JP2018128566A - Dimming sheet and dimming body - Google Patents
Dimming sheet and dimming body Download PDFInfo
- Publication number
- JP2018128566A JP2018128566A JP2017021259A JP2017021259A JP2018128566A JP 2018128566 A JP2018128566 A JP 2018128566A JP 2017021259 A JP2017021259 A JP 2017021259A JP 2017021259 A JP2017021259 A JP 2017021259A JP 2018128566 A JP2018128566 A JP 2018128566A
- Authority
- JP
- Japan
- Prior art keywords
- light control
- transparent
- layer
- film
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
Description
本発明は、液晶を用いた調光層を、透明電極を形成した透明性基材で挟持した調光シート、及び調光シートをさらにガラス板、アクリル板などのリジッドな高強度透明性基材で固定した調光体に関する。 The present invention relates to a light control sheet in which a light control layer using liquid crystal is sandwiched by a transparent base material on which a transparent electrode is formed, and a rigid high strength transparent base material such as a glass plate or an acrylic plate. It is related with the light control body fixed by.
調光シートは、透明電極間に挟持された調光層を備え、電極に印加する電圧により調光層に含まれる液晶分子の配向状態を変化させて、入射光を散乱する不透明状態と、入射光を透過する透明状態とを切り替え可能なように構成されている。尚、調光シートの不透明度（散乱度）は通常ヘイズ（Ｈａｚｅ）と呼ばれる。 The light control sheet includes a light control layer sandwiched between transparent electrodes, changes the alignment state of liquid crystal molecules contained in the light control layer by a voltage applied to the electrodes, and scatters incident light and incident light. It is configured to be switchable between a transparent state that transmits light. In addition, the opacity (scattering degree) of the light control sheet is usually called haze.
前記調光シートは、調光層を透明導電膜により透明電極を形成したガラス基材やフレキシブルなプラスチックフィルム基材で挟持した後、高強度透明性基材に固定することで窓ガラスや展示ウィンドウ、パーテーションなどに採用することができ、例えばプライベート空間とパブリック空間とを分離する設備の他、自動車のサンルーフやサンバイザー用途としての利用についても検討されている。 The light control sheet is sandwiched between a glass base material in which a transparent electrode is formed by a transparent conductive film or a flexible plastic film base material, and then fixed to a high-strength transparent base material so that a window glass or an exhibition window is provided. For example, in addition to equipment for separating private space and public space, use as a sunroof or a sun visor for automobiles is also being studied.
前記のような用途では不透明時に光散乱性を有し視界を遮断する一方で、透明時には十分な視界を確保することが必要である。すなわち、不透明時の光散乱性を低下させることなく、透明時には透過率を可能な限り向上させる必要があり、光散乱性と透明性を両立させることが求められている。 In the above applications, it is necessary to ensure a sufficient field of view when transparent, while having a light scattering property when opaque and blocking the field of view. That is, it is necessary to improve the transmittance as much as possible when it is transparent without reducing the light scattering property when it is opaque, and it is required to achieve both light scattering property and transparency.
透明時の透過率を向上させる方法としては、調光シートや調光体の表面に反射防止層を設けることが考えられ、特許文献１に記載されている。しかしながら、特許文献１の記載は、不透明時の光散乱性との両立という観点、及び実用的な反射防止構造の観点からは十分に検討されているとはいえないものであった。 As a method for improving the transmittance when transparent, it is conceivable to provide an antireflection layer on the surface of the light control sheet or the light control body, which is described in Patent Document 1. However, the description of Patent Document 1 cannot be said to have been sufficiently studied from the viewpoint of compatibility with light scattering properties when opaque and from the viewpoint of a practical antireflection structure.
本発明は、上記の課題を解決するためになされたもので、その目的とするところは、窓ガラスやパーテーションとして使用する際、不透明時の視界遮断に必要な光散乱性を低下させることなく、透明時の視界確保に必要十分な透過性を得ることができる調光シート及び調光体を提供することにある。 The present invention was made in order to solve the above problems, and its purpose is to reduce the light scattering property necessary for blocking the visibility when opaque when used as a window glass or a partition, An object of the present invention is to provide a light control sheet and a light control body capable of obtaining transparency sufficient for securing a field of view when transparent.
上述の問題を解決するために、請求項１に記載の発明は、高分子ネットワーク型液晶（ＰＮＬＣ）を用いる調光層と、前記調光層の両側の面に、透明導電膜からなる電極と、透明性基材とをこの順に備える調光シートであって、
前記高分子ネットワークにより形成されたドメインの径が４００〜８００ｎｍであり、
かつ少なくとも一方の面の前記透明性基材の外表面上に反射防止層を備え、
かつ前記反射防止層を含む前記透明性基材の外表面上の反射率が、３８０〜７８０ｎｍの波長域において４％以下であることを特徴とする調光シートとしたものである。ここでドメインの径とは、平面視でＸ方向（前記調光シートの長さ方向）の最大の長さとＹ方向（前記調光シートの幅方向）の最大の長さの平均とする。
In order to solve the above-mentioned problem, the invention described in claim 1 includes a light control layer using a polymer network type liquid crystal (PNLC), and electrodes made of a transparent conductive film on both sides of the light control layer. , A light control sheet comprising a transparent substrate in this order,
The diameter of the domain formed by the polymer network is 400-800 nm,
And an antireflection layer is provided on the outer surface of the transparent substrate on at least one surface,
And the reflectance on the outer surface of the said transparent base material containing the said antireflection layer is a light control sheet | seat characterized by being 4% or less in the wavelength range of 380-780 nm. Here, the diameter of the domain is an average of the maximum length in the X direction (length direction of the light control sheet) and the maximum length in the Y direction (width direction of the light control sheet) in plan view.
請求項２に記載の発明は、少なくとも一方の面の前記透明導電膜の膜厚は、該透明導電膜の両側の界面における反射光の干渉に依る反射率が３８０〜７８０ｎｍの波長域において４％以下となる膜厚であることを特徴とする請求項１に記載の調光シートとしたものである。 According to a second aspect of the present invention, the film thickness of the transparent conductive film on at least one surface is 4% in a wavelength range where the reflectance due to interference of reflected light at the interfaces on both sides of the transparent conductive film is 380 to 780 nm. It is set as the light control sheet | seat of Claim 1 characterized by the following film thickness.
請求項３に記載の発明は、高分子ネットワーク型液晶（ＰＮＬＣ）を用いる調光層と、前記調光層の両側の面に、透明導電膜からなる電極と、透明性基材この順に備える調光シートの少なくとも一方の面に、高強度透明性基材が貼合された調光体であって、
前記高分子ネットワークにより形成されたドメインの径が４００〜８００ｎｍであり、
かつ前記高強度透明性基材の外表面上に反射防止層を備え、
かつ前記反射防止層を含む前記高強度透明性基材の外表面上の反射率が、３８０〜７８０ｎｍの波長域において４％以下であることを特徴とする調光体としたものである。ここでドメインの径とは、平面視でＸ方向（前記調光シートの長さ方向）の最大の長さとＹ方向（前記調光シートの幅方向）の最大の長さの平均とする。
According to a third aspect of the present invention, there is provided a light control layer using a polymer network type liquid crystal (PNLC), an electrode made of a transparent conductive film on both sides of the light control layer, and a transparent base material in this order. A light control body in which a high-strength transparent base material is bonded to at least one surface of the light sheet,
The diameter of the domain formed by the polymer network is 400-800 nm,
And an antireflection layer on the outer surface of the high-strength transparent substrate,
And the reflectance on the outer surface of the said high intensity | strength transparent base material containing the said anti-reflective layer is 4% or less in the wavelength range of 380-780 nm, It is set as the light control body characterized by the above-mentioned. Here, the diameter of the domain is an average of the maximum length in the X direction (length direction of the light control sheet) and the maximum length in the Y direction (width direction of the light control sheet) in plan view.
請求項４に記載の発明は、少なくとも一方の面の前記透明導電膜の膜厚は、該透明導電膜の両側の界面における反射光の干渉に依る反射率が３８０〜７８０ｎｍの波長域において４％以下となる膜厚であることを特徴とする請求項３に記載の調光体としたものである。 According to a fourth aspect of the present invention, the film thickness of the transparent conductive film on at least one surface is 4% in a wavelength range where the reflectance due to interference of reflected light at the interfaces on both sides of the transparent conductive film is 380 to 780 nm. It is set as the light control body of Claim 3 characterized by the following film thickness.
請求項５に記載の発明は、前記透明性基材と前記高強度透明性基材の層間に透明性接着層を備え、前記透明性接着層の膜厚は、該透明性接着層の両側の界面における反射光の干渉に依る反射率が３８０〜７８０ｎｍの波長域において４％以下となる膜厚であることを特徴とする請求項３または４に記載の調光体としたものである。 The invention according to claim 5 comprises a transparent adhesive layer between the transparent substrate and the high-strength transparent substrate, and the film thickness of the transparent adhesive layer is on both sides of the transparent adhesive layer. 5. The light control body according to claim 3, wherein the reflectivity due to interference of reflected light at the interface is 4% or less in a wavelength range of 380 to 780 nm.
本発明によると、高分子ネットワーク型液晶（ＰＮＬＣ）を用いる調光層において、高分子ネットワークにより形成されたドメインの径が４００〜８００ｎｍであり、かつ少なくとも一方の面の透明性基材（または高強度透明性基材）の外表面に反射防止層を備え、かつ前記反射防止層を含む前記透明性基材（または高強度透明性基材）の外表面の反射率が、３８０〜７８０ｎｍの波長域において４％以下である調光シート（または調光体）としたので、不透明時の視界遮断に必要な光散乱性と、透明時の視界確保に必要十分な透過性を両立させるとともに、実用性をも兼ね備えた調光シート（または調光体）を得ることができる。 According to the present invention, in the light control layer using the polymer network type liquid crystal (PNLC), the diameter of the domain formed by the polymer network is 400 to 800 nm, and the transparent substrate (or high surface) on at least one surface is used. A wavelength of 380 to 780 nm in which the reflectance of the outer surface of the transparent substrate (or high-strength transparent substrate) including the antireflection layer is provided on the outer surface of the strength transparent substrate) The light control sheet (or light control body) is 4% or less in the area, so that both the light scattering required for blocking the field of view when opaque and the sufficient and sufficient transparency for securing the field of view when transparent are used. The light control sheet (or light control body) which has the property can also be obtained.
以下、本発明の実施形態に係る調光シート及び調光体を詳細に説明する。尚、同一の構成要素については便宜上の理由がない限り同一の符号を付け、重複する説明は省略する。また、以下の説明で用いる図面は、特徴をわかりやすくするために、特徴となる部分を拡大して示している場合があり、各構成要素の寸法比率などは実際と同じではない。 Hereinafter, the light control sheet and light control body which concern on embodiment of this invention are demonstrated in detail. 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.
（ＰＮＬＣを用いる調光シートの説明）
調光層に用いられる高分子液晶にはいくつかの種類があるが、代表的なものとして高分子ネットワーク型液晶（ＰＮＬＣ：Ｐｏｌｙｍｅｒ Ｎｅｔｗｏｒｋ Ｌｉｑｕｉｄ Ｃｒｙｓｔａｌ）と呼ばれるタイプがある。
(Description of light control sheet using PNLC)
There are several types of polymer liquid crystal used for the light control layer, but a typical type is called a polymer network type liquid crystal (PNLC).
図１はＰＮＬＣ型調光層３を備える調光シート５０の構造と、（ａ）不透明状態、（ｂ）透明状態の挙動を示す模式断面図である。ＰＮＬＣ型では、液晶分子５は高分子ネットワーク４と呼ばれる３次元網目構造により形成されたドメイン６（例えば図１（ａ）の斜線部で例示する領域）の中に位置している。 FIG. 1 is a schematic cross-sectional view showing the structure of a light control sheet 50 including the PNLC-type light control layer 3, and the behavior of (a) an opaque state and (b) a transparent state. In the PNLC type, the liquid crystal molecules 5 are located in a domain 6 (for example, a region illustrated by a hatched portion in FIG. 1A) formed by a three-dimensional network structure called a polymer network 4.
光散乱層となるＰＮＬＣ型調光層では、相分離において未反応成分が殆どなく、高分子ネットワークと液晶領域が高い純度で明確に分かれる挙動を示す。また、基板のラビングによるプレチルト配向処理を行なうことなく、理想的な配向状態を実現することが可能であり、液晶分子は高分子ネットワークによって分割されたドメインごとにほぼ一様に配向する。ＰＮＬＣのドメインは、サイズが約１μｍと微細であり、レイリー散乱（波長選択的な散乱）は招かず、少なくとも可視光領域波長（４００〜７８０ｎｍ）を含む広い波長域の散乱が効率的に発生する。 In the PNLC type light control layer serving as the light scattering layer, there is almost no unreacted component in the phase separation, and the polymer network and the liquid crystal region are clearly separated with high purity. Further, an ideal alignment state can be realized without performing a pretilt alignment process by rubbing the substrate, and the liquid crystal molecules are aligned substantially uniformly for each domain divided by the polymer network. The PNLC domain is as small as about 1 μm in size, does not cause Rayleigh scattering (wavelength selective scattering), and efficiently scatters in a wide wavelength range including at least the visible light region wavelength (400 to 780 nm). .
図１（ａ）の不透明状態においては、ドメイン６中の液晶分子５は任意の方向に配列しており、液晶分子５の屈折率に依るドメイン６の屈折率と高分子ネットワーク４の屈折率の差が大きくなるため、入射光２１は高分子ネットワーク４とドメイン６の界面で多重散乱し散乱光２２が顕著となって、高ヘイズ状態となり白濁化する。 In the opaque state of FIG. 1A, the liquid crystal molecules 5 in the domain 6 are arranged in an arbitrary direction, and the refractive index of the domain 6 depending on the refractive index of the liquid crystal molecules 5 and the refractive index of the polymer network 4 are determined. Since the difference becomes large, the incident light 21 undergoes multiple scattering at the interface between the polymer network 4 and the domain 6, and the scattered light 22 becomes noticeable, resulting in a high haze state and white turbidity.
一方、図１（ｂ）の透明状態においては、ドメイン６中の液晶分子５は電界方向に配列しており、ドメイン６中の液晶分子５の屈折率は長軸方向の屈折率となり、ドメイン６の屈折率は高分子ネットワーク４の屈折率に近くなるため、光散乱は小さくなり透過光２３が顕著となって、低ヘイズ状態となり透明化する。 On the other hand, in the transparent state of FIG. 1B, the liquid crystal molecules 5 in the domain 6 are aligned in the electric field direction, and the refractive index of the liquid crystal molecules 5 in the domain 6 is the refractive index in the major axis direction. Is close to that of the polymer network 4, light scattering is reduced, the transmitted light 23 becomes noticeable, and a low haze state is achieved and the film becomes transparent.
透過光の「遮光（遮断）⇔透明（透過）」でなく、「不透明（散乱透過）⇔透明（非散乱透過）」の変化を奏する本発明の調光シートにおいても、ＣＲＴ、ＬＥＤ、ＰＤＰ、ＥＬＤなどの各種ディスプレイに適用され、外光の反射（ギラツキ）、像の映り込みによる視認性の低下を防止する目的で採用される、防眩性フィルム（ＡＧ＝ａｎｔｉ ｇｌａｒｅ）、反射防止フィルム（ＡＲ＝ａｎｔｉ ｒｅｆｌｅｃｔｉｏｎ）、低反射フィルム（ＬＲ＝ｌｏｗ ｒｅｆｌｅｃｔｉｏｎ）の適用が有効である。 Even in the light control sheet of the present invention that exhibits a change of “opaque (scattering transmission) ⇔transparent (non-scattering transmission)” instead of “light shielding (blocking) ⇔transparent (transmission)” of transmitted light, CRT, LED, PDP, Anti-glare film (AG = anti glare), anti-reflection film (AG), which is applied to various displays such as ELD, and is used for the purpose of preventing external light reflection (glare) and deterioration of visibility due to image reflection. AR = anti reflection) and application of a low reflection film (LR = low reflection) are effective.
（本発明の第１の実施形態である調光シートの説明）
図２（ａ）は、本発明の第１の実施形態である調光シートの第１の例を示す模式断面図である。本例の調光シート１０は、ＰＮＬＣを用いる調光層３と、調光層３の両側の面に、透明導電膜２ａ、２ｂからなる電極と、ガラスやプラスチックフィルムからなる透明性基材１ａ、１ｂとをこの順に備えている。また、少なくとも一方の面（図２（ａ）では両側の面）の前記透明性基材の外表面に反射防止層（図２（ａ）では反射防止膜７ａ、７ｂ）を備え、反射防止層を含む透明性基材１ａ、１ｂの外表面の反射率は、３８０〜７８０ｎｍの波長域において４％以下となっている。３８０〜７８０ｎｍの波長域とする理由は、透明状態で対象となるのは可視光域の光だからである。
(Description of the light control sheet which is the 1st Embodiment of this invention)
Fig.2 (a) is a schematic cross section which shows the 1st example of the light control sheet which is the 1st Embodiment of this invention. The light control sheet 10 of this example includes a light control layer 3 using PNLC, transparent electrodes 1a and 2b on both sides of the light control layer 3, and a transparent substrate 1a made of glass or plastic film. 1b in this order. Further, an antireflection layer (antireflection films 7a and 7b in FIG. 2 (a)) is provided on the outer surface of the transparent substrate on at least one surface (both surfaces in FIG. 2 (a)), and the antireflection layer is provided. The reflectance of the outer surface of the transparent base materials 1a and 1b containing 4 is 4% or less in the wavelength range of 380 to 780 nm. The reason why the wavelength range is 380 to 780 nm is that light in the visible state is targeted in the transparent state.
さらに、本発明の第１の実施形態である調光シートでは、上述の高分子ネットワークにより形成されたドメインの径がいずれも４００〜８００ｎｍである。ここでドメインの径とは、平面視でＸ方向（前記調光シートの長さ方向）の最大の長さとＹ方向（前記調光シートの幅方向）の最大の長さの平均であり、ドメイン６を図示した図２（ｃ）中の記号で表わせば、（Ｌｘ＋Ｌｙ）／２である。 Furthermore, in the light control sheet which is the 1st Embodiment of this invention, all the diameters of the domain formed of the above-mentioned polymer network are 400-800 nm. Here, the diameter of the domain is an average of the maximum length in the X direction (the length direction of the light control sheet) and the maximum length in the Y direction (the width direction of the light control sheet) in plan view. If 6 is represented by the symbol in FIG. 2C, it is (Lx + Ly) / 2.
ドメインの径を平面視の大きさで規定する理由は、光の進行方向がＺ方向（断面方向）であるため、散乱に影響するのは平面視での大きさだからである。また、４００〜８００ｎｍに規定する理由は、４００ｎｍより小さい場合は不透明時の可視光波長以下（４００ｎｍ以下）のヘイズが低下してしまい、８００ｎｍより大きい場合は不透明時の可視光波長以上（８００ｎｍ以上）のヘイズが低下してしまうため、それを補うために調光層の厚みを増加する必要があり、この結果透明時の透過率の低下をもたらすからである。 The reason why the diameter of the domain is defined by the size in plan view is that the traveling direction of light is the Z direction (cross-sectional direction), and therefore, it is the size in plan view that affects the scattering. Moreover, the reason for prescribing to 400 to 800 nm is that when the wavelength is smaller than 400 nm, the haze below the visible light wavelength when opaque (400 nm or less) is lowered, and when it is larger than 800 nm, it is longer than the visible light wavelength when opaque (800 nm or more). This is because the thickness of the light control layer needs to be increased in order to compensate for this, resulting in a decrease in transmittance when transparent.
図２（ａ）の第１の例の調光シート１０では両側の面の透明性基材１ａ、１ｂの外表面に反射防止層としてそれぞれ単層の反射防止膜７ａ、７ｂを備え、図２（ｂ）の第２の例の調光シート２０では両側の透明性基材１ａ、１ｂの外表面に反射防止層としてそれぞれ２層構成の反射防止膜８ａ、９ａと８ｂ、９ｂを備えている。反射防止膜は３層以上であってもいが、コスト、生産性を考慮すれば、せいぜい２層以下であることが好ましい。 The light control sheet 10 of the first example in FIG. 2A includes single-layer antireflection films 7a and 7b as antireflection layers on the outer surfaces of the transparent substrates 1a and 1b on both sides, respectively. In the light control sheet 20 of the second example of (b), antireflection films 8a, 9a and 8b, 9b having a two-layer structure are provided on the outer surfaces of the transparent substrates 1a, 1b on both sides as antireflection layers, respectively. . The antireflection film may have three or more layers, but in consideration of cost and productivity, it is preferably at most two layers.
調光シートや調光体の表面に設ける反射防止層としては、反射防止膜を用いる方法と、表面に蛾の目（モスアイ）構造などの微細構造を形成する方法があるが、反射防止膜を用いる場合は原理上透明時の光散乱性には関係しない。また微細構造を形成する場合も、少なくとも波長以下のナノメーターオーダーの凹凸をもつ微細構造とすれば光散乱を抑えることができる。従って、適切な大きさのドメインと反射防止層を有する本発明の調光シート及び調光体では、不透明時の散乱性を維持したまま透明時には透過性を向上することができる。 As the antireflection layer provided on the surface of the light control sheet or the light control body, there are a method of using an antireflection film and a method of forming a fine structure such as a moth-eye structure on the surface. When used, it is not related to the light scattering property when transparent. In the case of forming a fine structure, light scattering can be suppressed if the fine structure has at least nanometer-order irregularities of a wavelength or less. Therefore, in the light control sheet and light control body of the present invention having an appropriately sized domain and antireflection layer, the transparency can be improved when transparent while maintaining the scattering property when opaque.
第１の実施形態である調光シートでは、透明導電膜の膜厚は、該透明導電膜の両側の界面、すなわち透明性基材との界面及び調光層との界面における、それぞれの反射光の干渉に依る反射率が３８０〜７８０ｎｍの波長域において４％以下となる膜厚であることが好ましい。さらに好ましくは３％以下である。これらについては、後述のシミュレーションによる反射率の計算結果を用いてさらに説明する。 In the light control sheet which is 1st Embodiment, the film thickness of a transparent conductive film has each reflected light in the interface of the both sides of this transparent conductive film, ie, the interface with a transparent base material, and the interface with a light control layer. The film thickness is preferably 4% or less in the wavelength range of 380 to 780 nm. More preferably, it is 3% or less. These will be further described using the calculation result of the reflectance by the simulation described later.
（本発明の第２の実施形態である調光体の説明）
図３（ａ）は、本発明の第２の実施形態である調光体の第１の例を示す模式断面図である。本例の調光体３０は、上述の第１の実施例の調光シートと同様、ＰＮＬＣを用いる調光層３と、調光層３の両側の面に、透明導電膜２ａ、２ｂからなる電極と、ガラスやプラスチックフィルムからなる透明性基材１ａ、１ｂとをこの順に備えている。また、透明性基材１ａ、１ｂの少なくとも一方の面（図３（ａ）では両側の面）にはガラス板やアクリル板などからなる高強度透明性基材１１ａ、１１ｂが貼合されている。さらに、少なくとも一方の面（図３（ａ）では両側の面）の高強度透明性基材の外表面に反射防止層（図３
（ａ）では反射防止膜１７ａ、１７ｂ）を備え、反射防止層を含む高強度透明性基材１１ａ、１１ｂの外表面の反射率は、３８０〜７８０ｎｍの波長域において４％以下となっている。
(Description of the light control body which is the 2nd Embodiment of this invention)
Fig.3 (a) is a schematic cross section which shows the 1st example of the light control body which is the 2nd Embodiment of this invention. The light control body 30 of this example is composed of a light control layer 3 using PNLC and transparent conductive films 2a and 2b on both sides of the light control layer 3, as in the light control sheet of the first embodiment. An electrode and transparent substrates 1a and 1b made of glass or plastic film are provided in this order. Moreover, the high intensity | strength transparent base materials 11a and 11b which consist of a glass plate, an acrylic board, etc. are bonded to the at least one surface (surface of FIG. 3 (a) on both sides) of the transparent base materials 1a and 1b. . Further, an antireflection layer (FIG. 3) is formed on the outer surface of the high-strength transparent substrate on at least one surface (the surfaces on both sides in FIG. 3 (a)).
(A) includes antireflection films 17a and 17b), and the reflectance of the outer surface of the high-strength transparent base materials 11a and 11b including the antireflection layer is 4% or less in the wavelength range of 380 to 780 nm. .
本発明の第２の実施形態である調光体の特徴を、上述の第１の実施形態である調光シートと比較すると、高強度透明性基材を備え、反射防止層が透明性基材ではなく高強度透明性基材の外表面に設けてある以外は第１の実施形態である調光シートと同じである。すなわち、調光層のドメインの径は４００〜８００ｎｍであり、図３（ｂ）の第２の例の調光体４０では両側の高強度透明性基材１１ａ、１１ｂの外表面にそれぞれ２層構成の反射防止膜１８ａ、１９ａと１８ｂ、１９ｂを備えている。また、透明導電膜の膜厚は、該透明導電膜の両側の界面における、それぞれの反射光の干渉に依る反射率が３８０〜７８０ｎｍの波長域において４％以下となる膜厚であることが好ましいことも同じである。 When the characteristics of the light control body according to the second embodiment of the present invention are compared with the light control sheet according to the first embodiment described above, the light control sheet includes a high-strength transparent base material, and the antireflection layer is a transparent base material. Instead, it is the same as the light control sheet of the first embodiment except that it is provided on the outer surface of the high-strength transparent substrate. That is, the domain diameter of the light control layer is 400 to 800 nm. In the light control body 40 of the second example in FIG. 3B, two layers are provided on the outer surfaces of the high-strength transparent base materials 11a and 11b on both sides. Antireflection films 18a, 19a and 18b, 19b having the configuration are provided. Further, the film thickness of the transparent conductive film is preferably such that the reflectivity due to interference of reflected light at the interfaces on both sides of the transparent conductive film is 4% or less in the wavelength range of 380 to 780 nm. The same is true.
第２の実施形態である調光体では、前述のように、透明性基材と高強度透明性基材を貼合する。貼合する方法は材料に依存するが、透明性基材と高強度透明性基材の屈折率差が大きい場合は、透明性基材と高強度透明性基材の層間に、透明性接着層（図示せず）を備えることが好ましい。透明性接着層としては、透明性接着剤、透明性粘着剤の他、熱ラミネート可能な材料を用いることができる。いずれの透明性接着層を用いる場合も、膜厚は該透明性接着層の両側の界面、すなわち透明性基材との界面及び高強度透明性基材との界面における、それぞれの反射光の干渉に依る反射率が３８０〜７８０ｎｍの波長域において４％以下となる膜厚とすることが好ましい。 In the light control body which is 2nd Embodiment, as mentioned above, a transparent base material and a high intensity | strength transparent base material are bonded. The method of pasting depends on the material, but if the difference in refractive index between the transparent substrate and the high-strength transparent substrate is large, the transparent adhesive layer is placed between the transparent substrate and the high-strength transparent substrate. (Not shown) is preferably provided. As the transparent adhesive layer, a heat-laminable material can be used in addition to the transparent adhesive and the transparent adhesive. Regardless of which transparent adhesive layer is used, the film thickness is the interference of the reflected light at the interfaces on both sides of the transparent adhesive layer, that is, the interface with the transparent substrate and the interface with the high-strength transparent substrate. The film thickness is preferably 4% or less in the wavelength range of 380 to 780 nm.
（調光シートにおける反射と反射防止膜の検討）
以下、反射防止層としての単層または２層の反射防止膜を好適に選択する方法をシミュレーションにより検討した例を説明する。尚、主として調光シートについて述べるが、調光体の場合は、「透明性基材」の語句を「高強度透明性基材」に置き換えればよい。
(Examination of reflection and antireflection film in light control sheet)
Hereinafter, an example will be described in which a method for suitably selecting a single-layer or two-layer antireflection film as the antireflection layer is examined by simulation. Although the light control sheet will be mainly described, in the case of a light control body, the phrase “transparent substrate” may be replaced with “high strength transparent substrate”.
はじめに、調光シートにおける反射の特徴について考察する。一般に光反射は物質中で「屈折率」が変化する箇所で発生する。ここで「屈折率」としては、吸収性物質の場合、通常の屈折率と消衰係数からなる複素屈折率を使う必要があるが、調光シートで使用する材料はいずれも可視光域で透明性であるため、通常の屈折率を考慮すれば十分である（以下、光学理論については非特許文献１参照）。 First, the characteristics of reflection in the light control sheet will be considered. In general, light reflection occurs in a material where the “refractive index” changes. Here, as the “refractive index”, in the case of an absorptive substance, it is necessary to use a complex refractive index consisting of a normal refractive index and an extinction coefficient, but all materials used in the light control sheet are transparent in the visible light range. Therefore, it is sufficient to consider a normal refractive index (refer to Non-Patent Document 1 for optical theory hereinafter).
調光シートの反射光は、図４（ａ）に示すように、（１）〜（６）の６つの界面で発生する。ここで特徴的なことは、透明導電膜２ａ、２ｂの厚さは通常１００〜２００ｎｍと薄い反面、透明性基材１ａ、１ｂの厚さは２０〜１００μｍ、調光層３の厚さは１０〜５０μｍと、可視光波長に比べ桁違いに厚いということである。従って、一般に薄膜の積層体はいわゆる薄膜干渉を考慮する必要があるが、調光シートの場合、干渉については透明導電膜２ａの両側の界面の反射光Ｒ２とＲ３（透明導電膜２ｂについてはＲ４とＲ５）による干渉を考慮すれば十分ということである。 The reflected light of the light control sheet is generated at the six interfaces (1) to (6) as shown in FIG. What is characteristic here is that the thickness of the transparent conductive films 2a and 2b is usually as thin as 100 to 200 nm, while the thickness of the transparent substrates 1a and 1b is 20 to 100 μm, and the thickness of the light control layer 3 is 10 mm. It is about 50 μm, which is an order of magnitude thicker than the visible light wavelength. Therefore, it is generally necessary to consider so-called thin film interference in a thin film laminate, but in the case of a light control sheet, reflected light R2 and R3 at the interfaces on both sides of the transparent conductive film 2a (R4 for the transparent conductive film 2b). And R5) are sufficient.
また、反射率の大きさは、界面を形成する両側の物質の屈折率差が大きくなるほど大きくなるが、調光シートについてみると、透明性基材、透明導電膜、調光層を構成する材料の屈折率差に比べ、透明性基材とその外側の空気（屈折率＝１．０）の屈折率差は大きく、反射率が他の界面よりも大きくなるという特徴がある。 In addition, the magnitude of the reflectance increases as the difference in refractive index between the substances on both sides forming the interface increases. However, in the light control sheet, the material constituting the transparent base material, the transparent conductive film, and the light control layer The refractive index difference between the transparent substrate and the outside air (refractive index = 1.0) is large, and the reflectance is higher than that of other interfaces.
以上のことを考慮すれば、界面（２）、（３）による反射については、透明導電膜２ａに反射防止効果を持たせて反射光Ｒ２、Ｒ３の干渉効果により反射率を低減させ、反射防止膜は界面（１）すなわち透明性基板１ａの外表面に設ければ十分であり、コスト、生産性的にも有利であるということを見出すに至る。界面（４）、（５）及び界面（６）につ
いても同じである。同様に、調光体の外表面については、図４（ｂ）のように、高強度透明性基板と空気の界面の反射光ＲＧ１、ＲＧ２による反射率を低減するように、高強度透明性基板１１ａ、１１ｂの外表面に反射防止膜を設ければよい。
In consideration of the above, the reflection by the interfaces (2) and (3) has the antireflection effect on the transparent conductive film 2a and the reflection effect is reduced by the interference effect of the reflected light R2 and R3, thereby preventing the reflection. It is sufficient that the film is provided on the interface (1), that is, the outer surface of the transparent substrate 1a, and it is found that it is advantageous in terms of cost and productivity. The same applies to the interfaces (4), (5) and the interface (6). Similarly, with respect to the outer surface of the light control body, as shown in FIG. 4B, the high-strength transparent substrate is used so as to reduce the reflectance of the reflected light RG1 and RG2 at the interface between the high-strength transparent substrate and the air. An antireflection film may be provided on the outer surfaces of 11a and 11b.
ここで反射防止条件について振り返る。図５（ａ）の単層の反射防止膜の場合、光が入射（出射）する側の媒質の屈折率をｎ０（ｎｓ）、反射防止膜の屈折率をｎ、膜厚をｄ、光の波長をλとすると、反射率ＲＡ１＝０となる反射防止条件は、次の（１）、（２）式である。
ｎ＝（ｎ０・ｎｓ）１／２ ・・・・（１）
ｄ＝（２ｍ＋１）・λ／４ｎ（ｍは０または正の整数） ・・・・（２）但し、式（１）、（２）を完全に満たさなくとも近い条件であれば相応に反射率ＲＡ１は低下し、反射防止効果を発現する。尚、正確には光は反射防止膜内で多重反射するが、図ではもっとも寄与が大きい１回反射光で代表させている。
Here, the antireflection conditions are reviewed. In the case of the single-layer antireflection film in FIG. 5A, the refractive index of the medium on which light enters (emits) is n0 (ns), the refractive index of the antireflection film is n, the film thickness is d, When the wavelength is λ, the antireflection conditions for the reflectance RA1 = 0 are the following equations (1) and (2).
n = (n0 · ns) 1/2 ... (1)
d = (2m + 1) · λ / 4n (m is 0 or a positive integer) (2) However, if the conditions are close without satisfying the expressions (1) and (2), the reflectance is correspondingly RA1 decreases and exhibits an antireflection effect. To be precise, the light is multiple-reflected in the antireflection film, but in the figure, it is represented by the one-time reflected light having the largest contribution.
図５（ｂ）の２層の反射防止膜の場合は、同様に上層（下層）の反射防止膜の屈折率をｎ１（ｎ２）、膜厚をｄ１（ｄ２）とすると、反射率ＲＡ２＝０となる反射防止条件は、次の（３）〜（５）式である。
ｎ２／ｎ１＝（ｎ０・ｎｓ）１／２ ・・・・（３）
ｄ１＝（２ｍ＋１）・λ／４ｎ１（ｍは０または正の整数） ・・・・（４）
ｄ２＝（２ｍ＋１）・λ／４ｎ２（ｍは０または正の整数） ・・・・（５）
但し、式（３）〜（５）を完全に満たさなくとも近い条件であれば相応に反射率ＲＡ２は低下し、反射防止効果を発現する。
In the case of the two-layer antireflection film in FIG. 5B, similarly, when the refractive index of the upper (lower) antireflection film is n1 (n2) and the film thickness is d1 (d2), the reflectance RA2 = 0. The antireflection conditions satisfying the following expressions (3) to (5).
n2 / n1 = (n0 · ns) 1/2 ... (3)
d1 = (2m + 1) · λ / 4n1 (m is 0 or a positive integer) (4)
d2 = (2m + 1) · λ / 4n2 (m is 0 or a positive integer) (5)
However, if the conditions are close without completely satisfying the expressions (3) to (5), the reflectivity RA2 is correspondingly lowered and an antireflection effect is exhibited.
式（１）はｎ０とｎｓを入れ換えても同じである。それゆえ、図４（ａ）における界面（１）〜（３）で反射率を低減する手法は、界面（４）〜（６）についても順序を逆にすればそのまま使えることが分かる。また、式（３）でｎ０とｎｓを入れ換えると、左辺のｎ１、ｎ２が逆になるが、これは入射側、出射側が逆になったので、上層、下層の反射防止膜の層順が逆になることを意味しており、従って界面（１）で用いる２層反射防止膜は、界面（６）についても層順を逆にするだけで使うことができる。 Formula (1) is the same even if n0 and ns are interchanged. Therefore, it can be seen that the method of reducing the reflectance at the interfaces (1) to (3) in FIG. 4A can be used as it is when the order of the interfaces (4) to (6) is reversed. In addition, when n0 and ns are interchanged in equation (3), n1 and n2 on the left side are reversed. However, since the incident side and the emission side are reversed, the layer order of the upper and lower antireflection films is reversed. Therefore, the two-layer antireflection film used at the interface (1) can be used only by reversing the layer order at the interface (6).
以上の知見に基づき、光学シミュレーションにより、透明性基材の外表面に設ける反射防止膜を検討した結果を以下に示す。ここで、透明性基材の材料は、もっとも一般的に用いられるポリエチレンテレフタレート（ＰＥＴ）とした。 Based on the above knowledge, the result of examining the antireflection film provided on the outer surface of the transparent substrate by optical simulation is shown below. Here, the most commonly used polyethylene terephthalate (PET) was used as the material for the transparent substrate.
調光シートについて留意すべき点は、低反射化（本発明では４％以下）としたい対象の波長は単一の波長ではなく、可視光域の波長ということである。しかしながら、前記の式（１）〜（５）を波長ごとに適用すると効率が悪くなる。そこで、本願ではまず、可視光域の両端に近い波長＝３８０ｎｍ、７８０ｎｍと、中央部に近い５８０ｎｍについて、共通する低反射化条件を探すこととした。 It should be noted about the light control sheet that the target wavelength to be reduced in reflection (4% or less in the present invention) is not a single wavelength but a wavelength in the visible light region. However, when the above formulas (1) to (5) are applied for each wavelength, the efficiency is deteriorated. Therefore, in the present application, first, a common low reflection condition is searched for wavelengths 380 nm and 780 nm close to both ends of the visible light region and 580 nm close to the center.
図６（ａ）は、透明性基材であるＰＥＴの表面に単層の反射防止膜を付けたときの、波長＝３８０ｎｍ（一点鎖線）、５８０ｎｍ（実線）、７８０ｎｍ（点線）における、反射防止膜の屈折率を横軸、膜厚を縦軸とする反射率＝４．０％の等高線である。ここで、斜線で示す領域は、前記の３波長において、共通して反射率が４％以下となる領域を示す。斜線領域の中心部に近づくほど反射率は低下する。図から分かるように、ほぼ屈折率＝１．２５、膜厚＝９０ｎｍであれば、可視光域の反射率はもっとも低下することが分かる。 FIG. 6A shows antireflection at wavelengths of 380 nm (one-dot chain line), 580 nm (solid line), and 780 nm (dotted line) when a single-layer antireflection film is attached to the surface of PET, which is a transparent substrate. Contour lines with reflectivity = 4.0% with the refractive index of the film as the horizontal axis and the film thickness as the vertical axis. Here, the shaded area indicates an area where the reflectance is 4% or less in common for the three wavelengths. The reflectance decreases as it approaches the center of the shaded area. As can be seen from the figure, when the refractive index is approximately 1.25 and the film thickness is 90 nm, the reflectance in the visible light region is most decreased.
そこで、波長＝３８０ｎｍ、４８０ｎｍ、５８０ｎｍ、６８０ｎｍ、７８０ｎｍにおけ
るＰＥＴの屈折率は、文献値から表１の値を用い、単層反射防止膜については屈折率＝１．２５と仮定し（透明性材料の波長ごとの屈折率の変化は一般に小さい）、波長間については、前記波長における値の補間により求める方法で、膜厚を変化させて波長＝３８０〜７８０ｎｍにおける分光反射率を計算した。図６（ｂ）は前記波長域でもっともバランスよく低反射となったとき（膜厚＝１００ｎｍ）の分光反射率であり、前記波長域で反射率は２％以下となっている。
Accordingly, the refractive index of PET at wavelengths = 380 nm, 480 nm, 580 nm, 680 nm, and 780 nm is assumed to be the refractive index = 1.25 for the single-layer antireflection film using the values in Table 1 from the literature values (transparent material) The change in the refractive index for each wavelength is generally small), and the spectral reflectance at the wavelength = 380 to 780 nm was calculated by changing the film thickness between the wavelengths by a method obtained by interpolation of the values at the wavelengths. FIG. 6B shows the spectral reflectance when the reflection is most balanced in the wavelength range (film thickness = 100 nm), and the reflectance is 2% or less in the wavelength range.
前記のようにＰＥＴ基材に対しては、屈折率＝１．２５付近の単車反射防止膜を使えばよいが、少なくとも無機材料では屈折率＝１．２５付近の実用的な材料は存在しない。屈折率の小さい材料としてはＣａＦ（フッ化カルシウム）やＭｇＦ（フッ化マグネシウム）があるが、最外表面に使用するには耐性、安定性に問題がある。実用的な材料でもっとも屈折率の小さい材料はＳｉＯ２（二酸化珪素）である。ＳｉＯ２の屈折率はＰＥＴ基材に対して式（１）の条件を満たさないが、相応の低反射化は期待できる。そこで、前記波長におけるＳｉＯ２の屈折率は文献値から表１の値を用い、前記と同じ方法で、膜厚を変化させて波長＝３８０〜７８０ｎｍにおける分光反射率を計算した結果の一例が図６（ｃ）である。このように、反射率＝０となる波長はないが、前記波長域でほぼ３％以下となっている。 As described above, a single-vehicle antireflection film having a refractive index of about 1.25 may be used for the PET substrate, but there is no practical material having a refractive index of about 1.25 for at least an inorganic material. As materials having a small refractive index, there are CaF (calcium fluoride) and MgF (magnesium fluoride), but there are problems in durability and stability when used on the outermost surface. A practical material having the lowest refractive index is SiO 2 (silicon dioxide). Although the refractive index of SiO 2 does not satisfy the condition of the formula (1) with respect to the PET base material, a corresponding low reflection can be expected. Therefore, an example of the result of calculating the spectral reflectance at the wavelength = 380 to 780 nm by changing the film thickness by the same method as described above for the refractive index of SiO 2 at the wavelength using the values shown in Table 1 from the literature values. 6 (c). As described above, there is no wavelength at which the reflectance = 0, but it is approximately 3% or less in the wavelength range.
次に、２層反射防止膜について検討した。２層反射防止膜についても上層反射防止膜は屈折率が小さいほど有利である。そこで上層反射防止膜をＳｉＯ２とし、膜厚は波長＝５８０ｎｍで、式（４）でｍ＝０の場合の９９．３ｎｍと仮定し、下層反射防止膜の屈折率を横軸、膜厚を縦軸として反射率＝４．０％の等高線を描くと図７（ａ）のようになる。ここで、斜線で示す領域は前記の３波長において、共通して反射率が４％以下となる領域を示す。斜線領域の中心部に近づくほど反射率は低下する。図から分かるように、斜線領域はＡ、Ｂ、Ｃの３領域に分かれているが、Ａは単層反射防止膜に近い領域であり、領域Ｂは式（５）でｍ＝０、領域Ｃはｍ＝１を反映した領域である。領域Ｂの膜厚は５０ｎｍ以下であり、安定した膜となるには薄過ぎる。そこで、領域Ｃの条件を検討することとした。 Next, the two-layer antireflection film was examined. Regarding the two-layer antireflection film, the upper antireflection film is more advantageous as the refractive index is smaller. Therefore, the upper antireflection film is assumed to be SiO 2 , the film thickness is assumed to be 99.3 nm when the wavelength is 580 nm and m = 0 in the formula (4), the refractive index of the lower antireflection film is plotted on the horizontal axis, If a contour line of reflectance = 4.0% is drawn on the vertical axis, it becomes as shown in FIG. Here, the shaded area indicates an area where the reflectance is 4% or less in common for the three wavelengths. The reflectance decreases as it approaches the center of the shaded area. As can be seen from the figure, the hatched area is divided into three areas A, B, and C, but A is an area close to a single-layer antireflection film, and area B is m = 0 in area (5) and area C Is an area reflecting m = 1. The film thickness of the region B is 50 nm or less, and is too thin to become a stable film. Therefore, the condition of region C was examined.
領域Ｃにおいては、波長＝３８０ｎｍ、５８０ｎｍ、７８０ｎｍにおける屈折率がほぼ１．７５〜２．０である必要がある。そのような膜で、実用的な膜として例えばＳｉＯＮ（酸窒化珪素）膜が挙げられる。ＳｉＯＮ膜の屈折率はＳｉＯ２膜とＳｉ３Ｎ４膜の複合膜として近似的に求めることができ、Ｓｉ３Ｎ４膜の屈折率は可視光域で２．０以上と大きいため、ＳｉＯ２膜とＳｉ３Ｎ４膜の比率を好適に求めることで、下層反射防止膜に適したＳｉＯＮ膜を見出すことができる。その結果、表１に示すように、ＳｉＯ２：Ｓｉ３Ｎ４＝３８：６２とすることで目標に近い屈折率となることが判明した。そこで、下層反射防止膜としてＳｉＯ２：Ｓｉ３Ｎ４＝３８：６２のＳｉＯＮ膜を用い、前記と同じ方法で、膜厚を変化させて波長＝３８０〜７８０ｎｍにおける分光反射率を計算した結果の一例が図７（ｂ）である。ここでは膜厚＝１１７．８ｎｍのときに、波長＝６６０ｎｍ付近で反射率＝０となり、他の波長でもほぼ３％以下となっている。 In the region C, the refractive index at wavelengths = 380 nm, 580 nm, and 780 nm needs to be approximately 1.75 to 2.0. As such a film, a practical film includes, for example, a SiON (silicon oxynitride) film. Since the refractive index of the SiON film can be determined approximately as a composite film of SiO 2 film and the Si 3 N 4 film, the refractive index of the Si 3 N 4 film is as large as 2.0 or more in the visible light region, SiO 2 By suitably determining the ratio of the film to the Si 3 N 4 film, it is possible to find a SiON film suitable for the lower antireflection film. As a result, as shown in Table 1, it was found that the refractive index was close to the target by setting SiO 2 : Si 3 N 4 = 38: 62. Therefore, using the SiON film of SiO 2 : Si 3 N 4 = 38: 62 as the lower-layer antireflection film, the spectral reflectance at the wavelength = 380 to 780 nm was calculated by changing the film thickness by the same method as described above. An example is shown in FIG. Here, when the film thickness is 117.8 nm, the reflectance becomes 0 near the wavelength = 660 nm, and is almost 3% or less at other wavelengths.
次に、透明導電膜の膜厚の好適化による、図４（ａ）における反射光Ｒ２、Ｒ３の干渉効果に依る反射率の低減を検討した結果について説明する。Ｒ２、Ｒ３の干渉効果に依る反射率は、入射側媒質をＰＥＴ、出射側媒質を液晶とし、透明導電膜を反射防止効果を調べる単層膜とみなして、上記の反射防止膜と同じ方法で計算することができる。計算に用いる屈折率は、液晶は調光層が透明状態であるので長軸方向の屈折率であり、透明導電膜であるＩＴＯの屈折率とともに表１の文献値を用いた。 Next, a description will be given of the result of studying the reduction of the reflectance due to the interference effect of the reflected light R2 and R3 in FIG. 4A by optimizing the film thickness of the transparent conductive film. The reflectance due to the interference effect of R2 and R3 is the same as that of the antireflection film described above, assuming that the incident side medium is PET, the output side medium is liquid crystal, and the transparent conductive film is a single layer film for examining the antireflection effect. Can be calculated. The refractive index used for the calculation is the refractive index in the major axis direction because the light control layer of the liquid crystal is in a transparent state, and the literature values in Table 1 are used together with the refractive index of ITO which is a transparent conductive film.
図８（ａ）、（ｂ）は、上記の反射防止膜と同じ方法で、ＩＴＯの膜厚を変化させて波
長＝３８０〜７８０ｎｍにおける分光反射率を計算した結果の例である。図８（ａ）は膜厚＝１３０ｎｍのとき、同（ｂ）は膜厚＝２１０ｎｍのときの分光反射率であり、このように膜厚を好適に選択することで、もっとも目的に適う分光反射率となる膜厚を選択することができる。
FIGS. 8A and 8B are examples of results of calculating the spectral reflectance at a wavelength = 380 to 780 nm by changing the film thickness of ITO by the same method as the above-described antireflection film. FIG. 8A shows the spectral reflectance when the film thickness = 130 nm, and FIG. 8B shows the spectral reflectance when the film thickness = 210 nm. By appropriately selecting the film thickness in this way, the most suitable spectral reflection is achieved. It is possible to select a film thickness to be a rate.
本発明の第２の実施形態である調光体で、透明性基材と高強度透明性基材の層間に透明性接着層を使用する場合は、上記の透明導電膜と同様の方法で、透明性接着層の両側の界面、すなわち透明性基材との界面及び高強度透明性基材との界面における、それぞれの反射光の干渉に依る反射率が３８０〜７８０ｎｍの波長域において４％以下となるように透明性接着層の膜厚を選択することができる。 In the case of using the transparent adhesive layer between the transparent substrate and the high-strength transparent substrate in the dimmer that is the second embodiment of the present invention, in the same manner as the transparent conductive film, 4% or less in the wavelength range of 380 to 780 nm where the reflectance due to interference of each reflected light at the interfaces on both sides of the transparent adhesive layer, that is, the interface with the transparent substrate and the interface with the high-strength transparent substrate The film thickness of the transparent adhesive layer can be selected so that
（反射防止層の材料と形成方法）
反射防止層としての単層の反射防止膜の屈折率は、既述のように屈折率が１．２５程度のものが好ましいが、実用的な無機材料としては難しい。ＳｉＯ２よりも屈折率が小さい有機材料では非晶性フッ素系ポリマーが候補となり、市販品としては、テフロン(登録商標）（商品名、デュポン社製）、サイトップ（商品名、旭硝子社製）などが挙げられる。その他、有機・無機ハイブリッド膜も候補となる。
(Material and forming method of antireflection layer)
As described above, the refractive index of the single-layer antireflection film as the antireflection layer is preferably about 1.25, but it is difficult as a practical inorganic material. Non-crystalline fluoropolymers are candidates for organic materials having a refractive index smaller than that of SiO 2 , and commercially available products include Teflon (registered trademark) (trade name, manufactured by DuPont), Cytop (trade name, manufactured by Asahi Glass) Etc. In addition, organic / inorganic hybrid films are also candidates.
無機材料であれば、薬品（洗浄液）耐性、安定性等を備えた単層の反射防止膜としては、ＳｉＯ２がもっとも屈折率が小さく好ましい。ＳｉＯ２は２層反射防止膜の低屈折率側としても好ましい。２層反射防止膜の高屈折率側としては、ＳｉＯＮ、Ｓｉ３Ｎ４、Ａｌ２Ｏ３、ＺｒＯ２、ＴｉＯ２などが好ましい。 In the case of an inorganic material, as a single-layer antireflection film having chemical (cleaning liquid) resistance, stability, etc., SiO 2 has the smallest refractive index and is preferable. SiO 2 is also preferable as the low refractive index side of the two-layer antireflection film. The high refractive index side of the two-layer antireflection film is preferably SiON, Si 3 N 4 , Al 2 O 3 , ZrO 2 , TiO 2 or the like.
反射防止層としての反射防止膜は公知の方法で形成することができる。ＳｉＯ２、ＳｉＯＮなどの無機膜の場合は、蒸着法、スパッタリング法などの減圧環境下でのドライコーティングで形成しても良く、成膜、乾燥後に機能を発現する液体を塗料として常圧環境下で印刷状に塗布するウェットコーティングにより形成しても良い。 The antireflection film as the antireflection layer can be formed by a known method. In the case of an inorganic film such as SiO 2 or SiON, it may be formed by dry coating in a reduced pressure environment such as a vapor deposition method or a sputtering method. A liquid that exhibits a function after film formation and drying is used as a paint in a normal pressure environment. Alternatively, it may be formed by wet coating applied in a printed form.
ドライコーティングは高精度で均一、高耐久性のある膜を得ることができる一方、減圧環境が必要でコスト高となる欠点がある。ウェットコーティングにより形成された反射防止膜は精度、耐久性でドライコーティングに劣るものの、減圧環境が不要で大幅に低コスト化した工程を実現できる他、塗料の設計次第でハードコート機能、防汚機能、易滑機能、筆記感向上機能などを複合させて付与することができる利点がある。反射防止膜の製造方法は、調光体の用途、形態、要求特性に応じて、適宜選択すればよい。 While dry coating can provide a highly accurate, uniform, and highly durable film, it requires a reduced pressure environment and is expensive. Anti-reflective coating formed by wet coating is inferior to dry coating with accuracy and durability, but it can realize a process that requires a reduced pressure environment and greatly reduces costs, and also has a hard coat function and antifouling function depending on the design of the paint. There is an advantage that a slippery function, a writing feeling improving function, and the like can be provided in combination. The production method of the antireflection film may be appropriately selected according to the use, form, and required characteristics of the light control member.
反射防止層として基材表面に微細構造を形成する方法としては、ウェットコーティング後の未硬化、半硬化塗膜に雄型版を押付けて形成するナノインプリントと呼ばれる手法で行うことができる。ナノインプリントによる反射防止層は、ナノメーターオーダーの十分に小さな微細構造であれば、反射防止性能、透過率向上性能で他方式に対し優位性があるものの微細構造を精密に転写することの困難さから高コストとなり、さらに構造上、強度が低く、表面の汚染に劣るという欠点がある。その他、いわゆる自己組織化膜を利用して微細構造を形成することもできる。 As a method of forming a fine structure on the substrate surface as the antireflection layer, a method called nanoimprinting, in which a male plate is pressed against an uncured and semi-cured coating film after wet coating, can be used. If the anti-reflection layer by nanoimprint has a sufficiently small microstructure on the order of nanometers, it is superior to other methods in anti-reflection performance and transmittance improvement performance, but it is difficult to accurately transfer the microstructure. There are drawbacks in that the cost is high, the structure is low in strength, and the surface contamination is poor. In addition, a fine structure can be formed using a so-called self-assembled film.
以下、本発明の実施例を説明するが、本発明は本実施例に限定されるものではない。 Examples of the present invention will be described below, but the present invention is not limited to these examples.
透明性基材とするＰＥＴフィルムよりも低屈折率な反射防止膜を形成するために下記成分を混合し、塗料を調製した。
・中空シリカ微粒子２０重量％のメチルイソブチルケトン）：１５．０重量部
・ペンタエリスリトールトリアクリレート（ＰＥＴＡ）：１．２重量部
・ジペンタエリスリトールヘキサアクリレート（ＤＰＨＡ）：０．４重量部
・イルガキュア１２７（商品名、チバ・スペシャルティ・ケミカルズ社製）：０．１重量部
・Ｘ−２２−１６４Ｅ（商品名、信越化学工業（株）製）：０．１５重量部
・メチルイソブチルケトン：８３．５重量部
In order to form an antireflection film having a lower refractive index than that of a PET film as a transparent substrate, the following components were mixed to prepare a coating material.
-Hollow silica fine particles 20% by weight methyl isobutyl ketone): 15.0 parts by weight-Pentaerythritol triacrylate (PETA): 1.2 parts by weight-Dipentaerythritol hexaacrylate (DPHA): 0.4 parts by weight-Irgacure 127 (Trade name, manufactured by Ciba Specialty Chemicals): 0.1 parts by weight • X-22-164E (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.): 0.15 parts by weight • methyl isobutyl ketone: 83.5 Parts by weight
透明導電膜（ＩＴＯ）付きの透明性基材である１対のＰＥＴフィルムの、透明導電膜の反対側の面（外表面）に、前記調整した塗料をワイヤーバーを用いて塗布し、乾燥、紫外線照射して硬化後膜厚が１０５ｎｍとなるような反射防止膜を形成した。得られた１対の反射防止膜付き導電性透明フィルム基材を用いて調光層を狭持し、特許第４３８７９３１号に準じる方法で、図２（ａ）に示す第１の実施形態の調光シートを作製した。 A pair of PET films, which are transparent substrates with a transparent conductive film (ITO), is coated on the opposite surface (outer surface) of the transparent conductive film using the wire bar, and dried. An antireflection film was formed such that the film thickness after curing by ultraviolet irradiation was 105 nm. The light control layer is sandwiched by using the obtained pair of conductive transparent film bases with an antireflection film, and the method of the first embodiment shown in FIG. 2A is performed by a method according to Japanese Patent No. 4387931. A light sheet was produced.
前記作製した調光シートを透明状態にセットし、ＪＩＳ Ｋ７１０５に準拠する方法で全光線透過率を測定したところ９２％であった。また、不透明状態に切り替えたときのヘイズ値をＪＩＳ Ｋ７１３６に準拠する方法で測定したところ９０％であった。 The produced light control sheet was set in a transparent state, and the total light transmittance was measured by a method based on JIS K7105. Moreover, it was 90% when the haze value when switched to the opaque state was measured by the method based on JISK7136.
＜比較例＞
反射防止膜を有しない以外は実施例１と同じ条件の調光シートを、特許第４３８７９３１号に準じる方法で作製し、透明状態にセットし、実施例と同じ方法で、全光線透過率を測定したところ８０％であった。また、不透明状態に切り替えたときのヘイズ値は９０％であった。
<Comparative example>
A light control sheet having the same conditions as in Example 1 except that it does not have an antireflection film was prepared by a method according to Japanese Patent No. 4387931, set in a transparent state, and the total light transmittance was measured by the same method as in Example As a result, it was 80%. Moreover, the haze value when switched to the opaque state was 90%.
上記のように、反射防止膜を備えた実施例の調光シートは、比較例の調光シートに比べ、１２％の全線透過率向上がみられるとともに、不透明時のヘイズ値に低下はなく、光散乱性と透明性を両立できることを確認した。 As described above, the light control sheet of the example provided with the antireflection film has 12% improvement in the total line transmittance as compared with the light control sheet of the comparative example, and there is no decrease in the haze value when opaque, It was confirmed that both light scattering and transparency can be achieved.
１ａ、１ｂ、５１ａ、５１ｂ・・・透明性基材
２ａ、２ｂ、５２ａ、５２ｂ・・・透明導電膜
３・・・・・・調光層
４・・・・・・高分子ネットワーク
５・・・・・・液晶分子
６・・・・・・ドメイン
７ａ、７ｂ、１７ａ、１７ｂ・・・反射防止膜
８ａ、８ｂ、１８ａ、１８ｂ・・・上層反射防止膜
９ａ、９ｂ、１９ａ、１９ｂ・・・下層反射防止膜
１１ａ、１１ｂ・・・・・高強度透明性基材
２１・・・・・入射光
２２・・・・・散乱光
２３・・・・・透過光
１０、２０・・・反射防止膜付き調光シート
３０、４０・・・反射防止膜付き調光体
５０・・・・・調光シート
1a, 1b, 51a, 51b ... transparent substrate 2a, 2b, 52a, 52b ... transparent conductive film 3 ... light control layer 4 ... polymer network 5 ... ··· Liquid crystal molecules 6 ··· Domains 7a, 7b, 17a and 17b · Antireflection films 8a, 8b, 18a and 18b · · · Upper antireflection films 9a, 9b, 19a and 19b Lower layer antireflection film 11a, 11b ... High-strength transparent substrate 21 ... Incident light 22 ... Scattered light 23 ... Transmitted light 10, 20 ... Reflection Light control sheet with anti-reflection film 30, 40... Light control body with anti-reflection film 50.
Claims (5)
前記高分子ネットワークにより形成されたドメインの径が４００〜８００ｎｍであり、
かつ少なくとも一方の面の前記透明性基材の外表面上に反射防止層を備え、
かつ前記反射防止層を含む前記透明性基材の外表面上の反射率が、３８０〜７８０ｎｍの波長域において４％以下であることを特徴とする調光シート。
ここでドメインの径とは、平面視でＸ方向（前記調光シートの長さ方向）の最大の長さとＹ方向（前記調光シートの幅方向）の最大の長さの平均とする。 A light control sheet comprising a light control layer using a polymer network type liquid crystal (PNLC), electrodes on both sides of the light control layer, electrodes made of a transparent conductive film, and a transparent substrate in this order,
The diameter of the domain formed by the polymer network is 400-800 nm,
And an antireflection layer is provided on the outer surface of the transparent substrate on at least one surface,
And the reflectance on the outer surface of the said transparent base material containing the said antireflection layer is 4% or less in the wavelength range of 380-780 nm, The light control sheet | seat characterized by the above-mentioned.
Here, the diameter of the domain is an average of the maximum length in the X direction (length direction of the light control sheet) and the maximum length in the Y direction (width direction of the light control sheet) in plan view.
前記高分子ネットワークにより形成されたドメインの径が４００〜８００ｎｍであり、
かつ前記高強度透明性基材の外表面上に反射防止層を備え、
かつ前記反射防止層を含む前記高強度透明性基材の外表面上の反射率が、３８０〜７８０ｎｍの波長域において４％以下であることを特徴とする調光体。
ここでドメインの径とは、平面視でＸ方向（前記調光シートの長さ方向）の最大の長さとＹ方向（前記調光シートの幅方向）の最大の長さの平均とする。 A light control layer using a polymer network type liquid crystal (PNLC), electrodes on both sides of the light control layer, electrodes made of a transparent conductive film, and a transparent base material on at least one surface of the light control sheet provided in this order, It is a dimmer with a high-strength transparent substrate bonded,
The diameter of the domain formed by the polymer network is 400-800 nm,
And an antireflection layer on the outer surface of the high-strength transparent substrate,
And the light control body characterized by the reflectance on the outer surface of the said high intensity | strength transparent base material containing the said antireflection layer being 4% or less in the wavelength range of 380-780 nm.
Here, the diameter of the domain is an average of the maximum length in the X direction (length direction of the light control sheet) and the maximum length in the Y direction (width direction of the light control sheet) in plan view.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017021259A JP2018128566A (en) | 2017-02-08 | 2017-02-08 | Dimming sheet and dimming body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017021259A JP2018128566A (en) | 2017-02-08 | 2017-02-08 | Dimming sheet and dimming body |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2018128566A true JP2018128566A (en) | 2018-08-16 |
Family
ID=63172848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2017021259A Pending JP2018128566A (en) | 2017-02-08 | 2017-02-08 | Dimming sheet and dimming body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2018128566A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2020038264A (en) * | 2018-09-03 | 2020-03-12 | 凸版印刷株式会社 | Dimmer unit and dimmer unit with transparent plate |
| JP2020154086A (en) * | 2019-03-19 | 2020-09-24 | 凸版印刷株式会社 | Dimming sheet, dimming device, and management method of dimming sheet |
| JP7434816B2 (en) | 2019-11-11 | 2024-02-21 | Ｔｏｐｐａｎホールディングス株式会社 | lighting equipment |
| WO2024058275A1 (en) * | 2022-09-16 | 2024-03-21 | Ｔｏｐｐａｎホールディングス株式会社 | Light control sheet |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0915657A (en) * | 1995-06-26 | 1997-01-17 | Nippondenso Co Ltd | Liquid crystal optical shutter |
| JP2008209877A (en) * | 2007-01-31 | 2008-09-11 | Fujifilm Corp | Optical multilayer film and image display device |
| JP2011026526A (en) * | 2009-07-29 | 2011-02-10 | Dic Corp | Polymer dispersion-type liquid crystal composition, and polymer dispersion-type liquid crystal element using the same |
| CN102460283A (en) * | 2009-06-23 | 2012-05-16 | 夏普株式会社 | Display device and multilayer substrate |
| JP2017026920A (en) * | 2015-07-25 | 2017-02-02 | 有限会社きこりたち | Vehicle window and vehicle |
-
2017
- 2017-02-08 JP JP2017021259A patent/JP2018128566A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0915657A (en) * | 1995-06-26 | 1997-01-17 | Nippondenso Co Ltd | Liquid crystal optical shutter |
| JP2008209877A (en) * | 2007-01-31 | 2008-09-11 | Fujifilm Corp | Optical multilayer film and image display device |
| CN102460283A (en) * | 2009-06-23 | 2012-05-16 | 夏普株式会社 | Display device and multilayer substrate |
| JP2011026526A (en) * | 2009-07-29 | 2011-02-10 | Dic Corp | Polymer dispersion-type liquid crystal composition, and polymer dispersion-type liquid crystal element using the same |
| JP2017026920A (en) * | 2015-07-25 | 2017-02-02 | 有限会社きこりたち | Vehicle window and vehicle |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2020038264A (en) * | 2018-09-03 | 2020-03-12 | 凸版印刷株式会社 | Dimmer unit and dimmer unit with transparent plate |
| JP2020154086A (en) * | 2019-03-19 | 2020-09-24 | 凸版印刷株式会社 | Dimming sheet, dimming device, and management method of dimming sheet |
| WO2020189715A1 (en) * | 2019-03-19 | 2020-09-24 | 凸版印刷株式会社 | Dimming sheet, dimming device, and method for managing dimming sheet |
| US11650447B2 (en) | 2019-03-19 | 2023-05-16 | Toppan Printing Co., Ltd. | Light control sheet, light control device and method of controlling the light control sheet |
| JP7434816B2 (en) | 2019-11-11 | 2024-02-21 | Ｔｏｐｐａｎホールディングス株式会社 | lighting equipment |
| WO2024058275A1 (en) * | 2022-09-16 | 2024-03-21 | Ｔｏｐｐａｎホールディングス株式会社 | Light control sheet |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6070195B2 (en) | Antireflection film, method for producing antireflection film, polarizing plate and image display device | |
| JP2018128566A (en) | Dimming sheet and dimming body | |
| KR20140137318A (en) | Double sided transparent conductive film and touch panel | |
| JP6956909B2 (en) | Optical laminates and articles | |
| WO2002055612A1 (en) | Coating composition, coating film thereof, antireflection coating, antireflection film, image display, and intermediate product | |
| JP2007121993A (en) | Antireflection laminate and method for producing the same | |
| TWI605267B (en) | Antireflection film and its manufacturing method | |
| WO2016103685A1 (en) | Optical laminate, polarizing plate, and display device | |
| JP2019012294A (en) | Antireflection film and manufacturing method thereof | |
| JP2002277609A (en) | Antireflection coating, antireflection film, image display and method for producing those | |
| JP2004272198A (en) | Antireflective stack | |
| JP2007178999A (en) | Antireflection film and filter for display | |
| JP5865412B2 (en) | Infrared shielding film for windows | |
| JP2002296406A (en) | Antireflection base material with few reflection interference color | |
| JP2003255106A (en) | Antireflection film | |
| JP2008276205A (en) | Optical layered product | |
| JP6406248B2 (en) | Infrared shielding film manufacturing method | |
| WO2019163791A1 (en) | Transparent conductive laminate | |
| JP2006267556A (en) | Optical layered body | |
| WO2014185386A1 (en) | Production method for infrared shielding film | |
| JP2009042554A (en) | Optical laminated body, polarizing plate and image forming apparatus | |
| JP2018075783A (en) | Laminate | |
| JP2000258613A (en) | Antidazzle sheet, display device and production of antidazzle sheet | |
| JP2015098119A (en) | Window sticking film | |
| WO2023162999A1 (en) | Self-luminous display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20200123 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20201104 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20201223 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20210518 |