KR20210110646A - Optical film, flexible display device, and polyamideimide-based resin - Google Patents

Abstract

An optical film having a high modulus of elasticity and a low coefficient of expansion at humidity is provided. Formula (1): a structural unit represented by [in Formula (1), Ar ¹ represents a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms, X represents a divalent organic group]; 2): Contains a polyamideimide-based resin having a weight average molecular weight of 200,000 to 1,000,000 having at least a structural unit represented by [in formula (2), X represents a divalent organic group and Y represents a tetravalent organic group] optical film.

Description

Optical film, flexible display device, and polyamideimide-based resin

The present invention relates to an optical film containing a polyamideimide-based resin, a flexible display device including the optical film, and a polyamideimide-based resin.

BACKGROUND ART At present, display devices such as a liquid crystal display device and an organic EL display device are widely utilized not only for televisions but also for various uses such as mobile phones and smart watches. Conventionally, glass has been used as a front plate of such a display device. However, while glass has high transparency and can exhibit high hardness depending on the type, it is very rigid and brittle, so it is difficult to use it as a front panel material for a flexible display device.

Therefore, the utilization of a polymer material as a material instead of glass is examined. Since the front plate made of a polymer material easily exhibits flexible properties, it is expected to be used for various purposes. As one of the flexible polymer materials, for example, an optical film using a polyamideimide-based resin has been studied (Patent Documents 1 and 2).

Japanese Patent Publication No. 2015-521686 Japanese Patent Laid-Open No. 2018-119132

However, when an optical film using a polyamideimide-based resin is used in a flexible display device or the like, defects such as scratches and wrinkles may occur in the optical film due to bending or contact with external factors. MEANS TO SOLVE THE PROBLEM This inventor examined various means for improving the above, and discovered that defects, such as a flaw, did not produce easily in an optical film by raising the elastic modulus of an optical film. Moreover, although a flexible display device is what is used under various environments over a long period of time, the optical film to which the load was applied especially with changes, such as temperature and humidity, may expand-contract in the planar direction. Therefore, it is also calculated|required that an optical film has a low humidity expansion coefficient with respect to the change of temperature and humidity.

Therefore, this invention makes it a subject to provide the optical film which has a high elastic modulus and low humidity expansion coefficient.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the present inventors paid attention to the structure of the monomer which comprises polyamideimide-type resin contained in an optical film, and earnestly examined it. As a result, it was found that an optical film comprising a polyamideimide-based resin having at least a specific structural unit and having a weight average molecular weight within a specific range has both a high modulus of elasticity and a low coefficient of expansion at low humidity. reached

That is, the present invention includes the following suitable aspects.

[1] Formula (1):

[Formula 1]

[In formula (1), Ar ¹ represents a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms, and X represents a divalent organic group]

A structural unit represented by, and Formula (2):

[Formula 2]

[In formula (2), X represents a divalent organic group, Y represents a tetravalent organic group]

An optical film comprising a polyamideimide-based resin having at least a structural unit represented by and having a weight average molecular weight of 200,000 to 1,000,000.

[2] The optical film according to [1], wherein the fluoroalkyl group having 1 to 12 carbon atoms ^{in Ar 1 in the formula (1) is a perfluoroalkyl group having 1 to 12 carbon atoms.}

[3] The structural unit represented by Formula (1) is Ar ¹ , and Formula (4):

[Formula 3]

[In formula (4),

R ¹ represents a fluoroalkyl group having 1 to 12 carbon atoms,

n and k independently represent an integer of 1 to 4, provided that when n and/or k represent an integer of 2 to 4, a plurality of R ¹ may be the same or different from each other,

* indicates a bonding hand]

The optical film according to [1] or [2], comprising an aromatic group represented by .

[4] The optical film according to [3], wherein the two bonds in the formula (4) are located in a para position to each other.

[5] The optical film according to [3] or [4], wherein k in formula (4) is 1 or 2.

^{[6] The optical film according to any one of [3] to [5], wherein R 1} in the formula (4) represents a perfluoroalkyl group having 1 to 12 carbon atoms, and n is 1 or 2.

[7] The structural unit represented by Formula (1) and/or the structural unit represented by Formula (2) is X, and Formula (5):

[Formula 4]

[In formula (5),

Ar ² represents a divalent aromatic group which may have a substituent,

V is a single bond, -O-, a diphenylmethylene group, a fluorenyl group, a divalent hydrocarbon group having 1 to 12 carbon atoms, -SO ₂ -, -S-, -CO-, -PO-, -PO ₂ -, represents -N(R ^a )- or -Si(R ^b ) ₂ -, wherein the hydrocarbon group may contain an alicyclic structure, and the hydrogen atoms contained in the hydrocarbon group are, independently of each other, to the halogen atom may be substituted with, and R ^a and R ^b each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom,

m represents an integer of 0 to 3,

* indicates a bonding hand]

The optical film according to any one of [1] to [6], comprising a divalent organic group represented by .

[8] The optical film according to the above [7], wherein m in the formula (5) is 1.

[9] The structural unit represented by Formula (1) and/or the structural unit represented by Formula (2) is X, and Formula (5a):

[Formula 5]

[In formula (5),

R ² represents a fluoroalkyl group having 1 to 12 carbon atoms,

p and q each independently represent an integer of 1 to 4, provided that, when p and/or q represents an integer of 2 to 4, ^{two or} more R 2 may be the same as or different from each other,

* indicates a bonding hand]

The optical film according to any one of [1] to [6], comprising a divalent organic group represented by .

[10] The structural unit represented by Formula (1) and/or the structural unit represented by Formula (2) is X, wherein Formula (5c):

[Formula 6]

[* in formula (5c) represents a bond]

The optical film in any one of Claims 1-6 containing the divalent organic group represented by.

[11] The optical film according to any one of [1] to [10], wherein the thickness is 10-200 µm.

[12] A flexible display device comprising the film according to any one of [1] to [11].

[13] The flexible display device according to [12], further comprising a touch sensor.

[14] The flexible display device according to [12] or [13], further comprising a polarizing plate.

[15] Formula (1):

[Formula 7]

[In formula (1),

Ar ¹ represents a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms,

X represents a divalent organic group]

^{, and as Ar 1} in Formula (1), Formula (4):

[Formula 8]

[in formula (4),

R ¹ represents a fluoroalkyl group having 1 to 12 carbon atoms,

n and k independently represent an integer of 1 to 4, provided that when n and/or k represent an integer of 2 to 4, a plurality of R ¹ may be the same or different from each other,

* indicates a bond]

A structural unit comprising an aromatic group represented by, and Formula (2):

[Formula 9]

[In formula (2), X represents a divalent organic group, Y represents a tetravalent organic group]

A polyamideimide-based resin having at least a structural unit represented by and having a weight average molecular weight of 200,000 to 1,000,000.

The optical film of the present invention has a high modulus of elasticity and a low coefficient of expansion at humidity.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail. In addition, the scope of the present invention is not limited to the embodiments described herein, and various changes can be made without departing from the spirit of the present invention.

The optical film of the present invention, Formula (1):

[Formula 10]

[In formula (1), Ar ¹ represents a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms, and X represents a divalent organic group]

A structural unit represented by, and Formula (2):

[Formula 11]

[In formula (2), X represents a divalent organic group, Y represents a tetravalent organic group]

and a polyamideimide-based resin having a weight average molecular weight of 200,000 to 1,000,000 having at least a structural unit represented by . The structural unit represented by Formula (1) is a structural unit formed by reacting a dicarboxylic acid compound with a diamine compound, and the structural unit represented by Formula (2) is a structural unit formed by reacting a tetracarboxylic acid compound with a diamine compound. is a constituent unit. The polyamideimide-type resin contained in the optical film of this invention may have one type of structural unit represented by Formula (1), and may have two or more types of structural units represented by Formula (1). Similarly, the said polyamideimide-type resin may have one type of structural unit represented by Formula (2), and may have two or more types of structural units represented by Formula (2). In this specification, the structural unit represented by Formula (1) is also called "structural unit (1)", and the structural unit represented by Formula (2) is also called "structural unit (2)." In addition, in Formula (1) and Formula (2), the bond shown by the dotted line represents the bond couple|bonded with the adjacent structural unit. In this specification, the bond shown by the dotted line in other chemical structural formula also shows the bond couple|bonded with the adjacent structural unit or group similarly.

In the optical film of the present invention comprising a polyamideimide-based resin having a weight average molecular weight of 200,000 to 1,000,000 having the structural units (1) and (2) as described above, the elastic modulus is improved and the humidity expansion coefficient is reduced Although it is not clear why this can be done, in the skeleton of the polyamideimide-based resin having a predetermined weight average molecular weight, Ar ¹ in the above formula (1) is a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms. Accordingly, it is considered that a specific portion of the skeleton of the polyamideimide-based resin has an appropriate degree of rigidity and intermolecular repulsion. As a result, surprisingly, it is thought that both the improvement of the elastic modulus of the optical film containing this polyamideimide-type resin and the reduction of the humidity expansion coefficient are achieved. The coefficient of humidity expansion is an index indicating the degree of expansion in the plane direction of the optical film under a load, and it has become clear that the molecular structure of the polyamideimide-based resin constituting the optical film greatly affects the coefficient of humidity expansion. And it became clear that it may be difficult to make the high elastic modulus of an optical film and the low humidity expansion coefficient compatible only by increasing the structure which has a halogen atom. In the present invention, a polyamideimide system having at least a structural unit (1) containing a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms and a structural unit (2), and having a weight average molecular weight within a predetermined range. It discovered that the optical film which has both a high elastic modulus and low humidity expansion coefficient with the optical film containing resin was obtained.

The polyamideimide-type resin contained in the optical film of this invention has a structural unit (1) and a structural unit (2). From the viewpoint that the elastic modulus of the optical film is easily increased and the humidity expansion coefficient is easily reduced, when the total of the structural units (1) and (2) contained in the polyamideimide-based resin is 100 mol%, the structural units ( The proportion of 1) is preferably 20 to 99 mol%, more preferably 30 to 98 mol%, still more preferably 40 to 95 mol%, particularly preferably 50 to 93 mol%. When the ratio of the structural unit (1) is more than the said lower limit, it is easy to raise the elasticity modulus of an optical film, and it is easy to reduce a humidity expansion coefficient. Moreover, when the ratio of structural unit (1) is below the said upper limit, it is easy to ensure the solubility to the solvent of resin. In addition, content of structural unit (1) and structural unit (2) ^{can be measured using 1} H-NMR, for example, or can also be computed from the introduction ratio of a raw material.

In the polyamideimide-based resin, the content of the structural unit represented by the formula (1) is preferably 0.1 mol or more, more preferably 0.5 mol or more, with respect to 1 mol of the structural unit represented by the formula (2), More preferably, it is 1.0 mol or more, Especially preferably, it is 1.5 mol or more, Preferably it is 6.0 mol or less, More preferably, it is 5.0 mol or less, More preferably, it is 4.5 mol or less. It is easy to raise the elasticity modulus of an optical film as content of the structural unit represented by Formula (1) is more than the said minimum, and it is easy to reduce a humidity expansion coefficient. Moreover, the thickening by the hydrogen bond between the amide bonds in Formula (1) as content of the structural unit represented by Formula (1) is below the said upper limit is suppressed and it will be easy to improve the workability of an optical film.

^{Ar 1} in the structural unit (1) represents a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms. In the present specification, the divalent aromatic group is a group in which two hydrogen atoms of a monocyclic aromatic ring, a condensed polycyclic aromatic ring, or a ring aggregated aromatic ring are substituted with a bond. The divalent aromatic group may include an aromatic ring in which a ring (monocyclic, condensed polycyclic or ring set) is formed only by carbon atoms, or may include a heteroaromatic ring in which a ring is formed including atoms other than carbon atoms. As atoms other than a carbon atom, a nitrogen atom, a sulfur atom, and an oxygen atom are mentioned, for example. Although the total number of the carbon atoms which form an aromatic ring and atoms other than a carbon atom is not specifically limited, Preferably it is 5-18, More preferably, it is 5-14, More preferably, it is 5-12.

Examples of the monocyclic aromatic ring include benzene, furan, pyrrole, thiophene, pyridine, imidazole, pyrazole, oxazole, thiazole and imidazoline.

Examples of the condensed polycyclic aromatic ring include naphthalene, anthracene, phenanthrene, indole, benzothiazole, benzimidazole, and benzoxazole.

Examples of the ring-aggregated aromatic ring include a structure in which two or more monocyclic aromatic rings and/or fused polycyclic aromatic rings are connected by a single bond, and examples thereof include those described above as examples of monocyclic aromatic rings or fused polycyclic aromatic rings. Groups in which two or more of the rings are connected by a single bond, for example, biphenyl, terphenyl, quaterphenyl, binaphthyl, 1-phenylnaphthalene, 2-phenylnaphthalene, bipyridine, and the like are exemplified.

The divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms is preferably an aromatic hydrocarbon ring having a fluoroalkyl group having 1 to 12 carbon atoms from the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient. A group in which two hydrogen atoms are substituted by a bond, more preferably a group in which two hydrogen atoms of benzene, biphenyl, terphenyl or quaterphenyl having a fluoroalkyl group having 1 to 12 carbon atoms are substituted by a bond, more preferably Preferably, it is a group in which two hydrogen atoms of benzene or biphenyl having a fluoroalkyl group having 1 to 12 carbon atoms are substituted with a bond.

^{The fluoroalkyl group having 1 to 12 carbon atoms in Ar 1} in the formula (1) is a group in which at least one hydrogen atom of a linear or branched alkyl group having 1 to 12 carbon atoms is substituted with a fluorine atom. Examples of the linear or branched fluoroalkyl 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-pene. Tyl group, 2-methyl-butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group and n-de The group in which the at least 1 hydrogen atom in a real group etc. was substituted by the fluorine atom is mentioned. Specific examples of the fluoroalkyl group having 1 to 12 carbon atoms include, for example, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a fluoroethyl group, a difluoroethyl group, a trifluoroethyl group, a pentafluoroethyl group, A heptafluoropropyl group, a nonafluorobutyl group, etc. are mentioned. The carbon number of the fluoroalkyl group is preferably 1 to 6, more preferably 1 to 4, still more preferably 1 or 2.

The fluoroalkyl group having 1 to 12 carbon atoms is preferably a perfluoroalkyl group having 1 to 12 carbon atoms, more preferably a perfluoroalkyl group having 1 to 12 carbon atoms, from the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient. A perfluoroalkyl group, more preferably a perfluoroalkyl group having 1 to 4 carbon atoms, particularly preferably a trifluoromethyl group or a pentafluoroethyl group.

^{Ar 1} in Formula (1) should just have at least one C1-C12 fluoroalkyl group, Although the number is not specifically limited, From a viewpoint that it is easy to raise the elasticity modulus of an optical film and it is easy to reduce a humidity expansion coefficient, The ^{number of fluoroalkyl groups having 1 to 12 carbon atoms in Ar 1} , is preferably 1 to 4, more preferably 1 to 2. ^{When Ar 1} in Formula (1) has two or more C1-C12 fluoroalkyl groups, these may mutually be same or different.

^{Ar 1} in Formula (1) may further have another substituent other than a C1-C12 fluoroalkyl group. As another substituent, a C1-C6 alkyl group, a C1-C6 alkoxy group, or a C6-C12 aryl group is mentioned, for example.

In one preferred aspect of the present invention, the structural unit represented by Formula (1) is Ar ¹ from the viewpoint of easily increasing the elastic modulus of the optical film and easily reducing the humidity expansion coefficient, Formula (4):

[Formula 12]

[In formula (4),

R ¹ represents, independently of each other, a fluoroalkyl group having 1 to 12 carbon atoms,

n and k independently represent an integer of 1 to 4, provided that when n and/or k represent an integer of 2 to 4, a plurality of R ¹ may be the same or different from each other,

* indicates a bonding hand]

and a divalent aromatic group represented by When the structural unit (1) contains a divalent aromatic group represented by Formula (4) as ^{Ar 1} , the structural unit (1) includes one or more aromatic groups represented by Formula (4) as ^{Ar 1 .} Other than the aromatic group represented by Formula (4) other than the aromatic group represented by Formula (4) may be included and may contain the other aromatic group which has a fluoroalkyl group which does not correspond to the aromatic group represented by Formula (4).

The polyamideimide-based resin contained in the optical film of the present invention has at least a structural unit (1) and a structural unit (2) as described above, and the resin is usually a plurality of structural units (1) and a plurality of structural units. (2) and optionally other structural units. In the present specification, the fact that the structural unit (1) ^{contains an aromatic group represented by the formula (4) as Ar 1} means that, in the plurality of structural units (1) of the polyamideimide-based resin, at least a part of the structural unit ^{It means that Ar<1>} in (1) is represented by Formula (4). The above description also applies to other similar descriptions in this specification.

As the fluoroalkyl group having 1 to 12 carbon atoms in ^{R 1} , the above description regarding the fluoroalkyl group having 1 to 12 carbon atoms in ^{Ar 1 is similar, and preferred description is also similar.}

n and k each independently represent the integer of 1-4. n is preferably an integer of 1 or 2, more preferably 1, from the viewpoint of optical properties. From a viewpoint of an elastic modulus, k becomes like this. Preferably it is an integer of 1 or 2, More preferably, it is 1. Here, when n and/or k represents an integer of 2 to 4, a plurality of R ^1s may be the same or different from each other, but from the viewpoint of solubility in a solvent, a plurality of R ^1s are preferably the same do. From a viewpoint that it is easy to raise the elasticity modulus of an optical film and it is easy to reduce a humidity expansion coefficient, it is more preferable that k is 1 and n is 2, or that k is 2 and n is 1.

With respect to the two bonding hands in the formula (4), the position of each other is not particularly limited, and any of the ortho position, meta position, and para position may be used, but it is easy to increase the elastic modulus of the optical film and it is easy to reduce the humidity expansion coefficient From a standpoint, the binding hands are preferably positioned para to each other.

As a preferable example of the divalent aromatic group represented by Formula (4), R ¹ in Formula (4) represents a C1-C12 perfluoroalkyl group, k is 1 or 2, n is 1 or 2; and/or an aromatic group in which two bonding hands are located at a position para to each other.

A preferred embodiment of the present invention in which the structural unit represented by Formula (1) contained in the polyamideimide-based resin contained in the optical film of the present invention contains a divalent aromatic group represented by Formula (4) as ^{Ar 1 .} In the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient, when the total of the structural units represented by the formula (1) contained in the polyamideimide-based resin is 100 mol%, the formula ( The ratio of the structural unit in which Ar ¹ in 1) is a divalent aromatic group represented by formula (4) is preferably 70 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 90 to 100 mol%. %, and in the total structural unit represented by Formula (1), Ar ¹ may be a divalent aromatic group represented by Formula (4).

As a preferable example of the divalent aromatic group represented by Formula (4), Formula (4a) in which the bond in Formula (4) is mutually located at a para position:

[Formula 13]

[In formula (4a), R ³ to ^{R 6} each independently represent a hydrogen atom or a fluoroalkyl group having 1 to 12 carbon atoms, provided ^{that at least one of R 3} to ^{R 6} is fluoro having 1 to 12 carbon atoms represents an alkyl group, k represents an integer of 1 to 4, * represents a bond]

and an aromatic group represented by . From the viewpoint that the elastic modulus of the optical film is easily increased and the humidity expansion coefficient is easily reduced, when k in the formula (4a) is 1, ^{at least one of R 3} to ^{R 6} represents a fluoroalkyl group having 1 to 12 carbon atoms, R at least two of the ³ ~R ^6, and more preferably represents a fluoroalkyl group having 1 to 12 carbon atoms, and at least R ³ and R ⁵ are preferable, and R ³ and R ⁵ represents than a fluoroalkyl group having 1 to 12 carbon atoms represents a fluoroalkyl group having 1 to 12 carbon atoms, the R ⁴ and R ⁶ is more preferably represents a hydrogen atom. From the viewpoint that the elastic modulus of the optical film is easily increased and the humidity expansion coefficient is easily reduced, when k in the formula (4a) is 2, the group on the first benzene ring is R ^{3 to R 6} , and the group on the second benzene ring is R ^{When referring to 3} ' to R ^6' , it ^{is preferable that at least two of R 3 to R 6} and R ^{3' to R 6'} represent a fluoroalkyl group having 1 to 12 carbon atoms, and in a single bond bonding two benzene rings, ^{It is more preferable that at least R 4} and R ^6' present at a nearby position represent a fluoroalkyl group having 1 to 12 carbon atoms, R ⁴ and R ^6' represent a fluoroalkyl group having 1 to 12 carbon atoms, and R ³ , R It is more preferred that ⁵ , R ⁶ and R ^{3′ to R 5′ represent a hydrogen atom.} As the fluoroalkyl group having 1 to 12 carbon atoms, the above description regarding the fluoroalkyl group having 1 to 12 carbon atoms in ^{Ar 1 is similar, and preferred descriptions are also applicable.} From a viewpoint that k in Formula (4a) is easy to raise the elasticity modulus of an optical film and is easy to reduce a humidity expansion coefficient, Preferably it is an integer of 1 or 2. From a viewpoint that k in Formula (4a) is easy to raise the pencil hardness of an optical film, Preferably it is an integer of 2-4, More preferably, it is 2 or 3, More preferably, it is 2.

X in structural unit (1) and structural unit (2) represents a divalent organic group, Preferably it is a C4-C40 divalent organic group, More preferably, it is a C4-C40 divalent organic group which has a cyclic structure. represents the group. Examples of the cyclic structure include an alicyclic ring, an aromatic ring, and a heterocyclic structure. In the organic group, a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group, and in that case, the hydrocarbon group and the fluorine-substituted hydrocarbon group preferably have 1 to 8 carbon atoms. In one embodiment of the present invention, the structural units (1) and (2) contained in the polyamideimide-based resin may contain one type of organic group or two or more types of organic groups as X.

In one preferred aspect of the present invention, the structural unit represented by Formula (1) and the structural unit represented by Formula (2) are easy to increase the elastic modulus of the optical film and easily reduce the humidity expansion coefficient, as X , Equation (5):

[Formula 14]

[In formula (5),

Ar ² represents a divalent aromatic group which may have a substituent,

V is a single bond, -O-, a diphenylmethylene group, a fluorenyl group, a divalent hydrocarbon group having 1 to 12 carbon atoms, -SO ₂ -, -S-, -CO-, -PO-, -PO ₂ -, represents -N(R ^a )- or -Si(R ^b ) ₂ -, wherein the hydrocarbon group may include an alicyclic structure, and the hydrogen atoms contained in the hydrocarbon group are each independently selected from the halogen atom. may be substituted with, and R ^a and R ^b each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom,

m represents an integer of 0 to 3,

* indicates a bonding hand]

and a divalent organic group represented by When structural unit (1) and structural unit (2) contain the divalent organic group represented by Formula (5) as X, structural unit (1) and structural unit (2) are X, Formula (5) One type or two or more types of divalent organic groups represented by may be included. Structural unit (1) and structural unit (2) include, as X, other divalent organic groups other than the divalent organic group represented by formula (5) that do not correspond to the divalent organic group represented by formula (5). you may be doing

^{Ar 2} in Formula (5) represents the divalent aromatic group which may have a substituent. The divalent aromatic group is a group in which two hydrogen atoms of a monocyclic aromatic ring, a condensed polycyclic aromatic ring, or a ring set aromatic ring are substituted with a bond, and a monocyclic aromatic ring, a condensed polycyclic aromatic ring or a ring set for ^{Ar 1} Examples and preferred descriptions regarding the aromatic ring apply similarly to the monocyclic aromatic ring, the condensed polycyclic aromatic ring, or the ring-set aromatic ring for ^{Ar 2 .} When m in Formula (5) is 1 or more ^{, two or more Ar<2>} may mutually be same or different.

The divalent aromatic group which may have a substituent is preferably a group in which two hydrogen atoms of the aromatic hydrocarbon ring which may have a substituent are substituted with a bond from the viewpoint of increasing the elastic modulus of the optical film and easily reducing the humidity expansion coefficient. , more preferably a group in which two hydrogen atoms of benzene, biphenyl, terphenyl or quaterphenyl which may have a substituent are substituted with a bond, more preferably two groups of benzene or biphenyl which may have a substituent A group in which a hydrogen atom is substituted with a bond.

Examples of the substituent for Ar ² include a halogen group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, or a group in which a hydrogen atom contained therein is substituted with a halogen atom. can

The C1-C12 alkyl group may be a C1-C12 linear or branched alkyl group, Preferably it is a C1-C6 linear or branched alkyl group. Examples of such groups 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- and a methylbutyl group, 2-ethyl-propyl group, n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group and n-decyl group.

Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, and a cyclohexyloxy group. time, and the like.

Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a biphenyl group.

A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as a halogen atom.

The substituent for Ar ² is preferably a halogen group or an alkyl group having 1 to 12 carbon atoms in which a hydrogen atom may be substituted with a halogen atom, more preferably a methyl group, a fluoro group, a chloro group or a trifluoromethyl group. .

V in formula (5) is a single bond, -O-, a diphenylmethylene group, a fluorenyl group, a divalent hydrocarbon group having 1 to 12 carbon atoms, -SO ₂ -, -S-, -CO-, -PO-, -PO ₂ -, -N(R ^a )- or -Si(R ^b ) ₂ -. Here, the hydrocarbon group may contain an alicyclic structure, the hydrogen atoms contained in the hydrocarbon group may be each independently substituted with a halogen atom, and R ^a and R ^b are each independently a hydrogen atom. , or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and 2-methyl group. -Butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group, n-decyl group, etc. are mentioned. and these may be substituted with a halogen atom. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as said halogen atom. V in formula (5) is preferably a single bond, -O- or -S-, more preferably a single bond, from the viewpoint of being easy to improve the elastic modulus and bending resistance of the optical film and to reduce the humidity expansion coefficient. or -O-, more preferably a single bond.

m in Formula (5) represents the integer of 0-3, it is easy to raise the elasticity modulus of an optical film, From a viewpoint of being easy to reduce a humidity expansion coefficient, Preferably it is 0-2, More preferably, 0 or 1 is more preferable. it is 1.

A preferable aspect of the present invention in which the structural unit (1) and the structural unit (2) contained in the polyamideimide-based resin contained in the optical film of the present invention contains a divalent organic group represented by the formula (5) as X as X In the aspect, when the total of the structural unit (1) and the structural unit (2) contained in the polyamideimide-based resin is 100 mol% from the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient, , The ratio of the sum of the structural units in which X in Formula (1) is a divalent organic group represented by Formula (5) and a structural unit in which X in Formula (2) is a divalent organic group represented by Formula (5) is preferably is 70 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 90 to 100 mol%, and in the total structural units of the structural units (1) and (2), X is The divalent organic group represented by 5) may be sufficient.

In one preferred aspect of the present invention, the structural unit represented by Formula (1) and the structural unit represented by Formula (2) are easy to increase the elastic modulus of the optical film and easily reduce the humidity expansion coefficient, as X , Equation (5a):

[Formula 15]

[In formula (5a),

R ² represents a fluoroalkyl group having 1 to 12 carbon atoms,

p and q each independently represent an integer of 1 to 4, provided that, when p and/or q represents an integer of 2 to 4, ^{two or} more R 2 may be the same as or different from each other,

* indicates a bonding hand]

and a divalent organic group represented by In addition, the group divalent organic group represented by the formula (5a), a group that contains an organic group divalent group represented by the formula (5), specifically, the formula (5) in V represents a single bond, Ar ² carbon atoms represents a benzene ring substituted by an alkyl group (R ²⁾ a fluoroalkyl of 1 to 12, m is a group that is an organic group corresponds to a divalent represents an integer of 0 to 3. When structural unit (1) and structural unit (2) contain the divalent organic group represented by Formula (5a) as X, structural unit (1) and structural unit (2) are X, Formula (5a) One type or two or more types of divalent organic groups represented by may be included. Structural unit (1) and structural unit (2) include, as X, other divalent organic groups other than the divalent organic group represented by formula (5a) that do not correspond to the divalent organic group represented by formula (5a). you may be doing

^{R 2} in the formula (5a) represents a fluoroalkyl group having 1 to 12 carbon atoms, and as the group, the above description regarding the fluoroalkyl group having 1 to 12 carbon atoms in ^{Ar 1 is similar, and a preferred description is also} likewise fit

p and q each independently represent the integer of 1-4. From the viewpoint of the elastic modulus of the optical film and the coefficient of humidity expansion, p is preferably an integer of 1 or 2, more preferably 2. From a viewpoint of the elasticity modulus of an optical film, and a humidity expansion coefficient, q becomes like this. Preferably it is an integer of 1 or 2, More preferably, it is 1. Here, p and / or, if q represents an integer from 2 to 4, plural R ² are present, may be the same or different from each other, which, for a plurality existence R ² are preferably equal to each other.

With respect to the two bonding hands in the formula (5a), the position of each other is not particularly limited, and any of the ortho position, meta position, and para position may be used. Preferably they are positioned para to each other.

As a preferable example of the divalent aromatic group represented by Formula (5a), R<^2> in Formula (5a) represents a C1-C12 perfluoroalkyl group, p is 2, q is 1 or 2, and/ Alternatively, an aromatic group in which two bonding hands are located at a para position to each other may be mentioned.

A preferable aspect of the present invention in which the structural unit (1) and the structural unit (2) contained in the polyamideimide-based resin contained in the optical film of the present invention contains, as X, a divalent organic group represented by the formula (5a). In the aspect, when the total of the structural unit (1) and the structural unit (2) contained in the polyamideimide-based resin is 100 mol% from the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient, , The ratio of the sum of the structural units in which X in Formula (1) is a divalent organic group represented by Formula (5a) and the structural units in which X in Formula (2) is a divalent organic group represented by Formula (5a) is preferably is 70 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 90 to 100 mol%, and in the total structural units of the structural units (1) and (2), X is The divalent organic group represented by 5a) may be sufficient.

In one preferred aspect of the present invention, the structural unit represented by Formula (1) and the structural unit represented by Formula (2) are easy to increase the elastic modulus of the optical film and easily reduce the humidity expansion coefficient, as X , Equation (5b):

[Formula 16]

[In formula (5b), R ⁷ to ^{R 14} each independently represent a hydrogen atom or a fluoroalkyl group having 1 to 12 carbon atoms, provided ^{that at least one group of R 7} to ^{R 14} is a fluoroalkyl group having 1 to 12 carbon atoms represents an alkyl group, * represents a bond]

and a divalent aromatic group represented by In addition, the divalent aromatic group represented by Formula (5b) is a group corresponding to the aromatic group whose bond in Formula (5a) is mutually located in a para position, and p is 2. From the viewpoint of easy to increase the elastic modulus of the optical film and easy to reduce the humidity expansion coefficient, in formula (5b), ^{it is preferable that at least two of R 7} to ^{R 14} represent a fluoroalkyl group having 1 to 12 carbon atoms, and at least R ⁸ and R ¹⁴ more preferably represents a fluoroalkyl group having 1 to 12 carbon atoms, R ⁸ and R ¹⁴ represent a fluoroalkyl group having 1 to 12 carbon atoms, and R ⁷ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ more preferably represents a hydrogen atom. Further, in the above aspect, the fluoroalkyl group having 1 to 12 carbon atoms is preferably a perfluoroalkyl group having 1 to 12 carbon atoms, more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, further preferably a perfluoroalkyl group having 1 to 6 carbon atoms. A perfluoroalkyl group of -4, still more preferably a trifluoromethyl group or a pentafluoroethyl group, particularly preferably a trifluoromethyl group.

A preferable aspect of the present invention in which the structural unit (1) and the structural unit (2) contained in the polyamideimide-based resin contained in the optical film of the present invention contains, as X, a divalent organic group represented by the formula (5b). In the aspect, when the total of the structural unit (1) and the structural unit (2) contained in the polyamideimide-based resin is 100 mol% from the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient, , The ratio of the sum of the structural units in which X in the formula (1) is a divalent organic group represented by the formula (5b) and the structural units in which X in the formula (2) is a divalent organic group represented by the formula (5b) is preferably is 70 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 90 to 100 mol%, and in the total structural units of the structural units (1) and (2), X is The divalent organic group represented by 5b) may be sufficient.

In one preferred aspect of the present invention, the structural unit represented by Formula (1) is, from the viewpoint of easily increasing the elastic modulus of the optical film and easily reducing the humidity expansion coefficient, as X, Formula (5c):

[Formula 17]

[* in formula (5c) represents a bond]

and a divalent organic group represented by In the divalent organic group represented by the formula (5c), R ⁹ and R ¹¹ in the formula (5b) represent a trifluoromethyl group, and R ⁷ , R ⁸ , R ¹⁰ , R ¹² , R ¹³ and R ¹⁴ are It is a group corresponding to the divalent aromatic group which represents a hydrogen atom. When structural unit (1) and structural unit (2) contain the divalent organic group represented by Formula (5c) as X, structural unit (1) and structural unit (2) are X, Formula (5c) In addition to the divalent organic group represented by , other divalent organic groups not corresponding to the divalent organic group represented by the formula (5c) may be included.

A preferred aspect of the present invention in which the structural unit (1) and the structural unit (2) contained in the polyamideimide-based resin contained in the optical film of the present invention contains, as X, a divalent organic group represented by the formula (5c). In the aspect, when the total of the structural unit (1) and the structural unit (2) contained in the polyamideimide-based resin is 100 mol% from the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient, , The ratio of the sum of the structural units in which X in the formula (1) is a divalent organic group represented by the formula (5c) and the structural units in which X in the formula (2) is a divalent organic group represented by the formula (5c) is preferably is 70 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 90 to 100 mol%, and in the total structural units of the structural unit (1) and the structural unit (2), X is the formula The divalent organic group represented by (5c) may be sufficient.

Y in the structural unit represented by Formula (2) represents a tetravalent organic group, Preferably it represents a C4-C40 tetravalent organic group, More preferably, it represents a C4-C40 tetravalent organic group which has a cyclic structure. indicates. Examples of the cyclic structure include an alicyclic ring, an aromatic ring, and a heterocyclic structure. The organic group is an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group, and in that case, the hydrocarbon group and the fluorine-substituted hydrocarbon group preferably have 1 to 8 carbon atoms. In one Embodiment of this invention, structural unit (2) may have one type of tetravalent organic group as Y, and may have two or more types of tetravalent organic groups. As Y, Formula (20), Formula (21), Formula (22), Formula (23), Formula (24), Formula (25), Formula (26), Formula (27), Formula (28), Formula (29) a group represented by ); a group in which a hydrogen atom in the groups represented by the formulas (20) to (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and a tetravalent chain hydrocarbon group having 6 or less carbon atoms.

[Formula 18]

In formulas (20) to (29),

* represents a bond,

W ¹ is 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 ³ -O-Ar ³ -, -Ar ³ -CH ₂ -Ar ³ -, -Ar ³ -C(CH ₃ ) ₂ -Ar ³ - or -Ar ³ -SO ₂ -Ar ³ -. Ar ³ 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. When two or more Ar ³ exist, Ar ³ may be the same as or different from each other.

Among the groups represented by formulas (20) to (29), groups represented by formulas (26), (28) or (29) are preferable from the viewpoint of the elastic modulus, surface hardness and bending resistance of the optical film, The group represented by Formula (26) is more preferable. In addition, W ¹ is, independently of each other, a single bond, -O-, - CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH _{3 )} -, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ - is preferably a single bond, -O-, - It is more preferably CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -, a single bond, -C(CH ₃ ) ₂ - or -C( CF ₃ ) ₂ - is more preferred.

In one preferred embodiment of the present invention, the structural unit represented by the formula (2) is Y, and the formula (6):

[Formula 19]

[In formula (6), R ¹⁸ to ^{R 25} each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and R ¹⁸ to ^{R 25} The hydrogen atoms contained in may be each independently substituted by a halogen atom,

* indicates a bonding hand]

and a tetravalent organic group represented by When the structural unit (2) contains the tetravalent organic group represented by Formula (6) as Y, it is easy to raise the elasticity modulus of an optical film, and it is easy to reduce a humidity expansion coefficient. Moreover, in this case, the solubility to the solvent of polyamideimide-type resin is improved, it is easy to reduce the viscosity of the varnish containing the said resin, and it is easy to improve the workability of an optical film. Moreover, it is easy to improve the optical characteristic of an optical film.

In formula (6), R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. an alkoxy group or an aryl group having 6 to 12 carbon atoms. Alkyl group having 1 to 6 carbon atoms, an alkoxy group of 6 to 12 carbon atoms and having 1 to 6 carbon atoms and the aryl group, the formula (5) or an alkoxy group having a carbon number of the alkyl group, having 1 to 6 carbon atoms having 1 to 12 carbon atoms in the Ar ² of Examples of the 6-12 aryl group include those exemplified above. R ¹⁸ to ^{R 25} each independently 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, wherein R ¹⁸ to ^{R 25} The hydrogen atoms contained in may be each independently substituted by a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R ¹⁸ to ^{R 25} are, independently of each other, from the viewpoint of easily increasing the elastic modulus of the optical film, easily reducing the humidity expansion coefficient, and easily improving surface hardness, bending resistance and transparency, more preferably a hydrogen atom; a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, more preferably R ¹⁸ , R ¹⁹ , R ²⁰ , R ²³ , R ²⁴ and R ²⁵ are hydrogen atoms, R ²¹ and R ²² are hydrogen atoms; a methyl group, a fluoro group, a chloro group, or a trifluoromethyl group, particularly preferably R ²¹ and R ²² are a methyl group or a trifluoromethyl group.

In one preferred aspect of the present invention, the structural unit (2) contained in the polyamideimide-based resin contained in the optical film of the present invention contains, as Y, a tetravalent organic group represented by the formula (6), the optical film From the viewpoint of easily increasing the modulus of elasticity and easiness of reducing the coefficient of humidity expansion, when the total of the structural units (2) contained in the polyamideimide-based resin is 100 mol%, Y in the formula (2) is the formula (6) The proportion of the structural unit which is a tetravalent organic group represented by is preferably 70 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 90 to 100 mol%, and Structural unit WHEREIN: Y may be a tetravalent organic group represented by Formula (6).

In one preferred embodiment of the present invention, the structural unit represented by the formula (2) is Y, and the formula (6a):

[Formula 20]

and a tetravalent organic group represented by In the tetravalent organic group represented by the formula (6a), R ²¹ and R ²² in the formula (6) are trifluoromethyl groups, and R ¹⁸ , R ¹⁹ , R ²⁰ , R ²³ , R ²⁴ and R ²⁵ are hydrogen It corresponds to the group of atoms. When the structural unit (2) contains the tetravalent organic group represented by Formula (6a) as Y, it is easy to raise the elasticity modulus of an optical film, and it is easy to reduce a humidity expansion coefficient. Moreover, in this case, the solubility to the solvent of polyamideimide-type resin is improved, it is easy to reduce the viscosity of the varnish containing the said resin, and it is easy to improve the workability of an optical film. Moreover, it is easy to improve the optical characteristic of an optical film.

In one preferred aspect of the present invention, the structural unit (2) contained in the polyamideimide-based resin contained in the optical film of the present invention contains, as Y, a tetravalent organic group represented by the formula (6a), the optical film From the viewpoint of easily increasing the elastic modulus and reducing the humidity expansion coefficient, when the total of the structural units (2) contained in the polyamideimide-based resin is 100 mol%, Y in the formula (2) is the formula (6a) The proportion of the structural unit which is a tetravalent organic group represented by is preferably 70 to 100 mol%, more preferably 80 to 100 mol%, still more preferably 90 to 100 mol%, and In the structural unit, Y may be a tetravalent organic group represented by the formula (6a).

The polyamideimide-based resin contained in the optical film of the present invention has, in addition to the structural unit (1) and the structural unit (2), formula (3):

[Formula 21]

[Z in the formula (3) is a divalent organic group that does not correspond to a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms, and X' represents a divalent organic group]

It may contain the structural unit represented by When polyamideimide-type resin contains the structural unit represented by Formula (3) other than structural unit (1) and structural unit (2), it is easy to improve the pencil hardness of an optical film.

Z in the formula (3) is not particularly limited as long as it is a divalent organic group that does not correspond to a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms, for example, a hydrocarbon group having 1 to 8 carbon atoms or a fluorine-substituted A divalent organic group having 4 to 40 carbon atoms including a cyclic structure (preferably an alicyclic structure, an aromatic ring structure, or a heterocyclic structure) which may be substituted with a hydrocarbon group having 1 to 8 carbon atoms, the number of carbon atoms described for ^{Ar 1} The group which does not correspond to the divalent aromatic group which has the fluoroalkyl group of 1-12 is mentioned. As a C4-C40 divalent organic group containing a cyclic structure, Formula (20), Formula (21), Formula (22), Formula (23), Formula (24), Formula (25), Formula ( 26), a group in which two non-adjacent bonds of the groups represented by the formulas (27), (28) and (29) are substituted with hydrogen atoms, and groups having a thiophene ring structure are exemplified. .

Also, among these groups,

^{Among the bonds of the group represented by Formula (26) wherein W 1} is a single bond, or Formula (26') described later, which is substituted with a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms, two non-adjacent ones are substituted with hydrogen atoms energy,

Among the bonds of the groups represented by formulas (28) and (29) or the formulas (28') and (29') described later, which are substituted with a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms, 2 not adjacent a group in which a is replaced by a hydrogen atom, and

Since the group having a thiophene ring structure substituted with a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms corresponds to the divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms described for ^{Ar 1 , Formula (3)} It does not correspond to Z in

As Z in Formula (3), as a C4-C40 divalent organic group containing a cyclic structure, Formula (20'), Formula (21'), Formula (22'), Formula (23'), Formula ( 24'), Equation (25'), Equation (26'), Equation (27'), Equation (28') and Equation (29'):

[Formula 22]

[In formulas (20') to (29'), W ¹ and * are as defined in formulas (20) to (29)]

The divalent organic group represented by is more preferable.

In addition to the structural unit represented by Formula (1), polyamideimide-type resin has a structure in which Z in Formula (3) is represented by any one of said Formula (20') - Formula (29') When it has a unit, especially when Z in Formula (3) has a structural unit represented by Formula (7) mentioned later, in addition to the said structural unit, the following Formula (d1):

[Formula 23]

[In formula (d1), R ^e represents, independently of each other, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and R ^f is R ^e or -C (=O)-*, * represents a bond]

It is preferable from a viewpoint that it is easy to improve the film-forming property of a varnish, and it is easy to obtain the uniformity of an optical film to further have the structural unit derived from the carboxylic acid represented by.

In R ^e , the C 1 to C 6 alkyl group, the C 1 to C 6 alkoxy group, and the C 6 to C 12 aryl group are, respectively, the C 1 to C 12 alkyl group ^{in R 1} and R ^{2 in the formula (1).} , an alkoxy group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms may be exemplified above. Specifically, as the structural unit (d1) ^{, a structural unit in which both R e} and R ^f are hydrogen atoms (a structural unit derived from a dicarboxylic acid compound), R ^e is both a hydrogen atom, and R ^f is -C (= The structural unit (structural unit derived from a tricarboxylic acid compound) etc. which represent O)-* are mentioned.

The structural unit represented by Formula (3) is Z, and Formula (7a):

[Formula 24]

[In formula (7a), R ^g and R ^h each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, A, s and * is the same as A, s, and * in formula (7), t and u are each independently an integer of 0 to 4, provided that s is an integer of 1 to 4, and when A is not a single bond , R ^g and R ^h may each independently be substituted with a halogen atom]

It is preferable to include a divalent organic group represented by the formula (7):

[Formula 25]

[In formula (7), R ³¹ to ^{R 38} each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms;

A is, independently of each other, a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO- or -N(R ³⁹ )-, R ³⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom ,

s is an integer from 0 to 4,

* represents a bond,

However, when s is an integer of 1 to 4 and A is not a single bond, ^{the hydrogen atoms included in R 31} to ^{R 38} may be independently substituted with a halogen atom]

It is more preferable to include a divalent organic group represented by .

In the formula (7a), the bonding hand of each benzene ring may be bonded to any of the ortho position, the meta position, or the para position on the basis of -A-, Preferably it may be bonded to the meta position or the para position. . ^{R g} and R ^h in the formula (7a) each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. It is preferable that t and u in the formula (7a) are 0, but when t and/or u are 1 or more, R ^g and R ^h preferably represent an alkyl group having 1 to 6 carbon atoms, more preferably 1 carbon atom to 3 alkyl groups. ^{In R g} and R ^h in Formula (7a), as a halogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, and a C6-C12 aryl group, respectively, the halogen in Formula (7) What was illustrated as an atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, or a C6-C12 aryl group is mentioned.

t and u in formula (7a) are mutually independently an integer of 0-4, Preferably it is an integer of 0-2, More preferably, it is 0 or 1, More preferably, it is 0.

In formulas (7) and (7a), A is a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ - , -C(CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO- or -N(R ³⁹ )-, from the viewpoint of bending resistance of the optical film, preferably -O- or - S- is represented, More preferably, -O- is represented.

In formula (7), R ³¹ , R ³² , R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ and R ³⁸ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. of an alkoxy group or an aryl group having 6 to 12 carbon atoms. An alkyl group having 1 to 12 carbon atoms, an alkoxy group of 6 to 12 carbon atoms and having 1 to 6 carbon atoms and the aryl group, the formula (5) or an alkoxy group having a carbon number of the alkyl group, having 1 to 6 carbon atoms having 1 to 12 carbon atoms in the Ar ² of Examples of the 6-12 aryl group include those exemplified above. From the viewpoint of surface hardness and flexibility of the optical film, R ³¹ to ^{R 38} are each independently, preferably 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 , and more preferably a hydrogen atom. Here, when s is an integer of 1 to 4 and A is not a single bond, ^{the hydrogen atoms included in R 31} to ^{R 38} may be each independently substituted with a halogen atom.

R ³⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and 2-methyl group. -Butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group, n-decyl group, etc. are mentioned. and these may be substituted with a halogen atom. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as said halogen atom. Polyamideimide-based resin WHEREIN: The structural unit represented by Formula (3) may contain one type of divalent organic group represented by Formula (7) or Formula (7a) as Z, Formula (7) Or two or more types of organic groups represented by Formula (7a) may be included.

In Formulas (7) and (7a), s is an integer in the range of 0-4, and when s is in this range, the bending resistance and elastic modulus of an optical film will become favorable easily. Moreover, in Formula (7) and Formula (7a), s becomes like this. Preferably it is an integer in the range of 0-3, More preferably, it is 0-2, More preferably, it is 0 or 1, Especially preferably, it is 0. When s is in this range, it will be easy to improve the bending resistance and elastic modulus of an optical film. As X' in Formula (7), the group described above with respect to X in structural unit (1) and structural unit (2) is mentioned.

In the polyamideimide-type resin contained in the optical film of this invention, the structural unit represented by Formula (3) is Z, Formula (3'):

[Formula 26]

You may have a structural unit represented by In this case, it is easy to improve the surface hardness and bending resistance of an optical film, and it is easy to reduce YI value.

The polyamideimide-type resin contained in the optical film of this invention is a structural unit represented by Formula (3) other than structural unit (1) and structural unit (2) (hereinafter, also referred to as "structural unit (3)" ), the structural unit (1), the structural unit (2) and the structural unit (3) contained in the polyamideimide-based resin from the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient. Assuming that the total of the structural units (1) and (2) is 100 mol%, the ratio of the total of the structural units (1) and (2) is preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more. % or more, even more preferably 85 mol% or more, particularly preferably 90 mol% or more. The upper limit of the said ratio of the total of a structural unit (1) and a structural unit (2) should just be less than 100 mol%. In addition, content of structural unit (1), structural unit (2), or structural unit (3) ^{can be measured using 1} H-NMR, for example, or can also be computed from the introduction ratio of a raw material.

The polyamideimide-type resin contained in the optical film of this invention is a structural unit represented by Formula (3) other than structural unit (1) and structural unit (2) (hereinafter, also referred to as "structural unit (3)" ), the total of the structural units (1) and (3) contained in the polyamideimide-based resin from the viewpoint of easily increasing the elastic modulus of the optical film and reducing the humidity expansion coefficient is 100 mol% , the proportion of the structural unit (1) is preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, and particularly preferably 90 mol% or more. The upper limit of the said ratio of structural unit (1) should just be less than 100 mol%. Content of structural unit (1), structural unit (2), or structural unit (3) ^{can be measured using 1} H-NMR, for example, or can also be computed from the introduction ratio of a raw material.

Polyamideimide-type resin may contain the structural unit represented by Formula (30) and/or the structural unit represented by Formula (31) other than the structural unit represented by Formula (1) and Formula (2).

[Formula 27]

In Formula (30), Y<^1> is a tetravalent organic group, Preferably it is an organic group in which the hydrogen atom in the organic group may be substituted by the hydrocarbon group or the hydrocarbon group by which the fluorine substitution was carried out. As Y<^1> , the group described as Y in Formula (2) is mentioned. In one embodiment of the present invention, the polyamide-imide-based resin, it may comprise a plurality of types of Y ^1, Y ¹ of a plurality of species may be the same or different from each other.

In the formula (31), Y ² is a trivalent organic group, preferably an organic group which may be substituted by a hydrogen atom of a hydrocarbon group or a fluorine-substituted hydrocarbon group in the organic group. Examples of Y ² include a group in which any one of the bonds of the group described as Y in the formula (2) is substituted with a hydrogen atom, and a trivalent chain hydrocarbon group having 6 or less carbon atoms. In one embodiment of the present invention, the polyamide-imide-based resin may include a plurality of types of Y ^2, Y ² is a plurality of types may be the same or different from each other.

In Formulas (30) and (31), X ¹ and X ² are each independently a divalent organic group, and preferably a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. it is organic As X<^1> and X<^2> , the group described as X in Formulas (1) and (2) is illustrated.

In one embodiment of the present invention, the polyamideimide-based resin comprises a structural unit represented by Formula (1), a structural unit represented by Formula (2), and, optionally, a structural unit represented by Formula (3). , a structural unit represented by Formula (30), and/or a structural unit represented by Formula (31). From the viewpoint of easy to increase the elastic modulus of the optical film, easy to reduce the humidity expansion coefficient, and easy to improve optical properties, surface hardness and bending resistance, in the polyamideimide-based resin, the formulas (1) and (2) are The structural unit represented is preferably 80 mol% based on the total structural units represented by the formulas (1) and (2), and optionally by the formulas (3), (30) and (31). or more, more preferably 90 mol% or more, still more preferably 95 mol% or more. In addition, in the polyamideimide-based resin, the structural units represented by formulas (1) and (2) include formulas (1) and (2), and optionally formulas (3), (30) and / Or based on the total structural unit represented by Formula (31), it is 100 % or less normally. In addition, the said ratio ^{can be measured using 1} H-NMR, for example, or can also be computed from the introduction ratio of a raw material.

In one embodiment of the present invention, the content of the polyamideimide-based resin in the optical film is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and still more preferably 10 parts by mass or more with respect to 100 parts by mass of the optical film. Preferably it is 50 mass parts or more, Preferably it is 99.5 mass parts or less, More preferably, it is 95 mass parts or less. When content of polyamideimide-type resin is in the said range, it is easy to raise the optical characteristic and elastic modulus of an optical film, and it is easy to reduce a humidity expansion coefficient.

The weight average molecular weight (Mw) of the polyamideimide-based resin is 200,000 to 1,000,000 in terms of standard polystyrene. When the weight average molecular weight (Mw) of the polyamideimide-based resin is less than 200,000, the elastic modulus of the optical film cannot be sufficiently increased and the humidity expansion coefficient cannot be sufficiently reduced. Moreover, when the weight average molecular weight (Mw) of polyamideimide-type resin exceeds 1,000,000, the solubility to the solvent of polyamide-imide-type resin falls, and it becomes difficult to process an optical film. The weight average molecular weight (Mw) of the polyamideimide-based resin, in terms of standard polystyrene, is preferably is 220,000 or more, more preferably 250,000 or more, still more preferably 270,000 or more, particularly preferably 300,000 or more. In addition, from the viewpoint of easily improving the solubility of the polyamideimide-based resin in a solvent and improving the stretchability and workability of the optical film, the weight average molecular weight of the resin is preferably 900,000 or less, more preferably preferably 800,000 or less, more preferably 700,000 or less, particularly preferably 600,000 or less. A weight average molecular weight can perform GPC measurement, can calculate|require by standard polystyrene conversion, for example, and may compute it by the method as described in an Example, for example.

The elastic modulus of the optical film of the present invention is preferably 4 GPa or more, more preferably 4.5 GPa or more, still more preferably 4.8 GPa or more from the viewpoint of being easy to prevent wrinkles and scratches of the optical film. Although the upper limit of an elasticity modulus is not specifically limited, Usually, it is 100 GPa or less. In addition, the elastic modulus can be measured using a tensile tester (50 mm distance between chuck|zippers, 10 mm/min at a tensile speed), for example, can be measured by the method as described in an Example.

The coefficient of humidity expansion (CME) of the optical film of the present invention is preferably 23 from the viewpoint of easily suppressing the expansion and contraction of the optical film in the planar direction when the temperature and humidity are changed in a state in which a load is applied to the optical film. It is ppm or less, More preferably, it is 22 ppm or less, More preferably, it is 21 ppm or less, Especially preferably, it is 20 ppm or less. The smaller the coefficient of humidity expansion, the easier it is to suppress the expansion and contraction of the optical film in the plane direction when the temperature and humidity are changed in a state where the load is applied to the optical film, and the lower limit thereof is not particularly limited, and if it is 0 ppm or more do. In addition, CME may be the humidity expansion coefficient of a film when it is controlled to 60 degreeC, 90% R.H., and hold|maintained for 1 hour, for example, it can measure by the method as described in an Example.

The total light transmittance of the optical film of the present invention and/or the light transmittance with respect to light of 300 to 800 nm is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more, Especially preferably, it is 91% or more. When a total light transmittance is more than the said lower limit, when an optical film is assembled to a display apparatus especially as a front plate, it will be easy to improve visibility. Since the optical film of the present invention usually exhibits a high total light transmittance, for example, compared with the case where a film having a low transmittance is used, it becomes possible to suppress the light emission intensity of a display element etc. necessary for obtaining a constant brightness. For this reason, power consumption can be reduced. For example, when the optical film of the present invention is incorporated into a display device, bright display tends to be obtained even if the amount of light of the backlight is reduced, which can contribute to energy saving. The upper limit of the total light transmittance is usually 100% or less. In addition, a total light transmittance can be measured using a haze computer based on JISK7361-1:1997, for example. The total light transmittance may be the total light transmittance in the range of the thickness of the optical film mentioned later.

The haze of the optical film of the present invention is preferably 5% or less, more preferably 4% or less, still more preferably 3% or less, still more preferably 2.5% or less, particularly preferably 2% or less, particularly More preferably, it is 1 % or less, Especially more preferably, it is 0.5 % or less, Especially preferably, it is 0.2 % or less, Usually, it is 0.01 % or more. When the haze of an optical film is below the said upper limit and it assembles|assembles an optical film to a display apparatus especially as a front plate, it will be easy to improve visibility. In addition, a haze can be measured using a haze computer based on JISK7136:2000.

YI value of the optical film of this invention becomes like this. Preferably it is 3.5 or less, More preferably, it is 3.0 or less, More preferably, it is 2.5 or less. Transparency becomes favorable as YI value of an optical film is below the said upper limit, and when it uses for the front plate of a display device, it can contribute to high visibility. Moreover, YI value is -5 or more normally, Preferably it is -2 or more. In addition, the YI value is measured for transmittance with respect to light of 300 to 800 nm using an ultraviolet visible near infrared spectrophotometer to obtain tristimulus values (X, Y, Z), and YI = 100 × (1.2769X-1.0592Z) )/Y can be calculated based on the formula. In addition, in this specification, that an optical film is excellent in an optical characteristic means that light transmittance is high.

The thickness of the optical film of the present invention is preferably 10 µm or more, more preferably 20 µm or more, still more preferably 25 µm or more, particularly preferably 30 µm or more, preferably 200 µm or less, more preferably Preferably it is 100 micrometers or less, More preferably, it is 80 micrometers or less, Especially preferably, it is 60 micrometers or less, A combination of these upper and lower limits may be sufficient. When the thickness of an optical film exists in said range, it will be easy to raise the elasticity modulus of an optical film more. In addition, the thickness of an optical film can be measured using a micrometer, for example, can be measured by the method as described in an Example.

In the optical film of the present invention, the number of bending times (bending radius R = 1 mm) in the bending resistance test is preferably 150,000 times or more, more preferably 180,000 times or more, still more preferably 200,000 times or more. . It has bending resistance sufficient as a front-plate material, such as a flexible display device, as the number of times of bending is more than the said lower limit. In addition, the number of times of bending in the bending resistance test uses a bending tester, and the bending radius (radius of curvature) R performs repeated bending of the optical film under the conditions of 1 mm, and a crack occurs in the said film The number of bending rounds up to the starting point is indicated (one round trip is one time).

The pencil hardness of at least one surface of the optical film of this invention becomes like this. Preferably it is H or more, More preferably, it is 2H or more. When the pencil hardness of the at least one surface of an optical film is more than said hardness, it is easy to prevent the flaw etc. in the said surface of an optical film. In addition, pencil hardness can be measured based on JISK5600-5-4:1999, for example, can be measured by the method as described in an Example.

In addition to the optical film containing the polyamideimide-based resin, the present invention also provides the aforementioned polyamideimide-based resin suitable for producing the optical film. Such polyamideimide-based resin is, for example, Formula (1):

[Formula 28]

[In formula (1),

Ar ¹ represents a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms,

X represents a divalent organic group]

^{, and as Ar 1} in Formula (1), Formula (4):

[Formula 29]

[in formula (4),

R ¹ represents a fluoroalkyl group having 1 to 12 carbon atoms,

n and k independently represent an integer of 1 to 4, provided that when n and/or k represent an integer of 2 to 4, a plurality of R ¹ may be the same or different from each other,

* indicates a bond]

A structural unit containing a divalent aromatic group represented by, and Formula (2):

[Formula 30]

[In formula (2), X represents a divalent organic group, Y represents a tetravalent organic group]

It may be a polyamideimide-based resin having at least a structural unit represented by , and having a weight average molecular weight of 200,000 to 1,000,000. Regarding examples and preferred aspects of the type of each symbol and the ratio of structural units in the polyamideimide-based resin, the above description regarding the polyamideimide-based resin contained in the optical film of the present invention is similarly applicable.

The content of halogen atoms in the polyamideimide-based resin is preferably 1 to 60% by mass, more preferably 5 to 55% by mass, still more preferably 10 based on the mass of the polyamideimide-based resin. -50 mass %. It is easy to raise the elasticity modulus of an optical film as content of a halogen atom is more than said lower limit, and it is easy to reduce a humidity expansion coefficient, and it is easy to improve transparency and visibility more easily. If content of a halogen atom is below the said upper limit, it will become easy to synthesize|combine resin.

The imidation ratio of the polyamideimide-based resin is preferably 90% or more, more preferably 93% or more, and still more preferably 96% or more. From a viewpoint of being easy to improve the optical characteristic of an optical film, it is preferable that imidation ratio is more than said lower limit. Moreover, the upper limit of the imidation ratio is 100 % or less. The imidation ratio represents the ratio of the molar amount of imide bonds in the polyamideimide-based resin to a value twice the molar amount of the structural unit derived from the tetracarboxylic acid compound in the polyamideimide-based resin. In addition, when the polyamideimide-based resin contains a tricarboxylic acid compound, a value twice the molar amount of the structural unit derived from the tetracarboxylic acid compound in the polyamideimide-based resin and the composition derived from the tricarboxylic acid compound The ratio of the molar amount of the imide bond in the polyamideimide-based resin to the sum of the molar amount of the unit is shown. In addition, the imidation rate can be calculated|required by IR method, NMR method, etc.

< Manufacturing method of resin >

The polyamideimide-based resin having at least the predetermined structural unit (1) and the structural unit (2) contained in the optical film of the present invention and having a weight average molecular weight of 200,000 to 1,000,000 is, for example, tetracarboxylic acid. It can manufacture using a compound, a dicarboxylic acid compound, and a diamine compound as main raw materials. Here, the structural unit represented by said Formula (1) is a structural unit formed by a dicarboxylic acid compound and a diamine compound react, and the structural unit represented by said Formula (2) is a tetracarboxylic acid compound and It is a structural unit formed by the reaction of a diamine compound. Therefore, you may manufacture polyamideimide-type resin using the same dicarboxylic acid compound, a tetracarboxylic acid compound, and a diamine compound used as the structural unit represented by said Formula (1) and Formula (2). It is preferable that a dicarboxylic acid compound contains the compound represented by Formula (8) at least from this viewpoint.

[Formula 31]

[In formula (8), Ar ¹ is as defined for ^{Ar 1} in formula (1) ^{, and R c} and R ^d are, independently of each other, a hydroxyl group, a methoxy group, an ethoxy group, and an n-propoxy group , an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group or a chlorine atom.]

In one preferred embodiment of the present invention, the dicarboxylic acid compound is a compound represented by formula (8) in which ^{R c} and R ^{d are chlorine atoms.} Moreover, you may use a diisocyanate compound instead of a diamine compound.

The dicarboxylic acid compound used in the production of the resin is preferably an aromatic dicarboxylic acid having a fluoroalkyl group or an acid chloride compound thereof, such as terephthalic acid having a fluoroalkyl group, 4,4'-oxybisbenzoic acid or their Acid chloride compounds are used. In addition to terephthalic acid, 4,4'-oxybisbenzoic acid, or their acid chloride compounds, other dicarboxylic acid compounds may be used. Examples of other dicarboxylic acid compounds include aromatic dicarboxylic acid, aliphatic dicarboxylic acid, and their derivative acid chloride compounds, acid anhydrides, and the like, and may be used in combination of two or more. Specific examples include an aromatic dicarboxylic acid compound having a trifluoromethyl group (isophthalic acid; naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid), and trifluoro and a compound in which two benzoic acids having a romethyl group are linked by a single bond or a phenylene group, and their acid chloride compounds. As specific examples, 2,2'-bis(trifluoromethyl)-4,4'-biphenyldicarboxylic acid chloride and 2,5-bis(trifluoromethyl)terephthaloyl chloride are preferable.

As a dicarboxylic acid compound, you may use the compound represented by Formula (8), and another dicarboxylic acid compound. As another dicarboxylic acid compound, Formula (7')

[Formula 32]

[In formula (7'), R ³¹ to ^{R 38} independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and R ³¹ to The ^{hydrogen atoms contained in R 38} may be each independently substituted with a halogen atom,

A is a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO _{2 represents} -, -S-, -CO- or -N(R ³⁹ )-;

R ³⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom,

s is an integer from 0 to 4,

R ^c and R ^d are as defined for ^{R c} and R ^d in formula (8)]

The dicarboxylic acid compound represented by is mentioned.

In one Embodiment of this invention, the compound represented by Formula (7') in which s is 1-4 and A is an oxygen atom may be sufficient as another dicarboxylic acid compound.

As a diamine compound used for manufacture of resin, an aliphatic diamine, an aromatic diamine, and these mixtures are mentioned, for example. In addition, in this embodiment, "aromatic diamine" represents the diamine in which the amino group couple|bonded directly with the aromatic ring, and may contain the aliphatic group or another substituent in a part of the structure. This aromatic ring may be a monocyclic ring or a condensed ring may be sufficient as it, Although a benzene ring, a naphthalene ring, an anthracene ring, a fluorene ring, etc. are illustrated, It is not limited to these. Among these, a benzene ring is preferable. Moreover, "aliphatic diamine" represents the diamine in which the amino group couple|bonded directly with the aliphatic group, and may contain the aromatic ring and another substituent in a part of the structure.

Examples of the aliphatic diamine include acyclic aliphatic diamines such as hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, norbornanediamine and 4; Cyclic aliphatic diamines, such as 4'- diamino dicyclohexyl methane, etc. are mentioned. These can be used individually or in combination of 2 or more types.

Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2, Aromatic diamines having one aromatic ring, such as 6-diaminonaphthalene, 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'-dia minodiphenylsulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[ 4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane , 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl (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- and aromatic diamines having two or more aromatic rings, such as chlorophenyl) fluorene and 9,9-bis (4-amino-3-fluorophenyl) fluorene. These can be used individually or in combination of 2 or more types.

Aromatic diamine is preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylether, 3,3'-diaminodiphenylether , 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl] Sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy) ) Phenyl] propane, 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB), 4,4'-bis (4-aminophenoxy) c) biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diamino Diphenylsulfone, 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) ratio It is phenyl. These can be used individually or in combination of 2 or more types.

Among the diamine compounds, it is preferable to use at least one selected from the group consisting of aromatic diamines having a biphenyl structure from the viewpoint of high surface hardness, high transparency, high flexibility, high bending resistance, and low coloration of the optical film. 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 at least one selected from the group consisting of 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl (TFMB).

As a tetracarboxylic-acid compound used for manufacture of resin, Aromatic tetracarboxylic-acid compounds, such as aromatic tetracarboxylic dianhydride; and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydride. A tetracarboxylic-acid compound may be used independently and may be used in combination of 2 or more type. The tetracarboxylic acid compound may be a tetracarboxylic acid compound analog other than a dianhydride, 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 tetracarboxylic dianhydride. Examples of the non-condensed polycyclic aromatic tetracarboxylic dianhydride include 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic 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-dicarboxyphenyl) Propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (sometimes described as 6FDA) , 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,2-bis(3,4-dicarboxyphenyl) ) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride , 4,4'-(p-phenylenedioxy)diphthalic dianhydride and 4,4'-(m-phenylenedioxy)diphthalic dianhydride. Examples of the monocyclic aromatic tetracarboxylic dianhydride include 1,2,4,5-benzenetetracarboxylic dianhydride, and examples of the condensed polycyclic aromatic tetracarboxylic dianhydride include 2,3,6,7-naphthalenetetracarboxylic dianhydride is mentioned.

Among these, preferably 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and 2,2',3,3'-benzophenonetetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-di Phenylsulfonetetracarboxylic 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)ethane Dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-di) Carboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylenedioxy)diphthalic dianhydride water and 4,4'-(m-phenylenedioxy)diphthalic dianhydride, more preferably 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-biphenyl Tetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), bis(3,4) -dicarboxyphenyl)methane dianhydride and 4,4'-(p-phenylenedioxy)diphthalic acid dianhydride are mentioned. These can be used individually or in combination of 2 or more types.

Examples of the aliphatic tetracarboxylic dianhydride include cyclic or acyclic aliphatic tetracarboxylic dianhydride. Cyclic aliphatic tetracarboxylic dianhydride is tetracarboxylic dianhydride having an alicyclic hydrocarbon structure, and specific examples thereof include 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclo Cycloalkanetetracarboxylic dianhydride such as butanetetracarboxylic dianhydride and 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 regioisomers thereof. These can be used individually or in combination of 2 or more types. Specific examples of the acyclic aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and 1,2,3,4-pentanetetracarboxylic dianhydride. It can be used in combination of 2 or more types. Moreover, you may use combining cyclic aliphatic tetracarboxylic dianhydride and acyclic aliphatic tetracarboxylic dianhydride.

Among the tetracarboxylic dianhydrides, 4,4'-oxydiphthalic dianhydride, 3,3',4, 4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3 ',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride Water, and mixtures thereof, are preferred, 3,3',4,4'-biphenyltetracarboxylic dianhydride and 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride, and mixtures thereof This is more preferable, and 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA) is more preferable.

In addition, the polyamideimide-based resin is obtained by further reacting tetracarboxylic acid and tricarboxylic acid and their anhydrides and derivatives in addition to the tetracarboxylic acid compound within a range that does not impair the various physical properties of the optical laminate. okay

As tetracarboxylic acid, the water adduct of the anhydride of the said tetracarboxylic acid compound is mentioned.

As a tricarboxylic acid compound, an aromatic tricarboxylic acid, an aliphatic tricarboxylic acid, and those analogous acid chloride compounds, an acid anhydride, etc. are mentioned, You may use in combination of 2 or more type. Specific examples include anhydride of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalenetricarboxylic acid-2,3-anhydride; and compounds in which phthalic anhydride and benzoic acid are linked by a single bond, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, or a phenylene group. .

Production of resin WHEREIN: The usage-amount of a diamine compound, a tetracarboxylic acid compound, and/or a dicarboxylic acid compound can be suitably selected according to the ratio of each structural unit of a desired polyamideimide-type resin.

The method for producing a polyamideimide-based resin having at least the structural unit (1) and the structural unit (2) and having a weight average molecular weight of 200,000 to 1,000,000 is not particularly limited as long as the polyamideimide-based resin is obtained. However, from the viewpoint of easy to increase the elastic modulus of the optical film and easy to reduce the humidity expansion coefficient, as a manufacturing method in which a diamine compound, a tetracarboxylic acid compound, and a dicarboxylic acid compound are reacted, a manufacturing method in which a dicarboxylic acid compound is dividedly added Thus, it is preferable to produce a polyamideimide-based resin, and a step (I) of reacting a diamine compound and a tetracarboxylic acid compound to produce an intermediate (A), and a step (I) of the intermediate (A) and a dicarboxylic acid compound (preferably Preferably, it includes the step (II) of reacting the compound represented by the formula (8)), wherein in the step (II), the polyamideimide-based resin is produced by a method in which the dicarboxylic acid compound is added in portions. more preferably.

In the polyamideimide-based resin contained in the optical film of the present invention, Ar ¹ in the formula (1) is a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms. It is thought that a specific part will have a moderate degree of rigidity and intermolecular repulsion force. When a polyamideimide-based resin having such a structure is produced without using a method of adding a dicarboxylic acid compound in portions, it becomes difficult to set the weight average molecular weight of the polyamideimide-based resin within the desired range. there was Moreover, although the reason is not clear by manufacturing using the method of adding a dicarboxylic acid compound by division, it is thought that resin optimal for raising the elastic modulus of an optical film and reducing a humidity expansion coefficient is obtained.

Accordingly, the polyamideimide-based resin contained in the optical film of the present invention and the polyamideimide-based resin of the present invention are a manufacturing method in which a diamine compound, a tetracarboxylic acid compound, and a dicarboxylic acid compound are reacted with dicarboxylic acid. It is preferable that it is a resin manufactured by the manufacturing method of adding a compound by division, and the process (I) of reacting a diamine compound and a tetracarboxylic acid compound to produce|generate intermediate (A), and the said intermediate (A) and dicarboxylic acid A production method comprising a step (II) of reacting a compound (preferably a compound represented by formula (8)), in the step (II), a production method in which the dicarboxylic acid compound is added in portions It is more preferable that it is made resin. A production method comprising the step of dividingly adding a dicarboxylic acid compound to a polyamideimide-based resin having at least the structural unit (1) and the structural unit (2) and having a weight average molecular weight of 200,000 to 1,000,000 In the case of manufacturing, it is easy to adjust the weight average molecular weight of the polyamideimide-based resin within the above range.

In the case of producing the polyamideimide-based resin by the production method including the above steps (I) and (II), the step (I) of reacting a diamine compound and a tetracarboxylic acid compound to produce an intermediate (A) Although the reaction temperature is not specifically limited, For example, 5-200 degreeC, Preferably it is 5-100 degreeC, More preferably, it is 5-50 degreeC, More preferably, it may be 5 degreeC - room temperature (about 25 degreeC). The reaction time may be, for example, 1 minute to 72 hours, preferably 10 minutes to 24 hours. Moreover, the reaction may be performed while stirring in air or in an inert gas atmosphere (eg nitrogen, argon, etc.), and may be performed under normal pressure, under pressure, or under reduced pressure. In a preferred embodiment, stirring is carried out under normal pressure and/or in an inert gas atmosphere.

In process (I), a diamine compound and a tetracarboxylic-acid compound react, and an intermediate body (A), ie, a polyamic acid, is produced|generated. Therefore, the intermediate body (A) has at least a structural unit derived from a diamine compound and a structural unit derived from a tetracarboxylic acid compound.

Next, in a process (II), it is preferable to make an intermediate body (A) and a dicarboxylic acid compound react, and to add the said dicarboxylic acid compound separately here. The dicarboxylic acid compound is dividedly added to the reaction solution obtained in the step (I), and the intermediate (A) and the dicarboxylic acid compound are reacted. It is easy to raise the molecular weight of a polyamideimide-type resin by adding a dicarboxylic acid compound in divisions, rather than adding it all at once. In addition, in this specification, divided addition means adding the dicarboxylic acid compound to be added in several times dividedly, more specifically, dividing the dicarboxylic acid to be added into a specific amount, and adding each at predetermined intervals (predetermined time). means to do Since the predetermined interval (predetermined time) includes even a very short interval (or time), the divided addition includes continuous addition (or continuous feed).

Step (II) WHEREIN: The number of division|segmentation at the time of adding a dicarboxylic acid compound by division can be suitably selected according to reaction scale, the kind of raw material, etc., Preferably it is 2-20 times, More preferably, it is 3-10 times. , more preferably 3 to 6 times. When the number of divisions is within the above range, it is easy to increase the molecular weight of the polyamideimide-based resin.

A dicarboxylic acid compound may be divided|segmented and added by the equal quantity, and may be divided|segmented and added by the non-uniform quantity. The time between each addition (hereinafter sometimes referred to as an addition interval) may be the same or different. In addition, when adding two or more types of dicarboxylic acid compounds, the term "partial addition" means adding the total amount of all dicarboxylic acid compounds in divisions, and the method of dividing each dicarboxylic acid compound is not particularly limited. However, for example, each dicarboxylic acid compound may be separately added collectively or dividedly, each dicarboxylic acid compound may be dividedly added together, and these combinations may be sufficient.

In step (II), when the weight average molecular weight of the polyamide-based resin reaches preferably 10% or more, more preferably 15% or more with respect to the weight average molecular weight of the obtained polyamide-based resin, the addition is performed It is preferable to add the dicarboxylic acid compound in an amount of preferably 1 to 40 mol%, more preferably 2 to 25 mol%, based on the total molar amount of the dicarboxylic acid compound.

Although the reaction temperature of step (II) is not specifically limited, For example, 5-200 degreeC, Preferably 5-100 degreeC, More preferably, 5-50 degreeC, More preferably, 5 degreeC - room temperature (25 degreeC) degree) may be sufficient. In addition, the reaction may be performed while stirring in air or in an atmosphere of an inert gas such as nitrogen or argon, or may be performed under normal pressure, under pressure, or under reduced pressure. In a preferred embodiment, the step (II) is performed under normal pressure and/or in an inert gas atmosphere while stirring.

Step (II) WHEREIN: A polyamideimide precursor is obtained by carrying out stirring etc. and reacting a dicarboxylic acid compound by division|segmentation addition for predetermined time. In addition, the polyamideimide precursor can be isolated, for example, by adding a large amount of water to a reaction solution containing the polyamideimide precursor, precipitating the polyamideimide precursor, and performing filtration, concentration, drying, etc. have.

In the step (II), the intermediate (A) and the dicarboxylic acid compound react to obtain a polyamideimide precursor. Therefore, the polyamideimide precursor is polyamideimide before imidization (before ring closure) having at least a structural unit derived from a diamine compound, a structural unit derived from tetracarboxylic acid, and a structural unit derived from a dicarboxylic acid compound. indicates

In manufacture of resin, although the reaction temperature of a diamine compound, a tetracarboxylic acid compound, and a dicarboxylic acid compound is not specifically limited, For example, 5-350 degreeC, Preferably it is 5-200 degreeC, More preferably, 5- It is 100°C. Although reaction time is not specifically limited, either, For example, it is about 30 minutes - about 10 hours. If necessary, the reaction may be performed under an inert atmosphere or under reduced pressure. In a preferred embodiment, the reaction is carried out under normal pressure and/or in an inert gas atmosphere while stirring. Moreover, it is preferable to perform reaction in the solvent inactive to reaction. The solvent is not particularly limited as long as it does not affect the reaction, and for example, water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy- alcohol solvents such as 2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, γ-valerolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; alicyclic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as N,N-dimethylacetamide and N,N-dimethylformamide; sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane; carbonate solvents such as ethylene carbonate and propylene carbonate; and combinations thereof (mixed solvents). Among these, an amide type solvent can be used suitably from a solubility viewpoint.

The manufacturing method of polyamideimide-type resin may further include the process (III) of imidating a polyamideimide precursor in presence of an imidation catalyst. By providing the polyamideimide precursor obtained in the step (II) to the step (III), among the structural units of the polyamideimide precursor, a portion of the structural unit having a polyamic acid structure is imidized (ring closure), and the formula (1) is Polyamideimide-type resin containing the structural unit represented by the structural unit and the structural unit represented by Formula (2) can be obtained. Examples of the imidization catalyst include aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; alicyclic amines (monocyclic) such as N-ethylpiperidine, N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroazepine; alicyclic amines (polycyclic) such as azabicyclo[2.2.1]heptane, azabicyclo[3.2.1]octane, azabicyclo[2.2.2]octane, and azabicyclo[3.2.2]nonane; and pyridine, 2-methylpyridine (2-picoline), 3-methylpyridine (3-picoline), 4-methylpyridine (4-picoline), 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine and aromatic amines such as , 2,4-dimethylpyridine, 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and isoquinoline. . Moreover, it is preferable to use an acid anhydride with an imidation catalyst from a viewpoint of being easy to accelerate|stimulate imidation reaction. Examples of the acid anhydride include a common acid anhydride used in the imidation reaction, and specific examples thereof include aliphatic acid anhydrides such as acetic anhydride, propionic acid anhydride and butyric acid anhydride, and aromatic acid anhydrides such as phthalic acid.

The polyamideimide-based resin is isolated (separated and purified) by a separation means such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, etc. Alternatively, in a preferred embodiment, a large amount of alcohol such as methanol is added to a reaction solution containing a polyamideimide-based resin, the resin is precipitated, and the reaction solution can be isolated by concentration, filtration, drying, and the like.

< Filler >

The optical film of this invention may also contain at least 1 sort(s) of filler. As a filler, an organic particle, an inorganic particle, etc. are mentioned, for example, Preferably an inorganic particle is mentioned. Examples of the inorganic particles include particles of metal oxides such as silica, zirconia, alumina, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide and cerium oxide, and metal fluoride such as magnesium fluoride and sodium fluoride. Particles etc. are mentioned, Among these, from a viewpoint of increasing the elasticity modulus and/or tearing strength of an optical film, and being easy to improve impact resistance, Preferably, a silica particle, a zirconia particle, an alumina particle is mentioned, , more preferably silica particles. These fillers can be used individually or in combination of 2 or more types.

The filler, preferably the silica particle, has an average primary particle diameter of 1 nm or more, more preferably 5 nm or more, still more preferably 10 nm or more, even more preferably 15 nm or more, particularly preferably 20 nm or more. or more, preferably 100 nm or less, more preferably 90 nm or less, still more preferably 80 nm or less, still more preferably 70 nm or less, particularly preferably 60 nm or less, particularly more preferably 50 nm or less. Hereinafter, more preferably, it is 40 nm or less. When the average primary particle diameter of a silica particle is in the said range, aggregation of a silica particle is suppressed and it is easy to improve the optical characteristic of the optical film obtained. The average primary particle diameter of a filler can be measured by BET method. In addition, you may measure an average primary particle diameter by image analysis with a transmission electron microscope or a scanning electron microscope.

When the optical film of the present invention contains a filler, preferably silica particles, the content of the filler is usually 0.1 parts by mass or more, preferably 1 part by mass or more, more preferably 5 parts by mass with respect to 100 parts by mass of the optical film. It is mass part or more, More preferably, it is 10 mass parts or more, More preferably, it is 20 mass parts or more, Especially preferably, it is 30 mass parts or more, Preferably it is 60 mass parts or less. It will be easy to improve the elasticity modulus of the optical film obtained as content of a filler is more than the said minimum. Moreover, it will be easy to improve the optical characteristic of an optical film as content of a filler is below the said upper limit.

< UV absorber >

The optical film of this invention may also contain at least 1 sort(s) of ultraviolet absorber. The ultraviolet absorber can be appropriately selected from those commonly used as ultraviolet absorbers in the field of resin materials. The ultraviolet absorber may contain a compound that absorbs light having a wavelength of 400 nm or less. Examples of the ultraviolet absorber include at least one compound selected from the group consisting of a benzophenone-based compound, a salicylate-based compound, a benzotriazole-based compound, and a triazine-based compound. The ultraviolet absorber may be used alone or in combination of two or more. Since deterioration of resin is suppressed when an optical film contains a ultraviolet absorber, when the optical film of this invention is applied to a display apparatus etc., visibility can be improved. In this specification, a "system compound" refers to the derivative of the compound to which the said "system compound" is attached. For example, a "benzophenone-based compound" refers to a compound having a benzophenone as a parent skeleton and a substituent bonded to the benzophenone.

When the optical film of the present invention contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.01 to 10 parts by mass, more preferably 1 to 8 parts by mass relative to the mass of the polyamideimide-based resin contained in the optical film. It is a mass part, More preferably, it is 2-7 mass parts. When content of a ultraviolet absorber is more than the said lower limit, it will be easy to improve ultraviolet absorbency. When the content of the ultraviolet absorber is equal to or less than the above upper limit, decomposition of the ultraviolet absorber due to heat during substrate production can be suppressed, and optical properties can be easily improved, for example, haze can be easily reduced.

< Other additives >

The optical film of this invention may contain other additives other than a filler and a ultraviolet absorber further. As another additive, antioxidant, mold release agent, stabilizer, coloring agents, such as a bluing agent, a flame retardant, a pH adjuster, a silica dispersing agent, a lubricant, a thickener, a leveling agent, etc. are mentioned, for example. When containing other additives, the content may be preferably 0.001 to 20 mass%, more preferably 0.01 to 15 mass%, still more preferably 0.1 to 10 mass% with respect to the mass of the optical film.

(Manufacturing method of optical film)

Although the manufacturing method of the optical film of this invention is not specifically limited, For example, the following process:

(a) a step of preparing a polyamideimide-based resin composition containing at least the polyamideimide-based resin and a solvent (hereinafter also referred to as “varnish”) (varnish preparation step);

(b) applying the varnish to the support material to form a coating film (application step), and

(c) The process of drying the applied liquid (coating film) and forming an optical film (optical film formation process)

A manufacturing method comprising

In the varnish preparation step, the polyamideimide-based resin is dissolved in a solvent, and if necessary, additives such as the filler and the ultraviolet absorber are added and mixed with stirring to prepare a varnish. In addition, when silica particles are used as fillers, a silica sol in which the dispersion of silica sol containing silica particles is substituted with a solvent in which the resin is soluble, for example, a solvent used for preparation of the following varnish is added to the resin. You can do it.

The solvent used for preparation of a varnish will not be specifically limited if the said resin can be melt|dissolved. 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 dimethyl sulfone, dimethyl sulfoxide, and sulfolane; carbonate solvents such as ethylene carbonate and propylene carbonate; and combinations thereof (mixed solvents). Among these, an amide-based solvent or a lactone-based solvent is preferable. These solvents can be used individually or in combination of 2 or more types. Moreover, water, an alcohol solvent, a ketone solvent, an acyclic ester solvent, an ether solvent, etc. may be contained in a varnish. The solid content concentration of the varnish is preferably 1 to 25 mass%, more preferably 5 to 20 mass%, still more preferably 5 to 15 mass%.

A coating process WHEREIN: A varnish is apply|coated on a support material by a well-known coating method, and a coating film is formed. As a well-known coating method, For example, the roll coating method, such as wire bar coating method, reverse coating, gravure coating, the die coating method, the comma coating method, the lip coating method, the spin coating method, the screen coating method, the fountain coating method, the D. The ping method, the spray method, the casting method, etc. are mentioned.

A film formation process WHEREIN: An optical film can be formed by drying a coating film and peeling from a support material. You may provide the process of further drying an optical film after peeling. Drying of a coating film can be performed at the temperature of 50-350 degreeC normally. If necessary, the coating film may be dried under an inert atmosphere or under reduced pressure.

Examples of the support material include a SUS plate if it is a metal type, a PET film, a PEN film, a polyamide type resin film, a polyimide type resin film, a cycloolefin type polymer (COP) film, an acrylic type film if it is a resin type. Especially, from a viewpoint of being excellent in smoothness and heat resistance, PET film, a COP film, etc. are preferable, Furthermore, from a viewpoint of adhesiveness with an optical film, and a viewpoint of cost, PET film is more preferable.

(functional layer)

One or more functional layers may be laminated|stacked on at least one surface of the optical film of this invention. As a functional layer, an ultraviolet-ray absorption layer, a hard-coat layer, a primer layer, a gas barrier layer, an adhesion layer, a color adjustment layer, a refractive index adjustment layer, etc. are mentioned, for example. A functional layer can be used individually or in combination of 2 or more types.

The ultraviolet absorbing layer is a layer having a function of absorbing ultraviolet rays, and includes, for example, a main material selected from an ultraviolet curable transparent resin, an electron beam curable transparent resin, and a thermosetting transparent resin, and ultraviolet rays dispersed in the main material. It consists of an absorbent.

(hard coating)

A hard-coat layer may be provided in at least one surface of the optical film of this invention. The thickness of a hard-coat layer is not specifically limited, For example, 2-100 micrometers may be sufficient. When the thickness of the hard coat layer is within the above range, sufficient scratch resistance can be ensured, and bending resistance is less likely to decrease, and the problem of curling due to curing shrinkage tends to be less likely to occur.

The hard coat layer can be formed by curing a hard coating composition containing a reactive material capable of forming a crosslinked structure by irradiation with active energy ray or applying heat energy, and it is preferable to apply active energy ray. Active energy rays are defined as energy rays that can generate active species by decomposing compounds that generate active species, and include visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays, and electron beams. and, preferably, ultraviolet rays. The said hard-coat composition contains the at least 1 sort(s) of polymer of a radically polymerizable compound and a cationically polymerizable compound.

The said radically polymerizable compound is a compound which has a radically polymerizable group. The radically polymerizable group of the radically polymerizable compound may be a functional group capable of causing a radical polymerization reaction, and includes a group containing a carbon-carbon unsaturated double bond, and specifically, a vinyl group and (meth)acryl group. Royl, etc. are mentioned. In addition, when the said radically polymerizable compound has two or more radically polymerizable groups, these radically polymerizable groups may mutually be same or different. The number of radically polymerizable groups which the said radically polymerizable compound has in 1 molecule is a point which improves the hardness of a hard-coat layer, Preferably it is 2 or more. As said radically polymerizable compound, from the point of reactivity height, Preferably the compound which has a (meth)acryloyl group is mentioned, Specifically, it has 2-6 pieces of (meth)acryloyl group in 1 molecule. A compound called a functional acrylate monomer or an oligomer having several (meth)acryloyl groups in the molecule called epoxy (meth)acrylate, urethane (meth)acrylate, and polyester (meth)acrylate with a molecular weight of hundreds to thousands and, preferably, at least one selected from epoxy (meth)acrylate, urethane (meth)acrylate, and polyester (meth)acrylate.

The said cationically polymerizable compound is a compound which has cationically polymerizable groups, such as an epoxy group, an oxetanyl group, and a vinyl ether group. From the point of improving the hardness of a hard-coat layer, the number of the cationically polymerizable groups which the said cationically polymerizable compound has in 1 molecule becomes like this. Preferably it is 2 or more, More preferably, it is 3 or more.

Moreover, as said cationically polymerizable compound, the compound which has at least 1 sort(s) of an epoxy group and oxetanyl group as a cationically polymerizable group is especially preferable. Cyclic ether groups, such as an epoxy group and an oxetanyl group, are preferable at the point which shrinkage|contraction accompanying a polymerization reaction is small. Moreover, the compound which has an epoxy group among cyclic ether groups has the advantage of being easy to obtain the compound of various structures, and it does not exert a bad influence on the durability of the obtained hard-coat layer, Compatibility with a radically polymerizable compound is also easy to control. In addition, the oxetanyl group among the cyclic ether groups tends to have a higher degree of polymerization compared with the epoxy group, speeds up the network formation rate obtained from the cationically polymerizable compound of the obtained hard coat layer, and also in the region where the radical polymerizable compound and the radically polymerizable compound are mixed. There are advantages such as forming an independent network without leaving a monomer in the film.

As the cationically polymerizable compound having an epoxy group, for example, a polyglycidyl ether of a polyhydric alcohol having an alicyclic ring, or a compound containing a cyclohexene ring or a cyclopentene ring is epoxyd with an appropriate oxidizing agent such as hydrogen peroxide or peracid. alicyclic epoxy resin obtained by making it; Aliphatic epoxy resins, such as polyglycidyl ether of an aliphatic polyhydric alcohol or its alkylene oxide adduct, polyglycidyl ester of an aliphatic long-chain polybasic acid, and a homopolymer and copolymer of glycidyl (meth)acrylate; Glycidyl ether produced by reaction of bisphenols such as bisphenol A, bisphenol F and hydrogenated bisphenol A, or derivatives such as alkylene oxide adducts and caprolactone adducts thereof with epichlorohydrin , and novolac epoxy resins, and glycidyl ether type epoxy resins derived from bisphenols.

The hard coating composition may further include a polymerization initiator. As a polymerization initiator, a radical polymerization initiator, a cationic polymerization initiator, a radical, a cationic polymerization initiator, etc. are mentioned, It selects suitably and is used. These polymerization initiators are decomposed|disassembled by at least 1 sort(s) of active energy ray irradiation and heating, generate|occur|produce a radical or a cation, and advance radical polymerization and cationic polymerization.

A radical polymerization initiator should just be able to release|release the substance which initiates radical polymerization by at least any of active energy ray irradiation and heating. For example, as a thermal radical polymerization initiator, organic peroxides, such as hydrogen peroxide and perbenzoic acid, Azo compounds, such as azobisbutyronitrile, etc. are mentioned.

As the active energy ray radical polymerization initiator, there are a Type 1 radical polymerization initiator that generates radicals by decomposition of molecules and a Type 2 radical polymerization initiator that coexists with tertiary amines and generates radicals by a hydrogen extraction type reaction. used as or in combination.

A cationic polymerization initiator should just be able to release the substance which starts cationic polymerization by at least any one of active energy ray irradiation and heating. As a cationic polymerization initiator, an aromatic iodonium salt, an aromatic sulfonium salt, a cyclopentadienyl iron(II) complex, etc. can be used. These can initiate cationic polymerization either or both of active energy ray irradiation or heating depending on the difference in structure.

The polymerization initiator may preferably include 0.1 to 10 mass% based on 100 mass% of the total hard coating composition. When the content of the polymerization initiator is within the above range, curing can be sufficiently progressed, mechanical properties and adhesion of the finally obtained coating film can be within a good range, and adhesion failure or cracking phenomenon and curl due to curing shrinkage The phenomenon tends to be difficult to occur.

The hard coating composition may further include one or more selected from the group consisting of solvents and additives.

The solvent is one capable of dissolving or dispersing the polymerizable compound and the polymerization initiator, and as long as it is a solvent known as a solvent for a hard coating composition in the art, it can be used within a range that does not impair the effects of the present invention.

The additive may further include inorganic particles, a leveling agent, a stabilizer, a surfactant, an antistatic agent, a lubricant, an antifouling agent, and the like.

The pressure-sensitive adhesive layer is a layer having an adhesive function, and has a function of bonding an optical film to another member. As a material for forming the pressure-sensitive adhesive layer, a commonly known material can be used. For example, a thermosetting resin composition or a photocurable resin composition can be used. In this case, the resin composition can be polymerized and cured by supplying energy afterwards.

The pressure-sensitive adhesive layer may be a layer that is adhered to the object by pressure, called a pressure sensitive adhesive (PSA). The pressure-sensitive adhesive may be a pressure-sensitive adhesive that is "a substance that has tackiness at room temperature and adheres to an adherend with light pressure" (JIS K6800), "a specific component is contained in a protective film (microcapsule), and suitable means A capsule adhesive which is an adhesive which can maintain stability until the film is destroyed by (pressure, heat, etc.)" (JIS K6800) may be sufficient.

A color adjustment layer is a layer which has a function of color adjustment, and is a layer which can adjust the laminated body containing an optical film to the target color. The color adjustment layer is a layer containing, for example, a resin and a colorant. Examples of the colorant include inorganic pigments such as titanium oxide, zinc oxide, bengala, titanium oxide calcined pigments, ultramarine blue, cobalt aluminate, and carbon black; organic pigments such as azo compounds, quinacridone compounds, anthraquinone compounds, perylene compounds, isoindolinone compounds, phthalocyanine compounds, quinophthalone compounds, srene compounds, and diketopyrrolopyrrole compounds; extender pigments such as barium sulfate and calcium carbonate; and dyes such as basic dyes, acid dyes, and mordant dyes.

The refractive index adjusting layer is a layer having a function of adjusting the refractive index, for example, having a refractive index different from that of the optical film, and is a layer capable of imparting a predetermined refractive index to the optical laminate. The refractive index adjusting layer may be, for example, an appropriately selected resin and a resin layer further containing a pigment as the case may be, or may be a thin metal film. As a pigment which adjusts a refractive index, a silicon oxide, aluminum oxide, antimony oxide, a tin oxide, a titanium oxide, a zirconium oxide, and a tantalum oxide are mentioned, for example. The average primary particle diameter of the pigment may be 0.1 µm or less. When the average primary particle diameter of the pigment is 0.1 µm or less, diffuse reflection of light passing 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 adjusting layer include metal oxides 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; and metal nitrides.

In one preferred embodiment of the present invention, the optical film of the present invention is useful as a front plate of a display device, particularly a front plate of a flexible display device (hereinafter sometimes referred to as a window film). A flexible display device has a flexible functional layer, and the optical film which overlaps with a flexible functional layer and functions as a front plate, for example. That is, the front plate of the flexible display device is disposed on the visual recognition side on the flexible functional layer. This front plate has a function of protecting a flexible functional layer.

As a display device, wearable devices, such as a television, a smart phone, a mobile phone, a car navigation system, a tablet PC, a portable game machine, electronic paper, an indicator, a bulletin board, a watch, and a smart watch, etc. are mentioned. As a flexible display device, all the display devices which have a flexible characteristic are mentioned.

[Flexible Display Device]

This invention also provides the flexible display apparatus provided with the optical film of this invention. The optical film of the present invention is preferably used as a front plate in a flexible display device, and the front plate is sometimes called a window film. A flexible display device consists of a laminated body for flexible display devices, and an organic electroluminescent display panel, with respect to the organic electroluminescent display panel, the flexible display laminated body is arrange|positioned on the visual recognition side, and it is comprised so that it can bend. The laminate for a flexible display device may contain a window film, a polarizing plate, and a touch sensor, and although the lamination order of them is arbitrary, it is laminated|stacked in the order of a window film, a polarizing plate, a touch sensor or a window film, a touch sensor, and a polarizing plate from the visual recognition side. It is preferable to be When a polarizing plate exists on the visual recognition side of a touch sensor, since it becomes difficult to visually recognize the pattern of a touch sensor, and the visibility of a display image improves, it is preferable. Each member may be laminated using an adhesive, an adhesive, or the like. In addition, a light-shielding pattern formed on at least one surface of any layer of the window film, the polarizing plate, and the touch sensor may be provided.

[Polarizer]

The flexible display device of the present invention may further include a polarizing plate, preferably a circularly polarizing plate. The circularly polarizing plate is a functional layer having a function of transmitting only a right circularly polarized light component or a left circularly polarized light component by laminating a λ/4 retardation plate on a linearly polarizing plate. For example, it is used to convert external light into right-circularly polarized light, block external light that is reflected by the organic EL panel and becomes left-circularly polarized light, and transmits only the luminescent component of organic EL to suppress the influence of reflected light and make the image easier to see. In order to achieve the circularly polarized light function, the absorption axis of the linear polarizing plate and the slow axis of the λ/4 retarder need to be 45° in theory, but 45±10° in practice. The linear polarizing plate and the λ/4 retardation plate do not necessarily need to be stacked adjacent to each other, and the relationship between the absorption axis and the slow axis may satisfy the above-mentioned range. Although it is desirable to achieve perfect circularly polarized light at all wavelengths, it is not necessary for practical use, so the circularly polarizing plate in the present invention also includes an elliptically polarizing plate. It is also preferable to further laminate a λ/4 retardation film on the viewing side of the linear polarizing plate and to make the emitted light circularly polarized to improve visibility in a state in which polarized sunglasses are worn.

The linear polarizing plate is a functional layer having a function of passing light vibrating in the transmission axis direction, but blocking polarization of a vibration component perpendicular to it. The linear polarizing plate may have a configuration provided with a linear polarizer alone or a linear polarizer and a protective film affixed on at least one surface thereof. The thickness of the said linear polarizing plate may be 200 micrometers or less, Preferably it is 0.5-100 micrometers. When the thickness is within the above range, the flexibility tends to be less likely to decrease.

The linear polarizer may be a film-type polarizer manufactured by dyeing and stretching a polyvinyl alcohol (PVA)-based film. When a dichroic dye such as iodine is adsorbed to a PVA-based film orientated by stretching or stretched in a state adsorbed to PVA, the dichroic dye orients and exhibits polarization performance. In manufacture of the said film polarizer, you may have other processes, such as swelling, bridge|crosslinking by a boric acid, washing|cleaning by aqueous solution, and drying. The stretching and dyeing steps may be performed alone with the PVA-based film, or may be performed in a laminated state with other films such as polyethylene terephthalate. The thickness of the PVA-based film used is preferably 10 to 100 m, and the draw ratio is preferably 2 to 10 times.

Moreover, as another example of the said polarizer, the liquid crystal application type polarizer formed by apply|coating a liquid crystal polarizing composition may be sufficient. The liquid crystal polarizing composition may include a liquid crystal compound and a dichroic dye compound. The said liquid crystalline compound should just have the property which shows a liquid crystal state, and since it can exhibit high polarization performance when it has high-order orientation states, such as a smectic phase, it is preferable. Moreover, it is also preferable that a liquid crystalline compound has a polymerizable functional group.

The said dichroic dye is a dye which orientates together with the said liquid crystal compound and shows dichroism, The dichroic dye itself may have liquid crystallinity, and may have a polymerizable functional group. Any compound in the liquid crystal polarizing composition has a polymerizable functional group.

The liquid crystal polarizing composition may further include 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 prepared by coating a liquid crystal polarizing composition on an alignment layer to form a liquid crystal polarizing layer.

A liquid crystal polarizing layer can be formed thinly compared with a film-type polarizer. The thickness of the liquid crystal polarizing layer may be preferably 0.5 to 10 µm, more preferably 1 to 5 µm.

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

As said protective film, what is necessary is just a transparent polymer film, The material and additive used for the said transparent base material can be used. A cellulosic film, an olefinic film, an acrylic film, and a polyester-type film are preferable. The protective film of the coating type obtained by apply|coating and hardening|curing cation hardening compositions, such as an epoxy resin, and radical hardening compositions, such as an acrylate, may be sufficient. If necessary, it may contain a plasticizer, an ultraviolet absorber, an infrared absorber, a colorant such as a pigment or dye, an optical brightener, a dispersant, a heat stabilizer, a light stabilizer, an antistatic agent, an antioxidant, a lubricant, a solvent, and the like. The thickness of the said protective film may be 200 micrometers or less, Preferably it is 1-100 micrometers. When the thickness of the said protective film exists in the said range, the softness|flexibility of a protective film is hard to fall. The protective film can also serve as a transparent base material for the window.

The λ/4 retardation plate is a film imparting a retardation of λ/4 in a direction orthogonal to the traveling direction of the incident light, that is, in the in-plane direction of the film. The λ/4 retardation plate may be a stretched retardation plate manufactured by stretching a polymer film such as a cellulose-based film, an olefin-based film, or a polycarbonate-based film. If necessary, phase difference regulator, plasticizer, ultraviolet absorber, infrared absorber, colorant such as pigment or dye, optical brightener, dispersant, heat stabilizer, light stabilizer, antistatic agent, antioxidant, lubricant, solvent, etc. may be included. The thickness of the stretched retardation plate may be 200 µm or less, and preferably 1 to 100 µm. When the thickness is within the above range, the flexibility of the film tends to be difficult to decrease.

Further, as another example of the λ/4 retardation plate, a liquid crystal coating type retardation plate formed by coating a liquid crystal composition may be used. The liquid crystal composition includes a liquid crystal compound having a property of exhibiting a liquid crystal state such as nematic, cholesteric, and smectic. Any compound including the liquid crystal compound in the liquid crystal composition has a polymerizable functional group. The liquid crystal coating type retardation plate may further include 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 manufactured by coating and curing a liquid crystal composition on an alignment film to form a liquid crystal retardation layer, similarly to the substrate in the liquid crystal polarizing layer. The liquid-crystal-coated retardation plate can be formed to have a thinner thickness than that of an elongated retardation plate. The thickness of the said liquid crystal polarizing layer is 0.5-10 micrometers normally, Preferably 1-5 micrometers may be sufficient. The liquid-crystal-coated retardation plate may be laminated by peeling off the substrate and transferring it, or the substrate may be laminated as it is. It is also preferable that the said base material plays a role as a transparent base material of a protective film, a retardation plate, and a window.

In general, there are many materials that exhibit greater birefringence for shorter wavelengths and smaller birefringence for longer wavelengths. In this case, since a phase difference of λ/4 cannot be achieved in the entire visible light region, the in-plane retardation is 100 to 180 nm, preferably 130 to 150 nm, which is the same as λ/4 in the vicinity of 560 nm with high visibility. They are often designed to be It is preferable to use a reverse dispersion λ/4 retarder using a material having a birefringence wavelength dispersion characteristic opposite to that of usual because visibility can be improved. As such a material, it is also preferable to use those described in Japanese Patent Application Laid-Open No. 2007-232873 or the like in the case of a stretched retardation plate, and in Japanese Patent Application Laid-Open No. 2010-30979 in the case of a liquid crystal coated retardation plate.

As another method, there is also known a technique for obtaining a broadband λ/4 retarder by combining it with a ?/2 retarder (Japanese Patent Laid-Open No. 10-90521). The λ/2 retardation plate is also manufactured by the same material method as the λ/4 retardation plate. The combination of the stretched retardation plate and the liquid crystal coating type retardation plate is arbitrary, but it is preferable to use either the liquid crystal coating type retardation plate because the thickness can be made thin.

A method of laminating a positive C plate on the circular polarizing plate in order to increase visibility in an oblique direction is also known (Japanese Patent Application Laid-Open No. 2014-224837). The positive C plate may also be a liquid-crystal-coated retardation plate or a stretched retardation plate. The retardation in the thickness direction is -200 to -20 nm, preferably -140 to -40 nm.

[Touch sensor]

The flexible display device of the present invention may further include a touch sensor. A touch sensor is used as an input means. As a touch sensor, various types, such as a resistive film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and a capacitive method, are proposed, and any method may be used. Among them, the electrostatic capacitive method is preferable. The capacitive touch sensor is divided into an active area and an inactive area located outside the active area. The active area is an area corresponding to a display area where a screen is displayed on the display panel, and is an area in which a user's touch is sensed, and the inactive area is an area corresponding to a non-display area in which a screen is not displayed on the display device. The touch sensor includes: a substrate having flexible characteristics; a sensing pattern formed in the active region of the substrate; Each sensing line is formed in the non-active area of the substrate and connected to an external driving circuit through the sensing pattern and the pad part. As the substrate having flexible properties, the same material as the transparent substrate for the window can be used. As for the board|substrate of a touch sensor, it is preferable from the point of crack suppression of a touch sensor that the toughness is 2,000 MPa% or more. More preferably, the toughness may be 2,000 to 30,000 MPa%. Here, the toughness is defined as the area under the curve from the stress-strain curve obtained through the tensile test of the polymer material to the fracture point.

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 on the same layer, and in order to sense a touched point, each pattern must be electrically connected. In the first pattern, each unit pattern is connected to each other through a seam, but in the second pattern, each unit pattern is separated from each other in an island form. I need this. As the sensing pattern, a known transparent electrode material may be applied. For example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), indium gallium zinc oxide (IGZO), cadmium tin oxide (CTO), PEDOT (poly (3,4-ethylenedioxythiophene)), carbon nanotubes (CNT), graphene, and metal wires, and these may be used alone or in combination of two or more. Preferably, ITO can be used. The metal used for a metal wire is not specifically limited, For example, silver, gold, aluminum, copper, iron, nickel, titanium, selenium, chromium, etc. are mentioned. These can be used individually or in mixture of 2 or more types.

The bridge electrode may be formed on the insulating layer by interposing an insulating layer on the sensing pattern, the bridge electrode may be formed on a 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, or may be formed of a metal such as molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or an alloy of two or more thereof. Since the first pattern and the second pattern must be electrically insulated, an insulating layer is formed between the sensing pattern and the bridge electrode. The insulating layer may be formed only between the seam of the first pattern and the bridge electrode, or may be formed in the structure of a layer covering the sensing pattern. In the latter case, the bridge electrode may connect the second pattern through a contact hole formed in the insulating layer. The touch sensor appropriately compensates for the difference in transmittance between the pattern region in which the pattern is formed and the non-pattern region in which the pattern is not formed, specifically, the difference in light transmittance caused by the difference in refractive index in these regions. An optical control layer may be further included between the substrate and the electrode as a means for this, and the optical control layer may include an inorganic insulating material or an organic insulating material. The optical control layer may be formed by coating a photocurable composition including a photocurable organic binder and a solvent on a substrate. The photocurable composition may further include inorganic particles. The refractive index of the optical control layer can be increased by the inorganic particles.

The photocurable organic binder may include, for example, a copolymer of each monomer such as an acrylate-based monomer, a styrene-based monomer, or a carboxylic acid-based monomer. The photocurable organic binder may be, for example, a copolymer containing different repeating units, such as an epoxy group-containing repeating unit, an acrylate repeating unit, and a carboxylic acid repeating unit.

The inorganic particles may include, for example, zirconia particles, titania particles, alumina particles, and the like. The photocurable composition may further include each additive such as a photopolymerization initiator, a polymerizable monomer, and a curing aid.

[Adhesive layer]

Each layer, such as a window film, a circular polarizing plate, and a touch sensor, which forms the laminate for a flexible display device, and a film member such as a linear polarizing plate and a λ/4 retardation plate constituting each layer can be adhered with an adhesive. . Examples of the adhesive include water-based adhesives, organic solvent-based adhesives, solvent-free adhesives, solid adhesives, solvent volatilization adhesives, water-based solvent volatilization adhesives, moisture curing adhesives, heat curing adhesives, anaerobic curing adhesives, active energy ray curing adhesives, curing agent mixed adhesives, A general-purpose adhesive, such as a heat-melting adhesive, a pressure-sensitive adhesive, a pressure-sensitive adhesive, and a remoistening adhesive, can be used. Among them, a water-based solvent volatilization type adhesive, an active energy ray-curable adhesive, and an adhesive are frequently used. The thickness of the adhesive layer can be appropriately adjusted according to the required adhesive force and the like, and is, for example, 0.01 to 500 µm, preferably 0.1 to 300 µm. Although two or more adhesive layers may exist in the said laminated body for flexible display devices, each thickness and the kind of adhesive agent used may be same or different.

As the water-based solvent volatilization type adhesive, a water-dispersed polymer such as a polyvinyl alcohol-based polymer and a water-soluble polymer such as starch, an ethylene-vinyl acetate emulsion, or a styrene-butadiene emulsion can be used as the main polymer. In addition to water and the main polymer, 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. When adhere|attaching with the said water-based solvent volatilization type adhesive agent, adhesiveness can be provided by pouring the said water-based solvent volatilization type adhesive agent between to-be-adhesive layers, and bonding to-be-adhered layers, by drying. The thickness of the adhesive layer in the case of using the said water-based solvent volatilization type|mold adhesive agent is 0.01-10 micrometers, Preferably 0.1-1 micrometer may be sufficient as it. When using the said water-system solvent volatilization type adhesive agent for formation of multiple layers, the thickness of each layer and the kind of the said adhesive agent may be same or different.

The said active energy ray hardening-type adhesive agent can be formed by hardening of the active energy ray hardening composition containing the reactive material which irradiates an active energy ray and forms an adhesive bond layer. The said active energy ray hardening composition can contain the at least 1 sort(s) of polymer of the radically polymerizable compound similar to a hard-coat composition, and a cationically polymerizable compound. The said radically polymerizable compound is the same as that of a hard-coat composition, The thing of the same kind as a hard-coat composition can be used. As a radically polymerizable compound used for a contact bonding layer, the compound which has an acryloyl group is preferable. It is also preferable to include a monofunctional compound in order to lower the viscosity as an adhesive composition.

The said cationically polymerizable compound is the same as a hard-coat composition, and can use the thing of the same kind as a hard-coat composition. As a cationically polymerizable compound used for an active energy ray hardening composition, an epoxy compound is more preferable. It is also preferable to include a monofunctional compound as a reactive diluent in order to lower the viscosity of the adhesive composition.

The active energy ray composition may further include a polymerization initiator. Examples of the polymerization initiator include a radical polymerization initiator, a cationic polymerization initiator, a radical and a cationic polymerization initiator, and the like, and can be appropriately selected and used. These polymerization initiators are decomposed|disassembled by at least 1 sort(s) of active energy ray irradiation and heating, generate|occur|produce a radical or a cation, and advance radical polymerization and cation polymerization. An initiator capable of initiating at least either radical polymerization or cationic polymerization by irradiation with an active energy ray in the substrate of the hard coating composition can be used.

The active energy ray curing composition may further include an ion scavenger, an antioxidant, a chain transfer agent, an adhesion imparting agent, a thermoplastic resin, a filler, a flow viscosity modifier, a plasticizer, an antifoaming agent, an additive, a solvent. In the case of bonding with the active energy ray-curable adhesive, the active energy ray-curable composition is applied to any or both of the adherend layers and then bonded, and passes through any adherend layer or both adherend layers and irradiated with active energy rays. It can be adhered by curing it. The thickness of the contact bonding layer in the case of using the said active energy ray hardening-type adhesive agent is 0.01-20 micrometers, Preferably 0.1-10 micrometers may be sufficient as it. When using the said active energy ray hardening-type adhesive agent for formation of multiple layers, the thickness of each layer and the kind of adhesive agent used may be same or different.

As said adhesive, it is classified into an acrylic adhesive, a urethane adhesive, a rubber adhesive, a silicone adhesive, etc., depending on the main polymer, and any one may be used. In addition to the main polymer, a crosslinking agent, a silane compound, an ionic compound, a crosslinking catalyst, an antioxidant, a tackifier, a plasticizer, a dye, a pigment, an inorganic filler and the like may be blended with the pressure-sensitive adhesive. An adhesive layer (adhesive layer) is formed by dissolving and dispersing each component constituting the pressure-sensitive adhesive in a solvent to obtain a pressure-sensitive adhesive composition, applying the pressure-sensitive adhesive composition on a substrate and then drying. The pressure-sensitive adhesive layer may be directly formed, or the adhesive layer may be transferred separately from the substrate. In order to cover the adhesive surface before adhesion, it is also preferable to use a release film. The thickness of the adhesive layer in the case of using the said adhesive is 1-500 micrometers, Preferably it may be 2-300 micrometers. When using the said adhesive for formation of multiple layers, the thickness of each layer and the kind of adhesive used may be same or different.

[Shading Pattern]

The light blocking pattern may be applied as at least a part of a bezel or a housing of the flexible display device. By blocking the wiring arranged on the edge of the flexible display device by the light-shielding pattern and making it difficult to be visually recognized, the visibility of the image is improved. The light-shielding pattern may be in the form of a single layer or a multilayer. The color of the light blocking pattern is not particularly limited, and may have various colors such as black, white, and metallic colors. The light-shielding pattern may be formed of a pigment for realizing a color, and a polymer such as an acrylic resin, an ester-based resin, an epoxy-based resin, polyurethane, or silicone. These can also be used individually or in mixture of 2 or more types. The light-shielding pattern may be formed by various methods such as printing, lithography, and inkjet. The thickness of the light-shielding pattern is usually 1 to 100 µm, preferably 2 to 50 µm. Moreover, it is also preferable to provide shapes, such as an inclination, in the thickness direction of a light-shielding pattern.

Example

Hereinafter, the present invention will be described in more detail by way of Examples. "%" and "part" in an example mean mass % and mass part, unless otherwise indicated. First, an evaluation method will be described.

<Measurement of elastic modulus>

The modulus of elasticity of the polyamideimide films obtained in Examples and Comparative Examples was measured using "Autograph AG-IS" manufactured by Shimadzu Corporation. A film having a width of 10 mm was produced, an S-S curve was measured under the conditions of a distance between chucks of 50 mm and a tensile rate of 10 mm/min, and the elastic modulus was calculated from the inclination.

< Measurement of light transmittance >

Based on JIS K 7105:1981, the optical film obtained by the Example and the comparative example was measured for the total light transmittance Tt of a sample with the fully automatic direct-reading haze computer HGM-2DP manufactured by Suga Test Instruments.

< Measurement of humidity expansion coefficient (CME) >

CME was measured using "TMA/SS6100 type (型)" manufactured by Hitachi High-Tech Sciences. Specifically, a film having a width of 2 mm and a length of 20 mm is placed on the chuck in a nitrogen atmosphere (distance between chucks 10 mm), and held at 60° C. and 0% RH under a load of 20 mN until saturation, and then 60 The humidity expansion coefficient of the film was measured at the time of controlling at °C and 90% RH and holding it for 1 hour. In the humidity expansion coefficient, let the length of the film be L (mm), the amount of change in the length of the film before and after holding at 90% RH for 1 hour is ΔL (mm), and the amount of change in humidity is ΔM (%) , and is calculated by the following equation.

Humidity expansion coefficient = (1/L) (ΔL/ΔM)

< YI value of film >

The YI value (Yellow Index) of the sample was measured in accordance with JIS K7373:2006 using an ultraviolet visible near-infrared spectrophotometer V-670 manufactured by Nippon Spectroscopy Co., Ltd. After background measurement was performed in the absence of a sample, the sample was set in a sample holder, transmittance was measured for light of 300 to 800 nm, and tristimulus values (X, Y, Z) were obtained. The YI value was calculated based on the following formula.

YI=100×(1.2769X-1.0592Z)/Y

< Heize >

The haze of the optical film was measured with a fully automatic direct-reading haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd. in accordance with JIS K7105:1981.

< Measurement of pencil hardness >

As the surface hardness of the polyamideimide films obtained in Examples and Comparative Examples, the pencil hardness of the film surface was adopted in accordance with JIS K 5600-5-4:1999. The load was 100 g, the scanning speed was 60 mm/min, the presence or absence of a flaw was evaluated in the environment of 4,000 lux, and surface hardness (pencil hardness) was measured.

<Measurement of weight average molecular weight>

Gel Permeation Chromatography (GPC) Measurements

(1) Pretreatment method

DMF eluent (10 mmol/L lithium bromide solution) was added to the sample to a concentration of 2 mg/mL, heated at 80° C. while stirring for 30 minutes, cooled and filtered through a 0.45 µm membrane filter to obtain a measurement solution.

(2) Measurement conditions

Column: Tosoh Co., Ltd. TSKgel α-2500 ((7)7.8 mm diameter × 300 mm) × 1, α-M ((13)7.8 mm diameter × 300 mm) × 2

Eluent: DMF (addition of 10 mmol/L lithium bromide)

Flow rate: 1.0 mL/min

Detector: RI Detector

Column temperature: 40°C

Injection volume: 100 μL

Molecular Weight Standard: Standard Polystyrene

<Measurement of thickness>

The thickness of the polyamideimide films obtained in Examples and Comparative Examples was measured using a micrometer ("ID-C112XBS" manufactured by Mitsutoyo Corporation).

< Example 1 >

[Preparation of polyamideimide resin (1)]

In a nitrogen atmosphere, in a separable flask equipped with a stirring blade, 2,2'-bis(trifluoromethyl)benzidine (TFMB) and N,N-dimethylacetamide (DMAc) were added to a solid content of 4.90% by mass of TFMB. Add as much as possible and dissolve TFMB in DMAc with stirring at room temperature. Next, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA) was added to the flask at a concentration of 30.30 mol% based on TFMB, followed by stirring at room temperature for 3 hours. Then, after cooling to 10 ℃, 4,4'oxybis (benzoyl chloride) (OBBC) 5.05 mol% based on TFMB, 2,5-bis (trifluoromethyl) terephthalic acid chloride (6FTPC) in TFMB It was added so as to be 27.28 mol%, and after stirring for 10 minutes, 5.05 mol% of OBBC and 27.28 mol% of 6FTPC were further added to TFMB, followed by stirring for 30 minutes. Thereafter, DMAc in the same amount as the DMAc added initially was added, and after stirring for 10 minutes, 6FTPC was added so as to become 6.06 mol% based on TFMB, and the mixture was stirred for 2 hours. Then, 70.71 mol% of diisopropylethylamine and 4-picoline with respect to TFMB, and 212.12 mol% of acetic anhydride with respect to TFMB were added to the flask, stirred for 30 minutes, and then the internal temperature was raised to 70 ° C., Further, the mixture was stirred for 3 hours to obtain a reaction solution.

The obtained reaction liquid was cooled to room temperature, and it injected|threw-in in the form of a thread in a large amount of methanol, the deposit which precipitated was taken out, immersed in methanol for 6 hours, and then wash|cleaned with methanol. Next, the precipitate was dried under reduced pressure at 60°C to obtain polyamideimide resin (1).

[Preparation of polyamideimide film (1)]

DMAc was added to the obtained polyamideimide resin (1) so that the concentration was 10% by mass to prepare a polyamideimide varnish (1). The obtained polyamideimide varnish (1) was coated on the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") using an applicator so that the thickness of the self-supporting film was 50 µm, and then applied at 50°C for 30 minutes. Then, it dried at 140 degreeC for 15 minutes, and obtained the self-supporting film. The free-standing film was fixed to a metal mold and further dried at 200°C for 60 minutes to obtain a polyamideimide film (1) having a thickness of 45 µm.

< Example 2 >

[Preparation of polyamideimide resin (2)]

In a nitrogen atmosphere, in a separable flask equipped with a stirring blade, TFMB and DMAc were added so that the solid content of TFMB was 2.36 mass %, and TFMB was dissolved in DMAc while stirring at room temperature. Next, 6FDA was added to the flask so as to be 30.30 mol% based on TFMB, and the mixture was stirred at room temperature for 3 hours. Then, after cooling to 10° C., OBBC was added in 5.05 mol% with respect to TFMB, 2,2'-bis(trifluoromethyl)-4,4'-biphenyldicarboxylic acid chloride (6FBPDOC) with respect to TFMB It was added so as to be 27.28 mol%, and after stirring for 10 minutes, 5.05 mol% of OBBC and 27.28 mol% of 6FBPDOC were further added with respect to TFMB, followed by stirring for 30 minutes. Thereafter, DMAc in the same amount as the DMAc added initially was added, and after stirring for 10 minutes, 6FBPDOC was added so as to be 6.06 mol% based on TFMB, and the mixture was stirred for 2 hours. Then, 70.71 mol% of diisopropylethylamine and 4-picoline with respect to TFMB and 212.12 mol% of acetic anhydride with respect to TFMB were added to the flask, and after stirring for 30 minutes, the internal temperature was raised to 70 ° C., Further, the mixture was stirred for 3 hours to obtain a reaction solution.

The obtained reaction liquid was cooled to room temperature, and it injected|threw-in in the form of a thread in a large amount of methanol, the deposit which precipitated was taken out, immersed in methanol for 6 hours, and then wash|cleaned with methanol. Next, the precipitate was dried under reduced pressure at 60°C to obtain polyamideimide resin (2).

[Preparation of polyamideimide film (2)]

DMAc was added to the obtained polyamideimide resin (2) so that the concentration was 10% by mass to prepare a polyamideimide varnish (2). The obtained polyamideimide varnish (2) was coated on the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") using an applicator so that the thickness of the self-supporting film was 55 µm, and then applied at 50°C for 30 minutes. Then, it dried at 140 degreeC for 15 minutes, and obtained the self-supporting film. The free-standing film was fixed to a metal mold and further dried at 200°C for 60 minutes to obtain a polyamideimide film (2) having a thickness of 50 µm.

< Comparative Example 1 >

[Preparation of polyamideimide resin (3)]

In a nitrogen atmosphere, in a separable flask equipped with a stirring blade, TFMB and DMAc were added so that the solid content of TFMB was 5.54 mass %, and TFMB was dissolved in DMAc while stirring at room temperature. Next, 6FDA was added to the flask so as to be 30.20 mol% based on TFMB, and the mixture was stirred at room temperature for 3 hours. Then, after cooling to 10° C., OBBC was added to 10.07 mol% based on TFMB and terephthalic acid chloride (TPC) was added to 54.35 mol% based on TFMB, and stirred for 30 minutes. Thereafter, DMAc in the same amount as the DMAc added initially was added, and after stirring for 10 minutes, TPC was added so as to be 6.04 mol% based on TFMB, and the mixture was stirred for 2 hours. Then, 70.46 mol% of diisopropylethylamine and 4-picoline with respect to TFMB and 211.37 mol% of acetic anhydride with respect to TFMB were added to the flask, stirred for 30 minutes, and then the internal temperature was raised to 70 ° C., Further, the mixture was stirred for 3 hours to obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, thrown into a large amount of methanol in the form of yarn, and the precipitated precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 60°C to obtain polyamideimide resin (3).

[Preparation of polyamideimide film (3)]

DMAc was added to the obtained polyamideimide resin (3) so that the concentration was 10% by mass to prepare a polyamideimide varnish (3). The obtained polyamideimide varnish (3) was coated on the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") using an applicator so that the thickness of the self-supporting film was 55 µm, and then applied at 50°C for 30 minutes. Then, it dried at 140 degreeC for 15 minutes, and obtained the self-supporting film. The free-standing film was fixed to a metal frame and further dried at 200°C for 60 minutes to obtain a polyamideimide film (3) having a thickness of 50 µm.

The weight average molecular weight (Mw) of the obtained polyamideimide resins (1) to (3), and the elastic modulus, CME, light transmittance, YI value and haze of the polyamideimide films (1) to (3) were calculated in the above method. measured accordingly. The obtained results are shown in Table 1. Moreover, the pencil hardness of the optical film 1 was 3B, and the pencil hardness of the optical film 2 was 2H.

[Table 1]

Claims (15)

Equation (1):
[Formula 1]

[In formula (1), Ar ¹ represents a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms, and X represents a divalent organic group]
A structural unit represented by, and Formula (2):
[Formula 2]

[In formula (2), X represents a divalent organic group, Y represents a tetravalent organic group]
An optical film comprising a polyamideimide-based resin having at least a structural unit represented by and having a weight average molecular weight of 200,000 to 1,000,000. The method of claim 1,
The optical film in which the C1-C12 fluoroalkyl group ^{in Ar<1>} in Formula (1) is a C1-C12 perfluoroalkyl group. 3. The method according to claim 1 or 2,
The structural unit represented by Formula (1) is Ar ¹ , and Formula (4):
[Formula 3]

[In formula (4),
R ¹ represents a fluoroalkyl group having 1 to 12 carbon atoms,
n and k independently represent an integer of 1 to 4, provided that when n and/or k represent an integer of 2 to 4, a plurality of R ¹ may be the same or different from each other,
* indicates a bonding hand]
An optical film comprising an aromatic group represented by . 4. The method of claim 3,
An optical film, wherein two bonding hands in formula (4) are located in a para position to each other. 5. The method according to claim 3 or 4,
The optical film whose k in Formula (4) is 1 or 2. 6. The method according to any one of claims 3 to 5,
^R<1> in Formula (4) represents a C1-C12 perfluoroalkyl group, and n is 1 or 2, the optical film. 7. The method according to any one of claims 1 to 6,
The structural unit represented by Formula (1) and/or the structural unit represented by Formula (2) is X, Formula (5):
[Formula 4]

[In formula (5),
Ar ² represents a divalent aromatic group which may have a substituent,
V is a single bond, -O-, a diphenylmethylene group, a fluorenyl group, a divalent hydrocarbon group having 1 to 12 carbon atoms, -SO ₂ -, -S-, -CO-, -PO-, -PO ₂ -, represents -N(R ^a )- or -Si(R ^b ) ₂ -, wherein the hydrocarbon group may contain an alicyclic structure, and the hydrogen atoms contained in the hydrocarbon group are, independently of each other, to the halogen atom may be substituted with, and R ^a and R ^b each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom,
m represents an integer of 0 to 3,
* indicates a bonding hand]
An optical film comprising a divalent organic group represented by 8. The method of claim 7,
The optical film whose m in Formula (5) is 1. 7. The method according to any one of claims 1 to 6,
The structural unit represented by Formula (1) and/or the structural unit represented by Formula (2) is X, Formula (5a):
[Formula 5]

[In formula (5),
R ² represents a fluoroalkyl group having 1 to 12 carbon atoms,
p and q each independently represent an integer of 1 to 4, provided that, when p and/or q represents an integer of 2 to 4, ^{two or} more R 2 may be the same as or different from each other,
* indicates a bonding hand]
An optical film comprising a divalent organic group represented by 7. The method according to any one of claims 1 to 6,
The structural unit represented by Formula (1) and/or the structural unit represented by Formula (2) is X, and Formula (5c):
[Formula 6]

[* in formula (5c) represents a bond]
An optical film comprising a divalent organic group represented by 11. The method according to any one of claims 1 to 10,
An optical film having a thickness of 10-200 μm. The flexible display device provided with the film in any one of Claims 1-11. 13. The method of claim 12,
A flexible display device further comprising a touch sensor. 14. The method according to claim 12 or 13,
A flexible display device further comprising a polarizing plate. Equation (1):
[Formula 7]

[In formula (1),
Ar ¹ represents a divalent aromatic group having a fluoroalkyl group having 1 to 12 carbon atoms,
X represents a divalent organic group]
^{, and as Ar 1} in Formula (1), Formula (4):
[Formula 8]

[in formula (4),
R ¹ represents a fluoroalkyl group having 1 to 12 carbon atoms,
n and k independently represent an integer of 1 to 4, provided that when n and/or k represent an integer of 2 to 4, a plurality of R ¹ may be the same or different from each other,
* indicates a bond]
A structural unit comprising an aromatic group represented by, and Formula (2):
[Formula 9]

[In formula (2), X represents a divalent organic group, Y represents a tetravalent organic group]
A polyamideimide-based resin having at least a structural unit represented by