JP6556317B1 - OPTICAL LAMINATE, FLEXIBLE DISPLAY DEVICE, AND OPTICAL LAMINATE MANUFACTURING METHOD - Google Patents

Abstract

An optical laminate for a flexible display device having excellent optical homogeneity is provided. An optical laminate including an optical film containing a polyimide resin and / or a polyamide resin and a functional layer laminated on at least one surface, and obtained by a projection method using the optical film or the optical laminate. In the film inverse aerial image obtained by Fourier transform of the projected image, Ymh, Ymv, and the maximum value of the difference between the line profile in the directions h and v orthogonal to each other and the line profile in the same direction of the background image are respectively given. An optical laminate in which Ymh and Ymv are both 40 or less when the frequencies are Xmh and Xmv, respectively. [Selection] Figure 3

Description

  The present invention relates to an optical laminate, a flexible display device including the optical laminate, and a method for manufacturing the optical laminate.

  An optical film used in an image display device such as a liquid crystal display device or an organic EL display device has a very high optical homogeneity because a user visually recognizes an image directly displayed through the optical film. Required.

  As a method for producing such an optical film, a method in which a solution containing a volatile solvent and a resin constituting the optical film is coated on a substrate, dried and then peeled off is used (for example, Patent Documents). 1). In such a production method involving coating and drying, thickness unevenness and alignment unevenness may occur depending on coating conditions and drying conditions. Even when the film has a level of unevenness that cannot be visually confirmed, when the film is finally incorporated as an optical film in an image display device, the optical homogeneity is impaired due to the unevenness, and the image In some cases, distortion or the like is visually recognized. Therefore, a film used as an optical film in an image display device is required to have optical homogeneity with a very high accuracy at a level that is difficult to visually confirm. Thus, there is still a need for further improvements in the optical homogeneity of the film.

  As an optical film in which unevenness of the film is suppressed, for example, in Patent Document 1, in a rectangular area cut out from a projected image of a polyimide optical film, a standard deviation σ of gray scale and a black portion in a binarized image of the rectangular area are disclosed. A polyimide-based optical film whose area is adjusted within a predetermined range is described. Patent Document 2 describes an optical transparent film in which the variation in luminance of transmitted light in the film plane is within 15% of the average luminance with a standard deviation. In Patent Document 3, light from a light source unit is irradiated onto a lattice plate, light transmitted through the lattice plate is projected as a lattice image, the lattice image is photographed, and the three-dimensional shape of the object to be measured is determined from the lattice image distortion. A shape measuring method by a fringe projection method for quantifying the system shape is described.

International Publication No. 2016/152459 JP-A-9-48866 JP 2011-226871 A

However, any of the methods described in the above patent documents is a method sufficient for evaluating the optical homogeneity of the film with very high accuracy required for an optical film used in an image display device. I can't say that. Since the method described in Patent Document 1 is an evaluation in an analysis area of 1 cm × 5 cm, it is not a method that can sufficiently evaluate a decrease in optical homogeneity due to unevenness that occurs in the vertical direction. The method described in Patent Document 2 is not a method that can accurately evaluate the decrease in optical homogeneity caused by thin unevenness of light and shade with small difference in luminance of transmitted light.
Since the method described in Patent Document 3 is a method for detecting a shape, it is not possible to evaluate a decrease in optical homogeneity due to uneven refractive index. Therefore, none of the films obtained by these methods can be said to have sufficient optical homogeneity.

  The present invention has been made in view of the above-described problems of the prior art, and is suitably used as an optical film in an image display device or the like, an optical laminate excellent in optical homogeneity, and a flexible including the optical laminate. It is an object of the present invention to provide a display device and a method for manufacturing the optical laminate.

を満たす、光学積層体。
〔２〕ポリイミド系樹脂及び／又はポリアミド系樹脂を含む光学フィルムと、該光学フィルムの少なくとも片面に積層された機能層とを有する光学積層体であって、
前記光学積層体を用いて投影法により得た投影画像をフーリエ変換して得たフィルム逆空間像において互いに直交する方向ｈ及び方向ｖにおけるラインプロファイルをそれぞれラインプロファイルｈ及びラインプロファイルｖとし、前記投影法において前記光学積層体を用いずに得た背景画像をフーリエ変換して得た背景逆空間像において互いに直交する方向ｈ’及び方向ｖ’におけるラインプロファイルをそれぞれラインプロファイルｈ’及びラインプロファイルｖ’とし、ラインプロファイルｈからラインプロファイルｈ’を引いて得たラインプロファイル（ｈ−ｈ’）の最大強度をＹ_ｍｈとし、最大強度Ｙ_ｍｈを示す周波数をＸ_ｍｈとし、ラインプロファイルｖからラインプロファイルｖ’を引いて得たラインプロファイル（ｖ−ｖ’）の最大強度をＹ_ｍｖとし、最大強度Ｙ_ｍｖを示す周波数をＸ_ｍｖとすると、Ｙ_ｍｈ及びＹ_ｍｖはいずれも４０以下であり、Ｙ_ｍｈ、Ｙ_ｍｖ、Ｘ_ｍｈ及びＸ_ｍｖは、次の関係：

を満たす、光学積層体。
〔３〕機能層の少なくとも１つは、ハードコート機能、帯電防止機能、防眩機能、低反射機能、反射防止機能及び防汚機能からなる群から選択される少なくとも１つの機能を備える層である、前記〔１〕又は〔２〕に記載の光学積層体。
〔４〕光学積層体の少なくとも一方の面の鉛筆硬度はＨ以上である、前記〔１〕〜〔３〕のいずれかに記載の光学積層体。
〔５〕光学積層体の少なくとも一方の面の表面抵抗率は１．０×１０^１３Ω／ｓｑ以下である、前記〔１〕〜〔４〕のいずれかに記載の光学積層体。
〔６〕光学積層体の黄色度は３．０以下である、前記〔１〕〜〔５〕のいずれかに記載の光学積層体。
〔７〕幅方向の長さが２０ｃｍ以上、長さ方向の長さが１ｍ以上である、前記〔１〕〜〔６〕のいずれかに記載の光学積層体。
〔８〕フレキシブル表示装置の前面板用のフィルムである、前記〔１〕〜〔７〕のいずれかに記載の光学積層体。
〔９〕前記〔１〕〜〔８〕のいずれかに記載の光学積層体を備えるフレキシブル表示装置。
〔１０〕タッチセンサをさらに備える、前記〔９〕に記載のフレキシブル表示装置。
〔１１〕偏光板をさらに備える、前記〔９〕又は〔１０〕に記載のフレキシブル表示装置。
〔１２〕前記〔１〕〜〔８〕のいずれかに記載の光学積層体の製造方法であって、
（ａ）ポリイミド系樹脂及び／又はポリアミド系樹脂、ならびに溶媒を少なくとも含有するワニスを支持体上に塗布し、乾燥させ、塗膜を形成させる工程、
（ｂ）支持体から塗膜を剥離する工程、
（ｃ）剥離した塗膜を加熱し、フィルムを得る工程、及び、
（ｄ）フィルムの少なくとも片面に機能層を積層し、光学積層体を得る工程
を少なくとも含む、製造方法。 In order to solve the above-mentioned problems, the present inventors can evaluate the optical homogeneity of an optical film or optical laminate with high accuracy, and the optical homogeneity and optical properties of the optical film or optical laminate. We have intensively studied how to improve the characteristics. As a result, it has been found that an optical laminate satisfying the following requirements has excellent optical homogeneity, and the present invention has been completed. That is, the present invention includes the following aspects.
[1] An optical laminate having an optical film containing a polyimide resin and / or a polyamide resin, and a functional layer laminated on at least one surface of the optical film,
Line projections in the direction h and the direction v orthogonal to each other in a film inverse space image obtained by Fourier transforming a projection image obtained by the projection method using the optical film are defined as a line profile h and a line profile v, respectively. The line profiles in the direction h ′ and the direction v ′ orthogonal to each other in the background inverse space image obtained by Fourier transforming the background image obtained without using the film in FIG. The maximum intensity of the line profile (h ′) obtained by subtracting the line profile h ′ from the profile h is Y _mh , the frequency indicating the maximum intensity Y _mh is X _mh, and the line profile v ′ is subtracted from the line profile v. Line profile (v-v ') The degrees and _{Y mv,} and the frequency showing the maximum intensity _{Y mv} and _{X mv, Y mh} and _{Y mv} is any even 40 or _{less, Y mh, Y mv, X} mh and _{X mv} is the following relationship:

An optical laminate satisfying the above requirements.
[2] An optical laminate having an optical film containing a polyimide resin and / or a polyamide resin, and a functional layer laminated on at least one surface of the optical film,
Line profiles in the direction h and the direction v orthogonal to each other in the film inverse aerial image obtained by Fourier transforming the projection image obtained by the projection method using the optical layered body are defined as the line profile h and the line profile v, respectively. In the background inverse aerial image obtained by Fourier transforming the background image obtained without using the optical laminate in the method, the line profiles in the direction h ′ and the direction v ′ orthogonal to each other are respectively represented as a line profile h ′ and a line profile v ′. Y _mh is the maximum intensity of the line profile (h ′) obtained by subtracting the line profile h ′ from the line profile h, X _mh is the frequency indicating the maximum intensity Y _mh , and the line profile v to the line profile v Maximum of line profile (v-v ') obtained by subtracting The degrees and _{Y mv,} and the frequency showing the maximum intensity _{Y mv} and _{X mv, Y mh} and _{Y mv} is any even 40 or _{less, Y mh, Y mv, X} mh and _{X mv} is the following relationship:

An optical laminate satisfying the above requirements.
[3] At least one of the functional layers is a layer having at least one function selected from the group consisting of a hard coat function, an antistatic function, an antiglare function, a low reflection function, an antireflection function, and an antifouling function. The optical laminate according to [1] or [2].
[4] The optical laminate according to any one of [1] to [3], wherein the pencil hardness of at least one surface of the optical laminate is H or more.
[5] The optical laminate according to any one of [1] to [4], wherein the surface resistivity of at least one surface of the optical laminate is 1.0 × 10 ¹³ Ω / sq or less.
[6] The optical laminate according to any one of [1] to [5], wherein the yellowness of the optical laminate is 3.0 or less.
[7] The optical laminate according to any one of [1] to [6], wherein the length in the width direction is 20 cm or more and the length in the length direction is 1 m or more.
[8] The optical laminate according to any one of [1] to [7], which is a film for a front plate of a flexible display device.
[9] A flexible display device comprising the optical laminate according to any one of [1] to [8].
[10] The flexible display device according to [9], further including a touch sensor.
[11] The flexible display device according to [9] or [10], further including a polarizing plate.
[12] The method for producing an optical laminate according to any one of [1] to [8],
(A) a step of applying a polyimide resin and / or a polyamide resin, and a varnish containing at least a solvent on a support and drying to form a coating film;
(B) a step of peeling the coating film from the support;
(C) heating the peeled coating film to obtain a film; and
(D) A production method including at least a step of laminating a functional layer on at least one surface of the film to obtain an optical laminate.

  ADVANTAGE OF THE INVENTION According to this invention, the optical laminated body excellent in optical homogeneity, a flexible display apparatus provided with this optical laminated body, and the manufacturing method of this optical laminated body can be provided.

It is the schematic which shows the example of arrangement | positioning in the process of obtaining a projection image. It is the schematic for demonstrating arrangement | positioning in the process of obtaining the projection image in an Example and a comparative example. _Y max in the line profile _is a diagram for explaining the _{X max} and _{X cen.} It is a figure which shows the line profile before normalization obtained from the projection image of Example 1. FIG. It is a figure which shows the line profile after normalization obtained from the projection image of Example 1. FIG. It is a figure which shows the line profile after the normalization obtained from the background image of Example 1. FIG. It is a figure which shows the line profile obtained by subtracting the line profile after normalization obtained from the background image of Example 1 from the line profile after normalization obtained from the projection image of Example 1. FIG. The figure which shows the line profile obtained by smoothing the line profile obtained by subtracting the line profile after the normalization obtained from the background image of Example 1 from the line profile after the normalization obtained from the projection image of Example 1. It is.

  Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiment described here, and various modifications can be made without departing from the spirit of the present invention.

を満たす、光学積層体である。 In one embodiment of the present invention, an optical laminate of the present invention is an optical laminate having an optical film containing a polyimide resin and / or a polyamide resin and a functional layer laminated on at least one surface of the optical film. And
Line profiles in the direction h and the direction v orthogonal to each other in a film inverse aerial image obtained by Fourier transforming a projection image obtained by the projection method using the optical film are set as line profiles h and v, respectively. In the background inverse space image obtained by Fourier transforming the background image obtained without using the optical film, the line profiles in the direction h ′ and the direction v ′ orthogonal to each other are set as line profiles h ′ and v ′, respectively. Obtained by subtracting the line profile v ′ from the line profile v, where Y _mh is the maximum intensity of the line profile ( _hh ′) obtained by subtracting the line profile h ′, X _mh is the frequency indicating the maximum intensity Y _mh The maximum intensity of the line profile (v−v ′) is Y _mv and the maximum intensity Y _mv When _{X mv} frequencies indicating _{a, Y mh} and _{Y mv} is any even 40 or _{less, Y mh, Y mv, X} mh and _{X mv} is the following relationship:

An optical laminate satisfying the above requirements.

を満たす、光学積層体である。ここで、方向ｈ及び方向ｈ’は互いに対応する方向であり、方向ｖ及び方向ｖ’は互いに対応する方向である。これら方向が対応するとは、方位角が同じであることを意味する。 In another aspect of the present invention, an optical laminate according to the present invention includes an optical film containing a polyimide resin and / or a polyamide resin, and a functional layer laminated on at least one surface of the optical film. Because
In the film inverse space image obtained by Fourier transforming the projection image obtained by the projection method using the optical laminate, the line profiles in the direction h and the direction v orthogonal to each other are set as line profiles h and v, respectively. Line profiles in the direction h ′ and the direction v ′ orthogonal to each other in the background inverse aerial image obtained by Fourier transforming the background image obtained without using the optical layered body are set as line profiles h ′ and v ′, respectively. The maximum intensity of the line profile ( _hh ′) obtained by subtracting the line profile h ′ from h is Y _mh , the frequency indicating the maximum intensity Y _mh is X _mh, and the line profile v ′ is subtracted from the line profile v. Y _mv is the maximum intensity of the obtained line profile (v−v ′), and the maximum intensity Y _mv is indicated. When the to the frequency and _{X mv, Y mh} and _{Y mv} is any even 40 or _{less, Y mh, Y mv, X} mh and _{X mv} is the following relationship:

An optical laminate satisfying the above requirements. Here, the direction h and the direction h ′ are directions corresponding to each other, and the direction v and the direction v ′ are directions corresponding to each other. That these directions correspond corresponds to the same azimuth angle.

The optical laminate of the present invention is an optical laminate satisfying the above characteristics as a result of evaluating the above Y _{mh and the} like using the optical film included in the optical laminate of the present invention or the optical laminate of the present invention as a measurement film. Is the body. The optical layered body of the present invention satisfying such characteristics has high optical homogeneity. The optical layered body of the present invention has excellent optical homogeneity, and is particularly preferably used as an optical layered body in an image display device. Here, the optical homogeneity of the film is closely related to the surface unevenness, the thickness unevenness, the alignment unevenness and the like of the film, and when these unevenness occurs, the optical homogeneity is lowered. Therefore, it can be said that the optical laminated body of the present invention having excellent optical homogeneity is a film in which unevenness such as planar unevenness, thickness unevenness, and alignment unevenness is reduced.

An optical film included in the optical laminate of the present invention, or a film inverse aerial image obtained by Fourier transforming a projection image obtained by a projection method using the optical laminate of the present invention as a measurement film, and the projection The background inverse space image obtained by performing Fourier transform on the background image obtained without using the measurement film in the method is not particularly limited as long as it is obtained by Fourier transform from the projection image and the background image, respectively. ,
(1) A step of irradiating a measurement film (an optical film or an optical laminate) with light from a light source, and obtaining a projection image by a projection method in which light transmitted through the measurement film is projected onto a projection surface;
(2) A step of projecting light from a light source onto a projection surface without using a measurement film in the projection method of step (1) to obtain a background image;
as well as,
(3) The projection image obtained in step (1) and the background image obtained in step (2) are each digitized by gray scale conversion, and the digitized image data is Fourier transformed to produce an inverse aerial image (film inverse aerial image). And a background inverse aerial image). By evaluating the surface quality of the measurement film using the inverse aerial image, it is possible to analyze the density and period of the unevenness.

  The method for obtaining an inverse aerial image by Fourier transform from the projection image by the projection method of the measurement film is not particularly limited, but for example, a method described later for the evaluation step may be used.

Next, (4) a line profile that is blank-corrected by subtracting the line profiles in the two directions orthogonal to each other in the inverse space image of the background image from the line profiles in two directions orthogonal to the inverse space image of the projection image. And (5) the maximum intensity Y _max (Y _mh and Y _mv , respectively) of the blank-corrected line profile obtained in step (4), and the maximum intensity Y _max (Y _mh and The frequency X _max (X _mh and X _mv ) indicating Y _mv ) is measured. For example, a case where a line profile is created in each of the horizontal direction (h1 direction) and the vertical direction (v1 direction) passing through the center of the inverse aerial image will be described below. The line profile is shown as a graph representing frequency on the X axis and intensity on the Y axis, as shown in FIG. 3, for example. Then, the maximum intensity Y _max in the horizontal (h1 direction) line profile is _defined as Y _mh1, and a value X _max obtained by subtracting the median value X _cen of all frequencies in the blank-corrected line profile from the frequency indicating the maximum intensity Y _mh1. Let _Xmh1 . Further, the maximum intensity Y _max in the vertical (v1 direction) line profile is _defined as Y _mv1, and a value X _max obtained by subtracting the median value X _cen of all frequencies in the blank-corrected line profile from the frequency indicating the maximum intensity Y _mv1. Let X _mv1 . In the above example, the horizontal direction (h1 direction) and the vertical direction (v1 direction) passing through the center of the aerial image are selected as two orthogonal directions, but the two directions (h direction and v direction) are orthogonal to each other. As long as it is not limited, it may be two directions that do not pass through the center, and may not be in the horizontal direction and the vertical direction. In this specification, the “blank-corrected line profile” refers to each line in the two directions orthogonal to each other in the inverse aerial image of the background image from each line profile in the two orthogonal directions in the inverse aerial image of the projection image. It means a line profile obtained by subtracting each profile. With the above operation, the baseline of the line profile in the inverse space image of the projection image can be corrected.

Y _mh and Y _mv obtained using the optical film contained in the optical laminate of the present invention as a measurement film are both 40 or less. When Y _mh or Y _mv exceeds 40, it cannot be said that the optical homogeneity of the optical film is sufficient, and the optical homogeneity of the optical laminate may not be sufficient. In particular, the optical homogeneity of an optical laminate including such an optical film cannot be said to be sufficient for use in an image display device, and image distortion and the like cannot be sufficiently reduced. Y _mh and Y _mv are preferably 35 or less, more preferably 32 or less, and even more preferably 30 or less, from the viewpoint of easily improving the optical homogeneity of the optical laminate and improving the visibility of the image in the image display device. More preferably, it is 28 or less, and particularly preferably 26 or less. Y _mh and Y _mv are preferably as small as possible, and the lower limit thereof is not particularly limited and may be 0 or more, and is usually 1 or more. The above-mentioned preferable description similarly applies to the above Y _mh and Y _mv obtained by using the optical layered body of the present invention as a measurement film.

を満たす。（Ｙ_ｍｈ＋Ｙ_ｍｖ）／（Ｘ_ｍｈ＋Ｘ_ｍｖ）^１／２の値が３０を超えると、光学的均質性が十分でないために画面の歪み等が生じやすい。（Ｙ_ｍｈ＋Ｙ_ｍｖ）／（Ｘ_ｍｈ＋Ｘ_ｍｖ）^１／２の値の上限は、光学的均質性をより高めやすい観点から、好ましくは２５以下、より好ましくは２２以下、さらに好ましくは２０以下、さらに好ましくは１９．５以下、さらに好ましくは１９以下、さらに好ましくは１８以下、さらに好ましくは１７以下、さらに好ましくは１６以下、さらに好ましくは１４以下、さらに好ましくは１３以下、特に好ましくは９以下である。（Ｙ_ｍｈ＋Ｙ_ｍｖ）／（Ｘ_ｍｈ＋Ｘ_ｍｖ）^１／２の値は小さければ小さいほどよく、その下限は特に限定されず０以上であればよく、通常は０．５以上である。本発明の光学積層体を測定フィルムとして用いて得られる上記Ｙ_ｍｈ、Ｙ_ｍｖ、Ｘ_ｍｈ及びＸ_ｍｖについても、上記好ましい記載が同様にあてはまる。 Y _mh , Y _mv , X _mh and X _mv obtained as described above using the optical film contained in the optical laminate of the present invention as a measurement film have the following relationship:

Meet. If the value of (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 exceeds 30, the optical homogeneity is not sufficient, so that distortion of the screen tends to occur. The upper limit of the value of (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 is preferably 25 or less, more preferably 22 or less, still more preferably 20 or less, from the viewpoint of easily improving optical homogeneity. More preferably 19.5 or less, more preferably 19 or less, more preferably 18 or less, further preferably 17 or less, more preferably 16 or less, still more preferably 14 or less, still more preferably 13 or less, and particularly preferably 9 or less. is there. The value of (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 is preferably as small as possible. The lower limit thereof is not particularly limited and may be 0 or more, and is usually 0.5 or more. The above-mentioned preferable description similarly applies to the above Y _mh , Y _mv , X _mh and X _mv obtained using the optical laminate of the present invention as a measurement film.

を満たすことが好ましい。なお、上記の式中、Ｘ_ｍはＸ_ｍｈ又はＸ_ｍｖを表し、Ｘ_ｍｈ及びＸ_ｍｖのいずれもが上記式を満たすことが好ましい。｜Ｘ_ｍ−Ｘ_ｃｅｎ｜の下限は、より好ましくは０．５ｃｍ^−１以上、さらに好ましくは１．０ｃｍ^−１以上である。また、｜Ｘ_ｍ−Ｘ_ｃｅｎ｜の上限は、より好ましくは８．０ｃｍ^−１以下、さらに好ましくは６．０ｃｍ^−１以下である。ムラとして視認されない光学的均質性を備えることと、生産性とを考慮すると、光学フィルム又は光学積層体におけるＸ_ｍｈ及びＸ_ｍｖが上記関係を満たすことが好ましい。 Using the optical film included in the optical laminate of the present invention or the optical laminate of the present invention as the measurement film, the median value of all frequencies in the blank-corrected line profile obtained as described above is X _cen . . For example, in the line profile shown in FIG. 3, the total frequency is 90 cm ⁻¹ , and the median value of 45 cm ⁻¹ is X _cen . Here, X _cen and X _mh and X _mv obtained as described above have the following relationship:

It is preferable to satisfy. Incidentally, in the above formula, _{X m} represents the _{X mh} or _{X mv,} none of _{X mh} and _{X mv} preferably satisfies the above formula. The lower limit of | X _m −X _cen | is more preferably 0.5 cm ⁻¹ or more, and still more preferably 1.0 cm ⁻¹ or more. Moreover, the upper limit of | X _m -X _cen | is more preferably 8.0 cm ⁻¹ or less, and still more preferably 6.0 cm ⁻¹ or less. In consideration of providing optical homogeneity that is not visually recognized as unevenness and productivity, it is preferable that X _mh and X _mv in the optical film or the optical laminate satisfy the above relationship.

  The pencil hardness of at least one surface of the optical layered body of the present invention is preferably H or higher, more preferably 2H or higher, still more preferably 3H or higher, particularly preferably 4H or higher. When the pencil hardness of at least one surface of the optical laminate is equal to or higher than the above hardness, it is easy to prevent scratches on the surface of the optical laminate. The pencil hardness is preferably the pencil hardness of the surface having the functional layer (preferably a hard coat layer) of the optical layered body of the present invention. In addition, pencil hardness can be measured based on JISK5600-5-4: 1999, for example, can be measured by the method as described in an Example.

The surface resistivity of at least one surface of the optical layered body of the present invention is preferably 1.0 × 10 ¹³ Ω / sq or less, more preferably 5.0 × 10 ¹² Ω / sq or less, and still more preferably 1.0. × 10 ¹² Ω / sq or less. When the surface resistivity is not more than the above upper limit, it is easy to obtain a sufficient antistatic function. The surface resistivity of at least one surface of the optical laminate of the present invention is preferably 1.0 from the viewpoint of easily ensuring the operability of the touch panel when the optical laminate of the present invention is used in combination with the touch panel. × 10 ⁷ Ω / sq or more, more preferably 5.0 × 10 ⁷ Ω / sq or more, and further preferably 1.0 × 10 ⁸ Ω / sq or more. The surface resistivity is preferably the surface resistivity of the surface having the functional layer (preferably the antistatic functional layer) of the optical layered body of the present invention. In addition, surface resistivity can be measured based on JISK6911, for example, can be measured by the method as described in an Example.

  In the optical laminate of the present invention, the reflectance of the optical laminate when light is incident from the surface having the functional layer is preferably 3.0% or less, more preferably 2.0% or less, and still more preferably 1. 0% or less. In addition, the reflectance in this specification means a visibility correction reflectance, and specifically, the spectral reflectance in the wavelength range of 350 to 900 nm at a reflection angle of 12 degrees when light is incident at an incident angle of 12 degrees. This is the reflectance obtained by correcting the visibility (that is, the regular reflectance at an incident angle of 12 degrees) with a 2 degree visual field (C light source) of JIS Z 8701. The reflectance can be measured using a spectrophotometer or the like. In the measurement of reflectance, for the purpose of eliminating the possibility that reflection from the surface opposite to the functional layer surface on which light is incident will affect the measurement value, and for the purpose of preventing warpage of the optical laminate, A sample in which the surface of the optical laminate opposite to the functional layer surface on which light is incident is bonded to a black plate (black acrylic plate or the like) using an optically transparent adhesive is used as a measurement sample.

  The yellowness (YI value) of the optical layered body of the present invention is preferably 3.0 or less, more preferably 2.7 or less, further preferably 2.5 or less, and particularly preferably 2.0 or less. When the yellowness of the optical layered body is not more than the above upper limit, it is easy to improve transparency. For example, when used for a front plate of a display device, it is easy to improve visibility. The yellowness is usually −5 or more, preferably −2 or more, more preferably 0 or more, still more preferably 0.3 or more, still more preferably 0.5 or more, and particularly preferably 0.7 or more. Yellowness (YI) is measured in accordance with JIS K 7373: 2006 by measuring transmittance with respect to light of 300 to 800 nm using an ultraviolet-visible-near infrared spectrophotometer, and tristimulus values (X, Y, Z). Can be calculated based on the equation YI = 100 × (1.2769X−1.0592Z) / Y.

  The total light transmittance of the optical layered body of the present invention is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more. When the total light transmittance is equal to or higher than the above lower limit, it is easy to improve the visibility when the optical layered body is incorporated in an image display device. Since the optical laminate of the present invention has high optical homogeneity and high transmittance, for example, a display element necessary for obtaining a certain brightness as compared with the case of using a film with low transmittance. The emission intensity can be suppressed. For this reason, power consumption can be reduced. For example, when the optical layered body of the present invention is incorporated in a display device, there is a tendency that a bright display can be obtained even if the amount of light of the backlight is reduced, which can contribute to energy saving. The upper limit of the total light transmittance is usually 100% or less. In addition, total light transmittance can be measured using a haze computer based on JISK7361-1: 1997, for example. The total light transmittance may be a total light transmittance in the thickness range of the optical layered body described later.

  The haze of the optical layered body of the present invention is preferably 3.0% or less, more preferably 2.0% or less, still more preferably 1.0% or less, still more preferably 0.5% or less, and particularly preferably 0. .3% or less. When the haze of the optical layered product is not more than the above upper limit, the transparency becomes good, and for example, when used for a front plate of an image display device, it is easy to improve image visibility. The lower limit of haze is usually 0.01% or more. In addition, haze can be measured using a haze computer based on JISK7136: 2000.

  The thickness of the optical layered body of the present invention may be appropriately adjusted according to the use, but is preferably 25 μm or more, more preferably 27 μm or more, further preferably 30 μm or more, preferably 100 μm or less, more preferably 90 μm. Hereinafter, it is more preferably 85 μm or less. The thickness of the optical layered body can be measured with a film thickness meter or the like, for example, by the method described in the examples.

The optical laminate of the present invention has an optical film containing a polyimide resin and / or a polyamide resin and a functional layer laminated on at least one surface of the optical film. From the viewpoint of easily producing a highly homogenous optical film having the above-mentioned characteristics relating to Y _mh and / or from the viewpoint of easily producing a highly homogenous optical laminated body having the above-mentioned characteristics, The optical film is preferably a cast film. In this specification, the cast film refers to, for example, casting, coating, etc. a solution, dispersion, or melt containing the above resin on a suitable support, and forming a coating film by heating, cooling, drying, or the like. And a film obtained by peeling the coating film from the support as necessary. The film thus obtained contains at least a polyimide resin and / or a polyamide resin, and optionally contains a trace amount of a solvent.

  The optical film in the optical layered body of the present invention contains a polyimide resin and / or a polyamide resin. In the optical laminate of the present invention, the optical film may contain one type of polyimide resin or polyamide resin, or may contain two or more types of polyimide resin and / or polyamide resin.

<Polyimide resin and polyamide resin>
In the optical laminate of the present invention, the optical film contains a polyimide resin and / or a polyamide resin. Polyimide resin is a resin containing a repeating structural unit containing an imide group (hereinafter sometimes referred to as a polyimide resin) and a resin containing a repeating structural unit containing both an imide group and an amide group (hereinafter referred to as a polyamideimide). And at least one resin selected from the group consisting of resin (sometimes referred to as resin). Moreover, a polyamide-type resin shows resin containing the repeating structural unit containing an amide group.

In a preferred embodiment of the present invention, the polyimide resin is a polyimide resin having a structural unit represented by the formula (1), or a structural unit represented by the formula (1) and the formula (2). It is preferable that it is a polyamide imide resin which has a structural unit represented. Moreover, it is preferable that a polyamide-type resin is a polyamide resin which has a structural unit represented by Formula (2). In the following, formula (1) and formula (2) will be described. The description of formula (1) relates to both polyimide resin and polyamideimide resin, and the description of formula (2) applies to polyamide resin and polyamideimide resin. Concerning both.

  The structural unit represented by the formula (1) is a structural unit formed by the reaction of a tetracarboxylic acid compound and a diamine compound, and the structural unit represented by the formula (2) is a dicarboxylic acid compound and a diamine compound. Is a structural unit formed by the reaction.

  In the formula (2), Z is a divalent organic group, which may be preferably substituted with a hydrocarbon group having 1 to 8 carbon atoms or a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms. A cyclic structure which is a divalent organic group having 4 to 40 carbon atoms, and more preferably a hydrocarbon group having 1 to 8 carbon atoms or a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms. And a divalent organic group having 4 to 40 carbon atoms. Examples of the cyclic structure include alicyclic rings, aromatic rings, and heterocyclic structures. As an organic group of Z, formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (described later) 28) and the group represented by formula (29), a group in which two non-adjacent groups are replaced by hydrogen atoms and a divalent chain hydrocarbon group having 6 or less carbon atoms are exemplified, and a heterocycle of Z Examples of the structure include groups having a thiophene ring skeleton. From the viewpoint of easily suppressing the yellowness of the optical film (reducing the YI value), groups represented by the formulas (20) to (27) and a group having a thiophene ring skeleton are preferable.

［式（３）中、Ｒ^１〜Ｒ^８は、互いに独立に、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、又は炭素数６〜１２のアリール基を表し、Ｒ^１〜Ｒ^８に含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、
Ａは、互いに独立に、単結合、−Ｏ−、−ＣＨ_２−、−ＣＨ_２−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−ＳＯ_２−、−Ｓ−、−ＣＯ−又は−Ｎ（Ｒ^９）−を表し、Ｒ^９は水素原子、ハロゲン原子で置換されていてもよい炭素数１〜１２の１価の炭化水素基を表し、
ｍは０〜４の整数であり、
＊は結合手を表す］
で表されることが好ましい。 In one embodiment of the present invention, the polyamide resin and the polyamideimide resin may include a plurality of types of Z, and the plurality of types of Z may be the same as or different from each other. In particular, from the viewpoint of easily increasing the surface hardness of the optical film and from the viewpoint of easily improving the optical characteristics, at least a part of Z is represented by the formula (3).

[In Formula (3), R ^{1 to} R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. , R ^{1 to} R ⁸ may be each independently substituted with a halogen atom,
A is, independently of one another, a single _{bond, -O -, - CH 2 -} , - CH 2 -CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - C (CF 3) _2- , -SO _2- , -S-, -CO- or -N (R ⁹ )-, wherein R ⁹ is a hydrogen atom or a monovalent monovalent having 1 to 12 carbon atoms which may be substituted with a halogen atom. Represents a hydrocarbon group,
m is an integer from 0 to 4,
* Represents a bond]
It is preferable to be represented by

In the formula (3), A is a single _{bond, -O -, - CH 2 -} , - CH 2 -CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - C (CF ₃ ) ₂ —, —SO ₂ —, —S—, —CO— or —N (R ⁹ ) —, preferably from the viewpoint of the flex resistance of the optical film, —O— or —S—, More preferably, -O- is represented.
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, Alternatively, it represents an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, 2-methyl- Examples thereof include a butyl group, a 3-methylbutyl group, a 2-ethyl-propyl group, and an n-hexyl group. Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butoxy group, isobutoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group and the like. Can be mentioned. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a biphenyl group. From the viewpoint of the surface hardness and flexibility of the optical film, R ^{1 to} R ⁸ preferably independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or 1 to 3 carbon atoms. And more preferably a hydrogen atom. Here, the hydrogen atoms contained in R ^{1 to} R ⁸ may be independently substituted with halogen atoms.
R ⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, 2-methyl-butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group, n-decyl group, etc. These may be substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. A polyimide-type resin or a polyamide-type resin may contain multiple types of A, and multiple types of A may mutually be the same and may differ.

  In Formula (3), m is an integer in the range of 0 to 4, and if m is within this range, the flex resistance and elastic modulus of the optical film are likely to be good. In formula (3), m is preferably an integer in the range of 0 to 3, more preferably 0 to 2, still more preferably 0 or 1, and particularly preferably 0. When m is within this range, it is easy to improve the flex resistance and elastic modulus of the optical film. Z may contain one or more structural units represented by the formula (3), from the viewpoint of improving the elastic modulus and flex resistance of the optical film and reducing the yellowness (YI value). In particular, two or more types of structural units having different values of m, preferably two types of structural units having different values of m may be included. In that case, the resin contains a structural unit represented by the formula (3) in which m is 0 from the viewpoint of easily exhibiting high elastic modulus, flex resistance and low yellowness (YI value) of the optical film. It is preferable to further include a structural unit represented by the formula (3) in which m is 1 in addition to the structural unit.

で表される構成単位を有する。この場合、光学フィルムの表面硬度及び耐屈曲性を向上させやすく、黄色度を低減しやすい。 In a preferred embodiment of the present invention, the resin has a structural unit represented by the formula (3) in which m = 0 and R ^{5 to} R ⁸ are hydrogen atoms. In a more preferred embodiment of the present invention, the resin is a structural unit represented by the formula (3), wherein m = 0 and R ^{5 to} R ⁸ are hydrogen atoms, and the formula (3 ′ ):

It has a structural unit represented by In this case, it is easy to improve the surface hardness and flex resistance of the optical film, and to easily reduce the yellowness.

  In a preferred embodiment of the present invention in which the optical laminate has an optical film containing a polyamideimide resin, the structural unit represented by the formula (1) and the structural unit represented by the formula (2) of the polyamideimide resin. When the total is 100 mol%, the proportion of the structural unit represented by the formula (3) is preferably 20 mol% or more, more preferably 30 mol% or more, still more preferably 40 mol% or more, particularly preferably. It is 50 mol% or more, most preferably 60 mol% or more, preferably 90 mol% or less, more preferably 85 mol% or less, and further preferably 80 mol% or less. When the proportion of the structural unit represented by the formula (3) is not less than the above lower limit, the surface hardness of the optical film can be easily increased, and the flex resistance and the elastic modulus can be easily increased. When the proportion of the structural unit represented by the formula (3) is not more than the above upper limit, the increase in the viscosity of the resin-containing varnish due to the hydrogen bond between the amide bonds derived from the formula (3) is suppressed, and the film processability is improved. Cheap.

Further, when the polyamideimide resin has a structural unit of the formula (3) where m = 1 to 4, the structural unit represented by the formula (1) and the structural unit represented by the formula (2) of the polyamideimide resin When the total is 100 mol%, the proportion of the structural unit of the formula (3) in which m is 1 to 4 is preferably 3 mol% or more, more preferably 5 mol% or more, further preferably 7 mol% or more. In particular, it is 9 mol% or more, preferably 90 mol% or less, more preferably 70 mol% or less, still more preferably 50 mol% or less, and particularly preferably 30 mol% or less. When the proportion of the structural unit of the formula (3) in which m is 1 to 4 is equal to or more than the above lower limit, the surface hardness and the bending resistance of the optical film can be easily increased. When the proportion of the structural unit of the formula (3) in which m is 1 to 4 is not more than the above upper limit, the increase in the viscosity of the resin-containing varnish due to the hydrogen bond between amide bonds derived from the formula (3) is suppressed, and film processing Easy to improve. Note that equation (1), formula (2) or the content of the constitutional unit represented by the formula (3) may be, for example, be measured using ^{1 H-NMR,} or be calculated from the raw material charging ratio of You can also.

In a preferred embodiment of the present invention, Z in the polyamide resin or polyamideimide resin is preferably 30 mol% or more, more preferably 40 mol% or more, further preferably 45 mol% or more, and further preferably 50 mol%. As mentioned above, 70 mol% or more is a structural unit represented by Formula (3) whose m is 0-4. When the above lower limit of Z is a structural unit represented by the formula (3) in which m is 0 to 4, it is easy to increase the surface hardness of the optical film, and it is easy to increase the bending resistance and the elastic modulus. Moreover, 100 mol% or less of Z in a polyamide resin or a polyamideimide resin should just be a structural unit represented by Formula (3) whose m is 0-4. Incidentally, in the resin, m is the amount of the structural unit represented by the formula (3) is 0-4, for example it can be determined using ^{1 H-NMR,} or be calculated from the charging ratio of the raw materials You can also.

In a preferred embodiment of the present invention, Z in the polyamide resin or polyamideimide resin is preferably 5 mol% or more, more preferably 8 mol% or more, further preferably 10 mol% or more, particularly preferably 12 mol%. The above is represented by Formula (3) where m is 1 to 4. When the above lower limit of Z of the polyamideimide resin is represented by the formula (3) in which m is 1 to 4, it is easy to increase the surface hardness of the optical film, and it is easy to increase the bending resistance and the elastic modulus. Further, Z, preferably 90 mol% or less, more preferably 70 mol% or less, further preferably 50 mol% or less, particularly preferably 30 mol% or less, is represented by formula (3) in which m is 1 to 4. It is preferred that When the above upper limit of Z is expressed by the formula (3) in which m is 1 to 4, the viscosity increase of the resin-containing varnish due to the hydrogen bond between amide bonds derived from the formula (3) in which m is 1 to 4 It is easy to improve the workability of the film. Note the amount of the structural units m in the resin is represented by formula (3) is 1 to 4 can also be calculated from, for example, ^{1 H-NMR} can be measured using, or the material feed ratio .

  In the formula (1) and the formula (2), X represents a divalent organic group independently of each other, preferably a divalent organic group having 4 to 40 carbon atoms, more preferably 4 carbon atoms having a cyclic structure. Represents a divalent organic group of ˜40. Examples of the cyclic structure include alicyclic rings, aromatic rings, and heterocyclic structures. In the organic group, a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. In this case, the number of carbon atoms of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably Is 1-8. In one embodiment of the present invention, the polyimide resin or the polyamideimide resin may include a plurality of types of X, and the plurality of types of X may be the same as or different from each other. X is represented by Formula (10), Formula (11), Formula (12), Formula (13), Formula (14), Formula (15), Formula (16), Formula (17), and Formula (18). Groups in which the hydrogen atoms in the groups represented by the formulas (10) to (18) are substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and those having 6 or less carbon atoms A chain hydrocarbon group is exemplified.

In formula (10) to formula (18), * represents a bond,
V ^{1, V 2} and ^{V 3} independently of one another, a single _{bond, -O -, - S -,} - CH 2 -, - CH 2 -CH 2 -, - CH (CH 3) -, - C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO _2- , -CO- or -N (Q)-. Here, Q represents a C1-C12 monovalent hydrocarbon group which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include the groups described above for R ⁹ .
In one example, V ¹ and V ³ are a single bond, —O— or —S—, and V ² is —CH ₂ —, —C (CH ₃ ) ₂ —, —C (CF ₃ ) _2. - or -SO ₂ - is. The bonding position of V ¹ and V ² with respect to each ring and the bonding position of V ² and V ³ with respect to each ring are independently of each other, preferably in the meta position or the para position with respect to each ring, and more preferably Is para.

Among the groups represented by the formulas (10) to (18), from the viewpoint of easily increasing the surface hardness and flex resistance of the optical film, the formulas (13), (14), (15), and (16) ) And groups represented by formula (17) are preferred, and groups represented by formula (14), formula (15) and formula (16) are more preferred. V ¹ , V ² and V ³ are preferably a single bond, —O— or —S— independently of each other from the viewpoint of easily increasing the surface hardness and flexibility of the optical film. More preferably, it is O-.

［式（４）中、Ｒ^１０〜Ｒ^１７は、互いに独立に、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基又は炭素数６〜１２のアリール基を表し、Ｒ^１０〜Ｒ^１７に含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、＊は結合手を表す］
で表される構成単位である。式（１）及び式（２）中の複数のＸの少なくとも一部が式（４）で表される基であると、光学フィルムの表面硬度及び透明性を高めやすい。 In a preferred embodiment of the present invention, at least some of the plurality of Xs in the formulas (1) and (2) are represented by the formula (4):

Wherein ^{(4), R} 10 ~R ^17, independently of each other, represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group or an aryl group having 6 to 12 carbon atoms having 1 to 6 carbon atoms, The hydrogen atoms contained in R ^{10 to} R ¹⁷ may be independently substituted with halogen atoms, and * represents a bond.
It is a structural unit represented by When at least a part of the plurality of Xs in the formulas (1) and (2) is a group represented by the formula (4), the surface hardness and transparency of the optical film can be easily increased.

In Formula (4), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 carbon atom. Represents a C6 alkoxy group or a C6-12 aryl group. As an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms in formula (3) The thing of an illustration is mentioned as a group or a C6-C12 aryl group. R ^{10 to} R ¹⁷ independently of each other preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, where R ¹⁰ to R ¹⁰ The hydrogen atoms contained in R ¹⁷ may be independently substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R ^{10 to} R ¹⁷ are more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group, or a trifluoromethyl group, independently of each other, from the viewpoints of the surface hardness, transparency, and bending resistance of the optical film. Preferably, R ¹⁰ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are hydrogen atoms, R ¹¹ and R ¹⁷ are hydrogen atoms, methyl groups, fluoro groups, chloro groups or trifluoromethyl groups, particularly preferred R ¹¹ and R ¹⁷ are a methyl group or a trifluoromethyl group.

で表される構成単位であり、すなわち、複数のＸの少なくとも一部は、式（４’）で表される構成単位である。この場合、フッ素元素を含有する骨格によりポリイミド系樹脂又はポリアミド系樹脂の溶媒への溶解性を高め、該樹脂を含有するワニスの保管安定性を向上しやすいと共に、該ワニスの粘度を低減しやすく、光学フィルムの加工性を向上しやすい。また、フッ素元素を含有する骨格により、光学フィルムの光学特性を向上しやすい。 In a preferred embodiment of the present invention, the structural unit represented by the formula (4) is represented by the formula (4 ′):

That is, at least a part of the plurality of Xs is a structural unit represented by the formula (4 ′). In this case, the skeleton containing the fluorine element increases the solubility of the polyimide resin or polyamide resin in the solvent, and it is easy to improve the storage stability of the varnish containing the resin, and to easily reduce the viscosity of the varnish. It is easy to improve the workability of the optical film. Moreover, it is easy to improve the optical characteristics of the optical film due to the skeleton containing elemental fluorine.

In one preferred embodiment of the present invention, X in the polyimide resin or polyamide resin is preferably 30 mol% or more, more preferably 50 mol% or more, and even more preferably 70 mol% or more of formula (4), In particular, it is represented by the formula (4 ′). When X in the above range in the polyimide resin or polyamide resin is represented by the formula (4), particularly the formula (4 ′), the solubility of the resin in the solvent is easily improved by the skeleton containing the fluorine element, While it is easy to improve the storage stability of the varnish containing this resin, it is easy to reduce the viscosity of this varnish and to improve the workability of an optical film. In addition, the optical properties of the optical film are easily improved by the skeleton containing elemental fluorine. In addition, Preferably, 100 mol% or less of X in the said polyimide resin or polyamide-type resin is represented by Formula (4), especially Formula (4 '). X in the polyamide-imide resin may be the formula (4), particularly the formula (4 ′). The proportion of the structural unit represented by the formula (4) of X in the resin can be measured, for example, using ¹ H-NMR, or can be calculated from the raw material charge ratio.

  In the formula (1), Y represents a tetravalent organic group, preferably a tetravalent organic group having 4 to 40 carbon atoms, and more preferably a tetravalent organic group having 4 to 40 carbon atoms having a cyclic structure. Represents. Examples of the cyclic structure include alicyclic rings, aromatic rings, and heterocyclic structures. The organic group is an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. In this case, the hydrocarbon group and the fluorine-substituted hydrocarbon group Preferably carbon number is 1-8. In an embodiment of the present invention, the polyimide-based resin may include a plurality of types of Y, and the plurality of types of Y may be the same as or different from each other. As Y, the following formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) And a group represented by formula (29); a group in which a hydrogen atom in the group represented by formula (20) to formula (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group And a tetravalent chain hydrocarbon group having 6 or less carbon atoms.

In formula (20)-formula (29),
* Represents a bond,
W ¹ represents a single _{bond, -O -, - CH 2 -} , - CH 2 -CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - C (CF 3) 2 -, _{-Ar -, - SO 2 -,} - CO -, - O-Ar-O -, - Ar-O-Ar -, - Ar-CH 2 -Ar -, - Ar-C (CH 3) 2 -Ar- or an _-Ar-SO 2 -Ar-. Ar represents an arylene group having 6 to 20 carbon atoms in which a hydrogen atom may be substituted with a fluorine atom, and specific examples thereof include a phenylene group.

Among groups represented by formula (20) to formula (29), groups represented by formula (26), formula (28), or formula (29) are provided from the viewpoint of the surface hardness and flex resistance of the optical film. A group represented by formula (26) is more preferable. Further, ^{W 1} is easy to increase the surface hardness and flexibility of the optical film, from the viewpoint of easily decreased yellowness, independently of one another, a single _{bond, -O -, - CH 2 -} , - CH 2 -CH 2 -, -CH (CH ₃ )-, -C (CH ₃ ) ₂ -or -C (CF ₃ ) _2- are preferable, and a single bond, -O-, -CH _2- , -CH (CH ₃ )-, -C (CH ₃ ) ₂ -or -C (CF ₃ ) _2- , more preferably a single bond, -C (CH ₃ ) ₂ -or -C (CF ₃ ) _2-. Is more preferable.

［式（５）中、Ｒ^１８〜Ｒ^２５は、互いに独立に、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基又は炭素数６〜１２のアリール基を表し、Ｒ^１８〜Ｒ^２５に含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、
＊は結合手を表す］
で表される構成単位である。式（１）中の複数のＹの少なくとも一部が式（５）で表される基であると、ポリイミド系樹脂の溶媒への溶解性を高め、ポリイミド系樹脂を含有するワニスの粘度を低減しやすく、光学フィルムの加工性を向上しやすい。また、光学フィルムの光学特性を向上しやすい。 In a preferred embodiment of the present invention, at least some of the plurality of Ys in the formula (1) are represented by the formula (5):

Wherein ^{(5), R} 18 ~R ^25, independently of each other, represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group or an aryl group having 6 to 12 carbon atoms having 1 to 6 carbon atoms, The hydrogen atoms contained in R ^{18 to} R ²⁵ may be independently substituted with halogen atoms,
* Represents a bond]
It is a structural unit represented by When at least a part of the plurality of Y in the formula (1) is a group represented by the formula (5), the solubility of the polyimide resin in the solvent is increased and the viscosity of the varnish containing the polyimide resin is reduced. It is easy to improve and it is easy to improve the workability of the optical film. Moreover, it is easy to improve the optical characteristics of the optical film.

In the formula (5), R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 carbon atom. Represents a C6 alkoxy group or a C6-12 aryl group. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, and the aryl group having 6 to 12 carbon atoms include an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms in the formula (3). Examples of the group or aryl group having 6 to 12 carbon atoms include those exemplified above. R ¹⁸ to R ²⁵ are, independently of one another, preferably an alkyl group having 1 to 6 carbon hydrogen atom or atoms, more preferably represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, ^{wherein, R 18} ~ The hydrogen atom contained in R ²⁵ may be substituted with a halogen atom independently of each other. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R ^{18 to} R ²⁵ are each independently preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group, or a trifluoromethyl group from the viewpoint of easily improving the surface hardness, flex resistance, and transparency of the optical film. More preferably, R ¹⁸ , R ¹⁹ , R ²⁰ , R ²³ , R ²⁴ and R ²⁵ are hydrogen atoms, R ²¹ and R ²² are hydrogen atoms, methyl groups, fluoro groups, chloro groups or trifluoromethyl groups. And R ²¹ and R ²² are particularly preferably a methyl group or a trifluoromethyl group.

で表される基であり、すなわち、複数のＹの少なくとも一部は、式（５’）で表される構成単位である。この場合、フッ素元素を含有する骨格によりポリイミド系樹脂の溶媒への溶解性を高め、該樹脂を含有するワニスの保管安定性を向上しやすいと共に、該ワニスの粘度を低減しやすく、光学フィルムの加工性を向上しやすい。また、フッ素元素を含有する骨格により、光学フィルムの光学特性を向上しやすい。 In a preferred embodiment of the present invention, the structural unit represented by the formula (5) is represented by the formula (5 ′):

That is, at least a part of the plurality of Y is a structural unit represented by the formula (5 ′). In this case, the skeleton containing the fluorine element increases the solubility of the polyimide resin in the solvent, and it is easy to improve the storage stability of the varnish containing the resin, and to easily reduce the viscosity of the varnish. Easy to improve processability. Moreover, it is easy to improve the optical characteristics of the optical film due to the skeleton containing elemental fluorine.

In a preferred embodiment of the present invention, Y in the polyimide-based resin is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more, represented by the formula (5), particularly the formula (5 ') When Y within the above range in the polyimide resin is represented by the formula (5), especially the formula (5 ′), the skeleton containing the fluorine element increases the solubility of the polyimide resin in the solvent and contains the resin. It is easy to reduce the viscosity of the varnish and improve the workability of the optical film. Moreover, it is easy to improve the optical characteristics of the optical film due to the skeleton containing elemental fluorine. In addition, Preferably, 100 mol% or less of Y in the said polyimide resin is represented by Formula (5), especially Formula (5 '). Y in the polyimide resin may be the formula (5), particularly the formula (5 ′). The proportion of the structural unit represented by the formula (5) of Y in the polyimide resin can be measured, for example, using ¹ H-NMR, or can be calculated from the raw material charge ratio.

In addition to the structural units represented by the formulas (1) and (2), the polyimide resin or the polyamide-based resin has a structural unit represented by the formula (30) and / or a structure represented by the formula (31). Units can be included.

In Formula (30), Y ¹ is a tetravalent organic group, preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. The Y ^1, equation (20), equation (21), equation (22), equation (23), equation (24), equation (25), equation (26), equation (27), equation (28) and A group represented by formula (29), a group in which a hydrogen atom in the group represented by formula (20) to formula (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, In addition, a tetravalent chain hydrocarbon group having 6 or less carbon atoms is exemplified. In one embodiment of the present invention, the polyimide resin or the polyamide resin may include a plurality of types of Y ¹ , and the plurality of types of Y ¹ may be the same as or different from each other.

In Formula (31), Y ² is a trivalent organic group, preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. The Y ^2, the above equation (20), equation (21), equation (22), equation (23), equation (24), equation (25), equation (26), equation (27), formula (28 ) And a group represented by the formula (29), a group in which any one of the bond hands is replaced with a hydrogen atom, and a trivalent chain hydrocarbon group having 6 or less carbon atoms are exemplified. In one embodiment of the present invention, the polyimide resin or the polyamide resin may include a plurality of types of Y ² , and the plurality of types of Y ² may be the same as or different from each other.

In Formula (30) and Formula (31), X ¹ and X ² are each independently a divalent organic group, and preferably a hydrogen group in the organic group is a hydrocarbon group or a fluorine-substituted hydrocarbon group An organic group which may be substituted with X ¹ and X ² include the above formula (10), formula (11), formula (12), formula (13), formula (14), formula (15), formula (16), formula (17) and A group represented by formula (18); a group in which hydrogen atoms in the groups represented by formula (10) to formula (18) are substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and Examples are chain hydrocarbon groups having 6 or less carbon atoms.

In one embodiment of the present invention, the polyimide-based resin or the polyamide-based resin is represented by the structural unit represented by the formula (1) and / or the formula (2), and optionally the formula (30) and / or the formula (31). Consists of represented structural units. In addition, from the viewpoint of optical properties, surface hardness, and bending resistance of the optical film, in the polyimide resin or polyamide resin, the structural units represented by the formula (1) and the formula (2) are represented by the formula (1) and Based on the formula (2) and optionally all the structural units represented by the formula (30) and the formula (31), preferably 80 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more. It is. In the polyimide resin or the polyamide resin, the structural units represented by the formula (1) and the formula (2) are represented by the formula (1) and the formula (2), and in some cases, the formula (30) and / or the formula ( Based on all structural units represented by 31), it is usually 100% or less. The above ratio is, for example, can also be calculated from ^{1 H-NMR} can be measured using, or the material feed ratio.

  In one embodiment of the present invention, the content of the polyimide resin and / or polyamide resin in the optical film is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, with respect to 100 parts by mass of the optical film. More preferably, it is 50 mass parts or more, Preferably it is 99.5 mass parts or less, More preferably, it is 95 mass parts or less. When the content of the polyimide resin and / or the polyamide resin is within the above range, the optical characteristics and elastic modulus of the optical film are easily improved.

  The weight average molecular weight (Mw) of the polyimide resin or polyamide resin is preferably 230,000 or more, more preferably 250,000 or more, in terms of standard polystyrene, from the viewpoint of easily increasing the surface hardness and flex resistance of the optical film. More preferably, it is 270,000 or more, and particularly preferably 300,000 or more. In addition, the resin preferably has a weight average molecular weight of 1,000,000 from the viewpoint of easily improving the solubility of the polyamide-based resin or polyimide-based resin in the solvent and easily improving the stretchability and workability of the optical film. Hereinafter, more preferably 800,000 or less, still more preferably 700,000 or less, and particularly preferably 500,000 or less. A weight average molecular weight can be calculated | required by GPC measurement, for example by standard polystyrene conversion, for example, and may be computed by the method as described in an Example, for example.

  In the polyamideimide resin, the content of the structural unit represented by the formula (2) is preferably 0.1 mol or more, more preferably 0.5 mol, relative to 1 mol of the structural unit represented by the formula (1). Mol or more, more preferably 1.0 mol or more, particularly preferably 1.5 mol or more, preferably 6.0 mol or less, more preferably 5.0 mol or less, still more preferably 4.5 mol or less. . It is easy to raise the surface hardness of an optical film as content of the structural unit represented by Formula (2) is more than said lower limit. Further, when the content of the structural unit represented by the formula (2) is not more than the above upper limit, the thickening due to the hydrogen bond between the amide bonds in the formula (2) is suppressed, and the processability of the optical film is improved. Easy to make.

  In a preferred embodiment of the present invention, the polyimide resin or polyamide resin contained in the optical film in the optical laminate of the present invention is a halogen such as a fluorine atom that can be introduced, for example, by the fluorine-containing substituent described above. It may contain atoms. When the polyimide resin or the polyamide resin contains a halogen atom, it is easy to improve the elastic modulus of the optical film and reduce the yellowness (YI value). When the elastic modulus of the optical film is high, when the optical film is used in, for example, a flexible display device, it is easy to suppress generation of scratches and wrinkles in the film. Moreover, when the yellowness of an optical film is low, it becomes easy to improve the transparency and visibility of the optical film. The halogen atom is preferably a fluorine atom. Preferred fluorine-containing substituents for incorporating a fluorine atom into a polyimide resin or polyamide resin include, for example, a fluoro group and a trifluoromethyl group.

  The halogen atom content in the polyimide resin or polyamide resin is preferably 1 to 40% by mass, more preferably 5 to 40% by mass, and still more preferably 5 to 5%, based on the mass of the polyimide resin or polyamide resin. 30% by mass. When the halogen atom content is not less than the above lower limit, the elastic modulus of the optical film is further improved, the water absorption is decreased, the yellowness is further decreased, and the transparency and the visibility are easily improved. When the halogen atom content is not more than the above upper limit, the resin can be easily synthesized.

  The imidization ratio of the polyimide resin and the polyamideimide resin is preferably 90% or more, more preferably 93% or more, and still more preferably 96% or more. From the viewpoint of easily improving the optical homogeneity of the optical film and / or the optical laminate, it is preferable that the imidization ratio is not less than the above lower limit. Moreover, the upper limit of the imidation rate is 100% or less. The imidation ratio indicates the ratio of the molar amount of the imide bond in the polyimide resin and the polyamideimide resin to the value twice the molar amount of the structural unit derived from the tetracarboxylic acid compound in the polyimide resin or the polyamideimide resin. When the polyimide resin and the polyamideimide resin contain a tricarboxylic acid compound, the value is twice the molar amount of the structural unit derived from the tetracarboxylic acid compound in the polyimide resin and the polyamideimide resin, and is derived from the tricarboxylic acid compound. The ratio of the molar amount of the imide bond in the polyimide resin and the polyamide-imide resin with respect to the total of the molar amount of the structural units to be performed is shown. Further, the imidization rate can be determined by IR method, NMR method, etc. For example, in NMR method, it can be measured by the method described in Examples.

  Commercially available products may be used as the polyimide resin and the polyamide resin. Examples of commercially available polyimide resins include Neoprim (registered trademark) manufactured by Mitsubishi Gas Chemical Co., Ltd. and KPI-MX300F manufactured by Kawamura Sangyo Co., Ltd.

  Regarding the various properties of the optical laminate of the present invention, the properties of the optical laminate, such as yellowness, surface hardness, optical properties, flex resistance, flexibility, elastic modulus, transparency, visibility and water absorption, When yellowness, surface hardness, optical properties, flex resistance, flexibility, elastic modulus, transparency, visibility, water absorption, and the like are improved, there is a tendency to be able to be improved similarly. Characteristics such as the surface hardness and pencil hardness of the surface having the functional layer of the optical layered body are easily affected by the type of the functional layer.

［式（３”）中、Ｒ^１〜Ｒ^８は、互いに独立に、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、又は炭素数６〜１２のアリール基を表し、Ｒ^１〜Ｒ^８に含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、
Ａは、単結合、−Ｏ−、−ＣＨ_２−、−ＣＨ_２−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−ＳＯ_２−、−Ｓ−、−ＣＯ−又は−Ｎ（Ｒ^９）−を表し、
Ｒ^９は水素原子、ハロゲン原子で置換されていてもよい炭素数１〜１２の１価の炭化水素基を表し、
ｍは０〜４の整数であり、
Ｒ^３１及びＲ^３２は、互いに独立に、ヒドロキシル基、メトキシ基、エトキシ基、ｎ−プロポキシ基、イソプロポキシ基、ｎ−ブトキシ基、ｓｅｃ−ブトキシ基、ｔｅｒｔ−ブトキシ基又は塩素原子を表す。］ <Production method of resin>
For example, the polyimide resin can be manufactured using a tetracarboxylic acid compound and a diamine compound as main raw materials, and the polyamideimide resin can be manufactured using, for example, a tetracarboxylic acid compound, a dicarboxylic acid compound and a diamine compound as main raw materials. For example, a dicarboxylic acid compound and a diamine compound can be produced as main raw materials. Here, the dicarboxylic acid compound preferably contains at least a compound represented by the formula (3 ″).

[In Formula (3 ″), R ^{1 to} R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. And hydrogen atoms contained in R ^{1 to} R ⁸ may be independently substituted with halogen atoms,
A represents a single _{bond, -O -, - CH 2 -} , - CH 2 -CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - C (CF 3) 2 -, - SO _2- , -S-, -CO- or -N (R ⁹ )-
R ⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom;
m is an integer from 0 to 4,
R ³¹ and R ³² each independently represent a hydroxyl group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group or chlorine atom. ]

In a preferred embodiment of the present invention, the dicarboxylic acid compound is a compound represented by the formula (3 ″) in which m is 0. The dicarboxylic acid compound is represented by the formula (3 ″) in which m is 0. In addition to the above compound, it is more preferable to use a compound represented by the formula (3 ″) in which A is an oxygen atom. In another preferred embodiment, the dicarboxylic acid compound is R ³¹ , It is a compound represented by the formula (3 ″), wherein R ³² is a chlorine atom. Further, a diisocyanate compound may be used in place of the diamine compound.

  As a diamine compound used for manufacture of resin, an aliphatic diamine, aromatic diamine, and a mixture thereof are mentioned, for example. In the present embodiment, the “aromatic diamine” represents a diamine in which an amino group is directly bonded to an aromatic ring, and an aliphatic group or other substituent may be included in a part of the structure. The aromatic ring may be a single ring or a condensed ring, and examples thereof include, but are not limited to, a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring. Among these, a benzene ring is preferable. The “aliphatic diamine” refers to a diamine in which an amino group is directly bonded to an aliphatic group, and an aromatic ring or other substituent may be included in a part of the structure.

  Examples of the aliphatic diamine include acyclic aliphatic diamines such as hexamethylene diamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, norbornane diamine, and 4,4 ′. -Cyclic aliphatic diamines such as diaminodicyclohexylmethane. These can be used alone or in combination of two or more.

  Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene and the like. Aromatic diamine having one aromatic ring, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′- Diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, bis [4- (4-aminophen Xyl) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-amino) Phenoxy) phenyl] propane, 2,2′-dimethylbenzidine, 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl (sometimes referred to as TFMB), 4,4′-bis ( 4-aminophenoxy) biphenyl, 9,9-bis (4-aminophenyl) fluorene, 9,9-bis (4-amino-3-methylphenyl) fluorene, 9,9-bis (4-amino-3-chlorophenyl) And aromatic diamines having two or more aromatic rings, such as fluorene and 9,9-bis (4-amino-3-fluorophenyl) fluorene. These can be used alone or in combination of two or more.

  The aromatic diamine is preferably 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, 3 , 3′-diaminodiphenylsulfone, 1,4-bis (4-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2 , 2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2′-dimethylbenzidine, 2,2′-bis ( Trifluoromethyl) -4,4′-diaminodiphenyl (TFMB), 4,4′-bis (4-amino) Phenoxy) biphenyl, more preferably 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, 1,4-bis (4 -Aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethylbenzidine, 2,2 ' -Bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB), 4,4'-bis (4-aminophenoxy) biphenyl. These can be used alone or in combination of two or more.

  Among the diamine compounds, from the viewpoint of high surface hardness, high transparency, high flexibility, high bending resistance and low colorability of the optical film, at least one selected from the group consisting of aromatic diamines having a biphenyl structure is used. It is preferable to use it. One selected from the group consisting of 2,2′-dimethylbenzidine, 2,2′-bis (trifluoromethyl) benzidine, 4,4′-bis (4-aminophenoxy) biphenyl and 4,4′-diaminodiphenyl ether It is more preferable to use the above, and it is even more preferable to use 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl (TFMB).

  Examples of the tetracarboxylic acid compound used for the production of the resin include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic dianhydrides; and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydrides. It is done. A tetracarboxylic acid compound may be used independently and may be used in combination of 2 or more type. The tetracarboxylic acid compound may be a dianhydride or a tetracarboxylic acid compound analog such as an acid chloride compound.

  Specific examples of the aromatic tetracarboxylic dianhydride include non-condensed polycyclic aromatic tetracarboxylic dianhydride, monocyclic aromatic tetracarboxylic dianhydride, and condensed polycyclic aromatic tetra Carboxylic dianhydrides are mentioned. Non-condensed polycyclic aromatic tetracarboxylic dianhydrides include, for example, 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-di Carboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (described as 6FDA) 1,2-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis ( 3,4-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2 , 3-dicarboxyphenyl) methane dianhydride, 4,4 ′-(p-phenylenedioxy) diphthalic dianhydride, 4,4 ′-(m-phenylenedioxy) diphthalic dianhydride. . In addition, examples of the monocyclic aromatic tetracarboxylic dianhydride include 1,2,4,5-benzenetetracarboxylic dianhydride, and condensed polycyclic aromatic tetracarboxylic dianhydride. Examples thereof include 2,3,6,7-naphthalenetetracarboxylic dianhydride.

  Among these, preferably 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride Anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyl Sulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2- Bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), 1,2-bis (2,3-dicarboxylate) Nyl) ethane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, 4,4 ′-( p-phenylenedioxy) diphthalic dianhydride and 4,4 ′-(m-phenylenedioxy) diphthalic dianhydride, more preferably 4,4′-oxydiphthalic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic dianhydride ( 6FDA , Bis (3,4-carboxyphenyl) methane dianhydride, and 4, 4 '- (p-phenylene-oxy) diphthalic acid dianhydride. These can be used alone or in combination of two or more.

  Examples of the aliphatic tetracarboxylic dianhydride include a cyclic or acyclic aliphatic tetracarboxylic dianhydride. The cycloaliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having an alicyclic hydrocarbon structure, and specific examples thereof include 1,2,4,5-cyclohexanetetracarboxylic dianhydride. 1, 2,3,4-cyclobutanetetracarboxylic dianhydride, cycloalkanetetracarboxylic dianhydride such as 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2.2 .2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl 3,3′-4,4′-tetracarboxylic dianhydride and their positional isomers. . These can be used alone or in combination of two or more. Specific examples of the acyclic aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and 1,2,3,4-pentanetetracarboxylic dianhydride. These may be used alone or in combination of two or more. Further, a cycloaliphatic tetracarboxylic dianhydride and an acyclic aliphatic tetracarboxylic dianhydride may be used in combination.

  Among the tetracarboxylic dianhydrides, 4,4′-oxydiphthalic dianhydride is used from the viewpoint of high surface hardness, high transparency, high flexibility, high bending resistance, and low colorability of the optical film, 3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 4,4 ′-(hexafluoroisopropylidene ) Diphthalic dianhydride and mixtures thereof are preferred, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 4,4 ′-(hexafluoroisopropylidene) diphthalic acid Objects, and more preferably mixtures thereof, 4,4 '- (hexafluoro isopropylidene) diphthalic anhydride (6FDA) is more preferred.

As the dicarboxylic acid compound used for the production of the resin, terephthalic acid, 4,4′-oxybisbenzoic acid, or an acid chloride compound thereof is preferably used. In addition to terephthalic acid, 4,4′-oxybisbenzoic acid or their acid chloride compounds, other dicarboxylic acid compounds may be used. Examples of other dicarboxylic acid compounds include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and related acid chloride compounds, acid anhydrides, and the like, and two or more kinds may be used in combination. Specific examples include diphthalic acid compounds of isophthalic acid; naphthalenedicarboxylic acid; 4,4′-biphenyldicarboxylic acid; 3,3′-biphenyldicarboxylic acid; chain hydrocarbons having 8 or less carbon atoms and two benzoic acids. Are a single bond, —CH ₂ —, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —SO ₂ — or a phenylene group, and acid chloride compounds thereof. As specific examples, 4,4′-oxybis (benzoyl chloride) and terephthaloyl chloride are preferable, and it is more preferable to use 4,4′-oxybis (benzoyl chloride) and terephthaloyl chloride in combination.

  The polyimide resin is obtained by further reacting tetracarboxylic acid and tricarboxylic acid, and anhydrides and derivatives thereof in addition to the tetracarboxylic acid compound as long as various physical properties of the optical laminate are not impaired. May be.

  Examples of the tetracarboxylic acid include anhydrous water adducts of the above tetracarboxylic acid compounds.

Examples of tricarboxylic acid compounds include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and related acid chloride compounds, acid anhydrides, and the like, and two or more kinds may be used in combination. Specific examples include 1,2,4-benzenetricarboxylic acid anhydride; 2,3,6-naphthalenetricarboxylic acid-2,3-anhydride; phthalic anhydride and benzoic acid are a single bond, -O- , —CH ₂ —, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —SO ₂ —, or a compound linked by a phenylene group.

  In the production of the resin, the amount of the diamine compound, tetracarboxylic acid compound and / or dicarboxylic acid compound used can be appropriately selected according to the desired ratio of each structural unit of the polyimide resin and polyamide resin.

  In the production of the resin, the reaction temperature of the diamine compound, tetracarboxylic acid compound, and dicarboxylic acid compound is not particularly limited, but is, for example, 5 to 350 ° C, preferably 20 to 200 ° C, and more preferably 25 to 100 ° C. Although reaction time is not specifically limited, For example, it is about 30 minutes-10 hours. If necessary, the reaction may be carried out under an inert atmosphere or under reduced pressure. In a preferred embodiment, the reaction is carried out with stirring under normal pressure and / or an inert gas atmosphere. The reaction is preferably performed in a solvent inert to the reaction. The solvent is not particularly limited as long as it does not affect the reaction. For example, water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, Alcohol solvents such as 2-butoxyethanol and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, γ-valerolactone, propylene glycol methyl ether acetate and ethyl lactate; Ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, methyl isobutyl ketone; pentane, hexane Aliphatic hydrocarbon solvents such as ethylcyclohexane; Aromatic hydrocarbon solvents such as toluene and xylene; Nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran and dimethoxyethane; Chloroform And chlorine-containing solvents such as chlorobenzene; amide solvents such as N, N-dimethylacetamide and N, N-dimethylformamide; sulfur-containing solvents such as dimethylsulfone, dimethylsulfoxide and sulfolane; carbonates such as ethylene carbonate and propylene carbonate Solvent; and combinations thereof (mixed solvent). Among these, amide solvents can be preferably used from the viewpoint of solubility.

  In the imidization step in the production of the polyimide resin, imidization can be performed in the presence of an imidization catalyst. Examples of the imidation catalyst include aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; N-ethylpiperidine, N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydro Alicyclic amines (monocyclic) such as azepine; azabicyclo [2.2.1] heptane, azabicyclo [3.2.1] octane, azabicyclo [2.2.2] octane, and azabicyclo [3.2. 2] Cycloaliphatic amines such as nonane (polycyclic); pyridine, 2-methylpyridine (2-picoline), 3-methylpyridine (3-picoline), 4-methylpyridine (4-picoline), 2- Ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2,4-dimethylpyridine, 2,4,6-trimethyl Pyridine, 3,4-cyclopentenopyridine pyridine, 5,6,7,8-tetrahydroisoquinoline, and aromatic amines isoquinoline. Moreover, it is preferable to use an acid anhydride with an imidation catalyst from a viewpoint which promotes an imidation reaction easily. Examples of acid anhydrides include conventional acid anhydrides used in imidization reactions, and specific examples thereof include aliphatic acid anhydrides such as acetic anhydride, propionic anhydride and butyric anhydride, and aromatics such as phthalic acid. An acid anhydride etc. are mentioned.

  Polyimide resins and polyamide resins are isolated (separated and purified) by conventional methods, for example, separation means such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, or a combination of these. In a preferred embodiment, the reaction solution containing a transparent polyamideimide resin can be isolated by adding a large amount of alcohol such as methanol to precipitate the resin, followed by concentration, filtration, drying and the like.

<Filler>
In the optical laminate of the present invention, the optical film may contain at least one filler. Examples of the filler include organic particles and inorganic particles, and preferably inorganic particles. Inorganic particles include silica, zirconia, alumina, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, cerium oxide and other metal oxide particles, magnesium fluoride, fluorine Among them, metal fluoride particles such as sodium fluoride are mentioned. Among these, from the viewpoint of improving the elastic modulus and / or tear strength of the obtained optical film and easily improving impact resistance, preferably silica particles, zirconia particles, An alumina particle is mentioned, More preferably, a silica particle is mentioned. These fillers can be used alone or in combination of two or more.

  In the optical layered body of the present invention, the optical film may contain at least one filler having an average primary particle diameter of, for example, 5 to 35 nm. Such optical films have high tensile properties as well as high optical properties. The tensile elastic modulus of the optical film is preferably 4,000 MPa or more, more preferably 5,000 MPa or more, further preferably 5,500 MPa or more, and particularly preferably 6,000 MPa or more. When the tensile elastic modulus is not less than the above lower limit, defects such as dents are less likely to occur in the optical film, the strength of the optical film is easily increased, and durability is easily improved. The tensile elastic modulus is preferably 10,000 MPa or less, more preferably 9,000 MPa or less. It is easy to improve the bending resistance of an optical film as a tensile elasticity modulus is below said upper limit. The tensile elastic modulus of the optical film can be measured using a tensile tester at room temperature in accordance with JIS K 7127. From the viewpoint of easily increasing the homogeneity, transparency, elastic modulus and strength of the optical film, the average primary particle diameter of the filler is preferably 10 nm or more, more preferably 15 nm or more, and further preferably 20 nm or more. Further, from the viewpoint of easily increasing the transparency of the optical film, the average primary particle diameter of the filler is preferably 30 nm or less.

The average primary particle diameter of the filler can be measured by the BET method. Specifically, the specific surface area (BET specific surface area) measured by the BET method (nitrogen adsorption BET method) can be calculated in terms of the average primary particle diameter. Here, when the average primary particle diameter is d (nm), the density of the filler is ρ (g / cm ³ ), and the BET specific surface area is S (m ² / g), d = 6000 / (S × ρ) holds. For example, when the filler is silica, the average primary particle diameter can be calculated from the BET specific surface area from the formula d = 2070 / S. In addition, you may measure a primary particle diameter (average primary particle diameter) by the image analysis of a transmission electron microscope (TEM) or a scanning electron microscope (SEM). The average primary particle diameter of the filler contained in the optical film may be the average primary particle diameter of the filler used as a raw material, or may be the average primary particle diameter measured from the optical film. When measuring the average primary particle diameter of the filler from the optical film, the average primary particle diameter of the filler in the optical film may be measured by image analysis of a transmission electron microscope or a scanning electron microscope using the film as a measurement sample. The film is pulverized as necessary, and the crushed film is dissolved in a solvent capable of dissolving the resin in the film (for example, γ-butyrolactone), and the dispersed particles are transferred to a transmission electron microscope (TEM) The average primary particle diameter may be calculated from the BET specific surface area in the same manner as described above by observing and measuring with a scanning electron microscope (SEM), or by removing the filler from the film and drying it. When measuring the average primary particle by, for example, image analysis using an electron microscope, an average value of the results of measuring the primary particle size for each of 100 particles existing within a certain area may be used as the average primary particle size.

  The content of the filler is preferably 0.5% by mass or more, more preferably 1% by mass or more, still more preferably 5% by mass or more, further preferably 10% by mass or more, and more preferably, with respect to the mass of the optical film. It is 15% by mass or more, more preferably 20% by mass or more, further preferably 25% by mass or more, and particularly preferably 30% by mass or more. It is easy to improve the impact resistance and durability of an optical film as content of a filler is more than said lower limit. The content of the filler is preferably 60% by mass or less, more preferably 50% by mass or less, and still more preferably 45% by mass or less with respect to the mass of the optical film. When the filler content is not more than the above upper limit, the haze and yellowness of the optical film can be easily reduced, transparency and optical characteristics can be easily improved, and flex resistance can be easily improved.

<Ultraviolet absorber>
The optical layered body of the present invention may contain at least one ultraviolet absorber. The ultraviolet absorber can be appropriately selected from those usually used as an ultraviolet absorber in the field of resin materials. The ultraviolet absorber may contain a compound that absorbs light having a wavelength of 400 nm or less. Examples of the ultraviolet absorber include at least one compound selected from the group consisting of benzophenone compounds, salicylate compounds, benzotriazole compounds, and triazine compounds. An ultraviolet absorber can be used individually or in combination of 2 or more types. Since the optical film contains the ultraviolet absorber, the deterioration of the resin is suppressed, and therefore the visibility can be enhanced when the optical film of the present invention is applied to an image display device or the like. In the present specification, the “system compound” refers to a derivative of the compound to which the “system compound” is attached. For example, a “benzophenone compound” refers to a compound having benzophenone as a host skeleton and a substituent bonded to benzophenone.

  In the optical layered body of the present invention, when the optical film contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.01 to 10 parts by mass with respect to the mass of the resin contained in the optical film. Preferably it is 1-8 mass parts, More preferably, it is 2-7 mass parts. When the content of the ultraviolet absorber is at least the above lower limit, the ultraviolet absorptivity is easily improved. When the content of the ultraviolet absorber is not more than the above upper limit, the decomposition of the ultraviolet absorber due to heat during the production of the substrate can be suppressed, and the optical characteristics can be easily improved, for example, haze can be easily reduced.

<Other additives>
The optical layered body of the present invention may further contain an additive other than the filler and the ultraviolet absorber. Examples of other additives include colorants such as antioxidants, mold release agents, stabilizers, and bluing agents, flame retardants, pH adjusters, silica dispersants, lubricants, thickeners, and leveling agents. Can be mentioned. When other additives are contained, the content thereof is preferably 0.005 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, and still more preferably 0.1 to 0.1 parts by mass with respect to the mass of the optical film. It may be 10 parts by mass.

<Functional layer>
The optical laminate of the present invention has an optical film and a functional layer laminated on at least one surface of the optical film. The function of the functional layer is not particularly limited, and includes a hard coat function, an antistatic function, an antiglare function, a low reflection function, an antireflection function, an antifouling function, a gas barrier function, a primer function, an electromagnetic wave shielding function, an undercoat function, and an ultraviolet ray. It may be a general function employed for an optical film, such as an absorption function, an adhesive function, and a hue adjustment function. The functional layer may be a layer having one type of function or a layer having two or more types of functions. From the viewpoint of easy use as a front plate of a flexible display device, at least one of the functional layers is selected from the group consisting of a hard coat function, an antistatic function, an antiglare function, a low reflection function, an antireflection function, and an antifouling function. It is preferable that the layer has at least one function. The functional layer may have a plurality of functions in one layer, or two or more layers having each function may be laminated. When two or more layers are laminated, the order of lamination is appropriately set according to the function. These layers are laminated on one side or both sides of the optical film. When laminated on both sides, the thickness, function, and order of lamination of the layers laminated on each surface may be the same or different.

  The thickness of the functional layer may be appropriately set according to the intended function, but is preferably 20 μm or less, more preferably 15 μm or less, from the viewpoint of easily reducing the weight and optical homogeneity of the optical laminate. More preferably, it is 10 μm or less.

(Hard coat function)
The hard coat function is a function of protecting the optical film by imparting scratch resistance, chemical resistance, and the like to the surface of the optical film. In the optical layered body of the present invention, the functional layer may be a layer having a hard coat function (hard coat layer). As the hard coat layer, a known one may be appropriately employed, and examples thereof include known hard coat layers such as acrylic, epoxy, urethane, benzyl chloride, and vinyl. Among these, from the viewpoint of suppressing a reduction in visibility in the wide-angle direction of the optical laminate and improving the flex resistance, a hard coat layer of an acrylic type, a urethane type, or a combination thereof is preferable. For example, the hard coat layer may be a cured product of a composition containing an active energy ray-curable compound. The active energy ray-curable compound is a compound having a property of being cured by irradiation with active energy rays such as an electron beam and ultraviolet rays. Examples of such an active energy ray-curable compound include an electron beam curable compound that is cured by irradiation with an electron beam, and an ultraviolet curable compound that is cured by irradiation with ultraviolet rays. These compounds are the same compounds as the main component of the hard coat agent used for forming a normal hard coat layer, and examples thereof include (meth) acrylic resins. In particular, among (meth) acrylic resins, those having a polyfunctional (meth) acrylate compound as a main component are preferable. In the present specification, (meth) acryl means acryl and / or methacryl, and (meth) acrylate means acrylate and / or methacrylate.

  The polyfunctional (meth) acrylate compound is a compound having at least two acryloyloxy groups and / or methacryloyloxy groups in the molecule, and specifically includes ethylene glycol di (meth) acrylate, diethylene glycol di (meth) ) Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate , Tetramethylolmethane tetra (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glyce N-tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris ((meth) acryloyloxyethyl) ) Isocyanurate, phosphazene acrylate compound or phosphazene methacrylate compound in which a (meth) acryloyloxy group is introduced into the phosphazene ring of the phosphazene compound, a polyisocyanate having at least two isocyanate groups in the molecule and at least one (meta ) Urethane (meth) acrylate compound obtained by reaction with a polyol compound having an acryloyloxy group and a hydroxyl group, at least two Such as polyester (meth) acrylate compounds obtained by reaction of boronic acid halides with polyol compounds having at least one (meth) acryloyloxy group and hydroxyl group, and dimers, trimers, etc. An oligomer etc. are mentioned.

  These compounds may be used alone or in combination of two or more. In addition to the polyfunctional (meth) acrylate compound described above, at least one monofunctional (meth) acrylate may be used. Examples of monofunctional (meth) acrylates include hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and 2-hydroxy-3-phenoxypropyl. (Meth) acrylate, glycidyl (meth) acrylate, etc. are mentioned. These compounds are used alone or in combination of two or more. The content of the monofunctional (meth) acrylate compound is preferably 10% by mass or less based on the solid content of the compound contained in the functional layer forming composition (hard coat layer coating material). In addition, in this specification, solid content means all the components except the solvent contained in a curable composition.

  For the purpose of adjusting the hardness, for example, a polymerizable oligomer may be added to the functional layer. Such oligomers include terminal (meth) acrylate polymethyl methacrylate, terminal styryl poly (meth) acrylate, terminal (meth) acrylate polystyrene, terminal (meth) acrylate polyethylene glycol, terminal (meth) acrylate acrylonitrile-styrene copolymer, Examples thereof include macromonomers such as terminal (meth) acrylate styrene-methyl (meth) acrylate copolymer. When adding a polymerizable oligomer, the content thereof is preferably 5 to 50% by mass with respect to the solid content of the composition for forming a functional layer.

  The active energy ray-curable compound may be used in the form of a solution mixed with a solvent. The active energy ray-curable compound and its solution may be commercially available as a hard coat agent. As a commercially available hard coat agent, specifically, “NK Hard M101” (manufactured by Shin-Nakamura Chemical Co., Ltd., urethane acrylate compound), “NK Ester A-TMM-3L” (manufactured by Shin-Nakamura Chemical Co., Ltd.) Tetramethylolmethane triacrylate), “NK Ester A-9530” (manufactured by Shin-Nakamura Chemical Co., Ltd., dipentaerythritol hexaacrylate), “KAYARAD® DPCA series” (manufactured by Nippon Kayaku Co., Ltd. Erythritol hexaacrylate compound derivative), "Aronix (registered trademark) M-8560" (manufactured by Toa Gosei Co., Ltd., polyester acrylate compound), "New Frontier (registered trademark) TEICA" (Daiichi Kogyo Seiyaku Co., Ltd.), Tris (acryloyloxyethyl) isocyanurate), "PPZ" (Kyoei) Chemical Co., Ltd., phosphazene methacrylate compound), and the like.

The thickness of the hard coat layer can be appropriately set, but is preferably 20 μm or less, more preferably 15 μm or less, and still more preferably 10 μm from the viewpoint of the flex resistance, surface hardness and optical homogeneity of the optical laminate. It is as follows.

  As a method of laminating the hard coat layer on at least one surface of the optical film, for example, a hard coat layer forming composition containing an active energy ray curable compound (active energy ray curable resin) is formed on the surface of the substrate (optical film). It only has to be applied and irradiated with active energy rays. Such a composition can be obtained by mixing the active energy ray-curable compound with an additive or the like, if necessary. A cured product of the composition for forming a hard coat layer constitutes a hard coat layer.

  The composition for forming a hard coat layer preferably contains a solvent, and in the composition for forming a hard coat layer, the active energy ray-curable compound is preferably diluted with a solvent. In this case, the composition is produced by mixing the active energy ray-curable compound and various additives (for example, silicone oil) for imparting surface smoothness, and then diluting the resulting mixture with a solvent. Alternatively, the active energy ray-curable compound may be diluted with a solvent and then mixed with an additive, or the active energy ray-curable compound may be mixed with an additive previously diluted with a solvent. The active energy ray-curable compound previously diluted with a solvent and the additive previously diluted with a solvent may be mixed and manufactured. The composition after mixing may be further stirred.

Also from the viewpoint of facilitating coating, the hard coat layer forming composition preferably contains an appropriate solvent. Solvents include aliphatic hydrocarbons such as hexane and octane, aromatic hydrocarbons such as toluene and xylene, alcohols such as ethanol, 1-propanol, isopropanol and 1-butanol, ketones such as methyl ethyl ketone and methyl isobutyl ketone, It can be appropriately selected from esters such as ethyl acetate and butyl acetate, cellosolves and the like. These organic solvents may be used in combination of several kinds as required. The boiling point of the solvent is preferably in the range of 70 ° C. to 200 ° C. from the viewpoint that the composition for forming a hard coat layer is heated after coating to easily evaporate the organic solvent. The type and amount of the solvent used are appropriately selected according to the type and amount of the active energy ray-curable compound to be used, the material (shape) of the base material (optical film), the coating method, the thickness of the desired hard coat layer, etc. Is done.
The temperature (T1) for heating and drying after coating the composition for forming a hard coat layer is preferably ± 30 ° C., more preferably ± with respect to the boiling point (T2) of the solvent contained in the composition. 20 ° C. When T1 is in the above range, the solvent is unlikely to remain in the hard coat layer from which the solvent is obtained, and the adhesion tends to be difficult to decrease.
The solid content of the composition for forming a hard coat is preferably 5 to 60% by mass, more preferably 10 to 55% by mass, still more preferably 20 to 50% by mass, and even more preferably 25 to 50% by mass. When the solid content is in the above range, the coating thickness is not too thick and the value of Formula 1 is not too large, so that the visibility is good and the smoothness of the surface of the obtained hard coat layer is good. Tend to be.

  The composition for forming a hard coat layer may contain a polymerization initiator. When ultraviolet rays or visible rays are used as active energy rays, a photopolymerization initiator is usually used as a polymerization initiator.

  Examples of the photopolymerization initiator include acetophenone, acetophenone benzyl ketal, anthraquinone, 1- (4-isopropylphenyl-2-hydroxy-2-methylpropan-1-one, carbazole, xanthone, 4-chlorobenzophenone, 4, 4'-diaminobenzophenone, 1,1-dimethoxydeoxybenzoin, 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone, 2,2-dimethoxy-2-phenylacetophenone, 1- (4-dodecylphenyl) -2- Hydroxy-2-methylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenyl Phosphine oxide, 1-hydroxysilane Rohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, benzaldehyde, benzoin ethyl ether, benzoisopropyl ether, benzophenone, Michler ketone, 3-methylacetophenone, 3,3 ′, 4,4′-tetra-tert-butylperoxycarbonylbenzophenone (BTTB), 2- (dimethylamino) -1- [4- (morpholinyl) phenyl] -2-phenylmethyl) -1-butanone, 4-benzoyl -4'-methyldiphenyl sulfide, benzyl and the like. The photopolymerization initiator may be used in combination with a dye sensitizer. Examples of the dye sensitizer include xanthene, thioxanthene, coumarin, and ketocoumarin. Examples of the combination of the photopolymerization initiator and the dye sensitizer include a combination of BTTB and xanthene, a combination of BTTB and thioxanthene, a combination of BTTB and coumarin, and a combination of BTTB and ketocoumarin.

  When using a photoinitiator, the usage-amount is preferably 0.1 mass part or more with respect to 100 mass parts of active energy ray-curable compounds. When the amount used is in the above range, a sufficient curing rate tends to be obtained. In addition, the usage-amount of a photoinitiator becomes like this. Preferably it is 10 mass parts or less per 100 mass parts of active energy ray hardening compounds.

  The composition for forming a hard coat layer may contain an antistatic agent in addition to the active energy ray-curable compound. When the composition contains an antistatic agent, an antistatic function can be imparted to the hard coat layer. Examples of the antistatic agent include surfactants, conductive polymers, conductive particles, alkali metal salts, and / or organic cation-anion salts. These antistatic agents are used alone or in combination of two or more.

  Examples of the surfactant include hydrocarbon surfactants, fluorine surfactants, silicone surfactants, and the like.

  Examples of the conductive polymer include polyaniline, polypyrrole, polyacetylene, and polythiophene.

  Examples of the conductive particles include particles of indium-tin-composite oxide (ITO), tin oxide doped with antimony, and the like.

  Alkali metal salts include organic and inorganic salts of alkali metals. Examples of the alkali metal ions constituting the cation part of the alkali metal salt include lithium, sodium, and potassium ions. Of these alkali metal ions, lithium ions are preferred.

The anion part of the alkali metal salt may be composed of an organic material or an inorganic material. Examples of the anion part constituting the organic salt include CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , and C ₄ F ₉ SO _{3. ^{-, C 3 F 7 COO -}} , (CF 3 SO 2) (CF 3 CO) N -, (FSO 2) 2 N -, - O 3 S (CF 2) 3 SO 3 -, CO 3 2-, wherein (A1) to formula (A4),
_{(A1) :( C n F 2n} + 1 SO 2) 2 N - (n represents an integer of 1 to 10),
_{(A2): CF 2 (C} m F 2m SO 2) 2 N - (m represents an integer of 1 to 10),
^{_{(A3): - O 3 S}} (CF 2) l SO 3 - (l represents an integer of 1 to 10),
^{_{(A4) :( C p F 2p}} + 1 SO 2) N - (C q F 2q + 1 SO 2), ( where, p and q are, independently of each other, represent an integer of 1 to 10),
An anion portion represented by In particular, an anion moiety containing a fluorine atom is preferably used because an ionic compound having good ion dissociation properties can be obtained. The anion part constituting the inorganic salt includes Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , AsF ₆ ⁻ , SbF. ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , (CN) ₂ N ^{− and the} like are used. Examples of the anionic ^{_{portion, (FSO 2) 2 N -}} , (CF 3 O 2) 2 N -, (C 2 F 5 SO 2) 2 N - are ^{_{preferred, (FSO 2) 2 N -}} , (CF 3 SO 2 ) ₂ N ^- is more preferable.

The organic cation-anion salt is an organic salt composed of a cation portion and an anion portion, and the cation portion is an organic substance. The anion part may be organic or inorganic. The “organic cation-anion salt” may be a substance called an ionic liquid or an ionic solid.
As the cation component, specifically, pyridinium cation, piperidinium cation, pyrrolidinium cation, cation having pyrroline skeleton, cation having pyrrole skeleton, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, Examples include pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, and tetraalkylphosphonium cation. As an anion component, the same thing as the anion part of the said alkali metal salt is mentioned. Among these, an anionic component containing a fluorine atom is preferably used because an ionic compound having good ion dissociation properties can be obtained.

  The composition for forming a hard coat layer is, for example, an organic compound containing a bromine atom, a fluorine atom, a sulfur atom, a benzene ring, or the like, for example, an inorganic oxide such as tin oxide, antimony oxide, titanium oxide, zirconium oxide, zinc oxide, or silicon oxide. Fine particles may be contained. In this case, the refractive index of the obtained hard coat layer can be adjusted, and optical functions such as a low reflection function and an antireflection function can be imparted to the hard coat layer.

  A composition containing an active energy ray-curable compound can be formed by applying a composition for forming a hard coat layer containing an active energy ray-curable compound on an optical film and then drying the composition. The coating can be performed by an ordinary method such as a micro gravure coating method, a roll coating method, a dipping coating method, a spin coating method, a die coating method, a cast transfer method, a flow coating method, or a spray coating method. From the viewpoint of easily improving the optical homogeneity of the optical laminate, it is preferable to laminate the hard coat layer forming composition by a micro gravure coating method or a die coating method.

Thereafter, the active energy ray-curable compound applied to the surface of the optical film is cured by irradiating the active energy ray, and the intended hard coat layer is obtained. Examples of the active energy rays include electron beams, ultraviolet rays, and visible rays, and are appropriately selected according to the type of active energy ray curable compound to be used. The active energy ray may be irradiated in the same manner as in the formation of a normal hard coat layer. The intensity | strength of the active energy ray to irradiate, irradiation time, etc. are suitably selected according to the kind of curable compound to be used, the thickness of the layer containing a curable compound, etc. The active energy ray may be irradiated in an inert gas atmosphere. In order to irradiate the active energy ray in a nitrogen atmosphere, for example, the active energy ray may be irradiated in a container sealed with an inert gas. As the inert gas, nitrogen gas, argon gas, or the like can be used.
It is also useful to further laminate an antireflection layer and a low reflection layer described later on the surface of the hard coat layer. In this case, the antireflection layer and the low reflection layer can be laminated on the surface of the hard coat layer as a single layer or as multiple layers.

(Antistatic function)
The antistatic function is a function for preventing the surface of the optical film from being charged. In the optical layered body of the present invention, the functional layer may be a layer having an antistatic function (antistatic layer). As a method for forming an antistatic layer, in addition to a method for adding an antistatic agent to the above hard coat layer forming composition to impart an antistatic function to the hardcoat layer, the antistatic agent is diluted with a solvent or the like. Examples thereof include a method in which the obtained antistatic layer forming composition is coated on an optical film or a functional layer laminated on the optical film, and dried as necessary to form a single film. The antistatic agent may be contained as a constituent unit having an antistatic function in a part of the resin constituting the functional layer (for example, the cured product of the active energy ray-curable compound described above), or the functional layer is formed. It may be added as an additive in the resin. When an antistatic agent is added as an additive, the addition amount is preferably 0.01 to 20% by mass, more preferably 0.05 to 10% by mass, based on the solid content of the functional layer forming composition. %, More preferably 0.1 to 10% by mass.

(Anti-glare function)
The antiglare function is a function that prevents reflection of external light by scattering and reflecting light. In the optical layered body of the present invention, the functional layer may be a layer having an antiglare function (antiglare layer). A well-known thing can be employ | adopted suitably as a glare-proof layer. For example, the antiglare function may be imparted by forming a layer having a fine uneven shape on the surface using a resin composition containing one or more kinds of light-transmitting fine particles in the light-transmitting resin. More specifically, for such an antiglare layer, for example, a translucent resin solution in which translucent fine particles as a filler are dispersed is applied on an optical film, and the translucent fine particles are formed on the antiglare layer. It can form by adjusting the thickness of application | coating so that it may become a convex-shaped part in the surface. Note that in this specification, “translucency” means that light can be transmitted almost regardless of the presence or absence of scattering inside the substance.

Translucent fine particles Examples of the translucent fine particles include organic fine particles such as (meth) acrylic resin, melamine resin, polyethylene resin, polystyrene resin, polycarbonate resin, vinyl chloride resin, organic silicone resin, and acrylic-styrene copolymer. And inorganic fine particles such as calcium carbonate, silica, aluminum oxide, barium carbonate, barium sulfate, titanium oxide, and glass. One kind or two or more kinds of fine particles can be used as the translucent fine particles. In order to obtain a desired antiglare property, the kind, particle diameter, refractive index, content and the like of the light-transmitting fine particles are appropriately adjusted.

  The particle size of the translucent fine particles is preferably 0.5 to 5 μm, more preferably 1 to 4 μm. When the particle diameter of the light-transmitting fine particles is within the above range, a necessary light diffusion effect can be easily obtained, and since unevenness is easily formed on the surface of the antiglare layer, a sufficient antiglare effect can be easily obtained. Furthermore, the surface shape of the antiglare layer is not rough and the haze value tends not to increase significantly.

  The difference in refractive index between the translucent fine particles and the translucent resin is preferably 0.02 to 0.2, more preferably 0.04 to 0.1. When the difference in refractive index is within the above range, it is easy to obtain a sufficient light diffusion effect, and the entire optical laminate is hardly whitened.

  The addition amount of the translucent fine particles is preferably 3 to 30 parts by mass, more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the translucent resin. When the addition amount is within the above range, it is easy to obtain a sufficient light diffusion effect, and the entire optical laminate is hardly whitened.

  When adjusting the particle size of the light-transmitting fine particles, the addition amount, and / or the refractive index difference between the light-transmitting fine particles and the light-transmitting resin in the above range, It is easy to prevent glare on the surface without lowering the transmission sharpness, and it is easy to prevent glare in a state where high transmission sharpness is maintained even in a low haze region.

Translucent resin The translucent resin constituting the antiglare layer is not particularly limited as long as it has translucency. For example, in addition to the cured product of the active energy ray-curable compound as described above, Examples include cured products of curable resins; thermoplastic resins; metal alkoxide polymers. Especially, the hardened | cured material of an active energy ray hardening compound is suitable. When an ultraviolet curable resin or the like is used as the active energy ray curable compound, a photopolymerization initiator (radical polymerization initiator) may be contained in the coating liquid as described above, and the active energy ray is irradiated. To cure the coating layer.

  Examples of the thermosetting resin include a thermosetting urethane resin composed of an acrylic polyol and an isocyanate prepolymer, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, and a silicone resin.

  Examples of the thermoplastic resin include cellulose derivatives such as acetylcellulose, nitrocellulose, acetylbutylcellulose, ethylcellulose, and methylcellulose; vinyl such as vinyl acetate and its copolymer, vinyl chloride and its copolymer, vinylidene chloride and its copolymer, etc. Acetal resins such as polyvinyl formal and polyvinyl butyral; (meth) acrylic resins such as acrylic resins and copolymers thereof, methacrylic resins and copolymers; polystyrene resins; polyamide resins; polyester resins; Examples include polycarbonate resins.

  As the metal alkoxide-based polymer, a silicon oxide-based matrix using a silicon alkoxide-based material as a raw material can be used. Specifically, the metal alkoxide polymer can be an inorganic or organic-inorganic composite matrix obtained by dehydration condensation of a hydrolyzate of alkoxysilane such as tetramethoxysilane or tetraethoxysilane.

  When a cured product of a thermosetting resin or a metal alkoxide polymer is used as the translucent resin, heating may be required after coating the coating liquid.

In general, the refractive index of the ultraviolet curable resin is about 1.5, which is about the same as that of glass. However, in comparison with the refractive index of the above-mentioned translucent fine particles, the refractive index of the ultraviolet curable resin to be used may be low. is there. In this case, TiO ₂ (refractive index; 2.3 to 2.7), Y ₂ O ₃ (refractive index; 1.87), La ₂ O ₃ (refractive), which are fine particles having a high refractive index, are added to the translucent resin. Permeability: 1.95), ZrO ₂ (refractive index: 2.05), Al ₂ O ₃ (refractive index: 1.63), etc. are added to the extent that light diffusibility can be maintained in the antiglare layer and transmitted. The refractive index of the conductive resin can be increased and adjusted to a preferable range.

  The composition for forming an antiglare layer can be produced by dispersing translucent fine particles in a composition containing a translucent resin and a solvent (for example, the above-described composition for forming a hard coat layer). There are no particular limitations on the timing and method of dispersing the translucent fine particles.

  The anti-glare layer can be formed by applying this anti-glare layer-forming composition (coating solution) to the surface of the optical film or the surface of the functional layer laminated on the optical film and drying it. The coating can be performed by a usual method such as a micro gravure coating method, a roll coating method, a dipping coating method, a spin coating method, a die coating method, a cast transfer method, a flow coating method, or a spray coating method. Thereafter, the ultraviolet curable resin may be cured by irradiating with ultraviolet rays. The intensity of ultraviolet rays to be irradiated, the irradiation time, and the like are appropriately selected according to the type of the curable compound used, the thickness of the layer containing the curable compound, and the like. Ultraviolet rays may be irradiated in an inert gas atmosphere. In order to irradiate ultraviolet rays in an inert gas atmosphere, for example, active energy ray irradiation may be performed in a container sealed with an inert gas, and nitrogen gas, argon gas, or the like can be used as the inert gas.

  As another method for forming the antiglare layer, embossing treatment can be used. In this method, an optical film or a functional layer laminated on the optical film is coated with a composition for forming an antiglare layer, and then a mold (embossing roll) having a predetermined surface irregularity shape is pressed on the coated layer. The coating layer can be cured as necessary while being applied to give irregularities to the surface of the coating layer. After peeling off the antiglare layer from the embossing roll, it is also effective to perform a second curing step of irradiating ultraviolet rays from the antiglare layer side again for the purpose of further promoting the curing reaction of the antiglare layer.

  The haze of the antiglare layer is preferably 0.1 to 50%. The haze of the antiglare layer is measured by a method according to JIS K 7361. The thickness of the antiglare layer may be appropriately adjusted so that, for example, the haze of the antiglare layer is within the above range, but is preferably 2 to 20 μm. When the thickness of the antiglare layer is within the above range, it is easy to obtain a sufficient antiglare effect, it is easy to prevent the antiglare layer from cracking, and the antiglare layer curls due to curing shrinkage of the antiglare layer It is easy to prevent a decrease in productivity. In general, the thickness of the antiglare layer is preferably 85% or more, more preferably 100% or more, with respect to the weight average particle diameter of the translucent fine particles to be dispersed. When the thickness of the antiglare layer is within the above range, the haze does not become too large and the visibility tends to be difficult to decrease.

  The antiglare layer may contain an antistatic agent. By containing an antistatic agent, an antiglare layer having an antistatic function can be obtained. Examples of the antistatic agent include the same antistatic agents as those added to the hard coat layer.

  The antiglare layer may have a low reflection layer on the outermost surface thereof, that is, the uneven surface side. Even if there is no low reflection layer, it exhibits a sufficient antiglare function, but the antiglare property can be further improved by providing a low reflection layer on the outermost surface. As the low reflection layer, those described later can be applied.

(Antireflection function and low reflection function)
The antireflection function and the low reflection function are functions for preventing or reducing reflection of external light. In the optical layered body of the present invention, the functional layer may be a layer having a function of preventing reflection of external light (antireflection layer), or a layer having a function of reducing reflection of external light (low reflection layer). There may be. The antireflection layer and the low reflection layer may be a single layer or a multilayer.

Antireflective layer The antireflective layer may comprise a low refractive index layer. The antireflection layer is a layer having a multilayer structure further comprising a low refractive index layer and a high refractive index layer and / or a middle refractive index layer laminated between the low refractive index layer and the optical film. Also good. The hard coat layer described above may be provided between the antireflection layer and the optical film.

  The thickness of the antireflection layer is preferably 0.01 to 1 μm, more preferably 0.02 to 0.5 μm. The antireflection layer is a low refractive index layer having a refractive index smaller than the refractive index of the optical film or functional layer on which the antireflection layer is laminated (for example, a refractive index of 1.3 to 1.45); made of an inorganic compound. Examples thereof include a layer in which a plurality of thin low refractive index layers and a thin high refractive index layer made of an inorganic compound are alternately stacked. Here, the refractive index of the high refractive index layer may be larger than the refractive index of the low refractive index layer, but is preferably 1.60 or more.

  The material for forming the low refractive index layer is not particularly limited as long as the material has a low refractive index. For example, a resin material such as an active energy ray curable resin (for example, an ultraviolet curable acrylic resin), a hybrid material in which inorganic fine particles such as colloidal silica are dispersed in the resin, or a sol-gel using a metal alkoxide such as tetraethoxysilane Materials and the like. The material for forming these low refractive index layers may be a polymerized polymer, or may be a monomer or oligomer serving as a precursor. Moreover, since the material which comprises an antireflection layer can provide an antifouling function to an antireflection layer, it is preferable that the compound containing a fluorine is included.

  The high refractive index layer is formed by applying a coating liquid containing a light-transmitting resin such as a cured product of the above-described active energy ray-curable resin or a metal alkoxide polymer, and inorganic fine particles and / or organic fine particles. It can form by the method of hardening a construction layer as needed. Examples of the inorganic fine particles include zinc oxide, titanium oxide, cerium oxide, aluminum oxide, silane oxide, tantalum oxide, yttrium oxide, ytterbium oxide, zirconium oxide, antimony oxide, and indium tin oxide (ITO). The high refractive index layer containing these inorganic fine particles can also have an antistatic function.

  As a method of manufacturing a multilayer film in which transparent thin films of inorganic compounds (metal oxides, etc.) having different refractive indexes are laminated, chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, metal compound sol such as metal alkoxide / Examples thereof include a method of forming a thin film by forming a colloidal metal oxide particle film by a gel method and then post-processing (ultraviolet irradiation: JP-A-9-157855, plasma treatment: JP-A-2002-327310).

  On the other hand, from the viewpoint of easily improving productivity, it is also preferable to laminate a thin film in which inorganic particles are dispersed in a matrix and laminate an antireflection layer. Furthermore, by applying a composition for forming an antireflective layer in which inorganic particles are dispersed in a matrix, when the antireflective layer is laminated, it is possible to prevent reflection by forming a fine uneven shape on the coated surface. It is also possible to further impart an antiglare function to the layer.

Low reflective layer The low reflective layer is a layer formed of a low refractive index material having a refractive index lower than that of the optical film serving as a substrate. The low refractive index layer is coated with a coating solution containing a light-transmitting resin such as a cured product of the above-described active energy ray-curable resin or a metal alkoxide polymer, and inorganic fine particles, and then the coating layer is used as necessary. And can be formed by a method of curing. As such a low refractive index material, specifically, lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), aluminum fluoride (AlF ₃ ), cryolite (3NaF · AlF ₃ or Na ₃ AlF ₆₎ ) And other inorganic low-reflective materials containing acrylic resin, epoxy resin, etc .; fluorine-based or silicone-based organic compounds, thermoplastic resins, thermosetting resins, UV-curable resins, etc. Organic low-reflection materials can be mentioned.

(Anti-fouling function)
The antifouling function is a function for preventing dirt, and is a function obtained by imparting water repellency, oil repellency, sweat resistance, antifouling property, fingerprint resistance and the like to the layer. In the optical layered body of the present invention, the functional layer may be a layer having an antifouling function (antifouling layer). The material for forming the antifouling layer may be an organic compound or an inorganic compound. Examples of materials that provide high water repellency and oil repellency include fluorine-containing organic compounds and organosilicon compounds. Examples of the fluorine-containing organic compound include fluorocarbon, perfluorosilane, and high molecular compounds thereof. From the viewpoint of easily increasing the effect of preventing the adhesion of dirt, a material that makes the contact angle of the antifouling layer surface with pure water 90 ° or more, more preferably 100 ° or more is preferable. As a method for forming the antifouling layer, a physical vapor deposition method, a chemical vapor deposition method, a wet coating method, or the like typified by vapor deposition or sputtering can be used depending on the material to be formed. The average thickness of the antifouling layer is usually about 1 to 50 nm, preferably 3 to 35 nm.

(UV absorption function)
In the optical layered body of the present invention, the functional layer may be an ultraviolet absorbing layer having an ultraviolet absorbing function. The ultraviolet absorption layer is composed of, for example, a main material selected from an ultraviolet curable translucent resin, an electron beam curable translucent resin, and a thermosetting translucent resin, and an ultraviolet absorption dispersed in the main material. It consists of an agent.

(Adhesion function)
In the optical layered body of the present invention, the functional layer may be an adhesive layer having an adhesive function for adhering the optical film to another member. As the material for forming the adhesive layer, a conventionally known material can be used. For example, a thermosetting resin composition or a photocurable resin composition can be used. In this case, the thermosetting resin composition or the photocurable resin composition can be polymerized and cured by supplying energy afterwards.

  The pressure-sensitive adhesive layer (Pressure Sensitive Adhesive, PSA), which is attached to an object by pressing, may be used as the pressure-sensitive adhesive layer. The pressure-sensitive adhesive may be a pressure-sensitive adhesive that is “a substance that is adhesive at room temperature and adheres to an adherend with light pressure” (JIS K 6800). ) And a capsule-type adhesive that can maintain stability until the coating is broken by appropriate means (pressure, heat, etc.) (JIS K 6800).

(Hue adjustment function)
In the optical layered body of the present invention, the functional layer may be a hue adjusting layer having a function capable of adjusting the optical layered body to a target hue. A hue adjustment layer is a layer containing resin and a coloring agent, for example. Examples of the colorant include inorganic pigments such as titanium oxide, zinc oxide, dial, titanium oxide-based fired pigment, ultramarine blue, cobalt aluminate, and carbon black; azo-based compounds, quinacridone-based compounds, anthraquinone-based compounds, and perylene. Organic pigments such as organic compounds, isoindolinone compounds, phthalocyanine compounds, quinophthalone compounds, selenium compounds, and diketopyrrolopyrrole compounds; body pigments such as barium sulfate and calcium carbonate; and basic dyes, acidic And dyes such as dyes and mordant dyes.

<Method for producing optical laminate>
Although the manufacturing method of the optical laminated body of this invention which has the said characteristic is not specifically limited, For example, the following process:
(A) a step of applying a polyimide resin and / or a polyamide resin, and a varnish containing at least a solvent on a support and drying to form a coating film;
(B) a step of peeling the coating film from the support;
(C) The peeled coating film can be heated to obtain a film, and (d) a production method comprising at least a step of laminating a functional layer on at least one surface of the film to obtain an optical laminate. The present invention also provides a method for producing an optical laminate including at least the above-described steps.

The method for producing an optical layered body of the present invention includes a step (c) or a step (d),
(E) Line profiles in a direction h and a direction v orthogonal to each other in a film inverse space image obtained by Fourier transforming a projection image obtained by a projection method using the obtained film or optical laminate, respectively. The line profile v is a line profile in the direction h ′ and the direction v ′ orthogonal to each other in a background inverse space image obtained by Fourier transforming a background image obtained without using the film or the optical laminate in the projection method. The line profile h ′ and the line profile v ′, respectively, the maximum intensity of the line profile (h ′ ′) obtained by subtracting the line profile h ′ from the line profile h is Y _mh, and the frequency indicating the maximum intensity Y _mh is X _mh , obtained by subtracting line profile v ′ from line profile v And the maximum intensity of the line profile (v-v ') and _{Y mv,} the frequency showing the maximum intensity _{Y mv} when the _{X mv, Y mh} and the value of _{Y mv, and, Y mh, Y mv, X} mh And evaluating the film based on a value of (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 calculated from X _mv .

を満たすことが好ましい。 The varnish used in the step (a) contains at least a polyimide resin and / or a polyamide resin and a solvent. Here, the viscosity (cps) of the varnish and the solid content concentration (mass%) of the varnish have the following relationship:

It is preferable to satisfy.

  First, the step (a) in which a varnish is applied on a support and dried to form a coating film will be described. Examples of the resin contained in the varnish include the resins described above as the resin contained in the optical film. Further, the varnish may contain the above-described ultraviolet absorber, filler, and other additives.

  The solvent contained in the varnish is not particularly limited as long as the resin can be dissolved. Examples of such solvents include amide solvents such as N, N-dimethylacetamide (DMAc) and N, N-dimethylformamide; lactone solvents such as γ-butyrolactone (GBL) and γ-valerolactone; dimethyl sulfone and dimethyl sulfoxide. And sulfur-containing solvents such as sulfolane; carbonate solvents such as ethylene carbonate and propylene carbonate; and combinations thereof (mixed solvents). Among these, an amide solvent or a lactone solvent is preferable from the viewpoint of easily improving the optical homogeneity of the optical layered body. These solvents can be used alone or in combination of two or more. The varnish may contain water, alcohol solvents, ketone solvents, acyclic ester solvents, ether solvents and the like. The solid content concentration of the varnish is preferably 1 to 25% by mass, more preferably 5 to 20% by mass.

  The varnish can be prepared by mixing and stirring the resin, the solvent, and the ultraviolet absorber, filler and other additives used as necessary. For example, a reaction liquid of a polyimide resin or a polyamide resin obtained by reacting the above dicarboxylic acid compound, tetracarboxylic acid compound, and / or diamine compound, and the above other raw materials may be used as a solvent and optionally other The varnish may be prepared by mixing with an additive and stirring. A varnish may be prepared by isolating a polyimide resin or a polyamide resin from a reaction solution and mixing with a solvent, etc., or a solution or solid of a polyimide resin or a polyamide resin may be purchased, if necessary The varnish may be prepared by mixing with a solvent or the like. Further, when silica is used as the filler, the varnish may be prepared using a silica sol in which a dispersion of silica sol containing silica is replaced with a solvent in which the resin can be dissolved, for example, a solvent used for preparing the following varnish. .

を満たすことが好ましい。ここで、ワニスの粘度（ｃｐｓ）は、ＪＩＳ Ｋ ８８０３：２０１１に従い、Ｅ型粘度計を用いて、２５℃で測定される。また、ワニスの固形分濃度は、ワニスに含有される樹脂、フィラー及び添加剤等の濃度（質量％）を表し、ワニスの全質量に基づくワニスに含有される固形分の質量から算出される。上記式で表されるワニスの粘度とワニスの固形分濃度との積は、光学積層体の光学的均質性を高めやすい観点から、好ましくは３，０００以上、より好ましくは３，５００以上である。上記式で表されるワニスの粘度とワニスの固形分濃度との積の上限は特に限定されないが、ワニスのハンドリングの観点からは、好ましくは１０，０００以下、より好ましくは７，０００以下である。 The viscosity (cps) of the varnish prepared as described above and the solid content concentration (mass%) of the varnish are not particularly limited. However, from the viewpoint of easily obtaining an optical laminate having excellent optical homogeneity, these are The following relationships:

It is preferable to satisfy. Here, the viscosity (cps) of the varnish is measured at 25 ° C. using an E-type viscometer according to JIS K 8803: 2011. Moreover, the solid content concentration of a varnish represents the density | concentration (mass%) of resin, a filler, an additive, etc. which are contained in a varnish, and is computed from the mass of the solid content contained in the varnish based on the total mass of a varnish. The product of the viscosity of the varnish represented by the above formula and the solid content concentration of the varnish is preferably 3,000 or more, more preferably 3,500 or more, from the viewpoint of easily improving the optical homogeneity of the optical laminate. . The upper limit of the product of the viscosity of the varnish represented by the above formula and the solid content concentration of the varnish is not particularly limited, but is preferably 10,000 or less, more preferably 7,000 or less from the viewpoint of varnish handling. .

  The viscosity of the varnish is preferably 5,000 to 60,000 cps, more preferably 10,000 to 50,000 cps, still more preferably 15,000 to 45,000 cps. When the viscosity of the varnish is not less than the above lower limit, the effect of the present invention can be easily obtained, and when it is not more than the above upper limit, handling of the varnish can be easily improved.

  The solid content concentration of the varnish is preferably 5 to 25% by mass, more preferably 10 to 23% by mass, and still more preferably 14 to 20% by mass. The solid content concentration of the varnish is preferably not less than the above lower limit from the viewpoint of obtaining a thick film, and is preferably not more than the above upper limit from the viewpoint of easy handling of the varnish.

  Examples of the support include a resin base material, a stainless steel belt, and a glass base material. It is preferable to use a resin film substrate as the support. Examples of the resin film substrate include a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, a cycloolefin-based (COP) film, an acrylic film, a polyimide film, and a polyamideimide film. Among these, PET films and COP films are preferable from the viewpoint of excellent smoothness and heat resistance, and PET films are more preferable from the viewpoint of adhesion to optical films and cost.

  The thickness of the support is not particularly limited, but is preferably 50 to 250 μm, more preferably 100 to 200 μm, and still more preferably 125 to 200 μm. When the thickness of the support is not more than the above upper limit, it is preferable because the production cost of the film can be easily suppressed. Moreover, it is preferable that the thickness of the support is equal to or more than the above lower limit because curling of the film that may occur in the step of removing at least a part of the solvent is easily suppressed. Here, the thickness of the support is measured by a contact-type film thickness meter or the like. From the viewpoint of easily improving the surface quality of the optical laminate and easy to produce the optical laminate of the present invention, the thickness distribution of the support is preferably ± 3 μm or less, more preferably ± 2.5 μm or less, and still more preferably. ± 2 μm or less. The thickness distribution of the support is calculated from the difference between the thickness at each location and the average thickness at each location by measuring the thickness at at least 20 locations on the film according to the thickness measurement method described above. To do.

  When applying a varnish on a support body, you may apply | coat to a support body by a well-known coating method. Known coating methods include, for example, roll coating methods such as wire bar coating, reverse coating, and gravure coating, die coating, comma coating, lip coating, spin coating, screen coating, fountain coating, dipping, Examples thereof include a spray method and a fluent molding method.

Next, a coating film can be formed by drying the coating film of the varnish apply | coated on the support body. Drying is performed by removing at least a part of the solvent from the coating film of the varnish, and the drying method is not particularly limited. For example, you may dry by heating the coating film of the varnish apply | coated on the support body. Hereinafter, the drying in the step (a) is also referred to as “first drying”, and the coating film formed on the support after drying is also referred to as “dry coating film”. The dried coating film may be a coating film in which all of the solvent contained in the varnish is dried, or may be a semi-dried coating film in which a part of the solvent is dried. The first drying may be performed under an inert atmosphere or under reduced pressure as necessary. The first drying is preferably performed at a relatively low temperature over time. When the first drying is performed at a relatively low temperature over time, the values of Y _mh and Y _mv in the above formula are easily lowered, and the value of (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 is set. It is easy to reduce, and it is easy to improve the optical homogeneity of an optical laminated body.

  In particular, when the optical laminate of the present invention is produced industrially, the actual production environment is often disadvantageous for improving optical homogeneity as compared with the production environment at the lab level. It may be difficult to increase the optical homogeneity of the. As described above, it is preferable to perform the first drying over time at a relatively low temperature. However, at the laboratory level, when the first drying is performed, the drying is performed in a sealed dryer. Therefore, the surface roughness of the optical laminate due to external factors is relatively unlikely to occur. On the other hand, when manufacturing an optical laminated body industrially, since it is necessary to heat a large area, for example in 1st drying, a ventilation apparatus may be used in the case of a heating. As a result, the surface state of the optical film tends to be rough, and it is difficult to improve the optical homogeneity of the film.

In the case of drying by heating, particularly considering the external factors as described above when industrially producing the optical laminate, the heating temperature at the first drying is preferably 60 to 150 ° C., more preferably It is 60-130 degreeC, More preferably, it is 70-120 degreeC. The first drying time is preferably 5 to 60 minutes, more preferably 10 to 40 minutes. The first drying may be carried out under one-stage or multi-stage conditions. However, in consideration of the above-described external factors particularly when the optical laminate is produced industrially, the first drying temperature is three or more stages. It is preferable to carry out under conditions. When drying is performed under multi-stage conditions, preferably, in each stage, drying can be performed under the same or different temperature conditions and / or drying time, for example, 3 to 10 stages, preferably 3 to 8 stages. Drying may be performed under the following conditions. When the first drying is performed under multistage conditions, it is easy to improve the optical homogeneity of the optical laminate. In a preferred embodiment of the present invention in which the first drying is performed under multi-stage conditions of three or more stages, it is preferable that the temperature profile of the first drying includes temperature increase and temperature decrease. That is, it is more preferable that the drying conditions in the step (a) are three or more heating temperature conditions in which the temperature profile includes temperature increase and temperature decrease. As an example of such a temperature profile, the temperature of the first drying is 70 to 90 ° C. (first temperature), 90 to 120 ° C. (second temperature), and 80 to 120 in this order. It is 80 degreeC (3rd temperature) and 80-100 degreeC (4th temperature). In this example, the temperature of the first drying is raised from the first temperature to the second temperature, then lowered from the second temperature to the third temperature, and further from the third temperature to the fourth temperature. Lower the temperature. Here, the first drying time is, for example, 5 to 15 minutes in each stage. It is preferable to carry out the first drying so that the solvent residual amount of the dry coating film is preferably 5 to 15% by mass, more preferably 6 to 12% by mass with respect to the mass of the dry coating film. When the solvent residual amount is in the above range, the values of Y _mh and Y _mv in the above formula of the optical film or the optical laminate are easily lowered, and (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 It is easy to lower the value. In the subsequent step (b), it is easy to improve the peelability when the coating film is peeled off from the support. As a result, it is easy to improve the optical homogeneity of the optical laminate. The residual amount of the solvent decreases by increasing the drying temperature in each step and increasing the drying time. Therefore, the optical homogeneity of the optical laminate can be improved by adjusting the drying temperature and the drying time so that the solvent residual amount is in a desired range.

  Next, in the step (b), the dried coating film is peeled off from the support. The peeling method is not particularly limited, and the coating may be moved while the support is fixed, and the peeling may be performed, or the support may be moved while the coating is fixed, and the peeling may be performed. Then, peeling may be performed by moving both the coating film and the support.

Next, in the step (c), an optical film can be obtained by heating the coating film peeled in the step (b). Hereinafter, the heating step in the step (c) is also referred to as “second drying” or “post-bake”, and the coating film peeled in the step (b) is also referred to as “peeling coating film”. In the step (c), it is preferable to carry out post-baking in a state where the release coating film is stretched in the in-plane direction. The heating temperature in the second drying is preferably 150 to 300 ° C, more preferably 180 to 250 ° C, and still more preferably 180 to 230 ° C. The heating time in the second drying is preferably 10 to 60 minutes, more preferably 30 to 50 minutes. When the post-baking treatment is carried out in a state where the dried coating film is uniformly stretched in the in-plane direction, the values of Y _mh and Y _mv in the above formula of the optical film or optical laminate can be easily reduced, and (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 value is likely to be lowered.

When heating the coating film in the step (3), it is preferable to heat the coating film in a state where tension is applied to the coating film and the coating film is stretched in the in-plane direction. By heating while applying tension, it is easy to suppress a decrease in the optical homogeneity of the film caused by shrinkage of the coating film due to drying. As a result, Y _mh and Y _mv in the above formula of the optical film or optical laminate The value is easy to decrease, the value of (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 is easy to decrease, and the optical homogeneity is easy to increase.

  In one embodiment of the present invention, when an optical film is produced by a roll-to-roll method, the release coating film may be dried in a state of being extended in the transport direction. Moreover, when manufacturing an optical film by a single wafer type, you may dry in the state extended | stretched uniformly in the in-plane direction. The conveyance speed in the roll-to-roll method is preferably from 0.1 to 10 m / min, more preferably from 0.5 to 8 m / min, and even more preferably from the viewpoint of easily improving the optical homogeneity of the optical laminate. 5 to 5 m / min.

  For example, when manufacturing an optical film by a roll-to-roll system, an optical film can be obtained by heating while conveying a long strip-shaped coating film having a predetermined width. Here, when heating is performed while applying tension to the coating film, the method is not limited at all, but for example, gripping both ends of a long belt-shaped film to be transported and transporting the gripped film The heat treatment is performed while the inside of the dryer is transported, for example, with the width of the formed film as a predetermined distance. At this time, the ratio of the film width after heat treatment (but not including the grip portion in the width) to the width of the film before heat treatment (however, the grip portion is not included in the width) is 1.1 or less, and It is preferable to perform the step (3) by releasing the grip of the resin film that has come out of the dryer.

  The ratio of the film width after heat treatment (but not including the grip portion in the width) to the width of the film before heat treatment (however, the grip portion is not included in the width) (hereinafter, sometimes referred to as the draw ratio) is preferably Is 0.70 to 1.10, more preferably 0.80 to 1.05, and still more preferably 0.85 to 1.03.

The film is gripped by using a plurality of clips, for example.
The plurality of clips can be fixed to an endless chain of a predetermined length depending on the size of the conveying device, the chain moves at the same speed as the film, and the clip is positioned at an appropriate position of the chain. The transparent resin film is gripped before entering the dryer, and the grip is released when the dryer exits.

  The plurality of clips installed at one end of the film are installed so that the space between the adjacent clips is, for example, 1 to 50 mm, preferably 3 to 25 mm, more preferably 5 to 10 mm.

  In addition, when a straight line perpendicular to the film transport axis is aligned with the center of the grip of an arbitrary clip at one end of the film, the intersection of the straight line and the other end of the film and the center of the grip of the clip closest to the intersection Is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1 mm or less. When the distance is in the above range, it is easy to improve the homogeneity of the film particularly on the left and right.

  When the ratio of the width of the film after heat treatment to the width of the film before heat treatment is in the above range, the film appearance tends to be good.

The amount of solvent in the film after the heat treatment is preferably 0.001 to 3% by mass, more preferably 0.001 to 2% by mass, and still more preferably 0.001 to 1.5% by mass, based on the mass of the film. Particularly preferred is 0.001 to 1.3% by mass. When the amount of solvent in the film after the heat treatment is in the above range, the appearance of the optical film tends to be good.
When the heat treatment is finished and the film comes out of the dryer, the film is released from gripping and is preferably slit immediately at the end of the film. By removing the cracks that are likely to occur between the gripping part and the part that was not gripped at the film end by performing slits, the film is then transported and its temperature decreases. The spread of cracks can be prevented in advance.

As the film exits the dryer, the film may be quenched and contracted, causing cracking. Therefore, it is preferable that there is a step of relaxing a certain percentage of the film from the dryer outlet to the position where the grip of the film is released. The ratio is preferably the width of the film coming out of the dryer (excluding the gripped width) (W) and the distance (F) by which the gripping part is relaxed before the film is released from the outlet of the dryer. 1.7 ≦ F / W × 100 ≦ 6.9, more preferably 1.8 ≦ F / W × 100 ≦ 6.8, more preferably 1.9 ≦ F / W × 100 ≦ 6.7, More preferably, 2.0 ≦ F / W × 100 ≦ 6.7.
The relaxed distance on one end side with respect to the film transport direction is Fa, the relaxed distance on the other end side is Fb, and the combined distance is the relaxed distance F.
The distance from the outlet of the dryer until the grip of the film is released is preferably 200 to 2,000 mm, more preferably 300 to 1,500 mm, still more preferably 300 to 1,300 mm, and even more preferably 300 to 1, 000 mm. When the distance is in the above range, the film is less likely to be cracked and appearance defects such as dripping tend to hardly occur.

In the production method of the present invention, from the viewpoint of easy production of the optical laminate having the above characteristics, after peeling the coating film from the support in the step (b), the coating film peeled in the step (c) is heated. By doing so, the film is manufactured. However, the optical laminate of the present invention may be a film produced by any production method as long as the optical film or the optical laminate has characteristics relating to the above-mentioned Y _{mh and the} like. For example, the film may be manufactured by post-baking the coating film before peeling the coating film from the support and peeling the post-baked film from the support.

  Next, in the step (d), a functional layer is laminated on at least one surface of the film to obtain the optical laminate of the present invention. As a method of laminating a functional layer on at least one side of the film, a method of coating a functional layer forming composition on at least one side of the film, and drying and / or curing as necessary, and laminating, at least the film The method of laminating | stacking a film-like functional layer on one side is mentioned. From the viewpoint of easily improving the optical homogeneity of the optical laminate, it is preferable to apply the functional layer forming composition and laminate the functional layers.

The production method of the present invention may further include a step (e) of evaluating a film or an optical laminate described later after the step (c) or after the step (d). In step (e), line profiles in the direction h and the direction v that are orthogonal to each other in the film inverse space image obtained by Fourier transforming the projection image obtained by the projection method using the obtained film or optical laminate are respectively shown. In the direction h ′ and the direction v ′ orthogonal to each other in the background inverse space image obtained by performing Fourier transform on the background image obtained without using the film or the optical laminate in the projection method, with the profile h and the line profile v. The line profiles are the line profile h ′ and the line profile v ′, respectively, the maximum intensity of the line profile (h ′ ′) obtained by subtracting the line profile h ′ from the line profile h is Y _mh , and the maximum intensity Y _mh is indicated. The frequency is X _mh, and the line profile v ′ is changed from the line profile v. Subtracting the maximum intensity of obtained line profile (v-v ') and _{Y mv,} the frequency showing the maximum intensity _{Y mv} when the _{X mv,} the value of _{Y mh} and _{Y mv, and, Y mh,} Y _mv , X _mh and X _mv calculated from the value of (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 .

In step (e), the optical homogeneity of the film or the optical laminate is evaluated based on the values of Y _mh and Y _{mv and} the value of (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2. be able to. For example, by setting a predetermined value according to the desired optical homogeneity and comparing the value with the result obtained for the film or optical laminate, the quality of the film is judged and the film is separated. , Y _mh and Y _mv , and (Y _mh + Y _mv ) / (X _mh + X _mv ) ^1/2 are equal to or less than a predetermined value, and an optical film or optical laminate having excellent optical homogeneity The body can be manufactured. Moreover, drying conditions etc. can be adjusted, evaluating the said value, and the optical laminated body of this invention which has the said characteristic can also be manufactured.

In the step (e) for evaluating the film, the optical homogeneity is evaluated based on the maximum strengths Y _mh and Y _mv measured by the evaluation method of the present invention, and the quality of the optical film or the optical laminate is determined. It is preferable to judge from the viewpoint that an optical laminate excellent in optical homogeneity can be efficiently produced. The criteria for determining the quality of the optical film or optical laminate may be appropriately set according to the use of the optical laminate finally obtained and the optical homogeneity required for the optical laminate, and are not particularly limited. For the purpose of obtaining an optical laminate having excellent homogeneity that is suitably used as an optical film or the like, the optical laminate of the present invention may be used when judging the quality of the optical film or optical laminate. It is preferable to judge whether the optical film included or the optical laminate of the present invention has the characteristics described above based on whether or not it has the characteristics described above.

According to the evaluation process, it is possible to evaluate the optical homogeneity with higher accuracy than the conventional evaluation method. Specifically, according to the evaluation process, an optical caused by unevenness in both the TD direction and the MD direction, or unevenness in width, which could not be evaluated with sufficient accuracy by the conventional evaluation method, It is possible to evaluate variations in the physical properties, and it is possible to accurately evaluate the optical homogeneity regardless of the type of unevenness. Moreover, it is also possible to quantify the homogeneity of the film or the optical laminate by the evaluation step. In addition, in this specification, the optical film or optical laminated body made into a measuring object at an evaluation process is also called "measurement film." Specifically, the evaluation step in the step (e) includes the following steps (1) to (5):
(1) A step of irradiating a measurement film with light from a light source and obtaining a projection image by a projection method in which light transmitted through the measurement film is projected onto a projection plane;
(2) A step of projecting light from a light source onto a projection surface without using a measurement film in the projection method of step (1) to obtain a background image;
(3) The projection image obtained in step (1) and the background image obtained in step (2) are each digitized by gray scale conversion, and the digitized image data is Fourier transformed to produce an inverse aerial image (film inverse aerial image). And a background inverse aerial image),
(4) A step of obtaining a blank-corrected line profile by subtracting the line profiles in the two directions orthogonal to each other in the inverse space image of the background image from the line profiles in two directions orthogonal to the inverse space image of the projection image. ,
as well as,
(5) At least the step of measuring the maximum intensity (Y _mh and Y _mv ) of the blank-corrected line profile obtained in step (4).

  In step (1), the measurement film is irradiated with light from the light source, and the light transmitted through the measurement film is projected onto the projection surface to obtain a projection image. In step (1), for example, as shown in FIG. 1, a measurement film, a projection surface, and the like may be arranged. Specifically, the light source 1, the measurement film 2, and the projection surface 3 are arranged, and the projection image 4 projected on the projection surface 3 is photographed by the camera 6 to obtain a projection image. The light 5 output from the light source 1 passes through the measurement film 2, and the transmitted light is projected on the projection surface 3 as a projection image 4. If the measurement film 2 is homogeneous when the light 5 is transmitted through the measurement film 2, the light 5 is uniformly transmitted through the measurement film 2 and reaches the projection surface 3. However, the measurement film 2 is not homogeneous, and the surface unevenness, When there is unevenness in thickness, orientation unevenness, etc., light 5 is reflected and / or refracted when it passes through the measurement film 2, and light distorted compared to the state output from the light source is projected. Reach plane 3. By evaluating the projection image 4 thus obtained by the method described later, the optical homogeneity of the measurement film can be evaluated or quantified with high accuracy. From the viewpoint of easily obtaining a clear projected image, it is preferable to take a picture in the dark room by transmitting only the light from the light source through the measurement film. The type of the light source is not particularly limited, and for example, an LED light source or a halogen lamp may be used. A light source close to a point light source is preferable, and the light emitting part preferably has a diameter of 1 cm or less. Since the projected image tends to become unclear when passing through a filter or lens, light that does not pass through the filter or lens is preferable. The projection surface is not particularly limited as long as the projected image of the measurement film is visually recognized. For example, an acrylic plate, a vinyl chloride plate, a polyethylene plate, a movie screen, or the like may be used. The method for capturing the image projected on the projection plane is not particularly limited. For example, as shown in FIG. 1, the projection plane 3, the measurement film 2, and the light source 1 are arranged on a straight line and projected onto the projection plane 3. The camera 6 may be fixed and photographed at a position where the projection image 4 is photographed obliquely. The shooting mode may be set as appropriate, for example, a setting as described in the embodiments may be used. In this way, a projection image is obtained.

  In step (2), light from the light source is projected onto the projection surface without using a measurement film in the projection method of step (1) to obtain a projection image. Specifically, for example, in FIG. 1, shooting is performed with only the measurement film 2 removed, and a background image is obtained.

  In step (3), the projection image obtained in step (1) and the background image obtained in step (2) are each digitized by gray scale, and the digitized image data is Fourier transformed to obtain an inverse space image. . Gray scale conversion can be performed by, for example, 8-bit gray scale conversion using image analysis software (for example, “Image-J” manufactured by National Institutes of Health, USA). The projection image and the background image can be digitized by the gray scale conversion. Next, the digitized image data is Fourier transformed to obtain inverse aerial images (film inverse aerial image and background inverse aerial image). By performing a Fourier transform on the digitized image data, it is possible to obtain the period and amplitude of the light and shade of the image. Examples of the Fourier transform method include using the Fourier transform function of image analysis software (Image-J).

  In step (4), the line profiles in the two directions orthogonal to each other in the inverse aerial image of the projection image are subtracted from the line profiles in the two directions orthogonal to each other in the inverse aerial image of the background image. Get.

In step (5), the maximum intensity Y _max (Y _mh and Y _mv , respectively) of the blank-corrected line profile obtained in step (4) is measured. The measurement method of Y _mh and Y _mv is as described above for the measurement film. For example, the line profile for each of the horizontal direction (h1 direction) and the vertical direction (v1 direction) passing through the center of the inverse aerial image. Is generated, for example, as a graph representing frequency on the X axis and intensity on the Y axis, as shown in FIG. Then, the maximum intensity Y _max in the horizontal (h1 direction) line profile is set to Y _mh1, and a value obtained by subtracting the median value X _cen of all frequencies in the blank-corrected line profile from the frequency indicating the maximum intensity Y _mh1 Let _max be _Xmh1 . Further, the maximum intensity Y _max in the line profile in the vertical direction (v1 direction) is set to Y _mv1, and a value obtained by subtracting the median value X _cen of all frequencies in the blank-corrected line profile from the frequency indicating the maximum intensity Y _mv1 Let _max be X _mv1 . The two directions are not particularly limited as long as they are orthogonal to each other, and may be two directions that do not pass through the center, or may not be the horizontal direction and the vertical direction.

By measuring the above Y _mh and Y _mv , the homogeneity can be evaluated in the two-dimensional direction of the measurement film. The planar unevenness that contributes to reducing the optical homogeneity of the measurement film includes a kind of unevenness that cannot be sufficiently detected by one-dimensional evaluation, such as striped unevenness. According to the evaluation method of the present invention, optical homogeneity can be evaluated in a two-dimensional direction, so that evaluation can be performed with high accuracy regardless of the type of unevenness of the measurement film. Moreover, it is also possible to quantify the homogeneity of the measurement film by measuring Y _mh and Y _mv and obtaining values.

Furthermore, in addition to the maximum intensities Y _mh and Y _mv , X _mh and X _mv which are values obtained by subtracting the median value X _cen of all frequencies in the line profile subjected to blank correction from the frequencies indicating these maximum intensities are used. By performing the evaluation, it is also possible to detect a cycle in which planar unevenness that contributes to the optical homogeneity of the measurement film occurs.

  The optical laminate of the present invention may be a film roll wound around a core. The material constituting the core is not particularly limited, but for example, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyester resin, epoxy resin, phenol resin, melamine resin, silicon resin, polyurethane resin, polycarbonate resin, ABS resin, etc. It may be a synthetic resin; a metal such as aluminum; a fiber reinforced plastic (FRP: a composite material in which fibers such as glass fiber are contained in the plastic to improve the strength). The shape of the core is not particularly limited, but is preferably a cylindrical or columnar shape. When the winding core is cylindrical or columnar, the outer diameter is preferably 1 to 12 inches, more preferably 3 to 10 inches, and further preferably 3 to 6 inches from the viewpoint of strength and operability. . Moreover, the vertical length of the core is preferably 1.0 to 2.0 times, more preferably 1.0 to 1.times the length in the width direction of the transparent resin film to be wound from the viewpoint of operability. 8 times, more preferably 1.0 to 1.5 times.

  When the optical laminate of the present invention is in the form of a film roll, in the production process of the optical laminate, the optical laminate having the optical film and the functional layer, and optionally a protective film, is wound around the core in a roll shape. It may have a different form. The optical film may not be peeled from the support, and the support may be wound together. The optical laminate of the present invention may be an optical laminate in the form of a film roll or a film obtained by cutting an optical laminate in the form of a film roll.

  The optical laminate of the present invention preferably has a length in the width direction of 20 cm or more, more preferably 30 cm or more, still more preferably 40 cm or more, even more preferably 50 cm or more, particularly preferably from the viewpoint of easily improving optical homogeneity. Is 60 cm or more. Although the upper limit of the length of the width direction is not specifically limited, For example, it may be about 200 cm or less. In the optical laminate of the present invention, the length in the length direction is preferably 1 m or more, more preferably 10 m or more, still more preferably 100 m or more, and even more preferably 200 m or more, from the viewpoint of easily improving optical homogeneity. Even more preferably, it is 300 m or more, particularly preferably 400 m or more. The upper limit of the length in the length direction is not particularly limited, and may be, for example, about 5000 m or less. By laminating at least one functional layer on the optical film having the above size, an optical layered body having the above size can be manufactured. The optical laminate having the above-mentioned size is preferably produced by a roll-to-roll method from the viewpoint of easily improving optical homogeneity, that is, preferably in the form of a film roll. From the obtained film roll, the optical laminate can be cut out and used according to the size of the required flexible device.

If the size of the optical stack or optical film, for example, as described above large, cut a film having a predetermined size (e.g., 200 mm × 300 mm) as a measurement film, a Y _mh such determined for the measurement film The value may be evaluated. You may measure about several sheets and may evaluate using the average value of the obtained value. A preferable range of the average value is the same as the above-described range regarding Y _mh and the like.

<Protective film>
A protective film may be laminated on the optical laminate of the present invention. The protective film may be laminated on one side or both sides of the optical laminate. When the optical laminate has a functional layer on one side and no functional layer on the other side, the protective film may be laminated on the functional layer side surface of the optical laminate, It may be laminated on the surface on the film side, or may be laminated on both surfaces. When the optical laminate has functional layers on both sides, the protective film may be laminated on the surface on one functional layer side, or may be laminated on the surfaces on both functional layer sides. The protective film is a film for temporarily protecting the surface of the optical film or the functional layer, and is not particularly limited as long as it is a peelable film that can protect the surface of the optical film or the functional layer. Examples of the protective film include polyester resin films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resin films such as polyethylene and polypropylene films, acrylic resin films, and the like. It is preferably selected from the group consisting of a terephthalate resin film and an acrylic resin film. When two protective films are laminated | stacked on the optical laminated body of this invention, each protective film may be the same or different.

  Although the thickness of a protective film is not specifically limited, Usually, 10-120 micrometers, Preferably it is 15-110 micrometers, More preferably, it is 20-100 micrometers. When two protective films are laminated | stacked on the optical laminated body of this invention, the thickness of each protective film may be the same and may differ.

<Flexible display device>
The present invention also provides a flexible display device comprising the optical laminate of the present invention. The optical laminate of the present invention is preferably used as a front plate in a flexible display device, and the front plate may be referred to as a window film. The flexible display device includes a flexible display device laminate and an organic EL display panel. The flexible display device laminate is arranged on the viewing side with respect to the organic EL display panel, and is configured to be bendable. The laminate for a flexible display device may further contain a polarizing plate (preferably a circularly polarizing plate), a touch sensor, and the like, and the order of stacking is arbitrary, but the window film, polarizing plate, touch from the viewing side. The layers are preferably laminated in the order of sensors, or in the order of window film, touch sensor, and polarizing plate. It is preferable that the polarizing plate is present on the viewing side of the touch sensor because the touch sensor pattern is less visible and the visibility of the display image is improved. Each member can be laminated | stacked using an adhesive agent, an adhesive, etc. The flexible display device may include a light shielding pattern formed on at least one surface of any one of the window film, the polarizing plate, and the touch sensor.

<Circularly polarizing plate>
As described above, the flexible display device of the present invention preferably includes a polarizing plate, particularly a circularly polarizing plate. The circularly polarizing plate is a functional layer having a function of transmitting only the right or left circularly polarized component by laminating a λ / 4 retardation plate on a linearly polarizing plate. For example, external light is converted into right circularly polarized light, the external light reflected by the organic EL panel and turned into left circularly polarized light is blocked, and only the light emitting component of the organic EL is transmitted to suppress the influence of the reflected light and image Used to make it easier to see. In order to achieve the circular polarization function, the absorption axis of the linearly polarizing plate and the slow axis of the λ / 4 retardation plate need to be 45 degrees theoretically, but practically 45 ± 10 degrees. The linearly polarizing plate and the λ / 4 retardation plate are not necessarily laminated adjacent to each other, as long as the relationship between the absorption axis and the slow axis satisfies the above range. Although it is preferable to achieve complete circular polarization at all wavelengths, the circular polarization plate in the present invention includes an elliptical polarization plate because it is not always necessary in practice. It is also preferable to further improve the visibility in a state where polarized sunglasses are applied by laminating a λ / 4 retardation film on the viewing side of the linearly polarizing plate and making the emitted light circularly polarized.

  The linear polarizing plate is a functional layer having a function of blocking polarized light having a vibration component perpendicular to the light that is oscillating in the transmission axis direction. The linear polarizing plate may have a configuration including a linear polarizer alone or a linear polarizer and a protective film attached to at least one surface thereof. The linear polarizing plate may have a thickness of 200 μm or less, preferably 0.5 to 100 μm. When the thickness of the linearly polarizing plate is in the above range, the flexibility of the linearly polarizing plate tends to be difficult to decrease.

The linear polarizer may be a film-type polarizer manufactured by dyeing and stretching a polyvinyl alcohol (hereinafter abbreviated as PVA) film. A dichroic dye such as iodine is adsorbed on a PVA-based film oriented by stretching or is stretched in a state of being adsorbed to PVA, whereby the dichroic dye is oriented and exhibits polarizing performance. In the production of the film-type polarizer, other processes such as swelling, crosslinking with boric acid, washing with an aqueous solution, and drying may be included. The stretching or dyeing process may be performed by a PVA film alone or in a state where it is laminated with another film such as polyethylene terephthalate. The thickness of the PVA film used is preferably 10 to 100 μm, and the draw ratio is preferably 2 to 10 times.
Furthermore, as another example of the polarizer, there is a liquid crystal coating type polarizer formed by coating a liquid crystal polarizing composition. The liquid crystal polarizing composition may include a liquid crystal compound and a dichroic dye compound. The liquid crystalline compound only needs to have the property of exhibiting a liquid crystal state. In particular, the liquid crystalline compound preferably has a higher-order alignment state such as a smectic phase because it can exhibit high polarization performance. The liquid crystalline compound preferably has a polymerizable functional group.
The dichroic dye compound is a dye that is aligned with the liquid crystal compound and exhibits dichroism, and may have a polymerizable functional group, and the dichroic dye itself has liquid crystallinity. It may be.
Any of the compounds contained in the liquid crystal polarizing composition has a polymerizable functional group. The liquid crystal polarizing composition may further contain an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like.
The liquid crystal polarizing layer is manufactured by applying a liquid crystal polarizing composition on an alignment film to form a liquid crystal polarizing layer. The liquid crystal polarizing layer can be formed thinner than a film-type polarizer, and the thickness is preferably 0.5 to 10 μm, more preferably 1 to 5 μm.

The alignment film is produced, for example, by applying an alignment film forming composition on a substrate and imparting alignment by rubbing, polarized light irradiation, or the like. The alignment film forming composition contains an alignment agent, and may further contain a solvent, a crosslinking agent, an initiator, a dispersant, a leveling agent, a silane coupling agent, and the like. Examples of the aligning agent include polyvinyl alcohols, polyacrylates, polyamic acids, and polyimides. When using an aligning agent that imparts orientation by polarized light irradiation, it is preferable to use an aligning agent containing a cinnamate group. The weight average molecular weight of the polymer used as the alignment agent is, for example, about 10,000 to 1,000,000. The thickness of the alignment film is preferably 5 to 10,000 nm, and more preferably 10 to 500 nm from the viewpoint that the alignment regulating force is sufficiently developed.
The liquid crystal polarizing layer can be peeled off from the base material, transferred and laminated, or the base material can be laminated as it is. It is also preferable that the base material plays a role as a transparent base material for a protective film, a retardation film, or a window film.

  The protective film may be a transparent polymer film, and the same materials and additives used for the transparent substrate of the window film can be used. Moreover, the coating-type protective film obtained by apply | coating and hardening | curing radical curing compositions, such as cationic curing compositions, such as an epoxy resin, and an acrylate, may be sufficient. The protective film may be a plasticizer, an ultraviolet absorber, an infrared absorber, a colorant such as a pigment or a dye, a fluorescent brightener, a dispersant, a heat stabilizer, a light stabilizer, an antistatic agent, or an antioxidant, if necessary. Further, it may contain a lubricant, a solvent and the like. The thickness of the protective film is preferably 200 μm or less, more preferably 1 to 100 μm. When the thickness of the protective film is in the above range, the flexibility of the film tends to be difficult to decrease.

The λ / 4 phase difference plate is a film that gives a phase difference of λ / 4 in a direction (in-plane direction of the film) perpendicular to the traveling direction of incident light. The λ / 4 retardation plate may be a stretched retardation plate manufactured by stretching a polymer film such as a cellulose film, an olefin film, or a polycarbonate film. If necessary, the λ / 4 retardation plate is a retardation adjusting agent, a plasticizer, an ultraviolet absorber, an infrared absorber, a colorant such as a pigment or a dye, a fluorescent brightener, a dispersant, a heat stabilizer, and a light stabilizer. Agents, antistatic agents, antioxidants, lubricants, solvents and the like may be included.
The thickness of the stretchable phase difference plate is preferably 200 μm or less, more preferably 1 to 100 μm. When the thickness of the stretchable retardation plate is in the above range, the flexibility of the stretchable retardation plate tends to be difficult to decrease.
Furthermore, another example of the λ / 4 retardation plate is a liquid crystal coating type retardation plate formed by coating a liquid crystal composition.
The liquid crystal composition includes a liquid crystal compound exhibiting a liquid crystal state such as nematic, cholesteric, and smectic. The liquid crystalline compound has a polymerizable functional group.
The liquid crystal composition may further contain an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like.
The liquid crystal coating type retardation plate can be produced by coating and curing a liquid crystal composition on a base to form a liquid crystal retardation layer, similarly to the liquid crystal polarizing layer. The liquid crystal coated retardation plate can be formed thinner than the stretched retardation plate. The thickness of the liquid crystal polarizing layer is preferably 0.5 to 10 μm, more preferably 1 to 5 μm.
The liquid crystal coating type retardation plate can be peeled off from the substrate, transferred, and laminated, or the substrate can be laminated as it is. It is also preferable that the base material plays a role as a transparent base material for a protective film, a retardation film, or a window film.

In general, there are many materials that exhibit higher birefringence as the wavelength is shorter and smaller birefringence as the wavelength is longer. In this case, since the phase difference of λ / 4 cannot be achieved in the entire visible light region, the in-plane phase difference is preferably 100 to λ / 4 with respect to the vicinity of 560 nm where the visibility is high. It is designed to be 180 nm, more preferably 130 to 150 nm. A reverse dispersion λ / 4 retardation plate using a material having a birefringence wavelength dispersion characteristic opposite to that of a normal one is preferable in terms of good visibility. As such a material, for example, those described in Japanese Patent Application Laid-Open No. 2007-232873 can be used for the stretchable phase difference plate, and those described in Japanese Patent Application Laid-Open No. 2010-30979 can be used for the liquid crystal application type phase difference plate. .
As another method, a technique for obtaining a broadband λ / 4 phase difference plate by combining with a λ / 2 phase difference plate is also known (for example, JP-A-10-90521). The λ / 2 phase difference plate is also manufactured by the same material method as the λ / 4 phase difference plate. Although the combination of the stretching type retardation plate and the liquid crystal coating type retardation plate is arbitrary, both can be reduced in thickness by using the liquid crystal coating type retardation plate.
In order to improve the visibility in the oblique direction on the circularly polarizing plate, a method of laminating a positive C plate is known (for example, JP-A-2014-224837). The positive C plate may be a liquid crystal coated retardation plate or a stretched retardation plate. The retardation in the thickness direction of the retardation plate is preferably −200 to −20 nm, more preferably −140 to −40 nm.

<Touch sensor>
As described above, the flexible display device of the present invention preferably includes a touch sensor. The touch sensor is used as input means. Examples of the touch sensor include various types such as a resistive film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, a capacitance method, and preferably a capacitance method.
The capacitive touch sensor is divided into an active region and a non-active region located in an outer portion of the active region. The active area is an area corresponding to an area (display unit) where the screen is displayed on the display panel, and is an area where a user's touch is sensed. This is a region corresponding to the display unit. The touch sensor is formed of a flexible substrate, a sensing pattern formed in an active region of the substrate, and a non-active region of the substrate, and is connected to an external driving circuit through the sensing pattern and a pad portion. Each sensing line can be included. As the substrate having flexible characteristics, the same material as the transparent substrate of the window film can be used.

The sensing pattern may include a first pattern formed in a first direction and a second pattern formed in a second direction. The first pattern and the second pattern are arranged in different directions. The first pattern and the second pattern are formed in the same layer, and each pattern must be electrically connected in order to sense a touched point. The first pattern is a form in which a plurality of unit patterns are connected to each other through a joint, but the second pattern has a structure in which a plurality of unit patterns are separated from each other in an island form. A separate bridge electrode is required to connect them. A well-known transparent electrode can be applied to the electrode for connecting the second pattern. Examples of the material for the transparent electrode include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), and indium gallium zinc oxide (IGZO). , Cadmium tin oxide (CTO), PEDOT (poly (3,4-ethylenedithiothiophene)), carbon nanotube (CNT), graphene, metal wire, and the like, preferably ITO. These can be used alone or in admixture of two or more. The metal used for the metal wire is not particularly limited, and examples thereof include silver, gold, aluminum, copper, iron, nickel, titanium, telenium, and chromium. These may be used alone or in combination of two or more. Can do.
The bridge electrode may be formed on the sensing pattern with an insulating layer interposed therebetween. The bridge electrode may be formed on the substrate, and the insulating layer and the sensing pattern may be formed thereon. The bridge electrode may be formed of the same material as the sensing pattern, and may be formed of molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or an alloy of two or more thereof. it can.
Since the first pattern and the second pattern must be electrically insulated, an insulating layer is formed between the sensing pattern and the bridge electrode. The insulating layer can be formed only between the joint of the first pattern and the bridge electrode, or can be formed as a layer covering the entire sensing pattern. In the case of a layer covering the entire sensing pattern, the bridge electrode can be connected to the second pattern through a contact hole formed in the insulating layer.

The touch sensor is induced by a difference in transmittance between a pattern area where a sensing pattern is formed and a non-pattern area where a sensing pattern is not formed, specifically, a difference in refractive index in these areas. An optical adjusting layer may be further included between the substrate and the electrode as a means for appropriately compensating for the difference in light transmittance. The optical adjustment layer may include an inorganic insulating material or an organic insulating material. The optical adjustment layer can be formed by coating a photocurable composition containing a photocurable organic binder and a solvent on a substrate. The photocurable composition may further include inorganic particles. The refractive index of the optical adjustment layer can be increased by the inorganic particles.
The photocurable organic binder includes, for example, a copolymer of monomers such as an acrylate monomer, a styrene monomer, and a carboxylic acid monomer, as long as the effects of the present invention are not impaired. be able to. The photocurable organic binder may be a copolymer including different repeating units such as an epoxy group-containing repeating unit, an acrylate repeating unit, and a carboxylic acid repeating unit.
Examples of the inorganic particles include zirconia particles, titania particles, and alumina particles.
The photocurable composition may further contain additives such as a photopolymerization initiator, a polymerizable monomer, and a curing auxiliary agent.

<Adhesive layer>
Each layer (window film, circularly polarizing plate, touch sensor) forming the laminate for a flexible image display device and a film member (linear polarizing plate, λ / 4 retardation plate, etc.) constituting each layer are bonded with an adhesive. Can do. Examples of the adhesive include water-based adhesives, organic solvent-based, solvent-free adhesives, solid adhesives, solvent-evaporating adhesives, moisture-curing adhesives, heat-curing adhesives, anaerobic-curing adhesives, and active energy ray curing. Type adhesives, curing agent mixed adhesives, hot melt adhesives, pressure sensitive adhesives (adhesives), rewet adhesives, and other commonly used adhesives can be used, preferably aqueous solvent volatilization A mold adhesive, an active energy ray curable adhesive, and a pressure-sensitive adhesive can be used. The thickness of the adhesive layer can be appropriately adjusted according to the required adhesive strength and the like, and is preferably 0.01 to 500 μm, more preferably 0.1 to 300 μm. The laminate for a flexible image display device includes a plurality of adhesive layers, and the thickness and type of each may be the same or different.

  As the water-based solvent volatilization type adhesive, water-soluble polymers such as polyvinyl alcohol polymers and starches, water-dispersed polymers such as ethylene-vinyl acetate emulsions and styrene-butadiene emulsions can be used as the main polymer. In addition to the main polymer and water, a crosslinking agent, a silane compound, an ionic compound, a crosslinking catalyst, an antioxidant, a dye, a pigment, an inorganic filler, an organic solvent, and the like may be blended. In the case of bonding with the water-based solvent volatile adhesive, the water-based solvent volatile adhesive can be injected between the layers to be bonded, and the adhesion layer can be bonded, and then dried to provide adhesion. When using the said water-system solvent volatilization-type adhesive agent, the thickness of the contact bonding layer becomes like this. Preferably it is 0.01-10 micrometers, More preferably, it is 0.1-1 micrometer. When the aqueous solvent volatile adhesive is used in a plurality of layers, the thickness and type of each layer may be the same or different.

The active energy ray-curable adhesive can be formed by curing an active energy ray-curable composition containing a reactive material that irradiates active energy rays to form an adhesive layer. The active energy ray-curable composition can contain at least one polymer of a radical polymerizable compound and a cationic polymerizable compound similar to those contained in the hard coat composition. As the radical polymerizable compound, the same compound as the radical polymerizable compound in the hard coat composition can be used.
As the cationic polymerizable compound, the same compound as the cationic polymerizable compound in the hard coat composition can be used.
As the cationic polymerizable compound used in the active energy ray-curable composition, an epoxy compound is particularly preferable. In order to reduce the viscosity of the adhesive composition, it is also preferable to include a monofunctional compound as a reactive diluent.

The active energy ray composition can contain a monofunctional compound in order to reduce the viscosity. Examples of the monofunctional compound include an acrylate monomer having one (meth) acryloyl group in one molecule, a compound having one epoxy group or oxetanyl group in one molecule, such as glycidyl (meta ) Acrylate and the like.
The active energy ray composition can further contain a polymerization initiator. Examples of the polymerization initiator include radical polymerization initiators, cationic polymerization initiators, radicals and cationic polymerization initiators, and these are appropriately selected and used. These polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate radicals or cations to advance radical polymerization and cationic polymerization. In the description of the hard coat composition, an initiator capable of initiating at least one of radical polymerization or cationic polymerization by irradiation with active energy rays can be used.
The active energy ray curable composition further includes an ion scavenger, an antioxidant, a chain transfer agent, an adhesion promoter, a thermoplastic resin, a filler, a flow viscosity modifier, a plasticizer, an antifoaming solvent, an additive, a solvent. Can be included. When adhering two adherend layers with the active energy ray curable adhesive, the active energy ray curable composition is applied to one or both of the adherend layers and then bonded, and either adherend layer is applied. Alternatively, both of the adherend layers can be bonded together by irradiating them with active energy rays and curing them. When using the said active energy ray hardening-type adhesive agent, the thickness of the contact bonding layer becomes like this. Preferably it is 0.01-20 micrometers, More preferably, it is 0.1-10 micrometers. When the active energy ray-curable adhesive is used for forming a plurality of adhesive layers, the thickness and type of each layer may be the same or different.

  The pressure-sensitive adhesive is classified into an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, and the like depending on the main polymer, and any of them can be used. In addition to the main polymer, the adhesive may contain a crosslinking agent, a silane compound, an ionic compound, a crosslinking catalyst, an antioxidant, a tackifier, a plasticizer, a dye, a pigment, an inorganic filler, and the like. Each component constituting the pressure-sensitive adhesive is dissolved / dispersed in a solvent to obtain a pressure-sensitive adhesive composition, and the pressure-sensitive adhesive composition is coated on a substrate and then dried to form a pressure-sensitive adhesive layer adhesive layer. The The pressure-sensitive adhesive layer may be directly formed, or a layer separately formed on the substrate can be transferred. In order to cover the adhesive surface before bonding, it is also preferred to use a release film. When using the said active energy ray hardening-type adhesive agent, the thickness of the contact bonding layer becomes like this. Preferably it is 0.1-500 micrometers, More preferably, it is 1-300 micrometers. When a plurality of layers of the pressure-sensitive adhesive are used, the thickness and type of each layer may be the same or different.

<Shading pattern>
The light shielding pattern can be applied as at least a part of a bezel or a housing of the flexible image display device. The visibility of the image is improved by concealing the wiring arranged at the edge portion of the flexible image display device by the light shielding pattern and making it difficult to see. The light shielding pattern may be a single layer or a multilayer. The color of the light shielding pattern is not particularly limited, and may be various colors such as black, white, and metal color. The light shielding pattern can be formed of a pigment for embodying a color and a polymer such as an acrylic resin, an ester resin, an epoxy resin, polyurethane, or silicone. These can be used alone or in a mixture of two or more. The light shielding pattern can be formed by various methods such as printing, lithography, and inkjet. The thickness of the light shielding pattern is preferably 1 to 100 μm, more preferably 2 to 50 μm. It is also preferable to give a shape such as an inclination in the thickness direction of the light shielding pattern.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. Unless otherwise specified, “%” and “parts” in the examples mean mass% and parts by mass. First, a method for measuring physical properties will be described.

<Weight average molecular weight>
Gel Permeation Chromatography (GPC) Measurement (1) Pretreatment Method After dissolving the sample in γ-butyrolactone (GBL) to make a 20% by mass solution, the sample was diluted 100 times with a DMF eluent, and a 0.45 μm membrane filter The filtered solution was used as a measurement solution.
(2) Measurement condition column: TSKgel SuperAWM-H × 2 + SuperAW2500 × 1 (6.0 mm ID × 150 mm × 3)
Eluent: DMF (10 mM lithium bromide added)
Flow rate: 0.6 mL / min Detector: RI detector Column temperature: 40 ° C
Injection volume: 20 μL
Molecular weight standard: Standard polystyrene

<Imidization rate>
The imidation ratio was determined by ¹ H-NMR measurement as follows.
(1) Pretreatment method The sample was dissolved in deuterated dimethyl sulfoxide (DMSO-d ₆ ) to give a 2% by mass solution, which was used as the measurement solution.
(2) Measuring condition measuring device: 400 MHz NMR device made by JEOL JNM-ECZ400S / L1
Standard substance: DMSO-d ₆ (2.5 ppm)
Sample temperature: Room temperature integration number: 256 times Relaxation time: 5 seconds (3) Imidization rate analysis method (3-1) Imidation rate of polyimide resin A ¹ H-NMR spectrum obtained for the measurement solution containing polyimide resin A Among the benzene protons observed in Fig. 1, the integrated value of the benzene proton A derived from a structure that does not change before and after imidation was defined as Int _A.
Further, the integral value of the amide proton derived from the amic acid structure remaining in the polyimide resin was defined as Int _B. Based on these integral values, the imidation ratio of the polyimide resin A was determined based on the following formula. In the following formula, α is the number ratio of benzene protons A to one amide proton in the case of polyamic acid (imidation rate 0%).
Imidization rate (%) = 100 × (1−α × Int _B / Int _A )
(3-2) Imidation ratio of polyamideimide resin A Derived from a structure that does not change before and after imidation among benzene protons observed in a ¹ H-NMR spectrum obtained for a measurement solution containing polyamideimide resin A, The integrated value of benzene proton C that is not affected by the structure derived from the amic acid structure remaining in the polyamideimide resin was defined as Int _C.
Further, the integrated value of the benzene proton D derived from the structure that does not change before and after imidation among the observed benzene protons and influenced by the structure derived from the amic acid structure remaining in the polyamide-imide resin A is defined as Int _D. . The β value was determined from these integral values based on the following equation.
β = Int _D / Int _C
Next, in order to obtain a correlation formula for converting β into an imidization rate, for a plurality of polyamideimide resins having different imidization rates, β values are obtained in the same manner as described above, and the imidization rate is calculated using an HSQC spectrum. The following correlation formula was obtained from these results.
Imidization rate (%) = k × β + 100
In the above correlation equation, k is a constant.
Next, β obtained for the polyamideimide resin A was substituted into the above correlation equation to obtain an imidization ratio (%) of the polyamideimide resin A.

<Average primary particle size>
The specific surface area of the powder obtained by drying the silica sol at 300 ° C. was measured using a specific surface area measuring device Monosorb MS-16 manufactured by Yuasa Ionis Co., Ltd., and the measured specific surface area S (m ² / g) was used. , D (nm) = 2720 / S was used to calculate the average primary particle size.

<Viscosity of varnish>
Based on JIS K 8803: 2011, it measured using the Brookfield E-type viscosity meter DV-II + Pro. The measurement temperature was 25 ° C.

<Thickness of film>
Using a Mitutoyo Co., Ltd. ID-C112XBS, the thickness of 10 or more films was measured, and the average value was calculated.

<Functional layer thickness>
The thickness of the functional layer was measured using the F20 tabletop film thickness system manufactured by Filmmetrics.

<Total light transmittance of film, Haze>
The optical characteristic values were measured using a spectrocolorimeter CM-3700A manufactured by Konica Minolta.

<Yellowness of film>
The yellowness (Yellow Index: YI value) of the optical film was measured using a spectrocolorimeter CM-3700A manufactured by Konica Minolta. Specifically, after performing background measurement in the absence of a sample, an optical film is set on a sample holder, transmittance measurement for light of 300 to 800 nm is performed, and tristimulus values (X, Y, Z) The YI value was calculated based on the following formula.
YI = 100 × (1.2769X−1.0592Z) / Y

  Based on JIS K 5600-5-4: 1999, the pencil hardness of the functional layer surface of the optical laminate was measured. The load during measurement was 750 g, and the measurement speed was 4.5 mm / sec.

<Measurement of surface resistivity>
Using a resistivity meter (manufactured by Mitsubishi Chemical Analytech, Hiresta UP MCP-HT450 type), the surface resistivity (Ω / sq) of the optical laminate was measured according to JIS K6911. The sample was cut into a size of 50 mm × 50 mm, and the obtained sample was left at 23 ° C. and 50% RH for 24 hours. Thereafter, the surface resistivity on the functional layer side of the optical laminate was measured. In addition, the measurement upper limit of this apparatus is 1.0E + 14 ohm / sq, and when it has a surface resistivity more than it, it describes with OVER on an apparatus.

<Method for evaluating optical homogeneity of optical film or optical laminate>
1. Shooting of Projected Image and Background Image In the dark room, as shown in FIG. The distance between the light source 1 and the measurement film 2 is 250 cm, the distance between the measurement film 2 and the projection surface 3 is 30 cm, the measurement film 2 and the projection surface 3 are arranged in parallel, and the camera 6 is connected to the screen from the light source 1. The distance between the camera 6 and the projection plane 3 (screen) is 30 cm, and the camera angle 7 (from the state where the camera is oriented perpendicular to the screen, The angle of inclination was 25 degrees. Further, the background image was photographed in the same manner as the projection image except that the measurement film 2 was removed in FIG. Details of measurement conditions and imaging conditions are shown below.
Light source: LED light source (“LA-HDF15T” manufactured by Hayashi Clock Industry Co., Ltd.)
Measurement film: Optical films or optical laminates produced in the following Examples and Comparative Examples were cut into 200 mm × 300 mm, and used as measurement samples.
Projection surface: White commercially available movie viewing screen ("BTP600FHD-SH1000" manufactured by Theater House Co., Ltd.)
Camera: “COOLPIX (registered trademark) P600” manufactured by Nikon Corporation
Advanced camera settings: Shooting mode Manual shooting
Image size 2M
Focus Manual focus (distance 0.3m)
Shutter speed 1/2 second
Aperture value (F value) 4.2
Flash off

図４に示される実施例１で得たラインプロファイル（データＹ）について、上記補正を行うことにより、図５に示されるようなラインプロファイルＡ（データＹ’）が得られる。
次に、１で得た背景画像についても同様の操作を行い、背景画像のラインプロファイルを得た。具体的には、図６に示されるようなラインプロファイルＢが得られた。
次いで、上記のプロファイルＡから、バックグラウンドのプロファイルＢをＥｘｃｅｌにより引いて、ブランク補正を行った。実施例１では、図５に示されるラインプロファイルＡのデータＹ’から、図６に示されるようなラインプロファイルＢのデータを引いて、図７に示されるようなブランク補正されたラインプロファイルＡ−Ｂを得た。
このようにして得たラインプロファイルをスムージングして、Ｙ”のプロファイルを得、これをラインプロファイルの最大強度（Ｙ_ｍｈ１及びＹ_ｍｖ１）の測定に使用した。グラフのスムージングは、次の式に従い、２１個のデータの平均値であるｙ_ｉを算出して行った。

2. Fourier Transform In this embodiment, since the camera is installed at the position of the camera angle, the projected image is inclined. Therefore, in order to correct the inclination of the projection image, the inclination correction condition is first determined. If there is no distortion of the projected image, no correction is necessary.
(Determination of tilt correction conditions)
A square of 10 cm × 10 cm was written on a transparent film, and a reference projection image was taken under the above condition 1. The obtained reference projection image is read by Photoshop (registered trademark) CS4 manufactured by Adobe Systems, and is corrected so that the camera and screen correspond to 90 degrees using the lens correction distortion correction function. Saved with. The conditions at this time were set as inclination correction conditions. From the reference projection image after the inclination correction, the lengths per pixel in the vertical and horizontal directions were calculated (vertical: 816 pixels = 10 cm, horizontal: 906 pixels = 10 cm).
(Fourier transform)
The projection image obtained as described above for the measurement film was corrected under the inclination correction conditions determined as described above, and the corrected image was stored in the TIFF format. The obtained projection image after tilt correction was converted into a numerical value by converting it into an 8-bit gray scale using image analysis software “Image-J, ver. 1.48”. In addition, the length per each pixel of the vertical and horizontal obtained from the reference | standard projection image after inclination correction was used as Set Scale. A rectangular range having a size of 10.2 cm × 11.2 cm (vertical × horizontal) is selected from the grayscale image, and the image in the selected range is Fourier-transformed using Imag stirring e-J to obtain an inverse aerial image. Got. For the inverse aerial image after Fourier transform, correct values (horizontal direction: ¹ pixel = 11.3 cm ⁻¹ , vertical direction: ¹ pixel = 12.55 cm ⁻¹ ) were input to Set Scale.
3. Measurement of the maximum intensity (Y _mh1 and Y _mv1 ) of the line profile _subjected to blank correction In the inverse aerial image obtained as described above, the horizontal direction (h1 direction) and the vertical direction (v1 direction) passing through the center of the inverse aerial image. Line profiles were created for each direction. The line width was 10 pixels. The obtained line profile was saved in text format. Next, the text format data is read by Microsoft Excel (ver. 14.0), the line profile is normalized as follows, and the horizontal direction (h1 direction) and the vertical direction (v1 direction) respectively. For each direction, the maximum intensity Y _{max is set} to Y _mh1 and Y _mv1 in each line profile, and all frequencies in the line profile blank-corrected from the frequency indicating the maximum intensity Y _mh1 and Y _mv1 are obtained. X _max that is a value obtained by subtracting the median value X _cen is defined as X _mh1 and X _mv1 , respectively.
(Standardization method)
The frequency at which the value of Y is maximum is the center of X (X _cen ), and the value of Y at that time is Y _cen . Next, an average value of Y is obtained for an area of 100 pixels in total of 50 pixels at both ends with X _cen as the center, and the average value is set as a baseline (Y _base ). Then, the data Y is corrected according to the following equation so that Y _cen = 100 and Y _base = 0, and Y ′ is obtained.

The line profile A (data Y ′) as shown in FIG. 5 is obtained by performing the above correction on the line profile (data Y) obtained in the first embodiment shown in FIG.
Next, the same operation was performed on the background image obtained in 1 to obtain a line profile of the background image. Specifically, a line profile B as shown in FIG. 6 was obtained.
Next, blank correction was performed by subtracting the background profile B from Excel from the above profile A. In the first embodiment, the data Y ′ of the line profile A shown in FIG. 5 is subtracted from the data of the line profile B as shown in FIG. B was obtained.
The line profile thus obtained was smoothed to obtain a profile of Y ″, which was used to measure the maximum intensity (Y _mh1 and Y _mv1 ) of the line profile. The calculation was performed by calculating y _i which is an average value of 21 data.

(Visibility sensory evaluation)
In an indoor environment adjusted to 50 to 100 lux, the produced film was visually inspected from an angle of elevation of 80 degrees, and the visibility was evaluated from the distortion of the reflected background. The results are shown in Table 2. In addition, the evaluation criteria of visibility are as follows.
A: No distortion is confirmed in the background.
◯: Almost no distortion is confirmed in the background.
(Triangle | delta): Although a very slight distortion is confirmed in a background, it is a level which does not have a problem.
X: A clear distortion is confirmed in the background.

<Residual solvent amount>
Using TG-DTA (EXSTAR 6000 TG / DTA 6300 manufactured by SII), the transparent resin films obtained in Examples 1 and 2 and Comparative Example 2 were heated from 30 ° C. to 120 ° C., and at 120 ° C. for 5 minutes. Then, the temperature was raised to 400 ° C. at a rate of 5 ° C./min. The ratio of the mass reduction of the film at 120 ° C. to 250 ° C. with respect to the mass of the film at 120 ° C. was calculated as the solvent content (referred to as the residual solvent amount).

Abbreviations used in the following production examples and examples are as follows.
TFMB: 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl 6FDA: 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride TPC: terephthaloyl chloride OBBC: 4, 4 '-Oxybis (benzoyl chloride)
DMAc: N, N-dimethylacetamide GBL: γ-butyrolactone PET: polyethylene terephthalate

<Production example>
Production Example 1 Production of Polyamidoimide Resin 1 In a nitrogen gas atmosphere, a reaction vessel provided with a stirring blade in a separable flask and an oil bath were prepared. 45 parts of TFMB and 768.55 parts of DMAc were charged into a reaction vessel installed in the oil bath. While stirring the contents in the reaction vessel at room temperature, TFMB was dissolved in DMAc. Next, 19.01 parts of 6FDA was further charged into the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 3 hours. Thereafter, 4.21 parts of OBBC and then 17.30 parts of TPC were charged into the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 1 hour. Next, 4.63 parts of 4-methylpyridine and 13.04 parts of acetic anhydride were further charged into the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 30 minutes. After stirring, the temperature in the container was raised to 70 ° C. using an oil bath, and maintained at 70 ° C. and further stirred for 3 hours to obtain a reaction solution.
The obtained reaction solution was cooled to room temperature and poured into a large amount of methanol in the form of a thread to deposit a precipitate. The deposited precipitate was taken out, immersed in methanol for 6 hours, and washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C. to obtain a polyamideimide resin 1. The obtained polyamideimide resin 1 had a weight average molecular weight of 400,000 and an imidization ratio of 99.0%.

Production Example 2: Production of Polyimide Resin 1 A reactor equipped with a silica gel tube, a stirrer and a thermometer in a separable flask and an oil bath were prepared. Into this flask, 75.52 parts of 6FDA and 54.44 parts of TFMB were charged. While this was stirred at 400 rpm, 519.84 parts of DMAc was added, and stirring was continued until the contents of the flask became a homogeneous solution. Subsequently, stirring was further continued for 20 hours while adjusting the temperature in the container to be in the range of 20 to 30 ° C. using an oil bath, and reaction was performed to generate polyamic acid. After 30 minutes, the stirring speed was changed to 100 rpm. After stirring for 20 hours, the reaction system temperature was returned to room temperature, and DMAc (649.8 parts) was added to adjust the polymer concentration to 10% by mass. Furthermore, 32.27 parts of pyridine and 41.65 parts of acetic anhydride were added, and imidation was performed by stirring at room temperature for 10 hours. The polyimide varnish was taken out from the reaction vessel. The obtained polyimide varnish was dropped into methanol for reprecipitation, and the obtained powder was dried by heating to remove the solvent, thereby obtaining a polyimide resin 1 as a solid content. About the obtained polyimide resin 1, when the GPC measurement was performed, the weight average molecular weight was 320,000. Moreover, the imidation ratio of the polyimide was 98.6%.

Production Example 3: Preparation of silica sol 1 GBL-substituted silica sol was prepared by solvent substitution using amorphous silica sol having an average primary particle diameter (average primary particle diameter measured by BET method) of 12 nm prepared by a sol-gel method as a raw material. . The obtained sol was filtered through a membrane filter having an opening of 10 μm to obtain a GBL-substituted silica sol 1. In the obtained GBL-substituted silica sol 1, the content of silica particles was 30 to 32% by mass.

Production Example 4: Preparation of Varnish (1) Polyamideimide resin 1 obtained in Production Example 1 and silica sol 1 obtained in Production Example 3 were combined with a composition ratio of polyamideimide resin: silica particles in a GBL solvent of 70: The mixture was mixed to 30. In the obtained mixed solution, 2.0 phr of UV-A ultraviolet absorber “Sumisorb (registered trademark) 250” (molecular weight 389, manufactured by Sumika Chemtex Co., Ltd.) with respect to the total mass of the polyamideimide resin and silica particles, and 35 ppm of blueing agent “Sumiplast (registered trademark) Violet B” (manufactured by Sumika Chemtex Co., Ltd.) is added with respect to the total mass of the polyamideimide resin and silica particles, and the mixture is stirred until it becomes uniform. Got. The varnish (1) had a solid content of 9.7% and a viscosity at 25 ° C. of 39,600 cps.

Production Example 5: Preparation of Varnish (2) Polyimide resin 1 obtained in Production Example 2 and an ultraviolet absorber “Sumisorb 250” (molecular weight 389, manufactured by Sumika Chemtex Co., Ltd.) of 2.0 phr with respect to the polyimide resin ) Was dissolved in a mixed solvent of GBL: DMAc = 1: 9 at a concentration of 16.5% by mass to obtain varnish (2). The varnish (2) had a solid content of 16.5% and a viscosity at 25 ° C. of 36,800 cps.

Production Example 6: Photocurable resin composition 1
28.4 parts by mass of trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., A-TMPT), 28.4 parts by mass of pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., A-TMMT), photopolymerization started As an agent, 1.8 parts by mass of 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Corporation, Irgacure (registered trademark) 184), lithium bis (fluorosulfonyl) imide (manufactured by Tokyo Chemical Industry Co., Ltd., LiFSI) 2.4 Part by mass, 0.1 part by mass of a leveling agent (BIC Chemie Japan Co., Ltd., BYK (registered trademark) -307), and 39 parts by mass of propylene glycol 1-monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) As a result, a photocurable resin composition 1 was obtained.

Production Example 7: Photocurable resin composition 2
Except that lithium bis (fluorosulfonyl) imide was not mixed, the same compound as in Production Example 6 was stirred and mixed to obtain a photocurable resin composition 2.

Example 1
Varnish (1) was applied onto a PET film (Toyobo Co., Ltd. “Cosmo Shine (registered trademark) A4100”, thickness 188 μm, thickness distribution ± 2 μm), and fluted to form a varnish coating. At this time, the linear velocity was 0.8 m / min. The varnish coating is heated at 80 ° C. for 10 minutes, then heated at 100 ° C. for 10 minutes, then heated at 90 ° C. for 10 minutes, and finally heated at 80 ° C. for 10 minutes. A film was formed. Then, the coating film was peeled from the PET film to obtain a raw material film 1 in the form of a film roll having a thickness of 58 μm, a width of 700 mm, and a length of 500 m. The amount of residual solvent in the raw material film 1 was 9.7% by mass. Next, the raw material film 1 was heated at 200 ° C. for 25 minutes with a film transverse stretching apparatus (tenter) under conditions of a stretching ratio of 0.98 times to obtain a polyamideimide film 1 having a thickness of 50 μm. The amount of residual solvent in the polyamideimide film 1 was 0.7% by mass.
On one side of the obtained polyamideimide film 1, the photocurable resin composition 1 was coated by a bar coater by a roll-to-roll method so that the thickness after drying was 10 μm. Then, drying was performed in an oven at 80 ° C. for 3 minutes, and the optical laminate 1 in the form of a film roll having a length of 400 m was obtained by irradiating and curing ultraviolet rays with an energy of a high-pressure mercury lamp 500 mJ / cm ² . The thickness of the functional layer in the optical laminated body 1 was 10 μm.

Example 2
An optical laminate 2 in the form of a film roll having a length of 400 m was obtained in the same manner as in Example 1 except that the photocurable resin composition 2 was used instead of the photocurable resin composition 1. The thickness of the functional layer in the optical laminate 2 was 11 μm.

Example 3
Using varnish (2) instead of varnish (1), drying conditions were heated at 75 ° C. for 7.5 minutes, then heated at 120 ° C. for 7.5 minutes, then heated at 70 ° C. for 7.5 minutes, and finally A raw material film 2 in the form of a film roll having a thickness of 89 μm, a width of 700 mm, and a length of 600 m was obtained in the same manner as in Example 1 except that the conditions were changed to the conditions of heating at 80 ° C. for 7.5 minutes. The amount of residual solvent in the raw material film 2 was 9.6% by mass. Next, a polyimide film 1 having a thickness of 77 μm was obtained in the same manner as in Example 1 except that the raw material film 2 was used instead of the raw material film 1. The amount of residual solvent in the polyimide film 1 was 1.1 mass%.
An optical laminate 3 in the form of a film roll having a length of 500 m was obtained in the same manner as in Example 2 except that the polyimide film 1 was used instead of the polyamideimide film 1. The thickness of the functional layer in the optical laminated body 3 was 9 μm.

Comparative Example 2
Using varnish (2), the drying condition was heated at 100 ° C. for 7.5 minutes, then heated at 120 ° C. for 7.5 minutes, then heated at 60 ° C. for 7.5 minutes, and finally at 60 ° C. A raw material film 4 in the form of a film roll having a thickness of 89 μm, a width of 700 mm, and a length of 300 m was obtained in the same manner as in Example 1, except that the conditions were changed to heating for 5 minutes. The amount of residual solvent in the raw material film 4 was 9.9 mass%. Next, a polyimide film 2 having a thickness of 77 μm was obtained in the same manner as in Example 1 except that the raw material film 4 was used instead of the raw material film 1. The amount of residual solvent in the polyimide film 2 was 1.0 mass%.
An optical laminate 5 in the form of a film roll having a length of 190 m was obtained in the same manner as in Example 2 except that the polyimide film 2 was used instead of the polyamideimide film 1. The thickness of the functional layer in the optical laminated body 5 was 11 μm.

Tables 1 and 2 show the results of measuring various physical properties of the optical laminates obtained in Examples and Comparative Examples according to the above measurement methods. In addition, Haze of the film of an Example and a comparative example was all 0.2. Moreover, about each value for evaluating the optical homogeneity in Table 2, the value in which the measurement sample is described as a film is a value measured for a polyamideimide film or a polyimide film before laminating the functional layer. The value in which the measurement sample is described as a laminate is a value measured for the optical laminate after the functional layers are laminated. The evaluation of visibility is a result of evaluating the optical laminate.

The optical laminates of Examples 1 to 3 or the optical films contained in the optical laminates have Y _mh and Y _mv of 40 or less, A / B of less than 30, and visibility evaluation is Or it was as good as ◯. On the other hand, the optical film contained in the optical laminate of Comparative Example 2 had a Y _mh of over 40, an A / B of 30 or more, and a visibility evaluation result of x. In addition, about the optical laminated body of the comparative example 2 , although results, such as _{Ymh at the} time of using an optical laminated body as a measurement film, are not described, Y _mh is similar to the result obtained by using an optical film as a measurement film. Etc. and A / B are considered not to fall within the range specified for the optical laminate of the present invention. In addition, the functional layer in the optical layered body of Example 1 could be provided with an antistatic function in addition to the hard coat function. Similarly, the functional layers of Examples 1 to 3 may have additional functions such as an antistatic function, an antiglare function, a low reflection function, an antireflection function, and an antifouling function in addition to the hard coat function. It was a layer.

DESCRIPTION OF SYMBOLS 1 Light source 2 Measurement film 3 Projection surface 4 Projection image 5 Light 6 Camera 7 Camera angle

Claims (10)

An optical film containing a polyimide resin and / or a polyamide resin, and a functional layer having at least one function selected from the group consisting of a hard coat function and an antistatic function, laminated on at least one surface of the optical film. An optical laminate comprising:
Line profiles in the direction h and the direction v orthogonal to each other in the film inverse aerial image obtained by Fourier transforming the projection image obtained by the projection method using the optical layered body are defined as the line profile h and the line profile v, respectively. In the background inverse aerial image obtained by Fourier transforming the background image obtained without using the optical laminate in the method, the line profiles in the direction h ′ and the direction v ′ orthogonal to each other are respectively represented as a line profile h ′ and a line profile v ′. Y _mh is the maximum intensity of the line profile (h ′) obtained by subtracting the line profile h ′ from the line profile h, X _mh is the frequency indicating the maximum intensity Y _mh , and the line profile v to the line profile v Maximum of line profile (v-v ') obtained by subtracting The degrees and _{Y mv,} and the frequency showing the maximum intensity _{Y mv} and _{X mv, Y mh} and _{Y mv} is any even 40 or _{less, Y mh, Y mv, X} mh and _{X mv} is the following relationship:

An optical laminate satisfying the above requirements. The optical laminate according to claim 1, wherein the pencil hardness of at least one surface of the optical laminate is H or more. The optical laminate according to claim 1 or 2 , wherein the surface resistivity of at least one surface of the optical laminate is 1.0 x 10 ¹³ Ω / sq or less. Yellowness of the optical stack is 3.0 or less, the optical laminate according to any one of claims 1-3. The optical laminate according to any one of claims 1 to 4 , wherein the length in the width direction is 20 cm or more and the length in the length direction is 1 m or more. The optical laminate according to any one of claims 1 to 5 , which is a film for a front plate of a flexible display device. A flexible display apparatus provided with the optical laminated body in any one of Claims 1-6 . The flexible display device according to claim 7 , further comprising a touch sensor. The flexible display device according to claim 7 , further comprising a polarizing plate. It is a manufacturing method of the optical layered product according to any one of claims 1 to 6 ,
(A) a step of applying a polyimide resin and / or a polyamide resin, and a varnish containing at least a solvent on a support and drying to form a coating film;
(B) a step of peeling the coating film from the support;
(C) heating the peeled coating film to obtain a film; and
(D) A production method including at least a step of laminating a functional layer on at least one surface of the film to obtain an optical laminate.

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