JP2018091986A - Light control film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light control film having a performance (curve surface pasting property) allowing the film to be satisfactorily pasted to a substrate having a curve surface, and also having an in-combustibility that is a combustibility lower than a fire retardancy.SOLUTION: The light control film includes a liquid-crystal light control layer, and a transparent conductive film and transparent organic film disposed on the opposite surfaces of the liquid crystal light control layer, in this sequence. In the light control film, a transparent incombustible film is bonded via a transparent adhesive layer to the transparent organic film disposed on at least one surface, and the thickness of the transparent incombustible film is 200 μm or less. Alternately, a transparent incombustible film is disposed on the transparent organic film on at least one surface, and the thickness of the transparent incombustible film is 200 μm or less.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a light control film that is used for a window glass of a building or a transportation system, includes a light control layer using liquid crystal, and can switch between a transparent state and an opaque state.

  Windows with a dimming function that can be switched between a transparent state and an opaque state by voltage control have been evaluated for their design and concealment properties, and are becoming increasingly popular in buildings and transportation. For example, the Rokko Liner, one of the public transportation systems, provides a dimming function to the windows, and helps to protect the privacy of residents by switching between transparent and opaque during normal driving and driving around the house.

  Conventionally, when using in these facilities as a window with dimming function, there is a method of sandwiching a structural part (dimming layer) having a dimming function between two plate glasses and bonding them by vacuum pressure bonding, pressurization, or heating. (For example, Patent Document 1). However, since two plate glasses are used, there are problems that the weight becomes heavy, it is difficult to bond to a curved surface, and the manufacturing method is complicated.

  In recent years, in order to solve the above-described problems, there is an increasing demand for a light control film of a type that is bonded to a single substrate such as glass. By adopting the bonding type, there is an advantage that the weight can be reduced because the number of substrates is one, the construction cost can be suppressed, and further, application to existing infrastructure is possible (for example, Patent Document 2).

  On the other hand, it is required by law that interior materials such as special buildings such as hospitals and high-rise buildings are flame retardant. Similarly, interior materials such as aircraft and railways are also required to be fire retardant or non-flammable with low flammability as a fire countermeasure, but no effective investigation has been made regarding the non-flammability of conventional light control films. .

Japanese Patent Laid-Open No. 08-184273 Japanese Patent No. 5910788

General Incorporated Foundation Building Material Testing Center; Fireproof and Fireproof Performance Test / Evaluation Procedure Manual, Excerpted version of “Performance Evaluation of Fireproof Materials”

  The present invention has been made in order to solve the above-mentioned problems, and the object of the present invention is more than the ability to be bonded to a substrate having a curved surface without problems (curved surface bonding property) and flame retardancy. Furthermore, it aims at providing the light control film which has both nonflammability with low combustibility.

In order to solve the above-mentioned problem, the invention according to claim 1 includes a liquid crystal light control layer, and a transparent conductive film and a transparent organic film in this order on both sides of the liquid crystal light control layer,
A transparent non-combustible film is adhered to the transparent organic film on at least one surface via a transparent adhesive layer,
And the film thickness of the said transparent nonflammable film is 200 micrometers or less, It is set as the light control film characterized by the above-mentioned.

The invention according to claim 2 comprises a liquid crystal light control layer, and transparent conductive films on both sides of the liquid crystal light control layer,
And a transparent non-combustible film on one surface of the transparent conductive film, a transparent organic film on the other surface,
And the film thickness of the said transparent nonflammable film is 200 micrometers or less, It is set as the light control film characterized by the above-mentioned.

The invention according to claim 3 comprises a liquid crystal light control layer, a transparent conductive film, and a transparent noncombustible film in this order on both sides of the liquid crystal light control layer,
And the film thickness of the said transparent nonflammable film is 200 micrometers or less, It is set as the light control film characterized by the above-mentioned.

  Invention of Claim 4 is a laminated body in which the said transparent nonflammable film contains a glass film or a glass film layer, The light control film as described in any one of Claims 1-3 characterized by the above-mentioned It is a thing.

  According to the present invention, the liquid crystal light control layer, the transparent conductive film and the transparent organic film are provided in this order on both sides of the liquid crystal light control layer, and the transparent organic film on at least one surface is provided with a transparent noncombustible film. Is provided with a transparent non-combustible film on a light-controlling film having a thickness of 200 μm or less, or a transparent conductive film on at least one surface, and the transparent non-combustible film. Since it was set as the light control film whose film thickness of an adhesive film is 200 micrometers or less, it becomes a light control film which has both curved surface bonding property and nonflammability.

It is a schematic cross section which illustrates the structure of 1st Embodiment of the light control film of this invention. It is a schematic cross section which illustrates the structure of 2nd Embodiment of the light control film of this invention. It is a schematic cross section which illustrates the structure of 3rd Embodiment of the light control film of this invention. It is a schematic cross section which shows the basic structure of the conventional light control film.

  Hereinafter, although the light control film which concerns on embodiment of this invention is demonstrated, this invention is not limited to the following embodiment as it is, It can change and embody, unless it deviates from the meaning of this invention. Various inventions can be envisaged by appropriately combining the matters shown in the present application. In addition, the same code | symbol is attached | subjected about the same component unless there is a reason for convenience, and the overlapping description is abbreviate | omitted. Also, in the drawings used in the following description, in order to make the features easy to understand, the portions that become the features may be shown in an enlarged manner, and the dimensional ratios of the respective constituent elements are not the same as the actual ones.

  For comparison, the basic structure of a conventional light control film will be described first. FIG. 4 is a schematic cross-sectional view showing the basic structure of a conventional light control film. A conventional light control film 6 includes a liquid crystal light control layer 3 and a transparent conductive film 2 and a transparent organic film 1 in this order on both sides of the liquid crystal light control layer 3.

In the first embodiment of the light control film of the present invention, in addition to the basic structure of the conventional light control film 6, the transparent nonflammable film 4 has the transparent adhesive layer 5 on the transparent organic film 1 on at least one surface. And the film thickness of the transparent noncombustible film 4 is 200 μm or less. FIG. 1 is a schematic cross-sectional view illustrating the structure of the light control film 7 of the first embodiment of the present invention. Here, the transparent organic film 1 on one side has a film thickness of 200 μm or less. 4 is bonded via a transparent adhesive layer 5. In 1st Embodiment, you may equip the transparent organic film 1 of the surface of both sides with the transparent nonflammable film 5 and the transparent contact bonding layer 4 which are the film thickness of 200 micrometers or less similarly. Here, when it is larger than 200 μm, there is an increased risk of causing damage such as cracks or cracks when the substrate is bonded to a curved substrate.

  FIG. 2 is a schematic cross-sectional view illustrating the structure of the light control film 8 of the second embodiment of the present invention. The liquid crystal light control layer 3 includes the transparent conductive film 2 on both sides, and The transparent noncombustible film 4 is provided on one surface, the transparent organic film 1 is provided on the other surface, and the thickness of the transparent noncombustible film 4 is 200 μm or less.

  FIG. 3 is a schematic cross-sectional view illustrating the structure of the light control film 9 according to the third embodiment of the present invention. The transparent conductive film 2 is provided on the liquid crystal light control layer 3 and the surfaces on both sides of the liquid crystal light control layer 3. And the transparent noncombustible film 4 in this order, and the film thickness of the transparent noncombustible film 4 is 200 μm or less.

In the present application, the “nonflammability” of the transparent nonflammable film 4 is consistently described in Non-Patent Document 1 based on the Building Standard Law, and “nonflammability” of nonflammable materials defined by the combustion categories shown in Table 1 ”. That is, the material satisfies all the following conditions 1) to 3) at a heating time of 20 minutes.
1) The total calorific value is 8 MJ / m ² or less.
2) There should be no cracks or holes penetrating to the back side, which is harmful to disaster prevention.
3) The heat generation rate should not exceed 200 kW / m ² for 10 seconds or more.

  The visible light transmittances of the transparent organic film, the transparent conductive film, and the transparent adhesive layer in the present application are desirably 95% or more, 85% or more, and 85% or more, respectively.

  The transparent nonflammable film 4 may be any film that is nonflammable and transparent. Specific examples include glass films called so-called “glass cloth”, one kind selected from polyvinyl chloride (PVC), quartz, alumina and the like, or a laminate thereof. In particular, a laminated body including a glass film or a glass film layer is preferable.

  The transparent adhesive layer 5 is not particularly limited as long as an adhesive layer having transparency and a strong adhesive function is formed from the coating liquid. Specifically, an epoxy adhesive layer, an epoxy UV curable adhesive layer, an acrylic adhesive is used. Examples thereof include an acrylic UV curable adhesive layer, a urethane curable adhesive layer, and a silicon adhesive layer.

  The transparent organic film 1 includes polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate resin (PMMA), cycloolefin polymer (COP), triacetyl from the viewpoint of transparency, ease of handling, strength and cost. Examples include films made of cellulose (TAC), transparent polyimide (PI), and the like.

  The transparent conductive film 2 only needs to be transparent and conductive. Specifically, indium tin oxide (ITO), polystyrene sulfonate-doped polyethylene dioxythiophene (PEDOT: PSS), carbon nanotube (CNT) , Graphene, metals and metal oxides.

  The liquid crystal light control layer 3 may have any light control function that switches between transparent and opaque by controlling the applied voltage. As a method having a dimming function, for example, a polymer network liquid crystal (PNLC) method, a polymer dispersed liquid crystal (PDLC) method, a transparent film formed with an alignment film TN ( (Twisted Nematic) A method of holding a liquid crystal can be used.

  The light control film of the present invention can be applied not only to a normal mode method in which a voltage is applied from an opaque state to a transparent state but also to a reverse mode method in which a voltage is applied to change from a transparent state to an opaque state. It is.

  The thickness of the liquid crystal light control layer in the light control film of the present invention is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 25 μm or less. When the thickness of the light control layer is less than 5 μm, there is a tendency that a short circuit is likely to occur, and the lamination with the transparent conductive film tends to be difficult. When the thickness exceeds 50 μm, the responsiveness decreases.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Example 1>
As Example 1, a light control film 7 having the structure of the first embodiment shown in FIG. 1 was produced as follows.

  A transparent organic film 1 (50 μm thick PET film: Toray, trade name Lumirror) is used as the first surface side substrate (see Table 2) on the upper side in FIG. ) Was formed by sputtering, and a liquid crystal light control layer 3 having a thickness of 30 μm was formed on the surface of the transparent conductive film 2. Next, a transparent conductive film 2 on the second surface side (ITO having a thickness of 150 nm) is formed on the surface of the liquid crystal light control layer 3 by the same method, and the transparent organic film 1 (thickness) is further used as the second surface side substrate. A 50 μm PET film (product name: Lumirror, manufactured by Toray Industries, Inc.) was bonded to produce a light control film 6 having a conventional basic structure. Next, a glass film having a thickness of 200 μm (manufactured by Nippon Electric Glass Co., Ltd., trade name G-leaf) is used as a transparent incombustible film 4 on one side of the light control film 6 having the conventional basic structure, and an adhesive material as the transparent adhesive layer 5. The light control film 7 of 1st Embodiment which laminated together through the (Daikin epoxy-type adhesive agent, brand name UV1000), and was laminated | stacked with the glass film of thickness 200 micrometers shown in FIG. 1 was produced.

<Example 2>
As Example 2, a light control film 8 having the structure of the second embodiment shown in FIG. 2 was produced as follows.

  The transparent noncombustible film 4 (glass film having a thickness of 200 μm: product name G-leaf made by Nippon Electric Glass Co., Ltd.) is used as the second surface side base material which is the lower side in FIG. ITO) was formed by sputtering, and a liquid crystal light control layer 3 having a thickness of 30 μm was formed on the surface of the transparent conductive film 2. Next, a transparent conductive film 2 on the first surface side (ITO having a thickness of 150 nm) is formed on the surface of the liquid crystal light control layer 3 by the same method, and the transparent organic film 1 (thickness) is further used as the first surface side substrate. A 50 μm PET film (product name: Lumirror, manufactured by Toray Industries, Inc.) was bonded to produce a light control film 8 of the second embodiment shown in FIG.

<Example 3>
As Example 3, a light control film 9 having the structure of the third embodiment shown in FIG. 3 was produced as follows.

  A transparent conductive film 2 (ITO with a thickness of 150 nm) is formed on one side of the transparent noncombustible film 4 (Glass film with a thickness of 100 μm: trade name G-leaf manufactured by Nippon Electric Glass, Inc.) by sputtering. The liquid crystal light control layer 3 was formed with a thickness of 30 μm on the surface of the transparent conductive film 2. Next, a transparent conductive film 2 (ITO having a thickness of 150 nm) on the first surface side is formed on the surface of the liquid crystal light control layer 3 by the same method, and a transparent noncombustible film 4 (as a first surface side substrate) is further formed. A glass film having a thickness of 100 μm: Nippon Electric Glass, trade name G-leaf) was bonded to produce a light control film 8 of the third embodiment shown in FIG.

<Example 4>
As Example 4, a light control film 7 having the structure of the first embodiment shown in FIG. 1 was produced as follows.

  Except for using a glass film having a thickness of 50 μm (trade name G-leaf, manufactured by Nippon Electric Glass) as the transparent incombustible film 4 and using an adhesive material (trade name: CATALYST9M, manufactured by Henkel Able Stick Japan) as the transparent adhesive layer 5, A light control film 7 having the structure of the first embodiment shown in FIG. 1 was produced under the same conditions and method as in Example 1.

<Comparative Example 1>
As Comparative Example 1, a light control film 6 having a conventional basic structure shown in FIG. 4 was prepared under the same conditions and method as in Example 1 until the light control film 6 having a conventional basic structure was manufactured.

<Comparative example 2>
As Comparative Example 2, a light control film having the same structure as that of the first embodiment shown in FIG. 1 was produced as follows.

  Dimming of the same structure as that of the first embodiment shown in FIG. 1 under the same conditions and method as in Example 1 except that a thin glass (made by Asahi Glass, product name AN100) having a thickness of 500 μm was used as the transparent noncombustible film 4. A film was prepared.

  The production conditions of the light control films of Examples 1 to 4 and Comparative Examples 1 to 2 are summarized in Table 2.

<Exothermic test and evaluation method>
A cone calorimeter exothermic test was performed. The light control films of Examples 1 to 4 and Comparative Examples 1 and 2 are bonded to a blue plate glass having a thickness of 5 mm and an area of 100 mm × 100 mm using an adhesive material (product name: CATALYST9M, manufactured by Henkel Able Stick Japan), and a cone heater. Radiant heat of 50 kW / m ^{2 was applied} , and the total calorific value and heat generation rate at that time were measured. The determination of flammability was performed according to the standards shown in Table 1 in accordance with ISO (International Organization for Standardization) 5660, ASTM (American Society for Testing Materials) E1354, NFPA (American Fire Protection Association Standard) 264A New Fire Protection Material Certification Test Method.

<Evaluation method of curved surface bonding property>
The light control films of Examples 1 to 4 and Comparative Examples 1 to 2 were bonded to the surface of a glass half pipe having a curvature of 1/20 cm using an adhesive, and the appearance was confirmed.

<Evaluation results>
Table 3 shows the evaluation results. In Examples 1 to 4, nonflammable materials were determined, and good curved surface bonding performance was obtained. In particular, in Example 4, the transparent incombustible film was a thin glass film having a thickness of 50 μm, but good results were obtained in both incombustibility and bonding properties.

On the other hand, in Comparative Example 1, the total calorific value was larger than 8 MJ / m ^{2 after a} heating time of 10 minutes, and it was determined as a flame retardant material. In Comparative Example 2, although the combustion classification was nonflammable, a thin glass sheet having a thickness of 500 μm was broken during curved surface bonding, and curved surface bonding was difficult.

  Moreover, the light control film of Examples 1-4 was connected to the power supply, and it confirmed that the light control function which switches transparency and opaqueness by switching the alternating voltage of voltage 30V was obtained.

DESCRIPTION OF SYMBOLS 1 ... Transparent organic film 2 ... Transparent conductive film 3 ... Liquid crystal light control layer 4 ... Transparent incombustible film 5 ... Transparent adhesive layer 6 ... Light control film (Conventional basic structure)
7, 8, 9, ... Light control film (structure of the present invention)

Claims (4)

A liquid crystal light control layer, and on both sides of the liquid crystal light control layer, a transparent conductive film and a transparent organic film are provided in this order,
A transparent non-combustible film is adhered to the transparent organic film on at least one surface via a transparent adhesive layer,
And the film thickness of the said transparent nonflammable film is 200 micrometers or less, The light control film characterized by the above-mentioned. A liquid crystal light control layer, and a transparent conductive film on both sides of the liquid crystal light control layer,
And a transparent non-combustible film on one surface of the transparent conductive film, a transparent organic film on the other surface,
And the film thickness of the said transparent nonflammable film is 200 micrometers or less, The light control film characterized by the above-mentioned. A liquid crystal light control layer, and on both sides of the liquid crystal light control layer, a transparent conductive film and a transparent incombustible film are provided in this order,
And the film thickness of the said transparent nonflammable film is 200 micrometers or less, The light control film characterized by the above-mentioned.   The said transparent nonflammable film is a laminated body containing a glass film or a glass film layer, The light control film as described in any one of Claims 1-3 characterized by the above-mentioned.

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