JP6941829B2 - Vanadium dioxide particle-containing composition - Google Patents

Description

The present invention relates to novel and useful vanadium dioxide particle-containing compositions.

Conventionally, films and glasses for heat ray cutting have been developed, and in recent years, dimming films and dimming glasses having a thermochromic function have been developed. Particularly recently, substituted vanadium dioxide in which a part of vanadium atom of vanadium dioxide or vanadium dioxide is replaced with another atom is promising as a material having a heat ray cutting function based on a thermochromic function. (Patent Document 1, Patent Document 2, etc.).
Since ITO and ATO, which are used as heat ray cutting materials for conventional windows, always cut IR, the room is cool in summer but cold in winter. On the other hand, vanadium dioxide has a thermochromic property in which the IR cut rate changes depending on the temperature. Because it has, it is regarded as promising.

The production of films and glasses using these vanadium dioxide materials is roughly classified into a dry method and a wet method. The dry method is a method of forming a thin film by depositing a vanadium dioxide-based material on a substrate by means such as sputtering (Patent Document 3, Patent Document 4, etc.).

In the wet method, vanadium-containing materials such as vanadium pentoxide and vanadium trioxide are used as raw materials, and vanadium dioxide fine particles are produced by a reaction in a solid phase or a reaction under water heat, and components such as a binder are added as necessary. This is a method in which the coating liquid is added and applied onto a substrate to form a coating film. From the viewpoint of the transparency and photochromic property of the coating film, the vanadium dioxide particles are preferably fine. As a method for producing fine vanadium dioxide particles, a method of crushing coarse particles generated by a solid phase reaction (Patent Document 2, Patent Document 5, Patent Document 6, Patent Document 7, Patent Document 8, Patent Document 9, Patent Document 2). Document 10, Patent Document 11 Patent Document 12, Patent Document 13, Patent Document 14, Patent Document 15, Patent Document 16, Patent Document 17, Patent Document 18, Patent Document 19, Patent Document 20) There is a method of precipitating particles, taking them out, and redispersing them in a liquid by ultrasonic waves or the like (Patent Document 21, Patent Document 22, Patent Document 23, Patent Document 24, Patent Document 25).

Japanese Unexamined Patent Publication No. 2000-233929 Japanese Unexamined Patent Publication No. 2012-025629 Japanese Unexamined Patent Publication No. 1995-331430 Japanese Unexamined Patent Publication No. 2016-088827 Japanese Unexamined Patent Publication No. 2012-025630 Japanese Unexamined Patent Publication No. 2012-072309 Japanese Unexamined Patent Publication No. 2012-206878 Japanese Unexamined Patent Publication No. 2012-250879 Japanese Unexamined Patent Publication No. 2013-075806 Japanese Unexamined Patent Publication No. 2014-094881 JP-A-2015-063453 JP-A-2015-063454 JP-A-2015-164892 Japanese Unexamined Patent Publication No. 2001-136873 Japanese Unexamined Patent Publication No. 2012-141353 Japanese Unexamined Patent Publication No. 2012-140754 Japanese Unexamined Patent Publication No. 2012-140753 Japanese Unexamined Patent Publication No. 2014-505651 JP-A-2015-513508 Japanese Unexamined Patent Publication No. 2000-233929 Japanese Unexamined Patent Publication No. 2016-188939 Japanese Unexamined Patent Publication No. 2016-075729 Japanese Unexamined Patent Publication No. 2016-190938 Japanese Unexamined Patent Publication No. 2016-191015 Japanese Unexamined Patent Publication No. 2016-191016

However, among these methods, the dry method is expensive and difficult to increase the area. Further, since the production requires heating of several hundred degrees, there is a problem that it can be used only for a base material having heat resistance such as glass.

Further, in the wet method, it is generally difficult to make vanadium dioxide particles into fine particles, and even if they are made fine, it is easy to reaggregate and it is difficult to obtain a stable dispersion of fine particles, so that high transparency cannot be obtained. It was found by the examination of the present inventors that there was a problem. According to the studies by the present inventors, it has been found that even if a general dispersant used for other oxide fine particles is used, a stable dispersion cannot be obtained and reaggregates.

This is because the coarse particles of vanadium dioxide are not aggregated primary particles, but are large primary particles themselves, so a large share must be applied to finely disperse them, and they are crushed by applying a large share. It is considered that the crushed surface thus formed is active and easily reaggregates. Further, since vanadium dioxide has a smaller difference in electronegativity between a metal atom and an oxygen atom than titanium oxide, zirconium oxide, or the like, it is considered that the charge polarization is small. Therefore, it is speculated that the affinity with the dispersant may be low. Therefore, it is presumed that the stability of the particles obtained by hydrothermal synthesis is the same.

Furthermore, the hydrothermal synthesis method generally requires a device that can withstand high temperature and high pressure, which has the disadvantage of high manufacturing cost and the disadvantage of requiring a process such as solvent replacement in order to mix with other components such as resin. ..
Furthermore, since the concentration of vanadium dioxide is as low as 10% by weight or less in both the pulverization method and the hydrothermal synthesis method, it is difficult to impart high thermochromic property and heat shielding property to glass and film, and it is practically used. Becomes a wall. This is because hydrothermal synthesis is restricted by the reaction conditions, but it is also presumed that the particle surface is active and easily aggregates regardless of the hydrothermal synthesis method or the crushing method.

Therefore, the present inventors have conducted diligent studies in order to solve the above problems. As a result, they have found that these problems can be solved by the following vanadium dioxide particle-containing dispersion, and have reached the present invention.

That is, the present invention
(1) A vanadium dioxide particle-containing composition containing vanadium dioxide particles, a dispersion medium, a polyether-based dispersant, and a silane coupling agent.
(2) The vanadium dioxide particle-containing composition according to claim 1, wherein the polyether-based dispersant is a polyethylene oxide-based dispersant or a polypropylene oxide-based dispersant.
(3) The vanadium dioxide particle-containing composition according to (1) or (2) above, wherein the polyether-based dispersant is an amine-based dispersant.
(4) The vanadium dioxide particle-containing composition according to any one of (1) to (3) above, wherein the silane cup linking agent has a double bond.

(5) The vanadium dioxide particle-containing composition according to any one of (1) to (4) above, wherein the silane cup linking agent has an energy of 0 to 2.5 eV in the lowest empty orbit.
(6) The vanadium dioxide particle-containing composition according to any one of (1) to (5) above, wherein the silane cup linking agent has an energy difference between the highest occupied orbital and the lowest empty orbital of 11.5 eV or less.
(7) The vanadium dioxide particle-containing composition according to any one of (1) to (6) above, wherein the silane cup linking agent has an energy difference of 0.05 au or less between the anion and the neutral molecule, (8) silane. The vanadium dioxide particle-containing composition according to any one of (1) to (7) above, wherein the coupling agent has at least one of a methacryl group and an acrylic group.
(9) The vanadium dioxide particle-containing composition according to any one of (1) to (8) above, wherein the content of the silane coupling agent is 5 to 100 parts by weight with respect to 100 parts by weight of vanadium dioxide.

(10) The vanadium dioxide particle-containing composition according to any one of (1) to (9) above, wherein the content of the dispersant is 5 to 100 parts by weight with respect to 100 parts by weight of vanadium dioxide.
(11) The vanadium dioxide particle-containing composition according to (1) to (10) above, wherein the content of vanadium dioxide particles is 5 to 50% by weight and the viscosity is 5 mPa · s or less.
(12) The vanadium dioxide particle composition according to any one of (1) to (11) above is mixed with a binder resin to prepare a coating liquid, which is applied to a transparent substrate and cured. Manufacturing method of vanadium-containing thermochromic substrate,
(13) The vanadium dioxide particle composition according to any one of (1) to (11) above is mixed with a binder resin to prepare a coating liquid, which is applied to a transparent substrate and cured. Manufacturing method of vanadium-containing heat ray cutting material,
(14) A method for producing a heat-shielding film, which comprises mixing the vanadium dioxide particle composition according to any one of (1) to (11) above with a thermoplastic polymer and stretching the obtained masterbatch. ,It is in.

According to the present invention, it is possible to obtain a fine and stable vanadium dioxide particle dispersion, and it is possible to form a coating film having low haze, excellent transparency, and excellent thermochromic properties.

1. 1. Vanadium dioxide particles The vanadium dioxide particles contained in the vanadium dioxide particle-containing composition of the present invention are not particularly limited, and the chemical composition of vanadium dioxide may contain various doping components in addition to _{pure VO 2.} For example, doped with tungsten, molybdenum, niobium, tantalum, chromium, iron, gallium, aluminum, fluorine, phosphorus and the like as described in Japanese Patent Application Laid-Open No. 2004-346260, Japanese Patent Application Laid-Open No. 2016-29000, etc. It may be used as an ingredient.

The method for producing vanadium dioxide particles is also not particularly limited. For example, the method described in Nippon Denko Patent 5902361 or the method by hydrothermal synthesis may be used.
Although the particle size of the crude vanadium dioxide particles obtained by the above various methods is relatively large,
By slurrying by the method described later, the particle size can be adjusted to the following preferable range.

According to the present invention, fine vanadium dioxide particles having a particle size distribution of 200 nm or less and further 150 nm or less can be obtained. Therefore, the haze is low and high transparency can be obtained. This is considered to be due to the following reasons.
Since particles of 200 nm or less are in the Rayleigh scattering region, light scattering in the visible light region (400 nm to 780 nm) due to geometric scattering or Mie scattering is reduced. In the Rayleigh scattering region, the scattered light decreases in inverse proportion to the sixth power of the particle size, so that the scattered light decreases as the particle size decreases, and the transparency is improved. Further, when the particle size is 150 nm or less, the scattered light is very small, so that a film having low haze and high transparency can be obtained even when it is used as a coating film.

Further, from the results of studies by the present inventors, it was found that the haze can be lowered by suppressing the content of particles having a diameter of 100 nm or more.

The particle size and particle size distribution of the vanadium dioxide particles are not particularly limited, but the particle size distribution is preferably 10 nm to 500 nm, particularly preferably 20 nm to 200 nm, still more preferably 30 nm to 150 nm, and most preferably 30 to 100 nm.
Within the above range, the haze of the vanadium dioxide-containing coating film, which will be described later, can be lowered, and the excellent effect of improving the transparency can be obtained.

The particle size is preferably 38 nm or less for D10, 55 nm or less for D50, 80 nm or less for D90, and 7% or less for particles of 100 nm or more. Within this range, the haze of the obtained coating film can be 2% or less. More preferably, the particle ratio of D10: 37 nm or less, D50: 53 nm or less, D90: 77 nm or less, 100 nm or more: 5% or less. Within this range, the haze can be set to 1% or less.
In the present invention, it is possible to further obtain a particle size having a D10 of 34 nm or less, a D50 of 50 nm or less, and a D90 of 64 nm or less. However, even if it is made too small, it becomes ultrafine particles and reaggregation is likely to occur. Therefore, D10 can be preferably 10 nm or more, more preferably 20 nm or more.

The above particle size distribution and particle size measurement method is based on the dynamic light scattering method. More specifically, it can be obtained by a frequency matrix analysis method (Microtrack UPA-EX150 Nikkiso Co., Ltd.) that converts the frequency characteristics generated when a Brownian motion particle is irradiated with laser light into a particle size distribution.
The above vanadium dioxide particles are preferably used in the form of a slurry.
The slurry contains the following components in addition to the vanadium dioxide particles.

2. Polyether-based dispersant The present invention is characterized in that the composition containing vanadium dioxide particles contains a polyether-based dispersant.
A polyether-based dispersant is a substance composed of a chain polymer having an ether bond (-COC-) as a main chain, and has a function of stabilizing vanadium dioxide particles, which are solid fine particles, in a liquid medium. .. The dispersant is contained in a surfactant in a broad sense, and has a hydrophilic group and a hydrophobic group to stabilize fine particles in a liquid medium.

Particularly preferred is an amine-based polyether-based dispersant. Amine-based polyether dispersants are primary amines (RNH ₂ ), secondary amines (R ₂ NH), tertiary amines (R ₃ N) or quaternary amines (R ₁ ) (R _2). ) N ⁺ (R ₃ ) (R ₄ ) Substituent Rn means that one or more of them contain a polyether.
For example, various alkylene oxides such as ethylene oxide (EO) or propylene oxide (PO) are ring-opened in various amines such as alkylamine, alkenylamine, alkylhydroxylamine, alkenylhydroxylamine, oxyalkylamine, and oxyalkenylamine. The added ones can be mentioned.

More specifically, the suitable dispersant that can be used in the present invention is represented by the following chemical formula.
[Chemical formula 1]

In the formula, R1, R2 and R3 are one or more groups selected from a hydrogen atom, a hydroxyl group, an alkyl group, an alkenyl group, a phenyl group, an acrylic group, a vinyl group, a methacryl group, a styryl group and a heterocycle, and are the same. But it may be different.
A functional group having no double bond is preferable, and a hydrogen atom, an alkyl group or an alkenyl group is preferable, a hydrogen atom or an alkyl group is particularly preferable, and a hydrogen atom or an alkyl group having 1 to 10 carbon atoms is more preferable. Is an alkyl group having 1 to 5 carbon atoms, and particularly preferably an alkyl group having 1 or 2 carbon atoms.

X is a polyether moiety. The polyether portion in the present invention is a portion in which a plurality of ether bonds are connected. R and R'forming the ether bond (RO-R') consist of one or more of an aryl group or an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms, and more preferably 1 to 1 carbon atom. An alkyl group of 5, particularly preferably an alkyl group having 1 or 2 carbon atoms. Both R and R'are not limited to one type. Further, the polyether moiety may be either linear or branched, and may be a combination thereof.

Particularly preferred Xs are:
[Chemical formula 2]

In the formula, R4, R5 and R6 are composed of one or more of an aryl group or an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably. Is an alkyl group having 1 or 2 carbon atoms. Further, it may be either linear or branched, and may be a combination thereof.
In the formula, x, y and z are integers, preferably x is 1 to 200, more preferably 40 to 80, and particularly preferably 50 to 90. Y is preferably 1 to 400, more preferably 50 to 200, and particularly preferably 90 to 140. The ratio of x to y is 1 to 0.5 to 1 to 5.0 for x to y, particularly preferably 1.0 to 0.8 to 1.0 to 3.0, and most preferably 1.0 to 1. 5 to 1.0 to 2.5.
z is preferably 0 to 100, particularly preferably 0 to 50, and even more preferably 0 to 10.

The hydrophobicity of the dispersant can be adjusted by the structures of R5 and R6 and the ratio of x and y. If the difference in the degree of hydrophobicity between the dispersant and the solvent is small, the affinity with the solvent is excellent. Therefore, the ratio of x and y can be adjusted to increase the affinity with the solvent, and the stability of the dispersion liquid can be improved. Is expected to improve. In particular, since it is considered that the polyether moiety described above contributes to the affinity with the solvent, the affinity of this moiety may be adjusted.
It is convenient and effective to use an index such as a logP SP value for the degree of affinity with a solvent. Among them, LogP is more convenient because it can be obtained by general chemical calculation from the molecular structure.
When two immiscible liquids are placed in the same container, a third substance is added and shaken well, the ratio of concentrations in both liquids becomes constant regardless of the amount initially added. The concentration ratio at this time is called the partition coefficient (LogP) of the target substance.
In the case of LogP, the difference between the LogP of the polyether moiety and the LogP of the solvent described above is 2.0 or less, preferably 1.5 or less, and more preferably 0.5 or less.

The most preferred R5 and R6 are alkyl groups having 2 or 3 carbon atoms. That is, it contains one or more repeating units of (Et-O) n and (Pr-O) n', which are generally called polyethylene oxide and polypropylene oxide.

A particularly preferable X is represented by the following formula.
[Chemical formula 3]

In the formula, xyz is as described above.

Further, the (Et-O) unit and the (Pr-O) unit may be linearly connected, may be branched, or may be a combination thereof.

The molecular weight of the dispersant described above is 500 to 50,000, particularly preferably 500 to 30,000, and even more preferably 15,000 to 25,000 in terms of weight average molecular weight. In this range, the effect of suppressing aggregation of particles is particularly good, and the dispersibility and dispersion stability are excellent. It is considered that this is due to the adsorptivity of the dispersant to the particles and steric hindrance.
The molecular weight referred to here refers to the weight average molecular weight (Mw) in terms of standard polystyrene by GPC (gel permeation chromatography). The dispersant is dissolved in a solvent, passed through a column in a GPC analyzer, and the molecular weight is calculated by comparing the column passage time of the standard polystyrene having a known molecular weight with that of the dispersant. For the column, select a column suitable for the molecular weight range of the dispersant by looking at the calibration curve from a group of columns having different pore diameters of the filler (different molecular weights of the exclusion limit). The solvent is selected from non-aqueous solvents (THF, etc.) and aqueous solvents (water, alcohol, etc.) based on the solubility of the dispersant.

The amine value of the dispersant is preferably 5 mg / KOH to 100 mg / KOH, more preferably 10 mg / KOH to 50 mg / KOH, and even more preferably 20 mg / KOH to 40 mg / KOH.

The amine value was measured by weighing 1.9 to 2.0 g of the sample in a 150 ml beaker, dissolving it in 75 mL of glacial acetic acid, performing potentiometric titration with 0.1 N perchloric acid, and converting it to KOH mg / g. Was defined as the amine value. Potentiometric titration was measured using the HIRANUMA automatic titrator COM-1600, but any method that can obtain the same value can be used.

The method for producing the polyether dispersant is not particularly limited, and for example, those described in Japanese Patent Reissue 2004/108788, those described in Japanese Patent Application Laid-Open No. 2010-500443, and Japanese Patent Application Laid-Open No. 2007-537338. Can be mentioned.
Commercially available products include Solspers 20000, Solspers 27000, Solspers 46000 manufactured by Lubrizol, TAMNO-5 and TAMNO-15 manufactured by Nikko Chemical Co., Ltd.
Examples include the Jeffermin D series and Jeffermin M series manufactured by Huntsman.

The acid value is 100 mg / KOH or less, preferably 10 mg / KOH or less, and more preferably 1 mg / KOH or less.
To measure the acid value, weigh 0.9 to 1.3 g of the sample in an 80 ml beaker, dissolve it in 50 mL of acetone, perform potential differential titration with a 0.1 N NaOH aqueous solution, and KOH mg / g the NaOH required for the titration. The acid value was converted to. Potentiometric titration was measured using the HIRANUMA automatic titrator COM-1600, but any method that can obtain the same value can be used.

3. 3. Silane Coupling Agent The present invention is characterized by further containing a silane coupling agent.
The silane coupling agent generally refers to an organosilicon compound having both an organic functional group that can be expected to react and interact with an organic substance in one molecule and a hydrolyzable group OR. As the organic functional group, an electron-withdrawing functional group such as a vinyl group or a haloalkyl group is generally preferably used.

Generally, it is expressed by the following general formula.
[Chemical formula 4]
General formula R'nSi (OR) m
(However, n and m are integers, and n + m = 4, 0 <n <4)

In the above general formula, R may be any hydrolyzable OR, may be the same or different, and generally represents a hydrogen atom or an alkyl group having 1 to 22 carbon atoms. The alkyl group may be linear, branched or cyclic.
R'is an organic functional group that may be the same or different, and represents a functional group selected from a methacryl group, an acrylic group, a vinyl group, an epoxy group, an amino group, a mercapto group, a sulfide group and an isocyanate group.

In the present invention, the preferred silane coupling agent has an energy of the lowest empty orbital (LUMO (LUMO, English: Lowest Unoccupied Molecular Orbital)) preferably 0 to 2.5 eV, particularly preferably 0 to 2 eV, and particularly preferably 0 to 2 eV. It is from 0 to 1.5 eV.
The energy difference between the highest occupied molecular orbital (HOMO (Homo, English: Highest Occupied Molecular Orbital)) and LUMO (HOMO-LUMO energy gap) is preferably 11.5 eV or less, particularly preferably 11 eV or less, and particularly preferably 10.5 eV. It is as follows.

By using the silane coupling agent in the above range, there is an effect of stabilizing the surface of vanadium oxide destabilized by crushing and preventing reaggregation of vanadium oxide. It is considered that particularly excellent dispersion performance can be obtained.
This is presumed to be due to the following reasons.

Of the energy levels of the electron orbitals of a molecule, HOMO (Homo, English: Highest Occupied Molecular Orbital) or the highest occupied molecular orbital is the highest energy molecular orbital occupied by electrons, LUMO (English: Lowest Unoccupied). Molecular Orbital) or the lowest empty orbital is the lowest energy molecular orbital that is not occupied by electrons.
It is considered that when LUMO is in the above range and the energy of LUMO is small, and when the energy difference of HOMO-LUMO is in the above range and small, it becomes easy to transfer electrons to and from the dispersant. For this reason, it is considered that the silane coupling agent is stably present around the vanadium dioxide particles, and the dispersant is stably present via the silane coupling agent to prevent the reaggregation of the vanadium dioxide particles. ..

HOMO, LUMO and their energy differences can be calculated by computational chemistry.
In general, the density functional theory (the Kohn-Sham equation is used as the basic equation) is used to optimize the structure by finding the minimum point of energy, and calculate the electron orbit in that structure. From this, the energy of HOMO and LUMO is obtained.
The conditions are as follows.

ωB97X-D
6-31G *
In the air (in the equation, ωB97X-D is a function and 6-31G * is a basis set.)
The actual calculation can be performed using various calculation software, for example, GAUSSIAN, SPARTAN and the like.

Further, a silane coupling agent having a double bond is preferable. The orbital of HOMO-LUMO is affected by double bonds, and the double bonds make LUMO smaller and the HOMO-LUMO energy difference smaller. Therefore, it is presumed that the silane coupling agent having a double bond is excellent.

Specific examples of such a silane coupling agent include, for example, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacry as methacrylsilane. Examples include loxypropyltriethoxysilane.
Moreover, as acrylic silane, 3-acryloxypropyltrimethoxysilane can be mentioned.
Examples of vinylsilane include vinyltrimethoxysilane and vinyltriethoxysilane.
More preferably, it has one or more of a methacrylic group or an acrylic group, and more preferably, it has a methacrylic group. These are particularly excellent in terms of adsorptivity to the surface of vanadium dioxide particles, and it is considered that this improves the stability of the vanadium dioxide particle dispersion liquid.

The most preferable silane coupling agent is represented by the following formula.
[Chemical formula 5]

[Chemical formula 6]

中でも好ましいのは、〔化学式５〕の化合物である。
以上のシランカップリング剤は、ＯＲ部分が加水分解してＯＨとなった状態でもよい。

Of these, the compound of [Chemical Formula 5] is preferable.
The above silane coupling agent may be in a state where the OR portion is hydrolyzed to OH.

4. Effect of Combined Use of Polyether Dispersant and Silane Coupling Agent The present invention is characterized in that the composition containing vanadium dioxide particles contains the above-described polyether dispersant and the silane cuplinking agent. .. By containing these, it is possible to obtain a vanadium dioxide particle-containing composition which is fine, has a relatively narrow particle size distribution, and is in a stable dispersed state. Therefore, the vanadium dioxide particle-containing composition of the present invention can be used to prepare a vanadium dioxide particle-containing composition containing a binder resin, which can be applied onto various substrates to obtain a heat ray-cutting material. In particular, the vanadium dioxide particle-containing composition of the present invention can be applied onto a transparent substrate such as glass or a resin film to obtain a thermochromic material having high transparency and a low haze value.

As described above, although the reaction mechanism in which an excellent effect can be obtained by using the dispersant and the silane coupling agent in combination in the present invention has not been completely elucidated, it is presumed as follows.
The OH groups of the silane coupling agent interact with the OH groups on the surface of the vanadium dioxide particles, and the silane coupling agent surrounds the surface of the vanadium dioxide particles. Further, since the energy difference between the HOMO-LUMO of the silane coupling agent is small, the above-mentioned polyether-based dispersant and the silane coupling agent attract each other via the electrons of the silane coupling agent, and the polyether portion of the polyether-based dispersant However, it is considered that the vanadium dioxide particles are stably dispersed in the solvent by being compatible with the solvent.

The presence of the dispersant and the silane coupling agent described above in the slurry can be confirmed by mass spectrometry or IR analysis.

Mass spectrometry is the mass spectrometry (molecular weight) of particles such as atoms, molecules, and clusters that are converted into gaseous ions by some method and moved in a vacuum using electromagnetic force or by flight time difference. ) / This is an analysis method that separates and detects according to the charge ratio.
Based on the ions separated and detected according to the mass (molecular weight) / charge ratio, a bar graph with m / z on the horizontal axis and the relative intensity of the ions on the vertical axis is called a mass spectrum. The molecular weight and elemental composition can be obtained by the mass spectrum. Based on the information on molecular weight and elemental composition, the library can be used to identify monomers and functional groups and determine the molecular structure.
Since the fragment spectrum of the bond between the monomers can also be obtained from the mass spectrum, the bond information of the monomers can be known. Therefore, it is possible to obtain the molecular structure information of each sample even if the sample contains a plurality of organic compounds.
Especially in GCMS analysis, the components are separated by column and the library is prepared, so that the structure can be easily identified.
For the slurry, the monomer structure can be analyzed by performing GCMS analysis after thermal decomposition with a thermal decomposition apparatus. Additional information such as functional groups can also be obtained from the monomer structure information.
The filmed sample can also be mass-analyzed in the same manner by selecting an appropriate ionization method after thermal decomposition or direct introduction.

IR analysis can be used to identify various functional groups because they absorb at characteristic wavelengths. Both slurries and films can be analyzed directly. Whether the functional group detected from the measurement of the film or the coating film is derived from the binder resin or the dispersant or the silane coupling agent can be specified by analysis together with other analysis such as MS analysis.

In the case of a polyether dispersant, IR analysis confirms whether there is a characteristic absorption of the polyether structure. More specifically, the molecular structure including the branched structure can be specified from the spectrum value and interval of MS, the chemical shift of NMR, the integration ratio, and the shape. The same applies to the amine moiety, and MS analysis can identify the amine moiety and the structure of the functional group attached to the amine moiety.

For example, the CH ₂ CH ₂ O and CH ₃ CHCH ₂ O structures constituting the polyether moiety are detected by mass spectrometry as continuous mass spectra at intervals of molecular weights 44 and 58, respectively. The amine structure can also be identified in the library as a molecule with an amine.
Also, in IR analysis, the existence of each can be confirmed together with the mass spectrometry results by the ether bond of _{CH 2} CH ₂ O and CH ₃ CHCH _{2 O structures and the characteristic absorption wavelength of amine of amine structure.}

5. Physical Properties of Vanadium Dioxide Particle-Containing Composition The concentration of vanadium dioxide in the vanadium dioxide particle-containing composition of the present invention is preferably 5 to 50% by weight. More preferably, it is 10 to 30% by weight. The vanadium dioxide particle-containing composition of the present invention can contain a high concentration of vanadium dioxide as described above, and is generally in the form of a slurry.
Since the amount of vanadium dioxide in the coating film affects the heat ray cutting performance, it is necessary that the content of vanadium dioxide in the coating liquid is high for high performance. Whereas the conventional vanadium dioxide dispersion has a concentration of several percent at most, the vanadium dioxide of the present invention can be in the high concentration range as described above, so that a sufficient concentration for obtaining heat ray cutting performance can be obtained. It can be secured, and it can be directly adjusted to the coating liquid without concentration, so that the efficiency can be greatly improved.

Further, the viscosity of the vanadium dioxide particle-containing composition of the present invention can be as low as 10 mPa · s or less, particularly 5 mPa · s or less, and further 2 mPa · s or less. Therefore, the concentration and viscosity can be increased, and the degree of freedom in design as a coating liquid is increased.

6. Solvent The solvent that can be used is not particularly limited.
Ketones or (poly) alkylene glycol monoalkyl ethers are preferable from the viewpoints of solubility, pigment dispersibility, coatability and the like.
Ketones include methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, diacetone alcohol (4-hydroxy-4-methylpentan-2-one), 4-hydroxy-4-methylhexane-2-one. On, etc. can be mentioned.
Examples of (poly) alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol. Mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether , Dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether and the like.

7. Blending ratio The blending amount of the dispersant is preferably 5 to 100 parts by weight, preferably 10 to 50 parts by weight, and more preferably 20 to 30 parts by weight with respect to 100 parts by weight of vanadium dioxide.
The blending amount of the silane coupling agent is 5 to 100 parts by weight, preferably 10 to 50 parts by weight, and more preferably 20 to 30 parts by weight with respect to 100 parts by weight of vanadium dioxide. In the above range, the dispersion performance is particularly excellent.

8. Production Method A vanadium dioxide-containing composition can be produced by mixing each of the above components.
The above components are put into a mixing / dispersing device such as a bead mill, a planetary stirrer, a Henschel mixer, a high-pressure homogenizer, and an ultrasonic irradiator, and dispersed by wet pulverization.
In order to obtain the above particle size distribution, it is necessary to adjust conditions such as dispersion time and temperature, but since it depends on the amount charged and the compounding ratio, timely liquids are sampled to obtain the desired dispersion particle size. Confirm that the conditions are appropriate. If necessary, it is also preferable to appropriately devise an addition method so that the mixing of each component becomes uniform.

9. Uses As described above, a composition containing the vanadium dioxide particles of the present invention can be obtained. As described above, the vanadium dioxide particle-containing composition of the present invention can suppress haze to a low level and obtain high transparency. Therefore, the composition of the present invention is used in the following method for an intermediate for a thermochromic laminated glass. It can be used for applications with various thermochromic properties such as films, laminated glass, and thermochromic films.

The method for producing a film is roughly divided into a method in which fine particles that absorb at least a part of the infrared band are dispersed in a thermoplastic polymer to form a masterbatch, and the film is stretched to form a film (masterbatch method), and at least red. Examples thereof include a method (coating method) of preparing a coating liquid containing fine particles that absorb a part of the outer band and coating the coating liquid on a substrate such as a transparent resin film. Heat shielding can be imparted to glass by applying it to glass using the coating method, and a thermochromic film containing fine particles that absorb a part of the infrared band is produced by either method and attached to the glass. It is also possible to manufacture glass having thermochromic properties by attaching it. A thermochromic film may be used as an interlayer film for laminated glass.

For example, various products with thermochromic properties can be produced by the above methods, but the vanadium dioxide particles contained in the composition of the present invention are used as the fine particles that absorb at least a part of the infrared band here. can. Since the composition of the present invention contains a slurry of fine and uniform vanadium dioxide particles at a high concentration, it can be easily mixed uniformly with the thermoplastic polymer and other components of the coating liquid, and can be easily mixed with the master batch or the coating liquid. Vanadium dioxide particles can be contained therein in a fine, uniform and high concentration. Therefore, it can be expected to exhibit high thermochromic performance.

In the case of the master batch method, the thermoplastic polymer to be blended includes, for example, polyethylene naphthalate, polyethylene terephthalate, polycarbonate, polyarylate, as described in Japanese Patent Application Laid-Open No. 2010-501372 and Japanese Patent Application Laid-Open No. 2013-224046. Examples include polybutylene naphthalate, polypropylene naphthalate, polybutalene terephthalate, polypropylene terephthalate, or blends of any of these with each other or with other polymers and child polymers.

These thermoplastic polymers and the vanadium dioxide particle-containing composition of the present invention can be blended, and a small amount of solvent or dispersant can be added as needed. However, if the composition of the present invention is used, vanadium dioxide can be used in advance. Since the particles are sufficiently finely and stably dispersed, there is almost no need to add a solvent or a dispersant.

As the masterbatch, various methods conventionally known as a method for producing a polymer multilayer optical film, such as those described in Japanese Patent Publication No. 2010-501372 and Japanese Patent Application Laid-Open No. 2013-224046, can be adopted.

In the case of the coating method, usually, as described in Patent Document 22, for example, the composition of the coating liquid contains a resin component such as an ester resin, PVA, an ester urethane resin, a butyral resin, and an acrylic resin. The resin used here may be any of natural resin, semi-synthetic resin, and synthetic resin as long as it can be formed on a film, and may be any of thermoplastic resin and thermosetting resin. .. Specific resins include, for example, polyolefin resin, vinyl chloride resin, ABS resin, nylon resin, polyester, polyvinylidene chloride, polyamide, polystyrene, polyacetal, polycarbonate, acrylic resin, fluororesin, melamine resin, urea resin, and unsaturated polyester. There are resins, epoxy resins, urethane resins, phenolic resins and the like.
Plasticizers, lubricants, light stabilizers, antioxidants, antistatic agents, anti-fog agents, heat stabilizers, anti-blocking agents, surfactants, UV absorbers, dispersants, and / or surface modifications, as needed. Agents and the like can also be blended.

These resins and other components and the vanadium dioxide particle-containing composition of the present invention are uniformly adjusted to have properties suitable for coating by appropriately selecting a dispersion medium or dispersant such as an organic solvent or water, if necessary. .. By using the composition of the present invention, since the vanadium dioxide particles are already uniformly and finely dispersed, the dispersion medium can be selected and adjusted mainly from the viewpoint of coatability.

The coating liquid using the above vanadium dioxide particle-containing composition of the present invention is applied to a substrate such as a polyester film, a cycloolefin film, or a triacetyl cellulose film. The coating method is not particularly limited, and for example, blade coating, gravure coating, rod coating, knife coating, reverse roll coating, kiss coating, spray coating, offset gravure coating, dip coating, bar coating, gravure roll coating, etc. Reverse roll coating, air knife coating, Meyer bar coating, spray coating and the like can be used.

A slurry containing vanadium dioxide particles was prepared by the following method.
Vanadium dioxide particles (V _0.991 W _0.009 O ₂ , "Vanadium dioxide SV-40" manufactured by Nippon Denko Co., Ltd. (trade name), primary particle size (measured by SEM photograph) 10 to 100 μm, transition temperature (measured by DSC) , 40 ° C.) 20.0 parts by weight, polyether dispersant having the structure shown in Table 2 (“Dispersant 1”) 5.0 parts by weight, silane coupling agent having the structure shown in Table 2 (“silane coupling agent”) 1 ”) 5.0 parts by weight was added to 70.0 parts by weight of methyl ethyl ketone and mixed with a bead mill to obtain a vanadium dioxide particle dispersion.
Table 3 shows the physical characteristics of the vanadium dioxide particles in the obtained dispersion (volume% of particles D10, D50, D90 and particles having a particle size of 100 nm or more). The numerical values in the table are values obtained by putting the obtained dispersion liquid into the "Microtrack UPA-EX-150" and rounding off to the nearest whole number. (However, the volume% of the particles having a particle size of 100 nm or more is a value rounded off to the second decimal place.)

Using the above vanadium dioxide slurry, a coating plate was prepared by the following method.
[Preparation of coating liquid]
The coating liquid was prepared by mixing with the following formulations.
Vanadium dioxide-containing fine particle dispersion 25 parts by weight 25% by weight hydrophobic binder resin solution 10 parts by weight (hydrophobic binder resin: John Krill 611 molecular weight: 8100, acid value: 53BASF Japan Co., Ltd. diluted with methyl ethyl canton, Adjusted to 25% by weight)

[Preparation of coating plate]
A float glass plate (manufactured by Central Glass Co., Ltd.) having a thickness of 1.1 μm is wet-coated with the above-prepared coating liquid using a bar coater under the condition that the layer thickness after drying is 2.0 μm. Then, it was dried in an oven at 80 ° C. for 5 minutes.

[Examples 2 and 3]
A dispersion liquid was prepared in the same manner as in Example 1, a coating liquid was prepared, and a coating plate was prepared, except that the dispersion time was changed and dispersion was continued until the particle size reached the particle size shown in Table 5.
The results are shown in Tables 5 and 6.

[Example 4]
A dispersion liquid was prepared in the same manner as in Example 1 except that the dispersion time was changed and dispersion was continued until the particle size reached the particle size shown in Table 5. A coating liquid was prepared in the same manner as in Example 1 except that the composition of the coating liquid was as follows, and a coating plate was prepared.
Vanadium dioxide-containing fine particle dispersion 25 parts by weight 25% by weight hydrophobic binder resin solution 20 parts by weight (hydrophobic binder resin: John Krill 611 molecular weight: 8100, acid value: 53BASF Japan Co., Ltd. diluted with methyl ethyl canton, Adjusted to 25% by weight)
The results are shown in Tables 5 and 6.

[Examples 5 to 9]
A dispersion liquid was prepared in the same manner as in Example 1, a coating liquid was prepared, and a coating plate was prepared, except that the dispersion time was changed and dispersion was continued until the particle size reached the particle size shown in Table 3.
The results are shown in Tables 5 and 6.

[Example 10]
The dispersion liquid, the coating liquid, and the coating plate were prepared in the same manner as in Example 1 except that the dispersant 1 and the silane coupling agent 1 were each made up to 10 parts by weight.
The results are shown in Tables 5 and 6.

[Examples 11 to 13]
A dispersion liquid was prepared in the same manner as in Example 1, a coating liquid was prepared, and a coating plate was prepared, except that the dispersion time was changed and dispersion was continued until the particle size reached the particle size shown in Table 5.
The results are shown in Tables 5 and 6.

[Example 14]
A dispersion liquid was prepared, a coating liquid was prepared, and a coating plate was prepared in the same manner as in Example 1 except that the dispersant was replaced with that of Table 4.
The results are shown in Tables 5 and 6.

[Examples 15 to 18]
A dispersion liquid was prepared, a coating liquid was prepared, and a coating plate was prepared in the same manner as in Example 1 except that the silane coupling agent was replaced with that in Table 1.
The results are shown in Tables 5 and 6.
The silane coupling agents used in each Example and Comparative Example are shown in Table 1 below.
The chemical structural formulas of each silane coupling agent are shown in Table 2.
Table 3 shows the differences between HOMO, LUMO and HOMO and LUMO of each silane coupling agent.
HOMO and LUMO were calculated under the following conditions.
Soft SPARTAN
Calculation conditions Ground state density functional theory function ωB97X-D
Basis set 6-31G *
In the air

[Comparative Examples 1 to 6]
A dispersion liquid was prepared, a coating liquid was prepared, and a coating plate was prepared in the same manner as in Example 1 except that the dispersant was replaced with that shown in Table 4 below.
The results are shown in Tables 5 and 6.

For the obtained coated plate, a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., "NDH-5000") was used to haze (%) (indicated by HAZE (%) in the table) and total light transmittance (%). ) (Indicated by TT (%) in the table) was measured. The results are shown in Table 6 below.

From the above, the dispersion liquid of the present invention in which a specific dispersant and a silane coupling agent are used in combination can obtain a dispersion liquid containing extremely fine vanadium dioxide particles, and the proportion of particles having a diameter of 100 nm or more can be kept low. I know I can do it.
Further, it can be seen that this dispersion can obtain a vanadium dioxide-containing coating film having a high vanadium dioxide content and excellent haze and transparency. Specifically, as can be seen from the haze and total light transmittance of the coated plates obtained in Examples 1 to 3, the vanadium dioxide concentration in the film is 50% by weight or more, and the haze is 2% or less. It can be seen that it is possible to obtain a coating plate having a light transmittance of 25% or more, a vanadium dioxide concentration in the film of 40% by weight or more, a haze of 1% or less, and a total light transmittance of 30% or more. ..

A fine and stable vanadium dioxide particle dispersion can be obtained, which enables the formation of a coating film having low haze, excellent transparency, and excellent heat storage and thermochromic properties.

Claims (13)

A vanadium dioxide particle-containing composition containing vanadium dioxide particles, a dispersion medium, a polyether-based dispersant, and a silane coupling agent , wherein the polyether-based dispersant is an amine-based dispersant . The vanadium dioxide particle-containing composition according to claim 1, wherein the polyether-based dispersant is a polyethylene oxide-based dispersant or a polypropylene oxide-based dispersant. The vanadium dioxide particle-containing composition according to claim 1 or 2 , wherein the silane cup linking agent has a double bond. The vanadium dioxide particle-containing composition according to any one of claims 1 to 3 , wherein the silane cup linking agent has an energy of 0 to 2.5 eV in the lowest empty orbit. The vanadium dioxide particle-containing composition according to any one of claims 1 to 4 , wherein the silane cup linking agent has an energy difference between the highest occupied orbital and the lowest empty orbital of 11.5 eV or less. The vanadium dioxide particle-containing composition according to any one of claims 1 to 5 , wherein the silane cup linking agent has an energy difference between an anion and a neutral molecule of 0.05 au or less. The vanadium dioxide particle-containing composition according to any one of claims 1 to 6 , wherein the silane coupling agent has at least one of a methacrylic group and an acrylic group. The vanadium dioxide particle-containing composition according to any one of claims 1 to 7 , wherein the content of the silane coupling agent is 5 to 100 parts by weight with respect to 100 parts by weight of vanadium dioxide. The vanadium dioxide particle-containing composition according to any one of claims 1 to 8 , wherein the content of the dispersant is 5 to 100 parts by weight with respect to 100 parts by weight of vanadium dioxide. The vanadium dioxide particle-containing composition according to claim 1 to 9 , wherein the content of the vanadium dioxide particles is 5 to 50% by weight, and the viscosity is 5 mPa · s or less. A vanadium dioxide-containing thermochromic substrate, which comprises mixing the vanadium dioxide particle composition according to any one of claims 1 to 10 with a binder resin to prepare a coating liquid, applying the composition to a transparent substrate, and curing the composition. Manufacturing method. A vanadium dioxide-containing heat ray-cutting material, which comprises mixing the vanadium dioxide particle composition according to any one of claims 1 to 10 with a binder resin to prepare a coating liquid, applying the composition to a transparent substrate, and curing the mixture. Manufacturing method. A method for producing a heat-shielding film, which comprises mixing the vanadium dioxide particle composition according to any one of claims 1 to 10 with a thermoplastic polymer and stretching the obtained masterbatch.