TW202405056A - Copolymer polyimide - Google Patents

Abstract

A copolymer polyimide containing a structural unit A derived from a tetracarboxylic dianhydride represented by formula (1) and a structural unit B derived from a diamine represented by general formula (2) shown below, in which at least one of the structural unit A and the structural unit B includes two or more types of structural unit, wherein the Hamaker constant (A131), represented by formula (3) and corresponding with the self-interaction of the copolymer polyimide, is less than 6.65*10-21 J with respect to [gamma]-butyrolactone, and more than 5.80*10-21 J with respect to methyl isobutyl ketone. (R1 and R2 represent organic groups excluding monocyclic aromatic groups and condensed polycyclic aromatic groups).

Description

Copolymerized polyimide

This invention relates to copolymerized polyimides, varnishes and polyimide films.

In recent years, with the advent of a highly information-based society, optical materials that have both heat resistance and colorless transparency are required in the fields of optical communications such as optical fibers and optical waveguides, and in the fields of display devices such as liquid crystal alignment films and color filters. Especially in the field of display devices, research is underway to replace glass substrates with plastic substrates that are lightweight and highly flexible, and displays that can be bent or rolled are being developed. Therefore, the development of polyimide resin as a high-performance optical material that can be used in such applications is already underway.

For example, Patent Document 1 discloses that in order to improve flexibility, heat resistance, transparency, and dimensional stability, cyclohexanetetracarboxylic dianhydride is reacted with a diamine containing a phenylene group and an isopropylidene group. of polyimide resin. Furthermore, Patent Document 2 discloses that in order to obtain a polyimide film that has heat resistance, transparency, strength, and high resistance to methyl ethyl ketone, a polyimide film containing a moiety derived from a biphenyltetracarboxylic acid-based compound and an aromatic film having an ether group is obtained. A polyimide film composed of a polyimide resin composed of a moiety of a tetracarboxylic acid-based compound and a moiety of an aromatic diamine having a fluorine group and a moiety of an aromatic diamine having a styrene group. Patent Document 3 discloses that in order to obtain a colorless and transparent film that does not change its shape in polar solvents, it is characterized by a polyimide film with a solvent resistance index within 2% and a yellowness of 10 or less. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2006-199945 [Patent Document 2] International Publication No. 2017/073782 [Patent Document 3] Japanese Patent Application Publication No. 2011-074384

[Problem to be solved by the invention]

The polyimide disclosed in Patent Document 1 exhibits solubility in various organic solvents by relaxing its rigid structure, but there are ketone solvents used for wet processing that is indispensable especially for manufacturing flexible displays. The problem of low patience. On the other hand, the polyimide disclosed in Patent Documents 2 and 3 is insoluble in various organic solvents, and the polyimide resin cannot be dissolved in the solvent and used as a varnish. Polyimide varnish does not undergo imidization reaction when forming a film, so high temperature is not required and quality control is easy. Therefore, there is a demand for a polyimide resin that is soluble in the solvent used in the varnish and has resistance to the solvent used in the wet process. The present invention was made in view of such a situation, and an object of the present invention is to provide a copolymerized polymer that has resistance to general-purpose organic solvents and has excellent chemical resistance, but is soluble in a specific solvent and can therefore be used as a varnish. Imide, varnish and polyimide film containing the polyimide. [Means to solve the problem]

The inventors of the present invention discovered that a copolymerized polyimide with a specific structure and a predetermined value of the Hamaker constant corresponding to the self-interaction with a specific solvent can solve the above problems, and even completed the invention.

That is, the present invention relates to the following [1] to [11]. [1] A copolymerized polyimide containing: a structural unit A derived from a tetracarboxylic dianhydride represented by the following formula (1), and a structural unit B derived from a diamine represented by the following formula (2), and the structural unit At least one of A and structural unit B is two or more structural units; The following formula (3) represents the Hamaker constant (A ₁₃₁ ) corresponding to the self-interaction of the aforementioned copolymerized polyimide relative to γ -Butyrolactone, less than 6.65×10 ^-21 J, and relative to methyl isobutyl ketone, greater than 5.80×10 ^-21 J. [Chemical 1] R ¹ is a 4-valent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups, and R ² is a divalent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups. [Number 1] Here, [Number 2] K _B : Boltzmann constant, T: absolute temperature (298.15K), h: Planck constant, n ₁ : refractive index of the above-mentioned copolymerized polyimide at 25°C, n ₃ : The refractive index of γ-butyrolactone or methyl isobutyl ketone at 25°C, ε ₁ : The dielectric constant of the aforementioned copolymerized polyimide at 25°C, ε ₃ : γ-butyrolactone at 25°C Dielectric constant of lactone or methyl isobutyl ketone, ν _e1 : main electron absorption vibration number of the aforementioned copolymerized polyimide (sec ^-1 ), ν _e3 : γ-butyrolactone or methyl isobutyl ketone Main electron absorption vibration number of ketone (sec ^-1 ) [2] The copolymerized polyimide as described in the aforementioned [1], wherein the aforementioned formula (3) represents the self-interaction of the aforementioned copolymerized polyimide The corresponding Hamaker constant (A ₁₃₁ ) is less than 6.26×10 ^-21 J for γ-butyrolactone, and larger than 6.20×10 ^-21 J for methyl isobutyl ketone. [3] The copolymerized polyimide as described in the above [1] or [2], wherein the structural unit A is two or more kinds of structural units, and the structural unit B is two or more kinds of structural units. [4] The copolymerized polyimide as described in the above [3], wherein the structural unit A contains a structural unit selected from the group consisting of alicyclic tetracarboxylic dianhydride and a fluorine-containing aromatic tetracarboxylic dianhydride. The structural unit A1 of at least one of the structural units, and the structural unit A2 derived from aromatic tetracarboxylic dianhydride that does not contain fluorine, and the structural unit B contains a structural unit selected from alicyclic diamines, derived from fluorine-containing A structural unit B1 derived from at least one of a structural unit of an aromatic diamine and a structural unit derived from a polysiloxane diamine, and a structural unit B2 derived from a fluorine-free aromatic diamine. [5] The copolymerized polyimide as described in [4] above, wherein the structural unit A2 is selected from the group consisting of two phthalic anhydrides with a single bond, -O-, -CO-, -NHCO-, - The structural units of tetracarboxylic dianhydride linked by S-, -SO ₂ -, -COO- or -CR ₂ - and derived from two trimellitic anhydrides and glycol, hydroquinone, or bisphenols At least one of the structural units of tetracarboxylic dianhydride linked by an ester bond, and the aforementioned R is independently H or CH ₃ , or R ₂ is selected from cyclopentylene, cyclohexylene or 9-fluoride In at least one of the bases, the content of the constituent unit A2 relative to the total amount of the constituent unit A is 5 to 40 mol%. [6] The copolymerized polyimide as described in the above [4] or [5], wherein the component derived from fluorine-containing aromatic tetracarboxylic dianhydride in the structural unit A and the component derived from the fluorine-containing aromatic tetracarboxylic dianhydride in the structural unit B The total amount of the constituent components of the fluorine-containing aromatic diamine is 10 to 60 mol% relative to the total amount of the constituent units. [7] A method for producing a copolymerized polyimide is a method for producing a copolymerized polyimide as described in any one of the aforementioned [1] to [6]. The method is to make a diamine and a tetracarboxylic acid diamine. The anhydride is polymerized in the presence of an aprotic solvent with a refractive index of 1.42 or higher at 25°C. [8] A varnish containing: the copolymerized polyimide as described in any one of [1] to [6] above, and an aprotic solvent with a refractive index of 1.42 or more at 25°C. [9] The varnish according to the above [8], wherein the aprotic solvent has a refractive index of 1.42 or more at 25° C. and contains γ-butyrolactone. [10] A polyimide film composed of the copolymerized polyimide as described in any one of the aforementioned [1] to [6]. [11] A method for manufacturing a polyimide film is to apply the varnish as described in [8] or [9] above on a support and remove the aprotic solvent. [Effects of the invention]

According to the present invention, it is possible to provide a copolymerized polyimide that has resistance to general-purpose organic solvents and has excellent chemical resistance, but is soluble in a specific solvent and can be used as a varnish, and that contains the polyimide. Imine varnish and polyimide film.

[Copolymerized Polyimide] The copolymerized polyimide of the present invention contains: a structural unit A derived from a tetracarboxylic dianhydride represented by the following formula (1), and a structure derived from a diamine represented by the following formula (2) Unit B, and at least one of structural unit A and structural unit B is two or more structural units; The following formula (3) represents the Hamaker constant corresponding to the self-interaction of the aforementioned copolymerized polyimide ( A ₁₃₁ ) is less than 6.65 × 10 ^-21 J relative to γ-butyrolactone and greater than 5.80 × 10 ^-21 J relative to methyl isobutyl ketone. [Chemicalization 2] R ¹ is a 4-valent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups, and R ² is a divalent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups. [Number 3] Here, [Number 4] K _B : Boltzmann constant, T: absolute temperature (298.15K), h: Planck's constant, n ₁ : refractive index of the aforementioned copolymerized polyimide at 25°C, n ₃ : γ at 25°C -Refractive index of butyrolactone or methyl isobutyl ketone, ε ₁ : dielectric constant of the aforementioned copolymerized polyimide at 25°C, ε ₃ : γ-butyrolactone or methyl isobutyl ketone at 25°C Dielectric constant of butyl ketone, ν _e1 : the main electron absorption vibration number of the aforementioned copolymerized polyimide (sec ^-1 ), ν _e3 : the main electron absorption vibration of γ-butyrolactone or methyl isobutyl ketone Number (second ^-1 )

＜Each structural unit of copolymerized polyimide＞ The copolymerized polyimide of the present invention contains: a structural unit A derived from the tetracarboxylic dianhydride represented by the aforementioned general formula (1), and a structural unit B derived from the diamine represented by the aforementioned general formula (2), and the structural unit At least one of A and structural unit B is two or more kinds of structural units. Each structural unit is explained below.

(Structural unit A) Structural unit A is a structural unit derived from tetracarboxylic dianhydride represented by the following formula (1). [Chemical 3] R ¹ is a tetravalent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups. In formula (1), R ¹ is a 4-valent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups, and is preferably obtained by removing 4 carboxyl groups (2 acid anhydride groups) from the tetracarboxylic dianhydride described below. The one who succeeds.

The structural unit A is not limited as long as it is a structural unit derived from the tetracarboxylic dianhydride represented by formula (1). The structural unit A is preferably a tetracarboxylic acid derived from at least one selected from the group consisting of alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride containing a fluorine group, and fluorine-free aromatic tetracarboxylic dianhydride. The structural unit of the dianhydride contains at least one structural unit A1 selected from a structural unit derived from an alicyclic tetracarboxylic dianhydride and a structural unit derived from a fluorine-containing aromatic tetracarboxylic dianhydride, and a structural unit A1 derived from a fluorine-free tetracarboxylic dianhydride. The structural unit A2 of aromatic tetracarboxylic dianhydride is more preferred. In addition, the structural unit A1 does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain, and the structural unit A2 does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain.

Examples of alicyclic tetracarboxylic dianhydrides that provide structural unit A1 include: cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA), cyclohexane-1,2,3,4-tetracarboxylic acid Dianhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic anhydride (CpODA), 1,2 ,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclohexane Pentanetetracarboxylic dianhydride, 1,2,4,5-cyclopentanetetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic dianhydride, 2,2-propylene-4, 4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2.2.2]octane -7-ene-2,3,5,6-tetracarboxylic dianhydride, and bicyclo[4.4.0]decane-2,3,6,7-tetracarboxylic dianhydride, etc., among them, preferably selected from Cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA) and norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5 At least one of ',6,6'-tetracarboxylic dianhydride (CpODA) is preferably cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA).

Examples of fluorine-containing aromatic tetracarboxylic dianhydrides that provide the structural unit A1 include: 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), 9,9-bis(trifluoro) Methyl)-9H-𠮿 -2,3,6,7-tetracarboxylic dianhydride (6FCDA) and 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride, among them, Preferably it is 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA). The tetracarboxylic dianhydride which provides the structural unit A1 does not have a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain (main skeleton).

The fluorine-free aromatic tetracarboxylic dianhydride that provides the structural unit A2 can be listed as: tetracarboxylic dianhydride formed by directly bonding two phthalic anhydrides; two phthalic anhydrides are bonded with -O-, -CO -, -NHCO-, -S-, -SO ₂ -, -CO-O-, or -CR ₂ - (R is independently H or CH ₃ or in the form of R ₂ is selected from cyclopentylene, cyclopentylene A tetracarboxylic dianhydride formed by linking two trimellitic anhydrides with diol, hydroquinone or bisphenols through an ester bond. . Providing fluorine-free aromatic tetracarboxylic dianhydride of structural unit A2, specific examples include: 4,4'-oxydiphthalic anhydride (ODPA), 3,3',4,4'-diphenylmethyl Ketotetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyltetracarboxylic dianhydride (DSDA), 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride , 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), 9,9'- Bis (3,4-dicarboxyphenyl) dianhydride (BPAF), hydroquinone diphthalic anhydride (HQDEA), ethylene glycol bis (trimellitic acid ester) dianhydride (TMEG), p-phenylene glycol Bis(trimellitate) dianhydride (TAHQ); or tetracarboxylic dianhydride in which a part of the aromatic ring of these compounds is substituted by an alkyl group, an alkoxy group, etc. Among them, it is suitable to be selected from 3 ,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), 4,4'-oxodianhydride At least one of phthalic anhydride (ODPA) and 9,9'-bis(3,4-dicarboxyphenyl)phthalic anhydride (BPAF), which is selected from 3,3',4,4'-bis Pyromellitic dianhydride (s-BPDA), 4,4'-oxydiphthalic anhydride (ODPA), 9,9'-bis(3,4-dicarboxyphenyl)benzoic anhydride (BPAF) More preferably, at least one of them is at least one selected from 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) and 4,4'-oxydiphthalic anhydride (ODPA). Even more preferably, it is 4,4'-oxydiphthalic anhydride (ODPA). The fluorine-free aromatic tetracarboxylic dianhydride providing the structural unit A2 does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain (main skeleton).

The structural unit included in the structural unit A may be one type or two or more types. When structural unit B contains one kind of structural unit, structural unit A contains two or more kinds of structural units, preferably including structural unit A1 and structural unit A2. When the structural unit included in the structural unit A includes the structural unit A1 and the structural unit A2, the tetracarboxylic dianhydride providing the structural unit included in the structural unit A is preferably selected from the group consisting of cyclohexane-1,2,4,5- Tetracarboxylic dianhydride (HPMDA) and 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA) and 4,4'-oxydiphthalic anhydride (ODPA), cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA) and 9,9'-bis(3,4-dicarboxybenzene) (BPAF), norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornan-5,5',6,6'-tetracarboxylic anhydride ( CpODA) and 4,4'-oxydiphthalic anhydride (ODPA), 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 3,3',4, 4'-biphenyltetracarboxylic dianhydride (s-BPDA), and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 9,9'-bis(3,4 -At least one combination of dicarboxyphenyl)bendicanhydride (BPAF). Among them, the one selected from the group consisting of cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA) and 3,3',4,4'- is considered to have a good balance between chemical resistance and solvent solubility. Biphenyltetracarboxylic dianhydride (s-BPDA), norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic acid At least one combination of formic anhydride (CpODA) and 4,4'-oxydiphthalic anhydride (ODPA) is better, which is cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA) and The combination of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) is even better.

When the structural unit included in the structural unit A includes the structural unit A1, the content of the structural unit A1 relative to the total amount of the structural unit A is preferably 30 to 100 mol%, more preferably 40 to 95 mol%, and 60 ~95 mol% is even better, and 60~90 mol% is even better. When the structural unit included in the structural unit A includes the structural unit A2, the content of the structural unit A2 relative to the total amount of the structural unit A is preferably 5 to 70 mol%, more preferably 5 to 60 mol%, and 5 ~40 mol% is even better, and 10~40 mol% is even better.

The structural unit A may include structural units other than the structural unit A1 and the structural unit A2. The tetracarboxylic dianhydride providing structural units other than the structural unit A1 and the structural unit A2 is not particularly limited, and examples thereof include aliphatic tetracarboxylic dianhydride such as 1,2,3,4-butane tetracarboxylic dianhydride. However, it is preferable that the tetracarboxylic dianhydride providing the structural unit A does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain (main skeleton). In addition, in this specification, aromatic tetracarboxylic dianhydride means tetracarboxylic dianhydride containing one or more aromatic rings, and alicyclic tetracarboxylic dianhydride means one containing one or more alicyclic rings and does not It means tetracarboxylic dianhydride containing aromatic ring, and aliphatic tetracarboxylic dianhydride means tetracarboxylic dianhydride containing neither aromatic ring nor alicyclic ring.

(Structural unit B) The structural unit B is a structural unit derived from the diamine represented by the following formula (2). [Chemical 4] R ² is a divalent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups. In the formula (2), R ² is a divalent organic group excluding a monocyclic aromatic group and a condensed polycyclic aromatic group, and is preferably one obtained by removing two amine groups from the diamine described below.

The structural unit B is not limited as long as it is a structural unit derived from the diamine represented by formula (2). The structural unit B is preferably a structural unit derived from at least one diamine selected from the group consisting of alicyclic diamines, aromatic diamines containing fluorine groups, polysiloxane diamines, and fluorine-free aromatic diamines, Contains structural units B1 selected from at least one selected from the group consisting of structural units derived from alicyclic diamines, structural units derived from fluorine-containing aromatic diamines, and structural units derived from polysiloxane diamines, and derived from fluorine-free The structural unit B2 of the aromatic diamine is more preferred. In addition, the structural unit B1 does not have a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain, and the structural unit B2 does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain.

Alicyclic diamines that provide structural unit B1 include: 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,4-bis(aminomethyl)cyclohexane, 1, 3-cyclohexyldiamine, 1,4-cyclohexyldiamine, isophoronediamine, bis(aminomethyl)norbornane, 4,4'-diaminodicyclohexylmethane, 4,4' -Diaminodicyclohexyl ether, 2,2-bis(4-aminocyclohexyl)propane, etc., among them, 1,3-bis(aminomethyl)cyclohexane (1,3-BAC ).

Examples of polysiloxane diamines that provide structural unit B1 include: 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,3-bis(3-aminopropyl)dimethyl diphenyldisiloxane, 1,3-bis(4-aminobutyl)tetramethyldisiloxane, and α,ω-bis(3-aminopropyl)polymethylphenylsiloxane Oxane etc.

Examples of fluorine-containing aromatic diamines that provide structural unit B1 include: 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA), 2,2'-bis (Trifluoromethyl)-4,4'-diaminobiphenyl (2,2'-TFMB), 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-5,5'-diaminobiphenyl, 2,2-bis(4-aminophenyl)hexafluoropropane (HFDA), 2,2-bis( 3-amino-4-methylphenyl)hexafluoropropane, and 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane (HFBAPP), etc., among them, the preferred It is selected from 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 2,2'-bis(trifluoromethyl)-4,4'- At least one of the diaminobiphenyls (2,2'-TFMB) is preferably 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA). The diamine providing the structural unit B1 does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain (main skeleton).

Furthermore, the total amount of the structural components derived from the fluorine-containing aromatic tetracarboxylic dianhydride in the structural unit A and the structural components derived from the fluorine-containing aromatic diamine in the structural unit B, relative to the total amount of the structural units, It is preferably 10 to 80 mol%, more preferably 10 to 60 mol%, even more preferably 20 to 60 mol%, and still more preferably 30 to 60 mol%.

Examples of fluorine-free aromatic diamines that provide structural unit B2 include: 4,4'-diaminodiphenyl ether (4,4'-ODA), 3,4'-diaminodiphenyl ether, 4,4'-Diaminodiphenylmethane (DDM), 4,4'-Diaminodiphenylsine (4,4'-DDS), 3,3'-Diaminodiphenylsine ( 3,3'-DDS), 4,4'-diamino-2,2'-dimethylbiphenyl (mTB), 9,9-bis(4-aminophenyl)fluoride (BAFL), 4 ,4'-Diaminobiphenyl (benzidine), 4,4'-Diamino-3,3'-dimethylbiphenyl, 4,4'-Diaminodiphenyl sulfide, 4, 4'-Diaminobenzophenone, 2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 5-amino-1,3, 3-Trimethyl-1-(4-aminophenyl)-indene (5-TMDM), 6-amino-1,3,3-trimethyl-1-(4-aminophenyl) )-Indene (6-TMDM), 1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl) Methylbenzyl)benzene (BisAM), 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene (BisAP), 4,4'-bis(3-aminophenoxy) )biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl (BODA), 1,1-bis(4-(4-aminophenoxy)phenyl)cyclohexane, 2 , 2-bis(4-(4-aminophenoxy)phenyl)propane (BAPP), 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-amino) Phenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, bis(4-(3-aminophenoxy)benzene )phenyl)ketone, bis(4-(4-aminophenoxy)phenyl)ketone, bis(4-(3-aminophenoxy)phenyl)sulfide, bis(4-(4- Aminophenoxy)phenyl) sulfide, bis(4-(3-aminophenoxy)phenyl)ether, bis(4-(4-aminophenoxy)phenyl)ether, bis( 4-(3-Aminophenoxy)phenyl)sine, bis(4-(4-aminophenoxy)phenyl)sine, 4,4-diaminobenzoaniline, 4-amino Benzoic acid-4-aminophenyl, 3,4-diaminobenzoaniline, etc., among them, it is suitable to be selected from 4,4'-diaminodiphenyl ether (4,4'-ODA ), 4,4'-diaminodiphenylsine (4,4'-DDS), 4,4'-diamino-2,2'-dimethylbiphenyl (mTB) and 9,9- At least one of bis(4-aminophenyl)fluoride (BAFL) is selected from 4,4'-diaminodiphenyl ether (4,4'-ODA), 4,4'-diaminodiphenyl ether More preferably, at least one of diphenylsulfone (4,4'-DDS) and 4,4'-diamino-2,2'-dimethylbiphenyl (mTB) is selected from 4,4'- At least one of diaminodiphenyl ether (4,4'-ODA) and 4,4'-diamino-2,2'-dimethylbiphenyl (mTB) is still more preferably 4,4 '-Diaminodiphenyl ether (4,4'-ODA) is even better. The fluorine-free aromatic diamine providing structural unit B2 does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain (main skeleton).

The structural unit included in the structural unit B may be one type or two or more types. When the structural unit A contains one kind of structural unit, the structural unit B includes two or more kinds of structural units, preferably including structural unit B1 and structural unit B2. When the structural unit included in the structural unit B includes the structural unit B1 and the structural unit B2, the diamine providing the structural unit included in the structural unit B is preferably selected from 1,3-bis(aminomethyl)cyclohexane (1 ,3-BAC) and 4,4'-diaminodiphenyl ether (4,4'-ODA), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl sulfane (4,4'-DDS), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether (4,4'-ODA), 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (2,2'-TFMB) and 4,4'-diaminodiphenylsulfane (4,4'-DDS), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) With 4,4'-diamino-2,2'-dimethylbiphenyl (mTB), and 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) with 9,9- At least one combination of bis(4-aminophenyl)fluoride (BAFL). Among them, the one selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diaminobis is considered to have a good balance between chemical resistance and solvent solubility. Phenyl ether (4,4'-ODA), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminobis Phenyl ether (4,4'-ODA), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diamino-2,2'-dimethyl More preferably, at least one combination of biphenyl (mTB) is selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diaminodiphenyl ether ( 4,4'-ODA), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether ( More preferably, at least one combination of 4,4'-ODA) is 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diaminodiphenyl ether The combination of (4,4'-ODA) is even better.

Rather than providing each combination of tetracarboxylic dianhydride of the structural unit included in the structural unit A, from the viewpoint of a good balance between chemical resistance and solvent solubility, a combination of diamines providing the structural unit included in the structural unit B is preferably The following combinations. Compared with the combination of cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA) and 4,4'-oxydiphthalic anhydride (ODPA), 2,2'-bis(tricarboxylic dianhydride) A combination of fluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenylsulfone (4,4'-DDS). Relative to the combination of cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA) and 9,9'-bis(3,4-dicarboxyphenyl)benzoic dianhydride (BPAF), it is preferably 2 , a combination of 2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether (4,4'-ODA) . Compared to the combination of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), Preferably, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (2,2'-TFMB) and 4,4'-diaminodiphenylsulfone (4,4 '-DDS) combination. Relative to the combination of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 9,9'-bis(3,4-dicarboxyphenyl)fluoropropane dianhydride (BPAF) , preferably 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (2,2'-TFMB) and 4,4'-diaminodiphenylsulfone (4, 4'-DDS) combination. Compared to norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic anhydride (CpODA) and 4,4' -The combination of oxydiphthalic anhydride (ODPA) is preferably 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diamino-2,2' -A combination of dimethylbiphenyl (mTB), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 9,9-bis(4-aminophenyl)fluorine (BAFL) A combination of 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether (4,4' -ODA), a combination of 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diamino-2,2'-dimethylbiphenyl (mTB) A combination of 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether (4,4' -ODA) is a better combination, which is 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diamino-2,2'-dimethylbiphenyl ( mTB) combination could not be better. For the combination of cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA) and 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), it is preferably 1, A combination of 3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diaminodiphenyl ether (4,4'-ODA), or 2,2'-bis( The combination of trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether (4,4'-ODA) is 1,3- The combination of bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diaminodiphenyl ether (4,4'-ODA) is better.

Among them, from the viewpoint of a good balance between chemical resistance and solvent solubility, the following combinations are more preferable. That is, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic anhydride (CpODA), 4, 4'-Oxydiphthalic anhydride (ODPA), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diamino-2,2'-di Combination of methylbiphenyl (mTB); norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic anhydride (CpODA), 4,4'-oxydiphthalic anhydride (ODPA), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4 , combination of 4'-diaminodiphenyl ether (4,4'-ODA); cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA), 3,3',4,4 '-Biphenyltetracarboxylic dianhydride (s-BPDA), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diaminodiphenyl ether (4, 4'-ODA) combination; cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,2'-Bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether (4,4'-ODA) The combination is better, It is norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic anhydride (CpODA), 4,4'- Oxydiphthalic anhydride (ODPA), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diamino-2,2'-dimethyldimethyl Combination of benzene (mTB); cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 1 , a combination of 3-bis(aminomethyl)cyclohexane (1,3-BAC) and 4,4'-diaminodiphenyl ether (4,4'-ODA); cyclohexane-1,2 ,4,5-tetracarboxylic dianhydride (HPMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,2'-bis(trifluoromethyl)-4, The combination of 4'-diaminodiphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether (4,4'-ODA) is even better. It is cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 1,3-bis(amine Combination of methyl)cyclohexane (1,3-BAC) and 4,4'-diaminodiphenyl ether (4,4'-ODA); cyclohexane-1,2,4,5-tetrahydrofuran Formic dianhydride (HPMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,2'-bis(trifluoromethyl)-4,4'-diamino The combination of diphenyl ether (6FODA) and 4,4'-diaminodiphenyl ether (4,4'-ODA) is even better. It is cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 1,3-bis(amine The combination of methyl)cyclohexane (1,3-BAC) and 4,4'-diaminodiphenyl ether (4,4'-ODA) is even better.

When the structural unit included in the structural unit B includes the structural unit B1, the content of the structural unit B1 relative to the total amount of the structural unit B is preferably 5 to 70 mol%, more preferably 5 to 60 mol%, and 5 ~40 mol% is even better, and 10~40 mol% is even better. When the structural unit included in the structural unit B includes the structural unit B2, the content of the structural unit B2 relative to the total amount of the structural unit B is preferably 30 to 100 mol%, more preferably 40 to 95 mol%, and 60 ~95 mol% is even better, and 60~90 mol% is even better.

The structural unit B may include structural units other than the structural unit B1 and the structural unit B2. However, it is preferable that the diamine providing the structural unit B does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as the main chain (main skeleton). The diamine providing structural units other than the structural unit B1 and the structural unit B2 is not particularly limited, and examples thereof include aliphatic diamines such as ethylene diamine and hexamethylenediamine. In addition, in this specification, aromatic diamine means a diamine containing one or more aromatic rings, and alicyclic diamine means a diamine containing one or more alicyclic rings and does not contain an aromatic ring. Aliphatic diamine refers to diamines that do not contain aromatic rings or alicyclic rings. However, in this specification, the diamine whose main chain is composed of polysiloxane is polysiloxane diamine.

<Hamaker's constant (A ₁₃₁ )> In the copolymerized polyimide of the present invention, the following formula (3) represents the Hamaker constant (A ₁₃₁ ) corresponding to the self-interaction of the aforementioned copolymerized polyimide. Relative to γ-butyrolactone, it is less than 6.65×10 ^-21 J, and relative to methyl isobutyl ketone, it is greater than 5.80×10 ^-21 J. The Hamaker constant (A ₁₃₁ ) represented by the following formula (3) will be described below. [Number 5] Here, [Number 6] K _B : Boltzmann constant, T: absolute temperature (298.15K), h: Planck's constant, n ₁ : refractive index of the aforementioned copolymerized polyimide at 25°C, n ₃ : γ at 25°C -Refractive index of butyrolactone or methyl isobutyl ketone, ε ₁ : dielectric constant of the aforementioned copolymerized polyimide at 25°C, ε ₃ : γ-butyrolactone or methyl isobutyl ketone at 25°C Dielectric constant of butyl ketone, ν _e1 : the main electron absorption vibration number of the aforementioned copolymerized polyimide (sec ^-1 ), ν _e3 : the main electron absorption vibration of γ-butyrolactone or methyl isobutyl ketone Number (second ^-1 )

The Van der Waals interaction energy between the molecular aggregates forming the macroscopic condensed phase can be assumed to be non-delayed and additive, and it can be used in the form of the sum of the pair potentials between the constituent elements, using Hamey's The gram constant is formulated. In addition, according to the Lifshitz theory applicable to the continuum model, the interaction energy between the condensed phases of the macroscopic continuum can be regarded as the interaction energy between the dielectric constant, the refractive index and the ionization energy (precisely, the main electron absorption vibration number) To deduce the overall properties of (refer to "Intermolecular Forces and Surface Forces" by JN Israelachvili, translated by Yasushi Kondo and Hiroyuki Oshima, 2nd edition, Chapter 11, Asakura Shoten, 1996, p. 173). In particular, when the solvent is "3" and the macroscopic phase is "1", when two identical macroscopic phases 1 interact with each other separated by solvent 3, and the relationship between solvent 3 and macroscopic phase 1 The exact solution when the main electron absorption vibration numbers are different provides the following formula (3), and its exact solution is the Hamaker constant (A ₁₃₁ ) (refer to L.Bergstroem, "Hamaker constants of inorganic materials" Advances in Colloid and Interface Science, Vol. Volume 70, 1997, p.136) [Number 7]

In addition, P, Q, E, K _B , T, h, ε ₁ , ε ₃ , ν _e1 , and ν _e3 in the formula (3) are as follows. [Number 8] K _B : Boltzmann constant, T: absolute temperature (298.15K), h: Planck's constant, n ₁ : refractive index of the aforementioned copolymerized polyimide at 25°C, n ₃ : γ at 25°C -Refractive index of butyrolactone or methyl isobutyl ketone, ε ₁ : dielectric constant of the aforementioned copolymerized polyimide at 25°C, ε ₃ : γ-butyrolactone or methyl isobutyl ketone at 25°C Dielectric constant of butyl ketone, ν _e1 : the main electron absorption vibration number of the aforementioned copolymerized polyimide (sec ^-1 ), ν _e3 : the main electron absorption vibration of γ-butyrolactone or methyl isobutyl ketone Number (second ^-1 )

Generally, it is believed that a condensed state is achieved when the interaction energy of two molecules or particles in contact exceeds the thermal motion that is opposite to the interaction and is intended to cause disorder. And the following conclusion is obtained: the translational motion energy of each molecule is (3/2)K _B T. If the interaction energy exceeds (3/2) K _B T, its value is enough to agglomerate the molecules or particles. Therefore, in terms of the scale of cohesion at 25°C, assuming (3/2)K _B T = 6.18×10 ^-21 (J), the Hamaker constant becomes approximately 6.18×10 ^-21 (J) or less. , it can be inferred that polyimide will dissolve in the target solvent.

In the copolymerized polyimide of the present invention, for γ-butyrolactone, the solvent used in the varnish, A ₁₃₁ is a value less than 6.65×10 ^-21 J. For A, the solvent used for the aforementioned wet treatment For isobutyl ketone, A ₁₃₁ is a value greater than 5.80×10 ^-21 J. It shows resistance to general organic solvents in a wider range than the above estimated value, and although it has excellent chemical resistance, it can The effect of being soluble in specific solvents. In the copolymerized polyimide of the present invention, the aforementioned formula (3) indicates that the Hamaker constant (A ₁₃₁ ) corresponding to the self-interaction of the aforementioned copolymerized polyimide is less than 6.65 relative to γ-butyrolactone. ×10 ^-21 J, preferably less than 6.26×10 ^-21 J relative to γ-butyrolactone. Furthermore, it is greater than 5.80×10 ^-21 J relative to methyl isobutyl ketone, and preferably greater than 6.20×10 ^-21 J relative to methyl isobutyl ketone. The aforementioned formula (3) indicates that if the Hamaker constant (A ₁₃₁ ) corresponding to the self-interaction of the aforementioned copolymerized polyimide falls within the aforementioned range, it can have higher resistance to general organic solvents and excellent chemical resistance. , but can be more easily dissolved in the specific solvents used in varnishes. γ-Butyrolactone is suitable for the production of polyimide varnishes and films containing high molecular weight polyimide, and is suitable as a criterion for evaluating the solubility of the copolymerized polyimide of the present invention. In addition, methyl isobutyl ketone is an organic solvent that can be used in wet processing during film processing, and is suitable as a criterion for evaluating the organic solvent resistance of the copolymerized polyimide of the present invention. Next, each physical property value etc. used in the said formula are demonstrated.

(Dielectric constant (ε ₁ ) of the aforementioned copolymerized polyimide at 25°C) Regarding the dielectric constant (ε ₁ ) of the aforementioned copolymerized polyimide at 25°C, the dielectric constant in the GHz band The contribution of alignment polarization and ion polarization must be considered. In the case of polyimide, it is about 10% of the electronic polarization. In the present invention, the following semi-empirical formula is used to obtain the dielectric constant (ε ₁ ) (refer to Toshihiko Matsumoto, Polymer Papers, Vol.61, No.1, 2004, p.46). ε ₁ =1.1×n ₁ ² In addition, n ₁ is the refractive index of the aforementioned copolymerized polyimide at 25°C.

(Main electron absorption vibration numbers (ν _e1 , ν _e3 ) of copolymerized polyimide, γ-butyrolactone and methyl isobutyl ketone) Copolymerized polyimide, γ-butyrolactone and methyl isobutyl ketone The main electron absorption vibration numbers (ν _e1 , ν _e3 ) of butyl ketone are obtained by calculating their main electron absorption energies (hν _e1 , hν _e3 ) and comparing these values. In addition, h is Planck's constant.

The main electron absorption energy (hν _e1 , hν _e3 ) is obtained as follows. The main electron absorption energy of the copolymerized polyimide is divided into structural units A and B in order to calculate the average value corresponding to the copolymerization ratio. Utilize the lowest unoccupied molecular orbital (LUMO) of the structural unit A after both ends are terminated with methyl groups and the highest occupied molecular orbital (LUMO) of the structural unit B after both ends are terminated with maleimide The energy gap of (Highest Occupied Molecular Orbital, HOMO) is close to the main electron absorption energy of copolymerized polyimide, and the average value is calculated using the following formula. [Number 9] However, mai is the molar fraction of component i relative to the total of component A, mbj is the molar fraction of component j relative to the total of component B, and [LUMO _Acap ] is the one after both ends are capped with methyl groups. The LUMO energy of structural unit A, [HOMO _Bcap ] is the HOMO energy of structural unit B after both ends are capped with maleimide groups.

Molecular orbital calculations were obtained using the quantum chemical calculation program GAMESS (MW Schmidt, etc. J. Comput. Chem. 14, 1347-1363 (1993)) and the DFT method (LCBOP/6-31G(d)). The calculation results of [LUMO _Acap ] and [HOMO _Bcap ] of structural unit A after end-capping are shown in Table 1.

[Table 1]

The abbreviations in Table 1 are the names of tetracarboxylic dianhydrides that provide each structural unit, or the names of diamines that provide each structural unit. As follows. HPMDA: 1,2,4,5-cyclohexanetetracarboxylic dianhydride CpODA: norbornane-2-spiro-α-cyclopentanone-α’-spiro-2’’-norbornane-5,5’,6,6’-tetracarboxylic dianhydride 6FDA: 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride s-BPDA: 3,3’,4,4’-biphenyltetracarboxylic dianhydride ODPA: 4,4’-oxydiphthalic anhydride BPAF: 9,9-bis(3,4-dicarboxyphenyl)bendicanhydride 6FODA: 2,2’-bis(trifluoromethyl)-4,4’-diaminodiphenyl ether TFMB: 2,2’-bis(trifluoromethyl)benzidine 1,3-BAC: 1,3-bis(aminomethyl)cyclohexane 4,4’-ODA: 4,4’-oxydiphenylamine mTB: 4,4’-diamino-2,2’-dimethylbiphenyl 4,4’-DDS: 4,4’-diaminodiphenyl sulfide

In addition, for the main electron absorption energy of γ-butyrolactone and methyl isobutyl ketone, and also from the molecular orbitals of the stable structure obtained by the DFT method (LCBOP/6-31G(d)) performed by GAMESS, we can find Find out the band gap energy of HOMO-LUMO and use it. The calculation results are shown in Table 2 together with other physical property values of γ-butyrolactone and methyl isobutyl ketone.

[Table 2]

＜Production method of copolymerized polyimide＞ As long as the copolymerized polyimide meets the aforementioned constitution, the production method is not particularly limited, but it is preferable to use the method shown below. The method for producing the copolymerized polyimide is preferably a method of polymerizing diamine and tetracarboxylic dianhydride, and a more preferred method is a method of polymerizing diamine and tetracarboxylic dianhydride in the presence of an aprotic solvent. , it is even better to produce a method in which diamine and tetracarboxylic dianhydride are polymerized in the presence of an aprotic solvent with a refractive index of 1.42 or higher at 25°C. By polymerizing diamine and tetracarboxylic dianhydride in the presence of an aprotic solvent with a refractive index of 1.42 or higher at 25°C, it is possible to obtain a polymer that is resistant to general-purpose organic solvents and has excellent chemical resistance but is soluble. Copolymerized polyimide in specific solvents.

The method of polymerizing tetracarboxylic dianhydride and diamine is not particularly limited, and a known method can be used. Specific reaction methods include: (1) Feed the tetracarboxylic acid component, diamine component and reaction solvent into a reaction vessel, stir at 10~110°C for 0.5~3 hours, and then raise the temperature to implement the imidization reaction. Method, (2) After feeding the diamine component and the reaction solvent into the reaction vessel and dissolving them, feed the tetracarboxylic acid component, and stir at 10~110°C for 0.5~3 hours as needed, and then raise the temperature to perform fermentation. The method of imidization reaction, (3) the method of feeding the tetracarboxylic acid component, the diamine component and the reaction solvent into the reaction vessel, and immediately raising the temperature to carry out the imidization reaction, etc.

The imidization reaction is preferably carried out using a Dean-Stark apparatus or the like, while removing water generated during production. By performing such an operation, the degree of polymerization and the acyl imidization rate can be further increased.

In the above-mentioned imidization reaction, a known imidization catalyst can be used. Examples of imidization catalysts include alkali catalysts or acid catalysts. Examples of alkali catalysts include: pyridine, quinoline, isoquinoline, α-methylpyridine, β-methylpyridine, 2,4-dimethylpyridine, 2,6-dimethylpyridine, trimethylamine, triethylamine, tripropylamine , tributylamine, triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline and other organic alkali catalysts; potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, carbonic acid Potassium hydrogen, sodium bicarbonate and other inorganic alkali catalysts. Examples of acid catalysts include: crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, toluic acid, hydroxybenzoic acid, terephthalic acid, benzenesulfonic acid, and p-toluenesulfonic acid , naphthalenesulfonic acid, etc. The above-mentioned imidization catalyst can be used alone or in combination of two or more types. Among the above, from the viewpoint of operability, an alkali catalyst is preferred, an organic alkali catalyst is more preferred, and one or more catalysts selected from triethylamine and triethylenediamine is more preferred, and triethylamine and triethylenediamine are more preferred. Better.

The temperature of the imidization reaction is preferably 120 to 250°C, more preferably 160 to 200°C, considering the reaction rate and inhibition of gelation. In addition, the reaction time is preferably 0.5 to 10 hours after the distillation of the generated water starts. The solid content concentration of the imidization reaction is preferably 30 to 60 mass%, more preferably 35 to 58 mass%, and even more preferably 40 to 56 mass%. The solid content concentration during the imidization reaction is a value calculated using the following formula. Solid content concentration (mass %) = (total mass of tetracarboxylic acid component and diamine component)/(total mass of tetracarboxylic acid component, diamine component and solvent) × 100 Next, the raw materials used in the production method of copolymerized polyimide will be described.

[Tetracarboxylic dianhydride (tetracarboxylic acid component)] In the method for producing a copolymerized polyimide, the tetracarboxylic dianhydride (hereinafter also referred to as a tetracarboxylic acid component) used as a raw material contains the tetracarboxylic dianhydride that provides the aforementioned structural unit A. The above-mentioned tetracarboxylic dianhydride is the same as the tetracarboxylic dianhydride explained in the above item (structural unit A). In addition, the tetracarboxylic dianhydride that provides the structural unit A is preferably selected from the group consisting of alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride containing a fluorine group, and fluorine-free aromatic tetracarboxylic dianhydride. More preferably, at least one of them includes at least one selected from the group consisting of alicyclic tetracarboxylic dianhydride and fluorine-containing aromatic tetracarboxylic dianhydride, and fluorine-free aromatic tetracarboxylic dianhydride. In addition, the tetracarboxylic dianhydride providing the structural unit A does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain. Examples of the tetracarboxylic dianhydride include acid dianhydride, but it is not limited thereto, and its derivatives may also be used. Examples of such derivatives include tetracarboxylic acid (free acid) and alkyl esters of the tetracarboxylic acid. Among them, acid dianhydride is preferred.

[Diamine] In the method for producing copolymerized polyimide, the diamine used as a raw material (hereinafter also referred to as a diamine component) contains the diamine providing the aforementioned structural unit B. The said diamine is the same as the diamine demonstrated in the above (structural unit B) item. In addition, the diamine providing the structural unit B is preferably at least one diamine selected from the group consisting of alicyclic diamines, aromatic diamines containing fluorine groups, polysiloxane diamines, and fluorine-free aromatic diamines. Amine includes at least one diamine selected from the group consisting of structural units derived from alicyclic diamines, structural units derived from fluorine-containing aromatic diamines, and structural units derived from polysiloxane diamines, as well as fluorine-free aromatic Family diamines are better. In addition, the diamine providing the structural unit B does not have only a monocyclic aromatic group and a condensed polycyclic aromatic group as a main chain. Examples of the diamine include, but are not limited to, diamines. Derivatives thereof may be used as long as they are within the range of providing the structural unit B in the polymer. Examples of such derivatives include salts corresponding to diamines such as diisocyanate, bismethamide, and carbonate. Among them, diamine is preferred.

[Solvent] The solvent used in the manufacturing method of copolymerized polyimide is suitable as long as it does not hinder the imidization reaction and can dissolve the produced copolymerized polyimide. It is preferably an aprotic solvent. An aprotic solvent with a refractive index (n ₂₅ ) of 1.42 or more at 25°C is more preferred, and a non-aromatic aprotic solvent with a refractive index of 1.42 or more at 25°C is even more preferred. In addition, it is preferable to use an aprotic polar solvent with a boiling point of 160°C or higher.

Specific examples include: N,N-dimethylformamide (n ₂₅ =1.428), N,N-dimethylacetamide (n ₂₅ =1.436), N-methyl-2-pyrrolidone (n ₂₅ = 1.468), tetramethylurea (n ₂₅ =1.449), γ-butyrolactone (n ₂₅ =1.435), γ-valerolactone (n ₂₅ =1.431), dimethylsulfoxide (n ₂₅ =1.478), Cyclotene (n ₂₅ =1.480), cyclopentanone (n ₂₅ =1.435), cyclohexanone (n ₂₅ =1.448), dichloromethane (n ₂₅ =1.422), etc., among which, are highly transparent and soluble High molecular weight copolymerized polyimide and γ-butyrolactone suitable for the manufacture of varnishes and films are particularly preferred. The above-mentioned solvents may be used alone or in combination of two or more types.

[varnish] The varnish of the copolymerized polyimide of the present invention is not particularly limited, and it is preferable to contain an aprotic solvent with a refractive index of 1.42 or above at 25°C. That is, the varnish of the present invention preferably contains the aforementioned copolymerized polyimide and an aprotic solvent with a refractive index of 1.42 or more at 25°C. Preferably, it is a polyimide varnish in which the copolymerized polyimide of the present invention is dissolved in an aprotic solvent.

The varnish of the present invention may be the copolymerized polyimide solution itself obtained by the above-mentioned manufacturing method of copolymerized polyimide, may be obtained by adding a further solvent, or may be obtained by reducing the solvent by concentration or the like. , it may also be obtained by adding a poor solvent to the copolymerized polyimide solution obtained by the above-mentioned manufacturing method of copolymerized polyimide, powderizing the solution, filtering, washing, and drying, and then dissolving it in the solvent. By.

The solvent contained in the aforementioned varnish can dissolve the aforementioned copolymerized polyimide, and is preferably an aprotic solvent, preferably an aprotic solvent with a refractive index (n ₂₅ ) of 1.42 or above at 25°C. It is more preferably a non-aromatic aprotic solvent with a refractive index of 1.42 or more at 25°C.

Specific examples include: N,N-dimethylformamide (n ₂₅ =1.428), N,N-dimethylacetamide (n ₂₅ =1.436), N-methyl-2-pyrrolidone (n ₂₅ = 1.468), tetramethylurea (n ₂₅ =1.449), γ-butyrolactone (n ₂₅ =1.435), γ-valerolactone (n ₂₅ =1.431), dimethylsulfoxide (n ₂₅ =1.478), Cyclotene (n ₂₅ =1.480), cyclopentanone (n ₂₅ =1.435), cyclohexanone (n ₂₅ =1.448), dichloromethane (n ₂₅ =1.422), etc. Among them, those with high transparency and soluble high molecular weight Copolymerized polyimide and γ-butyrolactone are particularly suitable for film production. The above-mentioned solvents may be used alone or in combination of two or more types. That is, the aprotic solvent with a refractive index of 1.42 or more at 25° C. contained in the varnish of the present invention contains γ-butyrolactone. The aforementioned varnish preferably contains 5 to 40 mass % of the copolymerized polyimide resin of the present invention, and more preferably 10 to 30 mass %. The viscosity of the aforementioned varnish is preferably 1 to 200 Pa･s, preferably 5 to 150 Pa･s. The viscosity of the aforementioned varnish is measured using an E-type viscometer at 25°C. In addition, the aforementioned varnish may also contain inorganic fillers, adhesion accelerators, release agents, flame retardants, ultraviolet stabilizers, surfactants, and leveling agents within the range that does not impair the required characteristics of the obtained polyimide film. Agents, defoaming agents, fluorescent whitening agents, cross-linking agents, polymerization initiators, photosensitizers and other additives.

[Polyimide film and manufacturing method of polyimide film] The polyimide film of the present invention is composed of the aforementioned copolymerized polyimide. In addition, the method of manufacturing the polyimide film of the present invention is not particularly limited, and a known method can be used. Preferably, the method includes coating the varnish on a support and removing the aprotic solvent. Specific examples include a method in which the varnish is coated on a smooth support such as a glass plate, a metal plate, or plastic, and formed into a film, and then the aprotic solvent contained in the varnish is removed by heating. The surface of the aforementioned support may also be coated with a release agent in advance if necessary. A suitable method for removing the organic solvent contained in the varnish by heating is as follows. That is, after evaporating the organic solvent at a temperature of 120° C. or lower to form a self-standing supporting film, the self-standing supporting film is peeled off from the support, and the ends of the self-standing supporting film are fixed to the organic solvent used. It is ideal to produce a polyimide film by drying at a temperature above the boiling point. In addition, it is suitable to dry in a nitrogen environment. The pressure of the dry environment can be any of reduced pressure, normal pressure, and pressurization. The heating temperature when drying the self-supporting film to produce a polyimide film is not particularly limited, but is preferably 200 to 400°C. When the aprotic solvent contained in the varnish has a boiling point of a low-boiling point solvent of 130°C or lower, the heating temperature of the self-supporting film is preferably 100 to 180°C. In addition, it is preferable to perform annealing treatment in which the polyimide film obtained by removing the low-boiling point solvent is heated to a temperature higher than the glass transition temperature.

The thickness of the polyimide film of the present invention can be appropriately selected according to the application, etc., and is preferably 1 to 250 μm, more preferably 5 to 100 μm, and even more preferably 5 to 50 μm. With a thickness of 1~250μm, it can be made into a self-supporting film for practical use. The thickness of the polyimide film can be easily controlled by adjusting the solid content concentration and viscosity of the varnish, and the amount of varnish during coating.

The polyimide film of the present invention can be ideally used as a film for various components such as color filters, flexible displays, semiconductor components, and optical components. The polyimide film of the present invention can be ideally used as a substrate for image display devices such as liquid crystal displays and OLED displays. [Example]

The present invention will be explained concretely below using examples. However, the present invention is not limited by these examples. The physical properties and evaluation of the polyimide films obtained in Examples and Comparative Examples were carried out using the methods shown below.

(1) Average refractive index of copolymerized polyimide Use a prism coupling refractive index measuring device (model 2010/M) manufactured by Metricon to measure the X at 594 nm of the polyimide films obtained in the Examples and Comparative Examples. The refractive index (n _x , n _y , n _z ) in each direction of the axis, Y axis, and Z axis, and the average refractive index (n) is calculated using the following formula. n=(n _x +n _y +n _z )/3

(2) Hamaker’s constant (A ₁₃₁ ) Hamaker’s constant (A ₁₃₁ ) is the self-interaction of the copolymerized polyimide (polyimide film) obtained in the examples and comparative examples represented by the aforementioned formula (3) The Hamaker constant (A ₁₃₁ ) corresponding to the action is calculated as above. The Hamaker constant (A _1(GBL)1 ) relative to γ-butyrolactone and relative to methyl isobutyl The Hamaker constant (A _{1 (MIBK) 1} ) of ketones is shown in Tables 3 to 5.

(3) GBL (γ-butyrolactone) solubility The polyimide film was immersed in GBL (γ-butyrolactone) and left at 23°C for 24 hours. Thereafter, the state of the polyimide film in the impregnated GBL was observed. The evaluation criteria for GBL solubility were set as follows. The more soluble the polyimide film is, the better the solubility of GBL (γ-butyrolactone) will be. A: The polyimide film is completely dissolved. B: The shape of the polyimide film cannot be maintained, but some dissolved residues are still observed. C: There is no change in the surface of the polyimide film and the film shape is maintained.

(4)MIBK (methyl isobutyl ketone) resistance The polyimide film was immersed in MIBK (methyl isobutyl ketone) and left at 23°C for 24 hours. Thereafter, the state of the polyimide film in the immersed MIBK was observed. The evaluation criteria for MIBK resistance were set as follows. The more insoluble the polyimide film is and the more the film shape remains, the better MIBK (methyl isobutyl ketone) resistance is. A: There is no change in the film surface and the film shape is maintained. B: The shape of the film is maintained, but cracks or white turbidity are observed on the surface. C: The film is completely dissolved.

The tetracarboxylic acid component and diamine component used in the Examples and Comparative Examples and their abbreviations are as follows. ＜Tetracarboxylic dianhydride＞ HPMDA: 1,2,4,5-cyclohexanetetracarboxylic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) CpODA: Norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic dianhydride (manufactured by JFE Chemical Co., Ltd. ) 6FDA: 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (manufactured by Daikin Industries Co., Ltd.) s-BPDA: 3,3’,4,4’-biphenyltetracarboxylic dianhydride (manufactured by Mitsubishi Chemical Co., Ltd.) ODPA: 4,4’-oxydiphthalic anhydride (Manac Co., Ltd.) BPAF: 9,9-bis(3,4-dicarboxyphenyl)bendicanhydride (manufactured by JFE Chemical Co., Ltd.) ＜Diamine＞ 6FODA: 2,2’-bis(trifluoromethyl)-4,4’-diaminodiphenyl ether (manufactured by ChinaTech Chemical (Taijin) Co., Ltd.) TFMB: 2,2’-bis(trifluoromethyl)benzidine (manufactured by Wakayama Seika Industry Co., Ltd.) 1,3-BAC: 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 4,4’-ODA: 4,4’-oxydiphenylamine (manufactured by Wakayama Seika Industry Co., Ltd.) mTB: 4,4’-diamino-2,2’-dimethylbiphenyl (manufactured by Wakayama Seika Industry Co., Ltd.) 4,4’-DDS: 4,4’-Diaminodiphenylsine (manufactured by Wakayama Seika Industry Co., Ltd.) BAFL: 9,9-bis(4-aminophenyl)fluoride (manufactured by Tagoka Chemical Industry Co., Ltd.)

The abbreviations of solvents and catalysts used in Examples and Comparative Examples are as follows. GBL: γ-butyrolactone (produced by Mitsubishi Chemical Co., Ltd., GBL) NMP: N-methyl-2-pyrrolidone (manufactured by Tokyo Junyaku Industry Co., Ltd.) TEA: Triethylamine (made by Kanto Chemical Co., Ltd.)

[Manufacture of polyimide film] Example 1 In a 300mL 5-neck round bottom flask equipped with a stainless steel half-moon stirring blade, a nitrogen inlet pipe, a Dean-Stark device equipped with a cooling pipe, a thermometer, and a glass end cap, add 4. 4'-DDS 8.730g (0.0352 mole) and 6FODA 7.881g (0.0234 mole), GBL 20.7g as an organic solvent, and TEA 0.302g as an imidization catalyst, in a system temperature of 70°C and a nitrogen environment Then, stir at 150 rpm to obtain a solution. HPMDA 9.195g (0.0410 mole) and ODPA 5.453g (0.0176 mole) as tetracarboxylic acid components, and GBL 23.0g as an additional organic solvent were added at once, and then heated with a mantle heater for a period of time The temperature in the reaction system was raised to 190°C for 20 minutes. The water was distilled off, and the rotation speed was adjusted according to the increase in viscosity. At the same time, the temperature in the reaction system was maintained at 190°C and refluxed for 2 hours to obtain a polyimide solution. Thereafter, the temperature in the reaction system was cooled to 120° C., 72.8 g of GBL for dilution was added, and the mixture was stirred for another 3 hours to obtain a polyimide varnish with a solid content concentration of 20.0% by mass. Then, the obtained polyimide varnish is coated on the glass substrate and kept at 60°C for 20 minutes, 80°C for 20 minutes, and 100°C for 30 minutes to evaporate the solvent, thereby obtaining a self-supporting glass substrate. A transparent once-drying film is then fixed on a stainless steel frame and heated at 220°C in an air environment for 20 minutes to remove the solvent and obtain a polyimide film. The physical properties and evaluation results of the film are shown in Table 3.

Comparative example 1 Change the amount of 4,4'-DDS as the diamine component to 1.339g (0.0054 mole), change the amount of 6FODA to 16.322g (0.0485 mole), and change the amount of HPMDA as the tetracarboxylic acid component to 8.464g (0.0378 mol), except that the amount of ODPA was changed to 5.020 g (0.0162 mol), the same method as in Example 1 was used to obtain a polyimide varnish with a solid content concentration of 20.0 mass %. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 3.

Comparative example 2 In a 300mL 5-neck round bottom flask equipped with a stainless steel half-moon stirring blade, a nitrogen inlet pipe, a Dean Stark equipped with a cooling pipe, a thermometer, and a glass end cap, add 4,4 as the diamine component '-DDS 13.587g (0.0547 mole), 6FODA 2.044g (0.0061 mole), and NMP 40.9g as an organic solvent were stirred at a rotation speed of 150rpm under a system temperature of 50°C and a nitrogen atmosphere to obtain a solution. HPMDA 9.541g (0.0426 mol) and ODPA 5.658g (0.0182 mol) as tetracarboxylic acid components, and NMP 30.0g as an additional organic solvent were added to this solution at one time, and kept at 50°C with a heating pack. Stir for 7 hours. Thereafter, 102.7 g of NMP was added, and the mixture was stirred for another 3 hours to obtain a polyamic acid varnish with a solid content concentration of 15.0% by mass. Then, the obtained polyamic acid composition varnish was applied to the glass plate, and was maintained at 60°C for 20 minutes, 80°C for 20 minutes, and 100°C for 30 minutes. Thereafter, it was moved to a hot air dryer, and in a nitrogen environment, the temperature was raised to 420°C at a heating rate of 5°C/min, and then heated at 420°C for 60 minutes to remove the solvent and thermally imidize it to obtain the polyethylene. Imide film. The physical properties and evaluation results of the film are shown in Table 3.

Example 2 In a 300mL 5-neck round bottom flask equipped with a stainless steel half-moon stirring blade, a nitrogen inlet pipe, a Dean-Stark device equipped with a cooling pipe, a thermometer, and a glass end cap, add 4. 4'-ODA 5.086g (0.0254 mol) and 6FODA 8.540g (0.0254 mol), GBL 20.7g as an organic solvent, and TEA 0.304g as an imidization catalyst, in a system temperature of 70°C and a nitrogen environment Then, stir at 150 rpm to obtain a solution. HPMDA 5.694g (0.0254 mole) and BPAF 11.644g (0.0254 mole) as tetracarboxylic acid components, and GBL 23.0g as an additional organic solvent were added at once, and then heated with a heating pack and the reaction lasted 20 minutes. The temperature in the system increased to 190°C. The water was distilled off, and the rotation speed was adjusted according to the increase in viscosity. At the same time, the temperature in the reaction system was maintained at 190°C and refluxed for 2 hours to obtain a polyimide solution. Thereafter, the temperature in the reaction system was cooled to 120° C., 72.8 g of GBL for dilution was added, and the mixture was stirred for another 3 hours to obtain a polyimide varnish with a solid content concentration of 20.0% by mass. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 3.

Example 3 Change the amount of 4,4'-ODA as the diamine component to 9.531g (0.0476 mole), change the amount of 6FODA to 6.859g (0.0204 mole), and change the amount of HPMDA as the tetracarboxylic acid component to 15.244 g (0.0680 mol), except that BPAF was not used, the same method as in Example 2 was used to obtain a polyimide varnish with a solid content concentration of 20.0 mass %. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 3.

Example 4 The amount of 4,4'-ODA as the diamine component was changed to 12.735g (0.0636 mole), 6FODA was not used, the amount of HPMDA as the tetracarboxylic acid component was changed to 9.980g (0.0445 mole), and the amount of BPAF was changed Except that the amount was changed to 8.747 g (0.0191 mol), the same method as in Example 2 was used to obtain a polyimide varnish with a solid content concentration of 20.0 mass %. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 3.

Comparative example 3 The amount of 4,4'-ODA as the diamine component was changed to 11.546g (0.0577 mole), 6FODA was not used, the amount of HPMDA as the tetracarboxylic acid component was changed to 6.463g (0.0288 mole), and the amount of BPAF was changed Except that the amount was changed to 13.216 g (0.0288 mol), the same method as in Example 2 was used to obtain a polyimide varnish with a solid content concentration of 20.0 mass %. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 3.

Example 5 In a 300mL 5-neck round bottom flask equipped with a stainless steel half-moon stirring blade, a nitrogen inlet pipe, a Dean-Stark device equipped with a cooling pipe, a thermometer, and a glass end cap, add 4. 4'-DDS 5.860g (0.0236 mol) and TFMB 7.558g (0.0236 mol), GBL 20.7g as an organic solvent, and TEA 0.234g as an imidization catalyst, in a system temperature of 70°C and a nitrogen environment Then, stir at 150 rpm to obtain a solution. 6FDA 10.484g (0.0236 mole) and s-BPDA 6.944g (0.0236 mole) as tetracarboxylic acid components, and GBL 23.0g as an additional organic solvent were added at once, and then heated with a heating pack for 20 minutes. Increase the temperature in the reaction system to 190°C. The water was distilled off, and the rotation speed was adjusted according to the increase in viscosity. At the same time, the temperature in the reaction system was maintained at 190°C and refluxed for 2 hours to obtain a polyimide solution. Thereafter, the temperature in the reaction system was cooled to 120° C., 16.3 g of GBL for dilution was added, and the mixture was stirred for another 3 hours to obtain a polyimide varnish with a solid content concentration of 20.0% by mass. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 4.

Example 6 Change the amount of 4,4'-DDS as the diamine component to 9.713g (0.0391 mol), change the amount of TFMB to 3.132g (0.0098 mol), and change the amount of 6FDA as the tetracarboxylic acid component to 10.862g (0.0245 mol), except that the amount of s-BPDA was changed to 7.194 g (0.0245 mol), the same method as in Example 5 was used to obtain a polyimide varnish with a solid content concentration of 20.0 mass %. . The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 4.

Example 7 Change the amount of 4,4'-DDS as the diamine component to 6.302g (0.0254 mol), change the amount of TFMB to 5.418g (0.0169 mol), and change the amount of 6FDA as the tetracarboxylic acid component to 13.154 g (0.0296 mol), except that s-BPDA was not used and BPAF 5.817 g (0.0127 mol) was used. The same method as in Example 5 was used to obtain a polyimide with a solid content concentration of 20.0 mass %. Varnish. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 4.

Example 8 In a 300mL 5-neck round bottom flask equipped with a stainless steel half-moon stirring blade, a nitrogen inlet pipe, a Dean-Stark device equipped with a cooling pipe, a thermometer, and a glass end cap, add 1 of the diamine ingredients. 3-BAC 4.246g (0.0299 mole) and mTB 6.337g (0.0299 mole), GBL 20.7g as an organic solvent, and TEA 0.264g as an imidization catalyst, under a system temperature of 70°C and a nitrogen environment , stir at a rotation speed of 150 rpm and obtain a solution. CpODA 11.474g (0.0299 mole) and ODPA 9.260g (0.0299 mole) as tetracarboxylic acid components, and GBL 23.0g as an additional organic solvent were added at once, and then heated with a heating pack, and the reaction lasted 20 minutes. The temperature in the system increased to 190°C. The water was distilled off, and the rotation speed was adjusted according to the increase in viscosity. At the same time, the temperature in the reaction system was maintained at 190°C and refluxed for 2 hours to obtain a polyimide solution. Thereafter, the temperature in the reaction system was cooled to 120° C., 72.8 g of GBL for dilution was added, and the mixture was stirred for another 3 hours to obtain a polyimide varnish with a solid content concentration of 20.0% by mass. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 4.

Example 9 The amount of 1,3-BAC as the diamine component was changed to 3.727g (0.0262 mol), mTB was not used, and BAFL 9.129g (0.0262 mol) was used. The amount of CpODA as the tetracarboxylic acid component was changed to 10.071g. (0.0262 mol), except that the amount of ODPA was changed to 8.128 g (0.0262 mol), the same method as in Example 8 was used to obtain a polyimide varnish with a solid content concentration of 20.0 mass %. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 4.

Example 10 Do not use 1,3-BAC as the diamine component, do not use mTB, use BAFL 15.401g (0.0442 mole), change the amount of CpODA as the tetracarboxylic acid component to 8.495g (0.0221 mole), and change the amount of ODPA Except that the amount was changed to 6.856 g (0.0221 mol), the same method as in Example 8 was used to obtain a polyimide varnish with a solid content concentration of 20.0 mass %. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 4.

Examples 11~14 Except that the types and proportions of the diamine component and the tetracarboxylic acid component were changed as shown in Table 5, the same method as in Example 8 was used to obtain a polyimide varnish with a solid content concentration of 20.0 mass %. The obtained polyimide varnish was used, and a polyimide film was obtained in the same manner as in Example 1. The physical properties and evaluation results of the film are shown in Table 5.

[table 3]

[Table 4]

[table 5]

As shown in Tables 3 to 5, it can be seen that the polyimide film composed of the copolymerized polyimide of the present invention has excellent resistance to methyl isobutyl ketone used in wet processing during film processing, and It has excellent solubility in γ-butyrolactone, which is suitable for the production of polyimide varnishes and films. In this way, the copolymerized polyimide of the present invention has resistance to general organic solvents and has excellent chemical resistance, but is soluble in specific solvents, so it can be used as a varnish.

Claims (11)

A copolymerized polyimide containing: a structural unit A derived from a tetracarboxylic dianhydride represented by the following formula (1), and a structural unit B derived from a diamine represented by the following formula (2), and the structural unit A is composed of At least one of the units B is two or more structural units; The Hamaker constant (A ₁₃₁ ) corresponding to the self-interaction of the copolymerized polyimide represented by the following formula (3) is relative to γ -Butyrolactone, less than 6.65×10 ^-21 J, and relative to methyl isobutyl ketone, greater than 5.80×10 ^-21 J; R ¹ is a 4-valent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups, R ² is a divalent organic group excluding monocyclic aromatic groups and condensed polycyclic aromatic groups; here, K _B : Boltzmann constant, T: absolute temperature (298.15K), h: Planck constant, n ₁ : refractive index of the copolymerized polyimide at 25°C, n ₃ : The refractive index of γ-butyrolactone or methyl isobutyl ketone at 25°C, ε ₁ : The dielectric constant of the copolymerized polyimide at 25°C, ε ₃ : γ-butyrolactone at 25°C Dielectric constant of lactone or methyl isobutyl ketone, ν _e1 : main electron absorption vibration number of the copolymerized polyimide (second ^-1 ), ν _e3 : γ-butyrolactone or methyl isobutyl ketone The main electron absorption vibration number of ketone (second ^-1 ). The copolymerized polyimide of claim 1, wherein the Hamaker constant (A ₁₃₁ ) corresponding to the self-interaction of the copolymerized polyimide represented by the formula (3) is relative to γ-butyrolactone , less than 6.26×10 ^-21 J, compared to methyl isobutyl ketone, larger than 6.20×10 ^-21 J. The copolymerized polyimide of claim 1, wherein the structural unit A is two or more kinds of structural units, and the structural unit B is two or more kinds of structural units. The copolymerized polyimide of claim 3, wherein the structural unit A contains at least one selected from the group consisting of structural units derived from alicyclic tetracarboxylic dianhydride and structural units derived from fluorine-containing aromatic tetracarboxylic dianhydride. A structural unit A1 and a structural unit A2 derived from fluorine-free aromatic tetracarboxylic dianhydride, The structural unit B contains at least one structural unit B1 selected from the group consisting of structural units derived from alicyclic diamines, structural units derived from fluorine-containing aromatic diamines, and structural units derived from polysiloxane diamines, and structural units derived from different Structural unit B2 of fluorine-containing aromatic diamine. Such as the copolymerized polyimide of claim 4, wherein the structural unit A2 is selected from the group consisting of two phthalic anhydrides with a single bond, -O-, -CO-, -NHCO-, -S-, -SO ₂ The structural units of tetracarboxylic dianhydride linked by -, -COO- or -CR ₂ - and derived from two trimellitic anhydrides and glycols, hydroquinone, or bisphenols linked by ester bonds At least one of the structural units of tetracarboxylic dianhydride, and the R is independently H or CH ₃ , or R ₂ is at least one selected from cyclopentylene, cyclohexylene or 9-benzene. Based on the base, the content of the structural unit A2 is 5 to 40 mol% relative to the total amount of the structural unit A. The copolymerized polyimide of Claim 4, wherein the structural component in the structural unit A is derived from a fluorine-containing aromatic tetracarboxylic dianhydride and the structural component in the structural unit B is derived from a fluorine-containing aromatic diamine. The total amount is 10~60 mol% relative to the total amount of constituent units. A method for manufacturing copolymerized polyimide, which is a method for manufacturing the copolymerized polyimide according to any one of claims 1 to 6, The diamine and tetracarboxylic dianhydride are polymerized in the presence of an aprotic solvent with a refractive index of 1.42 or more at 25°C. A varnish containing: Such as the copolymerized polyimide of any one of claims 1 to 6, and An aprotic solvent with a refractive index of 1.42 or above at 25°C. The varnish of claim 8, wherein the aprotic solvent having a refractive index of 1.42 or more at 25°C contains γ-butyrolactone. A polyimide film is composed of the copolymerized polyimide in any one of claims 1 to 6. A method for manufacturing a polyimide film is to apply the varnish of claim 8 on a support and remove the aprotic solvent.