JPWO2007108217A1 - Nanoparticle dispersion manufacturing method, nanoparticle dispersion and nanoparticle dispersion manufacturing apparatus - Google Patents

Abstract

A method for producing a nanoparticle dispersion in which nanoparticles having a particle diameter of 100 nm or less are directly dispersed in a reactive solvent that is a precursor of the polymer, and using a bead mill 2 having a bead separation mechanism 13 for separating beads. In addition, ultrafine beads having a particle diameter of 1 to 50 μm are used for the beads, and the reactive solvent is a dispersion medium containing one or more substances selected from monomers, dimers, trimers, and oligomers. Then, a dispersing agent for binding the dispersion medium molecules to the surface of the nanoparticles is added, and the nanoparticles modified with the surface modification of the nanoparticles in the reactive solvent by the bead mill are aggregated to a size of primary particles of 100 nm or less. Disperse uniformly.

Description

  The present invention relates to a method for producing an electronic material or a nanoparticle dispersion indispensable for providing a novel material, a nanoparticle dispersion, a nanoparticle dispersion production apparatus, a method for producing a nanocomposite material using the nanoparticle dispersion, and It relates to nanocomposite materials.

  Currently, in the application of electronic materials, there is a strong demand for nanoparticle materials dispersed to a size of several tens of nanometers or less. Various methods have been developed for the production of nanoparticles. These methods include a breakdown method that promotes atomization by breaking a lump and a build-up method that synthesizes nanoparticles by a gas phase method or a liquid phase method. Can be broadly classified. Nanoparticle production methods using a breakdown method and a buildup method each have advantages and disadvantages, and are still under development.

  In both the breakdown method and the build-up method for producing nanoparticles, the particles tend to aggregate as the particle diameter decreases, and it is not easy to produce single dispersed particles. Therefore, at present, many methods are used to disperse nanoparticles in a dispersion medium while dispersing particles using a disperser under wet conditions. The disperser used here stirs the agglomerated particles, the dispersion medium, and the fine beads that are the agitated particles (media) in the container, so that they collide with the agglomerated particles through the agitated particles and give shear energy. Dispersed and called by the name of bead mill. The present applicants are conducting developmental research on bead mills, obtaining patents, and manufacturing and selling products (see, for example, Non-Patent Document 1 and Patent Document 1).

In the conventional wet pulverization method using the stirring particles including the bead mill, the stirring particles are worn and impurities are mixed, and the dispersion of the nanoparticles into the dispersion medium is insufficient. There has been proposed a technique of wet dispersion using a particle having a primary particle size 200 to 10,000 times larger than the primary particle size (see, for example, Patent Document 2). In addition, as an invention related to nanoparticles, a technique related to a method for producing a composite material in which nanoparticles are dispersed in a polymer is also disclosed (see, for example, Patent Document 3).
Japanese Patent No. 3703148 JP 2005-87972 A JP 2006-15259 A Mitsuru Suin, Takashi Tahara, J. Soc. Powder Technology. , Japan, 41, 578-585 (2004).

  In the method for producing a nanocomposite material described in Patent Document 3, an organic phase containing inorganic nanoparticles is produced, a polymer is added thereto, and then the solvent in the organic phase is removed to produce the nanocomposite material. Is the method. This method requires many steps for production and takes time. The bead mill is an excellent wet disperser as described in Patent Documents 1 and 2 and Non-Patent Document 1, and if nano particles can be dispersed in a monomer using this, a nanocomposite material can be produced. Can be done very easily. However, as described in Non-Patent Document 1, the wet disperser cannot obtain desired nanoparticles unless the dispersion conditions are properly set, and cannot efficiently produce nanoparticles. It is. For these reasons, although a technique for dispersing nanoparticles in alcohol or the like is currently disclosed, a technique for directly dispersing nanoparticles in a polymer raw material such as a monomer has not been established. In addition to technology for directly dispersing nanoparticles in polymer raw materials such as monomers, development of an apparatus capable of producing a nanoparticle dispersion in a short time and efficiently is also awaited.

  An object of the present invention is to use a nanoparticle dispersion production method, a nanoparticle dispersion, and a nanoparticle dispersion that can easily produce a nanoparticle dispersion using a reactive solvent that is a polymer precursor as a dispersion medium. It is providing the manufacturing method of a nanocomposite material, and a nanocomposite material. Moreover, it aims at provision of the nanoparticle dispersion liquid manufacturing apparatus which can manufacture a nanoparticle dispersion liquid efficiently in a short time.

  The present invention aims to produce a polymer composite material containing nanoparticles having a particle size of 100 nm or less, and uses a bead mill to uniformly disperse the nanoparticles directly in a reactive solvent that is a precursor of the polymer. A method for producing a liquid, wherein a bead mill including a bead mill having a rotor, a stator, and a bead separation mechanism for separating beads as stirring particles by centrifugation is used in the bead mill, and the bead mill has a particle diameter of 1 to 50 μm. And the reactive solvent is a dispersion medium containing one or more substances selected from the following group (A), and the dispersion medium is used for bonding the dispersion medium molecules to the nanoparticle surface in the dispersion process. The agent is added, and the surface modification of the nanoparticles and the aggregated nanoparticles are uniformly dispersed to the size of primary particles of 100 nm or less in the reactive solvent by the bead mill. Runano is a manufacturing method of the particle dispersion. (A) Monomer, dimer, trimer, oligomer

Further, the present invention provides the method for producing a nanoparticle dispersion, wherein the nanoparticle is highly cohesive silicon dioxide, and further corresponds to the total surface area of the silicon dioxide to 2 × with respect to 1 g of the silicon dioxide. 10 ⁻⁴ to 1 × 10 ⁻² mol of polymerization inhibitor is added to the reactive solvent, and the surface modification of the nanoparticles and the aggregated nanoparticles are performed in the reactive solvent by the bead mill, and the size of the primary particles is 100 nm or less It is characterized by being uniformly dispersed.

  Further, the present invention provides the method for producing a nanoparticle dispersion, wherein the dispersant has a group having an affinity for the nanoparticle and a group having an affinity for and reacting with the dispersion medium. To do.

  In the method for producing a nanoparticle dispersion, the present invention is characterized in that the concentration of the nanoparticle in the dispersion medium is 0.1 to 50% by weight.

  Further, the present invention provides the method for producing a nanoparticle dispersion, wherein the bead separation mechanism for separating the beads that are stirring particles by the centrifugal separation has a separator, wherein the separator has a diameter d and the stator has an inner diameter D. , D / D is 0.5 to 0.9.

  Moreover, this invention is a manufacturing method of the said nanoparticle dispersion liquid, The weight ratio with respect to the said nanoparticle of the said dispersing agent is 0.01-10.0, It is characterized by the above-mentioned.

  Further, the present invention uses a bead mill having a rotor, a stator, and a bead separation mechanism for separating beads that are stirring particles by centrifugation, a nanoparticle having a primary particle size of 100 nm or less, a dispersion medium, a dispersant, and a particle size Stir particles having a particle size of 1 to 50 μm to disperse the nanoparticles in the dispersion medium, and the particle diameter of the particles in the dispersion, the viscosity of the dispersion, the stirring torque of the beads mill, the stirring power of the beads mill, and dispersion Nanoparticle dispersion characterized in that at least one of the light transmittances of the liquid is measured over time during the dispersion operation, and the dispersion operation is terminated when the measured value is detected to be a predetermined value. It is a manufacturing method of a liquid.

  Further, the present invention provides the method for producing a nanoparticle dispersion, wherein the particle diameter of the particles in the dispersion, the viscosity of the dispersion, the stirring torque of the beads mill, the stirring power of the beads mill, the light transmittance of the dispersion It is characterized in that the measurement is performed online.

  Further, in the method for producing a nanoparticle dispersion according to the present invention, the measurement performed during the dispersion operation is a particle diameter of the particles in the dispersion, and the measured value is a 90% passing particle diameter of the particles. And

  In the method for producing a nanoparticle dispersion, the dispersion medium includes at least one of a monomer, a dimer, a trimer, and an oligomer.

  Further, the present invention uses a bead mill having a rotor, a stator, and a bead separation mechanism for separating beads that are stirring particles by centrifugation, a nanoparticle having a primary particle size of 100 nm or less, a dispersion medium, a dispersant, and a particle size Stir particles having a particle size of 1 to 50 μm to disperse the nanoparticles in the dispersion medium, and the particle diameter of the particles in the dispersion, the viscosity of the dispersion, the stirring torque of the beads mill, the stirring power of the beads mill, and dispersion Measuring at least one of the light transmittances of the liquid over time during the dispersion operation, and ending the dispersion operation when it is detected that the amount of change in the measured value per time has reached a predetermined value. It is the manufacturing method of the nanoparticle dispersion liquid characterized.

  In the method for producing a nanoparticle dispersion, the dispersion medium includes at least one of a monomer, a dimer, a trimer, and an oligomer.

  Moreover, this invention is a nanoparticle dispersion liquid manufactured by the method of Claim 1.

  The present invention also provides a bead mill having a rotor, a stator, and a bead separation mechanism for separating beads as stirring particles by centrifugation, stirring particles having a particle diameter of 1 to 50 μm, at least a particle size distribution measuring means, and a dispersion liquid. Any one of a viscosity measuring means, a stirring torque measuring means for the bead mill, a stirring power measuring means for the bead mill, and a light transmittance measuring means for the dispersion, It is.

  Further, the present invention provides the nanoparticle dispersion production apparatus further comprising: a raw material adjustment device disposed outside the bead mill; and a pump connected to the raw material adjustment device and the bead mill to pump the dispersion. It is characterized by including.

  In the nanoparticle dispersion production apparatus, the present invention further includes a particle size distribution measuring unit for the particles, a viscosity measuring unit for the dispersion, a stirring torque measuring unit for the bead mill, a stirring power measuring unit for the bead mill, and the Data processing means capable of calculating the amount of change per hour of the measured value measured by at least one of the means for measuring the light transmittance of the dispersion.

  In addition, the present invention polymerizes the nanoparticle dispersion produced by the method according to claim 1 or adds a polymerization initiator to the nanoparticle dispersion produced by the method according to claim 1, A method for producing a nanocomposite material comprising polymerizing a solution to produce a nanocomposite material.

  Moreover, this invention is the nanocomposite material manufactured by the method of Claim 17.

  Furthermore, the present invention provides a nanocomposite material obtained by the method of claim 17, which has transparency and has one or more properties of flame retardancy, heat resistance, solvent resistance, gas barrier properties, and ultraviolet blocking properties. Materials for automobiles, cosmetics, and optical materials.

  By using the method for producing a nanoparticle dispersion of the present invention, a nanoparticle dispersion using a reactive solvent that is a polymer precursor as a dispersion medium can be easily produced. Moreover, a nanocomposite material can be easily manufactured. Moreover, a nanoparticle dispersion can be efficiently produced in a short time by using the nanoparticle dispersion production apparatus of the present invention.

1 is a diagram showing a schematic configuration of a nanoparticle dispersion production apparatus 1 as an embodiment of the present invention. It is a figure which shows schematic structure of the experimental apparatus 20 used in the Example of this invention. It is a figure which shows the measurement result of the particle diameter distribution of Example 2 of this invention. It is a figure which shows the measurement result of the light transmittance of the dispersion liquid of Example 6 of this invention. It is a figure which shows the measurement result of the reach | attainment particle diameter of Examples 15-23 of this invention. It is a figure which shows the measurement result of the particle diameter distribution of Example 24 of this invention. It is a figure which shows the result of having measured the light transmittance of the dispersion liquid of Example 24 of this invention. It is a figure which shows the measurement result of the particle diameter distribution of Example 42 of this invention. It is a figure which shows the result of having measured the light transmittance of the dispersion liquid of Example 42 of this invention.

  In the development process of the method for producing a nanoparticle dispersion according to the present invention, a nanoparticle dispersion slurry is produced using a reactive solvent that is a polymer precursor, such as a monomer, as a dispersion medium using a bead mill. In order to solve this phenomenon, it was found that the particles were aggregated in a state including a reactive solvent that is a polymer precursor such as a monomer, and the nanoparticles could not be sufficiently dispersed. Using a bead mill equipped with a bead separation mechanism for separating beads that are stirring particles, a method for producing a nanoparticle dispersion was studied. As a result, a dispersion medium, which is a reactive solvent containing one or more substances selected from nanoparticles, monomers, dimers, trimers, and oligomers having a primary particle size of 100 nm or less, and the dispersion medium molecules in the dispersion process By dispersing the dispersing agent for binding to and the stirring particles having a particle diameter of 1 to 50 μm to disperse the nanoparticles and reacting the dispersed nanoparticles with the dispersion medium to modify the surface, the nanoparticles are sufficiently It was found that a dispersed dispersion can be obtained. In addition, for nanoparticles with strong cohesive properties, by adding a polymerization inhibitor to the dispersion medium that is a reactive solvent, the nanoparticles are dispersed and the dispersed nanoparticles are reacted with the dispersion medium to modify the surface. It was found that a dispersion liquid in which nanoparticles are sufficiently dispersed can be obtained.

  In the production of the nanoparticle dispersion according to the present invention, a stirring particle having a particle diameter of 1 to 50 μm is used to manufacture the nanoparticle dispersion, and therefore, the stirring particle can be separated from the raw material slurry and has excellent dispersion performance. Must be a bead mill. The type is not particularly limited as long as it is a medium agitating mill that satisfies this requirement, but a bead mill that includes a rotor, a stator, and a bead separation mechanism that separates beads that are agitated particles by centrifugal separation satisfies the above conditions and is preferable. Can be used for Further, the bead mill has a separator that separates beads that are stirring particles, and when the diameter of the separator is d and the inner diameter of the stator is D, d / D is more preferably 0.5 to 0.9. If it is a bead mill which has such a shape, a nanoparticle dispersion liquid can be manufactured more efficiently in a short time. Here, the raw material slurry means particles and a dispersion medium such as aggregated particles and dispersed particles, or a mixture of particles, a dispersion medium and a dispersant.

The raw material powder that can be used in the method for producing a nanoparticle dispersion of the present invention is not limited to a specific raw material powder, as long as the primary particle diameter is nanoparticles having a size of 100 nm or less. The reason why the raw material powder is limited to nanoparticles having a primary particle diameter of 100 nm or less is that in the production of the nanoparticle dispersion of the present invention, fine nanoparticles do not pulverize a mass to obtain nanoparticles. Examples of the raw material powder applicable to the present invention include the following. As metal oxides, magnesium oxide, aluminum oxide, silicon dioxide, titanium oxide, vanadium oxide, chromium oxide, manganese dioxide, iron oxide, magnetite, cobalt oxide, nickel oxide, copper oxide, zinc oxide, yttrium oxide, zirconium oxide, oxidation Examples include indium, tin oxide, hafnium oxide, tungsten oxide, cerium oxide, niobium oxide, and indium tin oxide. In addition, barium titanate, strontium titanate, indium oxide-tin oxide, boron nitride, silicon nitride, silicon carbide, zinc sulfide, cadmium sulfide, cadmium selenide, antimony oxide-tin oxide, (LaAlO ₃ ) 0.3- (Sr ₂ AlTaO ₈ ) 0.7, LaAlO ₃ , SrTiO _3, SrLaAlO _4, YVO ₄ , MgAlO ₄ are exemplified.

  The concentration of the raw material powder in the dispersion medium is preferably 0.1 to 50% by weight. When the concentration of the raw material powder in the dispersion medium is less than 0.1% by weight, the particle concentration (solid content concentration) in the dispersion medium is small, which is not efficient as a method for producing a dispersion. On the other hand, if the concentration of the raw material powder in the dispersion medium exceeds 50% by weight, the particle concentration is too high and the dispersion of the particles tends to be insufficient due to the increase in viscosity. In addition, it takes time to disperse the particles.

  A dispersion medium that can be used in the method for producing a nanoparticle dispersion of the present invention is a reactive solvent containing one or more substances selected from monomers, dimers, trimers, and oligomers that are polymer precursors. Can be used. Thus, a nanocomposite material using a polymer as a dispersion medium can be easily obtained using the nanoparticle dispersion liquid of the present invention. The dispersion medium may be a single component such as a monomer or a dimer, or may be a mixture of a plurality of components such as a monomer and a dimer, or a dimer, a trimer, and an oligomer. Further, another dispersion medium may be mixed with the monomer.

  Examples of the dispersion medium applicable to the present invention include the following. Vinyl monomers include styrene, acrylates, (meth) methacrylates, acrylamide derivatives, and other unsaturated compounds. Examples of acrylates include methyl acrylate, ethyl acrylate, butyl acrylate, acrylic Examples include 2-ethylhexyl acid, isobutyl acrylate, 2-methoxyethyl acrylate, 2-hydroxyethyl acrylate, and ethylene carbonate.

  Examples of the (meth) methacrylate vinyl monomer include methacrylic acid, methyl methacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid 2 -Hydroxyethyl, 4-hydroxybutyl methacrylate, 2-hydroxypropyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, isodecyl methacrylate, ethyl methacrylate methyl methacrylate copolymer, ethyl methacrylate resin, octadecyl methacrylate, methacryl Diethylaminoethyl acid, stearyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, tridecyl methacrylate, glycidyl methacrylate, methacrylate Versyl acid, 2-phenoxymethyl methacrylate, trimethylolpropane trimethacrylate, isobornyl (meth) acrylate, dicyclopentanyl methacrylate, dicyclopentenyloxyethyl (meth) acrylate, dipentaerythritol (penta) hexaacrylate, tripropylene Examples include glycol diacrylate and polyethylene glycol diacrylate.

  Examples of the vinyl monomer of the acrylamide derivative include methacrylamide, acroyl morpholine, N-isopropylacrylamide, N, N-dimethylylacrylamide, and N, N-dimethylaminopropylacrylamide.

  Examples of vinyl monomers as other unsaturated compounds include isoprene sulfonic acid soda, N-vinylacetamide, N-vinylformamide, (poly) allylamine, and (poly) p-vinylphenyl.

  Non-vinyl monomers include polyvalent carboxylic acids, polyhydric alcohols, and polyamines. Examples of polyvalent carboxylic acids include 1,4-cyclohexanecarboxylic acid, CIC acid / Bis-CIC acid, 2,6- An example is naphthalenedicarboxylic acid (dimethyl).

  Examples of the polyhydric alcohol include 1,4-cyclohexanedimethanol, 4,4′-dihydroxybiphenyl, dimethylolbutanoic acid, hydrogenated bisphenol A, neopentyglycol, and 1,3-propadiol.

  Examples of the polyvalent amine include m-xylylenediamine, 1,4-diaminobutane, norbornanediamine, and 1,3-bis (aminomethyl) cyclohexane. Other non-vinyl monomers include 2,2-bis (p-cyanatophenyl) propane.

  The dispersant only needs to have a function of binding the dispersion medium molecules to the surface of the nanoparticles during the dispersion process, and the dispersion has a group having affinity with the nanoparticles and a group having affinity and reaction with the dispersion medium. An agent can be preferably used. The dispersant may be added to and mixed with the raw material powder in advance and then added to the dispersion medium, or the raw material powder may be added after the dispersant is added and mixed with the dispersion medium. Such a dispersant is not particularly limited as long as it satisfies the above-mentioned conditions. For example, a silane coupling agent having a functional group to be imparted, a titanate coupling agent, and an organic chromium coupling. An agent can be mentioned. For example, when a coupling agent is used for particle surface treatment as a nanoparticle dispersant, and the functional group to be imparted to the coupling agent is an amino group, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) ) -Γ-aminopropyl-trimethoxysilane, n (dimethoxymethylsilylpropyl) -silane coupling agent having an amino group such as ethylenediamine, titanate type having an amino group such as isopropyltri (N-amidoethylaminoethyl) titanate An organic chromium coupling agent having an amino group such as a coupling agent or a chromic chloride compound can be used.

  Other vinyl-based silane coupling agents include allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, trichlorovinylsilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2 -Methoxyethoxy) silane is exemplified.

  Epoxy-based silane coupling agents include diethoxy (glycidyloxypropyl) methylsilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyl. Examples include diethoxysilane and 3-bridoxypropyl triethoxysilane. Examples of the styrene-based silane coupling agent include p-styryltrimethoxysilane.

  Examples of the methacryloxy-based silane coupling agent include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane. . Examples of the acryloxy silane coupling agent include 3-acryloxypropyltrimethoxysilane.

  As amino-based silane coupling agents, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-amino Propyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltri An example is methoxysilane.

  Examples of the ureido silane coupling agent include 3-ureidopropyltriethoxysilane. Examples of the chloropropyl-based silane coupling agent include 3-chloropropyltrimethoxysilane. Examples of mercapto-based silane coupling agents include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethinesilane. Examples of the sulfide-based silane coupling agent include bis (triethoxysilylpropyl) tetrasulfide. Examples of the isocyanate-based silane coupling agent include 3-isocyanatopropyltriethoxysilane. Examples of the aluminum coupling agent include acetoalkoxyaluminum diisopropylate.

  The ratio of the dispersant to the raw material powder (nanoparticles) can be 0.01 to 10.0 by weight ratio. When the ratio of the dispersant to the raw material powder is less than 0.01 by weight, the dispersant is insufficient and the dispersion of the nanoparticles becomes insufficient. On the other hand, when the ratio of the dispersant to the raw material powder exceeds 10.0 by weight, the particles tend to aggregate. The weight ratio of the dispersant to the raw material powder is preferably 0.5 to 3.0.

  The operating conditions of the bead mill in the method for producing a nanoparticle dispersion of the present invention are as follows. The stirring particles are preferably stirring particles having a particle diameter of 1 to 50 μm. When the particle diameter is smaller than 1 μm, the impact force against the raw material powder is small, and it takes time for dispersion. On the other hand, when the particle diameter of the stirring particles exceeds 50 μm, the impact force against the raw material powder becomes too large, the surface energy of the dispersed particles increases, and reaggregation tends to occur. Further, it is desirable to use the agitated particles that have been sufficiently polished. When stirring particles that are not sufficiently polished are used, the light transmittance of the dispersion liquid is lowered, although there is almost no influence on the pulverization and dispersion of the particles. Examples of the stirring particles applicable to the present invention include zirconia, alumina, silica, glass, silicon carbide, and silicon nitride.

  In order to disperse the raw material powder in the dispersion medium, it is preferable to stir the peripheral speed of the bead mill rotor at a speed of 3 to 17 m / s. If the peripheral speed of the bead mill rotor is less than 3 m / s, the impact force on the raw material powder is small, and dispersion takes time. On the other hand, if the peripheral speed of the rotor of the bead mill exceeds 17 m / s, the impact force on the raw material powder becomes too large, the surface energy of the dispersed particles increases, and reaggregation tends to occur.

  When the aggregated nanoparticles are dispersed in the primary particles by the above method, it is possible to stabilize the dispersion by performing a surface modification in which a dispersion medium is combined with a dispersant on the nanoparticle surface. In other words, when polymer precursors such as monomers, dimers, trimers, and oligomers are used as the dispersion medium, they are pre-added with a polymerization inhibitor and bonded to the nanoparticle surface even though no polymerization initiator is added. The dispersant reacts with the monomer. This reaction is carried out mechanochemically by stirring particles, that is, microbeads. Since the collision / shear energy of the stirring particles is not large, when the reaction on the nanoparticle surface proceeds to some extent, the reaction between the dispersing agent bonded to the nanoparticle surface and the monomer stops. During this time, the dispersants, which are surface modifiers, also polymerize between the nanoparticles and cause aggregation, but the aggregates are dispersed by the long-time collision / shearing action of the stirring particles. In this way, a part of the dispersion medium reacts with the nanoparticles, so that even when the nanoparticles are in close proximity, the affinity with the dispersion medium is maintained, so that a stable nanoparticle dispersion is produced. Can do.

  At this time, depending on the surface properties of the nanoparticles, such as oxides with strong agglomeration properties, nanoparticle reagglomerates formed by the formation of strong bonds by the polymerization reaction between the nanoparticle surface and monomers, dimers, trimers, and oligomers It was found that there was a case where re-dispersion could not be achieved even by performing bead mill dispersion for a long time. In general, it is known that silicon dioxide nanoparticles are difficult to form and stably disperse as seen in many dispersion systems. It is considered that structure formation is likely to occur even in a dispersion medium containing monomers and oligomers. As a result of repeated experiments and examinations, in the case of such nanoparticles, a bead mill is prepared by sufficiently adding a polymerization inhibitor that inhibits the polymerization reaction of monomers and oligomers into a dispersion medium containing monomers and oligomers in advance. It was found that the nanoparticles can be sufficiently dispersed by suppressing the start of the polymerization reaction of monomers and oligomers on the surface of the nanoparticles during dispersion and dispersing the nanoparticles. On the other hand, even silicon dioxide nanoparticles can be dispersed in a monomer or the like without adding a polymerization inhibitor in the case of silicon dioxide nanoparticles with weak cohesion.

In the case of silicon dioxide in which the nanoparticles have strong cohesiveness, the addition amount of the polymerization inhibitor is 2 × 10 ⁻⁴ to 1 × 10 ⁻² mol per 1 g of silicon dioxide corresponding to the total surface area of silicon dioxide. The amount is preferably 3 × 10 ⁻⁴ to 2 × 10 ⁻³ mol based on 1 g of silicon dioxide, and more preferably 4 × 10 ⁻⁴ to 1 × 10 ⁻³ mol based on 1 g of silicon dioxide. By setting the addition amount of the polymerization inhibitor within this range, silicon dioxide can be sufficiently dispersed in the dispersion medium. Here, the reason why the addition amount of the polymerization inhibitor is defined as corresponding to the total surface area of silicon dioxide is as follows. The amount of the polymerization inhibitor added is determined based on the total amount of the surface area of the silicon dioxide nanoparticles to be dispersed, and the concentration of the polymerization inhibitor added to the monomer, oligomer, etc. This is because the diameter and the dispersion concentration are not constant and are difficult to limit. This is because the monomers and oligomers that polymerize during the bead mill operation are polymerized by mechanochemical action only on the surface of the silicon dioxide nanoparticles. The total surface area of the silicon dioxide nanoparticles is determined by the size of the silicon dioxide nanoparticles and the total weight dispersed in the monomer or oligomer. In the case of the examples described later, the primary particle diameter of the silicon dioxide nanoparticles is 12 nm, and when the methyl methacrylate molecules adhere to the silicon dioxide nanoparticle surface, assuming that the cross-sectional area occupied by the molecules is 50 mm, 950 ppm That is, the monolayer coating is performed at a concentration of about 8 × 10 ⁻⁴ mol per 1 g of silicon dioxide nanoparticles. By adding a polymerization inhibitor corresponding to the amount, the polymerization reaction of methyl methacrylate on the surface of the silicon dioxide nanoparticles can be almost completely suppressed in calculation.

  As a polymerization inhibitor, for vinyl monomers such as methyl methacrylate and dimers, trimers and oligomers thereof, for nitrosamines, N-nitrosophenylhydroxyamine, N-nitrosophenylhydroxyamine aluminum salt, and hydroxy Examples of the quinone type include hydroxyquinone and 2,5-bis (1,1,3,3 tetramethylbutyl) hydroquinone.

  The method for producing a nanoparticle dispersion liquid of the present invention can be efficiently produced in a short time using the nanoparticle dispersion liquid production apparatus 1 shown in FIG. FIG. 1 is a diagram showing a schematic configuration of a nanoparticle dispersion production apparatus 1 as an embodiment of the present invention. The nanoparticle dispersion manufacturing apparatus 1 is a flow-through nanoparticle dispersion manufacturing apparatus 1, and adjusts a bead mill 2 that is a dispersing machine, a raw material slurry supply pump 3 that supplies the raw material slurry to the bead mill 2, and a raw material slurry. A raw material slurry tank 4, a particle size distribution measuring device 5 for measuring the particle size of particles in the dispersion, and a data processing device 6 for processing the particle size data measured by the particle size distribution measuring device 5 are mainly configured.

The bead mill 2 includes a stator 12 having a cooling jacket 11 attached thereto, a centrifugal separation type bead separator 13 at an upper portion thereof, and a rotor 15 having a rotor pin 14 coaxially disposed at the lower portion thereof, and a rotor. And a motor 7 for driving the motor 15. The rotor 15 and the stator 12 are sealed by a shaft seal 16 to seal the inside of the machine. The bead mill 2 may be of a type in which the rotor pin 14 and the bead separator 13 are independently driven, or a type in which the bead separator is used for both bead separation and bead stirring. The shape of the bead mill 2 is not particularly limited, but the shape shown in Table 1 can be preferably used. Table 1 shows the length of each part with the stator inner diameter being 1.0. In Table 1, type A is a bead mill in which the rotor pin and the bead mill separator are coaxially mounted, type B is a bead mill in which the rotor pin and the bead mill separator are driven independently, and type C is a bead separator in which the bead separator is separated. This type of bead mill is also used for bead stirring.

  The raw material slurry tank 4 includes a stirrer 18, and the raw material slurry supply pump 3 quantitatively supplies the raw material slurry (dispersion) to the bead mill 2. The raw material slurry supplied to the bead mill 2 collides with the stirring particles in the stator 12, and the aggregated raw material powder is dispersed. The raw material slurry from which the stirring particles are separated by the bead separator 13 returns to the raw material slurry tank 4 through the return line 19.

  The above configuration is similar to the configuration of a conventional distribution-type nanoparticle dispersion production apparatus. The nanoparticle dispersion production apparatus 1 shown in the present embodiment is provided with a particle size distribution measurement device 5 that is provided with a branch in the return line 19 of the raw material slurry and that can measure the particle size of the particles in the raw material slurry (dispersion). There is a feature. Thereby, the particle diameter in a raw material slurry can be measured continuously or intermittently. Furthermore, in this embodiment, since the data processing device 6 that processes the particle size data measured by the particle size distribution measuring device 5 is provided, desired data can be output.

  In order to disperse the agglomerated particles in the dispersion medium, it has already been necessary to use a bead mill capable of separating fine stirring particles to cause the stirring particles of a predetermined size to collide with the raw material powder at a predetermined speed. As stated. Although it is possible to obtain a dispersion in which fine nanoparticles are dispersed by operating an appropriate bead mill under appropriate operating conditions, in order to obtain a nanoparticle dispersion with good dispersibility efficiently, When a polymer precursor such as re-agglomeration or monomer is used as a dispersion medium, it is necessary to pay attention to the aggregation of particles accompanying the reaction of the dispersion medium.

  As can be seen from Example 4 to be described later, the average particle diameter of the particles in the dispersion generally decreases with time. The reduction rate of the average particle size is relatively large when the particle size is large, and decreases as the average particle size approaches the primary particle size of the particles. Further, as can be seen from Example 3 described later, when the dispersion operation is continued even after the average particle diameter of the dispersed particles, in particular, the 90% passing particle diameter is substantially the same as the primary particle diameter of the particles, On the contrary, the average particle diameter and the 90% passing particle diameter increase. This is presumably due to the reaggregation of the dispersed particles or the aggregation of the dispersed particles accompanying the monomer reaction. From these, it can be seen that in order to obtain a fine nanoparticle dispersion, it is not necessary to simply increase the dispersion operation time, but it is important to complete the dispersion operation at an appropriate time. However, the optimum dispersion time varies depending on the properties and size of the target raw material powder, the type of dispersion medium, the type and concentration of the dispersant, the target dispersed particle size, the bead mill operating conditions, etc. It is not easy to grasp the dispersion time. In addition, when a substance that easily reacts, such as a monomer, is used as the dispersion medium, the dispersion particles are agglomerated due to the reaction of the monomer, so that the influence of the dispersion time on the average particle size is large.

  Unlike the conventional dispersion apparatus, the nanoparticle dispersion liquid production apparatus 1 shown in the present embodiment includes the particle size distribution measurement apparatus 5 that can measure the particle diameter of the particles in the raw slurry (dispersion liquid). The particle diameter in the raw slurry (dispersion) can be measured intermittently. By measuring the particle size in the raw material slurry (dispersion liquid) continuously or intermittently, it becomes possible to grasp the movement of the particle size of the dispersed particles, and the dispersion operation is performed before the dispersed particles re-aggregate. Can be terminated. Thereby, a dispersion liquid in which fine particles are dispersed can be obtained within a short time. When the average particle size of the particles in the dispersion approaches the primary particle size, the value of the average particle size hardly changes, but the 90% passing particle size changes relatively greatly, so the 90% passing particle size is dispersed. It can be suitably used for determining the end point of.

  Moreover, since the nanoparticle dispersion liquid manufacturing apparatus 1 is equipped with the data processing apparatus 6 which processes the particle diameter data measured with the particle size distribution measuring apparatus 5, using this, the average particle diameter of a dispersed particle and 90% passage particle diameter are used. The rate of decrease can be calculated. Thereby, for example, the nanoparticle dispersion can be efficiently produced by ending the dispersion operation when the average particle diameter of the dispersed particles or the decrease rate of the 90% passing particle diameter reaches a predetermined value. it can. It is inevitable that the average particle diameter and the 90% passing particle diameter of the dispersed particles will vary due to particle aggregation, measurement accuracy of the particle size distribution measuring device 5, and the like. Therefore, if the end point of the dispersion operation is when the average particle diameter of dispersed particles or the 90% passing particle diameter reaches a predetermined value, there may be cases where desired dispersed particles cannot be obtained due to data variation. By calculating the decrease rate of the average particle diameter or 90% passing particle diameter and determining the end point of the dispersion operation from this value, it is possible to prevent quality variations due to data variations. A computer can be used for the data processing device 6, and predetermined data can be easily obtained by programming and installing a calculation procedure in advance.

  In the present embodiment, the method of measuring the particle diameter of the dispersed particles in the raw slurry (dispersion liquid) online and determining the end point of the dispersion operation is shown online, but the value measured to determine the end point of the dispersion operation is It is not limited to the particle size. In general, the light transmittance of a dispersion in which particles are dispersed in a dispersion medium varies greatly depending on the particle diameter of the dispersed particles. By grasping the relationship between the particle diameter of the particles in the dispersion and the light transmittance of the dispersion in advance, the light transmittance of the dispersion can be measured, and the end point of the dispersion operation can be determined based on this. Furthermore, since the viscosity of the dispersion varies depending on the dispersion state of the particles, the relationship between the particle diameter of the particles in the dispersion and the viscosity of the dispersion can be measured in advance, and the end point of the dispersion operation can be determined based on the viscosity of the dispersion. it can.

  Similarly, when the particle size of the dispersed particles in the dispersion liquid or the viscosity of the dispersion liquid changes, the driving power of the rotor of the bead mill also changes, so the current or power of the driving motor 7 is measured with an ammeter or wattmeter, The end point of the dispersion operation can also be determined from this value. Further, since the stirring power can be calculated by multiplying the stirring torque and the rotation speed, the stirring torque may be measured. In addition, the physical property value or physical quantity of the dispersion liquid having a predetermined relationship with the average particle diameter of the dispersed particles in the dispersion liquid may be measured, and the end point of the dispersion operation may be determined based on this. It is desirable that the physical property values and physical quantities of the dispersion liquid have large changes from the viewpoint of accuracy. Furthermore, it is more preferable if these values can be measured easily and in a short time. In the above embodiment, a flow-through nanoparticle dispersion production apparatus is shown, but a batch-type nanoparticle dispersion production apparatus may be used. Furthermore, the measurement of the average particle size is not necessarily online.

  A nanoparticle dispersion in which nanoparticles having a polymer precursor such as a monomer or an oligomer as a dispersion medium are uniformly dispersed can be polymerized using a known method such as raising the temperature to obtain a nanocomposite material. Nanocomposite materials in which nanoparticles are uniformly dispersed often exhibit superior properties compared to polymers that do not contain nanoparticles. For example, a nanocomposite material in which titanium oxide is uniformly dispersed in polymethyl methacrylate is transparent and has an ability to absorb ultraviolet rays. Therefore, if a container is manufactured with this, ultraviolet rays are conventionally cut by aluminum foil or aluminum vapor deposition. In place of the container, the contents can be visually confirmed, and the container can be made to have ultraviolet rays cut. Of course, the nanoparticle dispersion can be coated on a transparent container and then polymerized to form a container coated with the nanocomposite material. Furthermore, a transparent film can be manufactured with a nanocomposite material and used. In addition, the nanocomposite material in which the nanoparticles are uniformly dispersed has increased flame resistance and heat resistance. Furthermore, the nanocomposite material of the present invention can be used as a material excellent in solvent resistance and gas barrier properties.

  Uses other than containers and transparent films can be used as materials for automobiles, cosmetics, optical materials, and the like. As a material for automobiles, it can be used for window glass substitutes, headlight covers, etc., taking advantage of its strong mechanical strength, transparency, excellent solvent resistance, light weight, and excellent heat resistance. it can. Further, it can be used as a sunroof material by taking advantage of the ultraviolet blocking property of titanium oxide. It can also be used as a finish paint that is resistant to scratches. Cosmetics can be used as resin spheres instead of glass spheres, taking advantage of UV blocking properties, transparency and solvent resistance. In addition, as an optical material, it can be used as a lens having a high mechanical strength, transparent, a high refractive index or a low refractive index characteristic, a lens replacing glass, and a display having an antireflection film function.

Example 1
The experiment was performed as follows. As the disperser, a bead mill (UAM-02 manufactured by Kotobuki Industries Co., Ltd.) having an internal volume of 0.2 L developed by us was used. A basic configuration of the experimental apparatus 20 is shown in FIG. The basic configuration of the experimental apparatus 20 is the same as that of the nanoparticle dispersion production apparatus 1 shown in FIG. 1, but the particle size distribution measurement apparatus 5 that can measure the particle diameter of the particles in the raw slurry (dispersion) online. The particle size of the particles in the raw slurry (dispersion) was not measured and was measured off-line. The same members as those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted. The raw slurry tank 4 includes a jacket (not shown) for cooling. As the stirring particles, spherical zirconia particles having a particle diameter of 0.03 mm were used, and the amount charged into the bead mill was 0.5 kg (about 0.13 L). The peripheral speed of the rotor was 8 m / s.

  The experiment was performed as follows. Titanium oxide powder (NTK90 manufactured by Nippon Aerosil Co., Ltd.) is used as a raw material powder, methyl methacrylate is used as a dispersion medium, 4.0 g of raw material powder, 186 g of a dispersion medium, and 14.0 g of a dispersant are charged into the raw material slurry tank 4, The raw material slurry was adjusted by stirring and mixing. In the bead mill 2, 210 g of a dispersion medium was put in advance, the raw material slurry was supplied to the bead mill 2 at a rate of 10 kg / h by the raw material slurry supply pump 3, the raw material powder was dispersed in the bead mill 2, and passed through the bead mill. The slurry solution was returned to the raw slurry tank 4 through the return line 19. This circulation operation was performed for 150 minutes. The solid content concentration (the raw material powder concentration in the dispersion medium) is 1.0% by weight. The weight ratio of the dispersant to the raw material powder is 3.5. In the middle, the dispersion was sampled over time, and the particle size distribution of the dispersed particles was measured. NTK90 manufactured by Nippon Aerosil has a primary particle diameter of 10 nm and has been subjected to alkylsilane surface treatment. Organosilane (manufactured by Shin-Etsu Chemical: KBM-5103) was used as the dispersant. Moreover, Nikkiso Co., Ltd. Microtrac UPA150 and Otsuka Electronics Co., Ltd. FPAR-1000 were used for the particle size distribution measuring apparatus.

  As a result of the experiment, the average particle diameter of the dispersed particles in the dispersion decreased with the dispersion time, the average particle diameter (median diameter) after the dispersion operation was 19.8 nm, and the 90% passing particle diameter was 33.0 nm. there were. When the dispersion was visually observed, the transparency increased with time, and it became completely transparent after 150 minutes. The dispersion after the dispersion time of 105 minutes was transparent after standing for one day and no precipitation of particles was observed.

Example 2
The experimental apparatus is the same as in Example 1. The operating conditions of the dispersing machine are the same as those in the first embodiment. Experimental conditions such as raw materials used are basically the same as those in Example 1. The amount of the added dispersant is 12.0 g, and the weight ratio of the dispersant to the raw material powder is 3.0. Further, the dispersion time was 180 minutes.

  As a result of the experiment, the average particle diameter (median diameter) after the dispersion operation was 11.5 nm, and the 90% passing particle diameter was 18.6 nm. The particle size distribution was also sharp as shown in FIG. When the dispersion was visually observed, the transparency increased with time, and it became completely transparent after 150 minutes. The dispersion having a dispersion time of 90 minutes or more was transparent after standing for one day and no precipitation of particles was observed.

Example 3
The configuration of the experimental apparatus is the same as the configuration shown in FIG. The operating conditions of the disperser are the same as in Example 1 except that the amount of the stirred particles charged into the bead mill is 0.4 kg (about 0.108 L). The experimental conditions such as the raw materials used were the same as in Example 1 except that the weight ratio of the dispersant to the raw material powder was 2.0 and the dispersion time was 360 minutes.

  As a result of the experiment, the average particle diameter of the dispersed particles in the dispersion decreased with the dispersion time, and the average particle diameter (median diameter) and 90% passing particle diameter showed the minimum value at the time of dispersion operation 300 minutes. At this time, the average particle diameter (median diameter) was 11.8 nm, and the 90% passing particle diameter was 15.2 nm. Thereafter, the average particle diameter (median diameter) and the 90% passing particle diameter increase with the dispersion operation time, and the average particle diameter at the end of the dispersion operation (dispersion time 360 minutes) is 16.0 nm and the 90% passing particle diameter is It was 61.0 nm. When the dispersion was visually observed, the transparency increased with time and became transparent after 180 minutes. The dispersion after the dispersion time of 180 minutes was transparent after standing for one day and no precipitation of particles was observed. Hereinafter, the minimum particle size in the dispersion process is referred to as the ultimate particle size.

Example 4
Other conditions are the same as in Example 3 except that the weight ratio of the dispersant to the raw material powder is 3.0 and the dispersion time is 240 minutes.

Table 2 shows the average particle diameter of the dispersed particles in the dispersion and the ratio of the 90% passing particle diameter to the primary particle diameter. Both the average particle diameter (median diameter) and 90% passing particle diameter decreased with the lapse of dispersion time. For both the average particle size and 90% passing particles, the decrease rate decreased as the particle size decreased. The average particle size was about 1.3 times the primary particle size at a dispersion time of 120 minutes, 1.0 times at a dispersion time of 240 minutes, and the rate of decrease in the particle size after the dispersion time of 120 minutes was small. On the other hand, the 90% passing particle size is about 7.4 times the primary particle size at a dispersion time of 120 minutes, and about 1.3 times at a dispersion time of 240 minutes, and the reduction rate is large compared to the average particle size. It was.

  When the particle size with a dispersion time of 240 minutes is compared with the results of Example 3, in Example 3, the average particle size (median diameter) is 12.1 nm and the 90% passing particle size is 44.1 nm. In No. 4, the average particle diameter (median diameter) was 10.0 nm, the 90% passing particle diameter was 12.6 nm, and the particle diameter was small. When the dispersion was visually observed, the transparency increased with time and became transparent after 150 minutes. The dispersion after the dispersion time of 150 minutes was transparent even after standing for one day, and no precipitation of particles was observed.

Example 5
The other conditions are the same as in Example 3 except that the solid content concentration is 5% by weight and the final dispersion time is 660 minutes.

  As a result of the experiment, the average particle diameter (median diameter) after completion of the dispersion operation was 15.7 nm, and the particle diameter when passing through 90% by weight was 26.8 nm. The average particle diameter (median diameter) at the time of the dispersion operation of 540 minutes was 10.2 nm, and the average particle diameter became large after the dispersion time of 540 minutes. When the dispersion was visually observed, the transparency increased with time and became transparent after 240 minutes.

Example 6
As the raw material powder, titanium oxide (MT150A, no surface treatment) manufactured by Teika was used. The final dispersion time was 240 minutes. Other conditions are the same as those in Example 3. Here, the light transmittance of the dispersion was also measured. The light transmittance was measured using U-2810 manufactured by Hitachi Technologies, Ltd.

  As a result of the experiment, the particle diameter decreased with the lapse of the dispersion time, the average particle diameter (median diameter) after completion of the dispersion operation was 12.5 nm, and the particle diameter when passing through 90% by weight was 20.1 nm. When the dispersion was visually observed, the transparency increased with time and became transparent after 120 minutes. In addition, the dispersion after the dispersion time of 120 minutes was transparent after standing for one day, and no precipitation of particles was observed. FIG. 4 shows the measurement results of light transmittance. The light transmittance absorbed the ultraviolet region (up to 380 nm), and the visible light region (from 380 nm) transmitted through the dispersion time. That is, the transparency was increased and the ultraviolet rays could be selectively absorbed.

Examples 7-10
In order to investigate the influence of the added amount of the dispersion medium, an experiment was conducted as follows. The bead mill and the experimental apparatus 20 are the same as those of the third embodiment, and the basic experimental procedure is the same as that of the third embodiment although the dispersion time is different. The amount of the dispersant added was 1.0, 0.5, 0.1, and 0.01 in terms of weight ratio to the raw material powder.

  As a result of the experiment, the reached particle diameter D50 is 1.0 and 0.01 in terms of the weight ratio of the dispersant to the raw material powder, 11.5 nm and 12.5 nm, respectively, and the addition ratio of the dispersant to the raw material powder It became substantially the same size in the range of 0.01 to 1.0 (weight ratio). This value was substantially the same as the value of the reached particle diameter D50 of Example 3 and Example 4 in which the addition ratio (weight ratio) of the dispersant to the raw material powder was 2.0, 3.0. Further, the value of the reached particle diameter D90 was also in the range of 18.7 to 19.9 nm, and the influence of the added amount of the dispersant was not observed. On the other hand, the time to reach the ultimate particle size was longer as the amount of dispersant added was smaller. The time required to reach the reached particle diameter is about twice as long as the addition ratio (weight ratio) of the dispersant to the raw material powder is 0.01 when the addition ratio (weight ratio) is 2.0. Cost.

Examples 11-14
In order to investigate the influence of the solid content concentration, an experiment was conducted as follows. The bead mill and the experimental apparatus 20 are the same as those of the third embodiment, and the basic experimental procedure is the same as that of the third embodiment although the dispersion time is different. The solid content concentration was four types of 10.0, 20.0, 30.0, and 40.0% by weight. In addition, the addition ratio with respect to the raw material powder of a dispersing agent was 1.0 by weight ratio.

  As a result of the experiment, the reached particle diameter D50 was 13.5 nm and 12.8 nm at a solid content concentration of 10% by weight and 40% by weight, respectively, and was almost the same in the range of the solid content concentration of 10 to 40% by weight. Further, the value of the reached particle diameter D90 was also in the range of 20.1 to 22.5, and the influence of the solid content concentration was not observed. On the other hand, the time to reach the ultimate particle size was 700 minutes and 1700 minutes, respectively, at a solid content concentration of 10% by weight and 40% by weight, and became longer as the solid content concentration was higher.

Comparative Example 1
Other conditions were the same as those in Example 2 except that the dispersant was not added. As a result of the experiment, the reached particle diameter was 358.3 nm as an average particle diameter (median diameter) and 644.3 nm as a 90% passing particle diameter. As a result of visual observation, the dispersion was cloudy and the particles were not dispersed.

Comparative Example 2
Other conditions are the same as those in Example 3 except that the amount of the dispersant added to the raw material powder is 0.003 by weight and the dispersion time is 180 minutes. As a result of the experiment, the reached particle diameter was 164.1 nm as an average particle diameter (median diameter) and 272.7 nm as a 90% passing particle diameter. As a result of visual observation, the dispersion was cloudy and the particles were not dispersed.

Comparative Example 3
The other conditions are the same as in Example 3 except that the addition ratio of the dispersant to the raw material powder is 0.005 by weight and the dispersion time is 180 minutes. As a result of the experiment, the average particle diameter (median diameter) was 139.0 nm, and the 90% passing particle diameter was 308.9 nm. As a result of visual observation, the dispersion was cloudy and the particles were not dispersed.

Table 3 shows the experimental conditions and results of Examples 1 to 14 and Comparative Examples 1 to 3.

Examples 15 to 23
In order to investigate the influence of the size of the stirring particles and the peripheral speed of the rotor, an experiment was conducted as follows. The bead mill and the experimental apparatus 20 are the same as those in the first embodiment, and the basic experimental procedure is the same as that in the first embodiment. As the stirring particles, spherical zirconia particles having a particle diameter of 0.015, 0.03, and 0.05 mm were used, and the amount charged into the bead mill was 0.5 kg (about 0.13 L). The rotor has three peripheral speeds of 8, 10, and 12 m / s. Titanium oxide powder (MT100-AQ manufactured by Teika Co., Ltd .: primary particle size 15 nm) was used as the raw material powder, methyl methacrylate was used as the dispersion medium, and the solid content concentration was 1% by weight. As the dispersant, organosilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-5103) was used, and the amount of the dispersant added to the raw material powder was 1.0 by weight.

The results are shown in Table 4 and FIG. Table 4 and FIG. 5 also show the results of Comparative Examples 4 to 9 described later. The reached particle diameter D50 was smaller as the rotor peripheral speed was lower, and the dispersion time was longer and smaller as the stirring particle diameter was smaller. The rotor peripheral speed was 8 m / s, the stirring particle diameter was 0.015 mm, and the ultimate particle diameter was 14.7 nm.

Comparative Examples 4-9
The conditions are the same as those of Examples 15 to 23 except that the size of the stirring particles is 0.1 mm and 0.3 mm. When stirring particles of 0.1 mm were used, the ultimate particle diameter was 58.4 nm even when the rotor peripheral speed was 8 m / s. When 0.3 mm of stirring particles was used, the ultimate particle diameter was 147.4 nm even when the rotor peripheral speed was 8 m / s.

Example 24
Silica was used as the raw material powder, and the experiment was conducted as follows. The experimental apparatus, the operating conditions of the disperser, etc. are basically the same as in Example 3. As stirring particles, spherical zirconia particles having a particle diameter of 0.015 mm were used, the rotor peripheral speed was 12 m / s, and the slurry circulation rate was 13 kg / h. As the raw material powder, RX300 manufactured by Nippon Aerosil Co., Ltd., hexamethyldisilazane treatment, powdered silicon dioxide nanoparticles with a primary particle diameter of 7 nm were used. Methyl methacrylate was used as the dispersion medium, and the solid content concentration was 4.0% by weight. Organosilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-5103) was used as the dispersant, and the weight ratio of the dispersant to the raw material powder was 2.0.

  As a result of the experiment, the particle diameter became smaller with the dispersion treatment time. At the dispersion time of 660 minutes, the reached particle diameter D50 was 33.6 nm, and the reached particle diameter D90 was 53.9 nm. FIG. 6 shows the particle size distribution measurement results. FIG. 7 shows the result of measuring the light transmittance of the dispersion with a dispersion time of 660 minutes using a spectrophotometer.

Comparative Example 10
The experiment was performed under the same conditions as in Example 24 except that no dispersant was added. As a result of the experiment, the particles were not dispersed even when the dispersion treatment was performed for 900 minutes, the reaching particle diameter D50 was 135405 nm, and the reaching particle diameter D90 was 383229 nm.

Example 25 to Example 37
The dispersion experiment of the highly cohesive nanoparticles was performed as follows. The operating conditions of the experimental apparatus and the disperser are basically the same as in Example 3, except that a polymerization inhibitor is further added to the methyl methacrylate solution to which the dispersant has been added in the slurry preparation stage. As the raw material powder, R7200 manufactured by Nippon Aerosil Co., Ltd. and powdered silicon dioxide nanoparticles with a primary particle size of 12 nm were used. This raw material powder is a highly cohesive powder particle whose surface is treated with methacrylosilane having an affinity for methyl methacrylate. Methyl methacrylate was used as the dispersion medium, and the solid content concentration was 2.0% by weight. Organosilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-5103) was used as the dispersant, and the weight ratio of the dispersant to the raw material powder was 2.0. In addition, hydroquinone (special grade reagent manufactured by Kanto Chemical Co., Inc.) was used as a polymerization inhibitor added to methyl methacrylate. Its molecular weight is 110. Hydroquinone was added at 250 ppm to 2000 ppm with respect to methyl methacrylate. That is, it is an amount corresponding to 2.2 × 10 ⁻⁴ mol to 1.8 × 10 ⁻³ mol for 1 g of silicon dioxide nanoparticles. The amount of polymerization inhibitor added here does not include the amount of several ppm of polymerization inhibitor originally contained in the reagent, but refers to the amount of newly added polymerization inhibitor. As the stirring particles, spherical zirconia particles having a particle diameter of 0.015 mm and 0.03 mm were used, and the rotor peripheral speed was 6 m / s and 8 m / s.

Comparative Examples 11-13
The addition amount of the polymerization inhibitor was changed from 0 ppm to 125 ppm with respect to methyl methacrylate. That is, the amount corresponds to 0 mol to 1.1 × 10 ⁻⁴ mol for 1 g of silicon dioxide nanoparticles. Further, in the case where 100 μm stirring particles were used, the addition amount of the polymerization inhibitor was 1000 ppm with respect to methyl methacrylate. As stirring particles, zirconia particles having a particle diameter of 15 μm and 30 μm and 100 μm were used, and the rotor peripheral speed was 6 m / s, 8 m / s, and 10 m / s. The other conditions are the same as those in Example 25 to Example 37. The amount of polymerization inhibitor added here does not include the amount of several ppm of polymerization inhibitor originally contained in the reagent, but refers to the amount of newly added polymerization inhibitor.

The results are shown in Table 5. As a result of the experiment, it was necessary to add hydroquinone, which is a polymerization inhibitor, to methyl methacrylate, as a dispersion condition for dispersing silicon dioxide nanoparticles, using stirring particles having a particle diameter of 15 μm, and a rotor peripheral speed of 6 m / s and Under the condition of 8 m / s, it was necessary to add 250 ppm or more of the polymerization inhibitor with respect to methyl methacrylate. In addition, when stirring particles having a particle diameter of 30 μm are used and the rotor peripheral speed is 6 m / s and 8 m / s, the addition amount of the polymerization inhibitor is 250 ppm or more, preferably 375 ppm or more with respect to methyl methacrylate. It was. Under these conditions, the ultimate particle diameter was 26 to 87 nm, and sufficiently dispersed nanoparticles were obtained. On the other hand, when the polymerization inhibitor was 0 to 125 ppm relative to methyl methacrylate, the reached particle diameter was 836 to 1093 nm. Furthermore, when the particle diameter of the stirring particles is 100 μm and the rotor peripheral speed is 10 m / s, even if the polymerization inhibitor is 1000 pm with respect to methyl methacrylate and the polymerization inhibitor is sufficiently present, the reached particle diameter is about It was 992 nm, and the dispersion of the nanoparticles was insufficient.

Example 38
The experiment was conducted in the following manner by changing the type of the dispersant. The experimental apparatus, the operating conditions of the disperser, etc. are basically the same as in Example 3. Titanium oxide powder (MT150A manufactured by Taika: primary particle diameter 15 nm) was used as the raw material powder, methyl methacrylate was used as the dispersion medium, and the solid content concentration was 1.0% by weight. As the dispersant, 3-methacryloxypropyltrimethoxysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) was used, and the weight ratio of the dispersant to the raw material powder was 2.0.

  As a result of the experiment, the particle size was able to be dispersed to a nano size with a dispersion time of 120 minutes, and became the minimum with a dispersion time of 180 minutes. The ultimate particle size D50 was 11.7 nm, and the ultimate particle size D90 was 13.9 nm. When the dispersion was visually observed, the transparency increased with the lapse of the dispersion time, and it became completely transparent in 120 minutes. The dispersion after the dispersion time of 120 minutes was transparent after standing for one day, and no precipitation of particles was observed.

Example 39
The other experimental conditions were the same as in Example 38, except that methyltrimethoxysilane (KBM-13 manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the dispersant. As a result of the experiment, the particle size was a dispersion time of 300 minutes, the ultimate particle size D50 was 10.8 nm, and the ultimate particle size D90 was 16.2 nm. When the dispersion was visually observed, the transparency increased with the lapse of the dispersion time, and it became completely transparent after 300 minutes. The dispersion after the dispersion time of 300 minutes was transparent even after standing for one day, and no precipitation of particles was observed.

Example 40
Other experimental conditions were the same as in Example 38, except that hexyltrimethoxysilane (KBM-3063 manufactured by Shin-Etsu Chemical) was used as the dispersant. As a result of the experiment, the particle size was a dispersion time of 360 minutes, the ultimate particle size D50 was 10.8 nm, and the ultimate particle size D90 was 16.3 nm. When the dispersion was visually observed, the transparency increased with the lapse of the dispersion time, and it became completely transparent at 360 minutes. The dispersion after the dispersion time of 360 minutes was transparent even after standing for one day, and no precipitation of particles was observed.

Example 41
Other experimental conditions were the same as in Example 38, except that dimethyldimethoxysilane (KBE-22 manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the dispersant. As a result of the experiment, the particle diameter was a dispersion time of 300 minutes, the ultimate particle diameter D50 was 11.0 nm, and the ultimate particle diameter D90 was 15.8 nm. When the dispersion was visually observed, the transparency increased with the lapse of the dispersion time, and it became completely transparent after 300 minutes. The dispersion after the dispersion time of 300 minutes was transparent even after standing for one day, and no precipitation of particles was observed.

The results of Example 38 to Example 41 are shown in Table 6.

Example 42
Styrene monomer was used as a dispersion medium. The experimental apparatus and dispersion conditions are the same as in Example 38. Titanium oxide powder (Taika MT150A: primary particle size 15 nm) was used as the raw material powder, and the solid content concentration was 1.0% by weight. As the dispersant, KBM-1403 made by Shin-Etsu Chemical, which is a styrene coupling agent, was used, and the weight ratio of the dispersant to the raw material powder was 2.0. As a result of the experiment, the particle size was a dispersion time of 240 minutes, the ultimate particle size D50 was 9.8 nm, and the ultimate particle size D90 was 13.0 nm. The measurement results of the particle size distribution are shown in FIG. When the dispersion was visually observed, the transparency increased with the lapse of the dispersion time, and the transparency was observed from 120 minutes, and became clearer in 240 minutes. The dispersion after 120 minutes was transparent even after being left for a day. FIG. 9 shows the result of measuring the light transmittance of the dispersion with a dispersion time of 240 minutes using a spectrophotometer. Due to the effect of titanium oxide, the transmittance in the ultraviolet region became zero.

Example 43
The nanocomposite material was manufactured as follows. The dispersion liquid of Example 2 with a dispersion time of 180 minutes was used. The solid content concentration in the dispersion at this time was 1% by weight, and the average particle size (median size) was 11.5 nm. 0.1 wt% of azobisisobutyronitrile (AIBN, Otsuka Chemical Co., Ltd.), which is a polymerization initiator, was added to this dispersion and mixed uniformly. This sample was charged into a disposable cup (material PP). The depth of the liquid at this time was about 3 mm. After fully replacing the inside of the vacuum dryer with nitrogen gas, place the disposable cup containing the sample in the vacuum dryer, and supply the nitrogen gas to the vacuum dryer while the sample is at a temperature of 60 ° C and a pressure of 0.01 MPa. Hold for 3 hours. After 3 hours, the sample had solidified in a transparent state. The solidified sample was placed on a printed matter on which characters of 10.5 points were printed, and when the characters were confirmed through the sample, the characters could be read very clearly.

Solvent Resistance Evaluation Test The solvent resistance of the titanium oxide / PMMA (polymethyl methacrylate) nanocomposite material was measured as follows. A PMMA polymer was produced in the same manner as a comparative example. The production conditions of the titanium oxide / PMMA nanocomposite material are as follows. Three solid content concentrations of 1% by weight, 5% by weight, and 10% by weight are used, and KBM-5103 is used as the dispersant, and the ratio of the dispersant to the raw material powder is 2.0 by weight. The method for producing the nano-dispersion and the method for producing the nanocomposite material are basically the same as in Example 38 and Example 43.

  As the solvent, acetone, methanol (MeOH), dimethylformamide (DMF), tetrahydrofuran (THF), and toluene were used. 500 mg of titanium oxide / PMMA nanocomposite material and PMMA polymer fragments were weighed and placed in a glass container containing 100 ml of each of the above five organic solvents, and left for 24 hours at room temperature in order to examine immersion by the solvent. When the debris samples were observed after the lapse of 24 hours, they were classified into those in which some were dissolved (×), those that gelled (×, Δ, or ◯), and those that hardly changed. The weight increase due to the immersion of the titanium oxide / PMMA nanocomposite material and the PMMA polymer with the solvent was determined by wiping off the solvent adhering to the sample with a paper waste generally used in chemical experiments. It was determined by examining the weight.

The results are shown in Table 7. Among the judgment symbols in Table 7, the double circle is in a good state without any change, the circle is in a partially swollen good state, the triangle is in a swollen state, and the cross is in a partially dissolved or gelled state. Show. Although the titanium oxide / PMMA nanocomposite material partially swelled, it was stable without dissolving. It was confirmed that the nanocomposite material having a titanium oxide content of 10% by weight is particularly stable. On the other hand, the PMMA polymer was unstable to organic solvents other than methanol. In the titanium oxide nanocomposite material, it is confirmed from the solvent resistance that the nanoparticle surface forms a crosslinking point by a reaction from a monomer having a monofunctional acrylic group and forms a strong three-dimensional network.

Claims (19)

A method for producing a nanoparticle dispersion for the purpose of producing a polymer composite material containing nanoparticles having a particle size of 100 nm or less and uniformly dispersing the nanoparticles directly in a reactive solvent that is a precursor of the polymer using a bead mill Because
A bead mill having a rotor, a stator, and a bead separation mechanism that separates beads as stirring particles by centrifugation is used for the bead mill, ultra-fine beads having a particle diameter of 1 to 50 μm are used for the beads, and the reactive solvent Is a dispersion medium containing one or more substances selected from the following group (A), and a dispersant for binding the dispersion medium molecules to the surface of the nanoparticles in the dispersion process is added to the bead mill. Then, the nanoparticle dispersion is characterized in that the surface modification of the nanoparticles and the aggregated nanoparticles are uniformly dispersed in the reactive solvent to the size of primary particles of 100 nm or less.
(A) Monomer, dimer, trimer, oligomer The nanoparticles are highly cohesive silicon dioxide,
Furthermore, 2 × 10 ⁻⁴ to 1 × 10 ⁻² mol of a polymerization inhibitor is added to the reactive solvent with respect to 1 g of the silicon dioxide corresponding to the total surface area of the silicon dioxide, and the reactivity is measured by the bead mill. The method for producing a nanoparticle dispersion liquid according to claim 1, wherein the nanoparticles modified with the surface modification of the nanoparticles in a solvent are uniformly dispersed to a size of primary particles of 100 nm or less.   The method for producing a nanoparticle dispersion according to claim 1, wherein the dispersant has a group having an affinity for the nanoparticles and a group having an affinity for and reacts with the dispersion medium.   The method for producing a nanoparticle dispersion according to claim 1, wherein the concentration of the nanoparticles in the dispersion medium is 0.1 to 50% by weight.   The bead separation mechanism that separates the beads that are stirring particles by the centrifugal separation has a separator, where d / D is 0.5 to 0.9, where d is the diameter of the separator and D is the inner diameter of the stator. The method for producing a nanoparticle dispersion according to claim 1.   The method for producing a nanoparticle dispersion liquid according to claim 1, wherein a weight ratio of the dispersant to the nanoparticles is 0.01 to 10.0.   Using a bead mill equipped with a rotor, a stator, and a bead separation mechanism for separating beads as stirring particles by centrifugation, nanoparticles having a primary particle size of 100 nm or less, a dispersion medium, a dispersant, and a particle size of 1 to 50 μm The stirring particles are stirred and the nanoparticles are dispersed in the dispersion medium, and the particle diameter of the particles in the dispersion, the viscosity of the dispersion, the stirring torque of the beads mill, the stirring power of the beads mill, and the light transmittance of the dispersion A method for producing a nanoparticle dispersion, wherein at least one of the values is measured over time during the dispersion operation, and the dispersion operation is terminated when it is detected that the measured value has reached a predetermined value.   The particle diameter of the particles in the dispersion, the viscosity of the dispersion, the stirring torque of the beads mill, the stirring power of the beads mill, and the light transmittance of the dispersion are measured on-line. The manufacturing method of the nanoparticle dispersion liquid of description.   The method for producing a nanoparticle dispersion liquid according to claim 7, wherein the measurement performed during the dispersion operation is a particle diameter of the particles in the dispersion liquid, and the measured value is a 90% passing particle diameter of the particles. .   The method for producing a nanoparticle dispersion liquid according to claim 7, wherein the dispersion medium contains at least one of a monomer, a dimer, a trimer, and an oligomer.   Using a bead mill equipped with a rotor, a stator, and a bead separation mechanism for separating beads as stirring particles by centrifugation, nanoparticles having a primary particle size of 100 nm or less, a dispersion medium, a dispersant, and a particle size of 1 to 50 μm The stirring particles are stirred and the nanoparticles are dispersed in the dispersion medium, and the particle diameter of the particles in the dispersion, the viscosity of the dispersion, the stirring torque of the beads mill, the stirring power of the beads mill, and the light transmittance of the dispersion Nanoparticles characterized in that at least one of the values is measured over time during the dispersion operation, and the dispersion operation is terminated when it is detected that the amount of change in the measured value per time has reached a predetermined value A method for producing a dispersion.   The method for producing a nanoparticle dispersion according to claim 11, wherein the dispersion medium contains at least one of a monomer, a dimer, a trimer, and an oligomer.   A nanoparticle dispersion produced by the method of claim 1. A bead mill including a rotor, a stator, and a bead separation mechanism for separating beads as stirring particles by centrifugation;
Stirring particles having a particle size of 1 to 50 μm;
At least one of particle size distribution measuring means, dispersion viscosity measuring means, bead mill stirring torque measuring means, bead mill stirring power measuring means, and dispersion light transmittance measuring means;
The nanoparticle dispersion liquid manufacturing apparatus characterized by including. Furthermore, a raw material adjusting device disposed outside the bead mill,
A pump connected to the raw material adjusting device and the bead mill and pumping the dispersion;
The nanoparticle dispersion liquid production apparatus according to claim 14, comprising: Further, at least one of the particle size distribution measuring means for the particles, the viscosity measuring means for the dispersion, the stirring torque measuring means for the beads mill, the stirring power measuring means for the beads mill, and the light transmittance measuring means for the dispersion. Data processing means capable of calculating the amount of change per hour of the measured value measured by the means;
The nanoparticle dispersion liquid production apparatus according to claim 14, comprising:   The nanoparticle dispersion liquid produced by the method according to claim 1 is polymerized, or the polymerization initiator is added to the nanoparticle dispersion liquid produced by the method according to claim 1, and then the solution is polymerized to obtain nanoparticle dispersion. A method for producing a nanocomposite material, comprising producing a composite material.   The nanocomposite material manufactured by the method of Claim 17.   18. An automobile containing a nanocomposite material obtained by the method of claim 17 having transparency and at least one of flame retardancy, heat resistance, solvent resistance, gas barrier properties, and ultraviolet blocking properties. Materials, cosmetics, optical materials.

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