JP2005263617A - Fullerene surface modifying material and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely carry out a surface treatment to make fullerene exist on the surface of a base material such as graphite. <P>SOLUTION: In the method of manufacturing the fullerene surface modifying base material having the surface on which fullerene exists, the base material and the fullerene are incorporated in a solvent A and are further brought into contact with a solvent B having low solubility to the fullerene. The fullerene is deposited to exist on the surface of the base material by incorporating the solvent B having low solubility to the fullerene. Because the particle diameter of the deposited fullerene is made small, the precision of the surface treatment of the base material is improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fullerene surface-modified base material in which fullerenes are present on the surface of the base material and a method for producing the same.

Since the establishment of a large-scale synthesis method for C ₆₀ in 1990, research on fullerene has been vigorously developed. Many fullerenes and fullerene derivatives have been synthesized, and the possibility of their practical use has been studied.
Among the above-mentioned studies on the possibility of practical application, application as a surface treatment agent applied to various products such as electrical and electronic equipment, automobiles, building materials, and parts of industrial machinery is highly expected as a use of fullerenes. The inventor believes that this is one of the fields. This is because fullerenes have various functions derived from extremely specific binding structures, chemical properties, electronic states, and the like. For this reason, it is considered that if the fullerenes are used as a surface treatment agent, the various functions of the fullerenes can be effectively exhibited.

In particular, when a use as the surface treatment agent is considered, a promising use is a lithium secondary battery. A lithium secondary battery has a high energy density because of its small atomic weight of lithium as an electromotive substance, and is used as a power source for electric devices such as a mobile phone and a personal digital assistant (PDA).
As a technique using a fullerene derivative in a lithium secondary battery, there is a technique in which hydrogenated C ₆₀ or hydrogenated C ₇₀ is adsorbed on the surface of graphite or carbon and used for a negative electrode (Patent Document 1). In this technique, adding SFG44 graphite dichloronaphthalene solution of a hydrogenated C _70, then the dichloronaphthalene was removed by decantation, and adsorb the hydrogenated C ₇₀ to the graphite surface (ibid p.9 lines 13 to 19).
International Publication No. 00/31811 Pamphlet

However, the surface-treated graphite hydrogenated C _70, the method of obtaining by removing the solvent by decantation tends to takes time in terms of a required operation of removal of the solution process.
In the above method, the hydrogenation C ₇₀ molecules state of being dissolved in the solvent is the graphite surface is treated by adsorption to the graphite surface. Therefore, there is a tendency that precise control of the surface treatment of the graphite (control of the particle size of the hydrogenation C ₇₀ present in the control and the graphite surface of the surface treatment amount) becomes difficult.

Furthermore, since many types of fullerenes and fullerene derivatives do not adsorb on the graphite surface, the method using decantation is considered to be a method with a very narrow range of application as a surface treatment method.
For this reason, when fullerenes are made to exist on the surface of a substrate such as graphite, it is desired to develop a new method for precisely performing surface treatment.

  In view of the above circumstances, the present inventor has intensively studied a method capable of precisely controlling the particle size and the like of fullerenes present on a substrate when the surface of the substrate is treated with fullerenes. As a result, fullerenes are precipitated by bringing solvent B in which fullerenes are dissolved into contact with solvent B having lower solubility of fullerenes than solvent A so that the precipitates are present on the substrate surface. As a result, it was found that the control of fullerenes existing on the surface of the base material can be improved, and the present invention has been completed.

That is, the first gist of the present invention is that after the base material and fullerenes are contained in the solvent A, the solvent A having a lower solubility of the fullerenes than the solvent A is further contained, and the surface of the base material is added. The present invention resides in a method for producing a fullerene surface-modified base material, which comprises producing a fullerene surface-modified base material in which the fullerenes are present.
In another aspect of the present invention, a composition α containing fullerenes and a solvent A, and a composition B containing a solvent B and a base material having a solubility of the fullerenes lower than the solvent A are prepared. Thereafter, the composition β and the composition α are brought into contact with each other to produce a fullerene surface-modified base material in which the fullerenes are present on the surface of the base material. Lies in the way.

Another aspect of the present invention is that after the fullerenes are contained in the solvent A, the solvent A having a lower solubility of the fullerenes than the solvent A is further contained, and then the base material is contained. The present invention resides in a method for producing a fullerene surface-modified base material, which comprises producing a fullerene surface-modified base material in which the above-mentioned fullerenes are present on the surface of the base material.
Furthermore, still another subject matter of the present invention resides in a fullerene surface-modified base material produced by the above-described method for producing a fullerene surface-modified base material.

Furthermore, another gist of the present invention is a fullerene surface-modified base material, wherein the base material is a carbonaceous material, and the fullerene surface-modified base material is a negative electrode material for a lithium secondary battery. Exist.
Still another subject matter of the present invention lies in a negative electrode for a lithium secondary battery, characterized by containing the above-mentioned fullerene surface-modified base material.

Still another subject matter of the present invention resides in a lithium secondary battery using the negative electrode.
In the present invention, the “fullerenes” are usually
(I) Fullerenes (b) Fullerene derivatives, fullerene-containing complexes, metal-encapsulated fullerenes (metallofullerenes) and other substances having a fullerene skeleton (c) Full-shell structures of fullerenes are directly or via at least one atom Fullerenes having a plurality of fullerene skeletons in a bonded state in the molecule;
(D) The above-mentioned (A), (B), and (C) fullerenes may be arbitrarily mixed.

Here, fullerene refers to a spherical shell-like or substantially spherical shell-like molecule composed of a plurality of carbons, and fullerene skeleton refers to a spherical shell structure or a substantially spherical shell-like structure composed of a plurality of carbons. In the spherical shell-like or substantially spherical shell-like molecule and the spherical shell-like structure or substantially spherical shell-like structure, a part of carbon constituting this may be deficient.
Further, in the present invention, “fullerenes are present on the surface of a substrate” means that the fullerenes are in the above-mentioned spherical shell structure or substantially spherical shape in a state before being used for actual use after the production of a fullerene surface-modified substrate. It means that it exists on the surface of the substrate while maintaining a shell-like structure. In other words, depending on the application in which the fullerene surface modification base material is actually used (for example, a lithium secondary battery), all or part of the above-mentioned spherical shell structure or substantially spherical shell-like structure of fullerenes is lost or destroyed. However, even such a fullerene surface-modified base material is included in the fullerene surface-modified base material in the present invention.

  In addition, for example, when the molecules of fullerene or fullerene derivative are adsorbed on the surface of the substrate alone or in the form of aggregates, the state is “fullerenes are present on the surface of the substrate”. For example, when the substrate is a porous body, the region in the hole where the fullerenes can exist is included in the substrate surface.

  According to the present invention, when the fullerenes are present on the surface of the substrate, the surface treatment can be performed precisely.

Hereinafter, embodiments of 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 within the scope of the gist of the present invention.
A major feature of the method for producing a fullerene surface-modified base material of the present invention is that the fullerenes are crystallized on the surface of the base material by contacting with a solvent B having low solubility of fullerenes. By using such a technique, there is an advantage that it is easy to uniformly modify fullerenes on the surface of the substrate. Moreover, it becomes easy to modify the fullerenes of fine particles by using the above method. For this reason, even when the addition amount (modification amount) of fullerenes is reduced, the surface modification effect by fullerenes can be sufficiently exhibited.

  In the fullerene surface-modified base material, it is considered that the effect of modification of fullerenes is expressed at the interface between the fullerenes and the base material or another substance. In this case, the specific surface area of the fullerenes can be increased if the fullerenes are atomized and present on the surface of the substrate. For this reason, even if the addition amount (modification amount) of fullerenes is reduced, it becomes easier to obtain the surface modification effect more efficiently, which is advantageous in system design.

The production method of the fullerene surface-modified base material of the present invention can be roughly divided into three. Hereinafter, the respective production methods will be described in more detail as “first production method”, “second production method”, and “third production method”.
A. First Production Method The first production method (hereinafter sometimes referred to as production method 1) is:
After containing the base material and fullerene in the solvent A,
A solvent B having a lower solubility of the fullerenes than the solvent A is further included;
A fullerene surface-modified base material in which the fullerenes are present on the surface of the base material is manufactured.

Hereinafter, the production method 1 will be described in more detail. For convenience of explanation, in the production method 1, the step of “containing the base material and fullerenes in the solvent A” includes the step 1 and “the fullerenes of the fullerenes more than the solvent A”. The process of “further containing solvent B having low solubility” is referred to as process 2.
A-1. Base material The base material is not particularly limited as long as it maintains a certain shape, and examples thereof include a plate shape and a powder shape.

When heat treatment is performed after fullerenes are present on the surface of the base material, the base material may require heat resistance. Therefore, the melting point of the base material is usually 100 ° C. or higher, preferably 200 ° C. or higher, more preferably. Is 500 ° C. or higher. On the other hand, the melting point of the substrate is usually 4000 ° C. or lower, preferably 3500 ° C. or lower, more preferably 3000 ° C. or lower.
The film thickness of the substrate in the case where the substrate is plate-like varies greatly depending on the application, but is usually 1 μm or more, preferably 10 μm or more, more preferably 100 μm or more. On the other hand, the film thickness of the substrate is usually 1 m or less, preferably 10 cm or less, more preferably 1 cm or less, and most preferably 1 mm or less.

As described above, the substrate may be in powder form. That the base material is powdery means that the base material is particulate. Here, the base material is in the form of particles when the base material is composed of a single particle (when it is a primary particle) and when the base material is formed by agglomerating a plurality of particles (secondary particles). In any case).
The particle size of the substrate in the case where the substrate is in a particulate form varies greatly depending on the use, but is usually 1 nm or more, preferably 10 nm or more, more preferably 100 nm or more, while usually 1 mm or less, preferably It is 100 μm or less, more preferably 50 μm or less.

  In addition, when the shape of the base material is indefinite (for example, when the base material is H-type steel, a plastic member for housing construction, etc.), in the corresponding part of the base material (member) covered with fullerenes The effective thickness of the substrate may be considered. Similarly, a particulate substrate having a diameter larger than 1 mm should be a mass rather than a powder (particle). For this reason, such a base material may be considered in the same manner as a plate shape. For example, for a sphere having a diameter of 1 m, it may be considered similarly to a plate-like substrate having a thickness of 1 m.

The material for the base material is not particularly limited and is appropriately selected depending on the application, and either an organic material or an inorganic material can be used. Examples of such a base material include at least one selected from the group consisting of metals, metal compounds, semiconductors, glasses, ceramics, carbonaceous materials, and polymer materials.
Examples of inorganic materials include metals (pure metals and alloys), metal compounds, semiconductors (for example, III-V semiconductors represented by Si, Ge, GaAs, II-VI semiconductors represented by Zn-Se), and glasses. And concrete, asphalt, various ceramics, various rocks, wood and other wood.

Of these, metals, metal compounds, semiconductors, glasses, and ceramics are preferred because of their high functionality.
Examples of the metal include pure metals and alloys. Specifically, Fe (iron), Cu (copper), Ni (nickel), Co (cobalt), W (tungsten), Ag (silver), Au (gold), Pt (platinum), Ti (titanium), Al (aluminum), Li (lithium), Mo (molybdenum), Cr (chromium), In (indium), Ta (tantalum), Nb (niobium), Y (yttrium), Sn (tin), Zn (zinc), A simple substance such as Pb (lead) or an alloy can be used.

  Examples of the metal compound include metal oxides, metal composite oxides, metal sulfides, metal fluorides, metal chlorides, and other ionic crystals of metal salts. Specific examples of the metal compound include iron oxide, silver oxide, aluminum oxide (alumina), copper oxide, titanium oxide (titania), silicon oxide (silica), zirconium oxide, chromium oxide, yttrium oxide, titanium carbide, and nitride. Examples thereof include titanium, tungsten carbide, tungsten nitride, chromium carbide, silicon carbide, silicon nitride, lithium cobalt composite oxide, lithium nickel composite oxide, lithium manganese composite oxide, manganese oxide, and vanadium oxide.

Examples of the semiconductor include III-V groups represented by Si, Ge, and GaAs, and II-VI semiconductors represented by Zn-Se.
Examples of the semiconductor compound include the oxide of the semiconductor, the composite oxide of the semiconductor, the sulfide of the semiconductor, the fluoride of the semiconductor, and the chloride of the semiconductor.
Examples of the glass include various silicate glasses, phosphosilicate glasses, borosilicate glasses, and quartz glasses.

Many ceramics are classified into metal oxides and metal complex oxides, but the crystal structure and composition are often more irregular. Furthermore, various ceramics can be mentioned.
Among the above inorganic materials, more specifically, Fe (iron), Cu (copper), Ni (nickel), Co (cobalt), W (tungsten), Ag (silver), Au (gold), Pt (platinum) ), Ti (titanium), Al (aluminum), In (indium), Sn (tin), Zn (zinc), Pb (lead) and other metals, iron oxides used as pigments, alumina, silica, titania, lithium Metals such as lithium cobalt composite oxide, lithium nickel composite oxide, lithium manganese composite oxide, manganese oxide (MnO), vanadium oxide (V ₂ O ₅ , V ₆ O ₁₃ ) used as a positive electrode active material for secondary batteries Compounds are particularly preferred.

  In view of the remarkable effect of the surface treatment of the present invention, Fe (iron), Cu (copper), Ni (nickel), Co (cobalt), W (tungsten), Ag (silver), Au are preferable. (Gold), Pt (platinum), Ti (titanium), Al (aluminum), In (indium), Sn (tin), Zn (zinc), Pb (lead) and other metals, lithium cobalt composite oxide, lithium nickel Metal compounds such as composite oxides and lithium manganese composite oxides.

Although it will not specifically limit if it is an organic compound as an organic material, For example, a carbonaceous substance and a polymeric material can be mentioned.
For example, when a lithium secondary battery is considered as an application of the fullerene surface modification base material, a carbonaceous material is preferably used because of its high functionality. Further, when fullerenes are used to improve the heat resistance of the polymer material, the polymer material is naturally used as the substrate.

  Examples of the carbonaceous material include graphite materials such as graphite, coal-based coke, petroleum-based coke, coal-based pitch or carbides of petroleum-based pitch, or those obtained by oxidizing these pitches, needle coke, pitch coke, and phenol resin. And crystalline cellulose. Furthermore, carbon materials, furnace black, acetylene black, pitch-based carbon fibers, and the like that are partially graphitized from the above carbonaceous materials can also be exemplified.

Among these carbonaceous substances, graphite materials such as coke and graphite are preferable, but graphite materials such as graphite are particularly preferable because they have a large capacity when used in, for example, a lithium secondary battery.
Examples of the graphite material include graphite powders such as artificial graphite and natural graphite and purified products thereof, graphitized products of conductive carbon black such as acetylene black and ketjen black, and carbon fibers such as vapor-grown carbon fibers. Among these, from the viewpoint of capacity, artificial graphite or natural graphite is preferable, and when used in a lithium secondary battery or the like, artificial graphite is particularly preferable because battery performance is easily controlled. These graphite materials may have a surface subjected to an amorphous treatment.

  Polymer materials include polyethylene, polypropylene, polymethylpentene, polybutene, polybutadiene, polystyrene, styrene butadiene resin, polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, ethylene vinyl acetate copolymer, polymethyl methacrylate, polymethyl acrylate , Polytetrafluoroethylene, ethylene polytetrafluoroethylene copolymer, polyacetal, polyamide, polycarbonate, polyphenylene ether, polysulfone, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyethersulfone, polyimide, polyamideimide, polyphenylene sulfide, polyoxy Benzoyl, polyetherketone, polyetherimide, cellulose acetate, cellulose butyrate, Carboxymethylcellulose, cellophane, celluloid, phenol resin, novolac resin, urea resin, melamine resin, benzoguanamine resin, unsaturated polyester resin, diallyl phthalate resin, alkyd resin, epoxy resin, urethane resin, and silicone resin.

Among these polymer materials, polyethylene, polypropylene, polymethylpentene, polybutene, polybutadiene, polystyrene, styrene butadiene resin, polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, and ethylene vinyl acetate are preferable from an industrial viewpoint. Polymer, polymethyl methacrylate, polymethyl acrylate, polytetrafluoroethylene, ethylene polytetrafluoroethylene copolymer, polyacetal, polyamide, polycarbonate, polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyethersulfone, polyimide, Polyamideimide, polyphenylene sulfide, polyoxybenzoyl, polyetherketone, polyetherimide, cellulose acetate Scan, a butyrate, carboxymethyl cellulose, cellophane, celluloid, phenol resin, urea resin, melamine resin, benzoguanamine resin, alkyd resin, epoxy resin, urethane resin, silicone resin.
A-2. Fullerenes As fullerenes, for example, a substance having a fullerene skeleton such as fullerene or a fullerene derivative can be used. Hereinafter, fullerenes and fullerene derivatives will be described as representative examples of these substances having a fullerene skeleton. In addition, when using fullerene and a fullerene derivative, you may use the mixture of fullerene and a fullerene derivative in arbitrary ratios within the range of the summary of this invention.

Fullerene refers to a spherical carbon molecule. The fullerene used is not limited as long as the object of the present invention is satisfied, but C ₆₀ , C ₇₀ , C ₇₄ , C ₇₆ , C ₇₈ , C ₈₀ , C ₈₂ , C ₈₄ , C ₈₆ , C ₈₈ , C ₉₀ , C can be used _{92, C 94, C 96,} C 98, C 100 , and the like. Specific examples of fullerene include C ₆₀ , C ₇₀ , C ₇₄ , C ₇₆ , C ₇₈ , C ₈₀ , C ₈₂ , C ₈₄ , C ₈₆ , C ₈₈ , C ₉₀ , C ₉₂ , C ₉₄ , C Dimers and trimers such as ₉₆ , C ₉₈ and C ₁₀₀ can also be mentioned. Needless to say, these fullerenes may be used in combination of a plurality of types in any ratio within the scope of the present invention.

Among these fullerenes, C ₆₀ , C ₇₀ , or a dimer or trimer thereof is preferable. Since C ₆₀ and C ₇₀ have high solubility in a solvent, there is an advantage that the surface treatment of the substrate can be easily performed. C ₆₀ and C ₇₀ also have an advantage that can be easily obtained industrially. Preference is given to using both C ₆₀ and C ₇₀ . It is because the uniform dispersibility with respect to the substrate surface is increased by using this combination. Even when C ₆₀ and C ₇₀ are used, it goes without saying that other fullerenes (eg, C ₇₆ , C ₇₈ , C ₈₄ ) may be contained in the fullerenes.

When C ₆₀ and C ₇₀ are used in combination, the weight ratio of C ₆₀ : C ₇₀ is usually in the range of 99: 1 to 1:99, particularly 95: 5 to 10:90, especially 90:10 to 20:80. It is preferable. By using within the above range, the interaction between C ₆₀ and C ₇₀ becomes good, and the dispersion stability is improved.
Fullerene is usually obtained by extraction and separation from fullerene-containing soot obtained by a resistance heating method, a laser heating method, an arc discharge method, a combustion method or the like. At this time, it is not always necessary to completely separate fullerene from the soot, and the content of fullerene in the soot can be adjusted within a range not impairing the performance.

Fullerenes usually have powdery properties at normal temperature (25 ° C.) and normal humidity (50% RH), and their secondary particle size is usually 10 nm or more, preferably 15 nm or more, more preferably 20 nm or more, particularly The thickness is preferably 50 nm or more, and usually 1 mm or less, preferably 500 μm or less, and more preferably 100 μm or less.
The fullerene derivative refers to a compound in which an atomic group forming a part of an organic compound or an atomic group composed of an inorganic element is bonded to at least one carbon constituting the fullerene.

As the fullerene used as the skeleton of the fullerene derivative, the above C ₆₀ , C ₇₀ , C ₇₄ , C ₇₆ , C ₇₈ , C ₈₀ , C ₈₂ , C ₈₄ , C ₈₆ , C ₈₈ , C ₉₀ , C ₉₂ , C _{94 are used.} , C ₉₆ , C ₉₈ , C _{100 and the} like can be used. That is, as the fullerene derivatives, C ₆₀ derivatives, C ₇₀ derivatives, C ₇₄ derivatives, C ₇₆ derivatives, C ₇₈ derivatives, C ₈₀ derivatives, C ₈₂ derivatives, C ₈₄ derivatives, C ₈₆ derivatives, Derivatives, C ₈₈ derivatives, C ₉₀ derivatives, C ₉₂ derivatives, C ₉₄ derivatives, C ₉₆ derivatives, C ₉₈ derivatives, and C ₁₀₀ derivatives. Needless to say, these fullerene derivatives may be used in combination at an arbitrary ratio within the scope of the present invention.

  Specific examples of other fullerene derivatives include, for example, hydrogenated fullerenes, oxidized fullerenes, hydroxylated fullerenes, halogenated (F, Cl, Br, I) fullerenes, sulfonated fullerenes, biphenylfullerenes (one or a plurality of biphenylyl groups). For example, a fullerene derivative bonded to the spherical shell structure of fullerene) can be used. The fullerene used for obtaining the fullerene derivative is not limited as long as the object of the present invention is satisfied, and any of the fullerenes specifically shown above may be used.

The fullerene derivative used in the present invention is one in which a predetermined group is bonded to one or more carbons constituting the fullerene. Of the carbons constituting the fullerene, the carbon to which a predetermined group is bonded preferably includes two carbon atoms constituting the (6-6) bond in the C ₆₀ molecule, taking the C ₆₀ molecule as an example. Can do. This is because the electron withdrawing property of the two carbon atoms forming the (6-6) bond is high. The group to be bonded may be bonded to either carbon or both carbons of the (6-6) bond, and when bonded to both carbons, when the same group is bonded to both carbons, Examples include cases where different groups are bonded, and cases where cycloaddition is performed so that both carbons are part of the ring.

Cycloaddition includes various reactions that form 3-membered, 4-membered, 5-membered, and 6-membered rings, and various fullerenes can be obtained by using those having additional substituents in the ring constituent molecules. Derivatives can be obtained.
Taking the C ₆₀ molecule as an example, the addition reaction for the formation of a three-membered ring includes (6-5) ring-opening fulleroid and (6-6) ring-closing methanofullerene. The carbon atom added in the fulleroid or methanofullerene is a methylene group, but a higher-order derivative can be obtained by substituting two hydrogens of the methylene group with a predetermined substituent. When a three-membered ring is formed by a nitrogen atom, it becomes an azafulleroid, and various derivatives are obtained by substituting groups bonded to bonds other than the two bonds bonded to the fullerene moiety among the three bonds of the nitrogen atom. Can be obtained.

Additions that form a 5-membered ring in the C ₆₀ molecule include those that form pyrazoline condensates, oxazolidine condensates, dihydrofuran condensates, pyrrolidine condensates and the like. In addition, as an addition for forming a 6-membered ring in the C ₆₀ molecule, a reaction for adding a diene is known. And a higher order derivative will be obtained by substituting the group couple | bonded with the atom which forms the said 5 or 6 membered ring. In addition, in a 5- or 6-membered ring, since the number of atoms forming the ring is large, there are a plurality of sites where substituents can be introduced, and various derivatives can be formed.

Other methods for synthesizing fullerene derivatives include the following methods.
For example, in a nucleophilic loading reaction, an alkyl group, a phenyl group, or the like can be introduced into fullerene by a reaction with an organolithium reagent, a Grignard reagent, or the like. Also, for example, according to the reaction with sodium cyanide, which is also a carbon nucleophile, a cyano group can be introduced into fullerene. Thus, the group to be introduced can be changed depending on the reagent used. The fullerene derivative synthesized by the above nucleophilic addition reaction or reaction with sodium cyanide can form a salt as an anion, but by capturing the anion with an electrophile, the 1,2-dihydrofullerene derivative and Often to do. A mono-substituted product of a 1,2-dihydrofullerene derivative can be obtained by capturing with a proton, and depending on the type of electrophile, a 1,2-dihydrofullerene derivative having a methyl group or a cyano group as the second substituent Can be obtained. In the nucleophilic addition reaction, a fullerene derivative can also be synthesized by a reaction with silyllithium or a reaction with an amine.

In addition, hydrogenated fullerene, oxidized fullerene, and fullerene hydroxide can be obtained by an oxidation reaction or a reduction reaction. It is also possible to introduce halogen such as fluorine by radical reaction.
In order to obtain a fullerene derivative, the formula weight of a group directly bonded to fullerene or a group formed by an element constituting a ring added when fullerene is cyclized is usually 1 or more, preferably 6 or more, more preferably Is 16 or more, more preferably 20 or more. If the formula weight is 6 or more, it is considered that a sterically relatively large group (for example, Li having formula weight 7) can be bonded to the fullerene skeleton, and the fullerene derivative is stabilized. Further, the upper limit of the formula weight is not particularly limited, and the above group may have a high molecular weight such as a polymer. However, from the viewpoint of steric hindrance, the formula weight is preferably 1000 or less, more preferably 500 or less, still more preferably 300 or less, and particularly preferably 200 or less.

  In order to obtain a fullerene derivative, a group directly bonded to fullerene or a group formed by an element constituting a ring added when fullerene is cyclized and added is not particularly limited. A group consisting of a hydrogen atom, an alkali metal atom, a chalcogen atom, a halogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, a characteristic group containing oxygen, a characteristic group containing sulfur, and a characteristic group containing nitrogen It is preferable that it is one selected from.

Examples of the alkali metal atom include lithium, sodium, potassium and rubidium, but lithium, sodium and potassium are preferred from the viewpoint of easy industrial synthesis.
Examples of the chalcogen atom include oxygen, sulfur, selenium, and tellurium, but oxygen and sulfur are preferable from the viewpoint of easy industrial synthesis.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine, but fluorine, chlorine, bromine and iodine are preferable from the viewpoint of easy industrial synthesis. A group containing a halogen atom such as an iodosyl group may be used.
Among the aliphatic hydrocarbon groups, examples of the alicyclic hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and isopentyl. Group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, vinyl group, 1-propenyl group, allyl group, isopropenyl group, 1-butenyl group, 2-butenyl group , 2-pentenyl group and ethynyl group. A methyl group, an ethyl group, and a propyl group are preferable from the viewpoint of easy industrial synthesis.

Among the aliphatic hydrocarbon groups, examples of the alicyclic hydrocarbon group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, and a 1-cyclohexenyl group. From the viewpoint of easy industrial synthesis, a cyclohexyl group is preferred.
Examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a cumenyl group, a benzyl group, a diphenylmethyl group, a triphenylmethyl group, a styryl group, a biphenylyl group, and a naphthyl group. From the viewpoint of easy industrial synthesis, a phenyl group, a benzyl group, and a biphenylyl group are preferable.

Examples of the heterocyclic group include a furyl group, a furfuryl group, a thienyl group, a pyrrolyl group, a pyridyl group, a piperidino group, a piperidyl group, and a quinolyl group, but a furyl group is preferred from the viewpoint of easy industrial synthesis. Group, pyridyl group.
The characteristic group containing oxygen may be any group containing oxygen, and examples thereof include a hydroxyl group, a hydrogen peroxide group, oxygen (epoxy group), and a carbonyl group. From the viewpoint of easy industrial synthesis, a hydroxyl group and oxygen are preferred.

In addition, examples of the characteristic group containing oxygen include the following.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, and a phenoxy group, but a methoxy group and an ethoxy group are preferable from the viewpoint of easy industrial synthesis. .
Examples of the carboxyl group and the ester group include a carboxyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a formyloxy group, and an acetoxy group. Preferred from the viewpoint of easy industrial synthesis, a carboxy group and an acetoxy group are preferable. It is.

  Examples of the acyl group include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, hexanoyl, octanoyl, lauroyl, palmitoyl, stearoyl, oleoyl, acryloyl Group, methacryloyl group, chloroformyl group, oxal group, cyclohexanecarbonyl group, benzoyl group, toluoyl group, naphthoyl group. From the viewpoint of easy industrial synthesis, a formyl group and an acetyl group are preferred.

Examples thereof include an acetonyl group, a phenacyl group, a salicyl group, a salicyloyl group, an anisyl group, and an anisoyl group. From the viewpoint of easy industrial synthesis, an acetonyl group and a salicyl group are preferred.
As the characteristic group containing sulfur, any group containing sulfur may be used. For example, a mercapto group, a thio group (-S-), a methylthio group, an ethylthio group, a phenylthio group, a thioformyl group, a thioacetyl group, a thiocarboxy group, Examples thereof include a dithiocarboxy group, a thiocarbamoyl group, a sulfonic acid group, a mesyl group, a benzenesulfonyl group, a toluenesulfonyl group, a tosyl group, and a sulfoamino group. A mercapto group and a sulfonic acid group are preferred from the viewpoint of easy industrial synthesis.

  As the characteristic group containing nitrogen, any group containing nitrogen can be used. For example, an amino group, a methylamino group, a dimethylamino group, an anilino group, a toluidino group, a xylidino group, a cyano group, an isocyano group, a cyanate group, an isocyanate group. Nate group, thiocyanate group, isothiocyanate group, hydroxyamino group, acetylamino group, benzamide group, succinimide group, carbamoyl group, nitroso group, nitro group, hydrazino group, phenylazo group, naphthylazo group, ureido group, ureylene group, amidino Group and guanidino group can be mentioned, but amino group, cyano group and cyanate group are preferable from the viewpoint of easy industrial synthesis.

The predetermined group described above may be further substituted with another group.
Of the above-mentioned predetermined groups, hydrogen atom, sodium, potassium, oxygen, hydroxyl group, amino group, sulfonic acid group, methyl group, ethyl group, propyl group, phenyl group, biphenylyl group, ethoxy group, fluorine are particularly preferable. , Chlorine, bromine and iodine. Among the above groups, oxygen has two bonds, and each bond bonds to a carbon atom constituting fullerene to form an epoxy group.

  Examples of particularly preferable fullerene derivatives include, for example, hydrogenated fullerene, oxidized fullerene, fullerene hydroxide, halogenated (F, Cl, Br, I) fullerene, sulfonated fullerene, biphenylfullerene (one or more biphenylyl groups are fullerenes). And at least one selected from the group consisting of fullerene derivatives bonded to the spherical shell structure), and particularly preferable in terms of improving the surface stability of the base material are fullerene oxide and fullerene hydroxide. Most preferred is fullerene oxide.

The predetermined group may be bonded to one or more carbon atoms constituting the fullerene. On the other hand, the number of the groups bonded to fullerene is usually 36 or less, preferably 20 or less, more preferably 12 or less.
The fullerene derivative is powdery at normal temperature and normal humidity (25 ° C./50% RH), and its secondary particle size is usually 10 nm or more, preferably 50 nm or more, more preferably 100 nm or more, while usually It is 1 mm or less, preferably 500 μm or less, more preferably 100 μm or less.

A-3. Process 1
In the production method 1, the base material and the fullerenes are contained in the solvent A.
(1) Solvent A
As the solvent A, a solvent that dissolves a predetermined amount of fullerenes is used. As the solvent A, a solvent having a solubility of fullerenes in the solvent A of 0.01 mg / ml or more is preferable. More preferably, the solvent A is a solvent in which the solubility of fullerenes in the solvent A is 0.1 mg / ml or more. More preferably, the solvent A is a solvent having a solubility of fullerenes in the solvent A of 1 mg / ml or more. When the amount falls within the above range, various solvents can be used as the solvent A, and the concentration of fullerenes in the solvent A can be freely controlled.

For example, the solubility of C ₆₀ in toluene or 1,2,4-trimethylbenzene, which is industrially most used as a solvent for dissolving fullerenes, is 2.9 mg / ml and 17.9 mg / ml, respectively. ml. Tetrahydrofuran is one of the promising solvents that makes it possible to reduce the particle size of fullerenes present on the substrate, but the solubility of C _{60 in} tetrahydrofuran is 0.037 mg / ml. It is. Therefore, if a solvent having the solubility of fullerenes in the above range is used as the solvent A, various solvents can be used as the solvent A.

When selecting the solvent A, it is necessary to consider the solubility of fullerenes as described above, but another important point is to select the solvent A in consideration of the difference in solubility with the solvent B. A preferable range of the solubility relationship between the solvent A and the solvent B will be described later. For example, even a solvent having a solubility of fullerenes of 0.01 mg / ml or more can be used as the solvent B. is there. That is, for example, when a solvent having a relatively high solubility of fullerenes is used as the solvent A, a solvent having a solubility of fullerenes in the vicinity of 0.01 mg / ml can be used as the solvent B. Examples of such a solvent B include tetrahydrofuran (C ₆₀ solubility: 0.037 mg / ml).

Examples of a method for determining whether or not the solvent to be used can be the solvent A include the following methods (a) to (d).
(A) A fullerene in a sufficient amount (for example, a sufficient amount that the solubility is surely 0.01 mg / ml or more) is added to the target solvent.
(B) Fullerenes are sufficiently dispersed in the solvent by sufficiently stirring or ultrasonically dispersing the solvent to which fullerenes are added. Here, specific examples of “sufficient stirring” or “sufficient ultrasonic dispersion” include stirring for 30 minutes or more, or ultrasonic dispersion for 30 minutes or more.
(C) In the dispersion obtained by the operation (b) above, undissolved fullerenes may be present in the solvent. For this reason, the said dispersion liquid is filtered.
(D) The filtrate concentration of the dispersion is measured. The concentration can be measured by a known method. For example, concentration measurement may be performed by high performance liquid chromatography or a spectrophotometer. However, in the above measurement method, the measurable concentration range may be limited. Therefore, the concentration of fullerenes in the filtrate may be estimated by diluting the filtrate to an appropriate concentration and measuring the concentration of the diluted solution.

The solubility of fullerenes in a solvent is usually measured under atmospheric pressure, normal temperature (25 ± 5 ° C.), and normal humidity (50 ± 20% RH). However, when a solvent that is in a solid state at normal temperature and normal humidity is used, the solubility may be measured at a temperature not lower than the melting point and not higher than the boiling point of the solvent used.
The following method can be mentioned as a more specific example of the said measuring method. That is, 1 g of fullerenes is added to 99 g of 1,2,4-trimethylbenzene (TMB) and stirred for 1 hour under atmospheric pressure at room temperature and humidity. Here, when 1 g of fullerenes is completely dissolved in 99 g of TMB, the solubility becomes 8.8 mg / ml. After stirring, the solution is filtered through a 0.1 μm pore size filter, and the obtained filtrate is diluted 40 times with TMB. Then, high-performance liquid chromatography measurement is performed on the diluted solution, and the solubility is calculated from the peak area.

Examples of the solvent A include benzene solvents, naphthalene solvents, heterocyclic solvents, alkane solvents, haloalkane solvents, polar solvents, and the like.
Benzene solvents include benzene, toluene, ethylbenzene, n-propylbenzene, isopropylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, xylene, o-xylene, m-xylene, p-xylene, 1 , 2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, Tetralin, o-cresol, benzonitrile, fluorobenzene, nitrobenzene, iodobenzene, bromobenzene, o-dibromobenzene, m-dibromobenzene, anisole, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, and 1,2,4 -Trichlorobenzene etc. It is possible. Among these benzene solvents, industrially preferred are benzene, toluene, xylene, 1,2,4-trimethylbenzene, and o-dichlorobenzene. Toluene and 1,2,4-trimethylbenzene are particularly preferable because they have high solubility and can be stored in a small volume when storing a fullerene solution.

Examples of the naphthalene solvent include 1-methylnaphthalene, dimethylnaphthalene, 1-phenylnaphthalene, 1-chloronaphthalene, 1-bromo-2-methylnaphthalene, and the like. Among these naphthalene solvents, industrially preferred are 1-methylnaphthalene and 1-phenylnaphthalene.
Examples of the heterocyclic solvent include tetrahydrofuran, tetrahydrothiophene, 2-methylthiophene, pyridine, quinoline, and thiophene. Among these heterocyclic solvents, industrially preferred are tetrahydrofuran and quinoline.

  Examples of alkane solvents include n-hexane, cyclohexane, n-octane, 2,2,4-trimethylpentane, n-decane, n-dodecane, n-tetradecane, decalin, cis-decalin, and trans-decalin. be able to. Among these alkane solvents, industrially preferred are n-hexane, cyclohexane, n-decane, n-dodecane, n-tetradecane, and decalin.

  Examples of haloalkane solvents include dichloromethane, chloroform, carbon tetrachloride, 1,2-dibromoethane, trichloroethylene, tetrachloroethylene, dichlorodifluoroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, and 1,1. 2,2-tetrachloroethane. Among these haloalkane solvents, industrially preferred are dichloromethane and chloroform.

Examples of the polar solvent include N-methyl-2-pyrrolidone.
Moreover, as other solvent A, carbon disulfide can be mentioned.
(2) Specific Procedure of Step 1 Step 1 is not particularly limited as long as it is a method in which the base material and the fullerenes are contained in the solvent A. A preferred specific example of step 1 includes a step of containing the fullerenes in the solvent A and then containing the base material in the solvent A.

  Furthermore, in the preferable specific example, Step 1 can be divided into Step 1-2 in which the base material is contained in the solvent A after Step 1-1 in which the fullerenes are contained in the solvent A. More specifically, in step 1-1, fullerenes are usually dissolved in the solvent A. In Step 1-2, the base material is usually charged into a solution in which fullerenes are dissolved in the solvent A.

(2-1) Step 1-1
<Quantity ratio of each component>
The amount ratio between the fullerenes and the solvent A is not particularly limited. The type of the fullerenes and the solvent A to be used, the method of bringing them into contact with each other, and the removal of the solvent A and the solvent B when separating the base material described later. It can be appropriately selected depending on the presence or absence and the method thereof. Usually, the ratio of the fullerenes to the solvent A may be appropriately adjusted according to the particle size of the fullerenes to be obtained within a range that does not hinder the characteristics and the process. In particular, when a fullerene is dissolved in the solvent A to form a solution, by selecting a fullerene ratio from a wide range, a dilute solution to a concentrated solution, a saturated solution, and further an undissolved fullerene. It is possible to obtain a solution in a desired state up to a saturated solution in which a solid phase system exists.

  Specifically, the ratio of fullerenes to the solvent A is usually 0.002% by weight or more, preferably 0.005% by weight or more, more preferably 0.000% by weight or more in consideration of uniformity of surface treatment, industrial productivity, and the like. 01 wt% or more, more preferably 0.05 wt% or more. On the other hand, from the viewpoint of suppressing undissolved fullerenes and reduction in uniformity, the upper limit is usually 10% by weight or less, preferably 5% by weight or less, more preferably 2% by weight or less. If it is the said range, fullerenes will become easy to melt | dissolve in the solvent A uniformly.

  Further, the ratio of fullerenes to solvent A is usually 0.0176 mg / ml or more, preferably 0.044 mg / ml or more, more preferably 0.088 mg / ml in consideration of uniformity of surface treatment, industrial productivity, and the like. ml or more, more preferably 0.44 mg / ml or more. On the other hand, from the viewpoint of suppressing undissolved fullerenes and reduction in uniformity, the upper limit is usually 88 mg / ml or less, preferably 44 mg / ml or less, more preferably 17.6 mg / ml or less. If it is the said range, fullerenes will become easy to melt | dissolve in the solvent A uniformly.

  In addition, when fullerenes are dissolved in the solvent A, it is most preferable to carry out in a binary system of the solvent A and fullerenes from the viewpoint of improving the dissolution rate, but other components are required in the product stage. Other components may be added depending on the nature and the like. In that case, the amount ratio of the other components used to the solvent A is usually 99.9% by weight or less, preferably 99% by weight or less, and usually 0.01% by weight or more, preferably 0.1% by weight or more, More preferably, the content is 1% by weight or more.

<Method of dissolution>
The method for dissolving the fullerenes in the solvent A is not particularly limited, but usually the fullerenes may be mixed with the solvent A. When the fullerenes are mixed with the solvent A, it is preferable to dissolve the fullerenes in the solvent A using an appropriate dispersion method. Specific examples of the dispersion method include a stirrer, a blender, a homogenizer, a valve homogenizer, an ultrasonic homogenizer, an ultrasonic disperser, a static mixer, a stirring mixer, a planetary mixer, a ball mill, a sand mill, a roll mill, a disc mill, and a twin-screw kneader. Examples of the method include stirring, mixing, dispersion, and kneading. Thereby, it becomes easy to contain fullerenes uniformly in the solvent A in a short time. In particular, when the amount ratio of fullerenes to solvent A is high, or when the viscosity of solvent A is high, non-uniformization of fullerenes in solvent A is likely to occur due to poor contact (mixing). Is preferably applied.

  The temperature at which the fullerenes and the solvent A are mixed is not particularly limited, but is usually 10 ° C or higher, preferably 20 ° C or higher, and usually 200 ° C or lower, preferably 180 ° C or lower, more preferably 100 ° C. The following. In the case where the melting point of the solvent A is higher than room temperature, it is preferable to melt the solvent A by heating to obtain a liquid state, and then dissolve the fullerenes in the above-described manner.

The time for mixing the fullerenes and the solvent A is not particularly limited, but is usually 20 minutes or longer, preferably 60 minutes or longer, and usually 72 hours or shorter, preferably 24 hours or shorter, more preferably 12 hours. The following.
<Composition obtained by mixing fullerenes and solvent A>
By the above operation, a liquid composition in which fullerenes are usually dissolved in the solvent A is obtained. In this composition, when a part of fullerenes is not dissolved but remains in the container, it may be used by separating and purifying the undissolved portion. Examples of the separation and purification method include methods such as filtration and centrifugation.

(2-2) Step 1-2
<Quantity ratio of each component>
The amount ratio between the liquid composition obtained by dissolving the fullerenes obtained in step 1-1 in the solvent A and the base material is not particularly limited, and depends on the surface modification amount of the fullerenes to the base material. Adjust it.

  Specifically, in the case where the liquid composition in which fullerenes are dissolved in the solvent A is 100 parts by weight, the ratio of the base material to the composition is usually 1 part by weight or more in consideration of industrial productivity. The amount is preferably 5 parts by weight or more, more preferably 30 parts by weight or more, and still more preferably 40 parts by weight or more. On the other hand, from the viewpoint of suppressing the decrease in uniformity, the upper limit is usually 400 parts by weight or less, preferably 200 parts by weight or less, more preferably 100 parts by weight or less. If it is the said range, since it becomes easy to disperse | distribute a base material uniformly in the liquid composition which dissolved fullerenes in the solvent A, the uniformity of a composition becomes favorable.

<Method of including base material>
There is no particular limitation on the method of incorporating the base material into the liquid composition in which fullerenes are dissolved in the solvent A. Usually, the substrate is dispersed in a liquid composition in which fullerenes are dissolved in the solvent A. Here, when the substrate has a plate-like or relatively large lump property, the fullerenes are used as a solvent rather than dispersing the substrate in a liquid composition obtained by dissolving fullerenes in the solvent A. The operation of charging the substrate into the liquid composition dissolved in A is performed. In addition, when a base material is plate shape, you may use the method of apply | coating the liquid composition which dissolved fullerenes in the solvent A to a base material.

Moreover, the following method can be mentioned as an example of the other method of containing a base material in the liquid composition which dissolved fullerenes in the solvent A. That is, a dispersion in which the base material is previously dispersed in the solvent A is prepared. The dispersion may be contained in a liquid composition in which the fullerenes are dissolved in the solvent A.
Here, as a dispersion method, a method of mixing a liquid composition in which fullerenes are dissolved in the solvent A and a base material or a dispersion liquid in which the base material is dispersed is usually used.

  When mixing the liquid composition in which fullerenes are dissolved in the solvent A and the base material (or the dispersion liquid in which the base material is dispersed), it is preferable to use an appropriate dispersion method. Specific examples of the dispersion method include a stirrer, blender, homogenizer, valve homogenizer, ultrasonic homogenizer, ultrasonic disperser, static mixer, stirring mixer, planetary mixer, ball mill, sand mill, roll mill, disc mill, and twin-screw kneader. Examples of the method include stirring, mixing, dispersion, and kneading. This makes it easier to obtain a uniform dispersion in a short time. In particular, when the density of the base material and the solvent A are greatly different, it is preferable to apply an appropriate dispersion method because the composition in the composition tends to be non-uniform due to sedimentation of the base material.

  The temperature at the time of mixing the liquid composition in which fullerenes are dissolved in the solvent A and the base material (or the dispersion liquid in which the base material is dispersed) is not particularly limited, but is usually 0 ° C. or higher, preferably Is 20 ° C. or higher, and is usually 200 ° C. or lower, preferably 180 ° C. or lower, more preferably 100 ° C. or lower. In addition, when the melting point of the solvent A is higher than normal temperature, it is preferable to disperse the substrate by the above-described method in the state where the solvent A is melted by heating.

The time for mixing the liquid composition in which fullerenes are dissolved in the solvent A and the base material (or the dispersion liquid in which the base material is dispersed) is not particularly limited, but usually 10 minutes or more, preferably Is 20 minutes or longer, and usually 72 hours or shorter, preferably 24 hours or shorter, more preferably 12 hours or shorter.
A-4. Process 2
In step 2, a solvent B having a lower solubility of fullerenes than the solvent A is further contained.

(1) Solvent B
As the solvent B, a solvent having lower solubility of fullerenes than the solvent A is used. Usually, when a solvent B having a solubility of fullerenes lower than that of the solvent A is brought into contact with the base material dispersed in the solvent A in which the fullerenes are dissolved, the contact between the fullerenes and the solvent B causes Precipitation of fullerenes dissolved in the solution begins. The precipitated fullerenes adhere to the substrate surface. In this case, since the precipitated fullerenes generally have a small particle size, the fullerenes having a small particle size are present on the substrate surface.

The solvent B is sufficient if the solubility of fullerenes is lower than that of the solvent A. Specifically, the solubility of fullerenes in the solvent A and the solubility of fullerenes in the solvent B are (solubility of fullerenes in the solvent B) / (solubility of fullerenes in the solvent A) ≦ 0. It is preferable that the relationship is .5.
From the viewpoint of satisfactorily precipitating fullerenes, more preferably, (solubility of fullerenes in solvent B) / (solubility of fullerenes in solvent A) ≦ 0.3, and more preferably (fullerenes of (Solubility in solvent B) / (solubility of fullerenes in solvent A) ≦ 0.25, more preferably (solubility of fullerenes in solvent B) / (solubility of fullerenes in solvent A) ≦ 0 .01, particularly preferably (solubility of fullerenes in solvent B) / (solubility of fullerenes in solvent A) ≦ 1 × 10 ⁻⁴ , most preferably (solubility of fullerenes in solvent B) ) / (Solubility of fullerenes in solvent A) ≦ 1 × 10 ⁻⁵ . In addition, when comparing the solubility of the fullerenes of the solvent A and the solubility of the fullerenes of the solvent B, the comparison may be performed under the same conditions (for example, the same temperature).

On the other hand, depending on the type of solvent B, there is a solvent that does not dissolve fullerenes, so the lower limit of (solubility of fullerenes in solvent B) / (solubility of fullerenes in solvent A) is zero.
Further, when the solvent A and the solvent B are in a phase-separating relationship, the precipitation of fullerenes tends not to proceed, so that the solvent A and the solvent B are preferably compatible with each other.

Examples of the solvent B include a solvent having a solubility of fullerenes of less than 0.01 mg / ml. As a method for determining whether or not the solvent to be used can be the solvent B (measurement of the solubility of fullerenes in the solvent B), the same method as in the case of the solvent A may be used.
However, as the solvent B, a solvent having a solubility of fullerenes of less than 0.01 mg / ml is not necessarily used. As described above, in the present invention, a solvent having a relatively high solubility of fullerenes is used as solvent A, and a solvent having a relatively low solubility of fullerenes is used as solvent B. That is, the difference in solubility of fullerenes between the solvent A and the solvent B is important. Therefore, even if the solubility of fullerenes is 0.01 mg / ml or more, it can be used as the solvent B. More specifically, even if the solubility of fullerenes is about 0.01 mg / ml, it can be used as the solvent B.

Examples of the solvent B include alcohol solvents (specifically monovalent or polyhydric alcohol solvents), ketone solvents, ether solvents, ester solvents, acetonitrile, dimethyl sulfoxide (DMSO), dimethylformamide (DMF). ), Nitromethane, nitroethane, and water.
Examples of the monovalent or polyhydric alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerin, and dipropylene glycol.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isopropyl ketone, and methyl isobutyl ketone.
Examples of ether solvents include dimethyl ether, diethyl ether, dibutyl ether, tetrahydrofuran (THF), and the like.
Examples of ester solvents include ethyl acetate, butyl acetate, propyl acetate and the like.

Of these solvents B, methanol, ethanol, 2-propanol, butanol, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, tetrahydrofuran (THF), acetonitrile, nitromethane, nitroethane, and water are preferable from an industrial viewpoint. It is.
Methanol, ethanol, 2-propanol, and acetone are more preferable as the solvent B from the viewpoint of industrially inexpensive and low viscosity, and methanol and 2-propanol are more preferable.

(2) Specific procedure of step 2 The specific method of step 2 is to deposit the fullerenes by containing (contacting) the solvent B in a solvent A containing a base material and fullerenes. There is no particular limitation as long as it can be performed.
<Quantity ratio of each component>
The amount ratio of the solvent containing the base material and the fullerenes in the solvent A (more specifically, the composition containing the fullerenes, the base material and the solvent A) and the solvent B is not particularly limited, and the fullerene to be used. And the combination of solvent A and solvent B, the method of containing them, and further, the presence or absence of removal of solvent A and solvent B when separating the substrate described later, the method thereof, and the like can be selected as appropriate. . Usually, the amount of the solvent B may be appropriately adjusted according to the solubility of the fullerenes in the solvent A.

  Specifically, when the composition obtained by dissolving the fullerenes obtained in Step 1-1 above in Solvent A is 100 parts by weight, the ratio of the solvent B to the composition is stable surface treatment. In view of the properties, it is usually 50 parts by weight or more, preferably 100 parts by weight or more, more preferably 300 parts by weight or more, still more preferably 500 parts by weight or more, particularly preferably 1000 parts by weight or more, and most preferably 1500 parts by weight or more. And On the other hand, from the viewpoint of industrial productivity, the upper limit is usually 10,000 parts by weight or less, preferably 7500 parts by weight or less, more preferably 5000 parts by weight or less.

In addition, this precipitation process may use multiple types of solvent B from viewpoints, such as control of precipitation rate. <Contact method>
The method for bringing the composition containing the fullerenes, the solvent A and the base material into contact with the solvent B is not particularly limited. For example, the composition containing the fullerenes, the base material and the solvent A obtained in Step 1; Solvent B may be mixed. Usually, as a mixing method, a case where a solvent B is added to a composition containing a fullerene, a base material and a solvent A and mixing, and a composition containing a fullerene, a base material and the solvent A in a solvent B are mixed. Two methods of adding and mixing can be considered.

When the solvent B is added to the composition containing the fullerenes, the base material and the solvent A and mixed, it is preferable that the solvent B is uniformly present in the composition. Similarly, when adding and mixing a composition containing fullerenes, a base material and the solvent A to the solvent B, it is preferable that the composition be present uniformly in the solvent B.
When the solvent B is added to and mixed with the composition containing the fullerenes, the base material and the solvent A, the solvent B can be mixed into the composition at a time so that the solvent B exists uniformly. For example, it is preferable to add a predetermined amount (small amount) of solvent B continuously or intermittently to the composition. As a specific method for continuously or intermittently adding such a predetermined amount of solvent B, for example, the entire amount of solvent B used for the composition is continuously added to the composition little by little. Examples thereof include a method of adding the solvent and a method of intermittently adding the solvent B into the composition using an appropriate addition method.

  Similarly, when the composition containing fullerenes, the base material and the solvent A is added to the solvent B and mixed, the composition is mixed with the solvent B at a time in order to allow the composition to exist uniformly. For example, it is preferable to add a predetermined amount (a small amount) of the composition to the solvent B continuously or intermittently. As a specific method for continuously or intermittently adding such a predetermined amount of the composition, for example, the whole amount of the composition used for the solvent B is continuously added to the solvent B little by little. Examples thereof include a method of adding, and a method of intermittently adding the composition to the solvent B using an appropriate addition method.

Used in a method of adding and mixing solvent B to a composition containing fullerenes, a base material and solvent A, or a method of adding and mixing a composition containing fullerenes, a base material and solvent A to solvent B Specific examples of the addition method include a method using a dropping funnel, an automatic dropping device, a metering pump, and the like.
The addition time is not particularly limited, and is usually 5 minutes or more, preferably 10 minutes or more, more preferably 30 minutes or more, and even more preferably 1 hour or more in consideration of the deposition rate and surface modification uniformity. . On the other hand, from the viewpoint of industrial productivity, the upper limit is usually 20 hours or less, preferably 10 hours% or less, more preferably 5 hours or less.

In the case where the solvent B is added to the composition containing the fullerenes, the base material and the solvent A and mixed, it is preferable to uniformly mix the composition when the solvent B is added. Similarly, in the case where the composition containing fullerenes, the base material and the solvent A is added to the solvent B and mixed, it is preferable that the solvent B is mixed uniformly when the composition is added.
In addition, in the case where the solvent B is added to and mixed with the composition containing the fullerenes, the base material and the solvent A, the solvent B is added in total for the purpose of further compatibilizing the solvent A and the solvent B. It is preferable to continue mixing for a predetermined time later. Similarly, in the case where a composition containing fullerenes, a base material and a solvent A is added to the solvent B and mixed, the fullerenes and the base material are used for the purpose of further compatibilizing the solvent A and the solvent B. It is preferable to continue mixing for a predetermined time after the total amount of the composition containing the solvent A is added. Here, the mixing time is usually 10 minutes or longer, preferably 20 minutes or longer, and usually 10 hours or shorter, preferably 5 hours or shorter, more preferably 2 hours or shorter.

  Specific examples of the mixing method include a stirrer, blender, homogenizer, valve homogenizer, ultrasonic homogenizer, ultrasonic disperser, static mixer, stirring mixer, planetary mixer, ball mill, sand mill, roll mill, disc mill, and twin-screw kneader. Examples of the method include stirring, mixing, dispersion, and kneading. This makes it easier to obtain a uniformly treated fullerene surface-modified base material. In particular, when the solubility of fullerenes in the solvent A is low, or when the viscosity of the solvent A and the solvent B is high, the composition in the composition is likely to become non-uniform due to poor mixing, so an appropriate mixing method is applied. It is preferable.

When the solvent B is contained in the composition containing the fullerenes, the base material and the solvent A obtained in step 1 (similarly, when the solvent B contains the composition containing the fullerenes, the base material and the solvent A) ) Is not particularly limited, but is usually 0 ° C. or higher, preferably 20 ° C. or higher, and is usually 200 ° C. or lower, preferably 180 ° C. or lower, more preferably 100 ° C. or lower.
<Separation method of fullerene surface modified base material>
By using the above method, a fullerene surface-modified base material in which fullerenes are present on the surface of the base material can be obtained. Here, it is preferable to separate the substrate from the solvent A and the solvent B.

  In the case where the substrate is separated from the solvent A and the solvent B, the separation method is not particularly limited. As the separation method, filtration, centrifugation, solvent drying, decantation and the like are usually applied. In particular, when the boiling points of the solvent A and the solvent B are different, separation by filtration is preferable because the solvent composition in the dispersion is changed by drying and may affect the surface modification state of fullerenes. When the substrate is plate-shaped, depending on the size and shape of the substrate, a method for separating the fullerene surface-modified substrate by filtration may not be appropriate. In such a case, the solvent A and the solvent B may be removed using decantation.

Note that the fullerene surface-modified base material separated by filtration may be washed with the solvent B.
<Drying method of fullerene surface modified base material>
When there are the solvent A and the solvent B remaining on the fullerene surface-modified base material obtained by the above operation, it is preferable to remove the solvent A and the solvent B, but this removal method is not particularly limited. . Usually, it is carried out by heat drying, reduced pressure drying, freeze drying or the like.

The temperature during drying is not particularly limited, but is usually 40 ° C. or higher, preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and usually 200 ° C. or lower, preferably 180 ° C. or lower, more preferably 100 ° C. or lower. The drying time is not particularly limited, but is usually 1 hour or longer, preferably 2 hours or longer, and usually 10 hours or shorter, preferably 5 hours or shorter.
The pressure in the case of drying under reduced pressure is usually 1.33 × 10 ² Pa (1 torr) or more and 1.01 × 10 ⁵ Pa (760 torr) or less. The drying atmosphere is usually performed in the air, but may be performed in an inert gas atmosphere such as nitrogen or argon.

B. Second Production Method A second production method (hereinafter referred to as production method 2) of the fullerene surface-modified base material is:
After preparing a composition α containing fullerenes and a solvent A, and a composition β containing a solvent B and a base material having lower solubility of the fullerenes than the solvent A,
Contacting the composition β and the composition α,
A fullerene surface-modified base material in which the fullerenes are present on the surface of the base material is manufactured.

This production method is a method in which a composition β is brought into contact with the composition α, whereby the fullerenes in the composition α are precipitated on the base material by the action of the solvent B to obtain a fullerene surface-modified base material.
B-1. The same substrate as described in the above production method 1 can be used.
B-2. Fullerenes The same as those described in the above production method 1 can be used.
B-3. Solvent A, Solvent B
The thing similar to what was demonstrated by the said manufacturing method 1 can be used.
B-4. Production of Composition β Containing Substrate and Solvent B <Quantity Ratio of Each Component>
The amount ratio between the solvent B and the substrate is not particularly limited, and may be adjusted according to the amount of the solvent A determined by the surface modification amount of the fullerenes to the substrate.

  Specifically, when the solvent B is 100 parts by weight, the ratio of the base material to this is usually 50 parts by weight or more, preferably 100 parts by weight or more, more preferably from the viewpoint of suppressing a decrease in uniformity. Is 300 parts by weight or more, more preferably 500 parts by weight or more, and particularly preferably 1000 parts by weight or more. On the other hand, in consideration of industrial productivity, the upper limit is usually 10,000 parts by weight or less, preferably 7500 parts by weight or less, more preferably 5000 parts by weight or less. If it is the said range, when it will contain the composition of the below-mentioned fullerenes and the solvent A, it will become easy to surface-modify the fullerenes uniformly to a base material.

<Distribution method>
The technique for incorporating the base material into the solvent B is not particularly limited. Usually, the solvent B and the base material are mixed to form a composition in which the base material is dispersed in the solvent B. When mixing the solvent B and the substrate, it is preferable to disperse the substrate in the solvent B using an appropriate dispersion method.
Specific examples of the dispersion method include a stirrer, a blender, a homogenizer, a valve homogenizer, an ultrasonic homogenizer, an ultrasonic disperser, a static mixer, a stirring mixer, a planetary mixer, a ball mill, a sand mill, a roll mill, a disc mill, and a twin-screw kneader. Examples of the method include stirring, mixing, dispersion, and kneading. This makes it easy to obtain a uniform dispersion in a short time. In particular, when the densities of the base material and the solvent B are greatly different, it is preferable to apply an appropriate dispersion method because the composition in the composition is likely to be non-uniform due to sedimentation of the base material.

  The temperature at which the base material and the solvent B are mixed is not particularly limited, but is usually 0 ° C. or higher, preferably 20 ° C. or higher, and usually 200 ° C. or lower, preferably 180 ° C. or lower, more preferably 100 ° C. The following. In addition, when the melting point of the solvent B is higher than room temperature, it is preferable to melt the solvent B by heating to obtain a liquid state, and then dissolve the fullerenes in the liquid state by the above-described method.

Further, the mixing time of the base material and the solvent B is not particularly limited, but is usually 20 minutes or more, preferably 60 minutes or more, and usually 72 hours or less, preferably 24 hours or less, more preferably 12 hours. The following.
B-5. Production of Composition α Containing Fullerenes and Solvent A Composition α containing Fullerenes and Solvent A in a manner similar to the method described in “Step 1-1” of Production Method 1 (more specifically, A solution in which fullerenes are dissolved in the solvent A) can be produced.

B-6. Step of contacting composition β and composition α In production method 2, the composition β in which the base material is dispersed in the solvent B and the composition α in which fullerenes are dissolved in the solvent A are brought into contact with each other. Precipitation starts when the fullerenes dissolved in A come into contact with the solvent B having low solubility, and the fullerenes are modified on the surface of the base material, thereby producing a fullerene surface-modified base material.

Hereinafter, a specific method for bringing the composition β into contact with the composition α will be described.
<Contact method>
The method for bringing the composition β and the composition α into contact with each other is not particularly limited. Usually, the composition α may be mixed with the composition β, or the composition β may be mixed with the composition α.
When the composition α is mixed with the composition β, it is preferable that the composition α is uniformly present in the composition β. Here, in order to uniformly exist, the composition α may be mixed into the composition β at one time. For example, a predetermined amount (small amount) of the composition α may be continuously or intermittently mixed. It is preferable to add it inside. As a specific method for continuously or intermittently adding such a predetermined amount of the composition α, for example, the total amount of the composition α used with respect to the composition β is continuously little by little. Examples thereof include a method of adding to β and a method of intermittently adding the composition α into the composition β using an appropriate addition method.

  Similarly, when the composition β is mixed with the composition α, the composition β is preferably uniformly present in the composition α. Here, in order to uniformly exist, the composition β may be mixed into the composition α at a time. For example, a predetermined amount (small amount) of the composition β may be continuously or intermittently mixed. It is preferable to add it inside. As a specific method for continuously or intermittently adding such a predetermined amount of the composition β, for example, the composition β used for the composition α is continuously little by little. Examples thereof include a method of adding to α and a method of intermittently adding the composition β into the composition α by using an appropriate addition method.

As a specific example of the addition method used when mixing the composition α with the composition β or mixing the composition β with the composition α, for example, a method using a dropping funnel, an automatic dropping device, a metering pump, or the like Is mentioned.
The addition time is not particularly limited, and is usually 5 minutes or more, preferably 10 minutes or more, more preferably 30 minutes or more, and even more preferably 1 hour or more in consideration of the deposition rate and surface modification uniformity. . On the other hand, from the viewpoint of industrial productivity, the upper limit is usually 20 hours or less, preferably 10 hours or less, more preferably 5 hours or less.

When the composition α is added to the composition β and mixed, it is preferable that the composition β is mixed uniformly during the addition of the composition α. Similarly, when the composition β is added to the composition α and mixed, it is preferable that the composition α is mixed uniformly during the addition of the composition β.
When the composition α is added to the composition β and mixed, the total amount of the composition α is added for the purpose of further compatibilizing the composition α and the composition β, followed by mixing for a predetermined time. It is preferable to continue. Similarly, in the case where the composition β is added to the composition α and mixed, for the purpose of further compatibilizing the composition β and the composition α, the total amount of the composition β is added for a predetermined time. It is preferable to continue mixing. Here, the mixing time is usually 10 minutes or longer, preferably 20 minutes or longer, and usually 10 hours or shorter, preferably 5 hours or shorter, more preferably 2 hours or shorter.

  Specific examples of the mixing method include a stirrer, blender, homogenizer, valve homogenizer, ultrasonic homogenizer, ultrasonic disperser, static mixer, stirring mixer, planetary mixer, ball mill, sand mill, roll mill, disc mill, and twin-screw kneader. Examples of the method include stirring, mixing, dispersion, and kneading. This makes it easier to obtain a uniformly treated fullerene surface-modified base material. In particular, when the solubility of fullerenes in the solvent A is low, or when the viscosity of the solvent A and the solvent B is high, the composition in the composition is likely to become non-uniform due to poor mixing, so an appropriate mixing method is applied. It is preferable.

The temperature when the composition β contains the composition α (similarly when the composition α contains the composition β) is not particularly limited, but is usually 0 ° C. or higher, preferably 20 ° C. or higher, while usually 200 C. or lower, preferably 180.degree. C. or lower, more preferably 100.degree. C. or lower.
<Separation method of fullerene surface modified base material>
By using the above method, a fullerene surface-modified base material in which fullerenes are present on the surface of the base material can be obtained. Here, it is preferable to separate the fullerene surface modification base material from the solvent A and the solvent B. When separating the fullerene surface-modified base material from the solvent A and the solvent B, the separation method is not particularly limited. A specific method may be the same as in manufacturing method 1.

<Drying method of fullerene surface modified base material>
When there are the solvent A and the solvent B remaining on the fullerene surface-modified base material obtained by the above operation, it is preferable to remove the solvent A and the solvent B, but this removal method is not particularly limited. . A specific method may be the same as in manufacturing method 1.
C. Third Production Method A third production method (hereinafter referred to as production method 3) of the fullerene surface-modified base material is as follows.
After the fullerenes are contained in the solvent A, the solvent A having a lower solubility of the fullerenes than the solvent A is further contained,
After that, a fullerene surface modified base material in which the fullerenes are present on the surface of the base material is produced by containing the base material.

In this production method, by adding solvent B to solvent A in which fullerenes are dissolved, a state in which fine particles of fullerenes are dispersed in a solvent is created in advance, and a base material is added to the above to the surface of the base material. This is a method of attaching fine particles of fullerenes.
C-1. The same substrate as described in the above production method 1 can be used.
C-2. Fullerenes The same as those described in the above production method 1 can be used.
C-3. Solvent A, Solvent B
The thing similar to what was demonstrated by the said manufacturing method 1 can be used.
C-4. Method for Producing Solvent A Containing Fullerenes As such a method, for example, any method that dissolves fullerenes in solvent A may be used, and the same method as that described in Production Method 1 and Production Method 2 may be used. Can be used.
C-5. In the production method 3, after the fullerenes are contained in the solvent A, the solvent B having a lower solubility of the fullerenes than the solvent A is further contained.

<Method of containing (contacting) solvent B>
The method for containing (contacting) the solvent B with the solvent A containing fullerenes is not particularly limited. Usually, the solvent B may be mixed with the solvent A containing fullerenes, or the solvent A containing fullerenes may be mixed with the solvent B.
When mixing the solvent B with the solvent A containing fullerenes, the solvent B is preferably present uniformly in the solvent A containing fullerenes. In order to make it exist uniformly here, the solvent B may be mixed at once with the solvent A containing fullerenes. For example, a predetermined amount (small amount) of the solvent B is continuously or intermittently added. It is preferable to add to the solvent A containing fullerenes. As a specific method for continuously or intermittently adding such a predetermined amount of solvent B, for example, the total amount of solvent B used for solvent A containing fullerenes may be slightly increased continuously. A method of adding the solvent B to the solvent A containing the fullerenes or a method of intermittently adding the solvent B to the solvent A containing the fullerenes using an appropriate addition method can be exemplified.

  When mixing the solvent A containing fullerenes with the solvent B, it is preferable that the solvent A containing fullerenes be present uniformly in the solvent B. In order to make it exist uniformly here, the solvent A containing fullerenes may be mixed in the solvent B at a time. For example, the solvent A containing a predetermined amount (small amount) of fullerenes is continuously added. It is preferable to add to the solvent B intermittently or intermittently. As a specific method for continuously or intermittently adding the solvent A containing a predetermined amount of fullerenes, for example, the total amount of the solvent A containing fullerenes to be used with respect to the solvent B is used. Examples thereof include a method of continuously adding to the solvent B little by little, and a method of intermittently adding the solvent A containing fullerenes to the solvent B using an appropriate addition method.

Specific examples of the addition method include a method using a dropping funnel, an automatic dropping device, a metering pump, and the like.
The addition time is not particularly limited, and is usually 5 minutes or more, preferably 10 minutes or more, more preferably 30 minutes or more, and even more preferably 1 hour or more in consideration of the deposition rate and surface modification uniformity. . On the other hand, from the viewpoint of industrial productivity, the upper limit is usually 20 hours or less, preferably 10 hours or less, more preferably 5 hours or less.

In the case of mixing the solvent B with the solvent A containing fullerenes, it is preferable that the solvent A containing fullerenes be mixed uniformly during the addition of the solvent B. Similarly, when mixing solvent A containing fullerenes with solvent B, it is preferable to mix solvent B uniformly during addition of solvent A containing fullerenes.
In addition, in the case of mixing the solvent B with the solvent A containing fullerenes, the mixing is continued for a predetermined time after adding the whole amount of the solvent B for the purpose of further compatibilizing the solvent B and the solvent A. Is preferred. Similarly, in the case of mixing the solvent A containing fullerenes with the solvent B, for the purpose of further compatibilizing the solvent A and the solvent B, etc., after adding the whole amount of the solvent A containing fullerenes, It is preferable to continue mixing for a predetermined time. Here, the mixing time is usually 10 minutes or longer, preferably 20 minutes or longer, and usually 10 hours or shorter, preferably 5 hours or shorter, more preferably 2 hours or shorter.

  Specific examples of the mixing method include a stirrer, blender, homogenizer, valve homogenizer, ultrasonic homogenizer, ultrasonic disperser, static mixer, stirring mixer, planetary mixer, ball mill, sand mill, roll mill, disc mill, and twin-screw kneader. Examples of the method include stirring, mixing, dispersion, and kneading. This makes it easier to obtain a uniform dispersion. In particular, when the solubility of fullerenes in the solvent A is low, or when the viscosity of the solvent A and the solvent B is high, the composition in the composition is likely to become non-uniform due to poor mixing, so an appropriate mixing method is applied. It is preferable.

The temperature when the solvent A containing the fullerenes contains the solvent B (similarly, when the solvent B contains the solvent A containing fullerenes) is not particularly limited, but is usually 0 ° C. or higher, preferably 20 ° C. On the other hand, it is usually 200 ° C. or lower, preferably 180 ° C. or lower, more preferably 100 ° C. or lower.
In addition, what is necessary is just to let the quantity ratio of the solvent A and the solvent B containing fullerenes be the range demonstrated by the manufacturing method 1 or the manufacturing method 2.

C-6. Step of containing base material In production method 3, the base material is further contained in the composition containing fullerenes, solvent A, and solvent B obtained as described above. That is, by including the base material and bringing the base material into contact with the composition containing the fullerenes, the solvent A, and the solvent B, by precipitation in the composition containing the fullerenes, the solvent A, and the solvent B. The obtained fullerenes are attached to the substrate surface.

  The technique for containing (contacting) the base material in the composition containing the fullerenes, the solvent A, and the solvent B is not particularly limited. Usually, the substrate may be mixed with the composition containing the fullerenes, the solvent A, and the solvent B, or the composition containing the fullerenes, the solvent A, and the solvent B may be mixed with the substrate. Here, when performing the said mixing, a base material may be used as it is, and a base material may be disperse | distributed to a predetermined solvent (for example, solvent B). In addition, when a base material is plate shape, it uses the technique of dipping apply | coating a base material to the composition containing fullerenes, the solvent A, and the solvent B, or apply | coating directly to a plate-shaped base material. Also good.

  When mixing a base material with the composition containing fullerenes, the solvent A, and the solvent B, it is preferable to make a base material exist uniformly in the said composition. In order to make it exist uniformly here, a base material may be mixed in the said composition at once, but, for example, a predetermined amount (small amount) of a base material is continuously or intermittently in the said composition. It is preferable to add to. As a specific method for continuously or intermittently adding such a predetermined amount of the base material, for example, the total amount of the base material used for the composition is continuously little by little. And a method of intermittently adding the base material to the composition using an appropriate addition method. This mixing method is a preferable method when the substrate is in the form of particles (powder).

  Similarly, when mixing the composition containing fullerenes, the solvent A, and the solvent B with the base material, it is preferable that the base material be present uniformly in the composition. In order to make it exist uniformly here, the said composition may be mixed with a base material at once, For example, predetermined amount (small amount) of the said composition is added to a base material continuously or intermittently. It is preferable to continue. As a specific method for continuously or intermittently adding such a predetermined amount of the composition, for example, the whole amount of the composition used for the substrate is continuously little by little. And a method of intermittently adding the composition to the substrate using an appropriate addition method. In this case, specific examples of the addition method for adding the composition include a method using a dropping funnel, an automatic dropping device, a metering pump, and the like. This mixing method is a preferable method when the substrate is in the form of particles (powder).

The time for addition is not particularly limited, and is usually 5 minutes or longer, preferably 10 minutes or longer, more preferably 30 minutes or longer, and further preferably 1 hour or longer in consideration of the uniformity of surface modification. On the other hand, from the viewpoint of industrial productivity, the upper limit is usually 20 hours or less, preferably 10 hours or less, more preferably 5 hours or less.
In the case where the substrate is mixed with the composition containing the fullerenes, the solvent A, and the solvent B, it is preferable to uniformly mix the composition during the addition of the substrate. Similarly, when the composition containing fullerenes, solvent A, and solvent B is mixed with the base material, it is preferable to uniformly mix the base material and the composition during the addition of the composition. In order to perform the mixing more smoothly, the base material may be dispersed in a predetermined solvent (for example, solvent B) before the base material and the composition are mixed.

  In addition, when the base material is mixed with the composition containing the fullerenes, the solvent A, and the solvent B, after adding the whole amount of the base material for the purpose of further compatibilizing the solvent B and the solvent A, etc. It is preferable to continue mixing for a predetermined time. Similarly, when a composition containing fullerenes, solvent A, and solvent B is mixed with the base material, the above composition is added in total for the purpose of further compatibilizing solvent A and solvent B, etc. Then, it is preferable to continue mixing for a predetermined time. Here, the mixing time is usually 10 minutes or longer, preferably 20 minutes or longer, and usually 10 hours or shorter, preferably 5 hours or shorter, more preferably 2 hours or shorter.

  Specific examples of the mixing method include a stirrer, blender, homogenizer, valve homogenizer, ultrasonic homogenizer, ultrasonic disperser, static mixer, stirring mixer, planetary mixer, ball mill, sand mill, roll mill, disc mill, and twin-screw kneader. Examples of the method include stirring, mixing, dispersion, and kneading. This makes it easier to obtain a uniformly treated fullerene surface-modified base material. In particular, when the solubility of fullerenes in the solvent A is low, or when the viscosity of the solvent A and the solvent B is high, the composition in the composition is likely to become non-uniform due to poor mixing, so an appropriate mixing method is applied. It is preferable.

When the base material is contained in the composition containing the fullerenes, the solvent A, and the solvent B (similarly, when the base material contains the composition containing the fullerenes, the solvent A, and the solvent B), Although not particularly limited, it is usually 0 ° C. or higher, preferably 20 ° C. or higher, and is usually 200 ° C. or lower, preferably 180 ° C. or lower, more preferably 100 ° C. or lower.
C-7. Separation method and drying method of fullerene surface modified base material <Separation method of fullerene surface modified base material>
By using the above method, a fullerene surface-modified base material in which fullerenes are present on the surface of the base material can be obtained. Here, it is preferable to separate the fullerene surface modification base material from the solvent A and the solvent B. When separating the fullerene surface-modified base material from the solvent A and the solvent B, the separation method is not particularly limited. A specific method may be the same as in manufacturing method 1 and manufacturing method 2.

<Drying method of fullerene surface modified base material>
When there are the solvent A and the solvent B remaining on the fullerene surface-modified base material obtained by the above operation, it is preferable to remove the solvent A and the solvent B, but this removal method is not particularly limited. . A specific method may be the same as in manufacturing method 1 and manufacturing method 2.
D. Fullerenes Surface-Modified Base Material Examples of fullerene surface-modified base materials manufactured by the manufacturing method of the present invention will be described.

  The particle size of fullerenes on the substrate is usually 0.7 nm or more. Usually, since the size of one fullerene molecule is about 0.7 nm (= 7 cm), when the fullerene is present on the substrate surface in a molecular state, the particle size of the fullerene is in the above range. On the other hand, the particle size of fullerenes on the substrate is usually 50 μm or less, preferably 1000 nm or less, more preferably 500 nm or less. The particle size of fullerenes is affected by the concentration of fullerenes in solvent A, the way of inclusion of solvent B, etc., but if it is within the above range, good surface modification of fullerenes with controlled surface conditions A substrate can be obtained.

  The abundance of fullerenes relative to the entire surface of the fullerene surface-modified substrate is usually 0.01% by weight or more, preferably 0.02% by weight or more, more preferably 0.06% by weight or more. By setting it as the above range, the effect of causing fullerenes to be present on the surface of the substrate is exhibited. For example, when the fullerene surface-modified base material of the present invention is used as a negative electrode material for a lithium secondary battery to be described later, the battery characteristics are improved by setting the above range. On the other hand, the abundance of fullerenes relative to the entire surface-modified substrate of fullerenes is usually 3.0% by weight or less, preferably 1.0% by weight or less, more preferably 0.2% by weight or less. When the abundance of fullerenes is excessively large, the performance of the fullerenes surface-modified base material may not be sufficiently exhibited.

In the present invention, it is preferable that the amount of fullerenes present on the substrate surface of the obtained fullerene surface-modified base material is as close as possible to the amount of fullerenes charged at the time of production. That is, it is preferable that as much as possible of the fullerenes used in the production be present on the surface of the substrate.
Specifically, the amount of fullerenes (hereinafter sometimes referred to as “eluting fullerenes”) eluted in the solvent A by containing the obtained fullerenes surface-modified base material in a predetermined amount of the solvent A. Ask. And the ratio of (the elution fullerene) to the amount of this elution fullerene and the amount of fullerenes used in the production of the fullerene surface modified base material (hereinafter sometimes referred to as “amount of fullerenes used for preparation”). )) / (Amount of fullerene used for preparation)) is preferably 0.5 or more, and more preferably 0.7 or more. On the other hand, the upper limit of (amount of eluted fullerenes) / (amount of fullerenes used for preparation) is preferably 1.

Here, the measurement method of (amount of eluted fullerenes) / (amount of fullerenes used for preparation) is not particularly limited, but the following method can be preferably used.
First, a predetermined amount of the fullerene surface-modified base material is mixed with a predetermined amount of solvent A. Although there is no restriction | limiting in particular as a mixing method here, What is industrially easy is performing ultrasonic dispersion | distribution. Thereafter, the mixed solution of the fullerene surface-modified base material and the solvent A is centrifuged as necessary. Then, the supernatant is extracted, and the concentration of the supernatant is measured using high performance liquid chromatography or the like. Then, the amount of fullerenes per unit weight of the base material (concentration of fullerenes in the fullerene surface modified base material) is converted from the obtained concentration, and the obtained conversion value and the fullerene surface modified base material production time From the “amount of fullerenes per unit weight of base material at the time of preparation” calculated from the above-mentioned preparation value, (amount of eluted fullerenes) / (amount of fullerenes used for preparation) may be calculated.

E. Applications The fullerene surface-modified base material of the present invention can be applied to various applications such as medical, electrical and electronic equipment, automobiles, building materials, and parts of industrial machines. This is because fullerenes have various functions derived from specific crystal structures, chemical properties, electronic states, and the like. Specific examples of such functions include ultraviolet absorption, radical trapping, photoconduction, photoinduced electron transfer, catalysis, adhesion improvement, and lubrication. The applicable application is not particularly limited as long as the above functions can be effectively extracted.

More specific applications include UV absorbing materials, radical deactivation materials, optical switches, solar cells, various secondary batteries, composite materials, solid lubricants, and the like.
Among these various uses, one of the uses that can utilize the function considered to be a radical trap possessed by fullerenes is a negative electrode material of a lithium secondary battery, particularly a lithium secondary battery. Similarly, another application that can use the function considered to be a radical trap possessed by fullerenes is an application that modifies the surface of the polymer material with fullerenes to increase the heat resistance of the polymer material. Such a polymer material can be applied to fields such as automobiles, building materials, and industrial machines.

Moreover, as a use which can utilize the effect of adhesiveness improvement which fullerene has, the use which needs to improve the adhesiveness of a metal base material and organic material (for example, polymer material) is mentioned. As an application example of such a use, for example, application to fields such as insulating materials, resists, displays, electric and electronic parts such as lithium secondary batteries, and building materials can be cited.
Hereinafter, some specific examples of applications in which the fullerene surface-modified base material of the present invention can be used will be described.

E-1. Lithium Secondary Battery A case where the fullerene surface modified base material of the present invention is used as a negative electrode active material of a lithium secondary battery will be described. When the fullerene surface-modified base material of the present invention is used as a negative electrode material (hereinafter sometimes referred to as negative electrode active material) of a lithium secondary battery, a carbonaceous material is usually used as the base material.

E-1-1. Advantages of using the fullerene surface-modified base material of the present invention as a negative electrode material Usually, an electrolyte (especially electrolysis) is used in an electrochemical reducing atmosphere at the interface between a negative electrode active material for a lithium secondary battery mainly composed of a carbonaceous material and an electrolyte. Reductive decomposition of the liquid solvent occurs. As a result of the decomposition, organic substances and lithium compounds which are decomposition products form a film called SEI (Solid Electrolyte Layer) on the surface of the carbonaceous material. The SEI substantially stops the reductive decomposition reaction of the electrolyte by blocking direct contact between the carbonaceous material and the electrolyte, and the battery is electrochemically stabilized.

  Most of the reactions that form this SEI proceed during the initial charging process when the negative electrode is first exposed to the electrochemically reduced state. However, since the electric power consumed in the reductive decomposition in the process of forming SEI is not stored as energy in the active material, it cannot be taken out by discharge. That is, of the electric power input in the initial charging, the portion consumed for SEI formation is lost, leading to a decrease in initial efficiency. Further, the reductive decomposition reaction between the surface of the carbonaceous material and the electrolyte proceeds gradually even after the initial charge, and this reaction also causes the storage stability and cycle characteristics of the lithium secondary battery to deteriorate.

  In the present invention, the initial efficiency of the lithium secondary battery is greatly increased by allowing fullerenes to be directly and uniformly present in a small particle size on the surface of the carbonaceous material (base material) where lithium is occluded and released from the electrolyte. It will be improved. The mechanism of this action is not clear, but due to the presence of fullerenes between the carbonaceous material surface and the electrolyte, direct contact between the carbonaceous material surface and the electrolyte is blocked, and SEI is formed from the beginning. The possibility of having the same effect, the presence of fullerenes may increase the efficiency of SEI formation from the reaction surface and the structure surface, and because the fullerenes exist uniformly with a small particle size There is a possibility that the SEI formed is thin and uniform.

Hereinafter, a negative electrode material for a lithium secondary battery, a negative electrode using the negative electrode material for the lithium secondary battery, and a lithium secondary battery using the negative electrode will be described.
E-1-2. Negative electrode material for lithium secondary battery When the fullerene surface modified substrate of the present invention is used as a negative electrode material for a lithium secondary battery, the fullerene surface modified substrate has a form in which fullerenes are present on the carbon material surface. Since the fullerenes, the method for producing a fullerene surface-modified base material, the properties of the fullerene surface-modified base material, and the like are as described in the above A to D, the description thereof is omitted here.

(1) Carbonaceous material As the material of the carbonaceous material, those described in the above base material may be used. A particularly preferable point when using a carbonaceous material as a negative electrode material of a lithium secondary battery will be described below.
The carbonaceous material usually has a powdery state at normal temperature (25 ° C.) and normal humidity (50% RH), and its average particle size is usually 1 μm or more, preferably 5 μm or more, and usually 45 μm. Hereinafter, it is preferably 35 μm or less, more preferably 25 μm or less. If the average particle size is excessively small, the specific surface area of the carbonaceous material increases, which may increase the irreversible capacity and decrease the battery capacity. On the other hand, if the average particle size is excessively large, the thickness of the active material layer is limited, and it may be difficult to form a uniform active material layer on the carbonaceous material.

The specific surface area of the carbonaceous material is usually 0.1 m ² / g or more, preferably 0.3 m ² / g or more, more preferably 0.5 m ² / g or more. When the specific surface area is excessively small, the rate characteristics of the battery are lowered. On the other hand, the specific surface area of the carbonaceous material is usually 30 m ² / g or less, preferably 20 m ² / g or less, more preferably 10 m ² / g or less. If the specific surface area is excessively large, the initial efficiency of the battery is lowered. The specific surface area is measured according to the BET method.

(2) Other materials included in negative electrode material for lithium secondary battery The negative electrode material for lithium secondary battery in the present invention is composed of a carbonaceous material (fullerene surface modified base material) whose surface is modified with the above fullerenes. May be. In addition to the fullerene surface-modified base material, for example, a binder (details will be described later) and other additives such as a conductive agent are further added to the negative electrode material for a lithium secondary battery. You may make it contain.

What is necessary is just to adjust suitably the kind and content of these materials according to the battery performance calculated | required.
(3) Relationship between carbonaceous material and fullerenes In the negative electrode material for a lithium secondary battery used in the present invention, the fullerenes are present on the surface of the carbonaceous material. The relationship between the carbonaceous substance and the fullerenes is as described in the above AD, but the following are particularly preferable points when the fullerene surface-modified base material of the present invention is used as a negative electrode material for a lithium secondary battery. explain.

The fullerenes may cover the entire surface of the carbonaceous material, but a portion covered with the fullerenes and a portion not covered may coexist on the surface of the carbonaceous material. The presence of the fullerenes and the nonexistent part on the surface of the carbonaceous material can increase the initial efficiency of the lithium secondary battery.
The particle size of fullerenes present on the surface of the carbonaceous material is usually 0.7 nm or more. Usually, since the size of one molecule of fullerenes is about 0.7 nm (= 7 cm), the particle size of fullerenes is in the above range when the fullerenes are present in a molecular state on the substrate surface. On the other hand, the particle size of fullerenes on the surface of the carbonaceous material is usually 50 μm or less, preferably 1000 nm or less, more preferably 500 nm or less. The particle size of fullerenes is affected by the concentration of fullerenes in solvent A, the manner in which solvent B is contained, etc. If within the above range, the surface of good fullerenes with a controlled surface body is controlled. A modified substrate can be obtained.

(4) Negative electrode, lithium secondary battery Hereinafter, a negative electrode for a lithium secondary battery containing the negative electrode material for a lithium secondary battery of the present invention and a lithium secondary battery using the negative electrode will be described.
In the present invention, the negative electrode material for a lithium secondary battery in which fullerenes are present on the surface of the carbonaceous material is used for producing a negative electrode for a lithium secondary battery.

Here, the lithium secondary battery usually has a configuration in which a battery element having a positive electrode and an electrolyte is housed in a case in addition to the negative electrode.
The negative electrode is usually formed by forming an active material layer formed of the negative electrode material on a current collector. That is, the active material layer contains at least a negative electrode active material (fullerenes surface-modified base material) in which fullerenes are present on the surface of the carbonaceous material. Usually, these materials further include a binder and, if necessary, a conductive agent. Has additives.

The ratio of the negative electrode active material in the active material layer is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, and usually 99% by weight or less, preferably 98% by weight or less. If the amount is too large, the mechanical strength of the electrode tends to be inferior.
The binder used for the active material layer needs to be stable with respect to the electrolytic solution and the like, and various materials are used from the viewpoint of weather resistance, chemical resistance, heat resistance, flame retardancy, and the like. Specifically, inorganic compounds such as silicate and glass, alkane polymers such as polyethylene, polypropylene and poly-1,1-dimethylethylene; unsaturated polymers such as polybutadiene and polyisoprene; polystyrene, polymethylstyrene, Examples thereof include polymers having a ring structure in a polymer chain such as polyvinyl pyridine and poly-N-vinyl pyrrolidone; celluloses such as methyl cellulose and sodium carboxymethyl cellulose.

  Other specific examples include acrylic derivative polymers such as polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, polymethyl acrylate, polyethyl acrylate, polyacrylic acid, polymethacrylic acid, and polyacrylamide; Fluorine resins such as vinyl chloride, polyvinylidene fluoride and polytetrafluoroethylene; CN group-containing polymers such as polyacrylonitrile and polyvinylidene cyanide; Polyvinyl alcohol polymers such as polyvinyl acetate and polyvinyl alcohol; Halogen-containing polymers such as vinylidene; conductive polymers such as polyaniline can be used.

  Also, mixtures of the above polymers, modified products, derivatives, random copolymers, alternating copolymers, graft copolymers, block copolymers (for example, styrene butadiene copolymers such as styrene butadiene rubber), etc. Can also be used. The weight average molecular weight of these resins is usually 10,000 to 3,000,000, preferably about 100,000 to 1,000,000. If it is too low, the strength of the coating film tends to decrease. On the other hand, if it is too high, the viscosity of the coating material for producing the negative electrode becomes high, and it may be difficult to form the electrode. Preferable binder resins include fluorine resins and CN group-containing polymers, and more preferably polyvinylidene fluoride.

The amount of the binder used is usually 0.1 parts by weight or more, preferably 1 part by weight or more, and usually 30 parts by weight or less, preferably 20 parts by weight or less, more preferably 10 parts by weight with respect to 100 parts by weight of the negative electrode active material. Less than parts by weight. If the amount of the binder is too small, the strength of the active material layer tends to decrease, and if the amount of the binder is too large, the battery capacity tends to decrease.
If necessary, the active material layer may contain additives, powders, fillers, and the like that exhibit various functions such as a conductive material and a reinforcing material.

  As the current collector used for the negative electrode, various materials that can function as a battery current collector can be used without causing problems such as electrochemical elution, and usually metals such as copper, nickel, stainless steel, etc. An alloy is used. Preferably, copper is used. The thickness of the current collector is usually 0.1 μm or more, preferably 1 μm or more, and is usually 100 μm or less, preferably 30 μm or less, more preferably 20 μm or less. If it is too thin, the mechanical strength tends to be weak, which causes a problem in production. If it is too thick, the capacity of the battery as a whole decreases. In order to reduce the weight of the secondary battery, that is, to improve the weight energy density, it is also possible to use a perforated carbonaceous material such as expanded metal or punching metal. In this case, the weight can be freely changed by changing the aperture ratio. In addition, when a contact layer is formed on both sides of such a perforated type carbonaceous material, the rivet effect of the coating film through this hole tends to make peeling of the coating film more difficult, but the aperture ratio is too high. When it becomes high, the contact area between the coating film and the carbonaceous material becomes small, so that the adhesive strength may be lowered. Moreover, in order to improve adhesiveness with an active material layer, the surface of a collector can be previously roughened. Current roughening methods include a method of rolling with a blasting process or a rough roll, a polishing cloth with a fixed abrasive particle, a grinding wheel, emery buff, a wire brush with a steel wire, etc. Examples thereof include a mechanical polishing method for polishing the surface, an electrolytic polishing method, and a chemical polishing method.

A negative electrode having an active material layer on a current collector is obtained by dispersing the negative electrode material for a lithium secondary battery using a solvent capable of dissolving a binder, and applying and drying the paint on the current collector. Can be manufactured.
Examples of the solvent used for forming the active material layer include N-methyl-2-pyrrolidone, dimethylformamide, and water, preferably N-methyl-2-pyrrolidone and water. The solvent concentration in the coating is at least 10% by weight, but is usually 20% by weight or more, preferably 30% by weight or more, and more preferably 35% by weight or more. Moreover, as an upper limit, it is 90 weight% or less normally, Preferably it is 80 weight% or less. If the solvent concentration is too low, coating may be difficult. If the solvent concentration is too high, it may be difficult to increase the coating thickness and the stability of the coating may be deteriorated.

For dispersion coating, a commonly used disperser can be used, and a planetary mixer, a ball mill, a sand mill, a biaxial kneader, or the like can be used.
There are no particular restrictions on the application device for applying the paint on the current collector, and slide coaters, extrusion type die coaters, reverse rolls, gravure coaters, knife coaters, kiss coaters, micro gravure coaters, rod coaters, blade coaters, etc. Among them, a die coater, a blade coater, and a knife coater are preferable, and an extrusion type die coater and a blade coater are most preferable from the viewpoint of simplicity in consideration of paint viscosity and coating film thickness.

After the coating material is applied on the current collector, the active material layer is formed by drying the coating film at a temperature of about 120 ° C. for about 10 minutes, for example.
The thickness of the active material layer is usually 10 μm or more, preferably 20 μm or more, and is usually 200 μm or less, preferably 150 μm or less. If the thickness of the active material layer is too thin, the battery capacity becomes too small. On the other hand, if the thickness is excessively high, the rate characteristics will deteriorate.

An electrolyte used for a lithium secondary battery usually has an electrolytic solution obtained by dissolving a lithium salt, which is a supporting electrolyte, in a non-aqueous solvent.
As the non-aqueous solvent, a solvent having a relatively high dielectric constant is preferably used. Specifically, cyclic carbonates such as ethylene carbonate and propylene carbonate, acyclic carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, glymes such as tetrahydrofuran, 2-methyltetrahydrofuran and dimethoxyethane, γ-butyllactone, etc. Lactones, sulfur compounds such as sulfolane, nitriles such as acetonitrile, and the like. The above non-aqueous solvent can use multiple types together.

The lithium salt is a supporting electrolyte used in the _{electrolyte, LiPF 6, LiAsF 6, LiSbF} 6, LiBF 4, LiClO 4, LiI, LiBr, LiCl, LiAlCl, L
Examples include iHF ₂ , LiSCN, LiSO ₃ CF _{2, and the} like. Of these, LiPF ₆ and LiClO ₄ are particularly preferred. The content of these supporting electrolytes in the electrolytic solution is usually 0.5 to 2.5 mol / l.

In addition, various additives can be added to the electrolyte as needed to improve battery performance.
The electrolyte is present inside the positive electrode and the negative electrode and between the positive electrode and the negative electrode. Between the positive electrode and the negative electrode, a support such as a porous film is used to prevent a short circuit between the positive electrode and the negative electrode. Is preferably present. As the porous film, a film made of a polymer resin or a thin film made of a powder and a binder can be preferably used, and more preferably a porous film made of polyethylene, polypropylene or the like.

The positive electrode of a lithium secondary battery usually has a form of lithium metal or a form in which a positive electrode active material layer containing a positive electrode active material is stacked on a current collector. Among the above forms, the positive electrode active material used in the form in which the positive electrode active material layer containing the positive electrode active material is stacked on the current collector includes a composite oxide of lithium and a transition metal, specifically Include lithium nickel composite oxides such as LiNiO ₂ and LiNiCoO ₂ , lithium cobalt composite oxides such as LiCoO ₂ , and lithium manganese composite oxides such as LiMn ₂ O ₄ . Some of the transition metal sites of these composite oxides may be substituted with other elements. By substituting a part of the transition metal with another element, the stability of the crystal structure can be improved. As other elements for substituting a part of the transition metal site at this time (hereinafter referred to as substitution elements), Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg , Ga, Zr, etc., preferably Al, Cr, Fe, Co, Li, Ni, Mg, Ga, and more preferably Al. The transition metal site may be substituted with two or more other elements. The substitution ratio by the substitution element is usually 2.5 mol% or more of the base transition metal element, preferably 5 mol% or more of the base transition metal element, and usually 30 mol% or less of the base transition metal element, Preferably it is 20 mol% or less of the transition metal element used as a base. If the substitution ratio is too small, the crystal structure may not be sufficiently stabilized. If the substitution ratio is too large, the capacity of the battery may be reduced. Of the lithium transition metal composite oxides, lithium cobalt composite oxide and lithium nickel composite oxide are more preferable, and LiCoO ₂ is particularly preferable. The particle size of the positive electrode active material is usually 1 μm or more, and usually 30 μm or less, preferably 10 μm or less in terms of excellent battery characteristics such as rate characteristics and cycle characteristics.

The positive electrode is usually formed by forming an active material layer having a positive electrode active material and a binder on a current collector. The type of binder used for the positive electrode and the method for forming the active material layer may be the same as those for the negative electrode.
Further, in the positive electrode, the current collector may be made of metal such as aluminum, copper, nickel, tin, and stainless steel, and alloys of these metals. In this case, aluminum is usually used as the positive electrode current collector. The shape of the current collector is not particularly limited, and examples thereof include a plate shape and a mesh shape. The thickness of the current collector is usually 1 μm or more, on the other hand, usually 50 μm or less, preferably 30 μm or less. If it is too thin, the mechanical strength will be weak, but if it is too thick, the battery will be large, the space occupied in the battery will be large, and the energy density of the battery will be small. What is necessary is just to make it the same as the said negative electrode collector except the material and film thickness of the said collector.

A battery element having a positive electrode, a negative electrode, and an electrolyte is housed in a case. Examples of the battery element include a form in which a laminate in which a positive electrode and a negative electrode are laminated via an electrolyte is wound, a form in which a positive electrode, a negative electrode, and an electrolyte are laminated in a flat plate shape, or a battery element laminated in the flat plate shape. A plurality of layers may be prepared and further stacked.
Examples of the case for storing the battery element include a coin cell, a metal can for a dry battery, and a case having shape variability.

Examples of electrical equipment that uses a lithium secondary battery as a power source include a portable personal computer, a pen input personal computer, a mobile personal computer, an electronic book player, a cellular phone, a cordless phone, a pager, a handy terminal, and a portable fax machine. , Portable copy, portable printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, minidisc, electric shaver, transceiver, electronic notebook, calculator, memory card, portable tape recorder, radio, backup power supply, motor, lighting Examples include appliances, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, shoulder massagers). The lithium secondary battery can also be used as a power source for electric vehicles.
E-2. Uses for improving the heat resistance of fullerene surface-modified base materials Uses for improving the heat resistance of fullerene surface-modified base materials include, for example, modifying the surface of a particulate polymer material with fullerenes. The use which raises the heat resistance of molecular material is mentioned. Such fullerene surface-modified base materials are used in fields where improvement in heat resistance is desired (for example, packaging materials, various molding materials such as household goods and daily necessities, miscellaneous goods, communication equipment parts, electrical parts, automobile parts, and laminates for printed circuits. It can be applied to laminates such as boards, building materials, furniture, interior decoration materials, adhesives, paints, decorative plates, industrial machines, etc.).

As the polymer material, the materials described above can be used.
From the viewpoint of demanding high heat resistance, polyethylene, polypropylene, polymethylpentene, polybutene, polybutadiene, polystyrene, styrene butadiene resin, polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, ethylene vinyl acetate are preferable as the polymer material. Copolymer, polymethyl methacrylate, polymethyl acrylate, polytetrafluoroethylene, ethylene polytetrafluoroethylene copolymer, polyacetal, polyamide, polycarbonate, polyphenylene ether, polysulfone, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyethersulfone , Polyimide, polyamideimide, polyphenylene sulfide, polyoxybenzoyl, polyetherketone, polyether Imide, cellulose acetate, cellulose butyrate, carboxymethylcellulose, cellophane, celluloid, phenol resin, novolac resin, urea resin, melamine resin, benzoguanamine resin, unsaturated polyester resin, diallyl phthalate resin, alkyd resin, epoxy resin, urethane resin, silicone resin Is to use.

  More preferably industrially, the polymer material is polyethylene, polypropylene, polymethylpentene, polybutene, polybutadiene, polystyrene, styrene butadiene resin, polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, ethylene vinyl acetate copolymer, polymethyl. Methacrylate, polymethyl acrylate, polytetrafluoroethylene, ethylene polytetrafluoroethylene copolymer, polyacetal, polyamide, polycarbonate, polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyethersulfone, polyimide, polyamideimide, polyphenylene sulfide , Polyoxybenzoyl, polyetherketone, polyetherimide, cellulose acetate, butyric acid cell Over scan is to use carboxymethyl cellulose, cellophane, celluloid, phenol resin, urea resin, melamine resin, benzoguanamine resin, alkyd resin, epoxy resin, urethane resin, silicone resin.

The property of the polymer material is not particularly limited, such as a plate shape, a particle shape, or a lump shape. However, the polymer material is preferably in the form of a particulate material because it has a large specific surface area and can exert a large effect of improving heat resistance. Is to use. The particle diameter and the like of the polymer material in the case where the particulate polymer material is used are as described in A above. In addition, the method for modifying the fullerenes to the polymer material is as described in the above A to D.
E-3. Uses for improving adhesiveness possessed by fullerenes Applications for utilizing the effect of improving adhesiveness possessed by fullerenes include adhesion between a metal substrate and an organic film containing an organic material (for example, a polymer material). Applications that need to be improved are listed. In general, the adhesion between a metal and an organic film tends to be weak. In such a case, fullerenes may be present between the metal substrate and the organic film in order to improve the adhesion between the metal substrate and the organic film. There are a variety of uses that require such improved adhesiveness. For example, it can be applied to fields such as insulating materials, resists, displays, electric and electronic parts such as lithium secondary batteries, building materials, painting, and adhesives. It is done.

  Examples of the metal used as the base material include pure metals and alloys. Specifically, Fe (iron), Cu (copper), Ni (nickel), Co (cobalt), W (tungsten), Ag (silver), Au (gold), Pt (platinum), Ti (titanium), Al (aluminum), Li (lithium), Mo (molybdenum), Cr (chromium), In (indium), Ta (tantalum), Nb (niobium), Y (yttrium), Sn (tin), Zn (zinc), A simple substance such as Pb (lead) or an alloy can be used.

It is preferable that the effect of the surface treatment of the present invention is remarkably exhibited. Fe (iron), Cu (copper), Ni (nickel), Co (cobalt), W (tungsten), Ag (silver), Au (Gold), Pt (platinum), Ti (titanium), Al (aluminum), In (indium), Sn (tin), Zn (zinc), Pb (lead), and other metals.
Other properties required for the substrate are as described in A above. However, since the adhesive area between the plate-like substrate and the organic film tends to be small compared to the particulate substrate, the adhesion between the organic film and the description of the plate-like metal becomes insufficient. Cheap. For this reason, if fullerenes are present on the surface of the metal substrate in such a case, the adhesion between the organic film and the substrate can be easily improved.

  Modification of fullerenes to a metal substrate is as described in the above A to D.

Examples The present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
(Example 1)
[Surface treatment of carbonaceous materials]
As fullerenes, fullerene oxide produced by oxidizing C ₆₀ (the number of oxygen bonded to fullerene was 1 to 9) was used. A carbonaceous material was used as the substrate. As the carbonaceous material, artificial graphite having a particle size of 20 μm and a specific surface area of 4.7 m ² / g was used.

[Step 1 of production method 1]
As solvent A, 1,2,4-trimethylbenzene (TMB) was used.
The above fullerene oxide was dissolved in TMB at a solid content of 0.05% by weight, and 100 g of this solution was put into a glass container having an internal volume of 1 liter. The concentration of oxidized fullerene in TMB is 0.44 mg / ml.

Further, 50 g of the above artificial graphite was put into this container and stirred for 30 minutes while being kept at 25 ° C. in a water bath.
[Step 2 of production method 1]
Methanol was used as the solvent B.
While stirring the dispersion obtained in Step 1 above with a magnetic stirrer, 500 g of methanol was added dropwise over about 40 minutes, and then stirring was continued for about 1 hour. Next, the above dispersion liquid in which methanol was dropped was added to the quantitative filter paper No. The mixture was filtered with 5C (retained particle diameter: 1 μm), and the solid substance on the filter paper (artificial graphite with oxidized fullerene on the surface) was washed with 250 g of methanol. The obtained solid substance is dried at 70 ° C./about 0.1 MPa, and the modification ratio is 0.1% by weight, and artificial graphite having oxidized surface fullerene on the surface (this may simply be referred to as modified powder). )

[Particle size of oxidized fullerene]
The particle size of the oxide fullerenes present on the surface of the carbonaceous material was measured as follows.
Steps 1 and 2 were carried out in the same manner as in Production Method 1 except that artificial graphite was not added in Production Method 1. And the dispersion liquid which fullerenes precipitated by dripping methanol was measured using the batch cell of the particle size distribution analyzer SALD-2100 made from Shimadzu Corporation. And the obtained median diameter was made into the particle size of fullerenes. The median diameter was 0.1 μm.

[Observation with electron microscope]
In observation of a scanning electron microscope (hereinafter simply referred to as SEM), the presence of fullerene oxide on the surface of the modified powder was confirmed. The fullerene oxide was scattered on the graphite surface.
[Preparation of negative electrode]
As a negative electrode active material, 98 parts by weight of the modified powder, 1 part by weight of sodium carboxymethyl cellulose, 1 part by weight of styrene butadiene rubber, and 100 parts by weight of water were kneaded to obtain a negative electrode paint.

Immediately after the preparation of the negative electrode paint, this paint was applied onto a copper foil (thickness 20 μm) with a doctor blade (blade coater), dried, and roll-pressed at a linear pressure of 100 kN / m to obtain a negative electrode.
[Production of battery]
The negative electrode was punched into 13 mm and the battery characteristics were evaluated using a coin cell.

When producing a coin cell, Li metal foil (thickness 0.5 mm, φ14 mm), an electrolytic solution, and a separator were used as a counter electrode. In addition, the electrolyte solution and separator which were used are as follows.
The electrolyte used LiPF ₆ as a lithium salt using ethylene carbonate and diethyl carbonate (both manufactured by Mitsubishi Chemical Corporation) in a ratio (volume%) of 1: 1 as a non-aqueous solvent. The concentration of the lithium salt was 1 mol / l.

As the separator, a polyethylene sheet (manufactured by Tonen Chemical Co., Ltd.) having a film thickness of 16 μm was used.
(Example 2)
[Surface treatment of carbonaceous material, production method 1]
Except for using natural graphite having a particle size of 18 μm and a specific surface area of 4.5 m ² / g as the carbonaceous material, the modification rate is 0.1% by weight and fullerene oxide is formed on the surface in the same manner as in Production Method 1 of Example 1. The natural graphite present was obtained.

[Preparation of negative electrode]
A negative electrode was produced in the same manner as in Example 1.
[Production of battery]
A negative electrode was produced in the same manner as in Example 1.
(Comparative Example 1 and Reference Experiment 1)
The following three solutions were measured by high performance liquid chromatography.
A solution (solution 1) obtained by dissolving fullerene oxide in 1,2,4-trimethylbenzene obtained in [Step 1 of production method 1] in Example 1
A supernatant liquid (solution 2) decanted from a composition obtained by mixing artificial fullerene with a solution of fullerene oxide dissolved in 1,2,4-trimethylbenzene obtained in [Production Method 1 Step 1] of Example 1. )
-Filtrate (solution 3) obtained by performing filtration after dropping methanol in [Step 2 of production method 1] in Example 1
Here, the measurement conditions of high performance liquid chromatography were as follows.

(Measurement condition)
Measuring instrument: Tosoh LC-8020
Eluent: Toluene / methanol = 40/60 (v / v)
Flow rate: 1.0 mL / min
Column: YMC-Pack ODS-AM-307-3
Column temperature: 45 ° C
Detection wavelength: 308nm
The results are shown in Table-1.

  From Table 1, since there is no significant difference in the total peak area between Solution 1 and Solution 2, the solution of fullerene oxide in 1,2,4-trimethylbenzene and artificial graphite are mixed to produce fullerene oxide. It can be seen that adsorption hardly occurs. That is, in this state, even if 1,2,3-trimethylbenzene (1,2,3-trimethylbenzene solution in which oxidized fullerene is dissolved) is removed by decantation, a sufficient amount of oxidation is produced on the artificial graphite. There will be no fullerene.

On the other hand, by using this method of modifying the base material (carbonaceous material surface) while adding solvent B to precipitate fullerenes, almost the entire amount of oxidized fullerene is adsorbed on the surface of artificial graphite. It turns out that it is effective as a surface modification method.
(Comparative Example 2)
A battery was manufactured and evaluated in the same manner as in Example 1 except that the surface treatment of the carbonaceous material was performed by the following method.

[Surface treatment of carbonaceous materials]
The fullerene oxide obtained in Example 1 was dissolved in 1,2,4-trimethylbenzene at a solid content of 0.01% by weight, and 100 g of this solution was put into a glass container having an internal volume of 300 ml.
Further, 9.99 g of the above artificial graphite was put into this container, stirred for about 12 hours, and then heated and dried at 60 ° C. to obtain artificial graphite having a modification ratio of 0.1% by weight and having fullerene oxide on the surface.

(Comparative Example 3)
In Example 1, an electrode was prepared and the battery characteristics were evaluated in the same manner as in Example 1 except that the fullerene oxide was not present on the surface of the carbonaceous material.
(Comparative Example 4)
In Example 2, an electrode was prepared and the battery characteristics were evaluated in the same manner as in Example 2 except that the surface treatment of the carbonaceous material was performed by the method described in Comparative Example 2.

(Comparative Example 5)
In Example 2, an electrode was produced in the same manner as in Example 2 except that the fullerene oxide was not present on the surface of the carbonaceous material, and the battery characteristics were evaluated.
[Test example]
The battery characteristics of the batteries obtained in Examples 1 and 2 and Comparative Examples 2 to 5 were evaluated.

The battery characteristics were evaluated by charging and discharging the coin cell and measuring the first charge capacity, the first discharge capacity, and the initial efficiency. Charging conditions were constant voltage charging and constant current charged at 0.3 mA / cm ² until 3mV to 0.03 mA / cm ^2. The discharge conditions were 0.3 mA / cm ² and constant current discharge to 1.5V. The initial efficiency was calculated from (first discharge capacity) / (first charge capacity).

  Table 2 shows the first charge capacity, the first discharge capacity, and the initial efficiency measured as described above.

  From Table 2, it can be seen that in both natural graphite and artificial graphite, the initial efficiency is increased by about 1% by surface modification with fullerene oxide by the production method of the present invention. Further, from the results of Example 1 and Comparative Example 2 and from the results of Example 2 and Comparative Example 4, the surface of artificial graphite and natural graphite is modified by the production method of the present invention, thereby modifying the solvent by drying. It can be seen that the initial efficiency is improved as compared with FIG.

From the above results, it can be seen that more precise control of the modification of the carbonaceous material surface with the fullerene derivative is effective for improving battery performance.
(Example 3)
[Surface treatment of substrate]
As fullerenes, manufactured by Frontier Carbon Corporation: using the (trade name Nano-time _{mix, C 70 / C 60 = 25} /60) fullerene. Hereinafter, in this embodiment, it is referred to as “nanomumix”. As the substrate, copper foil and aluminum foil having a thickness of 20 μm were used.

Copper foil and aluminum foil (hereinafter sometimes referred to collectively as metal foil) were cut into a size of 3 cm × 3 cm in advance.
[Step 1 of production method 1]
As solvent A, 1,2,4-trimethylbenzene (TMB) was used.
The above nanomux was dissolved in TMB at a solid content of 0.05% by weight, and 10 g of this solution was put into a glass container having an internal volume of 100 ml. The concentration of fullerene in TMB is 0.44 mg / ml.

The copper foil was further put into this container and stirred for 30 minutes while being kept at 25 ° C. in a water bath.
[Step 2 of production method 1]
Methanol was used as the solvent B.
While stirring the liquid obtained in Step 1 above with a magnetic stirrer, 50 g of methanol was added dropwise over about 40 minutes, and then the stirring was continued for about 1 hour. Thereafter, the metal foil was taken out and dried at 100 ° C./about 0.1 MPa to obtain a copper foil having nanomux on the surface.

In addition, the said process 1 and the process 2 were performed also about the aluminum foil, and the aluminum foil which has a nano mix on the surface was obtained.
[Adjustment of paint for organic film formation]
A paint was prepared according to the composition shown below. The following materials were used at the following blending ratio. That is, natural graphite and polyfucavinylidene were mixed in N-methyl-2-pyrrolidone and stirred for 30 minutes to form a paint.

Natural graphite (particle size 18 μm): 90.0 parts Polyvinylidene fluoride (manufactured by Kureha Chemical Industry Co., Ltd.): 10.0 parts N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Corporation): 150.0 parts
[Application of organic film on metal foil]
A copper foil having a nanomix on the surface obtained by the above production method 1 and an aluminum foil having a nanomix on the surface are placed on a PET film, and the paint is applied using a doctor blade, followed by drying at 100 ° C. for 10 minutes. did.

In this way, an organic film was formed on the substrate.
(Comparative Example 6)
A 20 μm-thick copper foil and aluminum foil cut to a size of 3 cm × 3 cm were used as they were, and the surface treatment of the copper foil and the aluminum foil was not performed. A film was formed.

[Test example]
A cross-cut cellophane tape peel test was performed on the samples obtained in Example 3 and Comparative Example 6 (samples in which an organic film was formed on a substrate).
That is, the organic film was cut at an interval of 1 mm with respect to a 10 mm × 10 mm region in the sample (100 squares of 1 mm × 1 mm were produced). When cutting into the organic film, care was taken not to cut the metal foil of the base material.

  Then, after the cellophane tape (Cellotape (registered trademark), manufactured by Nichiban Co., Ltd.) was pressure-bonded, the organic film remaining on the substrate side was observed. Table 3 shows the results.

From the above results, it can be seen that in any metal foil, the adhesion is improved by surface modification with Nanomux using the production method of the present invention.
Example 4
[Surface treatment of polymer materials]
As fullerenes, manufactured by Frontier Carbon Corporation: using the (trade name Nano-time _{mix, C 70 / C 60 = 25} /60) fullerene. Hereinafter, in this embodiment, it is referred to as “nanomumix”. As the polymer material, sodium carboxymethyl cellulose (trade name: Serogen WS-C, average molecular weight: 128.000 to 135,000) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. was used. In the following examples, it is expressed as CMC.

[Step 1 of production method 1]
As solvent A, 1,2,4-trimethylbenzene (TMB) was used.
The above nanomux was dissolved in TMB at a solid content of 0.05% by weight, and 100 g of this solution was put into a glass container having an internal volume of 1 liter. The concentration of fullerene in TMB is 0.
44 mg / ml.

The container was further charged with 4.95 g of CMC and stirred for 30 minutes while being kept at 25 ° C. in a water bath.
[Step 2 of production method 1]
Methanol was used as the solvent B.
While stirring the dispersion obtained in Step 1 above with a magnetic stirrer, 500 g of methanol was added dropwise over about 40 minutes, and then stirring was continued for about 1 hour.

Next, the dispersion liquid in which methanol was dropped was added to the quantitative filter paper No. Filtration was performed using 5C (retained particle diameter: 1 μm). Then, a solid substance (CMC having fullerenes attached to the surface) on the filter paper was washed with 250 g of methanol.
The obtained solid substance (CMC with fullerenes attached to the surface) was dried at 100 ° C./about 0.1 MPa to obtain CMC having a modification ratio of 1% by weight and having nanomix on the surface. .

(Comparative Example 7)
0.05 g of the above Nanomu mix and 4.95 g of CMC were pulverized and mixed in a mortar for 5 minutes to obtain a mixture of Nanomu mix and CMC.
[Test example]
About 10 mg of the sample obtained in Example 4 and Comparative Example 7 was weighed and subjected to a heat resistance test by thermogravimetric / differential thermal analysis (TG-DTA). And 5 wt% weight loss temperature was read from the obtained weight loss curve, and it was set as the heat resistance parameter | index.

<TG-DTA measurement conditions>
Apparatus: DTG-50 manufactured by Shimadzu Corporation
Sample amount: about 10mg
Temperature range: Room temperature to 300 ° C
Temperature increase rate: Room temperature to 30 ° C 1 ° C / min
Hold at 30 ° C for 5 minutes
30 ° C. to 300 ° C. 10 ° C./min Gas flow rate: Air 70 mL / min The 5 wt% weight loss temperature of each polymer material is as follows.

  From the above results, it can be seen that the heat resistance is improved by modifying the surface of the polymer material with nano-mix using the production method of the present invention.

Claims (14)

After containing the base material and fullerene in the solvent A,
A solvent B having a lower solubility of the fullerenes than the solvent A is further included;
A method for producing a fullerene surface-modified base material, comprising producing a fullerene surface-modified base material in which the fullerene is present on the surface of the base material.   The base material is contained in the solvent A after the fullerenes are contained in the solvent A when the base material and the fullerenes are contained in the solvent A. Of producing a fullerene surface-modified base material. After preparing a composition α containing fullerenes and a solvent A, and a composition β containing a solvent B and a base material having lower solubility of the fullerenes than the solvent A,
Contacting the composition β and the composition α,
A method for producing a fullerene surface-modified base material, comprising producing a fullerene surface-modified base material in which the fullerene is present on the surface of the base material. After the fullerenes are contained in the solvent A, the solvent A having a lower solubility of the fullerenes than the solvent A is further contained,
Then, a fullerenes surface-modified base material in which the fullerenes are present on the surface of the base material is manufactured by adding the base material. The solvent A and the solvent B are
The production of a fullerene surface-modified base material according to any one of claims 1 to 4, satisfying a relationship of (solubility of fullerenes in solvent B) / (solubility of fullerenes in solvent A) ≤ 0.5. Method.   6. The solvent A is at least one selected from the group consisting of a benzene solvent, a naphthalene solvent, a heterocyclic solvent, an alkane solvent, a haloalkane solvent, a polar solvent, and carbon disulfide. The manufacturing method of the fullerene surface modification base material of any one of these.   The solvent B is at least one selected from the group consisting of alcohol solvents, ketone solvents, ether solvents, ester solvents, acetonitrile, dimethyl sulfoxide, dimethylformamide, nitromethane, nitroethane, and water. 6. The method for producing a fullerene surface-modified base material according to any one of 6 above. Fullerenes are C ₆₀ , C ₇₀ , C ₇₄ , C ₇₆ , C ₇₈ , C ₈₀ , C ₈₂ , C ₈₄ , C ₈₆ , C ₈₈ , C ₉₀ , C ₉₂ , C ₉₄ , C ₉₆ , C ₉₈ , C ₁₀₀ , C ₆₀ derivative, C ₇₀ derivative, C ₇₄ derivative, C ₇₆ derivative, C ₇₈ derivative, C ₈₀ derivative, C ₈₂ derivative, C ₈₄ derivative, C ₈₆ derivative, C ₈₈ derivative The derivative according to claim 1, wherein the derivative is at least one selected from the group consisting of a derivative, a C ₉₀ derivative, a C ₉₂ derivative, a C ₉₄ derivative, a C ₉₆ derivative, a C ₉₈ derivative, and a C ₁₀₀ derivative. The manufacturing method of the fullerene surface modification base material of any one of Claims 1.   9. The substrate according to claim 1, wherein the substrate is at least one selected from the group consisting of metals, metal compounds, semiconductors, glasses, ceramics, carbonaceous substances, and polymer materials. A method for producing a fullerene surface-modified base material according to claim 1.   The said base material is a particulate form, The manufacturing method of the fullerene surface modification base material of any one of Claims 1 thru | or 9.   A fullerene surface-modified base material produced by the method for producing a fullerene surface-modified base material according to any one of claims 1 to 10.   The fullerene surface-modified base material according to claim 11, wherein the base material is a carbonaceous material, and the fullerene surface-modified base material is a negative electrode material for a lithium secondary battery.   A negative electrode for a lithium secondary battery, comprising the fullerene surface-modified base material according to claim 12.   A lithium secondary battery using the negative electrode according to claim 13.