Edge sealing structure of light control film

Abstract

To provide an end sealing structure of a dimming film, which eliminates deterioration of sealing performance even without using various kinds of sealing tapes with different thicknesses of adhesive material layers.SOLUTION: An end sealing structure 10-1 of a dimming film that seals an end cross section 11-1 of a dimming film 3-1 arranged on a transparent substrate 4 with a sealing tape 9, comprises a step absorption part 6-1 that reduces a step formed at the end of the dimming film by arranging the dimming film on the transparent substrate, and the sealing tape 9 affixed across the surface of the dimming film and the step absorption part via an adhesive material layer 2-1. The step absorption part fills a space surrounded by the end cross section, the sealing tape and the transparent substrate, which is formed when the end cross section of the dimming film is sealed with the sealing tape.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an end sealing structure of a light control film in a light control module. [Background technology]

[0002] The light control film is a laminate in which a liquid crystal light control layer is laminated on a transparent conductive film, with the transparent conductive film side of the transparent conductive film facing inward. A light control module is produced by using such a light control film and disposing the light control film on a transparent substrate.

[0003] Since the light control film is cut to fit the size of the transparent substrate, a sealing layer is formed on the end cross section of the light control film to prevent moisture and other substances from entering the liquid crystal light control layer from the end cross section.

[0004] Known methods for forming a sealing layer include applying a resin material (sealing resin) that is difficult for moisture and oxygen to pass through to the cross section of the light-control film (e.g., Patent Document 1), and covering the cross section with sealing resin and tape (e.g., Patent Document 2).

[0005] When sealing the end cross section of the light control film of the light control module using a sealing tape, the sealing performance is deteriorated due to the step formed between the transparent substrate as the base and the end of the light control film placed on it. If the step is small, the deterioration of the sealing performance is small, but if the step is large, the impact on the sealing performance becomes greater.

[0006] FIG. 4(a) shows an example in which a relatively thin light control film 3-1 is disposed on a transparent substrate 4. A step corresponding to the thickness of the light control film 3-1 is formed in the sealing portion 8-1 at the end of the light control film 3-1. In the case of a thin light control film 3-1, the space 5-1 formed in the sealing portion 8-1 is small, and adverse effects such as deterioration of sealing performance are small. The sealing tape 9-1 used for sealing is a tape base material 1 on which an adhesive layer 2-1 is formed.

[0007] Figure 4(b) illustrates the case of a light control film 3-2 that is thicker than the light control film 3-1. The same sealing tape 9-1 as in Figure 4(a) is used as the sealing tape. In this case, the step becomes larger, so the space 5-2 formed in the sealing portion 8-2 becomes larger than the space 5-1. Therefore, the deterioration of the sealing performance becomes greater.

[0008] In order to suppress the deterioration of sealing performance due to the increase in the step, a sealing tape 9-2 using an adhesive layer 2-2 thicker than the adhesive layer 2-1 may be used as shown in Fig. 4(c). By making the adhesive layer thicker, the space 5-3 can be made smaller than the space 5-2 when the adhesive layer is thin, and the adverse effect on the sealing performance can be suppressed.

[0009] In addition, it is expected that new layers will be added to the light control film to add new functions. Therefore, it is expected that the light control film will become thicker. In response to such a trend, it is possible to prepare various types of sealing tapes with different thicknesses of the adhesive layer. However, preparing various types of components is not preferable because it leads to increased manufacturing costs. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2019-159139 A [Patent Document 2] JP 2019-28387 A Summary of the Invention [Problem to be solved by the invention]

[0011] In view of the above circumstances, the present invention aims to provide an end sealing structure for a light-control film that does not deteriorate the sealing performance even without using a variety of sealing tapes with different adhesive layer thicknesses. [Means for solving the problem]

[0012] As a means for solving the above problems, a first aspect of the present invention is a light control film end sealing structure in which an end cross section of a light control film arranged on a transparent substrate is sealed with a sealing tape, A step absorbing portion that reduces a step formed at an end of the light control film by disposing the light control film on the transparent substrate; and a sealing tape attached across the surface of the light control film and the step absorbing portion via an adhesive layer, The step absorbing portion is an end sealing structure of a light-control film, characterized by filling the space surrounded by the end cross section, the sealing tape, and the transparent substrate, which is formed when the end cross section of the light-control film is sealed with a sealing tape.

[0013] A second aspect is an end sealing structure of a light control film according to the first aspect, characterized in that the step absorbing portion is an elastic body having a shape corresponding to the space.

[0014] In addition, a third aspect is an end sealing structure of a light-control film in which, in the first aspect, the step absorbing portion is a laminate of one layer of adhesive tape or two or more layers of adhesive tape having a thickness equivalent to that of the light-control film and closely attached to the end cross section of the light-control film at the step.

[0015] In the fourth aspect, the thickness of the step absorbing portion closest to the end cross section is equal to or less than the thickness of the light control film, and is equal to or greater than the thickness of the side closest to the end cross section; This is an end sealing structure of a light-controlling film described in any of the first to third aspects, characterized in that the length of the step absorbing portion from the side closest to the end cross section to the side closest to the end cross section is 1 mm to 100 mm.

[0016] Further, a fifth aspect is an end sealing structure of a light-controlling film described in the first aspect, characterized in that the step absorption portion is formed when the end cross section of the light-controlling film is sealed with the sealing tape, and is composed of a sphere or ellipsoid, or an elastic body having a shape obtained by deforming either of these, which is provided in contact with the end cross section, the sealing tape, and the transparent substrate in the space surrounded by the end cross section, the sealing tape, and the transparent substrate.

[0017] In addition, in the sixth aspect, the thickness of the thickest part of the step absorbing part is equal to or less than the thickness of the light control film, The end sealing structure of the light control film according to the fifth aspect is characterized in that the length from the end of the step absorbing portion on the end cross section side to the end opposite the end cross section is 1 mm to 100 mm. Effect of the Invention

[0018] The end sealing structure of the light control film of the present invention is a light control film end sealing structure in which the end cross section of the light control film arranged on a transparent substrate is sealed with a sealing tape. The end sealing structure of the light control film includes a step absorbing part that reduces a step formed at the end of the light control film by arranging the light control film on the transparent substrate, and a sealing tape attached across the surface of the light control film and the step absorbing part. The step absorbing part is attached in close contact with the end cross section of the light control film at the step, and further includes a layer of adhesive tape or is a laminate in which two or more layers of adhesive tape are laminated. Therefore, the step formed at the edge of the light control film placed on the transparent substrate is eliminated by the step absorbing part. By attaching a sealing tape on the light control film with the step eliminated and the step absorbing part, it is possible to reduce or eliminate the adverse effect on sealing performance caused by the space formed in the step part.

[0019] In addition, the step absorbing part does not need to be limited to a laminate. When a sealing tape is applied across the upper surface of the light control film and the transparent substrate at the end of the light control film arranged on the transparent substrate, a space is formed surrounded by the end cross section of the light control film, the sealing tape, and the transparent substrate. By absorbing the step by arranging or inserting a step absorbing part made of an elastic body having a shape that fills the space in the space, the adverse effect on the sealing performance can be mitigated or eliminated. [Brief description of the drawings]

[0020] [Figure 1] 3A and 3B are cross-sectional views illustrating examples of the cross-sectional structure of the end sealing structure of the light control film of the present invention. [Diagram 2] 3A and 3B are cross-sectional views illustrating examples of the cross-sectional structure of the end sealing structure of the light control film of the present invention. [Diagram 3] 3 is a cross-sectional explanatory diagram illustrating the form of a step absorbing portion in the cross-sectional structure of the end sealing structure of the light control film in FIG. 2. [Figure 4] FIG. 13 is a cross-sectional view illustrating an example of a cross-sectional structure of an end sealing structure of a conventional light control film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] <First embodiment> A first embodiment of the end sealing structure of the light control film of the present invention will be described with reference to FIG.

[0022] The end sealing structure of the light control film in the first embodiment of the present invention is a light control film end sealing structure in which the end cross section 11-1 of the light control film 3-1 arranged on the transparent substrate 4 is sealed with a sealing tape 9 (see Figure 1(a)).

[0023] By disposing the light control film 3-1 on the transparent substrate 4, a step is formed at the end of the light control film 3-1. By attaching a step absorbing part 6-1 having a thickness equivalent to the step, the step can be reduced or eliminated. After the step is reduced or eliminated, a sealing tape 9 having an adhesive layer 2-1 on a tape base material 1 is attached across the surface of the light control film 3-1 and the step absorbing part 6-1 to form the light control film end sealing structure 10-1 of the present invention.

[0024] The step absorbing part 6-1 is attached in close contact with the end cross section 11-1 of the light control film 3-1 at the step. The step absorbing part 6-1 has a thickness equivalent to that of the light control film 3-1, and the step absorbing part 6-1 may be made of one layer of adhesive tape or may be a laminate obtained by laminating two or more layers of adhesive tape.

[0025] For example, even if the step absorbing part 6-1 has only one type of thickness, it can be accommodated with one type of thickness of adhesive tape by laminating two or more layers to form a laminate. For example, even if the height of the step is twice as high, the step can be eliminated or mitigated by forming the step absorbing part 6-2 as a laminate of two layers of adhesive tape as shown in Fig. 1(b). The number of layers of the step absorbing part 6-2 constituting the laminate can be three or more.

[0026] <Second embodiment> Next, a second embodiment of the end sealing structure of the light control film of the present invention will be described with reference to FIGS.

[0027] A second embodiment of the light control film end sealing structure of the present invention is a light control film end sealing structure 10-3 in which an end cross section 11-2 of a light control film 3-2 arranged on a transparent substrate 4 is sealed with a sealing tape 9.

[0028] By disposing the light control film 3-2 on the transparent substrate 4, a step is formed at the end of the light control film 3-2. The light control film end sealing structure 10-3 of the present invention includes a step absorbing part 7-1 that reduces the formed step, and a sealing tape 9 that is attached across the surface of the light control film 3-2 and the step absorbing part 7-1 via an adhesive layer 2-1. The step absorbing part 7-1 has a different shape from the step absorbing parts 6-1 and 6-2 in the first embodiment.

[0029] The step absorbing portion 7-1 is formed from an elastic body having a shape capable of filling the space formed when the end cross section 11-2 of the light control film 3-2 is sealed with the sealing tape 9. The space is formed by being surrounded by the end cross section 11-2, the sealing tape 9, and the transparent substrate 4. It does not have to be exactly the same as the three-dimensional shape of the space. This is because the step absorbing portion 7-1 of the present invention is made of an elastic body. Because it is made of an elastic body, fine adjustments can be made.

[0030] An elastic body is an object that, like rubber, deforms in the direction of the applied force when a force is applied, and returns to its original shape when the force is removed. In general, solids have elasticity, but an object that can return to its original shape over a wide range, even if it is greatly deformed, is called an elastic body. Elastic bodies include polymeric materials (also called elastomers) that have elasticity. For example, natural rubber, styrene butadiene rubber, chloroprene rubber, acrylonitrile rubber, butyl rubber, ethylene propylene rubber, urethane rubber, silicone rubber, and other rubbers can be listed. Elastomers can be divided into thermosetting elastomers that do not soften even when heated, and thermoplastic elastomers that become fluid when heated but regain their rubbery properties when cooled. Examples of thermosetting elastomers include some urethane rubbers, silicone rubbers, and fluororubbers. Examples of thermoplastic elastomers include polystyrene-based, polyolefin / alkene-based, polyvinyl chloride-based, polyurethane-based, polyester-based, and polyimide-based.

[0031] In Fig. 2(a), when a sealing tape 9 is applied across the upper surface of the light control film 3-2 and the surface of the transparent substrate 4 at a stepped portion (step portion), a space is formed at the stepped portion. The cross-sectional shape of the space resembles a right-angled triangle.

[0032] In the cross section of the space in Fig. 2(a), a shape similar to a right triangle is formed, but by cutting the right triangle at a position close to the intersection of the hypotenuse and the longer side with a line parallel to the shorter side, a trapezoid is formed. This shows the cross-sectional shape of the step absorption part 7-1 to be placed in the space in Fig. 2(a), and Fig. 3(a) is a diagram showing the trapezoid, with the length of the lower base of the trapezoid being b, the flow of the upper base being a, and the distance between the upper base and the lower base being c.

[0033] In Figure 3(a), b is the thickness of the step absorbing section 7-1 (see Figure 2(a)), which is made to fit the shape of the space, on the side that is in close contact with the light-control film, a is the thickness on the side opposite the light-control film 3-2, c is the length of the step absorbing section 7-1 in the direction extending outward from the end cross section 11-2 of the light-control film 3-2, and d is the thickness of the light-control film.

[0034] In the present invention, it is desirable that a, b, c, and d in FIG. 0≦a≦b, 0≦b≦d, 1≦c≦100. The unit is mm (millimeters).

[0035] 0≦a≦b is a relational expression indicating that in the step absorbing portion 7-1, the film thickness b on the light control film 3-2 side is thick and becomes thinner as it moves away from the light control film 3-2. This is the shape of the space that is naturally formed at the end of the light control film 3-2 when the sealing tape 9 is attached across from the top surface of the light control film 3-2 to the surface of the transparent substrate 4, as shown in FIG. 2(a).

[0036] 0≦b≦d is a relational expression showing that the thickness b on the light control film 3-2 side is equal to or less than the thickness d of the light control film 3-2. If b exceeds d, this causes further steps, which is not preferable.

[0037] 1≦c≦100 is a relational expression indicating that the length of the step absorbing portion 7-1 extending outward from the end cross section 11-2 of the light control film 3-2 is 1 mm or more and 100 mm or less. The thickness of the light control film 3-2 is approximately 0.1 mm to 0.3 mm. For example, when c is 1 mm for a light control film with a thickness of 0.1 mm, the sealing tape is attached over a length 10 times the step of 0.1 mm. When c is 100 mm, it is 1000 times the step. From the above, it corresponds to forming the step absorbing portion 7-1 over a sufficient length. This is to form a gentle slope by the step absorbing portion 7-1 that absorbs the step. This can mitigate or eliminate the adverse effect on sealing performance caused by the space formed in the step.

[0038] Furthermore, as illustrated in Figure 2(b), the step absorption portion 7-2 may be composed of an elastic body having a sphere, ellipsoid, or a deformed shape thereof, which is provided in contact with the end cross section 11-2, the sealing tape 9, and the transparent substrate 4 in the space formed when the end cross section 11-2 of the light control film 3-2 is sealed with the sealing tape 9.

[0039] FIG. 3(b) is an enlarged cross-sectional view of the step portion of FIG. 2(b). In Figure 3(b), d is the thickness of the light-control film, f is the thickness of the step absorbing section 7-2 (see Figure 2(b)), and e is the length of the step absorbing section 7-2 extending outward from the end cross section 11-2 of the light-control film 3-2.

[0040] It is desirable that d, e, and f satisfy the following relationship. 1≦e≦100, 0≦f≦d. The unit is mm (millimeters).

[0041] 1≦e≦100 is a relational expression indicating that the length of the step absorbing portion 7-2 extending outward from the end cross section 11-2 of the light control film 3-2 is 1 mm or more and 100 mm or less. The thickness of the light control film 3-2 is approximately 0.1 mm to 0.3 mm. For example, when e is 1 mm for a light control film with a thickness of 0.1 mm, the sealing tape is attached over a length 10 times the step of 0.1 mm. When e is 100 mm, it is 1000 times the step. From the above, it corresponds to forming the step absorbing portion 7-2 over a sufficient length. This is to form a gentle slope by the step absorbing portion 7-2 that absorbs the step. This can mitigate or eliminate the adverse effect on sealing performance caused by the space formed in the step.

[0042] 0≦f≦d is a relational expression showing that the thickness f of the step absorbing part 7-2 is equal to or less than the film thickness d of the light control film 3-2. If f exceeds d, this causes further steps, which is not preferable.

[0043] (Transparent substrate) The transparent substrate 4 is not particularly limited, but may be any substrate that has a visible light transmittance of 80% or more and is made of a colorless material. For example, a glass substrate or a transparent resin substrate may be preferably used.

[0044] (Light control film) The light control films 3-1 and 3-2 are not particularly limited as long as they are members capable of controlling the transmission / non-transmission of light. For example, a light control film made of a laminate in which two conventionally used transparent conductive films are placed with their transparent conductive film sides facing each other and a liquid crystal light control layer is sandwiched between them can be suitably used. Instead of a film, a transparent conductive sheet in which a transparent conductive film is formed on the surface of a sheet-like resin substrate or a transparent conductive glass substrate in which a transparent conductive film is formed on a glass substrate may be used.

[0045] (Sealing tape) The sealing tape 9 may be an adhesive tape having an adhesive layer 2-1 on a tape substrate 1. There is no need to limit the material of the tape substrate 1 as long as it does not have high water permeability or water vapor permeability. Examples of the material include polyvinyl alcohol, ethylene (30)-vinyl alcohol (70) copolymer, polyacrylonitrile, polyvinylidene chloride, polyethylene terephthalate, iron 6, polyvinyl chloride, polylactic acid, high density polyethylene, polypropylene, and low density polyethylene. The adhesive layer 2-1 is not particularly limited as long as it is made of a material having adhesive properties, and examples of the material include acrylic adhesives, urethane adhesives, and silicone adhesives.

[0046] (Step absorption section) The step absorbing parts 6-1 and 6-2 have the form of an adhesive tape. As the base material of the adhesive tape, the same material as that of the sealing tape may be used from the viewpoint of preventing the intrusion of moisture and water vapor, as with the sealing tape. As the adhesive layer of the adhesive tape, the same material as that of the sealing tape may be used.

[0047] The step absorbing portions 7-1 and 7-2 are formed of a molded elastic body. For example, as shown in Fig. 2(a), the step absorbing part 7-1 must have a shape that can fill the space formed in the step by attaching a sealing tape 9 across the upper surface of the light control film 3-2 and the surface of the transparent substrate 4. The cross-sectional shape is similar to a right-angled triangle. As an example of such a shape, a step absorbing part 7-1 having a trapezoidal cross-sectional shape as shown in Fig. 3(a) may be used.

[0048] As shown in FIG. 2(b), the step absorbing portion 7-2 is disposed in a space formed in a step by attaching a sealing tape 9 across the upper surface of the light control film 3-2 and the surface of the transparent substrate 4. The cross-sectional shape is a sphere, an ellipsoid, or a shape obtained by modifying these. As an example of such a shape, a step absorbing portion 7-2 having an elliptical cross-sectional shape as shown in FIG. 3(b) may be used. [Explanation of symbols]

[0049] 1. Tape base material 2-1, 2-2: Adhesive layer 3-1, 3-2: Light control film 4. Transparent substrate 5-1, 5-2, 5-3...space 6-1, 6-2: Step absorption section 7-1, 7-2: Step absorption section 8-1, 8-2, 8-3: Sealing section 9, 9-1, 9-2...Sealing tape 10-1, 10-2, 10-3, 10-4...End sealing structure 11-1, 11-2...End cross section

Claims

1. A light control film end sealing structure in which an end cross section of a light control film arranged on a transparent substrate is sealed with a sealing tape, A step absorbing portion that reduces a step formed at an end of the light control film by disposing the light control film on the transparent substrate; and a sealing tape attached across the surface of the light control film and the step absorbing portion via an adhesive layer, The step absorbing portion fills a space surrounded by the end section, the sealing tape, and the transparent substrate, which is formed when the end section of the light control film is sealed with the sealing tape, The step absorbing portion is formed when the end section of the light control film is sealed with the sealing tape, and in a space surrounded by the end section, the sealing tape, and the transparent substrate, the step absorbing portion is formed of an elastic body having a shape of a sphere or ellipsoid or a deformed shape of either of them in contact with the end section, the sealing tape, and the transparent substrate. The end sealing structure of a light control film is characterized in that

2. The thickness of the thickest part of the step absorbing part is equal to or less than the thickness of the light control film, The end sealing structure of the light control film according to claim 1, characterized in that the length from the end of the step absorbing portion on the end cross section side to the end opposite the end cross section is 1 mm to 100 mm.

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