JP2021075363A - Manufacturing method for dried film roll - Google Patents

Abstract

To reduce cracking in a film generated at a held portion of the film in a tenter drawing device.SOLUTION: A manufacturing method for dried film roll using a tenter drawing device includes: a process of unwinding a film from a raw material film roll; a process of conveying the unwound film; a process of holding both ends of the film parallel to the film conveyance direction for drying; a process of releasing the holding thereof after drying; and a process of winding the film to acquire the dried film roll. The holding section is comprised of a pedestal and a holding part and between the pedestal and the holding part, the film is held. An interval between the pedestal and the holding part is smaller than a thickness of the film and all ends of a film contact surface of the holding part in contact with the film have a curved surface shape.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing a dried film roll using a tenter stretching device that grips, conveys, and stretches both ends of a film.

In recent years, with the thinning, weight reduction, and flexibility of displays of various image display devices, transparent resin films based on polymers such as polyimide and polyamide have been widely used as a material to replace the conventionally used glass. .. The transparent resin film is produced by applying a varnish containing a polymer such as polyimide on a base material, pre-drying the film, and then stretching and drying the obtained pre-dried resin film.

In the stretching and drying steps, the film is carried out using a tenter stretching device that grips, conveys, and stretches both ends of the film, but there is a problem that the film breaks starting from the portion where the film is gripped during stretching with the tenter. To do.

Regarding the gripping tool of the tenter stretching device, Patent Document 1 describes that an R shape is provided on at least one of the upstream side and the downstream side of the gripping member in the film flow direction. It is described that the gripper can be used to prevent the nylon film from being cut during heat treatment.

WO2013 / 080940

An object of the present invention is to reduce cracks generated in a portion where the film is gripped in the tenter stretching apparatus.

The present invention provides the following aspects:
[1] A process of unwinding a film from a raw material film roll,
The process of transporting the unwound film,
The process of grasping and drying both ends of the film parallel to the film transport direction,
A method for producing a dried film roll using a tenter stretching apparatus, which comprises a step of releasing the grip after drying and a step of winding the film to obtain a dried film roll.
The gripping portion comprises a pedestal and a gripping portion, and the film is gripped between the pedestal and the gripping portion.
The distance between the pedestal and the grip portion is thinner than the thickness of the film.
All the ends of the film contact surface of the grip portion that comes into contact with the film have a curved surface shape.
How to make a film roll.
[2] The manufacturing method according to [1], wherein the curved surface shape of the film contact surface end portion of the grip portion has a radius of curvature R of 3 mm ≤ radius of curvature R ≤ 15 mm.
[3] The manufacturing method according to [1] or [2], wherein the curved surface shape of the end portion parallel to the transport direction on the surface of the grip portion in contact with the film is asymmetrical with respect to the vicinity of the center of the curved surface shape. ..
[4] The method according to any one of [1] to [3], wherein the intersection portion at the end portion perpendicular to and parallel to the transport direction of the film on the surface of the grip portion in contact with the film has a curved surface shape. Production method.
[5] The manufacturing method according to any one of [1] to [4], wherein the distance between the pedestal and the grip portion is 1/2 or less of the thickness of the film.
[6] The grip portion is configured to be movable around a fulcrum and can be fixed at the lowest point, the fulcrum exists in a direction opposite to the pedestal with respect to the film, and an end portion of the film is gripped. The manufacturing method according to any one of [1] to [5], which is gripped at the lowest point of the above.
[7] The manufacturing method according to any one of [1] to [6], wherein the fulcrum is fixed to the pedestal.
[8] When the grip portion grips the film at the lowest point at a distance from the pedestal, the position of the end face parallel to the film transport direction of the grip portion is ± The manufacturing method according to any one of [1] to [7], which is located at a position of 1 mm.
[9] The production method according to any one of [1] to [8], wherein the solvent content in the film before drying is 5% by mass or more.
[10] The production method according to any one of [1] to [9], wherein the solvent content in the film after drying is 2% by mass or less.
[11] The production method according to any one of [1] to [10], wherein the dried film has a tensile elastic modulus of 4 GPa or more.
[12] The production method according to any one of [1] to [11], wherein the film is a film containing at least one resin selected from the group consisting of a polyimide resin and a polyamide resin.

By using the method for producing a film roll of the present invention, it is possible to effectively reduce the cracking of the film that occurs when the film is gripped and dried by the tenter stretching device. By reducing cracks, film breakage can also be reduced.

FIG. 1 is a perspective view schematically showing a gripping tool used in the method for producing a film of the present invention. FIG. 2 is a perspective view schematically showing a surface of the grip portion of FIG. 1 in contact with the film. FIG. 3 is a front view of an end portion of a gripper used in the film manufacturing method of the present invention. FIG. 4 is a perspective view schematically showing a state in which the grip portion of the grip tool of FIG. 1 is removed. FIG. 5 is a schematic view showing a state in which grippers are placed at both ends of the film and the film is not gripped in the film manufacturing method of the present invention. FIG. 6 is a schematic view showing a state in which both ends of the film are gripped by a gripper in the film manufacturing method of the present invention. FIG. 7 is a partially enlarged view showing the curved surface shape of the grip portion of the gripper used in the film manufacturing method of the present invention. FIG. 8 is a partially enlarged view showing another curved surface shape of the grip portion of the gripper used in the film manufacturing method of the present invention. FIG. 9 is a diagram schematically showing a tenter stretching apparatus used in the method for producing a film of the present invention. FIG. 10 is a diagram schematically showing a method for producing a dried film roll of the present invention.

The gripping tool used in the method for producing a film roll of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view schematically showing a gripping tool used in the method for producing a film of the present invention, and FIG. 2 is a perspective view schematically showing a surface of the grip portion of FIG. 1 in contact with a film. Is a front view of the end of the gripper. FIG. 4 is a perspective view schematically showing a state in which a part (grip portion) of the grip tool of FIG. 1 is removed. FIG. 5 is a schematic view showing a state in which grippers are placed at both ends of the film and the film is not gripped in the film manufacturing method of the present invention. FIG. 6 is a schematic view showing a state in which both ends of the film are gripped by a gripper. FIG. 7 is a partially enlarged view showing the curved surface shape of the grip portion of the gripper used in the film manufacturing method of the present invention. FIG. 8 is a partially enlarged view showing another curved surface shape of the grip portion of the gripper used in the film manufacturing method of the present invention. FIG. 9 is a diagram schematically showing a tenter stretching device used in the method for producing a film of the present invention, and FIG. 10 is a diagram schematically showing a method for producing a dried film roll of the present invention.

In FIG. 1, the gripper 1 has a pedestal 2 and a grip portion 3, and grips a film 4 (not shown in FIG. 1) between the pedestal 2 and the grip portion 3. The grip portion 3 is movable around a fulcrum 5, and the film 4 is gripped when the film 4 comes into contact between the grip portion 3 and the pedestal 2. The fulcrum 5 is supported between the two fulcrum support portions 6, and the fulcrum support portion 6 is connected and fixed by the pedestal 2 and the connecting portion 7. The fulcrum support portion 6, the connecting portion 7, and the pedestal 2 may be individual members or may be integrated. The fulcrum 5 faces the pedestal 2 via the film 4, and the grip portion 3 moves around the fulcrum 5 to grip the film 4 in the gap formed between the pedestal 2 and the grip portion 3. The state in which the grip portion 3 is at the lowest point and the film 4 is fixed is shown in FIG. 6, and the state in which the grip portion 3 is not at the lowest point and the film 4 is released is shown in FIG. It is shown. As shown in FIG. 6, when the grip portion 3 is at the lowest point and the film 4 is sandwiched between the grip portion 3 and the pedestal 2, the film 4 is gripped most firmly. Even if the grip portion 3 is not at the lowest point, the film is gripped if the film 4 comes into contact with the grip portion 3 and the pedestal 2 as described above.

In the present invention, the grip portion 3 is characterized in that the end of the surface in contact with the film has a curved surface shape, and the distance between the pedestal 2 and the grip portion 3 exceeds 0 μm and is thinner than the thickness of the film 4. It is said.

FIG. 2 is a perspective view in which the surface (hereinafter, referred to as “film contact surface”) 8 of the grip portion 3 in contact with the film 4 is visible, and the end portions 9 and 10 of the film contact surface 8 are here. There are four sides, but all of them have a curved shape at the end in contact with the film. The curved surface shape is shown in a partially enlarged view of the curved surface shape at the end of the film contact surface in FIG. 7, but the curved surface shape is represented by the radius of curvature R, and the radius of curvature R is preferably in the range of 3 mm ≤ radius of curvature R ≤ 15 mm. , Preferably 4 mm ≦ radius of curvature R ≦ 12 mm. All ends 9 and 10 of the film contact surface 8 may all have the same radius of curvature, but may be different. As shown in FIG. 7, the curved surface shape may be a shape represented by one radius of curvature R, but as shown in FIG. 8, the curved surface shape may change from the middle, and in the case of FIG. 8, the curved surface shape may be changed from the middle. It has two curved surface shapes with _{different radii of curvature R 1} to R _{2 with} the vicinity of the center of the curved surface as a boundary. The radius of curvature R ₁ and R ₂ are within the range of the numerical value of the radius of curvature R. The radius of curvature may be three or more radii of curvature, or may be two or more different radii of curvature.

The end 9 of the film contact surface 8 is a side perpendicular to the film transport direction 31, the end 10 is a side parallel to the film transport direction 31, and the intersection 11 between the end 9 and the end 10 is also at an acute angle. It is preferable to have a curved surface shape so as not to become. The curved surface shape of the intersection portion 11 also preferably has a radius of curvature R equivalent to the radius of curvature R.

The gripper 1 of the present invention is installed so that the distance between the pedestal 2 and the grip portion 3 exceeds 0 μm and is thinner than the thickness of the film 4, preferably more than 0 μm and 1/2 or less of the thickness of the film 4. Will be done. As shown in FIG. 3, the interval is an interval formed between the grip portion 3 and the pedestal 2 when the grip portion 3 is at the lowest point with respect to the fulcrum 5, and is represented by 12 in FIG. The film 4 is gripped at this interval 12. Even if the interval 12 is larger than the thickness of the film 4, if the distance when the grip portion 3 and the pedestal 2 are closest to each other is smaller than the thickness of the film 4, the film 4 can be gripped, but the gripping force Is not enough and may induce cracking of the film. When the film 4 is a polyimide resin or a polyamide resin, the interval 12 is preferably 1/30 or more, more preferably 1/20 or more of the film thickness.

The size of the gripping tool 1 varies greatly depending on various factors such as the thickness and width of the film. For example, in terms of the size of the gripping portion 3, the side of the gripping portion 3 parallel to the film transport direction 31 (that is, FIG. 3). The length of the end portion 10) is usually 2 to 10 cm. The length of the side of the grip portion 3 perpendicular to the film transport direction 31 (that is, the end portion 9 in FIG. 3) is usually 1 to 3 cm.

FIG. 3 is a front view of the end surface of the gripping tool 1 of the present invention. As shown in FIGS. 1 and 3, the fulcrum 5 of the grip portion 3 is supported by the fulcrum support portion 6, and the fulcrum support portion 6 is fixed via the pedestal 2 and the connecting portion 7. The fulcrum 5 exists so as to face the pedestal 2 via the film 4 so that the film 4 can be gripped by the grip portion 6.

The pedestal 2 faces each other via the fulcrum 5 and the film 4, but since the film 4 is gripped at a gap 12 formed between the fulcrum 5 and the film 4, the three ends of the pedestal 2 on the side in contact with the film 4 It is preferable that the portion 15 (both the end portion parallel to and the end portion perpendicular to the transport direction of the film) and the corner portion 16 also have a curved surface shape because the film 4 tends to be less cracked. The end portion that does not come into contact with the film, that is, the end portion close to the fulcrum holding portion 6 and the connecting portion 7, does not need to have a curved surface shape.

FIG. 4 shows a perspective view of the gripping tool 1 with the gripping portion 3 removed, and shows a state in which the end portion 15 and the corner portion 16 on the side of the pedestal 2 in contact with the film 4 have a curved surface shape. .. The curved surface shape may have a radius of curvature R'similar to the curved surface shape of the end of the film contact surface of the grip portion 3. The magnitude of the radius of curvature R'may be the same as or different from the radius of curvature R at the end of the film contact surface, and the radius of curvature R'is preferably in the range of 3 mm ≤ radius of curvature R'≤ 15 mm, preferably. 4 mm ≤ radius of curvature R'≤ 12 mm.

The gripping tool 1 used in the film manufacturing method of the present invention is parallel to the film transport direction 31 of the grip portion 6 as shown in FIG. 3 when the grip portion 6 grips the film 4 at a distance of 12 from the pedestal 2. The distance (that is, 22 in FIG. 3) between the end face 20 (the end face on the film side, not the film contact surface 8) and the end face 21 (the end face on the film side) parallel to the film transport direction 31 of the pedestal 2 is ± 1 mm. , It is preferably ± 0.8 mm, more preferably ± 0.7 mm. When the end surface 20 parallel to the film transport direction 31 of the grip portion 6 and the end surface 21 parallel to the film transport direction 31 of the pedestal 2 are substantially flush with each other, the force applied to the film 4 is uniform. It is thought that cracking can be prevented.

When the gripping tool 1 of the present invention is placed on both ends of the film 4 as shown in FIG. 5, and then the gripping portion 3 is moved toward the lowest point, the film 4 is gripped as shown in FIG. FIG. 9 is a diagram schematically showing the tenter stretching device of the present invention. As shown in FIG. 9, the tenter stretching device 41 is a device in which a plurality of gripping tools 1 grip the end portion of the film 4 and continuously move while grasping the end portion of the film 4. The structure is such that the introduction section 42 that introduces the film 4 grips the film, and the delivery section 43 that sends out the film 4 releases the film, and the gripping tools 1 are continuously arranged between them to grip and release the film 4. repeat. As shown in FIG. 9, the gripping tools 1 are arranged in a loop at regular intervals, and the gripping tools released by the sending section 43 come to the introduction section 42 again and are configured to grip again. There is.

FIG. 10 is a diagram schematically showing a method for producing a dried film roll of the present invention. The undried raw material film roll 51 is unwound through the roll 52 and conveyed to the tenter stretching device 41. In the meantime, if the protective film 53 is present, it is peeled off and the protective film is wound into a roll. The tenter stretching device 41 passes through the drying furnace 54 and is dried at the same time as stretching. The drying oven 54 may be of any type and may be a heating and drying oven. Both ends of the film 4 are gripped by the gripping tool at the entrance of the tenter stretching device 41, drying is performed while the film 4 is gripped by the gripping tool in the drying furnace 54, and the film 4 is released from the gripping tool at the outlet of the drying furnace 54. After that, the edges of the film are slit as needed. The dried film 4 is coated with another protective film, if necessary, and used as a dried film roll 55. Normally, the drying oven 54 is divided into several rooms, and in many cases, the air volume and the like can be adjusted individually in each room. In FIG. 10, the drying oven 54 is divided into six rooms.

The film used in the method for producing a film roll of the present invention may be any film, but those suitable for the method for producing a dried film roll of the present invention are transparent resin films, particularly polyimide resins and polyamide-based films. At least one film selected from the group consisting of resins.

In the present specification, the polyimide-based resin represents at least one resin selected from the group consisting of a polyimide resin, a polyamide-imide resin, a polyimide precursor resin, and a polyamide-imide precursor resin. The polyimide resin is a resin containing a repeating structural unit containing an imide group, and the polyamide-imide resin is a resin containing a repeating structural unit containing both an imide group and an amide group. The polyimide precursor resin and the polyamide-imide precursor resin are pre-imidization precursors that give the polyimide resin and the polyamide-imide resin by imidization, respectively, and are also called polyamic acids. Further, in the present specification, the 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-based resin from the viewpoint of the chemical and physical properties of the transparent resin film, and the polyimide-based resin is preferably a polyimide resin or a polyamideimide resin. A polyamideimide resin is preferable.

In a preferred embodiment of the present invention, the polyimide resin and the polyamide resin are preferably aromatic resins from the viewpoint of the chemical properties and physical properties of the transparent resin film. In the present specification, the aromatic resin refers to a resin in which the constituent unit contained in the polyimide resin and the polyamide resin is mainly an aromatic constituent unit.

In one preferred embodiment described above, from the viewpoint of the chemical properties and physical properties of the transparent resin film, the ratio of the structural units derived from the aromatic monomer to the total structural units contained in the polyimide resin and the polyamide resin is determined. It is preferably 60 mol% or more, more preferably 70 mol% or more, still 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 part of an aromatic structure (for example, an aromatic ring), and at least a part of the aromatic structure (for example, an aromatic ring). It is a structural unit included in. Examples of the aromatic monomer include aromatic tetracarboxylic acid compounds, aromatic diamines, and aromatic dicarboxylic acids.

［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）：

［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 one preferred embodiment of the present invention, the polyimide resin is based on the formula (1):

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

[In formula (2), Z and X represent divalent organic groups independently of each other, and * represents a bond]
It is preferable that the polyamide-imide resin has a structural unit represented by. Further, the polyamide resin is preferably a polyamide resin having a structural unit represented by the formula (2). The formulas (1) and (2) will be described below, but the description of the formula (1) relates to both the polyimide resin and the polyamide-imide resin, and the description of the formula (2) describes the polyamide resin and the polyamide-imide resin. Regarding both.

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

［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を抑制（ＹＩ値を低減）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 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 groups). The hydrogen atom in the above is a divalent organic group having 4 to 40 carbon atoms, which may be substituted with a halogen atom (preferably a fluorine atom), and more preferably 1 to 6 carbon atoms. Alkyl group, alkoxy group having 1 to 6 carbon atoms, or aryl group having 6 to 12 carbon atoms (the hydrogen atom in these groups may be substituted with a halogen atom (preferably a fluorine atom)). It may be a divalent organic group having a cyclic structure and having 4 to 40 carbon atoms. Examples of 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 include examples relating to ^{R 3a} and R ^{3b in the formula (3) described later.} The same applies. Examples of the cyclic structure include an alicyclic ring, an aromatic ring, and a heterocyclic structure. As the organic group of Z, the formula (20), the formula (21), the formula (22), the formula (23), the formula (24), the formula (25), the formula (26), the formula (27), the formula (28). And equation (29):

Wherein (20) to Formula (29), ^{W 1} represents 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-, Represents -Ar-C (CH ₃ ) _2- Ar- or -Ar-SO _2- Ar-, where Ar has 6 to 6 carbon atoms in which a hydrogen atom may be substituted with a fluorine atom independently of each other. Represents 20 arylene groups (eg phenylene groups), * represents a bond]
Of the group bonds represented by, a group in which two non-adjacent groups 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. The group having is exemplified. From the viewpoint of easily suppressing the yellowness of the transparent resin film (reducing the YI value), the groups represented by the formulas (20) to (29) and the groups having a thiophene ring skeleton are preferable, and the formula (26), The groups represented by the formulas (28) and (29) are more preferable.

［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。 Examples of the organic group of Z include the formula (20'), the formula (21'), the formula (22'), the formula (23'), the formula (24'), the formula (25'), the formula (26'), and the formula. (27'), equation (28') and equation (29'):

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

［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、ワニスの成膜性を高めやすく、透明樹脂フィルム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（ジカルボン酸化合物に由来する構成単位）、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（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。 When the polyamide-based resin or the polyamide-imide resin has a structural unit in which Z in the formula (2) is represented by any of the above formulas (20') to (29'), particularly in the formula (2). When Z has a structural unit represented by the formula (3') described later, the polyamide-based resin or the polyamide-imide resin is added to the structural unit and has the following formula (d1):

[In the formula (d1), R ²⁴ is a group or a hydrogen atom defining ^{R 3a} in the formula (3) described later ^{, R 25} represents R ²⁴ or −C (= O) − *, and * represents R 24 or −C (= O) − *. Representing a join hand]
It is preferable to further have a carboxylic acid-derived structural unit represented by (1) from the viewpoint of easily improving the film-forming property of the varnish and easily improving the uniformity of the transparent resin film. Specifically, as the structural unit (d1), R ²⁴ and R ²⁵ are both hydrogen atoms (constituent units derived from a dicarboxylic acid compound), and R ²⁴ is a hydrogen atom and R ^25. Examples thereof include a structural unit (a structural unit derived from a tricarboxylic acid compound) representing −C (= O) − *.

［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’）：

［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。 The polyamide-based resin or the polyamide-imide resin may contain a plurality of types of Z as Z in the formula (2), and the plurality of types of Z may be the same as or different from each other. In particular, Z in the formula (2) is preferably the formula (3): from the viewpoint that the chemical and physical properties of the transparent resin film of the present invention can be easily enhanced and the optical characteristics can be easily enhanced.

[In the formula (3), R ^3a and R ^3b 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 R ^3a. And the ^{hydrogen atoms contained in R 3b} may be substituted with halogen atoms independently of each other.
W, independently of one another, 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)} - represents, ^{R 9} is a hydrogen atom, monovalent 1-12 carbon atoms which may be substituted with a halogen atom Represents a hydrocarbon group
s is an integer from 0 to 4, t is an integer from 0 to 4, u is an integer from 0 to 4, and * represents a bond.]
, More preferably equation (3'):

[In equation (3'), R ^3a , R ^3b , s, t, u, W and * are as defined in equation (3)]
It is preferable to have at least a structural unit represented by. In the present specification, the polyamide-based resin or the polyamide-imide resin has a structural unit in which Z in the formula (2) is represented by the formula (3), and the polyamide-based resin or the polyamide-imide resin has the formula (2). ) Has the same meaning as having a structure represented by the formula (3) as Z, and is a structural unit represented by a plurality of formulas (2) contained in the polyamide-based resin or the polyamide-imide resin. Of these, it means that Z in at least a part of the constituent units is represented by the equation (3). This statement also applies to other similar statements.

In formulas (3) and (3 '), W, independently of one another, 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 ) −, which is preferable from the viewpoint of bending resistance of the transparent resin film. Represents -O- or -S-, more preferably -O-.
R ^3a and R ^3b 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, sec-butyl group, tert-butyl group, n-pentyl group and 2-methyl-. Butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl group and the like can be mentioned. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group and a cyclohexyloxy group. Can be mentioned. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xsilyl group, a naphthyl group, a biphenyl group and the like. From the viewpoint of the surface hardness and flexibility of the optical film, R ^3a and R ^3b independently represent an alkyl group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Here, the ^{hydrogen atoms contained in R 3a} and R ^3b may be substituted with halogen atoms independently of each other.
R ⁹ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydrogen atom or a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group and an n-pentyl group. 2-Methyl-butyl group, 3-methylbutyl group, 2-ethyl-propyl group, n-hexyl, n-heptyl group, n-octyl group, tert-octyl group, n-nonyl group, n-decyl group and the like. These may be substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

T and u in the formula (3) and the formula (3') are independently integers of 0 to 4, preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0. is there.

The s in the formula (3) and the formula (3') is an integer in the range of 0 to 4, and when s is in this range, various physical properties of the transparent resin film can be easily improved. , Preferably an integer in the range 0-3, more preferably an integer in the range 0-2, even more preferably 0 or 1, even more preferably 0. The structural unit represented by the formula (3) or the 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 particularly the formula (3) or the formula (3). It is preferable that s in 3') is 0 and u is 0. From the viewpoint of easily improving various chemical properties and physical properties of the transparent resin film, the polyamide-imide resin or the polyamide-based resin preferably contains a structural unit derived from terephthalic acid. The polyamide-imide resin or the polyamide-based resin may contain one or more structural units represented by the formula (3) or the formula (3') in Z. From the viewpoint of improving various chemical properties and physical properties of the transparent resin film and reducing the yellowness (hereinafter, may be abbreviated as YI value), the polyamide-imide resin or the polyamide-based resin is represented by the formula (3) in Z. It is preferable to include two or more kinds of structural units having different values of s in the formula (3'), and two or three kinds of configurations having different values of s in the formula (3) or the formula (3'). It is more preferable to include the unit. In this case, the polyamide-imide resin or the polyamide-based resin is represented by the formula (2) from the viewpoint of easily enhancing various chemical properties and physical properties of the transparent resin film and easily reducing the YI value of the transparent resin film. As Z in the structural unit to be formed, a structure represented by the formula (3) in which s is 0 is contained, and a structure represented by the formula (3) in which s is 1 in addition to the structural unit containing the structure is used. It is more preferable to further contain the containing structural unit. Further, in addition to the structural unit represented by the formula (2) having Z represented by the formula (3) in which s is 0, it is also preferable to further have the structural unit represented by the above formula (d1). ..

で表される構成単位を有する。この場合、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と共に、ＹＩ値を低減しやすい。 In a preferred embodiment of the present invention, the polyamide-imide resin or the polyamide-based resin is a structural unit represented by the formula (3) or the formula (3'), in which s = 0 and u = 0. Has. In a more preferable embodiment of the present invention, the polyamide-imide resin or the polyamide-based resin has a configuration in which s = 0 and u = 0 as a structural unit represented by the formula (3) or the formula (3'). Units and equations (3''):

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

When the polyamideimide resin or the polyamide-based resin has a structural unit represented by the formula (3) or the formula (3'), the ratio thereof is the configuration represented by the formula (1) of the polyamideimide resin or the polyamide-based resin. When the total of the units and the constituent units represented by the 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 ratio of the structural units represented by the formula (3) or the formula (3') is at least the above lower limit, various chemical properties and physical properties of the transparent resin film can be easily enhanced. When the ratio of the structural units represented by the formula (3) or the formula (3') is not more than the above upper limit, the increase in the viscosity of the resin-containing varnish due to the hydrogen bond between the amide bonds derived from the formula (3) is suppressed, and the film is formed. It is easy to improve the workability of.

Further, when the polyamideimide resin or the polyamide-based resin has a structural unit represented by the formula (3) or the formula (3') in which s = 1 to 4, the formula (3) or the formula in which s is 1 to 4 is obtained. As for the ratio of the structural units represented by (3'), the total of the structural units represented by the formula (1) and the structural units represented by the formula (2) of the polyamideimide resin or the polyamide-based resin is 100 mol%. When it is, it is preferably 3 mol% or more, more preferably 5 mol% or more, further preferably 7 mol% or more, still more preferably 9 mol% or more, preferably 90 mol% or less, more preferably 70 mol. % Or less, more preferably 50 mol% or less, even more preferably 30 mol% or less. When the ratio of the structural units represented by the formula (3) or the formula (3') in which s is 1 to 4 is not more than the above lower limit, various chemical properties and physical properties of the transparent resin film can be easily enhanced. .. When the ratio of the structural unit represented by the formula (3) in which s is 1 to 4 is not more than the above upper limit, the hydrogen between amide bonds derived from the structural unit represented by the formula (3) or the formula (3') It is easy to improve the processability of the film by suppressing the increase in viscosity of the resin-containing varnish due to bonding. The ratio of the structural units represented by the formula (1), the formula (2), the formula (3) or the formula (3') ^{can be measured by using, for example, 1 1} H-NMR, or the raw material is charged. It can also be calculated from the ratio.

In a preferred embodiment of the present invention, preferably 30 mol% or more, more preferably 40 mol% or more, still more preferably 45 mol% or more, still more preferably 50 mol% of Z in the polyamide-imide resin or the polyamide-based resin. % Or more is a structural unit represented by the formula (3) or the formula (3') in which s is 0 to 4. When the above lower limit of Z or more is a structural unit represented by the formula (3) or the formula (3') in which s is 0 to 4, various physical properties of the transparent resin film can be easily enhanced. Further, 100 mol% or less of Z in the polyamide-imide resin or the polyamide-based resin may be a structural unit represented by the formula (3) or the formula (3') in which s is 0 to 4. The ratio of the structural units represented by the formula (3) or the formula (3') in which s is 0 to 4 in the resin ^{can be measured by using, for example, 1 1} H-NMR, or the raw material. It can also be calculated from the charge ratio.

In a preferred embodiment of the present invention, preferably 5 mol% or more, more preferably 8 mol% or more, still more preferably 10 mol% or more, still more preferably 12 mol% of Z in the polyamide-imide resin or the polyamide-based resin. % Or more is represented by the formula (3) or the formula (3') in which s is 1 to 4. When the above lower limit or more of Z of the polyamide-imide resin or the polyamide-based resin is represented by the formula (3) or the formula (3') in which s is 1 to 4, various physical properties of the transparent resin film are enhanced. Cheap. Further, the formula (3) or the formula (3) in which s is 1 to 4 in Z, preferably 90 mol% or less, more preferably 70 mol% or less, still more preferably 50 mol% or less, still more preferably 30 mol% or less. It is represented by the formula (3'). When the above upper limit or less of Z is represented by the formula (3) in which s is 1 to 4, it is derived from the structural unit represented by the formula (3) or the formula (3') in which s is 1 to 4. It is easy to improve the processability of the film by suppressing the increase in viscosity of the resin-containing varnish due to the hydrogen bond between the amide bonds. The ratio of the structural units represented by the formula (3) or the formula (3') in which s is 1 to 4 in the resin ^{can be measured by using, for example, 1 1} H-NMR, or the raw material charging ratio. It can also be calculated from.

In formulas (1) and (2), X is a divalent organic group, preferably a divalent organic group having 4 to 40 carbon atoms, more preferably a cyclic structure having 4 to 40 carbon atoms, independently of each other. Represents a divalent organic group of. Examples of the cyclic structure include an alicyclic ring, an aromatic ring, and a heterocyclic structure. In the organic group, the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a hydrocarbon group substituted with fluorine, in which case the number of carbon atoms of the hydrocarbon group and the hydrocarbon group substituted with fluorine is preferable. Is 1 to 8. In one embodiment of the present invention, the polyamide-imide resin of the present invention may contain a plurality of types of X, and the plurality of types of X may be the same as or different from each other. X is represented by the formula (10), the formula (11), the formula (12), the formula (13), the formula (14), the formula (15), the formula (16), the formula (17) and the formula (18). Groups; Groups in which the hydrogen atom in the groups represented by the formulas (10) to (18) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and a chain having 6 or less carbon atoms. The formula hydrocarbon group is exemplified.

In equations (10) to (18), * represents a bond,
V ^{1, V 2} and ^{V 3} independently of one another, 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 include the groups mentioned above for R ^9.
In one example, V ¹ and V ³ are single bonds, -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 with respect to each ring and the bonding positions of V ² and V ³ with respect to each ring are independent of each other, preferably in the meta position or para position with respect to each ring, and more preferably in the para position. It is a place.

Among the groups represented by the formulas (10) to (18), the formulas (13), the formula (14), the formula (15), and the formula (16) are used from the viewpoint of easily enhancing various physical properties of the transparent resin film. ) And the group represented by the formula (17) are preferable, and the group represented by the formula (14), the formula (15) and the formula (16) is more preferable. Further, V ¹ , V ² and V ³ are independent of each other, preferably single-bonded, -O- or -S-, more preferably single-bonded or, from the viewpoint of easily enhancing various physical properties of the transparent resin film. -O-.

［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、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高めやすい。 In a preferred embodiment of the present invention, the polyamide-based resin and the polyimide-based resin are represented by X in the formula (1) or X in the formula (2), and the formula (4):

[In formula (4), R ^{10 to} R ¹⁷ 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 substituted with halogen atoms independently of each other, and * represents a bond.]
Includes the structure represented by. When at least a part of X in the plurality of structural units represented by the formulas (1) and (2) has a structure represented by the formula (4), various chemical properties and physical properties of the transparent resin film are obtained. It is easy to improve the characteristics.

In formula (4), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are independent of each other, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and 1 carbon atom. Represents an alkoxy group of ~ 6 or an aryl group of 6-12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms include the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms in the formula (3). Examples thereof include groups exemplified as groups or aryl groups having 6 to 12 carbon atoms. R ^{10 to} R ¹⁷ represent independently of each other, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably an hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and here, R ^{10 to} R ¹⁷ The hydrogen atoms contained in the above may be substituted with halogen atoms independently of each other. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R ^{10 to} R ¹⁷ are more preferably hydrogen atoms, methyl groups, fluoro groups, chloro groups or trifluoromethyl groups, and even more preferably trifluoromethyl groups, independently of each other, from the viewpoint of various physical properties of the transparent resin film. R ¹⁰ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are hydrogen atoms, and R ¹¹ and R ¹⁷ are hydrogen atoms, methyl groups, fluoro groups, chloro groups or trifluoromethyl groups, particularly preferably R. ¹¹ and R ¹⁷ are methyl groups or trifluoromethyl groups.

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

That is, at least a part of X in the plurality of structural units represented by the equations (1) and (2) is the structural unit represented by the equation (4'). .. In this case, the skeleton containing a fluorine element enhances the solubility of the polyimide resin or the polyamide resin in the solvent, and it is easy to improve the storage stability of the varnish containing the resin, and it is easy to reduce the viscosity of the varnish. , It is easy to improve the workability of the transparent resin film. Further, the skeleton containing a fluorine element makes it easy to improve the optical characteristics of the transparent resin film.

In a preferred embodiment of the present invention, the formula (4), preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70 mol% or more, of X in the polyimide resin or the polyamide resin. In particular, it is represented by the equation (4'). When X in the above range in the polyimide resin or the polyamide resin is represented by the formula (4), particularly the formula (4'), the obtained transparent resin film has a skeleton containing a fluorine element to be used as a resin solvent. It is easy to increase the solubility and improve the storage stability of the varnish containing the resin, and it is easy to reduce the viscosity of the varnish and improve the processability of the transparent resin film. Further, the skeleton containing a fluorine element makes it easy to improve the optical characteristics of the transparent resin film. It should be noted that preferably, 100 mol% or less of X in the polyimide resin or the polyamide resin is represented by the formula (4), particularly the formula (4'). X in the resin may be of formula (4), especially of formula (4'). The ratio of the structural unit represented by the formula (4) of X in the resin ^{can be measured by using, for example, 1 1} H-NMR, or can be calculated from the charging ratio of the raw materials.

In the formula (1), Y represents a tetravalent organic group, preferably a tetravalent organic group having 4 to 40 carbon atoms, and more preferably a tetravalent organic group having a cyclic structure and having 4 to 40 carbon atoms. Represent. Examples of the cyclic structure include an alicyclic ring, an aromatic ring, and a heterocyclic structure, and an aromatic ring is preferably used from the viewpoint of easily increasing impact resistance and elastic modulus. The organic group is an organic group in which the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group, in which case the hydrocarbon group and the 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 a plurality of types of Y, and the plurality of types of Y may be the same as or different from each other. As Y, the following formulas (20), formulas (21), formulas (22), formulas (23), formulas (24), formulas (25), formulas (26), formulas (27), formulas (28) And a group represented by the formula (29); a group in which the hydrogen atom in the groups represented by the formulas (20) to (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; In addition, a chain hydrocarbon group having 4 or less valences of 6 carbon atoms is exemplified.

In the formula (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- _{CH 2 -Ar -, - Ar-} C (CH 3) represents a 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 the formulas (20) to (29), the formula (26), the formula (28) or the formula (29) from the viewpoint of easily enhancing various chemical properties and physical properties of the transparent resin film. The group represented by the formula (26) is preferable, and the group represented by the formula (26) is more preferable. Further, W ¹ is independent of each other, preferably single bond, −O−, from the viewpoint of easily enhancing various chemical properties and physical properties of the transparent resin film and easily reducing the YI value of the transparent resin film. _{-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 single bond, -C (CH ₃ ) _2- or -C (CF ₃₎ ) _2- , most preferably single bond or -C (CF ₃ ) _2- .

In a preferred embodiment of the present invention, Y in the polyimide resin is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol% or more, represented by the formula (26). Y is the formula in the range of polyimide resin (26) is preferably ^{W 1} is a single bond, -C _{(CH 3) 2} - or -C _{(CF 3) 2} - a is the formula (26), more preferably When W ¹ is represented by the formula (26), which is a single bond or −C (CF ₃ ) _2−, it is easy to enhance various chemical and physical properties of the transparent resin film, and the YI value of the transparent resin film is high. Is easy to reduce. The ratio of the structural unit in which Y in the polyimide resin is represented by the formula (26) ^{can be measured using, for example, 1 1} H-NMR, or can be calculated from the charging ratio of the raw materials.

［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）

［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 a preferred embodiment of the present invention, at least a part of Y in the plurality of formulas (1) is the formula (5) :.

[In formula (5), R ^{18 to} R ²⁵ 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 18 to} R ²⁵ may be substituted with halogen atoms independently of each other, and * represents a bond.]
And / or formula (9)

[In the formula (9), R ^{35 to} R ⁴⁰ represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and hydrogen contained in ^{R 35 to} R ^40. Atoms may be substituted with halogen atoms independently of each other, with * representing a bond]
It is represented by. When at least a part of Y in the plurality of formulas (1) is represented by the formula (5) and / or represented by the 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 independent of each other, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and 1 carbon atom. Represents an alkoxy group of ~ 6 or an aryl group of 6-12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, or the aryl group having 6 to 12 carbon atoms include the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms in the formula (3). Examples of groups or aryl groups having 6 to 12 carbon atoms can be mentioned above. R ^{18 to} R ²⁵ represent independently of each other, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably an hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and here, R ^{18 to} R ^25. The hydrogen atoms contained in the above may be substituted with halogen atoms independently of each other. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R ^{18 to} R ²⁵ are more preferably hydrogen atoms from the viewpoint of easily enhancing various physical properties of the transparent resin film and easily enhancing the transparency and maintaining the transparency independently of each other. Methyl, fluoro, chloro or trifluoromethyl groups, 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, It is 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 enhancing various chemical properties and physical properties of the transparent resin film, and easily increasing the transparency and maintaining the transparency, R ^{35 to} R ⁴⁰ are It is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and further preferably a hydrogen atom. Here, the ^{hydrogen atoms contained in R 35 to} R ⁴⁰ may be substituted with halogen atoms independently of each other, and examples of the halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, 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 are exemplified above.}

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

It is represented by. That is, at least a part of the plurality of Y is represented by the formula (5') and / or the formula (9'). In this case, it is easy to improve the physical properties of the transparent resin film. Further, when the formula (5) is represented by the formula (5'), the skeleton containing the fluorine element enhances the solubility of the polyimide resin in the solvent and improves the storage stability of the varnish containing the resin. In addition to being easy, it is easy to reduce the viscosity of the varnish and improve the processability of the transparent resin film. Further, the skeleton containing a fluorine element makes it easy to improve the optical characteristics of the transparent resin film.

In a preferred embodiment of the present invention, Y in the polyimide resin is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol% or more, according to the formula (5), particularly the formula (5). It is represented by'). When Y in the above range in the polyimide resin is represented by the formula (5), particularly the formula (5'), the skeleton containing a fluorine element enhances the solubility of the polyimide resin in the solvent and contains the resin. It is easy to reduce the viscosity of the varnish and improve the processability of the transparent resin film. Further, the skeleton containing a fluorine element makes it easy to improve the optical characteristics of the transparent resin film. It should be noted that preferably, 100 mol% or less of Y in the polyimide resin is represented by the formula (5), particularly the formula (5'). Y in the polyimide resin may be of the formula (5), particularly the formula (5'). The ratio of the structural units represented by the formula (5) of Y in the polyimide resin ^{can be measured using, for example, 1 1} H-NMR, or can be calculated from the charging ratio of the raw materials.

In a preferred embodiment of the present invention, the plurality of structural units represented by the formula (1) have a configuration in which Y is represented by the formula (9) in addition to the structural unit in which Y is represented by the formula (5). It is preferable to include more units. When Y further contains the structural unit represented by the formula (9), it is easy to further improve various physical properties of the transparent resin film.

The polyimide-based 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, in some cases, the formula (2). In addition to the structural unit represented by the formula (30), the structural unit represented by the formula (30) and / or the structural unit represented by the formula (31) may be included.

In the formula (30), Y ¹ is a tetravalent organic group, preferably an organic group in which the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a hydrocarbon group substituted with fluorine. Examples of Y ¹ include 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 the hydrogen atom in the groups represented by the formulas (20) to (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, and a group. A chain hydrocarbon group having a tetravalent carbon number of 6 or less is exemplified. In one embodiment of the present invention, a polyimide resin may include a plurality of kinds of Y ^1, Y ¹ of the plural kinds may being the same or different.

In the formula (31), Y ² is a trivalent organic group, preferably an organic group in which the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a hydrocarbon group substituted with fluorine. Examples of Y ² include the above equations (20), (21), (22), (23), (24), (25), (26), (27), and (28). ) And a group in which any one of the bonds of the group represented by the formula (29) is replaced with a hydrogen atom, and a chain hydrocarbon group having a trivalent carbon number of 6 or less are exemplified. In one embodiment of the present invention, a polyimide resin may include a plurality of kinds of Y ^2, Y ² a plurality of species may be be the same or different from each other.

In formulas (30) and (31), X ¹ and X ² are divalent organic groups independently of each other, and preferably a hydrocarbon group in which a hydrogen atom in the organic group is substituted with a hydrocarbon group or fluorine. It is an organic group that may be substituted with. Examples of X ¹ and X ² include the above equations (10), (11), (12), (13), (14), (15), (16), (17) and A group represented by the formula (18); a group in which a hydrogen atom in the groups represented by the formulas (10) to (18) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; 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 the formulas (1) and / or the formula (2), and optionally a configuration represented by the formulas (30) and / or the formula (31). It consists of units. Further, from the viewpoint of easily enhancing the optical properties and various physical properties of the transparent resin film, the proportions of the structural units represented by the formulas (1) and (2) in the polyimide resin are the formulas (1) and. Based on the formula (2), and optionally all the structural units represented by the formulas (30) and (31), preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more. Is. In the polyimide resin, the proportions of the structural units represented by the formulas (1) and (2) are the formulas (1) and (2), and in some cases, the formulas (30) and / or the formula (31). It is usually 100% or less based on all the structural units represented by. The above ratio can be measured using, for example, ^{1 1} H-NMR, or can be calculated from the raw material charging ratio.

In one embodiment of the present invention, the content of the polyimide resin and / or the polyamide resin in the transparent resin film is preferably 10 parts by mass or more, more preferably 30 parts by mass with respect to 100 parts by mass of the transparent resin film. As mentioned above, it is more preferably 50 parts by mass or more, preferably 99.5 parts by mass or less, and more preferably 95 parts by mass or less. When the content of the polyimide resin and / or the polyamide resin is within the above range, various chemical properties and physical properties of the transparent resin film can be easily improved.

The weight average molecular weight (Mw) of the polyimide resin and the polyamide resin is preferably 200,000 or more, more preferably 200,000 or more in terms of standard polystyrene from the viewpoint of easily enhancing various chemical properties and physical properties of the transparent resin film. It is 230,000 or more, more preferably 250,000 or more, even more preferably 270,000 or more, and particularly preferably 280,000 or more. The weight average molecular weight of the polyimide resin and the polyamide resin is preferably 1,000, from the viewpoints that the solubility of the resin in a solvent is easily improved and the stretchability and processability of the transparent resin film are easily improved. It is 000 or less, more preferably 800,000 or less, still more preferably 700,000 or less, and even more preferably 500,000 or less. The weight average molecular weight can be determined by, for example, GPC measurement and standard polystyrene conversion, and may be calculated by, for example, the method described in Examples.

In the polyamide imide resin, the content of the structural unit represented by the formula (2) is preferably 0.1 mol or more, more preferably 0.5 mol or more, with respect to 1 mol of the structural unit represented by the formula (1). More than mol, more preferably 1.0 mol or more, even 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. is there. When the content of the structural unit represented by the formula (2) is at least the above lower limit, various physical properties of the transparent resin film can be easily enhanced. Further, when the content of the structural unit represented by the formula (2) is not more than the above upper limit, the thickening due to the hydrogen bond between the amide bonds in the formula (2) is suppressed, and the processability of the transparent resin film is improved. Easy to improve.

In a preferred embodiment of the present invention, the polyimide resin and / or the polyamide resin contained in the transparent resin film contains a halogen atom such as a fluorine atom which can be introduced by, for example, the above-mentioned fluorine-containing substituent or the like. Good. When the polyimide resin and / or the polyamide resin contains a halogen atom, the YI value of the transparent resin film can be easily reduced. When the YI value of the transparent resin film is low, it becomes easy to improve the transparency and visibility of the film. The halogen atom is preferably a fluorine atom. Preferred fluorine-containing substituents for containing a fluorine atom in the polyimide resin include, for example, a fluoro group and a trifluoromethyl group.

The content of halogen atoms in the polyimide resin and the polyamide resin is preferably 1 to 40% by mass, more preferably 5 to 40% by mass, still more preferably 5 to 40% by mass, based on the mass of the polyimide resin and the polyamide resin, respectively. It is 5 to 30% by mass. When the content of the halogen atom is at least the above lower limit, the YI value of the transparent resin film is further reduced, and the transparency and visibility are more likely to be improved. When the content of halogen atoms is not more than the above upper limit, synthesis becomes easy.

The imidization ratio of the polyimide resin and the polyamide-imide resin is preferably 90% or more, more preferably 93% or more, still more preferably 96% or more. From the viewpoint of easily improving the optical characteristics of the transparent resin film, the imidization ratio is preferably at least the above lower limit. The upper limit of the imidization rate is 100% or less. The imidization ratio indicates the ratio of the molar amount of the imide bond in the polyimide resin to twice the molar amount of the structural unit derived from the tetracarboxylic acid compound in the polyimide resin. When the polyimide resin contains a tricarboxylic acid compound, the value is twice the molar amount of the structural unit derived from the tetracarboxylic acid compound in the polyimide resin, and the molar amount of the structural unit derived from the tricarboxylic acid compound. The ratio of the molar amount of the imide bond in the polyimide resin to the total of the above is shown. The imidization rate can be determined by an IR method, an NMR method, or the like.

Commercially available products may be used as the polyimide resin and the polyamide resin. Examples of commercially available polyimide resins include Neoprim (registered trademark) manufactured by Mitsubishi Gas Chemical Company, Ltd., KPI-MX300F manufactured by Kawamura Sangyo Co., Ltd., and the like.

In the present invention, the transparent resin film may contain a polyamide resin. The polyamide-based resin according to this embodiment is a polymer mainly composed of a repeating structural unit represented by the formula (2). Preferred examples and specific examples of Z in the formula (2) in the polyamide-based resin are the same as preferable examples and specific examples 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) having different Z's.

［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、ｓｅｃ−ブトキシ基、ｔｅｒｔ−ブトキシ基又は塩素原子を表す。］ (Resin manufacturing method)
The polyimide resin and the polyimide precursor resin can be produced, for example, using a tetracarboxylic acid compound and a diamine compound as main raw materials, and the polyamide-imide resin and the polyamide-imide precursor resin can be produced, for example, by a tetracarboxylic acid compound, a dicarboxylic acid compound and a diamine compound. Can be produced as a main raw material, and the polyamide resin can be produced, for example, using a diamine compound and a dicarboxylic acid compound as main raw materials. Here, the dicarboxylic acid compound preferably contains at least a compound represented by the formula (3 ").

[In the formula (3 ″), R ^{1 to} R ⁸ independently contain 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. Represented, the ^{hydrogen atoms contained in R 1 to} R ⁸ may be substituted with halogen atoms independently of each other.
A represents a single _{bond, -O -, - CH 2 -} , - CH 2 -CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - C (CF 3) 2 -, - Represents SO _2- , -S-, -CO- or -N (R ⁹ )-
R ⁹ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydrogen atom or a halogen atom.
m is an integer from 0 to 4
R ³¹ and R ³² independently represent a hydroxyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group or a chlorine atom. ]

In a preferred embodiment of the present invention, the dicarboxylic acid compound is a compound represented by the formula (3 ") in which m is 0. The dicarboxylic acid compound is represented by the formula (3") in which m is 0. It is more preferable to use a compound represented by the formula (3 ″) in which A is an oxygen atom in addition to the compound to be used. In another preferred embodiment, the dicarboxylic acid compound is R ³¹ and It is a compound represented by the formula (3 ″) in which R ^{32 is a chlorine atom.} Further, a diisocyanate compound may be used instead of the diamine compound.

Examples of the diamine compound used in the production of the resin include aliphatic diamines, aromatic diamines and mixtures thereof. In addition, in this embodiment, "aromatic diamine" represents a diamine in which an amino group is directly bonded to an aromatic ring, and an aliphatic group or other substituent may be contained in a part of the structure. The aromatic ring may be a monocyclic ring or a condensed ring, and examples thereof include, but are not limited to, a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring. Among these, a benzene ring is preferably exemplified. Further, the "aliphatic diamine" represents a diamine in which an amino group is directly bonded to an aliphatic group, and an aromatic ring or other substituent may be contained as a part of the structure thereof.

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

Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylene diamine, p-xylylene diamine, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene and the like. , 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'- Diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 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 (with TFMB) (May be described), 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 alone or in combination of two or more.

The aromatic diamines are preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 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, 2,2'-bis ( Trifluoromethyl) -4,4'-diaminodiphenyl (TFMB), 4,4'-bis (4-aminophenoxy) biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl. Propane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 1,4-bis (4-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2- Bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB), 4,4'- Biphenyl (4-aminophenoxy) biphenyl. These can be used alone or in combination of two or more.

Among the above diamine compounds, from the viewpoint of various high physical properties of the transparent resin film, it is preferable to use one or more selected from the group consisting of aromatic diamines having a biphenyl structure. One selected from the group consisting of 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine, 4,4'-bis (4-aminophenoxy) biphenyl and 4,4'-diaminodiphenyl ether. It is more preferable to use the above, and it is even more preferable to use 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB).

Examples of the tetracarboxylic acid compound used in the production of the resin include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic dianhydride; and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydride. Be done. The tetracarboxylic acid compound may be used alone or in combination of two or more. The tetracarboxylic dian compound may be a tetracarboxylic dian compound analog such as an acid chloride compound in addition to the dianhydride.

Specific examples of aromatic tetracarboxylic dianhydrides include non-condensed polycyclic aromatic tetracarboxylic dianhydrides, monocyclic aromatic tetracarboxylic dianhydrides, and condensed polycyclic aromatic tetraides. Examples include carboxylic dianhydride. Examples of the non-condensed polycyclic aromatic tetracarboxylic dianhydride include 4,4'-oxydiphthalic acid dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride and 2,2. ', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride , 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-di) Describe as carboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA). There are), 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) Examples thereof include −dicarboxyphenyl) methane dianhydride, 4,4'-(p-phenylenedioxy) diphthalic acid dianhydride, and 4,4'-(m-phenylenedioxy) diphthalic acid dianhydride. Examples of the monocyclic aromatic tetracarboxylic dianhydride include 1,2,4,5-benzenetetracarboxylic dianhydride, and the condensed polycyclic aromatic dianhydride dianhydride. Examples thereof include 2,3,6,7-naphthalenetetracarboxylic dianhydride.

Among these, preferably 4,4'-oxydiphthalic acid dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2', 3,3'-benzophenonetetracarboxylic dianhydride. Anhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-diphenyl Sulfontetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2- Bis (3,4-dicarboxyphenoxyphenyl) propanedianhydride, 4,4'-(hexafluoroisopropyridene) diphthalic acid dianhydride (6FDA), 1,2-bis (2,3-dicarboxyphenyl) Etan 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-) Examples thereof include phenylenedioxy) diphthalic dianhydride and 4,4'-(m-phenylenedioxy) diphthalic dianhydride, more preferably 4,4'-oxydiphthalic dianhydride, 3,3',. 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropyridene) diphthalic acid dianhydride (6FDA) , Bis (3,4-dicarboxyphenyl) methane dianhydride and 4,4'-(p-phenylenedioxy) diphthalic dianhydride. These can be used alone or in combination of two or more.

Examples of the aliphatic tetracarboxylic dianhydride include cyclic or acyclic aliphatic tetracarboxylic dianhydride. 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. Cycloalkanetetracarboxylic dianhydride such as 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2.2] .2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl-3,3', 4,4'-tetracarboxylic dianhydride and their positional isomers are listed. 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, 1,2,3,4-pentanetetracarboxylic dianhydride and the like. These can be used alone or in combination of two or more. Further, a cyclic aliphatic tetracarboxylic dianhydride and an acyclic aliphatic tetracarboxylic dianhydride may be used in combination.

Among the above tetracarboxylic dianhydrides, 4,4'-oxydiphthalic dianhydride, 3,3', 4,4'-benzophenonetetra from the viewpoint of various physical properties and high transparency of the transparent resin film. Carcarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4 '-Diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propanedianhydride, 4,4'-(hexafluoroisopropyridene) diphthalic acid dianhydride, and these A mixture is preferable, 3,3', 4,4'-biphenyltetracarboxylic dianhydride and 4,4'-(hexafluoroisopropyridene) diphthalic acid dianhydride, and a mixture thereof are more preferable, 4,4. More preferred are'-(hexafluoroisopropyridene) diphthalic acid dianhydride (6FDA) and 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA).

As the dicarboxylic acid compound used in the production of the resin, terephthalic acid, isophthalic acid, 4,4'-oxybis benzoic acid or an acid chloride compound thereof is preferably used. In addition to terephthalic acid, isophthalic acid, 4,4'-oxybis benzoic acid or their acid chloride compounds, other dicarboxylic acid compounds may be used. Examples of other dicarboxylic acid compounds include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, acid chloride compounds related thereto, acid anhydrides, and the like, and two or more of them may be used in combination. Specific examples include a dicarboxylic acid compound of isophthalic acid; naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; a chain hydrocarbon having 8 or less carbon atoms, and two benzoic acids. Examples thereof include compounds in which is single-bonded, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO _2- or phenylene groups, and their acid chloride compounds. As a specific example, 4,4'-oxybis (benzoyl chloride), terephthaloyl chloride or isophthaloyl chloride are preferable, and 4,4'-oxybis (benzoyl chloride) and terephthaloyl chloride can be used in combination. More preferred.

The polyimide resin is obtained by further reacting tetracarboxylic acid and tricarboxylic acid and their anhydrides and derivatives in addition to the tetracarboxylic acid compound as long as the various physical properties of the transparent resin film are not impaired. You may.

Examples of the tetracarboxylic acid include a water adduct of the anhydride of the tetracarboxylic acid compound.

Examples of the tricarboxylic acid compound include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, acid chloride compounds related thereto, acid anhydrides, and the like, and two or more of them may be used in combination. Specific examples include an anhydride of 1,2,4-benzenetricarboxylic acid; an anhydride of 1,3,5-benzenetricarboxylic acid; 2,3,6-naphthalenetricarboxylic acid-2,3-anhydride; phthalic acid. A compound in which an anhydride and benzoic acid are single-bonded, -O-, -CH _2- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO _2- or a phenylene group is linked. Can be mentioned.

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

In the production of the resin, the reaction temperature of the diamine compound, the tetracarboxylic acid compound and the dicarboxylic acid compound is not particularly limited, but is, for example, 5 to 350 ° C., preferably 20 to 200 ° C., and 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 necessary, the reaction may be carried out under conditions of an inert atmosphere or reduced pressure. In a preferred embodiment, the reaction is carried out under normal pressure and / or an atmosphere of an inert gas with stirring. 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, and for example, water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, etc. Alcohol-based solvents such as 2-butoxyethanol and propylene glycol monomethyl ether; ester-based solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, γ-valerolactone, propylene glycol methyl ether acetate and ethyl lactate; Ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; alicyclic hydrocarbon solvents such as ethyl cyclohexane; toluene and xylene Aromatic hydrocarbon solvents such as; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; amides such as N, N-dimethylacetamide and N, N-dimethylformamide. System solvents; sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane; carbonate solvents such as ethylene carbonate and propylene carbonate; and combinations thereof. Among these, an amide-based solvent can be preferably used from the viewpoint of solubility.

In the imidization step in the production of the polyimide resin, imidization can be performed in the presence of an imidization catalyst. Examples of imidization catalysts include aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; N-ethylpiperidin, N-propylpiperidin, N-butylpyrrolidin, N-butylpiperidin, and N-propylhexahydro. Alicyclic amines such as azepine (monocyclic); azabicyclo [2.2.1] heptane, azabicyclo [3.2.1] octane, azabicyclo [2.2.2] octane, and azabicyclo [3.2. 2] Alicyclic amines such as nonane (polycyclic); and pyridine, 2-methylpyridine (2-picolin), 3-methylpyridine (3-picolin), 4-methylpyridine (4-picolin), 2- Ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2,4-dimethylpyridine, 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and Examples include aromatic amines such as isoquinolin. Further, from the viewpoint of easily promoting the imidization reaction, it is preferable to use an acid anhydride together with the imidization catalyst. Examples of the acid anhydride include conventional acid anhydrides used in the imidization reaction, and specific examples thereof include acetic anhydride, propionic anhydride, butyric anhydride and other aliphatic acid anhydrides, and phthalic acid and other aromatics. Acid anhydride and the like can be mentioned.

Polyimide-based resins and polyamide-based resins are isolated (separated and purified) by conventional methods, for example, separation means such as filtration, concentration, extraction, crystallization, recrystallization, and column chromatography, or separation means combining these. In a preferred embodiment, a reaction solution containing a transparent polyamideimide resin can be isolated by adding a large amount of alcohol such as methanol to precipitate the resin, and performing concentration, filtration, drying and the like.

(Transparent resin film)
In the present invention, the content of the polyimide resin and / or the polyamide resin in the resin composition constituting the transparent resin film is preferably 40% by mass or more, more preferably 50% by mass, based on the solid content of the resin composition. % Or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and may be 100% by mass. When the content of the polyimide resin and / or the polyamide resin is at least the above lower limit value, the flexibility of the transparent resin film is good. The solid content refers to the total amount of the components excluding the solvent from the resin composition.

In the present invention, the resin composition for forming the transparent resin film may further contain an inorganic material such as inorganic particles in addition to the above-mentioned polyimide-based resin and / or polyamide-based resin. Examples of the inorganic material include inorganic particles such as silica particles, titanium particles, aluminum hydroxide, zirconia particles, and barium titanate particles, and silicon compounds such as quaternary alkoxysilane such as tetraethyl orthosilicate. From the viewpoint of the stability of the varnish and the dispersibility of the inorganic material, silica particles, aluminum hydroxide, and zirconia particles are preferable, and silica particles are more preferable.

The average primary particle size of the inorganic material particles is preferably 10 to 100 nm, more preferably 10 to 70 nm, still more preferably 10 to 50 nm, and even more preferably 10 to 30 nm. When the average primary particle size of the silica particles is in the above range, the transparency tends to be improved, and the cohesive force of the silica particles is weakened, so that the silica particles tend to be easy to handle.

In the present invention, the silica particles may be a silica sol in which silica particles are dispersed in an organic solvent or the like, or silica fine particle powder produced by a vapor phase method, but are preferably liquids because they are easy to handle. It is a silica sol produced by the phase method.

The average primary particle size of the silica particles in the transparent resin film can be determined by observation with a transmission electron microscope. The particle size distribution of the silica particles before forming the transparent resin film can be obtained by a commercially available laser diffraction type particle size distribution meter.

In the present invention, when the resin composition contains an inorganic material, the content thereof is preferably 0.001% by mass or more and 90% by mass or less, more preferably 10% by mass or more and 60, based on the solid content of the resin composition. It is mass% or less, more preferably 20 mass% or more and 50 mass% or less. When the content of the inorganic material in the resin composition is within the above range, the transparency and mechanical strength of the transparent resin film tend to be compatible with each other. The solid content refers to the total amount of the components excluding the solvent from the resin composition.

The resin composition constituting the transparent resin film may further contain other components in addition to the components described above. Other components include, for example, antioxidants, mold release agents, light stabilizers, bluing agents, flame retardants, lubricants and leveling agents.

In the present invention, when the resin composition contains a resin component such as a polyimide resin and other components other than the inorganic material, the content of the other components is preferably 0.001 mass with respect to the total mass of the transparent resin film. % Or more and 20% by mass or less, more preferably 0.001% by mass or more and 10% by mass or less.

In the present invention, the transparent resin film is, for example, a reaction solution of a polyimide resin and / or a polyamide resin obtained by selecting and reacting with the tetracarboxylic acid compound, the diamine and the other raw materials, if necessary. It can be produced from a resin varnish prepared by adding a solvent to a resin composition containing an inorganic material and other components, mixing and stirring. In the resin composition, a solution of the purchased polyimide resin or the like or a solution of the purchased solid polyimide resin or the like may be used instead of the reaction solution of the polyimide resin or the like.

As the solvent used for preparing the resin varnish, a solvent capable of dissolving or dispersing a resin component such as a polyimide resin can be appropriately selected. From the viewpoint of solubility, coatability, drying property and the like of the resin component, 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, and particularly preferably 120. ~ 230 ° C. Specific examples of such an organic solvent include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone; and lactone solvents such as γ-butyrolactone and γ-valerolactone. Ketone solvents such as cyclohexanone, cyclopentanone, and methyl ethyl ketone; acetate solvents such as butyl acetate and amyl acetate; sulfur-containing solvents such as dimethyl sulfoxide, dimethyl sulfoxide, and sulfolane, and carbonate solvents such as ethylene carbonate and propylene carbonate. And so on. Among them, N, N-dimethylacetamide (boiling point: 165 ° C.), γ-butyrolactone (boiling point: 204 ° C.), N-methylpyrrolidone (boiling point: 202 ° C.) because of its excellent solubility in polyimide-based resin and polyamide-based resin. , Butyl acetate (boiling point: 126 ° C.), cyclopentanone (boiling point: 131 ° C.) and amyl acetate (boiling point: 149 ° C.). 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 type of solvent so that the boiling point of the solvent having the highest boiling point among the solvents used falls within the above range.

The amount of the solvent may be selected so as to have a viscosity that allows the resin varnish to be handled, and is not particularly limited. For example, the amount of the solvent is preferably 50 to 95 parts by mass with respect to 100 parts by mass of the solid content of the resin composition. It is more preferably 70 to 95 parts by mass, and further preferably 80 to 95 parts by mass.

The thickness of the transparent resin film after drying may be appropriately determined according to the intended use of the transparent resin film, but is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, still more preferably 25 μm or more, still more. It is preferably 30 μm or more, usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, still more preferably 80 μm or less, still more preferably 60 μm or less, and may be a combination of the upper limit and the lower limit thereof. .. When the thickness of the transparent resin film is within the above range, the impact resistance of the transparent resin film can be more easily improved. The thickness of the transparent resin film can be measured using a micrometer, for example, by the method described in Examples. When the thickness of the transparent resin film is within the above range, the flexibility of the transparent resin film tends to be good.

The total light transmittance of the transparent resin film after drying is preferably 80% or more, more preferably 85% or more, still more preferably 88% or more, even more preferably 89% or more, particularly preferably 90% or more, especially more. It is preferably 91% or more, and usually 100% or less. When the total light transmittance is equal to or higher than the above lower limit, it is easy to improve visibility when the transparent resin film is incorporated into an image display device, particularly as a front plate. Since the transparent resin film of the present invention usually exhibits a high total light transmittance, for example, the emission intensity of a display element or the like required to obtain a constant brightness can be determined as compared with the case where a film having a low transmittance is used. It becomes possible to suppress it. Therefore, power consumption can be reduced. For example, when the transparent resin film of the present invention is incorporated into an image display device, a bright display tends to be obtained even if the amount of light from the backlight is reduced, which can contribute to energy saving. The total light transmittance can be measured using a haze computer in accordance with, for example, JIS K 7105: 1981 or JIS K 7361-1: 1997. Further, the total light transmittance may be the total light transmittance in the range of the thickness of the transparent resin film described later.

The haze of the transparent resin film after drying is preferably 3% or less, more preferably 2.5% or less, still more preferably 1.5% or less, still more preferably 1.0% or less, and particularly preferably 0.5. % Or less, more preferably 0.3% or less, usually 0.01% or more. When the haze of the transparent resin film is not more than the above upper limit, it is easy to improve the visibility when the optical film is incorporated into an image display device, particularly as a front plate. The haze can be measured using a haze computer in accordance with JIS K 7105: 1981 or JIS K 7136: 2000.

The YI value of the transparent resin film after drying is usually 0.1 or more, preferably 3.0 or less, more preferably 2.5 or less, still more preferably 2.2 or less. When the YI value of the transparent resin film is not more than the above upper limit, the transparency becomes good, and it can contribute to high visibility when used for the front plate of the image display device. The YI value was measured by measuring the transmittance of light at 300 to 800 nm using an ultraviolet-visible near-infrared spectrophotometer, and the tristimulus values (X, Y, Z) were obtained, and YI = 100 × (1.2769X−). It can be calculated based on the formula of 1.0592Z) / Y.

The tensile elastic modulus of the transparent resin film after drying is preferably 4.5 GPa or more, more preferably 5.0 GPa or more, still more preferably 5.5 GPa or more, still more preferably 6 from the viewpoint of easily preventing scratches and the like. It is 0.0 GPa or more, particularly preferably 6.2 GPa or more, particularly more preferably 6.4 GPa or more, and usually 100 GPa or less. The tensile elastic modulus can be measured using a tensile tester (distance between chucks 50 mm, tensile speed 10 mm / min), for example, by the method described in Examples.

The solvent content of the transparent resin film after drying is determined by the weight loss rate M from 120 ° C. to 250 ° C. determined by thermogravimetric-differential thermal measurement (hereinafter sometimes referred to as "TG-DTA measurement"). It is preferably 0.0001% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.3% by mass or more, preferably 2% by mass or less, more preferably 1.8% by mass or less, still more preferably. Is 1.7% by mass or less, particularly preferably 1.2% by mass or less.

<Manufacturing method of film roll before drying>
The production method of the pre-drying (after pre-drying) film roll used in the present invention is not particularly limited, but for example, the following steps:
(A) A step of applying a polyimide resin and / or a polyamide resin and a resin varnish containing at least a solvent onto a support, drying the resin, and forming a coating film.
(B) Step of peeling the coating film from the support,
(C) It can be produced by a production method including at least a step of forming a film roll by winding the peeled coating film around a roll core.

The resin varnish used in the above step (a) contains at least a polyimide resin and / or a polyamide resin and a solvent. Examples of the resin and solvent contained in the resin varnish include the resins described above as the resin contained in the transparent resin film. Further, the resin varnish may contain additives such as the above-mentioned inorganic materials.

The resin varnish can be prepared by mixing the above-mentioned polyimide-based resin and / or polyamide-based resin, solvent, and additives used as necessary, and stirring the mixture.

The viscosity of the resin varnish is preferably 5,000 to 60,000 cps, more preferably 10,000 to 50,000 cps, and even more preferably 15,000 to 45,000 cps. When the viscosity of the resin varnish is at least the above lower limit, the effect of the present invention can be easily obtained, and when it is at least the above upper limit, the handling of the resin varnish can be easily improved.

The solid content concentration of the resin varnish is preferably 5 to 25% by mass, more preferably 6 to 23% by mass, and further preferably 7 to 20% by mass. It is preferable that the solid content concentration of the resin varnish is at least the above lower limit from the viewpoint of obtaining a thick film, and it is preferable that the solid content concentration is at least the above upper limit from the viewpoint of ease of handling of the resin varnish.

Examples of the support include a resin base material, a stainless steel belt, a glass base material, and the like. It is preferable to use a resin film base material as the support. Examples of the resin film base material include polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, cycloolefin-based (COP) film, acrylic film, polyimide film, polyamideimide film, and the like. Among them, smoothness. From the viewpoint of excellent heat resistance, a PET film, a COP film and the like are preferable, and from the viewpoint of adhesion to a transparent resin film and cost, a PET film is more preferable.

The thickness of the support is not particularly limited, but is preferably 50 to 250 μm, more preferably 100 to 200 μm, and even more preferably 125 to 200 μm. When the thickness of the support is not more than the above upper limit, it is preferable because the manufacturing cost of the transparent resin film can be easily suppressed. Further, it is preferable that the thickness of the support is at least the above lower limit because it is easy to suppress the curl of the film that may occur in the step of removing at least a part of the solvent. Here, the thickness of the support is measured by a contact-type film thickness meter or the like.

When the resin varnish is applied onto the support, it may be applied to the support by a known application method. Known coating methods include, for example, wire bar coating method, reverse coating, roll coating method such as gravure coating, die coating method, comma coating method, lip coating method, spin coating method, screen coating method, fountain coating method, dipping method, and the like. Examples include a spray method and a salivation molding method.

Next, the coating film can be formed by drying the coating film of the resin varnish applied on the support. The drying is performed by removing at least a part of the solvent from the coating film of the resin varnish, and the drying method is not particularly limited. For example, the coating film of the resin varnish applied on the support may be heated for drying. The drying performed here is pre-drying, which is different from the drying performed by the method for producing a dried film roll of the present invention.

Next, in the step (b), the dried coating film is peeled off from the support. The peeling method is not particularly limited, and the coating film may be moved and peeled while the support is fixed, or the support may be moved and peeled while the coating film is fixed. Then, the peeling may be performed by moving both the coating film and the support.

The thickness of the transparent resin film before drying is usually 11 μm or more, preferably 16 μm or more, more preferably 21 μm or more, still more preferably 26 μm or more, still more preferably 31 μm or more, and usually 301 μm or less, preferably 201 μm or less. It is more preferably 101 μm or less, further preferably 90 μm or less, and even more preferably 61 μm or less. When the thickness of the transparent resin film is within the above range, the impact resistance of the transparent resin film can be more easily improved. The thickness of the transparent resin film can be measured using a micrometer, for example, by the method described in Examples.

The solvent content of the transparent resin film before drying is determined by thermogravimetric-differential thermal measurement (hereinafter sometimes referred to as "TG-DTA measurement") in the same manner as the solvent content of the transparent resin film after drying 120. It is determined by the weight loss rate M from ° C. to 250 ° C., and is preferably 5% by mass or more, more preferably 6% by mass or more, further preferably 7% by mass or more, preferably 20% by mass or less, and more preferably 15% by weight. It is less than mass%.

Next, in the step (c), the film is wound around the core and takes the form of a film roll. In the process of manufacturing the film roll, a protective film may be formed on one side of the transparent resin film, if necessary.

In the present invention, the method for producing a dried film of the present invention is used when the film roll obtained in the above step (c), that is, the pre-dried film roll is main-dried. The method for producing a dried film roll of the present invention, again described, comprises the following steps:
The process of unwinding the film from the raw material film roll,
The process of transporting the unwound film,
The process of grasping and drying the edges of the film,
After drying, it has a step of releasing the grip and a step of winding the film to obtain a dried film roll. In the above step, the step of gripping the end of the film, drying it, and then releasing the grip is performed by the tenter stretching device 41 and the drying furnace 54 of FIG. 9, so that the transparent resin film, particularly a polymer such as polyimide or polyamide, is used. The transparent resin film based on the above is effectively prevented from cracking during drying. When the method for producing a dried film roll of the present invention is used, the production yield is increased and it is effective for producing a transparent resin film.

In the production method of the present invention, cracking of the film during the drying process in the tenter stretching apparatus can be reduced, so that the drying step is stably carried out for a long period of time, and there are few measures such as stopping the apparatus during film production, so that the production efficiency is improved. An increase is desired. In addition, since the number of films that cannot be shipped due to cracking or breaking is reduced, the amount of film discarded is reduced, which can contribute to resource saving and energy saving.

Hereinafter, the present invention will be described in more detail with reference to Examples. Unless otherwise specified, "%" and "part" in the example mean mass% and parts by mass. First, a method for measuring physical property values will be described.

<Weight average molecular weight>
Gel Permeation Chromatography (GPC) Measurement (1) Pretreatment Method After dissolving the sample in γ-butyrolactone (GBL) to make a 20% by mass solution, dilute it 100 times with a DMF eluent and use a 0.45 μm membrane filter. The filtered solution was used as the measurement solution.
(2) Measurement condition column: TSKgel SuperAWM-H × 2 + SuperAW2500 × 1 (inner diameter 6.0 mm, length 150 mm, 3 connected)
Eluent: DMF (10 mmol / L lithium bromide added)
Flow rate: 0.6 mL / min Detector: RI detector Column temperature: 40 ° C
Injection volume: 20 μL
Molecular weight standard: Standard polystyrene

上記式において、αはポリアミド酸（イミド化率０％）の場合におけるアミドプロトン１個に対するベンゼンプロトンＡの個数割合である。 <Imidization rate>
The imidization ratio was ^{determined by 1} H-NMR measurement as follows.
(1) Pretreatment method A sample _{was dissolved in deuterated dimethyl sulfoxide (DMSO-d 6} ) to prepare a 2% by mass solution, which was used as a measurement solution.
(2) Measurement conditions Measuring device: JEOL 400MHz NMR device JNM-ECZ400S / L1
Standard substance: DMSO-d ₆ (2.5 ppm)
Sample temperature: Room temperature Integral number: 256 times Relaxation time: 5 seconds (3) ^{Imidization rate analysis method In the obtained 1} H-NMR spectrum, benzene protons were observed at 7.0 to 9.0 ppm, of which imidization was performed. The integral ratio of benzene proton A derived from the structure that does not change before and after was defined as Int _A. Further, amide protons having an amic acid structure remaining in the polyimide were observed at 10.5 to 11.5 ppm, and this integration ratio was defined as Int _B. From these integration ratios, the imidization ratio was calculated by the following formula.

In the above formula, α is the number ratio of benzene protons A to one amide proton in the case of polyamic acid (imidization ratio 0%).

<Average primary particle size>
The specific surface area of the powder obtained by drying the silica sol at 300 ° C. was measured using a specific surface area measuring device Monosorb MS-16 manufactured by Yuasa Aiokunis Co., Ltd., and the measured specific surface area S (m ² / g) was used. The average primary particle size was calculated by the formula of D (nm) = 2720 / S.

<Varnish viscosity>
The measurement was performed using an E-type viscometer DV-II + Pro manufactured by Brookfield Co., Ltd. in accordance with JIS K 8803: 2011. The measurement temperature was 25 ° C.

<Thickness and thickness distribution of support>
Using ID-C112XBS manufactured by Mitutoyo Co., Ltd., the thickness of 20 points or more was measured in the width direction of the support, and the difference between the average value and each data was calculated to obtain a thickness distribution.

<Film thickness>
Using ID-C112XBS manufactured by Mitutoyo Co., Ltd., the film thickness at 10 points or more was measured, and the average value was calculated.

<Total light transmittance of film, haze, light transmittance of 380 nm and light transmittance of 420 nm>
The above optical characteristic values were measured using a spectrocolorimeter CM-3700A manufactured by Konica Minolta Co., Ltd.

<Amount of residual solvent>
Using TG-DTA (EXSTAR6000 TG / DTA6300 manufactured by SII Co., Ltd.), the transparent resin films obtained in Examples 1 and 2 and Comparative Examples and 2 were heated from 30 ° C. to 120 ° C. and 5 at 120 ° C. It was held for 1 minute, and then the temperature was raised to 400 ° C. at a heating rate of 5 ° C./min. The ratio of the mass loss of the film from 120 ° C. to 250 ° C. to the mass of the film at 120 ° C. was calculated as the solvent content (referred to as the residual solvent amount).

The abbreviations used in the following production examples and examples are as follows.
TFMB: 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl 6FDA: 4,4'-(hexafluoroisopropyridene) diphthalic acid dianhydride TPC: terephthaloyl chloride OBBC: 4,4 '-Oxybis (benzoyl chloride)
DMAc: N, N-dimethylacetamide GBL: γ-butyrolactone PET: polyethylene terephthalate

<Manufacturing example>
Production Example 1: Production of Polyamide-imide Resin 1 Under a nitrogen gas atmosphere, a reaction vessel equipped with a stirring blade in a separable flask and an oil bath were prepared. 45 parts of TFMB and 768.55 parts of DMAc were put into a reaction vessel installed in an oil bath. TFMB was dissolved in DMAc while stirring the contents in the reaction vessel at room temperature. Next, 19.01 parts of 6FDA was further charged into the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 3 hours. Then, 4.21 parts of OBBC and then 17.30 parts of TPC were put into the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 1 hour. Next, 4.63 parts of 4-methylpyridine and 13.04 parts of acetic anhydride were further added to the reaction vessel, and the contents in the reaction vessel were stirred at room temperature for 30 minutes. After stirring, the temperature inside the container was raised to 70 ° C. using an oil bath, maintained at 70 ° C., and stirred for another 3 hours to obtain a reaction solution.
The obtained reaction solution was cooled to room temperature and poured into a large amount of methanol in the form of filaments to precipitate a precipitate. The precipitated precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C. to obtain a polyamide-imide resin 1. The weight average molecular weight of the obtained polyamide-imide resin 1 was 380,000, and the imidization ratio was 99.0%.

Production Example 2: Production of Polyimide Resin 1 A reactor equipped with a silica gel tube, a stirrer and a thermometer in a separable flask, and an oil bath were prepared. 75.52 parts of 6FDA and 54.44 parts of TFMB were put into this flask. While stirring this at 400 rpm, 519.84 parts of DMAc was added, and stirring was continued until the contents of the flask became a uniform solution. Subsequently, stirring was continued for another 20 hours while adjusting the temperature inside the container to be in the range of 20 to 30 ° C. using an oil bath, and the reaction was carried out to generate a polyamic acid. After 30 minutes, the stirring speed was changed to 100 rpm. After stirring for 20 hours, the reaction system temperature was returned to room temperature, and 649.8 parts of DMAc was added to adjust the polymer concentration to 10% by mass. Further, 32.27 parts of pyridine and 41.65 parts of acetic anhydride were added, and the mixture was stirred at room temperature for 10 hours for imidization. The polyimide varnish was taken out from the reaction vessel. The obtained polyimide varnish was dropped into methanol for reprecipitation, and the obtained powder was dried by heating to remove the solvent to obtain a polyimide resin 1 as a solid content. The weight average molecular weight of the obtained polyimide resin 1 was 325,000, and the imidization ratio was 98.8%.

Production Example 3: Preparation of Silica Sol 1 An amorphous silica sol produced by a sol-gel method and having an average primary particle size of 27 nm measured by the BET method was used as a raw material, and a GBL-substituted silica sol was prepared by solvent substitution. The obtained sol was filtered through a membrane filter having an opening of 10 μm to obtain GBL-substituted silica sol 1. The content of silica particles in the obtained GBL-substituted silica sol 1 was 30% by mass.

Production Example 4: Preparation of Varnish (1) The composition ratio of the polyamide-imide resin 1 obtained in Production Example 1 and the silica sol obtained in Production Example 3 to the polyamide-imide resin: silica particles in the GBL solvent is 60. It was mixed so as to be: 40. In the obtained mixed solution, an ultraviolet absorber "Sumisorb (registered trademark) 340" (manufactured by Sumika Chemtex Co., Ltd.) of 5.7 phr with respect to the total mass of the polyamide-imide resin and the silica particles and the polyamide-imide resin and the silica particles were added. 35 ppm of brewing agent "Sumiblast (registered trademark) Violet B" (manufactured by Sumika Chemtex Co., Ltd.) was added to the total mass of the particles, and the mixture was stirred until uniform to obtain a varnish (1). The solid content of the varnish (1) was 10.8% by mass, and the viscosity at 25 ° C. was 38,300 cps.

Production Example 5: Preparation of varnish (2) Polyimide resin 1 obtained in Production Example 2 and 5.0 phr UV absorber "Sumisolv 340" (manufactured by Sumika Chemtex Co., Ltd.) are applied to the polyimide resin. , GBL: DMAc = 1: 9 was dissolved in a mixed solvent at a concentration of 16.5% by mass to obtain a varnish (2). The solid content of the varnish (2) was 16.6% by mass, and the viscosity at 25 ° C. was 37,000 cps.

Production example 6
The varnish (1) was applied onto a PET film (Toyobo Co., Ltd. "Cosmo Shine (registered trademark) A4100", thickness 188 μm, thickness distribution ± 2 μm) and salivated to form a varnish coating film. At this time, the line speed was 0.5 m / min. The coating film is dried under the drying conditions of heating at 80 ° C. for 10 minutes, then at 100 ° C. for 10 minutes, then at 90 ° C. for 10 minutes, and finally at 80 ° C. for 10 minutes. Was formed. Then, the dry coating film was peeled off from the PET film to obtain a raw material film 1 having a thickness of 48 μm, a width of 700 mm, and a length of 1,000 m. The amount of residual solvent in the raw material film 1 was 9.7% by mass.

Production example 7
The varnish (2) was applied onto a PET film (Toyobo Co., Ltd. "Cosmo Shine (registered trademark) A4100", thickness 188 μm, thickness distribution ± 2 μm) and salivated to form a varnish coating film. At this time, the line speed was 0.4 m / min. The varnish coating is heated at 70 ° C. for 7.5 minutes, then at 120 ° C. for 7.5 minutes, then at 70 ° C. for 7.5 minutes, and finally at 75 ° C. for 7.5 minutes. It was dried under dry conditions to form a dry coating film. Then, the coating film was peeled off from the PET film to obtain a raw material film 2 having a thickness of 89 μm, a width of 700 mm, and a length of 1,000 m. The amount of residual solvent in the raw material film 2 was 9.6% by mass.

Example 1
The rolled raw material film 1 obtained in Production Example 6 is fed out, and immediately before the tenter drying furnace having the six drying chambers shown in FIG. 9, the curved shape of the grip portion (position 1, position 2, position 3 and position 4). The film is gripped using a clip as a gripping tool as shown in Table 1 for the radius of curvature R), the distance between the gripping portion and the pedestal, and the positional relationship between the gripping portion end and the pedestal end, and is conveyed as it is into the dryer. did. The temperature inside the dryer is set to 200 ° C, the clip gripping width is 25 mm, the line speed of the film is 1.3 m / min, and the ratio of the film width at the dryer outlet to the film width at the dryer inlet (distance between clips) is 1.0. The air velocity in each room of the tenter type dryer was adjusted to 13.5 m / sec in one room, 13 m / sec in two rooms, and 11 m / sec in three to six rooms. The solvent of the raw material film 1 was removed using a dryer (1 to 6 drying chamber configuration) to obtain a polyamide imide film 1 having a thickness of 49 μm. After the film is separated from the clip, the film in the gripped part is slit, a polyethylene terephthalate (PET) protective film is further attached, and the film is wound around an ABS resin 6-inch core without breaking the film. A film roll having a length of 900 m was obtained. The first 100 m of the film was discarded because the stability of the film performance could not be obtained, and the subsequent 900 m was wound on a film roll. In the obtained film, the residual solvent amount was 0.5% by mass, the tensile elastic modulus was 7.0 GPa, the total light transmittance was 89.8%, the haze was 0.2%, and YI. The value was 1.6. For the film, the clip cracking frequency was evaluated according to the following criteria.

<Clip crack frequency>
While processing the film roll, the portion gripped by the clip was visually observed, the frequency of cracking was observed, and the evaluation was made according to the following criteria. If the frequency of cracking is low, the risk of film breakage is low.
⊚: Very good (frequency less than 10%; when the raw material film of 1,000 m is provided, the ratio of the number of clip grips in which the film is cracked to the total number of clip grips is less than 10%. , Similar criteria.)
〇: Good (frequency less than 20%)
Δ: Slightly good (frequency less than 30%)
×: Defective (frequency 30% or more)

Comparative Example 1
A film roll was obtained in the same manner as in Example 1 except that the end portion of the film contact surface of the gripper parallel to the film transport direction was changed to one having no curved surface shape. In the obtained film, the residual solvent amount was 0.5% by mass, the tensile elastic modulus was 7.0 GPa, the total light transmittance was 89.8%, and the haze was 0.2%. The YI value was 1.6.

Comparative Example 2
A film roll was obtained in the same manner as in Example 1 except that the distance between the grip portion and the pedestal was changed to 150 μm as shown in Table 1. In the obtained film, the residual solvent amount was 0.5% by mass, the tensile elastic modulus was 7.0 GPa, the total light transmittance was 89.8%, the haze was 0.2%, and YI. The value was 1.6. In Comparative Example 2, the distance between the grip portion and the pedestal is 150 μm, which is considerably larger than the thickness of the raw material film of 49 μm, but the closest distance between the grip portion and the pedestal is slightly smaller than the thickness of the raw material film, and the film is loosely gripped. Is possible.

Example 2
A film roll was obtained in the same manner as in Example 1 except that the distance between the grip portion and the pedestal was changed as shown in Table 1. In the obtained film, the residual solvent amount was 0.5% by mass, the tensile elastic modulus was 7.0 GPa, the total light transmittance was 89.8%, the haze was 0.2%, and YI. The value was 1.6.

Example 3
A film roll was obtained in the same manner as in Example 1 except that the curved surface shape of the grip and the positional relationship between the grip end and the pedestal end were changed as shown in Table 1. In the obtained film, the residual solvent amount was 0.5% by mass, the tensile elastic modulus was 7.0 GPa, the total light transmittance was 89.8%, the haze was 0.2%, and YI. The value was 1.6.

Example 4
A film roll was obtained in the same manner as in Example 1 except that the curved surface shape of the grip and the positional relationship between the grip end and the pedestal end were changed as shown in Table 1. In the obtained film, the residual solvent amount was 0.5% by mass, the tensile elastic modulus was 7.0 GPa, the total light transmittance was 89.8%, the haze was 0.2%, and YI. The value was 1.6.

Example 5
The distance between the grip and the pedestal is set to 24 μm, and in the curved shape of the end parallel to the transport direction on the film contact surface of the grip, the radius of curvature R ₁ = 10 mm to the vicinity of the center of the curved shape, and the radius of curvature thereafter. A film roll was obtained in the same manner as in Example 1 except that _{R 2 = 5 mm.} In the obtained film, the residual solvent amount was 0.5% by mass, the tensile elastic modulus was 7.0 GPa, the total light transmittance was 89.8%, the haze was 0.2%, and YI. The value was 1.6.

Example 6
Using the raw material film 2, a film roll having a thickness of 79 μm was obtained in the same manner as in Example 1 except that the film transport speed was 0.9 m / min. In the obtained film, the residual solvent amount was 1.0% by mass, the tensile elastic modulus was 4.1 GPa, the total light transmittance was 91.3%, the haze was 0.2%, and YI. The value was 1.3.

表１中、「Ｒ１／Ｒ２」は中間点で曲率半径がＲ１からＲ２に変化することを意味し、「Ｒ無」は曲率半径が無いこと、即ち角が直角であることを意味する。

In Table 1, "R1 / R2" means that the radius of curvature changes from R1 to R2 at the midpoint, and "without R" means that there is no radius of curvature, that is, the angles are right angles.

In Table 1, the curved surface shape of the grip portion is represented by the “curvature radius R (mm) of the grip portion”, and the “position 1” and “position 2” are the end portions of the film contact surface perpendicular to the film transport direction (in FIG. 2). 9) is the radius of curvature, and "position 3" and "position 4" are the radius of curvature of the end of the film contact surface (10 in FIG. 2) parallel to the film transport direction. The “distance (μm) between the grip portion and the pedestal” is represented by the interval 12 in FIG. The "positional relationship between the grip portion end portion and the pedestal end portion (mm)" is the distance (mm) between the end face parallel to the film transport direction of the grip portion and the end face parallel to the pedestal film transport direction, and is shown in FIG. Some are represented by 22. The film thickness (μm) in Table 1 represents the thickness of the raw material film and the thickness of the film after processing (after tenter drying) in μm.

As is clear from Table 1 above, all the clips having a curved surface shape at the end of the film contact surface of the grip portion have a clip cracking frequency of Δ (slightly good) or more. When there is a portion of the grip portion on the film contact surface that does not have a curved surface shape (Comparative Example 1), the clip cracks increase due to the contact with the end portion. Further, in Comparative Example 2, the distance between the grip portion and the pedestal is 150 μm, and the film is not sufficiently gripped and the film moves. Therefore, the clip cracks increase due to the sliding between the film and the pedestal or the grip portion.

1 ... Gripping tool 2 ... Pedestal 3 ... Gripping part 4 ... Film 5 ... fulcrum 6 ... fulcrum support part 7 ... Connecting part 8 ... Film contact surface 9 ... Film contact surface end portion perpendicular to film transfer direction 31 10 ... Film transfer direction The end of the film contact surface parallel to 31 11 ... the intersection 12 ... the distance between the grip and the pedestal 15 ... the end of the film-receiving surface of the pedestal 16 ... the corner of the film-receiving part of the pedestal 20 ... grip End face parallel to the transport direction of the film of the part 21 ... End face parallel to the transport direction of the film on the pedestal 22 ... Distance between the end face 20 and the end face 21 31 ... Film transport direction 41 ... Tenter stretching device 42 ... Introduction part 43 ... Delivery Part 51 ... Film roll 52 ... Roll 53 ... Protective film 54 ... Drying furnace 55 ... Dried film roll

Claims (12)

The process of unwinding the film from the raw material film roll,
The process of transporting the unwound film,
The process of grasping and drying both ends of the film parallel to the film transport direction,
A method for producing a dried film roll using a tenter stretching apparatus, which comprises a step of releasing the grip after drying and a step of winding the film to obtain a dried film roll.
The gripping portion comprises a pedestal and a gripping portion, and the film is gripped between the pedestal and the gripping portion.
The distance between the pedestal and the grip portion is thinner than the thickness of the film.
All the ends of the film contact surface of the grip portion that comes into contact with the film have a curved surface shape.
How to make a film roll. The manufacturing method according to claim 1, wherein the curved surface shape of the film contact surface end portion of the grip portion has a radius of curvature R of 3 mm ≤ radius of curvature R ≤ 15 mm. The manufacturing method according to claim 1 or 2, wherein the curved surface shape of the end portion parallel to the transport direction on the surface of the grip portion in contact with the film is asymmetrical with respect to the vicinity of the center of the curved surface shape. The manufacturing method according to any one of claims 1 to 3, wherein the intersections at the ends perpendicular to and parallel to the transport direction of the film on the surface of the grip portion in contact with the film have a curved surface shape. The manufacturing method according to any one of claims 1 to 4, wherein the distance between the pedestal and the grip portion is 1/2 or less of the thickness of the film. The grip portion is movable around a fulcrum and can be fixed at the lowest point, the fulcrum exists in the direction opposite to the pedestal with respect to the film, and the end portion of the film is the lowermost portion of the grip portion. The manufacturing method according to any one of claims 1 to 5, which is gripped at a point. The manufacturing method according to any one of claims 1 to 6, wherein the fulcrum is fixed to the pedestal. When the grip portion grips the film at the lowest point at a distance from the pedestal, the position of the end face parallel to the film transport direction of the grip portion is ± 1 mm at the position of the end face parallel to the pedestal film transport direction. The production method according to any one of claims 1 to 7. The production method according to any one of claims 1 to 8, wherein the solvent content in the film before drying is 5% by mass or more. The production method according to any one of claims 1 to 9, wherein the solvent content in the film after drying is 2% by mass or less. The production method according to any one of claims 1 to 10, wherein the film has a tensile elastic modulus of 4 GPa or more after drying. The production method according to any one of claims 1 to 11, wherein the film is a film containing at least one resin selected from the group consisting of a polyimide resin and a polyamide resin.

Images