、通常、開放系で１００℃以下の条件で乾燥してゲル化に至らせ、前駆体粒子を分散させたシリカゲルを得る。乾燥する時間は、通常は数分以上、好ましくは３０分間以上、また、通常は数時間以下、好ましくは６０分以下の範囲とする。この時間があまり長過ぎると、炭素粒子表面の結晶端の向きが制御しにくい傾向がある。この様なプロセスを経て作製した前駆体粒子分散シリカゲルは、ポリマーの分解によって発生するガスを適度に逃がすのに好適なサイズの細孔を有することになり、更に、残存した水酸基が多数存在するため、ポリマーの熱分解によって形成された炭素前駆体が直接接するシリカ表面は親水性を示すことになり、このため、ポリマーが熱分解して形成される炭素前駆体はそのエッジをシリカ表面に向けて配向し易くなり、結果として炭素結晶端が外周に露出した構造を備えるか、または、炭素網面のループ状構造を外周に持つ形状を示すことになると推定される。   Precursor particles are mixed in the sol solution described above, and are usually dried in an open system at a temperature of 100 ° C. or lower to cause gelation, thereby obtaining silica gel in which the precursor particles are dispersed. The drying time is usually several minutes or longer, preferably 30 minutes or longer, and usually several hours or shorter, preferably 60 minutes or shorter. If this time is too long, the orientation of the crystal edges on the surface of the carbon particles tends to be difficult to control. Precursor particle-dispersed silica gel produced through such a process has pores of a size suitable for appropriately releasing the gas generated by the decomposition of the polymer, and there are many remaining hydroxyl groups. The silica surface that is directly in contact with the carbon precursor formed by thermal decomposition of the polymer exhibits hydrophilicity. For this reason, the carbon precursor formed by thermal decomposition of the polymer has its edge directed toward the silica surface. It is presumed that it becomes easy to be oriented, and as a result, it has a structure in which the end of the carbon crystal is exposed to the outer periphery or a shape having a loop structure of a carbon network surface on the outer periphery.

＜図１（ｂ）に示す構造の炭素粒子の製造法＞
この炭素粒子の特徴は、結晶が半径方向に積層し、炭素結晶端が外周に露出した構造や炭素網面のループ構造が外周に存在しない点にある。この炭素粒子の製造法の一例は次の通りである。 <Method for producing carbon particles having the structure shown in FIG. 1B>
This carbon particle is characterized in that crystals are stacked in the radial direction and the end of the carbon crystal is exposed to the outer periphery or the loop structure of the carbon network surface does not exist on the outer periphery. An example of a method for producing the carbon particles is as follows.

炭素化過程での被覆している原形型の表面の残官能基の結晶配向への影響を減じることから、長時間の反応によりゲル化に至らせる方法が有効である。この場合、例えば、シリケート由来のシリカゾルの乾燥条件は通常、密閉系で２４時間以上、好ましくは４８時間以上とする。また、炭素結晶の配向の制御を目的として、炭素化過程の前に、被覆した前駆体粒子を不融化処理をすることも可能である。すなわち、炭素結晶が表面にエッジを向けたあるいはループ構造を表面にもつ構造を避け、結晶が半径方向に積層した構造を得る目的では不融化処理を行うことが有効である。ここで、不融化とは、炭素化前に分子間架橋反応などの重合反応を進めることにより流動粘度を高めることをいう。不融化処理の一般的な条件としては、空気または酸素雰囲気下、常圧で１５０℃以上２８０℃以下の範囲で１時間以上７２時間以内、好ましくは前記雰囲気下で１８０℃以上２４０℃以下の範囲で１時間以上２４時間以内で加熱する条件が例示できる。不融化処理をすることにより、前駆体粒子の液相炭化時の流動粘度を高めて被覆材料の表面構造からの影響を小さくすることが出来、結果的に結晶が半径方向に積層した構造の炭素結晶が得られると考えられる。   In order to reduce the influence on the crystal orientation of the residual functional group on the surface of the original mold to be coated in the carbonization process, a method of causing gelation by a long-time reaction is effective. In this case, for example, the drying condition of the silica sol derived from silicate is usually 24 hours or more, preferably 48 hours or more in a closed system. In addition, for the purpose of controlling the orientation of carbon crystals, it is possible to infusibilize the coated precursor particles before the carbonization process. That is, it is effective to perform the infusibilization treatment in order to obtain a structure in which the crystal is laminated in the radial direction while avoiding the structure in which the carbon crystal has an edge or the loop structure on the surface. Here, infusibilization refers to increasing the fluid viscosity by advancing a polymerization reaction such as an intermolecular crosslinking reaction before carbonization. As general conditions for the infusibilization treatment, in an air or oxygen atmosphere, a range of 150 ° C. or more and 280 ° C. or less at normal pressure is 1 hour or more and 72 hours or less, preferably a range of 180 ° C. or more and 240 ° C. or less in the atmosphere. Examples of the heating conditions are 1 hour or more and 24 hours or less. By performing infusibilization treatment, it is possible to increase the flow viscosity during liquid phase carbonization of the precursor particles and reduce the influence from the surface structure of the coating material. As a result, carbon with a structure in which crystals are laminated in the radial direction It is thought that crystals are obtained.

＜図１（ｃ）に示す構造の炭素粒子の製造法＞
この炭素粒子の特徴は、炭素結晶壁で包囲された空間部を有する球状炭素粒子において、炭素結晶壁の一部が欠落し、形態に関して内部空間部が外部と導通している点にある。この炭素粒子の製造法の一例は次の通りである。 <Method for producing carbon particles having the structure shown in FIG. 1 (c)>
This carbon particle is characterized in that, in a spherical carbon particle having a space part surrounded by a carbon crystal wall, a part of the carbon crystal wall is missing and the internal space part is electrically connected to the outside in terms of form. An example of a method for producing the carbon particles is as follows.

上記の図１（ｂ）に示す構造の炭素粒子の製造法において、不融化を施し、液相炭化時の流動粘度を一層高める。具体的には、不融化処理の条件を適宜変更する。例えば、上記の温度、時間、雰囲気の酸素濃度などを高めたり長くしたりする。または、前駆体粒子の材料として、分子間架橋し易い成分（例えばアクリロニトリル）の組成を高める。斯かる条件により、図１（ｃ）に示す構造の炭素粒子が得られる理由は次の様に考えられる。すなわち、前述に記載の推定メカニズムにおける分解ガスに関して個々の気泡が融合することを制御し、炭素化の過程で一つの粒子内で大きな一つの気泡となって拡張するよりも、小さな単位で複数の気泡として存在し、比較的小さな中空または空間として存在するものと推定される。このとき、前駆体粒子の表面近傍に生じた気泡は、炭素化後にシリカと形成する界面に空間部となる。従って、流動粘度を高めることにより、外部と導通する貫通部を有する空間部が形成され易くなる。   In the method for producing carbon particles having the structure shown in FIG. 1B, infusibilization is performed to further increase the fluid viscosity during liquid phase carbonization. Specifically, the conditions for the infusibilization process are changed as appropriate. For example, the temperature, time, and oxygen concentration in the atmosphere are increased or lengthened. Alternatively, the composition of a component (for example, acrylonitrile) that is easily intermolecularly crosslinked as a material for the precursor particles is increased. The reason why carbon particles having the structure shown in FIG. 1 (c) can be obtained under such conditions is considered as follows. That is, it controls the integration of individual bubbles with respect to the cracked gas in the estimation mechanism described above, and expands into a single large bubble within one particle in the process of carbonization, and expands a plurality of small units. It is presumed that it exists as bubbles and exists as a relatively small hollow or space. At this time, bubbles generated in the vicinity of the surface of the precursor particles become a space portion at the interface formed with silica after carbonization. Therefore, by increasing the flow viscosity, a space portion having a penetrating portion that is electrically connected to the outside is easily formed.

次に、前駆体粒子の炭素化について説明する。前駆体粒子の炭素化は、上述の原形型で表面が被覆された前駆体粒子を、窒素、アルゴン等の加熱時に当該前駆体粒子と反応する物質が存在しない雰囲気下で、加熱して行なう。加熱時の雰囲気は、フロー系でも、密閉系でも構わないが、フロー系の方が好ましい。加熱時の圧力は、加圧下でも減圧下でも構わないが、通常、常圧下で行なう。常圧下の場合の加熱温度は、通常５００℃以上、好ましくは８００℃以上である。加熱は、継続的に所定温度まで上げていっても、段階的に所定温度にまで上げていっても構わない。加熱時間は、加熱温度などにより異なるが、所定の加熱温度に到達した後、通常０．５〜２時間である。   Next, carbonization of the precursor particles will be described. The carbonization of the precursor particles is performed by heating the precursor particles whose surfaces are coated with the above-described original mold in an atmosphere where there is no substance that reacts with the precursor particles when heated, such as nitrogen or argon. The atmosphere during heating may be a flow system or a closed system, but the flow system is preferred. The pressure during heating may be under pressure or under reduced pressure, but is usually carried out under normal pressure. The heating temperature under normal pressure is usually 500 ° C. or higher, preferably 800 ° C. or higher. The heating may be continuously raised to a predetermined temperature or may be gradually raised to a predetermined temperature. The heating time varies depending on the heating temperature and the like, but is usually 0.5 to 2 hours after reaching the predetermined heating temperature.

炭素化後、通常、表面の原形型を除去する。除去方法としては、水酸化ナトリウム等のアルカリ水溶液やフッ酸で溶解する方法などが挙げられる。このうち、工業的に安全なことから、アルカリ水溶液で溶解する方法が好ましい。溶解除去は、通常、耐圧密閉容器中で１５０℃に加熱して溶解し、残った球状炭素粒子を固液分離して回収する等の方法で行う。前駆体にポリアクリロニトリル又はポリアクリロニトリルを含む共重合体を使用する場合、上記の方法で得られる球状炭素粒子の収率は、通常３０重量％以上、多くの場合３５〜４５重量％の範囲である。   After carbonization, the original surface mold is usually removed. Examples of the removing method include a method of dissolving with an aqueous alkali solution such as sodium hydroxide or hydrofluoric acid. Among these, the method of dissolving with an alkaline aqueous solution is preferable because it is industrially safe. The dissolution and removal are usually performed by a method such as heating to 150 ° C. in a pressure-resistant sealed container to dissolve, and separating and recovering the remaining spherical carbon particles by solid-liquid separation. When polyacrylonitrile or a copolymer containing polyacrylonitrile is used as a precursor, the yield of spherical carbon particles obtained by the above method is usually 30% by weight or more, and often in the range of 35 to 45% by weight. .

本発明の製造方法によれば、球状炭素粒子を均一な形状の粒子群として得ることが出来、更に、最終生成物の球状炭素粒子を前駆体の段階で設計することが出来る利点がある。すなわち、本発明の製造方法によれば、粒径５ｎｍから１００μmの前駆体球状粒子から実質的に同一粒径の球状炭素粒子（粒径５ｎｍから１００μm）を得ることが出来る。   According to the production method of the present invention, spherical carbon particles can be obtained as a group of particles having a uniform shape, and further, there is an advantage that the spherical carbon particles of the final product can be designed at the precursor stage. That is, according to the production method of the present invention, spherical carbon particles having a substantially same particle diameter (particle diameter of 5 nm to 100 μm) can be obtained from precursor spherical particles having a particle diameter of 5 nm to 100 μm.

また、本発明の製造方法は、結晶性の高い炭素粒子を得る上でも有効な方法である。すなわち、特に、前駆体物質が液相炭素化が可能な材料である場合、本発明の方法における炭素化過程の液相過程の生成物が炭素化後の生成物の結晶構造を大きく支配するが、表面を被覆している原形型の表面特性が結晶性に与える影響が大きい。ポリアクリロニトリル等の液相炭素化が可能なポリマーを前駆体とする場合、炭素化過程で生じる炭素ラジカルに及ぼす原形型の表面官能基の効果として、結晶化度と配向に対する大きな影響が挙げられる。なお、表面官能基としては、例えば、シラノール基、水酸基、ケトン基、エステル基などが挙げられる。   The production method of the present invention is also an effective method for obtaining carbon particles having high crystallinity. That is, in particular, when the precursor material is a material capable of liquid phase carbonization, the product of the liquid phase process of the carbonization process in the method of the present invention largely controls the crystal structure of the product after carbonization. The surface properties of the original mold covering the surface have a great influence on the crystallinity. When a polymer capable of liquid phase carbonization such as polyacrylonitrile is used as a precursor, the effect of the original surface functional group on the carbon radical generated in the carbonization process has a great influence on the crystallinity and orientation. Examples of the surface functional group include a silanol group, a hydroxyl group, a ketone group, and an ester group.

本発明の製造方法における上述の作用効果により、本発明の製造方法で得られる球状炭素粒子は、後述する様に、従来存在しなかった新規な構造を有している。   Due to the above-described effects in the production method of the present invention, the spherical carbon particles obtained by the production method of the present invention have a novel structure that did not exist conventionally, as will be described later.

次に、本発明の球状炭素粒子について説明する。   Next, the spherical carbon particles of the present invention will be described.

本発明の球状炭素粒子は、粒径が５ｎｍから１００μmの範囲である。粒径は、アスペクト比が１の場合はその直径を指し、アスペクト比が１を超える場合はその長径を指す。球状とは、通常、アスペクト比が２未満のものをいう。   The spherical carbon particles of the present invention have a particle size in the range of 5 nm to 100 μm. The particle diameter indicates the diameter when the aspect ratio is 1, and indicates the major diameter when the aspect ratio exceeds 1. The term “spherical” generally means that the aspect ratio is less than 2.

本発明の球状炭素粒子は、半径比が一定の範囲内に収まっていることが好ましい。半径比が１．３よりも大きい場合は、スラリーとして使用する場合の流動粘度が高くなり、例えばインクジェット顔料として使用した場合に吐出に必要な圧力が高くなり過ぎる等の問題が生じ易い。   The spherical carbon particles of the present invention preferably have a radius ratio within a certain range. When the radius ratio is larger than 1.3, the flow viscosity when used as a slurry is increased, and for example, when used as an inkjet pigment, problems such as excessively high pressure required for ejection tend to occur.

本発明の球状炭素粒子の炭素含有率は、必ずしも１００重量％である必要はないが、化学的な安定性の観点から、元素分析値による値として、通常７０重量％以上、好ましくは７５重量％以上である。   The carbon content of the spherical carbon particles of the present invention is not necessarily 100% by weight, but from the viewpoint of chemical stability, it is usually 70% by weight or more, preferably 75% by weight as a value based on elemental analysis values. That's it.

通常、本発明の球状炭素粒子は結晶性である。ここでいう結晶性は、必ずしも、いわゆる黒鉛状に制御されたものである必要はなく、小山ら（「工業材料」第３０巻、第７号、ｐ１０９〜１１５）に示される様な乱層黒鉛であってもよい。結晶性の目安としてのＸ線回折の反射ピークから求める結晶学的特性は、次の様に示される。すなわち、出力源がＣｕＫαであるＸ線の回折角度２θが２５°以上（好ましくは２５．５°以上）にピークを示し、半値幅が７．０°以下（好ましくは６．５以下、更に好ましくは５．０°以下）である。そして、（００２）ピークの回折角からＢｒａｇｇの式で算出される炭素網目平均面間距離ｄ(002)は３．６Å以下（好ましくは３．４９Å以下）である。 Usually, the spherical carbon particles of the present invention are crystalline. The crystallinity here does not necessarily have to be controlled to a so-called graphite-like shape, and the multilayered graphite as shown in Koyama et al. ("Industrial Materials" Vol. 30, No. 7, p109-115). It may be. The crystallographic characteristics obtained from the reflection peak of X-ray diffraction as a measure of crystallinity are shown as follows. That is, when the output source is CuKα, the X-ray diffraction angle 2θ has a peak at 25 ° or more (preferably 25.5 ° or more), and the half-value width is 7.0 ° or less (preferably 6.5 or less, more preferably Is 5.0 ° or less). The carbon network average inter-plane distance d (002) calculated from the diffraction angle of the (002) peak by the Bragg equation is 3.6 mm or less (preferably 3.49 mm or less).

本発明の球状炭素粒子は、炭素結晶壁で包囲された空間部を有することを特徴とする。結晶は少なくとも粒子表面近傍または空間部に近い壁部に観察される。結晶の積層方向は倍率８０万倍以上でのTEM観察にて電子像のコントラストによって判別できる。   The spherical carbon particles of the present invention are characterized by having a space part surrounded by a carbon crystal wall. Crystals are observed at least in the vicinity of the particle surface or in the wall near the space. The crystal stacking direction can be discriminated by the contrast of the electron image by TEM observation at a magnification of 800,000 times or more.

本発明において、「炭素結晶壁で包囲されている」とは、狭義には、中空部に通じる一定以上の径の空孔を有していないことを指す。具体的には、ＴＥＭ写真によって観察した場合に、その孔径が通常数十ｎｍ以上、好ましくは数ｎｍ以上、更に好ましくは１ｎｍ以上の空孔が存在しなければよい。また、中空か否かは、ＴＥＭの観察像におけるコントラストで確認できる。なお、水の様に、中空である場合と同様のコントラストを示す場合も中空に含まれることとする。炭素結晶面の積層方向は、８０万倍以上のＴＥＭの観察像におけるコントラストで確認できる。   In the present invention, “being surrounded by a carbon crystal wall” means, in a narrow sense, that it does not have pores having a diameter of a certain size or more leading to the hollow portion. Specifically, when observed with a TEM photograph, the pore diameter is usually several tens of nm or more, preferably several nm or more, and more preferably 1 nm or more. Moreover, it can be confirmed by the contrast in the observation image of TEM whether it is hollow. In addition, the case where the same contrast as the case of being hollow is shown like water is also included in the hollow. The stacking direction of the carbon crystal plane can be confirmed by the contrast in the observation image of TEM of 800,000 times or more.

一方、「炭素結晶壁で包囲されている」とは、広義には、前述の図１（ａ）及び（ｂ）に示す様に、形態に関して、外部と導通していない完全な形態の内部空間部（中空部）を有する場合のみならず、前述の図１（ｃ）に示す様に、炭素結晶壁の一部が欠落し、形態に関して内部空間部が外部と導通している場合を含む概念である。したがって、本明細書において「中空部」とは「空間部」の下位概念である。   On the other hand, “being surrounded by a carbon crystal wall” broadly means, as shown in FIGS. 1 (a) and 1 (b), a complete internal space that is not electrically connected to the outside. Concept including not only the case of having a hollow portion (hollow portion) but also a case in which a part of the carbon crystal wall is missing and the internal space portion is electrically connected to the outside as shown in FIG. It is. Therefore, in this specification, “hollow part” is a subordinate concept of “space part”.

本発明の球状炭素粒子における「炭素結晶壁で包囲された空間部」は、１つでも、複数（炭素結晶壁で包囲されている空間部が形成され且つ当該空間部が更に炭素結晶壁で複数に分割された構造）でもよいが、１つの方が好ましい。そして、少なくとも１つの空間部の長径は、球状炭素粒子の径の通常５％以上、好ましくは１０％以上、更に好ましくは３０％以上の範囲である。また、当該空間部が更に非晶質炭素壁で複数に分割されていてもよい。なお、本発明の球状炭素粒子における空間（又は中空）とは、空気が存在する場合のみならず、内部まで炭素が充填されていなければよく、当該空間部に液体や他の固体が充填されていてもよい。   In the spherical carbon particles of the present invention, the number of “space portions surrounded by carbon crystal walls” is one or more (a space portion surrounded by carbon crystal walls is formed, and the space portions are further formed of carbon crystal walls. 1 structure is preferable. The major axis of the at least one space is usually 5% or more, preferably 10% or more, more preferably 30% or more of the diameter of the spherical carbon particles. The space may be further divided into a plurality of amorphous carbon walls. Note that the space (or hollow) in the spherical carbon particles of the present invention is not limited to the case where air is present, but it is sufficient that the interior is not filled with carbon, and the space is filled with liquid or other solids. May be.

また、炭素結晶壁の厚さは、液体媒体への分散時に低比重による分散を安定させる効果、および中空部に他の物質を担持する担体として使用する場合、担持容量の観点から、球状炭素粒子中心から壁外周までの距離（半径）に対する割合として、通常０．５以下、好ましくは０．３以下である。   In addition, the thickness of the carbon crystal wall is a spherical carbon particle from the viewpoint of the effect of stabilizing the dispersion due to low specific gravity when dispersed in a liquid medium, and the carrying capacity when used as a carrier carrying other substances in the hollow part. The ratio to the distance (radius) from the center to the outer periphery of the wall is usually 0.5 or less, preferably 0.3 or less.

そして、本発明の１つの球状炭素粒子は、粒子外周の少なくとも一部には炭素結晶端が露出した構造又は炭素網面のループ状構造を有することを特徴とする。図２は、本発明の球状炭素粒子の外周における、炭素結晶端が露出した構造および炭素網面のループ状構造の一例の模式図である。具体的に、図２は球状炭素粒子の外周表面の部分断面を拡大して示す模式図であり（図２中、左側が炭素粒子内側、右側が炭素粒子外側に当たる。）、炭素結晶の方向を曲線によって模式的に示している。図２中符号ａで表わされる、炭素網面の粒子表面側末端が閉じていない構造が、粒子表面に炭素結晶端が露出した構造（以下、適宜「結晶端露出構造」と略す。）に相当し、図２中符号ｂで表わされる、炭素網面の粒子表面側の末端同士が結合している構造が、粒子表面における炭素網面のループ状構造（以下、適宜「ループ状構造」と略す。）に相当する。なお、ループ状構造は通常、炭素網面２０層までで形成される。粒子の表面形状（結晶端露出構造、ループ状構造）は８０万倍のＴＥＭ写真によって確認できる。   One spherical carbon particle of the present invention is characterized by having a structure in which a carbon crystal edge is exposed or a loop structure of a carbon network surface at least at a part of the outer periphery of the particle. FIG. 2 is a schematic view of an example of a structure in which the ends of carbon crystals are exposed and a loop structure of a carbon network surface on the outer periphery of the spherical carbon particles of the present invention. Specifically, FIG. 2 is a schematic diagram showing an enlarged partial cross section of the outer peripheral surface of the spherical carbon particles (in FIG. 2, the left side is the inside of the carbon particle and the right side is the outside of the carbon particle), and the direction of the carbon crystal is shown. This is schematically shown by a curve. The structure represented by the symbol a in FIG. 2 where the carbon surface end of the particle surface side is not closed corresponds to a structure in which the carbon crystal ends are exposed on the particle surface (hereinafter, abbreviated as “crystal end exposed structure” where appropriate). 2 is a loop structure of the carbon network surface on the particle surface (hereinafter referred to as “loop structure” as appropriate). .) The loop-like structure is usually formed with up to 20 layers of the carbon network surface. The surface shape of the particles (crystal edge exposed structure, looped structure) can be confirmed by a 800,000 times TEM photograph.

本発明の球状炭素粒子において、これらの結晶端露出構造およびループ状構造は、球状炭素粒子の外周の少なくとも一部に存在していればよい。具体的には、これらの結晶端露出構造およびループ状構造を合わせて、球状炭素粒子の外周全表面積の通常１０％以上、好ましくは２０％以上、更に好ましくは３０％以上を占めていることが好ましい。なお、炭素繊維業界では、一般に、結晶端露出構造を加熱すると、結晶端に付着している原子などがとれてループ状になるといわれている。   In the spherical carbon particles of the present invention, these crystal end exposed structure and loop-shaped structure may be present at least at a part of the outer periphery of the spherical carbon particles. Specifically, the crystal end exposed structure and the loop-shaped structure together account for 10% or more, preferably 20% or more, and more preferably 30% or more of the total outer surface area of the spherical carbon particles. preferable. In the carbon fiber industry, it is generally said that when a crystal end exposed structure is heated, atoms attached to the crystal end are removed to form a loop.

そして、本発明の他の１つの球状炭素粒子は、集合体にした場合、半径比１．０〜１．３の範囲である球状炭素粒子の割合が４０個数％以上であることを特徴とする。ここで、半径比は、最大半径を最小半径で除した値であり、それぞれは、ＴＥＭ観察における「重心から外周部間の長さ」により、最長の値を最大半径、最小の値を最小半径とする。ＴＥＭ観察は次の様に行なう。すなわち、低倍率で数十個の粒子について観察を行い、この中から平均的粒径と見られる粒子１０個を選び、半径比が確認可能な高倍率（例えば、粒径が数百ｎｍの場合は８万倍）で観察し、画像処理し、「重心から外周部間の長さ」を計測する。本発明において、半径比が１．０以上、１．３以下の範囲である球状炭素粒子の割合は、中でも好ましくは５０個数％以上、更に好ましくは６０個数％以上、特に好ましくは７０個数％以上、最も好ましくは８０個数％以上である。   And when another spherical carbon particle of the present invention is an aggregate, the ratio of the spherical carbon particles having a radius ratio of 1.0 to 1.3 is 40% by number or more. . Here, the radius ratio is a value obtained by dividing the maximum radius by the minimum radius, and the longest value is the maximum radius and the minimum value is the minimum radius according to the “length from the center of gravity to the outer periphery” in TEM observation. And The TEM observation is performed as follows. That is, several tens of particles are observed at a low magnification, and ten particles that are considered to have an average particle diameter are selected from these, and a high magnification (for example, when the particle diameter is several hundred nm) in which the radius ratio can be confirmed. Is observed at 80,000 times), image-processed, and “the length between the center of gravity and the outer periphery” is measured. In the present invention, the ratio of the spherical carbon particles having a radius ratio in the range of 1.0 or more and 1.3 or less is preferably 50% by number or more, more preferably 60% by number or more, and particularly preferably 70% by number or more. Most preferably, it is 80% by number or more.

本発明の球状炭素粒子は、球形であるため、ファイバー等の他の形状に比べて溶液の粘度が低く、顔料として本発明の炭素粒子を使用した場合、その分散液は均質な塗布が容易に出来ることが期待され、インクジェットプリンタ用のインクとして使用した場合に、吐出し易く詰まり難いという効果が得られるものと考えられる。   Since the spherical carbon particles of the present invention are spherical, the viscosity of the solution is lower than other shapes such as fibers, and when the carbon particles of the present invention are used as a pigment, the dispersion can be easily applied uniformly. It is expected to be possible, and when used as an ink for an ink jet printer, it is considered that the effect of being easy to discharge and not clogging is obtained.

更に、粒子外周に炭素結晶端が露出した構造又は炭素網面のループ状構造を有する構造の球状炭素粒子の場合、炭素結晶配向が同心円状である場合に比べ、炭素結晶層間に他原子をインターカレートすることや、これを電界放出させることが容易であると考えられ、例えば、電界放射ディスプレイに応用したり、Ｌｉ等を加えることによりリチウム電池の作製等に応用できるものと期待される。なお、ＣＮＴ（カーボンナノチューブ）の電子放出は、五員環から優先的に電界放出が生じることが知られている（「カーボンナノチューブの基礎と応用」、齋藤理一郎・篠原久典、培風館、２００４年、ｐ．１５９〜１６９）。また、結晶端部は表面エネルギーが高いことから、他の物質との親和性が強いことが予想され、特定物質やガスの吸着体あるいは燃料電池等のデバイスでの触媒の担体として有効に利用されることが期待できる。   Furthermore, in the case of spherical carbon particles having a structure in which the ends of the carbon crystal are exposed on the outer periphery of the particle or a loop structure of the carbon network surface, other atoms are intervened between the carbon crystal layers as compared with the case where the carbon crystal orientation is concentric. It is considered that it is easy to perform calation and field emission, and it is expected that it can be applied to, for example, a field emission display or to the production of a lithium battery by adding Li or the like. In addition, it is known that electron emission of CNT (carbon nanotube) is preferentially generated from a five-membered ring ("Basic and Application of Carbon Nanotube", Riichiro Saito, Hissunori Shinohara, Bafukan, 2004, p.159-169). Also, since the crystal edge has a high surface energy, it is expected to have a strong affinity with other substances, and it is effectively used as a catalyst carrier in devices such as specific substances, gas adsorbents or fuel cells. Can be expected.

加えて、本発明の球状炭素粒子は、結晶性から期待される導電特性と共に、形状が揃っており、取り扱い易いという利点を有するが、更に、従来の炭素材料にない良好な分散性、特に水および極性溶媒に高度に分散する特性を付与することも可能である。従って、本発明の球状炭素粒子は、上記の特性を活かして各種ポリマーの導電付与材の目的で複合材料として使用される他、良好な分散性を下に帯電防止層を形成する塗布液として各種の用途が期待される。特に、表面エネルギーの高いガラス基材、ＰＥＴフィルム、ＰＶＡフィルム等に対しては、微小な粒子サイズと均一性から、透明導電膜の導電フィラーとして有効である。また、空間を有することはカプセル構造であることを意味する。そして、斯かる構造を活かし、生体内での診断試薬、モニター試薬の支持材料の分野で好適に利用される材料である。   In addition, the spherical carbon particles of the present invention have the advantage of being easy to handle and having the same shape as well as the conductive properties expected from crystallinity, but also have good dispersibility, especially water, not found in conventional carbon materials. It is also possible to impart highly dispersible properties to polar solvents. Accordingly, the spherical carbon particles of the present invention can be used as a composite material for the purpose of imparting various polymers with the above characteristics, and various coating liquids for forming an antistatic layer under good dispersibility. Is expected to be used. Particularly for glass substrates, PET films, PVA films, etc. with high surface energy, they are effective as conductive fillers for transparent conductive films because of their fine particle size and uniformity. Also, having a space means a capsule structure. And it is a material suitably utilized in the field | area of the support material of a diagnostic reagent and a monitor reagent in the living body using such a structure.

本発明の球状炭素粒子の表面特性は、製造時の原形型の表面特性または製造後の後処理などにより、制御可能である。特に、原形型としてＳｉＯ2を使用する場合に分散性が向上すると期待され、原因としては、球状炭素粒子表面に水酸基やカルボニル基などが存在していることによるものと推定される。 The surface characteristics of the spherical carbon particles of the present invention can be controlled by the surface characteristics of the original mold at the time of production or post-treatment after the production. In particular, it is expected that the dispersibility is improved when SiO 2 is used as a prototype, and this is presumed to be due to the presence of hydroxyl groups, carbonyl groups, and the like on the surface of the spherical carbon particles.

ハイパーフラーレン等の結晶構造を有する中空炭素粒子は、粒径および形状が不均一であり、溶媒分散が困難である等の問題がある。また、各種テンプレート法などで作製した粒径および形状が揃った中空炭素粒子は、結晶構造ではなくアモルファス構造となっており、導電性、電界放出性などの電気的特性に劣っている。これに対し、本発明の球状炭素粒子は、炭素結晶壁で包囲されている空間部を有し、好ましくは、更に、粒径および形状が揃っており、かつ、溶媒への高い分散性を有していることを特徴とする。そのため、本発明の球状炭素粒子は、従来の球状炭素粒子と異なる。   Hollow carbon particles having a crystal structure such as hyperfullerene have problems such as non-uniform particle size and shape and difficulty in solvent dispersion. Further, hollow carbon particles having a uniform particle size and shape produced by various template methods have an amorphous structure, not a crystal structure, and are inferior in electrical characteristics such as conductivity and field emission. In contrast, the spherical carbon particles of the present invention have a space portion surrounded by a carbon crystal wall, and preferably have a uniform particle size and shape, and have high dispersibility in a solvent. It is characterized by that. Therefore, the spherical carbon particles of the present invention are different from the conventional spherical carbon particles.

本発明の製造方法で得られる炭素粒子は、前駆体の原料の種類を選ぶことにより、炭素結晶構造を有しつつ、表面には例えば酸素および窒素原子等の前駆体原料由来の原子を有する。これらの原子は炭素粒子表面では官能基として存在し、極性溶媒との親和性を高めることに有効に作用する。炭素粒子に含まれる酸素および窒素原子の量は、通常元素分析におけるＣ，Ｈ，Ｎの測定よって定量が可能である。上記の機能を発揮する観点から、窒素原子の含有量は、通常１．０〜１２重量％、好ましくは２．０〜１０重量％である。また、酸素原子の含有量は、通常１．０〜１５重量％、好ましくは３．０〜９重量％である。炭素粒子表面に存在する官能基は、赤外吸収スペクトルまたはＸＰＳ（Ｘ線光電子分光分析）等の方法で帰属することが可能である。   The carbon particles obtained by the production method of the present invention have atoms derived from precursor raw materials such as oxygen and nitrogen atoms on the surface while having a carbon crystal structure by selecting the type of precursor raw material. These atoms exist as functional groups on the surface of the carbon particles and effectively act to increase the affinity with a polar solvent. The amount of oxygen and nitrogen atoms contained in the carbon particles can be quantified by measuring C, H, and N in ordinary elemental analysis. From the viewpoint of exhibiting the above functions, the content of nitrogen atoms is usually 1.0 to 12% by weight, preferably 2.0 to 10% by weight. The oxygen atom content is usually 1.0 to 15% by weight, preferably 3.0 to 9% by weight. The functional group present on the carbon particle surface can be assigned by a method such as infrared absorption spectrum or XPS (X-ray photoelectron spectroscopy).

次に、本発明の球状炭素粒子の集合体について説明する。   Next, the aggregate | assembly of the spherical carbon particle of this invention is demonstrated.

本発明の球状炭素粒子の集合体は、以下の方法で調製された分散液について、調製後２４時間静置して測定した以下の式（Ｉ）で表される粒径分布指標が０．１〜２０であることを特徴とする。そして、本発明の好ましい態様においては、球状炭素粒子の集合体は前記の球状炭素粒子から成る。   The aggregate of spherical carbon particles of the present invention has a particle size distribution index represented by the following formula (I) measured by standing for 24 hours after preparation in a dispersion prepared by the following method. ˜20. And in the preferable aspect of this invention, the aggregate | assembly of a spherical carbon particle consists of said spherical carbon particle.

＜分散液の調製＞
内径１３ｍｍ、容量５ｍｌのガラス容器に分散媒３ｍｌと試料１ｍｇを採り、蓋を被せ、超音波振盪器を使用し、高周波出力１２０Ｗ、発振周波数３８ｋＨｚの条件下に１分間振とうさせて試料を分散させる。 <Preparation of dispersion>
Place 3 ml of dispersion medium and 1 mg of sample in a glass container with an inner diameter of 13 mm and a capacity of 5 ml, cover the sample, and use an ultrasonic shaker to shake the sample for 1 minute under conditions of high frequency output of 120 W and oscillation frequency of 38 kHz. Let

上記の分散液の調製に使用する分散媒としては、球状炭素粒子の表面特性などに応じ、球状炭素粒子に対して不活性で且つ適切な分散媒を選択する必要がある。本発明において、分散媒の選定は次の様に行なう。すなわち、上記の分散液の調製の場合と同一要領で分散液を調製し、調製後２４時間静置し、分散液の上から１ｃｍの位置と下から１ｃｍの位置との間の中央部の分散液について目視観察した際、二次凝集粒子が実質的に存在せずに均一な分散状態が得られる分散媒を選択する。選定対象となり得る分散媒としては、後述の分散媒が挙げられるが、本発明の球状炭素粒子の場合、適切な分散媒としては例えば水を使用することが出来る。   As a dispersion medium used for the preparation of the above dispersion, it is necessary to select an appropriate dispersion medium that is inactive with respect to the spherical carbon particles according to the surface characteristics of the spherical carbon particles. In the present invention, the dispersion medium is selected as follows. That is, a dispersion is prepared in the same manner as in the preparation of the above dispersion, and is allowed to stand for 24 hours after the preparation. The dispersion at the center between the position 1 cm from the top of the dispersion and the position 1 cm from the bottom When the liquid is visually observed, a dispersion medium is selected from which a secondary dispersion particle is substantially not present and a uniform dispersion state is obtained. Examples of the dispersion medium that can be selected include those described later. In the case of the spherical carbon particles of the present invention, for example, water can be used as an appropriate dispersion medium.

粒径分布指標は、粒度分布計による動的光散乱法にて測定可能である。粒径分布指標は、０．１〜２０、好ましくは０．３〜１０である。なお、粒径分布指標の数値を判断するに当たっては、静置後に上澄み部分が式（Ｉ）を満足していても、沈殿物が生じているため、見掛け上、式（Ｉ）満たしている様な球状炭素粒子の集合体は、本発明に含まれない。   The particle size distribution index can be measured by a dynamic light scattering method using a particle size distribution meter. The particle size distribution index is 0.1 to 20, preferably 0.3 to 10. In determining the numerical value of the particle size distribution index, even if the supernatant portion satisfies the formula (I) after standing, a precipitate is formed, so that it apparently satisfies the formula (I). Such aggregates of spherical carbon particles are not included in the present invention.

また、通常、本発明の球状炭素粒子の集合体は、カーボンブラックのアグリゲートの様な凝集も二次凝集（物理的凝集）もしていない。斯かる特性は、分散性向上に対してプラスに作用し、物理的凝集しているカーボンブラックと大きく異なる。   In general, the aggregate of the spherical carbon particles of the present invention is neither aggregated nor aggregated like a carbon black aggregate (secondary aggregation (physical aggregation)). Such characteristics have a positive effect on dispersibility improvement, and are greatly different from carbon black that is physically aggregated.

なお、本発明でいう「炭素粒子」とはカーボンブラックでいうところの一次粒子に相当するものであり、「集合体」とはカーボンブラックでいうところの「ストラクチャー」ではなく、複数の一次粒子が独立して存在した状態をいう。   In the present invention, the “carbon particles” correspond to primary particles in terms of carbon black, and “aggregates” are not “structures” in terms of carbon black, but a plurality of primary particles. The state that existed independently.

ところで、上記分散液の調製方法については、超音波振盪器を使用せず、簡便な方法を採用することが可能である。すなわち、本発明の炭素粒子は溶媒への分散性が非常によいため、単に手で上記試料サンプルを充分に振盪させれば、超音波振盪器を使用した場合と同等の粒径分布指標の値を得ることが出来る。   By the way, about the preparation method of the said dispersion liquid, it is possible to employ | adopt a simple method, without using an ultrasonic shaker. That is, since the carbon particles of the present invention have very good dispersibility in a solvent, if the sample sample is sufficiently shaken by hand, the value of the particle size distribution index equivalent to that when using an ultrasonic shaker is used. Can be obtained.

次に、本発明に係る球状炭素粒子の分散体について説明する。本発明の分散体は、分散媒中に前記の球状炭素粒子またはその集合体を分散して成ることを特徴とする。   Next, the spherical carbon particle dispersion according to the present invention will be described. The dispersion of the present invention is characterized in that the spherical carbon particles or aggregates thereof are dispersed in a dispersion medium.

分散媒としては、特に限定されず、極性溶媒または非極性溶媒の何れでもよい。極性溶媒としては、水の他、メタノール、エタノール、イソプロピルアルコール等のアルコール類、エチレングリコール、プロピレングリコール等のグリコール類、テトラヒドロフラン、ジエチルエーテル等のエーテル類、エチレングリコールモノエチルエーテル、エチレングリコールモノメチルエーテル、プロピレングリコールモノメチルエーテル等のグリコール類のモノアルキルエーテル類、アセトン、メチルエチルケトン等のケトン類、酢酸エチル等のエステル類、エチレンカーボネート、プロピレンカーボネート等カーボネート類などが挙げられ、非極性溶媒としては、各種のアルカン類、芳香族類およびこれらの混合物などが挙げられる。これらの中では、親和性が高く、分散性が良好であるとの観点から、極性溶媒が好ましく、水およびアルコール類が更に好ましい。   The dispersion medium is not particularly limited and may be either a polar solvent or a nonpolar solvent. Examples of polar solvents include water, alcohols such as methanol, ethanol and isopropyl alcohol, glycols such as ethylene glycol and propylene glycol, ethers such as tetrahydrofuran and diethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, Examples include monoalkyl ethers of glycols such as propylene glycol monomethyl ether, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, carbonates such as ethylene carbonate and propylene carbonate, etc. Examples include alkanes, aromatics and mixtures thereof. Among these, a polar solvent is preferable from the viewpoint of high affinity and good dispersibility, and water and alcohols are more preferable.

なお、球状炭素粒子に加えて、分散媒に高分散可能な物質、例えば、水溶性樹脂、有機溶可溶樹脂、セメント、シリケート、セラミックス等を更に添加した後、分散媒を除去することにより、高分散複合体を得ることも出来る。   In addition to spherical carbon particles, after further adding a substance that can be highly dispersed in the dispersion medium, for example, a water-soluble resin, an organic soluble resin, cement, silicate, ceramics, and the like, by removing the dispersion medium, A highly dispersed composite can also be obtained.

分散媒中の球状炭素粒子の割合は、通常０．１〜１０重量％であり、分散媒中への球状炭素粒子の分散には、機械的な撹拌の他、ペイントシェイカー等の機械的な振盪方法、超音波照射などの手段を採用することが出来る。また、必要に応じ界面活性剤を使用してもよい。   The ratio of the spherical carbon particles in the dispersion medium is usually 0.1 to 10% by weight. For the dispersion of the spherical carbon particles in the dispersion medium, mechanical shaking such as a paint shaker is used in addition to mechanical stirring. Means such as a method and ultrasonic irradiation can be employed. Moreover, you may use surfactant as needed.

なお、表面修飾により、または、界面活性剤や高分子修飾剤により、分散性が向上された炭素粒子については、これらの改善手法が施されたままのサンプルを使用して上記粒径分布指標を測定することになる。   For carbon particles whose dispersibility has been improved by surface modification or by a surfactant or polymer modifier, the particle size distribution index is determined using a sample that has been subjected to these improvement techniques. Will be measured.

本発明の分散体は次の様な特徴を有する。すなわち、粒径が揃っているため、分散溶媒中での粒子の沈降速度が一定であり、経時的に安定で、均一な懸濁液を得ることが可能である。また、特に分散媒が極性溶媒で球状炭素粒子の表面に親水性基が存在する場合は、一層良好に分散され、凝集体が形成され難い。   The dispersion of the present invention has the following characteristics. That is, since the particle diameters are uniform, the sedimentation rate of the particles in the dispersion solvent is constant, and it is possible to obtain a stable and uniform suspension over time. In particular, when the dispersion medium is a polar solvent and a hydrophilic group is present on the surface of the spherical carbon particles, the dispersion is more favorably dispersed and it is difficult to form an aggregate.

本発明の分散体における分散粒径は、粒度分布計による動的光散乱法またはレーザー回折散乱法にて測定可能である。具体的には、前記の方法で分散を行った後、２４時間静置した後の分散液について測定する。ここで、測定レンジ以上のサイズである２００μｍ以上の粒子または凝集物を除いた粒子について平均粒径を分散粒径とする。なお、２００μｍ以上の粒子は、動的光散乱およびレーザー回折法の何れの方法でも一般に測定検知能力の範囲外であり、光学顕微鏡にてその存在を確認することが出来る。   The dispersed particle size in the dispersion of the present invention can be measured by a dynamic light scattering method or a laser diffraction scattering method using a particle size distribution meter. Specifically, after the dispersion is performed by the above method, the dispersion is measured after being allowed to stand for 24 hours. Here, the average particle diameter of the particles excluding particles or aggregates of 200 μm or more which is the size of the measurement range or more is defined as the dispersed particle diameter. Incidentally, particles having a particle size of 200 μm or more are generally outside the range of measurement and detection ability by any of the dynamic light scattering and laser diffraction methods, and their presence can be confirmed with an optical microscope.

本発明の分散体においては、通常、１００個以上の粒子を観察した場合、全測定粒子の９０体積％以上が６０μｍ以下の粒径または凝集サイズであることが好ましく、３０μｍ以下の粒径または凝集サイズであることが更に好ましい。   In the dispersion of the present invention, usually, when 100 or more particles are observed, 90% by volume or more of all measured particles preferably have a particle size or agglomerated size of 60 μm or less, and a particle size or agglomerate of 30 μm or less. More preferably, it is a size.

以下、本発明を実施例により更に詳細に説明するが、本発明は、その要旨を超えない限り、以下の実施例に限定されるものではない。   EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded.

実施例１：
先ず、次の要領でコアシェル粒子を合成した。すなわち、水３４５ｇにメタクリル酸メチル３１．６６ｇとメタクリル酸１．３２ｇを混合し、窒素ガスのフロー下で３００ｒｐｍで撹拌しながら、室温から昇温し、７５℃で過硫酸カリウム水溶液（０．１ｇを水５ｇで溶解した水溶液）を加えて重合を開始し、７５℃で３時間重合した。転化率は９２％であった。このコア粒子の分散液４６．９ｇに「ラテムルＡＤ−２５」（花王（株）製）１．０ｇ、過硫酸カリウム０．１６ｇ、水１５３ｇを混合し、窒素ガスのフロー下で３００ｒｐｍで撹拌しながら室温から昇温し、７０℃になったところで、アクリロニトリル６．１ｇ、アクリル酸メチル１．１０ｇ、ｎ−オクチルメルカプタン０．２２ｇの混合液の滴下を開始し、１時間１５分で滴下を終了した。その後、更に重合を５時間行った。この分散液を１８０００ｒｐｍの条件で遠心分離し、上澄み液を除去し、更に、沈殿のコアシェル粒子を同様の方法で３回水洗し、固形分率１２．８％のコアシェル粒子の分散液を得た。また、６万倍のＳＥＭで観察したところ、粒径４２５〜４３８ｎｍの球状粒子であった。 Example 1:
First, core-shell particles were synthesized as follows. That is, 31.66 g of methyl methacrylate and 1.32 g of methacrylic acid were mixed with 345 g of water, the temperature was raised from room temperature while stirring at 300 rpm under a flow of nitrogen gas, and an aqueous potassium persulfate solution (0.1 g) at 75 ° C. Was added with 5 g of water to start polymerization, and polymerization was performed at 75 ° C. for 3 hours. The conversion rate was 92%. 46.9 g of this core particle dispersion was mixed with 1.0 g of “Latemul AD-25” (manufactured by Kao Corporation), 0.16 g of potassium persulfate and 153 g of water, and stirred at 300 rpm under a flow of nitrogen gas. However, when the temperature was raised from room temperature to 70 ° C., dropping of a mixed solution of 6.1 g of acrylonitrile, 1.10 g of methyl acrylate and 0.22 g of n-octyl mercaptan was started, and dropping was completed in 1 hour and 15 minutes. did. Thereafter, further polymerization was carried out for 5 hours. This dispersion was centrifuged at 18000 rpm, the supernatant was removed, and the precipitated core-shell particles were washed with water three times in the same manner to obtain a dispersion of core-shell particles with a solid content of 12.8%. . Moreover, when observed with a 60,000 times SEM, it was a spherical particle with a particle size of 425-438 nm.

一方、水３．６４ｇとエタノール４．６５ｇの混合液にメチルシリケートオリゴマー（三菱化学製「ＭＳ５１」）５．２６ｇを混合して分散した後、１ｍｏｌ／Ｌの塩酸を混合し、ｐＨ４の液を調製した。室温で１時間撹拌し、メチルシシリケートオリゴマーを加水分解し、均一な溶液としてシリカゾルを調製した。   On the other hand, 5.26 g of a methyl silicate oligomer (“MS51” manufactured by Mitsubishi Chemical Corporation) is mixed and dispersed in a mixed liquid of 3.64 g of water and 4.65 g of ethanol, and then 1 mol / L hydrochloric acid is mixed to obtain a liquid having a pH of 4. Prepared. The mixture was stirred at room temperature for 1 hour to hydrolyze the methyl silicate oligomer to prepare a silica sol as a uniform solution.

上記のコアシェル粒子のエマルジョン０．６２ｇ（ポリマー粒子量０．０７９ｇ）に上記のシリカゾル１．８５ｇを加え、振とうして混合した後、この後、密栓して３日間静置して流動性のないゲルを得、ポリマー粒子を含むシリカゲルを作製した。このゲルをガラス皿に移し、室温で１０時間減圧乾燥した。   1.85 g of the above silica sol was added to 0.62 g of the above-described emulsion of core-shell particles (polymer particle amount 0.079 g), mixed by shaking, and then sealed and left to stand for 3 days. No gel was obtained and silica gel containing polymer particles was made. This gel was transferred to a glass dish and dried under reduced pressure at room temperature for 10 hours.

次いで、上記で得られた乾燥ゲルを電気炉にて常圧下に窒素雰囲気でのフロー系で室温から５℃／分で１０００℃まで昇温し、１０００℃で１時間保持してポリマー粒子を炭素化した。その後、加熱を停止し、電気炉が室温まで冷却された１２時間後に試料を取り出した。これを、１ｍｏｌ／Ｌの水酸化ナトリウム水溶液６０ｍｌに混合し、耐圧容器に入れ、オーブン中１７０℃で６時間加熱してシリカゲルを溶解し、炭素化粒子が分散した分散液を得た。この分散液を１８０００ｒｐｍの条件で遠心分離し、上澄み液を除去し、更に沈殿の炭素化粒子を同様の方法で３回水洗し、炭素粒子の分散液を得た。   Subsequently, the dried gel obtained above was heated from room temperature to 1000 ° C. at 5 ° C./min in a flow system in a nitrogen atmosphere under normal pressure in an electric furnace, and held at 1000 ° C. for 1 hour to obtain polymer particles as carbon. Turned into. Thereafter, heating was stopped, and a sample was taken out 12 hours after the electric furnace was cooled to room temperature. This was mixed with 60 ml of a 1 mol / L sodium hydroxide aqueous solution, placed in a pressure vessel, heated in an oven at 170 ° C. for 6 hours to dissolve the silica gel, and a dispersion in which carbonized particles were dispersed was obtained. This dispersion was centrifuged at 18000 rpm, the supernatant was removed, and the precipitated carbonized particles were washed with water three times in the same manner to obtain a carbon particle dispersion.

上記の分散液を超音波にて３分間分散し、その中から任意の３滴をガラス板に採り、光学顕微鏡（倍率：１００倍）で観察したところ、何れの滴にも１００μｍ以上の炭素粒子およびその凝集物は観察されなかった。   The above dispersion was dispersed for 3 minutes with ultrasonic waves, and any 3 drops were taken on a glass plate and observed with an optical microscope (magnification: 100 times). And no aggregates were observed.

上記の分散液中の粒子の構造をＴＥＭ（倍率１２万倍）で観察したところ、粒径４１０〜４２０ｎｍの球状粒子であった（図３参照）。また、壁の厚さは２５ｎｍであり、粒子内部に炭素結晶壁で包囲された中空部を１つ有していた。また、この球状炭素粒子の集合体は凝集していなかった。結晶壁厚みの粒子半径に対する比は１２．０％であり、中空による粒子内の空間容積は充分に大きいものであった。   When the structure of the particles in the dispersion was observed with a TEM (magnification: 120,000 times), it was spherical particles having a particle size of 410 to 420 nm (see FIG. 3). The wall had a thickness of 25 nm, and had one hollow portion surrounded by a carbon crystal wall inside the particle. Further, the aggregate of the spherical carbon particles was not aggregated. The ratio of the crystal wall thickness to the particle radius was 12.0%, and the space volume in the particles due to the hollow was sufficiently large.

動的光散乱式の粒度分布測定器（ハネウエル社製「ＭｉｃｒｏｓｏｆｔＵＳＡモデル：９３０−ＵＳＡ」）により、上述の動的光散乱式の粒度分布測定器により、上記の粒子の水に対する分散状態を測定したところ、５０％体積分布粒径が５１５ｎｍ、１０％体積分布粒径が３６３ｎｍ、９０％体積分布粒径が６６７ｎｍ、粒径分布指標が０．５９の値を持つ単分散の粒径分布であった。更に、平均的粒子１０個について画像処理を行い、その半径比を算出したしたところ、各々、１．０４、１．０６、１．０７、１．０７、１．０７、１．０７、１．０７、１．０７、１．０８、１．０９であった。すなわち、半径比が１．０〜１．３の範囲である球状炭素粒子の割合は１００個数％であった。   The dispersion state of the above-mentioned particles in water was measured with a dynamic light scattering particle size distribution analyzer (“Microsoft USA model: 930-USA” manufactured by Honeywell) using a dynamic light scattering particle size distribution analyzer. However, it was a monodispersed particle size distribution with a 50% volume distribution particle size of 515 nm, a 10% volume distribution particle size of 363 nm, a 90% volume distribution particle size of 667 nm, and a particle size distribution index of 0.59. . Further, image processing was performed on 10 average particles, and the radius ratio was calculated, and 1.04, 1.06, 1.07, 1.07, 1.07, 1.07, 1. 07, 1.07, 1.08, and 1.09. That is, the ratio of spherical carbon particles having a radius ratio in the range of 1.0 to 1.3 was 100% by number.

上記の粒子の結晶化度をＸＲＤ測定における２θ＝２５．７°に現れたピーク解析で行ったところ、ピーク半値幅は４．３０°で結晶子の面間距離は３．４６Åと算出された。また、元素分析結果は、炭素、窒素、酸素が主な構成元素であり、検出濃度は炭素７９．５０重量％、窒素６．２７重量％、酸素１３．４５重量％であった。なお、上記以外の成分として、水素は０．７８重量％、ケイ素は１重量％の検出限界以下であった。   When the crystallinity of the above particles was analyzed by peak analysis at 2θ = 25.7 ° in XRD measurement, the peak half-value width was 4.30 ° and the crystallite face-to-face distance was calculated to be 3.46 mm. . The elemental analysis results showed that carbon, nitrogen and oxygen were the main constituent elements, and the detected concentrations were 79.50% by weight of carbon, 6.27% by weight of nitrogen and 13.45% by weight of oxygen. As components other than the above, hydrogen was 0.78% by weight and silicon was 1% by weight or less.

また、X線光電子分光法により、本実施例の炭素粒子の表面官能基の分析を行い、ピーク分離により、Ｃ−ＯＨ，Ｃ＝Ｏ，COOR（Ｒはアルキル基）のピークを確認した。また、フーリエ変換赤外分光法（拡散反射法を使用）による測定で３４００ｃｍ−１付近にＯＨ伸縮振動が観察され、ＯＨ基の存在が確認された。 Further, the surface functional groups of the carbon particles of this example were analyzed by X-ray photoelectron spectroscopy, and peaks of C—OH, C═O, COOR (R is an alkyl group) were confirmed by peak separation. In addition, OH stretching vibration was observed in the vicinity of 3400 cm −1 as measured by Fourier transform infrared spectroscopy (using diffuse reflection method), and the presence of OH groups was confirmed.

実施例２：
先ず、次の要領でアクリロニトリルとアクリル酸メチルの共重合ポリマー微粒子を合成した。すなわち、ドデシル硫酸ナトリウム０．３２ｇを水１４５ｇに溶解し、ここにアクリロニトリル１２．７１ｇ、アクリル酸メチル１．８３ｇ、メタアクリル酸０．４６ｇ、ｎ−ブチルメルカプタン０．３ｇの混合物を加え、窒素ガスのフロー下で３００ｒｐｍで撹拌しながら、室温から昇温し、６０℃で過硫酸カリウム水溶液（０．１ｇを水５ｇで溶解した水溶液）を加えて重合を開始し、７０℃で３時間重合した。反応停止後、水を除去し、平均粒径１３０ｎｍ（前述の動的光散乱式の粒度分布測定器での測定値）のアクリル樹脂粒子１２．５ｇを含む懸濁液を調製した。この樹脂粒子の元素分析（Ｃ、Ｈ、Ｎ）による窒素量から換算されるアクリロニトリル単位の割合は７９．５重量％であり、サイズ排除クロマトグラフィー（ＳＥＣ）によるポリスチレン（ＰＳｔ）換算での重量平均分子量は４．１×１０４であった。得られたアクリル粒子を６万倍のＳＥＭで観察したところ、粒径１１５〜１４８ｎｍの球状粒子であった。 Example 2:
First, copolymer fine particles of acrylonitrile and methyl acrylate were synthesized in the following manner. That is, 0.32 g of sodium dodecyl sulfate was dissolved in 145 g of water, and a mixture of 12.71 g of acrylonitrile, 1.83 g of methyl acrylate, 0.46 g of methacrylic acid, and 0.3 g of n-butyl mercaptan was added thereto, and nitrogen gas was added. The mixture was heated from room temperature while stirring at 300 rpm under the flow of, and an aqueous potassium persulfate solution (an aqueous solution in which 0.1 g was dissolved in 5 g of water) was added at 60 ° C. to initiate polymerization, and polymerization was carried out at 70 ° C. for 3 hours. . After the reaction was stopped, water was removed to prepare a suspension containing 12.5 g of acrylic resin particles having an average particle size of 130 nm (measured with the above-mentioned dynamic light scattering type particle size distribution analyzer). The proportion of acrylonitrile units converted from the amount of nitrogen by elemental analysis (C, H, N) of the resin particles is 79.5% by weight, and the weight average of polystyrene (PSt) converted by size exclusion chromatography (SEC) The molecular weight was 4.1 × 10 4 . When the obtained acrylic particles were observed with an SEM of 60,000 times, they were spherical particles having a particle diameter of 115 to 148 nm.

一方、水３．８７ｇとエタノール４．９４ｇの混合液にメチルシリケートオリゴマー（三菱化学製「ＭＳ５１」）５．５９ｇを混合して分散した後、１ｍｏｌ／Ｌの塩酸を混合し、ｐＨ２の液を調製した。５０℃で１時間撹拌し、メチルシシリケートオリゴマーを加水分解し、均一な溶液としてシリカゾルを調製した。   On the other hand, 5.59 g of a methyl silicate oligomer (“MS51” manufactured by Mitsubishi Chemical Corporation) was mixed and dispersed in a mixed liquid of 3.87 g of water and 4.94 g of ethanol, 1 mol / L hydrochloric acid was mixed, and a liquid having a pH of 2 was added. Prepared. The mixture was stirred at 50 ° C. for 1 hour to hydrolyze the methyl silicate oligomer to prepare a silica sol as a uniform solution.

次いで、上記のアクリル粒子のエマルジョン０．５２ｇ（ポリマー粒子量０．０４３ｇ）に上記のシリカゾル１．５８ｇを加え、振とうして混合した後、８ｃｍ径のテフロン（登録商標）製シャーレーに展開し、４０℃のホットプレート上で５時間加熱して乾燥し、ポリマー粒子が分散したシリカゲルを得た。このゲルをガラス皿に移し、室温１０時間減圧乾燥した。   Next, 1.58 g of the above silica sol was added to 0.52 g of the above acrylic particle emulsion (polymer particle amount 0.043 g), mixed by shaking, and then developed on an 8 cm diameter Teflon (registered trademark) petri dish. And dried on a hot plate at 40 ° C. for 5 hours to obtain silica gel in which polymer particles are dispersed. This gel was transferred to a glass dish and dried under reduced pressure at room temperature for 10 hours.

上記で得られた乾燥ゲルを電気炉にて常圧下に窒素雰囲気でのフロー系で室温から５℃／分で１０００℃まで昇温し、１０００℃で１時間保持してポリマー粒子を炭素化した。その後、加熱を停止し、電気炉が室温にまで冷却された１２時間後に試料を取り出した。これを、１ｍｏｌ／Ｌの水酸化ナトリウム水溶液３０ｍｌに混合し、耐圧容器に入れ、オーブン中１７０℃で６時間加熱してシリカゲルを溶解し、炭素化粒子が分散した分散液を得た。この分散液を１８０００ｒｐｍの条件で遠心分離し、上澄み液を除去し、更に、沈殿の炭素化粒子を同様の方法で３回水洗し、炭素粒子の分散液を得た。   The dried gel obtained above was heated from room temperature to 1000 ° C. at 5 ° C./min in a flow system in a nitrogen atmosphere under normal pressure in an electric furnace, and held at 1000 ° C. for 1 hour to carbonize the polymer particles. . Thereafter, heating was stopped, and a sample was taken out 12 hours after the electric furnace was cooled to room temperature. This was mixed with 30 ml of a 1 mol / L aqueous sodium hydroxide solution, placed in a pressure vessel, heated in an oven at 170 ° C. for 6 hours to dissolve the silica gel, and a dispersion in which carbonized particles were dispersed was obtained. This dispersion was centrifuged at 18000 rpm, the supernatant was removed, and the precipitated carbonized particles were washed with water three times in the same manner to obtain a dispersion of carbon particles.

上記の分散液を超音波にて３分間分散し、その中から任意の３滴をガラス板に採り、光学顕微鏡（倍率：１００倍）で観察したところ、何れの滴にも１００μｍ以上の炭素粒子およびその凝集物は観察されなかった。   The above dispersion was dispersed for 3 minutes with ultrasonic waves, and any 3 drops were taken on a glass plate and observed with an optical microscope (magnification: 100 times). And no aggregates were observed.

上記の分散液中の粒子の構造を透過型電子顕微鏡（ＴＥＭ）（倍率：８万倍）で観察したところ、粒径１１３〜１５０ｎｍの球状粒子であった。また、壁の厚さは１０〜１５ｎｍであった。結晶壁厚みの粒子半径に対する比は１９．０％であり、中空による粒子内の空間容積は充分に大きいものであった。また、粒子内部に炭素結晶壁で包囲された中空部を１つ有し、アスペクト比１の球状炭素粒子であった。また、凝集体は視野に存在しなかった。更に、平均的粒子１０個について画像処理を行い、その半径比を算出したところ、各々、１．０８、１．１１、１．１２、１．１４、１．１４、１．１７、１．１７、１．２５、１．４３、１．８８であった。すなわち、半径比が１．０〜１．３の範囲である球状炭素粒子の割合は８０個数％であった。   When the structure of the particles in the dispersion was observed with a transmission electron microscope (TEM) (magnification: 80,000 times), it was spherical particles having a particle diameter of 113 to 150 nm. The wall thickness was 10-15 nm. The ratio of the crystal wall thickness to the particle radius was 19.0%, and the space volume in the particles due to the hollow was sufficiently large. Moreover, it was a spherical carbon particle having one hollow portion surrounded by a carbon crystal wall inside the particle and having an aspect ratio of 1. Moreover, the aggregate did not exist in the visual field. Furthermore, image processing was performed on 10 average particles, and the radius ratios were calculated. As a result, 1.08, 1.11, 1.12, 1.14, 1.14, 1.17, 1.17 were obtained. 1.25, 1.43, and 1.88. That is, the proportion of spherical carbon particles having a radius ratio in the range of 1.0 to 1.3 was 80% by number.

動的光散乱式の粒度分布測定器（ハネウエル社製「ＭｉｃｒｏｔｒａｃＵＳＡモデル：９３０−ＵＰＡ」）により、上記の粒子の水に対する分散状態を測定したところ、５０％体積分布粒径が１３８ｎｍ、１０％体積分布の粒径が８ｎｍ、９０％体積分布の粒径が２２４ｎｍ、粒径分布指標が１．０３の値を持つ粒径分布であった。   When the dispersion state of the above particles in water was measured with a dynamic light scattering type particle size distribution measuring instrument (“Microtrac USA model: 930-UPA” manufactured by Honeywell), the 50% volume distribution particle size was 138 nm, 10% volume. The particle size distribution was 8 nm, the 90% volume distribution particle size was 224 nm, and the particle size distribution index was 1.03.

上記の粒子の結晶化度をＸＲＤ測定における２θ＝２５．８°に現れたピーク解析で行ったところ、ピーク半値幅は４．０３°で結晶子の面間距離は３．４５Åと算出された。また、元素分析結果は、炭素、窒素、酸素が主な構成元素であり、検出濃度は、炭素８２．０７重量％、窒素６．３７重量％、酸素１１．０２重量％であった。なお、上記以外の元素として、水素０．５４重量％、ケイ素は１重量％の検出限界以下であった。   When the crystallinity of the above particles was analyzed by peak analysis at 2θ = 25.8 ° in XRD measurement, the peak half-value width was 4.03 ° and the crystallite face-to-face distance was calculated to be 3.45 °. . The elemental analysis results showed that carbon, nitrogen, and oxygen were the main constituent elements, and the detected concentrations were 82.07 wt% carbon, 6.37 wt% nitrogen, and 11.02 wt% oxygen. As elements other than the above, hydrogen was 0.54 wt% and silicon was 1 wt% or less.

X線光電子分光法により、本実施例の炭素粒子の表面官能基の分析を行い、ピーク分離により、Ｃ−ＯＨ，Ｃ＝Ｏ，COOR（Ｒはアルキル基）のピークを確認した。また、フーリエ変換赤外分光法（拡散反射法を使用）による測定で３４００ｃｍ−１付近にＯＨ伸縮振動が観察され、ＯＨ基の存在が確認された。 The surface functional groups of the carbon particles of this example were analyzed by X-ray photoelectron spectroscopy, and the peaks of C—OH, C═O, COOR (R is an alkyl group) were confirmed by peak separation. In addition, OH stretching vibration was observed in the vicinity of 3400 cm −1 as measured by Fourier transform infrared spectroscopy (using diffuse reflection method), and the presence of OH groups was confirmed.

実施例３：
先ず、次の要領でアクリロニトリルとアクリル酸メチルの共重合ポリマー微粒子を合成した。すなわち、ドデシル硫酸ナトリウム０．４２ｇを水１１５ｇに溶解し、ここにアクリロニトリル２５．９６ｇ、アクリル酸メチル１３．７６ｇ、メタアクリル酸０．２８ｇの混合物を加え、窒素ガスのフロー下で３００ｒｐｍで撹拌しながら、室温から昇温し、６０℃で過硫酸カリウム水溶液（０．１ｇを水５ｇで溶解した水溶液）を加えて重合を開始し、７０℃で３時間重合した。これにより平均粒径１３０ｎｍ（前述の動的光散乱式の粒度分布測定器での測定値）のアクリル樹脂粒子１０ｇを含む懸濁液を調製した。この樹脂粒子の元素分析（Ｃ、Ｈ、Ｎ）による窒素量から換算されるアクリロニトリル単位の割合は６３．５重量％であり、サイズ排除クロマトグラフィー（ＳＥＣ）によるポリスチレン（ＰＳｔ）換算での重量平均分子量は８１万であった。得られたアクリル粒子を６万倍のＳＥＭで観察したところ、粒径１２０ｎｍの球状粒子であった。 Example 3:
First, copolymer fine particles of acrylonitrile and methyl acrylate were synthesized in the following manner. That is, 0.42 g of sodium dodecyl sulfate was dissolved in 115 g of water, and a mixture of 25.96 g of acrylonitrile, 13.76 g of methyl acrylate and 0.28 g of methacrylic acid was added thereto, and the mixture was stirred at 300 rpm under a nitrogen gas flow. However, the temperature was raised from room temperature, and an aqueous potassium persulfate solution (an aqueous solution in which 0.1 g was dissolved in 5 g of water) was added at 60 ° C. to initiate polymerization, and polymerization was carried out at 70 ° C. for 3 hours. As a result, a suspension containing 10 g of acrylic resin particles having an average particle size of 130 nm (measured with the above-described dynamic light scattering particle size distribution measuring device) was prepared. The proportion of acrylonitrile units converted from the amount of nitrogen by elemental analysis (C, H, N) of the resin particles is 63.5% by weight, and the weight average in terms of polystyrene (PSt) by size exclusion chromatography (SEC) The molecular weight was 810,000. When the obtained acrylic particles were observed with an SEM of 60,000 times, they were spherical particles having a particle diameter of 120 nm.

次いで、水１０．４１ｇに１ｍｏｌ／Ｌの塩酸を添加してｐＨ１．８に調整した後、エタノール１３．３１ｇを加え、この混合液にメチルシリケートオリゴマー（三菱化学製「ＭＳ５１」）１５．０４ｇを加えて分散後、更に１ｍｏｌ／Ｌの塩酸を加えてｐＨ２．０に調整した。５０℃で２時間撹拌してメチルシリケートオリゴマーを加水分解し、均一な溶液としてシリカゾルを調製した。   Subsequently, 1 mol / L hydrochloric acid was added to 10.41 g of water to adjust the pH to 1.8. Then, 13.31 g of ethanol was added, and 15.04 g of methyl silicate oligomer (“MS51” manufactured by Mitsubishi Chemical Corporation) was added to this mixed solution. In addition, after dispersion, 1 mol / L hydrochloric acid was further added to adjust the pH to 2.0. The mixture was stirred at 50 ° C. for 2 hours to hydrolyze the methyl silicate oligomer to prepare a silica sol as a uniform solution.

次いで、上記のアクリル粒子のエマルジョン５．２０ｇ（ポリマー粒子量１．３ｇ）に上記のシリカゾル１５．７７ｇを加え、振とうして混合した後、８ｃｍ径のテフロン（登録商標）製シャーレに展開し、４０℃のオーブン中で開放系で１時間加熱乾燥してゲル化させ、更にそのまま１９時間加熱して乾燥させ、ポリマー粒子が分散したシリカゲルを得た。このゲルをガラス皿に移し、室温で１０時間減圧乾燥した。   Next, 15.77 g of the above silica sol was added to 5.20 g of the above acrylic particle emulsion (1.3 g of polymer particles), and the mixture was shaken and mixed, and then developed in an 8 cm diameter Teflon (registered trademark) petri dish. In an oven at 40 ° C., the mixture was heated and dried in an open system for 1 hour to gel, and further heated and dried for 19 hours to obtain silica gel in which polymer particles were dispersed. This gel was transferred to a glass dish and dried under reduced pressure at room temperature for 10 hours.

上記で得られた乾燥ゲルを電気炉により常圧下、窒素雰囲気のフロー系で、室温から５℃／分で１０００℃まで昇温し、１０００℃で１時間保持してポリマー粒子を炭素化した。その後、加熱を停止し、電気炉が室温にまで冷却された１２時間後に試料を取り出した。これを１ｍｏｌ／Ｌの水酸化ナトリウム水溶液３０ｍｌに混合し、耐圧容器に入れ、オーブン中１７０℃で６時間加熱してシリカゲルを溶解し、炭素化粒子が分散した分散液を得た。この分散液を１８０００ｒｐｍの条件で遠心分離し、上澄み液を除去し、更に沈殿の炭素化粒子を同様の方法で３回水洗し、炭素粒子の分散液を得た。   The dried gel obtained above was heated from room temperature to 1000 ° C. at 5 ° C./min in a nitrogen atmosphere flow system with an electric furnace under normal pressure and kept at 1000 ° C. for 1 hour to carbonize the polymer particles. Thereafter, heating was stopped, and a sample was taken out 12 hours after the electric furnace was cooled to room temperature. This was mixed with 30 ml of a 1 mol / L sodium hydroxide aqueous solution, placed in a pressure vessel, heated in an oven at 170 ° C. for 6 hours to dissolve the silica gel, and a dispersion in which carbonized particles were dispersed was obtained. This dispersion was centrifuged at 18000 rpm, the supernatant was removed, and the precipitated carbonized particles were washed with water three times in the same manner to obtain a carbon particle dispersion.

上記の分散液を超音波にて３分間分散し、その中から無作為に３滴をガラス板に採り、光学顕微鏡（倍率：１００倍）で観察したところ、何れの滴にも１００μｍ以上の炭素粒子およびその凝集物は観察されなかった。   The above dispersion was dispersed with an ultrasonic wave for 3 minutes, and 3 drops were randomly picked from a glass plate and observed with an optical microscope (magnification: 100 times). Particles and their aggregates were not observed.

上記の分散液中の粒子の構造を、透過型電子顕微鏡（ＴＥＭ）で観察した（倍率：１３０万倍）。ＴＥＭ観察写真により、本実施例で得られた分散液中の粒子は、その内部に炭素結晶壁で包囲された中空部を１つ有し、アスペクト比が１の球状炭素粒子であることが分かった。この中空炭素粒子は、炭素結晶端が外周に露出した構造を備えていた。従って、図１（ａ）に示す様に結晶が接線と略平行な方向に積層した構造であることが確認された。また、この球状炭素粒子を８万倍で観察したところ、凝集体は視野に存在しなかった。球状炭素粒子の粒径は１１５〜１３０ｎｍ、炭素結晶壁の厚さは１３〜２４ｎｍであった。結晶壁厚みの粒子半径に対する比は１５．１％であり、中空による粒子内の空間容積は充分に大きいものであった。更に、平均的粒子１０個について画像処理を行い、その半径比を算出したところ、各々、１．１８、１．１６、１．１２、１．０８、１．２１、１．２１、１．０８、１．０５、１．４３、１．８９であった。すなわち、半径比が１．０〜１．３の範囲である球状炭素粒子の割合は８０個数％であった。   The structure of the particles in the dispersion was observed with a transmission electron microscope (TEM) (magnification: 1.3 million times). From the TEM observation photograph, it was found that the particles in the dispersion obtained in this example were spherical carbon particles having one hollow portion surrounded by a carbon crystal wall inside and having an aspect ratio of 1. It was. This hollow carbon particle had a structure in which the end of the carbon crystal was exposed to the outer periphery. Therefore, it was confirmed that the crystal was laminated in a direction substantially parallel to the tangent line as shown in FIG. Further, when the spherical carbon particles were observed at a magnification of 80,000, no aggregates were present in the visual field. The spherical carbon particles had a particle size of 115 to 130 nm and a carbon crystal wall thickness of 13 to 24 nm. The ratio of the crystal wall thickness to the particle radius was 15.1%, and the space volume in the particles due to the hollow was sufficiently large. Further, image processing was performed on 10 average particles, and the radius ratios thereof were calculated, and 1.18, 1.16, 1.12, 1.08, 1.21, 1.21, 1.08, respectively. 1.05, 1.43, and 1.89. That is, the proportion of spherical carbon particles having a radius ratio in the range of 1.0 to 1.3 was 80% by number.

動的光散乱式の粒度分布測定器（ハネウエル社製「ＭｉｃｒｏｓｏｆｔＵＳＡモデル：９３０−ＵＳＡ」）により、上記の粒子の水に対する分散状態を測定したところ、分布中心の粒径が１８６ｎｍ、１０％体積分布の粒径が９０ｎｍ、９０％個数分布の粒径が２８６ｎｍ、粒径分布指標が１．０５７の値を持つ粒径分布であった。   When the dispersion state of the above particles in water was measured with a dynamic light scattering type particle size distribution analyzer (“Microsoft USA model: 930-USA” manufactured by Honeywell), the particle size at the center of distribution was 186 nm, and the volume distribution was 10%. The particle size distribution was 90 nm, the 90% number distribution particle size was 286 nm, and the particle size distribution index was 1.057.

上記の粒子の結晶化度を調べるため、ＸＲＤ測定における２θ＝２５．８°に現れたピーク解析を行なったところ、ピーク半値幅は４．２５°で、結晶子の面間距離は３．４５Åと算出された。また、元素分析結果は、炭素、窒素、酸素が主な構成元素であり、検出濃度は、炭素８１．１０重量％、窒素６．３０重量％、酸素１２．１０重量％であった。なお、上記以外の元素として、水素０．５０重量％、ケイ素は１重量％の検出限界以下であった。   In order to investigate the degree of crystallinity of the above particles, a peak analysis that appeared at 2θ = 25.8 ° in XRD measurement was performed. As a result, the peak half-value width was 4.25 ° and the distance between crystallites was 3.45 mm. And calculated. The elemental analysis results showed that carbon, nitrogen and oxygen were the main constituent elements, and the detected concentrations were 81.10% by weight of carbon, 6.30% by weight of nitrogen and 12.10% by weight of oxygen. As elements other than the above, hydrogen was 0.50% by weight, and silicon was 1% by weight or less.

実施例４：
先ず、次の要領でアクリロニトリルとアクリル酸メチルの共重合ポリマー微粒子を合成した。すなわち、ドデシル硫酸ナトリウム０．３２ｇを水１４５ｇに溶解し、ここにアクリロニトリル１４．２５ｇ、アクリル酸メチル０．６ｇ、メタアクリル酸０．１５ｇ、ｎ−ブチルメルカプタン０．１５ｇ、ポリビニルアルコール（クラレ（株）社製「ＰＶＡ１１７」）の混合物を加え、窒素ガスのフロー下で３００ｒｐｍで撹拌しながら、室温から昇温し、６０℃で過硫酸カリウム水溶液（０．１ｇを水５ｇで溶解した水溶液）を加えて重合を開始し、７０℃で３時間重合した。反応停止後、水を除去し、平均粒径１１７ｎｍ（前述の動的光散乱式の粒度分布測定器での測定値）のアクリル樹脂粒子１０．３ｇを含む懸濁液を調製した。この樹脂粒子の元素分析（Ｃ、Ｈ、Ｎ）による窒素量から換算されるアクリロニトリル単位の割合は９４．５重量％であった。 Example 4:
First, copolymer fine particles of acrylonitrile and methyl acrylate were synthesized in the following manner. That is, 0.32 g of sodium dodecyl sulfate was dissolved in 145 g of water, and 14.25 g of acrylonitrile, 0.6 g of methyl acrylate, 0.15 g of methacrylic acid, 0.15 g of n-butyl mercaptan, polyvinyl alcohol (Kuraray Co., Ltd.) ) "PVA117" manufactured by the company) was added, the temperature was raised from room temperature while stirring at 300 rpm under a flow of nitrogen gas, and an aqueous potassium persulfate solution (an aqueous solution in which 0.1 g was dissolved in 5 g of water) was added at 60 ° C. In addition, polymerization was started, and polymerization was performed at 70 ° C. for 3 hours. After the reaction was stopped, water was removed to prepare a suspension containing 10.3 g of acrylic resin particles having an average particle size of 117 nm (measured with the above-mentioned dynamic light scattering type particle size distribution analyzer). The ratio of acrylonitrile units calculated from the amount of nitrogen by elemental analysis (C, H, N) of the resin particles was 94.5% by weight.

次いで、ケイ酸ナトリウム３重量％水溶液１２ｇと上記のアクリル粒子エマルジョン１ｇ（ポリマー粒子量０．０７１ｇ）を混合した後、塩酸でH型にした陽イオン交換樹脂（三菱化学社製「ＳＫ１Ｂ」）３ｍｌを入れスターラーで攪拌し、ｐHが３．０になるまでイオン交換を行った。その後、８ｃｍ径のテフロン（登録商標）製シャーレに展開し、６０℃に設定したホットプレート上で２時間加熱乾燥してゲル化させ、更に、そのまま１９時間加熱して乾燥させ、ポリマー粒子が分散したシリカゲルを得た。このゲルをガラス皿に移し、室温で１０時間減圧乾燥した。   Next, after mixing 12 g of a 3 wt% aqueous solution of sodium silicate and 1 g of the above acrylic particle emulsion (polymer particle amount 0.071 g), 3 ml of a cation exchange resin (“SK1B” manufactured by Mitsubishi Chemical Co., Ltd.) made into H type with hydrochloric acid. The mixture was stirred with a stirrer and ion exchange was performed until the pH reached 3.0. After that, it is developed on an 8 cm diameter Teflon (registered trademark) petri dish, heated and dried on a hot plate set at 60 ° C. for 2 hours to be gelled, and further heated and dried for 19 hours to disperse the polymer particles. Silica gel was obtained. This gel was transferred to a glass dish and dried under reduced pressure at room temperature for 10 hours.

上記で得られた乾燥ゲルを空気中で、２２０℃にて１６時間不融化反応を行った後、電気炉により常圧下、窒素雰囲気のフロー系で、室温から５℃／分で１０００℃まで昇温し、１０００℃で１時間保持してポリマー粒子を炭素化した。その後、加熱を停止し、電気炉が室温にまで冷却された１２時間後に試料を取り出した。これを１ｍｏｌ／Ｌの水酸化ナトリウム水溶液３０ｍｌに混合し、耐圧容器に入れ、オーブン中１７０℃で６時間加熱してシリカゲルを溶解し、炭素化粒子が分散した分散液を得た。この分散液を１８０００ｒｐｍの条件で遠心分離し、上澄み液を除去し、更に、沈殿の炭素化粒子を同様の方法で３回水洗し、炭素粒子の分散液を得た。   The dried gel obtained above was subjected to an infusibilization reaction in air at 220 ° C. for 16 hours, and then increased from room temperature to 1000 ° C. at a rate of 5 ° C./min in a nitrogen atmosphere flow system using an electric furnace. The polymer particles were carbonized by warming and holding at 1000 ° C. for 1 hour. Thereafter, heating was stopped, and a sample was taken out 12 hours after the electric furnace was cooled to room temperature. This was mixed with 30 ml of a 1 mol / L sodium hydroxide aqueous solution, placed in a pressure vessel, heated in an oven at 170 ° C. for 6 hours to dissolve the silica gel, and a dispersion in which carbonized particles were dispersed was obtained. This dispersion was centrifuged at 18000 rpm, the supernatant was removed, and the precipitated carbonized particles were washed with water three times in the same manner to obtain a dispersion of carbon particles.

上記の分散液を超音波にて３分間分散し、その中から無作為に３滴をガラス板に採り、光学顕微鏡（倍率：１００倍）で観察したところ、何れの滴にも１００μｍ以上の炭素粒子およびその凝集物は観察されなかった。   The above dispersion was dispersed with an ultrasonic wave for 3 minutes, and 3 drops were randomly picked from a glass plate and observed with an optical microscope (magnification: 100 times). Particles and their aggregates were not observed.

上記の分散液中の粒子の構造を透過型電子顕微鏡（ＴＥＭ）で観察した（倍率：８０万倍）。その結果、本実施例で得られた分散液中の粒子は、内部に２種類の形態の独立した空間部を有し、粒径が９５〜１１０ｎｍであり、アスペクト比が１の球状炭素粒子であった。１つの空間部は炭素結晶壁で包囲された完全な形の空間部（中空部）であり、他の空間部は炭素結晶壁の一部が欠落して開口部を有し、内部空間部が外部と導通している空間部であった。従って、図１（ｃ）に示す様に形態に関して内部空間部が外部と導通した構造であることが確認された。また、この球状炭素粒子を８万倍で観察したところ、凝集体は視野に存在しなかった。   The structure of the particles in the dispersion was observed with a transmission electron microscope (TEM) (magnification: 800,000 times). As a result, the particles in the dispersion obtained in this example are spherical carbon particles having internal space with two different forms, a particle size of 95 to 110 nm, and an aspect ratio of 1. there were. One space part is a completely shaped space part (hollow part) surrounded by a carbon crystal wall, and the other space part has a part of the carbon crystal wall missing and an opening, and the internal space part is It was a space that is connected to the outside. Accordingly, as shown in FIG. 1 (c), it was confirmed that the internal space portion was electrically connected to the outside with respect to the form. Further, when the spherical carbon particles were observed at a magnification of 80,000, no aggregates were present in the visual field.

動的光散乱式の粒度分布測定器（ハネウエル社製「ＭｉｃｒｏｓｏｆｔＵＳＡモデル：９３０−ＵＳＡ」）により、上記の粒子の水に対する分散状態を測定したところ、分布中心の粒径が１４５ｎｍ、１０％体積分布の粒径が１００ｎｍ、９０％個数分布の粒径が２７５ｎｍ、粒径分布指標が１．２０７の値を持つ粒径分布であった。更に、平均的粒子１０個について画像処理を行い、その半径比を算出したところ、各々、１．２８、１．３６、１．２２、１．１５、１．１１、１．０１、１．１８、１．０５、１．３１、１．２９であった。すなわち、半径比が１．０〜１．３の範囲である球状炭素粒子の割合は９０個数％であった。   When the dispersion state of the above particles in water was measured with a dynamic light scattering type particle size distribution analyzer (“Microsoft USA model: 930-USA” manufactured by Honeywell), the particle size at the center of distribution was 145 nm, and 10% volume distribution. The particle size distribution was 100 nm, the 90% number distribution particle size was 275 nm, and the particle size distribution index was 1.207. Further, image processing was performed on 10 average particles, and the radius ratio was calculated, and 1.28, 1.36, 1.22, 1.15, 1.11, 1.01, 1.18, respectively. 1.05, 1.31, and 1.29. That is, the ratio of spherical carbon particles having a radius ratio in the range of 1.0 to 1.3 was 90% by number.

上記の粒子の結晶化度を調べるため、ＸＲＤ測定における２θ＝２５．８°に現れたピーク解析を行なったところ、ピーク半値幅は４．２５°で、結晶子の面間距離は３．４５Åと算出された。また、元素分析結果は、炭素、窒素、酸素が主な構成元素であり、検出濃度は、炭素８１．１０重量％、窒素６．３０重量％、酸素１２．１０重量％であった。なお、上記以外の元素として、水素０．５０重量％、ケイ素は１重量％の検出限界以下であった。   In order to investigate the degree of crystallinity of the above particles, a peak analysis that appeared at 2θ = 25.8 ° in XRD measurement was performed. As a result, the peak half-value width was 4.25 ° and the distance between crystallites was 3.45 mm. And calculated. The elemental analysis results showed that carbon, nitrogen and oxygen were the main constituent elements, and the detected concentrations were 81.10% by weight of carbon, 6.30% by weight of nitrogen and 12.10% by weight of oxygen. As elements other than the above, hydrogen was 0.50% by weight, and silicon was 1% by weight or less.

比較例１：
実施例１と同様に調製した延伸されたアクリル粒子のエマルジョン１２．８ｇ（ポリマー粒子量０．１ｇ）をシリカゲルに分散させずに、２４時間静置乾燥し後、実施例１と同様に炭素化を行った。以降、実施例１と同様の手順と条件で炭素化物の分散液を得た。 Comparative Example 1:
An emulsion of stretched acrylic particles prepared in the same manner as in Example 1 (polymer particle amount 0.1 g) was left to dry for 24 hours without being dispersed in silica gel, and then carbonized in the same manner as in Example 1. Went. Thereafter, a carbonized dispersion was obtained in the same procedure and conditions as in Example 1.

上記の分散液中の粒子の構造をＴＥＭ（倍率：８万倍）で観察したところ、形状および大きさとも様々であり、炭素結晶構造が確認できない粒子とその凝集体の群であった。特に、粒子の空洞部は確認されなかった。   When the structure of the particles in the dispersion was observed with a TEM (magnification: 80,000 times), it was a group of particles and aggregates of which the shape and size varied and the carbon crystal structure could not be confirmed. In particular, no particle cavity was observed.

上記の分散液中の粒子２０mｇを水１０ｍｌに混合し、超音波にて３分間分散し、その中から任意の１滴をガラス板に採り、光学顕微鏡（倍率：１００倍）で観察したところ、１００μｍ以上の炭素粒子が多数観察された。   When 20 mg of the particles in the above dispersion were mixed with 10 ml of water and dispersed with ultrasonic waves for 3 minutes, one arbitrary drop was taken on a glass plate and observed with an optical microscope (magnification: 100 times). Many carbon particles of 100 μm or more were observed.

また、上記の粒子の結晶化度をＸＲＤ測定における２θ＝２３．３°に現れたピーク解析で行ったところ、ピーク半値幅は９．０°で結晶子の面間距離は３．８１Åと算出された。   Further, when the crystallinity of the above-mentioned particles was analyzed by peak analysis that appeared at 2θ = 23.3 ° in XRD measurement, the peak half-value width was 9.0 ° and the distance between crystallites was calculated to be 3.81 mm. It was done.

実施例５：
アクリロニトリルとアクリル酸メチルの共重合ポリマー微粒子は実施例２で作製した粒子をそのまま使用した。一方、水３．８７ｇとエタノール４．９４ｇの混合液にメチルシリケートオリゴマー（三菱化学製「ＭＳ５１」）５．５９ｇを混合して分散した後、１ｍｏｌ／Ｌの塩酸を混合し、ｐＨ４の液を調製した。５０℃で１時間撹拌し、メチルシシリケートオリゴマーを加水分解し、均一な溶液としてシリカゾルを調製した。 Example 5:
The particles prepared in Example 2 were used as they were as copolymer fine particles of acrylonitrile and methyl acrylate. On the other hand, 5.59 g of a methyl silicate oligomer (“MS51” manufactured by Mitsubishi Chemical Corporation) was mixed and dispersed in a mixed liquid of 3.87 g of water and 4.94 g of ethanol, and then 1 mol / L hydrochloric acid was mixed to obtain a pH 4 solution. Prepared. The mixture was stirred at 50 ° C. for 1 hour to hydrolyze the methyl silicate oligomer to prepare a silica sol as a uniform solution.

次いで、上記のアクリル粒子のエマルジョン０．５２ｇ（ポリマー粒子量０．０４３ｇ）に上記のシリカゾル１．５８ｇを加え、振とうして混合した後、密栓して３日間静置してポリマー粒子が分散したシリカゲルを得た。このゲルをガラス皿に移し、室温で１０時間減圧乾燥した。   Next, 1.58 g of the above silica sol is added to 0.52 g of the above acrylic particle emulsion (polymer particle amount 0.043 g), and the mixture is shaken and mixed, and then sealed and left to stand for 3 days to disperse the polymer particles. Silica gel was obtained. This gel was transferred to a glass dish and dried under reduced pressure at room temperature for 10 hours.

上記で得られた乾燥ゲルを、空気中で、２２０℃、１６時間不融化反応を行った後、
電気炉にて常圧下に窒素雰囲気でのフロー系で室温から５℃／分で１０００℃まで昇温し、１０００℃で１時間保持してポリマー粒子を炭素化した。その後、加熱を停止し、電気炉が室温にまで冷却された１２時間後に試料を取り出した。これを、１ｍｏｌ／Ｌの水酸化ナトリウム水溶液３０ｍｌに混合し、耐圧容器に入れ、オーブン中１７０℃で６時間加熱してシリカゲルを溶解し、炭素化粒子が分散した分散液を得た。この分散液を１８０００ｒｐｍの条件で遠心分離し、上澄み液を除去し、更に、沈殿の炭素化粒子を同様の方法で３回水洗し、炭素粒子の分散液を得た。 After performing the infusibilization reaction at 220 ° C. for 16 hours in the air, the dried gel obtained above was
The temperature was raised from room temperature to 1000 ° C. at 5 ° C./min in a flow system in a nitrogen atmosphere under normal pressure in an electric furnace, and the polymer particles were carbonized by holding at 1000 ° C. for 1 hour. Thereafter, heating was stopped, and a sample was taken out 12 hours after the electric furnace was cooled to room temperature. This was mixed with 30 ml of a 1 mol / L aqueous sodium hydroxide solution, placed in a pressure vessel, heated in an oven at 170 ° C. for 6 hours to dissolve the silica gel, and a dispersion in which carbonized particles were dispersed was obtained. This dispersion was centrifuged at 18000 rpm, the supernatant was removed, and the precipitated carbonized particles were washed with water three times in the same manner to obtain a dispersion of carbon particles.

上記の分散液を超音波にて３分間分散し、その中から任意の３滴をガラス板に採り、光学顕微鏡（倍率：１００倍）で観察したところ、何れの滴にも１００μｍ以上の炭素粒子およびその凝集物は観察されなかった。   The above dispersion was dispersed for 3 minutes with ultrasonic waves, and any 3 drops were taken on a glass plate and observed with an optical microscope (magnification: 100 times). And no aggregates were observed.

上記の分散液中の粒子の構造を透過型電子顕微鏡（ＴＥＭ）（倍率：８万倍）で観察したところ、粒径１１５〜１３５ｎｍの球状粒子であった。また、壁の厚さは６〜３０ｎｍであった。結晶壁厚みの粒子半径に対する比は１４．４％であり、中空による粒子内の空間容積は充分に大きいものであった。   When the structure of the particles in the dispersion was observed with a transmission electron microscope (TEM) (magnification: 80,000 times), it was spherical particles having a particle diameter of 115 to 135 nm. The wall thickness was 6 to 30 nm. The ratio of the crystal wall thickness to the particle radius was 14.4%, and the space volume in the particles due to the hollow was sufficiently large.

また、透過型電子顕微鏡（ＴＥＭ）（倍率：８０万倍）で観察したところ、粒子内部に炭素結晶壁で包囲された中空部を１つ有し、アスペクト比が１の球状炭素粒子であった。この中空炭素粒子は、同心円方向に炭素結晶が積層した構造を備えていた。従って、図１（ｂ）に示す様に半径方向に結晶が積層した構造であることが確認された。   Further, when observed with a transmission electron microscope (TEM) (magnification: 800,000 times), it was a spherical carbon particle having one hollow portion surrounded by a carbon crystal wall inside the particle and having an aspect ratio of 1. . The hollow carbon particles had a structure in which carbon crystals were stacked in a concentric direction. Therefore, as shown in FIG. 1B, it was confirmed that the crystal was laminated in the radial direction.

また、凝集体は視野に存在しなかった。更に、平均的粒子１０個について画像処理を行い、その半径比を算出したところ、各々、１．０５、１．１２、１．１５、１．１７、１．１９、１．１９、１．２０、１．３７、１．３９、１．６１であった。すなわち、半径比が１．０〜１．３の範囲である球状炭素粒子の割合は７０個数％であった。   Moreover, the aggregate did not exist in the visual field. Further, image processing was performed on 10 average particles, and the radius ratios were calculated. As a result, 1.05, 1.12, 1.15, 1.17, 1.19, 1.19, 1.20 were obtained. 1.37, 1.39, 1.61. That is, the ratio of spherical carbon particles having a radius ratio in the range of 1.0 to 1.3 was 70% by number.

動的光散乱式の粒度分布測定器（ハネウエル社製「ＭｉｃｒｏｔｒａｃＵＳＡモデル：９３０−ＵＰＡ」）により、上記の粒子の水に対する分散状態を測定したところ、５０％体積分布粒径が１２８ｎｍ、１０％体積分布の粒径が２５ｎｍ、９０％体積分布の粒径が２５４ｎｍ、粒径分布指標が１．７９値を持つ粒径分布であった。   When the dispersion state of the above-mentioned particles in water was measured with a dynamic light scattering particle size distribution analyzer (“Microtrac USA model: 930-UPA” manufactured by Honeywell), the 50% volume distribution particle size was 128 nm, 10% volume. The particle size distribution was 25 nm, the 90% volume distribution was 254 nm, and the particle size distribution index was 1.79.

上記の粒子の結晶化度をＸＲＤ測定における２θ＝２５．７°に現れたピーク解析で行ったところ、ピーク半値幅は４．５３°で結晶子の面間距離は３．４７Åと算出された。また、元素分析結果は、炭素、窒素、酸素が主な構成元素であり、検出濃度は、炭素８６．２０重量％、窒素７．２１重量％、酸素６．２７重量％であった。なお、上記以外の元素として、水素０．３２重量％、ケイ素は１重量％の検出限界以下であった。   When the crystallinity of the particles was analyzed by peak analysis at 2θ = 25.7 ° in XRD measurement, the peak half-value width was 4.53 ° and the distance between crystallites was calculated to be 3.47 mm. . The elemental analysis results showed that carbon, nitrogen and oxygen were the main constituent elements, and the detected concentrations were 86.20 wt% carbon, 7.21 wt% nitrogen and 6.27 wt% oxygen. In addition, as elements other than the above, hydrogen was 0.32% by weight and silicon was 1% by weight or less.

Ｘ線光電子分光法にて本実施例の炭素粒子の表面官能基の分析を行い、ピーク分離によりＣ−ＯＨ，Ｃ＝Ｏ，ＣＯＯＲのピークを確認した。また、フーリエ変換赤外分光法（拡散反射法を使用）による測定で３４００ｃｍ−１付近にＯＨH伸縮振動が観察され、ＯＨ基の存在が確認された。 The surface functional groups of the carbon particles of this example were analyzed by X-ray photoelectron spectroscopy, and C—OH, C═O, and COOR peaks were confirmed by peak separation. Further, OHH stretching vibration was observed in the vicinity of 3400 cm −1 as measured by Fourier transform infrared spectroscopy (using diffuse reflection method), and the presence of OH groups was confirmed.

炭素結晶の方向が異なる炭素粒子の一例を示す模式図Schematic diagram showing an example of carbon particles with different carbon crystal orientations 炭素結晶端が露出した構造および炭素網面のループ状構造の一例の模式図Schematic diagram of an example of a structure with an exposed carbon crystal edge and a loop structure of a carbon network surface 実施例３で得られた球状炭素粒子の説明図（図面代用写真）Explanatory drawing of the spherical carbon particle obtained in Example 3 (drawing substitute photograph)

符号の説明Explanation of symbols

１：炭素結晶壁
２：空間部
３：炭素結晶の方向（炭素網面の積層方向）
ａ：炭素網面の粒子表面側末端が閉じていない構造
ｂ：炭素網面の粒子表面側の末端同士が結合している構造 1: Carbon crystal wall 2: Space part 3: Direction of carbon crystal (stacking direction of carbon network surface)
a: Structure in which the ends on the particle surface side of the carbon network surface are not closed b: Structure in which the ends on the particle surface side of the carbon network surface are bonded to each other

Claims (7)

粒径が５ｎｍ以上１００μｍ以下の粒子であり炭素結晶の結晶壁で包囲された空間部を有する構造の球状炭素粒子の集合体であって、半径比が１．０〜１．３の範囲である球状炭素粒子の割合が４０個数％以上であることを特徴とする球状炭素粒子の集合体。   An aggregate of spherical carbon particles having a particle size of 5 nm or more and 100 μm or less and having a space part surrounded by a crystal wall of a carbon crystal and having a radius ratio of 1.0 to 1.3 An aggregate of spherical carbon particles, wherein the proportion of spherical carbon particles is 40% by number or more. 球状炭素粒子の集合体であって、以下の方法で調製された分散液について、調製後２４時間静置して測定した以下の式（Ｉ）で表される粒径分布指標が０．１〜２０であることを特徴とする球状炭素粒子の集合体。
＜分散液の調製＞
内径１３ｍｍ、容量５ｍｌのガラス容器に分散媒３ｍｌと試料１ｍｇを採り、蓋を被せ、超音波振盪器を使用し、高周波出力１２０Ｗ、発振周波数３８ｋＨｚの条件下に１分間振とうさせて試料を分散させる。
A dispersion of spherical carbon particles having a particle size distribution index represented by the following formula (I) of 0.1 to 0.1 measured by standing for 24 hours after preparation for a dispersion prepared by the following method: An aggregate of spherical carbon particles characterized by being 20.
<Preparation of dispersion>
Place 3 ml of dispersion medium and 1 mg of sample in a glass container with an inner diameter of 13 mm and a capacity of 5 ml, cover the sample, and use an ultrasonic shaker to shake the sample for 1 minute under conditions of high frequency output of 120 W and oscillation frequency of 38 kHz. Let
球状炭素粒子の集合体が請求項１に記載の球状炭素粒子の集合体である請求項２に記載の球状炭素粒子の集合体。   The aggregate of spherical carbon particles according to claim 2, wherein the aggregate of spherical carbon particles is an aggregate of spherical carbon particles according to claim 1. 粒径が５ｎｍから１００μｍの範囲から選択される前駆体球状粒子を原料とし、当該原料をその形状を維持するように原形型で被覆した状態で炭素化することを特徴とする球状炭素粒子の製造方法。   Production of spherical carbon particles characterized in that precursor spherical particles having a particle size selected from a range of 5 nm to 100 μm are used as raw materials, and the raw materials are carbonized in a state of being covered with a prototype so as to maintain the shape. Method. 前駆体球状粒子が液相炭素化可能材料または易分解性ポリマー含有物質である請求項４に記載の製造方法。   The production method according to claim 4, wherein the precursor spherical particles are a liquid phase carbonizable material or an easily decomposable polymer-containing substance. 分散媒中に請求項１に記載の球状炭素粒子の集合体を分散して成ることを特徴とする球状炭素粒子の分散体。   A dispersion of spherical carbon particles, wherein the spherical carbon particle aggregate according to claim 1 is dispersed in a dispersion medium. 分散媒中に請求項２に記載の球状炭素粒子の集合体を分散して成ることを特徴とする球状炭素粒子の分散体。   A dispersion of spherical carbon particles, wherein the aggregate of spherical carbon particles according to claim 2 is dispersed in a dispersion medium.
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JP2014196239A (en) * 2014-04-02 2014-10-16 旭化成ケミカルズ株式会社 Nitrogen-containing carbon material
JP2015059058A (en) * 2013-09-18 2015-03-30 株式会社ノリタケカンパニーリミテド Porous carbon particle, and production method thereof
JP2019112270A (en) * 2017-12-25 2019-07-11 住友ベークライト株式会社 Functional filler, granulation filler, carbonization filler, resin composition, molded product, and method for producing the functional filler

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JPH067670A (en) * 1990-06-20 1994-01-18 Japan Synthetic Rubber Co Ltd Composite particle, hollow particle and method for production thereof
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JPS5029837B2 (en) * 1971-09-01 1975-09-26
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JPH067670A (en) * 1990-06-20 1994-01-18 Japan Synthetic Rubber Co Ltd Composite particle, hollow particle and method for production thereof
JPH10182118A (en) * 1996-10-16 1998-07-07 Toyo Tanso Kk Carbon material and its production
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* Cited by examiner, † Cited by third party
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JP2015059058A (en) * 2013-09-18 2015-03-30 株式会社ノリタケカンパニーリミテド Porous carbon particle, and production method thereof
JP2014196239A (en) * 2014-04-02 2014-10-16 旭化成ケミカルズ株式会社 Nitrogen-containing carbon material
JP2019112270A (en) * 2017-12-25 2019-07-11 住友ベークライト株式会社 Functional filler, granulation filler, carbonization filler, resin composition, molded product, and method for producing the functional filler

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