WO2016076039A1

WO2016076039A1 - Optical film manufacturing method and daylighting film

Info

Publication number: WO2016076039A1
Application number: PCT/JP2015/078351
Authority: WO
Inventors: 和也藤岡
Original assignee: 日東電工株式会社
Priority date: 2014-11-12
Filing date: 2015-10-06
Publication date: 2016-05-19
Also published as: JP2016095944A

Abstract

An optical film manufacturing method includes: a preparation step for laminating a plurality of transparent layers and a plurality of light-scattering layers in the thickness direction of the plurality of transparent layers to prepare a substantially columnar shaped laminate extending in the thickness direction, the transparent layers being capable of transmitting light and the light-scattering layers being capable of scattering light; and a cutting step for continuously cutting the side surface layer of the laminate while rotating the laminate about the axial line thereof.

Description

Optical film manufacturing method and daylighting film

The present invention relates to an optical film manufacturing method and a daylighting film manufactured by the manufacturing method.

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. In such an optical member, it has been proposed to reduce light and darkness in the room by scattering light introduced into the room.

For example, a transparent plastic plate having a plurality of slits extending in the horizontal direction, and a processed surface of the slit having irregularities for scattering light (see, for example, Patent Document 1) is configured to transmit light. There has been proposed a daylighting sheet including a light transmitting portion in which a concave portion is formed and a light scattering portion configured to scatter light and filled in the concave portion (see, for example, Patent Document 2).

These optical members are installed in, for example, a window of a house, and the sunlight incident from the outside through the window is reflected, scattered, and collected.

JP 2000-268610 A JP 2014-126708 A

However, the plastic plate described in Patent Document 1 and the daylighting sheet described in Patent Document 2 have a problem of low productivity from the viewpoint of industrial production.

Specifically, in order to manufacture the plastic plate described in Patent Document 1, a plurality of slits are formed in the plastic plate by CO ₂ or excimer laser processing.

However, since the method for producing such a plastic plate is a single wafer method (batch method), there is a limit in improving productivity, and it is not suitable for industrial production.

Moreover, in order to manufacture the daylighting sheet described in Patent Document 2, a light roll is disposed between the mold roll and the base material after disposing the mold roll provided with irregularities so as to face the base material. The mold roll is rotated while supplying the composition constituting the film, and the uneven shape of the mold roll is transferred to the light transmission portion. Thereafter, the concave portion of the light transmission part is filled with the composition constituting the light scattering part.

However, in such a method for manufacturing a daylighting sheet, after preparing a light transmissive portion having a concavo-convex shape, it is necessary to fill the concave portion of the light transmissive portion with a composition constituting the light scattering portion. There are limits to improving productivity.

Therefore, an object of the present invention is to provide an optical film manufacturing method capable of improving productivity while being a simple method, and a daylighting film manufactured by the manufacturing method.

[1] In the present invention, a plurality of transparent layers capable of transmitting light and a plurality of light scattering layers capable of light scattering are laminated in the thickness direction of each of the plurality of transparent layers, Production of an optical film, comprising: a preparation step of preparing a substantially cylindrical laminated body extending; and a cutting step of continuously cutting a side layer of the laminated body by rotating the laminated body about an axis. Is the method.

According to such a method, after laminating a plurality of transparent layers and a plurality of light scattering layers to form a substantially cylindrical laminated body, the laminated body is rotated about the axis, and the side layer of the laminated body By continuously cutting, an optical film in which each of the plurality of transparent layers and the plurality of light scattering layers is continuous in the stacking direction (thickness direction of the transparent layer) can be produced.

That is, after forming a laminate by laminating a plurality of transparent layers and a plurality of light scattering layers, the transparent layer and the light scattering layer are laminated in the laminating direction (transparent layer of the transparent layer) by a simple method of cutting the side layer of the laminate. An optical film continuous in the thickness direction) can be continuously produced. As a result, the productivity of the optical film can be improved.

[2] Further, the present invention includes the method for producing an optical film according to [1], wherein the plurality of light scattering layers are capable of light scattering.

According to such a method, since the light scattering layer is already capable of light scattering, a process for making the light scattering layer capable of light scattering is unnecessary, and the manufacturing process can be simplified.

[3] Further, in the present invention, each of the plurality of light scattering layers is an uneven surface disposed on at least one surface of each of the plurality of transparent layers, and the preparation step includes the uneven surface. The method for producing an optical film according to [2] above, wherein each of the plurality of transparent layers is laminated in the thickness direction to form the laminate.

According to such a method, since the uneven surface disposed on at least one surface of the transparent layer is configured as a light scattering layer, an optical film that can scatter light reliably while having a simple configuration is manufactured. Can do. In addition, since it is not necessary to separately prepare a layer for scattering light, manufacturing cost (material cost) can be reduced.

[4] Further, the present invention further includes a pasting step of pasting a support body on a side surface of the laminate along the thickness direction between the preparatory step and the cutting step. The plurality of transparent layers are laminated so that the uneven surface and the transparent layer facing the uneven surface are in direct contact with each other, and in the cutting step, the side surface of the laminate on which the support is attached The manufacturing method of the optical film as described in said [3] which cut | disconnects a layer continuously is included.

According to such a method, in the laminate, the concavo-convex surface and the transparent layer facing the concavo-convex surface are in direct contact with each other without interposing the adhesive layer. That is, the laminate is formed without using an adhesive. Therefore, the manufacturing cost (material cost) can be reliably reduced as compared with the case where an adhesive is used for forming the laminate.

However, in the laminate, when the uneven surface and the transparent layer facing the uneven surface are in direct contact, in the cutting step, when the side layers of the laminate are continuously cut, the transparent layers adjacent to each other in the thickness direction May peel apart from each other.

In this respect, in the above method, since the side layer of the laminate is cut after the support is attached to the laminate, the transparent layers adjacent to each other in the thickness direction are formed even if no adhesive layer is provided. It can suppress that it peels and separates from each other.

Therefore, it is possible to prevent the plurality of transparent layers from being separated in the cutting process while reducing the manufacturing cost (material cost).

[5] Further, in the present invention, the support is in the form of a sheet, and is configured as a support roll by being wound. In the pasting step, the support drawn out from the support roll is The laminate to which the support is attached by being attached to the side surface of the laminate and rotating the support roll about the axis while rotating the laminate about the axis in the cutting step. The manufacturing method of the optical film as described in said [4] which cut | disconnects the cutting film supported by the said support body continuously by cut | disconnecting the side layer of a body is included.

According to such a method, after the support pulled out from the support roll is attached to the side surface of the laminate, the support roll is rotated about the axis, and the laminate is rotated about the axis. Then, the side layer of the laminate to which the support is attached is continuously cut. Thereby, the optical film which has a support body can be manufactured continuously. Therefore, the productivity of the optical film having the support can be further improved.

[6] Further, the present invention includes the method for producing an optical film according to the above [2], wherein each of the plurality of light scattering layers is a porous layer having a plurality of pores therein.

According to such a method, since the light scattering layer is a porous layer, it is possible to manufacture an optical film that can scatter light reliably with a simple configuration.

[7] Further, in the preparation step, the present invention forms the laminate by alternately laminating each of the plurality of transparent layers and each of the plurality of porous layers. 6]. The manufacturing method of the optical film as described in 6] is included.

According to such a method, in the preparation step, the transparent layer and the porous layer are alternately laminated to form a laminate, so that the transparent layer and the porous layer are stacked in the stacking direction (the thickness direction of the transparent layer). ) Can be produced alternately. Such an optical film can scatter light efficiently.

[8] Further, in the preparation step, the present invention includes, in the preparation step, laminating each of the plurality of transparent layers and each of the plurality of porous layers so as to be in direct contact with each other. The method for producing an optical film according to the above [7], which is pressed from both sides in the direction and heated to 30 ° C. or higher and 180 ° C. or lower is included.

According to such a method, in the laminate, the transparent layer and the porous layer are in direct contact with each other without interposing the adhesive layer. That is, the laminate is formed without using an adhesive. Therefore, the manufacturing cost (material cost) can be reduced as compared with the case where an adhesive is used to form the laminate.

And while pressing a laminated body from the thickness direction both sides and heating to 30 degreeC or more and 180 degrees C or less, the transparent layer and porous layer which mutually adjoin the thickness direction can be thermocompression-bonded, and in a cutting process The transparent layer and the porous layer adjacent to each other can be prevented from being separated from each other and separated.

[9] Further, according to the present invention, each of the plurality of light scattering layers is a foamable layer made of a foamable foamable material and capable of light scattering by foaming, and the foamable layer is foamed. The method for producing an optical film according to the above [1], further comprising a foaming step for forming a light-scatterable foam layer.

According to such a method, since the foam layer capable of scattering light is formed by foaming the foamable layer, an optical film capable of reliably scattering light can be manufactured.

[10] Further, in the present invention, the foaming step is performed after the cutting step, and in the cutting step, the side layer of the laminate is continuously cut to cut out a cutting film, and in the foaming step The method for producing an optical film according to the above [9], wherein the foamable layer contained in the cutting film is foamed.

However, when the foamable layer is foamed before the cutting step, that is, in the laminate, the foam layer may be peeled off from the layer adjacent to the foam layer (foam layer or transparent layer).

In this regard, according to the above method, the foamable layer is foamed after the cutting step, that is, in the cutting film, so that the foam layer is adjacent to the foam layer (foam layer or transparent layer). It can suppress that it peels from.

[11] Further, in the present invention, the preparing step includes a first step of preparing a plurality of unit films including the transparent layer and the foamable layer disposed on the one surface in the thickness direction of the transparent layer, Including the second step of laminating the plurality of unit films in the thickness direction to form the laminate, which includes the method for producing an optical film according to the above [9] or [10]. .

According to such a method, a plurality of unit films each having a transparent layer and a foamable layer are laminated to form a laminated body. Therefore, a plurality of transparent layers and a plurality of foamable layers are laminated to form a laminated body. As compared with the case of forming the film, the preparation process can be facilitated.

[12] Also, in the laminated body according to the present invention, each of the plurality of transparent layers and each of the plurality of foamable layers are disposed so as to be adjacent to each other in the thickness direction, The manufacturing method of the optical film as described in said [11] which has an adhesive layer arrange | positioned between the said mutually adjacent transparent layer and foamable layer is included.

According to such a method, in the laminate, the adjacent transparent layer and the foamable layer are bonded to each other by the pressure-sensitive adhesive layer. Therefore, in the cutting step, the adjacent transparent layer and the foamable layer are separated and separated. Can be suppressed.

[13] Further, the present invention includes the method for producing an optical film according to the above [12], wherein the unit film further includes the pressure-sensitive adhesive layer disposed on one surface in the thickness direction of the foamable layer. It is out.

According to such a method, in the preparation step, a plurality of unit films each including a transparent layer, a foamable layer, and an adhesive layer are laminated to form a laminate, so that the laminate can include an adhesive layer. However, the preparation process can be facilitated.

[14] The present invention is a daylighting film manufactured by the method for manufacturing an optical film according to any one of [1] to [13] above.

According to such a configuration, it is possible to easily and efficiently manufacture while reducing the manufacturing cost.

According to the method for producing an optical film of the present invention, productivity can be improved while being a simple method.

Drawing 1 is an explanatory view for explaining the process of cutting out a transparent layer from the processing sheet concerning a 1st embodiment of the manufacturing method of the optical film of the present invention. FIG. 2 is a perspective view of the transparent layer shown in FIG. FIG. 3 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 layers shown in FIG. is there. FIG. 4 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. 5 is a perspective view of a daylighting film cut out from the laminate shown in FIG. FIG. 6 is an explanatory diagram for explaining a state in which the daylighting film shown in FIG. 5 is attached to the glass window. FIG. 7 is a perspective view of a transparent layer and a light scattering layer according to the second embodiment of the method for producing an optical film of the present invention. FIG. 8 is an explanatory diagram for explaining a process of cutting the side layer of the laminate formed by laminating the transparent layer and the light scattering layer shown in FIG. FIG. 9 is a perspective view of a daylighting film cut out from the laminate shown in FIG. FIG. 10 is an explanatory diagram for explaining a state in which the daylighting film shown in FIG. 9 is attached to the glass window. FIG. 11 is an explanatory diagram for explaining the preparation of a processed sheet according to the third embodiment of the method for producing an optical film of the present invention. 12 is a perspective view of a unit film cut out from the processed sheet shown in FIG. FIG. 13 is an explanatory diagram for explaining a process in which the side layer of the laminate formed by laminating the unit films shown in FIG. 12 is cut. FIG. 14 is an explanatory diagram for explaining a process in which the foamable layer of the cutting film shown in FIG. 13 is foamed to become a foam layer.

1. First Embodiment In the method for producing an optical film of the present invention, as shown in FIGS. 1 to 3, first, a plurality of transparent layers 1 are prepared (prepared).

As shown in FIG. 2, the transparent layer 1 is configured to transmit light, and is preferably formed of a transparent organic material from the viewpoint of ease of processing.

Examples of the transparent organic 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, fluorine resin, urethane resin, cellulose, polyvinyl butyral, ethylene vinyl acetate copolymer (EVA), and the like.

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

The relative refractive index of such an organic material 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.

Such a transparent layer 1 is formed in a substantially circular shape when viewed from the thickness direction, and has an uneven surface 3 as an example of a light scattering layer capable of light scattering.

The concavo-convex surface 3 is arranged on at least one surface of the transparent layer 1, that is, at least one of the both surfaces in the thickness direction of the transparent layer 1 (one surface in the thickness direction and / or the other surface in the thickness direction), Preferably, it is disposed on at least the other surface in the thickness direction of the transparent layer 1, more preferably on both surfaces in the thickness direction of the transparent layer 1. Moreover, although the uneven surface 3 may be a part of the end surface in the thickness direction of the transparent layer 1, it is preferably spread over the whole from the viewpoint of light scattering.

In the first embodiment, the uneven surface 3 is disposed on the other surface in the thickness direction of the transparent layer 1 and is formed over the entire other surface in the thickness direction of the transparent layer 1.

As shown in FIG. 6, the shape of the recess 3 </ b> A on the uneven surface 3 is not particularly limited, and is, for example, a substantially arc shape, a substantially cone shape (for example, a cone or a pyramid), a substantially frustum shape (for example, A truncated cone and a truncated cone). In the first embodiment, the recess 3A of the uneven surface 3 has a substantially semicircular arc shape.

Such a concavo-convex surface 3 is formed by a known embossing process, for example, as will be described in detail later.

The density of the concave portions 3A of the uneven surface 3 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.

As shown in FIG. 2, the thickness of the transparent layer 1 can be appropriately changed depending on the purpose of use, but is, for example, 20 μm or more, preferably 50 μm or more, more preferably 100 μm or more, for example, 10 mm or less. The thickness is preferably 1 mm or less, and more preferably 500 μm or less.

Further, the diameter of the transparent layer 1 is appropriately changed depending on the purpose of use and the like, but 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 layers 1 is formed in substantially the same size.

The light transmittance of the transparent layer 1 (including the uneven surface 3) is, for example, 80% or more, preferably 85% with respect to light having a wavelength of 440 to 600 nm when the thickness of the transparent layer 1 is 100 μm. As mentioned above, More preferably, it is 90% or more, for example, 98% or less.

In order to prepare a plurality of such transparent layers 1, for example, as shown in FIG. 1, a processed sheet 4 made of the organic material described above is prepared, and at least one surface of the processed sheet 4 is uneven by known embossing. After forming the surface 3, the substantially circular transparent layer 1 is cut out from the processed sheet 4.

Specifically, first, a processed sheet 4 having both flat surfaces in the thickness direction is prepared. When the uneven surface 3 is formed on both surfaces in the thickness direction of the transparent layer 1, a pair of emboss rolls having an uneven shape on the peripheral surface is prepared, and the processed sheet 4 is sandwiched between the pair of emboss rolls. And a pair of embossing rolls are rotated. Thereby, the uneven surface 3 is formed on both sides in the thickness direction of the processed sheet 4.

On the other hand, when the uneven surface 3 is formed only on any surface in the thickness direction of the transparent layer 1, an emboss roll having an uneven shape on the peripheral surface, and an elastic roll (for example, a rubber roll) having a smooth peripheral surface Prepare. And the processed sheet 4 whose thickness direction both surfaces are flat surfaces is supplied so that it may be pinched | interposed between an embossing roll and an elastic roll, and an embossing roll and an elastic roll are rotated. Thereby, the uneven surface 3 is formed only on one surface in the thickness direction of the processed sheet 4.

As the processed sheet 4 having the concavo-convex surface 3, a commercially available product (generally called an embossed film, a satin film or the like) can be used. Okamoto)).

Next, the substantially circular transparent layer 1 is cut out from the processed sheet 4 having the uneven surface 3. In this case, the processed sheet 4 may be formed large so that the plurality of transparent layers 1 can be cut out, and a plurality of the transparent layers 1 may be cut out from the processed sheet 4. The transparent layer 1 may be cut out from the processed sheet 4 one by one.

Among the methods for preparing a plurality of such transparent layers 1, preferably from the viewpoint of manufacturing cost, the processed sheet 4 is long and continuous in a predetermined direction so that the plurality of transparent layers 1 can be cut out. A method of forming a flat strip and cutting out a plurality of transparent layers 1 from the processed sheet 4 can be mentioned.

Further, when the processed sheet 4 is formed in a long and flat strip shape, the processed sheet 4 preferably has flexibility and is wound in a roll shape. And the some transparent layer 1 is cut out from the part pulled out from the roll-shaped processed sheet 4. FIG.

Examples of a method for cutting out the transparent layer 1 from the processed sheet 4 include known processing methods such as cutting and punching.

The transparent layer 1 having the uneven surface 3 is processed into a plurality of, for example, 300 or more, preferably 500 or more, more preferably 1000 or more, for example, 60000 or less, preferably 10,000 or less. Cut out from sheet 4.

Next, as shown in FIG. 3, each of the plurality of transparent layers 1 having the concavo-convex surface 3 is laminated in the thickness direction of the transparent layer 1 to prepare (preparation) a substantially cylindrical laminate 2 extending in the thickness direction. (Preparation process). That is, the thickness direction of the transparent layer 1 and the lamination direction of the laminate 2 are the same direction.

More specifically, a plurality of transparent layers 1 are laminated so that their outer peripheral edges coincide with each other when projected in the lamination direction.

At this time, among the plurality of transparent layers 1, an adhesive layer may be provided between the transparent layers 1 adjacent to each other in the stacking direction, or an adhesive layer may not be provided.

Examples of the adhesive that forms such an adhesive layer include known adhesives or pressure-sensitive adhesives such as epoxy, silicone, acrylic, and ultraviolet curable types. The adhesive preferably transmits light.

The thickness of the adhesive layer is, for example, 20 nm or more, preferably 50 nm or more, for example, 100 μm or less, preferably 10 μm or less.

Such an adhesive layer is preferably not provided between the transparent layers 1 adjacent to each other in the stacking direction from the viewpoint of material cost. In this case, in the transparent layers 1 adjacent to each other in the laminate 2, the uneven surface 3 of the transparent layer 1 on one side in the stacking direction is in direct contact with the transparent layer 1 on the other side in the stacking direction. That is, the uneven surface 3 and the transparent layer 1 facing the uneven surface 3 are in direct contact with each other.

Thus, the columnar laminate 2 extending in the lamination direction is prepared. In addition, the laminated body 2 is hold | maintained in a column shape by pressing from the both sides of a lamination direction as needed.

In such a laminate 2, a plurality of transparent layers 1 (parts excluding the uneven surface 3) and a plurality of uneven surfaces 3 are stacked so as to alternate in the stacking direction.

In FIG. 3, the number of the transparent layers 1 is omitted for convenience, and the stacked body 2 is described as being composed of 6 transparent layers 1, but actually, the stacked body 2 is For example, 300 to 60000 sheets, preferably 500 to 30000 sheets, and more preferably 1000 to 10,000 transparent layers 1 are laminated.

The height (stacking direction length) of the laminate 2 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, if necessary, a support 6 is attached to the side surface 5 (surface extending along the lamination direction) of the laminate 2 so as to be along the lamination direction (thickness direction of the transparent layer 1) (sticking step).

As shown in FIG. 5, the support 6 has a sheet shape and includes a base material 7 and an adhesive layer 8 provided on one surface of the base material 7. In FIGS. 3 and 4, the support 6 is illustrated as a single layer for convenience.

Examples of the substrate 7 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). It is preferable that such a base material 7 is comprised so that light may permeate | transmit from a viewpoint of the freedom degree of the usage condition of the lighting film 20 (after-mentioned).

Among such base materials 7, a low adhesive base material made of a nonpolar polymer is preferable, and a low adhesive base material made of polypropylene is more preferable.

Further, a release treatment layer with a release treatment agent is appropriately provided on the surface of the base material 7 depending on the production method and the usage mode. The peeling force of the base material 7 by a peeling process layer is adjusted suitably.

The thickness of the base material 7 can be appropriately changed according to the purpose of use, but 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 7 is, for example, 85% or more, preferably 90% or more, and more preferably 92% with respect to light having a wavelength of 440 to 600 nm when the thickness of the substrate 7 is 50 μm. % Or more, for example, 98% or less.

Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 8 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 adhesion layer 8 can also be comprised from a well-known double-sided adhesive tape.

Such an adhesive layer 8 is formed in a thin layer on the entire surface of one surface of the substrate 7, and the thickness thereof is, for example, 1 μm or more, preferably in a state where the support 6 is attached to the laminate 2. Is 5 μm or more, for example, 100 μm or less, preferably 40 μm or less.

If the substrate 7 itself is sticky, the support layer 6 does not require the adhesive layer 8.

As shown in FIG. 3, in order to affix such a support body 6 to the side surface 5 of the laminated body 2 along the laminating direction, the laminated body 2 is pressed from both sides in the laminating direction as necessary. The laminated body 2 is held.

As the pressurizing condition, the pressure from one side (the other side) in the stacking direction with respect to the stacked body 2 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.

Then, the support 6 is continuously attached to the laminate 2 using, for example, a touch roll so that the adhesive layer 8 of the support 6 adheres to the side surface 5 of the laminate 2.

By the above, the support body 6 is affixed on the side surface 5 of the laminated body 2 along the lamination direction.

Next, the substantially cylindrical laminated body 2 is rotated about the axis to continuously cut the side layer 9 of the laminated body 2 (cutting step).

More specifically, the cutting blade 11 is disposed along the stacking direction, and the stacked body 2 is rotated around its axis, and the side layer 9 is cut out from the stacked body 2 like a wig.

As described above, the daylighting film 20 as an example of the optical film is cut out from the laminate 2.

In addition, when the manufacturing method of the optical film of this invention includes the sticking process, the side layer 9 of the laminated body 2 to which the support body 6 was affixed is cut | disconnected continuously in a cutting process.

Therefore, the daylighting film 20 includes a film main body 21 and a support 6 as shown in FIG.

The film body 21 is a side layer 9 cut out from the laminate 2, and is formed in a thin film shape. The film main body 21 includes a plurality of transparent layers 1 having an uneven surface 3. In the film main body 21, the plurality of transparent layers 1 are arranged so as to be continuous in the laminating direction (the surface direction orthogonal to the thickness direction as the film main body 21), and the plurality of uneven surfaces 3 are arranged in the laminating direction (film main body). 21 in the direction of the surface 21) and are arranged in parallel at equal intervals (for the thickness of the transparent layer 1). Each of the plurality of uneven surfaces 3 extends so as to be orthogonal to the stacking direction (the surface direction of the film body 21).

Further, in the film body 21, air is slightly present at the boundary 22 between the transparent layers 1 adjacent to each other in the stacking direction to form an air layer 23. Specifically, the air layer 23 is a region between the uneven surface 3 of the transparent layer 1 on one side in the stacking direction and the one surface of the transparent layer 1 on the other side in the stacking direction. The interface between the layer 1 and the air layer 23 has a shape corresponding to the uneven surface 3.

The thickness of the film body 21 can be appropriately set depending on the purpose of use, but is, for example, 20 μm or more, preferably 50 μm or more, more preferably 100 μm or more, for example, 10 ⁴ μm or less, preferably 2 × 10 ³ μm. Hereinafter, it is more preferably 500 μm or less, particularly preferably 300 μm or less. In addition, the thickness of the film main body 21 can be appropriately adjusted by the arrangement and angle of the cutting blade 11 with respect to the laminate 2 when the laminate 2 is cut.

Moreover, when the manufacturing method of the optical film of this invention includes the sticking process, it is preferable to implement said sticking process and a cutting process continuously with the cutting device 13, as shown in FIG.

The cutting device 13 includes a rotating shaft 14, a pair of holding members 15, and a cutting blade 11.

The rotary shaft 14 has a substantially cylindrical shape and is configured to be rotatable around the axis. A long and flat belt-like support 6 is wound around the rotating shaft 14. Specifically, the long and flat belt-like support 6 is wound around the rotary shaft 14 in a spiral manner so that the adhesive layer 8 is positioned on the inner side in the radial direction of the rotary shaft 14 with respect to the base material 7. Thus, the support 6 is configured as a support roll 16 centered on the rotation shaft 14.

In the support roll 16, the support 6 is disposed adjacent to the radial direction of the rotating shaft 14, and the adhesive layer 8 and the base material 7 are sequentially and repeatedly disposed.

In addition, when the support body 6 is comprised as the support body roll 16, the peeling process layer is provided in the surface on the opposite side to the adhesion layer 8 in the base material 7. FIG. Therefore, in the radial direction of the rotating shaft 14, between the adjacent support bodies 6, specifically, the adhesive layer 8 of the support body 6 disposed on the radially outer side and the base of the support body 6 disposed on the radially inner side. A release treatment layer is interposed between the material 7.

The pair of holding members 15 are arranged with respect to the support roll 16 with an interval in the radial direction of the support roll 16. Each of the pair of holding members 15 has a substantially disk shape, and is configured to be rotatable about its axis.

Further, the pair of holding members 15 are arranged at intervals in the axial direction of the holding member 15. And a pair of holding member 15 is holding the laminated body 2 by pinching | interposing the substantially cylindrical laminated body 2 with said pressure from the both sides of the lamination direction. In addition, each holding member 15 is arrange | positioned so that the laminated body 2 and an axis line may correspond in the state which hold | maintained the laminated body 2. FIG.

The cutting blade 11 is disposed along the stacking direction with respect to the side surface 5 of the stacked body 2 held by the pair of holding members 15, and the tip of the cutting blade 11 is placed on the side surface 5 of the stacked body 2. In contact.

In addition, the cutting blade 11 maintains the state in which the tip of the cutting blade 11 is in contact with the side surface 5 of the laminated body 2 as the diameter of the laminated body 2 decreases as the cutting process progresses. It is configured to approach.

In order to continuously perform the pasting process and the cutting process with such a cutting device 13, first, the support body 6 pulled out from the support body roll 16 is held by the pair of holding members 15. Affixing to the side surface 5 (applying step).

More specifically, the support 6 is drawn toward the tangential direction of the laminate 2 such that the adhesive layer 8 of the drawn support 6 adheres to the side surface 5 of the laminate 2, and the central angle in the laminate 2 is For example, it is attached to the side surface 5 of the laminate 2 in the range of 90 ° to 270 °, preferably in the range of 120 ° to 240 °.

Next, the pair of holding members 15 are rotationally driven in the counterclockwise direction when viewed from the front side in FIG. 4 by a driving force from a driving source such as a motor provided in the cutting device 13.

Then, the laminate 2 held by the pair of holding members 15 rotates about the axis, and the support roll 16 is driven about the axis of the rotating shaft 14.

Thereby, the side layer 9 of the laminate 2 to which the support 6 is attached is continuously cut out by the cutting blade 11 like wig peeling (cutting step).

Thus, a long and flat strip-shaped daylighting film 20 is prepared continuously from the laminate 2 and the support roll 16.

Further, as shown in FIG. 5, if necessary, an adhesive layer 24 is provided on the surface of the daylighting film 20 on the side opposite to the support 6 of the film main body 21. In this case, the daylighting film 20 includes an adhesive layer 24 in addition to the film body 21 and the support 6.

The adhesive layer 24 is formed by applying an adhesive or a pressure-sensitive adhesive to the surface of the film body 21 opposite to the support 6.

Examples of the adhesive or pressure-sensitive adhesive include known adhesives or pressure-sensitive adhesives such as epoxy-based, silicone-based, acrylic, and ultraviolet curable types. The adhesive or pressure-sensitive adhesive preferably transmits light.

In such a daylighting film 20 manufacturing method, as shown in FIG. 3, a plurality of transparent layers 1 having uneven surfaces 3 are laminated to form a substantially cylindrical laminate 2. The side layer 9 of the laminated body 2 is continuously cut by rotating around the center. Thereby, the lighting film 20 in which the some transparent layer 1 which has the uneven surface 3 continues in the lamination direction (thickness direction of the transparent layer 1) is manufactured.

That is, after forming the laminated body 2 by laminating the transparent layer 1 having the uneven surface 3, the transparent layer 1 having the uneven surface 3 is laminated in the lamination direction ( The daylighting film 20 continuous in the thickness direction of the transparent layer 1 can be continuously produced. As a result, the productivity of the daylighting film 20 can be improved.

Therefore, the manufacturing method of such a lighting film 20 can manufacture the lighting film 20 simply and efficiently, and can be used suitably as an industrial manufacturing method of the lighting film 20.

Further, the uneven surface 3 can scatter light as shown in FIG. Therefore, the manufacturing process can be simplified.

The uneven surface 3 is disposed on at least one surface of the transparent layer 1 (that is, one surface in the stacking direction and / or the other surface in the stacking direction). Therefore, it is possible to manufacture the daylighting film 20 that can scatter light reliably with a simple configuration. In addition, since it is not necessary to separately prepare a layer for scattering light, manufacturing cost (material cost) can be reduced.

As shown in FIG. 3, in the laminate 2, the uneven surface 3 and the transparent layer 1 facing the uneven surface 3 are in direct contact with each other without an adhesive layer interposed therebetween. That is, the laminate 2 is formed without using an adhesive. Therefore, it is possible to reduce the manufacturing cost (material cost) compared to the case where an adhesive is used for forming the laminate 2.

Moreover, since the side surface layer 9 of the laminated body 2 is cut after the support 6 is bonded to the laminated body 2, the transparent layers 1 adjacent to each other in the thickness direction can be connected to each other even if no adhesive layer is provided. It can suppress peeling and falling apart.

Therefore, it is possible to prevent the plurality of transparent layers 1 from being separated in the cutting process while reducing the manufacturing cost (material cost).

Moreover, in 1st Embodiment, as shown in FIG. 4, after the support body 6 pulled out from the support body roll 16 is affixed on the side surface 5 of the laminated body 2, the support body roll 16 is made centering on an axis line. While rotating, the laminated body 2 is rotated centering | focusing on an axis line, and the side surface layer 9 of the laminated body 2 to which the support body 6 was affixed is cut | disconnected continuously. Thereby, the daylighting film 20 having the support 6 can be continuously manufactured. As a result, the productivity of the daylighting film 20 having the support 6 can be further improved.

The lighting film 20 manufactured in this way is attached to, for example, the inner surface of the glass window 26 in a building such as a house 25 as shown in FIG. Moreover, you may attach so that it may be contained as an inner layer of a multilayer glass or a laminated glass.

In order to attach the daylighting film 20 to the glass window 26 or the like, first, the daylighting film 20 is cut into a shape and size corresponding to the attachment location. Examples of the method for cutting the daylighting film 20 include known processing methods such as cutting and punching.

Next, the daylighting film 20 is attached to the inner side surface of the glass window 26 so that, for example, the stacking direction (the surface direction of the film body 21) is along the vertical direction. When the daylighting film 20 includes the adhesive layer 24, the adhesive layer 24 is adhered to the inner surface of the glass window 26. Thereby, the daylighting film 20 is attached to the inner surface of the glass window 26. In this case, the substrate 7 of the support 6 is held on the film body 21 without being peeled off. Therefore, it is not necessary to provide a release treatment layer on the surface of the base material 7 on the adhesive layer 8 side.

When the daylighting film 20 is thus attached to the glass window 26, a part of the light L <b> 1 out of the light L (for example, sunlight) incident from the outside through the glass window 26 passes through the transparent layer 1. And proceed toward the floor 27 of the house 25.

On the other hand, among the light L incident from the outside, the other portion of the light L2 enters the transparent layer 1 and then enters the boundary 22 (more specifically, the air layer 23) of the transparent layers 1 adjacent to each other in the vertical direction. It is reflected and scattered and introduced into the house 25.

Therefore, according to the daylighting film 20, the daylight can be efficiently taken and the brightness of the entire house 25 can be improved efficiently.

Moreover, in 1st Embodiment, although the uneven surface 3 is formed over the whole thickness direction end surface of the transparent layer 1, as shown in FIG. 2, it is not limited to this, The thickness direction end surface of the transparent layer 1 is You may form in only one part. In this case, the area of the concavo-convex surface 3 is, for example, 10% or more, preferably 50% or more, for example, 100% or less, preferably 80% or less, with respect to the end surface in the thickness direction of the transparent layer 1.

Moreover, in 1st Embodiment, as shown in FIG. 3, after the support body 6 is affixed on the side surface 5 of the laminated body 2 (attachment process), the side surface layer 9 of the laminated body 2 is cut out ( Cutting step), without being limited thereto, the side layer 9 of the laminate 2 may be cut out without attaching the support 6 to the side 5 of the laminate 2. That is, the manufacturing method of the optical film of this invention does not need to include a sticking process.

In this case, in the preparation step, an adhesive layer is provided between the transparent layers 1 adjacent to each other in the stacking direction among the plurality of transparent layers 1. Thereby, the laminated body 2 in which a plurality of transparent layers 1 and a plurality of adhesive layers are alternately arranged in the lamination direction is prepared (preparation step). And the daylighting film 20 which consists only of the film main body 21 is prepared by cutting out the side surface layer 9 of the laminated body 2 as mentioned above (cutting process).

Moreover, in 1st Embodiment, as shown in FIG. 5, although the adhesive layer 24 is provided in the surface on the opposite side to the support body 6 of the film main body 21, it is not limited to this, The adhesive layer 24 is as follows. It does not have to be provided in the daylighting film 20.

In this case, when the daylighting film 20 is attached to the inner surface of the glass window 26, the base material 7 of the support 6 is peeled off, and the exposed adhesive layer 8 is adhered to the inner surface of the glass window 26. That is, since the base material 7 is removed from the lighting film 20, it may transmit light or may not transmit light. Further, a release treatment layer is provided on the surface of the base material 7 on the adhesive layer 8 side.

Also in such a modification, the same operational effects as those of the first embodiment described above can be achieved.
2. Second Embodiment Next, a second embodiment of the method for producing an optical film of the present invention will be described with reference to FIGS. 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. 3, the laminate 2 is formed by laminating a plurality of transparent layers 1 having an uneven surface 3, but in the second embodiment, the laminate 35 is a figure. 7 and FIG. 8, a plurality of transparent layers 1 and a plurality of light scattering layers 31 are formed by being laminated.

Therefore, in the second embodiment, first, a plurality of transparent layers 1 and light scattering layers 31 are prepared.

In the second embodiment, each of the plurality of transparent layers 1 does not have the uneven surface 3. That is, each of both end surfaces in the thickness direction of the transparent layer 1 is a flat surface. The transparent layer 1 is preferably formed from an ethylene vinyl acetate copolymer (EVA).

The light transmittance of such a transparent layer 1 is, for example, 80% or more, preferably 90% or more, more preferably, with respect to light having a wavelength of 440 to 600 nm when the thickness of the transparent layer 1 is 100 μm. 92% or more, for example, 98% or less.

In order to prepare a plurality of such transparent layers 1, for example, as shown in FIG. 1, a first processed sheet 33 made of the above-described organic material and having flat surfaces in the thickness direction is prepared. The substantially circular transparent layer 1 is cut out from the sheet 33.

As the first processed sheet 33, a commercially available product can be used, and examples thereof include EVASAFE (manufactured by Bridgestone), Ultra Pale (manufactured by Sanvik), and the like.

Moreover, as a method of cutting out the transparent layer 1 from the 1st processed sheet 33, the method similar to the method of cutting out the transparent layer 1 from the processed sheet 4 is mentioned, for example, Preferably, it is a long and flat strip-shaped 1st processed sheet. There is a method in which a plurality of transparent layers 1 are cut out from a portion wound around the roll 33 and drawn out from the roll-shaped first processed sheet 33.

Then, a plurality of transparent layers 1, for example, 100 sheets or more, preferably 300 sheets or more, more preferably 400 sheets or more, for example, 30000 sheets or less, preferably 5000 sheets or less, more preferably 600 sheets. Thereafter, the first processed sheet 33 is cut out.

Each of the plurality of light scattering layers 31 is a layer capable of light scattering as shown in FIG. Examples of the light scattering layer 31 include a particle-containing layer and a porous layer.

The particle-containing layer is formed of, for example, a matrix resin in which fine particles are dispersed, and the light scattering property is controlled by the refractive index difference between the fine particles and the matrix resin and the state of the fine particles.

Examples of the matrix resin include the transparent organic materials described above, and preferably include an acrylic resin, a urethane resin, a polyolefin, and a polyester. Such matrix resins may be used alone or in combination of two or more.

Examples of the fine particles include silica, barium sulfate, polystyrene, polyolefin, and the like, and preferably silica. Such fine particles may be used alone or in combination of two or more.

The porous layer is formed from, for example, a matrix resin having a large number of pores inside.

Examples of the matrix resin include the transparent organic materials described above, preferably polyester, acrylic resin, polyethylene, polypropylene, and more preferably polyethylene terephthalate (PET). Such matrix resins may be used alone or in combination of two or more.

Examples of a method for preparing such a matrix resin in a porous layer include known porosification methods such as a foaming method, a stretching method, a phase separation method, and a fusion method, and preferably a phase separation method. It is done.

The porosity of the porous layer (ratio of voids in the porous layer) is, for example, 10% by volume or more, preferably 30% by volume or more, for example, 80% by volume or less, preferably 70% by volume or less. The porosity can be calculated from (bulk volume of porous layer−matrix resin volume) / bulk volume of porous layer × 100.

Among such light scattering layers 31, a porous layer is preferable. In the second embodiment, the light scattering layer 31 is a porous layer.

The thickness of the light scattering layer 31 is, for example, 10 μm or more, preferably 20 μm or more, for example, 200 μm or less, preferably 100 μm or less.

The ratio of the thickness of the light scattering layer 31 to the thickness of the transparent layer 1 (thickness of the light scattering layer 31 / thickness of the transparent layer 1) is, for example, 2/1 or more, preferably 1/1 or more, for example, 1/5 or less, preferably 1/10 or less.

In order to prepare a plurality of such light scattering layers 31, for example, as shown in FIG. 1, a second processed sheet 34 made of the matrix resin described above and having both flat surfaces in the thickness direction is prepared. A substantially circular light scattering layer 31 is cut out from the processed sheet 34.

When the light scattering layer 31 is a particle-containing layer, the above-described fine particles are dispersed in the second processed sheet 34. As the second processed sheet 34, commercially available products (generally, diffusion sheets) For example, an opt saver (manufactured by Kimoto) may be used.

Moreover, when the light-scattering layer 31 is a porous layer, many pores are formed in the second processed sheet 34. As such a second processed sheet 34, a commercially available product can be used, For example, Lumirror EA3S (manufactured by Toray Industries, Inc.), Sunmap (manufactured by Nitto Denko Corporation) and the like can be mentioned.

Moreover, as a method of cutting out the light-scattering layer 31 from the 2nd processed sheet 34, the method similar to the method of cutting out the light-scattering layer 31 from the processed sheet 4 is mentioned, for example, Preferably, it is long and flat strip-like 2nd. There is a method in which the processed sheet 34 is wound into a roll shape, and a plurality of light scattering layers 31 are cut out from a portion drawn from the rolled second processed sheet 34.

The light scattering layer 31 has a plurality of, for example, 100 or more, preferably 300 or more, more preferably 400 or more, for example, 30000 or less, preferably 5000 or less, and more preferably 600. From the second processed sheet 34, the number of sheets is cut out.

Next, as shown in FIG. 8, each of the plurality of transparent layers 1 and each of the plurality of light scattering layers 31 (porous layers) are alternately stacked to prepare a stacked body 35 (preparation step). .

More specifically, each of the plurality of transparent layers 1 and each of the plurality of light scattering layers 31 are alternately stacked so that their outer peripheral edges coincide with each other when projected in the stacking direction.

At this time, in the stacked body 35, the adhesive layer described above may be provided between the transparent layer 1 and the light scattering layer 31 adjacent to each other in the stacking direction, or the adhesive layer may not be provided. From the viewpoint of cost, it is preferable not to provide an adhesive layer. When the adhesive layer is not provided on the stacked body 35, the transparent layer 1 and the light scattering layer 31 that are adjacent to each other in the stacked body 35 are in direct contact with each other.

As described above, the cylindrical laminate 35 extending in the stacking direction is prepared.

In FIG. 8, for the sake of convenience, the numbers of the transparent layers 1 and the light scattering layers 31 are omitted, and the laminate 35 is composed of six transparent layers 1 and six light scattering layers 31 each. In practice, however, in the laminate 35, each of the transparent layer 1 and the light scattering layer 31 is, for example, 100 to 30000, preferably 300 to 5000, and more preferably 400. It is formed by stacking up to 600 sheets.

The height of the stacked body 35 (the length in the stacking direction) is the same as the height of the stacked body 2, for example.

Next, the laminated body 35 is subjected to thermocompression bonding (heating press) as necessary.

More specifically, the laminated body 35 is pressed and heated from both sides in the laminating direction.

As conditions for thermocompression bonding, the pressure from one side (the other side) in the stacking direction with respect to the stacked body 35 is, for example, 0.1 MPa or more, preferably 0.5 MPa or more, for example, 50 MPa or less, preferably 5 MPa or less. The temperature is, for example, 30 ° C. or higher, preferably 50 ° C. or higher, for example, 180 ° C. or lower, preferably 150 ° C. or lower. The thermocompression bonding time is, for example, 1 minute or more, preferably 5 minutes or more, for example, 180 minutes or less, preferably 60 minutes or less.

Thereby, in the laminate 35, the light scattering layer 31 is fused to the adjacent transparent layer 1.

Next, the substantially cylindrical laminate 35 is rotated about the axis to continuously cut the side layer 36 of the laminate 35 (cutting step).

More specifically, the cutting blade 11 is arranged along the stacking direction, and the stacked body 35 is rotated about its axis, and the side layer 36 is cut out from the stacked body 35 like a wig.

Thus, the daylighting film 40 as an example of the optical film is cut out from the laminate 35.

As shown in FIG. 9, the daylighting film 40 is a side layer 36 cut out from the laminated body 35 and is formed in a thin film shape. The daylighting film 40 includes a plurality of transparent layers 1 and a plurality of light scattering layers 31, and the transparent layer 1, the light scattering layer 31, and the stacking direction (the surface direction orthogonal to the thickness direction as the daylighting film 40) However, they are sequentially and repeatedly arranged so as to be continuous.

The plurality of light scattering layers 31 are arranged in parallel at equal intervals (the thickness of the transparent layer 1) in the stacking direction, and the light scattering layers 31 are orthogonal to the stacking direction. It extends.

The thickness of the daylighting film 40 is, for example, the same as the thickness of the film body 21 described above. Moreover, said adhesive layer 24 can also be provided in the one surface of the lighting film 40 as needed.

In such a second embodiment, as shown in FIG. 10, since the light scattering layer 31 is a porous layer, it is possible to manufacture a daylighting film 40 that can scatter light reliably with a simple configuration. .

Further, in the preparation step, as shown in FIG. 8, the transparent layer 1 and the light scattering layer 31 (porous layer) are alternately stacked to form the stacked body 35, so that the transparent layer 1 and the light scattering layer 31 are formed. It is possible to manufacture a daylighting film 40 in which (porous layer) is alternately arranged in the stacking direction (thickness direction of the transparent layer 1). Such a daylighting film 40 can scatter light efficiently.

Further, as shown in FIG. 8, in the laminate 35, the transparent layer 1 and the light scattering layer 31 (porous layer) are in direct contact with each other without an adhesive layer. That is, the laminated body 35 is formed without using an adhesive. Therefore, the manufacturing cost (material cost) can be reduced as compared with the case where an adhesive is used to form the stacked body 35.

The laminate 35 is pressed from both sides in the thickness direction and heated to 30 ° C. or more and 180 ° C. or less, so that the transparent layer 1 and the light scattering layer 31 (porous layer) adjacent to each other in the thickness direction are bonded by thermocompression bonding. In the cutting step, it can be suppressed that the transparent layer 1 and the light scattering layer 31 (porous layer) adjacent to each other are separated from each other and separated.

Also in the second embodiment, the same operational effects as those of the first embodiment described above can be achieved.

As shown in FIG. 10, the daylighting film 40 manufactured in this way is attached to, for example, the inner surface of the glass window 26 in a building such as a house 25 in the same manner as the daylighting film 20 of the first embodiment. .

Then, when the daylighting film 40 is attached to the glass window 26, a part of the light L 1 out of the light L (for example, sunlight) incident from the outside through the glass window 26 passes through the transparent layer 1. , Proceed toward the floor 27 of the house 25.

On the other hand, of the light L incident from the outside, the other part of the light L2 is scattered by being incident on the light scattering layer 31 and then being reflected by the pores 41 (or fine particles 41) in the light scattering layer 31. And introduced into the house 25.

Therefore, according to the daylighting film 40, the daylight can be efficiently taken and the brightness of the entire house 25 can be improved efficiently.

Moreover, in 2nd Embodiment, as shown in FIG. 7, although the transparent body 1 and each of the light-scattering layer 31 prepared several separately and laminated | stacked them, the laminated body 35 was prepared, However, the laminate 35 can also be prepared by preparing a plurality of unit films in which the transparent layer 1 and the light scattering layer 31 are laminated together and laminating them.

In the second embodiment, as shown in FIG. 8, the laminated body 35 is subjected to thermocompression bonding (heating press) as necessary in the preparation step. However, the present invention is not limited to this, and the laminated body 35 is thermocompression bonded. It does not have to be done.

In this case, in the laminated body 35, an adhesive layer is provided between the transparent layer 1 and the light scattering layer 31 that are adjacent to each other in the laminating direction. As a result, the transparent layer 1 and the light scattering layer 31 that are adjacent to each other in the stacking direction are bonded together by the adhesive layer. Then, by cutting out the side layer 36 of the laminate 35 as described above (cutting step), the transparent layer 1, the light scattering layer 31, and the adhesive layer are sequentially and repeatedly arranged so as to be continuous in the stacking direction. A daylighting film 40 is prepared.

Even in such a modification, the same operational effects as those of the above-described second embodiment can be obtained.
3. Third Embodiment Next, a third embodiment of the method for producing an optical film of the present invention will be described with reference to FIGS. Note that in the third embodiment, members similar to those in the first embodiment and second embodiment described above are given the same reference numerals, and descriptions thereof are omitted.

In the first embodiment, as shown in FIG. 3, the laminate 2 is formed by laminating a plurality of transparent layers 1 having uneven surfaces 3, but in the third embodiment, the laminate 46 is a figure. 12 and FIG. 13, the unit film 47 including the transparent layer 1 and the foamable layer 45 is formed by laminating a plurality.

Therefore, in the third embodiment, first, a plurality of unit films 47 including the transparent layer 1 and the foamable layer 45 are prepared (prepared) (first step).

In the third embodiment, the transparent layer 1 does not have the uneven surface 3. That is, each of the thickness direction both surfaces of the transparent layer 1 is a flat surface. The transparent layer 1 is preferably made of polyester, more preferably polyethylene terephthalate (PET).

The foamable layer 45 is disposed on one surface in the thickness direction of the transparent layer 1. The foamable layer 45 is made of a foamable material that can be foamed, and can be scattered by foaming.

The foamable material contains, for example, an adhesive and a foaming agent.

Examples of adhesives include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, fluorine adhesives, and styrene. -Diene block copolymer-based pressure-sensitive adhesives, radiation-curable pressure-sensitive adhesives (or energy beam-curable pressure-sensitive adhesives), and the like. Such pressure-sensitive adhesives may be used alone or in combination of two or more.

Among these pressure-sensitive adhesives, preferably, an acrylic pressure-sensitive adhesive and a rubber-based pressure-sensitive adhesive, more preferably an acrylic pressure-sensitive adhesive.

The relative refractive index of the pressure-sensitive adhesive contained in such a foamable material is, for example, 1.30 or more, preferably 1.40 or more, for example, 1.65 or less, preferably with respect to the refractive index of air. 1.60 or less. The refractive index can be measured with a prism coupler.

Examples of the foaming agent include thermally expandable microspheres, inorganic foaming agents (for example, ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, etc.), organic foaming agents (for example, azodicarbonamide, 4,4′-oxybis). (Benzenesulfonyl hydrazide), p-toluylenesulfonyl semicarbazide and the like), preferably, thermally expandable microspheres.

The thermally expandable microsphere is a microencapsulated foaming agent, and includes, for example, a shell constituting an elastic outer shell and an inclusion inside the shell.

Examples of the material forming the shell include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone.

The inclusion is a substance that expands by gasification upon heating, and examples thereof include isobutane, propane, and pentane.

Such heat-expandable microspheres can be produced by a known method such as a coacervation method or an interfacial polymerization method.

In addition, as the thermally expandable microsphere, a commercially available product can be used, and examples include Matsumoto Microsphere (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.).

The content of the foaming agent is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, for example, 50 parts by mass or less, preferably 30 parts by mass or less with respect to 100 parts by weight of the adhesive of the foamable material. is there.

If necessary, the foamable material may be a polymer component such as an adhesive component (base polymer), a plasticizer, a crosslinking agent, a tackifier, a pigment, a dye, a filler, an anti-aging agent, a conductive material, an antistatic agent, etc. These additives can also be included as appropriate.

The thickness of the foamable layer 45 is, for example, 5 μm or more, preferably 10 μm or more, for example, 100 μm or less, preferably 50 μm or less.

The ratio of the thickness of the foamable layer 45 to the thickness of the transparent layer 1 (thickness of the foamable layer 45 / thickness of the transparent layer 1) is, for example, 2/1 or more, preferably 1/1 or more, for example, 1/5 or less, preferably 1/10 or less.

Further, the unit film 47 includes an adhesive layer 48 as necessary, as shown in FIG. Note that the unit film 47 according to the third embodiment includes an adhesive layer 48.

The pressure-sensitive adhesive layer 48 is disposed on one surface of the unit film 47 in the thickness direction of the foamable layer 45.

Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 48 include the same pressure-sensitive adhesive as the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 8, and preferably a light-transmitting pressure-sensitive adhesive. Moreover, the adhesive layer 48 can also be comprised from a well-known double-sided adhesive tape.

Among such pressure-sensitive adhesive layers 48, double-sided pressure-sensitive adhesive tapes are preferable, and base-material-less double-sided pressure-sensitive adhesive tapes are more preferable.

The thickness of the pressure-sensitive adhesive layer 48 is, for example, 10 μm or more, preferably 20 μm or more, for example, 100 μm or less, preferably 50 μm or less.

The ratio of the thickness of the pressure-sensitive adhesive layer 48 to the thickness of the transparent layer 1 (thickness of the pressure-sensitive adhesive layer 48 / thickness of the transparent layer 1) is, for example, 2/1 or more, preferably 1/1 or more, 1/5 or less, preferably 1/10 or less.

The light transmittance of the pressure-sensitive adhesive layer 48 is, for example, 80% or more, preferably 90% or more, more preferably, with respect to light having a wavelength of 440 to 600 nm when the thickness of the pressure-sensitive adhesive layer 48 is 100 μm. 95% or more, for example, 98% or less.

The relative refractive index of the pressure-sensitive adhesive layer 48 is, for example, 1.30 or more, preferably 1.40 or more, for example, 1.65 or less, preferably 1.60 or less with respect to the refractive index of air. is there. The refractive index can be measured with a prism coupler.

In order to prepare a plurality of such unit films 47, as shown in FIG. 1, for example, first, a processed sheet 49 including the transparent layer 1 and the foamable layer 45 and, if necessary, further including an adhesive layer 48 is prepared. Then, the substantially circular transparent layer 1 is cut out from the processed sheet 49. In this case, the processed sheet 49 may be formed large so that a plurality of unit films 47 can be cut out, and a plurality of unit films 47 may be cut out from the processed sheet 49. The processed sheets 49 may be cut out from the processed sheets 49 one by one.

As a method for preparing such a processed sheet 49, for example, a foamable layer 45 is formed on the surface of the transparent layer 1 by a known film forming method (for example, a wet process, a dry process, etc.), and foaming is possible if necessary. A method for forming the pressure-sensitive adhesive layer 48 on the surface of the layer 45, a foamable sheet 45 including a foamable layer 45 and a pair of transparent layers 1 sandwiching the foamable layer 45 are prepared. A method of sticking the pressure-sensitive adhesive layer 48 to the exposed foamable layer 45, if necessary, except for one transparent layer 1 of the pair of transparent layers 1 may be mentioned.

Among the preparation methods of such a processed sheet 49, preferably, after removing one transparent layer 1 from the foamable sheet 50, a method of attaching the adhesive layer 48 to the exposed foamable layer 45 can be mentioned. . And as shown in FIG. 11, this method is preferably carried out continuously by the sheet manufacturing apparatus 51 in a roll-to-roll manner.

The sheet manufacturing apparatus 51 includes a first rotating shaft 52, a second rotating shaft 53, a winding shaft 54, and a plurality (three) of rollers 55.

The first rotating shaft 52 has a substantially cylindrical shape and is configured to be rotatable around the axis. As described later, the foamable sheet 50 is wound around the first rotating shaft 52.

The second rotating shaft 53 is arranged at an upper right side with respect to the first rotating shaft 52 in FIG.

The second rotating shaft 53 has a substantially cylindrical shape extending in the same direction as the first rotating shaft 52, and is configured to be rotatable around the axis. As will be described later, an adhesive sheet 65 including an adhesive layer 48 is wound around the second rotating shaft 53.

In FIG. 11, the take-up shaft 54 is disposed on the right side with a space from the first rotation shaft 52, and is disposed on the lower right side with a space from the second rotation shaft 53. Yes.

The winding shaft 54 has a substantially cylindrical shape extending in the same direction as the first rotation shaft 52, and is configured to be rotatable around the axis. Although the winding shaft 54 will be described later, the prepared processed sheet 49 is wound thereon.

Each of the plurality of rollers 55 extends in the same direction as the first rotating shaft 52 and is appropriately disposed at a predetermined position.

In order to continuously prepare the processed sheet 49 using such a sheet manufacturing apparatus 51, first, the long and flat strip-like foamable sheet 50 is wound around the first rotating shaft 52 in a spiral shape. As a result, the foamable sheet 50 is configured as a foamed sheet roll 56 centered on the first rotation shaft 52.

The foamable sheet 50 includes a foamable layer 45 and a pair of transparent layers 1 that sandwich the foamable layer 45 in the thickness direction.

Such a foamable sheet 50 may be a commercially available product, such as Riva Alpha No 3196 (single-sided adhesive type, manufactured by Nitto Denko Corporation).

In the foam sheet roll 56, the foamable sheet 50 is disposed adjacent to the radial direction of the first rotation shaft 52. When the foamable sheet 50 is configured as a foamed sheet roll 56, the foamable sheet 50 includes a release treatment layer interposed between the radially outer transparent layer 1 and the foamable layer 45.

Also, a long and flat strip-shaped adhesive sheet 65 is wound around the second rotating shaft 53 in a spiral shape. Accordingly, the adhesive sheet 65 is configured as an adhesive sheet roll 57 centered on the second rotation shaft 53.

The pressure-sensitive adhesive sheet 65 includes a pressure-sensitive adhesive layer 48 and a separator 66 disposed on one surface of the pressure-sensitive adhesive layer 48. A release treatment layer is provided on both surfaces of the separator 66.

Commercially available products can be used as the pressure-sensitive adhesive sheet 65, such as Luciax CS9862US (manufactured by Nitto Denko Corporation), HJ-9150W (manufactured by Nitto Denko Corporation), and the like.

In the pressure-sensitive adhesive sheet roll 57, the pressure-sensitive adhesive sheet 65 is arranged adjacent to each other in the radial direction of the second rotation shaft 53, the pressure-sensitive adhesive layer 48 is arranged on the outer side in the radial direction, and the separator 66 is arranged on the inner side in the radial direction. Yes.

Next, the foamable sheet 50 is pulled out from the foamed sheet roll 56 and the radially outer transparent layer 1 is peeled from the foamable sheet 50.

Then, the pressure-sensitive adhesive sheet 65 is pulled out from the pressure-sensitive adhesive sheet roll 57, and the pressure-sensitive adhesive layer 48 of the pressure-sensitive adhesive sheet 65 is exposed to the exposed foamable layer 45 of the foamable sheet 50 (the surface opposite to the transparent layer 1 in the foamable layer 45). Paste. As a result, a long and flat belt-like processed sheet 49 is prepared.

Thereafter, the end portion of the processed sheet 49 is fixed to the take-up shaft 54, and the take-up shaft 54 is rotated in the clockwise direction when viewed from the front side of the sheet of FIG. Then, the processed sheet 49 is wound around the winding shaft 54 and wound around the winding shaft 54 in a spiral shape to form a roll.

As a method of cutting out the unit film 47 from such a processed sheet 49, for example, the same method as the method of cutting out the transparent layer 1 from the processed sheet 4 can be mentioned. Preferably, as shown in FIG. A method of cutting out a plurality of unit films 47 from a portion drawn from the sheet 49 can be mentioned.

Then, a plurality of unit films 47, 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 cut out from the processed sheet 49.

Then, if necessary, the separator 66 is peeled from each of the plurality of unit films 47 (see FIG. 11).

Next, as shown in FIG. 13, a plurality of unit films 47 are laminated in the thickness direction to prepare a laminate 46 (second step).

More specifically, a plurality of unit films 47 are laminated in the laminating direction so that the transparent layer 1 and the foamable layer 45 are adjacent to each other in the laminating direction (via an adhesive layer 48 if necessary). Moreover, when the unit film 47 has the adhesive layer 48, the laminated body 46 has the adhesive layer 48 arrange | positioned between the transparent layer 1 and the foamable layer 45 which are adjacent to the lamination direction. Yes. Therefore, the transparent layer 1 and the foamable layer 45 adjacent in the stacking direction are bonded to each other by the pressure-sensitive adhesive layer 48.

As described above, the cylindrical laminated body 46 extending in the laminating direction is prepared.

In FIG. 13, for convenience, the number of unit films 47 is omitted, and the laminated body 46 is described as six unit films 47, but actually, the laminated body 46 is, for example, 300 to 60000 sheets, preferably 500 to 30000 sheets, more preferably 500 to 10,000 unit films 47 are laminated.

The height (length in the stacking direction) of the stacked body 46 is the same as the height of the stacked body 2, for example.

Moreover, the laminated body 46 is thermocompression-bonded (hot press) under the same conditions as the thermocompression-bonding conditions as necessary.

Next, the substantially cylindrical laminated body 46 is rotated about the axis to continuously cut the side layer 58 of the laminated body 46 (cutting step).

More specifically, the cutting blade 11 is arranged along the stacking direction, and the stacked body 46 is rotated around its axis, and the side layer 58 is cut out from the stacked body 46 like a wig.

The cutting film 60 is cut out from the laminated body 46 by the above.

The cutting film 60 is a side layer 58 cut out from the laminated body 46 and is formed in a thin film shape. As shown in FIG. 14, the cutting film 60 includes a plurality of transparent layers 1 and a plurality of foamable layers 45, and further includes a plurality of adhesive layers 48 as necessary. And the transparent layer 1, the foamable layer 45, and the adhesive layer 48 are sequentially repeated so that they may continue in the lamination direction (the surface direction orthogonal to the thickness direction as the cutting film 60).

The plurality of foamable layers 45 are arranged in parallel at equal intervals (the thickness of the transparent layer 1 and the pressure-sensitive adhesive layer 48) from each other in the stacking direction. Extending so as to be orthogonal.

Further, the thickness of the cutting film 60 is the same as the thickness of the film body 21, for example. Moreover, said adhesive layer 24 can also be provided in the one surface of the lighting film 40 as needed.

Then, after the cutting step, the foamable layer 45 included in the cutting film 60 is foamed to obtain a foam layer 61 capable of scattering light (foaming step).

In order to foam the foamable layer 45, for example, the cutting film 60 is heated by a heating device.

Examples of the heating device include known heating devices such as an oven, a hot plate, a hot air dryer, a near infrared lamp, and preferably an oven.

The heating temperature is not less than the foaming start temperature of the foaming agent contained in the foamable layer 45 and is, for example, 90 ° C. or more, preferably 100 ° C. or more, for example, 250 ° C. or less, preferably 170 ° C. or less.

The heating time is, for example, 5 seconds or more, preferably 10 seconds or more, for example, 15 minutes or less, preferably 10 minutes or less.

Thereby, the foaming agent in the foamable layer 45 is foamed, and the foamable layer 45 becomes a foam layer 61 having pores 62 inside.

The volume expansion ratio of the foam layer 61 is, for example, 1.1 times or more, preferably 5 times or more, for example, 50 times or less, preferably 30 times or less.

The porosity of the foam layer 61 (ratio of voids in the porous layer) is, for example, 10% by volume or more, preferably 30% by volume or more, for example, 90% by volume or less, preferably 80% by volume or less.

The thickness of the foam layer 61 is, for example, 10 μm or more, preferably 20 μm or more, for example, 100 μm or less, preferably 80 μm or less.

The ratio of the thickness of the foam layer 61 to the thickness of the transparent layer 1 (the thickness of the foam layer 61 / the thickness of the transparent layer 1) is, for example, 2/1 or more, preferably 1/1 or more, for example, 1/2 or less, preferably 1/4 or less.

By the above, the foamable layer 45 in the cutting film 60 becomes the foam layer 61, and the daylighting film 63 is prepared.

That is, the daylighting film 63 includes a plurality of transparent layers 1 and a plurality of foam layers 61, and further includes a plurality of adhesive layers 48 as necessary. The transparent layer 1, the foam layer 61, and the pressure-sensitive adhesive layer 48 are sequentially and repeatedly arranged so that they are continuous in the stacking direction (the surface direction orthogonal to the thickness direction as the cutting film 60).

In the third embodiment, as shown in FIG. 14, the foamable layer 45 is foamed to form the foam layer 61 capable of scattering light, so that an optical film that can scatter light reliably can be manufactured. .

Further, in the foaming process performed after the cutting process, the foamable layer 45 included in the cutting film 60 is foamed. Therefore, it can suppress that the foam layer 61 peels from the transparent layer 1 or the adhesive layer 48 which adjoins the foam layer 61 mutually.

Further, as shown in FIG. 13, a plurality of unit films 47 each including the transparent layer 1 and the foamable layer 45 are laminated to form a laminate 46, so that each of the plurality of transparent layers 1 and the plurality of foamable layers 45 is formed. As compared with the case where the stacked body 46 is formed by stacking layers, the preparation process can be facilitated.

Further, as shown in FIG. 13, in the laminated body 46, the transparent layer 1 and the foamable layer 45 that are adjacent to each other are bonded by the adhesive layer 48, so that the transparent layer 1 and the foamable layer that are adjacent to each other can be foamed in the cutting step. It can suppress that the layer 45 peels and separates.

In addition, as shown in FIG. 12, in the preparation step, a plurality of unit films 47 each including the transparent layer 1, the foamable layer 45, and the pressure-sensitive adhesive layer 48 are laminated to form a laminated body 46. While the agent layer 48 can be provided, the preparation process can be facilitated.

Also in the third embodiment, the same operational effects as those of the first embodiment described above can be achieved.

The daylighting film 63 manufactured in this way is attached to, for example, the inner surface of the glass window 26 in a building such as the house 25 in the same manner as in the first and second embodiments (see FIG. 10).

When light (for example, sunlight) is incident on the daylighting film 63 attached to the glass window 26, the light is scattered by being reflected by the pores 62 in the foam layer 61, and enters the house 25. It is introduced (see FIG. 10).

Therefore, according to the daylighting film 63, the daylight can be efficiently taken, and the brightness of the entire house 25 can be improved efficiently.

In the third embodiment, as shown in FIG. 12, a plurality of unit films 47 in which the transparent layer 1 and the foamable layer 45 are integrally laminated are prepared, and the laminate 46 is obtained by laminating them. Although prepared, the laminated body 46 can also be prepared by preparing each of the transparent layer 1 and the foamable layer 45 separately and laminating them.

In the third embodiment, as shown in FIG. 13, the foaming step is performed after the cutting step, but the foaming step can be performed before the cutting step and after the preparation step. In this case, the foamable layer 45 included in the laminated body 46 is foamed to become the foam layer 61.

In the third embodiment, as shown in FIG. 13, the unit film 47 includes an adhesive layer 48 in addition to the transparent layer 1 and the foamable layer 45, but the unit film 47 includes an adhesive layer 48. Instead, it may consist only of the transparent layer 1 and the foamable layer 45. In this case, it is preferable to form the pressure-sensitive adhesive layer 48 between the unit films 47 adjacent to each other in the stacking direction when the plurality of unit films 47 are stacked in the preparation step.

In the first to third embodiments, as shown in FIGS. 5 and 9, the daylighting film includes the adhesive layer 24, but the present invention is not limited thereto, and the daylighting film includes the adhesive layer 24. It does not have to be provided. In this case, an adhesive or a pressure-sensitive adhesive is applied to the inner surface of the glass window 26 to form an adhesive layer 24, and a lighting film is attached to the adhesive layer 24.

Even in such a modification, the same operational effects as those of the first to third embodiments can be obtained.

Note that each of the first to third 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. 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
A satin type polyvinyl chloride film (processed sheet, manufactured by Okamoto Co., Ltd., satin clear # 320) having a thickness of 100 μm was punched into a circular shape with a diameter of 25 cm to produce 1000 circular transparent layers. Each of both surfaces in the thickness direction of each transparent layer was formed as an uneven surface. The relative refractive index of the polyvinyl chloride film with respect to air was 1.54.

Next, 1000 transparent layers were laminated without using an adhesive between the transparent layers to obtain a non-adhesive laminate. And the laminated body was hold | maintained in the column shape by applying a pressure (5 Mpa) from the both sides of the lamination direction (preparation process). The laminate was 25 cm in diameter × height (length in the stacking direction) 100 mm (100 μm × 1000 sheets).

Next, the laminate and the transparent support were set in the cutting device 13 shown in FIG.

Specifically, the laminate was held by a pair of holding members 15 so as to be sandwiched from both sides in the lamination direction, and the transparent support was wound around the rotating shaft 14 to constitute a support roll.

At this time, the pair of holding members 15 sandwiched the laminated body from both sides in the laminating direction at the pressure (5 MPa). Further, the transparent support had a polypropylene film (base material) having a thickness of 40 μm and an acrylic pressure-sensitive adhesive layer (adhesion 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 15, the tip of the cutting blade 11 is in contact with the side surface of the laminated body. In addition, the cutting blade 11 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 on the side of the laminate in the range of the central angle of 240 ° in the laminate. Affixed (applying step).

Subsequently, the pair of holding members 15 were driven to rotate counterclockwise by a motor (not shown) of the cutting device 13 when viewed from one axial direction of the holding member 15 (front side in FIG. 8). .

Then, the laminated body held by the pair of holding members 15 was rotated about the axis, and the support roll was driven about the axis of the rotating shaft 14.

Thereby, the side layer of the laminated body to which the support was stuck was continuously cut out like a wig, and the film main body (side layer of the laminated body) supported by the transparent support was obtained (cutting step). .

Thereafter, Luciax CS9862US (manufactured by Nitto Denko Corporation) (adhesive) was applied to the surface (cut surface) opposite to the transparent support of the film body to form an adhesive layer.

As described above, a long and flat strip-shaped daylighting film was prepared which was provided with a film body, a transparent support and an adhesive layer. In the film body, the plurality of transparent layers were continuously arranged in the laminating direction (the surface direction of the film body). The film body had a thickness of 250 μm.

Then, the daylighting film was appropriately cut according to the size of the glass window to be attached. Thus, specifically, a daylighting film having a rectangular shape in a plan view having a long side of 78 cm and a short side of 10.8 cm was obtained.

As shown in FIG. 6, when such a daylighting film was attached to the inner surface of the glass window 26, efficient daylighting was confirmed.

Example 2
A 300 μm thick EVA film (first processed sheet, manufactured by Bridgestone Corporation) was punched into a circular shape with a diameter of 25 cm to produce 500 circular transparent layers. Each of both surfaces in the thickness direction of each transparent layer was formed as a flat surface. The relative refractive index of the ethylene vinyl acetate copolymer film with respect to air was 1.54.

Further, a porous PET film having a thickness of 40 μm (second processed sheet, manufactured by Toray Industries Inc., Lumirror EA3S) was punched into a circular shape having a diameter of 25 cm, and 500 circular porous layers were produced. The relative refractive index of PET with respect to air was 1.60.

Next, 500 transparent layers and 500 porous layers were alternately laminated without using an adhesive between the respective layers to obtain a non-adhesive laminate. And the laminated body was thermocompression-bonded for 15 minutes by the compression molding machine on conditions of 100 degreeC and 1 Mpa. As a result, the transparent layer was fused to the adjacent porous layer to obtain an integrated laminate (preparation step). The laminated body had a diameter of 25 cm × a height (a stacking direction length) of 170 mm (300 μm × 500 sheets + 40 μm × 500 sheets).

Next, as shown in FIG. 8, the cutting blade 11 was arranged along the stacking direction of the laminate, and the tip of the cutting blade 11 was brought into contact with the side surface of the laminate. And the laminated body was rotationally driven clockwise as seen from one side of the lamination direction.

Thus, the side layer of the laminate was continuously cut out like a wig to obtain a film body (side layer of the laminate) (cutting step).

Thereafter, Luciax CS9862US (manufactured by Nitto Denko Corporation) (adhesive) was applied to one of the surfaces of the film body to form an adhesive layer.

As described above, a long and flat strip-shaped daylighting film having a film body and an adhesive layer was prepared. In the film main body, the plurality of transparent layers and the plurality of porous layers were continuously arranged so as to alternate with each other in the stacking direction (the surface direction of the film main body). The film body had a thickness of 300 μm.

When such a daylighting film was used by being attached to the inner surface of the glass window 26 as shown in FIG. 10, efficient daylighting was confirmed.

Example 3
A long and flat strip-like foamable sheet (Riva Alpha No. 3196, manufactured by Nitto Denko Corporation) and a long and flat strip-shaped adhesive sheet (Luciax CS9862US, manufactured by Nitto Denko Corporation) were prepared.

The foamable sheet was provided with a foamable layer and a pair of transparent layers sandwiching the foamable layer. The transparent layer of the foamable sheet was formed from PET and had a thickness of 100 μm. The foamable layer 45 contained an acrylic pressure-sensitive adhesive and thermally expandable microspheres, and the thickness thereof was 40 μm.

The pressure-sensitive adhesive sheet was provided with a pressure-sensitive adhesive layer and a separator. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet was a substrate-less double-sided pressure-sensitive adhesive tape, and the thickness thereof was 50 μm.

Next, the foamable sheet and the substrate-less double-sided adhesive tape were set in the sheet manufacturing apparatus 51 shown in FIG.

Specifically, the foamable sheet was wound around the first rotating shaft 52 to form a foamed sheet roll, and the adhesive sheet was wound around the second rotating shaft 53 to form an adhesive sheet roll. In the foam sheet roll, a release treatment layer with a release treatment agent was provided between the transparent layer on the radially outer side of the foamable sheet and the foamable layer. Moreover, the peeling process layer was provided in both surfaces of the separator of the adhesive sheet.

Next, the foamable sheet was pulled out from the foamed sheet roll, and the radially outer transparent layer was peeled from the foamable sheet. And the adhesive sheet was pulled out from the adhesive sheet roll, and the adhesive layer was affixed on the foamable layer which the foamable sheet exposed. Thereby, a long and flat strip-shaped processed sheet was prepared.

Thereafter, the end of the processed sheet was fixed to the take-up shaft 54, and the take-up shaft 54 was rotated in the clockwise direction when viewed from the front side of the sheet of FIG. As a result, the processed sheet was wound around the winding shaft 54 in a spiral shape to form a roll.

Thereafter, a roll-shaped processed sheet was drawn out, and the processed sheet was punched into a circular shape having a diameter of 25 cm to produce 500 circular unit films (first step).

Next, after separating the separator from each unit film, 500 unit films were laminated to obtain a laminate (preparation step, second step). In the laminate, the transparent layer, the foamable layer, and the pressure-sensitive adhesive layer were sequentially and repeatedly arranged in the lamination direction.

Then, the laminate was pressure-bonded for 3 minutes using a compression molding machine under conditions of room temperature and 1 MPa. The laminate had a diameter of 25 cm × a height (a length in the lamination direction) of 95 mm.

Next, as shown in FIG. 13, the cutting blade 11 was disposed along the stacking direction of the laminate, and the tip of the cutting blade 11 was brought into contact with the side surface of the laminate. And the laminated body was rotationally driven clockwise as seen from one side of the lamination direction.

Thereby, the side layer of the laminate was continuously cut out like a wig to obtain a cutting film (side layer of the laminate) (cutting step). The thickness of the cutting film was 150 μm.

Next, the cutting film was heated in an oven at 100 ° C. for 1 minute to foam the foamable layer in the cutting film to obtain a foam layer. The thickness of the foam layer was 60 μm.

Thus, a long and flat strip-shaped daylighting film was prepared. In the daylighting film, the transparent layer, the foam layer, and the pressure-sensitive adhesive layer were continuously arranged so as to be sequentially repeated in the laminating direction (the surface direction of the daylighting film).

Thereafter, Luciax CS9862US (manufactured by Nitto Denko Corporation) (adhesive) was applied to one surface of the daylighting film to form an adhesive layer.

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 method for producing an optical film of the present invention is used, for example, for producing a daylighting film used for daylighting of a building.

DESCRIPTION OF SYMBOLS 1 Transparent layer 2 Laminated body 3 Uneven surface 5 Laminate side surface 6 Support body 9 Laminate side surface layer 16 Support body roll 20 Daylighting film 40 Daylighting film 45 Foamable layer 46 Laminate body 47 Unit film 48 Adhesive layer 58 Laminate body Side layer 60 Cutting film 61 Foam layer 63 Daylighting film

Claims

A plurality of transparent layers capable of transmitting light and a plurality of light scattering layers capable of light scattering are laminated in the thickness direction of each of the plurality of transparent layers, and the substantially cylindrical laminate extending in the thickness direction. A preparation process to prepare,
A method for producing an optical film, comprising: a step of continuously cutting a side layer of the laminate by rotating the laminate around an axis.
The method for producing an optical film according to claim 1, wherein the plurality of light scattering layers are capable of light scattering.
Each of the plurality of light scattering layers is an uneven surface disposed on at least one surface of each of the plurality of transparent layers,
3. The method for producing an optical film according to claim 2, wherein in the preparation step, each of the plurality of transparent layers having the uneven surface is laminated in the thickness direction to form the laminate. .
Between the preparation step and the cutting step, further comprising an attaching step of attaching a support to the side surface of the laminated body along the thickness direction,
In the preparation step, the plurality of transparent layers are laminated so that the uneven surface and the transparent layer laminated on the uneven surface are in direct contact with each other,
The method for producing an optical film according to claim 3, wherein in the cutting step, the side layer of the laminate to which the support is attached is continuously cut.
The support is in the form of a sheet and is configured as a support roll by being wound;
In the attaching step, the support drawn from the support roll is attached to the side surface of the laminate,
In the cutting step, the support roll is rotated about the axis, and the laminate is rotated about the axis to continuously cut the side layer of the laminate to which the support is attached. The manufacturing method of the optical film of Claim 4 characterized by the above-mentioned.
The method for producing an optical film according to claim 2, wherein each of the plurality of light scattering layers is a porous layer having a plurality of pores therein.
The said preparation process WHEREIN: Each of these transparent layers and each of these porous layers are alternately laminated | stacked, The said laminated body is formed, It is characterized by the above-mentioned. Manufacturing method of optical film.
In the preparation step,
Laminating each of the plurality of transparent layers and each of the plurality of porous layers so as to be in direct contact with each other;
The method for producing an optical film according to claim 7, wherein the laminate is pressed from both sides in the thickness direction and heated to 30 ° C. or higher and 180 ° C. or lower.
Each of the plurality of light scattering layers is made of a foamable foamable material, and is a foamable layer that can be scattered by foaming,
The method for producing an optical film according to claim 1, further comprising a foaming step of foaming the foamable layer to form a light-scatterable foam layer.
The foaming step is performed after the cutting step,
In the cutting step, the side layer of the laminate is continuously cut to cut out a cutting film,
The method for producing an optical film according to claim 9, wherein, in the foaming step, the foamable layer included in the cutting film is foamed.
The preparation step includes
A first step of preparing a plurality of unit films comprising the transparent layer and the foamable layer disposed on one surface in the thickness direction of the transparent layer;
The method for producing an optical film according to claim 9, further comprising a second step of laminating the plurality of unit films in the thickness direction to form the laminate.
In the laminate, each of the plurality of transparent layers and each of the plurality of foamable layers are arranged to be adjacent to each other in the thickness direction,
The said laminated body has an adhesive layer arrange | positioned between the said mutually adjacent transparent layer and foamable layer, The manufacturing method of the optical film of Claim 11 characterized by the above-mentioned.
The method for producing an optical film according to claim 12, wherein the unit film further includes the pressure-sensitive adhesive layer disposed on one surface in the thickness direction of the foamable layer.
A daylighting film produced by the method for producing an optical film according to claim 1.