JP6771525B2 - Optical laminate - Google Patents

Description

The present invention relates to an optical laminate used as a front plate or the like of an image display device, and a flexible image display device including the optical laminate.

Image display devices such as liquid crystal display devices and organic EL display devices are widely used in various applications such as mobile phones and smart watches. Glass has been used as the front plate of such an image display device. Glass has high transparency and can exhibit high hardness depending on the type of glass, but it is very rigid and fragile, so that it is difficult to use it as a front plate material for a flexible display. Therefore, the use of polymer materials as an alternative material to glass is being studied. Since the front plate made of a polymer material easily exhibits flexible properties, it can be expected to be used for various purposes. There are various types of flexible resins, one of which is polyamide-imide. Polyamideimide is used for various purposes from the viewpoint of transparency and heat resistance (for example, Japanese Patent Application Laid-Open No. 2016-125063).

Japanese Unexamined Patent Publication No. 2016-125063

The front plate of such an image display device is required to have a high surface hardness because the user directly contacts the image display device and the surrounding objects come into direct contact with the front plate. However, according to the study by the present inventor, it has been found that the surface hardness of the optical laminate containing the polyamide resin may not be sufficient.

Therefore, an object of the present invention is to provide an optical laminate having excellent surface hardness and a flexible image display device including the optical laminate.

As a result of diligent studies to solve the above problems, the present inventor has contained an aromatic compound in the base film in an optical laminate having a hard coat layer on at least one surface of the base film containing a polyamide resin. Then, they found that the above object was achieved, and completed the present invention. That is, the present invention includes the following.

［式（１）及び式（２）中、Ｘ及びＺは、それぞれ独立に、２価の有機基を表し、Ｙは４価の有機基を表す］
で表される構成単位を有し、式（２）で表される構成単位の含有量は、式（１）で表される構成単位１モルに対して、０．１〜３．９モルである、［２］〜［４］のいずれかに記載の光学積層体。
［６］基材フィルムに含まれる紫外線吸収剤の含有量は、ハードコート層中の紫外線吸収剤の含有量よりも大きい、［３］〜［５］のいずれかに記載の光学積層体。
［７］基材フィルムは、無機粒子を含む、［１］〜［６］のいずれかに記載の光学積層体。
［８］３９０ｎｍにおける光線透過率は、３５％以下である、［１］〜［７］のいずれかに記載の光学積層体。
［９］ポリアミドイミドは、式（１）及び式（２）：

［式（１）及び式（２）中、Ｘ及びＺは、それぞれ独立に、２価の有機基を表し、Ｙは４価の有機基を表し、
Ｚの少なくとも一部は、式（３）：

（式（３）中、Ｒ^１〜Ｒ^８は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基又は炭素数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、それぞれ独立に、ハロゲン原子で置換されていてもよく、
Ａは、−Ｏ−、−Ｓ−、−ＣＯ−又は−Ｎ（Ｒ^９）−を表し、Ｒ^９はハロゲン原子で置換されていてもよい炭素数１〜１２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）
で表される構成単位である］
で表される構成単位を有する、［２］〜［８］のいずれかに記載の光学積層体。
［１０］［１］〜［９］のいずれかに記載の光学積層体を備える、フレキシブル画像表示装置。
［１１］さらに偏光板を含む、［１０］に記載のフレキシブル画像表示装置。
［１２］さらにタッチセンサを含む、［１０］又は［１１］に記載のフレキシブル画像表示装置。 [1] An optical laminate having a base film containing a polyamide resin and an aromatic compound and a hard coat layer on at least one surface of the base film.
[2] The optical laminate according to [1], wherein the polyamide-based resin is polyamide-imide.
[3] The optical laminate according to [1] or [2], wherein the aromatic compound is an ultraviolet absorber.
[4] The optical laminate according to [3], wherein the content of the ultraviolet absorber is 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyamide resin.
[5] Polyamideimides have the formulas (1) and (2):

[In formulas (1) and (2), X and Z each independently represent a divalent organic group, and Y represents a tetravalent organic group].
The content of the structural unit represented by the formula (2) is 0.1 to 3.9 mol with respect to 1 mol of the structural unit represented by the formula (1). The optical laminate according to any one of [2] to [4].
[6] The optical laminate according to any one of [3] to [5], wherein the content of the ultraviolet absorber contained in the base film is larger than the content of the ultraviolet absorber in the hard coat layer.
[7] The optical laminate according to any one of [1] to [6], wherein the base film contains inorganic particles.
[8] The optical laminate according to any one of [1] to [7], wherein the light transmittance at 390 nm is 35% or less.
[9] Polyamideimides have the formulas (1) and (2):

[In formulas (1) and (2), X and Z each independently represent a divalent organic group, and Y represents a tetravalent organic group.
At least a part of Z is the equation (3):

In formula (3), R ^{1 to} R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and hydrogen contained in R ^{1 to} R ⁸ is contained. Atoms may be independently substituted with halogen atoms,
A represents -O-, -S-, -CO- or -N (R ⁹ )-, and R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom.
m is an integer from 0 to 4
* Represents a bond)
It is a structural unit represented by]
The optical laminate according to any one of [2] to [8], which has a structural unit represented by.
[10] A flexible image display device comprising the optical laminate according to any one of [1] to [9].
[11] The flexible image display device according to [10], further including a polarizing plate.
[12] The flexible image display device according to [10] or [11], further including a touch sensor.

The optical laminate of the present invention has excellent surface hardness.

It is a figure which shows an example of the layer structure in the optical laminated body of this invention.

The optical laminate of the present invention has a base film containing a polyamide resin and an aromatic compound, and a hard coat layer on at least one surface of the base film.

<Base film>
The base film contains a polyamide resin and an aromatic compound.

(Polyamide resin)
The polyamide-based resin indicates polyamide and polyamide-imide. Polyamide means a polymer containing a structural unit containing an amide group. Polyamide-imide means a polymer containing a structural unit containing both an imide group and an amide group.

The polyamide-based resin may be polyamide, and is preferably polyamide-imide from the viewpoint of the surface hardness of the optical laminate.

The polyamide preferably has a structural unit represented by the formula (2), and the polyamide-imide has a structural unit represented by the formula (1) and a structural unit represented by the formula (2). Is preferable.

In the formula (2), Z is a divalent organic group, preferably substituted with a hydrocarbon group having 1 to 8 carbon atoms or a hydrocarbon group having 1 to 8 carbon atoms substituted with fluorine. It is an organic group having 4 to 40 carbon atoms. As the organic group of Z, the formula (20), the formula (21), the formula (22), the formula (23), the formula (24), the formula (25), the formula (26), the formula (27), the formula (28) And, among the group bonds represented by the formula (29), a group in which two non-adjacent groups are replaced with a hydrogen atom and a divalent chain hydrocarbon group having 6 or less carbon atoms are exemplified. Groups represented by formulas (20) to (27) are preferable because it is easy to suppress the yellowness of the obtained film (reduce the YI value).

In one embodiment of the present invention, the polyamide resin may contain a plurality of types of Z, and the plurality of types of Z may be the same or different from each other. In particular, from the viewpoint that the optical laminate can exhibit low yellowness (YI value) in addition to high surface hardness, at least a part of Z is represented by the formula (3).

［式（３）中、Ｒ^１〜Ｒ^８は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基又は炭素数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、それぞれ独立に、ハロゲン原子で置換されていてもよく、
Ａは、−Ｏ−、−Ｓ−、−ＣＯ−又は−Ｎ（Ｒ^９）−を表し、Ｒ^９は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］
で表される構成単位であることが好ましい。

[In formula (3), R ^{1 to} R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and hydrogen contained in R ^{1 to} R ⁸ is contained. Atoms may be independently substituted with halogen atoms,
A represents -O-, -S-, -CO- or -N (R ⁹ )-, and R ⁹ is a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Represent,
m is an integer from 0 to 4
* Represents a bond]
It is preferable that it is a structural unit represented by.

In the formula (3), A is independently, -O -, - S -, - CO- or -N ^{(R 9)} - represents, in terms of the flexibility of the optical stack, preferably -O- Alternatively, it represents −S−, more preferably −O−.

R ^{1 to} R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of alkyl groups 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 and 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 aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xsilyl group, a naphthyl group, a biphenyl group and the like. From the viewpoint of surface hardness and flexibility of the optical laminate, R ^{1 to} R ⁸ independently represent hydrogen atoms or alkyl groups having 1 to 6 carbon atoms, and more preferably hydrogen atoms or 1 to 6 carbon atoms. It represents an alkyl group of 3, 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 monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of monovalent hydrocarbon groups 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 and 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 and the like. These may be substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

In the formula (3), m is an integer in the range of 0 to 4, and when m is in this range, the flexibility of the optical laminate is good. Further, in the formula (3), m is preferably an integer in the range of 0 to 3, more preferably an integer in the range of 0 to 2, more preferably 0 or 1, and m is within this range. The flexibility of the optical laminate is good, and at the same time, the availability of raw materials is relatively good. Further, Z may contain one or more structural units represented by the formula (3), which improves the surface hardness, elastic modulus and bending resistance of the optical laminate, and yellowness (YI value). ) From the viewpoint of reduction, two or more types of structural units having different m values, preferably two types of structural units having different m values may be included. In that case, it is preferable to include both the structural units having m of 0 and 1 from the viewpoint that the optical laminate easily develops high surface hardness, elastic modulus, bending resistance, and low yellowness (YI value).

In a preferred embodiment of the present invention, formula (3) is a structural unit or formula (3') in which m = 0, R ^{1 to} R ⁸ are hydrogen atoms:

で表される構成単位であり、これを併用することもできる。この場合、ポリアミド系樹脂を含んでなる光学積層体は、高い表面硬度を発揮すると同時に、弾性率が低く、高い柔軟性を有することができる。

It is a structural unit represented by, and this can be used together. In this case, the optical laminate containing the polyamide resin can exhibit high surface hardness, and at the same time, have a low elastic modulus and high flexibility.

In a preferred embodiment of the present invention, the structural unit represented by the formula (3) when m is 0 to 4 is preferably 20 mol% or more, based on the total of Y and Z of the polyamide resin. It is preferably 30 mol% or more, more preferably 40 mol% or more, particularly preferably 50 mol% or more, most preferably 60 mol% or more, preferably 90 mol% or less, and more preferably 85 mol% or less. More preferably, it is 80 mol% or less. When the structural unit represented by the formula (3) when m is 0 to 4 with respect to the total of Y and Z in the polyamide resin is not more than the above lower limit value, the optical lamination including the polyamide resin is formed. The body can exhibit high surface hardness, low elastic modulus, and excellent flexibility. When the structural unit represented by the formula (3) when m is 0 to 4 with respect to the total of Y and Z in the polyamide resin is not more than the above upper limit value, the amide bonds derived from the formula (3) are separated. By suppressing the thickening due to hydrogen bonds, the viscosity of the polyamide-based resin varnish described later can be suppressed, and the processing of the optical laminate can be facilitated.

In a preferred embodiment of the present invention, the structural unit represented by the formula (3) when m is 1 to 4 with respect to the total of Y and Z of the polyamide resin is preferably 3 mol% or more. It is preferably 5 mol% or more, more preferably 7 mol% or more, particularly preferably 9 mol% or more, preferably 90 mol% or less, more preferably 70 mol% or less, still more preferably 50 mol% or less, particularly preferably. Is less than 30 mol%. When the structural unit represented by the formula (3) when m is 1 to 4 with respect to the total of Y and Z in the polyamide resin is not more than the above lower limit value, the optical lamination including the polyamide resin is formed. The body can exhibit high surface hardness, low elastic modulus, and excellent flexibility. When the surface hardness is high, the optical laminate, particularly the base material, is not easily scratched, and as a result, the yield of the product is improved, which can contribute to energy saving. When the structural unit represented by the formula (3) when m is 1 to 4 with respect to the total of Y and Z in the polyamide resin is not more than the above upper limit value, the amide bonds derived from the formula (3) are separated. By suppressing the thickening due to hydrogen bonds, the viscosity of the polyamide-based resin varnish described later can be suppressed, and the processing of the optical laminate can be facilitated.

In a preferred embodiment of the present invention, when Z in the above-mentioned polyamide resin is preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70 mol% or more, and m is 0 to 4. It is represented by the formula (3). When the above lower limit value or more of Z of the polyamide resin is represented by the formula (3) when m is 1 to 4, the optical laminate containing the polyamide resin exhibits high surface hardness and at the same time is elastic. It has a low rate and can have high flexibility. Further, it is preferable that 100 mol% or less of Z in the polyamide resin is represented by the formula (3) when m is 0 to 4. When the above upper limit value or less of Z of the polyamide resin is represented by the formula (3) when m is 0 to 4, the thickening due to the hydrogen bond between the amide bonds derived from the formula (3) is suppressed. The viscosity of the polyamide-based resin varnish described later can be suppressed, and the processing of the optical laminate can be facilitated. The ratio of the structural units represented by the formula (3) in the polyamide resin can be measured using, for example, ^{1 1} H-NMR, or can be calculated from the raw material charging ratio.

In a preferred embodiment of the present invention, Z in the above-mentioned polyamide resin is preferably 5 mol% or more, more preferably 8 mol% or more, still more preferably 10 mol% or more, and particularly preferably 12 mol% or more. It is represented by the formula (3) when m is 1 to 4. When the above lower limit value or more of Z of the polyamide resin is represented by the formula (3) when m is 1 to 4, the optical laminate containing the polyamide resin exhibits high surface hardness and at the same time is elastic. It has a low rate and can have high flexibility. Further, when Z in the polyamide resin is preferably 90 mol% or less, more preferably 70 mol% or less, further preferably 50 mol% or less, particularly preferably 30 mol% or less, and m is 1 to 4. It is preferably represented by the formula (3). When the above upper limit value or less of Z of the polyamide resin is represented by the formula (3) when m is 1 to 4, the thickening due to the hydrogen bond between the amide bonds derived from the formula (3) is suppressed. The viscosity of the polyamide-based resin varnish described later can be suppressed, and the processing of the optical laminate can be facilitated. The ratio of the structural units represented by the formula (3) in the polyamide resin can be measured using, for example, ^{1 1} H-NMR, or can be calculated from the raw material charging ratio.

In the formulas (1) and (2), X independently represents a divalent organic group, and preferably the hydrogen atom in the organic group is substituted with a hydrocarbon group or a hydrocarbon group substituted with fluorine. Is also a good organic group. The polyamide resin according to one embodiment of the present invention may contain a plurality of types of X, and the plurality of types of X may be the same as or different from each other. As X, it is represented by the formula (10), the formula (11), the formula (12), the formula (13), the formula (14), the formula (15), the formula (16), the formula (17) and the formula (18). Groups; Groups in which the hydrogen atom in the groups represented by the formulas (10) to (18) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and a chain having 6 or less carbon atoms. The formula hydrocarbon group is exemplified.

In equations (10) to (18), * represents a bond,
V ^{1, V 2} and ^{V 3} each independently represent a single _{bond, -O -, - S -,} - CH 2 -, - CH 2 -CH 2 -, - CH (CH 3) -, - C (CH ₃ ) Represents _2- , -C (CF ₃ ) _2- , -SO _2- , -CO- or -N (Q)-. Here, Q represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom, and specific examples thereof include the same groups as those listed in R ^9.
In one example, V ¹ and V ³ are single bonds, -O- or S-, and V ² is -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- Or -SO _2- . 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, preferably in the meta position or para position with respect to each ring, and more preferably in the para position. The rank.

Among the groups represented by the above formulas (10) to (18), they are represented by the formulas (13) to (17) from the viewpoint of the surface hardness and flexibility of the optical laminate containing the polyamide resin. The groups represented by the formulas (14) to (16) are more preferable. Further, V ¹ , V ² and V ³ are independently, preferably single-bonded, -O- or -S-, respectively, from the viewpoint of the surface hardness and flexibility of the optical laminate containing the polyamide resin. Yes, more preferably a single bond or -O-.

In a preferred embodiment of the present invention, at least a part of the plurality of Xs in the formulas (1) and (2) is the formula (4) :.

［式（４）中、Ｒ^１０〜Ｒ^１７は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基又は炭素数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、それぞれ独立に、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（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、ポリアミド系樹脂を含んでなる光学積層体は、高い表面硬度を発現できると同時に、高い透明性を発現することができる。

[In formula (4), R ^{10 to} R ¹⁷ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and hydrogen contained in R ^{10 to} R ¹⁷ is contained. Atoms may be independently substituted with halogen atoms, with * representing 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 optical laminate containing the polyamide resin can exhibit high surface hardness. At the same time, high transparency can be exhibited.

In the formula (4), R ^{10 to} R ¹⁷ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms include those exemplified as the alkyl group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms in the formula (3). R ^{10 to} R ¹⁷ independently represent hydrogen atoms or alkyl groups having 1 to 6 carbon atoms, more preferably hydrogen atoms or alkyl groups having 1 to 3 carbon atoms, and here, R ¹⁰ to R ¹⁷ The hydrogen atom contained in R ¹⁷ may be independently substituted with a halogen atom. R ^{10 to} R ¹⁷ are each independently, from the viewpoint of surface hardness, transparency and flexibility of the optical laminate containing the polyamide resin, more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group or a hydrogen atom. It is a trifluoromethyl group, particularly preferably a hydrogen atom or a trifluoromethyl group.

In a preferred embodiment of the present invention, the structural unit represented by the formula (4) is the formula (4'):

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、該ポリアミド系樹脂を含んでなる光学積層体は、高い透明性を発現すると同時に、フッ素元素を含有する骨格により該ポリアミド系樹脂の溶媒への溶解性を向上し、ポリアミド系樹脂ワニスの粘度を低く抑制することができ、光学積層体の加工を容易にすることができる。

That is, at least a part of the plurality of Xs is a structural unit represented by the equation (4'). In this case, the optical laminate containing the polyamide resin exhibits high transparency, and at the same time, the skeleton containing a fluorine element improves the solubility of the polyamide resin in a solvent, so that the polyamide resin varnish The viscosity can be suppressed low, and the processing of the optical laminate can be facilitated.

In a preferred embodiment of the present invention, the formula (4), particularly preferably 70 mol% or more, is preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70 mol% or more of X in the above-mentioned polyamide resin. It is represented by (4'). When X within the above range in the above-mentioned polyamide-based resin is represented by the formula (4), particularly the formula (4'), the optical laminate containing the polyamide-based resin exhibits high transparency and at the same time exhibits a fluorine element. The skeleton containing the above can improve the solubility of the polyamide resin in a solvent, suppress the viscosity of the polyamide resin varnish to be low, and facilitate the processing of the optical laminate. It should be noted that preferably, 100 mol% or less of X in the above-mentioned polyamide resin is represented by the formula (4), particularly the formula (4'). X in the above-mentioned polyamide resin may be of the formula (4), particularly the formula (4'). The ratio of the structural units represented by the formula (4) of X in the above-mentioned polyamide resin can be measured using, for example, ^{1 1} H-NMR, or can be calculated from the raw material charging ratio.

In the formula (1), Y independently represents a tetravalent organic group, preferably an organic group in which the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. Is. The polyamide resin according to one embodiment of the present invention may contain 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 formula (20), the formula (21), the formula (22), the formula (23), the formula (24), the formula (25), the formula (26), the formula (27), the formula (28) and the formula Groups represented by (29); groups in which the hydrogen atom in the groups represented by the formulas (20) to (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and 4 A chain hydrocarbon group having a valence of 6 or less carbon atoms is exemplified.

In equations (20) to (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 it represents -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 the groups represented by the formulas (20) to (29), the formulas (26), (28) and (29) are used from the viewpoint of the surface hardness and flexibility of the optical laminate containing the polyamide resin. ) Is preferable, and the group represented by the formula (26) is more preferable. Further, ^{W 1,} from the viewpoint of surface hardness and flexibility of the optical stack comprising said polyamide resin, each independently, a single _{bond, -O -, - CH 2 -} , - CH 2 -CH 2 - , -CH (CH ₃ )-, -C (CH ₃ ) _2- or -C (CF ₃ ) _2- , preferably single bond, -O-, -CH _2- , -CH (CH ₃ ) −, −C (CH ₃ ) ₂ − or −C (CF ₃ ) ₂ − is more preferred, and single bond, −C (CH ₃ ) ₂ − or −C (CF ₃ ) ₂ −. More preferred.

In a preferred embodiment of the present invention, at least a part of the plurality of Ys in the formula (1) is the formula (5) :.

［式（５）中、Ｒ^１８〜Ｒ^２５は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基又は炭素数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、それぞれ独立に、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、ポリアミド系樹脂を含んでなる光学積層体は、高い透明性を発現すると同時に、高い屈曲性骨格に由来して、ポリアミド系樹脂の溶媒への溶解性を向上し、ポリアミド系樹脂ワニスの粘度を低く抑制することができ、また光学積層体の加工を容易にすることができる。

[In formula (5), R ^{18 to} R ²⁵ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and hydrogen contained in R ^{18 to} R ^25. Atoms 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 Ys in the formula (1) is a group represented by the formula (5), the optical laminate containing the polyamide resin exhibits high transparency and at the same time has high flexibility. Derived from the skeleton, the solubility of the polyamide resin in a solvent can be improved, the viscosity of the polyamide resin varnish can be suppressed to a low level, and the processing of the optical laminate can be facilitated.

In the formula (5), R ^{18 to} R ²⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms include those exemplified as the alkyl group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms in the formula (3). Each of R ^{18 to} R ²⁵ independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having a hydrogen atom or 1 to 3 carbon atoms, and here, R ¹⁸ to R ²⁵ are represented. The hydrogen atom contained in R ²⁵ may be independently substituted with a halogen atom. From the viewpoint of surface hardness and flexibility of the optical laminate containing the polyamide resin, R ^{18 to} R ²⁵ are more preferably hydrogen atoms, methyl groups, fluoro groups, chloro groups or trifluoromethyl. It is a group, particularly preferably a hydrogen atom or a trifluoromethyl group.

In a preferred embodiment of the present invention, the structural unit represented by the formula (5) is the formula (5'):

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、該ポリアミド系樹脂を含んでなる光学積層体は、高い透明性を有することができる。

It is a group represented by, that is, at least a part of a plurality of Ys is a structural unit represented by the formula (5'). In this case, the optical laminate containing the polyamide resin can have high transparency.

In a preferred embodiment of the present invention, Y in the above-mentioned polyamide resin is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol% or more of the formula (5), particularly the formula (5). It is represented by'). When Y in the above range in the above-mentioned polyamide-based resin is represented by the formula (5), particularly the formula (5'), the optical laminate containing the polyamide-based resin can have high transparency, and further. The skeleton containing a fluorine element improves the solubility of the polyamide resin in a solvent, suppresses the viscosity of the polyamide resin varnish to be low, and facilitates the production of an optical laminate. It should be noted that preferably, 100 mol% or less of Y in the above-mentioned polyamide resin is represented by the formula (5), particularly the formula (5'). Y in the above-mentioned polyamide resin may be the formula (5), particularly the formula (5'). The ratio of the structural units represented by the formula (5) of Y in the above-mentioned polyamide resin can be measured using, for example, ^{1 1} H-NMR, or can be calculated from the raw material charging ratio.

In the polyamide resin, the weight average molecular weight in terms of standard polystyrene is preferably 5,000 or more, more preferably 10,000 or more, further preferably 50,000 or more, particularly preferably 100,000 or more, and most preferably 150. It is 000 or more, preferably 800,000 or less, more preferably 600,000 or less, still more preferably 500,000 or less. When the weight average molecular weight of the polyamide resin is at least the above lower limit value, the optical laminate containing the polyamide resin has even better bending resistance. Further, when the weight average molecular weight of the polyamide resin is not more than the above upper limit value, the viscosity of the polyamide resin varnish can be suppressed to be low, and the optical laminate, particularly the base film, can be easily stretched. The property becomes good. In the present specification, the weight average molecular weight can be obtained by, for example, GPC measurement and standard polystyrene conversion, and specifically, can be obtained by the method described in Examples.

In the above polyamideimide, the content of the structural unit represented by the formula (2) is preferably 0.1 mol or more, more preferably 0.5 mol, with respect to 1 mol of the structural unit represented by the formula (1). It is mol or more, more preferably 1.0 mol or more, particularly preferably 1.5 mol or more, preferably 3.9 mol or less, more preferably 3.0 mol or less, still more preferably 2.5 mol or less. .. When the content of the structural unit represented by the formula (2) is at least the above lower limit value, the optical laminate containing the polyamide resin can exhibit higher surface hardness. Further, when the content of the structural unit represented by the formula (2) is not more than the above upper limit value, the thickening due to the hydrogen bond between the amide bonds in the formula (2) is suppressed, and the viscosity of the polyamide resin varnish is increased. It can be reduced and the production of the optical laminate is easy.

The polyamide resin contains, in addition to the structural units represented by the formulas (1) and (2), the structural units represented by the formula (30) and / or the structural units represented by the formula (31). be able to.

In the formula (30), Y ¹ is an independently tetravalent organic group, preferably an organic in which the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a hydrocarbon group substituted with fluorine. It is a group. Examples of Y ¹ include formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) and Examples thereof include a group represented by the formula (29) and a chain hydrocarbon group having a tetravalent carbon number of 6 or less. Polyamideimide one which is an embodiment of the present invention may include a plurality of kinds of Y ^1, Y ¹ of the plurality of kinds may identical to one another or may be different.

In the formula (31), Y ² is a trivalent organic group, preferably an organic group in which the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a hydrocarbon group substituted with fluorine. Examples of Y ² include formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) and Examples thereof include a group in which any one of the bonds of the group represented by the formula (29) is replaced with a hydrogen atom, and a chain hydrocarbon group having a trivalent carbon number of 6 or less. Polyamideimide which is an embodiment of the present invention may include a plurality of kinds of Y ^2, Y ² of plural types may identical to one another or may be different.

In formulas (30) and (31), X ¹ and X ² are independently divalent organic groups, preferably hydrocarbon groups in which hydrogen atoms in the organic groups are hydrocarbon groups or fluorine-substituted hydrocarbon groups. It is an organic group that may be substituted with. Examples of X ¹ and X ² are groups represented by the formulas (10) to (18); the hydrogen atoms in the groups represented by the formulas (10) to (18) are methyl group, fluoro group, and chloro. Groups substituted with groups or trifluoromethyl groups; as well as chain hydrocarbon groups with 6 or less carbon atoms are exemplified.

In one embodiment of the present invention, the polyamide-imide is derived from the structural units represented by the formulas (1) and (2), and optionally the structural units represented by the formulas (30) and / or the formula (31). Become. Further, from the viewpoint of the surface hardness and flexibility of the optical laminate containing the polyamide-imide, the structural units represented by the formulas (1) and (2) in the above-mentioned polyamide-imide are the formulas (1) and the formulas. (2), and optionally based on all the structural units represented by the formulas (30) and (31), preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more. is there. In the above polyamide-imide, the structural units represented by the formulas (1) and (2) are represented by the formulas (1) and (2), and in some cases, the formulas (30) and (31). Usually 100% or less based on all constituent units. The above ratio can be measured using, for example, ^{1 1} H-NMR, or can be calculated from the raw material charging ratio.

In the polyamide-based resin, the polyamide can be produced, for example, using a dicarboxylic acid compound and a diamine compound described later as main raw materials, and the polyamide-imide is mainly composed of, for example, a tetracarboxylic acid compound, a dicarboxylic acid compound and a diamine compound described later. Can be manufactured as a raw material. Here, the dicarboxylic acid compound preferably contains at least a compound represented by the formula (3 ").

［式（３”）中、Ｒ^１〜Ｒ^８は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基又は炭素数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、それぞれ独立に、ハロゲン原子で置換されていてもよく、
Ａは、−Ｏ−、−Ｓ−、−ＣＯ−又は−Ｎ（Ｒ^９）−を表し、Ｒ^９は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、それぞれ独立に、−ＯＨ、−ＯＣＨ_３、−ＯＣＨ_２ＣＨ_３、−ＯＣＨ_２ＣＨ_２ＣＨ_３、−ＯＣＨ（ＣＨ_３）_２、−ＯＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_３、−ＯＣＨ（ＣＨ_３）ＣＨ_２ＣＨ_３、−ＯＣＨ_２ＣＨ（ＣＨ_３）_２、−ＯＣ（ＣＨ_３）_３又はＣｌを表す］

[In the formula (3 ″), R ^{1 to} R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and are included in R ^{1 to} R ^8. Each hydrogen atom may be independently substituted with a halogen atom,
A represents -O-, -S-, -CO- or -N (R ⁹ )-, and R ⁹ is a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Represent,
m is an integer from 0 to 4
R ³¹ and R ³² are independently of -OH, -OCH ₃ , -OCH ₂ CH ₃ , -OCH ₂ CH ₂ CH ₃ , -OCH (CH ₃ ) ₂ , -OCH ₂ CH ₂ CH ₂ CH ₃ , respectively. -OCH (CH ₃ ) CH ₂ CH ₃ , -OCH ₂ CH (CH ₃ ) ₂ , -OC (CH ₃ ) ₃ or Cl]

In a preferred embodiment, the dicarboxylic acid compound is a compound represented by the formula (3 "), where A is —O—, and in another preferred embodiment, the dicarboxylic acid compound is R. It is a compound represented by the formula (3 ″) in which ³¹ and R ³² are −Cl, respectively. Further, a diisocyanate compound may be used instead of the diamine compound.

Examples of the tetracarboxylic acid compound used for the synthesis of the polyamide resin include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic dianhydride; and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydride. Can be mentioned. The tetracarboxylic acid compound may be used alone or in combination of two or more. The tetracarboxylic dian compound may be a tetracarboxylic dian compound analog such as an acid chloride compound in addition to the dianhydride.

Specific examples of aromatic tetracarboxylic dianhydrides include non-condensed polycyclic aromatic dianhydrides, monocyclic aromatic tetracarboxylic dianhydrides, and condensed polycyclic aromatic dianhydrides. Examples include carboxylic dianhydride. Examples of the non-condensed polycyclic aromatic tetracarboxylic dianhydride include 4,4'-oxydiphthalic acid dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride and 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) Describe as carboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA). (There is), 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) Examples thereof include −dicarboxyphenyl) methane dianhydride, 4,4'-(p-phenylenedioxy) diphthalic acid dianhydride, and 4,4'-(m-phenylenedioxy) diphthalic acid dianhydride. Examples of the monocyclic aromatic tetracarboxylic dianhydride include 1,2,4,5-benzenetetracarboxylic dianhydride, and the condensed polycyclic aromatic tetracarboxylic dianhydride. Examples thereof include 2,3,6,7-naphthalenetetracarboxylic dianhydride.
Among these, preferably 4,4'-oxydiphthalic acid dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2', 3,3'-benzophenonetetracarboxylic dianhydride. Anhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-diphenyl Sulfontetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2- Bis (3,4-dicarboxyphenoxyphenyl) propanedianhydride, 4,4'-(hexafluoroisopropyridene) diphthalic acid dianhydride (6FDA), 1,2-bis (2,3-dicarboxyphenyl) Etan 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-) Examples thereof include 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 acid dianhydride (6FDA) , Bis (3,4-dicarboxyphenyl) methane dianhydride and 4,4'-(p-phenylenedioxy) diphthalic dianhydride. These can be used alone or in combination of two or more.

Examples of the aliphatic tetracarboxylic dianhydride include cyclic or acyclic aliphatic tetracarboxylic dianhydride. The cyclic aliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having an alicyclic hydrocarbon structure, and specific examples thereof include 1,2,4,5-cyclohexanetetracarboxylic dianhydride. Cycloalkanetetracarboxylic dianhydride such as 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2.2] .2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl3,3'-4,4'-tetracarboxylic dianhydride and their positional isomers can be mentioned. .. 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, 1,2,3,4-pentanetetracarboxylic dianhydride and the like. These can be used alone or in combination of two or more. Further, a cyclic aliphatic tetracarboxylic dianhydride and an acyclic aliphatic tetracarboxylic dianhydride may be used in combination.

Among the above tetracarboxylic dianhydrides, 4,4'-oxydiphthalic dianhydride, 3 from the viewpoints of high surface hardness, high transparency, high flexibility, high bending resistance, and low coloring property of the optical laminate. , 3', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride Anhydroide, 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 4,4'-(hexafluoroisopropi) Liden) diphthalic dianhydride, and mixtures thereof, are preferred, 3,3', 4,4'-biphenyltetracarboxylic dianhydride and 4,4'-(hexafluoroisopropyridene) diphthalic dianhydride, And a mixture thereof is more preferable, and 4,4'-(hexafluoroisopropyridene) diphthalic acid dianhydride is further preferable.

Examples of the dicarboxylic acid compound used in the synthesis of the polyamide resin include aromatic dicarboxylic acids, aliphatic dicarboxylic acids and their related acid chloride compounds, acid anhydrides, and the like, and two or more of them may be used in combination. Specific examples include a dicarboxylic acid compound of terephthalic acid; isophthalic acid; naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; a chain hydrocarbon having 8 or less carbon atoms, and 2 Compounds in which one benzoic acid is single-bonded, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO _2- or a phenylene group, and their acid chloride compounds Can be mentioned. Among these dicarboxylic acid compounds, 4,4'-oxybis benzoic acid, terephthalic acid, and their acid chlorides are preferable, and 4,4'-oxybis (benzoyl chloride) and terephthaloyl chloride are preferable, and 4,4'. -A combination of oxybis (benzoyl chloride) and terephthaloyl chloride is more preferred.

The above-mentioned polyamide-based resin includes tetracarboxylic acid and tricarboxylic acid in addition to the above-mentioned tetracarboxylic acid compound used for the synthesis of the above-mentioned polyamide-based resin, as long as the various physical properties of the optical laminate containing the polyamide-based resin are not impaired. Acids and their anhydrides and derivatives may be further reacted.

Examples of the tetracarboxylic acid include a water adduct of the anhydride of the tetracarboxylic acid compound.

Examples of the tricarboxylic acid compound include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, acid chloride compounds related thereto, acid anhydrides, and the like, and two or more of them may be used in combination.
Specific examples include an anhydride of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalentricarboxylic acid-2,3-anhydride; a single bond of phthalic anhydride and benzoic acid, -O- , -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO _2- or compounds linked by a phenylene group.

Examples of the diamine compound used in the synthesis of the polyamide resin include aliphatic diamines, aromatic diamines and mixtures thereof. In addition, in this embodiment, "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 contained in a part of the structure. The aromatic ring may be a monocyclic 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. Further, the "aliphatic diamine" represents a diamine in which an amino group is directly bonded to an aliphatic group, and an aromatic ring or other substituent may be contained as a part of the structure thereof.

Examples of the aliphatic diamine include an acyclic aliphatic diamine such as hexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, norbornanediamine and 4,4'. − Examples include 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-xylylene diamine, p-xylylene diamine, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene and the like. Aromatic amines 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-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 (with TFMB) (May be described), 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) fluorene, 9,9-bis (4-amino-3-fluorophenyl) fluorene, and other aromatic diamines having two or more aromatic rings. These can be used alone or in combination of two or more.

As the aromatic diamine, preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,3'-Diaminodiphenyl sulfone, 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-aminophenoxy) biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diamino Diphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 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 above diamine compounds, one selected from the group consisting of aromatic diamines having a biphenyl structure from the viewpoints of high surface hardness, high transparency, high flexibility, high bending resistance, and low colorability of the optical laminate. It is preferable to use the above. 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).

Polyamideimide, which is one embodiment of the present invention, includes diamine compounds, tetracarboxylic acid compounds (tetracarboxylic acid compound analogs such as acid chloride compounds and tetracarboxylic acid dianhydrides), and dicarboxylic acid compounds (acid chloride compounds, etc.). It is a condensed polymer which is a polycondensation product with a dicarboxylic acid compound analog) and, in some cases, a tricarboxylic acid compound (a tricarboxylic acid compound analog such as an acid chloride compound and a tricarboxylic acid anhydride). The structural units represented by the formulas (1) and (30) are usually derived from diamine and tetracarboxylic acid compounds. The structural unit represented by the formula (2) is usually derived from a diamine and a dicarboxylic acid compound. The structural unit represented by the formula (31) is usually derived from a diamine and a tricarboxylic acid compound.

In a preferred embodiment of the present invention, the polyamide resin may contain halogen atoms as described above. Specific examples of the fluorine-containing substituent include a fluoro group and a trifluoromethyl group. When the polyamide resin contains halogen atoms, it may be possible to reduce the yellowness (YI value) of the optical laminate containing the polyamide resin, and it is possible to achieve both high flexibility and bending resistance. There is a tendency to be able to do it. Further, the halogen atom is preferably a fluorine atom from the viewpoint of reducing the yellowness of the optical laminate, that is, improving the transparency, reducing the water absorption rate, and bending resistance.

The content of the halogen atom in the polyamide resin is preferably 1 from the viewpoint of reducing yellowness, that is, improving transparency, reducing water absorption, and suppressing deformation of the optical laminate, based on the mass of the polyamide resin. It is ~ 40% by mass, more preferably 3 to 35% by mass, still more preferably 5 to 32% by mass.

In one embodiment of the present invention, an imidization catalyst may be present in the synthesis reaction of the polyamide-based resin (polyamideimide). Examples of imidization catalysts include aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; N-ethylpiperidin, N-propylpiperidin, N-butylpyrrolidin, N-butylpiperidin, and N-propylhexahydro. Alicyclic amines such as azepine (monocyclic); azabicyclo [2.2.1] heptane, azabicyclo [3.2.1] octane, azabicyclo [2.2.2] octane, and azabicyclo [3.2. 2] Alicyclic amines such as nonane (polycyclic); and pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2, Examples include aromatic amines such as 4-dimethylpyridine, 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and isoquinoline.

The reaction temperature of the diamine compound, the tetracarboxylic acid compound and the dicarboxylic acid compound is not particularly limited, but is, for example, 50 to 350 ° C. The reaction time is also not particularly limited, but is, for example, about 30 minutes to 10 hours. If necessary, the reaction may be carried out under conditions of an inert atmosphere or reduced pressure. The reaction may be carried out in a solvent, and examples of the solvent include a solvent used for preparing a polyamide-based resin varnish, which will be described later.

(Aromatic compound)
The aromatic compound may be a compound having one or more aromatic hydrocarbon rings which may have a substituent. For example, the aromatic hydrocarbon ring is a monocyclic hydrocarbon ring such as a benzene ring. Examples thereof include a fused bicyclic hydrocarbon ring such as naphthalene and a polycyclic hydrocarbon ring such as a ring-assembled hydrocarbon ring such as benzene. Further, the substituent includes, for example, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and an alkyl group having 1 to 6 carbon atoms in the above formula (3), which has 1 to 6 carbon atoms similar to those exemplified. Examples thereof include an alkyl group, a phenyl group, a nitro group, a cyano group, a hydroxyl group, and a phenyloxy group of 6. These substituents may be substituted with one or more of the above aromatic hydrocarbon rings.

In the present invention, since the base film contains the polyamide resin and the aromatic compound, an optical laminate having excellent surface hardness of the hard coat layer can be obtained. This is because the hardness of the base film increases due to the entry of the aromatic compound into the space in the crosslinked structure formed by the hydrogen bonds between the amide bonds of the polyamide resin contained in the base film, and as a result, the hard coat layer It is presumed that this is because the surface hardness of is improved.

The aromatic compound is preferably an ultraviolet absorber. When an ultraviolet absorber is used as the aromatic compound contained in the base film, the surface hardness of the hard coat layer in the optical laminate can be further improved.

Examples of the ultraviolet absorber include a triazine derivative (triazine-based ultraviolet absorber) such as a benzotriazole derivative (benzotriazole-based ultraviolet absorber), a 1,3,5-triphenyltriazine derivative, and a benzophenone derivative (benzophenone-based ultraviolet absorber). ), And a salicylate derivative (salicylate-based ultraviolet absorber), and at least one selected from the group consisting of these can be used. Since the surface hardness of the optical laminate is improved, it has a good ultraviolet absorbing ability in the range of 370 to 400 nm, and the polarizing plate can be protected when it is laminated with a polarizing plate, a benzotriazole-based ultraviolet absorber and a triazine-based ultraviolet ray are used. It is preferable to use at least one selected from the group consisting of absorbents, and benzotriazole-based ultraviolet absorbers are more preferable.

Specific examples of the benzotriazole-based ultraviolet absorber include a compound represented by the formula (I) and a trade name manufactured by Sumitomo Chemical Co., Ltd.: Sumisorb (registered trademark) 250 (2- [2-hydroxy-3- (3)). , 4,5,6-tetrahydrophthalimide-methodiyl) -5-methylphenyl] benzotriazole), trade name manufactured by BASF Japan Co., Ltd .: Tinuvin® 360 (2,2'-methylenebis [6- (2H) -Benzotriazole-2-yl) -4-tert-octylphenol]) and Tinuvin 213 (methyl 3- [3- (2H-benzotriazole-2-yl) 5-tert-butyl-4-hydroxyphenyl] propionate and PEG300 (Reaction products with), and these can be used alone or in combination of two or more. Specific examples of the compound represented by the formula (I) include trade names: Sumisorb 200 (2- (2-hydroxy-5-methylphenyl) benzotriazole) manufactured by Sumitomo Chemical Co., Ltd., Sumisorb 300 (2- (3). -Tart-butyl-2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole), Sumisorb 340 (2- (2-hydroxy-5-tert-octylphenyl) benzotriazole), Sumisorb 350 (2- (2) -Hydroxy 3,5-di-tert-pentylphenyl) benzotriazole), and brand name: Tinuvin 327 (2- (2'-hydroxy-3', 5'-di-tert-butyl) manufactured by BASF Japan Co., Ltd. Phenyl) -5-chlorobenzotriazole), Tinuvin 571 (2- (2H-benzotriazo-2-yl) -6-dodecyl-4-methyl-phenol) and Tinuvin 234 (2- (2H-benzotriazole-2-yl)) ) -4,6-bis (1-methyl-1-phenylethyl) phenol) and ADEKA Co., Ltd. Product name: Adecastab (registered trademark) LA-31 (2,2'-methylenebis [6- (2H-benzo) Triazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol]) can be mentioned. The ultraviolet absorber is preferably a compound represented by the formula (I) and Tinuvin 213 (methyl 3- [3- (2H-benzotriazole-2-yl) 5-tert-butyl-4-hydroxyphenyl] propionate. It is a reaction product with PEG300, more preferably a trade name manufactured by Sumitomo Chemical Co., Ltd .: Sumisorb 200 (2- (2-hydroxy-5-methylphenyl) benzotriazole), Sumisorb 300 (2- (3-tert). -Butyl-2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole), Sumisorb 340 (2- (2-hydroxy-5-tert-octylphenyl) benzotriazole), Sumisorb 350 (2- (2-hydroxy) 3,5-Di-tert-Pentylphenyl) benzotriazole), Product name of ADEKA Co., Ltd .: Adecastab LA-31 (2,2'-methylenebis [6- (2H-benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol]) and trade name manufactured by BASF Japan Co., Ltd .: Tinuvin 327 (2- (2'-hydroxy-3', 5'-di-tert-butylphenyl) )-5-Chlorobenzotriazole) and Tinuvin 571 (2- (2H-benzotriazo-2-yl) -6-dodecyl-4-methyl-phenol), most preferably trade names manufactured by Sumitomo Chemical Co., Ltd .: Sumisorb 340 (2- (2-hydroxy-5-tert-octylphenyl) benzotriazole), Sumisorb350 (2- (2-hydroxy 3,5-di-tert-pentylphenyl) benzotriazole), and ADEKA Co., Ltd. Product name: Adecastab LA-31 (2,2'-methylenebis [6- (2H-benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol]).

In the formula (I), ^XI is a hydrogen atom, a fluorine atom, a chlorine atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, and ^RI1 and ^RI2 are independently hydrogen atoms. or a hydrocarbon group having 1 to 20 carbon ^atoms, at least one of ^{R I1} or ^{R I2} is a hydrocarbon group having 1 to 20 carbon atoms.

The alkyl group of 1 to 5 carbon atoms for X ^I, methyl, ethyl, n- propyl group, an isopropyl group, n- butyl group, sec- butyl group, tert- butyl group, n- pentyl group, 2- Examples thereof include a methyl-butyl group, a 3-methylbutyl group, and a 2-ethyl-propyl group.
The alkoxy group of 1 to 5 carbon atoms for X ^I, a methoxy group, an ethoxy group, n- propoxy group, isopropoxy group, n- butoxy group, sec- butoxy group, tert- butoxy group, n- pentyloxy group, Examples thereof include 2-methyl-butoxy group, 3-methylbutoxy group and 2-ethyl-propoxy group.
^XI is preferably a hydrogen atom, a fluorine atom, a chlorine atom or a methyl group, and more preferably a hydrogen atom, a fluorine atom or a chlorine atom.

R ^I1 and R ^I2 are independently hydrogen atoms or hydrocarbon groups having 1 to 20 carbon atoms, and at least one of R ^I1 and R ^{I 2} is a hydrocarbon group. When R ^I1 and R ^I2 are hydrocarbon groups, respectively, they are preferably hydrocarbon groups having 1 to 12 carbon atoms, and more preferably hydrocarbon groups having 1 to 8 carbon atoms. Specific examples thereof include a methyl group, a tert-butyl group, a tert-pentyl group and a tert-octyl group.

As the ultraviolet absorber according to another preferred embodiment, a triazine-based ultraviolet absorber is used in the optical laminate containing the polyamide-based resin. Examples of the triazine-based ultraviolet absorber include compounds represented by the following formula (II). As a specific example, the product name of ADEKA Co., Ltd .: Adecastab LA-46 (2- (4,6-diphenyl-1,3,5-triazine-2-yl) -5- [2- (2-ethyl) Hexaneuroxy) ethoxy] phenol), trade name manufactured by BASF Japan Co., Ltd .: Tinuvin 400 (2- [4- [2-hydroxy-3-tridecyloxypropyl] oxy] -2-hydroxyphenyl] -4,6 -Bis (2,4-dimethylphenyl) -1,3,5-triazine), 2- [4- [2-hydroxy-3-didecyloxypropyl] oxy] -2-hydroxyphenyl] -4,6-bis (2,4-Dimethylphenyl) -1,3,5-triazine), Tinuvin 405 (2- [4 (2-hydroxy-3- (2'-ethyl) hexyl) oxy] -2-hydroxyphenyl] -4 , 6-bis (2,4-dimethylphenyl) -1,3,5-triazine), Tinuvin 460 (2,4-bis (2-hydroxy-4-butyloxyphenyl) -6- (2,4-bis) -Butyloxyphenyl) -1,3,5-triazine), Tinuvin 479 (hydroxyphenyltriazine-based ultraviolet absorber), and Chemipro Kasei Co., Ltd. product name: KEMISORB (registered trademark) 102 (2- [4,6) -Bis (2,4-dimethylphenyl) -1,3,5-triazine-2-yl] -5- (n-octyloxy) phenol) and the like, which are used alone or in combination of two or more. be able to. The compound represented by the formula (II) is preferably Adecastab LA-46 (2- (4,6-diphenyl-1,3,5-triazine-2-yl) -5- [2- (2-ethyl). Hexaneuroxy) ethoxy] phenol).

In the formula (II), Y ^{I1 to} Y ^I4 are independently hydrogen atom, fluorine atom, chlorine atom, hydroxy group, alkyl group having 1 to 20 carbon atoms or alkoxy group having 1 to 20 carbon atoms, and are preferable. Is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, and more preferably a hydrogen atom.

In formula (II), ^RI3 is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms containing one oxygen atom, or an alkyl ketooxy having 1 to 12 carbon atoms. It is an alkoxy group having 1 to 4 carbon atoms substituted with a group, and is preferably substituted with an alkoxy group having 1 to 12 carbon atoms containing one oxygen atom or an alkyl ketooxy group having 8 to 12 carbon atoms. It is an alkoxy group having 2 to 4 carbon atoms, and more preferably an alkoxy group having 2 to 4 carbon atoms substituted with an alkyl ketooxy group having 8 to 12 carbon atoms.

Examples of alkyl groups having 1 to 20 carbon atoms as Y ^{I1 to} Y ^I4 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group and n. Examples thereof include -pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group and n-undecyl group.

In one embodiment, the ultraviolet absorber is preferably one that is easily dissolved in N, N-dimethylacetamide (hereinafter, may be referred to as DMAc), which has high solubility in a polyamide resin. Such an ultraviolet absorber may be a compound that dissolves 1.0 g or more in 100 g of DMAc at 25 ° C., that is, has a solubility in DMAc at 25 ° C. of 1.0 g / 100 g or more. The solubility of the ultraviolet absorber is preferably 5 g / 100 g or more, and more preferably 10 g / 100 g or more with respect to a solvent such as DMAc. The upper limit of the solubility of the ultraviolet absorber is not limited, and may be, for example, 100 g / 100 g. Since the ultraviolet absorber having high solubility in DMAc is easily homogenized with the polyamide resin, the surface hardness of the optical laminate can be improved, and it has high transparency and high ultraviolet absorption ability, and further coloring and the like. It can also be prevented.

The ultraviolet absorber preferably has an ultraviolet absorption property such that the light transmittance of the base film at 390 nm can be 35% or less, more preferably 25% or less, still more preferably 20% or less.

The content of the ultraviolet absorber in the base film is preferably 0.01 to 10 parts by mass, more preferably 1 to 8 parts by mass, and further preferably 3 to 7 parts by mass with respect to 100 parts by mass of the polyamide resin. Is. When the content of the ultraviolet absorber is at least the above lower limit value, the surface hardness of the optical laminate can be improved. Further, when the content of the ultraviolet absorber is not more than the above upper limit value, the yellowness of the optical laminate can be suppressed (YI value can be reduced), and the transparency of the optical laminate can be improved.

In the base film, the content of the polyamide resin is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 70% by mass or more, and particularly preferably 80% by mass with respect to the mass of the base film. % Or more, very preferably 90% by mass or more. When the content of the polyamide resin is at least the above lower limit value, the surface hardness and flexibility of the optical laminate are good. The content of the polyamide resin in the base film is usually less than 100% by mass based on the total mass of the base film.

From the viewpoint of easily improving the surface hardness of the optical laminate, the base film can further contain inorganic particles in addition to the polyamide resin and the aromatic compound. Examples of the inorganic particles include titania particles, alumina particles, zirconia particles, silica particles and the like. From the viewpoint of the stability of the polyamide-based resin varnish for producing the optical laminate and the improvement of the surface hardness of the optical laminate, the inorganic particles are particularly preferably silica particles. Inorganic particles may be bonded to each other by a molecule having a siloxane bond.

The average primary particle diameter of the inorganic particles is preferably 10 to 100 nm, more preferably 20 to 80 nm, from the viewpoint of transparency of the optical laminate, mechanical properties, and suppression of aggregation of the inorganic particles. In the present invention, the average primary particle size can be determined by measuring a 10-point average value of the directional diameter with a transmission electron microscope (TEM).

When the base film contains inorganic particles, the content of the inorganic particles in the optical laminate is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass with respect to the mass of the base film. It is mass% or more, particularly preferably 30 mass% or more, preferably 70 mass% or less, and more preferably 60 mass% or less. When the content of the inorganic particles is not less than the above lower limit value, it is advantageous to improve the surface hardness of the hard coat layer, and when it is not more than the above upper limit value, it is advantageous to reduce the YI value of the optical laminate.

The base film may further contain other additives. Examples of other additives include antioxidants, mold release agents, stabilizers, bluing agents, flame retardants, pH adjusters, silica dispersants, lubricants, thickeners, leveling agents and the like.

The content of the other additive is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, based on the mass of the base film.

The thickness of the base film is appropriately adjusted depending on the intended use, but is usually 10 to 200 μm, preferably 20 to 100 μm, more preferably 25 to 80 μm, and further preferably 30 to 50 μm. In the present invention, the thickness of the base film can be measured by, for example, the method described in Examples.

<Hard coat layer>
The optical laminate of the present invention has a hard coat layer on at least one surface of the base film.
The hard coat layer may be provided on one side or both sides of the base film.

Examples of the hard coat layer include known hard coat layers such as acrylic type, epoxy type, urethane type, benzyl chloride type, and vinyl type. Among these, an acrylic hard coat layer can be preferably used. The acrylic hard coat layer is preferably a cured product of a curable composition containing a curable compound. The curable compound is a compound that is polymerized and cured by irradiation with active energy rays, and examples thereof include polyfunctional (meth) acrylate compounds. The polyfunctional (meth) acrylate-based compound is a compound having at least two (meth) acryloyloxy groups in the molecule.

Examples of the polyfunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and tri. Methylolpropantri (meth) acrylate, trimethylolethanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaglyceroltri (meth) acrylate, pentaerythritol tri (meth) acrylate , Pentaerythritol tetra (meth) acrylate, glycerintri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) Acrylate, tris ((meth) acryloyloxyethyl) isocyanurate; phosphazenic (meth) acrylate compound in which a (meth) acryloyloxy group is introduced into the phosphazenic ring of the phosphazene compound; having at least two isocyanate groups in the molecule. Urethane (meth) acrylate compound obtained by reacting polyisocyanate with at least one (meth) acryloyloxy group and a polyol compound having a hydroxyl group; at least two carboxylic acid halides in the molecule and at least one (meth) ) A polyester (meth) acrylate compound obtained by reacting with a polyol compound having an acryloyloxy group and a hydroxyl group; and an oligomer such as a dimer or a trimer of each of the above compounds. These compounds are used alone or in admixture of two or more.

The curable compound may include a monofunctional (meth) acrylate compound in addition to the above-mentioned polyfunctional (meth) acrylate compound. Examples of the monofunctional (meth) acrylate-based compound 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 and the like can be mentioned. These compounds are used alone or in admixture 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 curable composition.

Moreover, the curable compound may contain a polymerizable oligomer. By containing the polymerizable oligomer, the hardness of the hard coat layer can be adjusted. Examples of the polymerizable oligomer 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, and terminal. Macromonomers such as (meth) acrylate styrene-methyl (meth) acrylate copolymers can be mentioned. The content of the polymerizable oligomer is preferably 5 to 50% by mass based on the solid content of the compound contained in the curable composition.

The curable composition may contain a polymerization initiator. Examples of the polymerization 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-morpholinopropane-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenylphosphenyl oxide, phenyl Bis (2,4,6-trimethylbenzoyl) -phosphine oxide, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, benzaldehyde, benzoin ethyl ether, benzo Isopropyl ether, benzophenone, Michler ketone, 3-methylacetophenone, 3,3', 4,4'-tetratert-butylperoxycarbonylbenzophenone (BTTB), 2- (dimethylamino) -1- [4- (morpholinyl) phenyl ] -2-Phenylmethyl) -1-butanone, 4-benzoyl-4'-methyldiphenylsulfide, benzyl, and derivatives thereof. These polymerization initiators may be used alone or in admixture of several types as required. The polymerization initiators exemplified above are all photopolymerization initiators that generate radicals by irradiation with active energy rays.

The content of the polymerization initiator is preferably 0.1 to 10 parts by mass, and more preferably 1 to 7 parts by mass with respect to 100 parts by mass of the curable compound. When the content of the polymerization initiator is in the above range, the curability of the curable composition becomes good, and the surface hardness of the hard coat layer can be increased.

The curable composition may contain the same UV absorber as described in the section <Base film>. When the hard coat layer contains an ultraviolet absorber, if the content of the ultraviolet absorber is excessive, the curability of the curable composition may be lowered, and as a result, the surface hardness of the hard coat layer may be lowered. Therefore, the content of the ultraviolet absorber in the hard coat layer is preferably less than 5.0 parts by mass, more preferably 2.0 parts by mass or less, still more preferably 0, with respect to 100 parts by mass of the curable composition. It is a mass part. In order to improve the surface hardness of the hard coat layer, it is advantageous to improve the curability of the curable composition forming the hard coat layer and to increase the hardness of the base film due to the inclusion of the ultraviolet absorber. Is. For this purpose, it is preferable that the content of the ultraviolet absorber contained in the base film is larger than the content of the ultraviolet absorber in the hard coat layer. The content of the ultraviolet absorber contained in the base film and the content of the ultraviolet absorber in the hard coat layer can be compared based on, for example, the total mass of the optical laminate.

The curable composition may contain a solvent in order to improve the coatability on the base film. Solvents include, for example, 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. Classes; esters such as ethyl acetate, butyl acetate, isobutyl acetate; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; ethylene glycol monomethyl It can be appropriately selected and used from esterified glycol ethers such as ether acetate and propylene glycol monomethyl ether acetate. These solvents can be used alone or in combination of two or more. The type and content of the solvent are appropriately selected according to the type and content of the curable compound used, the material and shape of the base film, the coating method, the thickness of the target hard coat layer, and the like.

The curable composition may further contain other additives. Examples of other additives include inorganic particles, antistatic agents, antioxidants, mold release agents, stabilizers, brewing agents, flame retardants, pH adjusters, and silica dispersions described in the section of <Base film>. Agents, lubricants, thickeners, leveling agents and the like can be mentioned. When the curable composition contains other additives, the content of the other additives is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, based on the mass of the curable composition. It is mass%.

The thickness of the hard coat layer is preferably 1 to 20 μm, more preferably 3 to 17 μm, and further preferably 5 to 15 μm from the viewpoint of achieving both bending resistance and pencil hardness of the optical laminate. The thickness of the hard coat layer can be measured by, for example, the method described in Examples.

The curable composition can be obtained by mixing the components contained in the composition, for example, a curable compound, a polymerization initiator, an ultraviolet absorber, a solvent, and other additives, if necessary, by a conventional method, for example. .. The mixing order and the like are not particularly limited.

<Optical laminate>
The optical laminate of the present invention has the base film and a hard coat layer on at least one surface of the base film. Although FIG. 1 shows an embodiment of the present invention, the present invention is not limited to this aspect. The optical laminate 1 shown in FIG. 1 has a base film 2 and a hard coat layer 3 on one side of the base film 2.

Since the optical laminate of the present invention contains a polyamide resin and an aromatic compound in the base film, it has excellent surface hardness, and is also excellent in transparency and ultraviolet absorption. By having an excellent surface hardness, it is possible to effectively suppress scratches on the surface of the image display device when it is used as a front plate (window film) of the image display device. Therefore, the optical laminate of the present invention is useful as a front plate of an image display device, particularly a front plate (window film) of a flexible display. The optical laminate can be arranged as a front plate on the visible side surface of an image display device, particularly a flexible display. This front plate has a function of protecting the image display element in the flexible display. The image display device provided with the optical laminate has excellent surface hardness, as well as excellent transparency and ultraviolet absorption. Examples of the image display device include wearable devices such as televisions, smartphones, mobile phones, car navigation systems, tablet PCs, portable game machines, electronic papers, indicators, bulletin boards, watches, and smart watches. Examples of the flexible display include image display devices having flexible characteristics, such as televisions, smartphones, mobile phones, car navigation systems, tablet PCs, portable game machines, electronic papers, indicators, bulletin boards, clocks, and wearable devices.

The pencil hardness of the optical laminate is preferably 2B or more, more preferably B or more, still more preferably HB or more, particularly preferably H or more, extremely preferably 2H or more, and particularly preferably 3H or more. When the pencil hardness of the optical laminate is at least the lower limit value, scratches on the surface of the image display device can be effectively suppressed when used as the front plate of the image display device. The surface hardness of the optical laminate is usually 9H or less. The pencil hardness can be measured by, for example, the method described in Examples.

The YI value (yellowness) of the optical laminate is preferably 10 or less, more preferably 8 or less, still more preferably 5 or less, and particularly preferably 3 or less. An optical laminate having a YI value (yellowness) of not more than the above upper limit value has good transparency and can contribute to high visibility when used as a front plate of an image display device. Further, the YI value (yellowness) of the optical laminate is preferably 0 or more. The YI value (yellowness) can be measured by, for example, the method described in Examples.

The light transmittance of the optical laminate at 390 nm is preferably 35% or less, more preferably 30% or less, still more preferably 25% or less, and particularly preferably 20% or less. When the light transmittance of the optical laminate is not more than the above upper limit value, the ultraviolet absorption is good, and when used for the front plate of an image display device, it may contribute to the prevention of deterioration of the liquid crystal or the polarizing film. it can. The light transmittance at 390 nm can be measured by, for example, the method described in Examples.

The method for producing the optical laminate is not particularly limited, but for example, the following steps:
(A) A step (coating step A) of applying a liquid containing a polyamide resin and an aromatic compound (sometimes referred to as a polyamide resin varnish) to a resin base material to form a coating film, and (b) coating. A step of drying a liquid (coating film) to form a base film (base film forming step)
(C) A step of applying the curable composition to at least one surface of the base film to form a coating film (coating step B).
(D) A step of irradiating the applied liquid (coating film) with high-energy rays to cure the coating film to form a hard coat layer (hard coat layer forming step).
It can be manufactured by a manufacturing method including.

In the coating step A, first, a liquid (polyamide-based resin varnish) containing a polyamide-based resin and an aromatic compound is prepared. For the preparation of the polyamide resin varnish, the diamine compound, the tetracarboxylic acid compound, the dicarboxylic acid compound, and, if necessary, other components such as a tertiary amine acting as an imidization catalyst and a dehydrating agent are added. Mix and react to prepare a polyamide-based resin mixture. Examples of the tertiary amine include the above-mentioned aromatic amine and aliphatic amine. Examples of the dehydrating agent include acetic anhydride, propionic anhydride, isobutyric anhydride, pivalic anhydride, butyric anhydride, isovaleric anhydride and the like. A poor solvent is added to this polyamide-based resin mixed solution to precipitate the polyamide-based resin by a reprecipitation method, and the mixture is dried to remove the precipitate. If necessary, the precipitate is washed with a solvent such as methanol and dried to obtain a polyamide resin. Next, the polyamide resin is dissolved in a solvent, the above aromatic compound and other additives are added, and the mixture is stirred to prepare a liquid (polyamide resin varnish) containing the polyamide resin.

The solvent used for preparing the polyamide-based resin varnish is not particularly limited as long as the polyamide-based resin can be dissolved. Examples of such a solvent include amide solvents such as N, N-dimethylacetamide and N, N-dimethylformamide; lactone solvents such as γ-butyrolactone and γ-valerolactone; sulfur-containing solvents such as dimethyl sulfoxide, dimethyl sulfoxide and sulfolane. Solvents; carbonate solvents such as ethylene carbonate and propylene carbonate; and combinations thereof (mixed solvents) can be mentioned. Among these solvents, an amide solvent or a lactone solvent is preferable. Further, the polyamide-based resin varnish may contain water, an alcohol-based solvent, a ketone-based solvent, an acyclic ester-based solvent, an ether-based solvent, and the like.

Next, a polyamide-based resin varnish is applied onto a substrate such as a resin substrate, a SUS belt, or a glass substrate by a known coating method to form a coating film. Known coating methods include, for example, wire bar coating method, reverse coating, roll coating method such as gravure coating, die coating method, comma coating method, lip coating method, spin coating method, screen coating method, fountain coating method, dipping method, and the like. Examples include a spray method and a salivation molding method.

In the base film forming step, the base film can be formed by drying the coating film and peeling it from the resin base material. After peeling, a drying step of further drying the base film may be performed. The coating film can usually be dried at a temperature of 50 to 350 ° C. If necessary, the coating film may be dried under conditions of an inert atmosphere or reduced pressure.

Examples of the resin base material include PET film, PEN film, polyimide film, polyamide-imide film and the like. Among them, PET film, PEN film, polyimide film, and other polyamide-imide film are preferable from the viewpoint of excellent heat resistance. Further, a PET film is more preferable from the viewpoint of adhesion to the optical laminate and cost.

In the coating step B, the curable composition dissolved in the solvent may be coated on the base film. Examples of the solvent include the same solvents as those described in the section <Hard coat layer>, and examples of the coating method include the above-mentioned known coating methods.

The coating film formed on the base film may be dried. The coating film can be dried by evaporating the solvent at a temperature of 50 to 150 ° C., and the drying time is usually 30 to 180 seconds. If necessary, the coating film may be dried under conditions of an inert atmosphere or reduced pressure.

In the hard coat layer forming step, the coating film is irradiated with high energy rays (for example, active energy rays) to cure the coating film to form a hard coat layer. The irradiation intensity is appropriately determined by the composition of the curable composition, and is not particularly limited, but irradiation in a wavelength region effective for activating the polymerization initiator is preferable. The irradiation intensity is preferably 0.1~6,000mW / cm ^2, more preferably 10~1,000mW / cm ^2, more preferably from 20 to 500 mW / cm ^2. When the irradiation intensity is within the above range, an appropriate reaction time can be secured, and yellowing and deterioration of the resin due to heat radiated from the light source and heat generated during the curing reaction can be suppressed. The irradiation time may be appropriately selected depending on the composition of the curable composition and is not particularly limited, but the integrated light amount expressed as the product of the irradiation intensity and the irradiation time is preferably 10 to 10,000 mJ /. It is set to be cm ² , more preferably 50 to 1,000 mJ / cm ² , and even more preferably 80 to 500 mJ / cm ² . When the integrated light amount is within the above range, a sufficient amount of active species derived from the polymerization initiator can be generated to allow the curing reaction to proceed more reliably, and the irradiation time does not become too long, resulting in good productivity. Can be maintained. Further, it is useful because the hardness of the hard coat layer can be further increased by undergoing the irradiation step in this range.

The optical laminate of the present invention may have a layer different from the base film and the hard coat layer. Examples of the other layer include a functional layer, and examples of the functional layer include layers having various functions such as an ultraviolet absorbing layer, an adhesive layer, a hue adjusting layer, and a refractive index adjusting layer. The optical laminate may include one or more functional layers. Moreover, one functional layer may have a plurality of functions.

The ultraviolet absorbing layer is a layer having an ultraviolet absorbing function. For example, a main material selected from an ultraviolet curable transparent resin, an electron beam curable transparent resin, and a heat curable transparent resin, and the main material thereof. It is composed of a dispersed ultraviolet absorber (for example, the above-mentioned ultraviolet absorber). By providing the ultraviolet absorbing layer as the functional layer, the change in yellowness due to light irradiation can be easily suppressed.

The adhesive layer is a layer having an adhesive function, and has a function of adhering an optical laminate to another member. As a material for forming the adhesive layer, a commonly known material can be used. For example, a thermosetting resin composition or a photocurable resin composition can be used.

The adhesive layer may be composed of a resin composition containing a component having a polymerizable functional group. In this case, strong adhesion can be realized by further polymerizing the resin composition constituting the adhesive layer after the optical laminate is brought into close contact with another member. The adhesive strength between the optical laminate and the adhesive layer may be preferably 0.1 N / cm or more, more preferably 0.5 N / cm or more.

The adhesive layer may contain a thermosetting resin composition or a photocurable resin composition as a material. In this case, the resin composition can be polymerized and cured by supplying energy after the fact.

The adhesive layer may be a layer composed of an adhesive called a pressure-sensitive adhesive (Pressure Sensitive Adhesive, PSA), which is adhered to an object by pressing. The pressure-sensitive adhesive may be an adhesive that is "a substance that has adhesiveness at room temperature and adheres to an adherend with a light pressure" (JIS K 6800), and "protects a specific component (microcapsules). ), It may be a capsule type adhesive which is an adhesive which can maintain stability until the film is destroyed by an appropriate means (pressure, heat, etc.) ”(JIS K 6800).

The hue adjusting layer is a layer having a hue adjusting function, and is a layer capable of adjusting the optical laminate to a desired hue. The hue adjusting layer is, for example, a layer containing a resin and a colorant. Examples of this colorant include inorganic pigments such as titanium oxide, zinc oxide, petals, titanium oxide-based calcined pigments, ultramarine, cobalt aluminate, and carbon black; azo compounds, quinacridone compounds, anthracinone compounds, and the like. Organic pigments such as perylene compounds, isoindolinone compounds, phthalocyanine compounds, quinophthalone compounds, slene compounds, and diketopyrrolopyrrole compounds; extender pigments such as barium sulfate and calcium carbonate; and basic dyes, Examples thereof include dyes such as acidic dyes and medium dyes.

The refractive index adjusting layer is a layer having a function of adjusting the refractive index, has a refractive index different from that of the optical laminated body, and can impart a predetermined refractive index to the optical laminated body. The refractive index adjusting layer may be, for example, a resin layer appropriately selected and, if necessary, a resin layer further containing a pigment, or a thin film of metal.

Examples of the pigment for adjusting the refractive index include silicon oxide, aluminum oxide, antimony oxide, tin oxide, titanium oxide, zirconium oxide and tantalum oxide. The average primary particle size of the pigment may be 0.1 μm or less. By setting the average primary particle diameter of the pigment to 0.1 μm or less, it is possible to prevent diffused reflection of light passing through the refractive index adjusting layer and prevent deterioration of transparency.

Examples of the metal used for the refractive index adjusting layer include metals such as titanium oxide, tantalum oxide, zirconium oxide, zinc oxide, tin oxide, silicon oxide, indium oxide, titanium oxynitride, titanium nitride, silicon oxynitride, and silicon nitride. Oxides or metal nitrides can be mentioned.

[Flexible image display device]
The present invention includes a flexible image display device including the optical laminate of the present invention. The optical laminate of the present invention is preferably used as a front plate in a flexible image display device, and the front plate may be referred to as a window film. The flexible image display device includes a laminate for a flexible image display device and an organic EL display panel, and the laminate for the flexible image display device is arranged on the visual side with respect to the organic EL display panel and is configured to be bendable. ing. The laminated body for the flexible image display device may further contain a polarizing plate, preferably a circular polarizing plate, and a touch sensor, and the stacking order thereof is arbitrary, but the window film, the polarizing plate, and the touch sensor are viewed from the visual side. Alternatively, it is preferable that the window film, the touch sensor, and the polarizing plate are laminated in this order. If a polarizing plate is present on the visual side of the touch sensor, the pattern of the touch sensor is less likely to be visually recognized and the visibility of the displayed image is improved, which is preferable. Each member can be laminated using an adhesive, an adhesive, or the like. Further, a light-shielding pattern formed on at least one surface of any layer of the window film, the polarizing plate, and the touch sensor can be provided.

[Circular polarizing plate]
As described above, the flexible image display device of the present invention preferably includes a polarizing plate, particularly a circular polarizing plate. The circular polarizing plate is a functional layer having a function of transmitting only the right or left circular polarization component by laminating a λ / 4 retardation plate on a linear polarizing plate. For example, the external light is converted to right circular polarization and reflected by the organic EL panel to block the left circular polarization, and only the light emitting component of the organic EL is transmitted to suppress the influence of the reflected light. It is used to make it easier to see. In order to achieve the circular polarization function, the absorption axis of the linear polarizing plate and the slow axis of the λ / 4 retardation plate need to be theoretically 45 °, but practically 45 ± 10 °. The linear polarizing plate and the λ / 4 retardation plate do not necessarily have to be laminated adjacent to each other, and the relationship between the absorption axis and the slow phase axis may satisfy the above range. The circular polarizing plate in the present invention also includes an elliptical polarizing plate because it is preferable to achieve perfect circular polarization at all wavelengths, but it is not always necessary in practical use. It is also preferable to further laminate a λ / 4 retardation film on the visible side of the linear polarizing plate to convert the emitted light into circularly polarized light to improve the visibility in the state of wearing polarized sunglasses.

The linear polarizing plate is a functional layer having a function of passing light vibrating in the transmission axis direction but blocking polarization of a vibration component perpendicular to the linear polarizing plate. The linear polarizing plate may be configured to include a linear polarizing element alone or a linear polarizing element and a protective film attached to at least one surface thereof. The thickness of the linear polarizing plate may be 200 μm or less, preferably 0.5 to 100 μm. When the thickness of the linear polarizing plate is within the above range, the flexibility of the linear polarizing plate tends to be difficult to decrease.
The linear polarizer may be a film-type polarizer produced by dyeing and stretching a polyvinyl alcohol (hereinafter, may be abbreviated as PVA) -based film. A dichroic dye such as iodine is adsorbed on the PVA-based film oriented by stretching, or the dichroic dye is oriented in a state of being adsorbed on the PVA to exhibit polarization performance. In the production of the film-type polarizer, other steps such as swelling, cross-linking with boric acid, washing with an aqueous solution, and drying may be included. The stretching and dyeing steps may be performed on the PVA-based film alone, or may be performed in a state of being laminated with another film such as polyethylene terephthalate. The film thickness of the PVA-based film used is preferably 10 to 100 μm, and the draw ratio is preferably 2 to 10 times.
Further, 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 contain a liquid crystal compound and a dichroic dye compound. The liquid crystal compound may have a property of exhibiting a liquid crystal state, and is particularly preferable when it has a higher-order orientation state such as a smectic phase because it can exhibit high polarization performance. Further, the liquid crystal compound preferably has a polymerizable functional group.
The dichroic dye compound is a dye that is oriented together with the liquid crystal compound to exhibit dichroism, and may have a polymerizable functional group, and the dichroic dye itself has a liquid crystal property. You may be.
Any of the compounds contained in the liquid crystal polarizing composition has a polymerizable functional group. The liquid crystal polarizing composition can further contain an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a cross-linking 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 thickness of the liquid crystal polarizing layer can be formed to be thinner than that of the film-type polarizing element, 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 orientation by rubbing, polarized light irradiation, or the like. The alignment film forming composition contains an alignment agent, and may further contain a solvent, a cross-linking agent, an initiator, a dispersant, a leveling agent, a silane coupling agent, and the like. Examples of the alignment agent include polyvinyl alcohols, polyacrylates, polyamic acids, and polyimides. When an orientation agent that imparts orientation by polarization irradiation is used, it is preferable to use an orientation agent containing a synnamate 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 film thickness of the alignment film is preferably 5 to 10,000 nm, and more preferably 10 to 500 nm in that the alignment regulating force is sufficiently exhibited.
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 serves as a transparent base material for a protective film, a retardation plate, and a window film.
As the protective film, any transparent polymer film may be used, and the same materials and additives used for the transparent base material of the window film can be used. Further, it may be a coating type protective film obtained by applying and curing a cationic curing composition such as an epoxy resin or a radical curing composition such as acrylate. The protective film may be a plasticizer, an ultraviolet absorber, an infrared absorber, a colorant such as a pigment or a dye, a fluorescent whitening agent, a dispersant, a heat stabilizer, a light stabilizer, an antioxidant, an antioxidant, if necessary. , Lubricants, solvents and the like may be contained. 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 within the above range, the flexibility of the film tends to be difficult to decrease.

The λ / 4 retardation plate is a film that gives a retardation of λ / 4 in a direction orthogonal to the traveling direction of incident light (in-plane direction of the film). The λ / 4 retardation plate may be a stretch-type retardation plate manufactured by stretching a polymer film such as a cellulose-based film, an olefin-based film, or a polycarbonate-based film. The λ / 4 retardation plate may be used as a retardation adjuster, a plastic agent, an ultraviolet absorber, an infrared absorber, a colorant such as a pigment or a dye, a fluorescent whitening agent, a dispersant, a heat stabilizer, and a light stabilizer. It may contain an agent, an antioxidant, an antioxidant, a lubricant, a solvent and the like.
The thickness of the stretched retardation plate is preferably 200 μm or less, more preferably 1 to 100 μm. When the thickness of the stretchable retardation plate is within the above range, the flexibility of the stretchable retardation plate tends to be difficult to decrease.
Further, as another example of the λ / 4 retardation plate, there is a liquid crystal coating type retardation plate formed by coating a liquid crystal composition.
The liquid crystal composition contains a liquid crystal compound exhibiting a liquid crystal state such as nematic, cholesteric, and smectic. The liquid crystal compound has a polymerizable functional group.
The liquid crystal composition can further contain an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a cross-linking agent, a silane coupling agent, and the like.

The liquid crystal coating type retardation plate can be manufactured by applying a liquid crystal composition on a substrate and curing the liquid crystal composition to form a liquid crystal retardation layer, similarly to the liquid crystal polarizing layer. The liquid crystal coating type retardation plate can be formed to be thinner than the stretch type 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 base material, transferred and laminated, or the base material can be laminated as it is. It is also preferable that the base material serves as a transparent base material for a protective film, a retardation plate, and a window film.
In general, there are many materials that exhibit larger birefringence at shorter wavelengths and smaller birefringence at longer wavelengths. In this case, since it is not possible to achieve a phase difference of λ / 4 in the entire visible light region, the in-plane phase difference is preferably 100 to 4 so that it becomes λ / 4 with respect to the vicinity of 560 nm, which has high luminosity factor. It is designed to be 180 nm, more preferably 130-150 nm. A reverse dispersion λ / 4 retardation plate using a material having a birefringence wavelength dispersion characteristic opposite to the usual one is preferable in that visibility is good. As such a material, for example, a stretchable retardation plate can be used as described in JP-A-2007-232873, and a liquid crystal-coated retardation plate can be used as described in JP-A-2010-30979. ..
Further, as another method, a technique for obtaining a wideband λ / 4 retardation plate by combining with a λ / 2 retardation plate is also known (for example, Japanese Patent Application Laid-Open No. 10-90521). The λ / 2 retardation plate is also manufactured by the same material method as the λ / 4 retardation plate. The combination of the stretchable retardation plate and the liquid crystal coating type retardation plate is arbitrary, but the film thickness can be reduced by using the liquid crystal coating type retardation plate in both cases.
A method of laminating a positive C plate on the circular polarizing plate in order to improve visibility in an oblique direction is known (for example, Japanese Patent Application Laid-Open No. 2014-224837). The positive C plate may be a liquid crystal coating type retardation plate or a stretched retardation plate. The phase difference 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 image display device of the present invention preferably includes a touch sensor. The touch sensor is used as an 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, and a capacitance method, and a capacitance method is preferable.
The capacitive touch sensor is divided into an active region and an inactive region located outside the active region. The active area is an area corresponding to the area where the screen is displayed on the display panel (display unit), the area where the user's touch is sensed, and the inactive area is the area where the screen is not displayed on the display device (non-active area). This is the area corresponding to the display unit). The touch sensor is formed in a substrate having flexible characteristics, a sensing pattern formed in an active region of the substrate, and an inactive region of the substrate, and is connected to an external drive circuit via the sensing pattern and a pad portion. Each sensing line for 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 can include a first pattern formed in the first direction and a second pattern formed in the second direction. The first pattern and the second pattern are arranged in different directions from each other. The first pattern and the second pattern are formed in the same layer, and each pattern must be electrically connected in order to sense the touched point. The first pattern is a form in which a plurality of unit patterns are connected to each other via 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, so that the second pattern is electrically operated. A separate bridge electrode is required for the connection. A well-known transparent electrode can be applied to the electrode for connecting the second pattern. Examples of the material of the transparent electrode include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc oxide oxide (IZTO), and cadmium tin oxide (CTO). PEDOT (poly (3,4-ethylenedioxythiophene)), carbon nanotubes (CNT), graphene, metal wire and the like can be mentioned, and ITO is preferably mentioned. These can be used alone or in combination 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, chromium, etc., and these may be used alone or in combination of two or more. Can be done.

The bridge electrode can be formed on the upper part of the insulating layer via the insulating layer on the upper part of the sensing pattern, the bridge electrode is formed on the substrate, and the insulating layer and the sensing pattern can be formed on the bridge electrode. The bridge electrode can be made of the same material as the sensing pattern, or it can be made of molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium or two or more alloys of these. 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 may be formed only between the joint of the first pattern and the bridge electrode, or may be formed as a layer covering the entire sensing pattern. In the case of a layer that covers the entire sensing pattern, the bridge electrode can connect 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 region in which a sensing pattern is formed and a non-pattern region in which a sensing pattern is not formed, specifically, a difference in refractive index in these regions. An optical adjustment 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 control layer may contain an inorganic insulating material or an organic insulating material. The optical control 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 contain inorganic particles. The refractive index of the optical control layer can be increased by the inorganic particles.
The photocurable organic binder contains a copolymer of each monomer such as an acrylate-based monomer, a styrene-based monomer, and a carboxylic acid-based monomer, as long as the effects of the present invention are not impaired. be able to. The photocurable organic binder may be, for example, a copolymer containing 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, alumina particles and the like.
The photocuring composition may further contain additives such as a photopolymerization initiator, a polymerizable monomer, and a curing aid.

[Adhesive layer]
Each layer (window film, circular polarizing plate, touch sensor) forming the laminated body for the flexible image display device and the film member (straight polarizing plate, λ / 4 retardation plate, etc.) constituting each layer are joined by an adhesive. Can be done. Examples of the adhesive include water-based adhesives, organic solvent-based adhesives, solvent-free adhesives, solid adhesives, solvent volatilization adhesives, moisture-curing adhesives, heat-curing adhesives, anaerobic curing types, and active energy ray-curing adhesives. Commonly used adhesives such as mold adhesives, hardener mixed adhesives, heat-melt adhesives, pressure-sensitive adhesives (adhesives), and re-wet adhesives can be used, preferably aqueous solvent volatilization. Mold adhesives, active energy ray-curable adhesives, and adhesives can be used. The thickness of the adhesive layer can be appropriately adjusted according to the required adhesive force and the like, and is preferably 0.01 to 500 μm, more preferably 0.1 to 300 μm. The laminated body for a flexible image display device has a plurality of adhesive layers, and the thickness of each adhesive layer and the type of the adhesive layer may be the same or different.

As the aqueous solvent volatilization type adhesive, a polyvinyl alcohol-based polymer, a water-soluble polymer such as starch, an ethylene-vinyl acetate-based emulsion, a styrene-butadiene-based emulsion, or the like in an aqueous-dispersed state can be used as the main component polymer. In addition to the main polymer and water, a cross-linking agent, a silane compound, an ionic compound, a cross-linking catalyst, an antioxidant, a dye, a pigment, an inorganic filler, an organic solvent and the like may be blended. When adhering with the water-based solvent volatilization type adhesive, the water-based solvent volatilization type adhesive can be injected between the layers to be adhered, the adherend layers are bonded, and then dried to impart adhesiveness. When the water-based solvent volatilization type adhesive is used, the thickness of the adhesive layer is preferably 0.01 to 10 μm, more preferably 0.1 to 1 μm. When the water-based solvent volatilization type adhesive is used in a plurality of layers, the thickness of each layer and the type of the water-based solvent volatilization type adhesive used 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 is irradiated with active energy rays to form an adhesive layer. The active energy ray-curable composition can contain at least one polymer of a radically polymerizable compound and a cationically polymerizable compound similar to those contained in the hard coat composition. As the radically polymerizable compound, the same compound as the radically polymerizable compound in the hard coat composition can be used.
As the cationically polymerizable compound, the same compound as the cationically polymerizable compound in the hard coat composition can be used.
As the cationically polymerizable compound used in the active energy ray-curing composition, an epoxy compound is particularly preferable. It is also preferable to include a monofunctional compound as a reactive diluent in order to reduce the viscosity of the adhesive composition.
The active energy ray composition can contain a monofunctional compound in order to reduce the viscosity. Examples of the monofunctional compound include an acrylate-based monomer having one (meth) acryloyl group in one molecule, and a compound having one epoxy group or oxetanyl group in one molecule, for example, glycidyl (meth). ) Acrylate and the like can be mentioned.
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 promote radical polymerization and cation polymerization. In the description of the hard coat composition, an initiator that can initiate 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 comprises an ion scavenger, an antioxidant, a chain transfer agent, an adhesion imparting agent, a thermoplastic resin, a filler, a fluid viscosity modifier, a plasticizer, a defoaming agent solvent, an additive, and a solvent. Can be included. When two layers to be adhered are bonded by the active energy ray-curable adhesive, the active energy ray-curable composition is applied to either or both of the layers to be adhered, and then bonded to each layer. Alternatively, both layers to be adhered can be adhered by irradiating them with active energy rays and curing them. When the active energy ray-curable adhesive is used, the thickness of the adhesive layer is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm. When the active energy ray-curable adhesive is used for forming a plurality of adhesive layers, the thickness of each layer and the type of the active energy ray-curable adhesive used may be the same or different.
As the pressure-sensitive adhesive, the same pressure-sensitive adhesive as described above can be used. When a plurality of layers of the pressure-sensitive adhesive are used, the thickness of each layer and the type of pressure-sensitive adhesive used may be the same or different.

[Shading pattern]
The shading pattern can be applied as at least part of the bezel or housing of the flexible image display device. The light-shielding pattern hides the wiring arranged at the edge of the flexible image display device to make it difficult to see, thereby improving the visibility of the image. The shading pattern may be in the form of a single layer or multiple layers. The color of the light-shielding pattern is not particularly limited, and may be various colors such as black, white, and metallic. The light-shielding pattern can be formed of a pigment for embodying color and a polymer such as an acrylic resin, an ester resin, an epoxy resin, polyurethane, or silicone. They can also be used alone or in admixture of two or more. The shading pattern can be formed by various methods such as printing, lithography, and inkjet. The thickness of the shading 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.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

1. 1. Measurement method and evaluation (1) Yellowness (YI value)
Performed using a spectrophotometer (U-4100) manufactured by Hitachi, Ltd., using the tristimulus values X, Y and Z calculated by the calculation method specified in JIS Z 8701: 1982, and the following formula. The yellowness (YI value) of the optical laminates obtained in Examples and Comparative Examples was calculated. The evaluation method is shown below.
YI = 100 (1.28X-1.06Z) / Y
<Evaluation method>
Those with YI ≦ 3 were regarded as very good and marked with ⊚.
Those with 3 <YI ≦ 10 were regarded as good and marked with 〇.
Those with 10 <YI were regarded as defective and marked with x.

(2) Light transmittance (Tt)
Using a spectrophotometer (U-4100) manufactured by Hitachi, Ltd., the hard-coated surface side of the optical laminates obtained in Examples and Comparative Examples was irradiated, and the transmittance for light at 390 nm was measured.
The measurement results are shown in Table 1.

(3) Pencil hardness The pencil hardness of the surface of the optical laminate on the hard coat surface side was measured using a uni manufactured by Mitsubishi Pencil Co., Ltd. in accordance with JIS K 5600-5-4: 1999. The optical laminate used for the measurement was fixed on a glass plate having a thickness of 2 mm, and the measurement was performed under the conditions of a load of 750 g at an angle of 90 ° and a scanning speed of 60 mm / min. The presence or absence of scratches was evaluated under an illuminance condition of 4,000 lux of light, and the pencil hardness was determined. The measurement results are shown in Table 1.

(4) Measurement of Weight Average Molecular Weight (Mw) The weight average molecular weight (Mw) of polyamide-imide was determined by gel permeation chromatography (GPC) measurement in terms of standard polystyrene. The specific measurement conditions were as follows.
a. Pretreatment method DMF eluent (10 mM lithium bromide solution) is added to polyamide-imide (sample) to a concentration of 2 mg / mL, heated at 80 ° C. with stirring for 30 minutes, cooled, and then 0.45 μm membrane. The solution obtained by filtering with a filter was used as a measurement solution.
b. Measurement conditions Column: TSKgel SuperAWM-H x 2 + SuperAW2500 x 1 (6.0 mm ID x 150 mm x 3)
Eluent: DMF (10 mM lithium bromide added)
Flow rate: 1.0 mL / min.
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μL
Molecular weight standard: Standard polystyrene

(5) Thickness measurement The thickness of the base film was measured using a Micrometer (Micrometer Mitutoyo), and the thickness of the hard coat layer was measured by the F20 tabletop film thickness system manufactured by Filmetics.

2. UV absorbers The following UV absorbers were prepared.
Sumisorb 340 (trade name: manufactured by Sumitomo Chemical Co., Ltd., 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole)

3. 3. Polyamide-based resin (1) Polyamide-imide A (6FDA / TPC / BPDA = 3/6/1 (molar ratio))
53.05 g (165.66 mmol) of 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB) and N, N in a 1 L separable flask equipped with a stirring blade under a nitrogen gas atmosphere. -Dimethylacetamide (hereinafter sometimes referred to as DMAc) 670.91 g was added, and TFMB was dissolved in DMAc with stirring at room temperature. Next, in a flask, 22.11 g (49.77 mmol) of 4,4'-(hexafluoroisopropyridene) diphthalic acid dianhydride (6FDA), 3,3', 4,4'-biphenyltetracarboxylic dianhydride is used. 4.88 g (16.59 mmol) of the substance (BPDA) was added, then 20.21 g (99.54 mmol) of terephthaloyl chloride (TPC) was added, and the mixture was stirred at room temperature for 1 hour. Next, 10.53 g (133.08 mmol) of pyridine and 13.77 g (134.83 mmol) of acetic anhydride were added to the flask, and after stirring at room temperature for 30 minutes, the temperature was raised to 70 ° C. using an oil bath for another 3 hours. The mixture was stirred to obtain a reaction solution.
The obtained reaction solution was cooled to room temperature, poured into a large amount of methanol in the form of filaments, the precipitated precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C. to obtain polyamide-imide A. The weight average molecular weight of polyamide-imide A was 190,000.

(2) Polyamide-imide B (6FDA / TPC / OBBC = 3/6/1 (molar ratio))
Under a nitrogen gas atmosphere, 45 g (140.52 mmol) of TFMB and 859.96 g of DMAc were added to a 1 L separable flask equipped with a stirring blade, and TFMB was dissolved in DMAc while stirring at room temperature. Next, 18.87 g (42.48 mmol) of 6FDA was added to the flask, followed by 17.14 g (84.42 mmol) of TPC, 4.60 g (14.08 mmol) of 4,4'-oxybis (benzoyl chloride) (OBBC). Was added, and the mixture was stirred at room temperature for 1 hour. Next, 4.62 g (49.55 mmol) of 4-picoline and 2.96 g (28.96 mmol) of acetic anhydride were added to the flask, and the mixture was stirred at room temperature for 30 minutes, heated to 70 ° C. using an oil bath, and further. The mixture was stirred for 3 hours to obtain a reaction solution.
The obtained reaction solution was cooled to room temperature, poured into a large amount of methanol in the form of filaments, the precipitated precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C. to obtain a polyamide-imide B. The weight average molecular weight of polyamide-imide B was 430,000.

4. A γ-butyrolactone (hereinafter, also referred to as GBL) substituted silica sol obtained by solvent substitution using an amorphous silica sol having a BET diameter of 27 nm produced by an inorganic particle sol-gel method was used. In each of the obtained GBL-substituted silica sol, the silica component (inorganic particles) was 30% by mass.

5. Curable composition (composition for hard coat)
The following curable composition (composition for hard coating) was prepared.
Z-850-AFH (acrylic hard coat) manufactured by Aica Kogyo Co., Ltd.

[Example 1]
Polyamideimide A was diluted with DMAc to prepare a polyamide-imide varnish having a concentration of 22% by mass. A DMAc solution of an ultraviolet absorber [2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, "Sumisorb 340", manufactured by Sumika Chemical Co., Ltd.] was mixed therewith, and then the mixture was stirred for 30 minutes. The content of the ultraviolet absorber was 5.5 parts by mass with respect to 100 parts by mass of polyamide-imide A. The obtained polyamide-imide varnish containing an ultraviolet absorber is applied onto a smooth surface of a polyester base material (manufactured by Toyobo Co., Ltd., trade name "A4100") using an applicator so that the thickness of the free-standing film is 55 μm. After drying at 50 ° C. for 30 minutes and then at 140 ° C. for 15 minutes, the obtained coating film was peeled off from the polyester substrate to obtain a self-supporting film. The free-standing film was fixed to a gold frame and further dried in the air at 300 ° C. for 40 minutes to obtain a polyamide-imide film (base film) having a thickness of 50 μm.
The composition for hard coating is applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then cured by irradiating with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) under a nitrogen atmosphere. To form a coating film, an optical laminate was obtained. The film thickness of the hard coat layer was 10 μm. The light transmittance of the optical laminate at 390 nm was 11.9%.

[Example 2]
Polyamideimide B was diluted in a solution prepared by dissolving an ultraviolet absorber [Sumisorb 340, manufactured by Sumika Chemical Co., Ltd.] in a GBL solution to prepare a polyamide-imide varnish having a concentration of 9.5% by mass. The content of the ultraviolet absorber was 5.5 parts by mass with respect to 100 parts by mass of polyamide-imide B. The obtained polyamide-imide varnish containing an ultraviolet absorber is applied onto a smooth surface of a polyester base material (manufactured by Toyobo Co., Ltd., trade name "A4100") using an applicator so that the thickness of the free-standing film is 55 μm. After drying at 50 ° C. for 30 minutes and then at 140 ° C. for 15 minutes, the obtained coating film was peeled off from the polyester substrate to obtain a self-supporting film. The self-supporting film was fixed to a gold frame and further dried in the air at 200 ° C. for 40 minutes to obtain a polyamide-imide film (base film) having a thickness of 50 μm.
The composition for hard coating is applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then cured by irradiating with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) under a nitrogen atmosphere. To form a coating film, an optical laminate was obtained. The film thickness of the hard coat layer was 10 μm. The light transmittance of the optical laminate at 390 nm was 18.5%.

[Example 3]
An optical laminate was obtained in the same manner as in Example 2 except that the GBL-substituted silica sol was added to the polyamide-imide varnish. The film thickness of the base film and the film thickness of the hard coat layer were 50 μm and 10 μm, respectively. The transmittance of the optical laminate with respect to light at 390 nm was 17.5%. The content of the silica sol was 50 parts by mass with respect to 100 parts by mass of polyamide-imide B.

[Example 4]
Polyamideimide B was diluted in a solution prepared by dissolving an ultraviolet absorber [hydroxyphenyltriazine derivative, "Tinuvin 400", manufactured by BASF Co., Ltd.] in a GBL solution to prepare a polyamide-imide varnish having a concentration of 9.5% by mass. The content of the ultraviolet absorber was 2.0 parts by mass with respect to 100 parts by mass of polyamide-imide B. The obtained polyamide-imide varnish containing an ultraviolet absorber is applied onto a smooth surface of a polyester base material (manufactured by Toyobo Co., Ltd., trade name "A4100") using an applicator so that the thickness of the free-standing film is 55 μm. After drying at 50 ° C. for 30 minutes and then at 140 ° C. for 15 minutes, the obtained coating film was peeled off from the polyester substrate to obtain a self-supporting film. The self-supporting film was fixed to a gold frame and further dried in the air at 200 ° C. for 40 minutes to obtain a polyamide-imide film (base film) having a thickness of 50 μm.
The composition for hard coating is applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then cured by irradiating with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) under a nitrogen atmosphere. To form a coating film, an optical laminate was obtained. The film thickness of the hard coat layer was 10 μm. The light transmittance of the optical laminate at 390 nm was 65.1%.

[Example 5]
Polyamideimide B was diluted in a solution prepared by dissolving an ultraviolet absorber [Sumisorb 340, manufactured by Sumika Chemical Co., Ltd.] in a GBL solution to prepare a polyamide-imide varnish having a concentration of 9.5% by mass. The content of the ultraviolet absorber was 2.0 parts by mass with respect to 100 parts by mass of polyamide-imide B. The obtained polyamide-imide varnish containing an ultraviolet absorber was applied onto a smooth surface of a polyester base material (manufactured by Toyobo, trade name "A4100") using an applicator so that the thickness of the free-standing film was 55 μm, and the temperature was 50 ° C. After drying at 140 ° C. for 15 minutes, the obtained coating film was peeled off from the polyester substrate to obtain a self-supporting film. The self-supporting film was fixed to a gold frame and further dried in the air at 200 ° C. for 40 minutes to obtain a polyamide-imide film (base film) having a thickness of 50 μm.
The composition for hard coating is applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then cured by irradiating with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) under a nitrogen atmosphere. To form a coating film, an optical laminate was obtained. The film thickness of the hard coat layer was 10 μm. The light transmittance of the optical laminate at 390 nm was 45.3%.

[Example 6]
Polyamide-imide B to which GBL-substituted silica sol was added was diluted in a solution in which an ultraviolet absorber [hydroxyphenyltriazine derivative, "Tinuvin 479", manufactured by BASF Co., Ltd.] was dissolved in a GBL solution, and the concentration was 9.5% by mass. An imide varnish was prepared. The content of the ultraviolet absorber was 1.0 part by mass with respect to 100 parts by mass of polyamide-imide B. The obtained polyamide-imide varnish containing an ultraviolet absorber is applied onto a smooth surface of a polyester base material (manufactured by Toyobo Co., Ltd., trade name "A4100") using an applicator so that the thickness of the free-standing film is 55 μm. After drying at 50 ° C. for 30 minutes and then at 140 ° C. for 15 minutes, the obtained coating film was peeled off from the polyester substrate to obtain a self-supporting film. The self-supporting film was fixed to a gold frame and further dried in the air at 200 ° C. for 40 minutes to obtain a polyamide-imide film (base film) having a thickness of 50 μm. The content of the silica sol was 50 parts by mass with respect to 100 parts by mass of polyamide-imide B.
The composition for hard coating is applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then cured by irradiating with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) under a nitrogen atmosphere. To form a coating film, an optical laminate was obtained. The film thickness of the hard coat layer was 10 μm. The light transmittance of the optical laminate at 390 nm was 58.1%.

[Comparative Example 1]
Polyamideimide A was diluted with DMAc to prepare a polyamide-imide varnish having a concentration of 22% by mass. The obtained polyimide varnish was applied onto a smooth surface of a polyester base material (manufactured by Toyobo Co., Ltd., trade name "A4100") using an applicator so that the thickness of the free-standing film was 55 μm, and the film was applied at 50 ° C. for 30 minutes. Then, after drying at 140 ° C. for 15 minutes, the obtained coating film was peeled off from the polyester substrate to obtain a self-supporting film. The free-standing film was fixed to a gold frame and further dried in the air at 300 ° C. for 40 minutes to obtain a polyamide-imide film (base film) having a thickness of 50 μm.
A hard coat composition containing an ultraviolet absorber, which is obtained by adding Sumisorb 340 [manufactured by Sumika Chemical Co., Ltd.] to the hard coat composition used in Example 1, is applied to the obtained base film by a bar coater. Then, after drying at 80 ° C. for 3 minutes, a coating film was formed by irradiating with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) in a nitrogen atmosphere and curing to obtain an optical laminate. The film thickness of the hard coat layer was 10 μm. The amount of the ultraviolet absorber was 5 parts by mass with respect to 100 parts by mass of the component excluding the solvent of the composition for hard coating.

Table 1 shows the results of measuring the YI value and the pencil hardness of the optical laminates obtained in Examples 1 to 6 (Examples 4 to 6 are reference examples) and Comparative Example 1.

It was confirmed that the optical laminates of Examples 1 to 6 had a significantly higher pencil hardness than the optical laminate of Comparative Example 1. Further, the optical laminates of Examples 2 to 6 have a lower YI value than the optical laminate of Comparative Example 1 (evaluation is very good), and the optical laminate of Example 1 has a good evaluation of the YI value. Was confirmed. Therefore, the optical laminates of Examples 1 to 6 can have excellent surface hardness and excellent transparency. It was also found that the optical laminates of Examples 1 to 3 had low light transmittance at 390 nm and were excellent in ultraviolet absorption.

1 ... Optical laminate 2 ... Base film 3 ... Hard coat layer

Claims (8)

Polyamideimide, and a substrate film comprising an aromatic compound is a UV absorber, an optical laminate having a hard coat layer on at least one surface of the substrate film, the polyamide-imide has the formula (1 ) And formula (2):

[In formulas (1) and (2), X and Z each independently represent a divalent organic group, and Y represents a tetravalent organic group].
The content of the structural unit represented by the formula (2) is 0.1 to 3.9 mol with respect to 1 mol of the structural unit represented by the formula (1). An optical laminate in which the content of the ultraviolet absorber is 3 to 10 parts by mass with respect to 100 parts by mass of polyamide-imide, and the yellowness of the optical laminate is 5 or less. The optical laminate according to claim 1 , wherein the content of the ultraviolet absorber contained in the base film is larger than the content of the ultraviolet absorber in the hard coat layer. The optical laminate according to claim 1 or 2 , wherein the base film contains inorganic particles. The optical laminate according to any one of claims 1 to 3 , wherein the light transmittance at 390 nm is 35% or less. Polyamideimides have the formulas (1) and (2):

[In formulas (1) and (2), X and Z each independently represent a divalent organic group, and Y represents a tetravalent organic group.
At least a part of Z is the equation (3):

(In the formula (3), R ^{1 to} R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and hydrogen contained in R ^{1 to} R ⁸ is contained. Atoms may be independently substituted with halogen atoms,
A represents -O-, -S-, -CO- or -N (R ⁹ )-, and R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom.
m is an integer from 0 to 4
* Represents a bond)
In represented Ru]
The optical laminate according to any one of claims 1 to 4 , which has a structural unit represented by. A flexible image display device comprising the optical laminate according to any one of claims 1 to 5 . The flexible image display device according to claim 6 , further comprising a polarizing plate. The flexible image display device according to claim 6 or 7 , further comprising a touch sensor.

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