JP2002362909A - Method for producing low valence metallic oxide particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily and stably producing new low valence metallic oxide particles by which low valence-metal-containing metallic oxide particles having excellent monodispersibility or the like, and also satisfactorily controlled in particle size, size distribution, composition or the like can easily and stably be obtained at a low cost. SOLUTION: In the method for producing first low valence metallic oxide particles, a mixture containing metallic carboxylate and alcohol is heated, and they are reacted; wherein, the above mixture further contains a pyrrolidone compound. Further, in the method for producing second low valence metallic oxide particles, a mixture containing a metallic alkoxy group-containing compound and a carboxyl group-containing compound is heated, and they are reacted; wherein, the above mixture further contains a pyrrolidone compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing low valent metal oxide particles. More specifically, a novel metal salt of a metal carboxylate or a metal alkoxy group-containing compound that is a raw material is reduced, and a low-valent metal oxide-based particle excellent in monodispersity and the like can be highly selectively and easily obtained. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Metal oxide particles are used in vulcanization accelerators for rubber, various paints, printing inks, paints, glass, catalysts, pharmaceuticals, pigments, ferrites, and other raw materials.
Particles having a particle diameter of 0.1 μm or less and having high dispersibility are required.

Conventionally, methods for obtaining metal oxide-based particles include a method in which a hydroxide or a carbonate obtained by neutralizing and hydrolyzing a metal salt in an aqueous solution is dried and calcined, or a method in which a metal alkoxide is used. A so-called wet method typified by a method of hydrolysis in alcohol, and a so-called dry method typified by a method of treating metal vapor at a high temperature in an oxygen atmosphere or a method utilizing thermal decomposition of a metal salt are known. ing.
However, it is difficult to obtain fine particles having a small particle diameter, particularly ultra-fine particles at the nanometer level, by the above-mentioned conventional wet method. It was difficult to obtain a solid and a solid solution oxide. Therefore, in order to solve such a problem, for example, a method of heating metal acetate in the presence of alcohol (heating a mixture containing metal acetate and alcohol) (Japanese Patent Application Laid-Open No. 2000-185916)
For example, a method for producing metal oxide-based particles has been disclosed.

In recent years, semiconductor functions,
Metals containing low-valent metal atoms that are better than metal oxide-based particles containing metal atoms of stable valence currently manufactured industrially in terms of electronic physical properties such as electron conduction function and magnetic function Oxide-based particles, so-called low-valent metal oxide-based particles, have attracted attention. These low-valent metal oxide-based particles are expected to work synergistically with physical properties due to low valence and quantum effects in the region where the particle diameter is fine, and also exhibit new optoelectronic properties. Have been. Further, as is clear from, for example, Cu ₂ O, the low-valent metal oxide has a low oxygen content, and thus is useful as a raw material for forming a metal thin film having good film quality and its auxiliary raw material.

Heretofore, the following methods have been generally known as methods for producing the low-valent metal oxide-based particles. A method in which a metal compound containing a low-valent metal atom is used as a starting material and applied to the above-described conventional method for producing metal oxide-based particles. A method of reducing metal oxide-based particles containing stable valence metal atoms or metal hydroxide-based particles that are precursors thereof.

However, the method (1) has a problem that the low-valent metal compound as a raw material generally has poor oxidation resistance, is hardly industrially available, and is expensive. However, there is a problem that not only is the process expensive due to the need for an environment capable of high-temperature treatment, but also secondary aggregation of particles easily proceeds during the reduction treatment, so that it is difficult to obtain fine particles.

[0007]

Accordingly, an object of the present invention is to provide a metal oxide-based particle containing a low-valent metal, which is excellent in monodispersibility and the like, has a particle diameter, a particle size distribution and a composition. It is an object of the present invention to provide a novel method for producing low-valent metal oxide-based particles, which can be easily, stably and inexpensively obtained in a well-controlled state.

[0008]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned problems. As a result, if a pyrrolidone compound is further allowed to coexist in the reaction system of the conventional method for producing metal oxide-based particles, not only the conversion reaction from the metal compound to the metal oxide-based particles but also the contained metal atom It has been found that a highly selective and easy reduction reaction can also occur. In addition, the present inventor has devised a method of heating a mixture containing a metal alkoxide and a carboxyl group-containing compound, in addition to the above-described conventional method for producing metal oxide-based particles, in which the same effect can be expected,
Thus, it has been found that the conversion reaction and the reduction reaction described above occur when the pyrrolidone compound is allowed to coexist in this reaction system.

The metal oxide-based particles obtained by such a reaction are so-called low-valent metal oxide-based particles in which the contained metal atoms are reduced to have a low valence.
The inventors have confirmed that they are also excellent in monodispersity and the like, and have completed the present invention.

That is, the first method for producing low-valent metal oxide particles according to the present invention is a method for producing metal oxide particles in which a mixture containing a metal carboxylate and an alcohol is heated and reacted. Wherein the mixture further comprises a pyrrolidone compound.

The second method for producing low-valent metal oxide-based particles according to the present invention is a method for producing metal oxide-based particles in which a mixture containing a metal alkoxy group-containing compound and a carboxyl group-containing compound is heated and reacted. The method, wherein the mixture further comprises a pyrrolidone compound.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The first production method according to the present invention is a method in which a mixture containing a metal carboxylate and an alcohol is heated to cause a reaction. Compound (metal alkoxide)
This is a method in which a mixture containing a compound and a carboxyl group-containing compound is reacted by heating. In any of the above methods, the mixture is characterized in that the mixture further contains a pyrrolidone compound.

First, each component contained in the mixture used in the first and second production methods will be described below.

The metal carboxylate used in the first production method is not particularly limited, and examples thereof include a metal salt of a carboxyl group-containing compound described below. Among these, metal saturated carboxylate is preferred, and metal acetate is most preferred. There is no particular limitation on the metal (M) contained in the metal carboxylate.
4A, 5A, 6A, 7A, 8, lanthanoid, 1B, 2
B, 3B, 4B, 5B, and 6B are preferably polyvalent metal atoms contained in each group, and among these, Ti,
V, Nb, Cr, Mn, Fe, Co, Ni, Cu, Z
n, Ga, Ge, As, Se, Zr, Nb, Mo, T
c, Ru, Rh, Pd, Ag, In, Sn, Sb, T
e, Ce, Pr, Nd, Sm, Eu, Tb, Gd, D
y, Tm, Yb, Hf, Ta, W, Re, Os, Ir,
Preference is given to those in which low-valent metal atoms such as Pt, Au, Tl, Pb, Bi and Po are useful, and Group 8 metals; Ti,
V, Mn, Sn, Sb; Ce, Pr, Nd, Sm, E
Lanthanoids such as u, Tb, Gd, Dy, Tm, Yb, and Hf; Mo, W, Cu, and the like are more preferable, and are suitable for producing low-valent metal oxide-based particles.

The alcohol used in the first production method is not particularly limited. Examples thereof include aliphatic monohydric alcohols (methanol, ethanol, isopropyl alcohol, n-butanol, t-butyl alcohol, stearyl alcohol, etc.), Aliphatic unsaturated monohydric alcohol (allyl alcohol, crotyl alcohol, propargyl alcohol, etc.), alicyclic monohydric alcohol (cyclopentanol, cyclohexanol, etc.), aromatic monohydric alcohol (benzyl alcohol, cinnamyl alcohol, Methylphenolcarbinol, etc.), phenols (ethylphenol, octylphenol, catechol, xylenol, guaiacol, p-cumylphenol, cresol, m-cresol, o-cresol, p-cresol, dodecylphenol Monohydric alcohols such as naphthol, nonylphenol, phenol, benzylphenol, p-methoxyethylphenol, and heterocyclic monohydric alcohols (furfuryl alcohol and the like); alkylene glycols (ethylene glycol, propylene glycol, trimethylene glycol, 1 , 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, pinacol, diethylene glycol, triethylene glycol, etc.), aliphatic having an aromatic ring Glycols (hydrobenzoin, benzpinacol, phthalyl alcohol, etc.), alicyclic glycols (cyclopentane-
Glycols such as 1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, and polyoxyalkylene glycol (polyethylene glycol, polypropylene glycol, etc.); propylene glycol monomethyl ether, propylene glycol monoethyl Ethers, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, 3-methyl-3-methoxybutanol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, triethylene glycol monomethyl ether, ethylene glycol monoacetate, etc. Derivatives such as monoethers and monoesters; hydroquinone, resorcinol, 2,2-bis (4-hydroxyphene); Aromatic diols and their monoethers and monoesters Le) propane; trihydric alcohols and their monoethers such as glycerol, can be mentioned monoesters, diethers and diesters.

The amount of the alcohol used in the first production method is not particularly limited, but is preferably 1 to 50 times the weight of the metal carboxylate in terms of metal oxide, preferably 2 to 50 times. More preferably, the amount is up to 20 times.

The metal alkoxy group-containing compound used in the second production method is not particularly limited. For example, a compound represented by the following general formula (1) or a compound obtained by subjecting the compound to (partial) hydrolysis / condensation Can be mentioned.

M (OR^a)_nmR^b _m (1) (where M is a metal atom; R^aIs a hydrogen atom, is substituted
Alkyl group, cycloalkyl group, acyl
Group, aralkyl group, aryl group
1 type; R^bIs a hydrogen atom, an optionally substituted alkyl
Group, cycloalkyl group, acyl group, aralkyl group,
A reel group, an unsaturated aliphatic residue, and OR ^aNon-base
At least one selected from organic groups containing a functional group;
Valence of metal atom M; m is an integer in the range of 0 to n-1
You. ) In the general formula (1), R^aIncludes a hydrogen atom and / or
Is an optionally substituted group such as an alkoxyalkyl group.
Alkyl groups are preferred. Also, R^bAs being replaced
An alkyl group, a cycloalkyl group, an acyl group,
Aralkyl groups, aryl groups, unsaturated aliphatic residues, and
And OR of β-diketone compounds, etc.^aFunctional groups other than
At least one selected from organic groups
New

In the general formula (1), M can be a metal contained in the above-mentioned metal carboxylate, and the same is preferable for M.

In the general formula (1), examples of the compound containing a metal alkoxy group in which m = 1 or 3 include various organosilicon compounds (m = 1, 2 or 3), titanate coupling agents (m = 1, 2 or 3), an aluminate coupling agent (m = 1 or 2) and the like.

Examples of the organosilicon compound include vinyltrimethoxysilane, vinyltriethoxysilane,
Vinyl silane coupling agents such as vinyl tris (β-methoxyethoxy) silane and vinyl triacetoxy silane; N- (2-aminoethyl) -3-aminopropylmethyldimethoxy silane, 3-N-phenyl-γ-aminopropyl tri Methoxysilane, N, N'-bis [3-
(Trimethoxysilyl) propyl] amino-based silane coupling agents such as ethylenediamine; epoxy-based silane coupling agents such as γ-glycidoxypropyltrimethoxysilane and β- (3,4-ethoxycyclohexyl) ethyltrimethoxysilane; Chlorosilane coupling agents such as 3-chloropropyltrimethoxysilane; methacryloxysilane coupling agents such as 3-methacryloxypropyltrimethoxysilane; mercaptosilane coupling agents such as 3-mercaptopropyltrimethoxysilane; N -(1,3-dimethylbutylidene) -3-
Ketimine silane coupling agents such as (triethoxysilyl) -1-propanamine; cationic silane coupling agents such as N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane hydrochloride Alkyl silane coupling agents such as methyltrimethoxysilane, trimethylmethoxysilane, decyltriethoxysilane, and hydroxyethyltrimethoxysilane; and γ-ureidopropyltriethoxysilane.

Examples of titanate-based coupling agents include isopropyl triisostearoyl titanate, isopropyl trioctaloyl titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, and tetraisopropyl tris ( Dioctyl pyrophosphate) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, tetra (2, 2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, isopro Distearate isostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, and it can include isopropyl tricumylphenyl titanate.

As the aluminate coupling agent,
For example, diisopropoxyaluminum ethyl acetoacetate, diisopropoxyaluminum alkyl acetoacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkyl acetoacetate mono (dioctyl phosphate), cyclic aluminum oxide isopropylate, and the like can be given. .

The compound containing a metal alkoxy group may be other than those described above, and may be, for example, a compound containing a hetero metal alkoxy group (including a compound containing a hetero metal oxoalkoxy group). The heterometallic alkoxy group-containing compound refers to a metal alkoxy group-containing compound having two or more different metal atoms and linked via an alkoxy group or an oxygen atom, or by a metal-metal bond or the like. When a compound containing a heterometallic alkoxy group is used, low-valent metal oxide-based particles composed of a composite oxide can be obtained.

The carboxyl group-containing compound used in the second production method is a compound having at least one carboxyl group in the molecule, for example, formic acid, acetic acid, propionic acid, isobutyric acid, caproic acid, caprylic acid, lauric acid Saturated fatty acids (saturated monocarboxylic acids) such as acids, myristic acid, palmitic acid, and stearic acid; unsaturated fatty acids (unsaturated monocarboxylic acids) such as acrylic acid, methacrylic acid, crotonic acid, oleic acid, and linolenic acid; oxalic acid Chain carboxylic acids such as saturated polycarboxylic acids such as malonic acid, succinic acid, adipic acid, suberic acid, β, β-dimethylglutaric acid, unsaturated polycarboxylic acids such as maleic acid and fumaric acid, and cyclohexanecarboxylic acid Cyclic saturated carboxylic acids such as acids, aromatic monocarboxylic acids such as benzoic acid, phenylacetic acid, and toluic acid; Aromatic carboxylic acids such as unsaturated polycarboxylic acids such as tallic acid, isophthalic acid, terephthalic acid, pyromellitic acid and trimellitic acid, acetic anhydride, maleic anhydride, and carboxylic anhydrides such as pyromellitic anhydride; Trifluoroacetic acid, o-chlorobenzoic acid, o-nitrobenzoic acid, anthranilic acid, p-aminobenzoic acid,
In a molecule such as anisic acid (p-methoxybenzoic acid), toluic acid, lactic acid, and salicylic acid (o-hydroxybenzoic acid), a hydroxyl group other than a carboxyl group, an amino group, a nitro group, an alkoxy group, a sulfonic acid group, and a cyano group A polymer having at least one unsaturated carboxylic acid as a polymer raw material, such as a compound having a functional group or an atomic group such as a halogen atom, an acrylic acid homopolymer, and an acrylic acid-methyl methacrylate copolymer. it can. Among these carboxyl group-containing compounds, in order to obtain particles having excellent dispersibility, a saturated carboxylic acid is preferred, and acetic acid is most preferred. When the carboxyl group-containing compound is a liquid, it can be used as a reaction solvent described later.

Regarding the carboxyl group-containing compound used in the second production method, the mixing ratio of the metal alkoxide and the carboxyl group-containing compound (carboxyl group-containing compound / metal alkoxide) is not particularly limited.
Valence n of metal atom M contained in metal alkoxide
Preferably, the lower limit is more than 0.8n, more preferably more than 2n, and the upper limit is preferably less than 10n.

The pyrrolidone compound used in the first and second production methods is a reducing agent that selectively reduces metal ions contained in the above-mentioned metal carboxylate or metal alkoxy group-containing compound to lower-valent metal ions. It works and its selectivity is very high.

The pyrrolidone compound is not particularly restricted but includes, for example, 2-pyrrolidone and 1-methyl-2-pyrrolidone, 1-ethyl-pyrrolidone obtained by substituting hydrogen at the N-position with various organic chains. 2-pyrrolidone, 1-isopropyl-2-pyrrolidone, 1-cyclohexyl-2-pyrrolidone, 1- (2-hydroxyethyl) -2-pyrrolidone, 1-stearyl-2-pyrrolidone, 1-[(N-diethylamino) propyl ] -2-pyrrolidone, 1-[(N
-Diethylamino) methyl] -2-pyrrolidone, 1-
(2-methoxyethyl) -2-pyrrolidone, 1- (2-
Phenylethyl) -2-pyrrolidone, 1-acetyl-2
-Pyrrolidone, N-vinylpyrrolidone and the like can be preferably exemplified, and the organic chain to be substituted is not particularly limited, but may be an alkyl group, a cycloalkyl group, an acyl group, an aralkyl group, an aryl group which may have a substituent. Are preferred. The pyrrolidone compound may be used alone or in combination of two or more.

The amount of the pyrrolidone compound varies depending on the valence of the metal atom in the metal carboxylate or the metal alkoxy group-containing compound used as a raw material and the valence of the metal atom of the low-valent metal oxide-based particles to be produced. However, usually, the pyrrolidone compound in a molar ratio of 0.1 to 10 with respect to the metal in the metal carboxylate or the metal alkoxy group-containing compound.
It is preferred that the content be doubled.

The mixture used in the first and second production methods of the present invention may further contain a reaction solvent and the like.

The amount of the reaction solvent used is not particularly limited, but in the first production method, the concentration of the metal carboxylate is 1 to the total amount of the metal carboxylate, the alcohol and the reaction solvent. It is preferable that the amount of the reaction solvent used is set so as to be 50% by weight. In the second production method, the reaction solvent is adjusted so that the concentration of the metal alkoxy group-containing compound is 1 to 50% by weight based on the total amount of the metal alkoxy group-containing compound, the carboxyl group-containing compound, and the reaction solvent. Is preferably set. Thereby, highly dispersible particles can be obtained economically.

As the reaction solvent, a solvent other than water, that is, a non-aqueous solvent is preferable. As the non-aqueous solvent, for example,
Hydrocarbons; halogenated hydrocarbons; alcohols (including phenols, polyhydric alcohols and derivatives thereof having a hydroxyl group, etc.); ethers and acetals;
Ketones and aldehydes; esters; derivative compounds in which the active hydrogens of all hydroxyl groups of polyhydric alcohols are substituted with alkyl groups or acetoxy groups; carboxylic acids and anhydrides thereof; silicone oils and mineral oils.

Examples of the hydrocarbon include amylbenzene, isopropylbenzene, ethylbenzene, octane, gasoline, xylenes, diethylbenzene, cyclohexane, cyclohexylbenzene, cyclohexene, cyclopentane, dimethylnaphthalene, cymenes,
Show brain oil, styrene, petroleum ether, petroleum benzine,
Solvent naphtha, decalin, decane, tetralin, turpentine, kerosene, dodecane, dodecylbenzene, toluene, naphthalene, nonane, pine oil, pinene, biphenyl, butane, propane, hexane, heptane, benzene, pentane, mesitylene, methylcyclohexane,
Examples include methylcyclopentane, p-menthane, ligroin, liquid paraffin, and the like.

Examples of the halogenated hydrocarbon include, for example, allyl chloride, 2-ethylhexyl chloride, amyl chloride, isopropyl chloride, ethyl chloride, naphthalene chloride, butyl chloride, hexyl chloride, methyl chloride, methylene chloride, o -Chlorotoluene, p-chlorotoluene,
Chlorobenzene, chloroform, carbon tetrachloride, 1,1-
Dichloroethane, 1,2-dichloroethane, 1,1-dichloroethylene, 1,2-dichloroethylene, 2,3-
Dichlorotoluene, 2,4-dichlorotoluene, 2,5
-Dichlorotoluene, 2,6-dichlorotoluene, 3,
4-dichlorotoluene, 3,5-dichlorotoluene, dichlorobutanes, dichloropropane, m-dichlorobenzene, o-dichlorobenzene, p-dichlorobenzene,
Dibromoethane, dibromobutane, dibromopropane,
Dibromobenzene, dibromopentane, allyl bromide, isopropyl bromide, ethyl bromide, octyl bromide, butyl bromide, propyl bromide, methyl bromide, lauryl bromide, 1,
1,1,2-tetrachloroethane, 1,1,2,2-tetrachloroethane, tetrachloroethylene, tetrabromoethane, tetramethylenechlorobromide, 1,1,1
-Trichloroethane, 1,1,2-trichloroethane,
Trichloroethylene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, bromochloroethane, 1-bromo-
Examples thereof include 3-chloropropane, bromonaphthalene, hexachloroethane, pentamethylenechlorobromide and the like.

As the above-mentioned alcohols (including phenols, polyhydric alcohols and derivatives thereof having a hydroxyl group), those similar to the alcohols used in the first production method can be preferably exemplified.

As the above ether and acetal,
For example, anisole, ethyl isoamyl ether, ethyl t-butyl ether, ethyl benzyl ether, epichlorohydrin, epoxybutane, crown ethers, cresyl methyl ether, propylene oxide, diisoamyl ether, diisopropyl ether, diethyl acetate, diethyl ether , Dioxane, diglycidyl ether, 1,8-cineole, diphenyl ether, dibutyl ether, dipropyl ether, dibenzyl ether, dimethyl ether, tetrahydropyran,
Tetrahydropifuran, trioxane, bis (2-chloroethyl) ether, vinylethylether, vinylmethylether, phenetole, butylphenylether, furan, furfural, methylal, methyl-t-
Examples thereof include butyl ether, methyl furan, monochlorodiethyl ether and the like.

Examples of the above ketones and aldehydes include acrolein, acetylacetone, acetaldehyde, acetophenone, acetone, isophorone, ethyl-n-butylketone, diacetone alcohol, diisobutylketone, diisopropylketone, diethylketone, cyclohexanone, di-n-propyl Ketone, holon, mesityl oxide, methyl-n-amyl ketone, methyl isobutyl ketone, methyl ethyl ketone, methyl cyclohexanone, methyl-n-butyl ketone, methyl-
Examples thereof include n-propyl ketone, methyl-n-hexyl ketone, and methyl-n-heptyl ketone.

Examples of the ester include diethyl adipate, dioctyl adipate, triethyl acetylcitrate, tributyl acetylcitrate, allyl acetoacetate, ethyl acetoacetate, methyl acetoacetate, methyl abietate, isoamyl benzoate, and benzoic acid Ethyl, butyl benzoate, propyl benzoate, benzyl benzoate, methyl benzoate, isoamyl isovalerate, ethyl isovalerate, isoamyl formate, isobutyl formate, ethyl formate, butyl formate, propyl formate, hexyl formate, benzyl formate, formic acid Methyl, tributyl citrate, ethyl cinnamate, methyl cinnamate, amyl acetate, isoamyl acetate, isobutyl acetate, isopropyl acetate, ethyl acetate,
2-ethylhexyl acetate, cyclohexyl acetate, acetate n
-Butyl, s-butyl acetate, propyl acetate, benzyl acetate, methyl acetate, methyl cyclohexyl acetate, isoamyl salicylate, benzyl salicylate, methyl salicylate, diamyl oxalate, diemyl oxalate, dibutyl oxalate, diethyl tartrate, dibutyl tartrate, stearic acid Amyl, ethyl stearate, butyl stearate,
Dioctyl sebacate, dibutyl sebacate, diethyl carbonate, diphenyl carbonate, dimethyl carbonate, amyl lactate, ethyl lactate, butyl lactate, methyl lactate, diethyl phthalate, dioctyl phthalate, dibutyl phthalate, dimethyl phthalate, γ-butyrolactone, propion Isoamyl acid, ethyl propionate, butyl propionate, benzyl propionate, methyl propionate, borates, dioctyl maleate, diisopropyl maleate, diethyl malonate, dimethyl malonate, isoamyl butyrate, isopropyl butylate, ethyl butyrate, butyric acid Examples thereof include butyl, methyl butyrate, and phosphates.

Examples of the derivative compounds in which the active hydrogens of all the hydroxyl groups of the polyhydric alcohols are substituted with an alkyl group or an acetoxy group include ethylene carbonate, ethylene glycol diacetate, ethylene glycol diethyl ether, ethylene glycol diglycidyl. Ether, ethylene glycol dibutyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol ethyl methyl ether, diethylene glycol diacetate, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol dibenzoate, diethylene glycol dimethyl ether , Diethylene glycol Monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol di-2-ethyl butyrate, triethylene glycol dimethyl ether, polyethylene glycol fatty acid diester, poly (oxyethylene) derivatives having no hydroxyl groups at both ends, both ends Examples thereof include a poly (oxypropylene) derivative having no hydroxyl group.

Hereinafter, the first manufacturing method of the present invention will be described.
explain in detail.

The first production method of the present invention is a method in which a mixture containing a metal carboxylate, an alcohol and a pyrrolidone compound described above is heated and reacted, and the mixture is reacted with a non-aqueous solvent or the like. It may further contain a solvent (excluding alcohol). The heating temperature is usually 50 ° C. or higher, and is preferably 100 ° C. or higher in order to obtain particles having high crystallinity, and is in the range of 100 to 300 ° C. in order to obtain particles having more excellent dispersibility. Is preferred.

The specific operation procedure of the first production method is not particularly limited. For example, 1) a method in which a mixture containing a metal carboxylate, an alcohol, and a pyrrolidone compound is prepared, and the mixture is heated and heated. 2)
A method of mixing a metal carboxylate and a pyrrolidone compound in a heated alcohol, 3) a method of mixing a metal carboxylate in a heated alcohol and a pyrrolidone compound,
4) a method in which a reaction solvent and a metal carboxylate are heated, and an alcohol and a pyrrolidone compound are mixed therein;
5) a method in which a reaction solvent, a metal carboxylate, and a pyrrolidone compound are heated, and an alcohol is mixed therein;
6) A method of mixing the respective components constituting the mixture in a heated state can be exemplified.

In the first production method, it is preferable that the water content of the mixture is small because the dispersibility of the obtained low-valent metal oxide-based particles increases. Specifically, it is preferable that the mixture contains only a small amount of water having a molar ratio of less than 4 with respect to the metal atoms in the metal carboxylate, and it is more preferable that the water has a molar ratio of less than 1;
It is particularly preferred that it is less than 0.5.

The heating reaction may be carried out under any of normal pressure, increased pressure, and reduced pressure. When the boiling point of the reaction solvent or the like is lower than the reaction temperature, the reaction may be performed using a pressure-resistant reactor. . Usually, the reaction temperature and the gas phase pressure during the reaction are lower than the critical point of the solvent, but the reaction can be performed under supercritical conditions.

Next, regarding the second production method of the present invention,
explain in detail.

The second production method of the present invention is a method in which a mixture containing a metal alkoxy group-containing compound, a carboxyl group-containing compound, and a pyrrolidone compound described above is heated and reacted. Etc. may be further included. The heating temperature is usually 50 ° C
As described above, in order to obtain particles having high crystallinity, 100
C. or higher is preferable, and in order to obtain particles having excellent dispersibility, the temperature is preferably in the range of 100 to 300C.

The specific operation procedure of the second production method is not particularly limited. For example, 1) a mixture containing a metal alkoxy group-containing compound, a carboxyl group-containing compound, and a pyrrolidone compound is prepared, and heated. 2) A method of mixing a metal alkoxy group-containing compound and a pyrrolidone compound with a heated carboxyl group-containing compound, 3) A mixing of a metal alkoxy group-containing compound with a heated carboxyl group-containing compound and a pyrrolidone compound Method 4) A method in which a reaction solvent and a metal alkoxy group-containing compound are heated beforehand, and a carboxyl group-containing compound and a pyrrolidone compound are mixed therein, and 5).
A method in which a reaction solvent, a metal alkoxy group-containing compound, and a pyrrolidone compound are heated and mixed with a carboxyl group-containing compound, 6) a method in which each component constituting the mixture is mixed in a heated state, and the like. be able to.

In the second production method, as in the first production method, it is preferable that the water content of the mixture is small, since the dispersibility of the resulting low-valent metal oxide-based particles increases. Specifically, it is preferable that the mixture contains only a small amount of water having a molar ratio of less than 1 with respect to the metal atom in the metal alkoxy group-containing compound. Preferably, it is particularly preferably less than 0.1.

The heating reaction of the second production method may be carried out under any of normal pressure, increased pressure and reduced pressure, as in the first production method. If it is also low, it may be carried out using a pressure-resistant reactor. Normal,
The reaction temperature and the gas phase pressure during the reaction are lower than the critical point of the solvent, but the reaction can be performed in a supercritical state.

As described above, the first embodiment according to the present invention is described.
Hereinafter, the low-valent metal oxide-based particles obtained by the second production method will be described in detail.

The low-valent metal oxide-based particles may be particles of any one of a single oxide, a solid solution oxide and a composite oxide. The low-valent metal oxide-based particles preferably show crystallinity based on the metal oxide by X-ray diffraction or electron beam diffraction. Usually, the primary particle diameter is 5 nm
In the above case, the X-ray diffraction method was used.
In the case of nm or less, it is possible to confirm the crystallinity by an electron diffraction method, and in the case of crystallinity, to identify the crystal structure and composition.

The low valent metal oxide particles preferably have a primary particle diameter of 1 to 100 nm. 1
The secondary particle diameter can be confirmed, for example, by any of the following methods.

The crystallite size D obtained by Wilson analysis or electron beam diffraction in X-ray diffraction is used.
w.

The primary particle diameter De obtained by observing a projected image of a particle with a transmission electron microscope (TEM), preferably a high-resolution TEM, for example, a field emission TEM, and observing its crystal lattice image and size. De is 5 according to the particle projection image.
The particle diameter of zero particles is measured and calculated as a number average particle diameter based on the arithmetic average. In the measurement of De, the reactant or the fine particle dispersion was dispersed with alcohol at a fine particle concentration of 0.1%.
It is preferable to use a sample diluted to wt% as a sample.

Specific surface area diameter Ds calculated by the following equation.

Ds = 6 / (ρ × s) (where, ρ: true specific gravity of low-valent metal oxide-based particles, s:
B. E. FIG. T. Specific surface area (m ² / g) of low-valent metal oxide-based particles measured by a method) Both Dw and De are more preferably 1 nm ≦
Dw (or De) ≦ 50 nm, and preferably 1 nm ≦ Dw (or De) ≦ 30 nm for excellent electronic properties, and 1 nm ≦ Dw (or De) ≦ 5 nm is preferred. If Dw and De are too small, ultraviolet shielding properties, conductivity, etc., will be reduced. On the other hand, if it is too large, transparency to visible light decreases.

The above Ds is more preferably 1 nm ≦ Ds
≦ 50 nm, and 1 nm ≦ for excellent electronic properties.
Ds ≦ 30 nm is preferable, and when the quantum size effect is functionally exhibited, 1 nm ≦ Ds ≦ 5 nm
Is preferable. If Ds is too small, the ultraviolet shielding property, the conductivity and the like are reduced. On the other hand, if it is too large, transparency to visible light decreases.

Further, the low-valent metal oxide-based particles
Light, in order to be a fine particle material excellent in electronic physical properties and magnetic functions, etc., and in order not to substantially affect the hue of the composition containing the particles having a high transparency, excellent in monodispersity Preferably, That is, it is important that the particle size distribution of the primary particle size is uniform, the degree of secondary aggregation is low, and the like. Specifically, the variation coefficient of the primary particle size is 30% or less. Preferably,
It is particularly preferred that it is 10% or less. Further, the secondary aggregation degree is preferably 10 or less, more preferably 5 or less, further preferably 2 or less, and particularly preferably 1. The secondary agglomeration refers to particles (secondary particles) in which primary particles are associated, and the degree of secondary agglomeration refers to the number of primary particles constituting the secondary particles. As another evaluation method of the secondary cohesiveness, a dispersed particle diameter (average dispersed particle diameter) is used.
Is measured, the average dispersed particle diameter is 200
nm or less, more preferably 70 n
m, and still more preferably 30 nm or less. The average dispersed particle size is measured by a device using a light scattering method. As a particularly preferred measuring device, a dynamic light scattering type particle size distribution measuring device LB-500 (manufactured by Horiba Ltd.) can be mentioned.

The shape of the low valent metal oxide particles is not particularly limited. Specific examples of shapes include flakes such as spherical, elliptical spherical, cubic, cuboid, polyhedral, pyramid, needle, columnar, rod-like, cylindrical, scaly, (hexagonal) plate-like, and supersaturated. Examples include dendrites and sculptures formed by preferentially extending the ridges and corners of the crystal under high-degree conditions.

It is preferable that the low-valent metal oxide-based particles are formed by bonding an alkoxy group or a carboxyl group, because of excellent dispersibility.

The low-valent metal oxide-based particles include an insulator material, a semiconductor material, an ion conductor material, a heat conductor material, a conductor (electron conductor) material, a light absorber material, a luminous material,
It can be used as ultrafine particles having various functions such as a phosphor material, a (optical) magnetic recording material, a nonlinear optical material, and a ferroelectric material. In particular, it is effective as a conductor (electron conductor) material such as electron conductive oxide particles. Examples of the electron conductive oxide-based particles include Ti, V, Mn, Sn, Sb,
Examples include oxide-based particles of metal atoms such as Cu and Ag and low-valent atoms such as Group 8 atoms. Low-valent metal oxide-based particles such as Cu ₂ O can be formed into an ink or paint, coated and heated in a reducing atmosphere to form a metal film. It is useful as an agent for improving the adhesion to a plastic film and also as an additive when forming a metal film with a metal paste.

[0062]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In the following, “parts by weight” may be simply referred to as “parts” for convenience.

Example 1 The inside of a pressure-resistant Hastelloy reactor (withstand pressure: 5 MPa / cm ² ) equipped with a stirrer, an addition port, a thermometer, a distillate gas outlet, and a nitrogen gas inlet, which can be heated from the outside, is installed. After purging with nitrogen, 18 parts of copper (II) acetate as a metal carboxylate, 135 parts of ethylenelenglycol monoethyl ether as an alcohol, and 20 parts of N-methylpyrrolidone were charged, and the resulting mixture (1) was stirred. The temperature was raised to 200 ° C.
After the internal temperature of the reactor reached 200 ° C., the temperature was maintained for 4 hours, and then cooled to obtain a reaction liquid containing fine particles.

The fine particles in the obtained reaction solution were separated by a centrifugal separator and dried in a vacuum, and the obtained powder was analyzed. As a result of XRD analysis, copper (I) oxide particles having a Dw of 31 nm, that is, , And Cu ₂ O fine particles.

[0065]

According to the method for producing low-valent metal oxide particles of the present invention, metal oxide particles containing a low-valent metal can be prepared with excellent monodispersibility, particle diameter, particle size distribution and composition. The present invention can provide a novel method for producing low-valent metal oxide-based particles which can be easily, stably and at low cost in a well-controlled state.

Claims (2)

[Claims] 1. A method for producing metal oxide particles, in which a mixture containing a metal carboxylate and an alcohol is heated and reacted, wherein the mixture further contains a pyrrolidone compound. A method for producing valence metal oxide particles. 2. A method for producing metal oxide particles wherein a mixture containing a metal alkoxy group-containing compound and a carboxyl group-containing compound is heated and reacted, wherein the mixture further contains a pyrrolidone compound. A method for producing low-valent metal oxide-based particles.