JP2017226075A - Thermochromic film, thermochromic composite, and production method of thermochromic film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermochromic film having excellent moisture heat resistance for a long period of time.SOLUTION: A thermochromic film (1) of the present invention has an optical functional layer (3) containing at least vanadium dioxide-containing particles (VO, VO) showing thermochromic property on a substrate (2). The optical functional layer (3) contains a compound A having an amino group and a carboxy group, in which a number ratio of amino groups to carboxy groups satisfies a conditional expression (1): 1≤(number of amino groups)/(number of carboxy groups).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermochromic film, a thermochromic composite, and a method for producing a thermochromic film. More specifically, the present invention relates to a thermochromic film having excellent long-term wet heat resistance, a thermochromic composite, and a method for producing a thermochromic film.

In recent years, in order to reduce the heat felt by human skin due to the influence of sunlight entering from a car window, laminated glass having high heat insulating properties or heat shielding properties has been distributed in the market. Recently, with the spread of electric vehicles and the like, development of near-infrared light (heat ray) shielding films applied to laminated glass has been actively conducted from the viewpoint of increasing the cooling efficiency in the vehicle.
The near-infrared light shielding film can be applied to a vehicle body or a window glass of a building to reduce a load on a cooling facility such as an air conditioner in the vehicle, and is an effective means for energy saving.

As such a near-infrared light shielding film, an optical film containing a conductor such as ITO (indium tin oxide) as an infrared absorbing substance is known. Patent Document 1 discloses a near-infrared light shielding film including a functional plastic film having an infrared reflection layer and an infrared absorption layer.
Furthermore, Patent Document 2 has a reflection layer laminate in which a large number of low refractive index layers and high refractive index layers are alternately laminated, and by adjusting the thickness of each refractive index layer, near infrared light is obtained. A near-infrared light shielding film that selectively reflects has been proposed.

  The near-infrared light shielding film is preferably used due to its high near-infrared light shielding effect in a low-latitude zone near the equator where the illuminance of sunlight is high. However, in winter in mid-latitude to high-latitude zones, conversely, incident light may be uniformly shielded even when it is desired to capture sunlight as much as possible into the vehicle or the room.

In order to solve such a problem, a method of applying a thermochromic material in which the optical properties of near-infrared light shielding and transmission are controlled by temperature has been studied. A typical material is vanadium dioxide (hereinafter also referred to as “VO ₂ ”). It is known that vanadium dioxide causes a phase transition in a temperature range of about 50 to 60 ° C. and exhibits thermochromic properties.

However, it is known that vanadium dioxide promotes oxidation of vanadium dioxide and change of crystal structure by moisture and oxygen in the atmosphere. In thermochromic films containing vanadium dioxide particles, The problem is that the performance is greatly reduced.
Thus, for example, Patent Document 3 reports that vanadium dioxide particles are protected with a silane coupling agent and a long-chain alkyl resin, and Patent Document 4 reports that vanadium dioxide particles are protected with a polycarboxylic acid. Yes.
However, when the inventor made a thermochromic film containing these protected vanadium dioxide particles and conducted a durability test for wet heat resistance, particularly a long-term durability test, the durability was insufficient. I found out.

JP 2010-222233 A International Publication No. 2013/065679 Special table 2015-513508 gazette JP 2012-25629 A

  This invention is made | formed in view of the said problem and the situation, The solution subject is providing the manufacturing method of the thermochromic film excellent in long-term wet heat tolerance, a thermochromic composite_body | complex, and a thermochromic film. is there.

  In order to solve the above-mentioned problems, the present inventor has an amino group and a carboxy group in the optical functional layer in the process of examining the cause of the above-mentioned problem, and the value of the number ratio of the amino group to the carboxy group. Has been found to be capable of providing a thermochromic film, a thermochromic composite, and a method for producing a thermochromic film excellent in long-term wet heat resistance. It was.

  That is, the said subject which concerns on this invention is solved by the following means.

1. A thermochromic film having an optical functional layer containing at least vanadium dioxide-containing particles exhibiting thermochromic properties on a substrate,
The optical functional layer contains a compound A that has an amino group and a carboxy group, and the value of the number ratio of the amino group to the carboxy group satisfies the following conditional expression (1). Thermochromic film.

Conditional expression (1)
1 ≦ number of amino groups / number of carboxy groups

  2. The thermochromic film according to item 1, wherein a value of a mass ratio of the compound A to the vanadium dioxide-containing particles satisfies the following conditional expression (2).

Conditional expression (2)
0.02 ≦ mass of compound A / mass of vanadium dioxide-containing particles ≦ 0.70

  3. The thermochromic film according to Item 1 or 2, wherein the vanadium dioxide-containing particles have an average primary particle size of 100 nm or less.

  4). The thermochromic film according to any one of Items 1 to 3, wherein the optical functional layer further contains a crosslinking agent.

  5. A thermochromic composite comprising the thermochromic film according to any one of items 1 to 4.

6). A method for producing a thermochromic film having an optical functional layer containing at least vanadium dioxide-containing particles exhibiting thermochromic properties on a substrate,
Preparing a dispersion comprising Compound A having an amino group and a carboxy group, and vanadium dioxide-containing particles;
Preparing a coating liquid for forming an optical functional layer using the dispersion, applying the coating liquid for forming an optical functional layer on the substrate, and forming an optical functional layer;
Have
The method for producing a thermochromic film, wherein the value of the number ratio of amino groups to carboxy groups in the compound A satisfies the following conditional expression (1).

Conditional expression (1)
1 ≦ number of amino groups / number of carboxy groups

  By the said means of this invention, the manufacturing method of the thermochromic film excellent in long-term wet heat tolerance, the thermochromic composite_body | complex, and a thermochromic film can be provided.

  The expression mechanism / action mechanism of the effect of the present invention is not clear, but is presumed as follows.

When a compound having only an amino group is added to the coating solution for forming an optical functional layer, the amino group is adsorbed on the surface of the vanadium dioxide-containing particles, and the compound having only this amino group functions as a protective agent. However, because of the strong adsorption of nitrogen atoms, the aggregation proceeds and the stability of the particles deteriorates.
Therefore, in the present invention, by adding a compound having an amino group and a carboxy group and satisfying the conditional expression (1), the carboxy group is maintained while maintaining the function as a protective agent derived from the amino group. Thus, it is considered that the particles can be stabilized, and as a result, it is possible to prepare a coating solution with improved wet heat resistance over a long period of time, that is, to produce a thermochromic film.

Sectional drawing which shows schematic structure as an example of the thermochromic film of this invention Sectional drawing which shows schematic structure as another example of the thermochromic film of this invention Sectional drawing which shows schematic structure as another example of the thermochromic film of this invention which has a toning layer Schematic which shows an example of the flow-type reaction apparatus which comprises the hydrothermal reaction part applicable to manufacture of the vanadium dioxide containing particle | grains based on this invention.

  The thermochromic film of the present invention has an optical functional layer containing vanadium dioxide-containing particles exhibiting at least thermochromic properties on a substrate, the optical functional layer has an amino group and a carboxy group, and The compound A is characterized in that the value of the number ratio of the amino group to the group satisfies the conditional expression (1). This feature is a technical feature common to the claimed invention.

  As an embodiment of the present invention, it is preferable that the value of the mass ratio of the compound A to the vanadium dioxide-containing particles satisfies the conditional expression (2) from the viewpoint of improving the stability of the coating solution and the wet heat resistance.

  Moreover, it is preferable that the average primary particle diameter of vanadium dioxide containing particle | grains is 100 nm or less from a viewpoint of reducing a haze and improving thermochromic property.

  Moreover, it is preferable that the optical functional layer further contains a crosslinking agent from the viewpoint of wet heat resistance.

  The thermochromic film of this invention can be used suitably for a thermochromic composite_body | complex.

  Further, in the present invention, a method for producing a thermochromic film having an optical functional layer containing vanadium dioxide-containing particles exhibiting at least thermochromic properties on a substrate, the compound A having an amino group and a carboxy group, A step of preparing a dispersion liquid containing vanadium dioxide-containing particles, a coating liquid for forming an optical functional layer is prepared using the dispersion liquid, a coating liquid for forming an optical functional layer is applied on a substrate, and an optical functional layer is formed. And forming a thermochromic film in which the value of the number ratio of amino groups to carboxy groups in Compound A satisfies the conditional expression (1).

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" showing a numerical range is used by the meaning containing the numerical value described before and behind that as a lower limit and an upper limit.

《Thermochromic film》
The thermochromic film of the present invention has an optical functional layer containing vanadium dioxide-containing particles exhibiting at least thermochromic properties on a substrate, the optical functional layer has an amino group and a carboxy group, and The compound A is characterized in that the value of the number ratio of the amino group to the group satisfies the conditional expression (1) described later.

  Hereinafter, the typical structural example of the thermochromic film of this invention is demonstrated with reference to figures.

One of the preferable aspects of the thermochromic film of this invention is the structure by which the optical function layer is formed on the transparent base material.
As shown in FIG. 1, the thermochromic film 1 is configured by laminating an optical functional layer 3 on a transparent substrate 2.
The optical functional layer 3 is in a state in which vanadium dioxide-containing particles are dispersed in the binder resin B. The form of the vanadium dioxide-containing particles, which consists of a primary particle VO _S dioxide vanadium-containing particles are present independently, as a collection of two or more of vanadium dioxide-containing particles (also called aggregates.) there is a secondary particle VO _M has is. Secondary particles VO _M is also referred to as secondary particles aggregate or secondary aggregated particles.

FIG. 2 is a schematic cross-sectional view showing another example of the basic configuration of the thermochromic film 1 of the present invention, in which an optical functional layer 3 is laminated on a transparent substrate 2, and the optical function of the transparent substrate 2 is further shown. An adhesive layer (UV cut layer) 4 is laminated on the surface opposite to the side on which the layer 3 is laminated. The thermochromic film 1 of the present invention can be used by being bonded to glass G or the like via the adhesive layer 4. A hard coat layer 5 can also be provided on the optical function layer 3.
Further, the adhesive layer 4 may be provided on the optical function layer 3. In this case, the hard coat layer 5 is provided on the surface of the transparent substrate 2 opposite to the side on which the optical functional layer 3 is laminated.

Moreover, the thermochromic film 1 can also provide the toning layer in which the PET base material, dye, or the pigment contained between the optical function layer 3 and the hard-coat layer 5 further.
FIGS. 3A to 3C show a typical configuration of a thermochromic film having a toning layer.

  In the thermochromic film 11 shown in FIG. 3 (a), an optical functional layer 13 and a pressure-sensitive adhesive layer 14 containing vanadium dioxide-containing particles having thermochromic properties are laminated on one surface of a transparent substrate 12 in this order. On the other surface of the material 12, a hard coat layer 15 containing a dye or pigment having a maximum absorption wavelength in the range of a light wavelength of 350 to 750 nm is laminated. In the thermochromic film 11 shown to Fig.3 (a), the hard-coat layer 15 becomes a structure which served as the toning layer. In this embodiment, the optical functional layer 13 is provided on the adhesive layer 14 side of the transparent substrate 12, but may be provided on the hard coat layer 15 side of the transparent substrate 12 (see FIG. 2).

The thermochromic film 11 shown in FIG. 3B has an adhesive layer 14 laminated on one surface of the transparent substrate 12 and contains the optical functional layer 13 and a dye or pigment on the other surface of the transparent substrate 12. The adhesive layer 14, the transparent substrate 12, and the hard coat layer 15 are laminated in this order. In the thermochromic film 11 shown in FIG.3 (b), the adhesion layer 14 containing dye or a pigment becomes the structure which served as the toning layer.
The transparent substrates 12 in this embodiment may have the same configuration (material) or different ones.

  In the thermochromic film 11 shown in FIG. 3C, an optical functional layer 13 and a pressure-sensitive adhesive layer 14 containing a dye or a pigment together with vanadium dioxide-containing particles are laminated on one surface of a transparent substrate 12 in this order. A hard coat layer 15 is laminated on the other surface of the material 12. In the thermochromic film 11 shown in FIG.3 (c), the optical function layer 13 becomes the structure which served as the toning layer. In this embodiment as well, the optical functional layer 13 may be provided on the transparent substrate 12 on the hard coat layer 15 side as in FIG.

  As an optical characteristic of the thermochromic film of this invention, the visible light transmittance | permeability measured by JISR3106: 1998 becomes like this. Preferably it is 20% or more, More preferably, it is 40% or more. The visible light transmittance often varies depending on the application.

  Hereinafter, each member which comprises the thermochromic film of this invention is demonstrated.

<Optical function layer>
In the optical functional layer according to the present invention, a compound A having at least vanadium dioxide-containing particles, an amino group and a carboxy group, and the value of the number ratio of the amino group to the carboxy group satisfying the conditional expression (1) It is contained.

(Compound A)
The compound A according to the present invention has an amino group and a carboxy group, and the value of the number ratio of the amino group to the carboxy group satisfies the following conditional expression (1).

Conditional expression (1)
1 ≦ number of amino groups / number of carboxy groups

By satisfying the conditional expression (1), the particles can be stabilized by the carboxy group while maintaining the function as a protective agent derived from the amino group.
If the number of amino groups / number of carboxy groups <1, the pH is lowered by the carboxy groups, and the vanadium dioxide-containing particles become unstable and easily aggregate.
In the present invention, an amino group is a cyclic group in addition to a monovalent functional group (—NH ₂ , —NHR, —NRR ′) obtained by removing one hydrogen atom from ammonia, a primary amine, or a secondary amine. Also includes an amino group. The cyclic amino group is a saturated or unsaturated cyclic group having 2 to 7 carbon atoms and has a nitrogen atom as a constituent atom. Other heteroatoms such as a nitrogen atom, an oxygen atom, and a sulfur atom may further be included as the ring constituent atoms. Examples of the cyclic amino group include pyrrolidinyl group, pyrrolinyl group, piperidinyl group, morpholinyl group, piperazinyl group, thiomorpholinyl group, piperidinonyl group, piperazinonyl group and the like.

  The compound A is not particularly limited as long as it satisfies the conditional expression (1). For example, glycine, alanine, sarcosine, N- (tris (hydroxymethyl) methyl) glycine, carnosine, valine, β-alanine, serine, ε-amino-n-caproic acid, leucine, phenylalanine, threonine, asparagine, histidine, lysine, glutamine, cysteine, methionine, proline, hydroxyproline, etc., among which sarcosine, N- (Tris (hydroxymethyl) methyl) glycine and carnosine are preferred.

  Moreover, in this invention, it is preferable that the value of the mass ratio of the compound A with respect to vanadium dioxide containing particle | grains satisfy | fills the following conditional expression (2).

Conditional expression (2)
0.02 ≦ mass of compound A / mass of vanadium dioxide-containing particles ≦ 0.70

  When the value of the mass ratio of the compound A to the vanadium dioxide-containing particles is within the range, the coating liquid can be stabilized to improve the wet heat resistance, and good thermochromic properties can be obtained.

(Vanadium dioxide)
Vanadium dioxide is an embodiment of vanadium oxide. Vanadium oxide takes various forms in nature. For example, V ₂ O ₅ , H ₃ V ₂ O ₇ ⁻ , H ₂ VO ₄ ⁻ , HVO ₄ ²⁻ , VO ₄ ³⁻ , VO ²⁺ , VO ₂ , V ^Examples of the structure include ³⁺ , V ₂ O ₃ , V ²⁺ , V ₂ O ₂ , and V. The form changes depending on the environmental atmosphere. Generally, V ₂ O ₅ is formed in an acidic environment, and V ₂ O ₃ is formed in a reducing environment. Therefore, VO ₂ is relatively easy to oxidize and reduce, and the crystal structure changes depending on the surrounding environment.

(Vanadium dioxide-containing particles)
As the crystal form of the vanadium dioxide-containing particles according to the present invention, it is preferable to use rutile vanadium dioxide-containing particles (hereinafter also simply referred to as VO ₂ -containing particles) from the viewpoint of efficiently expressing thermochromic properties.
Since the rutile vanadium dioxide-containing particles have a monoclinic structure below the transition temperature, they are also called M-type. The vanadium dioxide-containing particles according to the present invention may contain other crystal-type vanadium dioxide-containing particles such as A-type or B-type, as long as the object is not impaired.

  The average primary particle diameter of the vanadium dioxide-containing particles according to the present invention is preferably 100 nm or less. Thereby, since haze is reduced and the specific surface area is increased, thermochromic properties can be improved.

The vanadium dioxide-containing particles according to the present invention are preferably present in the optical functional layer so that the number average particle diameters of the primary particles (VO _S ) and secondary particles (VO _M ) are less than 500 nm dispersed. More preferably, it is in the range of 1 to 200 nm, more preferably in the range of 5 to 100 nm, and most preferably in the range of 5 to 60 nm.

  Various measurement methods can be applied as a method for measuring the particle diameter, but measurement is preferably performed according to a dynamic light scattering method.

Moreover, as a value of the aspect-ratio of vanadium dioxide containing particle | grains, it is preferable to exist in the range of 1.0-3.0.
The vanadium dioxide-containing particles having such characteristics have a sufficiently small aspect ratio and isotropic shape, and therefore have good dispersibility when added to a solution. In addition, since the particle diameter of the single crystal is sufficiently small, better thermochromic properties can be exhibited compared to conventional particles.

  In the vanadium dioxide-containing particles according to the present invention, in addition to vanadium dioxide, for example, tungsten (W), molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium ( Ir), osmium (Os), ruthenium (Ru), germanium (Ge), chromium (Cr), iron (Fe), gallium (Ga), aluminum (Al), fluorine (F) and phosphorus (P) It may contain at least one element selected from By adding such an element, the phase transition temperature of the vanadium dioxide-containing particles can be controlled. In addition, about 0.1-10.0 atomic% is sufficient for the total amount of the said element with respect to the vanadium dioxide containing particle | grains finally obtained with respect to a vanadium (V) atom.

(Method for preparing dispersion of vanadium dioxide-containing particles)
In general, vanadium dioxide-containing particles are synthesized by a method of pulverizing a vanadium dioxide sintered body synthesized by a solid phase method or by synthesizing vanadium dioxide in a liquid phase using divanadium pentoxide (V ₂ O ₅ ) as a raw material. A water-based synthesis method in which particles are grown while being grown.

  In the present invention, vanadium dioxide produced by any method can be applied. A dispersant is added to the vanadium dioxide-containing particles produced by any of the methods, and a dispersion is prepared in an aqueous or solvent system.

In the case of water-based dispersants, in addition to low molecular weight dispersants such as alkyl sulfonates, alkyl benzene sulfonates, diethylamine, ethylenediamine, quaternary ammonium salts, polyoxyethylene nonylphenyl ether, polyexethylene lauryl Examples include acid ether, hydroxyethyl cellulose, polyvinyl pyrrolidone, polyethylene glycol, hydroxyethyl cellulose, and silane coupling agents, and polyvinyl pyrrolidone or cellulose resin is particularly preferable.
As the organic solvent-based dispersant, commonly used organic dispersants such as alkylamines, silane coupling agents, and phosphoric acid-based dispersants can be used.
The addition amount of the dispersant is preferably in the range of 1 to 50% by mass in the case of an aqueous system, and preferably in the range of 50 to 300% by mass in the case of a solvent system.

  And if these dispersing agents are used, the coating liquid for optical function layer formation can be prepared, without drying the vanadium dioxide containing particle | grains in a dispersion liquid. By forming an optical functional layer using this coating liquid for forming an optical functional layer, an optical functional layer containing vanadium dioxide-containing particles in which the number average particle diameter of primary particles and secondary particles is less than 500 nm is formed. can do.

In addition, as a method for producing vanadium dioxide-containing particles, if necessary, particles such as fine TiO _{2 serving} as the core of particle growth are added as core particles, and vanadium dioxide-containing particles are produced by growing the core particles. You can also
In addition, when using a water-soluble binder resin as the binder resin, after preparing the aqueous dispersion containing the vanadium dioxide-containing particles described above, the vanadium dioxide-containing particles are prepared without drying the vanadium dioxide-containing particles in the aqueous dispersion. It is preferable to prepare a coating solution for forming an optical functional layer by mixing with a water-soluble binder resin solution in a dispersed state.

Subsequently, the manufacturing method of the vanadium dioxide containing particle | grains by the hydrothermal method suitable for this invention is demonstrated in detail.
Below, the manufacturing process of the vanadium dioxide containing particle | grains by the typical hydrothermal method is shown.

(1) Step 1
A substance (I) containing vanadium (V), hydrazine (N ₂ H ₄ ) or a hydrate thereof (N ₂ H ₄ .nH ₂ O), and water are mixed to prepare a solution (A). The solution (A) may be an aqueous solution in which the substance (I) is dissolved in water, or may be a suspension in which the substance (I) is dispersed in water.
Examples of the substance (I) include divanadium pentoxide (V ₂ O ₅ ), ammonium vanadate (NH ₄ VO ₃ ), vanadium trichloride (VOCl ₃ ), sodium metavanadate (NaVO ₃ ), and the like. However, if it is a compound containing pentavalent vanadium (V), it will not specifically limit.
Hydrazine (N ₂ H ₄ ) and its hydrate (N ₂ H ₄ .nH ₂ O) function as a reducing agent for the substance (I) and have a property of being easily dissolved in water.

The solution (A) may further contain a substance (II) containing the element to be added in order to add the element to the finally obtained vanadium dioxide (VO ₂ ) single crystal particles. Examples of the element to be added include tungsten (W), molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium (Ir), osmium (Os), ruthenium ( Ru), germanium (Ge), chromium (Cr), iron (Fe), gallium (Ga), aluminum (Al), fluorine (F), or phosphorus (P).
By adding these elements to the finally obtained vanadium dioxide (VO ₂ ) single crystal particles, the thermochromic properties of the vanadium dioxide-containing particles, particularly the transition temperature, can be controlled.

Moreover, this solution (A) may further contain a substance (III) having oxidizing property or reducing property. Examples of the substance (III) include hydrogen peroxide (H ₂ O ₂ ). By adding the oxidizing or reducing substance (III), the pH of the solution can be adjusted, or the substance containing vanadium (V) as the substance (I) can be uniformly dissolved.

(2) Step 2
Next, a hydrothermal reaction treatment is performed using the prepared solution (A). Here, “hydrothermal reaction” means a chemical reaction that occurs in hot water (subcritical water) whose temperature and pressure are lower than the critical point of water (374 ° C., 22 MPa). The hydrothermal reaction treatment is performed, for example, in an autoclave apparatus. By the hydrothermal reaction treatment, single crystal particles containing vanadium dioxide (VO ₂ ) are obtained.
The conditions of the hydrothermal reaction treatment (for example, the amount of the reactants, the treatment temperature, the treatment pressure, the treatment time, etc.) are appropriately set, but the temperature of the hydrothermal reaction treatment is, for example, within the range of 250 to 350 ° C. Yes, preferably in the range of 250-300 ° C, more preferably in the range of 250-280 ° C. By reducing the temperature, the particle diameter of the obtained single crystal particles can be reduced, but if the particle diameter is excessively small, the crystallinity is lowered. Moreover, it is preferable that the time of a hydrothermal reaction process exists in the range of 1 hour-5 days, for example. By increasing the time, the particle diameter and the like of the obtained single crystal particles can be controlled. However, if the processing time is excessively long, the energy consumption increases.

  As a method of the above reaction, a batch type (batch type) or a semi-batch type (semi-batch type) can be carried out, but a flow type reactor (flow type reactor) such as a pressure-resistant tube type or tank type is preferable. It is also possible to use a continuous method in which the mixture is synthesized with high-temperature and high-pressure water in a subcritical or supercritical state, and particularly, a continuous method using a tubular reactor can be suitably used.

(3) Process 3
If necessary, the surface of the obtained vanadium dioxide-containing particles may be subjected to a coating treatment or a surface modification treatment with a resin. Thereby, the surface of the vanadium dioxide-containing particles is protected, and surface-modified single crystal particles can be obtained. In this invention, it is a preferable aspect to coat | cover the surface of the vanadium dioxide containing particle | grains with the binder resin which concerns on this invention whose glass transition temperature is 65 degrees C or less among them.
The “coating” referred to in the present invention may be a state where the entire surface of the particle is completely covered with the resin with respect to the vanadium dioxide-containing particles, or a part of the particle surface is covered with the resin. However, a state where 50% or more of the total area of the particle surface is covered is preferable, and a state where 80% or more is covered is more preferable.

  Through the above steps 1 to 3, a dispersion liquid containing vanadium dioxide-containing single crystal particles having thermochromic properties is obtained.

(Method of grinding vanadium dioxide-containing particles)
There are various methods for atomizing vanadium dioxide-containing particles, but there are various methods such as bead milling, ultrasonic crushing, and high-pressure homogenizer, and any method can be used to further atomize vanadium dioxide-containing particles. it can.

(Removal of impurities in the aqueous dispersion of vanadium dioxide-containing particles)
Impurities such as residues generated in the synthesis process are contained in the dispersion of the vanadium dioxide-containing particles prepared and prepared by the aqueous synthesis method. When forming the optical functional layer, these impurities may cause secondary aggregated particles and may cause deterioration of the optical functional layer during long-term storage. Therefore, impurities may be removed at the stage of the dispersion. preferable.
As a method for removing impurities in the vanadium dioxide-containing particle aqueous dispersion, conventionally known means for separating foreign substances and impurities can be applied.For example, the vanadium dioxide-containing particle aqueous dispersion is subjected to centrifugal separation, and the dioxide dioxide is removed. A method of precipitating vanadium-containing particles, removing impurities in the supernatant, and adding and dispersing the dispersion medium again may be used, or a method of removing impurities out of the system using an exchange membrane such as an ultrafiltration membrane may be used. From the viewpoint of preventing aggregation of the vanadium dioxide-containing particles, the method using an ultrafiltration membrane is most preferable.
Examples of the material for the ultrafiltration membrane include cellulose, polyethersulfone, and polytetrafluoroethylene (PTFE). Among these, polyethersulfone and PTFE are preferably used.

(Crosslinking agent)
The optical functional layer according to the present invention preferably further contains a crosslinking agent. A crosslinking agent will not be specifically limited if it can adsorb | suck to vanadium dioxide containing particle | grains. For example, a polyfunctional epoxy compound, a metal crosslinking agent, an aziridine compound, a hydrazine derivative, and the like can be mentioned.

  The polyfunctional epoxy compound is not particularly limited as long as it is a compound having two or more epoxy groups per molecule. Specifically, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A / epichlorohydrin type epoxy resin, N, N, N ′, N′-tetraglycidyl- Examples include m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylaniline, N, N-diglycidyltoluidine, and the like.

  Although it does not specifically limit as a metal crosslinking agent, For example, metal chelates, such as aluminum, zinc, cadmium, nickel, cobalt, copper, calcium, barium, titanium, manganese, iron, lead, zirconium, chromium, tin Compounds and the like. For example, an organic titanium compound, an organic zirconium compound, an organic aluminum compound manufactured by Matsumoto Fine Chemical, and a chelating agent manufactured by Kirest Co., Ltd. may be mentioned.

  Examples of the aziridine compound include N, N′-hexamethylene-1,6-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, bisisophthaloyl-1- (2 -Methylaziridine), tri-1-aziridinyl phosphine oxide, N, N'-diphenylethane-4,4'-bis (1-aziridinecarboxamide) and the like.

  Examples of the hydrazine derivative include hydrazine salts and adipic acid dihydrazide manufactured by Otsuka Chemical Co., Ltd.

  In this invention, only 1 type may be used for a crosslinking agent and it may use 2 or more types together.

  The content of the cross-linking agent is preferably in the range of 50 to 170% by mass, more preferably in the range of 60 to 150% by mass with respect to the solid content of the vanadium dioxide-containing particles. If it is 50 mass% or more, a crosslinking agent can fully adsorb | suck to vanadium dioxide containing particle | grains, can suppress aggregation of particle | grains, and if it is 170 mass% or less, a favorable haze can be obtained.

(Binder resin)
The optical functional layer according to the present invention is a preferred embodiment in which the binder resin contains vanadium dioxide-containing particles and Compound A.
Examples of the binder resin applicable to the present invention include a water-soluble binder resin and a solvent-based binder, and are not particularly limited, but among them, a water-soluble binder resin is preferable.

[Water-soluble binder resin]
The water-soluble binder resin is a resin that dissolves or disperses 1.0 g or more with respect to 100 g of water at 25 ° C. In addition, a resin that is dissolved in hot water and similarly dissolved at 25 ° C. is also defined as a water-soluble binder resin in the present invention.

  Examples of the water-soluble binder resin include gelatins, graft polymers of gelatin and other polymers, proteins such as albumin and casein, celluloses, sodium alginate, cellulose sulfate, dextrin, dextran, dextran sulfate, and other sugars. Naturally derived materials such as derivatives and thickening polysaccharides, polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester Copolymers, acrylic resins such as acrylic acid-acrylic acid ester copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylic acid ester copolymers, styrene-α -Methylstyrene- Styrene acrylic acid resin such as crylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrenesulfonate copolymer, styrene-2-hydroxyethyl acrylate copolymer, Styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer Vinyl acetate copolymers such as vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer, and salts thereof.

  Among them, a polymer containing 50 mol% or more of repeating unit components having a hydroxy group, which has a high affinity with vanadium dioxide-containing particles and has a high effect of preventing particle aggregation even during drying of film formation, is preferable. Examples thereof include celluloses, polyvinyl alcohols, and acrylic resins having a hydroxy group. Among them, polyvinyl alcohols and celluloses can be most preferably used.

Moreover, resin which has an amide group can also be used as binder resin.
Examples of the binder resin having an amide group include polyvinyl acetamide, polyacrylamide and a monomer having an amide group, and among them, polyvinyl acetamide is preferable. Those copolymerized with other types of monomers can also be used, and it is also possible to copolymerize with monomers such as acrylic acid and polyvinyl alcohol.
The molecular weights of polyvinylacetamide and polyacrylamide are preferably in the range of 100,000 to 1,000,000, since higher molecular weights have better film elongation and physical properties at break and higher resistance to blowing during drying. As a suitable example, GE191-103 (made by Showa Denko KK) is mentioned.
The monomer having an amide group can be used without particular limitation as long as it contains an amide group. Examples thereof include N-vinylacetamide, Nn-butoxymethylacrylamide, N-isobutoxymethylacrylamide, N- Methoxymethylacrylamide, Nt-butylacrylamide, N, N′-methylenebisacrylamide, N, N′-methylenebisacrylamide, N-methoxymethylmethacrylamide, Nt-butylacrylamidesulfonic acid, Nt-butyl Examples include acrylamide sulfonic acid.

(Other additives for optical functional layers)
Various additives that can be applied to the optical functional layer according to the present invention as long as the effects of the present invention are not impaired are listed below. For example, ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, JP-A-62-261476, JP-A-57-74192, JP-A-57-87989 , JP-A-60-72785, JP-A-61-146591, JP-A-1-95091, JP-A-3-13376, etc. Nonionic surfactants, JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, JP-A-61-242871, JP-A-4-219266 Fluorescent brighteners, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate and other pH adjusters, antifoaming agents, diethylene glycol Lubricants such as coal, antiseptics, antifungal agents, antistatic agents, matting agents, heat stabilizers, antioxidants, flame retardants, crystal nucleating agents, inorganic particles, organic particles, viscosity reducing agents, lubricants, infrared absorbers And various known additives such as dyes and pigments.

<Base material>
The base material (transparent base material) applicable to the present invention is not particularly limited as long as it is transparent, and examples thereof include glass, quartz, and a transparent resin film. From the viewpoint of process suitability, it is preferably a transparent resin film.
In the present invention, “transparent” means that the average light transmittance in the visible light region is 50% or more, preferably 60% or more, more preferably 70% or more, and particularly preferably 80% or more. is there.

  The thickness of the substrate is preferably in the range of 30 to 200 μm, more preferably in the range of 30 to 100 μm, and still more preferably in the range of 35 to 70 μm. If the thickness of the substrate is 30 μm or more, wrinkles and the like are less likely to occur during handling, and if it is 200 μm or less, for example, when making a laminated glass, follow the curved surface of the glass when bonded to the glass substrate. Sexuality improves.

  The substrate is preferably a biaxially oriented polyester film, but an unstretched or at least one stretched polyester film can also be used. A stretched film is preferable from the viewpoint of strength improvement and thermal expansion suppression. In particular, when the laminated glass provided with the thermochromic film of the present invention is used as an automobile windshield, a stretched film is more preferable.

  The base material preferably has a thermal shrinkage within a range of 0.1 to 3.0% at a temperature of 150 ° C. from the viewpoint of preventing generation and cracking of the thermochromic film. More preferably, it is within the range of 0.0%.

  The substrate applicable to the thermochromic film of the present invention is not particularly limited as long as it is transparent, but various resin films are preferably used. For example, polyolefin films (for example, polyethylene, polypropylene, etc.) Polyester films (for example, polyethylene terephthalate, polyethylene naphthalate, etc.), polyvinyl chloride films, triacetyl cellulose films, and the like can be used, and polyester films and triacetyl cellulose films are preferred.

  The polyester film (hereinafter simply referred to as “polyester”) is not particularly limited, but includes polyesters mainly composed of polyethylene terephthalate and polyethylene naphthalate, terephthalic acid and 2,6-naphthalenedicarboxylic acid, Polyesters composed mainly of a copolymerized polyester composed of ethylene glycol and a mixture of two or more of these polyesters are preferred.

  When using a transparent resin film as a substrate, in order to facilitate handling, particles may be contained within a range that does not impair transparency. Examples of particles used in the present invention include inorganic particles such as calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium dioxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zeolite, molybdenum sulfide, and crosslinked polymers. Examples thereof include organic particles such as particles and calcium oxalate.

In addition, the transparent resin film may be subjected to relaxation treatment or off-line heat treatment in terms of dimensional stability. It is preferable that the relaxation treatment is performed in a process from the heat setting in the stretch film forming step of the polyester film to the winding in the transverse stretch tenter or after exiting the tenter. The relaxation treatment is preferably carried out at a treatment temperature in the range of 80 to 200 ° C, more preferably in the range of 100 to 180 ° C. Moreover, it is preferable that the relaxation rate is within a range of 0.1 to 10% in both the longitudinal direction and the width direction, and more preferably, the treatment is performed within a range of 2 to 6%. The relaxed substrate is subjected to off-line heat treatment to improve heat resistance and further improve dimensional stability.
The transparent resin film is preferably coated with the undercoat layer coating solution in-line on one or both sides during the film formation process. In the present invention, undercoating during the film forming process is referred to as in-line undercoating.

<Adhesive layer>
An adhesion layer is a layer for making the thermochromic film of this invention adhere to another base material. When using the thermochromic film of this invention as a window film, it is a layer for making it adhere to a window glass.

  The pressure-sensitive adhesive used for the pressure-sensitive adhesive layer is selected from rubber-based, acrylic-based, silicon-based and urethane-based pressure-sensitive adhesives. Since there is no yellowing with time, acrylic and silicon are preferable, and acrylic is most preferable in that a general-purpose release sheet can be used.

  The thickness of the adhesive layer is preferably in the range of 5 to 30 μm. If it is 5 μm or more, the adhesiveness is stable, and if it is 30 μm or less, the adhesive does not protrude from the side of the film and is easy to handle.

As for the type of separator (release sheet) to be attached to the adhesive layer, it is possible to use a substrate such as polyester, polyethylene, polypropylene, paper, etc., which is coated with silicon, polyalkylene, or fluororesin. However, dimensional stability and smoothness can be used. From the viewpoint of peeling stability, a polyester film coated with silicon is particularly preferred.
The thickness of the separator is preferably in the range of 10 to 100 μm, more preferably in the range of 20 to 60 μm. If it is 10 μm or more, the film is not wrinkled due to heat during coating and drying, and it is preferably 100 μm or less from the viewpoint of economy.

<Hard coat layer>
The thermochromic film of the present invention may be provided with a hard coat layer (also referred to as HC layer) in order to improve the durability of the film.

  As a hard coat material for the hard coat layer, an inorganic material typified by polysiloxane, an active energy ray curable resin, or the like can be used.

  Inorganic materials require moisture curing (room temperature to warming), and it is preferable to use an active energy ray-curable resin from the viewpoints of curing temperature, curing time, and cost. The active energy ray resin refers to a resin that is cured through a crosslinking reaction or the like by irradiation with active rays such as ultraviolet rays or electron beams.

  As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the active energy ray curable resin layer is cured by irradiation with an active ray such as an ultraviolet ray or an electron beam. It is formed. Typical examples of the active energy ray curable resin include an ultraviolet curable resin and an electron beam curable resin, and a resin curable by ultraviolet irradiation is preferable.

  Examples of the ultraviolet curable resin include an ultraviolet curable acrylate resin, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable resin. A type epoxy resin or the like is preferably used. Of these, ultraviolet curable acrylate resins are preferred.

The UV curable urethane acrylate resin generally contains 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) in addition to a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer. It can be easily obtained by reacting an acrylate monomer having a hydroxy group such as 2-hydroxypropyl acrylate. For example, a mixture of 100 parts Unidic 17-806 (manufactured by DIC Corporation) and 1 part of Coronate L (manufactured by Tosoh Nippon Polyurethane Corporation) described in JP-A-59-151110 is preferably used. .
The UV curable polyester acrylate resin can be easily obtained by reacting a monomer such as 2-hydroxyethyl acrylate, glycidyl acrylate, or acrylic acid with a hydroxyl group or a carboxy group at the end of the polyester. Sho 59-151112).
The ultraviolet curable epoxy acrylate resin is obtained by reacting a terminal hydroxyl group of an epoxy resin with a monomer such as acrylic acid, acrylic acid chloride, or glycidyl acrylate.
Examples of ultraviolet curable polyol acrylate resins include ethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipenta. Examples include erythritol pentaacrylate, dipentaerythritol hexaacrylate, and alkyl-modified dipentaerythritol pentaacrylate.

<Toning layer>
In the present invention, in order to adjust the color of the thermochromic film, a toning layer containing a dye or pigment having a maximum absorption wavelength in the range of 350 to 750 nm may be provided.
The “dye” refers to a dye that is used as a coloring material to be colored and dissolves in any solvent such as water or an organic solvent. “Pigment” refers to a pigment that is used as a coloring material to be colored and is in the form of a fine powder of a pigment that does not dissolve in water or an organic solvent.

  Specific examples of the dye having a maximum absorption wavelength in the light wavelength range of 350 to 750 nm that can be used in the present invention include anthraquinone dyes, phthalocyanine dyes, triphenylmethane dyes, triarylmethane dyes, and indigo dyes. And pigments.

  As the pigment, a compound classified as a pigment in the color index (CI; issued by The Society of Dyersand Colorists) can be used, and among these, phthalocyanine-based C.I. I. Pigment blue 15: 3 (maximum absorption wavelength: 630 nm, 720 nm), C.I. I. Pigment Blue 15: 4 (maximum absorption wavelength: 640 nm, 740 nm), C.I. I. Pigment Blue 16 (maximum absorption wavelength: 620 nm, 690 nm) or the like can be preferably used.

<< Method for producing thermochromic film >>
The method for producing a thermochromic film of the present invention comprises a step of preparing a dispersion containing compound A and vanadium dioxide-containing particles, a coating solution for forming an optical functional layer using the dispersion, and an optical on a substrate. And applying a functional layer forming coating solution to form an optical functional layer.

<Preparation of coating solution for optical functional layer formation>
The coating solution for forming an optical functional layer is prepared by mixing Compound A, for example, a dispersion of vanadium dioxide-containing particles prepared as described above, and a binder resin to obtain a coating solution for forming an optical functional layer. Prepare.

  Although there is no restriction | limiting in particular as content of the vanadium dioxide containing particle | grains in a coating liquid, It is preferable to exist in the range of 5-60 mass% with respect to the optical function layer total mass, More preferably, it is 5-40 mass%. And more preferably in the range of 5 to 30% by mass.

<Formation of optical functional layer>
In the step of forming the optical functional layer, the optical functional layer-forming coating solution is applied onto the substrate, and if necessary, the optical functional layer is formed by performing a drying treatment and a curing treatment, and a thermochromic film. Can be manufactured.
Examples of the wet coating method used for forming the optical functional layer include a roll coating method, a rod bar coating method, an air knife coating method, a spray coating method, a slide type curtain coating method, US Pat. No. 2,761,419, and US Pat. No. 2,761791. Examples thereof include a slide hopper coating method and an extrusion coating method described in the specification.

  In the above-described method for manufacturing a thermochromic film, a thermochromic film including a base material and an optical functional layer is manufactured. However, after the optical functional layer is formed on the base material, the optical functional layer is used as a basis. It is good also as what manufactures the thermochromic film which peels from a material and consists only of an optical function layer. Moreover, it is good also as what manufactures a thermochromic film by bonding the optical function layer peeled from the base material to another base material.

《Thermochromic Complex》
As a use of the thermochromic film of the present invention, a thermochromic composite comprising a thermochromic film can be mentioned. For example, the thermochromic film of the present invention can be used after being pasted on glass. Although the glass which bonded the thermochromic film can be used for a motor vehicle, a rail vehicle, an aircraft, a ship, a building, etc., it does not restrict | limit in particular to this. Specifically, it can be used for window glass for construction, rear glass for vehicles, roof glass and the like.

  Further, the present invention can be applied to other than glass, and it can be a thermochromic composite composed of a thermochromic film support including glass and a thermochromic film.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

《Preparation of thermochromic film》
Thermochromic films 101-115 were produced as follows.

<Preparation of thermochromic film 101>
(Preparation of vanadium dioxide-containing particle dispersion 1)
A dispersion containing vanadium dioxide-containing particles was prepared according to the following method using the flow reactor 101 having the hydrothermal reaction section 116 shown in FIG.

First, in the raw material liquid container 105, 19.0 g of vanadium oxide sulfate (IV) (VOSO ₄ ) was dissolved in ion-exchanged water (dissolved oxygen amount: 8.1 mg / L) to 300 ml. 68 ml of a 3.0 mol / L NH ₃ aqueous solution was added as an alkali to prepare a raw material liquid 1 having a pH of 8.0 (liquid temperature: 25 ° C.).
On the other hand, ion exchange water (dissolved oxygen amount: 8.1 mg / L) was stored as the raw material liquid 2 in the raw material liquid container 102.

The raw material liquid 1 containing vanadium oxide oxide (IV) and alkali is fed from the raw material liquid container 105 through the flow path 106 by a pump 107 and pressurized by a heating medium 115 at 25 ° C. and 30 MPa. did.
On the other hand, the ion-exchanged water that is the raw material liquid 2 is fed from the raw material liquid container 102 through the flow path 103 by the pump 104, and heated and pressurized by the heating medium 113 at 440 ° C. under the condition of 30 MPa to obtain supercritical water Got.

Next, a raw material liquid 1 containing vanadium oxide (IV) sulfate and an alkali and a raw material liquid 2 that is supercritical water at a confluence point MP under the condition that the raw material liquid 1: the raw material liquid 2 = 1: 4. By mixing, a reaction solution 1 was prepared and fed to the hydrothermal reaction section 116. In the hydrothermal reaction section 116, the reaction liquid 1 was sent to the heating section piping 117 disposed in the heating medium 114. As hydrothermal reaction conditions in the heating pipe part 117, the treatment time (passage time) was 2 seconds under the conditions of 400 ° C. and 30 MPa, and vanadium dioxide (VO ₂ ) -containing particles were formed. Subsequently, the reaction liquid 1 was cooled in the cooling unit 108 to prepare a dispersion containing vanadium dioxide-containing particles and water.

  After the reaction, the resulting product is washed using ultrafiltration, the concentration of the finished vanadium dioxide-containing particles is adjusted to 3.0% by mass, and the compound is further added to 100 parts by mass of the vanadium dioxide-containing particles. A is added as sarcosine (manufactured by Kanto Chemical Co., Inc.) at a ratio of 1 part by mass, and dispersed with a super apex mill manufactured by Kotobukisha using zirconia beads having a particle size of 30 μm, and a dispersion 1 of vanadium dioxide-containing particles is obtained. Prepared.

(Preparation of coating solution for optical functional layer formation)
The following constituent materials were sequentially added, mixed and dissolved, and diluted with water to a solid content of 4% by mass to prepare an aqueous optical functional layer forming coating solution.

Vanadium dioxide-containing particle dispersion 1 (solvent: water) 10 parts by mass Binder resin (GE191-103, manufactured by Showa Denko KK) 89.5 parts by mass Neugen XL-100 (Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by mass

(Formation of optical functional layer)
Using an extrusion coater on a 50 μm thick polyethylene terephthalate film (Toyobo A4300, double-sided easy-adhesion layer), the thickness after drying the prepared coating solution for forming an optical functional layer is 1.5 μm. The wet coating was performed by adjusting the coating amount, and an optical functional layer was formed by blowing warm air of 90 ° C. for 1 minute to form a thermochromic film 101.

<Preparation of thermochromic film 102>
A thermochromic film 102 was produced in the same manner as in the production of the thermochromic film 101 except that the dispersion 2 in which the amount of sarcosine in the vanadium dioxide-containing particle dispersion 1 was changed from 1 part by mass to 5 parts by mass was used.

<Preparation of thermochromic film 103>
A thermochromic film 103 was produced in the same manner as in the production of the thermochromic film 101 except that the dispersion 3 in which the amount of sarcosine in the vanadium dioxide-containing particle dispersion 1 was changed from 1 part by mass to 10 parts by mass was used.

<Preparation of thermochromic film 104>
A thermochromic film 104 was produced in the same manner as in the production of the thermochromic film 101 except that the dispersion 4 in which the amount of sarcosine in the vanadium dioxide-containing particle dispersion 1 was changed from 1 part by mass to 30 parts by mass was used.

<Preparation of thermochromic film 105>
A thermochromic film 105 was produced in the same manner as in the production of the thermochromic film 101 except that the dispersion 5 in which the amount of sarcosine in the vanadium dioxide-containing particle dispersion 1 was changed from 1 part by mass to 60 parts by mass was used.

<Preparation of thermochromic film 106>
In the production of the thermochromic film 101, a thermochromic film 106 was produced in the same manner except that the dispersion 6 in which the amount of sarcosine of the vanadium dioxide-containing particle dispersion 1 was changed from 1 part by mass to 80 parts by mass was used.

<Preparation of thermochromic film 107>
A thermochromic film 107 was produced in the same manner as in the production of the thermochromic film 103 except that sarcosine was changed to N- (tris (hydroxymethyl) methyl) glycine.

<Preparation of thermochromic film 108>
A thermochromic film 108 was produced in the same manner as in the production of the thermochromic film 103 except that sarcosine was changed to L-histidine.

<Preparation of thermochromic film 109>
A thermochromic film 109 was produced in the same manner as in the production of the thermochromic film 103 except that sarcosine was changed to proline.

<Preparation of thermochromic film 110>
In the production of the thermochromic film 103, a thermochromic film 110 was produced in the same manner except that the coating solution for forming an optical functional layer was prepared as follows.

(Preparation of coating solution for optical functional layer formation)
The following constituent materials were sequentially added, mixed and dissolved, and diluted with water to a solid content of 4% by mass to prepare an aqueous optical functional layer forming coating solution.

Vanadium dioxide-containing particle dispersion 3 (solvent: water) 10 parts by mass Binder resin (GE191-103, manufactured by Showa Denko KK) 79.5 parts by mass Crosslinker (TC-400, manufactured by Matsumoto Fine Chemical Co.) 10 parts by mass Neugen XL- 100 (Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by mass

<Preparation of thermochromic film 111>
(Preparation of vanadium dioxide-containing particle solvent dispersion 7)
10 parts by mass of vanadium dioxide-containing particles (VO ₂ , manufactured by Shinsei Chemical Industry Co., Ltd.), 20 parts by mass of methionine as compound A (dispersing agent) are added to 70 parts by mass of methyl ethyl ketone, and super apex mill (Koto Kogyo Co., Ltd.) is used. To obtain a vanadium dioxide-containing particle solvent dispersion 7.

(Preparation of coating solution for optical functional layer formation)
The following constituent materials were sequentially added, mixed and dissolved, and diluted with methyl ethyl ketone so as to have a solid content of 4% by mass to prepare a solvent-based coating solution for forming an optical functional layer.

Vanadium dioxide-containing particle solvent dispersion 7 10 parts by weight Diacetone acrylamide (manufactured by Nippon Kasei Co., Ltd.) 80 parts by weight Irgacure 127 (manufactured by BASF Corporation) 1 part by weight Megafax F-552 (methyl ethyl ketone diluent (1% by weight), DIC 0.5 parts by mass)

<Preparation of thermochromic film 112>
In producing the thermochromic film 101, a thermochromic film 112 was produced in the same manner except that the vanadium dioxide-containing particle dispersion 1 was prepared by removing sarcosine.

<Preparation of thermochromic film 113>
A thermochromic film 113 was produced in the same manner as in the production of the thermochromic film 103 except that sarcosine was changed to propylamine.

<Preparation of thermochromic film 114>
A thermochromic film 114 was produced in the same manner as in the production of the thermochromic film 103 except that sarcosine was changed to Marialim SC-0505K (manufactured by NOF Corporation), which is a polycarboxylic acid.

<Preparation of thermochromic film 115>
A thermochromic film 115 was produced in the same manner as in the production of the thermochromic film 103 except that sarcosine was changed to diethylenetriaminepentaacetic acid.

<Evaluation>
The following evaluation was performed about the produced thermochromic films 101-115.
The evaluation results are shown in Table 1.

<Measurement of average primary particle size>
Each of the prepared vanadium dioxide-containing dispersions is mixed with water or a solvent (solvent at the time of preparing each dispersion) so that the concentration of vanadium dioxide-containing particles is 0.01% by mass with respect to the total mass of the dispersion. Then, a sample for measurement was prepared by dispersing with ultrasonic waves for 15 minutes.
Next, the hydrodynamic diameter (nm) was measured by a dynamic light scattering (DLS) method using a dynamic light scattering analyzer (DLS-8000, manufactured by Otsuka Electronics Co., Ltd.). Based on this, the average particle size of the particle size distribution by cumulant analysis was determined, and this value was defined as the average primary particle size (D) (nm).
In addition, about the dispersion liquid of the thermochromic film 115, it aggregated and the average primary particle diameter was not able to be measured.

<Thermochromic properties (TC properties)>
About each produced thermochromic film, the transmission spectrum and the reflection spectrum were measured using the spectrophotometer (the JASCO make, V-670) on the conditions of temperature 25 degreeC and 70 degreeC. Next, according to the method described in JIS R 3106: 1998, the measurement value and the solar reflection weight coefficient are calculated to obtain solar reflectance, solar transmittance, and visible light transmittance, and the solar heat acquisition rate ( TTS (%)) was calculated. Furthermore, ΔTTS (= TTS (25 ° C.) − TTS (70 ° C.)) at different temperatures was calculated and evaluated according to the following evaluation criteria.

○: 8% ≦ ΔTTS
Δ: 5% ≦ ΔTTS <8%
×: ΔTTS <5%

<Stability>
Each coating solution for forming an optical functional layer is put in a glass bottle and stored in a room at 25 ° C. and 50% RH. The state of the coating solution after storage for 3 days and after storage for 6 days is visually confirmed and evaluated according to the following evaluation criteria. did.

○: No aggregation even after 6 days Δ: Confirmation of aggregation after 6 days ×: Confirmation of aggregation after 3 days

<Damp heat resistance>
About each produced thermochromic film, permeation before storage and after storage for 300 hours in a high-temperature and high-humidity environment at a temperature of 85 ° C. and a humidity of 85% RH using a spectrophotometer (manufactured by JASCO, V-670) The spectrum was measured to calculate ΔL ^* , Δa ^* , Δb ^* , and the color difference (ΔE) was calculated.
Moreover, also about haze (%), it measured using a haze meter (NDH2000, Nippon Denshoku Industries Co., Ltd.), (DELTA) haze before and behind storage (= haze (after storage)-haze (before storage)) was calculated, and the following Evaluation was performed according to the evaluation criteria.

A: ΔE ≦ 2
○: 2 <ΔE ≦ 3
Δ: 3 <ΔE <4
×: 4 ≦ ΔE

○: Δhaze ≦ 2%
Δ: 2% <Δhaze <4%
×: 4% ≦ Δhaze

As is clear from Table 1, the thermochromic film of the present invention effectively suppresses the color difference and haze change width before and after storage under high temperature and high humidity as compared with the thermochromic film of the comparative example. Was confirmed.
From the above, it is long-term that the optical functional layer contains a compound A that has an amino group and a carboxy group and the value of the number ratio of the amino group to the carboxy group satisfies the conditional expression (1). It turns out that it is useful for providing the thermochromic film excellent in wet heat resistance.

  In addition, each thermochromic film produced is a transparent adhesive sheet (manufactured by Nitto Denko Corporation, LUCIACS CS9621T) in a size of 15 cm × 20 cm of a 1.3 mm thick glass plate (manufactured by Matsunami Glass Industrial Co., Ltd., “Slide Glass White Edge Polish”). When the thermochromic film-glass composite was produced by laminating using the same, similar effects could be confirmed.

DESCRIPTION OF SYMBOLS 1,11 Thermochromic film 2,12 Base material 3,13 Optical functional layer 4,14 Adhesive layer 5,15 Hard coat layer 101 Flow-type reaction apparatus 102,105 Raw material liquid container 103,106,111,118 Flow path (pipe) )
104, 107, 112 Pump 108 Cooling unit 109, 110 Tank 113, 114, 115 Heating medium 116 Hydrothermal reaction unit 117 Heating unit piping 119 Control valve B Binder resin G Glass VO _S Primary particle VO _M Secondary particle C Refrigerant IN Heating medium inlet OUT Heating medium outlet L Line length MP of the heating section MP Junction point TC Temperature sensor

Claims (6)

A thermochromic film having an optical functional layer containing at least vanadium dioxide-containing particles exhibiting thermochromic properties on a substrate,
The optical functional layer contains a compound A that has an amino group and a carboxy group, and the value of the number ratio of the amino group to the carboxy group satisfies the following conditional expression (1). Thermochromic film.
Conditional expression (1)
1 ≦ number of amino groups / number of carboxy groups The thermochromic film according to claim 1, wherein a value of a mass ratio of the compound A to the vanadium dioxide-containing particles satisfies the following conditional expression (2).
Conditional expression (2)
0.02 ≦ mass of compound A / mass of vanadium dioxide containing particles ≦ 0.70   The thermochromic film according to claim 1 or 2, wherein an average primary particle size of the vanadium dioxide-containing particles is 100 nm or less.   The thermochromic film according to any one of claims 1 to 3, wherein the optical functional layer further contains a crosslinking agent.   A thermochromic composite comprising the thermochromic film according to any one of claims 1 to 4. A method for producing a thermochromic film having an optical functional layer containing at least vanadium dioxide-containing particles exhibiting thermochromic properties on a substrate,
Preparing a dispersion comprising Compound A having an amino group and a carboxy group, and vanadium dioxide-containing particles;
Preparing a coating liquid for forming an optical functional layer using the dispersion, applying the coating liquid for forming an optical functional layer on the substrate, and forming an optical functional layer;
Have
The method for producing a thermochromic film, wherein the value of the number ratio of amino groups to carboxy groups in the compound A satisfies the following conditional expression (1).
Conditional expression (1)
1 ≦ number of amino groups / number of carboxy groups

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