JP2013185070A - Nano-composite particle containing perfluorocarbon sulfonate polymer and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide nano-composite particles containing a perfluorocarbon sulfonate polymer which has a high proton conductivity originated from a perfluorocarbon sulfonate polymer and further has heat resistance of at least 350°C.SOLUTION: Nano-composite particles containing a perfluorocarbon sulfonate polymer can be obtained by adding to a reaction raw liquid containing (a) core silica particles having an average particle diameter of 5-200 nm, (b) alkoxy silane, (c) a perfluorocarbon sulfonate polymer and (d) a reaction solvent with ammonia of at least 1 ml on the basis of NHto 1 ml of alkoxysilane, and then hydrolyzing the alkoxysilane; and then performing a surface treatment step to the surface of core silica particles.

Description

  The present invention relates to nanocomposite particles containing a perfluorocarbon sulfonic acid polymer and a method for producing the same.

  When the particles of the substance are made smaller, ultrafine particles that exhibit a unique behavior that is completely different from the properties of the original solid are obtained. Therefore, in the composition in which the particles are dispersed in the dispersion medium, the particle diameter is Nanoparticles that are on the order of nanometers (several nm to several hundred nm) have attracted attention.

A composition 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, development of nanocomposite particles which are easy to aggregate and excellent in dispersibility is desired.
Polymer nanoparticles have also been developed and used in applications such as paints, adhesives, and coating materials, and nanocomposite particles having various functions have been studied.

  Perfluorocarbon sulfonic acid polymers such as Nafion (registered trademark) are known to have high ionic conductivity, but the 10% weight loss temperature of Nafion (registered trademark) itself is around 305 ° C., and 350 ° C. or more. There is a problem that Nafion (registered trademark) cannot be used in a high temperature environment.

  The present inventors previously conducted a hydrolysis reaction of tetraalkoxysilane in a solvent under alkaline conditions in a system containing a fluoroalkyl group oligomer, tetraalkoxysilane, core silica particles, and an organic compound of an ionic liquid as a guest compound. It was found that the nanocomposite particles obtained by the above-described process imparted excellent heat resistance to the guest compound (see, for example, Patent Documents 1 to 3).

JP 2007-270124 A JP 2009-209349 A JP 2011-190120 A

In the process of researching nanocomposite particles capable of imparting heat resistance to an organic compound serving as a guest compound, the present inventors have developed a core silica particle, tetraalkoxysilane, and a perfluorocarbon sulfonic acid polymer as the first guest compound. The nanocomposite particles obtained by hydrolyzing the tetraalkoxysilane under specific conditions using a reaction raw material solution containing nitrobenzene are those in which the heat resistance of the perfluorocarbon sulfonic acid polymer of the incorporated guest compound is improved. I found out that
In addition, a nanocomposite particle obtained by adding a specific organic compound as a second guest compound to the reaction raw material liquid and hydrolyzing the alkoxysilane is a perfluorocarbon sulfonic acid polymer of the first guest compound. The inventors have found that the heat resistance is further improved and have completed the present invention.

  Therefore, an object of the present invention is nanocomposite particles containing a perfluorocarbon sulfonic acid polymer, having high proton conductivity due to the perfluorocarbon sulfonic acid polymer, and further having heat resistance of 350 ° C. or higher. It is to provide nanocomposite particles. Another object of the present invention is to provide a method by which the nanocomposite particles can be produced by an industrially advantageous method.

That is, the first invention to be provided by the present invention includes (a) core silica particles having an average particle diameter of 5 to 200 nm, (b) alkoxysilane, (c) perfluorocarbon sulfonic acid polymer, and (d) a reaction solvent. (B) a surface treatment step of performing surface treatment of the core silica particles by adding 1 ml or more of ammonia water as NH ₃ to 1 ml of alkoxysilane and hydrolyzing the alkoxysilane to 1 ml of alkoxysilane. It is a perfluorocarbon sulfonic acid polymer-containing nanocomposite particle characterized by being obtained.

  In addition, the second invention to be provided by the present invention is that the reaction raw material liquid of the first invention is further mixed with a guest compound selected from (e) an aromatic compound and a fluorine-containing sulfonic acid compound, It is a perfluorocarbon sulfonic acid polymer-containing nanocomposite particle obtained by hydrolyzing silane and performing a surface treatment step for surface treatment of the core silica particles.

In addition, the third invention to be provided by the present invention includes (a) core silica particles having an average particle diameter of 5 to 200 nm, (b) alkoxysilane, (c) perfluorocarbon sulfonic acid polymer, and (d) a reaction solvent. (B) A surface treatment step of adding 1 ml or more of aqueous ammonia as NH ₃ to 1 ml of alkoxysilane, and subjecting the core silica particles to a surface treatment by hydrolyzing the alkoxysilane. It is a manufacturing method of the nano composite particle containing perfluorocarbon sulfonic acid polymer characterized by having.

  Further, the fourth invention to be provided by the present invention is that the reaction raw material liquid of the third invention is further mixed with a guest compound selected from (e) an aromatic compound and a fluorine-containing sulfonic acid compound, A method for producing perfluorocarbon sulfonic acid polymer-containing nanocomposite particles, comprising a surface treatment step of hydrolyzing silane to surface-treat the core silica particles.

  A fifth invention to be provided by the present invention is a nanocomposite particle dispersion liquid comprising the perfluorocarbonsulfonic acid polymer-containing nanocomposite particles of the first and second inventions.

  According to the present invention, nanocomposite particles containing a perfluorocarbon sulfonic acid polymer, having excellent proton conductivity, and having heat resistance of 350 ° C. or higher can be provided. . Moreover, according to the present invention, the nanocomposite particles can be provided by an industrially advantageous method.

The TGA chart of the nanocomposite particle obtained in Examples 1-4. The TGA chart of the nanocomposite particle obtained in Examples 5-11. The TGA chart of the nanocomposite particle obtained in Examples 12-14. The TGA chart of the nanocomposite particle obtained in Examples 15-18. The TGA chart of the nanocomposite particle obtained in Examples 19-21. 20 is a TGA chart of nanocomposite particles obtained in Example 22. FIG. The TGA chart of the nanocomposite particle obtained in Examples 23-24. The TGA chart of the nanocomposite particle obtained in Examples 25-32. 18 is a UV-vis spectrum chart of the nanocomposite particles obtained in Example 17. FIG. The UV-vis spectrum chart of the nanocomposite particle obtained in Example 20. The UV-vis spectrum chart of the nanocomposite particle obtained in Example 22. The SEM photograph before and behind baking the nanocomposite particle obtained in Example 2 at 800 degreeC. (A) before firing, (b) after firing. The average particle diameter in the figure is a measured value obtained by SEM observation. The SEM photograph before and behind baking the nanocomposite particle obtained in Example 15 at 800 degreeC. (A) before firing, (b) after firing. The average particle diameter in the figure is a measured value obtained by SEM observation. The SEM photograph before and behind baking the nanocomposite particle obtained in Example 29 at 800 degreeC. (A) before firing, (b) after firing. The average particle diameter in the figure is a measured value obtained by SEM observation.

Hereinafter, the present invention will be described based on preferred embodiments thereof.
The perfluorocarbon sulfonic acid polymer-containing nanocomposite particles according to the first aspect of the present invention include (a) core silica particles having an average particle diameter of 5 to 200 nm, (b) alkoxysilane, (c) perfluorocarbon sulfonic acid polymer, and (D) Surface treatment of the core silica particles is carried out by adding 1 ml or more of ammonia water as NH ₃ to 1 ml of (b) alkoxysilane to the reaction raw material liquid containing the reaction solvent to hydrolyze the alkoxysilane. It is a nanocomposite particle obtained by performing the surface treatment process to perform.

The (a) core silica particles according to the surface treatment step of the first invention are silica particles having an average particle diameter of 5 to 200 nm. Examples of the core silica particle source related to the surface treatment step include silica sol containing silica particles having an average particle diameter of 5 to 200 nm. Examples of the silica sol containing the core silica according to the surface treatment step include hydrophilic solvent silica sol and hydrophobic silica sol. Methanol sol, ethanol sol, and isopropyl alcohol sol are preferable in terms of easy production of the sol. The methanol sol may be a commercially available product, and the hydrophobic solvent silica sol may be prepared by solvent replacement of the aqueous silica sol. Core silica particles in the silica sol, a silica particle made of SiO _2. The content of the core silica particles in the silica sol is not particularly limited, but is preferably 1 to 80% by weight, particularly preferably 2 to 50% by weight. For example, a reaction raw material liquid containing core silica having an average particle diameter of 5 to 200 nm can be obtained by adding silica sol containing core silica related to the surface treatment process to the reaction solvent related to the surface treatment process.

  As the silica source of the core silica particles according to the surface treatment step of the first invention, for example, those produced by particle growth from sodium silicate or active silicic acid solution, those produced using an organic silicon compound as a raw material, There is no particular limitation such as fumed silica.

  The average particle diameter of the core silica particles according to the surface treatment step of the first invention is 5 to 200 nm, preferably 5 to 50 nm. When the average particle diameter of the core silica particles is within the above range, the dispersibility of the silica composite particles in the dispersion solvent or the resin material is improved. On the other hand, when the average particle diameter of the core silica particles is less than 5 nm, it is difficult to produce and industrially obtain a silica sol containing the core silica particles, and when the average particle diameter exceeds 200 nm, the dispersion of the silica composite particles Stability is reduced. The core silica particles can be measured by a dynamic light scattering method. In the present invention, measurement was performed using DLS-6000HL manufactured by Otsuka Electronics.

  Examples of the (b) alkoxysilane according to the surface treatment step of the first invention include tetraalkoxysilanes such as tetramethoxysilane and tetraethoxysilane, alkyltrialkoxysilanes such as methyltrimethoxysilane and methyltriethoxysilane, and dimethyl. Examples thereof include dialkyl dialkoxysilanes such as dimethoxysilane and dimethyldiethoxysilane, and alkoxytrialkylsilanes such as hexyloxytrimethylsilane. The carbon chain length of the alkyl group in these alkoxysilanes is preferably 1-6. The carbon chain length of the alkoxy group is also preferably 1-6. Of these, tetraethoxysilane and tetramethoxysilane are preferable in terms of easy handling in production. Further, the alkoxysilane may be used alone or in combination of two or more.

The (c) perfluorocarbon sulfonic acid polymer according to the surface treatment step of the first invention is a polymer containing a C—F bond and no C—H bond in the polymer chain, and a sulfonic acid group (—SO ₃ H).
Specifically, Nafion (Nafion (registered trademark), manufactured by DuPont) represented by the following general formula (1) is preferable. In addition, Flemion (Flemion (registered trademark), manufactured by Asahi Glass), Aciplex (Aciplex ( Registered trademark), manufactured by Asahi Kasei Corporation, and the like.
(Wherein x and y are integers, usually x is 5 to 13.5, y is 1000. p is an integer of 0 to 3, q is 0 or 1, and n is an integer of 1 to 12, X represents a fluorine atom or a trifluoromethyl group.)

  As the (d) reaction solvent relating to the surface treatment step of the first invention, a solvent capable of dissolving (b) alkoxysilane and (c) perfluorocarbon sulfonic acid polymer relating to the surface treatment step is used. Examples of the reaction solvent related to the surface treatment step include lower alcohols such as methanol, ethanol and isopropyl alcohol. Among these, methanol is particularly preferable from the viewpoint of high reaction efficiency.

  In the surface treatment step of the first invention, when preparing the reaction raw material liquid, the order in which (a) silica sol containing core silica particles, (b) alkoxysilane, and (c) perfluorocarbon sulfonic acid polymer are mixed in the reaction solvent. Is not particularly limited.

  The content of the (a) core silica particles in the reaction raw material liquid according to the first invention is not particularly limited, but is preferably 1 to 80% by weight, particularly preferably 3 to 50% by weight. When the content of the core silica particles in the reaction raw material liquid is in the above range, the dispersion stability of the silica composite particles is increased.

  The content of (b) alkoxysilane in the reaction raw material liquid according to the first invention is 0.05 to 15 mmol, preferably 0.08 to 10 mmol, with respect to 1 g of (a) core silica particles. When the content of the alkoxysilane in the reaction raw material liquid is in the above range, the content of the (c) perfluorocarbon sulfonic acid polymer in the nanocomposite particles is increased. When the content of alkoxysilane in the reaction raw material liquid is less than 0.05 mmol with respect to 1 g of (a) core silica particles, the content of (c) perfluorocarbon sulfonic acid polymer in the nanocomposite particles tends to be low, On the other hand, if it exceeds 15 mmol, the dispersion stability of the nanocomposite particles tends to be low.

  In the first invention, the content of the (c) perfluorocarbon sulfonic acid polymer in the reaction raw material liquid is 0.01 g or more, preferably 0.05 to 100 g, particularly preferably with respect to 1 g of (a) core silica particles. 0.1 to 10 g. Since the content of the (c) perfluorocarbon sulfonic acid polymer in the reaction raw material liquid is in the above range, the content of the perfluorocarbon sulfonic acid polymer in the nanocomposite particles is increased, so that it has excellent proton conductivity. become. When the content of (c) perfluorocarbon sulfonic acid polymer contained in the reaction raw material liquid is less than 0.01 g with respect to 1 g of (a) core silica particles, the perfluorocarbon sulfonic acid polymer contained in the nanocomposite particles The content of is likely to be low.

In the surface treatment step according to the first invention, ammonia water is used as the alkali added to the reaction raw material liquid.
By using this aqueous ammonia, the nanocomposite particles of the present invention have excellent heat resistance despite containing organic substances.
The reason why the nanocomposite particles according to the present invention are excellent in heat resistance is that ammonia water serves as a catalyst in the sol-gel process, the deHF reaction proceeds smoothly from the perfluorocarbon sulfonic acid polymer, and the produced ammonium hexafluorosilicate is The present inventors presume that these compounds interact efficiently with the perfluorocarbon sulfonic acid polymer and impart heat resistance to these compounds.

In the first invention, the amount of ammonia water added to the reaction raw material solution is 1 ml or more, preferably 2 to 200 ml, with NH ₃ as NH ₃ with respect to 1 ml of (b) alkoxysilane. In the present invention, nanocomposite particles having heat resistance of 350 ° C. or more can be obtained by hydrolyzing (b) alkoxysilane with the aqueous ammonia used as the alkali in the above range.

  Moreover, the reaction temperature at the time of hydrolyzing alkoxysilane by mixing ammonia water with the reaction raw material solution which concerns on 1st invention is -5-50 degreeC, Preferably it is 0-30 degreeC. If the reaction temperature is less than −5 ° C., the hydrolysis rate of the alkoxysilane becomes too slow, so that the reaction efficiency is poor, and if it exceeds 50 ° C., the dispersion stability of the nanocomposite particles tends to be low. Further, the reaction time when the reaction raw material solution is mixed with aqueous ammonia to hydrolyze the alkoxysilane is not particularly limited and is appropriately selected, but is preferably 1 to 72 hours, and particularly preferably 1 to 72 hours. 24 hours.

  And the nanocomposite particle which concerns on 1st invention of this invention produces | generates by performing the surface treatment process of the core silica particle mentioned above, and the reaction liquid containing the nanocomposite particle which concerns on this invention is obtained.

  The reaction liquid containing the nanocomposite particles according to the first invention of the present invention is a suspension, and solid matter is observed in the reaction liquid by visual observation. Similarly, when the reaction solution is centrifuged at 3000 rpm for 30 minutes, the nanocomposite particles are precipitated as a solid.

  Therefore, in the present invention, as a method for recovering the nanocomposite particles from the reaction solution obtained by performing the surface treatment step, for example, the reaction solution is centrifuged at a centrifugal acceleration of 800 G for about 30 minutes to precipitate the target product. The nanocomposite particles according to the first invention of the present invention can be obtained by recovering as follows, washing if necessary, and then drying.

  In the nanocomposite particles according to the first invention of the present invention, the content of the perfluorocarbon sulfonic acid polymer is preferably 1 to 99% by weight, particularly preferably 5 to 80% by weight.

In the nanocomposite particles according to the first invention of the present invention, the content of SiO ₂ derived from the core silica particles is preferably 5 to 90% by weight, particularly preferably 10 to 80% by weight.

The nanocomposite particle according to the first invention of the present invention also includes a siloxane bond formed by hydrolysis of alkoxysilane in the surface treatment step. In the nanocomposite particle of the present invention, the content of Si atom derived from the siloxane bond formed by the hydrolysis of the alkoxysilane, in terms of SiO _2, preferably 1 wt% or more, particularly preferably at 5 to 99 wt% is there.

  In addition, as another preferable physical property of the nanocomposite particles according to the first invention of the present invention, the average particle size is preferably 10 to 950 nm, particularly preferably 50 to 900 nm. When the average particle size is within the above range, it is preferable in terms of good dispersibility in various dispersion solvents or resin materials.

  In the nanocomposite particles according to the second invention of the present invention, (e) a guest compound selected from aromatic compounds and fluorine-containing sulfonic acid compounds is further added to the reaction raw material liquid according to the first invention described above, It is a nanocomposite particle containing a perfluorocarbon sulfonic acid polymer and a guest compound obtained by hydrolyzing an alkoxysilane, and can further improve heat resistance as compared with the nanocomposite particle of the first invention.

  As an aromatic compound that can be used as the guest compound according to the second invention, a low molecular weight aromatic compound having a molecular weight of 2000 or less, preferably 50 to 1000, can convert the aromatic segment into the nanocomposite particles with a high yield. Since it can be introduced, it is preferably used.

  In the second invention, the aromatic compound may be monocyclic or condensed polycyclic. Moreover, the carbon atom of the benzene ring may be partially substituted with a nitrogen atom, and may further be quaternized. The aromatic compound may have a substituent. Although it does not restrict | limit especially as a kind of substituent, For example, a phenyl group, an alkyl group, a nitro group, an amino group, a hydroxyl group, a fluoro group, a chloro group, a bromo group, or an iodo group is mentioned.

In the second invention, preferred aromatic compounds are represented by, for example, the following general formulas (2) to (5).

X ¹ in the general formula (2) according to the second invention represents a halogen atom or a hydroxyl group, and n1 in the formula represents an integer of 0 to 3.
In the formula, R ⁶ , R ⁷ , R ⁸ and R ⁹ represent a group selected from the group consisting of a hydrogen atom, an alkyl group and an alkoxy group, and may be the same group or different groups. R ⁶ and R ⁷ , and R ⁸ and R ⁹ may be bonded to each other to form a saturated or unsaturated ring, and the saturated or unsaturated ring may have a substituent. . The alkyl group of R ⁶ , R ⁷ , R ⁸ and R ^{9 in} the general formula (2) is preferably an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group related to R ⁶ , R ⁷ , R ⁸ and R ⁹ include, for example, ethyl group, isopropyl group, n-propyl group, isobutyl group, n-butyl group, sec-butyl group, tert-butyl group, isoheptyl. Group, n-heptyl group, isohexyl group, n-hexyl group, cyclopentyl group, cyclohexyl group and the like.
In addition, when R ⁶ and R ⁷ or R ⁸ and R ⁹ are bonded to each other to form a saturated or unsaturated ring, R ⁶ and R ⁷ or R ⁸ and R ⁹ are bonded to each other. Examples of the ring include a saturated or unsaturated 5-membered ring or 6-membered ring, and examples thereof include a phenyl group, a cyclohexyl group, and a cyclopentyl group.
The ring formed by combining R ⁶ and R ⁷ or R ⁸ and R ⁹ may have a monovalent substituent, and R ⁶ and R ⁷ or R ⁸ and R ⁹ may be bonded to each other. Examples of the monovalent substituent that the ring formed as described above includes, for example, a linear or branched alkyl group having 1 to 5 carbon atoms, a nitro group, an amino group, a hydroxyl group, a fluoro group, A chloro group, a bromo group, and an iodo group are mentioned.
A in the general formula (2) represents a divalent linking group. As the divalent linking group, for example, an alkylene group having 1 to 20 carbon atoms, a phenylene group, or a group containing nitrogen is preferable. In the alkylene group or phenylene group, a hydrogen atom may be substituted with a halogen atom. . N2 in the formula represents an integer of 0 or 1.

R ¹⁰ in the general formula (3) according to the second invention is preferably an alkyl group having 1 to 20 carbon atoms or an alkoxy group. X ² in the general formula (3) is preferably a hydroxyl group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. In the alkoxy group and alkyl group of R ¹⁰ and X ² , a hydrogen atom may be substituted with a halogen atom. N3 in a formula shows the integer of 0-4. Y in the formula represents an anionic group, and the anionic group is particularly preferably a halogen atom.

R ¹¹ in the general formula (4) according to the second invention is preferably an alkyl group having 1 to 20 carbon atoms or an alkoxy group. R ¹¹ is preferably an alkyl group having 1 to 20 carbon atoms or an alkoxy group. In the alkyl group and alkoxy group, a hydrogen atom may be substituted with a halogen atom. X ³ represents a hydroxyl group or a halogen atom. N4 in a formula shows the integer of 0-2.

R ¹² in the general formula (5) according to the second invention is preferably a hydroxyl group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. In the alkoxy group and the alkyl group, a hydrogen atom may be substituted with a halogen atom. N5 in a formula shows the integer of 0-4.

  In the second invention of the present invention, particularly preferred low molecular weight aromatic compounds are 1,1-bi-2-naphthol (molecular weight; 286), 4,4′-biphenol (molecular weight; 186), bisphenol A (molecular weight). 228), bisphenol AF (molecular weight; 336), cetylpyridinium chloride (molecular weight; 340), biphenyl (molecular weight; 154), cresol (molecular weight; 108), chlorhexidine (molecular weight; 505) and 1,1′-binaphthalene-2 2,2'-diol 2,2'-phosphoric acid (molecular weight; 364).

  In the second invention, as the fluorine-containing sulfonic acid compound that can be used as the guest compound, perfluoroalkane disulfonic acid or a fluoroalkyl group-containing sulfonic acid oligomer is preferably used.

In the second invention, the perfluoroalkanedisulfonic acid represented by the following general formula (6) is preferably used.
(In the formula, m represents an integer of 1 to 12.)
Preferred compounds of perfluoroalkane disulfonic acid include difluoromethane disulfonic acid, perfluoroethane disulfonic acid, perfluoropropane disulfonic acid, perfluorobutane disulfonic acid, perfluorooctane disulfonic acid, and the like.

In the second invention, as the fluoroalkyl group-containing sulfonic acid oligomer, those represented by the following general formula (7) are preferably used.
(Wherein, _{R F is, - (CF 2) p-} Y group, or _{-CF (CF 3) - [OCF} 2 CF (CF 3)] indicates the _q-OC 3 _{F 7} group, wherein the _{R F} Y represents a hydrogen atom, a fluorine atom or a chlorine atom, p and q are integers of 0 to 10. R ′ represents a hydrogen atom or a methyl group, and n6 represents an integer of 5 to 1000.)

  The fluoroalkyl group-containing oligomer represented by the general formula (7) according to the second invention is a known substance. For example, JP 2007-270124 A, JP 2009-209349 A, and JP 2005-2005 A. It can be produced by referring to the methods described in JP-A-71694, JP-A No. 2003-257240 and the like.

  In the second invention, (e) a guest compound selected from an aromatic compound and a fluorine-containing sulfonic acid compound is bisphenol AF, 1,1′-bi-2-naphthol, 1,1′-binaphthalene-2,2′- Diol 2,2′-phosphoric acid, perfluoroalkanedisulfonic acid, and fluoroalkyl group-containing sulfonic acid oligomer are particularly preferably used.

  The guest compound selected from (e) an aromatic compound and a fluorine-containing sulfonic acid compound in the reaction raw material liquid according to the second invention (hereinafter sometimes simply referred to as “guest compound (e)”) is (a) core silica. It is 0.01g or more with respect to 1g of particle | grains, Preferably it is 0.05-100g, Most preferably, it is 0.1-10g. When the guest compound (e) in the reaction raw material liquid is in the above range, the heat resistance of the perfluorocarbon sulfonic acid polymer-containing nanocomposite particles can be further improved.

The reaction conditions relating to the surface treatment process of the nanocomposite particles of the second invention of the present invention may be performed in accordance with the surface treatment process of the nanocomposite of the first invention described above.
In the surface treatment step according to the second aspect of the present invention, the preferable range of the amount of ammonia water added is 1 ml or more, preferably 2 to 200 ml with NH ₃ as NH ₃ with respect to 1 ml of alkoxysilane (b). Satisfactory nanocomposite particles are obtained.

  In the nanocomposite particles according to the second invention of the present invention, the content of the guest compound (e) is preferably 1 to 80% by weight, particularly preferably 5 to 70% by weight.

  In the nanocomposite particles according to the second invention of the present invention, the content of the perfluorocarbon sulfonic acid polymer is preferably 1 to 90% by weight, particularly preferably 5 to 80% by weight.

In the nanocomposite particles according to the second invention of the present invention, the content of SiO ₂ derived from the core silica particles is preferably 5 to 90% by weight, particularly preferably 10 to 80% by weight.

In the nanocomposite particles according to the second invention of the present invention, the content of Si atoms formed by hydrolysis of alkoxylane and derived from siloxane bonds is preferably 1% by weight or more, particularly preferably in terms of SiO _2. Is from 5 to 99% by weight.

  In addition, as another preferable physical property of the nanocomposite particles according to the second invention of the present invention, the average particle size is preferably 10 to 950 nm, particularly preferably 50 to 900 nm. When the average particle size is within the above range, it is preferable in terms of good dispersibility in various dispersion solvents or resin materials.

  The nanocomposite particle dispersion of the present invention is a dispersion in which the nanocomposite particles of the first invention and the second invention of the present invention are dispersed in a dispersion solvent.

  The nanocomposite particles of the present invention exhibit high dispersibility in various dispersion solvents. Therefore, in the dispersion obtained by dispersing the nanocomposite particles of the present invention in a dispersion solvent, that is, in the nanocomposite particle dispersion of the present invention, the nanocomposite particles are dispersed without agglomeration. Is not observed.

  The dispersion solvent according to the nanocomposite particle dispersion of the present invention is not particularly limited as long as it is inert to the nanocomposite particles of the present invention and can be uniformly dispersed, and may be either water or an organic solvent, As the organic solvent, either a polar organic solvent or a nonpolar organic solvent may be used. Examples of the organic solvent according to the nanocomposite particle dispersion of the present invention include methanol, ethanol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide and the like.

  In the nanocomposite particle dispersion of the present invention, the concentration of the nanocomposite particles is not particularly limited as long as it is appropriately adjusted in consideration of the application and usage method, and in many cases, 0.1 to 90% by weight. It is.

The nanocomposite particles according to the first invention of the present invention have a 10 wt% thermogravimetric decrease temperature of 350 to 470 ° C, preferably 350 to 450 ° C, and Nafion alone (10 wt% decrease temperature; 305 ° C). Compared to, the heat resistance is improved.
In addition, the nanocomposite particles according to the second invention of the present invention have a small weight loss rate even when fired at 800 ° C., and there is little change in composition after the firing treatment, despite being an organic material. It has the characteristics.
Furthermore, the nanocomposite particles according to the first and second inventions of the present invention have high proton conductivity even after firing at 800 ° C., and the proton conductivity after firing is before firing. It has a very unique property of improving.
Therefore, nanocomposite particles having such characteristics can be suitably used as a resin composition used in a field where heat resistance is required, for example, by being contained as a resin composition.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. Unless otherwise specified, “%” means “% by weight”.

(Preparation of fluoroalkyl group-containing oligomer)
(Synthesis Example 1)
A 1 L three-necked flask was charged with 500 ml of 2-methacryloxyethanesulfonic acid (MES) (0.41 mol) and AK-225, and at room temperature, perfluoro-2-methyl-3-oxahexanoyl peroxide ( 334 g (perfluoro-2-methyl-3-oxahexanoyl peroxide 0.05 mol) of a 10% AK-225 solution of [C ₃ F ₇ —O—CF (CF ₃ ) —CO—O—] ₂ ) was charged. Then, it heated up to 45 degreeC, stirring, after aging for 5 hours, stirring was stopped and it left still overnight. After standing, it was concentrated, washed with AK-225, filtered, and vacuum dried at 50 ° C. to obtain an oligomer abbreviation represented by the above general formula (A); RF-MES oligomer). The number average molecular weight determined by gel permeation chromatography (GPC, converted to polyethylene glycol) was 12,000.

{Examples 1-14}
In a sample bottle, 10 ml of methanol was added, and then Nafion (registered trademark), 0.50 g of silica sol (the content of SiO ₂ was 0.15 g), and tetraethoxysilane were added in the amounts shown in Table 1, and mixed with stirring. Next, 25% aqueous ammonia was added with sufficient stirring, and the mixture was stirred at 25 ° C. for 5 hours and then concentrated. After concentration, methanol was added to the solid content and stirred overnight to disperse the solid content, followed by centrifugation. The obtained solid content was added to methanol, dispersed overnight, and then subjected to centrifugation twice for purification. The purified solid was vacuum dried in a vacuum desiccator to obtain silica composite particles.
Silica sol: (30% methanol solution, manufactured by Nissan Chemical Industries, particle size 10-20 nm)

<Physical property evaluation 1>
For the nanocomposite particle sample, the average particle diameter, 10 wt% thermal weight reduction temperature, and weight reduction rate at 800 ° C. were measured.
(Evaluation of average particle size)
In addition to methanol, the nanocomposite particle sample was stirred for 24 hours, dispersed in methanol, and fired from room temperature to 800 ° C. at a rate of 10 ° C./min using a light scattering photometer, and firing The average particle size of the previous sample was measured.
(Evaluation of 10% by weight thermal weight reduction temperature)
The nanocomposite particle sample was determined by thermogravimetric analysis.
(Evaluation of weight loss rate at 800 ° C)
The nanocomposite particle sample was determined by thermogravimetric analysis. In addition, a TGA curve is shown in FIG. 1 (Examples 1-4), FIG. 2 (Examples 5-11), and FIG. 3 (Examples 12-14). In addition, TGA curves of silica sol alone, Nafion (registered trademark) alone, and mixture a (Nafion: SiO ₂ = 1: 5 (weight ratio)) are also shown.

Note) "-" in the table indicates unmeasured.

{Examples 15 to 22}
In a sample bottle, 10 ml of methanol was added, and then Nafion (registered trademark), 0.50 g of silica sol (the content of SiO ₂ was 0.15 g), tetraethoxysilane, and bisphenol AF (guest compound) in the amounts shown in Table 3. Hereinafter referred to as “BPAF”), (±) -1,1′-B 2-naphthol (hereinafter referred to as “BINOL”) or (±) -1,1′-binaphthalene-2,2′-diol 2 , 2′-phosphoric acid (hereinafter referred to as “BINOL-POH”) was added and mixed with stirring. Next, 25% aqueous ammonia was added with sufficient stirring, and the mixture was stirred at 25 ° C. for 5 hours and then concentrated. After concentration, methanol was added to the solid content and stirred overnight to disperse the solid content, followed by centrifugation. The obtained solid content was added to methanol, dispersed overnight, and then subjected to centrifugation twice for purification. The solid content after purification was vacuum dried in a vacuum desiccator to obtain nanocomposite particles.
Silica sol: (30% methanol solution, manufactured by Nissan Chemical Industries, particle size 10-20 nm)

<Physical property evaluation 2>
For the nanocomposite particle sample, the average particle diameter and the weight reduction rate at 800 ° C. were measured in the same manner as in the physical property evaluation 1.
TGA curves are shown in FIG. 4 (Examples 15 to 18), FIG. 5 (Examples 19 to 21), and FIG. 5 (Example 22). Further, Nafion (registered trademark) alone, BPAF alone, BINOL alone, BINOL-POH alone, mixture A (Nafion: SiO ₂ : BPAF = 1: 6: 3 (weight ratio)), mixture B (Nafion: SiO ₂ : BINOL) A TGA curve of -POH = 1: 6: 3 (weight ratio) was also shown.

{Examples 23 to 32}
In a sample bottle, 10 ml of methanol was added, and then Nafion (registered trademark), silica sol 0.50 g (content of SiO ₂ was 0.15 g), tetraethoxysilane, and guest compound in the amounts shown in Table 5 were RF-MES. An oligomer or perfluoro-1,3-propanedisulfonic acid (hereinafter referred to as “PFPS”) was added and mixed with stirring. Next, 25% aqueous ammonia was added with sufficient stirring, and the mixture was stirred at 25 ° C. for 5 hours and then concentrated. After concentration, methanol was added to the solid content and stirred overnight to disperse the solid content, followed by centrifugation. The obtained solid content was added to methanol, dispersed overnight, and then subjected to centrifugation twice for purification. The solid content after purification was vacuum dried in a vacuum desiccator to obtain nanocomposite particles.
Silica sol: (30% methanol solution, manufactured by Nissan Chemical Industries, particle size 10-20 nm)

<Physical property evaluation 3>
For the nanocomposite particle sample, the average particle diameter and the weight loss rate at 800 ° C. were measured in the same manner as in Physical Property Evaluation 1 and Physical Property Evaluation 2.
TGA curves are shown in FIG. 7 (Examples 23 to 24) and FIG. 8 (Examples 25 to 32). In addition, TGA curves of Nafion (registered trademark) alone, RF-MES oligomer alone, and mixture C (Nafion: SiO ₂ : RF-MES oligomer = 1: 6: 3 (weight ratio)) are also shown.

<Physical property evaluation 4>
(Measurement of UV-vis spectrum before and after firing)
About the nanocomposite particles obtained in Example 17, Example 20, and Example 22, UV-vis spectra in a methanol solution of a sample fired at 800 ° C. and a sample before baking are shown in FIG. 9, FIG. 10, and FIG. Respectively.
In addition, UV-vis spectra of BPAF alone, BINOL alone, and BINOL-POH alone are also shown.

(SEM observation and elemental analysis before and after firing)
The nanocomposite particles obtained in Example 2, Example 15 and Example 29 were subjected to SEM observation before and after firing at 800 ° C., and SEM photographs before and after firing are shown in FIG. 12, FIG. 13 and FIG.
Further, the nanocomposite particles obtained in Example 2, Example 15 and Example 29 were subjected to elemental analysis by EDX before and after firing at 800 ° C., and the results are shown in Table 7.

From the results of the UV-vis spectral analysis of FIGS. 9 to 11, before calcination, respective spectral peaks caused by BPAF, BINOL, and BINOL-POH were observed. From the elemental analysis of Table 7, Nafion (registered) Since the elements of F and S derived from the trademark are observed, the nanocomposite particles before firing contain Nafion (registered trademark) in addition to PFPS, BINOL, and BINOL-POH. I understand.
Further, after the baking treatment at 800 ° C., clear UV-vis spectra of BPAF, BINOL, and BINOL-POH are not observed from the results of FIGS. Although it has changed, since it has almost the same elemental composition as before firing, it is considered that the nanocomposite particles after firing contain Nafion (registered trademark) in addition to BPAF, BINOL-POH and PFPS. . The UV-vis spectrum is not observed after the baking process at 800 ° C., because the guest compounds such as BPAF, BINOL, and BINOL-POH are strongly encapsulated in the silica matrix in the composite, so that the guest compounds are hardly released. The present inventor speculates that this is because it has become.

(Evaluation of dispersibility)
The dispersibility of the nanocomposite particles obtained in Examples 13 and 27 with respect to various dispersion solvents was tested. The results are shown in Table 8. In addition, 0.01 g of nanocomposite particles were added to 5 ml of the evaluation dispersion solvent, and the dispersion state was visually observed and evaluated.
○: Good dispersion △; Partial dispersion ×: Almost no dispersion

Note) IPA; isopropyl alcohol, DMSO; dimethyl sulfoxide, DMF; dimethylformamide, DE: 1,2-dichloromethane, THF; tetrahydrofuran, AK-225; 1 by weight ratio of CF ₃ CF ₂ CHCl ₂ and CClF ₂ CF ₂ CHClF : 1 mixed solution

(Evaluation of proton conductivity and zeta potential)
For the nanocomposite particles obtained in Example 9 and Example 29, each nanocomposite particle before and after firing at 800 ° C. was dispersed in water to prepare a 5 g / L dispersion sample. Using this dispersion, proton conductivity at 25 ° C. was measured by (HORIBA Desk Electrical Conductor DS 71). The results are shown in Table 9. In addition, those measured with Nafion (registered trademark) alone are also shown.
In addition, a dispersion of 0.01 g / L was prepared, and the zeta potential was measured using Microtec Region ZEECOM / ZC-2000. The results are also shown in Table 9. In addition, those measured with Nafion (registered trademark) alone are also shown.

From the results of Table 9, the nanocomposite particles of the present invention have excellent proton conductivity, and the proton conductivity after firing at 800 ° C. is higher than that before firing. This is thought to be because the zeta potential after firing was charged on the negative side compared to the zeta potential before firing, and many sulfo groups of Nafion (registered trademark) appeared on the nanocomposite particle surface after firing.

  According to the present invention, nanocomposite particles containing a perfluorocarbon sulfonic acid polymer, having excellent proton conductivity, and having heat resistance of 350 ° C. or higher can be provided. . Moreover, according to the present invention, the nanocomposite particles can be provided by an industrially advantageous method.

Claims (9)

A reaction raw material liquid containing (a) core silica particles having an average particle diameter of 5 to 200 nm, (b) alkoxysilane, (c) perfluorocarbon sulfonic acid polymer, and (d) a reaction solvent. Then, by adding 1 ml or more of aqueous ammonia as NH ₃ and hydrolyzing the alkoxysilane, a surface treatment step for treating the surface of the core silica particles can be performed, and the nanofiber containing a perfluorocarbon sulfonic acid polymer is obtained. Composite particles.   The perfluorocarbon sulfonic acid polymer-containing nanocomposite particles according to claim 1, wherein the perfluorocarbon sulfonic acid polymer is Nafion (registered trademark).   3. The perfluorocarbon sulfonic acid polymer-containing nanocomposite particles according to claim 1 or 2, wherein the average particle size is 10 to 950 nm.   (E) a surface treatment step of performing a surface treatment of the core silica particles by further mixing (e) a guest compound selected from an aromatic compound and a fluorine-containing sulfonic acid compound and hydrolyzing the alkoxysilane. 4. The perfluorocarbon sulfonic acid polymer-containing nanocomposite particle according to claim 1, wherein the nanocomposite particle is obtained.   5. The aromatic compound is selected from bisphenol AF, 1,1′-bi-2-naphthol, 1,1′-binaphthalene-2,2′-diol 2,2′-phosphate. Perfluorocarbon sulfonic acid polymer-containing nanocomposite particles.   The perfluorocarbon sulfonic acid polymer-containing nanocomposite particles according to claim 4, wherein the fluorinated sulfonic acid compound is selected from perfluoroalkanedisulfonic acid and fluoroalkyl group-containing sulfonic acid oligomers. A reaction raw material liquid containing (a) core silica particles having an average particle diameter of 5 to 200 nm, (b) alkoxysilane, (c) perfluorocarbon sulfonic acid polymer, and (d) a reaction solvent. A perfluorocarbon sulfonic acid polymer-containing nanocomposite characterized by having a surface treatment step of adding 1 ml or more of aqueous ammonia as NH ₃ to hydrolyze the alkoxysilane to surface-treat the core silica particles Particle production method.   (E) a surface treatment step in which a guest compound selected from an aromatic compound and a fluorine-containing sulfonic acid compound is further mixed with the reaction raw material liquid, the alkoxysilane is hydrolyzed, and the surface treatment of the core silica particles is performed. The method for producing perfluorocarbon sulfonic acid polymer-containing nanocomposite particles according to claim 7, comprising:   A nanocomposite particle dispersion comprising the perfluorocarbonsulfonic acid polymer-containing nanocomposite particles according to any one of claims 1 to 6.