WO2019163872A1

WO2019163872A1 - Light control film

Info

Publication number: WO2019163872A1
Application number: PCT/JP2019/006476
Authority: WO
Inventors: 潤一馬場; 雅明浦野
Original assignee: 株式会社コムラテック; 潤一馬場
Priority date: 2018-02-22
Filing date: 2019-02-21
Publication date: 2019-08-29
Also published as: JP2019144460A; TW201940947A

Abstract

As a light control film that is capable of improving short circuit prevention properties, while being capable of simplifying the terminal formation work, the present invention provides a light control film that is provided with: a first substrate 1 which has insulating properties and light transmitting properties; a plurality of pairs of linear electrodes 2A, 2B which are formed on one surface of the first substrate 1; a liquid crystal layer 3 which is superposed on the electrode 2A, 2B formation surface of the first substrate 1, and which is formed from a composite material of a polymer and a liquid crystal; and a second substrate 4 which is superposed on the surface of the liquid crystal layer 3, and which has insulating properties and light transmitting properties.

Description

Light control film

This invention relates to the light control film which sticks to transparent plates, such as a window glass, and adjusts the light quantity which permeate | transmits the transparent plate.

2. Description of the Related Art Conventionally, as a light control film that is attached to, for example, a window glass and adjusts the amount of light transmitted through the window glass, a film using a liquid crystal layer made of a composite material of a polymer and a liquid crystal has been proposed (for example, Patent Documents). 1). This light control film is sandwiched between a pair of translucent substrates opposed to each other with a gap, planar transparent electrodes formed on the opposed inner surfaces of the translucent substrates, and the transparent electrodes. The liquid crystal layer is provided.

Then, by changing the voltage applied to the opposing transparent electrodes, the electric field generated between the opposing transparent electrodes (longitudinal direction) is changed, the orientation of the liquid crystal in the liquid crystal layer is changed, and the dimming is performed. The amount of light passing through the film can be adjusted.

International Publication No. 2010/100807

However, in the conventional light control film, since the transparent electrodes face each other with the liquid crystal layer interposed therebetween, the transparent electrodes are easily short-circuited. Therefore, a short circuit is prevented by setting the thickness of the liquid crystal layer between the transparent electrodes to a certain value or more. Moreover, since each transparent electrode is inside the light control film, a terminal forming process for exposing a terminal for supplying a voltage to each transparent electrode on the surface of the light control film is necessary. Since the transparent electrodes face each other, both sides of the light control film require terminal forming processing. There is room for improvement in these respects.

The present invention has been made in view of such circumstances, and provides a light control film that can improve short-circuit prevention and can simplify a terminal forming process.

In order to achieve the above object, a light control film of the present invention includes a first substrate having insulating properties and translucency, a pair or a plurality of pairs of linear electrodes formed on one surface of the first substrate, The liquid crystal layer which consists of a composite material of a polymer and a liquid crystal laminated | stacked on the said electrode formation surface of the said 1st board | substrate is taken.

The inventors of the present invention have repeatedly studied the structure of a light control film using a liquid crystal layer composed of a polymer and a liquid crystal composite material in order to improve short circuit prevention and simplify a terminal forming process. In the course of that research, I focused on the electrode and repeated further research. As a result, it was found that if the electrodes are formed in a pair or a plurality of pairs of lines, the amount of transmitted light can be adjusted even if the electrodes are formed only on one side of one substrate. In addition, it has been found that when the linear electrode is formed on only one surface of one substrate in this way, the short circuit prevention property is improved, and the terminal forming processing work is only required for one substrate.

That is, in the light control film of the present invention, when a voltage is applied to each pair of linear electrodes, an electric field is generated in parallel (lateral direction) to the surface of the substrate, and the liquid crystal in the liquid crystal layer is affected by the electric field. The orientation of is changed. And the light quantity which permeate | transmits a light control film can be adjusted now by the change of the orientation of the liquid crystal.

In the light control film of the present invention, a pair or a plurality of pairs of linear electrodes are formed on one surface of a first substrate having insulation and translucency, and a polymer and a liquid crystal are formed on the electrode formation surface of the first substrate. A liquid crystal layer made of the composite material is laminated. As described above, since the electrodes are not opposed to each other but formed on a single substrate, the short circuit prevention property is improved, and the reliability as the light control film can be improved. In addition, it is not necessary to increase the thickness of the liquid crystal layer in order to prevent a short circuit, and the degree of freedom in setting the thickness of the liquid crystal layer can be increased. Therefore, the liquid crystal layer can be thinned, and the light control film can be thinned. Furthermore, since the electrode is formed on one substrate, the terminal forming process for exposing the terminal for supplying voltage to the electrode on the surface of the light control film is only one side of the light control film. Can be simplified.

In particular, when a second substrate having insulation and translucency is laminated on the surface of the liquid crystal layer opposite to the first substrate, the second substrate of the liquid crystal layer is in contact. The surface can be protected. Therefore, stable light control can be performed over a long period.

In addition, when the electrodes are formed by a printing method, the linear electrodes can be made finer, and the degree of design freedom can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS The 1st Embodiment of the light control film of this invention is shown typically, (a) is the top view, (b) is XX sectional drawing of (a). It is sectional drawing which shows typically 2nd Embodiment of the light control film of this invention.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 (a) is a plan view showing a first embodiment of the light control film of the present invention, and FIG. 1 (b) is an XX sectional view of FIG. 1 (a). The light control film of this embodiment includes a first substrate 1 having insulating properties and translucency, a plurality of pairs of

linear electrodes

2A and 2B formed on one surface of the first substrate 1, and the first A liquid crystal layer 3 made of a composite material of polymer and liquid crystal is laminated on the surface on which the

electrodes

2A and 2B of the substrate 1 are formed, and an insulating and translucent layer laminated on the surface of the liquid crystal layer 3 is provided. 2 substrates 4.

More specifically, in the present embodiment, the first substrate 1 and the second substrate 4 are formed in a rectangular shape, both of which have the same vertical length, and the horizontal length is the first length. The substrate 1 is slightly longer. And the one end part (right side end part of illustration) of the 1st board | substrate 1 is not laminated | stacked but the liquid crystal layer 3 and the 2nd board | substrate 4 are exposed. In addition, the first substrate 1 and the second substrate 4 have insulating properties and translucency as described above, and examples of the forming material include glass and synthetic resin. The first substrate 1 and the second substrate 4 may be the same or different from each other, but are preferably the same from the viewpoint of productivity and the like. The thicknesses of the first substrate 1 and the second substrate 4 are usually set in the range of 15 to 250 μm. Note that in this specification, insulating means a property in which electricity or heat hardly flows, and transparency means that a substrate transmits electromagnetic waves such as light.

In this embodiment, the

electrodes

2A and 2B are a plurality of straight lines formed in a comb-like pattern, and the plurality of

straight electrodes

2A and 2B are formed from

rectangular electrode bases

21A and 21B. It is formed in a branched state. And two

electrode bodies

20A, 20B composed of the

electrode base portions

21A, 21B and the

linear electrodes

2A, 2B are formed, and between the adjacent linear electrodes 2A of one electrode body 20A, The linear electrode 2B of the other electrode body 20B enters the state. In this state, the adjacent linear electrode 2A of one electrode body 20A and the linear electrode 2B of the other electrode body 20B are paired. In this embodiment, a plurality of pairs are uniformly formed on a portion corresponding to substantially the entire surface of the liquid crystal layer 3. The one

end portions

22A and 22B of the

electrode base portions

21A and 21B are in the exposed portion of the first substrate 1 and are exposed, and serve as terminals for supplying a voltage to the

electrodes

2A and 2B from the outside. .

In addition, the width of one

linear electrode

2A, 2B is usually set to 15 μm or less, and in the range of 5 to 10 μm from the viewpoint of improving the reliability of voltage supply and forming the

electrodes

2A, 2B with high definition. It is preferable to set within. The gap width between the pair of

linear electrodes

2A and 2B is usually set within a range of 5 to 180 μm, and within a range of 15 to 130 μm from the viewpoint of improving the reliability of the generated electric field. It is preferable to set to.

Examples of the material for forming the

electrode bodies

20A and 20B include metals such as silver, copper, and gold, conductive polymers such as PEDOT: PSS, ITO (indium tin oxide), and the like. Among these, silver and copper are preferable from the viewpoint that the

linear electrodes

2A and 2B can be finely formed by printing. The two

electrode bodies

20A and 20B are both made of the same forming material and are preferably formed at the same time by printing or the like from the viewpoint of productivity. However, they are made of different forming materials and are separately formed. It may be formed by printing or the like.

As described above, the liquid crystal layer 3 is in the form of a film made of a composite material of polymer and liquid crystal. In other words, the liquid crystal layer 3 has a structure in which the liquid crystal is confined in a void of a skeleton in which a polymer is bonded in a sponge shape. Examples of the liquid crystal layer 3 having such a structure include a polymer network type liquid crystal (PNLC), a polymer dispersion type liquid crystal (PDLC: Polymer Dispersed Liquid), and the like. Examples of the polymer include polyfunctional acrylates, polyfunctional methacrylates, and photopolymerizable monomers. The thickness of the liquid crystal layer 3 is usually set in the range of 3 to 25 μm, and is preferably set in the range of 3 to 15 μm from the viewpoint of easily controlling the change in the alignment of the liquid crystal due to the electric field. .

In the light control film having such a configuration, a voltage is applied to the exposed

end portions

22A and 22B of the

electrode base portions

21A and 21B of the two

electrode bodies

20A and 20B, thereby forming a pair of linear shapes. An electric field is generated between the

electrodes

2A and 2B, and the alignment of the liquid crystal in the liquid crystal layer 3 changes. Thereby, the light quantity which permeate | transmits a light control film changes. That is, when the applied voltage is increased, the amount of light transmitted through the light control film increases (the light transmittance increases).

And the said light control film is affixed on the window glass, sunroof, etc. of a house, a motor vehicle, etc., and can change and use the light transmittance | permeability by application of a voltage as mentioned above. For the attachment, either the first substrate 1 or the second substrate 4 is attached to a window glass or the like. Further, when no voltage is applied, since the light transmittance is low, it can also be used as a screen for displaying an image.

The light control film can be produced, for example, as follows. That is, first, the first substrate 1 is prepared, and the

electrode bodies

20A and 20B including the

electrode bases

21A and 21B and the

linear electrodes

2A and 2B are formed on one surface of the first substrate 1 by printing or the like. To do. Then, the liquid crystal layer 3 and the second substrate 4 are prepared, and the first substrate 1 and the second substrate 4 are arranged so that the

electrode bodies

20A and 20B of the first substrate 1 and the second substrate 4 face each other. The liquid crystal layer 3 is sandwiched between the substrate 4 and the substrate 4. Thus, the said light control film can be produced.

Thus, since the

electrode bodies

20A and 20B composed of the

electrode base portions

21A and 21B and the

linear electrodes

2A and 2B are formed only on the first substrate 1, the short circuit prevention property is improved. Furthermore, the terminal forming process for supplying a voltage to the

linear electrodes

2A and 2B is to form the one

end portions

22A and 22B of the

electrode base portions

21A and 21B in the exposed portion of the first substrate 1. The terminal forming process can be simplified.

In addition, as a printing method of the

electrode bodies

20A and 20B, any conventionally known printing method may be used. For example, a printing method by inkjet printing, screen printing, gravure printing, gravure offset printing, flexographic printing, reverse offset printing, or the like may be used. can give. Among these, gravure offset printing is preferable from the viewpoint of forming the

electrodes

2A and 2B more precisely. And since the said printing method uses the printing plate produced previously, it is preferable at the point which can form

electrode body

20A, 20B easily. Further, when the material for forming the

electrode bodies

20A and 20B is ITO, the

electrode bodies

20A and 20B are formed by etching or the like. Thus, the

electrode bodies

20A and 20B are formed by an appropriate method according to the material for forming the

electrode bodies

20A and 20B.

FIG. 2 is a cross-sectional view (a cross-sectional view corresponding to FIG. 1 (b)) showing a second embodiment of the light control film of the present invention. The light control film of this embodiment is not provided with the second substrate 4 [see FIG. 1 (b)] in the light control film of the first embodiment shown in FIGS. 1 (a) and 1 (b). Is. The other parts are the same as those in the first embodiment, and the same reference numerals are given to the same parts.

In this embodiment, similarly to the first embodiment, the light transmittance can be changed by applying a voltage, and the same operations and effects as in the first embodiment can be obtained. In this embodiment, the attachment to the window glass or the like attaches either the first substrate 1 or the liquid crystal layer 3 to the window glass or the like.

In each of the above embodiments, the

electrodes

2A and 2B of the

electrode bodies

20A and 20B are linear, but other shapes may be used as long as an electric field can be generated between the pair of

electrodes

2A and 2B. For example, a zigzag shape, a wave shape, a spiral shape, or the like may be used. And you may combine those 2 or more types of shapes.

In each of the above embodiments, the plurality of pairs of

electrodes

2A and 2B are uniformly formed on the portion corresponding to substantially the entire surface of the liquid crystal layer 3, but may be formed non-uniformly. That is, a region where the plurality of pairs of

electrodes

2A and 2B are formed and a region where the pairs are not formed may be set. Furthermore, the gap width between the paired

electrodes

2A and 2B may be changed, and for example, a region having a small gap width and a region having a large gap width may be set. By doing in this way, in the light control film of 1 sheet, the area | region where the transmittance | permeability of light differs can be made, and it can be set as the light control film rich in design property.

In the above embodiments, a plurality of pairs of the

electrodes

2A and 2B are formed, but only one pair may be used.

Next, examples will be described. However, the present invention is not limited to the examples.

[Examples 1 to 4]
[First substrate on which electrodes are formed]
In the same manner as the first embodiment shown in FIGS. 1A and 1B, a first substrate (thickness 250 μm) made of PET (polyethylene terephthalate) is prepared, and an electrode base is formed on one surface of the first substrate. And a linear electrode made of a linear electrode were formed by gravure offset printing. At that time, four examples (Examples 1 to 4) in which the width of the electrode and the gap width between the pair of electrodes were changed were produced. The widths of the electrodes and the gap width are shown in Table 1 below.

[Light transmittance of the first substrate on which the electrodes are formed]
With respect to the first substrate on which the electrodes were formed, the transmittance of parallel light was measured without applying a voltage, and the results are shown in Table 1 below. For the measurement, a visible light transmittance measuring device (manufactured by Sato Corporation, glass visible light transmittance measuring device Tint Meter MJ-TM100) was used.

[Liquid crystal layer]
As a liquid crystal layer, KN-221W (thickness: 10 μm, polymer: polyfunctional acrylate) manufactured by Kyushu Nanotech Optical Co., Ltd. was prepared.

[Second board]
The thing made from PET (thickness 50 micrometers) was prepared as a 2nd board | substrate.

[Production of light control film]
The liquid crystal layer was sandwiched between the first substrate and the second substrate so that the electrode body of the first substrate faced the second substrate. Thereby, the light control films of Examples 1 to 4 similar to those of the first embodiment shown in FIGS. 1A and 1B were produced.

When producing this light control film, there was no short circuit of the electrode body, and it was not necessary to pay particular attention to prevent the short circuit. Moreover, since the terminal formation process for supplying a voltage to a linear electrode was to form the one end part of the said electrode base part in the part to expose of a 1st board | substrate, the terminal formation process work is easy. there were.

[Light transmittance of light control film]
In the light control films of Examples 1 to 4, the applied voltage was changed and the transmittance of parallel light was measured. For this measurement, a visible light transmittance measuring device similar to the above was used. The results are shown in Table 1 below.

From the results in Table 1, it can be seen that the light transmittance of the light control films of Examples 1 to 4 increases as the applied voltage is increased. In other words, the light control films of Examples 1 to 4 can change the amount of light to be transmitted by changing the applied voltage.

Also, in Examples 1 to 4 above, a light control film (see FIG. 2) without the second substrate was produced. These light control films also obtained results showing the same tendency as in Examples 1 to 4 above.

In the above embodiments, specific forms in the present invention have been described. However, the above embodiments are merely examples and are not construed as limiting. Various modifications apparent to those skilled in the art are contemplated to be within the scope of this invention.

The light control film of the present invention is attached to a window glass, sunroof or the like of a house or an automobile, and can be used when changing the light transmittance.

DESCRIPTION OF SYMBOLS 1 1st board |

substrate

2A, 2B electrode 3 Liquid crystal layer 4 2nd board | substrate

Claims

A first substrate having insulation and translucency, a pair or a plurality of pairs of linear electrodes formed on one surface of the first substrate, and a polymer laminated on the electrode formation surface of the first substrate And a liquid crystal layer made of a composite material of liquid crystal.
The light control film according to claim 1, wherein a second substrate having insulating properties and translucency is laminated on a surface of the liquid crystal layer opposite to the first substrate.
The light control film according to claim 1 or 2, wherein the electrode is formed by a printing method.