JP2016129988A - Optical resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical resin sheet that hardly curls.SOLUTION: An optical resin sheet 1 includes a protective layer 2, an intermediate layer 3 laminated on the protective layer 2, and a gas barrier layer 4 laminated on the intermediate layer 3. The intermediate layer 3 includes a plurality of first and second flat yarns 3a, 3b comprising a plurality of uniaxially oriented synthetic resin films, in which the plurality of first flat yarns 3a and the plurality of second flat yarns 3b are bonded to intersect with each other. The protective layer 2, the intermediate layer 3 and the gas barrier layer 4 are joined by an adhesive 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical resin sheet for flexible electronic parts such as flexible solar cells.

  In recent years, development of flexible solar cells has attracted attention. For example, solar cells that are resistant to bending, such as calcobylite solar cells and organic solar cells, have been developed.

  In the following Patent Document 1, a flexible solar cell sealing sheet is disclosed. The sealing sheet described in Patent Document 1 is a laminate in which an adhesive layer is laminated on a fluororesin sheet.

International Publication No. 2012/046564

  However, in the sealing sheet of Patent Document 1, the thermal expansion coefficient and the like of the fluororesin sheet and the adhesive layer are different. For this reason, curling has occurred due to the thermal history during processing. Therefore, after applying the sealing sheet to the solar cell, stress was continuously applied. Therefore, the sealing sheet may peel from the solar cell.

  An object of the present invention is to provide an optical resin sheet that is difficult to curl.

  The optical resin sheet according to the present invention includes a protective layer, an intermediate layer laminated on the protective layer, and a gas barrier layer laminated on the intermediate layer, and the intermediate layer is made of a synthetic resin film. A plurality of first and second flat yarns, and a plurality of the first flat yarns and a plurality of the second flat yarns are bonded so as to cross each other, the protective layer, The intermediate layer and the gas barrier layer are joined by an adhesive.

  In a specific aspect of the optical resin sheet according to the present invention, the plurality of first flat yarns extend in parallel, the plurality of second flat yarns are parallel, and the plurality It extends in a direction perpendicular to the first flat yarn of the book.

  In another specific aspect of the optical resin sheet according to the present invention, a plurality of third sheets made of a synthetic resin film and bonded to cross the plurality of first and second flat yarns. A flat yarn; the plurality of first flat yarns extending in parallel; the plurality of second flat yarns extending in a parallel direction; and the plurality of first flat yarns extending. Extending in a direction different from the direction in which the plurality of third flat yarns are parallel to each other, and the direction in which the plurality of first flat yarns extend and the plurality of second flat yarns. The flat yarn extends in a direction different from the direction in which the flat yarn extends.

  In still another specific aspect of the optical resin sheet according to the present invention, each of the first and second flat yarns is made of a uniaxially stretched synthetic resin film.

  In still another specific aspect of the optical resin sheet according to the present invention, each of the first and second flat yarns is made of a uniaxially stretched polyolefin film.

  In another specific aspect of the optical resin sheet according to the present invention, each of the third flat yarns is made of a uniaxially stretched resin film.

  In still another specific aspect of the optical resin sheet according to the present invention, each of the third flat yarns is made of a uniaxially stretched polyolefin film.

  In still another specific aspect of the optical resin sheet according to the present invention, the optical resin sheet is used as a solar cell resin sheet.

  In still another specific aspect of the optical resin sheet according to the present invention, the optical resin sheet is used as a resin sheet for optical devices.

  ADVANTAGE OF THE INVENTION According to this invention, the optical resin sheet which cannot be curled easily can be provided.

It is front sectional drawing of the optical resin sheet which concerns on the 1st Embodiment of this invention. It is front sectional drawing of the optical resin sheet of the modification of this invention. It is a top view of the intermediate | middle layer in the 1st Embodiment of this invention. It is a top view of the intermediate | middle layer in the 2nd Embodiment of this invention.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

  FIG. 1 is a front sectional view of an optical resin sheet according to the first embodiment of the present invention.

  The optical resin sheet 1 is a laminate in which a protective film 2 as a protective layer, an intermediate layer 3 and a gas barrier film 4 as a gas barrier layer are laminated in order. The protective film 2 and the intermediate layer 3 are bonded by an adhesive 5, and the intermediate layer 3 and the gas barrier film 4 are bonded by an adhesive 5.

  The protective film 2 is a laminated body in which the first to third layers 2a to 2c are laminated in order. The first layer 2a is made of PVDF (polyvinylidene fluoride) resin. It corresponds to the outer layer in the protective film 2. Thereby, abrasion resistance and weather resistance can be improved. The first layer 2a may be a fluorine-based resin other than PVDF.

  The second layer 2b is made of a resin in which PVDF and PMMA (polymethyl methacrylate) are mixed. In this embodiment, the weight ratio of PVDF to PMMA is 6: 4.

  The weight ratio of PVDF to PMMA is not limited to the above. It is sufficient that the affinity for both the first layer 2a and the third layer 2c is enhanced.

  The third layer 2c is made of PMMA resin. Since the second layer 2b is made of a resin in which PVDF and PMMA are mixed, the affinity of the second layer 2b to both the third layer 2c made of PMMA resin and the first layer 2a made of PVDF resin. The nature is high.

  Note that the third layer 2c may be made of a resin other than PMMA. The composition of the second layer 2b is not particularly limited as long as the affinity with the first layer 2a and the third layer 2c can be increased.

  In the present embodiment, the ratio of the first layer 2a, the second layer 2b, and the third layer 2c is 3: 1: 5. Note that the ratio of the first layer 2a, the second layer 2b, and the third layer 2c is not limited to the above.

  In addition, like the modification shown in FIG. 2, the protective film 22 may be comprised only by the single layer which consists of a fluorine resin. The protective film 22 may be made of ETFE (tetrafluoroethylene and ethylene copolymer), for example. However, the PVDF used in the first embodiment has a larger difference between the melting point and the thermal decomposition temperature than ETFE. Therefore, the protective film can be formed more easily.

  Returning to FIG. 1, an intermediate layer 3 described later is laminated on the third layer 2 c of the protective film 2. A gas barrier film 4 is laminated on the intermediate layer 3. The gas barrier film 4 has the 1st-3rd layers 4a-4c laminated | stacked. The first layer 4a is made of PET (polyethylene terephthalate) resin.

  The second layer 4b is laminated on the first layer 4a and is made of a polyurethane resin. The second layer 4b is a surface layer for forming an inorganic film.

  The third layer 4c is an inorganic film laminated on the second layer 4b. More specifically, the third layer 4c is made of silicon oxide. Thereby, transparency and waterproofness can be enhanced. The third layer 4c may be made of an inorganic film having transparency and waterproofness such as alumina other than silicon oxide.

  FIG. 3 is a plan view of the intermediate layer in the first embodiment of the present invention.

  The intermediate layer 3 has a plurality of first and second flat yarns 3a and 3b. Each of the first and second flat yarns 3a and 3b is made of a uniaxially stretched synthetic resin film. More specifically, each of the first and second flat yarns 3a and 3b of the present embodiment is made of a uniaxially stretched polyolefin film. For example, the first and second flat yarns 3a and 3b are made of a uniaxially stretched PE (polyethylene) resin film or PP (polypropylene) resin film.

  The first and second flat yarns may be biaxially stretched synthetic resin films. Alternatively, the first and second flat yarns may be unstretched synthetic resin films.

  The plurality of first flat yarns 3a and the plurality of second flat yarns 3b are bonded to cross each other. More specifically, the plurality of first flat yarns 3a extend in parallel. The plurality of second flat yarns 3b are parallel to each other and extend in a direction orthogonal to the direction in which each first flat yarn 3a extends. That is, the plurality of first flat yarns 3a and the plurality of second flat yarns 3b cross each other so as to have two axes. The plurality of first flat yarns 3a and the plurality of second flat yarns 3b are bonded together by an adhesive such as a hot melt adhesive.

  The plurality of first flat yarns 3a and the plurality of second flat yarns 3b may have a fusion layer on the surface. Thereby, a plurality of flat yarns 3a can be bonded together by thermal bonding. For this reason, a plurality of flat yarns 3a can be bonded without using an adhesive.

  The intermediate layer 3 has a plurality of openings 3d. The plurality of openings 3d are arranged in a lattice shape.

  Returning to FIG. 1, the protective film 2 and the intermediate layer 3 are bonded by the adhesive 5, and the intermediate layer 3 and the gas barrier film 4 are also bonded by the adhesive 5. The adhesive 5 is made of an acrylic resin. Thereby, transparency and weather resistance can be improved.

  The protective film 2 and the gas barrier film 4 may be bonded to the intermediate layer 3 with different adhesives. However, the intermediate layer 3 has a plurality of openings 3d shown in FIG. The adhesive that joins the protective film 2 and the gas barrier film 4 to the intermediate layer 3 is partially in contact through the opening 3d. Therefore, it is preferable that the protective film 2 and the gas barrier film 4 are joined to the intermediate layer 3 with the same kind of adhesive as in this embodiment.

  By the way, the adhesive which consists of urethane type resin can also be mentioned as an adhesive agent which can improve transparency and a weather resistance. An isocyanate curing agent is added to an adhesive made of a urethane resin for curing. The isocyanate curing agent generates carbon dioxide when the adhesive made of urethane resin is cured. For this reason, carbon dioxide gas stays between the layers of the optical resin sheet, which may cause poor appearance.

  On the other hand, the adhesive 5 of this embodiment consists of acrylic resin. Therefore, the adhesive 5 can be cured by adding a smaller amount of an isocyanate curing agent than an adhesive made of urethane resin. Therefore, the amount of carbon dioxide generated during curing can be reduced. Accordingly, the size of carbon dioxide gas bubbles can be sufficiently reduced, and the incidence of appearance defects can be effectively reduced.

  The feature of this embodiment is that the protective film 2 and the gas barrier film 4 are laminated via the intermediate layer 3. Thereby, curling of the optical resin sheet 1 can be made difficult to occur. Therefore, it is possible to make it difficult to peel the optical resin sheet 1 from a flexible electronic component such as a flexible solar cell. This will be described below.

  For example, when a conventional optical resin sheet, a flexible solar cell, a sealant, and a back sheet are laminated to form a solar cell module, a thermal history is applied. Since the optical resin sheet, the flexible solar cell, the sealant, and the back sheet have different coefficients of thermal expansion, residual stress is generated by application of thermal history. Due to this residual stress, the solar cell module may be curled. Therefore, the solar cell module may be damaged. Since the optical resin sheet is also a laminate and the thermal expansion coefficient of each layer is different, residual stress is generated by the application of the thermal history. As a result, the optical resin sheet may be curled and peeled off from the flexible solar cell.

  On the other hand, the optical resin sheet 1 of the present embodiment has an intermediate layer 3 positioned between the protective film 2 and the gas barrier film 4. Since the plurality of first and second flat yarns 3a and 3b of the intermediate layer 3 are already uniaxially stretched, they are difficult to curl. Therefore, curling can be effectively suppressed. In addition, the same effect can be acquired also in the case of the synthetic resin film by which the 1st, 2nd flat yarn was biaxially stretched.

  Further, the plurality of first flat yarns 3a extend in parallel. Thereby, for example, by matching the direction in which the first flat yarn 3a extends with the direction in which the first flat yarn 3a extends easily, curling can be effectively suppressed.

  The plurality of second flat yarns 3b are parallel to each other and extend in a direction orthogonal to the direction in which the plurality of first flat yarns 3a extends. Therefore, curling due to residual stress acting in a direction different from the curling direction suppressed by the plurality of first flat yarns 3a can be effectively suppressed.

  In the intermediate layer 3 of the present embodiment, the plurality of first flat yarns 3a and the plurality of second flat yarns 3b are orthogonal to each other and do not have a complicated structure. Therefore, the direction in which curling is suppressed can be easily controlled.

  In the present embodiment, the plurality of first flat yarns 3a and the plurality of second flat yarns 3b are orthogonal to each other, but the plurality of first flat yarns 3a and the plurality of second flat yarns 3b are orthogonal to each other. It suffices if the flat yarn 3b extends in a different direction.

  When the total area of the plurality of openings 3d with respect to the area of the intermediate layer 3 is defined as the aperture ratio, the aperture ratio is preferably 20% or more and 80% or less. If the aperture ratio is 20% or more, an extreme decrease in transmittance can be suppressed. If the aperture ratio is 80% or less, curling can be effectively suppressed. In addition, it is preferable that the fall of the transmittance | permeability of the optical resin sheet 1 by passing through the intermediate | middle layer 3 is less than 5%.

  FIG. 4 is a plan view of an intermediate layer according to the second embodiment of the present invention.

  The intermediate layer 13 includes a plurality of third flat yarns 13c in addition to the plurality of first and second flat yarns 13a and 13b. Each third flat yarn 13c is made of a uniaxially stretched synthetic resin film. More specifically, each 3rd flat yarn 13c of this embodiment consists of a uniaxially stretched polyolefin film like each 1st, 2nd flat yarn 13a, 13b. For example, the third flat yarn 13c is made of a uniaxially stretched PE resin film or PP resin film.

  The first to third flat yarns may be biaxially stretched synthetic resin films. Alternatively, the first to third flat yarns may be unstretched synthetic resin films.

  The plurality of third flat yarns 13c are parallel to each other and extend in a direction different from the direction in which the plurality of first and second flat yarns 13a and 13b extend.

  In the present embodiment, the plurality of first flat yarns 13a and the plurality of second flat yarns 13b cross each other so that the angle A is 60 °. The plurality of third flat yarns 13c extend so as to connect the intersections of the plurality of first and second flat yarns 13a and 13b. The plurality of third flat yarns 13c intersect with the plurality of first and second flat yarns 13a and 13b so that the angle B is 60 °.

  The plurality of first flat yarns 13a, the plurality of second flat yarns 13b, and the plurality of third flat yarns 13c are crossed so as to have three axes. Therefore, curl can be effectively suppressed in directions in the vicinity of the three directions in which the plurality of first to third flat yarns 13a to 13c extend. Therefore, curling at more angles can be effectively suppressed.

  In the present embodiment, the angle A and the angle B are 60 °, but the angle A and the angle B are not limited to this.

  In the first embodiment, a plurality of first and second flat yarns 3a, 3b intersect so as to have two axes, and in the second embodiment, a plurality of first to first axes have three axes. The third flat yarns 13a to 13c cross each other. The plurality of flat yarns may be crossed so as to have four or more axes.

  The optical resin sheet in the present invention can be used for flexible optical devices such as flexible solar cells and organic EL.

Example 1
(Production of adhesive)
0.0245 weight of isocyanate curing agent (trade name “Coronate L-55E” manufactured by Nippon Polyurethane Industry Co., Ltd.) with respect to 100 parts by weight of the main material acrylic polymer (trade name “HT-6537AMM” manufactured by Shinseng Industries Co., Ltd.) Part, 0.5 part by weight of a silane coupling agent (manufactured by Toray Dow Corning, trade name “OFS6040”), 0.38 part by weight of an ultraviolet absorber (trade name “Adeka Stub LA36”, manufactured by Adeka) and toluene 5 as a solvent Part by weight was mixed. Thereby, an adhesive was prepared.

(Preparation of protective film)
The weight ratio of PVDF (polyvinylidene fluoride) resin (Arkema, trade name “Kynar 740”) and PMMA (polymethyl methacrylate) resin (Asahi Kasei Chemicals, trade name “Delpet SR8350”) is 6: 4. To obtain a mixed resin.

  Next, from the first layer made of PVDF resin (trade name “Kynar 740” manufactured by Arkema Co., Ltd.), the second layer made of the above mixed resin, and PMMA resin (trade name “Delpet SR8350” made by Asahi Kasei Chemicals) A laminate in which the third layers were sequentially laminated was produced by a T-die coextrusion molding method. The thickness ratio of the first layer, the second layer, and the third layer was 3: 1: 5. The total thickness of the first to third layers is 90 μm.

  Next, the surface of the third layer was subjected to corona treatment. Thus, a 90 μm-thick protective film having the first to third layers was obtained.

(Production of gas barrier film)
A polyurethane resin (manufactured by Mitsui Chemicals, trade name “Olestar RA6800”) was applied to the anchor coat surface of the first layer made of PET (polyethylene terephthalate) (trade name “Q1A15”, manufactured by Toyobo Co., Ltd.). Next, a polyurethane resin (trade name “Orestar RA6800”, manufactured by Mitsui Chemicals, Inc.) coated on PET (trade name “Q1A15” manufactured by Toyobo Co., Ltd.) is UV-cured to form a second surface film for sputtering. Layer was obtained. Thereby, a PET film having the first and second layers was obtained.

  Next, a silicon oxide film was laminated on the second layer of the PET film by vacuum sputtering. This layer made of silicon oxide is the third layer. Thus, a gas barrier film having the first to third layers was obtained.

(Middle layer)
As the intermediate layer, a mesh-like sheet (manufactured by Sekisui Film Co., Ltd., trade name “TS510”) in which a plurality of flat yarns made of high-density polyethylene were bonded together was used. Specifically, the intermediate layer of the present example is an intermediate layer having a plurality of first to third flat yarns corresponding to the intermediate layer of the second embodiment. The distance between each first flat yarn is about 8 mm. The distance between each second flat yarn and the distance between each third flat yarn is also about 8 mm. In addition, the width | variety of each 1st-3rd flat yarn is 1.2 mm. The aperture ratio is 64%.

(Production of optical resin sheet)
The adhesive was coated on the release surface of a release PET film (trade name “SP3000”, manufactured by Toyo Cloth Co., Ltd.) using a gravure coater. Next, the release surface and the third layer of the protective film were bonded together.

  Next, the adhesive was applied to the release surface of a release PET film (trade name “SP3000”, manufactured by Toyo Cloth Co., Ltd.) using a gravure coater. Next, the release surface and the third layer of the gas barrier film were bonded together.

  Next, the release PET film bonded to the protective film was peeled off to expose the adhesive. Similarly, the release PET film bonded to the gas barrier film was peeled off to expose the adhesive. The protective film, the intermediate layer, and the gas barrier film were laminated in order and bonded so that the surface of the protective film coated with the adhesive and the surface of the gas barrier film coated with the adhesive were facing each other. . Thus, an optical resin sheet was obtained.

(Example 2)
Optical resin sheet as in Example 1 except that a mesh sheet (trade name “TS705PP”, manufactured by Sekisui Film Co., Ltd.) in which a plurality of flat yarns made of high-density polyethylene are bonded as an intermediate layer was used. Was made. The intermediate layer of the present example is an intermediate layer having a plurality of first to third flat yarns, which corresponds to the intermediate layer of the second embodiment. The distance between each first flat yarn is about 3 mm. The distance between each second flat yarn and the distance between each third flat yarn is also about 3 mm. In addition, the width | variety of each 1st-3rd flat yarn is 1.2 mm. The aperture ratio is 28%.

Example 3
An optical resin sheet as in Example 1 except that a net-like sheet (manufactured by Sekisui Film Co., Ltd., trade name “HN33”) in which a plurality of flat yarns made of high-density polyethylene are bonded is used as the intermediate layer. Was made. The intermediate layer of this example is an intermediate layer having a plurality of first and second flat yarns, corresponding to the intermediate layer of the first embodiment. The distance between each first flat yarn is about 7 mm. The distance between each second flat yarn is also about 7 mm. Note that the width of each of the first and second flat yarns is 1.5 mm. The aperture ratio is 68%.

Example 4
Optical resin sheet as in Example 1 except that a mesh sheet (trade name “HM33” manufactured by Sekisui Film Co., Ltd.) in which a plurality of flat yarns made of high-density polyethylene are bonded as an intermediate layer was used. Was made. The intermediate layer of this example is an intermediate layer having a plurality of first and second flat yarns, corresponding to the intermediate layer of the first embodiment. The distance between each first flat yarn is about 6 mm. The distance between each second flat yarn is also about 6 mm. Note that the width of each of the first and second flat yarns is 3 mm. The aperture ratio is 32%.

(Example 5)
An optical resin sheet was prepared in the same manner as in Example 1 except that ETFE (tetrafluoroethylene and ethylene copolymer) (trade name “Aflex 100N” manufactured by Asahi Glass Co., Ltd.) was used as the protective film. In addition, the protective film of a present Example is a single layer.

(Comparative Example 1)
An optical resin sheet was produced in the same manner as in Example 1 except that the intermediate layer was not used.

(Comparative Example 2)
An optical resin sheet was prepared in the same manner as in Comparative Example 1 except that the adhesive was applied only to the gas barrier film.

(Evaluation)
The light transmittances of the optical resin sheets of Examples 1 to 5 and Comparative Examples 1 and 2 were measured according to JIS K7105. In measuring the light transmittance, a haze meter manufactured by Toyo Seiki Co., Ltd. was used.

  The curls of the optical resin sheets of Examples 1 to 5 and Comparative Examples 1 and 2 were measured. When measuring the curl, a 30 cm × 30 cm test piece of the optical resin sheet was cut out. Next, the test piece was left on a flat inspection table. Next, the height from the portion where the test piece was in contact with the inspection table to the end portion of the test piece floating by curling was measured. Next, the test piece was heated at 80 ° C. for 5 minutes. Next, after cooling a test piece to normal temperature, the said height of the test piece was measured again.

  Table 1 below shows the results of the evaluation.

  In Comparative Examples 1 and 2, since the test piece curled and the end of the test piece came into contact with the test piece, the height due to curling could not be measured. On the other hand, in Examples 1-5, the said height can be suppressed within 3 mm after a heating. Therefore, it can be seen that curling can be effectively suppressed by having the intermediate layer.

  Further, in Comparative Examples 1 and 2, the light transmittance was 89%, whereas in Examples 1 and 3, it was 88%, and in Example 4, it was 87%. Thus, it can be seen that the light transmittance is not substantially lowered. In Example 5, similar to Comparative Examples 1 and 2, the light transmittance was 89%. In Example 2 in which the aperture ratio of the intermediate layer was the lowest in Examples 1 to 5, the light transmittance was 84%. Therefore, also in Example 2, the fall from the light transmittance of Comparative Examples 1 and 2 can be kept at 5%. Thus, it can be seen that even when the protective film and the gas barrier film are bonded via the intermediate layer, the light transmittance can be reduced within 5%.

DESCRIPTION OF SYMBOLS 1 ... Optical resin sheet 2 ... Protective film 2a ... 1st layer 2b ... 2nd layer 2c ... 3rd layer 3 ... Intermediate | middle layer 3a, 3b ... 1st, 2nd flat yarn 3d ... Opening 4 ... Gas barrier film 4a ... first layer 4b ... second layer 4c ... third layer 5 ... adhesive 13 ... intermediate layers 13a-13c ... first to third flat yarns 22 ... protective film

Claims (9)

A protective layer;
An intermediate layer laminated on the protective layer;
A gas barrier layer laminated on the intermediate layer,
The intermediate layer has a plurality of first and second flat yarns made of a synthetic resin film, and the plurality of first flat yarns and the plurality of second flat yarns cross each other. Pasted together,
An optical resin sheet in which the protective layer, the intermediate layer, and the gas barrier layer are bonded together with an adhesive.   The plurality of first flat yarns extend in parallel, and the plurality of second flat yarns extend in a direction parallel to the plurality of first flat yarns. The optical resin sheet according to claim 1. A plurality of third flat yarns made of a synthetic resin film and bonded to cross the plurality of first and second flat yarns;
The plurality of first flat yarns extend in parallel, the plurality of second flat yarns are parallel to each other, and are different from the direction in which the plurality of first flat yarns extend. The plurality of third flat yarns are parallel to each other, and the direction in which the plurality of first flat yarns extend and the plurality of second flat yarns extend. The optical resin sheet according to claim 1, wherein the optical resin sheet extends in a direction different from any of the directions.   The optical resin sheet according to any one of claims 1 to 3, wherein each of the first and second flat yarns comprises a uniaxially stretched synthetic resin film.   The optical resin sheet according to claim 4, wherein each of the first and second flat yarns is made of a uniaxially stretched polyolefin film.   The optical resin sheet according to any one of claims 3 to 5, wherein each of the third flat yarns is made of a uniaxially stretched resin film.   The optical resin sheet according to claim 6, wherein each of the third flat yarns is made of a uniaxially stretched polyolefin film.   The optical resin sheet according to any one of claims 1 to 7, which is a solar cell resin sheet.   The optical resin sheet according to any one of claims 1 to 7, which is a resin sheet for optical devices.

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