JPH05241021A - Production of phase difference film - Google Patents
Production of phase difference filmInfo
- Publication number
- JPH05241021A JPH05241021A JP4107092A JP4107092A JPH05241021A JP H05241021 A JPH05241021 A JP H05241021A JP 4107092 A JP4107092 A JP 4107092A JP 4107092 A JP4107092 A JP 4107092A JP H05241021 A JPH05241021 A JP H05241021A
- Authority
- JP
- Japan
- Prior art keywords
- film
- stretching
- retardation
- refractive index
- polysulfone
- 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
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、ポリサルフォン系フィ
ルムを横一軸延伸して位相差フィルムを製造する方法に
係り、特に、レターデーシヨンが全面で均一でかつ視野
角特性に優れた位相差フィルムが求められる製造方法の
改良に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a retardation film by laterally uniaxially stretching a polysulfone film, and in particular, a retardation film having a uniform letter distribution on the entire surface and excellent viewing angle characteristics. The present invention relates to the improvement of the manufacturing method required.
【０００２】[0002]
【従来の技術】位相差フィルムとは、一軸延伸された高
分子フィルムの複屈折性（延伸に伴う分子配向により延
伸方向とそれに直交する方向の屈折率が異なるため生ず
る）を利用し、例えば、液晶表示装置の液晶によってそ
の偏光間に生じた位相差を解消させる（位相差補償とい
う）ものである。そして、上記位相差補償性能はレタデ
ーション値Ｒｅ、すなわち延伸方向の屈折率とこれに直
交する方向の屈折率の差Δｎとフィルムの厚みｄとの積
で表される。2. Description of the Related Art A retardation film utilizes the birefringence of a uniaxially stretched polymer film (because the refractive index in the stretching direction differs from that in the direction orthogonal to it depending on the molecular orientation accompanying stretching). The liquid crystal of the liquid crystal display device eliminates the phase difference generated between the polarized lights (referred to as phase difference compensation). The retardation compensation performance is represented by the retardation value Re, that is, the product of the film thickness d and the difference Δn between the refractive index in the stretching direction and the refractive index in the direction orthogonal thereto.
【０００３】このような位相差フィルムは、例えば特開
平２−４２４０６号公報に記載されており、ネックイン
率（延伸方向に直交する方向の収縮率）が１０％以下と
なるように一軸延伸して製造される。Such a retardation film is described in, for example, JP-A-2-42406, and is uniaxially stretched so that the neck-in rate (shrinkage rate in the direction orthogonal to the stretching direction) is 10% or less. Manufactured.
【０００４】しかしながら、こうして製造された位相差
フィルムのレターデーション値Ｒｅは入射光の入射角が
増大すると変化するため、液晶表示装置の表示画面に色
ムラを生じたり、表示画面を正面から見た場合と横方向
から見た場合とによって白黒が反転したいわゆる色反転
現象が生じたりする。However, the retardation value Re of the retardation film manufactured in this way changes as the incident angle of incident light increases, so that color unevenness occurs on the display screen of the liquid crystal display device or the display screen is viewed from the front. A so-called color inversion phenomenon occurs in which black and white are inverted depending on the case and the case of viewing from the lateral direction.
【０００５】他方、特開平２−１９１９０４号公報に
は、『縦一軸延伸法』によって位相差フィルムを製造す
る際、延伸方向と直交する方向の長さをその延伸前の長
さの比の１／ａ1/2 〜１／ａ1/3 に制御することにより
その視野角特性が改善されることが記載されている。On the other hand, in Japanese Unexamined Patent Publication No. 2-191904, when a retardation film is manufactured by the "longitudinal uniaxial stretching method", the length in the direction orthogonal to the stretching direction is defined as 1 of the length ratio before stretching. It is described that the viewing angle characteristics are improved by controlling / a 1/2 to 1 / a 1/3 .
【０００６】[0006]
【発明が解決しようとする課題】ところで、高分子フィ
ルムを延伸処理して位相差フィルムを製造する場合、い
くつかの重要品質の内で以下の３点に特に注意する必要
がある。When a polymer film is stretched to produce a retardation film, it is necessary to pay particular attention to the following three points among some important qualities.
【０００７】(1)上記レターデーションがフィルム全面
で同じであること。(1) The retardation is the same on the entire surface of the film.
【０００８】(2)視野角特性が良好なこと。(2) Good viewing angle characteristics.
【０００９】(3)外観不良がないこと。(3) There is no appearance defect.
【００１０】一方、高分子フィルムを用いて位相差フィ
ルムを製造する方法としては、フィルムを挟み込んだロ
ール間の回転速度の違いを利用してフィルム長手方向に
延伸を行う『縦一軸延伸法』と、機械的にフィルム横方
向に延伸する『横一軸延伸法』の２種類が知られてい
る。そして上記ポリサルフォン系フィルムを延伸する場
合、『縦一軸延伸法』ではフィルムがロールに巻き付い
たり、ロールとフィルムが擦れて傷がついたりするため
上記(3) の品質を満たすことができない。On the other hand, as a method for producing a retardation film using a polymer film, there is a "longitudinal uniaxial stretching method" in which stretching is performed in the longitudinal direction of the film by utilizing the difference in rotation speed between rolls sandwiching the film. Two types of "horizontal uniaxial stretching method" for mechanically stretching the film in the transverse direction are known. When the polysulfone-based film is stretched, the "longitudinal uniaxial stretching method" may not satisfy the quality of (3) because the film may be wound around a roll or the roll and the film may be rubbed and scratched.
【００１１】そこで、外観不良が無いようにポリサルフ
ォン系フィルムの延伸処理法としては『横一軸延伸法』
が通常適用されている。また。(1) のレターデーション
に関しては延伸条件等の最適化により均一にすることが
可能である。Therefore, as a stretching treatment method for a polysulfone-based film so that there is no appearance defect, a "transverse uniaxial stretching method" is used.
Is usually applied. Also. The retardation (1) can be made uniform by optimizing the stretching conditions and the like.
【００１２】しかしながら、上記(2) の視野角特性に関
しては延伸条件で改善することができない。ここで、
『視野角特性が良好』とは、フィルム法線方向からみた
特性と斜め方向からみた特性の差が無い状態を差してい
るが、この視野角特性は樹脂内の屈折率異方性と密接な
関係がある。ここで、『屈折率異方性』とは、フィルム
の延伸方向、これと直交する方向（延伸直角方向）、フ
ィルムの厚み方向の３方向の屈折率がそれぞれ異なって
いる状態を指している。However, the viewing angle characteristic (2) above cannot be improved by stretching conditions. here,
"Good viewing angle characteristics" means that there is no difference between the characteristics when viewed from the film normal direction and the characteristics when viewed from an oblique direction, but this viewing angle characteristics is closely related to the refractive index anisotropy in the resin. I have a relationship. Here, "refractive index anisotropy" refers to a state in which the refractive index is different in the three directions of the stretching direction of the film, the direction orthogonal to this (the direction perpendicular to the stretching), and the thickness direction of the film.
【００１３】そして、上記視野角特性を良好にするため
には、３方向の屈折率の内、延伸直角方向と厚み方向の
屈折率を等しくする方法が容易である。これは以下の理
由による。すなわち、面内（フィルム法線方向からみた
特性）のレターデーションは、延伸方向と延伸直角方向
の屈折率差から求められる。斜め方向からみる場合、こ
れに厚み方向の成分が加わる。この厚み方向の屈折率が
他の２方向に較べて著しく異なる場合、上記レターデー
ションは面内に較べ著しく大きくなるか小さくなる。こ
の斜め方向からみた場合のレターデーションの変化が視
野角の不良である。例えば、この様な位相差フィルムを
液晶ディスプレーに実装した場合、正面と斜めとで色が
反転する現象が起こってしまう。そこで、この斜め方向
からみたレターデーションの変化を極力抑えるために
は、見掛上厚み方向の屈折率が影響しないように延伸直
角方向と厚み方向の屈折率を等しくする方法がよい。In order to improve the viewing angle characteristics, it is easy to make the refractive indices in the three directions perpendicular to the stretching direction equal to those in the thickness direction. This is for the following reason. That is, the in-plane retardation (characteristic viewed from the normal direction of the film) is obtained from the difference in refractive index between the stretching direction and the direction perpendicular to the stretching. When viewed from an oblique direction, a component in the thickness direction is added to this. When the refractive index in the thickness direction is significantly different from those in the other two directions, the retardation is significantly larger or smaller than that in the plane. The change in retardation when viewed from this oblique direction is a poor viewing angle. For example, when such a retardation film is mounted on a liquid crystal display, a phenomenon occurs in which colors are inverted between the front and the diagonal. Therefore, in order to suppress the change in retardation as viewed from the oblique direction as much as possible, it is preferable to make the refractive index in the direction perpendicular to the stretching direction equal to the refractive index in the thickness direction so that the apparent refractive index in the thickness direction does not affect.
【００１４】ところで、この屈折率は樹脂の内部応力に
一次的に比例している。ポリサルフォンフィルムはもと
もと１．６３３の固有屈折率を有しているが、この樹脂
を内から外に引っ張ると屈折率は大きくなり、外から内
に圧縮すると小さくなる。By the way, this refractive index is linearly proportional to the internal stress of the resin. The polysulfone film originally has an intrinsic refractive index of 1.633, but when this resin is pulled from the inside to the outside, the refractive index increases, and when compressed from the outside to the inside, the refractive index decreases.
【００１５】屈折率の変化を延伸に当てはめて考える
と、図３（Ａ）に示すように等方的だった屈折率が延伸
方向へ引っ張られるため大きくなる。他方、厚み方向に
は図３（Ｂ）に示すように圧縮されるため小さくなる。When the change in the refractive index is applied to stretching, the isotropic refractive index becomes large because it is pulled in the stretching direction as shown in FIG. 3 (A). On the other hand, it becomes smaller in the thickness direction because it is compressed as shown in FIG.
【００１６】これに対し『横一軸延伸法』においては延
伸方向と直交する方向（延伸直角方向）には力が作用し
難いため（フィルムを搬送させるためのロール間隔が一
定で規制されているため）、延伸直角方向の変化は少な
い（実際には圧縮力が残留するため僅かながら小さくな
る）。On the other hand, in the "transverse uniaxial stretching method", it is difficult for force to act in the direction orthogonal to the stretching direction (direction orthogonal to the stretching) (because the roll interval for conveying the film is regulated to be constant). ), The change in the direction perpendicular to the stretching is small (actually, the compressive force remains so that it is slightly small).
【００１７】また、延伸処理の際のフィルムの単位体積
を考えると、図４（Ａ）に示すように延伸方向（この場
合ｘ軸方向）にａ倍に引っ張ると、他の２方向（ｙ方向
とｚ軸方向）は普通１／ａ1/2 倍になる（すなわち延伸
前後のフィルムの体積は一定であるからである）。この
場合、屈折率は延伸直角方向と厚み方向共に同じ応力が
かかるため、図４（Ｂ）に示すように上記延伸直角方向
の屈折率（ｎy ）と厚み方向の屈折率（ｎz ）は等しく
なる。Considering the unit volume of the film during the stretching treatment, when the film is pulled a times in the stretching direction (in this case, the x-axis direction) as shown in FIG. And z-axis direction) is usually 1 / a 1/2 times (that is, the volume of the film before and after stretching is constant). In this case, since the same stress is applied to the refractive index both in the direction perpendicular to the stretching direction and in the thickness direction, the refractive index ( ny ) in the direction perpendicular to the stretching and the refractive index ( nz ) in the thickness direction are as shown in FIG. 4B. Will be equal.
【００１８】この状態では視野角特性は良好である。In this state, the viewing angle characteristic is good.
【００１９】ところが、『横一軸延伸法』においては上
述したようにフィルムの長手方向が規制されているため
図５（Ａ）に示すように長手方向（ｙ軸方向）へは収縮
しない。このため、厚み方向は１／ａ倍に収縮し、図５
（Ｂ）に示すように延伸直角方向の屈折率（ｎy ）と厚
み方向の屈折率（ｎz ）が異なってしまい、その視野角
特性が低下する問題点があった。However, in the "transverse uniaxial stretching method", since the longitudinal direction of the film is regulated as described above, the film does not shrink in the longitudinal direction (y-axis direction) as shown in FIG. 5 (A). Therefore, the thickness direction contracts 1 / a times, and
As shown in (B), the refractive index ( ny ) in the direction perpendicular to the stretching is different from the refractive index ( nz ) in the thickness direction, and there is a problem that the viewing angle characteristics are deteriorated.
【００２０】本発明はこのような問題点に着目してなさ
れたものであって、その課題とするところは、ポリサル
フォン系フィルムを用いる横一軸延伸法においてレター
デーションが全面で均一でかつ視野角特性に優れた位相
差フィルムの製造方法を提供するすることにある。The present invention has been made by paying attention to such a problem, and the problem is that the retardation is uniform over the entire surface and the viewing angle characteristics in the transverse uniaxial stretching method using a polysulfone-based film. Another object of the present invention is to provide a method for producing a retardation film having excellent properties.
【００２１】[0021]
【課題を解決するための手段】すなわち、請求項１に係
る発明は、ポリサルフォン系フィルムを横一軸延伸して
位相差フィルムを製造する方法を前提とし、予め横一軸
延伸処理したポリサルフォン系フィルムをその延伸され
た幅方向の長さが固定された状態で移送方向に弛みを設
けながら移送し、かつ、同時に加熱処理して上記ポリサ
ルフォン系フィルムをその延伸方向と直交する方向（延
伸直角方向）へ熱収縮させることを特徴とするものであ
り、また、請求項２に係る発明は請求項１に係る位相差
フィルムの製造方法を前提とし、上記横一軸延伸倍率を
ａとしたとき、上記移送方向の弛み量が、加熱処理前の
長さの（１−１／ａ1/2 ）倍より短く設定されているこ
とを特徴とするものである。That is, the invention according to claim 1 is premised on a method for producing a retardation film by laterally uniaxially stretching a polysulfone-based film, and a polysulfone-based film preliminarily subjected to a laterally uniaxially stretched treatment is provided. The polysulfone-based film is transferred in a direction in which the length in the stretched width direction is fixed while providing slack in the transfer direction, and at the same time, the polysulfone-based film is heated in a direction orthogonal to the stretching direction (direction perpendicular to the stretching). The invention according to claim 2 is premised on the method for producing a retardation film according to claim 1, and the transverse uniaxial stretching ratio is a The slack amount is set to be shorter than (1-1 / a 1/2 ) times the length before the heat treatment.
【００２２】これ等請求項１〜２に係る発明により横一
軸延伸法を適用した場合においてもフィルムの延伸直角
方向への収縮処理が図れるため、延伸直角方向と厚み方
向の屈折率を揃えることが可能となる。すなわち、加熱
処理によってフィルムの延伸直角方向が上記弛み量の分
だけ熱収縮する。こうして得られたフィルムの延伸直角
方向の長さは、熱収縮される前の延伸直角方向の長さの
１／ａ1/2 倍より大きくなり、延伸直角方向の屈折率が
厚み方向の屈折率に近づいて入射角の相違によるレター
デーションＲｅの相違を小さいものとする。Even when the transverse uniaxial stretching method is applied by the invention according to claims 1 and 2, the film can be contracted in the direction perpendicular to the stretching direction, so that the refractive index in the direction perpendicular to the stretching direction and the refractive index in the thickness direction can be made uniform. It will be possible. That is, the heat treatment shrinks the film in the direction perpendicular to the stretching direction by the amount of the slack. The length of the thus obtained film in the direction perpendicular to the stretching is greater than 1 / a 1/2 times the length in the direction perpendicular to the stretching before being heat-shrinked, and the refractive index in the direction perpendicular to the stretching is the refractive index in the thickness direction. The difference in the retardation Re due to the difference in the incident angle is reduced to be smaller than.
【００２３】尚、『移送方向の弛み量』とは、上記延伸
直角方向の収縮前の長さから収縮後の長さを引いた長さ
をいう。The "amount of slack in the transport direction" means the length obtained by subtracting the length after contraction from the length before contraction in the direction perpendicular to the stretching direction.
【００２４】ここで、延伸直角方向の熱収縮の限界は、
延伸前の長さの１／ａ1/2 倍となる長さである。この長
さに収縮させようとすると、実際には高分子鎖のすべり
によって収縮の均一性が保たれずに皺が生じ、外観とレ
ターデーション値Ｒｅの均一性が損なわれるのに対し、
延伸前の長さの１／ａ1/2 倍より大きい場合には皺のな
い均一なレターデーション値Ｒｅを有する位相差フィル
ムを得ることが可能となる。Here, the limit of heat shrinkage in the direction perpendicular to the stretching is
The length is 1 / a 1/2 times the length before stretching. When trying to shrink to this length, in reality, the slippage of the polymer chain does not maintain the uniformity of shrinkage and causes wrinkles, which impairs the appearance and the uniformity of the retardation value Re.
When it is larger than 1 / a 1/2 times the length before stretching, a retardation film having a uniform retardation value Re without wrinkles can be obtained.
【００２５】ところで、一般に延伸されたフィルムを構
成するポリマー鎖は隣接するポリマー鎖と絡み合い、こ
の絡み合いによって生じる剪断力により配向状態を保持
する。そして、一旦延伸されたフィルムにおいては、ガ
ラス転移点以下の温度に加熱された場合であってもこの
剪断力により上記延伸状態が保持される。By the way, generally, the polymer chains constituting the stretched film are entangled with the adjacent polymer chains, and the shearing force generated by the entanglement maintains the oriented state. Then, in the once stretched film, the stretched state is maintained by the shearing force even when the film is heated to a temperature below the glass transition point.
【００２６】ところが、ポリマーの種類によっては上記
剪断力が低いため延伸状態を保持できないものもある。
この樹脂間の滑りを便宜的に『ズリ』と呼んでいるが、
ポリサルフォン系樹脂のズリ量は他の光学用樹脂に較べ
て大きい。However, depending on the type of polymer, the shearing force is low, so that the stretched state cannot be maintained.
The slip between the resins is called "zuri" for convenience.
The amount of misalignment of polysulfone resin is larger than that of other optical resins.
【００２７】前述した横一軸延伸後の収縮状態において
は延伸直角方向が１のまま厚み方向が１／ａ倍であり
（図５Ａ参照）、単純な弾性回復であればそれぞれ１／
ａ1/2になって安定するが、上記『ズリ』のため実際の
回復後は１／ａ1/2 より大きい。この応力緩和も加味し
た回復制御を行うことがポリサルフォン系フィルムの屈
折率制御上重要なポイントである。In the contracted state after the lateral uniaxial stretching described above, the direction perpendicular to the stretching direction is 1 and the thickness direction is 1 / a times (see FIG. 5A).
It becomes a 1/2 and stabilizes, but it is larger than 1 / a 1/2 after the actual recovery due to the above-mentioned “slip”. It is an important point for controlling the refractive index of the polysulfone-based film to perform the recovery control in consideration of the stress relaxation.
【００２８】この１／ａ1/2 より大きな予想回復量は、
１／ａ’1/2 とおくことができる。すなわちａ倍に延伸
したフィルムを、上記『ズリ』分を相殺して見掛上ａ’
倍（ａ’＜ａ）に延伸したフィルムとみなして扱うので
ある。The expected recovery amount larger than 1 / a 1/2 is
It can be set as 1 / a ' 1/2 . In other words, a film stretched a times is apparently a ′ by canceling out the above “slip”.
The film is treated as if it were a film stretched twice (a '<a).
【００２９】そして、延伸直角方向及び厚み方向を１／
ａ’1/2 に制御することで良好な視野角を得ることがで
きる。Then, the direction perpendicular to the stretching and the thickness direction are 1 /
A good viewing angle can be obtained by controlling to a'1 / 2 .
【００３０】このａ’（ａ’：ズリを考慮した理論延伸
倍率）は実測から求めることができる。This a '(a': theoretical stretching ratio in consideration of deviation) can be obtained from actual measurement.
【００３１】以下、この点についてより具体的に説明
と、例えば固有屈折率１．６３３のポリサルフォンフィ
ルムを１．５倍に横一軸延伸すると、延伸方向の屈折率
は１．６３５７に増加する。This point will be described in more detail below. For example, when a polysulfone film having an intrinsic refractive index of 1.633 is laterally uniaxially stretched 1.5 times, the refractive index in the stretching direction increases to 1.6357.
【００３２】そして、この延伸方向の長さを固定したま
ま加熱処理すると屈折率は１．６３４７に低下する。Then, when the heat treatment is carried out while the length in the stretching direction is fixed, the refractive index is lowered to 1.6347.
【００３３】ここで、延伸による長さの増加分と、屈折
率の増加分が比例すると仮定すると、横一軸延伸倍率を
ａ、屈折率をｎ、比例定数をｋとして、下記式（２）が
成立する。Assuming that the increase in length due to stretching and the increase in refractive index are proportional to each other, the following formula (2) is obtained, where a is a lateral uniaxial stretching ratio, n is a refractive index, and k is a proportional constant. To establish.
【００３４】 ｎ＝ｋ×（ａ−１）＋１．６３３ （２） 但し、式中の（ａ−１）は、延伸による長さの増加分を
延伸前の長さで割ったものを意味している。N = k × (a-1) +1.633 (2) However, (a-1) in the formula means a value obtained by dividing the increase in length by stretching by the length before stretching. ing.
【００３５】そして、ａ＝１．５の場合、ｎ＝１．６３
５７であることからｋ＝０．００５４であり、上記
（２）は下記式（３）と書き直すことができる。When a = 1.5, n = 1.63
Since it is 57, k = 0.0054, and the above (2) can be rewritten as the following equation (3).
【００３６】 ｎ＝０．００５４（ａ−１）＋１．６３３ （３） そして、加熱処理後のフィルムの屈折率が１．６３４７
であることから、これと同様の屈折率を有する延伸フィ
ルムの延伸倍率（理論延伸倍率）をａ’とすると、下記
式（４）が成立する。N = 0.0054 (a-1) +1.633 (3) Then, the refractive index of the film after the heat treatment is 1.6347.
Therefore, if the stretch ratio (theoretical stretch ratio) of a stretched film having the same refractive index as this is a ′, the following formula (4) is established.
【００３７】 １．６３４７＝０．００５４（ａ’−１）＋１．６３３ （４） これを計算するとａ’＝１．３１５となり、加熱処理後
のフィルムは見掛け上１．５倍に延伸処理されたもので
ありながら、実質的には１．３１５倍に延伸されたフィ
ルムと同様の配向状態を有するに過ぎず、この理論延伸
倍率ａ’で延伸された横一軸延伸ポリサルフォンフィル
ムと等価に取り扱うことができる。1.6347 = 0.0054 (a'-1) +1.633 (4) When this is calculated, a '= 1.315, and the film after the heat treatment is apparently stretched 1.5 times. However, it has substantially the same orientation as a film stretched 1.315 times, and should be treated equivalently to a lateral uniaxially stretched polysulfone film stretched at this theoretical stretching ratio a '. You can
【００３８】このため、延伸直角方向の長さを延伸前の
長さの１／ａ’1/2 に収縮させた場合、この延伸直角方
向の屈折率と厚み方向の屈折率が等しくなり、入射角の
如何を問わずレターデーション値Ｒｅが一定で視野角特
性の優れたものとなる。Therefore, when the length in the direction perpendicular to the stretching is contracted to 1 / a ' 1/2 of the length before the stretching, the refractive index in the direction perpendicular to the stretching becomes equal to the refractive index in the thickness direction, and the incident light is incident. The retardation value Re is constant regardless of the angle, and the viewing angle characteristics are excellent.
【００３９】請求項３に係る発明はこのような技術的理
由に基づいてなされている。The invention according to claim 3 is based on such a technical reason.
【００４０】すなわち、請求項３に係る発明は請求項１
に係る位相差フィルムの製造方法を前提とし、上記加熱
処理後の屈折率によって特定される理論延伸倍率をａ’
としたとき、上記移送方向の弛み量が、加熱処理前の長
さの略（１−１／ａ’1/2 ）倍にすることを特徴とする
ものである。That is, the invention according to claim 3 is claim 1
Based on the method for producing a retardation film according to the above, the theoretical stretching ratio specified by the refractive index after the heat treatment is a ′.
In this case, the amount of slack in the transfer direction is approximately (1-1 / a ' 1/2 ) times the length before the heat treatment.
【００４１】この請求項３に係る発明において、加熱処
理後の屈折率によって特定される理論延伸倍率ａ’と
は、収縮後の延伸方向の屈折率と同一の屈折率を有する
未収縮の横一軸延伸フィルムの延伸率をいい、上述した
予備実験によって収縮前の屈折率ｎと延伸倍率ａ、及
び、収縮後の屈折率ｎ’を測定して、下記式（５）、及
び（６）から算出することができる。すなわち、 ｎ ＝ｋ×（ａ−１）＋ｎ0 （５） ｎ’＝ｋ×（ａ’−１）＋ｎ0 （６） 但し、ｎ0 は延伸前の固有屈折率、ｋは比例定数であ
る。In the invention according to claim 3, the theoretical draw ratio a'specified by the refractive index after the heat treatment means that the unshrinked transverse uniaxial having the same refractive index as the refractive index in the drawing direction after shrinking. The stretch ratio of the stretched film is calculated by measuring the refractive index n before shrinkage and the stretching ratio a, and the refractive index n ′ after shrinkage by the above-mentioned preliminary experiment and calculating from the following formulas (5) and (6). can do. That, n = k × (a- 1) + n 0 (5) n '= k × (a'-1) + n 0 (6) where, n 0 is specific refractive index before stretching, k is a proportionality constant ..
【００４２】上記弛み量は収縮量に等しいから、収縮後
の延伸直角方向の長さは延伸前の長さの１／ａ’1/2 倍
となる長さに等しい。また、この弛み量又は収縮量は延
伸前の長さ又は収縮後の長さに比較して小さいことか
ら、この弛み量を収縮後の長さの（１−１／ａ’1/2 ）
としてもよい。Since the amount of slack is equal to the amount of contraction, the length in the direction perpendicular to the stretching after contraction is equal to the length which is 1 / a ' 1/2 times the length before stretching. Further, since the amount of slackness or the amount of shrinkage is smaller than the length before stretching or the length after shrinking, this amount of slacking is (1-1 / a ' 1/2 ) of the length after shrinking.
May be
【００４３】尚、実験を繰り返してこの理論延伸倍率を
求めた結果によると、一般に、 １／ａ1/2 ＜ １／
ａ1/3 ＜ １／ａ’1/2の関係が成り立つ。Incidentally, according to the result of obtaining the theoretical draw ratio by repeating the experiment, it is generally found that 1 / a 1/2 <1 /
The relationship of a 1/3 <1 / a ' 1/2 is established.
【００４４】ここで、上記弛み量を（１−１／
ａ’1/2 ）より著しく小さく設定した場合（例えば、ほ
とんどネックイン量が０に近い場合）、加熱処理を加え
ても延伸直角方向に収縮しないため屈折率の変化が起き
ない。従って、延伸直角方向の屈折率を厚み方向の屈折
率に近付けることが困難なため、視野角特性の改善は期
待できなくなる。また、不用意にズリを起こさせてしま
うため、フィルム面内の屈折率差が小さくなり所定のレ
ターデーションを得ることが困難となる。Here, the amount of slack is (1-1 /
When it is set to be significantly smaller than (a'1 / 2 ) (for example, when the neck-in amount is almost 0), the refractive index does not change even if heat treatment is applied, because the shrinkage does not shrink in the direction perpendicular to the stretching direction. Therefore, it is difficult to bring the refractive index in the direction perpendicular to the stretching close to the refractive index in the thickness direction, and improvement in viewing angle characteristics cannot be expected. In addition, since it causes careless displacement, the difference in refractive index in the film plane becomes small, and it becomes difficult to obtain a predetermined retardation.
【００４５】また、上述した特開平２−４２４０６号公
報においてはネックイン率を１０％以下、望ましくは０
％に抑えるように記載されているが、ネックインを束縛
して延伸を行うと上述したように延伸方向に対し直交す
る方向が１／ａ’1/2 倍になれないため、延伸直角方向
と厚み方向の屈折率が等しくならない。従って、視野角
特性の向上は期待できない。特に、ａ’＞１．２４のフ
ィルムにおいてはネックイン率が１０％以下では絶対に
延伸直角方向と厚み方向の屈折率は等しくならず、視野
角特性の良い位相差フィルムは得られない。Further, in the above-mentioned Japanese Patent Laid-Open No. 2-42406, the neck-in rate is 10% or less, preferably 0.
However, if the neck-in is constrained and the stretching is performed, the direction orthogonal to the stretching direction cannot be 1 / a ' 1/2 times as described above. Refractive indices in the thickness direction are not equal. Therefore, improvement in viewing angle characteristics cannot be expected. In particular, in the film of a ′> 1.24, when the neck-in ratio is 10% or less, the refractive index in the direction perpendicular to the stretching and the refractive index in the thickness direction are absolutely not equal, and a retardation film with good viewing angle characteristics cannot be obtained.
【００４６】上述したように予め横一軸延伸したポリサ
ルフォン系フィルムについて、その延伸直角方向をその
延伸前の長さの１／ａ1/2 〜１／ａ’1/2 倍となる長さ
に収縮させると、その収縮率が低下するにつれて入射角
の相違によるレターデーションＲｅの差異が小さくなり
色ムラや色反転現象が減少し、特に、１／ａ’1/2 倍の
長さに収縮させた場合には入射角に係わらずレターデー
ションＲｅがほぼ一定で色ムラや色反転現象が生じ難い
位相差フィルムが得られる。As described above, with respect to the polysulfone-based film that has been laterally uniaxially stretched, the direction perpendicular to the stretching is shrunk to a length which is 1 / a 1/2 to 1 / a ' 1/2 times the length before stretching. Then, as the shrinkage rate decreases, the difference in retardation Re due to the difference in the incident angle becomes smaller, and the color unevenness and the color reversal phenomenon decrease. In particular, the shrinkage is reduced to 1 / a ' 1/2 times. In this case, a retardation film is obtained in which the retardation Re is substantially constant regardless of the incident angle and color unevenness and color reversal phenomenon hardly occur.
【００４７】請求項４〜５に係る発明はこのような技術
的背景に基づいてなされている。The inventions according to claims 4 to 5 are made based on such a technical background.
【００４８】すなわち、請求項４に係る発明は請求項２
に係る位相差フィルムの製造方法を前提とし、他方、請
求項５に係る発明は請求項３に係る位相差フィルムの製
造方法を前提とし、製造された位相差フィルムに対しそ
の法線に平行な方向から波長589.8 ｎｍのナトリウムＤ
線を入射した場合のレターデーションをＲｅ0 とし、法
線に対し４０度の方向から入射した場合のレターデーシ
ョンをＲｅ40としたとき、下記式（１）を満たしている
ことを特徴とするものである。That is, the invention according to claim 4 relates to claim 2.
On the other hand, the invention according to claim 5 is based on the method for producing a retardation film according to claim 3, and is parallel to the normal line to the produced retardation film. Direction D from the direction of 589.8 nm sodium D
When the retardation when a ray is incident is Re 0 and the retardation when the ray is incident from a direction of 40 degrees with respect to the normal is Re 40 , the following formula (1) is satisfied. Is.
【００４９】 ０．８０ ≦ Ｒｅ40／Ｒｅ0 ≦ １．２０ （１）0.80 ≤ Re 40 / Re 0 ≤ 1.20 (1)
【００５０】[0050]
【作用】請求項１に係る発明によれば、予め横一軸延伸
処理したポリサルフォン系フィルムをその延伸された幅
方向の長さが固定された状態で移送方向に弛みを設けな
がら移送し、かつ、同時に加熱処理して上記ポリサルフ
ォン系フィルムをその延伸方向と直交する方向へ熱収縮
させているため、延伸直角方向の屈折率と厚み方向の屈
折率を揃えることが可能となる。According to the first aspect of the present invention, the polysulfone-based film which has been subjected to the lateral uniaxial stretching treatment in advance is transported while slack is provided in the transporting direction while the stretched widthwise length is fixed, and Since the polysulfone-based film is heat-treated at the same time to be heat-shrinked in the direction orthogonal to the stretching direction, the refractive index in the direction perpendicular to the stretching and the refractive index in the thickness direction can be made uniform.
【００５１】また、請求項２に係る発明によれば、横一
軸延伸倍率をａとしたとき、移送方向の弛み量が、加熱
処理前の長さの（１−１／ａ1/2 ）倍より短く設定され
ており、他方、請求項３に係る発明によれば、加熱処理
後の屈折率によって特定される理論延伸倍率をａ’とし
たとき、移送方向の弛み量が、加熱処理前の長さの略
（１−１／ａ’1/2 ）倍に設定しているため、良好な外
観を有ししかも延伸直角方向と厚み方向の屈折率が略同
等の位相差フィルムを製造することができる。According to the second aspect of the invention, when the transverse uniaxial stretching ratio is a, the amount of slack in the transport direction is (1-1 / a 1/2 ) times the length before heat treatment. On the other hand, according to the invention of claim 3, when the theoretical stretch ratio specified by the refractive index after the heat treatment is a ′, the amount of slack in the transport direction is the same as that before the heat treatment. Since the length is set to about (1-1 / a ' 1/2 ) times, a retardation film having a good appearance and having substantially the same refractive index in the direction perpendicular to stretching and the thickness direction should be manufactured. You can
【００５２】また、請求項４〜５に係る発明によれば、
製造された位相差フィルムに対しその法線に平行な方向
から波長589.8 ｎｍのナトリウムＤ線を入射した場合の
レターデーションをＲｅ0 とし、法線に対し４０度の方
向から入射した場合のレターデーションをＲｅ40とした
とき、この製造された位相差フィルムが、 ０．８０ ≦ Ｒｅ40／Ｒｅ0 ≦ １．２０ （１） の（１）式を満たしており、延伸直角方向の屈折率と厚
み方向の屈折率が近似して入射角によるレターデーショ
ン値の変化が小さくなるためその視野角特性の向上が図
れる。According to the invention of claims 4 to 5,
Retardation when a sodium D ray having a wavelength of 589.8 nm was incident on the produced retardation film from a direction parallel to the normal, was Re 0, and retardation when incident on the retardation film was 40 ° to the normal. when was the Re 40, a phase difference film which is the manufacture, meets the 0.80 ≦ Re 40 / Re 0 ≦ 1.20 (1) in (1), stretching perpendicular of the refractive index and the thickness Since the refractive indices in the directions are approximate and the change in the retardation value depending on the incident angle is small, the viewing angle characteristics can be improved.
【００５３】[0053]
【実施例】以下、本発明の実施例について図面を参照し
て詳細に説明する。Embodiments of the present invention will now be described in detail with reference to the drawings.
【００５４】［実施例１］まず、延伸倍率ａ＝１．５倍
で横一軸延伸されたポリサルフォンフィルムの延伸方向
両端を固定した状態で加熱処理してその屈折率を測定
し、上記式（５）、（６）から理論延伸倍率ａ’を求め
た。この結果、ａ’＝１．２４であった。Example 1 First, the polysulfone film laterally uniaxially stretched at a stretching ratio a = 1.5 was heat-treated while fixing both ends in the stretching direction, and the refractive index thereof was measured. ) And (6), the theoretical draw ratio a'was calculated. As a result, a '= 1.24.
【００５５】次に、図１（Ａ）に示すように移送方向に
互いに３００ｍｍの間隔をおいて連結されかつこの間隔
を保ちながら移送方向へライン速度０．５ｍ／ｍｉｎで
移動する一群のクリップ２１、２２、２３、…をセット
し、これ等クリップ２１、２２、２３、…により上記横
一軸延伸された長尺のポリサルフォンフィルムの幅方向
両端部を挟み込んで保持させた。この際、幅方向両端部
のクリップ２１、２２、２３、…間隔は固定されてお
り、これによって延伸された幅方向の長さが固定された
状態になっている。Next, as shown in FIG. 1A, a group of clips 21 which are connected to each other at an interval of 300 mm in the transfer direction and move in the transfer direction at a line speed of 0.5 m / min while maintaining this interval. , 22, 23, ... Are set, and the both ends of the widthwise uniaxially stretched long polysulfone film in the width direction are sandwiched and held by the clips 21, 22, 23 ,. At this time, the intervals of the clips 21, 22, 23, ... At both ends in the width direction are fixed, so that the length in the width direction stretched is fixed.
【００５６】次いで、上記クリップ２１、２２、２３、
…のライン速度より速い速度で回転するガイドローラー
を介し上記横一軸延伸ポリサルフォンフィルム１を送り
込み、それぞれのクリップ２１、２２、２３、…間で移
送方向に弛みを設けながらポリサルフォンフィルム１を
移送した。Next, the clips 21, 22, 23,
The laterally uniaxially stretched polysulfone film 1 was fed through a guide roller that rotates at a speed higher than the line speed, and the polysulfone film 1 was transported between the respective clips 21, 22, 23, ... While providing slack in the transport direction.
【００５７】この際、上記ポリサルフォンフィルム１の
弛み量は、事前に求めた理論延伸倍率ａ’より以下の式
（７）に基づいて決定されている。At this time, the amount of slack of the polysulfone film 1 is determined from the theoretical stretching ratio a'determined in advance based on the following equation (7).
【００５８】 （弛み量）＝（隣接クリップ間距離）×（１−１／ａ’1/2 ） （７） そして、このままの状態で箱型に囲まれた加熱装置内に
導入し、ポリサルフォンフィルム１に対しこのガラス転
移点前後の温度の熱風を３０分間吹き付けて隣接クリッ
プ間でフィルム１を収縮させた。(Looseness amount) = (distance between adjacent clips) × (1-1 / a ′ 1/2 ) (7) Then, in this state, the polysulfone film is introduced into a heating device surrounded by a box shape. The hot air having a temperature around the glass transition point was blown to 1 for 30 minutes to shrink the film 1 between the adjacent clips.
【００５９】加熱処理時のポリサルフォンフィルム１の
状態を図１（Ｂ）に、また、加熱処理後のフィルム１の
状態を図１（Ｃ）に示す。この図１（Ｃ）から分かるよ
うに、ポリサルフォンフィルム１はその移送方向の長さ
が隣接クリップ間隔に等しい長さまで収縮している。The state of the polysulfone film 1 during the heat treatment is shown in FIG. 1 (B), and the state of the film 1 after the heat treatment is shown in FIG. 1 (C). As can be seen from FIG. 1 (C), the polysulfone film 1 has shrunk to a length in the transport direction which is equal to the distance between adjacent clips.
【００６０】尚、上記クリップ２１、２２、２３、…と
しては、図２に示すように幅５mmの平坦部２ａと、斜め
上方からこの平坦部２ａに圧接するへら状の摺動部２ｂ
とでその主要部を構成するものが適用されている。As for the clips 21, 22, 23, ..., As shown in FIG. 2, a flat portion 2a having a width of 5 mm and a spatula-shaped sliding portion 2b which comes into pressure contact with the flat portion 2a from obliquely above.
And what constitutes the main part is applied.
【００６１】そして、加熱処理前後におけるポリサルフ
ォンフィルム１の厚み、幅、レターデーション値、及
び、視野角特性を表１に示す。Table 1 shows the thickness, width, retardation value, and viewing angle characteristics of the polysulfone film 1 before and after the heat treatment.
【００６２】尚、レターデーション値は波長５５５ｎｍ
の入射光を用いて測定し、また、視野角特性はポリサル
フォンフィルム１の法線方向から波長５８９．８ｎｍの
ナトリウムＤ線を入射したときのレターデーションをＲ
ｅ0 、ポリサルフォンフィルム１の法線方向に対し４０
度の入射角で入射したとのレターデーションをＲｅ40と
して式（Ｒｅ0 −Ｒｅ40）／Ｒｅ0 で算出したものであ
る。The retardation value is a wavelength of 555 nm.
And the viewing angle characteristic is the retardation when the sodium D line having a wavelength of 589.8 nm is incident from the normal direction of the polysulfone film 1.
e 0 , 40 with respect to the normal direction of the polysulfone film 1
It is calculated by the formula (Re 0 −Re 40 ) / Re 0, where Re 40 is the retardation when incident at an incident angle of 10 degrees.
【００６３】［実施例２］延伸直角方向における収縮後
の長さが収縮前の長さの１／ａ1/2 〜１／ａ1/3倍間に
設定されている他は実施例１と同様に加熱処理した。[Example 2] The same as Example 1 except that the length after contraction in the direction perpendicular to the stretching was set to be 1 / a 1/2 to 1 / a 1/3 times the length before contraction. The same heat treatment was performed.
【００６４】得られたフィルムの厚み、幅、レターデー
ション値、及び、視野角特性を表１に示す。Table 1 shows the thickness, width, retardation value, and viewing angle characteristics of the obtained film.
【００６５】［比較例１］ポリサルフォンフィルムに弛
みを設けずに処理した以外は実施例１と同様に加熱処理
した。Comparative Example 1 The same heat treatment as in Example 1 was carried out except that the polysulfone film was treated without slack.
【００６６】得られたフィルムの厚み、幅、レターデー
ション値、及び、視野角特性を表１に示す。Table 1 shows the thickness, width, retardation value and viewing angle characteristics of the obtained film.
【００６７】［比較例２］延伸直角方向における収縮後
の長さが収縮前の長さの１／ａ1/2 倍に設定した他は実
施例１と同様に加熱処理した。Comparative Example 2 Heat treatment was carried out in the same manner as in Example 1 except that the length after shrinkage in the direction perpendicular to the stretching was set to 1 / a 1/2 times the length before shrinkage.
【００６８】そして、得られたフィルムを観測したとこ
ろ、フィルム全面に皺が生じて不均一なものであり、厚
み、幅、レターデーション値、及び、視野角特性の測定
は不可能であった。When the obtained film was observed, it was found that wrinkles were formed on the entire surface of the film and it was non-uniform, and it was impossible to measure the thickness, width, retardation value and viewing angle characteristics.
【００６９】[0069]
【表１】 [Table 1]
【００７０】[0070]
【発明の効果】請求項１に係る発明によれば、横一軸延
伸したポリサルフォン系フィルムについてその延伸方向
と直交する方向の屈折率と厚み方向の屈折率とを揃える
ことが可能となる。According to the invention of claim 1, it becomes possible to make the refractive index in the direction orthogonal to the stretching direction and the refractive index in the thickness direction of the polysulfone film laterally uniaxially stretched uniform.
【００７１】また、請求項２〜５に係る発明によれば、
良好な外観を有ししかも延伸直角方向と厚み方向の屈折
率が略同等の位相差フィルムを製造することが可能とな
る。According to the invention of claims 2 to 5,
It is possible to manufacture a retardation film having a good appearance and having substantially the same refractive index in the direction perpendicular to stretching and the thickness direction.
【００７２】従って、製造された位相差フィルムにおけ
る入射角によるレターデーション値の変化が小さいため
その視野角特性を向上できる効果を有している。Therefore, since the variation of the retardation value depending on the incident angle in the manufactured retardation film is small, there is an effect that the viewing angle characteristic can be improved.
【図１】（Ａ）は実施例に係るポリサルフォンフィルム
の加熱処理前の状態を示す説明図、（Ｂ）は加熱処理時
の状態を示す説明図、（Ｃ）は加熱処理後の状態を示す
説明図。FIG. 1A is an explanatory view showing a state before heat treatment of a polysulfone film according to an example, FIG. 1B is an explanatory view showing a state during heat treatment, and FIG. 1C shows a state after heat treatment. Explanatory drawing.
【図２】実施例において適用したクリップの斜視図。FIG. 2 is a perspective view of a clip applied in the embodiment.
【図３】（Ａ）及び（Ｂ）は延伸処理によるフィルムの
変化を示す説明図。FIGS. 3A and 3B are explanatory views showing changes in a film due to a stretching process.
【図４】（Ａ）はフィルムをｘ軸方向へａ倍に一軸延伸
した際の単位体積当りのｙ軸及びｚ軸方向の変化を示す
説明図、（Ｂ）はこの延伸に伴う各方向の屈折率の変化
を示す説明図。FIG. 4 (A) is an explanatory diagram showing changes in the y-axis and z-axis directions per unit volume when the film is uniaxially stretched a times in the x-axis direction by a times, and FIG. Explanatory drawing which shows the change of a refractive index.
【図５】（Ａ）はフィルムをｘ軸方向へａ倍に横一軸延
伸した際の単位体積当りのｙ軸及びｚ軸方向の変化を示
す説明図、（Ｂ）はこの延伸に伴う各方向の屈折率の変
化を示す説明図。FIG. 5 (A) is an explanatory view showing changes in y-axis and z-axis directions per unit volume when a film is laterally uniaxially stretched a times in the x-axis direction a times, and FIG. 5 (B) is each direction accompanying this stretching. Explanatory diagram showing changes in the refractive index of the.
１ ポリサルフォンフィルム ２１ クリップ ２２ クリップ ２３ クリップ 1 Polysulfone film 21 clips 22 clips 23 clips
Claims (5)
て位相差フィルムを製造する方法において、 予め横一軸延伸処理したポリサルフォン系フィルムをそ
の延伸された幅方向の長さが固定された状態で移送方向
に弛みを設けながら移送し、かつ、同時に加熱処理して
上記ポリサルフォン系フィルムをその延伸方向と直交す
る方向へ熱収縮させることを特徴とする位相差フィルム
の製造方法。1. A method for producing a retardation film by laterally uniaxially stretching a polysulfone-based film, wherein a polysulfone-based film that has been subjected to a laterally uniaxially-stretched treatment in advance is transferred in a state in which the stretched widthwise length is fixed. A method for producing a retardation film, characterized in that the polysulfone-based film is heat-shrinked in a direction orthogonal to the stretching direction by transporting the polysulfone film while providing slack and heat treatment at the same time.
／ａ1/2 ）倍より短く設定されていることを特徴とする
請求項１記載の位相差フィルムの製造方法。2. When the transverse uniaxial stretching ratio is a, the amount of slack in the transport direction is (1-1)
2. The method for producing a retardation film according to claim 1, wherein the retardation film is set to be shorter than / a 1/2 ).
る理論延伸倍率をａ’としたとき、 上記移送方向の弛み量が、加熱処理前の長さの略（１−
１／ａ’1/2 ）倍にすることを特徴とする請求項１記載
の位相差フィルムの製造方法。3. When the theoretical draw ratio specified by the refractive index after the heat treatment is defined as a ', the amount of slack in the transport direction is substantially the same as the length before the heat treatment (1-).
The method for producing a retardation film according to claim 1, wherein the ratio is 1 / a ' 1/2 ) times.
に平行な方向から波長589.8 ｎｍのナトリウムＤ線を入
射した場合のレターデーションをＲｅ0 とし、 法線に対し４０度の方向から入射した場合のレターデー
ションをＲｅ40としたとき、下記式（１）を満たしてい
ることを特徴とする請求項２記載の位相差フィルムの製
造方法。 ０．８０ ≦ Ｒｅ40／Ｒｅ0 ≦ １．２０ （１）4. The retardation when sodium D ray having a wavelength of 589.8 nm is incident on the produced retardation film from a direction parallel to the normal line thereof is Re 0, and the retardation is incident from a direction of 40 degrees to the normal line. When the retardation in this case is Re 40 , the following formula (1) is satisfied, and the method for producing a retardation film according to claim 2. 0.80 ≤ Re 40 / Re 0 ≤ 1.20 (1)
に平行な方向から波長589.8 ｎｍのナトリウムＤ線を入
射した場合のレターデーションをＲｅ0 とし、 法線に対し４０度の方向から入射した場合のレターデー
ションをＲｅ40としたとき、下記式（１）を満たしてい
ることを特徴とする請求項３記載の位相差フィルムの製
造方法。 ０．８０ ≦ Ｒｅ40／Ｒｅ0 ≦ １．２０ （１）5. Retardation when a sodium D ray having a wavelength of 589.8 nm is incident on the produced retardation film from a direction parallel to its normal line is Re 0, and it is incident from a direction of 40 ° to the normal line. When the retardation in this case is Re 40 , the following formula (1) is satisfied, the method for producing a retardation film according to claim 3. 0.80 ≤ Re 40 / Re 0 ≤ 1.20 (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4107092A JPH05241021A (en) | 1992-02-27 | 1992-02-27 | Production of phase difference film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4107092A JPH05241021A (en) | 1992-02-27 | 1992-02-27 | Production of phase difference film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05241021A true JPH05241021A (en) | 1993-09-21 |
Family
ID=12598190
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4107092A Pending JPH05241021A (en) | 1992-02-27 | 1992-02-27 | Production of phase difference film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05241021A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0702260A1 (en) | 1994-09-14 | 1996-03-20 | Nippon Oil Co. Ltd. | Compensator for a liquid crystal display |
| US6916440B2 (en) | 2001-05-31 | 2005-07-12 | 3M Innovative Properties Company | Processes and apparatus for making transversely drawn films with substantially uniaxial character |
| US6936209B2 (en) | 2002-11-27 | 2005-08-30 | 3M Innovative Properties Company | Methods and devices for processing polymer films |
| US6949212B2 (en) | 2002-11-27 | 2005-09-27 | 3M Innovative Properties Company | Methods and devices for stretching polymer films |
| US7153122B2 (en) | 2002-05-28 | 2006-12-26 | 3M Innovative Properties Company | Apparatus for making transversely drawn films with substantially uniaxial character |
| US10350818B2 (en) | 2005-04-08 | 2019-07-16 | 3M Innovative Properties Company | Heat setting optical films |
-
1992
- 1992-02-27 JP JP4107092A patent/JPH05241021A/en active Pending
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0702260A1 (en) | 1994-09-14 | 1996-03-20 | Nippon Oil Co. Ltd. | Compensator for a liquid crystal display |
| EP2394805A2 (en) | 2001-05-31 | 2011-12-14 | 3M Innovative Properties Co. | Processes and apparatus for making transversely drawn films with substantially uniaxial character |
| US7740470B2 (en) | 2001-05-31 | 2010-06-22 | 3M Innovative Properties Company | Processes and apparatus for making transversely drawn films with substantially uniaxial character |
| US6939499B2 (en) | 2001-05-31 | 2005-09-06 | 3M Innovative Properties Company | Processes and apparatus for making transversely drawn films with substantially uniaxial character |
| US10913199B2 (en) | 2001-05-31 | 2021-02-09 | 3M Innovative Properties Company | Processes and apparatus for making transversely drawn films with substantially uniaxial character |
| US7229271B2 (en) | 2001-05-31 | 2007-06-12 | 3M Innovative Properties Company | Apparatus for making transversely drawn films with substantially uniaxial character |
| US9314961B2 (en) | 2001-05-31 | 2016-04-19 | 3M Innovative Properties Company | Processes and apparatus for making transversely drawn films with substantially uniaxial character |
| US6916440B2 (en) | 2001-05-31 | 2005-07-12 | 3M Innovative Properties Company | Processes and apparatus for making transversely drawn films with substantially uniaxial character |
| EP2277682A2 (en) | 2001-05-31 | 2011-01-26 | 3M Innovative Properties Co. | Process and apparatus for making transversely drawn films with substantially uniaxial orientation |
| US7153122B2 (en) | 2002-05-28 | 2006-12-26 | 3M Innovative Properties Company | Apparatus for making transversely drawn films with substantially uniaxial character |
| US7104776B2 (en) | 2002-11-27 | 2006-09-12 | 3M Innovative Properties Company | Methods and devices for stretching polymer films |
| US7316558B2 (en) | 2002-11-27 | 2008-01-08 | 3M Innovative Properties Company | Devices for stretching polymer films |
| US6936209B2 (en) | 2002-11-27 | 2005-08-30 | 3M Innovative Properties Company | Methods and devices for processing polymer films |
| US7153123B2 (en) | 2002-11-27 | 2006-12-26 | 3M Innovative Properties Company | Devices for conveying, stretching, and taking-away polymer films |
| US6949212B2 (en) | 2002-11-27 | 2005-09-27 | 3M Innovative Properties Company | Methods and devices for stretching polymer films |
| US10350818B2 (en) | 2005-04-08 | 2019-07-16 | 3M Innovative Properties Company | Heat setting optical films |
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