JP6979196B2 - Method for exfoliating layered mineral powder and method for producing layered nanoplate complex - Google Patents
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Description
本発明は、層状鉱物粉体の剥離方法および層状ナノプレート複合体の製造方法に関する。 The present invention relates to a method for exfoliating a layered mineral powder and a method for producing a layered nanoplate complex.
グラフェンに代表される層状ナノプレートは、熱伝導性や導電性等を有する機能性接着剤、機能性コーティング膜、機能性プリンタブルインクをはじめとする機能性材料・電子材料への応用が期待されている。 Layered nanoplates represented by graphene are expected to be applied to functional materials and electronic materials such as functional adhesives having thermal conductivity and conductivity, functional coating films, and functional printable inks. There is.
グラフェンの製造方法として、グラファイトに対し、テープを用いて剥離する方法が知られている。また、グラファイトを硝酸や硫酸などで激しく酸化させて酸化グラフェンを合成し、その後に水熱合成を行い、エポキシ鎖を開裂することでグラフェンを微細化する方法が開示されている（非特許文献１）。また、９，９−ビス（置換アリール）フルオレン骨格を有する水溶性化合物と酸化グラフェンとを含む酸化グラフェン水分散体を用いて、グラフェンシート有機分散体を得、グラフェンシート水分散体と有機溶媒とを混合した後、グラフェンシートを遠心沈降させて回収する工程等を経てグラフェンシート有機分散体を得る方法が開示されている（特許文献１）。また、特定のイオン液体にグラファイトを添加し、マイクロ波等を照射してグラフェン分散液を製造する方法が提案されている（特許文献２）。 As a method for producing graphene, a method of peeling graphite with a tape is known. Further, a method is disclosed in which graphite is violently oxidized with nitric acid or sulfuric acid to synthesize graphene oxide, and then hydrothermal synthesis is performed to cleave the epoxy chain to make graphene finer (Non-Patent Document 1). ). Further, a graphene sheet organic dispersion was obtained using a graphene oxide aqueous dispersion containing a water-soluble compound having a 9,9-bis (substituted aryl) fluorene skeleton and graphene oxide, and the graphene sheet aqueous dispersion and an organic solvent were used. Disclosed is a method for obtaining an organic dispersion of graphene sheet through a step of centrifuging and recovering the graphene sheet after mixing the graphene sheets (Patent Document 1). Further, a method of adding graphite to a specific ionic liquid and irradiating it with microwaves or the like to produce a graphene dispersion has been proposed (Patent Document 2).
また、ＮＭＰ、ＤＭＦ又はＤＭＳＯ中に塩を加え、高せん断、超音波処理を施すことでグラフェンを製造する方法（非特許文献２）、塩を黒鉛の層間に挿入し、その層間化合物をピリジン中で超音波照射し、グラフェンを製造する方法（非特許文献３）が提案されている。また、活性メチレン化合物誘導体と塩基性化合物を含む液体にグラフェン積層構造を有する炭素材料を浸漬させ、撹拌することにより薄片化黒鉛を得る方法（特許文献３）、黒鉛とポリ芳香族炭化水素化合物を分散させた分散液を用いてフレーク化されたグラフェンを得る方法（特許文献４）も提案されている。 Further, a method for producing graphene by adding a salt to NMP, DMF or DMSO and subjecting it to high shear and ultrasonic treatment (Non-Patent Document 2), the salt is inserted between graphite layers and the interlayer compound is contained in pyridine. A method of producing graphene by irradiating with ultrasonic waves (Non-Patent Document 3) has been proposed. Further, a method for obtaining flaky graphite by immersing a carbon material having a graphene laminated structure in a liquid containing an active methylene compound derivative and a basic compound and stirring the mixture (Patent Document 3), graphite and a polyaromatic hydrocarbon compound. A method for obtaining flaky graphene using a dispersed dispersion (Patent Document 4) has also been proposed.
なお、層状鉱物ではないが、カーボンナノチューブの分散性を向上させる方法として、有機溶媒と塩を用いる方法が提案されている（特許文献５）。 Although it is not a layered mineral, a method using an organic solvent and a salt has been proposed as a method for improving the dispersibility of carbon nanotubes (Patent Document 5).
市場では、様々な用途への応用展開を実現するために、分散性が高く、且つより生産性の高いグラフェンの製造方法が切望されている。なお、上記においては、グラフェンにおける課題について述べたが、層状ナノプレート全般において同様の課題を有する。 In the market, a method for producing graphene with high dispersibility and higher productivity is eagerly desired in order to realize application development to various applications. In the above, the problems in graphene have been described, but the same problems are present in the layered nanoplates in general.
本発明は、上記背景に鑑みて成されたものであり、生産性に優れ、且つ分散性に優れる層状鉱物粉体の剥離方法、および層状ナノプレート複合体の製造方法を提供することを課題とする。 The present invention has been made in view of the above background, and an object of the present invention is to provide a method for exfoliating a layered mineral powder having excellent productivity and excellent dispersibility, and a method for producing a layered nanoplate composite. do.
本発明者らが鋭意検討を重ねたところ、以下の態様において、本発明の課題を解決し得ることを見出し、本発明を完成するに至った。 As a result of diligent studies by the present inventors, they have found that the problems of the present invention can be solved in the following aspects, and have completed the present invention.
［１］： 層状鉱物粉体を層状に剥離する方法であって、
有機溶媒中に、層状鉱物粉体と前記有機溶媒に分散する塩とを加える添加工程と、得られた混合液を撹拌する混合工程とを含み、
前記有機溶媒は、以下の数式（１）および数式（２）を満たし、
前記塩は、当該塩の対アニオンの酸の酸解離定数ｐＫａ（Ｈ２Ｏ）が０より大きい塩である、層状鉱物粉体の剥離方法。
［数式（１）］
４≦有機溶媒１の体積比率×有機溶媒１の比誘電率＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の比誘電率≦６０
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。
［数式（２）］
有機溶媒１の体積比率×有機溶媒１の沸点＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の沸点＜１００℃
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。
上記層状鉱物粉体の剥離方法によれば、簡便且つ短時間に剥離を行うことができるので、生産性を高めることができる。また、塩を加えることにより分散性を顕著に高めることができる。
[1]: A method for exfoliating layered mineral powder into layers.
It comprises an addition step of adding a layered mineral powder and a salt dispersed in the organic solvent into an organic solvent, and a mixing step of stirring the obtained mixed solution.
The organic solvent satisfies the following mathematical formulas (1) and (2).
A method for exfoliating a layered mineral powder, wherein the salt is a salt in which the acid dissociation constant pKa (H 2 O) of the acid of the counter anion of the salt is larger than 0.
[Formula (1)]
4 ≤ Volume ratio of organic solvent 1 x Relative permittivity of
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
[Formula (2)]
Volume ratio of organic solvent 1 x boiling point of
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
According to the layered mineral powder peeling method, the peeling can be performed easily and in a short time, so that the productivity can be improved. Moreover, the dispersibility can be remarkably enhanced by adding a salt.
［２］： 有機溶媒中に、層状鉱物粉体と前記有機溶媒に分散する塩とを加える添加工程と、
得られた混合液を撹拌する混合工程とを含み、
前記有機溶媒は、以下の数式（１）および数式（２）を満たし、
前記塩は、当該塩の対アニオンの酸の酸解離定数ｐＫａ（Ｈ２Ｏ）が０より大きい塩である、層状ナノプレート複合体の製造方法。
［数式（１）］
４≦有機溶媒１の体積比率×有機溶媒１の比誘電率＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の比誘電率≦６０
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。
［数式（２）］
有機溶媒１の体積比率×有機溶媒１の沸点＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の沸点＜１００℃
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。
上記層状ナノプレート複合体の製造方法によれば、有機溶媒中に塩を加えることにより分散性を顕著に高めることができる。この反応は、常温・常圧において行うことができるので、また、短時間で分散性を高められるので、生産性に優れる。
[2]: An addition step of adding a layered mineral powder and a salt dispersed in the organic solvent to the organic solvent.
Including a mixing step of stirring the obtained mixed liquid,
The organic solvent satisfies the following mathematical formulas (1) and (2).
A method for producing a layered nanoplate complex, wherein the salt is a salt in which the acid dissociation constant pKa (H 2 O) of the acid of the counter anion of the salt is larger than 0.
[Formula (1)]
4 ≤ Volume ratio of organic solvent 1 x Relative permittivity of
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
[Formula (2)]
Volume ratio of organic solvent 1 x boiling point of
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
According to the method for producing a layered nanoplate complex, the dispersibility can be remarkably enhanced by adding a salt to an organic solvent. Since this reaction can be carried out at normal temperature and pressure, and the dispersibility can be improved in a short time, the productivity is excellent.
［３］： 前記混合工程後、濾別により濾取する濾取工程と、
前記濾取工程後、溶媒に再分散させ、サイズ分画する工程を含む［２］に記載の層状ナノプレート複合体の製造方法。
上記製造方法によれば、サイズの揃った分散性に優れた層状ナノプレート複合体を簡便に得ることができる。
[3]: After the mixing step, a filtering step of filtering by filtration and a filtering step
The method for producing a layered nanoplate complex according to [2], which comprises a step of redispersing in a solvent and fractionating the size after the filtration step.
According to the above-mentioned production method, a layered nanoplate complex having a uniform size and excellent dispersibility can be easily obtained.
［４］： 前記濾取工程後に、前記有機溶媒を留去する工程をさらに備える［２］又は［３］に記載の層状ナノプレート複合体の製造方法。
上記製造方法によれば、層状ナノプレート複合体を容易に得ることができる。
[4]: The method for producing a layered nanoplate complex according to [2] or [3], further comprising a step of distilling off the organic solvent after the filtration step.
According to the above-mentioned production method, a layered nanoplate complex can be easily obtained.
［５］： 前記混合工程により、前記層状鉱物粉体が薄膜化されている［２］〜［４］のいずれかに記載の層状ナノプレート複合体の製造方法。 [5]: The method for producing a layered nanoplate complex according to any one of [2] to [4], wherein the layered mineral powder is thinned by the mixing step.
本発明によれば、生産性に優れ、且つ分散性に優れる層状鉱物粉体の剥離方法、および層状ナノプレート複合体の製造方法を提供できるという優れた効果を奏する。 According to the present invention, it is possible to provide an excellent method for exfoliating a layered mineral powder having excellent productivity and dispersibility, and a method for producing a layered nanoplate composite.
以下、本発明を適用した実施形態の一例について説明する。なお、本発明の趣旨に合致する限り、他の実施形態も本発明の範疇に含まれることは言うまでもない。 Hereinafter, an example of an embodiment to which the present invention is applied will be described. Needless to say, other embodiments are also included in the scope of the present invention as long as they are in line with the gist of the present invention.
［層状鉱物粉体の剥離方法］
本実施形態に係る層状鉱物粉体の剥離方法は、層状鉱物粉体を剥離して元の層状鉱物粉体よりも薄層化する方法に関する。本実施形態に係る層状鉱物粉体の剥離方法は、少なくとも有機溶媒中で層状鉱物粉体と有機溶媒に分散する塩とを加える添加工程と、塩と層状鉱物粉体を有機溶媒中で混合する混合工程とを含む。ここで「有機溶媒に分散する塩」とは、実質的に溶解は含まず、懸濁する意である。但し、懸濁が支配的であればよく、一部の塩が有機溶媒に溶解していてもよい。なお、分散には、塩および層状鉱物粉体がそれぞれ有機溶媒中に分散できればよく、撹拌等の物理的手段を用いて分散できるものも含む。添加工程と混合工程は同時または順に行うことができる。また、添加工程における塩と層状鉱物粉体の添加順は問わない。
[Peeling method of layered mineral powder]
The method for exfoliating the layered mineral powder according to the present embodiment relates to a method for exfoliating the layered mineral powder to make it thinner than the original layered mineral powder. The method for peeling the layered mineral powder according to the present embodiment is at least an addition step of adding the layered mineral powder and a salt dispersed in the organic solvent in an organic solvent, and mixing the salt and the layered mineral powder in the organic solvent. Includes a mixing step. Here, the "salt dispersed in an organic solvent" does not substantially contain dissolution and means to suspend. However, the suspension may be dominant, and some salts may be dissolved in an organic solvent. The dispersion may be such that the salt and the layered mineral powder can each be dispersed in an organic solvent, and includes those that can be dispersed by using physical means such as stirring. The addition step and the mixing step can be performed simultaneously or in sequence. Further, the order of addition of the salt and the layered mineral powder in the addition step does not matter.
（層状鉱物粉体）
本実施形態に係る層状鉱物粉体は、層状に積層された粉体状の層状鉱物をいう。原料として用いる「層状鉱物粉体」のサイズは、有機溶媒中で分散できるサイズであれば特に限定されず任意のサイズでよい。例えば、ミリオーダーの顆粒状の粉体、マイクロサイズまたはナノサイズの微粒子が例示できる。
(Layered mineral powder)
The layered mineral powder according to the present embodiment refers to a powdery layered mineral laminated in layers. The size of the "layered mineral powder" used as a raw material is not particularly limited as long as it can be dispersed in an organic solvent, and may be any size. For example, milliorder granular powder, micro-sized or nano-sized fine particles can be exemplified.
層状鉱物粉体の種類は特に限定されないが、窒化ホウ素、二硫化モリブデン、天然黒鉛、人造黒鉛、膨張化黒鉛、不定形黒鉛、板状型黒鉛、グラフェンナノプレート、グラフェン、二硫化タングステン、酸化グラフェン、酸化チタン、酸化マンガン、酸化バナジウム、層状腹水酸化物（ＬＤＨ）、遷移金属ダイカルコゲナイト、黒リンが例示できる。グラフェンには、多層グラフェン、単層グラフェンを含む。層状鉱物粉体は、公知の方法により製造したり、市販品を用いたりすることができる。層状鉱物粉体は１種単独で又は併用して用いられる。有機溶媒に対する層状鉱物粉体の添加量は分散に支障がない範囲であればよく限定されないが、好ましくは１０〜１００ｇ／Ｌである。 The type of layered mineral powder is not particularly limited, but is boron nitride, molybdenum disulfide, natural graphite, artificial graphite, expanded graphite, amorphous graphite, plate-shaped graphite, graphene nanoplate, graphene, tungsten disulfide, graphene oxide. , Titanium oxide, manganese oxide, vanadium oxide, layered ascites hydroxide (LDH), transition metal dicalcogenite, black phosphorus can be exemplified. Graphene includes multi-layer graphene and single-layer graphene. The layered mineral powder can be produced by a known method or a commercially available product can be used. The layered mineral powder is used alone or in combination. The amount of the layered mineral powder added to the organic solvent is not limited as long as it does not interfere with the dispersion, but is preferably 10 to 100 g / L.
（有機溶媒）
本実施形態に係る有機溶媒は、比誘電率が以下の数式（１）を満たすものを用いる。
［数式（１）］
４≦有機溶媒１の体積比率×有機溶媒１の比誘電率＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の比誘電率≦６０
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。
有機溶媒の種類は、１種単独の有機溶媒を用いても２種以上の混合溶媒で用いてもよい。１種単独の有機溶媒を用いる場合には、比誘電率が４以上、６０以下になる有機溶媒を用いる。複数の有機溶媒を混合する場合には、上記数式１に示す通り、全有機溶媒に対する各有機溶媒の体積比率と各有機溶媒の比誘電率の積の和が４以上、６０以下になるものを用いる。分散性向上の観点から、数式１のより好ましい範囲は１０以上、５０以下であり、更に好ましい範囲は２０以上、４０以下である。
(Organic solvent)
As the organic solvent according to this embodiment, a solvent having a relative permittivity satisfying the following mathematical formula (1) is used.
[Formula (1)]
4 ≤ Volume ratio of organic solvent 1 x Relative permittivity of organic solvent 1 + ... + Volume ratio of organic solvent n-1 x Relative permittivity of organic solvent n-1 ≤ 60
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
As the type of the organic solvent, one kind of organic solvent may be used alone, or two or more kinds of mixed solvents may be used. When a single organic solvent of one type is used, an organic solvent having a relative permittivity of 4 or more and 60 or less is used. When a plurality of organic solvents are mixed, the sum of the products of the volume ratio of each organic solvent to the total organic solvent and the relative permittivity of each organic solvent is 4 or more and 60 or less as shown in the
また、本実施形態の有機溶媒には、沸点が以下の数式（２）を満たすものを用いる。
［数式（２）］
有機溶媒１の体積比率×有機溶媒１の沸点＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の沸点＜１００℃
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。
１種単独で有機溶媒を用いる場合には、沸点が１００℃未満の有機溶媒を用いる。混合有機溶媒を用いる場合には、上記数式２に示す通り、全有機溶媒に対する各有機溶媒の体積比率と各有機溶媒の沸点の積の和が１００℃未満になるものを用いる。分散液の利用の観点から、数式２のより好ましい範囲は９０℃以下であり、さらに好ましい範囲は８０℃以下である。沸点の下限値は特にないが、常温で簡便に製造でき、取り扱い容易性の観点からは、常温（２３℃）で液体を示すものが好ましく、沸点が６０℃以上であることがより好ましい。
Further, as the organic solvent of the present embodiment, a solvent having a boiling point satisfying the following mathematical formula (2) is used.
[Formula (2)]
Volume ratio of organic solvent 1 x boiling point of organic solvent 1 + ... + volume ratio of organic solvent n-1 x boiling point of organic solvent n-1 <100 ° C.
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
When an organic solvent is used alone, an organic solvent having a boiling point of less than 100 ° C. is used. When a mixed organic solvent is used, as shown in the above formula 2, the sum of the volume ratio of each organic solvent to the total organic solvent and the product of the boiling points of each organic solvent is less than 100 ° C. From the viewpoint of utilization of the dispersion liquid, the more preferable range of the formula 2 is 90 ° C. or lower, and the more preferable range is 80 ° C. or lower. Although there is no particular lower limit for the boiling point, it is preferable that it is a liquid at room temperature (23 ° C), and it is more preferable that the boiling point is 60 ° C or higher, because it can be easily manufactured at room temperature and is easy to handle.
有機溶媒の比誘電率が上記数式（１）を満たすことにより、有機溶媒中で塩の解離を誘起することができる。塩の解離は部分的に起こっていればよく、その程度は問わないが、全て解離している状態は好ましくない。換言すると、塩が有機溶媒中で部分的に解離、或いはほとんど解離していない状態が好ましい。 When the relative permittivity of the organic solvent satisfies the above formula (1), dissociation of the salt can be induced in the organic solvent. The dissociation of the salt may be partial, and the degree of dissociation is not limited, but it is not preferable that the salt is completely dissociated. In other words, it is preferable that the salt is partially or hardly dissociated in the organic solvent.
有機溶媒の種類は上記数式（１）および数式（２）を満たせば特に限定されないが、単独で用いる場合の好適な溶媒として、アセトン、エタノール、メタノール、２−プロパノール、テトラヒドロフラン、メチルエチルケトン、アセトニトリル等が挙げられる。混合溶媒の場合には、前記有機溶媒に加えて、単独では上記数式（１）および／又は数式（２）を満たさない有機溶媒を併用することができる。係る混合に用いられる有機溶媒としては、例えば、ジメチルホルムアミド、ジメチルスルホキシド、Ｎ−メチルピロリドン（ＮＭＰ）、トルエン、キシレンが例示できる。分散液のポストプロセス性の観点からは、アセトン、エタノール、メタノール等の極性溶媒が好ましい。また、生産安定性の観点からは、１種単独の有機溶媒を用いることが好ましい。 The type of the organic solvent is not particularly limited as long as it satisfies the above formulas (1) and (2), but suitable solvents when used alone include acetone, ethanol, methanol, 2-propanol, tetrahydrofuran, methyl ethyl ketone, acetonitrile and the like. Can be mentioned. In the case of a mixed solvent, in addition to the organic solvent, an organic solvent that does not satisfy the above formula (1) and / or the above formula (2) can be used in combination. Examples of the organic solvent used for such mixing include dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone (NMP), toluene, and xylene. From the viewpoint of post-processability of the dispersion, polar solvents such as acetone, ethanol and methanol are preferable. Further, from the viewpoint of production stability, it is preferable to use one kind of organic solvent alone.
（塩）
本実施形態に係る塩は、有機溶媒中で層状鉱物粉体を剥離させる剥離剤として機能する。本実施形態に係る塩は、この塩を構成する対アニオンの酸の酸解離定数ｐＫａ（Ｈ２Ｏ）が０より大きい塩を用いる。好適な塩の対アニオンの酸として、リン酸（１．８３），酢酸（４．７６），炭酸（６．１１）が挙げられる。
(salt)
The salt according to this embodiment functions as a release agent for exfoliating the layered mineral powder in an organic solvent. As the salt according to the present embodiment, a salt having an acid dissociation constant pKa (H 2 O) of the acid of the counter anion constituting this salt is larger than 0 is used. Suitable salt counter-anionic acids include phosphoric acid (1.83), acetic acid (4.76) and carbonic acid (6.11).
前記アニオンと塩を形成する対カチオンの好ましい例としてカリウムイオン、ナトリウムイオン、アンモニウムイオンが例示できる。塩の濃度は特に限定されないが、層状鉱物粉体１００質量部あたり例えば０．０１〜１００質量部が好ましい。より好ましくは０．１〜１０質量部であり、更に好ましくは０．１〜１質量部である。また、有機溶媒に対する塩の添加量は特に限定されないが、好ましくは０．０５〜１０ｇ／Ｌである。 Preferred examples of the counter cation forming a salt with the anion include potassium ion, sodium ion, and ammonium ion. The concentration of the salt is not particularly limited, but is preferably 0.01 to 100 parts by mass per 100 parts by mass of the layered mineral powder. It is more preferably 0.1 to 10 parts by mass, and even more preferably 0.1 to 1 part by mass. The amount of the salt added to the organic solvent is not particularly limited, but is preferably 0.05 to 10 g / L.
有機溶媒に塩と層状鉱物粉体を加える添加工程を行う際の環境条件は特に限定されないが、常温、空気中で簡便に行うことができる。また、添加する順番は問わない。同時でもよいし、層状鉱物粉体の分散液に塩を加えてもよい。その後の混合工程は、公知の混合手段を制限なく用いることができる。例えば、攪拌機等の混合機を用いることができる。また、超音波照射、マイクロ波照射、高速ホモジナイザ（High Speed Homogenizer）、圧力式ホモジナイザ、ジェットミル、ボールミル、ビーズミル処理等が例示できる。混合工程において、加熱工程を併用してもよい。 The environmental conditions for adding the salt and the layered mineral powder to the organic solvent are not particularly limited, but can be easily carried out at room temperature and in the air. In addition, the order of addition does not matter. It may be done at the same time, or a salt may be added to the dispersion of the layered mineral powder. In the subsequent mixing step, known mixing means can be used without limitation. For example, a mixer such as a stirrer can be used. Further, ultrasonic irradiation, microwave irradiation, high speed homogenizer, pressure homogenizer, jet mill, ball mill, bead mill treatment and the like can be exemplified. In the mixing step, a heating step may be used in combination.
混合工程後は、必要に応じて、濾別工程を行うことができる。濾別に用いるフィルターとしては、テフロン（登録商標）性メンブレン等が好適に用いられる。用途により最適な孔径を選定する。通常、濾取工程を行った後に、良溶媒を用いて洗浄を行う。これらの工程を経て、塩等の不純物を除去する。 After the mixing step, a filtering step can be performed if necessary. As the filter used for each filter, a Teflon (registered trademark) membrane or the like is preferably used. Select the optimum hole diameter according to the application. Usually, after performing the filtration step, washing is performed with a good solvent. Through these steps, impurities such as salts are removed.
濾別工程（濾取工程）を行った後または濾別工程（濾取工程）を行わずに、本実施形態に係る有機溶媒に再分散させ、サイズ分画工程を行うことができる。サイズ分画の方法としては、遠心分離法、透析、濾過（限外濾過、加圧濾過、減圧濾過等）、超遠心分離などが例示できる。 After performing the filtration step (filtering step) or without performing the filtering step (filtering step), the size fractionation step can be performed by redispersing in the organic solvent according to the present embodiment. Examples of the size fractionation method include centrifugation, dialysis, filtration (ultrafiltration, pressure filtration, vacuum filtration, etc.), ultracentrifugation, and the like.
これらの工程を経て、層状鉱物粉体の剥離が行われる。剥離を促進させる方法としては、塩濃度を高くしたり、混合処理を長くしたり撹拌条件をハードにしたりすることが有効である。層状鉱物粉体が剥離されるメカニズムは、上記特定の有機溶媒中で層状鉱物粉体と塩を接触させることによって、塩の一部が解離し、層状鉱物粉体と塩の対カチオンが相互に結合又は配位し、これにより層状鉱物粉体に静電反発が誘起され、層状鉱物粉体の剥離が起こるものと考察している。層状鉱物粉体と塩の対カチオンとの結合又は配位は、主として層状鉱物粉体のエッジ部において形成されているものと考えている。従って、これらの工程により得られる層状鉱物粉体は、主としてエッジ部に塩の対カチオンが結合又は配位されていると考えられる。塩の対アニオン、層状鉱物粉体と結合していない対カチオンおよび塩は、溶液とともに容易に除去できるが、残存していてもよい。 Through these steps, the layered mineral powder is exfoliated. As a method for promoting exfoliation, it is effective to increase the salt concentration, lengthen the mixing treatment, or make the stirring conditions hard. The mechanism by which the layered mineral powder is exfoliated is that when the layered mineral powder and the salt are brought into contact with each other in the above-mentioned specific organic solvent, a part of the salt is dissociated and the paired cations of the layered mineral powder and the salt are mutually. It is considered that the bond or coordination causes electrostatic repulsion to be induced in the layered mineral powder, and the layered mineral powder is peeled off. It is considered that the bond or coordination between the layered mineral powder and the counter cation of the salt is mainly formed at the edge portion of the layered mineral powder. Therefore, it is considered that the layered mineral powder obtained by these steps has a salt counter-cation bonded or coordinated mainly at the edge portion. The counter anion of the salt, the counter cation not bound to the layered mineral powder and the salt can be easily removed with the solution, but may remain.
本実施形態に係る層状鉱物粉体の剥離方法によれば、特定の有機溶媒に対して塩と原料の層状鉱物粉体を加え、混合工程を行うという簡便な工程により行うので、生産性を格段に高めることができる。なお、剥離後の層状鉱物粉体は、原料の層状鉱物粉体に比して薄膜化されているものであり、層状鉱物粉体のエッジ部には、塩のカチオン対が結合または配位していると考えられる。得られた分散液は、そのまま若しくは精製して利用することができる。また、分散液に樹脂等を加えて、例えばペースト材料として利用できる。また、インク等の組成物として利用することもできる。また、分散液から塩等の不要物を除去し、有機溶媒を留去して粉体として用いることができる。有機溶媒を留去する際の乾燥工程は、例えば、加熱乾燥、真空乾燥またはこれらを組み合わせる例が挙げられる。 According to the layered mineral powder peeling method according to the present embodiment, the salt and the layered mineral powder as a raw material are added to a specific organic solvent, and the mixing step is performed, so that the productivity is significantly improved. Can be enhanced to. The layered mineral powder after peeling is thinner than the layered mineral powder of the raw material, and the cation pair of the salt is bonded or coordinated to the edge portion of the layered mineral powder. It is thought that it is. The obtained dispersion can be used as it is or after purification. Further, it can be used as a paste material, for example, by adding a resin or the like to the dispersion liquid. It can also be used as a composition such as ink. Further, unnecessary substances such as salts can be removed from the dispersion liquid, and the organic solvent can be distilled off to use as a powder. Examples of the drying step for distilling off the organic solvent include heat drying, vacuum drying, or a combination thereof.
層状ナノプレート複合体は、分散液のまま用いる他、例えばペーストや粉体として又はシート状に形成して利用できるが、層状ナノプレート複合体からカチオン成分を除去することもできる。後者の場合には、加熱により容易にアンモニウム成分を除去できる観点から、アンモニウムイオンが結合した層状ナノプレート複合体が好ましい。樹脂と層状ナノプレート複合体の含有比はニーズに応じて適宜設計できる。樹脂に対する層状ナノプレート複合体の含有量は、例えば０．１〜９５質量％である。基材に塗工して塗膜を形成してもよい。 The layered nanoplate complex can be used as it is as a dispersion, for example, as a paste or powder, or can be formed in the form of a sheet, but the cation component can also be removed from the layered nanoplate complex. In the latter case, a layered nanoplate composite to which ammonium ions are bonded is preferable from the viewpoint that the ammonium component can be easily removed by heating. The content ratio of the resin and the layered nanoplate complex can be appropriately designed according to the needs. The content of the layered nanoplate complex with respect to the resin is, for example, 0.1 to 95% by mass. The substrate may be coated to form a coating film.
組成物として用いる場合には、塩を必要に応じて除去した後、他の化合物を添加することができる。他の化合物は、目的およびニーズに応じて適宜選定できる。好適な例として樹脂、分散剤、消泡剤、可塑剤、酸化防止剤、着色剤および結着材等を加えてもよい。樹脂は、熱可塑性樹脂、硬化性化合物を含む熱硬化性樹脂等が例示できる。また、感光性樹脂、導電性樹脂も好適に用いられる。熱可塑性樹脂としては、（メタ）アクリル系ポリマー、ポリオレフィン樹脂、ポリアミド樹脂、ポリスチレン、ポリカーボネート、ポリエチレンテレフタレート、フェノキシ樹脂、感光性樹脂等が挙げられる。また、耐衝撃性向上のために、熱可塑性樹脂組成物はその他のエラストマー成分を含有してもよい。また、樹脂として導電性高分子を用い、グラフェンおよび／またはグラファイトと導電性高分子の相乗効果によって導電特性を発現させることができる。樹脂と層状ナノプレート複合体の含有比は、ニーズに応じて適宜設計できる。樹脂に対する層状ナノプレート複合体の含有量は、例えば、０．１〜９５質量％である。 When used as a composition, other compounds can be added after removing the salt as needed. Other compounds can be appropriately selected according to the purpose and needs. As a suitable example, a resin, a dispersant, an antifoaming agent, a plasticizer, an antioxidant, a coloring agent, a binder and the like may be added. Examples of the resin include a thermoplastic resin, a thermosetting resin containing a curable compound, and the like. Further, a photosensitive resin and a conductive resin are also preferably used. Examples of the thermoplastic resin include (meth) acrylic polymers, polyolefin resins, polyamide resins, polystyrenes, polycarbonates, polyethylene terephthalates, phenoxy resins, and photosensitive resins. Further, in order to improve the impact resistance, the thermoplastic resin composition may contain other elastomer components. Further, when a conductive polymer is used as the resin, the conductive property can be exhibited by the synergistic effect of graphene and / or graphite and the conductive polymer. The content ratio of the resin and the layered nanoplate complex can be appropriately designed according to the needs. The content of the layered nanoplate complex with respect to the resin is, for example, 0.1 to 95% by mass.
非特許文献１、特許文献１の方法によれば、酸化・還元反応を行う工程を含んでおり生産性が高いとはいえなかった。また、特許文献２〜４の方法によれば、特定のイオン液体、活性メチレン化合物誘導体或いはポリ芳香族炭化水素化合物等を用意する必要があり、生産性が高いとはいえなかった。更に、非特許文献２の方法によれば、ＮＭＰ、ＤＭＦ又はＤＭＳＯを用いるので、例えばシート化するときの乾燥工程において分散液のポストプロセス性に課題があった。
According to the methods of
一方、本実施形態に係る層状鉱物粉体の剥離方法によれば、数式（１）および数式（２）を満たす有機溶媒を用い、且つ酸解離定数ｐＫａ（Ｈ２Ｏ）が０越えの酸からなる塩を用いることによって、層状鉱物粉体の剥離を簡便且つ短時間に行うことができる。また、市販の塩を用いることができるので製造工程が簡便であり、生産性が高められる。これは、塩の対アニオンが結合又は配位された層状ナノプレート複合体の互いの静電反発により分散性が高まることによって、有機溶媒中での分散性を顕著に高められたものと考えている。また、得られる層状ナノプレート複合体の経時的安定性も向上させることができる。 On the other hand, according to the method for peeling layered mineral powder according to the present embodiment, an organic solvent satisfying the formulas (1) and (2) is used, and the acid dissociation constant pKa (H 2 O) is from an acid exceeding 0. By using the salt, the layered mineral powder can be easily and quickly peeled off. Further, since a commercially available salt can be used, the manufacturing process is simple and the productivity is enhanced. It is considered that this is because the dispersibility in the organic solvent is remarkably enhanced by increasing the dispersibility due to the mutual electrostatic repulsion of the layered nanoplate complex to which the counter anion of the salt is bonded or coordinated. There is. In addition, the stability of the obtained layered nanoplate complex over time can be improved.
また、混合工程において外部エネルギーの有無およびその強度を調整することが容易であり、遠心分離後の再分離によるサイズ分画も容易である。また、本実施形態に係る層状鉱物粉体の剥離方法によれば、製造コスト低減を図ることができる。また、剥離により、原料の層状鉱物粉体に比して表面積を高めることができるというメリットを有する。また、これに付随して層状鉱物粉体の特性（例えば伝導性等）を高めることが期待できる。 In addition, it is easy to adjust the presence or absence of external energy and its strength in the mixing step, and it is easy to perform size fractionation by re-separation after centrifugation. Further, according to the layered mineral powder peeling method according to the present embodiment, the manufacturing cost can be reduced. Further, the peeling has an advantage that the surface area can be increased as compared with the layered mineral powder of the raw material. In addition, it can be expected that the characteristics (for example, conductivity, etc.) of the layered mineral powder will be enhanced accordingly.
［層状ナノプレート複合体の製造方法］
次に、本実施形態に係る層状ナノプレート複合体の製造方法について説明する。層状ナノプレート複合体の製造方法には、層状鉱物粉体を剥離する態様（上記層状鉱物粉体の剥離方法と重複する）の他、層状鉱物粉体（この場合には層状ナノプレート複合体）は剥離しないが、分散を格段に向上させる態様およびこれらの組合せが含まれる。また、上記層状鉱物粉体の剥離方法と層状ナノプレート複合体の製造方法とは、前者が得られる化合物がナノオーダー（０．３ｎｍ以上、１０００ｎｍ未満）に限定されない点、後者が剥離せずに分散する態様も含む点において相違しており、目的が異なる場合も想定されるが、両者のいずれにも該当している場合も含まれている。従って、基本的には、上記実施形態と同様の工程を有する。
[Manufacturing method of layered nanoplate complex]
Next, a method for producing the layered nanoplate complex according to the present embodiment will be described. The method for producing the layered nanoplate composite includes a mode of peeling the layered mineral powder (which overlaps with the above-mentioned peeling method of the layered mineral powder) and a layered mineral powder (in this case, the layered nanoplate composite). Does not peel, but includes embodiments and combinations thereof that significantly improve dispersion. Further, in the method for exfoliating the layered mineral powder and the method for producing the layered nanoplate composite, the former is not limited to the nano-order (0.3 nm or more and less than 1000 nm), and the latter is not exfoliated. It differs in that it also includes a dispersal mode, and it is assumed that the purpose is different, but it also includes cases where both are applicable. Therefore, it basically has the same steps as those in the above embodiment.
本実施形態に係る層状ナノプレート複合体の製造方法は、上述した数式（１）および数式（２）を満たす有機溶媒中に、層状鉱物粉体と有機溶媒に分散する塩とを加える添加工程と、得られた混合液を撹拌する混合工程とを含む。塩は、前述した通り、当該塩の対アニオンの酸の酸解離定数ｐＫａ（Ｈ２Ｏ）が０より大きい塩である。添加工程と混合工程は同時に行っても、順に行ってもよい。 The method for producing a layered nanoplate composite according to the present embodiment includes a step of adding a layered mineral powder and a salt dispersed in the organic solvent to an organic solvent satisfying the above-mentioned formulas (1) and (2). , Includes a mixing step of stirring the resulting mixture. Salt, as described above, the acid dissociation constant pKa of an acid counteranion of the salt (H 2 O), etc. are greater than zero salt. The addition step and the mixing step may be carried out at the same time or in order.
（層状ナノプレート複合体）
本実施形態に係る層状ナノプレート複合体は、元の層状鉱物粉体を有機溶媒中で塩と共に添加して、混合した後に得られる層状鉱物粉体と塩の対カチオンとが結合又は配位した複合体をいう。層状ナノプレート複合体の厚みは０．３ｎｍ以上、１０００ｎｍ未満のナノメータオーダーにあるものをいい、単層体または積層体が含まれる。用途によるが、層状ナノプレートの厚みは１００ｎｍ未満であることがより好ましい。本実施形態に係る層状ナノプレート複合体の製造方法によれば、分散性が顕著に優れる分散液を提供できる。また、常温・常圧で短時間に調製できるので生産性が高いという優れた効果を有している。なお、層状ナノプレート複合体は、原料として用いる層状鉱物粉体より薄膜化されていても、同サイズであってもよい。
(Layered nanoplate complex)
In the layered nanoplate composite according to the present embodiment, the original layered mineral powder is added together with a salt in an organic solvent and mixed, and the layered mineral powder obtained after mixing and the countercation of the salt are bonded or coordinated. Refers to a complex. The thickness of the layered nanoplate complex is on the order of nanometers of 0.3 nm or more and less than 1000 nm, and includes a single layer or a laminated body. Depending on the application, the thickness of the layered nanoplate is more preferably less than 100 nm. According to the method for producing a layered nanoplate complex according to the present embodiment, it is possible to provide a dispersion liquid having remarkably excellent dispersibility. In addition, it has an excellent effect of high productivity because it can be prepared in a short time at normal temperature and pressure. The layered nanoplate complex may be thinner than the layered mineral powder used as a raw material, or may have the same size.
（層状鉱物粉体）
層状ナノプレート複合体の製造方法に用いる層状鉱物粉体は、前述と同様に層状に積層された粉体状の層状鉱物である。原料として用いる「層状鉱物粉体」のサイズは、層状ナノプレート複合体が得られればよく特に限定されない。例えば、ミリオーダーの顆粒状の粉体、マイクロまたはナノサイズの微粒子等が挙げられる。層状鉱物粉体の種類は、上述した粉体に加えて、グラフェン量子ドットが例示できる。
(Layered mineral powder)
The layered mineral powder used in the method for producing a layered nanoplate complex is a powdery layered mineral laminated in layers as described above. The size of the "layered mineral powder" used as a raw material is not particularly limited as long as a layered nanoplate composite can be obtained. For example, milliorder granular powder, micro or nano-sized fine particles, and the like can be mentioned. Examples of the type of layered mineral powder include graphene quantum dots in addition to the above-mentioned powder.
例えば、層状鉱物粉体としてグラフェンを用い、単層または積層数の少ないグラフェンナノプレート複合体を得たり、単層のグラフェンやグラフェン量子ドットを層状鉱物粉体として用い、高分散化された分散液を得たりしてもよい。用いる層状鉱物粉体は１種でも複数種でもよい。 For example, graphene is used as the layered mineral powder to obtain a single-layer or graphene nanoplate composite with a small number of layers, or single-layer graphene or graphene quantum dots are used as the layered mineral powder to obtain a highly dispersed dispersion. May be obtained. The layered mineral powder used may be one kind or a plurality of kinds.
（有機溶媒）
本実施形態に係る有機溶媒は、比誘電率が上記数式（１）および数式（２）を満たすものを用いる。好ましい範囲や有機溶媒の種類等については上述したとおりである。
(Organic solvent)
As the organic solvent according to the present embodiment, a solvent having a relative permittivity satisfying the above formulas (1) and (2) is used. The preferred range, the type of organic solvent, and the like are as described above.
（塩）
本実施形態に係る塩は、有機溶媒中で層状鉱物粉体を分散させる役割を担う。層状鉱物粉体を剥離する役割も兼ね備えることができる。本実施形態に係る塩は、前述した通り、この塩を構成する対アニオンの酸の酸解離定数ｐＫａ（Ｈ２Ｏ）が０より大きい塩を用いる。好適な塩の対アニオンの酸や対カチオンの好ましい例、好ましい濃度等は前述した通りである。
(salt)
The salt according to this embodiment plays a role of dispersing the layered mineral powder in an organic solvent. It can also have the role of exfoliating layered mineral powder. Salts according to the present embodiment, as described above, the acid dissociation constant pKa of an acid of the counter anion constituting the salt (H 2 O), etc. are used greater than zero salt. Preferred examples, preferred concentrations, etc. of the acid and cation of the counter anion of the suitable salt are as described above.
有機溶媒に塩と層状鉱物粉体を加える添加工程を行う際の環境条件は特に限定されず、上述した層状鉱物粉体の剥離方法と同様の例が挙げられる。また、混合工程後、必要に応じて行う濾別、洗浄、サイズ分画工程等についても前述したとおりである。 The environmental conditions when performing the addition step of adding the salt and the layered mineral powder to the organic solvent are not particularly limited, and the same examples as the above-mentioned peeling method of the layered mineral powder can be mentioned. Further, after the mixing step, the filtration, washing, size fractionation step and the like, which are performed as necessary, are also as described above.
これらの工程を経て、層状ナノプレート複合体が製造される。分散性をよい高める方法としては、塩濃度や混合処理条件を調整する方法がある。本実施形態に係る層状ナノプレート複合体の製造方法によれば、特定の有機溶媒に対して塩と原料の層状鉱物粉体を加え、混合工程を行うという簡便な工程であることから、生産性を格段に高めることができる。 Through these steps, a layered nanoplate composite is produced. As a method for improving the dispersibility, there is a method of adjusting the salt concentration and the mixing treatment conditions. According to the method for producing a layered nanoplate composite according to the present embodiment, it is a simple step of adding a salt and a layered mineral powder as a raw material to a specific organic solvent and performing a mixing step, so that the productivity is high. Can be significantly enhanced.
また、層状鉱物粉体の分散性を顕著に高め、経時的安定性に優れる分散液を提供できる。また、層状ナノプレート複合体にカウンターカチオンが結合又は配位していることで、溶媒中あるいはスラリーにおいて層状ナノプレート複合体の分散性を向上させることができる。 Further, it is possible to remarkably enhance the dispersibility of the layered mineral powder and provide a dispersion liquid having excellent stability over time. Further, by binding or coordinating the counter cation to the layered nanoplate complex, the dispersibility of the layered nanoplate complex can be improved in the solvent or in the slurry.
層状ナノプレート複合体の用途としてはインク、機能性コート膜、電極触媒の担持体、導電性複合体、電極等の電子部材、各種センサー等が例示できる。また、建材用途、塗料、医療機器など幅広い応用が期待できる。 Examples of the use of the layered nanoplate composite include ink, a functional coat film, a carrier for an electrode catalyst, a conductive composite, an electronic member such as an electrode, and various sensors. In addition, it can be expected to have a wide range of applications such as building material applications, paints, and medical equipment.
＜実施例＞
以下、本発明を実施例により更に詳細に説明する。但し、本発明は以下の実施例により何ら限定されるものではない。
<Example>
Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the following examples.
有機溶媒は、乾燥工程を行わずそのまま用いた。塩は、市販品をそのまま用いた。 The organic solvent was used as it was without performing the drying step. As the salt, a commercially available product was used as it was.
（実施例１）
常温下、空気中でアセトン１００ｍＬに１ｇの二硫化モリブデン（ニチモリ社製）を添加して撹拌した。この混合物に、リン酸カリウムの粉末を０．１ｇ加え、高出力超音波（６００Ｗ，ＳＭＴ社製）を１０分間照射した。リン酸カリウムを加える前、二硫化モリブデンはアセトン中で透明な分散液であった（図１中の左側のサンプル瓶）が、塩を添加して１０分間の超音波処理を行った後は分散性が劇的に向上し、濃い色の分散液が得られた（図１中の右側のサンプル瓶）。得られた懸濁液を一部採取し、ＴＥＭグリッド上に滴下した試料を透過型電子顕微鏡（ＴＥＭ）で観察した。その結果、図１の右側の写真に示すように、薄く透明な二硫化モリブデンのナノシートが形成されていることを確認した。
(Example 1)
At room temperature, 1 g of molybdenum disulfide (manufactured by Nichimori Co., Ltd.) was added to 100 mL of acetone in the air and stirred. To this mixture, 0.1 g of potassium phosphate powder was added, and high-power ultrasonic waves (600 W, manufactured by SMT) were irradiated for 10 minutes. Before adding potassium phosphate, molybdenum disulfide was a transparent dispersion in acetone (sample bottle on the left in FIG. 1), but after adding salt and sonicating for 10 minutes, it was dispersed. The properties were dramatically improved, and a dark-colored dispersion was obtained (sample bottle on the right side in FIG. 1). A part of the obtained suspension was collected, and the sample dropped on the TEM grid was observed with a transmission electron microscope (TEM). As a result, as shown in the photograph on the right side of FIG. 1, it was confirmed that a thin and transparent nanosheet of molybdenum disulfide was formed.
（実施例２）
二硫化モリブデンに代えて、窒化ホウ素（昭和電工社製）を用いた以外は、実施例１と同様の方法により分散液を得た。リン酸カリウムを加える前、窒化ホウ素はアセトン中でクリアな白色を示していた（図２中の左側のサンプル瓶）が、塩を添加して１０分間の超音波処理を行った後は分散性が劇的に向上し、濁った白色の分散液が得られた（図２中の右側のサンプル瓶）。実施例１と同様の方法によりＴＥＭ像を観察したところ、図２に示すように、塩を添加する前に比して層厚が十分に薄い半透明状のナノシートが形成されていることを確認した。
(Example 2)
A dispersion was obtained by the same method as in Example 1 except that boron nitride (manufactured by Showa Denko KK) was used instead of molybdenum disulfide. Before adding potassium phosphate, boron nitride showed a clear white color in acetone (sample bottle on the left in FIG. 2), but after salt was added and ultrasonically treated for 10 minutes, it was dispersible. Was dramatically improved, and a cloudy white dispersion was obtained (sample bottle on the right side in FIG. 2). When the TEM image was observed by the same method as in Example 1, it was confirmed that, as shown in FIG. 2, a translucent nanosheet having a sufficiently thin layer thickness as compared with that before adding the salt was formed. did.
（実施例３）
二硫化モリブデンに代えて、黒鉛（和光純薬社製）を用いた以外は、実施例１と同様の方法により分散液を得た。リン酸カリウムを加える前、黒鉛はアセトン中で灰色の透明なグラフェン分散液であった（図中の左側のサンプル瓶）。一方、リン酸カリウムを添加して超音波処理を行った後は分散性が劇的に向上し、黒色不透明な分散液が得られた（図中の右側のサンプル瓶）。実施例１と同様の方法によりＴＥＭ像を観察したところ、図３に示すように、透明なグラフェンのナノシートが形成されていることを観察した。
(Example 3)
A dispersion was obtained by the same method as in Example 1 except that graphite (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of molybdenum disulfide. Before adding potassium phosphate, graphite was a gray clear graphene dispersion in acetone (sample bottle on the left in the figure). On the other hand, after the addition of potassium phosphate and sonication, the dispersibility was dramatically improved, and a black opaque dispersion was obtained (sample bottle on the right side of the figure). When the TEM image was observed by the same method as in Example 1, it was observed that a transparent graphene nanosheet was formed as shown in FIG.
（実施例４〜２４）
表１に示す条件に従い、実施例４〜２４に係る分散液を得た。表１に示す条件以外は、実施例１と同様の条件とした。実施例１４〜１９、２１〜２３については、混合した後にサイズ分画工程として遠心処理（１５００ｒｐｍ×３０分）を行い、上澄み液を採取した。
Dispersions according to Examples 4 to 24 were obtained according to the conditions shown in Table 1. Except for the conditions shown in Table 1, the conditions were the same as in Example 1. For Examples 14 to 19 and 21 to 23, after mixing, centrifugation (1500 rpm × 30 minutes) was performed as a size fractionation step, and the supernatant was collected.
（比較例１〜５）
表２に示す条件に従い、比較例１〜５に係る分散液を得た。表１に示す条件以外は、実施例１と同様とした。
According to the conditions shown in Table 2, the dispersion liquids according to Comparative Examples 1 to 5 were obtained. The conditions were the same as in Example 1 except for the conditions shown in Table 1.
実施例４〜２３の上澄み液を採取し、吸光度を測定した結果を表３に示す。また、比較例１〜８の上澄み液について、同様の方法で吸光度を測定した結果を表４に示す。
実施例１８の分散液の吸光度は３．８４であった。一方、塩を添加しない以外は同一条件である比較例６の分散液の吸光度は０．１４５であり、塩添加によって分散性が顕著に向上することを確認した。
また、実施例１９の分散液の吸光度は、ジェットミル処理後の微細粉末黒鉛を用いた以外は実施例１８と同様の条件で実験を行ったものであるが、1回の処理で吸光度は１０．３まで向上することを確認した。
さらに、アセトンとエタノールの混合有機溶媒からなる実施例２０の分散液の吸光度は１．２３であった。一方、塩を添加しない以外は実施例２０と同一条件である比較例６の分散液の吸光度は０．０３５であり、塩添加によって分散性を格段に向上できることを確認した。
The absorbance of the dispersion of Example 18 was 3.84. On the other hand, the absorbance of the dispersion liquid of Comparative Example 6 under the same conditions except that no salt was added was 0.145, and it was confirmed that the dispersibility was significantly improved by the addition of the salt.
The absorbance of the dispersion liquid of Example 19 was the same as that of Example 18 except that the fine powder graphite after the jet mill treatment was used, but the absorbance was 10 in one treatment. It was confirmed that it improved to 0.3.
Further, the absorbance of the dispersion liquid of Example 20 composed of a mixed organic solvent of acetone and ethanol was 1.23. On the other hand, the absorbance of the dispersion liquid of Comparative Example 6 under the same conditions as in Example 20 except that no salt was added was 0.035, and it was confirmed that the dispersibility could be significantly improved by adding the salt.
アセトンとＮＭＰの混合有機溶媒からなる実施例２１の分散液の吸光度は１．１６であった。一方、塩を添加しない以外は実施例２１と同一条件である比較例７の分散液の吸光度は０．０１４であり、分散性が顕著に向上することを確認した。
また、アセトンとトルエン混合有機溶媒からなる実施例２２の分散液の吸光度は１．３２であった。一方、塩を添加しない以外は実施例２２と同一条件である比較例８の分散液の吸光度は０．１４であり、塩添加によって分散性が顕著に向上することを確認した。
The absorbance of the dispersion of Example 21 consisting of a mixed organic solvent of acetone and NMP was 1.16. On the other hand, the absorbance of the dispersion liquid of Comparative Example 7 under the same conditions as in Example 21 except that no salt was added was 0.014, confirming that the dispersibility was significantly improved.
Further, the absorbance of the dispersion liquid of Example 22 composed of a mixed organic solvent of acetone and toluene was 1.32. On the other hand, the absorbance of the dispersion liquid of Comparative Example 8 under the same conditions as in Example 22 except that no salt was added was 0.14, and it was confirmed that the dispersibility was significantly improved by the addition of the salt.
粒径の小さい黒鉛Ｚ５Ｆ（伊藤黒鉛社製）を用いて得た実施例２３の高濃度グラフェン分散液の吸光度は３５であり、グラフェン濃度約１．０６ｇ／Ｌの高濃度分散液を僅か５分で得られることが確認できた。
実施例２４の分散液においては、経時的に沈降が認められたものの２４時間後も黒色不透明な分散液が存在していることを確認した（図４中の左側の写真）。一方、塩を添加しない以外は実施例２４と同一の条件で行った比較例９は、僅か３０分で沈降してしまい、上澄み液は透明であることを確認した（図４中の右側の写真）。
The absorbance of the high-concentration graphene dispersion of Example 23 obtained using graphite Z5F (manufactured by Ito Graphite Co., Ltd.) having a small particle size is 35, and the high-concentration graphene dispersion having a graphene concentration of about 1.06 g / L is used for only 5 minutes. It was confirmed that it can be obtained with.
In the dispersion liquid of Example 24, although sedimentation was observed over time, it was confirmed that a black opaque dispersion liquid was present even after 24 hours (photograph on the left side in FIG. 4). On the other hand, Comparative Example 9, which was carried out under the same conditions as in Example 24 except that no salt was added, settled in only 30 minutes, and it was confirmed that the supernatant was transparent (photograph on the right side in FIG. 4). ).
次に、アセトン、イソプロパノール、エタノール、ＴＨＦ，トルエンの各溶媒を１００ｍＬ入れた試験管をそれぞれ２本ずつ用意し、それぞれの試験管に天然黒鉛０．５ｇを加えた。そして、各溶媒の一組（２本）の試験管の一方にのみ、塩（炭酸アンモニウム）を１ｇ／Ｌとなるように加えた。これらの試験管に対し，超音波処理を５分行った。その後、１５００ｒｐｍ×３０分の遠心処理を行い、６６０ｎｍの吸光度を測定し、当該測定値を吸光度係数（３３００）で除すことによりグラフェン濃度ｇ／Ｌを求めた。その結果を図５に示す。 Next, two test tubes each containing 100 mL of each solvent of acetone, isopropanol, ethanol, THF, and toluene were prepared, and 0.5 g of natural graphite was added to each test tube. Then, a salt (ammonium carbonate) was added to only one of the test tubes of one set (two) of each solvent so as to be 1 g / L. These test tubes were sonicated for 5 minutes. Then, centrifugation was performed at 1500 rpm for 30 minutes, the absorbance at 660 nm was measured, and the measured value was divided by the absorbance coefficient (3300) to determine the graphene concentration g / L. The results are shown in FIG.
アセトン、イソプロパノール、エタノール、ＴＨＦを用いた分散液は、塩を添加することにより、グラフェン濃度が顕著に向上することを確認した。また、トルエンの場合には、塩添加の有無にかかわらずグラフェン濃度が低いことを確認した。 It was confirmed that the graphene concentration of the dispersion liquid using acetone, isopropanol, ethanol and THF was significantly improved by adding a salt. In the case of toluene, it was confirmed that the graphene concentration was low regardless of the presence or absence of salt addition.
Claims (5)
有機溶媒中に、層状鉱物粉体と前記有機溶媒に分散する塩とを加える添加工程と、
得られた混合液を撹拌する混合工程とを含み、
前記層状鉱物粉体は、前記添加工程の前に酸による処理を行わず、且つ前記混合液には、前記塩に由来する酸以外の酸および水を含まず、
前記有機溶媒は、以下の数式（１）および数式（２）を満たし、
前記塩は、当該塩の対アニオンの酸の酸解離定数ｐＫａ（Ｈ２Ｏ）が０より大きい塩である、
層状鉱物粉体の剥離方法。
［数式（１）］
４≦有機溶媒１の体積比率×有機溶媒１の比誘電率＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の比誘電率≦６０
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。
［数式（２）］
有機溶媒１の体積比率×有機溶媒１の沸点＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の沸点＜１００℃
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。 It is a method of exfoliating layered mineral powder into layers.
An addition step of adding a layered mineral powder and a salt dispersed in the organic solvent to the organic solvent, and
Including a mixing step of stirring the obtained mixed liquid,
The layered mineral powder was not treated with an acid before the addition step, and the mixture did not contain an acid other than the acid derived from the salt and water.
The organic solvent satisfies the following mathematical formulas (1) and (2).
The salt is a salt in which the acid dissociation constant pKa (H 2 O) of the acid of the counter anion of the salt is larger than 0.
A method for exfoliating layered mineral powder.
[Formula (1)]
4 ≤ Volume ratio of organic solvent 1 x Relative permittivity of organic solvent 1 + ... + Volume ratio of organic solvent n-1 x Relative permittivity of organic solvent n-1 ≤ 60
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
[Formula (2)]
Volume ratio of organic solvent 1 x boiling point of organic solvent 1 + ... + volume ratio of organic solvent n-1 x boiling point of organic solvent n-1 <100 ° C.
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
得られた混合液を撹拌する混合工程とを含み、
前記層状鉱物粉体は、前記添加工程の前に酸による処理を行わず、且つ前記混合液には、前記塩に由来する酸以外の酸および水を含まず、
前記有機溶媒は、以下の数式（１）および数式（２）を満たし、
前記塩は、当該塩の対アニオンの酸の酸解離定数ｐＫａ（Ｈ２Ｏ）が０より大きい塩である、
層状ナノプレート複合体の製造方法。
［数式（１）］
４≦有機溶媒１の体積比率×有機溶媒１の比誘電率＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の比誘電率≦６０
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。
［数式（２）］
有機溶媒１の体積比率×有機溶媒１の沸点＋・・＋有機溶媒ｎ−１の体積比率×有機溶媒ｎ−１の沸点＜１００℃
但し、ｎは１以上の整数であり、ｎ＝１は単独溶媒、ｎ≧２は混合溶媒を示す。 An addition step of adding a layered mineral powder and a salt dispersed in the organic solvent to the organic solvent, and
Including a mixing step of stirring the obtained mixed liquid,
The layered mineral powder was not treated with an acid before the addition step, and the mixture did not contain an acid other than the acid derived from the salt and water.
The organic solvent satisfies the following mathematical formulas (1) and (2).
The salt is a salt in which the acid dissociation constant pKa (H 2 O) of the acid of the counter anion of the salt is larger than 0.
A method for producing a layered nanoplate complex.
[Formula (1)]
4 ≤ Volume ratio of organic solvent 1 x Relative permittivity of organic solvent 1 + ... + Volume ratio of organic solvent n-1 x Relative permittivity of organic solvent n-1 ≤ 60
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
[Formula (2)]
Volume ratio of organic solvent 1 x boiling point of organic solvent 1 + ... + volume ratio of organic solvent n-1 x boiling point of organic solvent n-1 <100 ° C.
However, n is an integer of 1 or more, n = 1 indicates a single solvent, and n ≧ 2 indicates a mixed solvent.
前記濾取工程後、溶媒に再分散させ、サイズ分画する工程を含む請求項２に記載の層状ナノプレート複合体の製造方法。 After the mixing step, a filtering step of filtering by filtration and a filtering step of filtering are performed.
The method for producing a layered nanoplate complex according to claim 2, further comprising a step of redispersing in a solvent and fractionating the size after the filtration step.
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017198450A JP6979196B2 (en) | 2017-10-12 | 2017-10-12 | Method for exfoliating layered mineral powder and method for producing layered nanoplate complex |
| EP18865633.4A EP3696143A4 (en) | 2017-10-12 | 2018-10-12 | Inorganic-particle composite, production method therefor, and inorganic-particle composite dispersion |
| US16/755,137 US20200331761A1 (en) | 2017-10-12 | 2018-10-12 | Inorganic particle composite, method for producing the same, and inorganic particle composite dispersion |
| PCT/JP2018/038171 WO2019074109A1 (en) | 2017-10-12 | 2018-10-12 | Inorganic-particle composite, production method therefor, and inorganic-particle composite dispersion |
| CN202311113185.2A CN117142522A (en) | 2017-10-12 | 2018-10-12 | Inorganic particle composite, method for producing same, inorganic particle composite dispersion liquid, and composition |
| CN202311113177.8A CN117142463A (en) | 2017-10-12 | 2018-10-12 | Method for peeling layered mineral powder and method for producing layered nanosheet composite |
| KR1020207010990A KR20200068670A (en) | 2017-10-12 | 2018-10-12 | Inorganic particle composite and manufacturing method thereof, and dispersion of inorganic particle composite |
| CA3078591A CA3078591A1 (en) | 2017-10-12 | 2018-10-12 | Inorganic particle composite, method for producing the same, and inorganic particle composite dispersion |
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