WO2017187715A1

WO2017187715A1 - Thermochromic film, production method thereof, and thermochromic film/glass composite

Info

Publication number: WO2017187715A1
Application number: PCT/JP2017/004903
Authority: WO
Inventors: 丈範熊谷; 友香子高
Original assignee: コニカミノルタ株式会社
Priority date: 2016-04-28
Filing date: 2017-02-10
Publication date: 2017-11-02
Also published as: JP2019108409A

Abstract

The present invention addresses the problem of providing: a thermochromic film having excellent moist heat durability; a thermochromic film/glass composite obtained by laminating said film; and a method for producing a thermochromic film. The thermochromic film according to the present invention has an optically functional layer that contains vanadium dioxide particles exhibiting thermochromism, the thermochromic film being characterized in that: the optically functional layer contains a water-soluble resin (P₁) and a hydrophobic resin (P₂); and the value of the mass ratio between the two resins (P₁/P₂) falls within a range of 0.3-10.0.

Description

Thermochromic film, method for producing the same, and thermochromic film-glass composite

The present invention relates to a thermochromic film, a thermochromic film-glass composite, and a method for producing a thermochromic film. More specifically, the present invention relates to a thermochromic film having excellent wet heat durability, a thermochromic film-glass composite formed by laminating the thermochromic film, 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 the car window, laminated glass with high heat insulation or heat shielding properties has been distributed on 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 disclosed. 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 layer thickness of each refractive index layer, near infrared light can be obtained. A near-infrared light shielding film that selectively reflects light has been proposed.

The near-infrared light shielding film having such a configuration 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 the mid-latitude to high-latitude zones, conversely, there is a problem that incident light is uniformly shielded even when it is desired to capture sunlight as much as possible in the vehicle or indoors.

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

VO ₂ can maintain a high thermochromic property and a nanoparticle state in an aqueous dispersion state. This is thought to be due to the fact that the crystal structure of VO ₂ changes with the phase transition, the volume increases on the high temperature side, and the oxidation state and high crystallinity of the surface are involved in chromic properties. . However, it is known that the oxidation of VO ₂ and the change of the crystal structure are promoted by moisture and oxygen in the atmosphere, and in the thermochromic film containing VO ₂ particles, the thermochromic property decreases with time. Is a problem.

For example, Patent Document 3 reports that VO ₂ is protected with a silane coupling agent and a long-chain alkyl resin, and a polymer emulsion is used as a binder.

However, when the inventor produced a thermochromic film containing these protected VO ₂ particles and conducted a durability test on wet heat durability, it was found that the durability was insufficient.

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

The present invention has been made in view of the above-mentioned problems and circumstances, and the problem to be solved is a thermochromic film having excellent wet heat durability, a thermochromic film-glass composite formed by laminating it, and a thermochromic film. It is to provide a manufacturing method.

As a result of studying to solve the above-mentioned problems, the present inventors have found that the optical functional layer containing vanadium dioxide particles of a thermochromic film contains a water-soluble resin and a hydrophobic resin as a binder in a ratio within a specific range. Thus, it was found that a thermochromic film exhibiting excellent wet heat durability was obtained, and the present invention was achieved.

That is, the above-mentioned problem of the present invention is solved by the following means.

1. A thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, wherein the optical functional layer contains a water-soluble resin (P ₁ ) and a hydrophobic resin (P ₂ ), and A thermochromic film having a mass ratio value (P ₁ / P ₂ ) in the range of 0.3 to 10.0.

2. 2. The thermochromic film according to item 1, which contains a urethane resin as the hydrophobic resin.

3. 3. The thermochromic film according to

item

1 or 2, which contains a resin having an amide group as the water-soluble resin.

4. 4. The thermochromic film according to item 3, wherein the resin having an amide group is polyvinyl acetamide.

5. The thermochromic film according to any one of Items 1 to 4, wherein the water-soluble resin contains gelatin.

6. The thermochromic film according to any one of items 1 to 5, wherein the optical functional layer contains a nitrogen-containing compound having a molecular weight in the range of 100 to 10,000.

7). A thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, wherein the optical functional layer contains a water-soluble resin (P ₁ ) and a hydrophobic resin (P ₂ ), and A thermochromic film having a mass ratio value (P ₁ / P ₂ ) in a range of 0.3 to 10.0 and containing an organometallic compound in the optical functional layer.

8. The thermochromic film according to item 7, wherein the organometallic compound is selected from an organosilane compound, an organotitanium compound, and an organozirconium compound.

9. A thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties on a substrate, wherein the optical functional layer comprises a water-soluble resin (P ₁ ) and a hydrophobic resin (P ₂ ). And the mass ratio value (P ₁ / P ₂ ) is in the range of 0.3 to 10.0, and 70% by mass of the vanadium dioxide particles with respect to the thickness n of the optical functional layer. The above is unevenly distributed in the range of n / 2 from the base material side.

10. A thermochromic film-glass composite comprising the thermochromic film according to any one of items 1 to 6 and glass laminated.

11. A method for producing a thermochromic film for producing a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, comprising an aqueous emulsion containing a hydrophobic resin (P ₂ ) and a water-soluble resin (P ₁ )), and a step of applying a coating solution for forming an optical functional layer whose mass ratio value (P ₁ / P ₂ ) is within a range of 0.3 to 10.0. A method for producing a thermochromic film.

12 A method for producing a thermochromic film for producing a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, comprising an aqueous emulsion containing a hydrophobic resin (P ₂ ) and a water-soluble resin (P ₁ ) The manufacturing method of the thermochromic film which has the process of apply | coating the coating liquid for optical function layer formation containing, and the process of carrying out high-temperature high-humidity processing of an optical function layer.

By the above means of the present invention, a thermochromic film having excellent wet heat durability, a thermochromic film-glass composite formed by laminating the thermochromic film, and a method for producing a thermochromic film can be provided.

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

The optical functional layer of the thermochromic film of the present invention contains a water-soluble resin and a hydrophobic resin together with vanadium dioxide particles. These are considered to function as a binder of the optical functional layer. The water-soluble resin interacts with the vanadium dioxide particles to suppress the aggregation of the particles and stabilize the dispersion, and the hydrophobic resin reduces the water absorption of the resin. It is done. In addition, by performing high-temperature and high-humidity treatment, the thickness n of the optical functional layer is reduced by the phase separation of the resin so that the vanadium dioxide particles are lower than n / 2 in the thickness direction of the optical functional layer from the base material. The structure is higher than that of the upper layer, preventing the influence of moisture and oxygen, improving long-term wet heat durability, and effectively blocking moisture and oxygen from entering the optical functional layer from the outside. It is presumed that discoloration and thermochromic deterioration in a high temperature and high humidity environment could be prevented by expressing the effect of this. Further, it is presumed that by containing the organometallic compound, the organometallic compound adsorbs with the vanadium dioxide particles and effectively blocks the intrusion of moisture and oxygen into the optical functional layer, thereby obtaining the same effect. By adopting such a form, it is presumed that a thermochromic film in which high thermochromic properties are maintained for a long time can be produced.

Schematic sectional view showing an example of the configuration of the thermochromic film of the present invention Schematic sectional view showing another example of the configuration of the thermochromic film of the present invention

The thermochromic film of the present invention is a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, the optical functional layer comprising a water-soluble resin (P ₁ ) and a hydrophobic resin (P ₂ ), and the mass ratio value (P ₁ / P ₂ ) is in the range of 0.3 to 10.0. This feature is a technical feature common to the claimed invention.

As an embodiment of the present invention, as the hydrophobic resin, in addition to the improvement of wet heat durability, it is possible to impart flexibility to the optical functional layer by containing a urethane resin, and to further improve the adhesion to the substrate. It is preferable at the point which has the effect to improve.

Moreover, VO ₂ and particles interact, in that it can prevent was stably dispersed agglomerate the VO ₂ particles especially during coating and drying, as the water-soluble resin preferably contains a resin having an amide group. Furthermore, it is more preferable that the resin having an amide group is polyvinyl acetamide.

As the water-soluble resin, it is preferable that gelatin is contained from the viewpoint of interacting with the VO ₂ particles, and particularly capable of stably dispersing the VO ₂ particles during coating and drying and preventing aggregation.

In addition, when the optical functional layer contains a nitrogen-containing compound having a molecular weight in the range of 100 to 10,000, it has an effect of interacting with the VO ₂ particle surface, making the VO ₂ particle hydrophobic, and improving wet heat durability. Is preferable.

Moreover, a thermochromic film having an optically functional layer containing vanadium dioxide particles exhibiting thermochromic, wherein the optical functional layer contains a water-soluble resin (P ₁₎ and the hydrophobic resin (P ₂₎ The mass ratio value (P ₁ / P ₂ ) is in the range of 0.3 to 10.0, and the optical functional layer contains an organometallic compound, This is preferable because it effectively blocks oxygen from entering.

It is preferable that the organometallic compound is selected from an organosilane compound, an organotitanium compound, and an organozirconium compound.

Moreover, a thermochromic film having an optically functional layer containing vanadium dioxide particles exhibiting thermochromic on a substrate, wherein the optical functional layer is a water-soluble resin (P ₁₎ and the hydrophobic resin (P ₂₎ The mass ratio value (P ₁ / P ₂ ) is in the range of 0.3 to 10.0, and the vanadium dioxide particles have a thickness of 70 with respect to the film thickness n of the optical functional layer. It is preferable from the viewpoint of improving the wet heat durability that the mass% or more is unevenly distributed in the range of n / 2 from the substrate side.

The thermochromic film of the present invention can be suitably used for a thermochromic film-glass composite formed by laminating the thermochromic film and glass.

The method for producing a thermochromic film of the present invention is a method for producing a thermochromic film for producing a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, and comprising a hydrophobic resin (P ₂ ) Containing an aqueous emulsion and a water-soluble resin (P ₁ ), and the mass ratio value (P ₁ / P ₂ ) is within the range of 0.3 to 10.0. It is preferable that it is an aspect which has the process of apply | coating a coating liquid.

Furthermore, the method for producing a thermochromic film of the present invention is a method for producing a thermochromic film for producing a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, comprising a hydrophobic resin ( a step of applying an optical functional layer forming coating liquid containing an aqueous emulsion and the water-soluble resin containing P _₂₎ (P _1), is preferably a mode having a step of adding a high temperature and high humidity conditions.

Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In the following description, “˜” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

《Thermochromic film》
The thermochromic film of the present invention is a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, the optical functional layer comprising a water-soluble resin (P ₁ ) and a hydrophobic resin (P ₂ ), and the mass ratio value (P ₁ / P ₂ ) is in the range of 0.3 to 10.0.

A typical configuration example of the thermochromic film of the present invention will be described with reference to the drawings.

One of the preferable embodiments of the thermochromic film of the present invention is a configuration in which an optical functional layer is formed on a transparent substrate.

FIG. 1 is a schematic cross-sectional view showing an example of a basic configuration of a thermochromic film having an optical functional layer containing vanadium dioxide particles, a water-soluble resin, and a hydrophobic resin defined in the present invention.

A thermochromic film 1 shown in FIG. 1 has a configuration in which an optical functional layer 3 is laminated on a transparent substrate 2. The optical functional layer 3 is present in a state where vanadium dioxide particles are dispersed in a resin binder B1 made of a water-soluble resin and a hydrophobic resin contained in the optical functional layer. This is vanadium dioxide particles, constitute the primary particles VO _S of vanadium dioxide vanadium dioxide particles are present independently, an aggregate of two or more vanadium dioxide particles (also called aggregates), VO ₂ of secondary particles VO _M is present. In the present invention, an aggregate of two or more vanadium dioxide particles is collectively referred to as secondary particles, and is also referred to as secondary particle aggregates or secondary aggregate particles.

In the present invention, the number average particle diameter measured by the total particles of the primary particles VO _S and secondary particles VO _M of VO ₂ particles in the optical function layer 3 is preferably less than 500 nm.

The number average particle diameter of the VO ₂ particles in the optical functional layer can be determined according to the following method.

Another preferred embodiment of the thermochromic film of the present invention is a hybrid structure in which the optical functional layer also serves as a resin base material.

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 the transparent substrate 2 and the optical functional layer 3 shown in FIG. The near infrared light shielding layer 4 is laminated on the side opposite to the side on which the optical functional layer 3 of the material 2 is laminated. Thus, in the thermochromic film of this invention, it is good also as a structure which has the near-infrared-light shielding layer 4. FIG. As the near-infrared light shielding layer 4, for example, a layer having a function of shielding at least part of light within a wavelength range of 700 to 1000 nm can be used.

Moreover, as a structure of the thermochromic film 1, the transparent base material 2 and the optical function layer 3 are made into the hybrid optical function layer (2 + 3) comprised by the same layer, and optical function is used as resin which comprises the transparent base material. using a resin binder contained in the layer, the resin binder, the primary particles VO _S of VO ₂ particles above VO _2, and the secondary particles VO _M of vanadium dioxide particles are dispersed, the transparent base of a single layer You may form the optical function layer which combines a material.

As the optical characteristics of the thermochromic film of the present invention, the visible light transmittance measured by JIS R3106-1998 is preferably 20% or more, more preferably 30% or more, and further preferably 40% or more. is there.

[Component materials of thermochromic film]
Hereinafter, the details of the optical functional layer, which is a component of the thermochromic film of the present invention, a base material provided if necessary, and the near infrared light shielding layer will be described.

(Optical function layer)
The optical functional layer according to the present invention contains at least vanadium dioxide, a water-soluble resin, and a hydrophobic resin.

[Vanadium dioxide]
Vanadium dioxide according to the present invention is an embodiment of vanadium oxide. Vanadium oxide takes various forms in nature, including 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 ³⁺ , V ^Examples of the structure include ₂ O ₃ , V ²⁺ , V ₂ O ₂ , and V. The form changes depending on each 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.

Since VO ₂ exhibiting thermochromic properties (automatic light control) exhibits a monoclinic structure, VO ₂ used in the present invention is a monoclinic crystal.

[Vanadium dioxide particles]
The crystal form of the vanadium dioxide particles according to the present invention is preferably rutile VO ₂ particles (hereinafter also simply referred to as VO ₂ particles) from the viewpoint of efficiently expressing thermochromic properties.

Since the rutile VO ₂ particles have a monoclinic structure below the transition temperature, they are also called M-type. The vanadium dioxide particles according to the present invention may contain VO ₂ particles of other crystal types such as A-type or B-type within a range that does not impair the purpose.

The VO ₂ particles according to the present invention are preferably present in a state where the number average particle diameter of primary particles and secondary particles is less than 500 nm in the optical functional layer.

Although various measurement methods can be applied to the particle diameter measurement method, measurement is preferably performed according to a dynamic light scattering method.

The preferred number average particle diameter of the primary particles and secondary particles in the VO ₂ particles according to the present invention is less than 500 nm, more preferably 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.

The aspect ratio of the VO ₂ particles is preferably in the range of 1.0 to 3.0.

The VO ₂ 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 VO ₂ particles according to the present invention, in addition to VO ₂ , 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 selected element. By adding such an element, it becomes possible to control the phase transition characteristics (particularly the dimming temperature) of the vanadium dioxide particles. The total amount of such additives with respect to the finally obtained vanadium dioxide particles is sufficient to be about 0.1 to 5.0 atomic% with respect to the vanadium (V) atom.

[Water-soluble resin and hydrophobic resin]
The thermochromic film of the present invention is a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, the optical functional layer comprising a water-soluble resin (P ₁ ) and a hydrophobic resin (P ₂ ), and the mass ratio value (P ₁ / P ₂ ) is in the range of 0.3 to 10.0. Preferably, the mass ratio value (P ₁ / P ₂ ) is in the range of 1.0 to 5.0.

Water-soluble resin and hydrophobic resin are considered to function as a binder for the optical functional layer. The water-soluble resin interacts with the vanadium dioxide particles to suppress the aggregation of the particles and stabilize the dispersion, and the hydrophobic resin reduces the water absorption of the resin. It is done.

When the optical functional layer has a mass ratio value (P ₁ / P ₂ ) between the water-soluble resin (P ₁ ) and the hydrophobic resin (P ₂ ) of less than 0.3, the water resistance is good. In addition, it is difficult to stably disperse the vanadium dioxide particles in the thermochromic film, which is not preferable in that the vanadium dioxide particles aggregate and haze increases. On the other hand, when the value of this ratio exceeds 10.0, when the humidity is increased, the hygroscopicity of the thermochromic film is increased, the thermochromic property is deteriorated, and the durability is inferior.

<Hydrophobic resin>
In the present invention, the hydrophobic resin refers to a resin having a dissolution amount of less than 1.0 g at a liquid temperature of 25 ° C. in 100 g of water, more preferably a resin having a dissolution amount of less than 0.5 g. More preferably, the resin has a dissolution amount of less than 0.25 g.

Examples of the hydrophobic resin include olefin polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, poly (4-methyl-1-pentene); (meth) acrylic resin; vinyl chloride, chlorinated vinyl resin, etc. Halogen-containing polymers; styrene polymers such as polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. Polyester; Polyamide such as nylon 6, nylon 66, nylon 610; polyacetal; polycarbonate; urethane resin; polyphenylene oxide; polyphenylene sulfide; Polysulfone; Polyethersulfone; Polyoxybenzylene; Polyamideimide; ABS resin (acrylonitrile-butadiene-styrene resin) or ASA resin (acrylonitrile-styrene-acrylate resin) blended with polybutadiene rubber and acrylic rubber; Cellulose Resin; butyral resin and the like.

Among these, the urethane resin and the (meth) acrylic resin are effective in that the optical functional layer can be given flexibility in addition to the improvement of wet heat durability, and further has an effect of improving the adhesion to the substrate. A urethane resin is particularly preferable.

[Urethane resin]
Urethane resin is a general term for polymers having a urethane bond in the main chain, and is usually obtained by reaction of polyisocyanate and polyol. Examples of the polyisocyanate include TDI (toluene diisocyanate), MDI (diphenylmethane diisocyanate), NDI (naphthalene diisocyanate), TODI (tolidine diisocyanate), HDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), and the like. Examples of the polyol include ethylene glycol, propylene glycol, glycerin and hexanetriol. As the isocyanate used in the present invention, a polymer obtained by subjecting a polyurethane polymer obtained by the reaction of polyisocyanate and polyol to a chain extension treatment to increase the molecular weight can also be used. The polyisocyanate, polyol, and chain extension treatment described above are described in, for example, “Polyurethane Handbook” (edited by Keiji Iwata, Nikkan Kogyo Shimbun, published in 1987).

[(Meth) acrylic resin]
The (meth) acrylic resin is a polymer composed of an acrylic or methacrylic polymerizable monomer. These may be either a homopolymer or a copolymer. Also included are copolymers of these polymers with other polymers. For example, a block copolymer or a graft copolymer. Alternatively, a polymer (possibly a mixture of polymers) obtained by polymerizing a polymerizable monomer having a carbon-carbon double bond in a polyester solution or a polyester dispersion is also included.

Hydrophobic resin, and ease of formation of the optical functional layer, to uniformly disperse the VO ₂ particles in the optical function layer, and in consideration of the homogeneity of such water-soluble resin and a hydrophobic resin, an aqueous emulsion state It is preferable to use what was supplied in (3) with a water-soluble resin.

The resin in the state of an aqueous emulsion may be resin fine particles obtained by keeping an oil-soluble monomer in an emulsion state in an aqueous solution containing a dispersant and emulsion polymerization using a polymerization initiator.

As the dispersant used in the polymerization of the emulsion resin, generally, in addition to a low molecular weight dispersant such as alkyl sulfonate, alkyl benzene sulfonate, diethylamine, ethylenediamine, quaternary ammonium salt, polyoxy Examples thereof include polymer dispersants such as ethylene nonyl phenyl ether, polyethylene ethylene laurate ether, hydroxyethyl cellulose, and polyvinyl pyrrolidone.

Examples of the aqueous emulsion of urethane resin include R-600 (active ingredient concentration: 33%, anionic) in NeoRez (registered trademark) series manufactured by DSM NeoResins ⁺ , UW-1005-E manufactured by Ube Industries, Ltd. (Active ingredient concentration: 29.8% by mass), UW-5002 (Active ingredient concentration: 27.9% by mass), UW-5034-E (Active ingredient concentration: 29.8% by mass), UW-5101 (Active ingredient concentration) : 30% by mass), UW-5502 (active ingredient concentration: 29.9% by mass), and the like. Two or more of these may be used in combination.

<Water-soluble resin>
In the present invention, the water-soluble resin refers to a resin that dissolves 1.0 g or more with respect to 100 g of water at 25 ° C.

Examples of the water-soluble resin include gelatin, graft polymers of gelatin and other polymers, proteins such as albumin and casein, celluloses, sodium alginate, cellulose sulfate, dextrin, dextran, dextran sulfate and other sugar derivatives, Naturally derived materials such as thickening polysaccharides, polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer Or acrylic resins such as acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methyl Styrene-Ak Styrene acrylic acid resin such as sulfonic acid copolymer or 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 And 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 these, a water-soluble resin as defined above can be selected. However, it interacts with VO ₂ particles, and is particularly water-soluble because it can stably disperse VO ₂ particles during coating and drying to prevent aggregation. As the conductive resin, a resin containing a resin having gelatin or an amide group is preferable.

(Resin having an amide group)
Examples of the resin having an amide group include polyvinyl acetamide, polyacrylamide, and a polymer of a monomer having an amide group. Copolymerized products 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.

As the monomer having an amide group, any monomer having an amide group can be used. Examples thereof include N-vinylacetamide, Nn-butoxymethylacrylamide, N-isobutoxymethylacrylamide, and N-methoxymethylacrylamide. Nt-butylacrylamide, N, N'-methylenebisacrylamide, N, N'-methylenebisacrylamide, N-methoxymethylmethacrylamide, Nt-butylacrylamidesulfonic acid and Nt-butylacrylamidesulfonic acid Etc.

The resin having an amide group is preferably polyvinyl acetamide or polyacrylamide. Polyvinylacetamide and polyacrylamide have higher molecular weight and better film elongation and fracture properties, and higher resistance to blowing unevenness during drying. Therefore, the weight average molecular weight may be 100,000 or more and 1,000,000 or less. preferable. Particularly preferably, the resin having an amide group is polyvinyl acetamide. Suitable examples include GE191-103 (manufactured by Showa Denko).

The molecular weight of the resin is a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) and is a value measured as follows. That is, using an apparatus “HLC-8120GPC” (manufactured by Tosoh Corporation) and a column “TSKguardcolumn + TSKgelSuperHZ-M3 series” (manufactured by Tosoh Corporation), while maintaining the column temperature at 40 ° C., tetrahydrofuran (THF) was used as a carrier solvent at a flow rate of 0. The sample to be measured (non-crystalline resin) was dissolved in tetrahydrofuran so as to have a concentration of 1 mg / mL under a dissolution condition in which the measurement sample (noncrystalline resin) was treated for 5 minutes using an ultrasonic disperser at room temperature. A sample solution is obtained by processing with a 2 μm membrane filter, and 10 μL of this sample solution is injected into the apparatus together with the carrier solvent, detected using a refractive index detector (RI detector), and the molecular weight distribution of the measurement sample. A calibration curve measured using monodisperse polystyrene standard particles Is used to calculate. Ten polystyrenes are used for calibration curve measurement.

(gelatin)
As the gelatin applicable to the present invention, various gelatins that have been widely used in the field of silver halide photographic light-sensitive materials can be applied. For example, in addition to acid-processed gelatin and alkali-processed gelatin, production of gelatin is possible. Enzyme-treated gelatin and gelatin derivatives that undergo enzyme treatment in the process, that is, modified by treatment with a reagent that has an amino group, imino group, hydroxy group, carboxy group as a functional group in the molecule and a group obtained by reaction with it. You may have done. The general method for producing gelatin is well known and is described, for example, in T.W. H. James: The Theory of Photographic Process 4th. ed. Reference can be made to descriptions such as 1977 (Macmillan), 55, Scientific Photographic Handbook (above), 72-75 (Maruzen), Fundamental of Photographic Engineering-Silver Salt Photography, 119-124 (Corona). Also, Research Disclosure Magazine Vol. 176, No. And gelatin described in Section IX of 17643 (December, 1978). )
Gelatin having a weight average molecular weight of 5,000 to 200,000 can be used.

Further, if necessary, a gelatin hardener can be added to the coating solution.

[Nitrogen-containing compounds]
The optical functional layer preferably contains a nitrogen-containing compound having a molecular weight in the range of 100 to 10,000. When the molecular weight is 100 or more, the activity is high and the effect as a stabilizer for vanadium dioxide particles is enhanced. Moreover, if molecular weight is 10,000 or less, it will interact with several vanadium dioxide particles, and a favorable stabilization effect will be acquired.

As the nitrogen-containing compound, any nitrogen-containing compound may be used as long as the molecular weight is within the above range, and it is preferable that the nitrogen atom contributes to the adsorptivity to the surface of the vanadium dioxide particles.

Examples of nitrogen-containing compounds include compounds having substituents such as amino groups, imide groups, oxazoline groups, carbodiimide groups, aziridine groups, isocyanate groups, thioisocyanate groups, amide groups, benzimidazole compounds, and imidazole compounds. Illustrated.

In addition, the content of the nitrogen-containing compound is preferably in the range of 1 to 30% by mass with respect to the total mass of the optical functional layer, from the viewpoint that the thermochromic film obtains good thermochromic properties.

The nitrogen-containing compound preferably has at least one cationic group as an adsorbing group adsorbed on the surface of the vanadium dioxide particles. The cationic group is easily adsorbed on the surface of the vanadium dioxide particles, and the nitrogen-containing compound and vanadium dioxide are extremely easily interacted with each other. The cationic group refers to a cationic group or a group that can be derived from a cationic group, such as an amino group (—NH), a monoalkylamino group such as a methylamino group or an ethylamino group, a dimethylamino group or a diethylamino group. Examples thereof include a dialkylamino group, an imino group, a guanidino group, and an imide group. The amino group may be (—NH ₃ ⁺ ) in which a proton is coordinated. Moreover, a nitrogen atom containing silane coupling agent can also be used suitably, and a diamine silane coupling agent and a diisocyanate group containing silane coupling agent can be used. Examples of commercially available products that can be used include KBM-603 and KBE-903 (manufactured by Shin-Etsu Chemical Co., Ltd.).

As the compound having an amino group, polyvalent amines are preferably used. For example, dicyclohexylmethanediamine, isophoronediamine, 4,4′-diphenylmethanediamine, diaminoethane, 1,2- or 1,3- Diaminopropane, 1,2- or 1,3- or 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, piperazine, N, N'-bis- (2-aminoethyl) piperazine Bis- (4-aminocyclohexyl) methane, bis- (4-amino-3-butylcyclohexyl) methane, 1,2-, 1,3- and 1,4-diaminocyclohexane, norbornenediamine, hydrazine, adipic acid diacid Hydrazine or the like can be used alone or in combination of two or more. Moreover, polyethyleneimine etc. can be used as a polyamine type compound, and Epomin SP-012 (made by Nippon Shokubai Co., Ltd.) etc. can be used as a commercial item, for example.

Among the above, the adsorptive group is preferably an amino group, a monoalkylamino group or a dialkylamino group. Furthermore, when the availability of the nitrogen-containing compound is taken into consideration, the nitrogen-containing compound is more preferably one having an amino group.

The carbodiimide referred to in the present invention includes a compound having a plurality of carbodiimide structures in the molecule (hereinafter also referred to as “carbodiimide compound”). As the carbodiimide compound, any compound having a plurality of carbodiimide groups in the molecule can be used without particular limitation.

Polycarbodiimide is usually synthesized by condensation reaction of organic diisocyanate. Here, the organic group of the organic diisocyanate used for the synthesis of the compound having a plurality of carbodiimide structures in the molecule is not particularly limited, either aromatic, aliphatic, or a mixture thereof can be used. An aliphatic system is particularly preferred from the viewpoint of reactivity.

As the synthetic raw material, organic isocyanate, organic diisocyanate, organic triisocyanate, etc. are used. As examples of organic isocyanates, aromatic isocyanates, aliphatic isocyanates, and mixtures thereof can be used.

Specifically, 4,4'-diphenylmethane diisocyanate, 4,4-diphenyldimethylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane Diisocyanate, xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3-phenylene diisocyanate, etc. are used. As organic monoisocyanates, isophorone isocyanate, phenyl isocyanate are used. Cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate and the like are used.

As the carbodiimide compound used in the present invention, for example, carbodilite V-02-L2, V-02, V-04 (manufactured by Nisshinbo Chemical Co., Ltd.) and the like are commercially available.

Further, examples of the benzimidazole compound preferably used in the present invention include benzimidazole, 5-methylbenzimidazole, 2-aminobenzimidazole, 5,6-dimethylbenzimidazole, 1-methylbenzimidazole, 2-methylbenzoic acid. Examples include imidazole, 2- (methylthio) benzimidazole, 2-mercaptobenzimidazole, 5-benzimidazolecarboxylic acid, and 5-amino-2-mercaptobenzimidazole. Of these, 5-amino-2-mercaptobenzimidazole, 2-methylbenzimidazole, 5-methylbenzimidazole and the like are preferable.

The above benzimidazole compounds may be used alone or in combination of two or more.

In the present invention, the imidazole compound used as the nitrogen-containing compound is a compound having an imidazole skeleton.

Examples of the imidazole compound preferably used in the present invention include 1-methylimidazole, 1-butylimidazole, 2-methylimidazole, 2-ethylimidazole, 1-methyl-4-phenylimidazole, 4-methyl-2-phenyl. Examples include imidazole, 2-aminoimidazole, 2-mercapto-1-methylimidazole, 2-ethyl-4-methylimidazole, 4-imidazolecarboxylic acid and the like. Of these, 1-methylimidazole, 2-aminoimidazole, 2-mercapto-1-methylimidazole, 2-ethyl-4-methylimidazole, 4-imidazolecarboxylic acid and the like are preferable.

The above imidazole compounds may be used alone or in combination of two or more.

Examples of the material having an amide group include low molecular weight polyacrylamide and polyacetamide. Since these have a low molecular weight, they do not hold as binders for coating films, but they can be adsorbed on fine particles to improve dispersibility and stability.

[Organic metal compound]
The optical functional layer according to the present invention preferably contains an organometallic compound. By including an organometallic compound in the optical functional layer, it is considered that the organometallic compound adsorbs to the vanadium dioxide particles and effectively blocks moisture and oxygen from entering the optical functional layer, thereby further improving wet heat durability. Can do. The addition amount is preferably in the range of 1 to 30% by mass with respect to the total mass of the optical functional layer.

The organometallic compounds used in the present invention are preferably organotin compounds, organoiron compounds, organozinc compounds, organosilane compounds, organotitanium compounds, organozirconium compounds, and organobismuth compounds.

Examples of organotin compounds include dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, dibutyltin diacetoacetonate, tin octylate, tin naphthenate, tin laurate and tin ferzatic acid, and dibutyltin oxide and phthalate. Examples include a reaction product with an acid ester.

Examples of the organic iron compound and the organic zinc compound include tris (acetylacetonato) iron, tris (2,2,6,6-tetramethyl-3,5-heptanedionate) iron, and tris (tetrafluoroacetylacetonate). ) Iron, bis (acetylacetonato) zinc, bis (2,2,6,6-tetramethyl-3,5-heptanedionate) zinc, bis (tetrafluoroacetylacetonato) zinc and the like.

Specific examples of the organic silane compound include, for example, methyltriethoxysilane, trimethylethoxysilane, methyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyltrimethoxysilane, n-butyltrimethoxysilane, and n-butyl. Methyldimethoxysilane, n-butyltrimethoxysilane, isobutyltriethoxysilane, isobutyltrimethoxysilane, hexyltriethoxysilane, hexylmethyldimethoxysilane, hexyltrimethoxysilane, octyltriethoxysilane, octyltrimethoxysilane, decyltriethoxysilane , Decyltriethoxysilane, methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldi Tokishishiran and the like.

Examples of the organic titanium compound include titanium tetraisopropoxide, titanium tetra n-butoxide, titanium tetra i-butoxide, titanium methacrylate triisopropoxide, titanium tetramethoxypropoxide, titanium tetra n-propoxide, titanium tetraethoxide, and titanium. Examples thereof include lactate, titanium bis (ethylhexoxy) bis (2-ethyl-3-hydroxyhexoxide), titanium acetylacetonate, titanate such as tetrabutyl titanate and tetrapropyl titanate, and titanium tetraacetylacetonate.

Examples of the organic zirconium compound include zirconium tetramethoxide, zirconium tetraethoxide, zirconium tetra n-propoxide, zirconium tetra i-propoxide, zirconium tetra n-butoxide, zirconium tetra i-butoxide, zirconium tetra t-butoxide, zirconium di Examples thereof include methacrylate dibutoxide, dibutoxyzirconium bis (ethylacetoacetate), zirconium tetraacetylacetonate and the like.

Examples of the organic bismuth compound include bismuth-tris (neodecanoate), bismuth-tris (2-ethylhexoate), and bismuth octylate.

Of these, the organometallic compound is preferably an organotitanium compound, an organosilane compound, and an organozirconium compound, and more preferably an organotitanium compound.

[Other additives for optical functional layer]
Various additives that can be applied to the optical functional layer used in 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, and JP-A-62-261476, JP-A-57-74192, and JP-A-57-87989. , JP-A-60-127785, JP-A-61-146591, JP-A-1-95091, JP-A-3-13376, etc. Or nonionic surfactants, JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, JP-A-61-242871, and JP-A-4-219266. Optical brighteners, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, etc. Lubricants such as tylene glycol, antiseptics, antifungal agents, antistatic agents, matting agents, heat stabilizers, antioxidants, flame retardants, crystal nucleating agents, inorganic particles, organic particles, thickeners, lubricants, infrared absorption Examples include various known additives such as agents, dyes, and pigments.

(Method for producing aqueous dispersion of vanadium dioxide particles)
In general, synthesis of vanadium dioxide particles, a method of pulverizing the VO ₂ sintered body synthesized by the solid phase method, vanadium pentoxide and (V 2 _O ₅₎ As a raw material, to synthesize the VO ₂ in the liquid phase An aqueous synthesis method in which particles are grown is mentioned.

In the present invention, VO ₂ produced by any method can be applied. A dispersant can be added to VO ₂ produced by any method and prepared as a dispersion in an aqueous system.

The addition amount of the dispersing agent is preferably in the range of 0.1 to 1.0% by mass.

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.

These dispersants without drying the VO ₂ particles in the dispersion by using the, as described in the examples can be prepared optically functional layer forming coating liquid.

By using the coating solution for forming an optical functional layer in this state, an optical functional layer is formed, thereby containing VO ₂ particles having a preferred number average particle size in which the number average particle size of primary particles and secondary particles is less than 500 nm. An optical functional layer can be formed.

Further, as a method for producing VO ₂ particles, if necessary, particles such as fine TiO ₂ that becomes the core of particle growth are added as nucleus particles, and the VO ₂ particles are produced by growing the nucleus particles. You can also.

In order to use the water-soluble resin binder as the resin binder, after prepared as an aqueous dispersion containing the aforementioned VO ₂ particles, without drying the VO ₂ particles of the aqueous dispersion, VO ₂ particles separated It is preferable to prepare a coating solution for forming an optical functional layer by mixing a water-soluble resin solution and an aqueous emulsion containing a hydrophobic resin in a dispersed state.

Next, the details of the method for producing VO ₂ particles by the hydrothermal method suitable for the present invention will be described.

Hereinafter, a manufacturing process of the VO ₂ particles by typical hydrothermal method.

(Process 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. . The substance (I) is not particularly limited as long as it is a compound containing pentavalent vanadium (V). 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 particles, in particular, 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.

(Process 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 reactants, the treatment temperature, the treatment pressure, the treatment time, etc.) are set as appropriate, but the temperature of the hydrothermal reaction treatment is, for example, within the range of 250 to 350 ° C. Preferably, it is in the range of 250 to 300 ° C, more preferably in the range of 250 to 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. The hydrothermal reaction treatment time is preferably in the range of 1 hour to 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.

(Process 3)
If necessary, the surface of the obtained vanadium dioxide particles may be subjected to a coating treatment or a surface modification treatment with a resin. Thereby, the surface of the vanadium dioxide particles is protected, and surface-modified single crystal particles can be obtained. In the present invention, among them, it is a preferable aspect that the surface of the vanadium dioxide particles is coated with the resin binder according to the present invention having a glass transition temperature of 65 ° C. or lower.

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 particles, or a part of the particle surface is covered with the resin. It may be in a state. Preferably, a state where 50% or more of the total area of the particle surface is covered is good, and a state where 80% or more is covered is more preferable.

Through the steps 1 to 3, a dispersion liquid containing VO ₂ -containing single crystal particles having thermochromic properties is obtained.

[VO ₂ grinding method]
There are various methods for making VO ₂ into fine particles, but there are various methods such as bead milling, ultrasonic crushing, and high-pressure homogenizer, and any method can be used to produce VO ₂ particles.

In the bead mill, various beads can be used, but zirconia beads are preferably used from the viewpoint of hardness and price.

[Removal of impurities in aqueous dispersion of vanadium dioxide particles]
Impurities such as residues generated in the synthesis process are contained in the dispersion of vanadium dioxide particles prepared by the aqueous synthesis method. When forming the optical functional layer, these impurities can trigger secondary aggregated particle generation and cause deterioration of the optical functional layer during long-term storage, so it is possible to remove the impurities at the stage of the dispersion. preferable.

As a method for removing impurities in the aqueous dispersion of vanadium dioxide particles, conventionally known means for separating foreign substances and impurities can be applied. For example, the VO ₂ particle aqueous dispersion is subjected to centrifugal separation to obtain vanadium dioxide particles. It is possible to remove the impurities in the supernatant, add and disperse the dispersion medium again, or remove the impurities out of the system using an exchange membrane such as an ultrafiltration membrane. From the viewpoint of preventing aggregation of particles, a method using an ultrafiltration membrane is most preferable.

Examples of the material for the ultrafiltration membrane include cellulose, polyethersulfone, and polytetrafluoroethylene (abbreviation: PTFE). Among these, polyethersulfone and PTFE are preferably used.

<< Method for producing thermochromic film >>
Method for producing thermochromic film of the present invention is a method for manufacturing a thermochromic film producing thermochromic film having an optically functional layer containing vanadium dioxide particles exhibiting thermochromic, hydrophobic resin (P ₂₎ A coating for forming an optical functional layer containing a water-based emulsion containing water and a water-soluble resin (P ₁ ) and having a mass ratio value (P ₁ / P ₂ ) in the range of 0.3 to 10.0 It has the process of apply | coating a liquid, It is characterized by the above-mentioned.

Specifically, it may have a step of producing vanadium dioxide particles by the above-described method for producing vanadium dioxide particles, and a step of preparing a coating solution for forming an optical functional layer containing vanadium dioxide particles and applying the coating solution. it can. Thus, a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties can be produced.

(1: Preparation of coating solution for forming optical functional layer)
Specifically, after producing vanadium dioxide particles by the above production method, a coating solution containing the vanadium dioxide particles is prepared.

The content of vanadium dioxide particles in the coating solution is not particularly limited, but is preferably in the range of 5 to 60% by mass, more preferably 5 to 40% by mass with respect to the total mass of the optical functional layer. Within the range, more preferably within the range of 5 to 30% by mass.

The coating solution for forming an optical functional layer contains an aqueous emulsion containing a hydrophobic resin (P ₂ ) and a water-soluble resin (P ₁ ), and the mass ratio value (P ₁ / P ₂ ) is 0.00. It is within the range of 3 to 10.0.

The optical functional layer forming coating solution may contain various additives in addition to the binder resin. As such an additive, any additive may be used as long as the effects of the present invention are not impaired. For example, ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476, JP-A-57-74192, and 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-61-228771 and 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, Lubricants and other lubricants, antiseptics, antifungal agents, antistatic agents, matting agents, heat stabilizers, antioxidants, flame retardants, crystal nucleating agents, inorganic particles, organic particles, viscosity reducing agents, lubricants, infrared absorption Various known additives such as additives, dyes and pigments can be used.

(2: Application of coating solution for forming optical functional layer)
Next, the optical functional layer can be formed on the substrate by applying the prepared coating solution for forming the optical functional layer on the substrate and subjecting it to a drying treatment or a curing treatment as necessary. . In this way, a thermochromic film can be produced.

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.

(3. High temperature and high humidity treatment process)
The method for producing a thermochromic film of the present invention preferably includes a step of subjecting the applied optical functional layer to a high temperature and high humidity treatment in addition to the step of applying the optical functional layer forming coating solution.

By such high-temperature and high-humidity treatment, the vanadium dioxide particles are separated from the substrate in the thickness direction of the optical functional layer by phase separation of the water-soluble resin and the hydrophobic resin with respect to the thickness n of the optical functional layer. The n / 2 lower layer has a higher structure than the upper layer, prevents the influence of moisture and oxygen, can improve long-term wet heat durability, and allows moisture and oxygen to enter the optical functional layer from the outside. An effect of efficiently blocking intrusion can be expressed. For this reason, it is possible to prevent the thermochromic film from being discolored in a high-temperature and high-humidity environment and from being deteriorated in thermochromic properties. Specifically, it is preferable that 70% by mass or more of the vanadium dioxide particles is unevenly distributed in a range of n / 2 in the thickness direction of the optical functional layer with respect to the thickness n of the optical functional layer.

Such high-temperature and high-humidity treatment can be performed by known heating means and humidifying means. The treatment temperature is preferably 50 to 90 ° C., more preferably 60 to 80 ° C. The treatment time is 10 to 48 hours, more preferably 10 to 24 hours, although it depends on the treatment temperature. Further, the relative humidity is preferably 80 to 95%, more preferably 85 to 90%.

The wet coating method used for forming the optical functional layer is not particularly limited, and for example, a roll coating method, a rod bar coating method, an air knife coating method, a spray coating method, a slide curtain coating method, or US Pat. No. 2,761,419. Examples thereof include a slide hopper coating method and an extrusion coating method described in the specification, US Pat. No. 2,761791.

Whether 70% by mass or more of the vanadium dioxide particles are unevenly distributed can be detected by analyzing the element concentration with a field emission electron microscope.

(Measurement of vanadium dioxide-containing grain content in the direction of the thickness of the optical functional layer)
Using a field emission electron microscope (JEM2001F manufactured by HRTEM JEOL) and EDX (JED-2300T manufactured by JEOL), an ultrathin section of a thermochromic film was obtained with an acceleration voltage of 200 KV, a beam diameter of 1.0 nm, and a thickness of the thermochromic film. In the range of 20 nm in the width direction × 20 nm in the width direction, 90 seconds are integrated per location, and the ratio of the number of atoms of each element is obtained from the mass of each element obtained at each measurement point. The vanadium element concentration distribution curve was obtained with respect to the thickness (n) direction of the optical function layer. In this concentration distribution curve, when the cumulative total (integrated value) of the vanadium element from the substrate side to the thickness n / 2 range is 70% or more with respect to the cumulative total (integrated value) of the entire concentration distribution curve, dioxide dioxide It was determined that 70% by mass or more of the vanadium particles were unevenly distributed on the substrate side.

〔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. “Transparent” in the present invention 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.

The thickness of the transparent 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 transparent substrate is 30 μm or more, wrinkles and the like are less likely to occur during handling, and if the thickness is 200 μm or less, for example, when producing a laminated glass, Followability to the curved glass surface is improved.

The transparent 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.

From the viewpoint of preventing generation of wrinkles in the thermochromic film and cracking of the infrared reflective layer, the transparent substrate preferably has a thermal shrinkage rate in the range of 0.1 to 3.0% at a temperature of 150 ° C., The content is more preferably in the range of 1.5 to 3.0%, and further preferably in the range of 1.9 to 2.7%.

Examples of the resin film applicable to the thermochromic film of the present invention include a polyolefin film (eg, polyethylene, polypropylene, etc.), a polyester film (eg, polyethylene terephthalate, polyethylene naphthalate, etc.), a polyvinyl chloride, a triacetyl cellulose film, etc. And preferably a polyester film or a triacetyl cellulose film.

The polyester film (hereinafter simply referred to as “polyester”) is not particularly limited, but is preferably a polyester having a film-forming property having a dicarboxylic acid component and a diol component as main components. The main constituent dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylethanedicarboxylic acid, Examples thereof include cyclohexane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl thioether dicarboxylic acid, diphenyl ketone dicarboxylic acid, and phenylindane dicarboxylic acid. Examples of the diol component include ethylene glycol, propylene glycol, tetramethylene glycol, cyclohexanedimethanol, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyethoxyphenyl) propane, bis ( 4-Hydroxyphenyl) sulfone, bisphenol fluorene hydroxyethyl ether, diethylene glycol, neopentyl glycol, hydroquinone, cyclohexanediol and the like. Among the polyesters having these as main components, from the viewpoints of transparency, mechanical strength, dimensional stability, etc., dicarboxylic acid components such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, diol components such as ethylene glycol and 1 Polyester having 1,4-cyclohexanedimethanol as the main constituent is preferred. Among these, polyesters mainly composed of polyethylene terephthalate and polyethylene naphthalate, copolymerized polyesters composed of terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and mixtures of two or more of these polyesters are mainly used. Polyester as a constituent component is preferable.

When using a transparent resin film as a transparent substrate, in order to facilitate handling, particles may be included 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. Examples of the method of adding particles include a method of adding particles in a polyester as a raw material, a method of adding directly to an extruder, and the like. Well, you may use two methods together. In the present invention, additives may be added in addition to the above particles as necessary. Examples of such additives include stabilizers, lubricants, cross-linking agents, anti-blocking agents, antioxidants, dyes, pigments, and ultraviolet absorbers.

Further, the transparent resin film may be subjected to relaxation treatment or offline heat treatment in terms of dimensional stability. The relaxation treatment is preferably carried out in the process from the heat setting in the stretching process of the polyester film to the winding in the transversely stretched tenter or after exiting the tenter. The relaxation treatment is preferably performed at a treatment temperature in the range of 80 to 200 ° C., more preferably the treatment temperature is in the range of 100 to 180 ° C. Further, the relaxation rate is preferably within a range of 0.1 to 10% in both the longitudinal direction and the width direction, and more preferably, the relaxation rate is within a range of 2 to 6%. The relaxed substrate is subjected to off-line heat treatment to improve heat resistance and to improve dimensional stability.

The transparent resin film is preferably coated with an undercoat layer coating solution inline 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.

(Near-infrared light shielding layer)
In the thermochromic film of the present invention, in addition to the optical functional layer, a near infrared light shielding layer having a function of shielding at least part of the light wavelength range within the range of 700 to 1000 nm may be provided. .

For details of the near-infrared light shielding layer applicable to the present invention, for example, JP 2012-131130 A, JP 2012-139948 A, JP 2012-185342 A, JP 2013-080178 A. Reference can be made to constituent elements and formation methods described in JP-A-2014-089347.

<< Thermochromic-glass composite >>
As a use of the thermochromic film of this invention, it can be used as a thermochromic composite body provided with the thermochromic film as a component. For example, a laminated glass can be formed by sandwiching a thermochromic film-glass composite formed by laminating a thermochromic film and glass or a pair of glass constituent members with glass. Thermochromic film-glass composite and laminated glass can be used for various applications. For example, it can be used for automobiles, railway vehicles, airplanes, ships and buildings.

Laminated glass can be used for other purposes. The laminated glass is preferably laminated glass for buildings or vehicles. The laminated glass can be used for an automobile windshield, side glass, rear glass, roof glass, or the like.

Examples of the glass member include inorganic glass and organic glass (resin glazing). Examples of the inorganic glass include float plate glass, heat ray absorbing plate glass, polished plate glass, mold plate glass, netted plate glass, lined plate glass, and colored glass such as green glass. The organic glass is a synthetic resin glass substituted for inorganic glass. Examples of the organic glass (resin glazing) include a polycarbonate plate and a poly (meth) acrylic resin plate. Examples of the poly (meth) acrylic resin plate include a polymethyl (meth) acrylate plate. In the present invention, inorganic glass is preferred from the viewpoint of safety when it is damaged by an external impact.

Also, it 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.

When the thermochromic film of the present invention is attached to a window glass or the like, spraying water on the window and attaching the thermochromic film adhesive layer to the wet glass surface, the so-called water application method has been repositioned and repositioned. Etc. Therefore, it is possible to use an acrylic pressure-sensitive adhesive that has a weak adhesive force in the presence of water.

The acrylic pressure-sensitive adhesive used may be either solvent-based or emulsion-based, but is preferably a solvent-based pressure-sensitive adhesive because it is easy to increase the adhesive strength and the like, and among them, those obtained by solution polymerization are preferable. Examples of the raw material for producing such a solvent-based acrylic pressure-sensitive adhesive by solution polymerization include, for example, acrylic acid esters such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and acryl acrylate as main monomers serving as a skeleton, As a comonomer to improve cohesive strength, vinyl acetate, acrylonitrile, styrene, methyl methacrylate, etc., to further promote crosslinking, to give stable adhesive strength, and to maintain a certain level of adhesive strength even in the presence of water Examples of the functional group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, and glycidyl methacrylate. Since the adhesive layer of the laminated film requires a particularly high tack as the main polymer, those having a low glass transition temperature (Tg) such as butyl acrylate are particularly useful.

This adhesive layer contains additives such as stabilizers, surfactants, UV absorbers, flame retardants, antistatic agents, antioxidants, thermal stabilizers, lubricants, fillers, coloring, adhesion modifiers, etc. It can also be made. In particular, when used for window sticking as in the present invention, the addition of an ultraviolet absorber is also effective for suppressing deterioration of the thermochromic film due to ultraviolet rays.

The thickness of the adhesive layer is preferably 1 to 100 μm, more preferably 3 to 50 μm. If it is 1 micrometer or more, there exists a tendency for adhesiveness to improve and sufficient adhesive force is acquired. Conversely, if the thickness is 100 μm or less, not only the transparency of the thermochromic film is improved, but also after the thermochromic film is attached to the window glass, it does not cause cohesive failure between the adhesive layers when peeled off, and adheres to the glass surface. There is a tendency that there is no remaining agent.

Various additives can be added to the pressure-sensitive adhesive, and preferably an ultraviolet absorber and an antioxidant can be contained.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

《Preparation of thermochromic film》
[Preparation of Thermochromic Film 1]
(Preparation of VO ₂ particle aqueous dispersion 1)
Purified water 425 mL, vanadium particles (VO _2, manufactured by Shinko Kagaku) dioxide 74.9g were mixed and 300μm zirconia beads for the bead mill using 200 g, using an Apex mill (manufactured by Kotobuki Industries Co., Ltd.), and milling, A VO ₂ particle aqueous dispersion was prepared.

(Preparation of coating solution 1 for forming an optical functional layer)
The following constituent materials are sequentially added, mixed and dissolved, and the concentration of the aqueous optical functional layer forming coating solution 1 is adjusted with water so that the solid content of the additive is 4% by mass, resulting in the following composition. It was prepared as follows.

VO ₂ particle aqueous dispersion 1 (solvent: water, 3%) as solid content 9.3 parts by mass Polyvinylacetamide (GE191-103, Showa Denko KK) as solid content 60.5 parts by mass Hydrophobic resin: UW-1005E ( Aqueous urethane emulsion (manufactured by Ube Industries) 30.2 parts by mass as solids (formation of optical functional layer)
On a transparent substrate of a polyethylene terephthalate film (Toray U40, double-sided easy-adhesion layer) having a thickness of 50 μm, using an extrusion coater, the optical function layer forming coating solution 1 prepared above has a layer thickness after drying. Wet application was carried out under the condition of 1.5 μm, and then hot air of 90 ° C. was blown for 1 minute to dry to form an optical functional layer, whereby a thermochromic film 1 was produced.

[Preparation of thermochromic film 2]
The thermochromic film 1 was prepared in the same manner as in the thermochromic film 1 except that GE191-053 (manufactured by Showa Denko KK) was used instead of GE191-103.

[Preparation of thermochromic film 3]
The thermochromic film 1 was prepared in the same manner except that the polymer set 305 (polyacrylamide, manufactured by Arakawa Chemical Co., Ltd.) was used instead of the GE191-103.

[Preparation of thermochromic film 4]
A thermochromic film 4 was prepared in the same manner as in the thermochromic film 1 except that G-1419 (gelatin, manufactured by Nitta Gelatin Co., Ltd.) was used instead of GE191-103.

[Preparation of thermochromic film 5]
A thermochromic film 5 was produced in the same manner as in the thermochromic film 1 except that EG-40 (polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Co., Ltd.) was used instead of GE191-103.

[Preparation of thermochromic film 6]
The thermochromic film 1 was prepared in the same manner except that the vinyl 6502 (acrylic emulsion, manufactured by Nippon Synthetic Chemical Co., Ltd.) was used instead of the UW-1005E.

[Preparation of thermochromic film 7]
The thermochromic film 7 was prepared in the same manner as in the thermochromic film 1 except that 5 parts by mass of KBE-903 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added as a nitrogen-containing compound.

[Preparation of thermochromic film 8]
A thermochromic film 8 was prepared in the same manner as in the thermochromic film 7 except that 5 parts by mass of V-02-L2 (Nisshinbo Chemical Co., Ltd.) was added as a nitrogen-containing compound.

[Preparation of thermochromic film 9]
A thermochromic film 9 was prepared in the same manner as in the thermochromic film 7 except that 5 parts by mass of GE191-108 (polyvinylacetamide, Showa Denko) was added as a nitrogen-containing compound.

[Preparation of Thermochromic Film 10]
In the thermochromic film 7, it produced similarly except having changed the hydrophobic resin into 201.7 mass parts, and produced the thermochromic film 10. FIG.

[Preparation of Thermochromic Film 11]
In the thermochromic film 7, it produced similarly except having changed hydrophobic resin into 60.5 mass parts, and produced the thermochromic film 11. FIG.

[Preparation of Thermochromic Film 12]
The thermochromic film 7 was produced in the same manner except that the hydrophobic resin was changed to 12.1 parts by mass, and the thermochromic film 12 was produced.

[Preparation of Thermochromic Film 13]
The thermochromic film 7 was prepared in the same manner except that the hydrophobic resin was changed to 6.1 parts by mass, and the thermochromic film 13 was prepared.

[Preparation of Thermochromic Film 14: Comparative Example 1]
(Preparation of coating solution 2 for forming an optical functional layer)
The following constituent materials are sequentially added, mixed and dissolved, and the concentration of the aqueous optical functional layer forming coating liquid 1 is adjusted with water so that the solid content of the additive is 4% by mass, resulting in the following composition. It was prepared as follows.

VO ₂ particle aqueous dispersion 1 (solvent: water, 3%) 9.3 parts by mass as a solid content Polyvinylacetamide (GE191-103, 5% by Showa Denko KK) 90.7 parts by mass as a solid content 50 μm in thickness On the transparent substrate of a polyethylene terephthalate film (Toray U40, double-sided easy-adhesion layer), using an extrusion coater, the layer thickness after drying of the coating liquid 1 for forming an optical functional layer prepared above is 1.5 μm. Wet application was performed under the conditions, followed by drying by blowing warm air of 90 ° C. for 1 minute to form an optical functional layer, thereby producing a thermochromic film 14.

[Preparation of Thermochromic Film 15: Comparative Example 2]
The thermochromic film 14 was produced in the same manner except that EG-40 was used instead of GE191-103, and the thermochromic film 15 was produced.

[Preparation of Thermochromic Film 16: Comparative Example 3]
A thermochromic film 16 was produced in the same manner as in the thermochromic film 14 except that an aqueous urethane emulsion UW-1005E was used instead of GE191-103.

[Preparation of Thermochromic Film 17: Comparative Example 4]
The thermochromic film 17 was prepared in the same manner except that the thermochromic film 1 was mixed so that 83.7 parts by mass of GE191-103 and 7.0 parts by mass of UW-1005E were mixed.

[Preparation of Thermochromic Film 18: Comparative Example 5]
The thermochromic film 18 was prepared in the same manner except that the thermochromic film 1 was mixed so that GE191-103 was 15.2 parts by mass and UW-1005E was 75.6 parts by mass.

[Preparation of Thermochromic Film 19: Examples]
The thermochromic film 19 was prepared in the same manner as in the thermochromic film 1 except that 10 parts by mass of KBE-803 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added as an organometallic compound.

[Preparation of Thermochromic Film 20: Example]
The thermochromic film 20 was prepared in the same manner as in the thermochromic film 1 except that 10 parts by mass of TC-400 (manufactured by Matsumoto Fine Chemical) was added as an organometallic compound.

[Preparation of Thermochromic Film 21: Examples]
The thermochromic film 21 was prepared in the same manner as in the thermochromic film 1 except that 10 parts by mass of TC-500 (manufactured by Matsumoto Fine Chemical) was added as an organometallic compound.

[Preparation of Thermochromic Film 22: Examples]
The thermochromic film 22 was prepared in the same manner as in the thermochromic film 1 except that 10 parts by mass of ZC-300 (manufactured by Matsumoto Fine Chemical) was added as an organometallic compound.

[Preparation of Thermochromic Film 23: Example]
In the thermochromic film 1, it produced similarly except having added 10 mass parts of KR44 (made by Ajinomoto Fine-Techno) as an organometallic compound, and the thermochromic film 23 was produced.

[Preparation of Thermochromic Film 24: Examples]
A sample prepared by sticking the film made of the thermochromic film 7 to glass before the wet heat test and treating the film at 60 ° C. and 90% RH for 2 days at high temperature and high humidity was used.

Details of the materials used are shown below.
PNVA: Polyvinylacetamide GE191-103: (weight average molecular weight 900000 manufactured by Showa Denko KK)
GE191-053: (weight average molecular weight 1500,000, Showa Denko)
Polymer set 305: polyacrylamide (Arakawa Chemical Co., Ltd., weight average molecular weight 200000)
G-1419: Gelatin (weight average molecular weight 150,000 manufactured by Nitta Gelatin)
PVA: Polyvinyl alcohol EG-40: (Nippon Synthetic Chemical Co., Ltd. weight average molecular weight 240000)
UW-1005E: Aqueous urethane emulsion (manufactured by Ube Industries)
Mobile 6502: (Acrylic emulsion, Nippon Synthetic Chemical Co., Ltd.)
KBE-903: (Molecular weight 221 manufactured by Shin-Etsu Chemical Co., Ltd.)
V-02-L2: (Nisshinbo Chemical Co., Ltd. weight average molecular weight 3000)
GE191-108: (weight average molecular weight 30000 manufactured by Showa Denko KK)
KBE-803: γ-mercaptopropyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)
TC-400: Titanium triethanolamate (Matsumoto Fine Chemical)
TC-500: Titanium diethanolaminate (Matsumoto Fine Chemical)
ZC-300: Zirconium lactate ammonium salt (manufactured by Matsumoto Fine Chemical)
KR44: isopropyl tri (N-aminoethyl-aminoethyl) titanate (manufactured by Ajinomoto Fine Techno)
In Table 1, the weight average molecular weight of the polymer and the molecular weight of the compound are both shown as molecular weight.

<Evaluation of thermochromic film>
The thermochromic films 1 to 24 produced above were evaluated for water resistance and haze after a wet heat test as infrared light transmittance and wet heat durability. Further, the visible light transmittance difference and the color difference were also evaluated as wet heat durability.

[Evaluation of thermochromic properties]
The wavelength at 1500 nm was measured using a spectrophotometer V-670 (manufactured by JASCO Corporation). Moreover, the transmittance | permeability in wavelength 1500nm in 75 degreeC (high temperature) is measured using a heating measuring apparatus, and the transmittance | permeability fall by heating up from 25 degreeC (room temperature) to 75 degreeC (high temperature) Thermochromic properties were evaluated as a difference (%). Further, as a wet heat test, the sample was allowed to stand for 10 days in an environment of 85 ° C. and 85% RH, and the transmittance difference (%) was similarly measured using a spectrophotometer. The larger this value, the better the thermochromic properties.

[Haze]
Using NDH7000 (Nippon Denshoku Co., Ltd.), light was incident from the thermochromic layer forming surface, and the haze value of the light at that time was measured. Furthermore, as a wet heat test, it was left to stand at 85 ° C. and 85% RH for 10 days, and then the haze value was measured. The increase in haze not only impairs transparency, but is considered to be caused by aggregation of VO ₂ particles. In order to obtain a thermochromic film having excellent wet heat durability, only the transmittance difference (%) described above is used. The haze must be good.

〔water resistant〕
The sample was cut into a size of 10 cm × 10 cm, and the increase in mass before and after immersion in water at 23 ° C. for 1 hour was measured, and the following ranks were assigned.
5: Less than 0.10 g 4: 0.10 g or more and less than 0.25 g 3: 0.25 g or more and less than 0.50 g 2: 0.50 g or more and less than 1.00 g 1: 1.00 g or more [Transmittance difference and color difference]
Using a spectrophotometer V-670, the thermochromic film affixed to the glass before being put in an environment of 85 ° C. and 85% RH and after standing in an environment of 85 ° C. and 85% RH for 20 days, the difference in visible light transmittance and color difference (ΔE ^* ab (CIE 1976)) was calculated and given the following rank. The visible light transmittance was calculated according to JIS-A5759_6.3 by measuring a wavelength of 380 to 780 nm using a spectrophotometer (V-670). A smaller change in visible light transmittance difference and color difference is preferable because of good wet heat durability.

(Visible light transmittance difference (ΔVLT))
◎: Less than 3% ○: 3% or more and less than 5% △: 5% or more (color difference (ΔE ^* ab))
○: Less than 3 Δ: 3 or more and less than 5 ×: 5 or more The results are shown in Table 1.

As can be seen from the results in Table 1, the thermochromic film of the present invention is superior in terms of transmittance difference (thermochromic properties), haze, and water resistance before and after standing at 85 ° C. and 85% RH for 10 days. I understood that. Furthermore, it was found that the visible light transmittance difference and the color difference were excellent before and after standing at 85 ° C. and 85% RH for 20 days.

In the thermochromic films 14 and 15 (comparative examples), the initial haze is low, but since the binder is made of only a water-soluble resin, there is no water resistance, and the transmittance difference after 85 ° C. and 85% RH (thermochromic) Property) and haze is high. Since the thermochromic film 16 is made of only a hydrophobic resin, VO ₂ aggregated during drying and the initial haze increased. In the thermochromic film 17, since there were few hydrophobic resins with respect to water-soluble resin, it was a result with insufficient water resistance and 85 degreeC85% RH tolerance. On the other hand, in the thermochromic film 18, since the amount of hydrophobic resin is larger than that of the water-soluble resin, the initial haze is increased.

On the other hand, in the present invention (thermochromic films 1 to 13 and 19 to 24), the initial haze is generally small, and it is considered that the amide group-containing resin suppressed aggregation of VO ₂ . It can also be seen that if the nitrogen-containing compound or organometallic compound in the present invention is added to these, the wet heat durability is remarkably improved. Moreover, it can be seen that the urethane emulsion has better haze and water resistance than the acrylic emulsion, and the urethane emulsion is more effective. It can also be seen that polyvinylacetamide (PNVA) or gelatin having a urethane bond is more useful as the water-soluble resin.

Furthermore, using the sample of the thermochromic film 24 obtained by pasting a film made of the thermochromic film 7 on a glass and treating it at 60 ° C. and 90% RH for 2 days at a high temperature and high humidity, the field emission described above is the cross section before the wet heat test. more than 70% of VO ₂ particles were observed in type electron microscope, to the film of n thermochromic film was found to be unevenly distributed in the range of n / 2 in the thickness direction from the base side.

<< Production of Thermochromic Film-Glass Composite >>
Each of the produced thermochromic films is a transparent adhesive sheet (LUCIACS CS9621T, manufactured by Nitto Denko Corporation) with a size of 15 mm × 20 cm of a 1.3 mm thick glass plate (manufactured by Matsunami Glass Industrial Co., Ltd., “Slide Glass White Edge Polish”). Were bonded together to produce a thermochromic film-glass composite, which was confirmed to exhibit good thermochromic properties.

From the above results, by using the method described in the present invention, a thermochromic film containing vanadium dioxide particles, which exhibits excellent thermochromic properties and excellent durability, and a thermochromic film provided with the thermochromic film as a constituent element. -It was confirmed that a glass composite could be produced.

The thermochromic film of the present invention has excellent wet heat durability and can be used as a thermochromic composite including the thermochromic film as a constituent element. For example, a laminated glass can be formed by sandwiching a thermochromic film-glass composite formed by laminating a thermochromic film and glass or a pair of glass constituent members with glass. Thermochromic film-glass composite and laminated glass can be used for various applications. For example, it can be used for automobiles, railway vehicles, airplanes, ships and buildings.

1 Thermochromic film 2 Transparent base material (base material)
3 Optical functional layer 4 Near-infrared light shielding layer B1 Resin binder VO _S primary particle VO _M secondary particle

Claims

A thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, wherein the optical functional layer contains a water-soluble resin (P 1 ) and a hydrophobic resin (P 2 ), and A thermochromic film having a mass ratio value (P 1 / P 2 ) in the range of 0.3 to 10.0.
The thermochromic film according to claim 1, wherein the hydrophobic resin contains a urethane resin.
The thermochromic film according to claim 1 or 2, wherein the water-soluble resin contains a resin having an amide group.
The thermochromic film according to claim 3, wherein the resin having an amide group is polyvinylacetamide.
The thermochromic film according to any one of claims 1 to 4, wherein the water-soluble resin contains gelatin.
The thermochromic film according to any one of claims 1 to 5, wherein the optical functional layer contains a nitrogen-containing compound having a molecular weight in the range of 100 to 10,000.
A thermochromic film having an optically functional layer containing vanadium dioxide particles exhibiting thermochromic, wherein the optical functional layer contains a water-soluble resin (P 1) and the hydrophobic resin (P 2), the A thermochromic film having a mass ratio value (P 1 / P 2 ) in a range of 0.3 to 10.0 and containing an organometallic compound in the optical functional layer.
The thermochromic film according to claim 7, wherein the organometallic compound is selected from an organosilane compound, an organotitanium compound, and an organozirconium compound.
A thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties on a substrate, wherein the optical functional layer comprises a water-soluble resin (P 1 ) and a hydrophobic resin (P 2 ). And the mass ratio value (P 1 / P 2 ) is in the range of 0.3 to 10.0, and 70% by mass of the vanadium dioxide particles with respect to the thickness n of the optical functional layer. The above is unevenly distributed in the range of n / 2 from the base material side.
A thermochromic film-glass composite comprising the thermochromic film according to any one of claims 1 to 6 and glass laminated.
A method of manufacturing a thermochromic film producing thermochromic film having an optically functional layer containing vanadium dioxide particles exhibiting thermochromic aqueous emulsion and water-soluble resin containing a hydrophobic resin (P 2) (P 1 )), and a step of applying a coating solution for forming an optical functional layer whose mass ratio value (P 1 / P 2 ) is within a range of 0.3 to 10.0. A method for producing a thermochromic film.
A method for producing a thermochromic film for producing a thermochromic film having an optical functional layer containing vanadium dioxide particles exhibiting thermochromic properties, comprising an aqueous emulsion containing a hydrophobic resin (P 2 ) and a water-soluble resin (P 1 ) The manufacturing method of the thermochromic film which has the process of apply | coating the coating liquid for optical function layer formation containing, and the process of carrying out high-temperature high-humidity processing of an optical function layer.