JP6627510B2 - Polyimide precursor composition, method for producing polyimide, polyimide, polyimide film, and substrate - Google Patents

Description

  The present invention relates to a solution composition (polyimide precursor composition) containing a polyimide precursor from which a polyimide having excellent transparency, mechanical properties, and excellent heat resistance can be obtained, and a method for producing a polyimide. The present invention also relates to a polyimide, a polyimide film, and a substrate that are excellent in transparency, mechanical properties, and heat resistance.

  In recent years, with the advent of the highly information-oriented society, the development of optical materials such as liquid crystal alignment films and protective films for color filters in the field of display devices, such as optical fibers and optical waveguides in the field of optical communication, has been progressing. In particular, in the field of display devices, a plastic substrate which is lightweight and excellent in flexibility as an alternative to a glass substrate, and a display which can be bent or rounded, are being actively developed. For this reason, there is a demand for a higher-performance optical material that can be used for such purposes.

  Aromatic polyimide is colored essentially yellow-brown due to intramolecular conjugation and formation of a charge transfer complex. Therefore, as means for suppressing coloring, for example, introduction of a fluorine atom into the molecule, imparting flexibility to the main chain, introduction of a bulky group as a side chain, etc., inhibit the intramolecular conjugation and the formation of the charge transfer complex. Then, a method of expressing transparency has been proposed. For example, Patent Document 1 discloses a highly transparent aromatic polyimide containing a fluorine atom.

  In addition, a method has been proposed in which a semi-alicyclic or all-alicyclic polyimide which does not form a charge transfer complex is used in principle to exhibit transparency. For example, Patent Documents 2 to 4 disclose highly transparent semi-alicyclic polyimides using an aromatic tetracarboxylic dianhydride as a tetracarboxylic acid component and an alicyclic diamine as a diamine component.

  Also, for example, Patent Documents 5 to 8 disclose various highly transparent semi-alicyclic polyimides using an alicyclic tetracarboxylic dianhydride as a tetracarboxylic acid component and an aromatic diamine as a diamine component. Have been.

  Patent Literatures 9 and 10 disclose polyimides using decahydro-1,4: 5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic acids as a tetracarboxylic acid component. . Non-Patent Document 1 discloses a polyimide using (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2t, 3t, 6c, 7c-tetracarboxylic acid as a tetracarboxylic acid component. Non-Patent Document 2 discloses that (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid is used as a tetracarboxylic acid component. Polyimides are disclosed.

  Non-Patent Document 3 discloses that as a tetracarboxylic acid component, norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acid A polyimide using an acid dianhydride is disclosed. Further, the norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic dianhydride used herein is 6 It is described as containing three types of stereoisomers. Patent Document 11 also discloses, as a tetracarboxylic acid component, norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acid A polyimide using dianhydride is disclosed.

  The alicyclic tetracarboxylic dianhydride as the tetracarboxylic acid component and the semi-alicyclic polyimide using the aromatic diamine as the diamine component have high transparency, bending resistance, and high heat resistance, but depending on the application. There is a demand for polyimides having even higher heat resistance.

  On the other hand, in Patent Document 12, a tetracarboxylic acid component containing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as a main component and a diamine component containing paraphenylenediamine as a main component are obtained. Polyamic acid, a polyamic acid solution composition containing a phosphorus compound is cast on a substrate, heat-treated, the thickness is less than 50μm on the substrate, the polyimide laminate to form a phosphorus-containing polyimide layer of the polyimide laminate A manufacturing method is disclosed. The phosphorus compounds used in the examples of Patent Document 12 are triphenyl phosphate, monoethyl phosphate, monolauryl phosphate, and polyphosphoric acid. Patent Document 12 describes that this manufacturing method can form a highly heat-resistant polyimide layer in which thermal decomposition is suppressed in a temperature range of 500 ° C to 650 ° C.

JP 2011-074384 A JP 2003-192787 A JP 2004-83814 A JP 2008-308550 A JP 2003-168800 A International Publication No. 2008/146637 JP-A-2002-69179 JP 2002-146021 A JP 2007-2023 A JP-A-6-51316 International Publication No. 2011/099518 International Publication No. 2012/173204

Macromolecules, Vol. 27, no. 5, P1117-1123, 1994 Macromolecules, Vol. 32, no. 15, P4933-4939, 1999 Journal of Polymers, Vol. 68, no. 3, p. 127-131 (2011)

  The present invention has been made in view of the above circumstances, is a polyimide having excellent transparency and mechanical properties, even with the same composition, a polyimide precursor composition from which a polyimide having higher heat resistance is obtained (Solution composition containing polyimide precursor) and a method for producing polyimide.

The present invention relates to the following items.
1. A polyimide precursor containing at least one of a repeating unit represented by the following chemical formula (1), a repeating unit represented by the following chemical formula (2), or a repeating unit represented by the following chemical formula (3):
A polyimide precursor composition comprising a phosphorus atom and a phosphorus compound having a boiling point at 1 atm lower than a decomposition temperature and 350 ° C. or lower.

（式中、Ｘ_１は脂環構造を有する４価の基であり、Ｙ_１は芳香族環を有する２価の基であり、Ｒ_１、Ｒ_２はそれぞれ独立に水素、炭素数１〜６のアルキル基、または炭素数３〜９のアルキルシリル基である。）

(In the formula, X ₁ is a tetravalent group having an alicyclic structure, Y ₁ is a divalent group having an aromatic ring, and R ₁ and R ₂ are each independently hydrogen, having 1 to 6 carbon atoms. Or an alkylsilyl group having 3 to 9 carbon atoms.)

（式中、Ｘ_２は芳香族環を有する４価の基であり、Ｙ_２は脂環構造を有する２価の基であり、Ｒ_３、Ｒ_４はそれぞれ独立に水素、炭素数１〜６のアルキル基、または炭素数３〜９のアルキルシリル基である。）

(In the formula, X ₂ is a tetravalent group having an aromatic ring, Y ₂ is a divalent group having an alicyclic structure, and R ₃ and R ₄ are each independently hydrogen, having 1 to 6 carbon atoms. Or an alkylsilyl group having 3 to 9 carbon atoms.)

（式中、Ｘ_３は芳香族環を有する４価の基であり、Ｙ_３は芳香族環を有する２価の基であり、ただし、Ｘ_３とＹ_３の少なくとも一方はフッ素原子を含有し、Ｒ_５、Ｒ_６はそれぞれ独立に水素、炭素数１〜６のアルキル基、または炭素数３〜９のアルキルシリル基である。）

(Wherein, X ₃ is a tetravalent group having an aromatic ring, Y ₃ is a divalent group having an aromatic ring, provided that at least one of X ₃ and Y ₃ contains a fluorine atom. , R ₅ and R ₆ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.)

2. Item 2. The polyimide precursor composition according to Item 1, wherein a boiling point of the phosphorus compound at 1 atm is 200 ° C or less.
3. Item 3. The polyimide precursor composition according to Item 1 or 2, wherein the phosphorus compound is any one of trimethyl phosphate, trimethyl phosphite, dimethyl phosphite, and diethyl phosphite.
4. 4. A method for producing a polyimide, comprising subjecting the polyimide precursor composition according to any one of the above items 1 to 3 to a heat treatment to imidize the polyimide precursor.
5. A step of applying the polyimide precursor composition according to any one of Items 1 to 3 on a substrate,
Wherein the polyimide precursor composition on the substrate is heat-treated to imidize the polyimide precursor.
6. Item 6. A polyimide produced by the method according to item 4 or 5.
7. Item 6. A polyimide film produced by the method according to item 4 or 5.
8. Item 7. A substrate for a display, a touch panel, or a solar cell, comprising the polyimide according to item 6 or the polyimide film according to item 7.

  According to the present invention, a polyimide precursor composition (solution composition containing a polyimide precursor), which is a polyimide excellent in transparency and mechanical properties and which can obtain a polyimide having higher heat resistance even with the same composition, and a polyimide A manufacturing method can be provided.

  The polyimide (polyimide of the present invention) obtained from the polyimide precursor composition of the present invention has high transparency, has higher heat resistance, has a low linear thermal expansion coefficient, and can easily form a fine circuit. Yes, it can be suitably used for forming substrates for display applications and the like. Further, the polyimide of the present invention can be suitably used for forming substrates for touch panels and solar cells.

  The polyimide precursor composition of the present invention includes at least one of a repeating unit represented by the chemical formula (1), a repeating unit represented by the chemical formula (2), and a repeating unit represented by the chemical formula (3). And a phosphorus compound having a boiling point at 1 atm lower than the decomposition temperature and 350 ° C. or lower. The polyimide precursor containing the repeating unit represented by the chemical formula (1) and the polyimide precursor containing the repeating unit represented by the chemical formula (2) are precursors of a semi-alicyclic polyimide, and are represented by the chemical formula ( The polyimide precursor containing a repeating unit represented by 3) is a precursor of an aromatic polyimide containing a fluorine atom.

  Polyimide obtained from a polyimide precursor containing at least one of the repeating unit represented by the chemical formula (1), the repeating unit represented by the chemical formula (2), or the repeating unit represented by the chemical formula (3); That is, semi-alicyclic polyimides and aromatic polyimides containing fluorine atoms have high transparency. In the case of such a highly transparent polyimide, the use of an additive such as a phosphorus compound which may cause coloring is not preferred. However, even if a phosphorus compound having a boiling point at 1 atm lower than the decomposition temperature and 350 ° C. or lower, particularly preferably 200 ° C. or lower, is added to the polyimide precursor composition, the transparency of the obtained polyimide is not impaired, The performance is further improved. That is, according to the present invention, a polyimide having higher heat resistance can be obtained from a polyimide precursor having the same composition while maintaining high transparency. When the phosphorus compound to be added to the polyimide precursor composition is a phosphorus compound having a boiling point at 1 atm higher than the decomposition temperature, such as phosphoric acid, or a phosphorus compound having a boiling point at 1 atm exceeding 350 ° C., such as triphenyl phosphate, is obtained. The transparency of the polyimide decreases.

  As described above, the polyimide precursor composition of the present invention includes a repeating unit represented by the chemical formula (1), a repeating unit represented by the chemical formula (2), or a repeating unit represented by the chemical formula (3) A polyimide precursor containing at least one of the following.

X ₁ in the chemical formula (1) is preferably a tetravalent group having an alicyclic structure having 4 to 40 carbon atoms, and Y ₁ is a divalent group having an aromatic ring having 6 to 40 carbon atoms. Are preferred.

  Examples of the tetracarboxylic acid component that provides the repeating unit of the chemical formula (1) include 1,2,3,4-cyclobutanetetracarboxylic acid, isopropylidene diphenoxybisphthalic acid, and 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 ( Chlorohexane-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), octahydropentalen-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] oct-5-ene-2,3,7,8-tetracarboxylic acid, tricyclo [4.2.2.22 , 5] Can-3,4,7,8-tetracarboxylic acid, tricyclo [4.2.2.25] dec-7-ene-3,4,9,10-tetracarboxylic acid, 9-oxatricyclo [ 4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane 5,5 ′ ', 6,6' '-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid, (4arH, 8acH)- Decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2t, 3t, 6c, 7c-tetracarboxylic acid, tetracarboxylic dianhydride, tetracarboxylic silyl ester, tetracarboxylic acid Ether, and derivatives of such tetracarboxylic acid chloride. The tetracarboxylic acid component may be used alone or in combination of two or more.

  Examples of the diamine component that gives the repeating unit of the chemical formula (1) include, for example, p-phenylenediamine, m-phenylenediamine, benzidine, 3,3′-diamino-biphenyl, 2,2′-bis (trifluoromethyl) benzidine , 3,3'-bis (trifluoromethyl) benzidine, m-tolidine, 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, bis (4-aminophenyl) bis (4-aminocarboxylate) Phenyl) ester, p-phenylenebis (p-aminobenzoate), bis (4-amido) Nophenyl)-[1,1′-biphenyl] -4,4′-dicarboxylate, [1,1′-biphenyl] -4,4′-diylbis (4-aminobenzoate), 4,4′-oxydi Aniline, 3,4'-oxydianiline, 3,3'-oxydianiline, p-methylenebis (phenylenediamine), 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-amino Phenoxy) 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 (tri (Fluoromethyl) 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, 2,4-bis (4-aminoanilino) -6-amino-1,3,5-triazine, 2,4-bis (4-aminoanilino)- 6-methylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-ethylamino-1,3,5-triazi And 2,4-bis (4-aminoanilino) -6-anilino-1,3,5-triazine. The diamine components may be used alone or in combination of two or more.

  The polyimide precursor containing at least one kind of the repeating unit represented by the chemical formula (1) may contain another repeating unit other than the repeating unit represented by the chemical formula (1). The tetracarboxylic acid component and the diamine component that provide other repeating units are not particularly limited, and any other known aromatic or aliphatic tetracarboxylic acids and any known aromatic or aliphatic diamines can be used. . Other tetracarboxylic acid components may be used alone or in combination of two or more. Other diamine components may be used alone or in combination of two or more.

  The content of other repeating units other than the repeating unit represented by the chemical formula (1) is preferably 30 mol% or less, or less than 30 mol%, more preferably 20 mol% or less, based on all repeating units. More preferably, it is preferably at most 10 mol%.

X ₂ in the chemical formula (2) is preferably a tetravalent group having an aromatic ring having 6 to 40 carbon atoms, and Y ₂ is a divalent group having an alicyclic structure having 4 to 40 carbon atoms. Are preferred.

  Examples of the tetracarboxylic acid component giving the repeating unit of the chemical formula (2) include, for example, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane and 4- (2,5-dioxotetrahydrofuran-3- Yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid, pyromellitic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 3,3 ′, 4,4′- Biphenyltetracarboxylic acid, 2,3,3 ', 4'-biphenyltetracarboxylic acid, 4,4'-oxydiphthalic acid, bis (3,4-dicarboxyphenyl) sulfone dianhydride, m-terphenyl-3, 4,3 ′, 4′-tetracarboxylic dianhydride, p-terphenyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, biscarboxyphenyldimethyl Emissions, bis-dicarboxyphenoxy diphenyl sulfide, or sulfonyl di phthalate, these tetracarboxylic dianhydrides, tetracarboxylic acid silyl ester, tetracarboxylic acid esters, derivatives of such tetracarboxylic acid chloride. The tetracarboxylic acid component may be used alone or in combination of two or more.

  Examples of the diamine component providing the repeating unit of the chemical formula (2) include 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 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, , 3-bis (aminomethyl) cyclohexane, diaminobicycloheptane, diamido Nomethylbicycloheptane, diaminooxybicycloheptane, diaminomethyloxybicycloheptane, isophoronediamine, diaminotricyclodecane, diaminomethyltricyclodecane, bis (aminocyclohexyl) methane, bis (aminocyclohexyl) isopropylidene 6,6 ′ -Bis (3-aminophenoxy) -3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane; 6,6'-bis (4-aminophenoxy) -3,3,3', 3 '-Tetramethyl-1,1'-spirobiindane. The diamine components may be used alone or in combination of two or more.

  The polyimide precursor containing at least one kind of the repeating unit represented by the chemical formula (2) may contain another repeating unit other than the repeating unit represented by the chemical formula (2). The tetracarboxylic acid component and the diamine component that provide other repeating units are not particularly limited, and any other known aromatic or aliphatic tetracarboxylic acids and any known aromatic or aliphatic diamines can be used. . Other tetracarboxylic acid components may be used alone or in combination of two or more. Other diamine components may be used alone or in combination of two or more.

  The content of other repeating units other than the repeating unit represented by the chemical formula (2) is preferably 30 mol% or less, or less than 30 mol%, more preferably 20 mol% or less, based on all repeating units. More preferably, it is preferably at most 10 mol%.

X ₃ in the chemical formula (3) is preferably a tetravalent group having an aromatic ring having 6 to 40 carbon atoms, and Y ₃ is a divalent group having an aromatic ring having 6 to 40 carbon atoms. Are preferred. The may be one in which one of X ₃ or Y ₃ contains a fluorine atom, or may be both of X ₃ and Y ₃ contains a fluorine atom.

  Examples of the fluorine atom-containing tetracarboxylic acid component that provides the repeating unit of the chemical formula (3) include 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane and tetracarboxylic acid Derivatives such as anhydride, silyl ester of tetracarboxylic acid, ester of tetracarboxylic acid, and tetracarboxylic acid chloride are exemplified. Examples of the tetracarboxylic acid component containing no fluorine atom include 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid, Pyromellitic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, , 4'-oxydiphthalic acid, bis (3,4-dicarboxyphenyl) sulfone dianhydride, m-terphenyl-3,4,3 ', 4'-tetracarboxylic dianhydride, p-terphenyl-3 , 4,3 ', 4'-tetracarboxylic dianhydride, biscarboxyphenyldimethylsilane, bisdicarboxyphenoxydiphenyl sulfide, sulfonyl diphthalic acid, These tetracarboxylic acid dianhydrides, tetracarboxylic acid silyl ester, tetracarboxylic acid esters, derivatives of such tetracarboxylic acid chloride. The tetracarboxylic acid component may be used alone or in combination of two or more.

  Examples of the diamine component containing a fluorine atom and giving the repeating unit of the chemical formula (3) include 2,2′-bis (trifluoromethyl) benzidine, 3,3′-bis (trifluoromethyl) benzidine, , 2-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2'-bis (3-amino-4-hydroxyphenyl) Hexafluoropropane is mentioned. Further, as a diamine component containing no fluorine atom, for example, p-phenylenediamine, m-phenylenediamine, benzidine, 3,3′-diamino-biphenyl, m-tolidine, 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-phenylenebis (p-aminobenzoate), bis (4-aminophenyl)-[1,1'- Biphenyl] -4,4'-dicarboxylate, [1,1'-biphenyl] -4,4'-diylbis (4-aminobenzo Eate), 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, bis (4-aminophenyl) sulfone, 3,3′-bis ((aminophenoxy) phenyl) propane, 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, 2,4-bis (4-aminoanilino) -6-amino-1,3,5-triazine, 2,4 -Bis (4-aminoanilino) -6-methylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-ethylamino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6-anilino-1,3,5-triazine. The diamine components may be used alone or in combination of two or more.

  The polyimide precursor containing at least one kind of the repeating unit represented by the chemical formula (3) may contain another repeating unit other than the repeating unit represented by the chemical formula (3). The tetracarboxylic acid component and the diamine component that provide other repeating units are not particularly limited, and any other known aromatic or aliphatic tetracarboxylic acids and any known aromatic or aliphatic diamines can be used. . Other tetracarboxylic acid components may be used alone or in combination of two or more. Other diamine components may be used alone or in combination of two or more.

  The content of other repeating units other than the repeating unit represented by the chemical formula (3) is preferably 30 mol% or less, or less than 30 mol%, more preferably 20 mol% or less, based on all repeating units. More preferably, it is preferably at most 10 mol%.

  The polyimide precursor may include at least one kind of the repeating unit represented by the chemical formula (1) and at least one kind of the repeating unit represented by the chemical formula (2). ) And at least one of the repeating units represented by the chemical formula (3), and at least one of the repeating units represented by the chemical formula (2) It may contain one kind and at least one kind of the repeating unit represented by the chemical formula (3), or may contain at least one kind of the repeating unit represented by the chemical formula (1) and the chemical formula (2) )) And at least one of the repeating units represented by the chemical formula (3). Also in that case, the content of other repeating units other than the repeating units represented by the chemical formulas (1), (2) and (3) is preferably 30 mol% or less or 30 mol% or less based on all repeating units. It is preferably less than mol%, more preferably 20 mol% or less, further preferably 10 mol% or less.

  In one embodiment, the polyimide precursor includes, for example, a repeating unit represented by the following chemical formula (1-1-1), more preferably a repeating unit represented by the following chemical formula (1-1-2) Polyimide precursors are preferred.

（式中、Ａ_１は芳香族環を有する２価の基であり、Ｒ_１、Ｒ_２はそれぞれ独立に水素、炭素数１〜６のアルキル基、または炭素数３〜９のアルキルシリル基である。）

(In the formula, A ₁ is a divalent group having an aromatic ring, and R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. is there.)

（式中、Ａ_１は芳香族環を有する２価の基であり、Ｒ_１、Ｒ_２はそれぞれ独立に水素、炭素数１〜６のアルキル基、または炭素数３〜９のアルキルシリル基である。）

(In the formula, A ₁ is a divalent group having an aromatic ring, and R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. is there.)

However, in the chemical formula (1-1-1) and the chemical formula (1-1-2), one of the acid groups at the 2- or 3-position of the decahydro-1,4: 5,8-dimethanonaphthalene ring is amino. Reacts with a group to form an amide bond (—CONH—), _{one of} which is a group represented by —COOR ₁ that does not form an amide bond, and one of the acid groups at the 6-position or the 7-position is an amino group. A amide bond (—CONH—) formed by reacting with the group, and one of the groups is a group represented by —COOR ₂ that does not form an amide bond. That is, in the chemical formulas (1-1-1) and (1-1-2), four structural isomers, that is, (i) a group represented by -COOR ₁ at the 2-position is substituted at the 3-position. having a group represented by -CONH-, a group represented by -COOR ₂ in 6-position, 7-position _{-CONH-a 1} - having a group represented by, (ii) at the 3-position - The group represented by COOR ₁ has a group represented by -CONH- at the 2-position, a group represented by -COOR ₂ at the 6-position, and -CONH-A ₁ -at the 7-position. A group having a group represented by -COOR ₁ at the 2-position, a group represented by -COOR ₂ at the 7-position, and a group represented by -COOR ₂ at the 7-position; Having a group represented by -CONH-A ₁ -at the position, (iv) a group represented by -COOR ₁ at the 3-position and a group represented by -CONH- at the 2-position All having a group represented by -COOR ₂ at the 7-position and a group represented by -CONH-A ₁ -at the 6-position.

Further, the polyimide precursor is represented by a chemical formula (1-1-1) in which A ₁ is a group represented by the following chemical formula (1-1-A), and more preferably represented by a chemical formula (1-1-2). It is preferable to include at least one type of repeating unit.

（式中、ｍ_１は０〜３の整数を、ｎ_１は０〜３の整数をそれぞれ独立に示す。Ｖ_１、Ｕ_１、Ｔ_１はそれぞれ独立に水素原子、メチル基、トリフルオロメチル基よりなる群から選択される１種を示し、Ｚ_１、Ｗ_１はそれぞれ独立に直接結合、または 式：−ＮＨＣＯ-、−ＣＯＮＨ-、−ＣＯＯ-、−ＯＣＯ-で表される基よりなる群から選択される１種を示す。）

(Wherein, m ₁ independently represents an integer of 0 to 3, n ₁ independently represents an integer of 0 to 3. V ₁ , U ₁ , and T ₁ each independently represent a hydrogen atom, a methyl group, a trifluoromethyl group. represents one selected from the group consisting _of, Z 1, _{W 1} are each independently a direct bond or the formula: -NHCO -, - CONH -, - COO -, - the group consisting of groups represented by OCO- One type selected from the following.)

In other words, in one embodiment, the polyimide precursor is decahydro-1,4: 5,8-dimetanonaphthalene-2,3,6,7-tetracarboxylic acid, and more preferably (4arH, 8acH). -Decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2t, 3t, 6c, 7c-tetracarboxylic acids and the like (tetracarboxylic acids and the like are tetracarboxylic acids, tetracarboxylic dianhydrides, tetracarboxylic acids silyl esters, tetracarboxylic acid esters, and the tetracarboxylic acid component comprising representing the tetracarboxylic acid derivatives, such as tetracarboxylic acid chloride), a diamine component having an aromatic ring, more preferably a ₁ is formula (1-1- A diamine which gives a repeating unit represented by the formula (1-1-1) or the formula (1-1-2) which is a group represented by A) It is a polyimide precursor obtained from a diamine component containing a min component.

  Examples of the tetracarboxylic acid component providing the repeating unit of the above-mentioned chemical formula (1-1-1) include decahydro-1,4: 5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic acid and the like. The species may be used alone, or a plurality of species may be used in combination. As the tetracarboxylic acid component giving the repeating unit of the chemical formula (1-1-2), (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2t, 3t, 6c, 7c-tetra One type such as carboxylic acids may be used alone, or a plurality of types may be used in combination.

Diamine component giving the recurring unit of the formula (1-1-1) or the formula (1-1-2) gives what is a _{group A 1} is represented by Formula (1-1-A) It is preferable to include a diamine.

A ₁ is a group represented by the chemical formula (1-1-A), and the diamine component giving the repeating unit of the chemical formula (1-1-1) or the chemical formula (1-1-2) has an aromatic ring. In the case of having a plurality of aromatic rings, the aromatic rings are each independently connected by a direct bond, an amide bond, or an ester bond. The connection position between the aromatic rings is not particularly limited, but is bonded to the amino group or the connection group between the aromatic rings at the 4-position to form a linear structure, and the resulting polyimide may have low linear thermal expansion. . Further, a methyl group or a trifluoromethyl group may be substituted on the aromatic ring. The replacement position is not particularly limited.

The diamine component giving a repeating unit of the chemical formula (1-1-1) or the chemical formula (1-1-2), wherein A ₁ is a group represented by the chemical formula (1-1-A), is particularly limited. However, for example, p-phenylenediamine, m-phenylenediamine, benzidine, 3,3′-diamino-biphenyl, 2,2′-bis (trifluoromethyl) benzidine, 3,3′-bis (trifluoromethyl ) Benzidine, m-tolidine, 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 Bis (4-aminophenyl) ester, p-phenylenebis (p-aminobenzoate), bis (4-aminophenyl)-[1,1′-biphenyl] -4,4′-dicarboxylate, [1,1 '-Biphenyl] -4,4'-diylbis (4-aminobenzoate) and the like, may be used alone, or a plurality of them may be used in combination. Among these, p-phenylenediamine, m-tolidine, 4,4′-diaminobenzanilide, 4-aminophenoxy-4-diaminobenzoate, 2,2′-bis (trifluoromethyl) benzidine, benzidine, N, N '-Bis (4-aminophenyl) terephthalamide and biphenyl-4,4'-dicarboxylic acid bis (4-aminophenyl) ester are preferred, and p-phenylenediamine, 4,4'-diaminobenzanilide, 2,2' -Bis (trifluoromethyl) benzidine is more preferred. By using p-phenylenediamine, 4,4'-diaminobenzanilide, and 2,2'-bis (trifluoromethyl) benzidine as the diamine component, the resulting polyimide has both high heat resistance and high transmittance. . These diamines may be used alone or in combination of two or more. o-Tolidine is not preferred due to its high risk.

Formula (1-1-1) or the formula (1-1-2) a diamine component which gives the _{A 1} in (i.e., the formula (1-1-1) or the chemical formula (1-1-2) As the diamine component providing a repeating unit), other diamines other than the diamine component giving A ₁ having the structure of the chemical formula (1-1-A) can be used in combination. Other aromatic or aliphatic diamines can be used as other diamine components. For example, 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-amino Phenoxy) 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- (Doxyphenyl) 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-s ec-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, diaminooxybicycloheptane, diaminomethyloxybicycloheptane, isophoronediamine, diaminotricyclodecane, diaminomethyltricyclodecane, bis (aminocyclohexyl) methane, bis (Aminocyclohexyl) isopropylidene 6,6'-bis (3-aminophenoxy) -3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane, 6,6'-bis (4-aminophenoxy ) -3,3,3 ', 3'-Tetramethyl-1,1'-spirobi Examples thereof include indane and the like and derivatives thereof, which may be used alone or in combination of two or more. 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 is preferred, and 4,4'-bis (4-aminophenoxy) biphenyl is particularly preferred.

The polyimide precursor of the present invention, the formula (1-1-1) or Formula repeating units in 100 mol% represented by (1-1-2), _{A 1} is the formula (1-1-A) The proportion of the repeating unit represented by the chemical formula (1-1-1) or the chemical formula (1-1-2), which is a group represented by the formula, is preferably 50 mol% or more, more preferably 70 mol% in total. It is preferably at least 90 mol%, particularly preferably at least 100 mol%. A ₁ is a group represented by the chemical formula (1-1-A), and the proportion of the repeating unit represented by the chemical formula (1-1-1) or (1-1-2) is from 50 mol% If it is small, the resulting polyimide may have a large coefficient of linear thermal expansion.

  In one embodiment, from the viewpoint of the characteristics of the obtained polyimide, the compound represented by the formula (1-1) or the compound represented by the formula (1-1-1) or the repeating unit represented by the formula (1-1-2) in 100 mol%. The proportion of the diamine component giving the structure of -1-A) may be preferably 70 mol% or less, more preferably 80 mol% or less, and further preferably 90 mol% or less in total. For example, other diamines such as a diamine having an ether bond (—O—) such as 4,4′-oxydianiline and 4,4′-bis (4-aminophenoxy) biphenyl are converted to the compound represented by the chemical formula (1- For example, 40 mol% or less, preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 100 mol% of the diamine component giving the repeating unit of 1-1) or the formula (1-1-2). It may be preferable to use it at 10 mol% or less.

As described above, in the polyimide precursor containing a repeating unit represented by the chemical formula (1-1-1) or the chemical formula (1-1-2) of the present invention, the chemical formula (1-1-1) or the A ₁ in the chemical formula (1-1-2) is preferably the aforementioned chemical formula (1-1-A). In other words, the diamine component that gives the repeating unit of the chemical formula (1-1-1) or the chemical formula (1-1-2) is a group in which A ₁ is a group represented by the chemical formula (1-1-A). It is preferable that the diamine component gives a repeating unit of a certain chemical formula (1-1-1) or chemical formula (1-1-2). Formula (1-1-1) or the formula (1-1-2) a diamine component which gives the _{A 1} in (i.e., the formula (1-1-1) or the chemical formula (1-1-2) The diamine component which gives a repeating unit) gives the repeating unit of the chemical formula (1-1-1) or the chemical formula (1-1-2) in which A ₁ is a group represented by the chemical formula (1-1-A). By being a diamine component, the heat resistance of the obtained polyimide is improved.

In certain embodiments, the chemical formula (1-1-1) or Formula polyimide precursor containing a repeating unit represented by formula (1-1-2) of the present invention, _{A 1} is the formula (1-1 It may be preferable to include at least two types of repeating units represented by the formula (1-1-1) or the formula (1-1-2), which are groups represented by -A). In other words, the diamine component that gives the repeating unit of the chemical formula (1-1-1) or the chemical formula (1-1-2) is a group in which A ₁ is a group represented by the chemical formula (1-1-A). It may be preferable to include at least two types of diamine components that provide a repeating unit of the formula (1-1-1) or the formula (1-1-2). Formula (1-1-1) or the formula (1-1-2) a diamine component which gives the _{A 1} in (i.e., the formula (1-1-1) or the chemical formula (1-1-2) diamine component giving the repeating units), by a ₁ contains at least two kinds of diamine components giving a structure of the formula (1-1-a), high transparency of the resulting polyimide and a low linear thermal expansion Properties (ie, a polyimide having high transparency and a low coefficient of linear thermal expansion is obtained).

In this embodiment, for example, the polyimide precursor containing a repeating unit represented by the chemical formula (1-1-1) or the chemical formula (1-1-2) of the present invention is prepared by using the chemical formula (1-1-1) 1) or the formula (1-1-2) a diamine component which gives the _{a 1} in (i.e., the formula (1-1-1) or the diamine component giving the recurring unit of the formula (1-1-2)) but includes at least two kinds of diamine component a ₁ gives a structure of the formula (1-1-a), it is preferable of one is 4,4'-diaminobenzanilide. Comprises at least two kinds of diamine component Formula (1-1-1) or the diamine component to provide a _{A 1} of the formula (1-1-2) in give a structure of the formula (1-1-A), When one of them is 4,4'-diaminobenzanilide, a polyimide having high heat resistance in addition to high transparency and low linear thermal expansion can be obtained.

In one embodiment, the polyimide precursor containing a repeating unit represented by the chemical formula (1-1-1) or the chemical formula (1-1-2) according to the present invention is a polyimide precursor according to the chemical formula (1-1-1): or the formula (1-1-2) a diamine component which gives the _{a 1} in (i.e., the diamine component giving the recurring unit of the formula (1-1-1) or the formula (1-1-2)) 2 And at least one selected from 2,2'-bis (trifluoromethyl) benzidine and p-phenylenediamine and 4,4'-diaminobenzanilide. By combining these diamine components, a polyimide having both high transparency, low linear thermal expansion and heat resistance can be obtained.

In this embodiment, the chemical formula (1-1-1) or the formula (1-1-2) a diamine component which gives the _{A 1} in (i.e., the formula (1-1-1) or the chemical formula (1 The diamine component which gives the repeating unit of -1-2) preferably contains 4,4'-diaminobenzanilide in an amount of 20 mol% or more and 80 mol% or less, and contains p-phenylenediamine and 2,2 '. -Bis (trifluoromethyl) benzidine preferably contains not less than 20 mol% and not more than 80 mol% in both or both, and more preferably not less than 30 mol% and not less than 70 mol% of 4,4′-diaminobenzanilide. % Or less, and 30 mol% or more and 70 mol% of either or both of p-phenylenediamine and 2,2′-bis (trifluoromethyl) benzidine. It is preferable that the compound contains at least 40 mol% and not more than 60 mol% of 4,4′-diaminobenzanilide, and that p-phenylenediamine and 2,2′-bis (trifluoromethyl) benzidine More preferably, the content is 40 mol% or more and 60 mol% or less in either one or both.

  The polyimide precursor of the present invention may include other repeating units other than the repeating unit represented by the formula (1-1-1) or the formula (1-1-2).

  As the tetracarboxylic acid component providing another repeating unit, other aromatic or aliphatic tetracarboxylic acids can be used. For example, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2 -Dicarboxylic acid, pyromellitic acid, 3,3 ', 4,4'-benzophenonetetracarboxylic 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 dianhydride, p- Terphenyl-3,4,3 ', 4'-tetracarboxylic dianhydride, biscarboxyphenyldimethylsilane, bisdicarboxyphenoxydiphenylsulfide, sulfonyldif Sulfonic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, isopropylidenediphenoxybisphthalic 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 (S Hexane-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), octahydropentalen-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] oct-5-ene-2,3,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] decane-3,4,7,8-tetracarboxylic acid, tricyclo [ 4.2.2.22 , 5] Deca-7-ene-3,4,9,10-tetracarboxylic acid, 9-oxatricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid , Norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane 5,5 ″, 6,6 ″ -tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t : Derivatives such as 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid, and acid dianhydrides thereof, which may be used alone or in combination of two or more You can also. Among these, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid, norbornane -2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane 5,5 ″, 6,6 ″ -tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c , 8c-Dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid and the like and derivatives of these acid dianhydrides are easy to produce polyimide, and the resulting polyimide has excellent heat resistance. preferable. These acid dianhydrides may be used alone or in combination of two or more.

The diamine component giving another repeating unit includes a repeating unit of the formula (1-1-1) or the formula (1-1-2) in which A ₁ is a group represented by the formula (1-1-A). The diamine exemplified as the diamine component to be provided may be used.

  As the diamine component providing another repeating unit, other aromatic or aliphatic diamines can be used. For example, 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-amino Phenoxy) 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-a No-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, -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, diaminooxybicycloheptane, diaminomethyloxybicycloheptane, isophoronediamine, diaminotricyclodecane, diaminomethyltricyclodecane, bis (aminocyclo Xyl) methane, bis (aminocyclohexyl) isopropylidene 6,6′-bis (3-aminophenoxy) -3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane, 6,6′-bis (4-aminophenoxy) -3,3,3 ', 3'-tetrame Examples thereof include tyl-1,1′-spirobiindane and the derivatives thereof, which may be used alone or in combination of two or more.

  In one embodiment, the polyimide precursor comprises a total of repeating units represented by the chemical formula (1-1-1) or the chemical formula (1-1-2) in all the repeating units, preferably 50. It is preferably contained in an amount of at least 70 mol%, more preferably at least 70 mol%, further preferably at least 90 mol%, particularly preferably at least 100 mol%. When the proportion of the repeating unit represented by the chemical formula (1-1-1) or the chemical formula (1-1-2) is 50 mol% or more, the film forming property is improved, and the coefficient of linear thermal expansion of the obtained polyimide is improved. Becomes extremely small. Further, from the viewpoint of the total light transmittance, the repeating unit represented by the chemical formula (1-1-1) or the chemical formula (1-1-2) is preferably 50 mol% in 100 mol% of all the repeating units. % To 99 mol%, more preferably 60 mol% to 95 mol%, particularly preferably 70 mol% to 95 mol%.

  In another embodiment, as the polyimide precursor, for example, a polyimide precursor containing a repeating unit represented by the following chemical formula (1-2-1) is preferable, and the following chemical formula (1-2-2) and the following chemical formula (1-2-2) are preferable. At least one kind of the repeating unit represented by (1-2-3) is contained, and the total content of the repeating units represented by the chemical formulas (1-2-2) and (1-2-3) is all repeating units. A polyimide precursor in an amount of 80 mol% or more based on the unit is more preferable.

（式中、Ａ_２は芳香族環を有する２価の基であり、Ｒ_１、Ｒ_２はそれぞれ独立に水素、炭素数１〜６のアルキル基、または炭素数３〜９のアルキルシリル基である。）

(Wherein, A ₂ is a divalent group having an aromatic ring, and R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. is there.)

（式中、Ａ_２は芳香族環を有する２価の基であり、Ｒ_１、Ｒ_２はそれぞれ独立に水素、炭素数１〜６のアルキル基、または炭素数３〜９のアルキルシリル基である。）

(Wherein, A ₂ is a divalent group having an aromatic ring, and R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. is there.)

（式中、Ａ_２は芳香族環を有する２価の基であり、Ｒ_１、Ｒ_２はそれぞれ独立に水素、炭素数１〜６のアルキル基、または炭素数３〜９のアルキルシリル基である。）

(Wherein, A ₂ is a divalent group having an aromatic ring, and R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. is there.)

However, the chemical formula (1-2-1), the chemical formula (1-2-2) and the chemical formula (1-2-3) are represented by 5 of two norbornane rings (bicyclo [2.2.1] heptane). One of the acid groups at the 6-position or the 6-position reacts with the amino group to form an amide bond (—CONH—), and _one of the groups represented by —COOR ₁ not forming an amide bond, or —COOR It is a group represented by ₂ . That is, in the chemical formulas (1-2-1), (1-2-2) and (1-2-3), four structural isomers, that is, (i) -COOR _{1 at the} 5-position A group represented by —CONH— at the 6-position, a group represented by —COOR ₂ at the 5 ″ position, and —CONH-A ₂ — at the 6 ″ position (Ii) a group represented by -COOR ₁ at the 6-position, a group represented by -CONH- at the 5-position, and -COOR ₂ at the 5 "-position based, _{-CONH-a 2} to the position 6 '' - having a group represented by, (iii) the 5-position group represented by -COOR _1, represented by -CONH- the 6-position group Having a group represented by —COOR ₂ at the 6 ″ position and a group represented by —CONH-A ₂ — at the 5 ″ position, and (iv) a group represented by —COOR ₁ at the 6 ″ position. Group Has a group represented by -CONH- at the 5 position, a group represented by -COOR ₂ at the 6 '' position, and a group represented by -CONH-A ₂ -at the 5 '' position Everything is included.

Further, the polyimide precursor, repeating units, more preferably _{A 2} is represented by the following chemical _{formula A 2} is represented by the following chemical formula (1-2-A) is a group represented by the formula (1-2-1) ( It is preferable to include at least one kind of the repeating unit represented by the chemical formula (1-2-2) and / or the chemical formula (1-2-3), which is a group represented by 1-2-A).

（式中、ｍ_２は０〜３の整数を、ｎ_２は０〜３の整数をそれぞれ独立に示す。Ｖ_２、Ｕ_２、Ｔ_２はそれぞれ独立に水素原子、メチル基、トリフルオロメチル基よりなる群から選択される１種を示し、Ｚ_２、Ｗ_２はそれぞれ独立に直接結合、または 式：−ＮＨＣＯ-、−ＣＯＮＨ-、−ＣＯＯ-、−ＯＣＯ-で表される基よりなる群から選択される１種を示す。）

(In the formula, m ₂ represents an integer of 0 to 3, n ₂ independently represents an integer of 0 to _3. V ₂ , U ₂ , and T ₂ each independently represent a hydrogen atom, a methyl group, or a trifluoromethyl group. represents one selected from the group consisting _of, Z 2, _{W 2} are each independently a direct bond or the formula: -NHCO -, - CONH -, - COO -, - the group consisting of groups represented by OCO- One type selected from the following.)

In other words, in one embodiment, the polyimide precursor is norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″-. Tetracarboxylic acids and the like, more preferably trans-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetra Carboxylic acids and / or cis-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids (Tetracarboxylic acids and the like include tetracarboxylic acids and tetracarboxylic dianhydrides, tetracarboxylic silyl esters, tetracarboxylic esters, tetracarboxylic acid chlorides and the like. A tetracarboxylic acid component containing represents a carboxylic acid derivative), a diamine component having an aromatic ring, the formula is a group more preferably A ₂ is represented by the formula (1-2-A) (1-2- 1) A polyimide precursor obtained from a diamine component including a diamine component giving a repeating unit represented by the chemical formula (1-2-2) or the chemical formula (1-2-3).

  Examples of the tetracarboxylic acid component that gives the repeating unit of the chemical formula (1-2-1) include norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, One kind, such as 6,6 ″ -tetracarboxylic acids, may be used alone, or two or more kinds may be used in combination. The tetracarboxylic acid component giving the repeating unit of the above chemical formula (1-2-2) includes trans-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane- One kind such as 5,5 ″, 6,6 ″ -tetracarboxylic acids may be used alone, or a plurality of kinds may be used in combination. As the tetracarboxylic acid component giving the repeating unit of the above formula (1-2-3), cis-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane- One kind such as 5,5 ″, 6,6 ″ -tetracarboxylic acids may be used alone, or a plurality of kinds may be used in combination.

  In a more preferred form of the polyimide precursor, a tetracarboxylic acid component (trans-endo-endo-norbornane-2-spiro-α-cyclopentanone-α) giving a repeating unit of the above chemical formula (1-2-2) '-Spiro-2' '-norbornane-5,5' ', 6,6' '-tetracarboxylic acids, etc.) may be used, and the repetition of the chemical formula (1-2-3) may be used. Tetracarboxylic acid component (cis-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetra Carboxylic acid) may be used alone, and a tetracarboxylic acid component (trans-endo-end) providing a repeating unit of the above-mentioned chemical formula (1-2-2) may be used. -Norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids and the like; Tetracarboxylic acid component (cis-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″) giving a repeating unit of 1-2-3) , 6,6 ″ -tetracarboxylic acids, etc.).

  The polyimide precursor has a total content of the repeating units represented by the chemical formulas (1-2-2) and (1-2-3) of 80 mol% or more based on all the repeating units. Is preferable, that is, at least one kind of the repeating units represented by the chemical formulas (1-2-2) and (1-2-3) is contained, and the repeating units are preferably contained in all the repeating units in total. Is preferably at least 80 mol%, more preferably at least 90 mol%, still more preferably at least 95 mol%, particularly preferably at least 99 mol%. At least one kind of the repeating units represented by the chemical formulas (1-2-2) and (1-2-3) is contained, and the total number of the repeating units is preferably 80 mol% or more in all the repeating units. By including it, the coefficient of linear thermal expansion of the obtained polyimide is reduced.

Formula (1-2-1), or Formula (1-2-2), the diamine component giving the recurring unit of the formula (1-2-3) are, _{A 2} is the formula (1-2-A It is preferable to include a diamine which gives a group represented by the formula (1).

Diamine component A ₂ gives the repeating unit of the structure a is chemical formula of formula (1-2-A) (1-2-1), or formula (1-2-2), formula (1-2-3) Is a compound having an aromatic ring, and when having a plurality of aromatic rings, the aromatic rings are each independently connected by a direct bond, an amide bond, or an ester bond. The connection position between the aromatic rings is not particularly limited, but is bonded to the amino group or the connection group between the aromatic rings at the 4-position to form a linear structure, and the resulting polyimide may have low linear thermal expansion. . Further, a methyl group or a trifluoromethyl group may be substituted on the aromatic ring. The replacement position is not particularly limited.

Diamine component A ₂ gives the repeating unit of the structure a is chemical formula of formula (1-2-A) (1-2-1), or formula (1-2-2), formula (1-2-3) Although not particularly limited, for example, p-phenylenediamine, m-phenylenediamine, benzidine, 3,3′-diamino-biphenyl, 2,2′-bis (trifluoromethyl) benzidine, 3,3 '-Bis (trifluoromethyl) benzidine, m-tolidine, 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'-dicarboxylic acid bis (4-aminophenyl) ester, p-phenylenebis (p-aminobenzoate), bis (4-aminophenyl)-[1,1'-biphenyl] -4,4'-dicarboxy Rate, [1,1′-biphenyl] -4,4′-diylbis (4-aminobenzoate) and the like, and may be used alone or in combination of two or more. Among these, p-phenylenediamine, m-tolidine, 4,4′-diaminobenzanilide, 4-aminophenoxy-4-diaminobenzoate, 2,2′-bis (trifluoromethyl) benzidine, benzidine, N, N '-Bis (4-aminophenyl) terephthalamide and biphenyl-4,4'-dicarboxylic acid bis (4-aminophenyl) ester are preferred, and p-phenylenediamine, 4,4'-diaminobenzanilide, 2,2' -Bis (trifluoromethyl) benzidine is more preferred. By using p-phenylenediamine, 4,4'-diaminobenzanilide, and 2,2'-bis (trifluoromethyl) benzidine as the diamine component, the resulting polyimide has both high heat resistance and high transmittance. . These diamines may be used alone or in combination of two or more. In certain embodiments, those in which the diamine component is only one of 4,4'-diaminobenzanilide can be excluded. In one embodiment, the diamine component is 4,4′-diaminobenzanilide, and the chemical formula (1-2-1) wherein A ₂ has a structure other than the chemical formula (1-2-A), or the chemical formula (1-2). 1-2-2), formula (diamine component _{(a 2} giving the recurring unit formula (1-2-a 1-2-3)) other than the diamine component to give a structure of the other diamine ) Can be excluded. In addition, o-tolidine is not preferable because of its high risk.

Formula (1-2-1), or Formula (1-2-2), the diamine component giving the recurring unit of the formula (1-2-3), _{A 2} is the chemical formula (1-2- Other diamines other than the diamine component giving the structure of A) can be used in combination. Other aromatic or aliphatic diamines can be used as other diamine components. As other diamine components, for example, 4,4′-oxydianiline, 3,4′-oxydianiline, 3,3′-oxydianiline, bis (4-aminophenyl) sulfide, p-methylenebis (phenylenediamine ), 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis [4- ( 4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, bis (4-aminophenyl) sulfone, 3,3-bis ((aminophenoxy) phenyl) propane, , 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, bis (4- (4-aminophenoxy) diphenyl B) sulfone, bis (4- (3-aminophenoxy) diphenyl) sulfone, octafluorobenzidine, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dichloro-4,4′-diamino Biphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 9,9-bis (4-aminophenyl) fluorene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propyl Cyclohexane, 1,4-diamino-2-isopropylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-dia No-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, diaminooxybicycloheptane, diaminomethyloxybicycloheptane, isophorone diamine, diaminotricyclodecane, diamino Methyltricyclodecane, bis (aminocyclohexyl) methane, bis (aminocyclohexyl) isopropylidene 6,6′-bis (3-aminophenoxy) -3,3,3 ′, 3′-tetramethyl-1,1 '-Spirobiindane, 6,6'-bis ( -Aminophenoxy) -3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane and the derivatives thereof, and may be used alone or in combination of two or more. You can also.

In the polyimide precursor of the present invention, at least one kind of the repeating unit represented by the chemical formula (1-2-1) wherein A ₂ is represented by the chemical formula (1-2-A), and more preferably A ₂ Table with at least one and / or _{a 2} is the formula of repeating units (1-2-a) of the formula but is represented by formula (1-2-a) (1-2-2) It is preferable that at least one kind of the repeating unit represented by the chemical formula (1-2-3) is included. In other words, the repeating unit of the chemical formula (1-2-1), more preferably the diamine component providing the repeating units of the chemical formulas (1-2-2) and (1-2-3) is A ₂ Preferably contains a diamine component giving a compound having the structure of the above chemical formula (1-2-A). Repeating units of the formula (1-2-1), and more preferably the formula (1-2-2) and the formula (1-2-3) wherein the diamine component formula giving the _{A 2} in (1-2 The heat resistance of the obtained polyimide is improved by being a diamine component giving the structure of -A).

The polyimide precursor of the present invention, the formula (1-2-1), or Formula (1-2-2) and the formula (1-2-3) diamine component 100 mole% giving _{A 2} in In total, the proportion of the diamine component giving the structure of the chemical formula (1-2-A) is preferably 50 mol% or more, more preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more. It is preferably at least 100 mol%, particularly preferably at least 100 mol%. In other words, the formula _{A 2} is a structure of the formula (1-2-A) (1-2-1), or Formula (1-2-2) and the formula (1-2-3) The total of one or more types of the repeating unit represented by the formula (1-2-1) or the total repetition represented by the formula (1-2-2) and the formula (1-2-3) In the unit, it is preferably at least 50 mol%, more preferably at least 70 mol%, more preferably at least 80 mol%, further preferably at least 90 mol%, particularly preferably at least 100 mol%. When the proportion of the diamine component giving the structure of the chemical formula (1-2-A) is less than 50 mol%, the obtained polyimide may have a large coefficient of linear thermal expansion. In one embodiment, from the viewpoint of mechanical properties of the obtained polyimide, the chemical formula (1-2-1), or A in the chemical formula (1-2-2) and the chemical formula (1-2-3) is used. in the diamine component 100 mol% to give _2, the proportion of the diamine component to provide a structure of the formula (1-2-a) is, in total, preferably 80 mol% or less, more preferably 90 mol% or less or 90 mole% It may be preferred that it is less than. For example, other aromatic or aliphatic diamines such as 4,4′-oxydianiline can be prepared using the above-mentioned chemical formula (1-2-1), or the above chemical formulas (1-2-2) and (1-2). It can be used in an amount of preferably less than 20 mol%, more preferably 10 mol% or less, more preferably less than 10 mol% in 100 mol% of the diamine component providing the repeating unit of -3).

In some embodiments, the polyimide precursor containing a repeating unit represented by the chemical formula of the present invention (1-2-1) are those in which A ₂ is represented by the formula (1-2-A) It may be preferable to include at least two kinds of the repeating units represented by the chemical formula (1-2-1). In one embodiment, the polyimide precursor containing the repeating unit represented by the chemical formula (1-2-2) and / or the repeating unit represented by the chemical formula (1-2-3) of the present invention is A _It may be preferable that at least two kinds of the repeating units of the chemical formula (1-2-2) or the chemical formula (1-2-2) in which 2 is represented by the chemical formula (1-2-A) are included. In other words, the diamine component giving the repeating unit of the chemical formula (1-2-1) or the diamine component giving the repeating unit of the chemical formula (1-2-2) and the chemical formula (1-2-3) is used. , a ₂ it may be preferred to include at least two kinds of diamine component providing what the the structure of formula (1-2-a). A ₂ in the chemical formula (1-2-1), or a diamine component giving A ₂ in the chemical formulas (1-2-2) and (1-2-3) is the chemical formula (1-2). -A) By containing at least two kinds of diamine components giving the structure of (A), the obtained polyimide can be balanced between high transparency and low linear thermal expansion (that is, high transparency and low linear heat). A polyimide having an expansion coefficient is obtained).

Incidentally, the polyimide precursor of the present invention may be one A ₂ contains at least two repeating units of the structure in which the chemical formula (1-2-2) of the formula (1-2-A), the may be one _{a 2} contains at least two repeating units of the structure in which the chemical formula (1-2-3) of the formula (1-2-a), also, _{a 2} is the chemical formula ( At least one kind of the repeating unit of the chemical formula (1-2-2) having the structure of 1-2-A), and the chemical formula (1-2) wherein A ₂ is a structure of the chemical formula (1-2-A) It may include at least one repeating unit of -3).

In some embodiments, the polyimide precursor of the present invention comprises:
(I) _{A 2} is a _{m 2} and / or _{n 2} is 1 to 3, _{Z 2} and / or _{W 2} are each independently, -NHCO -, - CONH -, - COO-, or -OCO- The chemical formula (1-2-1), which is a structure of the chemical formula (1-2-A), which is preferably any of the chemical formulas (1-2-2) and (1-2-3) At least one kind of the repeating unit (I),
(Ii) A ₂ is a structure of the above formula (1-2-A) wherein m ₂ and n ₂ are 0, or m ₂ and / or n ₂ is 1 to 3, and Z ₂ and The chemical formula (1-2-1), which is a structure of the chemical formula (1-2-A) in which W ₂ is a direct bond, preferably the chemical formula (1-2-2) and the chemical formula (1-2-3) It is sometimes more preferable that at least one kind of the repeating unit (II)) is contained.

In this embodiment, as the repeating unit (I), for example, the chemical formula (1-2-1) wherein A ₂ is represented by any of the following chemical formulas (D-1) to (D-3) preferably repeating units), _{a 2} is the repeating unit is more preferably the following formula (D-1) ~ (D -2) formula is represented by any one of (1-2-1). Incidentally, the diamine _{component A 2} gives a repeating unit of the following chemical formula (D-1) or the following Formula Formula are those represented by (D-2) (1-2-1) is 4,4'-diamino A benzanilide wherein A ₂ is represented by the following chemical formula (D-3); a diamine component providing a repeating unit of the above chemical formula (1-2-1) is bis (4-aminophenyl) terephthalate; These diamines may be used alone or in combination of two or more.

In this embodiment, as the repeating unit (II), for example, the chemical formula (1-2-1) wherein A ₂ is represented by any of the following chemical formulas (D-4) to (D-6) preferably repeating units), _{a 2} is the repeating unit is more preferably the following formula (D-4) ~ (D -5) wherein formula is represented by any one of (1-2-1). Incidentally, the diamine component giving the repeating unit of _{A 2} is represented by the following Formula Formula is represented by (D-4) (1-2-1) is a p- phenylenediamine, _{A 2} is represented by the following formula (D The diamine component giving the repeating unit of the above chemical formula (1-2-1) represented by -5) is 2,2′-bis (trifluoromethyl) benzidine, and A ₂ is represented by the following chemical formula (D- The diamine component that gives the repeating unit of the chemical formula (1-2-1) represented by 6) is m-tolidine, and these diamines may be used alone or in combination of two or more. Can also be used.

In the polyimide precursor of this embodiment, the proportion of one or more of the repeating units (I) is, in total, 30 mol% or more and 70 mol% of all the repeating units represented by the chemical formula (1-2-1). And the proportion of at least one kind of the repeating unit (II) is 30 mol% or more and 70 mol% or less in total of all the repeating units represented by the chemical formula (1-2-1). Preferably, the proportion of one or more of the repeating units (I) is 40 mol% or more and 60 mol% or less in total of all the repeating units represented by the chemical formula (1-2-1). (II) It is particularly preferable that the proportion of at least one kind is 40 mol% or more and 60 mol% or less in total of all the repeating units represented by the chemical formula (1-2-1). In one embodiment, the total proportion of the repeating unit (I) is more preferably less than 60 mol%, more preferably 50 mol%, in all the repeating units represented by the chemical formula (1-2-1). %, More preferably at most 40 mol%. In one embodiment, in addition to the repeating unit (I) and the repeating unit (II), a repeating unit represented by the above-mentioned chemical formula (1-2-1) (for example, A ₂ has a plurality of aromatic units) Having a ring and aromatic rings connected by an ether bond (—O—)) in all the repeating units represented by the chemical formula (1-2-1), preferably less than 20 mol%, More preferably, it may be preferable that the content be 10 mol% or less, particularly preferably less than 10 mol%. Further, in one embodiment, the proportion of one or more of the repeating units (I) is, in total, 20 mol% or more and 80 mol% or less in all the repeating units represented by the chemical formula (1-2-1). And the proportion of one or more of the repeating units (II) is preferably 20 mol% or more and 80 mol% or less in total of all the repeating units represented by the chemical formula (1-2-1). Sometimes.

In one embodiment, the polyimide precursor containing the repeating unit of the chemical formula (1-2-1) or the chemical formula (1-2-2) and / or the chemical formula (1-2-3) of the present invention is , the formula (1-2-1), or formula (1-2-2) and the formula (1-2-3) a diamine component which gives _{a 2} in (chemical formula of (1-2-1) The repeating unit or the diamine component providing the repeating units of the chemical formulas (1-2-2) and (1-2-3)) is at least two of the diamine components providing the structure of the chemical formula (1-2-A). It is preferred that one kind is 4,4'-diaminobenzanilide. Structure of the formula (1-2-1), or Formula (1-2-2) and the diamine component which gives _{A 2} in Formula (1-2-3) is the formula (1-2-A) Containing at least two kinds of diamine components, one of which is 4,4'-diaminobenzanilide, thereby obtaining a polyimide having high heat resistance in addition to high transparency and low linear thermal expansion. Can be

In one embodiment, the polyimide precursor containing the repeating unit of the chemical formula (1-2-1) or the chemical formula (1-2-2) and / or the chemical formula (1-2-3) of the present invention is , the formula (1-2-1), or formula (1-2-2) and the formula (1-2-3) a diamine component which gives _{a 2} in (chemical formula of (1-2-1) A repeating unit or a diamine component providing the repeating units of the above formulas (1-2-2) and (1-2-3)) is composed of 2,2′-bis (trifluoromethyl) benzidine and p-phenylenediamine It is particularly preferred to include at least one selected from them and 4,4′-diaminobenzanilide. By combining these diamine components, a polyimide having both high transparency, low linear thermal expansion and heat resistance can be obtained.

In this embodiment, the chemical formula (1-2-1), or Formula (1-2-2) and the formula (1-2-3) diamine component (Formula giving _{A 2} in (1 As the repeating unit of 2-1) or the diamine component providing the repeating units of the chemical formulas (1-2-2) and (1-2-3), preferably 4,4'-diaminobenzanilide is used. 20 mol% or more and 80 mol% or less, and 20 mol% or more and 80 mol% or less of either or both of p-phenylenediamine and 2,2′-bis (trifluoromethyl) benzidine More preferably, it contains 4,4′-diaminobenzanilide in an amount of 30 mol% or more and 70 mol% or less, and p-phenylenediamine and 2,2′-bis (trifluoromethyl) It is preferable to contain 30 mol% or more and 70 mol% or less of either or both of the above-mentioned zindidines, and it is particularly preferable that 4,4′-diaminobenzanilide be contained at 40 mol% or more and 60 mol% or less, and It is more preferable that one or both of p-phenylenediamine and 2,2′-bis (trifluoromethyl) benzidine be contained in an amount of 40 mol% or more and 60 mol% or less. In the chemical formula (1-2-1), or the chemical formula (1-2-2) and the chemical formula (1-2-3), 4,4′-diaminobenzanilide is used as a diamine component to give A ₂ in 30 units. At least 70 mol%, and at least 30 mol% and at most 70 mol% of either or both of p-phenylenediamine and 2,2′-bis (trifluoromethyl) benzidine. Thereby, a polyimide having both high transparency, low linear thermal expansion and heat resistance can be obtained. In one embodiment, the compound represented by the chemical formula (1-2-1) or the diamine component that provides A ₂ in the chemical formula (1-2-2) and the chemical formula (1-2-3) (the chemical formula (1- As the repeating unit of 2-1) or the diamine component giving the repeating units of the chemical formulas (1-2-2) and (1-2-3), 60 mol of 4,4′-diaminobenzanilide is used. %, More preferably not more than 50 mol%, particularly preferably not more than 40 mol%.

  The polyimide precursor of the present invention may be any other repeating unit other than the repeating units represented by the chemical formula (1-2-1) or the chemical formulas (1-2-2) and (1-2-3). Units can be included.

  As the tetracarboxylic acid component providing another repeating unit, other aromatic or aliphatic tetracarboxylic acids can be used. For example, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2 -Dicarboxylic acid, pyromellitic acid, 3,3 ', 4,4'-benzophenonetetracarboxylic 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 dianhydride, p- Terphenyl-3,4,3 ', 4'-tetracarboxylic dianhydride, biscarboxyphenyldimethylsilane, bisdicarboxyphenoxydiphenylsulfide, sulfonyldif Sulfonic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, isopropylidenediphenoxybisphthalic 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 (S Hexane-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), octahydropentalen-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] oct-5-ene-2,3,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] decane-3,4,7,8-tetracarboxylic acid, tricyclo [ 4.2.2.22 , 5] Deca-7-ene-3,4,9,10-tetracarboxylic acid, 9-oxatricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid , (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-di Derivatives such as methanonaphthalene-2t, 3t, 6c, 7c-tetracarboxylic acid, and acid dianhydrides of these are cited, and may be used alone or in combination of two or more. Among these, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid, ( 4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene Derivatives such as -2t, 3t, 6c, 7c-tetracarboxylic acid, and acid dianhydrides of these are more preferred because polyimide can be easily produced and the resulting polyimide has excellent heat resistance. These acid dianhydrides may be used alone or in combination of two or more.

  In the case of a polyimide precursor containing a repeating unit of the above formula (1-2-2) and / or the above formula (1-2-3), cis-endo- as a tetracarboxylic acid component providing another repeating unit is used. endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids and the like, and trans-endo-endo-norbornane Other norbornane-2-spiro-α other than 2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids and the like -Cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids and the like (for example, norbornane-2-spiro-α-cyclic) Pentanone -α'- spiro-2 '' - norbornane-5,5 ', 6,6' '- it is also possible to use four kinds of stereoisomers of tetracarboxylic dianhydride).

The diamine component giving another repeating unit may be a diamine component giving the structure of the above-mentioned chemical formula (1-2-A). In other words, as the diamine component which gives the other recurring unit, recurring unit, or _{A 2} is the chemical formula of _{A 2} is the formula (1-2-A) structure in which the chemical formula (1-2-1) ( The diamine exemplified as the diamine component providing the repeating unit of the chemical formula (1-2-2) and the chemical formula (1-2-3) having the structure of 1-2-A) can be used. These diamines may be used alone or in combination of two or more.

  As the diamine component providing another repeating unit, other aromatic or aliphatic diamines can be used. For example, 4,4'-oxydianiline, 3,4'-oxydianiline, 3,3'-oxydianiline, bis (4-aminophenyl) sulfide, p-methylenebis (phenylenediamine), 1,3- Bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl Hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, bis (4-aminophenyl) sulfone, 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, 9,9-bis (4-aminophenyl) fluorene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) Biphenyl, 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- Sobutylcyclohexane, 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, diaminooxybicycloheptane, diaminomethyloxybicycloheptane, isophoronediamine, diaminotricyclodecane, diaminomethyltricyclo Decane, bis (aminocyclohexyl) methane, bis (aminocyclohexyl) isopropylidene 6,6′-bis (3-aminophenoxy) -3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane , 6,6'-bis (4-aminop Enoxy) -3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane and the derivatives thereof; they may be used alone or in combination of two or more. .

  The method for synthesizing norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids and the like is not particularly limited. Can be synthesized by the method described in Patent Document 11. As described in Non-Patent Document 3, some stereoisomers may be included depending on the synthesis method. Purify norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids or the like, or an intermediate thereof by a column or the like. By doing so, it is possible to separate each of the stereoisomers individually or a mixture of several types.

  trans-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids and the like, and cis-endo -Endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids, etc., or a mixture thereof For norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acids and the like, or an intermediate thereof And the like.

  When the tetracarboxylic acid component and the diamine component contain isomers, the isomers may be isolated and used for polymerization or the like, or the isomers may be used as a mixture for polymerization or the like.

In the polyimide precursor of the present invention, R ₁ and R _{2 in} the chemical formula (1), R ₃ and R _{4 in} the chemical formula (2), and R ₅ and R _{6 in} the chemical formula (3) are each independently hydrogen or carbon. An alkyl group having 1 to 6, preferably 1 to 3 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. For R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ , the type of the functional group and the introduction rate of the functional group can be changed by the production method described later.

When R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ are hydrogen, the production of polyimide tends to be easy.

Further, when R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ 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. There is. In this case, R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ are more preferably a methyl group or an ethyl group.

Further, when R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ 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 , R ₅ and R ₆ are more preferably a trimethylsilyl group or a t-butyldimethylsilyl group.

The introduction ratio 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 , R ₅ and R ₆ are each 25% or more, preferably 50% or more. % Or more, more preferably 75% or more can be an alkyl group or an alkylsilyl group.

The polyimide precursor of the present invention has the following chemical structures depending on the chemical structure taken by R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ : 1) Polyamic acid (R ₁ and R ₂ , R ₃ and R ₄ , R ₅₎ And R ₆ are hydrogen), 2) polyamide acid ester (at least a part of R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ is an alkyl group), 3) 4) polyamic acid silyl ester (R ₁ And at least some of R ₂ , R ₃ and R ₄ , R ₅ and R ₆ can be classified as alkylsilyl groups). And the polyimide precursor of this invention can be easily manufactured by the following manufacturing methods for every classification. However, the method for producing the polyimide precursor of the present invention is not limited to the following production method.

1) Polyamic Acid In the polyimide precursor of the present invention, a tetracarboxylic dianhydride as a tetracarboxylic acid component and a diamine component are substantially equimolar in a solvent, preferably a molar ratio of the diamine component to the tetracarboxylic acid component [diamine Component / mol number of tetracarboxylic acid component] is preferably 0.90 to 1.10, more preferably 0.95 to 1.05, for example, 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.

  Although it is not limited, more specifically, a diamine is dissolved in an organic solvent, and tetracarboxylic dianhydride is gradually added to this solution with stirring, and the solution is added at 0 to 120 ° C, preferably 5 to 80 ° C. The polyimide precursor is obtained by stirring for 1 to 72 hours in the range of ° C. 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 there is a possibility that a polyimide precursor cannot be produced stably. The order of addition of the diamine and the tetracarboxylic dianhydride in the above production method is preferable because the molecular weight of the polyimide precursor tends to increase. In addition, the order of addition of the diamine and the tetracarboxylic dianhydride in the above-mentioned production method can be reversed, which is preferable because precipitates are reduced.

  When the molar ratio between the tetracarboxylic acid component and the diamine component is excessive, the carboxylic acid derivative is added, if necessary, in an amount substantially corresponding to the number of excess moles of the diamine component. The molar ratio of the components can be approximated to an equivalent. As the carboxylic acid derivative here, does not substantially increase the viscosity of the polyimide precursor solution, that is, a tetracarboxylic acid that does not substantially participate in molecular chain elongation, or a tricarboxylic acid and an anhydride thereof that functions as a terminal stopper, Dicarboxylic acids and their anhydrides are preferred.

2) Polyamic acid ester Tetracarboxylic dianhydride is reacted with an arbitrary alcohol to obtain a diester dicarboxylic acid, and then reacted with a chlorinating reagent (thionyl chloride, oxalyl chloride, etc.) to obtain a diester dicarboxylic acid chloride. The polyimide precursor is obtained by stirring the diester dicarboxylic acid chloride and the diamine in the range of -20 to 120C, preferably -5 to 80C 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 there is a possibility that a polyimide precursor cannot be produced stably. Alternatively, a polyimide precursor can be easily obtained by dehydrating and condensing a diester dicarboxylic 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, it can be purified by reprecipitation by adding a solvent such as water or alcohol.

3) Polyamic acid silyl ester (indirect method)
The diamine is reacted with the 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 tetracarboxylic dianhydride is gradually added thereto with stirring, and the mixture is added at a temperature of 0 to 120 ° C, preferably 5 to 80 ° C. By stirring for ~ 72 hours, a polyimide precursor is obtained. 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 there is a possibility that a polyimide precursor cannot be produced stably.

  It is preferable to use a chlorine-free silylating agent as the silylating agent used here, since 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 preferred because they do not contain a fluorine atom and are low in cost.

  In addition, in the silylation reaction of the diamine, an amine catalyst such as pyridine, piperidine, and 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)
The polyamic acid solution obtained by the method 1) and the silylating agent are mixed, and the mixture is stirred at 0 to 120 ° C, preferably 5 to 80 ° C for 1 to 72 hours to obtain a polyimide precursor. 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 there is a possibility that a polyimide precursor cannot be produced stably.

  It is preferable to use a chlorine-free silylating agent as the silylating agent used here, since 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 preferred because they do not contain a fluorine atom and are low in cost.

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

  Solvents used for preparing the polyimide precursor include, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethylsulfoxide Non-protic solvents such as N, N-dimethylacetamide are preferable, but any kind of solvent can be used without any problem as long as the raw material monomer components and the polyimide precursor to be formed can be dissolved. The structure is not limited. As the solvent, amide solvents 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 A system solvent, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide and the like are preferably employed. Further, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, tetrahydrofuran , Dimethoxyethane, diethoxyethane, dibutyl ether, diethylene glycol dimethyl ether, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methyl ethyl ketone, acetone, butanol, ethanol, xylene, toluene, chlorobenzene, terpen, mineral spirit, petroleum Naphtha solvents and the like can also be used. In addition, a solvent can also be used in combination of multiple types.

  In the present invention, the logarithmic viscosity of the polyimide precursor is not particularly limited, but the logarithmic viscosity in a 0.5 g / dL N, N-dimethylacetamide solution at 30 ° C. is 0.2 dL / g or more, more preferably 0 dL / g. It is preferably at least 0.3 dL / g, particularly preferably at least 0.4 dL / g. When the logarithmic viscosity is 0.2 dL / g or more, the molecular weight of the polyimide precursor is high, and the resulting polyimide has excellent mechanical strength and heat resistance.

  The polyimide precursor composition of the present invention contains a polyimide precursor and a phosphorus compound, and can be prepared by adding a phosphorus compound to the polyimide precursor solution or solution composition obtained by the above-mentioned production method. If necessary, the solvent may be removed or added, or a desired component other than the phosphorus compound may be added. In addition, a tetracarboxylic acid component (tetracarboxylic dianhydride, etc.), a diamine component and a phosphorus compound are added to a solvent, and the tetracarboxylic acid component and the diamine component are reacted in the presence of the phosphorus compound to obtain a polyimide of the present invention. A precursor composition (a solution composition containing a polyimide precursor and a phosphorus compound) can also be obtained.

  The phosphorus compound used in the present invention contains a phosphorus atom, has a boiling point at 1 atm lower than the decomposition temperature, and is 350 ° C or less, preferably less than 300 ° C, more preferably less than 250 ° C, still more preferably 210 ° C or less, particularly Preferably, it is a compound having a temperature of 200 ° C. or lower. By adding a phosphorus compound having a boiling point at 1 atm lower than the decomposition temperature and 350 ° C. or lower, preferably lower than 300 ° C., more preferably lower than 250 ° C., still more preferably 210 ° C. or lower, particularly preferably 200 ° C. or lower. A polyimide having higher heat resistance can be obtained while maintaining high transparency.

  The phosphorus compound used in the present invention is not particularly limited as long as the boiling point at 1 atm is lower than the decomposition temperature and is 350 ° C. or lower, but a compound having a PO bond is preferable, and trimethyl phosphate (boiling point at 1 atm: 197 ° C.), trimethyl phosphite (boiling point at 1 atm: 111.5 ° C.), dimethyl phosphite (boiling point at 1 atm: 171 ° C.), diethyl phosphite (boiling point at 1 atm: 188 ° C.) and the like are preferable. . A single phosphorus compound may be used alone, or a plurality of phosphorus compounds may be used in combination.

  In the present invention, the content of the phosphorus compound of the polyimide precursor composition is not particularly limited, but is preferably 0.01 mol or more, more preferably 0.03 mol or more per 1 mol of the repeating unit of the polyimide precursor. More preferably, it is more preferably 0.05 mol or more, and particularly preferably 0.1 mol or more. The upper limit of the phosphorus compound content of the polyimide precursor composition is not particularly limited, but is usually preferably 8 mol or less, more preferably 6 mol or less, and more preferably 5 mol or less, per 1 mol of the repeating unit of the polyimide precursor. Preferably less than 5 mol is particularly preferred. When the content of the phosphorus compound is too large, the heat resistance or the transparency of the obtained polyimide may decrease. Here, 1 mol of the repeating unit of the polyimide precursor corresponds to 1 mol of the tetracarboxylic acid component.

  The polyimide precursor composition of the present invention usually contains a solvent. The solvent used for the polyimide precursor composition of the present invention is not problematic as long as the polyimide precursor is dissolved, and its structure is not particularly limited. Examples of the solvent include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, and 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 and 4-chlorophenol Phenol solvents such as acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide and the like are preferably employed. Further, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, tetrahydrofuran , Dimethoxyethane, diethoxyethane, dibutyl ether, diethylene glycol dimethyl ether, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methyl ethyl ketone, acetone, butanol, ethanol, xylene, toluene, chlorobenzene, terpen, mineral spirit, petroleum Naphtha solvents and the like can also be used. Moreover, these can also be used in combination of multiple types. In addition, the solvent used at the time of preparing a polyimide precursor can be used for the solvent of a polyimide precursor composition as it is.

  In the present invention, the total amount of the tetracarboxylic acid component and the diamine component is at least 5% by mass, preferably at least 10% by mass, more preferably at least 15% by mass, based on the total amount of the solvent, the tetracarboxylic acid component and the diamine component. It is preferable that the ratio is not less than mass%. The total amount of the tetracarboxylic acid component and the diamine component is usually 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. It is suitable. This concentration is a concentration that is approximately similar to the solid content concentration due to the polyimide precursor, but if this concentration is too low, for example, it becomes difficult to control the thickness of the polyimide film obtained when manufacturing a polyimide film. Sometimes.

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

  The polyimide precursor composition of the present invention may contain, if necessary, a chemical imidizing agent (an acid anhydride such as acetic anhydride, or an amine compound such as pyridine or isoquinoline), an antioxidant, a filler (inorganic particles such as silica, etc.). ), Dyes, pigments, coupling agents such as silane coupling agents, primers, flame retardants, defoamers, leveling agents, rheology control agents (flow aids), release agents and the like.

  The polyimide of the present invention can be obtained by imidizing the above-described polyimide precursor composition of the present invention (that is, subjecting the polyimide precursor to a dehydration ring closure reaction). The imidation method is not particularly limited, and a known thermal imidization method or a chemical imidization method can be suitably applied. Preferred forms of the obtained polyimide include a film, a laminate of a polyimide film and another substrate, a coating film, powder, beads, a molded body, a foamed body, and the like.

  In the present invention, the polyimide precursor composition can be heat-treated to imidize the polyimide precursor. The maximum heating temperature of the heat treatment for imidization is not particularly limited, but is usually 200 ° C. or higher, preferably higher than 350 ° C., more preferably higher than 380 ° C., and particularly preferably higher than 400 ° C. preferable. By setting the maximum heating temperature of the heat treatment for imidization to a temperature exceeding 350 ° C., more preferably a temperature exceeding 380 ° C., and particularly preferably a temperature exceeding 400 ° C., the mechanical properties of the obtained polyimide are improved. I do. Although the upper limit of the maximum heating temperature of the heat treatment is not particularly limited, it is usually preferably 500 ° C. or lower.

  For example, the polyimide precursor composition of the present invention is cast and applied on a substrate, and the polyimide precursor composition on the substrate is subjected to heat treatment at a maximum heating temperature of 200 ° C. or more, more preferably at a temperature exceeding 350 ° C. Then, polyimide can be suitably produced by imidizing the polyimide precursor. Note that the heating profile is not particularly limited and can be appropriately selected, but from the viewpoint of productivity, the shorter the heating time, the better.

  Further, the polyimide precursor composition of the present invention is cast and applied on a substrate, preferably dried at a temperature range of 180 ° C. or less to form a film of the polyimide precursor composition on the substrate. The film of the polyimide precursor composition was peeled off from the substrate, and in a state where the end of the film was fixed, the maximum heating temperature was 200 ° C. or more, more preferably a heat treatment at a temperature exceeding 350 ° C., Polyimide can also be suitably produced by imidizing the polyimide precursor.

  A more specific example of a method for producing the polyimide (polyimide film / substrate laminate or polyimide film) of the present invention will be described later.

  The polyimide obtained from the polyimide precursor composition of the present invention (polyimide of the present invention) is not particularly limited, but has a coefficient of linear thermal expansion from 150 ° C. to 250 ° C. when formed into a film, preferably 65 ppm / K or less, It is more preferably at most 50 ppm / K, further preferably at most 35 ppm / K, further preferably at most 30 ppm / K, particularly preferably at most 20 ppm / K. If the coefficient of linear thermal expansion is large, the difference between the coefficient of linear thermal expansion with a conductor such as a metal is large, and problems such as an increase in warpage when forming a circuit board may occur.

  The polyimide obtained from the polyimide precursor composition of the present invention (polyimide of the present invention) is not particularly limited, but the total light transmittance (average light transmittance at a wavelength of 380 nm to 780 nm) in a film having a thickness of 10 μm is preferable. Can be 87% or more, more preferably 88% or more. When used in display applications and the like, if the total light transmittance is low, the light source needs to be strengthened, which may cause problems such as the application of energy.

  In particular, when a polyimide film such as a display is used for transmitting light, it is desirable that the polyimide film has high transparency. The polyimide obtained from the polyimide precursor composition of the present invention (polyimide of the present invention) is not particularly limited, but has a light transmittance at a wavelength of 400 nm of a film having a thickness of 10 μm, preferably 75% or more, more preferably 78% or more. %, More preferably at least 80%, particularly preferably more than 80%.

  In addition, the film made of the polyimide (polyimide of the present invention) obtained from the polyimide precursor composition of the present invention depends on the application, but the thickness of the film is preferably 0.1 μm to 250 μm, more preferably 1 μm to It is 150 μm, more preferably 1 μm to 50 μm, particularly preferably 1 μm to 30 μm. When the polyimide film is used for transmitting light, if the polyimide film is too thick, the light transmittance may decrease.

  The polyimide obtained from the polyimide precursor composition of the present invention (polyimide of the present invention) is not particularly limited, but a 1% weight loss temperature, which is an index of the heat resistance of the polyimide film, is preferably 440 ° C or higher, more preferably The temperature can be 450 ° C. or higher, more preferably 480 ° C. or higher, particularly preferably 485 ° C. or higher. When a gas barrier film or the like is formed over polyimide by forming a transistor over polyimide or the like, if heat resistance is low, swelling may occur between the polyimide and the barrier film due to outgas accompanying decomposition of the polyimide.

  The polyimide obtained from the polyimide precursor composition of the present invention, that is, the polyimide of the present invention has excellent properties such as high transparency, bending resistance, and high heat resistance, and further has an extremely low linear thermal expansion coefficient. It can be suitably used in applications of a transparent substrate for a display, a transparent substrate for a touch panel, or a substrate for a solar cell.

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

  For example, the polyimide precursor composition (varnish) of the present invention is cast on a substrate such as ceramic (glass, silicon, alumina, etc.), metal (copper, aluminum, stainless steel, etc.), heat-resistant plastic film (polyimide film, etc.). Drying is performed in a vacuum, in an inert gas such as nitrogen, or in air using hot air or infrared rays at a temperature in the range of 20 to 180 ° C, preferably 20 to 150 ° C. Then, the polyimide precursor film obtained on the substrate, or peel off the polyimide precursor film from the substrate, with the end of the film fixed, in a vacuum, in an inert gas such as nitrogen, Alternatively, it is possible to produce a polyimide film / substrate laminate or a polyimide film by heating and imidizing in air using hot air or infrared rays, for example, at a temperature of 200 to 500 ° C., preferably at a temperature exceeding 350 ° C. it can. Note that, in order to prevent the obtained polyimide film from being oxidized and degraded, it is preferable to perform the heat imidization in a vacuum or in an inert gas. Here, the thickness of the polyimide film (in the case of a polyimide film / substrate laminate, the polyimide film layer) is preferably 1 to 250 μm, more preferably 1 to 150 μm, for transportability in the subsequent steps.

  In addition, the imidation reaction of the polyimide precursor includes a dehydration cyclization reagent such as acetic anhydride in the presence of a tertiary amine such as pyridine or triethylamine instead of the heat imidation by the heat treatment as described above. It is also possible to carry out by chemical treatment such as immersion in a solution to be treated. In addition, these dehydration cyclization reagents are previously charged and stirred in a polyimide precursor composition (varnish), and then cast and dried on a base material to obtain a partially imidized polyimide precursor. A polyimide film / substrate laminate or a polyimide film can be obtained by further subjecting this to a heat treatment as described above.

  A flexible conductive substrate can be obtained by forming a conductive layer on one side or both sides of the polyimide film / substrate laminate or the polyimide film thus obtained.

  A flexible conductive substrate can be obtained, for example, by the following method. That is, as a first method, the polyimide film / substrate laminate is not peeled off the polyimide film from the substrate, but the conductive film (metal or metal oxide) is formed on the surface of the polyimide film by sputtering, vapor deposition, printing, or the like. A conductive layer of a conductive layer / polyimide film / substrate. Thereafter, if necessary, the conductive layer / polyimide film laminate is peeled off from the substrate, whereby a transparent and flexible conductive substrate composed of the conductive layer / polyimide film laminate can be obtained.

  As a second method, the polyimide film is peeled from the substrate of the polyimide film / substrate laminate to obtain a polyimide film, and a conductive substance (metal or metal oxide, conductive organic substance, A conductive layer of conductive carbon, etc.) is formed in the same manner as in the first method, and a transparent and flexible conductive layer of conductive layer / polyimide film laminate, conductive layer / polyimide film laminate / conductive layer is formed. A substrate can be obtained.

  In the first and second methods, if necessary, before forming a conductive layer on the surface of the polyimide film, a gas barrier layer of water vapor, oxygen, etc., by sputtering, vapor deposition, gel-sol method, etc. An inorganic layer such as a layer may be formed.

  The conductive layer is preferably formed with a circuit by a photolithography method, various printing methods, an inkjet method, or the like.

  The substrate of the present invention thus obtained has a circuit of a conductive layer on the surface of the polyimide film composed of the polyimide of the present invention via a gas barrier layer or an inorganic layer as necessary. This substrate is flexible, has excellent transparency, bendability, and heat resistance, and further has an extremely low coefficient of linear thermal expansion and excellent solvent resistance, so that a fine circuit can be easily formed. Therefore, this substrate can be suitably used as a substrate for a display, a touch panel, or a solar cell.

  That is, transistors (inorganic transistors, organic transistors) are further formed on the substrate by vapor deposition, various printing methods, ink jet methods, or the like to manufacture flexible thin film transistors, and a liquid crystal element for display devices, an EL element, It is suitably used as an element.

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

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

<Evaluation of polyimide film>
[400 nm light transmittance, total light transmittance]
Using a UV-visible spectrophotometer / V-650DS (manufactured by JASCO Corporation), the light transmittance at 400 nm and the total light transmittance (average transmittance at 380 nm to 780 nm) of the polyimide film having a thickness of about 10 μm were measured. The measured light transmittance at 400 nm and the total light transmittance at 10% reflectivity were used to calculate the light transmittance at 400 nm with a thickness of 10 μm and the total light transmittance using the Lambert-Beer equation. The calculation formula is shown below.

Log ₁₀ ((T ₁ +10) / 100) = 10 / L × (Log ₁₀ ((T ₁ ′ +10) / 100))
Log ₁₀ ((T ₂ +10) / 100) = 10 / L × (Log ₁₀ ((T ₂ ′ +10) / 100))
T ₁ : light transmittance (%) at 400 nm of a 10 μm-thick polyimide film when the reflectance is 10%
T ₁ ′: measured light transmittance at 400 nm (%)
T ₂ : total light transmittance (%) of a 10 μm-thick polyimide film when reflectance is 10%
T ₂ ′: measured total light transmittance (%)
L: Measured thickness of polyimide film (μm)

[Elastic modulus, elongation at break]
A polyimide film having a film thickness of about 10 μm is punched into a dumbbell shape conforming to IEC450 standard to prepare a test piece. Using TENSIRON manufactured by ORIENTEC, the initial elastic modulus and elongation at break are set at a chuck length of 30 mm and a tensile speed of 2 mm / min. It was measured.

[Linear thermal expansion coefficient (CTE)]
A polyimide film having a film thickness of about 10 μm is cut into a strip having a width of 4 mm to form a test piece, and using TMA / SS6100 (manufactured by SII Nanotechnology Co., Ltd.), the distance between the chucks is 15 mm, the load is 2 g, and the heating rate is 20 ° C. / The temperature was raised to 500 ° C. in minutes. From the obtained TMA curve, a linear thermal expansion coefficient from 150 ° C. to 250 ° C. was determined.

[1% weight loss temperature]
Using a polyimide film having a film thickness of about 10 μm as a test piece, the temperature was raised from 25 ° C. to 600 ° C. in a nitrogen gas flow at a rate of 10 ° C./min using a calorimeter (Q5000IR) manufactured by TA Instruments. From the obtained weight curve, a 1% weight loss temperature was determined.

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

[Diamine component]
DABAN: 4,4'-diaminobenzanilide [Purity: 99.90% (GC analysis)]
PPD: p-phenylenediamine [Purity: 99.9% (GC analysis)]
TFMB: 2,2'-bis (trifluoromethyl) benzidine [purity: 99.83% (GC analysis)]
4,4'-ODA: 4,4'-oxydianiline [Purity: 99.9% (GC analysis)]
BAPB: 4,4'-bis (4-aminophenoxy) biphenyl [purity: 99.93% (HPLC analysis)]
[Tetracarboxylic acid component]
s-BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride [purity 99.9% (H-NMR analysis)]
6FDA: 4,4 '-(2,2-hexafluoroisopropylene) diphthalic dianhydride [purity: 99.77% (H-NMR analysis)]
PMDA-HS: 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride [Purity: 99.9% (GC analysis)]
CpODA-tee: trans-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic dianhydride CpODA-cee: cis-endo-endo-norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acid Anhydrous CpODA: mixture of CpODA-tee and CpODA-cee

[solvent]
NMP: N-methyl-2-pyrrolidone

  Table 1-1 shows examples of tetracarboxylic acid components used in Examples and Comparative Examples, Table 1-2 shows Examples of diamine components used in Examples and Comparative Examples, Table 1-3 shows Examples of phosphorus compounds used in Examples and Comparative Examples. Write the structural formula.

[Synthesis Example 1]
In a reaction vessel purged with nitrogen gas, 90.91 g (0.40 mol) of DABAN and 64.88 g (0.60 mol) of PPD were added, and N-methyl-2-pyrrolidone was charged with the total mass of charged monomers (diamine component and (Total amount of carboxylic acid components) of 16% by mass was added, and the mixture was stirred at room temperature for 1 hour. To this solution, 384.38 g (1.00 mol) of CpODA was gradually added. The mixture was stirred at room temperature for 12 hours to obtain a uniform and viscous polyimide precursor solution (varnish A).

[Synthesis Example 2]
In a reaction vessel purged with nitrogen gas, 90.91 g (0.40 mol) of DABAN, 54.07 g (0.50 mol) of PPD and 36.84 g (0.10 mol) of BAPB were put, and N-methyl-2- To the pyrrolidone, 2972.56 g of the total amount of the charged monomers (total of the diamine component and the carboxylic acid component) of 16% by mass was added, and the mixture was stirred at room temperature for 1 hour. To this solution, 384.38 g (1.00 mol) of CpODA was gradually added. The mixture was stirred at room temperature for 12 hours to obtain a uniform and viscous polyimide precursor solution (varnish B).

[Synthesis Example 3]
20.02 g (0.10 mol) of 4,4′-ODA was placed in a reaction vessel purged with nitrogen gas, and N-methyl-2-pyrrolidone was charged with the total mass of charged monomers (total of diamine component and carboxylic acid component). Was added in an amount of 17% by mass, followed by stirring at room temperature for 1 hour. To this solution, 22.41 g (0.10 mmol) of PMDA-HS was gradually added. The mixture was stirred at room temperature for 12 hours to obtain a uniform and viscous polyimide precursor solution (varnish C).

[Synthesis Example 4]
In a reaction vessel purged with nitrogen gas, 32.02 g (0.10 mmol) of TFMB was charged, and N-methyl-2-pyrrolidone was added to the reaction vessel so that the total mass of the charged monomers (the sum of the diamine component and the carboxylic acid component) was 20 mass%. An appropriate amount of 287.79 g was added, and the mixture was stirred at room temperature for 1 hour. To this solution, 8.83 g (0.03 mol) of s-BPDA and 31.10 g (0.07 mol) of 6FDA were gradually added. The mixture was stirred at room temperature for 12 hours to obtain a uniform and viscous polyimide precursor solution (varnish D).

[Example 1]
0.07 g (0.50 mmol) of trimethyl phosphate and 0.07 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 33.76 g of varnish A obtained in Synthesis Example 1 (10 mmol based on the molecular weight of the repeating unit of the polyimide precursor in varnish A) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphate is 0.05 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Example 2]
0.14 g (1.00 mmol) of trimethyl phosphate and 0.14 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 33.76 g of varnish A obtained in Synthesis Example 1 (10 mmol based on the molecular weight of the repeating unit of the polyimide precursor in varnish A) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphate is 0.1 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Example 3]
0.28 g (2.00 mmol) of trimethyl phosphate and 0.28 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 33.76 g of varnish A obtained in Synthesis Example 1 (10 mmol based on the molecular weight of the repeating unit of the polyimide precursor in varnish A) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphate is 0.2 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Example 4]
0.56 g (4.00 mmol) of trimethyl phosphate and 0.56 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 33.76 g of varnish A obtained in Synthesis Example 1 (10 mmol based on the molecular weight of the repeating unit of the polyimide precursor in varnish A) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphate is 0.4 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Example 5]
0.25 g (2.00 mmol) of trimethyl phosphite and 0.25 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 33.76 g of varnish A obtained in Synthesis Example 1 (10 mmol based on the molecular weight of the repeating unit of the polyimide precursor in varnish A) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphite is 0.2 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Comparative Example 1]
The varnish A obtained in Synthesis Example 1 obtained by filtration with a PTFE membrane filter was applied to a glass substrate, and heated from room temperature to 410 ° C. on a glass substrate as it was under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize the imide. Then, a transparent and colorless 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Comparative Example 2]
0.20 g (2.00 mmol) of phosphoric acid and 0.20 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 33.76 g of varnish A obtained in Synthesis Example 1 (10 mmol based on the molecular weight of the repeating unit of the polyimide precursor in varnish A) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of phosphoric acid is 0.2 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Comparative Example 3]
0.65 g (2.00 mmol) of triphenyl phosphate and 0.65 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 33.76 g of varnish A obtained in Synthesis Example 1 (10 mmol based on the molecular weight of the repeating unit of the polyimide precursor in varnish A) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of triphenyl phosphate is 0.2 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Comparative Example 4]
0.27 g (1.00 mmol) of tributyl phosphate and 0.27 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 33.76 g of varnish A obtained in Synthesis Example 1 (10 mmol based on the molecular weight of the repeating unit of the polyimide precursor in varnish A) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of tributyl phosphate is 0.1 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

  Table 2-1 shows the results of measuring the properties of the polyimide film.

[Example 6]
0.14 g (1.00 mmol) of trimethyl phosphate and 0.14 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphate is 0.1 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 7]
0.28 g (2.00 mmol) of trimethyl phosphate and 0.28 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphate is 0.2 equivalent to 1 mole of the repeating unit of the polyimide precursor.

  A polyimide precursor solution filtered through a PTFE membrane filter is coated on a glass substrate, and is heated from room temperature to 410 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized, and 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 having a thickness of about 10 μm.

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

[Comparative Example 5]
The varnish B obtained in Synthesis Example 2 obtained by filtration with a PTFE membrane filter was applied to a glass substrate, and heated from room temperature to 410 ° C. on a glass substrate as it was under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize the varnish. Then, a transparent and colorless 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 having a thickness of about 10 μm.

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

Example 8
0.14 g (1.0 mmol) of diethyl phosphite and 0.14 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of diethyl phosphite is 0.1 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 9]
0.28 g (2.0 mmol) of diethyl phosphite and 0.28 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of diethyl phosphite is 0.2 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 10]
0.55 g (4.0 mmol) of diethyl phosphite and 0.55 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of diethyl phosphite is 0.4 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 11]
0.97 g (7.0 mmol) of diethyl phosphite and 0.60 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of diethyl phosphite is 0.7 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 12]
1.38 g (10.0 mmol) of diethyl phosphite and 0.60 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of diethyl phosphite is 1.0 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 13]
1.80 g (13.0 mmol) of diethyl phosphite and 0.60 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of diethyl phosphite is 1.3 equivalents per mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 14]
2.76 g (20.0 mmol) of diethyl phosphite and 0.60 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of diethyl phosphite is 2.0 equivalents per 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 15]
0.44 g (4.0 mmol) of dimethyl phosphite and 0.44 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of dimethyl phosphite is 0.4 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 16]
2.48 g (20.0 mmol) of trimethyl phosphite and 0.50 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphite is 2.0 equivalents per 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 17]
4.96 g (40.0 mmol) of trimethyl phosphite and 0.50 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphite is 4.0 equivalents per 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Comparative Example 6]
The varnish B obtained in Synthesis Example 2 obtained by filtration with a PTFE membrane filter was applied to a glass substrate, and heated from room temperature to 420 ° C. on a glass substrate as it was under a nitrogen atmosphere (oxygen concentration: 200 ppm or less). Then, a transparent and colorless 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 having a thickness of about 10 μm.

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

[Comparative Example 7]
0.31 g (1.0 mmol) of triphenyl phosphite and 0.31 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of triphenyl phosphite is 0.1 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Comparative Example 8]
1.24 g (4.0 mmol) of triphenyl phosphite and 1.24 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of triphenyl phosphite is 0.4 equivalent to 1 mole 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 is heated from room temperature to 420 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Example 18]
0.14 g (1.0 mmol) of trimethyl phosphate and 0.14 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 24.94 g of varnish C obtained in Synthesis Example 3 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish C) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphate is 0.1 equivalent to 1 mole 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 heated directly from room temperature to 400 ° C. on a glass substrate in a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize, and 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 having a thickness of about 10 μm.

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

[Comparative Example 9]
The varnish C obtained in Synthesis Example 3 obtained by filtration through a PTFE membrane filter was applied to a glass substrate, and heated from room temperature to 400 ° C. on a glass substrate as it was under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize the varnish. Then, a transparent and colorless 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 having a thickness of about 10 μm.

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

[Example 19]
0.28 g (2.0 mmol) of trimethyl phosphate and 0.28 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a uniform solution. 35.95 g of varnish D obtained in Synthesis Example 4 (10 mmol with respect to the molecular weight of the repeating unit of the polyimide precursor in varnish D) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide. A precursor solution was obtained. When calculated from the charged amount, the number of moles of trimethyl phosphate is 0.2 equivalent to 1 mole 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 is heated from room temperature to 370 ° C. on a glass substrate as it is under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to be thermally imidized. 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 having a thickness of about 10 μm.

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

[Comparative Example 10]
The varnish D obtained in Synthesis Example 4 obtained by filtration through a PTFE membrane filter was applied to a glass substrate, and heated from room temperature to 370 ° C. on a glass substrate as it was under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) to thermally imidize the imide. Then, a transparent and colorless 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 having a thickness of about 10 μm.

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

  From the results shown in Tables 2-1 and 2-2, phosphorus compounds (trimethyl phosphate, trimethyl phosphite, dimethyl phosphite, or phosphite) having a boiling point at 1 atm lower than the decomposition temperature and 350 ° C. or lower It can be seen that the polyimide obtained from the polyimide precursor composition containing (diethyl phosphate) has the same transparency as the polyimide obtained from the polyimide precursor composition containing no phosphorus compound, and has higher heat resistance ( Examples 1 to 5 and Comparative Example 1, Examples 6 to 17 and Comparative Examples 5 and 6, Example 18 and Comparative Example 9, Example 19 and Comparative Example 10). On the other hand, a polyimide containing a phosphorus compound (phosphoric acid, tributyl phosphate) whose boiling point at 1 atm is higher than the decomposition temperature, or a phosphorus compound (triphenyl phosphate, triphenyl phosphite) having a boiling point at 1 atm above 350 ° C The polyimide obtained from the precursor composition has lower heat resistance than the polyimide obtained from the polyimide precursor composition containing no phosphorus compound. Comparative Examples 1 and Comparative Examples 2, 3 to 4, Comparative Example 5, 6 and Comparative Examples 7 and 8)

  As described above, the polyimide obtained from the polyimide precursor composition of the present invention has excellent light transmittance and mechanical properties, high heat resistance, and also has a low coefficient of linear thermal expansion, The polyimide film of the present invention can be suitably used as a transparent substrate capable of forming fine and colorless circuits for use in displays and the like.

  According to the present invention, a polyimide precursor composition (solution composition containing a polyimide precursor), which is a polyimide excellent in transparency and mechanical properties and which can obtain a polyimide having higher heat resistance even with the same composition, and a polyimide A manufacturing method can be provided. Polyimide obtained from this polyimide precursor composition is highly transparent, has higher heat resistance, and has a low linear thermal expansion coefficient and is easy to form fine circuits. And a substrate for a solar cell or the like.

Claims (12)

It contains at least one of the repeating unit represented by the following chemical formula (1), the repeating unit represented by the following chemical formula (2), or the repeating unit represented by the following chemical formula (3), and is represented by the following chemical formulas (1) and (2) And a polyimide precursor having a content of other repeating units other than the repeating units represented by (3) and not more than 30 mol% based on all repeating units,
A polyimide precursor composition comprising a phosphorus atom and a phosphorus compound having a boiling point at 1 atm lower than a decomposition temperature and 350 ° C. or lower.

(In the formula, X ₁ is a tetravalent group having an alicyclic structure, Y ₁ is a divalent group having an aromatic ring, and R ₁ and R ₂ are each independently hydrogen, having 1 to 6 carbon atoms. Or an alkylsilyl group having 3 to 9 carbon atoms.)

(In the formula, X ₂ is a tetravalent group having an aromatic ring, Y ₂ is a divalent group having an alicyclic structure, and R ₃ and R ₄ are each independently hydrogen, having 1 to 6 carbon atoms. Or an alkylsilyl group having 3 to 9 carbon atoms.)

(Wherein, X ₃ is a tetravalent group having an aromatic ring, Y ₃ is a divalent group having an aromatic ring, provided that at least one of X ₃ and Y ₃ contains a fluorine atom. , R ₅ and R ₆ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.)   2. The polyimide precursor composition according to claim 1, wherein a boiling point of the phosphorus compound at 1 atm is 200 ° C. or less. 3.   3. The polyimide precursor composition according to claim 1, wherein the phosphorus compound is any one of trimethyl phosphate, trimethyl phosphite, dimethyl phosphite, and diethyl phosphite. 4.   The polyimide precursor composition according to claim 3, wherein the phosphorus compound is trimethyl phosphate.   In the polyimide precursor, the content of other repeating units other than the repeating units represented by the chemical formulas (1), (2), and (3) is 10 mol% or less based on all repeating units. The polyimide precursor composition according to any one of claims 1 to 4, characterized in that:   The polyimide precursor contains a repeating unit represented by the chemical formula (1), and the content of other repeating units other than the repeating unit represented by the chemical formula (1) is 30 mol% with respect to all the repeating units. The polyimide precursor composition according to claim 1, wherein:   7. The polyimide precursor according to claim 6, wherein the content of other repeating units other than the repeating unit represented by the chemical formula (1) is 10 mol% or less based on all repeating units. A polyimide precursor composition.   The polyimide precursor composition according to any one of claims 1 to 7, wherein the content of the phosphorus compound is 0.05 mol or more and less than 5 mol per 1 mol of the repeating unit of the polyimide precursor. .   A method for producing a polyimide, comprising heating the polyimide precursor composition according to claim 1 to imidize the polyimide precursor. A step of applying the polyimide precursor composition according to any one of claims 1 to 8 on a substrate,
Heat-treating the polyimide precursor composition on the substrate to imidize the polyimide precursor.   A polyimide film produced by the method according to claim 9. A substrate for a display, a touch panel, or a solar cell, comprising the polyimide film according to claim 11 .