JPH04284402A - Novel phase difference compensation sheet - Google Patents
Novel phase difference compensation sheetInfo
- Publication number
- JPH04284402A JPH04284402A JP4955191A JP4955191A JPH04284402A JP H04284402 A JPH04284402 A JP H04284402A JP 4955191 A JP4955191 A JP 4955191A JP 4955191 A JP4955191 A JP 4955191A JP H04284402 A JPH04284402 A JP H04284402A
- Authority
- JP
- Japan
- Prior art keywords
- sheet
- retardation
- liquid crystal
- stretching
- orienting
- 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.)
- Withdrawn
Links
- 229920000642 polymer Polymers 0.000 claims abstract description 19
- WSSSPWUEQFSQQG-UHFFFAOYSA-N 4-methyl-1-pentene Chemical compound CC(C)CC=C WSSSPWUEQFSQQG-UHFFFAOYSA-N 0.000 claims description 9
- 239000004973 liquid crystal related substance Substances 0.000 abstract description 26
- 238000004132 cross linking Methods 0.000 abstract description 6
- 229920001577 copolymer Polymers 0.000 description 10
- 238000000034 method Methods 0.000 description 8
- 230000003287 optical effect Effects 0.000 description 8
- 230000007423 decrease Effects 0.000 description 7
- 210000002858 crystal cell Anatomy 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 229920005989 resin Polymers 0.000 description 5
- 239000011347 resin Substances 0.000 description 5
- 238000010894 electron beam technology Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000000465 moulding Methods 0.000 description 4
- 229920005992 thermoplastic resin Polymers 0.000 description 4
- 238000002834 transmittance Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- -1 ethylene, propylene, butene Chemical class 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- YWAKXRMUMFPDSH-UHFFFAOYSA-N pentene Chemical compound CCCC=C YWAKXRMUMFPDSH-UHFFFAOYSA-N 0.000 description 3
- 229920000098 polyolefin Polymers 0.000 description 3
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 210000004027 cell Anatomy 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 229920003002 synthetic resin Polymers 0.000 description 2
- 239000000057 synthetic resin Substances 0.000 description 2
- BJELTSYBAHKXRW-UHFFFAOYSA-N 2,4,6-triallyloxy-1,3,5-triazine Chemical compound C=CCOC1=NC(OCC=C)=NC(OCC=C)=N1 BJELTSYBAHKXRW-UHFFFAOYSA-N 0.000 description 1
- 239000004988 Nematic liquid crystal Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000004711 α-olefin Substances 0.000 description 1
Landscapes
- Polarising Elements (AREA)
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、液晶表示装置に用いら
れる位相差補償シートに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retardation compensation sheet used in liquid crystal display devices.
【０００２】0002
【従来の技術】ＳＴＮ（Ｓｕｐｅｒ Ｔｗｉｓｔｅｄ
Ｎｅｍａｔｉｃ）の液晶ディスプレイにおいて白黒
表示を実現するためには、ＳＴＮ液晶の複屈折性による
着色を除く必要性がある。この方法として、光学補償用
の液晶セルをさらに重ねて液晶の着色を消す２層セル方
式が実用化されているが、光学補償用液晶セルは高価で
あり、また装置が厚く重くなり、光線の透過率が低下し
、より強い光源を必要とするなどの欠点を有する。[Prior Art] STN (Super Twisted
In order to realize black and white display in a nematic liquid crystal display, it is necessary to remove coloration due to birefringence of STN liquid crystal. As a method for this purpose, a two-layer cell method has been put into practical use that eliminates the coloring of the liquid crystal by layering another liquid crystal cell for optical compensation, but the liquid crystal cell for optical compensation is expensive, and the device is thick and heavy, and the light rays are It has drawbacks such as reduced transmittance and the need for a stronger light source.
【０００３】このような２層セル方式の欠点を解決する
方法として、光学補償用の液晶セルと同等の光学的特性
をもった高分子シートで置き換える方法があるが、この
様な光学特性をもった高分子シート（以後、位相差補償
シートと呼ぶ）は、複屈折特性を持ち透明度の高いシー
トであることが必要である。従来の位相差補償シートの
製造方法としては、ベースとなるシートを加熱後又は、
加熱しながら引張延伸法等で延伸成形することによって
作られる。One way to solve these drawbacks of the two-layer cell system is to replace it with a polymer sheet that has optical properties equivalent to those of the liquid crystal cell for optical compensation. The polymer sheet (hereinafter referred to as a retardation compensating sheet) needs to have birefringent properties and high transparency. Conventional methods for manufacturing retardation compensation sheets include heating the base sheet or
It is made by stretching and molding using a tensile stretching method or the like while heating.
【０００４】縦方向と横方向の延伸割合の差で光の複屈
折率差（△ｎ）を持たせる。これに、シートの厚みｄを
掛けた数値、レターデーションＲ＝△ｎ・ｄを補償する
液晶セルと同じに合わせる。これまで、合成樹脂の異方
性配向シートから成る位相差補償シートについては、各
種合成樹脂について報告されており、例えば、ポリカー
ボネート樹脂の補償シートについては、特開昭６３−１
８９８０４号、特開昭５６−１３０７０３号、特開昭６
３−２６１３０２号各公報等に報告されている。[0004] A difference in the birefringence of light (Δn) is provided by the difference in stretching ratio in the longitudinal direction and the transverse direction. This value is multiplied by the thickness d of the sheet, and the retardation R=Δn·d is set to be the same as that of the liquid crystal cell to be compensated. Until now, retardation compensation sheets made of anisotropically oriented synthetic resin sheets have been reported for various synthetic resins.
No. 89804, JP-A-56-130703, JP-A-6
It is reported in various publications such as No. 3-261302.
【０００５】更に、ポリオレフィンからなる位相差補償
シートについては、特開昭６０−２４５０２号公報に報
告されている。これ等の既に報告されている位相差補償
シートでは未だ満足されていない性質がいくつかあるが
、最近特に要求されている特性は、液晶の光学特性の温
度変化と類似の性質を有する位相差補償シートである。Furthermore, a retardation compensating sheet made of polyolefin is reported in Japanese Patent Laid-Open No. 60-24502. There are some properties that are not yet satisfied with these retardation compensation sheets that have already been reported, but the properties that have been particularly required recently are retardation compensation sheets that have properties similar to the temperature change in the optical properties of liquid crystals. It is a sheet.
【０００６】すなわち、液晶の複屈折の温度変化と、位
相差補償シートの複屈折の温度変化が似ていることが要
求されている。液晶は温度の上昇によりレターデーショ
ンがかなり大きく低下するため、同様な傾向を示す位相
差補償シートが要求されている。これが達成できれば、
広い温度範囲で、コントラスト比の高い良好な液晶表示
ができる。That is, it is required that the temperature change in the birefringence of the liquid crystal and the temperature change in the birefringence of the retardation compensating sheet be similar. Since the retardation of liquid crystals decreases considerably as the temperature rises, there is a need for a retardation compensating sheet that exhibits a similar tendency. If this can be achieved,
Good liquid crystal display with high contrast ratio is possible over a wide temperature range.
【０００７】又、上記の位相差補償シートは、該位相差
補償シートに対して垂直に見た場合の位相差を補償する
ものであるが、液晶で発生する位相差は、液晶セル及び
位相差補償シートに対して垂直に見た場合と、斜めに見
た場合とで異なる。即ち、液晶セル及び位相差補償シー
トに対して垂直に見ても、斜めに見ても、同様に位相差
補償がなされることが好ましい。現状ではこれに差を生
じてしまっている問題がある。本発明はシート面方向に
は均一多軸配向されており、シート厚み方向の屈折率の
みを変化させた視野角を広げる位相差補償シートにも係
る。[0007]Also, the above-mentioned retardation compensating sheet compensates for the retardation when viewed perpendicularly to the retardation compensating sheet, but the retardation generated in the liquid crystal is It differs when viewed perpendicularly to the compensation sheet and when viewed diagonally. That is, it is preferable that the retardation compensation is performed in the same way whether viewed perpendicularly or obliquely to the liquid crystal cell and the retardation compensation sheet. At present, there is a problem that is causing this difference. The present invention also relates to a retardation compensation sheet that is uniformly multiaxially oriented in the sheet surface direction and widens the viewing angle by changing only the refractive index in the sheet thickness direction.
【０００８】[0008]
【発明が解決すべき課題】本発明の目的は、上記のよう
な問題点を解決した良好な複屈折特性をもった位相差補
償シートを提供することである。SUMMARY OF THE INVENTION An object of the present invention is to provide a retardation compensation sheet having good birefringence properties that solves the above-mentioned problems.
【０００９】[0009]
【課題を解決するための手段】本発明は、４−メチルペ
ンテン−１を主体とした重合体を延伸配向せしめた位相
差補償シートである。すなわち、異方性配向あるいは均
一多軸配向せしめた上記シートであり、更に架橋した後
に延伸配向せしめた上記シートである。以下に本発明に
ついて詳細に説明する。[Means for Solving the Problems] The present invention is a retardation compensating sheet in which a polymer mainly composed of 4-methylpentene-1 is stretched and oriented. That is, the above sheet is anisotropically oriented or uniformly multiaxially oriented, and the above sheet is further crosslinked and then stretch oriented. The present invention will be explained in detail below.
【００１０】本発明者らは、各種ポリマーを用いて、延
伸配向シートを試作したところ、４−メチルペンテン−
１を主体とした重合体の延伸配向シートは、レターデー
ションの温度変化が大きく、ＳＴＮ液晶のレターデーシ
ョンの温度変化に合わせるには好適であることを発見し
本発明に到った。本発明に述べるシートとは、シートあ
るいはフィルムを意味し、一般には０．００５〜２ｍｍ
厚程度のシートであり、好ましくは０．０２〜１ｍｍ厚
である。[0010] The inventors of the present invention trial-produced stretched oriented sheets using various polymers, and found that 4-methylpentene-
It was discovered that a stretched or oriented sheet of a polymer mainly composed of 1 has a large change in retardation with temperature, and is suitable for adjusting to the change in retardation of STN liquid crystal with temperature, leading to the present invention. The sheet mentioned in the present invention means a sheet or a film, and generally has a thickness of 0.005 to 2 mm.
The sheet is approximately thick, preferably 0.02 to 1 mm thick.
【００１１】本発明に述べる４−メチルペンテン−１を
主体とした重合体とは、４−メチルペンテン−１が５０
重量％以上、好ましくは６０重量％以上、更に好ましく
は７０重量％以上含まれた重合体であり、ホモポリマー
、コポリマー、ブレンド等必要に応じて選択できる。
４−メチルペンテン−１と共重合されるモノマーは、エ
チレン、プロピレン、ブテン、ペンテン、ヘキセン−１
、スチレン、Ｃ５ 〜Ｃ１８のα−オレフィンが良好に
使用できる。ペンテン−１とのコポリマーは、ペンテン
−１含有量が２７％で全光線透過率は９４％となる。[0011] The polymer mainly composed of 4-methylpentene-1 described in the present invention refers to a polymer mainly composed of 4-methylpentene-1.
It is a polymer containing at least 60% by weight, more preferably at least 70% by weight, and can be selected from homopolymers, copolymers, blends, etc. as necessary. Monomers copolymerized with 4-methylpentene-1 include ethylene, propylene, butene, pentene, and hexene-1.
, styrene, and C5 to C18 α-olefins can be used satisfactorily. A copolymer with pentene-1 has a pentene-1 content of 27% and a total light transmittance of 94%.
【００１２】共重合体は共重合成分の増加により、非結
晶成分が増加し、融点も低下する。ポリ−４−メチルペ
ンテン−１の融点は２３５℃であるが、１９．３％ヘキ
セン−１含有共重合体の融点は２１７℃まで低下する。
本発明では共重合ブレンド共に、樹脂の全光線透過率が
大巾に低下しない範囲で使用できる。本発明のシートは
全光線透過率が８０％以上であることが好ましい。又、
延伸配向されたシートは加熱収縮を開始する温度が６０
℃以上、好ましくは７０℃以上であることが好ましく、
この範囲で共重合成分及びその量、ブレンド成分及びそ
の量が選択される。本発明シートの成形上からは、若干
の共重合成分を配合して、成形加工性を向上し、更にシ
ートの透明度を向上させた共重合体が好ましい。[0012] As the copolymerization component increases, the amorphous component increases and the melting point of the copolymer also decreases. The melting point of poly-4-methylpentene-1 is 235°C, while the melting point of the copolymer containing 19.3% hexene-1 decreases to 217°C. In the present invention, both copolymer blends can be used as long as the total light transmittance of the resin does not decrease significantly. The sheet of the present invention preferably has a total light transmittance of 80% or more. or,
The temperature at which the stretched and oriented sheet starts to shrink when heated is 60°C.
℃ or higher, preferably 70℃ or higher,
The copolymer component and its amount, and the blend component and its amount are selected within this range. From the viewpoint of forming the sheet of the present invention, it is preferable to use a copolymer that is blended with some copolymer components to improve molding processability and further improve the transparency of the sheet.
【００１３】本発明に述べる延伸配向された配向シート
とは、一軸方向、二軸方向、あるいは多軸方向に配向し
たシートを言い、異方性配向シートは後述の方法で求め
たＤ（主配向方向での延伸倍率）とｄ（主配向方向に垂
直な方向での延伸倍率）が等しくない。主配向方向とは
シート面内で延伸倍率が最大な方向である。この主配向
方向を求める方法は図１（ａ）に示した様に、延伸後の
シートに円及びその中心Ｏを描き、そのシートを加熱収
縮させた後の図形、同図（ｂ）において、中心からの距
離が最小になる点Ｐと中心Ｏを結ぶ直線ＯＰの方向が主
配向方向である。The stretched oriented sheet described in the present invention refers to a sheet oriented in a uniaxial direction, biaxial direction, or multiaxial direction, and an anisotropically oriented sheet has a D (main orientation) determined by the method described below. (stretching ratio in the direction) and d (stretching ratio in the direction perpendicular to the main orientation direction) are not equal. The main orientation direction is the direction in which the stretching ratio is maximum within the sheet plane. The method for determining this main orientation direction is as shown in Figure 1(a), by drawing a circle and its center O on the stretched sheet, and then drawing the shape after heating and shrinking the sheet, as shown in Figure 1(b). The direction of the straight line OP connecting the point P with the minimum distance from the center and the center O is the main orientation direction.
【００１４】主配向方向での延伸倍率Ｄの平均値Ｄ、主
配向方向に垂直な方向での延伸倍率ｄの平均値ｄの求め
方は次の様である。図２（ａ）に示した様に、主配向方
向に平行及び垂直な方向に辺を持つ長方形の試験片を作
り、この上に主配向方向に平行及び垂直な線分を等間隔
に各１０本以上描く。そしてこのシートを加熱収縮させ
た後の図形、同図（ｂ）各線分の長さで収縮前の線分の
長さを割ることにより各線分におけるＤ及びｄが求める
。The average value D of the stretching ratio D in the main orientation direction and the average value d of the stretching ratio d in the direction perpendicular to the main orientation direction are determined as follows. As shown in Fig. 2(a), a rectangular test piece with sides parallel and perpendicular to the main orientation direction is made, and 10 line segments parallel and perpendicular to the main orientation direction are placed on this specimen at equal intervals. I draw more than books. The figure after the sheet is heated and shrunk is shown in Figure (b). By dividing the length of the line segment before shrinkage by the length of each line segment, D and d for each line segment are determined.
【００１５】すなわち、
Ｄｎ＝Ａｎ Ｂｎ／Ａ′ｎＢ′ｎ（ｎ＝１〜１０）ｄ
ｎ ＝ａｎ ｂｎ ／ａ′ｎ ｂ′ｎ （ｎ＝１〜
８）及び
ｄ９ ＝Ａ１ Ａ１０／Ａ′１ Ａ′１０ 、ｄ１０
＝Ｂ１ Ｂ１０／Ｂ′１ Ｂ′１０ 、である。こう
して求めたＤ、ｄの平均値がＤ（ａｖ）、ｄ（ａｖ）で
ある。That is, Dn=An Bn/A'nB'n (n=1 to 10) d
n = an bn /a'n b'n (n=1~
8) and d9 = A1 A10/A'1 A'10, d10
=B1 B10/B'1 B'10. The average values of D and d thus obtained are D(av) and d(av).
【００１６】本発明の異方性配向シートにおいて、一軸
方向に配向されたシートとは、Ｄ（ａｖ）＞１．０かつ
ｄ（ａｖ）＝１．０のものをいい、二軸方向に配向され
たシートとは、Ｄ（ａｖ）＞１．０かつｄ（ｓｖ）＞１
．０のものをいう。本発明において、異方性配向シート
はＤ（ａｖ）／ｄ（ａｖ）の値が、１．１≦Ｄ（ａｖ）
／ｄ（ａｖ）≦１０．０を満たすことが好ましい。
Ｄ（ａｖ）／ｄ（ａｖ）＜１．１では異方性配向シート
とならず、Ｄ（ａｖ）／ｄ（ａｖ）＞１０．０において
は均一に延伸することが困難になる。In the anisotropically oriented sheet of the present invention, the uniaxially oriented sheet refers to a sheet oriented in the biaxial direction, where D(av)>1.0 and d(av)=1.0. A sheet with D(av)>1.0 and d(sv)>1
．． 0. In the present invention, the anisotropically oriented sheet has a value of D(av)/d(av) of 1.1≦D(av).
It is preferable to satisfy /d(av)≦10.0. If D(av)/d(av)<1.1, an anisotropically oriented sheet will not be obtained, and if D(av)/d(av)>10.0, it will be difficult to stretch uniformly.
【００１７】更に好ましくは、１．３≦Ｄ（ａｖ）／ｄ
（ａｖ）≦８．０であり、最も好ましくは、１．５≦Ｄ
（ａｖ）／ｄ（ａｖ）≦６．０である。本発明の均一多
軸配向シートとは、該シートの厚みをｄ、該シートの平
面（Ｘ−Ｙ平面）上の各方向の最大の屈折率をｎｍａｘ
、最小の屈折率をｎｍｉｎ、該シートの厚み方向（Ｚ
方向）の屈折率をｎｚ とすると、
を満たす光学シートである。好ましくは、値の１０倍以
上、更に好ましくは１５倍以上である。More preferably, 1.3≦D(av)/d
(av)≦8.0, most preferably 1.5≦D
(av)/d(av)≦6.0. The uniform multiaxially oriented sheet of the present invention means that the thickness of the sheet is d, and the maximum refractive index in each direction on the plane (X-Y plane) of the sheet is nmax.
, the minimum refractive index is nmin, the thickness direction of the sheet (Z
When the refractive index in the direction) is nz, the optical sheet satisfies the following. Preferably, it is 10 times or more, more preferably 15 times or more.
【００１８】本発明では延伸配向する前に架橋すること
により、更に良好な本発明シートが得られる。すなわち
、架橋された熱可塑性樹脂は延伸成形の際の加熱温度に
差が生じても、延伸倍率及び異方性が等しければ、分子
の配向度に差が生じにくい。これに対して未架橋の溶融
成形可能な樹脂の場合、分子差の絡みが少なく、延伸時
にすぬけが生じやすく、延伸成形の際の加熱温度に差が
生じたとき、延伸倍率異方性が等しくても、分子の配向
度に差が生じやすい。この結果、均一な配向度をもった
配向シートを得ようとしたとき、未架橋熱可塑性樹脂の
場合に比べ、架橋された熱可塑性樹脂は容易となる。In the present invention, an even better sheet of the present invention can be obtained by crosslinking before stretching and orientation. That is, even if there is a difference in the heating temperature during stretch-molding of crosslinked thermoplastic resins, as long as the stretching ratio and anisotropy are the same, the degree of molecular orientation is unlikely to differ. On the other hand, in the case of uncrosslinked melt-moldable resins, there are fewer entanglements of molecular differences, which tends to cause slippage during stretching, and when a difference occurs in the heating temperature during stretch-molding, the stretch ratio anisotropy decreases. Even if they are equal, a difference tends to occur in the degree of molecular orientation. As a result, when trying to obtain an oriented sheet with a uniform degree of orientation, it is easier to obtain an oriented sheet with a crosslinked thermoplastic resin than with an uncrosslinked thermoplastic resin.
【００１９】本発明のシートを延伸するに先立ち、架橋
シートを成形する。無架橋の熱可塑性樹脂を押出成形等
の方法でシートを成形し、該シートに電子線等を照射し
て架橋する方法は良好に使用できる。電子線による架橋
を良好に行わせるため、４−メチルペンテン−１を主体
とした重合体にはトリアリルシアヌレート等の架橋促進
剤を配合することが好ましい。Prior to stretching the sheet of the present invention, a crosslinked sheet is formed. A method of forming a sheet from a non-crosslinked thermoplastic resin by extrusion molding or the like and crosslinking the sheet by irradiating the sheet with an electron beam or the like can be used favorably. In order to achieve good crosslinking by electron beams, it is preferable to mix a crosslinking accelerator such as triallyl cyanurate with the polymer mainly composed of 4-methylpentene-1.
【００２０】好ましい架橋は、押出成形によりシート状
に成形されたシートに電子線等を照射して、ゲル分率１
〜９０重量％に架橋したシートである。ここに述べるゲ
ル分率とは室温で樹脂の溶剤に溶解した後に、不溶分と
して残るゲル成分の割合である。ゲル分率は樹脂の種類
、シートの厚さ、電子線の照射量により調節できる。
ゲル分率が９０重量％を越えると延伸配向が困難になり
、ゲル分率が１重量％以下では効果が少く好ましくは５
〜８０重量％、更に好ましくは１０〜６０重量％である
。[0020] Preferred crosslinking is carried out by irradiating a sheet formed into a sheet by extrusion molding with an electron beam or the like to increase the gel fraction to 1.
The sheet is crosslinked to ~90% by weight. The gel fraction described herein is the proportion of gel components that remain as insoluble components after being dissolved in a resin solvent at room temperature. The gel fraction can be adjusted by the type of resin, the thickness of the sheet, and the amount of electron beam irradiation. If the gel fraction exceeds 90% by weight, stretching orientation becomes difficult, and if the gel fraction is less than 1% by weight, the effect is small, and preferably 5% by weight or less.
~80% by weight, more preferably 10-60% by weight.
【００２１】配向シートのレターデーションの温度変化
率は素材ポリマーの分子構造に依存し、温度と分子運動
の関係が大きく作用する。４−メチルペンテン−１を主
体とする重合体からなる配向シートが、ＳＴＮ液晶と同
じ負のレターデーション温度変化率を示す理由は、この
様な大きな側鎖をもつポリマーは、延伸すると、主鎖と
側鎖の分極率の異方性により、延伸軸方向の屈折率（Ｎ
ｘ）がこれに直角方向の屈折率（Ｎｙ）に比べ小さい負
の１軸性を示すが、Ｎｙの大きさを決定する主因子であ
る側鎖のメチル基が室温域で回転可能なため、ガラス転
移点以下で、温度の上昇と共にＮｘは変わらず、Ｎｙだ
けが小さくなり、面内主屈折率差（△ｎ＝Ｎｙ−Ｎｘ）
が温度上昇と共に小さくなるからであると考えられる。The temperature change rate of the retardation of the oriented sheet depends on the molecular structure of the polymer material, and is largely influenced by the relationship between temperature and molecular motion. The reason why an oriented sheet made of a polymer mainly composed of 4-methylpentene-1 exhibits the same negative retardation temperature change rate as STN liquid crystal is that when a polymer with such large side chains is stretched, the main chain The refractive index (N
x) exhibits a smaller negative uniaxiality than the refractive index (Ny) in the direction perpendicular to this, but since the methyl group in the side chain, which is the main factor determining the size of Ny, is rotatable at room temperature, Below the glass transition point, as the temperature rises, Nx does not change, only Ny decreases, and the in-plane principal refractive index difference (△n = Ny - Nx)
This is thought to be because the value decreases as the temperature rises.
【００２２】ポリマーのブレンド比、或いは重合比は、
配向シートを位相差補償シートにした際のレターデーシ
ョン値、及びその使用形態で異なり、位相差補償シート
を１枚構成で用いる場合は、１枚で、複数構成で用いる
場合は複数重ねた状態で、レターデーションの温度変化
率が光学補償するＳＴＮ液晶セルの特性にほぼ合うよう
に最適に設定されることが好ましい。[0022] The blend ratio or polymerization ratio of the polymer is
The retardation value when the orientation sheet is used as a retardation compensating sheet and its usage form vary. When using a retardation sheet in a single configuration, it is used as a single sheet, and when used in a multiple configuration, multiple sheets are stacked. It is preferable that the temperature change rate of retardation is optimally set to approximately match the characteristics of the STN liquid crystal cell to be optically compensated.
【００２３】位相差補償シートを複数枚積層して用いる
場合、互に異なる光学特性を有するシートを適度に選択
して用いることが好ましい。積層体は正の１軸性と負の
１軸性を示すポリマーの組合せが特に好ましい。お互い
の遅相軸、または進相軸をほぼ合わせて貼合わせた形態
に於いて、レターデーションの仰角依存性がお互いに逆
の特性になるため、キャンセル効果により、レターデー
ションの仰角依存性の小さい、ＳＴＮ液晶の特性に近い
位相差補償シートが得られ、液晶表示画面を斜めから見
た時の表示性能改善にも効果があるからである。When a plurality of retardation compensation sheets are used in a stacked manner, it is preferable to appropriately select and use sheets having mutually different optical properties. The laminate is particularly preferably a combination of polymers exhibiting positive uniaxiality and negative uniaxiality. In a configuration in which the slow axes or fast axes of each other are bonded together, the elevation angle dependence of retardation becomes opposite to each other, so the elevation angle dependence of retardation is small due to the cancellation effect. This is because a retardation compensating sheet having characteristics close to those of STN liquid crystal can be obtained, and it is also effective in improving display performance when the liquid crystal display screen is viewed from an angle.
【００２４】好ましい積層の具体例は、本発明シート／
ポリカーボネート位相シート、本発明シート／ポリビニ
ルアルコール位相シート等である。本発明の位相差補償
シートは、従来のブルーモード、イエローモードのＳＴ
Ｎ液晶表示を白黒モードにするための光学補償素子とし
て用いられ、レターデーション値は１００〜１０００ｎ
ｍの範囲にあることが好ましい。レターデーションの温
度変化率は、補償するＳＴＮ液晶の温度変化率との差が
、使用温度０〜５０℃に於いて１５％以下であることが
好ましく、更に好ましくは１０％以下であり、広温度環
境化で高品位の表示画面が得られる。[0024] A preferred example of lamination is the sheet of the present invention/
These include a polycarbonate phase sheet, a sheet of the present invention/polyvinyl alcohol phase sheet, and the like. The retardation compensation sheet of the present invention can be used for conventional blue mode and yellow mode ST.
N Used as an optical compensation element to make a liquid crystal display into black and white mode, and has a retardation value of 100 to 1000n.
It is preferably in the range of m. The temperature change rate of the retardation is preferably 15% or less, more preferably 10% or less at the operating temperature of 0 to 50°C, and the difference from the temperature change rate of the STN liquid crystal to be compensated is 15% or less at the operating temperature of 0 to 50°C. A high-quality display screen can be obtained by environmentally friendly technology.
【００２５】ポリ４−メチルペンテン−１あるいは微小
の共重合成分を含む共重合体から成る本発明シートはこ
れまで述べてきた複屈折特性に優れている上に、耐熱性
が高く、透明性に優れ、耐溶剤性にも優れ、非常に好ま
しい位相差補償シートである。従来、一般に知られてい
るポリオレフィンのポリエチレン、ポリプロピレンの位
相差補償シートと本発明位相シートは、１軸延伸シート
では延伸方向の進相軸と遅相軸が逆であり、多軸延伸シ
ートでは厚み方向の屈折率とシート面方向の屈折率の大
小が逆であり、従来のポリオレフィン位相差補償シート
からは全く類推できない。The sheet of the present invention made of poly-4-methylpentene-1 or a copolymer containing a minute copolymer component not only has the excellent birefringence properties described above, but also has high heat resistance and transparency. It is a very preferable retardation compensating sheet as it has excellent solvent resistance. Conventionally, generally known retardation compensating sheets of polyolefins such as polyethylene and polypropylene and the retardation sheet of the present invention have a uniaxially oriented sheet in which the fast and slow axes in the stretching direction are opposite, and a multiaxially oriented sheet in which the thickness The refractive index in this direction and the refractive index in the sheet surface direction are opposite in magnitude, and cannot be inferred from conventional polyolefin retardation compensating sheets at all.
【００２６】[0026]
【実施例】三井石油化学工業（株）製のＴＰＸ樹脂（４
−メチルペンテン−１を主体とした重合体）を押出成形
により原板を成形し、次いで引張り法により約３倍に縦
一軸に引張延伸して本発明のシートを得た。本発明の複
屈折率特性及び各種性質を表１に示した。[Example] TPX resin (4
A sheet of the present invention was obtained by extrusion molding (a polymer mainly composed of methylpentene-1) and then uniaxially stretching it about three times its length by a stretching method. Table 1 shows the birefringence characteristics and various properties of the present invention.
【００２７】[0027]
【表１】[Table 1]
【００２８】該シートのレターデーションの温度変化率
は−２．２５ｎｍ／℃であった。レターデーションの温
度依存性がほとんどないポリビニルアルコールの位相差
補償シートと上記本発明シートを積層して、レターデー
ションの絶対値が５００〜６００ｎｍで、温度変化率が
負である位相差補償シートは、ＳＴＮ液晶の位相差補償
シートとして優れたものであった。The temperature change rate of retardation of the sheet was -2.25 nm/°C. A retardation compensating sheet with an absolute value of retardation of 500 to 600 nm and a negative temperature change rate is obtained by laminating a polyvinyl alcohol retardation compensating sheet whose retardation has almost no temperature dependence and the above-mentioned sheet of the present invention. It was excellent as a retardation compensation sheet for STN liquid crystal.
【００２９】[0029]
【発明の効果】本発明により、液晶表示装置に用いられ
る精密な位相差補償シートとして良好に使用できる。す
なわち、広い温度範囲でコントラスト比の高い良好な液
晶表示ができる。Effects of the Invention According to the present invention, it can be satisfactorily used as a precise retardation compensating sheet used in liquid crystal display devices. That is, a good liquid crystal display with a high contrast ratio can be achieved over a wide temperature range.
【図１】本発明の異方性配向シートの主配向方向を求め
る方法を示したものである。FIG. 1 shows a method for determining the main orientation direction of an anisotropically oriented sheet according to the present invention.
【図２】延伸倍率のＤ及びｄの平均値Ｄ（ａｖ）、ｄ（
ａｖ）を求める方法を示したものである。図１、図２い
ずれも（ａ）は本発明の延伸シート試験片、（ｂ）は加
熱収縮後の試験片である。FIG. 2: Average values D(av), d(
av) is shown. In both FIGS. 1 and 2, (a) is a stretched sheet test piece of the present invention, and (b) is a test piece after heat shrinkage.
Claims (1)
重合体を延伸配向せしめた位相差補償シート。1. A retardation compensating sheet comprising a stretched and oriented polymer mainly composed of 4-methylpentene-1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4955191A JPH04284402A (en) | 1991-03-14 | 1991-03-14 | Novel phase difference compensation sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4955191A JPH04284402A (en) | 1991-03-14 | 1991-03-14 | Novel phase difference compensation sheet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04284402A true JPH04284402A (en) | 1992-10-09 |
Family
ID=12834332
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4955191A Withdrawn JPH04284402A (en) | 1991-03-14 | 1991-03-14 | Novel phase difference compensation sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04284402A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006276672A (en) * | 2005-03-30 | 2006-10-12 | Sumitomo Chemical Co Ltd | Retardation film |
| WO2007129464A1 (en) | 2006-05-01 | 2007-11-15 | Mitsui Chemicals, Inc. | Method of compensating wavelength dependence of birefringence of optical part, optical part, and display obtained with these |
| WO2008139696A1 (en) * | 2007-04-27 | 2008-11-20 | Mitsui Chemicals, Inc. | Film, method for producing the same, and use of the same |
| JP2010113250A (en) * | 2008-11-07 | 2010-05-20 | Mitsui Chemicals Inc | Laminated optical film |
| US8633290B2 (en) | 2008-07-15 | 2014-01-21 | Mitsui Chemicals, Inc. | Optical resin, optical resin composition, optical film, and film |
| JP2016053712A (en) * | 2014-09-02 | 2016-04-14 | 小池 康博 | Optical resin material, manufacturing method for the same, and optical resin member and polarizing plate made of the same |
-
1991
- 1991-03-14 JP JP4955191A patent/JPH04284402A/en not_active Withdrawn
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006276672A (en) * | 2005-03-30 | 2006-10-12 | Sumitomo Chemical Co Ltd | Retardation film |
| WO2007129464A1 (en) | 2006-05-01 | 2007-11-15 | Mitsui Chemicals, Inc. | Method of compensating wavelength dependence of birefringence of optical part, optical part, and display obtained with these |
| JPWO2007129464A1 (en) * | 2006-05-01 | 2009-09-17 | 三井化学株式会社 | Method for correcting wavelength dependency of birefringence of optical component, optical component, and display device obtained using the same |
| WO2008139696A1 (en) * | 2007-04-27 | 2008-11-20 | Mitsui Chemicals, Inc. | Film, method for producing the same, and use of the same |
| JPWO2008139696A1 (en) * | 2007-04-27 | 2010-07-29 | 三井化学株式会社 | Film, production method thereof and use thereof |
| JP4914494B2 (en) * | 2007-04-27 | 2012-04-11 | 三井化学株式会社 | Film, production method thereof and use thereof |
| US8633290B2 (en) | 2008-07-15 | 2014-01-21 | Mitsui Chemicals, Inc. | Optical resin, optical resin composition, optical film, and film |
| JP2010113250A (en) * | 2008-11-07 | 2010-05-20 | Mitsui Chemicals Inc | Laminated optical film |
| JP2016053712A (en) * | 2014-09-02 | 2016-04-14 | 小池 康博 | Optical resin material, manufacturing method for the same, and optical resin member and polarizing plate made of the same |
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