Near-infrared absorption structure, resin film product composed of near-infrared absorption structure, fiber product and clothing, and method for using near-infrared absorption structure

Abstract

To provide a near-infrared absorption structure which shields heat rays of sunlight in summer, and is available for cold protection in winter, a resin film product which is composed of the near-infrared absorption structure, and a fiber product, clothing and a method for using a near-infrared absorption structure.SOLUTION: A near-infrared absorption structure 1 includes a first surface layer 11 containing near-infrared absorption particles, a second surface layer 12 containing no near-infrared absorption particle, and a hollow layer 14 which is provided on a first surface layer side of the second surface layer, wherein the near-infrared absorption particles are composite tungsten oxide fine particles which are represented by general formula, MxWyOz, and have a hexagonal crystal structure. When the side of the first surface layer 11 of the near-infrared absorption structure is put to sunlight irradiation in summer, the first surface layer 11 shields heat rays of sunlight, and when the side of the second surface layer 12 thereof is put to sunlight irradiation in winter, the first surface layer 11 is heated and available for cold protection.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a near-infrared absorbing structure that absorbs infrared rays and converts them into heat, and in particular to a near-infrared absorbing structure that can be used to block heat rays from sunlight in summer and to protect against the cold and retain heat in winter, a resin film product, a textile product and clothing made of this near-infrared absorbing structure, and a method for using the near-infrared absorbing structure. [Background technology]

[0002] Various near-infrared shielding technologies have been proposed so far that have good visible light transmittance and reduce solar radiation transmittance while maintaining transparency. Among them, near-infrared shielding technologies using inorganic conductive fine particles have the advantages of superior near-infrared shielding properties compared to other technologies, low cost, radio wave transmittance, and high weather resistance.

[0003] For example, Patent Document 1 discloses a technique relating to an infrared-shielding material microparticle dispersion in which composite tungsten oxide microparticles represented by the general formula MxWyOz (wherein M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, 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, and I, W is tungsten, O is oxygen, and 0.001≦x / y≦1, 2.2≦z / y≦3.0) are dispersed as infrared-shielding material microparticles in a medium such as a resin, and a method for producing the infrared-shielding material microparticles. Patent Document 1 also discloses an example of producing an infrared shielding film that is a thin-film dispersion of fine particles of an infrared shielding material.

[0004] According to Patent Document 1, it is possible to prepare an infrared-shielding material microparticle dispersion having excellent optical properties, such as more efficient shielding of sunlight, particularly light in the near-infrared region, while at the same time maintaining transmittance in the visible light region, etc. For this reason, application of the infrared-shielding material microparticle dispersion disclosed in Patent Document 1 to various applications such as window glass has been considered.

[0005] On the other hand, the composite tungsten oxide microparticles disclosed in Patent Document 1 have the property of absorbing infrared rays and generating heat. Patent Document 2 focuses on the above-mentioned property of the composite tungsten oxide microparticles and proposes a technology relating to a fiber that contains composite tungsten oxide microparticles inside the fiber and actively absorbs near-infrared rays to generate heat, and a cold weather textile product using the fiber. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2005 / 037932 [Patent Document 2] International Publication No. 2018 / 235839 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, the fibers and textile products disclosed in Patent Document 2 provide warmth to the human body when the fibers and textile products are in contact with the human body. Therefore, although they can be used to protect against the cold and to keep warm in winter, they provide only heat to the human body, which is problematic in that they cannot be used in summer.

[0008] The present invention has been made in view of these problems, and an object of the present invention is to provide a near-infrared absorbing structure that can be used to block heat rays from sunlight in the summer and to protect against the cold and retain heat in the winter, and to provide a resin film product, textile product, and clothing made of the near-infrared absorbing structure, and a method for using the near-infrared absorbing structure. [Means for solving the problem]

[0009] Therefore, in order to solve the above problems, the present inventors conducted the following technical studies.

[0010] First, the infrared shielding material fine particle dispersion disclosed in Patent Document 1 heats up when exposed to sunlight. Similarly, the textile product disclosed in Patent Document 2 also heats up when exposed to sunlight.

[0011] The textile product disclosed in Patent Document 2 provides warmth to the human body when it comes into contact with the human body, which is preferable in winter, but in summer, as mentioned above, it only provides heat to the human body.

[0012] On the other hand, since the infrared-shielding material microparticle dispersion disclosed in Patent Document 1 can shield light in the near-infrared region, even if the infrared-shielding material microparticle dispersion heats up when exposed to sunlight, if the infrared-shielding material microparticle dispersion can be modified and processed into a structure that does not directly contact the human body, the infrared-shielding material microparticle dispersion will not heat the human body even in summer.

[0013] The present invention has been completed through such technical investigations.

[0014] That is, the first invention according to the present invention is: A first surface layer containing near infrared absorbing particles; A second surface layer that does not contain near infrared absorbing particles; a hollow layer provided on a first surface layer side of the second surface layer or on an opposite side of the second surface layer from the first surface layer, The near infrared absorbing particles are characterized in that they are composite tungsten oxide microparticles represented by the general formula MxWyOz (wherein M is one or more elements selected from alkali metal elements, alkaline earth metal elements, rare earth elements, 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, and I, W is tungsten, and O is oxygen, 0.001≦x / y≦1, 2.0≦z / y≦3.0) and have a hexagonal crystal structure.

[0015] The second aspect of the present invention is In the near infrared absorbing structure according to the first aspect of the present invention, a joint portion where the first surface layer and the second surface layer are partially joined is provided between the first surface layer and the second surface layer, and a plurality of hollow layers partitioned by the joint portion are provided on the first surface layer side of the second surface layer, The third invention is In the near infrared absorbing structure according to the first aspect of the present invention, a spacer is interposed between the first surface layer and the second surface layer, and a plurality of hollow layers separated by the spacer are provided on the first surface layer side of the second surface layer; The fourth invention is In the near infrared absorbing structure according to the first aspect of the present invention, The present invention is characterized in that a hollow portion is provided on one surface of a second surface layer, the other surface of which is superimposed on the first surface layer, in a form in which the joining points are arranged all the way around, and a plurality of hollow layers formed by the hollow portion are provided on the opposite side of the second surface layer to the first surface layer.

[0016] Next, the fifth aspect of the present invention is In resin film products, The first surface layer and the second surface layer are made of a near-infrared absorbing structure according to the first aspect of the present invention, The sixth invention is In clothing, The resin film product according to the fifth aspect of the present invention is used, The seventh invention is In textile products, The first surface layer and the second surface layer are made of the near-infrared absorbing structure according to the first aspect of the present invention, The eighth invention is In clothing, The present invention is characterized by using the textile product according to the seventh aspect of the present invention.

[0017] Next, the ninth invention is, In the method for using the near infrared absorbing structure according to the first aspect of the present invention, The sheet is characterized in that in summer, the first surface layer side containing near-infrared absorbing particles is faced toward the side where sunlight is irradiated, thereby being used for blocking heat rays from sunlight, and in winter, the second surface layer side not containing near-infrared absorbing particles is faced toward the side where sunlight is irradiated, thereby being used for protection against the cold and for keeping warm. Effect of the Invention

[0018] According to the near-infrared absorbing structure of the present invention, A first surface layer containing near infrared absorbing particles; A second surface layer that does not contain near infrared absorbing particles; a hollow layer provided on the first surface layer side of the second surface layer or on the opposite side of the second surface layer to the first surface layer, The presence of the second surface layer not containing near infrared ray absorbing particles and the hollow layer makes it possible to provide a structure in which the first surface layer containing near infrared ray absorbing particles does not come into direct contact with the human body.

[0019] Therefore, in summer, the first surface layer is oriented in the direction of sunlight irradiation so that the first surface layer does not come into contact with the human body, thereby blocking the heat rays of sunlight, and in winter, the second surface layer is oriented in the direction of sunlight irradiation so that the first surface layer comes into contact with the human body, thereby providing a near-infrared absorbing structure that can be used for protection against the cold and for keeping warm, and also has the effect of providing resin film products, textile products, and clothing made of the near-infrared absorbing structure. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic perspective view of a near-infrared absorbing structure according to a first embodiment of the present invention. FIG. [Diagram 2] FIG. 11 is a front view of a near-infrared absorbing structure according to a modified example of the first embodiment. [Diagram 3] FIG. 4 is a schematic perspective view of a near-infrared absorbing structure according to a second embodiment of the present invention. [Figure 4] FIG. 11 is a front view of a second surface layer incorporated in the near-infrared absorbing structure according to the second embodiment. [Diagram 5] FIG. 5(A) is a schematic perspective view of a near-infrared absorbing structure according to a third embodiment of the present invention, and FIG. 5(B) is a plan view showing a hollow portion in which a joining point provided on the other surface of the second surface layer is arranged all the way around. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, embodiments of the present invention will be described in the order of [near infrared absorbing particles], [near infrared absorbing structure and method for using the same], [manufacturing method for a first surface layer made of a resin], and [manufacturing method for a first surface layer made of a fiber structure].

[0022] [Near infrared absorbing particles] The near-infrared absorbing particles contained in the first surface layer are composite tungsten oxide microparticles represented by the general formula MxWyOz (wherein M is one or more elements selected from alkali metal elements, alkaline earth metal elements, rare earth elements, 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, and I, W is tungsten, O is oxygen, 0.001≦x / y≦1, 2.0≦z / y≦3.0) and have a hexagonal crystal structure.

[0023] (1) Composite tungsten oxide particles In the above general formula MxWyOz, the M element, x, y, z and the crystal structure thereof are closely related to the free electron density of the composite tungsten oxide particles and have a significant effect on the near-infrared absorption properties.

[0024] Generally, tungsten trioxide (WO3) has poor near-infrared absorption characteristics because it does not have any available free electrons.

[0025] Therefore, the present inventors have found that by adding an M element (wherein M is one or more elements selected from alkali metal elements, alkaline earth metal elements, rare earth elements, 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, and I) to a tungsten oxide to form a composite tungsten oxide, free electrons are generated in the composite tungsten oxide, absorption characteristics derived from the free electrons are expressed in the near-infrared region, and the composite tungsten oxide becomes effective as a near-infrared absorbing material with a wavelength of around 1000 nm, and the composite tungsten oxide maintains a chemically stable state and becomes effective as a near-infrared absorbing material with excellent weather resistance. Furthermore, it has been found that the M element is preferably Cs, Rb, K, Tl, Ba, Cu, Al, Mn, or In, and that when the M element is Cs or Rb, the composite tungsten oxide is more likely to have a hexagonal crystal structure. As a result, the composite tungsten oxide transmits visible light and absorbs near infrared light, and is therefore particularly preferred for the reasons described below.

[0026] Here, the findings of the present inventors regarding the value of x, which indicates the amount of added M element, will be explained.

[0027] If the value of x / y is 0.001 or more, a sufficient amount of free electrons are generated, and the desired near-infrared absorption characteristics can be obtained. The more the amount of M element added, the more the supply of free electrons increases, and the near-infrared absorption characteristics also improve, but when the value of x / y is about 1, the effect is saturated. In addition, if the value of x / y is 1 or less, it is preferable because it is possible to avoid the generation of an impurity phase in the composite tungsten ultrafine particles.

[0028] Next, the findings of the present inventors regarding the value of z, which indicates the control of the amount of oxygen, will be described.

[0029] In the composite tungsten oxide microparticles 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≦3.0, even 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 WO2, which is not the intended purpose, in the composite tungsten oxide, and also to obtain chemical stability as a material, so that it can be applied as an effective infrared absorbing material. 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, making it an efficient infrared absorbing material.

[0030] (2) Crystal structure The composite tungsten oxide microparticles according to the present invention have a tungsten bronze structure of tetragonal and cubic crystals in addition to hexagonal crystals, and are effective as near-infrared absorbing materials in either structure. However, the absorption position in the near-infrared region tends to change depending on the crystal structure of the composite tungsten oxide microparticles. That is, the absorption position in the near-infrared region tends to move to the long wavelength side in the tetragonal crystals compared to the cubic crystals, and to the long wavelength side in the hexagonal crystals compared to the tetragonal crystals. In addition, accompanying the change in the absorption position, the absorption in the visible light region is the least in the hexagonal crystals, followed by the tetragonal crystals, and the cubic crystals are the most among them.

[0031] From the above findings, it is most preferable to use hexagonal tungsten bronze for applications requiring more transmission of light in the visible light region and more absorption of light in the near infrared region. When the composite tungsten oxide microparticles have a hexagonal crystal structure, the microparticles have improved transmission in the visible light region and improved absorption in the near infrared region.

[0032] In other words, in the composite tungsten oxide, if it is hexagonal tungsten bronze, it will exhibit excellent optical properties. In addition, if the composite tungsten oxide particles have an orthorhombic crystal structure or a WO 2 phase called the Magneli phase, 2.72 When it has a monoclinic crystal structure similar to that of the above, it has excellent infrared absorption properties and can be effective as a near-infrared absorbing material.

[0033] From the above findings, when composite tungsten oxide microparticles having a hexagonal crystal structure have a uniform crystal structure, the amount of M element added is preferably 0.2 or more and 0.5 or less in terms of the value of x / y, more preferably 0.29≦x / y≦0.39. Theoretically, when z / y=3, the value of x / y becomes 0.33, and it is considered that the M element is arranged in all of the hexagonal gaps. A typical example is Cs 0.33 WO3, Cs 0.03 Rb 0.30 WO3, Rb 0.33 WO3, K 0.33 WO3, Ba 0.33 Examples include WO3.

[0034] (3) Particle size When visible light is transmitted through the first and second surface layers described later, when the reduction of scattering by the composite tungsten oxide fine particles is important, the particle size is preferably 200 nm or less, more preferably 10 nm to 200 nm, and even more preferably 10 nm to 100 nm. This is because if the dispersed particle size is small, scattering of light in the visible light region of wavelengths of 400 nm to 780 nm due to geometric scattering or Mie scattering is reduced, and the first surface layer containing the composite tungsten oxide fine particles becomes like cloudy glass, which can avoid the problem of not being able to obtain clear transparency. That is, when the dispersed particle size is 200 nm or less, the geometric scattering or Mie scattering is reduced, and the Rayleigh scattering region is reached. In the Rayleigh scattering region, the scattered light is proportional to the sixth power of the dispersed particle size, so that the scattering is reduced and the transparency is improved as the dispersed particle size decreases. Furthermore, when the particle size is 100 nm or less, the scattered light is very small, which is preferable. From the viewpoint of avoiding light scattering, a smaller particle size is preferable, and a particle size of 1 nm or more facilitates industrial production.

[0035] Here, the particle size is the average diameter of individual non-aggregated composite tungsten oxide nanoparticles. The particle size can be calculated by measuring the diameters of 100 composite tungsten oxide nanoparticles observed in a TEM image and calculating the number average value.

[0036] (4) Method for producing composite tungsten oxide microparticles Composite tungsten oxide microparticles can be obtained by a solid-phase synthesis method in which starting materials, a tungsten source and an M element source, are placed in a container such as a crucible and heated, or by a gas-phase synthesis method in which the starting materials are introduced into a heated atmosphere such as an electric furnace, flame, plasma, or the like.

[0037] The starting material for the composite tungsten oxide microparticles may be a powder obtained by mixing one or more powders selected from tungsten trioxide powder, tungsten dioxide powder, or tungsten oxide hydrate, or tungsten hexachloride powder, or ammonium tungstate powder, or tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride in alcohol and then drying, or tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride in alcohol, adding water to precipitate the precipitate, and then drying the precipitate, or a tungsten compound powder obtained by drying an aqueous solution of ammonium tungstate, or metallic tungsten powder, with a powder of a simple substance or compound containing the M element.

[0038] Furthermore, when the tungsten compound, which is the starting material for obtaining the composite tungsten oxide microparticles, is in the form of a solution or dispersion, the elements can be easily mixed uniformly.

[0039] From this viewpoint, it is more preferable that the starting material for the composite tungsten oxide microparticles is a powder obtained by mixing an alcohol solution of tungsten hexachloride or an aqueous solution of ammonium tungstate with a solution of a compound containing an M element, and then drying the mixture.

[0040] Similarly, it is also preferable that the starting material for the composite tungsten oxide microparticles is a powder obtained by mixing a dispersion obtained by dissolving tungsten hexachloride in alcohol and then adding water to form a precipitate with a powder of a simple substance or compound containing the M element, or a solution of a compound containing the M element, and then drying the resulting powder.

[0041] Examples of compounds containing the above-mentioned M element include, but are not limited to, tungstates, chlorides, nitrates, sulfates, oxalates, oxides, carbonates, hydroxides, etc. of the M element, and any compound that can be in a solution state may be used. Furthermore, when manufacturing composite tungsten oxide microparticles industrially, using tungsten oxide hydrate powder or tungsten trioxide and carbonates or hydroxides of the M element is a preferred manufacturing method, since no harmful gases or the like are generated during the heat treatment stage or the like.

[0042] As an example of the conditions in the solid phase synthesis method, a heat treatment condition of 650°C or more is preferable. The starting material heat-treated at 650°C or more has sufficient near-infrared absorbing power and is efficient as composite tungsten oxide fine particles. As the inert gas, it is preferable to use an inert gas such as Ar or N2. As the heat treatment condition in the reducing atmosphere, it is preferable to first heat-treat the starting material in a reducing gas atmosphere at 100°C or more and 850°C or less, and then heat-treat it in an inert gas atmosphere at a temperature of 650°C or more and 1200°C or less. The reducing gas at this time is not particularly limited, but H2 is preferable. In addition, when H2 is used as the reducing gas, the composition of the reducing atmosphere is preferably H2 by volume ratio of 0.1% or more, more preferably 2% or more. If H2 is 0.1% or more by volume, reduction can be efficiently promoted.

[0043] [Near infrared absorbing structure and its use] The near infrared absorbing structure according to the present invention is A first surface layer containing near infrared absorbing particles; A second surface layer that does not contain near infrared absorbing particles; a hollow layer provided on the first surface layer side of the second surface layer or on the opposite side of the second surface layer to the first surface layer, The near infrared absorbing particles are characterized in that they are composite tungsten oxide microparticles represented by the general formula MxWyOz (wherein M is one or more elements selected from alkali metal elements, alkaline earth metal elements, rare earth elements, 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, and I, W is tungsten, and O is oxygen, 0.001≦x / y≦1, 2.0≦z / y≦3.0) and have a hexagonal crystal structure.

[0044] According to the near-infrared absorbing structure of the present invention, Since the first surface layer contains near-infrared absorbing particles composed of composite tungsten oxide fine particles, it blocks near-infrared rays from sunlight and generates heat when exposed to sunlight, while the heat generated by the first surface layer when exposed to sunlight is blocked by the insulating effect of the second surface layer that does not contain near-infrared absorbing particles and the hollow layer.

[0045] For this reason, when the near-infrared absorbing structure is used in clothing, in summer, by facing the first surface layer side containing the near-infrared absorbing particles toward the side where sunlight is irradiated, the heat rays of the sunlight are blocked by the first surface layer, and even if the first surface layer becomes hot, the second surface layer side which does not contain the near-infrared absorbing particles does not become hot due to the insulating effect of the hollow layer.

[0046] On the other hand, in winter, by facing the second surface layer side not containing near-infrared absorbing particles toward the side irradiated with sunlight, the first surface layer containing the near-infrared absorbing particles generates heat due to near-infrared rays from the sunlight that have transmitted through the second surface layer and the hollow layer, so the first surface layer side becomes warm.

[0047] Furthermore, even if the first surface layer and the second surface layer are formed of a fiber structure such as cloth, near-infrared rays contained in sunlight penetrate the second surface layer and the hollow layer to reach the first surface layer, and are absorbed by the near-infrared absorbing particles contained in the first surface layer, causing the first surface layer to generate heat.

[0048] Furthermore, if the near-infrared absorbing structure is used as a window curtain, it can function as a heat-shielding curtain in the summer and a heat-generating curtain in the winter, just like clothing.

[0049] Hereinafter, the near-infrared absorbing structure according to this embodiment will be specifically described with reference to the drawings.

[0050] (1) Near-infrared absorbing structure according to the first embodiment 1, the near-infrared absorbing structure 1 according to the first embodiment has a joint 13 between the first surface layer 11 and the second surface layer 12, where the first surface layer 11 containing near-infrared absorbing particles and the second surface layer 12 not containing near-infrared absorbing particles are partially joined, and a plurality of hollow layers 14 separated by the joint 13 are provided on the first surface layer 11 side of the second surface layer 12. Specifically, the second surface layer 12 is formed by a structure in which long curved portions having a substantially arc-shaped cross section are connected in the lateral direction, and the joint 13 is provided between the first surface layer 11 and the second surface layer 12 by joining the concave surface side end of the long curved portion to the first surface layer 11, and the plurality of hollow layers 14 separated by the joint 13, i.e., the plurality of hollow layers 14 surrounded by the concave surface of the long curved portion and the opposing surface of the first surface layer 11, are provided on the first surface layer 11 side of the second surface layer 12. The hollow layer 14 is configured as a long curved portion with both ends open as shown in Fig. 1, but may be configured as a long curved portion with both ends closed. The cross-sectional shape of the curved portion of the structure constituting the second surface layer 12 is not limited to the arc shape shown in Fig. 1, and may be any shape, such as a triangular or rectangular cross section, as long as the hollow layer 14 can be formed.

[0051] 1 is not more than twice the maximum distance between the first surface layer 11 and the second surface layer 12 in the hollow layer 14. This is because if the distance between the joints 13 is not more than twice the maximum distance between the first surface layer 11 and the second surface layer 12, the hollow layer 14 can be maintained.

[0052] (2) Near-infrared absorbing structure according to a modified example of the first embodiment 2, the near-infrared absorbing structure 1 according to the modified example of the first embodiment has a long spacer 15 interposed in each hollow layer 14 surrounded by the concave surface of the long curved portion and the opposing surface of the first surface layer 11, and each end of the long spacer 15 on the first surface layer 11 side and the long curved portion side is joined to the first surface layer 11 and the concave surface of the long curved portion, respectively. The distance between the joint 13 and the long spacer 15 shown in FIG. 2 is also not more than twice the maximum distance between the first surface layer 11 and the second surface layer 12 in the hollow layer 14.

[0053] (3) Near-infrared absorbing structure according to the second embodiment 3, the near-infrared absorbing structure 2 according to the second embodiment has a spacer 23 interposed between a first surface layer 21 containing near-infrared absorbing particles and a second surface layer 22 not containing near-infrared absorbing particles, and a plurality of hollow layers 24 separated by the spacer 23 are provided on the first surface layer 21 side of the second surface layer 22. Further, each end of the spacer 23 on the first surface layer 11 side and the second surface layer 22 is joined to the first surface layer 11 and the second surface layer 22, respectively.

[0054] The spacers 23 may be in a stripe shape, a lattice shape, or the like, as long as they can form the hollow layer 24. The spacers 23 may be curved or meandering. The interval between the spacers 23 is equal to or less than twice the maximum interval between the first surface layer 21 and the second surface layer 22 in the hollow layer 24. This is because the hollow layer 24 can be maintained if the interval between the spacers 23 is equal to or less than twice the maximum interval between the first surface layer 11 and the second surface layer 12.

[0055] In addition, in the near-infrared absorbing structure 2 according to the second embodiment shown in FIG. 3, the second surface layer 22 and the spacer 23 are configured as separate bodies, but the second surface layer 22 and the spacer 23 may be integrated as shown in FIG. 4.

[0056] (4) Near-infrared absorbing structure according to the third embodiment As shown in Fig. 5(A), the near-infrared absorbing structure 3 according to the third embodiment has a hollow portion 30 with a joining portion 33 arranged all around on one side of a second surface layer 32 that does not contain near-infrared absorbing particles and is superimposed on a first surface layer 31 that contains near-infrared absorbing particles, and the other side of the second surface layer 32 has a hollow portion 30 with a joining portion 33 arranged all around, and a plurality of hollow layers 34 formed by the hollow portion 30 are provided on the side of the second surface layer 32 opposite to the first surface layer 31. Fig. 5(B) is a plan view showing the hollow portion 30 with a joining portion 33 arranged all around on the other side of the second surface layer 32.

[0057] Furthermore, the interval between adjacent hollow layers 34 in the near-infrared absorbing structure 3 according to the third embodiment in which a plurality of hollow layers 34 are provided (corresponding to the "interval between joints" in the near-infrared absorbing structure according to the first or second embodiment) refers to the point where the interval between the joints 33 in the hollow portion 30 forming the hollow layers 34 is the longest. Note that a gas may be enclosed in the hollow layer 34 formed in the hollow portion 30.

[0058] (5) Maximum distance between the first surface layer and the second surface layer within the cavity The maximum distance between the first surface layer and the second surface layer in the hollow layer of the near-infrared absorbing structure according to the first and second embodiments may be 5 mm or more, preferably 10 mm or more, and more preferably 20 mm or more. If the maximum distance between the first surface layer and the second surface layer in the hollow layer is less than 5 mm, it is difficult to expect a heat insulating effect of the hollow layer.

[0059] Similarly, the maximum height of the hollow layer 34 in the near-infrared absorbing structure according to the third embodiment may be 5 mm or more, preferably 10 mm or more, and more preferably 20 mm or more. If the maximum height of the hollow layer 34 is less than 5 mm, it is difficult to expect the heat insulating effect of the hollow layer 34.

[0060] (6) Materials of the first surface layer, the second surface layer, and the spacer The first surface layer containing the near infrared absorbing particles can be formed of a resin or a fiber, and is preferably formed of a film-like resin or a fiber structure, thereby imparting flexibility to the first surface layer and the near infrared absorbing structure. Here, the fiber structure refers to a woven fabric, knitted fabric, nonwoven fabric, etc. obtained from fibers.

[0061] The second surface layer that does not contain near-infrared absorbing particles can also be formed from a resin or a fiber, and preferably is formed from a film-like resin or a fiber structure, thereby imparting flexibility to the second surface layer and thus to the near-infrared absorbing structure.

[0062] When the first surface layer and the second surface layer are formed of a film-like resin (i.e., a resin film), the thickness of the resin film is 5 μm or more and 250 μm or less. Although it depends on the material of the resin film, if the thickness is 5 μm or more, strength can be ensured, and if it is 250 μm or less, flexibility can be ensured. When the first surface layer and the second surface layer are formed of a fiber structure, the thickness of the fiber structure can be appropriately selected.

[0063] In addition, in the near-infrared absorbing structure according to the present embodiment, both the first surface layer and the second surface layer may be formed of a film-like resin or a fiber structure, or one surface layer may be formed of a film-like resin and the other surface layer may be formed of a fiber structure. The film-like resin or fiber structure forming the first surface layer and the second surface layer constituting the near-infrared absorbing structure according to the present embodiment may be made of the same resin material or fiber material. For example, when both the first surface layer and the second surface layer are formed of a fiber structure, the first surface layer may be formed of a synthetic fiber such as polyester, and the second surface layer may be formed of a natural fiber such as cotton.

[0064] Next, the spacer can be formed from a resin, a resin film, or a fiber structure, and the spacer can be joined between the first surface layer and the second surface layer using a known joining method such as joining using an adhesive, joining by thermal melting, sewing, etc.

[0065] In addition, when either the first surface layer or the second surface layer is formed of a resin or a film-like resin, a die capable of forming a surface layer provided with a spacer can be used. Fig. 4 is a front view of the second surface layer 22 with the spacer 23 integrated therewith as described above.

[0066] According to the near-infrared absorbing structures of the first, second and third embodiments, as shown in Fig. 1, Fig. 3 and Fig. 5(A), the first surface layer containing near-infrared absorbing particles and the second surface layer not containing near-infrared absorbing particles are unlikely to come into contact with each other. Therefore, when the first surface layer and the second surface layer are formed of a fiber structure such as a flexible resin film or fabric, even if the near-infrared absorbing structure according to these embodiments is bent, the first surface layer and the second surface layer will not come into complete contact with each other, and since hollow layers are scattered, the heat insulating effect due to the hollow layers is maintained.

[0067] [Method of manufacturing the first surface layer made of resin] Next, a method for producing the first surface layer made of a resin will be described.

[0068] To produce the first surface layer composed of a resin, first, a near-infrared absorbing particle dispersion is prepared, and then, a near-infrared absorbing particle dispersion (i.e., the first surface layer composed of a resin) is obtained by dispersing near-infrared absorbing particles in a resin medium using the near-infrared absorbing particle dispersion.

[0069] 1. Near infrared absorbing particle dispersion The near-infrared absorbing particle dispersion used in producing the near-infrared absorbing particle dispersion (that is, the first surface layer composed of a resin) can contain near-infrared absorbing particles (composite tungsten oxide particles) and a liquid medium.

[0070] (1) Liquid medium As the liquid medium, for example, one or more types selected from water, organic solvents, oils and fats, liquid resins, and liquid plasticizers can be used.

[0071] As the organic solvent, various solvents such as alcohols, ketones, esters, hydrocarbons, glycols, etc. can be selected. Specifically, alcohol solvents such as isopropyl alcohol, methanol, ethanol, 1-propanol, isopropyl alcohol, butanol, pentanol, benzyl alcohol, diacetone alcohol, 1-methoxy-2-propanol, etc.; ketone solvents such as dimethyl ketone, acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, etc.; ester solvents such as 3-methyl-methoxy-propionate, butyl acetate, etc.; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethyl Examples of the alkyl group include one or more selected from glycol derivatives such as propylene glycol isopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol methyl ether acetate, and propylene glycol ethyl ether acetate; amides such as formamide, N-methylformamide, dimethylformamide, dimethylacetamide, and N-methyl-2-propylidone; aromatic hydrocarbons such as toluene and xylene; and halogenated hydrocarbons such as ethylene chloride and chlorobenzene.

[0072] However, among these, organic solvents with low polarity are preferred, and in particular, isopropyl alcohol, ethanol, 1-methoxy-2-propanol, dimethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, toluene, propylene glycol monomethyl ether acetate, n-butyl acetate, etc. These organic solvents can be used alone or in combination of two or more kinds.

[0073] Examples of fats and oils that can be used include one or more selected from drying oils such as linseed oil, sunflower oil, and tung oil; semi-drying oils such as sesame oil, cottonseed oil, rapeseed oil, soybean oil, and rice bran oil; non-drying oils such as olive oil, coconut oil, palm oil, and dehydrated castor oil; fatty acid monoesters obtained by directly esterifying fatty acids of vegetable oils with monoalcohols; ethers; and petroleum-based solvents such as Isopar (registered trademark) E, Exxor (registered trademark) Hexane, Heptane, E, D30, D40, D60, D80, D95, D110, and D130 (all manufactured by ExxonMobil).

[0074] As the liquid resin, for example, one or more types selected from liquid acrylic resin, liquid epoxy resin, liquid polyester resin, liquid urethane resin, and the like can be used.

[0075] As the liquid plasticizer, for example, a liquid plasticizer for plastics can be used.

[0076] The components contained in the near infrared absorbing particle dispersion are not limited to the near infrared absorbing particles (composite tungsten oxide particles) and the liquid medium. The near infrared absorbing particle dispersion may further contain any optional components as required.

[0077] For example, an acid or an alkali may be added to the near infrared absorbing particle dispersion liquid as necessary to adjust the pH of the dispersion liquid.

[0078] In addition, in order to further improve the dispersion stability of the near infrared absorbing particles in the near infrared absorbing particle dispersion liquid described above and to prevent the dispersed particle size from becoming coarse due to re-aggregation, various surfactants, coupling agents, and the like can be added to the near infrared absorbing particle dispersion liquid as dispersants.

[0079] The dispersant such as the surfactant and coupling agent can be selected according to the application, but the dispersant preferably has one or more functional groups selected from an amine-containing group, a hydroxyl group, a carboxyl group, and an epoxy group. These functional groups adsorb to the surface of the near-infrared absorbing particles to prevent aggregation, and have the effect of uniformly dispersing the near-infrared absorbing particles even in a near-infrared absorbing particle dispersion containing the near-infrared absorbing particles. A polymer dispersant having one or more functional groups selected from the above functional groups (functional groups) in the molecule is more preferable.

[0080] Suitable commercially available dispersants include Solsperse (registered trademark) 9000, 12000, 17000, 20000, 21000, 24000, 26000, 27000, 28000, 32000, 35100, 54000, and 250 (manufactured by Lubrizol Japan Co., Ltd.), and EFKA (registered trademark). 4008, 4009, 4010, 4015, 4046, 4047, 4060, 4080, 7462, 4020, 4050, 4055, 4400, 4401, 4402, 4403, 4300, 4320, 4330, 4340, 6220, 6225, 6700, 6780, 6782, 8503 (manufactured by F-Ka Additives), AJISPER (registered trademark) PA111, PB821, PB822, PN411, Famex L-12 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), DisperBYK (registered trademark) 101, 102, 106, 108, 111, 116, 130, 140, 142, 145, 161, 162, 163, 164, 166, 167, 168, 170, 171, 174, 180, 182, 192, 193, 2000, 2001, 2020, 2025, 2050, 2070, 2155, 2164, 220S, 300, 306, 320, 322, 325, 330, 340, 350, 377, 378, 380N, 410, 425, 430 (manufactured by Pick Chemi-Japan Co., Ltd.), Disparon (registered trademark) Examples of the suitable polyimide resin include one or more selected from the group consisting of 1751N, 1831, 1850, 1860, 1934, DA-400N, DA-703-50, DA-725, DA-705, DA-7301, DN-900, NS-5210, and NVI-8514L (manufactured by Kusumoto Chemicals Co., Ltd.), Arfon (registered trademark) UC-3000, UF-5022, UG-4010, UG-4035, and UG-4070 (manufactured by Toagosei Co., Ltd.).

[0081] (2) Dispersion method of near-infrared absorbing particles in a liquid medium The method for dispersing the near infrared absorbing particles in the liquid medium is not particularly limited as long as the method can disperse the near infrared absorbing particles in the liquid medium. In this case, it is preferable that the near infrared absorbing particles can be dispersed so that the particle diameter is 200 nm or less, and more preferably, the near infrared absorbing particles can be dispersed so that the particle diameter is 1 nm or more and 200 nm or less.

[0082] Examples of the method for dispersing near-infrared absorbing particles in a liquid medium include dispersion methods using devices such as a bead mill, a ball mill, a sand mill, a paint shaker, and an ultrasonic homogenizer. Among them, it is preferable to pulverize and disperse using a media agitation mill such as a bead mill, a ball mill, a sand mill, or a paint shaker using a media (beads, balls, Ottawa sand) from the viewpoint of shortening the time required to obtain a desired average particle size. By the pulverization-dispersion treatment using a media agitation mill, the near-infrared absorbing particles are dispersed in a liquid medium, and at the same time, the near-infrared absorbing particles are atomized due to collisions between the near-infrared absorbing particles and collisions of the media with the near-infrared absorbing particles, and the near-infrared absorbing particles can be further atomized and dispersed. That is, the pulverization-dispersion treatment is performed.

[0083] As described above, the particle diameter of the near-infrared absorbing particles (composite tungsten oxide particles) is preferably 1 nm or more and 200 nm or less. This is because, if the particle diameter is small, scattering of light in the visible light region with a wavelength of 400 nm or more and 780 nm or less due to geometric scattering or Mie scattering is reduced. Furthermore, for example, the near-infrared absorbing particle dispersion (first surface layer composed of resin) in which the near-infrared absorbing particles are dispersed in a resin or the like obtained by using the near-infrared absorbing particle dispersion liquid of this embodiment becomes like cloudy glass, and it is possible to avoid not being able to obtain clear transparency. That is, when the particle diameter is 200 nm or less, the light scattering becomes weak in the geometric scattering or Mie scattering mode and becomes a Rayleigh scattering mode. In the Rayleigh scattering region, the scattered light is proportional to the sixth power of the dispersed particle diameter, so that the scattering is reduced and the transparency is improved as the dispersed particle diameter decreases. And, when the average particle diameter is 100 nm or less, the scattered light is very small, which is preferable.

[0084] The dispersion state of the near-infrared absorbing particles in the near-infrared absorbing particle dispersion obtained by using the near-infrared absorbing particle dispersion of the present embodiment, in which the near-infrared absorbing particles are dispersed in a solid medium such as a resin, does not result in aggregation greater than the average particle size of the near-infrared absorbing particles in the dispersion, as long as a known method for adding the dispersion to the solid medium is used.

[0085] In addition, when the particle diameter of the near-infrared absorbing particles is 0.1 nm or more and 200 nm or less, it is possible to prevent the produced near-infrared absorbing particle dispersion and its molded body (plate, sheet, etc.) from becoming grayish in color with a monotonically decreasing transmittance.

[0086] The content of the near-infrared absorbing particles (composite tungsten oxide particles) in the near-infrared absorbing particle dispersion according to this embodiment is not particularly limited, but is preferably, for example, 0.01% by mass or more and 80% by mass or less. This is because the content of the near-infrared absorbing particles is 0.01% by mass or more, and therefore sufficient solar radiation transmittance can be exhibited, that is, the solar radiation transmittance can be sufficiently suppressed. In addition, the content of the near-infrared absorbing particles is 80% by mass or less, and therefore the near-infrared absorbing particles can be uniformly dispersed in the dispersion medium.

[0087] 2. Near infrared absorbing particle dispersion (first surface layer made of resin) Next, a configuration example of the near infrared absorbing particle dispersion according to this embodiment (the first surface layer made of a resin) will be described.

[0088] The near infrared absorbing particle dispersion according to the present embodiment includes near infrared absorbing particles (composite tungsten oxide particles) and a solid medium. The near infrared absorbing particle dispersion according to the present embodiment will be described below in the order of (1) the shape of the solid medium and the near infrared absorbing particle dispersion, and (2) the manufacturing method of the near infrared absorbing particle dispersion.

[0089] (1) Shape of solid medium and near-infrared absorbing particle dispersion, etc. Examples of the solid medium include medium resins such as thermoplastic resins, thermosetting resins, and ultraviolet curing resins.

[0090] The specific material of the resin used for the solid medium is not particularly limited, but it is preferably one resin selected from the group consisting of polyester resin, polycarbonate resin, acrylic resin, styrene resin, polyamide resin, polyethylene resin, vinyl chloride resin, olefin resin, epoxy resin, polyimide resin, fluororesin, ethylene-vinyl acetate copolymer, polyvinyl acetal resin, and ultraviolet curing resin, or a mixture of two or more resins selected from the above group. As the polyester resin, polyethylene terephthalate resin can be preferably used.

[0091] These medium resins may also contain a polymeric dispersant having, in the main skeleton, one or more functional groups selected from an amine-containing group, a hydroxyl group, a carboxyl group, and an epoxy group.

[0092] The content ratio of near infrared absorbing particles in the near infrared absorbing particle dispersion according to this embodiment (the first surface layer composed of a resin) is not particularly limited, but the near infrared absorbing particle dispersion preferably contains near infrared absorbing particles in an amount of 0.001 mass % or more and 80 mass % or less.

[0093] The shape of the near infrared absorbing particle dispersion of this embodiment is not particularly limited, but the near infrared absorbing particle dispersion of this embodiment preferably has a sheet shape, a board shape, or a film shape, because the near infrared absorbing particle dispersion in the sheet shape, board shape, or film shape can be applied to various applications.

[0094] (2) Method for producing near-infrared absorbing particle dispersion A method for producing the near infrared absorbing particle dispersion according to this embodiment will be described below.

[0095] The near infrared absorbing particle dispersion of the present embodiment can be produced, for example, by using a master batch. In this case, the production method of the near infrared absorbing particle dispersion of the present embodiment can also include, for example, the following master batch production step.

[0096] In the masterbatch preparation step, a masterbatch in which near-infrared absorbing particles are dispersed in a solid medium can be prepared.

[0097] A specific method for producing the master batch is not particularly limited. For example, the master batch can be produced by dispersing a near infrared absorbing particle dispersion liquid or near infrared absorbing particles in a solid medium and pelletizing the solid medium.

[0098] As the near-infrared absorbing particles, a near-infrared absorbing particle dispersion powder obtained by removing the liquid medium from a near-infrared absorbing particle dispersion liquid can also be used.

[0099] For example, a near-infrared absorbing particle dispersion, near-infrared absorbing particles, near-infrared absorbing particle dispersion powder, solid medium powder or pellets, and other additives as necessary are uniformly mixed to prepare a mixture. The mixture is then kneaded in a vented single-screw or twin-screw extruder, and processed into pellets by cutting melt-extruded strands, thereby producing a master batch. In this case, the shape of the pellets can be cylindrical or prismatic. In addition, when producing pellets, it is also possible to use the so-called hot-cut method in which the melt-extruded material is directly cut. In this case, the pellets generally have a shape close to a sphere.

[0100] In the master batch preparation process, when a near infrared absorbing particle dispersion is used as a raw material, it is preferable to reduce or remove the liquid medium derived from the near infrared absorbing particle dispersion. In this case, the degree of removing the liquid medium contained in the near infrared absorbing particle dispersion is not particularly limited. For example, it is preferable to remove the liquid medium from the near infrared absorbing particle dispersion or the like to an amount that is allowed to remain in the master batch. In addition, when a liquid plasticizer is used as the liquid medium, the entire amount of the liquid plasticizer may remain in the near infrared absorbing particle dispersion.

[0101] There is no particular limitation on the method for reducing or removing the liquid medium contained in the near-infrared absorbing particle dispersion from the near-infrared absorbing particle dispersion or the mixture of the near-infrared absorbing particle dispersion and the solid medium. For example, it is preferable to carry out a drying step for drying the near-infrared absorbing particle dispersion under reduced pressure. Specifically, the near-infrared absorbing particle dispersion is dried under reduced pressure while stirring, and the near-infrared absorbing particle-containing composition and the liquid medium components are separated. An example of the device used for the reduced pressure drying is a vacuum stirring type dryer, but any device having the above function may be used, and is not particularly limited. In addition, the pressure value during the reduced pressure in the drying step is appropriately selected.

[0102] By using the reduced pressure drying method, the efficiency of removing the liquid medium derived from the near-infrared absorbing particle dispersion liquid is improved. In addition, the near-infrared absorbing particle dispersion powder obtained after the reduced pressure drying and the near-infrared absorbing particle dispersion liquid as the raw material are not exposed to high temperatures for a long time, so that the near-infrared absorbing particle dispersion powder and the near-infrared absorbing particles dispersed in the near-infrared absorbing particle dispersion liquid do not aggregate, which is preferable. Furthermore, the productivity of the near-infrared absorbing particle dispersion powder etc. is increased, and it is easy to recover the solvent such as the evaporated liquid medium, which is also preferable from the environmental consideration.

[0103] In the near infrared absorbing particle dispersion powder etc. obtained after the drying step, it is preferable to thoroughly remove the solvent component having a boiling point of 120°C or less. For example, it is preferable that the residual amount of the solvent component is 2.5 mass% or less. If the residual solvent component is 2.5 mass% or less, when the near infrared absorbing particle dispersion powder etc. is processed into, for example, a near infrared absorbing particle dispersion, no air bubbles are generated, and the appearance and optical properties are maintained in a good condition. In addition, if the residual solvent component in the near infrared absorbing particle dispersion powder is 2.5 mass% or less, aggregation due to natural drying of the residual solvent component does not occur during long-term storage in the near infrared absorbing particle dispersion powder state, and long-term stability is maintained.

[0104] By adding a solid medium and kneading the obtained master batch, the dispersion concentration can be adjusted while maintaining the dispersed state of the near-infrared absorbing particles contained in the master batch, which is a near-infrared absorbing particle dispersion.

[0105] Furthermore, the manufacturing method for the near infrared absorbing particle dispersion according to the present embodiment may include, as necessary, a molding step of molding the obtained master batch or the master batch to which a solid medium has been added as described above, to obtain a near infrared absorbing particle dispersion having a desired shape.

[0106] The specific method for molding the near infrared absorbing particle dispersion is not particularly limited, but for example, known methods such as extrusion molding and injection molding can be used.

[0107] In the molding step, for example, a near infrared absorbing particle dispersion can be produced in a flat or curved shape, such as a sheet shape, a board shape, or a film shape. The method for molding into a sheet shape, a board shape, or a film shape is not particularly limited, and various known methods can be used.

[0108] The method for producing the near infrared absorbing particle dispersion of the present embodiment is not limited to the embodiment having the above-mentioned master batch production step.

[0109] For example, the method for producing the near infrared absorbing particle dispersion of the present embodiment may have the following steps.

[0110] A precursor liquid preparation step of mixing a monomer, an oligomer, and an uncured liquid solid medium precursor of the solid medium with near-infrared absorbing particles, near-infrared absorbing particle dispersion powder, or near-infrared absorbing particle dispersion liquid to prepare a near-infrared absorbing particle dispersion precursor liquid.

[0111] A near-infrared absorbing particle dispersion preparation step in which the solid medium precursor such as the monomer is cured by a chemical reaction such as condensation or polymerization to prepare a near-infrared absorbing particle dispersion.

[0112] For example, when an acrylic resin is used as the solid medium, a near-infrared absorbing particle dispersion precursor liquid can be obtained by mixing an acrylic monomer or an acrylic ultraviolet curable resin with near-infrared absorbing particles.

[0113] Next, the near infrared ray absorbing particle dispersion precursor liquid is filled into a predetermined mold or the like and subjected to radical polymerization, thereby obtaining a near infrared ray absorbing particle dispersion using an acrylic resin.

[0114] When a resin that hardens by crosslinking is used as the solid medium, a dispersion can be obtained by subjecting a near infrared absorbing particle dispersion precursor liquid to a crosslinking reaction, similar to the case where the acrylic resin described above is used.

[0115] Alternatively, a coating liquid can be prepared by dissolving the above-mentioned resin in a near-infrared absorbing particle dispersion liquid, and the above-mentioned coating liquid is applied to a substrate such as a resin film prepared in advance, and the solvent in the coating liquid is removed by drying or the like to harden the coating liquid, thereby forming a dispersion on the surface of the substrate.

[0116] [Method of manufacturing the first surface layer composed of a fiber structure] Next, a method for producing the first surface layer made of a fiber structure will be described.

[0117] The fiber structure constituting the first surface layer means a structure containing near-infrared absorbing particles (composite tungsten oxide fine particles) on the fiber surface and / or inside.

[0118] (1) Fiber structure The fibers used in the fiber structure constituting the first surface layer can be selected from various types depending on the application, and any of synthetic fibers, semi-synthetic fibers, natural fibers, regenerated fibers, inorganic fibers, and mixed yarns obtained by blending, doubling, mixing, etc., of these may be used. Furthermore, in consideration of the incorporation of near-infrared absorbing particles (composite tungsten oxide particles) into the fibers by a simple method and the durability of heat retention, synthetic fibers are preferred.

[0119] (1-1) Synthetic fibers The synthetic fibers used in the fiber structure are not particularly limited, but examples thereof include polyurethane fibers, polyamide fibers, acrylic fibers, polyester fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, and polyether ester fibers.

[0120] For example, polyamide fibers include nylon, nylon 6, nylon 66, nylon 11, nylon 610, nylon 612, aromatic nylon, and aramid.

[0121] Examples of acrylic fibers include polyacrylonitrile, acrylonitrile-vinyl chloride copolymer, and modacrylic.

[0122] Examples of polyester fibers include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and polyethylene naphthalate.

[0123] Examples of polyolefin fibers include polyethylene, polypropylene, and polystyrene.

[0124] Further, for example, an example of polyvinyl alcohol-based fiber is vinylon.

[0125] Further, for example, polyvinylidene chloride fibers include vinylidene.

[0126] Further, for example, polyvinyl chloride fibers include polyvinyl chloride.

[0127] Further, examples of polyether ester fibers include Lexe and Success.

[0128] (1-2) Semi-synthetic fibers When the fibers used in the fiber structure are semi-synthetic fibers, examples of the fibers include cellulose-based fibers, protein-based fibers, chlorinated rubber, and hydrochloric rubber.

[0129] Further, examples of cellulosic fibers include acetate, triacetate, and acetate oxide.

[0130] Further, for example, an example of protein fiber is Promix.

[0131] (1-3) Natural fibers When the fibers used in the fiber structure are natural fibers, examples of the natural fibers include vegetable fibers, animal fibers, and mineral fibers.

[0132] Examples of plant fibers include cotton, kapok, flax, hemp, jute, Manila hemp, sisal, New Zealand hemp, ramie, palm, rush, and wheat straw.

[0133] Examples of animal fibers include wool such as sheep's wool, goat hair, mohair, cashmere, alpaca, angora, camel, and vicuna, as well as silk, down, and feathers.

[0134] Further, examples of mineral fibers include asbestos.

[0135] (1-4) Regenerated fibers When the fibers used in the fiber structure are regenerated fibers, examples of the regenerated fibers include cellulose-based fibers, protein-based fibers, alginate fibers, rubber fibers, chitin fibers, and mannan fibers.

[0136] Examples of cellulosic fibers include rayon, viscose rayon, cupro, polynosic, and cuprammonium rayon.

[0137] Further, examples of protein-based fibers include casein fiber, peanut protein fiber, corn protein fiber, soy protein fiber, and regenerated silk thread.

[0138] (1-5) Inorganic fibers When the fibers used in the fiber structure are inorganic fibers, examples thereof include metal fibers, carbon fibers, and silicate fibers.

[0139] Examples of metal fibers include metal fibers, gold threads, silver threads, and heat-resistant alloy fibers.

[0140] Examples of silicate fibers include glass fibers, slag fibers, and rock fibers.

[0141] (2) Cross-sectional shape of the fiber structure The cross-sectional shape of the fiber structure is not particularly limited, and examples thereof include circular, triangular, hollow, flat, Y-shaped, star-shaped, and sheath-core shapes. The inclusion of fine particles on the surface and / or inside of the fiber can be in various shapes, and for example, in the case of a sheath-core type, the fine particles may be contained in the core or sheath of the fiber. The shape of the infrared absorbing fiber may be a filament (long fiber) or a staple (short fiber).

[0142] In addition, the above-mentioned fiber structure can contain antioxidants, flame retardants, deodorants, insect repellents, antibacterial agents, ultraviolet absorbers, etc. depending on the purpose, as long as the performance of the fiber is not impaired.

[0143] (3) A method in which near-infrared absorbing particles are incorporated into the surface and / or interior of the fiber There is no particular limitation on the method of incorporating near-infrared absorbing particles (composite tungsten oxide particles) into the surface and / or inside of the fiber. For example, (A) the method of directly mixing the near-infrared absorbing particles into the raw polymer of the synthetic fiber and spinning the mixture; (B) the method of producing a master batch in which the near-infrared absorbing particles are incorporated in a high concentration in a part of the raw polymer in advance, and diluting and adjusting the master batch to a predetermined concentration at the time of spinning the mixture, and then spinning the mixture; (C) the method of uniformly dispersing the near-infrared absorbing particles in a raw monomer or oligomer solution in advance, synthesizing the target raw polymer using this dispersion solution, and at the same time, dispersing the near-infrared absorbing particles uniformly in the raw polymer, and then spinning the mixture; (D) the method of attaching the near-infrared absorbing particles to the surface of the fiber obtained by spinning in advance using a binder, etc.

[0144] Here, a preferred example of the method in which the master batch explained in (B) above is produced and then diluted and adjusted at the time of spinning, and then the mixture is spun will be described in detail below.

[0145] The method for producing the masterbatch is not particularly limited. For example, the near-infrared absorbing particle dispersion described above, powder or pellets of a thermoplastic resin, and other additives as necessary are uniformly melt-mixed while removing the solvent using a mixer such as a Riboblender, a tumbler, a Nauter mixer, a Henschel mixer, a super mixer, or a planetary mixer, or a kneader such as a Banbury mixer, a kneader, a roll, a kneader-ruder, a single-screw extruder, or a twin-screw extruder, to prepare the masterbatch as a mixture in which fine particles are uniformly dispersed in a thermoplastic resin.

[0146] Furthermore, after preparing the near infrared absorbing particle dispersion, the solvent of the dispersion is removed by a known method, and the obtained powder is uniformly melt-mixed with a thermoplastic resin powder or pellets, and other additives as necessary, to produce a mixture in which the fine particles are uniformly dispersed in the thermoplastic resin. In addition, a method of directly adding the near infrared absorbing particle powder to a thermoplastic resin and uniformly melt-mixing the mixture can also be used.

[0147] The mixture of the near infrared ray absorbing particles and the thermoplastic resin obtained by the above-mentioned method is kneaded in a pentagonal single-screw or twin-screw extruder and processed into pellets, thereby obtaining a master batch containing near infrared ray absorbing particles.

[0148] Here, the above-mentioned methods (A) to (D) will be specifically explained below.

[0149] Method (A): For example, when polyester fibers are used as the fibers, the near infrared absorbing particle dispersion is added to polyethylene terephthalate resin pellets, which is a thermoplastic resin, and mixed uniformly in a blender, and then the solvent is removed. The mixture from which the solvent has been removed is melt-kneaded in a twin-screw extruder to obtain a master batch containing near infrared absorbing particles. The obtained master batch containing near infrared absorbing particles is melt-mixed near the melting temperature of the resin, and spun according to a conventional method.

[0150] Method (B): In the same manner as in (A), except that a near-infrared absorbing particle-containing master batch prepared in advance is used, the near-infrared absorbing particle-containing master batch and a target amount of a master batch made of polyethylene terephthalate containing no added microparticles are melt-mixed at a temperature near the melting temperature of the resin, and spun in a conventional manner.

[0151] Method (C): For example, when using urethane fibers as the fibers, a polymer diol containing near-infrared absorbing particles (composite tungsten oxide particles) is reacted with an organic diisocyanate in a twin-screw extruder to synthesize an isocyanate-terminated prepolymer, which is then reacted with a chain extender to produce a polyurethane solution (raw polymer). The polyurethane solution is spun in the usual manner.

[0152] Method (D): For example, in order to attach near-infrared absorbing particles to the surface of natural fibers, a treatment liquid is first prepared by mixing near-infrared absorbing particles, at least one binder resin selected from acrylic, epoxy, urethane, and polyester, and a solvent such as water. Next, the natural fibers are immersed in the prepared treatment liquid, or the natural fibers are impregnated with the prepared treatment liquid by padding, printing, spraying, or the like, and then dried, thereby allowing the near-infrared absorbing particles to adhere to the natural fibers. Method (D) can be applied to any of the above-mentioned natural fibers, semi-synthetic fibers, regenerated fibers, inorganic fibers, or their blends, doubling yarns, and mixed fibers.

[0153] In carrying out the above methods (A) to (D), the method for dispersing the near-infrared absorbing particles (composite tungsten oxide microparticles) may be any method that can uniformly disperse the microparticles in a liquid. For example, methods such as a media stirring mill, a ball mill, a sand mill, and ultrasonic dispersion can be suitably applied.

[0154] In addition, the dispersion medium for the near infrared absorbing particles is not particularly limited and can be selected according to the fibers to be mixed. For example, various general organic solvents such as alcohols, ethers, esters, ketones, aromatic compounds, and the like, and water can be used.

[0155] Furthermore, when the near infrared ray absorbing particles are attached to or mixed with the fibers or the raw material polymer, the dispersion liquid of the near infrared ray absorbing particles may be directly mixed with the fibers or the raw material polymer. If necessary, the pH may be adjusted by adding an acid or an alkali to the dispersion liquid of the near infrared ray absorbing particles, and it is also preferable to add various surfactants, coupling agents, etc. to further improve the dispersion stability of the fine particles.

[0156] In addition, in order to improve the weather resistance of the near infrared absorbing particles, it is also preferable to coat the surface of the near infrared absorbing particles with a compound containing one or more elements selected from silicon, zirconium, titanium, and aluminum. These compounds are basically transparent, and adding them does not reduce the visible light transmittance of the near infrared absorbing particles, so the design of the fiber is not impaired.

[0157] Furthermore, in order to improve the chemical resistance of the near infrared absorbing particles, the surfaces of the near infrared absorbing particles may be coated with a thermoplastic resin such as a polyester resin, a polycarbonate resin, an acrylic resin, a polystyrene resin, a polyamide resin, a vinyl chloride resin, an olefin resin, a fluororesin, a polyvinyl acetate resin, a thermoplastic polyurethane resin, an acrylonitrile butadiene styrene resin, a polyvinyl acetal resin, an acrylonitrile-styrene copolymer resin, or an ethylene-vinyl acetate copolymer resin, or a thermosetting resin such as a phenol resin, an epoxy resin, a melamine resin, a urea resin, an unsaturated polyester resin, an alkyd resin, a thermosetting polyurethane resin, a polyimide resin, or a silicone resin.

[0158] The fibers containing near-infrared absorbing particles (composite tungsten oxide microparticles) on the surface and / or inside obtained in this manner are processed into long fibers or short fibers according to the application, and then spun into woven fabric or knitted fabric by a known method to form a fiber structure constituting the first surface layer. The above-mentioned fibers containing near-infrared absorbing particles on the surface and / or inside are processed by a known method to form a nonwoven fabric, which becomes a fiber structure constituting the first surface layer. Of course, a yarn (spun yarn) spun from fibers containing near-infrared absorbing particles on the surface and / or inside may be colorless or dyed. The above-mentioned fiber structures such as woven fabric, knitted fabric, and nonwoven fabric may also be partially or entirely dyed.

[0159] Examples of clothing using the resin film product obtained by the above-mentioned manufacturing method, in which the first surface layer and the second surface layer are composed of a film-like resin, and the textile product in which the first surface layer and the second surface layer are composed of a textile structure, include Western clothing, kimonos, bedding such as pajamas, underwear, winter clothing, the above-mentioned curtains, etc. EXAMPLES

[0160] Examples of the present invention will be specifically described below with reference to comparative examples.

[0161] [Example 1] 1. Production of composite tungsten oxide particles 0.216 kg of Cs2CO3 was dissolved in 0.330 kg of water, and the resulting solution was added to 1.000 kg of H2WO4 and thoroughly stirred, and then dried to obtain a dried product.

[0162] Next, the dried product was heated while supplying 5% H2 gas with N2 gas as a carrier, and was sintered at a temperature of 800 ° C for 1 hour. After that, a solid-phase synthesis method was carried out in which the product was further sintered at 800 ° C for 2 hours under a N2 gas atmosphere, thereby obtaining a coarse powder of the composite tungsten oxide according to Example 1.

[0163] 10% by mass of the obtained composite tungsten oxide coarse powder, 10% by mass of an acrylic polymer dispersant (an acrylic dispersant with an amine value of 48 mgKOH / g and a decomposition temperature of 250°C), and 80% by mass of toluene were weighed out. The weighed materials were placed in a paint shaker together with zirconia beads having a diameter of 0.3 mm, and a dispersion treatment was carried out using the paint shaker for 15 hours to obtain a composite tungsten oxide microparticle dispersion liquid according to Example 1. The average particle size of the composite tungsten oxide microparticles in the obtained dispersion liquid according to Example 1 was measured (measured by a transmission electron microscope) to be 25.1 nm.

[0164] 2. Manufacturing the first and second surface layers Next, the toluene was removed from the composite tungsten oxide microparticle dispersion liquid of Example 1 using a spray dryer, and a composite tungsten oxide microparticle dispersion powder of Example 1 was obtained.

[0165] The obtained composite tungsten oxide microparticle dispersion powder was added to polyethylene terephthalate resin pellets, which is a thermoplastic resin, and mixed uniformly in a blender. The mixture was then melt-kneaded and extruded in a twin-screw extruder, and the extruded strands were cut into pellets to obtain a master batch according to Example 1, which contains 40 mass% composite tungsten oxide microparticles, which are a near-infrared absorbing component.

[0166] Furthermore, the master batch according to Example 1 was melt spun and then drawn to produce the near infrared absorbing polyester multifilament yarn a according to Example 1.

[0167] Also, only the polyethylene terephthalate pellets were melt spun and then drawn to produce polyester multifilament yarn b.

[0168] Next, the near-infrared absorbing polyester multifilament yarn a according to Example 1 was cut to prepare near-infrared absorbing polyester staples, thereby producing near-infrared absorbing spun yarn a.

[0169] Moreover, the polyester multifilament yarn b was cut to prepare polyester staples to produce spun yarn b.

[0170] Then, the near-infrared absorbing spun yarn a and the spun yarn b were used to produce a first surface layer according to Example 1, which was made of a knit fabric (fabric structure).

[0171] The solar reflectance of the first surface layer according to Example 1, which is made of knit fabric (fabric structure), was adjusted to 8%.

[0172] Furthermore, a second surface layer according to Example 1, which is made of a knit fabric (fiber structure), was produced using a spun yarn not containing composite tungsten oxide microparticles (that is, the above spun yarn b).

[0173] 3. Manufacturing of near-infrared absorbing structures Next, a joint in which a first surface layer made of knitted fabric (a fiber structure containing composite tungsten oxide microparticles) and a second surface layer made of knitted fabric (a fiber structure not containing composite tungsten oxide microparticles) were partially joined was provided between the first surface layer and the second surface layer, and a plurality of hollow layers separated by the joint were provided on the first surface layer side of the second surface layer, thereby producing the near-infrared absorbing structure of Example 1 shown in FIG.

[0174] The above-mentioned joint was formed by sewing together a first surface layer made of knitted fabric (a fiber structure containing composite tungsten oxide microparticles) and a second surface layer made of knitted fabric (a fiber structure not containing composite tungsten oxide microparticles).

[0175] 4. Effect of suppressing temperature rise on the second surface layer side of near-infrared absorbing structure The temperature rise suppression effect on the second surface layer side of the obtained near infrared absorbing structure according to Example 1 was measured as follows.

[0176] In an environment of 20°C and 60% RH, a solar spectrum approximation lamp [solar simulator XL-03E50 manufactured by Ceric Co., Ltd.] was irradiated from a distance of 30 cm from the first surface layer (composed of a fiber structure containing composite tungsten oxide microparticles) of the near-infrared absorbing structure of Example 1, and the temperature on the second surface layer side was measured at regular intervals (0 seconds, 30 seconds, 60 seconds, 180 seconds, 360 seconds, 600 seconds) using a radiation thermometer [HT-11 manufactured by Minolta Co., Ltd.].

[0177] The results are shown in Table 1 below.

[0178] When measuring the temperature on the second surface layer side of the near-infrared absorbing structure, the near-infrared absorbing structure was supported horizontally by a support and placed so that the first surface layer (composed of a fiber structure containing composite tungsten oxide microparticles) was on the upper surface.

[0179] [Comparative Example 1] The sample according to Comparative Example 1 was made of only the first surface layer according to Example 1, which was made of knit fabric (a fiber structure containing composite tungsten oxide particles).

[0180] That is, the sample according to Comparative Example 1 was a structure in which there was no second surface layer and no hollow layer, which was made of knit fabric (a fiber structure not containing composite tungsten oxide microparticles).

[0181] Then, similarly to Example 1, the effect of suppressing a temperature rise on the back surface side of the sample according to Comparative Example 1 was evaluated.

[0182] The results are also shown in Table 1.

[0183] [Table 1]

[0184] [evaluation] (1) In Example 1, since the temperature on the second surface layer side of the near-infrared absorbing structure was measured, it was confirmed that the temperature rise was slight (25°C to 36°C) due to the action of the hollow layer existing between the first surface layer and the second surface layer.

[0185] (2) On the other hand, in the sample of Comparative Example 1 in which there is no second surface layer made of knitted fabric (a fiber structure not containing composite tungsten oxide microparticles) and no hollow layer, the back surface temperature of the first surface layer made of only knitted fabric (a fiber structure containing composite tungsten oxide microparticles) is measured, and it is confirmed that the temperature rises significantly (25°C to 47°C) compared to Example 1. [Industrial Applicability]

[0186] The near-infrared absorbing structure (textile product, etc.) of the present invention has a function of blocking heat rays from sunlight in summer and a function of receiving heat from sunlight in winter, and therefore has industrial applicability as a textile product that can be used in both summer and winter. [Explanation of symbols]

[0187] 1. Near-infrared absorbing structure 2. Near-infrared absorbing structure 3. Near-infrared absorbing structure 11 First surface layer 12 Second surface layer 13 Joint 14 Hollow layer 15 Long spacer 21 First surface layer 22 Second surface layer 23 Spacer 24 Hollow layer 30 Hollow part 31 First surface layer 32 Second surface layer 33 Joint

Claims

1. A first surface layer containing near infrared absorbing particles; A second surface layer that does not contain near infrared absorbing particles; a hollow layer provided on the first surface layer side of the second surface layer or on the opposite side of the second surface layer to the first surface layer, The near-infrared absorbing particle is a composite tungsten oxide fine particle represented by a general formula MxWyOz (wherein M is one or more elements selected from an alkali metal element, an alkaline earth metal element, a 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, and I; W is tungsten; O is oxygen; and 0.001≦x / y≦1, 2.0≦z / y≦3.0) and has a hexagonal crystal structure.

2. 2. The near-infrared absorbing structure according to claim 1, wherein a joint portion where the first surface layer and the second surface layer are partially joined is provided between the first surface layer and the second surface layer, and a plurality of hollow layers separated by the joint portion are provided on the first surface layer side of the second surface layer.

3. 2. The near-infrared absorbing structure according to claim 1, wherein a spacer is interposed between the first surface layer and the second surface layer, and a plurality of hollow layers separated by the spacer are provided on the first surface layer side of the second surface layer.

4. 2. The near-infrared absorbing structure according to claim 1, characterized in that a hollow portion is provided in a joining portion on one surface of a second surface layer, the other surface of which is overlapped with the first surface layer, and a plurality of hollow layers formed by the hollow portion are provided on the opposite side of the second surface layer to the first surface layer.

5. A resin film product comprising the near infrared absorbing structure according to claim 1, wherein the first surface layer and the second surface layer are made of a film-like resin.

6. A clothing article comprising the resin film product according to claim 5.

7. A textile product comprising the near-infrared absorbing structure according to claim 1, wherein the first surface layer and the second surface layer are made of a fiber structure.

8. A clothing article using the textile product according to claim 7.

9. A method for using the near infrared absorbing structure according to claim 1, A method for using a near-infrared absorbing structure, characterized in that in summer, the first surface layer side containing near-infrared absorbing particles is faced toward the side where sunlight is irradiated, thereby using the structure for blocking heat rays of sunlight, and in winter, the second surface layer side not containing near-infrared absorbing particles is faced toward the side where sunlight is irradiated, thereby using the structure for protection against the cold and for keeping warm.

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