JP2019202551A - Optical laminate - Google Patents

Abstract

To provide an optical laminate having excellent surface hardness.SOLUTION: An optical laminate contains a substrate film containing a polyamide resin and an aromatic compound, and a hard coat layer on at least one side of the substrate film.SELECTED DRAWING: Figure 1

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 a front plate of such an image display device. Glass is highly transparent and can exhibit high hardness depending on the type of glass, but it is very rigid and easily broken, making it difficult to use as a front plate material for flexible displays. Therefore, the use of a polymer material as a material to replace glass is being studied. Since the front plate made of a polymer material is easy to exhibit flexible characteristics, it can be expected to be used for various applications. There are various types of flexible resins, one of which is polyamideimide. Polyamideimide is used in various applications from the viewpoints of transparency and heat resistance (for example, JP-A-2016-125063).

JP 2016-126503 A

  The front plate of such an image display device requires a high surface hardness because the user directly touches or surrounding objects directly touch. However, according to the study of the present inventor, it has been found that the optical layered body containing a polyamide-based resin may not have sufficient surface hardness.

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

  As a result of intensive studies to solve the above-mentioned problems, the present inventor, as an optical laminate having a hard coat layer on at least one surface of a base film containing a polyamide-based resin, contains an aromatic compound in the base film. Then, it discovered that the said objective was achieved and came to complete this invention. That is, the present invention includes the following.

[1] An optical laminate having a base film containing a polyamide-based 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 polyamideimide.
[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] Polyamideimide is represented by the formulas (1) and (2):
[In Formula (1) and Formula (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 formula (2) is 0.1 to 3.9 moles per mole of the structural unit represented by 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 includes 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] Polyamideimide is represented by formula (1) and formula (2):
[In Formula (1) and Formula (2), X and Z each independently represent a divalent organic group, Y represents a tetravalent organic group,
At least part of Z is represented by formula (3):
(In Formula (3), R < ¹ > -R < ⁸ > represents a hydrogen atom, a C1-C6 alkyl group, or a C6-C12 aryl group each independently, and hydrogen contained in R < ¹ > -R < ⁸ >. Each atom may be independently substituted with a halogen atom,
A represents —O—, —S—, —CO— or —N (R ⁹ ) —, wherein 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.)
Is a structural unit represented by
The optical laminated body in any one of [2]-[8] which has a structural unit represented by these.
[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 layered body of the present invention has a base film containing a polyamide-based resin and an aromatic compound, and a hard coat layer on at least one surface of the base film.

<Base film>
The base film includes a polyamide-based resin and an aromatic compound.

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

  The polyamide-based resin may be a polyamide, and is preferably a polyamideimide 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 polyamideimide has a structural unit represented by the formula (1) and a structural unit represented by the formula (2). It is preferable that

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

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

[In Formula (3), R ^{1 to} R ⁸ 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, and hydrogen contained in R ^{1 to} R ^8. Each atom may be independently substituted with a halogen atom,
A represents —O—, —S—, —CO—, or —N (R ⁹ ) —, and R ⁹ represents 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 these.

In the formula (3), each A independently represents —O—, —S—, —CO— or —N (R ⁹ ) —, and is preferably —O— from the viewpoint of flexibility of the optical laminate. Or -S- is represented, More preferably, -O- is represented.

R ^{1 to} R ⁸ each independently represents 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 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, 2-methyl- Examples thereof include a butyl group, a 3-methylbutyl group, a 2-ethyl-propyl group, and an n-hexyl group. Moreover, as a C6-C12 aryl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group etc. are mentioned, for example. From the viewpoint of the surface hardness and flexibility of the optical layered body, R ^{1 to} R ⁸ each independently preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or 1 to carbon atoms. Represents an alkyl group of 3, more preferably a hydrogen atom. Here, the hydrogen atoms contained in R ^{1 to} R ⁸ may be each independently substituted with a halogen atom.

R ⁹ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, 2-methyl-butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group, n-decyl group, etc. These may be substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  In 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. In 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, further preferably 0 or 1, and when m is within this range, The flexibility of the optical layered body is good, and at the same time, the availability of raw materials is relatively good. Z may contain one or more structural units represented by the formula (3), improve the surface hardness, elastic modulus and flex resistance of the optical laminate, and yellowness (YI value). ) From the viewpoint of reduction, it may contain two or more types of structural units having different values of m, preferably two types of structural units having different values of m. In that case, it is preferable that m includes both 0 and 1 structural units from the viewpoint of easily exhibiting high surface hardness, elastic modulus, flex resistance, and low yellowness (YI value).

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

Which can be used in combination. In this case, the optical laminate including the polyamide-based resin exhibits high surface hardness, and at the same time has 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 with respect to the total of Y and Z of the polyamide-based resin is preferably 20 mol% or more, and more Preferably it is 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, more preferably 85 mol% or less, More preferably, it is 80 mol% or less. An optical laminate comprising a polyamide resin when the structural unit represented by the formula (3) when m is 0 to 4 is equal to or more than the lower limit with respect to the total of Y and Z in the polyamide resin. The body can exhibit high surface hardness, low elasticity, and excellent flexibility. When the structural unit represented by the formula (3) when m is 0 to 4 is less than or equal to the above upper limit with respect to the total of Y and Z in the polyamide-based resin, between the amide bonds derived from the formula (3) By suppressing the thickening due to hydrogen bonding, 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 is preferably 3 mol% or more, based on the total of Y and Z of the polyamide-based resin. Preferably it is 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 30 mol% or less. An optical laminate comprising a polyamide-based resin when the structural unit represented by the formula (3) when m is 1 to 4 is greater than or equal to the lower limit with respect to the total of Y and Z in the polyamide-based resin. The body can exhibit high surface hardness, low elasticity, and excellent flexibility. When the surface hardness is high, the optical laminate, particularly the substrate, is hardly damaged, and as a result, the yield of the product is improved and it can contribute to energy saving. When the structural unit represented by Formula (3) when m is 1 to 4 is less than or equal to the above upper limit with respect to the total of Y and Z in the polyamide-based resin, between the amide bonds derived from Formula (3) By suppressing the thickening due to hydrogen bonding, 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, Z in the polyamide-based resin is preferably at least 30 mol%, more preferably at least 50 mol%, even more preferably at least 70 mol%, when m is 0-4. It is represented by Formula (3). When the above lower limit value of Z of the polyamide-based resin is expressed by the formula (3) when m is 1 to 4, the optical laminate including the polyamide-based resin exhibits high surface hardness and elasticity. The rate is low and it can have high flexibility. Moreover, it is preferable that 100 mol% or less of Z in a polyamide-type resin is represented by Formula (3) in case m is 0-4. When the above upper limit value of Z of the polyamide-based resin is represented by the formula (3) when m is 0 to 4, by suppressing the thickening due to the hydrogen bond between amide bonds derived from the formula (3), 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 structural units represented by in the polyamide resin equation (3) can also be calculated from, for example, ^{1 H-NMR} can be measured using, or the material feed ratio.

In a preferred embodiment of the present invention, Z in the polyamide-based resin is preferably 5 mol% or more, more preferably 8 mol% or more, further preferably 10 mol% or more, and particularly preferably 12 mol% or more. It is represented by Formula (3) when m is 1 to 4. When the above lower limit value of Z of the polyamide-based resin is expressed by the formula (3) when m is 1 to 4, the optical laminate including the polyamide-based resin exhibits high surface hardness and elasticity. The rate is low and it can have high flexibility. Further, Z in the polyamide-based 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, when m is 1 to 4. It is preferable that it is represented by Formula (3). When the above upper limit value of Z of the polyamide resin is represented by the formula (3) when m is 1 to 4, by suppressing the thickening due to hydrogen bonds between amide bonds derived from the formula (3), 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 structural units represented by in the polyamide resin equation (3) can also be calculated from, for example, ^{1 H-NMR} can be measured using, or the material feed ratio.

  In the formulas (1) and (2), each X independently represents a divalent organic group, preferably a hydrogen atom in the organic group is substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. It is also a good organic group. The polyamide-based resin that is 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. X is represented by Formula (10), Formula (11), Formula (12), Formula (13), Formula (14), Formula (15), Formula (16), Formula (17), and Formula (18). Groups in which hydrogen atoms in the groups represented by the formulas (10) to (18) are substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and a chain having 6 or less carbon atoms Illustrative are hydrocarbon radicals.

In formula (10) to formula (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 ) _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 exemplified for R ⁹ .
In one example, V ¹ and V ³ are a single bond, —O— or S—, and V ² is —CH ₂ —, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —. or -SO ₂ - it is. The bonding position of each of V ¹ and V ² with respect to each ring and the bonding position of each of V ² and V ³ with respect to each ring are preferably independently meta or para, more preferably para, with respect to each ring. Rank.

Among groups represented by the above formulas (10) to (18), from the viewpoint of surface hardness and flexibility of an optical laminate including a polyamide-based resin, the groups are represented by formulas (13) to (17). Group represented by Formula (14)-Formula (16) is more preferable. V ¹ , V ² and V ³ are each independently preferably a single bond, —O— or —S— from the viewpoint of surface hardness and flexibility of the optical laminate comprising the polyamide-based resin. More preferably a single bond or —O—.

  In a preferred embodiment of the present invention, at least some of the plurality of X in the formulas (1) and (2) are represented by the formula (4):

Wherein ^{(4), R} 10 ~R ¹⁷ independently represent a hydrogen atom, an alkyl group or an aryl group having 6 to 12 carbon atoms having 1 to 6 carbon ^atoms, hydrogen contained in R 10 ^{to R 17} Each atom may be independently substituted with a halogen atom, and * represents a bond]
Is a structural unit represented by When at least a part of a plurality of X in the formulas (1) and (2) is a group represented by the formula (4), the optical laminate including the polyamide-based resin can exhibit high surface hardness. At the same time, high transparency can be expressed.

In Formula (4), R ^{10 to} R ¹⁷ 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). R ^{10 to} R ¹⁷ each independently preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, where R ¹⁰ to R ¹⁰ Each hydrogen atom contained in R ¹⁷ may be independently substituted with a halogen atom. R ^{10 to} R ¹⁷ are each independently more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group, or a viewpoint of surface hardness, transparency and flexibility of an optical laminate comprising the polyamide-based resin. 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 formula (4) is represented by formula (4 '):

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

In a preferred embodiment of the present invention, X in the polyamide-based resin is preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70 mol% or more of the formula (4), particularly preferably the formula (4 '). When X within the above-mentioned range in the polyamide-based resin is represented by the formula (4), particularly the formula (4 ′), the optical laminate including the polyamide-based resin exhibits high transparency, and at the same time, an elemental fluorine. Due to the skeleton containing the polyamide-based resin, the solubility of the polyamide-based resin in the solvent can be improved, the viscosity of the polyamide-based resin varnish can be suppressed low, and the processing of the optical laminate can be facilitated. In addition, Preferably, 100 mol% or less of X in the said polyamide-type resin is represented by Formula (4), especially Formula (4 '). X in the polyamide-based resin may be the formula (4), particularly the formula (4 ′). The ratio of the structural unit represented by the formula (4) of X in the polyamide-based resin can be measured using, for example, ¹ H-NMR, or can be calculated from the raw material charge ratio.

  In formula (1), each Y independently represents a tetravalent organic group, and preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group It is. The polyamide-based resin that is 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, Formula (20), Formula (21), Formula (22), Formula (23), Formula (24), Formula (25), Formula (26), Formula (27), Formula (28), and Formula Groups represented by (29); groups in which hydrogen atoms in the groups represented by formulas (20) to (29) are substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and 4 Examples thereof include a chain hydrocarbon group having 6 or less valent carbon atoms.

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

Among the groups represented by the formula (20) to the formula (29), from the viewpoint of the surface hardness and flexibility of the optical laminate including the polyamide-based resin, the formula (26), the formula (28), and the formula (29) ) Is preferred, and the group represented by formula (26) is more preferred. 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 a single bond, —O—, —CH ₂ —, —CH (CH ₃ ). _{-, - C (CH 3)} 2 - or -C _{(CF 3) 2} -, more preferably a single bond, -C _{(CH 3) 2} - or -C _{(CF 3) 2} - it is a Further preferred.

  In a preferred embodiment of the present invention, at least some of the plurality of Y in formula (1) are represented by formula (5):

Wherein ^{(5), R} 18 ~R ²⁵ independently represent a hydrogen atom, an alkyl group or an aryl group having 6 to 12 carbon atoms having 1 to 6 carbon ^atoms, hydrogen contained in R 18 ^{to R 25} Each atom may be independently substituted with a halogen atom,
* Represents a bond]
Is a structural unit represented by When at least a part of the plurality of Y in the formula (1) is a group represented by the formula (5), the optical laminate including the polyamide-based resin exhibits high transparency and at the same time has high flexibility. Derived from the skeleton, the solubility of the polyamide resin in the solvent can be improved, the viscosity of the polyamide resin varnish can be suppressed low, and the processing of the optical laminate can be facilitated.

In 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). R ¹⁸ to R ²⁵ are each independently preferably represents an alkyl group having 1 to 6 carbon hydrogen atom or atoms, more preferably represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, ^{wherein, R 18} ~ Each hydrogen atom contained in R ²⁵ may be independently substituted with a halogen atom. R ^{18 to} R ²⁵ are each independently more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group or trifluoromethyl from the viewpoint of the surface hardness and flexibility of the optical laminate comprising the polyamide-based resin. 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 represented by the formula (5 ′):

That is, at least a part of the plurality of Y is a structural unit represented by the formula (5 ′). In this case, the optical laminate including the polyamide-based resin can have high transparency.

In a preferred embodiment of the present invention, Y in the polyamide-based resin is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more of formula (5), particularly formula (5). ') When Y within the above range in the polyamide-based resin is represented by the formula (5), in particular, the formula (5 ′), the optical laminate including the polyamide-based resin can have high transparency, and The solubility of the polyamide resin in the solvent can be improved by the skeleton containing elemental fluorine, the viscosity of the polyamide resin varnish can be suppressed low, and the production of the optical laminate is easy. In addition, Preferably, 100 mol% or less of Y in the said polyamide-type resin is represented by Formula (5), especially Formula (5 '). Y in the polyamide-based resin may be the formula (5), particularly the formula (5 ′). The ratio of the structural unit represented by Formula (5) of Y in the polyamide-based resin can be measured using, for example, ¹ H-NMR, or can be calculated from the raw material charge ratio.

  In the polyamide-based 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. , 000 or more, preferably 800,000 or less, more preferably 600,000 or less, and further preferably 500,000 or less. When the weight average molecular weight of the polyamide-based resin is not less than the above lower limit value, the optical laminate including the polyamide-based resin has a better bending resistance. Further, when the weight average molecular weight of the polyamide-based resin is not more than the above upper limit value, the viscosity of the polyamide-based resin varnish can be suppressed to a low level, and the optical laminate, particularly the base film, can be easily stretched. Property is improved. In the present specification, the weight average molecular weight can be obtained by, for example, GPC measurement and standard polystyrene conversion, and can be specifically obtained by the method described in Examples.

  In the polyamideimide, the content of the structural unit represented by the formula (2) is preferably 0.1 mol or more, more preferably 0.5 mol, relative to 1 mol of the structural unit represented by the formula (1). Mol or more, more preferably 1.0 mol or more, particularly preferably 1.5 mol or more, preferably 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 not less than the lower limit, the optical laminate including the polyamide-based resin can exhibit higher surface hardness. Moreover, when content of the structural unit represented by Formula (2) is below the said upper limit, the viscosity increase by the hydrogen bond between the amide bonds in Formula (2) is suppressed, and the viscosity of a polyamide-type resin varnish is made. The optical laminate can be easily manufactured.

  The polyamide-based resin includes a structural unit represented by the formula (30) and / or a structural unit represented by the formula (31) in addition to the structural units represented by the formulas (1) and (2). be able to.

In formula (30), Y ¹ is each independently a tetravalent organic group, and preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group It is a group. The Y ^1, equation (20), equation (21), equation (22), equation (23), equation (24), equation (25), equation (26), equation (27), equation (28) and Examples include a group represented by the formula (29) and a tetravalent chain hydrocarbon group having 6 or less carbon atoms. 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 Formula (31), Y ² is a trivalent organic group, preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. Y ² includes 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 formula (29) is replaced with a hydrogen atom, and a trivalent chain hydrocarbon group having 6 or less carbon atoms. 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 the formula (30) and the formula (31), X ¹ and X ² are each independently a divalent organic group, preferably a hydrocarbon group or a hydrocarbon group in which a hydrogen atom in the organic group is substituted with a fluorine group or fluorine. An organic group which may be substituted with X ¹ and X ² are groups represented by formula (10) to formula (18); a hydrogen atom in the groups represented by formula (10) to formula (18) is a methyl group, a fluoro group, chloro And a group substituted with a group or a trifluoromethyl group; and a chain hydrocarbon group having 6 or less carbon atoms.

In one embodiment of the present invention, the polyamideimide is composed of a structural unit represented by the formula (1) and the formula (2), and optionally a structural unit represented by the formula (30) and / or the formula (31). Become. Moreover, from the viewpoint of the surface hardness and flexibility of the optical laminate comprising the polyamideimide, in the polyamideimide, the structural units represented by the formulas (1) and (2) are represented by the formulas (1) and (1). (2) and optionally based on all structural units represented by formula (30) and formula (31), preferably at least 80 mol%, more preferably at least 90 mol%, even more preferably at least 95 mol%. is there. In the polyamideimide, the structural units represented by the formula (1) and the formula (2) are represented by the formula (1) and the formula (2), and in some cases, the formula (30) and the formula (31). Based on all structural units, it is usually 100% or less. The above ratio is, for example, can also be calculated from ^{1 H-NMR} can be measured using, or the material feed ratio.

  In the polyamide-based resin, the polyamide can be produced using, for example, a dicarboxylic acid compound and a diamine compound, which will be described later, as main raw materials, and the polyamideimide, for example, mainly includes a tetracarboxylic acid compound, a dicarboxylic acid compound, and a diamine compound, which will be described later. Can be produced as a raw material. Here, the dicarboxylic acid compound preferably contains at least a compound represented by the formula (3 ″).

[In Formula (3 ″), R ^{1 to} R ⁸ 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, 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 represents 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 each independently —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 , And represents —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 formula (3 ″), wherein A is —O—. In another preferred embodiment, the dicarboxylic acid compound is R ³¹ and R ³² are each a compound represented by the formula (3 ″) in which —Cl. Further, a diisocyanate compound may be used in place of the diamine compound.

  Examples of tetracarboxylic acid compounds used for the synthesis of polyamide-based resins include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic dianhydrides; and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydrides. Is mentioned. A tetracarboxylic acid compound may be used independently and may use 2 or more types together. The tetracarboxylic acid compound may be a dianhydride or a tetracarboxylic acid compound analog such as an acid chloride compound.

Specific examples of the aromatic tetracarboxylic dianhydride include non-condensed polycyclic aromatic tetracarboxylic dianhydride, monocyclic aromatic tetracarboxylic dianhydride, and condensed polycyclic aromatic tetra Carboxylic dianhydrides are mentioned. Non-condensed polycyclic aromatic tetracarboxylic dianhydrides include, for example, 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-di Carboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (describe 6FDA) There is) 1,2-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis (3,4-dicarboxy) Phenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) ) Methane dianhydride, 4,4 ′-(p-phenylenedioxy) diphthalic dianhydride, 4,4 ′-(m-phenylenedioxy) diphthalic dianhydride. In addition, examples of the monocyclic aromatic tetracarboxylic dianhydride include 1,2,4,5-benzenetetracarboxylic dianhydride, and condensed polycyclic aromatic tetracarboxylic dianhydride. Examples thereof include 2,3,6,7-naphthalenetetracarboxylic dianhydride.
Among these, preferably 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride Anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyl Sulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2- Bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), 1,2-bis (2,3-dicarboxyphenyl) Etani Water, 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-phenylenedi Oxy) diphthalic dianhydride and 4,4 ′-(m-phenylenedioxy) diphthalic dianhydride, more preferably 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4, 4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), bis (3,4-Dicarboki Ciphenyl) 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 a cyclic or acyclic aliphatic tetracarboxylic dianhydride. The cycloaliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having an alicyclic hydrocarbon structure, and specific examples thereof include 1,2,4,5-cyclohexanetetracarboxylic dianhydride. 1, 2,3,4-cyclobutanetetracarboxylic dianhydride, cycloalkanetetracarboxylic dianhydride such as 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2.2 .2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl 3,3′-4,4′-tetracarboxylic dianhydride and their positional isomers. . These can be used alone or in combination of two or more. Specific examples of the acyclic aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and 1,2,3,4-pentanetetracarboxylic dianhydride. These may be used alone or in combination of two or more. Moreover, you may use combining a cycloaliphatic tetracarboxylic dianhydride and an acyclic aliphatic tetracarboxylic dianhydride.

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

Examples of the dicarboxylic acid compound used for the synthesis of the polyamide-based resin include aromatic dicarboxylic acids, aliphatic dicarboxylic acids and related acid chloride compounds, acid anhydrides, and the like, and two or more kinds may be used in combination. Specific examples include terephthalic acid; isophthalic acid; naphthalenedicarboxylic acid; 4,4′-biphenyldicarboxylic acid; 3,3′-biphenyldicarboxylic acid; chain hydrocarbons having 8 or less carbon atoms; A compound in which two benzoic acids are linked by a single bond, —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′-oxybisbenzoic acid, terephthalic acid, and acid chlorides thereof are preferable, 4,4′-oxybis (benzoyl chloride) and terephthaloyl chloride are preferable, and 4,4 ′. -The combined use of oxybis (benzoyl chloride) and terephthaloyl chloride is more preferred.

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

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

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

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

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

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

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

  Among the above diamine compounds, one kind selected from the group consisting of aromatic diamines having a biphenyl structure from the viewpoint of the 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 a diamine compound, a tetracarboxylic acid compound (an acid chloride compound, a tetracarboxylic acid analog such as tetracarboxylic dianhydride), and a dicarboxylic acid compound (an acid chloride compound). Dicarboxylic acid compound analogs), and in some cases, a condensation polymer that is a polycondensation product of a tricarboxylic acid compound (an acid chloride compound, a tricarboxylic acid compound analog such as a tricarboxylic acid anhydride). The structural unit represented by Formula (1) and Formula (30) is normally derived from a diamine and a tetracarboxylic acid compound. 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 a halogen atom as described above. Specific examples of the fluorine-containing substituent include a fluoro group and a trifluoromethyl group. When the polyamide-based resin contains a halogen atom, the yellowness (YI value) of the optical laminate including the polyamide-based resin may be reduced, and both higher flexibility and bending resistance may be achieved. There is a tendency to be able to. In addition, from the viewpoints of reducing the yellowness of the optical layered body, that is, improving transparency, reducing water absorption, and bending resistance, the halogen atom is preferably a fluorine atom.

  The content of halogen atoms in the polyamide-based resin is preferably 1 on the basis of the mass of the polyamide-based resin from the viewpoint of reducing yellowness, that is, improving transparency, reducing water absorption, and suppressing deformation of the optical laminate. It is -40 mass%, More preferably, it is 3-35 mass%, More preferably, it is 5-32 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 the imidation catalyst include aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; N-ethylpiperidine, N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydro Alicyclic amines (monocyclic) such as azepine; azabicyclo [2.2.1] heptane, azabicyclo [3.2.1] octane, azabicyclo [2.2.2] octane, and azabicyclo [3.2. 2] Alicyclic amines (polycyclic) such as nonane; and pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2, 4-dimethylpyridine, 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5 6,7,8-tetrahydroisoquinoline, and aromatic amines isoquinoline.

  Although reaction temperature of a diamine compound, a tetracarboxylic acid compound, and a dicarboxylic acid compound is not specifically limited, For example, it is 50-350 degreeC. Although reaction time is not specifically limited, For example, it is about 30 minutes-10 hours. If necessary, the reaction may be carried out under an inert atmosphere or under reduced pressure. The reaction may be carried out in a solvent, and examples of the solvent include a solvent described later used for preparing a polyamide resin varnish.

(Aromatic compounds)
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 may be a monocyclic hydrocarbon ring such as a benzene ring. A condensed bicyclic hydrocarbon ring such as naphthalene, and a polycyclic hydrocarbon ring such as a ring assembly hydrocarbon ring such as biphenyl. Moreover, as a substituent, for example, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, or a C 1 -C 1 similar to those exemplified as the alkyl group having 1 to 6 carbons in the formula (3). 6 alkyl group, phenyl group, nitro group, cyano group, hydroxyl group, phenyloxy group and the like. One or more of these substituents may be substituted on the aromatic hydrocarbon ring.

  In the present invention, since the base film contains a polyamide-based resin and an aromatic compound, an optical laminate excellent in the surface hardness of the hard coat layer can be obtained. This is because the hardness of the base film increases due to the aromatic compound entering the space in the crosslinked structure formed by the hydrogen bond between the amide bonds of the polyamide resin contained in the base film, and the hard coat layer is affected by the influence. It is estimated that this is because the surface hardness of the material 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 UV absorbers include benzotriazole derivatives (benzotriazole UV absorbers), triazine derivatives such as 1,3,5-triphenyltriazine derivatives (triazine UV absorbers), and benzophenone derivatives (benzophenone UV absorbers). ) And salicylate derivatives (salicylate-based ultraviolet absorbers), and at least one selected from the group consisting of these can be used. While improving the surface hardness of the optical layered body and having a good ultraviolet absorbing ability at 370 to 400 nm and being able to protect the polarizing plate when laminated with the polarizing plate, benzotriazole type ultraviolet absorber and triazine type ultraviolet ray It is preferable to use at least one selected from the group consisting of absorbers, and benzotriazole ultraviolet absorbers are more preferable.

  Specific examples of the benzotriazole ultraviolet absorber include a compound represented by the formula (I), a trade name: Sumisorb (registered trademark) 250 (2- [2-hydroxy-3- (3) manufactured by Sumitomo Chemical Co., Ltd. , 4,5,6-tetrahydrophthalimide-methodiyl) -5-methylphenyl] benzotriazole), trade name: Tinuvin (registered trademark) 360 (2,2′-methylenebis [6- (2H) manufactured by BASF Japan Ltd. -Benzotriazol-2-yl) -4-tert-octylphenol]) and Tinuvin 213 (methyl 3- [3- (2H-benzotriazol-2-yl) 5-tert-butyl-4-hydroxyphenyl] propionate and PEG300 Reaction products) and these are used alone or in combination of two or more. Door can be. As specific examples of the compound represented by the formula (I), trade names: Sumisorb 200 (2- (2-hydroxy-5-methylphenyl) benzotriazole), Sumisorb 300 (2- (3) manufactured by Sumitomo Chemical Co., Ltd. -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), and trade name: Tinuvin 327 (2- (2′-hydroxy-3 ′, 5′-di-tert-butyl) manufactured by BASF Japan Ltd. Phenyl) -5-chlorobenzotriazole), Tinuvin 5 71 (2- (2H-benzotriazo-2-yl) -6-dodecyl-4-methyl-phenol) and Tinuvin 234 (2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl) -1-phenylethyl) phenol) and ADEKA Corporation product name: ADK STAB (registered trademark) LA-31 (2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1) , 1,3,3-tetramethylbutyl) phenol]). The UV absorber is preferably a compound represented by formula (I) and Tinuvin 213 (methyl 3- [3- (2H-benzotriazol-2-yl) 5-tert-butyl-4-hydroxyphenyl] propionate It is a reaction product with PEG300, More preferably, Sumitomo Chemical Co., Ltd. trade name: 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 Corporation: ADK STAB LA-31 (2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetra) Trade name: Tinuvin 327 (2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole) and Tinuvin manufactured by BASF Japan Ltd. 571 (2- (2H-benzotriazo-2-yl) -6-dodecyl-4-methyl-phenol), most preferably trade name: Sumisorb 340 (2- (2-hydroxy-) manufactured by Sumitomo Chemical Co., Ltd. 5-tert-octylphenyl) benzotriazole), Sumisorb 350 (2- (2-hydroxy-3,5- -Tert-pentylphenyl) benzotriazole) and product name of ADEKA Corporation: ADK STAB LA-31 (2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1,1) , 3,3-tetramethylbutyl) phenol]).

In 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 R ^I1 and R ^I2 are each independently a hydrogen atom. Alternatively, it is a hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ^{I1 and} 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 include 2-methyl-butoxy group, 3-methylbutoxy group, 2-ethyl-propoxy group and the like.
X ^I is preferably a hydrogen atom, a fluorine atom, a chlorine atom or a methyl group, more preferably a hydrogen atom, a fluorine atom or a chlorine atom.

R ^I1 and R ^I2 are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ^I1 and R ^I2 is a hydrocarbon group. When R ^I1 and R ^I2 are each a hydrocarbon group, it is preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrocarbon group having 1 to 8 carbon atoms. Specific examples 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 ultraviolet absorber is used in an optical laminate containing a polyamide resin. Examples of the triazine-based ultraviolet absorber include a compound represented by the following formula (II). Specific examples thereof include ADEKA Corporation product name: ADK STAB LA-46 (2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- [2- (2-ethyl) Hexanoyloxy) ethoxy] phenol), a trade name of Tinufin 400 (2- [4- [2-hydroxy-3-tridecyloxypropyl] oxy] -2-hydroxyphenyl] -4,6 manufactured by BASF Japan Ltd. -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- Droxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine), Tinuvin 460 (2,4-bis (2-hydroxy-4-butyroxyphenyl) -6 (2,4-bis-butyroxyphenyl) -1,3,5-triazine), Tinuvin 479 (hydroxyphenyltriazine ultraviolet absorber), and Chemipro Kasei Co., Ltd. product names: KEMISORB (registered trademark) 102 ( 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (n-octyloxy) phenol) and the like. A combination of more than one species can be used. The compound represented by the formula (II) is preferably ADK STAB LA-46 (2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- [2- (2-ethyl) Hexanoyloxy) ethoxy] phenol).

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

In the formula (II), R ^I3 is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms in which one oxygen atom is contained, or an alkylketoxy having 1 to 12 carbon atoms. A C1-C4 alkoxy group substituted with a group, preferably substituted with a C1-C12 alkoxy group containing one oxygen atom or a C8-C12 alkylketoxy group It is a C2-C4 alkoxy group, More preferably, it is a C2-C4 alkoxy group substituted by the C8-C12 alkyl ketoxy group.

Examples of the alkyl group 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, n -Pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-undecyl group can be mentioned.

  In one embodiment, it is preferable that the ultraviolet absorber is easily soluble in N, N-dimethylacetamide (hereinafter sometimes referred to as DMAc), which exhibits high solubility in polyamide-based resins. Such an ultraviolet absorber may be a compound that dissolves 1.0 g or more in 100 g of DMAc at 25 ° C., in other words, has a solubility in DMAc of 25 ° C. of 1.0 g / 100 g or more. The solubility of the ultraviolet absorber is preferably 5 g / 100 g or more, more preferably 10 g / 100 g or more, with respect to a solvent such as DMAc. There is no restriction | limiting in the upper limit of the solubility of a ultraviolet absorber, For example, 100g / 100g may be sufficient. Ultraviolet absorbers having high solubility in DMAc are easy to homogenize with polyamide resins, so that the surface hardness of the optical laminate can be improved, and it has high transparency and high ultraviolet absorption ability, and further can be colored. It can also be prevented.

  The ultraviolet absorber preferably has an ultraviolet absorptivity so that the light transmittance at 390 nm of the substrate film can be 35% or less, more preferably 25% or less, and still more preferably 20% or less.

  In the base film, the content of the ultraviolet absorber 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-based resin. It is. The surface hardness of an optical laminated body can be improved as content of a ultraviolet absorber is more than the said lower limit. Moreover, the yellowness of an optical laminated body can be suppressed (YI value can be reduced) as content of a ultraviolet absorber is below the said upper limit, and the transparency of an optical laminated body can be improved.

  In the base film, the content of the polyamide-based resin is preferably 30% by weight or more, more preferably 50% by weight or more, still more preferably 70% by weight or more, and particularly preferably 80% by weight with respect to the weight of the base film. % Or more, very preferably 90% by weight or more. When the content of the polyamide-based resin is not less than the above lower limit value, the surface hardness and flexibility of the optical laminate are good. In addition, content of the polyamide-type resin in a base film is usually less than 100 mass% on the basis of the total mass of a base film.

  The base film can further contain inorganic particles in addition to the polyamide resin and the aromatic compound from the viewpoint of easily improving the surface hardness of the optical laminate. Examples of the inorganic particles include titania particles, alumina particles, zirconia particles, and silica particles. In view of the stability of the polyamide-based resin varnish for producing the optical laminate and the improvement in the surface hardness of the optical laminate, the inorganic particles are particularly preferably silica particles. The inorganic particles may be bonded by molecules 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 aggregation suppression of the inorganic particles. In the present invention, the average primary particle diameter can be determined by measuring the 10-point average value of the constant direction diameter by 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, and still more preferably 20% with respect to the mass of the base film. It is at least 30% by mass, particularly preferably at least 30% by mass, preferably at most 70% by mass, more preferably at most 60% by mass. If the content of the inorganic particles is not less than the above lower limit value, it is advantageous for improving the surface hardness of the hard coat layer, and if it is not more than the above upper limit value, it is advantageous for reducing 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, and leveling agents.

  The content of other additives is preferably 0 to 20% by mass and more preferably 0 to 10% by mass with respect to the mass of the base film.

  Although the thickness of a base film is suitably adjusted according to a use, it is 10-200 micrometers normally, Preferably it is 20-100 micrometers, More preferably, it is 25-80 micrometers, More preferably, it is 30-50 micrometers. In addition, in this invention, the thickness of a base film can be measured by the method as described in an Example, for example.

<Hard coat layer>
The optical layered body of the present invention has a hard coat layer on at least one surface of the substrate 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, epoxy, urethane, benzyl chloride, and vinyl. 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 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, tri Methylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate , Pentaerythritol tetra (meth) acrylate, glycerin tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol Tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris ((meth) acryloyloxyethyl) isocyanurate; Introduced phosphazene-based (meth) acrylate compound; urethane obtained by reaction of polyisocyanate having at least two isocyanate groups in the molecule with polyol compound having at least one (meth) acryloyloxy group and hydroxyl group (meta ) Acrylate compound; poly obtained by reacting at least two carboxylic acid halides in the molecule with a polyol compound having at least one (meth) acryloyloxy group and hydroxyl group Ester (meth) acrylate compound; and dimer of each compound, and the like oligomers, such as trimers. These compounds may be used alone or in combination of two or more.

  The curable compound may contain a monofunctional (meth) acrylate compound in addition to the polyfunctional (meth) acrylate compound. Examples of monofunctional (meth) acrylate compounds include hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and 2-hydroxy-3. -Phenoxypropyl (meth) acrylate, glycidyl (meth) acrylate, etc. can be mentioned. These compounds are used alone or in combination of two or more. It is preferable that content of a monofunctional (meth) acrylate type compound is 10 mass% or less in solid content of the compound contained in a curable composition.

  Further, the curable compound may contain a polymerizable oligomer. By including the polymerizable oligomer, the hardness of the hard coat layer can be adjusted. As the polymerizable oligomer, 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, terminal Examples thereof include macromonomers such as (meth) acrylate styrene-methyl (meth) acrylate copolymer. It is preferable that content of a polymerizable oligomer is 5-50 mass% in solid content of the compound contained in a 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-morpholinopropan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenyl Screw (2, , 6-trimethylbenzoyl) -phosphine oxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, benzaldehyde, benzoin ethyl ether, benzoisopropyl ether, benzophenone, Michler's ketone, 3-methylacetophenone, 3,3 ', 4,4'-tetra-tert-butylperoxycarbonylbenzophenone (BTTB), 2- (dimethylamino) -1- [4- (morpholinyl) phenyl] -2-phenyl Methyl) -1-butanone, 4-benzoyl-4′-methyldiphenyl sulfide, benzyl, and derivatives thereof. These polymerization initiators may be used alone or in combination of several kinds as necessary. The polymerization initiators exemplified above are all photopolymerization initiators that generate radicals upon irradiation with active energy rays.

  The content of the polymerization initiator is preferably 0.1 to 10 parts by mass, 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 within the above range, the curability of the curable composition becomes good, and the surface hardness of the hard coat layer can be increased.

  A curable composition can contain the thing similar to the ultraviolet absorber as described in the term of <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 is 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, and still more preferably 0 with respect to 100 parts by mass of the curable composition. Part by mass. 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 resulting from containing the ultraviolet absorber. It 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. In addition, content of the ultraviolet absorber contained in a base film and content of the ultraviolet absorber in a hard-coat layer can be compared on the basis of the total mass of an optical laminated body, for example.

  The curable composition may contain a solvent in order to improve the coating property on the base film. Examples of the solvent include aliphatic hydrocarbons such as hexane and octane; aromatic hydrocarbons such as toluene and xylene; alcohols such as ethanol, 1-propanol, isopropanol and 1-butanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone. Esters such as ethyl acetate, butyl acetate and isobutyl acetate; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether and propylene glycol monoethyl ether; ethylene glycol monomethyl Select appropriately from esterified glycol ethers such as ether acetate and propylene glycol monomethyl ether acetate. It can be used. These solvents can be used alone or in combination of two or more. The kind and content of the solvent are appropriately selected according to the kind and content of the curable compound to be 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, bluing agents, flame retardants, pH adjusters, silica dispersions described in the section <Base film> Agents, lubricants, thickeners, leveling agents and the like. When a curable composition contains another additive, content of another additive becomes like this. Preferably it is 0.01-20 mass% with respect to the mass of a curable composition, More preferably, it is 0.1-10. % By 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 the bending resistance of the optical laminate and the pencil hardness. In addition, the thickness of a hard-coat layer can be measured by the method as described in an Example, for example.

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

<Optical laminate>
The optical layered body of the present invention has the base film and a hard coat layer on at least one surface of the base film. FIG. 1 shows one embodiment of the present invention, but the present invention is not limited to this embodiment. An 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-based resin and an aromatic compound in the base film, it has excellent surface hardness and excellent transparency and ultraviolet absorption. By having an excellent surface hardness, when used as a front plate (window film) of an image display device, it is possible to effectively suppress scratches on the surface 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 as a front plate (window film) of a flexible display. This optical laminated body can be arrange | positioned as a front plate on the visual recognition side surface of an image display apparatus, especially a flexible display. The front plate has a function of protecting the image display element in the flexible display. An image display device including the optical laminate has excellent surface hardness, and at the same time, excellent transparency and ultraviolet absorption. Examples of the image display device include wearable devices such as a television, a smartphone, a mobile phone, a car navigation, a tablet PC, a portable game machine, electronic paper, an indicator, a bulletin board, a clock, and a smart watch. Examples of the flexible display include an image display device having flexible characteristics, such as a television, a smartphone, a mobile phone, a car navigation system, a tablet PC, a portable game machine, electronic paper, an indicator, a bulletin board, a clock, and a wearable device.

  The pencil hardness of the optical laminate is preferably 2B or more, more preferably B or more, further preferably HB or more, particularly preferably H or more, very preferably 2H or more, and particularly preferably 3H or more. When the pencil hardness of the optical layered body is equal to or higher than the lower limit, it is possible to effectively suppress scratches on the surface of the image display device when used as a front plate of the image display device. Further, the surface hardness of the optical laminate is usually 9H or less. In addition, pencil hardness can be measured by the method as described in an Example, for example.

  The YI value (yellowness) of the optical layered body is preferably 10 or less, more preferably 8 or less, still more preferably 5 or less, and particularly preferably 3 or less. An optical layered body having a YI value (yellowness) equal to or lower than the above upper limit has good transparency, and can contribute to high visibility when used for a front plate of an image display device. The YI value (yellowness) of the optical layered body is preferably 0 or more. The YI value (yellowness) can be measured, for example, by the method described in the examples.

  The light transmittance at 390 nm of the optical laminate 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 the image display device, it can contribute to the prevention of deterioration of the liquid crystal and the polarizing film. it can. In addition, the light transmittance in 390 nm can be measured by the method as described in an Example, for example.

Although the manufacturing method of an optical laminated body is not specifically limited, For example, the following processes:
(A) A step of applying a liquid containing a polyamide-based resin and an aromatic compound (sometimes referred to as a polyamide-based resin varnish) to form a coating film (application step A), and (b) being applied Process of drying the liquid (coating film) to form a base film (base film forming process)
(C) The process of apply | coating the said curable composition to the at least one surface of this base film, and forming a coating film (application | coating process B)
(D) A process of irradiating the applied liquid (coating film) with high energy rays and curing the coating film to form a hard coat layer (hard coat layer forming process)
It can manufacture with the manufacturing method containing.

  In the coating step A, a liquid (polyamide resin varnish) containing a polyamide resin and an aromatic compound is first prepared. For the preparation of the polyamide-based resin varnish, the diamine compound, the tetracarboxylic acid compound, the dicarboxylic acid compound, and, if necessary, other components such as a tertiary amine and a dehydrating agent that act as an imidization catalyst. Mix and react to prepare a polyamide resin mixture. Examples of the tertiary amine include the aromatic amines and aliphatic amines described above. 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 the polyamide-based resin mixed solution to precipitate a polyamide-based resin by a reprecipitation method, and the precipitate is taken out by drying. If necessary, the precipitate is washed with a solvent such as methanol and dried to obtain a polyamide-based resin. Next, a polyamide-based resin is dissolved in a solvent, and the aromatic compound and other additives are added and stirred to prepare a liquid (polyamide-based resin varnish) containing the polyamide-based resin.

  The solvent used for the preparation of the polyamide resin varnish is not particularly limited as long as it can dissolve the polyamide resin. Examples of such solvents 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 dimethylsulfone, dimethylsulfoxide, and sulfolane. Examples thereof include carbonate solvents such as ethylene carbonate and propylene carbonate; and combinations (mixed solvents) thereof. Among these solvents, amide solvents or lactone solvents are preferable. The polyamide resin varnish may contain water, an alcohol solvent, a ketone solvent, an acyclic ester solvent, an ether solvent, and the like.

  Next, a polyamide 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, roll coating methods such as wire bar coating, reverse coating, and gravure coating, die coating, comma coating, lip coating, spin coating, screen coating, fountain coating, dipping, Examples thereof include a spray method and a fluent molding method.

  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. You may perform the drying process which dries a base film further after peeling. The coating film can be dried usually at a temperature of 50 to 350 ° C. If necessary, the coating film may be dried under an inert atmosphere or under reduced pressure.

  Examples of the resin substrate include a PET film, a PEN film, a polyimide film, and a polyamideimide film. Among these, from the viewpoint of excellent heat resistance, a PET film, a PEN film, a polyimide film, and other polyamideimide films are preferable. Furthermore, a PET film is more preferable from the viewpoint of adhesion to the optical laminate and cost.

  In the coating step B, a curable composition dissolved in a solvent may be applied to the base film. Examples of the solvent include the same solvents as those described in the section <Hard Coat Layer>, and examples of the application method include the above-described known application methods.

  You may dry the coating film formed on the base film. 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 an inert atmosphere or under reduced pressure.

In the hard coat layer forming step, the coating film is irradiated with high energy rays (for example, active energy rays), and the coating film is cured to form a hard coat layer. The irradiation intensity is appropriately determined depending on 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. However, the integrated light amount expressed as the product of the irradiation intensity and the irradiation time is preferably 10 to 10,000 mJ / 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 quantity 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 is not too long, and good productivity is achieved. Can be maintained. Moreover, it is useful because the hardness of the hard coat layer can be further increased by performing an irradiation step in this range.

  The optical layered body 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 layered body may include one or a plurality of functional layers. 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 thermosetting transparent resin, It is comprised from the disperse | distributed ultraviolet absorber (for example, the said ultraviolet absorber). By providing the ultraviolet absorbing layer as the functional layer, a change in yellowness due to light irradiation can be easily suppressed.

  The pressure-sensitive adhesive layer is a layer having a sticky function, and has a function of bonding the optical layered body to another member. As the material for forming the adhesive layer, a conventionally known material can be used. For example, a thermosetting resin composition or a photocurable resin composition can be used.

  The adhesion layer may be comprised from the resin composition containing the component which has 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 layered body is brought into close contact with another member. The adhesive strength between the optical laminate and the pressure-sensitive adhesive layer may be preferably 0.1 N / cm or more, more preferably 0.5 N / cm or more.

  The pressure-sensitive 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 afterwards.

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

  The hue adjustment layer is a layer having a hue adjustment function, and is a layer capable of adjusting the optical layered body to a target hue. A hue adjustment layer is a layer containing resin and a coloring agent, for example. Examples of the colorant include inorganic pigments such as titanium oxide, zinc oxide, dial, titanium oxide-based fired pigment, ultramarine blue, cobalt aluminate, and carbon black; azo compounds, quinacridone compounds, anthraquinone compounds, Organic pigments such as perylene compounds, isoindolinone compounds, phthalocyanine compounds, quinophthalone compounds, selenium compounds, and diketopyrrolopyrrole compounds; extender pigments such as barium sulfate and calcium carbonate; and basic dyes; Examples include acid dyes and mordant 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 give a predetermined refractive index to the optical laminated body. The refractive index adjustment layer may be, for example, an appropriately selected resin, and optionally a resin layer further containing a pigment, or may be a metal thin film.

  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 diameter 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, irregular reflection of light transmitted through the refractive index adjusting layer can be prevented, and a decrease in transparency can be prevented.

  Examples of the metal used for the refractive index adjustment 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 may be mentioned.

[Flexible image display device]
This invention includes a flexible image display apparatus provided with the optical laminated body of this invention. The optical laminate of the present invention is preferably used as a front plate in a flexible image display apparatus, and the front plate may be referred to as a window film. The flexible image display device includes a flexible image display device laminate and an organic EL display panel. The flexible image display device laminate is arranged on the viewing side with respect to the organic EL display panel, and is configured to be bendable. ing. The laminate for a flexible image display device may further contain a polarizing plate, preferably a circular polarizing plate, and a touch sensor, and the order of stacking thereof is arbitrary. Or it is preferable to laminate | stack in order of a window film, a touch sensor, and a polarizing plate. It is preferable that the polarizing plate is present on the viewing side of the touch sensor because the touch sensor pattern is less visible and the visibility of the display image is improved. Each member can be laminated | stacked using an adhesive agent, an adhesive, etc. Moreover, the light-shielding pattern formed in at least one surface of the any one layer of the said window film, a polarizing plate, and a touch sensor can be comprised.

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

The linear polarizing plate is a functional layer having a function of blocking polarized light having a vibration component perpendicular to the light that is oscillating in the transmission axis direction. The linear polarizing plate may include a linear polarizer alone or a linear polarizer and a protective film attached to at least one surface thereof. The linear polarizing plate may have a thickness of 200 μm or less, preferably 0.5 to 100 μm. When the thickness of the linearly polarizing plate is in the above range, the flexibility of the linearly polarizing plate tends to be difficult to decrease.
The linear polarizer may be a film-type polarizer manufactured by dyeing and stretching a polyvinyl alcohol (hereinafter abbreviated as PVA) film. A dichroic dye such as iodine is adsorbed on a PVA-based film oriented by stretching or is stretched in a state of being adsorbed to PVA, whereby the dichroic dye is oriented and exhibits polarizing performance. In the production of the film-type polarizer, other processes such as swelling, crosslinking with boric acid, washing with an aqueous solution, and drying may be included. The stretching or dyeing process may be performed by a PVA film alone or in a state where it is laminated with another film such as polyethylene terephthalate. The film thickness of the PVA film used is preferably 10 to 100 μm, and the draw ratio is preferably 2 to 10 times.
Furthermore, as another example of the polarizer, there is a liquid crystal coating type polarizer formed by coating a liquid crystal polarizing composition. The liquid crystal polarizing composition may include a liquid crystal compound and a dichroic dye compound. The liquid crystalline compound only needs to have the property of exhibiting a liquid crystal state. In particular, the liquid crystalline compound preferably has a higher-order alignment state such as a smectic phase because it can exhibit high polarization performance. The liquid crystalline compound preferably has a polymerizable functional group.
The dichroic dye compound is a dye that is aligned with the liquid crystal compound and exhibits dichroism, and may have a polymerizable functional group, and the dichroic dye itself has liquid crystallinity. It may be.
Any of the compounds contained in the liquid crystal polarizing composition has a polymerizable functional group. The liquid crystal polarizing composition may further contain an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like.

The liquid crystal polarizing layer is manufactured by applying a liquid crystal polarizing composition on an alignment film to form a liquid crystal polarizing layer. The liquid crystal polarizing layer can be formed thinner than a film-type polarizer, and the thickness is preferably 0.5 to 10 μm, more preferably 1 to 5 μm.
The alignment film is produced, for example, by applying an alignment film forming composition on a substrate and imparting alignment by rubbing, polarized light irradiation, or the like. The alignment film forming composition contains an alignment agent, and may further contain a solvent, a crosslinking agent, an initiator, a dispersant, a leveling agent, a silane coupling agent, and the like. Examples of the aligning agent include polyvinyl alcohols, polyacrylates, polyamic acids, and polyimides. When using an aligning agent that imparts orientation by polarized light irradiation, it is preferable to use an aligning agent containing a cinnamate group. The weight average molecular weight of the polymer used as the alignment agent is, for example, about 10,000 to 1,000,000. The thickness of the alignment film is preferably 5 to 10,000 nm, and more preferably 10 to 500 nm from the viewpoint that the alignment regulating force is sufficiently developed.
The liquid crystal polarizing layer can be peeled off from the base material, transferred and laminated, or the base material can be laminated as it is. It is also preferable that the base material plays a role as a transparent base material for a protective film, a phase difference plate, or a window film.
The protective film may be a transparent polymer film, and the same materials and additives used for the transparent substrate of the window film can be used. Moreover, the coating-type protective film obtained by apply | coating and hardening | curing radical curing compositions, such as cationic curing compositions, such as an epoxy resin, and an acrylate, may be sufficient. The protective film may be a plasticizer, an ultraviolet absorber, an infrared absorber, a colorant such as a pigment or a dye, a fluorescent brightener, a dispersant, a heat stabilizer, a light stabilizer, an antistatic agent, or an antioxidant, if necessary. Further, it may contain a lubricant, a solvent and the like. The thickness of the protective film is preferably 200 μm or less, more preferably 1 to 100 μm. When the thickness of the protective film is in the above range, the flexibility of the film tends to be difficult to decrease.

The λ / 4 phase difference plate is a film that gives a phase difference of λ / 4 in a direction (in-plane direction of the film) perpendicular to the traveling direction of incident light. The λ / 4 retardation plate may be a stretched retardation plate manufactured by stretching a polymer film such as a cellulose film, an olefin film, or a polycarbonate film. If necessary, the λ / 4 retardation plate is a retardation adjusting agent, a plasticizer, an ultraviolet absorber, an infrared absorber, a colorant such as a pigment or a dye, a fluorescent brightener, a dispersant, a heat stabilizer, and a light stabilizer. Agents, antistatic agents, antioxidants, lubricants, solvents and the like may be included.
The thickness of the stretchable phase difference plate is preferably 200 μm or less, more preferably 1 to 100 μm. When the thickness of the stretchable retardation plate is in the above range, the flexibility of the stretchable retardation plate tends to be difficult to decrease.
Furthermore, another example of the λ / 4 retardation plate is a liquid crystal coating type retardation plate formed by coating a liquid crystal composition.
The liquid crystal composition includes a liquid crystal compound exhibiting a liquid crystal state such as nematic, cholesteric, and smectic. The liquid crystalline compound has a polymerizable functional group.
The liquid crystal composition may further contain an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like.

The liquid crystal coating type retardation plate can be produced by coating and curing a liquid crystal composition on a base to form a liquid crystal retardation layer, similarly to the liquid crystal polarizing layer. The liquid crystal coated retardation plate can be formed thinner than the stretched retardation plate. The thickness of the liquid crystal polarizing layer is preferably 0.5 to 10 μm, more preferably 1 to 5 μm.
The liquid crystal coating type retardation plate can be peeled off from the substrate, transferred, and laminated, or the substrate can be laminated as it is. It is also preferable that the base material plays a role as a transparent base material for a protective film, a phase difference plate, or a window film.
In general, there are many materials that exhibit higher birefringence as the wavelength is shorter and smaller birefringence as the wavelength is longer. In this case, since the phase difference of λ / 4 cannot be achieved in the entire visible light region, the in-plane phase difference is preferably 100 to λ / 4 with respect to the vicinity of 560 nm where the visibility is high. It is designed to be 180 nm, more preferably 130 to 150 nm. A reverse dispersion λ / 4 retardation plate using a material having a birefringence wavelength dispersion characteristic opposite to that of a normal one is preferable in terms of good visibility. As such a material, for example, those described in Japanese Patent Application Laid-Open No. 2007-232873 can be used for the stretchable phase difference plate, and those described in Japanese Patent Application Laid-Open No. 2010-30979 can be used for the liquid crystal coating type phase difference plate. .
As another method, a technique for obtaining a broadband λ / 4 phase difference plate by combining with a λ / 2 phase difference plate is also known (for example, JP-A-10-90521). The λ / 2 phase difference plate is also manufactured by the same material method as the λ / 4 phase difference plate. Although the combination of the stretching type retardation plate and the liquid crystal coating type retardation plate is arbitrary, the film thickness can be reduced by using the liquid crystal coating type retardation plate.
A method of laminating a positive C plate on the circularly 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 coated retardation plate or a stretched retardation plate. The retardation in the thickness direction of the retardation plate is preferably −200 to −20 nm, more preferably −140 to −40 nm.

[Touch sensor]
As described above, the flexible image display device of the present invention preferably includes a touch sensor. The touch sensor is used as input means. Examples of the touch sensor include various types such as a resistive film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, a capacitance method, and preferably a capacitance method.
The capacitive touch sensor is divided into an active region and a non-active region located in an outer portion of the active region. The active area is an area corresponding to an area (display unit) where the screen is displayed on the display panel, and is an area where a user's touch is sensed. An inactive area is an area where the screen is not displayed on the display device (non-display area). This is a region corresponding to the display unit. The touch sensor is formed of a flexible substrate, a sensing pattern formed in an active region of the substrate, and a non-active region of the substrate, and is connected to an external driving circuit through the sensing pattern and a pad portion. Each sensing line can be included. As the substrate having flexible characteristics, the same material as the transparent substrate of the window film can be used.

  The sensing pattern may include a first pattern formed in a first direction and a second pattern formed in a second direction. The first pattern and the second pattern are arranged in different directions. The first pattern and the second pattern are formed in the same layer, and each pattern must be electrically connected in order to sense a touched point. The first pattern is a form in which a plurality of unit patterns are connected to each other 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. A separate bridge electrode is required to connect them. A well-known transparent electrode can be applied to the electrode for connecting the second pattern. Examples of the material for the transparent electrode include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), PEDOT (poly (3,4-ethylenedithiothiophene)), carbon nanotube (CNT), graphene, metal wire, and the like can be given, and ITO is preferred. These can be used individually or in mixture of 2 or more types. The metal used for the metal wire is not particularly limited, and examples thereof include silver, gold, aluminum, copper, iron, nickel, titanium, telenium, and chromium. These may be used alone or in combination of two or more. Can do.

The bridge electrode may be formed on the sensing pattern with an insulating layer interposed therebetween. The bridge electrode may be formed on the substrate, and the insulating layer and the sensing pattern may be formed thereon. The bridge electrode may be formed of the same material as the sensing pattern, and may be formed of molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or an alloy of two or more 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 can be formed only between the joint of the first pattern and the bridge electrode, or can be formed as a layer covering the entire sensing pattern. In the case of a layer covering the entire sensing pattern, the bridge electrode can be connected to the second pattern through a contact hole formed in the insulating layer.

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

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

  As the water-based solvent volatilization type adhesive, water-soluble polymers such as polyvinyl alcohol polymers and starches, water-dispersed polymers such as ethylene-vinyl acetate emulsions and styrene-butadiene emulsions can be used as the main polymer. In addition to the main polymer and water, a crosslinking agent, a silane compound, an ionic compound, a crosslinking catalyst, an antioxidant, a dye, a pigment, an inorganic filler, an organic solvent, and the like may be blended. In the case of bonding with the water-based solvent volatile adhesive, the water-based solvent volatile adhesive can be injected between the layers to be bonded, and the adhesion layer can be bonded, and then dried to provide adhesion. When using the said water-system solvent volatilization-type adhesive agent, the thickness of the contact bonding layer becomes like this. Preferably it is 0.01-10 micrometers, More preferably, it is 0.1-1 micrometers. When the aqueous solvent volatile adhesive is used in a plurality of layers, the thickness of each layer and the type of aqueous solvent volatile 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 irradiates active energy rays to form an adhesive layer. The active energy ray-curable composition can contain at least one polymer of a radical polymerizable compound and a cationic polymerizable compound similar to those contained in the hard coat composition. As the radical polymerizable compound, the same compound as the radical polymerizable compound in the hard coat composition can be used.
As the cationic polymerizable compound, the same compound as the cationic polymerizable compound in the hard coat composition can be used.
As the cationic polymerizable compound used in the active energy ray-curable composition, an epoxy compound is particularly preferable. In order to reduce the viscosity of the adhesive composition, it is also preferable to include a monofunctional compound as a reactive diluent.
The active energy ray composition can contain a monofunctional compound in order to reduce the viscosity. Examples of the monofunctional compound include an acrylate monomer having one (meth) acryloyl group in one molecule, a compound having one epoxy group or oxetanyl group in one molecule, such as glycidyl (meta ) Acrylate and the like.
The active energy ray composition can further contain a polymerization initiator. Examples of the polymerization initiator include radical polymerization initiators, cationic polymerization initiators, radicals and cationic polymerization initiators, and these are appropriately selected and used. These polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate radicals or cations to advance radical polymerization and cationic polymerization. In the description of the hard coat composition, an initiator capable of initiating at least one of radical polymerization or cationic polymerization by active energy ray irradiation can be used.
The active energy ray curable composition further includes an ion scavenger, an antioxidant, a chain transfer agent, an adhesion promoter, a thermoplastic resin, a filler, a flow viscosity modifier, a plasticizer, an antifoaming solvent, an additive, a solvent. Can be included. When adhering two adherend layers with the active energy ray curable adhesive, the active energy ray curable composition is applied to one or both of the adherend layers and then bonded, and either adherend layer is applied. Alternatively, both of the adherend layers can be bonded together by irradiating them with active energy rays and curing them. When using the said active energy ray hardening-type adhesive agent, the thickness of the contact bonding layer becomes like this. Preferably it is 0.01-20 micrometers, More preferably, it is 0.1-10 micrometers. When the active energy ray-curable adhesive is used for forming a plurality of adhesive layers, the thickness of each layer and the type of active energy ray-curable adhesive used may be the same or different.
As the adhesive, the same adhesive as the above-mentioned adhesive 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 light shielding pattern can be applied as at least part of a bezel or a housing of the flexible image display device. The visibility of the image is improved by concealing the wiring arranged at the edge portion of the flexible image display device by the light shielding pattern and making it difficult to see. The light shielding pattern may be a single layer or a multilayer. The color of the light shielding pattern is not particularly limited, and may be various colors such as black, white, and metal color. The light shielding pattern can be formed of a pigment for embodying a color and a polymer such as an acrylic resin, an ester resin, an epoxy resin, polyurethane, or silicone. These can be used alone or in a mixture of two or more. The light shielding pattern can be formed by various methods such as printing, lithography, and inkjet. The thickness of the light shielding pattern is preferably 1 to 100 μm, more preferably 2 to 50 μm. It is also preferable to give a shape such as an inclination in the thickness direction of the light shielding pattern.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

1. Measurement method and evaluation (1) Yellowness (YI value)
Using a spectrophotometer (U-4100) manufactured by Hitachi, Ltd., the tristimulus values X, Y and Z calculated by the calculation method defined in JIS Z 8701: 1982 and the following formula are used. 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 considered very good and marked with ◎.
Those satisfying 3 <YI ≦ 10 were regarded as good and indicated by ○.
A case where 10 <YI was regarded as defective and indicated by x.

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

(3) Pencil Hardness Pencil hardness on the hard coat surface side of the optical laminate was measured in accordance with JIS K 5600-5-4: 1999 using a uni from Mitsubishi Pencil Co., Ltd. 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 pencil hardness was determined by evaluating the presence or absence of scratches under an illuminance condition of 4,000 lux. 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. Specific measurement conditions were as follows.
a. Pretreatment method DMF eluent (10 mM lithium bromide solution) is added to polyamideimide (sample) to a concentration of 2 mg / mL, heated at 80 ° C. with stirring for 30 minutes, cooled, and then 0.45 μm membrane. A solution obtained by filtration through a filter was used as a measurement solution.
b. Measurement conditions Column: TSKgel SuperAWM-H × 2 + SuperAW2500 × 1 (6.0 mm ID × 150 mm × 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 (Mitutoyo), and the thickness of the hard coat layer was measured with a F20 tabletop film thickness system manufactured by Filmmetrics.

2. Ultraviolet absorber The following ultraviolet absorber was prepared.
Sumisorb 340 (trade name: manufactured by Sumitomo Chemical Co., Ltd., 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole)

3. Polyamide resin (1) Polyamideimide A (6FDA / TPC / BPDA = 3/6/1 (molar ratio))
Under a nitrogen gas atmosphere, in a 1 L separable flask equipped with a stirring blade, 53.05 g (165.66 mmol) of 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl (TFMB) and N, N -670.91 g of dimethylacetamide (hereinafter sometimes referred to as DMAc) was added, and TFMB was dissolved in DMAc while stirring at room temperature. The flask was then charged with 22.4 g (49.77 mmol) of 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. 4.88 g (16.59 mmol) of the product (BPDA) was added, and then 20.21 g (99.54 mmol) of terephthaloyl chloride (TPC) was added and 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, stirred at room temperature for 30 minutes, then heated to 70 ° C. using an oil bath, and further 3 hours Stir to obtain a reaction solution.
The resulting reaction solution was cooled to room temperature, poured into a large amount of methanol in the form of a thread, the deposited precipitate was taken out, immersed in methanol for 6 hours, and washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C. to obtain polyamideimide A. The weight average molecular weight of polyamideimide A was 190,000.

(2) Polyamideimide 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). And 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, stirred at room temperature for 30 minutes, heated to 70 ° C. using an oil bath, The mixture was stirred for 3 hours to obtain a reaction solution.
The resulting reaction solution was cooled to room temperature, poured into a large amount of methanol in the form of a thread, the deposited precipitate was taken out, immersed in methanol for 6 hours, and washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C. to obtain polyamideimide B. The weight average molecular weight of polyamideimide B was 430,000.

4). Inorganic particles A γ-butyrolactone (hereinafter sometimes referred to as GBL) substituted silica sol obtained by solvent substitution using an amorphous silica sol having a BET diameter of 27 nm prepared by a sol-gel method as a raw material was used. In any of the obtained GBL-substituted silica sols, the silica component (inorganic particles) was 30% by mass.

5. Curable composition (hard coat composition)
The following curable composition (hard coat composition) was prepared.
Z-850-AFH (acrylic hard coat) manufactured by Aika Industry Co., Ltd.

[Example 1]
Polyamideimide A was diluted with DMAc to prepare a polyamideimide 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 stirred for 30 minutes. The content of the ultraviolet absorber was 5.5 parts by mass with respect to 100 parts by mass of polyamideimide A. The obtained polyamideimide varnish containing the ultraviolet absorber was applied on a smooth surface of a polyester base material (trade name “A4100” manufactured by Toyobo Co., Ltd.) using an applicator so that the film thickness of the free-standing film was 55 μm. After drying at 50 ° C. for 30 minutes and then at 140 ° C. for 15 minutes, the obtained coating film was peeled from the polyester substrate to obtain a self-supporting film. The self-supporting film was fixed to a metal frame, and further dried in the atmosphere at 300 ° C. for 40 minutes to obtain a polyamideimide film (base film) having a thickness of 50 μm.
The hard coat composition was applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then irradiated with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) in a nitrogen atmosphere and cured. As a result, a coating film was formed to obtain an optical laminate. The film thickness of the hard coat layer was 10 μm. The optical laminate had a light transmittance of 1.9 nm of 11.9%.

[Example 2]
A polyamide-imide varnish having a concentration of 9.5% by mass was prepared by diluting polyamide-imide B in a solution obtained by dissolving an ultraviolet absorber [Sumisorb 340, manufactured by Sumika Chemical Co., Ltd.] in a GBL solution. The content of the ultraviolet absorber was 5.5 parts by mass with respect to 100 parts by mass of polyamideimide B. The obtained polyamideimide varnish containing the ultraviolet absorber was applied on a smooth surface of a polyester base material (trade name “A4100” manufactured by Toyobo Co., Ltd.) using an applicator so that the film thickness of the free-standing film was 55 μm. After drying at 50 ° C. for 30 minutes and then at 140 ° C. for 15 minutes, the obtained coating film was peeled from the polyester substrate to obtain a self-supporting film. The self-supporting film was fixed to a metal frame, and further dried in the atmosphere at 200 ° C. for 40 minutes to obtain a polyamideimide film (base film) having a thickness of 50 μm.
The hard coat composition was applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then irradiated with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) in a nitrogen atmosphere and cured. As a result, a coating film was formed to obtain an optical laminate. The film thickness of the hard coat layer was 10 μm. The light transmittance at 390 nm of the optical laminate 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 polyamideimide 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 for 390 nm light was 17.5%. The content of the silica sol was 50 parts by mass with respect to 100 parts by mass of polyamideimide B.

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

[Example 5]
A polyamide-imide varnish having a concentration of 9.5% by mass was prepared by diluting polyamide-imide B in a solution obtained by dissolving an ultraviolet absorber [Sumisorb 340, manufactured by Sumika Chemical Co., Ltd.] in a GBL solution. The content of the ultraviolet absorber was 2.0 parts by mass with respect to 100 parts by mass of polyamideimide B. The obtained polyamideimide varnish containing an ultraviolet absorber was applied on a smooth surface of a polyester base material (trade name “A4100”, manufactured by Toyobo Co., Ltd.) using an applicator so that the film thickness of the self-supporting film became 55 μm, and 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 metal frame, and further dried in the atmosphere at 200 ° C. for 40 minutes to obtain a polyamideimide film (base film) having a thickness of 50 μm.
The hard coat composition was applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then irradiated with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) in a nitrogen atmosphere and cured. As a result, a coating film was formed to obtain an optical laminate. The film thickness of the hard coat layer was 10 μm. The light transmittance at 390 nm of the optical laminate was 45.3%.

[Example 6]
Polyamideimide B added with GBL-substituted silica sol is diluted with a solution obtained by dissolving an ultraviolet absorber [hydroxyphenyltriazine derivative, “Tinvin 479”, manufactured by BASF Corp.] in a GBL solution to a polyamide having a concentration of 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 polyamideimide B. The obtained polyamideimide varnish containing the ultraviolet absorber was applied on a smooth surface of a polyester base material (trade name “A4100” manufactured by Toyobo Co., Ltd.) using an applicator so that the film thickness of the free-standing film was 55 μm. After drying at 50 ° C. for 30 minutes and then at 140 ° C. for 15 minutes, the obtained coating film was peeled from the polyester substrate to obtain a self-supporting film. The self-supporting film was fixed to a metal frame, and further dried in the atmosphere at 200 ° C. for 40 minutes to obtain a polyamideimide 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 polyamideimide B.
The hard coat composition was applied to one side of the obtained base film with a bar coater, dried at 80 ° C. for 3 minutes, and then irradiated with a high-pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) in a nitrogen atmosphere and cured. As a result, a coating film was formed to obtain an optical laminate. The film thickness of the hard coat layer was 10 μm. The light transmittance at 390 nm of the optical laminate was 58.1%.

[Comparative Example 1]
Polyamideimide A was diluted with DMAc to prepare a polyamideimide varnish having a concentration of 22% by mass. The obtained polyimide varnish was applied on a smooth surface of a polyester base material (trade name “A4100”, manufactured by Toyobo Co., Ltd.) using an applicator so that the film thickness of the self-supporting film was 55 μm, and 30 minutes at 50 ° C. Then, after drying at 140 ° C. for 15 minutes, the obtained coating film was peeled from the polyester substrate to obtain a self-supporting film. The self-supporting film was fixed to a metal frame, and further dried in the atmosphere at 300 ° C. for 40 minutes to obtain a polyamideimide film (base film) having a thickness of 50 μm.
A hard coat composition containing an ultraviolet absorber, in which Sumisorb 340 [manufactured by Sumika Chemical Co., Ltd.] was added to the hard coat composition used in Example 1, was applied to the obtained base film with a bar coater. Then, after drying at 80 ° C. for 3 minutes, a high pressure mercury lamp (500 mJ / cm ² , 200 mW / cm ² ) was irradiated and cured in a nitrogen atmosphere to form a coating film 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 hard coat composition.

  Table 1 shows the results of measuring the YI value and pencil hardness of the optical laminates obtained in Examples 1 to 6 and Comparative Example 1.

  It was confirmed that the optical laminates of Examples 1 to 6 had significantly higher pencil hardness than the optical laminate of Comparative Example 1. In addition, 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 YI evaluation. Was confirmed. Therefore, the optical laminated bodies of Examples 1 to 6 have excellent surface hardness and excellent transparency. Moreover, it turned out that the optical laminated body of Examples 1-3 is low in the light transmittance in 390 nm, and also is excellent in ultraviolet-ray absorptivity.

DESCRIPTION OF SYMBOLS 1 ... Optical laminated body 2 ... Base film 3 ... Hard-coat layer

Claims (11)

An optical laminate having a base film containing polyamideimide and an aromatic compound, and a hard coat layer on at least one surface of the base film, wherein the polyamideimide has the formula (1) and formula (2) :
[In Formula (1) and Formula (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 formula (2) is 0.1 to 3.9 moles per mole of the structural unit represented by formula (1). Yes, the thickness of the base film is 10 to 200 μm, the thickness of the hard coat layer is 1 to 20 μm, and the yellowness of the optical laminate is 5 or less.   The optical laminate according to claim 1, wherein the aromatic compound is an ultraviolet absorber.   The optical laminate according to claim 2, wherein the content of the ultraviolet absorber is 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyamideimide.   The optical laminate according to claim 2 or 3, 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 polyamideimide is an optical laminate according to any one of claims 1 to 4, wherein the weight average molecular weight in terms of standard polystyrene is 5,000 to 800,000.   The optical laminate according to any one of claims 1 to 5, wherein the base film contains inorganic particles.   The optical layered body according to any one of claims 1 to 6, wherein the light transmittance at 390 nm is 35% or less. Polyamideimide has formulas (1) and (2):
[In Formula (1) and Formula (2), X and Z each independently represent a divalent organic group, Y represents a tetravalent organic group,
At least part of Z is represented by formula (3):
(In Formula (3), R < ¹ > -R < ⁸ > represents a hydrogen atom, a C1-C6 alkyl group, or a C6-C12 aryl group each independently, and hydrogen contained in R < ¹ > -R < ⁸ >. Each atom may be independently substituted with a halogen atom,
A represents —O—, —S—, —CO— or —N (R ⁹ ) —, wherein 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.)
Represented by
The optical laminated body in any one of Claims 1-7 which has a structural unit represented by these.   A flexible image display apparatus provided with the optical laminated body in any one of Claims 1-8.   Furthermore, the flexible image display apparatus of Claim 9 containing a polarizing plate.   The flexible image display device according to claim 9, further comprising a touch sensor.