WO2018230495A1

WO2018230495A1 - Layered body, surface material for displays, touch panel member, liquid crystal display device, and organic electroluminescence display device

Info

Publication number: WO2018230495A1
Application number: PCT/JP2018/022201
Authority: WO
Inventors: 勝哉坂寄; 太田　貴之; 滉大岡田; 奈保美金澤; 小林　義弘; 綾勝又; 綾子古瀬; 前田　高徳; 敬輔脇田; 誠溝尻; 征一磯嶋
Original assignee: 大日本印刷株式会社
Priority date: 2017-06-16
Filing date: 2018-06-11
Publication date: 2018-12-20
Also published as: JPWO2018230495A1; JP7107311B2; TW201906733A; TWI757512B

Abstract

Provided is a layered body comprising a functional layer disposed on at least one surface of a polyimide film via a compatible layer, the functional layer including at least one polymer of a radically polymerizable compound and cationically polymerizable compound. The compatible layer includes at least one component of the constituting components of polyimide film and at least one component of the constituting components of the functional layer. The polyimide film includes a polyimide having a structure represented by general formula (1). (In general formula (1), all references are as defined in the specification.)

Description

Laminated body, surface material for display, touch panel member, liquid crystal display device, and organic electroluminescence display device

Embodiments of the present disclosure relate to a laminate, a display surface material, a touch panel member, a liquid crystal display device, and an organic electroluminescence display device.

Although thin plate glass is excellent in hardness, heat resistance, etc., it is difficult to bend, it is easy to break when dropped, there is a problem in workability, and it is heavy compared to plastic products. Therefore, in recent years, resin products such as resin base materials and resin films are being replaced with glass products from the viewpoint of processability and weight reduction, and research on resin products that are glass substitute products has been conducted.

For example, with the rapid progress of electronics such as liquid crystal and organic EL displays and touch panels, it has become necessary to make devices thinner and lighter and more flexible. Conventionally, these devices have various electronic elements such as thin transistors and transparent electrodes formed on a thin glass plate. By changing this thin glass plate to a resin film, the impact resistance of the panel itself is enhanced. , Flexible, thin and light.

In the patent document 1, the present applicant is used as a surface material of a touch panel for the purpose of having excellent hardness, transparency, and durable folding performance, and includes a base film and at least one cured resin layer. In the laminate for use, an elution layer is formed in the vicinity of the resin cured layer side interface of the base film, and the base film eluted from the elution layer is formed in the resin cured layer. A material component is contained, and the base material film is a polyimide film or an aramid film, and discloses a laminate for a touch panel.

On the other hand, in a polyimide molded body (Patent Document 2) used for a liquid crystal alignment film or the like, diaminosiloxane is used as a diamine component that is a raw material for the polyimide resin in order to improve the adhesion to an inorganic substrate. Things have been done.

JP 2017-33035 A JP 63-170420 A

Mobile devices that can fold screens are often carried in a folded state, so the flexible display mounted on a mobile device will be restored to its original state when it is flattened even if it is folded for a long time. Therefore, the base material and the surface material for flexible displays are also required to have resilience after being bent for a long time (hereinafter, sometimes referred to as static bending resistance).
However, the laminate described in Patent Document 1 shows a good result in a test in which a flat state and a bent state are repeated at a constant period, but it is difficult to return to a flat state after being bent for a long time. There is a need to improve static bending resistance. Moreover, the laminated body described in patent document 1 is also calculated | required for the further improvement of the adhesiveness of a polyimide film and a resin cured layer. In addition, there is a problem that visibility is reduced due to interference fringes caused by a difference in refractive index between the polyimide film and the cured resin layer.

The present disclosure has been made in view of the above problems, and is a laminate in which bending resistance and adhesion between a functional layer and a polyimide film are improved and interference fringes are suppressed, and the laminate. It aims at providing the surface material for a display.

One embodiment of the present disclosure has a functional layer containing at least one polymer of a radical polymerizable compound and a cationic polymerizable compound via a compatible layer on at least one surface of a polyimide film,
The compatible layer contains at least one component of the constituent components of the polyimide film and at least one component of the constituent components of the functional layer,
Provided is a laminate in which the polyimide film contains a polyimide having a structure represented by the following general formula (1).

(In the general formula (1), R ¹ represents a tetravalent group which is a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, R ² represents a divalent group which is a diamine residue, 10 mol% or more and 90 mol% or less of the total amount of R ² is a diamine residue having a silicon atom in the main chain, and 10 mol% or more and 90 mol% or less does not have a silicon atom, and is an aromatic ring or a fatty acid. (A diamine residue having a group ring. N represents the number of repeating units.)

In one embodiment of the present disclosure, in the polyimide having the structure represented by the general formula (1), a diamine residue having a silicon atom in the main chain in R ² in the general formula (1) is mainly A laminate is provided which is a diamine residue having one or two silicon atoms in the chain.

In one embodiment of the present disclosure, the thickness of the compatible layer dyed in the cross section in the thickness direction of the laminate dyed with at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate Provides a laminate having a thickness of 5 nm or more.

One embodiment of the present disclosure provides a laminate in which an internal angle measured by the test is 120 ° or more when a static bending test is performed according to the following static bending test method.
[Static bending test method]
The laminate test piece cut out to 15 mm × 40 mm is bent at a half of the long side, and both ends of the long side of the test piece sandwich a metal piece (100 mm × 30 mm × 6 mm) having a thickness of 6 mm from the upper and lower surfaces. Placed between glass plates (100 mm x 100 mm x 0.7 mm) from above and below with the tape fixed so that the overlap between the top and bottom surfaces of the test piece and the metal piece is 10 mm each. The test piece is fixed in a bent state with an inner diameter of 6 mm. At that time, a dummy test piece is sandwiched between the metal piece and the glass plate where there is no test piece, and is fixed with tape so that the glass plate is parallel. The test piece thus fixed in a bent state is left to stand for 24 hours in an environment of 60 ° C. and 90% relative humidity (RH), and then the glass plate and fixing tape are removed, and the test piece is attached to the test piece. Release this force. Thereafter, one end of the test piece is fixed, and the internal angle of the test piece 30 minutes after the force applied to the test piece is released is measured.

In one embodiment of the present disclosure, the total light transmittance measured according to JIS K7361-1 is 85% or more,
Provided is a laminate having a yellowness calculated in accordance with JIS K7373-2006 of 30 or less.
In one embodiment of the present disclosure, among them, the value obtained by dividing the yellowness of the laminate calculated in accordance with JIS K7373-2006 by the film thickness (μm) of the laminate is 0.04 or less. And it is preferable from the point which the yellowish coloring of a laminated body is suppressed and a light transmittance improves.

In one embodiment of the present disclosure, the polyimide having the structure represented by the general formula (1) includes an aromatic ring, and (i) a fluorine atom, (ii) an aliphatic ring, and (iii) an aromatic Provided is a laminate including at least one selected from the group consisting of a structure in which group rings are connected by a sulfonyl group or an alkylene group which may be substituted with fluorine.

In one embodiment of the present disclosure, in the polyimide having the structure represented by the general formula (1), R ¹ in the general formula (1) is a cyclohexanetetracarboxylic dianhydride residue, cyclopentanetetracarboxylic Acid dianhydride residue, dicyclohexane-3,4,3 ′, 4′-tetracarboxylic dianhydride residue, cyclobutanetetracarboxylic dianhydride residue, pyromellitic dianhydride residue, 3, 3 ′, 4,4′-biphenyltetracarboxylic dianhydride residue, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride residue, 4,4 ′-(hexafluoroisopropylidene) diphthalate Acid anhydride residue, 3,4 '-(hexafluoroisopropylidene) diphthalic anhydride residue, 3,3'-(hexafluoroisopropylidene) diphthalic anhydride residue, 4,4'-oxydiphthalic acid Anhydride residues and, at least one tetravalent group selected from the group consisting of 3,4'-oxydiphthalic anhydride residue, to provide a laminated body.

In one embodiment of the present disclosure, in the polyimide having the structure represented by the general formula (1), the diamine residue having the aromatic ring or the aliphatic ring in R ² in the general formula (1) is 1,4-cyclohexanediamine residue, trans-1,4-bismethylenecyclohexanediamine residue, 4,4′-diaminodiphenylsulfone residue, 3,4′-diaminodiphenylsulfone residue, 2,2-bis Provided is a laminate, which is at least one divalent group selected from the group consisting of a (4-aminophenyl) propane residue and a divalent group represented by the following general formula (2).

(In General Formula (2), R ³ and R ⁴ each independently represents a hydrogen atom, an alkyl group, or a perfluoroalkyl group.)

One embodiment of the present disclosure provides a laminate in which the functional layer contains a polymer of a polyfunctional (meth) acrylate monomer.

One embodiment of the present disclosure provides a laminate in which the Martens hardness of the surface of the functional layer on the side opposite to the side on which the polyimide film is located is 350 MPa or more and less than 1000 MPa.

1 embodiment of this indication provides the surface material for displays which is a layered product of one embodiment of the above-mentioned this indication.

1 embodiment of this indication provides the surface material for flexible displays which is a layered product of one embodiment of the above-mentioned this indication.

One embodiment of the present disclosure includes the laminate of the one embodiment of the present disclosure;
A transparent electrode having a plurality of conductive portions arranged on one surface side of the laminate;
There is provided a touch panel member comprising a plurality of lead wires electrically connected to at least one side of an end portion of the conductive portion.

One embodiment of the present disclosure includes the laminate of the one embodiment of the present disclosure;
A liquid crystal display unit having a liquid crystal layer disposed between opposing substrates, disposed on one surface side of the laminate;
A liquid crystal display device is provided.

One embodiment of the present disclosure includes the laminate of the one embodiment of the present disclosure;
An organic electroluminescence display unit having an organic electroluminescence layer disposed between opposing substrates, disposed on one surface side of the laminate,
An organic electroluminescence display device is provided.

According to an embodiment of the present disclosure, there are provided a laminate in which bending resistance and adhesion between a functional layer and a polyimide film are improved, and interference fringes are suppressed, and a display surface material that is the laminate. be able to.

It is a schematic sectional view showing an example of a layered product of this indication. It is a figure for demonstrating the method of a static bending test. 2 is a STEM image after staining with ruthenium tetroxide of a cross section of the laminate obtained in Example 1. FIG. 2 is a STEM image before staining with ruthenium tetroxide of the cross section of the laminate obtained in Example 1. FIG. 4 is a STEM image after staining with ruthenium tetroxide of a cross section of the laminate obtained in Example 2. FIG. 3 is a STEM image before staining with ruthenium tetroxide of a cross section of the laminate obtained in Example 2. FIG. 4 is a STEM image after staining with ruthenium tetroxide of a cross section of the laminate obtained in Example 3. FIG. 4 is a STEM image after staining with ruthenium tetroxide of a cross section of a laminate obtained in Comparative Example 2. FIG. 4 is a STEM image before staining with ruthenium tetroxide of a cross section of a laminate obtained in Comparative Example 2. FIG. It is a STEM image after dyeing | staining with the ruthenium tetroxide of the cross section of the laminated body obtained in the comparative example 3. FIG. It is a STEM image after dyeing | staining with the ruthenium tetroxide of the cross section of the laminated body obtained by the comparative example 3 image | photographed with the magnification different from FIG. It is a schematic plan view of one side of an example of the touch panel member of this indication. It is a schematic plan view of the other surface of the touch panel member shown in FIG. FIG. 14 is a cross-sectional view taken along the line A-A ′ of the touch panel member shown in FIGS. 12 and 13. It is a schematic plan view which shows an example of an electroconductive member provided with the laminated body of this indication. It is a schematic plan view which shows another example of an electroconductive member provided with the laminated body of this indication. It is a schematic sectional drawing which shows another example of the touchscreen member of this indication. It is a schematic sectional drawing which shows an example of the liquid crystal display device of this indication. It is a schematic sectional drawing which shows another example of the liquid crystal display device of this indication. It is a schematic sectional drawing which shows an example of the organic electroluminescent display apparatus of this indication. It is a schematic sectional drawing which shows another example of the organic electroluminescent display apparatus of this indication.

I. Laminate The laminate of the present disclosure has a functional layer containing at least one polymer of a radical polymerizable compound and a cationic polymerizable compound via a compatible layer on at least one surface of a polyimide film. ,
The compatible layer contains at least one component of the constituent components of the polyimide film and at least one component of the constituent components of the functional layer,
The said polyimide film is a laminated body containing the polyimide which has a structure represented by following General formula (1).

The laminated body of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view illustrating an example of a laminated body of the present disclosure. A laminated body 10 of the present disclosure shown in FIG. 1 has a functional layer 3 on one surface of a polyimide film 1 with a compatible layer 2 interposed. As shown in FIG. 1, the laminate of the present disclosure may have a functional layer on one surface of the polyimide film via a compatible layer, and although not shown, on both sides of the polyimide film The functional layer may be provided via a compatible layer.

According to the present disclosure, the polyimide contained in the polyimide film included in the laminate has a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, and a diamine residue having a silicon atom in the main chain as a diamine residue. Having a specific structure containing 10 mol% or more and 90 mol% or less of a group and containing 10 mol% or more and 90 mol% or less of a diamine residue having no silicon atom and having an aromatic ring or an aliphatic ring, Between the polyimide film and the functional layer, an interstitial layer containing at least one component of the constituent components of the polyimide film and at least one component of the constituent components of the functional layer intervenes, whereby bending resistance, And the adhesiveness of a functional layer and a polyimide film can be improved, and the laminated body by which generation | occurrence | production of the interference fringe was suppressed can be provided.
About this reason, it estimates as follows.

The present inventors paid attention to polyimide among resins. Polyimide is known to have excellent heat resistance due to its chemical structure. Polyimide film is also known to form an ordered structure with a constant arrangement of molecular chains inside, which makes it possible to restore the flatness and the bent state at a constant cycle at room temperature. It is considered that good results are shown in FIG.
On the other hand, even when the flat state and the folded state are repeated at a constant cycle, if the film is bent for a long time, the film may be folded and may not return flat. In particular, it was confirmed that a polyimide film having high rigidity is difficult to return to a flat state when the film is bent for a long time. Since the bending state is maintained for a long time, the plastic deformation of the film occurs due to the continuous application of tensile stress to the outer periphery of the bending part, which makes it difficult to restore even if the bending force is removed. It is assumed that
Moreover, it can be set as the laminated body which has a desired function by laminating | stacking the functional layer which has functions, such as hard-coat property, on the at least one surface of a polyimide film. However, in the conventional polyimide film, since the static bending resistance of the polyimide film itself is inferior, the laminated body in which the functional layers are further laminated has a problem that the static bending resistance is inferior. In addition, when laminating a functional layer with a conventional polyimide film, it is necessary to provide an adhesive layer between the polyimide film and the functional layer in order to ensure sufficient adhesion between the polyimide film and the functional layer. It was. When the adhesiveness between the polyimide film and the functional layer is insufficient, the functional layer is easily peeled off, is inferior in durability, and is considered to have a quality problem. In addition, in the conventional polyimide film, when the refractive index of the functional layer formed on the polyimide film is different from that of the polyimide film, an interference fringe derived from the difference in refractive index is generated. There was also a problem that visibility when incorporated was lowered.
On the other hand, when using a polyimide in which a specific amount of a flexible molecular skeleton having a silicon atom in the main chain is introduced between molecular skeletons containing an aromatic ring or an aliphatic ring, the present inventors have static bending. In a laminate in which a polyimide film having excellent resistance is obtained and a functional layer containing at least one polymer of a radical polymerizable compound and a cationic polymerizable compound is laminated on the polyimide film, the polyimide film and the function A compatible layer containing a mixture of the components of the polyimide film and the functional layer is interposed between the layers, thereby improving the adhesion between the polyimide film and the functional layer and generating interference fringes. It has been found that a laminate that is suppressed and has improved bending resistance can be obtained. The polyimide film used in the present disclosure introduces a specific amount of a flexible molecular skeleton having a silicon atom in the main chain between rigid molecular skeletons containing an aromatic ring or an aliphatic ring, thereby causing stress due to molecular motion. Since relaxation is possible, the stress applied to the film at the time of bending can be reduced, and it is estimated that the resistance to static bending is improved. Further, in the present disclosure, the polyimide contained in the polyimide film contains a specific amount of a diamine residue having a silicon atom in the main chain, so that the solvent resistance of the polyimide film, and the polyimide film and the functional layer It is considered that the compatibility with the functional layer composition used for formation is appropriate. In the laminate according to the present disclosure, when forming the functional layer, in the step of forming the coating film of the functional layer composition on the polyimide film, a part of the components in the functional layer composition penetrates the polyimide film. A compatible layer is formed by this, and the formed compatible layer is a mixture of a component of the polyimide film and a component of the functional layer appropriately, and optically becomes an intermediate layer of refractive index, It is thought that it will become the aspect excellent in the effect which improves the adhesiveness of a polyimide film and a functional layer, and the effect which suppresses an interference fringe.
Hereinafter, each structure of the laminated body which concerns on this indication is demonstrated in detail.

1. Polyimide film The polyimide film used in the present disclosure contains a polyimide having a structure represented by the general formula (1), and further contains other components as long as the effects of the present disclosure are not impaired. May be.

(Polyimide)
A polyimide is obtained by reacting a tetracarboxylic acid component and a diamine component. It is preferable to obtain imidization by obtaining a polyamic acid by polymerization of a tetracarboxylic acid component and a diamine component. The imidization may be performed by thermal imidization or chemical imidization. Moreover, it can also manufacture by the method which used thermal imidation and chemical imidization together.
The polyimide used in the present disclosure contains a polyimide having a structure represented by the following general formula (1).

Here, the tetracarboxylic acid residue means a residue obtained by removing four carboxyl groups from tetracarboxylic acid, and represents the same structure as a residue obtained by removing acid dianhydride structure from tetracarboxylic dianhydride. .
Moreover, a diamine residue means the residue remove | excluding two amino groups from diamine.

The tetracarboxylic acid residue in R ¹ of the general formula (1) is a residue obtained by removing an acid dianhydride structure from a tetracarboxylic dianhydride having an aromatic ring, or a tetracarboxylic acid having an aliphatic ring. It can be a residue obtained by removing the acid dianhydride structure from the dianhydride.
Examples of the tetracarboxylic dianhydride having an aromatic ring include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3 ′. -Benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis ( 3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3 , 4-Zika Boxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis (2,3 -Dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis [(3,4-dicarboxy) benzoyl] benzene dianhydride, 1,4- Bis [(3,4-dicarboxy) benzoyl] benzene dianhydride, 2,2-bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} propane dianhydride, 2,2-bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} propane dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} ketone dianhydride, bis {4 -[3- (1,2-dicarboxy) Phenoxy] phenyl} ketone dianhydride, 4,4′-bis [4- (1,2-dicarboxy) phenoxy] biphenyl dianhydride, 4,4′-bis [3- (1,2-dicarboxy) Phenoxy] biphenyl dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} ketone dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} Ketone dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} sulfone dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfone Anhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} sulfide dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfide dianhydride 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, 3,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, 3,3 ′-(hexafluoroisopropylidene) diphthalic anhydride, 4′-oxydiphthalic anhydride, 3,4′-oxydiphthalic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, and the like.
Examples of the tetracarboxylic dianhydride having an aliphatic ring include cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, dicyclohexane-3,4,3 ′, 4′-tetracarboxylic acid dianhydride. An anhydride, cyclobutane tetracarboxylic dianhydride, etc. are mentioned.
These may be used alone or in combination of two or more.

The diamine residue having a silicon atom in the main chain in R ² of the general formula (1) can be a residue obtained by removing two amino groups from a diamine having a silicon atom in the main chain. As described above, the polyimide film used in the present disclosure introduces a specific amount of a flexible molecular skeleton having a silicon atom in the main chain between molecular skeletons containing an aromatic ring or an aliphatic ring as a main component. Furthermore, when the bending resistance is improved and the functional layer is laminated, a compatible layer is formed between the functional layer and adhesion with the functional layer and generation of interference fringes can be suppressed.

The diamine residue having a silicon atom in the main chain can be a residue obtained by removing two amino groups from a diamine having a silicon atom in the main chain.
As a diamine residue which has a silicon atom in a principal chain, the diamine represented by the following general formula (A) is mentioned, for example.

(In the general formula (A), each L is independently a direct bond or —O— bond, and each R ¹⁰ may independently have a substituent and contains an oxygen atom or a nitrogen atom. R ¹¹ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and each R ¹¹ independently has a substituent and may contain an oxygen atom or a nitrogen atom. Represents a divalent hydrocarbon group having a number of 1 or more and 20 or less, k is a number of 0 to 200. Plural L, R ¹⁰ and R ¹¹ may be the same or different.

Examples of the monovalent hydrocarbon group represented by R ¹⁰ include an alkyl group having 1 to 20 carbon atoms, an aryl group, and combinations thereof. The alkyl group may be linear, branched or cyclic, and may be linear or a combination of branched and cyclic.
The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, Examples thereof include t-butyl group, pentyl group, hexyl group and the like. The cyclic alkyl group is preferably a cycloalkyl group having 3 to 10 carbon atoms, and specific examples include a cyclopentyl group and a cyclohexyl group. The aryl group is preferably an aryl group having 6 to 12 carbon atoms, and specific examples include a phenyl group, a tolyl group, and a naphthyl group. Further, the monovalent hydrocarbon group represented by R ¹⁰ may be an aralkyl group, and examples thereof include a benzyl group, a phenylethyl group, and a phenylpropyl group.
Examples of the hydrocarbon group that may contain an oxygen atom or a nitrogen atom include an ether bond, a carbonyl bond, an ester bond, an amide bond, and an imino bond between a divalent hydrocarbon group described later and the monovalent hydrocarbon group. And a group bonded with at least one bond (—NH—).
The substituent that the monovalent hydrocarbon group represented by R ¹⁰ may have is not particularly limited as long as the effects of the present disclosure are not impaired. For example, a halogen atom such as a fluorine atom or a chlorine atom And a hydroxyl group.

The monovalent hydrocarbon group represented by R ¹⁰ has from 1 to 3 carbon atoms from the viewpoint of adhesion to the functional layer and interference fringe suppression, as well as improvement in bending resistance and surface hardness. Or an aryl group having 6 to 10 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. The alkyl group having 1 to 3 carbon atoms is more preferably a methyl group, and the aryl group having 6 to 10 carbon atoms is more preferably a phenyl group.

Examples of the divalent hydrocarbon group represented by R ¹¹ include an alkylene group having 1 to 20 carbon atoms, an arylene group, and a combination thereof. The alkylene group may be linear, branched or cyclic, and may be linear or a combination of branched and cyclic.
The alkylene group having 1 to 20 carbon atoms is preferably an alkylene group having 1 to 10 carbon atoms. For example, a linear chain such as a methylene group, an ethylene group, various propylene groups, various butylene groups, or a cyclohexylene group. And a combination of a linear or branched alkylene group and a cyclic alkylene group.
The arylene group is preferably an arylene group having 6 to 12 carbon atoms, and examples of the arylene group include a phenylene group, a biphenylene group, and a naphthylene group, and further have a substituent for an aromatic ring described later. You may do it.
As the divalent hydrocarbon group which may contain an oxygen atom or a nitrogen atom, the divalent hydrocarbon groups may be ether bonds, carbonyl bonds, ester bonds, amide bonds, and imino bonds (—NH—). A group bonded with at least one is exemplified.
The substituent that the divalent hydrocarbon group represented by R ¹¹ may have is the same as the substituent that the monovalent hydrocarbon group represented by R ¹⁰ may have. Good.

The divalent hydrocarbon group represented by R ¹¹ has from 1 to 6 carbon atoms from the viewpoint of adhesion to the functional layer and interference fringe suppression, as well as improvement in bending resistance and surface hardness. Or an arylene group having 6 to 10 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms, and the alkylene group is linear or branched. Preferably there is.

K is a number from 0 to 200. The average of k is preferably 0 or more and 6 or less, and preferably 0 or more and 4 or less, from the viewpoint of adhesion to the functional layer and suppression of interference fringes, and the compatibility between improvement in bending resistance and surface hardness. It is preferable. Among these, k is preferably 0 or 1.

As the diamine residue having a silicon atom in the main chain in R ² , the bending resistance and the adhesion to the functional layer are further improved, and the occurrence of interference fringes is further suppressed. A diamine residue having one or two silicon atoms in the main chain is preferable from the viewpoint of suppressing the decrease.

Examples of the diamine having one silicon atom in the main chain include diamines represented by the following general formula (A-1) where k = 0 among the diamines represented by the general formula (A). . Examples of the diamine having two silicon atoms in the main chain include diamines represented by the following general formula (A-2) in which k = 1 among the diamines represented by the general formula (A). Can be mentioned.

(In the general formula (A-1) and the general formula (A-2), each L is independently a direct bond or —O— bond, and each R ¹⁰ independently has a substituent. And represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, which may contain an oxygen atom or a nitrogen atom, and each R ¹¹ may independently have a substituent, Or a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain a nitrogen atom, and a plurality of L, R ¹⁰ and R ¹¹ may be the same or different.

The molecular weight of the diamine residue having a silicon atom in the main chain is preferably 3000 or less from the viewpoint of adhesion to the functional layer and suppression of interference fringes, and compatibility between improvement in bending resistance and surface hardness. , 2000 or less, preferably 1000 or less, more preferably 800 or less, still more preferably 500 or less, and particularly preferably 300 or less.
The diamine residues having a silicon atom in the main chain can be used alone or in admixture of two or more.

In R ² of the general formula (1), the diamine residue having no aromatic ring and having no silicon atom is a residue obtained by removing two amino groups from a diamine having no silicon atom and having an aromatic ring; can do.
Examples of the diamine having no silicon atom and having an aromatic ring include p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4, 4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone 4,4'-diaminodiphenylsulfone, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzanilide, 3,3'-diaminodiphenylmethane 4,4'-Diaminodiphenylmethane 3,4'-diaminodiphenylmethane, 2,2-di (3-aminophenyl) propane, 2,2-di (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) Propane, 2,2-di (3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-di (4-aminophenyl) -1,1,1,3 , 3,3-hexafluoropropane, 2- (3-aminophenyl) -2- (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 1,1-di (3 -Aminophenyl) -1-phenylethane, 1,1-di (4-aminophenyl) -1-phenylethane, 1- (3-aminophenyl) -1- (4-aminophenyl) -1-phenylethane, 1,3-bis (3-aminopheno B) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3 -Aminobenzoyl) benzene, 1,3-bis (4-aminobenzoyl) benzene, 1,4-bis (3-aminobenzoyl) benzene, 1,4-bis (4-aminobenzoyl) benzene, 1,3-bis (3-amino-α, α-dimethylbenzyl) benzene, 1,3-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (3-amino-α, α-dimethylbenzyl) Benzene, 1,4-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,3-bis (3-amino-α, α-ditrifluoromethylbenzyl) benzene, 1,3-bis ( 4-amino-α, α-ditrifluoromethylbenzyl) benzene, 1,4-bis (3-amino-α, α-ditrifluoromethylbenzyl) benzene, 1,4-bis (4-amino-α, α- Ditrifluoromethylbenzyl) benzene, 2,6-bis (3-aminophenoxy) benzonitrile, 2,6-bis (3-aminophenoxy) pyridine, N, N′-bis (4-aminophenyl) terephthalamide, 9 , 9-bis (4-aminophenyl) fluorene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (2,2-bis ( Trifluoromethyl) benzidine), 3,3′-dichloro-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dimethyl 4,4′-diaminobiphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] Ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3 -Aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) Enyl] propane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) ) Phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (4-amino) Phenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3 -amino Phenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 4,4′-bis [4- (4-aminophenoxy) ) Benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) ) Phenoxy] diphenylsulfone, 4,4′-bis [4- (4-aminophenoxy) phenoxy] diphenylsulfone, 3,3′-diamino-4,4′-diphenoxybenzophenone, 3,3′-diamino-4 , 4′-dibiphenoxybenzophenone, 3,3′-diamino-4-phenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone, 6 6′-bis (3-aminophenoxy) -3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane, 6,6′-bis (4-aminophenoxy) -3,3,3 ′ , 3′-tetramethyl-1,1′-spirobiindane, etc., and a part or all of the hydrogen atoms on the aromatic ring of the diamine are fluoro group, methyl group, methoxy group, trifluoromethyl group, or trifluoromethoxy group Diamines substituted with substituents selected from the group can also be used.
These may be used alone or in combination of two or more.

The diamine residue which does not have a silicon atom and has an aliphatic ring in R ² of the general formula (1) can be a residue obtained by removing two amino groups from a diamine having an aliphatic ring.
Examples of the diamine having an aliphatic ring include 1,4-cyclohexanediamine, trans-1,4-bismethylenecyclohexanediamine, 2,6-bis (aminomethyl) bicyclo [2,2,1] heptane, 2, And 5-bis (aminomethyl) bicyclo [2,2,1] heptane.
These may be used alone or in combination of two or more.

In the polyimide film used in the present disclosure, in R ² of the general formula (1), 10 mol% or more and 90 mol% or less of the total amount of R ² is a diamine residue having a silicon atom in the main chain, and R ² 10 mol% or more and 90 mol% or less of the total amount of bismuth is a diamine residue that does not have a silicon atom and has an aromatic ring or an aliphatic ring. Therefore, the laminate according to the present disclosure improves the adhesion between the polyimide film and the functional layer, has excellent static bending resistance, and suppresses the generation of interference fringes. . R ^{2 in the} general formula (1) is a diamine residue having a silicon atom in the main chain from the viewpoint of further improving adhesion and static bending resistance with a functional layer described later and further suppressing the generation of interference fringes. but is preferably at least 12 mol% of the total amount of R ^2, still preferably at 14 mol% or more, especially from the viewpoint of adhesion to the functional layer is preferably 15 mol% or more. Of these, the R ² of the general formula (1), the main chain of silicon atoms is 1 or 2 with a diamine residue, is preferably at least 12 mol% of the total amount of R ^2, further 14 mol% or more It is preferable that it is more preferably 15 mol% or more. On the other hand, having no silicon atom, a diamine residue having an aromatic ring or an aliphatic ring is preferably It is preferably not more than 88 mole% of the total amount of R ^2, or less more 86 mol%, Furthermore, it is preferable that it is 85 mol% or less. Further, the R ² of the general formula (1) may be from the viewpoint of improving the surface hardness and optical transparency, diamine residue having a silicon atom in the main chain, more than 50 mole% of the total amount of R ² Preferably, it is further preferably 45 mol% or less, and further preferably 40 mol% or less from the viewpoint of optical properties. On the other hand, having no silicon atom, a diamine residue having an aromatic ring or an aliphatic ring is preferably at least 50 mol% of the total amount of R ^2, is preferably further 55 mol% or more.
Incidentally, more than 10 mole% of the total amount of R ² 90 mol% or less, a diamine residue having a silicon atom in the main chain, 90 mol% 10 mol% or more of the total amount of R ² or less, free of silicon atoms If the diamine residue having an aromatic ring or an aliphatic ring is satisfied, R ² in the general formula (1) does not have a diamine residue having a silicon atom in the main chain and a silicon atom. It does not preclude inclusion of another diamine residue different from the diamine residue having an aromatic ring or an aliphatic ring. The other diamine residue is preferably 10 mol% or less of the total amount of R ² , more preferably 5 mol% or less, still more preferably 3 mol% or less, particularly 1 mol%. The following is preferable. Examples of the other diamine residue include a diamine residue that does not have a silicon atom and does not have an aromatic ring or an aliphatic ring.

Among them, more than 10 mole% of the total amount of R ² 90 mol% or less, a diamine residue having a silicon atom in the main chain, of the total amount of R ² (100 mol%), having a silicon atom in the main chain The residue (100% -x%) of the diamine residue mol% (x mol%), which is 10 mol% or more and 90 mol% or less, has no silicon atom and has an aromatic ring or an aliphatic ring. It is preferably a group.
Among them, 10 mol% or more and 90 mol% or less of the total amount of R ² , desirably 12 mol% or more and 90 mol% or less, 14 mol% or more and 90 mol% or less, 15 mol% or more and 90 mol% or less, 10 mol% or more and 50 mol% or less. Mol% or less, 12 mol% or more and 50 mol% or less, 14 mol% or more and 50 mol% or less, or 15 mol% or more and 50 mol% or less are diamine residues having one or two silicon atoms in the main chain. , R ² of the total amount (100 mol%) is 10 mol which is the remainder (100% -x%) of the mol% (x mol%) of the diamine residue having one or two silicon atoms in the main chain % To 90 mol%, preferably 10 mol% to 88 mol%, 10 mol% to 86 mol%, 10 mol% to 85 mol%, 50 mol% to 90 mol%, 50 mol% to 88 mol% Less than mol%, 50% % Or more 86 mol% or less, or 50 mole% or more 85 mol% or less, having no silicon atom, and is preferably a diamine residue having an aromatic ring or an aliphatic ring.

The polyimide having the structure represented by the general formula (1) includes an aromatic ring, and (i) a fluorine atom, in terms of improving light transmittance and improving surface hardness. It is a polyimide containing at least one selected from the group consisting of (ii) an aliphatic ring and (iii) a structure in which aromatic rings are connected to each other by a sulfonyl group or an alkylene group which may be substituted with fluorine. Is preferred. The polyimide having the structure represented by the general formula (1) includes at least one selected from a tetracarboxylic acid residue having an aromatic ring and a diamine residue having an aromatic ring, so that the molecular skeleton becomes rigid. Although the orientation is increased and the surface hardness is improved, the rigid aromatic ring skeleton tends to increase the absorption wavelength to a long wavelength, and tends to decrease the transmittance in the visible light region.
When (i) a fluorine atom is contained in the polyimide, the light transmission is improved because the electronic state in the polyimide skeleton can be hardly transferred.
When (ii) an aliphatic ring is included in the polyimide, light transmittance is improved because the transfer of charges in the skeleton can be inhibited by breaking the π-electron conjugation in the polyimide skeleton.
When (iii) a structure in which aromatic rings are connected to each other by a sulfonyl group or an alkylene group that may be substituted with fluorine is included in the polyimide, the charge transfer in the skeleton is prevented by breaking the π-electron conjugation in the polyimide skeleton. The light transmittance improves from the point which can be inhibited.

As the polyimide having the structure represented by the general formula (1), a polyimide containing a fluorine atom is preferably used from the viewpoint of improving light transmittance and improving surface hardness.
The fluorine atom content ratio is preferably such that the ratio (F / C) of the number of fluorine atoms (F) and the number of carbon atoms (C) measured on the polyimide surface by X-ray photoelectron spectroscopy is 0.01 or more, Further, it is preferably 0.05 or more. On the other hand, if the fluorine atom content is too high, the inherent heat resistance of the polyimide may be lowered, so the ratio (F / C) of the number of fluorine atoms (F) to the number of carbon atoms (C) is 1 or less. Preferably, it is preferably 0.8 or less.
Here, the said ratio by the measurement of X-ray photoelectron spectroscopy (XPS) can be calculated | required from the value of atomic% of each atom measured using an X-ray photoelectron spectrometer (for example, Thermo Scientific Thea Probe). .

Further, the polyimide having the structure represented by the general formula (1), from the viewpoint of improving the surface hardness, the sum of R ¹ and R ² is 100 mole% in the general formula (1), an aromatic The total of the tetracarboxylic acid residue having an aromatic ring and the diamine residue having an aromatic ring is preferably 50 mol% or more, more preferably 60 mol% or more, and 75 mol% or more. Even more preferred.

Further, the polyimide having the structure represented by the general formula (1), from the viewpoint of improving the surface hardness and optical transparency, no tetracarboxylic acid residue of R ^1, and a silicon atom of R ² aromatic It is preferable that at least one of the diamine residues having an aromatic ring or an aliphatic ring includes an aromatic ring and a fluorine atom, and further does not have a tetracarboxylic acid residue of R ¹ and a silicon atom of R ^2. Both of the diamine residues having an aromatic ring or an aliphatic ring preferably contain an aromatic ring and a fluorine atom.
When the polyimide having the structure represented by the general formula (1) is improved in surface hardness and light transmittance, the total of R ¹ and R ² in the general formula (1) is 100 mol%. The total of the tetracarboxylic acid residue having an aromatic ring and a fluorine atom and the diamine residue having an aromatic ring and a fluorine atom is preferably 50 mol% or more, more preferably 60 mol% or more, More preferably, it is 75 mol% or more.

The polyimide having the structure represented by the general formula (1) is a polyimide in which 50% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide are hydrogen atoms directly bonded to the aromatic ring. However, it is preferably used from the viewpoints of improving light transmittance and improving surface hardness. The proportion of hydrogen atoms (number) directly bonded to the aromatic ring in the total hydrogen atoms (number) bonded to carbon atoms contained in the polyimide is preferably 60% or more, and more preferably 70% or more. It is preferable that
When 50% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide is a polyimide that is a hydrogen atom directly bonded to the aromatic ring, the film is stretched at, for example, 200 ° C. or higher even after a heating step in the atmosphere. Is preferable from the viewpoint of little change in optical characteristics, particularly total light transmittance and yellowness YI value. When polyimide is a polyimide in which 50% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide are hydrogen atoms directly bonded to the aromatic ring, the chemical structure of the polyimide changes due to low reactivity with oxygen. It is estimated that it is difficult. Polyimide film uses its high heat resistance and is often used in devices that require processing steps involving heating, but more than 50% of the hydrogen atoms bonded to the carbon atoms contained in the polyimide are in the aromatic ring. In the case of polyimide, which is a hydrogen atom that is directly bonded, there is no need to carry out these subsequent processes in an inert atmosphere in order to maintain transparency, so that the cost of equipment costs and atmospheric control can be suppressed. There is.
Here, the ratio of the hydrogen atoms (number) directly bonded to the aromatic ring in the total hydrogen atoms (number) bonded to the carbon atoms contained in the polyimide is determined by high-performance liquid chromatography or gas chromatography mass of the polyimide decomposition product. It can be determined using an analyzer and NMR. For example, the sample is decomposed with an alkaline aqueous solution or supercritical methanol, and the resulting polyimide decomposition product is separated by high performance liquid chromatography, and the qualitative analysis of each separated peak is performed by a gas chromatograph mass spectrometer and NMR. The ratio of the hydrogen atom (number) directly bonded to the aromatic ring in the total hydrogen atoms (number) contained in the polyimide can be determined by quantification using high performance liquid chromatography.

Among the polyimides having the structure represented by the general formula (1), R ¹ in the general formula (1) is a cyclohexanetetracarboxylic acid dibenzoate from the viewpoint of light transmittance, bending resistance and surface hardness. Anhydrous residue, cyclopentanetetracarboxylic dianhydride residue, dicyclohexane-3,4,3 ', 4'-tetracarboxylic dianhydride residue, cyclobutanetetracarboxylic dianhydride residue, pyromerit Acid dianhydride residue, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride residue, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride residue, 4,4 '-(Hexafluoroisopropylidene) diphthalic anhydride residue, 3,4'-(hexafluoroisopropylidene) diphthalic anhydride residue, 3,3 '-(hexafluoroisopropylidene) diphthalic anhydride residue , It is preferably at least one tetravalent group selected from the group consisting of 4,4′-oxydiphthalic anhydride residue and 3,4′-oxydiphthalic anhydride residue.
In R ¹ , these suitable residues are preferably contained in a total amount of 50 mol% or more, more preferably 70 mol% or more, and still more preferably 90 mol% or more.
In particular, R ¹ in the general formula (1) is 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride residue, 3,4 ′-() because of a good balance between light transmittance and surface hardness. Hexafluoroisopropylidene) diphthalic anhydride residue, 3,3 ′-(hexafluoroisopropylidene) diphthalic anhydride residue, 4,4′-oxydiphthalic anhydride residue, and 3,4′-oxydiphthalate More preferably, it is at least one tetravalent group selected from the group consisting of acid anhydride residues.

R ^{1 in the} general formula (1) includes pyromellitic dianhydride residue, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride residue, and 2,2 ′, 3, A tetracarboxylic acid residue group (group A) suitable for improving rigidity such as at least one selected from the group consisting of 3′-biphenyltetracarboxylic dianhydride residues, Anhydride residue, cyclopentanetetracarboxylic dianhydride residue, dicyclohexane-3,4,3 ′, 4′-tetracarboxylic dianhydride residue, cyclobutanetetracarboxylic dianhydride residue, 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride residue, 3,4'-(hexafluoroisopropylidene) diphthalic anhydride residue, 3,3 '-(hexafluoroisopropylidene) diphthalate Improving light transmittance such as at least one selected from the group consisting of an acid anhydride residue, 4,4′-oxydiphthalic anhydride residue, and 3,4′-oxydiphthalic anhydride residue It is also preferable to use a mixture of tetracarboxylic acid residue groups (group B) suitable for the above. In this case, the content ratio of the tetracarboxylic acid residue group (group A) suitable for improving the rigidity and the tetracarboxylic acid residue group (group B) suitable for improving light transmittance is , 1 mol of tetracarboxylic acid residue group (group B) suitable for improving light transmittance is 0.4% of tetracarboxylic acid residue group (group A) suitable for improving rigidity. It is preferably from 05 mol to 9 mol, more preferably from 0.1 mol to 5 mol, and still more preferably from 0.3 mol to 4 mol.
Among them, the group B includes 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride residues and 3,4 ′-(hexafluoroisopropylidene) diphthalic anhydride residues containing fluorine atoms. It is preferable to use at least one kind from the viewpoint of improving surface hardness and light transmittance.

In the polyimide having the structure represented by the general formula (1), the diamine residue having an aromatic ring or an aliphatic ring in R ² in the general formula (1) is a 1,4-cyclohexanediamine residue, trans-1,4-bismethylenecyclohexanediamine residue, 4,4′-diaminodiphenylsulfone residue, 3,4′-diaminodiphenylsulfone residue, 2,2-bis (4-aminophenyl) propane residue, And at least one divalent group selected from the group consisting of divalent groups represented by the following general formula (2) is preferable from the viewpoints of light transmittance, bending resistance and surface hardness. In particular, from the viewpoint of compatibility between light transmittance and surface hardness, 4,4′-diaminodiphenylsulfone residue, 3,4′-diaminodiphenylsulfone residue, 2,2-bis (4-aminophenyl) It is preferably at least one divalent group selected from the group consisting of a propane residue and a divalent group represented by the following general formula (2), and is represented by the following general formula (2) More preferably, it is a divalent group. As the divalent group represented by the following general formula (2), R ³ and R ⁴ are more preferably a perfluoroalkyl group, and among them, a perfluoroalkyl group having 1 to 3 carbon atoms is preferable. A trifluoromethyl group or a perfluoroethyl group is more preferable. The alkyl group in R ³ and R ⁴ in the following general formula (2) is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group or an ethyl group.

Moreover, the polyimide which has a structure represented by the said General formula (1) is a diamine residue in which the diamine residue which has a silicon atom in the principal chain in R < ² > in the said General formula (1) has two silicon atoms. In view of adhesion to the functional layer, interference fringe suppression, bending resistance and surface hardness, and light transmittance, 1,3-bis (3-aminopropyl) tetramethyldiethyl is further preferred. Siloxane residues, 1,3-bis (4-aminobutyl) tetramethyldisiloxane, 1,3-bis (5-aminopentyl) tetramethyldisiloxane, etc. are compatible with easy availability, light transmission and surface hardness From the viewpoint of

The content ratio of each repeating unit in the polyimide, and the content ratio (mol%) of each tetracarboxylic acid residue or each diamine residue can be determined from the molecular weight of the charge at the time of polyimide production. In addition, the content ratio (mol%) of each tetracarboxylic acid residue and each diamine residue in the polyimide is about high-performance liquid chromatography, gas chromatograph mass spectrometer, NMR for the polyimide degradation product obtained in the same manner as described above. , Elemental analysis, XPS / ESCA and TOF-SIMS.

In the structure represented by the general formula (1), n represents the number of repeating units and is 1 or more.
The number of repeating units n in the polyimide is preferably selected as appropriate according to the structure so as to exhibit a preferable glass transition temperature described later, but is not particularly limited.
The average number of repeating units is usually 10 to 2000, and more preferably 15 to 1000.
R ¹ in each repeating unit may be the same or different, and R ² in each repeating unit may be the same or different.

In addition, the polyimide having the structure represented by the general formula (1) preferably has a number average molecular weight of 10,000 or more, more preferably 20000 or more from the viewpoint of strength and bending resistance when formed into a film. Preferably, it is more preferably 30000 or more, and particularly preferably 50000 or more. The upper limit is not particularly limited, but is preferably 10000000 or less, more preferably 500000 or less, from the viewpoint of easy synthesis and availability.
In addition, the number average molecular weight of a polyimide can be measured similarly to the number average molecular weight of the polyimide precursor mentioned later.

In addition, the polyimide having the structure represented by the general formula (1) preferably has a weight average molecular weight of 20000 or more and 30000 or more from the viewpoint of strength and bending resistance when formed into a film. More preferably, it is more preferably 40000 or more, and particularly preferably 80000 or more. The upper limit is not particularly limited, but is preferably 10000000 or less, more preferably 500000 or less, from the viewpoint of easy synthesis and availability.
The weight average molecular weight of polyimide can be measured by gel permeation chromatography (GPC). Specifically, polyimide is used as an N-methylpyrrolidone (NMP) solution having a concentration of 0.1% by weight, and as a developing solvent, a 30 mmol% LiBr-NMP solution having a water content of 500 ppm or less is used. 8120, column used: GPC LF-804 manufactured by SHODEX), and measurement is performed under the conditions of a sample injection amount of 50 μL, a solvent flow rate of 0.4 mL / min, and 37 ° C. The weight average molecular weight is determined based on a polystyrene standard sample having the same concentration as the sample.

Moreover, as long as the effect of this indication is not impaired, the polyimide used for this indication may have a structure different from the structure represented by the said General formula (1) in the one part. In the polyimide used in the present disclosure, the structure represented by the general formula (1) is preferably 95% or more of the total number of repeating units of the polyimide, more preferably 98% or more, and 100%. Even more preferably.
Examples of the structure different from the structure represented by the general formula (1) include a case where a tetracarboxylic acid residue having no aromatic ring or aliphatic ring is included, and a polyamide structure.
Examples of the polyamide structure that may be included include a polyamideimide structure containing a tricarboxylic acid residue such as trimellitic anhydride and a polyamide structure containing a dicarboxylic acid residue such as terephthalic acid.

The polyimide used in the present disclosure preferably has a glass transition temperature in a temperature range of 150 ° C. or higher and 400 ° C. or lower. When the glass transition temperature is 150 ° C. or higher, heat resistance is excellent, and it is preferably 200 ° C. or higher, and more preferably 250 ° C. or higher. Moreover, when the glass transition temperature is 400 ° C. or lower, the baking temperature can be reduced, and is preferably 380 ° C. or lower. The polyimide used in the present disclosure preferably has one tan δ curve peak in a temperature range of 150 ° C. or higher and 400 ° C. or lower.
In addition, the polyimide used in the present disclosure preferably does not have a tan δ curve peak in a temperature range of −150 ° C. or more and 0 ° C. or less, which can improve the surface hardness of the polyimide film at room temperature. In addition, the polyimide used in the present disclosure may further have a tan δ curve peak in a temperature range of more than 0 ° C. and less than 150 ° C.
The glass transition temperature of the polyimide used in the present disclosure is determined from the peak temperature of the temperature-tan δ (tan δ = loss elastic modulus (E ″) / storage elastic modulus (E ′)) curve obtained by dynamic viscoelasticity measurement. Is. The glass transition temperature of polyimide refers to the temperature of a peak at which the maximum value of the peak is maximum when there are a plurality of tan δ curve peaks.
The glass transition temperature of the polyimide used in the present disclosure can be measured in the same manner as the glass transition temperature of the polyimide film described later.

(Additive)
Moreover, the polyimide film used for this indication may contain the additive further as needed other than the said polyimide. Examples of the additive include inorganic particles, a silica filler for facilitating winding, and a surfactant that improves film-forming properties and defoaming properties.
When the polyimide film used in the present disclosure contains an additive in addition to the polyimide, the content of the additive in the polyimide film is appropriately adjusted depending on the type of the additive and is not particularly limited, but is 30% by mass. Preferably, it is preferably 10% by mass or less, more preferably 5% by mass or less.

(Characteristics of polyimide film)
The polyimide film used in the present disclosure has an internal angle measured in the test when a static bending test is performed according to the following static bending test method from the viewpoint of improving the bending resistance of the laminate according to the present disclosure. It is preferably 120 ° or more, and more preferably 125 ° or more.
[Static bending test method]
A polyimide film test piece cut out to 15 mm × 40 mm is bent at a position of half of the long side, and both ends of the long side of the test piece sandwich a metal piece (100 mm × 30 mm × 6 mm) having a thickness of 6 mm from the upper and lower surfaces. Placed between glass plates (100 mm x 100 mm x 0.7 mm) from above and below with the tape fixed so that the overlap between the top and bottom surfaces of the test piece and the metal piece is 10 mm each. The test piece is fixed in a bent state with an inner diameter of 6 mm. At that time, a dummy test piece is sandwiched between the metal piece and the glass plate where there is no test piece, and is fixed with tape so that the glass plate is parallel. The test piece thus fixed in a bent state is left to stand for 24 hours in an environment of 60 ° C. and 90% relative humidity (RH), and then the glass plate and fixing tape are removed, and the test piece is attached to the test piece. Release this force. Thereafter, one end of the test piece is fixed, and the internal angle of the test piece 30 minutes after the force applied to the test piece is released is measured.

In terms of improving the surface hardness of the laminate according to the present disclosure, the polyimide film used in the present disclosure preferably has a pencil hardness of 2B or higher, more preferably B or higher, and HB or higher. Even more preferred.
The pencil hardness of the polyimide film is determined by adjusting the measurement sample for 2 hours under conditions of a temperature of 25 ° C. and a relative humidity of 60%, and then using a test pencil specified by JIS-S-6006. 4 (1999), a pencil hardness test (0.98N load) is performed on the film surface, and the highest pencil hardness without scratches can be evaluated. For example, a pencil scratch coating film hardness tester manufactured by Toyo Seiki Co., Ltd. can be used.

The polyimide film used in the present disclosure preferably has a total light transmittance of 85% or more measured in accordance with JIS K7361-1, from the viewpoint of improving the transparency of the laminate according to the present disclosure. It is preferably 88% or more, more preferably 89% or more, and particularly preferably 90% or more.
The polyimide film used in the present disclosure has a thickness of 5 μm or more and 100 μm or less, and the total light transmittance measured in accordance with JIS K7361-1 is preferably 85% or more, and more preferably 88% or more. More preferably, it is more preferably 89% or more, and particularly preferably 90% or more.
In addition, the polyimide film used in the present disclosure preferably has a total light transmittance of 85% or more, more preferably 88% or more when measured in accordance with JIS K7361-1 at a thickness of 50 μm ± 5 μm. Is preferable, more preferably 89% or more, and particularly preferably 90% or more.
The total light transmittance measured according to JIS K7361-1 can be measured by, for example, a haze meter (for example, HM150 manufactured by Murakami Color Research Laboratory). In addition, from the measured value of the total light transmittance of a certain thickness, the converted value of the total light transmittance of different thickness can be obtained by Lambert Beer's law and can be used.
Specifically, according to Lambert Beer's law, the transmittance T is
Log ₁₀ (1 / T) = kcb
(K = constant specific to substance, c = concentration, b = optical path length).
In the case of the transmittance of the film, if the density is assumed to be constant even if the film thickness is changed, c is also a constant. Therefore, the above equation is expressed by Log ₁₀ (1 / T) = fb using the constant f.
(F = kc). Here, if the transmittance at a certain film thickness is known, a specific constant f of each substance can be obtained. Therefore, the transmittance at a desired film thickness can be obtained by substituting a constant specific to f and a target film thickness into b using the formula T = 1/10 ^{f · b} .

The polyimide film used in the present disclosure has a yellowness (YI value) calculated in accordance with JIS K7373-2006 of 30 or less from the viewpoint of improving the light transmittance of the laminate according to the present disclosure. Preferably, it is 20 or less, more preferably 15 or less, still more preferably 10 or less.
The polyimide film used in the present disclosure preferably has a yellowness (YI value) calculated in accordance with JIS K7373-2006 of 30 or less and more preferably 20 or less when the thickness is 5 μm or more and 100 μm or less. It is preferably 15 or less, more preferably 10 or less.
The polyimide film used in the present disclosure has a thickness of 50 μm ± 5 μm, and the yellowness (YI value) calculated in accordance with JIS K7373-2006 is preferably 10 or less, preferably 7 or less. Is more preferable, and it is still more preferable that it is 5 or less.
The yellowness (YI value) is determined according to JIS K7373-2006 by using an ultraviolet-visible near-infrared spectrophotometer (for example, JASCO Corporation V-7100) and by a spectrocolorimetric method. C. Using a two-degree field, tristimulus values X, Y, and Z in the XYZ color system are obtained based on transmittance measured at 1 nm intervals in a range of 250 nm to 800 nm, and the X, Y, It can be calculated from the value of Z by the following formula.
YI = 100 (1.2769X−1.0592Z) / Y
It should be noted that, from the measured value of yellowness of a certain thickness, the yellowness of a different thickness is calculated for each transmittance at each wavelength measured at 1 nm intervals between 250 nm and 800 nm of a sample having a specific thickness. Similarly to the light transmittance, a converted value of each transmittance at each wavelength of different thickness can be obtained according to Lambert Beer's law, and can be calculated and used based on it.

In addition, the polyimide film used in the present disclosure is calculated in accordance with JIS K7373-2006 because yellowish coloring is suppressed, light transmittance is improved, and it can be suitably used as a glass substitute material. The value (YI value / film thickness (μm)) obtained by dividing the yellowness (YI value) by the film thickness (μm) is preferably 0.2 or less, more preferably 0.05 or less, and 0 More preferably, it is 0.04 or less.
In the present disclosure, the value obtained by dividing the yellowness (YI value) by the film thickness (μm) (YI value / film thickness (μm)) is the second decimal place according to the rule B of JIS Z8401: 1999. Rounded value.

The polyimide film used in the present disclosure preferably has a haze value of 10 or less, more preferably 8 or less, and more preferably 5 or less from the viewpoint of improving the light transmittance of the laminate according to the present disclosure. Is even more preferable. It is preferable that the haze value can be achieved when the thickness of the polyimide film is 5 μm or more and 100 μm or less.
The haze value can be measured by a method according to JIS K-7105, for example, a haze meter HM150 manufactured by Murakami Color Research Laboratory.

The polyimide film used in the present disclosure preferably has a glass transition temperature in a temperature range of 150 ° C. or higher and 400 ° C. or lower. When the glass transition temperature is 150 ° C. or higher, heat resistance is excellent, and it is preferably 200 ° C. or higher, and more preferably 250 ° C. or higher. Moreover, when the glass transition temperature is 400 ° C. or lower, the baking temperature can be reduced, and is preferably 380 ° C. or lower. Moreover, it is preferable that the polyimide film used for this indication has the peak of one tan-delta curve in the temperature range of 150 to 400 degreeC.
In addition, the polyimide film used in the present disclosure preferably has no tan δ curve peak in a temperature range of −150 ° C. or more and 0 ° C. or less from the viewpoint of excellent surface hardness at room temperature.
The glass transition temperature is obtained from the peak temperature of a temperature-tan δ (tan δ = loss elastic modulus (E ″) / storage elastic modulus (E ′)) curve obtained by dynamic viscoelasticity measurement. The glass transition temperature of polyimide refers to the temperature of a peak at which the maximum value of the peak is maximum when there are a plurality of tan δ curve peaks. As the dynamic viscoelasticity measurement, for example, with a dynamic viscoelasticity measuring device RSA III (TA Instruments Japan Co., Ltd.), the measurement range is set to −150 ° C. to 400 ° C., the frequency is 1 Hz, and the temperature is increased. This can be done at a rate of 5 ° C./min. Further, the measurement can be performed with a sample width of 5 mm and a distance between chucks of 20 mm. When analyzing peaks and inflection points, the data is digitized and analyzed from the numerical values without visual evaluation.
In the present disclosure, the peak of the tan δ curve refers to a peak having an inflection point that is a maximum value and a peak width that is between 3 ° C. or more between peaks and valleys, and is derived from measurement such as noise. The fine vertical fluctuation is not interpreted as the peak.

In addition, the polyimide film used in the present disclosure has a tensile elastic modulus at 25 ° C. of 1.8 GPa measured with a test piece of 15 mm × 40 mm in accordance with JIS K7127, a tensile speed of 10 mm / min, and a distance between chucks of 20 mm. The above is preferable. Thus, since the surface hardness at room temperature is excellent when the tensile modulus at 25 ° C. (room temperature) is high, the surface hardness of the laminate according to the present disclosure is improved. The tensile elastic modulus in the polyimide film used in the present disclosure is more preferably 2.0 GPa or more, and further preferably 2.4 GPa or more.
The tensile elastic modulus was determined by cutting a test piece having a width of 15 mm × a length of 40 mm from a polyimide film using a tensile tester (for example, Shimadzu Corporation: Autograph AG-X 1N, load cell: SBL-1KN) at 25 ° C. The tensile speed can be 10 mm / min, and the distance between chucks can be 20 mm. The polyimide film for obtaining the tensile modulus of elasticity preferably has a thickness of 50 μm ± 5 μm.

In addition, the polyimide film used in the present disclosure preferably has a birefringence in the thickness direction at a wavelength of 590 nm of 0.040 or less. Since the optical distortion of the polyimide film is reduced by having such a birefringence, when the laminate according to the present disclosure is used as a display surface material, it suppresses a decrease in display quality of the display. be able to. The birefringence in the thickness direction at a wavelength of 590 nm in the polyimide film used in the present disclosure is preferably smaller, more preferably 0.020 or less, more preferably 0.015 or less, and further preferably It is preferably 010 or less, and more preferably less than 0.008. In addition, when a film having a birefringence in the thickness direction at a wavelength of 590 nm of more than 0.040 is placed on the display surface and the display is viewed with polarized sunglasses, rainbow unevenness may occur and visibility may be reduced. is there. On the other hand, if the birefringence in the thickness direction of the film placed on the display surface is 0.040 or less, the occurrence of rainbow unevenness when viewing the display with polarized sunglasses is suppressed. Furthermore, when the birefringence in the thickness direction of the film placed on the display surface is 0.020 or less, color reproducibility when the display is viewed from an oblique direction is improved.
In addition, the birefringence of the thickness direction in the said wavelength 590nm of the polyimide film used for this indication can be calculated | required as follows.
First, the thickness direction retardation value (Rth) of the polyimide film is measured with a light of 25 ° C. and a wavelength of 590 nm using a phase difference measuring apparatus (for example, product name “KOBRA-WR” manufactured by Oji Scientific Instruments). To do. For the thickness direction retardation value (Rth), a phase difference value at 0 degree incidence and a phase difference value at an incidence angle of 40 degrees are measured, and the thickness direction retardation value Rth is calculated from these phase difference values. The phase difference value at an oblique incidence of 40 degrees is measured by making light having a wavelength of 590 nm incident on the polyimide film from a direction inclined by 40 degrees from the normal line of the polyimide film.
The birefringence in the thickness direction of the polyimide film can be determined by substituting it into the formula: Rth / d. Said d represents the film thickness (nm) of a polyimide film.
The thickness direction retardation value is nx the refractive index in the slow axis direction in the in-plane direction of the film (the direction in which the refractive index in the film in-plane direction is maximum), and the fast axis direction in the film plane (film surface). Rth [nm] = {(nx + ny) / 2−nz} × d, where ny is the refractive index in the direction in which the refractive index in the inner direction is the minimum) and nz is the refractive index in the thickness direction of the film. be able to.

Moreover, the polyimide film used for this indication is a silicon atom (Si) atom of the film surface measured by the X ray photoelectron spectroscopy from the point of adhesiveness with a functional layer, and the point of interference fringe suppression of a laminated body. % Is preferably from 0.1 to 10, more preferably from 0.2 to 5.
Here, the said ratio by the measurement of X-ray photoelectron spectroscopy (XPS) can be calculated | required from the value of atomic% of each atom measured using an X-ray photoelectron spectrometer (for example, Thermo Scientific Thea Probe). .

As a preferred embodiment, the ratio (F / C) of the number of fluorine atoms (F) and the number of carbon atoms (C) on the film surface, measured by X-ray photoelectron spectroscopy of a polyimide film, is 0.01 or more and 1 or less. It is preferable that it is 0.05 or more and 0.8 or less.
The ratio (F / N) of the number of fluorine atoms (F) and the number of nitrogen atoms (N) on the film surface, measured by X-ray photoelectron spectroscopy of the polyimide film, is preferably 0.1 or more and 20 or less. Further, it is preferably 0.5 or more and 15 or less.
Further, the ratio (F / Si) of the number of fluorine atoms (F) and the number of silicon atoms (Si) on the film surface, measured by X-ray photoelectron spectroscopy of the polyimide film, is preferably 1 or more and 50 or less. It is preferably 3 or more and 30 or less.

Further, the thickness of the polyimide film used in the present disclosure may be appropriately selected depending on the use of the laminate, but is preferably 1 μm or more, more preferably 5 μm or more, and further more preferably 10 μm or more. It is preferable. On the other hand, it is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less. If the thickness of the polyimide film is too thin, the strength is reduced and the film tends to break. If the thickness of the polyimide film is too thick, the bending resistance may be reduced.

(Production method of polyimide film)
As a manufacturing method of the polyimide film used in the present disclosure, for example, as a first manufacturing method,
A step of preparing a polyimide precursor resin composition containing a polyimide precursor having a structure represented by the following general formula (1 ′) and an organic solvent (hereinafter referred to as a polyimide precursor resin composition preparation step);
Applying the polyimide precursor resin composition to a support to form a polyimide precursor resin coating film (hereinafter referred to as a polyimide precursor resin coating film forming process);
The process of imidating the said polyimide precursor by heating (henceforth an imidation process) and the manufacturing method of the polyimide film containing are mentioned.

(In the general formula (1 ′), R ¹ , R ² and n are the same as those in the general formula (1).)

In the first production method, the step of stretching at least one of the polyimide precursor resin coating film and the imidized coating film obtained by imidizing the polyimide precursor resin coating film (hereinafter referred to as stretching process). ).
Hereinafter, each step will be described in detail.

(1) Polyimide precursor resin composition preparation step The polyimide precursor resin composition prepared in the first production method includes a polyimide precursor having a structure represented by the general formula (1 ′), an organic solvent, And may contain additives as required.

<Polyimide precursor>
The polyimide precursor of this indication suitable for manufacturing the polyimide film thru | or polyimide used for this indication is a polyimide precursor which has a structure represented by the said General formula (1 ').
The polyimide precursor having the structure represented by the general formula (1 ′) includes a tetracarboxylic acid component that becomes a tetracarboxylic acid residue in R ¹ of the general formula (1 ′), and the general formula (1 ′). a polyamic acid obtained in the R ² by polymerization of a diamine residues become diamine component.
Here, as R ¹ , R ² and n in the general formula (1 ′), those similar to R ¹ , R ² and n in the general formula (1) described in the polyimide can be used.

The polyimide precursor having the structure represented by the general formula (1 ′) preferably has a number average molecular weight of 10,000 or more, and 20,000 or more from the viewpoint of strength and bending resistance when formed into a film. More preferably, it is more preferably 30000 or more, and particularly preferably 50000 or more. On the other hand, if the number average molecular weight is too large, the viscosity becomes high and the workability such as filtration may be reduced, and therefore it is preferably 10000000 or less, and more preferably 500000 or less.
The number average molecular weight of the polyimide precursor can be determined by NMR (for example, AVANCE III manufactured by BRUKER). For example, a polyimide precursor solution is applied to a glass plate and dried at 100 ° C. for 5 minutes, and then 10 mg of solid content is dissolved in 7.5 ml of dimethyl sulfoxide-d6 solvent, and NMR measurement is performed to bond to an aromatic ring. The number average molecular weight can be calculated from the peak intensity ratio of hydrogen atoms.

In addition, the polyimide precursor having the structure represented by the general formula (1 ′) preferably has a weight average molecular weight of 20000 or more and 30000 or more from the viewpoint of strength and bending resistance when used as a film. More preferably, it is more preferably 40000 or more, and particularly preferably 80000 or more. On the other hand, when the weight average molecular weight is too large, the viscosity becomes high and the workability such as filtration may be reduced, and therefore it is preferably 10000000 or less, and more preferably 500000 or less.
The weight average molecular weight of the polyimide precursor can be measured by gel permeation chromatography (GPC). Specifically, the polyimide precursor was made into an N-methylpyrrolidone (NMP) solution having a concentration of 0.5% by weight, and the developing solvent was a 10 mmol% LiBr-NMP solution having a water content of 500 ppm or less. Using HLC-8120, column used: GPC LF-804 manufactured by SHODEX, measurement is performed under the conditions of a sample injection amount of 50 μL, a solvent flow rate of 0.5 mL / min, and 40 ° C. The weight average molecular weight is determined based on a polystyrene standard sample having the same concentration as the sample.

The polyimide precursor solution is obtained by reacting the above tetracarboxylic dianhydride and the above diamine in a solvent. The solvent used for the synthesis of the polyimide precursor (polyamic acid) is not particularly limited as long as it can dissolve the above-described tetracarboxylic dianhydride and diamine. For example, an aprotic polar solvent or a water-soluble alcohol solvent is used. Can be used. In the present disclosure, among others, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, 1,3-dimethyl-2-imidazolidinone, etc. It is preferable to use an organic solvent containing a nitrogen atom of γ-butyrolactone or the like. In particular, when the polyimide precursor solution (polyamic acid solution) is used as it is for the preparation of the polyimide precursor resin composition, it is preferable to use an organic solvent containing a nitrogen atom, among which N, N-dimethylacetamide, N— It is preferable to use methyl-2-pyrrolidone or a combination thereof. The organic solvent is a solvent containing carbon atoms.

The polyimide precursor solution is prepared by combining at least two kinds of diamines. An acid dianhydride may be added to a mixed solution of at least two kinds of diamines to synthesize polyamic acid, or at least Two kinds of diamine components may be added to the reaction solution step by step at an appropriate molar ratio, and the sequence in which each raw material is incorporated into the polymer chain may be controlled to some extent.
For example, an acid dianhydride having a molar ratio of 0.5 equivalent of a diamine having a silicon atom in the main chain is charged into a reaction solution in which a diamine having a silicon atom in the main chain is dissolved, and reacted. Amidic acid in which a diamine having a silicon atom in the main chain was reacted at both ends of the anhydride was synthesized, and all or part of the remaining diamine was added thereto, and acid dianhydride was added to polymerize the polyamic acid. Also good. When polymerized by this method, a diamine having a silicon atom in the main chain is introduced into the polyamic acid in a linked form via one acid dianhydride.
Polymerization of the polyamic acid by such a method is preferable because the positional relationship of the amic acid having a silicon atom in the main chain is specified to some extent, and it is easy to obtain a film having excellent bending resistance while maintaining the surface hardness.

When the number of moles of diamine in the polyimide precursor solution (polyamic acid solution) is X and the number of moles of tetracarboxylic dianhydride is Y, Y / X may be 0.9 or more and 1.1 or less. Preferably, it is 0.95 or more and 1.05 or less, more preferably 0.97 or more and 1.03 or less, and particularly preferably 0.99 or more and 1.01 or less. By setting it as such a range, the molecular weight (polymerization degree) of the polyamic acid obtained can be adjusted moderately.
The procedure of the polymerization reaction can be appropriately selected from known methods and is not particularly limited.
Moreover, the polyimide precursor solution obtained by the synthesis reaction may be used as it is, and other components may be mixed there if necessary. The solvent of the polyimide precursor solution is dried and dissolved in another solvent. It may be used.

The viscosity of the polyimide precursor solution at 25 ° C. is preferably 500 cps or more and 200,000 cps or less from the viewpoint of forming a uniform coating film and a polyimide film.
The viscosity of the polyimide precursor solution can be measured at 25 ° C. using a viscometer (for example, TVE-22HT, Toki Sangyo Co., Ltd.).

<Polyimide precursor resin composition>
As said polyimide precursor resin composition, the said polyimide precursor solution may be used and the additive may be contained as needed. Examples of the additive include inorganic particles, silica filler for facilitating winding, a surfactant for improving film forming property and defoaming property, and the like described in the above polyimide film. Similar ones can be used.

The organic solvent used in the polyimide precursor resin composition is not particularly limited as long as the polyimide precursor can be dissolved. For example, containing nitrogen atoms such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, 1,3-dimethyl-2-imidazolidinone Organic solvent: γ-butyrolactone or the like can be used, and among them, an organic solvent containing a nitrogen atom is preferably used.

Content of the said polyimide precursor in the said polyimide precursor resin composition is 50 mass% or more in solid content of a resin composition from the point which forms the polyimide film which has a uniform coating film and the intensity | strength which can be handled. Preferably, it is preferably 60% by mass or more, more preferably 70% by mass or more, and further preferably 90% by mass or more, and the upper limit may be appropriately adjusted depending on the components contained.
In addition, in this indication, solid content means components other than a solvent.
The organic solvent in the polyimide precursor resin composition is preferably 40% by mass or more and more preferably 50% by mass or more in the resin composition from the viewpoint of forming a uniform coating film and a polyimide film. Preferably, it is 99% by mass or less.

The polyimide precursor resin composition preferably has a moisture content of 1000 ppm or less from the viewpoint of improving the storage stability of the polyimide precursor resin composition and improving the productivity. If the polyimide precursor resin composition contains a large amount of moisture, the polyimide precursor may be easily decomposed.
The water content of the polyimide precursor resin composition can be determined using a Karl Fischer moisture meter (for example, a trace moisture measuring device CA-200, manufactured by Mitsubishi Chemical Corporation).
As described above, in order to control the water content to 1000 ppm or less, it is preferable to dehydrate the organic solvent to be used or use a water whose amount is controlled and handle it in an environment with a humidity of 5% or less.

The viscosity of the polyimide precursor resin composition at 25 ° C. is preferably 500 cps or more and 200,000 cps or less from the viewpoint of forming a uniform coating film and a polyimide film.
The viscosity of the polyimide precursor resin composition can be measured using a viscometer (eg, TVE-22HT, Toki Sangyo Co., Ltd.) at 25 ° C. and a sample amount of 0.8 ml.

(2) Polyimide precursor resin coating film forming step In the step of applying the polyimide precursor resin composition to a support to form a polyimide precursor resin coating film, the support used has a smooth surface and heat resistance. The material is not particularly limited as long as the material is resistant and solvent resistant. For example, an inorganic material such as a glass plate, a metal plate having a mirror-finished surface, and the like can be given. The shape of the support is selected depending on the coating method, and may be, for example, a plate shape, a drum shape, a belt shape, a sheet shape that can be wound around a roll, or the like.

The application means is not particularly limited as long as it can be applied at a desired film thickness, and for example, a known one such as a die coater, comma coater, roll coater, gravure coater, curtain coater, spray coater, lip coater or the like can be used. .
Application may be performed by a single-wafer coating apparatus or a roll-to-roll coating apparatus.

After the polyimide precursor resin composition is applied to the support, the solvent in the coating film is dried at a temperature of 150 ° C. or lower, preferably 30 ° C. or higher and 120 ° C. or lower until the coating film is tack-free. By setting the drying temperature of the solvent to 150 ° C. or lower, imidization of the polyamic acid can be suppressed.

The drying time may be appropriately adjusted according to the film thickness of the polyimide precursor resin coating film, the type of solvent, the drying temperature, etc., but is usually 30 seconds to 240 minutes, preferably 1 minute to 180 minutes, more preferably. Is preferably 90 seconds to 120 minutes. When exceeding an upper limit, it is unpreferable from the surface of the production efficiency of a polyimide film. On the other hand, when the value is below the lower limit, the appearance of the resulting polyimide film may be affected by rapid solvent drying.

The method for drying the solvent is not particularly limited as long as the solvent can be dried at the above temperature. For example, an oven, a drying furnace, a hot plate, infrared heating, or the like can be used.
When high management of optical properties is required, the atmosphere during drying of the solvent is preferably an inert gas atmosphere. The inert gas atmosphere is preferably a nitrogen atmosphere, the oxygen concentration is preferably 500 ppm or less, more preferably 100 ppm or less, and most preferably 50 ppm or less. When heat treatment is performed in the atmosphere, the film may be oxidized and colored, or the performance may deteriorate.

(3) Imidization process In said 1st manufacturing method, the said polyimide precursor is imidized by heating.
In the said manufacturing method, when it has an extending process, an imidation process may be performed with respect to the polyimide precursor in the said polyimide precursor resin coating film before an extending process, and the said polyimide precursor resin after an extending process You may perform with respect to the polyimide precursor in a coating film, and with respect to both the polyimide precursor in the said polyimide precursor resin coating film before an extending process, and the polyimide precursor which exists in the film | membrane after an extending process. You can go.

The imidization temperature may be appropriately selected according to the structure of the polyimide precursor.
Usually, the temperature rise start temperature is preferably 30 ° C. or higher, more preferably 100 ° C. or higher. On the other hand, the temperature rise end temperature is preferably 250 ° C. or higher.

The rate of temperature increase is preferably selected as appropriate depending on the film thickness of the polyimide film to be obtained. When the film thickness of the polyimide film is thick, it is preferable to decrease the temperature increase rate.
From the viewpoint of the production efficiency of the polyimide film, it is preferably 5 ° C./min or more, more preferably 10 ° C./min or more. On the other hand, the upper limit of the heating rate is usually 50 ° C./min, preferably 40 ° C./min or less, more preferably 30 ° C./min or less. It is preferable to set the temperature increase rate from the viewpoint that the appearance defect and strength reduction of the film can be suppressed, and the whitening associated with the imidization reaction can be controlled, and the light transmittance is improved.

The temperature increase may be continuous or stepwise, but it is preferable to make it continuous from the viewpoint of controlling the appearance of the film, suppressing the strength reduction, and controlling the whitening associated with the imidization reaction. Moreover, in the above-mentioned whole temperature range, the temperature rising rate may be constant or may be changed in the middle.

The atmosphere at the time of temperature increase in imidation is preferably an inert gas atmosphere. The inert gas atmosphere is preferably a nitrogen atmosphere, the oxygen concentration is preferably 500 ppm or less, more preferably 200 ppm or less, and even more preferably 100 ppm or less. When heat treatment is performed in the atmosphere, the film may be oxidized and colored, or the performance may deteriorate.
However, when 50% or more of the hydrogen atoms bonded to the carbon atoms contained in the polyimide are hydrogen atoms directly bonded to the aromatic ring, there is little influence of oxygen on the optical properties, and an inert gas atmosphere is not used. In addition, a polyimide having a high light transmittance can be obtained.

The heating method for imidation is not particularly limited as long as the temperature can be raised at the above temperature. For example, an oven, a heating furnace, infrared heating, electromagnetic induction heating, or the like can be used.

Especially, it is more preferable that the imidation ratio of a polyimide precursor shall be 50% or more before an extending process. Even if the imidization rate is 50% or more before the stretching step, the film is stretched after the step, and then heated at a higher temperature for a certain period of time to perform imidization. Whitening is suppressed. In particular, from the point that the surface hardness of the polyimide film is improved, it is preferable that the imidization rate is 80% or more in the imidization step before the stretching step, and the reaction is allowed to proceed to 90% or more, and further to 100%. Is preferred. By stretching after imidization, it is presumed that the surface hardness is improved because a rigid polymer chain is easily oriented.
The imidation rate can be measured by analyzing the spectrum by infrared measurement (IR).

In order to obtain a final polyimide film, it is preferable to proceed the reaction to 90% or more, further 95% or more, and further 100%.
In order to allow the reaction to proceed to 90% or more, more preferably 100%, it is preferable to hold at a temperature rising end temperature for a certain period of time. Minutes are preferred.

(4) Stretching step The first production method includes a stretching step of stretching at least one of the polyimide precursor resin coating film and a post-imidation coating film obtained by imidizing the polyimide precursor resin coating film. It may be. When it has the said extending | stretching process, it is preferable from the point which the surface hardness of a polyimide film improves including the process of extending | stretching the coating film after imidation especially.

In the first production method, it is preferable to perform the step of stretching 101% or more and 10000% or less while heating at 80 ° C. or higher when the initial dimension before stretching is 100%.
The heating temperature during stretching is preferably in the range of glass transition temperature ± 50 ° C. of the polyimide or polyimide precursor, and preferably in the range of glass transition temperature ± 40 ° C. If the stretching temperature is too low, the film may not be deformed and the orientation may not be sufficiently induced. On the other hand, if the stretching temperature is too high, the orientation obtained by stretching is relaxed by the temperature, and there is a possibility that sufficient orientation cannot be obtained.
The stretching step may be performed simultaneously with the imidization step. Stretching the film after imidization after imidation rate of 80% or more, further 90% or more, even more 95% or more, and particularly substantially 100% imidation improves the surface hardness of the polyimide film. It is preferable from the point.

The draw ratio of the polyimide film is preferably from 101% to 10,000%, more preferably from 101% to 500%. By stretching in the above range, the surface hardness of the obtained polyimide film can be further improved.

The method for fixing the polyimide film during stretching is not particularly limited, and is selected according to the type of stretching apparatus. Moreover, there is no restriction | limiting in particular in the extending | stretching method, For example, it can extend | stretch through a heating furnace using the extending | stretching apparatus which has conveyance apparatuses, such as a tenter. The polyimide film may be stretched only in one direction (longitudinal stretching or lateral stretching), or may be stretched in two directions by simultaneous biaxial stretching, sequential biaxial stretching, oblique stretching, or the like.

The first production method is preferable from the viewpoint of easily reducing the birefringence of the polyimide film. According to the first production method, a polyimide film having a birefringence in the thickness direction at a wavelength of 590 nm of 0.020 or less, further 0.010 or less can be suitably formed.

Moreover, as a manufacturing method of the polyimide film used for this indication, as a 2nd manufacturing method,
A step of preparing a polyimide resin composition containing a polyimide having a structure represented by the general formula (1) and an organic solvent (hereinafter referred to as a polyimide resin composition preparation step);
The polyimide resin composition is applied to a support, the solvent is dried, and a polyimide resin coating film is formed (hereinafter referred to as a polyimide resin coating film forming process).

When the polyimide having the structure represented by the general formula (1) dissolves well in an organic solvent, the polyimide is not dissolved in the polyimide precursor resin composition, and the additive is added as necessary. A polyimide resin composition containing bismuth can also be suitably used.
In the case where the polyimide having the structure represented by the general formula (1) has solvent solubility such that 5% by mass or more is dissolved in an organic solvent at 25 ° C., the production method can be suitably used.

In the polyimide resin composition preparation step, the polyimide having the structure represented by the general formula (1) is selected from the polyimides having the solvent solubility described above from the same polyimides described in the polyimide film. Can be used. As a method for imidization, chemical deimidation using a chemical imidizing agent is used instead of heat dehydration for the dehydration and cyclization reaction of the polyimide precursor having the structure represented by the general formula (1 ′). Is preferred. In the case of performing chemical imidization, known compounds such as amines such as pyridine and β-picolinic acid, carbodiimides such as dicyclohexylcarbodiimide, and acid anhydrides such as acetic anhydride may be used as a dehydration catalyst. Examples of the acid anhydride are not limited to acetic anhydride, and propionic acid anhydride, n-butyric acid anhydride, benzoic acid anhydride, trifluoroacetic acid anhydride, and the like, but are not particularly limited. At that time, a tertiary amine such as pyridine or β-picolinic acid may be used in combination. However, when these amines remain in the film, the optical properties, particularly the yellowness (YI value), are reduced. Therefore, the reaction liquid reacted from the precursor to the polyimide is not cast as it is, It is preferable to form the film after purification by reprecipitation or the like, and removing components other than polyimide to 100 ppm or less of the total weight of the polyimide.

In the polyimide resin composition preparation step, as the organic solvent used in the reaction solution for chemical imidization of the polyimide precursor, for example, those described in the polyimide precursor resin composition preparation step in the first production method Similar ones can be used. Examples of the organic solvent used when redissolving the polyimide purified from the reaction solution in the polyimide resin composition preparation step include ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol mono-normal-butyl ether, Ethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ortho-dichlorobenzene, xylene, cresol, chlorobenzene, isobutyl acetate, isopentyl acetate, normal-butyl acetate, normal-propyl acetate, normal-pentyl acetate, cyclohexanol, cyclohexanone, 1.4-Dioxane, tetrachloroethylene, toluene, methyl isobutyl ketone, methylcyclohexanol, methylcyclohexane Sanone, methyl-normal-butyl ketone, dichloromethane, dichloroethane, and mixed solvents thereof are mentioned. Among them, at least one selected from the group consisting of dichloromethane, normal-butyl acetate, propylene glycol monomethyl ether acetate, and mixed solvents thereof is used. It can be preferably used.

The polyimide resin composition may contain an additive as necessary. As said additive, the thing similar to what was demonstrated in the said polyimide precursor resin composition preparation process in said 1st manufacturing method can be used.
In the second method, the method of setting the moisture content of the polyimide resin composition to 1000 ppm or less is the same method as the method described in the polyimide precursor resin composition preparation step in the first production method. Can be used.

In the polyimide resin coating film forming step in the second manufacturing method, the support and the coating method are the same as those described in the polyimide precursor resin coating film forming step in the first manufacturing method. be able to.
In the polyimide resin coating film forming step in the second production method, the drying temperature is preferably 80 ° C. or higher and 150 ° C. or lower under normal pressure. It is preferable that the pressure be in the range of 10 ° C. to 100 ° C. under reduced pressure.

Further, the second production method may have a stretching step of stretching the polyimide resin coating film after the polyimide resin coating film forming step. The said extending process can be made to be the same as the extending process in said 1st manufacturing method.

In addition, the polyimide film used in the present disclosure may be subjected to surface treatment such as saponification treatment, glow discharge treatment, corona discharge treatment, ultraviolet treatment, flame treatment, and the like.

The second production method is preferable from the viewpoint of easily reducing the yellowness (YI value) of the polyimide film. According to the second manufacturing method, it is possible to suitably form a polyimide film having a value obtained by dividing the yellowness calculated in accordance with JIS K7373-2006 by the film thickness (μm) of 0.04 or less. is there.
The second production method is preferable from the viewpoint of easily increasing the thickness of the compatible layer and improving the adhesion with the functional layer. According to the second production method, the compatible layer dyed in the cross section in the thickness direction of the laminate dyed with at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate. The polyimide film having a thickness of 5 nm or more and having a portion exceeding 10 nm can be suitably formed.

2. Functional layer The functional layer included in the laminate according to the present disclosure is a layer intended to exhibit some function, and specifically includes, for example, hard coat properties, antireflection properties, antistatic properties, and antifouling properties. And the like, and a known functional layer can be used.
In particular, the functional layer used in the present disclosure preferably functions as a hard coat layer from the viewpoint of improving the surface hardness of the laminate according to the present disclosure. Here, the “hard coat layer” is a layer for improving the surface hardness, and specifically, a hardness of “H” or higher in a pencil hardness test defined in JIS 5600-5-4 (1999). Means something.

The functional layer used in the present disclosure contains at least one polymer of a radically polymerizable compound and a cationically polymerizable compound as a binder component, and as long as the effects of the present disclosure are not impaired, An optional additive component may be contained. Here, in the polymer contained in the functional layer, at least one of a radical polymerizable compound and a cationic polymerizable compound in the functional layer composition described later is polymerized in a curing step when the functional layer is formed. And a polymer obtained by polymerizing at least one of a radically polymerizable compound and a cationically polymerizable compound in advance before forming the functional layer are included in the functional layer composition. It is preferable that at least one of the radically polymerizable compound and the cationically polymerizable compound is a polymer obtained by polymerization in a curing step when forming the functional layer.
Moreover, the functional layer used for this indication may contain the unreacted monomer, oligomer, etc. other than the said polymer as a binder component in the range by which an effect is not impaired.

(At least one polymer of a radical polymerizable compound and a cationic polymerizable compound)
At least one polymer of a radical polymerizable compound and a cationic polymerizable compound is polymerized by a known method using at least one of a radical polymerizable compound and a cationic polymerizable compound, if necessary, using a polymerization initiator. Can be obtained.

The radical polymerizable compound is a compound having a radical polymerizable group. The radical polymerizable group possessed by the radical polymerizable compound is not particularly limited as long as it is a functional group capable of causing a radical polymerization reaction, and examples thereof include a group containing a carbon-carbon unsaturated double bond. Specific examples include a vinyl group and a (meth) acryloyl group. When the radical polymerizable compound has two or more radical polymerizable groups, these radical polymerizable groups may be the same or different from each other.

The number of radical polymerizable groups contained in one molecule of the radical polymerizable compound is preferably 2 or more, more preferably 3 or more, from the viewpoint of improving the hardness of the functional layer.
As the radical polymerizable compound, a compound having a (meth) acryloyl group is preferable from the viewpoint of high reactivity. For example, urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, melamine A polyfunctional (meth) acrylate having a molecular weight of several hundreds to several thousands having several (meth) acryloyl groups in a molecule called (meth) acrylate, polyfluoroalkyl (meth) acrylate, silicone (meth) acrylate, etc. Monomers and oligomers can be preferably used, and polyfunctional (meth) acrylate polymers having two or more (meth) acryloyl groups in the side chain of the acrylate polymer can also be preferably used. Especially, the polyfunctional (meth) acrylate monomer which has a 2 or more (meth) acryloyl group in 1 molecule can be used preferably. When the functional layer contains a polymer of the polyfunctional (meth) acrylate monomer, it is possible to improve the hardness of the functional layer, further improve the adhesion, and suppress the occurrence of interference fringes. Moreover, the polyfunctional (meth) acrylate oligomer or polymer which has a 2 or more (meth) acryloyl group in 1 molecule can also be used preferably. The functional layer contains the polyfunctional (meth) acrylate oligomer or polymer, thereby improving the hardness and bending resistance of the functional layer, further improving the adhesion and suppressing the occurrence of interference fringes. Can do.
In this specification, (meth) acryloyl represents each of acryloyl and methacryloyl, and (meth) acrylate represents each of acrylate and methacrylate.

Examples of the polyfunctional (meth) acrylate monomer include trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and pentaerythritol tris. (Meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) Acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa ) Acrylate, tetrapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, di Glycerin tetra (meth) acrylate, adamantyl di (meth) acrylate, isoboronyl di (meth) acrylate, dicyclopentanedi (meth) acrylate, tricyclodecane di (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and these Examples thereof include those modified with PO, EO, caprolactone and the like. Among them, those having 3 to 6 (meth) acryloyl groups in one molecule are preferable from the viewpoint of high reactivity, improving the hardness of the functional layer, and adhesion and interference fringe suppression. , Pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), pentaerythritol tetraacrylate (PETTA), dipentaerythritol pentaacrylate (DPPA), trimethylolpropane tri (meth) acrylate, tripentaerythritol octa (meta) ) Acrylate, tetrapentaerythritol deca (meth) acrylate, etc. can be preferably used, and in particular, selected from pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate. At least one is preferable.

In the present disclosure, the radical polymerizable compound may include a monofunctional (meth) acrylate monomer for adjusting the hardness and viscosity of the functional layer composition, improving adhesion, suppressing interference fringes, and the like. . Examples of the monofunctional (meth) acrylate monomer include hydroxyethyl acrylate (HEA), glycidyl methacrylate, methoxypolyethylene glycol (meth) acrylate, isostearyl (meth) acrylate, 2-acryloyloxyethyl succinate, acryloylmorpholine, N -Acryloyloxyethyl hexahydrophthalimide, cyclohexyl acrylate, tetrahydrofuryl acrylate, isobornyl acrylate, phenoxyethyl acrylate, adamantyl acrylate and the like.

The cationic polymerizable compound is a compound having a cationic polymerizable group. The cationic polymerizable group possessed by the cationic polymerizable compound is not particularly limited as long as it is a functional group capable of causing a cationic polymerization reaction, and examples thereof include an epoxy group, an oxetanyl group, and a vinyl ether group. When the cationic polymerizable compound has two or more cationic polymerizable groups, these cationic polymerizable groups may be the same or different from each other.

The number of cationically polymerizable groups contained in one molecule of the cationically polymerizable compound is preferably 2 or more, more preferably 3 or more, from the viewpoint of improving the hardness of the functional layer.
Moreover, as the cationic polymerizable compound, among them, a compound having at least one of an epoxy group and an oxetanyl group as a cationic polymerizable group is preferable, and has at least one of an epoxy group and an oxetanyl group in one molecule. Compounds are more preferred. Cyclic ether groups such as epoxy groups and oxetanyl groups are preferred from the viewpoint of small shrinkage accompanying the polymerization reaction. In addition, compounds having an epoxy group among the cyclic ether groups are easily available as compounds having various structures, do not adversely affect the durability of the obtained functional layer, and can easily control the compatibility with the radical polymerizable compound. There are advantages. Of the cyclic ether groups, the oxetanyl group has a high degree of polymerization and low toxicity as compared with the epoxy group. When the obtained functional layer is combined with a compound having an epoxy group, a cation in the coating film is obtained. There are advantages such as speeding up the network formation obtained from the polymerizable compound and forming an independent network without leaving unreacted monomer in the film even in a region mixed with the radical polymerizable compound.

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

Examples of the alicyclic epoxy resin include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (UVR-6105, UVR-6107, UVR-6110), bis-3,4-epoxycyclohexylmethyl adipate. (UVR-6128) (The product names in parentheses are manufactured by Dow Chemical.)

Examples of the glycidyl ether type epoxy resin include sorbitol polyglycidyl ether (Denacol EX-611, Denacol EX-612, Denacol EX-614, Denacol EX-614B, Denacol EX-622), Polyglycerol polyglycidyl ether (Denacol EX). -512, Denacol EX-521), pentaerythritol polyglycidyl ether (Denacol EX-411), diglycerol polyglycidyl ether (Denacol EX-421), glycerol polyglycidyl ether (Denacol EX-313, Denacol EX-314), Trimethylolpropane polyglycidyl ether (Denacol EX-321), resortinol diglycidyl ether (Denacol EX-201), neopentyl glycol diglycol Dil ether (Denacol EX-211), 1,6 hexanediol diglycidyl ether (Denacol EX-212), hydrodibisphenol A diglycidyl ether (Denacol EX-252), ethylene glycol diglycidyl ether (Denacol EX-810, Denacol) EX-811), polyethylene glycol diglycidyl ether (Denacol EX-850, Denacol EX-851, Denacol EX-821), propylene glycol glycidyl ether (Denacol EX-911), polypropylene glycol glycidyl ether (Denacol EX-941, Denacol EX) -920), allyl glycidyl ether (Denacol EX-111), 2-ethylhexyl glycidyl ether (Denacol EX-121), phenyl glycidyl ether (Denacol EX-141), phenol glycidyl ether (Denacol EX-145), butylphenyl glycidyl ether (Denacol EX-146), diglycidyl phthalate (Denacol EX-721), hydroquinone diglycidyl ether (Denacol EX-203), Diglycidyl terephthalate (Denacol EX-711), glycidyl phthalimide (Denacol EX-731), dibromophenyl glycidyl ether (Denacol EX-147), dibromoneopentylglycol diglycidyl ether (Denacol EX-221) The name is made by Nagase ChemteX).

Other commercially available epoxy resins include trade names such as Epicoat 825, Epicoat 827, Epicoat 828, Epicoat 828EL, Epicoat 828XA, Epicoat 834, Epicoat 801, Epicoat 801P, Epicoat 802, Epicoat 815, Epicoat 815XA, Epicoat 816A, Epicoat 819, Epicoat 834X90, Epicoat 1001B80, Epicoat 1001X70, Epicoat 1001X75, Epicoat 1001T75, Epicoat 806, Epicoat 806P, Epicoat 807, Epicoat 152, Epicoat 154, Epicoat 871, Epicoat 191P, Epicoat YX310, Epicoat DX255, Epicoat YX8000, Etc. (above product name, Turbocharger bread epoxy resin) and the like.

Examples of the cationically polymerizable compound having an oxetanyl group include 3-ethyl-3-hydroxymethyloxetane (OXT-101) and 1,4-bis-3-ethyloxetane-3-ylmethoxymethylbenzene (OXT-121). Bis-1-ethyl-3-oxetanyl methyl ether (OXT-221), 3-ethyl-3--2-ethylhexyloxymethyl oxetane (OXT-212), 3-ethyl-3-phenoxymethyl oxetane (OXT- 211) (the name in parentheses is a product name manufactured by Toa Gosei Co., Ltd.), and the product names Etanacol EHO, Etanacol OXBP, Etanacol OXTP, Etanacol OXMA (above, trade name, manufactured by Ube Industries).

The radically polymerizable compound and the cationically polymerizable compound preferably have a weight average molecular weight of 1,000 or more and 20,000 or less from the viewpoint of easily forming a compatible layer and improving the hardness of the resin cured layer. , More preferably 1000 or more and 10,000 or less, and still more preferably 2000 or more and 7000 or less.
In addition, a weight average molecular weight is calculated | required as a standard polystyrene conversion value by gel permeation chromatography (GPC).

The functional layer preferably contains a polymer of the radical polymerizable compound from the viewpoint of hardness, adhesion, and interference fringe suppression, and contains a polymer of the polyfunctional (meth) acrylate monomer. More preferably.
Moreover, the content ratio of the polymer of the polyfunctional (meth) acrylate monomer is 45% by mass in a total amount of 100% by mass of at least one polymer of the radical polymerizable compound and the cationic polymerizable compound contained in the functional layer. It is preferable that it is the above, and it is more preferable that it is 50 mass% or more.

Among the binder components contained in the functional layer, as a binder component different from the polymer of the polyfunctional (meth) acrylate monomer, in terms of surface hardness and bending resistance, a polymer of polyfunctional urethane (meth) acrylate, and A polymer of polyfunctional (meth) acrylate and polyfunctional urethane (meth) acrylate is preferred.
As the polyfunctional urethane (meth) acrylate, those having 5 or more functionalities and having a weight average molecular weight of 1000 or more and 10,000 or less are preferable from the viewpoint of surface hardness and bending resistance.
As polyfunctional urethane (meth) acrylate, you may use a commercial item, for example, Nippon Synthetic Chemical Industry Co., Ltd. product: UV1700B (molecular weight 2000, 10 functional), UV6300B (molecular weight 3700, 7 functional), and UV7640B (molecular weight). 1500, 7 functional), manufactured by Nippon Kayaku Co., Ltd .: DPHA40H (molecular weight 7000, 8 functional), UX5000 (molecular weight 1000, 5 functional) and UX5001T (molecular weight 6200, 8 functional), manufactured by Negami Kogyo Co., Ltd .: UN3320HS ( Molecular weight 5000, 15 functional), UN904 (molecular weight 4900, 10 functional), UN3320HC (molecular weight 1500, 6 functional) and UN3320HA (molecular weight 1500, 6 functional), Arakawa Chemical Industries, Ltd .: BS577 (molecular weight 1000, 6 functional) And Shin-Nakamura Chemical Co., Ltd .: U15H 15 functional) and U6H (6 functional), and the like.

The total content of the radically polymerizable compound and the cationically polymerizable compound in the functional layer is selected from the viewpoints of the surface hardness and adhesion of the functional layer, and the occurrence of interference fringes. When the layer does not contain inorganic or organic fine particles described later, it is preferably 45% by mass or more, more preferably 50% by mass or more, and when the functional layer contains inorganic or organic fine particles described later. 30% by mass or more, and more preferably 40% by mass or more. The upper limit of the total content of at least one polymer of the radical polymerizable compound and the cationic polymerizable compound in the functional layer is not particularly limited, but when the functional layer contains inorganic or organic fine particles described later, the fine particles Is preferably 60% by mass or less, and more preferably 50% by mass or less, from the viewpoint of fully containing the above-described effect.

(Optional additive)
The optional additive component is appropriately selected according to the function to be imparted to the functional layer, and is not particularly limited. For example, inorganic or organic fine particles for adjusting the hardness and refractive index, an ultraviolet absorber, an infrared absorber, a protective agent Examples include glazes, antifouling agents, antistatic agents, and leveling agents, surfactants, lubricants, various sensitizers, flame retardants, adhesion promoters, polymerization inhibitors, antioxidants, and surface modifiers. An agent or the like may be included.

In the case where the functional layer is a hard coat layer, the functional layer composition preferably contains inorganic or organic fine particles, and more preferably contains inorganic fine particles, from the viewpoint of improving the hardness. On the other hand, organic fine particles can be preferably used from the viewpoint of imparting antiglare property.

Examples of the inorganic fine particles include metal oxides such as silica (SiO ₂ ), aluminum oxide, zirconia, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, and cerium oxide. Examples include fine particles, metal fluoride fine particles such as magnesium fluoride and sodium fluoride, metal fine particles, metal sulfide fine particles, metal nitride fine particles, etc. Among them, metal oxide fine particles are preferable, and are selected from silica fine particles and aluminum oxide fine particles. At least one type is more preferable, and silica fine particles are still more preferable.

Further, the inorganic fine particles have a photoreactive property capable of forming a covalent bond by crosslinking reaction between the inorganic fine particles or at least one of the radical polymerizable compound and the cationic polymerizable compound on the surface of the inorganic fine particles. Reactive inorganic fine particles having a reactive functional group having at least a part of the particle surface are preferable. The hardness of the hard coat film can be further improved by a cross-linking reaction between the reactive inorganic fine particles or the reactive inorganic fine particles and at least one of the radical polymerizable compound and the cationic polymerizable compound.

The reactive inorganic fine particles have at least a part of the surface coated with an organic component, and have a reactive functional group introduced by the organic component on the surface. Here, the organic component is a component containing carbon. In addition, as an aspect in which at least a part of the surface is coated with an organic component, for example, a compound containing an organic component such as a silane coupling agent reacts with a hydroxyl group present on the surface of the inorganic fine particles to cause a part of the surface In addition to the mode in which the organic component is bonded to the surface, or the mode in which the organic component having an isocyanate group reacts with the hydroxyl group present on the surface of the inorganic fine particles, the organic component is bonded to a part of the surface. Examples include an aspect in which an organic component is attached to a hydroxyl group present on the surface of the inorganic fine particle by an interaction such as hydrogen bonding, and an aspect in which one or two or more inorganic fine particles are contained in the polymer particle. Moreover, as said reactive functional group, ethylenically unsaturated bonds, such as a (meth) acryloyl group, a vinyl group, an allyl group, an epoxy group, etc. are mentioned, for example.

Among the reactive inorganic fine particles, reactive silica fine particles are particularly preferable. As the reactive silica fine particles, conventionally known fine particles can be used, and examples thereof include reactive silica fine particles described in JP-A-2008-165040. Also, particles (reactive atypical silica fine particles) in which silica fine particles described in JP-A-2009-108123 are linked in a chain and surface-treated with a silane coupling agent can be used. Examples of commercially available reactive silica fine particles include Nissan Chemical Industries, Ltd .; MIBK-SD, MIBK-SDMS, MIBK-SDL, MIBK-SDZL, JGC Catalysts &Chemicals; V8802, V8803, and the like.

Examples of the organic fine particles include plastic beads. Specific examples of the plastic beads include styrene beads, melamine beads, acrylic beads, acrylic-styrene beads, polycarbonate beads, and polyethylene beads.

In addition, the inorganic or organic fine particles use solid particles that do not have pores or a porous structure inside the particles, such as hollow particles, to improve the hardness. From the point of view, it is preferable.

The average particle diameter of the inorganic or organic fine particles is preferably 5 nm or more, more preferably 10 nm or more from the viewpoint of improving the hardness, and more preferably 100 nm or less from the viewpoint of transparency. More preferably, it is 50 nm or less.
The average particle diameter of the inorganic or organic fine particles can be measured by observing a cross section of the functional layer with an electron microscope. The average particle diameter of 10 arbitrarily selected fine particles is defined as the average particle diameter.

In the present disclosure, as the inorganic or organic fine particles, those having a single material and a single average particle diameter may be used, or two or more kinds having different materials or average particle diameters may be used in combination. . When two or more kinds of fine particles having different average particle diameters are used in combination, the average particle diameter of the various fine particles is preferably within the above range.

When the functional layer contains the inorganic or organic fine particles, the total content of the inorganic or organic fine particles in the functional layer is preferably 25% by mass or more and 30% by mass or more from the viewpoint of imparting hardness. More preferably, it is preferably 60% by mass or less, and more preferably 50% by mass or less. When the content of the inorganic or organic fine particles is too large, the filling rate is excessively increased, which may reduce the hardness of the functional layer.

(Configuration of functional layer)
The thickness of the functional layer included in the multilayer body according to the present disclosure may be appropriately selected depending on the function of the functional layer and the use of the multilayer body. However, in order to exhibit the function of the functional layer, each functional layer has a thickness of 2 μm. Preferably, it is preferably 3 μm or more. On the other hand, it is preferably 50 μm or less, more preferably 30 μm or less, from the viewpoint of bending resistance and thinning of the laminate. Further, it is preferably 20 μm or less, more preferably 10 μm or less.
In addition, the thickness of each layer which the laminated body which concerns on this indication has is the thickness direction of the laminated body observed with a transmission electron microscope (TEM), a scanning electron microscope (SEM), or a scanning transmission electron microscope (STEM). It can be measured from the cross section.

Moreover, the functional layer included in the laminate of the present disclosure may have not only a single layer but also a multilayer configuration of two or more layers.
When the laminate according to the present disclosure has two or more functional layers, the total thickness of the functional layers is not particularly limited, but is 50 μm or less from the viewpoint of bending resistance and thinning of the laminate. Is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less. The lower limit of the total thickness of the functional layer is not particularly limited, but is preferably 2 μm or more and more preferably 3 μm or more from the viewpoint of exerting the function of the functional layer.

As a preferable layer configuration in the case of having two or more functional layers, for example, the functional layer adjacent to the compatible layer is a functional layer containing the inorganic or organic fine particles, and is on the side opposite to the compatible layer. The functional layer located on the outermost surface is preferably a functional layer containing an antifouling agent from the viewpoint of improving the hard coat property and antifouling property of the laminate of the present disclosure.

In addition, the functional layer included in the laminate according to the present disclosure has a Martens hardness of 350 MPa or more and less than 1000 MPa on the surface of the functional layer on the side opposite to the side where the polyimide film is located from the viewpoint of surface hardness and bending resistance. Preferably, it is 350 MPa or more and 600 MPa or less, more preferably 375 MPa or more and 575 MPa or less.
The Martens hardness can be adjusted by the composition of the functional layer. For example, the Martens hardness can be increased by increasing the content of inorganic or organic fine particles.
The Martens hardness is a hardness when an indenter is pressed by a hardness measurement by a nanoindentation method, and can be performed by using, for example, “TI950 TriboIndenter” manufactured by HYSITRON. Specifically, a triangular pyramid-shaped indenter is pushed into the surface of the laminated body on the functional layer side, and after holding and relaxing the residual stress, unloading, measuring the maximum load after relaxation, The Martens hardness can be calculated from P _max / A using the maximum load (P _max (μN)) and the indentation depth (A (nm ² )).

(Method for forming functional layer)
In the laminate according to the present disclosure, the functional layer is, for example,
Forming a coating film of a functional layer composition containing at least one of a radical polymerizable compound and a cationic polymerizable compound on at least one surface of the polyimide film;
And a step of curing the coating film of the functional layer composition.

(1) The process of forming the coating film of the composition for functional layers The composition for functional layers used for formation of the said functional layer contains at least 1 sort (s) of a radically polymerizable compound and a cationically polymerizable compound, and is further needed. Accordingly, it contains a polymerization initiator, a solvent, and other optional components.

At least one of the radical polymerizable compound and the cationic polymerizable compound contained in the functional layer composition is as described above.
The total content of at least one of the radically polymerizable compound and the cationically polymerizable compound in the functional layer composition improves the surface hardness of the functional layer and improves the adhesion of the functional layer by easily forming a compatible layer. In terms of improving and suppressing the occurrence of interference fringes, when the functional layer composition does not contain inorganic or organic fine particles, it is preferably 45% by mass or more in the total solid content of the functional layer composition. 50% by mass or more, and when the functional layer contains inorganic or organic fine particles, the total solid content of the functional layer composition is preferably 30% by mass or more, and 40% by mass. More preferably. The upper limit of the total content of the radical polymerizable compound and the cationic polymerizable compound is not particularly limited, but when the functional layer composition contains inorganic or organic fine particles, the total solid content of the functional layer composition The content is preferably 60% by mass or less, and more preferably 50% by mass or less.

The functional layer composition may contain a polymerization initiator as necessary.
As the polymerization initiator, radical polymerization initiators, cationic polymerization initiators, radicals and cationic polymerization initiators can be appropriately selected and used. These polymerization initiators are decomposed by at least one of light irradiation and heating to generate radicals or cations to advance radical polymerization and cationic polymerization.

The radical polymerization initiator may be any substance that can release a substance that initiates radical polymerization by light irradiation and / or heating. For example, photo radical polymerization initiators include imidazole derivatives, bisimidazole derivatives, N-aryl glycine derivatives, organic azide compounds, titanocenes, aluminate complexes, organic peroxides, N-alkoxypyridinium salts, thioxanthone derivatives, and the like. More specifically, 1,3-di (tert-butyldioxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetrakis (tert-butyldioxycarbonyl) benzophenone, 3-phenyl-5- Isoxazolone, 2-mercaptobenzimidazole, bis (2,4,5-triphenyl) imidazole, 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name Irgacure 651, Ciba Japan Co., Ltd.) 1-hydroxy-cyclohexyl-phenyl Ketone (trade name Irgacure 184, manufactured by Ciba Japan), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (trade names Irgacure 369, Ciba Japan ( Bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium) (trade name Irgacure 784) However, it is not limited to these.

In addition to the above, commercially available products can be used. Specifically, Irgacure 907, Irgacure 379, Irgacure 819, Irgacure 127, Irgacure 500, Irgacure 754, Irgacure 250, Irgacure 1800, Irgacure 1870 manufactured by Ciba Japan Co., Ltd. , Irgacure OXE01, DAROCUR TPO, DAROCUR1173, Japan Siber Hegner Co., Ltd. of SpeedcureMBB, SpeedcurePBZ, SpeedcureITX, SpeedcureCTX, SpeedcureEDB, Esacure ONE, Esacure KIP150, Esacure KTO46, manufactured by Nippon Kayaku Co., of (stock) KAYACURE DETX-S, KAYACURE CTX , KAYACURE BMS, KAYACURE DMBI, etc. may be mentioned.

Moreover, the cationic polymerization initiator should just be able to discharge | release the substance which starts cationic polymerization by at least any one of light irradiation and a heating. Examples of the cationic polymerization initiator include sulfonic acid ester, imide sulfonate, dialkyl-4-hydroxysulfonium salt, arylsulfonic acid-p-nitrobenzyl ester, silanol-aluminum complex, (η ⁶ -benzene) (η ⁵ -cyclopentadidiene). Enyl) iron (II) and the like, and more specific examples include, but are not limited to, benzoin tosylate, 2,5-dinitrobenzyl tosylate, N-tosiphthalimide and the like.

Examples of radical polymerization initiators that can be used as cationic polymerization initiators include aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic phosphonium salts, triazine compounds, iron arene complexes, and the like. More specifically, iodonium chloride such as diphenyliodonium, ditolyliodonium, bis (p-tert-butylphenyl) iodonium, bis (p-chlorophenyl) iodonium, bromide, borofluoride, hexafluorophosphate salt, hexafluoro Iodonium salts such as antimonate salts, chlorides of sulfonium such as triphenylsulfonium, 4-tert-butyltriphenylsulfonium, tris (4-methylphenyl) sulfonium, bromide, borofluoride, hexa Sulfonium salts such as fluorophosphate salts and hexafluoroantimonate salts, 2,4,6-tris (trichloromethyl) -1,3,5-triazine, 2-phenyl-4,6-bis (trichloromethyl) -1, 2,4,6-substituted-1,3,5 triazine compounds such as 3,5-triazine, 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, etc. It is not limited to these.

The content of the polymerization initiator is not particularly limited, but a total of 100 of the radical polymerizable compound and the cationic polymerizable compound from the viewpoint of sufficiently causing a polymerization reaction and sufficient hardness of the functional layer. It is preferable that they are 0.5 mass part or more and 10.0 mass parts or less with respect to a mass part.

As the solvent used in the functional layer composition, a solvent capable of dispersing or dissolving each component contained in the functional layer composition can be appropriately selected and used, and is not particularly limited. Alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol; acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl isobutyl ketone, diacetone alcohol, cyclohepta Non-, ketones such as diethyl ketone; ethers such as 1,4-dioxane, dioxolane, diisopropyl ether dioxane, tetrahydrofuran; methyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl lactate, etc. Stealtes; Aliphatic hydrocarbons such as hexane; Cycloaliphatic hydrocarbons such as cyclohexane; Aromatic hydrocarbons such as toluene and xylene; Halogenated carbons such as dichloromethane and dichloroethane; Methyl formate, Methyl acetate, Acetic acid Esters such as ethyl, propyl acetate, butyl acetate and ethyl lactate; cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; cellosolve acetates; sulfoxides such as dimethylsulfoxide; amides such as dimethylformamide and dimethylacetamide; Phenols such as orthochlorophenol can be exemplified, and a mixture thereof may be used.
As the solvent used for the functional layer composition, methyl isobutyl ketone is particularly preferable because a compatible layer is easily formed, adhesion between the functional layer and the polyimide film is improved, and generation of interference fringes is easily suppressed. And a solvent containing at least one selected from methyl ethyl ketone. Further, the total content of at least one selected from methyl isobutyl ketone and methyl ethyl ketone is preferably 50% by mass or more, more preferably 70% by mass or more, and 90% by mass or more based on the entire solvent. It is even more preferable.

The content of the solvent in the functional layer composition is such that a compatible layer is easily formed, the adhesion between the functional layer and the polyimide film is improved, and the occurrence of interference fringes is easily suppressed. It is preferable that it is 30 to 70 mass% with respect to the whole thing, and it is more preferable that it is 35 to 60 mass%.

Examples of other optional additive components that can be contained in the functional layer composition include the same optional additive components that can be contained in the functional layer described above.
In the functional layer composition, the inorganic or organic fine particles contained as an optional additive component are 50% when the fine particles in the composition are measured by a dynamic light scattering method and the particle size distribution is expressed as a cumulative distribution. The particle diameter (d50 median diameter) is preferably 5 nm or more from the viewpoint of improving hardness, and is preferably 10 nm or more. On the other hand, from the viewpoint of transparency, it is preferably 100 nm or less, and 50 nm or less. More preferably.
The median diameter can be measured using a Microtrac particle size analyzer or a Nanotrac particle size analyzer manufactured by Nikkiso Co., Ltd.
The inorganic or organic fine particles preferably have a narrow particle size distribution and are monodispersed from the viewpoint of transparency and hardness.

When the functional layer composition contains the inorganic or organic fine particles, the total content of the inorganic or organic fine particles in the functional layer composition is given to the total solid content of the functional layer composition. From the viewpoint, it is preferably 25% by mass or more, more preferably 30% by mass or more, and on the other hand, it is preferably 60% by mass or less, and more preferably 50% by mass or less.

As a method for forming a coating film of the functional layer composition on at least one surface of the polyimide film, for example, the functional layer composition is applied to at least one surface of the polyimide film by a known coating means. The method of doing is mentioned.
The application means is not particularly limited as long as it is a method that can be applied with a target film thickness, and examples thereof include the same means as the means for applying the polyimide precursor resin composition to a support.

After applying the functional layer composition, if necessary, the solvent is removed by drying to form a coating film of the functional layer composition. Examples of the drying method include reduced-pressure drying or heat drying, and a combination of these drying methods. Moreover, when drying at a normal pressure, it is preferable to dry at 30 degreeC or more and 110 degrees C or less.

(2) The step of curing the coating film of the functional layer composition In the step of curing the coating layer of the functional layer composition, the radical polymerizable compound and the cationic polymerizable compound contained in the functional layer composition Depending on the polymerizable group, the coating film can be cured by at least one of light irradiation and heating. By curing the coating film, at least one of the radical polymerizable compound and the cation polymerizable compound in the functional layer composition is polymerized to form a polymer, and the radical polymerizable compound and the cation are generated. A functional layer containing at least one polymer of a polymerizable compound can be formed.

For light irradiation, ultraviolet rays, visible light, electron beams, ionizing radiation, etc. are mainly used. In the case of ultraviolet curing, ultraviolet rays emitted from light such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp are used. The amount of irradiation with the energy radiation source of accumulative exposure at an ultraviolet wavelength of 365 nm, a degree 50 mJ / cm ² or more 5000 mJ / cm ² or less.
When heating, the treatment is usually performed at a temperature of 40 ° C. or higher and 120 ° C. or lower. Moreover, you may react by leaving it to stand for 24 hours or more at room temperature (25 degreeC).

Further, in the step of curing the coating film of the functional layer composition, the oxygen concentration is preferably 300 ppm or less from the viewpoint of preventing inhibition of the curing reaction of the coating film due to oxygen. Is more preferably performed under a condition of 200 ppm or less.

As a method for forming a functional layer having a two-layer structure, for example,
Forming a coating film of a first functional layer composition comprising at least one of a radical polymerizable compound and a cationic polymerizable compound on at least one surface of the polyimide film;
Forming a coating film of the second functional layer composition containing at least one of a radical polymerizable compound and a cationic polymerizable compound on the surface of the coating film of the first functional layer composition;
And a method of curing the coating film of the first functional layer composition and the coating film of the second functional layer composition.
As a method of forming a functional layer having a multilayer structure of three or more layers, for example, in the method described above, after the step of forming a coating film of the second functional layer composition, further on the coating film, The method which has the process of laminating | stacking the coating film of the composition for desired functional layers, and the process of hardening | curing each coating film laminated | stacked on the polyimide film is mentioned.
In the method of forming a functional layer having a multilayer structure, after the step of forming a coating film of each functional layer composition, before forming a coating film of another functional layer composition on the coating film It may have a step of semi-curing or curing the coating film, and it is preferable from the viewpoint of adhesion to have a step of semi-curing. For example, when forming a functional layer having a two-layer structure, specifically, for the first functional layer including at least one of a radical polymerizable compound and a cationic polymerizable compound on at least one surface of the polyimide film. Forming a coating film of the composition;
A step of semi-curing the coating film of the first functional layer composition;
A coating film of the second functional layer composition containing at least one of a radical polymerizable compound and a cationic polymerizable compound is formed on the surface of the semi-cured coating film of the first functional layer composition. Process,
A method comprising a step of curing the semi-cured coating film of the first functional layer composition and the coating film of the second functional layer composition is preferable.

3. Compatible Layer The laminate of the present disclosure has the functional layer on at least one surface of the polyimide film via the compatible layer, and the compatible layer is at least one component of the polyimide film. And at least one component of the constituent components of the functional layer. That is, the compatible layer is a layer containing at least one component among the same components as the constituent components of the polyimide film and at least one component among the same components as the constituent components of the functional layer. When the functional layer has a multilayer structure of two or more layers, at least one component of the functional layer contained in the compatible layer is a function located adjacent to the compatible layer. It is at least one component among the same components as the constituent components of the layer.
Moreover, from the point of the adhesiveness of a polyimide film and a functional layer, and the point which suppresses generation | occurrence | production of an interference fringe, at least 1 sort (s) of the component of the said polyimide film which the said compatible layer contains contains a polyimide. It is preferred that at least one component of the functional layer contained in the compatible layer contains at least one polymer of a radical polymerizable compound and a cationic polymerizable compound.
When the compatible layer forms the functional layer, in the step of forming a coating film of the functional layer composition on at least one surface of the polyimide film, 1 part of the component in the functional layer composition Is formed by penetrating into the polyimide film.
The laminate according to the present disclosure has a compatible layer between the polyimide film and the functional layer, thereby improving the adhesion between the functional layer and the polyimide film, suppressing the occurrence of interference fringes, and bending resistance. Is an improvement.

The compatible layer preferably has no discontinuity between the polyimide film and the functional layer in terms of adhesion between the functional layer and the polyimide film, interference fringe suppression, and bending resistance. In any part of the laminate, the thickness of the compatible layer is preferably 1 nm or more, more preferably 3 nm or more, and even more preferably 5 nm or more.

The compatible layer is a layer observed as a dyed layer in the cross section in the thickness direction of the laminate dyed with at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate. It is preferable. Here, the dyed layer refers to a layer colored by dyeing.
At least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide, and tungsten phosphate has a large molecular mobility such as an amorphous part and easily enters and reacts with a low density part. The compatible layer is formed when the functional layer composition permeates the polyimide film surface when the functional layer is formed on the polyimide film containing the polyimide represented by the general formula (1). Therefore, it is considered that the area to be the compatible layer is a low density area due to a moderate decrease in the density of polyimide due to the penetration of the functional layer composition. It is considered that at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate can selectively dye the compatible layer by adhering to the low density region. In the present disclosure, it is preferable to use at least one selected from ruthenium tetroxide and osmium tetroxide, and more preferably ruthenium tetroxide.

As a method for staining a compatible layer in a cross section in the thickness direction of the laminate with at least one dyeing reagent selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate, for example, the lamination according to the present disclosure After the sample cut into a 2 mm x 10 mm strip is solidified and fixed with resin, it is cut in the thickness direction of the fixed sample with a width of about 50 nm to 150 nm using a microtome. A method of staining the prepared ultrathin sections by placing them in a container together with at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate, and allowing them to stand at room temperature (25 ° C.) for a certain period of time. Is mentioned. The standing time can be adjusted as appropriate, and is not particularly limited, but may be, for example, 10 minutes or more and 60 minutes or less. The ultrathin section is placed in a container together with at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate, sealed, allowed to stand for a certain period of time, and then the staining reagent remaining in the sample is added. In order to remove, the container lid may be opened and left for a certain period of time. The time to leave the container after it is opened can be adjusted as appropriate, and is not particularly limited, but can be, for example, 5 minutes or more and 30 minutes or less.
The stained compatible layer can be observed by observing the stained ultrathin section with an electron microscope such as a scanning transmission electron microscope (STEM).

Further, in the cross section in the thickness direction of the laminate dyed with at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate, the thickness of the dyed compatible layer is the functional layer and polyimide From the viewpoint of adhesion to the film, suppression of interference fringes, and bending resistance, the thickness is preferably 3 nm or more, more preferably 5 nm or more, and even more preferably 7 nm or more. From the same point, the thickness of the compatible layer dyed with at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate is preferably 3 μm or less, preferably 1 μm or less. More preferably, it is more preferably 500 nm or less, and may be 300 nm or less or 100 nm or less. The thickness of the dyed compatible layer having a portion exceeding 10 nm, more preferably having a portion exceeding 15 nm is preferable from the viewpoint of improving adhesion.
In addition, it is preferable that the thickness of the dye | stained compatible layer exists in the said range in the arbitrary locations of a laminated body.

4). Configuration of Laminate The overall thickness of the laminate according to the present disclosure may be appropriately selected depending on the application, but is preferably 10 μm or more, and more preferably 40 μm or more from the viewpoint of strength. On the other hand, from the viewpoint of bending resistance, it is preferably 300 μm or less, more preferably 200 μm or less, and still more preferably 100 μm or less.

Moreover, in the laminate according to the present disclosure, the ratio of the total thickness of the functional layer and the compatible layer with respect to the total thickness of the laminate is in terms of surface hardness, and adhesion and interference fringe suppression. It is preferably 10% or more, more preferably 15% or more. On the other hand, from the viewpoint of bending resistance, it is preferably 30% or less, and more preferably 20% or less.

In addition, the laminated body which concerns on this indication should just have the said functional layer in the at least one surface of the said polyimide film through the said compatible layer, ie, on the at least one surface of the said polyimide film. As long as the compatible layer and the functional layer are adjacent to each other in this order, other layers may be included as long as the effects of the present disclosure are not impaired.

5). Characteristics of Laminated Body The laminated body according to the present disclosure preferably has an internal angle measured by the test of 120 ° or more when a static bending test is performed from the viewpoint of excellent bending resistance. In addition, the method of a static bending test can be made the same method as the static bending test of the polyimide film mentioned above. In the static bending test of the laminate, the laminate is bent so that the functional layer side surface is on the inside.

In the laminate according to the present disclosure, the total light transmittance measured in accordance with JIS K7361-1 is preferably 85% or more, more preferably 88% or more, from the viewpoint of light transmittance. Further, it is preferably 90% or more.
The total light transmittance of the laminate of the present disclosure can be measured in the same manner as the total light transmittance of the polyimide film measured according to JIS K7361-1.

In the laminate of the present disclosure, the pencil hardness of the functional layer side surface is preferably H or higher, more preferably 2H or higher, and still more preferably 3H or higher.
The pencil hardness of the laminate of the present disclosure can be measured in the same manner except that the load is 9.8 N in the method for measuring the pencil hardness of the polyimide film.

In the laminated body of the present disclosure, the yellowness (YI value) calculated in accordance with JIS K7373-2006 is preferably 30 or less, more preferably 20 or less, from the viewpoint of light transmittance. More preferably, it is 15 or less, More preferably, it is 13 or less, It is especially preferable that it is 10 or less. Moreover, although not specifically limited, it is desirable that the yellowness (YI value) of the laminate of the present disclosure is 2.5 or less.
In addition, the laminated body of the present disclosure has a yellow color calculated in accordance with JIS K7373-2006 because yellowish coloring is suppressed, light transmittance is improved, and it can be suitably used as a glass substitute material. A value (YI value / film thickness (μm)) obtained by dividing the degree (YI value) by the film thickness (μm) is preferably 0.04 or less, and more preferably 0.03 or less.
The yellowness (YI value) of the laminate of the present disclosure can be measured in the same manner as the yellowness (YI value) calculated based on JIS K7373-2006 of the polyimide film.

The laminate of the present disclosure preferably has a haze value of 10 or less, more preferably 8 or less, and even more preferably 5 or less, from the viewpoint of light transmittance. Moreover, although it does not specifically limit, it is desirable that the haze value of the laminated body of this indication is 1.0 or less.
The haze value of the laminate of the present disclosure can be measured in the same manner as the haze value of the polyimide film.

The birefringence in the thickness direction of the laminate of the present disclosure at a wavelength of 590 nm is preferably 0.040 or less, more preferably 0.020 or less, from the viewpoint of reducing optical distortion, Or less, more preferably 0.010 or less, and even more preferably less than 0.008.
The birefringence of the laminate of the present disclosure can be measured in the same manner as the birefringence in the thickness direction at a wavelength of 590 nm of the polyimide film.

When the adhesion test is performed according to the following adhesion test method, the laminated body of the present disclosure does not cause peeling of the functional layer, which causes adhesion between the polyimide film and the functional layer and generation of interference fringes. It is preferable from the point of suppression, and the point of the bending tolerance and surface hardness of a laminated body.
[Adhesion test method]
The functional layer of the test piece of the laminate cut out to 10 cm × 10 cm was subjected to a cross-cut test in accordance with JIS K 5600-5-6, and after repeating the tape peeling operation 5 times, whether or not the functional layer was peeled off Observe.

6). Production method of laminate The production method of the laminate according to the present disclosure is not particularly limited as long as it is a method by which the laminate according to the present disclosure described above is obtained.
Preparing a polyimide film containing a polyimide having a structure represented by the general formula (1);
Forming a coating film of a functional layer composition containing at least one of a radical polymerizable compound and a cationic polymerizable compound on at least one surface of the polyimide film;
Curing the coating film of the functional layer composition,
At least one surface of the polyimide film has a functional layer containing at least one polymer of the radical polymerizable compound and the cationic polymerizable compound via a compatible layer, and the compatible layer is The manufacturing method of the laminated body containing the at least 1 sort (s) of component of the said polyimide film and the at least 1 sort (s) of the component of the said functional layer can be mentioned.
In addition, in the manufacturing method of the said laminated body, the said polyimide film can be prepared by the method similar to the manufacturing method of the polyimide film mentioned above. Moreover, the process of forming the coating film of the composition for functional layers, and the process of hardening the coating film of the composition for functional layers can be made into the method similar to the formation method of the functional layer mentioned above.

7). Use of laminated body The use of the laminated body of this indication is not specifically limited, For example, it can be used as members, such as a base material and surface material which glass products, such as thin plate glass, were conventionally used. The laminate of the present disclosure has improved bending resistance, excellent adhesion between the polyimide film and the functional layer, and has a good quality in which the generation of interference fringes is suppressed. Since it has hardness and light transmittance, it can be suitably used as a surface material for a display, in particular, it can be suitably used as a surface material for a flexible display, and can be used as a surface material for a foldable display. Can also be suitably used.
In addition, the laminated body of the present disclosure is specifically a flexible panel used for, for example, a thin and bent flexible organic EL display, a portable terminal such as a smartphone or a wristwatch type terminal, a display device inside a car, a wristwatch, or the like. It can use suitably for etc. In addition, the laminate of the present disclosure includes a member for an image display device such as a liquid crystal display device and an organic EL display device, a member for a touch panel, a flexible printed circuit board, a surface protection film, a member for solar cell panel such as a substrate material, and an optical waveguide. The present invention can also be applied to other members, other semiconductor-related members, and the like.

II. Surface material for display The surface material for display of this indication is a layered product of this indication mentioned above.
The display surface material of the present disclosure is used so as to be positioned on the surface of various displays. The display surface material of the present disclosure, like the laminate of the present disclosure described above, has improved bending resistance, excellent adhesion between the polyimide film and the functional layer, and good quality with suppressed generation of interference fringes. Since it has excellent surface hardness and light transmittance in a more preferred embodiment, it can be particularly suitably used for a flexible display.

The display surface material of the present disclosure can be used for various known displays and is not particularly limited. For example, the display surface material can be used for the display described in the application of the laminate of the present disclosure.

In the display surface material of the present disclosure, the outermost surface after being arranged on the display surface may be a polyimide film side surface or a functional layer side surface. Especially, it is preferable to arrange | position the surface material for a display of this indication so that the surface by the side of a functional layer may become a surface of the front side more. Further, the display surface material of the present disclosure may have a fingerprint adhesion preventing layer on the outermost surface.

Further, the method for disposing the display surface material of the present disclosure on the surface of the display is not particularly limited, and examples thereof include a method through an adhesive layer. As the adhesive layer, a conventionally known adhesive layer that can be used for adhesion of a display surface material can be used.

III. Touch panel member The touch panel member of the present disclosure includes the laminate of the present disclosure described above,
A transparent electrode having a plurality of conductive portions arranged on one surface side of the laminate;
A plurality of lead wires electrically connected to at least one side of the end portion of the conductive portion.

Since the touch panel member of the present disclosure includes the above-described laminate of the present disclosure, the touch panel member has excellent adhesion between the functional layer and the polyimide film, excellent bending resistance, and interference fringes are suppressed. Therefore, it can be particularly suitably used for a flexible display and has excellent optical characteristics.
It is preferable that the laminated body of this indication used for the touchscreen member of this indication has a functional layer on both surfaces of a polyimide film through a compatible layer.
In addition, the touch panel member of the present disclosure is not particularly limited, but it is preferable that the transparent electrode is laminated in contact with one surface side of the laminate.
The touch panel member of this indication can be arranged and used so that it may be located on the surface of various displays, for example. Moreover, the touch panel member of this indication and the laminated body of this indication as a surface material can also be arrange | positioned and used in this order on the surface of various displays.

12 is a schematic plan view of one surface of an example of the touch panel member of the present disclosure, FIG. 13 is a schematic plan view of the other surface of the touch panel member shown in FIG. 12, and FIG. FIG. 14 is a cross-sectional view taken along the line AA ′ of the touch panel member shown in FIG. 13. The touch panel member 20 shown in FIGS. 12, 13, and 14 includes the laminate 10 according to the present disclosure, the first transparent electrode 4 disposed in contact with one surface of the laminate 10, and the other of the laminate 10. And a second transparent electrode 5 disposed in contact with the surface. In the first transparent electrode 4, a plurality of first conductive portions 41, which are strip-like electrode pieces extending so as to extend in the x-axis direction, are arranged at a predetermined interval. A first lead wire 7 that is electrically connected to the first conductive portion 41 is connected to the first conductive portion 41 at either one of its longitudinal ends. A first terminal 71 for electrical connection with an external circuit may be provided at the end of the first lead-out line 7 extending to the end edge 21 of the laminate 10. The first conductive portion 41 and the first lead-out line 7 are generally connected in an inactive area 23 located outside the active area 22 that can be visually recognized by a touch panel user.
For the connection between the first conductive portion 41 and the first lead-out line 7, for example, as shown in FIG. 12, a connection structure in which a connection portion 24 is interposed can be adopted. Specifically, the connection portion 24 can be formed by extending a layer of a conductive material from a longitudinal end portion of the first conductive portion 41 to a predetermined position in the inactive area 23. Furthermore, a connection structure between the first conductive portion 41 and the first extraction line 7 can be formed by overlapping at least a part of the first extraction line 7 on the connection portion 24.
The connection between the first conductive portion 41 and the first lead-out line 7 is not limited to the structure forming the connection portion 24 as shown in FIG. For example, although not shown, the first conductive portion 41 is extended to the inactive area 23 in the longitudinal direction of the first conductive portion 41 and extended to the inactive area 23 in the inactive area 23. Both of them may be electrically connected by riding the first lead-out wire 7 on the end of the first lead wire 7.
In addition, in FIG. 12, although the form which connects either one of the longitudinal direction ends of the 1st electroconductive part 41 and the 1st extraction line 7 was shown, in this indication, one 1st electroconductivity is shown. It is good also as a form which electrically connects the 1st extraction line 7 to the both ends of the longitudinal direction of the part 41, respectively.

As shown in FIG. 13, the touch panel member 20 includes a second transparent electrode 5 disposed in contact with the other surface of the laminate 10. In the second transparent electrode 5, the second conductive portions 51, which are a plurality of strip-shaped electrode pieces extending so as to extend in the y-axis direction, are arranged at predetermined intervals in the x-axis direction. Yes.
A second lead wire 8 that is electrically connected to the second conductive portion 51 is connected to the second conductive portion 51 at one of its longitudinal ends.
The second lead-out line 8 is extended to a position that does not overlap the first terminal 71 in the end edge 21 where the first lead-out line 7 described above is extended among the end edges of the laminated body 10. .
A second terminal 81 for electrical connection with an external circuit is preferably provided at the end of the second lead-out line 8 extending to the end edge 21 of the laminate 10.
For the electrical connection between the second conductive portion 51 and the second lead-out line 8, the same form as the electrical connection between the first lead-out wire 7 and the first conductive portion 41 can be applied. .

12 and 13, the pattern in which the first extraction line 7 is a long wiring and the second extraction line 8 is a short wiring is only one embodiment of the touch panel member of the present disclosure. It is also possible to use a pattern in which the first extraction line 7 is a short wiring and the second extraction line 8 is a long wiring. Further, the extending direction of the first extraction line 7 and the extending direction of the second extraction line 8 are not limited to the directions shown in FIGS. 12 and 13 and can be arbitrarily designed.

The conductive part included in the touch panel member of the present disclosure can be appropriately selected and applied to those constituting the transparent electrode in the touch panel member, and the pattern of the conductive part is not limited to those shown in FIGS. 12 and 13. For example, a transparent electrode pattern capable of detecting a change in capacitance due to contact with a finger or the like or a state close to contact can be appropriately selected and applied by a capacitance method.
The material of the conductive portion is preferably a light transmissive material, for example, an indium oxide based transparent electrode material mainly composed of indium tin oxide (ITO), indium oxide, indium zinc oxide (IZO), or the like. , Tin oxide (SnO ₂ ), zinc oxide (ZnO), and the like, and the like, and conductive polymer compounds such as transparent conductive film, polyaniline, polyacetylene, and the like are not limited thereto. The first conductive portion 41 and the second conductive portion 51 may be formed using the same kind of conductive material, or may be formed using different materials. In particular, it is preferable to form the first conductive portion 41 and the second conductive portion 51 using the same type of conductive material from the viewpoint of more effectively suppressing the occurrence of warpage and distortion of the touch panel member.
The thickness of the conductive portion is not particularly limited, but when the conductive portion is formed by, for example, a photolithography technique, it can be generally formed to about 10 nm to 500 nm.

The conductive material constituting the lead-out line included in the touch panel member of the present disclosure may or may not be light transmissive. In general, the lead-out line can be formed using a metal material such as silver or copper having high conductivity. Specific examples include a metal simple substance, a metal composite, a metal / metal compound composite, and a metal alloy. Examples of the simple metal include silver, copper, gold, chromium, platinum, and aluminum. Examples of the metal composite include MAM (a three-layer structure of molybdenum, aluminum, and molybdenum). As a composite of a metal and a metal compound, a laminate of chromium oxide and chromium can be exemplified. As the metal alloy, a silver alloy or a copper alloy is generally used. Examples of the metal alloy include APC (silver, palladium and copper alloy). Further, in the lead-out line, a resin component may be appropriately mixed in the metal material described above.
In the touch panel member of the present disclosure, the terminal provided at the end of the lead-out line can be formed using the same material as the lead-out line, for example.
The thickness and width dimension of the extraction line are not particularly limited, but when the extraction line is formed by, for example, a photolithography technique, the thickness is generally about 10 nm to 1000 nm, and the width dimension is 5 μm to It is formed to about 200 μm. On the other hand, when the lead-out line is formed by printing such as screen printing, the thickness is generally formed to about 5 μm to 20 μm and the width dimension is formed to about 20 μm to 300 μm.

The touch panel member of the present disclosure is not limited to the form shown in FIGS. 12 to 14, and is configured, for example, by laminating a first transparent electrode and a second transparent electrode on separate laminates. It may be a thing.
FIG.15 and FIG.16 is a schematic plan view which shows an example of an electroconductive member provided with the laminated body of this indication, respectively. A first conductive member 201 illustrated in FIG. 15 includes the stacked body 10 of the present disclosure and the first transparent electrode 4 disposed in contact with one surface of the stacked body 10. The transparent electrode 4 has a plurality of first conductive portions 41. A second conductive member 202 illustrated in FIG. 16 includes the multilayer body 10 ′ of the present disclosure and the second transparent electrode 5 disposed in contact with one surface of the multilayer body 10 ′. The second transparent electrode 5 has a plurality of second conductive portions 51.
17 is a schematic cross-sectional view illustrating another example of the touch panel member of the present disclosure. The touch panel member 20 ′ illustrated in FIG. 17 includes the first conductive member 201 illustrated in FIG. 15 and the second conductive member illustrated in FIG. The conductive member 202 is provided. In the touch panel member 20 ′, the surface of the first conductive member 201 that does not have the first transparent electrode 4 and the surface of the second conductive member 202 that has the transparent electrode 5 are interposed via the adhesive layer 6. It is pasted together. In the present disclosure, for example, an adhesive layer for bonding the laminate of the present disclosure and the touch panel member of the present disclosure, an adhesive layer for bonding the touch panel members of the present disclosure, the touch panel member and the display device of the present disclosure. As the adhesive layer for adhering to the above, a conventionally known adhesive layer used for optical members can be appropriately selected and used. In the conductive member used in the touch panel member of the present disclosure, the configuration and materials of the transparent electrode, the lead-out line, and the terminal may be the same as the transparent electrode, the lead-out line, and the terminal used in the touch panel member of the present disclosure described above, respectively. it can.

IV. Liquid crystal display device The liquid crystal display device of the present disclosure includes the above-described stacked body of the present disclosure and a liquid crystal display unit that is disposed on one surface side of the stacked body and includes a liquid crystal layer between opposing substrates. .

Since the liquid crystal display device of the present disclosure includes the above-described laminate of the present disclosure, the liquid crystal display device has excellent adhesion between the functional layer and the polyimide film, excellent bending resistance, and interference fringes are suppressed. Therefore, it can be particularly suitably used for a flexible display and has excellent optical characteristics.
It is preferable that the laminated body of this indication used for the liquid crystal display device of this indication has a functional layer on both surfaces of a polyimide film through a compatible layer.
Further, the liquid crystal display device of the present disclosure may include the touch panel member of the present disclosure described above.
Further, the counter substrate included in the liquid crystal display device of the present disclosure may be provided with the stacked body of the present disclosure.

FIG. 18 is a schematic cross-sectional view illustrating an example of the liquid crystal display device of the present disclosure. The liquid crystal display device 100 illustrated in FIG. 18 includes the multilayer body 10 of the present disclosure and the first transparent electrode 4 on one surface of the multilayer body 10 ′ of the present disclosure, and the second transparent electrode 5 on the other surface. And a liquid crystal display unit 30. In the liquid crystal display device 100, the stacked body 10 is used as a surface material, and the stacked body 10 and the touch panel member 20 are bonded to each other through the adhesive layer 6.

The liquid crystal display unit used in the liquid crystal display device of the present disclosure has a liquid crystal layer formed between substrates disposed to face each other, and may adopt a configuration used in a conventionally known liquid crystal display device. it can.
A driving method of the liquid crystal display device of the present disclosure is not particularly limited, and a driving method generally used for a liquid crystal display device can be adopted, for example, a TN method, an IPS method, an OCB method, and an MVA method. Etc.
The counter substrate used in the liquid crystal display device of the present disclosure can be appropriately selected and used depending on the driving method of the liquid crystal display device, and a substrate provided with the stacked body of the present disclosure may be used.
As the liquid crystal constituting the liquid crystal layer, various liquid crystals having different dielectric anisotropy and mixtures thereof can be used according to the driving method of the liquid crystal display device of the present disclosure.
As a method for forming the liquid crystal layer, a method generally used as a method for manufacturing a liquid crystal cell can be used, and examples thereof include a vacuum injection method and a liquid crystal dropping method. After forming the liquid crystal layer by the above-described method, the sealed liquid crystal can be aligned by slowly cooling the liquid crystal cell to room temperature.
In the liquid crystal display device according to the present disclosure, a plurality of colored layers and a light-shielding portion for defining pixels may be further provided between the substrates arranged opposite to each other. In addition, the liquid crystal display unit may include a backlight unit including a light emitting element and a phosphor at a position opposite to the side where the touch panel member is positioned outside the substrate disposed oppositely. Moreover, you may have a polarizing plate in the outer surface of the board | substrate opposingly arranged, respectively.

FIG. 19 is a schematic cross-sectional view showing another example of the liquid crystal display device of the present disclosure. A liquid crystal display device 200 illustrated in FIG. 19 includes a laminate 10 according to the present disclosure, a first conductive member 201 including the first transparent electrode 4 on one surface of the laminate 10 ′ according to the present disclosure, The touch panel member 20 ′ having the second conductive member 202 including the second transparent electrode 5 on one surface of the stacked body 10 ″ and the liquid crystal display unit 30. In the liquid crystal display device 200, the stacked body 10. And the first conductive member 201, and the first conductive member 201 and the second conductive member 202 are bonded to each other via the adhesive layer 6. The configuration of the touch panel member 20 ′ is, for example, 17 can be the same as the configuration of the touch panel member 20 'shown in Fig. 17. The conductive member used for the liquid crystal display device of the present disclosure is the same as the conductive member used for the touch panel member of the present disclosure. To use Can.

V. Organic electroluminescence display device The organic electroluminescence display device of the present disclosure includes the above-described laminate of the present disclosure and an organic electroluminescence layer disposed between the opposing substrates disposed on one surface side of the laminate. An organic electroluminescence display portion.

Since the organic electroluminescence display device of the present disclosure is provided with the laminate of the present disclosure described above, the adhesion between the functional layer and the polyimide film is excellent, the bending resistance is excellent, and the generation of interference fringes is suppressed. Therefore, it can be used particularly suitably for flexible displays and has excellent optical properties.
It is preferable that the laminated body of this indication used for the organic electroluminescent display apparatus of this indication has a functional layer on both surfaces of a polyimide film through a compatible layer.
Moreover, the organic electroluminescence display device of the present disclosure may include the touch panel member of the present disclosure described above.
In addition, the counter substrate included in the organic electroluminescence display device of the present disclosure may include the stacked body of the present disclosure.

FIG. 20 is a schematic cross-sectional view illustrating an example of the organic electroluminescence display device of the present disclosure. An organic electroluminescence display device 300 shown in FIG. 20 includes the laminate 10 of the present disclosure and the first transparent electrode 4 on one surface of the laminate 10 ′ of the present disclosure, and the second transparent on the other surface. A touch panel member 20 including the electrodes 5 and an organic electroluminescence display unit 40 are included. In the organic electroluminescence display device 300, the stacked body 10 is used as a surface material, and the stacked body 10 and the touch panel member 20 are bonded to each other through the adhesive layer 6.

An organic electroluminescence display unit (organic EL display unit) used in the organic electroluminescence display device (organic EL display device) of the present disclosure is an organic electroluminescence layer (organic EL layer) formed between substrates disposed to face each other. The structure used for a conventionally known organic EL display device can be employed.
The organic EL display unit further includes a support substrate, an organic EL element including an organic EL layer and an anode layer and a cathode layer that sandwich the organic EL layer, and a sealing substrate that seals the organic EL element. It may be. The organic EL layer only needs to have at least an organic EL light-emitting layer. For example, from the anode layer side, a hole injection layer, a hole transport layer, an organic EL light-emitting layer, an electron transport layer, and an electron injection What has the structure which the layer laminated | stacked in this order can be used.
The organic EL display device of the present disclosure is applicable to, for example, a passive drive type organic EL display and an active drive type organic EL display. The counter substrate used in the organic EL display device of the present disclosure can be appropriately selected and used according to the driving method of the organic EL display device, and a substrate provided with the stacked body of the present disclosure may be used.

FIG. 21 is a schematic cross-sectional view showing another example of the organic electroluminescence display device of the present disclosure. An organic electroluminescence display device 400 shown in FIG. 21 includes a laminate 10 of the present disclosure, a first conductive member 201 including the first transparent electrode 4 on one surface of the laminate 10 ′ of the present disclosure, It has the touch panel member 20 'which has the 2nd electroconductive member 202 provided with the 2nd transparent electrode 5 in one surface of the laminated body 10 "of an indication, and the organic electroluminescent display part 40. Organic electroluminescent display apparatus In 400, the laminated body 10 and the first conductive member 201, and the first conductive member 201 and the second conductive member 202 are bonded together via the adhesive layer 6. The touch panel member 20 ′. The configuration of can be the same as the configuration of the touch panel member 20 'shown in Fig. 17. The configuration of the organic electroluminescence display device of the present disclosure can be used. The that the conductive member may be the same as the conductive member for use in a touch panel member of the present disclosure.

Hereinafter, when there was no notice in particular, it measured or evaluated at 25 degreeC.
[Evaluation methods]
<Weight average molecular weight of polyimide precursor>
The weight average molecular weight of the polyimide precursor was developed by making the polyimide precursor a 0.5% by weight N-methylpyrrolidone (NMP) solution, filtering the solution through a syringe filter (pore diameter: 0.45 μm), and developing the polyimide precursor. As a solvent, a 10 mmol% LiBr-NMP solution having a water content of 500 ppm or less was used, a GPC apparatus (manufactured by Tosoh Corporation, HLC-8120, column used: GPC LF-804 made by SHODEX), a sample injection amount of 50 μL, and a solvent flow rate of 0.5 mL. The measurement was performed under the conditions of 40 ° C./min. The weight average molecular weight of the polyimide precursor is a polystyrene standard sample having the same concentration as the sample (weight average molecular weight: 364,700, 204,000, 103,500, 44,360,27,500, 13,030, 6,300, 3,070) was used as a conversion value with respect to standard polystyrene measured. The elution time was compared with a calibration curve to determine the weight average molecular weight.
<Viscosity of polyimide precursor solution>
The viscosity of the polyimide precursor solution was measured using a viscometer (for example, TVE-22HT, Toki Sangyo Co., Ltd.) at 25 ° C. and a sample amount of 0.8 ml.

<Weight average molecular weight of polyimide>
15 mg of polyimide powder is immersed in 15000 mg of N-methylpyrrolidone (NMP), and heated at 60 ° C. in a water bath, with a stirrer at a rotation speed of 200 rpm, and stirred for 3 to 60 hours until dissolution is visually confirmed. As a result, an NMP solution having a concentration of 0.1% by weight was obtained. The solution was filtered through a syringe filter (pore size: 0.45 μm), a 30 mmol% LiBr-NMP solution having a water content of 500 ppm or less was used as a developing solvent, and a GPC apparatus (manufactured by Tosoh Corporation, HLC-8120, detector: differential) Refractive index (RID) detector, column used: two SHODEX GPC LF-804s connected in series), sample injection amount 50 μL, solvent flow rate 0.4 mL / min, column temperature 37 ° C., detector temperature 37 ° C. The measurement was performed under the following conditions. The weight average molecular weight of the polyimide is the same as the polystyrene standard sample (weight average molecular weight: 364,700, 204,000, 103,500, 44,360,27,500, 13,030, 6,300, 3, 070) was used as a conversion value with respect to standard polystyrene measured. The elution time was compared with a calibration curve to determine the weight average molecular weight.

<Viscosity of polyimide solution>
The viscosity of the polyimide solution was measured using a viscometer (eg, TVE-22HT, Toki Sangyo Co., Ltd.) at 25 ° C. and a sample amount of 0.8 ml.

<Thickness measurement method>
The film thickness of a total of five points at the four corners and the center of a polyimide film or laminate test piece cut into a size of 10 cm × 10 cm was measured using a digital linear gauge (manufactured by Ozaki Mfg. Co., Ltd., model PDN12 digital gauge). The average of the measured values was taken as the film thickness of the polyimide film or laminate.

<Dyeing of compatible layer>
A sample of a laminate cut into 2 mm × 10 mm strips was fixed by embedding and fixing with an epoxy resin, and then 50 nm using a microtome (Leica, LEICA EM UC7) in the thickness direction of the fixed sample. The ultra-thin sections prepared by cutting with a width of about 150 nm were sealed in a 30 mL capacity weighing bottle together with ruthenium tetroxide (manufactured by Rare Metallic), and left at room temperature (25 ° C.) for 30 minutes. Thereafter, the lid of the weighing bottle was opened and left for 15 minutes, and then the cross section in the thickness direction of the sample contained in the ultrathin slice was observed with STEM.
On the other hand, the cross section in the thickness direction of the sample included in the ultrathin slice before staining with ruthenium tetroxide was also observed with STEM.
In each example and each comparative example, by comparing STEM photographs before and after dyeing with ruthenium tetroxide, the dyed compatible layer was confirmed, the thickness was measured, and evaluated according to the following evaluation criteria. In Comparative Example 3, the interface of the dyed compatible layer was unclear, and the thickness could not be measured.
(Evaluation criteria)
A: The thickness of the dyed compatible layer was 5 nm or more at an arbitrary position.
B: Between the polyimide film and the functional layer, there was a portion where the dyed compatible layer could not be observed, and the dyed compatible layer was a sea-island shape.

The STEM image after dyeing the cross section in the thickness direction of the laminate obtained in Example 1 with ruthenium tetroxide is shown in FIG. 3, and the STEM image before dyeing is shown in FIG.
FIG. 5 shows a STEM image after staining the cross section in the thickness direction of the laminate obtained in Example 2 with ruthenium tetroxide, and FIG. 6 shows a STEM image before dyeing.
The STEM image after dyeing the cross section of the thickness direction of the laminated body obtained in Example 3 with ruthenium tetroxide is shown in FIG.
STEM image after dyeing of the laminate of Example 1 shown in FIG. 3, STEM image after dyeing of the laminate of Example 2 shown in FIG. 5, STEM image after dyeing of the laminate of Example 3 shown in FIG. From the above, it was observed that each laminate had the functional layer 3 on one surface of the polyimide film 1 through the compatible layer 2 dyed with ruthenium tetroxide.
FIG. 8 shows a STEM image of the cross section in the thickness direction of the laminate obtained in Comparative Example 2 after dyeing with ruthenium tetroxide, and FIG. 9 shows a STEM image before dyeing. From the STEM image after dyeing | staining of the laminated body of the comparative example 2 shown in FIG. 8, between the polyimide film 1 and the functional layer 3, there was a location which cannot observe the compatible layer 2 dye | stained with the ruthenium tetroxide.
FIGS. 10 and 11 show STEM images after the cross section in the thickness direction of the laminate obtained in Comparative Example 3 is dyed with ruthenium tetroxide. The STEM image shown in FIG. 10 and the STEM image shown in FIG. 11 have different magnifications at the time of photographing. From the STEM image after dyeing of the laminate of Comparative Example 3 shown in FIGS. 10 and 11, the interface between the polyimide film and the functional layer is unclear, and the compatible layer dyed with ruthenium tetroxide is observed. I could not.

<Adhesion evaluation>
The functional layer of the test piece of the laminate cut out to 10 cm × 10 cm was subjected to a cross-cut test in accordance with JIS K 5600-5-6, and after repeating the tape peeling operation 5 times, whether or not the functional layer was peeled off Was observed and the adhesion was evaluated according to the following evaluation criteria.
(Evaluation criteria)
A: No peeling of the functional layer occurred even after repeating the peeling operation with the tape 5 times.
B: The peeling of the functional layer did not occur after the tape peeling operation was performed once, but the functional layer was peeled until the tape peeling operation was repeated 5 times.
C: After performing the peeling operation with the tape once, the functional layer was peeled entirely along the edge of the cut.

<Evaluation of interference fringes>
Using an interference fringe inspection lamp (Na lamp) manufactured by Funatech, the presence or absence of interference fringes in the laminate was visually inspected and evaluated according to the following evaluation criteria. The polyimide film side surface of the laminate was painted with black ink, and an interference fringe inspection lamp was applied to the functional layer side surface for evaluation by reflection observation.
(Evaluation criteria)
A: Generation of interference fringes was not observed.
B: A thin interference fringe was observed.
C: Interference fringes were clearly observed.

<Pencil hardness>
Pencil hardness was measured about the polyimide film used for preparation of a laminated body, and the functional layer side surface of a laminated body.
The pencil hardness of the polyimide film is determined by conditioning the sample for 2 hours at a temperature of 25 ° C. and a relative humidity of 60%, and then using a test pencil specified by JIS-S-6006 and making a pencil scratch by Toyo Seiki Co., Ltd. By performing a pencil hardness test (0.98N load) specified in JIS K5600-5-4 (1999) on the surface of the sample using a coating film hardness tester and evaluating the highest pencil hardness without scratches went.
The pencil hardness of the laminate was evaluated in the same manner except that the load was changed to 9.8 N in the method for measuring the pencil hardness of the polyimide film.

<Static bending test>
A static bending test was performed on the polyimide film used for manufacturing the laminate and the laminate.
Hereinafter, the method of the static bending test will be described with reference to FIG.
A test piece 11 of a polyimide film or laminate cut out to 15 mm × 40 mm is bent at a half of the long side, and both ends of the long side of the test piece 11 are 6 mm thick metal pieces 12 (100 mm × 30 mm × 6 mm) on top. They were placed so as to be sandwiched from the lower surface, and fixed with tape so that the overlap between the upper and lower surfaces of both ends of the test piece 11 and the metal piece 12 was 10 mm each. The metal piece 12 on which the test piece 11 was fixed was sandwiched between glass plates (100 mm × 100 mm × 0.7 mm) 13a and 13b from above and below, and the test piece 11 was fixed in a bent state with an inner diameter of 6 mm. At that time,

dummy test pieces

14a and 14b were sandwiched between portions of the metal piece 12 where the test piece 11 was not provided, and fixed with tape so that the

glass plates

13a and 13b were parallel.
The test piece fixed in the bent state in this way was allowed to stand for 24 hours in an environment of 60 ° C. and 90% relative humidity (RH), and then the glass plate and the test piece fixing tape were removed, and the test piece 11 was removed. Release the power of the. Thereafter, one end of the test piece 11 was fixed, and the internal angle of the test piece 11 was measured 30 minutes after releasing the force applied to the test piece 11.
The laminate was bent so that the functional layer side surface was on the inside. When the specimen is completely restored without being affected by the static bending test, the inner angle is 180 °.

<Birefractive index>
The thickness direction retardation value (Rth) of the polyimide film was measured with a light of 25 ° C. and a wavelength of 590 nm using a phase difference measuring apparatus (product name “KOBRA-WR” manufactured by Oji Scientific Instruments). For the thickness direction retardation value (Rth), a phase difference value at 0 ° incidence and a phase difference value at an incidence angle of 40 ° were measured, and a thickness direction retardation value Rth was calculated from these retardation values. The retardation value at an oblique incidence of 40 degrees was measured by allowing light having a wavelength of 590 nm to enter the film from a direction inclined by 40 degrees from the normal line of the film.
The birefringence of the polyimide film was determined by substituting it into the formula: Rth / d (polyimide film thickness (nm)).

<Total light transmittance>
The total light transmittance was measured with a haze meter (HM150, manufactured by Murakami Color Research Laboratory) in accordance with JIS K7361-1.

<YI value (yellowness)>
The YI value is determined according to JIS K7373-2006 using an ultraviolet-visible near-infrared spectrophotometer (JASCO Corporation V-7100), by spectrocolorimetric method, using auxiliary illuminant C, and 2 degree field of view. The tristimulus values X, Y, Z in the XYZ color system are obtained based on the transmittance measured in the range of 250 nm to 800 nm at 1 nm intervals, and the following formula is obtained from the X, Y, Z values. Calculated.
YI = 100 (1.2769X−1.0592Z) / Y

<Haze value>
The haze value was measured with a haze meter (HM150, manufactured by Murakami Color Research Laboratory) in accordance with JIS K-7105.

(Synthesis Example 1)
In a 5 L separable flask, a solution of 3327.9 g of dehydrated dimethylacetamide and 59.7 g (240.2 mmol) of 1,3-bis (3-aminopropyl) tetramethyldisiloxane (AprTMOS) was dissolved. To the place where the liquid temperature was controlled to 30 ° C., 53.3 g (120.1 mmol) of 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) was gradually added so that the temperature rise was 2 ° C. or less. And stirred with a mechanical stirrer for 4 hours. To this, 472.4 g (1475.3 mmol) of 2,2′-bis (trifluoromethyl) benzidine (TFMB) was added, and after confirming complete dissolution, 4,4 ′-(hexafluoroisopropylidene) 663.0 g (1492.5 mmol) of diphthalic anhydride (6FDA) was gradually added in several times so that the temperature rise was 2 ° C. or less, and polyimide precursor solution 1 (solid) in which polyimide precursor 1 was dissolved 20% by weight) was synthesized. The molar ratio of TFMB used for the polyimide precursor 1 to AprTMOS was 86:14. Table 1 shows the viscosity at 25 ° C. of the polyimide precursor solution 1 (solid content 20% by weight) and the weight average molecular weight of the polyimide precursor 1 measured by GPC.

(Synthesis Examples 2 to 5, Comparative Synthesis Example 2)
The reaction was carried out by the procedure of Synthesis Example 1 so that the raw material and solid content concentrations shown in Table 1 were obtained, to obtain polyimide precursor solutions 2 to 5 and comparative polyimide precursor solution 2.

(Comparative Synthesis Example 1)
A solution in which 169.5 g of dehydrated dimethylacetamide and 32.0 g (100 mmol) of 2,2′-bis (trifluoromethyl) benzidine (TFMB) were dissolved in a 500 ml separable flask at a liquid temperature of 30 ° C. To the controlled part, 44.2 g (99.5 mmol) of 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) was gradually divided into several times so that the temperature rise was 2 ° C. or less. The comparative polyimide precursor solution 1 (solid content 25% by weight) in which the comparative polyimide precursor 1 was dissolved was synthesized. Table 1 shows the viscosity of the comparative polyimide precursor solution 1 at 25 ° C. and the weight average molecular weight of the comparative polyimide precursor 1 measured by GPC.

(Comparative Synthesis Example 3)
In a 500 ml separable flask, a solution in which 345.3 g of dehydrated dimethylacetamide and 49.7 g (200 mmol) of 1,3-bis (3-aminopropyl) tetramethyldisiloxane (AprTMOS) were dissolved was liquid. To the place where the temperature was controlled to 30 ° C., 88.4 g (199 mmol) of 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) was gradually added so that the temperature rise was 2 ° C. or less. A comparative polyimide precursor solution 3 (solid content 40 wt%) in which the comparative polyimide precursor 3 was dissolved was synthesized. Table 1 shows the viscosity at 25 ° C. of the comparative polyimide precursor solution 3 (solid content 40% by weight) and the weight average molecular weight of the comparative polyimide precursor 3 measured by GPC.

In the following, the abbreviations in the table are as follows.
TFMB: 2,2′-bis (trifluoromethyl) benzidine AprTMOS: 1,3-bis (3-aminopropyl) tetramethyldisiloxane 6FDA: 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride

(Examples 1 to 5, Comparative Examples 1 to 3)
1. Preparation of Polyimide Film Using the polyimide precursor solutions 1 to 5 and the comparative polyimide precursor solutions 1 to 3, the following steps (1) to (3) were performed to prepare polyimide films having a thickness of about 50 μm.
(1) Each polyimide precursor solution was apply | coated on the glass plate, and it dried for 10 minutes with 120 degreeC circulation oven.
(2) Under a nitrogen stream (oxygen concentration of 100 ppm or less), the temperature was raised to 350 ° C. at a rate of temperature rise of 10 ° C./min, held for 1 hour, and then cooled to room temperature.
(3) It peeled from the glass plate and obtained each polyimide film.

2. Formation of functional layer and compatible layer On one surface of the obtained polyimide film, the functional layer composition 1 having the following composition was applied so that the thickness after curing of the functional layer 1 would be 7 μm, and at 70 ° C. The solvent in the coating film is evaporated by heating for 1 minute, and using an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb), the total amount of light in the air is 100 mJ / cm ^2. The film was half cured by irradiation to form a semi-cured film of the functional layer composition 1. Next, the functional layer composition 2 having the following composition is applied to the surface of the semi-cured film so that the thickness after curing of the functional layer 2 is 3 μm, and heated at 70 ° C. for 1 minute in the coating film. The solvent was evaporated, and ultraviolet rays were irradiated using an ultraviolet ray irradiation device (light source H bulb, manufactured by Fusion UV System Japan Co., Ltd.) so that the integrated light amount was 200 mJ / cm ² under an oxygen concentration of 200 ppm or less. By completely curing the coating film, a functional layer 1 having a thickness of 7 μm and a functional layer 2 having a thickness of 3 μm were formed in this order on the polyimide film, and a laminate having an overall thickness of about 60 μm was produced. . Table 2 shows the film thickness of each laminate.
<Composition of functional layer composition 1>
-25 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (M403, manufactured by Toa Gosei Co., Ltd.)-25 parts by mass of dipentaerythritol EO-modified hexaacrylate (A-DPH-6E, manufactured by Shin-Nakamura Chemical Co., Ltd.) Atypical silica fine particles (average particle size 25 nm, manufactured by JGC Catalysts & Chemicals Co., Ltd.)
Photopolymerization initiator (Irgacure 184, manufactured by BASF) 4 parts by mass Fluorine leveling agent (F568, manufactured by DIC) 0.2 parts by weight (in terms of solid content)
-Solvent (methyl isobutyl ketone (MIBK)) 150 parts by mass <Composition of composition 2 for functional layer>
・ Urethane acrylate (UX5000, manufactured by Nippon Kayaku Co., Ltd.) 25 mass parts ・ Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (M403, manufactured by Toa Gosei Co., Ltd.) 50 mass parts ・ Polyfunctional acrylate polymer (Acryt 8KX-012C) , Manufactured by Taisei Fine Chemical Co., Ltd.) 25 parts by mass (in terms of solid content)
-Antifouling agent (BYKUV3500, manufactured by Big Chemie) 1.5 parts by mass (in terms of solid content)
Photopolymerization initiator (Irgacure 184, manufactured by BASF) 4 parts by mass Solvent (methyl isobutyl ketone (MIBK)) 150 parts by mass

Moreover, the Martens hardness of the surface of the functional layer side of the obtained laminate was measured by a nanoindentation method. Specifically, using “TI950 TriboIndenter” manufactured by HYSITRON, Berkovich indenter (triangular pyramid) is pushed into the surface of the functional layer 2 of the laminated body by 500 nm, and the residual stress is alleviated by holding it constant. Then, unloading is performed, and the maximum load after relaxation is measured. Using the maximum load (P _max (μN)) and the indentation area (A (nm ² ) having a depth of 500 nm, P _max / From A, Martens hardness was calculated. The Martens hardness of the surface on the functional layer side of the obtained laminate was 500 MPa.

From Table 2, the laminated bodies of Examples 1 to 5 corresponding to the laminated body of the present disclosure have improved static bending resistance and functional layer adhesion, suppressed generation of interference fringes, and further improved surface hardness. It was shown that. Further, from Table 2, it was shown that the laminates of Examples 1 to 5 corresponding to the laminate of the present disclosure are excellent in optical properties with high transparency.
On the other hand, the laminates of Comparative Examples 1 and 2 were inferior in adhesion of the functional layer, interference fringes were observed, and static bending resistance was also inferior. The laminate of Comparative Example 3 was greatly inferior in static bending resistance and inferior in surface hardness.

(Example 6)
1. Preparation of polyimide film (1) Preparation of polyimide (chemical imidization)
In the same manner as in Synthesis Example 1, a polyimide precursor solution 1 (solid content 20% by weight) in which the polyimide precursor 1 was dissolved was synthesized.
The polyimide precursor solution 500 g was lowered to room temperature, pyridine (42.0 g, 531 mmol) as a catalyst and acetic anhydride (54.2 g, 531 mol) were added, and the mixture was stirred at room temperature for 24 hours to synthesize a polyimide solution. The obtained polyimide solution (596.2 g) was transferred to a 5 L separable flask, and butyl acetate (403.8 g) was added and stirred until uniform. Next, methanol (3000 g) was gradually added to obtain a white slurry. The slurry was filtered and washed 5 times with methanol to obtain polyimide 6 (100 g). The weight average molecular weight of the polyimide measured by GPC was 114322.
(2) Manufacture of a polyimide film The powder of the polyimide 6 was dissolved in the solvent (dichloromethane), and the polyimide solution 6 with a solid content of 17 mass% was produced. The viscosity of the polyimide solution 6 (solid content: 17% by mass) at 25 ° C. was 4801 cps.
Using the polyimide solution 6 obtained as described above, a polyimide film having a thickness of about 50 μm was prepared by performing the following procedures (i) to (iii).
(I) The polyimide solution 6 was apply | coated on the glass plate, the film was peeled from the glass plate after natural drying.
(Ii) The film was dried in a circulation oven at 50 ° C. for 10 minutes.
(Iii) The film was heated to 200 ° C. under a nitrogen stream (oxygen concentration of 100 ppm or less) at a heating rate of 10 ° C./min, held at 200 ° C. for 1 hour, and then cooled to room temperature to obtain a polyimide film. .

2. Formation of functional layer and compatible layer In the same manner as in Example 1, a functional layer 1 having a thickness of 7 μm and a functional layer 2 having a thickness of 3 μm were formed in this order on one surface of the obtained polyimide film. A laminate having an overall thickness of about 60 μm was produced. Table 4 shows the thickness of the laminate.

(Examples 7 to 10)
1. Preparation of polyimide film (1) Preparation of polyimide (chemical imidization)
In the procedure for synthesizing the polyimide of Example 6, polyimide precursor solutions 2 to 5 obtained in the same manner as Synthesis Examples 2 to 5 were used in place of the polyimide precursor solution 1 obtained in Synthesis Example 1, respectively. Except that, polyimides 7 to 10 were obtained by the same reaction.
(2) Manufacture of polyimide film In Example 6, in place of polyimide 6, polyimides 7 to 10 were used, except that the solid content concentration shown in Table 3 was adjusted. The polyimide solutions 7 to 10 shown in 3 were obtained.
In Example 6, polyimide films of Examples 7 to 10 were obtained in the same manner as Example 6 except that polyimide solutions 7 to 10 were used instead of polyimide solution 6.

2. Formation of functional layer and compatible layer In the same manner as in Example 1, a functional layer 1 having a thickness of 7 μm and a functional layer 2 having a thickness of 3 μm were formed in this order on one surface of the obtained polyimide film. A laminate having an overall thickness of about 60 μm was produced. Table 4 shows the film thickness of each laminate.

From Table 4, the laminated bodies of Examples 6 to 10 corresponding to the laminated body of the present disclosure have improved static bending resistance and functional layer adhesion, suppressed generation of interference fringes, and further improved surface hardness. It was shown that. Further, from Table 4, it was shown that the laminates of Examples 6 to 10 corresponding to the laminate of the present disclosure were particularly excellent in optical properties with high yellowness, in which yellowing was suppressed. . Further, each of the laminates of Examples 6 to 10 showed a tendency that the compatible layer was thicker and the adhesion was improved as compared with the laminates of Examples 1 to 5 having the same Si-containing diamine ratio.

DESCRIPTION OF SYMBOLS 1 Polyimide film 2 Compatibility layer 3

Functional layer

10, 10 ', 10 "Laminated body 11 Test piece 12

Metal piece

13a,

13b Glass plate

14a, 14b Dummy test piece 4 1st transparent electrode 41 1st electroconductive part 5 Second transparent electrode 51 Second conductive portion 6 Adhesive layer 7 First lead wire 71 First terminal 8 Second lead wire 81 Second terminal 20, 20 'Touch panel member 21 Edge of laminate 22 Active Area 23 Inactive area 24 Connection unit 201 First conductive member 202 Second conductive member 30 Liquid crystal display unit 40 Organic

electroluminescence display unit

100, 200 Liquid crystal display device 300, 400 Organic electroluminescence display device

Claims

At least one surface of the polyimide film has a functional layer containing at least one polymer of a radical polymerizable compound and a cationic polymerizable compound via a compatible layer,
The compatible layer contains at least one component of the constituent components of the polyimide film and at least one component of the constituent components of the functional layer,
The laminated body in which the said polyimide film contains the polyimide which has a structure represented by following General formula (1).

(In the general formula (1), R 1 represents a tetravalent group which is a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, R 2 represents a divalent group which is a diamine residue, 10 mol% or more and 90 mol% or less of the total amount of R 2 is a diamine residue having a silicon atom in the main chain, and 10 mol% or more and 90 mol% or less does not have a silicon atom, and is an aromatic ring or a fatty acid. (A diamine residue having a group ring. N represents the number of repeating units.)
In the polyimide having the structure represented by the general formula (1), the diamine residue having a silicon atom in the main chain in R 2 in the general formula (1) has one silicon atom in the main chain or The laminate according to claim 1, which is a diamine residue having two.
The thickness of the compatible layer dyed in the cross section in the thickness direction of the laminate dyed with at least one selected from the group consisting of ruthenium tetroxide, osmium tetroxide and tungsten phosphate is 5 nm or more. The laminate according to 1 or 2.
The laminate according to any one of claims 1 to 3, wherein when a static bending test is performed according to the following static bending test method, an internal angle measured in the test is 120 ° or more.
[Static bending test method]
The laminate test piece cut out to 15 mm × 40 mm is bent at a half of the long side, and both ends of the long side of the test piece sandwich a metal piece (100 mm × 30 mm × 6 mm) having a thickness of 6 mm from the upper and lower surfaces. Placed between glass plates (100 mm x 100 mm x 0.7 mm) from above and below with the tape fixed so that the overlap between the top and bottom surfaces of the test piece and the metal piece is 10 mm each. The test piece is fixed in a bent state with an inner diameter of 6 mm. At that time, a dummy test piece is sandwiched between the metal piece and the glass plate where there is no test piece, and is fixed with tape so that the glass plate is parallel. The test piece thus fixed in a bent state is left to stand for 24 hours in an environment of 60 ° C. and 90% relative humidity (RH), and then the glass plate and fixing tape are removed, and the test piece is attached to the test piece. Release this force. Thereafter, one end of the test piece is fixed, and the internal angle of the test piece 30 minutes after the force applied to the test piece is released is measured.
The total light transmittance measured in accordance with JIS K7361-1 is 85% or more,
The laminate according to any one of claims 1 to 4, wherein the yellowness calculated in accordance with JIS K7373-2006 is 30 or less.
The laminate according to claim 5, wherein a value obtained by dividing the yellowness calculated in accordance with JIS K7373-2006 by the film thickness (μm) is 0.04 or less.
The polyimide having the structure represented by the general formula (1) contains an aromatic ring, and (i) a fluorine atom, (ii) an aliphatic ring, and (iii) an aromatic ring is a sulfonyl group or fluorine. The laminate according to any one of claims 1 to 6, comprising at least one selected from the group consisting of a structure linked by an alkylene group which may be substituted with.
In the polyimide having the structure represented by the general formula (1), R 1 in the general formula (1) is a cyclohexanetetracarboxylic dianhydride residue, a cyclopentanetetracarboxylic dianhydride residue, a di Cyclohexane-3,4,3 ′, 4′-tetracarboxylic dianhydride residue, cyclobutanetetracarboxylic dianhydride residue, pyromellitic dianhydride residue, 3,3 ′, 4,4′- Biphenyltetracarboxylic dianhydride residue, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride residue, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride residue, 3, 4 ′-(hexafluoroisopropylidene) diphthalic anhydride residue, 3,3 ′-(hexafluoroisopropylidene) diphthalic anhydride residue, 4,4′-oxydiphthalic anhydride residue, and 3, '- is at least one tetravalent group selected from the group consisting of oxydiphthalic anhydride residue, laminate according to any one of claims 1 to 7.
In the polyimide having the structure represented by the general formula (1), the diamine residue having the aromatic ring or the aliphatic ring in R 2 in the general formula (1) is a 1,4-cyclohexanediamine residue. Group, trans-1,4-bismethylenecyclohexanediamine residue, 4,4′-diaminodiphenylsulfone residue, 3,4′-diaminodiphenylsulfone residue, 2,2-bis (4-aminophenyl) propane residue The laminate according to any one of claims 1 to 8, which is at least one divalent group selected from the group consisting of a group and a divalent group represented by the following general formula (2).

(In General Formula (2), R 3 and R 4 each independently represents a hydrogen atom, an alkyl group, or a perfluoroalkyl group.)
The laminate according to any one of claims 1 to 9, wherein the functional layer contains a polymer of a polyfunctional (meth) acrylate monomer.
The laminate according to any one of Claims 1 to 10, wherein the Martens hardness of the surface of the functional layer on the side opposite to the side on which the polyimide film is located is 350 MPa or more and less than 1000 MPa.
A display surface material, which is the laminate according to any one of claims 1 to 11.
The display surface material according to claim 12, which is used for a flexible display.
The laminate according to any one of claims 1 to 11,
A transparent electrode having a plurality of conductive portions arranged on one surface side of the laminate;
A touch panel member comprising: a plurality of lead wires that are electrically connected on at least one side of an end portion of the conductive portion.
The laminate according to any one of claims 1 to 11,
A liquid crystal display unit having a liquid crystal layer disposed between opposing substrates, disposed on one surface side of the laminate;
A liquid crystal display device.
The laminate according to any one of claims 1 to 11,
An organic electroluminescence display unit having an organic electroluminescence layer disposed between opposing substrates, disposed on one surface side of the laminate,
An organic electroluminescence display device.