Resin film, method for producing the same, resin composition, display and method for producing the same

Abstract

To provide a resin film having high transparency and high thermostability and also having low CTE.SOLUTION: A resin film comprises a resin having a repeat unit represented by a predetermined chemical structure and has a yellowness of 18 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a resin film, a method for producing the same, a resin composition, a display, and a method for producing the same. [Background technology]

[0002] Due to its excellent electrical insulation, heat resistance, and mechanical properties, polyimide is used as a material for various electronic devices, such as semiconductors and displays. Recently, by using polyimide films as substrates for displays such as organic EL displays, electronic paper, and color filters, it has become possible to manufacture impact-resistant and flexible displays.

[0003] Materials used in electronic devices require high heat resistance to withstand the high-temperature processes involved in device manufacturing. Especially in applications requiring transparency, materials that offer both heat resistance and transparency are needed. Furthermore, a high coefficient of linear thermal expansion (CTE) of the resin film leads to increased warping of the support structure, worsening process passability; therefore, a low CTE of the resin film is required.

[0004] For example, Patent Document 1 discloses an example of manufacturing an organic EL display using a polyimide with high heat resistance as a substrate. Patent Document 2 also discloses an example of a highly transparent polyimide film having a naphthalene skeleton that can be used as a display substrate. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2017 / 099183 [Patent Document 2] International Publication No. 2014 / 162734 [Overview of the project] [Problems that the invention aims to solve]

[0006] The polyimide resin film described in Patent Document 1 had the problem that it could not be applied to applications requiring transparency because the light transmittance of the resin film was insufficient.

[0007] The polyimide resin film described in Patent Document 2 had the problem of not having the heat resistance necessary to withstand the high-temperature processes used in the manufacturing of electronic devices.

[0008] Therefore, the present invention aims to provide a resin film that has high transparency and high heat resistance, and low CTE. [Means for solving the problem]

[0009] The present invention relates to a resin film comprising a resin having repeating units represented by chemical formula (1), wherein the degree of yellowness (hereinafter referred to as YI as appropriate) is 18 or less.

[0010] [ka]

[0011] 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, in 80 mol% or more of the repeating unit represented by chemical formula (1) contained in the resin, B is an alicyclic diamine residue or an aromatic diamine residue, and in 30 mol% or more, B is a diamine residue of the structure represented by chemical formula (3), (4), or (5).

[0012] [ka]

[0013] In Chemical Formulas (3) and (4), two of the α's are amino groups. The remaining α, and β, γ, and δ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, or a hydrocarbon group having 1 to 10 carbon atoms, provided that the cases where all of β are hydrogen atoms and where all of γ are hydrogen atoms are excluded. n is 1 or 2.

[0014] In Chemical Formula (5), Y is a direct bond, an ether group, an ester group, an amide group, a sulfonyl group, or a hydrocarbon group having 1 to 20 carbon atoms. Z is each independently a structure represented by Chemical Formula (6) or (7).

[0015]

Chemical Formula

[0016] In Chemical Formulas (6) and (7), one of the α's is an amino group. One of the remaining α and ε is bonded to Y. The remaining α, the remaining ε, and β are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, or a hydrocarbon group having 1 to 10 carbon atoms. n is 1 or 2, provided that the case where all of β are hydrogen atoms is excluded.

[0017] Further, the present invention is a resin composition containing a resin having a repeating unit represented by Chemical Formula (2) and a solvent, and the resin composition has a YI of 18 or less for a resin film obtained by applying the resin composition and firing it at 430°C for 30 minutes.

[0018]

Chemical Formula

[0019] In chemical formula (2), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms, and B represents a divalent diamine residue having 2 or more carbon atoms. However, in 80 mol% or more of the repeating unit represented by chemical formula (2) contained in the resin, B consists of an alicyclic or aromatic diamine residue, and in 30 mol% or more, B is a diamine residue with the structure represented by chemical formula (3), (4), or (5). 1 and R 2 Each of these 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.

[0020] [ka]

[0021] In chemical formulas (3) and (4), two of the α groups are amino groups. The remaining α and β, γ and δ are, independently, hydrogen atoms, halogen atoms, hydroxyl groups, carboxyl groups, or hydrocarbon groups having 1 to 10 carbon atoms, except when all β are hydrogen atoms or when all γ are hydrogen atoms. n is either 1 or 2.

[0022] In chemical formula (5), Y is a direct bond, an ether group, an ester group, an amide group, a sulfonyl group, or a hydrocarbon group having 1 to 20 carbon atoms. Z is independently a structure represented by chemical formula (6) or (7).

[0023] [ka]

[0024] In chemical formulas (6) and (7), one of the α groups is an amino group. One of the remaining α and ε groups is bonded to Y. The remaining α, the remaining ε, and β groups are, independently, a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms. n is 1 or 2, except when all β groups are hydrogen atoms. [Effects of the Invention]

[0025] The resin film according to the present invention has a high glass transition temperature (hereinafter referred to as Tg as appropriate), excellent heat resistance, and a low YI, resulting in excellent transparency. Therefore, it can be suitably used in applications requiring transparency and heat resistance. Furthermore, because of its low CTE, warping of the support on which the resin film is formed is suppressed, resulting in excellent process passability during the manufacturing of electronic devices. [Modes for carrying out the invention]

[0026] The embodiments for carrying out the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below and can be implemented in various ways depending on the purpose and application.

[0027] <Resin film> The resin film according to the embodiment of the present invention is a resin film comprising a resin having repeating units represented by chemical formula (1), wherein YI is 18 or less.

[0028] [ka]

[0029] 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, in 80 mol% or more of the repeating unit represented by chemical formula (1) contained in the resin, B is an alicyclic diamine residue or an aromatic diamine residue, and in 30 mol% or more, B is a diamine residue of the structure represented by chemical formula (3), (4), or (5).

[0030] [ka]

[0031] In chemical formulas (3) and (4), two of the α groups are amino groups. The remaining α, along with β, γ, and δ, are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms, except when β is all hydrogen atoms or when γ is all hydrogen atoms. n is either 1 or 2.

[0032] In chemical formula (5), Y is a direct bond, an ether group, an ester group, an amide group, a sulfonyl group, or a hydrocarbon group having 1 to 20 carbon atoms. Z is independently a structure represented by chemical formula (6) or (7).

[0033] [ka]

[0034] In chemical formulas (6) and (7), one of the α groups is an amino group. One of the remaining α and ε groups is bonded to Y. The remaining α, the remaining ε, and β groups are, independently, a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms. n is 1 or 2, except when all β groups are hydrogen atoms.

[0035] Examples of resins having repeating units represented by chemical formula (1) include polyimide resins, polyetherimide resins, and polyamideimide resins.

[0036] The resin film according to the embodiment of the present invention contains a diamine residue having a structure represented by chemical formula (3), (4), or (5). Since resin films containing these structures have high light transmittance, they can be suitably used in applications requiring transparency.

[0037] The reason why the light transmittance of the resin film increases when it contains the above structure is presumed to be as follows: In most high heat-resistant polyimides, the highest occupied orbital (hereinafter referred to as HOMO as appropriate) is predominantly located in the diamine region, and the lowest unoccupied orbital (hereinafter referred to as LUMO as appropriate) is predominantly located in the dianhydride region. This HOMO-LUMO transition from the diamine region to the dianhydride region is a charge transfer transition and is one of the causes of coloration in polyimides.

[0038] In the structures represented by chemical formulas (3) and (6), when the amino group in the structure forms an imide bond, β acts as steric hindrance to the oxygen atom of the imide bond. Similarly, in the structures represented by chemical formulas (4) and (7), when the amino group in the structure forms an imide bond, another α acts as steric hindrance to the oxygen atom of the imide bond. Therefore, in resin films containing these structures, the imide group and the diamine moiety cannot exist in the same plane due to the aforementioned steric hindrance, resulting in a large dihedral angle between them. This is presumed to suppress the transition from HOMO to LUMO, preventing discoloration and increasing light transmittance.

[0039] Furthermore, in the resin film according to the embodiment of the present invention, B is an alicyclic diamine residue or an aromatic diamine residue in 80 mol% or more of the repeating unit represented by chemical formula (1) contained in the resin. Since resin films containing these structures have excellent heat resistance, they have excellent process passability in high-temperature processes during the manufacture of electronic devices.

[0040] The resin film according to the embodiment of the present invention has a YI of 18 or less, and is therefore suitable for use in applications requiring transparency. A smaller YI value of the resin film is preferable because it results in better transparency. For example, a YI of 15 or less is more preferable, and 12 or less is even more preferable. In the present invention, the yellowness of the resin film is determined in accordance with JIS K 7373:2006.

[0041] In chemical formula (1), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms, and it is preferable that such a tetracarboxylic acid residue is a tetravalent hydrocarbon group having 2 to 80 carbon atoms. Alternatively, A may be a tetravalent organic group having 2 to 80 carbon atoms, with hydrogen and carbon as essential components and containing one or more atoms selected from boron, oxygen, sulfur, nitrogen, phosphorus, silicon, and halogen. The number of each atom of boron, oxygen, sulfur, nitrogen, phosphorus, silicon, and halogen contained in this organic group is preferably in the range of 20 or less, and more preferably in the range of 10 or less.

[0042] There are no particular restrictions on the tetracarboxylic acid that gives A, and known ones can be used. Examples include aromatic tetracarboxylic acids such as 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, and bis(trimellitic acid monoester) compounds, as well as aliphatic tetracarboxylic acids such as alicyclic tetracarboxylic acids and linear aliphatic tetracarboxylic acids.

[0043] Examples of aromatic tetracarboxylic acids include pyromellitic acid, 3,3',4,4'-biphenyltetracarboxylic acid having the structure represented by chemical formula (9), 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-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)ether, and 9,9-bis(3,4-dicarboxyphenyl)fluorene.

[0044] [ka]

[0045] Examples of alicyclic tetracarboxylic acids include, for example, cyclobutanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, dicyclohexyl-3,3',4,4'-tetracarboxylic acid, and tetracarboxylic acids having the structure represented by chemical formulas (33), (34), or (35).

[0046] [ka]

[0047] In chemical formula (33), p represents an integer from 0 to 3. In chemical formula (34), q represents an integer from 1 to 4. In chemical formula (35), r represents an integer from 0 to 2.

[0048] Examples of chain-like aliphatic tetracarboxylic acids include, for example, butanetetracarboxylic acid.

[0049] Furthermore, examples of tetracarboxylic acids that yield A include the tetracarboxylic acids described in International Publication No. 2017 / 099183.

[0050] These tetracarboxylic acids can be used as raw materials to give A in their original form, or in the form of acid anhydrides, active esters, or active amides, and two or more of these may also be used.

[0051] From the viewpoint of obtaining a resin film with higher heat resistance, it is preferable that A is an alicyclic tetracarboxylic acid residue or an aromatic tetracarboxylic acid residue in 80 mol% or more of the repeating units represented by chemical formula (1) contained in the resin. Furthermore, from the viewpoint of further improving YI, it is preferable that the repeating units in which A is an alicyclic tetracarboxylic acid residue in chemical formula (1) contained in the resin amount to 20 mol% or more, and more preferably 50 mol% or more. In addition, from the viewpoint of achieving both transparency and low CTE, it is particularly preferable that the alicyclic tetracarboxylic acid residue is a tetracarboxylic acid residue with a structure represented by chemical formula (33), (34), or (35).

[0052] Furthermore, as the tetracarboxylic acid that provides A, silicon-containing tetracarboxylic acids such as dimethylsilane diphthalic acid and 1,3-bis(phthalate)tetramethyldisiloxane may be used to improve the coating properties on the support when manufacturing the resin film and to enhance resistance to oxygen plasma and UV ozone treatment used for cleaning when forming elements on the resin film. When using these silicon-containing tetracarboxylic acids, it is preferable to use 1 to 30 mol% of the total tetracarboxylic acid.

[0053] In the tetracarboxylic acid exemplified above, some of the hydrogen atoms in the tetracarboxylic acid residue may be substituted with C1-C10 hydrocarbon groups such as methyl groups and ethyl groups, C1-C10 fluoroalkyl groups such as trifluoromethyl groups, or groups such as F, Cl, Br, and I. Furthermore, if some of the hydrogen atoms in the residue are substituted with acidic groups such as OH, COOH, SO3H, CONH2, and SO2NH2, the solubility of the resin precursor in an alkaline aqueous solution is improved, which is preferable when used as a photosensitive resin composition as described later.

[0054] In chemical formula (1), B represents a divalent diamine residue having 2 or more carbon atoms, and such diamine residue is preferably a divalent hydrocarbon group having 2 to 80 carbon atoms. Alternatively, B may be a divalent organic group having 2 to 80 carbon atoms, with hydrogen and carbon as essential components and containing one or more atoms selected from boron, oxygen, sulfur, nitrogen, phosphorus, silicon, and halogen. The number of each atom of boron, oxygen, sulfur, nitrogen, phosphorus, silicon, and halogen contained in this organic group is preferably in the range of 20 or less, and more preferably in the range of 10 or less.

[0055] From the viewpoint of obtaining a resin film with higher heat resistance, it is preferable that B is an alicyclic diamine residue or an aromatic diamine residue in 90 mol% or more of the repeating unit represented by chemical formula (1) contained in the resin.

[0056] Examples of alicyclic diamines include cyclohexanediamine and 4,4'-methylenebis(cyclohexylamine).

[0057] Examples of aromatic diamines include monocyclic aromatic diamine compounds, naphthalene or condensed polycyclic aromatic diamine compounds, bis(diaminophenyl) compounds or their various derivatives, 4,4'-diaminobiphenyl or its various derivatives, bis(aminophenoxy) compounds, bis(3-amino-4-hydroxyphenyl) compounds, bis(aminobenzoyl) compounds, heterocyclic diamine compounds, or compounds in which some of the hydrogen atoms bonded to the aromatic ring in these diamine compounds are replaced with hydrocarbons or halogens.

[0058] Specific examples of aromatic diamines include, for example, m-phenylenediamine, p-phenylenediamine, 3,5-diaminobenzoic acid, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-di(trifluoromethyl)-4,4'-diaminobiphenyl, bis(4-aminophenoxyphenyl)sulfone, bis(3-aminophenoxyphenyl)sulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, and 1,3-bis Examples include (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'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, and 4-aminophenyl 4-aminobenzoic acid.

[0059] Furthermore, diamines with structures represented by chemical formulas (3), (4), or (5) are also included in aromatic diamines.

[0060] Examples of diamines with the structure represented by chemical formula (3) include, for example, 2,5-dimethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 2,5-difluoro-1,4-phenylenediamine, 2,3,5,6-tetrafluoro-1,4-phenylenediamine, 2,5-dichloro-1,4-phenylenediamine, 2,3,5,6-tetrachloro-1,4-phenylenediamine, and 2,5-diaminoterephthalic acid.

[0061] Examples of diamines with the structure represented by chemical formula (4) include, for example, 1,4-naphthalenediamine, 1,8-naphthalenediamine, 1,4-anthracenediamine, 1,5-anthracenediamine, 1,8-anthracenediamine, 9,10-anthracenediamine, and diamines with the structure represented by chemical formula (8).

[0062] [ka]

[0063] In chemical formula (8), α and δ are, independently, a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms. Examples of diamines represented by chemical formula (8) include, for example, 1,5-naphthalenediamine, 2-methylnaphthalene-1,5-diamine, 4-methylnaphthalene-1,5-diamine, 2,6-dimethylnaphthalene-1,5-diamine, 1,5-diamino-2,6-dihydroxynaphthalene, and 1,5-diamino-2-naphthalenecarboxylic acid.

[0064] Examples of diamines with the structure represented by chemical formula (5) include, for example, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-3,3',5,5'-tetramethylbiphenyl, 1,1'-binaphthalene-4,4'-diamine, 3,3'-dimethyl-1,1'-binaphthalene-4,4'-diamine, 4,4'-oxybis(naphthalene-1-amine), 4,4'-methylenebis(naphthalene-1-amine), 9,9'-bianthracene-10,10'-diamine, and 10,10'-oxybis(anthracene-1-amine).

[0065] Preferably, in 30 mol% or more of the repeating unit represented by chemical formula (1) contained in the resin, B is a diamine residue having the structure represented by chemical formula (4) or chemical formula (5), in chemical formula (5) Z is the structure represented by chemical formula (7), and in chemical formulas (4) and (7) n is 1. If B has these structures, the resin film tends to have a high Tg and superior heat resistance.

[0066] Furthermore, in 30 mol% or more of the repeating unit represented by chemical formula (1) contained in the resin, B is more preferably a diamine residue of the structure represented by chemical formula (8), and particularly preferably a 1,5-diaminonaphthalene residue. If B has these structures, the resin film will have better transparency and heat resistance, and the CTE will tend to be lower.

[0067] Furthermore, from the viewpoint of low CTE, it is even more preferable that B is a diamine residue of the structure represented by chemical formula (8) in 50 mol% or more of the repeating unit represented by chemical formula (1) contained in the resin.

[0068] There are no particular restrictions on the other diamines that give B, and known ones can be used. Examples include aliphatic diamines such as linear aliphatic diamine compounds.

[0069] Examples of linear aliphatic diamines include ethylenediamine, propylenediamine, butanediamine, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, and 1,4-bis(aminomethyl)cyclohexane.

[0070] Furthermore, examples of diamines that provide B include those described in International Publication No. 2017 / 099183.

[0071] These diamines can be used as diamines that yield B, either in their original form or as corresponding trimethylsilylated diamines, and two or more of these may also be used.

[0072] Particularly preferred is that in 50 mol% or more of the repeating units represented by chemical formula (1) contained in the resin, A is an alicyclic tetracarboxylic acid residue and B is a diamine residue with the structure represented by chemical formula (8). Most preferred is that in 50 mol% or more of the repeating units represented by chemical formula (1) contained in the resin, A is an alicyclic tetracarboxylic acid residue and B is a 1,5-diaminonaphthalene residue. When A and B have these structures, a resin film with superior heat resistance and transparency, and a lower CTE, is more likely to be obtained.

[0073] Furthermore, as the diamine that provides B, silicon-containing diamines such as 1,3-bis(3-aminopropyl)tetramethyldisiloxane and 1,3-bis(4-anilino)tetramethyldisiloxane may be used to improve the coating properties on the support when manufacturing the resin film and to enhance resistance to oxygen plasma and UV ozone treatment used for cleaning when forming elements on the resin film. When using these silicon-containing diamine compounds, it is preferable to use 1 to 30 mol% of the total diamine compound.

[0074] In the diamine compounds exemplified above, some of the hydrogen atoms in the diamine compound may be substituted with C1-C10 hydrocarbon groups such as methyl groups and ethyl groups, C1-C10 fluoroalkyl groups such as trifluoromethyl groups, or groups such as F, Cl, Br, and I. Furthermore, if some of the hydrogen atoms in the diamine compound are substituted with acidic groups such as OH, COOH, SO3H, CONH2, and SO2NH2, the solubility of the resin precursor in an alkaline aqueous solution is improved, which is preferable when used as a photosensitive resin composition as described later.

[0075] There are no particular restrictions on the value obtained by dividing the number of moles of tetracarboxylic acid residues contained in the above resin by the number of moles of diamine residues contained in the same resin (hereinafter referred to as the "division value Ka"), A value of 0.900 to 1.100 is preferred. If the above division value Ka is within the above range, the molecular weight of the polyimide increases, making it easier to form a film with excellent mechanical properties. Furthermore, from the viewpoint of transparency, a division value Ka of 1.000 to 1.050 is more preferable.

[0076] Furthermore, the closer the division value Ka is to 1, the closer the number of moles of diamine residues and tetracarboxylic acid residues become to equimolar, and therefore the number of repeating units represented by chemical formula (1) tends to increase. Also, if the division value Ka is less than 1, the end of the polymer structure having the repeating unit represented by chemical formula (1) tends to be diamine, and if it is greater than 1, the end of the polymer structure having the repeating unit represented by chemical formula (1) tends to be tetracarboxylic acid.

[0077] The resin film according to the embodiment of the present invention may have its ends sealed with an end-sealing agent. Sealing the ends of the resin with an end-sealing agent tends to result in a resin film with high transparency.

[0078] If the monomer at the end of the resin is a diamine compound, dicarboxylic acid anhydride, monocarboxylic acid, monocarboxylic acid chloride compound, monocarboxylic acid active ester compound, dialkyl dicarbonate, etc., can be used as an end-capturing agent to encapsulate the amino group.

[0079] If the monomer at the end of the resin is an acidic dianhydride, monoamines, monoalcohols, etc., can be used as end-sealing agents to encapsulate the acidic anhydride group.

[0080] The resin film according to the embodiment of the present invention has a wavenumber of 1850 cm in IR measurement. -1 Peak height (H1) and wavenumber including 1775 cm -1 It is preferable that the ratio of peak heights (H2) including (H1 / H2) is 0.08 or less. At wavenumber 1775 cm⁻¹ in IR measurement, this is preferable. -1 This is the wavenumber corresponding to the imide group, which is 1850 cm⁻¹. -1 H1 / H2 is the wavenumber corresponding to the acid anhydride. H1 / H2 can be considered an indicator of the amount of acid anhydride relative to the imide group in the resin film. A value of (H1 / H2) of 0.08 or less is preferable because it reduces the number of end structures that tend to cause discoloration of the resin film, and thus tends to increase the transparency of the resin film.

[0081] In this invention, IR measurement is performed using a Fourier transform infrared spectrophotometer. Depending on the sample morphology and measurement location, the measurement mode can be selected from methods such as transmission or ATR (total reflection), but is not particularly limited. H1 and H2 are the peak heights when the line connecting the tails of each peak is used as the baseline.

[0082] The resin film according to the embodiments of the present invention is not particularly limited, but it is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more, in terms of light transmittance at a wavelength of 400 nm. When the above light transmittance satisfies these ranges, the resin film has superior transparency and can be suitably used in applications requiring transparency.

[0083] The 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 the mechanical properties of the resin film. Furthermore, the 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. If the thickness of the resin film is between 4 μm and 40 μm, the mechanical properties of the resin film will be good. In addition, for applications where higher transparency is required, the thickness is also preferably between 0.5 μm and 4 μm, and even more preferably between 1 μm and 3 μm.

[0084] In the embodiments of the present invention, the resin film preferably has a CTE of 30 ppm or less. A CTE of 30 ppm or less suppresses warping of the support on which the resin film is fabricated. Since large warping makes it difficult to transport the support during device manufacturing, a lower CTE of the resin film is preferable. For example, a CTE of 25 ppm or less is more preferable, 20 ppm or less is even more preferable, and 15 ppm or less is particularly preferable.

[0085] In this invention, CTE is measured using a thermomechanical analyzer. In this process, the sample is heated to 150°C in the first stage at a heating rate of 5°C / min, the sample is air-cooled to room temperature in the second stage at a cooling rate of 5°C / min, and the CTE is obtained by heating the sample in the third stage at a heating rate of 5°C / min.

[0086] In the embodiments of the present invention, the resin film preferably has a Tg of 400°C or higher. A Tg of 400°C or higher suppresses the formation of wrinkles in the film formed on the resin film during high-temperature processes in the manufacture of electronic devices. A higher Tg of the resin film is preferable because it allows for higher process temperatures in the manufacture of electronic devices. For example, a Tg of 415°C or higher is more preferable, and 430°C or higher is even more preferable.

[0087] <Resin composition> The resin composition according to an embodiment of the present invention is a resin composition comprising a resin having repeating units represented by chemical formula (2) and a solvent, wherein the resin film obtained by applying the resin composition and firing it at 430°C for 30 minutes has a YI of 18 or less. In the manufacture of electronic devices, a heat treatment of 430°C or higher is usually used as a condition for producing a resin film with heat resistance that can withstand high-temperature processes. Therefore, a resin composition such that the YI of the resin film obtained by firing it at 430°C for 30 minutes is 18 or less is preferable for providing a resin film that has high transparency, high heat resistance, and low CTE.

[0088] [ka]

[0089] In chemical formula (2), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms, and B represents a divalent diamine residue having 2 or more carbon atoms. However, in 80 mol% or more of the repeating unit represented by chemical formula (2) contained in the resin, B consists of an alicyclic or aromatic diamine residue, and in 30 mol% or more, B is a diamine residue with the structure represented by chemical formula (3), (4), or (5). 1 and R 2 Each of these 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.

[0090] [ka]

[0091] In chemical formulas (3) and (4), two of the α groups are amino groups. The remaining α, along with β, γ, and δ, are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms, except when β is all hydrogen atoms or when γ is all hydrogen atoms. n is either 1 or 2.

[0092] In chemical formula (5), Y is a direct bond, an ether group, an ester group, an amide group, a sulfonyl group, or a hydrocarbon group having 1 to 20 carbon atoms. Z is independently a structure represented by chemical formula (6) or (7).

[0093] [ka]

[0094] In chemical formulas (6) and (7), one of the α groups is an amino group. One of the remaining α and ε groups is bonded to Y. The remaining α, the remaining ε, and β groups are, independently, a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms. n is 1 or 2, except when all β groups are hydrogen atoms.

[0095] In the resin composition according to the embodiment of the present invention, the dihedral angle between the imide group and the diamine moiety of the resulting resin film is increased for the same reasons as described above, and as mentioned above, a resin film with high light transmittance and excellent transparency is obtained.

[0096] Furthermore, the resin composition according to the embodiment of the present invention has a YI value of 18 or less for the resin film obtained by firing at 430°C for 30 minutes, making it suitable for applications requiring transparency. A smaller YI value for the resin film is preferable because it results in better transparency. For example, a YI value of 15 or less is more preferable, and 12 or less is even more preferable.

[0097] A resin having repeating units represented by chemical formula (2) is a resin that can be converted to a resin having repeating units represented by chemical formula (1) by heat treatment, chemical treatment, etc. Hereinafter, a resin having repeating units represented by chemical formula (2) in this manner will be referred to as a "precursor resin." A resin composition containing a precursor resin will be referred to as a "precursor resin composition." Examples of precursor resins include polyimide precursor resins, polyetherimide precursor resins, and polyamideimide precursor resins.

[0098] Specific and preferred examples of A in chemical formula (2) include the structures described above as specific and preferred examples of A in chemical formula (1). Specific and preferred examples of B in chemical formula (2) include the structures described above as specific examples of B in chemical formula (1).

[0099] Furthermore, 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 the "division value Kc") is not particularly limited, but is preferably between 0.900 and 1.100. If the above division value Kc is within the above range, the molecular weight of the polyimide will be high, making it easier to obtain a film with excellent mechanical properties. Moreover, from the viewpoint of the transparency of the resulting resin film, it is more preferable that the above division value Ka is between 1.000 and 1.050.

[0100] Furthermore, the ends of the precursor resin may be sealed with an end-sealing agent. If the monomer at the end of the resin is a diamine compound, dicarboxylic acid anhydride, monocarboxylic acid, monocarboxylic acid chloride compound, monocarboxylic acid active ester compound, dialkyl dicarbonate, etc., can be used as an end-sealing agent to seal its amino group. If the monomer at the end of the resin is an acidic dianhydride, monoamine, monoalcohol, etc., can be used as an end-sealing agent to seal its acidic anhydride group.

[0101] The solvent included in the precursor resin composition can be used without particular limitations as long as it dissolves the precursor resin. Examples of such solvents include aprotic polar solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N,N-dimethylisobutylamide, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, and dimethyl sulfoxide, as well as tetrahydrofuran, dioxane, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, and diethyl Examples of solvents include ethers such as ethylene 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, and 3-methoxybutyl acetate; aromatic hydrocarbons such as toluene and xylene; and solvents described in International Publication No. 2017 / 099183. Any of these solvents may be used individually, or two or more may be used in combination.

[0102] The precursor resin composition may contain an imidation accelerator (i). In this case, it is preferable to contain 0.1 parts by mass or more and less than 100 parts by mass of the imidation accelerator (i) per 100 parts by mass of the precursor resin. When a resin film is produced by firing a coating film of the precursor resin composition, depolymerization may occur simultaneously with the imidation reaction during firing. At this time, if the imidation accelerator (i) is included in the above range, the imidation reaction can be promoted and depolymerization can be suppressed, making it easier to obtain a resin film with a high molecular weight and few end structures. This is preferable because it reduces the end structures that can cause discoloration of the resin film, and the transparency of the resin film tends to be higher.

[0103] As the imidation accelerator (i), for example, heterocyclic compounds containing nitrogen atoms (hereinafter appropriately referred to as "nitrogen-containing heterocyclic compounds"), amine compounds, carboxylic acid compounds, polyhydric phenol compounds, etc., can be used. These compounds may be used individually or in combination of two or more. Among these, nitrogen-containing heterocyclic compounds are preferred because they do not easily remain in the resin film and make it easy to obtain a resin film with high heat resistance.

[0104] Examples of nitrogen-containing heterocyclic compounds include imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 1,2-dimethylimidazole, 3-cyanoimidazole, benzimidazole, pyridine, 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 4-pyridinemethanol, N,N-dimethylaminopyridine, nicotinaldehyde, isonicotinaldehyde, picolinealdehyde, picolinealdehyde oxime, nicotinaldehyde oxime, isonicotinaldehyde oxime, ethyl picolinate, ethyl nicotinate, ethyl isonicotinate, nicotinamide, isonicotinamide, 2-hydroxynicotinic acid, 2,2'-dipyridyl, 4,4'-dipyridyl, 3-methylpyridazine, quinoline, isoquinoline, phenanthroline, 1,10-phenanthroline, and 1,2,4-triazole.

[0105] Examples of amine compounds include trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, and N-ethylpiperidine.

[0106] Examples of polyhydric phenolic compounds include 3,5-dihydroxyacetophenone, methyl 3,5-dihydroxybenzoate, pyrogallol, methyl gallate, ethyl gallate, and naphthalene-1,6-diol.

[0107] Examples of the carboxylic acid compound include 4-hydroxyphenylacetic acid, 3-hydroxybenzoic acid, N-acetylglycine, N-benzoylglycine, and the like.

[0108] 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).

[0109]

Chemical formula

[0110] In Chemical Formula (40), R 5 and R 6 each independently represent a hydrocarbon group having 1 to 20 carbon atoms. m represents an integer of 1 to 4.

[0111] When the precursor resin composition contains the silane compound (h), during the firing of the precursor resin composition, the silane compound (h) condenses to form a siloxane bond. Therefore, since a siloxane site is formed in the resin film obtained by firing, the light transmittance of the resin film can be further improved.

[0112] Examples of the compound having a structure represented by Chemical Formula (40) include, for example, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 1-naphthyltrimethoxysilane, 2-naphthyltrimethoxysilane, 1-naphthyltriethoxysilane, 2-naphthyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like.

[0113] The content of silane compound (h) is preferably 5 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the precursor resin composition. If the content of silane compound (h) is 5 parts by mass or more, the light transmittance of the resin film tends to improve further. If it is 100 parts by mass or less, a resin film with good mechanical properties is more likely to be obtained.

[0114] Furthermore, the precursor resin composition may optionally contain at least one additive selected from a photoacid generator (a), a thermal crosslinking agent (b), a thermal acid generator (c), a compound containing a phenolic hydroxyl group (d), an adhesion improver (e), a surfactant (f), and inorganic particles (g). Specific examples of these additives include, for example, those described in International Publication No. 2017 / 099183.

[0115] 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, per 100 parts by mass of the precursor resin composition. It is also preferably 50 parts by mass or less, and more preferably 40 parts by mass or less.

[0116] The viscosity of the precursor resin composition is preferably 20 to 20,000 mPa·s, and more preferably 50 to 10,000 mPa·s.

[0117] (Method for producing precursor resin composition) Next, a method for producing a precursor resin composition will be described. In the method for producing a precursor resin composition, a precursor resin, and optionally an imidization accelerator (i), a silane compound (h), a photoacid generator (a), a thermal crosslinking agent (b), a thermal acid generator (c), a compound containing a phenolic hydroxyl group (d), an adhesion improver (e), a surfactant (f), and inorganic particles (g) are dissolved or dispersed in a solvent. This yields a varnish, which is one of the precursor resin compositions.

[0118] Furthermore, the precursor resin having the repeating unit represented by chemical formula (2) can be polymerized by known methods. For example, it can be obtained by polymerization in a reaction solvent using a tetracarboxylic acid, or the corresponding acid dianhydride, active ester, or active amide as the acid component, and a diamine, or the corresponding trimethylsilylated diamine, as the diamine component. Alternatively, the precursor resin may be one in which the carboxyl group forms a salt with an alkali metal ion, an ammonium ion, or an 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.

[0119] As the reaction solvent, for example, the solvents described above as specific examples of solvents contained in the precursor resin composition can be used individually or in a mixture of two or more. The amount of reaction solvent used is preferably adjusted so that the total amount of tetracarboxylic acid and diamine compound is 0.1 to 50 parts by mass of the total reaction solution. The reaction temperature is preferably -20°C to 150°C, and more preferably 0 to 100°C. Furthermore, the reaction time is preferably 0.1 to 24 hours, and more preferably 0.5 to 12 hours.

[0120] In the above-mentioned manufacturing method, the tetracarboxylic acid may also be the corresponding acidic dianhydride, activated ester, activated amide, etc. Furthermore, the diamine compound may be the corresponding trimethylsilylated diamine, etc. In addition, the carboxyl group of the resulting resin may be formed by forming a salt with an alkali metal ion, an ammonium ion, or an imidazolium ion, or it may be esterified with a hydrocarbon group having 1 to 10 carbon atoms or an alkylsilyl group having 1 to 10 carbon atoms.

[0121] The obtained precursor resin solution may be used as 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 that used for the precursor resin composition as the reaction solvent, or by adding the solvent after the reaction is complete.

[0122] Furthermore, the obtained precursor resin may be further subjected to imidization or esterification of some of the repeating units of the amide acid. In this case, the precursor resin solution obtained by polymerization of the precursor resin may be used directly in the next reaction, or the precursor resin may be isolated before being used in the next reaction.

[0123] In the esterification and imidation reactions of the precursor resin, the target precursor resin composition can be obtained without isolating the precursor resin by using the same solvent as that used for the precursor resin composition as the reaction solvent, or by adding the solvent after the reaction is complete.

[0124] (Method of manufacturing resin film) Next, a method for manufacturing a resin film according to an embodiment of the present invention will be described. This method for manufacturing a resin film is an example of a method for manufacturing a resin film according to an embodiment of the present invention from the precursor resin composition described above.

[0125] First, a varnish, which is one of the precursor resin compositions according to an embodiment of the present invention, is applied to a support. Examples of support materials include wafer substrates such as silicon and gallium arsenide, glass substrates such as sapphire glass, soda-lime glass, and alkali-free glass, metal substrates or metal foils such as stainless steel and copper, and ceramic substrates. Among these, alkali-free glass is preferred from the viewpoint of surface smoothness and dimensional stability during heating.

[0126] Varnish application methods include spin coating, slit coating, dip coating, spray coating, and printing, and these may be combined. When the resin film is used as a substrate for a display, it needs to be applied to a large support, so the slit coating method is particularly preferred.

[0127] After application, it is common practice to dry the varnish film. Drying methods include vacuum drying, heat drying, or a combination of both. One example of vacuum drying is to place the support with the varnish film in a vacuum chamber and dry the film by reducing the pressure inside the chamber. Another example of heat drying is to use a hot plate, oven, or infrared radiation to dry the film. When using a hot plate, the support with the varnish film is held either directly on the plate or on a jig such as a proxy pin placed on the plate, and the film is heated and dried. The heating temperature varies depending on the type of solvent used in the varnish and the purpose, but it is preferable to heat at a range of 1 minute to several hours in the range of room temperature to 180°C.

[0128] If the resin composition to be coated contains a photoacid generator (a), a pattern can be formed from the dried coating film by the method described below. For example, in this method, the coating film is exposed by irradiating it with a chemical beam through a mask having the desired pattern. Chemical beams used for exposure include ultraviolet light, visible light, electron beams, and X-rays, but in this invention, it is preferable to use the i-line (365 nm), h-line (405 nm), and g-line (436 nm) of a mercury lamp. If the coating film has positive-type photosensitivity, the exposed areas of the coating film dissolve in the developer. If the coating film has negative-type photosensitivity, the exposed areas of the coating film harden and become insoluble in the developer.

[0129] After exposure, a developer is used to remove the exposed areas in the case of a positive film, and the unexposed areas in the case of a negative film, thereby forming the desired pattern on the coating. As the developer, an aqueous solution of an alkaline compound such as tetramethylammonium is preferred in both the positive and negative film types. In some cases, a polar solvent such as N-methyl-2-pyrrolidone, alcohols, esters, ketones, etc., either alone or in combination, may be added to these alkaline aqueous solutions.

[0130] Subsequently, a heating step is performed to heat-treat the coating film on the support to produce a resin film. In this heating step, the coating film is heated in a range of 370°C to 600°C, preferably 400°C to 500°C, and more preferably 410°C to 480°C, to bake the coating film. This allows a resin film to be produced on the support. If the heating temperature (baking temperature) of the coating film in the heating step is 370°C or higher, imidization proceeds sufficiently, and a resin film with excellent mechanical properties is obtained. If the heating temperature is 400°C or higher, a resin film with excellent heat resistance is obtained. Furthermore, if the heating temperature is 500°C or lower, thermal decomposition of the resin is suppressed, and a resin film with excellent transparency is obtained.

[0131] The resin film obtained through the above coating and heating processes can be peeled off the support and used, or it can be used as is without being peeled off the support.

[0132] Examples of delamination methods include mechanical delamination, immersion in water, immersion in chemical solutions such as hydrochloric acid or hydrofluoric acid, and irradiation of the interface between the resin film and the support with laser light in the ultraviolet to infrared wavelength range. In particular, when delamination is performed after creating a device on the resin film, it is necessary to perform delamination without damaging the device, so delamination using an ultraviolet laser is preferred.

[0133] Furthermore, to facilitate peeling, a release agent may be applied to the support or a sacrificial layer may be formed on the support before applying the resin composition to the support. Examples of release agents include silicone-based, fluorine-based, aromatic polymer-based, and alkoxysilane-based agents. Examples of sacrificial layers include metal films, metal oxide films, and amorphous silicon films.

[0134] The resin film according to the embodiment of the present invention is suitably used in display substrates such as substrates for organic EL displays, color filter substrates, touch panel substrates, electronic paper substrates, and μLED display substrates, and is particularly suitably used in flexible display substrates. It can also be used in flexible printed circuit boards, solar cell substrates, surface protective films and interlayer insulating films of semiconductor devices, insulating layers and spacer layers of organic electroluminescent elements (organic EL elements), planarization films of thin-film transistor substrates, insulating layers of organic transistors, binders for electrodes of lithium-ion secondary batteries, and semiconductor adhesives.

[0135] (display) Next, a display according to an embodiment of the present invention will be described. The display according to an embodiment of the present invention includes a resin film according to an embodiment of the present invention.

[0136] The following describes a method for manufacturing a display according to an embodiment of the present invention.

[0137] One example of a display configuration according to an embodiment of the present invention includes a resin film and a display element formed on the resin film.

[0138] The resin film is a resin film according to an embodiment of the present invention and functions as a substrate for a display. A display element is formed on the resin film.

[0139] This method for manufacturing a display includes a film manufacturing step of manufacturing a resin film on a support using the resin film manufacturing method described above, a step of forming a display element on the resin film, and a peeling step of peeling the resin film from the support.

[0140] First, a resin film according to the embodiment of the present invention is manufactured on a support according to the resin film manufacturing method described above.

[0141] An inorganic film may be provided on the resin film as needed. Providing an inorganic film prevents moisture and oxygen from passing through the resin film from the outside and causing 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 as a single layer or by laminating multiple types. The inorganic film is preferably formed using a vapor deposition method such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). These inorganic films can also be used by laminating multiple layers of the resin film and inorganic film alternately. The resin film laminated with the inorganic film is preferably a resin film according to an embodiment of the present invention. Alternatively, another resin film can be formed on a support, and the inorganic film and the resin film according to an embodiment of the present invention can be alternately laminated on this resin film.

[0142] Next, display elements corresponding to the desired display are formed on the obtained resin film or laminate of the resin film and inorganic film. For example, if the display is an organic EL display, an organic EL element is formed as the desired display element by sequentially forming a TFT, a first electrode, a light-emitting element, a second electrode, and a sealing film, which are display elements. If the display is a liquid crystal display, a liquid crystal display element is formed as the desired display element by forming a liquid crystal cell using a first substrate on which an image driving element (TFT), 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, and then injecting liquid crystal. If the display includes a color filter, a color filter element is formed as the desired display element by forming a black matrix as necessary, and then forming colored pixels such as red, green, and blue. If the display includes a touch panel, a touch panel element is formed as the desired display element by forming a wiring layer and an insulating layer.

[0143] Finally, the resin film is peeled off the support, and the peeled resin film (on which the desired display element is formed) is used to obtain a display containing the resin film of the present invention. Methods for peeling at the interface between the support and the resin film include using a laser, a mechanical peeling method, and an etching method of the support. In the laser method, the support, such as a glass substrate, is irradiated with a laser from the side on which the element is not formed, allowing peeling without damaging the element. Alternatively, a primer layer may be provided between the support and the resin film to facilitate peeling. [Examples]

[0144] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. First, the measurements, evaluations, and tests performed in the following examples and comparative examples will be described. Unless otherwise specified, the number of measurements n is 1.

[0145] (Item 1: Measurement of YI of the resin film) For each example, a laminate of the resin film and a glass substrate was prepared, and the YI of the prepared laminate was measured using a spectroscopic haze meter (HSP-150Vis, manufactured by Murakami Color Technology Laboratory Co., Ltd.) in accordance with JIS K 7373:2006.

[0146] (Item 2: Measurement of light transmittance of resin film) For each example, a laminate of the resin film and a glass substrate was fabricated, and the transmittance at a wavelength of 400 nm was measured for the fabricated laminate using a UV-Vis spectrophotometer (Shimadzu Corporation, MultiSpec1500).

[0147] (Item 3: Measurement of Tg and CTE of resin film) For each example, the resin film (sample) obtained was subjected to Tg and CTE measurements using a thermomechanical analyzer (EXSTAR6000TMA / SS6000, manufactured by SII Nanotechnology Co., Ltd.). In the first stage, the sample was heated to 150°C at a heating rate of 5°C / min to remove adsorbed water. In the second stage, the sample was air-cooled to room temperature at a cooling rate of 5°C / min. In the third stage, the sample was heated at a heating rate of 5°C / min, and the Tg and CTE of the sample were measured. The CTE was determined in the temperature range of 50°C to 150°C during the heating process in the third stage.

[0148] (Item 4: IR measurement of resin film) For the resin films (samples) obtained in each example, IR measurements were performed using a Fourier transform infrared spectrophotometer (JASCO Corporation, FT / IR-4600). The measurements were performed using the ATR method, with diamond as the ATR crystal and an incident angle of 45 degrees. From the obtained IR spectra, the wavenumber 1850 cm⁻¹ was determined. -1 Peak height (H1) and wavenumber including 1775 cm -1 The ratio (H1 / H2) of the peak heights (H2) including the specified peak was calculated.

[0149] (compound) The following compounds are used as appropriate in the examples and comparative examples. The compounds and their abbreviations are as follows. DAN: 1,5'-diaminonaphthalene DDS: 4,4'-diaminodiphenylsulfone PDA: p-phenylenediamine TFMB: 2,2'-di(trifluoromethyl)-4,4'-diaminobiphenyl DMPDA: 2,5-dimethyl-1,4-phenylenediamine DCPDA: 2,5-Dichloro-1,4-Phenylenediamine DADMB: 4,4'-diamino-3,3'-dimethylbiphenyl BPDA: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride CpODA: Compounds with the structure represented by chemical formula (36). BNBDA: A compound with the structure represented by chemical formula (37). BPAF: 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride ODPA: 4,4'-Oxydiphthalic anhydride aBPDA: 2,3,3',4'-biphenyltetracarboxylic acid dianhydride 4HPy: 4-hydroxypyridine NMP: N-methyl-2-pyrrolidone.

[0150] [ka]

[0151] (Synthesis Example 1) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DAN (10.42 g (65.9 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (19.58 g (66.5 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0152] (Synthesis Example 2) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60 °C. After raising the temperature, DAN (9.83 g (62.1 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (12.93 g (43.9 mmol)) and CpODA (7.24 g (18.8 mmol)) were added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (6.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0153] (Synthesis Example 3) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60 °C. After raising the temperature, DAN (9.14 g (57.8 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (5.15 g (17.5 mmol)) and CpODA (15.71 g (40.9 mmol)) were added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (6.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0154] (Synthesis Example 4) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DAN (10.18 g (64.3 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (13.38 g (45.5 mmol)) and BNBDA (6.44 g (19.5 mmol)) were added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (6.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0155] (Synthesis Example 5) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DAN (9.87 g (62.4 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (5.56 g (18.9 mmol)) and BNBDA (14.57 g (44.1 mmol)) were added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (6.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0156] (Synthesis Example 6) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60 °C. After raising the temperature, DAN (6.85 g (43.3 mmol)) and DDS (4.68 g (18.8 mmol)) were added while stirring, and after confirming that they were dissolved, BPDA (18.47 g (62.8 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0157] (Synthesis Example 7) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DAN (9.55 g (60.4 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (13.46 g (45.7 mmol)) and BPAF (6.99 g (15.2 mmol)) were added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0158] (Synthesis Example 8) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DAN (10.06 g (64.6 mmol)) was added while stirring, and after confirming that it had dissolved, ODPA (19.94 g (64.3 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0159] (Synthesis Example 9) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DAN (4.48 g (28.3 mmol)) and TFMB (8.86 g (27.7 mmol)) were added while stirring, and after confirming that they were dissolved, BPDA (16.66 g (56.6 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0160] (Synthesis Example 10) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60 °C. After raising the temperature, DAN (10.42 g (65.9 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (14.68 g (49.9 mmol)) and aBPDA (4.89 g (16.6 mmol)) were added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0161] (Synthesis Example 11) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DAN (10.42 g (65.9 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (19.58 g (66.5 mmol)) was added and the mixture was stirred for 12 hours. After that, the reaction solution was cooled to room temperature, diluted with NMP, and then filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0162] (Synthesis Example 12) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, PDA (7.50 g (69.3 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (14.42 g (49.0 mmol)) and CpODA (8.08 g (21.0 mmol)) were added and the mixture was stirred for 12 hours. After that, the reaction solution was cooled to room temperature, diluted with NMP, and then filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0163] (Synthesis Example 13) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, PDA (7.79 g (72.1 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (14.99 g (51.0 mmol)) and BNBDA (7.21 g (21.8 mmol)) were added and the mixture was stirred for 12 hours. After that, the reaction solution was cooled to room temperature, diluted with NMP, and then filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0164] (Synthesis Example 14) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, PDA (8.00 g (74.0 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (22.00 g (74.8 mmol)) was added and the mixture was stirred for 12 hours. After that, the reaction solution was cooled to room temperature, diluted with NMP, and then filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0165] (Synthesis Example 15) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, PDA (5.59 g (51.7 mmol)) and DDS (4.11 g (16.6 mmol)) were added while stirring, and after confirming that they were dissolved, BPDA (20.29 g (69.0 mmol)) was added and the mixture was stirred for 12 hours. After that, the reaction solution was cooled to room temperature, diluted with NMP, and then filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0166] (Synthesis Example 16) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60 °C. After raising the temperature, DAN (2.29 g (14.5 mmol)) and DDS (10.65 g (42.9 mmol)) were added while stirring, and after confirming that they were dissolved, BPDA (17.06 g (58.0 mmol)) was added and the mixture was stirred for 12 hours. After that, the reaction solution was cooled to room temperature, diluted with NMP, and then filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0167] (Synthesis Example 17) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60 °C. After raising the temperature, DAN (2.29 g (14.5 mmol)) and DDS (10.65 g (42.9 mmol)) were added while stirring, and after confirming that they were dissolved, BPDA (17.06 g (58.0 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0168] (Synthesis Example 18) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DAN (2.28 g (14.4 mmol)) and CHDA (6.57 g (57.5 mmol)) were added while stirring, and after confirming that they were dissolved, BPDA (21.16 g (71.9 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0169] (Synthesis Example 19) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DMPDA (9.43 g (69.2 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (20.57 g (69.9 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0170] (Synthesis Example 20) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DCPDA (8.27 g (46.7 mmol)) and PDA (2.09 g (19.4 mmol)) were added while stirring, and after confirming that they were dissolved, BPDA (19.64 g (66.7 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4 HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0171] (Synthesis Example 21) A thermometer and a stirring rod with stirring blades were set up in a 300 mL four-necked flask. Next, NMP (170 g) was added under a stream of dry nitrogen and the temperature was raised to 60°C. After raising the temperature, DADMB (12.50 g (58.9 mmol)) was added while stirring, and after confirming that it had dissolved, BPDA (17.50 g (59.5 mmol)) was added. After stirring for 12 hours, the reaction solution was cooled to room temperature and 4HPy (3.00 g) was added. After dilution with NMP, the solution was filtered through a filter with a pore size of 0.2 μm to obtain the resin composition (varnish).

[0172] The compositions of each resin composition (varnish) obtained in Synthesis Examples 1 to 21 are shown in Tables 1 and 2.

[0173] [Table 1]

[0174] [Table 2]

[0175] (Example 1) Using a slit coating apparatus (manufactured by Toray Engineering Co., Ltd.), the resin composition (varnish) of Synthesis Example 1 was applied to an alkali-free glass substrate (AN-100, manufactured by Asahi Glass Co., Ltd.) measuring 350 mm in length, 300 mm in width, and 0.5 mm in thickness, in an area 5 mm inward from the edge of the glass substrate. Subsequently, using the same apparatus, heating and vacuum drying was performed at a temperature of 40°C. Finally, using a gas oven (INH-21CD, manufactured by Koyo Thermo Systems Co., Ltd.), a resin film with a thickness of 10 μm was formed on the glass substrate by heating at 430°C for 30 minutes under a nitrogen atmosphere (oxygen concentration of 100 ppm or less). The YI of the resin film on the obtained substrate was measured using the method in item 1 above, and the transmittance of the resin film was measured using the method in item 2 above.

[0176] Next, a laser (wavelength: 308 nm) was irradiated onto the glass substrate from the side where the resin film was not deposited, and delamination was performed at the interface with the resin film. The Tg and CTE of the obtained resin film were measured using the method described in item 3 above. In addition, IR measurements were performed using the method described in item 4 above, at a wavenumber of 1850 cm⁻¹. -1 Peak height (H1) and wavenumber including 1775 cm -1 The ratio (H1 / H2) of the peak heights (H2) including the specified peak was calculated.

[0177] (Examples 2-13 and Comparative Examples 1-8) In Examples 2-13 and Comparative Examples 1-8, the same evaluations as in Example 1 were performed using the resin compositions (varnishes) listed in Synthesis Examples 1-21 in Tables 1 and 2.

[0178] The evaluation results for Examples 1-13 and Comparative Examples 1-8 are shown in Table 3.

[0179] [Table 3]

[0180] (Example 101) A gas barrier film consisting of a SiO2 and Si3N4 lamination was deposited on the resin film on the glass substrate obtained in Example 5 by CVD. Subsequently, a TFT was formed, and an insulating film made of Si3N4 was formed covering the TFT. The maximum heating temperature during TFT formation was 400°C. Next, contact holes were formed in this insulating film, and then wiring connected to the TFT was formed through these contact holes.

[0181] Furthermore, a planarization film was formed to flatten the irregularities caused by the wiring. Next, a first electrode made of ITO was formed on the obtained planarization film by connecting it to the wiring. After that, a resist was applied, pre-baked, exposed through a mask of the desired pattern, and developed. Using this resist pattern as a mask, a pattern was processed by wet etching using ITO etchant. After that, the resist pattern was removed using a resist stripping solution (a mixture of monoethanolamine and diethylene glycol monobutyl ether). The substrate after stripping was washed with water and heated to dehydrate it, obtaining an electrode substrate with a planarization film. Next, an insulating film was formed to cover the periphery of the first electrode.

[0182] Furthermore, a hole transport layer, an organic light-emitting layer, and an electron transport layer were sequentially deposited in a vacuum deposition apparatus via a desired pattern mask. Next, a second electrode made of Al / Mg was formed over the entire surface of the substrate. Then, a sealing film consisting of a laminate of SiO2 and Si3N4 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 deposited, and delamination was performed at the interface with the resin film. The irradiation energy at this time was 200 mJ / cm². 2 That's what I decided.

[0183] As described above, an organic EL display device was obtained formed on a resin film. When a voltage was applied via the drive circuit, it showed good light emission.

[0184] (Comparative Example 101) The evaluation was the same as in Example 101, except that the resin film on the glass substrate obtained in Example 2 was replaced with the resin film on the glass substrate obtained in Comparative Example 6. However, when forming the gas barrier film on the resin film, the glass substrate warped significantly and could not be adsorbed onto the stage in the CVD apparatus, preventing the process from proceeding to the next step.

[0185] (Comparative Example 102) The evaluation was the same as in Example 101, except that the resin film on the glass substrate obtained in Example 2 was replaced with the resin film on the glass substrate obtained in Comparative Example 5. However, when heated at 400°C during TFT formation, wrinkles formed in the gas barrier film, and it was not possible to form a normal TFT.

Claims

1. A resin film comprising a resin having a repeating unit represented by chemical formula (1), the resin film having a yellowness index of 18 or less. 【Chemistry 1】 (In chemical formula (1), A represents a tetravalent tetracarboxylic acid residue having two or more carbon atoms. B represents a diamine residue having two or more carbon atoms. However, in 80 mol % or more of the repeating units represented by chemical formula (1) contained in the resin, B represents an alicyclic diamine residue or an aromatic diamine residue, and in 30 mol % or more of the repeating units, B represents a residue of a diamine having a structure represented by chemical formula (3), (4) or (5). 【Chemistry 2】 In chemical formulas (3) and (4), two of the α's are amino groups. The remaining α's, β's, γ's, and δ's are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms, except for the cases where all of the β's are hydrogen atoms and all of the γ's are hydrogen atoms. n is 1 or 2. In chemical formula (5), Y is a direct bond, an ether group, an ester group, an amide group, a sulfonyl group, or a hydrocarbon group having 1 to 20 carbon atoms. Each Z is independently a structure represented by chemical formula (6) or (7). 【Chemistry 3】 In chemical formulas (6) and (7), one of the α's is an amino group. One of the remaining α's and ε's is bonded to Y. The remaining α's, remaining ε's, and β's are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms. n is 1 or 2, except for the case where all of the β's are hydrogen atoms.

2. The resin film according to claim 1 , wherein the resin film has a CTE of 30 ppm / ° C. or less.

3. 2. The resin film according to claim 1, wherein in 30 mol % or more of the repeating units represented by chemical formula (1) contained in the resin, B is a residue of a diamine having a structure represented by chemical formula (4) or chemical formula (5), in which Z in chemical formula (5) is a structure represented by chemical formula (7), and in chemical formulas (4) and (7), n is 1.

4. 2. The resin film according to claim 1, wherein B is a residue of a diamine having a structure represented by chemical formula (8) in 30 mol % or more of the repeating units represented by chemical formula (1) contained in the resin. 【Chemistry 4】 (In chemical formula (8), α and δ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms.)

5. 2. The resin film according to claim 1, wherein A is an alicyclic tetracarboxylic acid residue or an aromatic tetracarboxylic acid residue in 80 mol % or more of the repeating units represented by chemical formula (1) contained in the resin.

6. Wave number in IR measurement: 1850 cm －１ The height of the peak (H1) and the wave number 1775 cm －１ The resin film according to claim 1, wherein the ratio (H1 / H2) of the heights (H2) of the peaks including

7. The resin film according to claim 1 , which is used as a display substrate.

8. A display comprising the resin film according to any one of claims 1 to 7.

9. A resin composition comprising a resin having a repeating unit represented by chemical formula (2) and a solvent, The resin composition is applied to a substrate and baked at 430° C. for 30 minutes to produce a resin film having a yellowness index of 18 or less. 【Chemistry 5】 (In chemical formula (2), A represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms, and B represents a divalent diamine residue having 2 or more carbon atoms. However, in the repeating units represented by chemical formula (2) contained in the resin, 80 mol % or more of B are alicyclic or aromatic diamine residues, and 30 mol % or more of B are residues of diamines having a structure represented by chemical formula (3), (4) or (5). 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. 【Chemistry 6】 In chemical formulas (3) and (4), two of the α's are amino groups. The remaining α's, β's, γ's, and δ's are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon group having 1 to 10 carbon atoms, except for the cases where all of the β's are hydrogen atoms and all of the γ's are hydrogen atoms. n is 1 or 2. In chemical formula (5), Y is a direct bond, an ether group, an ester group, an amide group, a sulfonyl group, or a hydrocarbon group having 1 to 20 carbon atoms. Each Z is independently a structure represented by chemical formula (6) or (7). 【Chemistry 7】 In chemical formulas (6) and (7), one of the α's is an amino group. One of the remaining α's and ε's is bonded to Y. The remaining α's, remaining ε's, and β's are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, or a hydrocarbon having 1 to 10 carbon atoms. n is 1 or 2, except for the case where all of the β's are hydrogen atoms.

10. The resin composition according to claim 9 , further comprising an imidization accelerator in an amount of 0.1 parts by mass or more and less than 100 parts by mass per 100 parts by mass of the resin.

11. The resin composition according to claim 10, wherein the imidization accelerator is a heterocyclic compound containing a nitrogen atom.

12. A method for producing a resin film, comprising the steps of applying the resin composition according to any one of claims 9 to 11 to a support and baking the composition at 400°C to 500°C.

13. A method for manufacturing a display, comprising the steps of: forming a resin film on a support by the method for manufacturing a resin film according to claim 12; forming a display element on the resin film; and peeling the resin film from the support.

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