JP7223902B1 - LAMINATED BODY, RESIN COMPOSITION, AND DISPLAY DEVICE - Google Patents

Abstract

The present invention provides a laminate including a glass layer and a resin layer, which has high adhesion between the glass layer and the resin layer, and is useful as a window film of a display device. [Solution] A laminate including an inorganic glass (A) and a resin layer (B) directly laminated on at least one surface of the inorganic glass (A), wherein the resin layer (B) is made of polyimide. at least one resin selected from the group consisting of polyamide-based resins and polyamide-based resins, a filler having an average primary particle size of 1 to 50 nm, and selected from the group consisting of isocyanate groups, blocked isocyanate groups, epoxy groups, glycidyl groups, and oxetanyl groups. A laminate formed from a resin composition containing a silane coupling agent having at least one type of group. [Selection diagram] None

Description

TECHNICAL FIELD The present invention relates to a laminate and a resin composition useful as a window film for a display device.

Glass substrates, also called inorganic glass, are used in various devices such as electronic displays. Since the glass substrate is hard and easily broken, a resin film is laminated on the glass substrate to provide the glass substrate with impact resistance and a function of preventing scattering when broken. Various resin films have been used and proposed for glass substrate reinforcement.

For example, Patent Document 1 discloses a method for obtaining a transparent substrate by forming a resin layer on a thin plate glass by solution coating, and a method for forming a resin layer by adhering a resin film on a thin plate glass via an adhesive layer. A method of obtaining a transparent substrate by using a method is described. Patent Document 2 describes forming a thermoplastic resin layer on glass by applying a casting solution containing a thermoplastic resin having a terminal hydroxyl group and an epoxy terminal coupling agent onto inorganic glass. ing.

JP 2011-88789 A WO2010/053092

A laminate including a glass layer and a resin layer, which is used as a window film or the like in an electronic display device or the like, is required to have strong adhesion between the resin layer and the glass layer.

Accordingly, an object of the present invention is to obtain a laminate that has high adhesion between a resin layer and inorganic glass and is useful as a window film or the like for a display device.

In order to solve the above-mentioned problems, the present inventors conducted intensive studies on the layer structure of the laminate, the composition of the resin layer, etc. As a result, a resin layer formed from a specific resin composition was directly laminated on the glass layer. The inventors have found that the above problems can be solved by a laminate, and have completed the present invention. That is, the present invention includes the following aspects.

[1] A laminate having an inorganic glass (A) and a resin layer (B) directly laminated on at least one surface of the inorganic glass (A),
The resin layer (B) includes at least one resin selected from the group consisting of polyimide resins and polyamide resins, a filler having an average primary particle size of 1 to 50 nm, an isocyanate group, a blocked isocyanate group, an epoxy group, and glycidyl. formed from a resin composition containing a silane coupling agent having at least one group selected from the group consisting of a group and an oxetanyl group,
laminate.
[2] The laminate according to [1], wherein the resin is a fluorine atom-containing resin.
[3] The surface of the inorganic glass (A) with which the resin layer (B) is in contact has a contact angle of 80° or less measured according to the sessile drop method described in JIS R 3257:1999 [1] Or the laminate according to [2].
[4] The laminate according to any one of [1] to [3], wherein the content of the resin is 50 to 99 parts by mass with respect to 100 parts by mass of the solid content of the resin composition.
[5] The content of the silane coupling agent is 0.1 to 10 parts by mass with respect to 100 parts by mass of at least one resin selected from the group consisting of polyimide resins and polyamide resins [1] The laminate according to any one of to [4].
[6] The content of the filler having an average primary particle diameter of 1 to 50 nm is 0.1 to 60 parts by mass with respect to 100 parts by mass of the solid content of the resin composition, [1] to [5] A laminate according to any one of the above.
[7] The laminate according to any one of [1] to [6], wherein the filler having an average primary particle size of 1 to 50 nm is composed of silica.
[8] The laminate according to any one of [1] to [7], wherein the silane coupling agent is a silane coupling agent having an isocyanate group and/or a blocked isocyanate group.
[9] The content of the silane coupling agent is 0.1 to 10 parts by mass with respect to 100 parts by mass of at least one resin selected from the group consisting of polyimide resins and polyamide resins [1] The laminate according to any one of [8].
[10] The laminate according to any one of [1] to [9], which has a total light transmittance of 85% or more.
[11] The laminate according to any one of [1] to [10], which has a YI value of 5.0 or less.
[12] The laminate according to any one of [1] to [11], wherein a hard coat layer is further laminated on the surface of the resin layer (B) opposite to the surface in contact with the glass layer.
[13] The laminate according to any one of [1] to [12], which is used as a window film for display devices.
[14] at least one resin selected from the group consisting of polyimide resins and polyamide resins;
A filler having an average primary particle size of 1 to 50 nm,
a silane coupling agent having at least one group selected from the group consisting of an isocyanate group, a blocked isocyanate group, an epoxy group, a glycidyl group and an oxetanyl group;
Resin composition.
[15] The content of the silane coupling agent is 0.1 to 10 parts by mass with respect to 100 parts by mass of at least one resin selected from the group consisting of polyimide resins and polyamide resins, [14] The resin composition according to .
[16] A composition for forming a glass protective film, comprising the resin composition according to [14] or [15].
[17] A display device comprising the laminate according to any one of [1] to [13].
[18] The display device according to [17], further comprising a polarizing plate.
[19] The display device according to [17] or [18], further comprising a touch sensor.
[20] The display device according to any one of [17] to [19], which is a flexible display device.

ADVANTAGE OF THE INVENTION According to this invention, the adhesiveness of an inorganic glass and a resin layer is high, and the laminated body useful as a window film of a display apparatus etc. can be provided.

It is a figure for demonstrating the measuring method of the peel strength between a resin layer and a glass layer.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the gist of the present invention. In addition, when a plurality of upper and lower limits are described for a specific parameter, any upper and lower limits of these upper and lower limits can be combined to form a suitable numerical range.

The laminate of the present invention is a laminate comprising an inorganic glass (A) and a resin layer (B) directly laminated on at least one surface of the inorganic glass (A).
In the present invention, since the resin layer (B) is directly laminated on the inorganic glass (A), compared to a laminate in which the resin layer is laminated on the inorganic glass (A) via an adhesive layer or a primer layer, Excellent in nature. When the resin layer is laminated on the inorganic glass (A) via an adhesive layer or a primer layer, the film thickness of the resin layer tends to be non-uniform, which may cause deterioration in visibility. In particular, when the latter laminate is applied as a flexible member, the adhesive or primer at the bent portion may be plastically deformed, and the visibility at the bent portion tends to decrease.
As a result of studies by the present inventors, it was found that polyimide-based resins and polyamide-based resins tend to have insufficient adhesion to glass. However, in the present invention, since it is formed from the above resin composition containing a specific silane coupling agent and a filler, the resin layer having a polyimide resin or polyamide resin is directly laminated on the inorganic glass (A). In spite of the above, the adhesion to the inorganic glass (A) is excellent.

<Inorganic glass (A)>
The inorganic glass (A) (hereinafter sometimes referred to as glass) is not particularly limited as long as it is an inorganic glass layer having a thin film shape. Specific examples of the composition of the inorganic glass (A) include, for example, a composition represented by mol % based on the metals and semi-metal oxides illustrated below, and containing 50 to 80 mol % of SiO ₂ and Al ₂ O ₃ . 0.1 to 25 mol %, the sum of Li ₂ O, Na ₂ O and K ₂ O is 3 to 30 mol %, MgO is 0 to 25 mol %, CaO is 0 to 25 mol % and ZrO ₂ is 0 to A glass containing 5 mol % is exemplified. More specifically, the following glass compositions may be mentioned. Note that, for example, "containing 0 to 25 mol % of MgO" means that MgO is not essential, but may be contained up to 25 mol %. Glass (i) shown below is included in soda lime silicate glass, and glasses (ii), (iii), and (iv) are included in aluminosilicate glass.
(i) _63-73 mol% of _SiO2 , 0.1-5.2 mol% of _Al2O3 , 10-16 mol% of _Na2O , K A glass containing 0-1.5 mol % of ₂ O, 0-5 mol % of Li ₂ O, 5-13 mol % of MgO and 4-10 mol % of CaO.
(ii) 50-74 mol% of _SiO2 , 1-10 mol% of _Al2O3 , 6-14 mol% of _{Na2O ,} and ₃ K2O in a composition expressed in mol% based on oxides; ~11 mol% Li ₂ O 0-5 mol% MgO 2-15 mol% CaO 0-6 mol% _and ZrO 0-5 mol%, SiO ₂ and Al ₂ O ₃ Glass having a total content of 75 mol % or less, a total content of Na ₂ O and K ₂ O of 12 to 25 mol %, and a total content of MgO and CaO of 7 to 15 mol %.
(iii) 68-80 mol% of _SiO2 , 4-10 mol% of _Al2O3 , 5-15 mol% of _Na2O , and 0 _K2O in a composition expressed in _mol % based on oxides; 1 mol % Li ₂ O 0-5 mol % MgO 4-15 mol % and ZrO ₂ 0-1 mol %.
(iv) 67-75 mol % SiO ₂ , 0-4 mol % Al ₂ O ₃ , 7-15 mol % Na ₂ O, and 1 K ₂ O, in mol % based on oxides; ~9 mol%, Li ₂ O 0-5 mol%, MgO 6-14 mol% and ZrO ₂ 0-1.5 mol%, and the total content of SiO ₂ and Al ₂ O ₃ is 71 ˜75 mol %, the total content of Na ₂ O and K ₂ O is 12-20 mol %, and the content of CaO, if any, is less than 1 mol %.

(Glass manufacturing method)
In the production of the inorganic glass (A), each step shown below is not particularly limited and may be appropriately selected, and typically conventionally known steps can be applied. For example, first, raw materials for each component are prepared so as to have a composition described later, and heated and melted in a glass melting furnace. The glass is homogenized by bubbling, stirring, addition of a clarifier, etc., formed into a glass plate having a predetermined thickness by a conventionally known forming method, and slowly cooled.

Glass forming methods include, for example, a float method, a press method, a fusion method, a down-draw method and a roll-out method, and the float method is preferred because it is suitable for mass production. A fusion method and a down-draw method, which are continuous forming methods other than the float method, are also suitable.
The molded glass is subjected to treatment such as grinding and polishing, if necessary, chemical strengthening treatment, and then washed and dried. After that, by performing processing such as cutting and polishing, an inorganic glass suitable for a display device or the like can be obtained.

(Chemical strengthening treatment)
In one preferred embodiment of the invention, the inorganic glass may be chemically strengthened glass. When inorganic glass is chemically strengthened, a compressive stress layer is formed on the surface, and the strength and scratch resistance of inorganic glass are enhanced. The chemical strengthening treatment is performed by exchanging alkali metal ions with a small ionic radius present on the main surface of the inorganic glass with alkali metal ions with a large ionic radius. Li ions or Na ions in the inorganic glass are converted into alkali ions having a larger ionic radius in the molten salt, typically Na ions or K ions for Li ions, Na For ions it is done by exchanging for K ions, respectively. The chemical strengthening treatment can be carried out by a conventionally known method, generally by immersing the inorganic glass in potassium nitrate molten salt. Potassium carbonate may be added to this molten salt in an amount of about 10% by mass based on the molten salt. As a result, cracks and the like on the surface layer of the inorganic glass can be removed, and a high-strength inorganic glass can be obtained. Further, the chemical strengthening treatment is not limited to one time, and may be performed twice or more under different conditions, for example.

In one preferred embodiment of the invention, the inorganic glass is flexible glass. Flexible glass is flexible glass that is thin enough to bend. The flexible glass is preferably the chemically strengthened glass described above. When flexible glass is used as the glass layer, the thickness of the glass layer is preferably 10 to 200 μm, more preferably 20 to 150 μm, from the viewpoint of strength and bending resistance of the laminate. Although the reason is not clear, the flexibility of flexible glass may be reduced by heat treatment at a high temperature, for example, at a temperature of 250° C. or higher or 300° C. or higher. Therefore, when a laminate containing flexible glass and a resin layer (B) directly laminated on the glass is produced at a relatively low temperature, the adhesion cannot be sufficiently improved due to the low heating temperature. When the heating temperature is increased, the flexibility of the flexible glass layer may deteriorate. According to the laminate of the present invention, the adhesiveness between the glass and the resin layer can be sufficiently enhanced even when the laminate is produced under relatively low temperature heating conditions such as 250° C. or lower, preferably 230° C. or lower. Therefore, it is possible to provide a laminate having both a low haze value, a low YI value, a high total light transmittance, and flexibility while being able to improve adhesion.

The thickness of the inorganic glass (A) is generally 10-5,000 μm, preferably 20-3,000 μm, more preferably 30-2,500 μm. As the inorganic glass (A) used in the present invention, a flexible glass made thin enough to be curved can be used. The thickness of the flexible glass can be appropriately set within a range in which the flexible glass exhibits flexibility, and is preferably 5 to 300 μm, more preferably 10 to 200 μm, still more preferably 20 to 150 μm, still more preferably 30 to 100 μm. .

In the inorganic glass (A), the contact angle of at least one surface laminated with the resin layer is measured according to the static drop method described in Japanese Industrial Standards (JIS) R 3257:1999, and is preferably 80° or less. , more preferably 70° or less, still more preferably 60° or less, still more preferably 55° or less, and usually 0° or more. When the contact angle is within the above range, the adhesion between the inorganic glass (A) and the resin layer (B) tends to be good. For example, the contact angle can be made within the above range by washing the inorganic glass (A) before applying the varnish.

Examples of the method for cleaning the inorganic glass include treatments for hydrophilizing the glass surface, such as corona discharge treatment, ozone treatment and plasma treatment, preferably corona discharge treatment. The corona discharge treatment is a treatment in which glass is placed between electrodes and a high voltage is applied between the electrodes to discharge and activate the glass surface. The conditions for the corona discharge treatment vary depending on the shape of the electrodes, the distance between the electrodes, the amount of discharge, the humidity, etc., but examples of the shape of the electrodes include wire-like electrodes and segment electrodes. It is preferable to set the discharge amount to 10 to 200 W·min/m ² and the corona discharge treatment speed to about 3 to 20 m/min. Also, the absolute humidity of the corona discharge treated part is preferably 10 to 30 g/m ³ . When the absolute humidity is within the above range, the discharge is stably performed without generating sparks.

The inorganic glass (A) may be a commercially available glass as long as it exhibits the above contact angle. Examples of commercially available inorganic glasses include S9213 (Matsunami Glass Industry Co., Ltd.) and G-Leaf (Japan Electric Glass Co., Ltd.), EAGLE XG (Corning), and the like. Further, by using a flexible glass, it can be used as a front panel of a flexible display device.

<Resin layer (B)>
The resin layer (B) contains at least one resin selected from the group consisting of polyimide resins and polyamide resins, a filler having an average primary particle size of 1 to 50 nm, an isocyanate group, a blocked isocyanate group, an epoxy group, a glycidyl group and oxetanyl. It is formed from a resin composition containing a silane coupling agent having at least one group selected from the group consisting of groups, and further containing additives, solvents and the like as necessary. The present invention also provides the above resin composition. The resin layer (B) may be a single layer or multiple layers, preferably a single layer.

As used herein, a polyimide resin represents at least one resin selected from the group consisting of a polyimide resin, a polyamideimide resin, a polyimide precursor resin, and a polyamideimide precursor resin. A polyimide resin is a resin containing a repeating structural unit containing an imide group, and a polyamideimide resin is a resin containing a repeating structural unit containing both an imide group and an amide group. The polyimide precursor resin and the polyamideimide precursor resin are precursors before imidization that give a polyimide resin and a polyamideimide resin by imidization, respectively, and are also referred to as polyamic acids. Further, in this specification, a polyamide-based resin is a resin containing a repeating structural unit containing an amide group. The transparent resin film of the present invention may contain one kind of polyimide resin or polyamide resin, or may contain two or more kinds of polyimide resins and/or polyamide resins in combination. The transparent resin film of the present invention preferably contains a polyimide resin from the viewpoint of the chemical properties and physical properties of the transparent resin film, and the polyimide resin is preferably a polyimide resin or a polyamideimide resin, and more Preferred is a polyamideimide resin.

In a preferred embodiment of the present invention, the polyimide-based resin and the polyamide-based resin are preferably aromatic resins from the viewpoint of the chemical and physical properties of the laminate including the resin layer (B). In the present specification, the aromatic resin refers to a resin in which structural units contained in polyimide resins and polyamide resins are mainly aromatic structural units.

In the above preferred embodiment, from the viewpoint of the chemical properties and physical properties of the laminate containing the resin layer (B), the aromatic monomer for all structural units contained in the polyimide resin and the polyamide resin The proportion of the structural units is preferably 60 mol % or more, more preferably 70 mol % or more, even more preferably 80 mol % or more, still more preferably 85 mol % or more. Here, the structural unit derived from an aromatic monomer is derived from a monomer containing at least a portion of an aromatic structure (e.g., an aromatic ring), and at least a portion of the aromatic structure (e.g., an aromatic ring) is It is a structural unit contained in Examples of aromatic monomers include aromatic tetracarboxylic acid compounds, aromatic diamines, and aromatic dicarboxylic acids.

In one preferred embodiment of the present invention, the polyimide resin has the formula (1):

［式（１）中、Ｙは４価の有機基を表し、Ｘは２価の有機基を表し、＊は結合手を表す］
で表される構成単位を有するポリイミド樹脂であるか、又は、式（１）で表される構成単位及び式（２）：

[In formula (1), Y represents a tetravalent organic group, X represents a divalent organic group, and * represents a bond]
or a structural unit represented by formula (1) and formula (2):

［式（２）中、Ｚ及びＸは、互いに独立に、２価の有機基を表し、＊は結合手を表す］
で表される構成単位を有するポリアミドイミド樹脂であることが好ましい。また、ポリアミド系樹脂は、式（２）で表される構成単位を有するポリアミド樹脂であることが好ましい。以下において式（１）及び式（２）について説明するが、式（１）についての説明は、ポリイミド樹脂及びポリアミドイミド樹脂の両方に関し、式（２）についての説明は、ポリアミド樹脂及びポリアミドイミド樹脂の両方に関する。

[In formula (2), Z and X independently represent a divalent organic group, * represents a bond]
It is preferably a polyamide-imide resin having a structural unit represented by. Moreover, the polyamide-based resin is preferably a polyamide resin having a structural unit represented by formula (2). Formulas (1) and (2) are described below, but the description of formula (1) relates to both polyimide resins and polyamideimide resins, and the description of formula (2) relates to polyamide resins and polyamideimide resins. regarding both.

The structural unit represented by formula (1) is a structural unit formed by reacting a tetracarboxylic acid compound and a diamine compound, and the structural unit represented by formula (2) is a dicarboxylic acid compound and a diamine compound. is a structural unit formed by reacting with

In formula (2), Z is a divalent organic group, preferably an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms (these A hydrogen atom in the group may be substituted with a halogen atom, preferably a fluorine atom, and is a divalent organic group having 4 to 40 carbon atoms, more preferably 1 to 6 carbon atoms. , an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms (the hydrogen atoms in these groups may be substituted with halogen atoms, preferably fluorine atoms). is a divalent organic group having 4 to 40 carbon atoms and having a cyclic structure. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, or the aryl group having 6 to 12 carbon atoms are exemplified for R ^3a and R ^3b in formula (3) described later. The same applies. Cyclic structures include alicyclic, aromatic and heterocyclic structures. As the organic group of Z, formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) and equation (29):

［式（２０）～式（２９）中、Ｗ^１は、単結合、－Ｏ－、－ＣＨ_２－、－ＣＨ_２－ＣＨ_２－、－ＣＨ（ＣＨ_３）－、－Ｃ（ＣＨ_３）_２－、－Ｃ（ＣＦ_３）_２－、－Ａｒ－、－ＳＯ_２－、－ＣＯ－、－Ｏ－Ａｒ－Ｏ－、－Ａｒ－Ｏ－Ａｒ－、－Ａｒ－ＣＨ_２－Ａｒ－、－Ａｒ－Ｃ（ＣＨ_３）_２－Ａｒ－又は－Ａｒ－ＳＯ_２－Ａｒ－を表し、ここで、Ａｒは、互いに独立に、水素原子がフッ素原子で置換されていてもよい炭素数６～２０のアリーレン基、例えばフェニレン基を表し、＊は結合手を表す］
で表される基の結合手のうち、隣接しない２つが水素原子に置き換わった基及び炭素数６以下の２価の鎖式炭化水素基が例示され、Ｚのヘテロ環構造としてはチオフェン環骨格を有する基が例示される。透明樹脂フィルムの黄色度の指標であるＹＩ値を低減しやすい観点から、低減しやすい観点から、式（２０）～式（２９）で表される基、及び、チオフェン環骨格を有する基が好ましく、式（２６）、式（２８）及び式（２９）で表される基がより好ましい。

[In the formulas (20) to (29), W ¹ is a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) _2- , -C(CF ₃ ) ₂ -, -Ar-, -SO ₂ -, -CO-, -O-Ar-O-, -Ar-O-Ar-, -Ar-CH ₂ -Ar-, —Ar—C(CH ₃ ) ₂ —Ar— or —Ar—SO ₂ —Ar—, wherein Ar independently represents 6 to 6 carbon atoms in which hydrogen atoms may be substituted with fluorine atoms; 20 represents an arylene group, such as a phenylene group, * represents a bond]
Among the bonds of the group represented by, a group in which two non-adjacent hydrogen atoms are replaced with hydrogen atoms and a divalent chain hydrocarbon group having 6 or less carbon atoms are exemplified, and the heterocyclic structure of Z is a thiophene ring skeleton are exemplified. From the viewpoint of easy reduction of the YI value, which is an index of the yellowness of the transparent resin film, groups represented by formulas (20) to (29) and groups having a thiophene ring skeleton are preferred. , Formula (26), Formula (28) and Formula (29) are more preferred.

The organic group of Z includes formula (20′), formula (21′), formula (22′), formula (23′), formula (24′), formula (25′), formula (26′), formula (27′), formula (28′) and formula (29′):

［式（２０’）～式（２９’）中、Ｗ^１及び＊は、式（２０）～式（２９）において定義した通りである］
で表される２価の有機基がより好ましい。なお、式（２０）～式（２９）及び式（２０’）～式（２９’）における環上の水素原子は、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、又は炭素数６～１２のアリール基（これらの基における水素原子はハロゲン原子、好ましくはフッ素原子で置換されていてもよい）で置換されていてもよい。

[In formulas (20′) to (29′), W ¹ and * are as defined in formulas (20) to (29)]
A divalent organic group represented by is more preferable. The hydrogen atoms on the rings in formulas (20) to (29) and formulas (20') to (29') are alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, or It may be substituted with an aryl group having 6 to 12 carbon atoms (hydrogen atoms in these groups may be substituted with halogen atoms, preferably fluorine atoms).

Polyamide-based resin or polyamide-imide resin, when Z in formula (2) has a structural unit represented by any of the above formulas (20') to (29'), especially in formula (2) When Z has a structural unit represented by the formula (3′) described later, the polyamide-based resin or polyamideimide resin, in addition to the structural unit, has the following formula (d1):

［式（ｄ１）中、Ｒ^２４は後述する式（３）中のＲ^３ａについて定義する基又は水素原子であり、Ｒ^２５は、Ｒ^２４又は－Ｃ（＝Ｏ）－＊を表し、＊は結合手を表す］
で表されるカルボン酸由来の構成単位をさらに有することが、樹脂組成物の粘度を低くしやすく、樹脂組成物の成膜性を高めやすく、積層体における樹脂層の均一性を高めやすい観点から好ましい。構成単位（ｄ１）としては、具体的には、Ｒ^２４及びＲ^２５がいずれも水素原子である構成単位、すなわちジカルボン酸化合物に由来する構成単位や、Ｒ^２４がいずれも水素原子であり、Ｒ^２５が－Ｃ（＝Ｏ）－＊を表す構成単位、すなわちトリカルボン酸化合物に由来する構成単位等が挙げられる。

[In formula (d1), R ²⁴ is a group or a hydrogen atom defined for R ^3a in formula (3) described later, R ²⁵ represents R ²⁴ or -C(=O)-*, * is represents a bond]
Further having a structural unit derived from a carboxylic acid represented by, it is easy to lower the viscosity of the resin composition, easy to improve the film-forming properties of the resin composition, from the viewpoint of easy to improve the uniformity of the resin layer in the laminate preferable. Specific examples of the structural unit (d1) include a structural unit in which both R ²⁴ and R ²⁵ are hydrogen atoms, that is, a structural unit derived from a dicarboxylic acid compound, and a structural unit in which both R ²⁴ are hydrogen atoms and R Structural units in which ²⁵ represents -C(=O)-*, that is, structural units derived from tricarboxylic acid compounds.

The polyamide-based resin or polyamide-imide resin may contain multiple types of Z as Z in formula (2), and the multiple types of Z may be the same or different. In particular, Z in Formula (2) is preferably Formula (3):

［式（３）中、Ｒ^３ａ及びＲ^３ｂは、互いに独立に、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、又は炭素数６～１２のアリール基を表し、Ｒ^３ａ及びＲ^３ｂに含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、
Ｗは、互いに独立に、単結合、－Ｏ－、－ＣＨ_２－、－ＣＨ_２－ＣＨ_２－、－ＣＨ（ＣＨ_３）－、－Ｃ（ＣＨ_３）_２－、－Ｃ（ＣＦ_３）_２－、－ＳＯ_２－、－Ｓ－、－ＣＯ－又は－Ｎ（Ｒ^９）－を表し、Ｒ^９は水素原子、ハロゲン原子で置換されていてもよい炭素数１～１２の１価の炭化水素基を表し、
ｓは０～４の整数であり、ｔは０～４の整数であり、ｕは０～４の整数であり、＊は結合手を表す］
、より好ましくは式（３’）：

[In formula (3), R ^3a and R ^3b each independently represent an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group ^having 6 to 12 carbon atoms; and the hydrogen atoms contained in R ^3b are each independently optionally substituted with a halogen atom,
W is independently of each other a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO- or -N(R ⁹ )-, where R ⁹ is a hydrogen atom or a monovalent C 1-12 monovalent represents a hydrocarbon group,
s is an integer of 0 to 4, t is an integer of 0 to 4, u is an integer of 0 to 4, * represents a bond]
, more preferably formula (3′):

［式（３’）中、Ｒ^３ａ、Ｒ^３ｂ、ｓ、ｔ、ｕ、Ｗ及び＊は、式（３）において定義した通りである］
で表される構成単位を少なくとも有することが好ましい。なお、本明細書において、ポリアミド系樹脂又はポリアミドイミド樹脂が式（２）中のＺが式（３）で表される構成単位を有することと、ポリアミド系樹脂又はポリアミドイミド系樹脂が式（２）中のＺとして式（３）で表される構造を有することとは、同様の意味を有し、ポリアミド系樹脂又はポリアミドイミド樹脂に含まれる複数の式（２）で表される構成単位のうち、少なくとも一部の構成単位におけるＺが式（３）で表されることを意味する。当該記載は、他の同様の記載にもあてはまる。

[In formula (3′), R ^3a , R ^3b , s, t, u, W and * are as defined in formula (3)]
It is preferable to have at least a structural unit represented by. In the present specification, the polyamide-based resin or the polyamideimide resin has a structural unit represented by Z in the formula (2) and the polyamide-based resin or the polyamideimide-based resin is represented by the formula (2 Having a structure represented by formula (3) as Z in ) has the same meaning, and a plurality of structural units represented by formula (2) contained in a polyamide resin or polyamideimide resin Among them, it means that Z in at least some structural units is represented by formula (3). The statement applies to other similar statements as well.

In Formula (3) and Formula (3′), W is independently a single bond, —O—, —CH ₂ —, —CH ₂ —CH ₂ —, —CH(CH ₃ )—, —C( represents CH ₃ ) ₂ —, —C(CF ₃ ) ₂ —, —SO ₂ —, —S—, —CO— or —N(R ⁹ )—, and when the inorganic glass in the laminate is flexible glass, , preferably -O- or -S-, more preferably -O-, from the viewpoint of easily increasing the flex resistance of the laminate.
R ^3a and R ^3b each independently represent an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of alkyl groups having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, 2 -methyl-butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl group and the like. Examples of alkoxy groups having 1 to 6 carbon atoms include methoxy, ethoxy, propyloxy, isopropyloxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy and hexyloxy. group, cyclohexyloxy group, and the like. Examples of the aryl group having 6 to 12 carbon atoms include phenyl group, tolyl group, xylyl group, naphthyl group, biphenyl group and the like. From the viewpoint of surface hardness and flexibility of the optical film, R ^3a and R ^3b independently represent preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. Here, hydrogen atoms contained in R ^3a and R ^3b may be independently substituted with halogen atoms.
R ⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of monovalent hydrocarbon groups having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n- pentyl group, 2-methyl-butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group, n-decyl groups, etc., which may be substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

t and u in formula (3) and formula (3′) are each independently an integer of 0 to 4, preferably an integer of 0 to 2, more preferably 0 or 1, still more preferably 0 be.

s in formula (3) and formula (3′) is an integer of 0 to 4, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, more preferably 0 or 1, still more preferably is 0. When s is within this range, various physical properties of the transparent resin film can be more easily improved. The structural unit represented by formula (3) or formula (3′) in which s is 0 is, for example, a structural unit derived from terephthalic acid or isophthalic acid, and the structural unit is preferably represented by formula (3) or formula It is a structural unit in which s and u in (3′) are each 0. From the viewpoint of easily improving various chemical properties and physical properties of the transparent resin film, the polyamide-imide resin or polyamide-based resin preferably contains structural units derived from terephthalic acid. The polyamide-imide resin or polyamide-based resin may include, in Z, one or more of the structural units represented by the formula (3) or (3'). From the viewpoint of improving various chemical properties and physical properties of the transparent resin film and reducing the YI value, the polyamide-imide resin or polyamide-based resin is preferably represented by Z in formula (3) or in formula (3′). Two or more types of structural units with different values of s are included, and more preferably two types or three types of structural units with different values of s in formula (3) or formula (3') are included. In this case, from the viewpoint of easily improving various chemical and physical properties of the transparent resin film and from the viewpoint of easily reducing the YI value of the transparent resin film, the polyamide-imide resin or polyamide-based resin is represented by formula (2). As Z in the structural unit represented by It is more preferable to further contain a structural unit containing In addition to the structural unit represented by formula (2) having Z represented by formula (3) where s is 0, it is also preferable to further have a structural unit represented by the above formula (d1). .

In a preferred embodiment of the present invention, the polyamide-imide resin or polyamide-based resin is a structural unit having s = 0 and u = 0 as the structural unit represented by formula (3) or formula (3') have In a more preferred embodiment of the present invention, the polyamideimide resin or polyamide-based resin has s = 0 and u = 0 as structural units represented by formula (3) or formula (3') Units and equation (3″):

で表される構成単位を有する。この場合、樹脂層の種々の化学的特性及び物理的特性を向上させやすいと共に、積層体のＹＩ値を低減しやすい。

It has a structural unit represented by In this case, it is easy to improve various chemical properties and physical properties of the resin layer, and it is easy to reduce the YI value of the laminate.

When the polyamideimide resin or polyamide resin has a structural unit represented by the formula (3) or formula (3′), the proportion thereof is the structure represented by the formula (1) of the polyamideimide resin or polyamide resin When the total amount of units and structural units represented by formula (2) is 100 mol%, it is preferably 20 mol% or more, more preferably 30 mol% or more, still more preferably 40 mol% or more, still more preferably It is 50 mol % or more, particularly preferably 60 mol % or more, preferably 90 mol % or less, more preferably 85 mol % or less, still more preferably 80 mol % or less. When the proportion of the structural unit represented by formula (3) or formula (3') is at least the above lower limit, various chemical and physical properties of the transparent resin film are likely to be enhanced. When the ratio of the structural unit represented by formula (3) or formula (3′) is equal to or less than the above upper limit, the increase in viscosity of the resin-containing varnish due to hydrogen bonding between amide bonds derived from formula (3) is suppressed, and the film It is easy to improve the workability of

Further, when the polyamideimide resin or polyamide resin has a structural unit represented by formula (3) or formula (3') where s is 1 to 4, formula (3) or formula where s is 1 to 4 The ratio of the structural unit represented by (3′) is 100 mol% of the total of the structural units represented by the formula (1) and the structural unit represented by the formula (2) of the polyamideimide resin or polyamide resin. When the % or less, more preferably 50 mol % or less, still more preferably 30 mol % or less. When the ratio of the structural unit represented by formula (3) or formula (3′) in which s is 1 to 4 is at least the above lower limit, various chemical and physical properties of the transparent resin film are likely to be enhanced. . When the ratio of the structural units represented by the formula (3) in which s is 1 to 4 is equal to or less than the above upper limit, hydrogen between amide bonds derived from the structural units represented by the formula (3) or the formula (3′) It suppresses the increase in the viscosity of the resin-containing varnish due to bonding, and tends to improve the workability of the film. The ratio of the structural units represented by formula (1), formula (2), formula (3), or formula (3′) can be measured, for example, using ¹ H-NMR, or It can also be calculated from the ratio.

In a preferred embodiment of the present invention, Z in the polyamideimide resin or polyamide resin is preferably 30 mol% or more, more preferably 40 mol% or more, still more preferably 45 mol% or more, and even more preferably 50 mol. % or more are structural units represented by formula (3) or formula (3′) in which s is 0 to 4. When Z is at least the above lower limit and is a structural unit represented by formula (3) or formula (3') in which s is 0 to 4, various physical properties of the transparent resin film are likely to be enhanced. Further, 100 mol % or less of Z in the polyamideimide resin or polyamide resin may be a structural unit represented by formula (3) or formula (3′) in which s is 0 to 4. The ratio of structural units represented by formula (3) or formula (3′) in which s is 0 to 4 in the resin can be measured, for example, using ¹ H-NMR, or It can also be calculated from the preparation ratio.

In a preferred embodiment of the present invention, Z in the polyamideimide resin or polyamide resin is preferably 5 mol% or more, more preferably 8 mol% or more, still more preferably 10 mol% or more, and still more preferably 12 mol. % or more is represented by formula (3) or formula (3′) in which s is 1 to 4. When Z of the polyamideimide resin or polyamide resin is at least the above lower limit and is represented by formula (3) or formula (3′) in which s is 1 to 4, various physical properties of the transparent resin film are enhanced. Cheap. Z is preferably 90 mol% or less, more preferably 70 mol% or less, still more preferably 50 mol% or less, and even more preferably 30 mol% or less of formula (3) wherein s is 1 to 4, or It is represented by Formula (3'). When the above upper limit or less of Z is represented by formula (3) where s is 1 to 4, structural units derived from structural units represented by formula (3) or formula (3') where s is 1 to 4 It suppresses the viscosity increase of the resin-containing varnish due to hydrogen bonding between amide bonds, and easily improves the workability of the film. The ratio of structural units represented by formula (3) or formula (3′) in which s is 1 to 4 in the resin can be measured, for example, using ¹ H-NMR, or can also be calculated from

In formula (1) and formula (2), each X is independently a divalent organic group, preferably a divalent organic group having 4 to 40 carbon atoms, more preferably a divalent organic group having 4 to 40 carbon atoms and having a cyclic structure. represents a divalent organic group. Cyclic structures include alicyclic, aromatic and heterocyclic structures. In the organic group, the hydrogen atoms in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group, in which case the number of carbon atoms in the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably is 1-8. In one embodiment of the present invention, the polyamideimide resin of the present invention may contain multiple types of X, and the multiple types of X may be the same or different. X is represented by formula (10), formula (11), formula (12), formula (13), formula (14), formula (15), formula (16), formula (17) and formula (18) a group in which the hydrogen atoms in the groups represented by the formulas (10) to (18) are substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and a chain having 6 or less carbon atoms Formula hydrocarbon groups are exemplified.

[In the formulas (10) to (18), * represents a bond,
V ¹ , V ² and V ³ are each independently a single bond, —O—, —S—, —CH ₂ —, —CH ₂ —CH ₂ —, —CH(CH ₃ )—, —C(CH ₃ ) represents _2- , -C(CF ₃ ) ₂ -, -SO ₂ -, -CO- or -N(Q)-; Here, Q represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. ]

Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms for Q include the same groups as those defined for R ⁹ .
One example is V ¹ and V ³ are a single bond, -O- or -S- and V ² is -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ - or -SO ₂ -. The bonding positions of V ¹ and V ² to each ring and the bonding positions of V ² and V ³ to each ring independently of each other are preferably meta-position or para-position, more preferably para-position. rank.

Among the groups represented by formulas (10) to (18), from the viewpoint of easily improving the adhesion between the resin layer and the glass layer, transparency, and flex resistance, formulas (13) and (14) , Formulas (15), (16) and (17) are preferred, and groups of Formulas (14), (15) and (16) are more preferred. In addition, V ¹ , V ² and V ³ are preferably single bonds, -O- or -S- , more preferably a single bond or -O-.

In a preferred embodiment of the present invention, the polyamide-based resin and the polyimide-based resin have the formula (4) as X in the formula (1) or X in the formula (2):

［式（４）中、Ｒ^１０～Ｒ^１７は、互いに独立に、水素原子、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基又は炭素数６～１２のアリール基を表し、Ｒ^１０～Ｒ^１７に含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、＊は結合手を表す］
で表される構造を含む。式（１）及び式（２）で表される複数の構成単位中のＸの少なくとも一部が式（４）で表される構造であると、樹脂層とガラス層との密着性、透明性、及び耐屈曲性を高めやすい。

[In formula (4), R ¹⁰ to R ¹⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, The hydrogen atoms contained in R ¹⁰ to R ¹⁷ may be independently substituted with halogen atoms, and * represents a bond]
contains the structure represented by When at least part of X in the plurality of structural units represented by formulas (1) and (2) has a structure represented by formula (4), the adhesion and transparency between the resin layer and the glass layer are improved. , and flex resistance is likely to be increased.

In formula (4), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms, represents an alkoxy group of ~6 or an aryl group of 6 to 12 carbon atoms. The alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms is an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms in formula (3). or the groups exemplified as the aryl group having 6 to 12 carbon atoms. R ¹⁰ to R ¹⁷ each independently represent preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, where R ¹⁰ to R ¹⁷ The hydrogen atoms contained in may be substituted with halogen atoms independently of each other. Halogen atoms include, for example, fluorine, chlorine, bromine and iodine atoms. R ¹⁰ to R ¹⁷ are each independently from the viewpoint of various physical properties of the transparent resin film, more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, still more preferably R ¹⁰ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are hydrogen atoms; R ¹¹ and R ¹⁷ are hydrogen atoms, methyl groups, fluoro groups, chloro groups or trifluoromethyl groups; ¹¹ and ^R17 are a methyl group or a trifluoromethyl group.

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

で表される構成単位であり、すなわち、式（１）及び式（２）で表される複数の構成単位中のＸの少なくとも一部は、式（４’）で表される構成単位である。この場合、フッ素元素を含有する骨格によりポリイミド系樹脂又はポリアミド系樹脂の溶媒への溶解性を高め、該樹脂を含有するワニスの保管安定性を向上しやすいと共に、該ワニスの粘度を低減しやすく、透明樹脂フィルムの加工性を向上しやすい。また、フッ素元素を含有する骨格により、透明樹脂フィルムの光学特性を向上しやすい。

That is, at least part of X in the plurality of structural units represented by formulas (1) and (2) is a structural unit represented by formula (4′) . In this case, the skeleton containing fluorine element increases the solubility of the polyimide resin or polyamide resin in the solvent, and the storage stability of the varnish containing the resin is easily improved, and the viscosity of the varnish is easily reduced. , easy to improve the processability of the transparent resin film. In addition, the skeleton containing elemental fluorine makes it easy to improve the optical properties of the transparent resin film.

In a preferred embodiment of the present invention, preferably 30 mol% or more, more preferably 50 mol% or more, and even more preferably 70 mol% or more of X in the polyimide resin or polyamide resin is represented by formula (4), In particular, it is represented by the formula (4'). When X within the above range in the polyimide-based resin or polyamide-based resin is represented by formula (4), particularly formula (4′), the obtained transparent resin film has a fluorine element-containing skeleton that allows the resin to react with the solvent. The solubility is increased, the storage stability of the varnish containing the resin is easily improved, the viscosity of the varnish is easily reduced, and the processability of the transparent resin film is easily improved. Moreover, the skeleton containing elemental fluorine facilitates improvement in the optical properties of the transparent resin film. Preferably, 100 mol % or less of X in the polyimide-based resin or polyamide-based resin is represented by formula (4), particularly formula (4'). X in the above resin may be formula (4), especially formula (4'). The ratio of the structural unit represented by the formula (4) of X in the resin can be measured using, for example, ¹ H-NMR, or can be calculated from the charging ratio of raw materials.

In formula (1), Y represents a tetravalent organic group, preferably a tetravalent organic group having 4 to 40 carbon atoms, more preferably a tetravalent organic group having 4 to 40 carbon atoms and having a cyclic structure. show. The cyclic structure includes an alicyclic ring, an aromatic ring, and a heterocyclic structure, and preferably an aromatic ring from the viewpoint of easily increasing impact resistance and elastic modulus. The organic group is an organic group in which a hydrogen atom may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. The number of carbon atoms is preferably 1-8. In one embodiment of the present invention, the polyimide resin may contain multiple types of Y, and the multiple types of Y may be the same or different. Y is represented by the following formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) and a group represented by the formula (29); a group in which hydrogen atoms in the groups represented by the formulas (20) to (29) are substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and tetravalent chain hydrocarbon groups having 6 or less carbon atoms.

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

Among the groups represented by formulas (20) to (29), the groups represented by formulas (20) to (27) are preferred from the viewpoint of easily enhancing various chemical and physical properties of the transparent resin film. is preferred, and a group represented by formula (26) is more preferred. In addition, W ¹ is independent of each other, preferably a single bond, —O—, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -, more preferably a single bond, -O-, - CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -, more preferably a single bond, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -, most preferably a single bond or -C(CF ₃ ) ₂ -.

In a preferred embodiment of the present invention, preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more of Y in the polyimide resin is represented by formula (26). Y within the above range in the polyimide resin is formula (26), preferably formula (26) wherein W ¹ is a single bond, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -, more preferably When W ¹ is a single bond or -C(CF ₃ ) ₂ - represented by Formula (26), various chemical and physical properties of the transparent resin film are likely to be improved, and the YI value of the transparent resin film is easy to reduce. The ratio of structural units in which Y in the polyimide resin is represented by formula (26) can be measured, for example, using ¹ H-NMR, or can be calculated from the feed ratio of raw materials.

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

［式（５）中、Ｒ^１８～Ｒ^２５は、互いに独立に、水素原子、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基又は炭素数６～１２のアリール基を表し、Ｒ^１８～Ｒ^２５に含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、＊は結合手を表す］
及び／又は式（９）

[In formula (5), R ¹⁸ to R ²⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, Hydrogen atoms contained in R ¹⁸ to R ²⁵ may be independently substituted with halogen atoms, and * represents a bond]
and/or formula (9)

［式（９）中、Ｒ^３５～Ｒ^４０は、互いに独立に、水素原子、炭素数１～６のアルキル基又は炭素数６～１２のアリール基を表し、Ｒ^３５～Ｒ^４０に含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、＊は結合手を表す］
で表される。複数の式（１）中のＹの少なくとも一部が式（５）で表される、及び／又は、式（９）で表されると、透明樹脂フィルムの種々の化学的特性及び物理的特性を向上させやすい。

[In formula (9), R ³⁵ to R ⁴⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and the hydrogen contained in R ³⁵ to R ⁴⁰ Atoms may be independently substituted with halogen atoms, * represents a bond]
is represented by When at least part of Y in a plurality of formulas (1) is represented by formula (5) and/or represented by formula (9), various chemical and physical properties of the transparent resin film easy to improve.

In formula (5), R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a represents an alkoxy group of up to 6 or an aryl group of 6 to 12 carbon atoms. The alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms is an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms in formula (3). Examples of the group or the aryl group having 6 to 12 carbon atoms are exemplified above. R ¹⁸ to R ²⁵ each independently represent preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, where R ¹⁸ to R ²⁵ The hydrogen atoms contained in may be substituted with halogen atoms independently of each other. The halogen atoms include fluorine, chlorine, bromine and iodine atoms. R ¹⁸ to R ²⁵ are, independently of each other, from the viewpoint of easily enhancing various physical properties of the transparent resin film, and from the viewpoint of easily enhancing transparency and maintaining the transparency, more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, more preferably R ¹⁸ , R ¹⁹ , R ²⁰ , R ²³ , R ²⁴ and R ²⁵ are hydrogen atoms; R ²¹ and R ²² are hydrogen atoms; A methyl group, a fluoro group, a chloro group or a trifluoromethyl group, and particularly preferably R ²¹ and R ²² are a methyl group or a trifluoromethyl group.

In the formula (9), from the viewpoint of easily improving various chemical and physical properties of the transparent resin film, and from the viewpoint of easily increasing transparency and maintaining the transparency, R ³⁵ to R ⁴⁰ are A hydrogen atom or an alkyl group having 1 to 6 carbon atoms is preferred, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is more preferred, and a hydrogen atom is even more preferred. Here, the hydrogen atoms contained in R ³⁵ to R ⁴⁰ may be independently substituted with halogen atoms, and examples of the halogen atoms include fluorine, chlorine, bromine and iodine atoms. . Examples of the alkyl group having 1 to 6 carbon atoms and the aryl group having 6 to 12 carbon atoms in R ³⁵ to R ⁴⁰ include those exemplified above.

In one preferred embodiment of the present invention, formula (5) is represented by formula (5') and formula (9) is represented by formula (9'):

で表される。すなわち、複数のＹの少なくとも一部は、式（５’）及び／又は式（９’）で表される。この場合、透明樹脂フィルムの物理的特性を高めやすい。さらに、式（５）が式（５’）で表される場合、フッ素元素を含有する骨格によりポリイミド系樹脂の溶媒への溶解性を高め、該樹脂を含有するワニスの保管安定性を向上しやすいと共に、該ワニスの粘度を低減しやすく、透明樹脂フィルムの加工性を向上しやすい。また、フッ素元素を含有する骨格により、透明樹脂フィルムの光学特性を向上しやすい。

is represented by That is, at least some of the plurality of Y's are represented by formula (5') and/or formula (9'). In this case, it is easy to improve the physical properties of the transparent resin film. Furthermore, when the formula (5) is represented by the formula (5'), the skeleton containing the fluorine element increases the solubility of the polyimide resin in a solvent, and improves the storage stability of the varnish containing the resin. In addition, the viscosity of the varnish can be easily reduced, and the processability of the transparent resin film can be easily improved. In addition, the skeleton containing elemental fluorine makes it easy to improve the optical properties of the transparent resin film.

In a preferred embodiment of the present invention, preferably 50 mol% or more, more preferably 60 mol% or more, and still more preferably 70 mol% or more of Y in the polyimide resin is represented by formula (5), particularly formula (5 '). When Y within the above range in the polyimide resin is represented by formula (5), especially formula (5′), the skeleton containing fluorine element increases the solubility of the polyimide resin in a solvent, and contains the resin It is easy to reduce the viscosity of the varnish to be applied, and it is easy to improve the workability of the transparent resin film. In addition, the skeleton containing elemental fluorine makes it easy to improve the optical properties of the transparent resin film. Preferably, 100 mol % or less of Y in the polyimide resin is represented by formula (5), particularly formula (5′). Y in the polyimide resin may be formula (5), especially formula (5'). The ratio of the structural unit of Y represented by the formula (5) in the polyimide resin can be measured using, for example, ¹ H-NMR, or can be calculated from the charging ratio of raw materials.

In a preferred embodiment of the present invention, the plurality of structural units represented by formula (1) include, in addition to the structural units in which Y is represented by formula (5), the structure in which Y is represented by formula (9) Preferably, it further contains a unit. When Y further contains a structural unit represented by formula (9), various physical properties of the transparent resin film are likely to be further improved.

The polyimide resin may contain a structural unit represented by the formula (30) and / or a structural unit represented by the formula (31), and may be represented by the formula (1) and optionally the formula (2) In addition to the structural unit represented by the formula (30), it may contain a structural unit represented by the formula (30) and/or the structural unit represented by the formula (31).

In formula (30), Y ¹ is a tetravalent organic group, preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. Y ¹ is represented by formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) and a group represented by the formula (29), a group in which a hydrogen atom in the group represented by the formulas (20) to (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, and A tetravalent chain hydrocarbon group having 6 or less carbon atoms is exemplified. In one embodiment of the present invention, the polyimide-based resin may contain multiple types of Y ¹ , and the multiple types of Y ¹ may be the same or different.

In formula (31), Y ² is a trivalent organic group, preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. As Y ² , the above formulas (20), (21), (22), (23), (24), (25), (26), (27), (28) ), a group in which one of the bonds of the group represented by formula (29) is replaced with a hydrogen atom, and a trivalent chain hydrocarbon group having 6 or less carbon atoms. In one embodiment of the present invention, the polyimide-based resin may contain multiple types of ^Y2 , and the multiple types of ^Y2 may be the same or different.

In formulas (30) and (31), X ¹ and X ² are each independently a divalent organic group, preferably a hydrocarbon group or a hydrocarbon group in which a hydrogen atom in the organic group is substituted with fluorine. is an organic group optionally substituted with As X ¹ and X ² , the above formula (10), formula (11), formula (12), formula (13), formula (14), formula (15), formula (16), formula (17) and a group represented by the formula (18); a group in which hydrogen atoms in the groups represented by the formulas (10) to (18) are substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and A chain hydrocarbon group having 6 or less carbon atoms is exemplified.

In one embodiment of the present invention, the polyimide resin is a structural unit represented by formula (1) and / or formula (2), and optionally a structure represented by formula (30) and / or formula (31) Consists of units. Further, from the viewpoint of easily improving the optical properties and various physical properties of the transparent resin film, the ratio of the structural units represented by the formulas (1) and (2) in the polyimide resin is Preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, based on all structural units represented by formula (2) and optionally formulas (30) and (31) is. In the polyimide resin, the ratio of the structural units represented by formulas (1) and (2) is represented by formulas (1) and (2), and optionally formula (30) and / or formula (31) is usually 100% or less based on all structural units represented by The above ratio can be measured, for example, using ¹ H-NMR, or can be calculated from the charging ratio of raw materials.

In one embodiment of the present invention, the content of the polyimide resin and / or polyamide resin in the resin composition is preferably 10 parts by mass or more, more preferably It is 30 parts by mass or more, more preferably 50 parts by mass or more, preferably 99.5 parts by mass or less, more preferably 99 parts by mass or less, and more preferably 95 parts by mass or less. When the content of the polyimide-based resin and/or the polyamide-based resin is within the above range, various chemical properties and physical properties of the resin layer included in the laminate are likely to be improved.

The weight-average molecular weight (hereinafter sometimes referred to as Mw) of the polyimide resin and the polyamide resin is converted to standard polystyrene from the viewpoint of easily improving various chemical and physical properties of the transparent resin film, preferably It is 150,000 or more, more preferably 200,000 or more, even more preferably 230,000 or more, still more preferably 250,000 or more. In addition, the Mw of the polyimide resin and the polyamide resin is preferably 1,000,000 or less from the viewpoint of easily improving the solubility of the resin in the solvent and easily improving the stretchability and workability of the transparent resin film. , more preferably 800,000 or less, still more preferably 700,000 or less, even more preferably 500,000 or less. Mw can be determined, for example, by performing gel permeation chromatography (hereinafter sometimes referred to as GPC) measurement and converting to standard polystyrene, and may be calculated, for example, by the method described in Examples.

In the polyamideimide resin, the content of the structural unit represented by formula (2) is preferably 0.1 mol or more, more preferably 0.5, per 1 mol of the structural unit represented by formula (1). mol or more, more preferably 1.0 mol or more, still more preferably 1.5 mol or more, preferably 6.0 mol or less, more preferably 5.0 mol or less, still more preferably 4.5 mol or less be. When the content of the structural unit represented by formula (2) is at least the above lower limit, various physical properties of the transparent resin film are likely to be enhanced. Further, when the content of the structural unit represented by formula (2) is equal to or less than the above upper limit, thickening due to hydrogen bonding between amide bonds in formula (2) is suppressed, and the resin layer is formed. It is easy to improve the handleability of the resin composition.

In a preferred embodiment of the present invention, the polyimide-based resin and/or polyamide-based resin contained in the resin layer may contain halogen atoms such as fluorine atoms, which can be introduced by, for example, fluorine-containing substituents. When the polyimide-based resin and/or the polyamide-based resin contain halogen atoms, the YI value of the laminate including the resin layer is likely to be reduced. When the YI value of the laminate containing the resin layer is low, it becomes easier to improve the transparency and visibility of the laminate. A halogen atom is preferably a fluorine atom. Preferred fluorine-containing substituents for allowing the polyimide resin to contain fluorine atoms include, for example, a fluoro group and a trifluoromethyl group.

Polyimide-based resins and polyamide-based resins are preferably fluorine-containing resins. In this case, the content of halogen atoms (preferably fluorine atoms) in the resin is preferably 1 to 50% by mass, more preferably 5 to 50% by mass, based on the mass of the polyimide resin and the polyamide resin, respectively. , more preferably 10 to 50% by mass, still more preferably 10 to 30% by mass.
When the halogen atom content is at least the above lower limit, the YI value of the laminate having the resin layer (B) is further reduced, and the transparency and visibility are more likely to be improved. When the content of halogen atoms is equal to or less than the above upper limit, synthesis becomes easier.
Further, when the halogen atom is a fluorine atom, the content of the fluorine atom is preferably 1 to 50% by mass, more preferably 5 to 50% by mass, more preferably 5 to 50% by mass, based on the mass of the polyimide resin and the polyamide resin. is 10 to 50% by weight, more preferably 10 to 30% by weight.

The imidization rate of the polyimide resin and the polyamideimide resin is preferably 90% or more, more preferably 93% or more, still more preferably 96% or more, and usually 100% or less. From the viewpoint of easily improving the optical properties of the transparent resin film, the imidization ratio is preferably within the above range. The imidization ratio indicates the ratio of the molar amount of imide bonds in the polyimide resin to twice the molar amount of the structural units derived from the tetracarboxylic acid compound in the polyimide resin. In the case where the polyimide resin contains a tricarboxylic acid compound, a value twice the molar amount of the structural units derived from the tetracarboxylic acid compound in the polyimide resin, and the molar amount of the structural units derived from the tricarboxylic acid compound It shows the ratio of the molar amount of imide bonds in the polyimide resin to the total of . Also, the imidization rate can be determined by IR method, NMR method, or the like.

You may use a commercial item as a polyimide-type resin and a polyamide-type resin. Examples of commercially available polyimide resins include KPI-MX300F manufactured by Kawamura Sangyo Co., Ltd., and the like.

In the present invention, the resin composition may contain a polyamide-based resin. The polyamide-based resin according to this embodiment is a polymer mainly composed of repeating structural units represented by formula (2). Preferred examples and specific examples of Z in formula (2) in the polyamide-based resin are the same as those of Z in the polyimide-based resin. The polyamide-based resin may contain two or more types of repeating structural units represented by the formula (2) in which Z is different.

In the present invention, the terminal structure of the polyimide-based resin and the polyamide-based resin is not particularly limited, but in one aspect of the present invention, the polyimide-based resin and the polyamide-based resin preferably have a terminal carboxylic acid derived from a tetracarboxylic acid compound. and/or an amino group derived from a diamine compound and/or a carboxylic acid group derived from a dicarboxylic acid compound. In one aspect of the present invention, the polyimide-based resin and the polyamide-based resin preferably do not have terminal hydroxyl groups. In general, the --OH group contained in the carboxylic acid group (--C(=O)--OH) is not called a hydroxyl group. Therefore, in a preferred embodiment of the present invention, even when the polyimide-based resin and the polyamide-based resin do not have terminal hydroxyl groups, the resins may have terminal carboxylic acid groups.

<Resin manufacturing method>
Polyimide resins and polyimide precursor resins, for example, can be produced using a tetracarboxylic acid compound and a diamine compound as main raw materials, and polyamideimide resins and polyamideimide precursor resins are, for example, tetracarboxylic acid compounds, dicarboxylic acid compounds and diamine compounds. can be produced using as main raw materials, and the polyamide resin can be produced using, for example, a diamine compound and a dicarboxylic acid compound as main raw materials. Here, the dicarboxylic acid compound preferably contains at least the compound represented by formula (3″).

［式（３”）中、Ｒ^１～Ｒ^８は、互いに独立に、水素原子、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、又は炭素数６～１２のアリール基を表し、Ｒ^１～Ｒ^８に含まれる水素原子は、互いに独立に、ハロゲン原子で置換されていてもよく、
Ａは、単結合、－Ｏ－、－ＣＨ_２－、－ＣＨ_２－ＣＨ_２－、－ＣＨ（ＣＨ_３）－、－Ｃ（ＣＨ_３）_２－、－Ｃ（ＣＦ_３）_２－、－ＳＯ_２－、－Ｓ－、－ＣＯ－又は－Ｎ（Ｒ^９）－を表し、
Ｒ^９は水素原子、ハロゲン原子で置換されていてもよい炭素数１～１２の１価の炭化水素基を表し、
ｍは０～４の整数であり、
Ｒ^３１及びＲ^３２は、互いに独立に、ヒドロキシル基、メトキシ基、エトキシ基、ｎ－プロポキシ基、イソプロポキシ基、ｎ－ブトキシ基、イソブトキシ基、ｓｅｃ－ブトキシ基、ｔｅｒｔ－ブトキシ基又は塩素原子を表す。］

[In formula (3″), R ¹ to R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. and hydrogen atoms contained in R ¹ to R ⁸ may be independently substituted with halogen atoms,
A is a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, - SO ₂ -, -S-, -CO- or -N(R ⁹ )-,
R ⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom;
m is an integer from 0 to 4,
R ³¹ and R ³² are each independently a hydroxyl group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group or a chlorine atom; show. ]

In one preferred embodiment of the present invention, the dicarboxylic acid compound is a compound represented by formula (3″), wherein m is 0. As the dicarboxylic acid compound, a compound represented by formula (3″), where m is 0 It is more preferred to use compounds of the formula (3″), wherein A is an oxygen atom, in addition to the compounds of R ³¹ and A compound of the formula (3″), wherein R ³² is a chlorine atom. A diisocyanate compound may be used instead of the diamine compound.

Diamine compounds used in making resins include, for example, aliphatic diamines, aromatic diamines, and mixtures thereof. In this embodiment, the term "aromatic diamine" refers to a diamine in which an amino group is directly bonded to an aromatic ring, and part of its structure may contain an aliphatic group or other substituents. This aromatic ring may be a single ring or a condensed ring, and examples include, but are not limited to, benzene ring, naphthalene ring, anthracene ring, and fluorene ring. Among these, a benzene ring is preferably exemplified. The term "aliphatic diamine" refers to a diamine in which an amino group is directly bonded to an aliphatic group, and part of its structure may contain an aromatic ring or other substituents.

Aliphatic diamines include, for example, acyclic aliphatic diamines such as hexamethylenediamine, as well as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, norbornanediamine and 4,4' - Cycloaliphatic diamines such as diaminodicyclohexylmethane. These can be used alone or in combination of two or more.

Examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene and 2,6-diaminonaphthalene. of, an aromatic diamine having one aromatic ring, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'- Diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4 -aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl] Propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2′-dimethylbenzidine, 2,2′-bis(trifluoromethyl)-4,4′-diaminodiphenyl (TFMB and 4,4′-bis(4-aminophenoxy)biphenyl, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene , 9,9-bis(4-amino-3-chlorophenyl)fluorene, 9,9-bis(4-amino-3-fluorophenyl)fluorene, and other aromatic diamines having two or more aromatic rings. These can be used singly or in combination of two or more.

Aromatic diamines are preferably 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 3 ,3′-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2 , 2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2′-dimethylbenzidine, TFMB, 4,4′- bis(4-aminophenoxy)biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone, 1, 4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine , TFMB, 4,4′-bis(4-aminophenoxy)biphenyl. These can be used singly or in combination of two or more.

Among the above diamine compounds, one or more selected from the group consisting of aromatic diamines having a biphenyl structure is used from the viewpoint of high surface hardness, high transparency, high flexibility, high bending resistance and low coloration of the resin layer. It is preferable to use selected from the group consisting of TFMB, 2,2′-dimethylbenzidine, 2,2′-bis(trifluoromethyl)benzidine, 4,4′-bis(4-aminophenoxy)biphenyl and 4,4′-diaminodiphenyl ether It is more preferable to use one or more, and it is even more preferable to use TFMB.

Examples of the tetracarboxylic acid compound used in the production of the resin include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic dianhydrides; and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydrides. be done. A tetracarboxylic acid compound may be used independently and may be used in combination of 2 or more type. The tetracarboxylic acid compound may be a dianhydride or a tetracarboxylic acid compound analog such as an acid chloride compound.

Specific examples of aromatic tetracarboxylic dianhydrides include non-condensed polycyclic aromatic tetracarboxylic dianhydrides, monocyclic aromatic tetracarboxylic dianhydrides and condensed polycyclic aromatic tetracarboxylic dianhydrides. Carboxylic acid dianhydrides are mentioned. Non-fused polycyclic aromatic tetracarboxylic dianhydrides include, for example, 4,4′-oxydiphthalic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 2,2 ',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (sometimes referred to as BPDA), 2,2',3,3 '-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2, 2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid Dianhydride (sometimes referred to as 6FDA), 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride , 1,2-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylenedioxy)diphthalic dianhydride, 4,4'-(m-phenylenedioxy)diphthalic An acid dianhydride is mentioned. Further, the monocyclic aromatic tetracarboxylic dianhydrides include, for example, 1,2,4,5-benzenetetracarboxylic dianhydrides, and condensed polycyclic aromatic tetracarboxylic dianhydrides. Examples include 2,3,6,7-naphthalenetetracarboxylic dianhydride.

Among these, preferably 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride anhydride, BPDA, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis(3, 4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 6FDA, 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,2-bis(3,4- dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-di carboxyphenyl)methane dianhydride, 4,4′-(p-phenylenedioxy)diphthalic dianhydride and 4,4′-(m-phenylenedioxy)diphthalic dianhydride, more preferably 4,4′-oxydiphthalic dianhydride, BPDA, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, 6FDA, bis(3,4-dicarboxyphenyl)methane dianhydride and 4, 4'-(p-phenylenedioxy)diphthalic dianhydride. These can be used singly or in combination of two or more.

Aliphatic tetracarboxylic dianhydrides include cyclic or acyclic aliphatic tetracarboxylic dianhydrides. The cyclic aliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having an alicyclic hydrocarbon structure, and specific examples thereof include 1,2,4,5-cyclohexanetetracarboxylic dianhydride. 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cycloalkanetetracarboxylic dianhydride such as 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo[2.2 .2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl-3,3′,4,4′-tetracarboxylic dianhydride and positional isomers thereof be done. These can be used alone or in combination of two or more. Specific examples of the acyclic aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and 1,2,3,4-pentanetetracarboxylic dianhydride. and these can be used alone or in combination of two or more. A cyclic aliphatic tetracarboxylic dianhydride and an acyclic aliphatic tetracarboxylic dianhydride may also be used in combination.

Among the above tetracarboxylic dianhydrides, 4,4′-oxydiphthalic dianhydride, 3,3 are preferred from the viewpoint of high surface hardness, high transparency, high flexibility, high bending resistance and low coloring of the resin layer. ',4,4'-benzophenonetetracarboxylic dianhydride, BPDA, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid Dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride and 6FDA and mixtures thereof are preferred, BPDA and 6FDA and mixtures thereof are more preferred, 6FDA and BPDA are more preferred .

Terephthalic acid, isophthalic acid, 4,4'-oxybisbenzoic acid, or acid chloride compounds thereof are preferably used as the dicarboxylic acid compound used in the production of the resin. In addition to terephthalic acid, isophthalic acid, 4,4'-oxybisbenzoic acid or their acid chloride compounds, other dicarboxylic acid compounds may be used. Other dicarboxylic acid compounds include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, their analogous acid chloride compounds, acid anhydrides, and the like, and two or more of them may be used in combination. Specific examples include isophthalic acid; naphthalenedicarboxylic acid; 4,4′-biphenyldicarboxylic acid; 3,3′-biphenyldicarboxylic acid; Compounds linked by a single bond, —CH ₂ —, —C(CH ₃ ) ₂ —, —C(CF ₃ ) ₂ —, —SO ₂ — or a phenylene group, and acid chloride compounds thereof can be mentioned. As a specific example, 4,4'-oxybis(benzoyl chloride), terephthaloyl chloride or isophthaloyl chloride is preferable, and 4,4'-oxybis(benzoyl chloride) and terephthaloyl chloride can be used in combination. More preferred.

The polyimide-based resin is obtained by further reacting the tetracarboxylic acid compound, tetracarboxylic acid, tricarboxylic acid, anhydrides and derivatives thereof in addition to the tetracarboxylic acid compound to the extent that the various physical properties of the transparent resin film are not impaired. may

Tetracarboxylic acids include water adducts of the above tetracarboxylic acid compound anhydrides.

Examples of tricarboxylic acid compounds include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, their analogous acid chloride compounds, acid anhydrides, and the like, and two or more of them may be used in combination. Specific examples include 1,2,4-benzenetricarboxylic anhydride; 1,3,5-benzenetricarboxylic anhydride; 2,3,6-naphthalenetricarboxylic acid-2,3-anhydride; phthalic acid A compound in which an anhydride and benzoic acid are linked by a single bond, —O—, —CH ₂ —, —C(CH ₃ ) ₂ —, —C(CF ₃ ) ₂ —, —SO ₂ — or a phenylene group mentioned.

In the production of the resin, the amount of the diamine compound, the tetracarboxylic acid compound and/or the dicarboxylic acid compound to be used can be appropriately selected according to the ratio of each constituent unit of the desired polyimide resin.

In the production of the resin, the reaction temperature of the diamine compound, tetracarboxylic acid compound and dicarboxylic acid compound is not particularly limited, but is, for example, 5 to 350°C, preferably 20 to 200°C, more preferably 25 to 100°C. The reaction time is also not particularly limited, but is, for example, about 30 minutes to 10 hours. If desired, the reaction may be conducted under conditions of inert atmosphere or reduced pressure. In a preferred embodiment, the reaction is carried out under normal pressure and/or inert gas atmosphere with stirring. Also, the reaction is preferably carried out in a solvent inert to the reaction. The solvent is not particularly limited as long as it does not affect the reaction, but examples include water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, Alcohol solvents such as 2-butoxyethanol and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone (hereinafter sometimes referred to as GBL), γ-valerolactone, propylene glycol methyl ester solvents such as ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; Aromatic hydrocarbon solvents such as toluene and xylene; Nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran and dimethoxyethane; Chlorine-containing solvents such as chloroform and chlorobenzene; Amide solvents such as acetamide (hereinafter sometimes referred to as DMAc) and N,N-dimethylformamide (hereinafter sometimes referred to as DMF); sulfur-containing solvents such as dimethylsulfone, dimethylsulfoxide and sulfolane; carbonate-based solvents such as ethylene carbonate and propylene carbonate; and combinations thereof. Among these, amide solvents can be preferably used from the viewpoint of solubility.

In the imidization step in the production of polyimide resin, imidization can be performed in the presence of an imidization catalyst. Examples of imidization catalysts include aliphatic amines such as tripropylamine, dibutylpropylamine, ethyldibutylamine; N-ethylpiperidine, N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydro Alicyclic amines (monocyclic) such as azepine; azabicyclo[2.2.1]heptane, azabicyclo[3.2.1]octane, azabicyclo[2.2.2]octane, and azabicyclo[3.2. 2] Alicyclic amines (polycyclic) such as nonane; and pyridine, 2-methylpyridine (2-picoline), 3-methylpyridine (3-picoline), 4-methylpyridine (4-picoline), 2- ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2,4-dimethylpyridine, 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and Aromatic amines such as isoquinoline can be mentioned. Moreover, from the viewpoint of facilitating the imidization reaction, it is preferable to use an acid anhydride together with the imidization catalyst. Acid anhydrides include conventional acid anhydrides used in imidization reactions, and specific examples thereof include aliphatic acid anhydrides such as acetic anhydride, propionic anhydride and butyric anhydride, and aromatic acid anhydrides such as phthalic acid. and acid anhydrides.

Polyimide resins and polyamide resins are isolated (separated and purified) by conventional methods such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, and other separation means, or a combination of these separation means. In a preferred embodiment, a large amount of alcohol such as methanol is added to the reaction solution containing the transparent polyamideimide resin to precipitate the resin, which can then be isolated by concentration, filtration, drying, and the like.

<Filler with an average primary particle size of 1 to 50 nm>
The resin composition contains a filler having an average primary particle size of 1 to 50 nm. Examples of materials constituting the filler having an average primary particle size of 1 to 50 nm include glass fibers such as milled glass fiber and chopped glass fiber, potassium titanate whisker, alumina whisker, aluminum borate whisker, silicon carbide whisker, and silicon nitride whisker. Metallic or non-metallic whiskers, glass beads, hollow glass spheres, glass powder, silica, alumina, potassium titanate, barium sulfate, calcium sulfite, silica sand, quartz, titanium oxide, zinc oxide, iron oxide graphite, molybdenum , silica alumina fiber, alumina fiber, carbon fiber, white carbon, etc., preferably silica, alumina, titanium oxide, and more preferably silica from the viewpoint of easily improving adhesion to the glass layer. . These may be used alone or in combination of two or more.
The filler preferably has —OH groups on its surface. Since such a filler has a strong interaction with the silane coupling agent, the filler contained in the resin layer bonds with the glass through the silane coupling agent, thereby further enhancing the adhesion between the resin layer and the glass. is considered possible. Fillers having —OH groups on the surface preferably include silica, alumina, titanium oxide, and fillers surface-coated with silica, alumina and/or titanium oxide, more preferably with silica and silica. and fillers.

Silica may be a silica sol in which silica is dispersed in an organic solvent or the like, or silica fine particle powder produced by a gas phase method may be used. A silica sol is preferred.
Silica having Si—OH groups on its surface is particularly preferred. Since such silica has a strong interaction with the silane coupling agent, the silica contained in the resin layer bonds with the glass via the silane coupling agent, thereby further enhancing the adhesion between the resin layer and the glass. It is considered possible. Such fillers include silica and silica surface-coated fillers.

If necessary, the filler may be surface-treated, and examples of the surface treatment agent include reactive coupling agents such as silane coupling agents, titanate coupling agents, and borane coupling agents. Lubricants such as ring agents, higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, and fluorocarbon-based surfactants can be used.

In the present invention, the average primary particle size of the filler may be 1 to 50 nm, preferably 5 to 45 nm, more preferably 10 to 40 nm. When the average primary particle size of the filler is within the above range, the affinity with the inorganic glass (A) tends to be high, and blending with the polyimide resin tends to be facilitated.

The average primary particle size of the filler can be measured by the measurement method described in Japanese Patent No. 6447831. Specifically, the specific surface area is measured by the BET 1-point method using a nitrogen adsorption method specific surface area meter, and the formula: average primary It can be obtained from particle diameter (nm) = 2,720/specific surface area.

The content of the filler is preferably 0.1 to 60 parts by mass, more preferably 1 to 50 parts by mass, still more preferably 2 to 45 parts by mass, and even more preferably 100 parts by mass of the solid content of the resin composition. is 4 to 40 parts by mass. When the content of the filler is within the above range, the adhesion between the resin layer (B) and the inorganic glass (A) tends to be good, and the flexibility of the front plate for display device tends to be good. be.

<Silane coupling agent>
The resin composition further contains a silane coupling agent having at least one group selected from the group consisting of isocyanate groups, blocked isocyanate groups, epoxy groups, glycidyl groups and oxetanyl groups. As the silane coupling agent, a silane coupling agent having an isocyanate group and/or a blocked isocyanate group (hereinafter referred to as an "isocyanate-based silane coupling agent") is used from the viewpoint of easily improving the adhesion between the inorganic glass layer and the resin layer. ) is preferable, and a silane coupling agent having an isocyanate group is more preferable.

Examples of isocyanate-based silane coupling agents include isocyanate-based silane coupling agents such as 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, and Shin-Etsu Silicone X-12-1308ES.

Silane coupling agents having an epoxy group, a glycidyl group or an oxetanyl group include, for example, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2 -(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, [(3- ethyl-3-oxetanyl)methoxy]propyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, [(3-ethyl-3-oxetanyl)methoxy]propyltriethoxysilane and the like.

In the resin composition, the content of the silane coupling agent is such that the adhesion between the resin layer (B) and the inorganic glass (A) is easily improved, and the optical properties of the obtained laminate are easily improved. From the viewpoint, it is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of at least one resin selected from the group consisting of polyimide resins and polyamide resins, and 0.2 to 5 parts by mass. is more preferred.

The resin composition described above can be used as a composition for forming a glass protective film. The present invention also provides a composition for forming a glass protective film comprising the resin composition described above. The composition for forming a glass protective film provided by the present invention is not a composition for forming a peelable protective film used for the purpose of temporarily protecting the surface of the glass, is a composition for forming a non-peelable protective film.

<Additive>
The resin composition may further contain additives in addition to the filler. Additives include, for example, antioxidants, release agents, light stabilizers, bluing agents, flame retardants, lubricants and leveling agents.

In the present invention, when the resin composition contains an additive, the content of the additive is preferably 20% by mass or less, more preferably 10% by mass or less, preferably 0% by mass, based on the solid content of the resin composition. 001% by mass or more.

In the present invention, the resin composition is, for example, a reaction liquid of a polyimide resin obtained by reacting selected from the tetracarboxylic acid compound, the diamine and the other raw materials, and adding fillers and, if necessary, additives. It is prepared by mixing, adding a solvent if necessary, and mixing and stirring. A resin composition may be called a resin varnish.

<Solvent>
The resin composition may further contain a solvent. Examples of the solvent include organic solvents, and a solvent capable of dissolving or dispersing the polyimide resin or polyamide resin can be appropriately selected. From the viewpoint of the solubility, coating properties, drying properties, etc. of polyimide resins and polyamide resins, the boiling point of the organic solvent is preferably 120 to 300° C., more preferably 120 to 270° C., still more preferably 120 to 250. °C, particularly preferably 120 to 230°C. Specific examples of such organic solvents include amide solvents such as DMF, DMAc and N-methylpyrrolidone; lactone solvents such as GBL and γ-valerolactone; ketone solvents such as cyclohexanone, cyclopentanone and methyl ethyl ketone. Solvents; acetic acid ester solvents such as butyl acetate and amyl acetate; sulfur-containing solvents such as dimethylsulfone, dimethylsulfoxide and sulfolane; and carbonate solvents such as ethylene carbonate and propylene carbonate. Among them, DMAc (boiling point: 165°C), GBL (boiling point: 204°C), N-methylpyrrolidone (boiling point: 202°C), butyl acetate (boiling point: 126°C ), cyclopentanone (boiling point: 131° C.) and amyl acetate (boiling point: 149° C.) are preferred. As the solvent, one type may be used alone, or two or more types may be used in combination. When two or more kinds of solvents are used, it is preferable to select the kinds of solvents so that the boiling point of the solvent having the highest boiling point among the solvents to be used falls within the above range.

The amount of the solvent in the resin composition may be selected so that the resin composition has a viscosity that allows handling, and is not particularly limited, but is preferably 50 to 95 parts by mass with respect to 100 parts by mass of the resin composition. , more preferably 70 to 95 parts by mass, more preferably 80 to 95 parts by mass. Also, the solid content concentration of the resin composition is preferably 5 to 50% by mass, more preferably 5 to 30% by mass, and still more preferably 5 to 20% by mass.

The resin layer (B) in the present invention can be obtained, for example, by applying the above resin composition onto the inorganic glass (A), drying it, and reducing the amount of solvent in the resin composition.

The thickness of the resin layer (B) may be appropriately determined according to the application of the front plate for display devices, etc., and is usually 10 to 500 μm, preferably 15 to 200 μm, more preferably 20 to 130 μm.

The resin layer (B) may contain a solvent, the content of which is preferably 5% by mass or less, more preferably 3% by mass or less, relative to 100% by mass of the resin composition constituting the resin layer It is preferably 1% by mass or less, and more preferably 0.8% by mass or less. When the content of the solvent is within the above range, the adhesion between the resin layer (B) and the inorganic glass (A) tends to be good.

In one preferred embodiment of the present invention, the laminate of the present invention may comprise a resin layer (B) laminated directly to the glass layer on at least one side, preferably both sides, of the glass layer. In another embodiment, the laminate of the present invention comprises a resin layer (B) directly laminated on one side of the glass layer, and another polyimide resin film on the opposite side of the glass layer. may have. The other polyimide resin film may be directly laminated on the glass layer, or may be bonded via an adhesive layer, an adhesive layer, or the like. With the configuration as described above, the function of preventing scattering when the glass is broken can be further enhanced. From the viewpoint of further enhancing the anti-scattering function, it is particularly preferable that the polyimide resin layer is directly laminated on both sides of the glass, and at least one of the polyimide resin layers is the resin layer (B) in the present invention. It is particularly more preferable that both of the polyimide resin layers are the resin layer (B) in the present invention.

(Other layers)
As long as the laminate of the present invention includes the above-mentioned glass layer and a resin layer directly laminated on the glass layer, the other layer constitution is not limited at all, and the glass layer, the resin layer, and other additional layers or a laminate composed of the glass layer and the resin layer without other layers. Examples of other layers include functional layers, and specific examples include ultraviolet absorbing layers, hard coat layers, primer layers, gas barrier layers, adhesive layers, hue adjusting layers, and refractive index adjusting layers. A functional layer can be used individually or in combination of 2 or more types.

The ultraviolet absorbing layer is a layer having a function of absorbing ultraviolet rays. It is composed of dispersed ultraviolet absorbers.

A hard coat layer may be provided on at least one surface of the laminate of the present invention, preferably on the surface of the resin layer (B) opposite to the surface in contact with the glass layer. The thickness of the hard coat layer is not particularly limited, and may be, for example, 2 to 100 μm. When the thickness of the hard coat layer is within the above range, it is easy to increase the impact resistance. The hard coat layer can be formed by curing a hard coat composition containing a reactive material capable of forming a crosslinked structure by irradiation with active energy rays or application of thermal energy, preferably by irradiation with active energy rays. Active energy rays are defined as energy rays that can generate active species by decomposing compounds that generate active species, and include visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays and electron rays. etc., preferably ultraviolet rays. The hard coat composition contains at least one polymer of a radically polymerizable compound and a cationic polymerizable compound.

The radically polymerizable compound is a compound having a radically polymerizable group. The radically polymerizable group possessed by the radically polymerizable compound may be a functional group capable of causing a radical polymerization reaction, and examples thereof include a group containing a carbon-carbon unsaturated double bond, and specifically, a vinyl group. , (meth)acryloyl group, and the like. When the radically polymerizable compound has two or more radically polymerizable groups, these radically polymerizable groups may be the same or different. The number of radically polymerizable groups in one molecule of the radically polymerizable compound is preferably 2 or more from the viewpoint of improving the hardness of the hard coat layer. The radically polymerizable compound, from the viewpoint of high reactivity, preferably includes a compound having a (meth)acryloyl group, specifically 2 to 6 (meth)acryloyl groups in one molecule. Compounds called polyfunctional acrylate monomers, epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates with several (meth) acryloyl groups in the molecule with a molecular weight of several hundred Thousands of oligomers are listed, preferably one or more selected from epoxy (meth)acrylates, urethane (meth)acrylates and polyester (meth)acrylates.

The cationically polymerizable compound is a compound having a cationically polymerizable group such as an epoxy group, an oxetanyl group, or a group having a vinyl ether bond. The number of cationically polymerizable groups 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 hard coat layer.
As the cationically polymerizable compound, among others, a compound having at least one of an epoxy group and an oxetanyl group as a cationically polymerizable group is preferable. A group having a cyclic ether bond such as an epoxy group or an oxetanyl group is preferable from the viewpoint of less shrinkage due to polymerization reaction. Among the groups having a cyclic ether bond, compounds having an epoxy group are readily available in various structures, do not adversely affect the durability of the resulting hard coat layer, and are compatible with radically polymerizable compounds. has the advantage of being easy to control. In addition, among the groups having a cyclic ether bond, the oxetanyl group tends to have a higher degree of polymerization than the epoxy group, is low in toxicity, and has a network formation speed obtained from the cationically polymerizable compound of the resulting hard coat layer. There are advantages such as the formation of an independent network without leaving unreacted monomers in the film even in a region mixed with the radically polymerizable compound.
Examples of cationic polymerizable compounds having an epoxy group include polyglycidyl ethers of polyhydric alcohols having an alicyclic ring, or compounds containing cyclohexene rings or cyclopentene rings, which are treated with a suitable oxidizing agent such as hydrogen peroxide or peracid. Alicyclic epoxy resin obtained by epoxidation; polyglycidyl ether of aliphatic polyhydric alcohol or its alkylene oxide adduct, polyglycidyl ester of aliphatic long-chain polybasic acid, homopolymer of glycidyl (meth)acrylate, Aliphatic epoxy resins such as copolymers; bisphenols such as bisphenol A, bisphenol F and hydrogenated bisphenol A, or derivatives such as alkylene oxide adducts and caprolactone adducts thereof, and glycidyl ethers produced by reaction with epichlorohydrin, and glycidyl ether type epoxy resins derived from bisphenols such as novolac epoxy resins.

The hard coat composition may further include a polymerization initiator. Examples of polymerization initiators include radical polymerization initiators, cationic polymerization initiators, radical and cationic polymerization initiators, and the like, which are appropriately selected and used. These polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate radicals or cations to promote radical polymerization and cationic polymerization.
Any radical polymerization initiator may be used as long as it can release a substance that initiates radical polymerization by at least one of active energy ray irradiation and heating. Examples of thermal radical polymerization initiators include organic peroxides such as hydrogen peroxide and perbenzoic acid, and azo compounds such as azobisisobutyronitrile.
As active energy ray radical polymerization initiators, Type 1 type radical polymerization initiators that generate radicals by decomposition of molecules and Type 2 type radical polymerization initiators that generate radicals by hydrogen abstraction reaction in coexistence with tertiary amines are used. Yes, they are used alone or in combination.
The cationic polymerization initiator should be capable of releasing a substance that initiates cationic polymerization by at least one of active energy ray irradiation and heating. As cationic polymerization initiators, aromatic iodonium salts, aromatic sulfonium salts, cyclopentadienyl iron (II) complexes and the like can be used. These can initiate cationic polymerization by either or both of active energy ray irradiation and heating depending on the difference in structure.

The polymerization initiator may be included in an amount of preferably 0.1 to 10% by weight with respect to 100% by weight of the hard coat composition. When the content of the polymerization initiator is within the above range, curing can be sufficiently progressed, and the mechanical properties and adhesion of the finally obtained coating film can be in a good range, and Poor adhesion, cracking, and curling due to cure shrinkage tend to be less likely to occur.

The hard coat composition may further include one or more selected from the group consisting of solvents and additives.
The solvent is capable of dissolving or dispersing the polymerizable compound and the polymerization initiator, and any solvent known as a solvent for hard coat compositions in the technical field does not impede the effects of the present invention. range can be used.
The additives may further include inorganic particles, leveling agents, stabilizers, surfactants, antistatic agents, lubricants, antifouling agents, and the like.

The adhesive layer is a layer having an adhesive function, and has a function of adhering the laminate of the present invention to another member. Commonly known materials can be used as the material for forming the adhesive layer. For example, a thermosetting resin composition or a photocurable resin composition can be used. In this case, the resin composition can be polymerized and cured by supplying energy afterward.

The adhesive layer may be a layer that adheres to an object by pressing, which is called a pressure sensitive adhesive (PSA). The pressure-sensitive adhesive may be a pressure-sensitive adhesive that is "a substance that has adhesiveness at room temperature and adheres to the adherend with light pressure" (JIS K6800), and "a specific component is a protective coating (microcapsule) It may be a capsule-type adhesive that is "adhesive that can maintain stability until the coating is destroyed by appropriate means (pressure, heat, etc.)" (JIS K6800).

The hue-adjusting layer is a layer having a hue-adjusting function, and is a layer capable of adjusting the desired hue of the laminate of the present invention. A hue adjustment layer is a layer containing resin and a coloring agent, for example. Examples of the coloring agent include inorganic pigments such as titanium oxide, zinc oxide, red iron oxide, titanium oxide-based calcined pigments, ultramarine blue, cobalt aluminate, and carbon black; azo-based compounds, quinacridone-based compounds, anthraquinone-based compounds, Organic pigments such as perylene compounds, isoindolinone compounds, phthalocyanine compounds, quinophthalone compounds, threne compounds, and diketopyrrolopyrrole compounds; extender pigments such as barium sulfate and calcium carbonate; and basic dyes, Dyes such as acid dyes and mordant dyes can be mentioned.

The refractive index adjusting layer is a layer having a function of adjusting the refractive index. For example, it has a refractive index different from that of the resin layer and the glass layer included in the laminate of the present invention, and imparts a predetermined refractive index to the laminate. It is a layer that can The refractive index adjusting layer may be, for example, a resin layer containing an appropriately selected resin and optionally a pigment, or may be a metal thin film. Pigments that adjust the refractive index include, for example, silicon oxide, aluminum oxide, antimony oxide, tin oxide, titanium oxide, zirconium oxide, and tantalum oxide. The average primary particle size of the pigment may be 0.1 μm or less. By setting the average primary particle size of the pigment to 0.1 μm or less, it is possible to prevent diffused reflection of light passing through the refractive index adjusting layer and to prevent a decrease in transparency. Examples of metals used for the refractive index adjusting layer include metals such as titanium oxide, tantalum oxide, zirconium oxide, zinc oxide, tin oxide, silicon oxide, indium oxide, titanium oxynitride, titanium nitride, silicon oxynitride, and silicon nitride. Oxides or metal nitrides may be mentioned.

The laminate of the present invention preferably has high light transmittance. A method for measuring the total light transmittance is specifically described in Examples.

In the laminate of the present invention, it is preferable that its transparency is high. % or less. When the total light transmittance is in the above range, the transparency is high and it is easy to use for display devices. The total light transmittance can be measured using a haze computer according to JIS K7361-1:1997, for example. The total light transmittance may be the total light transmittance in the thickness range of the laminate described later.

In the laminate of the present invention, the haze is preferably small, specifically preferably 2.0% or less, more preferably 1.0% or less, still more preferably 0.5% or less, still more preferably It is 0.3% or less, and usually 0 or more. When the haze is in the above range, the transparency is high and it is easy to use for display devices. Haze can be measured using a haze computer in accordance with JIS K7136:2000.

In the laminate of the present invention, the YI value is preferably low. More specifically, the YI value is preferably 5.0 or less, more preferably 4.0 or less, still more preferably 3.0 or less, and even more preferably 3.0 or less. It is preferably 2.0 or less, particularly preferably 1.8 or less, even more preferably 1.6 or less, particularly preferably 1.4 or less, even more preferably 1.3 or less, and usually 0 or more. When the YI value is within the above range, the visibility tends to be good. In accordance with JIS K 7373: 2006, YI measures transmittance for light of 300 to 800 nm using an ultraviolet-visible-near-infrared spectrophotometer, obtains tristimulus values (X, Y, Z), and obtains YI. = 100 x (1.2769X-1.0592Z)/Y.

The thickness of the laminate of the present invention may be appropriately adjusted depending on the application, but is preferably 25 μm or more, more preferably 30 μm or more, still more preferably 50 μm or more, preferably 600 μm or less, more preferably 500 μm or less. , and more preferably 400 μm or less. From the viewpoint of providing a flexible laminate, the thickness of the laminate is preferably 300 μm or less, more preferably 280 μm or less, even more preferably 250 μm or less, and even more preferably 230 μm or less. The thickness of the laminate can be measured with a film thickness meter or the like, for example, by the method described in Examples.

In the laminate of the present invention, the peel strength between the resin layer and the glass layer is preferably 4.0 N/inch or more, more preferably 4.5 N/inch or more, from the viewpoint of easily obtaining sufficient adhesion between these layers. inch or more, more preferably 5.0 N/inch or more. Also, the peel strength is preferably 50 N/inch or less, more preferably 30 N/inch or less, still more preferably 20 N/inch or less. The peel strength between the resin layer and the glass layer is measured, for example, using a precision universal testing machine, Autograph Series (manufactured by Shimadzu Corporation). It is the peel strength when peeled at 180°, and can be specifically measured by the method described in Examples using a measurement sample having a resin layer with a width of 25 mm, for example.

In a preferred embodiment of the present invention, the laminate of the present invention has excellent bending resistance. More preferably 130,000 times or more, still more preferably 150,000 times or more. The bending endurance number of the laminate can be obtained, for example, by using a surface state no-load U-shaped expansion tester (“DMLHB-FS” (trade name) manufactured by Yuasa System Co., Ltd.).

[Method for manufacturing laminate]
According to the method for producing a laminate of the present invention, a laminate having an inorganic glass layer and a resin layer (B) made of a specific resin composition directly laminated on at least one surface of the inorganic glass can be obtained. Although not particularly limited as long as it is possible, for example the following steps:
(a) at least one resin selected from the group consisting of polyimide resins and polyamide resins, a filler having an average primary particle size of 1 to 50 nm, an isocyanate group, a blocked isocyanate group, an epoxy group, a glycidyl group and an oxetanyl group A resin composition preparation step of preparing a resin composition containing a silane coupling agent having at least one group selected from the group consisting of, if necessary, a solvent, etc.
(b) a coating step of applying a resin composition to inorganic glass (A) to form a coating film; and (c) a resin layer forming step of drying the coating film to form a resin layer (B). It may be a manufacturing method.

In the resin composition preparation step, for example, at least one resin selected from the group consisting of polyimide resins and polyamide resins is dissolved in a solvent, and a filler having an average primary particle size of 1 to 50 nm and a silane coupling agent, If necessary, it is prepared by adding an additive such as the ultraviolet absorber and stirring and mixing. When silica particles are used as the filler, silica sol obtained by substituting a silica sol dispersion containing silica particles with a solvent capable of dissolving the resin may be added to the resin. Solvents that can be included in the resin composition are as described above.

In the coating step, a coating film is formed by directly coating the resin composition on the inorganic glass by a known coating method. Examples of known coating methods include wire bar coating, reverse coating, roll coating such as gravure coating, die coating, comma coating, lip coating, spin coating, screen coating, fountain coating, and dipping. method, spray method, casting method, and the like.

The laminate of the present invention can be produced by drying the coating film in the resin layer forming step. Drying of the coating film tends to lower the YI value, and when a flexible glass layer and / or a chemically strengthened glass layer is used as the glass layer, the properties of these glass layers, preferably suppressing deterioration of bending resistance. From the point of view of ease of curing, it is preferable to carry out at a temperature of 250° C. or less, preferably 50 to 250° C. If desired, drying of the coating may be carried out under conditions of inert atmosphere or reduced pressure. In addition, since the obtained resin layer contains components other than the solvent contained in the resin layer, the content of each component contained in the resin layer is the same as the content of each component contained in the resin composition. equal to the content based on the solids concentration of Also, a small amount of the solvent may remain in the resin layer. The amount of the solvent contained in the resin layer is preferably 1.5% or less, more preferably 1.2% or less, still more preferably 1.1% or less, still more preferably 1.5% or less, based on the mass of the resin layer. 0% or less. The lower limit of the amount of solvent is preferably 0% or more, more preferably 0.02% or more, still more preferably 0.1% or more, and even more preferably 0.3% or more.

The step of drying the coating film in the resin layer forming step may be carried out by carrying out main drying after carrying out preliminary drying. The pre-drying temperature is preferably 50° C. or higher, more preferably 80° C. or higher, still more preferably 100° C. or higher, and preferably 200° C. or lower, more preferably 150° C. or lower, from the viewpoint of maintaining the quality of the resin layer surface. be. The pre-drying time may be appropriately selected according to the type of solvent contained in the resin composition, the pre-drying temperature, etc., preferably 5 to 150 minutes, more preferably 10 to 120 minutes, still more preferably 20 to 60 minutes. is. Pre-drying may be performed under an inert atmosphere or under reduced pressure conditions, if necessary.

The main drying temperature is preferably 150° C. or higher, more preferably 180° C. or higher, and still more preferably 200° C. or higher, from the viewpoint of removing the solvent in the resin layer and improving the adhesion between the resin layer and the glass layer. From the viewpoint of easily reducing the YI value, and when using a flexible glass layer and / or a chemically strengthened glass layer as the glass layer, the characteristics of these glass layers, preferably from the viewpoint of easily suppressing a decrease in bending resistance, It is preferably 250° C. or lower, more preferably 240° C. or lower, still more preferably 230° C. or lower, and even more preferably 220° C. or lower. The main drying temperature is higher than the pre-drying temperature, preferably 30° C. or higher, more preferably 40° C. or higher, further preferably 50° C. or higher than the pre-drying temperature. The main drying time may be appropriately selected according to the solid content concentration of the resin coating film after pre-drying, and is preferably 1 to 120 minutes, more preferably 5 to 80 minutes, and still more preferably 10 to 40 minutes. . This drying may be performed under an inert atmosphere or under reduced pressure conditions, if necessary. Conventionally, when forming a resin layer containing a polyimide-based resin or a polyamide-based resin, it is dried at a temperature exceeding 250° C., preferably 270° C., so that the resulting resin layer tends to be colored and has a low transparency. there were. On the other hand, the resin composition in the present invention has a specific filler and a silane coupling agent as described above, so even if it is dried at a relatively low temperature, it has excellent adhesion to the glass layer, and furthermore, all light transmission A resin layer having a high modulus and a low YI value can be formed.

In one embodiment of the present invention, the laminate of the present invention may have a peelable protective film on at least one side (single side or both sides). For example, in the case of the laminate of the present invention having a functional layer on one side of the film of the present invention, the protective film may be laminated on the resin layer side surface or the glass layer side surface of the laminate of the present invention. It may be laminated on both surfaces of the laminate of the invention. The protective film is a film for temporarily protecting the surface of the laminate of the present invention, and is not particularly limited as long as it is a peelable film capable of protecting the surface of the laminate. Examples of protective films include polyester resin films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resin films such as polyethylene and polypropylene films; acrylic resin films; It is preferably selected from the group consisting of a terephthalate resin film and an acrylic resin film. When the laminate of the present invention has two protective films, each protective film may be the same or different.

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

In a preferred embodiment of the present invention, the laminate of the present invention is suitably used for display devices, for example, window films (also referred to as "front panels"), especially flexible displays such as rollable displays and foldable displays. It is useful as the front plate of the device. That is, the laminate of the present invention is preferably an optical laminate, more preferably a laminate for a front plate of a display device, and even more preferably a laminate for a front plate of a flexible display device. The invention also provides a laminate of the invention, which is a laminate for a front panel of a flexible display, and a front panel of a flexible display comprising the laminate of the invention. The front plate has a function of protecting the display element of the flexible display device. Note that the flexible display device is a display device that is used with an operation such as repeatedly bending or winding the image display device. A front panel of a flexible display device that is used with such repeated bending operations is required to have high bending resistance, particularly high folding resistance. Also, the front plate is required to have high visibility. Compared to the film for the substrate of the image display device used inside the image display device, the front panel of the image display device, particularly the laminate for the front plate of the flexible display device, is required to have high visibility. , high bending resistance is required. The laminate of the present invention preferably satisfies the number of times of flex resistance as described above from the viewpoint of facilitating improvement in flex resistance, particularly folding resistance, when used as a front plate of a flexible display device. Display devices include televisions, smart phones, mobile phones, car navigation systems, tablet PCs, portable game machines, electronic paper, indicators, bulletin boards, watches, and wearable devices such as smart watches. Flexible displays include display devices having flexible properties, such as televisions, smartphones, mobile phones, and smart watches. Flexible display devices include all image display devices having flexible characteristics, such as rollable displays and foldable displays as described above. A rollable display is an image display device in which an image display portion including a front plate is wound into a roll, and the image display portion is pulled out to be used in a flat or curved surface. It is an image display device in which an operation such as picking up is performed each time it is used. A foldable display is an image display device in which an image display portion including a front panel is folded and used in a state where the image display portion is opened to form a flat or curved surface, and operations such as folding are used. It is an image display device that is performed every time. An image display device in which operations such as winding and bending are repeatedly performed is called a flexible image display device. The front panel of the flexible display is positioned on the viewing side above the flexible functional layer. This front plate has the function of protecting the flexible functional layer.

Display devices include televisions, smart phones, mobile phones, car navigation systems, tablet PCs, portable game machines, electronic paper, indicators, bulletin boards, watches, and wearable devices such as smart watches. Flexible display devices include all display devices with flexible properties.

[Flexible display device]
The invention also provides a display comprising the laminate of the invention as a window film. The flexible display device includes a flexible display device front panel and an organic EL display panel. The flexible display device front panel is arranged on the viewing side of the organic EL display panel, and is configured to be foldable. The front panel for a flexible display device may contain the front panel for a display device of the present invention, a circularly polarizing plate, and a touch sensor. It is preferable that the front plate, the circularly polarizing plate, the touch sensor or the display device front plate, the touch sensor, and the circularly polarizing plate are laminated in this order. When the circularly polarizing plate is present on the viewing side of the touch sensor, the pattern of the touch sensor becomes less visible and the visibility of the displayed image is improved, which is preferable. Each member can be laminated using an adhesive, a pressure-sensitive adhesive, or the like. Further, a light shielding pattern may be formed on at least one surface of any one of the display device front panel, the circularly polarizing plate, and the touch sensor.

[Polarizer]
The display device of the present invention may further comprise a polarizing plate, preferably a circularly polarizing plate. A circularly polarizing plate is a functional layer having a function of transmitting only a right-handed circularly polarized light component or a left-handed circularly polarized light component by laminating a λ/4 retardation plate on a linearly polarizing plate. For example, by converting external light into right-handed circularly polarized light and blocking left-handed circularly polarized light reflected by the organic EL panel, only the organic EL light emitting component is transmitted, thereby suppressing the influence of reflected light and creating an image. used to make it easier to see In order to achieve the circular polarization function, the absorption axis of the linear polarizer and the slow axis of the λ/4 retardation plate should theoretically be 45°, but practically 45±10°. The linear polarizing plate and the λ/4 retardation plate do not necessarily have to be laminated adjacent to each other as long as the relationship between the absorption axis and the slow axis satisfies the above range. Although it is preferable to achieve perfect circular polarization at all wavelengths, it is not always necessary in practice, so the circularly polarizing plate in the present invention also includes an elliptically polarizing plate. It is also preferable to further laminate a λ/4 retardation film on the viewing side of the linear polarizing plate to circularly polarize the emitted light, thereby improving the visibility when wearing polarized sunglasses.

[Touch sensor]
The flexible display device of the present invention preferably further includes a touch sensor as described above. A touch sensor is used as an input means. As the touch sensor, there are various types such as a resistive film type, a surface acoustic wave type, an infrared type, an electromagnetic induction type, and a capacitance type, and the capacitive type is preferable.
A capacitive touch sensor is divided into an active area and a non-active area located outside the active area. The active area is an area corresponding to the area (display part) where the screen is displayed on the display panel, and is an area where a user's touch is sensed. display area). The touch sensor includes a flexible substrate, sensing patterns formed in an active region of the substrate, and formed in a non-active region of the substrate, and is connected to an external driving circuit through the sensing patterns and pad portions. can include each sensing line for As the flexible substrate, the same material as the transparent substrate of the window film can be used.

[Adhesion layer]
Each layer forming the laminate for a flexible display device (window film, circular polarizing plate, touch sensor) and film members constituting each layer (linear polarizing plate, λ / 4 retardation plate, etc.) can be bonded with an adhesive. can. Examples of the adhesive include water-based adhesives, organic solvent-based adhesives, solvent-free adhesives, solid adhesives, solvent-vaporizing adhesives, water-based solvent-vaporizing adhesives, moisture-curable adhesives, heat-curable adhesives, and anaerobic adhesives. Commonly used adhesives such as curing type, active energy ray curing type adhesive, curing agent mixed type adhesive, hot melt type adhesive, pressure sensitive type adhesive (adhesive), rewetting type adhesive, etc. are used. A water-based solvent volatilization type adhesive, an active energy ray-curable adhesive, and a pressure-sensitive adhesive can be preferably used. The thickness of the adhesive layer can be appropriately adjusted according to the desired adhesive strength and the like, and is preferably 0.01 to 500 μm, more preferably 0.1 to 300 μm. A plurality of adhesive layers are present in the laminate for a flexible display device, and the respective thicknesses and types may be the same or different.

The present invention will be explained in more detail by way of examples. The invention should not be construed as limited to these examples. "%" and "parts" in Examples and Comparative Examples are "% by mass" and "parts by mass", respectively, unless otherwise specified.

Production Example 1: Preparation of Polyamideimide (1) In a nitrogen gas atmosphere, 50 g (156.13 mmol) of TFMB and 642.07 g of DMAc were added to a 1 L separable flask equipped with a stirring blade, and TFMB was added to DMAc while stirring at room temperature. was dissolved in Next, 20.84 g (46.91 mmol) of 6FDA was added to the flask and stirred at room temperature for 3 hours. After that, 9.23 g (31.27 mmol) of 4,4′-oxybis(benzoyl chloride) and then 15.87 g (78.18 mmol) of terephthaloyl chloride were added to the flask and stirred at room temperature for 1 hour. Next, 9.89 g (106.17 mmol) of 4-methylpyridine and 14.37 g (140.73 mmol) of acetic anhydride were added to the flask, stirred at room temperature for 30 minutes, and then heated to 70°C using an oil bath. After further stirring for 3 hours, a reaction solution was obtained. The resulting reaction solution was cooled to room temperature and thrown into a large amount of methanol in the form of a thread, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and washed with methanol. Next, the precipitate was dried under reduced pressure at 100° C. to obtain polyamideimide (1). The Mw of the obtained polyamideimide (1) was 420,000 as a result of measuring by the Mw measuring method described below.

<Measurement of Mw>
The Mw of the polyamideimide resin was measured using GPC. The method of preparing the measurement sample and the measurement conditions are as follows.
(1) Sample Preparation Method 20 mg of resin was weighed out, and 10 mL of DMF (10 mmol/L lithium bromide added) was added to completely dissolve the resin. This solution was filtered through a chromatodisk with a pore size of 0.45 μm to obtain a sample solution.
(2) Measurement conditions Apparatus: HLC-8020GPC
Column: guard column + TSKgel α-M (length 300 mm, inner diameter 7.8 mm) × 2 + α-2500 (length 300 mm, inner diameter 7.8 mm) × 1 Eluent: DMF (10 mmol / L lithium bromide added)
Flow rate: 1.0 mL/min Detector: RI detector Column temperature: 40°C
Injection volume: 100 μL
Molecular weight standard: standard polystyrene

Production Example 2: Preparation of silica sol (1) As a filler, a methanol dispersion of amorphous silica sol having a BET diameter (average primary particle diameter measured by the BET method) of 27 nm prepared by a sol-gel method was used as a raw material, and was added to GBL. GBL substituted silica sols were prepared by solvent substitution. The obtained sol was filtered through a membrane filter with an opening of 10 μm to obtain GBL-substituted silica sol (1).

The solid content of the silica sol and the average primary particle size of silica in the silica sol were measured by the following methods.
<Measurement of silica solid content in silica sol>
6.0 g of silica sol (1) described in Production Example 2 was weighed into an aluminum cup, and heat-treated at 200° C. for 1 hour in the air using a dryer (DKN-302, manufactured by Yamato Scientific Co., Ltd.). , a solid was obtained and weighed. The ratio of the weighed value to 6.0 g was calculated and used as the silica content in the silica sol. The silica content in silica sol (1) was 30% by mass. Silica sol is used as a filler in the present invention.

<Measurement of average primary particle size of silica in silica sol>
In the same manner as the measurement method described in Japanese Patent No. 6447831, the silica sol is brought into contact with a hydrogen-type strongly acidic cation exchange resin to remove the base adsorbed on the surface of the silica sol, and then dried in a vacuum dryer at 80°C. to obtain silica gel. The resulting silica gel was pulverized in a mortar and then dried at 180° C. for 3 hours to obtain dry silica powder. The specific surface area (m ² /g) of this powder was measured by a nitrogen adsorption method, and the average primary particle size of silica in the silica sol was obtained from the obtained specific surface area by the following formula. The specific surface area was measured using a nitrogen adsorption specific surface area meter (Monosorb MS-16 manufactured by Yuasa Ionics Co., Ltd.) according to the BET one-point method (He/N ₂ mixed gas). In the examples described later, the amount of powder was 0.3 g, and the preliminary degassing conditions were 105° C. for 10 minutes under atmospheric pressure.
Formula: Average primary particle size (nm) = 2,720/specific surface area (m ² /g)

Example 1
(Preparation of resin composition (1))
Using the polyamideimide (1) obtained in Production Example 1 and the GBL-substituted silica sol (1) obtained in Production Example 2, the polyamideimide (1) and silica particles were added to GBL so that the composition ratio of the solid content was 60. :40 to obtain a mixture. 3 phr of 3-isocyanatopropyltriethoxysilane (silane coupling agent (1)) (3 parts by weight with respect to 100 parts by weight of polyamideimide (1)) was added thereto, and the resulting mixture was dissolved. It was filtered through a membrane filter with an opening of 3 μm to obtain a resin composition (1). Resin composition (1) had a solid concentration of 11.0% by mass and a viscosity of 35,000 cps at 25°C.

<Viscosity of resin composition>
The viscosity of the resin composition was measured in accordance with JIS K 8803:2011 using a Brookfield E-type viscometer DV-II+Pro. The measurement temperature was 25°C.

(Measurement of contact angle of inorganic glass)
The contact angle of inorganic glass was measured according to the static drop method described in JIS R 3257:1999.

(Production of laminate (1))
The resulting resin composition (1) was applied to an inorganic glass (“EAGLE GLASS XG” manufactured by Corning, thickness 0.5 mm), and a coating film of the resin composition (1) was formed by casting. The coating film is heated at 100° C. for 14 minutes, then at 120° C. for 15 minutes, then at 90° C. for 15 minutes, then at 80° C. for 15 minutes, then at 220° C. for 40 minutes, Finally, the laminate was slowly cooled to 30°C at a rate of 5°C/min to obtain a laminate (1) having a resin layer on the inorganic glass. The amount of residual solvent in the resin layer was 0.7% by mass.

The adhesion between the inorganic glass layer and the resin layer and the thickness of the resin layer of the obtained laminate were measured as follows. Also, the amount of residual solvent in the resin layer was measured as described below.

<Adhesion evaluation: 180° peeling test>
A schematic diagram of the measurement sample used for the 180° peel test is shown in FIG. Using the laminates obtained in Examples and Comparative Examples, the polyimide resin layer on the glass was cut with a width of 25 mm, the resin layer other than the portion having a width of 25 mm was removed, and the glass layer as shown in FIG. 2 and a resin layer 1 having a width of 25 mm. The ends of the strip-shaped resin layer with a width of 25 mm were slightly peeled off, and a tape 4 was attached for sandwiching between chucks of a peel tester. A 10 mm length range from one end of the tape 4 in the longitudinal direction was defined as the attachment end. A tape 3 was also attached to the surface of the glass layer on the side opposite to the resin layer in order to prevent cracking of the glass. Using the measurement sample, the end of the peeling tape on the gripping side opposite to the mounting end of the laminate was gripped with a chuck of a peeling device, and the angle (peeling angle) with respect to the plane direction of the laminate was 180 °. As such, the resin layer 1 was peeled in the peeling direction 5 under the following measurement conditions, and the 180° peel strength was measured.
Apparatus: Autograph AGS-100NX (manufactured by Shimadzu Corporation)
Sample width: 25mm
Peeling speed: 50mm/min

<Thickness of resin layer>
The thickness of the resin layer in the laminates obtained in Examples and Comparative Examples was calculated from the difference between the thickness of the laminate and the initial thickness of the inorganic glass using Digital Micro MH-15M manufactured by Nikon Corporation. bottom.

<Residual solvent amount>
Using TG-DTA (EXSTAR6000 TG/DTA6300 manufactured by SII Co., Ltd.), the laminates described in Examples and Comparative Examples were heated from 30 ° C. to 120 ° C., held at 120 ° C. for 5 minutes, and then heated to 5 ° C. The temperature was raised to 400° C. at a temperature elevation rate of /min. From the mass of the laminate immediately after being held at 120° C. for 5 minutes, the ratio of the mass reduction of the laminate at 250° C. was calculated as the content of the solvent and defined as the residual solvent amount.

Table 1 shows the content of the filler contained in the resin layer and the type and content of the silane coupling agent in Examples and Comparative Examples. In all the examples and comparative examples, the contact angle of the inorganic glass was 50°, the silica sol species contained in the resin layer was silica sol (1), and the average primary particle size of the filler was 27 nm. Further, the total light transmittance, which is an optical characteristic required for the front plate for display device, was measured as described below. Table 1 shows the results. Table 1 also shows the adhesion between the inorganic glass and the resin layer and the thickness of the resin layer.

<Total light transmittance measurement>
In accordance with JIS K 7105: 1981, a haze computer (fully automatic direct reading HGM-2DP manufactured by Suga Test Instruments Co., Ltd.) was used to measure the total light transmittance (Tt%). set the surface.

Example 2
(Preparation of resin composition (2))
A resin composition was prepared in the same manner as in Example 1, except that the composition ratio of polyamideimide (1) and silica particles in the GBL solvent was mixed so that the mass ratio of the solid content was 80:20, A resin composition (2) was obtained. Resin composition (2) had a solid concentration of 10.0% by mass and a viscosity of 37,000 cps at 25°C.

(Production of laminate (2))
A laminate (2) was obtained in the same manner as in Example 1, except that the resin composition (2) was used instead of the resin composition (1). The amount of residual solvent in the resin layer was 0.7% by mass.

Comparative example 1
Resin composition (3) was prepared in the same manner as in Example 1 except that 3-isocyanatopropyltriethoxysilane was not added, and resin composition (3) was used instead of resin composition (1). A laminate was obtained in the same manner as in Example 1 except for the above. The viscosity of Resin Composition (3) at 25° C. was 38,000 cps, and the amount of residual solvent in the resin layer was 0.7 mass %.

Comparative example 2
A resin composition (4) was prepared in the same manner as in Example 1 except that 3-aminopropylethoxysilane (silane coupling agent (2)) was added instead of 3-isocyanatopropyltriethoxysilane, An attempt was made to obtain a laminate in the same manner as in Example 1 except that the resin composition (4) was used instead of the resin composition (1), but the resin composition gelled and could not be coated. . The silane coupling agent (2) does not have at least one group selected from the group consisting of isocyanate groups, blocked isocyanate groups, epoxy groups, glycidyl groups and oxetanyl groups.

<Example 3: Preparation of laminate>
The resin composition (1) obtained in the same manner as in Example 1 was applied to chemically strengthened glass having flexibility (thickness: 50 μm) using an applicator, dried at 50° C. for 30 minutes, and then dried at 140° C. for 15 minutes. do. Furthermore, the temperature was raised from room temperature to 220 ° C. over 40 minutes, maintained at 220 ° C. for 20 minutes and dried to form a layer with a thickness of 30 μm, so that the chemically strengthened glass layer and the glass layer were directly laminated. A laminate including a resin layer is obtained. The laminate exhibits adhesion strength (180° peel strength) and total light transmittance comparable to those of the laminate obtained in Example 1. Moreover, in a bending resistance test with a bending radius of 2 mm, which is measured in a bending resistance test described later, the number of times of bending resistance is 100,000 times or more.

<Bend resistance test>
Flexibility tests were performed at a temperature of 25°C. The optical laminates obtained in Examples and Comparative Examples were subjected to a surface condition no-load U-shaped expansion/contraction tester ("DMLHB-FS" (trade name) manufactured by Yuasa System Equipment Co., Ltd.) so that they could be bent with the resin layer facing inward. ), the distance between the facing front plates is 4.0 mm (bending radius 2 mm), and the operation of bending 180° and stretching is repeated at a speed of 30 times per minute, The number of bends when the optical layered body breaks is evaluated.

From the results in Table 1, the laminate satisfying the requirements of claim 1 had excellent adhesion between the inorganic glass and the resin layer, had excellent optical properties, and was suitable for the front panel of a display device.

The laminate of the present invention can be used for the front plate of the display screen in various display devices, particularly flexible display devices.

Claims (15)

A laminate having an inorganic glass (A) and a resin layer (B) directly laminated on at least one surface of the inorganic glass (A),
The resin layer (B) includes at least one resin selected from the group consisting of polyimide resins and polyamide resins, a filler having an average primary particle size of 1 to 50 nm, and a silane cup having an isocyanate group and/or a blocked isocyanate group . formed from a resin composition containing a ring agent,
laminate. The laminate according to claim 1, wherein the resin is a fluorine atom-containing resin. 2. The method according to claim 1, wherein the surface of the inorganic glass (A) with which the resin layer (B) is in contact has a contact angle of 80° or less measured according to the sessile drop method described in JIS R 3257:1999. laminate. 2. The laminate according to claim 1, wherein the content of the resin is 50 to 99 parts by mass with respect to 100 parts by mass of the solid content of the resin composition. 2. The laminate according to claim 1, wherein the content of the filler having an average primary particle diameter of 1 to 50 nm is 0.1 to 60 parts by mass with respect to 100 parts by mass of the solid content of the resin composition. 2. The laminate according to claim 1, wherein said filler having an average primary particle size of 1 to 50 nm is composed of silica. The content of the silane coupling agent is 0.1 to 10 parts by mass with respect to 100 parts by mass of at least one resin selected from the group consisting of polyimide resins and polyamide resins, according to claim 1 laminate. The laminate according to claim 1, which has a total light transmittance of 85% or more. The laminate according to claim 1, having a YI value of 5.0 or less. A laminate having an inorganic glass (A) and a resin layer (B) directly laminated on at least one surface of the inorganic glass (A),
The resin layer (B) includes at least one resin selected from the group consisting of polyimide resins and polyamide resins, a filler having an average primary particle size of 1 to 50 nm, an isocyanate group, a blocked isocyanate group, an epoxy group, and glycidyl. formed from a resin composition containing a silane coupling agent having at least one group selected from the group consisting of a group and an oxetanyl group,
A laminate in which a hard coat layer is further laminated on the surface of the resin layer (B) opposite to the surface in contact with the glass layer . A laminate having an inorganic glass (A) and a resin layer (B) directly laminated on at least one surface of the inorganic glass (A),
The resin layer (B) includes at least one resin selected from the group consisting of polyimide resins and polyamide resins, a filler having an average primary particle size of 1 to 50 nm, an isocyanate group, a blocked isocyanate group, an epoxy group, and glycidyl. formed from a resin composition containing a silane coupling agent having at least one group selected from the group consisting of a group and an oxetanyl group,
A laminate that is used as a window film for a display device. A display device comprising the laminate according to any one of claims 1 to 11 . 13. The display device of Claim 12 , further comprising a polarizing plate. 13. The display device of Claim 12 , further comprising a touch sensor. 13. The display of claim 12 , wherein the display is a flexible display.

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