WO2017057247A1

WO2017057247A1 - Polyimide film, flexible printed board, substrate for led lighting and front plate for flexible display

Info

Publication number: WO2017057247A1
Application number: PCT/JP2016/078221
Authority: WO
Inventors: 康敏伊藤; 崇南條
Original assignee: コニカミノルタ株式会社
Priority date: 2015-10-01
Filing date: 2016-09-26
Publication date: 2017-04-06
Also published as: JPWO2017057247A1

Abstract

The objective of the present invention is to provide a polyimide film which is suppressed in dimensional change due to temperature/humidity changes in the environment. This polyimide film contains a polyimide having a diphenyl ether structure derived from 4, 4'-oxydiphthalic acid anhydride; and this polyimide film is characterized by containing a hydrogen bonding compound that has an aromatic ring and a hydrogen bonding donor site in each molecule.

Description

Polyimide film, flexible printed circuit board, LED lighting substrate, and front panel for flexible display

The present invention relates to a polyimide film, a flexible printed circuit board, a substrate for LED illumination, and a front panel for flexible display. In particular, the present invention relates to a polyimide film in which dimensional variation due to temperature and humidity environment variation is suppressed, a flexible printed circuit board including the polyimide film, an LED illumination substrate, and a flexible display front plate.

Conventionally, polyimide is excellent in heat resistance, but has a brown or yellow color due to high aromatic ring density, and has low transmittance in the visible light region, so it has been difficult to use it in fields where transparency is required. It was.

On the other hand, as a technology to make the polyimide film transparent, by introducing an ether bond having a function of cutting the π-conjugated system into the main chain structure of the polyimide, coloring caused by delocalization of the π-electron system is suppressed. A technique is known (for example, refer to Patent Document 1).

Highly transparent polyimide film is used for substrates and front plates of multilayer (composite) electronic devices such as flexible printed circuit boards (FPCs) and organic electroluminescent elements (also referred to as organic EL elements). Expected to be. However, in the polyimide film described in Patent Document 1, warpage occurs when an electronic device using the polyimide film is used outdoors or used as an in-vehicle application with a large temperature and humidity fluctuation. There was a problem that.

Japanese Patent Laying-Open No. 2015-21022

The present invention has been made in view of the above-described problems and situations, and a solution to the problem is a polyimide film in which dimensional fluctuation due to temperature and humidity environment fluctuation is suppressed, a flexible printed board including the polyimide film, a substrate for LED illumination, and It is to provide a front panel for a flexible display.

As a result of investigating the cause of the above-mentioned problems in order to solve the above-mentioned problems according to the present invention, a polyimide film containing a polyimide having a diphenyl ether structure derived from 4,4′-oxydiphthalic anhydride has an aromatic ring in the molecule and It has been found that by containing a hydrogen bonding compound having a hydrogen bond donor site, dimensional variation due to temperature and humidity environment variations can be suppressed, leading to the present invention.
That is, the subject concerning this invention is solved by the following means.

In a polyimide film containing a polyimide having a diphenyl ether structure derived from 1.4,4'-oxydiphthalic anhydride,
A polyimide film comprising a hydrogen bonding compound having an aromatic ring and a hydrogen bond donor site in the molecule.

2. 2. The polyimide film according to item 1, wherein the value obtained by dividing the number of aromatic rings by the number of hydrogen bond donor sites is in the range of 1 to 5.

3. A flexible printed circuit board comprising the polyimide film according to item 1 or 2.

4. An LED illumination substrate comprising the polyimide film according to item 1 or 2.

5. A front plate for a flexible display, comprising the polyimide film according to item 1 or 2.

ADVANTAGE OF THE INVENTION According to this invention, the polyimide film by which the dimensional fluctuation | variation by temperature / humidity environmental fluctuation | variation was suppressed, a flexible printed circuit board provided with the said polyimide film, a board | substrate for LED lighting, and a front plate for flexible displays can be provided.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
That is, in the above-described conventional polyimide film, it is assumed that the ether bond in the polyimide main chain structure has a low internal rotation barrier and easily undergoes a conformational change, and thus is easily affected by temperature and humidity fluctuations.
Therefore, since the ether bond in the polyimide main chain structure is a hydrogen bond acceptor site, by adding a hydrogen bond compound having an aromatic ring and a hydrogen bond donor site in the molecule to the film, A hydrogen bond is formed with the hydrogen bond donor site of the compound, and an aromatic ring of the hydrogen bond compound is present in the vicinity of the ether bond. Thus, it is considered that the internal rotation barrier of the ether bond is increased and the change in conformation is prevented, whereby the rigid structural unit is obtained, and the dimensional variation of the polyimide film due to the temperature and humidity environment variation is suppressed. In addition, it is presumed that the aromatic ring of the hydrogen bonding compound acts as a steric hindrance, and rotation suppression is likely to occur.

The polyimide film of the present invention is a polyimide film containing a polyimide having a diphenyl ether structure derived from 4,4′-oxydiphthalic anhydride, and contains a hydrogen bonding compound having an aromatic ring and a hydrogen bond donor site in the molecule. It is characterized by that. This feature is a technical feature common to or corresponding to each of claims 1 to 5.
In the present invention, from the viewpoint of manifesting the effects of the present invention, the value obtained by dividing the number of aromatic rings by the number of hydrogen bond donor sites is preferably in the range of 1 to 5.
Moreover, the flexible printed circuit board of this invention, the board | substrate for LED illumination, and the front plate for flexible displays are equipped with the said polyimide film. Thereby, generation | occurrence | production of the curvature of an electronic device can be suppressed in the use for outdoor use or vehicle-mounted use.

Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In the present application, “˜” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

<< Outline of Polyimide Film of the Present Invention >>
The polyimide film of the present invention contains a polyimide having a diphenyl ether structure derived from 4,4′-oxydiphthalic anhydride, and further contains a hydrogen bonding compound having an aromatic ring and a hydrogen bond donor site in the molecule. It is characterized by.

The content of the hydrogen bonding compound is preferably 30% by mass or less, more preferably 1 to 30% by mass, further preferably 2 to 20% by mass, and 3 to 15% by mass. It is particularly preferred. If the content of the hydrogen bonding compound is less than 1% by mass, the effect of suppressing the occurrence of dimensional variation due to temperature and humidity environment fluctuations of the present invention is insufficient, and if it exceeds 30% by mass, the compatibility with polyimide decreases. , The effect of reducing transparency and suppressing dimensional variation is insufficient.

Moreover, as a detection method of content of the hydrogen bonding compound contained in a polyimide film, methods, such as a swelling reprecipitation method and an ultrasonic extraction method, are mentioned, for example.
In the swelling reprecipitation method, first, the polyimide film is swollen with a swelling solvent such as dimethylacetamide, γ-butyrolactone, or N-methyl-2-pyrrolidone. Next, the swollen polyimide film is immersed in a polar solvent such as alcohols such as methanol, acetone or acetonitrile, and the supernatant is recovered. The content of the hydrogen bonding compound can be determined by using a known quantitative analysis method such as HPLC or GC / MS measurement on the collected supernatant.
In the ultrasonic extraction method, ultrasonic treatment is performed in a state where the polyimide film is immersed in an alcohol such as methanol, or a polar solvent such as acetone or acetonitrile, and the supernatant is recovered. As the ultrasonic treatment, an ultrasonic wave is applied at an output of 100 W for about 30 minutes using an ultrasonic cleaner CPX series manufactured by Yamato Scientific. The content of the hydrogen bonding compound can be determined by using a known quantitative analysis method such as HPLC or GC / MS measurement on the collected supernatant.

[1] Polyimide Any polyimide may be used in the present invention as long as it has a diphenyl ether structure derived from 4,4′-oxydiphthalic anhydride. For example, the following polyimides 1 to 4 can be used. In addition, the polyimide film of this invention may contain the component which is not imidized, ie, a polyamic acid.

[1.1] Polyimide 1
The polyimide film of the present invention contains a polyimide or polyamic acid formed from diamine or a derivative thereof and 4,4′-oxydiphthalic anhydride.

As the polyimide or polyamic acid that can be used in the present invention, in particular, a polyimide having a repeating unit represented by the following general formula (1.1) (hereinafter referred to as polyimide (A)) or the following general formula (1) And polyamic acid having a repeating unit represented by (2) (hereinafter referred to as polyamic acid (A ′)) is preferred.

In the general formulas (1.1) and (1.2), R represents a residue of 4,4′-oxydiphthalic anhydride. Φ is a group composed of a divalent aliphatic hydrocarbon group having 2 to 39 carbon atoms, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof, and —O—, At least selected from the group consisting of —SO ₂ —, —CO—, —CH ₂ —, —C (CH ₃ ) ₂ —, —OSi (CH ₃ ) ₂ —, —C ₂ H ₄ O— and —S—. You may have one group.

In the general formulas (1.1) and (1.2), examples of the divalent aliphatic hydrocarbon group having 2 to 39 carbon atoms having or not having the above-described bonding group represented by Φ include, for example, the following structures: Examples include groups represented by the formula.

In the above structural formula, n represents the number of repeating units, preferably 1 to 5, and more preferably 1 to 3. X is an alkanediyl group having 1 to 3 carbon atoms, that is, a methylene group, an ethylene group, a trimethylene group, or a propane-1,2-diyl group, and a methylene group is preferable.

Examples of the divalent alicyclic hydrocarbon group having 2 to 39 carbon atoms with or without the above-described bonding group represented by Φ include groups represented by the following structural formula.

Examples of the divalent aromatic hydrocarbon group having 2 to 39 carbon atoms with or without the above-described bonding group represented by Φ include groups represented by the following structural formulas.

Examples of the group composed of a combination of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group represented by Φ include groups represented by the following structural formula.

The group represented by Φ is preferably a divalent aromatic hydrocarbon group having 2 to 39 carbon atoms having a linking group, or a combination of the aromatic hydrocarbon group and an aliphatic hydrocarbon group. A group represented by the following structural formula is preferred.

As described above, the polyamic acid (A ′) corresponds to a structure in which a part of the imide bond of the polyimide (A) is dissociated, and the detailed description of the polyamic acid (A ′) can be considered corresponding to the polyimide (A). Therefore, the polyimide (A) will be typically described in detail below.

The repeating unit represented by the general formula (1.1) is preferably 10 to 100 mol%, more preferably 50 to 100 mol%, still more preferably 80 to 100 mol%, particularly with respect to all repeating units. 90 to 100 mol% is preferred. The number of repeating units of the general formula (1.1) in one molecule of polyimide (A) is 10 to 2000, preferably 20 to 200. In this range, the glass transition temperature is 230 to 350 ° C. It is preferable that the temperature is 250 to 330 ° C.

Polyimide (A) is obtained by reacting 4,4′-oxydiphthalic anhydride with diamine or a derivative thereof to prepare polyamic acid (A ′) and imidizing the polyamic acid (A ′). It is done.

When the polyimide (A) has a fluorene skeleton, the fluorene skeleton is preferably contained in an amount of 50 mol% or less, more preferably 20 to 50 mol% in order to exhibit the effect of reducing the coloration of the film. More preferably, it is contained in an amount of ˜50 mol%.

The polyimide according to the present invention has a diphenyl ether structure derived from 4,4′-oxydiphthalic anhydride, and is prepared by using other acid anhydrides in addition to 4,4′-oxydiphthalic anhydride. It may be a thing. In that case, the other acid anhydride may have a fluorene skeleton.

Among other acid anhydrides used in the present invention, examples of acid anhydrides having no fluorene skeleton include carboxylic acid anhydrides, and may be aromatic, aliphatic or alicyclic tetracarboxylic acids or derivatives thereof. Preferable examples include aliphatic or alicyclic tetracarboxylic acid esters, aliphatic or alicyclic tetracarboxylic dianhydrides, and the like. Of aromatic, aliphatic or alicyclic tetracarboxylic acids or derivatives thereof, alicyclic tetracarboxylic dianhydrides are preferred.

Here, the derivative of an aliphatic or alicyclic tetracarboxylic acid is a compound that can be changed to an aliphatic or alicyclic tetracarboxylic acid. For example, in the case of an aliphatic tetracarboxylic dianhydride, the anhydride Instead, a compound having two carboxy groups, a compound in which one or both of these two carboxy groups are esterified, or one or both of these two carboxy groups are chlorinated Acid chloride or the like is preferably used.

By using such an acyl compound, it is possible to obtain a film having high heat resistance and excellent optical properties and less coloring (yellowing).

Examples of the aliphatic tetracarboxylic acid include 1,2,3,4-butanetetracarboxylic acid.
Examples of the alicyclic tetracarboxylic acid include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,4,5-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid. Bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid, etc. Can be mentioned.

Examples of the aliphatic tetracarboxylic acid esters include monoalkyl esters, dialkyl esters, trialkyl esters, and tetraalkyl esters of the above aliphatic tetracarboxylic acids.
Examples of the alicyclic tetracarboxylic acid esters include monoalkyl esters, dialkyl esters, trialkyl esters, and tetraalkyl esters of the above alicyclic tetracarboxylic acids. The alkyl group site is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.

Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride.
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclopentanetetracarboxylic dianhydride, , 4,5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] Examples include octane-2,3,5,6-tetracarboxylic dianhydride and 2,3,5-tricarboxycyclopentylacetic acid dianhydride. Particularly preferred is 1,2,4,5-cyclohexanetetracarboxylic dianhydride. In general, a polyimide having an aliphatic diamine as a constituent component forms a strong salt between the polyamic acid, which is an intermediate product, and the diamine. Therefore, in order to increase the molecular weight, a solvent having a relatively high salt solubility (for example, cresol). N, N-dimethylacetamide, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) are preferably used. However, even with polyimides containing aliphatic diamine as a constituent, when 1,2,4,5-cyclohexanetetracarboxylic dianhydride is used as a constituent, the salt of polyamic acid and diamine is bound by a relatively weak bond. Therefore, it is easy to obtain a high molecular weight and a flexible film can be easily obtained.

Examples of the aromatic tetracarboxylic acid include 4,4′-biphthalic anhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, and 2,3,3 ′, 4′-biphenyltetracarboxylic acid. Dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1 , 2-dicarboxylic anhydride, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,4'-oxydiphthalic anhydride, 3,4,9,10-perylenetetracarboxylic acid Anhydride (Pigment Red 224), 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,2-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane Anhydride, 9,9-bis (3,4-carboxyphenyl) fluorene, 9,9-bis [4- (3,4-dicarboxyphenoxy) - phenyl] fluorene anhydride and the like.
In addition, for example, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, Tricyclo [6.4.0.02,7] dodecane-1,8: 2,7-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene- 1,2-dicarboxylic acid anhydride and the like can be used.

Further, other tetracarboxylic acids or derivatives thereof (particularly dianhydrides) may be further used in combination as long as the solvent solubility of the polyimide, the flexibility of the film, the thermocompression bonding property, and the transparency are not impaired.

Examples of such other tetracarboxylic acids or derivatives thereof include pyromellitic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2, 2-bis (3,4-dicarboxyphenyl) propane, 2,2-bis (2,3-dicarboxyphenyl) propane, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1 , 3,3,3-hexafluoropropane, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, bis (3,4-dicarboxy) Phenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, bis (2,3-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 2,2 ′ 3,3′-benzophenonetetracarboxylic acid, 4,4- (p-phenylenedioxy) diphthalic acid, 4,4- (m-phenylenedioxy) diphthalic acid, 1,1-bis (2,3-dicarboxyl) Aromatic tetracarboxylic acids such as phenyl) ethane, bis (2,3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) methane and their derivatives (especially dianhydrides); ethylenetetracarboxylic acid Examples thereof include aliphatic tetracarboxylic acids having 1 to 3 carbon atoms and derivatives thereof (particularly dianhydrides).

Among the other acid anhydrides used in the present invention, examples of the acid anhydride having a fluorene skeleton include 9,9-bis (3,4-dicarboxyphenyl) fluorenic acid dianhydride and 9,9-bis. [4- (3,4-dicarboxyphenoxy) phenyl] fluorenic dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -3-phenylphenyl] fluorenic dianhydride, 9 , 9-bis [4- (2,3-dicarboxyphenoxy) -3-phenylphenyl] fluoric acid dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -2-phenylphenyl Fluoronic acid dianhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -2-phenylphenyl] fluoric acid dianhydride, 9,9-bis [4- (3,4-dicarbo. Ciphenoxy) -3-methylphenyl] fluorenic dianhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -3-methylphenyl] fluorenic dianhydride, 9,9-bis [ 4- (3,4-Dicarboxyphenoxy) -2-methylphenyl] fluorenic dianhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -2-methylphenyl] fluorenic dianhydride 9,9-bis [4- (3,4-dicarboxyphenoxy) -3-ethylphenyl] fluorenic dianhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -3 -Ethylphenyl] fluorenic dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -2-ethylphenyl] fluorenic dianhydride, 9,9-bis [4- (2, 3-di Ruboxyphenoxy) -2-ethylphenyl] fluoric acid dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -3-propylphenyl] fluoric acid dianhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -3-propylphenyl] fluoric dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -2-propylphenyl] fluorenic acid Anhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -2-propylphenyl] fluorenic dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy)- 3-butylphenyl] fluorenic dianhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -3-butylphenyl] fluorenic dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -2-butylphenyl] fluorenic dianhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -2-butylphenyl] fluorenic dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -3-tert-butylphenyl] fluorenic dianhydride, 9,9-bis [4- (2,3-dicarboxyphenoxy) -3 -T-butylphenyl] fluoric acid dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -2-t-butylphenyl] fluoric acid dianhydride, 9,9-bis [4 -(2,3-dicarboxyphenoxy) -2-t-butylphenyl] fluorenic dianhydride, and the like. Of these aromatic bis (ether anhydride) compounds, 9,9-bis [4- (3,4-dicarboxyphenoxy) phenyl] fluorenic dianhydride, 9,9-bis [4- (3 , 4-dicarboxyphenoxy) -3-phenylphenyl] fluorenic dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -2-phenylphenyl] fluorenic dianhydride, 9-bis [4- (3,4-dicarboxyphenoxy) -3-methylphenyl] fluorenic dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) -2-methylphenyl] And fluoric acid dianhydride.

Among them, 9,9-bis (3,4-dicarboxyphenyl) fluoric acid dianhydride or 9,9-bis [4- (3,4-dicarboxyphenoxy) phenyl] fluoric acid dianhydride should be used. Is preferable from the viewpoints of heat resistance and transparency.

As the diamine or derivative thereof, for example, aromatic diamine or isocyanate is preferable, and aromatic diamine is preferable.

As described above, the polyamic acid or polyimide used in the present invention is formed from diamine or a derivative thereof and 4,4′-oxydiphthalic anhydride, and when the polyamic acid or polyimide has a fluorene skeleton, the diamine is a fluorene skeleton. It is preferable that the other acid anhydride described above has a fluorene skeleton. The diamine having a fluorene skeleton or a derivative thereof is preferably an aromatic diamine having a fluorene skeleton or an isocyanate.

Of the diamines or derivatives thereof used in the present invention, the diamine or derivative thereof having no fluorene skeleton may be an aromatic diamine, an aliphatic diamine, or a mixture thereof, and the whitening of the film is an aromatic diamine. From the viewpoint that can be suppressed.

In the present invention, the term “aromatic diamine” refers to a diamine in which an amino group is directly bonded to an aromatic ring, and an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or any other part of its structure. A substituent (for example, a halogen atom, a sulfonyl group, a carbonyl group, an oxygen atom, etc.) may be contained. The term “aliphatic diamine” refers to a diamine in which an amino group is directly bonded to an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group or other substituent ( For example, a halogen atom, a sulfonyl group, a carbonyl group, an oxygen atom, etc.) may be included.

Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, benzidine, o-tolidine, m-tolidine, bis (trifluoromethyl) benzidine, Octafluorobenzidine, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3, , 3'-difluoro-4,4'-diaminobiphenyl, 2,6-diaminonaphthalene, 1,5-diaminonaphthalene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diamino Diphenylmethane, 4,4'-diaminodiphenylsulfone, 3,4'-dia Nodiphenylsulfone, 4,4'-diaminobenzophenone, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (2-methyl-4-aminophenoxy) phenyl) Propane, 2,2-bis (4- (2,6-dimethyl-4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2- Bis (4- (2-methyl-4-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (2,6-dimethyl-4-aminophenoxy) phenyl) hexafluoropropane, 4,4 ′ -Bis (4-aminophenoxy) biphenyl, 4,4'-bis (2-methyl-4-aminophenoxy) biphenyl, 4,4'-bis (2,6 Dimethyl-4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (2-methyl-4-aminophenoxy) ) Phenyl) sulfone, bis (4- (2,6-dimethyl-4-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) ether, bis (4- (2-methyl-4-) Aminophenoxy) phenyl) ether, bis (4- (2,6-dimethyl-4-aminophenoxy) phenyl) ether, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (2-methyl-) 4-aminophenoxy) benzene, 1,4-bis (2,6-dimethyl-4-aminophenoxy) benzene, 1,3-bis (4-a Minophenoxy) benzene, 1,3-bis (2-methyl-4-aminophenoxy) benzene, 1,3-bis (2,6-dimethyl-4-aminophenoxy) benzene, 2,2-bis (4-amino) Phenyl) propane, 2,2-bis (2-methyl-4-aminophenyl) propane, 2,2-bis (3-methyl-4-aminophenyl) propane, 2,2-bis (3-ethyl-4-) Aminophenyl) propane, 2,2-bis (3,5-dimethyl-4-aminophenyl) propane, 2,2-bis (2,6-dimethyl-4-aminophenyl) propane, 2,2-bis (4 -Aminophenyl) hexafluoropropane, 2,2-bis (2-methyl-4-aminophenyl) hexafluoropropane, 2,2-bis (2,6-dimethyl-4-aminophenyl) he Safluoropropane, α, α'-bis (4-aminophenyl) -1,4-diisopropylbenzene (bisaniline P), α, α'-bis (2-methyl-4-aminophenyl) -1,4-diisopropyl Benzene, α, α'-bis (2,6-dimethyl-4-aminophenyl) -1,4-diisopropylbenzene, α, α'-bis (3-aminophenyl) -1,4-diisopropylbenzene, α, α'-bis (4-aminophenyl) -1,3-diisopropylbenzene (bisaniline M), α, α'-bis (2-methyl-4-aminophenyl) -1,3-diisopropylbenzene, α, α ' -Bis (2,6-dimethyl-4-aminophenyl) -1,3-diisopropylbenzene, α, α'-bis (3-aminophenyl) -1,3-diisopropylbenzene, 1,1-bis (4-aminophenyl) cyclopentane, 1,1-bis (2-methyl-4-aminophenyl) cyclopentane, 1,1-bis (2,6-dimethyl-4-aminophenyl) cyclo Pentane, 1,1-bis (4-aminophenyl) cyclohexane, 1,1-bis (2-methyl-4-aminophenyl) cyclohexane, 1,1-bis (2,6-dimethyl-4-aminophenyl) cyclohexane 1,1-bis (4-aminophenyl) 4-methyl-cyclohexane, 1,1-bis (4-aminophenyl) norbornane, 1,1-bis (2-methyl-4-aminophenyl) norbornane, 1, 1-bis (2,6-dimethyl-4-aminophenyl) norbornane, 1,1-bis (4-aminophenyl) adamantane, 1,1-bis (2-methyl) -4-aminophenyl) adamantane, 1,1-bis (2,6-dimethyl-4-aminophenyl) adamantane, 1,4-phenylenediamine, 3,3'-diaminobenzophenone, 2,2-bis (3- Aminophenyl) hexafluoropropane, 3-aminobenzylamine, 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] sulfone, 1,3-bis [2- (4-aminophenyl) -2-propyl] benzene, bis ( 2-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, 1,3-bis (3-aminopropyl) tetrame Rudisiloxane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-ethylenedianiline, 4,4'-methylenebis (2,6-diethylaniline), 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis (3-amino-4-hydroxyphenyl) hexa Fluoropropane, 5,5 '-(hexafluoroisopropylidene) di-o-toluidine, 2,2'-bis (trifluoromethyl) benzidine, 4,4'-diaminooctafluorobiphenyl, resorcinol bis (3-amino Phenyl) ether, resorcinol bis (4-aminophenyl) ether, bis (3-amino) Enyl) sulfone, bis (4-aminophenyl) sulfone (trade name: SEIKACURE-S, manufactured by Seika Co., Ltd.), 4,4′-thiodianiline, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 2,7-diaminofluorene, 2,5-dimethyl-1,4-phenylenediamine, 4,4'-methylenebis (2-ethyl-6-methylaniline), 2,3,5 , 6-tetramethyl-1,4-phenylenediamine, m-xylylenediamine, p-xylylenediamine, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4'- Diamino-3,3 ', 5,5'-tetraisopropyldiphenylmethane, 3,3-diaminodiphenylsulfone, 1- ( 4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-5-amine, 1,4-bis (2-amino-isopropyl) benzene, 1,3-bis (2- Amino-isopropyl) benzene and the like.

Examples of the aliphatic diamine include ethylene diamine, hexamethylene diamine, polyethylene glycol bis (3-aminopropyl) ether, polypropylene glycol bis (3-aminopropyl) ether, 1,3-bis (aminomethyl) cyclohexane (cis form and a mixture of trans isomers), 1,4-bis (aminomethyl) cyclohexane (a mixture of cis isomers and trans isomers), isophorone diamine, norbornane diamine, siloxane diamine, 4,4'-diaminodicyclohexyl methane, 3,3'- Dimethyl-4,4'-diaminodicyclohexylmethane, 3,3'-diethyl-4,4'-diaminodicyclohexylmethane, 3,3 ', 5,5'-tetramethyl-4,4'-diaminodicyclohexylmethane, 2 , 3 Bis (aminomethyl) -bicyclo [2.2.1] heptane, 2,5-bis (aminomethyl) -bicyclo [2.2.1] heptane, 2,6-bis (aminomethyl) -bicyclo [2. 2.1] Heptane, 2,2-bis (4,4'-diaminocyclohexyl) propane, 2,2-bis (4,4'-diaminomethylcyclohexyl) propane, bis (aminomethyl) norbornane (isomer mixture) , Bicyclo [2.2.1] heptanedimethanamine (isomer mixture), 4,4'-methylenebis (2-methylcyclohexylamine) (isomer mixture), 4,4'-methylenebis (cyclohexylamine) (isomer) Body mixture) and the like.

Examples of isocyanate esters that are diamine derivatives include diisocyanates obtained by reacting the above aromatic or aliphatic diamines with phosgene.

In addition, examples of other diamine derivatives include diaminodisilanes, such as trimethylsilylated aromatic or aliphatic diamines obtained by reacting the above aromatic or aliphatic diamines with chlorotrimethylsilane.

The above diamines and derivatives thereof may be used in any mixture, but the amount of diamine in them is preferably 50 to 100 mol%, more preferably 80 to 100 mol%.

Of the diamines or derivatives thereof used in the present invention, the diamine having a fluorene skeleton or a derivative thereof is preferably an aromatic diamine, such as 9,9-bis [4- (4-aminophenoxy) phenyl]. Fluorene, 9,9-bis [4- (4-aminophenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3-aminophenoxy) -3-phenylphenyl] fluorene, 9,9- Bis [4- (2-aminophenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-3-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [ 4- (4-Amino-2-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-3-ethyl) Enoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-2-ethylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-3) -I-propylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-2-i-propylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-3-t-butylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3-phenylphenyl] fluorene, 9, 9-bis [4- (4-amino-3-trifluoromethylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoro) Methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3-amino-2-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3-amino- 4-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3-amino-5-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3- Amino-6-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3-amino-2-trifluoromethylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4 -(3-Amino-4-trifluoromethylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3-amino-5-trifluoro Methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (3-amino-6-trifluoromethylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2- Amino-3-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2-amino-4-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- ( 2-amino-5-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2-amino-6-methylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4 -(2-Amino-3-trifluoromethylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2-amino-4-trifluoro) Tylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2-amino-5-trifluoromethylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2- Amino-6-trifluoromethylphenoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) phenyl] fluorene, 9,9-bis [4- (4- Amino-2-ethylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-2-n-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-2-) i-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) phenyl] fluorene, 9,9-bis 4- (4-amino-2-trifluoromethylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-3-methylphenoxy) phenyl] fluorene, 9,9-bis [4- (4 -Amino-3-ethylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-3-n-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-3) -I-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-3-t-butylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-3-tri Fluoromethylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-3-methylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino- 4-methylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-5-methylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-6-methylphenoxy) phenyl Fluorene, 9,9-bis [4- (2-amino-3-ethylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-4-ethylphenoxy) phenyl] fluorene, 9,9 -Bis [4- (2-amino-5-ethylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-6-ethylphenoxy) phenyl] fluorene, 9,9-bis [4- ( 2-amino-3-n-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-4-n-propylphenoxy) phenyl] fluorene, 9 9-bis [4- (2-amino-5-n-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-6-n-propylphenoxy) phenyl] fluorene, 9,9- Bis [4- (2-amino-3-i-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-4-i-propylphenoxy) phenyl] fluorene, 9,9-bis [ 4- (2-amino-5-i-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-6-i-propylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-Amino-3-t-butylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-4-t-butylphenoxy) phenyl] fluorene, 9,9-bis [4 (2-Amino-5-t-butylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-6-t-butylphenoxy) phenyl] fluorene, 9,9-bis [4- (2 -Amino-3-trifluoromethylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-4-trifluoromethylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino) -5-trifluoromethylphenoxy) phenyl] fluorene, 9,9-bis [4- (2-amino-6-trifluoromethylphenoxy) phenyl] fluorene, 9,9-bis [4- (4-amino-2 -Methylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (4-amino-2-ethylphenoxy) -3-methylphenyl] fluore 9,9-bis [4- (4-amino-2-n-propylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (4-amino-2-i-propylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (4-amino-2) -Trifluoromethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) -3-ethylphenyl] fluorene, 9,9-bis [4- (4 -Amino-2-ethylphenoxy) -3-ethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-n-propylphenoxy) -3-ethylphenyl] fluorene, 9,9-bis 4- (4-amino-2-i-propylphenoxy) -3-ethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3-ethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) -3-ethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) -3-n -Propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-ethylphenoxy) -3-n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-n) -Propylphenoxy) -3-n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-i-propylphenoxy) -3-n-propylphenyl] fluorene, 9, -Bis [4- (4-amino-2-t-butylphenoxy) -3-n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) -3- n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) -3-i-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2- Ethylphenoxy) -3-i-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-n-propylphenoxy) -3-i-propylphenyl] fluorene, 9,9-bis [4 -(4-Amino-2-i-propylphenoxy) -3-i-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3-i-propylphenol Nyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) -3-i-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methyl) Phenoxy) -3-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-ethylphenoxy) -3-t-butylphenyl] fluorene, 9,9-bis [4- (4 -Amino-2-n-propylphenoxy) -3-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-i-propylphenoxy) -3-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) 3-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) -3-trifluoromethylphenyl] fluorene, 9,9-bis [4- (4-amino- 2-ethylphenoxy) -3-trifluoromethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-n-propylphenoxy) -3-trifluoromethylphenyl] fluorene, 9,9-bis [4- (4-Amino-2-i-propylphenoxy) -3-trifluoromethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3-trifluoro Methylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) -3-trifluoromethylphenyl] fluorene, , 9-bis [4- (4-amino-2-methylphenoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-ethylphenoxy) -3,5- Dimethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-n-propylphenoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis [4- (4-amino-2- i-propylphenoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis [4- (4-Amino-2-trifluoromethylphenoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) -3,5-diethylphen Nyl] fluorene, 9,9-bis [4- (4-amino-2-ethylphenoxy) -3,5-diethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-n-propyl) Phenoxy) -3,5-diethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-i-propylphenoxy) -3,5-diethylphenyl] fluorene, 9,9-bis [4- (4-Amino-2-t-butylphenoxy) -3,5-diethylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) -3,5-diethylphenyl] Fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) -3,5-di-n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-ethylpheno) Iii) -3,5-di-n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-n-propylphenoxy) -3,5-di-n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-i-propylphenoxy) -3,5-di-n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t -Butylphenoxy) -3,5-di-n-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) -3,5-di-n-propylphenyl] Fluorene, 9,9-bis [4- (4-amino-2-methylphenoxy) -3,5-di-i-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-ethyl) Phenoxy) -3,5-di-ip Pyrenyl] fluorene, 9,9-bis [4- (4-amino-2-n-propylphenoxy) -3,5-di-i-propylphenyl] fluorene, 9,9-bis [4- (4-amino -2-i-propylphenoxy) -3,5-di-i-propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3,5-di-i -Propylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) -3,5-di-i-propylphenyl] fluorene, 9,9-bis [4- (4 -Amino-2-methylphenoxy) -3,5-di-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-ethylphenoxy) -3,5-di-t-butyl Phenyl] fluorene, 9, 9-bis [4- (4-amino-2-n-propylphenoxy) -3,5-di-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-i-propyl) Phenoxy) -3,5-di-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3,5-di-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-trifluoromethylphenoxy) -3,5-di-t-butylphenyl] fluorene, 9,9-bis [4- (4-amino-2-methyl) Phenoxy) -3,5-di (trifluoromethyl) phenyl] fluorene, 9,9-bis [4- (4-amino-2-ethylphenoxy) -3,5-di (trifluoromethyl) phenyl] fluorene, 9,9-bis [4- (4 Amino-2-n-propylphenoxy) -3,5-di (trifluoromethyl) phenyl] fluorene, 9,9-bis [4- (4-amino-2-i-propylphenoxy) -3,5-di (Trifluoromethyl) phenyl] fluorene, 9,9-bis [4- (4-amino-2-t-butylphenoxy) -3,5-di (trifluoromethyl) phenyl] fluorene, 9,9-bis [ 4- (4-Amino-2-trifluoromethylphenoxy) -3,5-di (trifluoromethyl) phenyl] fluorene, 9,9-bis [4- (2-amino-3-methylphenoxy) -3- Methylphenyl] fluorene, 9,9-bis [4- (2-amino-4-methylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (2-amino-5-methylphenyl) Noxy) -3-methylphenyl] fluorene, 9,9-bis [4- (2-amino-6-methylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (2-amino-3) -Trifluoromethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (2-amino-4-trifluoromethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (2-amino-5-trifluoromethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (2-amino-6-trifluoromethylphenoxy) -3-methylphenyl] fluorene, 9, 9-bis [4- (3-amino-2-methylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-4-methylpheno) Xyl) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-5-methylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-6) -Methylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-2-ethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino -4-ethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-5-ethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3 -Amino-6-ethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-2-n-propylphenoxy) -3-methylphenyl] fluorene, 9, -Bis [4- (3-amino-4-n-propylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-5-n-propylphenoxy) -3-methylphenyl Fluorene, 9,9-bis [4- (3-amino-6-n-propylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-2-i-propylphenoxy) ) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-4-i-propylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-) 5-i-propylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-6-i-propylphenoxy) -3-methylphenyl] fluorene, 9,9-bis 4- (3-amino-2-t-butylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-4-t-butylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-5-t-butylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-6-t-butylphenoxy) -3 -Methylphenyl] fluorene, 9,9-bis [4- (3-amino-2-trifluoromethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-4-tri Fluoromethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-amino-5-trifluoromethylphenoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (3-Amino-6-trifluoromethylphenoxy) -3-methylphenyl] fluorene and the like.

When the polyamic acid or polyimide used in the present invention has a fluorene skeleton, 9,9-bis (4-aminophenyl) fluorene, 9,9-bis (4-amino3-methylphenyl) fluorene is used as a diamine or a derivative thereof. Alternatively, 9,9-bis (3-fluoro-4-aminophenyl) fluorene is preferable from the viewpoint of improving non-coloring property, whitening and bending resistance.

Polyamic acid can be obtained by polymerizing 4,4′-oxydiphthalic anhydride and at least one of the diamines in a suitable solvent.

The polyamic acid ester is diesterified by ring-opening 4,4'-oxydiphthalic anhydride with an alcohol such as methanol, ethanol, isopropanol, or n-propanol, and the obtained diester is dissolved in a suitable solvent. It can obtain by making it react with the said diamine compound. Furthermore, the polyamic acid ester can also be obtained by esterification by reacting the carboxylic acid group of the polyamic acid obtained as described above with an alcohol as described above.

The reaction between 4,4′-oxydiphthalic anhydride and the diamine compound can be performed under conditions known in the art. There are no particular restrictions on the order or method of addition of 4,4'-oxydiphthalic anhydride and diamine compound. For example, 4,4′-oxydiphthalic anhydride and a diamine compound are sequentially added to a solvent and stirred at an appropriate temperature to obtain a polyamic acid.

The amount of the diamine compound is usually 0.8 mol or more, preferably 1 mol or more, per 1 mol of 4,4′-oxydiphthalic anhydride. On the other hand, it is 1.2 mol or less normally, Preferably it is 1.1 mol or less. The yield of the polyamic acid obtained can be improved by making the quantity of a diamine compound into such a range.

The concentration of 4,4′-oxydiphthalic anhydride and diamine compound in the solvent is appropriately set according to the reaction conditions and the viscosity of the polyamic acid solution. For example, the total mass of 4,4′-oxydiphthalic anhydride and the diamine compound is not particularly limited, but is usually 1% by mass or more, preferably 5% by mass or more, based on the total amount of the solution. The amount is usually 70% by mass or less, preferably 30% by mass or less. By setting the amount of the reaction substrate in such a range, the polyamic acid can be obtained at a low cost and in a high yield.

The reaction temperature is not particularly limited, but is usually 0 ° C. or higher, preferably 20 ° C. or higher, and is usually 100 ° C. or lower, preferably 80 ° C. or lower. The reaction time is not particularly limited but is usually 1 hour or longer, preferably 2 hours or longer, and is usually 100 hours or shorter, preferably 24 hours or shorter. By performing the reaction under such conditions, the polyamic acid can be obtained at a low cost and in a high yield.

Examples of the polymerization solvent used in this reaction include hydrocarbon solvents such as hexane, cyclohexane, heptane, benzene, toluene, xylene and mesitylene; carbon tetrachloride, dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene and dichlorobenzene. And halogenated hydrocarbon solvents such as fluorobenzene; ether solvents such as diethyl ether, tetrahydrofuran, 1,4-dioxane, methoxybenzene, alkylene glycol monoalkyl ether and alkylene glycol dialkyl ether; ketone solvents such as acetone and methyl ethyl ketone; Amido solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide and N-methyl-2-pyrrolidone; Aprotic polar solvents such as xoxide and γ-butyrolactone; heterocyclic solvents such as pyridine, picoline, lutidine, quinoline, isoquinoline, sulfolane, 1,3-dioxolane, tetrahydrofuran and dioxane; phenolic solvents such as phenol and cresol; Other solvents such as alkyl carbitol acetate and benzoic acid ester are listed, but are not particularly limited. As a polymerization solvent, only 1 type can also be used and 2 or more types of solvents can also be mixed and used.

As the terminal group of the polyamic acid, an acid anhydride group or an amino group can be arbitrarily selected by using either one of 4,4′-oxydiphthalic anhydride and a diamine compound in excess during the polymerization reaction.

In the case where the terminal group is an acid anhydride terminal, the acid anhydride terminal may be left without performing the subsequent treatment, or may be hydrolyzed to obtain a dicarboxylic acid. Moreover, it is good also as ester using C4 or less alcohol. Furthermore, you may seal a terminal | end using a monofunctional amine compound and / or an isocyanate compound. The amine compound and / or isocyanate compound used here is not particularly limited as long as it is a monofunctional primary amine compound and / or isocyanate compound. For example, aniline, methylaniline, dimethylaniline, trimethylaniline, ethylaniline, diethylaniline, triethylaniline, aminophenol, methoxyaniline, aminobenzoic acid, biphenylamine, naphthylamine, cyclohexylamine, phenyl isocyanate, xylylene isocyanate, cyclohexyl isocyanate , Methylphenyl isocyanate, trifluoromethylphenyl isocyanate, and the like.

Further, when the terminal group is an amine terminal, it is possible to prevent the amino group from remaining at the terminal by sealing the terminal amino group with a monofunctional acid anhydride. As an acid anhydride used here, if it is a monofunctional acid anhydride which becomes dicarboxylic acid or tricarboxylic acid when hydrolyzed, it can be used without particular limitation. For example, maleic anhydride, methylmaleic anhydride, dimethylmaleic anhydride, succinic anhydride, norbornene dicarboxylic acid anhydride, 4- (phenylethynyl) phthalic anhydride, 4-ethynylphthalic anhydride, phthalate Acid anhydride, methylphthalic anhydride, dimethylphthalic anhydride, trimellitic anhydride, naphthalenedicarboxylic anhydride, 7-oxabicyclo [2.2.1] heptane-2,3-dicarboxylic anhydride, bicyclo [2.2.1] Heptane-2,3-dicarboxylic anhydride, bicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic anhydride, 4-oxatricyclo [5.2 .2.0 ^2,6] undecane-3,5-dione, octahydro-1,3-dioxo-isobenzofuran-5-carboxylic acid, hexahydrophthalic anhydride Methylhexahydrophthalic anhydride, dimethylcyclohexanedicarboxylic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, methyl-4-cyclohexene-1,2-dicarboxylic anhydride, etc. .

Here, the polyimide is a method in which the polyamic acid solution is heated to imidize the polyamic acid (thermal imidization method), or a polycyclic acid (imidation catalyst) is added to the polyamic acid solution to imidize the polyamic acid. It can be obtained by a method (chemical imidization method).

In the thermal imidization method, the polyamic acid in the polymerization solvent is heated for 1 to 200 hours in a temperature range of, for example, 80 to 300 ° C. to advance imidization. Further, the temperature range is preferably 150 to 200 ° C., and by setting the temperature range to 150 ° C. or higher, imidization can be reliably progressed and completed. It is possible to prevent an increase in resin concentration due to oxidation of unreacted raw materials and volatilization of the solvent solvent.

Furthermore, in the thermal imidization method, an azeotropic solvent can be added to the polymerization solvent in order to efficiently remove water generated by the imidization reaction. As an azeotropic solvent, for example, aromatic hydrocarbons such as toluene, xylene, and solvent naphtha, and alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and dimethylcyclohexane can be used. When an azeotropic solvent is used, the amount added is about 1 to 30% by mass, preferably 5 to 20% by mass, based on the total amount of organic solvent.

On the other hand, in the chemical imidization method, a known ring closure catalyst is added to the polyamic acid in the polymerization solvent to advance imidization. As the ring-closing catalyst, pyridine may generally be used. In addition to this, for example, substituted or unsubstituted nitrogen-containing heterocyclic compounds (eg, picoline, quinoline, imidazole, etc.), N-oxides of nitrogen-containing heterocyclic compounds Compounds, substituted or unsubstituted amino acid compounds, aromatic hydrocarbon compounds having a hydroxy group, or aromatic heterocyclic compounds, particularly 1,2-dimethylimidazole, N-methylimidazole, N-benzyl-2-methylimidazole Lower alkyl imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 5-methylbenzimidazole, imidazole derivatives such as N-benzyl-2-methylimidazole, isoquinoline, 3,5-dimethylpyridine, 3, 4-dimethylpyridine, 2,5-dimethylpi Jin, 2,4-dimethyl pyridine, substituted pyridine, such as 4-n-propyl pyridine, can be suitably used p- toluenesulfonic acid and the like. The addition amount of the ring closure catalyst is preferably about 0.01 to 2 times equivalent, particularly about 0.02 to 1 time equivalent to the amic acid unit of the polyamic acid. By using a ring-closing catalyst, the properties of the resulting polyimide, particularly elongation and breaking resistance, may be improved.

In the thermal imidization method or chemical imidization method, a dehydrating agent may be added to the polyamic acid solution. Examples of such a dehydrating agent include aliphatic acid anhydrides such as acetic anhydride, phthalates, and the like. Examples thereof include aromatic acid anhydrides such as acid anhydrides, and these can be used alone or in combination. In addition, it is preferable to use a dehydrating agent because the reaction can proceed at a low temperature. Although it is possible to imidize polyamic acid only by adding a dehydrating agent to the polyamic acid solution, it is preferable to imidize by heating or addition of a ring-closing catalyst as described above because the reaction rate is slow. .

In addition, as described later, the polyimide is subjected to a heat treatment (thermal imidization method) on a film in which a polyamic acid solution is cast, or a polyamic acid solution mixed with a ring closure catalyst is cast on a support. Then, it can be obtained in a film state by imidization (chemical imidization method). Specific examples of the ring-closing catalyst include aliphatic tertiary amines such as trimethylamine and triethylenediamine, and heterocyclic tertiary amines such as isoquinoline, pyridine and picoline, and are selected from heterocyclic tertiary amines. It is preferred to use at least one amine. The content of the cyclization catalyst relative to the polyamic acid is preferably in the range where the content of the cyclization catalyst (mole) / polyamic acid content (mole) is 0.5 to 8.0.

The polyamic acid or polyimide constituted as described above preferably has a weight average molecular weight of 30,000 to 1,000,000 from the viewpoint of forming a film. In the present invention, the weight average molecular weight refers to a value in terms of polyethylene glycol by size exclusion chromatography (SEC).

Alternatively, the ring-closed polyimide may be reprecipitated using a poor solvent or the like, purified to a solid, dissolved in a solvent, cast and dried, and then formed into a film.

According to this method, the polymerization solvent and the solvent to be cast can be made different types, and the performance of the polyimide film can be further extracted by selecting the optimum solvent for each.

For example, in order to increase the molecular weight of polyamic acid, it is polymerized and cyclized with dimethylacetamide, solidified with methanol, dried, then made into a solution containing an additive with dichloromethane, then cast and dried. Thus, high molecular weight and low temperature drying are possible.

Also, when dichloromethane is used as a solvent, it can be used in combination with other solvents. A co-solvent such as tetrahydrofuran (THF), dioxolane, cyclohexanone, cyclopentanone, γ-butyrolactone, ethanol, methanol, butanol, or isopropyl alcohol can be used as appropriate.

The polyamic acid may be imidized at the time of casting, and the imidization rate at the time of casting is preferably 10 to 100%. Here, as the imidization rate, the imidization rate can be determined by measuring the residual amount of carboxy group from the ¹ H-NMR spectrum.

[1.2] Polyimide 2
Polyimide 2 that can be preferably used for the polyimide film of the present invention is (A) 4,4′-oxydiphthalic dianhydride (2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride. And (B) one or more diamines and / or diisocyanates represented by the following general formulas (2.1) to (2.3).

In the general formulas (2.1) to (2.3), X represents an amino group or an isocyanate group. R ¹ to R ⁸ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. In the general formula (2.1), at least one of R ¹ to R ⁴ is not a hydrogen atom. In the general formula (2.2), at least one of R ¹ to R ⁴ is not a hydrogen atom. In the general formula (2.3), at least one of R ⁵ to R ⁸ is not a hydrogen atom.

Polyimide 2 is superior in heat resistance, transparency and heat yellowing resistance as compared with conventional polyimide, and also has an advantage of excellent storage stability and mechanical strength.

The end group of polyimide 2 is preferably not an amine end. By not using an amine terminal, it is possible to avoid the point that when the terminal group of the polyimide 2 is an amino group, it easily interacts with the imide carbonyl group to form a charge transfer complex. In addition, the amino group is susceptible to oxidation, and it is possible to avoid the point of forming a chromophore by oxidation with time and lowering transparency and heat yellowing. Specifically, the terminal group of the polyimide 2 can be made not to be an amine terminal by a method similar to the above method.

As the component (B), diethyltoluene in which two of R ¹ to R ^{4 in} the general formula (2.1) or (2.2) are an ethyl group, and the remaining two are a methyl group and a hydrogen atom Diamine (DETDA) is preferred. In the general formula (2.3), R ⁵ to R ⁸ are preferably each independently an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 2 to 3 carbon atoms. .

By using these monocyclic or bicyclic raw materials, the concentration of the imide group in the main chain of polyimide 2 can be increased, and by introducing a bulky substituent at the ortho position of the amino group, intermolecular mutual By weakening the action, formation of the charge transfer complex can be inhibited, and both transparency and solvent solubility can be achieved.

In copolymerizing the polyimide 2, in addition to the component (A) and the component (B), (C) a second acid dianhydride, and / or (D) a second diamine and / or diisocyanate, May be obtained by copolymerization.

As the second acid dianhydride as the component (C), any acid dianhydride conventionally used in the production of polyimide can be used without any particular limitation. For example, as a general aromatic acid dianhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride Anhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 2,3,2', 3'-biphenyltetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylmethane Tetracarboxylic dianhydride, 2,3,3 ', 4'-diphenylmethanetetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 2,3,3 ', 4'-benzophenone tetracarboxylic dianhydride, 2,3,2 ', 3'-benzophenone tetracarboxylic dianhydride, 3,4'-oxydiphthalic dianhydride, 4,4'-oxydiphthalic dianhydride 3,3'- Xydiphthalic dianhydride, diphenylsulfone-3,4,3 ', 4'-tetracarboxylic dianhydride, diphenylsulfone-2,3,3', 4'-tetracarboxylic dianhydride, diphenylsulfone-2 , 3,2 ', 3'-tetracarboxylic dianhydride, 4,4'-[isopropylidenebis [(1,4-phenylene) oxy]] diphthalic dianhydride, 5,5'-isopropylidenebis (Phthalic anhydride), 3,5'-isopropylidenebis (phthalic anhydride), 3,3'-isopropylidenebis (phthalic anhydride), 4,4 '-(1,4-phenylenebisoxy) ) Bisphthalic dianhydride, 4,4 '-(1,3-phenylenebisoxy) bisphthalic dianhydride, 5,5'-[oxybis (4,1-phenyleneoxy)] bisphthalic dianhydride, 5 , '- [sulfonylbis (4,1-phenylene-oxy)] can be exemplified Bisufutaru acid dianhydride and the like. The silicon-containing acid dianhydrides include 4,4 ′-(dimethylsilylene) bis (phthalic acid) 1, 2: 1 ′, 2′-dianhydride, and 4,4 ′-(methylethylsilylene). Bis (phthalic acid) 1,2: 1 ', 2'-dianhydride, 4,4'-[phenyl (methyl) silylene] bisphthalic acid 1,2: 1 ', 2'-dianhydride, 4,4 Examples include '-diphenylsilylene bisphthalic acid 1,2: 1', 2'-dianhydride. Examples of fluorine-containing acid dianhydrides include 4,4 '-(2,2-hexafluoroisopropylidene) diphthalic dianhydride and 3,4'-(2,2-hexafluoroisopropylidene) diphthalic dianhydride. 3,3 '-(2,2-hexafluoroisopropylidene) diphthalic dianhydride, 4,4'-[2,2-hexafluoroisopropylidenebis [(1,4-phenylene) oxy]] diphthalate An acid dianhydride etc. can be mentioned. Examples of the fluorene cardoic acid dianhydride include 5,5 ′-[9H-fluorene-9,9-diylbis (4,1-phenyleneoxy)] bis (isobenzofuran-1,3-dione), 5,5 Examples include '-[9H-fluorene-9,9-diylbis (1,1'-biphenyl-5,2-diyloxy)] bis (isobenzofuran-1,3-dione). Examples of ester acid dianhydrides include ethylene glycol bis (trimellitic anhydride), 1,4-phenylene bis (trimellitate anhydride), 1,3-phenylene bis (trimellitate anhydride), 1,2-phenylene bis (trimellitate) Anhydride), bis (1,3-dihydro-1,3-dioxoisobenzofuran-5-carboxylic acid) -2-acetoxypropane-1,3-diyl, 5,5 '-[ethylenebis (oxy)] Bis (isobenzofuran-1,3-dione), bis (1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylic acid) oxybis (methyleneoxymethylene), 4,4 ′-[isopropylidenebis ( 4,1-phenyleneoxycarbonyl)] bisphthalic dianhydride and the like.

Aliphatic acid dianhydrides include 1,1'-bicyclohexane-3,3 ', 4,4'-tetracarboxylic dianhydride, 1,1'-bicyclohexane-2,3,3', 4'-tetracarboxylic dianhydride, 1,1'-bicyclohexane-2,3,2'3'-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride 1,2,3,4-tetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl) naphtho [1,2- c] furan-1,3-dione, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4 Cyclopentanetetracarboxylic dianhydride, 5- (2,5-dioxo Trahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride Bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid-2,3: 5,6-dianhydride, bicyclo [2.2.1] heptane-2,3,5 , 6-tetracarboxylic acid-2,3: 5,6-dianhydride, hexadecahydro-3a, 11a- (2,5-dioxotetrahydrofuran-3,4-diyl) phenanthro [9,10-c] And furan-1,3-dione.

Aliphatic ester acid dianhydrides include bis (1,3-dioxo-1,3,3a, 4,5,6,7,7a-octahydroisobenzofuran-5-carboxylic acid) biphenyl-4,4 '-Diyl, bis (1,3-dioxo-1,3,3a, 4,5,6,7,7a-octahydroisobenzofuran-5-carboxylic acid) 1,4-phenylene, bis (1,3- And dioxo-1,3,3a, 4,5,6,7,7a-octahydroisobenzofuran-5-carboxylic acid) -2-methyl-1,4-phenylene. Among them, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] octane-2,3,5,6 -Tetracarboxylic acid-2,3: 5,6-dianhydride, 4,4'-oxydiphthalic dianhydride, 4,4 '-(2,2-hexafluoroisopropylidene) diphthalic dianhydride, 3, , 3 ′, 4,4′-biphenyltetracarboxylic dianhydride is preferred from the viewpoints of heat resistance, solvent solubility and availability.
The second acid dianhydride as the component (C) may be used alone, or a mixture of two or more acid dianhydrides may be used, and the second acid dianhydride may be used. As a quantity of a thing, 2 mol or less is preferable with respect to 1 mol of (A) component.

In this case, as the second diamine and / or diisocyanate as the component (D), those usually used for the production of polyimide can be used.

Examples of the component (D) include those represented by the following general formulas (2.4) to (2.21) other than the same component as the component (B).

In the general formulas (2.4) to (2.21), X each independently represents —NH ₂ , —NCO, —CH ₂ NH ₂ or —CH ₂ NCO. R ¹ to R ⁸ each independently represent H, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydroxy group, a carboxy group, a trifluoromethyl group, or an aryl group. R ⁹ to R ¹² each independently represents an alkyl group having 1 to 4 carbon atoms or an aryl group. Y is independently

Represents. R ²¹ and R ²² are each independently H, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydroxy group, a carboxy group, or Represents a trifluoromethyl group.

In addition, when using what is different from the said (B) component as 2nd diamine and / or diisocyanate which are (D) components, the quantity is 2 mol or less with respect to 1 mol of (B) components.

Polyimide 2 is obtained by copolymerizing the component (A) and the component (B). In addition, the (A) component and the (B) component are copolymerized to obtain a polyimide copolymer unit having a weight average molecular weight of about 700 to 80000, and the obtained polyimide copolymer unit is subjected to (C ) Second acid dianhydride as component and / or (D) second diamine and / or diisocyanate as component may be copolymerized.

In the polyimide 2, the weight average molecular weight is preferably 20,000 to 200,000, more preferably 35,000 to 150,000. When the weight average molecular weight of the polyimide 2 is within the above range, the handleability is excellent.

The polyimide 2 is produced by a thermal imidization method in which the ring is thermally closed in a temperature range of 150 to 200 ° C. for 1 to 200 hours, and a chemical imide using a ring closing catalyst such as triethylamine, pyridine, picoline or quinoline. Any method such as chemical method may be used.

[1.3] Polyimide 3: fluorinated polyimide The polyimide used for the polyimide film of the present invention is preferably polyimide 3: fluorinated polyimide. Here, a fluorine-type polyimide refers to the polyimide which has a fluorine atom in a polyimide structure, and specifically has a fluorine-containing group in the diamine which is a polyimide raw material. As such a fluorine-based polyimide, for example, among those represented by the general formula (1.1), Φ in the formula is represented by the following general formula (3.1) or (3.2) 2 And those represented by a valent organic group.

In the general formulas (3.1) and (3.2), R ₁ to R ₈ are each independently a hydrogen atom, a fluorine atom, an alkyl group or an alkoxy group having 1 to 5 carbon atoms, or a fluorine-substituted hydrocarbon. Represents a group. In the general formula (3.1), at least one of R ₁ to R ₄ represents a fluorine atom or a fluorine-substituted hydrocarbon group. In the general formula (3.2), at least one of R ₁ to R ₈ represents a fluorine atom or a fluorine-substituted hydrocarbon group. Among these, preferred specific examples of R ₁ to R ₈ include —H, —CH ₃ , —OCH ₃ , —F, —CF _{3 and the} like, and at least one substituent is —F or CF _3. It is preferable that

Preferred examples of the specific diamine residue that gives Φ in the above general formula (1.1) include the following.

The fluorine-based polyimide 3 can be obtained by imidizing polyamic acid. Here, the polyamic acid resin solution is preferably obtained by reacting a raw material diamine and 4,4′-oxydiphthalic anhydride in an organic solvent using substantially equimolar amounts. More specifically, the polyamic acid resin solution is prepared by dissolving diamine in an organic polar solvent such as N, N-dimethylacetamide under a nitrogen stream, and then adding 4,4′-oxydiphthalic anhydride to room temperature. For about 5 hours. From the viewpoint of uniform film thickness during coating and the mechanical strength of the resulting polyimide film, the polyamic acid obtained preferably has a weight average molecular weight of 10,000 to 300,000.

[1.4] Polyimide 4
The polyimide used in the polyimide film of the present invention is also preferably polyimide 4 described below.

Polyimide 4 is obtained by polymerizing 4,4′-oxydiphthalic anhydride with a diamine component containing nitrogen-free aromatic diamine compound: 51 to 99 mol% and nitrogen-containing aromatic diamine compound: 1 to 49 mol%. It is the polyimide obtained by. Here, the nitrogen-free aromatic diamine compound refers to a diamine compound having an aromatic ring containing no nitrogen atom in the molecule and no aromatic ring containing a nitrogen atom. The nitrogen-containing aromatic diamine compound refers to a diamine compound having an aromatic ring containing a nitrogen atom in the molecule.

As the diamine component, the amount of the nitrogen-containing aromatic diamine compound is in the range of 1 to 49 mol%, thereby realizing both high elasticity and flexibility in the obtained polyimide and the polyimide film using the same, and realizing high mechanical strength. Can be preferred.

The amount of the nitrogen-containing aromatic diamine compound in the diamine component suppresses the undissolved residue of the nitrogen-containing aromatic diamine compound having low solubility during polymerization, and the resulting polyimide and the polyimide film using the polyimide have high elasticity and flexibility. From the viewpoint of realizing high mechanical strength, it is preferably 1 to 49 mol%, more preferably 1 to 30 mol%, still more preferably 1 to 20 mol%. % Or more and less than 20 mol% is particularly preferable.

Examples of nitrogen-containing aromatic diamine compounds include diaminophenylbenzimidazoles such as 5,4'-diamino-2-phenylbenzimidazole (DAPBI) and 2,5-diaminopyridine (DAPY). Although diaminopyridines etc. are mentioned, it is not limited to them, Each can be used individually or in combination of 2 or more types.

By introducing this nitrogen-containing aromatic diamine compound, its rigid molecular structure contributes to increasing the strength of the polyimide, and the imidization rate of the polyimide is improved by the nitrogen-containing aromatic ring acting as a catalyst during imidization of the polyamic acid. As a result of the improvement, it is considered that the mechanical strength of the polyimide is improved.

The amount of the nitrogen-free aromatic diamine compound in the diamine component is preferably 51 mol% or more and less than 99 mol%, more preferably 70 to 99 mol%, more preferably 80 to More preferably, it is 99 mol%, and it is especially preferable that it is more than 80 mol% and 99 mol% or less.

Examples of the nitrogen-free aromatic diamine compound include, for example, 4,4′-diaminodiphenyl ether (ODA), p-phenylenediamine (PDA), aliphatic diamine, alicyclic diamine, and the like. It can be used alone or in combination of two or more.

The acid component used for the polyimide 4 is 4,4'-oxydiphthalic anhydride, but other acid components may be used in combination. Examples of the other acid component include pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3 ′, 4,4 ′. Examples include, but are not limited to, benzophenone tetracarboxylic dianhydride (BTDA), alicyclic tetracarboxylic dianhydride, and the like.

The polyimide 4 can be mentioned as one of preferable embodiments that further contains a solvent. Examples of the solvent include N-methyl-2-pyrrolidone (NMP), N, N-dimethylacetamide, dimethyl sulfoxide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide and dimethyl. Examples thereof include sulfone, and these are preferably used alone or in combination.

In addition, when the nitrogen-containing aromatic diamine compound has low solubility in the above solvent, the reaction solution may be heated to 50 ° C. or lower in order to increase the solubility.

The nitrogen-containing aromatic diamine compound is an aromatic diamine compound having an imidazole ring or a pyridine ring, and is composed of 5,4′-diamino-2-phenylbenzimidazole (DAPBI) and 2,5-diaminopyridine (DAPY). At least one selected from the group, wherein the nitrogen-free aromatic diamine compound is selected from the group consisting of p-phenylenediamine, 4,4'-diaminodiphenyl ether and 3,4'-diaminodiphenyl ether It is preferable that

Polyimide 4 is produced by using a non-nitrogen-containing aromatic diamine compound: 51 to 99 mol% and a nitrogen-containing aromatic diamine compound: 1 to 49 mol%, a diamine component, and an acid component 4,4′- There is no particular limitation other than polymerizing oxydiphthalic anhydride.

One preferred embodiment is that a solvent is further used when the polyimide 4 is produced. For example, an acid component (4,4′-oxydiphthalic anhydride) and a diamine component (aromatic diamine component) are added in a solvent (the acid component and the diamine component can be used in amounts that are approximately equimolar). Can be obtained by mixing these to form a mixture and polymerizing the mixture. If necessary, the mixture can further contain additives described later.

The conditions for polymerizing the mixture are not particularly limited. For example, a mixture obtained by adding a diamine component containing a nitrogen-free aromatic diamine compound and a nitrogen-containing aromatic diamine compound and 4,4′-oxydiphthalic anhydride to the above-described solvent is mixed at room temperature to 50 ° C. There is a method of producing a polyamic acid solution by stirring and reacting under atmospheric pressure under conditions.

In the above production method, the polyamic acid (copolymerized polyamic acid) is preferably prepared at a ratio (concentration) of 10 to 30% by mass in the solvent.

The polyamic acid produced as described above is not particularly limited with respect to its molecular structure. For example, a random copolymer, an alternating copolymer, and a block copolymer are mentioned.

The polyimide 4 can further contain an additive. Examples of the additive include a dehydrating agent and a ring-closing catalyst used for imidizing polyamic acid into a polyimide.

[2] Hydrogen bonding compound The polyimide film of the present invention contains a hydrogen bonding compound having an aromatic ring and a hydrogen bond donor site in the molecule.
In the present invention, the hydrogen bonding compound means a compound having a hydrogen bonding donor site in the molecule (meeting the requirements defined in the following (I)) and capable of forming a hydrogen bond with other compounds. Further, the hydrogen bond donor site refers to a site that forms a hydrogen bond by supplying a hydrogen atom.
Further, the hydrogen bonding compound preferably satisfies the requirements specified in the following (II) and (III).

(I) It has a hydrogen bond donor site in the molecule.
(II) The value obtained by dividing the molecular weight by the molecular weight of the hydrogen bond donor site is in the range of 5 to 65.
(III) The total number of aromatic rings is 1-8.

First, the requirement (I) will be described.
In the hydrogen bonding compound used in the present invention, examples of the functional group acting as a hydrogen bonding donor site include Jeffrey, George A. et al. It is described in Table 2 on page 15 of “Introduction to Hydrogen Bonding” published by Oxford UP. In the present invention, the total number of functional groups described in the table in the hydrogen bonding compound is used as the number of hydrogen bonding donor sites.
As a hydrogen bondable compound used for this invention, the compound which has a hydroxyl group etc. as a hydrogen bond donor site | part is mentioned, for example.

The hydrogen bonding compound used in the present invention has a hydrogen bond donor site in the molecule, thereby forming a strong hydrogen bond with an ether bond in the polyimide main chain structure which is a hydrogen bond acceptor site. Can be suppressed. Here, the hydrogen bond acceptor site refers to a site that accepts a hydrogen atom to form a hydrogen bond.

Next, the requirement (II) will be described.
The value obtained by dividing the molecular weight of the hydrogen bonding compound according to the present invention by the molecular weight of the hydrogen bonding donor site is preferably within the range of 5 to 65. When the value is 5 or more, hydrogen bonding to an ether bond is likely to occur, and the effect of the present invention is easily manifested. When the value is 65 or less, association between hydrogen bonding compounds hardly occurs and the effect of the present invention is easily manifested. Become.

Next, the requirement (III) will be described.
The number of aromatic rings in the hydrogen bonding compound according to the present invention is preferably 1-8. When the number of aromatic rings is 1 or more, the effect of the present invention is obtained, and when it is 8 or less, hydrogen bonding to an ether bond is likely to occur, and the effect of the present invention is easily exhibited.

Here, the aromatic ring is a ring in which the number of π electrons satisfies 4n + 2 (n is a natural number), and may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. Examples of the aromatic ring include a benzene ring, naphthalene ring, anthracene ring, azulene ring, phenanthrene ring, triphenylene ring, pyrene ring, chrysene ring, naphthacene ring, perylene ring, pentacene ring, hexacene ring, coronene ring, trinaphthylene ring, furan Ring, thiophene ring, pyrrole ring, imidazole ring, pyrazole ring, 1,2,4-triazole ring, 1,2,3-triazole ring, oxazole ring, thiazole ring, isoxazole ring, isothiazole ring, furazane ring, pyridine Ring, pyrazine ring, pyrimidine ring, pyridazine ring, indolizine ring, quinoline ring, isoindole ring, indole ring, isoquinoline ring, phthalazine ring, purine ring, naphthyridine ring, quinoxaline ring, quinazoline ring, cinnoline ring, pteridine ring, carbazole Ring Nantorijin ring, acridine ring, perimidine ring, phenanthroline ring, phenazine ring, and the like.
The number of aromatic rings is counted as one condensed ring when the aromatic rings are condensed, and when each aromatic ring is linked via a linking group, each aromatic ring is counted as Count as one. For example, an aromatic ring having 10 carbon atoms derived from naphthalene is counted as one aromatic ring.

As the hydrogen bonding compound according to the present invention, the value obtained by dividing the number of aromatic rings by the number of hydrogen bonding donor sites is preferably within the range of 1 to 5 from the viewpoint of manifesting the effects of the present invention.

Next, a specific structure of the hydrogen bonding compound used in the present invention will be described.
The hydrogen bonding compound used in the present invention is preferably a compound represented by the following general formulas (A) to (H). Each structure will be described in detail below.

[2.1] Hydrogen Bonding Compound Represented by General Formula (A) The hydrogen bonding compound according to the present invention is preferably a compound represented by the following general formula (A).

In general formula (A), Ra represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group, or an aryl group. X ¹ , X ² , X ³ and X ⁴ each independently represent a single bond or a divalent linking group. R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group.

Ra in the general formula (A) represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group, and is preferably an alkyl group or an aryl group. When Ra is an alkyl group, it preferably has 1 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. When Ra is an alkenyl group, it preferably has 2 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. When Ra is an alkynyl group, it preferably has 2 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. When Ra is an aryl group, it preferably has 6 to 24 carbon atoms, and more preferably 6 to 18 carbon atoms. When Ra is a heterocyclic group, it preferably has 5 to 23 carbon atoms, and more preferably 5 to 17 carbon atoms.

X ¹ , X ² , X ³ and X ⁴ in the general formula (A) each independently represent a single bond or a divalent linking group, more preferably each independently a single bond, and all are single bonds. It is particularly preferred.

Examples of the divalent linking group that may be independently represented by X ¹ , X ² , X ³ and X ^{4 in the} general formula (A) include, for example, a divalent group represented by the following general formula (P) Linking group, alkylene group (preferably having 1 to 30 carbon atoms, more preferably 1 to 3 carbon atoms, particularly preferably 2 carbon atoms), arylene group (preferably having 6 to 30 carbon atoms, more preferably 6 to 6 carbon atoms). 10). Among them, a divalent linking group represented by the following general formula (P) is preferable, and a carbonyl group is more preferable.

In general formula (P), the * side is a linking site with a nitrogen atom substituted on the 1,3,5-triazine ring in the compound represented by general formula (A).

[2.2] Hydrogen Bonding Compound Represented by General Formula (B) The hydrogen bonding compound according to the present invention is preferably a compound represented by the following general formula (B).

In general formula (B), Rb and Rc each independently represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ⁵ and X ⁶ each independently represent a single bond or a divalent linking group. R ⁵ and R ⁶ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group.

Rb and Rc in the general formula (B) each independently represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group, and a preferred range thereof is the same as the preferred range of Ra in the general formula (A). It is.

X ⁵ and X ⁶ in the general formula (B) each independently represent a single bond or a divalent linking group, and preferred ranges thereof are those of X ¹ , X ² , X ³ and X ^{4 in} the general formula (A). This is the same as the preferred range.

R ⁵ and R ⁶ in the general formula (B) each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and a preferred range is R ¹ in the general formula (A). , R ² , R ³ and R ⁴ are the same as the preferred ranges.

Specific examples of the compound represented by the general formula (A) or (B) include compounds described in paragraph numbers 0055 to 0057 of JP2012-82235A.

Further, the method for producing the compound represented by the general formula (A) or (B) is not particularly limited, and can be produced by a known method. Examples of the production method preferably used in the present invention include, for example, US Pat. No. 3,478,026 and Chem. Eur. J. et al. As described in 2005, 11, 6616-6628, a method of forming a triazine ring by heating dicyanodiamide and a nitrile compound in an alcohol in the presence of an inorganic base such as potassium hydroxide. Also, for example, as described in Tetrahedron 2000, 56, 9705-9711, there is a method in which a Grignard compound and an amine compound are subjected to a stepwise substitution reaction using cyanuric chloride as a raw material. Furthermore, monoamino-disubstituted-s-triazines can be obtained by reaction of imidoylguanidine with carboxylic acid chloride or ester as described in, for example, Journal of Synthetic Organic Chemistry, Vol. 1967, Vol. 25, No. 11, 1048-1051. A synthesis method can also be used.

[2.3] Hydrogen Bonding Compound Represented by General Formula (C) or (D) The hydrogen bonding compound according to the present invention is preferably a compound represented by the following general formula (C). .

In the general formula (C), Ra ¹¹ represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. Rb ¹¹ , Rc ¹¹ , Rd ¹¹ and Re ¹¹ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. Q ¹ represents an oxygen atom, a sulfur atom or NRf, and Rf represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and may combine with Ra ¹¹ to form a ring. good. X ¹¹ , X ¹² and X ¹³ each independently represent a single bond or a divalent linking group. X ¹⁴ represents a linking group selected from divalent bridging group group represented by the general formula (P).

In addition, the hydrogen bonding compound according to the present invention is preferably a compound represented by the following general formula (D).

In the general formula (D), Ra ²¹ and Rg ²¹ each independently represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group. Rd ²¹ and Re ²¹ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. Q ¹¹ represents an oxygen atom, a sulfur atom or NRf, and Rf represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and may combine with Ra ²¹ to form a ring. good. Q ¹² represents an oxygen atom, a sulfur atom or NRh, and Rh represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and may be linked to Rg ²¹ to form a ring. good. X ²³ represents a single bond or a divalent linking group. X ²⁴ represents a linking group selected from the divalent linking group group represented by the general formula (P).

Specific examples of the compound represented by the general formula (C) or (D) include compounds described in paragraph numbers 0068 to 0071 of JP2012-82235A.

[2.4] Hydrogen Bonding Compound Represented by General Formula (E) or (F) The hydrogen bonding compound according to the present invention is preferably a compound represented by the following general formula (E). .

In the general formula (E), ^{Y 1} represents a methine group or a nitrogen atom. Ra ³¹ represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. Rb ³¹ , Rc ³¹ , Rd ³¹ and Re ³¹ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. Q ²¹ represents a single bond, an oxygen atom, a sulfur atom or NRf, Rf represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and is linked to Ra ³¹ to form a ring. You may do it. X ^31, ^{X 32} and ^{X 33} represents a single bond or a divalent linking group independently. X ³⁴ represents a linking group selected from the group consisting of divalent linking groups represented by the general formula (P).

In addition, the hydrogen bonding compound according to the present invention is preferably a compound represented by the following general formula (F).

In the general formula ^{(F), Y 11} represents a methine group or a nitrogen atom. Ra ⁴¹ and Rg ⁴¹ each independently represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. Rd ⁴¹ and Re ⁴¹ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. Q ³¹ represents an oxygen atom, a sulfur atom or NRf, and Rf represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and may combine with Ra ⁴¹ to form a ring. good. Q ³² represents an oxygen atom, a sulfur atom or NRh, and Rh represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and may combine with Rg ⁴¹ to form a ring. good. X ⁴³ represents a single bond or a divalent linking group. X ⁴⁴ represents a linking group selected from the group consisting of divalent linking groups represented by the general formula (P).

Specific examples of the compound represented by the general formula (E) or (F) include compounds described in paragraph numbers 0083 to 0091 of JP2012-82235A.

[2.5] Hydrogen Bonding Compound Represented by General Formula (G) The hydrogen bonding compound according to the present invention is preferably a compound represented by the following general formula (G).

In General Formula (G), L ¹ represents a divalent linking group containing a single bond or a hetero atom. R ⁸¹ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryl group having 7 to 20 carbon atoms. Represents an alkyl group.

Specific examples of the compound represented by the general formula (G) include the compounds described in paragraph numbers 0109 to 0111 of JP2012-82235A.

[2.6] Hydrogen Bonding Compound Represented by General Formula (H) The hydrogen bonding compound according to the present invention is preferably a compound represented by the following general formula (H).

In the general formula (H), L ³ represents a divalent linking group containing a single bond or a hetero atom. R ⁸⁵ represents an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms. To express. R ⁸³ and R ⁸⁴ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. X ⁵³ and X ⁵⁴ each independently represent a linking group selected from the group consisting of a divalent linking group represented by the above general formula (P).

Specific examples of the compound represented by the general formula (H) include, for example, compounds described in paragraph No. 0113 of JP2012-82235A.

[2.7] Others The compounds represented by the above general formulas (A) to (H) preferably have a molecular weight of 100 to 1000, more preferably 150 to 700, and 150 to 450. Is most preferred.

The effect of the present invention can be obtained even if the hydrogen bonding compound is added at any timing before the polyimide is formed into a film. From the viewpoint of operability, the hydrogen bonding compound is hydrogen bonded to the imidized polyimide solution. It is preferable to add a functional compound.

It should be noted that the hydrogen bonding compound according to the present invention is not limited to the compounds represented by the general formulas (A) to (H).

[3] Other Additives The polyimide film of the present invention has, for example, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated silica to improve handling properties. It is preferable to contain a matting agent such as inorganic fine particles such as calcium acid, aluminum silicate, magnesium silicate, and calcium phosphate, and a crosslinked polymer. Of these, silicon dioxide is preferable because it can reduce the haze of the film.

The primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 5 to 16 nm, and particularly preferably 5 to 12 nm.

These fine particles preferably form secondary particles having a particle size of 0.1 to 5 μm and are contained in the polyimide. A preferable average particle size is 0.1 to 2 μm, and more preferably 0.2 to 0.00. 6 μm. As a result, irregularities having a height of about 0.1 to 1.0 μm are formed on the film surface, thereby providing appropriate slipperiness to the film surface.

The primary average particle diameter of the fine particles used in the present invention is measured by observing the particles with a transmission electron microscope (magnification of 500,000 to 2,000,000 times), observing 100 particles, measuring the particle diameter, and measuring the average. Let the value be the primary average particle size.

The additive contained in the polyimide film of the present invention is not limited to the fine particles.

[4] Imidization treatment of film When a cast film is formed using polyamic acid, a polyimide film can be produced by applying an imidization treatment to the obtained film.

The polyimide film of the present invention is cast into a polyamic acid solution containing no ring-closing catalyst, formed into a film, heated and dried on a support, then peeled off from the support, and further subjected to a drying heat treatment at a high temperature. It can manufacture using the thermal imidation method which imidizes by this. In the case of this method, the reaction rate of imidization can be improved by adding a dehydrating agent to the polyamic acid solution, but it is preferable not to include a dehydrating agent. By not including a dehydrating agent, it is possible to suppress a decrease in durability of the polyimide film due to the residual dehydrating agent.
In addition, the polyimide film of the present invention is cast into a film by casting a solution of a polyamic acid containing a ring closure catalyst and a dehydrating agent, and after partially imidizing on the support to form a film, The film can be peeled off from the support, heat-dried / imidized, and manufactured using a chemical imidization method in which heat treatment is performed. As the ring-closing catalyst, the above-mentioned tertiary amine or the like can be used. In the case of this method, since the imidization can proceed at a low temperature by adding a dehydrating agent to the polyamic acid solution, it is possible to suppress a decrease in durability of the polyimide film.

In the thermal imidization method, heat treatment can be performed by using, for example, an infrared heater.
As the infrared heater, for example, a heater main body formed so that a filament is surrounded by an inner tube is covered with an outer tube, and a cooling fluid can be circulated between the heater main body and the outer tube. The filament is energized and heated to 700 to 1200 ° C., and emits infrared light having a peak at a wavelength of about 3 μm. The inner tube and the outer tube are made of quartz glass, borosilicate crown glass, or the like, and function as a filter that passes infrared light having a wavelength of 3.5 μm or less and absorbs infrared light having a wavelength exceeding 3.5 μm. Such infrared heaters irradiate the film with infrared light having a wavelength of 3.5 μm or less through an inner tube or an outer tube when infrared light having a peak near 3 μm is emitted from the filament. By irradiating with infrared rays having this wavelength, the mixed solvent in the film can be efficiently evaporated and the polyamic acid in the film can be imidized. The inner tube and the outer tube absorb infrared rays having a wavelength exceeding 3.5 μm, but are cooled by the cooling fluid flowing through the flow path, so that the temperature can be maintained below the ignition point of the mixed solvent evaporating from the film. Is possible.

In the method for producing a polyimide film of the present invention, any of the above ring closure methods may be adopted, but the chemical imidization method requires equipment for containing a ring closure catalyst and a dehydrating agent in the polyamic acid solution. It can be said that it is a more preferable method in that a film having supportability can be obtained in a short time.

[5] Manufacturing method of polyimide film A specific example of the manufacturing method of the polyimide film will be described below.

As a method for producing a polyimide film, the above-described polyamic acid or polyimide is dissolved in a solvent to prepare a dope (dope preparation step), and the dope is cast on a support to form a cast film. (Casting step), a step of evaporating the solvent from the cast film on the support (solvent evaporation step), a step of peeling the cast film from the support (peeling step), and a step of drying the obtained film (first step) 1 drying step), a step of stretching the film (stretching step), a step of further drying the stretched film (second drying step), a step of winding up the obtained polyimide film (winding step), and if necessary For example, it is preferable to have a step (heating step) of heating the film to imidize it.
Hereinafter, each step will be specifically described.

[5.1] Dope preparation step The method for producing a polyimide film of the present invention is prepared by dissolving at least polyimide and a hydrogen bonding compound in a low boiling point solvent to prepare a dope, and using the dope, a solution casting film forming method is used. It is preferable to form a film.

As the low boiling point solvent, a low boiling point solvent having a boiling point of 80 ° C. or lower is preferably used as the main solvent. Here, “used as a main solvent” means that if it is a mixed solvent, 55% by mass or more is used with respect to the total amount of the solvent, preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably. Is 90% by mass or more. Of course, if it is used alone, it becomes 100% by mass.

The low boiling point solvent only needs to dissolve polyimide, a hydrogen bonding compound and other additives at the same time. For example, as the chlorinated solvent, dichloromethane, as the non-chlorinated solvent, methyl acetate, ethyl acetate, acetic acid Amyl, acetone, methyl ethyl ketone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2- Propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane, methanol, ethanol, n Propanol, iso- propanol, n- butanol, sec- butanol, tert- butanol and the like.

Among them, as the low boiling point solvent having a boiling point of 80 ° C. or less, among the above solvents, dichloromethane (40 ° C.), ethyl acetate (77 ° C.), methyl ethyl ketone (79 ° C.), tetrahydrofuran (66 ° C.), acetone (56.5 ° C.) And at least one selected from 1,3-dioxolane (75 ° C.) as a main solvent (the parentheses each represent a boiling point).

Moreover, as a solvent contained in the case of a mixed solvent, as long as it can dissolve the polyimide and the hydrogen bonding compound according to the present invention, it can be used within a range not impairing the effects of the present invention. Examples of other solvents include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, N-methylcaprolactam, hexamethylphospho Luamide, tetramethylene sulfone, dimethyl sulfoxide, m-cresol, phenol, p-chlorophenol, 2-chloro-4-hydroxytoluene, diglyme, triglyme, tetraglyme, dioxane, γ-butyrolactone, dioxolane, cyclopentanone, epsilon Caprolactam, Chloroform or the like can be used, and may be used in combination of two or more. In addition to these solvents, a poor solvent such as hexane, heptane, benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene may be used to the extent that the polyimide and the hydrogen bonding compound according to the present invention do not precipitate. good.

Also, an alcohol solvent can be used. It is preferable that the alcohol solvent is selected from methanol, ethanol and butanol from the viewpoint of improving peelability and enabling high-speed casting. Of these, methanol or ethanol is preferably used. When the ratio of the alcohol in the dope increases, the web gels and peeling from the metal support becomes easy.

For dissolving polyimide, hydrogen bonding compounds, and other additives, a method performed at normal pressure, a method performed below the boiling point of the main solvent, a method performed under pressure above the boiling point of the main solvent, and the production of a cellulose acylate film Japanese Patent Application Laid-Open No. 9-95544, Japanese Patent Application Laid-Open No. 9-95557, or Japanese Patent Application Laid-Open No. 9-95538, a method of performing a high temperature described in Japanese Patent Application Laid-Open No. 11-21379, etc. Various dissolution methods can be used, and a method of pressurizing at a temperature equal to or higher than the boiling point of the main solvent is particularly preferable.

The prepared dope is guided to a filter by a liquid feed pump or the like and filtered. For example, when the main solvent of the dope is dichloromethane, the gel-like foreign matter in the dope can be removed by filtering the dope at a temperature of boiling point at 1 atm of the dichloromethane + 5 ° C. or more. A preferred temperature range is 45 to 120 ° C, more preferably 45 to 70 ° C, and even more preferably 45 to 55 ° C.

In many cases, the main dope may contain about 10 to 50% by mass of the recycled material.
Return material means a part that is reused as a raw material for some reason, for example, a product obtained by finely pulverizing a polyimide film, which is generated when a polyimide film is formed and both sides of the film are cut off. Also, a polyimide film raw material or the like that exceeds the specified value of the film due to scratches or the like is used.

Further, as a raw material for the resin used for preparing the dope, a material obtained by pelletizing polyimide and other compounds in advance can be preferably used.

[5.2] Casting film forming step An endless support, such as a stainless steel belt or a rotating metal, that feeds the prepared dope to a die through a liquid feed pump (for example, a pressurized metering gear pump) A dope is cast from a die at a casting position on a metal support such as a drum.

The metal support in casting (cast) is preferably a mirror-finished surface, and the support is a stainless steel belt or a drum whose surface is plated with a casting, or a metal support such as a stainless steel belt or a stainless steel belt. Is preferably used. The cast width can be in the range of 1 to 4 m, preferably in the range of 1.5 to 3 m, more preferably in the range of 2 to 2.8 m. The support may not be made of metal, for example, polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polybutylene terephthalate (PBT) film, nylon 6 film, nylon 6,6 film, polypropylene film. A belt made of polytetrafluoroethylene or the like can be used.

The running speed of the metal support is not particularly limited, but is usually 5 m / min or more, preferably 10 to 180 m / min, particularly preferably 80 to 150 m / min. As the traveling speed of the metal support increases, entrained gas is more likely to be generated, and the occurrence of film thickness unevenness due to disturbance is more pronounced.
The traveling speed of the metal support is the moving speed of the outer surface of the metal support.

The surface temperature of the metal support is not particularly limited, but is usually 0 ° C. or higher, preferably 20 to 60 ° C., more preferably 20 to 25 ° C.

The die has a shape that becomes gradually narrower toward the discharge port in the vertical cross section with respect to the width direction. In general, the die usually has tapered surfaces on the downstream side and the upstream side in the lower traveling direction, and a discharge port is formed in a slit shape between the tapered surfaces. A die made of metal is preferably used, and specific examples include stainless steel, titanium, and the like. In the present invention, when manufacturing films having different thicknesses, it is not necessary to change to dies having different slit gaps.

¡It is preferable to use a pressure die that can adjust the slit shape of the die base and easily make the film thickness uniform. Examples of the pressure die include a coat hanger die and a T die, and any of them is preferably used. Even when films with different thicknesses are continuously manufactured, the discharge rate of the dies is maintained at a substantially constant value. Therefore, when a pressure die is used, conditions such as extrusion pressure and shear rate are also substantially reduced. Maintained at a constant value. In order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided and laminated.

Discharge rate of the dope from the die is preferably 200 ~ 720g / ^{m 2,} more preferably 400 ~ 650g / ^{m 2.} In the present invention, even when films having different thicknesses are continuously produced, it is preferable that the dope discharge amount from the die is maintained at a substantially constant value within the above range. When the ejection amount is 200 g / m ² or more, since the casting film is hardly affected by disturbance such as vibration and wind, it is possible to sufficiently prevent uneven thickness. When the discharge amount is 720 g / m ² or less, the shrinkage does not occur excessively and the film thickness unevenness due to the contraction does not occur, and thus the film thickness unevenness can be sufficiently prevented.

[5.3] Solvent evaporation step The solvent evaporation step is a pre-drying step which is performed on the metal support and the cast film is heated on the metal support to evaporate the solvent.

In order to evaporate the solvent, for example, a method of blowing heated air from the casting membrane side and the back side of the metal support by a dryer, a method of transferring heat from the back side of the metal support by a heating liquid, a method of transferring heat from the front and back by radiant heat Etc. A method of appropriately selecting and combining them is also preferable. The surface temperature of the metal support may be the same as a whole or may vary depending on the position. The temperature of the heating air is preferably 10 to 80 ° C.

In the method of heating the metal support, a higher temperature is preferable because the drying speed of the cast film can be increased. However, if the temperature is too high, the cast film may foam or the planarity may deteriorate. Therefore, it is preferably performed at 10 to 30 ° C.

In the solvent evaporation step, it is preferable to dry the cast film until the residual solvent amount is 10 to 150% by mass from the viewpoint of the peelability of the cast film and the transportability after peeling.

In the present invention, the residual solvent amount can be expressed by the following formula.
Residual solvent amount (% by mass) = {(MN) / N} × 100
Here, M is the mass at a predetermined point of the casting membrane (film), and N is the mass when M is dried at 200 ° C. for 3 hours. In particular, M when calculating the amount of residual solvent achieved in the solvent evaporation step is the mass of the cast film immediately before the peeling step.

[5.4] Stripping process The cast film from which the solvent has evaporated on the metal support is stripped at the stripping position.

The peeling tension when peeling the metal support from the casting film is usually in the range of 60 to 400 N / m. However, if wrinkles are likely to occur during peeling, peeling is performed with a tension of 190 N / m or less. It is preferable.

In the present invention, the temperature at the peeling position on the metal support is preferably in the range of −50 to 60 ° C., more preferably in the range of 10 to 40 ° C., and in the range of 15 to 40 ° C. Is most preferred.

The peeled film may be sent directly to the stretching process, or may be sent to the stretching process after being sent to the first drying process so as to achieve a desired residual solvent amount. In the present invention, from the viewpoint of stable conveyance in the stretching step, it is preferable that the film is sequentially sent to the first drying step and the stretching step after the peeling step.

[5.5] First drying step The first drying step is a drying step in which the film is heated to further evaporate the solvent. The drying means is not particularly limited, and for example, hot air, infrared rays, a heating roller, microwaves and the like can be used. From the viewpoint of simplicity, it is preferable to dry with hot air or the like while transporting the film with rollers arranged in a staggered manner. The drying temperature is preferably in the range of 30 to 200 ° C., taking into account the amount of residual solvent and the stretching ratio during transportation.

[5.6] Stretching Step By stretching the film peeled from the metal support, the film thickness, flatness, orientation, etc. of the film can be controlled.

In the method for producing a polyimide film of the present invention, it is preferable to stretch in the longitudinal direction and / or the width direction.

The stretching operation may be performed in multiple stages. Moreover, when performing biaxial stretching, simultaneous biaxial stretching may be performed and you may implement in steps. In this case, stepwise means that, for example, stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any one of the stages. Is also possible.

Thus, for example, the following stretching steps are possible:
-Stretch in the longitudinal direction-> Stretch in the width direction-> Stretch in the longitudinal direction-> Stretch in the longitudinal direction-Stretch in the width direction-> Stretch in the width direction-> Stretch in the longitudinal direction-> Stretch in the longitudinal direction Includes stretching in one direction and contracting the other while relaxing the tension.

The residual solvent amount at the start of stretching is preferably in the range of 2 to 50% by mass.
If the amount of the residual solvent is 2% by mass or more, the film thickness deviation is small and is preferable from the viewpoint of flatness, and if it is within 10% by mass, the surface unevenness is reduced, and the flatness is improved.

In the method for producing a polyimide film of the present invention, the film may be stretched in the longitudinal direction and / or the width direction, preferably in the width direction so that the film thickness after stretching is in a desired range. The film is preferably stretched in a temperature range of (TgL−200) to (TgH + 50) ° C., where TgL is the lowest Tg of the glass transition point (Tg) and TgH is the highest Tg. If it extends in the said temperature range, since a extending | stretching stress can be reduced, a haze will become low. Moreover, generation | occurrence | production of a fracture | rupture is suppressed and the polyimide film excellent in planarity and the coloring property of the film itself is obtained. The stretching temperature is more preferably in the range of (TgL−150) to (TgH + 40) ° C.

In the method for producing a polyimide film according to the present invention, the self-supporting film peeled from the support can be stretched in the longitudinal direction by regulating the running speed with a stretching roller.

In order to stretch the film in the width direction, for example, the entire width of the film is held with clips or pins in the width direction in the entire drying process or a part of the process as disclosed in JP-A-62-46625. A method of drying while drying (referred to as a tenter method), among which a tenter method using a clip is preferably used.

The film stretched in the longitudinal direction or the unstretched film is preferably introduced into the tenter in a state where both ends in the width direction are held by the clip, and stretched in the width direction while running with the tenter clip.

When stretching in the width direction, stretching in the width direction of the film at a stretching speed of 50 to 1000% / min is preferable from the viewpoint of improving the flatness of the film.

If the stretching speed is 50% / min or more, the planarity is improved and the film can be processed at high speed, which is preferable from the viewpoint of production aptitude, and if it is within 1000% / min, the film is broken. Can be processed without any problem.
A more preferable stretching speed is in the range of 100 to 500% / min. The stretching speed is defined by the following formula.

Stretching speed (% / min) = [(d ₁ / d ₂ ) −1] × 100 (%) / t
(In the above formula, d ₁ is the width dimension in the stretching direction of the resin film after stretching, d ₂ is the width dimension in the stretching direction of the resin film before stretching, and t is the time (min) required for stretching. .)

In the stretching step, usually, after stretching, holding and relaxation are performed. That is, in this step, it is preferable to perform a stretching step for stretching the film, a holding step for holding the film in a stretched state, and a relaxation step for relaxing the film in the stretched direction in this order. In the holding step, the drawing at the draw ratio achieved in the drawing step is held at the drawing temperature in the drawing step. In the relaxation stage, the stretching in the stretching stage is held in the holding stage, and then the stretching is relaxed by releasing the tension for stretching. The relaxation step may be performed at a temperature lower than the stretching temperature in the stretching step.

[5.7] Second drying step Next, the stretched film is heated and dried. When the film is heated with hot air or the like, a means for preventing the mixing of used hot air by installing a nozzle that can exhaust used hot air (air containing solvent or wet air) is also preferably used. The hot air temperature is more preferably in the range of 40 to 350 ° C. The drying time is preferably about 5 seconds to 30 minutes, more preferably 10 seconds to 15 minutes.

Further, the heating and drying means is not limited to hot air, and for example, infrared rays, heating rollers, microwaves, etc. can be used. From the viewpoint of simplicity, it is preferable to dry with hot air or the like while transporting the film with rollers arranged in a staggered manner. The drying temperature is more preferably in the range of 40 to 350 ° C. in consideration of the residual solvent amount, the stretching ratio during conveyance, and the like.

In the second drying step, it is preferable to dry the film until the residual solvent amount is 0.5% by mass or less.

[5.8] Winding step The winding step is a step of winding the obtained film and cooling it to room temperature. The winding machine may be a commonly used one, and can be wound by a winding method such as a constant tension method, a constant torque method, a taper tension method, a program tension control method with a constant internal stress, or the like.

The thickness of the film is not particularly limited and is, for example, preferably 1 to 200 μm, particularly 1 to 50 μm.

In the winding process, both ends of the film sandwiched between tenter clips when stretched and conveyed may be slit. The slit film end is preferably cut into a width of 1 to 30 mm, dissolved in a solvent, and reused as a recycled material.

The ratio of the portion of the formed film that is reused as a recycled material is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and still more preferably 30 to 70% by mass.

The input amount varies slightly depending on the amount of return material generated during the film forming process or finally, but the mixing ratio of the returned material to the total solid content in the dope is usually about 10 to 50% by mass, preferably It is about 15 to 40% by mass. The mixing ratio of the recycled materials is preferably as constant as possible for production stability.

Each step from the solvent evaporation step to the winding step described above may be performed in an air atmosphere or an inert gas atmosphere such as nitrogen gas. Moreover, each process, especially a drying process and a extending process, are performed in consideration of the explosion limit concentration of the solvent in the atmosphere.

[5.9] Heating step After the winding step, the film dried in the second drying step is further heat-treated to improve imidization in the polymer chain molecules and between the polymer chain molecules to improve mechanical properties. A heating step is performed.
Moreover, even when the dope is prepared using polyimide (imidation rate 100%) or when the imidation rate of the film becomes 100% by performing the second drying step, the residual stress of the film A heating process is performed for the purpose of relaxing the above.
In addition, the said 2nd drying process may serve as a heating process.

The heating means is performed using a known means such as hot air, an electric heater, or a microwave. As the electric heater, the above-described infrared heater can be used.

As the heat treatment conditions, it is preferable that the final treatment conditions are suitably in the temperature range of 200 to 450 ° C. and in the range of 30 seconds to 1 hour. Thereby, the dimensional stability of a polyimide film can be improved. In the heating step, if the film is heated rapidly, defects such as an increase in surface defects occur, and therefore it is preferable to select the heating method as appropriate. The heating step is preferably performed in a low oxygen atmosphere.

When the heating temperature in the second drying step and the heating step exceeds 450 ° C., the energy required for heating becomes very large, resulting in an increase in manufacturing cost and an increase in environmental load. The following is preferable.

In addition, after the winding process, before or after the heating process, a process of slitting the width direction end of the polyimide film, or a process of neutralizing the polyimide film if charged, etc. It is also good.

[6] Physical Properties of Polyimide Film [6.1] Film Length, Width, Film Thickness The polyimide film of the present invention is preferably long, and specifically has a length of about 100 to 10,000 m. Preferably, it is wound up in a roll shape. The width of the polyimide film of the present invention is preferably 1 m or more, more preferably 1.4 m or more, and particularly preferably 1.4 to 4 m.

The film thickness is preferably in the range of 1 to 200 μm from the viewpoint of strength and transparency as a flexible printed board. When the film thickness is 1 μm or more, a certain level of film strength can be developed. If the film thickness is 200 μm or less, the film substrate is flexible. In particular, the thickness is preferably 1 to 50 μm.

[6.2] Haze The polyimide film of the present invention is a sample having a thickness of 50 μm. The haze is preferably less than 2%, more preferably less than 0.5%, and less than 0.3%. More preferably. By setting the haze to less than 1%, there is an advantage that the range of application to various devices is widened as a film for optical applications.

Haze is measured using a haze meter (NDH2000 type, manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS K-7136, one sample that has been conditioned for 24 hours in an air-conditioned room at 23 ° C. and 55% RH.

《Flexible printed circuit board》
The flexible printed circuit board of the present invention can be obtained by using the polyimide film of the present invention as a base film and pressing a metal foil on the base film via an adhesive. Examples of the adhesive used here include acrylic, polyimide, and epoxy adhesives.
The metal foil that is thermocompression bonded to the polyimide film via an adhesive is preferably a copper foil from the viewpoint of cost reduction, but other metal foils such as aluminum, gold, silver, nickel, and tin may be used.

《LED lighting substrate》
The substrate for LED illumination of the present invention is not particularly limited as long as it uses the polyimide film of the present invention, and examples thereof include a double-sided substrate and a composite substrate with an aluminum plate. In the case where heat dissipation is required as the brightness of the LED increases, it is possible to improve the heat dissipation by combining with an aluminum plate.

《Front plate for flexible display》
The front plate for a flexible display of the present invention is not particularly limited as long as it uses the polyimide film of the present invention. As a flexible display on which the front plate for flexible display of the present invention is mounted, for example, an organic EL element in which an organic functional layer such as a light emitting layer is laminated on a substrate, a gas barrier film, a film color filter, one side or both sides A polarizing plate including a polarizing plate protective film, a film-type touch sensor, and the like are laminated in this order. The front panel for a flexible display of the present invention is laminated on a film type touch sensor of a flexible display configured as described above, for example.

In addition, the polyimide film of this invention may be used for the board | substrate of the organic EL element which comprises the said flexible display, and may be used for the polarizing plate protective film of the polarizing plate which comprises the said flexible display.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

[Example 1]
<< Preparation of polyimide film 101 >>
<Preparation of polyimide A>
In a 500 mL separable four-necked flask equipped with a stainless steel vertical agitator, nitrogen inlet tube, Dean-Stark apparatus, 56.11 g (0.18 mol) of 4,4′-oxydiphthalic anhydride (ODPA), diethyl Toluenediamine (DETDA) 32.09 g (0.18 mol), γ-butyrolactone (GBL) 326.87 g, pyridine 2.85 g, and toluene 33 g were charged, and the inside of the reaction system was purged with nitrogen. ODPA was dissolved by stirring at 80 ° C. for 30 minutes under a nitrogen stream, and then heated to 180 ° C. and stirred for 6 hours.

The water produced during the reaction was removed from the reaction system as an azeotrope with toluene and pyridine. After completion of the reaction, the reaction solution was cooled to room temperature to obtain a 20% by mass polyimide solution. The structure of the obtained polyimide is as shown in the following formula. Isopropanol was added to the polyimide solution, and the mixture was cooled after stirring to obtain a polyimide solid. This solid was washed and dried to obtain polyimide A.

In the above formula, R ¹ to R ³ represent a methyl group or an ethyl group, ^one of R ¹ to R ³ represents a methyl group, and two represents an ethyl group.

<Preparation of dope>
A main dope having the following composition was prepared. First, dichloromethane (boiling point 40 ° C.) was added to the pressure dissolution tank. The prepared polyimide A and the remaining components were charged into a pressure dissolution tank containing a solvent while stirring. While this was heated and stirred, it was completely dissolved, and this was dissolved in Azumi Filter Paper No. The main dope was prepared by filtration using 244.

<Composition of main dope>
Dichloromethane 350 parts by mass Polyimide A 100 parts by mass Hydrogen bonding compound 1 represented by the following formula 10 parts by mass Matting agent (Aerosil R812, manufactured by Nippon Aerosil Co., Ltd.) 0.5 parts by mass

<Casting process>
Next, using an endless belt casting apparatus, the dope was cast uniformly on a stainless steel belt support at a temperature of 30 ° C. and a width of 1500 mm. The temperature of the stainless steel belt was controlled at 30 ° C.

<Peeling process>
On the stainless steel belt support, the solvent was evaporated until the residual solvent amount in the cast (cast) film was 75%, and then peeled off from the stainless steel belt support with a peeling tension of 180 N / m.

<Extension process>
The peeled polyimide film was stretched 1.50 times in the width direction using a clip-type tenter while applying heat at 200 ° C. The residual solvent amount at the start of stretching was 20% by mass.

<Drying process>
The stretched film was dried at a drying temperature at which the residual solvent amount was less than 0.1% by mass with a transport tension of 100 N / m and a drying time of 15 minutes, to obtain a film having a dry film thickness of 55 μm. The obtained film was wound up to obtain a polyimide film 101.

<< Preparation of polyimide film 102 >>
In the production of the polyimide film 101, a polyimide film 102 was produced in the same manner except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 2 represented by the following formula.

<< Preparation of polyimide film 103 >>
In the production of the polyimide film 101, a polyimide film 103 was produced in the same manner except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 3 represented by the following formula.

<< Preparation of polyimide film 104 >>
In the production of the polyimide film 101, a polyimide film 104 was produced in the same manner except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 4 (Tinuvin 171) represented by the following formula.

<< Preparation of polyimide film 105 >>
In the production of the polyimide film 101, a polyimide film 105 was produced in the same manner except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 5 (Tinuvin 928) represented by the following formula.

<< Preparation of polyimide film 106 >>
In the production of the polyimide film 101, a polyimide film 106 was produced in the same manner except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 6 represented by the following formula.

<< Preparation of polyimide film 107 >>
In the production of the polyimide film 101, a polyimide film 107 was produced in the same manner except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 7 represented by the following formula.

<< Preparation of polyimide film 108 >>
A polyimide film 108 was produced in the same manner as in the production of the polyimide film 101 except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 8 represented by the following formula.

In the above formula, R in one of the three CH ₂ OR groups represents a hydrogen atom, and R in the other one represents an acetyl group. All five other Rs represent benzozoyl groups.

<< Preparation of polyimide film 109 >>
A polyimide film 109 was produced in the same manner as in the production of the polyimide film 101 except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 9 (Pine Crystal KE-604, manufactured by Arakawa Chemical Industries, Ltd.).

<< Preparation of polyimide film 110 >>
In the production of the polyimide film 101, a polyimide film 110 was produced in the same manner except that the hydrogen bonding compound 1 was changed to the hydrogen bonding compound 10 represented by the following formula.

In the above formula, R in one of the three CH ₂ OR groups represents a hydrogen atom. The other seven Rs all represent a benzoyl group.

<< Preparation of polyimide film 111 >>
In the production of the polyimide film 106, a polyimide film 111 was produced in the same manner except that the polyimide A was changed to the polyimide B. The preparation method of polyimide B is shown below.

<Preparation of polyimide B>
In the same apparatus as that used for the preparation of polyimide A, 46.80 g (0.15 mol) of ODPA and 38.16 g (0.15 of 4,4′-diamino-3,3 ′, 5,5′-tetramethyldiphenylmethane) were used. Mol), 147.67 g of GBL, 2.39 g of pyridine, and 50 g of toluene, and the inside of the reaction system was purged with nitrogen. ODPA was dissolved by stirring for 30 minutes at 80 ° C. under a nitrogen stream, and then heated to 180 ° C. and stirred for 7 hours.

The water produced during the reaction was removed from the reaction system as an azeotrope with toluene and pyridine. After completion of the reaction, when cooled to 120 ° C., 100 g of GBL was added to obtain a polyimide solution having a concentration of 25% by mass. The structure of the obtained polyimide is as shown in the following formula. Isopropanol was added to the polyimide solution, and the mixture was cooled after stirring to obtain a polyimide solid. This solid was washed and dried to obtain polyimide B.

<< Preparation of polyimide film 112 >>
In the production of the polyimide film 106, a polyimide film 112 was produced in the same manner except that the polyimide A was changed to the polyimide C.
Polyimide C uses 0.18 mol of 2,2-bis [4- (4-aminophenoxy) phenyl] propane instead of 0.18 mol of diethyltoluenediamine (DETDA) in the preparation of polyimide A. Can be prepared.

<< Preparation of polyimide film 113 >>
In the production of the polyimide film 106, a polyimide film 113 was produced in the same manner except that the polyimide A was changed to the polyimide D.
Polyimide D is prepared by using 0.18 mol of 4,4′-bis (4-aminophenoxy) biphenyl instead of 0.18 mol of diethyltoluenediamine (DETDA) in the preparation of polyimide A. be able to.

<< Preparation of polyimide film 114 >>
In the production of the polyimide film 106, a polyimide film 114 was produced in the same manner except that the polyimide A was changed to the polyimide E.
Polyimide E was prepared by using 0.18 mol α, α′-bis (4-aminophenyl) -1,4-diisopropylbenzene instead of 0.18 mol diethyltoluenediamine (DETDA) in the preparation of polyimide A. Can be prepared.

<< Preparation of polyimide film 115 >>
In the production of the polyimide film 106, a polyimide film 115 was produced in the same manner except that the polyimide A was changed to the polyimide F.
Polyimide F should be prepared by using 0.18 mol of 2,2'-bis (trifluoromethyl) benzidine instead of 0.18 mol of diethyltoluenediamine (DETDA) in the preparation of polyimide A. Can do.

<< Preparation of polyimide film 116 >>
In the production of the polyimide film 106, a polyimide film 116 was produced in the same manner except that the polyimide A was changed to the polyimide G.
Polyimide G can be prepared by using 0.18 mol of 4,4′-diaminodicyclohexylmethane in place of 0.18 mol of diethyltoluenediamine (DETDA) in the preparation of polyimide A.

<< Preparation of polyimide film 117 >>
In the production of the polyimide film 101, a polyimide film 117 was produced in the same manner except that the hydrogen bonding compound 1 was not added when the dope was prepared.

<< Preparation of polyimide film 118 >>
In the production of the polyimide film 112, a polyimide film 118 was produced in the same manner except that the hydrogen bonding compound 6 was not added when the dope was prepared.

<< Preparation of polyimide film 119 >>
In the production of the polyimide film 101, a polyimide film 119 was produced in the same manner except that 10 parts by mass of the hydrogen bonding compound 1 was changed to 10 parts by mass of water.

<< Preparation of polyimide film 120 >>
In the production of the polyimide film 101, a polyimide film 120 was produced in the same manner except that 10 parts by mass of the hydrogen bonding compound 1 was changed to 10 parts by mass of benzene.

<< Evaluation of polyimide films 101-120 >>
An organic EL device was produced using the polyimide films 101 to 120 produced as described above and evaluated.

Using the polyimide films 101 to 120 as a transparent substrate, a reflective electrode made of chromium thereon, a metal electrode using ITO (tin-doped indium oxide) as a metal electrode (anode) on the reflective electrode, and an organic light emitting layer As a hole transport layer, poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT: PSS) is formed with a thickness of 80 nm on the anode by a sputtering method, and then a shadow mask is formed on the hole transport layer. In this way, RGB light emitting layers R, G, and B were formed with a layer thickness of 100 nm. As the red light emitting layer R, tris (8-hydroxyquinolinate) aluminum (Alq ₃ ) and a light emitting compound [4- (dicyanomethylene) -2-methyl-6 (p-dimethylaminostyryl) -4H-pyran] ( DCM) were co-evaporated (mass ratio 99: 1) to form a thickness of 100 nm. As the green light emitting layer G, Alq ₃ as a host and a light emitting compound coumarin 6 (3- (2-benzothiazolyl) -7- (diethylamino) coumarin) are co-evaporated (mass ratio 99: 1) to a thickness of 100 nm. Formed. The blue light-emitting layer B was formed with a thickness of 100 nm by co-evaporating BAlq and a light-emitting compound Perylene as a host (mass ratio 90:10).

Further, calcium is deposited to a thickness of 4 nm by vacuum deposition as a first cathode having a low work function so that electrons can be efficiently injected onto the organic light emitting layer, and a second cathode is formed on the first cathode. As a result, aluminum was formed to a thickness of 2 nm. Here, the aluminum used as the second cathode has a role of preventing the calcium as the first cathode from causing chemical alteration when a transparent conductive film is formed thereon by a sputtering method. Next, a transparent conductive film having a thickness of 80 nm was formed on the cathode by sputtering to form a transparent electrode. Here, ITO was used as the transparent conductive film. Furthermore, 200 nm of silicon nitride was deposited on the transparent electrode by a CVD method to form an organic EL element unit as an insulating layer.

Next, a polyethylene terephthalate film with a gas barrier layer having a thickness of 20 μm was used as the gas barrier film, and a thermosetting liquid adhesive (epoxy resin) was applied to a thickness of 25 μm on one side of the gas barrier film. A sealing unit was produced.

Next, the organic EL element unit formed from the transparent substrate to the insulating layer and the sealing unit were laminated under a reduced pressure of 0.1 MPa at 90 ° C., and the pressure was applied and held for 5 minutes. Subsequently, the laminate was returned to the atmospheric pressure environment, and further heated at 90 ° C. for 30 minutes to cure the adhesive, thereby producing an organic EL display device.

The produced organic EL display device was held at 80 ° C / 45% RH for 10 minutes using a heat shock tester (Hitachi Appliances Co., Ltd., EC-35EXH) and then changed to 25 ° C / 80% RH. This was held for 10 minutes, and the operation of changing the temperature again to 80 ° C. and 45% RH was taken as one cycle, and a durability test was repeated for 150 cycles. The organic EL display device after the endurance test was placed on a flat glass, its warpage was measured using a ruler, and evaluated according to the following criteria.
◎: Warpage of 2 mm or less occurred ○: Warpage of 5 to 10 mm occurred ×: Warpage of 10 mm or more occurred

As shown in Table 1, since the warpage of the organic EL display device produced using the polyimide film of the present invention is suppressed, the dimensional variation due to the temperature and humidity environment variation of the polyimide film of the present invention is suppressed. It can be said that.
On the other hand, the polyimide film of the comparative example does not contain a hydrogen bonding compound, and the warp of the organic EL display device is not suppressed. For this reason, the polyimide film of the comparative example is considered to have undergone dimensional variations in a high temperature and high humidity environment.

[Example 2]
Using the polyimide films 101 to 120 produced in Example 1, a flexible printed board was produced as follows.

On one side of the polyimide film, a 20 mass% chromium-nickel alloy layer having an average thickness of 230 mm as a metal thin film is formed by a direct current sputtering method using a sputtering facility composed of an unwinder, a sputtering device, a winder, and the like. Formed. Further, similarly, a copper thin film having an average thickness of 1000 mm was formed on the metal thin film.

Next, a 9 μm-thick copper layer was provided on the copper thin film by electrolytic copper plating to obtain a metal-coated polyimide film. The copper plating bath used was a copper sulfate plating bath with a copper concentration of 23 g / L, and the bath temperature during plating was 27 ° C. In addition, the plating tank is a multi-structure tank in which a plurality of plating tanks are connected, and is transported so that a polyimide film having a metal layer on one side is continuously immersed in each tank by an unwinder and a winder. Then, electroplating was performed. The conveying speed was 75 m / h, and the copper plating was performed by adjusting the average cathode current density of the plating tank to 1.0 to 2.5 A / dm ² .

Next, using this metal-coated polyimide film, a COF (Chipon film) having a wiring interval of 30 μm and a total wiring width of 15000 μm was prepared by a subtractive method. An IC chip was mounted on this, and the electrodes on the surface of the IC chip and the lead portions of the wiring were subjected to wire bonding at 400 ° C. for 0.5 seconds using a wire bonding apparatus. At this time, the proportion of the bonding failure between the lead and the polyimide film generated in the inner lead portion was 0.0001%. In this way, a flexible printed circuit board was produced.

The flexible printed circuit board produced above was placed in a constant temperature and humidity chamber (PL-4 manufactured by ESPEC) set at 60 ° C.

In a constant temperature and humidity chamber set at 60 ° C, a MIT tester performs a bending test under conditions of a load of 500 g, a refraction angle of 135 °, a refraction cycle of 175 cpm, and a refractive part locality radius of 0.38 mm, and the energized state is cut off due to circuit breakage. The number of times until was measured. The flexible printed circuit board using the polyimide film of the present invention was confirmed to be an excellent flexible printed circuit board with no occurrence of interruption of the energized state even after the number of foldings of 5000 times or more and small curling after the bending test. .

In addition, the flexible printed circuit board using the polyimide film as a comparative example was curled during the bending test, and the energized state was also interrupted in the middle.

[Example 3]
With reference to the LED illumination production method described in Japanese Patent Application Laid-Open No. 2014-22508, LED illumination was produced using each flexible printed circuit board produced in Example 2.

Each of the LED illuminations produced above was allowed to emit light at room temperature (about 25 ° C.) under a constant current condition of ^2.5 mA / cm ² , and the luminance of the front emission immediately after the start of emission (cd / m ² ) was determined as the spectral radiance. When measured using a total of C154S-2000 (manufactured by Konica Minolta Co., Ltd.), all of the LED lights mounted with the polyimide film of the present invention had a front luminance of 1000 (cd / m ² ) or more.

From the above, it was confirmed that the polyimide film having the structure of the present invention has high transparency, and the LED lighting device on which the polyimide film is mounted has excellent front luminance.

[Example 4]
An organic EL display device was produced using the polyimide film produced in Example 1 and evaluated.

(1) Production of polyimide film with hard coat layer A polyimide film with a hard coat layer was produced by providing the following hard coat layer on one side of the polyimide films 101 to 120 produced in Example 1.

(Formation of hard coat layer)
The following hard coat layer composition was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for forming a hard coat layer, which was applied onto a polyimide film by a die coater and dried at 70 ° C. Next, while purging with nitrogen so that the oxygen concentration in the treatment space is 1.0 volume% or less, the coating is applied using an ultraviolet lamp under the conditions of an illuminance of 300 mW / cm ² and an irradiation amount of 0.3 J / cm ^2. The layer was cured. Furthermore, in the heat treatment zone, heat treatment was carried out at 130 ° C. for 5 minutes with a conveyance force of 300 N / m to form a hard coat layer having a dry layer thickness of 7 μm.

(Hard coat layer composition)
The following materials were stirred and mixed to obtain a hard coat layer composition.
Pentaerythritol triacrylate 20.0 parts by mass Pentaerythritol tetraacrylate 50.0 parts by mass Dipentaerythritol hexaacrylate 30.0 parts by mass Dipentaerythritol pentaacrylate 30.0 parts by mass Irgacure 184 (manufactured by BASF Japan Ltd.) 0 part by mass Fluoro-siloxane graft polymer I (35% by mass) 5.0 parts by mass Seahoster KEP-50 (powder silica particles, average particle size 0.47 to 0.61 μm, manufactured by Nippon Shokubai Co., Ltd.) 3 parts by mass Propylene glycol monomethyl ether 20 parts by mass Methyl acetate 40 parts by mass Methyl ethyl ketone 60 parts by mass

(Preparation of fluorine-siloxane graft polymer I)
Hereinafter, commercial names of materials used for the preparation of the fluorine-siloxane graft polymer I are shown.
Radical polymerizable fluororesin (FA): Cefal coat CF-803 (hydroxy (hydroxyl group) value 60, number average molecular weight 15000; manufactured by Central Glass Co., Ltd.)
One-end radically polymerizable polysiloxane (B): Silaplane FM-0721 (number average molecular weight 5000; manufactured by JNC Corporation)
Radical polymerization initiator: Perbutyl O (t-butylperoxy-2-ethylhexanoate; manufactured by NOF Corporation)
Curing agent: Sumidur N3200 (biuret type prepolymer of hexamethylene diisocyanate; manufactured by Sumika Bayer Urethane Co., Ltd.)

First, a radical polymerizable fluororesin (FA) was prepared as follows.
A glass reactor equipped with a mechanical stirrer, a thermometer, a condenser and a dry nitrogen gas inlet was added to cefal coat CF-803 (1554 parts by mass), xylene (233 parts by mass), and 2-isocyanatoethyl methacrylate (6 3 parts by mass) and heated to 80 ° C. in a dry nitrogen atmosphere. After reacting at 80 ° C. for 2 hours and confirming that the absorption of isocyanate disappeared by the infrared absorption spectrum of the sample, the reaction mixture was taken out and 50% by mass of radically polymerizable fluororesin (FA) via a urethane bond. Got.

Next, the above synthesized radical polymerizable fluororesin (FA) (26.1 parts by mass), xylene (19.5 parts) were added to a glass reactor equipped with a mechanical stirrer, a thermometer, a condenser and a dry nitrogen gas inlet. Parts by weight), n-butyl acetate (16.3 parts by weight), methyl methacrylate (2.4 parts by weight), n-butyl methacrylate (1.8 parts by weight), lauryl methacrylate (1.8 parts by weight), 2- Hydroxyethyl methacrylate (1.8 parts by mass), FM-0721 (5.2 parts by mass), and perbutyl O (0.1 parts by mass) were added and heated to 90 ° C. in a nitrogen atmosphere. Held for hours. Perbutyl O (0.1 part) was added, and the mixture was further maintained at 90 ° C. for 5 hours to obtain a 35 mass% fluorine-siloxane graft polymer I solution having a weight average molecular weight of 171,000.

(2) Production of Circular Polarizing Plate A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizer.

Next, a λ / 4 retardation film was produced by the method described in paragraphs 0277 to 0287 of JP2013-101229A.

Then, according to the following steps 1 to 5, a polarizer, a λ / 4 retardation film, and a protective film (Konica Minolta Tack KC4UY (manufactured by Konica Minolta Co., Ltd.)) are bonded together in a roll-to-roll method, and a circularly polarizing plate is attached. Produced. In addition, it bonded together so that a protective film might be arrange | positioned at the back surface side (viewing side) of a polarizer.

Step 1: The λ / 4 retardation film and the stretched protective film were immersed in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, washed with water, dried, and bonded to the polarizer. The surface was saponified.

Step 2: The prepared polarizer was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.

Step 3: Excess adhesive adhered to the polarizer in Step 2 was gently wiped, and this was placed on the λ / 4 retardation film processed in Step 1.

Step 4: The λ / 4 retardation film and polarizer laminated in Step 3 were bonded to the protective film at a pressure of 20 to 30 N / cm ² and a conveying speed of about 2 m / min.

Step 5: A sample obtained by bonding the polarizer, the λ / 4 retardation film, and the protective film prepared in Step 4 in a dryer at 80 ° C. was dried for 2 minutes to prepare a circularly polarizing plate.

(3) Production of organic EL display device Using the polyimide films 101 to 120 produced in Example 1 as a transparent substrate, a reflective electrode made of chromium is formed thereon, and ITO (tin-doped indium oxide) is further formed on the reflective electrode. An anode consisting of

A hole transport layer having a thickness of 80 nm was formed on the anode by sputtering using poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT: PSS). Next, a red light emitting layer R, a green light emitting layer G, and a blue light emitting layer B each having a thickness of 100 nm were formed on the hole transport layer using a shadow mask. The red light emitting layer R includes tris (8-hydroxyquinolinate) aluminum (Alq ₃ ) as a host and 4- (dicyanomethylene) -2-methyl-6 (p-dimethylaminostyryl) -4H-pyran (DCM) as a luminescent compound. ) And co-evaporated (mass ratio 99: 1). The green light-emitting layer G was formed by co-evaporation (mass ratio 99: 1) of Alq ₃ as a host and coumarin 6 (3- (2-benzothiazolyl) -7- (diethylamino) coumarin) as a light-emitting compound. The blue light emitting layer B was formed by co-evaporation (mass ratio 90:10) of BAlq as a host and Perylene as a light emitting compound. In this way, an organic light emitting layer composed of a hole transport layer, a red light emitting layer R, a green light emitting layer G, and a blue light emitting layer B was formed.

Further, a first cathode was formed on the organic light-emitting layer by depositing calcium with a thickness of 4 nm by vacuum deposition. Next, a second cathode was formed by depositing aluminum with a thickness of 2 nm on the first cathode. The aluminum used for the second cathode has a role to prevent the calcium as the first cathode from being chemically altered when the transparent conductive film formed thereon is formed by sputtering.

Next, on the first and second cathodes, ITO was formed to a thickness of 80 nm by sputtering to form a transparent electrode. Further, an insulating film was formed by depositing silicon nitride with a thickness of 200 nm on the transparent electrode by a CVD method. In this way, an organic EL element was produced.

Next, a thermosetting liquid adhesive (epoxy resin) was applied at a thickness of 25 μm to one surface of a 20 μm thick polyethylene terephthalate film with a gas barrier layer to produce a sealing unit.

Next, the organic EL element formed from the transparent substrate to the insulating film and the sealing unit were stacked and pressed under reduced pressure conditions of 0.1 MPa at 90 ° C. and held for 5 minutes. Subsequently, the laminate was heated at 90 ° C. for 30 minutes in an atmospheric pressure environment to cure the adhesive, and an organic EL display device was produced.

The light emitting area of the produced organic EL display device was 1296 mm × 784 mm. Further, the front luminance when a DC voltage of 6 V was applied to the organic EL display device was 1200 cd / m ² . The front luminance is measured using a spectral radiance meter CS-1000 manufactured by Konica Minolta Co., Ltd. so that the front luminance is 2 degrees and the optical axis of the spectral radiance meter matches the normal from the light emitting surface. The visible light wavelength range of 430 to 480 nm was measured, and the integrated intensity was taken.

(4) Production of organic EL display device The produced circularly polarizing plate is laminated on the produced organic EL display device, and the hard coat layer is the outermost polyimide film with a hard coat layer as a front plate. It laminated | stacked through the contact bonding layer so that it might become a surface layer, and produced the organic electroluminescence display.

(5) Evaluation of organic EL display device The prepared organic EL display device was held at 80 ° C. and 45% RH for 10 minutes using a heat shock tester (manufactured by Hitachi Appliances, Inc., EC-35EXH). The durability test was repeated 150 cycles with the operation of changing to 80 ° C./80% RH, holding for 10 minutes, and again changing to 80 ° C./45% RH as one cycle. The organic EL display device after the durability test was placed on a flat glass, and its warpage was measured using a ruler. As a result, the organic EL display device using the polyimide film of the present invention was excellent in flatness without warping, but the organic EL display device of the comparative example was warped and distorted.

As described above, the present invention is suitable for providing a polyimide film in which dimensional fluctuation due to temperature and humidity environment fluctuation is suppressed, a flexible printed circuit board including the polyimide film, a substrate for LED illumination, and a front panel for flexible display. .

Claims

In a polyimide film containing a polyimide having a diphenyl ether structure derived from 4,4′-oxydiphthalic anhydride,
A polyimide film comprising a hydrogen bonding compound having an aromatic ring and a hydrogen bond donor site in the molecule.
2. The polyimide film according to claim 1, wherein a value obtained by dividing the number of the aromatic rings by the number of the hydrogen bond donor sites is in the range of 1 to 5.
A flexible printed circuit board comprising the polyimide film according to claim 1.
An LED illumination substrate comprising the polyimide film according to claim 1.
A front panel for flexible display comprising the polyimide film according to claim 1.