KR20160091936A - Polyimide precursor composition, polyimide production method, polyimide, polyimide film, and substrate - Google Patents

Abstract

The present invention relates to a polyimide precursor composition containing a polyimide precursor and an imidazole-based compound, wherein the content of the imidazole-based compound is less than 4 moles per 1 mole of the repeating unit of the polyimide precursor.

Description

TECHNICAL FIELD The present invention relates to a polyimide precursor composition, a method for producing polyimide, a polyimide, a polyimide film, and a substrate,

The present invention relates to a solution composition (polyimide precursor composition) containing a polyimide precursor capable of obtaining a polyimide having small retardation in the thickness direction (retardation), excellent mechanical properties, and excellent transparency, and a process for producing a polyimide . The present invention also relates to a polyimide, a polyimide film, and a substrate which are excellent in transparency, small in retardation in the thickness direction, and excellent in mechanical properties.

2. Description of the Related Art In recent years, along with the advent of a highly information-oriented society, optical materials such as optical alignment films for liquid crystal display devices and protective films for color filters, such as optical fibers and optical waveguides in the field of optical communication, have been developed. Particularly in the field of display devices, there has been actively studied a plastic substrate which is lightweight and excellent in flexibility as a substitute for a glass substrate, and development of a display capable of bending or rounding. For this reason, there is a demand for a higher-performance optical material that can be used for such applications.

The aromatic polyimide is essentially colored yellowish brown by the formation of an intramolecular conjugate or a charge transfer complex. Therefore, as means for suppressing coloring, for example, introduction of fluorine atoms into a molecule, imparting flexibility to the main chain, introduction of a bulk group as a side chain, and the like inhibit intramolecular conjugation or formation of a charge transfer complex And a method of expressing transparency has been proposed.

Also, a method of expressing transparency by using a ring-cyclic or battery cyclic polyimide which does not form a charge-transfer complex in principle is also proposed.

For example, Patent Documents 1 to 3 disclose a ring-cyclic polyimide having high transparency using an aromatic tetracarboxylic acid dianhydride as a tetracarboxylic acid component and an alicyclic diamine as a diamine component.

Also, for example, Patent Documents 4 to 7 disclose various ring-cyclic polyimides having high transparency using alicyclic tetracarboxylic acid dianhydride as the tetracarboxylic acid component and aromatic diamine as the diamine component .

Non-Patent Document 1 discloses that a tetracarboxylic acid component such as norbornane-2-spiro-a-cyclopentanone-a'-spiro-2'-norbornane-5,5 ' '-Tetracarboxylic acid dianhydride is disclosed. Further, the norbornane-2-spiro-a-cyclopentanone-a'-spiro-2''-norbornane-5,5 '', 6,6 "-tetracarboxylic acid 2 It is described that an anhydride contains six kinds of stereoisomers. Patent Document 8 also discloses that, as a tetracarboxylic acid component, norbornane-2-spiro-a-cyclopentanone-a'-spiro-2'-norbornane-5,5 ' -Tetracarboxylic acid dianhydride. ≪ / RTI >

However, depending on the application, in particular, in the fields of display devices and the like, it is desired to lower the retardation in the thickness direction in addition to high transparency. There is a case that the color is not correctly displayed and the blurring of the color or the viewing angle is narrowed due to transmission of a film having a large retardation in the thickness direction. Therefore, in the fields of display devices and the like, a polyimide film having a small retardation in the thickness direction is required.

On the other hand, Patent Document 9 discloses a polyimide formed by heating a coating liquid formed by blending a polyimide precursor (polyamic acid) with an imidazoline-based compound and / or an imidazole-based compound. More specifically, in Example 1, a solution of polyamic acid obtained from 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride and 4,4'-diaminobiphenyl ether was added with 2,4 -Dimethylimidazoline was coated on the substrate and heated at 200 占 폚 for 1 hour to obtain an aromatic polyimide film having a thickness of 1000 占 (0.1 占 퐉). In Example 2, a solution prepared by adding 2-ethylimidazoline and 1,2-dimethylimidazole to a solution of a polyamic acid obtained from pyromellitic dianhydride and 4,4'-diaminobiphenyl ether was placed on a substrate And heated at 150 占 폚 for 1 hour to obtain an aromatic polyimide film having a film thickness of 800 占 (0.08 占 퐉). Patent Document 9 discloses that the addition of an imidazoline compound and / or an imidazole-based compound prevents significant coloration of brownish brown, thereby making it possible to obtain a liquid crystal display device having high transparency and high light transmittance. However, the liquid crystal display device using the polyimide coating (liquid crystal alignment film) of Example 1 had a light transmittance of 82% (polyimide film thickness: 0.1 占 퐉) and a polyimide coating film (liquid crystal alignment film) of Example 2 at a wavelength of 400 nm The liquid crystal display element used had a light transmittance of 400% at a wavelength of 400 nm (polyimide film thickness: 0.08 占 퐉), and this polyimide does not have sufficient transparency.

As a process for producing an aromatic polyimide having low transparency, Patent Document 10 discloses a process for producing a polyimide precursor resin and a polyimide precursor resin such as imidazole, N-methylimidazole and the like, in which a curing accelerator is dissolved in an organic polar solvent A method of forming a polyimide resin layer by applying a solution containing a polyimide precursor resin on a substrate and completing the formation of a polyimide resin layer by drying and imidization in a subsequent heat treatment within a range of 280 to 380 ° C, It is described that by using these curing accelerators, the thermal expansion coefficient can be controlled to be low. Patent Document 10 describes that it is preferable to use a curing accelerator having a boiling point of more than 120 ° C. and to select a curing accelerator having a boiling point that does not exceed the upper limit temperature of the heat treatment, For example, it is described that a curing accelerator having a temperature of 400 占 폚 or higher tends to have an influence on the function of the polyimide resin layer because the proportion of the curing accelerator remaining after the imidization in the polyimide resin layer increases.

Japanese Patent Application Laid-Open No. 2003-192787 Japanese Patent Application Laid-Open No. 2004-83814 Japanese Laid-Open Patent Publication No. 2008-308550 Japanese Patent Application Laid-Open No. 2003-168800 International Publication No. 2008/146637 Japanese Laid-Open Patent Publication No. 2002-69179 Japanese Patent Application Laid-Open No. 2002-146021 International Publication No. 2011/099518 Japanese Patent Application Laid-Open No. 61-267030 Japanese Laid-Open Patent Publication No. 2008-115378

 Polymer Journal, Vol. 68, No. 3, P. 127-131 (2011)

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has as its object to provide a polyimide excellent in transparency having a smaller retardation in the thickness direction even in the same composition or a polyimide having a small retardation in the thickness direction, (A solution composition containing a polyimide precursor) and a process for producing a polyimide, which can obtain a polyimide excellent also in the properties of a polyimide precursor.

The present invention relates to each of the following items.

1. A polyimide precursor comprising a polyimide precursor containing a repeating unit represented by the following formula (1) or a repeating unit represented by the following formula (2)

Containing compound,

Wherein the content of the imidazole compound is less than 4 moles relative to 1 mole of the repeating unit of the polyimide precursor.

[Chemical Formula 1]

(Wherein X < _{1 >} Is a quadrivalent group having an alicyclic structure, Y ₁ And R &_lt; ₂ > are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkyl silyl group having 3 to 9 carbon atoms.

(2)

(Wherein X ₂ is a tetravalent group having an aromatic ring, Y ₂ is a divalent group having an alicyclic structure, R ₃ and R ₄ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, 9 < / RTI >

2. The polyimide precursor composition according to item 1, wherein the polyimide obtained from the polyimide precursor composition has a light transmittance of at least 75% at a wavelength of 400 nm in a film having a thickness of 10 占 퐉.

3. The polyimide precursor composition according to item 1 or 2 above, wherein the content of the imidazole compound is 0.05 mol or more and 2 mol or less per mol of the repeating unit of the polyimide precursor.

4. The polyimide precursor composition according to any one of items 1 to 3, wherein the imidazole compound has a boiling point of less than 340 占 폚 at 1 atm.

Wherein the imidazole compound is at least one compound selected from the group consisting of 1,2-dimethylimidazole, 1-methylimidazole, 2-methylimidazole, 2-phenylimidazole, imidazole, And the polyimide precursor composition according to any one of claims 1 to 4.

6. A process for producing a polyimide precursor composition, characterized by heat-treating the polyimide precursor composition according to any one of items 1 to 5 at a maximum heating temperature of 350 DEG C to imidize the polyimide precursor.

7. A process for producing a polyimide precursor composition comprising the steps of applying the polyimide precursor composition described in any one of items 1 to 5 on a substrate,

A step of heat-treating the polyimide precursor composition on the substrate at a maximum heating temperature of 350 DEG C to imidize the polyimide precursor

Wherein the polyimide precursor is a polyimide precursor.

8. The process for producing a polyimide according to item 6 or 7, wherein the maximum heating temperature of the heat treatment exceeds 400 占 폚.

9. A polyimide produced by the method according to any one of items 6 to 8 above.

10. The polyimide according to item 9, characterized in that the light transmittance at a wavelength of 400 nm in a film having a thickness of 10 mu m is 75% or more.

11. A polyimide film produced by the method according to any one of items 6 to 8 above.

12. A substrate for a display, a touch panel, or a solar cell, which comprises the polyimide described in the above item 9 or 10, or the polyimide film described in the above item 11.

According to the present invention, it is possible to provide a polyimide excellent in transparency, a polyimide having a smaller retardation in the thickness direction even in the same composition, or a polyimide precursor having an excellent mechanical property and a high transparency, A composition (a solution composition containing a polyimide precursor), and a process for producing a polyimide.

The polyimide (polyimide of the present invention) obtained from the polyimide precursor composition of the present invention has a high transparency, a small retardation in the thickness direction, a low thermal expansion coefficient, and is easy to form a fine circuit. Can be preferably used. The polyimide of the present invention can also be preferably used for forming a substrate for a touch panel or a solar cell.

The polyimide precursor composition of the present invention contains a polyimide precursor and an imidazole-based compound containing at least one of repeating units represented by the above-mentioned formula (1) or repeating units represented by the above-mentioned formula (2) The content of the sol-based compound is less than 4 mol per 1 mol of the repeating unit of the polyimide precursor.

The polyimide obtained from the polyimide precursor containing the repeating unit represented by the above-mentioned formula (1) or the repeating unit represented by the above formula (2), that is, the ring-cyclic polyimide has high transparency. In the case of such a highly transparent polyimide, the use of additives which may cause coloring is not preferred. However, by adding the imidazole-based compound to the polyimide precursor composition at a ratio of less than 4 mol, preferably from 0.05 mol to 2 mol, per mol of the repeating unit of the polyimide precursor, A polyimide having a small retardation in the thickness direction can be obtained. That is, according to the present invention, a polyimide having a retardation in thickness direction can be obtained from a polyimide precursor having the same composition while maintaining high transparency. When an imidazole compound having a boiling point of less than 340 占 폚 at 1 atmosphere is used, the transparency of the obtained polyimide may be further improved.

In order to obtain polyimide with high transparency, it is generally considered to be preferable to heat-treat the polyimide precursor at a relatively low temperature to complete imidization. According to the present invention, however, , Particularly preferably 400 占 폚 or more, even if the polyimide precursor is imidized by heating treatment. As a result, since the maximum heating temperature of the heat treatment for imidization can be set to a high temperature exceeding 350 캜, particularly preferably to a high temperature exceeding 400 캜, the mechanical properties of the obtained polyimide are improved. That is, according to the present invention, polyimide having high transparency, small retardation in the thickness direction, and excellent mechanical properties can be obtained.

As described above, the polyimide precursor composition of the present invention contains a polyimide precursor containing at least one of repeating units represented by the above-mentioned formula (1) or repeating units represented by the above formula (2).

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

Examples of the tetracarboxylic acid component imparting the repeating unit of the above formula (1) include 1,2,3,4-cyclobutane tetracarboxylic acid, isopropylidenediphenoxy bisphthalic acid, cyclohexane-1 , 2,4,5-tetracarboxylic acid, [1,1'-non (cyclohexane)] -3,3 ', 4,4'-tetracarboxylic acid, [1,1'- )] - 2,3,3 ', 4'-tetracarboxylic acid, [1,1'-non (cyclohexane)] - 2,2', 3,3'-tetracarboxylic acid, (Cyclohexane-1,2-dicarboxylic acid), 4,4 '- (propane-2,2-diyl) bis (cyclohexane- (Cyclohexane-1,2-dicarboxylic acid), 4,4'-thiobis (cyclohexane-1,2-dicarboxylic acid), 4,4'-sulfonylbis (cyclohexane- Dicarboxylic acid), 4,4 '- (dimethylsilanediyl) bis (cyclohexane-1,2-dicarboxylic acid), 4,4' - (tetrafluoropropane- -Diyl) bis (cyclohexane-1,2-dicarboxylic acid), octahydropentalene-1,3,4,6-tetra Heptane-2,3,5,6-tetracarboxylic acid, 6- (carboxymethyl) bicyclo [2.2.1] heptane-2,3,5-tricarboxylic acid Acid, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octa-5-ene-2,3,7,8-tetracarboxylic acid, Tricyclo [4.2.2.02,5] decane-3,4,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] deca-7-ene-3,4,9,10-tetracarboxylic Tetracarboxylic acid, norbornane-2-spiro-a-cyclopentanone-a'-spiro-2 ', 4'- '-Norbornane 5,5' ', 6,6 "-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, Tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2t, 3t, 6c, 7c-tetracarboxylic acid or their tetracarboxylic acid 2 Anhydrides, tetracarboxylic acid silyl esters, tetracarboxylic acid esters , It may be a derivative, such as tetracarboxylic acid chloride. The tetracarboxylic acid component may be used singly or in combination of a plurality of species.

Examples of the diamine component giving the repeating unit of the above formula (1) include 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 (4-aminophenyl) terephthalamide, N, N'-p-phenylenebis (p- aminobenzamide), 4-aminophenoxy-4-diaminobenzoate, bis (P-aminobenzoate), bis (4-aminophenyl) - [1,1 '] thiophene, terephthalate, biphenyl-4,4'- dicarboxylic acid bis -Biphenyl] -4,4'-dicarboxylate, [1,1'-biphenyl] -4,4'-diyl bis (4-aminobenzoate), 4,4'-oxydianiline, 3 , 4'-oxydianiline, 3,3'-oxydianiline, p-methylenebis (phenylenediamine), 1,3-bis (4-aminophenoxy) benzene, Bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) Bis (4-aminophenyl) sulfone, 3, 4-aminophenyl) sulfone, 2, , 3'-bis (trifluoromethyl) benzidine, 3,3'-bis ((aminophenoxy) phenyl) propane, 2,2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane , Bis (4- (4-aminophenoxy) diphenyl) sulfone, bis (4- (3-aminophenoxy) diphenyl) sulfone, octafluorobenzidine, 3,3'-dimethoxy- Diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2-sulfone sulfone, 4- 4-aminoanilino) -6-amino-1,3,5-triazine, 2,4-bis (4-aminoanilino) -6- -Bis (4-aminoanilino) -6-ethylamino-1,3,5-triazine, 2,4-bis (4- Mino anilino) and the Lino-1,3,5-triazine-6-not. The diamine component may be used singly or in combination of plural kinds.

The polyimide precursor containing at least one of the repeating units represented by the above formula (1) may contain other repeating units other than the repeating unit represented by the above formula (1). The tetracarboxylic acid component and the diamine component for imparting other repeating units are not particularly limited and other known aromatic or aliphatic tetracarboxylic acids, known aromatic or aliphatic diamines can be used. Other tetracarboxylic acid components may be used alone, or a plurality of species may be used in combination. The other diamine components may be used singly or in combination of plural kinds.

The content of other repeating units other than the repeating unit represented by the above formula (1) is preferably 30 mol% or less, or 30 mol% or less, more preferably 20 mol% or less, Is preferably 10 mol% or less.

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

Examples of the tetracarboxylic acid component for imparting the repeating unit of the above formula (2) include 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 4- (2,5-dioxo 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 acid dianhydride, p-terphenyl-3,4,3'4'-tetracarboxylic acid 2 A tetracarboxylic acid dianhydride, a tetracarboxylic acid silyl ester, a tetracarboxylic acid ester, a tetracarboxylic acid chloride or the like can be used as the anhydride, biscarboxyphenyldimethylsilane, bisdicarboxyphenoxydiphenylsulfide and sulfonyldiphthalic acid. And derivatives thereof. The tetracarboxylic acid component may be used singly or in combination of a plurality of species.

Examples of the diamine component giving the repeating unit of the above formula (2) include 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4- 1,4-diamino-2-n-propylcyclohexane, 1,4-diamino-2-n-propylcyclohexane, 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, diaminooxy (Aminocyclohexyl) methane, bis (aminocyclohexyl) isopropylidene 6, bis (aminocyclohexyl) aminocycloheptane, diaminocyclododecane, Bis (3-aminophenoxy) -3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane, 6,6'-bis 3,3 ', 3'-tetramethyl-1,1'-spirobiindane. The diamine component may be used singly or in combination of plural kinds.

The polyimide precursor containing at least one of the repeating units represented by the above formula (2) may contain other repeating units other than the repeating unit represented by the above formula (2). The tetracarboxylic acid component and the diamine component for imparting other repeating units are not particularly limited and other known aromatic or aliphatic tetracarboxylic acids, known aromatic or aliphatic diamines can be used. Other tetracarboxylic acid components may be used alone, or a plurality of species may be used in combination. The other diamine components may be used singly or in combination of plural kinds.

The content of other repeating units other than the repeating units represented by the above-mentioned general formula (2) is preferably 30 mol% or less, or 30 mol% or less, more preferably 20 mol% or less, Is preferably 10 mol% or less.

The polyimide precursor may contain at least one repeating unit represented by the above-mentioned formula (1) and at least one repeating unit represented by the above-mentioned formula (2). In this case, the content of other repeating units other than the repeating units represented by the above-mentioned formulas (1) and (2) is preferably 30 mol% or less or 30 mol% or less, 20 mol% or less, more preferably 10 mol% or less.

In one embodiment, the polyimide precursor is preferably a polyimide precursor containing a repeating unit represented by the following formula (1-1), and is preferably a polyimide precursor represented by the following formula (1-2) and the following formula 1-3 ), More preferably a polyimide precursor having a total content of repeating units represented by formulas (1-2) and (1-3) of 80 mol% or more with respect to all repeating units Do.

(3)

(Wherein A 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.)

[Chemical Formula 4]

(Wherein A 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.)

[Chemical Formula 5]

(Wherein A 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.)

In the above formulas (1-1), (1-2) and (1-3), the 5th or 6th position of two norbornane rings (bicyclo [2.2.1] heptane) An acid group of one side reacts with an amino group to form an amide bond (-CONH-), a group represented by -COOR ₁ in which one side does not form an amide bond, or a group represented by -COOR ₂ . (I) the group represented by -COOR ₁ at the 5-position is substituted at the 6-position with the group represented by -COOR ₁ in the formula (1-1), the formula (1-2) and the formula CONH-, a group represented by -COOR ₂ at the 5 'position and a group represented by -CONH-A- at the 6' position, (ii) a group represented by -COOR ₁ at the 6-position, to have a group represented by -CONH-, "a group represented by -COOR ₂ in position, 6 ', 5''having a group represented by -CONH-A- in position, (iii) a group represented by -COOR ₁ in the 5 position, having a group represented by -CONH- position 6, 6 'having' a group represented by -COOR ₂ in position, the 5 'group represented by -CONH-A- on' position, (iv) represented by -COOR ₁ in the 6-position Group having a group represented by -CONH- at the 5-position, a group represented by -COOR ₂ at the 6 '' position and -CONH-A- at the 5 '-position.

The polyimide precursor is preferably a repeating unit represented by the formula (1-1) wherein A is a group represented by the following formula (1-A), more preferably a repeating unit represented by the formula (1-A) 2) and / or the repeating unit represented by the formula (1-3).

[Chemical Formula 6]

(Wherein m is an integer of 0 to 3 and n is an integer of 0 to 3. V, U, and T are each independently selected from the group consisting of a hydrogen atom, a methyl group, and a trifluoromethyl group Z and W each independently represent a direct bond or a group selected from the group consisting of groups represented by the formula: -NHCO-, -CONH-, -COO-, and -OCO-.

In other words, in some embodiments, the polyimide precursor is selected from the group consisting of norbornane-2-spiro-a-cyclopentanone-a'-spiro- '' -Tetracarboxylic acids and the like, more preferably trans-endo-endo-norbornane-2-spiro-a-cyclopentanone- ', 6,6' '- tetracarboxylic acids and / or cis-endo-endo-norbornane-2-spiro-a-cyclopentanone-a'-spiro- , 5 '', 6,6 '' - tetracarboxylic acids (such as tetracarboxylic acids and the like, tetracarboxylic acid and tetracarboxylic acid dianhydride, tetracarboxylic acid silylester, tetracarboxylic acid ester, A tetracarboxylic acid component containing a tetracarboxylic acid derivative such as a tetracarboxylic acid chloride, and a tetracarboxylic acid derivative such as a tetracarboxylic acid chloride, and a diamine component having an aromatic ring, more preferably a group represented by the formula (1-A) Formula (1-1), a polyamic acid obtained from a diamine component containing a diamine component which imparts a repeating unit represented by the formula (1-2) or (1-3).

Examples of the tetracarboxylic acid component imparting the repeating unit of the above formula (1-1) include norbornane-2-spiro-a-cyclopentanone-a'-spiro-2''-norbornane- , And 6,6 "-tetracarboxylic acids may be used alone or in combination of two or more. Examples of the tetracarboxylic acid component giving the repeating unit of the above formula (1-2) include trans-endo-endo-norbornane-2-spiro-a-cyclopentanone-a'-spiro- Borane-5,5 " and 6,6 " -tetracarboxylic acids may be used singly or in combination of plural kinds. Examples of the tetracarboxylic acid component for imparting the repeating unit of the above formula (1-3) include cis-endo-endo-norbornane-2-spiro-a-cyclopentanone-a'-spiro- Borane-5,5 " and 6,6 " -tetracarboxylic acids may be used singly or in combination of plural kinds.

In a polyimide precursor of a more preferable form, a tetracarboxylic acid component (trans-endo-endo-norbornane-2-spiro-a-cyclopentanone -α'-spiro-2 "'-norbornane-5,5", 6,6 "-tetracarboxylic acids, etc.), or repeating the above formula (1-3) (Cis-endo-endo-norbornane-2-spiro-a-cyclopentanone-a'-spiro-2 " -norbornane-5,5 ", 6 , 6 " -tetracarboxylic acids, etc.), or a tetracarboxylic acid component (trans-endo-endo-norbornane-2) - spiro-? -Cyclopentanone-? '- spiro-2 "-norbornane-5,5", 6,6 "-tetracarboxylic acids and the like) -3) to give a tetracarboxylic acid component (cis-endo-endono Spiro-α-cyclopentanone-α'-spiro-2 "-norbornane-5,5", 6,6 "-tetracarboxylic acids, etc.) May be used.

The polyimide precursor preferably has a total content of the repeating units represented by the above formulas (1-2) and (1-3) in the polyimide precursor of 80 mol% or more with respect to the total repeating units, 2) and the repeating unit represented by the above formula (1-3), and the repeating unit thereof is contained in the total repeating units in a total amount, preferably 80 mol% or more, more preferably 90 mol% or more, , More preferably at least 95 mol%, particularly preferably at least 99 mol%. (2) and the repeating unit represented by the above formula (1-3), and the repeating unit is contained in the total repeating units in a total amount, preferably 80 mol% or more, The coefficient of linear thermal expansion of the mead becomes small.

The diamine component giving the repeating unit of the above formula (1-1), or the repeating unit of the above formula (1-2) or the above formula (1-3) is a diamine which gives A a group represented by the above formula (1-A) Is preferably contained.

A diamine component giving a repeating unit represented by the formula (1-1) or the formula (1-2) or (1-3), which is a structure of the formula (1-A), has an aromatic ring, , The aromatic rings are connected to each other independently by a direct bond, an amide bond, or an ester bond. The connection position of the directional rings is not particularly limited, but the structure is linearized by bonding at the four positions with respect to the connecting group of the amino group or the aromatic ring, and the obtained polyimide may undergo low-line thermal expansion. The aromatic ring may be substituted with a methyl group or a trifluoromethyl group. The substitution position is not particularly limited.

The diamine component to which the repeating unit represented by formula (1-1), or the repeating unit represented by formula (1-2) or (1-3), in which A is the structure of formula (1-A) is not particularly limited, For example, p-phenylenediamine, m-phenylenediamine, benzidine, 3,3'-diamino-biphenyl, 2,2'-bis (trifluoromethyl) benzidine, N, N'-bis (4-aminophenyl) terephthalamide, N, N'-tetramethylbenzenediamine, aminophenoxy-4-diaminobenzoate, bis (4-aminophenyl) terephthalate, biphenyl-4,4'-dicarboxylic acid bis (4-aminophenyl) - [1,1'-biphenyl] -4,4'-dicarboxylate, p-phenylenebis (p- aminobenzoate) 1,1'-biphenyl] -4,4'-diylbis (4-aminobenzoate), and the like. And a plurality of species may be used in combination. Of these, p-phenylenediamine, m-tolidine, 4,4'-diaminobenzanilide, 4-aminophenoxy-4-diaminobenzoate, 2,2'-bis (trifluoromethyl) benzidine (4-aminophenyl) terephthalamide and biphenyl-4,4'-dicarboxylic acid bis (4-aminophenyl) ester are preferable, and p-phenylenediamine, 4, 4'-diaminobenzanilide, and 2,2'-bis (trifluoromethyl) benzidine are more preferable. By using p-phenylenediamine, 4,4'-diaminobenzanilide and 2,2'-bis (trifluoromethyl) benzidine as the diamine component, the obtained polyimide has both high heat resistance and high transmittance. These diamines may be used singly or in combination of plural kinds. In addition, o-tolidine is not preferable in view of high risk.

Examples of the diamine component giving the repeating unit of the above formula (1-1), or the repeating unit of the above formula (1-2) and the above formula (1-3) include diamines in which A is a group of the formula (1-A) Other diamines other than the component can be used in combination. As other diamine components, other aromatic or aliphatic diamines can be used. As other diamine components, for example, 4,4'-oxydianiline, 3,4'-oxydianiline, 3,3'-oxydianiline, bis (4-aminophenyl) sulfide, p- (Phenylenediamine), 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, Bis (4-aminophenyl) sulfone, 3,3-bis (4-aminophenoxy) phenyl] hexafluoropropane, 2,2- Bis (4-aminophenoxy) phenyl) propane, bis (4-aminophenoxy) - (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'- Phenyl, 4,4'-bis (3-aminophenoxy) Phenyl, 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-diamino- 2-sec-butylcyclohexane, 1,4-diamino-2-tert-butylcyclohexane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, Butane, 1,4-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane, diaminobicycloheptane, diaminomethylbicycloheptane, diaminooxybicycloheptane, diaminomethyloxy (Aminocyclohexyl) methane, bis (aminocyclohexyl) isopropylidene 6,6'-bis (3-aminophenoxy) aminocycloheptane, isophoronediamine, diaminotricyclodecane, diaminomethyltricyclodecane, bis ) -3,3,3 ', 3 ' -tetramethyl-1 , 1'-spirobiindane, 6,6'-bis (4-aminophenoxy) -3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane, and derivatives thereof And may be used alone, or a plurality of species may be used in combination.

The polyimide precursor of the present invention preferably contains at least one repeating unit of the above formula (1-1) wherein A is represented by the above formula (1-A), more preferably A is a repeating unit of the above formula (1-A) , At least one repeating unit of the above formula (1-2) and / or at least one repeating unit of the above formula (1-3) wherein A is represented by the above formula (1-A) . In other words, when the diamine component giving the repeating unit of the above formula (1-1), more preferably the repeating unit of the above formula (1-2) and the above formula (1-3) A). ≪ / RTI > The diamine component giving A in the above formulas (1-2) and (1-3) is preferably a repeating unit of the above formula (1-1), more preferably a repeating unit of the above formula (1-A) , The heat resistance of the obtained polyimide is improved.

The polyimide precursor of the present invention is a polyimide precursor of the formula (1-A) or the formula (1-A) in 100 mol% of the diamine component giving A in the above formula (1-2) ) Is preferably 50 mol% or more, more preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and still more preferably 90 mol% or more, And particularly preferably 100 mol%. In other words, when A represents the ratio of at least one of the repeating units of the formula (1-1) or the repeating units of the formulas (1-2) and (1-3), which is the structure of the formula (1-A) , Preferably 50 mol% or more, more preferably 70 mol% or more, of the total repeating units represented by the above formula (1-1) or the above formulas (1-2) and (1-3) , More preferably 80 mol% or more, further preferably 90 mol% or more, particularly preferably 100 mol%. When the ratio of the diamine component giving the structure of the formula (1-A) is smaller than 50 mol%, the coefficient of linear thermal expansion of the obtained polyimide may be increased. In one embodiment, from the viewpoint of the mechanical properties of the obtained polyimide, the diamine component giving A in the formula (1-1) or the formula (1-2) and the formula (1-3) is 100 mol% , The proportion of the diamine component giving the structure of the above formula (1-A) is preferably 80 mol% or less, more preferably 90 mol% or less or 90 mol% or less in total. For example, it is possible to use other aromatic or aliphatic diamines such as 4,4'-oxydianiline or the like with a repeating unit of the above formula (1-1) or the above formula (1-2) and the above formula (1-3) The diamine component may be used in an amount of 100 mol%, preferably less than 20 mol%, more preferably less than 10 mol%, and more preferably less than 10 mol%.

In one embodiment, the polyimide precursor containing the repeating unit represented by the above formula (1-1) of the present invention is a repeating unit of the formula (1-1) wherein A is represented by the above formula (1-A) May be preferably contained in at least two species. In one embodiment, the polyimide precursor containing the repeating unit represented by the above formula (1-2) and / or the repeating unit represented by the above formula (1-3) of the present invention is represented by the formula (1-A (1-2) or (1-2), which is a repeating unit represented by the following general formula (1). In other words, the diamine component giving the repeating unit of the above formula (1-1) or the diamine component giving the repeating unit of the above formula (1-2) and the above formula (1-3) And at least two diamine components which give a structure of the formula (1-A). A diamine component giving a structure represented by the above formula (1-A), or a diamine component giving A in the above formula (1-2) and the above formula (1-3) (That is, a polyimide having a high transparency and a low coefficient of linear thermal expansion can be obtained).

The polyimide precursor of the present invention may contain at least two repeating units of the above formula (1-2) wherein A is the structure of the above formula (1-A) (1-2), wherein A is the structure of the above formula (1-A), and the repeating unit of the above formula (1-2) And at least one repeating unit represented by the above formula (1-3) wherein A is the structure of the above formula (1-A).

In one embodiment, the polyimide precursor of the present invention is a polyimide precursor,

(i) A is a group represented by any one of the above formulas (1) and (2), wherein m and / or n is 1 to 3 and Z and / or W are each independently -NHCO-, -CONH-, -COO-, (I) of the above formula (1-1), preferably the repeating unit (I) of the above formula (1-2) and the above formula (1-3)

(1-A) wherein A is a structure of the above formula (1-A) wherein m and n are 0, or m and / or n is 1 to 3, and Z and W are direct bonds; (1-1), preferably the repeating unit (II) of the formula (1-2) and the repeating unit (II-3)

In this embodiment, examples of the repeating unit (I) include repeating units of the above formula (1-1) wherein A is represented by any one of the following formulas (D-1) to (D-3) And more preferably a repeating unit of the above formula (1-1) wherein A is represented by any one of the following formulas (D-1) to (D-2). The diamine component giving the repeating unit of the above formula (1-1) wherein A is represented by the following formula (D-1) or (D-2) is 4,4'-diaminobenzanilide, The diamine component giving the repeating unit of the above formula (1-1) wherein A is represented by the following formula (D-3) is bis (4-aminophenyl) terephthalate, and these diamines may be used alone , Or a combination of plural species may be used.

(7)

In this embodiment, examples of the repeating unit (II) include repeating units represented by the formula (1-1) wherein A is represented by any one of the following formulas (D-4) to , More preferably a repeating unit of the above formula (1-1) wherein A is represented by any one of the following formulas (D-4) to (D-5). The diamine component giving the repeating unit of the above formula (1-1) wherein A is represented by the following formula (D-4) is p-phenylenediamine and A is represented by the following formula (D-5) Wherein the diamine component giving the repeating unit of the formula (1-1) is 2,2'-bis (trifluoromethyl) benzidine and A is represented by the following formula (D-6) 1) is m-tolidine, and these diamines may be used alone or in combination of plural kinds.

[Chemical Formula 8]

In the polyimide precursor of this embodiment, the proportion of one or more of the above-mentioned repeating units (I) is, in total, 30 mol% or more and 70 mol% or less in the total repeating units represented by the above formula (1-1) It is preferable that the proportion of one or more kinds of the repeating units (II) is, in total, from 30 mol% to 70 mol% of the total repeating units represented by the above formula (1-1) Of the repeating unit (II) is at least 40 mol% or more and 60 mol% or less of the total repeating units represented by the formula (1-1) ) Is particularly preferably from 40 mol% to 60 mol%. In one embodiment, the proportion of the repeating unit (I) in the total repeating units represented by the above formula (1-1) is more preferably less than 60 mol%, more preferably not more than 50 mol% , And particularly preferably 40 mol% or less. In one embodiment, the other repeating unit represented by the above-mentioned formula (1-1) (for example, A has a plurality of aromatic rings other than the repeating unit (I) and the repeating unit (II) Is preferably 20 mol% or less, more preferably 10 mol% or less, and most preferably 10 mol% or less, of all the repeating units represented by the above formula (1-1) , And particularly preferably less than 10 mol%. In one embodiment, the proportion of one or more of the repeating units (I) is 20 mol% or more and 80 mol% or less of the total repeating units represented by the formula (1-1) It is preferable that the proportion of one or more of the repeating units (II) is, in total, 20 mol% or more and 80 mol% or less among the total repeating units represented by the above formula (1-1).

In one embodiment, the polyimide precursor containing the repeating unit of the above formula (1-1), or the repeating unit of the above formula (1-2) and / or the repeating unit of the above formula (1-3) -1), or a diamine component (the repeating unit of the above formula (1-1)) or the repeating unit of the above formula (1-2) and the above formula (1-A)) having a repeating unit represented by the general formula (1-A) contains at least two kinds of diamine components giving the structure of the above formula (1-A), wherein one of them is a 4,4'-diaminobenzanilide . The diamine component imparting A in the above formula (1-1) or the above formula (1-2) and the above formula (1-3) is at least two kinds of diamine components giving the structure of the above formula (1-A) And one of them is 4,4'-diaminobenzanilide, polyimide having both high transparency and low heat expansion and high heat resistance is obtained.

In one embodiment, the polyimide precursor containing the repeating unit of the above formula (1-1), or the repeating unit of the above formula (1-2) and / or the repeating unit of the above formula (1-3) -1), or a diamine component (the repeating unit of the above formula (1-1)) or the repeating unit of the above formula (1-2) and the above formula (Diamine component giving a repeating unit of the formula (1-3)) is at least one selected from the group consisting of 2,2'-bis (trifluoromethyl) benzidine and p-phenylenediamine, It is particularly preferable to contain anilide. By combining these diamine components, a polyimide having high transparency, low heat expansion, and heat resistance is obtained.

In this embodiment, the diamine component (the repeating unit of the above-mentioned formula (1-1) or the repeating unit of the above formula (1-1)) which gives the above formula (1-1) The diamine component giving the repeating units of the above formulas (1-2) and (1-3)) preferably contains 20 mol% or more and 80 mol% or less of 4,4'-diaminobenzanilide , More preferably 20 mol% or more and 80 mol% or less in either or both of p-phenylenediamine and 2,2'-bis (trifluoromethyl) benzidine, (B) a polyimide film which contains 4,4'-diaminobenzanilide in an amount of not less than 30 mol% and not more than 70 mol%, and further contains at least one of p-phenylenediamine and 2,2'-bis (trifluoromethyl) , More preferably 30 mol% or more and 70 mol% or less, and particularly preferably 4,4'-diaminobenzanilide 40 mol% or more and 60 mol% or less in any one or both of p-phenylenediamine and 2,2'-bis (trifluoromethyl) benzidine, Is more preferable. Diaminobenzanilide as a diamine component imparting A in the formula (1-1) or the formula (1-2) and the formula (1-3) in an amount of 30 mol% or more and 70 mol% Or more and 30 mol% or more and 70 mol% or less in either one or both of p-phenylenediamine and 2,2'-bis (trifluoromethyl) benzidine, Polyimide having heat-expandability and heat-resistance can be obtained. In one embodiment, the diamine component (the repeating unit of the above formula (1-1) or the repeating unit of the above formula (1-1)) which gives the above formula (1-1) or A in the above formulas As the diamine component giving the repeating units of the above formulas (1-2) and (1-3)), it is more preferable to contain less than 60 mol% of 4,4'-diaminobenzanilide, more preferably 50 mol % Or less, and particularly preferably 40 mol% or less.

The polyimide precursor of the present invention may contain other repeating units other than the repeating units represented by the above formula (1-1) or the repeating units represented by the above formulas (1-2) and (1-3).

As the tetracarboxylic acid component for imparting other repeating units, other aromatic or aliphatic tetracarboxylic acids may be used. For example, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 4- (2,5-dioxotetrahydrofuran-3-yl) Hydroxynaphthalene-1,2-dicarboxylic acid, pyromellitic acid, 3,3 ', 4,4'-benzophenonetetracarboxylic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, (3,4-dicarboxyphenyl) sulfone dianhydride, m-terphenyl-3,4,3, 4,3'-biphenyltetracarboxylic acid, 4,4'-oxydiphthalic acid, ', 4'-tetracarboxylic acid dianhydride, p-terphenyl-3,4,3', 4'-tetracarboxylic acid dianhydride, biscarboxyphenyldimethylsilane, bisdicarboxyphenodydiphenylsulfide, sulfo 1,2,4-cyclobutanetetracarboxylic acid, isopropylidene diphenoxy bisphthalic acid, cyclohexane-1,2,4,5-tetracarboxylic acid, [1,1'-bis (Cyclohexane)] -3,3 ', 4,4'-tetracarboxylic acid, [1,1'-non (cyclohexane)] - 2,3,3' 1,1'-bis (cyclohexane)] - 2,2 ', 3,3'-te (Cyclohexane-1,2-dicarboxylic acid), 4,4'- (propane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid (Cyclohexane-1,2-dicarboxylic acid), 4,4'-thiobis (cyclohexane-1,2-dicarboxylic acid), 4,4'-oxybis (Cyclohexane-1,2-dicarboxylic acid), 4,4'- (dimethylsilanediyl) bis (cyclohexane-1,2-dicarboxylic acid), 4,4'- (Tetrafluoropropane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), octahydropentalene-1,3,4,6-tetracarboxylic acid, bicyclo [2.2. Heptane-2,3,5-tricarboxylic acid, bicyclo [2.2.2] heptane-2,3,5,6-tetracarboxylic acid, 6- (carboxymethyl) bicyclo [ Octane-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octa-5-ene-2,3,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] Decane-3,4,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] deca-7-ene-3,4,9,10-tetracarboxylic acid , 9-oxatricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene- Derivatives such as 2c, 3c, 6c, 7c-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2t, 3t, 6c, 7c-tetracarboxylic acid , And acid anhydrides thereof. These acid anhydrides may be used singly or in combination. Of these, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid, (4arH , 8cH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid, (4arH, 8acH) Derivatives such as dimethanonaphthalene-2t, 3t, 6c, 7c-tetracarboxylic acid and the like, and acid dianhydrides thereof are more preferable because of easy production of polyimide and excellent heat resistance of the obtained polyimide. These acid dianhydrides may be used singly or in combination of plural kinds.

In the case of the polyimide precursor containing the repeating unit represented by the above formula (1-2) and / or the above formula (1-3), the cis-endo-endo-norbornene as the tetracarboxylic acid component imparting another repeating unit Spiro-? -Cyclopentanone-? '- spiro-2 "-norbornane-5,5", 6,6 "-tetracarboxylic acids and the like, and trans-endo-endo -Norbornene-2-spiro- [alpha] -cyclopentanone-a'-spiro-2 " -norbornane-5,5 ", 6,6 " -tetracarboxylic acids, Spiro-? -Cyclopentanone-? '- spiro-2 "-norbornane-5,5", 6,6 "-tetracarboxylic acids and the like (for example, Spiro- [alpha] -cyclopentanone-alpha ' -spiro-2 " -norbornane-5,5 ", 6,6 "- tetracarboxylic acid dianhydride) May be used.

The diamine component giving another repeating unit may be a diamine component that gives the structure of the above formula (1-A). In other words, when the repeating unit represented by the above formula (1-1) wherein A is the structure of the above formula (1-A), or the repeating unit of the above formula (1-1) (1-2) and diamines exemplified as the diamine component giving the repeating unit of the above formula (1-3). These diamines may be used singly or in combination of plural kinds.

As the diamine component giving another repeating unit, other aromatic or aliphatic diamines can be used. (4-aminophenyl) sulfide, p-methylenebis (phenylenediamine), p-methylenebis (phenylenediamine) Benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2- Bis (4-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, bis (Phenyl) propane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, bis 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-dimethoxy- 4,4'-diaminobiphenyl, 9,9-bis (4-aminophenyl) fluorene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'- '-Bis (3-aminophenoxy) biphenyl, 1,4-diaminocyclo Diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propylcyclohexane, 1,4-diamino-2-methylcyclohexane, 2-n-butylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino-2-sec-butylcyclohexane , 1,4-diamino-2-tert-butylcyclohexane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, 1,3-diaminocyclobutane, 1,4- Methyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane, diaminobicycloheptane, diaminomethylbicycloheptane, diaminooxybicycloheptane, diaminomethyloxybicycloheptane, isophoronediamine, (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, and derivatives thereof, and they may be used singly or in combination of plural species .

The synthesis method of norbornane-2-spiro- [alpha] -cyclopentanone- [alpha] ' -spiro-2 " -norbornane-5,5 ", 6,6 " -tetracarboxylic acids, , Although not particularly limited, can be synthesized by the method described in Patent Document 8 or the like. As described in Non-Patent Document 1, various kinds of stereoisomers may be contained depending on the synthesis method. Spiro-? -Cyclopentanone-? '- spiro-2 "-norbornane-5,5", 6,6 "-tetracarboxylic acids, or the like, or an intermediate thereof Column or the like, the stereoisomer can be used alone or in the form of a mixture of various species.

trans-endo-endo-norbornane-2-spiro- [alpha] -cyclopentanone- [alpha] ' -spiro-2 " -norbornane-5,5 ", 6,6 " -tetracarboxylic acids , And cis-endo-endo-norbornane-2-spiro- [alpha] -cyclopentanone-a'-spiro-2 " -norbornane-5,5 ", 6,6 & Spiro-? -Cyclopentanone? '- spiro-2' '- norbornane-5,5' ', 6,6' '- spiro- -Tetracarboxylic acids, and the like, or an intermediate thereof by a column or the like.

When the tetracarboxylic acid component and the diamine component contain an isomer, the isomer may be isolated and used for polymerization or the isomer 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 above formula (1) and R ₃ and R ₄ in the above formula (2) are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms Or an alkylsilyl group having 3 to 9 carbon atoms. R ₁ and R ₂ , R ₃ and R ₄ can change the kind of the functional group and the introduction ratio of the functional group by the production method described below.

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

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

When R ₁ and R ₂ , R ₃ and R ₄ are alkylsilyl groups having 3 to 9 carbon atoms, solubility of the polyimide precursor tends to be excellent. In this case, it is more preferable that R ₁ and R ₂ , R ₃ and R ₄ are a trimethylsilyl group or a t-butyldimethylsilyl group.

R ₁ and R ₂ , R ₃ and R ₄ each have an introduction rate of not less than 25%, preferably not less than 50%, more preferably not less than 75%, in the case of introduction of an alkyl group or an alkylsilyl group, Or more may be an alkyl group or an alkylsilyl group.

The polyimide precursor of the present invention, R ₁ and R _2, R ₃ and R ₄ is by taking the chemical structure, 1) a polyamic acid (R ₁ and R _2, R ₃ and R ₄ is hydrogen), 2) a poly amide esters (at least a portion of R ₁ and R _2, R ₃ and R ₄ alkyl group), 3), 4) a polyamic acid silyl ester (R ₁ and R _2, R ₃ and R ₄ at least some of the alkylsilyl group ). The polyimide precursor of the present invention can be easily produced by the following production method for each classification. However, the method for producing the polyimide precursor of the present invention is not limited to the following production method.

1) Polyamic acid

The polyimide precursor of the present invention is a polyimide precursor having a molar ratio of the tetracarboxylic acid dianhydride and the diamine component as the tetracarboxylic acid component in the solvent to the diamine component relative to the tetracarboxylic acid component [mol of the diamine component / tetra The molar number of the carboxylic acid component] of the polyimide precursor solution composition is preferably from 0.90 to 1.10, more preferably from 0.95 to 1.05, for example, while suppressing imidization at a relatively low temperature of 120 DEG C or less, .

More specifically, the diamine is dissolved in an organic solvent, the tetracarboxylic acid dianhydride is gradually added while stirring the solution, and the solution is stirred at a temperature of 0 to 120 ° C, preferably 5 to 80 ° C By stirring for 1 to 72 hours, a polyimide precursor is obtained. When the reaction is carried out at 80 占 폚 or higher, there is a possibility that the polyimide precursor can not be stably produced because the molecular weight varies depending on the temperature history at the time of polymerization and the imidization proceeds by heat. The order of addition of the diamine and the tetracarboxylic acid dianhydride in the above production method is preferable because the molecular weight of the polyimide precursor tends to rise. In addition, the order of addition of the diamine and the tetracarboxylic acid dianhydride in the above-described production method can be reversed, and the precipitate is preferably reduced.

When the molar ratio of the tetracarboxylic acid component to the diamine component is excessive, a carboxylic acid derivative in an amount substantially equivalent to the excess moles of the diamine component is added, if necessary, and the tetracarboxylic acid component and the diamine component Can be approximated to approximately equivalent. Examples of the carboxylic acid derivative herein include a tetracarboxylic acid which does not substantially increase the viscosity of the polyimide precursor solution, that is substantially not involved in molecular chain extension, or a tricarboxylic acid which functions as a terminal terminator and anhydrides thereof, Dicarboxylic acid and its anhydride are preferable.

2) Polyamide acid ester

The tetracarboxylic acid 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 diester dicarboxylic acid chloride. The polyimide precursor is obtained by stirring the diester dicarboxylic acid chloride and the diamine at a temperature of -20 to 120 ° C, preferably -5 to 80 ° C for 1 to 72 hours. When the reaction is carried out at 80 占 폚 or higher, there is a possibility that the polyimide precursor can not be stably produced because the molecular weight varies depending on the temperature history at the time of polymerization and the imidization proceeds by heat. Also, a polyimide precursor can be easily obtained by dehydrating and condensing a diester dicarboxylic acid and a diamine using a phosphorus-containing condensing agent, a carbodiimide condensing agent or the like.

Since the polyimide precursor obtained by this method is stable, it is also possible to carry out refining such as re-precipitation by adding a solvent such as water or alcohol.

3) Polyamidic acid silyl ester (indirect method)

A silylating agent is reacted with a diamine 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, the tetracarboxylic acid dianhydride is gradually added while stirring, and the mixture is stirred at 0 to 120 ° C, preferably 5 to 80 ° C for 1 to 72 hours , A polyimide precursor is obtained. When the reaction is carried out at 80 占 폚 or higher, there is a possibility that the polyimide precursor can not be stably produced because the molecular weight varies depending on the temperature history at the time of polymerization and the imidization proceeds by heat.

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

An amine catalyst such as pyridine, piperidine or triethylamine can be used for the silylation reaction of the diamine in order to accelerate the reaction. This catalyst can be used as it is as a polymerization catalyst for the polyimide precursor.

4) Polyamide acid silyl ester (direct method)

The polyamic acid solution obtained in the method 1) and the silylating agent are mixed and stirred at 0 to 120 캜, preferably 5 to 80 캜 for 1 to 72 hours to obtain a polyimide precursor. When the reaction is carried out at 80 占 폚 or higher, there is a possibility that the polyimide precursor can not be stably produced because the molecular weight varies depending on the temperature history at the time of polymerization and the imidization proceeds by heat.

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

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

Examples of the solvent to be used for preparing the polyimide precursor include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethylacetamide is particularly preferable. However, when the raw material monomer component and the resulting polyimide precursor are dissolved, any kind of solvent can be used without any problem So that the structure is not particularly limited. Examples of the solvent include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone,? -Butyrolactone,? -Valerolactone,? -Valerolactone, Cyclic ester solvents such as lactone, -caprolactone and -methyl- -butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, glycol solvents such as triethylene glycol, m-cresol, p-cresol, Phenol-based solvents such as 3-chlorophenol and 4-chlorophenol, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethylsulfoxide and the like are preferably employed. It is also possible to use other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, But are not limited to, benzoic acid, benzoic acid, benzoic acid, benzoic acid, benzoic acid, benzoic acid, benzoic acid, isophthalic acid, Methyl ethyl ketone, acetone, butanol, ethanol, xylene, toluene, chlorbenzene, terpene, mineral spirits, and petroleum naphtha type solvents. Further, a plurality of kinds of solvents may be used in combination.

In the present invention, the logarithmic viscosity of the polyimide precursor is not particularly limited, but the logarithmic viscosity in the N, N-dimethylacetamide solution at a concentration of 0.5 g / dl at 30 캜 is preferably 0.2 dl / g or more, Is preferably 0.3 dl / g or more, particularly preferably 0.4 dl / g or more. When the logarithmic viscosity is 0.2 dl / g or more, the molecular weight of the polyimide precursor is high, and the obtained polyimide has excellent mechanical strength and heat resistance.

The polyimide precursor composition of the present invention contains a polyimide precursor and an imidazole-based compound, and can be prepared by adding an imidazole-based compound to a polyimide precursor solution or solution composition obtained by the above production method. If necessary, the solvent may be removed or added, or a desired component other than the imidazole compound may be added. It is also possible to add a tetracarboxylic acid component (tetracarboxylic acid dianhydride, etc.), a diamine component and an imidazole compound to the solvent, react the tetracarboxylic acid component with the diamine component in the presence of an imidazole compound, The polyimide precursor composition of the present invention (a solution composition containing a polyimide precursor and an imidazole-based compound) can be obtained.

The imidazole-based compound used in the present invention is not particularly limited as long as it is a compound having an imidazole skeleton. By adding an imidazole-based compound, a polyimide having a small thickness direction retardation is obtained.

In any of the embodiments, it is preferable to use a compound having a boiling point of less than 340 ° C, preferably not more than 330 ° C, more preferably not more than 300 ° C, particularly preferably not more than 270 ° C at 1 atm as the imidazole compound desirable. By adding an imidazole compound having a boiling point of less than 340 deg. C, preferably not more than 330 deg. C, more preferably not more than 300 deg. C, particularly preferably not more than 270 deg. C at 1 atmosphere, polyimide having higher transparency is obtained There is a case.

Examples of the imidazole compound used in the present invention include, but are not limited to, 1,2-dimethylimidazole, 1-methylimidazole, 2-methylimidazole, 2-phenylimidazole, imidazole, Benzoimidazole and the like. Methylimidazole (boiling point at 1 atm: 198 deg. C), 2-methylimidazole (boiling point at 1 atm: 205 deg. C), 2-methylimidazole (Boiling point: 268 占 폚), imidazole (boiling point at 1 atmosphere: 256 占 폚), and 1,2-dimethylimidazole and 1-methylimidazole are particularly preferable. The imidazole-based compound may be used singly or in combination of plural species.

In the present invention, the content of the imidazole-based compound in the polyimide precursor composition is less than 4 moles per 1 mole of the repeating unit of the polyimide precursor. When the content of the imidazole-based compound is 4 mol or more per 1 mol of the repeating unit of the polyimide precursor, the storage stability of the polyimide precursor composition deteriorates. The content of the imidazole-based compound is preferably 0.05 mol or more with respect to 1 mol of the repeating unit of the polyimide precursor, and is preferably 2 mol or less per mol of the repeating unit of the polyimide precursor. Here, 1 mole of the repeating unit of the polyimide precursor corresponds to 1 mole of the tetracarboxylic acid component.

The polyimide precursor composition of the present invention usually contains a solvent. As the solvent used in the polyimide precursor composition of the present invention, there is no problem when the polyimide precursor is dissolved, and the structure thereof is not particularly limited. Examples of the solvent include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone,? -Butyrolactone,? -Valerolactone, a cyclic ester solvent such as? -caprolactone,? -caprolactone and? -methyl-? -butyrolactone, a carbonate solvent such as ethylene carbonate and propylene carbonate, a glycol solvent such as triethylene glycol, m-cresol, p Phenol-based solvents such as cresol, 3-chlorophenol and 4-chlorophenol, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethylsulfoxide and the like are preferably employed. It is also possible to use other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, But are not limited to, benzoic acid, benzoic acid, benzoic acid, benzoic acid, benzoic acid, benzoic acid, benzoic acid, isophthalic acid, Methyl ethyl ketone, acetone, butanol, ethanol, xylene, toluene, chlorbenzene, terpene, mineral spirits, and petroleum naphtha type solvents. A plurality of these may be used in combination. As the solvent of the polyimide precursor composition, the solvent used in preparing the polyimide precursor may be used 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 By mass or more. In general, the total amount of the tetracarboxylic acid component and the diamine component is preferably 60 mass% or less, more preferably 50 mass% or less, based on the total amount of the solvent, the tetracarboxylic acid component, and the diamine component. This concentration is a concentration that approximates to the solid content concentration originating from the polyimide precursor. However, when the concentration is too low, it is difficult to control the film thickness of the polyimide film obtained when the polyimide film is produced, for example have.

In the present invention, the viscosity (rotational viscosity) of the polyimide precursor composition is not particularly limited, but a rotational viscosity measured at a temperature of 25 DEG C and a shear rate of 20 sec < ^-1 > Pa · sec is preferable, and 0.1 to 100 Pa · sec is more preferable. If necessary, a tin-plasticity may be imparted. When the viscosity is within the above-mentioned range, it is easy to handle, and the film is suppressed from being cratered and the leveling property is excellent when coating or film formation is carried out.

The polyimide precursor composition of the present invention may contain, if necessary, a chemical imidization agent (an acid anhydride such as acetic anhydride, an amine compound such as pyridine or isoquinoline), an antioxidant, a filler (inorganic particles such as silica) , A coupling agent such as a pigment and a silane coupling agent, a primer, a flame retardant, a defoaming agent, a leveling agent, a rheology control agent (flow aid), a release agent and the like.

The polyimide of the present invention can be obtained by imidizing the polyimide precursor composition of the present invention as described above (i.e., dehydrating and cyclizing the polyimide precursor). The method of imidization is not particularly limited, and a known method of heat imidization or chemical imidization can be suitably applied. The form of the obtained polyimide is preferably a film, a laminate of a polyimide film and another substrate, a coating film, a powder, a bead, a molded article, a foam, and the like.

In the present invention, it is preferable that the polyimide precursor composition is subjected to a heat treatment at a maximum heating temperature of 350 DEG C or higher to imidize the polyimide precursor. The maximum heating temperature of the heat treatment for imidization is more preferably higher than 380 ° C, and particularly preferably higher than 400 ° C. By setting the maximum heating temperature of the heat treatment for imidization to a temperature higher than 350 ° C, more preferably higher than 380 ° C, particularly preferably higher than 400 ° C, the mechanical properties of the obtained polyimide . The upper limit of the maximum heating temperature in the heat treatment is not particularly limited, but is preferably 500 ° C or lower.

For example, the polyimide precursor composition of the present invention may be applied and softened on a substrate, and the polyimide precursor composition on the substrate may be heated to a temperature higher than 350 DEG C, more preferably higher than 380 DEG C, particularly preferably 400 DEG C The polyimide can be preferably prepared by heat-treating the polyimide precursor at an excess temperature to imidize the polyimide precursor. The heating profile is not particularly limited and can be appropriately selected. However, from the viewpoint of productivity, it is preferable that the heating treatment time is short.

In addition, the polyimide precursor composition of the present invention is applied on the substrate in a flexible manner and preferably dried at a temperature of 180 캜 or lower to form a film of the polyimide precursor composition on the substrate, and the film of the obtained polyimide precursor composition The polyimide precursor is imidized by heat treatment at a temperature at which the maximum heating temperature is higher than 350 DEG C, more preferably higher than 380 DEG C, particularly preferably higher than 400 DEG C, , Polyimide can be preferably produced.

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

The polyimide (the polyimide of the present invention) obtained from the polyimide precursor composition of the present invention is not particularly limited, but the coefficient of linear thermal expansion of the film to 150 deg. C to 250 deg. C is preferably 60 ppm / K or less , More preferably not more than 50 ppm / K, still more preferably not more than 45 ppm / K, still more preferably not more than 40 ppm / K, particularly preferably not more than 35 ppm / K. When the coefficient of linear thermal expansion is large, a difference in coefficient of linear thermal expansion from a conductor such as a metal is large, and there arises a problem that warpage increases when a circuit board is formed.

The polyimide (polyimide of the present invention) obtained from the polyimide precursor composition of the present invention is not particularly limited, but it is preferable that the total light transmittance (average light transmittance at a wavelength of 380 nm to 780 nm) , Preferably not less than 86%, more preferably not less than 87%, particularly preferably not less than 88%. When it is used for a display purpose or the like, if the total light transmittance is low, it is necessary to make the light source strong, which may cause energy consumption.

Particularly, when a polyimide film such as a display purpose is used for the purpose of transmitting light, the polyimide film preferably has high transparency. The polyimide (polyimide of the present invention) obtained from the polyimide precursor composition of the present invention is not particularly limited, but preferably has a light transmittance at a wavelength of 400 nm in a film having a thickness of 10 占 퐉, preferably at least 75% , Preferably 80% or more, more preferably 80% or more, still more preferably 81% or more, particularly preferably 82% or more.

The film made of the polyimide (polyimide of the present invention) obtained from the polyimide precursor composition of the present invention may differ depending on the application, but the thickness of the film is preferably 0.1 to 250 占 퐉, 1 mu m to 150 mu m, more preferably 1 mu m to 50 mu m, and particularly preferably 1 mu m to 30 mu m. When the polyimide film is used for the purpose of transmitting light, when the polyimide film is too thick, the light transmittance may be lowered.

The polyimide (the polyimide of the present invention) obtained from the polyimide precursor composition of the present invention is not particularly limited, but the 1% weight reduction temperature which is an index of the heat resistance of the polyimide film is preferably 395 DEG C or higher, May be 430 DEG C or higher, more preferably 440 DEG C or higher, and particularly preferably 470 DEG C or higher. When a gas barrier film or the like is formed on a polyimide by forming a transistor on the polyimide or the like, if the heat resistance is low, swelling occurs due to the outgass accompanying the decomposition of the polyimide between the polyimide and the barrier film There is a case.

The polyimide (the polyimide of the present invention) obtained from the polyimide precursor composition of the present invention is not particularly limited, but the retardation in the thickness direction of the polyimide film is preferably 1000 nm or less, more preferably 800 nm or less Preferably 700 nm or less, particularly preferably 600 nm or less. If the retardation in the thickness direction is large, the color of the transmitted light may not be displayed correctly, and the blurring of the color or the viewing angle may become narrow.

The polyimide obtained from the polyimide precursor composition of the present invention, that is, the polyimide of the present invention has a small retardation in the film thickness direction, excellent properties such as high transparency, bending resistance and high heat resistance, Can be suitably used in the applications of a transparent substrate for display, a transparent substrate for a touch panel, or a substrate for a solar cell because of its linear thermal expansion coefficient.

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, the present invention is not limited to the following method.

The polyimide precursor composition (varnish) of the present invention is softened and applied to a substrate such as a ceramic (glass, silicon, alumina, etc.), metal (copper, aluminum, stainless steel, etc.), heat resistant plastic film (polyimide film, , In a vacuum, in an inert gas such as nitrogen, or in air, using hot air or infrared rays, at a temperature of 20 to 180 ° C, preferably 20 to 150 ° C. Next, the obtained polyimide precursor film is peeled off from the base material, or the polyimide precursor film is peeled off from the base material, hot air or infrared rays are irradiated in an inert gas such as nitrogen, Imidization is carried out at a temperature of, for example, 200 to 500 ° C, preferably a maximum heating temperature of more than 350 ° C, more preferably more than 380 ° C, particularly preferably more than 400 ° C, Or a polyimide film can be produced. Further, in order to prevent oxidization deterioration of the obtained polyimide film, the heat imidization is preferably carried out in vacuum or in an inert gas. The thickness of the polyimide film (polyimide film layer in the case of the polyimide film / substrate laminate) herein is preferably 1 to 250 占 퐉, more preferably 1 to 150 占 퐉, Mu m.

The imidization reaction of the polyimide precursor can be carried out in the same manner as in the case of the polyimide precursor in the presence of a tertiary amine such as pyridine or triethylamine in the presence of a dehydrating cyclization reagent such as acetic anhydride Or by chemical treatment such as immersion in a solution containing a surfactant. In addition, these dehydrating and cyclization reagents may be added and stirred in advance in a polyimide precursor composition (varnish), and the mixture may be plied and dried on a substrate to partially imidize the polyimide precursor. , A polyimide film / base laminate or a polyimide film can be obtained.

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 polyimide film thus obtained.

The flexible conductive substrate can be obtained, for example, by the following method. That is, as a first method, a polyimide film / base layered product is formed on the surface of the polyimide film by sputtering, vapor deposition, printing, or the like without peeling the polyimide film from the base material and a conductive material (metal or metal oxide, , Conductive carbon, or the like) is formed to prepare a conductive laminate of a conductive layer / polyimide film / substrate. Thereafter, if necessary, the conductive layer / polyimide film laminate is peeled off from the substrate to obtain a transparent and flexible conductive substrate comprising the conductive layer / polyimide film laminate.

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

In addition, in the first and second methods, a gas barrier layer such as water vapor or oxygen, a light-shielding layer such as oxygen, or the like may be formed by sputtering, vapor deposition or gel-sol method before forming the conductive layer on the surface of the polyimide film, Or the like may be formed.

The conductive layer is preferably formed by a method such as a photolithography method, various printing methods, and an inkjet method.

The substrate of the present invention thus obtained has a circuit of a conductive layer on the surface of a polyimide film constituted by the polyimide of the present invention, optionally with a gas barrier layer or an inorganic layer interposed therebetween. This substrate is flexible, has excellent transparency, bending property, heat resistance, further has a very low coefficient of linear thermal expansion and excellent solvent resistance, so that it is easy to form a fine circuit. Therefore, this substrate can be preferably used as a substrate for a display, a touch panel, or a solar cell.

That is, a transistor (an inorganic transistor or an organic transistor) is further formed on the substrate by vapor deposition, various printing methods, ink jetting or the like to produce a flexible thin film transistor, and a liquid crystal element, And is preferably used as a photoelectric element.

Example

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

In each of the following examples, evaluation was carried out in the following manner.

≪ Evaluation of polyimide precursor solution (varnish) >

[Storage stability]

The varnish was stored at 23 占 폚. When the varnish was in a homogeneous state with fluidity after 3 days, it was evaluated as opaque after 3 days, or when the varnish was gelled.

≪ Evaluation of polyimide film &

[400 nm light transmittance, total light transmittance]

(Light transmittance at 380 nm to 780 nm) of the polyimide film having a thickness of about 10 mu m at 400 nm was measured using an ultraviolet visible spectrophotometer / V-650DS (manufactured by Nippon Shokubai Co., Ltd.) . The light transmittance at 400 nm and the total light transmittance were calculated using a Lambert-Beer equation with a reflectance of 10% and a total light transmittance at 400 nm measured. 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 탆 thick polyimide film with a reflectance of 10%

T ₁ ': light transmittance (%) at 400 nm measured

T _2: total light transmittance (%) of a polyimide film of 10 탆 thickness with a reflectance of 10%

T ₂ ': Total light transmittance (%) measured

L: film thickness of measured polyimide film (mu m)

[Modulus of elasticity, elongation at break]

A polyimide film having a film thickness of about 10 탆 was struck in a dumbbell shape conforming to IEC 450 standard and used as a test piece. Tensilon manufactured by ORIENTEC Co., Ltd. was used to measure the initial modulus of elasticity and elongation at break at a chuck length of 30 mm and a tensile rate of 2 mm / .

[Linear Thermal Expansion Coefficient (CTE)]

A polyimide film having a film thickness of about 10 탆 was cut out into a short strip of 4 mm in width and used as a test piece and a test piece of 15 mm in length between chucks and 2 g in weight was prepared using TMA / SS6100 (manufactured by SII Ai Nanotechnology Co., Ltd.) , And the temperature was raised to 500 ° C at a heating rate of 20 ° C / min. From the obtained TMA curve, the coefficient of linear thermal expansion from 150 deg. C to 250 deg. C was obtained.

[1% weight reduction temperature]

Using a polyimide film having a film thickness of about 10 占 퐉 as a test piece, the temperature was raised from 25 占 폚 to 600 占 폚 at a heating rate of 10 占 폚 / min in a nitrogen stream using a calorimeter apparatus (Q5000IR) manufactured by TA Instruments. From the weight curve obtained, a 1% weight reduction temperature was determined.

[Thickness phase difference (R _th ) of the film]

Using a polyimide film having a film thickness of 10 占 퐉 as a test piece and using an out-of-phase measurement article manufacturing phase difference measurement device (KOBRA-WR), the phase difference of the film was measured at an incident angle of 40 °. From the obtained retardation, the retardation in the thickness direction of the film having a film thickness of 10 mu m was determined.

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

[Diamine component]

tra-DACH: trans-1,4-diaminocyclohexane [purity: 99.1% (GC analysis)]

DABAN: 4,4'-diaminobenzanilide [Purity: 99.90% (GC analysis)]

PPD: p-phenylenediamine [purity: 99.9% (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)]

[Component of tetracarboxylic acid]

s-BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride [purity 99.9% (1 H-NMR analysis)]

a-BPDA: 2,3,3 ', 4'-biphenyltetracarboxylic acid dianhydride [purity 99.6% (1 H-NMR analysis)]

PMDA-HS: 1R, 2S, 4S, 5R-Cyclohexanetetracarboxylic acid dianhydride [Purity: 99.9% (GC analysis)]

CpODA-tee: trans-endo-endo-norbornane-2-spiro- [alpha] -cyclopentanone-a'- spiro-2 " -norbornane-5,5 ", 6,6 & Carboxylic acid dianhydride

CpODA-cee: cis-endo-endo-norbornane-2-spiro- [alpha] -cyclopentanone-a'- spiro-2 " -norbornane-5,5 ", 6,6 & Carboxylic acid dianhydride

CpODA: a mixture of CpODA-tee and CpODA-cee

PACDA: N, N '- (1,4-phenylene) bis (1,3-dioxoctahydroisobenzofuran-5-carboxamide)

[Table 1]

[menstruum]

NMP: N-methyl-2-pyrrolidone

Examples of the tetracarboxylic acid component used in Examples and Comparative Examples, the diamine components used in Examples and Comparative Examples in Table 1-2, the imidazole imide used in Examples and Comparative Examples in Table 1-3, Describe the structural formula of the zolinic compound.

[Table 1-1]

[Table 1-2]

[Table 1-3]

[Synthesis Example 1]

90.91 g (0.4 mol) of DABAN and 64.88 g (0.6 mol) of PPD were placed in a reaction vessel which was substituted with nitrogen gas and N-methyl-2-pyrrolidone was added to the total monomer 2835.90 g as a total amount of 16% by mass) was added to the mixture, followed by stirring at room temperature for 1 hour. 384.38 g (1.0 mole) of CpODA was gradually added to this solution. Followed by stirring at room temperature for 12 hours to obtain a homogeneous and viscous polyimide precursor solution (varnish A).

[Synthesis Example 2]

90.91 g (0.4 mole) of DABAN, 54.07 g (0.5 mole) of PPD and 36.84 g (0.1 mole) of BAPB were placed in a reaction vessel substituted with nitrogen gas, and N-methyl-2-pyrrolidone was added to the total monomer 2972.56 g which is a total amount 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. 384.38 g (1.0 mole) of CpODA was gradually added to this solution. Followed by stirring at room temperature for 12 hours to obtain a uniform and viscous polyimide precursor solution (varnish B).

[Synthesis Example 3]

22.73 g (0.100 mol) of DABAN was placed in a reaction vessel substituted with nitrogen gas, and N-methyl-2-pyrrolidone was added to the reactor so that the total mass of the injected monomers (the total of the diamine component and the carboxylic acid component) And the mixture was stirred at room temperature for 1 hour. 38.44 g (0.100 mol) of CpODA was slowly added to this solution. Followed by stirring at room temperature for 12 hours to obtain a homogeneous and viscous polyimide precursor solution (varnish C).

[Synthesis Example 4]

15.91 g (0.070 mol) of DABAN and 3.24 g (0.030 mol) of PPD were placed in a reaction vessel substituted with nitrogen gas, and N-methyl-2-pyrrolidone was added to the total monomer 302.35 g, which is a total amount of 16% by mass, was added, and the mixture was stirred at room temperature for 1 hour. 38.44 g (0.100 mol) of CpODA was slowly added to this solution. Followed by stirring at room temperature for 12 hours to obtain a homogeneous and viscous polyimide precursor solution (varnish D).

[Synthesis Example 5]

11.36 g (0.050 mol) of DABAN, 4.34 g (0.040 mol) of PPD and 2.00 g (0.010 mol) of 4,4'-ODA were placed in a reactor which was substituted with nitrogen gas and N-methyl- 294.74 g of the total amount of the injected monomers (the sum of the diamine component and the carboxylic acid component) was adjusted to 16 mass%, and the mixture was stirred at room temperature for 1 hour. 38.44 g (0.100 mol) of CpODA was slowly added to this solution. Followed by stirring at room temperature for 12 hours to obtain a homogeneous and viscous polyimide precursor solution (varnish E).

[Synthesis Example 6]

20.02 g (0.100 mol) of 4,4'-ODA was placed in a reaction vessel which was substituted with nitrogen gas, and N-methyl-2-pyrrolidone was added to the reactor under the conditions of the total mass of the injected monomers (total of diamine component and carboxylic acid component) 207.21 g, which was a content of 17% by mass, was added, and the mixture was stirred at room temperature for 1 hour. To this solution was slowly added 22.41 g (0.100 mmol) of PMDA-HS. Followed by stirring at room temperature for 12 hours to obtain a homogeneous and viscous polyimide precursor solution (varnish F).

[Synthesis Example 7]

22.73 g (0.100 mol) of DABAN was placed in a reaction vessel substituted with nitrogen gas, and N-methyl-2-pyrrolidone was added to the reaction vessel in such a manner that the total mass of the injected monomers (total sum of diamine component and carboxylic acid component) 296.29 g was added thereto, followed by stirring at room temperature for 1 hour. To this solution was slowly added 51.35 g (0.100 mol) of PACDA. Followed by stirring at room temperature for 12 hours to obtain a homogeneous and viscous polyimide precursor solution (varnish G).

[Synthesis Example 8]

10.81 g (0.100 mol) of tra-DACH was placed in a reaction vessel substituted with nitrogen gas and N-methyl-2-pyrrolidone was added in an amount of 12 mass% (total sum of diamine component and carboxylic acid component) , And the mixture was stirred at room temperature for 1 hour. 28.69 g (0.0975 mol) of s-BPDA and 0.74 g (0.0025 mol) of a-BPDA were gradually added to this solution. Followed by stirring at 50 DEG C for 12 hours to obtain a uniform and viscous polyimide precursor solution (varnish H).

[Example 1]

0.05 g (0.5 mmol) of 1,2-dimethylimidazole and 0.05 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole is 0.05 mol based on 1 mol of the repeating unit of the polyimide precursor.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 2]

0.15 g (1.6 mmol) of 1,2-dimethylimidazole and 0.15 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole is 0.16 moles per mole of the repeating unit of the polyimide precursor.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 3]

0.19 g (2.0 mmol) of 1,2-dimethylimidazole and 0.19 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole is 0.2 moles per mole of the repeating unit of the polyimide precursor.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 4]

0.96 g (10.0 mmol) of 1,2-dimethylimidazole and 0.38 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the amount of injection, the 1,2-dimethylimidazole is 1.0 mole relative to 1 mole of the repeat unit of the polyimide precursor.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 5]

1.92 g (20.0 mmol) of 1,2-dimethylimidazole and 0.38 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 2.0 moles.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 6]

0.04 g (0.5 mmol) of 1-methylimidazole and 0.04 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, the 1-methylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.05 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 7]

0.08 g (1.0 mmol) of 1-methylimidazole and 0.08 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, the 1-methylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.1 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 8]

0.16 g (2.0 mmol) of 1-methylimidazole and 0.16 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, 1-methylimidazole is 0.2 mole relative to 1 mole of the repeating unit of the polyimide precursor.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 9]

0.33 g (4.0 mmol) of 1-methylimidazole and 0.33 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, the 1-methylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.4 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 10]

0.16 g (2.0 mmol) of 2-methylimidazole and 0.16 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, the amount of 2-methylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.2 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 11]

0.14 g (2.0 mmol) of imidazole and 0.14 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, the imidazole is 0.2 mole relative to 1 mole of the repeating unit of the polyimide precursor.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 12]

0.29 g (2.0 mmol) of 2-phenylimidazole and 0.29 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, the amount of 2-phenylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.2 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 13]

0.24 g (2.0 mmol) of benzimidazole and 0.24 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, the benzimidazole is 0.2 moles per mole of the repeating unit of the polyimide precursor.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Comparative Example 1]

The varnish A obtained in Synthetic Example 1 filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidated by heating from room temperature to 410 ° C on a glass substrate under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) To obtain a colorless transparent polyimide film / glass laminate. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Comparative Example 2]

1.92 g (40.0 mmol) of 1,2-dimethylimidazole and 0.38 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the injection amount, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 4.0 moles. The resulting polyimide precursor solution was stored at 23 占 폚, and the polyimide precursor solution was gelled by the third day.

[Referential Example 1]

0.19 g (2.0 mmol) of 1,2-dimethylimidazole and 0.19 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.76 g of the varnish A obtained in Synthesis Example 1 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in the 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.2 moles.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidated by heating from room temperature to 350 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-1.

[Example 14]

0.05 g (0.5 mmol) of 1,2-dimethylimidazole and 0.05 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of 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 precursor solution . Calculated from the injection amount, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.05 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-2.

[Example 15]

0.10 g (1.0 mmol) of 1,2-dimethylimidazole and 0.10 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.1 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-2.

[Example 16]

0.19 g (2.0 mmol) of 1,2-dimethylimidazole and 0.19 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.2 moles.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-2.

[Example 17]

0.16 g (2.0 mmol) of 1-methylimidazole and 0.16 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of 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 precursor solution . Calculated from the injection amount, 1-methylimidazole is 0.2 mole relative to 1 mole of the repeating unit of the polyimide precursor.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-2.

[Comparative Example 3]

The varnish B obtained in Synthesis Example 2 filtered through a PTFE membrane filter was applied to a glass substrate and heated to a temperature of from room temperature to 410 deg. C on a glass substrate under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) To obtain a colorless transparent polyimide film / glass laminate. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-2.

[Comparative Example 4]

0.10 g (1.0 mmol) of 2-ethyl-2-imidazoline and 0.20 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of 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 precursor solution . Calculated from the injection amount, the amount of 2-ethyl-2-imidazoline relative to 1 mole of the repeating unit of the polyimide precursor is 0.1 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-2.

[Comparative Example 5]

0.20 g (2.0 mmol) of 2-ethyl-2-imidazoline and 0.40 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the varnish became gelled. Even if the solution was stirred at room temperature for 3 hours, a uniform polyimide precursor solution could not be obtained. Calculated from the amount of injection, the amount of 2-ethyl-2-imidazoline relative to 1 mole of the repeating unit of the polyimide precursor is 0.2 mole.

[Comparative Example 6]

0.49 g (5.0 mmol) of 2-ethyl-2-imidazoline and 0.98 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in varnish B) was added to the solution, and the varnish became gelled. Even if the solution was stirred at room temperature for 3 hours, a uniform polyimide precursor solution could not be obtained. Calculated from the amount of injection, the amount of 2-ethyl-2-imidazoline relative to 1 mole of the repeating unit of the polyimide precursor is 0.5 mole.

[Comparative Example 7]

0.25 g (3.0 mmol) of 2-methyl-2-imidazoline and 0.25 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of 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 precursor solution . Calculated from the amount of injection, the amount of 2-methyl-2-imidazoline relative to 1 mole of the repeating unit of the polyimide precursor is 0.3 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-2.

[Comparative Example 8]

0.44 g (3.0 mmol) of 2-phenylimidazoline and 0.44 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.39 g of varnish B obtained in Synthesis Example 2 (10 millimoles of 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 precursor solution . Calculated from the injection amount, the amount of 2-phenylimidazoline relative to 1 mole of the repeating unit of the polyimide precursor is 0.3 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-2.

[Example 18]

0.10 g (1.0 mmol) of 1,2-dimethylimidazole and 0.10 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 38.23 g of varnish C obtained in Synthesis Example 3 (10 millimoles of 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.1 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Comparative Example 9]

The varnish C obtained in Synthesis Example 3 filtered through a PTFE membrane filter was applied to a glass substrate and heated to a temperature of from room temperature to 410 deg. C on a glass substrate under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) To obtain a colorless transparent polyimide film / glass laminate. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Example 19]

0.10 g (1.0 mmol) of 1,2-dimethylimidazole and 0.10 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.99 g of varnish D obtained in Synthesis Example 4 (10 millimoles of 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 precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.1 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Comparative Example 10]

The varnish D obtained in Synthesis Example 4 filtered through a PTFE membrane filter was applied to a glass substrate, and the substrate was heated from room temperature to 410 占 폚 on a glass substrate under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) To obtain a colorless transparent polyimide film / glass laminate. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Example 20]

0.10 g (1.0 mmol) of 1,2-dimethylimidazole and 0.10 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 35.09 g of the varnish E obtained in Synthesis Example 5 (10 mmol of the repeating unit of the polyimide precursor in varnish E) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.1 mole.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Comparative Example 11]

The varnish E obtained in Synthetic Example 5 filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidized by heating from room temperature to 410 ° C on a glass substrate under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) To obtain a colorless transparent polyimide film / glass laminate. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Example 21]

0.19 g (2.0 mmol) of 1,2-dimethylimidazole and 0.19 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 24.97 g of the varnish F obtained in Synthesis Example 6 (10 mmol of the repeating unit of the polyimide precursor in the varnish F) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.2 moles.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidated by heating from room temperature to 400 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Comparative Example 12]

The varnish F obtained in Synthesis Example 6 filtered through a PTFE membrane filter was applied to a glass substrate and heated from room temperature to 400 deg. C on a glass substrate under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to thermally imidize To obtain a colorless transparent polyimide film / glass laminate. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Example 22]

0.19 g (2.0 mmol) of 1,2-dimethylimidazole and 0.19 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 37.04 g of varnish G obtained in Synthesis Example 7 (10 millimoles of the molecular weight of the repeating unit of the polyimide precursor in varnish G) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.2 moles.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidated by heating from room temperature to 350 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Comparative Example 13]

The varnish G obtained in Synthetic Example 7 filtered with a PTFE membrane filter was applied to a glass substrate and thermally imidated by heating from room temperature to 350 DEG C on a glass substrate in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) To obtain a colorless transparent polyimide film / glass laminate. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Example 23]

0.19 g (2.0 mmol) of 1,2-dimethylimidazole and 0.19 g of N-methyl-2-pyrrolidone were added to the reaction vessel to obtain a homogeneous solution. 33.53 g of the varnish H obtained in Synthesis Example 8 (10 millimoles of the repeating unit of the polyimide precursor in varnish H) was added to the solution, and the mixture was stirred at room temperature for 3 hours to obtain a uniform and viscous polyimide precursor solution . Calculated from the amount of injection, the amount of 1,2-dimethylimidazole relative to 1 mole of the repeating unit of the polyimide precursor is 0.2 moles.

The polyimide precursor solution filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidated by heating from room temperature to 370 占 폚 in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) on a glass substrate as it was, A polyimide film / glass laminate was obtained. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Comparative Example 14]

The varnish H obtained in Synthetic Example 8 filtered through a PTFE membrane filter was applied to a glass substrate and thermally imidated by heating from room temperature to 370 占 폚 in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) To obtain a colorless transparent polyimide film / glass laminate. Then, 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 mu m.

The properties of the polyimide film were measured and the results are shown in Table 2-3.

[Table 2-1]

[Table 2-2]

[Table 2-3]

From the results shown in Tables 2-1 to 2-3, it was confirmed that the imidazole compound (1,2-dimethylimidazole, 1-methylimidazole, 2-methylimidazole, (Examples 1 to 13 and Comparative Example 1, Examples 14 to 17 and Comparative Example 3, and Practical Example) were used as the polyimide precursor composition containing the polyimide precursor composition Example 18 and Comparative Example 9, Example 19 and Comparative Example 10, Example 20 and Comparative Example 11, Example 21 and Comparative Example 12, Example 22 and Comparative Example 13, Example 23 and Comparative Example 14). In addition, when 1,2-dimethylimidazole, 1-methylimidazole, 2-methylimidazole, or imidazole is used, the transmittance is also improved (compared with Examples 1 to 11 Comparison with Example 1, Examples 14 to 17 and Comparative Example 3, Example 18 and Comparative Example 9, Example 19 and Comparative Example 10, Example 20 and Comparative Example 11, Example 21 and Comparative Example 12, and Example 22 Example 13, Example 23 and Comparative Example 14). When the content of the imidazole-based compound is less than 4 moles relative to 1 mole of the repeating unit of the polyimide precursor, the storage stability is also excellent (Examples 1 to 13 and Comparative Example 2). With respect to the mechanical properties, it can be seen that the breaking point elongation is increased by setting the maximum heating temperature of the heat treatment for imidization to more than 350 ° C to 410 ° C (Example 3 and Reference Example 1).

As described above, the polyimide film obtained from the polyimide precursor composition of the present invention has excellent light transmittance, mechanical properties and low coefficient of linear thermal expansion in addition to a small retardation in the thickness direction, Can be preferably used as a transparent substrate capable of forming a colorless transparent and fine circuit.

Industrial availability

According to the present invention, there is provided a polyimide having excellent transparency, a polyimide having a smaller retardation in the thickness direction even in the same composition, or a polyimide precursor composition capable of obtaining a polyimide having a small retardation in thickness direction, (A solution composition containing a polyimide precursor), and a process for producing a polyimide. The polyimide obtained from the polyimide precursor composition has a high transparency, a small retardation in the thickness direction, and a low thermal expansion coefficient, thereby facilitating the formation of a fine circuit. Particularly, the polyimide obtained from the polyimide precursor composition can be used for a display, a touch panel, Can be preferably used.

Claims (12)

A polyimide precursor containing a repeating unit represented by the following formula (1) or a repeating unit represented by the following formula (2)
Containing compound,
Wherein the content of the imidazole-based compound is less than 4 moles per 1 mole of the repeating unit of the polyimide precursor.
[Chemical Formula 1]

(Wherein X < _{1 >} Is a quadrivalent group having an alicyclic structure, Y ₁ And R &_lt; ₂ > are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkyl silyl group having 3 to 9 carbon atoms.
(2)

(Wherein X ₂ is a tetravalent group having an aromatic ring, Y ₂ is a divalent group having an alicyclic structure, R ₃ and R ₄ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, 9 < / RTI > The method according to claim 1,
Wherein a polyimide obtained from the polyimide precursor composition has a light transmittance of at least 75% at a wavelength of 400 nm in a film having a thickness of 10 占 퐉. 3. The method according to claim 1 or 2,
Wherein the content of the imidazole compound is 0.05 mol or more and 2 mol or less based on 1 mol of the repeating unit of the polyimide precursor. 4. The method according to any one of claims 1 to 3,
Wherein the imidazole compound has a boiling point of less than 340 占 폚 at 1 atm. 5. The method according to any one of claims 1 to 4,
Wherein the imidazole compound is any one of 1,2-dimethylimidazole, 1-methylimidazole, 2-methylimidazole, 2-phenylimidazole, imidazole or benzimidazole Lt; / RTI > A process for producing a polyimide precursor composition according to any one of claims 1 to 5, wherein the polyimide precursor composition is subjected to a heat treatment at a maximum heating temperature of 350 DEG C to imidize the polyimide precursor. The method according to claim 6,
A process for producing a polyimide precursor composition, comprising the steps of: applying the polyimide precursor composition according to any one of claims 1 to 5 on a substrate;
A method for producing a polyimide, which comprises a step of heat-treating the polyimide precursor composition on a substrate at a maximum heating temperature of 350 DEG C to imidize the polyimide precursor. 8. The method according to claim 6 or 7,
Wherein the maximum heating temperature of the heat treatment is higher than 400 占 폚. 9. A polyimide produced by the method according to any one of claims 6 to 8. 10. The method of claim 9,
Wherein the polyimide has a light transmittance of at least 75% at a wavelength of 400 nm in a film having a thickness of 10 占 퐉. A polyimide film produced by the method according to any one of claims 6 to 8. A substrate for a display, a touch panel, or a solar cell, comprising the polyimide according to claim 9 or 10, or the polyimide film according to claim 11.