JP2008001050A - Laminated polyester film for electronic paper, electronic paper using the same, and manufacturing method of elecronic paper using the same - Google Patents

Laminated polyester film for electronic paper, electronic paper using the same, and manufacturing method of elecronic paper using the same Download PDF

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JP2008001050A
JP2008001050A JP2006174953A JP2006174953A JP2008001050A JP 2008001050 A JP2008001050 A JP 2008001050A JP 2006174953 A JP2006174953 A JP 2006174953A JP 2006174953 A JP2006174953 A JP 2006174953A JP 2008001050 A JP2008001050 A JP 2008001050A
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film
laminated
electronic paper
polyester film
laminated film
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Masayuki Yamagishi
正幸 山岸
Takashi Ueda
隆司 上田
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Toray Industries Inc
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Toray Industries Inc
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Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive laminated polyester film which is used for a surface substrate of an electric paper without using a hard coat, by which characters are held without repelling an aqueous ink when writing the characters by the aqueous ink and which is not damaged when erasing the characters by the aqueous ink by a cloth or fingers, or when superposing with other paper as documents in order to solve the problem in the case of using a hard coat film as a surface base material of the electronic paper. <P>SOLUTION: The laminated polyester film for the electronic paper, being the polyester film used for the electronic paper having a laminated film of thickness of 10 to 380 nm in at least one face of the polyester film and a whole light beam transmitting rate of 90.5% or more is characterized in that wet tension of the surface of the laminated film is 25 to 70 mN/m, and center face average roughness is 1.0 to 12.0 nm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は電子ペーパー用部材に関し、詳しくは、積層膜表面の濡れ性、滑り性、耐擦過性に優れ、その表面にハードコート加工を用いなくても電子ペーパーの表面部材として利用できる積層ポリエステルフィルムに関する。また、ハードコート加工を用いない積層ポリエステルフィルムを利用した電子ペーパーとその製造方法に関する。   The present invention relates to a member for electronic paper, and more specifically, a laminated polyester film that is excellent in wettability, slipperiness, and scratch resistance on the surface of a laminated film and can be used as a surface member of electronic paper without using a hard coat process on the surface. About. Moreover, it is related with the electronic paper using the laminated polyester film which does not use a hard-coat process, and its manufacturing method.

ポリエステルフィルムはその汎用性とコストメリット故様々な用途に用いられるが、中でも透明で接着性を付与する積層膜を有する積層ポリエステルフィルムは、光学フィルムとして特に好適に用いられる。例としては薄型テレビの代表格である、液晶ディスプレイにおけるバックライト拡散板、プリズムシート、プラズマディスプレイにおける反射防止フィルム、電磁波カットフィルム、赤外線吸収フィルムなどの部材フィルムとして好適に用いられ、ガラスなどの代わりに用いることで軽量化できる。その他携帯式端末などで使用されるタッチパネルにも透明な積層ポリエステルフィルムは使用され、透明電極を設置して使用する例も見られる。   The polyester film is used for various applications because of its versatility and cost merit. Among them, a laminated polyester film having a laminated film that is transparent and imparts adhesiveness is particularly preferably used as an optical film. For example, it is used as a member film for backlight diffuser plates, prism sheets, antireflection films for plasma displays, electromagnetic wave cut films, infrared absorption films, etc. It can be reduced in weight by using it. In addition, a transparent laminated polyester film is used for a touch panel used in a portable terminal or the like, and an example in which a transparent electrode is installed is also used.

一方、昨今のディスプレイ技術は薄型テレビや携帯式端末のみでなく、電子ペーパーと呼ばれる紙の代わりをなすものまで生み出している。電子ペーパーの基本構成は代表的な例としては米国イーインク(E Ink)社の電気泳動方式と呼ばれるものが挙げられる。例えば、透明な電極の間に電子インク粒子がサンドイッチされた構造をもち、当該電極に電圧をかけた際に、電極間に存在する、帯電させてある色素のついたインク粒子が電気的に引き寄せられることで、各種表示が可能となる(非特許文献1)。画像信号を送るための透明電極を受容する部材として、紙の様に自由に持ち運べる軽量性と曲げたりできる取り扱い性を求めて、ガラスからフィルムへと変わりつつある。
電子ペーパーの形態としてはブック型とペーパー型があり、ブック型としての利用法として電子書籍、電子辞書、ペーパー型の利用法として電子新聞、掲示板などが提案されている。但し、現時点ではディスプレイの延長線上の使用法しか提案されておらず、紙の代わりとして使用するためには、持ち運びがしやすく、多少の変形が可能で、アダプターに接続すれば自在に電子的に静止画像を表示し、その画像を保持できる機能の他に、紙の様に書き込める機能が必要になる。電子ペーパーの最大の目的は紙の代わりに使用する事で、紙の消費量を抑え、地球規模での資源の浪費をなくすことにある。
On the other hand, recent display technologies have created not only flat-screen TVs and portable terminals, but also substitutes for paper called electronic paper. A typical example of the basic configuration of the electronic paper is an electrophoretic method of E Ink, Inc. of the United States. For example, it has a structure in which electronic ink particles are sandwiched between transparent electrodes, and when a voltage is applied to the electrodes, the ink particles with charged pigment that are present between the electrodes are electrically attracted. By doing so, various displays are possible (Non-Patent Document 1). As a member for receiving a transparent electrode for sending an image signal, it is changing from glass to a film in search of light weight that can be freely carried like paper and easy handling that can be bent.
There are two types of electronic paper: book type and paper type. Electronic books and electronic dictionaries are used as book types, and electronic newspapers and bulletin boards are proposed as paper type usages. However, at the moment, only usage on the extended line of the display has been proposed, and it is easy to carry and can be modified slightly to use it as a substitute for paper. In addition to the function of displaying a still image and holding the image, a function of writing like paper is required. The primary purpose of electronic paper is to use it instead of paper to reduce paper consumption and eliminate waste of resources on a global scale.

電子ペーパーの透明電極を受容する部材フィルムとしては、例えば特許文献1の様にポリエステルフィルム上にハードコートを設置して表面の耐擦傷性を向上させたハードコートフィルムに透明電極を設置して使用する例が報告されている。しかしこの場合には下記の5つの不具合が発生する。1つ目にハードコートを設置することにより製造工程が増えることによりコストがかかる点が挙げられる。紙のように手軽に入手する事は難しくなり、どうしてもハードコート面に直接書き込むことをためらうことになる。2つ目にハードコートにより剛性が増すため、紙のように気軽に曲げたりする事が難しくなる点がある。3つ目にハードコート面に三波長蛍光灯などを近づけると見られる干渉ムラの問題がある。ポリエチレンテレフタレート(以下PETと略すことがある)とハードコートの屈折率に差が生じるため、界面の反射光の干渉により、色ムラが発生するが、完全になくすことは原理的に難しい。4つ目にハードコート膜厚が厚いため、表面粗さを制御する事とハードコートフィルム全体の透明性を両立させることが困難な点が挙げられる。5つ目にハードコートとポリエステルは組成が異なるが、ハードコートとポリエステルフィルムは極めて強固に密着し、かつハードコートはある程度の厚みを有するため、再生回収が難しくなる点がある。   As a member film for receiving a transparent electrode of electronic paper, for example, as disclosed in Patent Document 1, a hard coat is installed on a polyester film and the transparent electrode is installed on a hard coat film having improved surface scratch resistance. Examples have been reported. However, in this case, the following five problems occur. The first point is that a cost increases due to an increase in the number of manufacturing steps by installing a hard coat. It becomes difficult to obtain it as easily as paper, and you will hesitate to write directly on the hard coat surface. Secondly, since the rigidity is increased by the hard coat, it is difficult to bend it easily like paper. Thirdly, there is a problem of uneven interference that can be seen when a three-wavelength fluorescent lamp is brought close to the hard coat surface. Since there is a difference in refractive index between polyethylene terephthalate (hereinafter sometimes abbreviated as PET) and hard coat, color unevenness occurs due to interference of reflected light at the interface, but it is theoretically difficult to eliminate it completely. Fourthly, since the hard coat film thickness is large, it is difficult to control both the surface roughness and the transparency of the entire hard coat film. Fifth, the hard coat and the polyester are different in composition, but the hard coat and the polyester film are very tightly adhered, and the hard coat has a certain thickness, so that it is difficult to regenerate and recover.

また他の公知例では、特許文献2ではポリブチレンテレフタレートを使用する例が報告されているが、こちらもハードコートを設置して電子ペーパーに使用するものである。また特許文献3では、ポリエチレンテレフタレートやポリエチレンナフタレートを使用する例が報告されているが、こちらもハードコートを設置して電子ペーパーに使用するものである。
「図解入門 よくわかる 最新ディスプレイ技術の基本と仕組み」株式会社 秀和システム発行 特開2003−182009号公報 特開2005−162768号公報 特開2004−9362号公報
In another known example, Patent Document 2 reports an example of using polybutylene terephthalate, but this is also used for electronic paper by installing a hard coat. In Patent Document 3, an example of using polyethylene terephthalate or polyethylene naphthalate is reported, but this is also used for electronic paper by installing a hard coat.
“Introduction to illustrations: Basics and mechanism of the latest display technology” JP 2003-182009 A JP 2005-162768 A JP 2004-9362 A

本発明の目的は、ハードコートフィルムを電子ペーパーの表面部材として用いた場合の不具合を解決するため、ハードコートを用いずに電子ペーパーの表面部材に使用できる積層ポリエステルフィルムを提供する事に有り、その結果要求される、電子ペーパーに水性インクで字を書き込んだ時に、はじかずに字を保持できること、及び電子ペーパー上の水性インクの字を布や指で消した時や書類として他の紙と重ね合わせた時にも傷がつかない、安価な積層ポリエステルフィルムを提供する事にある。   An object of the present invention is to provide a laminated polyester film that can be used for a surface member of an electronic paper without using a hard coat in order to solve the problems when the hard coat film is used as a surface member of an electronic paper. As a result, when characters are written on the electronic paper with water-based ink, the characters can be retained without repelling, and when the water-based ink characters on the electronic paper are erased with a cloth or finger or as a document The object is to provide an inexpensive laminated polyester film that is not damaged when laminated.

すなわち、本発明は
(1)電子ペーパー用のポリエステルフィルムであって、該ポリエステルフィルムは少なくとも片面に厚さ10〜350nmの積層膜を有し、該積層膜表面における中心面平均粗さが1.0〜12.0nmであり、全光線透過率が90.5%以上であることを特徴とする電子ペーパー用積層ポリエステルフィルム。
(2)積層膜表面における濡れ張力が25〜70mN/mである(1)に記載の電子ペーパー用積層ポリエステルフィルム。
(3)ヘイズが2.0%以下である(1)または(2)に記載の電子ペーパー用積層ポリエステルフィルム。
(4)積層膜が電子ペーパーの、人が触れる側(A側)の最外層として用いられる(1)〜(3)のいずれかに記載の電子ペーパー用積層ポリエステルフィルム。
(5)ポリエステルフィルムが、ポリエチレンテレフタレートフィルムである(1)〜(4)のいずれかに記載の電子ペーパー用積層ポリエステルフィルム。
(6)150℃で30分加熱後の熱収縮率が長手方向、幅方向いずれも2.0%以下である(1)〜(5)のいずれかに記載の電子ペーパー用積層ポリエステルフィルム。
(7)(1)〜(6)のいずれかに記載の積層ポリエステルフィルムを用いた電子ペーパー。
(8)(1)〜(6)のいずれかに記載の積層ポリエステルフィルムの片面に透明電極を設け、その反対面の積層膜の上にハードコートを設けず電子ペーパーの部材として使用する電子ペーパーの製造方法、である。
That is, the present invention is (1) a polyester film for electronic paper, wherein the polyester film has a laminated film having a thickness of 10 to 350 nm on at least one side, and the center plane average roughness on the laminated film surface is 1. A laminated polyester film for electronic paper, which has a light transmittance of 90.5% or more and a thickness of 0 to 12.0 nm.
(2) The laminated polyester film for electronic paper according to (1), wherein the wetting tension on the surface of the laminated film is 25 to 70 mN / m.
(3) The laminated polyester film for electronic paper according to (1) or (2), wherein the haze is 2.0% or less.
(4) The laminated polyester film for electronic paper according to any one of (1) to (3), wherein the laminated film is used as an outermost layer on the side (A side) touched by electronic paper.
(5) The laminated polyester film for electronic paper according to any one of (1) to (4), wherein the polyester film is a polyethylene terephthalate film.
(6) The laminated polyester film for electronic paper according to any one of (1) to (5), wherein the heat shrinkage ratio after heating at 150 ° C. for 30 minutes is 2.0% or less in both the longitudinal direction and the width direction.
(7) Electronic paper using the laminated polyester film according to any one of (1) to (6).
(8) Electronic paper used as a member of electronic paper without providing a hard coat on the laminated film on the opposite side provided with a transparent electrode on one side of the laminated polyester film according to any one of (1) to (6) Manufacturing method.

本発明によって、ハードコートを使用せずに電子ペーパーの表面部材に用いることができ、電子ペーパーに水性インクで字を書き込んだ時も字をはじかずに保存でき、布や指で水性インクを除去した後や他の書類と重ね合わせて持ち運んだ後も傷が発生しない、積層ポリエステルフィルムを提供する事ができた。   According to the present invention, it can be used as a surface member of electronic paper without using a hard coat, and can be stored without repelling characters when written with water-based ink on electronic paper, and water-based ink can be removed with a cloth or finger. It was possible to provide a laminated polyester film that does not cause scratches even after being carried over with other documents.

本発明における積層ポリエステルフィルムとは、基材ポリエステルフィルムの上に積層膜が片面、もしくは両面に設けられたものである。本発明で電子ペーパーの表層部材として用いる場合は、人が触れる側(A側)には必ず積層膜が設けられていなければならない。電子ペーパーのA側の反対側(B側)については、透明電極が設置できれば特に限定するものではなく、積層膜上に電極を設けてもよいし、基材ポリエステルフィルムの裸面に電極を設けてもよい。またB側の積層膜はA側と違う種類のものであってもかまわない。あらかじめ透明電極を設けておいた薄いフィルムを、B側に粘着剤などで貼り付けてもよい。   The laminated polyester film in the present invention is one in which a laminated film is provided on one side or both sides on a base polyester film. When used as a surface layer member of electronic paper in the present invention, a laminated film must be provided on the side touched by a person (A side). The side opposite to the A side (B side) of the electronic paper is not particularly limited as long as a transparent electrode can be installed. The electrode may be provided on the laminated film, or the electrode is provided on the bare surface of the base polyester film. May be. The laminated film on the B side may be of a different type from the A side. A thin film provided with a transparent electrode in advance may be attached to the B side with an adhesive or the like.

A側の積層膜の厚さは10〜350nmであることが必要であり、好ましくは20〜250nm、さらに好ましくは30〜200nmである。10nm未満の場合は後述で示す易滑粒子の径が大きくできない理由から好ましくない。350nm以上の場合は積層ポリエステルフィルムを巻き取る際にフィルム1枚1枚がくっつくブロッキングと呼ばれる現象が起こる可能性が高く、また後述する易滑粒子の径が大きくなりすぎる理由からも好ましくない。   The thickness of the laminated film on the A side needs to be 10 to 350 nm, preferably 20 to 250 nm, and more preferably 30 to 200 nm. When it is less than 10 nm, it is not preferable because the diameter of the easy-sliding particles described later cannot be increased. When the thickness is 350 nm or more, there is a high possibility that a phenomenon called blocking, in which each film is stuck to each other when the laminated polyester film is wound, and it is not preferable because the diameter of the easy-slip particles described later becomes too large.

A側の積層膜表面の中心面平均粗さは1.0〜12.0nmである必要があり、好ましくは2.0〜10.0nm、さらに好ましくは3.0〜8.0nmである。1.0nm以下である場合は、積層膜表層に書かれた水性ペンの字を布や指で拭き消す際や、書類として他の紙や樹脂シートと重ね合わせて持ち運びする際に、電子ペーパー最表層の積層ポリエステルフィルム自体に傷がつくので好ましくない。また12.0nm以上である場合は積層ポリエステルフィルムのヘイズが上昇する要因となるので好ましくない。中心面平均粗さの達成方法は後述する。   The center plane average roughness of the A-side laminated film surface needs to be 1.0 to 12.0 nm, preferably 2.0 to 10.0 nm, and more preferably 3.0 to 8.0 nm. When the thickness is 1.0 nm or less, when wiping off the water-based pen written on the surface of the laminated film with a cloth or finger, or when carrying it as a document on top of another paper or resin sheet, Since the laminated polyester film itself is scratched, it is not preferable. Moreover, since it becomes a factor which the haze of a laminated polyester film raises when it is 12.0 nm or more, it is unpreferable. A method for achieving the center plane average roughness will be described later.

積層ポリエステルフィルムの全光線透過率は90.5%以上が必要であり、好ましくは91.0%以上、さらに好ましくは91.5%以上である。電子ペーパーで使用する際に表面の部材フィルムが透明性でないと、外光もしくは内蔵光の利用効率が下がり、電子インク粒子などによって印字された画像が見えにくくなる。全光線透過率は積層膜の有無に大きく依存し、積層膜なしよりは片面、片面積層膜よりは両面の方が全光線透過率は増加する。空気層の屈折率1.0とポリエステルフィルム基材部分(ポリエチレンテレフタレートの場合)の屈折率1.65との界面での反射を低く抑えることが必要である。空気層と積層膜、及び積層膜とポリエステル基材部分の屈折率差を低く抑えることを考えると、積層膜の屈折率は1.45〜1.63の範囲が好ましい。またこの屈折率範囲内では、350nm以下であれば、積層膜の厚さは厚い方が全光線透過率を高くできる。   The total light transmittance of the laminated polyester film needs to be 90.5% or more, preferably 91.0% or more, and more preferably 91.5% or more. When the surface member film is not transparent when used in electronic paper, the utilization efficiency of external light or built-in light is reduced, and an image printed with electronic ink particles or the like is difficult to see. The total light transmittance greatly depends on the presence or absence of the laminated film, and the total light transmittance increases on one side than on the laminated film and on both sides than the single-area layer film. It is necessary to suppress reflection at the interface between the refractive index of the air layer of 1.0 and the refractive index of 1.65 of the polyester film base material (in the case of polyethylene terephthalate). Considering to suppress the refractive index difference between the air layer and the laminated film and between the laminated film and the polyester base material, the refractive index of the laminated film is preferably in the range of 1.45 to 1.63. In this refractive index range, if the thickness is 350 nm or less, the total light transmittance can be increased as the thickness of the laminated film increases.

またヘイズは2.0%以下が必要であり、好ましくは1.5%以下、さらに好ましくは1.0%以下である。ヘイズが2.0%以上では、拡散光によって電子ペーパーの画像が白く濁ってしまうからである。ヘイズの達成方法は後述する。   The haze needs to be 2.0% or less, preferably 1.5% or less, and more preferably 1.0% or less. This is because when the haze is 2.0% or more, the image of the electronic paper becomes white and turbid due to the diffused light. A method for achieving haze will be described later.

積層膜表面の中心面平均粗さ、積層膜の厚さ、積層ポリエステルフィルムの全光線透過率とヘイズは、大きく絡み合う因子である。電子ペーパーを含めた光学用途に使用される積層ポリエステルフィルムは、全光線透過率やヘイズから決まる高透明性が要求されるため、基材ポリエステルフィルムには易滑性のための粒子を添加しない方が好ましく、積層膜中に粒子を添加する事が好ましい。さて積層膜に粒子を添加した場合、その粒子径と積層膜の厚さには密接な関係がある。粒子径が積層膜厚さに対して大きすぎた場合は、積層膜が粒子を保持できなくなる。粒子径が積層膜厚さに対して小さすぎた場合は、積層膜の内部に粒子が埋もれてしまうため、易滑性の向上に寄与しなくなる。添加粒子の径は積層膜厚さの1.1倍以上3.0倍未満が好ましい。この制限下では、積層膜の厚みは上述で示した10nm以上350nm以下の範囲内でなければ、添加粒子の径を好ましく選択できない。添加粒子の径は30nm以上385nm以下が好ましく、30nm未満ではA側に要求される積層膜表面の中心線平均粗さを1.0nm以上にする事が困難であり、385nm以上では中心面平均粗さが12.0nm以上となりやすく積層ポリエステルフィルムのヘイズが2.0%以上に増加する可能性がある。この制限下でA側に要求される積層膜表面の中心面平均粗さを上げるために、添加粒子の径を大きくするだけでなく添加量を増やすことも、積層ポリエステルフィルムの全光線透過率とヘイズを損なわない範囲で実施してよい。積層膜に添加する易滑粒子は、無機粒子で、シリカ、コロイダルシリカ、アルミナ、アルミナゾル、カオリン、タルク、マイカ、炭酸カルシウムなどを用いることができる。   The center surface average roughness of the surface of the laminated film, the thickness of the laminated film, the total light transmittance and the haze of the laminated polyester film are factors that are greatly intertwined. Laminated polyester films used for optical applications including electronic paper require high transparency determined by total light transmittance and haze, so the base polyester film does not contain particles for easy slipping. It is preferable to add particles to the laminated film. When particles are added to the laminated film, there is a close relationship between the particle diameter and the thickness of the laminated film. When the particle diameter is too large with respect to the laminated film thickness, the laminated film cannot hold the particles. When the particle diameter is too small with respect to the laminated film thickness, the particles are buried in the laminated film, so that it does not contribute to the improvement of the slipperiness. The diameter of the additive particles is preferably 1.1 times or more and less than 3.0 times the laminated film thickness. Under this limitation, the diameter of the additive particles cannot be preferably selected unless the thickness of the laminated film is within the range of 10 nm to 350 nm as described above. The diameter of the additive particles is preferably 30 nm or more and 385 nm or less, and if it is less than 30 nm, it is difficult to make the center line average roughness of the laminated film surface required on the A side 1.0 nm or more, and if it is 385 nm or more, the center plane average roughness Tends to be 12.0 nm or more, and the haze of the laminated polyester film may increase to 2.0% or more. In order to increase the center plane average roughness of the laminated film surface required on the A side under this restriction, it is possible to increase not only the diameter of the additive particles but also the additive amount, the total light transmittance of the laminated polyester film and You may implement in the range which does not impair haze. The slippery particles added to the laminated film are inorganic particles, and silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, and the like can be used.

A側の積層膜表面の濡れ指数は25〜70mN/mであることが必要であり、好ましくは30〜65mN/m、さらに好ましくは35〜60mN/mである。25mN/m 以下の場合は、水性インクをはじくことにより水性ペンで書いた字が保持できなくなってしまうからである。また70mN/m 以上の場合は、水性インクが濡れすぎて、にじんでしまうため逆に好ましくない。
この濡れ指数を制御するための最も大きな因子は主成分の樹脂の選択である。樹脂を変えることで濡れ指数が変わることは自明であるが、基材ポリエステルフィルムの表面に配される積層膜の主成分としては、水系コーティングが可能であるための水溶もしくは水分散可能な樹脂、かつ基材ポリエステルフィルムと水性インク両方に接着性を有するものが好ましい。また全光線透過率を90.5%以上にするために、屈折率は1.45〜1.63の範囲の樹脂を選択することが好ましい。かかる状況に好ましい樹脂としてはポリエステル樹脂、ポリカーボネート樹脂、エポキシ樹脂、アルキッド樹脂、アクリル樹脂、尿素樹脂、ウレタン樹脂などが好ましく、場合によっては異なる2種の樹脂、例えば、ポリエステル樹脂とウレタン樹脂、ポリエステル樹脂とアクリル樹脂、あるいはウレタン樹脂とアクリル樹脂を組み合わせて用いてもよい。またこの濡れ指数を制御するために、帯電防止剤や界面活性剤などの添加剤を付与することも、積層ポリエステルフィルムの透明性や水性インクとの接着性を妨げない程度であれば好ましい。また積層膜の基材ポリエステルフィルムと水性インク両方の接着性を向上させるために架橋剤を添加してもよく、中でもメラミン系架橋剤やオキサゾリン系架橋剤が上記樹脂との親和性の点で好ましい。
The wetting index on the surface of the laminated film on the A side needs to be 25 to 70 mN / m, preferably 30 to 65 mN / m, more preferably 35 to 60 mN / m. If it is 25 mN / m 2 or less, the characters written with the water-based pen cannot be retained by repelling the water-based ink. On the other hand, when it is 70 mN / m 2 or more, the water-based ink is too wet and bleeds.
The biggest factor for controlling the wetting index is selection of the main component resin. It is obvious that the wetting index changes by changing the resin, but as a main component of the laminated film disposed on the surface of the base polyester film, a water-soluble or water-dispersible resin for enabling water-based coating, And what has adhesiveness to both a base polyester film and water-based ink is preferable. In order to make the total light transmittance 90.5% or more, it is preferable to select a resin having a refractive index in the range of 1.45 to 1.63. Preferred resins for this situation are polyester resins, polycarbonate resins, epoxy resins, alkyd resins, acrylic resins, urea resins, urethane resins, etc., and two different resins depending on the case, for example, polyester resins and urethane resins, polyester resins And acrylic resin, or urethane resin and acrylic resin may be used in combination. In order to control the wetting index, it is preferable to add an additive such as an antistatic agent or a surfactant as long as the transparency of the laminated polyester film and the adhesiveness to the water-based ink are not hindered. A cross-linking agent may be added to improve the adhesion of both the base polyester film of the laminated film and the water-based ink. Among them, melamine-based cross-linking agents and oxazoline-based cross-linking agents are preferable from the viewpoint of affinity with the resin. .

B側の積層膜を設置する場合は、B側の積層膜は濡れ指数、中心面平均粗さについては特に限定するものではなく、積層ポリエステルフィルムの全光線透過率が90.5%以上、ヘイズが2.0%以下であることを妨げなければよい。   When the B-side laminated film is installed, the B-side laminated film is not particularly limited with respect to the wetting index and the center plane average roughness, and the total light transmittance of the laminated polyester film is 90.5% or more, haze Should not be prevented from being 2.0% or less.

次に、積層ポリエステルフィルムの製造方法について述べる。   Next, a method for producing a laminated polyester film will be described.

基材フィルム部分に用いられるポリエステル樹脂はジカルボン酸類とグリコール類を重合して得られる。そこで用いられるジカルボン酸類としては、テレフタル酸、ナフタレンジカルボン酸、イソフタル酸、ジフェニルカルボン酸、ジフェニルスルホンジカルボン酸、ジフェノキシエタンジカルボン酸、5−ナトリウムスルホンジカルボン酸、フタル酸などの芳香族ジカルボン酸や、シュウ酸、コハク酸、アジピン酸、セバシン酸、ダイマー酸、マレイン酸、フマル酸などの脂肪族ジカルボン酸、シクロヘキサンジカルボン酸などの脂環族ジカルボン酸、パラオキシ安息香酸などのオキシカルボン酸などが使用できる。また、ポリエステル樹脂に用いられるグリコール類としては、エチレングリコール、プロパンジオール、ブタンジオール、ペンタンジオール、ヘキサンジオール、ネオペンチルグリコールなどの脂肪族グリコールや、ジエチレングリコール、ポリエチレングリコール、ポリプロピレングリコールなどのポリオキシアルキレングリコール、シクロヘキサンジメタノールなどの脂環族グリコール、ビスフェノールA、ビスフェノールSなどの芳香族グリコールなどが使用できる。また、これらのジカルボン酸類、グリコール類は、それぞれ2種以上を併用してもよい。但し本発明においては、機械的強度、耐候性や耐化学薬品性、透明性などを考慮すると、前者にテレフタル酸もしくはナフタレンジカルボン酸を、後者にエチレングリコールを用いることが好ましいが、紙の代わりの安価な材料と考えるなら、前者にテレフタル酸を用いたポリエチレンテレフタレートを用いることがより好ましい。   The polyester resin used for the base film portion is obtained by polymerizing dicarboxylic acids and glycols. As dicarboxylic acids used there, aromatic dicarboxylic acids such as terephthalic acid, naphthalene dicarboxylic acid, isophthalic acid, diphenyl carboxylic acid, diphenyl sulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, 5-sodium sulfone dicarboxylic acid, phthalic acid, Oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, fumaric acid and other aliphatic dicarboxylic acids, cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids, and paraoxybenzoic acid and other oxycarboxylic acids can be used. . The glycols used in the polyester resin include aliphatic glycols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, and neopentylglycol, and polyoxyalkylene glycols such as diethylene glycol, polyethylene glycol, and polypropylene glycol. In addition, alicyclic glycols such as cyclohexanedimethanol, aromatic glycols such as bisphenol A and bisphenol S can be used. These dicarboxylic acids and glycols may be used in combination of two or more. However, in the present invention, in consideration of mechanical strength, weather resistance, chemical resistance, transparency, etc., it is preferable to use terephthalic acid or naphthalenedicarboxylic acid for the former and ethylene glycol for the latter. If considered as an inexpensive material, it is more preferable to use polyethylene terephthalate using terephthalic acid for the former.

また、フィルムに走行性(易滑性)や耐候性、耐熱性などの機能を持たせるため、フィルム原料に粒子を添加してもよいが、フィルムの高透明性を損なわないように添加量や材質に十分な注意が必要である。上述したように、添加量については好ましくはきわめて少量、さらに好ましくは無添加である。フィルムの走行性(易滑性)に関しては、上述したように、積層膜の添加粒子で補助するのが好ましい。   In addition, in order to give the film functions such as runnability (easiness of sliding), weather resistance, and heat resistance, particles may be added to the film raw material. Careful attention to the material is required. As described above, the addition amount is preferably very small, and more preferably no addition. As described above, the running property (slidability) of the film is preferably assisted by the additive particles of the laminated film.

ポリエステルフィルムとは、ジカルボン酸類とグリコール類を重合して得られるポリエステルを、必要に応じて乾燥し、公知の溶融押出し機に供給し、スリット状のダイから単層または複合層のシート状に押出し、静電印加などの方式によりキャスティングドラムに密着、冷却固化して未延伸シートとした後、延伸、熱処理したフィルムのことである。熱的および機械的安定性の問題から、二軸方向の延伸であることが好ましい。延伸方法としては、長手方向に延伸した後、幅方向に延伸する逐次二軸延伸方法や、長手方向、幅方向をほぼ同時に延伸する同時二軸延伸方法などの公知技術が用いられる。ここで長手方向とはフィルム製造ラインのフィルム走行方向であり、幅方向とはそれと直交する方向のことである。   The polyester film is a polyester obtained by polymerizing dicarboxylic acids and glycols, dried as necessary, supplied to a known melt extruder, and extruded from a slit die to a single layer or composite layer sheet. It is a film that has been stretched and heat-treated after being brought into close contact with the casting drum by a method such as electrostatic application, solidifying by cooling and forming an unstretched sheet. From the viewpoint of thermal and mechanical stability, stretching in the biaxial direction is preferable. As the stretching method, known techniques such as a sequential biaxial stretching method of stretching in the width direction after stretching in the longitudinal direction and a simultaneous biaxial stretching method of stretching the longitudinal direction and the width direction almost simultaneously are used. Here, the longitudinal direction is the film running direction of the film production line, and the width direction is a direction perpendicular to the width direction.

電子ペーパーに使用する積層ポリエステルフィルムとしては、透明電極設置の際の加熱による寸法変化は少ない方が、透明電極を欠陥なく定着させるために有利であり、150℃で30分加熱後の熱収縮率が長手方向、幅方向いずれも2.0%以下であることが必要である。長手方向、幅方向いずれも1.2%以下が好ましく、0.5%以下の場合はさらに好ましい。達成手段としてはポリエチレンテレフタレートフィルムの場合、延伸時のフィルム温度は80℃〜130℃の範囲で高い方が好ましく、製造ラインの中で予備加熱をしておくことが好ましい。延伸倍率は2.5〜4.0倍の範囲で低い方が好ましい。延伸後の熱処理の温度は200〜240℃の範囲で高くすることが好ましく、逐次二軸延伸の場合も長手方向と幅方向の延伸が両方終了してから一度に行う。この熱処理の際には、ステンターの速度や幅を制御してフィルムへの張力をカットする弛緩処理を行うことが好ましい。   As the laminated polyester film used for electronic paper, the smaller the dimensional change due to heating when installing the transparent electrode, the more advantageous is to fix the transparent electrode without defects, and the thermal shrinkage after heating at 150 ° C. for 30 minutes Is required to be 2.0% or less in both the longitudinal direction and the width direction. Both the longitudinal direction and the width direction are preferably 1.2% or less, and more preferably 0.5% or less. As an achievement means, in the case of a polyethylene terephthalate film, the film temperature during stretching is preferably higher in the range of 80 ° C. to 130 ° C., and preheating is preferably performed in the production line. The draw ratio is preferably as low as 2.5 to 4.0 times. The temperature of the heat treatment after stretching is preferably increased in the range of 200 to 240 ° C. In the case of sequential biaxial stretching, it is performed at the same time after both the stretching in the longitudinal direction and the width direction are completed. In this heat treatment, it is preferable to perform a relaxation treatment for controlling the speed and width of the stenter to cut the tension on the film.

本発明の積層ポリエステルフィルムを製造工程の中で、前述の積層膜を設けるのに好ましい方法としては、ポリエステルフィルムの製造工程中に設け、フィルムと共に延伸する方法が好適であり、中でも生産性を考慮すると、上述で紹介するように、製膜工程中に塗布方法で設ける方法が最も好適である。また環境や人体への影響を考慮した場合、溶剤を主とする塗料ではなく、水を主として水分散性の固形分を含んだ水系塗料を用いるのが好ましい。フィルム基材上への塗布の方法は各種の塗布方法、例えば、リバースコート法、グラビアコート法、ロッドコート法、バーコート法、マイヤーバーコート法、ダイコート法、スプレーコート法などを用いることができる。またコーティング膜の塗布の均一性や接着性を考慮して、表面にコロナ放電を施しても構わない。   As a preferable method for providing the above-mentioned laminated film in the production process of the laminated polyester film of the present invention, a method of providing the polyester film during the production process and stretching together with the film is preferable, and productivity is considered in particular. Then, as introduced above, a method of providing a coating method during the film forming process is most suitable. In consideration of the influence on the environment and the human body, it is preferable to use a water-based paint mainly containing water and a water-dispersible solid content instead of a paint mainly containing a solvent. Various coating methods such as a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a Meyer bar coating method, a die coating method, a spray coating method and the like can be used as a method for coating on a film substrate. . Further, in consideration of the uniformity of coating film application and adhesiveness, corona discharge may be applied to the surface.

本発明におけるポリエステル製の基材部分については、フィルムの厚みは、30μm以下であると熱的および機械的安定性に不足が生じ、また、350μm以上であると、剛性が高すぎて取り扱い性が低下すること、ロール長尺化が物理的に困難になること、そして透明性などに問題が生じやすいため、30〜350μmが好ましく、より好ましくは50〜300μmである。   With respect to the polyester substrate portion in the present invention, if the film thickness is 30 μm or less, the thermal and mechanical stability is insufficient, and if it is 350 μm or more, the rigidity is too high and the handleability is high. It is preferably 30 to 350 μm, more preferably 50 to 300 μm, because it is difficult to reduce the length of the roll, and it is difficult to increase the length of the roll.

本発明における評価基準は次の通りである。
(1)積層膜の厚み
積層ポリエステルフィルムの断面を凍結超薄切片法にて切り出し、RuO染色による染色超薄切片法により、日立製作所製透過型電子顕微鏡H−7100FA型を用い、加速電圧100kVにて積層膜部の観察、写真撮影を行った。その断面写真から任意の5箇所の積層膜の厚みを拡大倍率から計算し平均化した。
(2)積層膜表面の中心面平均粗さ
JIS−B−0601に従って、小坂研究所社製 触針式三次元粗さ計「ET4000AK」により、フィルム積層膜上の任意の直線上の形状を80箇所、測定長0.5mmで計測し、Cut Off 0.25mmの演算により中心面平均粗さを求めた。接触する針の曲率は2.0μmRであった。
(3)積層ポリエステルフィルムの全光線透過率とヘイズ
スガ試験機株式会社製全自動直読ヘイズコンピューター「HGM−2DP」を用いて、550nmの波長の光に対して、JIS−K−7105に従って行った。
(4)積層膜表面の濡れ張力
JIS−K−6768に従って、フィルムの積層膜上に綿棒で試験用混合液を6cmの面積に塗布し、2秒後の塗膜の状態を観察する。2秒後も塗膜が塗布時と同様の形態を保つ場合にはより表面張力の高い試験用混合液を塗布していき、正確に2秒だけぬらすことのできる混合液の表面張力を積層膜面の濡れ張力とする。
(5)150℃30分間加熱後の長手方向、幅方向の熱収縮率
ASTM−D−1204に従って、フィルムサンプルに200mm間隔で標点をつけ、加重をかけずに所定の温度のオーブンで所定の時間加熱処理を行い、熱処理後の標点座標を測定して、フィルム長手方法と幅方向の熱収縮率を下記式にて算出した。
熱収縮率(%)=(熱処理前標点間距離−熱処理後標点間距離)/熱処理前標点間距離×100
(6)積層膜側の面の水性ペン記入性
PILOT社製水性万年筆「カスタム743」を用いて、積層膜表面に30cmの直線を書き、記入後1分後に直線がはじいてとぎれてないか、もしくはにじんでないかどうか評価した。はじき・にじみなし:○、はじき・にじみあり:×と判定した。
(7)積層膜側の面の耐擦傷性
理研コランダム社製耐水研磨紙[タイプ:C34P、粒度:P2000]上に、ポリエステルフィルムを4cm×3cmの面積だけ積層膜を下にして接触させ、接触面上に断面積4cm×3cmの20gのおもりを載せ、4cmの距離を1秒間で滑らせて、取り出したフィルム片に目視できる擦り傷がついているかどうかをチェックした。目視判断時の環境は、光源は三波長蛍光灯(36ワット)とし、光源からフィルムサンプルを1.5m離し、目からフィルムの距離は20cm、光源とフィルムと目は直線上に位置し、透過光で傷を観察する。フィルム平面上に目の焦点をあて、フィルムを通して見える蛍光灯の像から1cm離れた場所の傷を観察する。裸眼もしくは矯正視力で1.2であることとする。擦り傷が見えれば×、見えなければ○と判定した。
以下に実施例を用いて本発明をさらに具体的に説明する。
The evaluation criteria in the present invention are as follows.
(1) Thickness of laminated film A cross-section of the laminated polyester film was cut out by a freezing ultrathin section method, and an acceleration voltage of 100 kV using a transmission electron microscope H-7100FA type manufactured by Hitachi, Ltd. by a stained ultrathin section method by RuO 4 staining. The laminated film portion was observed and photographed. From the cross-sectional photograph, the thicknesses of arbitrary five laminated films were calculated from the magnification and averaged.
(2) Center plane average roughness of the laminated film surface According to JIS-B-0601, the shape of an arbitrary straight line on the film laminated film was set to 80 using a stylus type three-dimensional roughness meter “ET4000AK” manufactured by Kosaka Laboratory. The measurement was performed at a location of 0.5 mm and the average roughness of the center plane was calculated by calculation of Cut Off 0.25 mm. The curvature of the contacting needle was 2.0 μmR.
(3) Total light transmittance and haze of laminated polyester film Using a fully automatic direct reading haze computer “HGM-2DP” manufactured by Suga Test Instruments Co., Ltd., for light having a wavelength of 550 nm, it was performed according to JIS-K-7105. .
(4) Wetting tension on the surface of the laminated film According to JIS-K-6768, the test mixed solution is applied to an area of 6 cm 2 with a cotton swab on the laminated film of the film, and the state of the coating film after 2 seconds is observed. If the coating film maintains the same form as when applied after 2 seconds, apply a test liquid mixture with a higher surface tension, and apply a surface tension of the liquid mixture that can be wetted accurately for 2 seconds. The surface wet tension.
(5) Thermal shrinkage in the longitudinal direction and width direction after heating at 150 ° C. for 30 minutes In accordance with ASTM-D-1204, the film samples are marked at intervals of 200 mm, and given in an oven at a predetermined temperature without applying a load. The heat treatment was carried out for a time, and the coordinates of the gauge points after the heat treatment were measured.
Thermal contraction rate (%) = (distance between the pre-heat treatment gauge points−distance between the heat treatment gauge points) / distance between the pre-heat treatment gauge points × 100
(6) Water-based pen fillability on the surface of the laminated film side Using a water-based fountain pen “Custom 743” manufactured by PILOT, write a 30 cm straight line on the surface of the laminated film. Or we evaluated whether it was blurred. No repelling / bleeding: ○, with repelling / bleeding: x.
(7) Scratch resistance on the surface of the laminated film side A polyester film is brought into contact with an area of 4 cm × 3 cm on the water-resistant abrasive paper [Type: C34P, particle size: P2000] manufactured by Riken Corundum, and contacted. A weight of 20 g having a cross-sectional area of 4 cm × 3 cm was placed on the surface, and the distance of 4 cm was slid for 1 second to check whether or not the removed film piece had a visible scratch. At the time of visual judgment, the light source is a three-wavelength fluorescent lamp (36 watts), the film sample is separated from the light source by 1.5 m, the distance from the eye to the film is 20 cm, the light source, the film and the eye are located on a straight line, and transmitted. Observe the wound with light. Focus the eyes on the plane of the film and observe a scratch 1 cm away from the fluorescent light image seen through the film. The naked eye or corrected visual acuity is 1.2. If the scratch was visible, it was judged as x.
Hereinafter, the present invention will be described more specifically with reference to examples.

実施例1
常法によりテレフタル酸とエチレングリコールを用いて重合したフィラーを含まないポリエチレンテレフタレートを280℃で溶融押出し、静電印可された25℃のキャストドラム上にキャストし無延伸シートとした後、これを100℃で予熱し、この温度にてロール延伸で長手方向に3.1倍延伸した。この後、ポリエステル樹脂A95.0wt%、メラミン系架橋剤5.0wt%の固形分濃度6.0%の水系塗料に易滑剤(粒径150nmのコロイダルシリカ)を水系塗料比0.06重量%で添加した塗布液を上記のフィルム両面に塗布した。塗布の計量には小林製作所製「メイヤーバー#4」(ワイヤー径0.1mm)をフリー回転で使用した。その後、120℃で幅方向に3.5倍延伸した。その後230℃で加熱しながら長手方向に4%収縮の弛緩処理、幅方向に6%収縮の弛緩処理を行った。これにより、総膜厚100nmの積層膜が両面に形成されたポリエチレンテレフタレートフィルムを基材とする125μm厚さの積層フィルムを得た。
Example 1
Polyethylene terephthalate containing no filler, polymerized using terephthalic acid and ethylene glycol by a conventional method, was melt-extruded at 280 ° C. and cast on an electrostatically applied 25 ° C. cast drum to obtain an unstretched sheet. Preheating was performed at 0 ° C., and the film was stretched 3.1 times in the longitudinal direction by roll stretching at this temperature. Thereafter, an easy-to-lubricant (colloidal silica having a particle size of 150 nm) was added to a water-based paint having a solid content concentration of 6.0% with a polyester resin A of 95.0 wt% and a melamine-based crosslinking agent of 5.0 wt% at a water-based paint ratio of 0.06 wt% The added coating solution was applied to both sides of the film. “Meyer bar # 4” (wire diameter: 0.1 mm) manufactured by Kobayashi Seisakusho was used for free coating rotation. Thereafter, the film was stretched 3.5 times in the width direction at 120 ° C. Then, while heating at 230 ° C., relaxation treatment with 4% shrinkage in the longitudinal direction and relaxation treatment with 6% shrinkage in the width direction were performed. As a result, a 125 μm thick laminated film having a base material of a polyethylene terephthalate film having a laminated film having a total film thickness of 100 nm formed on both surfaces was obtained.

この積層フィルムの特性を表1に示した。積層膜面の濡れ張力は45mN/m、中心面平均粗さは5.0nmであり、積層フィルムの全光線透過率は92.0%、ヘイズは0.8%、熱収縮率は長手方向0.5%、幅方向0.5%であった。積層膜面の水性ペン記入性、積層膜面の耐擦傷性とも○であり、電子ペーパーの表層部材として使用可能な積層ポリエステルフィルムであった。
ポリエステル樹脂A:テレフタル酸ジメチル、イソフタル酸、セバシン酸、無水トリメリット酸、エチレングリコール、1・4ブタンジオール、ネオペンチルグリコールの共重合組成体。
The characteristics of this laminated film are shown in Table 1. The wetting tension of the laminated film surface is 45 mN / m, the center plane average roughness is 5.0 nm, the total light transmittance of the laminated film is 92.0%, the haze is 0.8%, and the heat shrinkage is 0 in the longitudinal direction. 0.5% and 0.5% in the width direction. The water-based pen fillability on the laminated film surface and the scratch resistance on the laminated film surface were both good, and the laminated polyester film was usable as a surface layer member of electronic paper.
Polyester resin A: a copolymer composition of dimethyl terephthalate, isophthalic acid, sebacic acid, trimellitic anhydride, ethylene glycol, 1.4 butanediol, and neopentyl glycol.

実施例2
アクリル樹脂A80.0wt%、メラミン系架橋剤20.0wt%の固形分濃度9.0%の水系塗料に易滑剤(粒径300nmのコロイダルシリカ)を水系塗料比0.12重量%で添加した塗布液を実施例1と同等の方法で片面にのみ塗布し、幅方向延伸のあとの加熱しながらの弛緩処理を長手方向だけ中止し、それ以外は全て実施例1と同様の方法で製造した結果、総膜厚150nmの積層膜が片面に形成されたポリエチレンテレフタレートフィルムを基材とする125μm厚さの積層フィルムを得た。
Example 2
Application of acrylic resin A 80.0wt%, melamine-based crosslinking agent 20.0wt% solids concentration 9.0% water-based paint with easy lubricant (colloidal silica with a particle size of 300nm) added in water-based paint ratio 0.12wt% The liquid was applied only on one side in the same manner as in Example 1, and the relaxation treatment while heating after stretching in the width direction was stopped only in the longitudinal direction, and all the other results were produced in the same manner as in Example 1. A 125 μm-thick laminated film having a polyethylene terephthalate film having a total film thickness of 150 nm formed on one side as a base material was obtained.

この積層フィルムの特性を表1に示した。積層膜面の濡れ張力は37mN/m、中心面平均粗さは8.0nmであり、積層フィルムの全光線透過率は91.6%、ヘイズは0.7%、熱収縮率は長手方向1.0%、幅方向0.5%であった。積層膜面の水性ペン記入性、積層膜面の耐擦傷性とも○であり、積層膜をA側に向ければ電子ペーパーの表層部材として使用可能な積層ポリエステルフィルムであった。
アクリル樹脂A:メチルメタクリレート、エチルアクリレート、Nメチロールアクリルアミド、アクリル酸の共重合組成体。
The characteristics of this laminated film are shown in Table 1. The wetting tension of the laminated film surface is 37 mN / m, the center plane average roughness is 8.0 nm, the total light transmittance of the laminated film is 91.6%, the haze is 0.7%, and the heat shrinkage rate is 1 in the longitudinal direction. 0.0% and 0.5% in the width direction. The water-based pen fillability of the laminated film surface and the scratch resistance of the laminated film surface were both good, and the laminated polyester film was usable as a surface layer member of electronic paper when the laminated film was directed to the A side.
Acrylic resin A: Copolymerized composition of methyl methacrylate, ethyl acrylate, N methylol acrylamide and acrylic acid.

実施例3
アクリル樹脂A78.0wt%、帯電防止剤A20.0wt%、メラミン系架橋剤2.0wt%の固形分濃度2.1%の水系塗料に易滑剤(粒径80nmのコロイダルシリカ)を水系塗料比0.12重量%で添加した塗布液を実施例1と同等の方法で両面に塗布し、それ以外は全て実施例1と同様の方法で製造した結果、総膜厚35nmの積層膜が両面に形成されたポリエチレンテレフタレートフィルムを基材とする125μm厚さの積層フィルムを得た。
Example 3
An acrylic resin A 78.0 wt%, antistatic agent A 20.0 wt%, melamine crosslinking agent 2.0 wt% solid content concentration 2.1% water-based paint and easy-to-lubricant (colloidal silica with a particle size of 80 nm) water-based paint ratio 0 The coating solution added at 12% by weight was coated on both sides by the same method as in Example 1, and all other parts were manufactured by the same method as in Example 1. As a result, a laminated film having a total film thickness of 35 nm was formed on both sides. A laminated film having a thickness of 125 μm was obtained using the obtained polyethylene terephthalate film as a base material.

この積層フィルムの特性を表1に示した。積層膜面の濡れ張力は57mN/m、中心面平均粗さは3.0nmであり、積層フィルムの全光線透過率は91.5%、ヘイズは0.4%、熱収縮率は長手方向0.5%、幅方向0.5%であった。積層膜面の水性ペン記入性、積層膜面の耐擦傷性とも○であり、積層膜面をA側にする場合には、電子ペーパーの表層部材として使用可能な積層ポリエステルフィルムであった。
帯電防止剤A:ポリスチレンのスルホン化物及びその軽金属塩。
The characteristics of this laminated film are shown in Table 1. The wetting tension of the laminated film surface is 57 mN / m, the center plane average roughness is 3.0 nm, the total light transmittance of the laminated film is 91.5%, the haze is 0.4%, and the heat shrinkage is 0 in the longitudinal direction. 0.5% and 0.5% in the width direction. The water-based pen fillability of the laminated film surface and the scratch resistance of the laminated film surface were both good, and when the laminated film surface was on the A side, it was a laminated polyester film that could be used as a surface layer member of electronic paper.
Antistatic agent A: sulfonated polystyrene and light metal salt thereof.

比較例1
実施例1の水系塗料の固形分を0.3%に薄め易滑剤(粒径15nmのコロイダルシリカ)を水系塗料比0.04重量%で添加した塗布液を実施例1と同等の方法で片面にのみ塗布し、かつもう片方の面には実施例1と同じ水系塗料(易滑材も実施例1と同様)を塗布し、それ以外は全て実施例1と同様の方法で製造した結果、片方の面には総膜厚5nmの積層膜が形成され、もう片方の面に実施例1と同様の積層膜を形成したポリエチレンテレフタレートフィルムを基材とする125μm厚さの積層フィルムを得た。
Comparative Example 1
One side of the coating liquid obtained by thinning the solid content of the water-based paint of Example 1 to 0.3% and adding an easy lubricant (colloidal silica having a particle size of 15 nm) at a water-based paint ratio of 0.04% by weight in the same manner as in Example 1 As a result of applying the same water-based paint as in Example 1 (sliding material is also the same as in Example 1) on the other side, and producing everything else by the same method as in Example 1, A laminated film having a total film thickness of 5 nm was formed on one surface, and a 125 μm thick laminated film having a base material of a polyethylene terephthalate film having the same laminated film as that of Example 1 formed on the other surface was obtained.

この積層フィルムの特性を表1に示した。この積層フィルムの総膜厚5nmの方の積層膜をA側に向けた場合、A側の積層膜面の濡れ張力は45mN/mであったが、中心面平均粗さは積層膜の厚さが十分でなく易滑剤に径の大きなものを選べなかったため0.8nmであった。積層フィルムの全光線透過率は91.0%、ヘイズは0.5%、熱収縮率は長手方向0.5%、幅方向0.5%であった。積層膜面の水性ペン記入性は○であったが、積層膜面の耐擦傷性は×であり、電子ペーパーの表層部材としては使用することができない積層ポリエステルフィルムであった。   The characteristics of this laminated film are shown in Table 1. When the laminated film having a total film thickness of 5 nm was directed to the A side, the wetting tension of the laminated film surface on the A side was 45 mN / m, but the center plane average roughness was the thickness of the laminated film. Was not sufficient, and it was not possible to select a lubricant having a large diameter. The total light transmittance of the laminated film was 91.0%, haze was 0.5%, and heat shrinkage was 0.5% in the longitudinal direction and 0.5% in the width direction. The water-based pen fillability of the laminated film surface was good, but the scratch resistance of the laminated film surface was x, and it was a laminated polyester film that could not be used as a surface layer member of electronic paper.

比較例2
実施例1の水系塗料の固形分を24.0%に濃度を上げ易滑剤(粒径500nmのコロイダルシリカ)を水系塗料比0.08重量%で添加した塗布液を実施例1と同等の方法で片面にのみ塗布し、かつもう片方の面には実施例1と同じ水系塗料(易滑材も実施例1と同様)を塗布し、それ以外は全て実施例1と同様の方法で製造した結果、片方の面には総膜厚400nmの積層膜が形成され、もう片方の面に実施例1と同様の積層膜を形成したポリエチレンテレフタレートフィルムを基材とする125μm厚さの積層フィルムを得た。
Comparative Example 2
A coating solution obtained by increasing the solid content of the water-based paint of Example 1 to 24.0% and adding a lubricant (colloidal silica having a particle size of 500 nm) at a water-based paint ratio of 0.08% by weight is the same method as in Example 1. And the other side was coated with the same water-based paint as in Example 1 (sliding material was also the same as in Example 1), and everything else was produced in the same manner as in Example 1. As a result, a laminated film having a total thickness of 400 nm is formed on one side, and a 125 μm-thick laminated film based on a polyethylene terephthalate film on which the same laminated film as in Example 1 is formed on the other side is obtained. It was.

この積層フィルムの特性を表1に示した。この積層フィルムの総膜厚400nmの方の積層膜をA側に向けた場合、A側の積層膜面の濡れ張力は45mN/mであり、中心面平均粗さは10.0nmであった。積層フィルムの全光線透過率は91.5%であったが、ヘイズは1.8%で使用不可能なレベルではないが少し高く画面が少し白く見える電子ペーパーであった。熱収縮率は長手方向0.5%、幅方向0.5%であった。積層膜面の水性ペン記入性は○であったが、ロール製品でのブロッキングのため元々フィルム表層に傷と積層膜はがれ物がついており、積層膜面の耐擦傷性試験をやるまでもなく外観は×であった。そのため電子ペーパーの表層部材としては使用することができない積層ポリエステルフィルムであった。   The characteristics of this laminated film are shown in Table 1. When the laminated film having a total film thickness of 400 nm of this laminated film was directed to the A side, the wetting tension of the laminated film surface on the A side was 45 mN / m, and the center plane average roughness was 10.0 nm. The total light transmittance of the laminated film was 91.5%, but the haze was 1.8%, which was not an unusable level, but it was an electronic paper that looked slightly higher and the screen looked a little white. The heat shrinkage rate was 0.5% in the longitudinal direction and 0.5% in the width direction. The water-based pen fillability on the laminated film surface was ○, but due to blocking with roll products, the film surface was originally scratched and peeled off from the laminated film, and the appearance did not need to be tested on the laminated film surface. Was x. Therefore, it was a laminated polyester film that could not be used as a surface layer member of electronic paper.

比較例3
実施例2で製造した片面積層フィルムを、積層膜面側ではなく、積層膜を設置していないフィルム基材裸面をA側として使用する検討を実施した。
Comparative Example 3
The single-area layer film produced in Example 2 was examined using the bare film surface with no laminated film as the A side instead of the laminated film surface side.

この積層フィルムの特性を表1に示した。ポリエステル基材裸面の濡れ張力は37mN/m、中心面平均粗さは0.5nmであり、積層膜面の水性ペン記入性は○であったが、積層膜面の耐擦傷性は×であり、積層膜が表層を向いていなければ電子ペーパーの表層部材としては使えないことが分かった。   The characteristics of this laminated film are shown in Table 1. The wetting tension of the bare polyester substrate surface was 37 mN / m, the average roughness of the center plane was 0.5 nm, and the aqueous pen entry on the laminated film surface was ○, but the scratch resistance of the laminated film surface was x. In other words, it was found that the laminated film cannot be used as a surface layer member of electronic paper unless it faces the surface layer.

比較例4
実施例1の水系塗料に易滑剤(粒径300nmのコロイダルシリカ)を水系塗料比0.24重量%で添加した塗布液を実施例1と同等の方法で片面にのみ塗布し、かつもう片方の面には実施例1と同じ水系塗料(易滑材も実施例1と同様)を塗布し、それ以外は全て実施例1と同様の方法で製造した結果、総膜厚100nmの積層膜が両面に形成されたポリエチレンテレフタレートフィルムを基材とする125μm厚さの積層フィルムを得た。
Comparative Example 4
A coating solution obtained by adding a lubricant (colloidal silica having a particle size of 300 nm) to the water-based paint of Example 1 at a water-based paint ratio of 0.24% by weight was applied only on one side in the same manner as in Example 1, and the other side The surface was coated with the same water-based paint as in Example 1 (easy-sliding material was the same as in Example 1), and everything else was manufactured in the same manner as in Example 1. As a result, a laminated film having a total film thickness of 100 nm was formed on both sides. A laminated film having a thickness of 125 μm was obtained using the polyethylene terephthalate film formed on the substrate as a base material.

この積層フィルムの特性を表1に示した。この積層フィルムの粒径300nmのコロイダルシリカを0.24重量%で添加した方の積層膜をA側に向けた場合、A側の積層膜面の濡れ張力は45mN/mであったが、中心面平均粗さは13.0nmであり、積層フィルムの全光線透過率は91.8%であったが、ヘイズは2.2%で画面が少し白く見えるため電子ペーパーの表層部材としては使用することができない積層ポリエステルフィルムであった。熱収縮率は長手方向0.5%、幅方向0.5%であり、積層膜面の水性ペン記入性、積層膜面の耐擦傷性とも○であった。   The characteristics of this laminated film are shown in Table 1. When the laminated film to which 0.24% by weight of colloidal silica having a particle size of 300 nm was added was directed to the A side, the wetting tension of the laminated film surface on the A side was 45 mN / m. The surface average roughness was 13.0 nm, and the total light transmittance of the laminated film was 91.8%. However, the haze is 2.2% and the screen looks a little white, so it is used as a surface layer member of electronic paper. It was a laminated polyester film that could not. The heat shrinkage ratio was 0.5% in the longitudinal direction and 0.5% in the width direction, and both the aqueous pen fillability on the laminated film surface and the scratch resistance on the laminated film surface were good.

比較例5
常法によりテレフタル酸とエチレングリコールを用いて重合したポリエチレンテレフタレートに粒径2.5μmのシリカのフィラーを原料比0.06重量%添加したものを280℃で溶融押出し、積層膜については実施例1と同様のものを片面だけに塗布し、それ以外は全て実施例1と同様の方法で製造した結果、総膜厚100nmの積層膜が片面に形成されたポリエチレンテレフタレートフィルムを基材とする125μm厚さの積層フィルムを得た。
Comparative Example 5
A polyethylene terephthalate polymerized with terephthalic acid and ethylene glycol by a conventional method and 0.06% by weight of a silica filler having a particle size of 2.5 μm added is melt-extruded at 280 ° C. As a result of applying the same material to only one side, and producing everything else by the same method as in Example 1, a thickness of 125 μm based on a polyethylene terephthalate film having a laminated film with a total film thickness of 100 nm formed on one side Sano laminated film was obtained.

この積層フィルムの特性を表1に示した。積層膜面の濡れ張力は45mN/m、中心面平均粗さは5.0nmであり、熱収縮率は長手方向0.5%、幅方向0.5%であった。積層膜面の水性ペン記入性、積層膜面の耐擦傷性とも○であった。但し積層フィルムの全光線透過率は88.5%、ヘイズは10.0%であり、画面が白く見えること、及び全体的に輝度が足りなくなることから、電子ペーパーの表層部材としては使用することができない積層ポリエステルフィルムであった。   The characteristics of this laminated film are shown in Table 1. The wetting tension of the laminated film surface was 45 mN / m, the center surface average roughness was 5.0 nm, and the thermal shrinkage rate was 0.5% in the longitudinal direction and 0.5% in the width direction. Both the water-based pen fillability of the laminated film surface and the scratch resistance of the laminated film surface were good. However, the total light transmittance of the laminated film is 88.5%, the haze is 10.0%, the screen looks white, and the overall brightness is insufficient, so it should be used as a surface layer member of electronic paper. It was a laminated polyester film that could not be.

Figure 2008001050
Figure 2008001050

本発明は電子ペーパーの表層基材として特に有効に利用できる。直接水性ペンで字を書くことができる機能とあわせ、ハードコートを使用しない点から気軽に字を書き込めるだけの低コストを実現できる手段となり得るため、紙との置き換えを現実的に可能とし、紙の地球規模的使用量の削減に寄与できる。
しかし本発明の利用可能性は上記に限定されるものではなく、光学用途に好適に使用され、それ以外でも高透明、低ヘイズを要求するあらゆる部材に対して好適に使用可能である。
The present invention can be particularly effectively used as a surface layer base material for electronic paper. Along with the ability to write characters directly with a water-based pen, it can be a low-cost way to easily write characters from the point of not using a hard coat. Can contribute to the reduction of the global usage.
However, the applicability of the present invention is not limited to the above, and is preferably used for optical applications, and can be suitably used for any member that requires high transparency and low haze.

Claims (8)

電子ペーパー用のポリエステルフィルムであって、該ポリエステルフィルムは少なくとも片面に厚さ10〜350nmの積層膜を有し、該積層膜表面における中心面平均粗さが1.0〜12.0nmであり、全光線透過率が90.5%以上であることを特徴とする電子ペーパー用積層ポリエステルフィルム。 A polyester film for electronic paper, the polyester film has a laminated film having a thickness of 10 to 350 nm on at least one surface, and a center plane average roughness on the surface of the laminated film is 1.0 to 12.0 nm, A laminated polyester film for electronic paper, wherein the total light transmittance is 90.5% or more. 積層膜表面における濡れ張力が25〜70mN/mである請求項1に記載の電子ペーパー用積層ポリエステルフィルム。 The laminated polyester film for electronic paper according to claim 1, wherein the wetting tension on the surface of the laminated film is 25 to 70 mN / m. ヘイズが2.0%以下である請求項1または2に記載の電子ペーパー用積層ポリエステルフィルム。 The laminated polyester film for electronic paper according to claim 1 or 2, wherein the haze is 2.0% or less. 積層膜が電子ペーパーの、人が触れる側(A側)の最外層として用いられる請求項1〜3のいずれかに記載の電子ペーパー用積層ポリエステルフィルム。 The laminated polyester film for electronic paper according to any one of claims 1 to 3, wherein the laminated film is used as an outermost layer on the side (A side) touched by a person of electronic paper. ポリエステルフィルムが、ポリエチレンテレフタレートフィルムである請求項1〜4のいずれかに記載の電子ペーパー用積層ポリエステルフィルム。 The laminated polyester film for electronic paper according to any one of claims 1 to 4, wherein the polyester film is a polyethylene terephthalate film. 150℃で30分加熱後の熱収縮率が長手方向、幅方向いずれも2.0%以下である請求項1〜5のいずれかに記載の電子ペーパー用積層ポリエステルフィルム。 The laminated polyester film for electronic paper according to any one of claims 1 to 5, wherein a heat shrinkage ratio after heating at 150 ° C for 30 minutes is 2.0% or less in both the longitudinal direction and the width direction. 請求項1〜6のいずれかに記載の積層ポリエステルフィルムを用いた電子ペーパー。 Electronic paper using the laminated polyester film according to claim 1. 請求項1〜6のいずれかに記載の積層ポリエステルフィルムの片面に透明電極を設け、その反対面の積層膜の上にハードコートを設けず電子ペーパーの部材として使用する電子ペーパーの製造方法。 The manufacturing method of the electronic paper which provides a transparent electrode in the single side | surface of the laminated polyester film in any one of Claims 1-6, and does not provide a hard-coat on the laminated film of the opposite surface, and uses it as a member of electronic paper.
JP2006174953A 2006-06-26 2006-06-26 Laminated polyester film for electronic paper, electronic paper using the same, and manufacturing method of elecronic paper using the same Pending JP2008001050A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010149521A (en) * 2008-08-08 2010-07-08 Toyobo Co Ltd Heat-shrinkable polyester film
US20110143123A1 (en) * 2008-08-08 2011-06-16 Toyo Boseki Kabushiki Kaisha Heat shrinkable polyester film
WO2014084008A1 (en) * 2012-11-27 2014-06-05 東レフィルム加工株式会社 Hard coat film and transparent conducting film
JP2015205439A (en) * 2014-04-19 2015-11-19 三菱樹脂株式会社 Base material for protective film for electroconductive film

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010149521A (en) * 2008-08-08 2010-07-08 Toyobo Co Ltd Heat-shrinkable polyester film
US20110143123A1 (en) * 2008-08-08 2011-06-16 Toyo Boseki Kabushiki Kaisha Heat shrinkable polyester film
US8911839B2 (en) 2008-08-08 2014-12-16 Toyo Boseki Kabushiki Kaisha Heat shrinkable polyester film
WO2014084008A1 (en) * 2012-11-27 2014-06-05 東レフィルム加工株式会社 Hard coat film and transparent conducting film
JP5528645B1 (en) * 2012-11-27 2014-06-25 東レフィルム加工株式会社 Hard coat film and transparent conductive film
JP2015205439A (en) * 2014-04-19 2015-11-19 三菱樹脂株式会社 Base material for protective film for electroconductive film

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