JP5975292B2 - Heat ray shielding film and heat ray shielding laminated transparent base material - Google Patents

Description

  The present invention relates to a heat ray shielding film having good visible light transmittance and an excellent heat ray shielding function, and a heat ray shielding laminated transparent substrate to which the heat ray shielding film is applied.

  As safety glass used for automobiles or the like, a laminated glass is used in which an intermediate layer containing polyvinyl acetal resin or the like is sandwiched between a plurality of (for example, two) opposing glass plates. Furthermore, the thing which aimed at the reduction | restoration of a cooling load and a human heat feeling by interrupting | blocking the solar energy which injects with the laminated glass which gave the heat ray shielding function to the said intermediate | middle layer is proposed.

  For example, in Patent Document 1, a soft resin layer containing a heat ray shielding metal oxide made of tin oxide or indium oxide having a fine particle size of 0.1 μm or less is sandwiched between two opposing plate glasses, Laminated glass is disclosed.

  In Patent Document 2, Sn, Ti, Si, Zn, Zr, Fe, Al, Cr, Co, Ce, In, Ni, Ag, Cu, Pt, Mn are provided between at least two opposing plate glasses. , Ta, W, V, Mo, metal oxides, metal nitrides, metal sulfides, Sb and F dopants in the metal, or intermediates in which these composites are dispersed Laminated glass with layers sandwiched is disclosed.

In Patent Document 3, fine particles made of TiO ₂ , ZrO ₂ , SnO ₂ , and In ₂ O ₃ and a glass component made of organic silicon or an organic silicon compound are sandwiched between opposing transparent plate-like members. An automotive window glass is disclosed.

  Furthermore, in Patent Document 4, an intermediate layer composed of three layers is provided between at least two opposing transparent glass plates, and Sn, Ti, Si, Zn, Zr, Fe, Al, Cr, Co, In, Ni, Ag, Cu, Pt, Mn, Ta, W, V, Mo metal, metal oxide, metal nitride, metal sulfide, metal A laminated glass is disclosed in which a dope of Sb or F or a composite of these is dispersed and an intermediate layer of the first layer and the third layer is used as a resin layer.

  However, each of the conventional laminated glasses disclosed in Patent Documents 1 to 4 has a problem that the heat ray shielding function is not sufficient when high visible light transmittance is required.

  On the other hand, the applicant forms an intermediate layer having a heat ray shielding function between two sheet glasses, and this intermediate layer is composed of hexaboride fine particles alone, or hexaboride fine particles and ITO fine particles and / or ATO fine particles. And a heat ray-shielding laminated glass comprising a heat ray shielding film containing vinyl resin, or a heat ray containing the fine particles formed on the surface of the intermediate layer facing the inside of at least one plate glass Patent Document 5 discloses a heat ray shielding laminated glass composed of a shielding film and a heat ray shielding film containing a vinyl resin interposed between the two sheet glasses.

  As described in Patent Document 5, the optical characteristics of the laminated glass for heat ray shielding in which hexaboride fine particles alone, or hexaboride fine particles and ITO fine particles and / or ATO fine particles are applied, has a transmittance in the visible light region. In addition, it exhibits strong absorption in the near infrared region and has minimum transmittance. As a result, the heat-shielding laminated glass is improved until the solar radiation transmittance is in the 50% range when the visible light transmittance is 70% or more, as compared with the conventional laminated glasses described in Patent Documents 1 to 4. It was.

On the other hand, in addition to the ITO fine particles, ATO fine particles, and hexaboride fine particles described above, composite tungsten oxide fine particles are known as fine particles having a shielding function in the near infrared region. The present inventors disclosed in Patent Document 6 a laminated glass for heat ray shielding in which a polyvinyl acetal resin is replaced with an ultraviolet curable resin and a heat ray shielding film in which a composite tungsten compound is contained in the ultraviolet curable resin is used as an intermediate layer. Yes.
As a result, the heat-shielding laminated glass is improved until the solar radiation transmittance is around 35% when the visible light transmittance is 70% or more, compared with the conventional laminated glass described in Patent Documents 1 to 5. It was.

JP-A-8-217500 JP-A-8-259279 Japanese Patent Laid-Open No. 4-160041 Japanese Patent Laid-Open No. 10-297945 JP 2001-89202 A JP 2010-202495 A

However, as a result of further studies by the present inventors, the following problems have been found.
The first problem is that in the laminated glass according to the conventional techniques described in Patent Documents 1 to 6, the haze value (cloudiness) is increased due to scattering of visible light by fine particles having a heat ray shielding function. is there. Because of the high haze value, when the laminated glass according to the prior art is used as a member that requires high visibility such as a windshield, when it is irradiated with strong light such as direct sunlight or a headlamp. The problem is that the fine particles strongly scatter in the short wavelength region of visible light and the laminated glass becomes cloudy white (so-called blue haze). Further, there was still room for improvement in the transparency of the laminated glass.

Here, haze and blue haze will be briefly described.
Normal haze is caused by the fact that incident light is scattered by a filler or the like in the medium. When the particle diameter of the filler or the like is larger than 200 nm, a visible light region of 400 nm to 780 nm is caused by geometric scattering or Mie scattering. It is known to scatter the light and become like frosted glass. On the other hand, when the particle size is 200 nm or less, it is known that geometric scattering or Mie scattering is reduced, and most of the scattering follows Rayleigh scattering whose scattering coefficient is defined by the following formula (1).

S = [16π ⁵ r ⁶ / 3λ ⁴ ] · [(m ² −1) / (m ² +2)] ² · [m] (1)
(In the above formula (1), S is the scattering coefficient, λ is the wavelength, r is the particle diameter, m = n ₁ / n ₀ , n ₀ is the refractive index of the substrate, and n ₁ is the refractive index of the dispersed material. .)

The Rayleigh scattering is light scattering by particles having a size smaller than the wavelength of light, and occurs in a transparent liquid or solid, but a typical phenomenon is scattering in a gas.
The Rayleigh scattering is inversely proportional to the fourth power of the wavelength, as is clear from the above equation (1). For this reason, it is presumed that a large amount of blue light having a short wavelength is scattered in the solid and discolored to bluish white. The present inventor believes that the blue light scattering is the cause of the occurrence of blue haze.
Further, even if the light scattering intensity is the same, blue haze may occur depending on the type of heat ray shielding film (for example, the kind of fine particles having a heat ray shielding function contained in the heat ray shielding film, the difference in components, etc.). Occurrence may or may not occur (threshold is different between when blue haze occurs and when it does not occur). Therefore, in each heat ray shielding film, it is necessary to visually confirm in advance the relationship (threshold value) between the value of light scattering intensity and the presence or absence of blue haze.

  The second problem is that when the laminated glass according to the prior art described in Patent Document 6 is exposed to sunlight for a long time, the composite tungsten compound that is a heat ray shielding material is deteriorated and colored, so that the laminated glass In some cases, the visible light transmittance was slightly reduced. That is, the laminated glass according to the prior art still has room for improvement in long-term durability.

  The present invention has been made paying attention to the above problems. The problem to be solved is to provide a heat ray shielding film, a method for producing the same, and a transparent substrate for heat ray shielding, which are excellent in transparency and durability, while exhibiting high heat ray shielding properties. is there.

  In order to solve the above-mentioned problems, the present inventors paid attention to a material that strongly absorbs ultraviolet light having a wavelength of around 400 nm, maintaining transparency and durability while maintaining high heat ray shielding characteristics of the composite tungsten oxide fine particles. We intensively studied how to improve it. As a result, the composite tungsten oxide fine particles strongly absorb ultraviolet light having a wavelength of around 400 nm that has no absorption, and have absorption in a wavelength region that greatly contributes to the calculation of visible light transmittance, that is, a visible light region having a wavelength of 500 nm or more. The inventors have come up with a method of using a combination of composite tungsten oxide fine particles with no UV absorber.

  Hitherto, laminated glass in which an organic ultraviolet absorber is applied to an intermediate film mainly composed of a polyvinyl acetal resin has been proposed (for example, JP-A-2-22151, JP-A-5-301993, JP-A-7-330389, JP-A-8-53427, WO2012 / 23616, etc.). However, in these laminated glasses, the organic ultraviolet absorber is added for the purpose of improving the light resistance of the intermediate film, and suppression of the scattered light of the composite tungsten oxide fine particles has not been considered. For this reason, only organic UV absorbers that absorb ultraviolet light having a wavelength shorter than 400 nm, which causes deterioration of the resin itself, have been studied, and absorption of light in the wavelength region that greatly contributes to the scattered light of composite tungsten oxide particles. Was not enough.

  On the other hand, the present inventors have conceived a configuration in which an ultraviolet absorber that strongly absorbs ultraviolet light having a wavelength of around 400 nm is used in combination with the composite tungsten oxide fine particles with an appropriate concentration ratio. By using this ultraviolet absorber and the composite tungsten oxide fine particle in combination with an appropriate concentration ratio, the ultraviolet absorber absorbs the scattered light in the short wavelength region of the visible light scattered by the composite tungsten oxide fine particle, thereby shielding the heat ray. It has been found that the haze value of the film and the heat ray shielding laminated transparent substrate using the heat ray shielding film is lowered.

  Furthermore, with the above-described configuration, the composite tungsten oxide fine particles are prevented from being deteriorated by shielding the light in the wavelength region of 400 nm or less, which is high energy contained in the sun rays, with an ultraviolet absorber. It was found that the decrease in the transmittance when exposed to water is suppressed.

Specifically, shown by the general formula _M y WO _Z, and a composite tungsten oxide fine particles having a hexagonal crystal structure, wavelength 500nm transmittance is 95% or more, and the wavelength 400nm transmittance of 2% or less UV absorber having a transmittance profile and a plasticizer are kneaded with a polyvinyl acetal resin, and formed into a film by a known method such as an extrusion molding method or a calendar molding method, so that a high visible light region can be obtained. The present inventors have found that it is possible to produce a heat ray shielding film that maintains transparency and has low solar transmittance and is excellent in transparency and durability. The present invention has been completed based on such technical knowledge.

That is, the first invention for solving the above-described problem is
A heat ray shielding film that is a kneaded product of fine particles having a heat ray shielding function, a UV absorber, a resin mainly composed of polyvinyl acetal resin, and a plasticizer , and a molded product of the kneaded product ,
The fine particles having a heat ray shielding function are selected from the general formula M _y WO _Z (where M is selected from Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, Sn, Al, Cu). One or more elements, 0.1 ≦ y ≦ 0.5, 2.2 ≦ z ≦ 3.0), and a composite tungsten oxide fine particle having a hexagonal crystal structure,
The ultraviolet absorbent has a light transmittance of 95% or more at a wavelength of 500 nm and a light transmittance of 2% or less at a wavelength of 400 nm,
A heat ray shielding film characterized in that a weight ratio of the composite tungsten oxide fine particles to the ultraviolet absorber is in the range of (composite tungsten oxide fine particles / ultraviolet absorber) = 70/30 to 1/99.

The second invention is
The heat ray shielding film according to the first invention, wherein the ultraviolet absorber is at least one selected from a benzotriazole ultraviolet absorber, a benzophenone ultraviolet absorber, and a triazine ultraviolet absorber. .

The third invention is
2. The heat ray shielding film according to claim 1, wherein the composite tungsten oxide fine particles are fine particles having an average particle size of 40 nm or less.

The fourth invention is:
A heat ray shielding laminated transparent substrate, wherein the heat ray shielding film according to any one of the first to third inventions is present between at least two or more transparent substrates.

The fifth invention is:
Among the transparent substrates, at least one or more sheets are glass. The heat ray shielding laminated transparent substrate according to the fourth invention.

  According to the present invention, by using a composite tungsten oxide fine particle having a high heat ray shielding effect and an ultraviolet absorber together with a polyvinyl acetal resin as a main component, blue haze is suppressed and excellent optical characteristics are highly durable. A heat ray shielding film exhibiting the properties and a heat ray shielding laminated transparent base material using the heat ray shielding film could be obtained.

It is explanatory drawing which shows the method of measuring the base line of transmitted light intensity using an evaluation apparatus. It is explanatory drawing which shows the method of measuring transmitted scattered light intensity | strength using an evaluation apparatus.

Hereinafter, embodiments of the present invention will be described in detail.
Heat-ray shielding film according to the present invention uses the composite tungsten oxide fine particles as fine particles having heat ray shielding function represented by the general formula M _y WO _Z, and having a hexagonal crystal structure. And in this invention, the said composite tungsten oxide microparticles | fine-particles and a dispersing agent are previously disperse | distributed to some plasticizers added to polyvinyl acetal resin, and a composite tungsten oxide microparticle dispersion liquid is obtained. Alternatively, the composite tungsten oxide fine particles and the dispersant are dispersed in a general organic solvent in advance to obtain a dispersion, and then the organic solvent is removed so that the composite tungsten oxide is contained in the solid dispersant. A composite tungsten oxide fine particle dispersion in which the product fine particles are dispersed is obtained. Then, after kneading the obtained dispersion or dispersion, an ultraviolet absorber, a polyvinyl acetal resin, and a plasticizer, it is formed into a film by a known method such as an extrusion molding method or a calendar molding method. Thus, a heat ray shielding film is obtained.
Hereinafter, for the heat ray shielding film and the heat ray shielding laminated transparent base material according to the present invention, [1] components of the heat ray shielding film, [2] heat ray shielding film, [3] heat ray shielding matched transparent base material, [4] summary, Details will be described in this order.

[1] Constituent components of heat ray shielding film Hereinafter, (1) fine particles having a heat ray shielding function, (2) dispersant, (3) ultraviolet absorber, (4) polyvinyl acetal resin, 5) Plasticizer, (6) Adhesive strength modifier, and (7) Other additives will be described in this order.

(1) Fine particles having a heat ray shielding function The fine particles having a heat ray shielding function according to the present invention are composite tungsten oxide fine particles. Since the composite tungsten oxide fine particles absorb a large amount of light in the near infrared region, particularly a wavelength of 1000 nm or more, the transmitted color tone often has a blue color tone.
The composite tungsten oxide fine particles have a general formula MyWO _Z (where M is one or more selected from Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, Sn, Al, Cu). Element, 0.1 ≦ y ≦ 0.5, 2.2 ≦ z ≦ 3.0), and preferably has a hexagonal crystal structure.

  The particle diameter of the composite tungsten oxide fine particles can be appropriately selected depending on the purpose of use of the heat ray shielding film. For example, when the heat ray shielding film is used for applications requiring transparency, the composite tungsten oxide fine particles preferably have a dispersed particle diameter of 40 nm or less. If the composite tungsten oxide fine particles have a dispersed particle size smaller than 40 nm, light is not completely blocked by scattering, and visibility in the visible light region is maintained, and at the same time, transparency is efficiently maintained. Because you can.

  When the heat ray shielding film or the heat ray shielding laminated transparent base material according to the present invention is applied to an application in which the transparency in the visible light region is particularly important, such as an automobile windshield, the scattering by the composite tungsten oxide fine particles is further performed. It is preferable to consider the reduction. When importance is attached to the scattering reduction, the dispersed particle diameter of the composite tungsten oxide fine particles is 30 nm or less, preferably 25 nm or less.

This is because if the composite tungsten oxide fine particles have a small dispersed particle diameter, light scattering in the visible light region having a wavelength of 400 nm to 780 nm due to geometric scattering or Mie scattering is reduced. By reducing the scattering of the light, it is possible to avoid a situation in which the heat ray shielding film has an appearance like a frosted glass when strong light is irradiated and the clear transparency is lost.
This is because when the dispersed particle diameter of the composite tungsten oxide fine particles is 40 nm or less, the geometric scattering or Mie scattering is reduced and a Rayleigh scattering region is obtained. This is because, in the Rayleigh scattering region, the scattered light decreases in inverse proportion to the sixth power of the particle diameter, so that the scattering is reduced and the transparency is improved as the dispersed particle diameter is decreased. Furthermore, it is preferable that the dispersed tungsten oxide fine particles have a dispersed particle diameter of 25 nm or less because the scattered light is extremely reduced.
As described above, from the viewpoint of avoiding light scattering, it is preferable that the dispersed tungsten oxide fine particles have a small dispersed particle diameter. On the other hand, if the dispersed particle diameter of the composite tungsten oxide fine particles is 1 nm or more, industrial production is easy.

The amount of the composite tungsten oxide fine particles contained in the heat-ray shielding film, per unit area 0.2g ^{/ m 2} ~2.5g ^/ m 2 is desirable.

  Regarding the composite tungsten oxide fine particles described above, (a) components of the composite tungsten oxide fine particles, (b) a method of producing the composite tungsten oxide fine particles, (c) a method of producing the composite tungsten oxide fine particle plasticizer dispersion, (d ) A method for producing a composite tungsten oxide fine particle dispersion will be further described in this order.

(A) Components of composite tungsten oxide fine particles Examples of preferable composite tungsten oxide fine particles include Cs _0.33 WO ₃ , Rb _0.33 WO ₃ , K _0.33 WO ₃ , Ba _0.33 WO _{3 and the} like. I can list them. However, if the values of y and z are within the above ranges, useful heat ray shielding characteristics can be obtained. The addition amount of the additive element M is preferably 0.1 or more and 0.5 or less, and more preferably around 0.33. This is because the value theoretically calculated from the hexagonal crystal structure is 0.33, and preferable optical characteristics can be obtained with the addition amount before and after this. Moreover, about the range of Z, 2.2 <= z <= 3.0 is preferable. This is because, in the composite tungsten oxide material represented by the general formula MyWO _Z , the same mechanism as that of the above-described tungsten oxide material represented by WO _x works. This is because free electrons are supplied by the addition of the element M. However, from the viewpoint of optical characteristics, 2.45 ≦ z ≦ 3.00 is more preferable.

(B) Production Method of Composite Tungsten Oxide Fine Particles Composite tungsten oxide fine particles represented by the general formula MyWOz can be obtained by heat-treating a tungsten compound starting material in an inert gas atmosphere or a reducing gas atmosphere.

First, the tungsten compound starting material will be described.
The tungsten compound starting material is tungsten trioxide powder, tungsten dioxide powder, tungsten oxide hydrate powder, tungsten hexachloride powder, ammonium tungstate powder, or tungsten hexachloride powder 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 and drying it One or more selected from a tungsten compound powder obtained by drying an aqueous ammonium acid solution and a metal tungsten powder, and further comprising a tungsten compound containing element M in the form of a single element or compound as a starting material It is preferable to do.

  Here, in order to produce a starting material in which each component is uniformly mixed at a molecular level, it is preferable to mix each material in the form of a solution, and the tungsten compound starting material containing the element M is water, an organic solvent, or the like. It is preferable that it is soluble in a solvent. Examples include tungstate, chloride, nitrate, sulfate, oxalate, oxide, carbonate, hydroxide, etc. containing element M, but are not limited to these and are in solution form Is preferable.

Next, heat treatment in an inert gas atmosphere or a reducing gas atmosphere will be described. First, the heat treatment condition in an inert gas atmosphere is preferably 400 ° C. or higher. The starting material heat-treated at 400 ° C. or higher is efficient as fine particles having a sufficient near-infrared absorbing power and a heat ray shielding function. 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 400 ° C. or less in the reducing gas atmosphere, and then at a temperature of 400 ° 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. Then, when H ₂ is used as the reducing gas, the composition of the reducing atmosphere, for example, Ar, preferably mixed with 0.1% or more by volume of H ₂ in an inert gas such as N _2, More preferably, 0.2% or more is mixed. H ₂ can be advanced efficiently reduced if more than 0.1% by volume.

  The composite tungsten oxide fine particles according to the present invention are surface-treated and coated with a compound containing at least one selected from Si, Ti, Zr, and Al, preferably with an oxide. To preferred. In order to perform the surface treatment, a known surface treatment may be performed using an organic compound containing one or more selected from Si, Ti, Zr, and Al. For example, the composite tungsten oxide fine particles according to the present invention and an organosilicon compound may be mixed and subjected to a hydrolysis treatment.

Further, from the viewpoint of improving the optical properties of the heat ray shielding film described later, the powder color of the composite tungsten oxide fine particles is the L ^* a ^* b ^* color system recommended by the International Lighting Commission (CIE) ( In the powder color in JISZ8729-2004), it is desirable to satisfy the conditions that L ^* is 25 to 80, a ^* is -10 to 10, and b ^* is -15 to 15. By using the composite tungsten oxide fine particles having the powder color, a heat ray shielding film having excellent optical properties can be obtained.

(C) Method for Producing Composite Tungsten Oxide Fine Particle Plasticizer Dispersion Addition and mixing of composite tungsten oxide fine particles and a dispersant to a plasticizer, and heat ray shielding fine particle-containing plasticizer dispersion using a general dispersion method Can be obtained. At this time, it is preferable that the concentration of the composite tungsten oxide fine particles in the plasticizer is a weight that can be 50% by mass or less. If the concentration of the composite tungsten oxide fine particles in the plasticizer is 50% by mass or less, the fine particles are hardly aggregated, easily dispersed, a sudden increase in viscosity can be avoided, and handling is easy.
A method of uniformly dispersing the composite tungsten oxide fine particles in the plasticizer can be arbitrarily selected from general methods. As specific examples, methods such as a bead mill, a ball mill, a sand mill, and ultrasonic dispersion can be used.

  In addition, when the composite tungsten oxide fine particles are dispersed in the plasticizer, an organic solvent having a boiling point of 120 ° C. or lower may be added as desired. Specific examples include toluene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, isopropyl alcohol, and ethanol, but any boiling point having a boiling point of 120 ° C. or less and capable of uniformly dispersing fine particles having a heat ray shielding function can be used. You can choose.

(D) Method for producing composite tungsten oxide fine particle dispersion The composite tungsten oxide fine particles and the dispersant are added to and mixed with an organic solvent having a boiling point of 120 ° C. or less, and heat ray shielding fine particles are obtained using a general dispersion method. After obtaining the contained dispersion, the organic solvent is removed by a known method, whereby a composite tungsten oxide fine particle dispersion in which the composite tungsten oxide fine particles are dispersed in a solid dispersant can be obtained.

  The method of uniformly dispersing the composite tungsten oxide fine particles in the organic solvent can be arbitrarily selected from general methods. As specific examples, methods such as a bead mill, a ball mill, a sand mill, and ultrasonic dispersion can be used.

  Moreover, as a method for removing the organic solvent from the heat ray shielding fine particle-containing dispersion, a method of drying under reduced pressure is preferable. Specifically, the heat ray shielding fine particle-containing dispersion is dried under reduced pressure while stirring to separate the heat ray shielding fine particle-containing composition and the organic solvent component. Examples of the apparatus used for drying under reduced pressure include a vacuum stirring type dryer, but any apparatus having the above functions may be used, and the apparatus is not particularly limited. Moreover, the pressure of the pressure reduction of a drying process is selected suitably.

  The use of the reduced-pressure drying method is preferable because the removal efficiency of the solvent is improved and the composition containing the heat ray shielding fine particles is not exposed to a high temperature for a long time, so that the dispersed fine particles do not aggregate. Furthermore, productivity is increased, and it is easy to collect the evaporated organic solvent, which is preferable from the environmental consideration.

  As the organic solvent, those having a boiling point of 120 ° C. or less are preferably used. If the boiling point is 120 ° C. or lower, it is easy to remove by a drying step, particularly under reduced pressure. As a result, the removal under reduced pressure drying proceeds rapidly and contributes to the productivity of the heat ray shielding fine particle-containing composition. Furthermore, since the vacuum drying process proceeds easily and sufficiently, it is possible to avoid the excess organic solvent remaining in the composition containing heat ray shielding fine particles according to the present invention. As a result, it is possible to avoid the occurrence of problems such as the generation of bubbles when forming the heat ray shielding film. Specific examples include toluene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, isopropyl alcohol, and ethanol. Any boiling point can be used as long as it has a boiling point of 120 ° C. or lower and can uniformly disperse the composite tungsten oxide fine particles. Can be selected.

(2) Dispersant The dispersant according to the present invention is used for uniformly dispersing the composite tungsten oxide fine particles according to the present invention in a polyvinyl acetal resin.
The dispersant according to the present invention has a thermal decomposition temperature of 200 ° C. or higher measured with a differential thermothermogravimetric simultaneous measurement apparatus (hereinafter sometimes referred to as TG-DTA), and has urethane, acrylic and styrene main chains. It is preferable that it is a dispersing agent which has. Here, the thermal decomposition temperature is a temperature at which weight loss due to thermal decomposition of the dispersant begins in the TG-DTA measurement.
This is because when the thermal decomposition temperature is 200 ° C. or higher, the dispersant does not decompose during kneading with the polyvinyl acetal resin. As a result, it is possible to avoid brown coloration in the heat ray shielding film of the heat ray shielding laminated transparent base material due to decomposition of the dispersant, a decrease in visible light transmittance, and failure to obtain the original optical characteristics.

  In addition, the dispersant is preferably a dispersant having an amine-containing group, a hydroxyl group, a carboxyl group, or an epoxy group as a functional group. These functional groups are adsorbed on the surface of the composite tungsten oxide fine particles, prevent aggregation of the composite tungsten oxide fine particles, and have an effect of uniformly dispersing the fine particles even in the heat ray shielding film. Specific examples include acrylic-styrene copolymer dispersants having a carboxyl group as a functional group, and acrylic dispersants having an amine-containing group as a functional group. The dispersant having a functional group containing an amine is preferably one having a molecular weight Mw of 2,000 to 200,000 and an amine value of 5 to 100 mgKOH / g. Moreover, in the dispersing agent which has a carboxyl group, the thing of molecular weight Mw2000-200000 and an acid value of 1-50 mgKOH / g is preferable.

  The addition amount of the dispersant is desirably in the range of 10 parts by weight to 1000 parts by weight, and more preferably in the range of 30 parts by weight to 400 parts by weight with respect to 100 parts by weight of the composite tungsten oxide fine particles. This is because, if the added amount of the dispersant is in the above range, the composite tungsten oxide fine particles are uniformly dispersed in the polyvinyl acetal resin, and the physical properties of the obtained heat ray shielding film are not adversely affected.

(3) Ultraviolet absorber The optical properties of the ultraviolet absorber used in the present invention include a transmittance of 95% or more at a wavelength of 500 nm of the ultraviolet absorber itself excluding absorption of a medium or a substrate, and a transmittance of a wavelength of 400 nm. Preferably has a transmittance profile of 2% or less. More preferably, the transmittance at a wavelength of 500 nm is 97% or more and the transmittance at a wavelength of 400 nm is 2% or less.
If the transmittance of the ultraviolet absorber at a wavelength of 400 nm is 2% or less, when used in combination with the composite tungsten oxide fine particles, the absorption near the wavelength of 400 nm is sufficiently obtained, and the effect of suppressing blue haze is sufficiently obtained. Further, if the transmittance at a wavelength of 500 nm is 95% or more, the visible light transmittance is retained, and the heat ray shielding characteristics are retained even when compared with the case where the composite tungsten oxide fine particles are used alone.

  Specific examples of the UV absorber used in the present invention include organic UV absorbers such as benzotriazole UV absorbers, benzophenone UV absorbers, and triazine UV absorbers.

The mixing ratio of the composite tungsten oxide fine particles and the ultraviolet absorber is desirably in the range of (composite tungsten oxide fine particles / ultraviolet absorber) = 70/30 to 1/99 by weight ratio. If the addition amount of the ultraviolet absorber is less than 1/99, the ultraviolet absorber does not precipitate from the surface of the obtained heat ray shielding film, and the adhesion between the heat ray shielding film and the transparent substrate can be maintained.
Moreover, if the addition amount of the ultraviolet absorber is larger than 70/30, sufficient light absorption can be obtained in the vicinity of a wavelength of 400 nm, and the addition effect can be obtained.

  The method of adding the ultraviolet absorber to the heat ray shielding film can be added to the polyvinyl acetal resin and the plasticizer together with the composite tungsten oxide fine particle plasticizer dispersion or the composite tungsten oxide fine particle dispersion described above. .

  In any case, it is sufficient that the ultraviolet absorber is present uniformly in the heat ray shielding film, and a method that does not impair the transparency of the obtained heat ray shielding film in the visible light region is suitably used.

(4) Polyvinyl acetal resin As the polyvinyl acetal resin used for the heat ray shielding film according to the present invention, a polyvinyl butyral resin is preferable. Further, in consideration of the physical properties of the heat ray shielding film, a plurality of types of polyvinyl acetal resins having different degrees of acetalization may be used in combination. Furthermore, a copolyvinyl acetal resin obtained by reacting a plurality of types of aldehydes in combination during acetalization can also be preferably used.
Here, the preferable lower limit of the degree of acetalization of the polyvinyl acetal resin is 60%, and the upper limit is 75%.

The polyvinyl acetal resin can be prepared by acetalizing polyvinyl alcohol with an aldehyde.
The polyvinyl alcohol is usually obtained by saponifying polyvinyl acetate. Generally, polyvinyl alcohol having a saponification degree of 80 to 99.8 mol% is used.
Moreover, the preferable minimum of the polymerization degree of the said polyvinyl alcohol is 200, and an upper limit is 3000. When the degree of polymerization is 200 or more, resistance to penetration of the manufactured heat ray shielding laminated transparent base material is maintained, and safety is maintained. On the other hand, if it is 3000 or less, the moldability of the resin film is maintained, the rigidity of the resin film is also maintained in a preferable range, and the workability is maintained.

  The aldehyde is not particularly limited, and generally, an aldehyde having 1 to 10 carbon atoms such as n-butyraldehyde, isobutyraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, acetaldehyde or the like is used. It is done. Of these, n-butyraldehyde, n-hexylaldehyde, and n-valeraldehyde are preferable, and butyraldehyde having 4 carbon atoms is more preferable.

(5) Plasticizer The plasticizer used for the heat ray shielding film mainly composed of the polyvinyl acetal resin according to the present invention is a plasticizer that is a compound of a monohydric alcohol and an organic acid ester, or a polyhydric alcohol organic acid ester compound. Examples thereof include plasticizers that are ester-based, and plasticizers that are phosphoric-based such as organic phosphoric acid-based plasticizers. In particular, a plasticizer that is an ester compound synthesized from a polyhydric alcohol and a fatty acid is preferred.

The ester compound synthesized from a polyhydric alcohol and a fatty acid is not particularly limited. For example, glycols such as triethylene glycol, tetraethylene glycol, and tripropylene glycol, butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid And glycol ester compounds obtained by reaction with monobasic organic acids such as n-octylic acid, 2-ethylhexylic acid, pelargonic acid (n-nonyl acid), and decyl acid. In addition, ester compounds of tetraethylene glycol, tripropylene glycol, and the above-mentioned monobasic organic are also included.
Of these, triethylene glycol fatty acid esters such as triethylene glycol dihexanate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-octanoate, and triethylene glycol di-2-ethylhexanate are suitable. is there. The fatty acid ester of triethylene glycol has various properties such as compatibility with polyvinyl acetal and cold resistance in a well-balanced manner, and is excellent in processability and economy.

  When selecting a plasticizer, pay attention to hydrolyzability. From this viewpoint, triethylene glycol di-2-ethylhexanate, triethylene glycol di-2-ethylbutyrate, and tetraethylene glycol di-2-ethylhexanate are preferable.

(6) Adhesive strength adjusting agent It is also preferable to add an adhesive strength adjusting agent to the heat ray shielding film according to the present invention.
Although the said adhesive force regulator is not specifically limited, An alkali metal salt and / or an alkaline-earth metal salt are used suitably. The acid which comprises the said metal salt is not specifically limited, For example, inorganic acids, such as carboxylic acids, such as octyl acid, hexyl acid, butyric acid, acetic acid, formic acid, or hydrochloric acid, nitric acid, are mentioned. Among the alkali metal salts and / or alkaline earth metal salts, a carboxylic acid magnesium salt having 2 to 16 carbon atoms and a carboxylic acid potassium salt having 2 to 16 carbon atoms are preferable.

  The carboxylic acid magnesium salt and potassium salt of the organic acid having 2 to 16 carbon atoms are not particularly limited, and examples thereof include magnesium acetate, potassium acetate, magnesium propionate, potassium propionate, magnesium 2-ethylbutanoate, and 2-ethylbutane. Potassium acid, magnesium 2-ethylhexanoate, potassium 2-ethylhexanoate and the like are preferably used.

These adhesive strength modifiers may be used alone or in combination of two or more.
In addition, when sodium, potassium, magnesium, calcium, and cerium carboxylates are used as the adhesive strength modifier, the action as an original adhesive strength modifier and the effect of improving the weather resistance of the composite tungsten oxide fine particles are achieved. Can be combined.

(7) Other additives General additives can be further blended into the heat ray shielding film according to the present invention as desired. For example, azo dyes, cyanine dyes, quinoline dyes, perylene dyes, carbon black and the like, which are generally used for coloring thermoplastic resins, are added to give an arbitrary color tone as desired. May be.
In addition, organic UV absorbers such as hindered phenol, phosphorus, hydroxybenzophenone, salicylic acid, and HALS, and inorganic UV absorbers such as zinc oxide, titanium oxide, and cerium oxide are added as UV absorbers. May be.
Furthermore, a coupling agent, surfactant, antistatic agent, etc. can be added as an additive.

[2] Heat ray shielding film The heat ray shielding film according to the present invention comprises the above-described composite tungsten oxide fine particle plasticizer dispersion or composite tungsten oxide fine particle dispersion, an ultraviolet absorber, a polyvinyl acetal resin, and a plasticizer. If desired, it can be obtained by, for example, forming into a film by a known method such as an extrusion molding method or a calendar molding method after mixing and kneading other additives and an adhesive strength adjusting agent.

[3] Heat ray shielding laminated transparent base material The heat ray shielding laminated transparent base material using the heat ray shielding film according to the present invention has various forms.
For example, a heat-shielding laminated transparent substrate using inorganic glass as a transparent substrate is obtained by laminating and integrating at least two opposing inorganic glasses with a heat-shielding film interposed therebetween by a known method. It is done. The obtained heat ray shielding laminated transparent base material can be used mainly as a windshield of an automobile or a window of a building.

Using at least two or more transparent resins as a transparent substrate, the transparent resin and the inorganic glass are used in opposition in the same manner as in the inorganic glass, and a heat ray shielding film is provided between the opposing transparent substrates. A heat ray shielding laminated transparent base material can be obtained by sandwiching and existing. The application of the heat-shielding laminated transparent base material is the same as that when inorganic glass is used.
In particular, when at least one of the transparent base materials is glass, a heat ray shielding laminated transparent base material excellent in mechanical strength is obtained, which is a preferable configuration.
Depending on the application of the heat-shielding transparent substrate, it can be used as a single heat-shielding film, or of course using a heat-shielding film on one or both sides of a transparent substrate such as inorganic glass or transparent resin. is there.

[4] Summary As described above in detail, the composite tungsten oxide fine particle plasticizer dispersion or composite tungsten oxide fine particle dispersion having high heat ray shielding performance according to the present invention, the ultraviolet absorber, and the polyvinyl acetal resin. A heat ray shielding film can be produced by kneading a resin mainly composed of a resin and a plasticizer and further forming into a film by a known method. The heat ray-shielding film is present so as to be sandwiched between a plurality of opposing transparent substrates, thereby maintaining high transmittance in the visible light region and having low solar transmittance, and transparency and durability. It became possible to produce a heat-shielding transparent substrate having excellent properties.

  Further, by combining the composite tungsten oxide fine particles and the ultraviolet absorber having a transmittance profile with a wavelength of 500 nm transmittance of 95% or more and a wavelength of 400 nm transmittance of 2% or less in a predetermined ratio, It became possible to reduce the haze of the heat ray shielding film and the heat ray shielding laminated transparent base material using the heat ray shielding film, and to improve the durability. Furthermore, the generation of blue haze is suppressed by absorbing the wavelength region around 400 nm where the absorption of the composite tungsten oxide fine particles is small, and compared to the case where the composite tungsten oxide fine particles are used alone, It has also become possible to exhibit higher heat ray shielding properties.

  As a result, for example, by mounting the heat ray shielding laminated transparent base material according to the present invention on a vehicle as a windshield, an increase in the temperature in the vehicle in the summer can be suppressed and the load on the air conditioner can be reduced. As a result, it can be expected to contribute to improving fuel economy and reducing greenhouse gas emissions. In particular, it will be possible to reduce the power consumed by the air conditioner and to expect a dramatic increase in mileage by installing the heat-shielding transparent base material on electric vehicles that are expected to rapidly spread in the future. It is expected that it will become an essential member in the future in the design of automobiles.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
Further, the powder color of composite tungsten oxide fine particles in each example (10 ° field of view, light source D65), 400 nm transmittance of ultraviolet absorber, and 500 nm transmittance, and visible light transmittance of the heat-shielded transparent substrate, The solar transmittance and the peak value of the diffuse transmittance were measured using a spectrophotometer U-4000 manufactured by Hitachi, Ltd.

The solar radiation transmittance is an index showing the heat ray shielding characteristics of the heat ray shielding laminated transparent base material, and the peak value of the diffuse transmittance is an index showing the transparency of the heat ray shielding matched transparent base material.
Here, the peak value of the diffuse transmittance will be further described.
The peak value of the diffuse transmittance is obtained by plotting the wavelength vs. diffuse transmittance at a light wavelength of 300 to 800 nm, and having the diffuse transmittance value at the light wavelength at which the diffuse transmittance value is maximized. This is the peak value.

A method for measuring the peak value of the diffuse transmittance will be briefly described with reference to FIGS.
Here, FIG. 1 is an explanatory view showing a method for measuring the transmitted light intensity of the baseline using the evaluation apparatus, and FIG. 2 is an explanatory view showing a method for measuring the transmitted scattered light intensity using the evaluation apparatus. is there.
In the present invention, a standard reflector 5 is installed on the integrating sphere 4 provided in the spectrophotometer shown in FIG. 1, and all light incident from the light source 1 is captured by the integrating sphere 4 in the light receiver 3. And measure the light intensity. The measured value of the light intensity (baseline) at this time is (1).
Next, of the light that has entered from the light source 1 shown in FIG. 2 and has passed through the sample 2 of the heat-shielding transparent substrate installed in front of the integrating sphere 4, the light that has traveled straight through the integrating sphere 4 after transmission is optical trapped. 6, and the light intensity is measured by the light receiver 3 in a state where only the transmitted and scattered light in the sample 2 of the heat-shielding laminated transparent base material is captured by the integrating sphere 4. The measured value of the light intensity at this time is (2).
The value of “measured value (2) ÷ measured value (1)” was taken as the value of the diffuse transmittance measured for the sample of the heat-shielded laminated transparent base material.
Furthermore, the value of the diffuse transmittance was swept in the light wavelength range of 300 to 800 nm to obtain the diffuse transmittance value at each wavelength. Next, the wavelength vs. diffuse transmittance value was plotted, and the diffuse transmittance value at the wavelength of light at which the diffuse transmittance value was maximized was taken as the peak value of the diffuse transmittance.

  On the other hand, in the heat ray shielding film according to the present invention, when the peak value of the diffuse transmittance is 2.5% or less, the blue haze cannot be visually recognized (the threshold is 2.5%). It was done.

  Evaluation of changes in the optical properties of the heat ray shielding film when the transparent base material with heat ray shielding is used for a long time is allowed to stand for 200 hours with a xenon arc lamp type weather resistance tester (xenon weatherometer). Evaluation was made based on the change rate of the visible light transmittance before and after the test. The relationship between the wavelength of the xenon arc lamp of the xenon weatherometer and the spectral radiation intensity (spectral distribution) approximates the spectral distribution of sunlight.

[Example 1]
H ₂ WO ₄ and Cs ₂ CO ₃ were weighed so that Cs / W (molar ratio) = 0.33 and mixed well in an agate mortar to obtain a mixed powder. The mixed powder was heated while supplying 5% H ₂ gas with N ₂ gas as a carrier and subjected to reduction treatment at a temperature of 600 ° C. for 1 hour, and then calcined at 800 ° C. for 30 minutes in an N ₂ gas atmosphere. Thus, composite tungsten oxide fine particles (hereinafter abbreviated as “fine particles a”) were obtained.
The compositional formula of the fine particles a was Cs _0.33 WO ₃ , and the powder colors were L ^* of 35.2853, a ^* of 1.4888, and b ^* of −5.2121.

20% by mass of fine particles a, 10% by mass of an acrylic dispersant having an amine-containing group as a functional group (an amine value of 48 mg KOH / g, an acrylic dispersant having a decomposition temperature of 250 ° C. (hereinafter abbreviated as “dispersant a”)), 70% by mass of triethylene glycol di-2-ethylhexanate (hereinafter abbreviated as “plasticizer a”) was weighed and loaded into a paint shaker containing 0.3 mmφZrO ₂ beads and pulverized and dispersed for 10 hours. As a result, a composite tungsten oxide fine particle plasticizer dispersion (hereinafter abbreviated as dispersion A) was obtained.
Here, the dispersion average particle diameter of the composite tungsten oxide fine particles in the dispersion A was measured with a Nikkiso Microtrac particle size distribution meter, and was 20 nm.

  Benzotriazole-based organic ultraviolet absorber Tinuvin 109 (hereinafter abbreviated as Absorbent A) manufactured by BASF Corporation was diluted with methyl isobutyl ketone (hereinafter abbreviated as MIBK) to a predetermined concentration, and placed in a glass cell. When the optical characteristics were measured (however, only MIBK was put in the glass cell and the baseline was measured), the wavelength 400 nm transmittance was 0.7%, and the wavelength 500 nm transmittance was 97.8%. .

A predetermined amount of dispersion A and absorbent A are added to a composition in which 30% by mass of plasticizer a and 70% by mass of polyvinyl butyral resin are mixed, and the concentration of fine particles a in the composition is 0.15% by mass and absorption. The concentration of the agent A was 1.35% by mass. This composition was kneaded at 200 ° C. using a twin screw extruder, extruded from a T-die, and a heat ray shielding film according to Example 1 was obtained as a 0.7 mm thick sheet by a calendar roll method.
The composite tungsten oxide fine particles and the ultraviolet absorber in the heat ray shielding film according to Example 1 are shown in Table 1.

  The obtained heat ray shielding film was sandwiched between two opposing inorganic glasses and laminated together by a known method to obtain a heat ray shielding laminated transparent substrate according to Example 1.

  As for the optical characteristics of the heat ray shielding laminated transparent base material according to Example 1, the solar radiation transmittance was 42.1% when the visible light transmittance was 78.7%, and the peak value of the diffuse transmittance was 1.0%. It was.

Using a xenon weatherometer, the heat ray shielding laminated transparent substrate according to Example 1 was used as a test sample, and the change in visible light transmittance after 200 hours of the acceleration test was measured. The change in visible light transmittance was -0.8%.
Table 1 shows the optical property test results of the heat-shielding transparent base material.

[Examples 2 to 4]
In the same manner as in Example 1, except that the concentration of the fine particles a and the concentration of the ultraviolet absorber A in the composition of the fine particles a, the acrylic dispersant, the absorbent A and the plasticizer were changed. A heat ray shielding film according to 2 to 4 and a heat ray shielding laminated transparent base material were obtained.
Table 1 shows the concentration of the fine particles a and the concentration of the absorbent A in the compositions according to Examples 2 to 4.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning Examples 2-4 was shown in Table 1.

[Example 5]
Benzophenone-based organic ultraviolet absorber DAINSORB P-6 manufactured by Daiwa Kasei Co., Ltd. (hereinafter abbreviated as “absorbent B”) was used in the same manner as in Example 1, except that the heat-shielding transparent base according to Example 5 was used. The material was obtained.
Absorbent B was diluted with MIBK to a predetermined concentration, and placed in a glass cell to measure optical characteristics ^*. The transmittance of light with a wavelength of 400 nm was 0.4%, and the transmittance of light with a wavelength of 500 nm was 98. .5%.
Table 1 shows the concentration of the fine particles a and the concentration of the absorbent B in the composition according to Example 5.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning Example 5 was shown in Table 1.

[Examples 6 to 8]
Examples 6 to 8 are carried out in the same manner as in Example 5 except that the concentration of the fine particles a and the concentration of the absorbent B are changed in the composition of the fine particles a, the acrylic dispersant, the absorbent B, and the plasticizer. A heat-shielded transparent substrate was obtained.
Table 1 shows the concentration of the fine particles a and the concentration of the absorbent B in the compositions according to Examples 6 to 8.
And the optical characteristic test result of the heat ray shielding laminated transparent base material which concerns on Examples 6-8 was shown in Table 1.

[Example 9]
A heat ray shielding laminated transparent base material according to Example 9 was obtained in the same manner as in Example 2 except that a triazine-based organic ultraviolet absorber BASF Co., Ltd. Tinuvin 400 (hereinafter abbreviated as Absorbent C) was used. .
The absorbent C was diluted with MIBK to a predetermined concentration, and placed in a glass cell to measure the optical characteristics ^{*. As} a result, the transmittance of light with a wavelength of 400 nm was 2.0%, and the transmittance of light with a wavelength of 500 nm was 95. 0.0%.
Table 1 shows the concentration of the fine particles a and the concentration of the absorbent C in the composition according to Example 9.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning Example 5 was shown in Table 1.

[Examples 10 to 13]
Examples 10 to 13 were carried out in the same manner as in Example 1 except that the concentration of the fine particles a and the concentration of the absorbent A were changed in the composition of the fine particles a, the acrylic dispersant, the absorbent A and the plasticizer. The heat ray shielding laminated transparent base material which concerns on was obtained.
Table 1 shows the concentration of the fine particles a and the concentration of the absorbent A in the compositions according to Examples 10 to 13.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning Examples 10-13 was shown in Table 1.

[Example 14]
RbNO ₃ was dissolved in water and added to H ₂ WO ₄ to obtain Rb / W (molar ratio) = 0.33. The dried product was heated while supplying 2% H ₂ gas with N ₂ gas as a carrier, baked for 30 minutes at a temperature of 800 ° C., and then baked for 90 minutes at 800 ° C. in an N ₂ gas atmosphere at the same temperature. Thus, composite tungsten oxide fine particles (hereinafter abbreviated as fine particles b) were obtained.
The composition formula of the fine particles b was Rb _0.33 WO ₃ , the powder color L ^* was 36.3957, a ^* was −0.2399, and b ^* was −3.8335.

20% by mass of fine particles b, 10% by mass of dispersant a, and 70% by mass of plasticizer a were weighed. These were loaded into a paint shaker containing 0.3 mmφZrO ₂ beads and pulverized and dispersed for 10 hours to obtain a composite tungsten oxide fine particle plasticizer dispersion (hereinafter abbreviated as dispersion B). Here, the dispersion average particle size of the composite tungsten oxide fine particles in the dispersion B was measured with a Nikkiso Microtrac particle size distribution meter, and found to be 24 nm.

  A predetermined amount of dispersion A and absorbent A are added to a composition in which 30% by mass of plasticizer a and 70% by mass of polyvinyl butyral resin are mixed, and the concentration of fine particles a in the composition is 0.15% by mass and absorption. The concentration of the agent A was 0.35% by mass. This composition was kneaded at 200 ° C. using a twin screw extruder, extruded from a T die, and a heat ray shielding film according to Example 14 was obtained as a sheet having a thickness of 0.7 mm by a calender roll method.

  The obtained heat ray shielding film was sandwiched between two opposing inorganic glasses and laminated together by a known method to obtain a heat ray shielding laminated transparent base material according to Example 14.

  As shown in Table 1, the optical characteristics of the heat-shielded transparent base material are as follows. The solar transmittance when the visible light transmittance is 78.9% is 42.5%, and the peak value of the diffuse transmittance is 1.2%. Met.

Using a xenon weatherometer, the heat ray shielded transparent base material was used as a test sample, and the change in visible light transmittance after 200 hours of the acceleration test was measured. The change in visible light transmittance was -1.5%.
Table 1 shows the concentration of the fine particles b and the concentration of the absorbent A in the composition according to Example 14.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning Example 14 was shown in Table 1.

[Examples 15 to 17]
Examples 15 to 17 were carried out in the same manner as in Example 14 except that the concentration of the fine particles b and the concentration of the absorbent A in the composition of the fine particles b, the acrylic dispersant, the absorbent A and the plasticizer were changed. The heat ray shielding laminated transparent base material which concerns on was obtained.
Table 1 shows the concentration of the fine particles b and the concentration of the absorbent A in the compositions according to Examples 15 to 17.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning Examples 15-17 was shown in Table 1.

[Comparative Examples 1-4]
Heat ray shielding according to Comparative Examples 1 to 4 in the same manner as in Example 1 except that the concentration of the fine particles a in the composition of the fine particles a, the acrylic dispersant and the plasticizer was changed and no ultraviolet absorber was added. A laminated transparent substrate was obtained.
Table 1 shows the concentration of the fine particles a in the compositions according to Comparative Examples 1 to 4.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning Comparative Examples 1-4 was shown in Table 1.

[Comparative Example 5]
The heat ray shielding laminated transparency according to Comparative Example 5 was the same as Example 12 except that the concentration of the fine particles b in the composition of the fine particles b, the acrylic dispersant, and the plasticizer was changed and no ultraviolet absorber was added. A substrate was obtained.
Table 1 shows the concentration of the fine particles b in the composition according to Comparative Example 5.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning the comparative example 5 was shown in Table 1.

[Comparative Examples 6-7]
Comparative Examples 6-7 in the same manner as in Example 1 except that the concentration of the fine particles a and the concentration of the absorbent A in the composition of the fine particles a, the acrylic dispersant, the absorbent A, and the plasticizer were changed. The heat ray shielding laminated transparent base material which concerns on was obtained.
Table 1 shows the concentration of the fine particles a and the concentration of the absorbent A in the compositions according to Comparative Examples 6 to 7.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning Comparative Examples 6-7 was shown in Table 1.

[Comparative Example 8]
Inorganic ultraviolet absorber Same as Example 1 except that fine particles of cerium oxide (hereinafter abbreviated as “absorbent D”) were used and the concentration of fine particles a and the concentration of absorbent D in the composition were changed. Thus, a heat ray shielding laminated transparent base material according to Comparative Example 8 was obtained.
When the dispersion of the absorbent D was diluted with MIBK to a predetermined concentration and placed in a glass cell, the optical characteristics were measured. The transmittance of light at a wavelength of 400 nm was 21.0%, and the transmittance of light at a wavelength of 500 nm Was 89.2%.
Table 1 shows the concentration of the fine particles a and the concentration of the absorbent D in the composition according to Comparative Example 8.
And the optical characteristic test result of the heat ray shielding laminated transparent base material concerning the comparative example 8 was shown in Table 1.

[Evaluation of Examples 1 to 17 and Comparative Examples 1 to 5]
In Examples 1 to 17, an ultraviolet absorber having a transmittance profile in which the transmittance of light with a wavelength of 500 nm is 95% or more and the transmittance of light with a wavelength of 400 nm is 2% or less is combined with tungsten oxide. Used together with fine particles. By the combined use, compared with Comparative Examples 1 to 5 in which the composite tungsten oxide fine particles were used alone, a peak value of diffuse transmittance was low, and a highly transparent heat ray shielding laminated transparent base material was obtained.

The heat ray shielding laminated transparent base materials according to Examples 1 to 17 and Comparative Examples 1 to 5 are irradiated with strong pseudo-sunlight (Cerrick Co., Ltd. lamp XC-100), and the occurrence state of blue haze is visually observed. Confirmed.
Then, in Examples 1-17, compared with Comparative Examples 1-5 which used the composite tungsten oxide fine particle independently, it has confirmed that it was suppressed obviously.

  In addition, the combined use of the ultraviolet absorber with the composite tungsten oxide fine particles allowed the change in visible light transmittance after 200 hours of the xenon weatherometer test to be compared with Comparative Examples 1 to 5 using the composite tungsten oxide fine particles alone. As a result, the long-term durability is improved.

[Evaluation of Comparative Example 6]
Since the addition amount of the ultraviolet absorber is outside the range of (composite tungsten oxide fine particles / ultraviolet absorber) = 70/30 to 1/99, the ultraviolet ray absorption wavelength of the obtained heat ray shielding film is on the relatively short wavelength side. I stayed. As a result, although the peak value of the diffuse transmittance could be suppressed to some extent, the effect of suppression was small as compared with Examples 1-14.

[Evaluation of Comparative Example 7]
Since the addition amount of the ultraviolet absorber is outside the range of (composite tungsten oxide fine particles / ultraviolet absorber) = 70/30 to 1/99, the ultraviolet absorber is precipitated from the surface of the obtained heat ray shielding film, and the heat ray shielding. The laminated transparent base material has become cloudy. Moreover, the adhesiveness of a heat ray shielding film and a transparent base material was bad, and the malfunction which peels easily occurred.

[Evaluation of Comparative Example 8]
In the transmittance profile of the absorbent D used, the transmittance of light with a wavelength of 500 nm is 95% or less, and the transmittance of light with a wavelength of 400 nm is 2% or more. For this reason, absorption in the vicinity of a wavelength of 400 nm cannot be sufficiently obtained, the peak value of diffuse transmittance is increased, and the effect of suppressing blue haze is not sufficiently obtained. Further, as a result of the decrease in visible light transmittance, the heat ray shielding characteristics are reduced as compared with the case where the composite tungsten oxide fine particles are used alone.

DESCRIPTION OF SYMBOLS 1 Light source 2 Heat ray shielding matching transparent base material 3 Light receiver 4 Integrating sphere 5 Standard reflector 6 Optical trap

Claims (5)

A heat ray shielding film that is a kneaded product of fine particles having a heat ray shielding function, a UV absorber, a resin mainly composed of polyvinyl acetal resin, and a plasticizer , and a molded product of the kneaded product ,
The fine particles having a heat ray shielding function are selected from the general formula M _y WO _Z (where M is selected from Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, Sn, Al, Cu). One or more elements, 0.1 ≦ y ≦ 0.5, 2.2 ≦ z ≦ 3.0), and a composite tungsten oxide fine particle having a hexagonal crystal structure,
The ultraviolet absorbent has a light transmittance of 95% or more at a wavelength of 500 nm and a light transmittance of 2% or less at a wavelength of 400 nm,
A heat ray shielding film, wherein a weight ratio of the composite tungsten oxide fine particles to the ultraviolet absorber is in the range of (composite tungsten oxide fine particles / ultraviolet absorber) = 70/30 to 1/99.   2. The heat ray shielding film according to claim 1, wherein the ultraviolet absorber is at least one selected from a benzotriazole ultraviolet absorber, a benzophenone ultraviolet absorber, and a triazine ultraviolet absorber.   The heat ray shielding film according to claim 1, wherein the composite tungsten oxide fine particles are fine particles having an average particle diameter of 40 nm or less.   The heat ray shielding laminated transparent base material in which the heat ray shielding film in any one of Claims 1-3 exists between at least 2 or more transparent base materials.   The heat ray shielding laminated transparent base material according to claim 4, wherein at least one of the transparent base materials is glass.

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