JP5606257B2 - Polyimide resin film and manufacturing method thereof - Google Patents

Description

The present invention relates to a polyimide resin film and a method for producing the same. Furthermore, the present invention relates to an electronic device material, a TFT substrate, a flexible display substrate, and a solar cell using the polyimide resin film.

In recent years, with rapid advances in displays such as liquid crystal, organic EL, and electronic paper, and electronics such as solar cells and touch panels, devices are required to be thinner and lighter, and more flexible. Therefore, instead of a glass substrate, a plastic film substrate that can be made thinner, lighter, and flexible has been studied.
In these devices, various electronic elements such as a thin film transistor and a transparent electrode are formed on a substrate. However, a high temperature process is required to form these electronic elements. However, since plastic films have low heat resistance and low dimensional stability at high temperatures, thermal deformation such as warpage is likely to occur in the manufacturing process, making alignment difficult and possibly destroying electrical elements. It was.

  These device fabrication processes can be divided into batch type and roll-to-roll. When using a roll-to-roll fabrication process, new equipment is required and several problems due to rotation and contact must be overcome. On the other hand, the batch type is a process in which a coating resin solution is applied on a glass substrate, dried, a substrate is formed, and then peeled off. For this reason, the glass substrate process and equipment such as the current TFT can be used, which is advantageous in terms of cost.

  Against this background, there is a strong demand for the development of a coating resin solution that can be applied to existing batch processes and that can provide a heat-resistant and highly dimensionally stable coating film.

  Since polyimide has high insulation performance as well as heat resistance, it has been applied to electronic components. For this reason, it is often laminated with a metal such as single crystal silicon or copper, and attempts have been made to reduce the linear thermal expansion coefficient of polyimide to the same level as single crystal silicon or metal.

  The chemical structure is a factor that greatly affects the linear thermal expansion coefficient of polyimide. In general, it is said that the linear thermal expansion coefficient decreases as the polyimide polymer chain becomes more rigid and linear, and in order to lower the linear thermal expansion coefficient, both the tetracarboxylic dianhydride and diamine, which are polyimide raw materials, are various. The structure has been proposed.

  Among these, a polyimide containing a fluorine substituent, for example, a polyimide obtained from 2,2′-bis (trifluoromethyl) benzidine (hereinafter referred to as TFMB), is organic in addition to heat resistance and linear thermal expansion coefficient. It is relatively excellent in solubility in a solvent and transparency, and there have been reported examples for liquid crystal alignment films and visual compensation films (for example, Patent Document 1 and Patent Document 2). Further, polyimide containing an amide group or an ester group is known as an interlayer insulating film material. (Patent Document 3)

JP 2004-252373 A JP 2004-46065 A JP 2010-106225 A

  For example, Patent Document 1 and Patent Document 2 describe the solubility, colorability, and birefringence of polyimide using TFMB. However, the use of laminated polarizing plates and liquid crystal alignment films is assumed, and details of other physical properties are not described.

  Further, Patent Document 3 describes a soluble polyimide containing an amide group or an ester group, but its thermal expansion coefficient is intended for matching with copper, so that the substrate exhibits extremely low thermal expansion characteristics such as glass. Further study was necessary to apply.

  As described above, polyimides containing fluorine atoms, particularly polyimides obtained from TFMB, have been known, but polyimides having a structure particularly suitable as a coating resin and having a low linear thermal expansion coefficient are known. It was not disclosed until.

  The present invention relates to a polyimide resin having a low linear thermal expansion coefficient and a method for producing the same, and to provide an electronic device material, a TFT substrate, and a flexible display substrate using a polyimide resin film having high heat resistance and high dimensional stability. It is. Moreover, when peeled from the substrate, it is possible to provide a film in which the warpage of the film is extremely small.

That is, the present invention relates to the following.
(I) A polyimide resin film comprising a polyimide resin containing a repeating unit represented by the following formula (1) and a polyimide resin solution containing an organic solvent, and then removing the organic solvent. A method for producing a polyimide resin film, wherein the step of removing the organic solvent is a step of drying the coating film at at least two stages of temperature.

(Ar represents a divalent organic group containing an aromatic ring and a fluorine atom, and B represents a divalent organic group)
(Ii) Ar represented by said Formula (1) is represented by following formula (2), The manufacturing method of the polyimide resin film as described in (i) characterized by the above-mentioned.

(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR ₂ groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom or an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is 0 to 4).
(Iii) The two-stage drying temperature is (i) 60 to 200 ° C. and (ii) 250 to 350 ° C. The method for producing a polyimide resin film according to (i) or (ii).
(Iv) The method for producing a polyimide resin film according to any one of (i) to (iii), wherein the linear expansion coefficient of the substrate at 100 to 300 ° C. is 35 ppm / K or less.
(V) The polyimide resin film according to any one of (i) to (iv), wherein the polyimide resin film has a linear expansion coefficient at 100 to 300 ° C. of 1 ppm / K or more and 30 ppm / K or less. A method for producing a film.
(Vi) A polyimide resin film obtained by the production method according to any one of (i) to (v).
(Vii) The warp of the glass substrate after film formation is 3.0 mm or less, The polyimide resin film as described in (vi).
(Viii) A TFT substrate containing the polyimide resin film described in (vi) or (vii).
(Ix) A flexible display substrate containing the polyimide resin film described in (vi) or (vii).
(X) A coating resin solution containing a polyimide resin containing a repeating unit represented by the following formula (1) and having a solid content concentration of 1% by weight or more.

(Ar represents a divalent organic group containing an aromatic ring and a fluorine atom, and B represents a divalent organic group)
(Xi) Ar represented by said Formula (1) is represented by following formula (2), The resin solution for coating as described in (x) characterized by the above-mentioned.

(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR ₂ groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom or an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is (It is an integer from 0 to 4)
(Xii) The coating according to (x) or (xi), wherein Ar represented in the formula (1) is selected from at least one of the following formula (3) or the following formula (4): Resin solution.

(Xiii) The resin solution for coating according to any one of (x) to (xii), wherein B represented by the formula (1) contains an aromatic ring and a fluorine atom.
(Xiv) The coating resin solution according to any one of (x) to (xiii), wherein B represented in the formula (1) is represented by the following formula (2).

(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR ₂ groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom or an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is (It is an integer from 0 to 4)
(Xv) B represented in the formula (1) is selected from at least one of the following formula (3) or the following formula (4), and any one of (x) to (xiv) The resin solution for coating as described in the item.

(Xvi) Any one of (x) to (xv), wherein the organic solvent is selected from at least one of an amide solvent, a ketone solvent, an ether solvent, a pyrrolidone solvent, and a glycol ether solvent. The resin solution for coating as described in the item.

According to the polyimide resin film of the present invention, a polyimide resin film excellent in high heat resistance and high dimensional stability can be obtained. Furthermore, a polyimide resin film with little warpage after peeling from the substrate can be obtained. Therefore, it can be suitably used for electronic device materials, TFT substrates, flexible display substrates, and solar cells. Moreover, since the polyimide resin film of this invention can utilize the existing process and equipment for glass substrates, it is advantageous in terms of cost.

The present invention provides a polyimide resin film comprising: a polyimide resin solution containing a repeating unit represented by the following formula (1) and a polyimide resin solution containing an organic solvent; It relates to a manufacturing method.

(Ar represents a divalent organic group containing an aromatic ring and a fluorine atom, and B represents a divalent organic group)
First, the polyimide resin containing the repeating unit represented by the formula (1) will be described.
Ar represented in the above formula (1) represents a divalent organic group containing an aromatic ring and a fluorine atom. Examples of the divalent substituent containing an aromatic ring and a fluorine atom include the following structures, but are not limited thereto.

In the above formula (2), D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. The two R bonded to the atom may be different from each other and may form a ring, and a hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), a CO group , SO ₂ group, SiR ₂ group (where R is as defined above), a functional group selected from an oxygen atom and a sulfur atom. E is a fluorine atom or an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is an integer of 0 to 4. In the above formula (2), the fluorine atom may be contained in D or E, but is preferably contained in E in order to obtain a rigid polymer structure. That is, m is preferably an integer of 1 to 4. E is preferably a fluorine atom or a trifluoromethyl group from the viewpoint of availability.

  From the viewpoints of the rigidity, low thermal expansion, solubility, and availability of raw materials exhibited by the resulting polymer among the structures listed in the above formula (2), particularly from the following formula (3) or (4) It is preferable that the structure is selected.

On the other hand, the polyimide resin containing the repeating unit represented by the above formula (1) is not particularly limited, but can be produced from an amide group-containing acid dianhydride and a diamine. The amide group-containing acid dianhydride can be easily produced by a known method such as the method described in JP 2010-106225 A. For example, it can be produced by amidation reaction of trimellitic anhydride chloride and diamine. As the amide group-containing acid dianhydride used when producing a polyimide resin containing the repeating unit represented by the formula (1), the following general formula (5)

The acid dianhydride represented by the formula is most preferred.
The diamine which is a raw material of the amide group-containing acid dianhydride and forms the Ar structure represented by the above formula (2) is not particularly limited, but 1,4-diamino-2-fluorohensen, 1,4- Diamino-2,3-difluorobenzene, 1,4-diamino-2,5-difluorobenzene, 1,4-diamino-2,6-difluorobenzene, 1,4-diamino-2,3,5-trifluorobenzene 1,4-diamino, 2,3,5,6-tetrafluorobenzene, 1,4-diamino-2- (trifluoromethyl) benzene, 1,4-diamino-2,3-bis (trifluoromethyl) Benzene, 1,4-diamino-2,5-bis (trifluoromethyl) benzene, 1,4-diamino-2,6-bis (trifluoromethyl) benzene, 1,4-diamino-2,3 -Tris (trifluoromethyl) benzene, 1,4-diamino, 2,3,5,6-tetrakis (trifluoromethyl) benzene, 2-fluorobenzidine, 3-fluorobenzidine, 2,3-difluorobenzidine, 2, 5-difluorobenzidine, 2,6-difluorobenzidine, 2,3,5-trifluorobenzidine, 2,3,6-trifluorobenzidine, 2,3,5,6-tetrafluorobenzidine, 2,2′-difluoro Benzidine, 3,3'-difluorobenzidine, 2,3'-difluorobenzidine, 2,2 ', 3-trifluorobenzidine, 2,3,3'-trifluorobenzidine, 2,2', 5-trifluorobenzidine 2,2 ′, 6-trifluorobenzidine, 2,3 ′, 5-trifluorobenzidine, 2,3 ′, 6, -trif Olobenzidine, 2,2 ′, 3,3′-tetrafluorobenzidine, 2,2 ′, 5,5′-tetrafluorobenzidine, 2,2 ′, 6,6′-tetrafluorobenzidine, 2,2 ′, 3,3 ′, 6,6′-hexafluorobenzidine, 2,2 ′, 3,3 ′, 5,5 ′, 6,6′-octafluorobenzidine, 2- (trifluoromethyl) benzidine, 3- ( Trifluoromethyl) benzidine, 2,3-bis (trifluoromethyl) benzidine, 2,5-bis (trifluoromethyl) benzidine, 2,6-bis (trifluoromethyl) benzidine, 2,3,5-tris ( Trifluoromethyl) benzidine, 2,3,6-tris (trifluoromethyl) benzidine, 2,3,5,6-tetrakis (trifluoromethyl) benzidine, 2,2′-bis (trifluorome ) Benzidine, 3,3′-bis (trifluoromethyl) benzidine, 2,3′-bis (trifluoromethyl) benzidine, 2,2 ′, 3-bis (trifluoromethyl) benzidine, 2,3,3 '-Tris (trifluoromethyl) benzidine, 2,2', 5-tris (trifluoromethyl) benzidine, 2,2 ', 6-tris (trifluoromethyl) benzidine, 2,3', 5-tris (tri Fluoromethyl) benzidine, 2,3 ′, 6, -tris (trifluoromethyl) benzidine, 2,2 ′, 3,3′-tetrakis (trifluoromethyl) benzidine, 2,2 ′, 5,5′-tetrakis (Trifluoromethyl) benzidine, 2,2 ′, 6,6′-tetrakis (trifluoromethyl) benzidine. These may be used alone or in combination of two or more. In particular, 2,2′-bis (trifluoromethyl) benzidine and 3,3′-bis (trifluoromethyl) benzidine that form an Ar structure represented by the above formulas (3) and (4) are further used. 2,2′-bis (trifluoromethyl) benzidine is particularly preferred.

  Next, B in the above formula (1) will be described. The diamine that forms the structure represented by B in the formula (1) is not particularly limited, and any diamine can be used. Specific examples of diamines that can be used include p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3 , 3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diamino Diphenylsulfone, 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane , 2,2-di (3 Aminophenyl) propane, 2,2-di (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 1,1-di (3-aminophenyl) -1 -Phenylethane, 1,1-di (4-aminophenyl) -1-phenylethane, 1- (3-aminophenyl) -1- (4-aminophenyl) -1-phenylethane, 1,3-bis ( 3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3- Bis (3-aminobenzoyl) benzene, 1,3-bis (4-aminobenzoyl) benzene, 1,4-bis (3-aminobenzoyl) benzene, 1,4-bis (4-aminobenzene) Zoyl) benzene, 1,3-bis (3-amino-α, α-dimethylbenzyl) benzene, 1,3-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (3- Amino-α, α-dimethylbenzyl) benzene, 1,4-bis (4-amino-α, α-dimethylbenzyl) benzene, 2,6-bis (3-aminophenoxy) benzonitrile, 2,6-bis ( 3-aminophenoxy) pyridine, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfur Bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- ( 4-aminophenoxy) phenyl] ether, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1 , 4-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) -α, α-dimethylbenzen L] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3-aminophenoxy) -α, α-dimethylbenzyl] Benzene, 1,4-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 4,4′-bis [4- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4′- Bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, 4,4 ′ -Bis [4- (4-aminophenoxy) phenoxy] diphenylsulfone, 3,3'-diamino-4,4'-diphenoxybenzophenone, 3,3'-diamino-4,4'-dibipheno Xylbenzophenone, 3,3′-diamino-4-phenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone, 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, 1,3-bis ( 3-aminopropyl) tetramethyldisiloxane, 1,3-bis (4-aminobutyl) tetramethyldisiloxane, α, ω-bis (3-aminopropyl) polydimethylsiloxane, α, ω-bis (3-amino Butyl) polydimethylsiloxane, bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, bis (2-aminomethoxy) Ethyl] ether, bis [2- (2-aminoethoxy) ethyl] ether, bis [2- (3-aminoprotoxy) ethyl] ether, 1,2-bis (aminomethoxy) ethane, 1,2-bis ( 2-aminoethoxy) ethane, 1,2-bis [2- (aminomethoxy) ethoxy] ethane, 1,2-bis [2- (2-aminoethoxy) ethoxy] ethane, ethylene glycol bis (3-aminopropyl) Ether, diethylene glycol bis (3-aminopropyl) ether, triethylene glycol bis (3-aminopropyl) ether, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6 -Diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-dia Nononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, trans-1,4- Diaminocyclohexane, 1,2-di (2-aminoethyl) cyclohexane, 1,3-di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4-aminocyclohexyl) ) Methane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 1,4-diamino-2-fluoro Hensen, 1,4-diamino-2,3-difluorobenzene, 1,4-diamino-2,5-difluorobenzene, 1 4-diamino-2,6-difluorobenzene, 1,4-diamino-2,3,5-trifluorobenzene, 1,4-diamino, 2,3,5,6-tetrafluorobenzene, 1,4- Diamino-2- (trifluoromethyl) hensen, 1,4-diamino-2,3-bis (trifluoromethyl) benzene, 1,4-diamino-2,5-bis (trifluoromethyl) benzene, 1, 4 -Diamino-2,6-bis (trifluoromethyl) benzene, 1,4-diamino-2,3,5-tris (trifluoromethyl) benzene, 1,4-diamino, 2,3,5,6-tetrakis (Trifluoromethyl) benzene, 2-fluorobenzidine, 3-fluorobenzidine, 2,3-difluorobenzidine, 2,5-difluorobenzidine, 2,6-difluorobenzene Dizine, 2,3,5-trifluorobenzidine, 2,3,6-trifluorobenzidine, 2,3,5,6-tetrafluorobenzidine, 2,2′-difluorobenzidine, 3,3′-difluorobenzidine, 2,3′-difluorobenzidine, 2,2 ′, 3-trifluorobenzidine, 2,3,3′-trifluorobenzidine, 2,2 ′, 5-trifluorobenzidine, 2,2 ′, 6-trifluoro Benzidine, 2,3 ′, 5-trifluorobenzidine, 2,3 ′, 6, -trifluorobenzidine, 2,2 ′, 3,3′-tetrafluorobenzidine, 2,2 ′, 5,5′-tetra Fluorobenzidine, 2,2 ′, 6,6′-tetrafluorobenzidine, 2,2 ′, 3,3 ′, 6,6′-hexafluorobenzidine, 2,2 ′, 3,3 ′, 5 5 ', 6,6'-octafluorobenzidine, 2- (trifluoromethyl) benzidine, 3- (trifluoromethyl) benzidine, 2,3-bis (trifluoromethyl) benzidine, 2,5-bis (trifluoro Methyl) benzidine, 2,6-bis (trifluoromethyl) benzidine, 2,3,5-tris (trifluoromethyl) benzidine, 2,3,6-tris (trifluoromethyl) benzidine, 2,3,5 6-tetrakis (trifluoromethyl) benzidine, 2,2′-bis (trifluoromethyl) benzidine, 3,3′-bis (trifluoromethyl) benzidine, 2,3′-bis (trifluoromethyl) benzidine, 2 , 2 ′, 3-bis (trifluoromethyl) benzidine, 2,3,3′-tris (trifluoromethyl) benzidine 2,2 ′, 5-tris (trifluoromethyl) benzidine, 2,2 ′, 6-tris (trifluoromethyl) benzidine, 2,3 ′, 5-tris (trifluoromethyl) benzidine, 2,3 ', 6, -tris (trifluoromethyl) benzidine, 2,2', 3,3'-tetrakis (trifluoromethyl) benzidine, 2,2 ', 5,5'-tetrakis (trifluoromethyl) benzidine, , 2 ′, 6,6′-tetrakis (trifluoromethyl) benzidine.

  B in the formula (1) preferably has a divalent organic group containing an aromatic ring and a fluorine atom, particularly in solubility in an organic solvent. More specifically, B is preferably the following formula (2).

In the above formula (2), D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. The two R bonded to the atom may be different from each other and may form a ring, and a hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), a CO group , SO ₂ group, SiR ₂ group (where R is as defined above), a functional group selected from an oxygen atom and a sulfur atom. E is a fluorine atom or an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is an integer of 0 to 4. In the above formula (2), the fluorine atom may be contained in D or E, but is preferably contained in E in order to obtain a rigid polymer structure. That is, m is preferably an integer of 1 to 4. E is preferably a fluorine atom or a trifluoromethyl group from the viewpoint of availability.

  As specific examples of the diamine that forms the structure represented by B in the above formula (1), the diamines shown as specific examples of the diamine that forms the Ar structure are used. These may be used alone or in combination of two or more. From the viewpoints of rigidity, low thermal expansion, solubility, and availability of raw materials exhibited by the resulting polymer, in particular, 2,2′-bis forming the B structure represented by the above formulas (3) and (4) It is more preferable to use (trifluoromethyl) benzidine and 3,3′-bis (trifluoromethyl) benzidine, and it is more preferable to use only 2,2′-bis (trifluoromethyl) benzidine.

  If the said polyimide resin contains the repeating unit represented by said Formula (1), it will not restrict | limit in particular about the other frame | skeleton in resin. For example, tetracarboxylic dianhydrides and diamines other than the skeleton represented by the above formula (1) can be used. The repeating unit of the polyimide resin of the present invention represented by the above formula (1) is selected according to the balance between solubility and low linear thermal expansion coefficient, but it is 30 mol% or more, preferably 50 mol% or more of the whole polyimide resin. More preferably, it is contained in an amount of 70 mol% or more. Moreover, the repeating unit of the said Formula (1) may be regularly arranged, and may exist in a polyimide resin at random.

  Other tetracarboxylic dianhydrides that can be used in combination with an amide group-containing acid dianhydride when producing a polyimide resin containing a repeating unit represented by the formula (1) include, for example, ethylene tetra Carboxylic dianhydride, butane tetracarboxylic dianhydride, cyclobutane tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2 , 2 ′, 3,3′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane Dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dica Boxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) ) Methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis (2,3- Dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis [(3,4-dicarboxy) benzoyl] benzene dianhydride, 1,4-bis [(3,4-Dicarboxy) benzoyl] benzene dianhydride, 2,2-bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} propane dianhydride, 2,2-bis { 4- [3- (1,2-Zika Boxy) phenoxy] phenyl} propane dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} ketone dianhydride, bis {4- [3- (1,2-dicarboxy) Phenoxy] phenyl} ketone dianhydride, 4,4′-bis [4- (1,2-dicarboxy) phenoxy] biphenyl dianhydride, 4,4′-bis [3- (1,2-dicarboxy) Phenoxy] biphenyl dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} ketone dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} Ketone dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} sulfone dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfone anhydrous Bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} sulfide dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfide dianhydride, 2 , 2-bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} -1,1,1,3,3,3-propane dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1 , 4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4 , 9,10-Perylenetetracarboxylic dianhydride 2,3,6,7-anthracene tetracarboxylic dianhydride, 1,2,7,8 although phenanthrene tetracarboxylic acid dianhydride, and the like, but is not limited thereto. These may be used alone or in combination of two or more.

  The weight average molecular weight of the polyimide resin of the present invention is not particularly limited, but is preferably 10,000 to 1,000,000, more preferably 50,000 to 500,000, More preferably, it is from 1,000,000 to 200,000. When the weight average molecular weight is 10,000 or less, it is difficult to obtain sufficient strength in the case of a film, and the linear expansion coefficient tends to increase, so that sufficient dimensional stability may not be obtained. . On the other hand, when it exceeds 1,000,000, the solution viscosity becomes too high and the handling tends to be difficult. In addition, the said weight average molecular weight means the value of polyethyleneglycol conversion by size exclusion chromatography (SEC).

Hereinafter, in order to describe the method for producing a polyimide resin according to the present invention, a method for synthesizing a polyamic acid and a method for dehydrating and ring-closing the polyamic acid to imidize will be described in detail.
A polyimide resin can be obtained from the polyamic acid which is the precursor. This polyamic acid can be obtained by reacting diamine and acid dianhydride in an organic solvent. Specifically, in an inert atmosphere such as argon or nitrogen, the diamine is dissolved in an organic solvent or dispersed in a slurry to obtain a diamine solution. On the other hand, the acid dianhydride may be added to the diamine solution after being dissolved or dispersed in an organic solvent or in a solid state.

  When synthesizing polyamic acid using the diamine and acid dianhydride, the reaction may be performed using at least one of each of the diamine and acid dianhydride. At this time, if 1 type of diamine and 1 type of acid dianhydride are substantially equimolar, it will become a polyamic acid of 1 type of acid dianhydride components and 1 type of diamine components. Further, when two or more kinds of acid dianhydride components and two or more kinds of diamine components are used, the molar ratio of the total amount of plural diamine components and the molar ratio of the total amount of plural acid dianhydride components are substantially equimolar. If adjusted, a polyamic acid copolymer can be optionally obtained.

  The temperature condition of the reaction between the diamine and the acid dianhydride (polyamide acid synthesis reaction) is not particularly limited, but is preferably 80 ° C. or less, more preferably 0 to 50 ° C. If it exceeds 80 ° C., the polyamic acid may be decomposed. Conversely, if it is 0 ° C. or less, the progress of the polymerization reaction may be slow. Moreover, what is necessary is just to set reaction time arbitrarily in the range of 10 minutes-30 hours.

  Furthermore, the organic solvent used for the synthesis reaction of the polyamic acid is not particularly limited as long as it is an organic polar solvent. However, as the reaction between the diamine and the acid dianhydride proceeds, polyamic acid is generated, and the viscosity of the reaction solution increases. Moreover, as will be described later, the polyamic acid solution obtained by synthesizing the polyamic acid can be heated under reduced pressure to simultaneously remove the organic solvent and imidize. Therefore, as the organic solvent, it is advantageous in terms of the process to select an organic solvent that can dissolve the polyamic acid and has a low boiling point as much as possible.

  Specifically, examples of the organic solvent used in the polyamic acid synthesis reaction include a formamide solvent such as N, N-dimethylformamide, an acetamide solvent such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and the like. Examples thereof include pyrrolidone solvents such as N-vinyl-2-pyrrolidone and ether solvents such as tetrahydrofuran, dioxane and dioxolane.

  The reaction solvent used for the polymerization of the polyamic acid is preferably a solvent capable of dissolving the acid dianhydride and diamine used, and more preferably a solvent capable of dissolving the produced polyamic acid. For example, urea solvents such as tetramethylurea, N, N-dimethylethylurea, dimethyl sulfoxide, diphenylsulfone, sulfoxide such as tetramethylsulfone, or sulfone solvents, N, N-dimethylacetamide (DMAc), N, Amide solvents such as N-dimethylformamide (DMF), N, N′-diethylacetamide, N-methyl-2-pyrrolidone (NMP), γ-butyllactone, hexamethylphosphoric triamide, chloroform, methylene chloride, etc. Alkyl halide solvents, aromatic hydrocarbon solvents such as benzene and toluene, phenol solvents such as phenol and cresol, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, dimethyl ether, diethyl ether, p-cresol Chirueteru can be mentioned ether solvents such as, typically may be used in combination as appropriate of two or more as needed using these solvents alone. In order to increase the solubility and reactivity of the polyamic acid, amide solvents such as DMF, DMAc, and NMP are preferably used.

  Next, a method for imidizing the polyamic acid to obtain a polyimide using the polyamic acid will be described. Imidization is performed by dehydrating and ring-closing the polyamic acid. This dehydration ring closure can be performed by an azeotropic method using an azeotropic solvent, a thermal method, or a chemical method.

  In the azeotropic method using an azeotropic solvent, a solvent that azeotropes with water such as toluene and xylene is added to the polyamic acid solution, and the temperature is raised to 170 to 200 ° C. to actively generate water generated by dehydration ring closure. The reaction may be carried out for about 1 to 5 hours while removing from the system. After completion of the reaction, it is precipitated in a poor solvent such as alcohol, washed with alcohol or the like as necessary, and then dried to obtain a polyimide resin.

  Dehydration ring closure by a thermal method may be performed by heating the polyamic acid solution. Alternatively, the polyamic acid solution may be cast or applied to a film-like support such as a glass plate, a metal plate, or PET (polyethylene terephthalate), and then heat treatment may be performed within a range of 80 ° C to 300 ° C. Furthermore, the polyamic acid solution can be directly dehydrated and ring-closed by placing the polyamic acid solution directly into a container that has been subjected to a release treatment such as coating with a fluororesin, and then drying by heating under reduced pressure. A polyimide resin can be obtained by dehydration ring closure of polyamic acid by such a thermal method.

  In addition, although the heating time of each said process changes with the process amount and heating temperature of the polyamic acid solution which performs dehydration ring closure, generally it is performed in the range of 1 minute-5 hours after the processing temperature reaches the maximum temperature. It is preferable.

  On the other hand, dehydration and ring closure by a chemical method is performed by adding a dehydrating agent and a catalytic amount of a tertiary amine as a catalyst to the polyamic acid solution as necessary, within a range of 20 to 150 ° C. for 1 hour. The reaction may be performed for about 10 hours.

As the dehydrating agent in the chemical method, acid anhydrides such as acetic anhydride and propionic anhydride are generally used. As the tertiary amine, pyridine, isoquinoline, triethylamine, trimethylamine, imidazole, picoline, or the like may be used.
After completion of the reaction, it is precipitated in a poor solvent such as alcohol, washed with alcohol or the like as necessary, and then dried to obtain a polyimide resin.

The present invention obtains a polyimide resin film exhibiting a low linear expansion coefficient by applying a polyimide resin solution containing a polyimide resin and an organic solvent obtained as described above onto a substrate and removing the organic solvent. be able to.
Next, the organic solvent contained in the polyimide resin solution will be described.

  The organic solvent is not particularly limited as long as it is a solvent that dissolves the polyimide resin. For example, amide solvents such as DMF (N, N-dimethylformamide), DMAc (N, N-dimethylacetamide), ketone solvents such as MEK (methyl ethyl ketone), MIBK (methyl isobutyl ketone), cyclohexanone, cyclopentanone, Ether solvents such as 1,3-dioxolane and 1,4-dioxane, pyrrolidone solvents such as NMP (N-methyl-2-pyrrolidone), glycol ether solvents such as methyl diglyme, ethyl diglyme and methyl triglyme In addition, ester solvents such as methyl acetate, ethyl acetate and isopropyl acetate, halogen solvents such as chloroform and dichloromethane, and aromatic hydrocarbon solvents such as toluene and xylene can be used. From the viewpoint of solubility, it is preferable that at least one organic solvent is selected from the group consisting of amide solvents, ketone solvents, ether solvents, pyrrolidone solvents, and glycol ether solvents. Ether solvents and amide solvents are particularly preferable, and amide solvents are more preferable. Moreover, if it is a range which melt | dissolves a polyimide resin, you may use the poor solvent which cannot melt | dissolve a polyimide resin timely as a mixed solvent.

  The boiling point of the organic solvent used for the polyimide resin solution is preferably 250 ° C. or lower, more preferably 220 ° C. or lower, and particularly preferably 200 ° C. or lower. Use of an organic solvent having a boiling point of more than 250 ° C. is not preferable because a drying process after coating requires a high temperature and a long time, which may cause decomposition of the polymer. Moreover, since many solvents remain | survive and there exists a possibility of having a bad influence on the quality of a polyimide film, it is unpreferable.

  Moreover, it is preferable to contain at least one organic solvent having a vapor pressure at 20 ° C. of 11000 Pa or less, more preferably 5000 Pa or less, and particularly preferably 2000 Pa or less. When only an organic solvent having a vapor pressure at 20 ° C. higher than 11000 Pa is used as a solvent, the solvent easily evaporates in the coating process, so that the viscosity change is large. Furthermore, when the coating is performed, the solution is dried at room temperature, which may cause die lip drying and the like, which may cause problems in continuous coating properties. That is, when a polyimide resin film is produced using a polyimide resin solution, particularly when subjected to a batch process of a glass substrate such as a TFT, an organic solvent having a vapor pressure at 20 ° C. of 11000 Pa or less is used. Since drying can be prevented, it is very suitable for batch processing.

  The polyimide resin solution of the present invention has a solid content concentration of 1% by weight or more. When the solid content concentration is less than 1% by weight, the film forming efficiency is lowered, and the viscosity of the polyimide resin solution is lowered, so that it is difficult to obtain a coating film having a uniform surface. Here, the solid content weight is a component other than the organic solvent, and even a liquid monomer or the like is included in the weight as a solid content.

In order to impart processing characteristics and various functionalities to the coating resin solution of the present invention, various other organic or inorganic low molecular weight or high molecular compounds may be blended. For example, antifoaming agents, leveling agents, surfactants, dyes, plasticizers, fine particles, sensitizers and the like can be used.
The polyimide resin solution of the present invention can be obtained by dissolving the polyimide resin obtained by the above method in the above organic solvent. The polyimide resin can be obtained by dissolving in an organic solvent, or the polyimide resin film can be redissolved.

Next, the manufacturing method of this invention is demonstrated. A polyimide resin film can be formed by applying and drying the polyimide resin solution of the present invention on a predetermined substrate. In this specification, the polyimide resin film obtained by this manufacturing method may be called a coating film. As the substrate to be applied, glass, SUS, silicon wafer, plastic film or the like is used, but is not limited thereto. In particular, when applied as a substrate material for electronic devices, the substrate to be applied is preferably glass or a silicon wafer, more preferably glass, from the viewpoint that existing equipment can be used. Further, the linear thermal expansion coefficient of the substrate to be applied is 30 ppm / K or less, more preferably 20 ppm / K or less, and particularly preferably 10 ppm / K or less, from the viewpoint of warping of the substrate after coating. .

  Next, the process of removing the organic solvent will be described. Regarding the film forming temperature, it is possible to select conditions suitable for the process, and there is no particular limitation. In order to develop low thermal expansion characteristics, it is preferable to form a film at 280 ° C. or higher. However, when polyimide is heated at a temperature of 250 ° C. or higher in a state where a large amount of solvent remains, molecular movement occurs while the polyimide remains plastic. It is not preferable. It is preferable to form the film at a temperature of two or more stages, that is, a stage of drying the solvent and a stage of promoting molecular orientation as the film forming temperature for expressing the low thermal expansion characteristics. If the first stage and the subsequent stages are two stages, the first stage is preferably in the range of 50 ° C to 250 ° C, more preferably 60 ° C to 200 ° C, and particularly preferably 80 ° C to 180 ° C. The second stage is preferably at a higher temperature than the first stage, specifically, 250 ° C to 350 ° C is preferable, 280 ° C to 320 ° C is preferable, and 290 ° C to 310 ° C is particularly preferable. The first stage is preferably carried out until the residual solvent is 15% or less. Although it is not particularly limited as long as it is 15% or less, it is preferable to carry out the second-stage drying at a higher temperature than the first stage after the first-stage drying. As a guide, the residual solvent is 2 to 15% in the first stage, and the residual solvent is 1% or less, preferably 0.5% or less in the second stage. Needless to say, as long as the drying step in the above two-step temperature range is included, each step may be further divided and heated to reach a temperature condition of three or more steps. Even in that case, it is necessary to perform drying so that the temperature of the next stage is higher than that of the immediately preceding stage.

  As mentioned above, when using the coating film of this invention as an electronic device material instead of glass, it is preferable to apply | coat and dry on a glass substrate, and to manufacture a coating film. The coating film may be peeled off from the glass and used as a coating film for a substrate, or may be peeled off from the glass after forming an electronic device in the form of a glass / coating film laminate. The coating film of the present invention is characterized by exhibiting a linear expansion coefficient close to that of glass and extremely small thermal deformation such as warpage.

  Regarding thermal deformation and dimensional stability of the coating film of the present invention, for example, warpage after peeling from the substrate, linear expansion coefficient, and thermal contraction rate can be used as indices.

  “Warpage of glass substrate after film formation” is obtained after forming a 30 μm-thick coating film on a 0.8 mm-thick glass plate as a substrate and performing heat treatment at 220 ° C. for 4 hours without peeling from the glass substrate. It refers to the warpage of the glass substrate and the polyimide resin film laminate. The warpage was evaluated by placing the glass substrate on which the polyimide resin film was formed on a flat table, measuring the portions where the four corners of the glass warped from the table, and measuring the maximum value.

  The warp after peeling from the substrate of the coating film of the present invention is preferably less than 1.0 mm, more preferably 0.5 mm or less, and most preferably 0.3 mm or less. When the warp after peeling from the substrate is 1.0 mm or more, handling may be difficult, alignment may be difficult at the time of forming the electric element, and the formed electric element may be destroyed.

  The linear expansion coefficient of the coating film of the present invention is preferably 35 ppm / K or less, more preferably 28 ppm / K or less, and 21 ppm / K or less in the range of 100 to 300 ° C. It is particularly preferred. When the linear expansion coefficient is large, thermal deformation such as warpage becomes large, and there is a possibility that alignment becomes difficult at the time of forming the electric element or the formed electric element is destroyed. The linear expansion coefficient can be measured by thermomechanical analysis (TMA).

  The thermal contraction rate of the coating film of the present invention represents a dimensional change when the film is peeled off from the glass substrate after film formation and then subjected to a heat treatment at 220 ° C. for 4 hours without applying a load. The thermal shrinkage is preferably −0.5% to 0.5%, more preferably −0.1% to 0.1%, and −0.05% to 0.05%. Most preferably. If it is out of this range, alignment may become difficult at the time of forming the electric element, or the formed electric element may be destroyed.

  The film thickness after drying of the coating film is preferably 1 μm or more and 50 μm or less, and more preferably 5 μm or more and 40 μm or less. When the film thickness is less than 1 μm, handling may be difficult, and when it is thicker than 50 μm, productivity may deteriorate or it may be difficult to obtain a uniform and flat coating film.

  The resin solution for coating according to the present invention and the coating film obtained therefrom have low thermal expansibility and high dimensional stability. Therefore, fields and products in which these characteristics are effective, such as electronic device materials and TFT substrates. It can be suitably used for a flexible display substrate, an image display device, or a solar cell. Furthermore, it can be used as an alternative material for the part where glass is used.

(Evaluation method)
The material characteristic values and the like described in the present specification are obtained by the following evaluation methods.
(1) Molecular weight of polyimide resin The weight average molecular weight (Mw) was calculated under the conditions shown in Table 1.

(2) Solubility test of polyimide resin in organic solvent For 0.1 g of resin, 9.9 g of organic solvent shown in Table 2 (solid content concentration 1%) was blended in a sample tube, and a magnetic stirrer was used. Stir at 0 ° C. for 2 hours. A completely dissolved sample was marked with ◯, a partially melted residue was marked with Δ, and an insoluble sample was marked with ×.

(3) Drying time of coating resin solution at normal temperature The coating resin solution is applied to a glass with a thickness of 300 μm and left at 23 ° C. and 65% RH. The tackiness of the coating film surface was evaluated by tactile sensation, and the time for tack free was evaluated. Those that did not become tack-free even after being left for 30 minutes were evaluated as “B”, those that became tack-free within 5 to 30 minutes were Δ, and those that became tack-free in less than 5 minutes were marked as “X”. In addition, this evaluation can be used as an index of the coating process stability of the coating resin solution. For example, when the evaluation is ○, it is used for a batch process of an actual glass substrate such as TFT. Shows a tendency not to dry.

(4) 10 mm square sample was cut out from the residual coating film of the coating film, dissolved in 1,4-dioxane at a concentration of 1 wt%, and the concentration of each solvent in this solution was measured by gas chromatography. As the gas chromatography apparatus, Hp6890 series GC System, HP6890 series AutoSampler (manufactured by HEWLETT PACKARD), HG-2500 (manufactured by GL Scuteaces), KAPSEL-CON Ye-3R (manufactured by Yaesaki Air Pressure Co., Ltd.), 3-32 are used. (Manufactured by J & W) was used. The sample injection volume was 2 μl, the inlet temperature was 225 ° C., and the pressure was 9.5 psi. The initial temperature of the oven was 35 ° C., held for 5 minutes, and then heated to 155 ° C. at a rate of temperature increase of 20 ° C./min. The carrier gas was He, the pressure was 9.5 psi, and the flow rate was 2.2 ml / min. The detector was FID, and the H ₂ flow rate was 40 ml / min and the AIR flow rate was 450 ml / min.

(5) Linear thermal expansion coefficient of the coating film The linear expansion coefficient at 100 to 200 ° C. and 100 to 300 ° C. is measured using a TMA120C manufactured by Seiko Electronics Co., Ltd., to a size of 3 mm in width and 10 mm in length. After cutting, the film thickness was measured, the temperature was raised to 10 to 320 ° C. at a load of 3 g at 10 ° C./min, cooled to 10 ° C., and further raised at 10 ° C./min to raise the second time. It calculated as an average value from the thermal expansion coefficient in 100-200 degreeC and 100-300 degreeC at the time of warm.

(6) Coating film and substrate laminate warpage As a substrate, a 30 μm thick coating film is formed on a 0.8 mm thick glass plate, and after heat treatment at 220 ° C. for 4 hours without peeling from the glass substrate, glass The substrate was placed on a flat table, and the height of the portion where the four corners of the glass substrate warped from the table was measured using a skimmer gauge, and the maximum value was evaluated as the warp.

(7) Coating film heat shrinkage ratio A coating film having a thickness of 30 μm was formed on a glass plate having a thickness of 0.8 mm as a substrate, marks were applied to the coating film at intervals of 10 cm, and the distance between the marks was measured. Then, heat treatment is carried out in an oven at 220 ° C. for 4 hours without peeling from the glass substrate, the distance between the marks after the heat treatment is measured, and the film longitudinal direction (MD direction or longitudinal direction) and the direction perpendicular to the longitudinal direction ( In the TD direction or the lateral direction), the thermal shrinkage rate was calculated by the following formula. In addition, each thermal contraction rate evaluated by n = 5, respectively, and used the average value.

  Heat shrinkage rate (%) = ((distance between the pre-heat treatment gauge points−distance between the heat treatment gauge points) / distance between the heat treatment gauge points) × 100

(Synthesis Example 1)
<Synthesis of amide group-containing acid dianhydride (following formula (5))>

  A 500 mL glass separable flask equipped with a stirrer equipped with a stainless steel stirring rod equipped with a four-blade stirring blade on a polytetrafluoroethylene sealing stopper and a nitrogen introducing tube, and trimellitic anhydride chloride 67 .4 g (0.32 mmol) was added, and a mixed solvent consisting of 190 g of ethyl acetate and 190 g of n-hexane was added and dissolved to prepare Solution A. Further, 25.6 g (0.08 mmol) of 2,2′-bis (trifluoromethyl) benzidine (hereinafter referred to as TFMB) was dissolved in another container by adding a mixed solvent composed of 72 g of ethyl acetate and 72 g of n-hexane, followed by removal. Solution B was prepared by adding 9.2 g of propylene oxide as an acid agent.

While cooling to about −20 ° C. in an ethanol ice bath, the solution B was added dropwise to the solution A with stirring, followed by stirring for 3 hours, and then stirring at room temperature for 12 hours. The precipitate was separated by filtration and washed well with an ethyl acetate / n-hexane mixed solvent (volume ratio 1: 1). Thereafter, the mixture was filtered and vacuum dried at 60 ° C. for 12 hours and further at 120 ° C. for 12 hours to obtain a white product with a yield of 70%. FT-IR: 3380 cm ⁻¹ (amide group NH stretching vibration), 3105 cm ⁻¹ (aromatic C—H stretching vibration), 1857 cm ⁻¹ , 1781 cm ⁻¹ (acid anhydride group C═O stretching vibration), 1677 cm ^{− 1} (amide group C═O stretching vibration) peak, and ¹ H-NMR, δ 11.06 ppm (s, NH, 2H), δ 8.65 ppm (s, on phthalimide, 3-position C _arom H, 2H), δ 8.37 ppm (on phthalimide, 5 and 6 position C _arom H, 4H), δ 7.46 ppm (d, on center biphenyl, 6 and 6 ′ position C _arom H, 2H), δ 8.13 ppm (d, on center biphenyl, 5 and 5 _'positions C arom H, 2H), δ8.27ppm (s, on the central biphenyl, 3 and 3' _C arom H, it was possible to confirm the peak of 2H) Et al., It was confirmed that the obtained amide group-containing tetracarboxylic dianhydride represented by the following formula as an objective compound (5). It was 274 degreeC when melting | fusing point of this compound was measured by DSC.

(Synthesis Example 2)
<Synthesis of amide group-containing polyimide resin>
A 3 L glass separable flask equipped with a stirrer equipped with a stainless steel stir bar and a nitrogen introduction tube was charged with 32.0 g (0.10 mol) of TFMB and dehydrated as a polymerization solvent (N, N-dimethylformamide ( In the following, 296 g of DMF) was charged and stirred, and then 66.8 g (0.10 mol) of an amide group-containing tetracarboxylic dianhydride having the structure of the formula (5) synthesized in Synthesis Example 1 was added to this solution. The mixture was stirred for 7 hours to obtain polyamic acid. In addition, the preparation density | concentration of the diamine compound and tetracarboxylic dianhydride in this reaction solution was 25 weight% with respect to all the reaction liquids.

  DMF was added to the above solution to adjust the solid content concentration to 20% by weight, and 15.8 g (0.20 mol) of pyridine was added as an imidization catalyst to completely disperse. To the dispersed solution, 24.5 g (0.24 mol) of acetic anhydride was added and stirred. After stirring at 100 ° C. for 4 hours, the solution was cooled to room temperature. DMF was added to the polyimide resin solution to a solid content concentration of 15% by weight, and 1200 g of isopropyl alcohol was added to the polyimide resin solution, followed by stirring for about 30 minutes. Thereafter, the polyimide slurry was taken out, and further 800 g of isopropyl alcohol was added to completely extract the solid content. The solid content extracted with 900 g of isopropanol was washed four times. And the obtained solid content was vacuum-dried at 150 degreeC with the vacuum dryer for 24 hours, and it took out as a polyimide resin. The evaluation results of the obtained polyimide resin are shown in Table 2.

Example 1
<Preparation of coating resin solution and coating film>
Using 1,3-dioxolane as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 2 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 10 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Example 2)
Using cyclopentanone as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 2 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Example 3)
Using DMAC as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 2 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Synthesis Example 3)
<Synthesis of amide group-containing polyimide resin>
A 3 L glass separable flask equipped with a stirrer equipped with a stainless steel stir bar and a nitrogen introduction tube was charged with 32.0 g (0.10 mol) of TFMB, and 296 g of dehydrated DMF as a polymerization solvent was stirred. To this solution, 66.1 g (0.099 mol) of the amide group-containing tetracarboxylic dianhydride synthesized in Synthesis Example 1 was added and stirred at room temperature for 12 hours to obtain a polyamic acid. In addition, the preparation density | concentration of the diamine compound and tetracarboxylic dianhydride in this reaction solution was 25 weight% with respect to all the reaction liquids.

  DMF was added to the above solution to adjust the solid concentration to 20% by weight, and 15.8 g (0.020 mmol) of pyridine was added as an imidization catalyst to completely disperse. To the dispersed solution, 24.5 g (0.024 mmol) of acetic anhydride was added and stirred. After stirring at 100 ° C. for 4 hours, the solution was cooled to room temperature. DMF was added to the polyimide resin solution to a solid content concentration of 15% by weight, and 1200 g of isopropyl alcohol was added to the polyimide resin solution, followed by stirring for about 30 minutes. Thereafter, the polyimide slurry was taken out, and further 800 g of isopropyl alcohol was added to completely extract the solid content. The solid content extracted with 900 g of isopropanol was washed four times. And the obtained solid content was vacuum-dried at 150 degreeC with the vacuum dryer for 24 hours, and it took out as a polyimide resin. The evaluation results of the obtained polyimide resin are shown in Table 2.

Example 4
<Preparation of coating resin solution and coating film>
Using 1,3-dioxolane as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 3 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 10 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Example 5)
Using cyclopentanone as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 3 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Example 6)
Using DMAC as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 3 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

( Reference Example 1 )
Using a 1,3-dioxolane / methyltriglyme mixed solvent (weight ratio = 7/3) as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 3 was prepared. The coating resin solution was applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 100 ° C. for 10 minutes and 300 ° C. for 2 hours to obtain a coating film. The evaluation results of the coating film are shown in Table 3.

(Example 8)
The coating resin solution prepared in Example 6 was applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 100 ° C. for 10 minutes and 300 ° C. for 2 hours to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Synthesis Example 4)
<Synthesis of amide group-containing polyimide resin>
A 3 L glass separable flask equipped with a stirrer equipped with a stainless steel stir bar and a nitrogen introduction tube was charged with 32.0 g (0.10 mol) of TFMB, and 296 g of dehydrated DMF as a polymerization solvent was stirred. To this solution, 66.1 g (0.099 mol) of the amide group-containing tetracarboxylic dianhydride synthesized in Example 1 was added and stirred at room temperature for 24 hours to obtain a polyamic acid. In addition, the preparation density | concentration of the diamine compound and tetracarboxylic dianhydride in this reaction solution was 25 weight% with respect to all the reaction liquids.

  DMF was added to the above solution to adjust the solid concentration to 20% by weight, and 15.8 g (0.020 mmol) of pyridine was added as an imidization catalyst to completely disperse. To the dispersed solution, 24.5 g (0.024 mmol) of acetic anhydride was added and stirred. After stirring at 100 ° C. for 4 hours, the solution was cooled to room temperature. DMF was added to the polyimide resin solution to a solid content concentration of 15% by weight, and 1200 g of isopropyl alcohol was added to the polyimide resin solution, followed by stirring for about 30 minutes. Thereafter, the polyimide slurry was taken out, and further 800 g of isopropyl alcohol was added to completely extract the solid content. The solid content extracted with 900 g of isopropanol was washed four times. And the obtained solid content was vacuum-dried at 150 degreeC with the vacuum dryer for 24 hours, and it took out as a polyimide resin. The evaluation results of the obtained polyimide resin are shown in Table 2.

Example 9
<Preparation of coating resin solution and coating film>
Using 1,3-dioxolane as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 4 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 10 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Example 10)
Using cyclopentanone as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 4 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Example 11)
Using DMAC as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 4 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Synthesis Example 5)
TFMB 9.7 g was placed in a 500 mL glass separable flask equipped with a stirrer equipped with a stainless steel stirring rod equipped with a four-blade stirring blade on a polytetrafluoroethylene sealing stopper and a nitrogen introduction tube, and polymerized. After adding 170 g of dehydrated DMF as a solvent for use and stirring, 20.2 g of the amide group-containing tetracarboxylic dianhydride synthesized in Example 1 was added to this solution and stirred at room temperature to obtain polyamide-amic acid. In addition, the preparation density | concentration of the diamine compound and tetracarboxylic dianhydride in this reaction solution was 15 weight% with respect to all the reaction liquids. DMF 100g was added to this solution, and it adjusted so that preparation concentration might be 10 weight%, and obtained polyamic acid.

(Example 12)
<Preparation of coating resin solution and coating film>
After coating the polyamic acid solution obtained in Synthesis Example 5 on a glass plate, it was dried at 60 ° C. for 10 minutes, further dried at 150 ° C. for 60 minutes and at 300 ° C. for 60 minutes. Thereafter, the film was peeled off from the glass plate to obtain a polyimide resin. Using this polyimide resin as a solvent, DMAC was used to prepare a coating resin solution containing 7% by weight of the polyimide resin. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Example 13)
After coating the polyamic acid solution obtained in Synthesis Example 5 on a glass plate, it was dried at 60 ° C. for 10 minutes, further dried at 150 ° C. for 60 minutes and at 300 ° C. for 60 minutes. Thereafter, the film was peeled off from the glass plate to obtain a polyimide resin. Using this polyimide resin as a solvent, DMF was used to prepare a coating resin solution containing 7% by weight of the polyimide resin. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Comparative Example 1)
<Preparation of coating film>
After coating the polyamic acid solution obtained in Synthesis Example 5 on a glass plate, it was dried at 60 ° C. for 10 minutes, further dried at 150 ° C. for 60 minutes and at 300 ° C. for 60 minutes. Thereafter, the film was peeled off from the glass plate to obtain a film. The obtained film did not exhibit low thermal expansion properties, and showed results that differed greatly from the film obtained from the polyimide resin solution. The evaluation results are shown in Table 2.

(Synthesis Example 6)
<Synthesis of polyimide resin>
As an acid dianhydride, 44.4 g (0.10 mol) of 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride (6FDA) Synthesis was performed in the same manner as in Synthesis Example 3 except that was used. The evaluation results of the obtained polyimide resin are shown in Table 3.

(Comparative Example 2)
<Preparation of coating resin solution and coating film>
Using 1,3-dioxolane as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 6 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

(Synthesis Example 7)
The same procedure as in Synthesis Example 3 except that 57.6 g (0.10 mol) of 2,2-bis (4-trimellitic acid monoester acid phenyl) propanoic acid dianhydride (ESDA) is used as the acid dianhydride. And synthesized. The evaluation results of the obtained polyimide resin are shown in Table 3.

(Comparative Example 3)
<Preparation of coating resin solution and coating film>
Using 1,3-dioxolane as a solvent, a coating resin solution containing 7% by weight of the polyimide resin synthesized in Synthesis Example 7 was prepared. This coating resin solution is applied as a polyimide resin solution film having a uniform film thickness on a glass plate with a bar coater and dried at 80 ° C. for 20 minutes, 150 ° C. for 1 hour, and further at 300 ° C. for 1 hour to obtain a coating film. It was. The evaluation results of the coating film are shown in Table 3.

Claims (14)

A polyimide resin film containing a repeating unit represented by the following formula (1) and a polyimide resin solution containing an organic solvent are applied on a substrate, and then the organic solvent is removed. a is, Ri step der step of removing the organic solvent to dry the coating film in at least two stages of temperature,
The two-stage drying temperature in the above process is (i) 60 ° C to 200 ° C and (ii) 250 ° C to 350 ° C,
A method for producing a polyimide resin film, wherein the residual solvent at the end of drying at the first stage at the drying temperature shown in (i) is 2 to 20% .
(Ar represents a divalent organic group containing an aromatic ring and a fluorine atom, and B represents a divalent organic group) Ar represented by said Formula (1) is represented by following formula (2), The manufacturing method of the polyimide resin film of Claim 1 characterized by the above-mentioned.
(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR ₂ groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom or an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is 0 to 4). 3. The method for producing a polyimide resin film according to claim 1, wherein a linear expansion coefficient of the substrate at 100 to 300 ° C. is 35 ppm / K or less. The method for producing a polyimide resin film according to any one of claims 1 to 3 , wherein the linear expansion coefficient of the polyimide resin film at 100 to 300 ° C is 1 ppm / K or more and 30 ppm / K or less. Polyimide resin film, characterized by being obtained by the process according to any one of claims 1-4. A TFT substrate comprising the polyimide resin film according to claim 5 . A flexible display substrate comprising the polyimide resin film according to claim 5 . A polyimide resin film comprising a polyimide resin containing a repeating unit represented by the following formula (1), wherein a linear expansion coefficient at 100 to 300 ° C. is 1 ppm / K or more and 30 ppm / K or less.
(Ar represents a divalent organic group containing an aromatic ring and a fluorine atom, and B represents a divalent organic group) The polyimide resin film according to claim 8 , wherein Ar represented by the formula (1) is represented by the following formula (2).
(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR ₂ groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom or an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is (It is an integer from 0 to 4) The polyimide resin film according to claim 8 or 9 , wherein Ar represented in the formula (1) is selected from at least one of the following formula (3) and the following formula (4).
Polyimide resin film according to any one of claims 8 to 10 B represented by the formula (1) in is characterized in that it comprises an aromatic ring and a fluorine atom. Polyimide resin film according to any one of claims 8 to 11, B represented by the formula (1) in is characterized by being represented by the following formula (2).
(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR ₂ groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom or an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is (It is an integer from 0 to 4) Polyimide according to any one of claims 8 to 12, characterized in that B represented by the formula (1) in is selected from at least one of the following formulas (3) or the following formula (4) Resin film .
The polyimide according to any one of claims 8 to 13 , wherein the organic solvent is selected from at least one of an amide solvent, a ketone solvent, an ether solvent, a pyrrolidone solvent, and a glycol ether solvent. Resin film .