JP2014235380A - Optical film manufacturing method and lighting film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film manufacturing method capable of improving productivity although the method is simple, and a lighting film manufactured by the manufacturing method.SOLUTION: An optical film manufacturing method comprises: preparing a plurality of unit films 2 provided with transparent layers 3 and removal material layers 4; laminating the plurality of unit films 2 in a thickness direction of the transparent layers 3 to form a laminate 5; and then, cutting the laminate 5, so that the transparent layers 3 and the removal material layers 4 continue in the thickness direction, to make a lighting film 1.

Description

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

  2. Description of the Related Art Conventionally, so-called daylighting (also referred to as sunlight illumination or daylight illumination) is known in which sunlight is introduced into a room in order to adjust the environment such as the brightness of a room in a building. 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 film 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.

  Such an optical film includes, for example, a translucent support, a plurality of unit prisms formed on the support, and a protective film provided so as to cover the plurality of unit prisms. There has been proposed a daylighting film in which a reflective layer capable of reflecting light is provided on a part of the surface (for example, see Patent Document 1).

  And such a daylighting film is installed in windows, such as a house, for example, and the reflection layer of a unit prism reflects the sunlight which injected from the outdoors through a window, and takes light.

JP 2008-40025 A

  However, in order to manufacture the daylighting film described in Patent Document 1, for example, first, a sheet-shaped resin material (support) is pressed against a transfer roller on which a plurality of unit prism reversal types are formed on the surface. Thus, a plurality of unit prisms are formed on the support. Next, after a reflective layer is formed by vapor-depositing a metal or the like on a part of the surface of each unit prism, the plurality of unit prisms on which the reflective layer is formed are covered with a transmissive protective film.

  However, such a daylighting film manufacturing method requires an expensive transfer roller, and the process of forming a reflective layer on a part of each unit prism is complicated. However, there is a problem that the productivity of the daylighting film is low.

  Accordingly, 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.

  In order to achieve the above-described object, the method for producing an optical film of the present invention includes a transparent layer configured to transmit light, and at least one surface in the thickness direction of the transparent layer, and reflects light. A step of preparing a plurality of unit films each having a reflective layer configured as described above, a step of laminating a plurality of the unit films in the thickness direction to form a laminate, and the laminate as the transparent layer. And a step of cutting the reflective layer so as to be continuous in the thickness direction.

  According to such a manufacturing method, a plurality of unit films each including a transparent layer and a reflective layer are laminated to form a laminate, and then the laminate is cut so that the transparent layer and the reflective layer are formed of the laminate. An optical film continuous in the thickness direction can be produced.

  That is, first, if a plurality of unit films including a transparent layer and a reflective layer are prepared, the transparent layer and the reflective layer are continuously formed in the thickness direction of the laminate by a simple method of laminating and cutting the unit films. An optical film can be manufactured.

  Therefore, the productivity of the optical film in which the transparent layer and the reflective layer are continuous can be improved. As a result, it can be suitably used as an industrial production method for optical films.

  Moreover, the lighting film of this invention is manufactured by the manufacturing method of said optical film, It is characterized by the above-mentioned.

  According to such a structure, since it can manufacture with said manufacturing method of an optical film, it can manufacture simply and efficiently.

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

FIG. 1 is a perspective view of an embodiment of a unit film according to the method for producing an optical film of the present invention (an embodiment having a rectangular shape when viewed from the thickness direction). FIG. 2 is a perspective view of a laminate formed by laminating the unit films shown in FIG. FIG. 3 is a perspective view of a daylighting film cut out from the laminate shown in FIG. FIG. 4 is a perspective view of another embodiment of the unit film according to the method for producing an optical film of the present invention (an embodiment having a circular shape when viewed from the thickness direction). FIG. 5 is a perspective view of a laminate formed by laminating the unit films shown in FIG. FIG. 6 is a schematic explanatory diagram for explaining a state in which the daylighting film shown in FIG. 3 is attached to the glass window.

  In the method for producing an optical film of the present invention, as shown in FIG. 1, first, a plurality of unit films 2 on which a transparent layer 3 and a reflective layer 4 are laminated are prepared (prepared).

  In order to prepare the unit film 2, for example, after forming the reflective layer 4 on the surface of the transparent layer 3 (one surface in the thickness direction) to prepare a processed sheet, the unit film 2 having a predetermined shape is prepared from the processed sheet. Cut out. Alternatively, the unit film 2 may be formed by forming the reflective layer 4 on the surface of the transparent layer 3 processed into a predetermined shape.

  The transparent layer 3 is configured to transmit light, and is preferably formed in a sheet shape from 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, fluororesin, urethane resin, and the like, preferably polyester and polyvinyl chloride. Such organic materials may be used alone or in combination of two or more.

The thickness of the transparent layer 3 can be appropriately changed according to 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 (10 ⁴ μm) or less, preferably Is 1 mm (10 ³ μm) or less, more preferably 500 μm or less.

  The ratio of the thickness of the transparent layer 3 to the thickness of the reflective layer 4 (the thickness of the transparent layer 3 / the thickness of the reflective layer 4) is, for example, 10 or more, preferably 100 or more, for example, 100,000 or less, 2000 or less, more preferably 1000 or less. If the ratio of the thickness of the transparent layer 3 to the thickness of the reflective layer 4 is within the above range, in the daylighting film 1 to be described later, each reflective layer 4 can be arranged at a suitable interval in the stacking direction, An efficient arrangement of the reflective layers 4 can be ensured.

  The light transmittance of the transparent layer 3 is, for example, 90% or more, preferably 94% or more, more preferably 95% with respect to light having a wavelength of 440 to 600 nm when the thickness of the transparent layer 3 is 100 μm. % Or more, for example, 98% or less.

  Further, the relative refractive index of the transparent layer 3 with respect to the refractive index of air is, for example, 1.4 or more, preferably 1.45 or more, for example, 1.8 or less, preferably 1.65 or less. The refractive index can be measured with a prism coupler.

  The reflective layer 4 is configured to reflect light, and is preferably formed in a thin film shape from a metal material from the viewpoint of improving reflectivity.

  Examples of the metal material forming the reflective layer 4 include metal elements (for example, gold, silver, copper, iron, aluminum, chromium, nickel, etc.), alloys composed of a plurality of metal elements, and the like. Silver, aluminum, and an alloy containing them are mentioned, More preferably, aluminum is mentioned. Such a metal material may be used as a single thin film, or two or more thin films may be laminated.

The thickness of the reflective layer 4 is not particularly limited as long as light can be sufficiently reflected, but is, for example, 20 nm or more, preferably 30 nm or more, for example, 10 μm (10 ⁴ nm) or less, preferably 1 μm. (10 ³ nm) or less, more preferably 300 nm or less.

  Moreover, the reflectance (incident angle 5 °) of the reflective layer 4 is, for example, 80% or more, preferably 85% or more, for example, 96% or less, preferably 95%, with respect to light having a wavelength of 440 to 600 nm. It is as follows.

  Examples of the method for forming the reflective layer 4 on the surface of the transparent layer 3 include known film forming methods, such as a dry process and a wet process. Examples of the dry process include physical vapor deposition (for example, vacuum vapor deposition, sputtering, ion plating, etc.), chemical vapor deposition, aerosol deposition, and the like. Examples of the wet process include the above metals. Examples thereof include a method of applying a solution containing the material to the surface of the transparent layer 3 and a plating method.

  Among these film forming methods, a dry process is preferable, a physical vapor deposition method is more preferable, and a vacuum vapor deposition method is particularly preferable.

  Moreover, in the unit film 2, the reflective layer 4 may be formed on the back surface (the other surface in the thickness direction) of the transparent layer 3 by the same method as described above, as indicated by phantom lines in FIG.

  Examples of the method for cutting out the unit film 2 from the processed sheet or the method for cutting the transparent layer 3 into a predetermined shape include known processing methods such as cutting and punching.

  In addition, the shape of the unit film 2 is not particularly limited, and the unit film 2 is, for example, multi-layered by the above processing method as viewed from the lamination direction of the transparent layer 3 and the reflective layer 4 (thickness direction of the transparent layer 3). It is formed in a rectangular or circular shape, preferably a rectangular or circular shape, particularly preferably a square (see FIG. 1), rectangular or circular shape (see FIG. 4).

  The size of the unit film 2 is appropriately changed according to the purpose of use. When the unit film 2 has a rectangular shape (square shape) when viewed from the laminating direction (see FIG. 1), each of the sides is For example, when the unit film 2 has a circular shape from the lamination direction (see FIG. 4), the diameter is, for example, 10 cm to 1 m (100 cm).

The area of the unit film 2, for example, 25 cm ² or more, preferably, 2500 cm ² or more, for example, 40000Cm ² or less, or preferably 10000 cm ² or less.

  A plurality of such unit films 2 are prepared, for example, 500 sheets or more, preferably 1000 sheets or more, for example, 50000 sheets or less, preferably 10,000 sheets or less.

  In order to prepare a plurality of unit films 2, for example, a processed sheet may be formed large so that a plurality of unit films 2 can be cut out, and a plurality of unit films 2 may be cut out from the processed sheet. The unit film 2 may be cut out one by one from each processed sheet. Each of the plurality of unit films 2 is preferably formed in the same shape and size.

  Next, as shown in FIGS. 2 and 5, a plurality of unit films 2 are laminated in the lamination direction (thickness direction) to prepare a laminate 5.

  More specifically, each of the plurality of unit films 2 is laminated in the lamination direction so that the transparent layer 3 and the reflective layer 4 are sequentially repeated in the lamination direction. 2 and 5, for convenience, the number of unit films 2 is omitted, and it is described that the laminated body 5 is composed of four unit films 2. 5 is formed by laminating, for example, 500 to 50,000 unit films, preferably 1000 to 10000 unit films 2.

  Moreover, when each unit film 2 is formed in the same shape and size, the plurality of unit films 2 are laminated so as to coincide when projected in the lamination direction.

  In the laminate 5, an adhesive layer is preferably provided between the unit films 2 adjacent to each other in the lamination direction.

  In the case where the transparent layer 3 is formed only on one surface of the reflective layer 4 and the transparent layer 3 has sufficient tackiness, such an adhesive layer is reflected on the transparent layer 3 of the unit film 2 adjacent to each other. Although it is not particularly necessary because the layer 4 is securely adhered to the transparent layer 3, the reflective layer 4 is formed on both surfaces of the transparent layer 3 (see the phantom line in FIG. 1), and the adhesiveness of the transparent layer 3 is insufficient. In such a case, it is provided to bond the transparent layer 3 and the reflective layer 4 of the unit films 2 adjacent to each other.

  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.

  In order to provide an adhesive layer on the laminate 5, before laminating the plurality of unit films 2, the surface (one surface in the thickness direction) of the reflective layer 4 and / or the back surface of the transparent layer 3 ( After the adhesive is applied to the other surface in the thickness direction, each unit film 2 coated with the adhesive is laminated.

  Moreover, the laminated body 5 is thermocompression-bonded (heating press) as needed.

  As conditions for thermocompression bonding, the temperature is, for example, 30 ° C. or more, preferably 50 ° C. or more, for example, 180 ° C. or less, preferably 150 ° C. or less, and the pressure 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, and the time is, for example, 5 minutes or more, preferably 30 minutes or more, for example, 180 minutes or less, preferably 60 minutes or less.

  As described above, the columnar (block-shaped) stacked body 5 extending in the stacking direction is formed. More specifically, when the unit film 2 is rectangular when viewed from the stacking direction, a prismatic stacked body 5 is formed (see FIGS. 1 and 2), and the unit film 2 is circular when viewed from the stacking direction. In some cases, a cylindrical laminate 5 is formed (see FIGS. 4 and 5).

  The height (the length in the stacking direction) of the stacked body 5 is, for example, 10 cm or more, preferably 40 cm or more, for example, 100 cm or less, preferably 80 cm or less.

  Next, as shown in FIGS. 2 and 5, the laminated body 5 is cut so that the transparent layer 3 and the reflective layer 4 are continuous in the laminating direction (thickness direction), and the daylighting film 1 as an example of an optical film is obtained. To prepare.

  The cutting method for cutting the laminate 5 is not particularly limited as long as the daylighting film 1 can be cut out from the laminate 5.

  For example, when the laminated body 5 has a prismatic shape, as shown by a solid line in FIG. 2, the cutting blade 8 is arranged so that the cutting direction is perpendicular to the laminating direction and the cutting direction is along the laminating direction. A method of cutting out the daylighting film 1 using a plane or, as shown by a virtual line in FIG. 2, the cutting blade 8 is arranged along the lamination direction so that the cutting direction is orthogonal to the lamination direction of the laminate, The method of cutting out the lighting film 1 from the laminated body 5 using a plane is mentioned.

  Further, when the laminate 5 is cylindrical, as shown in FIG. 5, the cutting blade 8 is disposed along the lamination direction, and the laminate 5 is rotated about its axis to obtain the laminate 5. A method of cutting out the daylighting film 1 like a wig is described.

  Thus, the daylighting film 1 is cut out from the laminate 5.

  Such a daylighting film 1 has a plurality of transparent layers 3 and a plurality of reflection layers 4 as shown in FIG. 3, and in the laminating direction (surface direction perpendicular to the thickness direction as the daylighting film 1), The transparent layer 3 and the reflective layer 4 are sequentially and repeatedly arranged so as to be continuous. The plurality of reflective layers 4 are arranged in parallel at equal intervals (the thickness of the transparent layer 3) in the stacking direction (the surface direction of the daylighting film 1). It extends over the entire daylighting film 1 so as to be orthogonal to the surface direction of the daylighting film 1.

The thickness of the daylighting film 1 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 mm (10 ⁴ μm) or less, preferably 2 mm ( 10 ³ μm) or less, more preferably 500 μm or less, and particularly preferably 300 μm or less. The thickness of the daylighting film 1 can be adjusted as appropriate depending on the arrangement and angle of the cutting blade 8 with respect to the laminate 5 when the laminate 5 is cut.

  According to the manufacturing method of such a daylighting film 1, as shown in FIGS. 1-5, if the unit film 2 provided with the transparent layer 3 and the reflection layer 4 is prepared first, the unit film 2 will be shown. The daylighting film 1 can be manufactured by a simple method of stacking and cutting.

  Therefore, the productivity of the daylighting film 1 in which the transparent layer 3 and the reflective layer 4 are continuous in the thickness direction can be improved, and the daylighting film 1 can be manufactured easily and efficiently. As a result, it can be suitably used as an industrial manufacturing method for the daylighting film 1.

  The lighting film 1 manufactured in this way is attached to, for example, the inner surface of the glass window 11 in a building such as a house 10 as shown in FIG. Or you may attach so that it may be contained as an inner layer of a multilayer glass or a laminated glass.

  Then, a part of the light L1 (for example, sunlight) incident from the outside through the glass window 11 passes through the transparent layer 3 and proceeds toward the floor 12 of the house 10 through the glass window 11. The other portion of the light L2 is reflected by the reflective layer 4 and travels toward the ceiling portion 13 of the house 10.

  Therefore, according to the daylighting film 1, it can daylight efficiently and the improvement of the brightness of the whole house 10 can be aimed at.

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

Example 1
Aluminum was deposited on one side of a 180 μm thick polyvinyl chloride film (transparent layer) by a vacuum deposition method to form a metal reflective film (reflective layer). The thickness of the metal reflective film was 100 nm. Thus, a processed sheet was prepared.

  Next, the processed sheet (polyvinyl chloride film on which a metal reflection film was formed) was cut, and 3000 unit films each having a 50 cm length and 50 cm width were cut out from the processed sheet.

  Next, a plurality of unit films were laminated so that the polyvinyl chloride film and the metal reflective film were sequentially repeated. At this time, an adhesive (specifically, acrylic pressure-sensitive adhesive) was sandwiched between the unit films to form an adhesive layer of 5 μm.

  Next, the laminated unit films were thermocompression bonded for 30 minutes under conditions of 50 ° C. and 5 MPa to prepare a prismatic (block-shaped) laminate. The laminate was 50 cm long × 50 cm wide × height (length in the stacking direction) of 55.5 cm.

  Next, the stack was cut by placing the plane so that the cutting blade was orthogonal to the stacking direction of the laminate and the cutting direction was along the stacking direction of the stack (see FIG. 2).

  Thus, a daylighting film was prepared in which the transparent layer and the reflective layer were continuous in the laminating direction and each reflective layer was extended so as to be substantially orthogonal to the laminating direction. The daylighting film had a rectangular shape in plan view with a long side of 55.5 cm and a short side of 50 cm, and the thickness was 200 μm.

DESCRIPTION OF SYMBOLS 1 Daylight film 2 Unit film 3 Transparent layer 4 Reflective layer 5 Laminated body

Claims (2)

A step of preparing a plurality of unit films including a transparent layer configured to transmit light, and a reflective layer configured to reflect light at least on one surface in the thickness direction of the transparent layer;
A step of laminating a plurality of the unit films in the thickness direction to form a laminate;
A method for producing an optical film, comprising: cutting the laminate so that the transparent layer and the reflective layer are continuous in the thickness direction.   A daylighting film manufactured by the method for manufacturing an optical film according to claim 1.

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