JP6786861B2 - Polyimide precursor, polyimide, polyimide film, polyimide laminate, polyimide / hard coat laminate - Google Patents

Description

The present invention relates to a polyimide precursor, a polyimide, a polyimide film, a polyimide laminate, a polyimide / hard coat laminate, etc., which are excellent in surface hardness, transparency, and adhesion.

In recent years, with the advent of the advanced information society, the development of optical materials such as optical fibers and optical waveguides in the optical communication field, liquid crystal alignment films in the display device field, and protective films for color filters has been progressing. Especially in the field of display devices, a lightweight and highly flexible plastic substrate is being studied as an alternative to a glass substrate, and a display that can be bent or rolled is being actively developed. In addition, a plastic cover sheet is being studied as an alternative to the cover glass that protects the display surface of the display. Therefore, there is a demand for a higher performance optical material that can be used for such applications.

Aromatic polyimides are essentially tan due to intramolecular conjugation and formation of charge transfer complexes. Therefore, as a means for suppressing coloring, for example, by introducing a fluorine atom into the molecule, imparting flexibility to the main chain, or introducing a bulky group as a side chain, the formation of intramolecular conjugation or charge transfer complex is inhibited. Then, a method for expressing transparency has been proposed.

Further, a method of expressing transparency by using a semi-alicyclic or full alicyclic polyimide that does not form a charge transfer complex in principle has also been proposed. In particular, a highly transparent semi-alicyclic polyimide using an aromatic tetracarboxylic dianhydride as a tetracarboxylic acid component and an alicyclic diamine as a diamine component, and an alicyclic tetracarboxylic dianide as a tetracarboxylic acid component. Many highly transparent semi-alicyclic polyimides using aromatic diamine as an anhydride and diamine component have been proposed.

In Patent Document 1, in order to obtain a thin, light, and hard-to-break active matrix display device, a normal film-forming process is used on a transparent polyimide film substrate in which a tetracarboxylic acid component residue is an aliphatic group. It is disclosed that a thin film transistor is formed to obtain a thin film transistor substrate. The polyimide specifically used here was prepared from 1,2,4,5-cyclohexanetetracarboxylic dianhydride as a tetracarboxylic acid component and 4,4'-diaminodiphenyl ether as a diamine component. It is a thing.

Patent Document 2 describes a colorless transparent resin film made of polyimide having excellent colorless transparency, heat resistance and flatness, which is used for a transparent substrate of a liquid crystal display element, an organic EL display element, a thin film transistor substrate, a flexible wiring substrate, and the like. A production method obtained by a solution casting method using a specific drying step is disclosed. The polyimides used here are 1,2,4,5-cyclohexanetetracarboxylic dianhydride, which is a tetracarboxylic acid component, and α, α'-bis (4-aminophenyl) -1, which is a diamine component. It is prepared from 4-diisopropylbenzene and 4,4'-bis (4-aminophenoxy) biphenyl.

Patent Documents 3 and 4 describe dicyclohexyltetracarboxylic dian as a tetracarboxylic dian component and diaminodiphenyl ether, diaminodiphenylmethane, 1,4-bis (4-aminophenoxy) benzene, and 1,3- as diamine components. Bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] ) Benzene] A polyimide that is soluble in an organic solvent using ether or metaphenylenediamine is described.

However, depending on the application, a polyimide or a polyimide film having high surface hardness and adhesion to other materials in addition to excellent transparency is required. For example, a cover sheet that protects the display surface of a display needs to have high transparency, high surface hardness, and adhesion to other materials. Further, the substrate for a display is required to have high transparency, and particularly in the case of a flexible type display, the substrate may also be required to have a high elastic modulus in addition to high transparency.

On the other hand, in Patent Document 5, 1,2,3,4-cyclobutanetetracarboxylic dianhydride was used as the tetracarboxylic acid component, and aromatic diamines such as 4,4'-diaminodiphenylmethane and aniline were used as the diamine component. Polyimide is disclosed as an imide compound useful as a constituent of a liquid crystal alignment agent. In Patent Document 9, a polyimide using 1,2,3,4-cyclobutanetetracarboxylic dianhydride as a tetracarboxylic acid component and 2,2'-dimethyl-4,4'-diaminobiphenyl as a diamine component is used. A liquid crystal alignment agent containing the above is disclosed.

In Patent Document 6, 1,2,3,4-cyclobutanetetracarboxylic dianhydride was used as a tetracarboxylic acid component, and 4,4'-diaminodiphenylmethane and 3,3'-dihydroxybenzidine were used as diamine components. Polyethylene, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride as tetracarboxylic acid components, and 4,4'-diaminodiphenylmethane and 3,3'-dihydroxy as diamine components. A polyimide-containing liquid crystal aligning agent using benzidine is disclosed.

Patent Document 7 describes 1,2,3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic acid as tetracarboxylic acid components, and 3,3'-dihydroxybenzidine and other diamines as diamine components. , A liquid crystal aligning agent containing a polyimide using monoamine is disclosed.

Patent Document 8 describes 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanedidianhydride and biphenyltetracarboxylic dianhydride as the tetracarboxylic acid component, and bistrifluoromethylbenzidine as the diamine component. A laminate of transparent polyimide and a hard coat using the above is described.

Japanese Unexamined Patent Publication No. 2003-168800 International Publication No. 2008/146637 JP-A-2002-69179 JP-A-2002-146021 Japanese Unexamined Patent Publication No. 9-71649 JP-A-2015-106156 Japanese Unexamined Patent Publication No. 2013-10889 Special Table 2015-508345

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polyimide having excellent surface hardness, transparency, and adhesion, and a polyimide film. Another object of the present invention is to provide a polyimide precursor capable of obtaining a polyimide having excellent surface hardness, transparency and adhesion.

The present invention relates to the following items.
1. 1. A polyimide precursor comprising a repeating unit represented by the following chemical formula (1A) and a repeating unit represented by the following chemical formula (2A).

(In the formula, A ₁ or A ₂ is a divalent group having an aromatic ring containing at least one of a hydroxyl group and a carboxyl group.
In the formula, X is a tetravalent group containing no aromatic ring, and R ₁ , R ₂ , R ₃ , and R ₄ are independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 to 9 carbon atoms, respectively. It is an alkylsilyl group. )

2. Item 2. The polyimide precursor according to Item 1, wherein A ₁ and A ₂ are at least one of the following chemical formulas (A-1) and (A-2).

(In the formula, m indicates 0 to 3 and n indicates 0 to _3. Independently, at least one of Y _1, Y ₂ and Y ₃ indicates a hydroxyl group or a carboxyl group, and Q and R are directly independent of each other. Bond, or formula: represents one selected from the group consisting of groups represented by -NHCO-, -CONH-, -COO-, -OCO-, sulfonyl group, ether group, methyl group, isopropylidene group. )

(In the formula, o indicates 0 to 3 and p indicates 0 to 3. Independently, at least one of Y _4, Y ₅ , Y ₆ , Y ₇ , and Y ₈ indicates a hydroxyl group or a carboxyl group, and T, U represents one species independently selected from the group consisting of groups represented by the formulas:> NCO-, -CON <,> N-.)

3. 3. The polyimide precursor according to Item 1 or 2, wherein the repeating unit represented by the chemical formula (1A) is 10 mol% or more based on all the repeating units.

4. The content of the repeating unit represented by the chemical formula (1A) is 10 to 90 mol% with respect to all the repeating units.
The polyimide precursor according to Item 1 or 2, wherein the content of the repeating unit represented by the chemical formula (2A) is 10 to 90 mol% with respect to all the repeating units.

5. A polyimide precursor composition containing the polyimide precursor according to any one of Items 1 to 4.

6. A polyimide comprising a repeating unit represented by the following chemical formula (1) and a repeating unit represented by the following chemical formula (2).

(In the formula, A ₁ or A ₂ is a divalent group having an aromatic ring containing at least one of a hydroxyl group and a carboxyl group.
In the formula, X is a tetravalent group containing no aromatic ring, and R ₁ , R ₂ , R ₃ , and R ₄ are independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 to 9 carbon atoms, respectively. It is an alkylsilyl group. )

7. Item 6. The polyimide according to Item 6, wherein A ₁ and A ₂ have the following chemical formula (A-1).

(In the formula, m indicates 0 to 3 and n indicates 0 to _3. Independently, at least one of Y _1, Y ₂ and Y ₃ indicates a hydroxyl group or a carboxyl group, and Q and R are directly independent of each other. Bond, or formula: represents one selected from the group consisting of groups represented by -NHCO-, -CONH-, -COO-, -OCO-, ether groups, methyl groups, isopropylidene groups.)

(In the formula, o indicates 0 to 3 and p indicates 0 to 3. Independently, at least one of Y _4, Y ₅ , Y ₆ , Y ₇ , and Y ₈ indicates a hydroxyl group or a carboxyl group, and T, U represents one species independently selected from the group consisting of groups represented by the formulas:> NCO-, -CON <,> N-.)

8. Item 6. The polyimide according to Item 6 or Item 7, wherein the repeating unit represented by the chemical formula (1) is 10 mol% with respect to all the repeating units.

9. The content of the repeating unit represented by the chemical formula (1) is 10 to 90 mol% with respect to all the repeating units.
Item 6. The polyimide according to Item 6 or Item 7, wherein the content of the repeating unit represented by the chemical formula (2) is 10 to 90 mol% with respect to all the repeating units.

10. The polyimide obtained from the polyimide precursor according to any one of Items 1 to 4 or the polyimide precursor composition according to Item 5.

11. The polyimide film obtained from the polyimide precursor according to any one of Items 1 to 4 or the polyimide precursor composition according to Item 5.

12. The polyimide resin composition mainly containing the polyimide according to any one of Items 6 to 10.

13. A polyimide film mainly composed of the polyimide according to any one of Items 6 to 10.

14. A polyimide laminate using the polyimide according to any one of items 6 to 10 or the polyimide film according to claim 11 or 13.

15. A polyimide / hard coat laminate comprising the polyimide according to any one of the above items 6 to 10 or the polyimide film according to claim 11 or 13, and a hard coat.

16. A polyimide laminate comprising the polyimide according to any one of the above items 6 to 10, or the polyimide film according to claim 11 or 13, and a polyimide film or glass other than the above.

17. A polyimide / hard coat laminate comprising the polyimide according to any one of the above items 6 to 10 or the polyimide film according to claim 11 or 13, a hard coat, and a polyimide film or glass other than the above.

18. Item 6. The polyimide according to any one of Items 6 to 10, or the polyimide film according to Item 11 or Item 13, the polyimide laminate according to Item 16, or the polyimide / hard coat laminate according to Item 17. A cover sheet for a display surface, characterized in that it contains.

19. Item 6. The polyimide according to any one of Items 6 to 10, or the polyimide film according to Item 11 or Item 13, the polyimide laminate according to Item 16, or the polyimide / hard coat laminate according to Item 17. A substrate for a display, a touch panel, or a solar cell, which comprises.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a polyimide having excellent surface hardness, transparency, and adhesion, and a polyimide film. Further, according to the present invention, it is possible to provide a polyimide precursor capable of obtaining a polyimide having excellent surface hardness, transparency and adhesion.

The polyimide of the present invention and the polyimide obtained from the polyimide precursor of the present invention (hereinafter, may be collectively referred to as "polyimide of the present invention") are excellent in surface hardness, transparency, and adhesion. Further, the polyimide of the present invention usually has a relatively high elastic modulus. Therefore, the film mainly composed of the polyimide of the present invention (polyimide film of the present invention) is suitable, for example, as a cover sheet (protective film) for a display display surface, and as a substrate for a display, a touch panel, or a solar cell. Can be used.

The present invention is a polyimide precursor containing a repeating unit represented by the following chemical formula (1A) and a repeating unit represented by the following chemical formula (2A).

(In the formula, A ₁ or A ₂ is a divalent group having an aromatic ring containing at least one of a hydroxyl group and a carboxyl group.
In the formula, X is a tetravalent group containing no aromatic ring, and R ₁ , R ₂ , R ₃ , and R ₄ are independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 to 9 carbon atoms, respectively. It is an alkylsilyl group. )

The polyimide precursor of the present invention includes a repeating unit represented by the chemical formula (1A) and a repeating unit represented by the chemical formula (2A). However, the polyimide precursor of the present invention may include the repeating unit represented by the chemical formula (1A) and the repeating unit represented by the chemical formula (2A) as a whole, and is represented by the chemical formula (1A). It may contain a polyimide precursor containing only a repeating unit and a polyimide precursor containing only a repeating unit represented by the chemical formula (2A).

The repeating unit represented by the chemical formula (1A) is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 30 mol% or more, based on all the repeating units. It is preferably 50% mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, and particularly preferably 90 mol% or more.

The total content of the repeating unit represented by the chemical formula (1A) and the repeating unit represented by the chemical formula (2A) is preferably 90 to 100 mol%, preferably 95 to 100 mol%, based on all the repeating units. More preferably, it is 100 mol%. In certain embodiments, the polyimide precursor of the present invention is particularly preferably composed of a repeating unit represented by the chemical formula (1A) and a repeating unit represented by the chemical formula (2A).

The polyimide precursor of the present invention has a content of the repeating unit represented by the chemical formula (1A) of 10 to 90 mol% with respect to all the repeating units, and contains the repeating unit represented by the chemical formula (2A). The amount is preferably 10 to 90 mol% with respect to all the repeating units, and the content of the repeating unit represented by the chemical formula (1A) is 30 to 90 mol% with respect to all the repeating units. The content of the repeating unit represented by (2A) is more preferably 10 to 70 mol% with respect to all the repeating units, and the content of the repeating unit represented by the chemical formula (1A) is the total repeating unit. On the other hand, it is 50 to 90 mol%, and the content of the repeating unit represented by the chemical formula (2A) is particularly preferably 10 to 50 mol% with respect to all the repeating units.

Incidentally, the polyimide precursor, also comprise one repeating unit represented by the chemical formula (1A), those containing at least two repeating units represented by the chemical formula A ₁ is different from (1A) may even, also, also comprise one repeating unit represented by the chemical formula (2A), those containing at least two repeating units represented by the chemical formula a ₂ are different (2A) There may be.

A ₁ in the chemical formula (1A) or A ₂ in the chemical formula (2A) is a divalent group having an aromatic ring containing at least one of a hydroxyl group and a carboxyl group.

A ₁ in the chemical formula (1A) or A ₂ in the chemical formula (2A) is preferably a divalent group having an aromatic ring containing at least one of a hydroxyl group and a carboxyl group and having 6 to 40 carbon atoms. , A group represented by at least one of the following chemical formula (A-1) or the following chemical formula (A-2) is particularly preferable.

(In the formula, m indicates 0 to 3 and n indicates 0 to _3. Independently, at least one of Y _1, Y ₂ and Y ₃ indicates a hydroxyl group or a carboxyl group, and Q and R are directly independent of each other. Bond, or formula: represents one selected from the group consisting of groups represented by -NHCO-, -CONH-, -COO-, -OCO-, ether groups, methyl groups, isopropylidene groups.)

(In the formula, o indicates 0 to 3 and p indicates 0 to 3. Independently, at least one of Y _4, Y ₅ , Y ₆ , Y ₇ , and Y ₈ indicates a hydroxyl group or a carboxyl group, and T, U represents one species independently selected from the group consisting of groups represented by the formulas:> NCO-, -CON <,> N-.)

A ₁ is a repeating unit of the chemical formula (1A) which is a group represented by the chemical formula (A-1) or (A-2), and A ₂ is the chemical formula (A-1) or (A-2). The diamine component that gives the repeating unit of the chemical formula (2A), which is the group represented, is not particularly limited, but is, for example, 3,3'-dihydroxybenzidine, 2,2'-dihydroxybenzidine, 2, 3'-Dihydroxybenzidine, 2,5-diaminophenol, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 3,4-diaminobenzoic acid, 3,3''-diamino-4,4'' −Dihydroxydiphenylsulfone, 1,2-bis (4-amino-2-carboxyphenoxy) benzene, 1,3-bis (4-amino-2-carboxyphenoxy) benzene, 3,5-bis (4-aminophenoxy) Benzoic acid, 4,4''-diamino-N- (4-carboxyphenoxy) benzanilide, N-bis (4-aminophenoxy) -4-carboxyaniline, 5-amino-2- (4-aminophenoxy) benzoic acid , 4,4''-diamino-4''''-hydroxytriphenylamine, 3,5-diamino-4-methoxybenzoic acid, 1,3-bis (4-amino-3-hydroxyphenoxy) benzene, 5 , 5'-methylenebis (2-aminobenzoic acid), 2,2'-bis (3-amino-4-hydroxyphenyl) propane, bis (3-amino-4-hydroxyphenyl) sulfone, 4,4'-bis Examples thereof include (4-aminobenzamide) -3,3'-dihydroxybiphenyl, which may be used alone or in combination of a plurality of types. Of these, 3,3'-dihydroxybenzidine is preferable.

In the group represented by the chemical formula (A-1), the linking position between the aromatic rings is not particularly limited, but it is preferable to bond at the 4-position with respect to the linking group between the aromatic rings.

Further, A ₁ in the chemical formula (1A) and A ₂ in the chemical formula (2A) are groups represented by the chemical formula (A-1) in which m and n are 0, or m and / or. The group represented by the chemical formula (A-1) in which n is 1 to 3 and Q and R are directly bonded is more preferable, and the group represented by the following chemical formula (D-1) is particularly preferable.

Incidentally, the repeating units, and the formula A ₂ is a group represented by the formula (D-1) of the formula is a group A ₁ is represented by the formula (D-1) (1A) (2A The diamine component that gives the repeating unit of) is 3,3'-dihydroxybenzidine.

The diamine component that gives the chemical formula (1A) or the repeating unit of the chemical formula (2A) is other than the diamine component that gives A ₁ or A ₂ having the structure of the chemical formula (A-1) or (A-2). , Other aromatic diamines can be used. Other diamine components include, for example, 2,2'-dimethyl-4,4'-diaminobiphenyl (m-trizine), p-phenylenediamine, m-phenylenediamine, benzidine, 3,3'-diamino-biphenyl, 2,2'-bis (trifluoromethyl) benzidine, 3,3'-bis (trifluoromethyl) benzidine, 4,4'-diaminobenzanilide, 3,4'-diaminobenzanilide, N, N'-bis (4-Aminophenyl) terephthalamide, N, N'-p-phenylenebis (p-aminobenzamide), 4-aminophenoxy-4-diaminobenzoate, bis (4-aminophenyl) terephthalate, biphenyl-4,4' -Dicarboxylic acid bis (4-aminophenyl) ester, p-phenylene bis (p-aminobenzoate), bis (4-aminophenyl)-[1,1'-biphenyl] -4,4'-dicarboxylate, [ 1,1'-biphenyl] -4,4'-diylbis (4-aminobenzoate), 4,4'-oxydianiline, 3,4'-oxydianiline, 3,3'-oxydianiline, p − Methylenebis (phenylenediamine), 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4' -Bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis ( 4-aminophenyl) hexafluoropropane, bis (4-aminophenyl) sulfone, 3,3'-bis (trifluoromethyl) benzidine, 3,3'-bis ((aminophenoxy) phenyl) propane, 2,2' -Bis (3-amino-4-hydroxyphenyl) hexafluoropropane, bis (4- (4-aminophenoxy) diphenyl) sulfone, bis (4- (3-aminophenoxy) diphenyl) sulfone, octafluorobenzidine, 3, 3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 6,6'-bis ( 3-Aminophenoxy) -3,3,3', 3'-Tetramethyl-1,1'-Spirobiindan, 6,6'-Bis (4-Aminophenoxy) -3,3,3', 3'-Te Examples thereof include tramethyl-1,1'-spirobiindane and derivatives thereof, which may be used alone or in combination of a plurality of types. Of these, 4,4'-oxydianiline, 3,4'-oxydianiline, 3,3'-oxydianiline, p-methylenebis (phenylenediamine), 1,3-bis (4-aminophenoxy) Benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3) -Aminophenoxy) Biphenyl 2,2'-dimethyl-4,4'-diaminobiphenyl (m-trizine), p-phenylenediamine are preferable, and 2,2'-dimethyl-4,4'-diaminobiphenyl (m-) is particularly preferable. Trizine) is preferred.

A ₁ is the formula (A-1) and the repeating unit represented by Formula is a group (1A) represented by, A ₂ is Formula Formula is a group represented by (A-1) ( The total content of the repeating units represented by 2A) is preferably 70 to 100 mol%, more preferably 80 to 100 mol%, and 90 to 100 mol% with respect to all the repeating units. It is particularly preferable to have.

The repeating unit represented by the chemical formula (1A) in which A ₁ is a group represented by the chemical formula (D-1) and the chemical formula (A ₂ ) being a group represented by the chemical formula (D-1). The total content of the repeating units represented by 2A) is preferably 10 to 100 mol%, more preferably 20 to 100 mol%, and 30 to 100 mol% with respect to all the repeating units. It is more preferably 50 to 100 mol%, more preferably 70 to 100 mol%, more preferably 80 to 100 mol%, and 90 to 100 mol%. Is particularly preferable.

The polyimide precursor of the present invention is represented by A ₁ is the formula (A-1) a group represented by (preferably the formula (D-1) a group represented by) a Formula (1A) The content of the repeating unit is 10 to 90 mol% with respect to all the repeating units, and A ₂ is a group represented by the chemical formula (A-1) (preferably a group represented by the chemical formula (D-1)). The content of the repeating unit represented by the chemical formula (2A) is preferably 10 to 90 mol% with respect to all the repeating units, and A ₁ is a group represented by the chemical formula (A-1). The content of the repeating unit represented by the chemical formula (1A), which is (preferably the group represented by the chemical formula (D-1)), is 30 to 90 mol% with respect to all the repeating units, and A ₂ is The content of the repeating unit represented by the chemical formula (2A), which is the group represented by the chemical formula (A-1) (preferably the group represented by the chemical formula (D-1)), is based on the total repeating unit. It is more preferably 10 to 70 mol%, and A ₁ is the group represented by the chemical formula (A-1) (preferably the group represented by the chemical formula (D-1)). The content of the repeating unit represented by) is 50 to 90 mol% with respect to all the repeating units, and A ₂ is a group represented by the chemical formula (A-1) (preferably the chemical formula (D-1)). It is particularly preferable that the content of the repeating unit represented by the chemical formula (2A), which is the group represented by (2A), is 10 to 50 mol% with respect to all the repeating units.

A ₁ is the formula of the repeating units, and the formula A ₂ is a group represented by the formula (A-1) of the formula a group represented by (A-1) (1A) (2A) The other diamine component that gives the repeating unit is not particularly limited, but is, for example, 3,3'-dihydroxybenzidine, 2,2'-dihydroxybenzidine, 2,3'-dihydroxybenzidine, 2,5-diamino. Examples thereof include phenol, etc., which may be used alone, or may be used in combination of a plurality of types. Of these, 3,3'-dihydroxybenzidine is more preferred.

The tetracarboxylic acid component giving the repeating unit represented by the chemical formula (1A) includes 1,2,3,4-cyclobutanetetracarboxylic acids and the like (tetracarboxylic acids and the like are tetracarboxylic acid and tetracarboxylic acid dianhydride. , Tetracarboxylic acid silyl ester, tetracarboxylic acid ester, tetracarboxylic acid chloride and other tetracarboxylic acid derivatives), and the tetracarboxylic acid component that gives the repeating unit represented by the chemical formula (2A) has an aromatic ring. It is a tetravalent group that is not included.

As the tetracarboxylic acid component that gives the repeating unit represented by the chemical formula (1A), one type such as 1,2,3,4-cyclobutanetetracarboxylic acids may be used alone, or a plurality of types may be used. It can also be used in combination.

The tetracarboxylic acid component that gives the repeating unit represented by the chemical formula (2A) is shown below.

The tetracarboxylic acid component that gives the repeating unit represented by the chemical formula (2A) is not particularly limited as long as it is a tetravalent group that does not contain an aromatic ring, and is, for example, cyclohexane-1,2,4,5-. Tetracarboxylic acid, [1,1'-bi (cyclohexane)]-3,3', 4,4'-tetracarboxylic acid, [1,1'-bi (cyclohexane)]-2,3,3', 4 '-Tetracarboxylic acid, [1,1'-bi (cyclohexane)]-2,2', 3,3'-tetracarboxylic acid, 4,4'-methylenebis (cyclohexane-1,2-dicarboxylic acid), 4 , 4'-(Propane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), 4,4'-oxybis (cyclohexane-1,2-dicarboxylic acid), 4,4'-thiobis (cyclohexane) -1,2-dicarboxylic acid), 4,4'-sulfonylbis (cyclohexane-1,2-dicarboxylic acid), 4,4'-(dimethylsilanediyl) bis (cyclohexane-1,2-dicarboxylic acid), 4 , 4'-(Tetrafluoropropane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), octahydropentalene-1,3,4,6-tetracarboxylic acid, bicyclo [2.2. 1] Heptane-2,3,5,6-tetracarboxylic acid, 6- (carboxymethyl) bicyclo [2.2.1] heptane-2,3,5-tricarboxylic acid, bicyclo [2.2.2] octane -2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octa-5-ene-2,3,7,8-tetracarboxylic acid, tricyclo [4.2.2.02, 5] ] Decane-3,4,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] Deca-7-en-3,4,9,10-tetracarboxylic acid, 9-oxatricyclo [4.2.1.02,5] Nonan-3,4,7,8-tetracarboxylic acid, norbornan-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornan-5, Derivatives such as 5'', 6,6''-tetracarboxylic acid, decahydro-1,4: 5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic acid and their acid dianhydrides Can be used alone, or a plurality of types can be used in combination. Of these, cyclohexane-1,2,4,5-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6 '' -Tetracarboxylic acid, decahydro-1,4: 5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic acid is preferred, norbornane-2-spiro-α-cyclopentanone-α'- Spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid is particularly preferred. These tetracarboxylic acids may be used alone or in combination of two or more.

The tetracarboxylic dian component giving the repeating unit represented by the chemical formula (2A) is preferably norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', One type such as 6,6''-tetracarboxylic acids may be used alone, or a plurality of types may be used in combination. Norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acids and the like include trans-endo-endo-norbornane- 2-Spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acids and / or cis-endo-endo-norbornane-2- Spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acids and the like are more preferable.

The polyimide precursor of the present invention may contain one or more of other repeating units other than the repeating unit represented by the chemical formula (1A) or the chemical formula (2A).

Other aromatic or aliphatic tetracarboxylic acids can be used as the tetracarboxylic acid component that gives the other repeating unit. For example, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 4- (2,5-dioxo tetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2 -Dicarboxylic acid, pyromellitic acid, 3,3', 4,4'-benzophenone tetracarboxylic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4'-biphenyltetra Carboxylic acid, 4,4'-oxydiphthalic acid, bis (3,4-dicarboxyphenyl) sulfone dianhydride, m-terphenyl-3,4,3', 4'-tetracarboxylic acid dianhydride, p- Tarphenyl-3,4,3', 4'-tetracarboxylic acid dianhydride, biscarboxyphenyldimethylsilane, bisdicarboxyphenoxydiphenylsulfide, sulfonyldiphthalic acid, isopropyridenediphenoxybisphthalic acid, cyclohexane-1, 2,4,5-Tetracarboxylic acid, [1,1'-bi (cyclohexane)]-3,3', 4,4'-tetracarboxylic acid, [1,1'-bi (cyclohexane)]-2, 3,3', 4'-tetracarboxylic acid, [1,1'-bi (cyclohexane)]-2,2', 3,3'-tetracarboxylic acid, 4,4'-methylenebis (cyclohexane-1,2) -Dicarboxylic acid), 4,4'-(propane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), 4,4'-oxybis (cyclohexane-1,2-dicarboxylic acid), 4, 4'-thiobis (cyclohexane-1,2-dicarboxylic acid), 4,4'-sulfonylbis (cyclohexane-1,2-dicarboxylic acid), 4,4'-(dimethylsilanediyl) bis (cyclohexane-1,2) -Dicarboxylic acid), 4,4'-(tetrafluoropropane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), octahydropentalene-1,3,4,6-tetracarboxylic acid, Bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid, 6- (carboxymethyl) bicyclo [2.2.1] heptane-2,3,5-tricarboxylic acid, bicyclo [2] .2.2] Octane-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octa-5-ene-2,3,7,8-tetracarboxylic acid, tricyclo [4.2] .2.02,5] Decane-3,4,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] Deca-7-ene-3,4,9,10-tetra Carboxylic acid, 9-oxatricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid, decahydro-1,4: 5,8-dimethanonaphthalene-2,3 , 6,7-Tetracarboxylic acid and other derivatives and their acid dianhydrides can be mentioned and may be used alone or in combination of two or more. These tetracarboxylic acids may be used alone or in combination of two or more.

When the diamine component to be combined is an aliphatic diamine, derivatives such as 1,2,3,4-cyclobutanetetracarboxylic acid and an aromatic dianhydride containing no aromatic ring are used as tetracarboxylic acid components that give other repeating units. Alternatively, these acid dianhydrides can also be used.

As the diamine component giving another repeating unit, A ₁ is the repeating unit of the chemical formula (1A) which is a group represented by the chemical formula (A-1) or (A-2), and A ₂ is the chemical formula (A). It may be a diamine exemplified as a diamine component that gives a repeating unit of the chemical formula (2A) which is a group represented by -1) or (A-2).

Other aromatic or aliphatic diamines can be used as the diamine component that gives the other repeating unit. For example, 2,2'-dimethyl-4,4'-diaminobiphenyl (m-tridine), p-phenylenediamine, m-phenylenediamine, benzidine, 3,3'-diamino-biphenyl, 2,2'-bis ( Trifluoromethyl) benzidine, 3,3'-bis (trifluoromethyl) benzidine, 4,4'-diaminobenzanilide, 3,4'-diaminobenzanilide, N, N'-bis (4-aminophenyl) terephthal Amid, N, N'-p-phenylenebis (p-aminobenzamide), 4-aminophenoxy-4-diaminobenzoate, bis (4-aminophenyl) terephthalate, biphenyl-4,4'-dicarboxylic acid bis (4-) Aminophenyl) ester, p-phenylene bis (p-aminobenzoate), bis (4-aminophenyl)-[1,1'-biphenyl] -4,4'-dicarboxylate, [1,1'-biphenyl] -4,4'-diylbis (4-aminobenzoate), 4,4'-oxydianiline, 3,4'-oxydianiline, 3,3'-oxydianiline, p-methylenebis (phenylenediamine), 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) ) Biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoro Propane, bis (4-aminophenyl) sulfone, 3,3'-bis (trifluoromethyl) benzidine, 3,3'-bis ((aminophenoxy) phenyl) propane, 2,2'-bis (3-amino-) 4-Hydroxyphenyl) hexafluoropropane, bis (4- (4-aminophenoxy) diphenyl) sulfone, bis (4- (3-aminophenoxy) diphenyl) sulfone, octafluorobenzidine, 3,3'-dimethoxy-4, 4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 1,4-diaminocyclohexane, 1,4-diamino -2-Methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propylcyclohexane, 1,4-diamino-2 -Isopropylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino-2-sec-butylcyclohexane, 1,4-diamino-2-tert -Butylcyclohexane, 1,2-diaminocyclohexane, 1,3-diaminocyclobutane, 1,4-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane, diaminobicycloheptane, diaminomethylbicycloheptane , Diaminooxybicycloheptan, diaminomethyloxybicycloheptane, isophoronediamine, diaminotricyclodecane, diaminomethyltricyclodecane, bis (aminocyclohexane) methane, bis (aminocyclohexyl) isopropylidene 6,6'-bis (3) -Aminophenoxy) -3,3,3', 3'-Tetramethyl-1,1'-Spirovinedan, 6,6'-Bis (4-Aminophenoxy) -3,3,3', 3'-Tetramethyl Examples thereof include -1,1'-spirobiindane and derivatives thereof, which may be used alone or in combination of a plurality of types.

However, in the chemical formula (1A), the acid group at the 1-position of the cyclobutane ring reacts with the amino group to form an amide bond (-CONH-), and the acid group at the 2-position does not form an amide bond. Assuming that the group is represented by -COOR ₁ , one of the acid groups at the 3- or 4-position reacts with the amino group to form an amide bond (-CONH-), and the other forms an amide bond. Not-indicates that it is a group represented by COOR ₂ . That is, the chemical formula (1A) contains two structural isomers.

In the polyimide precursor of the present invention, R ₁ and R ₂ of the chemical formula (1A) and R ₃ and R ₄ of the chemical formula (2A) are independently hydrogen, having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms, respectively. It is either an alkyl group of 3 to 9 or an alkylsilyl group having 3 to 9 carbon atoms. The types of functional groups of R ₁ and R ₂ , R ₃ and R ₄ and the introduction rate of functional groups can be changed by the production method described later.

When R ₁ and R ₂ , R ₃ and R ₄ are hydrogen, the production of polyimide tends to be easy.

Further, when R ₁ and R ₂ , R ₃ and R ₄ are alkyl groups having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms, the storage stability of the polyimide precursor tends to be excellent. In this case, it is more preferable that R ₁ and R ₂ , R ₃ and R ₄ are methyl groups or ethyl groups.

Further, when R ₁ and R ₂ , R ₃ and R ₄ are alkylsilyl groups having 3 to 9 carbon atoms, the solubility of the polyimide precursor tends to be excellent. In this case, R ₁ and R ₂ , R ₃ and R ₄ are more preferably trimethylsilyl groups or t-butyldimethylsilyl groups.

The introduction rate of the functional group is not particularly limited, but when an alkyl group or an alkylsilyl group is introduced, R ₁ and R ₂ , R ₃ and R ₄ are 25% or more, preferably 50% or more, more preferably, respectively. 75% or more can be an alkyl group or an alkylsilyl group.

Polyimide precursors of the present invention, the chemical _{structure R 1} and _R 2, _{R 3} and _{R 4} take, 1) a polyamic acid _{(R 1} and _R 2, _{R 3} and _{R 4} is hydrogen), 2) a polyamic acid ester (At least part of R ₁ and R ₂ , R ₃ and R ₄ are alkyl groups) 3) 4) Polyamic acid silyl ester (at least part of R ₁ and R ₂ , R ₃ and R ₄ are alkyl silyl groups) Can be classified into. The polyimide precursor of the present invention can be easily produced by the following production methods for each of these categories. However, the method for producing the polyimide precursor of the present invention is not limited to the following production method.

1) Polyimide The polyimide precursor of the present invention contains approximately equimolar tetracarboxylic dianhydride as a tetracarboxylic dian component and a diamine component in a solvent, preferably the molar ratio of the diamine component to the tetracarboxylic acid component [diamine]. The number of moles of the component / the number of moles of the tetracarboxylic acid component] is preferably at a ratio of 0.99 to 1.10, more preferably 0.95 to 1.05, for example, imidization at a relatively low temperature of 120 ° C. or lower. By reacting while suppressing the above, a polyimide precursor solution composition can be suitably obtained.

More specifically, but not limited to, diamine is dissolved in an organic solvent, tetracarboxylic dianhydride is gradually added to the solution with stirring, and the temperature is 0 to 120 ° C., preferably 5 to 80. A polyimide precursor can be obtained by stirring in the temperature range of 1 to 72 hours. When the reaction is carried out at 80 ° C. or higher, the molecular weight fluctuates depending on the temperature history at the time of polymerization, and imidization proceeds due to heat, so that the polyimide precursor may not be stably produced. The order of adding diamine and tetracarboxylic dianhydride in the above production method is preferable because the molecular weight of the polyimide precursor tends to increase. It is also possible to reverse the order of addition of the diamine and the tetracarboxylic dianhydride in the above production method, which is preferable because the precipitates are reduced.

When the molar ratio of the tetracarboxylic acid component to the diamine component is excessive, a carboxylic acid derivative in an amount substantially corresponding to the excess molar number of the diamine component is added as necessary, and the tetracarboxylic acid component and the diamine are added. The molar ratio of the components can be brought close to the equivalent amount. The carboxylic acid derivative here is a tetracarboxylic acid that does not substantially increase the viscosity of the polyimide precursor solution, that is, does not substantially participate in the extension of the molecular chain, or a tricarboxylic acid and its anhydride that function as a terminal terminator. Dicarboxylic acids and their anhydrides are suitable.

2) Polyamic acid ester Tetracarboxylic acid dianhydride is reacted with an arbitrary alcohol to obtain a diester dicarboxylic acid, which is then reacted with a chlorinating reagent (thionyl chloride, oxalyl chloride, etc.) to obtain a diester dicarboxylic acid chloride. A polyimide precursor can be obtained by stirring the diester dicarboxylic acid chloride and diamine at −20 to 120 ° C., preferably −5 to 80 ° C. for 1 to 72 hours. When the reaction is carried out at 80 ° C. or higher, the molecular weight fluctuates depending on the temperature history at the time of polymerization, and imidization proceeds due to heat, so that the polyimide precursor may not be stably produced. A polyimide precursor can also be easily obtained by dehydrating and condensing a diesterdicarboxylic acid and a diamine using a phosphorus-based condensing agent, a carbodiimide condensing agent, or the like.

Since the polyimide precursor obtained by this method is stable, purification such as reprecipitation can be performed by adding a solvent such as water or alcohol.

3) Polyamic acid silyl ester (indirect method)
A diamine is reacted with a silylating agent in advance to obtain a silylated diamine. If necessary, the silylated diamine is purified by distillation or the like. Then, the silylated diamine is dissolved in the dehydrated solvent, and the tetracarboxylic dianhydride is gradually added while stirring, and the temperature is in the range of 0 to 120 ° C, preferably 5 to 80 ° C. A polyimide precursor can be obtained by stirring for ~ 72 hours. When the reaction is carried out at 80 ° C. or higher, the molecular weight fluctuates depending on the temperature history at the time of polymerization, and imidization proceeds due to heat, so that the polyimide precursor may not be stably produced.

As the silylating agent used here, it is preferable to use a silylating agent that does not contain chlorine because it is not necessary to purify the silylated diamine. Examples of the silylating agent containing no chlorine atom include N, O-bis (trimethylsilyl) trifluoroacetamide, N, O-bis (trimethylsilyl) acetamide, and hexamethyldisilazane. N, O-bis (trimethylsilyl) acetamide and hexamethyldisilazane are particularly preferable because they do not contain a fluorine atom and are low in cost.

Further, in the silylation reaction of diamine, an amine-based catalyst such as pyridine, piperidine, or triethylamine can be used to promote the reaction. This catalyst can be used as it is as a polymerization catalyst for the polyimide precursor.

4) Polyamic acid silyl ester (direct method)
A polyimide precursor is obtained by mixing the polyamic acid solution obtained by the method 1) with a silylating agent and stirring in the range of 0 to 120 ° C., preferably 5 to 80 ° C. for 1 to 72 hours. When the reaction is carried out at 80 ° C. or higher, the molecular weight fluctuates depending on the temperature history at the time of polymerization, and imidization proceeds due to heat, so that the polyimide precursor may not be stably produced.

As the silylating agent used here, it is preferable to use a silylating agent that does not contain chlorine because it is not necessary to purify the silylated polyamic acid or the obtained polyimide. Examples of the silylating agent containing no chlorine atom include N, O-bis (trimethylsilyl) trifluoroacetamide, N, O-bis (trimethylsilyl) acetamide, and hexamethyldisilazane. N, O-bis (trimethylsilyl) acetamide and hexamethyldisilazane are particularly preferable because they do not contain a fluorine atom and are low in cost.

Since any of the above-mentioned production methods can be preferably carried out in an organic solvent, as a result, a solution or a solution composition containing a polyimide precursor can be easily obtained.

Solvents used in preparing the polyimide precursor are, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide. An aprotic solvent such as N, N-dimethylacetamide is preferable, but any kind of solvent can be used without any problem as long as the raw material monomer component and the generated polyimide precursor are dissolved. It is not limited to its structure. As the solvent, an amide solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α- Cyclic ester solvents such as methyl-γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, glycol solvents such as triethylene glycol, phenols such as m-cresol, p-cresol, 3-chlorophenol and 4-chlorophenol. System solvents, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide and the like are preferably used. In addition, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methylcellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, tetrahydrofuran. , Dimethoxyethane, diethoxyethane, dibutyl ether, diethylene glycol dimethyl ether, methylisobutylketone, diisobutylketone, cyclopentanone, cyclohexanone, methylethylketone, acetone, butanol, ethanol, xylene, toluene, chlorbenzene, turpen, mineral spirit, petroleum A naphtha-based solvent or the like can also be used. In addition, a plurality of kinds of solvents can be used in combination.

The logarithmic viscosity of the polyimide precursor is not particularly limited, but the logarithmic viscosity of the N, N-dimethylacetamide solution at a concentration of 0.5 g / dL at 30 ° C. is 0.2 dL / g or more, more preferably 0.3 dL / g. Above, it is particularly preferable that it is 0.4 dL / g or more. When the logarithmic viscosity is 0.2 dL / g or more, the molecular weight of the polyimide precursor is high, and the mechanical strength and heat resistance of the obtained polyimide are excellent.

The polyimide precursor composition of the present invention usually contains a polyimide precursor and a solvent. The solvent used in the polyimide precursor composition of the present invention has no problem as long as the polyimide precursor is dissolved, and its structure is not particularly limited. As the solvent, an amide solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone , Cyclic ester solvents such as α-methyl-γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, glycol solvents such as triethylene glycol, m-cresol, p-cresol, 3-chlorophenol, 4-chlorophenol. Such as phenolic solvent, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide and the like are preferably adopted. In addition, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methylcellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, tetrahydrofuran. , Dimethoxyethane, diethoxyethane, dibutyl ether, diethylene glycol dimethyl ether, methylisobutylketone, diisobutylketone, cyclopentanone, cyclohexanone, methylethylketone, acetone, butanol, ethanol, xylene, toluene, chlorbenzene, turpen, mineral spirit, petroleum A naphtha-based solvent or the like can also be used. In addition, a plurality of types of these can be used in combination. As the solvent of the polyimide precursor composition, the solvent used when preparing the polyimide precursor can be used as it is.

In the polyimide precursor composition of the present invention, the total amount of the tetracarboxylic acid component and the diamine component is 5% by mass or more, preferably 10% by mass, based on the total amount of the solvent, the tetracarboxylic acid component and the diamine component. As mentioned above, the ratio is more preferably 15% by mass or more. Normally, the total amount of the tetracarboxylic acid component and the diamine component is 60% by mass or less, preferably 50% by mass or less, based on the total amount of the solvent, the tetracarboxylic acid component and the diamine component. Suitable. This concentration is a concentration that is approximately close to the solid content concentration due to the polyimide precursor, but if this concentration is too low, it becomes difficult to control the thickness of the polyimide film obtained, for example, when producing a polyimide film. Sometimes.

The viscosity (rotational viscosity) of the polyimide precursor composition is not particularly limited, but the rotational viscosity measured using an E-type rotational viscometer at a temperature of 25 ° C. and a shear rate of 20 sec ^-1 is 0.01 to 1000 Pa · sec. Preferably, 0.1 to 100 Pa · sec is more preferable. In addition, thixotropic properties can be imparted as needed. When the viscosity is in the above range, it is easy to handle when coating or forming a film, repelling is suppressed, and the leveling property is excellent, so that a good film can be obtained.

The polyimide precursor composition of the present invention can be used as an imidization promoting catalyst (imidazole-based compound, etc.), a chemical imidizing agent (acid anhydride such as acetic anhydride, an amine compound such as pyridine, isoquinolin), and oxidation, if necessary. Inhibitors, fillers (inorganic particles such as silica), dyes, pigments, coupling agents such as silane coupling agents, primers, flame retardant materials, antifoaming agents, leveling agents, polyimide control agents (fluid aids), peeling It can contain agents and the like.

The polyimide precursor composition of the present invention may preferably contain an imidazole-based compound and / or a trialkylamine compound. The total content of the imidazole compound and / or the trialkylamine compound is preferably less than 4 mol per 1 mol of the repeating unit of the polyimide precursor. In the case of polyimide, which requires transparency, the use of additives that can cause coloring is not preferred. However, the imidazole compound and / or the trialkylamine compound is preferably added in an amount of less than 4 mol, more preferably 0.05 mol or more and 1 mol or less, based on 1 mol of the repeating unit of the polyimide precursor. By adding to the composition, it may be possible to improve the mechanical properties of the obtained polyimide film while maintaining high transparency. That is, a polyimide having more excellent mechanical properties may be obtained from a polyimide precursor having the same composition while maintaining high transparency.

The imidazole-based compound used in the present invention is not particularly limited as long as it is a compound having an imidazole skeleton.

In certain embodiments, the imidazole-based compound preferably has a boiling point of less than 340 ° C., preferably 330 ° C. or lower, more preferably 300 ° C. or lower, and particularly preferably 270 ° C. or lower at 1 atm.

The imidazole compound used in the present invention is not particularly limited, and examples thereof include 1,2-dimethylimidazole, 1-methylimidazole, 2-methylimidazole, 2-phenylimidazole, imidazole, and benzimidazole. 1,2-dimethylimidazole (boiling point at 1 atm: 205 ° C), 1-methylimidazole (boiling point at 1 atm: 198 ° C), 2-methylimidazole (boiling point at 1 atm: 268 ° C), imidazole (boiling point at 1 atm) : 256 ° C.), and 1,2-dimethylimidazole and 1-methylimidazole are particularly preferable. As the imidazole compound, one type may be used alone, or a plurality of types may be used in combination.

The trialkylamine compound used in the present invention is not particularly limited, but a compound having an alkyl group having 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms is preferable, and trimethylamine, triethylamine, and tri-n-propyl are preferable. Examples include amines and tributylamines. As the trialkylamine compound, one type may be used alone, or a plurality of types may be used in combination. In addition, one or more imidazole compounds and one or more trialkylamine compounds can be used in combination.

When an imidazole compound and / or a trialkylamine compound is used, the content of the imidazole compound and / or the trialkylamine compound in the polyimide precursor composition is less than 4 mol per 1 mol of the repeating unit of the polyimide precursor. It is preferable to have. When the content of the imidazole compound and / or the trialkylamine compound is 4 mol or more with respect to 1 mol of the repeating unit of the polyimide precursor, the storage stability of the polyimide precursor composition deteriorates. The content of the imidazole compound and / or the trialkylamine compound is preferably 0.05 mol or more with respect to 1 mol of the repeating unit of the polyimide precursor, and is preferably 0.05 mol or more with respect to 1 mol of the repeating unit of the polyimide precursor. It is more preferably 2 mol or less, and particularly preferably 1 mol or less. Here, 1 mol of the repeating unit of the polyimide precursor corresponds to 1 mol of the tetracarboxylic acid component.

The polyimide precursor composition containing the imidazole-based compound and / or the trialkylamine compound shall be prepared by adding the imidazole-based compound and / or the trialkylamine compound to the polyimide precursor solution or solution composition obtained by the above-mentioned production method. Can be done. Further, a tetracarboxylic acid component (tetracarboxylic dianhydride, etc.), a diamine component, an imidazole compound and / or a trialkylamine compound are added to the solvent, and the tetra is added in the presence of the imidazole compound and / or the trialkylamine compound. A polyimide precursor composition containing a polyimide precursor and an imidazole-based compound and / or a trialkylamine compound can also be obtained by reacting a carboxylic acid component with a diamine component.

The polyimide of the present invention contains a repeating unit represented by the chemical formula (1) and a repeating unit represented by the chemical formula (2). In other words, the polyimide of the present invention is obtained from the polyimide precursor of the present invention, and more specifically, the polyimide precursor composition containing the polyimide precursor of the present invention is obtained by heating or the like. Is.

The polyimide of the present invention can be obtained by imidizing the polyimide precursor of the present invention as described above (that is, dehydrating and ring-closing the polyimide precursor). The imidization method is not particularly limited, and a known thermal imidization or chemical imidization method can be preferably applied. Suitable examples of the form of the obtained polyimide include a film, a laminate of a polyimide film and another base material, a coating film, a powder, beads, a molded body, and a foam.

The polyimide of the present invention is obtained by using the above-mentioned tetracarboxylic dian component and diamine component used for obtaining the polyimide precursor of the present invention, and the preferable tetracarboxylic dian component and diamine component are also described above. It is the same as the polyimide precursor of the present invention.

The thickness of the film made of the polyimide (polyimide of the present invention) obtained from the polyimide precursor of the present invention depends on the application, but is usually preferably 5 to 200 μm, more preferably 10 to 150 μm. When the polyimide film is used for light transmission applications such as display applications, if the polyimide film is too thick, the light transmittance may decrease, and if it is too thin, the breaking point load etc. decreases and it is preferably used as a film. May not be possible.

In particular, when the polyimide film is used for light transmission applications such as display applications, it is desirable that the polyimide film has high transparency. The polyimide obtained from the polyimide precursor of the present invention (polyimide of the present invention) is not particularly limited, but the total light transmittance when formed into a film is preferably 80% or more, more preferably 82% or more, still more preferably. 84% or more, more preferably 85% or more, particularly preferably 86% or more.

The polyimide obtained from the polyimide precursor of the present invention (polyimide of the present invention) is not particularly limited, but the haze when formed into a film is preferably 3% or less, more preferably 2% or less, still more preferable. Is 1.5% or less, particularly preferably less than 1%. For example, when used for display applications, if the haze is higher than 3%, light may be scattered and the image may be blurred.

The polyimide obtained from the polyimide precursor of the present invention (polyimide of the present invention) is not particularly limited, but the tensile elastic modulus when formed into a film is preferably 4 GPa or more, more preferably 4.5 GPa or more, and more preferably. Is 5 GPa or more, more preferably 5.3 GPa or more, further preferably 5.5 GPa or more, and particularly preferably 6.0 GPa or more.

The polyimide obtained from the polyimide precursor of the present invention (polyimide of the present invention) is not particularly limited, but the breaking point load when formed into a film is preferably 10 N or more, more preferably 15 N or more. If the breaking point load is low, it may easily crack when bent.

The polyimide obtained from the polyimide precursor of the present invention (polyimide of the present invention) is not particularly limited, but the elongation at break point when formed into a film is preferably 3% or more, more preferably 5% or more. ..

The polyimide obtained from the polyimide precursor of the present invention (polyimide of the present invention) is not particularly limited, but the 5% weight loss temperature, which is an index of heat resistance of the polyimide film, is preferably 375 ° C. or higher, more preferably 380 ° C. or higher. Above, more preferably 385 ° C. or higher, particularly preferably 400 ° C. or higher.

The polyimide obtained from the polyimide precursor of the present invention (polyimide of the present invention) is not particularly limited, but the pencil hardness on the surface of the polyimide film is preferably B or higher, more preferably HB or higher, still more preferably F or higher, particularly preferably. Is greater than or equal to H. When the pencil hardness on the surface of the polyimide film is high, the polyimide film itself is less likely to be scratched, and in the polyimide / hard coat laminate, the higher the polyimide pencil hardness, the higher the pencil hardness of the hard coat of the laminate.

The laminate composed of the polyimide (polyimide of the present invention) obtained from the polyimide precursor of the present invention and the hard coat layer is not particularly limited, but it is preferable that the adhesion between the polyimide and the hard coat is high. The cross-cut test result is preferably 1B or more, more preferably 2B or more, more preferably 3B or more, still more preferably 4B or more, and particularly preferably 5B. If the adhesion between the polyimide and the hard coat is low, it may peel off when bent.

The laminate composed of the polyimide (polyimide of the present invention) obtained from the polyimide precursor of the present invention and the hard coat layer is not particularly limited, but the total light transmittance is preferably 75% or more, more preferably 80% or more. , More preferably 82% or more, further preferably 84% or more, still more preferably 85% or more, and particularly preferably 86% or more.

The laminate composed of the polyimide (polyimide of the present invention) obtained from the polyimide precursor of the present invention and the hard coat layer is not particularly limited, but has a pencil hardness of H or more, more preferably 2H or more, still more preferably 3H or more, and further. It is preferably 4H or more, and particularly preferably 5H or more.

The laminate composed of the polyimide (polyimide of the present invention) obtained from the polyimide precursor of the present invention and the hard coat layer is not particularly limited, but the haze is preferably 3% or less, more preferably 2% or less. It is more preferably 1.5% or less, and particularly preferably less than 1%. For example, when used for display applications, if the haze is higher than 3%, light may be scattered and the image may be blurred.

The polyimide obtained from the polyimide precursor of the present invention (polyimide of the present invention) has high transparency, excellent mechanical properties such as tensile elastic modulus and breaking point stress, and has a low linear thermal expansion coefficient. Since it has excellent heat resistance, it can be suitably used, for example, in applications such as a cover sheet (protective film) for a display display surface, and in applications such as a transparent substrate for a display, a transparent substrate for a touch panel, or a substrate for a solar cell. it can.

Hereinafter, an example of a polyimide film / base material laminate or a method for producing a polyimide film using the polyimide precursor of the present invention will be described. However, the method is not limited to the following.

For example, a composition containing the polyimide precursor of the present invention in a substrate such as ceramic (glass (particularly alkali-free glass), silicon, alumina, etc.), metal (copper, aluminum, stainless steel, etc.), heat-resistant plastic film (polyimide film, etc.). An object (crocodile) is cast and dried in a vacuum, in an inert gas such as nitrogen, or in the air using hot air or infrared rays in a temperature range of 20 to 180 ° C., preferably 20 to 150 ° C. Next, the obtained polyimide precursor film is peeled off from the substrate or the polyimide precursor film is peeled off from the substrate, and the end portion of the film is fixed in a vacuum or in an inert gas such as nitrogen. Alternatively, a polyimide film / substrate laminate or a polyimide film can be produced by heating imidizing in air at a temperature of, for example, 200 to 500 ° C, more preferably 250 to 450 ° C using hot air or infrared rays. it can. In order to prevent the obtained polyimide film from being oxidatively deteriorated, it is desirable that the heating imidization is carried out in vacuum or in an inert gas. If the temperature of heating imidization is not too high, it may be performed in air. Further, it is preferable to use a heat-resistant plastic film such as polyimide as the base material because the polyimide film of the present invention can be continuously produced.

Further, in the imidization reaction of the polyimide precursor, instead of the heat imidization by the heat treatment as described above, the polyimide precursor contains a dehydration cyclization reagent such as anhydrous acetic acid in the presence of a tertiary amine such as pyridine or triethylamine. It is also possible to carry out by chemical treatment such as immersing in a solution. Further, these dehydration cyclization reagents are put into a polyimide precursor composition (crocodile) in advance and stirred, and then cast and dried on a substrate to obtain a partially imidized polyimide precursor. It can also be produced, with the obtained partially imidized polyimide precursor film peeled off from the substrate or the polyimide precursor film peeled off from the substrate and the edges of the film fixed. By performing the heat treatment as described above, a polyimide film / base material laminate or a polyimide film can be obtained.

The polyimide film, the hard coat / polyimide film laminate, the polyimide film / substrate laminate, or the hard coat / polyimide film / substrate laminate obtained in this manner can be used as a display cover sheet (cover film) as described above. ), And can also be suitably used for substrates for displays, touch panels, solar cells, and the like. As an example, a cover sheet (cover film) using the polyimide film of the present invention will be described.

A flexible cover sheet (cover film) can be obtained from the polyimide film / base material laminate or the polyimide film obtained as described above by forming a hard coat layer on one side or both sides thereof.

The hard coat layer is used to prevent scratches and improve solvent resistance, and generally, acrylic resin, urethane resin, melamine resin, polysilazane or a mixture thereof, and those to which an inorganic substance is added are used. .. Although not particularly limited, those containing an acrylic resin are preferable because of their characteristics and the ability to form a film with UV in a short time.

The hard coat layer is formed by applying a hard coat solution containing a resin monomer, an oligomer, a low boiling point solvent such as methyl ethyl ketone or polypropylene glycol monomethyl ether on a polyimide film, and curing it with heat, light, or both. Be done. Inorganic particles such as a silane compound and silica and a curing initiator can be added as needed.

If the solvent resistance of the polyimide is low, problems such as haze appearing on the polyimide or roughening of the surface may occur due to an organic solvent such as methyl ethyl ketone contained in the hard coat solution.

By further forming a polarizing plate and a transparent electrode on the polyimide / hard coat laminate, a touch sensor can be formed using the cover sheet as a substrate.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

In each of the following examples, the evaluation was performed by the following method.

<Evaluation of polyimide film>
[Total light transmittance]
The total light transmittance of the polyimide film and the polyimide / hard coat laminate was measured using an ultraviolet-visible spectrophotometer / V-650DS (manufactured by JASCO Corporation).

[Haze]
The haze of the polyimide film and the polyimide / hard coat laminate was measured using a turbidity meter / NDH2000 (manufactured by Nippon Denshoku Kogyo) in accordance with the JIS K7136 standard.

[Tensile modulus, elongation at break, stress at break, load at break]
The polyimide film was punched into a dumbbell shape of IEC-540 (S) standard to make a test piece (width: 4 mm), and using TENSILON manufactured by ORIENTEC, the chuck length was 30 mm, the tensile speed was 2 mm / min, and the initial tensile elastic modulus. , Breaking point elongation, breaking point stress, breaking point load were measured.

[5% weight loss temperature]
Using a polyimide film as a test piece, the temperature was raised from 25 ° C. to 600 ° C. at a heating rate of 10 ° C./min in a nitrogen stream using a calorimeter measuring device (Q5000IR) manufactured by TA Instruments. From the obtained weight curve, the 5% weight loss temperature was determined.

[Solvent resistance test]
A polyimide film was used as a test piece and immersed in N-methyl-2-pyrrolidone for 1 hour, and the one in which there was no change such as dissolution or cloudiness of the polyimide film was marked with ◯, and the one with change was marked with x.

[Pencil hardness test]
According to the JIS K5600-5-4 standard, the pencil hardness of the hard-coated surface of the polyimide film and the polyimide / hard-coated laminate was measured under a load of 750 g.

[Crosscut test]
Adhesion test between polyimide and hard coat was performed in accordance with the standards of ASTM D3359-02.

The abbreviations, purity, etc. of the raw materials used in each of the following examples are as follows.

[Diamine component]
HAB: 3,3'-dihydroxybenzidine m-TD: 2,2'-dimethyl-4,4'-diaminobiphenyl [purity: 99.85% (GC analysis)]
[Tetracarboxylic acid component]
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride [purity: 99.9% (GC analysis)]
CpODA: Norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic dianhydride

[Imidazole compound]
1,2-dimethylimidazole

[solvent]
DMAc: N, N-dimethylacetamide

Table 1-1 shows the tetracarboxylic acid components used in Examples and Comparative Examples, Table 1-2 shows the Diamine components used in Examples and Comparative Examples, and Table 1-3 shows the imidazole compounds used in Examples and Comparative Examples. Write the structural formula.

[Hard coat]
Hard coat a: STR-SiA manufactured by Taisei Fine Chemicals Co., Ltd. was used. STR-SiA
To 100 g, 184 3 g of IRUGACURER was added as a photoinitiator and stirred at room temperature to obtain a hard coat solution (hard coat a).
Hard coat b: Fujikura Kasei FUJIHARDR HO3313U-8

[Example 1]
Put 2.16 g (10 mmol) of HAB in a reaction vessel replaced with nitrogen gas, and add 31.62 g of DMAc in an amount that makes the total mass of the charged monomers (total of diamine component and carboxylic acid component) 12% by mass. , Stirred for 1 hour at room temperature. 1.76 g (9 mmol) of CBDA and 0.38 g (1 mmol) of CpODA were gradually added to this solution. Stirring at room temperature for 12 hours gave a uniform and viscous polyimide precursor solution (varnish A).

0.19 g of 1,2-dimethylimidazole and 0.19 g of DMAc were added to the reaction vessel to obtain a uniform solution. The entire amount of the solution was added to varnish A (2 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish A), and the mixture was stirred at room temperature for 30 minutes to obtain a uniform and viscous polyimide precursor solution. Calculated from the amount charged, 1,2-dimethylimidazole is 0.2 mol per 1 mol of the repeating unit of the polyimide precursor.

A polyimide precursor solution filtered through a PTFE membrane filter is applied to a glass substrate, and under a nitrogen atmosphere (oxygen concentration of 200 ppm or less), the glass substrate is heated from room temperature to 260 ° C. for thermal imidization and is colorless. A transparent polyimide film / glass laminate was obtained. Next, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film A having a thickness of 35 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 2]
Put 1.08 g (5 mmol) of HAB and 1.06 g (5 mmol) of m-TD in a reaction vessel replaced with nitrogen gas, and add DMAc to the total mass of the charged monomers (total of diamine component and carboxylic acid component). 28.72 g, which is a mass%, was added, and the mixture was stirred at room temperature for 1 hour. 1.76 g (9 mmol) of CBDA and 0.38 g (1 mmol) of CpODA were gradually added to this solution. Stirring at room temperature for 12 hours gave a uniform and viscous polyimide precursor solution (varnish B).

0.19 g of 1,2-dimethylimidazole and 0.19 g of DMAc were added to the reaction vessel to obtain a uniform solution. The entire amount of the solution was added to varnish B (2 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B), and the mixture was stirred at room temperature for 30 minutes to obtain a uniform and viscous polyimide precursor solution. Calculated from the amount charged, 1,2-dimethylimidazole is 0.2 mol per 1 mol of the repeating unit of the polyimide precursor.

A polyimide precursor solution filtered through a PTFE membrane filter is applied to a glass substrate, and under a nitrogen atmosphere (oxygen concentration of 200 ppm or less), the glass substrate is heated from room temperature to 260 ° C. for thermal imidization and is colorless. A transparent polyimide film / glass laminate was obtained. Next, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film B having a thickness of 42 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 3]
Put 0.65 g (3 mmol) of HAB and 1.49 g (7 mmol) of m-TD in a reaction vessel replaced with nitrogen gas, and add DMAc to the total mass of the charged monomer (total of diamine component and carboxylic acid component). An amount of 31.42 g to be mass% was added, and the mixture was stirred at room temperature for 1 hour. 1.76 g (9 mmol) of CBDA and 0.38 g (1 mmol) of CpODA were gradually added to this solution. Stirring at room temperature for 12 hours gave a uniform and viscous polyimide precursor solution (varnish C).

0.19 g of 1,2-dimethylimidazole and 0.19 g of DMAc were added to the reaction vessel to obtain a uniform solution. The entire amount of the solution (2 mmol with respect to the molecular weight of the polyimide precursor repeating unit in the varnish C) was added to the varnish C, and the mixture was stirred at room temperature for 30 minutes to obtain a uniform and viscous polyimide precursor solution. Calculated from the amount charged, 1,2-dimethylimidazole is 0.2 mol per 1 mol of the repeating unit of the polyimide precursor.

A polyimide precursor solution filtered through a PTFE membrane filter is applied to a glass substrate, and under a nitrogen atmosphere (oxygen concentration of 200 ppm or less), the glass substrate is heated from room temperature to 260 ° C. for thermal imidization and is colorless. A transparent polyimide film / glass laminate was obtained. Next, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film C having a thickness of 35 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 4]
0.22 g (1 mmol) of HAB and 1.91 g (9 mmol) of m-TD were placed in a reaction vessel replaced with nitrogen gas, and DMAc was added to the total mass of the charged monomers (total of diamine component and carboxylic acid component). 31.36 g, which is a mass%, was added, and the mixture was stirred at room temperature for 1 hour. 1.76 g (9 mmol) of CBDA and 0.38 g (1 mmol) of CpODA were gradually added to this solution. Stirring at room temperature for 12 hours gave a uniform and viscous polyimide precursor solution (varnish D).

0.19 g of 1,2-dimethylimidazole and 0.19 g of DMAc were added to the reaction vessel to obtain a uniform solution. The entire amount of the solution (2 mmol with respect to the molecular weight of the polyimide precursor repeating unit in the varnish D) was added to the varnish D, and the mixture was stirred at room temperature for 30 minutes to obtain a uniform and viscous polyimide precursor solution. Calculated from the amount charged, 1,2-dimethylimidazole is 0.2 mol per 1 mol of the repeating unit of the polyimide precursor.

A polyimide precursor solution filtered through a PTFE membrane filter is applied to a glass substrate, and under a nitrogen atmosphere (oxygen concentration of 200 ppm or less), the glass substrate is heated from room temperature to 260 ° C. for thermal imidization and is colorless. A transparent polyimide film / glass laminate was obtained. Next, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film D having a film thickness of 34 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Comparative Example 1]
In a reaction vessel was replaced with nitrogen gas put HAB 0.11 g (0.5 mmol) and m-TD2.02g (9 .5 mmol), and DMAc, sum of charged monomers to the total mass (diamine component and a carboxylic acid component ) Was added in an amount of 12% by mass, and the mixture was stirred at room temperature for 1 hour. 1.76 g (9 mmol) of CBDA and 0.38 g (1 mmol) of CpODA were gradually added to this solution. Stirring at room temperature for 12 hours gave a uniform and viscous polyimide precursor solution (varnish E).

0.19 g of 1,2-dimethylimidazole and 0.19 g of DMAc were added to the reaction vessel to obtain a uniform solution. The entire amount of the solution was added to varnish E (2 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish E), and the mixture was stirred at room temperature for 30 minutes to obtain a uniform and viscous polyimide precursor solution. Calculated from the amount charged, 1,2-dimethylimidazole is 0.2 mol per 1 mol of the repeating unit of the polyimide precursor.

A polyimide precursor solution filtered through a PTFE membrane filter is applied to a glass substrate, and under a nitrogen atmosphere (oxygen concentration of 200 ppm or less), the glass substrate is heated from room temperature to 260 ° C. for thermal imidization and is colorless. A transparent polyimide film / glass laminate was obtained. Next, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film E having a film thickness of 33 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Examples 5 to 12, Comparative Examples 2 and 3]
The obtained polyimide films A to E were coated with the hard coat solutions a and b with a bar coater so that the thickness of the hard coat layer after drying was about 10 μm, dried at 80 ° C. for 10 minutes, and high-pressure mercury. Ultraviolet rays were irradiated using a lamp so that the integrated light amount was 1000 mJ / cm2. Then, it heated at 150 degreeC for 10 minutes, and obtained the polyimide / hard coat laminate.

The results of measuring the characteristics of this laminate are shown in Table 2-2.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a polyimide, a polyimide film, and a precursor thereof, which are excellent in surface hardness, transparency, and adhesion. The polyimide of the present invention and the polyimide obtained from the polyimide precursor of the present invention are excellent in surface hardness, transparency, adhesion, and have a low coefficient of linear thermal expansion. Therefore, for example, a cover sheet (protective film) for a display surface. In addition, it can be suitably used for substrates such as displays, touch panels, and solar cells.

Claims (15)

A repeating unit represented by the following chemical formula (1A), and a repeating unit represented by the following chemical formula (2A) seen including,
(In the formula, A ₁ is a divalent group having an aromatic ring containing at least _one of a hydroxyl group or a carboxyl group or another aromatic ring, and includes at least one of the hydroxyl group or a carboxyl group. The aromatic ring contains at least a group represented by the following chemical formula (D-1), and R ₁ and R ₂ are independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms, respectively. Is.)
(In the formula , A ₂ is a divalent group having an aromatic ring containing at least one of a hydroxyl group or a carboxyl group or another aromatic ring, and contains at least one of the hydroxyl group or a carboxyl group. The aromatic ring contains at least a group represented by the following chemical formula (D-1).
In the formula, X contains a group derived from norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acids.
R ₃ and R ₄ are independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms, respectively. )
The repeating unit represented by the chemical formula (1A) in which A ₁ is a group represented by the chemical formula (D-1) and the chemical formula (A ₂ ) is a group represented by the chemical formula (D-1). The total content of the repeating units represented by 2A) is 10 to 100 mol% with respect to all the repeating units.
A polyimide precursor characterized by this. The polyimide precursor according to claim 1, wherein the repeating unit represented by the chemical formula (1A) is 10 mol% or more based on all the repeating units. The content of the repeating unit represented by the chemical formula (1A) is 10 to 90 mol% with respect to all the repeating units.
The polyimide precursor according to claim 1 or 2, wherein the content of the repeating unit represented by the chemical formula (2A) is 10 to 90 mol% with respect to all the repeating units. A polyimide precursor composition containing the polyimide precursor according to any one of claims 1 to 3. A repeating unit represented by the following chemical formula (1), a repeating unit represented by the following chemical formula (2) seen including,
(In the formula, A ₁ is a divalent group having an aromatic ring containing at least _one of a hydroxyl group or a carboxyl group or another aromatic ring, and an fragrance containing at least _one of the hydroxyl group or a carboxyl group. The group ring contains at least a group represented by the following chemical formula (D-1).)
(In the formula , A ₂ is a divalent group having an aromatic ring containing at least one of a hydroxyl group or a carboxyl group or another aromatic ring, and an fragrance containing at least one of the hydroxyl group or a carboxyl group. The group ring contains at least a group represented by the following chemical formula (D-1).
In the formula, X contains a group derived from norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acids. )
The repeating unit represented by the chemical formula (1A) in which A ₁ is a group represented by the chemical formula (D-1) and the chemical formula (A ₂ ) is a group represented by the chemical formula (D-1). The total content of the repeating units represented by 2A) is 10 to 100 mol% with respect to all the repeating units.
Polyimide characterized by that. The polyimide according to claim 5 , wherein the repeating unit represented by the chemical formula (1) is 10 mol% with respect to all the repeating units. The content of the repeating unit represented by the chemical formula (1) is 10 to 90 mol% with respect to all the repeating units.
The polyimide according to claim 5 or 6 , wherein the content of the repeating unit represented by the chemical formula (2) is 10 to 90 mol% with respect to all the repeating units. The polyimide obtained from the polyimide precursor according to any one of claims 1 to 3 or the polyimide precursor composition according to claim 4 . A polyimide film obtained from the polyimide precursor according to any one of claims 1 to 3 or the polyimide precursor composition according to claim 4 . A polyimide laminate using the polyimide according to any one of claims 5 to 8 or the polyimide film according to claim 9 . A polyimide / hard coat laminate comprising the polyimide according to any one of claims 5 to 8 or the polyimide film according to claim 9 and a hard coat. A polyimide laminate comprising the polyimide according to any one of claims 5 to 8 or the polyimide film according to claim 9 and a polyimide film or glass other than the above. A polyimide / hard coat laminate comprising the polyimide according to any one of claims 5 to 8 or the polyimide film according to claim 9 , a hard coat, and a polyimide film or glass other than the above. The polyimide according to any one of claims 5 to 8 , the polyimide film according to claim 9, the polyimide laminate according to claim 12 , or the polyimide / hard coat laminate according to claim 13 is included. A cover sheet for the display surface of the display. The polyimide according to any one of claims 5 to 8 , the polyimide film according to claim 9, the polyimide laminate according to claim 12 , or the polyimide / hard coat laminate according to claim 13 is included. A substrate for a characteristic display, touch panel, or solar cell.