JP5070796B2 - Solar radiation shielding film forming coating solution, solar radiation shielding film, and substrate having solar radiation shielding function - Google Patents

Description

  The present invention is applicable to various base materials including glass, plastic, and other transparent base materials that require a solar shading function, and a solar shading film-forming coating solution capable of forming a coating film at room temperature, and The present invention relates to a solar radiation shielding film obtained by curing the solar radiation shielding film-forming coating liquid, and a substrate having a solar radiation shielding function in which the solar radiation shielding film is formed on at least one surface.

  Sun rays can be broadly divided into three types: near infrared rays, visible rays, and ultraviolet rays. Among these, the near-infrared ray (heat ray) in the long wavelength region is light in the wavelength region that is perceived by the human body as thermal energy, and causes a rise in temperature in the room and in the vehicle. On the other hand, ultraviolet rays in the short wavelength region have adverse effects on the human body, such as sunburn, spots, freckles, carcinogenesis, and visual impairment. It also causes a decline.

  Of these unnecessary near infrared rays (heat rays) and harmful ultraviolet rays, in order to shield the near infrared rays (heat rays), a solar radiation shielding film that shields the near infrared rays is formed on the base material and has a solar radiation shielding function. Transparent substrates such as glass substrates, plastic plates, and films are used. Conventionally, as the solar shading film, a solar shading film using a thin film of a metal material having a large amount of conduction electrons such as gold, silver, copper, and aluminum has been used.

  On the other hand, by applying a coating solution containing a solar radiation shielding material on an appropriate transparent substrate, a solar radiation shielding film is formed on the base material, and a transparent substrate having a solar radiation shielding function easily and at low cost. It has also been proposed to manufacture.

For example, in Patent Document 1, hexaboride possesses a large amount of free electrons, and has a maximum transmittance in the visible light region by making these fine particles finely dispersed and close to the visible light region. It has been disclosed that strong plasma reflection occurs in the near-infrared region and the transmittance is minimized.
Patent Document 2 describes a coating solution for forming a solar shading film containing hexaboride as a solar shading material in a binder.

  Patent Document 3 discloses that a fine particle having a solar radiation shielding function is a tungsten oxide represented by the general formula WyOz (W is tungsten, O is oxygen, and 2.0 <z / y <3.0). Fine particles and / or general formula MxWyOz (where M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, One or more elements selected from V, Mo, Ta, and Re, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0) The intermediate layer containing fine particles of the composite tungsten oxide represented by the plate glass Plastics and solar radiation shielding function composed by interposing the two mating plates selected from a plastic containing fine particles having a solar radiation shielding for alignment structures have been proposed.

JP 11-69984 A JP 2001-262061 A International Publication No. WO2005 / 087680A1 Pamphlet

  By the way, when forming a metal thin film as a solar radiation shielding film on a base material, a sputtering method or a vapor deposition method may be used. However, these methods require a large-scale vacuum apparatus, so that the productivity is inferior, the production cost of the solar radiation shielding film is high, and the film formation on a large area is difficult.

On the other hand, a coating liquid containing a solar radiation shielding material may be applied on an appropriate substrate to obtain a solar radiation shielding film. In this method, when a metal material is used as the solar radiation shielding material, oxidation due to fine particles becomes a problem. Therefore, when Au is used as the metal, there is a problem that the raw material cost increases. Further, when hexaboride is used as the solar shading material, there is a problem that when the addition amount of hexaboride is increased in order to obtain an excellent solar shading ability, the visible light transmittance is lowered.
Further, in any solar radiation shielding film, it has been required to maintain the same excellent mechanical strength after solving the above-mentioned problems.

  The object of the present invention has been made in consideration of the above-mentioned situation, can be applied to various existing substrates, can form a coating film at a room temperature of about 20 ° C. to 25 ° C., and has high solar shielding ability. A coating liquid for forming a solar shading film capable of obtaining an excellent film strength, a solar shading film having a high solar shading ability and a high surface hardness, and a transparent substrate having a solar shading function, which are formed by using the coating liquid. An object of the present invention is to provide a substrate having various solar radiation shielding functions.

  As a result of intensive studies, the present inventors have used a reaction product obtained by mixing and reacting a glycidoxypropyl group-containing alkoxysilane and an aminopropyl group-containing alkoxysilane as a binder component, and further, as a near-infrared shielding component, Fine particles comprising at least one selected from a composite tungsten oxide having a diameter of 200 nm or less, and further comprising at least one selected from hexaboride having an average particle diameter of 200 nm or less, antimony having an average particle diameter of 200 nm or less Contains at least one fine particle selected from doped tin oxide (hereinafter sometimes referred to as ATO) and tin-doped indium oxide having an average particle size of 200 nm or less (hereinafter sometimes referred to as ITO). The content of the near-infrared shielding component is 15% by weight or less, of which the composite tongues A coating solution for forming a solar shading film comprising 1 to 10% by weight of oxide and 0.5% by weight or less of the hexaboride fine particles, and applying the coating liquid for forming the solar shading film to an appropriate substrate It discovered that the said objective could be achieved by making it harden | cure above, and came to complete this invention.

（式中、Ｘ１、Ｘ２はメトキシ基、エトキシ基、プロポキシ基、ブトキシ基という、加水分解によってシラノールを生じるアルコキシル基を示し、Ｙ１、Ｙ２はメチル基、エチル基、プロピル基、ブチル基から選択されるアルキル基を示し、ａ、ｂ、ｃ、ｄはそれぞれ１≦ａ≦３、ａ＋ｂ＝３、１≦ｃ≦３、ｃ＋ｄ＝３の関係を満たす数である。） That is, the first configuration is
A coating solution for forming a solar shading film containing a binder component, a near-infrared shielding component, a diluting solvent, and a curing catalyst,
As at least one kind of the binder component, a glycidoxypropyl group-containing alkoxysilane and an aminopropyl group-containing alkoxysilane are reacted in a molar ratio of 2: 1 to 1: 1 in the general formula (Formula 1). Containing the reactants represented,
As the near-infrared shielding component, a general formula MxWyOz having an average particle size of 200 nm or less (where M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, One or more elements selected from Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, W is tungsten, O is oxygen, 0.001 ≦ x / Y ≦ 1, 2.2 ≦ z / y ≦ 3.0) containing at least one fine particle selected from a composite tungsten oxide represented by
Furthermore, as the near-infrared shielding component, fine particles comprising at least one kind selected from hexaboride having an average particle diameter of 200 nm or less, antimony-doped tin oxide having an average particle diameter of 200 nm or less, and tin-doped having an average particle diameter of 200 nm or less Containing at least one kind of fine particles selected from indium oxide,
The content of the near-infrared shielding component is 15% by weight or less, of which the composite tungsten oxide is 1 to 10% by weight and the hexaboride fine particles are 0.5% by weight or less. It is a coating liquid for solar radiation shielding film formation.

(Wherein, X1, X2 is a methoxy group, an ethoxy group, a propoxy group, called butoxy group, an alkoxyl group resulting silanol by hydrolysis, Y1, Y2 are selected from methyl group, an ethyl group, a propyl group, a butyl group A, b, c, and d are numbers satisfying the relationship of 1 ≦ a ≦ 3, a + b = 3, 1 ≦ c ≦ 3, and c + d = 3, respectively.

The second configuration is
The coating liquid for forming a solar shading film according to the first configuration, wherein the composite tungsten oxide fine particles have any one or more of hexagonal, tetragonal, and cubic crystal structures. This is a coating solution for forming a solar shading film.

The third configuration is
The coating liquid for forming a solar radiation shielding film according to the first or second configuration, wherein the M element is selected from Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn. A coating solution for forming a solar shading film, wherein the coating liquid is one or more elements.

The fourth configuration is
The coating liquid for solar radiation shielding film formation according to any one of the first to third configurations, wherein the near-infrared shielding component is contained in an amount of 1 to 10% by weight, and the binder component is contained in an amount of 10 to 40% by weight. A coating solution for forming a solar shading film.

The fifth configuration is
A coating solution for forming a solar radiation shielding film according to any one of the first to fourth configurations,
Furthermore, it is a coating solution for forming a solar shading film characterized by containing one or more kinds of organic ultraviolet absorbers selected from benzophenone series, benzotriazole series, or a mixture thereof.

The sixth configuration is
It is a coating liquid for solar radiation shielding film formation according to any one of the first to fifth configurations,
Further, the solar radiation is characterized in that it contains at least one inorganic ultraviolet shielding component selected from CeO ₂ , ZnO, Fe ₂ O ₃ , and FeOOH as an ultraviolet absorber and fine particles having an average particle size of 100 nm or less. This is a coating solution for forming a shielding film.

The seventh configuration is
A solar shading film characterized in that the solar shading film forming coating solution described in any of the first to sixth configurations is hardened.

The eighth configuration is
The solar radiation shielding film according to the seventh configuration is a base material having a solar radiation shielding function, wherein the solar radiation shielding film is formed on at least one surface and has transparency.

  The solar shading film-forming coating solution according to any one of the first to sixth configurations can be cured even at room temperature, and in addition to the composite tungsten oxide having an average particle size of 200 nm or less, At least one selected from hexaboride having a particle size of 200 nm or less, ATO having an average particle size of 200 nm or less, and at least one fine particle of ITO having an average particle size of 200 nm or less are mixed and used. A solar radiation shielding film having a shielding ability and surface strength can be formed.

As described above, the solar radiation shielding film according to the seventh configuration is at least one selected from hexaboride having an average particle size of 200 nm or less in addition to the composite tungsten oxide having an average particle size of 200 nm or less. , ATO having an average particle diameter of 200 nm or less, and at least one kind of fine particles of ITO having an average particle diameter of 200 nm or less are mixed and used, and a part of the addition amount of the composite tungsten oxide is hexaboride, ATO, ITO By substituting with the fine particles, the color tone of the film can be widely controlled. Specifically, lanthanum hexaboride (hereinafter referred to as LaB ₆ ) is a near-infrared shielding material having a green color tone, ATO having a neutral color tone, and ITO having a light blue color tone. The shielding film can control the color tone of the film widely and has a high solar shielding ability. Furthermore, it has high mechanical strength.

  The base material having the solar radiation shielding function described in the eighth configuration is a base material provided with a solar radiation shielding film having high solar radiation shielding ability, mechanical strength, and transparency.

Hereinafter, embodiments of the present invention will be described in detail.
The solar shading film-forming coating liquid of the present embodiment comprises a binder component, a near infrared shielding component, a diluting solvent, a curing catalyst, and an ultraviolet absorber. Therefore, 1. 1. near infrared shielding component; 2. Manufacturing method of near-infrared shielding component (composite tungsten oxide fine particles); 3. Addition method of near-infrared shielding component 4. binder component, 5. production method of binder component; 6. Diluent solvent, Curing catalyst, 8. 8. UV absorber, Preparation of coating solution for formation of solar shading film, 10. The formation of the solar radiation shielding film and the base material having the solar radiation shielding function will be described in this order.

1. Near-infrared shielding component The near-infrared absorbing material used as the near-infrared shielding component in the present embodiment includes fine particles of composite tungsten oxide having an average dispersed particle diameter of 200 nm or less.
The composite tungsten oxide has the general formula MxWyOz (where the M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, One or more elements selected from Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, .2 ≦ z / y ≦ 3.0), and functions effectively as a near-infrared absorbing component because a sufficient amount of free electrons are generated.

  The fine particles of the composite tungsten oxide represented by the general formula MxWyOz are selected from the hexagonal, tetragonal, and cubic crystals because they have excellent durability when they have a hexagonal, tetragonal, or cubic crystal structure. Preferably it contains one or more crystal structures. Further, for example, in the case of composite tungsten oxide fine particles having a hexagonal crystal structure, preferable M elements include Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn. Examples thereof include composite tungsten oxide fine particles containing one or more elements selected from elements.

At this time, the addition amount x of M element to be added is preferably 0.001 or more and 1.0 or less in terms of x / y, more preferably around 0.33. This is because the value of x calculated theoretically from the hexagonal crystal structure is 0.33, and preferable optical characteristics can be obtained with the addition amount before and after this value. On the other hand, the abundance of oxygen is preferably 2.2 or more and 3.0 or less in terms of z / y. Typical examples include Cs _0.33 WO ₃ , Rb _0.33 WO ₃ , K _0.33 WO ₃ , Ba _0.33 WO _{3, and the} like, but useful as long as y and z fall within the above ranges. Infrared absorption characteristics can be obtained.

  The composite tungsten oxide fine particles described above may be used alone, but it is also preferable to use a mixture of two or more. According to the experiments by the present inventors, in a film in which these fine particles are sufficiently finely and uniformly dispersed, the transmittance has a maximum value between wavelengths of 400 to 700 nm and a minimum value between wavelengths of 700 to 1800 nm. Was observed to have. Considering that the visible light wavelength is 380 to 780 nm and the visibility is a bell-shaped peak with a peak at around 550 nm, such a film effectively transmits visible light and effectively uses light of other wavelengths. It can be understood that it absorbs and reflects.

  The average particle diameter of the composite tungsten oxide fine particles is 200 nm or less, preferably 100 nm or less. The reason is that if the average particle size is 200 nm or less, the tendency of aggregation between the fine particles is not strong, so that precipitation of the fine particles in the coating solution can be avoided, and fine particles having an average particle size of 200 nm or less are light scattering. This is because it does not cause a decrease in visible light transmittance.

  The average particle size is preferably 200 nm or less, preferably 100 nm or less. In the current technology, fine particles having a particle size of about 2 nm can be easily produced commercially. The content of the composite tungsten oxide fine particles is preferably 1 to 10% by weight or less. The reason is that when the content is less than 1% by weight, the solar radiation shielding effect is hardly obtained, and when the content exceeds 10% by weight, the strength of the coating film is lowered or a streaky appearance defect occurs in the coating film described later. It is because.

2. Manufacturing method of near-infrared shielding component (composite tungsten oxide fine particles) The composite tungsten oxide fine particles represented by the general formula MxWyOz are obtained by heat-treating a tungsten compound starting material in an inert gas atmosphere or a reducing gas atmosphere. be able to.

  The composite tungsten compound starting material is tungsten trioxide powder, tungsten oxide hydrate, tungsten hexachloride powder, ammonium tungstate powder, or tungsten hexachloride dissolved in alcohol and then dried. Tungsten oxide hydrate powder obtained, or tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride in alcohol and then adding water to precipitate it and drying it It is preferable that it is any one or more selected from tungsten compound powder obtained by drying ammonium aqueous solution and metallic tungsten powder.

  Here, when producing composite tungsten oxide fine particles, tungsten oxide hydrate powder or tungsten compound powder obtained by drying ammonium tungstate aqueous solution is used from the viewpoint of ease of production process. Is more preferable. Furthermore, it is preferable to use an ammonium tungstate aqueous solution or a tungsten hexachloride solution from the viewpoint that each element can be easily and uniformly mixed when the starting material is a solution. By using these raw materials and heat-treating them in an inert gas atmosphere or a reducing gas atmosphere, the composite tungsten oxide fine particles having the above-mentioned particle diameter can be obtained.

  Furthermore, it is preferable that the element M is also soluble in a solvent such as water or an organic solvent. Examples thereof include tungstate, chloride, nitrate, sulfate, oxalate, oxide, and the like containing element M, but are not limited to these and are preferably in the form of a solution.

Here, the heat treatment condition in the inert atmosphere is preferably 650 ° C. or higher. The starting material heat-treated at 650 ° C. or higher has sufficient coloring power and is efficient as composite tungsten oxide fine particles. As the inert gas, an inert gas such as Ar or N ₂ is preferably used. As the heat treatment conditions in the reducing atmosphere, the starting material is first heat-treated at 100 ° C. or more and 650 ° C. or less in the reducing gas atmosphere, and then at a temperature of 650 ° C. or more and 1200 ° C. or less in the inert gas atmosphere. It is better to heat-treat with. The reducing gas at this time is not particularly limited, but H ₂ is preferable. When H ₂ is used as the reducing gas, the volume ratio of H ₂ is preferably 0.1% or more, and more preferably 2% or more, as the composition of the reducing atmosphere. If it is 0.1% or more, the reduction can proceed efficiently.

The raw material powder reduced with hydrogen contains a magnetic phase and exhibits good near-infrared shielding properties, and can be used as near-infrared shielding particles in this state. However, since hydrogen contained in the composite tungsten oxide fine particles is unstable, the application may be limited in terms of weather resistance. Therefore, the composite tungsten oxide fine particles containing hydrogen can be further stabilized by heat treatment at 650 ° C. or higher in an inert atmosphere. The atmosphere during the heat treatment at 650 ° C. or higher is not particularly limited, but N ₂ and Ar are preferable from an industrial viewpoint. By the heat treatment at 650 ° C. or higher, a magnetic phase is obtained in the composite tungsten oxide fine particles, and the weather resistance is improved.

  From the viewpoint of improving the weather resistance, the surface of the composite tungsten oxide fine particles obtained as described above is coated with an oxide containing one or more kinds of metals of Si, Ti, Zr, and Al. preferable. Although the coating method is not particularly limited, it is possible to coat the surface of the composite tungsten oxide fine particles by adding the metal alkoxide to the solution in which the composite tungsten oxide fine particles are dispersed.

3. Method for adding near-infrared shielding component In the present embodiment, in addition to the composite tungsten oxide having an average particle size of 200 nm or less, at least one selected from hexaboride having an average particle size of 200 nm or less, and an average A mixture of at least one kind of fine particles among ATO having a particle size of 200 nm or less and ITO having an average particle size of 200 nm or less is used. By replacing a part of the added amount of the composite tungsten oxide with these fine particles, the color tone of the film can be widely controlled. Specifically, for example, lanthanum hexaboride (hereinafter referred to as LaB ₆ ) is a near-infrared shielding material having a green color tone, ATO having a neutral color tone, and ITO having a light blue color tone.

The hexaboride fine particles, which are near-infrared shielding components added to the composite tungsten oxide fine particles, include CeB ₆ , GdB ₆ , TbB ₆ , DyB ₆ , HoB ₆ , YB ₆ , SmB ₆ , EuB ₆ , ErB ₆ , TmB. ₆ , YbB ₆ , LuB ₆ , SrB ₆ , CrB ₆ , LaB ₆ , PrB ₆ , and NdB ₆ fine particles. These fine particles can be used alone or in admixture of two or more. These hexaboride fine particles are powders colored in dark blue-violet, etc., but the particle size is sufficiently smaller than the visible light wavelength, and when dispersed in a thin film, visible light transmission occurs in the film, but near infrared rays The shielding ability can be kept strong enough.

  According to the experiments of the present inventor, in the film in which the hexaboride fine particles are sufficiently finely and uniformly dispersed, the transmittance has a maximum value between the wavelengths of 400 to 700 nm and the minimum between the wavelengths of 700 to 1800 nm. It was observed to have a value. Considering that the visible light wavelength is 380 to 780 nm and the visibility is a bell-shaped peak with a peak at around 550 nm, such a film effectively transmits visible light and effectively uses light of other wavelengths. It can be understood that it absorbs and reflects.

  The average particle size of the hexaboride fine particles needs to be 200 nm or less, preferably 100 nm or less. The reason is that if the average particle diameter is 200 nm or less, the tendency of aggregation between the fine particles is not strong, and the precipitation of the fine particles is difficult to occur in the coating liquid. Aggregated particles are preferred because they do not cause a decrease in visible light transmittance due to light scattering. The average particle size is preferably as small as 200 nm or less, preferably 100 nm or less, but the minimum particle size that can be produced commercially with the current technology is at most about 2 nm.

  In addition, the ITO fine particles and ATO fine particles used in the present embodiment hardly absorb or reflect light in the visible light region, and have large reflection / absorption due to plasma resonance in the wavelength region of 1000 nm or more. In these transmission profiles, the transmittance decreases toward the long wavelength side in the near infrared region. On the other hand, the transmission profile of hexaboride has a minimum value in the vicinity of the wavelength of 1000 nm as described above, and the transmittance gradually increases on the longer wavelength side. For this reason, by using a combination of hexaboride and ITO or ATO, it becomes possible to shield the heat rays in the near infrared region without reducing the visible light transmittance, rather than using each of them alone. Heat ray shielding characteristics are improved.

  ITO fine particles and ATO fine particles also preferably have an average particle size of 200 nm or less for the same reason as described above. In some applications of the translucent material, an opaque light transmissivity may be required rather than a transparency. In such a case, a configuration in which the particle size is increased to promote scattering is desirable. If the diameter is too large, the infrared absorptivity itself is also attenuated, and therefore an average particle diameter of 200 nm or less is preferable.

  The hexaboride fine particles have a very high heat ray shielding ability per unit weight, and exhibit the same effect at a use amount of 1/30 or less as compared with ITO fine particles and ATO fine particles. Therefore, by adding hexaboride fine particles, a preferable heat ray shielding effect can be obtained even in a small amount, and when used in combination with ITO fine particles or ATO fine particles, these fine particles can be reduced to reduce the cost. . Moreover, since the usage-amount of all the fine particles can be reduced significantly, the physical property of resin which is a base material, especially the fall of impact strength and toughness can be prevented. For these reasons, the content of the hexaboride fine particles is preferably 0.5% by weight or less.

4). Binder component At least one of the binder components used in the present embodiment is a reaction product obtained by mixing and reacting an alkoxysilane containing a glycidoxypropyl group and an alkoxysilane containing an aminopropyl group. Examples of the alkoxysilane containing a glycidoxypropyl group include glycidoxypropyltrimethoxysilane, glycidoxypropylmethyldimethoxysilane, glycidoxypropyltriethoxysilane, and glycidoxypropylmethyldiethoxysilane. Examples of the alkoxysilane containing an aminopropyl group include aminopropyltriethoxysilane and aminopropyltrimethoxysilane.

5. Production method of binder component In the above reaction, the compounding ratio of alkoxysilane containing glycidoxypropyl group and alkoxysilane containing aminopropyl group is preferably 2: 1 to 1: 1 by molar ratio. . If the compounding ratio of alkoxysilane containing glycidoxypropyl group and alkoxysilane containing aminopropyl group is 2: 1 or less in terms of molar ratio, the film will cure quickly and the strength will be strong, and 1: 1 or more. This is because the film does not whiten.

（式中、Ｘ１、Ｘ２はメトキシ基、エトキシ基、プロポキシ基、ブトキシ基などの加水分解によってシラノールを生じるアルコキシル基を示し、Ｙ１、Ｙ２はメチル基、エチル基、プロピル基、ブチル基から選択されるアルキル基を示し、またａ、ｂ、ｃ、ｄはそれぞれ１≦ａ≦３、ａ＋ｂ＝３、１≦ｃ≦３、ｃ＋ｄ＝３の関係を満たす数である。） The basic structure of the reaction product obtained is represented by the following general formula (Formula 2).

(In the formula, X1 and X2 represent alkoxyl groups that generate silanol by hydrolysis of methoxy group, ethoxy group, propoxy group, butoxy group, etc., and Y1 and Y2 are selected from methyl group, ethyl group, propyl group, and butyl group. And a, b, c, and d are numbers satisfying the relationship of 1 ≦ a ≦ 3, a + b = 3, 1 ≦ c ≦ 3, and c + d = 3, respectively.

  In order to obtain the reaction product, aging is required at room temperature for about 2 weeks. Here, the aging time can be shortened by heating after mixing. The heating temperature at that time is preferably 40 to 80 ° C. This is because if the heating temperature is 40 ° C. or higher, the aging time is shortened, and if it is 80 ° C. or lower, the reaction product is not colored.

  As shown in the basic structure of the general formula (Formula 1), the binder component in this embodiment has an alkoxyl group at both ends of the molecule and a flexible methylene chain in the molecule. This alkoxyl group is hydrolyzed at room temperature to produce highly reactive silanol, which can be polymerized by itself or combined with other components by condensation polymerization. In addition, the methylene chain in the molecule absorbs strain during the condensation polymerization and suppresses the generation of cracks in the coating film.

  Furthermore, the curing of the coating solution for forming a solar shading film in the present embodiment occurs by hydrolysis of alkoxyl groups in the binder component and subsequent polymerization by silanol condensation polymerization. The siloxane bond formed at this time is strong, and a firm coating film can be formed.

6). Diluting solvent The diluting solvent in the coating solution for forming the solar shading film is not particularly limited and can be selected according to the coating conditions, coating environment, type of solid content in the coating solution, for example, methanol, ethanol, Various solvents such as alcohols such as isobutyl alcohol, ether alcohols such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, esters such as methyl acetate and ethyl acetate, and ketones such as methyl ethyl ketone and cyclohexanone can be used. Moreover, the said 1 type, or 2 or more types of solvent can also be used in combination according to a use.

7). Curing catalyst Although the above-mentioned binder component is moisture curable, a curing catalyst is added to the coating solution for forming a solar shading film in order to make the curing rate at room temperature practical. As the curing catalyst, boron trifluoride or the like is preferably used. Furthermore, the curing time can be controlled by adjusting the addition amount of the curing catalyst. As a result, the application range of the solar shading film forming coating solution is expanded. Here, the content of the curing catalyst is preferably 0.01 to 3% by weight.

8). Ultraviolet Absorber In order to enhance the ultraviolet shielding ability of the solar radiation shielding film to be formed, the coating liquid for forming the solar radiation shielding film may contain an organic ultraviolet absorber and / or an inorganic ultraviolet radiation shielding component as the ultraviolet absorber.

  As the organic ultraviolet absorber, either or both of a benzophenone-based (for example, benzophenone) and benzotriazole-based (for example, benzotriazole) organic ultraviolet absorber can be contained. 5 to 7 weight% is preferable. If the content of the ultraviolet absorber is 0.5% by weight or more, the ultraviolet shielding ability of the formed solar shielding film is sufficient. On the other hand, if the content is 7% by weight or less, the ultraviolet absorbent is on the surface of the solar shielding film. This is because it is possible to avoid bleeding and clouding of the solar shading film.

Depending on the application, an inorganic ultraviolet shielding component may be included as an ultraviolet absorber. In this case, one or more selected from among CeO ₂ , ZnO, Fe ₂ O ₃ , and FeOOH fine particles having an average particle diameter of 100 nm or less can be selected as the inorganic ultraviolet shielding component. The reason for setting the average particle size to 100 nm or less is that if the particle size is 100 nm or less, the tendency of aggregation between the fine particles is not strong, and it is difficult for the fine particles to settle in the coating solution, and if the particle size is 100 nm or less. This is because light scattering caused by the fine particles does not cause a decrease in visible light transmittance.

  Further, the content of the inorganic ultraviolet shielding component is preferably 0.1 to 5% by weight. If the content of the inorganic ultraviolet shielding component is 0.1% or more, the ultraviolet shielding ability of the formed solar radiation shielding film is sufficiently exerted. On the other hand, if it is 5% by weight or less, visible light resulting from the inorganic ultraviolet shielding component is exhibited. It is because it can avoid that the transmittance | permeability fall and the nonuniformity of a coating film become remarkable.

Further, by selecting Fe ₂ O ₃ and FeOOH fine particles as inorganic ultraviolet shielding components, it is possible to give the coating film a reddish or yellowish color. And these inorganic ultraviolet-ray shielding components have little change with time. In addition, it is so preferable that the average particle diameter of an inorganic ultraviolet-ray shielding component is small. Also in the inorganic ultraviolet shielding component, fine particles having a particle size of up to about 2 nm can be easily produced commercially in the current technology.

9. Preparation of solar shading film-forming coating solution In the preparation of the solar shading film-forming coating solution in this embodiment, the content of the near-infrared shielding component is 15 wt% or less, preferably 1 to 10 wt%. Of these, composite tungsten oxide fine particles are 1 to 10% by weight, hexaboride fine particles are 0.5% by weight or less, and a binder component is added to 10 to 40% by weight. By adding the absorbent in an amount of 0.1 to 7% by weight, adding the curing catalyst in an amount of 0.01 to 3% by weight, and further adding a diluent solvent, the total amount becomes 100% by weight. Weigh and mix as above.

Here, when the content of the near-infrared shielding component is 15% by weight or less, the transparency of the solar radiation shielding film and a good film appearance can be secured. Furthermore, if the content of the near-infrared shielding component is 1% by weight or more, the near-infrared shielding ability of the formed solar radiation shielding film can be sufficiently secured, and if it is 10% by weight or less, the transparency of the solar radiation shielding film is good. The film appearance can be further secured.
Further, if the binder content is 10% by weight or more, the surface hardness of the formed solar shading film can be sufficiently secured, and if it is 40% by weight or less, the viscosity of the coating solution can be prevented from becoming excessively high. Uniform application is easy.
Moreover, if the content of the ultraviolet absorber is 0.1% by weight or more, the ultraviolet shielding ability of the formed solar shading film can be sufficiently secured, and if it is 7% by weight or less, a good film appearance can be secured.

Furthermore, if the content of the curing catalyst is 0.01% by weight or more, an effect of promoting the curing of the formed solar shading film is obtained, and if it is 3% by weight or less, the leveling property of the liquid at the time of application is It is ensured that the mixed coating solution is not cured before coating.
However, since the curing of the binder component starts when the curing catalyst is added to the solar shading film forming coating solution, it is preferably added immediately before the application of the solar shading film forming coating solution.
Further, the curing catalyst includes alcohols such as methanol, ethanol and isobutyl alcohol, ether alcohols such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, esters such as methyl acetate and ethyl acetate, ketones such as methyl ethyl ketone and cyclohexanone. It is preferable to dissolve in advance in various solvents such as This is because, in the form of a solution, it can be easily added and can be made uniform immediately.

10. Base material having solar shading film formation and solar shading function In the present embodiment, the solar shading film forming coating liquid is applied to one or both sides of a predetermined base material such as a transparent base material such as a glass substrate, a plastic plate or a film. By applying to the surface and curing at room temperature, it is possible to form a solar shading film having a high surface hardness and a solar shading ability on the surface of the transparent substrate. The coating method of the solar shading film forming coating solution is not particularly limited, and the processing solution is flat and thin, such as spin coating method, spray coating method, dip coating method, screen printing method, coating method using cloth or brush. Any method can be used as long as it can be applied uniformly. As a result, the productivity of forming the solar shading film was very high.
The obtained solar shading film has a high solar shading function while having high surface hardness and excellent transparency.

  In this embodiment, in addition to the composite tungsten oxide having an average particle size of 200 nm or less, at least one selected from hexaboride having an average particle size of 200 nm or less, ATO having an average particle size of 200 nm or less, A mixture of at least one fine particle of ITO having an average particle size of 200 nm or less is used. By replacing a part of the added amount of the composite tungsten oxide with these fine particles, lanthanum hexaboride has a green color tone, ATO has a neutral color tone, and ITO has a light blue color tone. Therefore, the color tone of the film can be controlled widely.

  Furthermore, the transparent base material on which the solar radiation shielding film is formed on one side or both sides has high mechanical durability and transparency, and has a high solar radiation shielding function. In the case where the solar radiation shielding film contains an ultraviolet absorber, in addition to exhibiting the ultraviolet shielding ability, it is also possible to suppress deterioration of the substrate itself due to ultraviolet rays.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
Table 1 shows an outline of the constituent components of the solar shading film forming coating solution used in the examples and comparative examples, and Table 2 shows the characteristics of the solar shading film formed using the solar shading film forming coating liquid. .

[Example 1]
When 60 g of glycidoxypropyltrimethoxysilane and 40 g of aminopropyltriethoxysilane are mixed, stirred with a magnetic stirrer for 1 hour, and then aged at room temperature for 14 days to produce the desired binder component (hereinafter referred to as “synthetic solution”) 100 g was obtained.
A predetermined amount of an aqueous metatungsten ammonium solution (50 wt% in terms of WO ₃ ) and an aqueous solution of cesium chloride are weighed so that the molar ratio of W and Cs is 1: 0.33, and both solutions are mixed to obtain a mixed solution. Got. This mixed solution was dried at 130 ° C. to obtain a powdery starting material. This starting material was heated at 550 ° C. for 1 hour in a reducing atmosphere (argon / hydrogen = 95/5 volume ratio). Then, once After returning to room temperature, by heating 1 hour at 800 ° C. in an argon atmosphere to prepare a powder of the Cs _0.33 WO _3. The specific surface area of this powder was 20 m ² / g. As a result of identifying the crystal phase of the Cs _0.33 WO ₃ powder by X-ray diffraction, a crystal phase of hexagonal tungsten bronze (composite tungsten oxide fine particles) was observed.

20% by weight of this Cs _0.33 WO ₃ powder, 75% by weight of toluene, and 5% by weight of a dispersing agent were mixed and subjected to dispersion treatment to obtain a dispersion liquid (A liquid) having an average dispersed particle diameter of 80 nm.
7% by weight of LaB ₆ powder, 86% by weight of toluene and 7% by weight of a dispersant were mixed and dispersed to obtain a dispersion liquid (liquid B) having an average particle diameter of 90 nm.
25% by weight of ATO powder, 65% by weight of propylene glycol methyl ether and 10% by weight of a dispersant were mixed and subjected to dispersion treatment to obtain a dispersion liquid (liquid C) having an average particle diameter of 80 nm.
An ITO powder 25% by weight, propylene glycol methyl ether 65% by weight and a dispersing agent 10% by weight were mixed and subjected to dispersion treatment to obtain a dispersion liquid (D liquid) having an average particle diameter of 80 nm.
20 g of synthesis solution, 15 g of solution A, 40 g of propylene glycol monoethyl ether, 5 g of solution B, 5 g of solution C, and 5 g of solution D are mixed and stirred, and boron trifluoride piperidine as a catalyst. 10 g of an isobutyl alcohol solution (concentration: 1% by weight) was added and stirred to prepare a coating solution for forming a solar shading film.

This solar shading film-forming coating solution was applied onto a 3 mm thick soda lime glass substrate using a bar coater and allowed to stand at room temperature to obtain a solar shading film.
The light transmittance in the obtained solar shading film was measured using a spectrophotometer manufactured by Hitachi, Ltd., and the visible light transmittance (τv) and solar transmittance (τe) were calculated according to JIS R 3106. Then, ultraviolet transmittance (τuv) was calculated according to ISO 9050. Further, a wear wheel CS10f was used as a Taber abrasion tester, a wear test was performed at a load of 250 g and 50 rotations, and the surface hardness of the film was evaluated by the amount of change (ΔH) in haze before and after the test. The haze was measured with a reflection / transmittance meter manufactured by Murakami Color Research Laboratory.
The solar radiation shielding film obtained in Example 1 had a τv of 81.5% and a τe of 54.3%, and was found to have visible light permeability and solar radiation shielding ability. τuv was 52.5%. Further, ΔH was 4.8%, and a film having very high surface hardness and good mechanical strength was formed.

[Example 2]
Dispersion treatment was performed by mixing 15% by weight of FeOOH fine particles, 80% by weight of propylene glycol monoethyl ether, and 5% by weight of a dispersant to produce a dispersion liquid (E liquid) having an average dispersed particle diameter of 80 nm.
20 g of the synthetic liquid described in Example 1, 30 g of propylene glycol monoethyl ether, 15 g of liquid A, 5 g of liquid B, 5 g of liquid C, 5 g of liquid D, and 8 g of liquid E In addition, 2 g of benzotriazole-based organic ultraviolet absorber was mixed and stirred, and 10 g of isobutyl alcohol solution of boron trifluoride piperidine (concentration: 1% by weight) was added as a catalyst and stirred to form a solar shading film. A liquid was produced.
Next, a solar radiation shielding film was formed in the same procedure as in Example 1, and the film was evaluated. The solar radiation shielding film obtained in Example 2 had a τv of 77.8% and a τe of 45.6%, and was found to have visible light permeability and a solar radiation shielding ability. τuv was 0.5%, and the ultraviolet light shielding ability was excellent. Further, ΔH was 5.3%, and a film having very high surface hardness and good mechanical strength was formed.

[Comparative Example 1]
For comparison, the same measurement as in Example 1 was performed using only a 3 mm soda lime glass substrate as a sample.
As a result, the soda-lime glass substrate had τv of 90.3%, τe of 87.3%, and τuv of 70.7%.

[Comparative Example 2]
20 g of the synthesis solution described in Example 1, 5 g of isobutyl alcohol, and 65 g of solution A were mixed and stirred, and 10 g of an isobutyl alcohol solution of boron trifluoride piperidine (concentration: 1% by weight) was added as a catalyst. The coating solution for forming a solar shading film was produced by stirring the mixture.
Next, a solar radiation shielding film was formed in the same procedure as in Example 1. However, the solar radiation shielding film obtained in Comparative Example 2 was uneven in density and nonuniform, resulting in streak defects.

[Comparative Example 3]
20 g of the synthesis solution described in Example 1, 2 g of propylene glycol monoethyl ether, 20 g of A solution, 24 g of C solution and 24 g of D solution were mixed and stirred, and boron trifluoride piperidine as a catalyst. 10 g of an isobutyl alcohol solution (concentration: 1% by weight) was added and stirred to prepare a coating solution for forming a solar shading film.
Next, a solar radiation shielding film was formed in the same procedure as in Example 1. However, the solar shading film obtained in Comparative Example 3 was uneven in density and uneven, resulting in streak defects.

[Comparative Example 4]
20 g of the synthesis solution described in Example 1, 30 g of isobutyl alcohol, 37.5 g of propylene glycol monoethyl ether, and 2.5 g of solution A were mixed and stirred, and further boron trifluoride piperidine as a catalyst. The coating liquid for solar radiation shielding film formation was manufactured by adding and stirring 10 g of isobutyl alcohol solutions (concentration: 1 weight%).
Next, a solar radiation shielding film was formed in the same procedure as in Example 1, and the film was evaluated. The solar radiation shielding film obtained in Comparative Example 4 had a τv of 86.7% and a τe of 70.1%. It was found that the solar radiation shielding ability was insufficient although it had visible light permeability. ΔH was 2.8%.

[Comparative Example 5]
50 g of the synthesis liquid described in Example 1, 5 g of isobutyl alcohol, 5 g of propylene glycol monoethyl ether, 15 g of liquid A, 5 g of liquid B, 5 g of liquid C, and 5 g of liquid D The mixture was stirred, and 10 g of an isobutyl alcohol solution of boron trifluoride piperidine (concentration: 1% by weight) was added as a catalyst and stirred to prepare a coating solution for forming a solar shading film.
Next, a solar radiation shielding film was formed in the same procedure as in Example 1, and the film was evaluated. The coating solution for forming a solar shading film obtained in Comparative Example 5 had a very high viscosity and could not be applied uniformly.

[Comparative Example 6]
5 g of the synthesis liquid described in Example 1, 30 g of isobutyl alcohol, 40 g of propylene glycol monoethyl ether, 15 g of liquid A, 5 g of liquid B, 5 g of liquid C, and 5 g of liquid D The mixture was stirred, and 10 g of an isobutyl alcohol solution of boron trifluoride piperidine (concentration: 1% by weight) was added as a catalyst and stirred to prepare a coating solution for forming a solar shading film.
Next, a solar radiation shielding film was formed in the same procedure as in Example 1, and the film was evaluated. The solar radiation shielding film obtained in Comparative Example 6 had a τv of 73.2% and a τe of 36.7%, and was found to have visible light permeability and solar radiation shielding ability. However, ΔH was 25.5% and the surface hardness was very low.

[Comparative Example 7]
A coating solution for forming a solar shading film was produced in the same procedure as in Example 2 except that coarse particles having an average particle diameter of 250 nm were used as Cs _0.33 WO ₃ .
Next, a solar radiation shielding film was formed in the same procedure as in Example 1, and the film was evaluated. The solar radiation shielding film obtained in Comparative Example 7 had a τv of 77.8% and a τe of 48.9%, and was found to have visible light permeability and a solar radiation shielding ability. τuv was 50.5%. However, the scattering of visible light was strong and cloudy, making it unsuitable for practical use. Further, ΔH was 7.5%.

[Comparative Example 8]
20 g of the synthesis solution described in Example 1, 30 g of isobutyl alcohol, 35 g of propylene glycol monoethyl ether, and 5 g of C solution were mixed and stirred, and a boron trifluoride piperidine solution in isobutyl alcohol (as a catalyst) A coating solution for forming a solar shading film was prepared by adding 10 g of (concentration: 1% by weight) and stirring.
Next, a solar radiation shielding film was formed in the same procedure as in Example 1, and the film was evaluated. The solar radiation shielding film obtained in Comparative Example 8 had a τv of 76.8% and a τe of 60.5%, and was found to have visible light permeability and a solar radiation shielding ability. However, compared with Examples 1 and 2, the solar radiation shielding ability became low. Further, ΔH was 3.1%.

Claims (8)

A coating solution for forming a solar shading film containing a binder component, a near-infrared shielding component, a diluting solvent, and a curing catalyst,
As at least one kind of the binder component, a glycidoxypropyl group-containing alkoxysilane and an aminopropyl group-containing alkoxysilane are reacted in a molar ratio of 2: 1 to 1: 1 in the general formula (Formula 1). Containing the reactants represented,
As the near-infrared shielding component, a general formula MxWyOz having an average particle size of 200 nm or less (where M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, One or more elements selected from Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, W is tungsten, O is oxygen, 0.001 ≦ x / Y ≦ 1, 2.2 ≦ z / y ≦ 3.0) containing at least one fine particle selected from a composite tungsten oxide represented by
Furthermore, as the near-infrared shielding component, fine particles comprising at least one kind selected from hexaboride having an average particle diameter of 200 nm or less, antimony-doped tin oxide having an average particle diameter of 200 nm or less, and tin-doped having an average particle diameter of 200 nm or less Containing at least one kind of fine particles selected from indium oxide,
The content of the near-infrared shielding component is 15% by weight or less, of which the composite tungsten oxide is 1 to 10% by weight and the hexaboride fine particles are 0.5% by weight or less. A coating solution for forming a solar shading film.

(Wherein, X1, X2 is a methoxy group, an ethoxy group, a propoxy group, called butoxy group, an alkoxyl group resulting silanol by hydrolysis, Y1, Y2 are selected from methyl group, an ethyl group, a propyl group, a butyl group A, b, c, and d are numbers satisfying the relationship of 1 ≦ a ≦ 3, a + b = 3, 1 ≦ c ≦ 3, and c + d = 3, respectively. It is a coating liquid for solar radiation shielding film formation according to claim 1,
The coating liquid for forming a solar radiation shielding film, wherein the composite tungsten oxide fine particles have any one or more of hexagonal, tetragonal and cubic crystal structures. It is a coating liquid for solar radiation shielding film formation according to claim 1 or 2,
A coating solution for forming a solar radiation shielding film, wherein the M element is one or more elements selected from Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn. It is a coating liquid for solar radiation shielding film formation in any one of Claim 1 to 3,
The near-infrared shielding component is contained in an amount of 1 to 10% by weight, and the binder component is contained in an amount of 10 to 40% by weight. It is a coating liquid for solar radiation shielding film formation in any one of Claim 1 to 4,
Furthermore, the coating liquid for solar radiation shielding film formation containing the 1 or more types of organic ultraviolet absorber selected from a benzophenone series, a benzotriazole type, or these mixtures. It is the coating liquid for solar radiation shielding film formation in any one of Claim 1 to 5,
Further, the solar radiation is characterized in that it contains at least one inorganic ultraviolet shielding component selected from CeO ₂ , ZnO, Fe ₂ O ₃ , and FeOOH as an ultraviolet absorber and fine particles having an average particle size of 100 nm or less. Coating liquid for forming a shielding film.   The solar shading film according to claim 1, wherein the solar shading film forming coating solution is cured.   A substrate having a solar radiation shielding function, wherein the solar radiation shielding film according to claim 7 is formed on at least one side and has transparency.