WO2019054477A1 - Cover-soil film for agricultural gardening and method for producing same - Google Patents

Abstract

Provided is a covering film for agricultural gardening, the covering film reflecting visible light from sunlight, etc., more efficiently than in the past, supplying light that is necessary to plant growth to plants, absorbing infrared light, heating soil, and not raising the air temperature of the atmosphere within a greenhouse, etc. The present invention provides a covering film for agricultural gardening, the covering film being characterized by having a white-light-reflecting layer that contains a white-light-reflective material, and an infrared-light-absorbing layer that contains infrared-light-absorptive-material microparticles, and moreover being characterized in that: the infrared-light-absorptive-material microparticles are composite tungsten oxide microparticles; when the contained crystals have a hexagonal crystal system, the a-axis and c-axis values of the lattice constant thereof are such that the a-axis is 7.3850-7.4186 Å and the c-axis is 7.5600-7.6240 Å; and the average particle diameter of the microparticles is 100 nm or less.

Description

Soil coating film for agriculture and horticulture and method for producing the same

The present invention has a white light reflecting layer containing a white light reflecting material, and an infrared light absorbing layer formed by coating with infrared light absorbing material fine particles absorbing infrared light from sunlight or the like, By reflecting light and absorbing infrared light, visible light required for plant growth is reflected to the plant side, infrared light as heat is absorbed to warm the soil, and the temperature of the atmosphere in a greenhouse etc. TECHNICAL FIELD The present invention relates to an agricultural and horticultural soil covering film not to be raised and a method for producing the same.

As a method of promoting the growth of plants, a reflection sheet using a metal film such as aluminum, a sheet reflecting white light using a film of a white light reflection material, a sheet further coated with a reflection material on the reflection sheet, etc. It is known to use the method to coat the soil surface. However, since these sheets reflect sunlight rays reaching the ground surface evenly, plant growth is promoted, but infrared light which is heat is also reflected. As a result, there is a disadvantage that the temperature of the atmosphere in the greenhouse etc. rises. Furthermore, a reflective sheet using a metal film such as aluminum is generally subjected to a metal vapor deposition process such as aluminum, which causes problems such as cost increase.

On the other hand, synthetic resin sheets such as polyethylene and polyvinyl chloride are generally known as sheets for keeping the soil warm. However, since these synthetic resin sheets generally have a high infrared transmittance, the heat retention effect of the soil is not sufficient. In order to solve this problem, Patent Document 1 proposes a heat retaining sheet for covering the ground, in which a band-shaped film having infrared reflectivity and a band-shaped film having infrared absorptivity are knitted or woven as warps or wefts, respectively. ing.

In Patent Document 2, a black or blue pigment such as carbon black is dispersed in a binder on the surface of a whitening film having a total light transmittance of 3.0% or more and a diffuse reflectance of 40% or more. Printed films for crop cultivation have been proposed.

In Patent Document 3, the applicant selects tungsten oxide fine particles and composite tungsten oxide fine particles as a material that absorbs infrared light although the visible light reflectance is high, and these fine particles are used as near-infrared absorbing components. An agricultural and horticultural soil covering film was disclosed.

JP-A-9-107815 Japanese Patent Application Laid-Open No. 55-127946 WO 2006/100799

However, according to the study of the present inventors, the heat retaining sheet according to Patent Document 1 has a problem that the manufacturing cost is high because the belt-like film having infrared reflectivity has been subjected to aluminum deposition processing.
Moreover, the film for crop cultivation which concerns on patent document 2 is 1.0 to 60% of the area of a colored film layer, Moreover, since it is not a structure which absorbs the infrared rays used as heat efficiently, it is the effect of heating soil. Was not enough.
Here, by using the soil covering film for agriculture and horticulture according to Patent Document 3, visible light necessary for growing a spot is supplied to the plant side, infrared light is absorbed, the soil is warmed, and used in a greenhouse etc. If it was, it became possible not to raise the temperature of the atmosphere in the greenhouse etc. However, according to further studies by the present inventors, the near-infrared absorption characteristics of the agricultural and horticultural soil covering film containing tungsten oxide microparticles or composite tungsten oxide microparticles produced by the method proposed in Patent Document 3 are sufficiently satisfactory. It turned out not to be a thing.

The present invention has been made to solve these problems, and absorbs infrared light from sunlight more efficiently than in the past to warm the soil, while the above-mentioned agricultural and horticultural coated film When it uses in a greenhouse etc., it aims at providing the soil covering film for agriculture and horticulture which does not raise the temperature of atmosphere of the said greenhouse etc.

The present inventors conducted intensive studies to achieve the above object. Then, in the composite tungsten oxide fine particles, in the composite tungsten oxide fine particles which are near infrared absorbing material fine particles, the crystal contained is made hexagonal, the values of the a axis and the c axis in the lattice constant thereof are 7. The present invention has been completed in consideration of a configuration in which the crystallinity is enhanced with 3850 Å or more and 7.4186 Å or less, c axis is 7.5600 Å or more and 7.6240 Å or less, and the average particle diameter of the fine particles is 100 nm or less.

The infrared absorbing film containing the composite tungsten oxide fine particles according to the present invention as a near infrared absorbing component is compared with the infrared absorbing film disclosed in Patent Document 3 and it is possible to use the solar interference effect without using the light interference effect. It has been found that light rays, particularly light in the near infrared region, can be absorbed more efficiently and, at the same time, light in the visible light region is transmitted, thereby completing the present invention.

That is, the first invention for solving the above-mentioned problems is:
An agricultural and horticultural soil covering film having an infrared light absorbing layer containing infrared light absorbing material fine particles,
The infrared absorbing material fine particles are composite tungsten oxide fine particles including a hexagonal crystal structure,
The lattice constant of the composite tungsten oxide fine particles is 7.3850 Å or more and 7.4186 Å or less for the a axis and 7.5600 Å or more and 7.6240 Å or less for the c axis.
The average particle diameter of the said composite tungsten oxide microparticles | fine-particles is 100 nm or less, It is a covering film for agriculture and horticulture characterized by the above-mentioned.
The second invention is
The agronomic horticulture according to the first invention is characterized in that the lattice constant of the composite tungsten oxide fine particles is a-axis 7.4033 Å to 7.4111 Å, and c-axis 7.5891 Å to 7.6240 Å. It is a covered soil film.
The third invention is
The average particle diameter of the said composite tungsten oxide microparticles | fine-particles is 10 nm or more and 100 nm or less, It is a covering film for agriculture and horticulture as described in the 1st or 2nd invention characterized by the above-mentioned.
The fourth invention is
The composite tungsten oxide fine particles are dispersed and present in the resin binder of the infrared light absorbing layer provided on at least one surface of the agricultural and horticultural soil covering film. An agricultural and horticultural soil covering film according to any of the inventions described above.
The fifth invention is
The coated tungsten oxide film according to any one of the first to fourth inventions, wherein the composite tungsten oxide fine particles are dispersed and present in the film of the coated soil film for agricultural and horticultural purposes.
The sixth invention is
The coated film for agriculture and horticulture according to any one of the first to fifth inventions, wherein a crystallite diameter of the composite tungsten oxide fine particles is 10 nm or more and 100 nm or less.
The seventh invention is
The composite tungsten oxide fine particles have a 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, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb, W being tungsten, O being oxygen, 0.001 ≦ x / y In the agricultural and horticultural coated film according to any one of the first to sixth inventions, the composite tungsten oxide fine particles are represented by ≦ 1 and 2.0 ≦ z / y ≦ 3.0). is there.
The eighth invention is
The agricultural and horticultural coated film according to the seventh invention, wherein the M element is at least one element selected from Cs and Rb.
The ninth invention is
At least a part of the surface of the composite tungsten oxide fine particles is covered with a surface covering film containing at least one or more elements selected from Si, Ti, Zr, and Al. It is an agricultural and horticultural soil covering film in any one of the 1st invention.
The tenth invention is
The agricultural and horticultural soil covering film according to the ninth invention, wherein the surface coating film contains an oxygen atom.
The eleventh invention is
The film is made of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, tetrachlorotrifluoroethylene, polyvinyl chloride, poly The agricultural and horticultural coated film according to any of the first to tenth inventions, which is at least one selected from vinylidene chloride, polyvinyl alcohol, polystyrene, ethylene vinyl acetate, and polyester resin.
The twelfth invention is
The agricultural and horticultural coating film according to any one of the first to eleventh inventions, wherein a white light reflecting layer in which a white light reflecting material is dispersed is provided inside a film for the agricultural and horticultural covering film. .
The thirteenth invention is
A white light reflecting layer coated with a white light reflecting material on one side of the agricultural and horticultural soil covering film, and an infrared light absorbing layer further coated with infrared light absorbing material fine particles on the white light reflecting layer Have,
Alternatively, a white light reflecting layer coated with a white light reflecting material on one side of the agricultural and horticultural coated film, and an infrared ray coated with infrared light absorbing material particles on the other side of the agricultural and horticultural coated film. Having a light absorbing layer,
It is an agricultural and horticultural soil covering film in any one of the 1st-12th invention characterized by the above-mentioned.
The fourteenth invention is
The white light reflecting material is at least one selected from TiO ₂ , ZrO ₂ , SiO ₂ , Al ₂ O ₃ , MgO, ZnO, CaCO ₃ , BaSO ₄ , ZnS, and PbCO _3. It is an agricultural and horticultural soil covering film as described in the 12th or 13th invention.
The fifteenth invention is
A method for producing an agricultural and horticultural soil covering film having an infrared light absorbing layer containing infrared light absorbing material fine particles,
The infrared absorbing material fine particles are composite tungsten oxide fine particles including a hexagonal crystal structure,
The composite tungsten oxide fine particles are manufactured so that the lattice constant is in the range of 7.3850 Å to 7.4186 Å in the a axis and 7.5600 Å to 7.6240 Å in the c axis.
It is a manufacturing method of the covering film for agriculture and horticulture characterized by performing a grinding / dispersing treatment process which makes an average particle diameter 100 nm or less, maintaining the range of the lattice constant in the composite tungsten oxide fine particles.
The sixteenth invention is
The composite tungsten oxide fine particles have a 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, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb, W being tungsten, O being oxygen, 0.001 ≦ x / y It is a composite tungsten oxide fine particle represented by <= 1 and 2.0 <= z / y <= 3.0), It is a manufacturing method of the covering film for agriculture and horticulture described in the 15th invention characterized by the above-mentioned.
The seventeenth invention is
The method for producing an agricultural and horticultural coated film according to the sixteenth invention is characterized in that the M element is one or more kinds of elements selected from Cs and Rb.
The eighteenth invention is
At least a part of the surface of the composite tungsten oxide fine particles is covered with a surface covering film containing at least one or more elements selected from Si, Ti, Zr, and Al. It is a manufacturing method of the covering film for agriculture and horticulture in any one of 17 invention.
The nineteenth invention is
The method of producing an agricultural and horticultural soil covering film according to the eighteenth invention, wherein the surface coating film contains an oxygen atom.
The twentieth invention is
The film for the agricultural and horticultural coating film is polyethylene, polypropylene, polyethylene terephthalate, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, tetrachlorotrifluoroethylene In any of the fifteenth to nineteenth inventions, it is a film comprising one or more resins selected from polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polystyrene, ethylene vinyl acetate, and polyester resins. It is a manufacturing method of the covering film for agriculture and horticulture of a statement.

The agricultural and horticultural soil covering film according to the present invention efficiently absorbs infrared rays from sunlight, so by covering the ground where plants etc. are grown with the agricultural and horticultural soil covering film, the temperature of the covered ground is It rises and the soil warms up. On the other hand, when the soil covering film for agriculture and horticulture is used in a greenhouse etc., it is effective not to raise the temperature of the atmosphere in the greenhouse etc.

It is a conceptual diagram of a high frequency plasma reactor used for the present invention.

An agricultural and horticultural soil covering film according to the present invention is an agricultural and horticultural soil covering film containing composite tungsten oxide microparticles having a predetermined configuration as infrared light absorbing material microparticles. Then, about the form for carrying out the earth covering film for agriculture and horticulture which concerns on this invention, [a] composite tungsten oxide microparticles, [b] the synthesis method of composite tungsten oxide microparticles, [c] composite tungsten oxide microparticles dispersion liquid, [D] Soil covering film for agriculture and horticulture, will be described in the order.

[A] Composite tungsten oxide fine particles The agricultural soil coating film according to the present invention is a film having the characteristic that the absorptivity of light in the infrared region is high, including composite tungsten oxide fine particles as infrared light absorbing material fine particles. . Therefore, first, composite tungsten oxide fine particles, which are infrared light absorbing material fine particles, will be described.
The composite tungsten oxide fine particle according to the present invention is a composite tungsten oxide fine particle having near infrared absorption characteristics and including a hexagonal crystal structure, and the lattice constant of the hexagonal composite tungsten oxide has an a axis 7.3850 Å or more and 7.4186 Å or less, and c axis is 7.5600 Å or more and 7.6240 Å or less. And it is preferable that the value of the ratio which concerns on (lattice constant of c axis / lattice constant of a axis | shaft) is 1.0221 or more and 1.0289 or less. In addition, the composite tungsten oxide fine particles according to the present invention have an average particle diameter of 100 nm or less.
Hereinafter, with respect to the composite tungsten oxide fine particles according to the present invention, (1) crystal structure and lattice constant, (2) particle diameter and crystallite diameter, (3) composition of composite tungsten oxide fine particles, (4) composite tungsten oxide The surface coating of fine particles, (5) summary, will be described in the order.

(1) Crystal structure and lattice constant The composite tungsten oxide fine particles according to the present invention have a tetragonal or cubic tungsten bronze structure in addition to a hexagonal crystal, but any structure may be used as a near-infrared absorbing material It is valid. However, the absorption position in the near infrared region tends to change depending on the crystal structure of the composite tungsten oxide fine particles. That is, the absorption position in the near infrared region tends to move to a longer wavelength side when tetragonal than cubic, and move further to a longer wavelength than tetragonal when it is hexagonal. Moreover, incidentally to the fluctuation of the absorption position, absorption of light in the visible light region is the least hexagonal and secondly tetragonal, and the cubic is the largest among them.

From the above findings, it is most preferable to use hexagonal tungsten bronze for applications in which light in the visible light region is more transmitted and light in the near infrared region is more absorbed. When the composite tungsten oxide particles have a hexagonal crystal structure, the transmittance of the particles in the visible light region is improved, and the absorption in the near infrared region is improved. In this hexagonal crystal structure, _six octahedra formed of WO ₆ units are assembled to form a hexagonal void (tunnel), and the M element is disposed in the void to form one unit. , And a large number of units of one unit are assembled to form a hexagonal crystal structure.

In order to improve the transmission in the visible light region and to improve the absorption in the near infrared region according to the present invention, a unit structure (an octahedron formed of WO ₆ units) in the composite tungsten oxide fine particles It is only necessary that six of them are assembled to form a hexagonal void, and the void has a structure in which the M element is disposed.
When a cation of M element is added to and present in this hexagonal void, the absorption in the near infrared region is improved. Here, generally, when the M element having a large ion radius is added, the hexagonal crystal is formed, and specifically, one or more selected from Cs, Rb, K, Tl, In, and Ba are added. When this is done, hexagonal crystals are easily formed, which is preferable.
Furthermore, in the composite tungsten oxide fine particles to which one or more types selected from Cs and Rb are added among the large M elements of the ion radius, compatibility between absorption in the near infrared region and transmission in the visible light region can be achieved. .
When two or more kinds of M elements are selected, one of them is selected from Cs, Rb, K, Tl, Ba, and In, and the rest is selected from one or more elements constituting the M element. Also, it may be hexagonal.

In the case of Cs tungsten oxide fine particles in which Cs is selected as the M element, the lattice constant thereof is preferably 7.4031 Å or more and 7.4186 Å or less for the a axis and 7.5750 Å or more and 7.6240 Å or less for the c axis, Preferably, the a-axis is 7.4031 Å or more and 7.4111 Å or less, and the c-axis is 7.5891 Å or more and 7.6240 Å or less.
In the case of Rb tungsten oxide fine particles in which Rb is selected as the M element, the lattice constant thereof is preferably 7.3850 Å to 7.3950 Å for the a axis and 7.5600 Å to 7.5700 Å for the c axis.
In the case of CsRb tungsten oxide fine particles in which Cs and Rb are selected as the M element, the lattice constant is that the a axis is 7.3850 Å or more and 7.4186 Å or less and the c axis is 7.5600 Å or more and 7.6240 Å or less preferable.
However, the M element is not limited to the above Cs and Rb. Even if the M element is an element other than Cs and Rb, it may be present as an added M element in a hexagonal gap formed of a WO ₆ unit.

When the composite tungsten oxide fine particles having a hexagonal crystal structure according to the present invention are represented by the general formula MxWyOz, when the composite tungsten oxide fine particles have a uniform crystal structure, the additive M element is added in an amount of 0. 001 ≦ x / y ≦ 1, preferably 0.2 ≦ x / y ≦ 0.5, more preferably 0.20 ≦ x / y ≦ 0.37, and most preferably x / y = 0.33. This is because, theoretically, when z / y = 3, x / y = 0.33, and it is considered that the added M element is disposed in all of the hexagonal voids. Typical examples include Cs _0.33 WO ₃ , Cs _0.03 Rb _0.30 WO ₃ , Rb _0.33 WO ₃ , K _0.33 WO ₃ , Ba _0.33 WO _{3 and the} like. .

Here, the present inventors repeatedly conducted researches on measures to further improve the near infrared absorption function of the composite tungsten oxide fine particles, and conceived a configuration to further increase the amount of free electrons contained.
That is, as a measure for increasing the amount of free electrons, mechanical processing is applied to the composite tungsten oxide fine particles to give appropriate distortion and deformation to the contained hexagonal crystals. In the hexagonal crystal to which the appropriate strain or deformation is given, the overlapping state of the electron orbits in the atoms constituting the crystallite structure is considered to change and the amount of free electrons increases.

Based on the above-mentioned idea, the present inventors manufacture a composite tungsten oxide fine particle dispersion liquid from particles of the composite tungsten oxide formed in the firing step of "a synthesis method of composite tungsten oxide fine particles" described later. In the dispersion process, the particles of the composite tungsten oxide are crushed under predetermined conditions to impart strain or deformation to the crystal structure to increase the amount of free electrons, and the near infrared absorption function of the composite tungsten oxide fine particles To further improve the

And from the said research, the particle | grains of complex tungsten oxide produced | generated through the baking process were examined paying attention to each particle | grain. Then, it was found that the respective lattice constants and constituent element compositions also had variations among the respective particles.
As a result of further research, in the composite tungsten oxide fine particles finally obtained regardless of variations in lattice constant and constituent element composition among the respective particles, it is desirable if the lattice constant is within a predetermined range. We have found that they exhibit optical properties.

The inventors of the present invention who have obtained the above-described findings further measure distortion and deformation of the crystal structure of the fine particle by measuring the a-axis and c-axis which are lattice constants in the crystal structure of the complex tungsten oxide fine particle. The optical properties of the particles were studied while grasping the degree.
As a result of the research, when the a-axis is 7.3850 Å or more and 7.4186 Å or less and the c-axis is 7.5600 Å or more and 7.6240 Å or less in the hexagonal composite tungsten oxide particles, the particles have a wavelength of 350 nm We have found that it is a near-infrared-absorbing fine particle that exhibits a light transmissivity that has a maximum value in the range of 600 nm and a minimum value in the range of wavelengths 800 nm to 2100 nm and exhibits an excellent near-infrared absorption effect. .

Furthermore, in the hexagonal composite tungsten oxide particles having an a-axis of 7.3850 Å or more and 7.4186 Å or less and a c-axis of 7.5600 Å or more and 7.6240 Å or less according to the present invention, the M element When the value of x / y indicating the addition amount is in the range of 0.001 ≦ x / y ≦ 1, preferably in the range of 0.20 ≦ x / y ≦ 0.37, particularly excellent near We also found that it exhibits an infrared absorption effect.

It has also been found that the composite tungsten oxide fine particles as the near infrared light absorbing material fine particles are preferably single crystals in which the volume ratio of the amorphous phase is 50% or less.
If the composite tungsten oxide fine particles are a single crystal having a volume ratio of 50% or less of the amorphous phase, the crystallite diameter can be 10 nm or more and 100 nm or less while maintaining the lattice constant within the above-described predetermined range, It is considered that excellent optical properties can be exhibited.

The fact that the composite tungsten oxide fine particles are a single crystal is confirmed because no grain boundaries are observed inside each fine particle in an electron microscope image by a transmission electron microscope etc., and only a uniform checkered pattern is observed. can do. In the composite tungsten oxide fine particles, the volume ratio of the amorphous phase is 50% or less, similarly to the transmission electron microscope image, a uniform checkered pattern is observed throughout the fine particles, and a portion where the checkered pattern is unclear is almost observed It can be confirmed from not being done.
Furthermore, since the amorphous phase is often present at the outer peripheral portion of each particle, the volume ratio of the amorphous phase can often be calculated by focusing on the outer peripheral portion of each particle. For example, in a true spherical composite tungsten oxide fine particle, when an amorphous phase with unclear lattice stripes is present in the form of a layer in the outer peripheral portion of the fine particle, the composite tungsten oxide is oxidized if the thickness is 10% or less of the average particle diameter. The volume ratio of the amorphous phase in the fine particles is 50% or less.

On the other hand, when the composite tungsten oxide fine particles are dispersed in a matrix of a solid medium such as a resin constituting the composite tungsten oxide fine particle dispersion, crystals are obtained from the average particle diameter of the dispersed composite tungsten oxide fine particles If the value obtained by subtracting the particle size is 20% or less of the average particle size, it can be said that the composite tungsten oxide fine particles are single crystals having a volume ratio of 50% or less of the amorphous phase.

From the above, the value obtained by subtracting the crystallite diameter from the average particle size of the composite tungsten oxide fine particles dispersed in the composite tungsten oxide fine particle dispersion is 20% or less of the value of the average particle size. It is preferable to appropriately adjust the synthesis step, the grinding step, and the dispersion step of the composite tungsten oxide fine particles according to the manufacturing equipment.
In addition, the measurement of the crystal structure and lattice constant of the composite tungsten oxide fine particles is included in the fine particles of the composite tungsten oxide fine particles obtained by removing the solvent of the near infrared absorber forming dispersion by X-ray diffraction method. The a-axis length and c-axis length can be calculated as lattice constants by specifying the crystal structure to be used and using the Rietveld method.

(2) Particle Size and Crystallite Size The composite tungsten oxide fine particles according to the present invention have an average particle size of 100 nm or less. And from the viewpoint of exhibiting more excellent infrared absorption characteristics, the average particle diameter is preferably 10 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less, and still more preferably 10 nm or more and 60 nm or less. If the average particle size is in the range of 10 nm to 60 nm, the most excellent infrared absorption characteristics are exhibited.
Here, the average particle size is the value of the diameter of each composite tungsten oxide fine particle which is not aggregated, and is the particle size of the composite tungsten oxide fine particle contained in the composite tungsten oxide fine particle dispersion described later.
On the other hand, the average particle diameter does not include the diameter of the aggregate of the composite tungsten oxide fine particles, and is different from the dispersed particle diameter.

The average particle size is calculated from an electron microscopic image of the near-infrared absorbing material fine particles.
The average particle diameter of the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion is the composite tungsten oxide fine particles from the transmission electron microscope image of the exfoliated sample of the composite tungsten oxide fine particle dispersion taken out by cross-sectional processing The particle diameter of 100 particles can be measured by using an image processing apparatus, and the average value can be calculated. A microtome, a cross section polisher, a focused ion beam (FIB) apparatus or the like can be used for cross-sectional processing for taking out the exfoliated sample. The average particle size of the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion is the average value of the particle sizes of the composite tungsten oxide fine particles dispersed in the solid medium which is the matrix.

Further, from the viewpoint of exhibiting excellent infrared absorption characteristics, the crystallite diameter of the composite tungsten oxide fine particles is preferably 10 nm to 100 nm, more preferably 10 nm to 80 nm, and still more preferably 10 nm to 60 nm. . If the crystallite diameter is in the range of 10 nm to 60 nm, the most excellent infrared absorption characteristics are exhibited.

Incidentally, the lattice constant and the crystallite diameter of the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion obtained after passing through the crushing treatment, the pulverizing treatment or the dispersion treatment described later are the dispersion of the composite tungsten oxide fine particles. The composite tungsten oxide fine particles obtained by removing volatile components from the liquid and the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion obtained from the composite tungsten oxide fine particle dispersion are also maintained. .
As a result, the effects of the present invention are exhibited even in the composite tungsten oxide fine particle dispersion according to the present invention and the composite tungsten oxide fine particle dispersion containing the composite tungsten oxide fine particles.

(3) Composition of Composite Tungsten Oxide Fine Particles The composite tungsten oxide fine particles according to the present invention have a 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, Zn, Cd, Al, Ga, In, T1, Si, Ge, Sn, Pb, Sb, B, F , P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb, one or more elements, W is tungsten, O is preferably a composite tungsten oxide fine particle represented by oxygen, 0.001 ≦ x / y ≦ 1, 2.0 ≦ z / y ≦ 3.0).

The composite tungsten oxide fine particles represented by the general formula MxWyOz will be described.
The element M, x, y, z and the crystal structure thereof in the general formula MxWyOz are closely related to the free electron density of the composite tungsten oxide fine particles, and greatly influence the near infrared absorption characteristics.

Generally, tungsten trioxide (WO ₃ ) has low near infrared absorption characteristics because no effective free electrons exist.
Here, the present inventors indicate that the tungsten oxide can be converted into the M element (wherein the M element is H, He, an alkali metal, an alkaline earth metal, a rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, T1, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, At least one element selected from Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb) to form a composite tungsten oxide And free electrons are generated in the composite tungsten oxide, and absorption characteristics derived from free electrons appear in the near infrared region to be effective as a near infrared light absorbing material near a wavelength of 1000 nm, and the composite tungsten Oxide is chemically cheap Maintaining the state, it is obtained by finding that becomes effective as near-infrared-absorbing material which is excellent in weather resistance. Furthermore, the M element is preferably Cs, Rb, K, Tl, Ba, or In. Among them, when the M element is Cs or Rb, the composite tungsten oxide can easily have a hexagonal crystal structure. As a result, since visible light is transmitted and near infrared rays are absorbed and absorbed, it has also been found that it is particularly preferable for the reason described later. When two or more kinds of M elements are selected, one of them is selected from Cs, Rb, K, Tl, Ba, and In, and the rest is selected from one or more elements constituting the M element. Also, it may be hexagonal.

Here, the present inventors' knowledge about the value of x which shows the addition amount of M element is demonstrated.
When the value of x / y is 0.001 or more, a sufficient amount of free electrons can be generated to obtain the desired near infrared absorption characteristics. The amount of free electrons supplied increases as the amount of M element added increases, and the near infrared absorption characteristics also increase, but the effect is also saturated when the value of x / y is about 1. Moreover, if the value of x / y is 1 or less, generation of an impurity phase in the composite tungsten fine particles can be avoided, which is preferable.

Next, the present inventors' knowledge about the value of z which shows control of oxygen amount is demonstrated.
In the composite tungsten oxide fine particles represented by the general formula MxWyOz, the value of z / y is preferably 2.0 ≦ z / y ≦ 3.0, more preferably 2.2 ≦ z / y ≦ 3. It is 0, more preferably 2.6 ≦ z / y ≦ 3.0, and most preferably 2.7 ≦ z / y ≦ 3.0. If the value of z / y is 2.0 or more, it is possible to avoid the appearance of the crystal phase of WO ₂ other than the purpose in the composite tungsten oxide, and it is possible to obtain chemical stability as a material. It is because it can be applied as an effective infrared absorbing material because it can obtain the properties. On the other hand, if the value of z / y is 3.0 or less, the required amount of free electrons is generated in the tungsten oxide, and the material becomes an efficient infrared absorbing material.

(4) Surface Coating Film of Composite Tungsten Oxide Fine Particles At least a part of the surface of the composite tungsten oxide fine particles is selected from silicon, zirconium, titanium and aluminum in order to improve the weather resistance of the composite tungsten oxide fine particles It is also preferable to coat with a surface coating film containing one or more elements. These surface coating films are basically transparent, and their addition does not lower the visible light transmittance of the composite tungsten oxide fine particles. Although the coating method is not particularly limited, it is possible to coat the surface of the composite tungsten oxide particles by adding an alkoxide of a metal containing the above element to a solution in which the composite tungsten oxide particles are dispersed. In this case, the surface coating film contains oxygen atoms, but it is more preferable that the surface coating film is made of an oxide.

(5) Summary As described above, the lattice constant, the average particle diameter, and the crystallite diameter of the composite tungsten oxide fine particles described above can be controlled by predetermined manufacturing conditions. Specifically, in the thermal plasma method and solid phase reaction method described later, the temperature (sintering temperature) at which the fine particles are formed, the formation time (sintering time), the formation atmosphere (sintering atmosphere) Control can be performed by appropriate setting of manufacturing conditions such as form, annealing after formation, doping with an impurity element, and the like.

[B] Synthesis Method of Composite Tungsten Oxide Fine Particles The method of synthesizing the composite tungsten oxide fine particles according to the present invention will be described.
As a synthesis method of the composite tungsten oxide fine particles according to the present invention, there are a thermal plasma method in which a starting material of a tungsten compound is introduced into thermal plasma, and a solid phase reaction method in which a tungsten compound starting material is heat-treated in a reducing gas atmosphere It can be mentioned. The composite tungsten oxide fine particles synthesized by the thermal plasma method or the solid phase reaction method are subjected to dispersion treatment or grinding / dispersion treatment.
Hereinafter, (1) thermal plasma method, (2) solid phase reaction method, and (3) synthesized composite tungsten oxide fine particles will be described in order.

(1) Thermal Plasma Method The thermal plasma method will be described in the order of (i) raw materials used for the thermal plasma method, (ii) thermal plasma method and conditions thereof.

(I) Raw Material Used for Thermal Plasma Method When the composite tungsten oxide fine particles according to the present invention are synthesized by the thermal plasma method, a mixed powder of a tungsten compound and an M element compound can be used as a raw material.
As a tungsten compound, tungstic acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride, hydrate of tungsten obtained by hydrolysis after adding water to tungsten hexachloride dissolved in alcohol and then evaporating the solvent, It is preferable that it is 1 or more types chosen from.

Moreover, as the M element compound, it is preferable to use one or more selected from oxides, hydroxides, nitrates, sulfates, chlorides, and carbonates of M elements.
In the aqueous solution containing the above-described tungsten compound and the above-described M element compound, the ratio of the M element to the W element is MxWyOz (where M is the M element, W is tungsten, O is oxygen, 0.001 ≦ x / It wet mixes so that it may become a ratio of M element and W element of y <= 1.0 and 2.0 <= z / y <= 3.0). And by drying the obtained liquid mixture, the mixed powder of M element compound and a tungsten compound is obtained, and the said mixed powder can be made into the raw material of a thermal plasma method.

In addition, the composite tungsten oxide obtained by the first-step firing is used as a raw material of the thermal plasma method in the mixed gas atmosphere of an inert gas alone or a mixed gas of an inert gas and a reducing gas. It can also be done. In addition, in the first step, firing is performed in a mixed gas atmosphere of an inert gas and a reducing gas, and in the second step, the fired product in the first step is fired under an inert gas atmosphere. The composite tungsten oxide obtained by the step firing can also be used as a raw material of the thermal plasma method.

(Ii) Thermal plasma method and conditions thereof As thermal plasma used in the present invention, any of direct current arc plasma, high frequency plasma, microwave plasma, low frequency alternating current plasma, or a superposition of these plasmas, or A plasma generated by an electrical method in which a magnetic field is applied to a direct current plasma, a plasma generated by irradiation of a high power laser, a plasma generated by a high power electron beam or an ion beam can be applied. However, whichever thermal plasma is used, it is preferably a thermal plasma having a high temperature portion of 10000 to 15000 K, and in particular, a plasma capable of controlling the generation time of the fine particles.

The raw material supplied into the thermal plasma having the high temperature part evaporates instantaneously in the high temperature part. Then, the evaporated raw material is condensed in the process of reaching the plasma tail flame portion, and is rapidly solidified outside the plasma flame to generate composite tungsten oxide fine particles.

The synthesis method will be described with reference to FIG. 1 by taking a high frequency plasma reaction apparatus as an example.
First, the inside of a reaction system constituted by a water-cooled quartz double pipe and the inside of the reaction vessel 6 is evacuated to about 0.1 Pa (about 0.001 Torr) by an evacuation apparatus. After evacuating the inside of the reaction system, next, the inside of the reaction system is filled with argon gas to form an argon gas flow system at 1 atm.
After that, any gas selected from argon gas, mixed gas of argon and helium (Ar-He mixed gas), or mixed gas of argon and nitrogen (Ar-N ₂ mixed gas) as plasma gas in the reaction vessel Is introduced from the plasma gas supply nozzle 4 at a flow rate of 30 to 45 L / min. On the other hand, an Ar—He mixed gas is introduced from the sheath gas supply nozzle 3 at a flow rate of 60 to 70 L / min as a sheath gas flowing immediately outside the plasma region.
Then, an alternating current is applied to the high frequency coil 2 to generate a thermal plasma 1 by a high frequency electromagnetic field (frequency 4 MHz). At this time, the high frequency power is set to 30 to 40 kW.

Furthermore, the mixed powder of the M element compound and the tungsten compound obtained by the above synthesis method from the powder supply nozzle 5 or the composite tungsten oxide is supplied from the gas supply device with an argon gas of 6 to 98 L / min as a carrier. The gas is introduced into the thermal plasma at a supply rate of 25 to 50 g / min and reacted for a predetermined time. After the reaction, the produced composite tungsten oxide fine particles pass through the suction pipe 7 and are deposited on the filter 8 and are collected.
The carrier gas flow rate and the raw material supply rate greatly affect the generation time of the particles. Therefore, it is preferable to set the carrier gas flow rate to 6 L / min to 9 L / min and the raw material supply rate to 25 to 50 g / min.

Further, it is preferable to set the plasma gas flow rate to 30 L / min to 45 L / min and the sheath gas flow rate to 60 L / min to 70 L / min. The plasma gas has a function of maintaining a thermal plasma region having a high temperature portion of 10000 to 15000 K, and the sheath gas has a function of cooling the inner wall surface of the quartz torch in the reaction vessel to prevent melting of the quartz torch. At the same time, since the plasma gas and the sheath gas affect the shape of the plasma region, the flow rate of these gases is an important parameter for shape control of the plasma region. As the flow rate of the plasma gas and the sheath gas is increased, the shape of the plasma region extends in the gas flow direction and the temperature gradient of the plasma tail becomes gentle, so the generation time of generated particles is extended and particles with good crystallinity are generated. become able to.

The composite tungsten oxide obtained by the thermal plasma method has a crystallite diameter exceeding 200 nm, or the composite tungsten oxide particle dispersion obtained from the composite tungsten oxide obtained by the thermal plasma method When the dispersed particle diameter of the tungsten oxide exceeds 200 nm, the pulverization / dispersion treatment described later can be performed. When the composite tungsten oxide is synthesized by the thermal plasma method, the plasma conditions and the subsequent pulverization / dispersion treatment conditions are appropriately selected, and the average particle diameter, crystallite diameter and a axis of lattice constant of the composite tungsten oxide are selected. The effect of the present invention is exhibited by determining the pulverizing conditions (particulated conditions) to which the length and the c-axis length can be imparted.

(2) Solid Phase Reaction Method The solid phase reaction method will be described in the order of (i) raw materials used in the solid phase reaction method, (ii) calcination in the solid phase reaction method and conditions thereof.

(I) Raw Material Used for Solid Phase Reaction Method When synthesizing the composite tungsten oxide fine particles according to the present invention by the solid phase reaction method, a tungsten compound and an M element compound are used as a raw material.
Tungsten compounds are hydrolyzed by adding tungstic acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride, tungsten hexachloride dissolved in alcohol to water by adding water, and then evaporating the solvent, the hydrate of tungsten, It is preferable that it is 1 or more types chosen from.
In addition, a general formula MxWyOz (where M is one or more elements selected from Cs, Rb, K, Tl, and Ba), which is a more preferable embodiment, 0.001 ≦ x / y ≦ 1, 2.0 ≦ M element compounds used for producing the raw material of the composite tungsten oxide fine particles shown by z / y ≦ 3.0) include oxides, hydroxides, nitrates, sulfates, chlorides, and carbonates of M elements. It is preferable that it is 1 or more types chosen.

Further, a compound containing one or more impurity elements selected from Si, Al, and Zr (sometimes referred to as “impurity element compound” in the present invention) may be included as a raw material. The impurity element compound does not react with the composite tungsten compound in the later firing step, and suppresses the crystal growth of the composite tungsten oxide to prevent the coarsening of the crystal. The compound containing the impurity element is preferably at least one selected from oxides, hydroxides, nitrates, sulfates, chlorides, and carbonates, and colloidal silica and colloidal alumina having a particle diameter of 500 nm or less are particularly preferable. preferable.

The ratio of the M element to the W element of the tungsten compound and the aqueous solution containing the M element compound is MxWyOz (where M is the M element, W is the tungsten, O is oxygen, 0.001 ≦ x / y ≦ It wet mixes so that it may become a ratio of M element and W element of 1.0 and 2.0 <= z / y <= 3.0). When the impurity element compound is contained as a raw material, the impurity element compound is wet mixed so as to be 0.5% by mass or less. Then, the obtained mixed liquid is dried to obtain a mixed powder of the M element compound and the tungsten compound, or a mixed powder of the M element compound and the tungsten compound containing the impurity element compound.

(Ii) Firing in the solid phase reaction method and conditions thereof A mixed powder of an M element compound and a tungsten compound produced by the wet mixing, or a mixed powder of an M element compound and an tungsten compound containing an impurity element compound The firing is performed in one step under an atmosphere of active gas alone or a mixed gas of an inert gas and a reducing gas. The firing temperature is preferably close to the temperature at which the composite tungsten oxide fine particles begin to crystallize, and specifically, the firing temperature is preferably 1000 ° C. or less, more preferably 800 ° C. or less, 800 ° C. or less 500 ° C. The above temperature range is more preferable.

The reducing gas is not particularly limited, but H ₂ is preferable. When H ₂ is used as the reducing gas, its concentration may be appropriately selected according to the calcination temperature and the amount of the starting material, and is not particularly limited. For example, it is 20% by volume or less, preferably 10% by volume or less, more preferably 7% by volume or less. If the concentration of the reducing gas is 20% by volume or less, it is possible to avoid the generation of WO ₂ having no solar radiation absorbing function by rapid reduction. At this time, the average particle diameter, the crystallite diameter, and the a-axis length and c-axis length of the lattice constant of the composite tungsten oxide fine particles according to the present invention can be set to predetermined values by controlling the firing conditions.
However, in the synthesis of the composite tungsten oxide fine particles, tungsten trioxide may be used instead of the tungsten compound.

(3) Synthesized composite tungsten oxide fine particles When a composite tungsten oxide fine particle dispersion described later is produced using composite tungsten oxide fine particles obtained by a synthesis method by a thermal plasma method or a solid phase reaction method, When the dispersed particle diameter of the fine particles contained in the dispersion exceeds 200 nm, it may be ground and dispersed in the process of producing the composite tungsten oxide fine particle dispersion described later. If the average particle diameter, crystallite diameter, and a-axis length and c-axis length of the lattice constant of the composite tungsten oxide fine particles obtained through the pulverization and dispersion treatment can realize the range of the present invention, the present invention The composite tungsten oxide fine particle dispersion according to the present invention and the composite tungsten oxide fine particle dispersion obtained from the dispersion thereof can realize excellent near infrared absorption characteristics.
As described above, the composite tungsten oxide fine particles according to the present invention have an average particle diameter of 100 nm or less.
Here, when the average particle diameter of the composite tungsten oxide fine particles obtained by the method described in “[b] Synthesis method of composite tungsten oxide fine particles” exceeds 100 nm, it is pulverized and dispersed into fine particles. A process of producing a composite tungsten oxide fine particle dispersion (grinding / dispersion treatment process), and drying the produced composite tungsten oxide fine particle dispersion to remove volatile components (mostly solvents); Composite tungsten oxide particles according to the invention can be produced.

As drying equipment, from the viewpoint that heating and / or depressurization is possible and mixing and recovery of the fine particles are easy, an air drier, a universal mixer, a ribbon mixer, a vacuum flow drier, a vibration flow drier Preferred are, but not limited to, machines, lyophilizers, ribocones, rotary kilns, spray dryers, Palcon dryers, and the like.

[C] Composite tungsten oxide fine particle dispersion
The composite tungsten oxide fine particle dispersion for producing the agricultural and horticultural soil covering film according to the present invention will be described.
The composite tungsten oxide fine particle dispersion is selected from the composite tungsten oxide fine particles obtained by the above synthesis method, water, an organic solvent, a liquid resin, a liquid plasticizer for plastic, a polymer monomer, or a mixture of these. The liquid medium of the mixed slurry and an appropriate amount of dispersing agent, coupling agent, surfactant and the like are pulverized and dispersed by a medium stirring mill.
And, the dispersed state of the fine particles in the solvent is good, and the dispersed particle diameter is 1 to 200 nm. Moreover, it is preferable that content of the composite tungsten oxide fine particle contained in this composite tungsten oxide fine particle dispersion liquid is 0.01 mass% or more and 80 mass% or less.
Hereinafter, with respect to the composite tungsten oxide fine particle dispersion according to the present invention, (1) solvent, (2) dispersant, (3) pulverizing / dispersing method, (4) dispersed particle diameter, (5) binder, other additives The order will be described.

(1) Solvent The liquid solvent used for the composite tungsten oxide fine particle dispersion is not particularly limited, and the coating conditions of the composite tungsten oxide fine particle dispersion, the coating environment, and the inorganic binder or resin binder added as appropriate It may be selected appropriately according to the situation. For example, the liquid solvent is water, an organic solvent, a fat and oil, a liquid resin, a liquid plasticizer for a medium resin, a polymer monomer, or a mixture thereof.

Here, as the organic solvent, various solvents such as alcohols, ketones, hydrocarbons, glycols and water systems can be selected. Specifically, alcohol solvents such as methanol, ethanol, 1-propanol, isopropanol, butanol, pentanol, benzyl alcohol and diacetone alcohol; ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone Solvents; Ester solvents such as 3-methyl-methoxy-propionate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol isopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene Glycol derivatives such as glycol ethyl ether acetate; , N- methyl formamide, dimethylformamide, dimethylacetamide, amides such as N- methyl-2-pyrrolidone; toluene, aromatic hydrocarbons such as xylene; ethylene chloride, etc. chlorobenzene can be used. Among these organic solvents, dimethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, toluene, propylene glycol monomethyl ether acetate, n-butyl acetate and the like are particularly preferable.

As fats and oils, vegetable fats and oils or vegetable origin fats and oils are preferable. Examples of vegetable oils include dry oils such as linseed oil, sunflower oil, soy sauce and eno oil, sesame oil, cottonseed oil, rapeseed oil, semi-dry oil such as soybean oil, rice bran oil and poppy seed oil, olive oil, palm oil, palm oil and dehydrated castor oil Etc. non-drying oil is used. As a compound derived from vegetable oil, fatty acid monoester, ether etc. which carried out the ester reaction of the fatty acid of vegetable oil and monoalcohol directly are used. In addition, commercially available petroleum solvents can also be used as fats and oils, for example, Isopar (registered trademark) E, Exsol (registered trademark) Hexane, Hexane, E, D30, D40, D60, D80, D95, D110 manufactured by ExxonMobil. , D130 and the like.

As liquid plasticizers for medium resins, known liquid plasticizers represented by organic acid ester type and phosphoric acid ester type can be used.

Here, as the liquid plasticizer, for example, a plasticizer that is a compound of a monohydric alcohol and an organic acid ester, an ester-based plasticizer such as a polyhydric alcohol organic acid ester compound, an organic phosphoric acid plasticizer, etc. The plasticizer which is a phosphoric acid type is mentioned, and as for all, what is liquid at room temperature is preferable. Among them, a plasticizer which is an ester compound synthesized from a polyhydric alcohol and a fatty acid is preferable.

The ester compound synthesized from polyhydric alcohol and fatty acid is not particularly limited. For example, glycol such as triethylene glycol, tetraethylene glycol, tripropylene glycol and the like, butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid And glycol ester compounds obtained by reaction with monobasic organic acids such as n-octylic acid, 2-ethylhexylic acid, pelargonic acid (n-nonylic acid) and decylic acid. In addition, ester compounds of tetraethylene glycol and tripropylene glycol with the monobasic organic compounds and the like can also be mentioned.
Among them, fatty acid esters of triethylene glycol such as triethylene glycol dihexanate, triethylene glycol di-2-ethyl butyrate, triethylene glycol di-octanate, triethylene glycol di-2-ethyl hexanonate and the like are preferable. is there. Fatty acid esters of triethylene glycol are preferred.

Moreover, although a polymer monomer is a monomer which forms polymer | macromolecule by superposition | polymerization etc., as a preferable polymer monomer used by this invention, a methyl methacrylate monomer, an acrylate monomer, and a styrene resin are used. A monomer etc. are mentioned.

The liquid solvents described above can be used alone or in combination of two or more. Furthermore, if necessary, an acid or an alkali may be added to these liquid solvents to adjust the pH.

(2) Dispersant Furthermore, in order to further improve the dispersion stability of the composite tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion and to avoid the coarsening of the dispersed particle size due to reaggregation, various dispersants Addition of surfactants, coupling agents, etc. is also preferred. Although the said dispersing agent, a coupling agent, and surfactant can be selected according to a use, it is preferable that it is group which has an amine, 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 to prevent aggregation, and have an effect of uniformly dispersing the composite tungsten oxide fine particles according to the present invention even in the infrared absorbing film. More desirable are polymeric dispersants having any of these functional groups in the molecule.

For such dispersants,
Nippon Lubrizol Corporation, SOLSPERSE (registered trademark) (same below) 3000, 5000, 9000, 11200, 12000, 13000, 13240, 13650, 13640, 16000, 17000, 18000, 20000, 21000, 24000 SC, 24000 GR, 26000, 27000 , 28000, 31845, 32000, 32500, 32500, 32300, 33500, 33500, 35100, 35200, 36600, 37500, 38500, 39000, 41000, 41090, 53095, 55000, 56000, 71000, 76500, J180, J200, M387 etc;
SOLPLUS (registered trademark) D510, D520, D530, D540, DP310, K500, L300, L400, R700, etc .;
Disperbyk (registered trademark) (the same as the following) -101, 102, 103, 106, 107, 108, 109, 110, 111, 112, 116, 130, 140, 142, 145, 154, 161, Bic Chemie Japan Ltd. 162, 163, 164, 165, 166, 167, 168, 170, 171, 174, 180, 182, 183, 184, 185, 190, 191, 192, 2000, 2001, 2009, 2020, 2025, 2050, 2050 2070, 2095, 2096, 2150, 2151, 2152, 2155, 2163, 2164;
Anti-Terra (registered trademark) (same below)-U, 203, 204, etc .;
BYK (registered trademark) (hereinafter the same)-P104, P104S, P1050, P9051, P9060, P9065, P9080, 051, 052, 053, 054, 055, 057, 063, 065, 066N, 067A, 087, 088, 141, 220S, 300, 302, 306, 307, 310, 315, 320, 322, 323, 325, 330, 331, 333, 337, 340, 346, 347, 348, 350, 354, 355, 358N, 361N, 370, 375, 377, 378, 380N, 381, 392, 410, 425, 430, 1752, 4510, 6919, 9076, 9077, W909, W935, W940, W961, W966, W969, W972, W980, W985, W99 , W996, W9010, Dynwet800, Siclean3700, UV3500, UV3510, UV3570 and the like;
EFKA (registered trademark) EFKA (registered trademark) (the same as the following) 2020, 2025, 3030, 3031, 3236, 4008, 4009, 4010, 4015, 4046, 4060, 4080, 7462, 4020, 4050, 4055 4300, 4310, 4320, 4400, 4401, 4402, 4303, 4300, 4320, 4340, 5066, 5220, 6220, 6225, 6230, 6700, 6780, 6782, 8503;
BASF Japan KK, JONCRYL (registered trademark) (the same as the following) 67, 678, 586, 611, 680, 682, 690, 819,-JDX 5050, etc .;
Otsuka Chemical Co., Ltd. TERPLUS (registered trademark) (same below) MD1000, D 1180, D 1130, etc .;
Ajinomoto Fine Techno Co., Ltd., Addisper (registered trademark) (the same applies hereinafter) PB-711, PB-821, PB-822, etc .;
Kushimoto Chemical Co., Ltd., Disparon (registered trademark) (the same as the following) 1751 N, 1831, 1850, 1860, 1934, DA-400 N, DA-703-50, DA-325, DA-375, DA-550, DA-705, DA-725, DA-1401, DA-7301, DN-900, NS-5210, NVI-8514L, etc .;
Alfon (registered trademark) (hereinafter the same) UC-3000, UF-5022, UG-4010, UG-4035, UG-4070, etc .;

(3) Pulverization / Dispersion Method The method for dispersing composite tungsten oxide fine particles in the dispersion liquid is not particularly limited as long as the composite tungsten oxide fine particles are uniformly dispersed in the dispersion without aggregation. However, in the crystal structure of the pulverized / composite tungsten oxide fine particles, the composite tungsten oxide fine particles while securing the a-axis in the range of 7.3850 Å to 7.4186 Å and the c-axis in the range of 7.5600 Å to 7.6240 Å. The average particle diameter of these particles is required to be prepared to be 100 nm or less, preferably 10 nm to 100 nm, more preferably 10 nm to 80 nm, and still more preferably 10 nm to 60 nm.

For example, a grinding and dispersion treatment method using an apparatus such as a bead mill, a ball mill, a sand mill, a paint shaker, and an ultrasonic homogenizer may be mentioned. Among them, it is preferable to grind and disperse with a medium stirring mill such as a bead mill, a ball mill, a sand mill, a paint shaker, etc. using media media such as beads, balls and Ottawa sand because the time required for the desired dispersed particle size is short. .
At the same time dispersion of the composite tungsten oxide fine particles in the dispersion liquid by pulverization / dispersion processing using a medium stirring mill, pulverization by the collision of the composite tungsten oxide fine particles or the collision of the medium with the fine particles also progresses The composite tungsten oxide fine particles can be further micronized and dispersed (i.e., crushed and dispersed).

At this time, from the viewpoint of exhibiting excellent infrared absorption characteristics in the particulate composite tungsten oxide fine particles dispersed, the lattice constant is such that the a axis is 7.3850 Å or more and 7.4186 Å or less, and the c axis is 7.5600 Å or more The pulverization / dispersion treatment conditions are adjusted so that the crystallite diameter is preferably 7.6 nm to 100 nm, more preferably 10 nm to 80 nm, and still more preferably 10 nm to 60 nm.

In the mechanical dispersion treatment process using these equipment, while the composite tungsten oxide particles are dispersed in the solvent simultaneously with the dispersion of the composite tungsten oxide particles in the fine particles, the composite tungsten oxide particles progress to be finely divided, and the composite tungsten oxide particles are The strain or deformation is imparted to the crystal structure of the hexagonal crystal contained in, and the overlapping state of the electron orbitals in the atoms constituting the crystallite structure changes, and the increase of the amount of free electrons proceeds.

The micronization of the composite tungsten oxide particles and the fluctuation of the a-axis length and the c-axis length, which are lattice constants in the crystal structure of hexagonal crystals, differ depending on the apparatus constant of the pulverizing apparatus. Therefore, a pulverizing apparatus and pulverizing conditions capable of imparting a predetermined average particle diameter, crystallite diameter, a-axis length and c-axis length of lattice constant to composite tungsten oxide fine particles by performing experimental crushing beforehand It is important to seek.

When the composite tungsten oxide fine particles are dispersed in a plasticizer, it is also preferable to add an organic solvent having a boiling point of 120 ° C. or less, if desired.
Specific examples of the organic solvent having a boiling point of 120 ° C. or less include toluene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, isopropyl alcohol and ethanol. However, any particles can be selected as long as they can uniformly disperse fine particles exhibiting a near infrared absorption function at a boiling point of 120 ° C. or less. However, when the organic solvent is added, the drying step is carried out after the dispersion is completed, and the organic solvent remaining in the infrared light absorbing layer described later as an example of the near infrared light absorbing particle dispersion is 5% by mass or less Is preferred. If the residual solvent of the infrared light absorbing layer is 5% by mass or less, air bubbles are not generated in the agricultural and horticultural soil covering film to be described later, and the appearance and the optical characteristics can be favorably maintained.

The state of the composite tungsten oxide fine particle dispersion can be confirmed by measuring the dispersion state of the composite tungsten oxide fine particles when the tungsten oxide fine particles are dispersed in a solvent. For example, the composite tungsten oxide fine particles according to the present invention may be confirmed by sampling a sample from a solution in which fine particles and fine particles are present in a state of aggregation in a solvent and measuring them using various commercially available particle size distribution analyzers. it can. As the particle size distribution analyzer, for example, a known measuring device such as ELS-8000 manufactured by Otsuka Electronics Co., Ltd. based on the dynamic light scattering method can be used.

(4) Dispersed Particle Size The dispersed particle size of the composite tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion according to the present invention is preferably 200 nm or less, more preferably 200 nm or smaller. It is 1 nm or more.
This is because, when the agricultural and horticultural soil covering film finally obtained has a white light reflecting layer, it is necessary to consider the transparency of visible light visually in the infrared light absorbing layer. That is, the infrared light absorbing layer is required to efficiently absorb near infrared rays while maintaining the transparency of visible light.
The near-infrared absorbing component containing the composite tungsten oxide fine particles according to the present invention largely absorbs light in the near-infrared region, particularly, in the vicinity of a wavelength of 900 to 2200 nm. It may be greenish.
On the other hand, when the dispersed particle diameter of the composite tungsten oxide fine particles contained in the infrared ray absorbing layer is 1 to 200 nm, light in the visible light region of wavelength 380 nm to 780 nm is not scattered by geometric scattering or Mie scattering. The infrared ray absorbing layer reduces coloration due to light scattering, and can increase visible light transmittance. Furthermore, in the Rayleigh scattering region, the scattered light is reduced in proportion to the sixth power of the dispersed particle diameter, so the scattering is reduced as the dispersed particle diameter is reduced, and the transparency is improved. Therefore, when the dispersed particle size is 200 nm or less, the scattered light is extremely reduced and the transparency is further increased, which is preferable.
From the above, transparency can be ensured by setting the dispersed particle size of the fine particles smaller than 200 nm, but when importance is placed on the transparency, the dispersed particle size should be 150 nm or less, more preferably 100 nm or less. Is preferred. On the other hand, if the dispersed particle diameter is 1 nm or more, industrial production is easy.

Here, the dispersed particle diameter of the composite tungsten oxide particles in the composite tungsten oxide particle dispersion liquid will be briefly described. The dispersed particle size means a particle size of a single particle of composite tungsten oxide fine particles dispersed in a solvent, or a particle size of aggregated particles in which the composite tungsten oxide fine particles are aggregated, and various commercially available particles are available. It can be measured with a particle size distribution meter. For example, a sample of the composite tungsten oxide fine particle dispersion can be collected, and the sample can be measured using ELS-8000 manufactured by Otsuka Electronics Co., Ltd. based on the principle of dynamic light scattering.

In addition, the composite tungsten oxide fine particle dispersion having a content of 0.01% by mass or more and 80% by mass or less of the composite tungsten oxide microparticles obtained by the above synthesis method is excellent in liquid stability. When an appropriate liquid medium, dispersant, coupling agent or surfactant is selected, gelation of the dispersion or sedimentation of the particles does not occur for 6 months or more even when placed in a thermostatic chamber at a temperature of 40 ° C. The dispersed particle size can be maintained in the range of 1 to 200 nm.

The dispersed particle diameter of the composite tungsten oxide particle dispersion liquid may be different from the dispersed particle diameter of the composite tungsten oxide particles dispersed in the composite tungsten oxide particle dispersion. This is because even if the composite tungsten oxide fine particles are aggregated in the composite tungsten oxide fine particle dispersion, the composite tungsten oxide fine particles are processed from the composite tungsten oxide fine particle dispersion to the composite tungsten oxide fine particle dispersion, The cohesion of However, as the dispersed particle size of the composite tungsten oxide fine particle dispersion is smaller, the dispersed particle size of the near-infrared absorbing fiber tends to be smaller. Therefore, controlling the dispersed particle size of the composite tungsten oxide fine particle dispersion will be described later. It becomes important in controlling the characteristics of the near-infrared absorbing fiber obtained in the process.

(5) Binder, Other Additives The composite tungsten oxide fine particle dispersion may contain one or more selected from resin binders as appropriate. The type of resin binder to be contained in the composite tungsten oxide fine particle dispersion is not particularly limited, but thermoplastic resins such as acrylic resins, thermosetting resins such as epoxy resins, and the like can be applied.

In addition, in order to improve the near-infrared absorption characteristics of the composite tungsten oxide fine particle dispersion according to the present invention, a general formula XBm (wherein X is an alkaline earth element or a rare earth element containing yttrium) is added to the dispersion according to the present invention. It is also preferable to appropriately add a metal element selected from the above, a boride represented by 4 ≦ m ≦ 6.3), and a near infrared absorbing fine particle such as ATO or ITO, as desired. In addition, what is necessary is just to select the addition ratio at this time suitably according to the desired near-infrared absorption characteristic.
In addition, in order to adjust the color tone of the composite tungsten oxide fine particle dispersion, known inorganic pigments such as carbon black and red ink and known organic pigments can also be added.
The composite tungsten oxide fine particle dispersion may be added with a known ultraviolet absorber, a known infrared absorber of an organic substance, or a phosphorus-based color protection agent.

[D] Soil covering film for agricultural and horticultural purposes An agricultural and horticultural soil covering film according to the present invention will be described.
The sunlight reaching the surface is generally said to be in the wavelength range of about 290-2100 nm. Among these, light in the visible light wavelength range of about 380 to 780 nm is light necessary for plant growth. Therefore, the light in the visible light wavelength range of about 380 to 780 nm is reflected, and only the near infrared light of about 780 to 2100 nm in wavelength is selectively and efficiently absorbed to make visible light necessary for plant growth. It is preferable that the temperature of the atmosphere in the greenhouse is not raised by reflecting on the plant side and absorbing infrared light as heat to warm the soil.

The agricultural and horticultural soil covering film according to the present invention may have, for example, a configuration in which infrared absorbing material fine particles are coated on at least one surface of the agricultural and horticultural soil covering film to provide an infrared absorbing layer, You may provide the structure which disperse | distributes and makes infrared absorption material microparticles | fine-particles exist inside the film of an earth covering film.

The soil covering film for agriculture and horticulture according to the present invention may be further provided with a white light reflecting layer in which a white light reflecting material is dispersed inside.
The infrared light absorbing material may be provided by coating the infrared light absorbing material particles on at least one surface of the film provided with the white light reflecting layer, and the white light reflecting material and the infrared light absorbing material particles may be provided. May be dispersed inside the film to form a white light reflecting layer and an infrared light absorbing layer.
In addition, a white light reflection layer coated with a white light reflection material is provided on one side of the film, and further, infrared light absorption material particles are coated on the white light reflection layer to provide an infrared light absorption layer. It is good.
Alternatively, a white light reflecting layer coated with a white light reflecting material may be provided on one side of the film, and an infrared light absorbing layer coated with infrared light absorbing material fine particles may be provided on the other side of the film. .
In the above-mentioned configuration, since the infrared light absorbing layer is not colored due to the fine particles of the infrared absorbing material, the white reflective layer of the agricultural and horticultural coated film according to the present invention is infrared even if the white reflective layer is further provided. It is not colored by the light absorption layer.

In the soil covering film for agriculture and horticulture according to the present invention, the infrared ray absorbing material fine particles absorb solar heat due to sunshine, whereby the infrared ray is absorbed by the film, the film temperature rises, and the radiation heat increases accordingly. As a result, although the temperature of the inside of the soil coated with the agricultural and horticultural soil covering film rises quickly, the temperature of the atmosphere in the greenhouse does not rise. In addition, since the visible light is reflected by the white light reflecting material of the agricultural and horticultural soil covering film according to the present invention, the amount of visible light striking the plant is increased to increase the amount of photosynthesis and promote the growth of the plant.

As a method of applying the infrared absorbing material fine particles according to the present invention, first, the fine particles are dispersed in an appropriate medium, and a medium on which the fine particles are dispersed is coated on a desired substrate surface to form an infrared light absorbing layer. There is a way. In this method, it is possible to knead the fine particles of the infrared-absorbing material obtained by firing at a high temperature in advance into the film substrate, or to bind the substrate surface by a binder. As a result, application to a base material having a low heat resistance temperature, such as a resin material, is possible, and there is an advantage that it does not require a large apparatus when forming an infrared light absorption layer, and is inexpensive.

Further, since the infrared absorbing material fine particle according to the present invention is a conductive material, when the fine particles are connected to form a continuous film, there is a fear that the radio wave of a mobile phone or the like is absorbed and reflected and disturbed. is there. However, when the infrared absorbing material is dispersed as fine particles in the matrix, each infrared absorbing material particle is dispersed in an isolated state, so that radio wave transparency can be exhibited and it has versatility. ing.

As described above, when the infrared ray absorbing material particles are formed by coating the infrared ray absorbing material fine particles on one side of the film base in which the white light reflecting material is dispersed inside:
In the case where a white light reflecting material is coated on one side of a film substrate to form a white light reflecting layer, and further, infrared light absorbing material particles are coated on the white light reflecting layer to form an infrared light absorbing layer,
In the case where a white light reflecting material is coated on one side of a film substrate to form a white light reflecting layer, and infrared light absorbing material particles are coated on the other side to form an infrared light absorbing layer,
In the above case, for example, the infrared absorbing material fine particles are dispersed in an appropriate solvent, and after adding a resin binder thereto, the film is coated on the surface of the film substrate and the solvent is evaporated to cure the resin by a predetermined method By doing this, it is possible to form a thin film of an infrared light absorbing layer in which the infrared absorbing material fine particles are dispersed in the medium.

The coating method of the infrared ray absorbing material fine particles on the film base material surface is not particularly limited as long as the resin containing the infrared ray absorbing material fine particles can be uniformly coated on the film base material surface. For example, a bar coating method, a gravure coating method, a spray coating method, a dip coating method, a flow coating method, a spin coating method, a roll coating method, a screen printing method, a blade coating method and the like are preferably mentioned. In addition, when a coating liquid in which infrared light absorbing material fine particles are directly dispersed in a binder resin is used, there is no need to evaporate the solvent after the coating liquid is applied to the surface of the film substrate, which is environmentally preferable industrially.

As a resin binder mentioned above, UV cured resin, thermosetting resin, electron beam cured resin, normal temperature cured resin, thermoplastic resin etc. can be selected according to the objective, for example.
Specifically, polyethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polystyrene resin, polypropylene resin, ethylene vinyl acetate copolymer, polyester resin, polyethylene terephthalate resin, fluorine resin, polycarbonate resin, acrylic resin And polyvinyl butyral resins.
Moreover, utilization of the binder using a metal alkoxide is also possible. As the metal alkoxide, alkoxides such as Si, Ti, Al, Zr and the like are representative. The binder using the metal alkoxide can form an oxide film by hydrolysis and heating.

Further, as described above, the infrared absorbing material fine particles may be dispersed inside the film base in which the white light reflecting material is dispersed.
Specifically, the fine particles may penetrate from the surface of the film substrate. In addition, after heating and melting the base material resin to a melting temperature or higher, the infrared absorbing material fine particles and the molten base resin may be mixed. Alternatively, a heat-ray absorbing component-containing master batch may be prepared in advance, in which the fine particles are contained in a high concentration in the base material resin, and this may be adjusted to a predetermined concentration.
The infrared ray absorbing material fine particle-containing resin obtained as described above is formed into a film by a predetermined method, and can be used as an infrared ray absorbing material.

The heat ray absorbing component-containing masterbatch described above will be further described.
The method for producing the masterbatch is not particularly limited. For example, a composite tungsten oxide fine particle dispersion, particles or pellets of thermoplastic resin, and other additives as required, a ribbon blender, tumbler, While removing the solvent using mixers such as Nauta mixer, Henschel mixer, super mixer, planetary mixer etc., and kneaders such as Banbury mixer, kneader, roll, kneader ruder, single screw extruder, twin screw extruder etc. By uniformly melting and mixing, it is possible to prepare a molten mixture in which the fine particles are uniformly dispersed in a thermoplastic resin.
On the other hand, the solvent of the composite tungsten oxide fine particle dispersion is removed by a known method, and the obtained composite tungsten oxide fine particle powder, powder particles or pellets of thermoplastic resin, and other additives as required It is also possible to prepare a molten mixture in which the composite tungsten oxide fine particles are uniformly dispersed in a thermoplastic resin, using a method of uniformly melting and mixing.
Alternatively, a powder of the composite tungsten oxide fine particles may be directly added to the thermoplastic resin and uniformly mixed to prepare a molten mixture.
The molten mixture obtained by the above-described method is kneaded with a pent type single- or twin-screw extruder and processed into pellets, whereby a heat-ray absorbing component-containing masterbatch can be obtained.

The method of dispersing the infrared absorbing material fine particles in the resin is not particularly limited, and for example, ultrasonic dispersion, medium stirring mill, ball mill, sand mill and the like can be preferably used.
The dispersion medium for the fine particles used in the above-mentioned dispersion operation is not particularly limited. It can be selected according to the medium resin binder to be compounded, and various common organic solvents such as water, alcohol, ether, ester, ketone, aromatic compound, etc. can be used. Moreover, you may add an acid and an alkali and may adjust pH as needed. Furthermore, in order to further improve the dispersion stability of the infrared ray absorbing material fine particles, various surfactants, coupling agents and the like can be added.

The white light reflecting material used for the agricultural and horticultural soil covering film according to the present invention is not particularly limited. Specifically, for example, TiO ₂ , ZrO ₂ , SiO ₂ , Al ₂ O ₃ , MgO, ZnO, CaCO ₃ , BaSO ₄ , ZnS, PbCO _{3 and the} like are preferable. These white light reflecting materials may be used alone or in combination of two or more.

The film used for the agricultural and horticultural soil covering film according to the present invention is not particularly limited. Specifically, for example, polyethylene, polypropylene, polyethylene terephthalate, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, tetrachlorotrifluoroethylene, polychloride Preferred are vinyl, polyvinylidene chloride, polyvinyl alcohol, polystyrene, ethylene vinyl acetate, and polyester resins. To these resins, additives such as stabilizers, stabilizing aids, antioxidants, plasticizers, lubricants and UV absorbers may be further added.

As described above in detail, the agricultural and horticultural soil covering film according to the present invention is a film having an infrared light absorbing layer containing infrared light absorbing material fine particles, and further contains a white light reflecting material. It may have a white light reflecting layer.
The soil covering film for agriculture and horticulture according to the present invention has high weather resistance and low cost, and efficiently absorbs near infrared rays from sunlight with a small amount of fine particles of infrared absorbing material. And when it further has a white light reflection layer, the agricultural soil coating film which reflects visible light can be provided.

By using the soil covering film for agriculture and horticulture according to the present invention on the ground where plants and the like are grown, the temperature of the coated ground rises to warm the soil, and the temperature of the atmosphere such as in the greenhouse does not rise. . And when it further has a white light reflection layer, it has the effect of reflecting the light of the visible light wavelength region necessary for the growth of plants to promote the growth of plants, which is extremely useful.

Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited thereto.
Further, for the measurement of the crystal structure, lattice constant and crystallite diameter of the composite tungsten oxide fine particles according to the present invention, composite tungsten oxide fine particles obtained by removing the solvent from the composite tungsten oxide fine particle dispersion were used. Then, the X-ray diffraction pattern of the composite tungsten oxide fine particles is measured by powder X-ray diffraction method (θ-2θ method) using a powder X-ray diffractometer (X'Pert-PRO / MPD manufactured by Spectras Co., Ltd. PANalytical) did. The crystal structure contained in the fine particles was identified from the obtained X-ray diffraction pattern, and the lattice constant and the crystallite diameter were calculated using the Rietveld method.

Example 1
A solution was obtained by dissolving 7.43 kg of cesium carbonate (Cs ₂ CO ₃ ) in 6.70 kg of water. The solution was added to 34.57 kg of tungstic acid (H ₂ WO ₄ ), sufficiently stirred and mixed, and then dried with stirring (the molar ratio of W to Cs is equivalent to 1: 0.33). The dried product was heated while supplying 5% by volume of H ₂ gas using N ₂ gas as a carrier, and baked at a temperature of 800 ° C. for 5.5 hours, and then the supplied gas was switched to only N ₂ gas. The mixture was cooled to room temperature to obtain composite tungsten oxide particles.

Acrylic polymer dispersant (acrylic dispersant having an amine value of 48 mg KOH / g and decomposition temperature of 250 ° C.) containing 10% by mass of the composite tungsten oxide particles and an amine-containing functional group (hereinafter referred to as “dispersant” Described as a)) 10% by mass and 80% by mass of toluene were weighed and loaded in a paint shaker (manufactured by Asada Iron Works Co., Ltd.) containing 0.3 mmφ ZrO ₂ beads and ground and dispersed for 10 hours Thus, a composite tungsten oxide fine particle dispersion according to Example 1 was prepared. At this time, pulverization / dispersion treatment was performed using 300 parts by mass of 0.3 mmφ ZrO ₂ beads with respect to 100 parts by mass of the mixture.

Here, the dispersion particle diameter of the composite tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion is observed for fluctuation of scattered light of laser using ELS-8000 manufactured by Otsuka Electronics Co., Ltd., and a dynamic light scattering method The autocorrelation function was determined by (photon correlation method), and the average particle size (hydrodynamic size) was calculated by the cumulant method, which was 70 nm.
In addition, as a setting of particle size measurement, the particle refractive index was set to 1.81, and the particle shape was non-spherical. Moreover, the background was measured using toluene, and the solvent refractive index was 1.50.
Further, when the lattice constant of the composite tungsten oxide fine particles obtained after removing the solvent from the composite tungsten oxide fine particle dispersion was measured, the a axis was 7.4071 Å and the c axis was 7.6188 Å. The crystallite diameter was 24 nm. And the crystal structure of a hexagonal crystal was confirmed. The above manufacturing conditions and measurement results are shown in Table 1. Table 1 also shows the manufacturing conditions and the measurement results according to Examples 2 to 19 described later.

Furthermore, visible light transmittance and near infrared absorption characteristics were measured as optical properties of the composite tungsten oxide fine particle dispersion, using a spectrophotometer U-4100 manufactured by Hitachi, Ltd. The measurement was performed by filling a solution obtained by diluting the composite tungsten oxide fine particle dispersion with toluene in a measurement glass cell of a spectrophotometer. The dilution with toluene was performed such that the visible light transmittance of the composite tungsten oxide fine particle dispersion after dilution was about 70%.
In the measurement, the incident direction of light of the spectrophotometer was a direction perpendicular to the measurement glass cell.
Furthermore, the light transmittance was measured also in the blank liquid which put only toluene which is a dilution solvent to the glass cell for the measurement, and made the measurement result the baseline of the light transmittance.

50 parts by mass of the composite tungsten oxide fine particle dispersion according to Example 1 and 30 parts by mass of an ultraviolet curable resin (solid content 100%) for hard coat were mixed to obtain an infrared absorbing material fine particle dispersed body fluid. The obtained infrared light absorbing material fine particle-dispersed body fluid was applied onto a polyethylene film containing TiO ₂ fine particles as a white light reflecting material using a bar coater to form a film. The film was dried at 60 ° C. for 30 seconds to evaporate the solvent and then cured with a high pressure mercury lamp to obtain an infrared absorbing film according to Example 1 having a high diffuse reflectance in the visible light region.
In Example 1, an infrared absorbing film was provided on the film as an infrared absorbing layer. The same applies to Examples 2 to 19 and Comparative Examples 1 to 9 below.

The average particle diameter of the composite tungsten oxide fine particles dispersed in the obtained infrared absorbing film according to Example 1 was calculated by an image processing apparatus using a transmission electron microscope image. Then, the average particle diameter of the fine particles was 25 nm, which was almost the same value as the above-mentioned crystallite diameter of 24 nm.

Further, the optical properties of the infrared absorbing film according to Example 1 obtained are measured by the transmittance of light with a wavelength of 200 to 2600 nm using a spectrophotometer U-4100 manufactured by Hitachi, Ltd., according to JIS A 5759: 2016. Visible light transmittance, solar radiation transmittance, visible light reflectance, solar radiation reflectance, solar radiation absorptivity were calculated (here, the solar radiation absorptivity is the solar radiation absorptivity (%) = 100%-solar radiation transmittance (%)- Calculated from solar reflectance (%).
The results are shown in Table 2. Table 2 also describes the results obtained in Examples 2 to 19.

[Examples 2 to 11]
Tungstic acid and cesium carbonate described in Example 1, or an ammonium metatungstate aqueous solution (50 wt% in terms of WO ₃ ) and cesium carbonate, and the molar ratio of W to Cs is 1: 0.21 to An infrared-absorbing film according to Examples 2 to 11 was obtained in the same manner as in Example 1 except that a predetermined amount was measured to be 0.37.
The optical properties of the obtained infrared absorbing films according to Examples 2 to 11 were evaluated in the same manner as Example 1. In each of the composite tungsten oxide fine particle samples, a hexagonal crystal structure was confirmed.
The production conditions and the evaluation results of these examples are described in Tables 1 and 2.

[Example 12]
Example 6 is the same as Example 1 except that in the production of the composite tungsten oxide particles described in Example 1, baking is performed at a temperature of 550 ° C. for 9.0 hours while supplying 5% H ₂ gas using N ₂ gas as a carrier. The infrared absorption film according to Example 12 was obtained.
The optical properties of the infrared ray absorbing film according to Example 12 obtained were evaluated in the same manner as Example 1. In the composite tungsten oxide fine particle sample, a hexagonal crystal structure was confirmed. The production conditions and the evaluation results of these examples are described in Tables 1 and 2.

[Example 13]
From the composite tungsten oxide fine particle dispersion described in Example 1, toluene was removed using a spray dryer, to obtain a composite tungsten oxide fine particle dispersed powder according to Example 13.
20 parts by mass of the composite tungsten oxide fine particle dispersed powder obtained is added to 80 parts by mass of polyethylene resin pellets, uniformly mixed by a blender, and then melt-kneaded by a twin-screw extruder to make extruded strands into pellets It was cut to obtain a masterbatch containing composite tungsten oxide fine particles.
Likewise, the TiO 2 ₁₀ parts by weight, were added to 90 parts by weight of polyethylene resin pellets, were uniformly mixed in a blender, and melt-kneaded in a twin-screw extruder, and the extruded strand was cut into pellets, TiO ₂ To obtain a masterbatch containing
A masterbatch containing the obtained composite tungsten oxide fine particles, 50 parts by mass of a masterbatch containing TiO _2, and 50 parts by mass of a masterbatch to which inorganic fine particles melt-kneaded by the same method were not added . The mixed masterbatch was extruded to form a 50 μm thick film according to Example 13. The optical properties of this film were evaluated as in Example 1. In the composite tungsten oxide fine particle sample, a hexagonal crystal structure was confirmed.
The evaluation results are described in Table 2.

Example 14
50 parts by mass of the composite tungsten oxide fine particle dispersion described in Example 1 and 30 parts by mass of the ultraviolet curable resin (solid content 100%) for hard coat were mixed to obtain an infrared absorbing material fine particle dispersed body fluid.
Similarly, 50 parts by mass of TiO ₂ fine particles and 30 parts by mass of a UV curable resin for hard coating (solid content 100%) were mixed to obtain a white light reflecting material fine particle-dispersed body fluid containing TiO ₂ fine particles.
The obtained infrared ray absorbing material fine particle-dispersed body fluid was coated on a polyethylene film using a bar coater to form a film. The film was dried at 60 ° C. for 30 seconds, the solvent was evaporated, and then cured with a high pressure mercury lamp. Thereafter, a white light reflecting material fine particle dispersed body fluid was applied and formed into a film on the other side of the polyethylene film by the same method, and cured to form a film having a high diffuse reflectance in the visible light region according to Example 14. . The optical properties of this film were evaluated as in Example 1. In the composite tungsten oxide fine particle sample, a hexagonal crystal structure was confirmed.
The evaluation results are described in Table 2.

[Examples 15 to 19]
A solution was obtained by dissolving 5.56 kg of rubidium carbonate (Rb ₂ CO ₃ ) in 6.70 kg of water. The solution was added to 36.44 kg of tungstic acid (H ₂ WO ₄ ), sufficiently stirred and mixed, and then dried with stirring to obtain a dried product according to Example 15 (molar ratio between W and Rb Is equivalent to 1: 0.33).

A solution was obtained by dissolving 0.709 kg of cesium carbonate (Cs ₂ CO ₃ ) and 5.03 kg of rubidium carbonate (Rb ₂ CO ₃ ) in 6.70 kg of water. The solution was added to 36.26 kg of tungstic acid (H ₂ WO ₄ ), sufficiently stirred and mixed, and then dried with stirring to obtain a dried product according to Example 16 (molar ratio of W to Cs Is equivalent to 1: 0.03, and the molar ratio of W to Rb is equivalent to 1: 0.30).

A solution was obtained by dissolving 4.60 kg of cesium carbonate (Cs ₂ CO ₃ ) and 2.12 kg of rubidium carbonate (Rb ₂ CO ₃ ) in 6.70 kg of water. The solution was added to 35.28 kg of tungstic acid (H ₂ WO ₄ ), sufficiently stirred and mixed, and then dried with stirring to obtain a dried product according to Example 17 (molar ratio of W to Cs Is equivalent to 1: 0.20, and the molar ratio of W to Rb is equivalent to 1: 0.13).

A solution was obtained by dissolving 5.71 kg of cesium carbonate (Cs ₂ CO ₃ ) and 1.29 kg of rubidium carbonate (Rb ₂ CO ₃ ) in 6.70 kg of water. The solution was added to 35.00 kg of tungstic acid (H ₂ WO ₄ ), sufficiently stirred and mixed, and then dried with stirring to obtain a dried product according to Example 18 (molar ratio of W to Cs) Is equivalent to 1: 0.25, and the molar ratio of W to Rb is equivalent to 1: 0.08).

A solution was obtained by dissolving 6.79 kg of cesium carbonate (Cs ₂ CO ₃ ) and 0.481 kg of rubidium carbonate (Rb ₂ CO ₃ ) in 6.70 kg of water. The solution was added to 34.73 kg of tungstic acid (H ₂ WO ₄ ), sufficiently stirred and mixed, and then dried with stirring to obtain a dried product according to Example 19 (molar ratio of W to Cs) The molar ratio of W to Rb is equivalent to 1: 0.03.

The obtained dried products according to Examples 15 to 19 are heated while supplying 5% H ₂ gas using N ₂ gas as a carrier, and fired at a temperature of 800 ° C. for 5.5 hours, and then the supplied gas is used. Only the N ₂ gas was used, and the temperature was lowered to room temperature to obtain composite tungsten oxide particles according to Examples 15-19.

The infrared rays according to Examples 15 to 19 are operated in the same manner as in Example 1 except that the composite tungsten oxide particles according to Examples 15 to 19 are used instead of the composite tungsten oxide particles according to Example 1. An absorbent membrane was obtained.
The optical properties of the infrared ray absorbing films according to Examples 15 to 19 were evaluated in the same manner as Example 1. In each of the composite tungsten oxide fine particle samples, a hexagonal crystal structure was confirmed.
The production conditions and the evaluation results are shown in Tables 1 and 2.

[Comparative Examples 1 to 3]
Tungstic acid and cesium carbonate,
A predetermined amount was weighed so that the molar ratio of W and Cs would be 1: 0.11 (Comparative Example 1),
The predetermined amount was weighed so that the molar ratio of W and Cs would be 1: 0.15 (Comparative Example 2),
The predetermined amount was weighed so that the molar ratio of W and Cs would be 1: 0.39 (comparative example 3),
The infrared absorption film according to Comparative Examples 1 to 3 was obtained in the same manner as in Example 1 except for the above.
The optical properties of the infrared ray absorbing films according to Comparative Examples 1 to 3 were evaluated in the same manner as Example 1.
The manufacturing conditions and the evaluation results are shown in Tables 3 and 4.

[Comparative Examples 4 and 5]
Tungstic acid and cesium carbonate,
The predetermined amount was weighed so that the molar ratio of W and Cs would be 1: 0.21 (Comparative Example 4),
A predetermined amount is weighed so that the molar ratio of W and Cs is 1: 0.23 (Comparative Example 5),
An infrared absorbing film according to Comparative Examples 4 and 5 was obtained in the same manner as in Example 1 except that the baking was performed at a temperature of 400 ° C. for 5.5 hours.
The optical properties of the infrared absorbing films according to Comparative Examples 4 and 5 were evaluated in the same manner as Example 1.
The manufacturing conditions and the evaluation results are shown in Tables 3 and 4.

Comparative Example 6
Example 1 was repeated except that in the production of the composite tungsten oxide particle dispersion according to Example 1, the rotation speed of the paint shaker was 0.8 times that of Example 1, and 100 hours of grinding / dispersion treatment. The infrared absorption film according to Comparative Example 6 was obtained in the same manner as described above.
The optical properties of the infrared ray absorbing film according to Comparative Example 6 were evaluated in the same manner as Example 1.
The manufacturing conditions and the evaluation results are shown in Tables 3 and 4.

Comparative Example 7
Example 6 is the same as example 1 except that in the production of composite tungsten oxide particles according to example 1, baking is performed at a temperature of 440 ° C. for 5.5 hours while supplying 3 vol% H ₂ gas using N ₂ gas as a carrier. The infrared absorption film according to Comparative Example 7 was obtained.
The optical properties of the infrared ray absorbing film according to Comparative Example 7 were evaluated in the same manner as Example 1.
The manufacturing conditions and the evaluation results are shown in Tables 3 and 4.

Comparative Example 8
10% by mass of the composite tungsten oxide particles according to Example 1, 10% by mass of dispersant a, and 80% by mass of toluene are weighed and mixed by ultrasonic vibration for 10 minutes, and the operation is the same as Example 1. Then, a composite tungsten oxide fine particle dispersion liquid and an infrared absorption film according to Comparative Example 8 were obtained. That is, the composite tungsten oxide particles contained in the composite tungsten oxide fine particle dispersion according to Comparative Example 8 are not crushed.
The optical properties of the infrared ray absorbing film according to Comparative Example 8 were evaluated in the same manner as Example 1.
The manufacturing conditions and the evaluation results are shown in Tables 3 and 4.

Comparative Example 9
The composite tungsten oxide particles according to Example 1 are operated in the same manner as in Example 1 except that the rotation speed of the paint shaker is 1.15 times that of Example 1, and the grinding / dispersion treatment is performed for 25 hours. A composite tungsten oxide fine particle dispersion and an infrared absorption film according to Example 9 were obtained.
The optical properties of the infrared ray absorbing film according to Comparative Example 9 were evaluated in the same manner as Example 1.
The manufacturing conditions and the evaluation results are shown in Tables 3 and 4.

[Summary]
As is clear from the results of Tables 1 and 2 and Tables 3 and 4, the infrared ray absorbing films according to Examples 1 to 19 are compared with the infrared ray absorbing films according to Comparative Examples 1 to 9, and the sunlight, particularly the near infrared region It has been found that it blocks the light of the light more efficiently and at the same time maintains the high transmittance of the visible light region.
As apparent from Tables 2 and 4, when comparing Examples 1 to 19 and Comparative Examples 1 to 5, the infrared light absorbing layer formed by coating the composite tungsten oxide fine particles is formed into a white light in the film. By forming the film in which the reflective material is dispersed, it is found that the infrared light absorptivity of the film is greatly increased, the visible light is reflected, and the heat storage property is excellent. That is, in Examples 1 to 19, it was found that the reflectance of visible light can be maintained at about 60 to 70%, and the solar radiation absorptivity can be improved to about 40 to 60%.

The agricultural and horticultural soil covering films according to Examples 1 to 19 are films having a white light reflecting layer containing a white light reflecting material and an infrared light absorbing layer containing infrared light absorbing material fine particles.
Specifically, the white light reflection layer is a film in which a white light reflection material is dispersed inside, and has an infrared light absorption layer formed by coating infrared absorption material fine particles on one side of the film. White light on one side of a film, a film having a structure in which a white light reflecting material and infrared light absorbing material fine particles are dispersed inside the film to form a white light reflecting layer and an infrared light absorbing layer A film having a white light reflecting layer formed by coating a reflecting material, and an infrared light absorbing layer further formed by coating an infrared absorbing material fine particle on the white light reflecting layer, or A white light reflecting layer formed by coating a white light reflecting material on one side of the film, and an infrared absorbing material fine particle coated on the other side of the film A film structure having an external light-absorbing layer.

By forming an infrared light absorbing layer preferably containing composite tungsten oxide fine particles as infrared light absorbing material fine particles by the above-described simple configuration, the weather resistance is good, the cost is low, and the amount of fine particles is small. We were able to provide an agricultural and horticultural soil covering film that efficiently absorbs near infrared light from sunlight and reflects visible light.

 

 

 

 

 

 

 

 

1 Thermal plasma 2 High frequency coil 3 Sheath gas supply nozzle 4 Plasma gas supply nozzle 5 Raw material powder supply nozzle 6 Reaction vessel 7 Suction pipe 8 Filter

Claims (20)

An agricultural and horticultural soil covering film having an infrared light absorbing layer containing infrared light absorbing material fine particles,
The infrared absorbing material fine particles are composite tungsten oxide fine particles including a hexagonal crystal structure,
The lattice constant of the composite tungsten oxide fine particles is 7.3850 Å or more and 7.4186 Å or less for the a axis and 7.5600 Å or more and 7.6240 Å or less for the c axis.
An agricultural and horticultural soil covering film, wherein an average particle diameter of the composite tungsten oxide fine particles is 100 nm or less. The agricultural and horticultural products according to claim 1, wherein the complex tungsten oxide fine particles have a lattice constant of 7.4031 Å or more and 7.4111 Å or less and a c axis of 7.5891 Å or more and 7.6240 Å or less. Soil cover film. The soil covering film for agriculture and horticulture according to claim 1 or 2, wherein an average particle diameter of the composite tungsten oxide fine particles is 10 nm or more and 100 nm or less. 4. The composite tungsten oxide fine particles are dispersed and present in the resin binder of the infrared light absorbing layer provided on at least one surface of the agricultural and horticultural soil covering film. Soil cover film for agriculture and horticulture described in any of the above. The agricultural and horticultural covered film according to any one of claims 1 to 4, wherein the composite tungsten oxide fine particles are dispersed and present inside the film for agricultural and horticultural covered soil film. The coated film for agriculture and horticulture according to any one of claims 1 to 5, wherein a crystallite diameter of the composite tungsten oxide fine particles is 10 nm or more and 100 nm or less. The composite tungsten oxide fine particles have a 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, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb, W being tungsten, O being oxygen, 0.001 ≦ x / y The agricultural and horticultural coated film according to any one of claims 1 to 6, which is a composite tungsten oxide fine particle represented by ≦ 1, 2.0 ≦ z / y ≦ 3.0). The agricultural and horticultural coated film according to claim 7, wherein the M element is one or more elements selected from Cs and Rb. At least a part of the surface of the composite tungsten oxide fine particles is covered with a surface coating film containing at least one or more elements selected from Si, Ti, Zr, and Al. An agricultural and horticultural soil covering film according to any one of Items 1 to 8. 10. The agricultural and horticultural soil covering film according to claim 9, wherein the surface covering film contains an oxygen atom. The film is made of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, tetrachlorotrifluoroethylene, polyvinyl chloride, poly The agricultural and horticultural coated film according to any one of claims 1 to 10, which is at least one selected from vinylidene chloride, polyvinyl alcohol, polystyrene, ethylene vinyl acetate, and polyester resin. The agricultural and horticultural coated film according to any one of claims 1 to 11, further comprising a white light reflective layer in which a white light reflective material is dispersed inside the agricultural and horticultural coated film. A white light reflecting layer coated with a white light reflecting material on one side of the agricultural and horticultural soil covering film, and an infrared light absorbing layer further coated with infrared light absorbing material fine particles on the white light reflecting layer Have,
Alternatively, a white light reflecting layer coated with a white light reflecting material on one side of the agricultural and horticultural coated film, and an infrared ray coated with infrared light absorbing material particles on the other side of the agricultural and horticultural coated film. Having a light absorbing layer,
An agricultural and horticultural soil covering film according to any one of claims 1 to 12, characterized in that: The white light reflecting material is at least one selected from TiO ₂ , ZrO ₂ , SiO ₂ , Al ₂ O ₃ , MgO, ZnO, CaCO ₃ , BaSO ₄ , ZnS, and PbCO _3. An agricultural and horticultural soil covering film according to claim 12 or 13.
A method for producing an agricultural and horticultural soil covering film having an infrared light absorbing layer containing infrared light absorbing material fine particles,
The infrared absorbing material fine particles are composite tungsten oxide fine particles including a hexagonal crystal structure,
The composite tungsten oxide fine particles are manufactured so that the lattice constant is in the range of 7.3850 Å to 7.4186 Å in the a axis and 7.5600 Å to 7.6240 Å in the c axis.
A method for producing an agricultural and horticultural coated film, comprising performing a grinding and dispersing treatment step of setting the average particle diameter to 100 nm or less while maintaining the range of the lattice constant in the composite tungsten oxide fine particles. The composite tungsten oxide fine particles have a 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, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb, W being tungsten, O being oxygen, 0.001 ≦ x / y It is a composite tungsten oxide fine particle represented by <= 1 and 2.0 <= z / y <= 3.0), The manufacturing method of the covering film for agriculture and horticulture of Claim 15 characterized by the above-mentioned. The method for producing an agricultural and horticultural coated film according to claim 16, wherein the M element is one or more elements selected from Cs and Rb. 16. The method according to claim 15, wherein at least a part of the surface of the composite tungsten oxide fine particles is covered with a surface coating film containing at least one or more elements selected from Si, Ti, Zr, and Al. The manufacturing method of the covering film for agriculture and horticulture in any one of 17. The method for producing an agricultural / horticultural soil covering film according to claim 18, wherein the surface coating film contains an oxygen atom. The film for the agricultural and horticultural coating film is polyethylene, polypropylene, polyethylene terephthalate, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, tetrachlorotrifluoroethylene The film according to any one of claims 15 to 19, wherein the film comprises one or more resins selected from polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polystyrene, ethylene vinyl acetate and polyester resin. Production method of covered soil film for agriculture and horticulture.

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