JP2008056873A - Nanocomposite and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a nanocomposite which is obtained by dispersing nanoparticles into a dispersion medium, has extremely excellent dispersibility of nanoparticles into a dispersion medium and increases a concentration of nanoparticles in a nanocomposite and to provide a method for producing such a nanocomposite. <P>SOLUTION: The nanocomposite is obtained by dispersing nanoparticles into a dispersion medium. The nanoparticles have a surface modified layer (B) having thickness of 0.1-10 nm on the surfaces of particles (A) having particle diameters of 1 nm-1μm. The amount of the surface modified layer (B) is ≤60 wt.% based on the particles (A). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a nanocomposite in which nanoparticles are dispersed in a dispersion medium and a method for producing the nanocomposite.

  Among compositions in which particles are dispersed in a dispersion medium, a composition in which nanoparticles having a particle size in the nano order (several nm to several hundred nm) are dispersed in a dispersion medium is called a nanocomposite. . Nanocomposites are used for optical materials, light-shielding materials, high-strength materials, high heat-resistant materials, flame-retardant materials, color filters, and the like.

  Nanoparticles have a very small particle size and a large specific surface area. For this reason, the surface state of the nanoparticles, for example, the presence of functional groups on the surface, adsorbed water on the surface, etc., greatly affects the dispersion state of the nanoparticles in the dispersion medium during nanocomposite formation. Therefore, in order to uniformly disperse the nanoparticles in the dispersion medium, it is necessary to appropriately control the surface state of the nanoparticles.

Several methods for modifying the surface of nanoparticles have been proposed (see, for example, Patent Documents 1 and 2). However, the nanoparticles whose surface has been modified by the methods proposed so far have the disadvantage that the dispersibility at a high concentration in the dispersion medium is not sufficient. For this reason, for example, when the obtained nanocomposite is made into a film, there is a problem that it is inferior in transparency, and a problem that it is difficult to obtain a nanocomposite containing nanoparticles at a high concentration.
Special table 2003-512498 gazette JP 2004-194148 A

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is a nanocomposite in which nanoparticles are dispersed in a dispersion medium, and the dispersibility of the nanoparticles in the dispersion medium is extremely high. An object of the present invention is to provide a nanocomposite that is excellent and is capable of increasing the concentration of nanoparticles in the nanocomposite. Moreover, it is providing the method which can manufacture such a nanocomposite.

  The present inventors have intensively studied to solve the above problems. As a result, if nanoparticles having a surface modification layer with a specific thickness in a specific thickness or less are used on the surface of particles having a specific particle size, the nanoparticles are dispersed in the dispersion medium. The present inventors have found that a nanocomposite is obtained that is extremely excellent in properties and is capable of increasing the concentration of nanoparticles in the nanocomposite.

  The nanocomposite as described above is a pulverized mixture of a mixture of particles having a specific particle size, a surface modifier, an organic solvent having a boiling point of 30 ° C. or higher and lower than 100 ° C., and an organic solvent having a boiling point of 100 ° C. or higher and lower than 200 ° C. It discovered that it could manufacture by the manufacturing method including the process of performing a process, and the process of removing the organic solvent (C) of this boiling point 30 degreeC or more and less than 100 degreeC at 180 degrees C or less.

The nanocomposite of the present invention is
A nanocomposite in which nanoparticles are dispersed in a dispersion medium,
The nanoparticles have a surface modified layer (B) having a thickness of 0.1 to 10 nm on the surface of particles (A) having a particle diameter of 1 nm to 1 μm, and the surface modified layer (B) is formed on the particles (A). The amount is 60% by weight or less.

  In a preferred embodiment, the particles (A) are made of metal, metal oxide, metal nitride, metal nitrogen oxide, metal boride, metal silicide, thermoplastic resin, thermosetting resin, or photocurable resin. At least one selected.

  In a preferred embodiment, the surface modification layer (B) includes a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a metal organic compound having a methoxy group, a metal organic compound having an ethoxy group, and an organic resin. It is formed from at least one surface modifier selected from

  In a preferred embodiment, the dispersion medium is at least one selected from a thermoplastic resin, a thermosetting resin, a photocurable resin, and an organic solvent.

  In a preferred embodiment, the absolute value of the difference in solubility parameter SP value between the surface modifier forming the surface modified layer (B) and the dispersion medium is 2 or less.

The method for producing the nanocomposite of the present invention comprises:
A method for producing a nanocomposite in which nanoparticles are dispersed in a dispersion medium,
The nanoparticles have a surface modified layer (B) having a thickness of 0.1 to 10 nm on the surface of particles (A) having a particle diameter of 1 nm to 1 μm, and the surface modified layer (B) is formed on the particles (A). In an amount of 60% by weight or less,
Crushing and mixing of a mixture containing particles (A) having a particle diameter of 1 nm to 1 μm, a surface modifier, an organic solvent (C) having a boiling point of 30 ° C. or higher and lower than 100 ° C., and an organic solvent (D) having a boiling point of 100 ° C. or higher and lower than 200 ° C. A step of performing the treatment, and a step of removing the organic solvent (C) at 180 ° C. or lower.

  In a preferred embodiment, the particles (A) are made of metal, metal oxide, metal nitride, metal nitrogen oxide, metal boride, metal silicide, thermoplastic resin, thermosetting resin, or photocurable resin. At least one selected.

  In a preferred embodiment, the surface modifier is selected from a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a metal organic compound having a methoxy group, a metal organic compound having an ethoxy group, and an organic resin. At least one.

  In a preferred embodiment, the dispersion medium is at least one selected from a thermoplastic resin, a thermosetting resin, a photocurable resin, and an organic solvent.

  In a preferred embodiment, the absolute value of the difference in solubility parameter SP value between the surface modifier and the dispersion medium is 2 or less.

  In a preferred embodiment, the crushing and mixing treatment is performed by at least one selected from a planetary mill, a bead mill, and a wet jet mill.

  In preferable embodiment, 0.1-50 weight% of said organic solvents (D) are contained in the said nanoparticle.

In a preferred embodiment, the FT-IR spectrum of the particles obtained by the step of removing the organic solvent (C) at 180 ° C. or lower is higher than the FT-IR spectrum of the particles before the step. The absorption peak intensity at 3300 cm ⁻¹ showing OH stretching vibration is 20% or more smaller, or the absorption peak wave number showing C—O—C stretching vibration is 5 to 20 cm ⁻¹ smaller.

According to the present invention, a nanocomposite in which nanoparticles are dispersed in a dispersion medium, the dispersibility of the nanoparticles in the dispersion medium is extremely excellent, and the concentration of the nanoparticles in the nanocomposite can be increased. Nanocomposites can be provided.
According to the present invention, the choices of combinations of nanoparticles and a dispersion medium are expanded. For example, it is possible to provide a nanocomposite in which hydrophilic nanoparticles are dispersed at a high concentration in a nonpolar medium.
Moreover, the method which can manufacture such a nanocomposite can be provided. According to the present invention, since nanoparticles can be sufficiently uniformly dispersed in a dispersion medium, it is possible to provide a highly transparent nanocomposite and a nanocomposite containing nanoparticles at a high concentration. .

Hereinafter, although preferable embodiment of this invention is described, this invention is not limited to these embodiment.
[1. Nanoparticles
The nanoparticles in the present invention have a surface modified layer (B) on the surface of the particles (A). The surface modification layer (B) may form a layer uniformly on the surface of the particles (A) or may form a layer nonuniformly. Moreover, the surface modification layer (B) may substantially cover the entire surface of the particles (A), or may partially cover the surfaces of the particles (A).

  The particle diameter of the particles (A) is 1 nm to 1 μm, preferably 5 nm to 500 nm, more preferably 10 nm to 250 nm, and still more preferably 10 nm to 150 nm. When the particle size of the particles (A) is smaller than 1 nm, the particle size is too small, and thus there is a possibility of adversely affecting the dispersion state of the nanoparticles in the dispersion medium when forming the nanocomposite. If the particle size of the particles (A) is larger than 1 μm, the particle size is too large, and there is a possibility that a nanocomposite cannot be formed.

  Arbitrary appropriate particle | grains can be employ | adopted as particle | grains (A). Preferably, it is at least one selected from metals, metal oxides, metal nitrides, metal nitrogen oxides, metal borides, metal silicides, thermoplastic resins, thermosetting resins, and photocurable resins. In order to further exert the effect of the present invention, more preferably, silicon oxide, zirconium oxide, titanium oxide, aluminum oxide, iron oxide, yttrium oxide, zinc oxide, silver oxide, barium titanate, calcium carbonate, magnesium oxide Metal oxides. Only 1 type may be used for a particle | grain (A) and it may use 2 or more types together.

  The thickness of the surface modified layer (B) is 0.1 to 10 nm, preferably 0.1 to 8 nm, more preferably 0.1 to 5 nm, and particularly preferably 0.2 to 4 nm. If the thickness of the surface modification layer (B) is smaller than 0.1 nm, the surface modification effect may not be exhibited. When the thickness of the surface modified layer (B) is larger than 10 nm, there is a possibility of adversely affecting the dispersion state of the nanoparticles in the dispersion medium during nanocomposite formation. When the particle size of the particles (A) is 100 nm or less, the thickness of the surface modified layer (B) is more preferably 0.1 to 2 nm or less, and when the particle size of the particles (A) is larger than 100 nm. The thickness of the surface modification layer (B) is more preferably 2 to 10 nm.

  The surface modified layer (B) is in an amount of 60% by weight or less based on the particles (A), preferably 1 to 60% by weight, more preferably 2 to 50% by weight, still more preferably 2 to 45% by weight, Particularly preferred is 2 to 30% by weight. When the amount of the surface modified layer (B) is larger than 60% by weight with respect to the particles (A), there is a possibility of adversely affecting the dispersion state of the nanoparticles in the dispersion medium during the nanocomposite formation.

  The surface modification layer (B) can be formed from any suitable surface modifier. Preferably, a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a metal organic compound having a methoxy group, a metal organic compound having an ethoxy group, or at least one surface modifier selected from organic resins Is done. The surface modification layer (B) may be formed of only one type of surface modifier or may be formed of two or more types of surface modifiers.

  When the nanoparticle in the present invention has the surface modified layer (B) on the surface of the particle (A), the dispersibility of the nanoparticle in the dispersion medium becomes extremely excellent. In addition, it is possible to increase the concentration of nanoparticles in the nanocomposite.

[2. (Nanocomposite)
The nanocomposite of the present invention is obtained by dispersing nanoparticles in a dispersion medium.

  Any appropriate dispersion medium can be adopted as the dispersion medium. Preferably, it is at least one selected from a thermoplastic resin, a thermosetting resin, a photocurable resin, and an organic solvent. In order to further exert the effect of the present invention, at least one selected from a thermoplastic resin and a thermosetting resin is more preferable. Examples of the thermoplastic resin include polyolefin, polar vinyl resin, cellulose derivative and the like. Examples of the thermosetting resin include phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, silicon resin, and polyurethane. Only one type of dispersion medium may be used, or two or more types may be used in combination.

  The content ratio of the nanoparticles in the nanocomposite of the present invention is preferably 0.001 to 80% by weight, more preferably 0.01 to 70% by weight, still more preferably 0.1 to 60% by weight, and particularly preferably 0. 0.5 to 50% by weight. When the content ratio of the nanoparticles in the nanocomposite of the present invention is less than 0.001% by weight, the effects due to the incorporation of the nanoparticles may not be sufficiently exhibited. When the content ratio of the nanoparticles in the nanocomposite of the present invention is more than 80% by weight, it may be difficult to form the nanocomposite.

  The nanocomposite of the present invention may contain any appropriate additive as long as the effects of the present invention are not impaired. Examples of the additive include a dispersant, a colorant, an antiseptic, a moisturizer, an ultraviolet absorber, an ultraviolet stabilizer, a fragrance, and a polymer other than the dispersion medium.

In the nanocomposite of the present invention, the absolute value of the difference in the solubility parameter SP value between the surface modifier and the dispersion medium forming the surface modified layer (B) is preferably 2 or less, more preferably 1.5. Or less, more preferably 1.0 or less. If the absolute value of the difference in solubility parameter SP value between the surface modifier and the dispersion medium forming the surface modification layer (B) is 2 or less, the compatibility of the surface-modified particles with the dispersion medium is improved. In addition, it is possible to achieve extremely excellent dispersibility of the finally obtained nanoparticles in the dispersion medium. Here, the unit of the SP value is (cal / cm ³ ) ^1/2 .

  Arbitrary appropriate forms can be employ | adopted for the form of the nanocomposite of this invention. For example, it may be in the form of a dispersion or in the form of a film.

[3. (Nanocomposite production method)
The method for producing a nanocomposite of the present invention comprises a particle (A) having a particle size of 1 nm to 1 μm, a surface modifier, an organic solvent (C) having a boiling point of 30 ° C. or higher and lower than 100 ° C., and an organic solvent having a boiling point of 100 ° C. or higher and lower than 200 ° C. (D) including a step of crushing and mixing the mixture (sometimes referred to as a “surface modification treatment step”).

  Examples of the particles (A) used in the surface modification treatment step include [1. The explanation in the section of “Nanoparticles” is incorporated.

  Any appropriate surface modifier may be employed as the surface modifier used in the surface modification treatment step. Preferably, at least one selected from a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a metal organic compound having a methoxy group, a metal organic compound having an ethoxy group, and an organic resin can be used. Only one type of surface modifier may be used, or two or more types may be used.

  As the organic solvent (C) used in the surface modification treatment step, any appropriate organic solvent can be adopted as long as it is an organic solvent having a boiling point of 30 ° C. or higher and lower than 100 ° C. Specifically, acetone, cyclohexane, ethyl acetate, methyl ethyl ketone, etc. are mentioned, for example.

  As the organic solvent (D) used in the surface modification treatment step, any appropriate organic solvent can be adopted as long as it is an organic solvent having a boiling point of 100 ° C. or higher and lower than 200 ° C. Specific examples include toluene, xylene, butyl acetate, methyl isobutyl ketone, and propylene glycol methyl ether.

  In the surface modification treatment step, the mixture containing the particles (A), the surface modifier, the organic solvent (C), and the organic solvent (D) is crushed and mixed. The mixture may contain any appropriate additive as long as the effects of the present invention are not impaired.

  Arbitrary appropriate methods can be employ | adopted for the crushing mixing process in a surface modification process process. Preferably, it is performed by at least one selected from a planetary mill, a bead mill, and a wet jet mill.

  A surface modification layer (B) is formed on the surface of the particles (A) by the surface modification treatment step.

  By the surface modification treatment step, the surface modified layer (B) is formed on the surface of the particles (A), and the organic solvent (C) and the organic solvent (D) can remain.

  It can be confirmed by any appropriate measurement method that the surface modification treatment step has been performed. For example, it can be confirmed by a significant difference occurring in the FT-IR spectrum.

  The method for producing a nanocomposite of the present invention includes a step of removing the solvent of the organic solvent (C) at 180 ° C. or lower (sometimes referred to as “non-water treatment step”). Any appropriate method can be adopted as a method of solvent removal treatment in the non-water treatment step. For example, vacuum deaeration is mentioned. The temperature of the solvent removal treatment is preferably 30 to 180 ° C, more preferably 50 to 150 ° C, still more preferably 80 to 150 ° C, and particularly preferably 100 to 150 ° C.

  By performing the solvent removal treatment of the organic solvent (C) by the non-hydration treatment step, the organic solvent (C) and the adsorbed water or generated water (for example, the surface treatment agent and the particles ( A) water produced by dehydration condensation with hydroxyl groups on the surface is removed, and when there are functional groups (for example, hydroxyl groups) on the surface of the particles (A), the functional groups can also be removed. By such an action, the bond between the surface modified layer (B) and the particles (A) becomes extremely strong. Furthermore, since the non-water treatment process is performed at a relatively low temperature of 180 ° C. or lower, aggregation of the surface-modified particles (A) can be suppressed.

  By the non-water treatment process as described above, nanoparticles having an extremely strong bond between the surface modified layer (B) and the particles (A) can be obtained. Furthermore, the adsorbed water, generated water, and functional groups that existed on the surface of the particles (A) before the dehydration treatment step can be removed by the dehydration treatment step as described above. Therefore, the dispersibility of the nanoparticles in the dispersion medium is extremely excellent, and when a nanocomposite is obtained, the concentration of nanoparticles in the nanocomposite can be increased.

  In the nanoparticles obtained by the non-water treatment step, the organic solvent (D) is preferably 0.1 to 50% by weight, more preferably 0.1 to 30% by weight, and still more preferably 0.1 to 20%. % By weight, particularly preferably 0.1 to 10% by weight. When the organic solvent (D) is contained in the above-mentioned amount in the nanoparticles obtained by the non-water treatment process, the dispersibility of the nanoparticles in the dispersion medium is further improved, and a nanocomposite is obtained. Sometimes, it is possible to further increase the concentration of nanoparticles in the nanocomposite.

It can be confirmed by any appropriate measurement method that the non-water treatment step has been performed. For example, it can be confirmed that a significant difference occurs in the spectrum by FT-IR. Specifically, for example, the absorption peak at 3300 cm ⁻¹ in which the FT-IR spectrum of the particles obtained by the non-water treatment process shows OH stretching vibration compared to the FT-IR spectrum of the particles before the process is performed. It can be observed that the intensity is 20% or more smaller, or the absorption peak wave number indicating C—O—C stretching vibration is 5 to 20 cm ⁻¹ smaller.

  In the method for producing a nanocomposite of the present invention, after the non-water treatment process is performed, preferably, the obtained nanoparticles are dispersed in a dispersion medium (sometimes referred to as “nanodispersion process process”). including.

  In the nano-dispersion treatment step, the mixture containing the nanoparticles and the dispersion medium obtained in the non-water treatment step is subjected to a dispersion treatment. The mixture may contain any appropriate additive. In order to perform an efficient dispersion treatment or the like, it is preferable that a dispersant or a dispersion solvent is contained in the mixture.

  As a dispersion medium used in the nano-dispersion treatment step, [2. The explanation in the item of “Nanocomposite” is incorporated.

The absolute value of the difference in solubility parameter SP value between the dispersion medium used in the nanodispersion treatment step and the surface modifier used in the surface modification treatment step is preferably 2 or less, more preferably 1.5 or less, More preferably, it is 1.0 or less. If the absolute value of the difference in solubility parameter SP value between the surface modifier and the dispersion medium is 2 or less, the compatibility of the surface-modified particles with the dispersion medium is improved, and the finally obtained nanoparticles It becomes possible to make the dispersion into the dispersion medium extremely excellent. Here, the unit of the SP value is (cal / cm ³ ) ^1/2 .

  Any appropriate solvent can be adopted as a dispersion solvent that can be used in the nano-dispersion treatment step. For example, the above [3. Examples thereof include the organic solvent (C) and the organic solvent (D) described in the item “Production method of nanocomposite”.

  Any appropriate dispersion method can be adopted as a dispersion treatment method in the nano-dispersion treatment step. For example, a dispersion treatment using a homogenizer, a wet jet mill, or the like can be given.

  The nano-dispersion treatment step provides a nano-particle dispersion that is preferably transparent.

  The dispersion obtained by the nano-dispersion treatment step may be a nanocomposite as referred to in the present invention, and further after a step of performing a solvent removal treatment (sometimes referred to as a “solvent removal treatment step”), the present invention. It is good also as a nanocomposite.

  In the solvent removal treatment step, preferably, the dispersion solvent used in the nanodispersion treatment step and the organic solvent (D) that can remain in the dispersion (nanocomposite) obtained by the nanodispersion treatment step can be removed.

  Any appropriate method can be adopted as a method of solvent removal treatment in the solvent removal treatment step. For example, the dispersion liquid (nanocomposite) obtained by a nano dispersion | distribution process process is cast on a board | substrate (for example, glass substrate), The method of removing the said dispersion | distribution solvent and organic solvent (D) from a cast film | membrane etc. is mentioned.

[4. Applications of nanocomposites)
The nanocomposite of the present invention or the nanocomposite obtained by the production method of the present invention can be used for any appropriate application. For example, optical use, electrical use, chemical use, mechanical use, thermal use and the like can be mentioned.

  Examples of the optical application include a refractive index adjusting material, a low reflection material, a UV absorption material, an IR reflection material, a light scattering material, an FPD material, an organic photoconductor, and a high function pigment.

  Electrical applications include conductive materials, insulating materials (High-k, Low-k, High-Q), ion conductive materials, sensors / actuators, battery materials, and electrical / magnetic functional materials. .

  Chemical applications include printing materials, inks, catalysts, pharmaceuticals, foods, bioactive materials, nanoencapsulated materials, barrier materials, and the like.

  Examples of mechanical applications include high hardness materials, high Young's modulus materials, high adhesion materials, film forming materials, and friction and wear resistant materials.

  Thermal applications include heat resistant materials, low thermal expansion materials, flame retardant materials, thermally conductive materials and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. Unless otherwise indicated, parts and percentages in the examples are based on weight.

[Example 1]
(1) Materials a) Nanoparticles: manufactured by Japan Aerosil "Aerosil200" (average particle size 12nm, BET200m ² / g) of SiO ₂ nanoparticles b) dispersing medium: Zeon cycloolefin resin "Zeonex480R" (SP value 8 .3)
c) Surface modifier: “KR TTS” manufactured by Ajinomoto Fine Techno (titanate coupling agent, density 0.95, SP value 8.1)
d) Dispersion solvent: Cyclohexane manufactured by Nacalai Tesque (boiling point 80.7 ° C., SP value 8.2)
e) Organic solvent (C) (an organic solvent having a boiling point of 30 ° C. or higher and lower than 100 ° C.): cyclohexane (boiling point 80.7 ° C.) manufactured by Nacalai Tesque
f) Organic solvent (D) (an organic solvent having a boiling point of 100 ° C. or more and less than 200 ° C.): Xylene made by Nacalai Tesque (boiling point 140 ° C., SP value 8.8)
Here, the unit of the SP value is (cal / cm ³ ) ^1/2

(2) Surface Modification Process Step 2.01 g of Aerosil 200 SiO ₂ nanoparticles, 1.02 g of titanate coupling agent of KR TTS, 1.07 g of xylene and 17.2 g of acetone are placed in a glass container. A 1 minute homogenizer treatment was performed three times with an ultrasonic homogenizer from Seiki Seisakusho. Subsequently, crushing and mixing were performed using a wet jet mill manufactured by Genus. The thickness of the surface modification layer of the titanate coupling agent was 2.6 nm. An outline of the state change of particles in the surface modification treatment step is shown in FIG.

(3) Non-water treatment step The particles obtained in the surface modification treatment step were heated to 100 ° C to 120 ° C and vacuum degassed to remove OH groups and adsorbed water on the particle surface. After the dehydration treatment, xylene contained in the particles was 8% by weight. The outline of the state change of the particle | grains in a non-hydration process is shown in FIG.

(4) Nano-dispersion treatment step 1.07 g of nanoparticles (SiO ₂ : 62% by weight, coupling agent: 31% by weight, xylene: 8% by weight) obtained in the non-water treatment step, and 1 cycloolefin polymer .23 g and 23.6 g of cyclohexane were prepared. This was pre-dispersed with an ultrasonic homogenizer from Nippon Seiki Seisakusho for 1 minute. Subsequently, dispersion treatment was performed using a wet jet mill manufactured by Genus. A transparent dispersion having the following composition and excellent dispersibility of nanoparticles was obtained.
(Composition of dispersion)
SiO ₂ : 2.5% by weight
Zeonex 480R: 4.7% by weight
Coupling agent: 1.3% by weight
Cyclohexane: 91.1% by weight
Xylene: 0.3% by weight

(5) Solvent removal treatment step After the dispersion obtained in the nano-dispersion treatment step was cast on a glass substrate, the cyclohexane was gradually removed from the cast film in a cyclohexane atmosphere to produce a transparent film having a thickness of 150 μm. . The obtained film was transparent without being clouded even when the film contained about 30% by weight of SiO ₂ particles.
(Composition of film)
SiO ₂ : 29.8% by weight
Zeonex 480R: 55.4% by weight
Coupling agent: 14.9% by weight

[Example 2]
(1) Materials a) Nanoparticles: ZrO ₂ nanoparticles of “ZrO2-UFP” (average particle size 8 nm, BET 142 m ² / g) manufactured by Nisshin Flour Milling b) Dispersion medium: cycloolefin resin of “Zeonex 480R” manufactured by Nippon Zeon ( SP value 8.3)
c) Surface modifier: “KR TTS” manufactured by Ajinomoto Fine Techno (titanate coupling agent, density 0.95, SP value 8.1)
d) Dispersing solvent: cyclohexane (boiling point 80.7 ° C., SP value 8.2) manufactured by Nacalai Tesque
e) Organic solvent (C) (an organic solvent having a boiling point of 30 ° C. or higher and lower than 100 ° C.): cyclohexane (boiling point 80.7 ° C.) manufactured by Nacalai Tesque
f) Organic solvent (D) (an organic solvent having a boiling point of 100 ° C. or more and less than 200 ° C.): Xylene made by Nacalai Tesque (boiling point 140 ° C., SP value 8.8)
Here, the unit of the SP value is (cal / cm ³ ) ^1/2

(2) Surface modification treatment step ZrO2-UFP ZrO ₂ nanoparticles 2.21g, KR TTS titanate coupling agent 1.03g, xylene 1.1g, acetone 17.9g, put in a glass container Then, the homogenizer treatment for 1 minute was performed 3 times with the ultrasonic homogenizer of Nippon Seiki Seisakusho. Subsequently, crushing and mixing were performed using a wet jet mill manufactured by Genus. The thickness of the surface modification layer of the titanate coupling agent was 3.4 nm.

(3) Non-water treatment step The particles obtained in the surface modification treatment step were heated to 100 ° C to 120 ° C and vacuum degassed to remove OH groups and adsorbed water on the particle surface. After the dehydration treatment, xylene contained in the particles was 0.4% by weight.

(4) Nano-dispersion treatment step 1.5 g of nanoparticles (ZrO ₂ : 68.0 wt%, coupling agent: 31.6 wt%, xylene: 0.4 wt%) obtained in the non-hydration treatment step 1.26 g of cycloolefin polymer and 23.7 g of cyclohexane were prepared. This was pre-dispersed with an ultrasonic homogenizer from Nippon Seiki Seisakusho for 1 minute. Subsequently, dispersion treatment was performed using a wet jet mill manufactured by Genus. A transparent dispersion with excellent dispersibility of the nanoparticles was obtained.

Example 3
(1) Materials a) Nanoparticles: BaTiO ₃ nanoparticles of “BTO30” (average particle size 30 nm, BET 31 m ² / g) manufactured by Toda Kogyo b) Dispersion medium: cycloolefin resin (SP value 8) of “Zeonex 480R” manufactured by Nippon Zeon .3)
c) Surface modifier: “KR TTS” manufactured by Ajinomoto Fine Techno (titanate coupling agent, density 0.95, SP value 8.1)
d) Dispersion solvent: Cyclohexane manufactured by Nacalai Tesque (boiling point 80.7 ° C., SP value 8.2)
e) Organic solvent (C) (an organic solvent having a boiling point of 30 ° C. or higher and lower than 100 ° C.): cyclohexane (boiling point 80.7 ° C.) manufactured by Nacalai Tesque
f) Organic solvent (D) (an organic solvent having a boiling point of 100 ° C. or more and less than 200 ° C.): Xylene made by Nacalai Tesque (boiling point 140 ° C., SP value 8.8)
Here, the unit of the SP value is (cal / cm ³ ) ^1/2

(2) Surface modification treatment step 2.01 g of BaTiO ₃ nanoparticles of BTO30, 0.16 g of titanate coupling agent of KR TTS, 1.0 g of xylene and 9.5 g of acetone are placed in a glass container. A 1 minute homogenizer treatment was performed three times with an ultrasonic homogenizer from Seiki Seisakusho. Subsequently, crushing and mixing were performed using a wet jet mill manufactured by Genus. The thickness of the surface modification layer of the titanate coupling agent was 2.7 nm.

(3) Non-water treatment step The particles obtained in the surface modification treatment step were heated to 100 ° C to 120 ° C and vacuum degassed to remove OH groups and adsorbed water on the particle surface. After the dehydration treatment, xylene contained in the particles was 4% by weight.

(4) Nano-dispersion treatment step 1.0 g of nanoparticles (BaTiO ₃ : 89.0% by weight, coupling agent: 7% by weight, xylene: 4% by weight) obtained in the non-water treatment step, cycloolefin polymer 1.22 g and cyclohexane 23.8 g. This was pre-dispersed with an ultrasonic homogenizer from Nippon Seiki Seisakusho for 1 minute. Subsequently, dispersion treatment was performed using a wet jet mill manufactured by Genus. A transparent dispersion with excellent dispersibility of the nanoparticles was obtained.

Example 4
(1) Materials a) Nanoparticles: BaTiO ₃ nanoparticles of “BTO30” (average particle size 30 nm, BET 31 m ² / g) manufactured by Toda Kogyo b) Dispersion medium: bisphenol A epoxy resin (curing agent) of “Epicoat 828” manufactured by JER (Addition of 5% dicyandiamide DICY7) (SP value 10.6)
c) Surface modifier: Bisphenol A epoxy resin (density 1.2, SP value 8.1) of “Epicoat 828” manufactured by JER
d) Dispersion solvent: acetone made by Nacalai Tesque (boiling point 56.1 ° C., SP value 9.8)
e) Organic solvent (C) (an organic solvent having a boiling point of 30 ° C. or higher and lower than 100 ° C.):
Nacalai Tesque acetone (boiling point 56.1 ° C, SP value 9.8)
f) Organic solvent (D) (organic solvent having a boiling point of 100 ° C. or higher and lower than 200 ° C.): PGME manufactured by Nacalai Tesque (boiling point 120 ° C., SP value 10.6)
Here, the unit of the SP value is (cal / cm ³ ) ^1/2

(2) Surface modification treatment step 10 g of BaTiO ₃ nanoparticles of BTO30, 0.31 g of Epicoat 828, 1.02 g of PGME, and 12.6 g of acetone are placed in a glass container, and a planetary mill manufactured by Frichu Japan Co., Ltd. Was crushed and mixed for 60 minutes. The thickness of the surface modification layer of bisphenol A epoxy resin was 0.2 nm.

(3) Non-water treatment step The particles obtained in the surface modification treatment step were heated to 80 ° C and vacuum degassed to remove OH groups and adsorbed water on the particle surface. After this dehydration treatment, the PGME contained in the particles was 8.85% by weight.

(4) Nano-dispersion treatment step 2. Nanoparticles (BaTiO ₃ : 88.5% by weight, bisphenol A epoxy resin: 2.65% by weight, PGME: 8.85% by weight) obtained in the non-hydration treatment step. 0 g, 2.0 g of Epicoat 828 (added with 5% of a curing agent dicyandiamide DICY7), 10 g of PGME, 20 g of acetone, and 0.14 g of a dispersant (“A212C” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were prepared. This was pre-dispersed with an ultrasonic homogenizer from Nippon Seiki Seisakusho for 1 minute. Subsequently, dispersion treatment was performed using a wet jet mill manufactured by Genus. A transparent dispersion having the following composition and excellent dispersibility of nanoparticles was obtained.
(Composition of dispersion)
BaTiO ₃ : 5.2% by weight
Bisphenol A epoxy resin: 6.0% by weight
PGME: 29.8% by weight
Acetone: 58.6% by weight
Dispersant: 0.4% by weight

(5) Thin film formation The dispersion liquid obtained in the non-aqueous treatment process was spin-coated at a rotation speed of 2000 rpm on a substrate on which a Pt electrode was formed on a silicon wafer. After drying at 100 ° C. for 10 minutes, heating was performed at 180 ° C. for 2 minutes. This treatment was further repeated twice, and then heat curing was performed at 180 ° C. for 60 minutes. The film thickness at this time was 0.5 μm. Further, Au was vacuum-deposited using a metal mask having 3 × 4 mm ² holes. The impedance of the completed device for measuring the dielectric constant was measured. As a result, a dielectric constant of 21 was obtained at 1 kHz.

Example 5
(1) Material a) Nanoparticles: BaTiO ₃ nanoparticles of “BTO30” (average particle size 30 nm, BET 31 m ² / g) manufactured by Toda Kogyo b) Dispersion medium: bisphenol A epoxy resin (curing agent) of “Epicoat 828” manufactured by JER (Addition of 5% dicyandiamide DICY7) (SP value 10.6)
c) Surface modifier: bisphenol A epoxy resin (density 1.2, SP value 8.1) made by JER "Epicoat 828"
d) Dispersion solvent: acetone made by Nacalai Tesque (boiling point 56.1 ° C., SP value 9.8)
e) Organic solvent (C) (an organic solvent having a boiling point of 30 ° C. or higher and lower than 100 ° C.):
Nacalai Tesque acetone (boiling point 56.1 ° C, SP value 9.8)
f) Organic solvent (D) (an organic solvent having a boiling point of 100 ° C. or more and less than 200 ° C.): Xylene made by Nacalai Tesque (boiling point 140 ° C., SP value 8.8)
Here, the unit of the SP value is (cal / cm ³ ) ^1/2

(2) Surface modification treatment step Put 2.5 g of BaTiO ₃ nanoparticles of BTO30, 0.14 g of Epicoat 828, 2 g of xylene, and 25 g of acetone into a glass container, and use a planetary mill manufactured by Frichu Japan. For 60 minutes. The thickness of the surface modification layer of bisphenol A epoxy resin was 1.5 nm.

(3) Non-water treatment process The particles obtained in the surface modification treatment process are vacuum degassed at 50 ° C. for 60 minutes or at 120 ° C. for 10 minutes, whereby OH groups and adsorbed water on the particle surface Was removed. Nanoparticles (5-1) are nanoparticles obtained by vacuum degassing at 50 ° C. for 60 minutes, and nanoparticles (5-2) are nanoparticles obtained by vacuum degassing at 120 ° C. for 10 minutes.

(4) FTIR measurement The FT-IR of the nanoparticle (5-1) and nanoparticle (5-2) was measured. The results are shown in FIG.

[Comparative Example 1]
The particles obtained without performing the surface modification treatment step in Example 5 were degassed at 50 ° C. for 60 minutes to remove OH groups and adsorbed water on the particle surfaces. Let the obtained nanoparticle be a nanoparticle (5-3).

(4) FTIR measurement The FT-IR of the nanoparticle (5-3) was measured. Moreover, FT-IR of Epicoat 828 and BTO30 was measured. The results are shown in FIG.

[Evaluation of FT-IR]
When FIG. 2 is seen, it turns out that the peak corresponding to water becomes small, so that the temperature of a non-water-treatment process becomes high (3300-3400 cm ^-1 vicinity). Further, when the FT-IR spectra of the nanoparticles (5-2) and the nanoparticles (5-3) are compared, the absorption peak intensity at 3300 cm ⁻¹ exhibiting OH stretching vibration is 20% or more smaller, or C—O— It can be seen that the absorption peak wave number indicating C stretching vibration is 5 to 20 cm ⁻¹ smaller.

  The nanocomposite of the present invention or the nanocomposite obtained by the production method of the present invention includes, for example, an optical material (high refractive index, transparency), a light shielding material (specific wavelength cut, high transparency), a high strength material, a high It can be used for heat resistant materials, flame retardant materials, color filters and the like.

It is the schematic of the state change of the particle | grains in a surface modification process process and a non-water-treatment process. It is a FT-IR spectrum figure of a nanoparticle.

Claims (13)

A nanocomposite in which nanoparticles are dispersed in a dispersion medium,
The nanoparticles have a surface modified layer (B) having a thickness of 0.1 to 10 nm on the surface of particles (A) having a particle diameter of 1 nm to 1 μm, and the surface modified layer (B) is formed on the particles (A). An amount of 60% by weight or less,
Nanocomposite.   The particles (A) are at least one selected from metals, metal oxides, metal nitrides, metal nitrogen oxides, metal borides, metal silicides, thermoplastic resins, thermosetting resins, and photocurable resins. The nanocomposite according to claim 1.   The surface modification layer (B) is at least one selected from a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a metal organic compound having a methoxy group, a metal organic compound having an ethoxy group, and an organic resin. The nanocomposite according to claim 1 or 2, wherein the nanocomposite is formed from a surface modifier.   The nanocomposite according to any one of claims 1 to 3, wherein the dispersion medium is at least one selected from a thermoplastic resin, a thermosetting resin, a photocurable resin, and an organic solvent.   The nanocomposite according to any one of claims 1 to 4, wherein an absolute value of a difference in solubility parameter SP value between the surface modifier forming the surface modified layer (B) and the dispersion medium is 2 or less. . A method for producing a nanocomposite in which nanoparticles are dispersed in a dispersion medium,
The nanoparticles have a surface modified layer (B) having a thickness of 0.1 to 10 nm on the surface of particles (A) having a particle diameter of 1 nm to 1 μm, and the surface modified layer (B) is formed on the particles (A). In an amount of 60% by weight or less,
Crushing and mixing of a mixture containing particles (A) having a particle diameter of 1 nm to 1 μm, a surface modifier, an organic solvent (C) having a boiling point of 30 ° C. or higher and lower than 100 ° C., and an organic solvent (D) having a boiling point of 100 ° C. or higher and lower than 200 ° C. A step of performing a treatment, and a step of performing a solvent removal treatment of the organic solvent (C) at 180 ° C. or lower.
A method for producing a nanocomposite.   The particles (A) are at least one selected from metals, metal oxides, metal nitrides, metal nitrogen oxides, metal borides, metal silicides, thermoplastic resins, thermosetting resins, and photocurable resins. The method for producing a nanocomposite according to claim 6.   The surface modifier is at least one selected from a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a metal organic compound having a methoxy group, a metal organic compound having an ethoxy group, and an organic resin. The method for producing a nanocomposite according to claim 6 or 7.   The method for producing a nanocomposite according to any one of claims 6 to 8, wherein the dispersion medium is at least one selected from a thermoplastic resin, a thermosetting resin, a photocurable resin, and an organic solvent.   The method for producing a nanocomposite according to any one of claims 6 to 9, wherein an absolute value of a difference in solubility parameter SP value between the surface modifier and the dispersion medium is 2 or less.   The method for producing a nanocomposite according to any one of claims 6 to 10, wherein the crushing and mixing treatment is performed by at least one selected from a planetary mill, a bead mill, and a wet jet mill.   The method for producing a nanocomposite according to any one of claims 6 to 11, wherein 0.1 to 50% by weight of the organic solvent (D) is contained in the nanoparticles. The FT-IR spectrum of the particles obtained by the solvent removal treatment of the organic solvent (C) at 180 ° C. or lower shows OH stretching vibration compared with the FT-IR spectrum of the particles before the step. 13. The nanocomposite according to claim 6, wherein the absorption peak intensity at 3300 cm ⁻¹ is smaller by 20% or more, or the absorption peak wave number indicating C—O—C stretching vibration is smaller by 5 to 20 cm ⁻¹ . Production method.