KR20200063031A - Optical multilayer body, flexible display device and method for producing optical multilayer body - Google Patents

Abstract

Provided are an optical laminate, a flexible display device having the same, and a method for manufacturing the optical laminate. The optical laminate, which has an optical film including a polyimide-based resin and/or a polyamide-based resin, and a functional layer laminated on at least one side of the optical film, satisfies equation: (Y_(mh) + Y_(mv)) / (X_(mh) + X_(mv))^(1/2) < 30. Therefore, the optical homogeneity is excellent.

Description

Manufacturing method of optical laminate, flexible display device, and optical laminate {OPTICAL MULTILAYER BODY, FLEXIBLE DISPLAY DEVICE AND METHOD FOR PRODUCING OPTICAL MULTILAYER BODY}

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

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

As a method for manufacturing such an optical film, a method is applied in which a solution containing a volatile solvent and a resin constituting the optical film is coated on a substrate, and then dried and peeled off (for example, Patent Document 1). In such a manufacturing method involving coating and drying, thickness unevenness and orientation unevenness may occur depending on coating conditions or drying conditions. Even if the film has a level of non-uniformity that cannot be visually confirmed, optical homogeneity is impaired due to such non-uniformity when finally assembled as an optical film in an image display device, resulting in image distortion, etc. It may be admitted. For this reason, the film used as an optical film in an image display device requires optical homogeneity with a very high level of accuracy that is difficult to visually confirm. Because of this, there is also a need for further improvement of the optical homogeneity of the film.

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

International Publication No. 2016/152459 Japanese Patent Application Publication No. 9-48866 Japanese Patent Application Publication No. 2011-226871

However, all of the methods described in the above-mentioned patent documents cannot be said to be methods sufficient for evaluating the optical homogeneity of films with very high precision required for optical films as used in image display devices. Since the method described in Patent Document 1 is an evaluation in an analysis area of 1 cm x 5 cm, it is not a method capable of sufficiently evaluating a decrease in optical homogeneity due to unevenness occurring in the longitudinal direction. The method described in Patent Document 2 is not a method capable of accurately evaluating a decrease in optical homogeneity caused by a slight non-uniformity of a small difference in luminance of transmitted light.

Since the method described in Patent Document 3 is a method for detecting a shape, it is not possible to evaluate a decrease in optical homogeneity due to non-uniformity in refractive index. Therefore, not all films obtained by evaluating by these methods have sufficient optical homogeneity.

This invention is made|formed in view of the subject which the said prior art has, The optical laminated body excellent in optical homogeneity used suitably as an optical film in an image display apparatus etc., The flexible display device provided with the said optical laminated body, and An object of the present invention is to provide a method for manufacturing the optical laminate.

In order to solve the above problems, the present inventors studied earnestly for an evaluation method capable of evaluating the optical homogeneity of the optical film or optical laminate with high precision, and a method of increasing the optical homogeneity and optical properties of the optical film or optical laminate. Was done. As a result, it was found that the optical laminate satisfying the following requirements has excellent optical homogeneity, leading to the completion of the present invention. That is, the following aspects are included in this invention.

[1] An optical laminate comprising an optical film comprising a polyimide resin and/or a polyamide resin, and a functional layer laminated on at least one side of the optical film,

The line profiles in directions h and v that are orthogonal to each other on the film inverse space obtained by Fourier transforming the projected image obtained by the projection method using the optical film are referred to as line profiles h and line profiles v, respectively. In the above, the line profiles in the directions h'and v'which are orthogonal to each other on the background inverse space obtained by Fourier transforming the background image obtained without using the film are called line profiles h'and line profiles v', respectively. , The maximum intensity of the line profile (h-h') obtained by subtracting the line profile h'from the line profile h is called Y _mh , and the frequency representing the maximum intensity Y _mh is called X _mh , and the line profile _{v'from the} line profile v If the maximum intensity of the line profile (v-v') obtained by subtracting is Y _mv , and the frequency representing the maximum intensity Y _mv is X _mv , Y _mh and Y _mv are both 40 or less, Y _mh , Y _mv , X _mh and X _mv are the following relationships:

To satisfy the optical laminate.

[2] An optical laminate comprising an optical film comprising a polyimide resin and/or a polyamide resin, and a functional layer laminated on at least one side of the optical film,

The line profiles in the directions h and v that are orthogonal to each other on the film inverse space obtained by Fourier transforming the projected image obtained by the projection method using the optical laminate are referred to as line profiles h and line profiles v, respectively. In the projection method, the line profiles in the directions h'and v are orthogonal to each other in the background inverse space obtained by Fourier transforming the background image obtained without using the optical laminate, respectively, the line profile h'and the line profile v The maximum intensity of the line profile (h-h') obtained by subtracting the line profile h from line profile h is called Y _mh , and the frequency representing the maximum intensity Y _mh is called X _mh , and the line from line profile v If the maximum intensity of the line profile (v-v') obtained by subtracting the profile _v'is Y _mv , and the frequency representing the maximum intensity Y _mv is X _mv , Y _mh and Y _mv are both 40 or less, and Y _mh , Y _mv , X _mh and X _mv are the following relationships:

To satisfy the optical laminate.

[3] At least one of the functional layers is a layer having at least one function selected from the group consisting of a hard coating function, an antistatic function, an anti-glare function, a low reflection function, an antireflection function and an antifouling function, The optical laminate according to [1] or [2] above.

[4] The optical laminate according to any one of [1] to [3], wherein the pencil hardness of at least one surface of the optical laminate is H or more.

[5] The optical laminate according to any one of [1] to [4], wherein the surface resistivity of at least one surface of the optical laminate is 1.0×10 ¹³ Ω/sq or less.

[6] The optical laminate according to any one of [1] to [5], wherein the yellowness of the optical laminate is 3.0 or less.

[7] The optical laminate according to any one of [1] to [6], in which the length in the width direction is 20 cm or more and the length in the length direction is 1 m or more.

[8] The optical laminate according to any one of [1] to [7], which is a film for a front plate of a flexible display device.

[9] A flexible display device comprising the optical laminate according to any one of [1] to [8].

[10] The flexible display device according to [9], further comprising a touch sensor.

[11] The flexible display device according to [9] or [10], further comprising a polarizing plate.

[12] As a method for producing the optical laminate according to any one of [1] to [8],

(a) a step of applying a varnish containing at least a polyimide-based resin and/or a polyamide-based resin and a solvent on a support and drying it to form a coating film,

(b) peeling the coating film from the support,

(c) heating the peeled coating film to obtain a film, and

(d) A manufacturing method comprising at least a step of laminating a functional layer on at least one side of a film to obtain an optical laminate.

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

1 is a schematic view showing an arrangement example in a process of obtaining a projected image.
2 is a schematic view for explaining the arrangement in the process of obtaining a projected image in Examples and Comparative Examples.
3 is a diagram for explaining Y _max , X _max and X _cen in the line profile.
4 is a view showing a line profile before normalization obtained from the projected image of Example 1.
5 is a diagram showing line profiles after normalization obtained from the projected image of Example 1. FIG.
6 is a view showing line profiles after normalization obtained from the background image of Example 1. FIG.
7 is a view showing a line profile obtained by subtracting the line profile after normalization obtained from the background image of Example 1 from the line profile after normalization obtained from the projection image of Example 1;
8 is a view showing the line profile obtained by smoothing the line profile obtained by subtracting the line profile after normalization obtained from the background image of Example 1 from the line profile after normalization obtained from the projected image of Example 1;

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

The optical laminated body of this invention WHEREIN: In one aspect of this invention, the optical laminated body which has an optical film containing polyimide type resin and/or polyamide type resin, and the functional layer laminated|stacked on at least one side of the said optical film. as,

The line profiles in directions h and v that are orthogonal to each other on the film inverse space obtained by Fourier transforming the projected image obtained by the projection method using the optical film are referred to as line profiles h and v, respectively. The line profiles in the directions h'and v'which are orthogonal to each other in the background inverse space obtained by Fourier transforming the background image obtained without using the optical film are referred to as line profiles h'and v', respectively. The maximum intensity of the line profile (h-h') obtained by subtracting the line profile h'from h is called Y _mh , and the frequency representing the maximum intensity Y _mh is called X _mh , and obtained by subtracting the line profile v'from the line profile v. _Assuming that the maximum intensity of the line profile (v-v') is Y _mv , and the frequency representing the maximum intensity Y _mv is X _mv , Y _mh and Y _mv are both 40 or less, and Y _mh , Y _mv , X _mh and X _mv is the following relationship:

It is, it is an optical laminate.

The optical laminated body of this invention WHEREIN: In another aspect of this invention, the optical lamination which has the optical film containing polyimide type resin and/or polyamide type resin, and the functional layer laminated|stacked on at least one side of the said optical film. Sieve,

The line profiles in the directions h and v that are orthogonal to each other on the film inverse space obtained by Fourier transforming the projected image obtained by the projection method using the optical laminate are referred to as the line profiles h and v, respectively. The line profiles in the directions h'and v'which are orthogonal to each other on the background inverse space obtained by Fourier transforming the background image obtained without using the optical laminate are referred to as line profiles h'and v', respectively. a line for the maximum strength of the profile line profile h 'line profile (h-h obtained by subtracting') from h and that Y _mh, the frequency showing the maximum intensity Y _mh called X _mh, line profile v 'from the line profile v If the called a maximum intensity of the line profile (v-v ') obtained by subtracting Y _mv, and the frequency showing the maximum intensity Y _mv as X _mv, Y _mh and Y _mv are all less than _{40, Y mh, Y mv,} X _mh and X _mv are the following relationships:

It is, it is an optical laminate. Here, the direction h and the direction h'are directions corresponding to each other, and the direction v and the direction v'are directions corresponding to each other. That these directions correspond means that the azimuth angles are the same.

The optical laminate of the present invention uses the optical film included in the optical laminate of the present invention, or the optical laminate of the present invention as a measurement film, and the Y _mh and the like are evaluated to satisfy the above characteristics. It is an optical laminate. The optical layered body of the present invention satisfying such characteristics has high optical homogeneity. The optical laminate of the present invention has excellent optical homogeneity, and is preferably used as an optical laminate in an image display device. Here, the optical homogeneity of the film is closely related to the surface shape non-uniformity, thickness non-uniformity, and orientation non-uniformity of the film, and when these non-uniformities occur, the optical homogeneity decreases. For this reason, it can be said that the optical laminated body of this invention which has excellent optical homogeneity is a film in which the nonuniformity, such as surface nonuniformity, thickness nonuniformity, and orientation nonuniformity is reduced.

In the film inverse spatial image obtained by Fourier transforming a projected image obtained by a projection method using the optical film included in the optical laminate of the present invention or the optical laminate of the present invention as a measurement film, and in the projection method described above, The background inverse spatial image obtained by Fourier transforming a background image obtained without using a measurement film is not particularly limited as long as it is obtained by Fourier transform from a projected image and a background image, for example.

(1) A step of obtaining a projected image by a projection method in which light from a light source is irradiated onto a measurement film (optical film or optical laminate) and the light transmitted through the measurement film is projected onto a projection surface,

(2) A step of obtaining a background image by projecting light from a light source onto a projection surface without using a measurement film in the projection method of step (1),

And,

(3) The projected image obtained in step (1) and the background image obtained in step (2) are numerically quantified by gray-scale, respectively, and Fourier transform the digitized image data to inverse space (film inverse space and background inverse space) Phase). By evaluating the surface quality of the measurement film using the inverse spatial image, it is possible to analyze the unevenness and the period of irregularity.

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

Subsequently, (4) each line profile in the two directions orthogonal in the inverse space of the background image is subtracted from each line profile in two directions orthogonal in the inverse space of the projected image, and the blank corrected line profile is obtained. obtaining process, and, (5) the maximum intensity of the blank, the corrected line profile obtained in step (4), Y _max (respectively, Y _mh and Y _mv), and the maximum intensity in each of the line profiles Y _max (Y _mh and Y _mv The frequency X _max (X _mh and X _mv ) representing) is measured. For example, a case in which a line profile is created for each of the horizontal direction (h1 direction) and the vertical direction (v1 direction) passing through the center on the inverse space will be described below. The line profile is shown as a graph showing frequency on the X axis and intensity on the Y axis, as shown in FIG. 3, for example. Then, the maximum intensity Y _max in the line profile in the horizontal direction (h1 direction) is referred to as Y _mh1 , and the value X minus the median value X _cen of the total frequency in the blank-corrected line profile from the frequency representing the maximum intensity Y _{mh1 Let max} be X _mh1 . In addition, the maximum intensity Y _max in the line profile in the vertical direction (v1 direction) is referred to as Y _mv1 , and the value X obtained by subtracting the median value X _cen of the entire frequency in the blank-corrected line profile from the frequency representing the maximum intensity Y _{mv1 Let max} be X _mv1 . In the above example, the horizontal direction (h1 direction) and the vertical direction (v1 direction) passing through the center of the space were selected as two directions orthogonal, but the two directions (h direction and v direction) are particularly orthogonal to each other. It is not limited, and may be two directions not passing through the center, and may not be horizontal and vertical directions. In addition, in this specification, the "blank corrected line profile" means each line in the two directions orthogonal in the inverse space of the background image from each line profile in the two directions orthogonal in the inverse space of the projected image. It means the line profile obtained by subtracting each profile. By the above operation, the baseline of the line profile in the inverse space of the projected image can be corrected.

The Y _mh and Y _mv obtained by using the optical film included in the optical laminate of the present invention as a measurement film are all 40 or less. When Y _mh or Y _mv exceeds 40, it cannot be said that the optical homogeneity of the optical film is sufficient, and the optical homogeneity of the optical laminate may not be sufficient. In particular, it cannot be said that the optical homogeneity of the optical laminate containing such an optical film is sufficient for use in an image display device, and it is not possible to sufficiently reduce image distortion and the like. Y _mh and Y _mv are preferably 35 or less, more preferably 32 or less, and even more preferably 30 or less from the viewpoint of easy to increase the optical homogeneity of the optical laminate and to improve image visibility in an image display device. , More preferably 28 or less, particularly preferably 26 or less. The smaller Y _mh and Y _mv , the better. The lower limit is not particularly limited, and may be 0 or more, and is usually 1 or more. About the said Y _mh and Y _mv obtained using the optical laminated body of this invention as a measurement film, the said preferable base material is likewise suitable.

Using the optical film included in the optical laminate of the present invention as a measurement film, Y _mh , Y _mv , X _mh and X _mv obtained as described above have the following relationship:

Meets. When the value of (Y _mh +Y _mv )/(X _mh +X _mv ) ^1/2 exceeds 30, the optical homogeneity is not sufficient, so that screen distortion is likely to occur. The upper limit of the value of (Y _mh +Y _mv )/(X _mh +X _mv ) ^1/2 is preferably 25 or less, more preferably 22 or less, and more preferably from the viewpoint of easily increasing the optical homogeneity. 20 or less, more preferably 19.5 or less, more preferably 19 or less, more preferably 18 or less, more preferably 17 or less, more preferably 16 or less, more preferably 14 or less, more preferably 13 Below, it is 9 or less especially preferably. The smaller the value of (Y _mh +Y _mv )/(X _mh +X _mv ) ^1/2 , the better. The lower limit is not particularly limited and may be 0 or more, and is usually 0.5 or more. The above-described preferred substrate is likewise suitable for the above-mentioned Y _mh , Y _mv , X _mh and X _mv obtained by using the optical laminate of the present invention as a measurement film.

The median value of the total frequency in the blank-corrected line profile obtained as described above using the optical film included in the optical laminate of the present invention or the optical laminate of the present invention as the measurement film is X _cen . For example, in the line profile shown in Fig. 3, the total frequency is 90 cm ^-1 , and the median value of 45 cm ^-1 is X _cen . Here, X _cen and X _mh and X _mv obtained as described above have the following relationship:

It is desirable to meet. Further, in the above formula, X _m represents X _mh or X _mv , and it is preferable that all of X _mh and X _mv satisfy the formula. The lower limit of |X _m -X _cen | is more preferably 0.5 cm ^-1 or more, and still more preferably 1.0 cm ^-1 or more. Moreover, the upper limit of |X _m -X _cen | is more preferably 8.0 cm ^-1 or less, and more preferably 6.0 cm ^-1 or less. It is preferable that X _mh and X _mv in the optical film or optical laminate satisfy the above relationship, having optical homogeneity not recognized as non-uniformity, and considering productivity.

The pencil hardness of at least one side of the optical laminate of the present invention is preferably H or more, more preferably 2H or more, further preferably 3H or more, particularly preferably 4H or more. When the pencil hardness of at least one surface of the optical laminate is greater than or equal to the above hardness, it is easy to prevent scratches or the like on the surface of the optical laminate. It is preferable that the said pencil hardness is the pencil hardness of the surface which has the functional layer (preferably hard coating layer) of the optical laminated body of this invention. Note that the pencil hardness can be measured according to JIS K 5600-5-4:1999, for example, by the method described in Examples.

The surface resistivity of at least one surface of the optical laminate of the present invention is preferably 1.0×10 ¹³ Ω/sq or less, more preferably 5.0×10 ¹² Ω/sq or less, more preferably 1.0×10 ¹² Ω less than /sq. When the surface resistivity is less than or equal to the above upper limit, it is easy to obtain a sufficient antistatic function. The surface resistivity of at least one surface of the optical laminate of the present invention is preferably 1.0×10 ⁷ Ω from the viewpoint of easy to secure the operability of the touch panel when the optical laminate of the present invention is used in combination with a touch panel. /sq or more, more preferably 5.0×10 ⁷ Ω/sq or more, and still more preferably 1.0×10 ⁸ Ω/sq or more. It is preferable that the said surface resistivity is the surface resistivity of the surface which has the functional layer (preferably an antistatic functional layer) of the optical laminated body of this invention. In addition, the surface resistivity can be measured according to JIS K 6911, for example, by the method described in Examples.

In the optical laminate of the present invention, the reflectance of the optical laminate when light is incident from the surface having the functional layer is preferably 3.0% or less, more preferably 2.0% or less, and even more preferably 1.0% or less to be. In addition, the reflectance in this specification means the visibility corrected reflectance, and specifically, the spectral reflectance in the range of the wavelength 350-900 nm at the 12-degree reflection angle when incident light is incident at 12 degrees (that is, the incident angle 12 Refers to the reflectance obtained by correcting the visibility with a 2-degree field of view (C light source) of JIS Z 8701 for positive reflectance in the figure. The reflectance can be measured using a spectrophotometer or the like. In the measurement of the reflectance, for the purpose of excluding the possibility that reflection from a surface opposite to the functional layer surface to which light enters affects the measured value, and for the purpose of preventing warping of the optical laminate, , A sample in which the surface opposite to the functional layer surface to which light is incident is bonded to a black plate (such as a black acrylic plate) using an optically transparent adhesive is used as a sample for measurement.

The yellowness (YI value) of the optical laminate of the present invention is preferably 3.0 or less, more preferably 2.7 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. When the yellowness of the optical layered product is less than or equal to the above upper limit, it is easy to improve transparency, and for example, it is easy to increase visibility when used for the front plate of a display device. The yellowness is usually -5 or more, preferably -2 or more, more preferably 0 or more, more preferably 0.3 or more, still more preferably 0.5 or more, particularly preferably 0.7 or more. The yellowness (YI) was measured in accordance with JIS K 7373:2006 using a UV-visible infrared spectrophotometer and the transmittance of 300-800 nm was measured, and the tristimulus values (X, Y, Z) were obtained. , YI=100×(1.2769X-1.0592Z)/Y.

The total light transmittance of the optical laminate of the present invention is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. When the total light transmittance is equal to or greater than the above lower limit, visibility is easily enhanced when the optical laminate is assembled to an image display device. Since the optical layered product of the present invention has high optical homogeneity and exhibits high transmittance, it is possible to suppress luminescence intensity of display elements and the like required to obtain a constant brightness, for example, when using a film with low transmittance. Becomes For this reason, power consumption can be reduced. For example, when the optical laminate of the present invention is assembled to a display device, a bright display tends to be obtained even if the amount of light of the backlight is reduced, which can contribute to energy saving. The upper limit of the total light transmittance is usually 100% or less. In addition, the total light transmittance can be measured using a haze computer according to JIS K 7361-1:1997, for example. The total light transmittance may be the total light transmittance in the range of the thickness of the optical laminate to be described later.

The haze of the optical laminate of the present invention is preferably 3.0% or less, more preferably 2.0% or less, more preferably 1.0% or less, even more preferably 0.5% or less, particularly preferably 0.3% or less. . When the haze of the optical layered product is less than or equal to the above upper limit, the transparency becomes good, and when used in the front plate of an image display device, for example, it is easy to increase the visibility of the image. In addition, the lower limit of haze is usually 0.01% or more. In addition, haze can be measured using a haze computer according to JIS K 7136:2000.

The thickness of the optical laminate of the present invention may be appropriately adjusted depending on the application, but is preferably 25 µm or more, more preferably 27 µm or more, still more preferably 30 µm or more, and preferably 100 µm or less, more It is preferably 90 µm or less, and more preferably 85 µm or less. The thickness of the optical laminate can be measured by a film thickness meter or the like, for example, by the method described in Examples.

The optical laminate of the present invention has an optical film comprising a polyimide-based resin and/or a polyamide-based resin, and a functional layer laminated on at least one side of the optical film. From the viewpoint of easy to produce an optical film having high homogeneity having the above characteristics with respect to Y _{mh or the} like, and/or from the viewpoint of easy to produce an optical laminate with high properties having the above characteristics, optical in the optical laminate of the present invention The film is preferably a cast film. In the present specification, with the cast film, for example, a solution, dispersion, or melt containing the resin is cast, coated, or the like on a suitable support to form a film by heating, cooling, drying, or the like. The film obtained by peeling the said coating film from the said support body is shown. The film thus obtained contains at least a polyimide-based resin and/or a polyamide-based resin, and optionally contains a trace amount of a solvent.

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

<Polyimide resin and polyamide resin>

In the optical layered product of the present invention, the optical film contains a polyimide-based resin and/or a polyamide-based resin. The polyimide-based resin is a resin containing a repeating structural unit containing an imide group (hereinafter sometimes referred to as a polyimide resin), and a resin containing a repeating structural unit containing both imide groups and amide groups ( Hereinafter, at least one resin selected from the group consisting of polyamideimide resins may be used. In addition, the polyamide-based resin refers to a resin containing a repeating structural unit containing an amide group.

In one preferred embodiment of the present invention, the polyimide-based resin is a polyimide resin having a structural unit represented by formula (1), or a structural unit represented by formula (1) and a structural unit represented by formula (2) It is preferable that it is a polyamideimide resin having a. Moreover, it is preferable that a polyamide resin is a polyamide resin which has a structural unit represented by Formula (2). Hereinafter, Formula (1) and Formula (2) are described, but the description of Formula (1) relates to both the polyimide resin and the polyamideimide resin, and the description of Formula (2) is poly It relates to both an amide resin and a polyamideimide resin.

The structural unit represented by Formula (1) is a structural unit formed by the reaction of a tetracarboxylic acid compound and a diamine compound, and the structural unit represented by Formula (2) is a structural unit formed by a reaction between a dicarboxylic acid compound and a diamine compound. to be.

In formula (2), Z is a divalent organic group, and preferably may be substituted with a hydrocarbon group having 1 to 8 carbon atoms or a hydrocarbon group having 1 to 8 carbon atoms substituted with fluorine, and a divalent oil having 4 to 40 carbon atoms. It is a device, and more preferably, it may be substituted with a hydrocarbon group having 1 to 8 carbon atoms or a hydrocarbon group having 1 to 8 carbon atoms substituted with fluorine, and is a divalent organic group having 4 to 40 carbon atoms having a cyclic structure. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. As an organic group of Z, the following formulas (20), (21), (22), (23), (24), (25), (26), (27), and ( 28) and a group represented by formula (29), a group in which two nonadjacent groups are substituted with hydrogen atoms and a divalent chain hydrocarbon group having 6 or less carbon atoms are exemplified, and the heterocyclic structure of Z has a thiophene ring skeleton. Gi is illustrated. From the viewpoint of easily suppressing the yellowness of the optical film (reducing the YI value), groups represented by formulas (20) to (27) and groups having a thiophene ring skeleton are preferred.

In one embodiment of the present invention, the polyamide resin and the polyamideimide resin may contain multiple types of Z, and the multiple types of Z may be the same or different from each other. Particularly, from the viewpoint of easy to increase the surface hardness of the optical film and the viewpoint of easy to improve the optical properties, at least a part of Z is expressed by the formula (3)

[In the formula (3), R ¹ to 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 an aryl group having 6 to 12 carbon atoms, and R ¹ to R The hydrogen atoms contained in ⁸ may be each independently substituted with a halogen atom,

A is, independently of each other, a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO- or -N(R ⁹ )-, R ⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom,

m is an integer from 0 to 4,

* Represents a bonding hand]

It is preferred to appear.

In formula (3), A is a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C( CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO- or -N(R ⁹ )-, and from the viewpoint of bending 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 are, independently of each other, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or 6 carbon atoms. -12 represents an aryl group. 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. Examples of the alkoxy group having 1 to 6 carbon atoms include, for example, methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butoxy group, isobutoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy And timing. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a biphenyl group. From the viewpoint of the surface hardness and flexibility of the optical film, R ¹ to R ⁸ independently of each other preferably 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 independently substituted with halogen atoms.

R ⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, 2-methyl -Butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group, n-decyl group and the like. And these may be substituted with halogen atoms. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, and iodine atom. The polyimide-based resin or polyamide-based resin may contain a plurality of types of A, and the plurality of types of A may be the same as or different from each other.

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

In one preferred embodiment of the present invention, the resin has a structural unit represented by formula (3), m=0, and R ⁵ to R ⁸ are hydrogen atoms. In one more preferred embodiment of the present invention, the resin is a structural unit represented by formula (3), m=0, and further, R ⁵ to R ⁸ are hydrogen atoms and a structural unit (3'):

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

In one preferred embodiment of the present invention, in which the optical laminate has an optical film containing a polyamideimide resin, the sum of the structural units represented by formula (1) and the structural units represented by formula (2) of the polyamideimide resin When is 100 mol%, the proportion of the structural unit represented by formula (3) is preferably 20 mol% or more, more preferably 30 mol% or more, still more preferably 40 mol% or more, particularly preferably 50 mol% or more, most preferably 60 mol% or more, preferably 90 mol% or less, more preferably 85 mol% or less, and even more preferably 80 mol% or less. When the proportion of the structural unit represented by formula (3) is equal to or greater than the above lower limit, it is easy to increase the surface hardness of the optical film and also to increase the bending resistance and elastic modulus. When the proportion of the structural unit represented by formula (3) is equal to or less than the above upper limit, the increase in viscosity of the resin-containing varnish due to hydrogen bonding between the amide bonds derived from formula (3) is suppressed, and it is easy to improve the processability of the film.

In addition, when the polyamideimide resin has a structural unit of formula (3) with m=1 to 4, the sum of the structural units represented by formula (1) and the structural unit represented by formula (2) of the polyamideimide resin is 100. The ratio of the structural units of the formula (3) in which m is 1 to 4, in terms of mol%, is preferably 3 mol% or more, more preferably 5 mol% or more, still more preferably 7 mol% or more, particularly Preferably it is 9 mol% or more, Preferably it is 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. When the ratio of the structural unit of the formula (3) in which m is 1 to 4 is more than the above lower limit, it is easy to increase the surface hardness and flex resistance of the optical film. When the proportion of the structural unit of formula (3) in which m is 1 to 4 is equal to or less than the above upper limit, the increase in viscosity of the resin-containing varnish due to hydrogen bonding between amide bonds derived from formula (3) is suppressed to improve the processability of the film. Easy to do Moreover, content of the structural unit represented by Formula (1), Formula (2), or Formula (3) can be measured using ¹ H-NMR, for example, or can be calculated from the introduction ratio of a raw material.

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

In a preferred embodiment of the present invention, Z in the polyamide resin or the polyamideimide resin is preferably 5 mol% or more, more preferably 8 mol% or more, further preferably 10 mol% or more, particularly Preferably, 12 mol% or more is represented by Formula (3) in which m is 1-4. When the above-mentioned lower limit of Z of the polyamideimide resin is expressed by the formula (3) in which m is 1 to 4, it is easy to increase the surface hardness of the optical film, and also to increase the bending resistance and elastic modulus. In addition, Z is preferably 90 mol% or less, more preferably 70 mol% or less, more preferably 50 mol% or less, particularly preferably 30 mol% or less, and m is 1 to 4 (3 ). When the above upper limit of Z is represented by formula (3) in which m is 1 to 4, the increase in viscosity of the resin-containing varnish by hydrogen bonding between amide bonds derived from formula (3) in which m is 1 to 4 is suppressed, It is easy to improve the processability of the film. Moreover, the ratio of the structural unit represented by Formula (3) in which m is 1-4 in resin can be measured using ¹ H-NMR, for example, or can be calculated from the introduction ratio of a raw material.

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

In formulas (10) to (18), * represents a bonding hand,

V ¹ , V ² and V ³ are, independently of each other, a single bond, -O-, -S-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -CO- or -N(Q)-. Here, Q represents a C1-C12 monovalent hydrocarbon group which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include the groups described above for R ⁹ .

In one example, V ¹ and V ³ are a single bond, -O- or -S-, and V ² is -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) _2- Or -SO ₂ -. 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, independently of each other, preferably a meta position or a para position for each ring, more preferably It is para position.

Among the groups represented by the formulas (10) to (18), from the viewpoint of easily increasing the surface hardness and bending resistance of the optical film, the formulas (13), (14), (15), (16), and ( The group represented by 17) is preferable, and the group represented by formula (14), formula (15) and formula (16) is more preferable. Further, V ¹ , V ² and V ³ are preferably a single bond, -O- or -S-, independently of each other, from the viewpoint of easy to increase the surface hardness and flexibility of the optical film, single bond or -O- It is more preferable.

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

[In the formula (4), R ¹⁰ to R ¹⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and R ¹⁰ to R ¹⁷ Hydrogen atoms contained in, independently of each other, may be substituted with a halogen atom, * represents a bond;

It is a structural unit represented by. When at least a part of the plurality of Xs in the formulas (1) and (2) is a group represented by the formula (4), it is easy to increase the surface hardness and transparency of the optical film.

In Formula (4), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are, independently of each other, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, 1 to 6 carbon atoms Represents an alkoxy group or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, or the aryl group having 6 to 12 carbon atoms, the alkyl group having 1 to 6 carbon atoms in the formula (3), the alkoxy group having 1 to 6 carbon atoms or the carbon number 6 to 12 Examples of the aryl group include. R ¹⁰ to R ¹⁷ are, independently of each other, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, wherein R ¹⁰ to R ¹⁷ The hydrogen atoms contained may be independently substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R ¹⁰ to R ¹⁷ are, independently of each other, more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group, or a trifluoromethyl group, from the viewpoint of the surface hardness, transparency, and bending resistance of the optical film, particularly preferably Is 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, particularly preferably R ¹¹ and R ¹⁷ are a methyl group or a trifluoromethyl group.

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

It is a structural unit represented by, ie, at least a part of a plurality of X is a structural unit represented by formula (4'). In this case, the solubility of the polyimide-based resin or the polyamide-based resin is increased by the skeleton containing the fluorine element, and it is easy to improve the storage stability of the varnish containing the resin, and the viscosity of the varnish is reduced. It is easy to do, and it is easy to improve the workability of the optical film. Moreover, it is easy to improve the optical properties of an optical film by the skeleton containing elemental fluorine.

In a preferred embodiment of the present invention, X in the polyimide-based resin or polyamide-based resin is preferably 30 mol% or more, more preferably 50 mol% or more, and even more preferably 70 mol% or more. It is represented by equation (4), especially equation (4'). When X in the above range in the polyimide-based resin or the polyamide-based resin is represented by formula (4), particularly formula (4'), the solubility of the resin in the solvent is easily improved by the skeleton containing the fluorine element, It is easy to improve the storage stability of the varnish containing the resin, and it is easy to reduce the viscosity of the varnish, and it is easy to improve the processability of the optical film. In addition, the optical properties of the optical film are also easily improved by the skeleton containing the fluorine element. Moreover, preferably, 100 mol% or less of X in the said polyimide-type resin or polyamide-type resin is represented by Formula (4), especially Formula (4'). X in the said polyamideimide resin may be Formula (4), especially Formula (4'). The ratio of the structural unit represented by the formula (4) of X in the resin can be measured, for example, using ¹ H-NMR, or can be calculated from the introduction ratio of the raw material.

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

In equation (20) to equation (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 an arylene group having 6 to 20 carbon atoms in which the hydrogen atom may be substituted with a fluorine atom, and a phenylene group is mentioned as a specific example.

Among the groups represented by formulas (20) to (29), from the viewpoint of surface hardness and flexural resistance of the optical film, groups represented by formulas (26), (28), or (29) are preferred, and formula (26) The group represented by is more preferable. In addition, W ¹ is a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -independently of each other, from the viewpoint of easy to increase the surface hardness and bending resistance of the optical film and to reduce the yellowness. , -CH(CH ₃ )-, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -is preferred, single bond, -O-, -CH ₂ -, -CH(CH ₃ )- , -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -is more preferable, and single bond, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -is more preferable.

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

[In the formula (5), R ¹⁸ to R ²⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and R ¹⁸ to R ²⁵ The hydrogen atoms contained in may be independently substituted with halogen atoms,

* Represents a bonding hand]

It is a structural unit represented by. If at least a part of the plurality of Ys in the formula (1) is a group represented by the formula (5), the solubility of the polyimide-based resin in the solvent is increased, and the viscosity of the varnish containing the polyimide-based resin is easy to reduce, and the optical film It is easy to improve the workability. In addition, it is easy to improve the optical properties of the optical film.

In formula (5), R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ are, independently of each other, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, 1 to 6 carbon atoms Represents an alkoxy group or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms and the aryl group having 6 to 12 carbon atoms, the alkyl group having 1 to 6 carbon atoms in the formula (3), the alkoxy group having 1 to 6 carbon atoms, or the carbon number having 6 to 12 carbon atoms. The thing mentioned above is mentioned as an aryl group of. R ¹⁸ to R ²⁵ are, independently of each other, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, wherein R ¹⁸ to R ²⁵ The hydrogen atoms contained may be independently substituted with halogen atoms. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom and iodine atom. R ¹⁸ to R ²⁵ are, independently of each other, more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group, or a trifluoromethyl group, from the viewpoint of improving the surface hardness, bending resistance, and transparency of the optical film, 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 groups, fluoro groups, chloro groups or trifluoromethyl groups, Especially preferably, R ²¹ and R ²² are a methyl group or a trifluoromethyl group.

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

It is a group represented by, that is, at least a part of a plurality of Y is a structural unit represented by formula (5'). In this case, the solubility of the polyimide resin in the solvent is increased by the skeleton containing the fluorine element, and it is easy to improve the storage stability of the varnish containing the resin, and it is easy to reduce the viscosity of the varnish. It is easy to improve the workability. Moreover, it is easy to improve the optical properties of an optical film by the skeleton containing elemental fluorine.

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

The polyimide-based resin or polyamide-based resin may contain, in addition to the structural units represented by formulas (1) and (2), structural units represented by formula (30) and/or structural units represented by formula (31). .

In formula (30), Y ¹ is a tetravalent organic group, and preferably an hydrogen group in the organic group may be substituted with a hydrocarbon group or a 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 A group represented by (29), a group in which hydrogen atoms in the groups represented by formulas (20) to (29) are substituted with a methyl group, a fluoro group, a chloro group, or a trifluoromethyl group, and a tetravalent chain hydrocarbon having 6 or less carbon atoms Gi is illustrated. In one embodiment of the present invention, a polyimide resin or a polyamide-based resin may include a plurality of types of Y ^1, Y ¹ of a plurality of species, and may be same or different from each other.

In Formula (31), Y ² is a trivalent organic group, and preferably an hydrogen group in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. As Y ² , the above formulas (20), (21), (22), (23), (24), (25), (26), (27), and (28) And a group in which any one of the bonds of the group represented by formula (29) is substituted with a hydrogen atom, and a trivalent carbon group having 6 or less chain hydrocarbon groups. In one embodiment of the present invention, a polyimide resin or a polyamide-based resin 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 Formulas (30) and (31), X ¹ and X ² are, independently of each other, a divalent organic group, preferably an oil in which the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. It is a device. As X ¹ and X ² , the above formula (10), formula (11), formula (12), formula (13), formula (14), formula (15), formula (16), formula (17) and formula Group represented by (18); A group in which hydrogen atoms in the groups represented by the formulas (10) to (18) are substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And chain hydrocarbon groups having 6 or less carbon atoms.

In one embodiment of the present invention, the polyimide-based resin or polyamide-based resin is a structural unit represented by formulas (1) and/or formula (2), and optionally formulas (30) and/or formulas (31) ). In addition, from the viewpoint of the optical properties, surface hardness and bending resistance of the optical film, in the polyimide-based resin or polyamide-based resin, the structural units represented by formulas (1) and (2) are represented by formula (1) and Based on Formula (2), and optionally the total structural units represented by Formulas (30) and (31), preferably 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol % Or more. In addition, in the polyimide-based resin or polyamide-based resin, the structural units represented by formulas (1) and (2) are represented by formulas (1) and (2), and, optionally, formulas (30) and/or Based on the total structural unit represented by formula (31), it is usually 100% or less. In addition, the said ratio can be measured using ¹ H-NMR, for example, or can be calculated from the introduction ratio of a raw material.

In one embodiment of the present invention, the content of the polyimide-based resin and/or the polyamide-based resin in the optical film is preferably 10 parts by mass or more, more preferably 30 parts by mass with respect to 100 parts by mass of the optical film It is at least 50 parts by mass, more preferably at least 50 parts by mass, preferably at least 99.5 parts by mass, and more preferably at most 95 parts by mass. When the content of the polyimide resin and/or the polyamide resin is within the above range, it is easy to improve the optical properties and elastic modulus of the optical film.

The weight average molecular weight (Mw) of the polyimide-based resin or polyamide-based resin is preferably 230,000 or more, more preferably 250,000 or more, in terms of standard polystyrene, from the viewpoint of easily increasing the surface hardness and flex resistance of the optical film. , More preferably 270,000 or more, particularly preferably 300,000 or more. In addition, from the viewpoint of easy to improve the solubility of the polyamide-based resin or polyimide-based solvent in a solvent, and easy to improve the stretchability and processability of the optical film, the weight average molecular weight of the resin is preferably 1,000,000 or less , More preferably 800,000 or less, more preferably 700,000 or less, particularly preferably 500,000 or less. The weight average molecular weight can be determined by, for example, GPC measurement, by standard polystyrene conversion, and may be calculated, for example, by the method described in Examples.

In the polyamideimide resin, the content of the structural unit represented by the formula (2) is preferably 0.1 mol or more, more preferably 0.5 mol or more, and more preferably 1 mol of the structural unit represented by the formula (1). Is 1.0 mol or more, particularly preferably 1.5 mol or more, preferably 6.0 mol or less, more preferably 5.0 mol or less, and even more preferably 4.5 mol or less. When content of the structural unit represented by Formula (2) is more than the said lower limit, it is easy to raise the surface hardness of an optical film. Moreover, when content of the structural unit represented by Formula (2) is below the said upper limit, it is easy to suppress the thickening by hydrogen bonding between amide bonds in Formula (2), and to improve the workability of an optical film.

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

The content of the halogen atom in the polyimide-based resin or polyamide-based resin is preferably 1 to 40% by mass, more preferably 5 to 40% by mass, based on the mass of the polyimide-based resin or polyamide-based resin. It is mass %, More preferably, it is 5-30 mass %. When the content of the halogen atom is greater than or equal to the above lower limit, the elastic modulus of the optical film is further improved, the absorption rate is lowered, the yellowness is further reduced, and transparency and visibility are more easily improved. When the content of the halogen atom is equal to or less than the above upper limit, the resin is easily synthesized.

The imidation ratio of the polyimide resin and the polyamideimide resin is preferably 90% or more, more preferably 93% or more, and even more preferably 96% or more. From the viewpoint of easy to increase the optical homogeneity of the optical film and/or the optical laminate, it is preferable that the imidation ratio is more than the above lower limit. In addition, the upper limit of the imidation rate is 100% or less. The imidation ratio is the ratio of the molar amount of imide bonds in the polyimide resin and the polyamideimide resin to the value twice the molar amount of the structural unit derived from the tetracarboxylic acid compound in the polyimide resin or polyamideimide resin. Shows. Moreover, when a polyimide resin and a polyamideimide resin contain a tricarboxylic acid compound, the value of 2 times the molar amount of the structural unit derived from the tetracarboxylic acid compound in a polyimide resin and a polyamideimide resin, and tricar The ratio of the molar amount of imide bonds in the polyimide resin and the polyamideimide resin to the total with the molar amount of the structural unit derived from the present acid compound is shown. Moreover, the imidation rate can be calculated|required by IR method, NMR method, etc., For example, in the NMR method, it can measure by the method described in an Example.

As the polyimide-based resin and the polyamide-based resin, commercial products may be used. As a commercial item of a polyimide resin, Mitsubishi Gas Chemical Co., Ltd. Neopurim (trademark), Kawamura Industries Co., Ltd. KPI-MX300F etc. are mentioned, for example.

As to various properties of the optical laminate of the present invention, the properties such as yellowness, surface hardness, optical properties, flex resistance, flexibility, elasticity, transparency, visibility and absorption of the optical laminate are the yellowness and surface of the optical film. When hardness, optical properties, flex resistance, flexibility, modulus of elasticity, transparency, visibility, and water absorption are improved, it tends to be possible to improve similarly. The properties of the optical laminate, such as surface hardness and pencil hardness, of the surface having the functional layer are susceptible to influence by the type of functional layer and the like.

<Method of manufacturing resin>

The polyimide resin can be produced using, for example, a tetracarboxylic acid compound and a diamine compound as main raw materials, and the polyamideimide resin is mainly composed of, for example, a tetracarboxylic acid compound, a dicarboxylic acid compound, and a diamine compound. It can be produced as a raw material, and a polyamide resin can be produced using, for example, a dicarboxylic acid compound and a diamine compound as main raw materials. Here, it is preferable that the dicarboxylic acid compound contains at least a compound represented by formula (3").

In the formula (3"), R ¹ to 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 an aryl group having 6 to 12 carbon atoms, and R ¹ to The hydrogen atoms contained in R ⁸ may be independently substituted with halogen atoms,

A is a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -,- SO ₂ -, -S-, -CO- or -N(R ⁹ )-,

R ⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom,

m is an integer from 0 to 4,

R ³¹ and R ³² each independently represent a hydroxyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group or a chlorine atom. Shows.]

In one preferred embodiment of the present invention, the dicarboxylic acid compound is a compound represented by formula (3") in which m is 0. As a dicarboxylic acid compound, in a compound represented by formula (3") in which m is 0, In addition, it is more preferable to use a compound represented by formula (3") in which A is an oxygen atom. Further, in another preferred embodiment, the dicarboxylic acid compound is a formula in which R ³¹ and R ³² are chlorine atoms. (3"). Moreover, you may use the diisocyanate compound instead of the diamine compound.

As a diamine compound used for manufacture of resin, aliphatic diamine, aromatic diamine, and mixtures thereof are mentioned, for example. In addition, in this embodiment, "aromatic diamine" refers to the diamine in which the amino group is directly bonded to the aromatic ring, and may contain an aliphatic group or other substituents in a part of the structure. The aromatic ring may be a monocyclic ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring, but are not limited thereto. Among these, it is preferably a benzene ring. In addition, "aliphatic diamine" refers to a diamine in which the amino group is directly bonded to an aliphatic group, and an aromatic ring or other substituent may be included in a part of the structure.

Examples of the aliphatic diamine include acyclic aliphatic diamines such as hexamethylenediamine, and 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, norbornadiamine and 4, And cyclic aliphatic diamines such as 4'-diaminodicyclohexylmethane. These may be used alone or in combination of two or more.

Examples of aromatic diamines 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'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-dia Minodiphenylsulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[ 4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis [4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane , 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl (sometimes referred to as TFMB), 4,4'-bis(4- Aminophenoxy)biphenyl, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, 9,9-bis(4-amino-3- And aromatic diamines having two or more aromatic rings, such as chlorophenyl)fluorene and 9,9-bis(4-amino-3-fluorophenyl)fluorene. These may be used alone or in combination of two or more.

The aromatic diamine is preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether. , 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl] Sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy) )Phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl (TFMB), 4,4'-bis(4-aminophenoxy C) biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diamino Diphenylsulfone, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl] Propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl (TFMB), 4,4'-bis(4-aminophenoxy) ratio Phenyl. These may be used alone or in combination of two or more.

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

Examples of the tetracarboxylic acid compound used in the production of the resin include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic acid anhydride; And aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic acid anhydride. The tetracarboxylic acid compounds may be used alone or in combination of two or more. The tetracarboxylic acid compound may be a tetracarboxylic acid compound analog, such as an acid chloride compound, other than an anhydride.

Specific examples of the aromatic tetracarboxylic acid anhydride include non-condensed polycyclic aromatic tetracarboxylic acid anhydride, monocyclic aromatic tetracarboxylic acid anhydride, and condensed polycyclic aromatic tetracarboxylic acid anhydride. As the non-condensed polycyclic aromatic tetracarboxylic acid anhydride, for example, 4,4'-oxydiphthalic acid 2 anhydride, 3,3',4,4'-benzophenone tetracarboxylic acid 2 anhydride, 2,2', 3,3'-benzophenone tetracarboxylic acid anhydride, 3,3',4,4'-biphenyltetracarboxylic acid anhydride, 2,2',3,3'-biphenyltetracarboxylic acid anhydride, 3 ,3',4,4'-diphenylsulfonetetracarboxylic acid anhydride, 2,2-bis(3,4-dicarboxyphenyl)propane 2 anhydride, 2,2-bis(2,3-dicarboxyphenyl) Propane 2 anhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl) propane 2 anhydride, 4,4'-(hexafluoroisopropylidene) diphthalic acid 2 anhydride (sometimes referred to as 6FDA) , 1,2-bis(2,3-dicarboxyphenyl)ethane anhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane anhydride, 1,2-bis(3,4-dicarboxyphenyl) )Ethane anhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane anhydride, bis(3,4-dicarboxyphenyl)methane 2 anhydride, bis(2,3-dicarboxyphenyl)methane 2 anhydride , 4,4'-(p-phenylenedioxy)diphthalic anhydride and 4,4'-(m-phenylenedioxy)diphthalic anhydride. Moreover, as a monocyclic aromatic tetracarboxylic dianhydride, 1,2,4,5-benzenetetracarboxylic dihydride is mentioned, for example, As a condensed polycyclic aromatic tetracarboxylic dianhydride, for example And 2,3,6,7-naphthalenetetracarboxylic acid anhydride.

Among these, preferably 4,4'-oxydiphthalic acid 2 anhydride, 3,3',4,4'-benzophenone tetracarboxylic acid 2 anhydride, 2,2',3,3'-benzophenone tetracarboxylic acid 2 anhydride, 3,3',4,4'-biphenyltetracarboxylic acid 2 anhydride, 2,2',3,3'-biphenyltetracarboxylic acid 2 anhydride, 3,3',4,4'-di Phenylsulfontetracarboxylic acid anhydride, 2,2-bis(3,4-dicarboxyphenyl)propane 2 anhydride, 2,2-bis(2,3-dicarboxyphenyl)propane 2 anhydride, 2,2-bis( 3,4-dicarboxyphenoxyphenyl)propane 2 anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid 2 anhydride (6FDA), 1,2-bis(2,3-dicarboxyphenyl)ethane 2 anhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane 2 anhydride, 1,2-bis(3,4-dicarboxyphenyl)ethane 2 anhydride, 1,1-bis(3,4-di Carboxyphenyl)ethane anhydride, bis(3,4-dicarboxyphenyl)methane 2 anhydride, bis(2,3-dicarboxyphenyl)methane 2 anhydride, 4,4'-(p-phenylenedioxy)diphthalic acid 2 And anhydride and 4,4'-(m-phenylenedioxy)diphthalic anhydride, more preferably 4,4'-oxydiphthalic anhydride, 3,3',4,4'-biphenyl Tetracarboxylic acid anhydride, 2,2',3,3'-biphenyltetracarboxylic acid anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid anhydride (6FDA), bis(3,4 -Dicarboxyphenyl)methane 2 anhydride and 4,4'-(p-phenylenedioxy)diphthalic acid 2 anhydride. These may be used alone or in combination of two or more.

Examples of the aliphatic tetracarboxylic acid anhydride include cyclic or acyclic aliphatic tetracarboxylic acid anhydride. The cyclic aliphatic tetracarboxylic acid anhydride is a tetracarboxylic acid anhydride having an alicyclic hydrocarbon structure, and specific examples thereof include 1,2,4,5-cyclohexanetetracarboxylic acid anhydride, 1,2,3,4- Cycloalkanetetracarboxylic dianhydride, such as cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3, And 5,6-tetracarboxylic acid anhydride, dicyclohexyl-3,3',4,4'-tetracarboxylic acid anhydride and their positional isomers. These may be used alone or in combination of two or more. Specific examples of the acyclic aliphatic tetracarboxylic acid dianhydride include 1,2,3,4-butanetetracarboxylic acid anhydride, 1,2,3,4-pentanetetracarboxylic acid anhydride, and the like. Or can be used in combination of two or more. Moreover, you may use combining cyclic aliphatic tetracarboxylic acid dianhydride and acyclic aliphatic tetracarboxylic acid dianhydride.

Among the above tetracarboxylic acid anhydrides, 4,4'-oxydiphthalic acid 2 anhydride, 3,3',4, from the viewpoint of high surface hardness, high transparency, high flexibility, high bending resistance, and low colorability of the optical film. 4'-benzophenone tetracarboxylic acid anhydride, 3,3',4,4'-biphenyltetracarboxylic acid anhydride, 2,2',3,3'-biphenyltetracarboxylic acid anhydride, 3,3 ',4,4'-diphenylsulfonetetracarboxylic acid anhydride, 2,2-bis(3,4-dicarboxyphenyl)propane 2 anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid 2 Anhydrides, and mixtures thereof are preferred, 3,3',4,4'-biphenyltetracarboxylic acid anhydride and 4,4'-(hexafluoroisopropylidene)diphthalic acid 2 anhydride, and mixtures thereof 4,4'-(hexafluoroisopropylidene)diphthalic acid dianhydride (6FDA) is more preferable.

As the dicarboxylic acid compound used in the production of the resin, terephthalic acid, 4,4'-oxybisbenzoic acid or an acid chloride compound thereof is preferably used. In addition to terephthalic acid, 4,4'-oxybisbenzoic acid or their acid chloride compounds, other dicarboxylic acid compounds may be used. As another dicarboxylic acid compound, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, these flexible acid chloride compounds, acid anhydrides, etc. are mentioned, You may use it in combination of 2 or more type. As a specific example, Isophthalic acid; Naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; A dicarboxylic acid compound of a chain hydrocarbon having 8 or less carbon atoms and two benzoic acids are single-bonded, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or a phenylene group Compounds and their acid chloride compounds. As a specific example, 4,4'-oxybis (benzoyl chloride) and terephthaloyl chloride are preferable, and 4,4'-oxybis (benzoyl chloride) and terephthaloyl chloride are more preferably used in combination.

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

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

Examples of the tricarboxylic acid compound include aromatic tricarboxylic acid, aliphatic tricarboxylic acid, and their flexible acid chloride compounds and acid anhydrides, and may be used in combination of two or more. Specific examples include anhydrides of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalene tricarboxylic acid-2,3-anhydride; And a compound in which phthalic anhydride and benzoic acid are single-linked, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or a phenylene group.

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

In the production of the resin, the reaction temperature of the diamine compound, the tetracarboxylic acid compound and the dicarboxylic acid compound is not particularly limited, for example, 5 to 350°C, preferably 20 to 200°C, more preferably 25 to 100°C. The reaction time is not particularly limited, but is, for example, about 30 minutes to 10 hours. If necessary, the reaction may be performed under an inert atmosphere or a reduced pressure condition. In a preferred aspect, the reaction is performed under normal pressure and/or inert gas atmosphere while stirring. Moreover, it is preferable to perform reaction in a solvent inert to reaction. The solvent is not particularly limited as long as it does not affect the reaction, but, 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-based solvents such as tetrahydrofuran and dimethoxyethane; Chlorine-containing solvents such as chloroform and chlorobenzene; Amide solvents such as N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide (DMF); Sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide and sulfolane; Carbonate-based solvents such as ethylene carbonate and propylene carbonate; And combinations thereof (mixed solvents). Among these, an amide solvent can be suitably used from the viewpoint of solubility.

In the imidation step in the production of a polyimide-based resin, imidization can be performed in the presence of an imidization catalyst. Examples of the imidization catalyst include aliphatic amines such as tripropylamine, dibutylpropylamine and ethyldibutylamine; Alicyclic amines (monocyclic) such as N-ethylpiperidine, N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroazepine; Alicyclic amines (polycyclic) such as azabicyclo[2.2.1]heptane, azabicyclo[3.2.1]octane, azabicyclo[2.2.2]octane, and azabicyclo[3.2.2]nonane; And pyridine, 2-methylpyridine (2-picoline), 3-methylpyridine (3-picoline), 4-methylpyridine (4-picoline), 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine And aromatic amines such as 2,4-dimethylpyridine, 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and isoquinoline. . Moreover, it is preferable to use an acid anhydride with an imidation catalyst from a viewpoint which is easy to accelerate an imidation reaction. Examples of the acid anhydride include conventional acid anhydrides used for imidization reaction, 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 polyimide-based resin and the polyamide-based resin are isolated by conventional methods such as separation means such as filtration, concentration, extraction, crystallization, recrystallization, and column chromatography, or separation means combining them. (I) (separate purification) may be carried out, and in a preferred embodiment, a large amount of alcohol such as methanol is added to the reaction solution containing the transparent polyamideimide resin to precipitate the resin, followed by concentration, filtration and drying. Can be isolated.

<Filler>

In the optical laminate of the present invention, the optical film may include at least one filler. Examples of the filler include organic particles, inorganic particles, and the like, and preferably inorganic particles. Examples of the inorganic particles include metal oxide particles such as silica, zirconia, alumina, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, and cerium oxide, and metals such as magnesium fluoride and sodium fluoride. Fluoride particles, etc. may be mentioned, and among these, silica particles, zirconia particles, and alumina particles are preferable from the viewpoint of increasing the elastic modulus and/or tear strength of the obtained optical film and improving impact resistance. And more preferably silica particles. These fillers may be used alone or in combination of two or more.

In the optical laminate of the present invention, the optical film may include at least one filler having an average primary particle diameter of 5 to 35 nm, for example. In addition to having high optical properties, such an optical film also has a high tensile modulus. The tensile elastic modulus of the optical film is preferably 4,000 MPa or more, more preferably 5,000 MPa or more, still more preferably 5,500 MPa or more, particularly preferably 6,000 MPa or more. When the tensile modulus of elasticity is more than the above lower limit, defects such as pitting are less likely to occur in the optical film, and the strength of the optical film is easily increased, and durability is easily improved. The tensile modulus of elasticity is preferably 10,000 MPa or less, more preferably 9,000 MPa or less. If the tensile modulus is less than or equal to the above upper limit, it is easy to improve the bending resistance of the optical film. In addition, the tensile modulus of the optical film can be measured according to JIS K 7127 at room temperature using a tensile tester. From the viewpoint of easily increasing the homogeneity, transparency, modulus, and strength of the optical film, the average primary particle size of the filler is preferably 10 nm or more, more preferably 15 nm or more, and even more preferably 20 nm or more. In addition, from the viewpoint of easily increasing the transparency of the optical film, the average primary particle size of the filler is preferably 30 nm or less.

The average primary particle size of the filler can be measured by the BET method. Specifically, the specific surface area (BET specific surface area) measured by the BET method (nitrogen adsorption BET method) can be calculated in terms of an average primary particle diameter. Here, if the average primary particle size is d (nm), the density of the filler is ρ (g/cm ³ ), and the BET specific surface area is S (m ² /g), between them, d=6000/ The relationship of (S×ρ) is established. For example, when the filler is silica, the average primary particle diameter can be calculated from the BET specific surface area from the formula d=2070/S. Further, the primary particle diameter (average primary particle diameter) may be measured by image analysis of a transmission electron microscope (TEM) or a scanning electron microscope (SEM). The average primary particle diameter of the filler contained in the optical film may be the average primary particle diameter of the filler used as a raw material, or may be the average primary particle diameter measured from the optical film. When the average primary particle diameter of the filler is measured from the optical film, the average primary particle diameter of the filler in the optical film may be measured by image analysis of a transmission electron microscope or a scanning electron microscope using the film as a measurement sample. If necessary, the pulverized and crushed film is dissolved in a soluble solvent (for example, γ-butyrolactone) in the resin in the film, and the dispersed particles are transmitted through a transmission electron microscope (TEM) or scanning electron microscope ( Observation by SEM) may be performed, the filler may be taken out from the film, dried, and the average primary particle diameter may be calculated from the BET specific surface area in the same manner as above. When the average primary particle is measured by, for example, image analysis of an electron microscope, the average value of the result of measuring the primary particle diameter for each of the 100 particles present in a certain area may be the average primary particle diameter.

The content of the filler is preferably 0.5% by mass or more, more preferably 1% by mass or more, more preferably 5% by mass or more, further preferably 10% by mass or more, and more preferably with respect to the mass of the optical film. Is 15% by mass or more, more preferably 20% by mass or more, more preferably 25% by mass or more, particularly preferably 30% by mass or more. When the content of the filler is more than the above lower limit, it is easy to improve the impact resistance and durability of the optical film. The content of the filler is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less, based on the mass of the optical film. When the content of the filler is less than or equal to the above upper limit, the haze and yellowness of the optical film are easily reduced, and the transparency and optical properties are easily improved, and the bending resistance is easily improved.

<Ultraviolet absorbent>

The optical laminate of the present invention may contain at least one ultraviolet absorber. The ultraviolet absorber can be appropriately selected from those commonly used as ultraviolet absorbers in the field of resin materials. The ultraviolet absorber may contain a compound that absorbs light having a wavelength of 400 nm or less. Examples of the ultraviolet absorber include at least one compound selected from the group consisting of benzophenone-based compounds, salicylate-based compounds, benzotriazole-based compounds, and triazine-based compounds. The ultraviolet absorbers may be used alone or in combination of two or more. Since the deterioration of the resin is suppressed by the optical film containing an ultraviolet absorber, visibility can be improved when the optical film of the present invention is applied to an image display device or the like. In the present specification, the "system compound" refers to a derivative of a compound to which the "system compound" is added. For example, the term "benzophenone-based compound" refers to a compound having a benzophenone as a parent skeleton and a substituent bound to benzophenone.

In the optical laminate of the present invention, when the optical film contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.01 to 10 parts by mass, more preferably 1 to the mass of the resin contained in the optical film. It is -8 mass parts, More preferably, it is 2-7 mass parts. When the content of the ultraviolet absorber is more than the above lower limit, it is easy to improve the ultraviolet absorbency. When the content of the ultraviolet absorber is equal to or less than the above upper limit, decomposition of the ultraviolet absorber due to heat at the time of manufacturing the substrate can be suppressed, and thus it is easy to improve the optical properties and to reduce haze, for example.

<Other additives>

The optical laminate of the present invention may further contain additives other than fillers and ultraviolet absorbers. Examples of the other additives include colorants such as antioxidants, mold release agents, stabilizers, and blueing agents, flame retardants, pH adjusters, silica dispersants, lubricants, thickeners, and leveling agents. When other additives are contained, the content may be preferably 0.005 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, and even more preferably 0.1 to 10 parts by mass relative to the mass of the optical film.

<Functional layer>

The optical laminate of the present invention has an optical film and a functional layer laminated on at least one side of the optical film. The function of the functional layer is not particularly limited, and hard coating function, antistatic function, anti-glare function, low reflection function, antireflection function, antifouling function, gas barrier function, primer function, electromagnetic wave shielding function, undercoat function, ultraviolet absorption A general function employed in the optical film, such as a function, an adhesion function, and a color adjustment function, may be used. The functional layer may be a layer having one type of function, or a layer having two or more types of functions. From the viewpoint of being easy to use as a front panel of a flexible display device, at least one of the functional layers is at least one selected from the group consisting of a hard coating function, an antistatic function, an anti-glare function, a low reflection function, an antireflection function and an antifouling function. It is preferably a layer having the function of. The functional layer may have a plurality of functions as a single layer, or two or more layers having a layer having each function may be stacked. When laminating two or more layers, the order of lamination is appropriately set depending on the function. These layers are laminated on one side or both sides of the optical film. When laminated on both sides, the thickness, function, and order of lamination of the layers laminated on each side may be the same or different.

The thickness of the functional layer may be appropriately set depending on the intended function, but from the viewpoint of easy weight reduction and high optical homogeneity of the optical laminate, preferably 20 μm or less, more preferably 15 μm or less, and more preferably It is 10 micrometers or less.

(Hard coating function)

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

A polyfunctional (meth)acrylate-based compound is a compound having at least two acryloyloxy groups and/or methacryloyloxy groups in a molecule, specifically, ethylene glycol di(meth)acrylate, diethylene glycol di (Meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, tetra Methylolmethanetri(meth)acrylate, tetramethylolmethanetetra(meth)acrylate, pentaglycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerin tree (Meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritolpenta(meth)acrylate, dipentaerythritolhexa(meth)acrylate, tris((meth) Acryloyloxyethyl)isocyanurate, a phosphazene acrylate compound or a phosphazene methacrylate compound in which a (meth)acryloyloxy group is introduced into the phosphazene ring of the phosphazene compound, at least two of the molecules Urethane (meth)acrylate compound obtained by reaction of a polyisocyanate having an isocyanate group with a polyol compound having at least one (meth)acryloyloxy group and a hydroxyl group, at least two carboxylic acid halides and at least one ( And polyester (meth)acrylate compounds obtained by reaction with a polyol compound having a meta)acryloyloxy group and a hydroxyl group, and oligomers such as dimers and trimers of the above-mentioned compounds.

You may use these compounds individually or in mixture of 2 or more types. In addition, at least one monofunctional (meth)acrylate may be used in addition to the polyfunctional (meth)acrylate-based compound. As monofunctional (meth)acrylate, for example, hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylic Rate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycidyl (meth)acrylate, and the like. These compounds are used alone or in combination of two or more. The content of the monofunctional (meth)acrylate-based compound is preferably 10% by mass or less with respect to the solid content of the compound contained in the composition for forming a functional layer (paint for a hard coating layer). In addition, in this specification, solid content means all the components except the solvent contained in a curable composition.

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

The active energy ray-curable compound may be used in the form of a solution mixed with a solvent. The active energy ray-curable compound and its solution may be commercially available as a hard coating agent. As a commercially available hard coating agent, specifically, "NK hard M101" (Shin-Nakamura Chemical Co., Ltd., urethane acrylate compound), "NK ester A-TMM-3L" (Shin-Nakamura Chemical Co., Ltd., tetramethyl All methane triacrylate), ``NK ester A-9530'' (Shin-Nakamura Chemical Co., Ltd., dipentaerythritol hexaacrylate), ``KAYARAD (registered trademark) DPCA series'' (Nippon Kayaku Co., Ltd., D Derivatives of pentaerythritol hexaacrylate compound), ``Aronix (registered trademark) M-8560'' (Toagosei Co., Ltd., polyester acrylate compound), ``New Frontier (registered trademark) TEICA'' (Daiichi Pharmaceutical Co., Ltd.) Tris(acryloyloxyethyl)isocyanurate), "PPZ" (made by Kyoeisa Chemical Co., Ltd., a phosphazene methacrylate compound), etc. are illustrated.

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

As a method of laminating a hard coating layer on at least one side of an optical film, for example, a composition for forming a hard coating layer containing an active energy ray-curable compound (active energy ray-curable resin) is applied to the surface of a substrate (optical film), thereby Just irradiate the energy rays. Such a composition can be obtained by mixing the active energy ray-curable compound with an additive or the like as necessary. The cured product of the composition for forming the hard coat layer constitutes the hard coat layer.

It is preferable that the composition for forming a hard coat layer contains a solvent, and in the composition for forming the hard coat layer, it is preferable that the active energy ray-curable compound is diluted with a solvent. In this case, the composition may be prepared by mixing the active energy ray-curable compound with various additives (for example, silicone oil, etc.) for imparting surface smoothness, etc., and then diluting the obtained mixture with a solvent. After diluting with a solvent, the additives may be prepared by mixing, and the active energy ray-curable compound may be prepared by mixing an additive diluted with a solvent in advance, or the active energy ray-curable compound previously diluted with a solvent and the additive diluted with a solvent in advance. You may mix and manufacture. The composition after mixing may be further stirred.

From the viewpoint of facilitating application, it is preferable that the composition for forming a hard coat layer contains a suitable solvent. Examples of the solvent include aliphatic hydrocarbons such as hexane and octane, aromatic hydrocarbons such as toluene and xylene, alcohols such as ethanol, 1-propanol, isopropanol and 1-butanol, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate, It can be appropriately selected from esters such as butyl acetate and cellosolves. You may mix and use these organic solvents as needed. From the viewpoint of easily heating the composition for forming the hard coat layer after coating and evaporating the organic solvent, the boiling point of the solvent is preferably in the range of 70°C to 200°C. The type and amount of the solvent is appropriately selected according to the type and amount of the active energy ray-curable compound used, the material, shape, coating method of the base material (optical film), thickness of the target hard coating layer, and the like.

The temperature (T1) of heating and drying the composition for forming the hard coat layer is preferably ±30°C, more preferably ±20°C, with respect to the boiling point (T2) of the solvent contained in the composition. When T1 is in the above range, it is difficult to remain in the hard coating layer from which a solvent is obtained, and there is a tendency that adhesiveness is hardly lowered.

The solid content of the composition for forming a hard coat is preferably 5 to 60% by mass, more preferably 10 to 55% by mass, more preferably 20 to 50% by mass, even more preferably 25 to 50% by mass. When the said solid content is in the said range, since the film thickness to coat is not too thick, and the value of Formula 1 does not become too large, visibility becomes favorable, and the smoothness of the surface of the obtained hard coating layer tends to become favorable.

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

Examples of the photopolymerization initiator include acetophenone, acetophenone benzyl ketal, anthraquinone, 1-(4-isopropylphenyl-2-hydroxy-2-methylpropan-1-one, carbazole, xanthone, 4-chloro Benzophenone, 4,4'-diaminobenzophenone, 1,1-dimethoxydioxybenzoin, 3,3'-dimethyl-4-methoxybenzophenone, thioxanthone, 2,2-dimethoxy-2 -Phenylacetophenone, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino Propan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one , Fluorenone, fluorene, benzaldehyde, benzoinethyl ether, benzoisopropyl ether, benzophenone, myhila ketone, 3-methylacetophenone, 3,3',4,4'-tetra tert-butylperoxycarbonyl Benzophenone (BTTB), 2-(dimethylamino)-1-[4-(morpholinyl)phenyl]-2-phenylmethyl)-1-butanone, 4-benzoyl-4'-methyldiphenylsulfide, benzyl And the like. Moreover, a photoinitiator may be used in combination with a dye sensitizer. Examples of the dye sensitizer include xanthene, thioxanthene, coumarin, and ketocoumarin. Examples of the combination of the photopolymerization initiator and the dye sensitizer include a combination of BTTB and xanthene, a combination of BTTB and thioxanthene, a combination of BTTB and coumarin, a combination of BTTB and ketocoumarin, and the like. have.

When a photopolymerization initiator is used, the amount used is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the active energy ray-curable compound. When the amount used is in the above range, it tends to be easy to obtain a sufficient curing rate. Moreover, the usage-amount of a photoinitiator is per 100 mass parts of active energy ray-curable compounds, Preferably it is 10 mass parts or less.

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

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

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

Examples of the conductive particles include particles such as indium-tin-composite oxide (ITO) and antimony-doped tin oxide.

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

The anion portion of the alkali metal salt may be composed of an organic substance or an inorganic substance. As no moiety constituting the organic salts, for ^{_{example, CH 3 COO -, CF 3}} COO -, CH 3 SO 3 -, CF 3 SO 3 -, (CF 3 SO 2) 3 C -, C 4 F 9 SO ^{_{3 -, C 3 F 7 COO}} -, (CF 3 SO 2) (CF 3 CO) N -, (FSO 2) 2 N -, - O 3 S (CF 2) 3 SO 3 -, CO 3 2-, Expression (A1) to Expression (A4),

_{(A1): 2 N (C} n F 2n + 1 SO 2) - (n is an integer of 1-10),

_{(A2): CF 2 (C} m F 2m SO 2) 2 N - (m is an integer of 1-10),

_{^{(A3): - O 3 S}} (CF 2) l SO 3 - (l is an integer of 1-10),

_{(A4): (C p F} 2p + 1 SO 2) N - (C q F 2q + 1 SO 2), ( single, p and q are, independently of each other, an integer of 1-10),

The anion portion represented by is used. In particular, the anion portion containing a fluorine atom is preferably used in that an ion compound having good ion dissociation properties is obtained. As no moiety constituting the inorganic ^{salts, Cl -, Br -, I} -, AlCl 4 -, Al 2 Cl 7 -, BF 4 -, PF 6 -, ClO 4 -, NO 3 -, AsF 6 -, SbF 6 _{^{-, NbF 6 -, TaF 6}} -, (CN) 2 N - or the like is used. No Examples ^{_{moiety, (FSO 2) 2 N -}} , (CF 3 O 2) 2 N -, (C 2 F 5 SO 2) 2 N - is preferable, and ^{_{(FSO 2) 2 N -,}} (CF 3 SO 2 ) ₂ N ^- is more preferred.

The organic cation-anion salt is composed of a cation portion and an anion portion, and the cation portion is an organic salt that is an organic substance. The anion portion may be an organic substance or an inorganic substance. "Organic cation-anion salt" may be a substance called an ionic liquid or an ionic solid.

As a cation component, specifically, a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, a cation having a pyrrole skeleton, an imidazolium cation, tetrahydropyri Midium cation, dihydropyrimidinium cation, pyrazolium cation, pyrazolium cation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation, and the like. As an anion component, the thing similar to the anion part of the said alkali metal salt is mentioned. Especially, an anion component containing a fluorine atom is preferably used in that an ion compound having good ion dissociation properties is obtained.

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

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

Thereafter, by irradiating the active energy ray, the active energy ray-curable compound coated on the surface of the optical film is cured to obtain a target hard coating layer. Examples of the active energy ray include electron beams, ultraviolet rays, and visible rays, and are appropriately selected according to the type of active energy ray-curable compound used. The active energy ray may be irradiated in the same way as in the formation of a normal hard coat layer. The intensity, irradiation time, etc. of the active energy ray to be irradiated are appropriately selected depending on the type of the curable compound used, the thickness of the layer containing the curable compound, and the like. The active energy ray may be irradiated in an inert gas atmosphere. In order to irradiate active energy rays in a nitrogen atmosphere, active energy ray irradiation may be performed, for example, in a container sealed with an inert gas, and nitrogen gas, argon gas, or the like can be used as the inert gas.

It is also useful to additionally laminate an antireflection layer or a low reflection layer, which will be described later, on the surface of the hard coat layer. In this case, the antireflection layer or the low reflection layer can be laminated on the surface of the hard coating layer as a single layer or as a multilayer.

(Antistatic function)

The antistatic function is a function for preventing the charging of the surface of the optical film. In the optical laminate of the present invention, the functional layer may be a layer having an antistatic function (antistatic layer). As a method of forming an antistatic layer, in addition to a method of adding an antistatic agent to the hard coating layer forming composition to impart an antistatic function to the hard coating layer, the composition for forming an antistatic layer obtained by diluting an antistatic agent with a solvent, etc. Alternatively, a method of coating a functional layer laminated on an optical film, drying it as necessary, and forming it as a single film may be mentioned. The antistatic agent may be included as a structural unit having an antistatic function in a part of the resin constituting the functional layer (for example, a cured product of the active energy ray-curable compound described above), and in the resin forming the functional layer , It may be added as an additive. When an antistatic agent is added as an additive, the amount of the addition is preferably 0.01 to 20% by mass, more preferably 0.05 to 10% by mass, and even more preferably 0.1 to 10% based on the solid content of the composition for forming a functional layer. It is mass%.

(Anti-glare function)

The anti-glare function is a function of preventing the reflection of external light by scattering and reflecting light. In the optical laminate of the present invention, the functional layer may be a layer having an anti-glare function (anti-glare layer). As the anti-glare layer, a known one can be appropriately employed. For example, an anti-glare function may be imparted by forming a layer having a fine concavo-convex shape on the surface by using a resin composition containing one or more kinds of translucent fine particles in a translucent resin. More specifically, such an anti-glare layer is coated with, for example, a light-transmissive resin solution in which light-transmitting fine particles as a filler are dispersed on an optical film, and the light-transmitting fine particles are convex on the surface of the anti-glare layer. It can be formed by adjusting the thickness. In addition, in this specification, "transmittance" means that light can transmit substantially regardless of the presence or absence of scattering inside the substance.

Light-transmitting fine particles

Examples of the light-transmitting fine particles include (meth)acrylic resins, melamine resins, polyethylene resins, polystyrene resins, polycarbonate resins, vinyl chloride resins, organic silicone resins, organic fine particles such as acrylic-styrene copolymers, and calcium carbonate, And inorganic fine particles such as silica, aluminum oxide, barium carbonate, barium sulfate, titanium oxide, and glass. As the translucent fine particles, one type or two or more types of fine particles may be used. In order to obtain a desired anti-glare property, the type of light-transmitting fine particles, particle diameter, refractive index, content, etc. are appropriately adjusted.

The particle diameter of the translucent fine particles is preferably 0.5 to 5 μm, more preferably 1 to 4 μm. When the particle diameter of the light-transmitting fine particles is within the above range, it is easy to obtain a necessary light diffusion effect, and also, since it is easy to form irregularities on the surface of the anti-glare layer, it is easy to obtain a sufficient anti-glare effect. Moreover, the surface shape of the anti-glare layer is not rough, and the haze value tends not to increase significantly.

The difference in refractive index between the translucent fine particles and the translucent resin is preferably 0.02 to 0.2, and more preferably 0.04 to 0.1. When the refractive index difference is within the above range, a sufficient light diffusion effect is easily obtained, and the entire optical laminate is difficult to whiten.

The added amount of the light-transmitting fine particles is preferably 3 to 30 parts by mass, more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the translucent resin. When the amount added is within the above range, a sufficient light diffusion effect is easily obtained, and the entire optical laminate is difficult to whiten.

When the particle size, addition amount, and/or the refractive index difference between the light-transmitting fine particles and the light-transmitting resin is adjusted within the above range, even when the haze of the anti-glare layer is high, the transparency of the surface is not reduced and the glare on the surface is reduced. It is easy to prevent, and furthermore, it is easy to prevent glare while maintaining high transmittance and clarity even in areas with low haze.

Translucent resin

The light-transmitting resin constituting the anti-glare layer is not particularly limited as long as it has light-transmitting properties. For example, a cured product of a thermosetting resin other than a cured product of the active energy ray-curable compound as described above; Thermoplastic resins; And metal alkoxide-based polymers. Among them, a cured product of an active energy ray-curable compound is preferred. When an ultraviolet curable resin or the like is used as the active energy ray-curable compound, as in the above, a photopolymerization initiator (radical polymerization initiator) may be contained in the coating solution, and the coating layer is cured by irradiating the active energy ray.

Examples of the thermosetting resin include thermosetting urethane resins composed of acrylic polyols and isocyanate prepolymers, phenol resins, urea melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins.

Examples of the thermoplastic resin include cellulose derivatives such as acetyl cellulose, nitrocellulose, acetylbutyl cellulose, ethyl cellulose, and methyl cellulose; Vinyl resins such as vinyl acetate and its copolymers, vinyl chloride and its copolymers, vinylidene chloride and its copolymers; Acetal resins such as polyvinyl formal and polyvinyl butyral; (Meth)acrylic resins such as acrylic resins and copolymers thereof, methacrylic resins and copolymers thereof; Polystyrene-based resins; Polyamide resins; Polyester resins; And polycarbonate resins.

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

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

In addition, generally, the refractive index of the ultraviolet curable resin is about 1.5, which is about the same as that of glass, but in comparison with the refractive index of the translucent fine particles, the refractive index of the ultraviolet curable resin used may be low. In this case, in the translucent resin, TiO ₂ (refractive index; 2.3 to 2.7), Y ₂ O ₃ (refractive index; 1.87), La ₂ O ₃ (refractive index; 1.95), ZrO ₂ (refractive index; 2.05), which are fine particles having high refractive index, Al ₂ O ₃ (refractive index; 1.63) or the like can be added to such an extent that the diffusibility of light in the anti-glare layer can be maintained, and the refractive index of the transmissive resin can be increased and adjusted to a preferred range.

The composition for forming an anti-glare layer can be prepared by dispersing light-transmitting fine particles in a composition containing a light-transmitting resin and a solvent (for example, the composition for forming the hard coating layer). The timing and dispersing method for dispersing the translucent fine particles are not particularly limited.

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

As another method of forming the antiglare layer, an embossing treatment can be used. In this method, after coating the composition for forming the anti-glare layer on the optical film or the functional layer laminated on the optical film, while pressing the mold (embossing roll) having a predetermined surface concavo-convex shape on the coating layer, the coating layer is applied as necessary. It can be hardened to impart unevenness to the surface of the coating layer. After peeling off the anti-glare layer from the embossing roll, it is also effective to perform a second curing step of irradiating ultraviolet rays once more from the anti-glare layer side for the purpose of further promoting the curing reaction of the anti-glare layer.

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

The anti-glare layer may contain an antistatic agent. By containing an antistatic agent, an anti-glare layer having an antistatic function can be obtained. As an antistatic agent, the thing similar to the antistatic agent added to the above-mentioned hard coating layer is mentioned.

The anti-glare layer may have a low-reflection layer on its outermost surface, that is, the uneven surface side. Although a sufficient anti-glare function is exhibited even in the absence of a low-reflection layer, the anti-glare property can be further improved by providing a low-reflection layer on the outermost surface. As the low-reflection layer, those described later can be applied.

(Anti-reflection function and low-reflection function)

The antireflection function and the low reflection function are functions to prevent or reduce reflection of external light. In the optical laminate of the present invention, the functional layer may be a layer having a function of preventing reflection of external light (antireflection layer) or a layer having a function of reducing reflection of external light (low reflection layer). The antireflection layer and the low reflection layer may be a single layer or a multilayer.

Anti-reflection layer

The antireflection layer may include a low refractive index layer. Further, the antireflection layer may be a layer having a multilayer structure further comprising a low refractive index layer and a high refractive index layer and/or a medium refractive index layer laminated between the low refractive index layer and the optical film. Between the antireflection layer and the optical film, a hard coating layer as described above may be provided.

The thickness of the antireflection layer is preferably 0.01 to 1 μm, and more preferably 0.02 to 0.5 μm. As the antireflection layer, a low refractive index layer having a refractive index (for example, a refractive index of 1.3 to 1.45) smaller than that of the optical film or functional layer on which the antireflection layer is laminated; The layer etc. which laminated|stacking the low refractive index layer of the thin film which consists of an inorganic compound and the high refractive index layer of the thin film which consists of an inorganic compound alternately are mentioned. Here, the refractive index of the high-refractive-index layer may be greater than that of the low-refractive-index layer, but it is preferably 1.60 or more.

The material forming the low-refractive-index layer is not particularly limited as long as it is a material having a low refractive index. For example, resin materials such as active energy ray-curable resins (for example, ultraviolet curable acrylic resins), hybrid materials in which inorganic fine particles such as colloidal silica are dispersed in resins, and sols using metal alkoxides such as tetraethoxysilane -Gel materials and the like. The material forming these low-refractive-index layers may be a polymer that has been polymerized or a monomer or oligomer that becomes a precursor. Moreover, since the material constituting the antireflection layer can impart an antifouling function to the antireflection layer, it is preferable to contain a compound containing fluorine.

The high-refractive-index layer is coated with a cured product of the above-mentioned active energy ray-curable resin or a translucent resin such as a metal alkoxide-based polymer, and a coating solution containing inorganic fine particles and/or organic fine particles, followed by curing the coating layer as necessary. It can be formed by a method. Examples of the inorganic fine particles include zinc oxide, titanium oxide, cerium oxide, aluminum oxide, silane oxide, tantalum oxide, yttrium oxide, ytterbium oxide, zirconium oxide, antimony oxide, and indium tin oxide (ITO). The high refractive index layer containing these inorganic fine particles can also have an antistatic function.

As a method of manufacturing a multilayer film in which transparent thin films of inorganic compounds (metal oxides, etc.) having different refractive indexes are laminated, as a sol/gel method of metal compounds such as chemical vapor deposition (CVD), physical vapor deposition (PVD), and metal alkoxide After forming the colloidal metal oxide particle coating, post-treatment (ultraviolet irradiation: Japanese Laid-Open Patent Publication No. Hei 9-157855, plasma treatment: Japanese Laid-Open Patent Publication No. 2002-327310) and a method of forming a thin film may be mentioned. .

On the other hand, from the viewpoint of easy to improve the productivity, it is also preferable to laminate the thin film obtained by dispersing the inorganic particles in the matrix to laminate the antireflection layer. In addition, by coating a composition for forming an antireflection layer in which inorganic particles are dispersed in a matrix, when the antireflection layer is laminated, it is also possible to impart an antiglare function to the antireflection layer by forming a fine concavo-convex shape on the coated surface.

Low reflective layer

The low-reflection layer is a layer formed of a low-refractive-index material having a lower refractive index than the optical film serving as the substrate. The low-refractive-index layer is formed by coating a coating solution containing a light-transmitting resin such as a cured product of the active energy ray-curable resin or a metal alkoxide polymer and inorganic fine particles, and then curing the coating layer as necessary. can do. As such a low refractive index material, specifically, inorganic material fine particles such as lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), aluminum fluoride (AlF ₃ ), and cryolite (3NaF·AlF ₃ or Na ₃ AlF ₆ ) , An inorganic low-reflection material contained in an acrylic resin or an epoxy resin; And organic low-reflection materials such as fluorine-based or silicone-based organic compounds, thermoplastic resins, thermosetting resins, and ultraviolet curable resins.

(Antifouling function)

The antifouling function is a function for preventing contamination, and is a function obtained by imparting water repellency, oil repellency, cold resistance, antifouling properties, and anti-fingerprint properties to the layer. In the optical laminate of the present invention, the functional layer may be a layer having an antifouling function (antifouling layer). The material for forming the antifouling layer may be an organic compound or an inorganic compound. Fluorine-containing organic compounds, organosilicon compounds, and the like are mentioned as materials that cause high water repellency and oil repellency. Examples of the fluorine-containing organic compound include fluorocarbon, perfluorosilane, and these polymer compounds. From the viewpoint of easily increasing the anti-fouling effect, a material such that the contact angle of the surface of the antifouling layer with respect to pure water is 90 degrees or more, and more preferably 100 degrees or more, is preferable. As a method of forming the antifouling layer, depending on the material to be formed, physical vapor deposition, chemical vapor deposition, wet coating, or the like, which are representative examples of vapor deposition or sputtering, can be used. The average thickness of the antifouling layer is usually about 1 to 50 nm, preferably 3 to 35 nm.

(Ultraviolet absorption function)

In the optical laminate of the present invention, the functional layer may be an ultraviolet absorbing layer having a function of absorbing ultraviolet rays. The ultraviolet absorbing layer is composed of, for example, a main material selected from an ultraviolet curable translucent resin, an electron beam curable translucent resin, and a thermosetting translucent resin, and an ultraviolet absorber dispersed in the main material.

(Adhesive function)

In the optical layered product of the present invention, the functional layer may be an adhesive layer having the adhesive function of adhering the optical film to other members. As a material for forming the adhesive layer, a commonly known one can be used. For example, a thermosetting resin composition or a photocurable resin composition can be used. In this case, the thermosetting resin composition or the photocurable resin composition can be polymerized and cured by supplying energy afterwards.

The adhesive layer may be a layer attached to an object by pressing, called a pressure sensitive adhesive (PSA). The pressure-sensitive adhesive may be an adhesive that is ``substance having tackiness at room temperature and adhered to an adherend at light pressure'' (JIS K 6800), and ``contains a specific component in a protective film (microcapsule), suitable for It may be a capsule adhesive, which is an adhesive capable of maintaining stability until the film is destroyed by means (pressure, heat, etc.) (JIS K 6800).

(Color adjustment function)

In the optical layered product of the present invention, the functional layer may be a color adjustment layer having a function of adjusting the optical layered product to a desired color. The color adjustment layer is, for example, a layer containing a resin and a colorant. Examples of the colorant include inorganic pigments such as titanium oxide, zinc oxide, bengala, titanium oxide-based plastic pigments, ultramarine, cobalt aluminate, and carbon black; Organic pigments such as azo-based compounds, quinacridone-based compounds, anthraquinone-based compounds, perylene-based compounds, isoindolinone-based compounds, phthalocyanine-based compounds, quinophthalone-based compounds, styrene-based compounds, and diketopyrrolopyrrole-based compounds; Extender pigments such as barium sulfate and calcium carbonate; And dyes such as basic dyes, acid dyes, and mordant dyes.

<Method of manufacturing an optical laminate>

The method for producing the optical laminate of the present invention having the above characteristics is not particularly limited, for example, the following steps:

(a) a step of applying a varnish containing at least a polyimide-based resin and/or a polyamide-based resin and a solvent on a support and drying it to form a coating film,

(b) peeling the coating film from the support,

(c) heating the peeled coating film to obtain a film, and

(d) a step of laminating a functional layer on at least one side of the film to obtain an optical laminate

It can be manufactured by a production method comprising at least. The present invention also provides a method of manufacturing an optical laminate, which includes at least the above steps.

The manufacturing method of the optical laminated body of this invention is after process (c) or after process (d),

(e) The line profiles in directions h and v, which are orthogonal to each other, on the film inverse space obtained by Fourier transforming the projected image obtained by the projection method using the obtained film or optical laminate, respectively, are the line profile h and the line profile, respectively. v, and the line profiles in the directions h'and v'which are orthogonal to each other in the background inverse space obtained by Fourier transforming the background image obtained without using the film or the optical laminate in the above projection method, respectively. The line profile h'and the line profile _v'are called, and the maximum intensity of the line profile (h-h') obtained by subtracting the line profile h'from the line profile h is called Y _mh , and the frequency representing the maximum intensity Y _mh is X _mh. Y _mh and Y when the maximum intensity of the line profile (v-v') obtained by subtracting the line profile v'from the line profile v is Y _mv , and the frequency representing the maximum intensity Y _mv is X _mv . _The process of evaluating a film based on the value of _mv and the value of (Y _mh +Y _mv )/(X _mh +X _mv ) ^1/2 calculated from Y _mh , Y _mv , X _mh and X _mv

You may further include.

The varnish used in the above step (a) contains at least a polyimide resin and/or a polyamide resin and a solvent. Here, the viscosity (cps) of the varnish and the solid content concentration (mass %) of the varnish are as follows:

It is desirable to meet.

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

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

The varnish can be prepared by mixing and stirring the resin, a solvent, and an ultraviolet absorber, a filler, and other additives used as necessary. For example, a reaction solution of a polyimide-based resin or a polyamide-based resin obtained by reacting the above-described dicarboxylic acid compound, tetracarboxylic acid compound, and/or diamine compound, and other raw materials described above is a solvent and a case If necessary, the varnish may be prepared by mixing with other additives and stirring. The varnish may be prepared by isolating a polyimide-based resin or a polyamide-based resin from a reaction solution and mixing with a solvent or the like, or by purchasing a solution or solid of a polyimide-based resin or a polyamide-based resin, and mixing with a solvent and the like as necessary. By doing so, the varnish may be prepared. In addition, when using silica as a filler, the varnish may be prepared by using a silica sol obtained by dispersing a dispersion of silica sol containing silica with a solvent in which the resin is soluble, for example, a solvent used in the preparation of the following varnish. do.

The viscosity (cps) of the varnish prepared as described above and the solid content concentration (mass%) of the varnish are not particularly limited, but from the viewpoint of easy to obtain an optical laminate having excellent optical homogeneity, these are the following relationships:

It is desirable to meet. Here, the viscosity (cps) of the varnish is measured at 25°C using an E-type viscometer according to JIS K 8803:2011. In addition, the solid content concentration of the varnish indicates the concentration (mass %) of the resin, filler, and additives contained in the varnish, and is calculated from the mass of the solid content contained in the varnish based on the total mass of the varnish. The product of the viscosity of the varnish represented by the formula and the solid content concentration of the varnish is preferably 3,000 or more, more preferably 3,500 or more from the viewpoint of easy to increase the optical homogeneity of the optical laminate. Although the upper limit of the product of the viscosity of the varnish represented by the formula and the solid content concentration of the varnish is not particularly limited, from the viewpoint of handling the varnish, it is preferably 10,000 or less, more preferably 7,000 or less.

The viscosity of the varnish is preferably 5,000 to 60,000 cps, more preferably 10,000 to 50,000 cps, and more preferably 15,000 to 45,000 cps. When the viscosity of the varnish is more than the above lower limit, it is easy to obtain the effect of the present invention, and when it is less than the above upper limit, it is easy to improve the handling of the varnish.

The solid content concentration of the varnish is preferably 5 to 25% by mass, more preferably 10 to 23% by mass, and even more preferably 14 to 20% by mass. It is preferable from the viewpoint of obtaining a thick film that the solid content concentration of the varnish is equal to or greater than the above lower limit, and it is preferable from the viewpoint of easy handling of the varnish that it is below the upper limit.

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

The thickness of the support is not particularly limited, but is preferably 50 to 250 μm, more preferably 100 to 200 μm, and even more preferably 125 to 200 μm. When the thickness of the support is less than or equal to the above upper limit, it is preferable because it is easy to suppress the production cost of the film. In addition, it is preferable that the thickness of the support is equal to or more than the lower limit because it is easy to suppress curl of the film that may occur in the process of removing at least a part of the solvent. Here, the thickness of the support is measured by a contact-type film thickness meter or the like. From the viewpoint of easy to improve the surface quality of the optical laminate, and easy to manufacture the optical laminate of the present invention, the thickness distribution of the support is preferably ±3 μm or less, more preferably ± 2.5 μm or less, and more preferably Is ±2 μm or less. The thickness distribution of the support is measured by measuring the thickness in at least 20 places of the film according to the above-mentioned measuring method of the thickness, calculating the average thickness of the 20 places, and calculating from the difference between the thickness in each location and the average thickness. .

When applying the varnish on the support, you may apply to the support by a known coating method. As a 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, di And a ping method, a spraying method, and a flexible molding method.

Next, the coating film can be formed by drying the coating film of the varnish applied on the support. Drying is performed by removing at least a part of the solvent from the varnish coating film, and the drying method is not particularly limited. For example, drying may be performed by heating the coating film of the varnish applied on the support. In the following, drying in step (a) is also referred to as "first drying", and the coating film formed on the support after drying is also referred to as "dry coating". The dry coating film may be a coating film in which all of the solvent contained in the varnish is dried, or a coating film in a semi-dry state in which some solvents are dried. If necessary, the first drying may be performed under an inert atmosphere or under reduced pressure. It is preferable that the first drying is performed at a relatively low temperature over time. If the first drying is performed at a relatively low temperature for a long time, the values of Y _mh and Y _{mv in} the above formula are easily reduced, and the values of (Y _mh +Y _mv )/(X _mh +X _mv ) ^1/2 It is easy to lower, and it is easy to increase the optical homogeneity of the optical laminate.

In particular, when the optical layered product of the present invention is industrially produced, compared to the production environment at the laboratory level, the actual production environment is often disadvantageous to increase the optical homogeneity, and as a result, the optical homogeneity of the optical layered product. It may be difficult to increase. It is as described above that it is preferable to perform the first drying at a relatively low temperature over time, but at the laboratory level, when the first drying is performed, drying can be performed in a sealed dryer, so that optical lamination due to external factors The roughness of the surface of the sieve is relatively difficult to occur. On the other hand, in the case of industrially manufacturing an optical laminate, for example, because it is necessary to heat a large area in the first drying, a blower may be used during heating. As a result, the surface state of the optical film tends to be rough, making it difficult to increase the optical homogeneity of the film.

In the case of drying by heating, in consideration of the above external factors, particularly when industrially manufacturing the optical laminate, the heating temperature during the first drying is preferably 60 to 150°C, more preferably 60 to 130°C, more preferably 70 to 120°C. The time for the first drying is preferably 5 to 60 minutes, more preferably 10 to 40 minutes. The first drying may be performed under the conditions of one step or multiple steps, but it is preferable to perform under three or more stages of heating temperature conditions, especially considering the external factors described above when industrially manufacturing the optical laminate. When drying under conditions of multiple stages, preferably, in each stage, drying may be performed at the same or different temperature conditions and/or drying times, for example, 3 to 10 stages, preferably 3 to Drying may be performed under the conditions of step 8. When the first drying is performed under conditions of multiple stages, it is easy to increase the optical homogeneity of the optical laminate. In a preferred embodiment of the present invention in which the first drying is performed under conditions of three or more stages, it is preferable that the temperature profile of the first drying includes an elevated temperature and a reduced temperature. That is, it is more preferable that the drying conditions in the step (a) are heating temperature conditions of three or more stages in which the temperature profile includes elevated temperature and reduced temperature. As such a temperature profile, for example in the case of four steps, the temperature of the first drying is, in turn, 70 to 90°C (first temperature), 90 to 120°C (second temperature), and 80 to 120°C (third temperature) ) And 80 to 100°C (fourth temperature). In this example, the temperature of the first drying is raised from the first temperature to the second temperature, and then the temperature is decreased from the second temperature to the third temperature, and further from the third temperature to the fourth temperature. Here, the time for the first drying is 5 to 15 minutes in each step, for example. It is preferable to perform 1st drying so that the solvent residual amount of a dry coating film becomes 5-15 mass% with respect to the mass of a dry coating film, More preferably, it is 6-12 mass %. When the residual amount of the solvent is within the above range, it is easy to lower the values of Y _mh and Y _mv in the above formula of the optical film or optical laminate, (Y _mh +Y _mv )/(X _mh +X _mv ) ^{1/ It is} easy to lower the value of ² . Moreover, it is easy to improve peelability at the time of peeling a coating film from a support body in a process (b) continuously. As a result, it is easy to increase the optical homogeneity of the optical laminate. The residual amount of the solvent is lowered by increasing the drying temperature of each step and increasing the drying time. For this reason, it is possible to adjust the drying temperature and the drying time so that the residual amount of the solvent in the desired range can improve the optical homogeneity of the optical laminate.

Next, in the step (b), the dried coating film is peeled from the support. The peeling method is not particularly limited, and may be performed by moving the coating film while the support is fixed, and may be removed by moving the support while the coating film is fixed, and peeling may be performed by moving both the coating film and the support. You may do it.

Next, in step (c), an optical film can be obtained by heating the coating film peeled in step (b). The heating step in step (c) is also referred to as "second drying" or "post bake" in the following, and the coating film peeled in step (b) is also referred to as "peel coating film" below. In step (c), it is preferable to perform post-baking in a state in which the release coating film is stretched in the in-plane direction. The heating temperature during the second drying is preferably 150 to 300°C, more preferably 180 to 250°C, and even more preferably 180 to 230°C. The heating time in the second drying is preferably 10 to 60 minutes, more preferably 30 to 50 minutes. When the post-baking treatment is performed while the dry coating film is uniformly stretched in the in-plane direction, it is easy to lower the values of Y _mh and Y _mv in the above formula of the optical film or optical laminate, (Y _mh +Y _mv )/(X _mh +X _mv ) It is easy to decrease the value of ^1/2 .

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

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

For example, in the case of manufacturing an optical film by a roll-to-roll method, an optical film can be obtained by heating while conveying a long band-shaped coating film having a predetermined width. Here, in the case where heating is performed while applying tension to the coating film, the method is not limited, but, for example, each of the ends of the long strip-shaped film to be conveyed is gripped, respectively, while the gripped film is conveyed. Heat treatment is performed while setting the width to a predetermined distance, for example, while conveying the inside of the dryer. At this time, the ratio of the width of the film after the heat treatment (however, the gripping portion is not included in the width) to the width of the film before heat treatment (however, the gripping portions are not included in the width) is set to 1.1 or less, and the dryer It is preferable to perform the process (3) by releasing the gripping of the resin film from.

The ratio of the width of the film after the heat treatment (however, the gripping part is not included in the width) to the width of the film before the heat treatment (however, the gripping part is not included in the width) (hereinafter sometimes referred to as stretching ratio) , Preferably it is 0.70-1.10, More preferably, it is 0.80-1.05, More preferably, it is 0.85-1.03.

Gripping of the film is performed, for example, by using a plurality of clips.

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

In a plurality of clips provided at one end of the film, the space between the adjacent clips is, for example, 1 to 50 mm, preferably 3 to 25 mm, more preferably 5 to 10 mm. , Is installed.

In addition, when the straight line orthogonal to the film transport axis is aligned with the center of the grip portion of any clip at one end of the film, the intersection of the straight line with the other end of the film and the grip center of the clip closest to the intersection point The distance of can be preferably 3 mm or less, more preferably 2 mm or less, and more preferably 1 mm or less. When the said distance is in the said range, it is easy to improve the homogeneity of the film especially in left and right.

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

The amount of the solvent in the film after heat treatment, based on the mass of the film, is preferably 0.001 to 3% by mass, more preferably 0.001 to 2% by mass, still more preferably 0.001 to 1.5% by mass, particularly preferably 0.001 It is -1.3 mass %. When the amount of the solvent in the film after heat treatment is in the above range, the appearance of the optical film tends to be good.

When the heat treatment is over and the film comes out from the dryer, the film is released from gripping, and preferably immediately, the film end is slit. By performing a slit, cracks that are likely to occur between the gripping portion and the non-gripping portion at the end of the film are removed from the film, so that the film is conveyed thereafter and the temperature of the film is lowered. Magnification can be prevented in advance.

When the film exits the dryer, the film is rapidly cooled and shrinks, and cracks may occur. For this reason, it is preferable that there is a step of relaxing the film at a certain ratio from the dryer outlet to the position where the gripping of the film is released. The ratio is the width of the film coming out of the dryer (however, excluding the gripped width) (W) and the distance (F) at which the gripping part relaxes until the film is released from the dryer outlet, preferably 1.7≤F/ W×100≤6.9, more preferably 1.8≤F/W×100≤6.8, more preferably 1.9≤F/W×100≤6.7, even more preferably 2.0≤F/W×100≤6.7.

The distance at which one side relaxes with respect to the conveyance direction of the film is referred to as Fa, and the distance at which the other end relaxes is called Fb, and the sum of them is referred to as the relaxation distance F.

The distance from the dryer outlet to the release of the film is preferably 200 to 2,000 mm, more preferably 300 to 1,500 mm, more preferably 300 to 1,300 mm, even more preferably 300 to 1,000 mm. . When the distance is within the above range, cracks are unlikely to occur in the film, and there is a tendency that appearance defects such as sagging are less likely to occur.

Moreover, in the manufacturing method of this invention, from the viewpoint of being easy to manufacture the optical laminated body which has the said characteristic, after peeling a coating film from a support body in process (b), heating the peeled coating film in process (c) , To manufacture the film. However, the optical layered product of the present invention may be a film produced by any production method as long as the optical film or optical layered product has the characteristics relating to Y _mh and the like. For example, the film may be produced by post-baking the coating film before peeling the coating film from the support, and peeling the film after post-baking from the support.

Subsequently, in step (d), a functional layer is laminated on at least one side of the film to obtain the optical laminate of the present invention. As a method of laminating a functional layer on at least one side of the film, a method of laminating a composition for forming a functional layer on at least one side of the film, drying and/or curing as necessary, and laminating the film on at least one side of the film And a method of laminating and laminating functional layers. From the viewpoint of easily increasing the optical homogeneity of the optical laminate, it is preferable to coat the composition for forming a functional layer and to laminate the functional layers.

The manufacturing method of this invention may further include the process (e) of evaluating the film or optical laminated body mentioned later after the said process (c) or after (d). In the step (e), the line profiles in the direction h and the direction v orthogonal to each other in the film inverse space on the film inverse space obtained by Fourier transforming the projected image obtained by the projection method using the obtained film or optical laminate, respectively, are the line profile h. And a line profile v, and a line in a direction h'and a direction v'orthogonal to each other on a background inverse space obtained by Fourier transforming a background image obtained without using the film or the optical laminate in the projection method. The profile is called a line profile h'and a line profile v', respectively, and the maximum intensity of the line profile (h-h') obtained by subtracting the line profile h'from the line profile h is called Y _mh , and the frequency representing the maximum intensity Y _mh Is X _mh , the maximum intensity of the line profile (v-v') obtained by subtracting the line profile v'from the line profile v is Y _mv , and the frequency representing the maximum intensity Y _mv is X _mv , Y _{Based on} the values of _mh and Y _mv and (Y _mh +Y _mv )/(X _mh +X _mv ) ^1/2 calculated from Y _mh , Y _mv , X _mh and X _mv , film or optical It is a process of evaluating a laminate.

In step (e), based on the values of Y _mh and Y _mv , and the values of (Y _mh +Y _mv )/(X _mh +X _mv ) ^1/2 , the optical homogeneity of the film or optical laminate is evaluated. Can be. For example, by setting a predetermined value according to the required optical homogeneity, and comparing the result obtained with respect to the film or the optical laminate, determining whether the film is good or not and separating the film, Y _An optical film or an optical laminate having excellent optical homogeneity, in which the values of _mh and Y _mv and (Y _mh +Y _mv )/(X _mh +X _mv ) ^1/2 are equal to or less than a predetermined value, can be prepared. have. Further, while evaluating the above values, the drying conditions and the like can be adjusted to produce the optical laminate of the present invention having the above characteristics.

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

According to the said evaluation process, it becomes possible to evaluate optical homogeneity with higher precision than a conventional evaluation method. Specifically, according to the evaluation step, the optical property non-uniformity caused by the non-uniformity in both the TD direction and the MD direction or the non-uniformity of the width width that cannot be evaluated with sufficient accuracy in the conventional evaluation method can be evaluated. It is possible to evaluate the optical homogeneity with high precision regardless of the kind of non-uniformity. Moreover, it is also possible to quantify the homogeneity of a film or an optical laminated body by the said evaluation process. In addition, in this specification, the optical film or optical laminated body which is a measurement object in an evaluation process is also called "measurement film." The evaluation step in step (e) is specifically, the following steps (1) to (5):

(1) A step of obtaining a projected image by a projection method in which light from a light source is irradiated onto a measurement film and the light transmitted through the measurement film is projected onto a projection surface,

(2) A step of obtaining a background image by projecting light from a light source onto a projection surface without using a measurement film in the projection method of step (1),

(3) The projected image obtained in step (1) and the background image obtained in step (2) are numerically quantified by gray-scale, respectively, and Fourier transform the digitized image data to inverse space (film inverse space and background inverse space) Phase),

(4) A step of obtaining a blank corrected line profile by subtracting each line profile in the two directions orthogonal in the inverse space of the background image from each line profile in two directions orthogonal in the inverse space on the projected image. ,

And,

(5) Process for measuring the maximum strength (Y _mh and Y _mv ) of the blank corrected line profile obtained in step (4)

It includes at least.

In step (1), light from the light source is irradiated onto the measurement film, and light transmitted through the measurement film is projected onto a projection surface to obtain a projected image. In the step (1), for example, as shown in FIG. 1, a measurement film, a projection surface, or the like may be arranged. Specifically, the light source 1, the measurement film 2, and the projection surface 3 are arranged, and the projected image 4 projected on the projection surface 3 is photographed with the camera 6 to obtain a projected image. The light 5 output from the light source 1 passes through the measurement film 2, and the transmitted light is projected onto the projection surface 3 as a projected image 4. When the light 5 passes through the measurement film 2, if the measurement film 2 is homogeneous, the light 5 passes through the measurement film 2 homogeneously to reach the projection surface 3, but the measurement film ( 2) When this is not homogeneous, and there is surface irregularity, thickness irregularity, orientation irregularity, etc., reflection and/or refraction is generated when the light 5 passes through the measurement film 2, and is output from the light source. Compared to the state, the distorted light reaches the projection surface 3. By evaluating the thus obtained projection image 4 by the method described later, the optical homogeneity of the measurement film can be evaluated or quantified with high precision. From the viewpoint of easy to obtain a clear projected image, it is preferable to shoot in the dark room by transmitting only light from the light source through the measurement film. The type of the light source is not particularly limited, and for example, an LED light source or a halogen lamp may be used. A light source close to the point light source is preferable, and the light emitting portion is preferably 1 cm or less in diameter. Since the projected image tends to become unclear when passing through a filter or a lens, light that does not pass through the filter or lens is preferable. The projection surface is not particularly limited as long as the projected image of the measurement film is viewed, but for example, an acrylic plate, a vinyl chloride plate, a polyethylene plate, a movie screen, or the like may be used. The photographing method of the image projected on the projection surface is not particularly limited, but for example, as shown in FIG. 1, the projection surface 3, the measurement film 2, and the light source 1 are arranged in a straight line, and the projection surface 3 The camera 6 may be fixed at a position where the projected image 4 projected on the camera is photographed obliquely. The photographing mode may be appropriately set, or, for example, a setting as described in the examples may be used. In this way, a projected image is obtained.

In step (2), in the projection method of step (1), a measurement image is obtained by projecting light from a light source onto a projection surface without using a measurement film. Specifically, for example, in Fig. 1, photographing is performed with only the measurement film 2 removed, and a background image is obtained.

In the step (3), the projected image obtained in the step (1) and the background image obtained in the step (2) are respectively digitized by gray scale, and the inverse spatial image is obtained by Fourier transforming the digitized image data. The gray scale can be performed by, for example, 8-bit gray scale using image analysis software (for example, "Image-J" manufactured by the National Institute of Sanitation, USA). The projection image and the background image can be digitized by gray scale. Subsequently, the inverse spatial image (film inverse spatial image and background inverse spatial image) is obtained by Fourier transform of the digitized image data. By performing Fourier transform of the digitized image data, it is possible to obtain the period and amplitude of the lightness of the image. As a method of Fourier transform, the Fourier transform function of image analysis software (Image-J) is used, for example.

In the step (4), blank corrected lines are subtracted from each line profile in the two directions orthogonal in the inverse space of the projected image from each line profile in the two directions orthogonal in the inverse space on the background image, respectively Get a profile.

In step (5), the maximum intensity Y _max (Y _mh and Y _mv , respectively) of the blank corrected line profile obtained in step (4) is measured. The measurement methods of Y _mh and Y _mv are as described above for the measurement film, and, for example, each direction in the horizontal direction (h1 direction) and the vertical direction (v1 direction) passing through the center of the inverse space. In the case of creating a line profile, for example, it is shown as a graph showing frequency on the X axis and intensity on the Y axis, as shown in FIG. 3. Then, the maximum intensity Y _max in the horizontal (h1 direction) line profile is referred to as Y _mh1 , and X is a value obtained by subtracting the median value X _cen of the entire frequency in the blank-corrected line profile from the frequency representing the maximum intensity Y _mh1 . _{Let max} be X _mh1 . In addition, the maximum intensity Y _max in the line profile in the vertical direction (v1 direction) is referred to as Y _mv1 , and X is a value obtained by subtracting the median value X _cen of the entire frequency in the blank-corrected line profile from the frequency representing the maximum intensity Y _{mv1 Let max} be X _mv1 . The two directions are not particularly limited as long as they are orthogonal to each other, and may be two directions that do not pass through the center, and may not be horizontal and vertical directions.

By measuring the Y _mh and Y _mv , homogeneity can be evaluated in the two-dimensional direction of the measurement film. The surface non-uniformity, which is one cause of deteriorating the optical homogeneity of the measurement film, is a kind of non-uniformity that cannot be sufficiently detected in one-dimensional evaluation, such as, for example, striped non-uniformity. According to the evaluation method of the present invention, since optical homogeneity can be evaluated in the two-dimensional direction, evaluation can be performed with high precision regardless of the kind of non-uniformity of the measurement film. In addition, it is also possible to quantify the homogeneity of the measurement film by measuring Y _mh and Y _mv to obtain a value.

In addition to the maximum intensity Y _mh and Y _mv , evaluation is performed using X _mh and X _mv , which is the value obtained by subtracting the median value X _cen of the entire frequency in the blank-corrected line profile from the frequencies representing these maximum intensity, It is also possible to detect a cycle in which surface-like non-uniformity, which is one cause that affects the optical homogeneity of the measurement film, occurs.

The optical laminate of the present invention may be a film roll wound around a winding core. The material constituting the core is not particularly limited, for example, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyester resin, epoxy resin, phenol resin, melamine resin, silicon resin, polyurethane resin, polycarbonate resin , ABS resin and other synthetic resins; Metals such as aluminum; Fiber-reinforced plastics (FRP: a composite material in which fibers such as glass fibers are contained in plastics to improve strength); The shape of the winding core is also not particularly limited, but is preferably a cylindrical shape or a cylindrical shape. When the winding core has a cylindrical shape or a cylindrical shape, the outer diameter is preferably 1 to 12 inches, more preferably 3 to 10 inches, and more preferably 3 to 6 inches, from the viewpoint of strength and operability. In addition, from the viewpoint of operability, the longitudinal length of the winding core is preferably 1.0 to 2.0 times, more preferably 1.0 to 1.8 times, and more preferably 1.0 to 1.5 times the length in the width direction of the wound transparent resin film. to be.

When the optical laminated body of this invention is in the form of a film roll, in the manufacturing process of an optical laminated body, the optical laminated body which has an optical film and a functional layer, and optionally a protective film may have the form wound in roll shape to the winding core. . The optical film is not peeled off from the support, and all of the support may be wound. The optical laminate of the present invention may be an optical laminate in the form of a film roll, or a film obtained by cutting an optical laminate in the form of a film roll.

From the viewpoint of easy to increase the optical homogeneity of the optical laminate of the present invention, the length in the width direction is preferably 20 cm or more, more preferably 30 cm or more, more preferably 40 cm or more, even more preferably 50 cm or more, especially It is preferably 60 cm or more. The upper limit of the length in the width direction is not particularly limited, but may be, for example, about 200 cm or less. In addition, the optical laminate of the present invention, from the viewpoint of easy to increase the optical homogeneity, the length in the longitudinal direction is preferably 1 m or more, more preferably 10 m or more, more preferably 100 m or more, even more preferably 200 m or more , More preferably 300 m or more, and particularly preferably 400 m or more. The upper limit of the length in the longitudinal direction is not particularly limited, and may be, for example, about 5000 m or less. By laminating at least one functional layer on the optical film having the size described above, an optical laminate having the above size can be produced. From the viewpoint of easily increasing the optical homogeneity, the optical laminate having the above size is preferably produced by a roll-to-roll method, that is, preferably in the form of a film roll. From the obtained film roll, an optical laminated body can be cut out and used according to the size of the required flexible device.

When the size of the optical laminate or the optical film is large as described above, for example, a film having a predetermined size (for example, 200 mm×300 mm) is cut out to be a measurement film, and Y _mh obtained for the measurement film You may evaluate values, such as. You may measure with respect to multiple sheets, and you may evaluate using the average value of the obtained values. The preferred range of the average value is the same as the above range for Y _{mh or the} like.

<protective film>

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

The thickness of the protective film is not particularly limited, but is usually 10 to 120 μm, preferably 15 to 110 μm, and more preferably 20 to 100 μm. When two protective films are laminated on the optical laminate of the present invention, the thickness of each protective film may be the same or different.

<Flexible display device>

The present invention also provides a flexible display device comprising the optical laminate of the present invention. The optical laminate of the present invention is preferably used as a front plate in a flexible display device, and the front plate may be referred to as a window film. The flexible display device is composed of a laminate for a flexible display device and an organic EL display panel, and a laminate for a flexible display device is disposed on the viewer side with respect to the organic EL display panel to be bendable. The laminate for a flexible display device may further contain a polarizing plate (preferably a circular polarizing plate), a touch sensor, or the like, and their lamination order is arbitrary, but the window film, the polarizing plate, the order of the touch sensor from the viewer side, or It is preferable that they are laminated in the order of window film, touch sensor, and polarizing plate. When the polarizing plate is present on the viewing side than the touch sensor, it is preferable because the pattern of the touch sensor is difficult to visualize and the visibility of the display image is improved. Each member can be laminated using an adhesive, an adhesive, or the like. In addition, the flexible display device may include a light blocking pattern formed on at least one surface of any one of the window film, the polarizing plate, and the touch sensor.

<Circular polarizer>

As described above, the flexible display device of the present invention is preferably provided with a polarizing plate, particularly a circular polarizing plate. The circular polarizing plate is a functional layer having a function of transmitting only the right or left circularly polarizing component by laminating the λ/4 phase difference plate on the linearly polarizing plate. For example, it is used to convert external light into right circularly polarized light, block external light that is reflected by the organic EL panel and become left circularly polarized, and suppress the influence of reflected light by transmitting only the light-emitting component of the organic EL to make the image easier to see. . In order to achieve the circular polarization function, the absorption axis of the linearly polarizing plate and the slow axis of the λ/4 phase difference plate need to be theoretically 45 degrees, but is practically 45±10 degrees. The linearly polarizing plate and the λ/4 phase difference plate are not necessarily stacked adjacently, and the relationship between the absorption axis and the slow axis may only satisfy the above-mentioned range. It is preferable to achieve full circular polarization at all wavelengths, but in practical use, it is not necessary, so the circular polarizing plate in the present invention also includes an elliptical polarizing plate. It is also desirable to further improve the visibility in a state in which polarized sunglass is used by further stacking a lambda /4 phase difference film on the viewing side of the linear polarizing plate and making the emitted light circularly polarized.

The linearly polarizing plate is a functional layer having a function of transmitting light oscillating in the direction of the transmission axis, but blocking polarization of a vibration component perpendicular to it. The linear polarizer may be configured with a linear polarizer alone or a linear polarizer and a protective film attached to at least one surface thereof. The thickness of the linear polarizing plate may be 200 μm or less, and is preferably 0.5 to 100 μm. When the thickness of the linearly polarizing plate is within the above range, the flexibility of the linearly polarizing plate tends to be difficult to deteriorate.

The linear polarizer may be a film-type polarizer produced by dyeing and stretching a polyvinyl alcohol (hereinafter sometimes abbreviated as PVA)-based film. A dichroic dye such as iodine is adsorbed to a PVA-based film oriented by stretching, or stretched in a state adsorbed to PVA, whereby the dichroic dye is oriented to exhibit polarization performance. In the production of the above-mentioned film-type polarizer, other processes such as swelling, crosslinking with boric acid, washing with an aqueous solution, and drying may be performed. The stretching or dyeing process may be performed alone with a PVA-based film, or may be performed in a state of being laminated with another film such as polyethylene terephthalate. The thickness of the PVA-based film used is preferably 10 to 100 µm, and the stretching ratio is preferably 2 to 10 times.

Moreover, as another example of the said polarizer, the liquid crystal coating type polarizer formed by apply|coating a liquid crystal polarizing composition is mentioned. The liquid crystal polarizing composition may include a liquid crystal compound and a dichroic dye compound. It is preferable that the liquid crystal compound has a property of exhibiting a liquid crystal state, and particularly, it has a high degree of orientation such as a smectic phase, so that high polarization performance can be exhibited. Moreover, it is preferable that a liquid crystal compound has a polymerizable functional group.

The dichroic dye compound is a dye that is oriented with the liquid crystal compound and exhibits dichroism, and may have a polymerizable functional group or the dichroic dye itself may have liquid crystallinity.

Any of the compounds included in the liquid crystal polarizing composition has a polymerizable functional group. The liquid crystal polarizing composition may further include an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, and a silane coupling agent.

The said liquid crystal polarizing layer is manufactured by apply|coating a liquid crystal polarizing composition on an alignment film, and forming a liquid crystal polarizing layer. The liquid crystal polarizing layer can have a thickness thinner than that of the film polarizer, and the thickness is preferably 0.5 to 10 μm, more preferably 1 to 5 μm.

The alignment film is produced, for example, by applying an alignment film forming composition on a substrate, and imparting alignment properties by rubbing, polarization irradiation, or the like. The alignment film forming composition may include an alignment agent, and may further include a solvent, a crosslinking agent, an initiator, a dispersing agent, a leveling agent, a silane coupling agent, and the like. Examples of the alignment agent include polyvinyl alcohols, polyacrylates, polyamic acids, and polyimides. When using the alignment agent which gives orientation by polarization irradiation, it is preferable to use the alignment agent containing a cinnamate group. The weight average molecular weight of the polymer used as the alignment agent is, for example, about 10,000 to 1,000,000. The thickness of the alignment film is preferably 5 to 10,000 nm, and more preferably 10 to 500 nm from the viewpoint of sufficiently expressing the orientation regulating force.

The liquid crystal polarizing layer may be peeled off from the substrate and transferred to be laminated, or the substrate may be laminated as it is. It is also preferable that the substrate serves as a transparent substrate for the protective film, retardation plate, and window film.

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

The lambda /4 phase difference plate is a film that gives a lambda /4 phase difference in a direction orthogonal to the traveling direction of the incident light (in-plane direction of the film). The λ/4 phase difference plate may be a stretched phase difference plate produced by stretching a polymer film such as a cellulose-based film, an olefin-based film, or a polycarbonate-based film. The λ/4 retardation plate is, if necessary, retardation adjuster, plasticizer, ultraviolet absorber, infrared absorber, colorant such as pigment or dye, fluorescent brightener, dispersant, heat stabilizer, light stabilizer, antistatic agent, antioxidant, lubricant, solvent Etc. may be included.

The thickness of the stretched retardation plate is preferably 200 μm or less, and more preferably 1 to 100 μm. When the thickness of the stretched retardation plate is within the above range, the flexibility of the stretched retardation plate tends to be difficult to decrease.

Moreover, as another example of the said λ/4 phase difference plate, the liquid crystal coating type phase difference plate formed by apply|coating a liquid crystal composition is mentioned.

The liquid crystal composition contains a liquid crystal compound that exhibits liquid crystal states such as nematic, cholesteric, and smectic. The liquid crystal compound has a polymerizable functional group.

The liquid crystal composition may further include an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, and a silane coupling agent.

The liquid crystal coating-type retardation plate can be produced by coating and curing a liquid crystal composition on a base, as in the liquid crystal polarizing layer, to form a liquid crystal retardation layer. The liquid crystal coating type retardation plate can be formed to have a thinner thickness than the stretched retardation plate. The thickness of the liquid crystal polarizing layer is preferably 0.5 to 10 μm, more preferably 1 to 5 μm.

The liquid crystal coating type retardation plate may be peeled off from the substrate and transferred to be laminated, or the substrate may be laminated as it is. It is also preferable that the substrate serves as a transparent substrate for the protective film, retardation plate, and window film.

In general, the shorter the wavelength, the greater the birefringence, and the longer the longer the wavelength, the smaller the material exhibiting the birefringence. In this case, since a phase difference of λ/4 cannot be achieved in the entire visible light region, the in-plane phase difference is preferably 100 to 180 nm, more preferably 130 so as to be λ/4 in the vicinity of 560 nm with high visibility. It is designed to be ˜150 nm. An inverse dispersion λ/4 retardation plate using a material having a birefringence wavelength dispersion characteristic as opposed to normal is preferable in view of good visibility. As such a material, for example, a stretched retardation plate described in JP 2007-232873 A and the like, and a liquid crystal coated retardation plate described in JP 2010-30979 A can be used.

As another method, a technique of obtaining a broadband λ/4 phase difference plate by combining with a λ/2 phase difference plate is also known (for example, Japanese Patent Application Laid-open No. Hei 10-90521, etc.). The λ/2 phase difference plate is also produced by the same material method as the λ/4 phase difference plate. The combination of the stretched retardation plate and the liquid crystal coating retardation plate is arbitrary, but any of them can be made thinner by using the liquid crystal coating retardation plate.

In order to increase visibility in the oblique direction, a method of laminating a positive C plate is known to the original polarizing plate (for example, Japanese Laid-Open Patent Publication No. 2014-224837, etc.). The positive C plate may be a liquid crystal coating type retardation plate or a stretched retardation plate. The phase difference in the thickness direction of the phase difference plate is preferably -200 to -20 nm, more preferably -140 to -40 nm.

<Touch sensor>

It is preferable that the flexible display device of the present invention has a touch sensor as described above. The touch sensor is used as an input means. As a touch sensor, various forms, such as a resistive film system, a surface acoustic wave system, an infrared system, an electromagnetic induction system, and a capacitive system, are mentioned, Preferably, a capacitive system is mentioned.

The capacitive touch sensor is divided into an active area and an inactive area located on an outer portion of the active area. The active area is an area corresponding to an area (display area) where a screen is displayed on the display panel, and an area where a user's touch is sensed, and an inactive area is an area corresponding to an area (non-display area) where a screen is not displayed on the display device. . The touch sensor has a flexible substrate, a sensing pattern formed in an active region of the substrate, and a sensing pattern formed in an inactive region of the substrate, and each sensing line for connecting to an external driving circuit through the sensing pattern and a pad portion. It may include. As the substrate having flexible properties, a material similar to that of the transparent substrate of the window film can be used.

The sensing pattern may include a first pattern formed in the first direction and a second pattern formed in the second direction. The first pattern and the second pattern are arranged in different directions. The first pattern and the second pattern are formed on the same layer, and in order to sense a touched point, each pattern must be electrically connected. The first pattern is a form in which a plurality of unit patterns are connected via a seam, but the second pattern has a structure in which a plurality of unit patterns are separated from each other in an island form, so a separate bridge is used to electrically connect the second pattern. Electrodes are required. A well-known transparent electrode can be applied to the electrode for connection of the 2nd pattern. As a material of the transparent electrode, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), indium gallium zinc oxide (IGZO), cadmium tin oxide (CTO), PEDOT (poly(3,4-ethylenedioxythiophene)), carbon nanotubes (CNT), graphene, metal wires, and the like, and preferably ITO. These may be used alone or in combination of two or more. The metal used for the metal wire is not particularly limited, and examples thereof include silver, gold, aluminum, copper, iron, nickel, titanium, selenium, and chromium. These may be used alone or in combination of two or more. .

The bridge electrode may be formed over the insulating layer with an insulating layer over the sensing pattern, a bridge electrode may be formed on the substrate, and an insulating layer and a sensing pattern may be formed thereon. The bridge electrode may be formed of the same material as the sensing pattern, or may be formed of molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or an alloy of two or more of them.

Since the first pattern and the second pattern must be electrically insulated, an insulating layer is formed between the sensing pattern and the bridge electrode. The insulating layer may be formed only between the seam of the first pattern and the bridge electrode, or may be formed as a layer covering the entire sensing pattern. In the case of a layer covering the entire sensing pattern, the bridge electrode may connect the second pattern through a contact hole formed in the insulating layer.

The touch sensor has a difference in transmittance between a pattern area where a sensing pattern is formed and a non-pattern area where no sensing pattern is formed, specifically, a light transmittance caused by a difference in refractive index in these areas. As a means for properly compensating for the difference, an optical control layer may be further included between the substrate and the electrode. The optical control layer may include an inorganic insulating material or an organic insulating material. The optical control layer may be formed by coating a photocurable composition comprising a photocurable organic binder and a solvent on a substrate. The photocurable composition may further include inorganic particles. The refractive index of the optical control layer can be increased by the inorganic particles.

The photocurable organic binder may include a copolymer of each monomer, such as an acrylate-based monomer, a styrene-based monomer, and a carboxylic acid-based monomer, within a range that does not impair the effects of the present invention. The photocurable organic binder may be, for example, a copolymer containing each repeating unit different from each other such as an epoxy group-containing repeating unit, an acrylate repeating unit, and a carboxylic acid repeating unit.

As said inorganic particle, zirconia particle, titania particle, alumina particle, etc. are mentioned, for example.

The photocurable composition may further include additives such as a photopolymerization initiator, a polymerizable monomer, and a curing aid.

<Adhesive layer>

Each layer (window film, circular polarizing plate, touch sensor) forming the laminate for the flexible image display device and the film member (linear polarizing plate, λ/4 retardation plate, etc.) constituting each layer can be bonded by an adhesive. . Examples of the adhesive include water-based adhesives, organic solvent-based, solvent-free adhesives, solid adhesives, water-based solvent volatilization-type adhesives, moisture-curable adhesives, heat-curable adhesives, anaerobic curing type, active energy ray-curable adhesives, curing agent mixed adhesives, and hot melt adhesives, Pressure-sensitive adhesives (adhesives), re-wet adhesives, and other commonly used adhesives can be used. Preferably, a water-based solvent volatilization-type adhesive, an active energy ray-curable adhesive, or an adhesive can be used. The thickness of the adhesive layer can be appropriately adjusted according to the required adhesive force, and is preferably 0.01 to 500 µm, more preferably 0.1 to 300 µm. Although the plurality of adhesive layers exist in the laminate for the flexible image display device, the thickness and type of each may be the same or different.

As the water-based solvent-based adhesive, water-dispersible polymers such as polyvinyl alcohol-based polymers, water-soluble polymers such as starch, ethylene-vinyl acetate-based emulsions, and styrene-butadiene-based emulsions can be used as the main polymer. Can be. In addition to the above main polymer and water, a crosslinking agent, a silane compound, an ionic compound, a crosslinking catalyst, an antioxidant, a dye, a pigment, an inorganic filler, an organic solvent, etc. may be blended. In the case of bonding with the water-based solvent volatilization-type adhesive, the water-based solvent volatilization-type adhesive is injected between the layers to be adhered to bond the layers to be adhered, followed by drying to impart adhesiveness. When using the water-based solvent-based adhesive, the thickness of the adhesive layer is preferably 0.01 to 10 μm, more preferably 0.1 to 1 μm. When using the said water-soluble solvent volatilization type adhesive in multiple layers, the thickness and kind of each layer may be the same or different.

The active energy ray-curable adhesive may be formed by curing an active energy ray-curing composition comprising a reactive material that irradiates active energy rays to form an adhesive layer. The active energy ray-curable composition may contain at least one polymerizable product of a radically polymerizable compound and a cationic polymerizable compound similar to those contained in the hard coating composition. As the radically polymerizable compound, the same compound as the radically polymerizable compound in the hard coating composition can be used.

As the cationic polymerizable compound, the same compound as the cationic polymerizable compound in the hard coating composition can be used.

As the cationically polymerizable compound used in the active energy ray curing composition, an epoxy compound is particularly preferred. It is also preferable to include a monofunctional compound as a reactive diluent in order to lower the viscosity as an adhesive composition.

The active energy ray composition may contain a monofunctional compound in order to lower the viscosity. As the monofunctional compound, an acrylate-based monomer having one (meth)acryloyl group in one molecule, or a compound having one epoxy group or oxetanyl group in one molecule, for example, glycidyl (meth) And acrylates.

The active energy ray composition may further include a polymerization initiator. Examples of the polymerization initiator include a radical polymerization initiator, a cationic polymerization initiator, a radical and a cationic polymerization initiator, and these are suitably selected and used. These polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate radicals or cations to advance radical polymerization and cation polymerization. Among the substrates of the hard coating composition, an initiator capable of initiating at least either radical polymerization or cationic polymerization by active energy ray irradiation can be used.

The active energy ray curing composition may further include an ion trapping agent, an antioxidant, a chain transfer agent, an adhesion imparting agent, a thermoplastic resin, a filler, a flow viscosity modifier, a plasticizer, an antifoaming agent, an additive, and a solvent. In the case of bonding the two to-be-adhesive layers by the active energy ray-curable adhesive, the active energy ray-curable composition is applied to one or both of the to-be-adhesive layers, and then bonded to the active energy ray to either or both of the to-be-adhesive layers. It can be adhered by irradiating and curing. When the active energy ray-curable adhesive is used, the thickness of the adhesive layer is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm. When the active energy ray-curable adhesive is used to form a plurality of adhesive layers, the thickness or type of each layer may be the same or different.

As the above-mentioned pressure-sensitive adhesive, any one classified as an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, or a silicone-based pressure-sensitive adhesive may be used depending on the main polymer. In addition to the main polymer, a crosslinking agent, a silane compound, an ionic compound, a crosslinking catalyst, an antioxidant, a tackifier, a plasticizer, a dye, a pigment, an inorganic filler, etc. may be added to the adhesive. The adhesive layer is formed by dissolving and dispersing each component constituting the pressure-sensitive adhesive in a solvent to obtain a pressure-sensitive adhesive composition, and then applying the pressure-sensitive adhesive composition to a substrate and drying it. The adhesive layer may be formed directly, or may be transferred to one formed on a separate substrate. It is also preferable to use a release film to cover the adhesive surface before adhesion. When the active energy ray-curable adhesive is used, the thickness of the adhesive layer is preferably 0.1 to 500 μm, more preferably 1 to 300 μm. When using multiple layers of the said adhesive, the thickness and kind of each layer may be the same or different.

<Shading pattern>

The light-shielding pattern can be applied as at least a part of the bezel or housing of the flexible image display device. The visibility of the image is improved by making the wiring disposed in the periphery of the flexible image display device hidden and difficult to see by the light-shielding pattern. The light shielding pattern may be in the form of a single layer or multiple layers. The color of the light-shielding pattern is not particularly limited, and various colors such as black, white, and metal may be used. The light-shielding pattern may be formed of a pigment for realizing color, and a polymer such as acrylic resin, ester resin, epoxy resin, polyurethane, and silicone. It may be used alone or as a mixture of two or more. The light-shielding pattern can be formed by various methods such as printing, lithography, and inkjet. The thickness of the light shielding pattern is preferably 1 to 100 μm, more preferably 2 to 50 μm. In addition, it is also preferable to give a shape such as a slope in the thickness direction of the light-shielding pattern.

[Example]

Hereinafter, the present invention will be described in more detail by examples, but the present invention is not limited to the following examples. In the examples, "%" and "parts" mean mass% and parts by mass unless otherwise specified. First, a method of measuring a property value will be described.

<weight average molecular weight>

Gel permeation chromatography (GPC) measurements

(1) Pretreatment method

The sample was dissolved in γ-butyrolactone (GBL) to make a 20% by mass solution, diluted 100-fold with DMF eluent, and filtered with a 0.45 μm membrane filter as a measurement solution.

(2) Measurement conditions

Column: TSKgel SuperAWM-H×2+SuperAW2500×1 (6.0 mm I.D.×150 mm×3)

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

Flow rate: 0.6 mL/min

Detector: RI detector

Column temperature: 40°C

Injection volume: 20 μL

Molecular weight standard: standard polystyrene

<Imidization rate>

The imidation ratio was determined as follows by ¹ H-NMR measurement.

(1) Pretreatment method

The sample was dissolved in deuterated dimethyl sulfoxide (DMSO-d ₆ ) to prepare a 2% by mass solution as a measurement solution.

(2) Measurement conditions

Measuring device: 400 MHz NMR device JNM-ECZ400S/L1 made by JEOL

Standard Substance: DMSO-d ₆ (2.5ppm)

Sample temperature: room temperature

Accumulation count: 256 times

Relax time: 5 seconds

(3) Analysis method of imidation rate

(3-1) The imidation ratio of polyimide resin A

Of the benzene protons observed in the ¹ H-NMR spectrum obtained for the measurement solution containing the polyimide resin A, the integral value of benzene proton A derived from a structure that does not change before and after imidization was referred to as Int _A.

In addition, the integral value of the amide proton derived from the amic acid structure remaining in the polyimide resin was referred to as Int _B. The imidation ratio of polyimide resin A was calculated|required from these integral values based on the following formula. In the following formula, α is the number ratio of benzene proton A to 1 amide proton in the case of polyamic acid (0% imidation).

Imidation rate (%)=100×(1-α×Int _B /Int _A )

(3-2) The imidation ratio of polyamideimide resin A

Among the benzene protons observed in the ¹ H-NMR spectrum obtained for the measurement solution containing polyamideimide resin A, it originates from a structure that does not change before and after imidation, and from an amic acid structure that remains in the polyamideimide resin. The integral value of benzene proton C, which is not affected by the structure, is called Int _C.

In addition, the integral value of benzene proton D in the observed benzene proton, which is derived from a structure that does not change before and after imidation, and is influenced by a structure derived from an amic acid structure remaining in the polyamideimide resin A, is referred to as Int _D. From these integral values, β values were determined based on the following equation.

β=Int _D /Int _C

Subsequently, in order to obtain a correlation equation in which β is converted into an imidation rate, for a plurality of polyamideimide resins having different imidation rates, β values are obtained in the same manner as described above, and the imidation rate is determined using the HSQC spectrum. The following correlation equation was obtained from these results.

Imidation rate (%)=k×β+100

In the above correlation, k is a constant.

Subsequently, β obtained with respect to the polyamideimide resin A was substituted into the correlation equation to obtain an imidation ratio (%) of the polyamideimide resin A.

<Average primary particle diameter>

The specific surface area of the powder obtained by drying the silica sol at 300°C was measured using a monosurface MS-16 manufactured by Yuasa Ionics, and the measured specific surface area S (m ² /g) was used. , D(nm) = 2720/S, the average primary particle size was calculated.

<Viscosity of the varnish>

In accordance with JIS K 8803:2011, it was measured using Brookfield's E-type viscometer DV-II+Pro. The measurement temperature was 25°C.

<The thickness of the film>

Using Mitsutoyo Corporation ID-C112XBS, the film thickness of 10 or more points was measured, and the average value was computed.

<Thickness of functional layer>

The thickness of the functional layer was measured using an F20 tabletop film thickness system manufactured by Filmetrics.

<The total light transmittance of the film, Haze>

The said optical characteristic value was measured using the spectrophotometer CM-3700A manufactured by Konica Minolta Corporation.

<The yellowness of the film>

The yellowness (Yellow Index: YI value) of the optical film was measured using a spectrophotometer CM-3700A manufactured by Konica Minolta Corporation. Specifically, after background measurement in the absence of a sample, the optical film is set in a sample holder, transmittance measurement for light of 300 to 800 nm is obtained, and tristimulus values (X, Y, Z) are obtained, The YI value was calculated based on the following formula.

YI=100×(1.2769X-1.0592Z)/Y

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

<Measurement of surface resistivity>

The surface resistivity (Ω/sq) of the optical laminate was measured in accordance with JIS K 6911 using a resistivity meter (Mitsubishi Chemical Analtech Co., Ltd., high lester UP MCP-HT450 type). The sample was cut to a size of 50 mm×50 mm, and the obtained sample was left at 23° C. and 50% RH for 24 hours. Thereafter, the surface resistivity of the functional layer side of the optical laminate was measured. In addition, the upper limit of measurement of the device is 1.0E+14 Ω/sq, and when it has a surface resistivity higher than that, it is indicated as OVER on the device.

<Method for evaluating optical homogeneity of optical film or optical laminate>

1. Shooting projected images and background images

2, the light source 1, the measurement film 2, the projection surface 3, and the camera 6 were arrange|positioned in the dark room, and the projection image 4 was imaged. The distance between the light source 1 and the measurement film 2 is 250 cm, the distance between the measurement film 2 and the projection surface 3 is 30 cm, the measurement film 2 and the projection surface 3 are arranged in parallel, and the camera ( 6) is installed just below the normal from the light source 1 to the screen, the distance between the camera 6 and the projection surface 3 (screen) is 30 cm, and the camera angle 7 (the camera is perpendicular to the screen. The angle to incline upward from the state facing toward it was 25 degrees. Note that the background image was photographed in the same manner as the projection image photographed except that the measurement film 2 was removed in FIG. 2. Details of the measurement conditions and shooting conditions are shown below.

Light source: LED light source ("LA-HDF15T" manufactured by Hayashi Watch Industry Co., Ltd.)

Measurement film: The optical film or optical laminate manufactured in the following examples and comparative examples was cut out to 200 mm×300 mm, and used as a measurement sample.

Projection surface: White commercial movie ornamental screen (Theater House Co., Ltd., ``BTP600FHD-SH1000'')

Camera: Nikon Corporation ``COOLPIX (registered trademark) P600''

Detailed camera settings: Manual shooting mode

Image size 2M

Focus Manual Focus (Distance 0.3m)

Shutter speed 1/2 second

Aperture value (F value) 4.2

Flash OFF

2. Fourier Transform

In this embodiment, since the camera is installed at the position of the camera angle, inclination is generated in the projected image. For this reason, in order to first correct the inclination of the projected image, the inclination correction condition was determined. In addition, correction is unnecessary when there is no distortion of the projected image.

(Determination of slope correction conditions)

A 10 cm×10 cm square was drawn on a transparent film, and a reference projection image was taken under the condition 1 above. The obtained reference projection image was read by Adobe Systems' Photoshop (registered trademark) CS4, and the camera and screen were corrected to correspond to 90 degrees using a lens correction distortion correction function, and stored in a TIFF format. The conditions at this time were used as the slope correction conditions. The length of each vertical and horizontal pixel was calculated from the reference projected image after tilt correction (vertical: 816 pixel = 10 cm, horizontal: 906 pixel = 10 cm).

(Fourier transform)

The projected image obtained as described above for the measurement film was corrected under the inclination correction conditions determined as described above, and the corrected image was stored in the TIFF format. The obtained projection image after tilt correction is image analysis software "Image-J, ver. 1.48” and converted to an 8-bit gray scale. In addition, the length of each vertical and horizontal pixel obtained from the reference projected image after tilt correction was used as a set scale. A rectangular range having a size of 10.2 cm×11.2 cm (vertical×horizontal) among gray scale images was selected, and an image of the selected range was Fourier transformed using Imag stirring eJ to obtain an inverse spatial image. For the inverse spatial image after Fourier transform, the correct value ( ¹ :=11.3cm ^{-1 in the} horizontal direction, ^{1 -1} in the vertical direction = 12.55cm ^-1 ) was entered in the Set Scale.

3. Measurement of maximum intensity (Y _mh1 and Y _mv1 ) of blank corrected line profile

In the inverse space obtained as described above, a line profile was created for each direction in the horizontal direction (h1 direction) and the vertical direction (v1 direction) passing through the center of the inverse space. The line width was 10 pixels. The obtained line profile was preserved in text format. Subsequently, the data in the text format is read by Microsoft Corporation Excel (ver.14.0), and the line profile is normalized as follows, for each direction in the horizontal direction (h1 direction) and the vertical direction (v1 direction), The line profile of Y" is obtained, and the maximum intensity Y _max in each line profile is referred to as Y _mh1 and Y _mv1 , and the median value X of the total frequency in the blank-corrected line profile from the frequencies representing maximum intensity Y _mh1 and Y _mv1 X _max , which is the value obtained by subtracting _cen , is referred to as X _mh1 and X _mv1 , respectively.The standardization method will be described using the line profile in the horizontal direction (h1 direction) obtained in Example 1 as an example.

(Standardization method)

The frequency at which the value of Y becomes the maximum is taken as the center of X (X _cen ), and the value of Y at that time is defined as Y _cen . Next, the center of X _cen and the average value of Y is obtained for a region of 100 pixels in total for each of 50 pixels at both ends, and the average value is referred to as a base line (Y _base ). Then, _Y'is obtained by correcting the data Y according to the following equation so that Y _cen =100 and Y _base =0.

By performing the above correction on the line profile (data Y) obtained in Example 1 shown in Fig. 4, a line profile A (data Y') as shown in Fig. 5 is obtained.

Subsequently, the same operation was performed for the background image obtained in 1 to obtain a line profile of the background image. Specifically, a line profile B as shown in Fig. 6 was obtained.

Subsequently, from the profile A described above, the background profile B was subtracted by Excel to perform blank correction. In Example 1, the data of the line profile B as shown in Fig. 6 was subtracted from the data Y'of the line profile A shown in Fig. 5 to obtain a blank corrected line profile A-B as shown in Fig. 7.

The line profile thus obtained was smoothed to obtain a profile of Y", which was used to measure the maximum intensity of the line profile (Y _mh1 and Y _mv1 ). The smoothing of the graph was 21 data according to the following equation. The average value of y _i was calculated and performed.

(Sensory evaluation of visibility)

In an indoor environment dimmed at 50 to 100 lux, the produced film was visually inspected at an angle of 80 degrees of elevation, and visibility was evaluated by distortion of the reflected background. Table 2 shows the results. In addition, the evaluation criteria of visibility are as follows.

◎: No distortion is observed in the background.

○: Distortion in the background is not roughly confirmed.

(Triangle|delta): Although the distortion which is very close to the background is confirmed, the level without a problem.

×: Clear distortion is observed in the background.

<Amount of residual solvent>

Using TG-DTA (EXSTAR6000 TG/DTA6300 manufactured by SII Co., Ltd.), the transparent resin films obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were heated from 30°C to 120°C and held at 120°C for 5 minutes. Then, it heated up to 400 degreeC at the heating rate of 5 degreeC/min. The ratio of the mass reduction of the film from 120°C to 250°C with respect to the mass of the film at 120°C was calculated as the content of the solvent (referred to as the residual solvent amount).

Abbreviations used in the following Production Examples and Examples are as follows.

TFMB: 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl

6FDA: 4,4'-(hexafluoroisopropylidene) diphthalic anhydride

TPC: terephthaloyl chloride

OBBC: 4,4'-oxybis (benzoyl chloride)

DMAc: N,N-dimethylacetamide

GBL: γ-butyrolactone

PET: polyethylene terephthalate

<Production Example>

Production Example 1: Preparation of polyamideimide resin 1

Under a nitrogen gas atmosphere, a reaction vessel equipped with a stirring blade in a separable flask and an oil bath were prepared. To the reaction vessel installed in the oil bath, 45 parts of TFMB and 768.55 parts of DMAc were charged. TFMB was dissolved in DMAc while the contents in the reaction vessel were stirred at room temperature. Subsequently, 19.01 parts of 6FDA was further added into the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 3 hours. Thereafter, 4.21 parts of OBBC and then 17.30 parts of TPC were added to the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 1 hour. Subsequently, 4.63 parts of 4-methylpyridine and 13.04 parts of acetic anhydride were further added into the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 30 minutes. After stirring, the temperature inside the vessel was raised to 70°C using an oil bath, maintained at 70°C and stirred for an additional 3 hours to obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, poured into a large amount of methanol in a thread shape to precipitate a precipitate. The precipitated precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Subsequently, the precipitate was dried under reduced pressure at 100°C to obtain polyamideimide resin 1. The weight average molecular weight of the obtained polyamide-imide resin 1 was 400,000, and the imidation rate was 99.0%.

Production Example 2: Preparation of polyimide resin 1

A reactor equipped with a silica gel tube, a stirring device, and a thermometer, and an oil bath were prepared in the separable flask. 75.52 parts of 6FDA and 54.44 parts of TFMB were put into this flask. While stirring this at 400 rpm, 519.84 parts of DMAc was added, and stirring was continued until the contents of the flask became a uniform solution. Subsequently, using an oil bath, stirring was continued for an additional 20 hours while adjusting the temperature inside the vessel to be in the range of 20 to 30°C, and reacted to produce polyamic acid. After 30 minutes, the stirring speed was changed to 100 rpm. After stirring for 20 hours, the reaction system temperature was returned to room temperature, and 649.8 parts of DMAc was added to adjust the polymer concentration to 10% by mass. Further, 32.27 parts of pyridine and 41.65 parts of acetic anhydride were added, followed by stirring at room temperature for 10 hours to imidize. The polyimide varnish was taken out from the reaction vessel. The obtained polyimide varnish was added dropwise to methanol to reprecipitate, and the obtained powder was heated and dried to remove the solvent to obtain polyimide resin 1 as a solid content. When GPC measurement was performed on the obtained polyimide resin 1, the weight average molecular weight was 320,000. In addition, the imidation ratio of the polyimide was 98.6%.

Preparation Example 3: Preparation of silica sol 1

Amorphous silica sol having an average primary particle diameter (average primary particle diameter measured by the BET method) of 12 nm prepared by the sol-gel method was used as a raw material, and GBL-substituted silica sol was prepared by solvent substitution. The obtained sol was filtered through a membrane filter of 10 µm in length to obtain GBL-substituted silica sol 1. In the obtained GBL-substituted silica sol 1, the content of silica particles was 30 to 32% by mass.

Production Example 4: Preparation of varnish (1)

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

Production Example 5: Preparation of varnish (2)

The polyimide resin 1 obtained in Production Example 2 and 2.0 phr of the ultraviolet absorber "Sumisorb 250" (molecular weight 389, manufactured by Sumika Chemtex Co., Ltd.) with respect to the polyimide resin were mixed with GBL:DMAc=1:9. The varnish (2) was obtained by dissolving in a solvent at a concentration of 16.5% by mass. The solid content of the varnish (2) was 16.5%, and the viscosity at 25°C was 36,800 cps.

Preparation Example 6: Photocurable resin composition 1

Trimethylolpropane triacrylate (Shin-Nakamura Chemical Co., Ltd., A-TMPT) 28.4 parts by weight, pentaerythritol tetraacrylate (Shin-Nakamura Chemical Co., Ltd., A-TMMT) 28.4 parts by weight, as a photopolymerization initiator, 1 -Hydroxycyclohexyl phenyl ketone (BASF Corporation, Irgacure (registered trademark) 184) 1.8 parts by weight, lithium bis (fluorosulfonyl) imide (Tokyo Chemical Industry Co., Ltd., LiFSI) 2.4 parts by weight, 0.1 parts by mass of a leveling agent (manufactured by BIC Chemical Japan Co., Ltd., BYK (registered trademark)-307), and 39 parts by mass of propylene glycol 1-monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) were stirred and mixed, and photocurable resin Composition 1 was obtained.

Production Example 7: Photocurable resin composition 2

A compound similar to Production Example 6 was stirred and mixed except that lithium bis(fluorosulfonyl)imide was not mixed to obtain a photocurable resin composition 2.

Example 1

The varnish (1) was applied onto a PET film (Toyobo Co., Ltd. "Cosmoshine (registered trademark) A4100", thickness 188 µm, thickness distribution ±2 µm), flexible molded to form a varnish coating film. At this time, the ship speed was 0.8 m/min. The coating film of the varnish was heated at 80° C. for 10 minutes, then heated at 100° C. for 10 minutes, then heated at 90° C. for 10 minutes, and finally dried under a drying condition of heating at 80° C. for 10 minutes to obtain a dry coating film. Formed. Then, the coating film was peeled off from the PET film to obtain a raw film 1 in the form of a film roll having a thickness of 58 µm, a width of 700 mm, and a length of 500 m. The amount of residual solvent in the raw material film 1 was 9.7 mass%. Subsequently, the polyamideimide film 1 with a thickness of 50 µm was obtained by heating the raw material film 1 at 200° C. for 25 minutes and a draw ratio of 0.98 times with a film transverse stretching device (tenter). The amount of the residual solvent in the polyamideimide film 1 was 0.7% by mass.

On one side of the obtained polyamideimide film 1, the photocurable resin composition 1 was coated with a bar coater so that the thickness after drying became 10 µm in a roll-to-roll manner. Thereafter, drying was performed in an oven at 80° C. for 3 minutes, followed by curing by irradiating with ultraviolet light at an energy of 500 mJ/cm ² of a high pressure mercury lamp to obtain an optical laminate 1 in the form of a 400 m long film roll. The thickness of the functional layer in the optical laminate 1 was 10 µm.

Example 2

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

Example 3

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

An optical layered product 3 in the form of a film roll having a length of 500 m was obtained in the same manner as in Example 2 except that polyimide film 1 was used instead of polyamideimide film 1. The thickness of the functional layer in the optical laminate 3 was 9 µm.

Comparative Example 1

Using varnish (1), the drying conditions were heated to 10 minutes at 70° C., followed by heating at 80° C. for 10 minutes, followed by heating at 100° C. for 10 minutes, and finally changed to conditions for heating at 100° C. for 10 minutes. A raw material film 3 in the form of a film roll having a thickness of 58 µm, a width of 700 mm, and a length of 400 m was obtained in the same manner as in Example 1 except for the above. The amount of residual solvent in the raw film 3 was 10.1% by mass. Subsequently, a polyamideimide film 2 having a thickness of 50 µm was obtained in the same manner as in Example 1 except that the raw film 3 was used instead of the raw film 1. The amount of the residual solvent in the polyamideimide film 2 was 0.8% by mass.

An optical laminate 4 in the form of a film roll with a length of 290 m was obtained in the same manner as in Example 2, except that polyamideimide film 2 was used instead of polyamideimide film 1. The thickness of the functional layer in the optical laminate 4 was 10 µm.

Comparative Example 2

Using the varnish (2), the drying conditions were changed to conditions of heating at 100°C for 7.5 minutes, heating at 120°C for 7.5 minutes, then heating at 60°C for 7.5 minutes, and finally heating at 60°C for 7.5 minutes. A raw material film 4 in the form of a film roll having a thickness of 89 µm, a width of 700 mm, and a length of 300 m was obtained in the same manner as in Example 1 except for the above. The amount of residual solvent in the raw film 4 was 9.9 mass%. Subsequently, a polyimide film 2 having a thickness of 77 μm was obtained in the same manner as in Example 1 except that the raw film 4 was used instead of the raw film 1. The amount of residual solvent in the polyimide film 2 was 1.0 mass%.

An optical laminate 5 in the form of a film roll having a length of 190 m was obtained in the same manner as in Example 2, except that polyimide film 2 was used instead of polyamideimide film 1. The thickness of the functional layer in the optical laminate 5 was 11 µm.

Table 1 and Table 2 show the results of measuring various physical property values according to the above measuring method for the optical laminates obtained in Examples and Comparative Examples. In addition, Haze of the films of Examples and Comparative Examples was 0.2. In addition, for each value for evaluating the optical homogeneity in Table 2, the value in which a measurement sample is described as a film is a value measured for a polyamideimide film or a polyimide film before laminating a functional layer, and a measurement sample The value described as a laminate is a value measured for the optical laminate after laminating the functional layer. The evaluation of visibility was a result of evaluating the optical laminate.

In the optical laminates of Examples 1 to 3, or the optical films included in the optical laminates, Y _mh and Y _mv are 40 or less, A/B is less than 30, and evaluation of visibility is all good ◎ or ○ did. On the other hand, in the optical films included in the optical laminates of Comparative Examples 1 and 2, Y _mh exceeded 40, A/B was 30 or more, and evaluation results of visibility were Δ and ×, respectively. In addition, for the optical laminates of Comparative Examples 1 and 2, the results such as Y _mh when the optical laminate was used as a measurement film are not described, but as in the results obtained using the optical film as a measurement film, Y _mh and the like, and It is considered that A/B is not within a range specified for the optical laminate of the present invention. In addition, it was possible to impart an antistatic function to the functional layer in the optical laminate of Example 1 in addition to the hard coating function. Similarly, the functional layers of Examples 1 to 3 were layers in addition to the hard coating function, to which new functions such as antistatic function, anti-glare function, low-reflection function, anti-reflection function and anti-fouling function were provided.

1 light source
2 measuring film
3 Projection plane
4 Projected image
5 light
6 Camera
7 Camera angle

Claims (12)

As an optical laminate having an optical film comprising a polyimide-based resin and/or a polyamide-based resin, and a functional layer laminated on at least one side of the optical film,
The line profiles in the directions h and v that are orthogonal to each other on the film inverse space obtained by Fourier transforming the projected image obtained by the projection method using the optical film are referred to as the line profile h and the line profile v, respectively. In the above, the line profiles in directions h'and v which are orthogonal to each other on the background inverse space obtained by Fourier transforming the background image obtained without using the optical film are referred to as line profiles h'and line profiles v', respectively. The maximum intensity of the line profile (h-h') obtained by subtracting the line profile h'from the line profile h is called Y _mh , and the frequency representing the maximum intensity Y _mh is called X _mh , and the line profile v from the line profile v. Speaking of 'the line profile (v-v obtained by subtracting ") to a maximum intensity, and that Y _mv, the frequency showing the maximum intensity Y _mv X _mv of, Y _mh and Y _mv are all less than 40, Y _mh, Y _mv , X _mh and X _mv are the following relationships:

To satisfy the optical laminate. As an optical laminate having an optical film comprising a polyimide-based resin and/or a polyamide-based resin, and a functional layer laminated on at least one side of the optical film,
The line profiles in the directions h and v that are orthogonal to each other on the film inverse space obtained by Fourier transforming the projected image obtained by the projection method using the optical laminate are referred to as line profiles h and line profiles v, respectively. In the projection method, the line profiles in the directions h'and v are orthogonal to each other in the background inverse space obtained by Fourier transforming the background image obtained without using the optical laminate, respectively, the line profile h'and the line profile v The maximum intensity of the line profile (h-h') obtained by subtracting the line profile h from line profile h is called Y _mh , and the frequency representing the maximum intensity Y _mh is called X _mh , and the line from line profile v If the maximum intensity of the line profile (v-v') obtained by subtracting the profile _v'is Y _mv , and the frequency representing the maximum intensity Y _mv is X _mv , Y _mh and Y _mv are both 40 or less, and Y _mh , Y _mv , X _mh and X _mv are the following relationships:

To satisfy the optical laminate. The method of claim 1 or 2,
At least one of the functional layers is a layer having at least one function selected from the group consisting of a hard coating function, an antistatic function, an anti-glare function, a low reflection function, an antireflection function and an antifouling function. The method of claim 1 or 2,
The optical laminated body whose pencil hardness of at least one side of the optical laminated body is H or more. The method of claim 1 or 2,
The optical layered product whose surface resistivity of at least one surface of the optical layered product is 1.0×10 ¹³ Ω/sq or less. The method of claim 1 or 2,
The optical layered product has a yellowness of 3.0 or less. The method of claim 1 or 2,
An optical laminate having a length in the width direction of 20 cm or more and a length in the length direction of 1 m or more. The method of claim 1 or 2,
An optical laminate, which is a film for a front panel of a flexible display device. A flexible display device comprising the optical laminate according to claim 1 or 2. The method of claim 9,
A flexible display device further comprising a touch sensor. The method of claim 9,
A flexible display device further comprising a polarizing plate. A method for manufacturing the optical laminate according to claim 1 or 2,
(a) a step of applying a varnish containing at least a polyimide-based resin and/or a polyamide-based resin and a solvent on a support and drying it to form a coating film,
(b) peeling the coating film from the support,
(c) heating the peeled coating film to obtain a film, and
(d) a step of laminating a functional layer on at least one side of the film to obtain an optical laminate
The manufacturing method containing at least.

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