JP7148766B2 - METHOD OF FORMING CARBON NANOTUBE CONTAINING FILM - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for forming a carbon nanotube-containing film using fine mist obtained by atomizing a raw material solution.

Carbon nanotubes, which are composed only of carbon atoms, are materials with excellent electrical properties, thermal conductivity, and mechanical properties. In addition, carbon nanotubes are a material that is extremely lightweight, extremely tough, and has excellent elasticity and resilience. Carbon nanotubes with such excellent properties are extremely attractive and important substances as industrial materials.

In Patent Document 1, a carbon nanotube dispersion obtained by mixing a dispersion of aggregates of carbon nanotubes and a fluororubber, which is an elastomer, is spray-coated on a silicon substrate, and then the solvent is removed by heating and drying to remove the silicon substrate. Forming a carbon nanotube composite layer thereon is described. However, in the method described in Patent Document 1, it is difficult to uniformly disperse the carbon nanotubes and apply the spray coating, and after obtaining the carbon nanotube composite layer, it is necessary to further heat and dry for 5 hours or more. The process was complicated and took a long time. In addition, it is difficult to obtain a carbon nanotube composite layer in which the carbon nanotubes are uniformly dispersed, and the desired fluorescence peak wavelength cannot be obtained. I didn't.

Patent Document 2 discloses that a solution obtained by dissolving a combination of a single-walled carbon nanotube and a light-emitting compound in chloroform, dichloroethane, or carbon disulfide has an emission peak near 500 nm, and that this solution is used as a molding material. , describes that film-like single-walled carbon nanotubes (SWNT) can be obtained by molding into thin films. However, in Patent Document 2, there is no description that the single-walled carbon nanotube is actually formed into a film, and the single-walled carbon nanotube is chemically modified by covalently bonding the light-emitting compound. There was a problem that the optical characteristics were not stable.

In addition, in Non-Patent Document 1, an acetonitrile solution of multi-walled carbon nanotubes is subjected to electrochemical treatment to form carbon nanocrystals, and the obtained carbon nanocrystals emit light in the visible region (410 nm). It is stated that However, in the carbon nanocrystal described in Non-Patent Document 1, the structure of the carbon nanotube was destroyed by the electrochemical treatment, and the original characteristics of the carbon nanotube could not be exhibited. In addition, it has been difficult to obtain a film containing carbon nanotubes that exhibits good fluorescence in the visible region.

JP 2014-208727 A Japanese Patent Application Laid-Open No. 2005-036112

ZHOU, Jigang, et al. An electrochemical avenue to blue luminescent nanocrystals from multiwalled carbon nanotubes (MWCNTs). Journal of the American Chemical Society, 2007, 129.4: 744-745.

An object of the present invention is to provide a novel film-forming method capable of industrially advantageously forming a high-quality carbon nanotube-containing film.

As a result of intensive studies to achieve the above object, the present inventors atomized a raw material solution containing carbon nanotubes and a solvent, supplied a carrier gas to the obtained mist, and dispersed the mist with the carrier gas. When the carbon nanotube-containing film is formed on the substrate by transporting it to the substrate and then reacting the mist on the substrate, the carbon nanotube-containing film having good fluorescence characteristics is formed without chemically modifying the carbon nanotube. We found that a film can be formed simply and easily, and that the fluorescence peak wavelength can be easily adjusted. Found it.
Moreover, after obtaining the above knowledge, the inventors of the present invention conducted further studies and completed the present invention.

（式中、Ｒ^１およびＲ^２は、 それぞれ同一または異なって、水素原子、ハロゲン原子または置換基を有していてもよい炭化水素基または置換基を有していてもよい複素環基を表し、Ｒ^１およびＲ^２が結合して環を形成してもよい。）
［５］ 前記溶媒が、下記式（２）で表される前記［１］～［４］のいずれかに記載の成膜方法。

（式中、Ｒ^３、Ｒ^４およびＲ^５は、それぞれ同一または異なって、水素原子、ハロゲン原子または置換基を有していてもよい炭化水素基または置換基を有していてもよい複素環基を表し、Ｒ^３、Ｒ^４およびＲ^５から選ばれる任意の２つの基が結合して環を形成してもよい。）［６］ 前記霧化を、超音波振動を用いて行う前記［１］～［５］のいずれかに記載の成膜方法。
［７］ 前記反応が、熱反応である前記［１］～［６］のいずれかに記載の成膜方法。
［８］ 熱反応を３００℃以下の温度で行う前記［７］記載の成膜方法。
［９］ 未修飾のカーボンナノチューブを含むカーボンナノチューブ含有膜であって、５００ｎｍ以下に蛍光ピーク波長を有することを特徴とするカーボンナノチューブ含有膜。
［１０］ 光源と蛍光体膜とを少なくとも含む発光装置であって、前記蛍光体膜が、前記［９］記載のカーボンナノチューブ含有膜である発光装置。 Specifically, the present invention relates to the following inventions.
[1] A method of forming a carbon nanotube-containing film by reacting a raw material solution containing at least carbon nanotubes and a solvent, wherein the raw material solution is atomized, a carrier gas is supplied to the obtained mist, and the carrier A method of forming a film, characterized in that the mist is transported to the substrate with a gas, and then the mist is reacted on the substrate.
[2] The film forming method according to [1], wherein the solvent contains an organic solvent.
[3] The film forming method according to [1] or [2], wherein the solvent contains an oxygen atom-containing organic solvent.
[4] The film forming method according to any one of [1] to [3], wherein the solvent is represented by the following formula (1).

(wherein R ¹ and R ² are the same or different and represent a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group; , R ¹ and R ² may combine to form a ring.)
[5] The film forming method according to any one of [1] to [4], wherein the solvent is represented by the following formula (2).

(wherein R ³ , R ⁴ and R ⁵ are each the same or different and are a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic ring and any two groups selected from R ³ , R ⁴ and R ⁵ may combine to form a ring.) [6] The atomization is carried out using ultrasonic vibration [ 1] The film forming method according to any one of [5].
[7] The film forming method according to any one of [1] to [6], wherein the reaction is a thermal reaction.
[8] The film forming method according to [7], wherein the thermal reaction is performed at a temperature of 300° C. or lower.
[9] A carbon nanotube-containing film containing unmodified carbon nanotubes, wherein the carbon nanotube-containing film has a fluorescence peak wavelength of 500 nm or less.
[10] A light-emitting device comprising at least a light source and a phosphor film, wherein the phosphor film is the carbon nanotube-containing film according to [9] above.

According to the film forming method according to the embodiment of the present invention, it is possible to form a high-quality carbon nanotube-containing film in an industrially advantageous manner.

1 is a schematic configuration diagram of a film forming apparatus used in Examples. FIG. FIG. 10 is a diagram showing measurement results of fluorescence spectra of carbon nanotube-containing films obtained in Examples.

A film forming method according to an embodiment of the present invention is a method of forming a carbon nanotube-containing film by reacting a raw material solution containing at least carbon nanotubes and a solvent, wherein the raw material solution is atomized (atomization step). A carrier gas is supplied to the obtained mist, the mist is transported to the substrate by the carrier gas (transportation step), and then the mist is reacted on the substrate (film formation step). do.

(Atomization process)
The atomization step atomizes the raw material solution to generate mist. The atomization also includes making the raw material solution into droplets. The atomization means is not particularly limited as long as it can atomize the raw material solution, and may be a known atomization means. preferable. The mist preferably has an initial velocity of zero and floats in the air. For example, it is more preferable that the mist floats in space and can be transported as a gas, rather than being sprayed like a spray. Note that the mist includes liquid droplets. The droplet size of the mist is not particularly limited, and may be about several millimeters, preferably 50 μm or less, more preferably 1 to 10 μm.

(raw material solution)
The raw material solution contains at least carbon nanotubes and a solvent, is not particularly limited as long as it can be atomized, and may contain an inorganic material or an organic material. Moreover, the raw material solution may contain both inorganic materials and organic materials.

The carbon nanotube is not particularly limited as long as it does not interfere with the object of the present invention, and may be a single-walled carbon nanotube or a multi-walled carbon nanotube. In an embodiment of the present invention, the carbon nanotubes are preferably single-walled carbon nanotubes. Moreover, the method for producing the carbon nanotubes is not particularly limited, and examples thereof include an arc discharge method, a laser evaporation method, a chemical vapor deposition method, and the like. The carbon nanotubes may be chemically modified, but in the embodiment of the present invention, they are preferably unmodified. According to the film forming method of the present invention, a carbon nanotube-containing film can be easily and easily obtained even from unmodified carbon nanotubes. Further, the content of the carbon nanotubes in the raw material solution is not particularly limited, but in an embodiment of the present invention, it is preferably 0.01 g/L to 1.0 g/L, and 0.1 g/L More preferably ~1.0 g/L.

The solvent is not particularly limited as long as it does not interfere with the object of the present invention, and may be an inorganic solvent or an organic solvent. Normally, water is used as a solvent when forming a film by a mist deposition method, but in an embodiment of the present invention, the solvent contains an organic solvent to form the carbon nanotube-containing film more satisfactorily. It is preferably an organic solvent, more preferably an organic solvent, even more preferably an oxygen atom-containing organic solvent, and most preferably an oxygen atom-containing organic solvent. In the embodiment of the present invention, the fluorescence peak wavelength of the obtained carbon nanotube-containing film can be easily adjusted by forming the film by the mist deposition method using a predetermined solvent. The oxygen atom-containing organic solvent is not particularly limited as long as it can be used as a solvent and contains an oxygen atom in a heteroatom or substituent. In an embodiment of the present invention, the solvent is a solvent represented by the following formula (1), so that the raw material solution more suitable for ultrasonic atomization can be obtained, and the obtained carbon nanotubes A solvent represented by the following formula (2) is more preferable because it allows the contained film to exhibit better fluorescence properties in the visible region.

（式中、Ｒ^１およびＲ^２は、 それぞれ同一または異なって、水素原子、ハロゲン原子または置換基を有していてもよい炭化水素基または置換基を有していてもよい複素環基を表し、Ｒ^１およびＲ^２が結合して環を形成してもよい。）

(wherein R ¹ and R ² are the same or different and represent a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group; , R ¹ and R ² may combine to form a ring.)

（式中、Ｒ^３、Ｒ^４およびＲ^５は、それぞれ同一または異なって、水素原子、ハロゲン原子または置換基を有していてもよい炭化水素基または置換基を有していてもよい複素環基を表し、Ｒ^３、Ｒ^４およびＲ^５から選ばれる任意の２つの基が結合して環を形成してもよい。）

(wherein R ³ , R ⁴ and R ⁵ are each the same or different and are a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic ring represents a group, and any two groups selected from R ³ , R ⁴ and R ⁵ may combine to form a ring.)

"Halogen atom" includes, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

The "substituent" in the present invention includes, for example, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a halogen atom, a halogenated hydrocarbon group, -OR ^1a (R ^1a is a hydrogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group), —SR ^1b (R ^1b is a hydrogen atom, a substituent optionally substituted hydrocarbon group or optionally substituted heterocyclic group), optionally substituted acyl group, optionally substituted acyloxy group , optionally substituted alkoxycarbonyl group, optionally substituted aryloxycarbonyl group, optionally substituted alkylenedioxy group, nitro group, amino group, substituted amino cyano group, sulfo group, substituted silyl group, hydroxyl group, carboxy group, optionally substituted alkoxythiocarbonyl group, optionally substituted aryloxythiocarbonyl group, substituted an optionally substituted alkylthiocarbonyl group, an optionally substituted arylthiocarbonyl group, an optionally substituted carbamoyl group, a substituted phosphino group, an aminosulfonyl group, an alkoxysulfonyl group, an oxo group, etc. is mentioned.

"Hydrocarbon group" includes hydrocarbon groups and substituted hydrocarbon groups. Hydrocarbon groups include, for example, alkyl groups, aryl groups, aralkyl groups, and the like.

The alkyl group is preferably a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. Specific examples of alkyl groups include methyl, ethyl, n-propyl, 2-propyl, n-butyl, 1-methylpropyl, 2-methylpropyl, tert-butyl, n-pentyl, 1-methylbutyl, 1- ethylpropyl, tert-pentyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, n-hexyl, 1-methylpentyl, 1-ethylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-methylpentan-3-yl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl , 1-ethylbutyl, 2-ethylbutyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl. The alkyl group is more preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably an alkyl group having 1 to 4 carbon atoms.

As the aryl group, an aryl group having 6 to 20 carbon atoms is preferable. Specific examples of aryl groups include phenyl, indenyl, pentalenyl, naphthyl, azulenyl, fluorenyl, phenanthrenyl, anthracenyl, acenaphthylenyl, biphenylenyl, naphthacenyl, pyrenyl, and the like. The aryl group is more preferably an aryl group having 6 to 14 carbon atoms.

As the aralkyl group, an aralkyl group having 7 to 20 carbon atoms is preferred. Specific examples of the aralkyl group include benzyl, phenethyl, 1-phenylpropyl, 2-phenylpropyl, 3-phenylpropyl, 1-phenylbutyl, 2-phenylbutyl, 3-phenylbutyl, 4-phenylbutyl, 1- Phenylpentylbutyl, 2-phenylpentylbutyl, 3-phenylpentylbutyl, 4-phenylpentylbutyl, 5-phenylpentylbutyl, 1-phenylhexylbutyl, 2-phenylhexylbutyl, 3-phenylhexylbutyl, 4-phenylhexyl Butyl, 5-phenylhexylbutyl, 6-phenylhexylbutyl, 1-phenylheptyl, 1-phenyloctyl, 1-phenylnonyl, 1-phenyldecyl, 1-phenylundecyl, 1-phenyldodecyl, 1-phenyltridecyl or 1-phenyltetradecyl and the like. The aralkyl group is more preferably an aralkyl group having 7 to 12 carbon atoms.

Examples of the substituent that the "hydrocarbon group" may have include the aforementioned "substituent". Preferred examples of substituted hydrocarbon groups include substituted alkyl groups such as trifluoromethyl and methoxymethyl, tolyl (eg 4-methylphenyl), xylyl (eg 3,5-dimethylphenyl), 4-methoxy-3, Examples thereof include substituted aryl groups such as 5-dimethylphenyl and 4-methoxy-3,5-di-t-butylphenyl, and substituted aralkyl groups.

A heterocyclic group and a substituted heterocyclic group are mentioned as a "heterocyclic group which may have a substituent." Heterocyclic groups include aliphatic heterocyclic groups and aromatic heterocyclic groups.
The aliphatic heterocyclic group, for example, has 2 to 14 carbon atoms and contains at least 1, preferably 1 to 3 heteroatoms such as a nitrogen atom, an oxygen atom and/or a sulfur atom as a heteroatom. , 3- to 8-membered, preferably 5- or 6-membered monocyclic, polycyclic or condensed aliphatic heterocyclic groups. Specific examples of aliphatic heterocyclic groups include pyrrolidyl-2-one group, piperidyl group, piperidino group, piperazinyl group, morpholino group, morpholinyl group, tetrahydrofuryl group, tetrahydropyranyl group, thiolanyl group and succinimidyl group. is mentioned.

The aromatic heterocyclic group, for example, has 2 to 15 carbon atoms and contains at least 1, preferably 1 to 3 heteroatoms such as a nitrogen atom, an oxygen atom and/or a sulfur atom as a heteroatom, 3- to 8-membered, preferably 5- or 6-membered monocyclic, polycyclic or condensed cyclic heterocyclic groups, and specific examples include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, furazanyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-thiadiazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, tetrazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl , isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, 1,2-benzisoxazolyl, benzothiazolyl, benzopyranyl, 1,2-benzisothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl , quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, buteridinyl, carbazolyl, α-carbolinyl, β-carbolinyl, γ-carbolinyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, phenanthridinyl, phenanth Lolinyl, indolizinyl, pyrrolo[1,2-b]pyridazinyl, pyrazolo[1,5-a]pyridyl, imidazo[1,2-a]pyridyl, imidazo[1,5-a]pyridyl, imidazo[1,2 -b]pyridazinyl, imidazo[1,2-a]pyrimidinyl, 1,2,4-triazolo[4,3-a]pyridyl, 1,2,4-triazolo[4,3-b]pyridazinyl, benzo[1 ,2,5]thiadiazolyl, benzo[1,2,5]oxadiazolyl and phthalimino groups.

Examples of the substituent that the "heterocyclic group" may have include the aforementioned "substituent".

In the embodiment of the present invention, in formula (1), R ¹ and R ² are preferably condensed to form a ring, and in formula (2), R ³ , R ⁴ and R ⁵ It is also preferred that any two groups selected from are combined to form a ring. The ring formed by condensing R ¹ and R ² or the ring formed by combining any two groups selected from R ³ , R ⁴ and R ⁵ includes, for example, 1 to 3 Examples thereof include 5- to 20-membered rings optionally containing heteroatoms such as oxygen, nitrogen and sulfur atoms as ring-constituting atoms. Preferable rings to be formed include, for example, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclodecane ring, cyclododecane ring, cyclotetradecane ring, cyclopentadecane ring, cyclohexadecane ring and cycloheptadecane ring. monocyclic; condensed rings such as dihydronaphthalene ring, indene ring, indane ring, dihydroquinoline ring or dihydroisoquinoline ring, etc., and these rings usually contain 1 or 2 heteroatoms (e.g., oxygen atom, nitrogen atoms or sulfur atoms, etc.). Moreover, these rings may be substituted with a hydrocarbon group, a heterocyclic group, an alkoxy group, a substituted amino group, or the like. Specific examples of the hydrocarbon group and heterocyclic group include those described above for the hydrocarbon group and heterocyclic group.

The alkoxy group may be linear, branched or cyclic, and includes, for example, alkoxy groups having 1 to 6 carbon atoms, specifically methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, 2-butoxy group, isobutoxy group, tert-butoxy group, n-pentyloxy group, 2-methylbutoxy group, 3-methylbutoxy group, 2,2-dimethylpropyloxy group, n-hexyloxy group , 2-methylpentyloxy group, 3-methylpentyloxy group, 4-methylpentyloxy group, 5-methylpentyloxy group, cyclohexyloxy group, methoxymethoxy group, 2-ethoxyethoxy group and the like.

Substituted amino groups include amino groups in which one or two hydrogen atoms of an amino group have been replaced with a substituent. Specific examples of substituents of the substituted amino group include hydrocarbon groups (e.g., alkyl groups, etc.), aryl groups, aralkyl groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, aralkyloxycarbonyl groups, and the like. be done. Specific examples of amino groups substituted with alkyl groups, that is, alkyl group-substituted amino groups include, for example, N-methylamino group, N,N-dimethylamino group, N,N-diethylamino group, N,N-diisopropylamino mono- or dialkylamino groups such as N-methyl-N-isopropylamino group or N-cyclohexylamino group. Specific examples of an amino group substituted with an aryl group, that is, an aryl group-substituted amino group include, for example, N-phenylamino group, N,N-diphenylamino group, N-naphthylamino group, N-methyl-N-phenyl mono- or diarylamino groups such as an amino group or an N-naphthyl-N-phenylamino group; Specific examples of amino groups substituted with aralkyl groups, that is, aralkyl group-substituted amino groups include mono- or dialkylamino groups such as N-benzylamino groups and N,N-dibenzylamino groups. Also included are di-substituted amino groups such as N-benzyl-N-methylamino group. Specific examples of acyl-substituted amino groups, that is, acylamino groups, include formylamino, acetylamino, propionylamino, pivaloylamino, pentanoylamino, hexanoylamino, and benzoylamino groups. mentioned. Specific examples of an amino group substituted with an alkoxycarbonyl group, that is, an alkoxycarbonylamino group include, for example, a methoxycarbonylamino group, an ethoxycarbonylamino group, an n-propoxycarbonylamino group, an n-butoxycarbonylamino group, a tert-butoxy A carbonylamino group, a pentyloxycarbonylamino group, a hexyloxycarbonylamino group and the like can be mentioned. Specific examples of the amino group substituted with an aryloxycarbonyl group, i.e., the aryloxycarbonylamino group, include amino groups in which one hydrogen atom of the amino group is substituted with the above-mentioned aryloxycarbonyl group. Examples include, for example, a phenoxycarbonylamino group, a naphthyloxycarbonylamino group, and the like. Specific examples of an amino group substituted with an aralkyloxycarbonyl group, that is, an aralkyloxycarbonylamino group include, for example, a benzyloxycarbonylamino group.

The raw material solution may contain a solvent other than the solvents described above. Such a solvent is not particularly limited as long as it does not interfere with the object of the present invention, and may be an organic solvent other than the above solvents, or may be an inorganic solvent. A mixed solvent of an organic solvent and an inorganic solvent may be used. Examples of the organic solvent include alcohols, esters, ethers and the like. Examples of the inorganic solvent include water, and more specific examples include pure water, ultrapure water, tap water, well water, mineral spring water, mineral water, hot spring water, spring water, fresh water, and seawater.

(Conveyance process)
In the carrying step, after the atomization, a carrier gas is supplied to the mist, and the carrier gas carries the mist or the droplets to the substrate. In the present invention, a carrier gas is supplied to the mist instead of the raw material solution, and then the mist is transported and then formed into a film. Film formation can be performed, and surface unevenness of the obtained carbon nanotube-containing film can be suppressed more satisfactorily. The carrier gas is not particularly limited as long as it does not interfere with the object of the present invention. Suitable examples include oxygen, ozone, inert gases such as nitrogen and argon, and reducing gases such as hydrogen gas and forming gas. mentioned. In addition, although one type of carrier gas may be used, two or more types may be used, and a diluted gas with a reduced flow rate (for example, a 10-fold diluted gas, etc.) may be further used as a second carrier gas. good too. In addition, the carrier gas may be supplied at two or more locations instead of at one location. Although the flow rate of the carrier gas is not particularly limited, it is preferably 0.01 to 20 L/min, more preferably 1 to 10 L/min. In the case of diluent gas, the flow rate of diluent gas is preferably 0.001 to 2 L/min, more preferably 0.1 to 1 L/min.

(Film formation process)
In the film forming step, a film is formed on the substrate by reacting the mist or the droplets on the substrate. The reaction may be a physical reaction or a chemical reaction as long as the mist reacts on the substrate. A reaction by drying may be used, but a thermal reaction by heat is preferred, and the thermal reaction may be any reaction as long as the mist reacts with heat. In this step, the thermal reaction is usually carried out at a temperature that is not too high (for example, 600° C. or lower), but in the present invention, the temperature is preferably 300° C. or lower, more preferably 200° C. or lower. According to the film forming method of the present invention, a high-quality carbon nanotube-containing film can be obtained even at such a low temperature. The lower limit is not particularly limited as long as the object of the present invention is not hindered, but 100° C. or higher is preferable. In addition, the thermal reaction may be carried out under vacuum, under a non-oxygen atmosphere, under a reducing gas atmosphere, or under an oxygen atmosphere as long as the object of the present invention is not hindered. It is preferably carried out under atmosphere. The reaction may be carried out under atmospheric pressure, increased pressure or reduced pressure, but is preferably carried out under atmospheric pressure in the embodiment of the present invention. Note that the film thickness can be set by adjusting the film formation time.

(substrate)
The substrate is not particularly limited as long as it can support the film to be deposited. The material of the substrate is also not particularly limited as long as it does not interfere with the object of the present invention, and may be a known substrate, an organic compound, or an inorganic compound. It may be a porous structure.

A substrate having at least one film selected from a metal film, a semiconductor film, a conductive film and an insulating film formed on part or all of the surface can also be suitably used as the substrate. The constituent metal of the metal film is, for example, one selected from gallium, iron, indium, aluminum, vanadium, titanium, chromium, rhodium, nickel, cobalt, zinc, magnesium, calcium, silicon, yttrium, strontium and barium, or Two or more kinds of metals and the like are included. Examples of constituent materials of the semiconductor film include simple elements such as silicon and germanium, compounds containing elements of Groups 3 to 5 and Groups 13 to 15 of the periodic table, metal oxides, and metal sulfides. , metal selenide, or metal nitride. Examples of materials constituting the conductive film include tin-doped indium oxide (ITO), fluorine-doped indium oxide (FTO), zinc oxide (ZnO), aluminum-doped zinc oxide (AZO), and gallium-doped zinc oxide (GZO). , tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), and tungsten oxide (WO ₃ ). Preferably, it is a tin-doped indium oxide (ITO) film. Materials constituting the insulating film include, for example, aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), silicon oxynitride (Si ₄ O ₅ N ₃ ) and the like.

The means for forming the metal film, the semiconductor film, the conductive film, and the insulating film is not particularly limited, and known means may be used. Examples of such forming means include mist CVD method, sputtering method, CVD method (vapor phase growth method), SPD method (spray pyrolysis deposition method), vapor deposition method, ALD (atomic layer deposition) method, coating method ( For example, dipping, dropping, doctor blade, inkjet, spin coating, brush coating, spray coating, roll coater, air knife coating, curtain coating, wire bar coating, gravure coating, inkjet coating, etc.).

The shape of the substrate may be any shape, and is effective for all shapes. Cylindrical, helical, spherical, ring-shaped, etc. are mentioned, but in the embodiment of the present invention, the substrate is preferable. The thickness of the substrate is not particularly limited in the present invention, but is preferably 0.5 μm to 100 mm, more preferably 1 μm to 10 mm. The substrate is plate-shaped and is not particularly limited as long as it serves as a support for the film to be deposited. It may be an insulator substrate, a semiconductor substrate, a metal substrate, or a conductive substrate. In an embodiment of the present invention, the substrate is preferably a glass substrate.

Further, in the embodiment of the present invention, the film may be formed directly on the substrate, or may be formed via another layer such as a buffer layer (buffer layer) or a stress relaxation layer. The means for forming other layers such as the buffer layer (buffer layer) and the stress relaxation layer is not particularly limited, and known means may be used, but the mist CVD method is preferred in the embodiment of the present invention.

By forming a film as described above, a high-quality carbon nanotube-containing film can be obtained simply and easily, and the fluorescence peak wavelength of the obtained film can be easily adjusted. Also, the film thickness of the obtained film can be easily adjusted by adjusting the film formation time. Further, according to the preferred film forming method described above, a carbon nanotube-containing film containing unmodified (not chemically modified) carbon nanotubes and having a fluorescence peak wavelength of 500 nm or less can be obtained. can. In an embodiment of the present invention, the carbon nanotube-containing film preferably has a fluorescence peak wavelength between 300 nm and 500 nm.

The carbon nanotube-containing film can be used in various applications such as electronic components, computers or medical equipment, and is particularly useful for light emitting devices. Examples of the light-emitting device include display devices and lighting devices, and more specifically, lighting devices such as indoor and outdoor lighting, mobile phones, household appliances, outdoor displays and the like. Examples include image display devices for various electronic devices. All of them can be suitably used together with a known light source or the like by using known means or the like.

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these.

(Example 1)
1. Film Forming Apparatus A film forming apparatus 1 used in this example will be described with reference to FIG. The film forming apparatus 1 includes a carrier gas source 2a for supplying a carrier gas, a flow control valve 3a for adjusting the flow rate of the carrier gas sent from the carrier gas source 2a, and a carrier gas (dilution) for supplying the carrier gas (dilution). dilution) supply source 2b, flow control valve 3b for adjusting the flow rate of carrier gas (dilution) sent from carrier gas (dilution) supply means 2b, mist generation source 4 containing raw material solution 4a, water 5a, an ultrasonic transducer 6 attached to the bottom surface of the container 5, a hot plate 8, a substrate 10 placed on the hot plate 8, and from the mist source 4 to the vicinity of the substrate 10. and a supply pipe 9 that connects the

2. Preparation of Raw Material Solution Carbon nanotubes were mixed with 2-pyrrolidone to obtain a raw material solution. The concentration of carbon nanotubes in the solution was 0.485 g/L.

3. Preparing for film formation 2 above. The raw material solution 4 a obtained in 1. was accommodated in the mist generation source 4 . Next, as the substrate 10, a glass substrate was placed on the hot plate 8, and the hot plate 8 was operated to raise the temperature of the substrate 10 to 180.degree. Next, the flow control valves 3a and 3b are opened to set the flow rate of the carrier gas supplied from the carrier gas supply source 2a to 4.0 L/min, and the carrier gas (dilution) supplied from the carrier gas (dilution) 2b. The flow rate was adjusted to 4.0 L/min. Nitrogen was used as a carrier gas.

4. Film Formation of Phosphor Film Next, the ultrasonic oscillator 6 is vibrated at 2.4 MHz, and the vibration is propagated through the water 5a in the container 5 to the raw material solution 4a, thereby atomizing the raw material solution 4a. Mist 4b was generated. A carrier gas is supplied to the mist 4b, and the mist 4b is transported to the substrate 10 through the supply pipe 9 by the carrier gas. A carbon nanotube-containing film was formed on the substrate 10 by thermal reaction. The film formation time was 20 minutes.

5. Evaluation 4 above. The fluorescence spectrum of the carbon nanotube-containing film obtained in 1. was measured using a fluorometer. The results are shown in FIG. As can be seen from FIG. 2, the obtained phosphor film had a fluorescence peak wavelength at 467 nm.

(Example 2)
A carbon nanotube-containing film was obtained in the same manner as in Example 1, except that N-methylpyrrolidone (NMP) was used as the solvent instead of 2-pyrrolidone. The fluorescence spectrum of the obtained film was measured in the same manner as in Example 1. The resulting membrane had fluorescence peak wavelengths at 382 nm and 468 nm.

(Example 3)
A carbon nanotube-containing film was obtained in the same manner as in Example 1, except that acetone was used instead of 2-pyrrolidone as the solvent. The fluorescence spectrum of the obtained film was measured in the same manner as in Example 1. As a result, the resulting film had fluorescence peak wavelengths at 373 nm and 469 nm.

(Example 4)
A carbon nanotube-containing film was obtained in the same manner as in Example 1, except that γ-butyrolactone was used as the solvent instead of 2-pyrrolidone. The fluorescence spectrum of the obtained film was measured in the same manner as in Example 1. As a result, the obtained film had a fluorescence peak wavelength at 360 nm.

(Example 5)
A carbon nanotube-containing film was obtained in the same manner as in Example 1, except that mesitylene was used as the solvent instead of 2-pyrrolidone. The fluorescence spectrum of the obtained film was measured in the same manner as in Example 1. As a result, the resulting film had fluorescence peak wavelengths at 353 nm and 363 nm.

As is clear from Examples 1 to 5, according to the film forming method of the present invention, a high-quality carbon nanotube-containing film can be obtained simply and easily without chemically modifying the carbon nanotubes. The fluorescence peak wavelength of the resulting carbon nanotube-containing film can be easily adjusted.

INDUSTRIAL APPLICABILITY The film forming method of the present invention can simply and easily form a carbon nanotube-containing film having good fluorescence properties, and can easily adjust the fluorescence peak wavelength, so that it can be used in a wide variety of fields. , can be used in various manufacturing fields using carbon nanotube-containing films. According to the film forming method of the present invention, since carbon nanotubes can be formed at low temperature, atmospheric pressure, and non-vacuum, there are no particular restrictions on the substrate, etc., and the carbon nanotube-containing film obtained by the present invention can be formed. As a phosphor film or the like, it can be suitably used for electronic parts, electronic equipment, light-emitting devices, and the like.

REFERENCE SIGNS LIST 1 film forming apparatus 2a carrier gas source 2b carrier gas (dilution) source 3a flow control valve 3b flow control valve 4 mist generation source 4a raw material solution 4b mist 5 container 5a water 6 ultrasonic vibrator 8 hot plate 9 supply pipe 10 substrate

Claims (6)

A method of forming a carbon nanotube-containing film by reacting a raw material solution containing at least carbon nanotubes and a solvent represented by the following formula (1): is supplied, the mist is transported to a substrate by the carrier gas, and the mist is thermally reacted on the heated substrate.
[Chemical 1]

(wherein R ¹ and R ² are the same or different and represent a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group; , R ¹ and R ² may combine to form a ring.) A method of forming a carbon nanotube-containing film by reacting a raw material solution containing at least carbon nanotubes and a solvent represented by the following formula (2): is supplied, the mist is transported to a substrate by the carrier gas, and the mist is thermally reacted on the heated substrate.
[Chemical 2]

(wherein R ³ , R ⁴ and R ⁵ are each the same or different and are a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic ring represents a group, and any two groups selected from R ³ , R ⁴ and R ⁵ may combine to form a ring.) 3. The film forming method according to claim 1, wherein the atomization is performed using ultrasonic vibration. The film forming method according to any one of claims 1 to 3 , wherein the thermal reaction is performed at a temperature of 300°C or less. chemically modified A carbon nanotube-containing film comprising carbon nanotubes, characterized by having a fluorescence peak wavelength of 500 nm or less. A light-emitting device comprising at least a light source and a phosphor film, wherein said phosphor film is the carbon nanotube-containing film according to claim 5 .

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