JP4271842B2 - Antiglare antireflection film, polarizing plate, and liquid crystal display device - Google Patents

Description

【００６６】
次に、実施例３のフィルムを用いて防眩性反射防止偏光板を作成した。この偏光板を用いて反射防止層を最表層に配置した液晶表示装置を作成したところ、外光の映り込みがないために優れたコントラストが得られ、防眩性により反射像が目立たず優れた視認性を有し、指紋付も良好であった。
【００６７】
（トリアセチルセルロースドープＡの調製）
トリアセチルセルロース１７．４質量部、トリフェニルフォスフェート２．６質量部、ジクロロメタン６６質量部、メタノール５．８質量部、ノルマルブタノール８．２質量部からなる原料を攪拌しながら混合して溶解し、トリアセチルセルロースドープＡを調製した。
【００６８】
（トリアセチルセルロースドープＢの調製）
トリアセチルセルロース２４質量部、トリフェニルフォスフェート４質量部、ジクロロメタン６６質量部、メタノール６質量部からなる原料を攪拌しながら混合して溶解し、トリアセチルセルロースドープＢを調製した。
【００６９】
（トリアセチルセルロースドープＣの調製）
トリアセチルセルロース２０質量部、酢酸メチル４８質量部、シクロヘキサノン２０質量部、メタノール５質量部、エタノール５質量部、トリフェニルフォスフェート／ビフェニルジフェニルフォスフェート(1/2)２質量部、シリカ（粒径２０ｎｍ）０．１質量部、２，４−ビス−（ｎ−オクチルチオ）−６−（４−ヒドロキシ−３，５−ジ−tert−ブチルアニリノ）−１，３，５−トリアジン０．２質量部を添加、攪拌して得られた不均一なゲル状溶液を、−７０℃にて６時間冷却した後、５０℃に加温し攪拌してドープＣを調製した。
【００７０】
（トリアセチルセルロースドープＤの調製）
上記トリアセチルセルロースドープＣと同様にして得られた不均一なゲル状溶液を、ステンレス製密閉容器にて１ＭＰa、１８０℃で５分間加熱した後、５０℃の水浴中に容器ごと投入し冷却し、トリアセチルセルロースドープＤを調製した。
【００７１】
（防眩層用塗布液Ａ′の調製）
ジペンタエリスリトールペンタアクリレートとジペンタエリスリトールヘキサアクリレートの混合物（ＤＰＨＡ、日本化薬(株)製）９１ｇ、酸化ジルコニウム分散物含有ハードコート塗布液（デソライトＺ−７４０１、ＪＳＲ(株)製）２１８ｇを、５２ｇのメチルエチルケトン／シクロヘキサノン＝５４／４６質量％の混合溶媒に溶解した。得られた溶液に、光重合開始剤（イルガキュア９０７、チバガイギー社製）１０ｇを加えた。この溶液を塗布、紫外線硬化して得られた塗膜の屈折率は１．６１であった。
さらにこの溶液に平均粒径２μｍの架橋ポリスチレン粒子（商品名：ＳＸ−２００Ｈ、綜研化学(株)製）２０ｇを８０ｇのメチルエチルケトン／シクロヘキサノン＝５４／４６質量％の混合溶媒に高速ディスパにて５０００rpmで１時間攪拌分散した分散液２９ｇを添加、攪拌した後、孔径３０μｍのポリプロピレン製フィルターでろ過して防眩層の塗布液Ａを調製した。
【００７２】
（防眩層用塗布液Ｂ′の調製）
ジペンタエリスリトールペンタアクリレートとジペンタエリスリトールヘキサアクリレートの混合物（ＤＰＨＡ、日本化薬(株) 製）２５０ｇを、４３９ｇのメチルエチルケトン／シクロヘキサノン＝５０／５０質量％の混合溶媒に溶解した。得られた溶液に、光重合開始剤（イルガキュア９０７、チバガイギー社製）５．０ｇおよび光増感剤（カヤキュアーＤＥＴＸ、日本化薬(株）製）３．０ｇを４９ｇのメチルエチルケトンに溶解した溶液を加えた。この溶液を塗布、紫外線硬化して得られた塗膜の屈折率は１．５１であった。
さらにこの溶液に平均粒径２μｍの架橋ポリスチレン粒子（商品名：ＳＸ−２００Ｈ、綜研化学(株)製）１０ｇを添加して、高速ディスパにて５０００rpmで１時間攪拌、分散した後、孔径３０μｍのポリプロピレン製フィルターでろ過して防眩層の塗布液Ｂ′を調製した。
【００７３】
（ハードコート層用塗布液Ｃ′の調製）
紫外線硬化性ハードコート組成物（デソライトＺ−７５２６、７２質量％、ＪＳＲ(株) 製）２５０ｇを６２ｇのメチルエチルケトンおよび８８ｇのシクロヘキサノンに溶解した溶液を加えた。この溶液を塗布、紫外線硬化して得られた塗膜の屈折率は１．５３であった。
さらにこの溶液を孔径３０μｍのポリプロピレン製フィルターでろ過してハードコート層の塗布液Ｃ′を調製した。
【００７４】
（低屈折率層用塗布液Ｄ′の調製）
屈折率１．４２であり、熱架橋性含フッ素ポリマーの６質量％のメチルエチルケトン溶液（ＪＮ−７２２８、ＪＳＲ(株)製）９３ｇにＭＥＫ−ＳＴ（平均粒径１０〜２０ｎｍ、固形分濃度３０質量％のＳｉＯ₂ゾルのメチルエチルケトン分散物、日産化学(株)製）８ｇ、メチルエチルケトン９４ｇ、およびシクロヘキサノン６ｇを添加、攪拌の後、孔径１μｍのポリプロピレン製フィルター（ＰＰＥ−０１）でろ過して、低屈折率層の塗布液Ｄ′を調製した。
【００７５】
［実施例４］
特開平１１−２５４５９４等に従って、３層共流延ダイを用い、ドープＢの両側にドープＡを共流延するように配置して金属ドラム上に同時に吐出させて重層流延した後、流延膜をドラムから剥ぎ取り、乾燥して、ドラム両面から１０μｍ、６０μｍ、１０μｍの３層共流延トリアセチルセルロースフィルムを作成した。このフィルムには、各層間に明確な界面は形成されていなかった。
上記のトリアセチルセルロースフィルムに、上記のハードコート層用塗布液Ｃ′をバーコーターを用いて塗布し、１２０℃で５分間乾燥の後、１６０Ｗ／ｃｍの空冷メタルハライドランプ（アイグラフィックス(株)製）を用いて、照度４００ｍＷ／ｃｍ²、照射量３００ｍＪ／ｃｍ²の紫外線を照射して塗布層を硬化させ、厚さ２．５μｍのハードコート層を形成した。
その上に、上記防眩層用塗布液Ａ′をバーコーターを用いて塗布し、窒素パージにより雰囲気の酸素濃度を６％にした以外は上記ハードコート層と同条件にて乾燥、紫外線硬化して、厚さ約１．５μｍの防眩層を形成した。
その上に、上記低屈折率層用塗布液Ｄ′をバーコーターを用いて塗布し、８０℃の乾燥の後、さらに１２０℃で８分間熱架橋し、厚さ０．０９６μｍの低屈折率層を形成した。
【００７６】
［実施例５］
特開平７−１１０５５に従い、上記トリアセチルセルロースドープＣを単層ドラム流延し、厚み８０μｍのトリアセチルセルロースフィルムを作成し、その上に、実施例４と同様にしてハードコート層、防眩層、および低屈折率層を形成した。
【００７７】
［実施例６］
特開平７−１１０５５に従い、上記トリアセチルセルロースドープＤを単層ドラム流延し、厚み８０μｍのトリアセチルセルロースフィルムを作成し、その上に、実施例４と同様にしてハードコート層、防眩層、および低屈折率層を形成した。
【００７８】
［比較例２］
８０μｍの厚さのトリアセチルセルロースフィルム（ＴＡＣ−ＴＤ８０Ｕ、富士写真フィルム(株)製）に、上記のハードコート層用塗布液Ｄ′をバーコーターを用いて塗布し、１２０℃の乾燥の後、１６０Ｗ／ｃｍの空冷メタルハライドランプ（アイグラフィックス(株)製）を用いて、照度４００ｍＷ／ｃｍ²、照射量３００ｍＪ／ｃｍ²の紫外線を照射して塗布層を硬化させ、厚さ４μｍのハードコート層を形成した。
その上に、防眩層用塗布液Ｂ′をバーコーターを用いて塗布し、上記ハードコート層と同条件にて乾燥、紫外線硬化して、厚さ約１．５μｍ、屈折率１．５１の防眩層を形成した。
その上に、上記低屈折率層用塗布液Ｄ′をバーコーターを用いて塗布し、８０℃の乾燥の後、さらに１２０℃で１０分間熱架橋し、厚さ０．０９６μｍの低屈折率層を形成した。
【００７９】
表２に実施例４〜６および比較例２の結果を示す。評価法は前述の通りである。
表２に示された結果から以下のことが明らかである。
実施例４、５、６のいずれの防眩性反射防止フィルムも、防眩性、反射防止性に優れ、且つ色味が弱く、また鉛筆硬度、指紋付着性、動摩擦係数等の膜物性を反映する評価の結果も良好であった。
一方、比較例２は、防眩層の屈折率が低いため、十分な反射防止性が得られなかった。
【００８０】
【表２】

【００８１】
次に、実施例６のフィルムを用いて防眩性反射防止偏光板を作成した。この偏光板を用いて反射防止層を最表層に配置した液晶表示装置を作成したところ、外光の映り込みがないために優れたコントラストが得られ、防眩性により反射像が目立たず優れた視認性を有し、指紋付きも良好であった。
【００８２】
【発明の効果】
本発明の防眩性反射防止フィルムは、支持体上に防眩性層と低屈折率層を形成するだけで、簡便かつ安価に製造され、しかも十分な反射防止性能と耐傷性、さらには防汚性を有し、加えて色味、色むらが少ない。
さらに本発明の偏光板および液晶表示装置は、外光の映り込みが十分に防止されているため優れたコントラストが得られ、しかも防汚性、耐傷性に優れている。
【図面の簡単な説明】
【図１】防眩性反射防止フィルムの層構成を示す断面模式図である。
【符号の説明】
１ 防眩性反射防止フィルム
２ トリアセチルセルロースからなる透明支持体
３ ハードコート層
４ 防眩層
５ 低屈折率層
６ 樹脂マット粒子[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antireflection film having antiglare properties, a polarizing plate, and a liquid crystal display device using the same.
[0002]
[Prior art]
Anti-reflection films generally prevent contrast degradation and image reflection due to reflection of external light in image display devices such as cathode ray tube display devices (CRT), plasma display panels (PDP), and liquid crystal display devices (LCD). In order to do this, it is placed on the outermost surface of the display that reduces the reflectivity using the principle of optical interference.
[0003]
However, in the antireflection film having only the hard coat layer and the low refractive index layer on the transparent support, the low refractive index layer must be sufficiently lowered in order to reduce the reflectance. For example, in order to reduce the average reflectance in the range of 450 nm to 650 nm with an antireflective film having triacetylcellulose as a support and a UV-coated film of dipentaerythritol hexaacrylate as a hard coat layer to 1.6% or less, The refractive index must be 1.40 or less.
Examples of materials having a refractive index of 1.40 or less include fluorine-containing compounds such as magnesium fluoride and calcium fluoride for inorganic materials, and fluorine-containing compounds having a high fluorine content for organic materials. These fluorine-containing compounds have cohesive strength. Therefore, the film placed on the outermost surface of the display was insufficient in scratch resistance. Therefore, in order to have sufficient scratch resistance, a compound having a refractive index of 1.43 or more is required.
[0004]
Japanese Patent Application Laid-Open No. 7-287102 describes that the reflectance is reduced by increasing the refractive index of the hard coat layer. However, since such a high refractive index hard coat layer has a large difference in refractive index from the support, color unevenness of the film occurs, and the wavelength dependence of the reflectance also greatly increases.
[0005]
Japanese Patent Application Laid-Open No. 7-333404 describes an antiglare antireflection film excellent in gas barrier properties, antiglare properties and antireflection properties. However, since a silicon oxide film by a CVD method is essential, a coating liquid is used. It is inferior in productivity as compared with the wet coating method in which a film is formed by coating. Furthermore, the antireflection property of the antiglare antireflection film thus obtained is not satisfactory.
[0006]
[Problems to be solved by the invention]
The object of the present invention is to produce an antiglare layer and a low refractive index layer on a support, which can be easily and inexpensively manufactured, and has sufficient antireflection performance, scratch resistance, and antifouling properties. In addition, it is to provide an antiglare antireflection film having little color unevenness.
Another object of the present invention is to provide a polarizing plate and a liquid crystal display device that are sufficiently prevented from reflecting external light and that have excellent antifouling properties and scratch resistance.
[0007]
[Means for Solving the Problems]
According to the present invention, an antiglare antireflection film, a polarizing plate and a liquid crystal display device having the following constitution are provided, and the above object is achieved.
1. On the transparent support, an antiglare layer and at least one low refractive index layer are provided in this order, and the antiglare layer is composed of mat particles having a particle diameter of 1 to 10 μm and metal oxide having a particle diameter of 100 nm or less. Have fine particles, The addition amount of the metal oxide fine particles is 10 to 90% of the total mass of the antiglare layer, The average value of the specular reflectance in the wavelength region from 450 nm to 650 nm at 5 ° incidence is 1.2% or less, and the average value in the wavelength region from 450 nm to 650 nm of the integrated reflectance at 5 ° incidence is 2 or less. .Anti-glare antireflection film characterized by being 5% or less.
2. 2. The antiglare antireflection film according to 1, which has a smooth hard coat layer between the transparent support and the antiglare layer.
3. Triacetyl produced by casting a triacetyl cellulose dope prepared by dissolving a triacetyl cellulose in a solvent in a single-layer casting or multi-layer co-casting. 3. The antiglare antireflection film as described in 1 or 2, which is a cellulose film.
4). 4. The triacetylcellulose dope prepared by dissolving triacetylcellulose in a solvent substantially free of dichloromethane by a low temperature dissolution method or a high temperature dissolution method. Antiglare antireflection film.
5. CIE standard light source D65 in the wavelength range of 380 nm to 780 nm has a color of specularly reflected light with respect to 5 ° incident light, and L *, a *, and b * values of CIE 1976 L * a * b * color space are L * ≦ 10, 5. The antiglare antireflection film according to any one of 1 to 4, which has a color that satisfies 0 ≦ a * ≦ 2 and −5 ≦ b * ≦ 2.
6). The antiglare antireflection film according to any one of 1 to 5, wherein the haze value is in the range of 5 to 15%.
7). The anti-glare antireflection film according to any one of 1 to 6, wherein the low refractive index layer is made of a cured product of a thermosetting or ionizing radiation curable fluorine-containing resin.
8). 7 in which the dynamic friction coefficient of the low refractive index layer made of the cured product of the fluororesin is in the range of 0.03 to 0.15, and the contact angle with water is in the range of 90 to 120 degrees. The antiglare antireflection film as described.
9. A polarizing plate, wherein the antiglare antireflection film according to any one of 9.1 to 8 is used for at least one of two protective films of a polarizing layer in a polarizing plate.
10. An antiglare antireflection film according to any one of 10.1 to 8, or an antireflection layer of the antiglare antireflection polarizing plate according to 9, which is used as an outermost layer of a display. .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
First, the basic structure of the antiglare antireflection film of the present invention will be described with reference to the drawings.
The embodiment shown in FIG. 1 is an example of the antiglare antireflection film of the present invention. In this case, the antiglare antireflection film 1 is obtained by casting a triacetyl cellulose dope prepared by dissolving triacetyl cellulose in a solvent by a single layer casting method or a multi-layer co-casting method. The transparent support 2, the hard coat layer 3, the anti-glare layer 4, and the low refractive index layer 5 are formed in this order. Resin mat particles 6 are dispersed in the antiglare layer 4.
[0009]
In the antiglare antireflection film of the present invention, the average value of the specular reflectance at 5 ° incidence in the wavelength region from 450 nm to 650 nm is 1.2% or less, preferably 1.1% or less.
Moreover, it is preferable that the average value in the wavelength region from 450 nm to 650 nm of the integrated reflectance at 5 degrees incidence is 2.5% or less, and more preferably 2.3% or less.
[0010]
The specular reflectance at 5 degrees incidence and the 5 degrees incidence will be described.
The specular reflectivity at 5 degrees incidence is a ratio of the intensity of light reflected at -5 degrees normal to the incident light from the normal direction +5 degrees of the sample, and is a measure of reflection due to specular reflection of the background. When applied to an antiglare antireflection film, the intensity of light reflected at −5 degrees in the normal direction is reduced by the amount of scattered light caused by surface irregularities provided for imparting antiglare properties. Therefore, specular reflectance can be said to be a measurement method that reflects the contribution of both antiglare and antireflection properties.
On the other hand, the integrated reflectance at 5 degrees incidence is the ratio of the integrated value of the intensity of light reflected in all directions with respect to the light incident from the normal direction of the sample +5 degrees. When applied to an anti-glare antireflection film, since the reflection light does not decrease due to the anti-glare property, measurement reflecting only the antireflection property is possible.
Therefore, by setting the average values of both of the above reflectances in the wavelength region from 450 nm to 650 nm to 1.2% or less (specular reflectance) and 2.5% or less (integral reflectance), respectively, antiglare And antireflection properties can be satisfied at the same time.
[0011]
If the average value of the specular reflectance of the antiglare antireflection film in the wavelength region from 450 nm to 650 nm exceeds 5%, the background reflection will be a concern. Visibility when applied is reduced.
On the other hand, if the average value in the wavelength region from 450 nm to 650 nm of the integrated reflectance at 5 ° incidence of the antiglare antireflection film exceeds 2.5%, the contrast improvement effect of the display device is reduced and the antiglare property is reduced. The display screen is whitened by the scattered light due to surface irregularities for application, and the display quality of the display device is lowered.
[0012]
In the antiglare antireflection film of the present invention, the color of specular reflection light with respect to incident light of 5 degrees from the CIE standard light source D65 is quantified by the L *, a *, and b * values of the CIE 1976 L * a * b * color space. Are preferably designed to fall within the ranges of L * ≦ 10, 0 ≦ a * ≦ 2, and −5 ≦ b * ≦ 2, respectively. The color of the regular reflection light that satisfies this is a neutral color.
The color of the specularly reflected light with respect to 5 ° incident light of the CIE standard light source D65 is obtained by calculating the product of the measured value of the specular reflectance in the wavelength range of 380 nm to 780 nm at 5 ° incident and the spectral distribution at each wavelength of the light source D65 The obtained spectral reflection spectrum can be quantified by calculating the L * value, a * value, and b * value of the CIE1976 L * a * b * color space, respectively.
When the L * value is larger than 10, the antireflection property is not sufficient. If the a * value is larger than 2, the red uneven color of the reflected light is strong, and if it is less than 0, the green color is strong. Further, when the b * value is less than −5, the bluish color is strong, and when it is larger than 2, the yellow color is strong, which is not preferable.
[0013]
Anti-glare anti-reflection film with such neutral color reflected light and low reflectivity optimizes the balance between the refractive index of the low refractive index layer and the refractive index of the binder material of the anti-glare layer It is obtained by doing.
In general, an antireflection film using an optical thin film formed by vapor deposition or sputtering of three or more layers can reduce the average value of the specular reflectance to 0.3% or less, and thus the L * value can also be reduced to 3 or less. Is 10 or more and the b * value is less than −10, and the color of the reflected light is very strong. However, the antiglare antireflection film of the present invention is in terms of the color of the reflected light. Greatly improved.
[0014]
The antiglare antireflection film of the present invention preferably has a haze value of 5 to 15%, more preferably 7 to 13. The antiglare property and the haze value do not necessarily correspond linearly, but if the haze value is less than 5%, an antiglare film having sufficient antiglare property cannot be obtained. On the other hand, if the haze value is larger than 15%, scattering on the surface and inside is too strong, which causes problems such as a decrease in image sharpness and whitening, which is not preferable.
[0015]
Each layer constituting the antiglare antireflection film of the present invention having such characteristics will be described below.
The antiglare antireflection film of the present invention has an antiglare layer on a transparent support, and further has at least one low refractive index layer on the transparent support, and if necessary, a lower layer of the antiglare layer. A smooth hard coat layer can be provided.
[0016]
As the transparent support of the antiglare antireflection film of the present invention, it is preferable to use a plastic film. Polymers that form plastic films include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate), polystyrene, polyolefin, arton (trade name, JSR Corporation) ), Substance name: norbornene-based polyolefin), Zeonex (trade name, manufactured by Nippon Zeon Co., Ltd., substance name: norbornene-based polyolefin), and the like. Of these, triacetyl cellulose, polyethylene terephthalate, polyethylene naphthalate, arton, and ZEONEX are preferable, and triacetyl cellulose is particularly preferable. The refractive index of triacetyl cellulose is 1.48.
[0017]
As the transparent support of the antiglare antireflection film of the present invention, a triacetylcellulose dope prepared by dissolving triacetylcellulose in a solvent is casted in either a single layer casting or a multiple layer co-casting. It is preferable to use a triacetyl cellulose film prepared by casting by the method. In particular, from the viewpoint of environmental conservation, a triacetyl cellulose film prepared using a triacetyl cellulose dope prepared by dissolving triacetyl cellulose in a solvent substantially free of dichloromethane by a low temperature dissolution method or a high temperature dissolution method. Is preferred.
A single-layer triacetyl cellulose is prepared by drum casting or band casting disclosed in Japanese Patent Laid-Open No. 7-11055, etc. of the published patent publication. JP-A-61-94725, JP-B-62-43846, and the like. It is created by the so-called co-casting method. That is, the raw material flakes are solvents such as halogenated hydrocarbons (dichloromethane, alcohols (methanol, ethanol, butanol, etc.), esters (methyl formate, methyl acetate, etc.), ethers (dioxane, dioxolane, diethyl ether, etc.), etc. A solution (called a dope) with various additives such as a plasticizer, an ultraviolet absorber, an anti-degradation agent, a slipping agent, and a peeling accelerator is added to the horizontal endless as necessary. When casting by a dope supply means (called a die) on a support composed of a metal belt or a rotating drum, a single dope is cast in a single layer if it is a single layer, and a high concentration in the case of multiple layers. A low-concentration dope is co-cast on both sides of the cellulose ester dope, and the film which has been dried to some extent on the support and given rigidity is peeled off from the support, The conveying means is passed through the drying section is a method consisting of removing the solvent.
[0018]
A typical solvent for dissolving triacetylcellulose as described above is dichloromethane. However, technically, halogenated hydrocarbons such as dichloromethane can be used without problems, but from the viewpoint of the global environment and working environment, the solvent preferably does not substantially contain halogenated hydrocarbons such as dichloromethane. “Substantially free” means that the proportion of halogenated hydrocarbon in the organic solvent is less than 5% by mass (preferably less than 2% by mass). In preparing a triacetyl cellulose dope using a solvent substantially free of dichloromethane or the like, a special dissolution method as described later is essential.
[0019]
The first dissolution method is called a cooling dissolution method and will be described below. First, triacetyl cellulose is gradually added while stirring at a temperature around room temperature (-10 to 40 ° C.). The mixture is then cooled to -100 to -10 ° C (preferably -80 to -10 ° C, more preferably -50 to -20 ° C, most preferably -50 to -30 ° C). The cooling can be performed, for example, in a dry ice / methanol bath (−75 ° C.) or a cooled diethylene glycol solution (−30 to −20 ° C.). When cooled in this manner, the mixture of triacetyl cellulose and solvent solidifies. Furthermore, when this is heated to 0 to 200 ° C. (preferably 0 to 150 ° C., more preferably 0 to 120 ° C., most preferably 0 to 50 ° C.), a solution in which triacetyl cellulose flows in the solvent is obtained. The temperature may be increased by simply leaving it at room temperature or in a warm bath.
[0020]
The second method is called a high temperature melting method and will be described below. First, triacetyl cellulose is gradually added to a solvent with stirring at a temperature around room temperature (-10 to 40 ° C.). The triacetyl cellulose solution of the present invention is preferably swollen beforehand by adding triacetyl cellulose to a mixed solvent containing various solvents. In this method, the dissolution concentration of triacetyl cellulose is preferably 30% by mass or less, but is preferably as high as possible from the viewpoint of drying efficiency during film formation. Next, the organic solvent mixed solution is heated to 70 to 240 ° C. under a pressure of 0.2 MPa to 30 MPa (preferably 80 to 220 ° C., more preferably 100 to 200 ° C., most preferably 100 to 190 ° C.). Next, since these heated solutions cannot be applied as they are, it is necessary to cool them below the lowest boiling point of the used solution. In that case, it is common to cool to -10-50 degreeC and to return to a normal pressure. For cooling, the high-pressure and high-temperature vessel or line containing the triacetylcellulose solution may be left at room temperature, and more preferably, the apparatus may be cooled using a coolant such as cooling water.
[0021]
As a protective film for protecting the polarizing layer of the polarizing plate of the liquid crystal display device, since triacetyl cellulose is usually used, when the transparent support of the antiglare antireflection film is a triacetyl cellulose film as described above, The antiglare antireflection film can be used as it is for the protective film, which is preferable. In this case, the antiglare antireflection film can be disposed as a protective film on the outermost surface of the display of the liquid crystal display device by means such as providing an adhesive layer on one side of the antiglare antireflection film.
[0022]
In the antiglare layer, it is preferable that mat particles having a particle diameter of 1 to 10 μm and metal oxide fine particles having a particle diameter of 100 nm or less are dispersed in a binder polymer.
The component excluding the matte particles forming the antiglare layer, that is, the refractive index of the dispersion in which the binder polymer or the fine particle component of the metal oxide having a particle size of 100 nm or less is dispersed is 1.57 to 2.00. Is more preferable, and a high refractive index of 1.60 to 1.80 is more preferable. If this value is too small, the antireflection performance will be small, and if it is too large, the color may be too large.
[0023]
Such an anti-glare layer does not cause the influence of optical interference in the anti-glare layer because internal scattering of light occurs due to mat particles having a particle diameter of 1 to 10 μm dispersed in the high refractive index binder polymer. . In the high-refractive index antiglare layer having no matte particle of the above particle size, the amplitude of the reflectivity is large in the wavelength dependence of the reflectivity due to optical interference due to the difference in refractive index between the antiglare layer and the support. As a result, the antireflection effect deteriorates, and at the same time, color unevenness occurs.
[0024]
The binder polymer is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a polymer having a saturated hydrocarbon chain as a main chain.
The binder polymer preferably has a crosslinked structure.
As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable.
In order to obtain a high refractive index, the monomer structure preferably contains an aromatic ring or at least one atom selected from halogen atoms other than fluorine, sulfur atoms, phosphorus atoms, and nitrogen atoms.
[0025]
Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-dichlorohexane diacrylate, pentaerythritol tetra). (Meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, Pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and its derivatives ( 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinylsulfone (eg, divinylsulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide. It is done.
[0026]
Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, and the like.
[0027]
Polymerization of these monomers having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
Therefore, a coating liquid containing a monomer having an ethylenically unsaturated group, fine particles, and a photo radical initiator or a thermal radical initiator is prepared, and the coating liquid is applied onto a transparent support and then subjected to a polymerization reaction by ionizing radiation or heat. Can be cured to form an antiglare layer.
[0028]
The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Accordingly, a coating liquid containing a polyfunctional epoxy compound, fine particles, and a photoacid generator or a thermal acid generator is prepared, and the coating liquid is applied onto a transparent support and then cured by ionizing radiation or heat polymerization. An antiglare layer can be formed.
[0029]
Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, the crosslinkable functional group is not limited to the above functional group, and may be one that exhibits reactivity as a result of decomposition of the functional group. These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.
[0030]
The antiglare layer has an average particle size of 1 to 10 μm as a matte particle for the purpose of imparting antiglare properties and preventing reflectance deterioration due to interference of a hard coat layer provided under the antiglare layer, and preventing uneven color. Preferably, particles of 1.5 to 5 μm, for example, inorganic compound particles or resin particles are contained.
Specific examples of the particles include silica particles and TiO. ₂ Preferred examples include particles of inorganic compounds such as particles; resin particles such as crosslinked acrylic particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles. Among these, the above resin particles are preferable.
As the shape of the particle, either a true sphere or an indefinite shape can be used.
Two or more different kinds of particles may be used in combination.
Moreover, it is preferable that the mat | matte particle of a particle size smaller than the binder film thickness of an anti-glare layer is less than 50% of the whole mat | matte particle. The particle size distribution can be measured by the Coulter counter method, but the distribution is converted to a particle number distribution.
The amount of particles in the formed antiglare layer is preferably 10 to 1000 mg / m. ² , More preferably 30-100 mg / m ² It is contained in the antiglare layer so that.
[0031]
The antiglare layer is made of an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, in addition to the above mat particles, in order to increase the refractive index of the layer. Therefore, it is preferable to contain inorganic fine particles having a particle size of 100 nm or less, preferably 50 nm or less.
As a specific example of the inorganic fine particles, TiO ₂ , ZrO ₂ , Al ₂ O _Three , In ₂ O _Three ZnO, SnO ₂ , Sb ₂ O _Three And fine particles such as ITO.
The amount of these inorganic fine particles added is preferably 10 to 90%, more preferably 20 to 80% of the total mass of the antiglare layer.
Note that such fine particles have a particle size sufficiently smaller than the wavelength of light, and thus haze does not increase, and a dispersion in which the fine particles are dispersed in a binder polymer behaves as an optically uniform substance.
[0032]
As described above, the refractive index of the dispersion in which the components excluding the mat particles dispersed in the antiglare layer, that is, the binder polymer or the fine particle component of the metal oxide having a particle size of 100 nm or less is dispersed therein. It is preferably 1.57 to 2.00, more preferably 1.60 to 1.80. In order to make the refractive index within the above range, the type and amount ratio of the binder polymer and metal oxide fine particles may be appropriately selected. How to select can be easily known experimentally in advance.
[0033]
The film thickness of the antiglare layer is preferably from 0.5 to 10 μm, more preferably from 1 to 5 μm.
[0034]
In the antiglare antireflection film of the present invention, a smooth hard coat layer may be provided between the transparent support and the antiglare layer for the purpose of improving the film strength, if necessary.
The film thickness of the smooth hard coat layer is preferably 1 to 10 μm, more preferably 1.2 to 6 μm.
The components used for the smooth hard coat layer are the same as those mentioned for the antiglare layer except that no mat particles are used.
[0035]
As described above, the refractive index of the low refractive index layer of the antiglare antireflection film of the present invention is preferably in the range of 1.38 to 1.49. When the refractive index is in the above range, both sufficient antireflection properties and scratch resistance can be achieved, and preferable results can be obtained.
Furthermore, it is preferable in terms of antireflection properties that the (B) low refractive index layer satisfies the following formula (I).
[0036]
(Mλ / 4) × 0.7 <n ₁ d ₁ <(Mλ / 4) × 1.3 ...... Formula (I)
[0037]
Where m is a positive odd number and n ₁ Is the refractive index of the low refractive index layer and d ₁ Is the film thickness (nm) of the low refractive index layer. Also, λ is a wavelength and is a value in the range of 500 to 550 (nm).
In addition, satisfy | filling said numerical formula (I) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (I) exists in the said wavelength range.
[0038]
The low refractive index layer is preferably made of a cured product of a thermosetting or ionizing radiation curable fluorine-containing resin.
The cured product of the fluororesin preferably has a dynamic friction coefficient of 0.03 to 0.15 and a contact angle with water of 90 to 120 degrees.
Perfluoroalkyl group-containing silane compounds (eg, (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane), fluorine-containing vinyl monomers, and crosslinkable groups as the fluorine-containing resin before curing Preferable examples include fluorine-containing copolymers formed from monomers for imparting.
When the fluorine-containing copolymer has a thermally crosslinkable functional group, it is a thermosetting type, and when it has an ionizing radiation crosslinkable functional group, it is an ionizing radiation curable type.
[0039]
Specific examples of the fluorine-containing vinyl monomer include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3. -Dioxoles, etc.), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, etc. Can be mentioned.
As the monomer for imparting a crosslinkable group, in addition to a (meth) acrylate monomer having a crosslinkable functional group in the molecule in advance such as glycidyl methacrylate, a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, etc. (Meth) acrylate monomers (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, etc.). It is described in JP-A-10-25388 and JP-A-10-147739 that the latter can introduce a crosslinked structure after copolymerization.
[0040]
In addition to the above monomers, a fluorine-containing copolymer formed by using a monomer other than the fluorine-containing vinyl monomer and the monomer for imparting a crosslinkable group as a fluorine-containing resin before curing. It may be used.
Monomers that can be used in combination are not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid) 2-ethylhexyl), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers ( Methyl vinyl ether), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamides (N-tertbutylacrylamide, N-cyclohexylacrylamide, etc.), methacrylamides, acrylics Mention may be made of a nitrile derivatives, and the like.
[0041]
The proportion of each of the monomers used for forming the fluorinated copolymer before curing is preferably 20 to 80% by mass of the fluorinated vinyl monomer, and a monomer for imparting a crosslinkable group. Is preferably 1 to 30% by mass, and the other monomer used in combination is preferably 0 to 70% by mass.
[0042]
Inorganic fine particles can be added to the low refractive index layer of the antiglare antireflection film of the present invention. Thereby, volume shrinkage at the time of curing is reduced, adhesion is improved and scratch resistance is prevented from being lowered, and the hardness of the inorganic fine particles improves film strength and scratch resistance.
[0043]
As the inorganic fine particles used in the low refractive index layer, amorphous particles are preferably used, and preferably composed of metal oxides, nitrides, sulfides or halides, and metal oxides are particularly preferable.
As metal atoms, Na, K, Mg, Ca, Ba, Al, Zn, Fe, Cu, Ti, Sn, In, W, Y, Sb, Mn, Ga, V, Nb, Ta, Ag, Si, B Bi, Mo, Ce, Cd, Be, Pb and Ni are preferred, and Mg, Ca, B and Si are more preferred. Inorganic fine particles containing two or more metals may be used. Particularly preferred inorganic fine particles are silicon dioxide fine particles, that is, silica fine particles.
The average particle size of the inorganic fine particles is preferably 0.001 to 0.2 μm, and more preferably 0.005 to 0.05 μm. The particle diameter of the fine particles is preferably as uniform (monodispersed) as possible. If the particle size of the inorganic fine particles is too large, the film becomes opaque.
[0044]
The blending amount of the inorganic fine particles is preferably 3 to 90% by mass, more preferably 5 to 70% by mass, and particularly preferably 7 to 50% by mass with respect to the total mass of the low refractive index layer. If the amount of inorganic fine particles added is too large, a continuous layer of a fluorine-containing copolymer component as a binder cannot be formed and becomes brittle, and if too small, the effect of adding fine particles cannot be obtained.
[0045]
The inorganic fine particles are preferably used after being subjected to a surface treatment. The surface treatment method includes physical surface treatment such as plasma discharge treatment and corona discharge treatment and chemical surface treatment using a coupling agent, but the use of a coupling agent is preferred. As the coupling agent, an organoalkoxy metal compound (eg, titanium coupling agent, silane coupling agent, etc.) is preferably used. When the inorganic fine particles are silica, treatment with a silane coupling agent is particularly effective.
[0046]
Curing is performed by applying a coating liquid and drying, followed by heating or irradiation with ionizing radiation (ultraviolet rays, electron beams, etc.) to form a low refractive index layer.
[0047]
The film thickness of the low refractive index layer of the antiglare antireflection film is preferably 0.05 to 0.2 μm, more preferably 0.08 to 0.12 μm.
[0048]
Setting the refractive index of the low refractive index layer to the range specified above and further satisfying the above formula (I) is performed by adjusting the solid content concentration of the coating liquid and the wet coating amount.
[0049]
In the above, each layer which comprises the anti-glare antireflection film of this invention was demonstrated.
As already mentioned, the antiglare antireflection film of the present invention is
(A) The average value of the specular reflectance at 5 degrees incidence in the wavelength region from 450 nm to 650 nm is 1.2% or less,
(B) Preferably, the average value in the wavelength region from 450 nm to 650 nm of the integrated reflectance at 5 degrees incidence is 2.5% or less,
(C) Preferably, the color of the specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65 in the wavelength range of 380 nm to 780 nm is L *, a *, b * value of the CIE 1976 L * a * b * color space. When measured, the colors satisfy L * ≦ 10, 0 ≦ a * ≦ 2, −5 ≦ b * ≦ 2, and
(D) Preferably, the haze value is in the range of 5 to 15%.
[0050]
Each layer of the antiglare antireflection film of the present invention comprises a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method and an extrusion coating method (US Pat. No. 2,681,294). ), A coating liquid for forming each layer can be applied, and if necessary, it can be formed by irradiation or heating. Two or more layers may be applied simultaneously. The methods for simultaneous application are described in US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, and 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, Asakura Shoten (1973).
[0051]
The antiglare antireflection film of the present invention can be applied to an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), or a cathode ray tube display device (CRT). it can. The antiglare antireflection film of the present invention is applied by bonding the transparent support side to the image display surface of the image display device, but when applied to the surface or the inner surface of the LCD, the polarizing layer of the polarizing plate is protected. It is more preferable to use it as it is as a film on one side of the two protective films.
[0052]
【Example】
In order to describe the present invention specifically, the following examples are given to illustrate the present invention, but the present invention is not limited to these examples.
[0053]
(Preparation of coating solution A for antiglare layer)
439 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) 125 g, bis (4-methacryloylthiophenyl) sulfide (MPSMA, Sumitomo Seika Co., Ltd.) 125 g In a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50% by mass. In the obtained solution, a solution obtained by dissolving 5.0 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and 3.0 g of a photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) in 49 g of methyl ethyl ketone. added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.60.
Furthermore, 10 g of crosslinked polystyrene particles having an average particle diameter of 2 μm (trade name: SX-200H, manufactured by Soken Chemical Co., Ltd.) was added to this solution, and the mixture was stirred and dispersed at 5000 rpm for 1 hour with a high-speed dispaper. A coating solution for the antiglare layer was prepared by filtration through a polypropylene filter.
[0054]
(Preparation of coating solution B for antiglare layer)
To a mixed solvent of 104.1 g of cyclohexanone and 61.3 g of methyl ethyl ketone, 217.0 g of a hard coat coating solution containing zirconium oxide dispersion (Desolite KZ-7886A, manufactured by JSR Corporation) was added while stirring with an air disperser. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.61.
Further, 5 g of a crosslinked polystyrene particle having an average particle diameter of 2 μm (trade name: SX-200H, manufactured by Soken Chemical Co., Ltd.) was added to this solution, and the mixture was stirred and dispersed at 5000 rpm for 1 hour with a high-speed dispaper. An antiglare layer coating solution was prepared by filtration through a polypropylene filter.
[0055]
(Preparation of coating solution C for antiglare layer)
91 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.), zirconium oxide dispersion-containing hard coat coating solution (Desolite KZ-7115, manufactured by JSR Co., Ltd.) 199 g, and 19 g of a zirconium oxide dispersion-containing hard coat coating solution (Desolite KZ-7161, manufactured by JSR Corporation) was dissolved in a mixed solvent of 52 g of methyl ethyl ketone / cyclohexanone = 54/46% by mass. 10 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) was added to the resulting solution. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.61.
Furthermore, 20 g of crosslinked polystyrene particles having an average particle diameter of 2 μm (trade name: SX-200H, manufactured by Soken Chemical Co., Ltd.) was added to this solution in a mixed solvent of 80 g of methyl ethyl ketone / cyclohexanone = 54/46 mass% at a high speed disperser at 5000 rpm. After adding and stirring 29 g of the dispersion that was stirred and dispersed for 1 hour, the mixture was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution for the antiglare layer.
[0056]
(Preparation of coating liquid D for hard coat layer)
A solution prepared by dissolving 250 g of an ultraviolet curable hard coat composition (Desolite KZ-7689, 72% by mass, manufactured by JSR Corporation) in 62 g of methyl ethyl ketone and 88 g of cyclohexanone was added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.53.
Further, this solution was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a coating solution for a hard coat layer.
[0057]
(Preparation of coating solution for low refractive index layer)
MEK-ST (MEK dispersion of SiO2 sol having an average particle size of 10 to 20 nm and a solid content concentration of 30% by mass) is added to 93 g of a heat-crosslinkable fluorine-containing polymer (TN-049, manufactured by JSR Corporation) having a refractive index of 1.42. 8 g of Nissan Chemical Co., Ltd.) and 100 g of methyl ethyl ketone were added. After stirring, the mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a low refractive index layer.
[0058]
[Example 1]
The above-mentioned coating liquid D for hard coat layer was applied to a triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm using a bar coater, and after drying at 120 ° C., 160 W Illuminance of 400 mW / cm using an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) ² , Irradiation amount 300mJ / cm ² The ultraviolet ray was irradiated to cure the coating layer, and a hard coat layer having a thickness of 2.5 μm was formed.
On top of that, the antiglare layer coating solution A was applied using a bar coater, dried and UV cured under the same conditions as the hard coat layer to form an antiglare layer having a thickness of about 1.5 μm. .
On top of that, the above coating solution for the low refractive index layer is applied using a bar coater, dried at 80 ° C., and then thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. did.
[0059]
[Example 2]
A hard coat layer was formed in the same manner as in Example 1 on a triacetylcellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm. On top of that, the antiglare layer coating solution B was applied using a bar coater, dried and UV cured under the same conditions as the hard coat layer to form an antiglare layer having a thickness of about 1.5 μm. .
On top of that, the above coating solution for the low refractive index layer is applied using a bar coater, dried at 80 ° C., and then thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. did.
[0060]
[Example 3]
A hard coat layer was formed in the same manner as in Example 1 on a triacetylcellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm. On top of that, the antiglare layer coating solution C was applied using a bar coater, dried and UV cured under the same conditions as the hard coat layer to form an antiglare layer having a thickness of about 1.5 μm. .
On top of that, the above coating solution for the low refractive index layer is applied using a bar coater, dried at 80 ° C., and then thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. did.
[0061]
[Comparative Example 1]
The above-mentioned coating liquid D for hard coat layer was applied to a triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm using a bar coater, and after drying at 120 ° C., 160 W Illuminance of 400 mW / cm using an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) ² , Irradiation amount 300mJ / cm ² The coating layer was cured by irradiating the ultraviolet rays, and a hard coat layer having a thickness of 4 μm was formed.
On top of that, except that MPSMA was entirely replaced with DPHA, an antiglare layer coating solution similar to the above antiglare layer coating solution A was applied using a bar coater, and dried under the same conditions as the hard coat layer. UV-cured to form an antiglare layer having a thickness of about 1.5 μm and a refractive index of 1.51.
On top of that, the above coating solution for the low refractive index layer is applied using a bar coater, dried at 80 ° C., and then thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. did.
[0062]
(Evaluation of antireflection film)
About the obtained film, the following items were evaluated.
(1) Specular reflectance and color
A spectrophotometer V-550 (manufactured by JASCO Corporation) is equipped with an adapter ARV-474, and in the wavelength region of 380 to 780 nm, the specular reflectance at an incident angle of 5 ° at an incident angle of 5 ° is measured. An average reflectance of 450 to 650 nm was calculated, and antireflection properties were evaluated.
Further, CIE 1976 L * a * b * color space L * value, a * value, and b * value representing the color of the specularly reflected light with respect to the 5 degree incident light of the CIE standard light source D65 are calculated from the measured reflection spectrum. The color of reflected light was evaluated.
(2) Integral reflectance
An adapter ILV-471 is attached to a spectrophotometer V-550 (manufactured by JASCO Corporation), and an integrated reflectance at an incident angle of 5 ° is measured in a wavelength region of 380 to 780 nm, and an average reflection of 450 to 650 nm. The rate was calculated.
(3) Haze
The haze of the obtained film was measured using a haze meter MODEL 1001DP (manufactured by Nippon Denshoku Industries Co., Ltd.).
(4) Pencil hardness evaluation
The pencil hardness evaluation described in JIS K 5400 was performed as an index of scratch resistance. After conditioning the antireflection film at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, using a 3H test pencil specified in JIS S 6006, with a load of 1 kg
No scratch is observed in the evaluation of n = 5: ○
In evaluation of n = 5, 1 or 2 scratches:
In evaluation of n = 5, 3 or more scratches: ×
(5) Contact angle measurement
As an index of surface contamination resistance (fingerprint adhesion), the optical material was conditioned at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, and then the contact angle with water was measured.
[0063]
(6) Dynamic friction coefficient measurement
The dynamic friction coefficient was evaluated as an index of surface slipperiness. As the dynamic friction coefficient, a sample was conditioned at 25 ° C. and a relative humidity of 60% for 2 hours, and then a value measured with a HEIDON-14 dynamic friction measuring machine at a 5 mmφ stainless steel ball, a load of 100 g, and a speed of 60 cm / min was used.
(7) Anti-glare evaluation
Bare fluorescent light (8000 cd / m) without louver on the anti-glare film ² ) And the degree of blur of the reflected image was evaluated according to the following criteria.
I do not know the outline of the fluorescent lamp at all: ◎
Slightly understand the outline of the fluorescent lamp: ○
The fluorescent lamp is blurred, but the outline can be identified: △
Fluorescent lamp is hardly blurred: ×
[0064]
Table 1 shows the results of Examples and Comparative Examples.
From the results shown in Table 1, the following is clear.
Any of the antiglare and antireflection films of Examples 1, 2, and 3 is excellent in antiglare and antireflection properties, has a weak color, and reflects film properties such as pencil hardness, fingerprint adhesion, and dynamic friction coefficient. The evaluation results were also good.
On the other hand, in Comparative Example 1, since the refractive index of the antiglare layer was low, sufficient antireflection properties could not be obtained.
[0065]
[Table 1]

[0066]
Next, an antiglare antireflection polarizing plate was prepared using the film of Example 3. Using this polarizing plate, a liquid crystal display device having an antireflection layer arranged on the outermost layer was created. As a result, there was no reflection of external light, and an excellent contrast was obtained. Visibility was good and fingerprinting was good.
[0067]
(Preparation of triacetyl cellulose dope A)
A raw material composed of 17.4 parts by mass of triacetyl cellulose, 2.6 parts by mass of triphenyl phosphate, 66 parts by mass of dichloromethane, 5.8 parts by mass of methanol, and 8.2 parts by mass of normal butanol was mixed and dissolved while stirring. A triacetylcellulose dope A was prepared.
[0068]
(Preparation of triacetylcellulose dope B)
A raw material consisting of 24 parts by mass of triacetyl cellulose, 4 parts by mass of triphenyl phosphate, 66 parts by mass of dichloromethane, and 6 parts by mass of methanol was mixed and dissolved while stirring to prepare triacetyl cellulose dope B.
[0069]
(Preparation of triacetyl cellulose dope C)
20 parts by mass of triacetyl cellulose, 48 parts by mass of methyl acetate, 20 parts by mass of cyclohexanone, 5 parts by mass of methanol, 5 parts by mass of ethanol, 2 parts by mass of triphenyl phosphate / biphenyl diphenyl phosphate (1/2), silica (particle size 20 nm) 0.1 parts by mass, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine 0.2 parts by mass Was added, and the heterogeneous gel-like solution obtained by stirring was cooled at −70 ° C. for 6 hours, and then heated to 50 ° C. and stirred to prepare Dope C.
[0070]
(Preparation of triacetyl cellulose dope D)
The heterogeneous gel-like solution obtained in the same manner as in the above triacetylcellulose dope C was heated in a stainless steel sealed container at 1 MPa and 180 ° C. for 5 minutes, and then poured into a 50 ° C. water bath and cooled. Triacetylcellulose dope D was prepared.
[0071]
(Preparation of coating solution A ′ for antiglare layer)
A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) 91 g, zirconium oxide dispersion-containing hard coat coating solution (Desolite Z-7401, JSR Co., Ltd.) 218 g, 52 g of methyl ethyl ketone / cyclohexanone was dissolved in a mixed solvent of 54/46% by mass. 10 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) was added to the resulting solution. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.61.
Further, 20 g of crosslinked polystyrene particles having an average particle diameter of 2 μm (trade name: SX-200H, manufactured by Soken Chemical Co., Ltd.) was added to this solution in a mixed solvent of 80 g of methyl ethyl ketone / cyclohexanone = 54/46 mass% at a high speed disperser at 5000 rpm. After adding and stirring 29 g of the dispersion obtained by stirring and dispersing for 1 hour, the mixture was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution A for an antiglare layer.
[0072]
(Preparation of coating solution B ′ for antiglare layer)
250 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was dissolved in 439 g of a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50 mass%. In the obtained solution, a solution prepared by dissolving 5.0 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and 3.0 g of a photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) in 49 g of methyl ethyl ketone. added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.51.
Furthermore, 10 g of crosslinked polystyrene particles having an average particle diameter of 2 μm (trade name: SX-200H, manufactured by Soken Chemical Co., Ltd.) were added to this solution, and the mixture was stirred and dispersed at 5000 rpm for 1 hour with a high-speed dispaper. A coating solution B ′ for an antiglare layer was prepared by filtration through a polypropylene filter.
[0073]
(Preparation of coating liquid C ′ for hard coat layer)
A solution prepared by dissolving 250 g of an ultraviolet curable hard coat composition (Desolite Z-7526, 72 mass%, manufactured by JSR Corporation) in 62 g of methyl ethyl ketone and 88 g of cyclohexanone was added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.53.
Further, this solution was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a hard coat layer coating solution C ′.
[0074]
(Preparation of coating solution D ′ for low refractive index layer)
It has a refractive index of 1.42, MEK-ST (average particle size 10 to 20 nm, solid content concentration 30 mass) to 93 g of a 6 mass% methyl ethyl ketone solution (JN-7228, manufactured by JSR Corporation) of a heat-crosslinkable fluoropolymer. % SiO ₂ Add sol methyl ethyl ketone dispersion (manufactured by Nissan Chemical Co., Ltd.) 8g, methyl ethyl ketone 94g, and cyclohexanone 6g, and after stirring, filter through a polypropylene filter (PPE-01) with a pore size of 1 μm to apply a low refractive index layer. Liquid D ′ was prepared.
[0075]
[Example 4]
According to Japanese Patent Laid-Open No. 11-254594, etc., a three-layer co-casting die is used so that the dope A is co-cast on both sides of the dope B. The membrane was peeled off from the drum and dried to produce a 10-μm, 60-μm, 10-μm three-layer co-cast triacetylcellulose film from both sides of the drum. In this film, no clear interface was formed between the respective layers.
The above-mentioned triacetyl cellulose film was coated with the above-mentioned coating solution C ′ for hard coat layer using a bar coater, dried at 120 ° C. for 5 minutes, and then an air-cooled metal halide lamp (I Graphics Co., Ltd.) of 160 W / cm. Illuminance 400 mW / cm ² , Irradiation amount 300mJ / cm ² The ultraviolet ray was irradiated to cure the coating layer, and a hard coat layer having a thickness of 2.5 μm was formed.
On top of this, the coating solution A ′ for the antiglare layer was applied using a bar coater, dried and UV cured under the same conditions as the hard coat layer except that the oxygen concentration in the atmosphere was changed to 6% by nitrogen purge. Thus, an antiglare layer having a thickness of about 1.5 μm was formed.
On top of this, the low refractive index coating solution D ′ is applied using a bar coater, dried at 80 ° C., and further thermally crosslinked at 120 ° C. for 8 minutes to form a low refractive index layer having a thickness of 0.096 μm. Formed.
[0076]
[Example 5]
According to Japanese Patent Laid-Open No. 7-11055, the triacetyl cellulose dope C is cast as a single layer drum to prepare a triacetyl cellulose film having a thickness of 80 μm, and a hard coat layer and an antiglare layer are formed thereon in the same manner as in Example 4. , And a low refractive index layer.
[0077]
[Example 6]
According to Japanese Patent Laid-Open No. 7-11055, the triacetyl cellulose dope D is cast as a single layer drum to prepare a triacetyl cellulose film having a thickness of 80 μm, and a hard coat layer and an antiglare layer are formed thereon as in Example 4. , And a low refractive index layer.
[0078]
[Comparative Example 2]
The above-mentioned hard coat layer coating solution D ′ was applied to an 80 μm-thick triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) using a bar coater, and after drying at 120 ° C., Illuminance of 400 mW / cm using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) ² , Irradiation amount 300mJ / cm ² The coating layer was cured by irradiating the ultraviolet rays, and a hard coat layer having a thickness of 4 μm was formed.
On top of that, coating solution B ′ for antiglare layer was applied using a bar coater, dried under the same conditions as the hard coat layer, and then UV-cured to have a thickness of about 1.5 μm and a refractive index of 1.51. An antiglare layer was formed.
On top of this, the low refractive index layer coating solution D ′ is applied using a bar coater, dried at 80 ° C., and further thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. Formed.
[0079]
Table 2 shows the results of Examples 4 to 6 and Comparative Example 2. The evaluation method is as described above.
From the results shown in Table 2, the following is clear.
Any of the antiglare and antireflection films of Examples 4, 5, and 6 is excellent in antiglare and antireflection properties, has a weak color, and reflects film properties such as pencil hardness, fingerprint adhesion, and dynamic friction coefficient. The evaluation results were also good.
On the other hand, in Comparative Example 2, since the refractive index of the antiglare layer was low, sufficient antireflection properties could not be obtained.
[0080]
[Table 2]

[0081]
Next, an antiglare antireflection polarizing plate was prepared using the film of Example 6. Using this polarizing plate, a liquid crystal display device in which an antireflection layer was disposed on the outermost layer was created. As a result, there was no reflection of external light, and excellent contrast was obtained. Visibility was good and fingerprints were good.
[0082]
【The invention's effect】
The antiglare antireflection film of the present invention is produced simply and inexpensively by simply forming an antiglare layer and a low refractive index layer on a support, and also has sufficient antireflection performance and scratch resistance, as well as anti-glare properties. It has dirtiness and has little color and uneven color.
Furthermore, the polarizing plate and the liquid crystal display device of the present invention are excellent in antifouling property and scratch resistance because the reflection of external light is sufficiently prevented and excellent contrast is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing the layer structure of an antiglare antireflection film.
[Explanation of symbols]
1 Anti-glare anti-reflection film
2 Transparent support made of triacetylcellulose
3 Hard coat layer
4 Anti-glare layer
5 Low refractive index layer
6 Resin matte particles

Claims (10)

On the transparent support, an antiglare layer and at least one low refractive index layer are provided in this order, and the antiglare layer is composed of mat particles having a particle diameter of 1 to 10 μm and metal oxide having a particle diameter of 100 nm or less. It has fine particles, the addition amount of the metal oxide fine particles is 10 to 90% of the total mass of the antiglare layer, and the average value in the wavelength region from 450 nm to 650 nm of the specular reflectance at 5 degrees incidence is 1 An antiglare antireflection film, wherein the average value in the wavelength region from 450 nm to 650 nm of the integrated reflectance at 5 ° incidence is 2.5% or less.   The antiglare antireflection film according to claim 1, further comprising a smooth hard coat layer between the transparent support and the antiglare layer.   Triacetyl produced by casting a triacetyl cellulose dope prepared by dissolving a triacetyl cellulose in a solvent in a single-layer casting or multi-layer co-casting. The antiglare antireflection film according to claim 1, wherein the antiglare antireflection film is a cellulose film.   The triacetyl cellulose dope is a triacetyl cellulose dope prepared by dissolving triacetyl cellulose in a solvent substantially free of dichloromethane by a low temperature dissolution method or a high temperature dissolution method. The antiglare antireflection film as described.   CIE standard light source D65 in the wavelength range of 380 nm to 780 nm has a color of specularly reflected light with respect to 5 ° incident light, and L *, a *, and b * values of CIE 1976 L * a * b * color space are L * ≦ 10, The antiglare antireflection film according to claim 1, wherein the antiglare antireflection film has a color that satisfies 0 ≦ a * ≦ 2 and −5 ≦ b * ≦ 2.   The antiglare antireflection film according to any one of claims 1 to 5, wherein the haze value is in the range of 5 to 15%.   The anti-glare antireflection film according to any one of claims 1 to 6, wherein the low refractive index layer is made of a cured product of a thermosetting or ionizing radiation curable fluorine-containing resin.   The dynamic friction coefficient of the low refractive index layer made of a cured product of the fluororesin is in the range of 0.03 to 0.15, and the contact angle with water is in the range of 90 to 120 degrees. 8. An antiglare antireflection film according to 7.   A polarizing plate, wherein the antiglare antireflection film according to claim 1 is used for at least one of two protective films of a polarizing layer in a polarizing plate.   A liquid crystal comprising the antiglare antireflection film according to any one of claims 1 to 8 or the antireflection layer of the antiglare antireflection polarizing plate according to claim 9 as an outermost layer of a display. Display device.

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