JP6186715B2 - Daylighting sheet, daylighting device, and building - Google Patents

Description

  The present invention relates to a daylighting sheet, a daylighting device, and a building including the daylighting device for taking 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. However, on the other hand, 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 for controlling the direct sunlight and adopting the indoor side in a more comfortable manner have been proposed.

  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. That is, when the light control sheet is applied to a window of a building or the like, it is difficult to efficiently incorporate the outside light into the room because a part of the outside light is absorbed by the light shielding portion group.
In addition, the technique disclosed in Patent Document 2 can control light incident from the outside, but the image is refracted when viewed from the inside of the room, so there is a lack of clarity for viewing the outside scenery. there were. 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 addition, the technology so far has mainly considered the control of light incident into the room from diagonally upward to diagonally downward, and examined in detail the control of light incident into the room from diagonally downward to diagonally upward. Was not. For example, when a light shelf or the like is used, light may enter the room from obliquely downward to obliquely upward.

  Therefore, in view of the above-described problems, the present invention suppresses direct sunlight (direct light) and can control light incident from obliquely downward to obliquely upward so that the light can be efficiently collected. It is an object of the present invention to provide a daylighting sheet that can also be used. Moreover, the lighting apparatus and building using this are provided.

  The present invention will be described below.

The invention according to claim 1 is a daylighting sheet in the form of a sheet disposed in a building opening so that the sheet surface is vertical, a sheet-like base material layer having translucency, and a base material layer A light scattering layer that scatters light and is arranged side by side along one surface of the base material layer, and adjacent to a light transmission portion that transmits light. A light scattering portion disposed between the matching light transmission portions, and a light scattering portion in a vertical section in the thickness direction of the light scattering layer in a posture in which the daylighting sheet is disposed in the building opening. has an interface with the upper and the light transmitting portion below the interface downward, Ri indoor side end portion and the elevated position near from the outdoor-side end portion, and the indoor-side end portion and the outdoor-side end portion of the upper surface and _U an angle of 90 ° the smaller θ of line horizontal plane and the angle connecting the indoor-side end portion of the interface between the lower and the outdoor-side end portion If line and the angle of 90 ° the smaller theta _D of the horizontal plane and the angle connecting, with θ _D> θ _U is satisfied, the theta _D is 0 ° or more than 30 °, a lighting sheet.

According to a second aspect of the present invention, in the daylighting sheet according to the first aspect, in the vertical section in the thickness direction of the light scattering layer in a posture in which the daylighting sheet is disposed in the opening of the building, the light scattering portion is in the vertical direction. Of the two adjacent light scattering parts, the indoor side end of the upper interface of the light scattering part disposed below, and the lower interface of the light scattering part adjacently disposed above Of the angle formed by the prospective line connecting the outdoor end with the horizontal plane, the angle smaller than 90 ° is the prospective angle θ ₁ , and the lower interface of the light scattering part disposed above the adjacent two light scattering parts The angle that is smaller than 90 ° out of the angle formed by the prospective line connecting the indoor-side end portion and the outdoor-side end portion of the upper interface of the light scattering portion adjacently disposed below and the horizontal plane is the prospective angle θ. ₂ , θ ₂ > θ ₁ is established.

The invention according to claim 3 is the daylighting sheet according to claim 1 or 2 , wherein the light scattering portion is a vertical section in the thickness direction of the light scattering layer in a posture in which the daylighting sheet is disposed in the building opening. It is arranged in parallel in the vertical direction, and the indoor side end portion of the interface above the light scattering portion disposed below among the two adjacent light scattering portions, and below the light scattering portion disposed adjacently above Of the angle formed by the prospective line connecting the outdoor end of the interface with the horizontal plane, the angle smaller than 90 ° is the prospective angle θ ₁ , and the elevation angle when the sun is at the highest altitude in the south is θ _SH . When the refractive index of the material constituting the transmission part is N _P and the refractive index in air is N ₀ , the following equation (1) is established.

In the invention according to claim 4 , in the daylighting sheet according to claim 3 , when the elevation angle when the sun's south-intermediate altitude is the lowest in one year is θ _SL , the following equation (2) is established.

Invention of Claim 5 is a lighting device with which the opening part of a building is equipped, Comprising: The plate-shaped panel which has translucency, and any one of Claims 1 thru | or 4 stuck on one surface of a panel A daylighting apparatus comprising: the daylighting sheet described above; and a frame disposed so as to surround at least the periphery of the panel.

According to a sixth aspect of the present invention, in the daylighting device of the fifth aspect , a light shelf is further provided on the outdoor side of the daylighting sheet and the panel.

The invention of claim 7 is a building lighting device according to claim 5 or 6 in the opening is installed.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing the direct sunlight (direct light) and controlling the light which injects from diagonally downward toward diagonally upward, it can light efficiently and it also becomes possible to look at the outdoor side from the indoor side. .

It is a figure explaining 1st embodiment 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. 4 is a diagram for explaining a form of a light scattering layer 23. FIG. 5A shows an example in which the legs of the light scattering part are convex, FIG. 5B shows an example in which the legs of the light scattering part are concave, and FIG. 5C shows the legs of the light scattering part. FIG. 5D shows an example of a polygonal line, FIG. 5D shows an example where the bottom of the light scattering part is concave, and FIG. 5E shows an example where the light scattering part has a triangular cross section. It is one figure explaining the effect of the daylighting sheet. It is another figure explaining the effect of the daylighting sheet. It is another figure explaining the effect of the daylighting sheet. It is a figure explaining one aspect which determines prospective angle (theta) _1. FIG. It is a figure explaining the other aspect which determines prospective angle (theta) _1. FIG. It is a figure explaining the layer structure of the lighting panel 12 'which is a modification of a lighting sheet. It is a figure explaining the structure of the lighting panel of Example 1. FIG. It is a figure explaining the structure of the lighting panel of Example 2. FIG. It is a figure explaining the evaluation method of a lighting panel.

  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, dimensions and shapes 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 the first embodiment, and is an external perspective view of a building 1 provided with a daylighting sheet 20 (see FIG. 3). Building 1 is a so-called office building. The outer wall facing the south side of the building 1 is provided with a plurality of openings that communicate indoors and outdoors. The daylighting device 10 including the daylighting sheet 20 is disposed in the opening.
FIG. 2 is a front view of one daylighting apparatus 10 viewed from the outdoor side. As shown in FIG. 2, the daylighting device 10 is installed substantially horizontally on the frame 11, the daylighting panel 12 disposed within the frame 11, and the outdoor side of the daylighting panel 12 (side on which external light is incident). And a light shelf 30. The daylighting device 10 is configured as a so-called window, and the daylighting device 10 is arranged in the opening of the building 1 as described 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 panel 13. The daylighting sheet 20 includes a hard coat layer 21, a base material layer 22, a light scattering layer 23, and an adhesive layer 26 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. From the viewpoint of resistance to scratches and surface contamination, the hard coat layer 21 is preferably formed as a cured resin layer formed by curing a curable resin.

  As the resin constituting the hard coat layer 21, for example, an ionizing radiation curable resin, other known curable resins, or the like may be appropriately employed depending on the required performance. Examples of the ionizing radiation curable resin include acrylate-based, oxetane-based, and silicone-based resins. Examples of the acrylate ionizing radiation curable resin include monofunctional (meth) acrylate monomers, bifunctional (meth) acrylate monomers, (meth) acrylate monomers such as trifunctional or higher (meth) acrylate monomers, urethane ( It consists of (meth) acrylate ester oligomers such as (meth) acrylate, epoxy (meth) acrylate, and polyester (meth) acrylate, or (meth) acrylate 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 a material 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 in 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 serving as a base material for forming the light scattering layer 23. Therefore, the base material layer 22 has a light transmitting property and supports the light scattering layer 23 so as to prevent deformation. From this point of view, specific examples of the material constituting the base material layer 22 include a transparent resin mainly composed of one or more of acrylic, styrene, polycarbonate, polyethylene terephthalate, acrylonitrile, and the like, epoxy acrylate, and urethane acrylate. Reactive resins (ionizing radiation curable resins, etc.).

  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. It becomes easy to process by making the thickness of the base material layer 22 into the said range. For example, it becomes easy to prevent wrinkles by increasing the thickness of the base material layer 22 to some extent. Moreover, by making the base material layer 22 thin to some extent, winding of the sheet including the base material layer 22 is facilitated in an intermediate process among the steps of manufacturing the daylighting sheet 20.

The light scattering layer 23 has a light transmission part 24 and a light scattering part 25. The light transmission part 24 has the cross section shown in FIG. 3 and is arranged so as to extend in one direction along the surface of the base material layer 22 (horizontal direction in the posture arranged in the building 1). A plurality of light transmission portions 24 are arranged at a predetermined interval in a direction different from the one direction along the surface of the layer 22 (a vertical direction in a 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 scattering portion 25 is disposed between the adjacent light transmission portions 24.

FIG. 4 shows an enlarged view of a part of the light scattering 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 26 side) of the light scattering layer 23 where the light transmitting portion 24 is disposed. Are formed parallel and smooth. This makes it easier to see the outdoor scenery through the daylighting sheet 20 as will be described later. Preferably, the light transmission unit 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 the present embodiment, the light transmitting portion 24 has a substantially trapezoidal cross section between the two light scattering portions 25 in the cross section shown in FIGS. 3 and 4, and has a short upper bottom on the outdoor side and a long lower bottom on the indoor side. The sides constituting the interface with the light scattering portion 25 are leg portions.

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.

  The light scattering part 25 is a part formed between two adjacent light transmission parts 24. That is, 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 recess having a substantially trapezoidal cross section is formed between the light transmission parts 24. The concave portion in the present embodiment is a groove having a cross section having a long lower bottom on the outdoor side (panel 13 side) and a short upper bottom on the indoor side (base material layer 22 side), and a material constituting the light scattering portion 25 here. The light scattering portion 25 is formed by being filled. Accordingly, the light scattering portion 25 has a cross section based on the recess.

  The light scattering unit 25 is a layer configured to be able to scatter and reflect the light irradiated here. Therefore, the light scattering portion 25 is filled with a material for scattering and reflecting light. The material for scattering light is not particularly limited, but examples include a material obtained by mixing a transparent binder resin 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. Further, the binder resin can be the same as the material constituting the light transmission part 24.

  Further, the light scattering portion 25 may be made of a material obtained by mixing a transparent binder resin and a transparent scattering agent having a refractive index different from that of the binder resin. 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 scattering agent include cross-linked 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 scattering agent. Specific examples of the urethane cross-linked particles include Art Pearl (registered trademark) manufactured by Negami Kogyo Co., Ltd. The scattering agent can also be hollow particles.

  The refractive index of the binder resin used for the light scattering portion 25 is not particularly limited, but is preferably in the range of 1.56 to 1.49 from the viewpoint of versatility. The refractive index of the binder resin used for the light scattering portion 25 is preferably lower than the refractive index of the material constituting the light transmission portion 24. As a result, as described later, at the interface between the light transmission part 24 and the light scattering part 25, it is possible to totally reflect and deflect light incident on the interface at an angle larger than the total reflection critical angle. The deflected light changes its direction, and can be eliminated from direct light that gives glare, for example, by being irradiated on the ceiling. However, the present invention is not limited to this, and the refractive indexes of the light scattering portion 25 and the light transmitting portion 24 may be the same or close to each other.

  Furthermore, in this embodiment, the light scattering portion 25 has the following shape. This will be described with reference to FIG.

Between the two light scattering portions 25, the light transmission portion 24 is disposed as described above. Therefore, as shown by IVa and IVb in FIG. 4, lines corresponding to the diagonal lines of the light transmission part 24 can be defined. More specifically, in the vertical cross section in the thickness direction of the light scattering layer 23 in a posture in which the daylighting sheet 20 is disposed in the building opening, the light scattering portions 25 are juxtaposed in the vertical direction, and two adjacent light scattering portions are scattered. The indoor side end portion of the interface with the light transmitting portion 24 above the light scattering portion 25 disposed below the light scattering portion 25 and the light transmitting portion 24 below the light scattering portion 25 disposed adjacently and above A line connecting the outdoor side end portion of the interface is a prospective line IVa. Then, the angle that is smaller than 90 ° out of the angles that the line of sight IVa makes with the horizontal plane is defined as a prospective angle θ ₁ . Moreover, the indoor side edge part of the interface with the light transmission part 24 below the light scattering part 25 arranged above the light scattering part 25 adjacent to the two adjacent light scattering parts 25, and the light scattering part 25 arranged adjacently below. A line connecting the outdoor side end portion of the interface with the light transmission portion 24 above is defined as a prospective line IVb. And the angle | corner smaller than 90 degrees among the angles which this prospective line IVb makes with a horizontal surface is made into prospective angle (theta) ₂ . In the present embodiment, it is preferable that the θ ₁ and θ ₂ take predetermined values, and it is preferable that θ ₂ > θ ₁ is satisfied. Since the specific description of θ ₂ and θ ₁ relates to the optical path of sunlight, it will be described later along with an example of the optical path.

  Further, as can be seen from FIG. 4, in the vertical cross section in the thickness direction of the light scattering layer 23 in a posture in which the daylighting sheet 20 is disposed in the building opening, one light scattering portion 25 and the light scattering portion 25 are sandwiched. The lower interface of the interfaces with the light transmission part 24 is at a position where the indoor side end is higher than the outdoor side end. That is, in the vertical cross section in the thickness direction of the light scattering layer 23 in a posture in which the daylighting sheet 20 is disposed in the building opening, the light scattering unit 25 has an interface with the light transmission unit 24 above and below, Is located at a position where the indoor side end is higher than the outdoor side end. Thereby, as will be described later, the light reflected on the upper surface of the light shelf 30 and incident on the daylighting sheet 20 from obliquely downward to obliquely upward can be transmitted without reaching the light scattering portion 25 as much as possible.

Further, as can be seen from FIG. 4, the line connecting the indoor side end and the outdoor side end of the upper interface among the interfaces of one light scattering part 25 and the light transmission part 24 sandwiching the light scattering part 25 is It is inclined with θ _U (an angle smaller than 90 ° out of the angle formed with the horizontal plane) with respect to the horizontal plane (the normal of the sheet surface of the daylighting sheet 20), and one light scattering portion 25 and the light scattering The line connecting the indoor side end and the outdoor side end of the lower interface among the interfaces with the light transmitting part 24 sandwiching the part 25 is θ _D (normal to the sheet surface of the daylighting sheet 20). It is inclined with an angle smaller than 90 ° out of the angle formed with the horizontal plane.

As will be described later, θ _U is determined from the viewpoint of totally reflecting external light incident on the daylighting sheet 20 from obliquely upward to obliquely downward at the interface between the light scattering portion 25 and the light transmitting portion 24 and deflecting it upward as much as possible. It is preferred that That is, θ _U is preferably small to some extent, and θ _U can be set to 0 °. On the other hand, θ _D is preferably determined from the viewpoint of transmitting light reflected on the upper surface of the light shelf 30 and incident on the daylighting sheet 20 from obliquely downward to obliquely upward so as not to reach the light scattering portion 25 as much as possible. . That, theta _D is preferably large to some extent. Therefore, the light reflected from the upper surface of the light shelf 30 and incident on the daylighting sheet 20 from obliquely downward to obliquely upward is transmitted so as not to reach the light scattering portion 25 as much as possible, and the light is obliquely inclined upward to obliquely downward. From the viewpoint of totally reflecting light incident on the sheet 20 at the interface between the light scattering portion 25 and the light transmitting portion 24 and deflecting it as much as possible, it is preferable that θ _D > θ _U is satisfied. However, θ _D and θ _U are each preferably set to 0 ° or more and 30 ° or less from the viewpoint of easy manufacture of the light scattering layer 23.

The pitch at which the light scattering portions 25 are arranged in parallel is preferably in a range where the above θ ₁ and θ ₂ satisfy a predetermined value, and is preferably 20 μm or more and 200 μm or less, for example. By setting the pitch of the light scattering portion 25 to be equal to or more than the lower limit of the above range, the light scattering portion 25 does not become too fine and the light scattering layer 23 is easily formed. On the other hand, by setting the pitch of the light scattering portions 25 to be equal to or less than the upper limit of the above range, it is possible to suppress the release property of the light transmitting portion 24 from being lowered when the light transmitting portion 24 is molded with a mold as described later. it can.

  In addition, the size of the outdoor side (the opening side of the concave portion between the light transmitting portions on the side opposite to the base material layer 22) in the cross section of the light scattering portion 25 is not particularly limited, but is preferably 5 μm or more and 150 μm or less. . By setting the width to be equal to or greater than the lower limit of the above range, the light scattering portion 25 does not become too fine and the light scattering layer 23 is easily formed. On the other hand, by setting the width to be equal to or less than the upper limit of the above range, it is possible to suppress the release property of the light transmitting portion 24 from being lowered when the light transmitting portion 24 is molded with a mold as described later.

The size in the thickness direction of the light scattering portion 25 (the left-right direction in FIG. 4) is preferably in a range where the above θ ₁ and θ ₂ satisfy a predetermined value, for example, 20 μm or more and 200 μm or less. preferable. By setting the size of the light scattering portion 25 in the thickness direction to be equal to or greater than the lower limit of the above range, the light scattering portion 25 does not become too fine, and the light scattering layer 23 is easily formed. On the other hand, by making the size of the light scattering portion 25 in the thickness direction not more than the upper limit of the above range, the manufacture of the mold used when forming the light transmitting portion 24 as described later, and the light in the mold is used. When the transmissive part 24 is formed, it becomes easy to release the light transmissive part 24, and the productivity of the light scattering layer 23 is easily improved.

In the present embodiment, an example in which the light scattering portion 25 has a trapezoidal cross section has been described. However, the present invention is not limited thereto, and the side corresponding to the trapezoidal leg portion may be a curved line or a polygonal line. FIG. 5 shows the cross-sectional shape of the light scattering portion of each example.
5A shows an example of a light scattering portion 25a having a curved trapezoidal leg, FIG. 5B shows an example of a light scattering portion 25b having a concave trapezoidal leg, and FIG. ) Is an example of the light scattering portion 25c in which the trapezoidal leg portion is a polygonal line.
FIG. 5D shows a light scattering portion 25d of an example in which the lower bottom side (opening side of the groove formed between the light transmission portions) of the trapezoidal cross section of the light scattering portion is formed in a concave shape. In this case, the adhesive inside the adjacent adhesive layer 26 is filled in the concave shape.
FIG. 5E shows an example of the light scattering portion 25e in which the cross-sectional shape of the light scattering portion is a triangle. As described above, the light scattering portion may have a triangular cross section.

  Further, from the viewpoint of facilitating the scattering and reflection of light at the interface between the light scattering portion 25 and the light transmission portion 24, the surface between the light scattering portion 25 and the light transmission portion 24 is formed with numerous minute irregularities. It is good also as a mat surface.

  Returning to FIG. 3, the description of other configurations will be continued.

  The adhesive layer 26 is a layer for adhering the daylighting sheet 20 to the panel 13. The material constituting the adhesive layer 26 is not particularly limited as long as the daylighting sheet 20 can be adhered to the panel 13. That is, examples of the material constituting the adhesive layer 26 include known pressure-sensitive adhesives, adhesives, photocurable resins, and thermosetting resins. More specific examples of the material constituting the adhesive layer 26 include acrylic pressure-sensitive adhesives, and more specifically, pressure-sensitive adhesives that combine acrylic copolymers and isocyanate compounds. it can. However, the material constituting the adhesive layer 26 is preferably a material excellent in translucency and weather resistance due to the properties of the daylighting sheet 20.

  The thickness of the adhesive layer 26 is not particularly limited, but is preferably 10 μm or more and 100 μm or less. By setting the thickness of the adhesive layer 26 to 10 μm or more, it becomes easy to improve the adhesion between the panel 13 and the daylighting sheet 20. Further, by setting the thickness of the adhesive layer 26 to 100 μm or less, it becomes easy to make the thickness of the adhesive layer 26 uniform.

  Next, the light shelf 30 will be described. As the light shelf 30, a conventionally known light shelf can be used without any particular limitation. The light shelf is a wall provided on the outside of the window, and the light reflected from the upper surface of the wall while suppressing direct sunlight from being emitted to the window below the window. Is a member for introducing soft diffused light into the room by taking it into the room and reflecting the light to the ceiling of the room. The light shelf 30 can be configured by using a plate material having a metallic gloss surface such as aluminum or stainless steel.

The daylighting device 10 includes the daylighting panel 12 including the daylighting sheet 20 described above and the light shelf 30, and is arranged in the opening of the building 1 as shown in FIG. 1. Next, the action in the scene where the daylighting apparatus 10 is arranged in this way and the preferable conditions of the above-described prospective angles θ ₁ and θ ₂ will be described based on main optical paths. 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. 6 shows light L _S1 from the sun as an example of one optical path. As can be seen from FIG. 6, L _S1 is reflected by the upper surface of the light shelf 30 and enters the lighting panel 12 at a predetermined angle (angle formed with respect to the horizontal plane) θ _S1 obliquely upward. The light L _S1 incident on the daylighting panel 12 travels through the light transmitting portion 24 of the light scattering layer 23 while passing through the daylighting panel 12. Assuming that the refractive index of the light transmission part 24 is N _P and the outdoor refractive index is N ₀ , the light L _S1 travels through the light transmission part 24 at the sunlight advancing angle θ _P1 represented by the following formula (3).

On the other hand, as described above, in the vertical cross section in the thickness direction of the light scattering layer 23 in a posture in which the daylighting sheet 20 is disposed in the opening of the building, one light scattering portion 25 and light transmission sandwiching the light scattering portion 25 Of the interface with the portion 24, the line connecting the indoor side end portion and the outdoor side end portion of the lower interface of the light scattering portion 25 is inclined with θ _D with respect to the horizontal plane. Here, whether or not L _S1 incident on the light transmission part 24 reaches the light scattering part 25 depends on the sunlight traveling angle θ _P1 and the inclination angle θ _D of the light scattering part 25. If the sunlight that has _traveled at the sunlight advancing angle θ _P1 does not reach the light scattering portion 25 and passes through the light transmitting portion 24, the sunlight is irradiated on the indoor ceiling or the like, which causes glare. Direct light can be prevented from reaching a person in the room. Therefore, in order to irradiate the light reflected from the upper surface of the light shelf 30 and applied to the daylighting panel 12 from obliquely below to the light scattering portion 25 without irradiating the light scattering portion 25, θ _D must be large to some extent. Is preferred. Specifically, it is preferable that θ _D > θ _P1 .

FIG. 7 shows light L _S2 from the sun, which is another example of the optical path. As can be seen from FIG. 7, L _S2 is incident on the daylighting panel 12 at an elevation angle (angle formed from a horizontal plane) θ _S2 based on the solar altitude at that time. The light L _S2 incident on the daylighting panel 12 travels through the light transmitting portion 24 of the light scattering layer 23 while passing through the daylighting panel 12. If the refractive index of the light transmission part is N _P and the outdoor refractive index is N ₀ , the light L _S2 travels in the light transmission part 24 at the sunlight advancing angle θ _P2 represented by the following formula (4).

When the sunlight traveling at the sunlight traveling angle θ _P2 reaches the interface between the light transmitting portion 24 and the light scattering portion 25, the refractive index difference between the light transmitting portion 24 and the light scattering portion 25, and the sunlight traveling angle θ. _If the relationship of _P2 is equal to or greater than the total reflection critical angle, the sunlight is totally reflected at the interface between the light transmitting portion 24 and the light scattering portion 25 as shown in FIG. As a result, sunlight is deflected and the sunlight is applied to the ceiling or the like in the room, so that direct light that causes glare can be prevented from reaching a person in the room.

Here, the direction in which sunlight is deflected depends on the sunlight traveling angle θ _P2 that is an angle incident on the interface and θ _U that is the inclination angle of the light scattering portion 25. Therefore, it is preferable that θ _U is determined so that the totally reflected light is upward from the horizontal. Among them, since it is possible to deflect all of the totally reflected light upward, θ _U = 0 ° can be obtained.

FIG. 8 shows light L _S3 from the sun, which is still another example of the optical path. As can be seen from FIG. 8, L _S3 enters the daylighting panel 12 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 12 travels through the light transmitting portion 24 of the light scattering layer 23 while passing through the daylighting panel 12. If the refractive index of the light transmission part is N _P and the outdoor refractive index is N ₀ , the light L _S3 travels in the light transmission part 24 at the sunlight advancing angle θ _P3 represented by the following formula (5).

When sunlight traveling at the sunlight traveling angle θ _P3 reaches the interface between the light transmitting portion 24 and the light scattering portion 25, the refractive index difference between the light transmitting portion 24 and the light scattering portion 25, and the sunlight traveling angle θ. _If the relationship of _P3 is equal to or smaller than the total reflection critical angle, the light _LS3 enters the light scattering portion 25 as shown in FIG. 8, and is scattered and reflected here and emitted to the indoor side. Further, if there is no difference in refractive index between the light transmission part 24 and the light scattering part 25, all light enters the light scattering part 25 and is similarly scattered and reflected to be emitted indoors.

As can be seen from the above, according to the daylighting sheet 20, at least a part of sunlight is irradiated to the ceiling of the room or the like like the light L _S1 , L _S2 , L _S3 regardless of the prospective angles θ ₁ , θ ₂ , In addition, since the light can be provided on the indoor side by being scattered and reflected, at least a part of the direct light (so-called direct sunlight) reaches the indoor person without greatly reducing the amount of incident sunlight. Can be suppressed. Thereby, a bright and comfortable indoor space can be formed.

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 scattering layer 23 at the part where the light transmission part 24 is disposed are formed in parallel and smooth. As a result, as shown in FIG. 8, the light L _K1 accompanying the outdoor scenery can be prevented from being distorted and can enter the room. That is, the scenery on the outdoor side 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.

As described above, according to the daylighting sheet 20, it is possible to eliminate at least part of the direct light while efficiently taking sunlight into the room regardless of the prospective angles θ ₁ and θ ₂ .
However, from the viewpoint to reach the interface with more light transmitting portion 24 and the light scattering portion 25 sunlight entering the lighting sheet 20 from above, it is preferable to define the visual angle theta ₁ to the predetermined angle range. This will be described in detail below.

An explanatory diagram is shown in FIG. Here, the elevation angle θ _SH when the south-high altitude is highest in a year is considered. That is, when sunlight enters the daylighting panel 12 at an elevation angle θ _SH when the altitude is the highest at least in one year, θ ₁ is set from the viewpoint of causing all direct light from the sunlight to reach the light scattering unit 25. Can be prescribed. As can be seen from FIG. 9, the limit for the light L _SH incident at the elevation angle θ _SH to reach the light scattering portion 25 is the situation where the light L _SH travels along the prospective line IVa in the light transmitting portion 24. That is, it is only necessary that the sunlight traveling angle θ _PH in the light transmitting portion 24 is the same as the prospective angle θ ₁ . Therefore, this is expressed by the following formula (6) by the relational expression of the refractive index and the incident angle, where N _{0 is} the refractive index of air and N _p is the refractive index of the light transmission part.

From the formula (6), by constructing the prospective angle θ ₁ so as to satisfy the following formula (1), sunlight is incident on the daylighting panel 12 at an elevation angle θ _SH when the altitude of the south and middle is highest at least in one year. Sometimes all direct light from sunlight can reach the light scattering portion 25.

Since θ _SH is an elevation angle at a position where the south-middle altitude is the highest at a predetermined location, there is no elevation angle with a larger angle at the predetermined location. Therefore, in order to reach all the light scattering portions 25 similarly to sunlight having a predetermined elevation angle lower than this, while satisfying Expression (6) and Expression (1), Expression (6) and Expression (1) are further satisfied. If the predetermined elevation angle is substituted in place of θ _SH of), the value to be taken of θ ₁ can be obtained in the same manner.

For example, direct sunlight from an elevation angle θ _SM or higher between the elevation angle θ _SH when the south-middle altitude is highest in the year and the elevation angle θ _SL when the south-middle altitude is the lowest in the year is a light scattering unit. When it is desired to reach, the prospective angle θ ₁ may be formed so as to satisfy Expression (7) while satisfying Expression (1).

As means for setting the expected angle θ ₁ to the predetermined angle in this way, for example, the pitch of the light scattering portion, the angle of the leg portion of the light scattering portion (θ _U , θ _{D in} FIG. 4), For example, the size in the thickness direction (left and right direction in FIG. 4) and the refractive index of the light transmitting portion can be changed. It is possible to adjust θ ₁ to a predetermined angle by combining these alone or in combination.

By reducing θ ₁ in this way, it is possible to cope with not only the difference in altitude between the south and the middle depending on the season, but also the change in the elevation angle associated with the movement of the sun height during the day. The sunlight reaches the light scattering part, and is totally reflected or scattered and reflected and can be provided indoors.

On the other hand, or the light-scattering layer 23 is thick by reducing the theta _1, sometimes the light transmitting unit 24 may become smaller. As a result, the visibility of the outdoor side may be reduced. From this point of view, the lower limit of θ ₁ is not particularly limited. For example, as shown in FIG. 10, all the direct sunlight from the elevation angle θ _SL when the altitude is the lowest in the south as shown in FIG. From the viewpoint of reaching 25, the lower limit of θ ₁ may be determined. FIG. 10 shows a diagram for explanation.
Since the basic idea is the same as the calculation of Equation (6) and Equation (1), as can be seen from FIG. 10, considering that the sunlight L _SL by the elevation angle θ _SL proceeds along the prospective line IVa. Since it is good, Formula (8) can be obtained.

Here, θ _PL is the sunlight advance angle of the light transmission part at the elevation angle θ _SL . Therefore, equation (2) can be obtained from the purpose of obtaining equations (1) and (8).

Here is a more specific example. When considering Japan, Table 1 shows the elevation angle (θ _SH ) at the highest altitude in the south and middle of the year in Sapporo, Tokyo, and Okinawa, and the elevation angle (θ _SL ) at the lowest altitude in the south and middle of the year. It was.

Based on Table 1, you may comprise the range of (theta) ₁ in Japan like Formula (9) or Formula (10).

  According to Formula (9), all the direct sunlight of the sunlight from the south and middle altitudes at least in the summer solstice can reach the light scattering portion in almost the entire region of Japan. Moreover, according to Formula (10), it is possible to make much sunlight reach | attain a light-scattering part, having still higher visibility.

Further, from the viewpoint of transmitting light that is reflected from the upper surface of the light shelf 30 and is incident on the light transmission part 24 of the daylighting sheet 20 from the oblique lower side like the light L _S1 so as not to enter the light scattering part 25 as much as possible. It is preferable that the angle θ ₂ is as large as possible. While as much as possible by transmitting so as not to be incident on the light scattering unit 25 the light incident on the light transmitting portion 24 of the lighting sheet 20 obliquely from below is reflected by the upper surface of the light shelf 30 as light L _S1, the light L _S2, L From the viewpoint of causing the light incident on the daylighting sheet 20 from obliquely upward as in _S3 to be totally reflected or scattered by the light scattering portion 25 at the interface between the light scattering portion 25 and the light transmitting portion 24, θ ₂ > θ ₁ is satisfied. It is preferable. Is preferably as large as possible are expected angle theta ₂ as described above, by increasing the pitch of the light scattering unit 25 in order to increase the viewing angle theta _2, the visual angle theta ₁ is also increased. In order to increase the expected angle θ ₂ while keeping the expected angle θ ₁ within a predetermined range, it is conceivable to increase the angle θ _D that is the inclination angle of the light scattering portion 25.

  The daylighting sheet 20 described so far may be provided with a configuration for adding other functions 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 can be manufactured, for example, as follows. 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 produced, for example, as follows.

  The light scattering layer 23 of the daylighting sheet 20 can be formed by a method using a mold roll. That is, a mold roll is prepared in which irregularities capable of transferring the light transmitting portion 24 of the light scattering layer 23 are provided on the outer peripheral surface of the cylindrical roll. And the base material used as the base material layer 22 is inserted between a die roll and the nip roll arrange | positioned so as to oppose this. And a mold roll and a nip roll are rotated, supplying the composition which comprises the light transmissive part 24 between one surface and a mold roll among base materials. As a result, the concave / convex concave portions formed on the surface of the mold roll are filled with the composition constituting the light transmitting portion 24, and the composition conforms to the concave / convex surface shape of the mold roll.

  Here, as a composition which comprises the light transmissive part 24, although what was mentioned above is preferable, it is as follows more specifically. That is, the photocurable resin composition which mix | blended the reactive dilution monomer (M1) and the photoinitiator (I1) with the photocurable prepolymer (P1) can be 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 (I1) 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.

  These photocurable prepolymer (P1), reactive diluent monomer (M1) and photopolymerization initiator (I1) can be used alone or in combination of two or more.

  Light is irradiated from the base material side by a light irradiation device to the composition constituting the light transmission part 24 sandwiched between the mold roll and the base material and filled therein. Thereby, the composition which comprises the light transmissive part 24 can be hardened, and the shape can be fixed. And the light transmission part 24 shape | molded on the base material layer 22 is released from a metal mold | die roll with a mold release roll.

  Next, the light scattering portion 25 can be formed by filling the concave portion of the light transmitting portion 24 with the composition constituting the light scattering portion 25 and curing it. In this way, the light scattering layer 23 can be formed on the base material layer 22.

  An adhesive is laminated on the light scattering layer 23 thus formed to form an adhesive layer 26, 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. 11 is a view for explaining a daylighting panel 12 ′ including a daylighting sheet 20 ′ according to a modification, and corresponds to FIG. 8. The daylighting sheet 20 ′ is made of a material that is transmitted and scattered by the light scattering portion 25 ′ and emitted to the indoor side. Except for the light scattering portion 25 ′, it is the same as the daylighting sheet 20, and thus the description of the same configuration is omitted.

  The light scattering portion 25 ′ can be made of a material in which a transparent binder resin and a transparent 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 scattering agent include cross-linked 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 scattering agent. Specific examples of the urethane cross-linked particles include Art Pearl (registered trademark) manufactured by Negami Kogyo Co., Ltd. The scattering agent can also be hollow particles.

According to the daylighting sheet 20 ′ having the light scattering layer 25 ′, as can be seen from FIG. 11, the light reaching the light scattering portion 25 ′ can be transmitted while being scattered and emitted to the indoor side. This makes it possible to reduce direct light while emitting sunlight to the indoor side in the same manner as the daylighting sheet 20.
The form of other parts including the form of the light scattering portion 25 ′ can be considered in the same manner as the daylighting sheet 20.

In each of the following examples and comparative examples, an example in which the elevation angle θ _SL (= 31 °) at the southern middle altitude of the winter solstice in Tokyo is considered will be described.
The refractive index N _p of the light transmitting unit used in the Examples and Comparative Examples are 1.55. Therefore, at the elevation angle θ _SL , the traveling angle (sunlight traveling angle) θ _{P of} sunlight traveling through the light transmitting portion is 19.4 °.

Example 1
In Example 1, the lighting panel by the example of the lighting panel 12 provided with the lighting sheet 20 was produced. The shape of the light scattering layer in Example 1 is shown in FIG. As can be seen from these, in Example 1, the prospective angle θ ₁ was 19.4 °, which was the same as the sunlight traveling angle θ _P at the elevation angle θ _SL .

  The details of the daylighting panel according to Example 1 are as follows.

(1) Preparation of composition for light transmitting part Bisphenol A ethylene oxide / xylylene diisocyanate / phenoxyethyl acrylate / 2-hydroxyethyl acrylate / bismuth tri (2-ethylhexanoate) = 30: 15: 50: 5: 0.02 And reacted at 80 ° C. for 10 hours to obtain a photocurable prepolymer (P1).
Bisphenol A ethylene oxide / isophorone diisocyanate / phenoxyethyl acrylate / bismuth tri (2-ethylhexanoate) = 30: 20: 50: 0.02, mixed at 80 ° C. for 10 hours, and photocurable prepolymer (P2) Got.
Next, 30 parts by mass of the photocurable prepolymer (P1), 30 parts by mass of the photocurable prepolymer (P2), 10 parts by mass of phenoxyethyl acrylate as the reactive dilution monomer (M1), the reactive dilution monomer (M2) ) As bisphenol A ethylene oxide 30 parts by weight, mold release agent (S1) as tetradecanol ethylene oxide 10 mol adduct phosphate 0.03 parts by weight, mold release agent (S2) as stearylamine ethylene oxide 15 mol adduct 0.03 parts by mass, 1 part of 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufacturer name: BASF) as photopolymerization initiator (I1) is mixed, homogenized, and light-transmitted A part composition was obtained.
The light transmitting part constituting composition was applied at a thickness of 100 μm, and the light transmitting part constituting composition was cured by irradiating an ultraviolet ray of 800 mJ / cm ² with a high pressure mercury lamp. Using ATAGO Co., Ltd., the refractive index of 589 nm was measured and found to be 1.55.

(2) Base Material As a base material constituting the base material layer, a polyethylene terephthalate film (trade name: A4300, manufactured by Toyobo Co., Ltd., thickness 100 μm) was used.

(3) Production of mold roll A mold roll used for production of the light scattering layer was produced. The mold roll was cylindrical and was plated with copper, and the copper plated portion was cut with a cutting tool to form a groove corresponding to the light transmitting portion. A diamond tool was used as the tool. Grooves were formed by cutting the outer periphery of the copper plating layer of the mold roll at a predetermined pitch in the roll axis direction. The surface of this cut roll was chrome plated.

(4) Formation of light transmission part The base material of said (2) was conveyed between the metal mold | die roll and nip roll produced by said (3). In accordance with the transport of the base material, the light transmitting part constituting composition obtained in (1) above is supplied onto the base material from the supply device, and the base material layer and the mold are pressed by the pressing force between the mold roll and the nip roll. The light transmitting part constituting composition was filled between the rolls. Then, 800 mJ / cm < ² > of ultraviolet rays were irradiated from the base material side with the high pressure mercury lamp, the light transmissive part constituent composition was hardened, and the light transmissive part was formed. Then, the light transmission part was released from the mold roll with a peeling roll, and a sheet (intermediate member) in which the light transmission part was formed on the base material layer was produced.

  The elastic modulus of the light transmitting portion was measured by applying a load to the micro indenter material using a compression micro hardness tester (FISCHER HM2000) and unloading it. At this time, the load force was 100 mN, the load speed was 4 μm / 10 seconds, and the holding time was 60 seconds. As a result, the elastic modulus of the light transmission part was 800 MPa.

(5) Adjustment of light scattering part constituent composition 42 parts by mass of urethane acrylate as the photocurable prepolymer (P3), 18 parts by mass of epoxy acrylate as the photocurable prepolymer (P4), reactive diluent monomer (M3) As 35 parts by mass of tripropylene glycol diacrylate, 5 parts by mass of methoxytriethylene glycol acrylate as the reactive diluent monomer (M4), 5 parts by mass of titanium oxide as the light scattering agent (D1), and as a photopolymerization initiator (I1), 7 parts by mass of 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufacturer name: BASF) was mixed and homogenized to obtain a light scattering part composition.
In addition, the component except the scattering agent of this light-scattering part constituent composition was applied with a thickness of 100 μm, and cured by irradiating with an ultraviolet ray of 800 mJ / cm ² with a high-pressure mercury lamp. When the refractive index at 589 nm was measured by using Atago, it was 1.49.

(6) Formation of light-scattering part The light-scattering part structure composition obtained by said (5) was supplied from the supply apparatus to the side in which the light transmission part of the intermediate member produced by said (4) was formed. Also, using a doctor blade arranged substantially perpendicular to the traveling direction of the intermediate member, the light scattering portion constituting composition supplied on the intermediate member is filled in a substantially V-shaped groove formed between the light transmission portions. At the same time, the surplus light scattering portion constituting composition was scraped off. Thereafter, the light scattering portion constituting composition was cured by irradiating ultraviolet light of 800 mJ / cm ^{2 with} a high pressure mercury lamp, and the light scattering portion was formed by the cured light scattering portion constituting composition.
A light scattering layer was formed on the base material layer as described above.

(7) Formation of Adhesive Layer Acrylic resin adhesive (trade name: SK Dyne 2094, Soken Chemicals Co., Ltd., 25.0% solids, solvents ethyl acetate and methyl ethyl ketone) and 100 parts by mass of crosslinking agent (E -5XM, L-45, Soken Chemical Co., Ltd., solid content 5.0%) 0.28 parts by mass, 1,2,3-benzotriazole 0.25 parts by mass, diluent (toluene / methyl ethyl ketone / Cyclohexanone = 27.69 g / 27.69 g / 4.61 g) was mixed with 32.0 parts by mass to obtain an adhesive composition. This composition was applied to a release film (trade name: E7007, manufactured by Toyobo Co., Ltd., thickness 38 μm), dried, and bonded to the surface of the light scattering layer. In addition, it was 1.49 when the refractive index of 589 nm was measured about this contact bonding layer using the multiwavelength Abbe refractometer DR-M4 (made by Atago Co., Ltd.). Further, the storage elastic modulus of this adhesive layer was 0.22 MPa.

(8) Production of a daylighting panel A daylighting panel including a light scattering layer was bonded to a light-transmitting plate-like panel with the adhesive layer formed as described above to produce a daylighting panel. After that, the daylighting panel was arranged at the opening on the south surface of the building so that the light transmitting portion and the light scattering portion extended in the horizontal direction and were juxtaposed in the vertical direction.

(Example 2)
FIG. 13 shows the shape of the light scattering layer in Example 2. Example 2 is the same as Example 1 except that the dimensions of each part are changed as shown in FIG.

(Comparative Example 1)
Example 1 is the same as Example 1 except that the front and back sides of the sheet composed of the light scattering layer and the base material layer are reversed.

(Comparative Example 2)
Example 2 is the same as Example 2 except that the front and back sides of the sheet composed of the light scattering layer and the base material layer are reversed.

(Evaluation)
About the lighting panel of each example shown above, sunlight uptake efficiency was evaluated. The evaluation method is as follows. As shown in FIG. 14, the daylighting panel is manufactured to have a height of 60 cm when the panel surface is vertical, and the case where the light shelf is installed horizontally at the lower end of the daylighting panel is not installed. For the above, the brightness of the room when sunlight was projected at the predetermined angles θ _SH and θ _SL was subjectively evaluated. The light shelf is an aluminum plate, and the size is 60 cm from the end in contact with the daylighting panel to the opposite end as shown in FIG. The size was the same as the daylighting panel. The evaluation criteria were ○ when the room was clearly bright when the light shelf was installed compared to when no light shelf was installed, and × when the difference between the two was not clear.

  As shown in Table 2, according to the daylighting panels of Examples 1 and 2, the light reflected from the light shelf and incident from obliquely below was controlled, and sunlight could be efficiently taken into the room.

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 scattering layer 24 Light transmission part 25 Light scattering part 26 Adhesion layer 30 Light shelf

Claims (7)

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, and a light scattering layer that is formed on one surface of the base material layer and scatters light,
The light scattering layer is
A plurality of light transmitting portions that are arranged side by side along one surface of the base material layer and transmit light;
A light scattering part that is disposed between the light transmission parts adjacent to each other and scatters light;
In the vertical cross section in the thickness direction of the light scattering layer in a posture in which the daylighting sheet is arranged in the building opening,
The light scattering unit has an interface with the light transmitting portions above and below, the interface between the lower the indoor side end Ri higher position near from the outdoor-side end portion,
Of the angles formed by the line connecting the indoor-side end and the outdoor-side end of the upper interface with the horizontal plane, the angle smaller than 90 ° is θ _U, and the indoor-side end of the lower interface is When the line connecting the outdoor side end of the corner of 90 ° the smaller of the horizontal plane and the angle and theta _D,
θ _D > θ _U holds, and
The theta _D is greater than 30 ° 0 ° or more,
Daylighting sheet. In the vertical cross section in the thickness direction of the light scattering layer in a posture in which the daylighting sheet is disposed in the building opening, the light scattering portions are juxtaposed in the vertical direction,
The indoor side end portion of the interface above the light scattering portion disposed below the two light scattering portions adjacent to each other, and the interface below the light scattering portion disposed adjacently above Of the light scattering portion disposed above the prospective angle θ ₁ , which is smaller than 90 ° out of the angles formed by the prospective line connecting the outdoor end of the horizontal plane with the horizontal plane. From 90 ° of the angle formed by the prospective line connecting the indoor side end portion of the lower interface and the outdoor end portion of the upper interface of the light scattering portion disposed adjacently and below the horizontal plane When the smaller angle is the prospective angle θ ₂ ,
θ ₂ > θ ₁ is satisfied,
The daylighting sheet according to claim 1 . In the vertical cross section in the thickness direction of the light scattering layer in a posture in which the daylighting sheet is disposed in the building opening, the light scattering portions are juxtaposed in the vertical direction,
The indoor side end portion of the interface above the light scattering portion disposed below the two light scattering portions adjacent to each other, and the interface below the light scattering portion disposed adjacently above The angle that is smaller than 90 ° out of the angle formed by the prospective line connecting the outdoor end of the horizontal plane with the horizontal plane is the prospective angle θ ₁ , and the elevation angle when the sun's south-high altitude is highest in the year is θ _SH . When the refractive index of the material constituting the transmission part is N _P and the refractive index in air is N ₀ ,
The daylighting sheet according to claim 1 or 2 , wherein the following expression (1) is satisfied.

When the elevation angle when the sun culmination altitude lowest of the year and theta _SL, lighting sheet according to claim 3, the following equation (2) is satisfied.

A daylighting device provided in an opening of a building,
A plate-like panel having translucency;
The daylighting sheet according to any one of claims 1 to 4 , which is affixed to one surface of the panel, and a frame arranged to surround at least the periphery of the panel;
A daylighting apparatus. The daylighting apparatus according to claim 5 , further comprising a light shelf outside the daylighting sheet and the panel. A building in which the daylighting device according to claim 5 or 6 is installed in an opening.

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