JP6113555B2 - Optical film - Google Patents

Description

  The present invention relates to an optical film.

  In recent years, display devices such as flat panel displays (FPDs: for example, liquid crystal display devices and organic EL display devices) are becoming lighter and thinner. In order to reduce the weight and thickness of the display device, it has been proposed to use a substrate including an optical film formed of a resin instead of a conventional glass substrate as a substrate of the display device (for example, Patent Document 1, 2, 3). The optical fill alone or in combination with thin glass constitutes the substrate. If an optical film formed from a resin is used, a lightweight and thin substrate can be obtained. However, an optical film formed from a conventional resin has a problem that a phase difference is large and adversely affects display characteristics of a display device. In addition, the optical film has poor heat resistance and has problems such as deterioration due to exposure to a high temperature in the manufacturing process of the display device and dimensional change.

JP 11-329715 A JP 2008-107510 A Special Table 2002-542971

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical film having excellent heat resistance and a small retardation.

式（ａ１）および（ａ２）中、Ｚ^１１、Ｚ^１２、Ｚ^２１およびＺ^２２はそれぞれ独立して、シクロアルカンまたは芳香族環を含む置換基であり、Ｒ^１１、Ｒ^１２、Ｒ^２１およびＲ^２２はそれぞれ独立して、水素原子、シクロアルカン、芳香族環または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、Ｒ^１３〜Ｒ^１６およびＲ^２３〜Ｒ^２６はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、Ａ^１１、Ａ^１２、Ａ^２１およびＡ^２２はそれぞれ独立して上記一般式（１）〜（５）で表される連結基から選ばれる少なくとも１種であり、Ｘ^１１は、パラ位またはメタ位で、該連結基Ａ^１２と、該連結基Ａ^１１またはＡ^２１とに連結する１個以上の芳香族環であり、Ｘ^２１は、パラ位またはメタ位で、該連結基Ａ^２２と、該連結基Ａ^２１またはＡ^１１とに連結する１個以上の芳香族環である。
好ましい実施形態においては、上記芳香族系樹脂が、下記一般式（ｂ１）〜（ｂ４）で表される繰り返し単位から選ばれる少なくとも１種の繰り返し単位をさらに有する。

式（ｂ１）〜（ｂ４）中、Ｒ^３３〜Ｒ^３６、Ｒ^４３〜Ｒ^４６、Ｒ^５３〜Ｒ^５６およびＲ^６３〜Ｒ^６６、はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、Ａ^３１、Ａ^３２、Ａ^４１、Ａ^４２、Ａ^５１、Ａ^５２、Ａ^６１およびＡ^６２はそれぞれ独立して上記一般式（１）〜（５）で表される連結基から選ばれる少なくとも１種であり、式（ｂ１）中、Ｘ^３１は、パラ位またはメタ位で、該連結基Ａ^３２と、該連結基Ａ^３１、前記式（ａ１）中のＡ^１１、前記式（ａ２）中のＡ^２１、該式（ｂ２）中のＡ^４１、該式（ｂ３）中のＡ^５１または該式（ｂ４）中のＡ^６１とに連結する１個以上の芳香族環であり、（ｂ２）中、Ｒ^４７〜Ｒ^５０はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、Ｘ^４１は、パラ位またはメタ位で、該連結基Ａ^４２と、該連結基Ａ^４１、前記式（ａ１）中のＡ^１１、前記式（ａ２）中のＡ^２１、該式（ｂ１）中のＡ^３１、該式（ｂ３）中のＡ^５１または該式（ｂ４）中のＡ^６１とに連結する１個以上の芳香族環であり、式（ｂ３）中、Ｒ^５７〜Ｒ^５９はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、Ｘ^５１は、パラ位またはメタ位で、該連結基Ａ^５２と、該連結基Ａ^５１、前記式（ａ１）中のＡ^１１、前記式（ａ２）中のＡ^２１、該式（ｂ１）中のＡ^３１、該式（ｂ２）中のＡ^４１または該式（ｂ４）中のＡ^６１とに連結する１個以上の芳香族環であり、式（ｂ４）中、Ｒ^６７およびＲ^６８はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基である。Ｒ^６９およびＲ^７０はそれぞれ独立して、水素原子、炭素数が１〜５の直鎖状もしくは分岐状のアルキル基、ハロゲン原子、メチルエチニル基、フェニルエチニル基、エチルエチニル基またはアルコキシ基であり、Ｘ^６１は、パラ位またはメタ位で、該連結基Ａ^６２と、該連結基Ａ^６１、前記式（ａ１）中のＡ^１１、前記式（ａ２）中のＡ^２１、該式（ｂ１）中のＡ^３１、該式（ｂ２）中のＡ^４１または該式（ｂ３）中のＡ^５１とに連結する１個以上の芳香族環である。
好ましい実施形態においては、本発明の光学フィルムは、面内位相差Ｒｅが、２０ｎｍ以下である。
好ましい実施形態においては、本発明の光学フィルムは、厚み方向の位相差Ｒｔｈが、１００ｎｍ以下である。
好ましい実施形態においては、本発明の光学フィルムは、全光線透過率が、８５％以上である。
好ましい実施形態においては、上前記芳香族系樹脂のガラス転移温度が、２００℃以上である。
好ましい実施形態においては、上記芳香族系樹脂の重量平均分子量が、ポリスチレン換算で、４００００〜２０００００である。
好ましい実施形態においては、上記芳香族系樹脂が、トルエンおよび／またはキシレンを５０％以上含有する溶媒に可溶である。
本発明の別の局面によれば、透明基板が提供される。この透明基板は上記光学フィルムと、厚さが１００μｍ以下の無機ガラスとを備える。
好ましい実施形態においては、上記透明基板は、総厚が１５０μｍ以下である。
好ましい実施形態においては、上記透明基板は、クラックを入れ屈曲させた際の破断直径が５０ｍｍ以下である。
本発明のさらに別の局面によれば、表示素子が提供される。この表示素子は、上記光学フィルムを用いて作製される。
本発明のさらに別の局面によれば、太陽電池が提供される。この太陽電池は、上記光学フィルムを用いて作製される。
本発明のさらに別の局面によれば、照明素子が提供される。この照明素子は、上記光学フィルムを用いて作製される。 The optical film of the present invention has at least one repeating unit selected from a repeating unit represented by the following general formula (a1) and a repeating unit represented by the following general formula (a2).

In the formulas (a1) and (a2), Z ¹¹ , Z ¹² , Z ²¹ and Z ²² are each independently a substituent containing a cycloalkane or an aromatic ring, and R ¹¹ , R ¹² , R ²¹ and R ²² are each independently a hydrogen atom, a cycloalkane, an aromatic ring, or a linear or branched alkyl group having 1 to 5 carbon atoms, and R ^{13 to} R ¹⁶ and R ^{23 to} R ²⁶ are each independently And a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, and A ¹¹ , A ¹² , A ²¹ and A ²² are each independently the above general formulas (1) to (5 And at least one selected from the linking group represented by formula (I), wherein X ¹¹ is a para-position or a meta-position and is linked to the linking group A ¹² and the linking group A ¹¹ or A ²¹ . an aromatic ring, X ¹ is a para or meta position, and the linking group A ^22, a one or more aromatic ring connected to the said linking group A ²¹ or A ^11.
In a preferred embodiment, the aromatic resin further has at least one repeating unit selected from repeating units represented by the following general formulas (b1) to (b4).

In formulas (b1) to (b4), R ^{33 to} R ³⁶ , R ^{43 to} R ⁴⁶ , R ^{53 to} R ⁵⁶ and R ^{63 to} R ⁶⁶ are each independently a hydrogen atom or a carbon number of 1 to 5 A linear or branched alkyl group, and A ³¹ , A ³² , A ⁴¹ , A ⁴² , A ⁵¹ , A ⁵² , A ⁶¹ and A ⁶² are each independently the above general formulas (1) to (5) In formula (b1), X ³¹ is a para-position or a meta-position, and the linking group A ³² , the linking group A ³¹ , or the formula (a1) 1 linked to A ^{11 in} the formula, A ^{21 in} the formula (a2), A ^{41 in} the formula (b2), A ⁵¹ in the formula (b3), or A ⁶¹ in the formula (b4) a more aromatic rings, in ^{(b2), R} 47 ~R ⁵⁰ are each independently hydrogen atoms Or a linear or branched alkyl group having 1 to 5 carbon ^{atoms, X 41} is a para or meta position, and the linking group ^{A 42,} the linking group ^{A 41,} the formula (a1) in One or more linked to A ¹¹ of formula (a2), A ²¹ in formula (b1), A ³¹ in formula (b1), A ⁵¹ in formula (b3) or A ⁶¹ in formula (b4) In formula (b3), R ^{57 to} R ⁵⁹ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, and X ⁵¹ is In the para or meta position, the linking group A ⁵² , the linking group A ⁵¹ , A ^{11 in} the formula (a1), A ^{21 in} the formula (a2), A ³¹ in the formula (b1), One or more aromatic rings linked to A ⁴¹ in the formula (b2) or A ⁶¹ in the formula (b4), and the formula (b4 In general, R ⁶⁷ and R ⁶⁸ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms. R ⁶⁹ and R ⁷⁰ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, a halogen atom, a methylethynyl group, a phenylethynyl group, an ethylethynyl group, or an alkoxy group. X ⁶¹ is a para-position or a meta-position, the linking group A ⁶² , the linking group A ⁶¹ , A ^{11 in} the formula (a1), A ^{21 in} the formula (a2), the formula (b1) ^{a 31} in a one or more aromatic rings coupled to the ^{a 51} in formula (b2) ^{a 41} or formula (b3) in.
In a preferred embodiment, the optical film of the present invention has an in-plane retardation Re of 20 nm or less.
In a preferred embodiment, the optical film of the present invention has a thickness direction retardation Rth of 100 nm or less.
In a preferred embodiment, the optical film of the present invention has a total light transmittance of 85% or more.
In a preferred embodiment, the glass transition temperature of the aromatic resin is 200 ° C. or higher.
In preferable embodiment, the weight average molecular weights of the said aromatic resin are 40000-200000 in polystyrene conversion.
In a preferred embodiment, the aromatic resin is soluble in a solvent containing 50% or more of toluene and / or xylene.
According to another aspect of the present invention, a transparent substrate is provided. The transparent substrate includes the optical film and an inorganic glass having a thickness of 100 μm or less.
In a preferred embodiment, the transparent substrate has a total thickness of 150 μm or less.
In a preferred embodiment, the transparent substrate has a fracture diameter of 50 mm or less when cracked and bent.
According to still another aspect of the present invention, a display element is provided. This display element is produced using the optical film.
According to still another aspect of the present invention, a solar cell is provided. This solar cell is produced using the optical film.
According to still another aspect of the present invention, a lighting element is provided. This illumination element is manufactured using the optical film.

  According to the present invention, by using an aromatic resin having a specific repeating unit, it is possible to provide an optical film that is excellent in heat resistance and has a small in-plane retardation and a retardation in the thickness direction.

It is a schematic sectional drawing of the transparent substrate by preferable embodiment of this invention.

式（ａ１）および（ａ２）中、Ｚ^１１、Ｚ^１２、Ｚ^２１およびＺ^２２はそれぞれ独立して、シクロアルカンまたは芳香族環を含む置換基であり、好ましくは炭素数が５〜６のシクロアルカンまたは１個〜２個の芳香族環であり、より好ましくは炭素数が５〜６のシクロアルカンであり、特に好ましくは炭素数６のシクロアルカンである。Ｒ^１１、Ｒ^１２、Ｒ^２１およびＲ^２２はそれぞれ独立して、水素原子、シクロアルカン、芳香族環または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、好ましくは水素原子、炭素数が５〜６のシクロアルカン、芳香族環または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、より好ましくは水素原子、メチル基またはｔ−ブチル基である。Ｒ^１３〜Ｒ^１６およびＲ^２３〜Ｒ^２６はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、より好ましくは水素原子、メチル基またはｔ−ブチル基である。Ａ^１１、Ａ^１２、Ａ^２１およびＡ^２２は、それぞれ独立して上記一般式（１）〜（５）で表される連結基から選ばれる少なくとも１種であり、好ましくは上記一般式（１）〜（３）で表される連結基から選ばれる少なくとも１種であり、より好ましくは上記一般式（１）で表される連結基である。Ｘ^１１は、パラ位またはメタ位で連結基Ａ^１２と連結基Ａ^１１またはＡ^２１とに連結する１個以上の芳香族環である。Ｘ^１１は、好ましくは１個〜２個の芳香族環であり、より好ましくは１個の芳香族環である。Ｘ^２１は、パラ位またはメタ位で連結基Ａ^２２と連結基Ａ^２１またはＡ^１１とに連結する１個以上の芳香族環である。Ｘ^２１は、好ましくは１個〜２個の芳香族環であり、より好ましくは１個の芳香族環である。なお、上記Ｚ^１１、Ｚ^１２、Ｚ^２１、Ｚ^２２、Ｒ^１１、Ｒ^１２、Ｒ^２１、Ｒ^２２、Ｘ^１１およびＸ^２１の芳香族環またはシクロアルカンは置換基を有していてもよく、有していなくてもよい。また、後述のように、芳香族系樹脂が繰り返し単位（Ｂ）を有する場合、Ｘ^１１は、パラ位またはメタ位で、繰り返し単位（ｂ１）の連結基Ａ^３１、繰り返し単位（ｂ２）の連結基Ａ^４１、繰り返し単位（ｂ３）の連結基Ａ^５１または繰り返し単位（ｂ４）の連結基Ａ^６１とも連結し得る。 A. Optical film
A-1. Aromatic resin The optical film of the present invention comprises a repeating unit represented by the following general formula (a1) (hereinafter also referred to as repeating unit (a1)) and a repeating unit represented by the following general formula (a2) (hereinafter referred to as “repeating unit”). An aromatic resin having at least one repeating unit selected from repeating units (a2). If the aromatic resin has such a repeating unit, an optical film having excellent heat resistance and a small retardation can be obtained. In the present specification, the repeating unit represented by the following general formula (a1) and the repeating unit represented by the following general formula (a2) are collectively referred to as “repeating unit (A)”.

In the formulas (a1) and (a2), Z ¹¹ , Z ¹² , Z ²¹ and Z ²² are each independently a substituent containing a cycloalkane or an aromatic ring, preferably a cyclohexane having 5 to 6 carbon atoms. It is an alkane or 1 to 2 aromatic rings, more preferably a cycloalkane having 5 to 6 carbon atoms, and particularly preferably a cycloalkane having 6 carbon atoms. R ¹¹ , R ¹² , R ²¹ and R ²² are each independently a hydrogen atom, a cycloalkane, an aromatic ring or a linear or branched alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom , A cycloalkane having 5 to 6 carbon atoms, an aromatic ring or a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a methyl group or a t-butyl group. R ^{13 to} R ¹⁶ and R ^{23 to} R ²⁶ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a methyl group or t- It is a butyl group. A ¹¹ , A ¹² , A ²¹ and A ²² are each independently at least one selected from the linking groups represented by the general formulas (1) to (5), preferably the general formula (1). It is at least 1 sort (s) chosen from the coupling group represented by-(3), More preferably, it is a coupling group represented by the said General formula (1). X ¹¹ is one or more aromatic rings linked to the linking group A ¹² and the linking group A ¹¹ or A ²¹ at the para or meta position. X ¹¹ is preferably 1 to 2 aromatic rings, and more preferably 1 aromatic ring. X ²¹ is one or more aromatic rings linked to the linking group A ²² and the linking group A ²¹ or A ¹¹ at the para or meta position. X ²¹ is preferably 1 to 2 aromatic rings, and more preferably 1 aromatic ring. The aromatic ring or cycloalkane of Z ¹¹ , Z ¹² , Z ²¹ , Z ²² , R ¹¹ , R ¹² , R ²¹ , R ²² , X ¹¹ and X ²¹ may have a substituent, It may not have. As will be described later, when the aromatic resin has a repeating unit (B), X ¹¹ is a para-position or a meta-position, and the linking group A ^{31 of} the repeating unit (b1) is connected to the repeating unit (b2). It can also be linked to the group A ⁴¹ , the linking group A ⁵¹ of the repeating unit (b3) or the linking group A ⁶¹ of the repeating unit (b4).

  In the aromatic resin, the total content of the repeating unit (a1) and the repeating unit (a2) is preferably 5 mol% to 100 mol% with respect to the total number of moles of the repeating units constituting the aromatic resin. More preferably, it is 10 mol%-90 mol%, Most preferably, it is 20 mol%-80 mol%. Within such a range, an optical film having excellent heat resistance and a small retardation can be obtained.

  In the aromatic resin, the content ratio of the repeating unit (a1) to the repeating unit (a2) can be set to any appropriate value. The glass transition temperature of the aromatic resin can be controlled by the content ratio of the repeating unit (a1) and the repeating unit (a2). Specifically, when many repeating units (a1) are included, the glass transition temperature of the aromatic resin can be increased. In one embodiment, the molar ratio (a1: a2) of the repeating unit (a1) to the repeating unit (a2) is 100: 0. In another embodiment, the molar ratio (a1: a2) of the repeating unit (a1) to the repeating unit (a2) is 0: 100. When the aromatic resin has a repeating unit (a1) and a repeating unit (a2), the molar ratio (a1: a2) is preferably 80:20 to 20:80, more preferably 60 : 40 to 40:60.

式（ｂ１）〜（ｂ４）中、Ｒ^３３〜Ｒ^３６、Ｒ^４３〜Ｒ^４６、Ｒ^５３〜Ｒ^５６およびＲ^６３〜Ｒ^６６、はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、より好ましくは水素原子、メチル基またはｔ−ブチル基である。Ａ^３１、Ａ^３２、Ａ^４１、Ａ^４２、Ａ^５１、Ａ^５２、Ａ^６１およびＡ^６２はそれぞれ独立して上記一般式（１）〜（５）で表される連結基から選ばれる少なくとも１種であり、好ましくは上記一般式（１）〜（３）で表される連結基から選ばれる少なくとも１種であり、より好ましくは上記一般式（１）で表される連結基である。
式（ｂ１）中、Ｘ^３１は、パラ位またはメタ位で、連結基Ａ^３２と、連結基Ａ^３１、上記式（ａ１）中の連結基Ａ^１１、上記式（ａ２）中の連結基Ａ^２１、上記式（ｂ２）中の連結基Ａ^４１、上記式（ｂ３）中の連結基Ａ^５１または上記式（ｂ４）中の連結基Ａ^６１とに連結する１個以上の芳香族環である。Ｘ^３１は、好ましくは１個〜２個の芳香族環であり、より好ましくは１個の芳香族環である。
式（ｂ２）中、Ｒ^４７〜Ｒ^５０はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基である。Ｘ^４１は、パラ位またはメタ位で、連結基Ａ^４２と、連結基Ａ^４１、上記式（ａ１）中の連結基Ａ^１１、上記式（ａ２）中の連結基Ａ^２１、上記式（ｂ１）中の連結基Ａ^３１、上記式（ｂ３）中の連結基Ａ^５１または上記式（ｂ４）中の連結基Ａ^６１とに連結する１個以上の芳香族環である。Ｘ^４１は、好ましくは１個〜２個の芳香族環であり、より好ましくは１個の芳香族環である。
式（ｂ３）中、Ｒ^５７〜Ｒ^５９はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基である。Ｘ^５１は、パラ位またはメタ位で、連結基Ａ^５２と、連結基Ａ^５１、上記式（ａ１）中の連結基Ａ^１１、上記式（ａ２）中の連結基Ａ^２１、上記式（ｂ１）中の連結基Ａ^３１、上記式（ｂ２）中の連結基Ａ^４１または上記式（ｂ４）中の連結基Ａ^６１とに連結する１個以上の芳香族環である。Ｘ^５１は、好ましくは１個〜２個の芳香族環であり、より好ましくは１個の芳香族環である。
式（ｂ４）中、Ｒ^６７およびＲ^６８はそれぞれ独立して、水素原子または炭素数が１〜５の直鎖状もしくは分岐状のアルキル基であり、好ましくは水素原子またはメチル基であり、より好ましくはメチル基である。Ｒ^６９およびＲ^７０はそれぞれ独立して、水素原子、炭素数が１〜５の直鎖状もしくは分岐状のアルキル基、ハロゲン原子、メチルエチニル基、フェニルエチニル基、エチルエチニル基またはアルコキシ基であり、好ましくは水素原子である。Ｘ^６１は、パラ位またはメタ位で、連結基Ａ^６２と、連結基Ａ^６１、上記式（ａ１）中の連結基Ａ^１１、上記式（ａ２）中の連結基Ａ^２１、上記式（ｂ１）中の連結基Ａ^３１、上記式（ｂ２）中の連結基Ａ^４１または上記式（ｂ３）中の連結基Ａ^５１とに連結する１個以上の芳香族環である。Ｘ^６１は、好ましくは１個〜２個の芳香族環であり、より好ましくは１個の芳香族環である。 Preferably, the aromatic resin further has at least one repeating unit selected from repeating units represented by the following general formulas (b1) to (b4). If the aromatic resin has such a repeating unit, the heat resistance of the optical film can be improved. Since the repeating units represented by the following general formulas (b1) to (b4) have a rigid structure, it is considered that the heat resistance of the optical film can be improved by having the repeating units. In the present specification, the repeating units represented by the general formulas (b1) to (b4) are also referred to as repeating units (b1) to (b4), respectively. The repeating units represented by the general formulas (b1) to (b4) are also collectively referred to as “repeating unit (B)”.

In formulas (b1) to (b4), R ^{33 to} R ³⁶ , R ^{43 to} R ⁴⁶ , R ^{53 to} R ⁵⁶ and R ^{63 to} R ⁶⁶ are each independently a hydrogen atom or a carbon number of 1 to 5 It is a linear or branched alkyl group, more preferably a hydrogen atom, a methyl group or a t-butyl group. A ³¹ , A ³² , A ⁴¹ , A ⁴² , A ⁵¹ , A ⁵² , A ⁶¹ and A ⁶² are each independently at least one selected from the linking groups represented by the general formulas (1) to (5). Preferably, it is at least one selected from linking groups represented by the above general formulas (1) to (3), more preferably a linking group represented by the above general formula (1).
In the formula (b1), X ³¹ is a para-position or a meta-position, and the linking group A ³² , the linking group A ³¹ , the linking group A ¹¹ in the formula (a1), or the linking group A in the formula (a2). ^{21 is} one or more aromatic rings linked to the linking group A ^{41 in} the formula (b2), the linking group A ⁵¹ in the formula (b3) or the linking group A ⁶¹ in the formula (b4). . X ³¹ is preferably 1 to 2 aromatic rings, and more preferably 1 aromatic ring.
In formula (b2), R ^{47 to} R ⁵⁰ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms. X ⁴¹ is a para-position or a meta-position, the linking group A ⁴² , the linking group A ⁴¹ , the linking group A ^{11 in} the above formula (a1), the linking group A ²¹ in the above formula (a2), the above formula (b1). ) linking group ^{a 31} in a one or more aromatic rings coupled to the linking group ^{a 61} in the above formula (b3) connecting group ^{a 51} or the formula in (b4). X ⁴¹ is preferably 1 to 2 aromatic rings, and more preferably 1 aromatic ring.
In the formula (b3), R ^{57 to} R ⁵⁹ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms. X ⁵¹ is a para-position or a meta-position, the linking group A ⁵² , the linking group A ⁵¹ , the linking group A ^{11 in} the formula (a1), the linking group A ²¹ in the formula (a2), the formula (b1) ) linking group ^{a 31} in a one or more aromatic rings coupled to the linking group ^{a 61} in the above formula (b2) connecting group ^{a 41} or the formula in (b4). X ⁵¹ is preferably 1 to 2 aromatic rings, and more preferably 1 aromatic ring.
In formula (b4), R ⁶⁷ and R ⁶⁸ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or a methyl group, A methyl group is preferred. R ⁶⁹ and R ⁷⁰ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, a halogen atom, a methylethynyl group, a phenylethynyl group, an ethylethynyl group, or an alkoxy group. , Preferably a hydrogen atom. X ⁶¹ is a para-position or a meta-position, the linking group A ⁶² , the linking group A ⁶¹ , the linking group A ^{11 in} the above formula (a1), the linking group A ²¹ in the above formula (a2), the above formula (b1). ) linking group ^{a 31} in a above formula (b2) 1 or more aromatic rings coupled to the linking group ^{a 51} of the linking group ^{a 41} or the formula (b3) in in. X ⁶¹ is preferably 1 to 2 aromatic rings, and more preferably 1 aromatic ring.

  The content of the repeating unit (B) is preferably 0 mol% to 90 mol%, more preferably 10 mol% to 80 mol%, based on the total number of moles of the repeating units constituting the aromatic resin. And particularly preferably 20 to 80 mol%, most preferably 25 to 75 mol%. Within such a range, an optical film having excellent heat resistance and a small retardation can be obtained.

  As X in the formulas (a1), (a2) and (b1) to (b4), the total of the repeating unit (A) and the repeating unit (B) having an aromatic ring linked to the linking group at the para position, and meta The molar ratio (para position: meta position) of the repeating unit (A) having an aromatic ring connected to the connecting group at the position and the sum of the repeating units (B) is preferably 90:10 to 10:90, More preferably, it is 70: 30-30: 70, Most preferably, it is 60: 40-40: 60, Most preferably, it is 60: 40-50: 50. Within such a range, an optical film having excellent heat resistance and a small retardation can be obtained.

  The weight average molecular weight of the aromatic resin is preferably 40,000 to 200,000, more preferably 45,000 to 180,000 in terms of polystyrene. Within such a range, an optical film having a small retardation and excellent mechanical strength and solvent resistance can be obtained. In addition, the weight average molecular weight in this specification can be calculated | required by a gel permeation chromatography (GPC) measurement (solvent tetrahydrofuran).

  The glass transition temperature of the aromatic resin is preferably 200 ° C. or higher, more preferably 230 ° C. or higher, particularly preferably 240 ° C. or higher, and most preferably 250 ° C. The upper limit of the glass transition temperature of the aromatic resin is not particularly limited, but is usually about 300 ° C. An optical film containing an aromatic resin in such a range is excellent in heat resistance.

  The aromatic resin is preferably soluble in a solvent containing 50% or more of toluene and / or xylene, more preferably soluble in a solvent containing 70% or more of toluene and / or xylene, particularly preferably. Is soluble in a solvent containing 80% or more of toluene and / or xylene. If the aromatic resin is soluble in such a solvent, a coating process can be easily performed when an optical film is obtained by coating a solution containing the aromatic resin on a substrate. .

式（ａ１’）および（ａ２’）中、Ｚ^１１、Ｚ^１２、Ｚ^２１、Ｚ^２２、Ｒ^１１〜Ｒ^１６およびＲ^２１〜Ｒ^２６は、上記で説明したとおりである。Ｂ^１１、Ｂ^１２、Ｂ^２１およびＢ^２２はそれぞれ独立して、水酸基、ヒドロキシエチル基、ヒドロキシメチル基またはヒドロキシプロピル基である。 A-2. Polymerization of Aromatic Resin The aromatic resin having the repeating unit (A) includes, for example, a monomer represented by the following general formula (a1 ′) and / or (a2 ′), and an aromatic that can be polymerized with the monomer. It can be obtained by polymerizing a monomer composition containing a group monomer with any appropriate polymerization method. In the present specification, monomers represented by the following general formulas (a1 ′) and (a2 ′) are collectively referred to as “monomer (A ′)”.

In formulas (a1 ′) and (a2 ′), Z ¹¹ , Z ¹² , Z ²¹ , Z ²² , R ^{11 to} R ¹⁶ and R ^{21 to} R ²⁶ are as described above. B ¹¹ , B ¹² , B ²¹ and B ²² are each independently a hydroxyl group, a hydroxyethyl group, a hydroxymethyl group or a hydroxypropyl group.

  Examples of the monomer (A ′) include 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, and 2,2-bis. (2-hydroxy-5-biphenylyl) propane and the like. These monomers can be used alone or in admixture of two or more.

The aromatic monomer polymerizable with the monomer (A ′) may have only one aromatic ring or may have two or more aromatic rings. Good. The aromatic monomer preferably has 1 to 2 aromatic rings. The aromatic monomer polymerizable with the monomer (A ′) has two substituents polymerizable with the monomer (A ′) at the para-position or meta-position of the aromatic ring. As this substituent, the substituent represented by the following general formula (6), (7) or (8) is mentioned, for example. Examples of such aromatic monomers include terephthalic acid chloride, isophthalic acid chloride, 1,4-phenylene diisocyanate, 1,3-phenylene diisocyanate, dichlorodiphenyl sulfone, dichlorobenzene, 1,4-dihydroxynaphthalene, and the like. Is mentioned. The content ratio of the aromatic monomer having a substituent at the para position and the aromatic monomer having a substituent at the meta position is set to any appropriate content ratio depending on the desired structure of the aromatic resin. be able to. The molar ratio of the aromatic monomer having a substituent at the para position and the aromatic monomer having a substituent at the meta position (para position: meta position) is preferably 90:10 to 10:90, more preferably. Is 70:30 to 30:70, particularly preferably 60:40 to 40:60, and most preferably 60:40 to 50:50. In addition, the aromatic monomer may have any appropriate substituent in addition to the two substituents polymerizable with the monomer (A ′).

式（ｂ１’）〜（ｂ４’）中、Ｒ^３３〜Ｒ^３６、Ｒ^４３〜Ｒ^５０、Ｒ^５３〜Ｒ^５９およびＲ^６３〜Ｒ^７０は、上記で説明したとおりである。Ｂ^３１、Ｂ^３２、Ｂ^４１、Ｂ^４２、Ｂ^５１、Ｂ^５２、Ｂ^６１およびＢ^６２はそれぞれ独立して、水酸基、ヒドロキシエチル基、ヒドロキシメチル基またはヒドロキシプロピル基である。 When the aromatic resin further has a repeating unit (B), the aromatic resin includes the monomer (A ′), the aromatic monomer, and the following general formulas (b1 ′) to (b4 ′). A monomer composition containing at least one monomer selected from the monomers represented by formula (1) can be obtained by polymerizing by any appropriate polymerization method. In the present specification, monomers represented by the following general formulas (b1 ′) to (b4 ′) are collectively referred to as “monomer (B ′)”.

In formulas (b1 ′) to (b4 ′), R ^{33 to} R ³⁶ , R ^{43 to} R ⁵⁰ , R ^{53 to} R ⁵⁹ and R ^{63 to} R ⁷⁰ are as described above. B ³¹ , B ³² , B ⁴¹ , B ⁴² , B ⁵¹ , B ⁵² , B ⁶¹ and B ⁶² are each independently a hydroxyl group, a hydroxyethyl group, a hydroxymethyl group or a hydroxypropyl group.

  Examples of the monomer (B ′) include 9,9-bis (1-hydroxy-3-methylphenyl) fluorene, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 4, Examples thereof include 4 ′-(1-phenylethylidene) bisphenol and 4,4′-dihydroxytetraphenylmethane. These monomers can be used alone or in admixture of two or more.

  The monomer composition can include any suitable polymerization solvent. Examples of the polymerization solvent include halogen solvents such as chloroform, methylene chloride, and trichloroethane; aromatic hydrocarbon solvents such as toluene and xylene; and the like. Of these, toluene is preferred. If it is toluene, an aromatic resin can be obtained at low cost.

A-3. Formation of Optical Film The optical film of the present invention can be obtained, for example, by applying a casting solution obtained by dissolving the aromatic resin in any appropriate coating solvent onto a substrate.

  Examples of the coating solvent include ketone solvents, halogen solvents, aromatic solvents, highly polar solvents, and mixtures thereof. Examples of the ketone solvent include methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone. Examples of the halogen solvent include methylene chloride, ethylene chloride, chloroform, carbon tetrachloride, trichloroethane, and the like. Examples of the aromatic solvent include toluene, xylene, benzene, phenol and the like. Examples of the highly polar solvent include dimethyl sulfoxide, N-methylpyrrolidone, dimethylformamide, ethyl acetoacetate and the like.

  Any appropriate method can be used as the casting solution coating method, such as air doctor coating, blade coating, knife coating, reverse coating, transfer roll coating, gravure roll coating, kiss coating, cast coating, Coating methods such as spray coating, slot orifice coating, calendar coating, electrodeposition coating, dip coating, and die coating; relief printing methods such as flexographic printing, intaglio printing methods such as direct gravure printing methods, offset gravure printing methods, and offset printing methods Printing methods such as lithographic printing methods such as stencil printing methods such as screen printing methods. Any appropriate drying method (for example, natural drying, air drying, heat drying) can be adopted as a method for drying the coating layer formed by applying the casting solution. For example, in the case of heat drying, the drying temperature is typically 100 ° C. to 200 ° C., and the drying time is typically 1 minute to 30 minutes.

A-4. Optical Film The thickness of the optical film of the present invention is preferably 1 μm to 60 μm, more preferably 1 μm to 40 μm.

  The in-plane retardation Re of the optical film of the present invention is preferably 20 nm or less, more preferably 10 nm or less, still more preferably 5 nm or less, particularly preferably 1 nm or less, and most preferably 0.5 nm. It is as follows. When the optical film of the present invention contains the aromatic resin, an optical film having a small retardation can be obtained. In the present specification, the in-plane retardation Re means an in-plane retardation value of the optical film at 23 ° C. and a wavelength of 550 nm. Re represents the refractive index in the direction in which the in-plane refractive index is maximum (that is, the slow axis direction) as nx, and the refractive index in the direction orthogonal to the slow axis in the plane (that is, the fast axis direction). When it is set to ny and the thickness of the optical film is set to d (nm), it is calculated by Re = (nx−ny) × d.

  The thickness direction retardation Rth of the optical film of the present invention is preferably 100 nm or less, more preferably 80 nm or less, still more preferably 65 nm or less, particularly preferably 40 nm or less, and most preferably 0 nm to 30 nm or less. When the optical film of the present invention contains the aromatic resin, an optical film having a small retardation can be obtained. In this specification, the thickness direction retardation Rth refers to a retardation value in the thickness direction of the optical film at 23 ° C. and a wavelength of 550 nm. Rth is the refractive index in the direction in which the in-plane refractive index is maximum (that is, the slow axis direction) is nx, the refractive index in the thickness direction is nz, and the thickness of the optical film is d (nm). Rth = (nx−nz) × d.

  The birefringence Δn (nx−ny) in the in-plane direction of the optical film of the present invention is preferably 0.00074 or less, more preferably 0.00037 or less, still more preferably 0.00018 or less, Particularly preferred is 0.000036 or less, and most preferred is 0.000018 or less. In the present specification, the birefringence Δn (nx−ny) in the in-plane direction refers to the birefringence in the in-plane direction of the optical film at 23 ° C. and a wavelength of 550 nm. The birefringence Δn (nx−ny) in the in-plane direction is a direction orthogonal to the slow axis in the plane, where nx is the refractive index in the direction in which the in-plane refractive index is maximum (that is, the slow axis direction). When the refractive index in the fast axis direction (that is, the fast axis direction) is ny, Δn (nx−ny) = nx−ny.

  The birefringence Δn (nx−nz) in the thickness direction of the optical film of the present invention is preferably 0.0037 or less, more preferably 0.00296 or less, further preferably 0.00241 or less, particularly Preferably it is 0.00148 or less, Most preferably, it is 0.00-0.0011. In this specification, the birefringence index Δn (nx−nz) in the thickness direction refers to the birefringence index in the thickness direction of the optical film at 23 ° C. and a wavelength of 550 nm. The birefringence index Δn (nx−nz) in the thickness direction is defined as nx as the refractive index in the direction in which the in-plane refractive index is maximum (that is, the slow axis direction), and nz as the refractive index in the thickness direction. Δn (nx−nz) = nx−nz.

  The total light transmittance of the optical film of the present invention is preferably 85% or more, more preferably 87%, and most preferably 88% or more.

  The elastic modulus at 25 ° C. of the optical film of the present invention is preferably 1.5 GPa to 10 GPa, more preferably 1.6 GPa to 9 GPa, and particularly preferably 1.7 GPa to 8 GPa.

Fracture toughness value at 25 ° C. of the optical film of the present invention is preferably a ^{1.5MPa · m 1/2 ~10MPa · m 1/2} , more preferably ^{2MPa · m 1/2 ~8MPa} · m 1/2 and particularly preferably from ^{2.5MPa · m 1/2 ~6MPa · m 1/2} .

  The optical film of the present invention may further contain any appropriate additive depending on the purpose. Examples of the additives include diluents, anti-aging agents, denaturing agents, surfactants, dyes, pigments, anti-discoloring agents, ultraviolet absorbers, softeners, stabilizers, plasticizers, antifoaming agents, reinforcing agents, and the like. Is mentioned. The kind, number, and amount of additives contained in the resin composition can be appropriately set depending on the purpose.

B. Transparent substrate
B-1. Overall configuration diagram 1 of the transparent substrate is a schematic cross-sectional view of a transparent substrate according to a preferred embodiment of the present invention. The transparent substrate 100 includes an inorganic glass 10 and the optical films 11 and 11 ′ disposed on one side or both sides of the inorganic glass 10 (preferably, both sides as in the illustrated example). As the optical films 11 and 11 ′, the optical film described in the above section A is used. In addition, although not shown in figure, arbitrary appropriate adhesive bond layers may be arrange | positioned between the inorganic glass 10 and the 1st optical films 11 and 11 '.

  The transparent substrate may be provided with any appropriate other layer as an outermost layer as necessary. Examples of the other layers include a hard coat layer and a transparent conductive layer.

  The total thickness of the transparent substrate is preferably 150 μm or less, more preferably 120 μm or less, and particularly preferably 50 μm to 120 μm. By providing the optical film, the transparent substrate can make the thickness of the inorganic glass much thinner than a conventional glass substrate.

  The fracture diameter when the transparent substrate is cracked and bent is preferably 50 mm or less, more preferably 40 mm or less, and particularly preferably 25 mm or less. The transparent substrate of the present invention exhibits excellent flexibility (for example, a fracture diameter in the above range) by including the optical film.

  The total light transmittance of the transparent substrate is preferably 80% or more, and more preferably 85% or more. Preferably, the transparent substrate has a reduction rate of light transmittance of 5% or less after heat treatment at 180 ° C. for 2 hours. This is because with such a reduction rate, a practically acceptable light transmittance can be ensured even if the heat treatment necessary in the FPD manufacturing process is performed.

  The surface roughness Ra of the transparent substrate is preferably 50 nm or less, more preferably 30 nm or less, and particularly preferably 10 nm or less. The waviness of the transparent substrate is preferably 0.5 μm or less, and more preferably 0.1 μm or less. A transparent substrate having such characteristics is excellent in quality.

  When the optical film is disposed on both sides of the inorganic glass, the thickness of each optical film may be the same or different. Preferably, the thickness of each optical film is the same. Furthermore, each optical film may be comprised with the resin compound of the same composition, and may be comprised with the resin compound of a different composition. Preferably, each optical film is composed of a resin compound having the same composition. Therefore, most preferably, each optical film is comprised so that it may become the same thickness with the resin compound of the same composition. With such a configuration, even when heat treatment is performed, thermal stress is evenly applied to both surfaces of the inorganic glass, and thus warpage and undulation are extremely unlikely to occur.

B-2. Inorganic glass As long as the inorganic glass used for the transparent substrate of this invention is a plate-shaped thing, arbitrary appropriate things may be employ | adopted. Examples of the inorganic glass include soda-lime glass, borate glass, aluminosilicate glass, and quartz glass according to the classification according to the composition. Moreover, according to the classification | category by an alkali component, an alkali free glass and a low alkali glass are mentioned. The content of alkali metal components (for example, Na ₂ O, K ₂ O, Li ₂ O) in the inorganic glass is preferably 15% by weight or less, and more preferably 10% by weight or less.

  The thickness of the inorganic glass is preferably 100 μm or less, more preferably 20 μm to 80 μm, and particularly preferably 30 μm to 70 μm. In this invention, the thickness of inorganic glass can be made thin by having an optical film in the one side or both sides of inorganic glass.

The light transmittance of the inorganic glass at a wavelength of 550 nm is preferably 85% or more. The refractive index _ng of the inorganic glass at a wavelength of 550 nm is preferably 1.4 to 1.65.

The density of the inorganic glass is preferably ^{2.3g / cm 3 ~3.0g / cm 3} , more preferably from ^{2.3g / cm 3 ~2.7g / cm 3} . If it is the inorganic glass of the said range, a lightweight transparent substrate will be obtained.

  Arbitrary appropriate methods may be employ | adopted for the shaping | molding method of the said inorganic glass. Typically, the inorganic glass is a mixture of a main raw material such as silica or alumina, an antifoaming agent such as sodium nitrate or antimony oxide, and a reducing agent such as carbon at a temperature of 1400 ° C to 1600 ° C. Then, after forming into a thin plate shape, it is produced by cooling. Examples of the method for forming the inorganic glass sheet include a slot down draw method, a fusion method, and a float method. The inorganic glass formed into a plate shape by these methods may be chemically polished with a solvent such as hydrofluoric acid, if necessary, in order to reduce the thickness or improve the smoothness.

  As the inorganic glass, a commercially available one may be used as it is, or a commercially available inorganic glass may be polished to have a desired thickness. Examples of commercially available inorganic glasses include “7059”, “1737” or “EAGLE 2000” manufactured by Corning, “AN100” manufactured by Asahi Glass, “NA-35” manufactured by NH Techno Glass, and “OA-” manufactured by Nippon Electric Glass. 10 ”,“ D263 ”or“ AF45 ”manufactured by Schott Corporation.

B-3. Other layer The said transparent substrate can be equipped with arbitrary appropriate other layers as an outermost layer as needed. Examples of the other layers include a transparent conductive layer and a hard coat layer.

  The transparent conductive layer can function as an electrode or an electromagnetic wave shield.

  Examples of materials that can be used for the transparent conductive layer include metals such as copper and silver; metal oxides such as indium tin oxide (ITO) and indium zinc oxide (IZO); and conductive materials such as polythiophene and polyaniline. Examples of the polymer include a composition containing carbon nanotubes.

  The hard coat layer has a function of imparting chemical resistance, scratch resistance and surface smoothness to the transparent substrate.

  Any appropriate material can be adopted as the material constituting the hard coat layer. Examples of the material constituting the hard coat layer include an epoxy resin, an acrylic resin, a silicone resin, and a mixture thereof. Among these, an epoxy resin excellent in heat resistance is preferable. The hard coat layer can be obtained by curing these resins with heat or active energy rays.

B-4. Manufacturing method of a transparent substrate In one embodiment, the said transparent substrate can be obtained by forming an optical film on inorganic glass by solution coating. Specifically, as described in the section A, the transparent substrate is formed by using the inorganic glass as the base material when the optical film is formed by applying a casting solution containing an aromatic resin to the base material. Can be obtained.

  In another embodiment, after forming an optical film as described in the above section A, the optical film can be adhered to the inorganic glass through an adhesive layer to obtain a transparent substrate. .

  Arbitrary appropriate resin can be employ | adopted as a material which comprises the said adhesive bond layer. Examples of the material constituting the adhesive layer include thermosetting resins and active energy ray curable resins. Specific examples of such resins include epoxy resins containing epoxies and / or oxetanes; acrylic resins; silicone resins. An epoxy resin excellent in heat resistance is preferable. In addition, you may use these resin individually or in combination of 2 or more types. Any appropriate epoxy can be used as long as it has an epoxy group in the molecule. Examples of the epoxies include bisphenol types such as bisphenol A type, bisphenol F type, bisphenol S type and their water additives; novolak types such as phenol novolak type and cresol novolak type; triglycidyl isocyanurate type and hydantoin type. Nitrogen-containing ring type such as alicyclic type; aliphatic type; aromatic type such as naphthalene type and biphenyl type; glycidyl type such as glycidyl ether type, glycidyl amine type and glycidyl ester type; dicyclo such as dicyclopentadiene type Type; ester type; ether ester type; and modified types thereof. These epoxies can be used alone or in admixture of two or more. Preferably, the epoxy is a bisphenol A type, an alicyclic type, a nitrogen-containing ring type, or a glycidyl type. Examples of the oxetanes include 3-ethyl-3-hydroxymethyloxetane (oxetane alcohol), 2-ethylhexyl oxetane, xylylene bisoxetane, 3-ethyl-3 ((((3-ethyloxetane-3-yl And methoxy) methyl) oxetane.

  The thickness of the adhesive layer is preferably 10 μm or less, more preferably 0.01 μm to 10 μm, and particularly preferably 0.1 μm to 7 μm. If the thickness of the said adhesive bond layer is such a range, the outstanding adhesiveness of the said inorganic glass and an optical film is realizable, without impairing the flexibility of a transparent substrate.

C. Applications The optical film and the transparent substrate can be used for any appropriate display element, solar cell, or lighting element. Examples of the display element include a liquid crystal display, a plasma display, an organic EL display, and electronic paper. Examples of illumination elements include organic EL elements and LED elements.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all. The evaluation methods in the examples are as follows. The thickness was measured using an Anritsu digital micrometer “KC-351C type”.

(1) Glass transition temperature (Tg)
Using a dynamic viscoelasticity spectrum analyzer (DMA, manufactured by TA Instruments Inc.), measurement is performed at a frequency of 10 Hz and a heating rate of 5 ° C./min in the range of 30 ° C. to 310 ° C., and the peak top of tan θ is glass. The transition temperature was used.
(2) Retardation value The in-plane retardation of the optical film and the retardation in the thickness direction were measured using a polarimeter AxoScan manufactured by Axometrics. The measurement wavelength was 550 nm and the measurement temperature was 23 ° C.
(3) Birefringence index The birefringence index Δn (nx−ny) in the in-plane direction and the birefringence index Δn (nx−nz) in the thickness direction of the optical film were measured using a polarimeter AxoScan manufactured by Axometrics. The measurement wavelength was 550 nm and the measurement temperature was 23 ° C.
(4) Transmittance The transmittance of the optical film was evaluated from the Y value obtained by correcting the visibility with a 2-degree visual field (C light source) of JlS Z 8701-1982. In Table 1, the case where the transmittance is 85% or more is expressed as “◯”.

[Synthesis Example 1]
In a reaction vessel equipped with a stirrer, 1,5-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane 9.05 g (0.021 mol), 9,9-bis (1-hydroxy-3-methylphenyl) fluorene 15 0.4 g (0.041 mol), benzyltributylammonium chloride 0.542 g, and p-tertiary butylphenol 0.023 g were dissolved in 1M sodium hydroxide solution 226 g. To this solution, a solution prepared by dissolving 6.25 g (0.031 mol) of terephthalic acid chloride and 6.25 g (0.031 mol) of isophthalic acid chloride in 168 g of toluene was added all at once with stirring, and the mixture was stirred at room temperature for 120 minutes. . Thereafter, the polymerization solution was allowed to stand to separate the toluene solution containing the polymer, then washed with acetic acid water, washed with ion-exchanged water, and then poured into methanol to precipitate the polymer. The precipitated polymer was filtered and dried under reduced pressure to obtain 30 g of a white aromatic resin (1). The obtained aromatic resin (1) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 2]
An aromatic resin (2) was obtained in the same manner as in Synthesis Example 1 except that the amount of p-tertiary butylphenol was 0.013 g and the amount of toluene was 150 g. The obtained aromatic resin (2) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 3]
In a reaction vessel equipped with a stirrer, 8.24 g (0.021 mol) of 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 9,9-bis (1-hydroxy-3-methylphenyl) fluorene 15 0.4 g (0.041 mol), benzyltributylammonium chloride 0.525 g, and p-tertiary butylphenol 0.022 g were dissolved in 219 g of 1M sodium hydroxide solution. To this solution, a solution prepared by dissolving 6.24 g (0.031 mol) of terephthalic acid chloride and 6.24 g (0.031 mol) of isophthalic acid chloride in 168 g of toluene was added all at once with stirring, and the mixture was stirred at room temperature for 120 minutes. . Thereafter, the polymerization solution was allowed to stand to separate the toluene solution containing the polymer, then washed with acetic acid water, washed with ion-exchanged water, and then poured into methanol to precipitate the polymer. The precipitated polymer was filtered and dried under reduced pressure to obtain 29 g of a white aromatic resin (3). The obtained aromatic resin (3) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 4]
An aromatic resin (4) was obtained in the same manner as in Synthesis Example 3 except that the amount of p-tertiary butylphenol was 0.016 g and the amount of toluene was 150 g. The obtained aromatic resin (4) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 5]
Aromatic resin (5) in the same manner as in Synthesis Example 1, except that the amount of terephthalic acid chloride was 7.01 g (0.035 mol) and the amount of isophthalic acid chloride was 5.50 g (0.027 mol). Got. The obtained aromatic resin (5) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 6]
1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane 9.02 g (0.021 mol), 9,9-bis (1-hydroxy-3-methylphenyl) fluorene 16.3 g (0.043 mol) and 1 , 4-Dihydroxynaphthalene 11.37 g (0.071 mol) partially dissolved / partially dispersed in 100 ml of 2N aqueous potassium hydroxide solution, 200 ml of solvent methylene chloride was added and stirred while cooling. 10.58 g (0.107 mol) of phosgene gas was blown into this liquid. Subsequently, this reaction liquid was left and separated to obtain a methylene chloride solution of an oligomer having a degree of polymerization of 2 to 5 in the organic layer and having a chloroformate group at the molecular end. Then, methylene chloride was added to 200 ml of the obtained methylene chloride solution to make the total amount 300 ml, and then 3.02 g (0.007 mol) of 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane was added to 2 ml. A solution dissolved in 50 ml of normal potassium hydroxide was added, and 0.05 g of p-tert-butylphenol was further added as a molecular weight regulator. Next, while vigorously stirring the mixed solution, 0.8 ml of a 7% aqueous triethylamine solution was added as a catalyst, and the mixture was reacted at 25 ° C. for 1.5 hours with stirring. After completion of the reaction, the obtained reaction product was diluted with 1 L of methylene chloride and washed twice with 1.5 L of water. Then, after washing with 0.05 N hydrochloric acid, it was further washed twice with 1 L of water. The obtained organic phase was put into methanol and re-precipitated to obtain 28 g of powdered aromatic resin (6). The obtained aromatic resin (6) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 7]
1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane 5.62 g (0.013 mol), 9,9-bis (1-hydroxy-3-methylphenyl) fluorene 8.33 g (0.022 mol), 1 , 4-phenylene diisocyanate (11.37 g, 0.071 mol) dissolved in 100 ml of dimethylformamide was heated and stirred at 120 ° C. in an N 2 atmosphere to obtain a prepolymer. Subsequently, 6.48 g (0.015 mol) of 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane and 7.95 g of 9,9-bis (1-hydroxy-3-methylphenyl) fluorene were added to this reaction solution. (0.021 mol) of a dimethylformamide solution was added, and 1.1 g of a 1% dibutyltin dilaurate solution was further added as a reaction catalyst, followed by heating and stirring at 120 ° C. After completion of the reaction, the obtained reaction solution was put into methanol and re-precipitated to obtain 23 g of powdered aromatic resin (7). The obtained aromatic resin (7) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 8]
In a reaction vessel equipped with a stirrer, 5.35 g (0.018 mol) of 4,4 ′-(1-phenylethylidene) bisphenol, 9.3 g of 9,9-bis (1-hydroxy-3-methylphenyl) fluorene (0 0.025 mol), 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane 5.71 g (0.018 mol) benzyltributylammonium chloride 0.452 g, p-tertiary butylphenol 0.067 g 1M It was dissolved in 189 g of sodium hydroxide solution. To this solution, a solution prepared by dissolving 7.48 g (0.037 mol) of terephthalic acid chloride and 5.0 g (0.025 mol) of isophthalic acid chloride in 187 g of toluene was added all at once with stirring, and stirred at room temperature for 120 minutes. . Thereafter, the polymerization solution was allowed to stand to separate the toluene solution containing the polymer, then washed with acetic acid water, washed with ion-exchanged water, and then poured into methanol to precipitate the polymer. The precipitated polymer was filtered and dried under reduced pressure to obtain 11 g of a white aromatic resin (c1). The obtained aromatic resin (c1) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 9]
In a reaction vessel equipped with a stirrer, 7.05 g (0.019 mol) of 9,9-bis (1-hydroxy-3-methylphenyl) fluorene, 1,1-bis (4-hydroxyphenyl) -3,3,5 -13.5 g (0.043 mol) of trimethylcyclohexane, 0.456 g of benzyltributylammonium chloride and 0.068 g of p-tertiary butylphenol were dissolved in 190 g of 1M sodium hydroxide solution. To this solution, a solution prepared by dissolving 6.3 g (0.031 mol) of terephthalic acid chloride and 6.3 g (0.031 mol) of isophthalic acid chloride in 283 g of toluene was added at a time while stirring, and the solution was stirred at room temperature for 120 minutes. . Thereafter, the polymerization solution was allowed to stand to separate the toluene solution containing the polymer, then washed with acetic acid water, washed with ion-exchanged water, and then poured into methanol to precipitate the polymer. The precipitated polymer was filtered and dried under reduced pressure to obtain 28 g of a white aromatic resin (c2). The obtained aromatic resin (c2) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Synthesis Example 10]
In a reaction vessel equipped with a stirrer, 7.65 g (0.028 mol) of 4,4 ′-(1,3-dimethylbutylidene) bisphenol, 12.35 g of 0,4 ′-(1-phenylethylidene) bisphenol (0 0.043 mol), 0.444 g of benzyltriethylammonium chloride, and 0.022 g of p-tertiary butylphenol were dissolved in 185 g of 1M sodium hydroxide solution. To this solution, a solution of 14.4 g (0.071 mol) of terephthalic acid chloride dissolved in 246 g of chloroform was added all at once with stirring, and the mixture was stirred at room temperature for 120 minutes. Thereafter, the polymerization solution was allowed to stand to separate the chloroform solution containing the polymer, then washed with acetic acid water, washed with ion-exchanged water, and then poured into methanol to precipitate the polymer. The precipitated polymer was filtered and dried under reduced pressure to obtain 7 g of a white aromatic resin (c3). The obtained aromatic resin (c3) was subjected to the evaluation of (1) above. The results are shown in Table 1.

[Example 1]
Casting for optical film formation is performed by dissolving 10 g of the aromatic resin (1) obtained in Synthesis Example 1 in 90 g of cyclopentanone and further adding a leveling agent (BYK307, manufactured by BYK Chemie) to 750 ppm. A solution was obtained.
The obtained casting solution was coated on a glass plate, dried at 100 ° C. for 10 minutes, and heat-treated at 170 ° C. for 20 minutes to obtain an optical film having a thickness of 25 μm. This optical film was peeled from the glass plate and subjected to the evaluations (2) and (3). The results are shown in Table 1.

[Examples 2 to 7]
An optical film was obtained in the same manner as in Example 1 except that the aromatic resins (2) to (7) shown in Table 1 were used instead of the aromatic resin (1). We used for evaluation.

[Comparative Examples 1-3]
An optical film was obtained in the same manner as in Example 1 except that the aromatic resins (c1) to (c3) shown in Table 1 were used instead of the aromatic resin (1). We used for evaluation.

[Comparative Example 4]
As an optical film, a commercially available polyarylate film (trade name “M-2070” manufactured by Unitika Ltd.) was prepared. The polyarylate film was subjected to the same evaluation as in Example 1.

  As is clear from Table 1, the optical film of the present invention contains an aromatic resin having a high glass transition temperature, is excellent in heat resistance, and has a small phase difference. Since the optical film of the present invention is excellent in heat resistance and low phase difference and has a high transmittance as described above, it can be usefully used for a display element, a solar cell or a lighting element.

  The transparent substrate of the present invention can be used for a display element, a solar cell, or a lighting element. Examples of the display element include a liquid crystal display, a plasma display, an organic EL display, and electronic paper. Examples of illumination elements include organic EL elements and LED elements.

10 Inorganic glass 11, 11 ′ Optical film 100 Transparent substrate

Claims (14)

An optical film comprising an aromatic resin having at least one repeating unit selected from the repeating unit represented by the following general formula (a1) and the repeating unit represented by the following general formula (a2):

In formulas (a1) and (a2),
Z ¹¹ , Z ¹² , Z ²¹ and Z ²² are each independently a substituent containing a cycloalkane or an aromatic ring;
R ¹¹ , R ¹² , R ²¹ and R ²² are each independently a hydrogen atom, a cycloalkane, an aromatic ring or a linear or branched alkyl group having 1 to 5 carbon atoms,
R ^{13 to} R ¹⁶ and R ^{23 to} R ²⁶ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms,
A ¹¹ , A ¹² , A ²¹ and A ²² are each independently at least one selected from the linking groups represented by the general formulas (1) to (5),
X ¹¹ is one or more aromatic rings linked to the linking group A ¹² and the linking group A ¹¹ or A ²¹ at the para-position or the meta-position;
X ²¹ is one or more aromatic rings linked to the linking group A ²² and the linking group A ²¹ or A ¹¹ at the para or meta position. The optical film according to claim 1, wherein the aromatic resin further has at least one repeating unit selected from repeating units represented by the following general formulas (b1) to (b4):

In formulas (b1) to (b4),
R ^{33 to} R ³⁶ , R ^{43 to} R ⁴⁶ , R ^{53 to} R ⁵⁶ and R ^{63 to} R ⁶⁶ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms. Yes,
A ³¹ , A ³² , A ⁴¹ , A ⁴² , A ⁵¹ , A ⁵² , A ⁶¹ and A ⁶² are each independently at least one selected from the linking groups represented by the general formulas (1) to (5). And
In formula (b1),
X ³¹ is a para-position or a meta-position, the linking group A ³² , the linking group A ³¹ , A ^{11 in} the formula (a1), A ^{21 in} the formula (a2), and the formula (b2) A ⁴¹ , one or more aromatic rings linked to A ⁵¹ in the formula (b3) or A ⁶¹ in the formula (b4),
In formula (b2),
R ^{47 to} R ⁵⁰ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms,
X ⁴¹ is a para-position or a meta-position, and the linking group A ⁴² , the linking group A ⁴¹ , A ^{11 in} the formula (a1), A ^{21 in} the formula (a2), and the formula (b1) of ^{a 31,} a one or more aromatic rings coupled to the ^{a 61} in ^{a 51} or formula in the formula (b3) (b4),
In formula (b3),
R ^{57 to} R ⁵⁹ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms,
X ⁵¹ is a para-position or a meta-position, and the linking group A ⁵² , the linking group A ⁵¹ , A ^{11 in} the formula (a1), A ^{21 in} the formula (a2), and the formula (b1) of ^{a 31,} a one or more aromatic rings coupled to the ^{a 61} in ^{a 41} or formula in the formula (b2) (b4),
In formula (b4),
R ⁶⁷ and R ⁶⁸ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms.
R ⁶⁹ and R ⁷⁰ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, a halogen atom, a methylethynyl group, a phenylethynyl group, an ethylethynyl group, or an alkoxy group. ,
X ⁶¹ is a para-position or a meta-position, and the linking group A ⁶² , the linking group A ⁶¹ , A ^{11 in} the formula (a1), A ^{21 in} the formula (a2), and the formula (b1) of ^{a 31,} which is one or more aromatic rings coupled to the ^{a 51} in formula (b2) ^{a 41} or formula (b3) in.   The optical film according to claim 1, wherein the in-plane retardation Re is 20 nm or less.   The optical film according to claim 1, wherein the thickness direction retardation Rth is 100 nm or less.   The optical film in any one of Claim 1 to 4 whose total light transmittance is 85% or more.   The optical film according to claim 1, wherein the aromatic resin has a glass transition temperature of 200 ° C. or higher.   The optical film according to any one of claims 1 to 6, wherein a weight average molecular weight of the aromatic resin is 40,000 to 200,000 in terms of polystyrene.   The optical film according to any one of claims 1 to 7, wherein the aromatic resin is soluble in a solvent containing 50% or more of toluene and / or xylene.   A transparent substrate comprising the optical film according to claim 1 and an inorganic glass having a thickness of 100 μm or less.   The transparent substrate according to claim 9, wherein the total thickness is 150 μm or less.   The transparent substrate according to claim 9 or 10, wherein a fracture diameter when a crack is inserted and bent is 50 mm or less.   The display element produced using the optical film in any one of Claim 1 to 8.   The solar cell produced using the optical film in any one of Claim 1 to 8. An illumination element produced using the optical film according to claim 1.

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