JP2017002708A - Slat and solar control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar control device that makes a shielding effect suitable in summer and winter season and can prevent influence of reflection to the ground direction by recursive reflection to an incidence direction, and furthermore, is superior in lighting directionality.SOLUTION: A solar control device has multiple slats 1. Each of the multiple slats 1 has a first main surface having a flat surface and a second main surface at the side opposite to the first main surface. Each of the multiple slats 1 has a first reflection structure 2 in the first main surface side, and has a second reflection structure 3 in the second main surface side. The first reflection structure 2 has recursive reflection characteristics for retroreflecting near-infrared light incident from the first main surface side at an incidence angle of a predetermined range. The second reflection structure 3 has specular reflection characteristics for specularly reflecting the near-infrared light incident from the second main surface side. The multiple slats 1 each are arranged with the first main surface as the same side in the direction intersecting with the longitudinal direction with the longitudinal direction parallel to each other.SELECTED DRAWING: Figure 7A

Description

  The present invention relates to a solar radiation adjusting device and a slat used in the solar radiation adjusting device.

  In recent years, cases in which a layer that reflects part of sunlight is provided on architectural glass such as high-rise buildings and residences are increasing. This is one of the energy-saving measures for the purpose of preventing global warming, and the purpose is to reduce the cooling load in summer when light energy poured from the sun enters the window indoors and the indoor temperature rises. It is said.

  The light energy poured from sunlight occupies a large proportion of the visible region having a wavelength of 380 nm to 780 nm and the near infrared region having a wavelength of 780 nm to 2,100 nm. Among these, the transmittance of the window with respect to light energy in the near-infrared region with a wavelength of 780 nm to 2,100 nm is irrelevant to human visibility, and thus affects the performance as a window having high transparency and high heat shielding properties. It becomes an important factor.

As a method of shielding near infrared rays (heat rays) while maintaining transparency in the visible region, there is a method of providing a window glass with a layer having a high reflectance in the near infrared region. As this method, many techniques using an optical multilayer film, a metal-containing film, a transparent conductive film, and the like as a reflective layer have already been proposed (for example, see Patent Document 1).
However, in these proposed technologies, the heat ray shielding effect obtained by reflection to the outdoors is a year-round effect, and is also effective in winter. Therefore, depending on the shielding amount, there is a problem that the heating load in winter increases.
Moreover, since such a reflection layer is provided in the window glass on a plane, it can only reflect regularly the incident sunlight. Therefore, the light that is incident from above and reflected downward reaches another outdoor building or the ground surface, is absorbed, changes to heat, and raises the ambient temperature. As a result, there are problems such as a local temperature rise in the vicinity of a building where such a reflective layer is applied to the entire window, and heat islands increasing in urban areas, and deterioration of the thermal environment of pedestrian spaces. .

Currently, as a solution to these problems, there is a method of optimizing the shielding effect between seasons by using a blind composed of a plurality of slats provided with an infrared reflection layer and appropriately adjusting the angle of the slats. It has been proposed (see, for example, Patent Document 2).
In addition, in the angle-selective transmissive reflector made of a filter or a film having an angle-selective light-transmitting means whose transmittance varies depending on the incident angle of the light beam, the angle-selective light-transmitting means includes a retroreflective material in its configuration An angle-selective transmissive reflecting material having the following has been proposed (for example, see Patent Document 3).
In addition, a method has been proposed in which sunlight is retroreflected in the incident direction by using a louver device including a plurality of vertical plates and a plurality of horizontal plates and reflecting twice between the horizontal plate and the vertical plate (for example, a patent). Reference 4).
In addition, using a retroreflector including an optical layer having a smooth incident surface, a concavo-convex shape formed in the optical layer, and a wavelength selective reflection film formed on the concavo-convex shape, a part of sunlight is A method has been proposed in which the heat island is prevented from increasing due to reflection toward the ground surface while having high heat shielding properties by retroreflecting the sky (see, for example, Patent Document 5).

  In addition, various techniques have been proposed for blinds and louver devices (see, for example, Patent Documents 6 to 8).

International Publication No. 05/087680 Pamphlet Japanese Utility Model Publication No. 06-087597 JP 2004-341272 A JP 2011-24696 A JP 2010-160467 A Japanese Patent Application Laid-Open No. Sho 61-22503 Japanese Patent Laid-Open No. 5-295967 JP 2008-40025 A

However, in the blind and louver device, in order to optimize the shielding effect, it is necessary to perform operations such as adjusting the angle of the slat according to the incident direction throughout time and season, and there is a problem that it takes time and effort for operation. Further, since a mechanism for adjustment is required, there is a problem of high cost.
Although the retroreflector can prevent the influence of reflection in the surface direction, there is a problem that the heating load in winter increases because of the shielding effect in winter.
Furthermore, in a solar radiation adjusting device such as a blind or a louver device, it is desirable that the solar radiation is delivered upward when daylighting is performed indoors. In other words, it is desirable to have excellent lighting directionality.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention can optimize the shielding effect in summer and winter without performing the adjustment operation of the slat according to the season, and prevents the influence of reflection in the ground direction by retroreflection in the incident direction. Furthermore, it aims at providing the solar radiation adjustment apparatus which is excellent also in the directionality of lighting, and the slat used for the said solar radiation adjustment apparatus.

Means for solving the problems are as follows. That is,
<1> Having a plurality of slats,
Each of the plurality of slats has a first main surface having a flat surface, and a second main surface opposite to the first main surface,
Each of the plurality of slats has a first reflective structure on the first main surface side and a second reflective structure on the second main surface side,
The first reflective structure has a retroreflective characteristic for retroreflecting near infrared rays incident from the first main surface side at an incident angle within a predetermined range;
The second reflection structure has specular reflection characteristics for specularly reflecting near infrared rays incident from the second main surface side,
The plurality of slats are arranged with the first main surface on the same side in a direction crossing the longitudinal direction with the longitudinal direction parallel.
This is a solar radiation adjusting device.
<2> The second optical element in which the first reflective structure has a convex shape, a reflective layer disposed on the convex shape, and a concave shape that makes up the convex shape. It is a solar radiation adjusting device as described in said <1> which has a layer in this order.
<3> The solar radiation adjusting device according to <2>, wherein the convex shape of the first optical layer is a convex shape formed by one of a one-dimensional array and a two-dimensional array of a large number of structures.
<4> The solar radiation adjusting device according to <3>, wherein the structure has a prism shape, a lenticular shape, a hemispherical shape, or a corner cube shape.
<5> The solar radiation adjusting device according to any one of <2> to <4>, wherein the reflective layer includes at least one of a metal thin film, a metal oxide thin film, and a metal nitride thin film.
<6> The solar radiation adjusting device according to any one of <1> to <5>, wherein the second reflective structure has a reflective layer.
<7> The solar radiation adjusting device according to <6>, wherein the reflective layer in the second reflective structure includes a metal thin film.
<8> The solar radiation adjusting device according to <7>, wherein the metal is one of Ag and an Ag alloy.
<9> The solar radiation adjusting device according to any one of <1> to <8>, wherein a slat angle of each of the plurality of slats is 20 ° to 40 °.
<10> The solar radiation according to any one of <1> to <9>, wherein the first reflective structure has visible light permeability, and the second reflective structure has visible light permeability. It is an adjustment device.
<11> A slat used in a solar radiation adjusting device,
A first main surface having a flat surface and a second main surface on the opposite side of the first main surface;
Having a first reflective structure on the first main surface side and having a second reflective structure on the second main surface side;
The first reflective structure has a retroreflective characteristic for retroreflecting near infrared rays incident from the first main surface side at an incident angle within a predetermined range;
The second reflective structure has specular reflection characteristics for specularly reflecting near infrared rays incident from the second main surface side.
It is a slat characterized by this.

  According to the present invention, the conventional problems can be solved and the object can be achieved, and the shielding effect in summer and winter can be optimized without adjusting the slat according to the season. In addition, the influence of reflection in the ground surface direction can be prevented by retroreflection in the incident direction, and further, the solar radiation adjusting device excellent in the lighting directionality and the slat used in the solar radiation adjusting device can be provided.

FIG. 1 is a graph showing the solar altitude in the middle and south of Tokyo. FIG. 2 is a graph showing an example of the interface reflectance between the air and the optical layer. FIG. 3A is a schematic front view of an example of the solar radiation adjusting device of the present invention. 3B is a cross-sectional view taken along the line AA in FIG. 3A. FIG. 3C is a diagram for explaining a slat angle (θ) and a slat interval (G). FIG. 4A is a schematic front view of another example of the solar radiation adjusting device of the present invention. 4B is a cross-sectional view taken along line BB in FIG. 4A. FIG. 5 is a schematic front view of another example of the solar radiation adjusting device of the present invention. FIG. 6 is a schematic cross-sectional view of an example of a slat. FIG. 7A is a schematic diagram illustrating a state of retroreflection outdoors and a state of light passing indoors at a sun altitude of 75 ° during summer in the south and middle according to an embodiment of the present invention. FIG. 7B is a schematic diagram illustrating a state of retroreflection to the outdoors and a state of light passing indoors at a solar altitude of 55 ° in the south and middle of spring and autumn according to an embodiment of the present invention. FIG. 7C is a schematic diagram illustrating a state of retroreflection outdoors and a state of light passing indoors at a solar altitude of 35 ° during the winter in the south and middle according to an embodiment of the present invention. FIG. 7D is a schematic diagram showing a state of light passing indoors at a solar altitude of 15 ° below the slat angle according to an embodiment of the present invention. FIG. 8 is a schematic cross-sectional view of another example of the slat. FIG. 9A is a schematic diagram illustrating a state of retroreflection outdoors and a state of light passing indoors at a sun altitude of 75 ° during summer in the south and middle according to an embodiment of the present invention. FIG. 9B is a schematic diagram showing a state of retroreflection outdoors and a state of light passing indoors at a solar altitude of 55 ° in the middle of spring and autumn according to an embodiment of the present invention. . FIG. 9C is a schematic diagram showing a state of retroreflection outdoors and a state of light passing indoors at a sun altitude of 35 ° during the winter season in the south and middle according to an embodiment of the present invention. FIG. 9D is a schematic diagram showing a state of light passing indoors at a solar altitude of 15 ° below the slat angle according to an embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of another example of the slat. FIG. 11A is a schematic diagram showing a state of retroreflection outdoors and a state of light passing indoors at a sun altitude of 75 ° during summer in the south and middle according to an embodiment of the present invention. FIG. 11B is a schematic diagram showing a state of retroreflection to the outdoors and a state of light passing indoors at a solar altitude of 55 ° during the spring / autumn south and middle times according to an embodiment of the present invention. . FIG. 11C is a schematic diagram showing a state of retroreflection outdoors and a state of light passing indoors at a solar altitude of 35 ° during the winter in the south and middle according to an embodiment of the present invention. FIG. 11D is a schematic diagram illustrating a state of light passing indoors at a solar altitude of 15 ° below a slat angle according to an embodiment of the present invention. FIG. 12 is a diagram for explaining a preferable range of the slat angle. FIG. 13A is a perspective view illustrating a shape example of a structure formed in the first optical layer. FIG. 13B is a perspective view showing an example of the shape of the structure formed in the first optical layer. FIG. 13C is a perspective view illustrating a shape example of a structure formed in the first optical layer. FIG. 13D is a plan view illustrating a shape example of the structure formed in the first optical layer. FIG. 13E is a cross-sectional view of the first optical layer shown in FIG. 13D taken along line BB. FIG. 14 is a schematic cross-sectional view of another example of the slat. FIG. 15 is a schematic cross-sectional view of another example of a slat. FIG. 16 is a schematic cross-sectional view of another example of a slat. FIG. 17 is a schematic cross-sectional view of another example of a slat. FIG. 18A is a diagram for explaining the incident angle when evaluating the shielding property and the transmittance of the reflecting structure body and slats against solar radiation. FIG. 18B is a diagram for explaining an incident angle when evaluating the shielding property and the transmittance with respect to the solar radiation of the solar radiation adjusting device. FIG. 19 is a cross-sectional view of the reflective structure used in Experimental Example 1. 20 is a cross-sectional view showing the shape of the molding surface of the aluminum mold of Experimental Example 1. FIG. FIG. 21A is a simulation result of solar transmittance in the case of the reflective layer (A1). FIG. 21B is a simulation result of solar transmittance in the case of the reflective layer (B1). FIG. 21C is a simulation result of solar reflectance in the case of the reflective layer (A1). FIG. 21D shows an actual measurement result and a simulation (Sim) result of solar reflectance in the case of the reflective layer (B1). FIG. 21E shows the measurement result of the reflection spectrum (60 ° incidence) in the case of the reflective layer (B2). FIG. 22 is a cross-sectional view of the reflective structure used in Experimental Example 2. FIG. 23A is a simulation result of solar transmittance in the case of the reflective layer (A2). FIG. 23B is a simulation result of solar transmittance in the case of the reflective layer (B2). FIG. 23C is a simulation result of solar reflectance in the case of the reflective layer (A2). FIG. 23D is a simulation result of solar reflectance in the case of the reflective layer (B2). FIG. 23E is a simulation result of the reflection spectrum (60 ° incidence) in the case of the reflective layer (B2). FIG. 24 is a cross-sectional view of the slat used in Experimental Example 3. FIG. 25 is a cross-sectional view of the solar radiation adjusting device used in Experimental Example 3. FIG. 26A is a simulation result of solar radiation transmittance. FIG. 26B is a simulation result of solar reflectance. FIG. 26C is a simulation result of solar reflectance (retroreflection). FIG. 27A is a simulation result of visible light transmittance. FIG. 27B is a simulation result of visible light reflectance. FIG. 27C is a simulation result of visible light reflectance (retroreflection). FIG. 28A is a simulation result of near-infrared transmittance. FIG. 28B is a simulation result of near-infrared reflectance. FIG. 28C is a simulation result of near-infrared reflectance (retroreflection). FIG. 29A is a simulation result of solar radiation transmittance. FIG. 29B is a simulation result of visible light transmittance. FIG. 29C is a simulation result of near-infrared transmittance. FIG. 30 is a diagram for explaining the transmission angle. FIG. 31 is a schematic diagram showing the state of reflection and transmission of the solar radiation adjusting apparatus A. FIG. 32 is a schematic diagram showing the state of reflection and transmission of the solar radiation adjusting device 3.

(Solar radiation adjustment device)
The solar radiation adjusting device of the present invention includes at least a plurality of slats, and further includes other members as necessary.
In the solar radiation adjusting device, the plurality of slats are arranged with the first main surface on the same side in a direction crossing the longitudinal direction with the longitudinal direction parallel.

Each of the plurality of slats has a first main surface having a flat surface, and further has a second main surface opposite to the first main surface.
Each of the plurality of slats has a first reflective structure on the first main surface side and a second reflective structure on the second main surface side.
The first reflective structure has retroreflective properties that retroreflect near-infrared rays incident from the first main surface side at an incident angle within a predetermined range.
The second reflecting structure has specular reflection characteristics for specularly reflecting near infrared rays incident from the second main surface side.

  Here, near infrared rays generally mean light with a wavelength of 780 nm to 2,100 nm. Visible light generally means light having a wavelength of 380 nm to 780 nm.

  Hereinafter, the slat of the present invention will be described through the description of the solar radiation adjusting device of the present invention.

  The present inventor can optimize the shielding effect in summer and winter without adjusting the slat according to the season, and prevent the influence of reflection in the ground direction by retroreflection in the incident direction. In order to provide a solar radiation adjusting device that can be used and has excellent lighting directionality, the following examination was performed.

The present inventor has focused on the change in annual solar altitude.
FIG. 1 is an example of the solar altitude as an index of the incident angle to the solar radiation adjusting device, and is a graph showing the solar altitude (south / middle altitude) at the time of the south and middle of each month on the 21st of Tokyo. In Tokyo, the solar altitude changes annually, and the altitude is almost the same in the south and middle altitudes in spring and summer, and in autumn and winter.

The inventor paid attention to the relationship between the incident angle and the interface reflectance.
FIG. 2 is a graph showing the interface reflectance (%) of solar radiation at the interface between the air layer and an example of the optical layer (refractive index: 1.6) constituting the slat. The interface reflectivity changes depending on the incident angle. In addition, regular reflection is assumed for interface reflection here.
The incident angle is determined by the relative angle between the south and middle altitudes and the slat. And interface reflection arises in the ratio on this graph.

  Therefore, the present inventor summarized the relationship among the monthly south-central altitude, the incident angle on the slats, and the interface reflectance. It is shown in Table 1. In this calculation, the slat angle (θ) of the slat is 30 °. In spring and summer, the interface reflectance is small, and the interface reflectance increases from autumn to winter, exceeding 90% at the maximum.

The present inventor has found the following solar radiation adjusting device based on the result of the above examination.
The solar radiation adjusting device of the present invention has a plurality of slats.
Each of the plurality of slats has a first main surface having a flat surface, and further has a second main surface opposite to the first main surface.
Each of the plurality of slats has a first reflective structure on the first main surface side and a second reflective structure on the second main surface side.
The first reflective structure has retroreflective properties that retroreflect near-infrared rays incident from the first main surface side at an incident angle within a predetermined range.
The second reflecting structure has specular reflection characteristics for specularly reflecting near infrared rays incident from the second main surface side.
The plurality of slats are arranged with the first main surface on the same side in a direction crossing the longitudinal direction with the longitudinal direction parallel.
The solar radiation control device optimizes the shielding effect in summer and winter without adjusting the slat according to the season, and prevents the influence of reflection in the ground direction by retroreflection in the incident direction. Furthermore, it is excellent also in the direction of daylighting.

3A and 3B are schematic views of an example of the solar radiation adjusting apparatus of the present invention.
3A is a front view of the solar radiation adjusting device, and FIG. 3B is a cross-sectional view taken along line AA of FIG. 3A. 3A and 3B includes a frame body 10 and a plurality of slats 1. The plurality of slats 1 are arranged in a direction crossing the longitudinal direction with the longitudinal direction being parallel. The plurality of slats 1 have a predetermined interval. The plurality of slats 1 are supported by the frame body 10 and have a slat angle (θ) shown in FIG. 3C. Here, the slat angle (θ) refers to an angle formed by the horizontal plane and the surface of the slat 1. Usually, in the solar radiation adjusting device, since the arrangement direction (L) of the plurality of slats is in the vertical direction with respect to the horizontal plane, the slat angle (θ) can also be expressed by the following formula: 90 ° −δ. Here, the angle (δ) is an angle formed by the arrangement direction (L) and the surface of the slat.
In addition, the solar radiation adjustment apparatus of this embodiment is installed so that light may enter from the drawing left side in FIG. 3B and FIG. 3C.

  Further, in the solar radiation adjusting device of the present invention, a plurality of slats may be sandwiched between two pieces of glass. By doing so, the window or sash which has a solar radiation adjustment function and does not let wind flow through is obtained. Moreover, you may install the solar radiation adjustment apparatus of this embodiment in the outdoor side or indoor side of the window glass in a window.

4A and 4B are schematic views of another example of the solar radiation adjusting device of the present invention.
4A is a front view of the solar radiation adjusting device, and FIG. 4B is a cross-sectional view taken along line BB of FIG. 4A. The solar radiation adjusting device in FIGS. 4A and 4B has two rod bodies 11 and a plurality of slats 1. The plurality of slats 1 are arranged in a direction crossing the longitudinal direction with the longitudinal direction being parallel. The plurality of slats 1 have a predetermined interval. The two rod bodies 11 penetrate the plurality of slats 1 and support the plurality of slats 1.

FIG. 5 is a schematic diagram of another example of the solar radiation adjusting device of the present invention. This solar radiation adjusting device is a so-called blind. The solar radiation adjusting device of FIG. 5 includes a slat 1, a head box 21, a ladder cord 22, an operation rod 23, an operation unit 24, an elevating cord 25, a knob 26, and a bottom rail 27.
Ladder cords 22 are suspended from a plurality of longitudinal positions (three in the figure) of the head box 21 attached to a window frame or the like (not shown), and a large number of slats 1 are supported in an aligned state by the ladder cords 22. . A bottom rail 27 is disposed at the lower end of the row of slats 1, and one end of the lifting / lowering cord 25 is connected to a plurality of longitudinal positions (two in the figure) of the bottom rail 27. The other end of each lifting / lowering cord 25 passes through the row of slats 1 and is introduced into the head box 21, passes through a stopper (not shown), and is led out from one end of the head box 21.
An operation rod 23 is suspended from one end of the head box 21. The operation rod 23 is connected to a rotation transmission mechanism in the head box 21, and the rotation operation of the operation rod 23 is converted into a tilting operation of the ladder cord 22 through the rotation transmission mechanism. The inclination of the slat 1 can be varied. The operation rod 23 is hollow, and a plurality of lifting cords 25 led out from one end of the head box 21 are inserted through the operation rod 23 and led out from the lower end of the operation rod 23.
An operation unit 24 is provided at the lower end of the operation bar 23, and the operation bar 23 and the operation unit 24 constitute an operation device. The plurality of lifting / lowering cords 25 led out from the operating rod 23 are further passed through the operating portion 24 and led out from the lower end of the operating portion 24, and the end portions are collectively connected to the knob 26. By pulling the lifting / lowering cord 25, the bottom rail 27 is lifted and the blinds are stored.

  FIG. 6 is a schematic cross-sectional view of an example of a slat. The slat 1 has a first reflective structure 2 on the first main surface 1A side and a second reflective structure 3 on the second main surface 1B side. The surface of the first reflecting structure 2 on the first main surface 1A side is flat.

Below, an effect at the time of using an example of the solar radiation adjusting device of this invention and its solar radiation adjusting device is demonstrated using FIG. 7A-FIG. 7D.
FIG. 7A to FIG. 7C show the cases where incident light with incident angles of 75 °, 55 °, and 35 °, corresponding to spring / summer, intermediate period, and autumn / winter, is incident at a slat angle (θ) of 30 °. The state of the retroreflection to the outdoors and the state of light passing indoors including the interface reflection are shown. In FIG. 7A to FIG. 7D, the type of light is distinguished by the shape of the tip of the arrow and the line type of the bar portion. 7A to 7D, the slat having the configuration shown in FIG. 6 is used. The incident angle corresponds to the solar altitude.

At 75 ° (FIG. 7A) and 55 ° (FIG. 7B) where the solar altitude from spring to summer is relatively high, most of the incident light has a retroreflective structure that retroreflects near infrared rays. 2 is incident on the surface. Since the incident angle is smaller as the solar altitude is higher, many near infrared rays are retroreflected to the outdoor side by the retroreflection characteristics of the first reflecting structure 2. On the other hand, the near-infrared ray that undergoes interface reflection (regular reflection) on the surface of the first reflecting structure 2 (the surface on the first main surface side) is slight. Near-infrared light reflected by the interface travels indoors. At that time, the near-infrared ray reflected at the interface may be reflected at the surface of the opposing second reflecting structure 3 (surface on the second main surface side) in the adjacent slat (FIG. 7A).
Here, the incident angle means an angle formed by a perpendicular (line perpendicular to the surface) to the surface of the first reflective structure and incident light.

On the other hand, the lower the solar altitude (the larger the incident angle), the larger the regular reflection, and the more near infrared rays travel indoors.
At the sun altitude of 35 ° in autumn and winter, the interface reflection on the first main surface becomes very large, and most of the near infrared rays, including the near infrared rays that pass through the slats without entering the slats, travel indoors. (FIG. 7C).
Further, as shown in FIG. 7D, when light is incident on the solar radiation adjusting device at an angle lower than the slat angle (solar altitude of 15 °), the light is incident on the second main surface on the lower surface of the slat, and the second Most of the near-infrared light travels indoors by near-infrared light reflected at the surface of the reflective structure 3 and near-infrared light that passes through the slats.

As described above with reference to FIGS. 7A to 7D, in the solar radiation adjusting device of the present invention, even in the case where the slat angle is kept constant without adjusting the slat angle, it is difficult for near infrared rays to enter indoors in the summer. And in the winter, near infrared rays can be easily put indoors. For this reason, the shielding effect in summer and winter can be optimized. Furthermore, the influence of reflection in the ground surface direction can be prevented by retroreflection in the incident direction.
Further, as can be confirmed from Experimental Example 4 to be described later, in daylighting indoors, there is a tendency to deliver visible light above the horizontal and brighten the ceiling direction. That is, it also has excellent lighting directionality.

  Then, in the solar radiation adjusting apparatus of this invention, about the aspect in case the 1st reflective structure of a slat and a 2nd reflective structure have visible-light transmittance, FIG.8 and FIG.9A-FIG.9D are used. explain. In FIG. 9A to FIG. 9D, the type of light is distinguished by the shape of the tip of the arrow and the type of line of the bar portion.

FIG. 8 is a schematic cross-sectional view of an example of a slat. The slat 1 has a second reflective structure 3 and a first reflective structure 2.
The first reflective structure 2 includes a first optical layer 2A having a convex shape, a reflective layer 2B disposed on the convex shape, and a second optical layer having a concave shape to make up the convex shape. 2C in this order. The first optical layer 2A and the second optical layer 2C transmit at least visible light. The reflective layer 2B has a so-called near-infrared selective reflection characteristic that has a reflection characteristic with respect to near infrared rays but has a transmission characteristic with respect to visible light. The first optical layer 2A has a flat surface. This surface is also the first main surface of the slat 1.
The second reflective structure 3 has a reflective layer, and the reflective layer has a so-called near-infrared selective reflection characteristic that has a reflection characteristic with respect to near infrared rays but has a transmission characteristic with respect to visible light.

  FIGS. 9A to 9C show the case where light having incident angles of 75 °, 55 °, and 35 °, which corresponds to spring / summer, intermediate period, and autumn / winter, respectively, at a slat angle (θ) of 30 °. The state of the retroreflection to the outdoors and the state of light passing indoors including the interface reflection are shown. 9A to 9D, the slat 1 has the structure shown in FIG. The incident angle corresponds to the solar altitude.

  At 75 ° (FIG. 9A) and 55 ° (FIG. 9B) where the solar altitude from spring to summer is relatively high, most of the incident light has a retroreflective structure that retroreflects near infrared rays. 2 is incident on the surface. Since the incident angle is smaller as the solar altitude is higher, the light is less likely to be reflected at the surface (regular reflection), and enters the first reflecting structure 2. Of the light that has entered the first reflecting structure 2, near infrared light is reflected by the reflecting layer 2B. At this time, due to the structure of the reflective layer 2B, the near-infrared reflection becomes retroreflection. On the other hand, of the light that has entered the first reflective structure 2, visible light passes through the first reflective structure 2 and the second reflective structure 3. As a result, the first reflecting structure 2 retroreflects near infrared light that has entered the first reflecting structure 2 and returns it to the outdoor side, and the first reflecting structure 2 and the second reflecting structure 3. However, the visible light that has entered the first reflective structure 2 is transmitted and travels indoors. On the other hand, the amount of light that undergoes interface reflection (regular reflection) on the surface of the first reflective structure 2 (the surface on the first main surface side) is small. At that time, the interface-reflected light may be interface-reflected on the surface of the opposing second reflecting structure 3 (surface on the second main surface side) in the adjacent slat (FIG. 9A).

On the other hand, the lower the solar altitude (the larger the incident angle), the greater the regular reflection, and much of the light travels indoors regardless of visible light and near infrared rays.
At the sun altitude of 35 ° in autumn and winter, the interface reflection (regular reflection) on the first main surface becomes very large, and most of the light including the light that passes through the slats without entering the slats is indoors. (FIG. 9C).
Further, as shown in FIG. 9D, when light is incident on the solar radiation adjusting device at an angle smaller than the slat angle (solar altitude of 15 °), the light is incident on the second main surface on the lower side surface of the slat, and the second Most of the light travels indoors, including the light reflected at the surface of the reflective structure 3 and the light passing through the slats, as in the autumn and winter seasons.

  As described above with reference to FIGS. 9A to 9D, when the near-infrared selective reflection characteristic is applied in the solar radiation adjusting device of the present invention, most of the visible light travels indoors throughout the year. Therefore, the effect of the present invention described above [(1) The shielding effect in summer and winter can be optimized without performing the adjustment operation of the slat according to the season. (2) The influence of reflection in the ground surface direction can be prevented by retroreflection in the incident direction. In addition, it is possible to ensure daylighting. Here, as can be confirmed from Experimental Example 4 to be described later, in indoor lighting, visible light tends to be delivered upward from the horizontal, and the ceiling direction tends to be brightened.

  Subsequently, in the solar radiation adjusting device of the present invention, for visible light, the first reflective structure has a transmission characteristic, and the second reflective structure has a reflection characteristic, FIG. And it demonstrates using FIG. 11A-FIG. 11D. In FIG. 11A to FIG. 11D, the type of light is distinguished by the shape of the tip of the arrow and the type of line of the bar portion.

FIG. 10 is a schematic cross-sectional view of an example of a slat. The slat 1 has a second reflective structure 3 and a first reflective structure 2.
The first reflective structure 2 includes a first optical layer 2A having a convex shape, a reflective layer 2B disposed on the convex shape, and a second optical layer having a concave shape to make up the convex shape. 2C in this order. The first optical layer 2A and the second optical layer 2C transmit at least visible light. The reflective layer 2B has a so-called near-infrared selective reflection characteristic that has a reflection characteristic with respect to near infrared rays but has a transmission characteristic with respect to visible light. The first optical layer 2A has a flat surface. This surface is also the first main surface of the slat 1.
The second reflective structure 3 has a reflective layer, and the reflective layer has a reflective characteristic with respect to visible light and near infrared rays.

  FIG. 11A to FIG. 11C show the cases where incident light with incident angles of 75 °, 55 °, and 35 °, corresponding to spring / summer, intermediate period, and autumn / winter, is incident at a slat angle (θ) of 30 °. The state of the retroreflection to the outdoors and the state of light passing indoors including the interface reflection are shown. 11A to 11D, the slat 1 has the structure shown in FIG. The incident angle corresponds to the solar altitude.

  The first reflective structure having retroreflective properties in which most of the incident light retroreflects near-infrared light at 75 ° (FIG. 11A) and 55 ° (FIG. 11B) at relatively high solar altitudes from spring to summer. 2 is incident on the surface. Since the incident angle is smaller as the solar altitude is higher, the light is less likely to be reflected at the surface (regular reflection), and enters the first reflecting structure 2. Of the light that has entered the first reflecting structure 2, near infrared light is reflected by the reflecting layer 2B. At this time, due to the structure of the reflective layer 2B, the near-infrared reflection becomes retroreflection. On the other hand, of the light that has entered the first reflective structure 2, visible light passes through the first reflective structure 2, but is regularly reflected by the reflective layer 3 </ b> A of the second reflective structure 3. And the specularly reflected visible light passes to the indoor side. As a result, the first reflective structure 2 retroreflects near infrared light that has entered the first reflective structure 2 and returns it to the outdoor side, and the second reflective structure 3 is the first reflective structure. 2. Visible light that has entered the interior 2 is regularly reflected and advanced indoors. On the other hand, the amount of light that undergoes interface reflection (regular reflection) on the surface of the first reflective structure 2 (the surface on the first main surface side) is small. At that time, the interface-reflected light may be interface-reflected on the surface of the opposing second reflecting structure 3 (surface on the second main surface side) in the adjacent slat (FIG. 11A).

On the other hand, the lower the solar altitude (the larger the incident angle), the greater the regular reflection, and much of the light travels indoors regardless of visible light and near infrared rays.
At the sun altitude of 35 ° in autumn and winter, the interface reflection (regular reflection) on the first main surface becomes very large, and most of the light including the light that passes through the slats without entering the slats is indoors. (FIG. 11C).
In addition, as shown in FIG. 11D, when light is incident on the solar radiation adjusting device at an angle lower than the slat angle (solar altitude of 15 °), the light is incident on the second main surface on the lower surface of the slat, and the second Most of the light, including the light passing through the slats, travels indoors as in the autumn / winter season because most of the light is regularly reflected on the surface of the reflective structure 3.

  As described above with reference to FIGS. 11A to 11D, when the near-infrared selective reflection characteristic is applied to the first reflecting structure in the solar radiation adjusting device of the present invention, most of the visible light travels indoors throughout the year. To do. Therefore, the effect of the present invention described above [(1) The shielding effect in summer and winter can be optimized without performing the adjustment operation of the slat according to the season. (2) The influence of reflection in the ground surface direction can be prevented by retroreflection in the incident direction. In addition, it is possible to ensure daylighting. Furthermore, when visible light transmission characteristics are applied to the first reflective structure, visible light is likely to reach the back of the room due to regular reflection of visible light by the second reflective structure. Compared to the case of 8 slats. Here, as can be confirmed from Experimental Example 4 to be described later, in indoor lighting, visible light tends to be delivered upward from the horizontal, and the ceiling direction tends to be brightened. That is, it also has excellent lighting directionality.

<Slats>
Each of the plurality of slats has a first main surface having a flat surface, and further has a second main surface opposite to the first main surface.
Each of the plurality of slats has a first reflective structure on the first main surface side and a second reflective structure on the second main surface side.
Each of the plurality of slats may include other members in addition to the first reflective structure and the second reflective structure.

When the first main surface has a flat surface, the slat can regularly reflect light on the first main surface when the incident angle is large.
Here, the flatness may be flatness that allows regular reflection of light when the incident angle is large. In the regular reflection here, the incident angle and the reflection angle do not need to be exactly the same, and may be different by about 5 °, for example.

  The slat generally means a rectangular plate installed in the solar radiation adjusting device.

  In the solar radiation adjusting device, the plurality of slats are arranged such that the second reflecting structure is on the lower side, the first reflecting structure is on the upper side, and the second main surface faces the outdoors. It is preferable.

The slat angle (θ) of the plurality of slats may be invariable or variable in the solar radiation adjusting device. When the slat angle is variable, it is preferable that the slat angles of a plurality of slats can be changed at a time.
The solar radiation adjusting device of the present invention does not need to adjust the slat angle (θ) according to the season, but the south-south altitude of the sun differs slightly depending on the installation area, so that the slat angle (θ) is variable. The optimum slat angle (θ) can be set according to the installation area.

There is no restriction | limiting in particular as said slat angle ((theta)), Although it can select suitably according to the objective, More than 0 degree and 70 degrees or less are preferable, 20 degrees-40 degrees are more preferable, 20 degrees-35 degrees are preferable. Particularly preferred.
When the incident angle exceeds 70 °, the interface reflection (regular reflection) tends to increase (for example, exceed 20). On the other hand, the solar altitude can reach 90 ° at low latitudes. Therefore, the slat angle (θ) is preferably 70 ° or less based on the incident angle and the solar altitude (see FIG. 12).
It should be noted that the slat angle is particularly preferably 25 ° to 35 ° when used in an area where the south-central altitude in summer is about 80 ° (for example, Tokyo). Furthermore, in consideration of a region where the south-south altitude in summer is about 90 ° to about 70 °, 20 ° to 40 ° is preferable.

  With regard to the slat angle, it is preferable that the incident angle on the slat is about 70 ° at the south and middle altitudes at the time of spring and autumn. That is, it is preferable to set an incident angle around 70 ° at which the interface reflection is increased at this time so that the outdoor reflection and the indoor transmission are switched between the equinox and the equinox. However, at low latitudes, the solar altitude may exceed 90 °. In view of these, a slat angle of 70 ° is preferable in the intermediate period when it is desired to switch in and out of solar radiation. For example, by setting the slat angle to 30 °, in the case of Tokyo, the incident angle to the slat is 65 ° at the south-central altitude at the time of spring equinox and autumn equinox.

  There is no restriction | limiting in particular as the space | interval between adjacent slats in these slats, According to the objective, it can select suitably. For example, the interval between the slats may be appropriately selected in consideration of the relationship with the length of the slats in the short direction. Here, the said space | interval is the space | interval (G) of the sequence direction (L) between the adjacent slats 1, as shown to FIG. 3C.

The slat generally has a rectangular plate shape.
As the size of the slat, when the shape of the main surface of the slat is a rectangle, the length in the longitudinal direction is not particularly limited and can be appropriately selected according to the purpose. There is no restriction | limiting in particular as length, According to the objective, it can select suitably. For example, the length in the short direction may be appropriately selected in consideration of the relationship with the slat interval.

  There is no restriction | limiting in particular as the number of the slats in the said solar radiation adjustment apparatus, According to the objective, it can select suitably.

<< First Reflective Structure >>
The slat has a first reflecting structure on the first main surface side.
The first reflective structure has retroreflective properties that retroreflect near-infrared rays incident from the first main surface side at an incident angle within a predetermined range. The first reflective structure may or may not retroreflect visible light incident from the first main surface side at an incident angle within a predetermined range.
In the slat, a surface on the first main surface side of the first reflective structure may constitute the first main surface.

  There is no restriction | limiting in particular as an incident angle of a predetermined range, Although it can select suitably according to the objective, 0 degrees-70 degrees are preferable. When the incident angle exceeds 70 °, the interface reflection component may increase.

  There is no restriction | limiting in particular as a structure of said 1st reflective structure, Although it can select suitably according to the objective, The 1st optical layer which has convex shape, and the reflective layer distribute | arranged on the said convex shape And a second optical layer having a concave shape that fills the convex shape in this order.

<<< First Optical Layer and Second Optical Layer >>>
It is preferable that the first optical layer and the second optical layer have at least visible light transparency. In the present invention, having visible light transmittance means a property that it is difficult to absorb visible light that has entered the optical layer, and it is not necessary to transmit 100% of visible light. For example, it is preferable to be transparent in the visible range.

  Examples of the material for forming the first optical layer and the second optical layer include a resin. Examples of the resin include a thermoplastic resin, an active energy ray curable resin, and a thermosetting resin.

The first optical layer and the second optical layer are light having a specific wavelength in the visible region in a range that does not impair transparency with respect to visible light from the viewpoint of imparting design properties to an optical member or a window material. It may have the characteristic of absorbing
The designability, that is, the property of absorbing light having a specific wavelength in the visible region can be performed, for example, by adding a pigment to the first optical layer and the second optical layer.
The pigment is preferably dispersed in the resin.
The pigment to be dispersed in the resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include inorganic pigments and organic pigments. In particular, the pigment itself is an inorganic material having high weather resistance. It is preferable to use a pigment.

  The first optical layer has, for example, a structure that is one-dimensionally arranged or second-orderly arranged on the surface on which the reflective layer is formed. The pitch P of the structure is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 30 μm to 5 mm, more preferably 50 μm to 1 mm, and particularly preferably 50 μm to 500 μm.

  There is no restriction | limiting in particular as a shape of the said structure, According to the objective, it can select suitably, For example, prism shape, lenticular shape, hemispherical shape, corner cube shape etc. are mentioned. When the structure has a prism shape, the inclination angle of the prism-shaped structure is preferably 45 ° or more, for example. From the viewpoint of reflecting a large amount of light incident from the sky and returning it back to the sky, the structure preferably has a flat surface or a curved surface with an inclination angle of 45 ° or more. By adopting such a shape, the incident light returns to the sky with almost one reflection, so that the incident light can be reflected efficiently in the upward direction even if the reflectance of the reflective layer is not so high, and in the reflective layer. This is because light absorption can be reduced.

An example of the shape of the first optical layer is shown using the drawings.
A structure 2S shown in FIGS. 13A to 13C is a columnar convex portion extending in one direction, and the columnar structures 2S are arranged one-dimensionally in one direction.
FIG. 13D and FIG. 13E show an example of a hexagonal close-packed array in which the structures 2S having triangular bottom surfaces are two-dimensionally arranged in the close-packed state. In addition, the pitch P1 of the structures 2S is preferably selected as appropriate according to desired optical characteristics.
Since the reflective layer is deposited on the structure 2S, the shape of the reflective layer has the same shape as the surface shape of the structure 2S.

  The first optical layer and the second optical layer preferably have the same optical characteristics such as refractive index. More specifically, it is preferable that the first optical layer and the second optical layer are made of the same material having transparency in the visible region. By configuring the first optical layer and the second optical layer with the same material, the refractive indexes of both are equal, and thus the transparency of visible light can be improved. However, it should be noted that even if the same material is used as a starting source, the refractive index of the film finally produced may differ depending on the curing conditions in the film forming process.

  The first optical layer and the second optical layer preferably have transparency in the visible region. Here, the definition of transparency has two kinds of meanings, that is, less light absorption and no light scattering. In general, when it is said to be transparent, only the former may be pointed out, but in the present invention, it is preferable to have both.

<<< reflective layer >>>
The reflective layer reflects light.
The reflective layer does not need to reflect all wavelengths of light, and may reflect light having a wavelength that requires reflection. For example, near infrared light may be reflected, but visible light may be transmitted. Further, the reflective layer need not reflect 100% of the light having the reflected wavelength.

  The reflection layer preferably has a so-called near-infrared selective reflection characteristic that has a reflection characteristic with respect to near infrared rays but has a transmission characteristic with respect to visible light. By doing so, the solar radiation adjusting device which can take in visible light indoors and is excellent in the daylighting property is obtained.

The reflective layer preferably includes at least one of a metal thin film, a metal oxide thin film, and a metal nitride thin film.
The reflective layer may have a single layer structure or a multilayer structure. By adopting a multilayer structure, desired near infrared selective reflection characteristics can be easily obtained. In particular, a desired near-infrared selective reflection characteristic can be more easily obtained by using one or a plurality of multilayer structures of a metal thin film, a metal oxide thin film, and a metal nitride thin film.

There is no restriction | limiting in particular as said metal, According to the objective, it can select suitably, For example, a metal simple substance, an alloy, etc. are mentioned.
There is no restriction | limiting in particular as said metal simple substance, According to the objective, it can select suitably, For example, Au, Ag, Cu, Al, Ni, Cr, Ti, Pd, Co, Si, Ta, W, Mo, Ge etc. are mentioned.
The alloy is not particularly limited and may be appropriately selected depending on the intended purpose. However, Ag-based, Cu-based, Al-based, Si-based or Ge-based materials are preferable, and AlCu, AlTi, AlCr, AlCo, AlNdCu are preferable. AlMgSi, AgPdCu, AgPdTi, AgCuTi, AgPdCa, AgPdMg, and AgPdFe are more preferable. In order to suppress corrosion of the metal layer, it is preferable to add materials such as Ti and Nd to the metal layer. In particular, when Ag is used as the material of the metal layer, it is preferable to add Ti and Nd.
Among these, as the metal, Ag and an Ag alloy are preferable from the viewpoint of excellent reflectivity.

  The metal oxide is not particularly limited and can be appropriately selected depending on the purpose. For example, niobium oxide, tantalum oxide, titanium oxide, indium tin oxide, silicon dioxide, cerium oxide, tin oxide, aluminum oxide, Examples thereof include aluminum-doped zinc oxide.

  There is no restriction | limiting in particular as said metal nitride, According to the objective, it can select suitably, For example, silicon nitride, aluminum nitride, titanium nitride etc. are mentioned.

  There is no restriction | limiting in particular as average thickness of the said reflection layer, Although it can select according to the objective, 100 nm or more and 20 micrometers or less are preferable, 100 nm or more and 5 micrometers or less are more preferable, 100 nm or more and 1 micrometer or less are especially preferable. When the average thickness of the reflective layer exceeds 20 μm, the optical path through which transmitted light is refracted becomes long, and the transmitted image tends to appear distorted.

  There is no restriction | limiting in particular as a formation method of the said reflection layer, According to the objective, it can select suitably, For example, sputtering method, vapor deposition method, CVD (Chemical Vapor Deposition) method, Dip coating method, Die coating method, Wet method Examples thereof include a coating method and a spray coating method.

  There is no restriction | limiting in particular as a manufacturing method of said 1st optical layer and said 2nd optical layer, According to the objective, it can select suitably, For example, 1st as described in Unexamined-Japanese-Patent No. 2010-160500 Examples thereof include a method for producing an optical layer and a second optical layer.

  Regarding the reason why retroreflectivity is obtained by the first optical layer, the second optical layer, and the reflective layer, and preferred embodiments of the shape of the structure, for example, JP 2010-160500 A It can be grasped by referring to the publication.

<< second reflection structure >>
The slat has a second reflective structure on the second main surface side.
The second reflecting structure has specular reflection characteristics for specularly reflecting near infrared rays incident from the second main surface side. The second reflection structure may or may not regularly reflect visible light incident from the second main surface side.
The second reflecting structure is not particularly limited as long as it has specular reflection characteristics for specularly reflecting near-infrared rays incident from the surface, and can be appropriately selected according to the purpose, but has a reflective layer. Is preferred.
Moreover, it is preferable that said 2nd reflection structure has a regular reflection characteristic which reflects visible light at least partially. By doing so, the direction of visible light transmitted through the first reflective structure and reaching the second reflective structure is changed, and the progress of visible light upward in the room is further enhanced. Here, the reason why it is at least partly is that it does not require regular reflection characteristics with respect to visible light in a place where it is not exposed to sunlight.

  The second reflective structure is not particularly limited as long as it regularly reflects near infrared rays incident from the second main surface side and advances the near infrared rays to the indoor side, and may have a curved surface. .

<<< reflective layer >>>
There is no restriction | limiting in particular as a shape of the said reflection layer, Although it can select suitably according to the objective, It is preferable that it is flat form.

  The reflection layer preferably has a so-called near-infrared selective reflection characteristic that has a regular reflection characteristic with respect to near infrared rays but has a transmission characteristic with respect to visible light. By doing so, the solar radiation adjusting device which can take in visible light indoors and is excellent in the daylighting property is obtained. Furthermore, when the reflective layer has regular reflection characteristics with respect to visible light and near infrared light, the directionality of lighting is more excellent.

The reflective layer preferably includes at least one of a metal thin film, a metal oxide thin film, and a metal nitride thin film. By doing so, the reflectivity with respect to light becomes high.
The reflective layer may have a single layer structure or a multilayer structure. By adopting a multilayer structure, desired near infrared selective reflection characteristics can be easily obtained.

There is no restriction | limiting in particular as said metal, According to the objective, it can select suitably, For example, a metal simple substance, an alloy, etc. are mentioned.
There is no restriction | limiting in particular as said metal simple substance, According to the objective, it can select suitably, For example, Au, Ag, Cu, Al, Ni, Cr, Ti, Pd, Co, Si, Ta, W, Mo, Ge etc. are mentioned.
The alloy is not particularly limited and may be appropriately selected depending on the intended purpose. However, Ag-based, Cu-based, Al-based, Si-based or Ge-based materials are preferable, and AlCu, AlTi, AlCr, AlCo, AlNdCu are preferable. AlMgSi, AgPdCu, AgPdTi, AgCuTi, AgPdCa, AgPdMg, and AgPdFe are more preferable. In order to suppress corrosion of the metal layer, it is preferable to add materials such as Ti and Nd to the metal layer. In particular, when Ag is used as the material of the metal layer, it is preferable to add Ti and Nd.
Among these, as the metal, Ag and an Ag alloy are preferable from the viewpoint of excellent reflectivity.

  The metal oxide is not particularly limited and can be appropriately selected depending on the purpose. For example, niobium oxide, tantalum oxide, titanium oxide, indium tin oxide, silicon dioxide, cerium oxide, tin oxide, aluminum oxide, Examples thereof include aluminum-doped zinc oxide.

  There is no restriction | limiting in particular as said metal nitride, According to the objective, it can select suitably, For example, silicon nitride, aluminum nitride, titanium nitride etc. are mentioned.

There is no restriction | limiting in particular as average thickness of the said reflection layer, Although it can select according to the objective, 10 nm or more is preferable.
When the reflective layer is a so-called thin film, the average thickness is more preferably 10 nm to 20 μm, still more preferably 10 nm to 5 μm, and particularly preferably 10 nm to 1 μm.
However, when the reflective layer itself is used as the second reflective structure, the reflective layer is not a so-called thin film but may be a thicker plate. In that case, the thickness of the reflective layer may be several mm.

  There is no restriction | limiting in particular as a formation method of the said reflection layer, According to the objective, it can select suitably, For example, sputtering method, vapor deposition method, CVD (Chemical Vapor Deposition) method, Dip coating method, Die coating method, Wet method Examples thereof include a coating method and a spray coating method.

<< First transparent layer >>
The slat may be provided with a first transparent layer having optical transparency on the first main surface side of the first reflective structure. In this case, for example, the surface on the first main surface side of the first transparent layer becomes the first main surface.

  There is no restriction | limiting in particular as a material of said 1st transparent layer, According to the objective, it can select suitably, For example, resin etc. are mentioned. Examples of the resin include polyethylene terephthalate, polyethylene, polypropylene, acrylic resin, and polycarbonate.

  There is no restriction | limiting in particular as average thickness of said 1st transparent layer, Although it can select suitably according to the objective, 20 micrometers-300 micrometers are preferable, and 50 micrometers-200 micrometers are more preferable.

<< second transparent layer >>
The slat may be provided with a second transparent layer having optical transparency on the second main surface side of the second reflecting structure. In this case, for example, the surface on the second main surface side of the second transparent layer becomes the second main surface.

  There is no restriction | limiting in particular as a material of said 2nd transparent layer, According to the objective, it can select suitably, For example, resin etc. are mentioned. Examples of the resin include polyethylene terephthalate, polyethylene, polypropylene, acrylic resin, and polycarbonate.

  There is no restriction | limiting in particular as average thickness of said 2nd transparent layer, Although it can select suitably according to the objective, 20 micrometers-300 micrometers are preferable, and 50 micrometers-200 micrometers are more preferable.

  The first transparent layer and the second transparent layer can reinforce the slats without deteriorating the optical characteristics of the first reflective structure and the second reflective structure.

Here, FIG. 14 shows an example of a slat having a first transparent layer and a second transparent layer.
The slat shown in FIG. 14 has a second transparent layer 5, a second reflecting structure 3, a first reflecting structure 2, and a first reflecting surface from the second main surface 1B side toward the first main surface 1A. One transparent layer 4 is provided in this order.
The first reflective structure 2 includes a first optical layer 2A having a convex shape, a reflective layer 2B disposed on the convex shape, and a second optical layer having a concave shape to make up the convex shape. 2C in this order.

Furthermore, another example of the slat will be described.
The slat shown in FIG. 15 moves the light diffusion layer 6, the second reflection structure 3, and the first reflection structure 2 in this order from the second main surface 1B side toward the first main surface 1A. Have.
The first reflective structure 2 includes a first optical layer 2A having a convex shape, a reflective layer 2B disposed on the convex shape, and a second optical layer having a concave shape to make up the convex shape. 2C in this order.
The light diffusion layer 6 has light diffusibility with respect to visible light. The light diffusion layer 6 can be formed, for example, by dispersing particles having different refractive indexes (for example, inorganic fine particles) in a resin.
The first optical layer 2A also has light diffusibility with respect to visible light. The first optical layer 2A can be formed, for example, by dispersing particles having different refractive indexes (for example, inorganic fine particles) in a resin.
The second optical layer 2C also has light diffusibility with respect to visible light. The second optical layer 2C can be formed, for example, by dispersing particles having different refractive indexes (for example, inorganic fine particles) in a resin.

If you try to capture much of the visible light indoors using the interface reflection (regular reflection) on the slat surface, depending on the incident angle, the specular reflection light may directly enter the eyes of an indoor person and feel dazzling. is there.
In the case of the slat shown in FIG. 15, the anti-glare property can be imparted by diffusing the light entering the room by the light diffusibility of the first optical layer 2A, the second optical layer 2C and the light diffusion layer 6.
In FIG. 15, the first optical layer 2 </ b> A, the second optical layer 2 </ b> C, and the light diffusion layer 6 are provided with light diffusibility. However, the slat may have the following modes.
-Light diffusivity is imparted only to the second optical layer 2C (the light diffusing layer 6 is not provided).
Light diffusibility is imparted to the first optical layer 2A and the second optical layer 2C (the light diffusing layer 6 is not provided). Furthermore, the light diffusibility of the first optical layer 2A is set to a weak light diffusibility that does not inhibit the retroreflectivity.
In particular, of the first optical layer 2A and the second optical layer 2C, the first optical layer 2A and the reflective layer 2B that are nearly transparent by imparting light diffusibility only to the second optical layer 2C. While the near infrared rays are retroreflected, only the visible light transmitted through the reflective layer 2B is diffused by the second optical layer 2C, so that the antiglare property is exhibited without inhibiting the retroreflectivity.

<Other members>
There is no restriction | limiting in particular as said other member, According to the objective, it can select suitably, For example, a slat support body etc. are mentioned.

<< Slat Support >>
The slat support is not particularly limited as long as it is a member that supports the plurality of slats in the solar radiation adjusting device, and can be appropriately selected according to the purpose. For example, a frame, a rod, etc. Can be mentioned.

  Examples of the frame include a frame 10 as shown in FIGS. 3A and 3B. The frame 10 is arranged so as to surround a plurality of slats 1 arranged in the longitudinal direction of the slats 1. The slat 1 is supported by the frame body 10 at both ends in the longitudinal direction, for example.

  Examples of the rod include a rod 11 as shown in FIGS. 4A and 4B. The rod 11 penetrates the slat 1 and supports the slat 1.

Furthermore, as shown in FIG. 16, the first main surface 1A and the second main surface 1B may not be parallel to each other as the shape of the slats.
Moreover, as shown in FIG. 17, the 2nd main surface 1B may be a convex curved surface.

  The said solar radiation adjustment apparatus can be installed and used for the opening of the wall of buildings, such as a house, a building, a factory, a warehouse, as a blind, a louver apparatus etc., for example.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Measurement and simulation conditions)
The shielding structure and transparency of the reflective structure alone and slats and the solar control device against solar radiation were evaluated. Evaluation was performed by actual measurement and simulation.

<Incident angle>
Here, the definition of the incident angle in the evaluation will be described.
FIG. 18A is a diagram for explaining the incident angle when evaluating the shielding property and the transmittance of the reflecting structure body and slats against solar radiation.
The incident angle is 0 ° to the perpendicular to the surface of the reflective structure 30.

FIG. 18B is a diagram for explaining an incident angle when evaluating the shielding property and the transmittance with respect to the solar radiation of the solar radiation adjusting device.
The said incident angle makes the perpendicular to the arrangement | sequence direction (L) of the slat 1 0 degree.

<Measurement conditions>
In the evaluation, a reflection incident angle variable integrating sphere manufactured by Lambda Vision was used for the actual measurement.
The measurement conditions are as follows.
・ Integral sphere part outline: 200mmΦ
Inner wall reflective paint: Barium sulfate Light receiving port: One side FC connector installed Light emitting port: Irradiation angle 8 to 85 degrees Variable long hole port (12mm width)
Sample stand: 170mmΦ (within integrating sphere)
Opening ratio: about 3%
Others: Sample installation on sample stage by integration hemisphere desorption ・ Irradiation part Irradiation angle: 8 degrees to 85 degrees Angle setting mechanism: Automatic rotating arm system ・ Lamp 12V150W halogen lamp Spectralon manufactured by Labsphere, USA A reflection standard was used.
As the absorber, Spectral Black manufactured by Actor Japan was used. Absorbers were arranged on the bottom and side surfaces of the measurement sample so as to absorb the transmission component and the specular reflection component. The area of the side absorber is minimized at an inclination angle of 20 ° so that the measurement can be performed with an incident angle of ≧ 20 °.
For both total light reflection and retroreflection, (1) “measurement sample + absorber” and (2) “standard reflection plate” were placed in the integrating sphere by replacing them with the incident light irradiation position, and measured alternately. The absorption of the multiple reflection component by the absorber was corrected by alternating measurement, and the reflectance was obtained by the following formula “reflectance = (1) / (2)”.
Based on the obtained spectral reflectance, the solar reflectance and the infrared reflectance were calculated according to JIS A5759.

<Simulation>
Light Tools, which is lighting design analysis software, was used for the simulation.

(Experimental example 1)
<Optical characteristics of reflective structure>
The optical characteristics of the reflective structure 30A shown in FIG. 19 were investigated. The reflective structure 30A corresponds to the first reflective structure. The reflective structure 30A includes a first optical layer 2A having a convex shape, a reflective layer 2B disposed on the convex shape, and a second optical layer 2C having a concave shape to make up the convex shape. Have in this order. Further, the first optical layer 2A side has a first transparent layer 4A made of polyethylene terephthalate (average thickness 50 μm), and the second optical layer 2C side has a second transparent layer 5A made of polyethylene terephthalate ( Average thickness 50 μm).
Optical characteristics of the reflective structure 30A having the following reflective layers 2B were investigated.
Reflective layer (A1): reflective layer (average thickness 100 nm) on which an Ag alloy (Ag, Pd, Cu) is formed
Reflective layer (B1): AZO (4 nm) / Nb ₂ O ₅ (25 nm) / AZO (4 nm) / APC (10 nm) / Nb ₂ O ₅ (70 nm) / on the first optical layer 2A on the incident side A reflective layer in which AZO (5 nm) / APC (10 nm) / Nb ₂ O ₅ (30 nm) are laminated in this order

Below, the manufacturing method of 30 A of reflective structures shown in FIG. 19 is shown. In the following manufacturing method, the reflective layer (B1) was formed as the reflective layer 2B.
According to the method described in paragraphs [0115] to [0116] of Japanese Patent Application Laid-Open No. 2010-160500, a mold shown in FIG. 20 is manufactured, and a prism-shaped forming surface is formed using the mold. A layer (first optical layer 2A) was obtained.
Next, AZO (4 nm) / Nb ₂ O ₅ (25 nm) / AZO (4 nm) / APC (10 nm) / Nb ₂ O ₅ (70 nm) is applied to the molding surface on which the prism shape is formed by the mold. ) / AZO (5 nm) / APC (10 nm) / Nb ₂ O ₅ (30 nm) were laminated in this order to obtain a reflective layer 2B as a near-infrared selective reflection layer.
Here, “AZO” means “aluminum-doped zinc oxide”, and “APC” means an Ag alloy (Ag, Pd, Cu).
Next, the mixed resin described in paragraph [0115] of JP 2010-160500 A is applied again on the reflective layer 2B, and after extruding bubbles, a PET film is placed and irradiated with UV light. The resin was cured to form a resin layer (second optical layer 2C) on the reflective layer 2B.
Thus, a reflective structure 30A (average thickness 200 μm) was obtained.

For each of the reflective layer (A1) and the reflective layer (B1), the solar radiation transmittance and the solar reflectance were measured. The results are shown in FIGS. 21A to 21D. At the time of measurement, the reflecting structure was arranged so that solar radiation was incident on the longer slope of the prism shape in the reflecting structure. The same applies to the following experimental examples.
FIG. 21A is a simulation result of solar transmittance in the case of the reflective layer (A1).
FIG. 21B is a simulation result of solar transmittance in the case of the reflective layer (B1).
FIG. 21C is a simulation result of solar reflectance in the case of the reflective layer (A1).
FIG. 21D shows an actual measurement result and a simulation (Sim) result of solar reflectance in the case of the reflective layer (B1).
The following is derived from the above results.
When the incident angle is small, a lot of light reaches the reflection layer 2B and is retroreflected.
As the incident angle increases, regular reflection at the incident interface increases, the interface reflection component increases, and both retroreflection and transmission decrease.

Next, the reflection spectrum (60 ° incidence) in the case of the reflective layer (B2) was measured. The results are shown in FIG. 21E.
The following is derived from the above results.
The solar reflectance at the time of 60 ° incidence of the reflective layer (B2) is less than 20%, but it reflects about 60% in the near infrared region.
-On the other hand, most of visible light is transmitted only by regular reflection at the incident interface.
-This is a result of emphasizing daylighting, and if visible light is added to the reflection area, the solar reflectance increases.

(Experimental example 2)
<Optical characteristics of reflective structure>
The optical characteristics of the reflective structure 30B shown in FIG. 22 were investigated. The reflective structure 30B corresponds to the second reflective structure. The reflective structure 30B has a reflective layer 3A. Further, the second transparent layer 5A (average thickness 50 μm) made of polyethylene terephthalate is provided on the incident side of the reflective layer 3A, the UV curable resin layer 3B is provided on the opposite side to the incident side, and the first transparent layer made of polyethylene terephthalate. 4A (average thickness 50 μm) in this order.
Optical characteristics of the reflective structure 30B having the following reflective layers were investigated.
Reflective layer (A2): reflective layer (average thickness 100 nm) on which an Ag alloy (Ag, Pd, Cu) is formed
Reflective layer (B2): AZO (4 nm) / Nb ₂ O ₅ (25 nm) / AZO (4 nm) / APC (10 nm) / Nb ₂ O ₅ (70 nm) / AZO (5 nm) on the first optical layer 2A / APC (10 nm) / Nb ₂ O ₅ (30 nm) laminated in this order

The solar radiation transmittance and the solar reflectance were measured for each of the reflective layer (A2) and the reflective layer (B2). The results are shown in FIGS. 23A to 23D. Note that light enters the reflecting structure 30B from below in FIG.
FIG. 23A is a simulation result of solar transmittance in the case of the reflective layer (A2).
FIG. 23B is a simulation result of solar transmittance in the case of the reflective layer (B2).
FIG. 23C is a simulation result of solar reflectance in the case of the reflective layer (A2).
FIG. 23D is a simulation result of solar reflectance in the case of the reflective layer (B2).
The following is derived from the above results.
・ Because it is incident on a flat optical layer and a reflective layer, both transmission and reflection are monotonously increased or decreased (behavior of interface reflection).
-Regarding the reflective layer (A2) (Ag alloy film), the original regular reflectance is high, there is no angle dependence, and regular reflection≈100%, and transmission = 0%.

Next, the reflection spectrum (60 ° incidence) in the case of the reflective layer (A2) was measured by simulation. The results are shown in FIG. 23E.
The following is derived from the above results.
-The regular reflectance was close to 100% in the entire band.

(Experimental example 3)
<Optical characteristics of slats and solar radiation adjusting device>
Optical characteristics of the slat shown in FIG. 24 and the solar radiation adjusting device shown in FIG. 25 were investigated.
A slat 1 shown in FIG. 24 includes a second transparent layer 5, a second reflective structure 3, a first reflective structure 2, and a first transparent layer 4 in this order.
The first reflective structure 2 includes a first optical layer 2A having a convex shape, a reflective layer 2B disposed on the convex shape, and a second optical layer having a concave shape to make up the convex shape. 2C in this order. The first optical layer 2A and the second optical layer 2C transmit at least visible light.
The first transparent layer 4 is made of polyethylene terephthalate (average thickness 50 μm) and has a flat surface. This surface is also the first main surface of the slat 1.
The second reflective structure 3 has a reflective layer.
The second transparent layer 5 is made of polyethylene terephthalate (average thickness 50 μm).
The solar radiation adjusting device shown in FIG. 25 is obtained by arranging the slats 1 shown in FIG. 24 at a slat angle of 30 °.

  The slats shown in FIG. 24 used in the solar radiation adjusting device shown in FIG. 25 are configured as shown in Table 2 by applying the reflective layer used in Experimental Examples 1 and 2.

In addition, two types of thermal barrier films were used as comparison objects.
As the heat shield film A, the reflective structure 30B (specular reflection type) of Experimental Example 2 was used. In the reflective structure 30B, the reflective layer uses the reflective layer B2.
As the thermal barrier film B, the reflective structure 30A (retroreflective type) of Example 1 was used. In the reflective structure 30A, the reflective layer uses the reflective layer B2.

The solar transmittance, solar reflectance, visible light transmittance, visible light reflectance, near infrared transmittance, and near infrared reflectance were measured by simulation.
The results are shown in FIGS. 26A to 24C, FIGS. 27A to 27C, and FIGS. 28A to 28C.

<Solar radiation transmittance and solar reflectance>
The following is derived from the results of solar transmittance and solar reflectance.
・ The solar radiation adjustment device clearly shows a significant improvement in solar radiation indoors compared to the thermal barrier film. On the other hand, the uptake in summer is equivalent to a thermal barrier film. In other words, solar radiation is optimized in winter and summer.
・ The heat-shielding film has high solar reflectance at high altitudes in the south, middle, but the interface reflection component is increased, and there is concern about heat damage to the ground surface. This can be seen by looking at the recursive component.
-Most of the reflection components of the solar radiation control device are recursive components and do not cause heat damage to the ground surface.
-Increasing the reflectivity is possible by increasing the reflectivity in the visible range.

<Visible light transmittance and visible light reflectance>
The following is derived from the results of the visible light transmittance and the visible light reflectance.
-As for the solar radiation adjusting device to which the near-infrared selective reflection layer is applied, the visible light transmittance is higher than that of the thermal barrier film throughout the year (good lighting performance).
・ Transmission decreases as the reflectance of visible light increases.
-The solar radiation adjusting device to which the near-infrared selective reflection layer is applied has little reflection to the outdoors because visible light is reflected at the interface or transmitted through the slat.
・ The thermal barrier film reflects all visible light in the ground direction.
-Since Ag alloy (Ag, Pd, Cu) also reflects visible light, when Ag alloy is applied to the reflective layer of the 1st reflective structure which is a retroreflective structure, visible light is retroreflected.
The solar radiation adjusting devices 2 and 3 efficiently capture visible light, do not reflect outdoors, and do not cause light damage (dazzling or complaints) due to reflected light.

<Near-infrared transmittance and near-infrared reflectance>
The following is derived from the results of the near infrared transmittance and the near infrared reflectance.
-Basically, the behavior of solar radiation transmittance and solar reflectance is the same, but the solar radiation adjustment device is more suitable for solar radiation in winter and summer than the shielding film. It can be confirmed more conspicuously.

As is clear from the above, according to the solar radiation adjusting device of the present invention, the retroreflective characteristics and the regular reflection characteristics are combined, and the amount of light passing into the indoor side is changed according to the light incident angle, so In winter, it is possible to optimize the shielding effect in summer and winter without adjusting the slats.In addition, retroreflection in the incident direction reduces the influence of reflection on other buildings and the surface of the ground. It becomes possible to prevent.
In addition, at least one of the retroreflective structure (first reflective structure) and the regular reflective structure (second reflective structure) of the slats has a near infrared selective reflection characteristic and imparts visible light transparency. By doing so, visible light can be taken indoors, and the lighting performance can be improved.

(Experimental example 4)
The optical characteristics (transmittance) of the solar radiation adjusting device when the reflecting structure 30A shown in FIG. 19 was used as a slat were investigated and compared with the solar radiation adjusting devices 1 to 3 investigated in Experimental Example 3. Similar to Experimental Example 3, the slat angle was set to 30 °, and the optical characteristics were examined in the same manner as in Experimental Example 3. The results are shown in FIGS. 29A to 29C.
Here, the solar radiation adjustment apparatus A used the reflective structure 30A [Retroreflection type: Near-infrared selective reflection type: Reflective layer (B1)] of Experimental Example 1 as a slat.
The solar radiation adjusting device B used the reflective structure 30A [Retroreflection type: Total light reflection type: Reflective layer (A1)] of Experimental Example 1 as a slat.

  The solar radiation transmittance of the solar radiation adjusting device A is high throughout the year, and tends to take both near-infrared light and visible light indoors in summer. On the other hand, the solar radiation adjusting device B has low daylighting in the summer.

  Further, regarding the solar radiation adjusting device A and the solar radiation adjusting device 3, the angular distribution of the transmitted light in May / July was examined. The results are shown in Table 3. In the angle distribution of the visible light transmitted light in May / July, the solar radiation adjusting device 3 tends to deliver visible light above the horizontal and make the ceiling direction brighter than the solar radiation adjusting device A. This is a desirable tendency for indoor lighting. On the other hand, with respect to the solar radiation adjusting device A, the light that travels almost straight from the sun reaches below the horizontal plane, so that the effect of brightening the room is small. The effect of this solar radiation adjusting device A is due to the reflection of visible light by the second reflecting structure, and by changing the relative angle with the first reflecting structure as appropriate, the ceiling direction closer to the top is further increased. It can also be brightened.

Here, the transmission angle in Table 3 refers to an angle as shown in FIG. That is, 0 ° is the progress in the horizontal direction, the positive angle is the progress in the upward direction, and the negative angle is the progress in the downward direction. And, as the absolute value is larger, it means that the absolute value is delivered upward or downward.
The results of Table 3 are shown schematically.
FIG. 31 is a schematic diagram showing the state of reflection and transmission of the solar radiation adjusting apparatus A.
FIG. 32 is a schematic diagram showing the state of reflection and transmission of the solar radiation adjusting device 3.
31 and 32, it can be confirmed that the solar radiation adjusting device 3 tends to brighten the ceiling direction by delivering visible light from above the horizontal, compared to the solar radiation adjusting device A.

  The solar radiation adjusting device of the present invention can be suitably used for blinds, louver devices and the like.

1 slat
DESCRIPTION OF SYMBOLS 1A 1st main surface 1B 2nd main surface 2 1st reflection structure 2A 1st optical layer 2B reflection layer 2C 2nd optical layer 2S structure 3 2nd reflection structure 3A reflection layer 3B UV hardening Resin layer 4 First transparent layer 5 Second transparent layer 6 Light diffusion layer 10 Frame body 11 Rod body 21 Head box 22 Ladder cord 23 Operation rod 24 Operation section 25 Lift code 26 Knob 27 Bottom rail 30 Reflective structure 30A Reflection Structure 30B Reflective structure

Claims (11)

Having a plurality of slats,
Each of the plurality of slats has a first main surface having a flat surface, and a second main surface opposite to the first main surface,
Each of the plurality of slats has a first reflective structure on the first main surface side and a second reflective structure on the second main surface side,
The first reflective structure has a retroreflective characteristic for retroreflecting near infrared rays incident from the first main surface side at an incident angle within a predetermined range;
The second reflection structure has specular reflection characteristics for specularly reflecting near infrared rays incident from the second main surface side,
The plurality of slats are arranged with the first main surface on the same side in a direction crossing the longitudinal direction with the longitudinal direction parallel.
A solar radiation adjusting device characterized by that.   The first reflective structure includes a first optical layer having a convex shape, a reflective layer disposed on the convex shape, and a second optical layer having a concave shape to make up the convex shape. The solar radiation adjustment apparatus of Claim 1 which has in this order.   The solar radiation adjusting apparatus according to claim 2, wherein the convex shape of the first optical layer is a convex shape formed by one of a one-dimensional array and a two-dimensional array of a large number of structures.   The solar radiation adjusting device according to claim 3, wherein the shape of the structure is any one of a prism shape, a lenticular shape, a hemispherical shape, and a corner cube shape.   5. The solar radiation adjusting device according to claim 2, wherein the reflective layer includes at least one of a metal thin film, a metal oxide thin film, and a metal nitride thin film.   The solar radiation adjusting device according to any one of claims 1 to 5, wherein the second reflective structure has a reflective layer.   The solar radiation adjusting apparatus according to claim 6, wherein the reflective layer in the second reflective structure has a metal thin film.   The solar radiation adjusting device according to claim 7, wherein the metal is one of Ag and an Ag alloy.   The solar radiation adjusting device according to any one of claims 1 to 8, wherein a slat angle of each of the plurality of slats is 20 ° to 40 °.   The solar radiation adjusting apparatus according to any one of claims 1 to 9, wherein the first reflective structure has visible light transparency, and the second reflective structure has visible light transparency. A slat used in a solar radiation adjusting device,
A first main surface having a flat surface and a second main surface on the opposite side of the first main surface;
Having a first reflective structure on the first main surface side and having a second reflective structure on the second main surface side;
The first reflective structure has a retroreflective characteristic for retroreflecting near infrared rays incident from the first main surface side at an incident angle within a predetermined range;
The second reflective structure has specular reflection characteristics for specularly reflecting near infrared rays incident from the second main surface side.
A slat characterized by that.