JP2000329939A - Production of phase difference film, optical member and liquid crystal display device - Google Patents
Production of phase difference film, optical member and liquid crystal display deviceInfo
- Publication number
- JP2000329939A JP2000329939A JP11143492A JP14349299A JP2000329939A JP 2000329939 A JP2000329939 A JP 2000329939A JP 11143492 A JP11143492 A JP 11143492A JP 14349299 A JP14349299 A JP 14349299A JP 2000329939 A JP2000329939 A JP 2000329939A
- Authority
- JP
- Japan
- Prior art keywords
- film
- heat
- shrinkable
- phase difference
- liquid crystal
- 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
【０００１】[0001]
【発明の技術分野】本発明は、液晶表示装置の視野角や
コントラストの改善に好適な位相差フィルムを歩留まり
よく製造できる方法、及びその位相差フィルムを用いた
光学部材に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a retardation film suitable for improving a viewing angle and a contrast of a liquid crystal display device with a high yield, and an optical member using the retardation film.
【０００２】[0002]
【従来の技術】従来、液晶セルの複屈折による位相差を
補償して液晶表示装置の視野角の拡大やコントラストの
向上を達成しうる位相差フィルムの製造方法として、透
光性フィルムに熱収縮性フィルムを接着して加熱による
その収縮力の作用下に延伸処理する方法が知られていた
（特開平５−１５７９１１号公報）。かかる延伸処理後
の熱収縮性フィルムは得られた位相差フィルムより剥離
される。2. Description of the Related Art Conventionally, as a method of manufacturing a retardation film capable of compensating for a phase difference due to birefringence of a liquid crystal cell and achieving an increase in a viewing angle and an improvement in contrast of a liquid crystal display device, a heat-shrinkable light-transmitting film is used. A method has been known in which a stretchable film is adhered and stretched under the action of its shrinkage by heating (Japanese Patent Application Laid-Open No. 5-157911). The heat-shrinkable film after the stretching treatment is peeled off from the obtained retardation film.
【０００３】しかしながら、熱収縮性フィルムの収縮処
理時に接着層間に発泡が生じて得られた位相差フィルム
に発泡痕が残存したり、収縮処理後の熱収縮性フィルム
が加熱処理等による接着力の増大で得られた位相差フィ
ルムと強力に接着して剥離できなかったり、剥離の際に
位相差フィルムが破断したり、外観を毀損したり、剥離
後に位相差フィルムに接着剤が糊残りしたりして得られ
る位相差フィルムの歩留まりに乏しい問題点があった。However, foaming occurs between the adhesive layers during shrinking of the heat-shrinkable film, leaving foaming marks on the obtained retardation film, or the heat-shrinkable film after the shrinkage treatment has an adhesive strength due to heat treatment or the like. Strongly adhered to the retardation film obtained by the increase and could not be peeled, the retardation film was broken at the time of peeling, the appearance was damaged, and the adhesive remained on the retardation film after peeling. There is a problem that the yield of the obtained retardation film is poor.
【０００４】[0004]
【発明の技術的課題】本発明は、収縮処理時の発泡を防
止できると共に、得られた位相差フィルムより収縮処理
後の熱収縮性フィルムを容易に剥離分離できて剥離の際
の位相差フィルムの破断や外観毀損、剥離後の糊残りを
抑制できて品質の良好な位相差フィルムを歩留まりよく
得ることができる製造方法の開発を課題とする。SUMMARY OF THE INVENTION The present invention can prevent foaming during shrinkage treatment, and can easily peel off and separate a heat-shrinkable film after shrinkage treatment from the obtained retardation film, so that a retardation film upon peeling can be obtained. It is an object of the present invention to develop a manufacturing method capable of suppressing breakage, appearance damage, and adhesive residue after peeling, and obtaining a good quality retardation film with good yield.
【０００５】[0005]
【課題の解決手段】本発明は、透光性フィルムの片面又
は両面に熱収縮性フィルムを接着して、加熱によるその
熱収縮性フィルムの収縮力の作用下に透光性フィルムを
少なくとも縦横の一方向に延伸又は収縮させたのち当該
熱収縮性フィルムを剥離して位相差フィルムを得るにあ
たり、前記の熱収縮性フィルムとしてその加熱収縮前に
おける当該透光性フィルムとの接着力が３５〜８０ｇ／
20mmのものを用いることを特徴とする位相差フィルムの
製造方法を提供するものである。According to the present invention, a heat-shrinkable film is adhered to one or both surfaces of a light-transmissive film, and the heat-shrinkable film is stretched at least vertically and horizontally under the action of the heat-shrinkable film. Upon peeling or shrinking the heat-shrinkable film after stretching or shrinking in one direction to obtain a retardation film, the heat-shrinkable film has an adhesive force with the translucent film before heat shrinkage of 35 to 80 g. /
An object of the present invention is to provide a method for manufacturing a retardation film, characterized in that a film having a thickness of 20 mm is used.
【０００６】また本発明は、前記製造方法による位相差
フィルムを粘着層を介して偏光板と接着したことを特徴
とする光学部材、並びに前記製造方法による位相差フィ
ルム又は前記光学部材を液晶セルの少なくとも片側に有
することを特徴とする液晶表示装置を提供するものであ
る。Further, the present invention provides an optical member characterized in that the retardation film produced by the above-mentioned production method is adhered to a polarizing plate via an adhesive layer, and the retardation film produced by the above-mentioned production method or the above-mentioned optical member is formed of a liquid crystal cell. A liquid crystal display device provided at least on one side is provided.
【０００７】[0007]
【発明の効果】本発明によれば、熱収縮性フィルムを収
縮処理する際に透光性フィルムとの接着界面に発泡の生
じることを抑制できて発泡痕のない位相差フィルムを得
ることができると共に、収縮処理後の熱収縮性フィルム
を容易に剥離して分離でき、それを剥離する際に位相差
フィルムに破断や外観毀損の生じることを抑制でき、ま
た剥離後の位相差フィルムにおける糊残りも抑制できて
品質の良好な位相差フィルムを歩留まりよく得ることが
できる。その結果、熱収縮性フィルムの収縮力の作用下
に位相差を高度に制御した位相差フィルムを効率よく得
て、それを用いて液晶セルの複屈折による位相差を高度
に補償して視野角やコントラストに優れる液晶表示装置
を得ることができる。According to the present invention, when a heat-shrinkable film is subjected to a shrinkage treatment, the occurrence of foaming at the bonding interface with the light-transmitting film can be suppressed, and a phase difference film without foaming marks can be obtained. At the same time, the heat-shrinkable film after the shrinkage treatment can be easily peeled and separated, and when the film is peeled, breakage and appearance damage of the retardation film can be suppressed, and adhesive residue on the retardation film after peeling can be suppressed. And a retardation film having good quality can be obtained with high yield. As a result, a retardation film with a highly controlled retardation under the action of the contraction force of the heat-shrinkable film can be efficiently obtained, and the retardation film due to the birefringence of the liquid crystal cell is highly compensated for using the retardation film. And a liquid crystal display device excellent in contrast can be obtained.
【０００８】[0008]
【発明の実施形態】本発明による製造方法は、透光性フ
ィルムの片面又は両面に熱収縮性フィルムを接着して、
加熱によるその熱収縮性フィルムの収縮力の作用下に透
光性フィルムを少なくとも縦横の一方向に延伸又は収縮
させたのち当該熱収縮性フィルムを剥離して位相差フィ
ルムを得るにあたり、前記の熱収縮性フィルムとしてそ
の加熱収縮前における当該透光性フィルムとの接着力が
３５〜８０ｇ／20mmのものを用いるものである。DESCRIPTION OF THE PREFERRED EMBODIMENTS The production method according to the present invention comprises the steps of: adhering a heat-shrinkable film to one or both surfaces of a light-transmitting film;
The heat-shrinkable film is stretched or shrunk in at least one direction vertically and horizontally under the action of the shrinkage force of the heat-shrinkable film by heating, and then the heat-shrinkable film is peeled off to obtain a retardation film. As the shrinkable film, one having an adhesive force with the light-transmitting film before heat shrinkage of 35 to 80 g / 20 mm is used.
【０００９】透光性フィルムとしては、特に限定はな
く、光透過性の適宜な熱可塑性樹脂からなるフィルムを
用いうる。就中、光透過率が７５％以上、特に８５％以
上の透光性に優れるフィルムが好ましい。また耐熱性に
優れる位相差フィルムを得る点よりは、延伸方向の屈折
率が高くなる正の複屈折特性を示すポリマーからなるも
のが好ましく用いられる。The light-transmitting film is not particularly limited, and a film made of an appropriate light-transmitting thermoplastic resin can be used. Above all, a film having a light transmittance of 75% or more, particularly 85% or more, which is excellent in light transmittance, is preferable. From the viewpoint of obtaining a retardation film having excellent heat resistance, a polymer made of a polymer exhibiting a positive birefringence property and having a high refractive index in the stretching direction is preferably used.
【００１０】ちなみに前記した正の複屈折特性を示すポ
リマーの例としてはポリカーボネート、ポリビニルアル
コール、セルロース系樹脂、ポリエチレンテレフタレー
トやポリエチレンナフタレートの如きポリエステル、ポ
リアリレート、ポリイミド、ノルボルネン系樹脂、ポリ
スルホン、ポリエーテルスルホン、ポリプロピレンの如
きポリオレフィンなどがあげられる。Incidentally, examples of the polymer having a positive birefringence characteristic include polycarbonate, polyvinyl alcohol, cellulose resin, polyester such as polyethylene terephthalate and polyethylene naphthalate, polyarylate, polyimide, norbornene resin, polysulfone, and polyether. And polyolefins such as sulfone and polypropylene.
【００１１】透光性フィルムは、例えば流延法等のキャ
スティング法や、押出法などの適宜な方式で形成したも
のであってよい。キャスティング法等の溶液製膜法が厚
さムラや配向歪ムラ等の少ないフィルムを得る点などよ
り好ましい。透光性フィルムは、バッチ処理用の規定サ
イズにて用いることもできるし、連続製造を目的に長尺
フィルムとして用いることもできる。The light-transmitting film may be formed by an appropriate method such as a casting method such as a casting method or an extrusion method. A solution casting method such as a casting method is more preferable in that a film having less unevenness in thickness and uneven orientation is obtained. The translucent film can be used in a prescribed size for batch processing, or can be used as a long film for continuous production.
【００１２】透光性フィルムの厚さは、目的とする位相
差フィルムの位相差特性などにより適宜に決定すること
ができる。一般には５〜５００μm、就中１０〜４００
μm、特に２０〜３００μmの厚さとされる。位相差は、
屈折率差（△ｎ）と光路長（Ｌ）の積（△ｎ×Ｌ）とし
て求めることができる。なお本発明にて処理対象とする
透光性フィルムは、無配向のものであってもよいし、予
め一軸延伸等の適宜な配向処理を施した配向フィルムで
あってもよい。The thickness of the translucent film can be appropriately determined according to the intended retardation characteristics of the retardation film. Generally 5 to 500 μm, especially 10 to 400
μm, especially 20 to 300 μm. The phase difference is
It can be obtained as the product (Δn × L) of the refractive index difference (Δn) and the optical path length (L). The translucent film to be treated in the present invention may be non-oriented, or may be an oriented film that has been subjected to an appropriate orientation treatment such as uniaxial stretching in advance.
【００１３】透光性フィルムの片面又は両面に接着する
熱収縮性フィルムは、その加熱による収縮力を透光性フ
ィルムに伝達してその収縮力の作用下に透光性フィルム
を縦又は横の一方向又は両方向に延伸又は収縮させてそ
の位相差特性、特に厚さ方向の屈折率を制御することな
どを目的とする。A heat-shrinkable film adhered to one or both sides of a light-transmitting film transmits a shrinkage force due to the heating to the light-transmitting film, and causes the light-shrinkable film to move vertically or horizontally under the action of the shrinkage force. An object is to control the retardation characteristics, particularly the refractive index in the thickness direction, by stretching or shrinking in one or both directions.
【００１４】従って熱収縮性フィルムとしては、加熱処
理にて収縮性を示す適宜なものを用いることができ、特
に限定はない。一般には熱可塑性樹脂からなるフィルム
の一軸や二軸等による延伸フィルムなどが用いられ、そ
の場合、熱可塑性樹脂の種類や延伸倍率等の延伸条件な
どを変えることにより熱収縮力に相違をもたせることが
できる。Accordingly, as the heat-shrinkable film, an appropriate film exhibiting shrinkage by heat treatment can be used, and there is no particular limitation. In general, a stretched film such as a uniaxial or biaxial film made of a thermoplastic resin is used, and in this case, a difference in heat shrinkage force is obtained by changing a stretching condition such as a type of the thermoplastic resin or a stretching ratio. Can be.
【００１５】前記において熱収縮力の付与性の点より
は、透光性フィルムのガラス転移温度付近にて熱収縮性
を示すものが好ましく用いられる。また透光性フィルム
に均一な配向を付与する点よりは、熱収縮力がフィルム
全面で可及的に均一で表面平滑性に優れる熱収縮性フィ
ルムが好ましく用いられる。In the above, from the viewpoint of imparting a heat shrinking force, a film showing heat shrinkage near the glass transition temperature of the light-transmitting film is preferably used. In addition, a heat-shrinkable film having a heat-shrinking force as uniform as possible over the entire surface and having excellent surface smoothness is preferably used, rather than imparting a uniform orientation to the translucent film.
【００１６】本発明による製造方法は、前記した熱収縮
性フィルムを３５〜８０ｇ／20mmの接着力で透光性フィ
ルムと接着してそれを加熱による熱収縮性フィルムの収
縮処理に供するようにしたものである。その収縮処理の
際における発泡の発生防止性、処理後の剥離の際におけ
る位相差フィルムの破断や外観毀損の防止性、剥離後の
位相差フィルムにおける糊残りの防止性などの点より好
ましい収縮処理前の熱収縮性フィルムと透光性フィルム
との接着力は、７５ｇ／20mm以下、就中４０〜７０ｇ／
20mmである。In the manufacturing method according to the present invention, the above-mentioned heat-shrinkable film is bonded to a light-transmitting film with an adhesive force of 35 to 80 g / 20 mm and subjected to a heat-shrinkable film shrinkage treatment by heating. Things. A preferable shrinkage treatment from the viewpoints of preventing foaming during the shrinkage treatment, preventing the retardation film from breaking or deteriorating its appearance at the time of peeling after the treatment, and preventing the adhesive from remaining on the retardation film after the peeling. The adhesive strength between the heat-shrinkable film and the translucent film before is 75 g / 20 mm or less, especially 40 to 70 g /
20mm.
【００１７】前記の点より熱収縮性フィルムと透光性フ
ィルムの接着には良密着による熱収縮力の伝播性なども
考慮して接着剤を用いることが好ましい。その接着剤と
しては前記の接着力を満足して、熱収縮性フィルムの熱
収縮処理時にはその収縮力を透光性フィルムに良好に伝
達し、処理後には透光性フィルムの処理物、すなわち得
られた位相差フィルムよりその光学特性を可及的に変質
させないで処理後の熱収縮性フィルムを分離できるもの
が好ましく用いられる。From the above point, it is preferable to use an adhesive in bonding the heat-shrinkable film and the light-transmitting film in consideration of the propagation of the heat-shrinkage force due to good adhesion. The adhesive satisfies the above-mentioned adhesive strength, and transmits the shrinkage force to the light-transmitting film during the heat-shrinking treatment of the heat-shrinkable film. A film capable of separating a heat-shrinkable film after treatment without changing the optical properties of the retardation film as much as possible is preferably used.
【００１８】前記の点よりは粘着層などが好ましく用い
られる。その粘着層としては、例えばアクリル系やシリ
コーン系、ポリエステル系やポリウレタン系、ポリエー
テル系やゴム系等の適宜なものを用いることができ、特
に限定はない。熱収縮性フィルムの加熱収縮処理で接着
力が上昇しにくい粘着層が好ましく用いられる。From the above-mentioned point, an adhesive layer or the like is preferably used. As the adhesive layer, for example, an appropriate material such as acrylic, silicone, polyester, polyurethane, polyether, or rubber can be used, and there is no particular limitation. An adhesive layer whose adhesive strength is unlikely to increase by heat shrinkage treatment of the heat shrinkable film is preferably used.
【００１９】上記の粘着層は、透光性フィルムと熱収縮
性フィルムの接着時にその一方又は両方の接着面に付設
することもできるが、形成された位相差フィルムと熱収
縮性フィルムの分離時にその熱収縮性フィルムに粘着層
が随伴した状態で分離できることが製造効率等の点より
好ましいことから、予め熱収縮性フィルムに粘着層を付
設したものとして用いることが好ましい。The above-mentioned pressure-sensitive adhesive layer can be provided on one or both of the bonding surfaces when the light-transmitting film and the heat-shrinkable film are bonded, but when the formed retardation film and the heat-shrinkable film are separated from each other. From the viewpoint of production efficiency and the like, it is preferable to be able to separate the heat-shrinkable film with the adhesive layer accompanying the heat-shrinkable film. Therefore, it is preferable to use the heat-shrinkable film in advance with the adhesive layer attached to the heat-shrinkable film.
【００２０】熱収縮性フィルムへの粘着層の付設は、粘
着剤を熱収縮性フィルムに塗工して乾燥処理する方式な
どにても行いうるが、その乾燥処理等による熱収縮性フ
ィルムの収縮特性の変化を防止する点などよりは、セパ
レータ上に設けた粘着層を熱収縮性フィルムに移着する
方式などが好ましい。The adhesion of the pressure-sensitive adhesive layer to the heat-shrinkable film may be performed by applying a pressure-sensitive adhesive to the heat-shrinkable film and drying the heat-shrinkable film. A method in which an adhesive layer provided on a separator is transferred to a heat-shrinkable film is more preferable than preventing a change in characteristics.
【００２１】前記の場合、セパレータはそのまま接着し
て熱収縮性フィルムを実用に供するまでの間、粘着層の
汚染等を防止する保護カバーとして利用することもでき
る。粘着層を付設する熱収縮性フィルム面には、粘着層
との密着力の向上を目的としたコロナ処理等の適宜な表
面処理を施すことができる。In the above case, the separator can be directly adhered and used as a protective cover for preventing contamination of the adhesive layer until the heat-shrinkable film is put to practical use. The surface of the heat-shrinkable film provided with the adhesive layer can be subjected to an appropriate surface treatment such as a corona treatment for the purpose of improving the adhesion to the adhesive layer.
【００２２】なお熱収縮性フィルムは、上記したように
目的とする収縮力等に応じて透光性フィルムの片面又は
両面に１枚又は２枚以上の適宜な数を接着しうるが、両
面に接着する場合や片面に複層を接着する場合には、そ
の表裏や上下における熱収縮性フィルムは、同じもので
あってもよいし、熱収縮率等の熱収縮特性が相違するも
のであってもよい。As described above, one or two or more appropriate numbers of heat-shrinkable films can be adhered to one or both surfaces of the light-transmitting film according to the desired shrinkage force or the like. When bonding or when bonding multiple layers on one side, the heat-shrinkable films on the front and back and the upper and lower sides may be the same or may have different heat-shrinkage properties such as heat-shrinkage. Is also good.
【００２３】透光性フィルムに接着した熱収縮性フィル
ムの収縮処理は、ロール延伸機やテンターや二軸延伸機
等の適宜な延伸機を介して行うことができるがその処理
温度は、透光性フィルムのガラス転移温度の近傍、就中
ガラス転移温度の±２０℃以内の温度範囲で行うことが
処理操作の制御性などの点より好ましい。またかかる点
より用いる熱収縮性フィルムは、その処理温度以下の温
度で熱収縮を開始するものが好ましい。The heat-shrinkable film adhered to the light-transmitting film can be subjected to a shrinking treatment through a suitable stretching machine such as a roll stretching machine, a tenter or a biaxial stretching machine. It is preferable to perform the treatment in the vicinity of the glass transition temperature of the functional film, especially within the temperature range of ± 20 ° C. from the viewpoint of controllability of the processing operation. From this point, it is preferable that the heat-shrinkable film used starts heat-shrinkage at a temperature lower than the processing temperature.
【００２４】加熱による熱収縮性フィルムの収縮力の作
用下に透光性フィルムに与える処理は、延伸か収縮のい
ずれかであり、形成目的の位相差フィルムに応じて適宜
に決定することができる。また与える処理は、透光性フ
ィルムの縦横方向（長さ方向と幅方向）のいずれか一方
であってもよいし、両方であってもよい。両方の方向に
処理を与える場合、一方の方向には収縮処理を、他方の
方向には延伸処理を与える組合せとすることもできる。
前記した熱収縮性フィルムの収縮力の作用下に透光性フ
ィルムに与える処理は、２回又は３回以上の工程に分け
て行うこともできる。The treatment given to the translucent film under the action of the heat-shrinkable film by the action of heat is either stretching or shrinking, and can be appropriately determined according to the retardation film to be formed. . Further, the treatment to be given may be either in the vertical and horizontal directions (length direction and width direction) of the translucent film, or may be both. When the treatment is applied in both directions, a combination in which the contraction treatment is applied in one direction and the stretching treatment is applied in the other direction may be adopted.
The treatment given to the translucent film under the action of the shrinkage force of the heat shrinkable film can be performed in two or three or more steps.
【００２５】本発明による方法は、厚さ方向の屈折率ｎ
zを制御して、フィルム面内の屈折率ｎx、ｎyの差によ
る位相差よりも、厚さ方向の屈折率ｎzが関係する方向
の位相差が大きくなる位相差フィルムの製造に有利に用
いうる。必要な処理を終えると上記した如く、形成され
た位相差フィルムより収縮処理後の熱収縮性フィルムが
剥離されてそれらが分離される。得られた位相差フィル
ムは、そのまま実用に共することもできるし、それにさ
らに延伸処理等を加えて位相差特性を調節したものとし
て実用に共することもできる。The method according to the invention provides a refractive index n in the thickness direction.
By controlling z, it can be advantageously used in the production of a retardation film in which the retardation in the direction related to the refractive index nz in the thickness direction is larger than the retardation due to the difference in refractive index nx, ny in the film plane. . After the necessary treatment, as described above, the heat-shrinkable film after the shrinkage treatment is peeled from the formed retardation film and separated therefrom. The obtained retardation film can be used for practical use as it is, or can be put to practical use as a product obtained by adjusting the retardation characteristics by further applying a stretching treatment or the like.
【００２６】本発明による好ましい位相差フィルムは、
それに限定するものではないが、複屈折による位相差と
配向軸のバラツキが可及的に小さく、就中そのフィルム
面に垂直な（正面方向の）透過光における位相差のバラ
ツキが１０nm以下、特に５nm以下で、配向軸のバラツキ
が５度以下、特に３度以下に形成されたものである。Preferred retardation films according to the present invention are:
Although not limited thereto, the phase difference due to birefringence and the variation in the orientation axis are as small as possible, and especially the variation in the phase difference in the transmitted light perpendicular to the film surface (in the front direction) is 10 nm or less, especially When the thickness is 5 nm or less, the variation of the orientation axis is 5 degrees or less, particularly 3 degrees or less.
【００２７】本発明による位相差フィルムは、その単層
物や同種又は異種の積層物などとして液晶セルの視野角
の拡大やコントラストの向上などを目的とした複屈折に
よる位相差の補償などに好ましく用いうる。その実用に
際しては、例えば位相差フィルムの片面又は両面に粘着
層を設けたものや、その粘着層を介して偏光板、又は等
方性の透明な樹脂層やガラス層等からなる保護層を接着
積層したものなどの適宜な形態の光学部材として適用す
ることもできる。The retardation film according to the present invention is preferably used as a monolayer or a laminate of the same or different kind for compensating a retardation due to birefringence for the purpose of expanding the viewing angle of a liquid crystal cell and improving contrast. Can be used. In practical use, for example, an adhesive layer is provided on one or both sides of a retardation film, or a polarizing plate, or a protective layer made of an isotropic transparent resin layer or a glass layer is bonded through the adhesive layer. It can also be applied as an optical member of an appropriate form such as a laminated one.
【００２８】前記した偏光板等との積層は、液晶表示装
置の製造過程で順次別個に積層する方式にても行いうる
が、予め積層することにより、品質の安定性や積層作業
性等に優れて液晶表示装置の製造効率を向上させうる利
点などがある。なお粘着層には、上記の熱収縮性フィル
ムの接着で例示したものなどの適宜なものを用いること
ができ、就中、耐熱性や光学特性などの点よりアクリル
系のものが好ましく用いられる。The above-mentioned lamination with a polarizing plate or the like can be carried out by a method of sequentially laminating the liquid crystal display device in the manufacturing process, but by laminating in advance, it is excellent in stability of quality and laminating workability. Therefore, there is an advantage that the manufacturing efficiency of the liquid crystal display device can be improved. As the pressure-sensitive adhesive layer, an appropriate one such as the one exemplified for the adhesion of the heat-shrinkable film can be used, and among them, an acrylic material is preferably used from the viewpoint of heat resistance and optical characteristics.
【００２９】粘着層には、必要に応じて例えば天然物や
合成物の樹脂類、ガラス繊維やガラスビーズ、金属粉や
その他の無機粉末等からなる充填剤や顔料、着色剤や酸
化防止剤などの適宜な添加剤を配合することもできる。
また微粒子を含有させて光拡散性を示す粘着層とするこ
ともできる。If necessary, the adhesive layer may contain, for example, natural or synthetic resins, fillers and pigments made of glass fibers, glass beads, metal powders and other inorganic powders, coloring agents, antioxidants and the like. Can be added.
Further, an adhesive layer exhibiting light diffusing properties can be formed by incorporating fine particles.
【００３０】位相差フィルムと積層する偏光板として
は、適宜なものを用いてよく、その例としてはポリビニ
ルアルコール系フィルムや部分ホルマール化ポリビニル
アルコール系フィルム、エチレン・酢酸ビニル共重合体
系部分ケン化フィルムの如き親水性高分子フィルムにヨ
ウ素及び／又は二色性染料を吸着させて延伸したもの、
ポリビニルアルコールの脱水処理物やポリ塩化ビニルの
脱塩酸処理物の如きポリエン配向フィルム等からなる偏
光フィルムなどがあげられる。As the polarizing plate to be laminated with the retardation film, an appropriate one may be used, and examples thereof include a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, and an ethylene / vinyl acetate copolymer partially saponified film. A film stretched by adsorbing iodine and / or a dichroic dye on a hydrophilic polymer film such as
A polarizing film made of a polyene oriented film, such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride, may be used.
【００３１】また偏光板は、前記した偏光フィルムの片
側又は両側に透明保護層を有するものであってもよい。
また偏光板は、反射層を有する反射型のものであっても
よい。反射型の偏光板は、視認側（表示側）からの入射
光を反射させて表示するタイプの液晶表示装置などを形
成するためのものであり、バックライト等の光源の内蔵
を省略できて液晶表示装置の薄型化をはかりやすいなど
の利点を有する。The polarizing plate may have a transparent protective layer on one side or both sides of the above-mentioned polarizing film.
Further, the polarizing plate may be a reflection type having a reflection layer. The reflective polarizing plate is used to form a liquid crystal display device or the like that reflects and reflects incident light from the viewing side (display side). There are advantages such as easy reduction in thickness of the display device.
【００３２】前記の透明保護層は、ポリマーの塗布層や
保護フィルムの積層物などとして適宜に形成でき、その
形成には透明性や機械的強度、熱安定性や水分遮蔽性等
に優れるポリマーなどが好ましく用いられる。その例と
してはポリエステル系樹脂やアセテート系樹脂、ポリエ
ーテルサルホン系樹脂やポリカーボネート系樹脂、ポリ
アミド系樹脂やポリイミド系樹脂、ポリオレフィン系樹
脂やアクリル系樹脂、あるいはアクリル系やウレタン
系、アクリルウレタン系やエポキシ系やシリコーン系等
の熱硬化型、ないし紫外線硬化型の樹脂などがあげられ
る。透明保護層は、微粒子の含有によりその表面が微細
凹凸構造に形成されていてもよい。The transparent protective layer can be suitably formed as a coating layer of a polymer or a laminate of a protective film. The formation of the transparent protective layer includes a polymer excellent in transparency, mechanical strength, heat stability, moisture shielding property and the like. Is preferably used. Examples thereof include polyester resins and acetate resins, polyethersulfone resins and polycarbonate resins, polyamide resins and polyimide resins, polyolefin resins and acrylic resins, or acrylic, urethane and acrylic urethane resins. Examples of such resins include thermosetting resins such as epoxy resins and silicone resins, and ultraviolet curing resins. The surface of the transparent protective layer may be formed into a fine uneven structure by containing fine particles.
【００３３】また反射型偏光板の形成は、必要に応じ透
明樹脂層等を介して偏光板の片面に金属等からなる反射
層を付設する方式などの適宜な方式で行うことができ
る。その具体例としては必要に応じマット処理した保護
フィルム等の透明樹脂層の片面に、アルミニウム等の反
射性金属からなる箔や蒸着膜を付設したものや、前記透
明樹脂層の微粒子含有による表面微細凹凸構造の上に蒸
着方式やメッキ方式等の適宜な方式で金属反射層を付設
したものなどがあげられる。The reflection type polarizing plate can be formed by an appropriate method such as a method in which a reflection layer made of metal or the like is provided on one side of the polarizing plate via a transparent resin layer or the like as necessary. Specific examples thereof include a transparent resin layer such as a protective film that has been subjected to a mat treatment as required, and a foil or a vapor-deposited film made of a reflective metal such as aluminum provided on one surface, or a surface fineness due to the inclusion of fine particles in the transparent resin layer. An example in which a metal reflective layer is provided on the concavo-convex structure by an appropriate method such as a vapor deposition method or a plating method is given.
【００３４】なお位相差フィルムと偏光板の積層に際し
て、それらの透過軸や進相軸等の光軸の配置角度につい
ては特に限定はなく、適宜に決定することができる。ち
なみにＳＴＮ型の液晶セルに適用する場合には、４５度
等の斜め交叉角に配置する場合が多く、ＴＮ型の液晶セ
ルに適用する場合には略平行又は略直交の交叉角に配置
する場合が多い。In laminating the retardation film and the polarizing plate, the arrangement angles of the optical axes such as the transmission axis and the fast axis are not particularly limited, and can be appropriately determined. Incidentally, when it is applied to STN type liquid crystal cells, it is often arranged at an oblique crossing angle such as 45 degrees, and when it is applied to TN type liquid crystal cells, it is arranged at a substantially parallel or substantially orthogonal crossing angle. There are many.
【００３５】位相差フィルムは、その２枚以上を積層し
て用いうることを上記したが、これは補償効果の向上な
どを目的とし、その場合に本発明にては本発明によるも
の以外の位相差板との積層体とすることもできる。その
位相差板としては、例えば上記の透光性フィルムで例示
のポリマーフィルムの一軸や二軸等による延伸処理物、
ディスコティック系やネマチック系等の液晶配向板など
の適宜なものを用いうる。Although it has been described above that two or more retardation films can be used by laminating them, this is for the purpose of improving the compensation effect and the like, and in this case, in the present invention, a position other than that according to the present invention is used. It can also be a laminate with a retardation plate. As the retardation plate, for example, a uniaxially or biaxially stretched polymer film exemplified by the above-mentioned light-transmitting film,
Appropriate ones such as a discotic or nematic liquid crystal alignment plate can be used.
【００３６】上記した位相差フィルムや偏光板、位相差
板や透明保護層や粘着層などの各層は、例えばサリチル
酸エステル系化合物やベンゾフェノール系化合物、ベン
ゾトリアゾール系化合物やシアノアクリレート系化合
物、ニッケル錯塩系化合物等の紫外線吸収剤で処理する
方式などにより紫外線吸収能をもたせることもできる。The above-mentioned layers such as the retardation film, the polarizing plate, the retardation plate, the transparent protective layer and the adhesive layer are made of, for example, a salicylate compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex salt. Ultraviolet absorbing ability can be provided by a method of treating with an ultraviolet absorbent such as a system compound.
【００３７】本発明による液晶表示装置は、位相差フィ
ルム又はそれを用いた光学部材を液晶セルの少なくとも
片側に有するものであり、その形成は従来に準じうる。
すなわち液晶表示装置は一般に、液晶セルと光学補償用
の位相差フィルム、及び必要に応じての偏光板や照明シ
ステム等の構成部品を適宜に組立てて駆動回路を組込む
ことなどにより形成されるが、本発明においては本発明
方法による位相差フィルムを光学補償用に用いて、それ
を液晶セルの少なくとも片側に設ける点を除いて特に限
定はなく、従来に準じうる。The liquid crystal display device according to the present invention has a retardation film or an optical member using the retardation film on at least one side of a liquid crystal cell, and its formation can be in accordance with a conventional one.
That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell and a retardation film for optical compensation, and a polarizing plate and an illumination system as needed, and incorporating a drive circuit, In the present invention, there is no particular limitation except that the retardation film according to the method of the present invention is used for optical compensation and provided on at least one side of the liquid crystal cell, and can be in accordance with the conventional method.
【００３８】従って、液晶セルの片側又は両側に偏光板
を配置した液晶表示装置や、照明システムにバックライ
トあるいは反射板を用いたものなどの適宜な液晶表示装
置を形成することができる。偏光板を用いた液晶表示装
置の場合、光学補償用の位相差フィルムは液晶セルと偏
光板、特に視認側の偏光板との間に配置することが補償
効果の点などより好ましい。その配置に際しては、上記
の光学部材としたものを用いることもできる。Therefore, an appropriate liquid crystal display device such as a liquid crystal display device in which a polarizing plate is disposed on one or both sides of a liquid crystal cell, or a lighting system using a backlight or a reflection plate can be formed. In the case of a liquid crystal display device using a polarizing plate, it is more preferable that the retardation film for optical compensation is disposed between the liquid crystal cell and the polarizing plate, particularly the polarizing plate on the viewing side, from the viewpoint of the compensation effect. In the arrangement, the optical member described above may be used.
【００３９】前記において液晶表示装置の形成部品は、
積層一体化されていてもよいし、分離状態にあってもよ
い。また液晶表示装置の形成に際しては、例えば拡散板
やアンチグレア層、反射防止膜、保護層や保護板などの
適宜な光学素子を適宜に配置することができる。In the above, the forming parts of the liquid crystal display device are as follows:
They may be laminated and integrated, or may be in a separated state. In forming a liquid crystal display device, for example, appropriate optical elements such as a diffusion plate, an antiglare layer, an antireflection film, a protective layer and a protective plate can be appropriately arranged.
【００４０】本発明による位相差フィルムや光学部材
は、視野角の拡大やコントラストの向上などの、液晶セ
ルの複屈折による位相差の補償を目的にＴＮ型やＳＴＮ
型等の複屈折を示す液晶セルを用いたＴＦＴ型やＭＩＭ
型等の種々の表示装置に好ましく用いうる。The retardation film and the optical member according to the present invention are of the TN type or STN type for the purpose of compensating for the phase difference due to the birefringence of the liquid crystal cell, such as enlarging the viewing angle and improving the contrast.
TFT or MIM using a liquid crystal cell showing birefringence such as
It can be preferably used for various display devices such as a mold.
【００４１】[0041]
【実施例】実施例１ ホスゲンとビスフェノールＡの重縮合物からなる分子量
約８万のポリカーボネートの二塩化メチレン２０重量％
溶液を、スチールドラム上に連続的に流延し、それを順
次剥取って乾燥させ、厚さ６０μmで位相差がほぼ０の
ポリカーボネートフィルムを得、そのフィルムの両面に
ＴＥＭ測定による最大ＭＤ（長さ方向）収縮率が２８％
でその際のＴＤ（幅方向）収縮率が２５％の延伸ポリプ
ロピレンフィルムをそれに付設したアクリル系粘着層を
介し接着して５０℃で２４時間加温して接着力を向上さ
せた後、延伸機を介し１６２℃でＭＤ方向５％の収縮処
理を施して延伸ポリプロピレンフィルムを剥離し、位相
差フィルムを連続して得た。EXAMPLE 1 20% by weight of methylene dichloride of polycarbonate having a molecular weight of about 80,000 and comprising a polycondensate of phosgene and bisphenol A
The solution was continuously cast on a steel drum, which was sequentially peeled off and dried to obtain a polycarbonate film having a thickness of 60 μm and a phase difference of almost 0, and a maximum MD (length) measured by TEM measurement on both surfaces of the film. 28% shrinkage
Then, a stretched polypropylene film having a TD (width direction) shrinkage rate of 25% at that time is bonded via an acrylic pressure-sensitive adhesive layer attached thereto and heated at 50 ° C. for 24 hours to improve the adhesive strength, and then a stretching machine is used. And a stretched polypropylene film was peeled off at 162 ° C. at 162 ° C. to give a retardation film continuously.
【００４２】実施例２ ５０℃、２４時間の加温処理に代えて、接着時にポリカ
ーボネートフィルムの両表面をコロナ処理することによ
り接着力を向上させ、それを収縮処理に供したほかは実
施例１に準じて位相差フィルムを得た。Example 2 Instead of heating at 50 ° C. for 24 hours, the surface of both surfaces of the polycarbonate film was corona-treated at the time of bonding to improve the bonding strength and was subjected to a shrinkage treatment. A retardation film was obtained according to the following.
【００４３】比較例１ ５０℃、２４時間の加温による接着力の向上処理を省略
したほかは実施例１に準じて位相差フィルムを得た。Comparative Example 1 A retardation film was obtained in the same manner as in Example 1 except that the treatment for improving the adhesive force by heating at 50 ° C. for 24 hours was omitted.
【００４４】比較例２ ５０℃、２４時間の加温処理に代えて、接着時にポリカ
ーボネートフィルムの両表面をコロナ処理すると共に、
その接着体を５０℃で４８時間加温して接着力を向上さ
せ、それを収縮処理に供したほかは実施例１に準じて位
相差フィルムを得た。Comparative Example 2 Instead of heating at 50 ° C. for 24 hours, corona treatment was applied to both surfaces of the polycarbonate film during bonding.
The adhesive was heated at 50 ° C. for 48 hours to improve the adhesive strength, and then subjected to a shrinkage treatment, to obtain a retardation film according to Example 1.
【００４５】評価試験 実施例、比較例の位相差フィルムを得る場合における、
加熱処理前の延伸ポリプロピレンフィルムとポリカーボ
ネートフィルムの接着力、加熱処理後における延伸ポリ
プロピレンフィルムとポリカーボネートフィルムの分離
作業性、及び得られた位相差フィルムの外観を調べた。Evaluation Test In the case of obtaining the retardation films of Examples and Comparative Examples,
The adhesive strength between the stretched polypropylene film and the polycarbonate film before the heat treatment, the workability of separating the stretched polypropylene film and the polycarbonate film after the heat treatment, and the appearance of the obtained retardation film were examined.
【００４６】前記の結果を次表に示した。 接 着 力 分離作業性 外 観 (ｇ／20mm) 実施例１ ３８．８ 容 易 良 好 実施例２ ６５ 容 易 優 良 比較例１ ２８ 容 易 発泡痕＊１ 比較例２ １０２ やや困難 糊残り＊２ ＊１：実用に供せない強度の発泡痕 ＊２：実用に供せない強度の糊残りThe above results are shown in the following table. Adhesive force Separation workability Appearance (g / 20 mm) Example 1 38.8 Easy Good Excellent Example 2 65 Easy Excellent Comparative Example 128 Easy foaming mark * 1 Comparative example 2 102 Slightly difficult Adhesive residue * 2 * 1: Foaming marks with strength that cannot be put to practical use * 2: Glue residue with strength that cannot be put to practical use
【００４７】ＴＮ型液晶セルの両側に、実施例１，２で
得た位相差フィルムを介して偏光板を配置し、正面方向
のコントラストと視角変化による表示特性を調べたとこ
ろ、コントラストに優れて広い視角範囲で表示特性に変
化はなく、視認性に優れる高表示品位の液晶表示装置で
あった。A polarizing plate was disposed on both sides of the TN type liquid crystal cell via the retardation films obtained in Examples 1 and 2, and the contrast in the front direction and the display characteristics due to the change in viewing angle were examined. There was no change in display characteristics over a wide viewing angle range, and the liquid crystal display device was high in display quality and excellent in visibility.
フロントページの続き Ｆターム(参考） 2H049 BA06 BA42 BB03 BB51 BB54 BC03 BC22 2H091 FA08X FA08Z FA11X FA11Z FB02 FB12 FC08 FC22 FD14 GA17 LA04 LA12 LA19 4F213 AC03 AD04 AD08 AG01 AH33 AH73 WA10 WB01 Continued on the front page F term (reference) 2H049 BA06 BA42 BB03 BB51 BB54 BC03 BC22 2H091 FA08X FA08Z FA11X FA11Z FB02 FB12 FC08 FC22 FD14 GA17 LA04 LA12 LA19 4F213 AC03 AD04 AD08 AG01 AH33 AH73 WA10 WB01
Claims (6)
性フィルムを接着して、加熱によるその熱収縮性フィル
ムの収縮力の作用下に透光性フィルムを少なくとも縦横
の一方向に延伸又は収縮させたのち当該熱収縮性フィル
ムを剥離して位相差フィルムを得るにあたり、前記の熱
収縮性フィルムとしてその加熱収縮前における当該透光
性フィルムとの接着力が３５〜８０ｇ／20mmのものを用
いることを特徴とする位相差フィルムの製造方法。1. A heat-shrinkable film is adhered to one or both surfaces of a light-transmitting film, and the light-transmitting film is stretched at least in one direction in a longitudinal direction or a horizontal direction under the action of shrinkage force of the heat-shrinkable film by heating. In order to obtain a retardation film by peeling the heat-shrinkable film after shrinking, the heat-shrinkable film having an adhesive force with the light-transmitting film before heat shrinkage of 35 to 80 g / 20 mm is used. A method for producing a retardation film, which is used.
粘着層を有してその粘着層を介し透光性フィルムと接着
してなる製造方法。2. The method according to claim 1, wherein the heat-shrinkable film has an adhesive layer and is bonded to the light-transmitting film via the adhesive layer.
ムとして正の複屈折特性を示すポリマーからなる長尺フ
ィルムを用いて位相差フィルムを連続に形成する製造方
法。3. The production method according to claim 1, wherein the retardation film is continuously formed using a long film made of a polymer having a positive birefringence characteristic as the light-transmitting film.
０−９Ｐａ−１以下の位相差フィルムを形成する製造方
法。4. The method according to claim 1, wherein the photoelastic coefficient is 1
0 -9 Pa -1 or less of the manufacturing method of forming a retardation film.
相差フィルムを粘着層を介して偏光板と接着したことを
特徴とする光学部材。5. An optical member, wherein the retardation film produced by the method according to claim 1 is bonded to a polarizing plate via an adhesive layer.
相差フィルム又は請求項５に記載の光学部材を液晶セル
の少なくとも片側に有することを特徴とする液晶表示装
置。6. A liquid crystal display device comprising a retardation film produced by the method according to claim 1 or the optical member according to claim 5 on at least one side of a liquid crystal cell.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11143492A JP2000329939A (en) | 1999-05-24 | 1999-05-24 | Production of phase difference film, optical member and liquid crystal display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11143492A JP2000329939A (en) | 1999-05-24 | 1999-05-24 | Production of phase difference film, optical member and liquid crystal display device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000329939A true JP2000329939A (en) | 2000-11-30 |
Family
ID=15339979
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11143492A Pending JP2000329939A (en) | 1999-05-24 | 1999-05-24 | Production of phase difference film, optical member and liquid crystal display device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000329939A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7001967B2 (en) | 2002-09-30 | 2006-02-21 | Tosoh Corporation | Transparent heat-resistant resin optical material and film |
| JP2009008998A (en) * | 2007-06-29 | 2009-01-15 | Sumitomo Chemical Co Ltd | Method for manufacturing retardation film precursor and method for manufacturing retardation film |
-
1999
- 1999-05-24 JP JP11143492A patent/JP2000329939A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7001967B2 (en) | 2002-09-30 | 2006-02-21 | Tosoh Corporation | Transparent heat-resistant resin optical material and film |
| JP2009008998A (en) * | 2007-06-29 | 2009-01-15 | Sumitomo Chemical Co Ltd | Method for manufacturing retardation film precursor and method for manufacturing retardation film |
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