WO2015118944A1

WO2015118944A1 - Optical film

Info

Publication number: WO2015118944A1
Application number: PCT/JP2015/051415
Authority: WO
Inventors: 和也藤岡
Original assignee: 日東電工株式会社
Priority date: 2014-02-04
Filing date: 2015-01-20
Publication date: 2015-08-13
Also published as: JP2015146004A

Abstract

　This optical film is provided with a plurality of reflection layers configured so as to reflect light. The plurality of reflection layers respectively extend in a first direction orthogonal to the thickness direction of the optical film, the plurality of reflection layers being arranged parallel and spaced apart from one another in a second direction orthogonal to both the thickness direction and the first direction. The plurality of reflection layers include reflection layers arranged to be adjacently spaced apart at a first spacing, and reflection layers arranged to be adjacently spaced apart at a second spacing the dimension of which in the second direction is different than that of the first spacing.

Description

Optical film

The present invention relates to an optical film, and more particularly to an optical film used for daylighting a building such as a house.

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

Therefore, an optical member that can change the traveling direction of light by optical action such as light refraction, diffraction, or reflection is attached to a window, etc., and sunlight is efficiently introduced into the room to improve indoor brightness. Various attempts have been made to achieve this.

As such an optical member, for example, a transparent plastic plate in which a plurality of slits extending in the horizontal direction are arranged at regular intervals in the vertical direction has been proposed (for example, see Patent Document 1).

And such a plastic plate is installed in a window of a house, for example, and reflects and refracts sunlight incident from the outside through the window to collect light.

JP 2000-268610 A

However, the altitude of the sun changes with the passage of time during the day, and if the date (season) is different, it is different even at the same time. Therefore, the incident angle of sunlight changes depending on the time of day and the date (season).

However, the plastic plate described in Patent Document 1 can extract sunlight and improve indoor brightness when the solar altitude is within a specific range. If it is out of range, it may not be possible to efficiently illuminate and the indoor brightness may not be sufficiently secured.

Therefore, an object of the present invention is to provide an optical film that can efficiently and stably illuminate even if the altitude of the sun changes and can improve the brightness of the entire room.

The optical film of the present invention is an optical film including a plurality of reflective layers configured to reflect light, and each of the plurality of reflective layers is in a first direction orthogonal to the thickness direction of the optical film. Extending in a second direction perpendicular to both the thickness direction and the first direction, the plurality of reflective layers are arranged adjacent to each other at a first interval. And a reflective layer disposed adjacent to each other with a second interval having a different dimension in the second direction from the first interval.

According to such a configuration, since the optical film includes a plurality of reflective layers, for example, if the optical film is installed on a window of a house such that the second direction is along the vertical direction, a plurality of the optical films are provided. The reflection layer reflects sunlight from the outside upward and takes light.

However, whether or not the optical film including a plurality of reflective layers can sufficiently improve the indoor brightness when the altitude of the sun is changed depends on whether the reflective layers adjacent to each other in the plurality of reflective layers. It depends on the interval between them (the pitch of the plurality of reflective layers).

Specifically, when the interval between the reflective layers adjacent to each other is small, when the incident angle of sunlight with respect to the optical film is small (when the altitude of the sun is low), most of the incident light is reflected by the reflective layer. When the incident angle of sunlight with respect to the optical film is large (when the altitude of the sun is high), most of the incident light is reflected upward by the reflection layer and then reflected. The light is reflected again by the reflective layer disposed above the layer and travels downward. Here, when the sunlight introduced into the room travels downward, the vicinity of the window is illuminated, but the brightness of other parts in the room cannot be sufficiently ensured. On the other hand, when the sunlight introduced into the room progresses upward, the introduced sunlight is reflected by the ceiling or the like and reaches farther from the window, thereby improving the overall brightness of the room. Can do.

In other words, when the interval between the reflective layers adjacent to each other is small, if the incident angle of the sunlight to the optical film is small, the brightness of the entire room can be improved, but the incident angle of the sunlight to the optical film is If it is large, the brightness of the entire room cannot be improved.

In addition, when the interval between the reflective layers adjacent to each other is large, if the incident angle of sunlight with respect to the optical film is small, most of the incident light passes between the adjacent reflective layers and proceeds downward. When the incident angle of sunlight with respect to the optical film is large, most of the incident light is reflected by the reflective layer and proceeds upward.

That is, when the interval between the reflective layers adjacent to each other is large, if the incident angle with respect to the optical film of sunlight is large, the brightness of the entire room can be improved, but the incident angle with respect to the optical film of sunlight is If it is small, the brightness of the entire room cannot be improved.

Therefore, if the distance between the reflective layers adjacent to each other in the plurality of reflective layers (the pitch of the plurality of reflective layers) is constant, it is not possible to perform stable lighting when the altitude of the sun changes.

However, according to the above-described configuration, the plurality of reflective layers includes the reflective layer arranged to be adjacent to each other with the first interval, and the second interval having different dimensions in the second direction from the first interval. And a reflective layer disposed so as to be adjacent to each other.

Therefore, even if the altitude of the sun changes, the reflective layers adjacent to each other with an interval suitable for the incident angle of the sunlight with respect to the optical film, specifically, the first and second intervals are separated from each other. Adjacent reflective layers reflect incident light and travel upward.

As a result, even if the altitude of the sun changes, the light can be efficiently and stably lit, and the brightness of the entire room can be improved.

Further, it is preferable that the first interval is 1.25 times to 10 times the second interval.

According to such a configuration, since the first interval is 1.25 to 10 times the second interval, the incident light is reliably reflected even if the altitude of the sun changes greatly. , It can be made to progress upward.

According to the optical film of the present invention, even if the altitude of the sun changes, the light can be efficiently and stably lit, and the brightness of the entire room can be improved.

FIG. 1 is a perspective view of a daylighting film as a first embodiment of the optical film of the present invention. FIG. 2 is a side view of the daylighting film shown in FIG. 1 as viewed from the first surface direction. FIG. 3 is a perspective view of the first unit film and the second unit film according to the daylighting film shown in FIG. FIG. 4 illustrates 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 first unit film and the second unit film shown in FIG. It is explanatory drawing for doing. FIG. 5 is an explanatory diagram for explaining a process in which the side layer of the laminate is continuously cut after the support drawn from the support roll is attached to the side of the laminate shown in FIG. It is. FIG. 6 is a perspective view of the daylighting layer and the support shown in FIG. FIG. 7A is a schematic explanatory diagram for explaining a state in which the daylighting film shown in FIG. 1 is attached to a glass window, and shows a case where the altitude of the sun is relatively low. FIG. 7B is a schematic explanatory diagram for explaining a state in which the daylighting film shown in FIG. 1 is attached to the glass window, and shows a case where the altitude of the sun is relatively high. FIG. 8 is a side view of the daylighting film as the second embodiment of the present invention viewed from the first surface direction. FIG. 9 is a side view of a daylighting film as a third embodiment of the present invention viewed from the first surface direction. FIG. 10 is a perspective view of a daylighting film as the fourth and fifth embodiments of the present invention. FIG. 11 is a perspective view of the first unit film and the second unit film according to the daylighting film shown in FIG. FIG. 12 is an explanatory diagram for explaining a method of measuring the reference illuminance and the measured illuminance in Examples and Comparative Examples. FIG. 13 is a diagram showing the change in the direction change efficiency with respect to the incident angle of light in the daylighting films of Examples and Comparative Examples.

1. Configuration of Daylighting Film A daylighting film 1 as an example of an optical film is formed in a flexible sheet shape (film shape) as shown in FIG. 1, and is rectangular when viewed from the thickness direction X of the daylighting film 1. It is formed into a shape.

The dimension in the thickness direction X 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.

Moreover, although the size of the lighting film 1 is suitably changed according to a use purpose etc., the dimension of the 1st surface direction Y (an example of 1st direction) orthogonal to the thickness direction X of the lighting film 1 is 10 cm, for example. As mentioned above, Preferably, it is 60 cm or more, for example, 200 cm or less, Preferably, it is 100 cm or less. The dimension of the second surface direction Z (an example of the second direction) orthogonal to both the thickness direction X and the first surface direction Y of the daylighting film 1 is, for example, 5 cm or more, preferably 10 cm or more, for example, 150 cm. Hereinafter, it is preferably 80 cm or less.

Moreover, the lighting film 1 is provided with the lighting layer 2, the support body 3, and the peeling body 4, as shown in FIG.

In the following description, the lower side of the paper surface in FIG. 2 is one of the second surface direction Z, the upper side of the paper surface in FIG. 2 is the other of the second surface direction Z, and the left side of the paper surface in FIG. 2 is the other side in the thickness direction X.

The daylighting layer 2 is a substantially central portion in the thickness direction X of the daylighting film 1 and includes a plurality of transparent layers 9 and a plurality of air layers 10 as an example of a reflective layer.

The plurality of transparent layers 9 are arranged in parallel in the second surface direction Z with a slight gap (air layer 10) therebetween. As shown in FIGS. 1 and 2, each of the plurality of transparent layers 9 is formed in a substantially bowl shape and extends over the entire first surface direction Y of the daylighting layer 2. Further, one surface and the other surface in the second surface direction Z of the transparent layer 9 are along the thickness direction X.

The transparent layer 9 is configured to transmit light, and is preferably formed from a transparent resin material from the viewpoint of ease of processing.

Examples of the transparent resin material include known resin materials. Examples of the resin material include 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 and polyvinyl chloride are preferable, and polyvinyl chloride is more preferable. Such resin materials may be used alone or in combination of two or more.

The light transmittance of the transparent layer 9 is, for example, 80% or more, preferably 90% or more, more preferably 92% with respect to light having a wavelength of 440 to 600 nm when the thickness of the transparent layer 9 is 100 μm. % Or more, for example, 98% or less.

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

More specifically, the plurality of transparent layers 9 include a first transparent layer 20 and a second transparent layer 21 having different dimensions in the second surface direction Z. In the first embodiment, the plurality of transparent layers 9 include only the plurality of first transparent layers 20 and the plurality of second transparent layers 21.

As shown in FIG. 2, the first transparent layer 20 and the second transparent layer 21 are alternately arranged in the second surface direction Z so as to be continuous with a slight distance (air layer 10) therebetween. .

The first transparent layer 20 has a dimension in the second surface direction Z larger than that of the second transparent layer 21. Specifically, the dimension in the second surface direction Z of the first transparent layer 20 is, for example, 30 μm or more, preferably 50 μm or more, for example, 500 μm or less, preferably 300 μm or less. The dimension of the first transparent layer 20 in the second surface direction Z is, for example, 1.25 times or more the dimension of the second transparent layer 21 in the second surface direction Z, preferably from the viewpoint of the stability of lighting. 1.5 times or more, for example, 10 times or less, preferably 4 times or less.

The dimension in the thickness direction X of the first transparent layer 20 is, for example, 30 μm or more, preferably 50 μm or more, for example, 1500 μm or less, preferably 500 μm or less. The dimension in the second surface direction Z of the first transparent layer 20 is, for example, 20% or more with respect to 100% in the thickness direction X of the first transparent layer 20, and preferably 40% from the viewpoint of lighting. For example, it is 1000% or less, and preferably 500% or less from the viewpoint of daylighting.

The dimension in the second surface direction Z of the second transparent layer 21 is, for example, 20 μm or more, preferably 40 μm or more, for example, 400 μm or less, preferably 200 μm or less, and the dimension in the thickness direction X of the second transparent layer 21. These are the same as the dimension of the first transparent layer 20 in the thickness direction X.

Further, the dimension in the second surface direction Z of the second transparent layer 21 is, for example, 10% or more with respect to 100% in the thickness direction X of the second transparent layer 21, and preferably 30% from the viewpoint of lighting. For example, 100% or less, and preferably 80% or less from the viewpoint of daylighting.

The plurality of air layers 10 are formed as gaps between adjacent transparent layers 9 among the plurality of transparent layers 9. That is, in the first embodiment, the plurality of air layers 10 are formed as gaps between the first transparent layer 20 and the second transparent layer 21 adjacent to each other, and the first air layer 23 and the second air Layer 24.

The first air layer 23 is a gap between the first transparent layer 20 and the second transparent layer 21 that is adjacent to the first transparent layer 20 on the other side in the second surface direction Z with a gap. Is formed. That is, the first air layer 23 is partitioned by the other surface of the first transparent layer 20 in the second surface direction Z and the one surface of the second transparent layer 21 in the second surface direction Z.

The second air layer 24 is formed as a gap between the first transparent layer 20 and the second transparent layer 21 adjacent to the first transparent layer 20 with a gap in one of the second surface directions Z. Has been. That is, the second air layer 24 is partitioned by one surface of the first transparent layer 20 in the second surface direction Z and the other surface of the second transparent layer 21 in the second surface direction Z.

Therefore, each of the first air layer 23 and the second air layer 24 extends over the entire first surface direction Y of the daylighting layer 2 as shown in FIG. 1 and FIG. The boundary between each of the two air layers 24 and each of the first transparent layer 20 and the second transparent layer 21 (a boundary 15, a boundary 16, and a boundary 17 described later) is along the first surface direction Y and the thickness direction X. Yes.

The dimension of the first air layer 23 in the second surface direction Z is, for example, 0.1 μm or more, preferably 1 μm or more, for example, 20 μm or less, preferably 10 μm or less. With respect to the dimension in the dihedral direction Z, for example, it is 1/5000 or more, preferably 1/300 or more, for example, 2/3 or less, preferably 1/3 or less. The dimension of the second air layer 24 in the second surface direction Z is the same as the dimension of the first air layer 23 in the second surface direction Z.

In addition, as shown in FIG. 2, the first air layer 23 and the second air layer 24 disposed on one side in the second surface direction Z with respect to the first air layer 23 are the first transparent layer. 20 are sandwiched in the second surface direction Z, and are adjacent to each other with a first interval S1.

The dimension in the second surface direction Z of the first interval S1 is, for example, 25 μm or more, preferably 50 μm or more, for example, 500 μm or less, preferably 300 μm or less. In the present embodiment (the first to fifth embodiments), the dimension in the second surface direction Z of the first interval S1 is the same as the dimension in the second surface direction Z of the first transparent layer 20. .

Further, the first interval S1 is, for example, 1.25 times or more with respect to the second interval S2, preferably 1.5 times or more, for example, 10 times or less, preferably from the viewpoint of lighting stability. 4 times or less.

Further, the first air layer 23 and the second air layer 24 disposed on the other side in the second surface direction Z with respect to the first air layer 23 include the second transparent layer 21 in the second surface direction Z. And are adjacent to each other with a second interval S2.

The dimension in the second surface direction Z of the second distance S2 is different from the dimension in the first distance S1 and the second surface direction Z, for example, 20 μm or more, preferably 40 μm or more, for example, 400 μm or less, preferably Is 200 μm or less. In the present embodiment (the first to fifth embodiments), the dimension of the second interval S2 in the second surface direction Z is the same as the dimension of the second transparent layer 21 in the second surface direction Z. .

That is, the plurality of air layers 10 are adjacent to each other with the first air layer 23 and the second air layer 24 adjacent to each other at the first interval S1 and at the first interval adjacent to each other at the second interval S2. It includes an air layer 23 and a second air layer 24, and is arranged with either one of the first interval S1 and the second interval S2.

Thereby, in the daylighting layer 2, the pattern P1 including the two transparent layers 9 and the two air layers 10 is sequentially and repeatedly arranged in the second surface direction Z. Specifically, in the pattern P1, the first transparent layer 20, the first air layer 23, the second transparent layer 21, and the second air layer 24 are sequentially arranged from one side to the other side in the second surface direction Z.

The support 3 is one side portion in the thickness direction X of the daylighting film 1 and is adjacent to one side in the thickness direction X with respect to the daylighting layer 2. The support 3 includes a substrate 12 and an adhesive layer 11.

The base material 12 is one side portion in the thickness direction X of the support 3 and is configured to transmit light. Examples of the substrate 12 include a substrate such as a PET film, a fluorine-based polymer (for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer). And low adhesive substrates made of nonpolar polymers (for example, olefinic resins such as polyethylene and polypropylene).

Among such base materials 12, preferably, a PET film and a low-adhesion base material made of a nonpolar polymer are mentioned, and a polypropylene film is more preferred.

The dimension of the base material 12 in the thickness direction X 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 12 is, for example, 85% or more, preferably 90% or more, with respect to light having a wavelength of 440 to 600 nm when the dimension in the thickness direction X of the substrate 12 is 50 μm. Preferably, it is 92% or more, for example, 98% or less.

The pressure-sensitive adhesive layer 11 is the other side portion in the thickness direction X of the support 3 and is interposed between the base material 12 and the daylighting layer 2. Thereby, the daylighting layer 2 and the base material 12 are adhered.

Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 11 include known pressure-sensitive adhesives such as an epoxy-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and an ultraviolet curable pressure-sensitive adhesive. The pressure-sensitive adhesive preferably transmits light. Moreover, the adhesive layer 11 can also be comprised from a well-known double-sided adhesive tape.

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.

The dimension in the thickness direction X of the pressure-sensitive adhesive layer 11 is, for example, 1 μm or more, preferably 5 μm or more, for example, 100 μm or less, preferably 40 μm or less. In addition, when the base material 12 itself is sticky, the pressure-sensitive adhesive layer 11 is not necessary in the support 3.

The peeling body 4 is the other side portion in the thickness direction X of the daylighting film 1 and is adjacent to the other side in the thickness direction X with respect to the daylighting layer 2. The release body 4 includes a release material 14 and an adhesive layer 13.

The release material 14 is the other side portion in the thickness direction X of the release body 4 and is configured to transmit light. Examples of the release material 14 include a substrate similar to the substrate 12, preferably a PET film and a low-adhesive substrate made of a nonpolar polymer, and more preferably a PET film. .

The dimension in the thickness direction X of the release material 14 is, for example, 10 μm or more, preferably 40 μm or more, for example, 100 μm or less, preferably 60 μm or less. The light transmittance of the release material 14 is, for example, 60% or more, preferably 80% or more with respect to light having a wavelength of 440 to 600 nm when the dimension in the thickness direction X of the release material 14 is 50 μm. Preferably, it is 92% or more, for example, 98% or less.

Although not shown, a release treatment layer (not shown) is provided on one surface in the thickness direction X of the release material 14.

The pressure-sensitive adhesive layer 13 is one side portion in the thickness direction X of the release body 4 and is interposed between the release treatment layer (not shown) of the release material 14 and the daylighting layer 2. Thereby, the daylighting layer 2 and the release material 14 are bonded.

Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 13 include the same pressure-sensitive adhesive as the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 11. Among such 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 X of the pressure-sensitive adhesive layer 13 is, for example, 5 μm or more, preferably 20 μm or more, for example, 100 μm or less, preferably 60 μm or less.
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, as shown in FIG. 3, first, the first unit film 29 corresponding to the first transparent layer 20 and the second unit film 30 corresponding to the second transparent layer 21, respectively, Prepare multiple sheets.

To prepare the first unit film 29, for example, after preparing a first processed sheet made of the first transparent layer 20, the first unit film 29 having a predetermined shape is cut out from the first processed sheet. Examples of the method for cutting out the first unit film 29 from the first processed sheet include known processing methods such as cutting and punching.

Further, in order to prepare the second unit film 30, for example, after preparing a second processed sheet made of the second transparent layer 21, the second unit film 30 having a predetermined shape is cut out from the second processed sheet. Examples of the method for cutting out the second unit film 30 from the second processed sheet include the above-described processing methods.

The shape of each of the first unit film 29 and the second unit film 30 is not particularly limited, and the first unit film 29 and the second unit film 30 are, for example, viewed from their thickness direction by the above-described cutting method. , Polygonal or circular, preferably rectangular or circular, particularly preferably circular.

Further, the sizes of the first unit film 29 and the second unit film 30 are appropriately changed according to the purpose of use. Specifically, when each of the first unit film 29 and the second unit film 30 is circular when viewed in the thickness direction, the diameter is, for example, 10 cm to 1 m (100 cm), which is preferable from the viewpoint of workability. Is between 10 cm and 50 cm.

Each of the first unit film 29 and the second unit film 30 is a plurality of sheets, for example, 100 sheets or more, preferably 5000 sheets or more, for example, 30000 sheets or less, preferably 15000 sheets or less, more preferably Prepare 10,000 sheets or less.

In order to prepare a plurality of the first unit films 29, for example, the first processed sheet is formed large so that the plurality of first unit films 29 can be cut out, and the first unit film 29 is formed from the first processed sheet. A plurality of first processed sheets may be cut out, and a plurality of first processed sheets may be prepared, and the first unit film 29 may be cut out one by one from each first processed sheet.

Further, in order to prepare a plurality of second unit films 30, even when a plurality of second unit films 30 are cut out from a large second processed sheet, as in the case of preparing a plurality of first unit films 29. The second unit film 30 may be cut out one by one from the plurality of second processed sheets. Each of the plurality of first unit films 29 and second unit films 30 is preferably formed in the same shape and size.

Next, as shown in FIG. 4, a plurality of first unit films 29 and a plurality of second unit films 30 are laminated in the thickness direction without sandwiching an adhesive layer to prepare a laminate 31.

More specifically, the first unit film 29 and the second unit film 30 are laminated in the thickness direction so that the first unit film 29 and the second unit film 30 are alternately overlapped. That is, the thickness direction of the first unit film 29, the thickness direction of the second unit film 30, and the stacking direction of the laminate 31 are the same direction.

Here, in the laminated body 31, a slight amount of air is interposed between the first unit film 29 and the second unit film 30 that are adjacent to each other in the laminating direction. Adjacent first unit film 29 and second unit film 30 are partitioned.

In FIG. 4, for convenience, the number of each of the plurality of first unit films 29 and the plurality of second unit films 30 is omitted, and the laminated body 31 includes six first unit films 29, Although it is described that the second unit film 30 is composed of six sheets, in practice, the laminate 31 is, for example, 100 to 30000 sheets, preferably 5000 to 15000 sheets, and more preferably 5000. 1 to 10000 first unit films 29 and, for example, 100 to 30000 sheets, preferably 5000 to 15000 sheets, and more preferably 5000 to 10000 second unit films 30 are laminated to form. Has been.

When each first unit film 29 and each second unit film 30 are formed in the same shape and size, when the plurality of first unit films 29 and the plurality of second unit films 30 are projected in the stacking direction. Are laminated so that their outer peripheral edges coincide with each other.

As described above, the columnar (block-shaped) stacked body 31 extending in the stacking direction is formed. For example, when the first unit film 29 and the second unit film 30 are rectangular when viewed from the thickness direction, a prismatic laminate 31 is formed, and the first unit film 29 and the second unit film 30 are viewed from the thickness direction. In the case of a circular shape, a cylindrical laminated body 31 is formed.

The height (length in the stacking direction) of the stacked body 31 is, for example, 1 cm or more, preferably 5 cm or more, more preferably 10 cm or more, for example, 200 cm or less, preferably 100 cm or less, more preferably 50 cm or less. is there.

Next, after the support 3 is attached to the side surface 32 (surface extending along the stacking direction) of the stacked body 31 so as to be along the stacking direction, the side layer 33 of the stacked body 31 to which the support 3 is bonded is attached. The first unit film 29 and the second unit film 30 are cut so as to be aligned in the stacking direction of the stacked body 31.

The cutting method for cutting the side layer 33 of the laminate 31 is not particularly limited as long as the side layer 33 supported by the support 3 can be cut out from the laminate 31.

Among such cutting methods, from the viewpoint of productivity, the laminated body 31 is formed in a cylindrical shape, and the side layer 33 of the laminated body 31 is continuously cut out by the cutting device 40 as shown in FIG. Is preferred.

The cutting device 40 includes a rotating shaft 41, a pair of holding members 42, and a cutting blade 35.

The rotary shaft 41 has a substantially cylindrical shape and is configured to be rotatable about the axis. A long and flat belt-like support 3 is wound around the rotary shaft 41. Specifically, the long and flat support 3 is wound around the rotary shaft 41 in a spiral shape so that the pressure-sensitive adhesive layer 11 is positioned radially inward of the rotary shaft 41 with respect to the base material 12. Thus, the support 3 is configured as a support roll 45 centered on the rotation shaft 41. In addition, the peeling process layer (not shown) is provided in the surface on the opposite side to the adhesive layer 11 in the base material 12. As shown in FIG. The peeling force of the base material 12 by a peeling process layer is adjusted suitably.

In the support roll 45, the support 3 is disposed adjacent to the radial direction of the rotation shaft 41, and the adhesive layer 11 and the base material 12 are sequentially and repeatedly disposed. In addition, as described above, since the release treatment layer is provided on the surface of the base material 12 opposite to the pressure-sensitive adhesive layer 11, in the radial direction of the rotating shaft 41, between the supports 3 adjacent to each other, A release treatment layer is interposed between the pressure-sensitive adhesive layer 11 of the support 3 disposed on the radially outer side and the base material 12 of the support 3 disposed on the radially inner side.

The pair of holding members 42 are arranged with respect to the support roll 45 at an interval in the radial direction of the support roll 45. Each of the pair of holding members 42 has a substantially disc shape, and is configured to be rotatable about its axis.

Further, the pair of holding members 42 are arranged at intervals from each other in the axial direction of the holding member 42. Then, the pair of holding members 42 press the substantially cylindrical laminated body 31 from both sides in the laminating direction to hold the laminated body 31.

As a pressurizing condition, the pressure from one side (the other side) in the stacking direction with respect to the stacked body 31 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. is there.

In addition, each holding member 42 is arranged so that the axis line of the laminated body 31 coincides with the laminated body 31 held.

The cutting blade 35 is disposed along the stacking direction with respect to the side surface 32 of the stacked body 31 held by the pair of holding members 42, and the tip of the cutting blade 35 is placed on the side surface 32 of the stacked body 31. It is in contact from a substantially tangential direction.

In addition, the cutting blade 35 maintains the state in which the tip of the cutting blade 35 is in contact with the side surface 32 of the laminated body 31 as the diameter of the laminated body 31 decreases as the cutting process proceeds. It is configured to approach.

In order to continuously cut out the side layer 33 of the laminate 31 with such a cutting device 40, first, the laminate 31 held by the pair of holding members 42 is supported on the support 3 drawn from the support roll 45. Affixed to the side surface 32.

More specifically, the support 3 is drawn toward the tangential direction of the laminate 31 so that the pressure-sensitive adhesive layer 11 of the drawn support 3 adheres to the side surface 32 of the laminate 31, and the central angle in the laminate 31 is For example, it is attached to the side surface 32 of the laminate 31 in the range of 90 ° to 270 °, preferably in the range of 120 ° to 240 °.

Next, the pair of holding members 42 are rotated in the counterclockwise direction when viewed from one axial direction (the front side in FIG. 5) of the holding member 42 by a driving force from a driving source such as a motor included in the cutting device 40. To drive.

Then, the laminate 31 held by the pair of holding members 42 rotates about the axis, and the support roll 45 is driven about the axis of the rotation shaft 41.

Thereby, the side layer 33 of the laminated body 31 to which the support 3 is attached is continuously cut out by the cutting blade 35 like wig peeling. In addition, the thickness of the side layer 33 to be cut out can be appropriately adjusted by the arrangement and angle of the cutting blade 35 with respect to the laminated body 31 when the laminated body 31 is cut.

As described above, as shown in FIG. 6, the side layer 33 in which the support 3 is bonded to one surface continuously from the laminate 31, that is, the lighting layer 2 in which the support 3 is bonded to one surface is formed. , Cut into long and flat strips.

Next, the peeling body 4 is attached to the other surface of the daylighting layer 2. Specifically, the pressure-sensitive adhesive layer 13 of the release body 4 is adhered to the other surface of the daylighting layer 2.

As a result, as shown in FIG. 2, the support 3 and the release body 4 are attached to the daylighting layer 2 so as to sandwich the daylighting layer 2, and the daylighting film 1 is prepared.

Thereafter, the daylighting film 1 is cut into a predetermined shape and size. Examples of the method for cutting the daylighting film 1 include known processing methods such as cutting and punching.
3. Next, a usage mode of the daylighting film 1 will be described.

As shown in FIGS. 7A and 7B, the daylighting film 1 is attached to the inner side surface of a glass window 51 provided in a building such as a house 50.

In order to attach the daylighting film 1 to the inner surface of the glass window 51, first, the release material 14 is peeled off. And the lighting film 1 is arrange | positioned so that the 2nd surface direction Z may follow an up-down direction, and the exposed adhesive layer 13 is adhere | attached on the inner surface of the glass window 51. FIG. Thus, the daylighting film 1 is attached to the inner surface of the glass window 51.

In the state where the daylighting film 1 is attached to the glass window 51 as described above, as shown in FIG. 7A, when the altitude of the sun is relatively low, the sunlight L is outside the house 50 through the glass window 51. When incident from (outdoors), a part of the light L1 in the sunlight L passes through the first transparent layer 20 linearly and travels toward the floor 52 of the house 50. In addition, light L 2 of another part of sunlight L enters the second transparent layer 21 and then reaches the boundary 15 between the second transparent layer 21 and the first air layer 23. Then, the light L2 of the other part is reflected by the boundary 15 (first air layer 23), and the traveling direction thereof is changed so as to be directed upward, from the second transparent layer 21 toward the ceiling portion 53 of the house 50. And proceed. Then, the light L2 of another part is reflected again by the ceiling part 53, for example, and reaches | attains far from the wall part 54 in which the glass window 51 is installed in the house 50 rather than some light L1.

In addition, as shown in FIG. 7B, when the solar altitude is relatively high, when sunlight L enters from outside the house 50 (outdoors) through the glass window 51, some of the light in the sunlight L L3 is incident on the second transparent layer 21, is reflected by the boundary 15 (first air layer 23), travels upward in the second transparent layer 21, and the second transparent layer 21 and the second transparent layer 21 The boundary 16 with the air layer 24 is reached. Then, a part of the light L3 is reflected by the boundary 16 (second air layer 24), travels downward, and travels from the second transparent layer 21 toward the floor 52 of the house 50. In addition, the light L4 of the other part of the sunlight L enters the first transparent layer 20 and then reaches the boundary 17 between the first transparent layer 20 and the second air layer 24. Then, the light L4 of the other part is reflected by the boundary 17 (second air layer 24), and the traveling direction thereof is changed so as to be directed upward, from the first transparent layer 20 toward the ceiling portion 53 of the house 50. And proceed. Then, the light L4 of another part is reflected again by the ceiling part 53, for example, and reaches | attains far from the wall part 54 rather than some light L3 in the house 50. FIG.

Such a daylighting film 1 includes a plurality of air layers 10 as shown in FIGS. 7A and 7B. Therefore, if the lighting film 1 is affixed to the glass window 51 of the house 50 so that the second surface direction Z is along the vertical direction, the plurality of air layers 10 reflect the sunlight L from the outdoors upward. And daylight.

As shown in FIG. 2, the plurality of air layers 10 are separated from each other by the first air layer 23 and the second air layer 24 that are arranged adjacent to each other with a first interval S1 therebetween. The first air layer 23 and the second air layer 24 are arranged so as to be adjacent to each other.

Therefore, even if the altitude of the sun changes, the adjacent air layer 10 with an interval suitable for the incident angle of the sunlight with respect to the daylighting film 1 reflects the incident light and travels upward.

Specifically, when the altitude of the sun is relatively low, as shown in FIG. 7A, the first air layer 23 reflects the light L2 of the other part of the sunlight L, and the altitude of the sun is relative. If it is high, the second air layer 24 reflects the light L4 of the other part of the sunlight L as shown in FIG. 7B.

Further, the first interval S1 is 1.25 to 10 times the second interval S2. Therefore, even if the altitude of the sun changes greatly, the incident light (sunlight L) can be reliably reflected and advanced upward.
4). Second Embodiment Next, a second embodiment of the daylighting film 1 of the present invention will be described with reference to FIG. 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 plurality of air layers 10 include an air layer 10 adjacent to each other with a first interval S 1 and an air layer 10 adjacent to each other with a second interval S 2. Including. However, if the plurality of air layers 10 include at least the air layers 10 that are adjacent to each other with a first interval S1 and the air layers 10 that are adjacent to each other with a different interval from the first interval S1, It is not limited.

In the second embodiment, as shown in FIG. 8, a plurality of air layers 10 are formed into air layers 10 that are adjacent to each other with a first interval S 1 and air layers 10 that are adjacent to each other with a second interval S 2. In addition, it includes air layers 10 that are adjacent to each other with a third interval S3.

The plurality of transparent layers 9 according to the second embodiment includes a plurality of third transparent layers 56 in addition to the plurality of first transparent layers 20 and the plurality of second transparent layers 21.

As shown in FIG. 8, the first transparent layer 20, the second transparent layer 21, and the third transparent layer 56 are arranged with a slight space (the air layer 10) therebetween in the second surface direction Z. They are sequentially and repeatedly arranged from one side of the two-plane direction Z to the other side.

The dimension in the second surface direction Z of the third transparent layer 56 is, for example, 25 μm or more, preferably 50 μm or more, for example, 500 μm or less, preferably 300 μm or less. The dimension in the second surface direction Z of the third transparent layer 56 is, for example, 1.25 times or more the dimension in the second surface direction Z of the second transparent layer 21, preferably from the viewpoint of the stability of lighting. 1.5 times or more, for example, 10 times or less, preferably 4 times or less. The dimension in the thickness direction X of the third transparent layer 56 is the same as the dimension in the thickness direction X of the first transparent layer 20.

Further, the dimension in the second surface direction Z of the third transparent layer 56 is, for example, 10% or more with respect to 100% in the thickness direction X of the third transparent layer 56, and preferably 30% from the viewpoint of lighting. As described above, for example, 400% or less, and preferably 200% or less from the viewpoint of daylighting.

Further, the plurality of air layers 10 according to the second embodiment include a plurality of third air layers 57 in addition to the plurality of first air layers 23 and the plurality of second air layers 24.

The third air layer 57 is formed as a gap between the third transparent layer 56 and the first transparent layer 20 that is adjacent to the third transparent layer 56 at the other side in the second surface direction Z with a gap. Has been. That is, the third air layer 57 is partitioned by the other surface of the third transparent layer 56 in the second surface direction Z and the one surface of the first transparent layer 20 in the second surface direction Z.

Therefore, the 3rd air layer 57 is extended over the whole 1st surface direction Y of the lighting layer 2, and the 3rd air layer 57 and the transparent layer 9 (each of the 1st transparent layer 20 and the 3rd transparent layer 56). Is along the first surface direction Y and the thickness direction X.

The dimensions of the third air layer 57 in the second surface direction Z and the dimensions in the thickness direction X are the same as the dimensions of the first air layer 23 in the second surface direction Z and the dimensions in the thickness direction X, respectively. .

Further, the third air layer 57 and the second air layer 24 disposed on one side in the second surface direction Z with respect to the third air layer 57 include the third transparent layer 56 in the second surface direction Z. And are adjacent to each other with a third interval S3.

The dimension in the second surface direction Z of the third interval S3 is, for example, 25 μm or more, preferably 50 μm or more, for example, 500 μm or less, preferably 300 μm or less. In the present embodiment (first to fifth embodiments), the dimension of the third interval S3 in the second surface direction Z is the same as the dimension of the third transparent layer 56 in the second surface direction Z. .

Further, the third interval S3 is, for example, 1.25 times or more with respect to the second interval S2, preferably 1.5 times or more, for example, 10 times or less, preferably from the viewpoint of lighting stability. 4 times or less.

Further, the third air layer 57 and the first air layer 23 disposed on the other side in the second surface direction Z with respect to the third air layer 57 include the first transparent layer 20 in the second surface direction Z. And arranged adjacent to each other with a first interval S1.

In other words, the plurality of air layers 10 are adjacent to each other with the first air layer 23 and the third air layer 57 adjacent to each other at the first interval S1, and at the first interval adjacent to each other at the second interval S2. It includes an air layer 23 and a second air layer 24, and a second air layer 24 and a third air layer 57 that are adjacent to each other with an interval of a third interval S3.

Thereby, in the daylighting layer 2, the pattern P2 including the three transparent layers 9 and the three air layers 10 is sequentially and repeatedly arranged in the second surface direction Z. Specifically, the pattern P2 includes the first transparent layer 20, the first air layer 23, the second transparent layer 21, the second air layer 24, the third transparent layer 56, and the third air layer 57 in the second surface direction Z. They are sequentially arranged from one to the other.

In order to manufacture the daylighting film 1 including the third transparent layer 56 and the third air layer 57, first, a third unit film (not shown) corresponding to the third air layer 57 is the same as the first unit film 29. A plurality of sheets (for example, 100 to 30000 sheets) are prepared by the above method.

Next, a plurality of first unit films 29, a plurality of second unit films 30, and a plurality of third unit films (not shown) are sequentially laminated in the thickness direction without sandwiching an adhesive layer, and laminated. Body 31 is prepared.

Then, as shown in FIGS. 4 and 5, for example, as in the first embodiment, the daylighting layer 2 with the support 3 attached to one surface is cut out into a long and flat strip shape from the laminate 31. A peeler 4 is attached to the other surface of the daylighting layer 2. Thereby, as shown in FIG. 8, the lighting film 1 provided with the 3rd transparent layer 56 and the 3rd air layer 57 is prepared.

According to the second embodiment, the plurality of air layers 10 are spaced apart from each other by the first air layer 23 and the third air layer 57 that are adjacent to each other with the first space S1 therebetween. The first air layer 23 and the second air layer 24 that are adjacent to each other, and the second air layer 24 and the third air layer 57 that are adjacent to each other with an interval of the third interval S3 included.

Therefore, even if the altitude of the sun changes, the adjacent air layer 10 with an interval suitable for the incident angle of the sunlight with respect to the daylighting film 1 reflects the incident light more reliably and moves upward. Proceed to. As a result, even if the altitude of the sun changes, it is possible to perform daylighting more efficiently and stably, and the brightness of the entire room can be reliably improved.

In the second embodiment, the interval between the first air layer 23 and the third air layer 57 adjacent to each other is defined as a first interval S1, and the first air layer 23 and the second air layer 24 adjacent to each other are The interval between the second air layer 24 and the third air layer 57 adjacent to each other is defined as a third interval S3. Any interval of the air layer 10 may be the first interval.

For example, when the interval between the first air layer 23 and the second air layer 24 adjacent to each other is the first interval, the interval between the first air layer 23 and the third air layer 57 adjacent to each other, One of the intervals between the second air layer 24 and the third air layer 57 adjacent to each other corresponds to the second interval, and the other corresponds to the third interval.

In addition, when the interval between the second air layer 24 and the third air layer 57 adjacent to each other is the first interval, the interval between the first air layer 23 and the third air layer 57 adjacent to each other, One of the intervals between the first air layer 23 and the second air layer 24 adjacent to each other corresponds to the second interval, and the other corresponds to the third interval.
5. 3rd Embodiment Next, with reference to FIG. 9, 3rd Embodiment of the daylighting film 1 of this invention is described. In the third 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 illustrated in FIG. 2, in the daylighting layer 2, the pattern P 1 including the first transparent layer 20, the first air layer 23, the second transparent layer 21, and the second air layer 24 is formed on the second surface. Although it arrange | positions sequentially and repeatedly in the direction Z, arrangement | positioning of the 1st transparent layer 20 and the 2nd transparent layer 21 is not specifically limited.

For example, in the third embodiment, as shown in FIG. 9, the daylighting layer 2 includes a unit U1 including a plurality of first transparent layers 20 arranged in parallel in the second surface direction Z with the air layer 10 therebetween. And a unit U2 composed of a plurality of second transparent layers 21 arranged in parallel in the second surface direction Z with the air layer 10 therebetween. The unit U1 and the unit U2 are arranged so as to be aligned in the second surface direction Z.

In order to prepare the daylighting film 1 including the unit U1 and the unit U2, as shown in FIG. 3, a plurality of first unit films 29 are laminated in the thickness direction without sandwiching an adhesive layer. A body (not shown) is prepared, and a plurality of second unit films 30 are laminated in the thickness direction without sandwiching the pressure-sensitive adhesive layer to prepare a second laminate (not shown).

And the 1st laminated body (not shown) and the 2nd laminated body (not shown) are laminated | stacked in those lamination directions, and the laminated body 31 is comprised.

Next, as shown in FIGS. 4 and 5, for example, as in the first embodiment, the daylighting layer 2 with the support 3 attached to one surface is cut out in a long and flat strip shape from the laminate 31. The peeler 4 is attached to the other surface of the daylighting layer 2. Thereby, as shown in FIG. 9, the lighting film 1 provided with the 3rd transparent layer 56 and the 3rd air layer 57 is prepared.

Also according to the third embodiment, it is possible to achieve the same operational effects as those of the first embodiment.
6). 4th Embodiment and 5th Embodiment Next, with reference to FIG. 10 and FIG. 11, 4th Embodiment and 5th Embodiment of the lighting film 1 of this invention are described. In the fourth embodiment and the fifth embodiment, members similar to those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

In the first embodiment, as shown in FIG. 2, the daylighting film 1 includes a plurality of air layers 10. In the fourth embodiment, as shown in FIG. 10, the daylighting film 1 includes a plurality of air layers 10. Instead of the layer 10, a plurality of low refractive layers 60 as an example of a reflective layer are provided.

In the fourth embodiment, the daylighting film 1 includes only the transparent layer 9 and the low refraction layer 60, and the transparent layer 9 and the low refraction layer 60 are sequentially and repeatedly repeated in the second surface direction Z. Has been placed.

The plurality of low-refractive layers 60 are arranged in parallel in the second surface direction Z with an interval (transparent layer 9) therebetween. Each of the plurality of low refractive layers 60 is disposed between the transparent layers 9 adjacent to each other in the plurality of transparent layers 9, and is formed in a thin film shape that extends over the entire first surface direction Y of the daylighting layer 2. In addition, one surface and the other surface of the low refractive layer 60 in the second surface direction Z are along the thickness direction X.

The low refractive layer 60 is configured to have a refractive index smaller than that of the transparent layer 9. The relative refractive index of the low refractive layer 60 is, for example, 1.20 or more, preferably 1.34 or more, for example 1.90 or less, preferably 1.80 or less with respect to the refractive index of air. For example, the refractive index of the transparent layer 9 is 0.05 or more, preferably 0.1 or more, such as 0.5 or less, preferably 0.3 or less. The refractive index can be measured with a prism coupler.

The low refractive layer 60 is preferably formed from a transparent resin material from the viewpoint of ease of processing. Examples of the transparent resin material include a fluorine-based resin and a silicone resin.

Among such transparent resin materials, fluorine resin is preferable. Such transparent resin materials may be used alone or in combination of two or more.

The dimension of the low refractive layer 60 in the second surface direction Z is, for example, 0.1 μm or more, preferably 1 μm or more, for example, 50 μm or less, preferably 10 μm or less.

The light transmittance of the low refractive layer 60 is, for example, 60% or more, preferably 80% or more, more preferably, for light having a wavelength of 440 to 600 nm when the thickness of the low refractive layer 60 is 100 μm. , 90% or more, for example, 98% or less.

In addition, among the plurality of low refractive layers 60, the low refractive layers 60 adjacent to each other with the first transparent layer 20 interposed therebetween are arranged with a first interval S1 therebetween, and are adjacent to each other with the second transparent layer 21 interposed therebetween. The low refractive layer 60 is disposed with a second interval S2.

In order to manufacture such a daylighting film 1, as shown in FIG. 11, the first unit film 29 including the first transparent layer 20 and the low refractive layer 60, the second transparent layer 21, and the low refractive layer 60 are provided. A plurality of second unit films 30 are prepared.

As a method for preparing such a first unit film 29, for example, after arranging the low refraction layer 60 on the surface of the first transparent layer 20 (one surface in the thickness direction) and preparing the first processed sheet, A method of cutting out the first unit film 29 having a predetermined shape from the processed sheet, a method of forming the first unit film 29 by disposing the low refractive layer 60 on the surface of the first transparent layer 20 processed into a predetermined shape, etc. Is mentioned. Moreover, as a method for preparing the second unit film 30, the same method as the method for preparing the first unit film 29 can be used except that the first transparent layer 20 is changed to the second transparent layer 21.

As a method of disposing the low refractive layer 60 on the surface of the first transparent layer 20 (or the second transparent layer 21), for example, a known film forming method is used to form the first transparent layer 20 (or the second transparent layer 21). Examples thereof include a method of forming the low refractive layer 60 on the surface and a method of simultaneously forming the first transparent layer 20 (or the second transparent layer 21) and the low refractive layer 60 by a coextrusion method.

Among such methods for disposing the low refractive layer 60 on the surface of the first transparent layer 20 (or the second transparent layer 21), a known film formation method is preferably used. A process, a wet process, etc. are mentioned, Preferably a wet process is mentioned.

Next, a plurality of first unit films 29 and a plurality of second unit films 30 are laminated in the thickness direction so that the first unit films 29 and the second unit films 30 are alternately overlapped, and a laminate 31 is obtained. To prepare.

In such a laminate 31, an adhesive layer may be provided between the first unit film 29 and the second unit film 30 adjacent to each other in the stacking direction, or an adhesive layer may not be provided. When an adhesive layer is not provided between the first unit film 29 and the second unit film 30 that are adjacent to each other in the stacking direction, the stacked body 31 is subjected to thermocompression bonding (heating press).

As described above, the columnar (block-shaped) stacked body 31 extending in the stacking direction is formed.

Next, as shown in FIGS. 4 and 5, in the same manner as in the first embodiment, the support body 3 is attached to the side surface 32 (surface extending along the stacking direction) of the stack body 31 along the stacking direction. After that, the side layer 33 of the laminate 31 to which the support 3 is attached is cut so that the first unit film 29 and the second unit film 30 are arranged in parallel in the lamination direction of the laminate 31.

Thus, the daylighting layer 2 having the support 3 attached to one surface is cut out from the laminate 31 in a long and flat band shape. Subsequently, the peeling body 4 is attached to the other surface of the daylighting layer 2.

Thus, the daylighting film 1 is prepared as shown in FIG.

According to the fourth embodiment, the plurality of low-refractive layers 60 are adjacent to each other with a low-refractive layer 60 adjacent to each other with an interval of the first interval S1, and to the low-refractive layers adjacent to each other with an interval of the second interval S2. Layer 60.

Therefore, even if the altitude of the sun changes, the adjacent low-refractive layer 60 with an interval suitable for the incident angle of the sunlight with respect to the daylighting film 1 reflects the incident light and travels upward. . As a result, also in the fourth embodiment, the same operational effects as those of the first embodiment described above can be achieved.

In the fifth embodiment, as shown in FIG. 10, the daylighting film 1 includes a plurality of metal layers 61 as an example of a reflective layer instead of the plurality of air layers 10. In the fifth embodiment, the daylighting film 1 includes only the transparent layer 9 and the metal layer 61, and the transparent layer 9 and the metal layer 61 are sequentially and repeatedly arranged in the second surface direction Z so as to be continuous. ing.

The plurality of metal layers 61 are arranged in parallel at intervals (transparent layer 9) in the second surface direction Z. Each of the plurality of metal layers 61 is disposed between the transparent layers 9 adjacent to each other in the plurality of transparent layers 9, and is formed in a thin film shape that extends over the entire first surface direction Y of the daylighting layer 2. In addition, one surface and the other surface of the metal layer 61 in the second surface direction Z are along the thickness direction X.

The metal layer 61 is configured to reflect light and is formed in a thin film shape from a metal material. Examples of the metal material forming the metal layer 61 include metal elements (for example, gold, silver, copper, iron, aluminum, chromium, nickel, etc.), alloys made of a plurality of metal elements, and the like. Silver, aluminum, and an alloy containing them are mentioned, More preferably, aluminum is mentioned. Such a metal material may be used as a single thin film, or two or more thin films may be laminated.

The dimension in the second surface direction Z of the metal layer 61 is not particularly limited as long as light can be sufficiently reflected, but is, for example, 20 nm or more, preferably 30 nm or more, for example, 10 μm (10 ⁴ nm). Hereinafter, it is preferably 1 μm (10 ³ nm) or less, more preferably 300 nm or less.

The reflectivity (incident angle 5 °) of the metal layer 61 is, for example, 70% or more, preferably 80% or more, for example 98% or less, preferably 95% with respect to light having a wavelength of 440 to 600 nm. It is as follows.

In addition, among the plurality of metal layers 61, the metal layers 61 that are adjacent to each other with the first transparent layer 20 interposed therebetween are arranged at a first interval S 1, and the metal layers that are adjacent to each other with the second transparent layer 21 in between. 61 are arranged at a second interval S2.

In order to manufacture such a daylighting film 1, as shown in FIG. 11, a first unit film 29 including a first transparent layer 20 and a metal layer 61, and a second unit including a second transparent layer 21 and a metal layer 61. A plurality of unit films 30 are prepared.

As a method for preparing such a first unit film 29, for example, a metal sheet 61 is arranged on the surface (one surface in the thickness direction) of the first transparent layer 20 to prepare a processed sheet, and then the processed sheet. The method of cutting out the 1st unit film 29 of a predetermined shape from the method, the method of arrange | positioning the metal layer 61 on the surface of the 1st transparent layer 20 processed into the predetermined shape, etc. are mentioned. Moreover, as a method for preparing the second unit film 30, the same method as the method for preparing the first unit film 29 can be used except that the first transparent layer 20 is changed to the second transparent layer 21.

As a method of disposing the metal layer 61 on the surface of the first transparent layer 20 (or the second transparent layer 21), for example, the first transparent layer 20 (or the second transparent layer 21) and the metal layer 61 are separately adjusted. And a method of laminating them, a method of forming the metal layer 61 on the surface of the first transparent layer 20 (or the second transparent layer 21), and the like. Preferably, the metal layer 61 is formed on the surface of the transparent layer 9 The method of doing is mentioned.

As a method of forming the metal layer 61 on the surface of the first transparent layer 20 (or the second transparent layer 21), for example, the surface of the first transparent layer 20 (or the second transparent layer 21) by a known film forming method. For example, a method of forming the metal layer 61 may be mentioned. Examples of such a known film forming method include a dry process and a wet process, and a dry process is preferable.

Thus, the daylighting film 1 is prepared as shown in FIG.

According to the fifth embodiment, the plurality of metal layers 61 include metal layers 61 adjacent to each other with an interval of the first interval S1, and metal layers 61 adjacent to each other with an interval of the second interval S2. Is included.

Therefore, even if the altitude of the sun changes, the adjacent metal layer 61 with an interval suitable for the incident angle of the sunlight with respect to the daylighting film 1 reflects the incident light and advances it upward. As a result, also in the fifth embodiment, the same operational effects as those of the first embodiment described above can be achieved.

Each of the first to fifth embodiments and the modified examples can be combined as appropriate.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited thereto. In addition, numerical values, such as a dimension in an Example, can be substituted for the upper limit value or the lower limit value of the corresponding location described in the above embodiment.

Example 1
A 200 μm-thick polyvinyl chloride film (first processed sheet) and a 100 μm-thick polyvinyl chloride film (second processed sheet) are each punched into a circular shape having a diameter of 18 cm, and the first transparent has a thickness of 200 μm. 500 layers (first unit film) and 500 second transparent layers (second unit film) having a thickness of 100 μm were prepared. The relative refractive index of the polyvinyl chloride film with respect to air was 1.54.

Next, the first transparent layer and the second transparent layer having different thicknesses are alternately laminated without using an adhesive therebetween, and then held in a cylindrical shape by applying pressure (5 MPa) from both sides in the lamination direction. Thus, a laminate was prepared. The laminate was 18 cm in diameter × height (dimension in the stacking direction) 15 cm (100 μm × 500 sheets + 200 μm × 500 sheets).

Next, the laminate and the support were set in a cutting device 40 shown in FIG.

Specifically, the laminated body was held by a pair of holding members 42 so as to be sandwiched from both sides in the laminating direction, and the support was wound around the rotating shaft 41 to constitute a support roll.

At this time, the pair of holding members 42 sandwiched the laminated body from both sides in the laminating direction at the pressure (5 MPa). The support also had a polypropylene film (base material) having a thickness of 40 μm and an acrylic pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) having a thickness of 30 μm. The acrylic pressure-sensitive adhesive layer was formed on one side of the polypropylene film, and a release treatment layer with a release treatment agent was provided on the other side of the polypropylene film.

Further, in a state where the laminated body is held by the pair of holding members 42, the tip of the cutting blade 35 is in contact with the side surface of the laminated body. In addition, the cutting blade 35 was arrange | positioned along the lamination direction of a laminated body.

Then, the support drawn 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 42 were driven to rotate counterclockwise by a motor (not shown) of the cutting device 40 as viewed from one axial direction of the holding member 42 (the front side in FIG. 5). .

Then, the laminated body held by the pair of holding members 42 was rotated about the axis, and the support roll was driven about the axis of the rotary shaft 41.

Thereby, the side layer of the laminate on which the support was attached was continuously cut out like a wig.

As described above, the daylighting layer (side layer of the laminated body) on which the support was stuck on one side was cut into a long and flat strip shape. The daylighting layer had a thickness of 200 μm.

In such a daylighting layer, the first transparent layer, the second transparent layer, and the air layer are continuous in the stacking direction (the daylighting layer is a second surface direction orthogonal to both the thickness direction and the first surface direction). It was arranged repeatedly in order. Moreover, the dimension of the lamination direction of the first transparent layer (the second surface direction orthogonal to both the thickness direction and the first surface direction as the daylighting layer) is 200 μm, and the dimension of the second transparent layer in the lamination direction is The dimension in the stacking direction of the air layer was 1 μm.

Then, a double-sided tape with a single-sided separator (peeled body) was prepared separately, and the adhesive layer of the double-sided tape with a single-sided separator was adhered to the other side (cutting surface) of the daylighting layer. Moreover, the double-sided tape with a single-sided separator had a 50 μm-thick PET film (peeling material, separator) and a 50 μm-thick acrylic pressure-sensitive adhesive layer (pressure-sensitive adhesive layer). 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.

Thus, the support and the double-sided tape were affixed to the daylighting layer so as to sandwich the daylighting layer, and a daylighting film was prepared. In addition, the dimension of the thickness direction of the lighting film was 370 micrometers.

Thereafter, the daylighting film was appropriately cut in accordance with the size of the glass window to be attached. Thus, a rectangular daylighting film having a long side of 20 cm and a short side of 15 cm was obtained.

Comparative Example 1
After only 1500 circular second transparent layers (second unit films) having a thickness of 100 μm and a diameter of 18 cm were formed, 1500 second transparent layers were laminated without using an adhesive therebetween. A daylighting film was obtained in the same manner as in Example 1 except that a cylindrical laminate was prepared. The laminate was 18 cm in diameter × height (dimension in the stacking direction) 15 cm (100 μm × 1500 sheets).

In the daylighting layer according to Comparative Example 1, the second transparent layer and the air layer are continuous in the stacking direction (the daylighting layer is a second surface direction orthogonal to both the thickness direction and the first surface direction). It was arranged repeatedly in order. The daylighting layer has a thickness of 200 μm, the dimension of the second transparent layer in the stacking direction (the daylighting layer is a second surface direction perpendicular to both the thickness direction and the first surface direction) is 100 μm, and air The dimension in the stacking direction of the layers was 1 μm.

Comparative Example 2
After only 750 sheets of a circular first transparent layer (first unit film) having a thickness of 200 μm and a diameter of 18 cm were prepared, 750 first transparent layers were laminated without using an adhesive therebetween. A daylighting film was obtained in the same manner as in Example 1 except that a cylindrical laminate was prepared. The laminate was 18 cm in diameter × height (dimension in the stacking direction) 15 cm (200 μm × 750 sheets).

In the daylighting layer according to Comparative Example 2, the first transparent layer and the air layer were sequentially and repeatedly arranged so as to be continuous in the stacking direction (the surface direction perpendicular to the thickness direction as the daylighting layer). In addition, the thickness of the daylighting layer is 200 μm, the dimension in the stacking direction of the first transparent layer (the surface direction perpendicular to the thickness direction as the daylighting layer) is 200 μm, and the dimension in the stacking direction of the air layer is 1 μm. Met.

(Evaluation)
About the lighting film of the obtained Example and each comparative example, the direction change efficiency of light with respect to the incident angle of light was measured as follows.

As shown in FIG. 12, 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 rectangular shape with a long side of 20 cm × short side of 15 cm, and the thickness of the glass window 92 was 3 mm.

Further, an illuminance meter 95 (manufactured by T & D Corporation, illuminance UV recorder, product name: TR-74Ui) and a light 96 (manufactured by Pyphotonics, product name: HL01W) were prepared.

Next, white light was irradiated from the outside of the room 90 with a light 96 so that the incident angle θ of light with respect to the glass window 92 was 40 °. Part of the light emitted from the light 96 passed through the glass window 92 as transmitted light A, proceeded linearly in the room 90, and illuminated the floor portion 93. On the other hand, light other than the transmitted light A out of the light emitted from the light 96 was reflected outside the room 90 by the glass window 92.

And the illuminance meter 95 was arranged in the brightest place on the floor 93. Specifically, the illuminance meter 95 is disposed on the floor portion 93 at a position of 50.6 cm from the wall portion 91. And the illuminance meter 95 measured the illumination intensity on the floor part 93, and made the value the reference illumination intensity.

Next, the light 96 is moved so that the incident angle θ of light with respect to the glass window 92 changes by 10 ° from 40 ° to 80 °, and the illuminance is applied to the brightest part on the floor portion 93 at each incident angle θ. A total of 95 was moved sequentially. Specifically, the illuminance meter 95 is disposed at a position 35.7 cm from the wall portion 91 when the incident angle θ is 50 °, and is located at a position 24.5 cm from the wall portion 91 when the incident angle θ is 60 °. When the incident angle θ is 70 °, it is disposed at a position of 15.5 cm from the wall portion 91, and when the incident angle θ is 80 °, it is disposed at a position of 7.5 cm from the wall portion 91.

Then, the illuminance meter 95 was used to measure the reference illuminance on the floor portion 93 at each incident angle θ. The results are shown in Table 1.

Next, after the release material of the release body of the daylighting film was released, the adhesive layer of the release body was attached to the inner surface of the glass window 92.

Next, the light 96 is irradiated from the outside of the room 90 by the light 96 so that the incident angle θ of the light with respect to the glass window 92 becomes 40 °, and the illuminance meter 95 is placed 50.6 cm from the wall portion 91 on the floor portion 93. Placed in the position. And the illumination intensity on the floor part 93 was measured with the illumination meter 95, and the value was made into measurement illumination intensity.

A part of the transmitted light A passes through the glass window 92 and then is reflected by a plurality of air layers of the daylighting film and travels upward as the direction changing light A1 toward the ceiling portion 94. The other light A2 passed through the daylighting film linearly and illuminated the floor portion 93.

Next, the light 96 is moved so that the incident angle θ of light with respect to the glass window 92 changes by 10 ° from 40 ° to 80 °, and the illuminance meter 95 is placed on the floor portion 93 from the wall portions 91 to 35. They were sequentially moved to positions of 7 cm, 24.5 cm, 15.5 cm, and 7.5 cm. And the measurement illumination intensity on the floor part 93 in each incident angle (theta) was measured.

The light direction changing efficiency at each incident angle θ was calculated by the following formula (1). The results are shown in Table 1.

Formula (1)
Light redirection efficiency [%] = ((reference illuminance [lx] −measured illuminance [lx]) / reference illuminance [lx]) × 100

FIG. 13 shows the change in direction change efficiency with respect to the incident angle θ of light.

As shown in FIG. 13, in the comparative example 1, when the incident angle θ is small (for example, when the incident angle θ = 40 °), the light turning efficiency is high, and as the incident angle θ increases, the light The direction change efficiency is reduced. In Comparative Example 2, when the incident angle θ is large (for example, when the incident angle θ = 80 °), the light direction changing efficiency is high, and as the incident angle θ decreases, the light direction changing efficiency is increased. descend.

On the other hand, in the first embodiment, stable light direction changing efficiency is ensured without depending on the change in the incident angle θ.

Although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be interpreted in a limited manner. Variations of the present invention that are apparent to one of ordinary skill in the art are within the scope of the following claims.

The optical film of the present invention is used for, for example, a daylighting film used for lighting a building.

DESCRIPTION OF SYMBOLS 1 Daylighting film 10 Air layer 60 Low-refractive layer 61 Metal layer Y 1st surface direction Z 2nd surface direction S1 1st space | interval S2 2nd space | interval

Claims

An optical film comprising a plurality of reflective layers configured to reflect light,
Each of the plurality of reflective layers is
Extending in a first direction orthogonal to the thickness direction of the optical film,
In a second direction perpendicular to both the thickness direction and the first direction, the two are arranged in parallel at an interval,
The plurality of reflection layers are adjacent to each other at a first interval and a reflection layer disposed adjacent to each other at a first interval, and a second interval having a different dimension in the second direction from the first interval. An optical film comprising a reflective layer arranged as described above.
2. The optical film according to claim 1, wherein the first interval is 1.25 to 10 times the second interval.