JP2008266745A - Method for manufacturing particulate dispersion and particulate dispersion of metal or metal compound manufactured by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a particulate dispersion of metal or metal compound which is dispersible to a small average grain size and is satisfactory in dispersibility, dispersion stability, etc., and to provide a particulate dispersion manufactured by using the manufacturing method and further, a particulate dispersion obtained by subjecting the particulate dispersion to solvent substitution. <P>SOLUTION: The method for manufacturing the dispersion dispersed with the particulates of the metal or the metal compound at the average grain size ≤100 nm under low vapor pressure liquid by bringing to contact the gas of the metal or the gas of the metal compound with the low vapor pressure liquid, in which an ester-based surface active agent is previously dissolved in the low vapor pressure liquid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a fine particle dispersion, and more specifically, when a metal gas or a metal compound dispersion is produced by a specific method, a specific compound is dissolved in a dispersion medium, thereby reducing the size of the dispersion. The present invention relates to a method for producing a fine particle dispersion in which the dispersibility of fine particles is greatly improved.

  Metal or fine particle dispersion of the metal compound is used for IC substrates, wiring of semiconductor elements, interlayer connection of semiconductor modules, formation of transparent conductive film, bonding of metal and nonmetal, color filter using colloid color of liquid, etc. Widely used.

  As a method for producing a fine particle dispersion of a metal or a metal compound, an aqueous solution of a metal compound in an oxidized state such as a gold salt, a platinum salt, a silver salt, or a palladium salt is reduced with a reducing agent to obtain a dispersion of metal fine particles. A method for obtaining the above has been widely known. However, in such a chemical method, only a fine particle dispersion containing substances remaining without reduction or impurities due to a reduction reaction can be prepared, and its use is limited. In addition, regarding this method, many methods for improving the dispersibility by changing the kind of reducing agent used, the purity of the substance used, the presence or absence of protective colloid, the pH and temperature at the time of preparation, etc. have been studied. However, none of them has reached a sufficient dispersion stability.

  Unlike the above chemical methods, physical methods such as a spark erosion method, a gas evaporation method, and a vacuum deposition method are known.

  The spark erosion method is a method for producing a fine particle dispersion by using a metal or the like to be dispersed as electrodes and generating a discharge between the electrodes in a dispersion medium. However, in this method, since it is difficult to contain a surfactant that is a good electrical conductor in the dispersion medium, there are cases where aggregation of fine particles cannot be suppressed.

In the gas evaporation method, a vapor of a metal or a metal compound to be dispersed is generated in the presence of an inert gas of 0.1 to 30 Torr (mmHg) (1.3 × 10 ¹ Pa to 4 × 10 ³ Pa). In this method, fine particles are produced in a gas phase, and immediately after production, the fine particles are collected in a solvent to produce a fine particle dispersion (see Patent Document 1). There is also a method of producing a fine particle dispersion by obtaining fine particles dispersed in an organic substance by allowing an organic gas that is liquid at room temperature to coexist in an inert gas, and then performing solvent exchange or the like. Are known.

  However, in these gas evaporation methods, it is difficult to make the average particle diameter uniform. In other words, the generated metal or metal compound vapor is cooled by collision with an inert gas atom to form fine particles, but the generated fine particles are likely to associate again in the inert gas and form a cluster. There was a problem caused by contact with gas.

  The vacuum deposition method deposits metal etc. on the surface of oil whose surface is covered with a surfactant, and the metal atoms etc. aggregate to form fine particles, and at the same time, the fine particles are protected with a surfactant to form fine particles. This is a method for preventing a mutual association and obtaining a dispersion in which fine particles are dispersed in oil (see Patent Document 2). In this method, since the fine particles are directly generated in the liquid, the problems caused by the contact between the gas and the gas, the association between the fine particles, and the like, which are problems in the gas evaporation method, are hardly generated.

  However, little research has been done on the above-mentioned surfactant in the vacuum deposition method. In the succinimide polyamine used as the surfactant in Patent Document 2, fine particles are not protected by the surfactant. There were still problems such as meeting and forming clusters. Therefore, even if the vacuum vapor deposition method, which is a relatively excellent method, is used, sufficient dispersibility and dispersion stability have not been provided to the fine particle dispersion of metal or metal compound.

JP 2002-121606 A International Publication WO2005 / 099941

  The present invention has been made in view of the above-described background art, and the problem is that a metal or a metal compound that can be dispersed with a small average particle diameter and has good dispersibility, dispersion stability, high concentration dispersibility, and the like. To provide a method for producing a fine particle dispersion, and to provide a fine particle dispersion produced by using the production method, and further, a fine particle dispersion obtained by subjecting the fine particle dispersion to solvent substitution. There is.

  As a result of intensive studies to solve the above problems, the present inventor has dissolved a specific surfactant in a dispersion medium when producing a metal gas or metal compound dispersion by a specific method. As a result, it was found that dispersibility and the like were improved, and the present invention was completed.

  That is, the present invention provides a dispersion in which fine particles of the metal or the metal compound are dispersed in the low vapor pressure liquid with an average particle size of 100 nm or less by bringing a metal gas or a metal compound gas into contact with the low vapor pressure liquid. The present invention provides a method for producing a fine particle dispersion, wherein an ester surfactant is dissolved in the low vapor pressure liquid.

  Moreover, this invention provides the fine particle dispersion of the metal or metal compound manufactured using the said manufacturing method.

  Further, the present invention provides a fine particle dispersion of a metal or metal compound, wherein the low vapor pressure liquid in the “fine particle dispersion of metal or metal compound” is replaced with another dispersion medium. It is to provide.

  According to the present invention, it is possible to disperse even fine particles having an extremely small average particle diameter, and even when dispersed to a small particle diameter, the dispersibility is excellent, the fine particles do not aggregate, and the dispersion stability is also excellent. In addition, a “fine particle dispersion of metal or metal compound” can be provided. Further, by substituting the obtained fine particle dispersion with a solvent, a “fine particle dispersion of metal or metal compound” having excellent dispersibility can be provided.

  Hereinafter, the present invention will be described, but the present invention is not limited to the following specific embodiments, and can be arbitrarily modified within the scope of the gist of the invention.

  The present invention relates to a method for producing a dispersion in which fine particles of the metal or the metal compound are dispersed in the low vapor pressure liquid by bringing a metal gas or a metal compound gas into contact with the low vapor pressure liquid. It is.

  The “metal or metal compound” dispersed by the method of the present invention is not particularly limited as long as it becomes a gas by heating or the like. In addition, “metal” includes “alloy”. As the “metal or metal compound” that becomes a fine particle in the production method of the present invention, a material that becomes an amorphous particle in a fine particle state has a high transparency because it has low light scattering when dispersed in a dispersion medium. This is preferable from the viewpoint of achieving dispersibility. Specifically, for example, metals such as Ag, Cu, Sn, Pd, In, Au, and Zn, alloys containing them, or metal compounds such as oxides and nitrides thereof are particularly preferable.

  The method of making the “metal or metal compound” gas is not particularly limited, and the “metal or metal compound” is heated by a known heating method. The heating temperature is not particularly limited as long as it is sufficient to be in a gaseous state, and also varies depending on the type of “metal or metal compound”, but is preferably 400 to 2000 ° C., more preferably 600 to 1700 ° C., 800-1600 degreeC is especially preferable, and 1000-1400 degreeC is still more preferable.

  In the present invention, a gas of “metal or metal compound” is brought into contact with a low vapor pressure liquid described later to form a dispersion. In this case, helium, argon, An inert gas such as nitrogen; it does not exclude the coexistence of organic gases such as a dispersion medium and a dispersion aid, but the effect of the present invention is to make a dispersed state at the liquid phase interface by bringing molecules into contact with the liquid. From the principle, there is no need for them to coexist.

There is no particular limitation on the pressure when forming a dispersion by bringing a gas of “metal or metal compound” into contact with a low vapor pressure liquid described later, but it is preferably 10 ⁻¹ Pa or less.

In these respects, the vapor of “metal or metal compound” is generated by interaction with an inert gas under a pressure of 0.1 to 30 Torr (mmHg) (1.3 × 10 ¹ Pa to 4 × 10 ³ Pa). The present invention is based on a completely different technical idea from the gas evaporation method in which the particles are aggregated to generate fine particles in the gas.

In the present invention, the pressure is preferably 10 ⁻¹ Pa or less, particularly preferably 10 ⁻² Pa or less. Moreover, it is preferable that it is 10 ^<-4 > Pa or more, and it is especially preferable that it is 10 ^<-3 > Pa or more. When the pressure is too high, that is, the degree of vacuum is poor, problems such as the need to increase the heating temperature and the influence of the gas intervening there may cause changes in the fine particles. If the pressure is too low, that is, if the degree of vacuum is unnecessarily high, the low vapor pressure liquid may volatilize, productivity may drop, or the vacuum pump may be overloaded.

In the present invention, "metal gas or metal compound gas" is brought into contact with a low vapor pressure liquid to disperse it in the low vapor pressure liquid. A “low vapor pressure liquid” refers to a liquid that has a low vapor pressure at the temperature at the time of dispersion and does not substantially volatilize at 10 ⁻³ Pa. If the vapor pressure is not low, the gas may evaporate and interact with the “metal gas or metal compound gas” to adversely affect dispersibility. The vapor pressure is preferably 10 ⁻¹⁰ Pa to ^{10 −5} Pa at 25 ° C., particularly preferably 10 ⁻⁸ Pa to 10 ⁻⁶ Pa at 25 ° C. The boiling point at 1 atm of such a low vapor pressure liquid is not particularly limited, but for the same reason as above, it is preferably 180 ° C. or higher, more preferably 200 ° C. or higher, particularly preferably 220 ° C. or higher, and further preferably 240 ° C. or higher. .

  The chemical structure of the low vapor pressure liquid is not particularly limited, but a liquid containing no active hydrogen such as a hydroxyl group, a secondary or primary amino group is preferable, a nonpolar liquid is more preferable, and aliphatic and / or aromatic Particularly preferred are group hydrocarbons. If it is a liquid containing active hydrogen or a polar liquid, “fine particles of metal or metal compound” may be oxidized, the function of the surfactant may be impaired, and dispersibility may deteriorate.

  Specific examples include alkyl naphthalene, alkyl diphenyl ether, polyphenyl ether, polyalkyl phenyl ether, silicone oil, polyalkyl siloxane, and fluorocarbon oil. Here, the alkyl group is not particularly limited, but preferably has 4 to 24 carbon atoms, more preferably has 8 to 22 carbon atoms, and particularly preferably has 12 to 20 carbon atoms. In the case of aliphatic and / or aromatic hydrocarbons, the total number of carbon atoms is preferably 14 or more, more preferably 20 or more, and particularly preferably 25 or more. These are used alone or in combination of two or more. A commercially available diffusion pump oil is also preferably used as the low vapor pressure liquid.

  In the method for producing a fine particle dispersion of the present invention, by bringing a gas into contact with a low vapor pressure liquid, the gas becomes solid fine particles and dispersed in the low vapor pressure liquid. An ester surfactant is dissolved in a vapor pressure liquid. Dispersion particles having a small average particle diameter can be formed by dissolving an ester surfactant, and a dispersion having excellent dispersibility, dispersion stability, high concentration dispersibility, etc. even with a small particle diameter. Can be obtained.

  The ester surfactant is not particularly limited as long as it is a compound having an ester group and having a surfactant activity, but a nonionic surfactant is preferable for good dispersibility. Furthermore, an ester of a polyhydric alcohol and a carboxylic acid is particularly preferable because of its high lipophilicity and high solubility in a low vapor pressure liquid, low reactivity and high stability. Compared with a sulfonic acid ester which is an ester of a strong acid, a carboxylic acid ester is a weak acid ester, and thus is particularly preferable from the viewpoint of low reactivity and high stability.

  As the carboxylic acid, a carboxylic acid having 8 to 28 carbon atoms is preferable, a carboxylic acid having 12 to 24 carbon atoms is more preferable, and a carboxylic acid having 15 to 22 carbon atoms is particularly preferable.

  Although it does not specifically limit as said polyhydric alcohol, Specifically, saccharides, such as ethylene glycol, polyethyleneglycol; propylene glycol, polypropylene glycol; glycerin, polyglycerin; pentaerythritol, trimethylolpropane; sucrose, glucose, etc. Preferred examples include sugar alcohols such as sorbit (reduced saccharides); cyclized products resulting from dehydration of sugar alcohols such as sorbitan. Among these, as the polyhydric alcohol, sugar alcohol or a cyclized product obtained by dehydration of the sugar alcohol is particularly preferable because it is excellent in dispersibility, dispersion stability, and high concentration dispersibility.

  The hydroxyl groups of the polyhydric alcohol may be substantially all esterified with an acid, or may not be all esterified and remain hydroxyl groups, but those having one or more hydroxyl groups remaining are preferred.

  Specific examples of ester surfactants include (poly) ethylene glycol fatty acid esters such as ethylene glycol monofatty acid ester, ethylene glycol difatty acid ester, polyethylene glycol monofatty acid ester, and polyethylene glycol difatty acid ester; propylene (Poly) propylene glycol fatty acid esters such as glycol monofatty acid ester, propylene glycol difatty acid ester, polypropylene glycol monofatty acid ester, polypropylene glycol difatty acid ester; glycerin monofatty acid ester, glycerin difatty acid ester, polyglycerin fatty acid ester ( Poly) glycerin fatty acid esters; sugar fatty acid esters such as sucrose fatty acid ester and glucose fatty acid ester; sorbi Sugar alcohol fatty acid esters such as fatty acid esters of glucose (glucose alcohol of glucose); fatty acid esters of “cyclized products of dehydration of sugar alcohol” such as sorbitan (cyclized product by dehydration of sorbit); polyoxyethylene glycerin fatty acid ester Polyoxyethylene fatty acid esters such as polyoxyethylene castor oil and polyoxyethylene hydrogenated castor oil; polyoxyethylene sugar alcohol fatty acid esters such as polyoxyethylene sorbite fatty acid ester; Oxyethylene chain-containing “fatty acid esters of cyclized product by dehydration of sugar alcohol” and the like are preferable. These are used alone or in combination of two or more.

  In the present invention, the ester surfactant is dissolved in the low vapor pressure liquid, but the concentration is not particularly limited and can be adjusted as appropriate, but with respect to 100 parts by mass of the low vapor pressure liquid, The ester surfactant is preferably 0.3 to 15 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 3 to 8 parts by mass. If the amount of the ester surfactant is too small, the dispersibility may be insufficient and the dispersion may not be performed satisfactorily. On the other hand, if the amount is too large, the viscosity of the dispersion may be too high.

  According to the method for producing a fine particle dispersion of the present invention, a gas of a metal or a metal compound is vapor-deposited at a liquid interface and taken into the liquid, and fine particles having an average particle size of nano order are generated and used. It is considered that the surfactant is directly involved in incorporation into the liquid, generation of fine particles in the liquid, control of the average particle diameter of the fine particles, suppression of association between the fine particles, and the like. Therefore, since the role and effect of the surfactant are very special, the knowledge and technique of the surfactant used for improving the dispersibility of general fine particles is hardly useful. That is, it is not possible to simply divert a surfactant known in other methods for producing fine particle dispersions to the present invention, or to simply divert a known dispersant to the present invention.

  Further, the fact that the fine particles are magnetic powder (ferromagnetic powder) means that the fine particles have crystallinity, and the technology for dispersing such crystalline particles or fine particles up to that is a non- It cannot be applied to technology that can disperse into crystalline nanoparticles.

  When the method for producing a fine particle dispersion of the present invention is used, a dispersion dispersed with an average particle size of 100 nm or less can be stably produced with extremely good dispersibility. Moreover, even if the average particle diameter is 10 nm or less, it can be stably dispersed. Therefore, the average particle size of the fine particles in the fine particle dispersion obtained using the production method of the present invention is usually 1 to 100 nm, preferably 2 to 50 nm, more preferably 3 to 20 nm, particularly preferably 4 to 15 nm, More preferably, it is 5-10 nm. The smaller the average particle size, the better because the effects of the present invention are easily exhibited.

  The shape of the fine particles of the metal or metal compound is not particularly limited and may be any of spherical, rod-like, plate-like, and irregular shapes, but is preferably irregular in terms of dispersibility. Also, the crystal structure of the fine particles is not particularly limited, but is preferably amorphous because the transparency of the dispersion and the dispersion described later is increased. Therefore, the production method of the present invention is suitable for forming amorphous fine particles. Particularly preferred as the fine particles formed by the production method of the present invention are amorphous amorphous particles.

  The concentration of the fine particles in the fine particle dispersion produced by the production method of the present invention is not particularly limited, but is preferably 1 to 90 parts by mass, more preferably 10 to 80 parts by mass with respect to 100 parts by mass of the fine particle dispersion. 20-70 mass parts is especially preferable. By using the present invention, a high-concentration fine particle dispersion can be obtained.

  The method for producing a fine particle dispersion of the present invention will be described in more detail using the production apparatus shown in FIG. However, FIG. 1 is an example of a specific apparatus used in the present invention, and the present invention is not limited to the apparatus using the apparatus shown in FIG.

  In FIG. 1, the chamber (1) has a drum shape rotating around the fixed shaft (2), and the inside of the chamber (1) is evacuated to high vacuum through the fixed shaft (2). The chamber (1) contains a low vapor pressure liquid (3) in which an ester-based surfactant is dissolved, and an ester-based interface is formed on the inner wall of the chamber (1) by the rotation of the drum-shaped chamber (1). A film (4) of low vapor pressure liquid (3) in which the activator is dissolved is formed. A container (6) for holding a metal or metal compound (5) is fixed inside the chamber (1). The metal or metal compound (5) is heated to a predetermined temperature, for example, by passing a current through a resistance wire, and is released into the chamber (1) as a gas.

  The entire outer wall of the chamber (1) is cooled by the water flow (8). The atoms (9) released from the heated “metal or metal compound (5)” into the vacuum are taken in from the surface of the film (4) of the low vapor pressure liquid (3) in which the ester surfactant is dissolved. As a result, fine particles (10) are formed. Next, the low vapor pressure liquid (3) in which such fine particles (10) are dispersed is transported into the low vapor pressure liquid (3) at the bottom of the chamber (1) as the chamber (1) rotates, At the same time, a new “low vapor pressure liquid (3) membrane (4)” is fed to the top of the chamber (1).

  By continuing this process, the low vapor pressure liquid (3) at the bottom of the chamber (1) becomes a dispersion in which "metal or metal compound (5)" is dispersed at a high concentration.

  In the present invention, a fine particle dispersion is produced by directly incorporating a metal gas or a metal compound gas into a low vapor pressure liquid in which an ester surfactant is dissolved. The present invention is not limited to the following actions and principles, but is considered as follows. That is, metal gas or metal compound gas is directly taken into the low vapor pressure liquid without agglomerating in the gas phase, and agglomeration occurs in the low vapor pressure liquid to have a certain average particle diameter. At that time, the aggregated particles are believed to be surrounded by the surfactant and stabilized as nanoparticles. At that time, it is considered that the above-described ester surfactant, in particular, wraps the aggregated particles more quickly, suppresses the association with each other more strongly, and stabilizes them as nanoparticulates.

  The fine particle dispersion obtained by using the production method of the present invention uses the low vapor pressure liquid as a dispersion medium, but if the low vapor pressure liquid is used as a dispersion medium, the subsequent use If it is not suitable for the above, the low vapor pressure liquid in the “fine particle dispersion of metal or metal compound” may be replaced with another dispersion medium to prepare “fine particle dispersion of metal or metal compound”. preferable. That is, the low vapor pressure liquid is preferably one that is suitable from the viewpoint of dispersibility, but is preferably replaced with “another dispersion medium” that is suitable for the application in which the fine particles are used.

  The “other dispersion medium” is not particularly limited, and can be selected according to the use of the dispersion. For example, hydrocarbon solvents such as toluene, xylene and n-hexane; ester solvents such as ethyl acetate; glycol solvents such as propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate and dipropylene glycol monoethyl ether; acetone And ketone solvents such as methyl ethyl ketone and cyclohexanone. These may be used alone or in combination of two or more.

  As a method of substituting the low vapor pressure liquid with another dispersion medium, a known solvent replacement / dispersion medium replacement method is used. The fine particles obtained in the present invention can maintain a stable dispersion state even when the dispersion medium is replaced, during dispersion medium replacement, and during subsequent storage of the dispersion.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples unless it exceeds the gist.

Example 1
<Preparation of Silver (Ag) Fine Particle Dispersion-1>
Using 380 g of Lion diffusion pump oil (A) (manufactured by Lion Corporation) as a low vapor pressure liquid, 20 g of Ionette S85 (manufactured by Sanyo Kasei Kogyo Co., Ltd.) (active ingredient 100%) as an ester surfactant was added and stirred. Lion diffusion pump oil (A) is an alkylnaphthalene having an alkyl group having 12 to 16 carbon atoms. Ionette S85 is a sorbitan fatty acid ester mainly composed of sorbitan monooleate.

A dispersion was produced using the apparatus shown in FIG. 20 g of silver (Ag) grains (manufactured by Tokuru Honten Co., Ltd .: purity 99.99%) was put in the container (6), and the liquid was put in the rotating drum type chamber (1). By suctioning with a vacuum pump, the pressure in the chamber (1) reached 10 ⁻³ Pa. Next, the chamber (1) is rotated while being cooled with the water flow (7), and an electric current is supplied to the heater provided in the lower part of the container (6), and the current value is increased until the silver (Ag) is dissolved and evaporated. It was.

  Silver (Ag) grains dissolve, and the silver (Ag) gas comes into contact with the surface of the dispersion medium (the surface of the low vapor pressure liquid (3) film (4) in which the ester surfactant is dissolved). A silver (Ag) nanoparticle dispersion was formed by being incorporated into the activator.

  As shown in FIG. 2, it was confirmed by observation with a transmission electron microscope that particles having an average particle diameter of about 5 to 15 nm were dispersed without agglomeration.

Example 2
<Preparation of copper (Cu) fine particle dispersion>
It replaced with the silver (Ag) grain of the manufacturing method of Example 1, and it carried out by the method similar to Example 1 except having used the copper (Cu) grain (Furuuchi Chemical Co., Ltd. product: purity 99.99%).

  As shown in FIG. 3, it was confirmed by transmission electron microscope observation that particles having an average particle diameter of about 2 to 10 nm were dispersed without agglomeration.

Example 3
<Preparation of tin (Sn) fine particle dispersion>
It replaced with the silver (Ag) grain of the preparation method of Example 1, and it carried out by the method similar to Example 1 except having used the tin (Sn) grain (Furuuchi Chemical Co., Ltd. product: purity 99.99%).

  As shown in FIG. 4, it was confirmed by transmission electron microscope observation that particles having an average particle diameter of about 10 to 20 nm were dispersed without agglomeration.

Example 4
<Preparation-2 of silver (Ag) fine particle dispersion-2>
In Example 1, it replaced with Ionette S85 (manufactured by Sanyo Kasei Kogyo Co., Ltd.) as an ester surfactant, and was the same as Example 1 except that Azisper PA111 (manufactured by Ajinomoto Fine Techno Co.) (active ingredient 100%) was used. The method was performed. Addispar PA111 is a higher fatty acid ester.

  By observation with a transmission electron microscope, it was confirmed that particles having an average particle diameter of about 2 to 15 nm were dispersed without aggregation.

Comparative Example 1
In Example 1, it replaced with Ionette S85 (made by Sanyo Kasei Kogyo Co., Ltd.) as surfactant, and performed by the method similar to Example 1 except having used succinimide polyamine.

  However, it was confirmed by observation with a transmission electron microscope that the particles were aggregated with each other. Further, it was observed visually that the fine particles had settled and accumulated, and a good dispersion could not be obtained.

Comparative Example 2
In Example 1, it replaced with Ionette S85 (made by Sanyo Chemical Industries) as surfactant, and carried out by the same method as Example 1 except having used Disperbyk-102 (made by Big Chemie). Disperbyk-102 is a copolymer having acidic groups.

  However, it was confirmed by observation with a transmission electron microscope that the particles were aggregated with each other. Further, it was observed visually that the fine particles had settled and accumulated, and a good dispersion could not be obtained.

  As is clear from the above results, in Examples 1 to 4 of the present invention, since an ester surfactant was used, the association between fine particles was suppressed, and fine particles having good dispersibility and dispersion stability. A dispersion could be obtained.

  On the other hand, those using no ester surfactant (Comparative Example 1 and Comparative Example 2) were all poor in dispersibility and dispersion stability as compared with Examples 1 to 4.

  Dispersions and dispersions obtained by using the method for producing a fine particle dispersion of the present invention include IC substrates, wiring of semiconductor elements, interlayer connection of semiconductor modules, formation of transparent conductive films, and between metal and nonmetal. It is widely used for bonding, color filters using the colloidal color of liquid, and the like.

It is a schematic sectional drawing of an example of the apparatus used for the manufacturing method of the fine particle dispersion of this invention. It is a transmission electron micrograph of the fine particles in the silver (Ag) fine particle dispersion produced in Example 1 (magnification: 100,000 times). It is a transmission electron micrograph of the fine particles in the copper (Cu) fine particle dispersion produced in Example 2 (magnification: 100,000 times). It is a transmission electron microscope photograph of the fine particles in the tin (Sn) fine particle dispersion produced in Example 3 (magnification: 100,000 times).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chamber 2 Fixed axis | shaft 3 Low vapor pressure liquid in which ester type surfactant was dissolved 4 Low vapor pressure liquid film in which ester type surfactant was dissolved 5 Metal or metal compound 6 Container 7 Water flow 8 Direction of rotation 9 Atom 10 Fine particles of “metal or metal compound”

Claims (8)

  A method of producing a dispersion in which fine particles of the metal or the metal compound are dispersed in the low vapor pressure liquid with an average particle size of 100 nm or less by bringing the metal gas or the metal compound gas into contact with the low vapor pressure liquid. A method for producing a fine particle dispersion, wherein an ester surfactant is dissolved in the low vapor pressure liquid. The method for producing a fine particle dispersion according to claim 1, wherein the metal gas or the metal compound gas is contacted with the low vapor pressure liquid under a pressure in the range of 10 ^-4 Pa to 10 ^-1 Pa.   The method for producing a fine particle dispersion according to claim 1 or 2, wherein the ester-based surfactant is an ester of a polyhydric alcohol and a carboxylic acid.   The method for producing a fine particle dispersion according to claim 3, wherein the polyhydric alcohol is sugar alcohol or a cyclized product obtained by dehydration of sugar alcohol.   The method for producing a fine particle dispersion according to claim 3 or 4, wherein the carboxylic acid is a carboxylic acid having 12 to 24 carbon atoms.   6. The method for producing a fine particle dispersion according to claim 1, wherein the fine particles of the metal or the metal compound are amorphous fine particles.   A fine particle dispersion of a metal or a metal compound produced by using the method for producing a fine particle dispersion according to any one of claims 1 to 6.   8. A metal or metal compound fine particle dispersion, wherein the low vapor pressure liquid in the metal or metal compound fine particle dispersion according to claim 7 is replaced with another dispersion medium.