KR20210088551A - Polyimide precursor, polyimide, polyimide resin film and flexible device - Google Patents

Abstract

(일반식 (1) 중, R¹ 및 R²는 각각 독립적으로, 탄소수 1 내지 20의 1가의 유기기를 나타낸다. m은 1 이상 200 이하의 정수를 나타낸다.)
(일반식 (2) 중, R³은 일반식 (3)으로 표시되는 2가의 유기기를 나타낸다. R⁴는 방향족 테트라카르복실산 잔기를 나타낸다. X¹ 및 X²는 각각 독립적으로, 수소 원자, 탄소수 1 내지 10의 1가의 유기기 또는 탄소수 1 내지 10의 1가의 알킬실릴기를 나타낸다.)A polyimide precursor contains the structure represented by General formula (1), and the structural unit represented by General formula (2).

(In general formula (1), R ¹ and R ² each independently represent a monovalent organic group having 1 to 20 carbon atoms. m represents an integer of 1 or more and 200 or less.)
(In the general formula (2), R ³ represents a divalent organic group represented by the general formula (3). R ⁴ represents an aromatic tetracarboxylic acid residue. X ¹ and X ² are each independently a hydrogen atom; It represents a monovalent organic group having 1 to 10 carbon atoms or a monovalent alkylsilyl group having 1 to 10 carbon atoms.)

Description

Polyimide precursor, polyimide, polyimide resin film and flexible device

The present invention relates to a polyimide precursor, a polyimide, a polyimide resin film, and a flexible device.

Compared with glass, an organic film has many flexibility, it is hard to crack, and has features, such as light weight. In recent years, the movement which makes a flat panel display flexible is active by replacing the board|substrate of a flat panel display with an organic film.

Examples of the resin used for the organic film include polyester, polyamide, polyimide, polycarbonate, polyethersulfone, acryl, epoxy, and cycloolefin polymer. Among them, polyimide is suitable as a display substrate because it is a highly heat-resistant resin. However, the general polyimide resin is colored brown or yellow due to its high aromatic ring density, and the transmittance in the visible ray region is low, and it has been difficult to use it in a field requiring transparency.

Regarding the subject of improving the transparency of such polyimide resin, Patent Document 1 discloses an amine having an alicyclic acid dianhydride and a hydroxyl group, specifically 2,2-bis[3-(3-aminobenzamide)-4 A polyimide resin film using -hydroxyphenyl]hexafluoropropane (HFHA) is disclosed as having high heat resistance and light transmittance.

Moreover, the method of obtaining a flexible touch panel is indicated by patent document 2 using the transparent polyimide resin film obtained by baking in air.

International Publication No. 2013/24849 International Publication No. 2018/84067

Patent Document 1 discloses a polyimide having high transparency and low in-plane/out-of-plane birefringence. However, in the polyimide described in Patent Document 1, since it is necessary to bake the polyimide resin film in an inert oven for a long time in order to form a film, there is a problem that the film formation of the polyimide resin film takes great cost and time. .

Moreover, patent document 2 has the indication to the effect that a transparent polyimide resin film is obtained by baking in air for 30 minutes. However, the transparent polyimide resin film described in Patent Document 2 is a resin film having a glass transition temperature of about 220°C to 230°C, and as a resin film used for devices such as touch panels and displays, there is a problem that the glass transition temperature is low. . When a polyimide resin film having a low glass transition temperature is used in a device, for example, in order to improve the reliability of the touch panel, if an inorganic film is formed on the polyimide resin film and then a touch panel or a color filter is formed, the inorganic film Wrinkles are generated and the surface smoothness is lowered.

As described above, in the present situation, a method for efficiently obtaining a polyimide having high transparency, high glass transition temperature, low in-plane/out-of-plane birefringence, and good substrate adhesion is not known.

The present invention has been made in view of the above problems, and provides a polyimide precursor that can efficiently obtain a polyimide having high transparency, high glass transition temperature, low in-plane/out-of-plane birefringence, and good adhesion to a support substrate. for the first purpose. Moreover, this invention makes it a 2nd objective to provide the polyimide obtained using such a polyimide precursor, a polyimide resin film, and a flexible device.

In order to solve the above-mentioned subject and achieve the objective, the polyimide precursor which concerns on this invention contains the structure represented by General formula (1), and the structural unit represented by General formula (2), It is characterized by the above-mentioned.

(In general formula (1), R ¹ and R ² each independently represent a monovalent organic group having 1 to 20 carbon atoms. m represents an integer of 1 or more and 200 or less.)

(In the general formula (2), R ³ represents a divalent organic group represented by the general formula (3). R ⁴ represents an aromatic tetracarboxylic acid residue. X ¹ and X ² are each independently a hydrogen atom; It represents a monovalent organic group having 1 to 10 carbon atoms or a monovalent alkylsilyl group having 1 to 10 carbon atoms.)

Moreover, when the polyimide precursor which concerns on this invention makes the quantity of the said whole polyimide precursor 100 mass % in said invention, 0.1 mass % or more and 30 mass % of the structure represented by the said General formula (1) It is characterized in that it includes the following.

Further, in the above invention, the polyimide precursor according to the present invention contains 30 mol% or more of the structural unit of the divalent organic group represented by the general formula (3) among all the diamine residues contained in the polyimide precursor. characterized in that

In addition, the polyimide precursor according to the present invention, in the above invention, comprises 5 mol% or more and 55 mol% or less of acid anhydride residues having a fluorene skeleton among all the acid dianhydride residues contained in the polyimide precursor. do it with

Moreover, in said invention, the polyimide precursor which concerns on this invention contains the residue of the compound represented by following General formula (4), It is characterized by the above-mentioned.

(In the general formula (4), a plurality of R ⁵ are each independently a single bond or a divalent organic group having 1 to 10 carbon atoms. A plurality of R ⁶ and R ⁷ are each independently a monovalent group having 1 to 3 carbon atoms. It is an aliphatic hydrocarbon group or an aromatic group having 6 to 10 carbon atoms. L is an amino group or a reactive derivative thereof, or a group containing an acid dianhydride structure or a reactive derivative thereof. y is an integer of 1 or more and 199 or less.)

Further, in the above invention, the polyimide precursor according to the present invention is a residue of a compound represented by the general formula (4) and y is 1 or more and 20 or less, and a residue of the compound represented by the general formula (4), and y is It is characterized by including both residues of a compound of 21 or more and 60 or less.

Moreover, in said invention, the polyimide precursor which concerns on this invention contains the residue of the diamine represented by following General formula (9), It is characterized by the above-mentioned.

(In the general formula (9), R ⁸ is a substituted or unsubstituted phenyl group. s represents an integer of 1 or more and 4 or less.)

Moreover, the polyimide which concerns on this invention is formed by imidating the polyimide precursor in any one of said inventions, It is characterized by the above-mentioned.

Moreover, the polyimide which concerns on this invention contains the structure represented by General formula (1), and the structural unit represented by General formula (14), It is characterized by the above-mentioned.

(In general formula (1), R ¹ and R ² each independently represent a monovalent organic group having 1 to 20 carbon atoms. m represents an integer of 1 or more and 200 or less.)

(In the general formula (14), R ³ represents a divalent organic group represented by the general formula (3). R ⁴ represents an aromatic tetracarboxylic acid residue.)

Moreover, the polyimide which concerns on this invention contains 0.1 mass % or more and 30 mass % or less of the structure represented by the said General formula (1) when the quantity of the said whole polyimide is 100 mass % in said invention. characterized in that

In addition, the polyimide according to the present invention is characterized in that, in the present invention, 30 mol% or more of the structural unit of the divalent organic group represented by the general formula (3) is contained among all the diamine residues contained in the polyimide. do.

Moreover, the polyimide resin film which concerns on this invention contains the polyimide in any one of said inventions, It is characterized by the above-mentioned.

Moreover, in said invention, the polyimide resin film which concerns on this invention is 1.20 g/cm<3> or more and 1.43 g/cm<3> or less, It is characterized by the above-mentioned.

Further, in the above invention, the polyimide resin film according to the present invention has an in-plane/out-of-plane birefringence of 0.01 or less.

Moreover, in said invention, the polyimide resin film which concerns on this invention is yellowness 3 or less, It is characterized by the above-mentioned.

Moreover, the flexible device which concerns on this invention is provided with the polyimide resin film in any one of said inventions, It is characterized by the above-mentioned.

According to the present invention, a polyimide precursor capable of efficiently obtaining a polyimide having high transparency, high glass transition temperature, low in-plane/out-of-plane birefringence, and good adhesion to a support substrate by heating in air for a short time can be provided. have. The polyimide and polyimide resin film obtained from the polyimide precursor of this invention can be used conveniently as a flexible substrate for displays, such as a flexible device, for example, a touch panel and a color filter. By using such a flexible board|substrate, manufacture of a highly reliable flexible display (an example of a flexible device) is possible with a fixed stand.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows one structural example of the color filter containing the polyimide resin film which concerns on embodiment of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail with drawings. In addition, this invention is not limited by the following embodiment. In addition, each drawing referenced in the following description is only schematically showing the shape, size, and positional relationship to the extent that the content of this invention can be understood. That is, the present invention is not limited only to the shape, size, and positional relationship illustrated in each drawing.

<Polyimide precursor>

The polyimide precursor which concerns on embodiment of this invention contains the structure represented by General formula (1), and the structural unit represented by General formula (2).

In general formula (1), R<^1> and R<^2> respectively independently represent a C1-C20 monovalent organic group. m represents an integer of 1 or more and 200 or less.

In general formula (2), R ³ represents a divalent organic group represented by general formula (3). R ⁴ represents an aromatic tetracarboxylic acid residue. X ¹ and X ² each independently represent a hydrogen atom, a monovalent organic group having 1 to 10 carbon atoms, or a monovalent alkylsilyl group having 1 to 10 carbon atoms.

In addition, "C1-C10" represents "C1 or more and C10 or less." The same description in the present invention has the same meaning.

The polyimide precursor which concerns on embodiment of this invention exhibits the following effects by including the structure represented by General formula (1), and the structural unit represented by General formula (2). That is, by heating this polyimide precursor in air for a short time, a polyimide having high transparency, high glass transition temperature (Tg), low in-plane/out-of-plane birefringence, and good substrate adhesion can be efficiently obtained.

The structural unit represented by the general formula (2) is a structural unit of a compound that is repeated in the polyimide precursor according to the embodiment of the present invention. Hereinafter, this structural unit is appropriately called a "repeating structural unit" or simply a "repeating unit." This is not limited to the structural unit represented by General formula (2), The same applies also to the structural unit represented by general formula other than General formula (2).

The polyimide precursor according to the embodiment of the present invention has a structure represented by the general formula (1) in at least one of the acid dianhydride residue and the diamine residue constituting the polyimide. Thereby, the adhesive force of the polyimide obtained from a polyimide precursor, and a glass support substrate improves. It is thought that this originates in the structure represented by General formula (1), and strong interaction arises when the silanol group which exists on the glass surface forms a hydrogen bond.

A hydrocarbon group, an alkoxy group, an epoxy group, etc. are mentioned as a C1-C20 monovalent organic group in R<^1> and R<^2>. As a hydrocarbon group in R<^1> and R<^2> , a C1-C20 alkyl group, a C3-C20 cycloalkyl group, a C6-C20 aryl group, etc. are mentioned.

The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group and the like. As a C3-C20 cycloalkyl group, it is preferable that it is a C3-C10 cycloalkyl group, and a cyclopentyl group, a cyclohexyl group, etc. are mentioned specifically,. As the C6-C20 aryl group, it is preferable that it is a C6-C12 aryl group, and a phenyl group, a tolyl group, a naphthyl group, etc. are mentioned specifically,.

As an alkoxy group in R<^1> and R<^2> , a methoxy group, an ethoxy group, a propoxy group, isopropyloxy group, a butoxy group, a phenoxy group, a propenyloxy group, a cyclohexyloxy group, etc. are mentioned.

^{It is preferable that R<1>} and R<^2> in General formula (1) are a C1-C3 monovalent|monohydric aliphatic hydrocarbon group or a C6-C10 aromatic group. It is because the storage stability of a polyimide precursor composition is favorable and the polyimide obtained has high heat resistance. Here, the monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms is preferably a methyl group. The aromatic group having 6 to 10 carbon atoms is preferably a phenyl group.

It is preferable that at least 1 ^{of R<1>} and R<^2> in General formula (1) contains an aromatic group. This is because phase separation resulting from having a structure represented by the general formula (1) is suppressed, and a polyimide with high transparency can be obtained. ^{In this case, among all R 1} and R ² in the structure represented by the general formula (1), the ratio of the number of moles M1 of the aliphatic hydrocarbon group having 1 to 3 carbon atoms to the number of moles M2 of the aromatic group having 6 to 10 carbon atoms (provided that M1+ M2=100) is preferably M1:M2=90 to 10:10 to 90, more preferably M1:M2=85 to 15:15 to 85, still more preferably M1:M2=85 to 30 :15 to 70. When this ratio exists in the said range, haze generation|occurrence|production of the polyimide by phase separation can be suppressed, and the polyimide resin film with high transparency can be obtained.

It is preferable that the polyimide precursor according to the embodiment of the present invention contains 0.1% by mass or more and 30% by mass or less of the structure represented by the general formula (1) when the total amount of the polyimide precursor is 100% by mass. . Moreover, in the said polyimide precursor, it is preferable that 5 mass % or more and 25 mass % or less are contained, and, as for the structure represented by General formula (1), it is more preferable that it contains 8 mass % or more and 23 mass % or less, 10 It is more preferable that it is contained in mass % or more and 22 mass % or less.

If the ratio of the structure represented by the general formula (1) contained in the polyimide precursor is within the above range, cloudiness of the polyimide obtained, a decrease in the glass transition temperature, and an increase in the amount of gas generated during heating can be suppressed.

In the general formula (1), m is an integer of 1 or more and 200 or less, preferably an integer of 2 or more and 150 or less, more preferably an integer of 5 or more and 100 or less, and still more preferably an integer of 10 or more and 60 or less. . When this constant m is in the said range, the adhesiveness of a polyimide and a glass substrate can be improved. Moreover, it can suppress that a polyimide resin film becomes cloudy or the mechanical strength of a polyimide resin film falls, and can reduce the residual stress of a polyimide resin film further.

In the present invention, the "residual stress" refers to the stress remaining inside the film after forming the film by coating the resin composition on a substrate such as a glass substrate, and is a target of "warpage" that may occur in the film. Specifically, it can be measured by the method described in the following Examples.

It is preferable that the polyimide precursor which concerns on embodiment of this invention contains the structure represented by General formula (1) as mentioned above, and contains the residue of the compound represented by following General formula (4). Such a polyimide precursor is obtained by using the compound represented by General formula (4) as one of the monomer components.

In general formula (4), some R<^5> is each independently a single bond or a C1-C10 divalent organic group. A plurality of R ⁶ and R ⁷ are each independently a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms. L is an amino group or a group containing a reactive derivative thereof or an acid dianhydride structure or a reactive derivative thereof. y is an integer of 1 or more and 199 or less. It is preferable that it is 1 or more and 100 or less, and, as for this integer y, it is more preferable that it is 1 or more and 60 or less.

In the general formula (4), as the ^{divalent organic group having 1 to 10 carbon atoms in R 5} , an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, etc. can be heard Examples of the alkylene group having 1 to 10 carbon atoms include a methylene group, a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group. Examples of the cycloalkylene group having 3 to 10 carbon atoms include a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, and a cycloheptylene group. As the C6-C10 arylene group, a C6-C10 aromatic group is preferable, and a phenylene group, a naphthylene group, etc. are mentioned. As a C1-C10 divalent organic group in R<^5> , a C1-C10 divalent aliphatic hydrocarbon group is especially preferable.

As a preferable specific example of each group in R<^6> and R<^7> , "a C1-C3 monovalent aliphatic hydrocarbon group" or "C6-C6" ^{in R<1>} and R<^2> in the structure represented by the said General formula (1) The same thing as the aromatic group of 10" is mentioned.

As a reactive derivative of the amino group in L in General formula (4), an isocyanate group, a bis(trialkylsilyl)amino group, etc. are mentioned. When L is an amino group, as a specific example of the residue of the compound represented by the general formula (4), X22-1660B-3 (manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight 4,400, y=39), which is amino-modified methylphenyl silicone at both terminals. to 41, phenyl group: methyl group = 25:75 mol%), X22-9409 (manufactured by Shin-Etsu Chemical, number average molecular weight 1,340, y = 10 to 11, phenyl group: methyl group = 25:75 mol%), X22-9681 (Shin-Etsu Chemical Co., Ltd.) S-Chemical company, number average molecular weight 2,840, y=25 to 26, phenyl group:methyl group=25:75 mol%), both terminal amino-modified dimethyl silicone, X22-161A (Shin-Etsu Chemical, number average molecular weight 1,600) , y = 19 to 20), X22-161B (manufactured by Shin-Etsu Chemical, number average molecular weight of 3,000, y = 38 to 39), KF8012 (manufactured by Shin-Etsu Chemical, number average molecular weight of 4,400, y = 57), BY16-835U (manufactured by Toray Dow Corning, number average molecular weight 900, y = 9 to 10), Silaplane FM3311 (manufactured by Chisso Corporation, number average molecular weight 1000, y = 11 to 12), 1,3-bis(3-amino) propyl) tetramethyldisiloxane (number average molecular weight 248.5, y=1), etc. are mentioned. Hereinafter, "1,3-bis(3-aminopropyl) tetramethyldisiloxane" is called "SiDA".

Moreover, as a reactive derivative of the acid anhydride structure in L in General formula (4), the acid ester of dicarboxylic acid, the acid chloride of dicarboxylic acid, etc. are mentioned. Specific examples of the group in which L includes an acid anhydride structure include groups represented by the following formulas.

Specific examples of the compound represented by the general formula (4) in the case where L is a group containing an acid anhydride structure include X22-168AS (manufactured by Shin-Etsu Chemical, number average molecular weight 1,000), X22-168A (Shin-Etsu Chemical) Corporation, number average molecular weight 2,000), X22-168B (Shin-Etsu Chemical Corporation, number average molecular weight 3,200), X22-168-P5-B (Shin-Etsu Chemical Corporation, number average molecular weight 4,200, y=34 to 38, phenyl group:methyl group = 25:75 mol%), DMS-Z21 (The Gelest company make, number average molecular weight 600-800, y=3-6) etc. are mentioned.

From the viewpoint of improving the molecular weight of the polyimide precursor, the viewpoint of avoiding cloudiness of the varnish containing the polyimide precursor and the solvent, the viewpoint of cost, and the heat resistance of the polyimide obtained, L in the general formula (4) is more preferably an amino group desirable.

The polyimide precursor according to the embodiment of the present invention is a residue of a compound represented by the general formula (4) and y is 1 or more and 20 or less (hereinafter, “residue of the first compound represented by general formula (4)”) It is preferable to include both a residue of a compound represented by the general formula (4) and wherein y is 21 or more and 60 or less (hereinafter referred to as "residue of a second compound represented by general formula (4)"). Do. When the said polyimide precursor contains the residue of the 1st compound represented by General formula (4), adhesiveness with a support substrate is favorable, and it becomes possible to obtain a polyimide with a small haze and favorable transparency. Moreover, since the said polyimide precursor contains the residue of the 2nd compound represented by General formula (4), the polyimide which adhesion|adherence with a support substrate is favorable, a glass transition temperature is high, a residual stress is small, and is excellent in breaking elongation. it becomes possible to obtain Therefore, when the said polyimide precursor contains both the residue of the 1st compound and the residue of the 2nd compound represented by General formula (4), adhesiveness with a support substrate is favorable, transparency is high, and a glass transition temperature is high, A polyimide having a small residual stress and excellent elongation at break can be obtained.

In general formula (4), y is computable with the following formula|equation, for example. When the compound represented by the general formula (4) satisfies the condition "It is a compound in which ^{both terminals are aminopropyl groups, and both R 6} and R ^{7 in the general formula (4) are methyl or phenyl groups"} , the following expression holds.

y={(number average molecular weight of compound represented by general formula (4))-(molecular weight of both terminal groups (aminopropyl group)=116.2)+(atomic weight of oxygen atom=16.0)}/{(general formula (4) ) repeat of the case where in R ⁶ and R ⁷ are the repeating structural molecular weight = 74.15) × (mol% of the methyl groups in the unit of the case where both a methyl group) × 0.01 + (formula 4 of R ⁶ and R ⁷ are both a phenyl group Molecular weight of structural unit = 198.29) x (mol% of phenyl group) x 0.01}-1

On the other hand, in the general formula (2), examples of the monovalent organic group having 1 to 10 carbon atoms in ^{X 1} and X ^{2 include a monovalent hydrocarbon group having 1 to 10 carbon atoms.} Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms include an alkyl group having 1 to 10 carbon atoms. Specific examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and a hexyl group.

Moreover, as ^{a C1-C10 monovalent|monohydric alkylsilyl group in X<1>} and X<^2> , the monovalent|monohydric silyl group which the C1-C10 alkyl group couple|bonded is mentioned. Specific examples of the monovalent alkylsilyl group having 1 to 10 carbon atoms include a trimethylsilyl group and a triethylsilyl group.

In General Formula (2), R<^3> is a divalent organic group represented by General formula (3) as mentioned above, Preferably it is a diamine residue. R ⁴ is a residue of an aromatic tetracarboxylic acid or a derivative thereof. It is preferable that carbon number of R<^{4> is 6-40.}

As diamine which gives R<^3> , 2,2'-bis(trifluoromethyl)-4,4'- diaminodiphenyl ether (6FODA), 2,2'-bis(trifluoromethyl), for example -3,3'-diaminodiphenyl ether and 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether are mentioned.

In general formula (2), when R ³ is a diamine residue having a structure represented by general formula (3), it has a flexible ether bond at the center of the structure of the diamine residue. For this reason, the orientation of the polyimide obtained by imidating the polyimide precursor which concerns on embodiment of this invention can be suppressed, As a result, the polyimide resin film with small in-plane/out-of-plane birefringence can be obtained. In addition, the ^{diamine residue as said R<3>} has a trifluoromethyl group which is a spinneret functional group. For this reason, the intramolecular and intermolecular electron movement in a polyimide precursor is suppressed, and it is possible to obtain a polyimide resin film with high transparency.

The polyimide precursor according to the embodiment of the present invention preferably contains 30 mol% or more of the structural unit of the divalent organic group represented by the general formula (3) among all the diamine residues contained in the polyimide precursor, and 50 mol % or more is more preferable. Moreover, although the upper limit of the content rate of the said structural unit is not specifically limited, It is preferable that it is 100 mol% or less.

^{Examples of the tetracarboxylic acid giving R 4} in the general formula (2) include pyromellitic acid, 3,3′,4,4′-biphenyltetracarboxylic acid, and 2,3,3′,4′. -biphenyltetracarboxylic acid, 2,2',3,3'-biphenyltetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, bis(3,4-dicarboxy Phenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, 2,2-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane, 9,9-bis [4- (3,4) -dicarboxyphenoxy)phenyl]fluorene, 4,4'-(hexafluoroisopropylidene)diphthalic acid, etc. are mentioned.

These tetracarboxylic acids may be used as it is, and may be used in the state of tetracarboxylic-acid derivatives, such as an acid anhydride, an active ester, and an active amide. Among these tetracarboxylic acid derivatives, acid anhydrides are preferably used because by-products do not generate during polymerization. In addition, you may use these tetracarboxylic-acid derivatives in combination of 2 or more type.

Moreover, ^{it is preferable that R<4>} in General formula (2) is a tetravalent organic group represented by following General formula (5).

In the general formula (5), Y ¹ is a direct bond or a divalent organic group having 1 to 3 carbon atoms which may be substituted with one or more selected from the group consisting of an oxygen atom, a sulfur atom, a sulfonyl group and a halogen atom, or , an ester bond, an amide bond, a carbonyl group, a sulfide bond and a divalent crosslinked structure selected from the group consisting of an organic group having 1 to 20 carbon atoms and an aromatic ring.

As a compound which provides the structure represented by General formula (5), For example, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid Acid, 2,2',3,3'-biphenyltetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, bis(3,4-dicarboxyphenyl)sulfone, bis (3,4-dicarboxyphenyl)ether, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene, 4,4'-(hexafluoroisopropylidene)diphthalic acid, etc. can be heard

^{R 4} in the general formula (2) is, among others, at least one structure selected from the structure represented by the general formula (6), the structure represented by the general formula (7), and the structure represented by the general formula (8). It is particularly preferred that it is an aromatic tetracarboxylic acid residue comprising When the said R<^4> contains the structure represented by General formula (6), the polyimide with a high glass transition temperature can be obtained. Moreover, transparency is high, and in-plane/out-of-plane birefringence is small, and the polyimide with a high glass transition temperature can be obtained because the said ^{R<4> contains the structure represented by General formula (7).} Moreover, the polyimide with high transparency and small in-plane/out-of-plane birefringence can be obtained because the said ^{R<4> contains the structure represented by General formula (8).}

The polyimide precursor according to the embodiment of the present invention preferably contains 5 mol% or more and 55 mol% or less of acid anhydride residues having a fluorene skeleton among all the acid dianhydride residues contained in the polyimide precursor, and 10 mol% or more It is more preferable to include 45 mol% or less. Thereby, a polyimide with smaller in-plane/out-of-plane birefringence can be obtained. As a structure of the acid anhydride residue which has a fluorene skeleton, the structure etc. which are represented by the said General formula (7) are mentioned.

Moreover, it is preferable that the polyimide precursor which concerns on embodiment of this invention contains the residue of the diamine represented by General formula (9).

In the general formula (9), R ⁸ is a substituted or unsubstituted phenyl group. s represents an integer of 1 or more and 4 or less.

R ⁸ is preferably a phenyl group or a phenyl group substituted with a phenyl group. For example, R ⁸ is a phenyl group or a biphenyl group.

The diamine represented by General formula (9) is a structure containing a carboxyl group necessarily. For this reason, in the polyimide precursor containing the residue of the diamine represented by General formula (9), a hydrogen bond is formed firmly intermolecularly, and intermolecular interaction becomes strong. By using such a polyimide precursor, a glass transition temperature is high and it becomes possible to obtain the polyimide excellent in mechanical strength.

Diamines represented by the general formula (9) include, for example, those represented by the following general formula (10).

Specifically, the diamine represented by General formula (10) is 3,5-diaminobenzoic acid, 3,4-diaminobenzoic acid, 2,3-diaminobenzoic acid, or 2,6-diaminobenzoic acid. In this invention, the diamine represented by General formula (9) is not limited to the specific example of these diamines represented by General formula (10).

It is preferable that the polyimide precursor which concerns on embodiment of this invention contains 1 mol% or more and 50 mol% or less of the residue of the diamine represented by General formula (9) when the quantity of the said whole polyimide precursor is 100 mol%. Moreover, it is more preferable that the said polyimide precursor contains 5 mol% or more and 40 mol% or less of the residue of the diamine represented by General formula (9), It is more preferable to contain 10 mol% or more and 35 mol% or less.

The polyimide precursor according to the embodiment of the present invention may contain a triamine skeleton. Triamine has three amino groups and forms a branched molecular chain by bonding with three tetracarboxylic dianhydride components. Triamine skeleton introduce|transduces a branched structure into the molecular chain of a polyamic acid, and forms a branched polyamic acid. Thereby, it becomes possible to improve the viscosity of the varnish which the polyimide precursor melt|dissolved, and the film thickness uniformity at the time of apply|coating to a slit can be improved. Moreover, since the molecular weight of the polyimide obtained from the polyimide precursor which has a branched structure becomes large compared with that without a branched structure, it is possible to obtain the polyimide resin film excellent in mechanical strength. A polyimide precursor having such a triamine skeleton can be obtained by using a triamine compound as one of the polymerization components.

Among the specific examples of the triamine compound, which do not have an aliphatic group, 2,4,4'-triaminodiphenyl ether (TAPE), 1,3,5-tris(4-aminophenoxy)benzene (1,3, 5-TAPOB), 1,2,3-tris(4-aminophenoxy)benzene (1,2,3-TAPOB), tris(4-aminophenyl)amine, 1,3,5-tris(4-amino) phenyl) benzene, 3,4,4'-triaminodiphenyl ether, etc. are mentioned. Moreover, tris(2-aminoethyl)amine (TAEA), tris(3-aminopropyl)amine, etc. are mentioned as a specific example of the triamine compound which has an aliphatic group.

As described above, the triamine constitutes a branch of the crosslinked structure in the molecular chain of the polyimide resin. When this triamine thermally decomposes, since the crosslinked structure of polyimide resin will be lost, as a triamine component, it is preferable to use the component which does not have an aliphatic group and is hard to thermally decompose. That is, 2,4,4'-triaminodiphenyl ether (TAPE), 1,3,5-tris (4-aminophenoxy) benzene (1,3,5-TAPOB), 1,2,3-tris It is preferable to use (4-aminophenoxy)benzene (1,2,3-TAPOB) or the like.

Moreover, the polyimide precursor which concerns on embodiment of this invention may also contain tetraamine skeleton. Tetraamine has four amino groups and forms a branched molecular chain by bonding with four tetracarboxylic dianhydride components. A tetraamine skeleton introduce|transduces a branched structure into the molecular chain of a polyamic acid, and forms a branched polyamic acid. Thereby, it becomes possible to improve the viscosity of the varnish in which the polyimide precursor melt|dissolved, and the film thickness uniformity at the time of apply|coating to a slit can be improved. Moreover, since the molecular weight of the polyimide obtained from the polyimide precursor which has a branched structure becomes large compared with the thing without a branched structure, it is possible to obtain the polyimide excellent in mechanical strength. Moreover, the glass transition temperature of a polyimide can be improved by including a tetraamine skeleton. It is considered that this is because, in part, when tetracarboxylic dianhydride and tetraamine are made to react, the benzimidazole structure with high heat resistance produces|generates. A polyimide precursor having such a tetraamine skeleton can be obtained by using a tetraamine compound as one of the polymerization components.

Specific examples of the tetraamine compound include 1,2,4,5-tetraaminobenzene, 3,3',4,4'-tetraaminobiphenyl, 3,3',4,4'-tetraaminodiphenylsulfone , 3,3',4,4'-tetraaminodiphenyl ether, 3,3',4,4'-tetraaminodiphenyl sulfide, 2,3,6,7-tetraaminonaphthalene, 1,2, 5,6-tetraaminonaphthalene etc. are mentioned. Alternatively, as a specific example of the tetraamine compound, a compound in which a part of hydrogen bonded to an aromatic ring contained in these polyvalent amine compounds or diamine compounds is substituted with hydrocarbons or halogens is exemplified.

As a tetraamine component, it is preferable to use a component which does not have an aliphatic group and is hard to thermally decompose similarly to said triamine, Furthermore, it is preferable to have an electron withdrawing group from the point of improving transparency. That is, it is preferable to use 3,3',4,4'-tetraaminodiphenylsulfone or the like.

In the present invention, the electron withdrawing group has a Hammett substituent constant (para position, σp) usually larger than 0, preferably 0.01 or more, more preferably 0.1 or more, and particularly preferably 0.5 or more. Hammett's substituent constant is described, for example, in the Japanese Chemical Society edition, "Chemical Handbook," Revised 5th Edition, Second Volume, Maruzen Co., Ltd., February 2004, page 380. Examples of the electron withdrawing group include a halogen atom, a cyano group, a hydrogen atom or a carbonyl group having a substituent, a nitro group, a perfluoroalkyl group such as a trifluoromethyl group, a sulfonyl group, and the like. Examples of the halogen atom include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom.

The polyimide precursor according to the embodiment of the present invention may contain other structural units other than the above-described structural units within a range that does not impair the effects of the present invention. As another structural unit, polyimide which is a dehydrated ring-closure of polyamic acid, polybenzoxazole which is a dehydrated ring-closure of polyhydroxyamide, etc. are mentioned.

Examples of the acid dianhydride used for the other structural unit include an aromatic acid dianhydride, an alicyclic acid dianhydride, or an aliphatic acid dianhydride described in International Publication No. 2017/099183. As a diamine compound used for another structural unit, the aromatic diamine, alicyclic diamine, or aliphatic diamine described in International Publication No. 2017/099183 is mentioned.

In addition, as for the polyimide precursor which concerns on embodiment of this invention, a part of the structural unit (For example, the structural unit represented by General formula (2)) contained in the said polyimide precursor may be imidated. By imidating a part of the said polyimide precursor, the viscosity stability at the time of room temperature storage of the resin solution containing the said polyimide precursor can be improved. As a range of the imidation ratio of the said polyimide precursor, 1 % or more and 50 % or less are preferable from a viewpoint of the solubility to a solution, and viscosity stability. The lower limit of this imidation rate becomes like this. More preferably, it is 5 % or more. Moreover, the upper limit of this imidation ratio becomes like this. More preferably, it is 30 % or less.

Examples of the polyimide precursor partially imidized include a resin having a repeating unit represented by the general formula (11), a resin having a repeating unit represented by the general formula (12), and a repeating agent represented by the general formula (13). and resins having units.

In the general formulas (11) to (13), R ⁹ represents a divalent organic group. R ¹⁰ represents a tetravalent organic group. W ¹ and W ² each independently represent a hydrogen atom, a monovalent organic group having 1 to 10 carbon atoms, or a monovalent alkylsilyl group having 1 to 10 carbon atoms. As a ^{divalent organic group of R<9>} , it is the same as that of the diamine residue mentioned above. As a tetravalent organic group of R<^10> , it is the same as that of the tetracarboxylic-acid residue mentioned above.

The weight average molecular weight (Mw) of the polyimide precursor according to the embodiment of the present invention is preferably 10,000 to 1,000,000, more preferably 10,000 to 500,000, still more preferably 20,000 to 400,000. The number average molecular weights (Mn) of the said polyimide precursor are 5,000-1,000,000, Preferably it is 5,000-500,000, Especially preferably, it is 15,000-300,000. When the weight average molecular weight and number average molecular weight of the said polyimide precursor are in the said range, it is possible to raise the intensity|strength of the polyimide resin film obtained after a cure, without worsening the coating-film flatness of the polyimide resin obtained.

In the present invention, the weight average molecular weight, number average molecular weight and molecular weight distribution are determined by TOSOH DP-8020 type GPC apparatus (guard column: TSK guard column ALPHA column: TSK-GEL α-M, developing solvent: N,N This is a value measured using '-dimethylacetamide (DMAc), 0.05M-LiCl, 0.05% phosphoric acid added).

As for the polyimide precursor which concerns on embodiment of this invention, the terminal may be sealed with the terminal blocker. By making a terminal blocker react with the terminal of the said polyimide precursor, the molecular weight of the said polyimide precursor can be adjusted to a preferable range. When the terminal monomer in the said polyimide precursor is a diamine compound, in order to seal the amino group of this diamine compound, dicarboxylic acid anhydride, monocarboxylic acid, monocarboxylic acid chloride compound, monocarboxylic acid activity Ester compounds, dialkyl dialkyl esters, and the like can be used as the terminal blocker. When the terminal monomer in the said polyimide precursor is an acid dianhydride, in order to seal the acid anhydride group of this acid dianhydride, a monoamine, monoalcohol, etc. can be used as a terminal blocker.

<Polyimide precursor composition>

The polyimide precursor which concerns on embodiment of this invention can be set as a polyimide precursor composition by mixing with an appropriate component. Although it does not specifically limit as a component which may be contained in this polyimide precursor composition, A solvent, a ultraviolet absorber, a coupling agent, a thermal crosslinking agent, an inorganic filler, surfactant, an internal release agent, a coloring agent, etc. are mentioned.

(menstruum)

There is no restriction|limiting in particular as a solvent contained in a polyimide precursor composition, A well-known thing can be used. For example, as this solvent, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutylamide, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, γ-butyrolactone, ethyl lactate, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropylene urea, 1,1,3,3-tetramethylurea, dimethyl sulfoxide, sulfolane, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, water, international publication The solvent etc. of 2017/099183 are mentioned. These can be used individually or in combination of 2 or more types. The solvent preferably contains an aprotic polar solvent such as N-methyl-2-pyrrolidone and N,N-dimethylformamide among these, and contains N-methyl-2-pyrrolidone. It is particularly preferred.

To [ the lower limit of content of the solvent in a polyimide precursor composition / 100 weight part of polyimide precursors ], Preferably it is 200 weight part or more, More preferably, it is 300 weight part or more. The upper limit of the content of the solvent is preferably 2,000 parts by weight or less, and more preferably 1,500 parts by weight or less. When the content of the solvent is in the range of 200 parts by weight or more and 2,000 parts by weight or less, the concentration and viscosity of the polyimide precursor composition become the concentration and viscosity suitable for application. As a result, when apply|coating a polyimide precursor composition with a slit coater, favorable film thickness uniformity can be acquired.

(Surfactants)

The polyimide precursor composition which concerns on embodiment of this invention may contain surfactant. Examples of the surfactant include fluorine-based surfactants such as Fluorad (trade name, manufactured by Sumitomo 3M), Megapac (trade name, manufactured by DIC Corporation), and Sulfuron (trade name, manufactured by Asahi Glass Corporation). In addition, as said surfactant, organosiloxane surfactant, such as KP341 (trade name, Shin-Etsu Chemical Co., Ltd. make), Polyflow, Glanol (trade name, Kyoesha Chemical Co., Ltd. make), BYK (made by Big Chemi), can be heard Moreover, polyoxyalkylene lauryl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, and polyoxyethylene cetyl ether surfactant, such as emulmin (made by Sanyo Kasei Kogyo Co., Ltd.), are mentioned as said surfactant. Examples of the surfactant include acrylic polymer surfactants such as Polyflow (trade name, manufactured by Kyoesha Chemical Co., Ltd.). It is preferable that content of surfactant contained in a polyimide precursor composition is 0.001 weight part or more and 1 weight part or less with respect to 100 weight part of polyimide precursors.

(Coupling agent)

In the polyimide precursor composition according to the embodiment of the present invention, a coupling agent such as a silane coupling agent or a titanium coupling agent may be added to improve adhesion with the substrate. As said coupling agent, a well-known thing can be used. In addition, the said coupling agent may use 2 or more types together. It is preferable that content of the coupling agent contained in a polyimide precursor composition is 0.01 weight% or more and 2 weight% or less with respect to 100 weight% of a polyimide precursor.

(Ultraviolet absorber)

The polyimide precursor composition which concerns on embodiment of this invention may contain the ultraviolet absorber. When the polyimide precursor composition contains a ultraviolet absorber, the polyimide obtained from the polyimide precursor composition is greatly suppressed from falling in physical properties such as transparency and mechanical properties of the polyimide when exposed to sunlight for a long period of time.

There is no limitation in particular as said ultraviolet absorber, Although a well-known thing can be used, A benzotriazole type compound, a benzophenone type compound, and a triazine type compound are used preferably from a viewpoint of transparency and non-coloring property.

It is preferable that content of the ultraviolet absorber contained in a polyimide precursor composition is 0.1 weight part or more and 10 weight part or less with respect to 100 weight part of polyimide precursors. When a polyimide precursor composition contains a ultraviolet absorber within the said range, the light resistance of the said polyimide can be improved, without impairing transparency of the polyimide obtained.

<Method for producing polyimide precursor>

A polyimide precursor can be synthesize|combined by the polymerization reaction of a diamine compound, tetracarboxylic acid, or its derivative(s), as illustrated by polyamic acid, polyamic acid ester, polyamic acid silyl ester, etc. As a derivative of tetracarboxylic acid, the acid anhydride of tetracarboxylic acid, active ester, and active amide are mentioned, for example. The reaction method of the said polymerization reaction will not be restrict|limited in particular, as long as the target polyimide precursor can be manufactured, A well-known reaction method can be used.

As a specific reaction method of the polymerization reaction, a predetermined amount of both the diamine component and the solvent are put into a reactor, the diamine component is dissolved in the solvent, and then a predetermined amount of the acid dianhydride component is introduced into the reaction vessel, The method of stirring at room temperature - 120 degreeC for 0.5 to 30 hours, etc. are mentioned. The polyimide precursor obtained by such a reaction method is good also as a polyimide precursor composition by adding components, such as the above-mentioned solvent, surfactant, internal mold release agent, and a coupling agent, suitably.

It is preferable that the moisture content in the polyimide precursor or polyimide precursor composition obtained as mentioned above is 0.05 mass % or more and 3.0 mass % or less. When the said moisture content exists in the range mentioned above, the viscosity storage stability of a polyimide precursor or a polyimide precursor composition can be improved. The moisture content here refers to the value measured by the Karl Fischer method with respect to the solution of this liquid temperature, adjusting the liquid temperature of the solution made into object to 23 degreeC. In order to measure the moisture content by the Karl Fischer method, using a Karl Fischer moisture content titration device (for example, "MKS-520" (trade name, manufactured by Kyoto Denshi Kogyo Co., etc.), etc.), based on "JIS K0068 (2001)", the capacity The moisture content is measured by a titration method.

<Polyimide>

The polyimide which concerns on embodiment of this invention is formed by imidating the said polyimide precursor. In addition, the said polyimide precursor composition adds components, such as a solvent, mentioned above to the polyimide precursor which concerns on embodiment of this invention, and contains the said polyimide precursor. That is, the polyimide which concerns on embodiment of this invention can also be synthesize|combined by imidating the said polyimide precursor composition. Below, as an example, the polyimide formed by imidating a polyimide precursor is demonstrated.

Although the method in particular of imidation is not restrict|limited, As a method of imidation in this invention, the imidation by heating and chemical imidation are mentioned. Especially, imidation by heating is preferable from a viewpoint of the heat resistance of the polyimide obtained, and transparency in a visible region.

In imidation by heating, it is preferable to heat a polyimide precursor in the range of 180 degreeC or more and 550 degrees C or less, and to convert into a polyimide. Hereinafter, imidation by heating is appropriately referred to as thermal imidization. The step of performing thermal imidization is appropriately referred to as a thermal imidization step. In the case of thermal imidization of the polyimide precursor by forming a coating film from a solution of the polyimide precursor, the thermal imidization process is a process of evaporating the solvent from the coating film of the polyimide precursor (hereinafter, appropriately referred to as a drying process), followed by any process It doesn't matter if it is done after going through

In the drying step, specifically, vacuum drying or heat drying of the coating film of the polyimide precursor is sufficient, but considering the transparency of the polyimide resin film after imidization, it is preferable to evaporate the solvent without cloudiness. A drying process WHEREIN: A hot plate, oven, infrared rays, a vacuum chamber, etc. are used for coating film drying of a polyimide precursor. The heating temperature for drying varies depending on the type and purpose of the object to be heated, and it is preferable to carry out from room temperature to 170°C for 1 minute to several hours. Although room temperature is 20-30 degreeC normally, Preferably it is 25 degreeC. In addition, you may perform a drying process multiple times on the same conditions or different conditions.

The atmosphere in the thermal imidization step is not particularly limited, and may be air, an inert gas such as nitrogen or argon. The polyimide precursor according to the embodiment of the present invention has high resistance to oxidation. For this reason, at a thermal imidation process, a transparent polyimide resin film can be obtained by heating the coating film of the said polyimide precursor for 30 minutes - 2 hours in atmospheric atmosphere using oven.

In addition, the time required until it reaches the heating temperature for thermal imidation is not specifically limited, The temperature raising method matched with the heating format of a production line can be selected. For example, you may heat the coating film of the polyimide precursor formed on the base material in oven, heating up over 5-120 minutes from room temperature to the heating temperature for thermal imidation. Or you may put the coating film of the polyimide precursor formed on the base material as it is in the oven heated up previously in the range of 180 degreeC or more and 550 degrees C or less, and may heat it. In addition, you may heat the coating film of the said polyimide precursor under reduced pressure as needed.

Although the polyimide formed by imidating a polyimide precursor was illustrated in embodiment mentioned above, this invention is not limited to this, It is also possible to obtain a polyimide by imidating a polyimide precursor composition. For example, it is possible to obtain the target polyimide by substituting "polyimide precursor composition" for "polyimide precursor" in the thermal imidation process and drying process mentioned above, and performing these each process.

The polyimide which concerns on embodiment of this invention can also be represented as a polyimide containing the structure represented by General formula (1), and the structural unit represented by General formula (14).

In general formula (1), R<^1> and R<^2> respectively independently represent a C1-C20 monovalent organic group. m represents an integer of 1 or more and 200 or less.

In the general formula (14), R ³ represents a divalent organic group represented by the general formula (3). R ⁴ represents an aromatic tetracarboxylic acid residue.

^{The detail regarding R<1>} -R<^4> in General formula (1), (14) is the same as the content demonstrated about the above-mentioned polyimide precursor.

When this polyimide makes the quantity of the said whole polyimide 100 mass %, it is preferable that 0.1 mass % or more and 30 mass % or less of the structure represented by General formula (1) are included. Moreover, it is preferable that this polyimide contains 30 mol% or more of structural units of the divalent organic group represented by General formula (3) among all the diamine residues contained in the said polyimide.

<Polyimide resin film>

The polyimide resin film according to the embodiment of the present invention is a film containing the polyimide according to the embodiment of the present invention described above. Hereinafter, the polyimide resin film which concerns on embodiment of this invention is abbreviated as "polyimide resin film" suitably.

In this invention, a polyimide resin film can be obtained by the following method, for example. As a method for forming a polyimide resin film, a coating film forming step of applying a polyimide precursor according to an embodiment of the present invention on a substrate to form a coating film, a drying step of evaporating a solvent from the coating film, and imidization of the polyimide precursor and a method including an imidization step and the like.

As a method of forming a polyimide resin film, in a coating film formation process, the coating film of a polyimide precursor is formed by apply|coating the said polyimide precursor on a board|substrate. As a method of apply|coating this polyimide precursor on a board|substrate to form a coating film, the roll coat method, the spin coat method, the slit coat method, the method of apply|coating using a doctor blade, a coater, etc. are mentioned. In addition, in a coating film formation process, you may control the thickness, surface smoothness, etc. of a coating film by repetition of application|coating. Especially, the slit-die coating method is preferable from a viewpoint of the surface smoothness of a coating film, and a film-thickness uniformity.

Although the thickness of a coating film is selected suitably according to a desired use, and is although it does not specifically limit, For example, it is 1-500 micrometers, Preferably it is 2-250 micrometers, Especially preferably, it is 5-125 micrometers. Examples of the substrate include a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, a polybutylene terephthalate (PBT) film, a silicon wafer, a glass wafer, an oxide wafer, a glass substrate, a Cu substrate, and a SUS plate. have. Especially, a glass substrate is preferable from a viewpoint of surface smoothness and dimensional stability at the time of a heating. As glass which comprises a glass substrate, an alkali free glass is especially preferable from a viewpoint of dimensional stability.

Then, in a drying process, this coating film is dried by evaporating a solvent from the coating film on a board|substrate. Specifically, in this drying step, the coating film may be dried by vacuum drying or heat drying, but considering the transparency of the polyimide resin film after imidization, it is preferable to evaporate the solvent without cloudiness. A hot plate, oven, infrared rays, a vacuum chamber, etc. are used for drying of the coating film in a drying process.

The heating temperature for drying varies depending on the type and purpose of the object to be heated, such as a coating film, and it is preferable to carry out from room temperature to 170 degreeC for 1 minute to several hours. It is 20-30 degreeC normally from room temperature, Preferably it is 25 degreeC. In addition, you may perform a drying process multiple times on the same conditions or different conditions.

Then, imidation process WHEREIN: The polyimide precursor in the coating film on a board|substrate is imidated, and, thereby, a polyimide resin film is formed on a board|substrate. The polyimide resin film obtained through each of the above steps can be used by peeling from the substrate, or can be used as it is without peeling.

Although the thickness of the polyimide resin film obtained as mentioned above is suitably selected according to a desired use, Preferably it is 1-100 micrometers, More preferably, it is 5-30 micrometers, Especially preferably, it is 7-20 micrometers.

Although the above-mentioned embodiment illustrated the polyimide resin film formed by imidating the coating film of a polyimide precursor, this invention is not limited to this, It is also possible to obtain a polyimide resin film by imidating the coating film of a polyimide precursor composition. . For example, the target polyimide resin film can be obtained by substituting "polyimide precursor composition" for "polyimide precursor" in each process, such as the thermal imidation process mentioned above, and performing each said process.

It is preferable that it is 240 degreeC or more, and, as for the glass transition temperature of the polyimide resin film (namely, the polyimide resin film which concerns on embodiment of this invention) obtained by making it above, it is more preferable that it is 250 degreeC or more.

Further, the density of the polyimide resin film according to the embodiment of the present invention is preferably 1.20 g/cm 3 or more and 1.43 g/cm 3 or less, and more preferably 1.23 g/cm 3 or more and 1.40 g/cm 3 or less. The density of the polyimide resin film is correlated with the intermolecular interaction, and the stronger the intermolecular interaction, the higher the density. Therefore, when the density of a polyimide resin film is high, it is possible to obtain a polyimide resin film with a high glass transition temperature. On the other hand, when the intermolecular interaction is weak, voids are formed between molecules, so that a polyimide resin film having a small in-plane/out-of-plane birefringence can be obtained. In addition to this, since the internal stress is relieved by this void, it is possible to suppress the warpage of the substrate constituted of the polyimide resin film. Therefore, when the density of the polyimide resin film is 1.20 g/cm 3 or more and 1.43 g/cm 3 or less, since the intermolecular interaction is in a preferable range, the glass transition temperature is high, the in-plane/out-of-plane birefringence is small, and the warpage of the substrate can be suppressed. A polyimide resin film can be obtained.

Moreover, it is preferable that it is 0.01 or less, and, as for the in-plane/out-of-plane birefringence of the polyimide resin film which concerns on embodiment of this invention, it is more preferable that it is 0.005 or less. When the in-plane/out-of-plane birefringence of the polyimide resin film is 0.01 or less, color separation when viewed from an oblique direction can be prevented, or external light reflection when a circularly polarizing film is used can be suppressed.

Moreover, it is preferable that the yellowness of the polyimide resin film which concerns on embodiment of this invention is 3 or less. When the yellowness degree of a polyimide resin film is 3 or less, the flexible board|substrate which suppressed yellowness can be formed. Furthermore, by using this flexible substrate, preparation of the flexible device which suppressed yellowness is possible.

<Use>

The polyimide precursor, polyimide, and polyimide resin film containing the polyimide precursor according to the embodiment of the present invention can be used for an electronic device. More specifically, it can be used for a liquid crystal display, an organic EL display, a touch panel, an electronic paper, a color filter, a display device such as a microLED display, a solar cell, a light receiving device such as CMOS, and the like. It is preferable that these electronic devices are flexible devices. The flexible device which concerns on embodiment of this invention is equipped with the above-mentioned polyimide resin film. The polyimide resin film mentioned above is used suitably as a board|substrate in electronic devices, such as the said flexible device, especially a flexible board|substrate.

Example

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited by the following examples and the like. First, materials used in the following examples and comparative examples, measurements and evaluations performed, and the like will be described.

<Material>

As the acid dianhydride, those shown below are suitably used.

ODPA: 3,3',4,4'-diphenylethertetracarboxylic dianhydride

BPAF: 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorenedioic anhydride

X-22-168-P5-B: both terminal carboxylic acid anhydride-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical, number average molecular weight 4,200, y=34 to 38, phenyl group:methyl group=25:75 mol%)

CBDA: Cyclobutanetetracarboxylic dianhydride

As a diamine compound, what is shown below is used suitably.

6FODA: bis(trifluoromethyl)-4,4'-diaminodiphenyl ether

CHDA: trans-1,4-diaminocyclohexane

TFMB: 2,2'-bis(trifluoromethyl)benzidine

SiDA: 1,3-bis(3-aminopropyl)tetramethyldisiloxane

X-22-9409: both terminal amine-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical, number average molecular weight 1,340, y=10 to 11, phenyl group:methyl group=25:75 mol%)

X22-1660B-3: both terminal amine-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical, number average molecular weight 4,400, y = 39 to 41, phenyl group: methyl group = 25: 75 mol%)

As a solvent, what is shown below is used suitably.

NMP: N-methyl-2-pyrrolidone

GBL: γ-butyrolactone

MMBAc: 3-methoxy-3-methyl-1-butylacetate

<Evaluation>

(Item 1: Preparation of polyimide resin film (on the first glass substrate))

In the 1st item, the manufacturing method of a polyimide resin film (on a 1st glass substrate) is demonstrated. In the production of the polyimide resin film in the first item, the varnish produced in each of the following examples and each comparative example was applied to an alkali-free glass substrate with a thickness of 100 mm x 100 mm x 0.5 mm (AN-100 manufactured by Asahi Glass Corporation). Then, using a spin coater (MS-A200) manufactured by Mikasa Corporation, it applied so that the cured film thickness was 10±0.5 µm. Then, the coating film prebaking of the varnish was performed using the hot plate. The hot plate dried the coating film of the varnish over 6 minutes using what was previously heated at 120 degreeC. With respect to the prebaked film thus obtained, using an oven ("IHPS-222"; manufactured by SPEC Co., Ltd.), it is cured in air at 240°C for 60 minutes, whereby the alkali-free glass substrate (first glass) is used. A polyimide resin film was produced on the substrate).

(Second item: Preparation of polyimide resin film (release film))

In the 2nd item, the manufacturing method of a polyimide resin film (release film) is demonstrated. In the production of the polyimide resin film in the second item, the polyimide resin film (on the first glass substrate) shown in the first item was cut into a portion 1 cm from the edge of the four sides with a single blade, and heated to 60 ° C. It was immersed in warm water for 60 minutes. Then, this polyimide resin film was peeled from a 1st glass substrate, and the polyimide resin film as a peeling film was thereby obtained.

(Item 3: Preparation of polyimide resin film (on the second glass substrate))

In the 3rd item, the manufacturing method of a polyimide resin film (on a 2nd glass substrate) is demonstrated. In preparation of the polyimide resin film in the 3rd item, it carried out similarly to the said 1st item, except having used the 50 mm x 50 mm x 1.1 mm-thick glass substrate (Tempax) as a 2nd glass substrate, and a 2nd glass substrate A polyimide resin film was produced thereon.

(Item 4: Preparation of polyimide resin film (on the third glass substrate))

In the 4th item, the manufacturing method of a polyimide resin film (on a 3rd glass substrate) is demonstrated. In the production of the polyimide resin film in the fourth item, the varnish produced in each of the following examples and each comparative example was applied to a glass substrate having a thickness of 730 mm × 920 mm × 0.5 mm as a third glass substrate (AN manufactured by Asahi Glass Corporation). -100) using a slit coater (manufactured by Toray Engineering, Inc.) so that the cured film thickness was 10±0.5 µm. Then, the coating film prebaking of the varnish was performed using the heating type vacuum dryer and a hot plate. The heated vacuum dryer heated the upper plate to 60° C. and the lower plate to 40° C., and dried the coating film of the varnish under conditions in which the internal pressure was lowered to 60 Pa over 150 seconds. The hot plate dried the coating film of the varnish over 6 minutes using what was previously heated at 120 degreeC. With respect to the prebaked film|membrane obtained in this way, using oven, it cured at 240 degreeC in air for 60 minutes, and by this, the polyimide resin film was produced on the 3rd glass substrate.

(Item 5: Preparation of polyimide resin film (on silicon substrate))

In the 5th item, the manufacturing method of a polyimide resin film (on a silicon substrate) is demonstrated. In the production of the polyimide resin film in item 5, the varnish produced in each of the following examples and comparative examples was applied on a 6-inch silicon substrate using a coating and developing device (Mark-7) manufactured by Tokyo Electron Corporation. Spin coating was performed so that the film thickness after curing was set to 10±0.5 µm. Then, the prebaking process for 120 degreeC x 6 minutes was performed with respect to the coating film of the varnish on this silicon substrate using the hotplate of Mark-7. With respect to the prebaked film|membrane obtained in this way, using oven, it cured in air at 240 degreeC for 60 minute(s), and thereby produced the polyimide resin film on a silicon substrate.

(Section 6: Measurement of Density)

In the 6th item, the density measurement of a polyimide resin film is demonstrated. In the measurement of the density in the sixth item, the polyimide resin film (release film) shown in the second item is cut into a size of 40 mm x 40 mm to be a measurement sample, and a specific gravity measurement kit (AD-1653-BM, A. and D's) was used to measure the density of the measurement sample by the Archimedes method in an atmosphere of room temperature 25°C and relative humidity 65%. At this time, the immersion liquid which immersed the measurement sample was made into water. The measurement of the density was performed twice with respect to one measurement sample, and the average value was made into the density (g/cm<3>) of the measurement sample.

(Item 7: Measurement of in-plane/out-of-plane birefringence)

In the 7th item, the measurement of in-plane/out-of-plane birefringence of a polyimide resin film is demonstrated. In the measurement of in-plane/out-of-plane birefringence in item 7, using a prism coupler (manufactured by METRICON, PC2010), the TE refractive index (n(TE)) and TM refractive index (n(TM)) at a wavelength of 632.8 nm were measured. . n(TE) and n(TM) are the refractive indices in the parallel direction and the perpendicular direction with respect to the surface of the polyimide resin film, respectively. In-plane/out-of-plane birefringence was calculated as the difference (n(TE)-n(TM)) between n(TE) and n(TM). In addition, the polyimide resin film (release film) shown in the said 2nd item was used for this measurement. In addition, about in-plane/out-of-plane birefringence, the following evaluation method performed judgment of excellent, excellent, good, and defectiveness.

Excellent (A): in-plane/out-of-plane birefringence less than 0.0021

Good (B): In-plane/out-of-plane birefringence 0.0021 or more and less than 0.0030

Good (C): In-plane/out-of-plane birefringence 0.0030 or more and less than 0.0050

Poor (D): In-plane/out-of-plane birefringence of 0.0050 or more

(Item 8: Measurement of Yellowness)

In the 8th item, the measurement of the yellowness of a polyimide resin film is demonstrated. In the measurement of the yellowness in the eighth item, the yellowness of the polyimide resin film was measured using a color meter (SM-T45, manufactured by Suga Industrial Co., Ltd.). C light source was used as the light source, and the measurement of yellowness was performed in transmitted light mode. In addition, the polyimide resin film (on a 2nd glass substrate) shown in said 3rd item was used for this measurement.

(Item 9: Measurement of haze value)

In the 9th item, the measurement of the haze value of a polyimide resin film is demonstrated. In the measurement of the haze value in the ninth item, the haze value (%) of the polyimide resin film (on the second glass substrate) shown in the third item using a direct-reading haze computer (HGM2DP, C light source manufactured by Suga Industrial Co., Ltd.) ) was measured. In addition, as each value, the average value of three measurements was used.

(Item 10: Measurement of 1% Weight Loss Temperature (Td1))

In the tenth item, the measurement of the 1% weight loss temperature of the polyimide resin film will be described. In the measurement of the 1% weight loss temperature in the tenth item, measurement was performed under a nitrogen stream using a thermogravimetric measuring apparatus (TGA-50 manufactured by Shimadzu Corporation). The temperature increase method was performed under the following conditions. In the first step, the temperature was raised to 150° C. at a temperature increase rate of 3.5° C./min to remove the sample adsorbed water in the polyimide resin film, and in the second step, the temperature was cooled to room temperature at a temperature drop rate of 5° C./min. In the third step, this measurement was performed at a temperature increase rate of 10° C./min to determine the 1% thermogravimetric reduction temperature of the polyimide resin film. In addition, the polyimide resin film (release film) shown in the said 2nd item was used for this measurement.

(Item 11: Measurement of Glass Transition Temperature (Tg))

In the 11th item, the measurement of the glass transition temperature of a polyimide resin film is demonstrated. In the measurement of the glass transition temperature in the eleventh item, measurement was performed under a nitrogen stream using a thermomechanical analyzer (EXSTAR6000TMA/SS6000 manufactured by SII Nanotechnology Co., Ltd.). The temperature increase method was performed under the following conditions. In the first step, the temperature was raised to 150° C. at a temperature increase rate of 5° C./min, the sample adsorbed water of the polyimide resin film was removed, and in the second step, it was air-cooled to room temperature at a temperature drop rate of 5° C./min. In the third step, this measurement was performed at a temperature increase rate of 5°C/min, and the glass transition temperature of this sample was determined. In addition, the polyimide resin film (release film) shown in the said 2nd item was used for this measurement.

(Item 12: Measurement of Elongation at Break)

In the 12th item, the measurement of the breaking elongation of a polyimide resin film is demonstrated. In the measurement of elongation at break in the 12th item, the polyimide resin film (release film) shown in the second item was cut into a rectangle with a width of 1 cm and a length of 9 cm as a sample, and Tensilon (RTM- manufactured by Orientec) 100) was used to pull the sample, and the breaking elongation was measured. At this time, the tension|pulling of the sample was performed with the initial length of the said sample being 50 mm, and the tension rate of 50 mm/min in the environment of room temperature 23.0 degreeC and humidity 45.0%RH. The measurement of elongation at break was performed for ten samples for each specimen of one polyimide resin film, and the average value of the top 5 points among the measurement results of these ten samples was determined as elongation at break. In addition, about the breaking elongation, the following evaluation methods judged excellent, excellent, favorable, and defectiveness.

Excellent (A): Elongation at break of 40% or more

Good (B): Elongation at break 25% or more and less than 40%

Good (C): Elongation at break of 10% or more and less than 25%

Poor (D): Elongation at break less than 10%

(Item 13: Measurement of residual stress)

Section 13 describes the measurement of residual stress of the polyimide resin film. In the measurement of the residual stress in the 13th item, the measurement was performed using a thin film stress measuring device (FLX-3300-T) manufactured by KLA Tenko. The polyimide resin film (on a silicon substrate) shown in the said 5th item was used for this measurement. At this time, the polyimide resin film is dehydrated by heating at 150°C for 30 minutes in a nitrogen atmosphere before measurement, and then cooled to 30°C in a nitrogen atmosphere, and the residue of the polyimide resin film after drying at 30°C. The stress was measured.

(Item 14: Measurement of substrate warpage)

In the 14th item, the measurement of board|substrate warpage is demonstrated. In the measurement of substrate warpage in Item 14, the test plate was placed on a precision stone plate (1000 mm x 1000 mm) manufactured by Mitsutoyo Co., Ltd. so that the glass of the test plate and the precision stone plate were in contact with each other. At this time, the test plate was made into the polyimide resin film (on a 3rd glass substrate) shown in the said 4th item. After that, the amount (distance) in which the test plate is suspended with a precision granite plate is measured using a gap gauge for a total of 8 points of each midpoint and each vertex of the four sides of the test plate, and the average value of these values is calculated as the amount of deflection of the test plate, that is, It was set as the amount of board|substrate curvature. In addition, this measurement was performed in the environment of 23 degreeC of room temperature and 55% of humidity. In addition, about board|substrate curvature, the following evaluation methods performed judgment of excellent, excellent, favorable, and defectiveness.

Excellent (A): substrate warpage less than 0.21 mm

Good (B): Substrate warpage is 0.21 mm or more and less than 0.28 mm

Good (C): substrate warpage is 0.28 mm or more and less than 0.35 mm

Defect (D): substrate warpage of 0.35 mm or more

(Item 15: Measurement of Substrate Adhesion (90° Peel Test))

In the 15th item, the measurement of the board|substrate adhesive force is demonstrated. In the measurement of the substrate adhesion force in the 15th item, the polyimide resin film (on the first glass substrate) shown in the first item is cut out to a width of 10 mm and a length of 100 mm to be a measurement sample, and the measurement sample is hot After performing the dehydration baking process at 120 degreeC x 6 minutes using the plate, the 90 degree peel test was done on the conditions of 50 mm/min of tensile speed|rate. In this 90 degree peel test, the polyimide resin with respect to the 1st glass substrate in a measurement sample using the adhesive tester (made by Yamamoto Plating Test Co., Ltd.) based on JIS C6481 (1996, copper clad laminated board test method for printed wiring boards) The 90° peel strength (N/cm) of the film was measured. In addition, about the board|substrate adhesive force of a polyimide resin film, based on the measurement result of the said 90 degree peeling strength, the following evaluation methods judged excellent, excellent, favorable, and defectiveness.

Excellent (A): 90° peel strength of 1.5 N/cm or more

Excellent (B): 90° peel strength of 1.0 N/cm or more and less than 1.5 N/cm

Good (C): 90° peel strength of 0.5 N/cm or more and less than 1.0 N/cm

Poor (D): 90° peel strength less than 0.5 N/cm

(Item 16: Manufacturing and Appearance Check of Laminate)

In the 16th item, manufacture of a laminated body and external appearance confirmation are demonstrated. In the production and appearance confirmation of the laminate in the 16th item, a plasma SiON film (film forming temperature: 240°C, film thickness: 100 nm) on the polyimide resin film (on the third glass substrate) shown in the 4th item above It was formed into a film by CVD. Thereby, the laminated body of the said polyimide resin film and the SiON film was produced. Then, the external appearance of the said laminated body was confirmed using the optical microscope (The Nikon company make, OPTIPHOT300) at 50 times magnification. In addition, about the external appearance confirmation of this laminated body after manufacture, the following evaluation methods performed judgment of excellent, excellent, good, and defectiveness.

Excellent (A): No wrinkles were seen on the entire surface of the laminate, and the surface of the laminate was smooth

Good (B): generation of wrinkles is seen in a part of the laminate, but the area of the location of occurrence of wrinkles is 5% or less of the entire surface of the laminate

Good (C): Although generation|occurrence|production of wrinkles is seen in a part of laminated body, the area of the generation|occurrence|production location of wrinkles is 15% or less of the whole surface of a laminated body

Defect (D): the area of the wrinkle occurrence location exceeds 30% of the total surface of the laminate

(Item 17: Production of a color filter using a laminate)

In the 17th item, manufacture of the color filter using the laminated body containing a polyimide resin film is demonstrated. In preparation of the color filter in the 17th item, preparation of a resin black matrix and preparation of a colored layer were performed by the method shown below, and the target color filter was produced through these processes.

(Production Example 1: Preparation of resin black matrix)

In Production Example 1, a black resin composition (for resin black matrix) containing a polyamic acid in which a black pigment is dispersed is spin-coated on the SiON film of the laminate shown in the 16th item, and the black resin composition The coating film was dried on a hotplate at 130 degreeC for 10 minutes, and the black resin coating film was formed. Next, a positive photoresist (manufactured by Ciple, "SRC-100") is spin-coated on the black resin coating film, and this positive photoresist is prebaked on a hot plate at 120° C. for 5 minutes, followed by ultra-high pressure Using a mercury lamp, UV irradiation was carried out under the conditions of 100 mJ/cm<2> (i-ray conversion), and mask exposure was carried out. Thereafter, using a 2.38% aqueous solution of tetramethylammonium hydroxide, this positive photoresist was developed and the black resin coating film was etched at the same time, thereby forming a pattern of the black resin coating film. Thereafter, this positive photoresist was peeled with methyl cellosolve acetate, and the patterned black resin coating film was imidized by heating in an oven at 240° C. for 60 minutes, and resin black in which carbon black was dispersed in polyimide resin. A matrix was formed. In manufacture example 1, the resin laminated body provided with the resin black matrix by which the pattern process was carried out as mentioned above on the SiON film of the said laminated body was obtained. When the thickness of this resin black matrix was measured, it was 1.4 micrometers.

(Production Example 2: Preparation of colored layer)

In Production Example 2, an acrylic resin photosensitive resist was spin-coated to the resin laminate in which the resin black matrix was patterned, produced in Production Example 1, so that the film thickness at the opening of the black matrix after heat treatment was 2.0 μm. , prebaked at 100°C for 10 minutes on a hot plate. Thereby, a red colored layer was obtained. Next, using an ultraviolet light exposure machine (PLA-5011 Canon Co., Ltd.), the acrylic resin photosensitive resist in the black matrix opening and a part of the resin black matrix is passed through a chrome photomask through which light is transmitted in an island shape, It exposed under the conditions of 100 mJ/cm<2> (i-line conversion). The acrylic resin photosensitive resist after this exposure was developed by immersing it in a developer containing 0.2% tetramethylammonium hydroxide aqueous solution. Then, the said red colored layer was heat-processed in 230 degreeC oven for 30 minutes after pure water washing|cleaning, and thereby, the red pixel was produced. In the same manner, a green pixel containing an acrylic resin photosensitive rust resist and a blue pixel containing an acrylic resin photosensitive blue resist were produced. As a result, the target color filter was obtained. Then, the rotation speed of the spinner was adjusted so that the thickness in the colored layer part after heat processing might be set to 2.5 micrometers, and the transparent resin composition was apply|coated on these pixels and the resin black matrix. Then, the coating film of this transparent resin composition was heat-processed in 230 degreeC oven for 30 minutes, and, thereby, the overcoat layer was produced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows one structural example of the color filter containing the polyimide resin film which concerns on embodiment of this invention. As shown in FIG. 1 , this color filter 6 includes a polyimide resin film 1 and a gas barrier layer 2 . The polyimide resin film 1 is an example of the polyimide resin film according to the embodiment of the present invention, and is produced, for example, by a method indicated by any one of the first to fifth items described above. The gas barrier layer 2 is a layer which protects the polyimide resin film 1 from gas, such as oxygen, and is comprised by the SiON film|membrane shown in the 16th item mentioned above, for example. As shown in FIG. 1 , the gas barrier layer 2 is formed on the polyimide resin film 1 . These polyimide resin films 1 and gas barrier layer 2 constitute the laminate shown in the above-mentioned 16th item.

Further, as shown in FIG. 1 , the color filter 6 includes a black matrix 3 , a red pixel 4R, a green pixel 4G, and a blue pixel 4B on the gas barrier layer 2 . ) and an overcoat layer (5). The black matrix 3 is a resin black matrix formed on the gas barrier layer 2 by the method shown in manufacture example 1 mentioned above, for example. The red pixel 4R is a red colored pixel. The green pixel 4G is a green colored pixel. The blue pixel 4B is a blue colored pixel. These red pixels 4R, green pixels 4G, and blue pixels 4B are respectively formed by, for example, the method shown in Production Example 2 described above. The overcoat layer 5 is a layer covering the black matrix 3, the red pixel 4R, the green pixel 4G, and the blue pixel 4B, and is formed, for example, by the method shown in Production Example 2 described above.

(Item 18: Confirmation of peeling of black matrix and colored pixels)

In the 18th item, peeling confirmation of a black matrix and a color pixel is demonstrated. In the confirmation of peeling of the black matrix and the colored pixel in the 18th item, the appearance (presence or absence of peeling) of the black matrix and the colored pixel of the color filter shown in the 17th item was measured using an optical microscope (manufactured by Nikon, OPTIPHOT300). It was confirmed with a magnification of 50 times. In addition, about these peeling confirmation, the following evaluation methods judged excellent, excellent, favorable, and defectiveness.

Excellent (A): No peeling of black matrix and colored pixels

Good (B): There is peeling in a part of a black matrix and a colored pixel (the ratio of the said peeling with respect to the whole black matrix and a colored pixel: less than 5 %)

Good (C): There is peeling in a part of a black matrix and a colored pixel (the ratio of the said peeling with respect to the whole black matrix and a colored pixel: more than 5 % and less than 15 %)

Defect (D): There is peeling in a part of a black matrix and a colored pixel (the ratio of the said peeling with respect to the whole black matrix and a colored pixel: 15% or more)

(Example 1)

In Example 1, in a 200 ml four-necked flask under a stream of dry nitrogen, 6FODA (12.60 g (37.5 mmol)), X-22-9409 (4.48 g (3.35 mmol)), and ODPA (12.79 g (41.2 mmol)) )) and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 2)

In Example 2, 6FODA (15.29 g (45.5 mmol)), SiDA (0.15 g (0.60 mmol)), ODPA (14.43 g (46.5 mmol)) and ODPA (14.43 g (46.5 mmol)) in a 200 mL four-necked flask under a dry nitrogen stream; NMP (100 g) was put, and it heat-stirred at 80 degreeC. After 5 hours, it was cooled and set as a varnish.

(Example 3)

In Example 3, 6FODA (12.75 g (37.9 mmol)), X-22-1660B-3 (1.78 g (0.40 mmol)), and X-22-9409 in a 200 ml four-necked flask under a dry nitrogen stream. (2.70 g (2.02 mmol)), ODPA (12.64 g (40.8 mmol)), and NMP (100 g) were put, and it heated and stirred at 80 degreeC. After 5 hours, it was cooled and set as a varnish.

(Example 4)

In Example 4, 6FODA (12.81 g (38.1 mmol)), X-22-1660B-3 (2.30 g (0.52 mmol)), and X-22-9409 were placed in a 200 ml four-necked flask under a stream of dry nitrogen. (2.16 g (1.61 mmol)), ODPA (12.61 g (40.6 mmol)), and NMP (100 g) were put, and it heat-stirred at 80 degreeC. After 5 hours, it was cooled and set as a varnish.

(Example 5)

In Example 5, 6FODA (12.84 g (38.2 mmol)), X-22-1660B-3 (3.50 g (0.80 mmol)), and X-22-9409 were placed in a 200 ml four-necked flask under a stream of dry nitrogen. (1.07 g (0.80 mmol)), ODPA (12.46 g (40.2 mmol)), and NMP (100 g) were put, and it heat-stirred at 80 degreeC. After 5 hours, it was cooled and set as a varnish.

(Example 6)

In Example 6, in a 200 ml four-neck flask under a stream of dry nitrogen, 6FODA (8.78 g (26.1 mmol)), BAFL (4.14 g (11.9 mmol)), and X-22-1660B-3 (3.48 g ( 0.79 mmol), X-22-9409 (1.06 g (0.79 mmol)), ODPA (12.40 g (40.0 mmol)), and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 7)

In Example 7, 6FODA (12.87 g (38.3 mmol)), X-22-1660B-3 (2.25 g (0.51 mmol)), and X-22-9409 were placed in a 200 ml four-necked flask under a stream of dry nitrogen. (0.68 g (0.51 mmol)), ODPA (8.62 g (27.8 mmol)), BPAF (5.46 g (11.9 mmol)), and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 8)

In Example 8, 6FODA (12.01 g (35.8 mmol)), X-22-1660B-3 (3.45 g (0.78 mmol)), and X-22-9409 were placed in a 200 ml four-necked flask under a stream of dry nitrogen. (1.05 g (0.78 mmol)), ODPA (8.18 g (26.4 mmol)), BPAF (5.18 g (11.3 mmol)), and NMP (100 g) were put, and heat-stirred at 80 degreeC. After 5 hours, it was cooled and set as a varnish.

(Example 9)

In Example 9, 6FODA (7.87 g (23.4 mmol)), 3,5-DABA (2.54 g (16.7 mmol)) and X-22-1660B-3 in a 200 ml four-necked flask under a stream of dry nitrogen. (3.48 g (0.79 mmol)), X-22-9409 (1.06 g (0.79 mmol)), ODPA (9.14 g (29.5 mmol)), and BPAF (5.79 g (12.6 mmol)), and NMP (100 g) ) and heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 10)

In Example 10, 6FODA (10.06 g (29.9 mmol)), 3,5-DABA (1.20 g (7.87 mmol)) and X-22-1660B-3 were placed in a 200 ml four-neck flask under a dry nitrogen stream. (3.46 g (0.79 mmol)) and X-22-9409 (1.06 g (0.79 mmol)), ODPA (8.63 g (27.8 mmol)), and BPAF (5.47 g (11.9 mmol)), and NMP (100 g) ) and heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 11)

In Example 11, 6FODA (11.11 g (33.0 mmol)), 3,5-DABA (0.59 g (3.84 mmol)), and X-22-1660B-3 in a 200 ml four-necked flask under a stream of dry nitrogen. (3.38 g (0.77 mmol)), X-22-9409 (1.03 g (0.77 mmol)), ODPA (8.43 g (27.2 mmol)), and BPAF (5.34 g (11.6 mmol)), and NMP (100 g) ) and heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 12)

In Example 12, 6FODA (11.15 g (33.2 mmol)), X-22-1660B-3 (4.66 g (1.06 mmol)), and X-22-9409 were placed in a 200 ml four-necked flask under a stream of dry nitrogen. (1.42 g (1.06 mmol)), ODPA (7.74 g (25.0 mmol)), BPAF (4.90 g (10.7 mmol)), and NMP (100 g) were put, and it heat-stirred at 80 degreeC. After 5 hours, it was cooled and set as a varnish.

(Example 13)

In Example 13, 6FODA (10.38 g (30.9 mmol)), X-22-1660B-3 (5.75 g (1.31 mmol)), and X-22-9409 were placed in a 200 ml four-necked flask under a stream of dry nitrogen. (1.75 g (1.31 mmol)), ODPA (7.34 g (23.7 mmol)), BPAF (4.65 g (10.2 mmol)), and NMP (100 g) were put, and heat-stirred at 80 degreeC. After 5 hours, it was cooled and set as a varnish.

(Example 14)

In Example 14, 6FODA (9.61 g (28.6 mmol)), X-22-1660B-3 (6.83 g (1.55 mmol)), and X-22-9409 were placed in a 200 ml four-neck flask under a stream of dry nitrogen. (2.08 g (1.55 mmol)), ODPA (6.95 g (22.4 mmol)), BPAF (4.40 g (9.60 mmol)), and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 15)

In Example 15, in a 200 ml four-neck flask under a stream of dry nitrogen, 6FODA (13.15 g (39.1 mmol)), X-22-9409 (1.07 g (0.80 mmol)), and ODPA (12.26 g (39.5 mmol)) )), X-22-168-P5-B (3.39 g (0.81 mmol)), and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 16)

In Example 16, 6FODA (13.22 g (39.3 mmol)), ODPA (11.98 g (38.6 mmol)), and X-22-168-P5-B (4.67) were placed in a 200 ml four-necked flask under a stream of dry nitrogen. g (1.11 mmol)) and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Example 17)

In Example 17, in a 200 ml four-neck flask under a stream of dry nitrogen, 6FODA (12.95 g (38.5 mmol)), X-22-1660B-3 (4.53 g (1.03 mmol)), and ODPA (12.39 g (12.39 g ( 40.0 mmol)) and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Comparative Example 1)

In Comparative Example 1, TFMB (12.31 g (38.4 mmol)), X-22-9409 (4.48 g (3.34 mmol)) and ODPA (13.09 g (42.2 mmol)) were placed in a 200 ml four-neck flask under a stream of dry nitrogen. )) and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

(Comparative Example 2)

In Comparative Example 2, 6FODA (15.46 g (46.0 mmol)), ODPA (14.41 g (46.4 mmol)), and NMP (100 g) were put in a 200 ml four-necked flask under a dry nitrogen stream, and heated at 80 ° C. stirred. After 5 hours, it was cooled and set as a varnish.

(Comparative Example 3)

In Comparative Example 3, 6FODA (15.58 g (46.3 mmol)), X-22-9409 (4.46 g (3.33 mmol)) and CBDA (9.84 g (50.2 mmol)) were placed in a 200 ml four-necked flask under a stream of dry nitrogen. )) and NMP (100 g) were put, and the mixture was heated and stirred at 80°C. After 5 hours, it was cooled and set as a varnish.

Using each of the varnishes of Examples 1 to 17 and Comparative Examples 1 to 3, as shown in the above items 1 to 18, a polyimide resin film, a laminate comprising the same, and a color filter were prepared, and Measurement and evaluation were performed. The results of Examples 1 to 17 and Comparative Examples 1 to 3 are shown in Tables 1-4. In addition, each varnish synthesized in Examples 1 to 17 and Comparative Examples 1 to 3 was used by filtering through a filter made of ethylene tetrafluoride resin (PTFE) having a pore diameter of 1 µm, respectively. However, in the comparative example 2, since the SiON film|membrane could not be formed into a film on the polyimide resin film at the point with large board|substrate curvature, evaluation after laminated body formation could not be implemented.

As shown in Tables 1 to 4, in Examples 1 to 17 of the present invention, there was no result of defectiveness in all of the evaluations made as objects. On the other hand, in Comparative Examples 1-3 with respect to this invention, at least 1 of the evaluation made into object was a result that it was defective. Specifically, evaluation of in-plane/out-of-plane birefringence in Comparative Example 1, evaluation of substrate warpage and evaluation of substrate adhesion force in Comparative Example 2, and evaluation of elongation at break in Comparative Example 3 and formation of a laminate About the external appearance evaluation, it was a result called defect. In particular, in Comparative Example 1, since TFMB having high linearity was used, it is considered that the orientation of the polyimide advanced and the in-plane/out-of-plane birefringence of the resulting polyimide resin film became large. In Comparative Example 3, since CBDA, which is an alicyclic acid dianhydride, was used, oxidative decomposition proceeded and yellowed when curing was performed in an atmospheric atmosphere.

As described above, the polyimide precursor, polyimide, polyimide resin film, and flexible device according to the present invention have high transparency, high glass transition temperature, low in-plane/out-of-plane birefringence, and good adhesion to the support substrate. It is suitable for providing a polyimide resin film and flexible device using this polyimide efficiently.

1: polyimide resin film
2: gas barrier layer
3: Black Matrix
4R: red pixel
4G: green pixel
4B: blue pixel
5: overcoat layer
6: color filter

Claims (16)

A polyimide precursor comprising a structure represented by the general formula (1) and a structural unit represented by the general formula (2).

(In general formula (1), R ¹ and R ² each independently represent a monovalent organic group having 1 to 20 carbon atoms. m represents an integer of 1 or more and 200 or less.)

(In the general formula (2), R ³ represents a divalent organic group represented by the general formula (3). R ⁴ represents an aromatic tetracarboxylic acid residue. X ¹ and X ² are each independently a hydrogen atom; It represents a monovalent organic group having 1 to 10 carbon atoms or a monovalent alkylsilyl group having 1 to 10 carbon atoms.)

The polyimide precursor according to claim 1, wherein when the total amount of the polyimide precursor is 100 mass %, 0.1 mass % or more and 30 mass % or less of the structure represented by the general formula (1) is included. The polyimide according to claim 1 or 2, wherein the polyimide contains 30 mol% or more of structural units of divalent organic groups represented by the general formula (3) among all the diamine residues contained in the polyimide precursor. precursor. The polyi according to any one of claims 1 to 3, wherein the polyimide comprises 5 mol% or more and 55 mol% or less of acid anhydride residues having a fluorene skeleton among all the acid dianhydride residues contained in the polyimide precursor. mid precursor. The polyimide precursor according to any one of claims 1 to 4, comprising a residue of a compound represented by the following general formula (4).

(In the general formula (4), a plurality of R ⁵ are each independently a single bond or a divalent organic group having 1 to 10 carbon atoms. A plurality of R ⁶ and R ⁷ are each independently a monovalent group having 1 to 3 carbon atoms. It is an aliphatic hydrocarbon group or an aromatic group having 6 to 10 carbon atoms. L is an amino group or a reactive derivative thereof, or a group containing an acid dianhydride structure or a reactive derivative thereof. y is an integer of 1 or more and 199 or less.) The compound according to claim 5, wherein the residue of the compound represented by the general formula (4) and y is 1 or more and 20 or less, and the residue of the compound represented by the general formula (4) and wherein y is 21 or more and 60 or less. Polyimide precursor, characterized in that. The polyimide precursor according to any one of claims 1 to 6, comprising a residue of a diamine represented by the following general formula (9).

(In the general formula (9), R ⁸ is a substituted or unsubstituted phenyl group. s represents an integer of 1 or more and 4 or less.) It is formed by imidating the polyimide precursor in any one of Claims 1-7, The polyimide characterized by the above-mentioned. A polyimide comprising a structure represented by the general formula (1) and a structural unit represented by the general formula (14).

(In general formula (1), R ¹ and R ² each independently represent a monovalent organic group having 1 to 20 carbon atoms. m represents an integer of 1 or more and 200 or less.)

(In the general formula (14), R ³ represents a divalent organic group represented by the general formula (3). R ⁴ represents an aromatic tetracarboxylic acid residue.)

10. The polyimide according to claim 9, wherein when the total amount of the polyimide is 100 mass%, the structure represented by the general formula (1) is contained in an amount of 0.1 mass% or more and 30 mass% or less. The polyimide according to claim 9 or 10, wherein the polyimide contains 30 mol% or more of the structural units of the divalent organic group represented by the general formula (3) among all the diamine residues contained in the polyimide. A polyimide resin film comprising the polyimide according to any one of claims 8 to 11. The polyimide resin film according to claim 12, wherein the polyimide resin film has a density of 1.20 g/cm 3 or more and 1.43 g/cm 3 or less. The polyimide resin film according to claim 12 or 13, wherein the in-plane/out-of-plane birefringence is 0.01 or less. The polyimide resin film according to any one of claims 12 to 14, wherein the degree of yellowness is 3 or less. A flexible device comprising the polyimide resin film according to any one of claims 12 to 15.

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