JP6089692B2 - Daylighting sheet, daylighting device, and building - Google Patents

Description

  The present invention relates to a daylighting sheet, a daylighting apparatus, and a building using the daylighting sheet for incorporating outside light such as sunlight into a building or the like.

  It is well known to use a so-called window glass to form a bright and comfortable indoor space by taking in outside light such as sunlight inside a building. On the other hand, however, if the outside light incident on the window glass is taken into the room as it is, there may be a problem such as feeling glare. On the other hand, several techniques have been proposed in which direct sunlight is controlled and light is taken indoors in a more comfortable manner.

  Patent Document 1 discloses a light control sheet for controlling sunlight intake arranged at a site where sunlight is taken into a building. This is composed of a light-transmitting part that transmits sunlight and a light-shielding part group that absorbs sunlight, and the light-shielding part group has a plurality of light-shielding parts arranged at a predetermined pitch in one direction in the sheet. .

  Patent Document 2 discloses a plate-shaped daylighting optical element provided at an opening of a building so as to take in sunlight. This is composed of a large number of prism parts arranged on the same plane, and the slope of each prism part transmits sunlight when the elevation angle of the sun is smaller than the critical elevation angle, and all the slopes when the elevation angle is greater than or equal to the critical elevation angle. The angle of reflection is such that the total amount of light collected when the elevation angle of the sun is greater than or equal to the critical elevation angle is less than the total amount of light harvested when it is less than the critical elevation angle.

JP 2010-259406 A JP 2003-157707 A

However, in the light control sheet having a configuration as disclosed in Patent Document 1, a part of the outside light (sunlight) is absorbed by the light shielding unit group, and thus the light control sheet is applied to a window of a building or the like. In such a case, it was difficult to absorb the outside light and effectively incorporate the outside light into the room.
In addition, in the technique disclosed in Patent Document 2, it is possible to control light incident from the outside. However, since the image is refracted when viewed from the indoor side, it is clear for viewing the outside scenery. There was a shortage. Furthermore, the daylighting optical element disclosed in Patent Document 2 has a problem in durability because the prism-shaped unevenness is exposed to the indoor side, and is easily damaged depending on the installation location.

  In view of the above-described problems, an object of the present invention is to provide a daylighting sheet that is capable of suppressing direct sunlight (direct light) and efficiently daylighting so that the outdoor side can be seen from the indoor side. Moreover, the lighting apparatus and building using this are provided.

  The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are added in parentheses, but the present invention is not limited to the illustrated embodiment.

The invention according to claim 1 is a daylighting sheet (20) in the form of a sheet disposed in a building opening so that the sheet surface is vertical, and is a sheet-like base material layer (22) having translucency. ) And a light deflection layer (23) formed on one surface of the base material layer for deflecting light, and a plurality of the light deflection layers are arranged side by side along the one surface of the base material layer. A light transmitting portion (24) that transmits light and a light deflecting portion (25) that is disposed between adjacent light transmitting portions and is filled with a material having a lower refractive index than the light transmitting portion, and a daylighting sheet. In the thickness direction of the daylighting sheet, the light deflection part is a polygonal line or a curved line so that the upper side is convex downward, comprising side edges (25b) is as a whole has a small step-like uneven shape together with a straight line, A light sheet.

According to the second aspect of the present invention, in the daylighting sheet (20) of the first aspect, the minute step-like irregularities have a size of 1 μm or more and 50 μm or less in the thickness direction, and 0. It is 5 μm or more and 10 μm or less .

  The invention according to claim 3 is the daylighting sheet (20) according to claim 1 or 2, wherein the light deflector (25) contains a material that scatters light.

  The invention according to claim 4 is a plate-like panel (13) having translucency, and the daylighting sheet (20) according to any one of claims 1 to 3, which is attached to one surface of the panel. And a frame (11) arranged so as to surround at least the periphery of the panel.

  Invention of Claim 5 is a building (1) in which the lighting device of Claim 4 was installed in the opening part formed in the wall.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing the direct sunlight (direct light), it can light efficiently and it becomes possible to see the outdoor side from the indoor side. Moreover, the reflection which can ask the state of the room inner side can be prevented.

It is a figure explaining a 1st form and is an external appearance perspective view of the building. It is the figure which looked at the lighting apparatus 10 from the front. It is a figure explaining the layer structure of the lighting panel. FIG. 5 is a diagram for explaining a form of a light deflection layer 23. It is a figure explaining the form of the edge | side 25b. FIG. 6A shows an example in which the side on the upper side of the light deflection unit is a convex curve, and FIG. 6B shows the side on the upper side of the light deflection unit formed by two straight lines. An example of a convex shape is shown below. This is an example in which the portion facing the outdoor side of the light deflection unit is concave. It is one figure explaining the effect of the daylighting sheet. 2 is an external perspective view of a mold roll 30. FIG. FIG. 4 is an enlarged view showing protrusions 32 and grooves 33 formed on the surface of a mold roll 30. It is a figure explaining the form of a chip. It is one figure which forms the protrusion 32 and the groove | channel 33 of a metal mold | die roll. It is another figure which forms the protrusion 32 and the groove | channel 33 of a metal mold | die roll. FIG. 10 is still another view of forming the protrusion 32 and the groove 33 of the mold roll. FIG. 6 is a diagram schematically showing stepped irregularities formed on a surface 32b of a protrusion 32. It is a figure explaining the scene which laminates | stacks a light deflection | deviation part on a base material layer. It is a figure explaining a 2nd form and is a figure equivalent to FIG.

  The above-described operation and gain of the present invention will be clarified from embodiments for carrying out the invention described below. Hereinafter, the present invention will be described based on embodiments shown in the drawings. However, the present invention is not limited to the embodiment. In the following drawings, the structure may be exaggerated for easy understanding. In addition, for ease of viewing in each figure, a part of the reference numerals that are repeated may be omitted.

FIG. 1 is a diagram illustrating a first embodiment, and is an external perspective view of a building 1 provided with a daylighting sheet 20 (see FIG. 3). The building 1 is a so-called office building, and an outer wall facing the south side is provided with a plurality of openings that communicate indoors and outdoors, and a daylighting device 10 including a daylighting sheet 20 is disposed therein.
FIG. 2 is a front view of one daylighting apparatus 10 viewed from the outdoor side. As described above, the daylighting apparatus 10 includes the frame 11 and the daylighting panel 12 arranged in the frame of the frame 11, and is configured as a so-called window. And the said lighting device 10 is arrange | positioned at the opening part of the building 1 as mentioned above.

  FIG. 3 schematically illustrates the layer configuration of the daylighting panel 12 in the vertical section of the daylighting apparatus 10 taken along the line III-III in FIG. In FIG. 3, the lighting panel 12 is shown in a posture attached to the building 1 so that the panel surface is vertical. The left side of FIG. 3 is the outdoor side, the right side is the indoor side, the upper side is the top side, and the paper surface. The lower side is the ground side.

  As can be seen from FIG. 3, the daylighting panel 12 includes a panel 13 and a daylighting sheet 20 bonded to the inner side surface of the panel 13. The daylighting sheet 20 includes a hard coat layer 21, a base material layer 22, a light deflection layer 23, and an adhesive layer 27 from the indoor side. Hereinafter, each of these layers will be described.

  The panel 13 is a plate-shaped translucent panel having translucency used for a normal building or a vehicle window such as a glass panel or a resin panel. Therefore, a known plate glass or resin plate can be used as a member constituting the panel 13. The frame 11 described above is disposed at least around the panel 13, so that the daylighting panel 12 is attached within the frame 11.

The hard coat layer 21 is a layer provided on the outermost surface of the daylighting sheet 20 opposite to the panel 13 for the purpose of surface protection. The hard coat layer 21 can be formed as a transparent resin layer, and is preferably formed as a cured resin layer formed by curing a curable resin from the viewpoint of resistance to scratches and surface contamination.
Specifically, an ionizing radiation curable resin, other known curable resins, or the like may be appropriately employed according to the required performance. Examples of the ionizing radiation curable resin include acrylate-based, oxetane-based, and silicone-based resins. For example, acrylate-based ionizing radiation curable resins include monofunctional (meth) acrylate monomers, bifunctional (meth) acrylate monomers, (meth) acrylate monomers such as trifunctional or higher (meth) acrylate monomers, urethane (meta ) Acrylate, epoxy (meth) acrylate, polyester (meth) acrylate and other (meth) acrylate ester oligomers or (meth) acrylate ester prepolymers. Examples of tri- or higher functional (meth) acrylate monomers include trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

Further, the hard coat layer 21 may be added with a function of improving the stain resistance. This can be achieved, for example, by adding a silicone compound, a fluorine compound, or the like. Further, as other functions, it may have a function of improving antistatic properties and water repellency.
As materials that can be used for improving the antistatic property, PEDOT-PSS (PEDOT (Poly (3,4-ethylenedioxythiophene); 3,4-ethylenedioxythiophene polymer) and PSS (polynesulfonate) are used for the electron conduction type. ); A styrene sulfonic acid polymer)), and the ionic conductive type includes lithium salt materials.
Examples of materials that can be used to improve water repellency include fluorine compounds.

The base material layer 22 is a layer that becomes a base material for forming the light deflection layer 23.
Therefore, the base material layer 22 has a light transmitting property and supports the light deflection layer 23 so as to prevent deformation. From this point of view, as specific examples of the material constituting the base material layer 22, for example, a transparent resin mainly composed of one or more of acrylic, styrene, polycarbonate, polyethylene terephthalate, acrylonitrile, and the like, epoxy acrylate, urethane acrylate The reactive resin (ionizing radiation curable resin etc.) can be mentioned.

  Although the thickness of the base material layer 22 is not specifically limited, It is preferable that they are 25 micrometers or more and 300 micrometers or less. If the thickness of the base material layer 22 is out of this range, there is a risk of causing problems in workability. For example, if the base material layer 22 is too thin, wrinkles are likely to occur. Moreover, if the base material layer 22 is too thick, winding will become difficult in an intermediate process among the processes which manufacture the daylighting sheet 20. FIG.

The light deflection layer 23 has a light transmission part 24 and a light deflection part 25. The light transmission part 24 has a cross section shown in FIG. 3 and is disposed so as to extend in one direction along the surface of the base material layer 22 (horizontal direction in the posture disposed in the building 1). A plurality of light transmission parts 24 are arranged at a predetermined interval along the surface of the base material layer 22 in a direction different from the direction (vertical direction in the posture arranged in the building 1). In this embodiment, the adjacent light transmission parts 24 are connected and integrated at the end part on the base material layer 22 side.
On the other hand, the light deflection unit 25 is disposed between the adjacent light transmission units 24.

FIG. 4 shows an enlarged view of a part of the light deflection layer 23.
The light transmitting portion 24 is a portion that transmits light, and the surface on the base material layer 22 side and the opposite side surface (the surface on the adhesive layer 27 side) of the light deflection layer 23 where the light transmitting portion 24 is disposed. Are preferably formed parallel and smooth. This makes it easier to see the outdoor scenery through the daylighting sheet 20 as will be described later. More preferably, the light transmission part 24 transmits light without scattering. This improves the visibility of the backside scenery. Here, “transmits without scattering light” means a portion formed without adding a material that intentionally scatters, and inevitably occurs when light passes through the material. Scattering is allowed to occur.

  In this embodiment, the light transmitting portion 24 has a substantially trapezoidal cross section between the adjacent light deflection portions 25 in the cross sections shown in FIGS. 3 and 4, and the outdoor side has a short upper bottom and the indoor side has a long lower bottom. Sides constituting the interface with the light deflecting unit 25 are leg portions. However, since the leg portion has a shape along the shape of the light deflection portion 25 as will be described later, the leg portion is not necessarily straight.

Examples of the material constituting the light transmitting portion 24 include transparent resins mainly composed of one or more of acrylic, styrene, polycarbonate, polyethylene terephthalate, acrylonitrile, etc., and epoxy acrylate or urethane acrylate reactive resins (ionizing radiation). Curable resin).
Here, the refractive index of the material constituting the light transmitting portion 24 may be the same as or different from the refractive index of the base material layer 22. However, if there is a difference in refractive index between the two, the possibility of light being deflected at the interface increases, so even if they are the same material or different materials, the refractive index difference is small or there is no refractive index difference. It is preferable. Here, the refractive index of the material forming the light transmitting portion 24 is preferably in the range of 1.49 to 1.56, more preferably 1.49 to 1.50, from the versatility of the raw materials.

  The light deflection unit 25 is a part formed between two adjacent light transmission units 24. In other words, as described above, the light transmission parts 24 are arranged in parallel in the direction along the sheet surface at a predetermined interval, and a groove-like recess having a predetermined shape is formed between the light transmission parts 24. The concave portion in this embodiment is a groove having a cross-sectional shape corresponding to the cross-sectional shape of the light deflection unit 25, and the light deflection unit 25 is formed by filling a material constituting the light deflection unit 25 therein. Therefore, the light deflection unit 25 has a cross-sectional shape based on the concave portion.

The light deflecting unit 25 is a part configured to be able to deflect the light irradiated here by totally reflecting the light. Therefore, the light deflection unit 25 is filled with a material having a lower refractive index than the light transmission unit 24. According to this, if the incident light satisfies the total reflection condition due to the difference in the refractive index between the light deflecting unit 25 and the light transmitting unit 24 and the angle of the light incident on the interface, the light is totally reflected here. Can be reflected and deflected. As will be described in detail later, the direction of the deflected light is changed, and for example, it can be eliminated from direct light that gives glare by irradiating the ceiling. The refractive index of the material forming the light deflection section 25 is preferably in the range of 1.49 to 1.56, more preferably 1.49 to 1.50, from the versatility of the raw materials.
Further, the refractive index difference between the light transmitting portion 24 and the light deflecting portion 25 at that time is 0.03 or more and 0.07 or less, more preferably 0.05 or more and 0.06 or less. In the range where the difference in refractive index is larger than 0 and smaller than 0.03, when wavelength dispersion during total reflection (dispersion due to different total reflection angles depending on the wavelength) occurs, long wavelength components are not totally reflected and short. Only the wavelength component may be totally reflected, which may cause a color change. On the other hand, if the refractive index difference is larger than 0.07, the refractive index of the short wavelength component tends to be larger than the refractive index of the long wavelength refractive index component, and rainbow-like unevenness may be remarkably exhibited. is there.

Furthermore, in this embodiment, the light deflection unit 25 has the following shape. This will be described with reference to FIG.
The light deflection unit 25 has a trapezoidal shape in the cross section shown in FIG. The trapezoidal shape is such that the long lower base is the outdoor side (upper bottom side of the light transmission part 24), the short upper base is the indoor side (lower base side of the light transmission part 24), and the upper and lower sides are leg parts.
When the side 25a on the upper side of the leg portion is in the posture shown in FIG. 4, the inclination angle thereof is the outdoor side at an angle θ _U with respect to the horizontal plane (the normal of the sheet surface of the daylighting sheet 20) ( (Sun side) Inclined upward.
On the other hand, the side 25b on the side opposite to the side 25a is the lower leg 25b, and the inclination angle of the side 25b is directed downward to the outdoor side at a predetermined angle with respect to the horizontal plane (the normal of the sheet surface of the daylighting sheet 20). Is inclined. The inclination angle of the side 25b is not particularly limited, but is preferably 0 ° or more and 30 ° or less from the viewpoint of manufacturing.

Further, the side 25b is configured to scatter and reflect the light totally reflected here. Thereby, as will be described later, it is possible to prevent a problem that the interior side can be inquired and seen when the daylighting sheet 20 is looked up from the outside.
Although the specific form for scattering and reflecting light is not specifically limited, For example, you may comprise so that the edge | side 25b may have a micro unevenness | corrugation. The method for forming minute irregularities will be described in detail later.
An example of such an uneven surface is shown in FIG. Thus, the uneven surface is preferably stepped along the inclination of the side 25b. Specifically, it is as follows. The size of the unevenness in the thickness direction (the size indicated by T in FIG. 5) is preferably 1 μm or more and 50 μm or less. If it is smaller than 1 μm, the wavelength is about the wavelength of light, and the effect of total reflection on geometric optics may not be obtained. On the other hand, the size in the thickness direction of the light deflection section 25 is preferably 50 μm or more and 300 μm or less from the viewpoint of processing. At this time, if T is larger than 50 μm, it may not be stepped.
Further, the size of the unevenness in the width direction (the size indicated by S in FIG. 5) is 0.5 μm or more, and more preferably 1.0 μm or more. On the other hand, the size in the width direction is desirably 10 μm or less. If it is 10 μm or more, it may become too close to the width of the light deflection section 25 and may not have an appropriate step shape.

The pitch at which the light deflection units 25 are arranged in parallel is not particularly limited, but is preferably 10 μm or more and 200 μm or less. If the pitch is too narrow, it becomes a fine shape, which makes processing difficult during manufacturing. On the other hand, if the pitch is too wide, the releasability of the material tends to decrease when molding with a mold.
In addition, the size of the outdoor side (the opening side of the concave portion between the light transmission parts 24 on the side opposite to the base material layer 22) in the cross section of the light deflection part 25 is not particularly limited, but may be 5 μm or more and 150 μm or less. preferable. If this width is too narrow, it becomes a fine shape, making processing difficult. On the other hand, if this width is too wide, the releasability of the material tends to decrease when molding with a mold.

  The size of the light deflection unit 25 in the thickness direction (the left-right direction in FIG. 4) is not particularly limited, but is preferably 10 μm or more and 200 μm or less. If this is too small, it may be difficult to process the light deflection section 25 itself. On the other hand, if this is too large, the manufacture of the mold for forming the light deflection section 25 and the releasability of the material from the mold may be reduced, and the productivity may be deteriorated.

6 and 7 show the cross-sectional shape of the light deflection unit according to the modification. FIG. 6A shows an example of the light deflecting unit 25 ′ having a curved shape with the side on the upper side convex downward. In this example, the inclination angle of the tangent line at the outermost part is an angle θ _{a with} respect to the horizontal plane (the normal of the sheet surface of the daylighting sheet 20), and the inclination angle of the tangent line at the innermost part is the horizontal plane (lighting an angle theta _b with respect to the normal) of the seat surface of the seat 20. In this case, the average of θ _a and θ _b is θ _U.
FIG. 6B shows an example of a broken line-shaped light deflecting portion 25 ″ whose upper side is formed by two sides 25 ″ a and 25 ″ b from the outdoor side and is convex downward. is there. In this example, the inclination angle of the side 25 ″ a that is the most outdoor side is an angle θ _{a with} respect to the horizontal plane (the normal of the sheet surface of the daylighting sheet 20), and the inclination angle of the side 25 ″ _b that is the most indoor side. There the angle theta _b with respect to the horizontal plane (normal to the sheet surface of the lighting sheet 20). Also in this case, the average of θ _a and θ _b is θ _U. Here, the example of the light deflection unit including the two sides 25 ″ a and 25 ″ b has been described, but the present invention is not limited thereto, and the light deflection unit may be formed by more sides.

  These light deflecting units as shown in FIGS. 6A and 6B also have the same effect as the light deflecting unit having the shape shown in FIG. Furthermore, according to the shapes shown in FIGS. 6A and 6B, it is possible to suppress the occurrence of rainbow-like unevenness due to wavelength dispersion due to total reflection at the upper side.

  FIG. 7 shows an example of the light deflecting unit 25 ′ in which the opening side (the side facing the outdoor side in this embodiment) of the groove formed between the light transmitting units is recessed. ''. In this case, the adhesive of the adjacent adhesive layer 27 is filled inside the recess. According to this, sunlight can be further deflected in the concave portion to control the light.

Returning to FIG. 3, the description of other configurations will be continued.
The adhesive layer 27 is a layer for adhering the daylighting sheet 20 to the panel 13. The material constituting the adhesive layer 27 is not particularly limited as long as it can adhere the daylighting sheet 20 to the panel 13, and a known pressure-sensitive adhesive, adhesive, photocurable resin, thermosetting resin, or the like is used. it can. As a more specific example, as the adhesive layer 27, for example, an acrylic pressure-sensitive adhesive can be used, and more specifically, a pressure-sensitive adhesive combining an acrylic copolymer and an isocyanate compound can be used. However, the material constituting the adhesive layer 27 is preferably made of a material excellent in translucency and weather resistance due to the properties of the daylighting sheet 20.

  The thickness of the adhesive layer 27 is not particularly limited, but is preferably 10 μm or more and 100 μm or less. If the adhesive layer 27 is too thin, the adhesion between the panel 13 and the daylighting sheet 20 may be reduced. If the adhesive layer 27 is too thick, it becomes difficult to make the thickness of the adhesive layer 27 uniform.

The daylighting device 10 is formed by the daylighting panel 12 including the daylighting sheet 20 described above, and this is arranged in the opening of the building 1 as shown in FIG. Next, the action in this way, scene lighting sheet 20 is disposed, and the preferred values described above angular theta _U, will be described with reference to the main optical path. Examples of optical paths necessary for the explanation are appropriately shown in the drawings shown below. Note that the optical path examples shown in each drawing are conceptual and do not strictly represent the degree of refraction or reflection.

FIG. 8 shows light L _S1 from the sun as an example of one optical path. As can be seen from FIG. 8, L _S1 is applied to the daylighting panel 12 at an elevation angle (angle formed from a horizontal plane) θ _S1 based on the solar altitude at that time. The light L _S1 incident on the daylighting panel 12 travels through the light transmitting portion 24 of the light deflection layer 23 while passing through the daylighting panel 12. In the light transmission part 24, if the refractive index of the light transmission part 24 is N _P , and the outdoor refractive index is N ₀ , the light L _S1 is a sunlight traveling angle θ _P1 represented by the formula (1). move on.

When the sunlight traveling at the sunlight traveling angle θ _P1 reaches the interface between the light transmitting portion 24 and the light deflecting portion 25, the difference in refractive index between the light transmitting portion 24 and the light deflecting portion 25, and the sunlight traveling angle θ _P1. If the relationship is equal to or greater than the total reflection critical angle, total reflection occurs at the interface as shown in FIG. As a result, sunlight is deflected and direct light that causes glare can be suppressed. That is, according to the daylighting sheet 20, at least a part of the sunlight can be deflected by total reflection like the light L _S1 and can be provided indoors without significantly reducing the amount of incident sunlight into the room. And at least a part of direct light (so-called direct sunlight) can be eliminated. Thereby, a bright and comfortable indoor space can be formed.

On the other hand, for example, at night, when the indoor side is brighter than the outdoor side, light as indicated by L _N1 in FIG. 8 is emitted from the indoor side to the outdoor side. This light includes information that can be used to indicate the state of the room, and may be totally reflected at the interface between the light transmitting part and the light deflecting part and be emitted in a form that clearly shows this information outside the room. However, in the present invention, means for scattering light is provided on the lower side 25b of the light deflector 25, so that light containing information that can be used to inspect the inside of the room as shown by light L _N1 in FIG. Scattered and emitted outside the room. Therefore, according to the daylighting sheet 20, with respect to the light reflected at the interface between the light transmission part and the light deflection part, the light from the indoor side loses its clarity and is emitted to the outdoor side. The state where the state can be heard is eliminated.

Further, the daylighting sheet 20 is provided with the light transmission part 24 as described above, and the front and back surfaces of the light deflection layer 23 at the part where the light transmission part 24 is arranged are formed in parallel and smooth. As a result, as shown in FIG. 8, the light L _K1 with the outdoor scenery can enter the room, which means that the outdoor scenery can be visually recognized from the indoor side. Therefore, the daylighting sheet 20 has a structure that makes it easier to visually recognize the scenery outside the room.

In the daylighting sheet 20 as described above, the direction of sunlight to be deflected depends on the sunlight traveling angle θ _P1 that is an angle incident on the interface and θ _U that is the inclination angle of the light deflection unit. Therefore, it is preferable that θ _U is determined so that the totally reflected light finally becomes upward from the horizontal. However, it is possible to define a preferable θ _U from the viewpoint of more effectively totally reflecting sunlight at the interface between the light transmitting portion 24 and the light deflecting portion 25 and deflecting the sunlight so as to be emitted indoors. This will be described in detail below.

For example, θ _U can be set based on the elevation angle θ _SH when the south-high altitude is highest in one year. That is, since the sunlight advancing angle θ _PH in the light transmitting portion when the elevation angle θ _SH is set is expressed by the following equation (2), θ _U can be totally reflected so that the light traveling at this angle θ _PH can be totally reflected. Set.

However, elevation theta _SH is differs by latitude and a predetermined region extending so as to straddle the different latitudes (e.g. country or region, etc.) theta _SH1 to theta _SH2 in (theta _SH1 <theta _SH2), defining a range of theta _U be able to. That is, Formula (3) can be made into the preferable range of (theta) _U.

Here, in Japan, θ _SH in Sapporo is 70.5 °, and θ _SH in Okinawa is 87.5 °. Therefore, θ _U is preferably in the range of the formula (4).

On the other hand, θ _U can be set, for example, based on the elevation angle θ _SL when the south-central altitude is the lowest in a year. That is, since the sunlight traveling angle θ _PL in the light transmitting portion when the elevation angle θ _SL is set is expressed by the following equation (5), θ _U can be totally reflected so that the light traveling at this angle θ _PL can be totally reflected. Set.

However, since the elevation angle theta _LH varies depending latitude, (theta _SL1 <theta _SL2) by theta _SL1 to theta _SL2 in a predetermined region (e.g., country or region etc.) extending so as to straddle the different latitudes, defining a range of theta _U be able to. Here, since θ _U becomes smaller than 0 ° (inclined as opposed to FIG. 4), it becomes difficult to manufacture. From the above, Equation (6) may be a preferred range of theta _U.

Here, in Japan, θ _SL in Okinawa is 40.5 °, and therefore θ _U2 is preferably in the range of equation (7).

  The daylighting sheet 20 may be provided with a configuration for adding another function to any of the above-described layers. For example, an ultraviolet absorber, a heat ray absorber, or a near infrared absorber may be added to provide an ultraviolet ray absorbing function, a heat ray absorbing function, or a near infrared ray absorbing function.

  The near-infrared absorbing function can be improved by adding or applying a near-infrared absorbing agent (near-infrared absorbing dye) to one or more of the above layers. As the near-infrared absorbing dye, it is preferable to use one that absorbs a wavelength region of 800 nm to 1100 nm. The near-infrared transmittance in the wavelength region is preferably 20% or less, and more preferably 10% or less. On the other hand, the near-infrared absorbing dye preferably has a sufficient transmittance in the visible light region, that is, in the wavelength region of 380 nm to 780 nm.

  The ultraviolet absorbing function can be improved by adding or applying an ultraviolet absorber exemplified below to one or more of the above layers. Examples of ultraviolet absorbers include benzotriazole ultraviolet absorbers (TINUVIN P, TINUVIN P FL, TINUVIN 234, TINUVIN 326, TINUVIN 326 FL, TINUVIN 328, TINUVIN 329, TINUVIN 329 FL, all manufactured by BASF Japan Ltd.), and triazine. Ultraviolet absorber (TINUVIN 1577 ED, manufactured by BASF Japan Ltd.), benzophenone ultraviolet absorber (CHIMASSORB 81, CHIMASORB 81 FL, all manufactured by BASF Japan Ltd.), benzoate ultraviolet absorber (TINUVIN 120, BASF Japan Ltd.) Manufactured).

  The heat ray absorbing function can be improved by adding or applying a heat ray absorbent exemplified below to one or more of the above-described layers. Examples of the heat ray absorbent include metal oxide ultrafine particles such as antimony-doped tin oxide (ATO) or tin-doped indium oxide (ITO) and phthalocyanine compounds.

  The daylighting panel 12 described above is manufactured as follows, for example. That is, the daylighting panel 12 can be manufactured by bonding the daylighting sheet 20 to the panel 13. Here, the daylighting sheet 20 can be manufactured as follows, for example.

  The light deflection layer 23 of the daylighting sheet 20 can be formed by a method using a mold roll. Here, the roll mold 30 for forming the light transmission part 24 of the light deflection layer 23 will be described. FIG. 9 is a perspective view schematically showing the appearance of the roll mold 30. FIG. 10 is an enlarged view of a part of the cross section of the annular protrusion 32 and the groove 33 formed on the outer peripheral surface of the roll mold 30 shown in FIG. The cross section is a cross section orthogonal to the direction in which the annular protrusion 32 and the groove 33 extend, and is a cross section in the direction along the rotation axis of the roll mold 30.

  As shown in FIG. 9, the roll mold 30 is a so-called roll-shaped mold having a cylindrical shape, and a plurality of annular protrusions 32 protruding from the outer peripheral surface of the cylindrical roll base 31, and the annular protrusions 32. A groove 33 is formed. Here, the annular protrusion 32 and the groove 33 are provided so as to extend in the circumferential direction of the roll mold 30 and to be further juxtaposed in the width direction (roll rotation axis direction). Further details are as follows.

The roll base 31 has a base serving as a base and a layer to be processed laminated on the outer surface of the base.
The base is a part for securing the rigidity of the roll base 31 and occupies most of the roll base 31. From this point of view, the base is preferably made of an iron-based material for mechanical structure. Further, from the viewpoint of reducing the weight while ensuring the necessary rigidity, the base may have a bottomed cylindrical shape having bottoms at both ends. In addition, a double structure is generally used so that cold water, hot water, steam, or high-temperature oil can be circulated inside the roll base 31 so that the temperature of the surface of the roll mold 30 can be adjusted.
On the other hand, the layer to be processed is a layer laminated so as to cover the outer surface of the substrate. Since the material of the substrate is selected from the viewpoint of structure as described above, it is often difficult to process. Therefore, since it is only necessary to actually process near the surface of the roll base 31, a layer to be processed that is relatively easy to process is provided in the processed part. Therefore, the layer to be processed is preferably a plating layer made of a material that can be easily processed, such as a copper plating layer or a nickel plating layer. The thickness of the layer to be processed is determined by the shape to be processed due to its nature. For example, the thickness of the copper plating layer is not a problem as long as it is equal to or higher than the required shape, but is usually 0.3 mm to 1.0 mm.

  The annular protrusion 32 and the groove 33 have a shape corresponding to a groove-like recess formed between the light transmission part 24 and the adjacent light transmission part 24 provided in the light deflection layer 23. That is, the annular protrusion 32 has a concave shape, and the groove 33 has a light transmitting portion 24 shape. Here, the surface 32 a which is one side surface of the annular protrusion 32 forms the side 25 a of the light deflection unit 25, and the surface 32 b which is the opposite side surface forms the side 25 b of the light deflection unit 25. Accordingly, the surface 32b is provided with unevenness corresponding to the unevenness formed on the side 25b.

  In the roll mold 30 for forming fine irregularities in the light scattering layer 23, the groove 33 and the annular protrusion 32 itself are very fine, and the groove 33 and the annular protrusion 32 are in the circumferential direction of the roll mold 30. And is densely formed so as to be arranged over the entire length of the roll mold 30 in the width direction (roll rotation axis direction). Further, since the roll mold 30 is for molding an optical member, it is necessary to sufficiently ensure the accuracy of the grooves 33 and the annular protrusions 32. Therefore, when manufacturing the roll mold 30, it is necessary to form the annular protrusions 32 and the grooves 33 efficiently for a long time while maintaining accuracy. Hereinafter, a method for manufacturing the roll mold 30 will be described.

A roll base 31 in which a layer to be processed is laminated on a base is prepared, and this is rotated by a roll rotation shaft. First, as a pre-processing for obtaining a reference surface, mirror processing is performed by a predetermined cutting tool (R bite) with a necessary cutting depth and feed. The R bit is a bit having an arcuate tip, and a diamond bit having a radius of curvature of 2 mm to 10 mm is often used. The feed pitch is generally 0.1 mm to 0.2 mm. Here, the diameter of the roll base 31 is not particularly limited, but is preferably 300 mm or more and 500 mm or less.
Thereafter, the groove 33 is formed by a cutting tool while rotating the roll base 31 based on the obtained reference surface. Here, the cutting tool has, for example, the following shape. FIG. 11 shows a schematic view of a cutting tip 40 as an example of the cutting tool used. In FIG. 11, the rake face is represented by reference numeral 41, the front flank face is represented by reference numeral 42, and the lateral flank face is represented by reference numeral 43. 11 (a) is a perspective view, FIG. 11 (b) is a view from the rake face 41 side, FIG. 11 (c) is a view from the front flank face 42 side, and FIG. It is the figure seen from the side.

  The main dimensions of the cutting tip 40 are set so that the shape of the groove 33 can be formed.

Further, the bite angles θ _a1 and θ _a2 , the lateral clearance angle θ _b , and the front clearance angle θ _c shown in FIG. 11 are as follows. Here, the sum of the bite angles θ _a1 and θ _a2 is called an apex angle. The apex angle is an angle determined by the shape of the optical sheet to be manufactured. In FIG. 11 (b), w is the byte tip width. The apex angle and the bite tip width are appropriately changed according to the shape of the groove to be formed.

The lateral clearance angle θ _b is preferably 2 degrees or more and 5 degrees or less. By the lateral clearance angle theta _b above 2 degrees, improved sharpness of the cutting tip 40, since the load on the cutting tip is reduced, it is possible to reduce wear, improved precision in one cutting chip can do. That is, it is possible to increase the number of cuttings by increasing the depth of the groove 33 or decreasing the pitch. Therefore, the roll die of the optical sheet can be manufactured without replacing the cutting tip or suppressing the number of replacements. That is, it is possible to improve the efficiency and accuracy of manufacturing the roll mold 30 and to manufacture the uneven shape of the light deflection layer 23 of the daylighting sheet 20 that is the final product with high accuracy. Further, when the lateral clearance angle theta _b larger than 5 degrees, it is necessary to increase also front clearance angle, the strength of the cutting tip 40 emerges be deteriorated.
Front clearance angle theta _c is often below the normal 5 degrees 20 degrees. If the angle is less than 5 degrees, the cutting performance tends to be deteriorated as with the side clearance angle. On the other hand, if it is greater than 20 degrees, the cutting tip tip is not rigid enough to cause chipping or chipping.

  The material of the cutting tip 40 can be appropriately selected depending on the material of the layer to be processed, the processing shape, and the like. Examples thereof include cemented carbide, CBN (cubic boron nitride), diamond and the like. Among these, diamond is preferable from the viewpoint of obtaining high accuracy. There are natural and synthetic diamonds, but there is no particular limitation.

  The rotational speed of the roll base 31 at the time of cutting is not particularly limited, but is preferably 300 rpm or more and 600 rpm or less. Although depending on the diameter of the roll base 31, for example, when the diameter is 400 mm, if it is less than 300 rpm, the cutting speed is slow, so that the burden on the cutting tip becomes large and it may not be possible to process with high accuracy. 600 rpm is approximately the maximum turning speed of the lathe. When the rotation speed of the roll base 31 is increased, the roll base tends to be shaken. From this viewpoint, about 400 rpm is preferable.

  The groove 33 and the annular protrusion 32 are formed as follows using the cutting tip 40 described above. 12, 13, and 14 are schematic diagrams. Cutting is advanced in the order of FIG. 12A, FIG. 12B, FIG. 13A, FIG. 13B, and FIG.

As shown in FIG. 12A, so-called cutting is performed from the outer peripheral surface of the roll base 31 toward the axial direction of the rotation axis of the roll base 31 by the cutting tip 40. At this time, the cutting direction is an oblique direction that proceeds in the feed direction (left direction in the drawing) while moving in the axial direction of the rotation axis of the roll base 31. More specifically, as indicated by XI in FIG. 12A, the cutting tip 40 has the same angle as the bite angle θ _{a1 that} is on the side opposite to the feed direction (right direction on the paper) during cutting. And cutting in the direction of the axis of the rotation shaft. And it cuts to the position of FIG.12 (b), and the one groove | channel 33 is formed.

  By making such a diagonal cut, this surface can be microscopically exaggerated, and the surface 32b can be formed stepwise as shown in FIG. It becomes possible. As described above, this forms minute irregularities on the side 25b of the light deflection unit 25.

  Further, by making such an oblique cut, the force from the cutting tip 40 that tries to tilt the annular protrusion 32 being formed in the direction indicated by E in FIG. It can suppress falling down so that it may bend in the direction of E. In particular, as the cutting progresses, the cutting force of the cutting tip 40 decreases, and the force applied to the annular protrusion 32 tends to increase. On the other hand, since it is possible to suppress the force to fall down from the start part to the end part of the cutting, it is possible to suppress the groove shape from being different depending on the part of the cutting roll and to improve the shape stability. it can.

Next, from the state shown in FIG. 12B, the cutting tip 40 is retracted from the groove 33 in the radial direction of the roll base 31. And it feeds by the half pitch of the pitch of the groove | channel 33, and cuts to the radial direction of the roll base 31 to the outer peripheral part position of the cyclic | annular protrusion 32 as shown to Fig.13 (a). Thereby, the outer peripheral part of the annular protrusion 32 is formed.
Thereafter, the cutting tip 40 is retracted in the radial direction of the roll base 31, and the cutting tip 30 is sent to cut the next groove 33. As shown in FIG. 13B, the feed amount r (mm) at this time takes into account the amount of cut in the oblique direction from the half pitch (p / 2) of the pitch p (mm) of the groove 33. The amount is obtained by subtracting the amount s (mm). Here, the amount s (mm) to be subtracted is t (mm) when the distance between the bottom surface of the groove 33 and the position where the cutting tip 40 starts moving for cutting is t (mm).
s = t · tan (θ _a1 )
It is represented by Therefore, the feed amount r (mm) is
r = p / 2− (t · tan (θ _a1 ))
It becomes.
13A and 13B, the grooves 33 and the annular protrusions 32 are formed as shown in FIG.

  Here, the cutting speed is preferably 2 (μm / rotation) or more and 5 (μm / rotation) or less. Furthermore, when the cutting tip (cutting tool) reaches the cutting depth, it is preferable that the cutting tip 40 is retracted after the roll base 31 is rotated one or more times in the same posture. As a result, a predetermined cutting depth is obtained over the entire circumference of the roll base 31 in the circumferential direction. If the cutting tip 40 is retracted in less than one rotation, there may be a portion that does not reach the predetermined cutting depth partially in the circumferential direction, and the appearance defect and the optical performance may vary.

  As described above, the annular protrusion 32 and the groove 33 are formed so as to extend in the circumferential direction of the roll base 31 and to be arranged in parallel over the entire length of the roll base 31 in the rotation axis direction (width direction). In the present manufacturing method, as described above, the cutting direction is the direction approaching the rotation axis of the roll base 31 including the feeding direction, and the angle is cut obliquely when viewed macroscopically according to the bite angle. Accordingly, microscopic unevenness can be formed on the surface 32b of the protrusion 32 microscopically. As a result, an uneven light scattering surface is formed on the lower surface of the light deflector 25 to which this surface has been transferred.

  After the annular protrusions 32 and the grooves 33 are formed by the above cutting, the roll metal is used in order to prevent the surface of the roll metal from being corroded or to improve the releasability of the light transmitting portion constituting composition described later. The mold surface is preferably plated with chromium or the like.

  Next, a method for producing the light deflection layer 23 using the roll mold 30 will be described. FIG. 16 shows a schematic diagram. First, the light transmission part 24 is formed on the base material layer 22. That is, as can be seen from FIG. 16, the base material 22 ′ to be the base material layer 22 is inserted between the roll mold 30 and the nip roll 50 disposed to face the roll mold 30. At this time, the roll mold 30 and the nip roll 50 are rotated while supplying the composition constituting the light transmitting portion between the base material 22 ′ and the roll mold 30 as indicated by the arrow XVa, and the sheet is moved to the arrow XVb. Send in the direction of. As a result, the groove 33 formed on the surface of the roll mold 30 is filled with the composition constituting the light transmission portion, and the composition conforms to the surface shape of the roll mold 30.

  Here, as a composition which comprises a light transmissive part, the photocurable resin composition which mix | blended the reactive dilution monomer (M1) and the photoinitiator (S1) with the photocurable prepolymer (P1), for example. Is preferably used.

  Examples of the photocurable prepolymer (P1) include epoxy acrylate-based, urethane acrylate-based, polyether acrylate-based, polyester acrylate-based, and polythiol-based prepolymers.

  Examples of the reactive dilution monomer (M1) include vinyl pyrrolidone, 2-ethylhexyl acrylate, β-hydroxy acrylate, and tetrahydrofurfuryl acrylate.

  Examples of the photopolymerization initiator (S1) include hydroxybenzoyl compounds (2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin alkyl ether, etc.), benzoyl Formate compounds (such as methylbenzoylformate), thioxanthone compounds (such as isopropylthioxanthone), benzophenones (such as benzophenone), phosphate compounds (1,3,5-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-) Trimethylbenzoyl) -phenylphosphine oxide and the like, and benzyldimethyl ketal and the like. Among these, the irradiation device for curing the photocurable resin composition and the curability of the photocurable resin composition can be arbitrarily selected. From the viewpoint of preventing coloring of the light transmitting portion 24, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone and bis (2,4,6-trimethylbenzoyl) are preferable. ) -Phenylphosphine oxide.

  The amount of the photopolymerization initiator (S1) contained in the photocurable resin composition is based on the total amount of the composition constituting the light transmission part (100 mass) from the viewpoint of curability and cost of the photocurable resin composition. %) Is preferably 0.5% by mass or more and 5.0% by mass or less. Generally, the photoinitiator is at least partially soluble (eg, at the processing temperature of the resin) and is substantially colorless after polymerization. The photopolymerization initiator may be colored (for example, colored yellow), provided that the composition that constitutes the light transmission part is cured to form a light transmission part and is substantially colorless. To do.

  These photocurable prepolymer (P1), reactive diluent monomer (M1) and photopolymerization initiator (S1) can be used alone or in combination of two or more.

  As shown by the arrow XVc, the light irradiating device (not shown) from the base material 22 'side with respect to the composition constituting the light transmitting portion sandwiched between the roll mold 30 and the base material 22' and filled therein. Irradiate light. Thereby, a light transmissive part composition can be hardened and the shape can be fixed. And the base material layer 22 and the shape | molded light transmission part 24 are released from the roll metal mold | die 30 with a release roll, sending a sheet | seat like arrow XVb. Thereby, the intermediate sheet E in which the light transmission part 24 is laminated on the base material layer 22 is obtained.

  Next, the composition which comprises the light deflection | deviation part 25 is supplied excessively to the recessed part between the light transmissive parts 24 with respect to the intermediate sheet E, and an excess part is scraped off with a doctor blade. As a result, the composition constituting the light deflection unit can be pushed into the recesses between the light transmission parts 24 and filled, and the excess composition can be removed. The light deflection section 25 can be formed by curing the composition filled in this manner by an appropriate method. In this manner, the light deflection layer 23 can be formed on the base material layer 22.

  An adhesive is laminated on the formed light scattering layer 23 to form an adhesive layer 27, and the hard coat layer 21 is attached to the base material layer 22 with an adhesive or the like. Thereby, the daylighting sheet 20 is obtained.

  FIG. 17 is a diagram for explaining the second embodiment and corresponds to FIG. In the second embodiment, the daylighting sheet 120 having the light deflection layer 123 to which the light deflection unit 125 is applied instead of the light deflection unit 25 is formed. The daylighting sheet 120 is affixed to the panel 13 to become the daylighting panel 112. Therefore, the light deflecting unit 125 is applied to the daylighting sheet 120 instead of the light deflecting unit 25, and the other configuration is the same as that of the daylighting sheet 20. Therefore, the light deflecting unit 125 will be described here, and the other components have the same reference numerals. The description is omitted.

In addition to the form of the light deflection unit 25 described above, the light deflection unit 125 is filled with a material for scattering and reflecting or transmitting light. The material for scattering the light is not particularly limited, and examples of the scattering reflection include a curable resin mixed with a light scattering agent such as a white pigment or a silver pigment. Examples of the white pigment include metal oxides such as titanium oxide, titanium dioxide, magnesium oxide, and zinc oxide. As a silver pigment, metals, such as aluminum and chromium, are mentioned, for example. Thereby, light can be efficiently scattered and reflected. The curable resin may be the same as the material constituting the light transmission part 24.
On the other hand, regarding the configuration for scattering reflection and scattering transmission, the light deflection unit 125 can be formed of a material in which a transparent binder resin and a transparent light scattering agent having a refractive index different from that of the binder resin are mixed. . As the transparent binder resin, the same resin as the light transmitting portion 24 can be used. On the other hand, examples of the transparent light scattering agent include crosslinked particles obtained by polymerizing monomers mainly composed of (meth) acrylic acid ester and styrene. Specific examples of the crosslinked particles include Gantzpearl (registered trademark) manufactured by Aika Industry Co., Ltd. The cross-linked particles can be controlled in refractive index by changing the mixing ratio of acrylic acid ester and styrene. For example, the refractive index can be made about 1.49 by increasing the acrylic ratio, and the refractive index can be made about 1.59 by increasing the styrene ratio. Further, urethane cross-linked particles can be used as the light scattering agent. Specific examples of the urethane cross-linked particles include Art Pearl (registered trademark) manufactured by Negami Kogyo Co., Ltd. The light scattering agent can also be made into hollow particles.

In the daylighting sheet 120 having such a light deflection unit 125, light can be guided like sunlight L _S3 in addition to the optical paths such as L _S1 and L _S2 described above. FIG. 17 shows the optical path of L _S3 .
As can be seen from FIG. 17, the light L _S3 is applied to the daylighting panel 112 at an elevation angle (angle formed from a horizontal plane) θ _S3 based on the solar altitude at that time. The light L _S3 incident on the daylighting panel 112 travels through the light transmitting portion 24 of the light deflection layer 123 while passing through the daylighting panel 112. In the light transmission part 24, if the refractive index of the light transmission part 24 is N _P , and the outdoor refractive index is N ₀ , the light L _S3 is at the sunlight advancing angle θ _P3 expressed by the equation (8). move on.

When sunlight traveling at the sunlight traveling angle θ _P3 reaches the interface between the light transmitting portion 24 and the light deflecting portion 125, the difference in refractive index between the light transmitting portion 24 and the light deflecting portion 125, and the sunlight traveling angle θ _If the relationship of _P3 is equal to or smaller than the total reflection critical angle, it proceeds beyond the interface and into the light deflector 125 as shown in FIG. Here, since the light deflecting unit 125 can scatter and emit the light to the indoor side, it is possible to suppress direct light that causes sunlight to scatter and cause glare.

  Thus, in the daylighting sheet 120, the light that has entered the light deflection unit without being totally reflected depending on the conditions of the incident light can be scattered and not emitted directly, but can be emitted indoors. Other effects are the same as those of the daylighting sheet 20.

  In the conventional technology, there is a case in which sunlight does not diffuse and there is a lot of light that reaches the room directly (direct light), and there is a problem that a person in the room feels glare. As a result, even if the room becomes brighter, curtains and blinds are used to prevent glare and the room becomes dark. According to the present invention, this can be suppressed, and glare can be prevented without darkening the room as in the prior art.

DESCRIPTION OF SYMBOLS 1 Building 10 Daylighting device 11 Frame 12 Daylighting panel 13 Panel 20 Daylighting sheet 21 Hard coat layer 22 Base material layer 23 Light deflection layer 24 Light transmission part 25 Light deflection part 27 Adhesion layer

Claims (5)

It is a daylighting sheet that is in the form of a sheet placed in the building opening so that the sheet surface is vertical,
A sheet-like base material layer having translucency;
A light deflection layer formed on one surface of the base material layer for deflecting light,
The light deflection layer is
A light transmitting portion that transmits light arranged in a plurality along one surface of the base material layer;
A light deflecting portion disposed between the adjacent light transmitting portions and filled with a material having a refractive index lower than that of the light transmitting portion, and
In the posture in which the daylighting sheet is arranged in the opening of the building, the light deflection unit has a polygonal line shape or a curved line shape so that the upper side of the daylighting sheet is convex in the thickness direction cross section. , and the its the whole become the sides the bottom manner has a small step-like uneven shape together with a straight line, lighting sheet. 2. The daylighting sheet according to claim 1, wherein the minute stepped irregularities have a size of 1 μm to 50 μm in the thickness direction and 0.5 μm to 10 μm in the sheet surface direction .   The daylighting sheet according to claim 1 or 2, wherein the light deflection unit contains a material that scatters light. A plate-like panel having translucency;
The daylighting sheet according to any one of claims 1 to 3, which is affixed to one surface of the panel;
And a frame arranged to surround at least the periphery of the panel.   A building in which the daylighting device according to claim 4 is installed in an opening formed in a wall.

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