WO2016088445A1

WO2016088445A1 - Daylighting film

Info

Publication number: WO2016088445A1
Application number: PCT/JP2015/078355
Authority: WO
Inventors: 和也藤岡; 弘義武; 矢野　雅也; 暁恵星子; 周作柴田; 坂本　亨枝
Original assignee: 日東電工株式会社
Priority date: 2014-12-05
Filing date: 2015-10-06
Publication date: 2016-06-09

Abstract

A daylighting film is provided with a support layer and a daylighting layer laminated on the support layer. The daylighting layer is provided with a plurality of transparent parts arranged mutually spaced apart in a first direction orthogonal to the thickness direction of the daylighting layer, and a plurality of gaps arranged one by one between mutually adjacent transparent parts among the plurality of transparent parts. Each of the plurality of gaps extends entirely along the thickness direction of the daylighting layer while extending entirely along a second direction orthogonal to both the thickness direction and the first direction. A volume ratio of the plurality of transparent parts to the daylighting layer is 93 vol% or more. A ratio of the dimension in the first direction of each of the plurality of gaps to the dimension in the first direction of each of the plurality of transparent parts is 0.1 or less.

Description

Daylighting film

The present invention relates to a daylighting film.

Conventionally, so-called daylighting (also referred to as sunlight illumination or daylight illumination) is known in which sunlight is introduced indoors in order to adjust the environment such as the indoor brightness of a building. However, in recent years, from the viewpoint of reducing the environmental load, it has been desired to introduce sunlight more efficiently indoors and reduce the use of artificial lighting during the daytime.

Therefore, there are various ways to efficiently introduce sunlight into an indoor by an optical member capable of changing the traveling direction of light by optical action such as light refraction, diffraction or reflection, and to improve indoor brightness. It is being considered.

As such an optical member, for example, an optical element including a light transmission layer in which a structural layer having voids arranged at a predetermined pitch in the vertical direction is formed on one surface in the thickness direction has been proposed (for example, Patent Document 1).

In such an optical element, sunlight from the outdoors is reflected on the upper surface of the air gap (the interface between the resin material constituting the light transmission layer and the air in the air gap) and is taken indoors.

JP 2012-38626 A

However, the light transmission layer provided in the optical element described in Patent Document 1 is formed by pressing a master having a concavo-convex shape onto a resin sheet and transferring the concavo-convex shape of the master to the resin sheet. The

Therefore, the depth of such voids (the dimension in the thickness direction of the light transmissive layer) is shorter than the thickness of the light transmissive layer, and the light transmissive layer includes portions where voids are not formed in addition to the structural layer where voids are formed. Have. That is, the light transmission layer has a portion that does not contribute to daylighting.

Further, the gap is formed in order to provide the light transmission layer with an interface for reflecting light from outside (that is, the interface between the resin material of the light transmission layer and the air in the gap). If the interface can be formed, it is not necessary to ensure a large gap width (a dimension in a direction perpendicular to the thickness direction of the light transmission layer).

However, in the optical element described in Patent Document 1, since the gap of the light transmission layer is formed by transfer of the master, there is a limit to reducing the width of the gap. There is a limit to improving the number.

As a result, the entire light transmissive layer cannot be effectively used for daylighting, and there is a limit to improving the daylighting efficiency of the optical element including the light transmissive layer.

Therefore, an object of the present invention is to provide a daylighting film capable of improving the daylighting efficiency.

[1] The present invention includes a support layer and a daylighting layer laminated on the support layer, and the daylighting layers are arranged at a distance from each other in a first direction orthogonal to the thickness direction of the daylighting layer. A plurality of transparent portions, and a plurality of gap portions arranged one by one between the transparent portions adjacent to each other among the plurality of transparent portions, each of the plurality of gap portions in the daylighting layer, The volume ratio of the plurality of transparent portions with respect to the daylighting layer is 93% by volume or more while extending over the entire thickness direction and extending in the second direction perpendicular to both the thickness direction and the first direction. The ratio of the dimension in the first direction of each of the plurality of gaps to the dimension in the first direction of each of the plurality of transparent parts is a daylighting film that is 0.1 or less.

According to such a configuration, each of the plurality of gaps extends across the entire thickness direction and the second direction in the daylighting layer, and thus from outside in the thickness direction of the daylighting layer and the entire second direction. Light can be reliably reflected.

The volume ratio of the plurality of transparent portions to the daylighting layer is 93% by volume or more, and the ratio of the dimension in the first direction of the gap portion to the dimension in the first direction of the transparent portion is 0.1 or less. It is.

That is, since the dimension in the first direction of the gap is smaller than the dimension in the first direction of the transparent part, the daylighting layer can be secured while ensuring that the volume ratio of the plurality of gaps to the daylighting layer is less than 7% by volume. In, the number of voids can be reliably increased.

As a result, the entire daylighting layer can be used effectively for daylighting, and the daylighting efficiency of the daylighting film is improved.

[2] The present invention also includes the daylighting film according to the above [1], wherein both end surfaces of the plurality of transparent portions in the first direction are substantially parallel to each other.

According to such a configuration, since both end faces in the first direction of the transparent portion are substantially parallel to each other, light from the outside can be stably taken indoors.

[3] Moreover, the present invention is the above [1] or [2], in which at least one of both end surfaces of the plurality of transparent portions in the first direction has an uneven shape. Includes daylighting film.

According to such a configuration, since at least one of the both end faces in the first direction of the transparent portion has an uneven shape, one surface of the transparent portion having the uneven shape (hereinafter referred to as an uneven surface). ) And the void portion where the uneven surface faces has an uneven shape. Therefore, when light from the outside reaches the interface between the uneven surface and the gap, the light is reflected and scattered.

As a result, since the light introduced indoors is reflected and scattered by the interface between the uneven surface and the gap, the indoor brightness is widened compared with the case where the transparent portion does not have the uneven surface. It is possible to improve the brightness and darkness indoors.

[4] The present invention provides the daylighting film according to the above [2] or [3], wherein each of the plurality of transparent portions has an end face in the first direction inclined with respect to the thickness direction. Including.

According to such a configuration, since the end surface in the first direction of the transparent portion is inclined with respect to the thickness direction, the angle of light introduced indoors can be adjusted as appropriate while having a simple configuration. The brightness (light) distribution in the room can be appropriately controlled.

[5] Further, the present invention provides the above [1] to [4], wherein in the support layer, the material constituting the surface opposite to the daylighting layer has a refractive index of 1.35 to 1.55. The lighting film as described in any one of these is included.

However, the daylighting film can be attached to the object to be adhered such as a glass window from the indoor side. At this time, the daylighting layer is adjacent to the object to be adhered, and the support layer that supports the daylighting layer is positioned on the opposite side of the object to be adhered to the daylighting layer, that is, the indoor side.

And according to said structure, since the refractive index of the material which comprises the surface on the opposite side to the lighting layer of a support layer, ie, the indoor side surface of a support layer, is 1.35 or more and 1.55 or less, The light transmittance can be improved and the haze value (= diffuse transmittance / total light transmittance × 100) can be reduced.

Therefore, it is possible to improve the amount of light taken indoors, and it is possible to reliably improve the daylighting efficiency.

The daylighting film of the present invention can improve daylighting efficiency.

FIG. 1 is a perspective view of a first embodiment of a daylighting film of the present invention. FIG. 2 is a side sectional view of the daylighting film shown in FIG. FIG. 3 is a perspective view of a transparent film according to the daylighting film shown in FIG. FIG. 4 is an explanatory diagram for explaining a process in which the side layer of the laminate is cut after the support is attached to the side of the laminate formed by laminating the transparent film shown in FIG. 3. . FIG. 5 is an explanatory diagram for explaining a process of cutting a plurality of transparent films shown in FIG. 3 from a processed sheet. FIG. 6 is a schematic configuration diagram for explaining a production unit for continuously producing the daylighting film shown in FIG. 1. FIG. 7 is an explanatory diagram for explaining a state in which the daylighting film shown in FIG. 1 is attached to the glass window. FIG. 8A is a side sectional view of a second embodiment of the daylighting film of the present invention. FIG. 8B is an explanatory diagram for explaining a state in which the daylighting film shown in FIG. 8A is attached to the glass window. FIG. 9 is a sectional side view of a third embodiment of the daylighting film of the present invention. FIG. 10 is an explanatory diagram for explaining a daylighting film model in the simulations of Examples 1 and 2 and Comparative Example 1. FIG. 11 is a graph showing simulation results of Examples 1 and 2 and Comparative Example 1. FIG. 12 is an explanatory diagram for explaining a daylighting film model in the simulations of Examples 3 to 7. FIG. 13A is an explanatory diagram for explaining a method of measuring ceiling surface illuminance in Examples 8 and 9. FIG. 13B is a bottom view of the illuminance measurement unit shown in FIG. 13A.

1. As shown in FIG. 1, the daylighting film 1 has a flexible sheet shape (film shape). Specifically, the daylighting film 1 has a predetermined thickness and is orthogonal to the thickness direction. It extends in a predetermined direction (longitudinal direction and lateral direction), and has a flat surface and a flat back surface.

The dimension in the thickness direction of the daylighting film 1 is, for example, 30 μm or more, preferably 50 μm or more, for example, 1500 μm or less, and preferably 500 μm or less from the viewpoint of permeability.

Further, the daylighting film 1 has a rectangular shape when viewed from the thickness direction of the daylighting film 1. The size of the daylighting film 1 is appropriately changed according to the purpose of use, but the dimension in the longitudinal direction (an example of the first direction) orthogonal to the thickness direction of the daylighting film 1 is, for example, 10 cm or more, preferably 60 cm. As described above, for example, 200 cm or less, preferably 100 cm or less, and the dimension in the lateral direction (an example of the second direction) orthogonal to both the thickness direction and the longitudinal direction is, for example, 5 cm or more, preferably 10 cm or more, for example, , 150 cm or less, preferably 80 cm or less.

Such a daylighting film 1 is configured to transmit light and reflect light, and includes a daylighting layer 2, a support 3 as an example of a support layer, and a peeling body 4.

The daylighting layer 2 is sandwiched between the support 3 and the release body 4 in the thickness direction of the daylighting film 1 and has a thin film shape extending in the vertical and horizontal directions.

The daylighting layer 2 includes a plurality of transparent portions 9 and a plurality of gap portions 10.

The plurality of transparent portions 9 are arranged in parallel in the vertical direction with a slight gap (gap portion 10) therebetween. Each of the plurality of transparent portions 9 can transmit light and has a substantially prismatic shape extending in the lateral direction. Each of the plurality of transparent portions 9 extends over the entire thickness direction and lateral direction of the daylighting layer 2.

Further, as shown in FIG. 2, each of the plurality of transparent portions 9 has a substantially rectangular shape in a side view, and includes a first surface 9A that is a lower surface in the vertical direction and a second surface that is an upper surface in the vertical direction. 9B, a third surface 9C that is one surface in the thickness direction, and a fourth surface 9D that is opposite to the third surface 9C in the thickness direction. Each of the first surface 9A and the second surface 9B is substantially parallel to each other, and is along the thickness direction and the lateral direction of the daylighting layer 2.

Each of the plurality of transparent portions 9 is configured to transmit light, and is preferably made of a transparent resin material (hard resin material) from the viewpoint of ease of processing.

Examples of the transparent resin material include known resin materials. Specifically, for example, polyester (for example, polyethylene terephthalate (PET)), polyolefin (for example, polyethylene (PE), polypropylene (PP)) , Polycarbonate (PC), polyvinyl chloride, acrylic resin, polystyrene (PS), epoxy resin, silicone resin, fluororesin, urethane resin, cellulose, polyvinyl butyral, ethylene vinyl acetate copolymer and the like.

Among such transparent resin materials, polyolefin, acrylic resin, polyester and polyvinyl chloride are preferable, and acrylic resin and polyvinyl chloride are more preferable. Such resin materials may be used alone or in combination of two or more.

The vertical dimension of the transparent portion 9 can be appropriately changed depending on the purpose of use, but is, for example, 10 μm or more, preferably 25 μm or more, more preferably 30 μm or more, for example, 500 μm or less, preferably 200 μm or less, The thickness is preferably 70 μm or less, particularly preferably 50 μm or less.

The dimension in the thickness direction of the transparent portion 9 can be appropriately set depending on the purpose of use, but is, for example, 15 μm or more, preferably 30 μm or more, more preferably 50 μm or more, for example, 400 μm or less, preferably 250 μm or less, more preferably. Is 80 μm or less.

The ratio of the dimension in the thickness direction of the transparent part 9 to the dimension in the thickness direction of the transparent part 9 (thickness direction dimension of the transparent part 9 / vertical dimension of the transparent part 9) is, for example, 0.5 or more, preferably 1.0. For example, it is 2.5 or less, preferably 2.0 or less.

The volume ratio of each of the plurality of transparent portions 9 with respect to the daylighting layer 2 (volume per one transparent portion 9 / volume of the daylighting layer 2 × 100) is, for example, 0.0005% by volume or more, and preferably 0.00. 05 volume% or more, for example, 0.5 volume% or less, preferably 0.1 volume% or less.

The volume ratio of the sum of the plurality of transparent portions 9 to the daylighting layer 2 (the sum of the volumes of the plurality of transparent portions 9 / the volume of the daylighting layer 2 × 100) is 93% by volume or more, preferably 95% by volume or more. For example, it is 99 volume% or less, Preferably, it is 98 volume% or less.

Further, the relative refractive index of the transparent portion 9 with respect to the refractive index of air is, for example, 1.3 or more, preferably 1.4 or more, for example, 1.8 or less, preferably 1.65 or less. The refractive index can be measured with a prism coupler.

The plurality of gap portions 10 are partitioned as gaps between the transparent portions 9 adjacent to each other among the plurality of transparent portions 9. That is, each of the plurality of gaps 10 is arranged one by one between the transparent parts 9 adjacent to each other among the plurality of transparent parts 9, and each of the plurality of transparent parts 9 and the plurality of gaps 10. Are arranged alternately in the vertical direction.

More specifically, each of the plurality of gap portions 10 is partitioned by a first surface 9A of the upper transparent portion 9 and a second surface 9B of the lower transparent portion 9 among the adjacent transparent portions 9. Yes.

Therefore, as shown in FIG. 1 and FIG. 2, each of the plurality of gap portions 10 extends over the entire thickness direction in the daylighting layer 2, and extends over the entire lateral direction. The interface 6 is along the thickness direction and the lateral direction.

The vertical dimension of the gap 10 is, for example, 0.05 μm or more, preferably 1 μm or more, for example, 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less.

Further, the ratio of the vertical dimension of one gap 10 to the vertical dimension of one transparent part 9 (the respective vertical dimensions of the plurality of gaps 10 / the respective vertical dimensions of the plurality of transparent parts 9) is For example, it is 0.0001 or more, preferably 0.001 or more, more preferably 0.01 or more and 0.1 or less, preferably 0.05 or less, and more preferably 0.03 or less.

The volume ratio of the sum of the plurality of gaps 10 to the daylighting layer 2 (sum of the volumes of the plurality of gaps 10 / volume of the daylighting layer 2 × 100) is, for example, 1% by volume or more, preferably 2 volumes. % Or more, for example, 7% by volume or less, preferably 5% by volume or less.

The support 3 is disposed on one surface in the thickness direction of the daylighting layer 2 and includes a base material 14 and an adhesive layer 13.

The base material 14 is an outer portion in the thickness direction of the support 3. Examples of the substrate 14 include a PET film, an acrylic resin film, a triacetyl cellulose (TAC) film, and a fluorine-based polymer (for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoro Low adhesion substrate made of ethylene-hexafluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, etc., Low adhesion made of nonpolar polymer (for example, olefin resin such as polyethylene, polypropylene, etc.) Examples include base materials.

The relative refractive index of the base material 14 with respect to the refractive index of air is, for example, 1.3 or more, preferably 1.35 or more, for example, 1.8 or less, preferably 1.6 or less, more preferably 1 .55 or less, particularly preferably 1.45 or less. The refractive index can be measured with a prism coupler.

If the relative refractive index of the base material 14 is not less than the above lower limit and not more than the upper limit, the light transmittance can be improved and the haze value can be reliably reduced.

Among the base materials 14, a transparent base material (film) capable of transmitting light is preferable, and a PET film, a low-adhesive base material made of a transparent nonpolar polymer, and relative Examples thereof include a base material made of a material having a refractive index of 1.35 or more and 1.55 or less, particularly preferably a transparent polypropylene film (relative refractive index: 1.48), an acrylic resin film (relative refractive index: 1.50). ) And TAC film (relative refractive index: 1.49).

The dimension in the thickness direction of the base material 14 is, for example, 10 μm or more, preferably 30 μm or more, for example, 100 μm or less, preferably 50 μm or less.

The light transmittance of the substrate 14 is, for example, 85% or more, preferably 90% or more, more preferably, with respect to light having a wavelength of 440 to 600 nm when the dimension in the thickness direction of the substrate 14 is 50 μm. 92% or more, for example, 98% or less.

The haze value of the substrate 14 is, for example, 1% or more, for example, 20% or less, preferably 18% or less, more preferably 15% or less, and particularly preferably 10% or less. The haze value can be measured according to JIS K7136: 2000.

Further, the base material 14 can be provided with a hard coat layer 15 (indicated by phantom lines in FIG. 2), an antireflection layer 17 (indicated by imaginary lines in FIG. 2), or the like, if necessary.

In addition, although only one of the hard coat layer 15 and the antireflection layer 17 may be provided on the base material 14, preferably both the hard coat layer 15 and the antireflection layer 17 are provided.

The hard coat layer 15 is disposed on the opposite side of the daylighting layer 2 with respect to the base material 14, and is preferably disposed in a thin film shape on the entire one surface in the thickness direction of the base material 14.

The hard coat layer 15 is configured to transmit light and contains, for example, an organic component and particles.

The organic component of the hard coat layer 15 includes a curable resin and organic-inorganic composite particles.

Examples of the curable resin include a thermosetting resin, an ionizing radiation curable resin that is cured by ultraviolet rays or light, and preferably an ionizing radiation curable resin.

Examples of the ionizing radiation curable resin include a curable resin having at least one of an acryloyl group and a methacryloyl group (hereinafter referred to as (meth) acryloyl group), and more specifically, a (meth) acryloyl group. Of (meth) acrylates of silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, polyfunctional compounds (eg, polyhydric alcohols, etc.) Examples thereof include polymers (oligomers or prepolymers). Such ionizing radiation curable resins may be used alone or in combination of two or more.

Organic-inorganic composite particles are prepared by combining inorganic oxide particles and an organic compound having a polymerizable unsaturated group.

Examples of the inorganic oxide particles include silicon oxide particles (silica particles), titanium oxide particles, aluminum oxide particles, zinc oxide particles, tin oxide particles, and zirconium oxide particles. Such inorganic oxide particles may be used alone or in combination of two or more.

As an organic compound having a polymerizable unsaturated group, for example, a polymerizable unsaturated group and a functional group (for example, an alkoxysilyl group) that generates a silanol group by hydrolysis are included in the molecule. The organic compound which has is mentioned.

The polymerizable unsaturated group is a functional group that reacts with the curable resin, such as acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, cinnamoyl group, maleate group, acrylamide group. Etc.

The content ratio of the organic / inorganic composite particles is, for example, from 100 parts by mass to 200 parts by mass, and preferably from 100 parts by mass to 150 parts by mass with respect to 100 parts by mass of the curable resin.

Examples of the particles of the hard coat layer 15 include inorganic particles (for example, the above-described inorganic oxide particles, calcium carbonate particles, barium sulfate particles, talc particles, kaolin particles, and calcium sulfate particles), organic particles (for example, polymethyl Methacrylate resin powder (PMMA particles), silicone resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, polyfluoride And ethylene resin powder). Such particles may be used alone or in combination of two or more.

The content ratio of the particles of the hard coat layer 15 is, for example, 3 parts by mass or more and 20 parts by mass or less, preferably 5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the organic component.

The dimension in the thickness direction of the hard coat layer 15 is, for example, 1 μm or more, preferably 5 μm or more, for example, 30 μm or less, preferably 15 μm or less.

The relative refractive index of the hard coat layer 15 with respect to the refractive index of air is, for example, 1.4 or more, preferably more than 1.5, for example, 1.8 or less, preferably 1.6 or less.

The combination of the base material 14 and the hard coat layer 15 is preferably a base material 14 having a relative refractive index of 1.4 or more and 1.6 or less, and a relative refractive index of more than 1.5, and 1.6 The following combination of the hard coat layer 15 is mentioned, More specifically, the combination of the PET film (base material 14) and the hard coat layer 15 containing a urethane resin or a polyester resin having a (meth) acryloyl group is included. Can be mentioned.

The antireflection layer 17 is disposed on the opposite side of the daylighting layer 2 with respect to the base material 14, and is preferably disposed in a thin film shape on the entire one surface in the thickness direction of the hard coat layer 15.

The antireflection layer 17 is configured to transmit light. Examples of the material for forming the antireflection layer 17 include a resin material such as an ultraviolet curable acrylic resin, a hybrid material in which inorganic particles (for example, colloidal silica) are dispersed in a resin, and a metal alkoxide (for example, tetraethoxy). And sol-gel materials using silane, titanium tetraethoxide, etc.).

The material for forming the antireflection layer 17 preferably contains hollow spherical silicon oxide particles. The average particle diameter of the hollow spherical silicon oxide particles is, for example, 5 nm to 300 nm, and preferably 10 nm to 200 nm.

The dimension in the thickness direction of the antireflection layer 17 is, for example, 0.01 μm or more, preferably 0.1 μm or more, for example, 5 μm or less, preferably less than 1 μm.

The relative refractive index of the antireflection layer 17 with respect to the refractive index of air is, for example, 1.3 or more, preferably 1.35 or more, for example, 1.6 or less, preferably 1.55 or less, more preferably Less than 1.4.

If the relative refractive index of the antireflection layer 17 is not less than the above lower limit and not more than the upper limit, the light transmittance can be improved and the haze value can be reliably reduced.

Further, the relative refractive index of the antireflection layer 17 is preferably smaller than the relative refractive indexes of the hard coat layer 15 and the base material 14.

The combination of the hard coat layer 15 and the antireflection layer 17 is preferably such that the refractive index exceeds 1.5 and the hard coat layer 15 is 1.6 or less, and the refractive index is 1.3 or more and 1.4. Less than antireflection layer 17 combination, more specifically, hard coat layer 15 containing urethane resin or polyester resin having (meth) acryloyl group, and UV curable acrylic resin containing hollow spherical silicon oxide particles And a combination with the antireflection layer 17 formed from the above.

The combination of the base material 14 and the antireflection layer 17 is preferably a base material 14 having a refractive index of 1.4 or more and 1.6 or less, and an antireflection layer having a refractive index of 1.3 or more and less than 1.4. 17, more specifically, a combination of a PET film (base material 14) and an antireflection layer 17 formed from an ultraviolet curable acrylic resin containing hollow spherical silicon oxide particles.

In the first embodiment, the base material 14 is provided with the hard coat layer 15 and the antireflection layer 17, and the combination thereof is a urethane film having a PET film (base material 14) and a (meth) acryloyl group. Or it is the hard-coat layer 15 containing a polyester resin, and the antireflection layer 17 formed from the ultraviolet curing acrylic resin containing a hollow spherical silicon oxide particle.

The light transmittance of the base material 14 on which the hard coat layer 15 and the antireflection layer 17 are provided is, for example, in the same range as the light transmittance range of the base material 14 described above. Moreover, the haze value of the base material 14 on which the hard coat layer 15 and the antireflection layer 17 are provided is, for example, in the same range as the above-described range of the haze value of the base material 14.

Note that the surface of the support 3 opposite to the daylighting layer 2, that is, one surface in the thickness direction of the support 3 is one surface in the thickness direction of the substrate 14 when the antireflection layer 17 is not provided on the substrate 14. The base material 14 constitutes the surface of the support 3 opposite to the daylighting layer 2.

On the other hand, when the antireflection layer 17 is provided on the base material 14, one surface in the thickness direction of the support 3 is one surface in the thickness direction of the antireflection layer 17, and the antireflection layer 17 is daylighted in the support 3. It constitutes the surface opposite to layer 2.

Therefore, in the support 3, the refractive index of the material (base material 14 or antireflection layer 17) constituting the surface opposite to the daylighting layer 2 is preferably 1.35 or more and 1.55 or less.

The pressure-sensitive adhesive layer 13 is an inner portion in the thickness direction of the support 3 and is disposed in a thin layer on the entire inner surface (surface on the daylighting layer 2 side) of the base material 14. That is, the pressure-sensitive adhesive layer 13 is interposed between the base material 14 and the daylighting layer 2, and adheres the daylighting layer 2 and the base material 14. Thereby, the daylighting layer 2 is laminated | stacked on the surface at the side of the adhesive layer 13 of the support body 3, and the some transparent part 9 is sticking the 3rd surface 9C to the adhesive layer 13, It is supported by the support body 3 collectively.

Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 13 include known transparent pressure-sensitive adhesives such as epoxy pressure-sensitive adhesives, silicone pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, and ultraviolet curable pressure-sensitive adhesives.

Among these pressure-sensitive adhesives, an acrylic pressure-sensitive adhesive is preferable. Such pressure-sensitive adhesives may be used alone or in combination of two or more. Moreover, the adhesive layer 13 can also be comprised from a well-known double-sided adhesive tape.

The dimension in the thickness direction of the pressure-sensitive adhesive layer 13 is, for example, 1 μm or more, preferably 5 μm or more, for example, 100 μm or less, preferably 50 μm or less, and more preferably 40 μm or less.

In addition, when the base material 14 itself is sticky, the pressure-sensitive adhesive layer 13 is not necessary in the support 3.

Examples of the support 3 include a known adhesive tape having a base material, preferably a transparent adhesive tape capable of transmitting light. As the support 3, a commercially available product can be used, and examples thereof include SC-01 (manufactured by Nitoms).

The release body 4 is disposed on the other side in the thickness direction of the daylighting layer 2 and includes a release liner 11 and an adhesive layer 12.

The release liner 11 is an outer portion in the thickness direction of the release body 4. The release liner 11 is a resin film having flexibility, and examples thereof include a base material similar to the base material 14, and preferably a PET film.

Although not shown, a release treatment layer is provided on the inner surface of the release liner 11 in the thickness direction. The peeling force of the release liner 11 by the release treatment layer is adjusted as appropriate.

The pressure-sensitive adhesive layer 12 is an inner portion in the thickness direction of the release body 4 and is disposed in a thin layer on the entire inner side surface (the surface on the daylighting layer 2 side) of the release liner 11. That is, the pressure-sensitive adhesive layer 12 is interposed between the release liner 11 and the daylighting layer 2 and is adhered to the release treatment layer (not shown) of the release liner 11 and the other side in the thickness direction of the daylighting layer 2. (More specifically, it is bonded to the fourth surface 9D of the transparent portion 9).

Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 12 include the same pressure-sensitive adhesive as the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 13, and preferably an acrylic pressure-sensitive adhesive. Such pressure-sensitive adhesives may be used alone or in combination of two or more. Moreover, the adhesive layer 12 can also be comprised from a well-known double-sided adhesive tape.

The dimension in the thickness direction of the pressure-sensitive adhesive layer 12 is, for example, the same as the dimension in the thickness direction of the pressure-sensitive adhesive layer 13.

2. The manufacturing method of the lighting film Next, the manufacturing method of the lighting film 1 is demonstrated.

In order to manufacture the daylighting film 1, a plurality of transparent films 16 corresponding to the transparent portion 9 are first prepared (prepared) as shown in FIG.

The transparent film 16 is made of, for example, the transparent resin material described above. As such a transparent film 16, commercially available products can be used. For example, PET (T100-100 (manufactured by Mitsubishi Plastics)), PP (Treffan BO (manufactured by Toray Industries, Inc.)), CPP (P111 (Toyobo Co., Ltd.) Product)), CPP (SOP5T (manufactured by OJK)) and the like.

In order to prepare a plurality of transparent films 16, as shown in FIG. 5, first, a processed sheet 24 made of the above transparent resin material is prepared, and the transparent film 16 having a predetermined shape is cut out from the processed sheet 24.

In order to cut out the transparent film 16 from the processed sheet 24, for example, the processed sheet 24 may be formed large so that a plurality of transparent films 16 can be cut out, and a plurality of transparent films 16 may be cut out from the processed sheet 24. Alternatively, a plurality of processed sheets 24 may be prepared, and the transparent film 16 may be cut out from each processed sheet 24 one by one.

Among such methods, from the viewpoint of manufacturing cost, the processed sheet 24 is preferably formed in a long and flat strip shape that is continuous in a predetermined direction so that a plurality of transparent films 16 can be cut out. A method of cutting a plurality of transparent films 16 from the processed sheet 24 may be mentioned.

Further, when the processed sheet 24 is formed in a long and flat band shape, the processed sheet 24 preferably has flexibility and is wound in a roll shape. Then, the plurality of transparent films 16 are cut out from the part drawn out from the roll-shaped processed sheet 24.

Examples of methods for cutting the transparent film 16 from the processed sheet 24 include known processing methods such as cutting and punching.

The shape of the transparent film 16 is not particularly limited, and is, for example, a polygonal shape or a circular shape, preferably a rectangular shape or a circular shape, and particularly preferably a circular shape when viewed from the thickness direction of the transparent film 16.

The size of the transparent film 16 is appropriately changed according to the purpose of use. Specifically, when the transparent film 16 has a circular shape as viewed from the thickness direction, the diameter is, for example, 10 cm or more, for example, 100 cm or less, and preferably 50 cm or less from the viewpoint of workability. Each of the plurality of transparent films 16 is formed in substantially the same size.

Thereby, a plurality of transparent films 16, for example, 300 sheets or more, preferably 500 sheets or more, more preferably 1000 sheets or more, for example, 60000 sheets or less, preferably 10,000 sheets or less are prepared. The

Next, as shown in FIG. 4, each of the plurality of transparent films 16 is laminated in the thickness direction without sandwiching the pressure-sensitive adhesive layer, thereby preparing (preparing) a laminate 20. That is, the thickness direction of the transparent film 16 and the lamination direction of the laminated body 20 are the same direction. Further, the outer peripheral edges of the plurality of transparent films 16 coincide with each other when projected in the stacking direction.

In the laminate 20, a slight amount of air is interposed between the transparent films 16 adjacent to each other in the stacking direction, and the air is provided as a gap layer 23 to partition the adjacent transparent films 16. .

Thus, the laminate 20 extending in the lamination direction is prepared. For example, when the transparent film 16 is rectangular when viewed from the thickness direction, a prismatic laminate 20 is prepared, and when the transparent film 16 is circular when viewed from the thickness direction, a cylindrical laminate 20 is prepared. Is done.

In FIG. 4, for convenience, the number of transparent films 16 is omitted, and the stacked body 20 is described as being composed of 8 transparent films 16. For example, the transparent film 16 includes 300 to 60000 sheets, preferably 500 to 30000 sheets, and more preferably 1000 to 10,000 sheets.

The height (length in the stacking direction) of the stacked body 20 is, for example, 1 cm or more, preferably 5 cm or more, more preferably 40 cm or more, for example, 200 cm or less, preferably 100 cm or less.

Next, the support 3 is attached to the side surface 21 (surface extending along the lamination direction) of the laminate 20 so as to be along the lamination direction (thickness direction of the transparent film 16).

In order to attach the support 3 to the side surface 21 of the stacked body 20, the stacked body 20 is held by applying pressure to the stacked body 20 from both sides in the stacking direction.

As the pressurizing condition, the pressure from the outside in the stacking direction with respect to the stacked body 20 is, for example, 0.01 MPa or more, preferably 0.1 MPa or more, for example, 10 MPa or less, preferably 5 MPa or less.

Then, the support 3 is continuously attached to the laminate 20 using, for example, a touch roll so that the pressure-sensitive adhesive layer 13 of the support 3 adheres to the side surface 21 of the laminate 20.

Thereafter, the side surface 21 of the laminate 20 to which the support 3 is attached is cut so that the plurality of transparent films 16 are arranged in parallel in the lamination direction of the laminate 20.

The cutting method for cutting the side surface 21 of the laminate 20 is not particularly limited as long as the side surface 21 supported by the support 3 can be cut out from the laminate 20. In such a cutting method, preferably, the laminated body 20 is formed in a cylindrical shape, the cutting blades 34 are arranged along the laminating direction, and then the laminated body 20 is rotated around the axis line to obtain the laminated body 20. From the above, a method of continuously cutting out the side layer 22 supported by the support 3 like a wig is mentioned.

Thereby, the side layer 22 of the stacked body 20, that is, the daylighting layer 2 is cut out from the stacked body 20. Thereafter, as shown in FIG. 1, the peeling body 4 is attached to the surface of the lighting layer 2 opposite to the support 3.

By the above, the lighting film 1 provided with the lighting layer 2, the support body 3, and the peeling body 4 is prepared.

Such a daylighting film 1 is preferably continuously manufactured by a manufacturing unit 28 from the viewpoint of productivity as shown in FIG. In FIGS. 4 and 6, the support 3 is shown as a single layer for convenience.

The manufacturing unit 28 includes a cutting device 29 and a winding device 30.

The cutting device 29 is configured to continuously cut the side surface layer 22 of the laminate 20 to which the support 3 is attached after the support 3 is attached to the side 21 of the laminate 20. The cutting device 29 includes a rotating shaft 32, a pair of holding members 33, and a cutting blade 34.

The rotating shaft 32 has a substantially cylindrical shape and is configured to be rotatable around the axis. A long and flat belt-like support 3 is wound around the rotating shaft 32. Specifically, the long and flat belt-shaped support 3 is wound around the rotary shaft 32 in a spiral shape so that the pressure-sensitive adhesive layer 13 is positioned on the inner side in the radial direction of the rotary shaft 32 with respect to the base material 14. . Thus, the support 3 is configured as a support roll 35 centered on the rotation shaft 32.

In the support roll 35, the support 3 is disposed adjacent to the radial direction of the rotating shaft 32, and the adhesive layer 13 and the base material 14 are sequentially and repeatedly disposed.

In addition, when the support body 3 is comprised as the support body roll 35, the peeling process layer is provided in the surface on the opposite side to the adhesive layer 13 in the base material 14. FIG. Therefore, in the radial direction of the rotating shaft 32, the pressure-sensitive adhesive layer 13 of the support 3 arranged on the radially outer side between the support bodies 3 adjacent to each other, and the support 3 arranged on the radially inner side. A release treatment layer (not shown) is interposed between the substrate 14 and the substrate 14.

The pair of holding members 33 are arranged at a lower left side with respect to the support roll 35 in FIG. Each of the pair of holding members 33 has a substantially disc shape, and is configured to be rotatable about its axis.

Further, the pair of holding members 33 are arranged in the same direction as the direction in which the rotating shaft 32 extends and spaced from each other. The pair of holding members 33 hold the stacked body 20 by sandwiching the substantially cylindrical stacked body 20 from both sides in the stacking direction with the above pressure. In addition, each holding member 33 is arrange | positioned so that the laminated body 20 and an axis line may correspond in the state which hold | maintained the laminated body 20. FIG.

The cutting blade 34 is arranged along the stacking direction with respect to the side surface 21 of the stacked body 20 held by the pair of holding members 33, and the tip of the cutting blade 34 is placed on the side surface 21 of the stacked body 20. In contact.

In addition, when the diameter of the laminated body 20 decreases as the cutting of the laminated body 20 progresses, the cutting blade 34 maintains the state in which the tip of the cutting blade 34 is in contact with the side surface 21 of the laminated body 20. It is configured to approach 20 axes.

The winding device 30 is configured to continuously wind up the daylighting film 1 after the peeling body 4 is attached to the daylighting layer 2 (the side layer 22 of the laminated body 20) supported by the support body 3. In FIG. 6, the cutting device 29 is arranged with an interval to the right.

The winding device 30 includes a rotating shaft 38, a winding shaft 39, and a plurality (two) of rollers 40.

Rotating shaft 38 is arranged with an interval to the upper right with respect to rotating shaft 32 in FIG. The rotation shaft 38 has a substantially cylindrical shape extending in the same direction as the rotation shaft 32 and is configured to be rotatable about the axis. A long and flat strip-shaped peeling body 4 is wound around the rotary shaft 38. Specifically, the long and flat strip-shaped release body 4 is spirally wound around the rotation shaft 38 such that the pressure-sensitive adhesive layer 12 is positioned radially outside the rotation shaft 38 with respect to the release liner 11. . Thus, the peeling body 4 is configured as a peeling body roll 41 centering on the rotation shaft 38.

In the peeling body roll 41, the peeling body 4 is arranged adjacent to each other in the radial direction of the rotary shaft 38, and the pressure-sensitive adhesive layer 12 and the peeling liner 11 are sequentially and repeatedly arranged.

In addition, when the peeling body 4 is comprised as the peeling body roll 41, a peeling process layer is provided also in the surface on the opposite side to the adhesive layer 12 in the peeling liner 11. FIG. Therefore, in the radial direction of the rotating shaft 38, between the adjacent release bodies 4, specifically, the release liner 11 of the release body 4 disposed on the radially outer side and the adhesion of the release body 4 disposed on the radially inner side. A release treatment layer (not shown) is interposed between the agent layer 12.

In FIG. 6, the winding shaft 39 is disposed with a space to the right with respect to the pair of holding members 33, and is disposed with a space to the lower right with respect to the rotation shaft 38. .

The take-up shaft 39 has a substantially cylindrical shape extending in the same direction as the rotation shaft 32, and is configured to be rotatable around the axis. Although the winding shaft 39 will be described later, the manufactured daylighting film 1 is wound.

Each of the plurality of rollers 40 extends in the same direction as the rotating shaft 32 and is appropriately disposed at a predetermined position.

In order to continuously manufacture the daylighting film 1 with such a manufacturing unit 28, first, the side surface 21 of the laminate 20 in which the support 3 drawn out from the support roll 35 is held by the pair of holding members 33. Paste to.

More specifically, the support 3 is drawn toward the tangential direction of the laminate 20 such that the pressure-sensitive adhesive layer 13 of the drawn support 3 adheres to the side surface 21 of the laminate 20, and the central angle in the laminate 20 is For example, it is attached to the side surface 21 of the laminate 20 in the range of 90 ° to 270 °, preferably in the range of 120 ° to 240 °.

Next, the pair of holding members 33 are rotationally driven in the counterclockwise direction when viewed from the front side in FIG. 6 by a driving force from a driving source such as a motor provided in the cutting device 29.

Then, the laminate 20 held by the pair of holding members 33 rotates about the axis, and the support roll 35 is driven about the axis of the rotation shaft 32.

Thus, the side layer 22 of the laminate 20 to which the support 3 is attached is continuously cut out by the cutting blade 34 like a wig.

As described above, the daylighting layer 2 supported by the support 3 is formed into a long and flat strip shape, and is continuously prepared from the laminate 20 and the support roll 35.

Next, the peeling body 4 is pulled out from the peeling body roll 41, and the pressure-sensitive adhesive layer 12 of the peeling body 4 is adhered to the exposed daylighting layer 2 (the surface of the daylighting layer 2 opposite to the support 3). The peeling body 4 is affixed. Thereby, the long and flat strip-shaped daylighting film 1 is manufactured.

Thereafter, the end of the daylighting film 1 is fixed to the take-up shaft 39, and the take-up shaft 39 is rotated in the clockwise direction when viewed from the front side of the paper surface of FIG. Then, the daylighting film 1 is wound around the winding shaft 39 and wound around the winding shaft 39 in a spiral shape to form a roll.

As shown in FIG. 7, the daylighting film 1 manufactured in this way is attached to an inner surface of a glass window 44 as an example of a sticking object in a building such as a house 43.

In order to attach the daylighting film 1 to the glass window 44 or the like, first, the daylighting film 1 is cut into a shape and size corresponding to the attachment location. Examples of the method for cutting the daylighting film 1 include known processing methods such as cutting and punching.

Next, as shown in FIG. 1, the release liner 11 of the release body 4 is peeled from the pressure-sensitive adhesive layer 12 to expose the pressure-sensitive adhesive layer 12.

Then, as shown in FIG. 7, the daylighting film 1 (excluding the release liner 11) is disposed, for example, so that the vertical direction (stacking direction of the transparent portion 9) is along the vertical direction, and the exposed adhesive layer 12 is disposed. And affixing to the inner surface of the glass window 44.

Thereafter, the daylighting layer 2 is pressed toward the glass window 44 from the inside of the house 43 through the support 3 by, for example, a hand roller.

Thus, the daylighting layer 2 supported by the support 3 is attached to the inner side surface of the glass window 44. In the first embodiment, the support 3 is held on the daylighting layer 2 without being peeled off. Therefore, it is not necessary to provide a release treatment layer on the surface of the base material 14 on the pressure-sensitive adhesive layer 13 side. Further, the base material 14 of the support 3 is provided with a hard coat layer 15 and an antireflection layer 17, and the antireflection layer 17 is located most indoor side in the support 3.

When the daylighting layer 2 is attached to the glass window 44, a part of the light L <b> 1 out of the sunlight L incident from the outside through the glass window 44 is transmitted through the transparent portion 9 and the floor portion 45 of the house 43. Proceed toward.

On the other hand, among the sunlight L incident from the outside, the light L2 of the other part is incident on the transparent part 9, and then the gap 10 between the transparent parts 9 adjacent to each other in the vertical direction (more specifically, The light is reflected by the first surface 9A (lower surface) of the transparent portion 9 and the interface 6 (see FIG. 2) between the gap portion 10 and travels toward the ceiling portion 46 of the house 43.

Therefore, according to the daylighting film 1, it can daylight efficiently and the brightness of the whole house 43 can be improved efficiently.

In such a daylighting film 1, as shown in FIGS. 1 and 2, each of the plurality of gaps 10 extends throughout the thickness direction and the lateral direction in the daylighting layer 2. Therefore, as shown in FIG. 7, the sunlight L from the outdoors can be reliably reflected in the thickness direction and the entire lateral direction of the daylighting layer 2.

The volume ratio of the plurality of transparent portions 9 to the daylighting layer 2 is 93% by volume or more, and the ratio of the vertical dimension of the gap portion 10 to the vertical dimension of the transparent portion 9 is 0. 1 or less.

That is, since the vertical dimension of the gap 10 is significantly smaller than the vertical dimension of the transparent part 9, the volume ratio of the plurality of gaps 10 to the daylighting layer 2 can be ensured to be 7% by volume or less. However, in the daylighting layer 2, the number of the space | gap part 10 can be increased reliably.

As a result, the entire daylighting layer 2 can be effectively used for daylighting, and the daylighting efficiency of the daylighting film 1 can be improved.

Further, both end surfaces (specifically, the first surface 9A and the second surface 9B) of the transparent portion 9 in the vertical direction are substantially parallel to each other. Therefore, the sunlight L from the outdoors can be stably taken indoors.

Also, both end surfaces in the vertical direction of the transparent portion 9 (specifically, the first surface 9A and the second surface 9B) are along the thickness direction and the lateral direction of the daylighting film 1. Therefore, it is possible to ensure transparency when the daylighting film 1 is viewed from the thickness direction.

In addition, as shown in FIG. 7, in the state where the daylighting layer 2 supported by the support 3 is attached to the inner side surface of the glass window 44, the antireflection layer 17 has a glass window 44 with respect to the daylighting layer 2. It is located on the opposite side, that is, on the indoor side.

The antireflection layer 17 constitutes an indoor surface of the support 3, and the refractive index of the antireflection layer 17 is preferably 1.35 or more and 1.55 or less. Therefore, the light transmittance of the support 3 can be improved and the haze value can be reduced. As a result, it is possible to improve the amount of light taken indoors, and to reliably improve the daylighting efficiency.

In the first embodiment, the support 3 is attached to the daylighting layer 2 even after the daylighting layer 2 is attached to the glass window 44. However, the support 3 is not limited to this. After the daylighting layer 2 is attached to the glass window 44, it can be peeled off from the daylighting layer 2.

Moreover, in 1st Embodiment, although the hard-coat layer 15 and the antireflection layer 17 are provided in the base material 14, it is not limited to this, The hard-coat layer 15 and the antireflection layer 17 do not need to be provided. .

Moreover, in 1st Embodiment, although the lighting film 1 is provided with the peeling body 4, the lighting film 1 may be comprised only from the lighting layer 2 and the support body 3. FIG. In this case, before the daylighting film 1 is attached to the glass window 44 or the like, an adhesive is applied to the surface of the daylighting layer 2, and the daylighting film 1 is attached to the glass window 44 or the like by the adhesive.
3. Second Embodiment Next, a second embodiment of the optical film of the present invention will be described with reference to FIGS. 8A and 8B. In the second embodiment, the same reference numerals are given to the same members as those in the first embodiment, and the description thereof is omitted.

In the first embodiment, as shown in FIG. 2, the first surface 9A of the transparent portion 9 is a substantially flat surface, but in the second embodiment, the first surface 9A of the transparent portion 9 has an uneven shape. It is configured as an uneven surface 49.

The uneven surface 49 may be a part of the first surface 9A of the transparent portion 9, but is preferably spread over the entire first surface 9A from the viewpoint of light scattering. The interface 6 between the uneven surface 49 and the gap 10 has a shape corresponding to the uneven surface 49.

As shown in FIG. 8B, the shape of the concave portion 49A on the uneven surface 49 is not particularly limited. For example, the concave portion 49A has a substantially arc shape, a substantially cone shape (for example, a cone, a pyramid shape), a substantially frustum shape (for example, A truncated cone and a truncated cone). In the second embodiment, the recess 49A of the uneven surface 49 has a substantially semicircular arc shape.

Such an uneven surface 49 is formed by, for example, a known embossing process.

The density of the concave portions 49A of the uneven surface 49 is, for example, 50 pieces / cm ² or more, preferably 500 pieces / cm ² or more, for example, 5 million pieces / cm ² or less, preferably 500,000 pieces / cm ² or less. is there.

In order to manufacture such a daylighting film 1, as shown in FIG. 3, first, a plurality of transparent films 50 having uneven surfaces 49 are prepared (prepared).

The transparent film 50 is made of, for example, the above transparent resin material. As such a transparent film 50, a commercially available product (generally called an embossed film, a satin film, etc.) can be used. For example, PVC satin clear # 320 (manufactured by Okamoto), Emasoft 3C satin clear (Okamoto) And N Clear (manufactured by Tatsuno Chemical Co., Ltd.).

In order to prepare a plurality of transparent films 50, first, as shown in FIG. 5, a processed sheet 51 made of the above-described transparent resin material is prepared, and at least one surface of the processed sheet 51 has a known embossing process. After forming the uneven surface 49 (see FIG. 8A), the transparent film 50 having a predetermined shape is cut out from the processed sheet 51.

As a method of cutting out the transparent film 50 from the processed sheet 51, for example, the same method as the method of cutting out the transparent film 16 from the processed sheet 24 described above can be cited. Preferably, the processed sheet 51 is formed into a long and flat strip shape. Examples of the method include a method of cutting a plurality of transparent films 50 from a portion drawn out from the roll-shaped processed sheet 51 after being formed and wound into a roll.

Then, each of the plurality of transparent films 50 is laminated in the thickness direction without sandwiching the pressure-sensitive adhesive layer in the same manner as in the first embodiment, thereby preparing (preparing) the laminate 20 (see FIG. 4). .

Thereafter, as in the first embodiment, after the support 3 is attached to the side surface 21 of the laminate 20, the side layer 22 (that is, the daylighting layer 2) of the laminate 20 is continuously peeled off, for example, like a wig. (See FIG. 4). Next, as shown in FIG. 8A, in the daylighting layer 2, the daylighting film 1 including the daylighting layer 2, the support body 3, and the peeling body 4 is obtained by attaching the peeling body 4 to the surface opposite to the support body 3. Prepared.

Note that such a daylighting film 1 is also preferably manufactured continuously by the manufacturing unit 28 from the viewpoint of productivity as shown in FIG.

And when this lighting film 1 is affixed on the inner surface of the glass window 44 as shown in FIG. 8B, for example, a part of the sunlight L incident from outside the house 43 through the glass window 44. The light L1 passes through the transparent portion 9 and travels toward the floor portion 45 of the house 43.

On the other hand, among the sunlight L incident from the outside, the light L2 of the other part is incident on the transparent part 9, and then the gap 10 between the transparent parts 9 adjacent to each other in the vertical direction (more specifically, The light is reflected and scattered by the uneven surface 49 (lower surface) of the transparent portion 9 and the interface 6 between the gap portion 10 and introduced into the house 43. Therefore, the brightness in the house 43 can be improved over a wide range, and the brightness in the house 43 can be reduced.

Moreover, in 2nd Embodiment, although only the lower surface (1st surface 9A) of the transparent part 9 is the uneven surface 49, at least one surface has uneven | corrugated shape among the vertical direction both end surfaces of the transparent part 9. The upper surface (second surface 9B) of the transparent portion 9 can be configured as the uneven surface 49 in addition to the lower surface (first surface 9A) of the transparent portion 9.

Also in such 2nd Embodiment and its modification, there can exist an effect similar to above-described 1st Embodiment.
3. Third Embodiment Next, a third embodiment of the optical film of the present invention will be described with reference to FIG.

In the first embodiment, each of the first surface 9A and the second surface 9B of the transparent portion 9 is along the thickness direction of the daylighting layer 2 as shown in FIG. In the embodiment, as shown in FIG. 9, each of the first surface 9 </ b> A and the second surface 9 </ b> B of the transparent portion 9 is inclined with respect to the thickness direction of the daylighting layer 2.

That is, the gap 10 defined by the first surface 9A and the second surface 9B is inclined with respect to the thickness direction of the daylighting layer 2. Further, the gap 10 may be inclined upward as it goes from one side in the thickness direction (the support 3 side) to the other side (the peeling body 4 side), and from the one side in the thickness direction (the support 3 side) to the other side. Although it may incline below as it goes to (the peeling body 4 side), it preferably inclines upward as it goes from the one side in the thickness direction (the supporting body 3 side) to the other side (the peeling body 4 side).

The inclination angle of the gap 10 with respect to the thickness direction of the daylighting layer 2 is, for example, ± 5 ° or more and ± 20 ° or less, preferably ± 5 ° or more and ± 15 ° or less, more preferably ± 5 ° or more and ± 10 ° or less. It is.

If the inclination angle of the air gap 10 is not less than the above lower limit and not more than the upper limit, the angle of light introduced indoors can be reliably adjusted.

The inclination angle of the gap portion 10 is positive when the gap portion 10 is inclined upward from one side in the thickness direction to the other side, and the gap portion 10 is directed from one side to the other side in the thickness direction. The case where it is inclined downward is negative.

Such a daylighting film 1 according to the third embodiment can be manufactured by the same method as in the first embodiment, and is used by being attached to the glass window 44 of the house 43, for example.

Since each of the first surface 9A and the second surface 9B (that is, the gap portion 10) of the transparent portion 9 is inclined with respect to the thickness direction, the light introduced into the house 43 while having a simple configuration. Can be adjusted as appropriate, and the distribution of brightness (light) in the house 43 can be appropriately controlled.

Also, the third embodiment can provide the same operational effects as those of the first embodiment and the second embodiment.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited thereto. Specific numerical values such as blending ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned “Mode for Carrying Out the Invention”, and the corresponding blending ratio (content ratio) ), Physical property values, parameters, etc. The upper limit value (numerical value defined as “less than” or “less than”) or lower limit value (number defined as “greater than” or “exceeded”) may be substituted. it can.

Example 1
In order to confirm the influence on the reflection efficiency (reflected light intensity L _r / incident light intensity L _i ) of the volume ratio of the transparent part with respect to the daylighting layer and the vertical dimension ratio of the void to the transparent part, Simulation analysis was performed. For the simulation, Lighttools (optical simulation software, manufactured by Optical Research Associates) was used. In this analysis, the lighting film model shown in FIG. 10 was simulated. That is, the daylighting film model consists of only the daylighting layer.

The results are shown in Table 1 and FIG.
<Conditions>
Material of transparent part 9: Acrylic resin Vertical dimension L1: 200 μm of transparent part 9
Thickness direction dimension L2 of transparent part 9 (gap part 10): 200 μm
Volume ratio of the plurality of transparent portions 9 with respect to the daylighting layer 2: 97.6% by volume
Material of air gap 10: Air Vertical dimension L3 of air gap 10: 5 μm
Volume ratio of the plurality of gaps 10 to the daylighting layer 2: 2.4% by volume
Incident angle θ1: Change by 10 ° in the range of 30 ° -80 ° Blackbody radiation (7500)
Example 2
A simulation was carried out in the same manner as in Example 1 except that the vertical dimension L3 of the gap 10 was changed to 1 μm.

The volume ratio of the plurality of transparent portions 9 to the daylighting layer 2 was 99.5% by volume, and the volume ratio of the plurality of gaps 10 to the daylighting layer 2 was 0.5% by volume.

Comparative Example 1
A simulation was performed in the same manner as in Example 1 except that the vertical dimension L3 of the gap 10 was changed to 50 μm.

The volume ratio of the plurality of transparent portions 9 to the daylighting layer 2 was 80.0% by volume, and the volume ratio of the plurality of gaps 10 to the daylighting layer 2 was 20.0% by volume.

Examples 3-7
As shown in FIG. 12, in order to confirm the influence of the inclination angle θ2 of the gap portion (the first surface and the second surface of the transparent portion) on the emission angle θ3 of the reflected light, Table 2 The analysis by the simulation under the inclination angle θ2 shown and the following conditions was performed.

In addition, Lighttools (Optical simulation software, the product made by Optical Research Associates) was used for the simulation. In this analysis, the lighting film model shown in FIG. 12 was simulated. That is, the daylighting film model consists of only the daylighting layer.

The results are shown in Table 2.
<Conditions>
Material of transparent part 9: acrylic resin Vertical dimension L1 of transparent part 9: 100 μm
Thickness direction dimension L2 of transparent part 9 (gap part 10): 150 μm
Volume ratio of the plurality of transparent portions 9 with respect to the daylighting layer 2: 99.0% by volume
Material of void 10: Air Vertical dimension L3 of void 10: 1 μm
Volume ratio of the plurality of gaps 10 to the daylighting layer 2: 1.0% by volume
Incident angle θ1: 50 °
Blackbody radiation (7500)

Example 8
An unstretched polypropylene film (processed sheet, manufactured by OJK, trade name: SOP5T) having a thickness of 65 μm was punched into a circular shape having a diameter of 25 cm, thereby producing 600 circular transparent films. In addition, each of the thickness direction both surfaces of the transparent film was a substantially flat surface, and the relative refractive index of the polypropylene film film with respect to air was 1.48.

Next, after laminating 600 circular transparent films without using an adhesive between the transparent films, the laminate was held in a cylindrical shape by applying pressure (5 MPa) from both sides in the laminating direction. Prepared. The laminate had a diameter of 25 cm × a height (a length in the stacking direction) of 39 mm (65 μm × 600).

Next, the laminate and the support were set in the production unit 28 shown in FIG.

Specifically, the laminate was held by a pair of holding members 33 so as to be sandwiched from both sides in the lamination direction, and the support was wound around the rotating shaft 32 to constitute a support roll.

At this time, the pair of holding members 31 sandwiched the laminated body from both sides in the laminating direction at the pressure (5 MPa). Further, the support had a PET film (base material) having a thickness of 50 μm and an acrylic pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) having a thickness of 50 μm. The acrylic pressure-sensitive adhesive layer was formed on one side of the PET film, and a release treatment layer with a release treatment agent was provided on the other side of the PET film. The relative refractive index of the PET film with respect to air was 1.60.

Further, in a state where the laminated body is held by the pair of holding members 31, the tip of the cutting blade 34 is in contact with the side surface of the laminated body. In addition, the cutting blade 34 was arrange | positioned along the lamination direction of a laminated body.

Then, the support pulled out from the support roll is drawn toward the tangential direction of the laminate so that the adhesive layer adheres to the side of the laminate, and the side of the laminate in the range of the central angle of 240 ° in the laminate Pasted on.

Subsequently, the pair of holding members 31 were driven to rotate counterclockwise as viewed from one axial direction of the holding member 31 (front side in FIG. 6) by a motor (not shown) of the manufacturing unit 28. .

Then, the laminated body held by the pair of holding members 31 was rotated about the axis, and the support roll was driven about the axis of the rotating shaft 32.

Thereby, the side layer of the laminate to which the support was attached was continuously cut out like a wig, and a daylighting layer supported by the support was obtained.

Next, the release body was pulled out from the release body roll, and the release body was attached to the surface (cut surface) opposite to the support in the daylighting layer.

As described above, a long and flat strip-shaped daylighting film including a daylighting layer, a support and a release body was prepared, and the daylighting film was wound around the winding shaft 39.

The daylighting layer of the daylighting film has a plurality of transparent portions and a plurality of gap portions, and the plurality of transparent portions and the plurality of gap portions are continuous so as to alternate with each other in the stacking direction (vertical direction of the daylighting layer). Was arranged. The daylighting layer had a thickness of 200 μm.

Example 9
A daylighting film was prepared in the same manner as in Example 8, except that an unstretched polypropylene film (processed sheet) was previously embossed. In addition, each of the thickness direction both surfaces of each transparent film was formed as an uneven surface.

Example 10
A daylighting film was obtained in the same manner as in Example 8, except that the unstretched polypropylene film (processed sheet) was changed to a 100 μm-thick polyvinyl chloride film (processed sheet, manufactured by Tatsuno Chemical Co., Ltd., trade name: N clear). Prepared.

In addition, each of the thickness direction both surfaces of each transparent film was formed as an uneven surface, and the relative refractive index of the polyvinyl chloride film was 1.54.

Example 11
In the same manner as in Example 10, except that the support was changed to a support having an acrylic resin film (base material) having a thickness of 50 μm and an acrylic pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) having a thickness of 50 μm, the daylighting was performed. A film was prepared. The relative refractive index of the acrylic resin film with respect to air was 1.50.

Example 12
The support includes a PET film (base material) having a thickness of 50 μm and an acrylic pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) having a thickness of 50 μm. The hard coat layer having a thickness of 10 μm and a thickness of 1 μm are provided on the PET film (base material). A daylighting film was prepared in the same manner as in Example 10 except that the support was provided with less than the antireflection layer.

The relative refractive index of the PET film with respect to air was 1.60, the relative refractive index of the hard coat layer was 1.53, and the relative refractive index of the antireflection layer was 1.38.

Further, the hard coat layer contained a urethane resin or polyester resin having a (meth) acryloyl group, and the antireflection layer was formed from an ultraviolet curable acrylic resin containing hollow spherical silicon oxide particles.

(Evaluation)
<Measurement of ceiling surface illumination>
For the daylighting films of Examples 8 and 9, the ceiling surface illuminance was measured as follows.

As shown in FIG. 13A, a room 90 including a wall portion 91 on which a transparent glass window 92 is installed, a floor portion 93, and a ceiling portion 94 was prepared. The glass window 92 had a square shape with a side of 14 cm, and the thickness of the glass window 92 was 3 mm. Moreover, the distance H between the upper end part of the glass window 92 and the lower surface of the ceiling part 94 was 4 cm.

Also, an illuminance measurement unit 95 is arranged on the lower surface of the ceiling portion 94.

As shown in FIG. 13B, the illuminance measuring unit 95 includes a plurality of (six) illuminance meters 97 (manufactured by T & D Co., Ltd., illuminance UV recorder, trade name: TR-74Ui) in the front-rear direction (lighting film thickness direction). A plurality (three) of rows 95A arranged at equal intervals in the left-right direction (lateral direction of the daylighting film) were included.

Of the three columns 95A, the column 95A at the center in the left-right direction passes through the center in the left-right direction of the glass window 92 when viewed from below, and is arranged so as to overlap with a virtual line along the front-rear direction.

In each row 95A, the front-rear direction interval between the illuminance meters 97 adjacent to each other among the six illuminance meters 97 is 6.43 cm, and the illuminance meter 97 disposed at the front end in each row 95A, the glass window 92, The distance in the front-rear direction was 6.43 cm.

Then, white light was irradiated from the outside of the room 90 with a light 96 (product name: HL01W, manufactured by Pyphotonics) so that the incident angle θ1 of light with respect to the glass window 92 was 50 °.

Next, the illuminance on the lower surface (ceiling surface) of the ceiling portion 94 was measured with a plurality of illuminance meters 97. Thereby, the reference illuminance [lux] before the daylighting film 1 was attached to the glass window 92 was measured.

Next, each daylighting film was attached to the inner surface of the glass window 92 after the release liner was peeled off. The support was held on the daylighting layer without being peeled off.

Then, white light was irradiated from the outside of the room 90 with a light 96 so that the incident angle θ1 of light with respect to the daylighting film 1 (glass window 92) was 50 °.

Next, the illuminance on the lower surface (ceiling surface) of the ceiling portion 94 was measured with a plurality of illuminance meters 97. Thereby, the measurement illuminance [lux] in a state where the daylighting film 1 was attached to the glass window 92 was measured.

And the illuminance change (= measurement illuminance / reference illuminance) in each illuminance meter 97 was calculated. The results are shown in Table 3.

In Table 3, among the three columns 95A, the left column 95A is the left column, the center column 95A is the center column, and the right column 95A is the right column. In addition, the six illuminance meters 97 in each row were designated as a first illuminance meter to a sixth illuminance meter in order from the front side (glass window 92 side).

<Measurement of transmittance and haze value>
Each of the daylighting films obtained in Examples 10 to 12 was attached to the inner surface of the glass window after peeling the release liner. The support was held on the daylighting layer without being peeled off.

The transmittance and haze value were measured with a haze meter (trade name: HR-100, manufactured by Murakami Color Research Laboratory Co., Ltd.). The results are shown in Table 4.

In Table 4, the PET film is PET, the acrylic resin film is acrylic resin, and the PET film provided with a hard coat layer and an antireflection layer is PET + HC + AR.

Although the above description is provided as an exemplary embodiment of the present invention, this is merely an example and should not be construed as limiting. Variations of the present invention apparent to those skilled in the art are within the scope of the following claims.

The daylighting film of the present invention is suitably used, for example, as a daylighting film used for daylighting of buildings.

DESCRIPTION OF SYMBOLS 1 Daylighting film 2 Daylighting layer 3 Support body 9 Transparent part 10 Cavity part

Claims

A support layer;
A daylighting layer laminated on the support layer,
The daylighting layer is
A plurality of transparent portions arranged at intervals in a first direction orthogonal to the thickness direction of the daylighting layer;
A plurality of gaps arranged one by one between the transparent parts adjacent to each other among the plurality of transparent parts,
Each of the plurality of voids extends over the entire thickness direction in the daylighting layer, and extends over the entire second direction perpendicular to both the thickness direction and the first direction.
The volume ratio of the plurality of transparent portions to the daylighting layer is 93% by volume or more,
The daylighting film, wherein a ratio of each dimension of the plurality of gaps in the first direction to a dimension of each of the plurality of transparent parts in the first direction is 0.1 or less.
2. The daylighting film according to claim 1, wherein both end faces of each of the plurality of transparent portions in the first direction are substantially parallel to each other.
2. The daylighting film according to claim 1, wherein at least one of both end faces in the first direction of each of the plurality of transparent portions has an uneven shape.
The daylighting film according to claim 2, wherein end faces in the first direction of the plurality of transparent portions are inclined with respect to the thickness direction.
2. The daylighting film according to claim 1, wherein in the support layer, a refractive index of a material constituting a surface opposite to the daylighting layer is 1.35 or more and 1.55 or less.