JP2023014999A - Resin film, method for producing the same, resin composition, and method for producing display - Google Patents

Abstract

To provide a resin film that has high transparency and high heat resistance, and has a large elongation.SOLUTION: Provided is a resin film that contains a resin having a repeating unit represented by a predetermined chemical structure, and in which the ratio (H1/H2) of the peak height (H1) including wavenumber 1850 cm-1 and the peak height (H2) including wavenumber 1775 cm-1 in IR measurement is 0.14 or less.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a resin film, a method for producing the same, a resin composition, and a method for producing a display.

Polyimide is used as a material for various electronic devices such as semiconductors and displays due to its excellent electrical insulation, heat resistance and mechanical properties. Recently, by using a polyimide film for substrates of displays such as organic EL displays, electronic papers, and color filters, impact-resistant and flexible displays can be manufactured.

Materials used in electronic devices are required to have high heat resistance to withstand high-temperature processes in device manufacturing. Particularly in applications requiring transparency, a material capable of achieving both heat resistance and transparency is required.

For example, Patent Document 1 discloses an example of manufacturing an organic EL display using polyimide, which has high heat resistance and excellent mechanical properties, as a substrate. Further, Patent Document 2 discloses an example of manufacturing an organic EL display using polyimide having excellent transparency as a substrate. In addition, Patent Document 3 discloses an example of using a photosensitive polyimide having excellent low thermal expansion properties for electronic device applications by using an acid dianhydride with a specific structure.

WO2017/099183 WO2015/046019 JP-A-2003-255525

The polyimide resin film described in Patent Document 1 has a problem that it cannot be applied to applications that require transparency because the light transmittance of the resin film is insufficient. The polyimide resin film described in Patent Literature 2 has insufficient heat resistance, and has the problem of being difficult to apply to electronic devices that require high-temperature processes during manufacturing. The polyimide resin film described in Patent Document 3 has insufficient elongation, and has a problem that it cannot be applied particularly to flexible electronic devices.

The present invention has the following configurations.
[1] A peak height (H1) containing a wave number of 1850 cm ^-1 and a peak height (H2) containing a wave number of 1775 cm ^-1 in IR measurement, including a resin having a repeating unit represented by the chemical formula (1). A resin film having a ratio (H1/H2) of 0.14 or less.

In chemical formula (1), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms. B represents a diamine residue having 2 or more carbon atoms. However, 30 mol % or more of A is the tetracarboxylic acid residue having the structure represented by the chemical formula (3).

In chemical formula (3), X ¹ and X ² are each independently a direct bond, an oxygen atom, a sulfur atom, a carbonyl group, a thiocarbonyl group, a sulfonyl group, a structure represented by chemical formula (4), or chemical formula (5) It is a structure represented by

In chemical formulas (4) and (5), Y is a carbon atom, a silicon atom, a boron atom, a nitrogen atom, or a phosphorus atom. n is 1 or 2 and m is an integer of 2-8. Each R ³ is independently a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group. Each Z is independently a structure represented by the chemical formula (6) or a structure represented by the chemical formula (7).

In chemical formulas (6) and (7), R ⁴ to R ⁹ each independently represent a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group.
[2] The resin film according to [1], wherein the 0.1% weight loss temperature of the resin film is 460° C. or higher.
[3] In the chemical formula (3), X ¹ and X ² are each independently an oxygen atom, a sulfur atom, a structure represented by the chemical formula (4) or a structure represented by the chemical formula (5), and the chemical formula ( 4) and chemical formula (5), each R ³ is independently an aromatic hydrocarbon group having 1 to 10 carbon atoms or an aromatic heterocyclic group, and Z is a structure represented by chemical formula (6) The resin film according to [1] or [2].
[4] The resin film according to any one of [1] to [3], wherein in chemical formula (3), X ¹ is an oxygen atom and X ² is a structure represented by chemical formula (9) below.
[5] The resin film according to any one of [1] to [4], which is used as a display substrate.
[6] For a resin film containing a resin having a repeating unit represented by the chemical formula (2) and a solvent, the resin composition is applied and baked at 430 ° C. for 30 minutes, the wavenumber in IR measurement is 1850 cm ⁻ A resin composition, wherein the ratio (H1/H2) of the height of the peak including ¹ (H1) and the height of the peak including the wave number of 1775 cm ⁻¹ (H2) is 0.14 or less.

In chemical formula (2), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms. B represents a diamine residue having 2 or more carbon atoms. However, 30 mol % or more of A is the tetracarboxylic acid residue having the structure represented by the chemical formula (3). R ¹ and R ² each independently represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an alkylsilyl group having 1 to 10 carbon atoms, an alkali metal ion, an ammonium ion, an imidazolium ion or a pyridinium ion .

In chemical formula (3), X ¹ and X ² are each independently a direct bond, an oxygen atom, a sulfur atom, a carbonyl group, a thiocarbonyl group, a sulfonyl group, a structure represented by chemical formula (4), or chemical formula (5) It is a structure represented by

In chemical formulas (4) and (5), Y is a carbon atom, a silicon atom, a boron atom, a nitrogen atom, or a phosphorus atom. n is 1 or 2 and m is an integer of 2-8. Each R ³ is independently a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group. Each Z is independently a structure represented by the chemical formula (6) or a structure represented by the chemical formula (7).

In chemical formulas (6) and (7), R ⁴ to R ⁹ each independently represent a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group.
[7] The resin composition according to [6], which contains 0.1 parts by mass or more and less than 100 parts by mass of the imidization accelerator with respect to 100 parts by mass of the resin.
[8] The resin composition according to [7], wherein the imidization accelerator is a nitrogen atom-containing heterocyclic compound.
[9] The resin composition according to [8], wherein the imidization accelerator is a heterocyclic compound further containing a hydroxyl group.
[10] A method for producing a resin film, comprising the step of applying the resin composition according to any one of [6] to [9] to a support and baking the composition at 400°C or higher and 500°C or lower.
[11] forming a resin film on a support by the method for producing a resin film according to [10]; forming a display element on the resin film; and separating the resin film from the support. A method of manufacturing a display, comprising:

The resin film according to the present invention has a high light transmittance at a wavelength of 400 nm, a low yellowness index (hereinafter referred to as YI), and excellent transparency. In addition, the resin film has a high glass transition temperature (hereinafter referred to as Tg), is excellent in heat resistance, has a large elongation, and is excellent in mechanical properties. Therefore, it can be suitably used for flexible electronic devices that require heat resistance and transparency.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be carried out with various modifications according to purposes and applications.

<Resin film>
A resin film according to an embodiment of the present invention contains a resin having a repeating unit represented by chemical formula (1).

In chemical formula (1), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms. B represents a diamine residue having 2 or more carbon atoms. However, 30 mol % or more of A is the tetracarboxylic acid residue having the structure represented by the chemical formula (3).

In chemical formula (3), X ¹ and X ² are each independently a direct bond, an oxygen atom, a sulfur atom, a carbonyl group, a thiocarbonyl group, a sulfonyl group, a structure represented by chemical formula (4), or chemical formula (5) It is a structure represented by

In chemical formulas (4) and (5), Y is a carbon atom, a silicon atom, a boron atom, a nitrogen atom, or a phosphorus atom. n is 1 or 2 and m is an integer of 2-8. Each R ³ is independently a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group. Each Z is independently a structure represented by the chemical formula (6) or a structure represented by the chemical formula (7).

In chemical formulas (6) and (7), R ⁴ to R ⁹ each independently represent a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group.

Examples of resins having repeating units represented by chemical formula (1) include polyimide resins, polyetherimide resins, and polyamideimide resins.

The resin film according to the embodiment of the present invention has a ratio (H1/H2) of a peak height (H1) including a wavenumber of 1850 cm ⁻¹ and a peak height (H2) including a wavenumber of 1775 cm ⁻¹ in IR measurement. 0.14 or less.

A wavenumber of 1775 cm ⁻¹ in IR measurement corresponds to an imide group, and a wavenumber of 1850 cm ⁻¹ corresponds to an acid anhydride. H1/H2 can be said to be an index indicating the amount of acid anhydride relative to the imide groups in the resin film. If the value of H1/H2 is 0.14 or less, the number of terminal structures that tend to cause coloration of the resin film is reduced, and the transparency of the resin film is enhanced. Also, the smaller the molecular weight of the resin, the larger the terminal structure and the larger the value of H1/H2. Therefore, when H1/H2 is 0.14 or less, the molecular weight of the resin film is sufficiently high, and the elongation of the resin film is large. A value of H1/H2 of 0.11 or less is preferable because the resin film has a higher elongation. The lower limit of H1/H2 is not particularly limited, but is preferably 0.01 or more.

IR measurement in the present invention is performed using a Fourier transform infrared spectrophotometer. A transmission method, an ATR method (total reflection method), or the like can be selected as the measurement mode depending on the form of the sample and the measurement location, but there is no particular limitation. Note that H1 and H2 are peak heights when a line connecting the skirts of each peak is used as a baseline.

(tetracarboxylic acid residue)
In the chemical formula (1), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms, and such a tetracarboxylic acid residue is a tetravalent hydrocarbon group having 2 to 80 carbon atoms. preferable. In addition, A is a tetravalent organic group having 2 to 80 carbon atoms containing hydrogen atoms and carbon atoms as essential components and containing one or more atoms selected from boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen. There may be. The number of boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen atoms contained in the organic group is each independently preferably in the range of 20 or less, more preferably in the range of 10 or less. .

In chemical formula (1), 30 mol % or more of A is a tetracarboxylic acid residue having a structure represented by chemical formula (3). As a result, the resin has a rigid structure, and the Tg of the resin film increases. In chemical formula (1), preferably 50 mol % or more of A, more preferably 70 mol % or more of A is a tetracarboxylic acid residue having a structure represented by chemical formula (3). If 50 mol% or more of A is a tetracarboxylic acid residue having a structure represented by the chemical formula (3), it has excellent transmittance at 400 nm, a low coefficient of linear thermal expansion (hereinafter referred to as CTE), and a Tg. It tends to be a higher resin film.

In chemical formula (3), X ¹ and X ² are each independently preferably an oxygen atom, a sulfur atom, a structure represented by chemical formula (4) or a structure represented by chemical formula (5). If X ¹ and X ² have these structures, the benzene rings in the chemical formula (3) are non-conjugated with each other, so that the transmittance of the resin film is higher. X ¹ and X ² are each independently preferably an oxygen atom or a structure represented by Chemical Formula (5).

In the chemical formula (4), R ³ is preferably an aromatic hydrocarbon group having 1 to 10 carbon atoms or an aromatic heterocyclic group because of excellent heat resistance. In the chemical formula (5), it is preferable for Z to have a structure represented by the chemical formula (6), because the heat resistance is excellent. In particular, from the viewpoint of compatibility between transparency and heat resistance, the structure represented by Chemical Formula (5) is particularly preferably the structure represented by Chemical Formula (9). The structure represented by the chemical formula (9) is a structure represented by the chemical formula (5) in which Y is a carbon atom, m is 2, and Z is represented by the chemical formula (6). , R ⁴ to R ⁷ are hydrogen atoms.

Most preferably, in chemical formula ( ³ ), X1 is ^an oxygen atom and X2 is a structure represented by chemical formula (9). That is, most preferably, chemical formula (3) is a tetracarboxylic acid residue having a structure represented by chemical formula (10). If the chemical formula (3) is the tetracarboxylic acid residue having the structure represented by the chemical formula (10), the resin film will be extremely excellent in heat resistance and transparency.

Other examples of the tetracarboxylic acid residue having the structure represented by the chemical formula (3) include the tetracarboxylic acid residues described below.

Other tetracarboxylic acids that give A are not particularly limited, and known ones can be used. For example, monocyclic aromatic tetracarboxylic acid compounds, various isomers of biphenyltetracarboxylic acid, bis(dicarboxyphenyl) compounds, bis(dicarboxyphenoxyphenyl) compounds, naphthalene or various isomers of condensed polycyclic aromatic tetracarboxylic acids aromatic tetracarboxylic acids such as bis(trimellitic acid monoester) compounds; and aliphatic tetracarboxylic acids such as alicyclic tetracarboxylic acids and chain aliphatic tetracarboxylic acids.

Examples of aromatic tetracarboxylic acids include pyromellitic acid, 3,3′,4,4′-biphenyltetracarboxylic acid, 2,3,3′,4′-biphenyltetracarboxylic acid, 2,2′, 3,3′-biphenyltetracarboxylic acid, 3,3′,4,4′-benzophenonetetracarboxylic acid, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane, bis(3,4-di carboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)ether, 9,9-bis(3,4-dicarboxyphenyl)fluorene and the like. In the present invention, a tetracarboxylic acid giving a tetracarboxylic acid residue having the structure represented by the chemical formula (3) is also regarded as an aromatic tetracarboxylic acid.

Examples of alicyclic tetracarboxylic acids include cyclobutanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, dicyclohexyl-3,3′,4,4′-tetracarboxylic acid, chemical formula (33) , (34) or (35) which gives a tetracarboxylic acid residue.

In chemical formula (33), p represents an integer of 0-3. In chemical formula (34), q represents an integer of 1-4. In chemical formula (35), r represents an integer of 0-2.

Examples of chain aliphatic tetracarboxylic acids include butanetetracarboxylic acid.

Examples of tetracarboxylic acids that give A include tetracarboxylic acids described in International Publication No. 2017/099183.

These tetracarboxylic acids can be used as they are or in the form of acid anhydrides, active esters or active amides as starting materials for giving A, and two or more of these can be used.

From the viewpoint of obtaining a resin film with higher heat resistance, A is aromatic in preferably 50 mol% or more, more preferably 80 mol% or more, of the repeating units represented by the chemical formula (1) contained in the resin. A tetracarboxylic acid residue is preferred.

In addition, as the tetracarboxylic acid that gives A, the coatability to the support when producing the resin film, and the resistance to oxygen plasma and UV ozone treatment used for cleaning when forming elements on the resin film are improved. Therefore, silicon-containing tetracarboxylic acids such as dimethylsilanediphthalic acid and 1,3-bis(phthalic acid)tetramethyldisiloxane may be used. When using these silicon-containing tetracarboxylic acids, it is preferable to use 1 to 30 mol % of the total tetracarboxylic acid.

In the tetracarboxylic acids exemplified above, part of the hydrogen contained in the residue of the tetracarboxylic acid is a hydrocarbon group having 1 to 10 carbon atoms such as a methyl group and an ethyl group, and a carbon group such as a trifluoromethyl group. It may be substituted with groups such as 1 to 10 fluoroalkyl groups, F, Cl, Br, I, OH, COOH, SO ₃ H, CONH ₂ and SO ₂ NH ₂ .

(diamine residue)
In chemical formula (1), B represents a divalent diamine residue having 2 or more carbon atoms, and such a diamine residue is preferably a divalent hydrocarbon group having 2 to 80 carbon atoms. In addition, B is a divalent organic group having 2 to 80 carbon atoms containing hydrogen atoms and carbon atoms as essential components and containing one or more atoms selected from boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen. There may be. The number of boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen atoms contained in the organic group is each independently preferably in the range of 20 or less, more preferably in the range of 10 or less. .

The diamine that gives B is not particularly limited, and known ones can be used. For example, monocyclic aromatic diamine compounds, naphthalene or condensed polycyclic aromatic diamine compounds, bis(diaminophenyl) compounds or various derivatives thereof, 4,4′-diaminobiphenyl or various derivatives thereof, bis(aminophenoxy) compounds, A bis(3-amino-4-hydroxyphenyl) compound, a bis(aminobenzoyl) compound, a heterocycle-containing diamine compound, or a portion of the hydrogens bonded to the aromatic rings contained in these diamine compounds are replaced with hydrocarbons or halogens. Aromatic diamines such as compounds such as , and aliphatic diamines such as chain aliphatic diamine compounds and alicyclic diamine compounds.

Examples of aromatic diamines include diamines that give diamine residues represented by chemical formula (8) or chemical formula (11).

In chemical formula (8), R ¹⁰ to R ¹⁵ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms or a halogenated hydrocarbon group having 1 to 10 carbon atoms. t is an integer of 1 to 3; u is 0 or 1; In chemical formula (11), R ¹⁶ to R ²¹ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms or a halogenated hydrocarbon group having 1 to 10 carbon atoms.

Examples of the diamine giving the diamine residue represented by the chemical formula (8) include p-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1 ,4-phenylenediamine, 2,2′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diamino-3,3′-dimethylbiphenyl, 4,4′-diamino-3,3′,5, 5'-tetramethylbiphenyl, 2,5-difluoro-1,4-phenylenediamine, 2,3,5,6-tetrafluoro-1,4-phenylenediamine, 4,4'-diamino-2,2'- bis(trifluoromethyl)biphenyl and the like.

Examples of diamines giving diamine residues represented by the chemical formula (11) include 1,5-naphthalene diamine, 2-methylnaphthalene-1,5-diamine, 4-methylnaphthalene-1,5-diamine, 2 ,6-dimethylnaphthalene-1,5-diamine, 2-trifluoromethylnaphthalene-1,5-diamine, 4-trifluoromethylnaphthalene-1,5-diamine, 2,6-bistrifluoromethylnaphthalene-1,5 - diamine, and the like.

Examples of other aromatic diamines include m-phenylenediamine, 3,5-diaminobenzoic acid, bis(4-aminophenoxyphenyl)sulfone, bis(3-aminophenoxyphenyl)sulfone, 1,4-bis( 4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 9, 9-bis(4-aminophenyl)fluorene, 4,4'-diaminobenzanilide, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 3,4'- diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 4-aminophenyl 4-aminobenzoate, 1,1'-binaphthalene-4,4'-diamine, and the like.

Examples of linear aliphatic diamines include ethylenediamine, propylenediamine, butanediamine, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,4-bis(aminomethyl)cyclohexane, and the like.

Examples of cycloaliphatic diamines include, for example, cyclohexanediamine, 4,4'-methylenebis(cyclohexylamine), and the like.

In addition, examples of diamines that give B include diamines described in International Publication No. 2017/099183.

These diamines can be used as they are or as the corresponding trimethylsilylated diamines to give B, or two or more of these can be used.

From the viewpoint of obtaining a resin film with higher heat resistance, preferably 50 mol% or more, more preferably 80 mol% or more of the repeating units represented by the chemical formula (1) contained in the resin, B is an aromatic A diamine residue is preferred.

In chemical formula (1), preferably 60 mol % or more of B, more preferably 80 mol % or more of B is a diamine residue having a structure represented by chemical formula (8) or chemical formula (11). If 60 mol % or more of B is a diamine residue having a structure represented by chemical formula (8) or chemical formula (11), the resin film tends to have a low CTE and a high Tg.

Particularly preferably, in chemical formula (1), 50 mol % or more of A is an aromatic tetracarboxylic acid residue, and 50 mol % or more of B is an aromatic diamine residue. More preferably, in chemical formula (1), 50 mol% or more of A is a tetracarboxylic acid residue having a structure represented by chemical formula (10), and 60 mol% or more of B is chemical formula (8) or chemical formula ( 11) is a diamine residue having a structure represented by 11). If A and B have these structures, it is easy to obtain a resin film that is superior in heat resistance and transparency and has a lower CTE.

In addition, the diamine that provides B is used to improve the coatability of the substrate when producing the resin film, and the resistance to oxygen plasma and UV ozone treatment used for cleaning when forming elements on the resin film. , 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,3-bis(4-anilino)tetramethyldisiloxane, and the like may also be used. When using these silicon-containing diamine compounds, it is preferable to use 1 to 30 mol % of the total diamine compounds.

In the diamine compounds exemplified above, part of the hydrogen contained in the diamine compound is a hydrocarbon group having 1 to 10 carbon atoms such as a methyl group and an ethyl group, and a hydrocarbon group having 1 to 10 carbon atoms such as a trifluoromethyl group. It may be substituted with groups such as fluoroalkyl groups, F, Cl, Br, I, OH, COOH, _{SO3H , CONH2} , _SO2NH2 .

The value obtained by dividing the number of moles of tetracarboxylic acid residues contained in the resin by the number of moles of diamine residues contained in the resin (hereinafter referred to as "divided value Ka") is not particularly limited. , 0.900 or more and 1.100 or less. When the division value Ka is within the above range, the polyimide has a high molecular weight, so that the film tends to have a large elongation. From the viewpoint of transparency, the division value Ka is more preferably 1.000 or more and 1.050 or less.

As the division value Ka approaches 1, the number of moles of the diamine residue and the tetracarboxylic acid residue approaches equimolar, so the number of repeating units represented by the chemical formula (1) tends to increase. When the division value Ka is less than 1, the terminal of the polymer structure having the repeating unit represented by the chemical formula (1) tends to become a diamine, and when it is greater than 1, the polymer structure having the repeating unit represented by the chemical formula (1) The terminal tends to be tetracarboxylic acid.

The resin film according to the embodiment of the present invention may be one in which the ends of the resin are blocked with a terminal blocker. A highly transparent resin film is likely to be obtained by sealing the ends of the resin with the terminal blocking agent.

When the terminal monomer of the resin is a diamine compound, a dicarboxylic acid anhydride, a monocarboxylic acid, a monocarboxylic acid chloride compound, a monocarboxylic acid active ester compound, a dicarbonic dialkyl ester, or the like is used to block the amino group. can be used as a terminal blocker.

When the terminal monomer of the resin is an acid dianhydride, a monoamine, monoalcohol, or the like can be used as a terminal blocking agent to block the acid anhydride group.

Although the resin film according to the embodiment of the present invention is not particularly limited, the light transmittance at a wavelength of 400 nm is preferably 10% or more, more preferably 30% or more, and 50% or more. is more preferable. The YI of the resin film is preferably 18 or less, more preferably 14 or less, and even more preferably 10 or less. When the light transmittance and/or YI satisfy these ranges, the resin film has excellent transparency and can be suitably used for applications requiring transparency. In the present invention, the yellowness of the resin film is determined according to JIS K 7373:2006.

The film thickness of the resin film according to the embodiment of the present invention is preferably 4 μm or more, more preferably 5 μm or more, and even more preferably 6 μm or more, from the viewpoint of elongation of the resin film. The film thickness of the resin film is preferably 40 μm or less, more preferably 30 μm or less, and even more preferably 25 μm or less. When the film thickness of the resin film is 4 μm or more and 40 μm or less, the elongation of the resin film becomes good. In applications where higher transparency is required, the film thickness is preferably 0.5 μm or more and 4 μm or less, more preferably 1 μm or more and 3 μm or less.

The resin film according to the embodiment of the present invention preferably has a CTE of 30 ppm or less. When the CTE is 30 ppm or less, warping of the support on which the resin film is formed can be suppressed. If the warp is large, it becomes difficult to transport the support during device manufacture, so the smaller the CTE of the resin film, the better. For example, the CTE of the resin film is more preferably 25 ppm or less, still more preferably 20 ppm or less, and particularly preferably 15 ppm or less.

The resin film according to the embodiment of the present invention preferably has a Tg of 400° C. or higher. If the Tg is 400° C. or more, it is possible to suppress wrinkles in the film formed on the resin film in the high-temperature process in the manufacture of electronic devices. A higher Tg of the resin film is preferable because the process temperature for manufacturing the electronic device can be increased. For example, Tg is more preferably 425° C. or higher, even more preferably 450° C. or higher.

CTE and Tg in the present invention are measured using a thermomechanical analyzer. At this time, in the first stage, the sample was heated to 150 ° C. at a temperature increase rate of 5 ° C./min, in the second stage, the sample was air-cooled to room temperature at a temperature decrease rate of 5 ° C./min, and in the third stage , the value obtained by heating the sample at a heating rate of 5° C./min.

The resin film according to the embodiment of the present invention preferably has a 0.1% weight loss temperature (hereinafter referred to as Td _0.1 as appropriate) of 460° C. or higher. Moreover, the higher the Td _0.1 of the resin film, the higher the process temperature for manufacturing electronic devices, which is preferable. If the process temperature for manufacturing electronic devices can be increased, the processing time of the high-temperature process can be shortened, and an electronic device with more excellent reliability can be obtained, which is preferable. For example, Td _0.1 is more preferably 470° C. or higher, even more preferably 475° C. or higher.

Td _0.1 in the present invention is measured using a thermogravimetry device. At this time, in the first stage, the sample was heated to 350 ° C. at a temperature increase rate of 10 ° C./min, in the second stage, the sample was air-cooled to room temperature at a temperature decrease rate of 10 ° C./min, and in the third stage , the value obtained by heating the sample at a heating rate of 10° C./min.

The resin film according to the embodiment of the present invention preferably has a tensile elongation of 5% or more, more preferably 10% or more, and even more preferably 15% or more. The tensile elongation of the resin film is determined according to JISK7127:1999.

<Resin composition>
A resin composition according to an embodiment of the present invention is a resin composition containing a resin having a repeating unit represented by the chemical formula (2) and a solvent. Regarding the resin film obtained by baking for 1 minute, the ratio (H1/H2) of the peak height (H1) including the wave number of 1850 cm ⁻¹ and the peak height (H2) including the wave number of 1775 cm ⁻¹ in IR measurement was 0. 14 or less, it is a resin composition. In the manufacture of electronic devices, heat treatment at 430° C. or higher is usually used as a condition for manufacturing a resin film having heat resistance that can withstand high-temperature processes. Therefore, a resin composition having H1/H2 of 0.14 or less in a resin film obtained by baking at 430° C. for 30 minutes has high heat resistance and transparency and has a large elongation. It is preferable to provide

In chemical formula (2), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms. B represents a diamine residue having 2 or more carbon atoms. However, 30 mol % or more of A is the tetracarboxylic acid residue having the structure represented by the chemical formula (3). R ¹ and R ² each independently represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an alkylsilyl group having 1 to 10 carbon atoms, an alkali metal ion, an ammonium ion, an imidazolium ion or a pyridinium ion .

In chemical formula (3), X ¹ and X ² are each independently a direct bond, an oxygen atom, a sulfur atom, a carbonyl group, a thiocarbonyl group, a sulfonyl group, a structure represented by chemical formula (4), or chemical formula (5) It is a structure represented by

In chemical formulas (4) and (5), Y is a carbon atom, a silicon atom, a boron atom, a nitrogen atom, or a phosphorus atom. n is 1 or 2 and m is an integer of 2-8. Each R ³ is independently a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group. Each Z is independently a structure represented by the chemical formula (6) or a structure represented by the chemical formula (7).

In chemical formulas (6) and (7), R ⁴ to R ⁹ each independently represent a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group.

By using the resin composition according to the embodiment of the present invention, a resin film having a high Tg can be obtained as described above. Further, the resin composition according to the embodiment of the present invention has H1/H2 of 0.14 or less of the resin film obtained by baking at 430° C. for 30 minutes. A resin film with a high degree of hardness can be obtained.

A resin having a repeating unit represented by the chemical formula (2) is a resin that can be converted to a resin having a repeating unit represented by the chemical formula (1) by heat treatment, chemical treatment, or the like. Hereinafter, a resin having such a repeating unit represented by chemical formula (2) is referred to as a "precursor resin". Moreover, a resin composition containing a precursor resin is referred to as a "precursor resin composition". Precursor resins include polyimide precursor resins, polyetherimide precursor resins, polyamideimide precursor resins, and the like.

Specific and preferred examples of A in chemical formula (2) include the structures described as specific and preferred examples of A in chemical formula (1) above. Specific and preferred examples of B in chemical formula (2) include the structures described as specific examples of B in chemical formula (1) above.

In addition, the value obtained by dividing the number of moles of tetracarboxylic acid residues contained in the precursor resin by the number of moles of diamine residues contained in the resin (hereinafter referred to as "division value Kc") is particularly limited. However, 0.900 or more and 1.100 or less is preferable. When the division value Kc is within the above range, the polyimide has a high molecular weight, so that the film tends to have a large elongation. From the viewpoint of the transparency of the resin film to be obtained, the division value Kc is more preferably 1.000 or more and 1.050 or less.

Also, the ends of the precursor resin may be blocked with a terminal blocking agent. When the terminal monomer of the resin is a diamine compound, a dicarboxylic acid anhydride, a monocarboxylic acid, a monocarboxylic acid chloride compound, a monocarboxylic acid active ester compound, a dicarbonic dialkyl ester, or the like is used to block the amino group. can be used as a terminal blocker. When the terminal monomer of the resin is an acid dianhydride, a monoamine, monoalcohol, or the like can be used as a terminal blocking agent to block the acid anhydride group.

The solvent contained in the precursor resin composition can be used without particular limitation as long as it dissolves the precursor resin. Examples of such solvents include N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy- Aprotic polar solvents such as N,N-dimethylpropionamide, N,N-dimethylisobutyramide, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, dimethylsulfoxide, tetrahydrofuran, dioxane Ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol ethyl methyl ether, and diethylene glycol dimethyl ether, ketones such as acetone, methyl ethyl ketone, diisobutyl ketone, diacetone alcohol, and cyclohexanone, Esters such as ethyl acetate, propylene glycol monomethyl ether acetate, ethyl lactate, 3-methyl-3-methoxybutyl acetate, ethylene glycol ethyl ether acetate, 3-methoxybutyl acetate, aromatic hydrocarbons such as toluene and xylene, Examples thereof include solvents described in International Publication No. 2017/099183. As the solvent, any one of these may be used alone, or two or more thereof may be used in combination.

The precursor resin composition may contain an imidization accelerator (i). In this case, the imidization accelerator (i) is preferably contained in an amount of 0.1 parts by mass or more and less than 100 parts by mass with respect to 100 parts by mass of the precursor resin. When a coating film of a precursor resin composition is baked to produce a resin film, depolymerization may occur simultaneously with the imidization reaction during baking. As the depolymerization progresses, the molecular weight of the resin decreases and the terminal structure increases, so the elongation and transparency of the resin film decrease. When the imidization accelerator (i) is included in the above range, the imidization reaction during firing is accelerated, depolymerization is suppressed, and a resin film having a high molecular weight and a small amount of terminal ends can be easily obtained. Therefore, it is presumed that the number of terminal structures that may cause coloration of the resin film is reduced, and a resin film having excellent transparency and high elongation is easily obtained.

As the imidization accelerator (i), for example, a nitrogen atom-containing heterocyclic compound (hereinafter referred to as a "nitrogen-containing heterocyclic compound"), an amine compound, a carboxylic acid compound, a polyhydric phenol compound, or the like can be used. . These compounds may be used individually by 1 type, or may be used in combination of 2 or more type. Among them, a nitrogen-containing heterocyclic compound is preferable because it is difficult to remain in the resin film and a resin film having high heat resistance can be easily obtained. In addition, in the case of a nitrogen-containing heterocyclic compound having a hydroxyl group, each of the hydroxyl group and the nitrogen-containing heterocycle promotes imidation, so the effect of suppressing depolymerization is extremely high, the elongation is particularly large, and the resin has particularly excellent transmittance. It is particularly preferable because a film can be easily obtained.

Examples of nitrogen-containing heterocyclic compounds having a hydroxyl group include 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-hydroxynicotinic acid, 2-hydroxybenzimidazole, 4-hydroxybenzimidazole, 3-amino-4 -hydroxypyridine, 2,4-dihydroxypyridine, 2,6-dimethyl-4-hydroxypyridine, 2,4-dihydroxy-6-methylpyridine, 2-quinolinol, 3-quinolinol, 4-quinolinol, 3-hydroxy-2 -methylpyridine, 5-hydroxy-2-methylpyridine, 2-amino-3-hydroxypyridine, 2,3-dihydroxypyridine and the like.

Examples of other nitrogen-containing heterocyclic compounds include imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 1,2-dimethylimidazole, 3-cyanoimidazole, benzimidazole, pyridine, 4-pyridinemethanol, N,N-dimethylaminopyridine, nicotinaldehyde, isonicotinaldehyde, picolinaldehyde, picolinaldehyde oxime, nicotinaldehyde oxime, isonicotinaldehyde oxime, ethyl picolinate, ethyl nicotinate, ethyl isonicotinate, nicotinamide, isonicotinamide , 2,2′-dipyridyl, 4,4′-dipyridyl, 3-methylpyridazine, quinoline, isoquinoline, phenanthroline, 1,10-phenanthroline, 1,2,4-triazole and the like.

Examples of amine compounds include trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine , N-methylpiperidine, N-ethylpiperidine and the like.

Examples of polyhydric phenol compounds include 3,5-dihydroxyacetophenone, methyl 3,5-dihydroxybenzoate, pyrogallol, methyl gallate, ethyl gallate, naphthalene-1,6-diol, 2,2-bis(4-hydroxyphenyl ) hexafluoropropane, 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)methane and the like.

Carboxylic acid compounds include 4-hydroxyphenylacetic acid, 3-hydroxybenzoic acid, N-acetylglycine, N-benzoylglycine and the like.

The precursor resin composition may contain a silane compound (h). The silane compound (h) is preferably a compound having a structure represented by chemical formula (40).

In chemical formula (40), R ³⁰ and R ³¹ each independently represent a hydrocarbon group having 1 to 20 carbon atoms. k represents an integer of 1 to 4;

When the precursor resin composition contains the silane compound (h), the silane compound (h) condenses to form a siloxane bond during firing of the precursor resin composition. Therefore, siloxane sites are formed in the resin film obtained by baking, so that the light transmittance of the resin film can be further improved.

Examples of compounds having a structure represented by the chemical formula (40) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, methoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 1-naphthyltrimethoxysilane, 2-naphthyltrimethoxysilane, 1-naphthyltriethoxysilane, 2-naphthyltriethoxysilane, dimethyldimethoxysilane, Examples include dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like.

The content of the silane compound (h) is preferably 5 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the precursor resin composition. If the content of the silane compound (h) is 5 parts by mass or more, the light transmittance of the resin film is likely to be improved. If the amount is 100 parts by mass or less, a resin film having good elongation can be easily obtained.

The precursor resin composition may also contain at least one additive selected from (d), an adhesion improver (e), a surfactant (f), and inorganic particles (g), if necessary. . Specific examples of these additives include those described in International Publication No. 2017/099183.

The concentration of the precursor resin in the precursor resin composition is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, with respect to 100 parts by mass of the precursor resin composition. Moreover, 50 mass parts or less are preferable and 40 mass parts or less are more preferable.

The viscosity of the precursor resin composition is preferably 20 to 20,000 mPa·s, more preferably 50 to 10,000 mPa·s.

(Method for producing precursor resin composition)
Next, a method for producing the precursor resin composition will be described. In the method for producing a precursor resin composition, the precursor resin, optionally an imidization accelerator (i), a silane compound (h), an adhesion improver (e), a surfactant (f), and inorganic particles ( g) etc. are dissolved or dispersed in a solvent. Thereby, a varnish, which is one of the precursor resin compositions, can be obtained.

Incidentally, the precursor resin having the repeating unit represented by the chemical formula (2) can be polymerized by a known method. For example, it can be obtained by polymerizing a tetracarboxylic acid, a corresponding acid dianhydride, an active ester, an active amide, or the like as an acid component and a diamine or a corresponding trimethylsilylated diamine as a diamine component in a reaction solvent. . In the precursor resin, the carboxy group forms a salt with an alkali metal ion, ammonium ion or imidazolium ion, or is esterified with a hydrocarbon group having 1 to 10 carbon atoms or an alkylsilyl group having 1 to 10 carbon atoms. It can be anything.

As the reaction solvent, for example, the solvents described as specific examples of the solvent contained in the precursor resin composition can be used singly or in combination of two or more. The amount of the reaction solvent used is preferably adjusted so that the total amount of the tetracarboxylic acid and the diamine compound is 0.1 to 50 parts by mass based on the total amount of the reaction solution. The reaction temperature is preferably -20°C to 150°C, more preferably 0°C to 100°C. Furthermore, the reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

In addition, in the above production method, the corresponding acid dianhydride, active ester, active amide, etc. can also be used as the tetracarboxylic acid. Moreover, the corresponding trimethylsilylated diamine and the like can also be used as the diamine compound. Further, the carboxy group of the resulting resin is esterified with a hydrocarbon group having 1 to 10 carbon atoms or an alkylsilyl group having 1 to 10 carbon atoms, even in the case of salts formed with alkali metal ions, ammonium ions or imidazolium ions. It can be anything.

The obtained precursor resin solution may be used as it is as the precursor resin composition according to the embodiment of the present invention. In this case, the desired precursor resin composition can be obtained without isolating the precursor resin by using the same solvent as the solvent used in the precursor resin composition as the reaction solvent, or by adding a solvent after the reaction is completed. can be obtained.

In the obtained precursor resin, a part of repeating units of amic acid may be further imidized or esterified. In this case, the precursor resin solution obtained by the polymerization of the precursor resin may be directly used for the next reaction, or the precursor resin may be isolated and then used for the next reaction.

In the esterification reaction and imidization reaction of the precursor resin, the same solvent as that used in the precursor resin composition may be used as the reaction solvent, or the solvent may be added after the reaction is completed to convert the precursor resin into a single unit. Without separating, the target precursor resin composition can be obtained.

(Method for manufacturing resin film)
Next, a method for manufacturing a resin film according to an embodiment of the invention will be described. This resin film manufacturing method is an example of a method of manufacturing a resin film according to an embodiment of the present invention from the precursor resin composition described above.

First, a varnish, which is one of the precursor resin compositions according to the embodiments of the present invention, is applied onto a support. Examples of the support include wafer substrates such as silicon and gallium arsenide, glass substrates such as sapphire glass, soda-lime glass and alkali-free glass, metal substrates such as stainless steel and copper, metal foils, and ceramic substrates. Among them, alkali-free glass is preferable from the viewpoint of surface smoothness and dimensional stability during heating.

Examples of the method of applying the varnish include spin coating, slit coating, dip coating, spray coating, printing, and the like, and these may be combined. When the resin film is used as a substrate for display, it is necessary to apply it on a large-sized support, and therefore the slit coating method is preferably used.

After application, the coating film of the varnish is generally dried. As a drying method, reduced pressure drying, heating drying, or a combination thereof can be used. As a method for drying under reduced pressure, for example, a support having a coating film formed thereon is placed in a vacuum chamber, and the coating film is dried by reducing the pressure in the vacuum chamber. Moreover, as a method of drying by heating, a hot plate, an oven, an infrared ray or the like is used to dry the coating film. When a hot plate is used, the support with the coating film formed thereon is held directly on the plate or on a jig such as a proxy pin placed on the plate, and the coating film is dried by heating. The heating temperature varies depending on the type and purpose of the solvent used in the varnish, and heating is preferably carried out at room temperature to 180° C. for 1 minute to several hours.

After that, a heating step is performed in which the coating film on the support is heat-treated to produce a resin film. In this heating step, the coating film is heat-treated at a temperature of 370° C. to 600° C., preferably 400° C. to 500° C., more preferably 410° C. to 480° C. to bake the coating film. Thereby, a resin film can be produced on the support. When the heating temperature (baking temperature) of the coating film in the heating step is 370° C. or higher, the imidization proceeds sufficiently to obtain a resin film having a large elongation. If the heating temperature is 400° C. or higher, a resin film having excellent heat resistance can be obtained. Further, if the heating temperature is 500° C. or less, thermal decomposition of the resin is suppressed, and a resin film having excellent transparency can be obtained.

The resin film obtained through the coating process and the heating process described above can be used after peeling from the support, or can be used as it is without being peeled from the support.

Examples of the peeling method include a mechanical peeling method, a method of immersion in water, a method of immersion in a chemical solution such as hydrochloric acid or hydrofluoric acid, and a method of applying laser light with a wavelength range from ultraviolet light to infrared light between the resin film and the support. and a method of irradiating the interface. In particular, when peeling is performed after a device is formed on a resin film, it is necessary to perform peeling without damaging the device, so peeling using an ultraviolet laser is preferable.

In order to facilitate peeling, the support may be coated with a release agent or a sacrificial layer may be formed before the resin composition is applied to the support. Examples of release agents include silicone-based, fluorine-based, aromatic polymer-based, and alkoxysilane-based agents. Examples of the sacrificial layer include metal films, metal oxide films, amorphous silicon films, and the like.

The resin film according to the embodiment of the present invention is suitably used for display substrates such as organic EL display substrates, color filter substrates, touch panel substrates, electronic paper substrates, μLED display substrates, and particularly flexible display substrates. It is preferably used for Flexible printed circuit boards, solar cell substrates, surface protective films and interlayer insulating films for semiconductor devices, insulating layers and spacer layers for organic electroluminescence devices (organic EL devices), flattening films for thin film transistor substrates, insulating layers for organic transistors , binders for electrodes of lithium-ion secondary batteries, and adhesives for semiconductors.

(display)
Next, a display according to an embodiment of the invention will be described. A display according to an embodiment of the present invention includes a resin film according to an embodiment of the present invention.

A method for manufacturing a display according to an embodiment of the invention is described below.

A configuration example of a display according to an embodiment of the present invention includes a resin film and a display element formed on the resin film.

The resin film is a resin film according to the embodiment of the present invention and functions as a display substrate. A display element is formed on the resin film.

This method of manufacturing a display includes a film manufacturing step of manufacturing a resin film on a support by the method of manufacturing a resin film described above, a step of forming a display element on the resin film, and a step of forming a resin film from the support. and a peeling step of peeling.

First, the resin film according to the embodiment of the present invention is produced on a support according to the method for producing a resin film described above.

An inorganic film may be provided on the resin film as required. By providing the inorganic film, it is possible to prevent moisture and oxygen from passing through the resin film from the outside and cause deterioration of the display element. Examples of the inorganic film include silicon oxide (SiOx), silicon nitride (SiNy), and silicon oxynitride (SiOxNy). These can be used in a single layer or by laminating a plurality of types. These inorganic films are preferably formed by vapor deposition methods such as chemical vapor deposition (CVD) and physical vapor deposition (PVD). These inorganic films can also be used by alternately laminating a plurality of resin films and inorganic films. The resin film laminated on the inorganic film is preferably the resin film according to the embodiment of the present invention. Alternatively, another resin film may be formed on the support, and the inorganic film and the resin film according to the embodiment of the present invention may be alternately laminated on the resin film.

Subsequently, a display element corresponding to the intended display is formed on the obtained resin film or the laminate of the resin film and the inorganic film. For example, when the display is an organic EL display, the organic EL element is formed as the target display element by sequentially forming a TFT as a display element, a first electrode, a light emitting element, a second electrode, and a sealing film. . When the display is a liquid crystal display, a liquid crystal cell is formed by using a first substrate on which a TFT as an image driving element, a first electrode and a first alignment film are formed, and a second substrate on which a second electrode and a second alignment film are formed. is formed and a liquid crystal is injected to form a liquid crystal display element as a desired display element. When the display is a display including a color filter, a color filter element is formed as the target display element by forming a black matrix as necessary and then forming colored pixels such as red, green, and blue. When the display is a display including a touch panel, a touch panel element is formed as the target display element by forming a wiring layer and an insulating layer.

Finally, by peeling the resin film from the support and using the peeled resin film (on which the desired display element is formed), a display containing the resin film of the present invention can be obtained. Methods for peeling at the interface between the support and the resin film include a method using a laser, a mechanical peeling method, and a method of etching the support. In the method using a laser, a support such as a glass substrate is irradiated with a laser from the side where the element is not formed, whereby the separation can be performed without damaging the element. Further, a primer layer may be provided between the substrate and the substrate to facilitate peeling.

EXAMPLES The present invention will be described below with reference to Examples and the like, but the present invention is not limited to the following Examples and the like. First, the measurements, evaluations, tests, etc. performed in the following examples and comparative examples will be described. Note that the number of measurements n is 1 unless otherwise specified.

(First item: measurement of light transmittance of resin film)
For each resin film obtained in each example, a laminate of a resin film and a glass substrate was produced, and the produced laminate was analyzed with an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, MultiSpec 1500), and the resin at a wavelength of 400 nm. The light transmittance of the films was measured.

(Second item: measurement of YI of resin film)
For each resin film obtained in each example, a laminate of a resin film and a glass substrate was produced, and the produced laminate was measured using a spectroscopic haze meter (manufactured by Murakami Color Research Laboratory, HSP-150Vis) and measured according to JIS. YI was measured according to K 7373:2006.

(Third item: measurement of Tg and CTE of resin film)
The Tg and CTE of the resin film (sample) obtained in each example were measured using a thermomechanical analyzer (EXSTAR6000TMA/SS6000, manufactured by SII Nanotechnology Co., Ltd.). At this time, in the first stage, the temperature of the sample was increased to 150° C. at a temperature increase rate of 5° C./min, thereby removing the adsorbed water of this sample. In the subsequent second stage, the sample was air-cooled to room temperature at a cooling rate of 5°C/min. In the subsequent third step, the sample was heated at a heating rate of 5°C/min and the Tg and CTE of the sample were measured. CTE was obtained in the temperature range of 50° C. to 150° C. during the temperature rising process of the third stage.

(Fourth item: measurement of Td _0.1 and 0.5% weight loss temperature (hereinafter referred to as Td _0.5 as appropriate) of the resin film)
Td _0.1 and Td _0.5 were measured for the resin film (sample) obtained in each example using a thermogravimetric analyzer (manufactured by Shimadzu Corporation, TGA-50). At this time, in the first stage, the sample was heated to 350° C. at a heating rate of 10° C./min, thereby removing the adsorbate of this sample. In the subsequent second step, the sample was air-cooled to room temperature at a cooling rate of 10°C/min. In the subsequent third step, Td _0.1 and Td _0.5 of the samples were measured at a heating rate of 10°C/min.

(Item 5: IR measurement of resin film)
The resin film (sample) obtained in each example was subjected to IR measurement using a Fourier transform infrared spectrophotometer (manufactured by JASCO Corporation, FT/IR-4600). The measurement was performed by the ATR method, the ATR crystal was diamond, and the incident angle was 45 degrees. From the obtained IR spectrum, the ratio (H1/H2) of the peak height (H1) containing a wavenumber of 1850 cm ⁻¹ and the peak height (H2) containing a wavenumber of 1775 cm ⁻¹ was calculated.

(Item 6: Measurement of tensile elongation of resin film)
The resin film (sample) obtained in each example was measured using a Tensilon universal material testing machine (RTM-100 manufactured by Orientec Co., Ltd.) according to Japanese Industrial Standards (JIS K 7127:1999).

The measurement conditions were a test piece width of 10 mm, a chuck interval of 50 mm, a test speed of 50 mm/min, and a side constant of n=10.

(Compound)
In Examples and Comparative Examples, the compounds shown below are appropriately used. Each compound and its abbreviation are as shown below.
PDA: p-phenylenediamine DDS: 4,4'-diaminodiphenylsulfone DAN: 1,5'-diaminonaphthalene TFMB: 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl mTB: 4, 4′-Diamino-2,2′-dimethylbiphenyl BPDA: 3,3′,4,4′-biphenyltetracarboxylic dianhydride SFDA: In the chemical formula (3), X ¹ is an oxygen atom and X ² is Tetracarboxylic dianhydride ODPA having a structure represented by chemical formula (9): 4,4'-oxydiphthalic anhydride 4HPy: 4-hydroxypyridine 1MeIm: 1-methylimidazole NMP: N-methyl-2-pyrrolidone.

(Synthesis example 1)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (8.32 g (76.9 mmol)) was added while stirring, and after confirming dissolution, SFDA (36.69 g (77.7 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (2.25 g) was added. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis example 2)
A resin composition (varnish) was obtained in the same manner as in Synthesis Example 1, except that the weight of 4HPy was changed to 4.5 g.

(Synthesis Example 3)
A resin composition (varnish) was obtained in the same manner as in Synthesis Example 1, except that the weight of 4HPy was changed to 18.0 g.

(Synthesis Example 4)
A resin composition (varnish) was obtained in the same manner as in Synthesis Example 2, except that 4HPy was changed to 1MeIm.

(Synthesis Example 5)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (9.48 g (87.7 mmol)) was added while stirring, and after confirming that it was dissolved, SFDA (25.10 g (53.1 mmol)) and BPDA (10.42 g (35.1 mmol)) were added. 4 mmol)) was introduced. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (4.5 g) was added. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 6)
Synthesis Example 5 except that the weight of PDA was changed to 10.20 g (94.3 mmol), the weight of SFDA was changed to 17.99 g (38.1 mmol), and the weight of BPDA was changed to 16.81 g (57.1 mmol). A resin composition (varnish) was obtained in the same manner as above.

(Synthesis Example 7)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (5.49 g (50.8 mmol)) and DDS (5.23 g (21.0 mmol)) were added while stirring, and after confirming that they were dissolved, SFDA (34.28 g (72.0 mmol)) was added. 6 mmol)) was introduced. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (4.5 g) was added. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 8)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (3.75 g (34.7 mmol)) and DDS 8.45 g (34.0 mmol) were added while stirring, and after confirming that they were dissolved, SFDA (32.80 g (69.4 mmol)) was added. was put in. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (18 g) was added. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 9)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, DAN (11.20 g (70.8 mmol)) was added while stirring, and after confirming dissolution, SFDA (33.80 g (71.5 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (18 g) was added. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 10)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, TFMB (18.04 g (56.5 mmol)) was added while stirring, and after confirming dissolution, SFDA (26.96 g (57.1 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (4.5 g) was added. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 11)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, mTB (13.86 g (65.3 mmol)) was added while stirring, and after confirming dissolution, SFDA (31.14 g (65.9 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (4.5 g) was added. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 12)
A resin composition (varnish) was obtained in the same manner as in Synthesis Example 2, except that the weight of PDA was changed to 8.45 g (78.1 mmol) and the weight of SFDA was changed to 36.55 g (77.4 mmol).

(Synthesis Example 13)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (8.32 g (76.9 mmol)) was added while stirring, and after confirming dissolution, SFDA (36.69 g (77.7 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 14)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (10.20 g (94.3 mmol)) was added while stirring, and after confirming that it was dissolved, SFDA (17.99 g (38.1 mmol)) and BPDA (16.81 g (57.1 mmol)) were added. 1 mmol)) was introduced. After stirring for 12 hours, the reaction solution was cooled to room temperature. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 15)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (5.49 g (50.8 mmol)) and DDS (5.23 g (21.0 mmol)) were added while stirring, and after confirming that they were dissolved, SFDA (34.28 g (72.0 mmol)) was added. 6 mmol)) was introduced. After stirring for 12 hours, the reaction solution was cooled to room temperature. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 16)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, DAN (11.20 g (70.8 mmol)) was added while stirring, and after confirming dissolution, SFDA (33.80 g (71.5 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 17)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, TFMB (18.04 g (56.5 mmol)) was added while stirring, and after confirming dissolution, SFDA (26.96 g (57.1 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 18)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, mTB (13.86 g (65.3 mmol)) was added while stirring, and after confirming dissolution, SFDA (31.14 g (65.9 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 19)
A resin composition (varnish) was obtained in the same manner as in Synthesis Example 13, except that the weight of PDA was changed to 8.45 g (78.1 mmol) and the weight of SFDA was changed to 36.55 g (77.4 mmol).

(Synthesis Example 20)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (12.01 g (111.0 mmol)) was added while stirring, and after confirming that it was dissolved, BPDA (32.99 g (112.1 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 21)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (12.01 g (111.0 mmol)) was added while stirring, and after confirming that it was dissolved, BPDA (32.99 g (112.1 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (2.25 g) was added. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

(Synthesis Example 22)
A thermometer and a stirring bar with stirring blades were set in a 500 mL four-necked flask. Next, NMP (255 g) was added under a dry nitrogen stream, and the temperature was raised to 60°C. After raising the temperature, PDA (11.55 g (106.8 mmol)) was added while stirring, and after confirming dissolution, ODPA (33.45 g (107.8 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature. After diluting with NMP, the mixture was filtered through a filter with a pore size of 0.2 μm to obtain a resin composition (varnish).

Tables 1 and 2 show the composition of each resin composition (varnish) obtained in Synthesis Examples 1 to 22.

(Example 1)
Using a slit coating device (manufactured by Toray Engineering Co., Ltd.), the resin composition of Synthesis Example 1 (varnish ) was applied to an area 5 mm inside from the edge of the glass substrate. Subsequently, heat vacuum drying was performed at a temperature of 40° C. using the same apparatus. Finally, using a gas oven (INH-21CD manufactured by Koyo Thermo Systems Co., Ltd.), in a nitrogen atmosphere (oxygen concentration of 100 ppm or less), heat at 430 ° C. for 30 minutes to form a resin film with a thickness of 10 μm on the glass substrate. bottom. For the obtained resin film on the substrate, the light transmittance of the resin film was measured by the method of the first item above, and the YI was measured by the method of the second item above.

Subsequently, the glass substrate was irradiated with a laser (wavelength: 308 nm) from the side where the resin film was not formed, and peeling was performed at the interface with the resin film. For the obtained resin film, Tg and CTE were measured by the method of the third item above, Td _0.1 and Td _0.5 were measured by the method of the fourth item above, and tensile elongation was measured by the method of the sixth item above. degree was measured. In addition, IR measurement is performed by the method of item 5 above, and the ratio (H1/H2) of the height (H1) of the peak containing the wave number of 1850 cm ^-1 and the height (H2) of the peak containing the wave number of 1775 cm ^-1 is calculated. bottom.

(Examples 2-14 and Comparative Examples 1-10)
In Examples 2 to 14 and Comparative Examples 1 to 10, the resin compositions (varnishes) of Synthesis Examples 1 to 22 shown in Tables 1 and 2 were used, and the same evaluation as in Example 1 was performed.

In Example 12, the same evaluation as in Example 2 was performed, except that the heating conditions were changed from 430°C to 350°C.

In Example 13, the same evaluation as in Example 2 was performed, except that the heating conditions were changed from 430°C to 460°C.

Evaluation results of Examples 1 to 14 and Comparative Examples 1 to 10 are shown in Table 3.

In Examples 1 to 14, a resin film having (H1/H2) of 0.14 or less was obtained, so that the light transmittance at a wavelength of 400 nm was high, the YI was low, the transparency was excellent, the Tg was high, and the heat resistance was excellent. The result was that it was excellent and had a large elongation.

In Comparative Examples 1 to 7, a resin film having (H1/H2) exceeding 0.14 was obtained, and thus the elongation was small. Moreover, in Comparative Examples 1, 2, 4, 6 and 7, the light transmittance at a wavelength of 400 nm was low, the YI was high, and the transparency was poor. In Comparative Examples 3 and 5, although the transparency was higher than the other comparative examples, the elongation was small as described above, and it was not suitable for use in flexible electronic devices that require heat resistance and transparency. .

In Comparative Examples 8 to 10, resin films in which (H1/H2) was 0.14 or less were obtained, but 30 mol% or more of A was a tetracarboxylic acid residue having a structure represented by chemical formula (3). Therefore, it was inferior in at least one of transmittance and heat resistance.

(Example 101)
A gas barrier film composed of lamination of SiO ₂ and Si ₃ N ₄ was formed by CVD on the resin film on the glass substrate obtained in Example 2. Subsequently, a TFT was formed, and an insulating film made of Si ₃ N ₄ was formed to cover the TFT. The maximum heating temperature during TFT formation was 450° C., and the heating time was 2 hours. Next, after forming a contact hole in this insulating film, a wiring connected to the TFT was formed through this contact hole.

Furthermore, a planarizing film was formed to planarize unevenness due to the formation of the wiring. Next, a first electrode made of ITO was formed on the resulting flattened film by connecting it to wiring. Thereafter, a resist was applied, prebaked, exposed through a mask having a desired pattern, and developed. Using this resist pattern as a mask, pattern processing was performed by wet etching using an ITO etchant. Thereafter, the resist pattern was stripped using a resist stripping solution (mixed solution of monoethanolamine and diethylene glycol monobutyl ether). The substrate after peeling was washed with water and dehydrated by heating to obtain an electrode substrate with a flattening film. Next, an insulating film was formed to cover the periphery of the first electrode.

Furthermore, a hole-transporting layer, an organic light-emitting layer, and an electron-transporting layer were sequentially deposited through a desired pattern mask in a vacuum deposition apparatus. Next, a second electrode made of Al/Mg was formed on the entire upper surface of the substrate. Furthermore, a sealing film consisting of a lamination of SiO ₂ and Si ₃ N ₄ was formed by CVD. Finally, the glass substrate was irradiated with a laser (wavelength: 308 nm) from the side where the resin film was not formed, and peeling was performed at the interface with the resin film. The irradiation energy at this time was 200 mJ/cm ² .

As described above, an organic EL display device formed on a resin film was obtained. When a voltage was applied through a drive circuit, good light emission was observed.

(Example 102)
Evaluation was performed in the same manner as in Example 101 except that the resin film on the glass substrate obtained in Example 2 was changed to the resin film on the glass substrate obtained in Example 12. However, when the TFT was heated at 450° C., the gas barrier film floated, and a normal TFT could not be formed. Therefore, the maximum heating temperature during TFT formation was changed from 450° C. to 430° C., the heating time was changed from 2 hours to 3 hours, and the subsequent operations were evaluated in the same manner as in Example 101. was obtained, and when a voltage was applied through a driving circuit, good light emission was exhibited.

(Comparative Example 101)
Evaluation was performed in the same manner as in Example 101 except that the resin film on the glass substrate obtained in Example 2 was changed to the resin film on the glass substrate obtained in Comparative Example 10. However, when the TFT was heated at 450° C., wrinkles occurred in the gas barrier film, and a normal TFT could not be formed. Therefore, the maximum heating temperature during TFT formation was changed from 450° C. to 430° C., and the heating time was changed from 2 hours to 3 hours. rice field.

Claims (11)

including a resin having a repeating unit represented by the chemical formula (1),
A resin film having a ratio (H1/H2) of a peak height (H1) including a wavenumber of 1850 cm ⁻¹ to a peak height (H2) including a wavenumber of 1775 cm ⁻¹ in IR measurement of 0.14 or less.

(In the chemical formula (1), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms. B represents a diamine residue having 2 or more carbon atoms. However, 30 mol% or more of A is the chemical formula (3 ) is a tetracarboxylic acid residue having a structure represented by

In chemical formula (3), X ¹ and X ² are each independently a direct bond, an oxygen atom, a sulfur atom, a carbonyl group, a thiocarbonyl group, a sulfonyl group, a structure represented by chemical formula (4), or chemical formula (5) It is a structure represented by

In chemical formulas (4) and (5), Y is a carbon atom, a silicon atom, a boron atom, a nitrogen atom, or a phosphorus atom. n is 1 or 2 and m is an integer of 2-8. Each R ³ is independently a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group. Each Z is independently a structure represented by the chemical formula (6) or a structure represented by the chemical formula (7).

In chemical formulas (6) and (7), R ⁴ to R ⁹ each independently represent a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group. ) 2. The resin film according to claim 1, wherein the resin film has a 0.1% weight loss temperature of 460[deg.] C. or higher. In chemical formula (3), X ¹ and X ² are each independently an oxygen atom, a sulfur atom, a structure represented by chemical formula (4) or a structure represented by chemical formula (5), and chemical formula (4) and In chemical formula (5), each R ³ is independently an aromatic hydrocarbon group or aromatic heterocyclic group having 1 to 10 carbon atoms, and Z is a structure represented by chemical formula (6). The resin film according to claim 1 or 2. 3. The resin film according to claim ¹ , wherein in chemical formula ( ³ ), X1 is an oxygen atom and X2 is a structure represented by chemical formula (9).

3. The resin film according to claim 1, which is used as a display substrate. A resin film containing a resin having a repeating unit represented by the chemical formula (2) and a solvent, coated with the resin composition, and baked at 430 ° C. for 30 minutes includes a wave number of 1850 cm ^-1 in IR measurement. A resin composition having a ratio (H1/H2) of a peak height (H1) to a peak height (H2) including a wave number of 1775 cm ⁻¹ of 0.14 or less.

(In the chemical formula (2), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms. B represents a diamine residue having 2 or more carbon atoms. However, 30 mol% or more of A is the chemical formula (3 ), wherein R ¹ and R ² are each independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an alkylsilyl group having 1 to 10 carbon atoms, Alkali metal ions, ammonium ions, imidazolium ions or pyridinium ions.

In chemical formula (3), X ¹ and X ² are each independently a direct bond, an oxygen atom, a sulfur atom, a carbonyl group, a thiocarbonyl group, a sulfonyl group, a structure represented by chemical formula (4), or chemical formula (5) It is a structure represented by

In chemical formulas (4) and (5), Y is a carbon atom, a silicon atom, a boron atom, a nitrogen atom, or a phosphorus atom. n is 1 or 2 and m is an integer of 2-8. Each R ³ is independently a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group. Each Z is independently a structure represented by the chemical formula (6) or a structure represented by the chemical formula (7).

In chemical formulas (6) and (7), R ⁴ to R ⁹ each independently represent a hydrogen atom, a halogen atom, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms, or an aromatic heterocyclic group. ) 7. The resin composition according to claim 6, containing 0.1 parts by mass or more and less than 100 parts by mass of the imidization accelerator with respect to 100 parts by mass of the resin. 8. The resin composition according to claim 7, wherein the imidization accelerator is a nitrogen atom-containing heterocyclic compound. 9. The resin composition according to claim 8, wherein said imidization accelerator is a heterocyclic compound further containing a hydroxyl group. A method for producing a resin film, comprising the step of applying the resin composition according to any one of claims 6 to 9 to a support and baking it at 400°C or higher and 500°C or lower. forming a resin film on a support by the method for producing a resin film according to claim 10; forming a display element on the resin film; peeling the resin film from the support; A method of manufacturing a display, comprising: