KR20200026092A - Optical film - Google Patents

Abstract

Provided is an optical film which has reduced partial unevenness in thickness and has excellent planarity of a film surface. The optical film comprises at least one resin selected from the group consisting of polyimide-based resins and polyamide-based resins having a structure represented by formula (A), wherein in the formula (A), * represents a dangling bond, and the resin satisfies formula (X): A/B × 100 >= 0.03 (%), wherein in the formula (X), A represents a peak area originated from a hydrogen atom that binds to a nitrogen atom in the structure represented by the formula (A) on ^1H-NMR spectrum of the resin, and B represents a peak area in the range where a chemical shift value is 6.5-11.5 ppm on the ^1H-NMR spectrum of the resin.

Description

Optical film {OPTICAL FILM}

This invention relates to the optical film used as a front plate etc. of an image display apparatus, the flexible display apparatus provided with the said optical film, and the resin for optics which can form the said optical film.

Image display apparatuses, such as a liquid crystal display device and an organic electroluminescence display, are widely utilized for various uses, such as a mobile telephone and a smart watch. Although glass has been used as a front plate of such an image display apparatus, since glass is very rigid and fragile, it is difficult to use it as a front plate material, such as a flexible display, for example. As a material which replaces glass, polyimide-type resin and polyamide-type resin are mentioned, and the optical film using such resin is examined (for example, patent document 1).

Japanese Patent Publication No. 2015-521687

Such an optical film is obtained by applying a varnish prepared by dissolving a polyimide resin or a polyamide resin in a solvent and then applying the varnish to a support material, followed by drying or the like. However, according to examination by the present inventors, a part of varnish may gelatinize in an optical film manufacturing process, As a result, the partial thickness nonuniformity tends to arise in the optical film obtained, and the flatness of a film surface is impaired. We knew that there might be.

Therefore, the objective of this invention is providing the optical film excellent in the flatness of a film surface, and the nonuniformity of a partial thickness, and the flexible display apparatus provided with this optical film.

Moreover, another object of this invention is to provide the resin for optics which can form the optical film excellent in the flatness of a film surface, and the nonuniformity of a partial thickness is small.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, this inventor is an optical film containing at least 1 sort (s) of resin chosen from the group which consists of polyimide-type resin and polyamide-type resin which have a structure represented by Formula (A). WHEREIN: When the said resin satisfied Formula (X), it discovered that the said subject could be solved and came to complete this invention. That is, the following aspects are included in the present invention.

[1] Formula (A)

[Formula 1]

[In formula (A), * represents a bond.]

At least 1 sort (s) of resin chosen from the group which consists of polyimide-type resin and polyamide-type resin which have a structure represented by these, and the said resin is Formula (X)

A / B × 100≥0.03 (%) (X)

[In Formula (X), A represents the peak area derived from the hydrogen atom couple | bonded with the nitrogen atom in the structure represented by Formula (A) in <^1> H-NMR spectrum of this resin, B is the said resin. In the ¹ H-NMR spectrum, the chemical shift value represents the peak area in the range of 6.5 to 11.5 ppm.]

To meet the optical film.

[2] The polyimide resin having a structure represented by formula (A) is formula (1)

[Formula 2]

[In Formula (1), Y is a tetravalent organic group and X is a divalent organic group.]

Containing a structural unit represented by

Polyamide-type resin which has a structure represented by Formula (A) is Formula (2)

[Formula 3]

[In Formula (2), Z and X are each independently a divalent organic group.]

The optical film as described in [1] containing the structural unit represented by these.

[3] At least a part of the structure represented by formula (A) is represented by formula (B).

[Formula 4]

[In formula (B), * represents a bond.]

The optical film as described in [1] or [2] which is a structure shown by these.

[4] The weight average molecular weight of at least one resin selected from the group consisting of a polyimide resin and a polyamide resin having a structure represented by formula (A) is 200,000 or more, in [1] to [3]. The optical film as described in any one.

[5] The optical film according to any one of [1] to [4], further comprising silica particles.

[6] The optical film according to any one of [1] to [5], wherein the thickness is 25 to 100 µm.

[7] A flexible display device comprising the optical film according to any one of [1] to [6].

[8] The flexible display device according to [7], further comprising a touch sensor.

[9] The flexible display device according to [7] or [8], further comprising a polarizing plate.

[10] Formula (A)

[Formula 5]

[In formula (A), * represents a bond.]

As optical resin containing at least 1 sort (s) chosen from the group which consists of polyimide-type resin and polyamide-type resin which have a structure represented by the formula (X)

A / B × 100≥0.03 (%) (X)

[In Formula (X), A represents the peak area derived from the hydrogen atom couple | bonded with the nitrogen atom in the structure represented by Formula (A) in <^1> H-NMR spectrum of the said optical resin, B is In the ¹ H-NMR spectrum of the optical resin, a chemical shift value represents a peak area in a range of 6.5 to 11.5 ppm.]

To meet the optical resin.

The optical film of this invention is small in the nonuniformity of partial thickness, and is excellent in the flatness of a film surface. Moreover, the optical resin of this invention is small in the nonuniformity of a partial thickness, and can form the optical film excellent in the flatness of a film surface.

[Optical film]

The optical film of the present invention is formula (A)

[Formula 6]

[In formula (A), * represents a bond.]

At least 1 sort (s) of resin chosen from the group which consists of polyimide-type resin and polyamide-type resin which have a structure represented by these are included.

<Resin>

The said polyimide resin consists of a polymer containing a repeating structural unit containing an imide group, and a polymer containing a repeating structural unit containing both an imide group and an amide group (sometimes called polyamideimide). At least one polymer selected from the group is shown. In addition, the said polyamide resin shows the polymer containing the repeating structural unit containing an amide group.

It is preferable that a polyimide resin is polyamide imide from a viewpoint of improving the surface flatness and optical characteristics of an optical film. In addition, in this specification, a repeating structural unit may be called a structural unit. The structural unit represented by Formula (1) may be described as structural unit (1). The structure represented by Formula (A) may be described as structure (A). The same is true if the number in parentheses is changed.

The structure (A) (sometimes called an acetamide group (A)) contained in the said resin represents the acetamide group formed by acetylating the amine terminal in polyimide resin or polyamide resin.

In the optical film of the present invention, the resin is formula (X)

A / B × 100≥0.03 (%) (X)

[In Formula (X), A represents the peak area derived from the hydrogen atom couple | bonded with the nitrogen atom in the structure represented by Formula (A) in <^1> H-NMR spectrum of this resin, B is the said resin. In the ¹ H-NMR spectrum, the chemical shift value represents the peak area in the range of 6.5 to 11.5 ppm.]

Meets. The ¹ H-NMR spectrum of the resin can be obtained by, for example, measuring ¹ H-NMR of a deuterated dimethyl sulfoxide (referred to as DMSO-d ₆ ) solution of the resin under the following conditions, for example It can obtain by the method as described in an Example.

Measuring solution: DMSO-d ₆ solution of resin (resin concentration 2% by mass)

Measuring device: NMR device

Measuring solution temperature: 303K

Measurement Method: ¹ H-NMR

Chemical Shift Reference: DMSO (2.50 ppm)

When the area value is obtained from the obtained ¹ H-NMR spectrum, appropriate baseline correction is performed for each of the peak derived from the hydrogen atom bonded to the nitrogen atom in the structure represented by the formula (A) and the range of 6.5 to 11.5 ppm. It is preferable.

The peak derived from the hydrogen atom bonded to the nitrogen atom in the structure (A) may change depending on the chemical structure of the structural unit having the structure (A), but the nitrogen atom in the structure (A) by performing two-dimensional NMR measurement It can confirm that it is a hydrogen atom couple | bonded with. For example, when the HMBC measurement of the measurement solution is performed, the mutual shift between the chemical shift of the hydrogen atom bonded to the nitrogen atom in the structure (A) and the chemical shift of the carbon atom of the methyl group in the structure (A) is 3 This can be confirmed by the detection of an HMBC signal that is present within the binding. The chemical shift value of the peak derived from the hydrogen atom bonded to the nitrogen atom in the structure (A) is, for example, 10.1 to 10.7 ppm, preferably 10.2 to 10.6 ppm, and more preferably 10.3 to 10.4 ppm.

A / B × 100 in the formula (X) is a nitrogen atom in the structure (A) on the basis of the peak area in the range of 6.5 to 11.5 ppm in the chemical shift value in the ¹ H-NMR spectrum of the resin. The peak area derived from the hydrogen atom which couple | bonds with to is shown as a percentage, ie, the structure (based on content in resin of the hydrogen atom whose chemical shift value in ¹ H-NMR spectrum is detected at 6.5-11.5 ppm) It can also be said that content of the hydrogen atom couple | bonded with the nitrogen atom in A) was shown in percentage. Therefore, the value of A / Bx100 of Formula (X) can be adjusted by changing content of structure (A) in resin, for example, and if content of structure (A) is enlarged, it will be A / Bx. The value of 100 increases, and when content of structure (A) is made small, the value of A / Bx100 will decrease. In addition, in order to enlarge content of structure (A), what is necessary is just to increase the acetylation amount of the amine terminal in resin, for example.

In the present invention, since the resin satisfies the relationship of the formula (X), that is, A / B × 100 is 0.03% or more, and the resin has a predetermined amount or more of the structure (A), the resin in the film production process The gelation of the varnish can be effectively suppressed. Therefore, the optical film of this invention is small in the nonuniformity of partial thickness, and can have the outstanding flatness of the film surface. Such a gelling inhibitory effect is estimated to be because the amine terminal in resin is acetylated more than predetermined amount, and has a predetermined amount or more of acetamide group (A). In addition, in this specification, flatness can be evaluated by the nonuniformity of the partial thickness of a film, and improving flatness means that the nonuniformity of the partial thickness of a film becomes smaller. The nonuniformity of the partial thickness of a film can be evaluated by measuring thickness distribution like an Example, for example. In addition, in this specification, an "optical characteristic" shows the optically evaluable characteristic which includes a total light transmittance, yellowness, and haze, for example.

Since the optical film of this invention contains resin which satisfy | fills the relationship of Formula (X), since the gelation of resin varnish can be suppressed effectively in a film manufacturing process, high total light transmittance and low yellowness (YI) Value) and low haze and the like.

In Formula (X), A / Bx100 becomes like this. Preferably it is 0.04% or more, More preferably, it is 0.05% or more. If A / Bx100 is more than the said minimum, it will be easy to improve the flatness and optical characteristics of an optical film more. In addition, the upper limit of A / Bx100 is not specifically limited, For example, it is 1.0% or less, Preferably it is 0.5% or less. If A / B × 100 is equal to or less than the above upper limit, mechanical properties such as bending resistance tend to be good.

In a preferred embodiment of the present invention, at least a part of the structure represented by the formula (A) is a formula (B), from the viewpoint of ease of gelation of the resin varnish and easy improvement of the flatness and optical properties of the optical film.

[Formula 7]

[In formula (B), * represents a bond.]

It is preferable that it is a structure shown by.

The structure (A) in the resin (A) is preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70 mol% or more, and particularly preferably 90 mol% or more. If more than the said minimum of the structure (A) in resin is a structure (B), it will be easy to improve the flatness and optical characteristic of an optical film more. Moreover, preferably 100 mol% or less of the structure (A) in the said resin is a structure (B). Ratio of the structure (A) of the structure (B) is, for example, can be measured by using a ¹ H-NMR, or can be calculated from the raw material doipbi.

Below, the specific embodiment of the polyimide-type resin or polyamide-type resin (henceforth called resin (P)) which has a structure (A) in this invention is shown. However, the present invention is not limited to the following aspects.

In a preferred embodiment of the present invention, the polyimide resin includes a structural unit represented by formula (1), and the polyamideimide is represented by a structural unit represented by formula (1) and formula (2). Includes losing units. In addition, polyamide resin contains the structural unit represented by Formula (2).

[Formula 8]

[In Formula (1) and Formula (2), Y is a tetravalent organic group, X and Z are respectively independently a divalent organic group.]

The repeating structural unit represented by formula (1) is a structure represented by formula (1 ') in which X of formula (1) is bonded to structure (A) at the terminal of the resin so as to satisfy the relationship of formula (X). The repeating structural unit which contains a unit and is represented by Formula (2) is Formula (2 ') which X of Formula (2) couple | bonded with Structure (A) at the terminal of resin so that the relationship of Formula (X) may be satisfied. It includes a structural unit represented by).

[Formula 9]

[In Formula (1 ') and Formula (2'), Y is a tetravalent organic group, X and Z are respectively independently a divalent organic group.]

Gelling of the resin varnish in a film manufacturing process by including structural unit (1 ') and / or structural unit (2') so that polyimide-type resin or polyamide-type resin may satisfy | fill the relationship of Formula (X). Can be effectively suppressed, and as a result, an optical film excellent in the flatness of the film surface can be obtained. Moreover, the said optical film can also express the outstanding optical characteristics, such as high light transmittance, low yellowness, and low haze.

In formula (1), formula (1 '), formula (2), and formula (2') (Hereinafter, it may be described as formula (1)-formula (2 ').) X is respectively independently , A divalent organic group, preferably a divalent organic group having 4 to 40 carbon atoms, and more preferably a divalent organic group having 4 to 40 carbon atoms having a cyclic structure. Examples of the cyclic structure include an alicyclic, aromatic ring, and heterocyclic structure. The said organic group may be substituted by the hydrogen group in the organic group by the hydrocarbon group or the fluorine-substituted hydrocarbon group, In that case, carbon number of a hydrocarbon group and a fluorine-substituted hydrocarbon group becomes like this. Preferably it is 1-8. The polyimide resin or the polyamide resin, which is an embodiment of the present invention, may include a plurality of types of X, and the plurality of types of X may be the same as or different from each other. As X, it is represented by Formula (10), Formula (11), Formula (12), Formula (13), Formula (14), Formula (15), Formula (16), Formula (17) and Formula (18). group; A group in which a hydrogen atom in the group represented by such formulas (10) to (18) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And a chain hydrocarbon group having 6 or less carbon atoms is exemplified.

[Formula 10]

In formulas (10) to (18), * represents a bond.

V ¹ , V ² and V ³ are each independently a single bond, -O-, -S-, -CH _2- , -CH ₂ -CH _2- , -CH (CH ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO _2- , -CO- or -NQ-. Here, Q represents a C1-C12 hydrocarbon group which may be substituted by the halogen atom.

One example is that V ¹ and V ³ are a single bond, -O- or -S-, and V ² is -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- Or -SO _2- . The bonding position for each ring of V ¹ and V ² and the bonding position for each ring of V ² and V ³ are each preferably a meta position or a para position, more preferably a para position, for each ring. to be.

Among the groups represented by the formulas (10) to (18), from the viewpoint of easily improving the surface hardness and the bend resistance of the optical film, the formulas (13), (14), (15), (16) and Group represented by Formula (17) is preferable, and group represented by Formula (14), Formula (15), and Formula (16) is more preferable. Further, V ^1, V ² and V ³ is, in an easy to improve the surface hardness and flexibility point of view of the optical film, each independently, a single bond, preferably a -O- or -S-, and a bond or -O It is more preferable that it is-.

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

[Formula 11]

[In formula (4), R <^10> -R <^17> represents a hydrogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, or a C6-C12 aryl group each independently, and R <^10> -R The hydrogen atoms contained in ¹⁷ may be each independently substituted with a halogen atom, and * represents a bond.]

It is group represented by. If at least one part of the some X in Formula (1)-Formula (2 ') is group represented by Formula (4), it is easy to improve the surface hardness, flatness, optical characteristic, etc. of an optical film.

In Formula (4), R <^10> , R <^11> , R <^12> , R <^13> , R <^14> , R <^15> , R <^16> and R <^17> are respectively independently a hydrogen atom, a C1-C6 alkyl group, and C1-C6 An alkoxy group or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group and 2-methyl-butyl group , 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl group and the like. As a C6-C12 aryl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group etc. are mentioned, for example. Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butoxy group, isobutoxy group, tert-butoxy group, pentyloxy group, hexyloxy group and cyclohexyl octa Season, etc. can be mentioned. R ¹⁰ to R ¹⁷ each independently, preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, where R ¹⁰ to R ¹⁷ are The hydrogen atoms contained may be each independently substituted with a halogen atom. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, for example. R ¹⁰ to R ¹⁷ are each independently, from the viewpoint of easily improving the flatness, optical properties, surface hardness, or bend resistance of the optical film, more preferably hydrogen atom, methyl group, fluoro group, chloro group or trifluoro Methyl group, and particularly preferably R ¹⁰ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are hydrogen atoms, R ¹¹ and R ¹⁷ are hydrogen atoms, methyl group, fluoro group, chloro group or trifluoromethyl group In particular, it is preferable that R ¹¹ and R ¹⁷ be a methyl group or a trifluoromethyl group.

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

[Formula 12]

In other words, at least a part of the plurality of X's is a group represented by the formula (4 '). When polyimide-type resin or polyamide-type resin has group represented by (4 ') in at least one part of several X in structural unit (1') and / or structural unit (2 '), the said polyimide system Resin or polyamide resin has a structure (B). In this case, since the solubility of a resin in the solvent improves by the frame | skeleton containing a fluorine element, and gelatinization of a resin varnish is easy to suppress, it is easy to improve the flatness and optical characteristics of an optical film.

In a preferred embodiment of the present invention, X of the resin (P), preferably at least 30 mol%, more preferably at least 50 mol%, even more preferably at least 70 mol% is formula (4), in particular formula It is represented by (4 '). When X in the said range in the said resin is represented by Formula (4), especially Formula (4 '), the solubility to the solvent of the said resin improves by the skeleton containing a fluorine element, and suppresses gelation of the resin varnish. Since it is easy to do it, it is easy to improve the flatness and optical characteristics of an optical film. Moreover, Preferably, 100 mol% or less of X in resin (P) is represented by Formula (4), especially Formula (4 '). X in resin (P) may be Formula (4), especially Formula (4 '). Ratio of groups represented by the formula (4) X in the resin (P) is, for example, can be measured by using a ¹ H-NMR, or may be calculated from the raw material doipbi.

In formula (2) and formula (2 '), Z is a divalent organic group each independently, Preferably, even if it is substituted by the C1-C8 hydrocarbon group or the fluorine-substituted C1-C8 hydrocarbon group, C4-C40 bivalent organic group which has a cyclic structure which is a C4-C40 organic group, More preferably, it may be substituted by the C1-C8 hydrocarbon group or the fluorine-substituted C1-C8 hydrocarbon group. Group. Examples of the cyclic structure include an alicyclic, aromatic ring, and heterocyclic structure. As an organic group of Z, Formula (20), Formula (21), Formula (22), Formula (23), Formula (24), Formula (25), Formula (26), Formula (27) and Formula (to be described later) 28) and group in which two nonadjacent groups are substituted by the hydrogen atom among the bond loss of the group represented by Formula (29), and the divalent chain hydrocarbon group of 6 or less carbon atoms are illustrated. In particular, a group represented by the formulas (20) to (27) is preferable from the viewpoint of easily suppressing the yellowness of the optical film (reducing the YI value) and improving the optical characteristics.

In one embodiment of the present invention, the polyimide resin or the polyamide resin having the structure (A) may include a plurality of types of Z, and the plurality of types of Z may be the same as or different from each other. In particular, in view of the fact that the optical film tends to exhibit excellent optical properties in addition to higher flatness and surface hardness, at least a part of Z is represented by Formula (3)

[Formula 13]

Equation (3) of, R ¹ ~R ⁸ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group, or an aryl group of 6 to 12 carbon atoms having 1 to 6 carbon atoms of, R ¹ ~R ⁸ The hydrogen atoms contained in each may be independently substituted with a halogen atom, and 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 -NR ^9- , and R ⁹ is carbon number which may be substituted with a hydrogen atom or a halogen atom; A hydrocarbon group of 1 to 12, m is an integer of 0 to 4, and * represents a bond.]

It is preferable that it is represented by.

In Formula (3), A is respectively independently 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 -NR ^9- , and from the viewpoint of the bend resistance of the optical film, preferably -O- or -S- More preferably -O-. R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ 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 6 carbon atoms The aryl group of -12 is shown. As a C1-C6 alkyl group, a C1-C6 alkoxy group, and a C6-C12 aryl group, a C1-C6 alkyl group, C1-C6 alkoxy group, or C6-C12 in Formula (4) Examples of the aryl group include those exemplified above. From the viewpoint of the surface hardness and the flexibility of the optical film, R ¹ to R ⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. And more preferably a hydrogen atom. Here, the hydrogen atoms contained in R ¹ to R ⁸ may be each independently substituted with a halogen atom. R <^9> represents the C1-C12 hydrocarbon group which may be substituted by the hydrogen atom and the halogen atom.

In Formula (3), m is an integer of the range of 0-4, and if m is in this range, the bending resistance and elastic modulus of an optical film are favorable. In addition, in Formula (3), m is preferably an integer in the range of 0-3, More preferably, it is 0-2, More preferably, it is 0 or 1, When m is in this range, The bending resistance and the elastic modulus are good, and the availability of the raw material is relatively good. In addition, Z may contain 1 type, or 2 or more types of group represented by Formula (3), and especially the value of m from a viewpoint of the improvement of the elasticity modulus, bending resistance, and yellowness (YI value) reduction of an optical film. Two or more types of these different groups, Preferably two types of groups different from each other may be included. In that case, it is preferable that an optical film contains both groups whose m is 0 and 1 from a viewpoint which is easy to express high elasticity modulus, bending resistance, and low yellowness (YI value).

In a preferred embodiment of the invention, formula (3) is formula (3 '):

[Formula 14]

In other words, at least a part of the plurality of Z is a group represented by the formula (3 '). In this case, an optical film is easy to improve surface hardness and bending resistance, and also easy to reduce yellowness.

In a preferred embodiment of the present invention, the group represented by the formula (3) is preferably about the total of the structural unit represented by the formula (1) in the resin (P) and the structural unit represented by the formula (2). 20 mol% or more, more preferably 30 mol% or more, more preferably 40 mol% or more, particularly preferably 50 mol% or more, most preferably 60 mol% or more, preferably 90 mol% or less, More preferably, it is 85 mol% or less, More preferably, it is 80 mol% or less. When the group represented by Formula (3) is more than the said lower limit with respect to the sum total of the structural unit represented by Formula (1) in resin (P), and the structural unit represented by Formula (2), an optical film has surface hardness, Flex resistance and elastic modulus may be excellent. Amide derived from formula (3) when the group represented by formula (3) is less than or equal to the above upper limit with respect to the total of the structural unit represented by formula (1) in the resin (P) and the structural unit represented by formula (2). It is easy to suppress gelation resulting from hydrogen bonding between bonds, and it is easy to raise the flatness and optical characteristics of an optical film.

Moreover, in a suitable embodiment of this invention, m of Formula (3) is 1-4 with respect to the sum total of the structural unit represented by Formula (1) of resin (P), and the structural unit represented by Formula (2). The group represented by is preferably 3 mol% or more, more preferably 5 mol% or more, even more preferably 7 mol% or more, particularly preferably 9 mol% or more, preferably 90 mol% or less, more Preferably it is 70 mol% or less, More preferably, it is 50 mol% or less, Especially preferably, it is 30 mol% or less. With respect to the total of the structural unit represented by the formula (1) in the resin (P) and the structural unit represented by the formula (2), when m in the formula (3) is represented by 1 to 4 or more, the optical It is easy to improve the surface hardness and bending resistance of a film further. About the sum total of the structural unit represented by Formula (1) in resin (P), and the structural unit represented by Formula (2), if m of Formula (3) is group represented by 1-4, it is a formula below (3) It is easy to suppress the gelation resulting from the hydrogen bond between amide bonds derived from it, and to improve the flatness and optical characteristics of an optical film. The content of groups represented by the formula (3) is, for example, can be measured by using a ¹ H-NMR, or may be calculated from the raw material doipbi.

In a preferred embodiment of the present invention, Z in resin (P) is preferably at least 30 mol%, more preferably at least 50 mol%, even more preferably at least 60 mol%, particularly preferably 70 mol%. The above is represented by Formula (3). When more than the said lower limit of Z of resin (P) is represented by Formula (3), it is easy to improve the surface hardness and bending resistance of an optical film. In addition, it is preferable that preferably 100 mol% or less of Z in resin (P) is represented by Formula (3). When below the said upper limit of Z of resin (P) is represented by Formula (3), it is easy to suppress gelation resulting from hydrogen bonds between the amide bonds derived from Formula (3), and it is easy to raise the flatness and optical characteristics of an optical film. .

In a preferred embodiment of the present invention, Z in the resin (P) is preferably at least 5 mol%, more preferably at least 8 mol%, even more preferably at least 10 mol%, particularly preferably 12 mol%. The above is represented by Formula (3) when m is 1-4. When more than the said lower limit of Z of resin (P) is represented by Formula (3) when m is 1-4, it is easy to improve the surface hardness and bending resistance of an optical film. Moreover, preferably 90 mol% or less of Z in resin (P), More preferably, it is 70 mol% or less, More preferably, it is 50 mol% or less, Especially preferably, it is 30 mol% or less, m is 1- It is preferable that it is represented by Formula (3) in the case of 4. When below the said upper limit of Z of resin (P) is represented by Formula (3) when m is 1-4, it originates in the hydrogen bond between amide bonds derived from Formula (3) when m is 1-4. It is easy to suppress gelation, and it is easy to raise the flatness and optical characteristics of an optical film. The resin (P) in a ratio of the group represented by the formula (3) in the case where m is 1 to 4, for example, can be measured by using a ¹ H-NMR, or be calculated from the raw material doipbi It may be.

In Formula (1) and Formula (1 '), Y represents a tetravalent organic group each independently, Preferably it represents a C4-C40 tetravalent organic group, More preferably, it has C4 which has a cyclic structure. The tetravalent organic group of -40 is represented. Examples of the cyclic structure include an alicyclic, aromatic ring, and heterocyclic structure. The said organic group is the organic group by which the hydrogen atom in the organic group may be substituted by the hydrocarbon group or the fluorine-substituted hydrocarbon group, In that case, carbon number of a hydrocarbon group and a fluorine-substituted hydrocarbon group becomes like this. Preferably it is 1-8. The polyimide resin which has a structure (A) which is one Embodiment of this invention may contain multiple types of Y, and multiple types of Y may mutually be same or different. As Y, the following formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) and A group represented by formula (29); A group in which a hydrogen atom in the group represented by such formulas (20) to (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And a tetravalent hydrocarbon group having 6 or less carbon atoms is exemplified.

[Formula 15]

In formulas (20) to (29),

* Represents a bonding hand,

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-O-Ar-, -Ar-CH ₂ -Ar-, -Ar-C (CH ₃ ) ₂ -Ar- Or -Ar-SO ₂ -Ar-. Ar represents the C6-C20 arylene group in which a hydrogen atom may be substituted by the fluorine atom, and a phenylene group is mentioned as a specific example.

Among the groups represented by the formulas (20) to (29), from the viewpoint of the surface hardness and the flex resistance of the optical film, the group represented by the formula (26), the formula (28) or the formula (29) is preferable, and the formula ( Group represented by 26) is more preferable. W ¹ is a single bond, -O-, -CH _2- , -CH ₂ -CH _2- , or -CH, each independently from the viewpoint of easily suppressing the surface hardness, the bending resistance, and the yellowness of the optical film. (CH ₃ )-, -C (CH ₃ ) ₂ -or -C (CF ₃ ) ₂ -is preferably a single bond, -O-, -CH _2- , -CH (CH ₃ )-, -C More preferably, it is (CH ₃ ) ₂ -or -C (CF ₃ ) _2- , more preferably a single bond, -C (CH ₃ ) ₂ -or -C (CF ₃ ) _2- , and a single bond or Particular preference is given to -C (CF ₃ ) _2- .

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

[Formula 16]

[Equation (5) of, R ¹⁸ ~R ²⁵ are, each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group, or an aryl group of 6 to 12 carbon atoms having 1 to 6 carbon atoms in, R ¹⁸ ~R The hydrogen atoms contained in ²⁵ may be each independently substituted with a halogen atom, and * represents a bond.]

It is group represented by. If at least one part of some Y in Formula (1) and Formula (1 ') is group represented by Formula (5), an optical film is easy to improve flatness and an optical characteristic.

In Formula (5), R <^18> , R <^19> , R <^20> , R <^21> , R <^22> , R <^23> , R <^24> and R <^25> are respectively independently a hydrogen atom, a C1-C6 alkyl group, and C1-C6 An alkoxy group or an aryl group having 6 to 12 carbon atoms. As a C1-C6 alkyl group, a C1-C6 alkoxy group, and a C6-C12 aryl group, a C1-C6 alkyl group, C1-C6 alkoxy group, or C6-C12 in Formula (4) Examples of the aryl group include those exemplified above. R ¹⁸ to R ²⁵ each independently, preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, where R ¹⁸ to R ²⁵ The hydrogen atoms contained may be each independently substituted with a halogen atom. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned. R ¹⁸ to R ²⁵ are each independently, from the viewpoint of easily improving the surface hardness, bending resistance, flatness or optical properties of the optical film, more preferably hydrogen atom, methyl group, fluoro group, chloro group or trifluoro Methyl group, even more preferably R ¹⁸ , R ¹⁹ , R ²⁰ , R ²³ , R ²⁴ and R ²⁵ are hydrogen atoms, R ²¹ and R ²² are hydrogen atoms, methyl group, fluoro group, chloro group or trifluoro It is a methyl group, It is especially preferable that R <^21> and R <^22> is a methyl group or a trifluoromethyl group.

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

[Formula 17]

In other words, at least a part of the plurality of Y's is a group represented by the formula (5 '). In this case, the optical film can have more excellent flatness and optical properties.

In a preferred embodiment of the present invention, preferably, at least 50 mol%, more preferably at least 60 mol%, even more preferably at least 70 mol% of Y in the polyimide resin having the structure (A) (5), especially represented by Formula (5 '). When Y in the said range in the said polyimide-type resin is represented by Formula (5), especially Formula (5 '), an optical film is easy to improve flatness and an optical characteristic. Moreover, Preferably, 100 mol% or less of Y in the said polyimide resin is represented by Formula (5), especially Formula (5 '). Formula (5), especially Formula (5 ') may be sufficient as Y in the said polyimide resin. Ratio of groups represented by formula (5) of the Y in the art polyimide-based resin is, for example, can be measured by using a ¹ H-NMR, or may be calculated from the raw material doipbi.

The polyimide resin or polyamide resin having the structure (A) is a structural unit represented by formula (30) and / or formula (31), in addition to the structural units represented by formula (1) and formula (2). It may include a structural unit represented.

[Formula 18]

The repeating structural unit represented by formula (30) is represented by formula (30 ') in which X ¹ of formula (30) is bonded to structure (A) at the terminal of the resin so as to satisfy the relationship of formula (X). The repeating structural unit represented by Formula (31) containing a structural unit is a formula which X <^2> of Formula (31) ^{couple |} bonded with Structure (A) at the terminal of resin so that the relationship of Formula (X) may be satisfied. And a structural unit represented by 31 ′).

[Formula 19]

In formula (30) and formula (30 '), Y <^1> is a tetravalent organic group each independently, Preferably it is the organic group by which the hydrogen atom in the organic group may be substituted by the hydrocarbon group or the fluorine-substituted hydrocarbon group. . As Y <^1> , Formula (20), Formula (21), Formula (22), Formula (23), Formula (24), Formula (25), Formula (26), Formula (27), Formula (28) and Formula The group represented by (29), the group in which the hydrogen atom in the group represented by such formulas (20) to (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, and a tetravalent carbon number 6 or less Chain hydrocarbon groups are exemplified. One embodiment of the resin (P) of the invention, Y ¹ may comprise a plurality of species, Y ¹ is a plurality of types, and may be same or different from each other.

In Formula (31) and Formula (31 '), Y <^2> is a trivalent organic group, Preferably it is the organic group by which the hydrogen atom in the organic group may be substituted by the hydrocarbon group or the fluorine-substituted hydrocarbon group. As Y <^2> , said Formula (20), Formula (21), Formula (22), Formula (23), Formula (24), Formula (25), Formula (26), Formula (27), and Formula (28). And a group in which any one of the bonds of the group represented by the formula (29) is substituted with a hydrogen atom, and a trivalent C 6 or less chain hydrocarbon group is exemplified. One embodiment of the resin (P) of the invention, may include a plurality of types of Y ^2, Y ² is a plurality of types, and may be same or different from each other.

In Formula (30), Formula (30 '), Formula (31), and Formula (31'), X <^1> and X <^2> are respectively independently divalent organic groups, Preferably the hydrogen atom in an organic group is a hydrocarbon It is an organic group which may be substituted by the group or the fluorine-substituted hydrocarbon group. As X <^1> and X <^2> , said Formula (10), Formula (11), Formula (12), Formula (13), Formula (14), Formula (15), Formula (16), Formula (17), and A group represented by formula (18); A group in which a hydrogen atom in the group represented by such formulas (10) to (18) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And a chain hydrocarbon group having 6 or less carbon atoms is exemplified.

In a preferred embodiment of the present invention, the polyamideimide having structure (A) is a structural unit represented by formulas (1) and (2), and optionally formulas (30) and / or (31) It consists of the structural units represented by. In addition, from the viewpoint of the surface hardness and the flex resistance of the optical film, in the polyamideimide, the structural units represented by the formulas (1) and (2) are represented by formulas (1) and (2), and Therefore, based on all the structural units represented by Formula (30) and Formula (31), Preferably it is 80 mol% or more, More preferably, it is 90 mol% or more, More preferably, it is 95 mol% or more. In addition, in the said polyamideimide, the structural unit represented by Formula (1) and Formula (2) is represented by Formula (1) and Formula (2), and if necessary by Formula (30) and Formula (31). Paper is usually 100% or less based on the entire structural unit. In addition, the said ratio can be measured using <^1> H-NMR, for example, or it can calculate it from the introduction ratio of a raw material.

The weight average molecular weight (Mw) of at least 1 sort (s) of resin chosen from the group which consists of a polyimide-type resin and polyamide-type resin which have a structure (A) is converted in standard polystyrene, Preferably it is 200,000 or more, More preferably, 300,000 or more, more preferably 350,000 or more, particularly preferably 400,000 or more, preferably 1,000,000 or less, more preferably 800,000 or less, even more preferably 700,000 or less, even more preferably 500,000 or less, particularly preferably 450,000 It is as follows. Flexural resistance of an optical film can be improved as the weight average molecular weight of the said resin is more than the said minimum. Moreover, when the weight average molecular weight of the said resin is below the said upper limit, it is easy to suppress gelation of the resin varnish in the manufacturing process of an optical film, and the flatness of an optical film can be improved. In addition, in this specification, a weight average molecular weight can be calculated | required by standard polystyrene conversion, for example by GPC measurement, and you may calculate it by the method as described in an Example, for example.

In the polyamideimide having the structure (A), the content of the structural unit represented by the formula (2) is preferably 0.1 mol or more, more preferably to 1 mol of the structural unit represented by the formula (1). 0.5 mol or more, 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 improve surface hardness as content of the structural unit represented by Formula (2) is more than the said minimum. When content of the structural unit represented by Formula (2) is below the said upper limit, it is easy to suppress gelation of a resin varnish, and it is easy to improve the flatness and optical characteristics of an optical film.

The imidation ratio of the polyamideimide which has a structure (A) becomes like this. Preferably it is 90% or more, More preferably, it is 95% or more, More preferably, it is 98% or more. It is preferable that the imidation ratio is more than the said minimum from a viewpoint of the flatness improvement of an optical film. In addition, the upper limit of the imidation ratio is 100% or less. In addition, the imidation ratio can be calculated | required by IR method, NMR method, etc.

<Production Method of Resin>

The polyamideimide having the structure (A) is, for example, after producing a polyamideimide using the tetracarboxylic acid compound, the dicarboxylic acid compound, and the diamine compound described below as main raw materials, and the terminal amine of the polyamideimide is represented by the following formula: It can be obtained by acetylating a predetermined amount or more so as to satisfy the relationship of (X). The polyimide is, for example, after producing a polyimide using a tetracarboxylic acid compound and a diamine compound described below as the main raw materials, the terminal amine of the polyimide is acetyl or more in a predetermined amount or more so as to satisfy the relationship of the formula (X). Can be obtained. The polyamide is obtained by, for example, acetylating a terminal amine of the polyamide after a predetermined amount or more so as to satisfy the relationship of the formula (X) after production, using the dicarboxylic acid compound and the diamine compound described below as main raw materials. Can be. Here, it is preferable that a dicarboxylic acid compound contains the compound represented by at least Formula (3 '').

[Formula 20]

[In formula (3 ''), R <^1> -R <^8> represents a hydrogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, or a C6-C12 aryl group each independently, and R <^1> The hydrogen atoms contained in the —R ⁸ 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- , -S-, -CO- or -NR ⁹ -is represented, R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydrogen atom or a halogen atom,

m is an integer of 0 to 4,

R ³¹ and R ³² are each independently a hydroxyl group, a methoxy group, an ethoxy group, an n-propoxy group, n-butoxy group or a chlorine atom]

In a suitable embodiment, the dicarboxylic acid compound is a compound represented by formula (3 '') wherein A is an oxygen atom. In another preferred embodiment, the dicarboxylic acid compound is a compound represented by formula (3 '') wherein R ³¹ and R ³² are chlorine atoms. In addition, you may use a diisocyanate compound instead of a diamine compound.

As tetracarboxylic acid compound used for the synthesis | combination of polyimide-type resin, Aromatic tetracarboxylic acid compounds, such as aromatic tetracarboxylic dianhydride; And aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydride and the like. The tetracarboxylic acid compound may be used alone or in combination of two or more thereof. In addition to the dianhydride, the tetracarboxylic acid compound may be a tetracarboxylic acid compound flexible body such as an acid chloride compound.

 Specific examples of the aromatic tetracarboxylic dianhydride include non-condensed polycyclic aromatic tetracarboxylic dianhydrides, monocyclic aromatic tetracarboxylic dianhydrides and condensed polycyclic aromatic tetracarboxylic dianhydrides. As a non-condensed polycyclic aromatic tetracarboxylic dianhydride, For example, 4,4'- oxydiphthalic dianhydride, 3,3 ', 4,4'- benzophenone tetracarboxylic dianhydride, 2,2', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (may be referred to as BPDA), 2,2', 3,3'- Biphenyltetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfontetracarboxylic 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 (May be 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, S (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, 4,4 '-(p-phenylenedioxy) diphthalic dianhydride, 4,4'- (m-phenylenedioxy) diphthalic dianhydride is mentioned. Examples of the monocyclic aromatic tetracarboxylic dianhydride include 1,2,4,5-benzenetetracarboxylic dianhydride. Examples of the condensed polycyclic aromatic tetracarboxylic dianhydride include, for example. 2,3,6,7-naphthalene tetracarboxylic dianhydride is mentioned.

Among these, 4,4'- oxydiphthalic dianhydride, 3,3 ', 4,4'- benzophenone tetracarboxylic dianhydride, 2,2', 3,3'- benzophenone tetracarboxylic acid Dianhydrides, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3,3 ', 4,4'-di Phenylsulfontetracarboxylic 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 Dianhydrides, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydrides, 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydrides, 1,1-bis (3,4-di Carboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, 4,4 '-(p-phenylenediox ) Diphthalic dianhydride and 4,4 '-(m-phenylenedioxy) diphthalic dianhydride, More preferably, 4,4'- oxydiphthalic dianhydride, 3,3', 4,4 '-Biphenyltetracarboxylic dianhydride (BPDA), 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA ), Bis (3,4-dicarboxyphenyl) methane dianhydride and 4,4 '-(p-phenylenedioxy) diphthalic dianhydride. These can be used individually or in combination of 2 or more types.

As aliphatic tetracarboxylic dianhydride, a cyclic or acyclic aliphatic tetracarboxylic dianhydride is mentioned. A cyclic aliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride which has an alicyclic hydrocarbon structure, As an example, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 1,2,3,4- Cycloalkanetetracarboxylic dianhydrides such as cyclobutanetetracarboxylic dianhydride, 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 positional isomers 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, 1,2,3,4-pentanetetracarboxylic dianhydride, and the like. Or it can use in combination of 2 or more type. Moreover, you may use combining a cyclic aliphatic tetracarboxylic dianhydride and an acyclic aliphatic tetracarboxylic dianhydride.

Among the tetracarboxylic dianhydrides, 4,4'-oxydiphthalic dianhydride, 3,3 ', 4,4', from the viewpoint of high surface hardness, high optical properties, high flexibility and high flex resistance of the optical film. -Benzophenonetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3, 3 ', 4,4'-diphenylsulfontetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic acid Dianhydrides, and mixtures thereof, are preferred, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride, And mixtures thereof are more preferred, and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA) This is more preferable.

As the dicarboxylic acid compound used for the synthesis of the polyimide resin or the polyamide resin, 4,4'-oxybisbenzoic acid and / or its acid chloride compound are preferably used. In addition to 4,4'-oxybisbenzoic acid or its acid chloride compound, other dicarboxylic acid compounds may be used. As another dicarboxylic acid compound, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, those acid chloride compounds of these, acid anhydride, etc. are mentioned, You may use in combination of 2 or more type. As a specific example, Terephthalic acid; Isophthalic acid; Naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; Dicarboxylic acid compound of a chain hydrocarbon having 8 or less carbon atoms and two benzoic acids connected by single bond, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO ₂ -or phenylene group A compound and those acid chloride compounds are mentioned. Among these other dicarboxylic acid compounds, terephthalic acid is preferable. As a specific example, 4,4'-oxybis (benzoyl chloride) and terephthaloyl chloride are preferable, and it is more preferable to use 4,4'-oxybis (benzoyl chloride) and terephthaloyl chloride in combination.

Moreover, in addition to the tetracarboxylic acid compound used for said polyimide-type resin synthesis | combination, a polyimide-type resin does not impair the various physical properties of an optical film, In addition, tetracarboxylic acid, tricarboxylic acid, and their anhydrides and derivatives are It may be reacted further.

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

As a tricarboxylic acid compound, aromatic tricarboxylic acid, aliphatic tricarboxylic acid, those flexible acid chloride compounds, an acid anhydride, etc. are mentioned, You may use in combination of 2 or more type. Specific examples include anhydrides of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalenetricarboxylic acid-2,3- anhydride; And phthalic anhydride and benzoic acid include a single bond, -O-, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO ₂ -or a phenylene group.

As a diamine compound used for the synthesis | combination of polyimide resin or polyamide resin, an aliphatic diamine, an aromatic diamine, and a mixture thereof are mentioned, for example. In addition, in this embodiment, "aromatic diamine" shows the diamine which the amino group couple | bonded with the aromatic ring directly, and may contain the aliphatic group or other substituent in a part of the structure. The aromatic ring may be monocyclic or condensed, and examples thereof include, but are not limited to, a benzene ring, a naphthalene ring, an anthracene ring and a fluorene ring. Among these, a benzene ring is preferable. Moreover, "aliphatic diamine" shows the diamine which the amino group couple | bonded with the aliphatic group directly, and may contain the aromatic ring and other substituents 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 diamine, 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 diamine having one aromatic ring, such as 6-diaminonaphthalene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3 , 4'-diaminodiphenylether, 3,3'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diamino Diphenylsulfone, 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 (may be referred to as TFMB), 4,4'-bis (4-a Nophenoxy) 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.

 As aromatic diamine, Preferably, 4,4'- diamino diphenylmethane, 4,4'- diamino diphenyl propane, 4,4'- diamino diphenyl ether, 3,3'- diamino diphenyl ether , 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 1,4-bis (4-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] Sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy ) Phenyl] propane, 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB), 4,4'-bis (4-aminophenoxy C) biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylether, 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'- (Trifluoromethyl) scan is 4,4'-diaminodiphenyl (TFMB), 4,4'- bis (4-aminophenoxy) biphenyl. These can be used individually or in combination of 2 or more types.

Among the said diamine compounds, it is preferable to use 1 or more types chosen from the group which consists of an aromatic diamine which has a biphenyl structure from a viewpoint of the high surface hardness, high optical characteristic, high flexibility, high bending resistance, etc. of an optical film. Consisting of 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine, 4,4'-bis (4-aminophenoxy) biphenyl and 4,4'-diaminodiphenylether It is more preferable to use 1 or more types selected from the group, and even more preferably to use 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB).

The polyamideimide which is one embodiment of the present invention includes a diamine compound, a tetracarboxylic acid compound (tetracarboxylic acid compound flexible body such as an acid chloride compound and a tetracarboxylic dianhydride), and a dicarboxylic acid compound (an acid chloride compound). Dicarboxylic acid compound flexible body) and, optionally, a tricondensation polymer which is a polycondensation product with a tricarboxylic acid compound (tricarboxylic acid compound flexible body such as an acid chloride compound or a tricarboxylic acid anhydride). The structural units represented by the formulas (1) and (30) are usually derived from diamines and tetracarboxylic acid compounds. The structural unit represented by Formula (2) is usually derived from a diamine and a dicarboxylic acid compound. The structural unit represented by Formula (31) is usually derived from a diamine and a tricarboxylic acid compound.

In a suitable embodiment of the present invention, a halogen atom may be included in the polyimide resin or polyamide resin having the structure (A) as described above. As a specific example of a fluorine-containing substituent, a fluoro group and a trifluoromethyl group are mentioned. When the polyimide-based resin or polyamide-based resin having the structure (A) contains a halogen atom, the flatness and optical properties of the optical film may be improved, and in particular, the yellowness (YI value) may be reduced. It tends to be compatible with high flexibility and flex resistance. In addition, the halogen atom is preferably a fluorine atom in view of the improvement in the flatness and optical properties of the optical film, in particular in the reduction of the yellowness, the reduction in the water absorption, and the bending resistance.

Content of the halogen atom in polyimide-type resin is preferable with respect to the mass of polyimide-type resin from a viewpoint of the improvement of the flatness and optical characteristics of an optical film, especially the fall of yellowness, the reduction of water absorption, and bending resistance. Preferably it is 1-40 mass%, More preferably, it is 3-35 mass%, More preferably, it is 5-32 mass%.

Although the reaction temperature of a diamine compound, a tetracarboxylic acid compound, and a dicarboxylic acid compound is not specifically limited, For example, it is 50-350 degreeC. Although reaction time is not specifically limited, for example, It is about 30 minutes-about 10 hours. If necessary, the reaction may be performed under inert atmosphere or reduced pressure. In addition, 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. 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-based 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 solvent can be used suitably from a soluble viewpoint.

In the imidation process in manufacture of polyimide-type resin, imidation can be carried out in presence of an imidation catalyst. As an imidation catalyst, For example, aliphatic amines, such as tripropylamine, dibutyl propylamine, and ethyl dibutyl amine; 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-picolin), 3-methylpyridine (3-picolin), 4-methylpyridine (4-picolin), 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 which is easy to promote the imidation reaction. Examples of the acid anhydride include conventional acid anhydrides used for imidization reactions, and specific examples thereof include aliphatic acid anhydrides such as acetic anhydride, propionic anhydride and butyric anhydride, and aromatic acid anhydrides such as phthalic acid.

The terminal amine of the obtained polyimide resin or polyamide resin is acetylated at a predetermined amount or more so as to satisfy the relationship of formula (X), thereby producing a polyimide resin or polyamide resin having a structure (A). can do. In the acetylation step of acetylating the terminal amine, the structure (A) is reacted by adding and reacting an acetylating agent such as acetic anhydride and acetyl chloride to a resin solution in which a polyimide resin or a polyamide resin is dissolved. The polyimide resin or polyamide resin which has is obtained. Although the reaction temperature of an acetylation process is not specifically limited, For example, it is 20-100 degreeC, Preferably it is 25-80 degreeC, Although reaction time is not specifically limited, For example, it is about 30 minutes-about 10 hours. If necessary, the reaction may be performed under inert atmosphere or reduced pressure. As a solvent, the solvent etc. which were illustrated above which can be used for manufacture of resin are mentioned, for example. In the polyimide resin or polyamide resin having the structure (A), for example, a large amount of methanol or the like is added to a reaction solution containing a polyimide resin or a polyamide resin to precipitate the resin, Isolation can be carried out by performing filtration, concentration, drying and the like.

The content of the acetylating agent can be appropriately selected depending on the value of A / B × 100 to be set. For example, preferably, 1 mole or more, and more preferably 3 mole or more, per 1 mole of the amine compound used for synthesis. More preferably, it is 7 mol or more, More preferably, it is 10 mol or more. When content of an acetylating agent is more than the said minimum, since the value of A / Bx100 can increase, gelation of resin is suppressed and it is easy to improve the flatness and optical characteristics of an optical film. In addition, the upper limit of content of an acetylating agent is although it does not specifically limit, Preferably it is 100 mol or less, More preferably, it is 50 mol or less.

<Additive>

The optical film of this invention can contain a filler. As a filler, organic particle | grains, an inorganic particle, etc. are mentioned, for example, Especially an inorganic particle is preferable. As inorganic particles, metal oxide particles such as silica, zirconia, alumina, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, cerium oxide, metals such as magnesium fluoride and sodium fluoride Fluoride particle etc. are mentioned, Among these, a silica particle, a zirconia particle, and an alumina particle are preferable from a viewpoint of easy to improve impact resistance, and a silica particle is especially preferable. These fillers can be used individually or in combination of 2 or more types.

The average primary particle diameter of the filler, preferably the silica particles, is preferably 10 nm or more, more preferably 15 nm or more, more preferably 20 nm or more, preferably 100 nm or less, and more preferably 90 Nm or less, more preferably 80 nm or less, even more preferably 70 nm or less, particularly preferably 60 nm or less, more particularly preferably 50 nm or less, and particularly preferably 40 nm or less. If the average primary particle diameter of a silica particle is the said range, aggregation of a silica particle will be suppressed and it will be easy to improve the optical characteristic of an optical film. An average primary particle diameter can be measured by a BET method. Moreover, you may measure an average primary particle diameter by the image analysis of a transmission electron microscope (TEM) and a scanning electron microscope (SEM).

When the optical film contains a filler, preferably silica particles, the content of the filler, preferably the silica particles, is usually 0.1 parts by mass or more, preferably 1 part by mass or more, based on 100 parts by mass of the optical film. Preferably it is 5 mass parts or more, More preferably, it is 10 mass parts or more, Especially preferably, it is 20 mass parts or more, Especially 30 mass parts or more, Preferably it is 60 mass parts or less. If content of a filler is more than the said minimum, it will be easy to improve an elasticity modulus. Moreover, when content of a filler is below the said upper limit, it is easy to suppress gelatinization and it is easy to improve the flatness and optical characteristics of an optical film.

The optical film of this invention may contain the ultraviolet absorber further. A ultraviolet absorber can be suitably selected from what is normally used as a ultraviolet absorber in the field of a resin material. The ultraviolet absorber may contain the compound which absorbs the light of the wavelength of 400 nm or less. As a ultraviolet absorber, the at least 1 sort (s) of compound chosen from the group which consists of a benzophenone type compound, a salicylate type compound, a benzotriazole type compound, and a triazine type compound is mentioned, for example. A ultraviolet absorber can be used individually or in combination of 2 or more types. Since an optical film contains a ultraviolet absorber, deterioration of resin is suppressed, and when visibility is applied to an image display apparatus etc., visibility can be improved. In the present specification, the "based compound" refers to a derivative of the compound to which the "based compound" is attached. For example, a "benzophenone type compound" refers to a compound having a benzophenone as a parent skeleton and a substituent bonded to benzophenone.

When an optical film contains a ultraviolet absorber, content of a ultraviolet absorber becomes like this. Preferably it is 1 mass part or more, More preferably, it is 2 mass parts or more, More preferably, it is 3 mass parts or more with respect to 100 mass parts of optical films. Preferably it is 10 mass parts or less, More preferably, it is 8 mass parts or less, More preferably, it is 6 mass parts or less. Although suitable content differs according to the ultraviolet absorber to be used, if content of a ultraviolet absorber is adjusted so that the light transmittance of 400 nm may be about 20 to 60%, the light resistance of an optical film will become high and an optical film with high transparency can be obtained. .

The optical film may further contain other additives other than a filler and a ultraviolet absorber. As another additive, antioxidant, a mold release agent, a stabilizer, a bluing agent, a flame retardant, a pH adjuster, a silica dispersing agent, a lubricating agent, a thickener, a leveling agent, etc. are mentioned, for example. When it contains another additive, the content is 0.005-20 mass parts with respect to 100 mass parts of optical films, More preferably, it is 0.01-15 mass parts, More preferably, it is 0.1-10 mass parts.

<Optical film>

Since the optical film of this invention has resin which satisfy | fills the relationship of Formula (X), the nonuniformity of a partial thickness is small and can have the outstanding flatness of a film surface. Moreover, since the optical film of this invention also has the outstanding optical characteristic, excellent surface flatness and excellent optical characteristic can be compatible.

Although the thickness of the optical film of this invention is adjusted suitably according to a use, Preferably it is 25 micrometers or more, More preferably, it is 27 micrometers or more, More preferably, it is 30 micrometers or more, Preferably it is 100 micrometers or less, More preferably, Is 80 µm or less, more preferably 65 µm or less, particularly preferably 55 µm or less. The thickness of an optical film can be measured with a film thickness meter, etc., and can be measured by the method as described in an Example, for example.

In the optical film of the present invention, the total light transmittance at a thickness of 48 to 52 µm, preferably 50 µm is preferably 80% or more, more preferably 85% or more, even more preferably 90% or more, Especially preferably, it is 91% or more. Transparency becomes favorable that a total light transmittance is more than the said minimum, and when it is used for the front plate of an image display apparatus, for example, it can contribute to high visibility. In addition, the upper limit of total light transmittance is 100% or less normally. In addition, total light transmittance can be measured using a haze computer based on JISK736-1: 1997, for example, and can be measured by the method as described in an Example, for example.

Haze of the optical film of this invention becomes like this. Preferably it is 3.0% or less, More preferably, it is 2.0% or less, More preferably, it is 1.0% or less, Especially preferably, it is 0.5% or less. If the haze of an optical film is below the said upper limit, transparency will become favorable, and when used for the front plate of an image display apparatus, for example, it can contribute to high visibility. In addition, the minimum of haze is 0.01% or more normally. In addition, a haze can be measured using a haze computer based on JISK7136: 2000, For example, it can measure by the method as described in an Example.

Yellowness (YI value) of the optical film of this invention becomes like this. Preferably it is 8 or less, More preferably, it is 5 or less, More preferably, it is 3 or less, Especially preferably, it is 2 or less. If the yellowness of an optical film is below the said upper limit, transparency will become favorable, and when used for the front plate of an image display apparatus, for example, it can contribute to high visibility. In addition, yellowness is -5 or more normally, Preferably it is -2 or more. In addition, the yellowness (YI value) is measured using a UV-visible near-infrared spectrophotometer to measure the transmittance of light at 300 to 800 nm, to obtain three stimulus values (X, Y, Z), and YI = 100 × (1.2769). It can calculate based on the formula of X-1.0592Z) / Y.

[Method of Manufacturing Optical Film]

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

(a) step (varnish preparation step) of preparing the liquid (which may be called resin varnish) containing the said resin,

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

(c) Process of drying the apply | coated liquid (coating film) and forming an optical film (film formation process)

It can manufacture by the method containing these.

In the varnish preparation step, the resin varnish is prepared by dissolving the above resin in a solvent and, if necessary, adding a filler, a ultraviolet absorber, other additives and the like and stirring the mixture.

The solvent used for preparation of the varnish is not particularly limited as long as it can dissolve the resin. As such a solvent, the solvent etc. which were illustrated in the term of <manufacturing method of resin> are mentioned, for example. Among these solvents, an amide solvent or a lactone solvent can be suitably used. Such solvents may be used alone or in combination of two or more thereof. Solid content concentration of resin varnish becomes like this. Preferably it is 1-25 mass%, More preferably, it is 5-15 mass%.

In a coating process, a resin 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, a roll coating method such as wire bar coating method, reverse coating, gravure coating, die coating method, comma coating method, lip coating method, spin coating method, screen coating method, fountain coating method, D A ping method, a spray method, the casting molding method, etc. are mentioned.

In a film formation process, an optical film can be formed by drying a coating film and peeling from a support material. You may provide the process of drying an optical film further after peeling. Drying of a coating film can be performed at the temperature of 50-350 degreeC normally. As needed, you may dry a coating film under the conditions of inert atmosphere or reduced pressure.

Examples of the support material include metal belts such as SUS, and resin films such as PET films, PEN films, other polyimide films, polyamide films, and polyamideimide films. Especially, PET film, PEN film, etc. are preferable from a viewpoint of excellent heat resistance, and PET film is more preferable from a viewpoint of adhesiveness, peeling property, and cost at the time of film-forming with an optical film.

[Optical resin]

The present invention is formula (A)

[Formula 21]

[In formula (A), * represents a bond.]

As optical resin containing at least 1 sort (s) chosen from the group which consists of polyimide-type resin and polyamide-type resin which have a structure represented by the formula (X)

A / B × 100≥0.03 (%) (X)

[In Formula (X), A represents the peak area derived from the hydrogen atom couple | bonded with the nitrogen atom in the structure represented by Formula (A) in <^1> H-NMR spectrum of the said optical resin, B is In the ¹ H-NMR spectrum of the optical resin, a chemical shift value represents a peak area in a range of 6.5 to 11.5 ppm.]

Optical resin represented by this is included.

The optical resin of the present invention satisfies the relationship of the formula (X), that is, since A / B × 100 has a predetermined amount or more of the structure (A) as 0.03% or more, an optical film containing the resin is formed. In this case, the gelation of the resin varnish can be effectively suppressed. Therefore, the nonuniformity of a partial thickness is small and the optical film excellent in the flatness of a film surface can be formed. Moreover, since the mixing of a gel is suppressed, the optical film obtained can also express the outstanding optical characteristic.

It is preferable that the optical resin of this invention is polyimide-type resin and / or polyamide-type resin as described in said <resin>.

[Optical laminated body]

The optical film of this invention may be a single | mono layer, a laminated body may be sufficient, an optical film may be used as it is, and may also be used as a laminated body with another film or layer. In this invention, when an optical film is a laminated body, it is called an optical film including all the layers laminated | stacked on the single side | surface or both surfaces of an optical film. In addition, the optical film of a laminated body form may be called an optical laminated body (or laminated body) for convenience.

An optical laminated body can also be formed by laminating | stacking one or more functional layers on at least one surface of the optical film of this invention. As a functional layer, an ultraviolet absorber 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 is, for example, a main material selected from an ultraviolet curable transparent resin, an electron beam curable transparent resin, and a thermosetting transparent resin, and dispersed in the main material. It consists of an ultraviolet absorber.

An adhesive layer is a layer which has a sticky function, and has a function which adhere | attaches an optical film to another member. As a formation material of an adhesion layer, a conventionally well-known thing 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 adhered to the object by pressure, called a pressure sensitive adhesive (PSA). The pressure-sensitive adhesive may be an adhesive, which is "a substance which has adhesiveness at room temperature and adheres to the adherend at light pressure" (JIS K 6800), and "contains a specific component in a protective film (microcapsule), and adopts suitable means (pressure Or an adhesive capable of holding stability until the film is destroyed by heat, or the like '' (JIS K 6800).

A color adjustment layer is a layer which has a function of color adjustment, and is a layer which can adjust an optical laminated body to the target color. A color adjustment layer is a layer containing resin and a coloring agent, for example. As this coloring agent, For example, Inorganic pigments, such as a titanium oxide, zinc oxide, a bengalah, a titanium oxide type baking pigment, 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, styrene compounds, and diketopyrrolopyrrole compounds; Extender pigments such as barium sulfate and calcium carbonate; And dyes such as basic dyes, acid dyes, and mordant dyes.

A refractive index adjustment layer is a layer which has a function of refractive index adjustment, and is a layer which has a refractive index different from an optical film, and can give a predetermined refractive index to an optical laminated body, for example. The refractive index adjusting layer may be, for example, a resin that is appropriately selected, and a resin layer further containing a pigment as the case may be, or a thin film of metal. Examples of the pigment for adjusting the refractive index include silicon oxide, aluminum oxide, antimony oxide, tin oxide, titanium oxide, zirconium oxide and tantalum oxide. The average primary particle diameter of the said pigment may be 0.1 micrometer or less. By making the average primary particle diameter of a pigment into 0.1 micrometer or less, the diffuse reflection of the light which permeate | transmits a refractive index adjustment layer can be prevented, and the fall of 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. Metal nitrides.

The optical laminated body may further contain the protective film. The protective film may be laminated on one side or both sides of the optical film. When having a functional layer in the single side | surface of an optical film, a protective film may be laminated | stacked on the surface of the optical film side, or the surface of the functional layer side, and may be laminated | stacked on both an optical film side and a functional layer side. When it has a functional layer on both surfaces of an optical film, a protective film may be laminated | stacked on the surface of one functional layer side, and may be laminated | stacked on the surface of both functional layer sides. A protective film is a film for temporarily protecting the surface of an optical film or a functional layer, and it is not specifically limited as long as it is a peelable film which can protect the surface of an optical film or a functional layer. As a protective film, For example, Polyester-based resin films, such as polyethylene terephthalate, a polybutylene terephthalate, a polyethylene naphthalate; Polyolefin resin films, such as polyethylene and a polypropylene film, an acrylic resin film, etc. are mentioned, It is preferable to select from the group which consists of a polyolefin resin film, a polyethylene terephthalate resin film, and an acrylic resin film. When an optical laminated body has two protective films, each protective film may be same or different.

Although the thickness of a protective film is not specifically limited, Usually, 10-100 micrometers, Preferably it is 10-80 micrometers, More preferably, it is 10-50 micrometers. When an optical laminated body has two protective films, the thickness of each protective film may be the same and may differ.

In one embodiment of the present invention, the optical laminated body may be a form wound in a roll shape in a core, and the form is referred to as a laminate film roll. Examples of the material constituting the core include polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyester resin, epoxy resin, phenol resin, melamine resin, silicon resin, polyurethane resin, polycarbonate resin and ABS resin. Synthetic resins; Metals such as aluminum; Fiber-reinforced plastics (FRP: composite material in which fibers such as glass fibers are contained in plastics to improve strength); The core forms a shape such as a cylindrical shape or a cylindrical shape, and the diameter thereof is, for example, 80 to 170 mm. In addition, the diameter (diameter after winding) of a laminated body film roll is although it does not specifically limit, Usually, it is 200-800 mm. In one embodiment of the present invention, the laminate film roll, in the manufacturing process of the optical film, the laminate having a support material, an optical film and optionally a functional layer and a protective film, without peeling the support material from the optical film, You may have the form wound by the core in roll shape. In the case of continuous manufacture, the laminated film roll is often stored in the form of a film roll once from space and other constraints, and in the form of the laminated film roll, the laminated body is wound more tightly, so that the cloudy on the support material The causative agent tends to be transferred onto the optical film. However, when a support material having a predetermined logarithmic contact angle is used, the clouding material from the support material is less likely to be transferred to the substrate, and even if it is wound around the laminate film roll, clouding is unlikely to occur.

[Image display device]

Since the optical film of this invention has the outstanding surface flatness and optical characteristics, it can be used suitably as a front plate (window film) of an image display apparatus. The optical film of this invention can be arrange | positioned as a front plate in the visual recognition side surface of an image display apparatus, especially a flexible display (flexible display apparatus). The front panel has a function of protecting an image display element in the flexible display. As an image display apparatus, wearable devices, such as a television, a smartphone, a mobile telephone, car navigation, a tablet PC, a portable game machine, an electronic paper, an indicator, a bulletin board, a clock, and a smart watch, are mentioned. As a flexible display, the image display apparatus which has a flexible characteristic, for example, a television, a smart phone, a mobile phone, a smart watch, etc. are mentioned. Therefore, this invention includes the flexible display apparatus provided with the said optical film. In addition, the optical film of this invention may be called a window film below.

In one embodiment of the present invention, the image display device, particularly the flexible display device, may include at least one selected from the group consisting of the optical film of the present invention and a polarizing plate, a touch sensor, and a display panel. For example, the image display apparatus in which the polarizing plate, the touch sensor, and the display panel were laminated | stacked without the transparent adhesive agent or the transparent adhesive agent on the single side | surface of the said optical film may be sufficient. In addition, the optical film of this invention may be contained in the image display apparatus as said optical laminated body, and the said optical laminated body may be sufficient as the optical film contained in an image display apparatus below.

In one embodiment of the present invention, the image display device may include a colored light shielding pattern printed by enclosing a frame on at least one surface of the optical film or the polarizing plate, and the light shielding pattern may be a single layer or a multilayer. do. The polarizing plate may extend continuously over the non-display area or the bezel portion, and includes a protective layer laminated (or bonded) to at least one surface of the polyvinyl alcohol polarizer and the polyvinyl alcohol polarizer. A normal polarizing plate may be sufficient.

In one embodiment of the present invention, in a structure in which a polarizing plate and a touch sensor are integrated on one surface of the optical film, the arrangement order of the polarizing plate and the touch sensor is not limited, and in order of the optical film, the polarizing plate, the touch sensor, and the display panel. You may arrange | position, and it may arrange | position in order of an optical film, a touch sensor, a polarizing plate, and a display panel. When arrange | positioning in order of an optical film, a polarizing plate, a touch sensor, and a display panel, since the touch sensor exists in the lower side of a polarizing plate when an image display apparatus is seen from the visual recognition side, there exists an advantage that the pattern of a touch sensor is hard to be recognized. In such a case, it is preferable that the front phase difference of the board | substrate of a touch sensor is ± 2.5 nm or less. As a raw material of the said board | substrate, it is an unstretched film, For example, even if it is a film of 1 or more material chosen from the group which consists of materials, such as a triacetyl cellulose, a triacetyl cellulose, a cycloolefin, a cycloolefin copolymer, a polynorbornene copolymer, do. Meanwhile, only the pattern without the substrate of the touch sensor may have a structure transferred to the optical film and the polarizing plate.

Although the said polarizing plate and a touch sensor can be arrange | positioned between an optical film and a display panel with a transparent adhesive layer or a transparent adhesive bond layer, a transparent adhesive layer is suitable. When arrange | positioned in order of an optical film, a polarizing plate, a touch sensor, and a display panel, a transparent adhesive layer may be located between an optical film and a polarizing plate, and between a touch sensor and a display panel. When arrange | positioned in order of an optical film, a touch sensor, a polarizing plate, and a display panel, a transparent adhesive layer may be located between an optical film and a touch sensor, between a touch sensor and a polarizing plate, a polarizing plate, and a display panel.

The thickness of the said transparent adhesive layer is not specifically limited, For example, 1-100 micrometers may be sufficient. In the said transparent adhesive layer, it is preferable that the thickness of the transparent adhesive layer of a lower part (display panel side) is more than the thickness of the transparent adhesive layer of an upper part (optical film side), and viscoelasticity is 0.2 Mpa or less at -20-80 degreeC. In this case, noise generated by the interference between the touch sensor and the display panel can be reduced, and the interfacial stress during bending can be alleviated to prevent breakage of other functional layers in the upper and lower parts. More preferably, the viscoelasticity may be 0.01 to 0.15 MPa in terms of suppressing cohesive failure of the transparent pressure-sensitive adhesive and at the same time relieving interfacial stress.

<Polarizing plate>

The said image display apparatus, especially the flexible display apparatus may be equipped with the polarizing plate as mentioned above. For example, the polarizing plate may include at least one selected from a polarizer and a support, an alignment film, a retardation coating layer, an adhesive layer, an adhesive layer, and a protective layer, as necessary. The thickness of the said polarizing plate is not specifically limited, For example, 100 micrometers or less may be sufficient. If thickness is 100 micrometers or less, flexibility will hardly fall. 5-100 micrometers may be sufficient, for example within the said range.

The polarizer may be a film polarizer commonly used in the art prepared by a process including the steps of swelling, dyeing, crosslinking, stretching, washing with water, drying, and the like, and polymerizable liquid crystal and dichroic polyvinyl alcohol-based film. An application type polarizer (sometimes called a polarization coating layer) formed by apply | coating the polarizing coating layer forming composition containing a soluble dye may be sufficient. The polarizing coating layer (sometimes referred to simply as polarizing layer) may, for example, apply an alignment film forming composition on a support, impart orientation to form an alignment film, and form a polymerizable liquid crystal compound and a dichroic dye on the alignment film. It can manufacture by apply | coating the polarizing coating layer forming composition containing and forming a liquid crystal coating layer. Such a polarizing coating layer can form thin thickness compared with the polarizing plate containing the protective layer affixed on both surfaces of a film-type polarizer with an adhesive agent. The thickness of the polarizing coating layer may be 0.5 to 10 µm, preferably 2 to 4 µm.

(Alignment film)

The alignment film can be formed by applying the alignment film forming composition. An alignment film formation composition may contain the alignment agent, photoinitiator, and solvent which are used normally in the said field | area. As the aligning agent, an aligning agent usually used in the art can be used without particular limitation. For example, a polyacrylate-based polymer, a polyamic acid, a polyimide-based polymer, or a polymer containing cinnamate groups can be used as the alignment agent, and when a photoalignment is applied, it is preferable to use a polymer containing cinnamate groups. Do. Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether, ethyl acetate, butyl acetate and ethylene glycol methyl ether. Ester solvents such as acetate, γ-butyrolactone, propylene glycol methyl ether acetate, ethyl lactate, ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, methyl isobutyl ketone, pentane, Aliphatic hydrocarbon solvents such as hexane and heptane, aromatic hydrocarbon solvents such as toluene and xylene, nitrile solvents such as acetonitrile, ether solvents such as tetrahydrofuran and dimethoxyethane, and chlorinated hydrocarbon solvents such as chloroform and chlorobenzene. Can be mentioned. A solvent can be used individually or in combination of 2 or more types.

Examples of the coating of the alignment layer forming composition include spin coating, extrusion molding, dip coating, flow coating, spray coating, roll coating, gravure coating, micro gravure coating, and the like. use. After the said alignment film formation composition is apply | coated and dried as needed, an orientation treatment is performed. The above-mentioned orientation treatment can employ | adopt various well-known methods in the said field | area without limitation, Preferably, photo-alignment film formation can be used. A photo-alignment film is obtained by apply | coating the composition for photo-alignment film formation containing the polymer or monomer which has a photoreactive group, and a solvent to a support body normally, and irradiating polarized light (preferably polarized UV). The photo-alignment film is more preferable at the point which can arbitrarily control the direction of the orientation regulation force by selecting the polarization direction of the polarized light to irradiate.

The thickness of the photo-alignment film is usually 10 to 10,000 nm, preferably 10 to 1,000 nm, and more preferably 10 to 500 nm. When it is in the said range, an orientation regulation force will fully express.

(Polarization coating layer)

The polarizing coating layer may be formed by applying a polarizing coating layer forming composition. Specifically, the polarizing coating layer-forming composition is a composition containing one or more polymerizable liquid crystals (hereinafter, sometimes referred to as polymerizable liquid crystals (B)) which become a host compound in addition to a dichroic dye (hereinafter, referred to as composition B). Is).

A "dichroic dye" means the pigment | dye which has the property which the absorbance in the major axis direction of a molecule | numerator differs from the absorbance in a short axis direction. As long as it has such a property, a dichroic dye does not have a restriction | limiting and may be a dye and a pigment may be sufficient as it. Two or more types of dyes may be used in combination, two or more types of pigments may be used in combination, and dyes and pigments may be used in combination.

It is preferable that a dichroic dye has maximum absorption wavelength ((lambda) _MAX ) in the range of 300-700 nm. As such a dichroic dye, an acridine pigment, an oxazine pigment, a cyanine pigment, a naphthalene pigment, an azo pigment, and an anthraquinone pigment is mentioned, Especially, an azo pigment is preferable. As an azo dye, a monoazo pigment | dye, a bis azo pigment | dye, a tris azo pigment | dye, a tetrakis azo pigment | dye, and a stilbene azo pigment | dye are mentioned, A bis azo pigment | dye and a tris azo pigment | dye are preferable.

It is preferable that it is a smectic phase, and, as for the liquid crystal state represented by a polymeric liquid crystal (B), it is more preferable that it is a higher order smectic phase from the point which can manufacture a polarizing layer with a higher degree of orientation order. The polymerizable liquid crystal (B) showing a smectic phase is called a polymerizable smectic liquid crystal compound. The polymerizable liquid crystal (B) can be used alone or in combination. Moreover, when combining 2 or more types of polymerizable liquid crystals, it is preferable that at least 1 type is a polymerizable liquid crystal (B), and it is more preferable that 2 or more types are polymerizable liquid crystals (B). By combining these, liquid crystallinity may be temporarily retained even at a temperature below the liquid crystal-crystal phase transition temperature. The polymerizable liquid crystal (B) is, for example, Lub et al. Recl. Trav. Chim. It is manufactured by the well-known method described in Pays-Bas, 115, 321-328 (1996) or Japanese Patent No. 4719156. Although content of the dichroic dye in the composition B can be adjusted suitably according to the kind of dichroic dye, etc., Preferably it is 0.1-50 mass parts with respect to 100 mass parts of polymerizable liquid crystals (B), More preferably, it is 0.1- 20 mass parts, More preferably, it is 0.1-10 mass parts. When content of a dichroic dye is in the said range, it can superpose | polymerize without disperse | distributing the orientation of a polymeric liquid crystal (B), and the tendency which inhibits the orientation of a polymeric liquid crystal (B) is small.

It is preferable that composition B contains a solvent. Generally, since a smectic liquid crystal compound has a high viscosity, the composition containing a solvent is easy to apply | coat, and as a result, it is easy to form a polarizing film in many cases. As a solvent, the thing similar to the solvent contained in the orientation polymer composition mentioned above can be mentioned, It can select suitably according to the solubility of a polymeric liquid crystal (B) and a dichroic dye. Content of a solvent becomes like this. Preferably it is 50-98 mass% with respect to the total amount of the composition B. If it reduces, solid content in the composition B becomes like this. Preferably it is 2-50 mass%.

It is preferable that composition B contains at least 1 leveling agent. The leveling agent has a function of adjusting the fluidity of the composition B to make the coating film obtained by applying the composition B more flat, and specifically, a surfactant may be mentioned. When composition B contains a leveling agent, its content becomes like this. Preferably it is 0.05-5 mass parts, More preferably, it is 0.05-3 mass parts with respect to 100 mass parts of polymeric liquid crystals. When content of a leveling agent exists in the said range, it is easy to horizontally align a polymeric liquid crystal, and there exists a tendency for the polarizing layer obtained to become smoother. When content of the leveling agent with respect to a polymerizable liquid crystal exists in the said range, there exists a tendency for a stain to not generate | occur | produce so much in the polarizing layer obtained.

It is preferable that composition B contains 1 or more types of polymerization initiators. A polymerization initiator is a compound which can start the polymerization reaction of a polymeric liquid crystal (B), and a photoinitiator is preferable at the point which can start a polymerization reaction on lower temperature conditions. Specifically, the photoinitiator which can generate | occur | produce an active radical or an acid by the action of light is mentioned, Especially the photoinitiator which generate | occur | produces a radical by the action of light is preferable. Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts and sulfonium salts.

When composition B contains a polymerization initiator, although the content can be suitably adjusted according to the kind and quantity of the polymeric liquid crystal contained in the composition, It is 0.1-30 mass with respect to 100 mass parts of polymeric liquid crystals preferably. Part, More preferably, it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts. When content of a polymerization initiator exists in this range, it can superpose | polymerize without disturbing the orientation of a polymeric liquid crystal (B). When composition B contains a photoinitiator, the said composition may further contain the photosensitizer. When composition B contains a photoinitiator and a photosensitizer, the polymerization reaction of the polymeric liquid crystal contained in this composition can be accelerate | stimulated more. Although the usage-amount of a photosensitizer can be suitably adjusted according to the kind and quantity of a photoinitiator and a polymeric liquid crystal, Preferably it is 0.1-30 mass parts with respect to 100 mass parts of polymeric liquid crystals, More preferably, it is 0.5-10 mass Part, More preferably, it is 0.5-8 mass parts.

In order to advance the polymerization reaction of a polymerizable liquid crystal more stably, the composition B may contain a suitable amount of a polymerization inhibitor, and thereby, it becomes easy to control the progress of the polymerization reaction of a polymerizable liquid crystal. When composition B contains a polymerization inhibitor, the content can be suitably adjusted according to the kind and quantity of a polymeric liquid crystal, the usage-amount of a photosensitizer, etc., However, Preferably it is 0.1 with respect to 100 mass parts of polymeric liquid crystals. It is -30 mass parts, More preferably, it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts. If content of a polymerization inhibitor is in this range, it can superpose | polymerize without disturbing the orientation of a polymeric liquid crystal.

A polarizing coating layer is normally formed by apply | coating a polarizing coating layer forming composition on the support body on which the orientation process was performed, and polymerizing the polymerizable liquid crystal in the obtained coating film. The method of apply | coating the said polarizing coating layer forming composition is not limited. Examples of the orientation treatment include those exemplified above. A dry film is formed by apply | coating a polarizing coating layer forming composition and drying-drying a solvent on the conditions which the polymerizable liquid crystal contained in the obtained coating film does not superpose | polymerize. As a drying method, a natural drying method, ventilation drying method, heat drying, and reduced pressure drying method are mentioned. When a polymeric liquid crystal is a polymeric smectic liquid crystal compound, it is preferable to make the liquid crystal state of the polymeric smectic liquid crystal compound contained in a dry film into a nematic phase (nematic liquid crystal state), and then transfer to a smectic phase. In order to form a smectic phase via a nematic phase, for example, the polymerizable smectic liquid crystal compound contained in the dry coating is heated to a temperature above the temperature at which the phase transitions into the liquid crystal state of the nematic phase, and then the polymerizable The method by which the smectic liquid crystal compound is cooled to the temperature which shows the liquid crystal state of a smectic phase is employ | adopted. Subsequently, after making the liquid crystal state of the polymeric liquid crystal in a dry film into a smectic phase, the method of photopolymerizing a polymeric liquid crystal is demonstrated, maintaining the smectic phase liquid crystal state. In photopolymerization, the light irradiated to a dry film can be suitably selected according to the kind of photoinitiator contained in the said dry film, the kind of polymeric liquid crystal (especially the kind of photopolymerizer which a polymeric liquid crystal has), and its quantity. Specific examples thereof include an active energy ray selected from the group consisting of visible light, ultraviolet light and laser light. Among these, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction, and in that it can be used widely in the art as a photopolymerization apparatus. By performing photopolymerization, the polymerizable liquid crystal is polymerized while maintaining a liquid crystal state of a smectic phase, preferably a higher order smectic phase, thereby forming a polarizing layer.

(Phase difference coating layer)

The polarizing plate may include a phase difference coating layer (sometimes referred to simply as a phase difference layer). The retardation layer is generically referred to as λ / 2 layer, λ / 4 layer, positive C layer, or the like depending on the optical characteristics. The retardation layer is, for example, after applying the retardation layer forming composition containing a liquid crystal compound on the alignment film of the support having the alignment film formed on the surface to form a liquid crystal coating layer, the liquid crystal coating layer is affixed to the polarizing layer via the adhesive layer. Although it can form by peeling a support body after doing this, it is not limited to this method. The surface of the support on the side where the alignment film and the retardation layer are formed may be subjected to surface treatment before the alignment film is formed. The said orientation film formation composition, its application | coating, drying method, etc. are the same as what was demonstrated by the polarizing coating layer. The composition of the retardation layer forming composition is the same as that described in the polarizing coating layer, except that the dichroic dye is not included. Moreover, the application | coating, drying, hardening method, etc. of retardation layer forming composition are also the same as what was demonstrated by the said polarizing coating layer.

The thickness of the retardation layer is preferably 0.5 to 10 µm, more preferably 1 to 4 µm.

In one Embodiment of this invention, a retardation layer can adjust an optical characteristic according to the thickness, the orientation state of a polymeric liquid crystal compound, etc. Specifically, by adjusting the thickness of the retardation layer, a retardation layer that gives a desired in-plane retardation can be produced. The in-plane retardation value (in-plane retardation value, Re) is a value defined by Formula (1), and what is necessary is just to adjust (DELTA) n and thickness d to obtain desired Re.

Re = d × Δn (λ) ... (1) (where Δn = nx-ny)

(In Formula (1), Re represents the in-plane retardation value of the retardation layer, d represents the thickness of the retardation layer, and Δn represents the birefringence of the retardation layer.) An index ellipsoid formed by the orientation of the polymerizable liquid crystal compound. In consideration of the above, the refractive indices in three directions, that is, nx, ny, and nz are defined as follows: nx denotes a main refractive index in a direction parallel to the plane of the phase difference layer in the refractive index ellipsoid formed by the phase difference layer. ny represents the refractive index of the direction parallel to the said retardation layer plane in the refractive index ellipsoid which a retardation layer forms, and orthogonal to the direction of nx.nz is the said retardation layer plane in the refractive index ellipsoid which a retardation layer forms. When the phase difference layer is λ / 4 layer, the in-plane retardation value Re (550) is usually in the range of 113 to 163 nm, preferably 130 to 150 nm. The above. When the retardation layer is a λ / 4 layer, Re (550) is in the range of usually 250~300㎚.

Moreover, the phase difference layer which expresses the phase difference of the thickness direction can be produced according to the orientation state of a polymeric liquid crystal compound. Expressing the phase difference in the thickness direction indicates a characteristic in which the phase difference value Rth in the thickness direction becomes negative in Equation (2).

Rth = [(nx + ny) / 2-nz] × d ... (2)

(In formula (2), nx, ny, nz, and d are the same as the definition of the above.)

The in-plane retardation value Re (550) of the positive C layer is usually in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm, and the phase difference value Rth in the thickness direction is usually -10 to-. It is the range of 300 nm, Preferably it is the range of -20-200 nm. The polarizing plate may have two or more retardation layers, and when it has two retardation layers, a 1st retardation layer is (lambda) / 4 layer for making circularly polarized light, and a 2nd retardation layer is positive C for improving the hue seen obliquely. It may be a layer. Further, the first retardation layer may be a positive C layer for improving the color tone seen at an angle, and the second retardation layer may be a λ / 4 layer for producing circularly polarized light.

(Adhesive Layer and Adhesive Layer)

The polarizing plate may include an adhesive layer and / or an adhesive layer. In one Embodiment of this invention, a polarizing coating layer and a 1st phase difference layer, or a 1st phase difference layer and a 2nd phase difference layer can be bonded together via an adhesive or an adhesive agent. As an adhesive agent which forms an adhesive bond layer, an aqueous adhesive agent, an active energy ray curable adhesive agent, or a thermosetting adhesive agent can be used, Preferably it is an aqueous adhesive agent and an active energy ray curable adhesive agent. As an adhesive layer, the thing mentioned later can be used.

As an aqueous adhesive agent, the adhesive agent which consists of polyvinyl alcohol-type resin aqueous solution, an aqueous two-component urethane emulsion adhesive, etc. are mentioned. Especially, the aqueous adhesive which consists of aqueous solution of polyvinyl alcohol-type resin is used suitably. As polyvinyl alcohol-type resin, the polyvinyl alcohol-type copolymer obtained by saponifying the copolymer of vinyl acetate and the other monomer copolymerizable with this besides the vinyl alcohol homopolymer obtained by saponifying the polyvinyl acetate which is a homopolymer of vinyl acetate. Or modified polyvinyl alcohol polymers obtained by partially modifying their hydroxyl groups. The aqueous adhesive may include a crosslinking agent such as an aldehyde compound (glyoxal, etc.), an epoxy compound, a melamine compound, a methylol compound, an isocyanate compound, an amine compound, a polyvalent metal salt, and the like.

When using an aqueous adhesive agent, after bonding a coating layer, it is preferable to perform the drying process for removing the water contained in an aqueous adhesive agent.

The said active energy ray curable adhesive agent is an adhesive agent containing the curable compound hardened | cured by irradiation of active energy rays, such as an ultraviolet-ray, visible light, an electron beam, and an X-ray, Preferably it is an ultraviolet curable adhesive agent.

The curable compound may be a cation polymerizable curable compound or a radical polymerizable curable compound. As a cationic polymerizable curable compound, For example, an epoxy type compound (compound which has 1 or 2 or more epoxy groups in a molecule), an oxetane type compound (compound which has 1 or 2 or more oxetane rings in a molecule), or A combination of these. As a radically polymerizable curable compound, it is a (meth) acrylic-type compound (compound which has 1 or 2 or more (meth) acryloyloxy groups in a molecule | numerator), or other vinyl type compound which has a radically polymerizable double bond, for example. Or a combination thereof. You may use together a cationically polymerizable curable compound and a radically polymerizable curable compound. The active energy ray curable adhesive usually further contains a cationic polymerization initiator and / or a radical polymerization initiator for initiating the curing reaction of the curable compound.

In bonding a coating layer, in order to improve adhesiveness, you may surface-treat at least any one bonding surface of the surface to adhere | attach. As the surface activation treatment, dry treatment such as corona treatment, plasma treatment, discharge treatment (glow discharge treatment, etc.), flame treatment, ozone treatment, UV ozone treatment, ionizing active line treatment (ultraviolet treatment, electron beam treatment, etc.); And wet treatments such as ultrasonic treatment using a solvent such as water or acetone, saponification treatment, and anchor coating treatment. These surface activation processes may be performed independently, or may combine 2 or more.

The thickness of the said adhesive layer can be adjusted according to the adhesive force, Preferably it is 0.1-10 micrometers, More preferably, it may be 1-5 micrometers. In one embodiment of the present invention, in the case of a configuration in which a plurality of the adhesive layers are used, they may be made of the same material or of different materials, and may have the same thickness or different thicknesses.

An adhesive layer can be comprised by the adhesive composition which has resin, such as (meth) acrylic-type resin, rubber type resin, polyurethane type resin, polyester type resin, silicone type resin, and polyvinyl ether type resin as a main component. Especially, the adhesive composition which uses polyester resin or (meth) acrylic-type resin which is excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is suitable. An active energy ray hardening type and a thermosetting type may be sufficient as an adhesive composition.

As adhesive resin used by this invention, the thing of the range of 300,000-4 million in weight average molecular weight is used normally. When durability, especially heat resistance are considered, the weight average molecular weight of the said adhesive becomes like this. Preferably it is 500,000-3 million, More preferably, it is 650,000-2 million. When a weight average molecular weight is larger than 300,000, it is preferable at the point of heat resistance, and when a weight average molecular weight is smaller than 4 million, it is also preferable at the point where adhesiveness and adhesive force fall. In addition, a weight average molecular weight is measured by GPC (gel permeation chromatography) and says the value computed by polystyrene conversion.

Moreover, a crosslinking agent can be contained in an adhesive composition. As a crosslinking agent, an organic type crosslinking agent and a polyfunctional metal chelate can be used. As an organic type crosslinking agent, an isocyanate type crosslinking agent, a peroxide type crosslinking agent, an epoxy type crosslinking agent, an imine type crosslinking agent, etc. are mentioned. A polyfunctional metal chelate is a thing in which a polyvalent metal is covalently bonded or coordinated with an organic compound. Examples of the polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. have. Examples of the atoms in the organic compound to be covalently bonded or coordinated include oxygen atoms and the like, and examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, ketone compounds, and the like.

When it contains a crosslinking agent, the content becomes like this. Preferably it is 0.01-20 mass parts with respect to 100 mass parts of adhesive resin, More preferably, it is 0.03-10 mass parts. If the crosslinking agent is more than 0.01 parts by mass, the cohesion force of the pressure-sensitive adhesive layer tends not to be insufficient, and there is little possibility that foaming occurs during heating. On the other hand, if it is less than 20 parts by mass, the moisture resistance is sufficient, Peeling becomes difficult to occur.

It is preferable that an adhesive composition mix | blends a silane coupling agent as an additive. Examples of the silane coupling agent include silicon having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. compound; Amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane and N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane; 3-chloropropyltrimethoxysilane; (Meth) acryl group containing silane coupling agents, such as acetoacetyl group containing trimethoxysilane, 3-acryloxypropyl trimethoxysilane, and 3-methacryloxypropyl triethoxysilane; Isocyanate group containing silane coupling agents, such as 3-isocyanatopropyl triethoxysilane, etc. are mentioned. A silane coupling agent can provide the effect which suppresses peeling in durability, especially a humidification environment. The usage-amount of a silane coupling agent is 1 mass part or less with respect to 100 mass parts of adhesive resins, More preferably, it is 0.01-1 mass part, More preferably, it is 0.02-0.6 mass part.

Moreover, the adhesive composition may contain other well-known additives, For example, in an adhesive composition, powder, such as a coloring agent and a pigment, dye, surfactant, a plasticizer, a tackifier, a surface lubricant, a leveling agent, a softener, Antioxidants, antioxidants, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particulates, foils, and the like can be appropriately added depending on the application to be used. Moreover, you may employ | adopt the redox system which added the reducing agent within the range which can be controlled.

The thickness of an adhesive layer is not specifically limited, For example, about 1-100 micrometers, Preferably it is 2-50 micrometers, More preferably, it is 3-30 micrometers.

(Protective layer)

The polarizing plate may include a protective layer. In one embodiment of the present invention, the polarizing plate may be in the form of at least one protective layer, and is located on one surface of the polarizer constituting the polarizing plate or on the surface opposite to the polarizer of the phase difference layer when the polarizer has a phase difference layer. can do.

There is no restriction | limiting in particular as a protective layer as long as it is a film excellent in transparency, mechanical strength, thermal stability, moisture shielding, isotropy, etc. Specifically, polyester-based films such as polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate; Cellulose films such as diacetyl cellulose and triacetyl cellulose; Polycarbonate film; Acrylic films such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene films such as polystyrene and acrylonitrile-styrene copolymers; Polyolefin-based films such as cycloolefin, cycloolefin copolymer, polynorbornene, polypropylene, polyethylene, and ethylene propylene copolymer; Vinyl chloride film; Polyamide-based films such as nylon and aromatic polyamide; Imide film; Sulfone film; Polyether ketone film; Polyphenylene sulfide films; Vinyl alcohol film; Vinylidene chloride-based film; Vinyl butyral film; Arylate film; Polyoxymethylene film; Urethane film; Epoxy film; Silicone film etc. are mentioned. Among these, especially the cellulose type film which has the surface saponified by alkali etc. is preferable in consideration of polarization characteristic or durability. The protective layer may also have an optical compensation function such as a phase difference function.

The protective layer may have been subjected to an easy-adhesion process for improving adhesion to the surface to be bonded to the polarizer or the retardation coating layer. The easily-adhesive treatment is not particularly limited as long as it can improve the adhesive strength, and examples thereof include dry treatments such as primer treatment, plasma treatment and corona treatment; Chemical treatments such as alkali treatment (saponification treatment); Low pressure UV treatment; and the like.

<Touch sensor>

The image display device, particularly the flexible display device, may be provided with a touch sensor as described above. The touch sensor has a support, a lower electrode provided on the support, an upper electrode facing the lower electrode, an insulating layer sandwiched between the lower electrode and the upper electrode.

The support body can employ | adopt various things, if it is a flexible resin film which has light transmittance.

The lower electrode has, for example, a plurality of small electrodes having a square shape in plan view. The plurality of small electrodes are arranged in a matrix.

Further, the plurality of small electrodes are connected to adjacent small electrodes in one diagonal direction of the small electrode to form a plurality of electrode strings. The plurality of electrode strings are connected to each other at the end, and the capacitance between adjacent electrode strings can be detected.

The upper electrode has, for example, a plurality of small electrodes of square shape in plan view. The plurality of small electrodes are complementarily arranged in a matrix at positions where the lower electrodes are not arranged in plan view. That is, the upper electrode and the lower electrode are arranged without a gap in plan view.

Further, the plurality of small electrodes are connected to neighboring small electrodes in the other diagonal direction of the small electrode to form a plurality of electrode strings. The plurality of electrode strings are connected to each other at the end, and the capacitance between adjacent electrode strings can be detected.

The insulating layer insulates the lower electrode and the upper electrode. As a material for forming the insulating layer, a material commonly known as a material for the insulating layer of the touch sensor can be used.

In addition, in this embodiment, although the touch sensor was demonstrated as what is called a projected capacitive touch sensor, in the range which does not impair the effect of this invention, the touch sensor of another system, such as a membrane resistance method, is employ | adopted. You may.

<Shading Pattern>

The light blocking pattern may be at least a portion of a bezel or a housing of a display device to which an optical film or an optical film is applied. For example, the wiring of the display device may be hidden by the light shielding pattern and may not be visually recognized by the user. The color and / or material of the light shielding pattern is not particularly limited, and may be formed of a resin material having various colors such as black, white, and gold. For example, the light shielding pattern may be formed of a resin material such as an acrylic resin, an ester resin, an epoxy resin, polyurethane, silicone, etc., in which a pigment for realizing color is mixed. The material and thickness of the light blocking pattern may be determined in consideration of the protective and flexible characteristics of the optical film or the display device. Moreover, these can also be used individually or in mixture of 2 or more types.

EXAMPLE

<Measurement of weight average molecular weight (Mw)>

Gel Permeation Chromatography (GPC) Measurement

(1) pretreatment method

Polyamideimide: A DMF eluent (10 mmol / L lithium bromide solution) was added to a concentration of 2 mg / mL, heated at 80 ° C. for 30 minutes with stirring, and cooled, followed by 0.45 μm membrane filter filtration to give a measurement solution. .

(2) measurement conditions

Column: TSKgel α-2500 ((7) 7.8mm diameter x 300mm) * 1 made by Tosoh Corporation, α-M ((13) 7.8mm diameter x 300mm) * 2 pieces

Eluent: DMF (10 mmol / L lithium bromide added)

Flow rate: 1.0 mL / min

Detector: RI detector

Column temperature: 40 ℃

Injection volume: 100μL

Molecular Weight Standard: Standard Polystyrene

<Acetamide group content>

(1) Pretreatment Method

Examples and Comparative Examples was dissolved in heavy water a polyamide-imide digestion dimethyl sulfoxide (DMSO-d ₆₎ was obtained in a test sample to a solution of 2% by mass.

(2) NMR measurement conditions

Measuring device: Bruker's 600 MHz NMR device "AVANCE600"

Sample temperature: 303 K

Measurement Method: ¹ H-NMR

Chemical Shift Reference: DMSO (2.50 ppm)

(3) Calculation method of acetamide parameters

¹ H-NMR of the measurement sample was measured under the above measurement conditions. In the ¹ H-NMR spectrum obtained by the above measurement, the peak area in the range of 10.3 to 10.4 ppm of chemical shift values derived from a hydrogen atom bonded to the nitrogen atom in the structure represented by Formula (A) is defined as A. The peak area in the range of the chemical shift value of 6.5-11.5 ppm was set to B, and the percentage A / B × 100 (%) with respect to B of A was obtained.

<Total light transmittance and haze of optical film>

The total light transmittance of an optical film is based on JIS K 7361-1: 1997, and haze is measured based on JIS K 7136: 2000 using the fully automatic direct reading haze computer "HGM-2DP" made by Suga Tester Co., Ltd. did. The measurement sample cut and produced the optical film obtained by the Example and the comparative example to the magnitude | size of 30 mm x 30 mm.

<Yellow degree of optical film>

The yellowness (Yellow Index: YI value) of an optical film was measured using the ultraviolet visible near-infrared spectrophotometer ("V-670" by Nippon KKK). After background measurement was performed in the absence of a sample, the optical films obtained in Examples and Comparative Examples were set in a sample holder to measure transmittance for light of 300 to 800 nm, and three stimulus values (X, Y, Z). Saved. From the obtained 3 magnetic pole values, YI value was computed based on the following formula based on the specification of ASTMD1925.

YI = 100 × (1.2769X-1.0592Z) / Y

<Thickness Distribution of Optical Film>

Cut the center part of the optical film to 5 cm in width and length, and place 5 mm from the outer circumference at 12 places at 1 cm intervals, and micrometer ("ID-C112XBS" made by Mitsutoyo Co., Ltd.) or Digimicro stand (note) Thickness was measured using "MS-5C" by Nikon, and the absolute value of the difference of the maximum value and minimum value of these thickness was made into thickness distribution.

Example 1

Nitrogen was conducted to the 1 L separable flask with a sufficiently dried stirrer and thermometer for at least 30 minutes, and the inside of the vessel was replaced with nitrogen. 250 g of dimethylacetamide (DMAc) was placed in a flask and 14.7 g (45.82 mmol) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and 4,4 '-(hexafluoroisopropyl) at room temperature. 6.14 g (13.82 mmol) of lithium dendritic diphthalic dianhydride (6FDA) was added, and the mixture was left to stand for 16 hours after stirring for 15 minutes or more.

Next, at room temperature, 0.340 g (1.15 mmol) of 4,4'-oxybis (benzoyl chloride) (OBBC) and 1.12 g (5.52 mmol) of terephthaloyl chloride (TPC) were added thereto, followed by stirring at room temperature for 10 minutes. Then, the same amount of OBBC and TPC were added, and the operation of stirring for the same time was further repeated three times. After the reaction liquid was further stirred for 30 minutes, 1.12 g (5.52 mmol) of TPC was added, and the mixture was further stirred at room temperature for 60 minutes. Subsequently, 9.93 g (97.27 mmol) of acetic anhydride and 3.02 g (32.43 mmol) of 4-picoline were added, and after stirring at room temperature for 30 minutes, the temperature was raised to 70 ° C. over 1 hour and held at 70 ° C. for 3 hours. did. To the mass of the reaction solution, 10 times the amount of methanol was added to obtain a white solid. The obtained solid was air-dried over 1 day at room temperature.

After dissolving the obtained solid in 250 g of dimethylacetamide (DMAc), 47.19 g (462.20 mmol) of acetic anhydride was added, the mixture was stirred at room temperature for 30 minutes, and then heated up to 70 ° C. over 1 hour, and then heated at 70 ° C. for 3 hours. Did not see To the mass of the reaction solution, 10 times the amount of methanol was added to obtain a white solid. The obtained solid was air-dried over 1 day at room temperature, and the polyamideimide which has a structure represented by Formula (A) was obtained. The weight average molecular weight (Mw) of the polyamide-imide which has a structure represented by obtained formula (A) is 445,000, A / Bx100 in Formula (X) is 0.05%, and satisfy | fills the relational formula of Formula (X) Let's do it.

Example 2

40 g (124.91 mmol) of TFMB and 682.51 g of DMAc were added to the 1 L separable flask with a stirring blade under nitrogen gas atmosphere, and TFMB was dissolved in DMAc while stirring at room temperature. Next, 6FDA 16.78 g (37.77 mmol) was added to the flask, and the mixture was stirred at room temperature for 3 hours. Thereafter, 3.72 g (12.59 mmol) of OBBC, followed by 15.34 g (75.55 mmol) of terephthaloyl chloride (TPC) was added to the flask and stirred at room temperature for 1 hour. Subsequently, 8.21 g (88.14 mmol) of 4-methylpyridine and 15.43 g (151.10 mmol) of acetic anhydride were added to the flask, and after stirring for 30 minutes at room temperature, the temperature was raised to 70 ° C. using an oil bath. It stirred for the time and obtained the reaction liquid.

The obtained reaction solution was cooled to room temperature, poured into a large amount of methanol in a yarn form, and the precipitate deposited was taken out, and after immersing in methanol for 6 hours, the mixture was washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C to obtain a white solid.

The resulting solid was dissolved in 680 g of dimethylacetamide (DMAc), and then 127.60 g (1250.0 mmol) of acetic anhydride was added, the mixture was stirred at room temperature for 30 minutes, then heated up to 70 ° C. over 1 hour, and then heated at 70 ° C. for 3 hours. Did not see To the mass of the liquid, 10 times the amount of methanol was added to obtain a white solid. The obtained solid was air-dried over 1 day at room temperature, and the polyamideimide which has a structure represented by Formula (A) was obtained. The weight average molecular weight (Mw) of the polyamide-imide resin which has a structure represented by obtained Formula (A) is 400,000, A / Bx100 in Formula (X) is 0.05%, and the relationship of Formula (X) Meets.

Comparative Example 1

52 g (162.38 mmol) of TFMB and 849.23 g of DMAc were added to the 1 L separable flask with a stirring blade under nitrogen gas atmosphere, and TFMB was dissolved in DMAc, stirring at room temperature. Next, 14.45 g (32.52 mmol) of 6FDA was added to the flask, and the mixture was stirred at room temperature for 3 hours. Then, OBBC 4.80g (16.26 mmol) and then TPC 23.11g (113.84 mmol) were added to the flask, and it stirred at room temperature for 1 hour. Subsequently, 9.98 g (126.20 mmol) of pyridine and 13.28 g (130.10 mmol) of acetic anhydride were added to the flask, and after stirring for 30 minutes at room temperature, the temperature was raised to 70 ° C. using an oil bath, followed by further stirring for 3 hours. And the reaction liquid was obtained.

The obtained reaction solution was cooled to room temperature, poured into a large amount of methanol in a yarn shape, and the precipitate precipitated was taken out and immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C to obtain a polyamideimide having a structure represented by formula (A). The weight average molecular weight (Mw) of the obtained polyamideimide is 240,000, A / Bx100 in Formula (X) is 0.02%, and does not satisfy the relation of Formula (X).

<Production of Optical Film>

GBL was added to a silica sol (average primary particle diameter of silica particles: 27 nm) using γ-butyrolactone (GBL) as a dispersion medium, and the polyamideimide obtained in Examples 1, 2 and Comparative Example 1 was further It melt | dissolved and produced the polyamide-imide varnish so that the total mass of polyamide-imide and silica might be 10 mass% with respect to the mass of a varnish, and the ratio (mass ratio) of the solid content of polyamide-imide and silica might be 6: 4. . The obtained polyamideimide varnish was coated on the smooth surface of the polyester base material (Toyobo Co., Ltd., brand name "A4100") using an applicator so that the average thickness of a freestanding film might be 52 micrometers, and it was 50 degreeC 30 Then, it dried for 15 minutes at 140 degreeC, and obtained the self-supporting film. The self-supporting film was fixed to the metal frame of A4 size, it heated up to 200 degreeC over 40 minutes, hold | maintained at 200 degreeC for 20 minutes, and dried, and obtained the optical film. Table 1 shows the evaluation results of the total light transmittance, YI, haze, and thickness distribution of the obtained optical film. In addition, the parenthesis in a thickness distribution column shows (the minimum value of thickness (micrometer) and the maximum value of thickness (micrometer)).

Example 3

In a nitrogen gas atmosphere, TFMB 14.64 g (45.72 mmol) and 500 g of DMAc were added to a 1 L separable flask equipped with a stirring vane, and TFMB was dissolved in DMAc while stirring at room temperature. Next, 6.15 g (13.85 mmol) of 6FDA and 1.36 g (4.63 mmol) of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) were added to the flask, followed by stirring at room temperature for 16 hours. did.

Then, 2.53 g (12.46 mmol) of terephthaloyl chloride (TPC) was added, and after stirring for 10 minutes, TPC 2.53 g (12.46 mmol) was further added and it stirred for 20 minutes. Subsequently, 0.56 g (2.76 mmol) of TPC was further added, and it stirred at room temperature for 2 hours.

Subsequently, 13.20 g (129.30 mmol) of acetic anhydride and 2.58 g (27.71 mmol) of 4-picoline were added, and after stirring at room temperature for 30 minutes, the temperature was raised to 70 ° C. using an oil bath, followed by further stirring for 3 hours. And the reaction liquid was obtained.

When the reaction solution was cooled down to 40 ° C. or lower, the reaction solution was diluted with 54 g of methanol, and 898 g of methanol was further added dropwise. Subsequently, 359 g of ion-exchanged water was added dropwise to precipitate a white solid. The precipitated white solid was collected by vacuum filtration and washed with methanol to obtain a wet cake containing polyamideimide. Next, the precipitate was dried under reduced pressure at room temperature to obtain a polyamideimide (white solid) having a structure represented by formula (A).

The weight average molecular weight (Mw) of the polyamide-imide which has a structure represented by obtained formula (A) is 325,000, A / Bx100 in Formula (X) is 0.03%, and satisfy | fills the relational formula of Formula (X) Let's do it.

Example 4

14.64 g (45.72 mmol) of TFMB and 250 g of DMAc were added to the 1 L separable flask equipped with a stirring vane under nitrogen gas atmosphere, and TFMB was dissolved in DMAc while stirring at room temperature. Next, 6.15 g (13.85 mmol) of 6FDA and 1.36 g (4.63 mmol) of BPDA were added to the flask, and the mixture was stirred at room temperature for 16 hours.

Then, 2.53 g (12.46 mmol) of terephthaloyl chloride (TPC) was added, and after stirring for 10 minutes, TPC 2.53 g (12.46 mmol) was further added and it stirred for 20 minutes. After adding 250.00 g of DMAc and stirring for 10 minutes, TPC 0.56 g (2.76 mmol) was further added, and it stirred at room temperature for 2 hours.

Next, 13.23 g (129.55 mmol) of acetic anhydride and 2.60 g (27.92 mmol) of 4-picoline were added, and after stirring at room temperature for 30 minutes, the temperature was raised to 70 ° C. using an oil bath, followed by further stirring for 3 hours. And the reaction liquid was obtained.

When the reaction liquid was cooled down to 40 ° C. or lower, the reaction liquid was diluted with 29 g of methanol, and 860 g of methanol was further added dropwise. Next, 344 g of ion-exchanged water was added dropwise to precipitate a white solid. The precipitated white solid was collected by vacuum filtration and washed with methanol to obtain a wet cake containing polyamideimide. Next, the precipitate was dried under reduced pressure at room temperature to obtain a polyamideimide (white solid) having a structure represented by formula (A).

The weight average molecular weight (Mw) of the polyamide-imide which has a structure represented by obtained formula (A) is 219,000, A / Bx100 in a formula (X) is 0.03%, and satisfy | fills the relational formula of formula (X) Let's do it.

Comparative Example 2

TFMB 19.17g (59.87 mmol) and DMAc 321.0g were added to the 1 L separable flask with a stirring blade under nitrogen gas atmosphere, and TFMB was dissolved in DMAc, stirring at room temperature. Next, 5.35 g (12.04 mmol) of 6FDA and 1.77 g (6.00 mmol) of BPDA were added to the flask, followed by stirring at room temperature for 16 hours. Thereafter, 3.85 g (18.96 mmol) of TPC was added to the flask, followed by stirring for 10 minutes, and then 3.85 g (18.96 mmol) of TPC was further added and stirred for 20 minutes. 314.1 g of DMAc was added, and after stirring for 10 minutes, 0.86 g (4.22 mmol) of TPC was further added, followed by stirring at room temperature for 2 hours.

Subsequently, 6.23 g (48.22 mmol) of diisopropylethylamine (DIPEA) was added to the flask and stirred for 10 minutes, followed by 8.62 g (84.46 mmol) of acetic anhydride and 4.51 g (48.44 mmol) of 4-picoline. ) Was added, and after stirring at room temperature for 30 minutes, the temperature was raised to 70 ° C using an oil bath, and further stirred for 3 hours to obtain a reaction solution.

When the reaction liquid was cooled down to 50 ° C. or lower, 943 g of methanol was added dropwise, and then 493 g of ion-exchanged water was added dropwise to precipitate a white solid. The precipitated white solid was collected by vacuum filtration and washed with methanol to obtain a wet cake containing polyamideimide. Next, the precipitate was dried under reduced pressure at 60 ° C to obtain a polyamideimide (white solid) having a structure represented by Formula (A).

The weight average molecular weight (Mw) of the polyamide-imide which has a structure represented by obtained formula (A) is 826,000, A / Bx100 in Formula (X) is 0.02%, and satisfies the relationship of Formula (X) Don't let that happen.

<Production of Optical Film>

The polyamide-imide obtained in Examples 3 and 4 was dissolved in GBL, respectively, and the polyamide-imide varnish was produced so that the total mass of polyamide-imide might be 8.5 mass% with respect to the mass of a varnish.

The polyamideimide obtained by the comparative example 2 was dissolved in GBL, and the polyamide-imide varnish was produced so that the total mass of polyamide-imide might be 6.0 mass% with respect to the mass of a varnish.

The obtained polyamideimide varnish is coated on the smooth surface of a polyester base material (Toyobo Co., Ltd. brand name "A4100") using an applicator so that the average thickness of a freestanding film may be 52-56 micrometers, and 50 degreeC 30 minutes, Then, it dried for 15 minutes at 140 degreeC, and obtained the self-supporting film. The self-supporting film was fixed to the metal frame of A4 size, it heated up to 200 degreeC over 40 minutes, hold | maintained at 200 degreeC for 20 minutes, and dried, and obtained the optical film. Table 2 shows the evaluation results of the total light transmittance, YI, haze, and thickness distribution of the obtained optical film. In addition, the parenthesis in a thickness distribution column shows (the minimum value of thickness (micrometer) and the maximum value of thickness (micrometer)).

The optical film obtained in Examples 1-4 has the small thickness distribution compared with the optical film obtained by the comparative examples 1 and 2, and it was confirmed that the nonuniformity of a partial thickness was small and was excellent in the flatness of the film surface. Moreover, it was confirmed that the optical film obtained in Examples 1-4 is high in total light transmittance, and YI value and low haze are compared with the optical film obtained in Comparative Examples 1 and 2. Therefore, it turns out that the optical film of this invention is excellent in the flatness and optical characteristics of a film surface.

Claims (10)

Formula (A)

[In formula (A), * represents a bond.]
At least 1 sort (s) of resin chosen from the group which consists of polyimide-type resin and polyamide-type resin which have a structure represented by these, and the said resin is Formula (X)
A / B × 100≥0.03 (%) (X)
[In Formula (X), A represents the peak area derived from the hydrogen atom couple | bonded with the nitrogen atom in the structure represented by Formula (A) in <^1> H-NMR spectrum of this resin, B is the said resin. In the ¹ H-NMR spectrum, the chemical shift value represents the peak area in the range of 6.5 to 11.5 ppm.]
To meet the optical film. The method of claim 1,
Polyimide-based resin which has a structure represented by Formula (A) is Formula (1)

[In Formula (1), Y is a tetravalent organic group and X is a divalent organic group.]
Containing a structural unit represented by
Polyamide-type resin which has a structure represented by Formula (A) is Formula (2)

[In Formula (2), Z and X are each independently a divalent organic group.]
An optical film containing the structural unit represented by. The method of claim 1,
At least a part of the structure represented by formula (A) is formula (B)

[In formula (B), * represents a bond.]
Optical film which is a structure represented by. The method of claim 1,
The optical film whose weight average molecular weight of at least 1 sort (s) of resin chosen from the group which consists of polyimide-type resin and polyamide-type resin which have a structure represented by Formula (A) is 200,000 or more. The method of claim 1,
An optical film, further comprising silica particles. The method of claim 1,
The optical film whose thickness is 25-100 micrometers. The flexible display device provided with the optical film as described in any one of Claims 1-6. The method of claim 7, wherein
Furthermore, the flexible display apparatus provided with a touch sensor. The method of claim 7, wherein
Furthermore, the flexible display apparatus provided with a polarizing plate. Formula (A)

[In formula (A), * represents a bond.]
As optical resin containing at least 1 sort (s) chosen from the group which consists of polyimide-type resin and polyamide-type resin which have a structure represented by the formula (X)
A / B × 100≥0.03 (%) (X)
[In Formula (X), A represents the peak area derived from the hydrogen atom couple | bonded with the nitrogen atom in the structure represented by Formula (A) in <^1> H-NMR spectrum of the said optical resin, B is In the ¹ H-NMR spectrum of the optical resin, a chemical shift value represents a peak area in a range of 6.5 to 11.5 ppm.]
To meet the optical resin.