JPH0511115A - Phase difference compensation plate - Google Patents
Phase difference compensation plateInfo
- Publication number
- JPH0511115A JPH0511115A JP16688991A JP16688991A JPH0511115A JP H0511115 A JPH0511115 A JP H0511115A JP 16688991 A JP16688991 A JP 16688991A JP 16688991 A JP16688991 A JP 16688991A JP H0511115 A JPH0511115 A JP H0511115A
- Authority
- JP
- Japan
- Prior art keywords
- film
- phase difference
- acid
- formula
- fluorene
- 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.)
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、液晶表示等に適用し、
位相差を補償するのに好適な位相差補償板に関するもの
である。The present invention is applied to liquid crystal displays and the like,
The present invention relates to a phase difference compensating plate suitable for compensating for a phase difference.
【０００２】[0002]
【従来の技術】近年、液晶表示装置は表示容量の増大、
画面の大型化に対応すべく、高コントラストを実現でき
るＳＴＮ（Supper Twisted Nematic）液晶をパーソナル
コンピューターやワードプロセッサーに用いている。2. Description of the Related Art In recent years, liquid crystal display devices have been increasing in display capacity,
STN (Supper Twisted Nematic) liquid crystal, which can realize high contrast, is used for personal computers and word processors in order to cope with larger screens.
【０００３】ＳＴＮ液晶を用いた表示装置は、ＳＴＮ液
晶の複屈折性による楕円偏光で、表示色か主として青色
や黄色に着色する。そのため、ＳＴＮ液晶の複屈折によ
る位相差を補償し、楕円偏光を直線偏光に戻すことによ
り、表示色を白黒表示にすることが検討されている。The display device using the STN liquid crystal is elliptically polarized light due to the birefringence of the STN liquid crystal and is colored in the display color, mainly blue or yellow. Therefore, it has been considered to compensate for the phase difference due to the birefringence of the STN liquid crystal and return the elliptically polarized light to the linearly polarized light so that the display color is displayed in black and white.
【０００４】位相差を補償する手段としては、液晶表示
セルと同じ構成で位相のみを逆位相とした補償セルを用
いるＤ−ＳＴＮ方式、複屈折性フィルムを用いるＦＴＮ
方式などがある。このうちＦＴＮ方式はＤ−ＳＴＮ方式
に比べて、軽量化、薄型化が図れ、表示セルの歩留りも
含めて望ましい表示装置である。As means for compensating for the phase difference, a D-STN system using a compensation cell having the same structure as the liquid crystal display cell but having only the opposite phase, FTN using a birefringent film is used.
There are methods. Among them, the FTN method is a preferable display device in which the weight and the thickness can be reduced as compared with the D-STN method, and the yield of display cells is also included.
【０００５】上記ＦＴＮ方式により液晶表示装置の表示
色を白黒にするには、用いられる複屈折性フィルムによ
る位相差補償板が、正面からはもとより、斜めから見た
場合にもはっきり見え、視野角に依らず位相差を補償し
得る性能を有することである。即ち、位相差補償の視野
角による性能を向上することが表示装置としてのトータ
ル性能として重要視されている。In order to make the display color of the liquid crystal display device black and white by the above-mentioned FTN method, the retardation compensating plate using the birefringent film used can be clearly seen not only from the front but also from the diagonal, and the viewing angle. That is, it has the capability of compensating for the phase difference regardless of. That is, it is important to improve the performance of the phase difference compensation depending on the viewing angle as the total performance of the display device.
【０００６】上記問題を解決する手段としては、複屈折
性フィルムの分子配向を真の一軸性に近付けることが行
われている。つまり配向方向の屈折率をｎＸ、面内でそ
れに直交する方向の屈折率をｎＹ、厚み方向の屈折率を
ｎＺとした場合、ｎＹ＝ｎＺに近付けることが、複屈折
性フィルムの製造条件として講じられている。しかし、
この方法では４５度の視野角に於て、０度（正面）と約
１０％の位相差のずれを生じてしまい、充分とはいえな
い。As a means for solving the above problems, the molecular orientation of the birefringent film is made to approach true uniaxiality. In other words, when the refractive index in the orientation direction is nX, the refractive index in the direction orthogonal to the in-plane is nY, and the refractive index in the thickness direction is nZ, approaching nY = nZ is a manufacturing condition of the birefringent film. Has been. But,
This method is not sufficient because it causes a phase difference of about 10% from 0 degree (front) at a viewing angle of 45 degrees.
【０００７】一方、ＳＴＮ液晶セルは、その光学異方性
を代表する３つの屈折率のうちの１つが他の２つの屈折
率よりも大きく、かつその大きい屈折率に対応する軸
が、表示セルの基板表面に対してほぼ水平な方向にあ
る。この光学異方体の位相差を視野角に依らず補償する
には、特開平２−４７６２９にあるように、位相差補償
板の３つの屈折率ｎＸ、ｎＹ、ｎＺのうちｎＸが他の２
つより小さい、即ち固有複屈折が負の材料であることが
必要である。On the other hand, in the STN liquid crystal cell, one of the three refractive indexes representing the optical anisotropy is larger than the other two refractive indexes, and the axis corresponding to the large refractive index is the display cell. Is almost horizontal to the substrate surface. In order to compensate for the phase difference of this optically anisotropic body regardless of the viewing angle, as described in Japanese Patent Laid-Open No. 2-47629, nX out of the three refractive indices nX, nY, and nZ of the phase difference compensating plate is the other 2.
It is necessary that the material is smaller than three, that is, the intrinsic birefringence is negative.
【０００８】すなわち、固有複屈折性が負の材料で位相
差補償板として十分な耐久性のものが得られれば、視野
角による表示品質の低下の無い理想的な表示ができる。
しかし、負の固有複屈折を有する材料としてポリメチル
メタクリル酸メチル、ポリスチレン等が従来から提案さ
れているが、いずれも耐熱性が乏しく、可撓性も不足し
ており、複屈折性フィルムとして位相差補償するには、
位相差補償性能以外の性能が不十分であった。That is, if a material having a negative intrinsic birefringence and having a sufficient durability as a retardation compensating plate can be obtained, ideal display can be performed without deterioration of display quality due to a viewing angle.
However, polymethyl methylmethacrylate, polystyrene, etc. have been conventionally proposed as materials having a negative intrinsic birefringence, but they are poor in heat resistance and lack flexibility, and thus, they are ranked as birefringent films. To compensate for the phase difference,
Performances other than the phase difference compensation performance were insufficient.
【０００９】[0009]
【発明が解決しようとする課題】本発明の目的は、耐熱
性・可撓性が十分で負の固有複屈折性を有する材料によ
り、ＳＴＮ液晶の位相差を視野角によらず補償しうる位
相差補償板を得ることである。An object of the present invention is to provide a material capable of compensating the retardation of STN liquid crystal irrespective of the viewing angle by using a material having sufficient heat resistance and flexibility and having negative intrinsic birefringence. To obtain a phase difference compensator.
【００１０】[0010]
【課題を解決するための手段】本発明の位相差補償板は
前記の点に鑑み研究を重ねた結果完成されたものであ
り、次のとおりのものである。すなわち、高分子フィル
ムもしくはシートを一軸方向に延伸してなる複屈折性フ
ィルムであって、その組成に下記（Ｉ）式で示した構造
が全体の分子量の２５から８５％含まれることを特徴と
する位相差補償板とするものである。The phase difference compensating plate of the present invention has been completed as a result of repeated studies in view of the above points, and is as follows. That is, a birefringent film obtained by uniaxially stretching a polymer film or sheet, wherein the composition has a structure represented by the following formula (I) in an amount of 25 to 85% of the total molecular weight. This is a phase difference compensator.
【００１１】[0011]
【化２】 [Chemical 2]
【００１２】（Ｉ）式で示した構造が含まれた高分子材
料としては、（Ｉ）式で示した構造が含まれる９，９−
ビス（４−アミノフェニル）−フルオレン、９，９−ビ
ス（４−ヒドロキシフェニル）−フルオレン等のモノマ
ーと塩化カルボニル、アジピン酸、セバシン酸、フタル
酸、イソフタル酸、テレフタル酸等のジカルボン酸の重
縮合で得られたポリエステルもしくはポリアミド、ある
いは９，９−ビス（４−ヒドロキシフェニル）−フルオ
レンの単独縮合で得られるポリエーテルなどが挙げられ
る。The polymer material containing the structure represented by the formula (I) includes the structure represented by the formula (I) 9,9-
Monomers of bis (4-aminophenyl) -fluorene, 9,9-bis (4-hydroxyphenyl) -fluorene, etc. and dicarboxylic acids such as carbonyl chloride, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. Examples thereof include polyesters or polyamides obtained by condensation, or polyethers obtained by condensation of 9,9-bis (4-hydroxyphenyl) -fluorene alone.
【００１３】かかる高分子材料を成膜して延伸して得ら
れる位相差補償板において、（Ｉ）式で示した構造が全
体の分子量の２５％未満の場合、ＳＴＮ液晶の位相差を
補償するのに十分な絶対値を持つ負の固有複屈折性とは
ならない。また、（Ｉ）式で示した構造が全体の分子量
の８５％を越えると（Ｉ）式で示した構造が立体障害と
なり、可撓性が不十分となり、実用に供せる強度を発揮
できない。In the retardation compensator obtained by forming and stretching such a polymer material, if the structure represented by the formula (I) is less than 25% of the total molecular weight, the retardation of the STN liquid crystal is compensated. It does not have a negative intrinsic birefringence with an absolute value sufficient for. Further, when the structure represented by the formula (I) exceeds 85% of the total molecular weight, the structure represented by the formula (I) causes steric hindrance, resulting in insufficient flexibility and failing to exhibit practical strength.
【００１４】こうして得られた高分子材料をフィルムも
しくはシートに成膜する方法としては、溶液キャスト製
膜法が好ましい。すなわち上記高分子材料を塩化メチレ
ン、クロロホルム、Ｎ−メチルピロリドン、クレゾール
等の溶剤に溶解した溶液をベルトまたはドラムの上にキ
ャスト（流延）し乾燥した後に剥離してフィルムまたは
シートを得ることである。As a method for forming the polymer material thus obtained on a film or a sheet, a solution cast film forming method is preferable. That is, a solution obtained by dissolving the above polymer material in a solvent such as methylene chloride, chloroform, N-methylpyrrolidone or cresol is cast (cast) on a belt or a drum, dried, and then peeled to obtain a film or sheet. is there.
【００１５】溶液キャスト製膜法によって得られたフィ
ルムまたはシートを延伸する方法としては、縦一軸ロー
ル延伸及び横一軸テンター延伸のいずれの方法も可能で
あり、延伸の際には一方向のみに伸ばされるようにする
ことが肝要である。As a method for stretching the film or sheet obtained by the solution cast film-forming method, either longitudinal uniaxial roll stretching or transverse uniaxial tenter stretching can be used. At the time of stretching, the film or sheet is stretched in only one direction. It is essential that the
【００１６】延伸条件としては、フィルムまたはシート
の温度については高分子材料の組成によって変わるが１
３０℃から３７０℃、また延伸倍率については１．１倍
から２．０倍が好ましい。Regarding the stretching conditions, the temperature of the film or sheet varies depending on the composition of the polymer material, but 1
30 ° C. to 370 ° C., and the draw ratio is preferably 1.1 times to 2.0 times.
【００１７】前述の位相差補償板を構成する高分子材料
の分子量としては、重量平均分子量が２×１０4 から１
×１０5 の範囲にあるものが好ましい。重量平均分子量
が２×１０4 未満であると成膜した後のフィルムもしく
はシートとしての強度が小さくなり、また１×１０5 を
越えると溶液キャストの際の粘度が著しく高くなるため
製膜が難しくなる。Regarding the molecular weight of the polymer material constituting the above-mentioned retardation compensating plate, the weight average molecular weight is from 2 × 10 4 to 1
Those in the range of × 10 5 are preferable. If the weight average molecular weight is less than 2 × 10 4 , the strength of the film or sheet after film formation will be low, and if it exceeds 1 × 10 5 , the viscosity during solution casting will be extremely high, making film formation difficult. Become.
【００１８】以上のようにして得られた位相差補償板を
液晶セルに保持する手段としては、位相差補償板の上に
積層される偏光板の応力を緩和するために粘着剤である
必要があり、透明性及び耐久性を鑑みた場合、ｎ−ブチ
ルアクリレートもしくは２ーエチルヘキシルアクリレー
トのごときアクリルモノマーを主モノマーとするアクリ
ル系粘着剤が最も好ましい。As a means for holding the retardation compensating plate thus obtained in the liquid crystal cell, it is necessary to use an adhesive in order to relieve the stress of the polarizing plate laminated on the retardation compensating plate. In consideration of transparency and durability, an acrylic pressure-sensitive adhesive containing an acrylic monomer as a main monomer, such as n-butyl acrylate or 2-ethylhexyl acrylate, is most preferable.
【００１９】[0019]
【実施例】以下、実施例によりさらに詳しく説明する。
実施例１
９，９−ビス（４−ヒドロキシフェニル）−フルオレン
モノマーとアジピン酸の重縮合で得られた重量平均分子
量が８×１０4 のポリエステルを、塩化メチレンに溶解
して２０重量％の溶液を作製し、ベルト上に塗布・乾燥
して得られた厚み１００μのフィルムを、縦一軸ロール
延伸機で延伸温度２４５℃、延伸倍率１．６倍に延伸し
た。EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1 A 20% by weight solution of a polyester having a weight average molecular weight of 8 × 10 4 obtained by polycondensation of 9,9-bis (4-hydroxyphenyl) -fluorene monomer and adipic acid in methylene chloride was prepared. A film having a thickness of 100 μm, which was prepared by applying the above-mentioned method to a belt and drying it, was drawn by a longitudinal uniaxial roll drawing machine at a drawing temperature of 245 ° C. and a draw ratio of 1.6 times.
【００２０】得られたフィルムを、アッベの屈折計で５
８９．３ｎｍにおける延伸方向の屈折率ｎＸ、面内でそ
れに直交する方向の屈折率ｎＹ、厚み方向の屈折率ｎＺ
の測定を行った。また、可撓性の評価として、得られた
フィルムを１８０度折り曲げたときのフィルムの状態を
評価した。さらに、得られたフィルムの片面にｎ−ブチ
ルアクリレートを主モノマーとするアクリル系粘着剤を
設けて透明なガラス板に貼り合わせた後に１００℃のギ
アオーブンに放置して、放置前と５００時間放置後の５
８９．３ｎｍにおける位相差を比較することによって耐
熱性の評価とした。以上の結果を表１にまとめた。The obtained film was measured with an Abbe's refractometer.
Refractive index nX in the stretching direction at 89.3 nm, refractive index nY in the direction orthogonal to it in the plane, refractive index nZ in the thickness direction
Was measured. Moreover, as the evaluation of flexibility, the state of the film when the obtained film was bent 180 degrees was evaluated. Furthermore, an acrylic pressure-sensitive adhesive containing n-butyl acrylate as a main monomer was provided on one surface of the obtained film, and the film was pasted on a transparent glass plate and then left in a gear oven at 100 ° C. 5 after
The heat resistance was evaluated by comparing the phase difference at 89.3 nm. The above results are summarized in Table 1.
【００２１】表１から、実施例１のフィルムが負の固有
複屈折性を示し、可撓性があり、耐熱性に優れているこ
とがわかる。
実施例２
９，９−ビス（４−アミノフェニル）−フルオレンモノ
マーとセバシン酸の重縮合で得られた重量平均分子量が
５×１０4 のポリアミドを、塩化メチレンに溶解して２
５重量％の溶液を作製し、ベルト上に塗布・乾燥して得
られた厚み７０μのフィルムを、縦一軸ロール延伸機で
延伸温度２８５℃、延伸倍率１．８倍に延伸した。From Table 1, it can be seen that the film of Example 1 exhibits negative intrinsic birefringence, is flexible, and is excellent in heat resistance. Example 2 A polyamide having a weight average molecular weight of 5 × 10 4 obtained by polycondensation of 9,9-bis (4-aminophenyl) -fluorene monomer and sebacic acid was dissolved in methylene chloride to give 2
A 70% thick film obtained by preparing a 5% by weight solution, applying the solution on a belt and drying it was stretched by a longitudinal uniaxial roll stretching machine at a stretching temperature of 285 ° C. and a stretching ratio of 1.8 times.
【００２２】得られたフィルムについて、実施例１と同
様にして位相差補償板としての性能評価を行った。表１
から、実施例２のフィルムが負の固有複屈折性を示し、
可撓性があり、耐熱性に優れていることがわかる。
比較例１
ラジカル重合によって得られた重量平均分子量４×１０
5 のスチレン樹脂を、塩化メチレンに溶解して３０重量
％の溶液を作製し、ベルト上に塗布・乾燥して得られた
厚み１００μのフィルムを、縦一軸ロール延伸機で延伸
温度１００℃、延伸倍率１．６倍に延伸した。The performance of the obtained film as a retardation compensating plate was evaluated in the same manner as in Example 1. Table 1
Therefore, the film of Example 2 exhibits negative intrinsic birefringence,
It can be seen that it is flexible and has excellent heat resistance. Comparative Example 1 Weight average molecular weight 4 × 10 obtained by radical polymerization
The styrene resin of 5 was dissolved in methylene chloride to prepare a 30 wt% solution, and the film having a thickness of 100 μ obtained by coating and drying on a belt was stretched at a stretching temperature of 100 ° C. by a vertical uniaxial stretching machine. It was stretched to a draw ratio of 1.6 times.
【００２３】得られたフィルムについて、実施例１と同
様にして位相差補償板としての性能評価を行った。The performance of the obtained film as a retardation compensating plate was evaluated in the same manner as in Example 1.
【００２４】[0024]
【表１】 [Table 1]
【００２５】表１の結果から明らかなとおり、固有複屈
折性が負となる位相差補償板において、実施例の位相差
補償板が、比較例など従来の位相差補償板に比べて、耐
熱性と可撓性を著しく向上している。As is clear from the results shown in Table 1, in the retardation compensating plate having a negative intrinsic birefringence, the retardation compensating plate of the example is more heat resistant than the conventional retardation compensating plate of the comparative example. And the flexibility is significantly improved.
【００２６】[0026]
【発明の効果】本発明の位相差補償板は、負の固有複屈
折性を示し、しかも可撓性、耐熱性に優れている。した
がって、本発明によって得られた位相差補償板を用いる
ことにより、視野角による位相差変化の限りなく少ない
ＳＴＮ液晶の設計が可能となる。The retardation compensating plate of the present invention exhibits negative intrinsic birefringence, and is excellent in flexibility and heat resistance. Therefore, by using the phase difference compensating plate obtained by the present invention, it is possible to design the STN liquid crystal in which the phase difference change depending on the viewing angle is extremely small.
Claims (3)
向に延伸してなる複屈折性フィルムであって、その組成
に（Ｉ）式で示した構造が全体の分子量の２５から８５
％含まれることを特徴とする位相差補償板。 【化１】 1. A birefringent film obtained by uniaxially stretching a polymer film or sheet, wherein the structure represented by the formula (I) has a total molecular weight of 25 to 85.
% Of the phase difference compensating plate. [Chemical 1]
０5の範囲にある高分子フィルムもしくはシートを一軸
方向に延伸してなる請求項１記載の位相差補償板。2. A weight average molecular weight of 2 × 10 4 to 1 × 1.
The retardation compensating plate according to claim 1, which is obtained by uniaxially stretching a polymer film or sheet in the range of 0 5 .
クリル系粘着剤を設けてなる請求項１記載の位相差補償
板。3. The retardation compensating plate according to claim 1, wherein an acrylic pressure-sensitive adhesive is provided on at least one surface of the birefringent film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16688991A JPH0511115A (en) | 1991-07-08 | 1991-07-08 | Phase difference compensation plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16688991A JPH0511115A (en) | 1991-07-08 | 1991-07-08 | Phase difference compensation plate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0511115A true JPH0511115A (en) | 1993-01-19 |
Family
ID=15839506
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16688991A Pending JPH0511115A (en) | 1991-07-08 | 1991-07-08 | Phase difference compensation plate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0511115A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994012910A1 (en) * | 1992-11-27 | 1994-06-09 | Allied-Signal Inc. | Unsymmetrically substituted fluorenes for non-linear optical applications |
| JP2001249222A (en) * | 2000-03-02 | 2001-09-14 | Teijin Ltd | Antireflection film and light emitting display element using the same |
| US6379590B1 (en) | 1994-12-02 | 2002-04-30 | Alliedsignal Inc. | Method for making unsymmetrically substituted fluorenyl compounds for nonlinear optical applications |
| JP2006215064A (en) * | 2005-02-01 | 2006-08-17 | Teijin Chem Ltd | Retardation film |
-
1991
- 1991-07-08 JP JP16688991A patent/JPH0511115A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994012910A1 (en) * | 1992-11-27 | 1994-06-09 | Allied-Signal Inc. | Unsymmetrically substituted fluorenes for non-linear optical applications |
| US6379590B1 (en) | 1994-12-02 | 2002-04-30 | Alliedsignal Inc. | Method for making unsymmetrically substituted fluorenyl compounds for nonlinear optical applications |
| JP2001249222A (en) * | 2000-03-02 | 2001-09-14 | Teijin Ltd | Antireflection film and light emitting display element using the same |
| JP2006215064A (en) * | 2005-02-01 | 2006-08-17 | Teijin Chem Ltd | Retardation film |
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